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UBC Theses and Dissertations

Photoelectron spectroscopic studies of unstable molecular species Lau, Woon Ming 1982

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PHOTOELECTRON SPECTROSCOPIC STUDIES OF UNSTABLE MOLECULAR SPECIES by WOON MING^LAU B . S c , The Chi n e s e U n i v e r s i t y of Hong Kong, 1976 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n THE FACULTY OF GRADUATE STUDIES ( Department of C h e m i s t r y ) We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA J a n u a r y , 1982 (c) Woon Ming Lau, 1982 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an advanced degree a t the U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e head o f my department o r by h i s o r h e r r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Department o f CH€MII The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook P l a c e V ancouver, Canada V6T 1W5 1-6 (2/79) i i A b s t r a c t A p h o t o e l e c t r o n (PE) s p e c t r o m e t e r has been m o d i f i e d t o st u d y u n s t a b l e m o l e c u l e s . R e c o n s t r u c t i o n of the i o n i z a t i o n chamber has made the i o n i z a t i o n r e g i o n more e a s i l y a c c e s s i b l e , and a q u a d r u p o l e mass s p e c t r o m e t e r has been added i n o r d e r t o p r o v i d e mass s p e c t r a l i d e n t i f i c a t i o n d a t a under the same c o n d i t i o n s as the PE e x p e r i m e n t . The system i s c o n t r o l l e d by a LSI 11/03 microcomputer w i t h s u i t a b l e i n t e r f a c i n g hardware. A r e a l - t i m e o p e r a t i n g system program has been d e v e l o p e d f o r da t a h a n d l i n g . L i g h t s o u r c e s such as the HLc (Hydrogen Lyman a l i n e , l0.2eV) and H L c f r (a m i x t u r e of Hydrogen Lyman o, p and r l i n e s ) r a d i a t i o n s were used t o reduce i o n - f r a g m e n t a t i o n . Pure S „ N q , S f t N 2 , S 3 N 3 and S 2 N 2 were s y n t h e s i z e d and s t u d i e d w i t h t h i s system. The i n t e r r e l a t i o n s h i p between the gas phase r e a c t i v i t i e s of t h e s e compounds has been e s t a b l i s h e d . The study of CH 3NO, i t s t r a n s and c i s d i m e r s , and i t s isomer, CH 2NOH, has c l a r i f i e d some m i s t a k e s i n s p e c i e s i d e n t i f i c a t i o n i n p r e v i o u s PE s p e c t r o s c o p i c work on CH 3NO and i t s d i m e r s . These two s t u d i e s i l l u s t r a t e our a b i l i t y t o i d e n t i f y u n s t a b l e s p e c i e s even i n a v e r y complex m i x t u r e w i t h t h i s system. A cryopump was c o n s t r u c t e d and may be p o s i t i o n e d c l o s e t o the i o n i z a t i o n r e g i o n o p p o s i t e t o the sample i n l e t , which may be a f i n e n o z z l e . T h i s f a s t pumping n o z z l e system has been used t o produce n e a r l y pure N 2 0 , , and a c h a r g e - t r a n s f e r complex ( C H 3 ) 2 0 - B F 3 , and e x c e l l e n t PE s p e c t r a of t h e s e s p e c i e s were o b t a i n e d . i i i A l i b r a r y of computer programs has been e s t a b l i s h e d which p r o v i d e s a wide v a r i e t y of quantum m e c h a n i c a l computations a p p l i c a b l e t o PE band a s s i g n m e n t s . These programs, such as CNDO/2, MINDO/3, MNDO, HAM/3, GAUSSIAN 70 and 76, and RSPT ( f o r p e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' theorem), were used throughout t h i s work and t h e i r a c c u r a c y and e f f i c i e n c y a s s e s s e d . Koopmans' theorem has been shown t o break down i f a p p l i e d t o the i o n i z a t i o n of CH3NO and N 2Oj,. Moreover, shake-up p r o c e s s e s i n the Hel r e g i o n have been s t u d i e d f o r t h e s e two m o l e c u l e s and S S N 2 . S e v e r a l of the m o l e c u l e s , such as S„N 2, S 3 N 3 and ( C H 3 ) 2 0 - B F 3 , have not been i n v e s t i g a t e d by PE s p e c t r o s c o p y b e f o r e . i v T a b l e of C o n t e n t s page A b s t r a c t i T a b l e of C o n t e n t s i v L i s t of T a b l e s x L i s t of F i g u r e s x i i i L i s t of A b b r e v i a t i o n s x v i i i Acknowledgements x i x PART I G e n e r a l Background 1 Chapter 1 I n t r o d u c t i o n 2 R e f e r e n c e s (Chapter 1) 7 Chapter 2 T h e o r e t i c a l I P ' s i n PES and P r i n c i p l e s of Quadru-p o l e Mass S p e c t r o m e t r y 9 2.1 I n t r o d u c t i o n 9 2.2 T h e o r e t i c a l I P ' s i n PES 10 A Koopmans' theorem 10 B Breakdown of Koopmans' theorem 12 C P e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' theorem 18 D The s e m i - e m p i r i c a l HAM/3 method 25 E V a l e n c e - e l e c t r o n shake-up p r o c e s s e s 28 2.3 P r i n c i p l e s of q u a d r u p o l e mass s p e c t r o m e t r y 31 R e f e r e n c e s (Chapter 2) 37 PART I I System Development 41 Chapter 3 Hardware Development 42 V 3.1 C o n s t r u c t i o n of the PE sp e c t r o m e t e r 42 A The vacuum system 43 B The e l e c t r o n energy a n a l y z e r 47 C The l i g h t s o u r c e u n i t 53 D The s c a n n i n g system 54 E The d e t e c t i n g system 54 3.2 A d d i t i o n of a qu a d r u p o l e mass s p e c t r o m e t e r t o the PE sp e c t r o m e t e r 57 A C o n s t r u c t i o n of the quadrupole mass s p e c t r o -meter 57 B C o u p l i n g of the qua d r u p o l e mass s p e c t r o m e t e r to the PE s p e c t r o m e t e r 65 C Performance of the qua d r u p o l e mass s p e c t r o -meter 69 3.3 Hardware f o r computer c o n t r o l of the PE/PIM s p e c t r o m e t e r 79 Re f e r e n c e s (Chapter 3) 83 Chapter 4 So f t w a r e Development 84 4.1 I n t r o d u c t i o n 84 4.2 The l i b r a r y of computer programs f o r PES 86 A The ab i n i t i o GAUSSIAN 70 and 76 programs 86 B S e m i - e m p i r i c a l CNDO/2, INDO, MINDO/3 and MNDO programs 90 C The s e m i - e m p i r i c a l HAM/3 program 93 D Comparison of the performance of the GAUS-SIAN 70, CNDO/2, MINDO/3, HAM/3 and MNDO programs 94 v i E Use of the RSPT program i n c o r r e c t i n g Koopmans' theorem 106 4.3 A s m a l l r e a l - t i m e o p e r a t i o n system program f o r microcomputer c o n t r o l of the s p e c t r o m e t e r s 113 A Aim of t h e system program 113 B The d e s i g n of the system program 113 C Imp l e m e n t a t i o n of the d e s i g n 122 D R e s u l t s and D i s c u s s i o n 123 R e f e r e n c e s (Chapter 4) 125 PART I I I System A p p l i c a t i o n s 129 I I I A . A Study of Some S u l f u r N i t r i d e s - S f lN f l f S 2 N 2 , S„N 2, and S 3 N 3 130 Chapter 5 T e t r a s u l f u r t e t r a n i t r i d e , S„N,, and d i s u l f u r d i n i t r i d e , S 2 N 2 132 5.1 I n t r o d u c t i o n 132 5.2 E x p e r i m e n t a l 135 5.3 R e s u l t s 137 A The S»N„ vapor 137 B S^ N,, vapor over s i l v e r wool 137 C S,N a vapor over Pyrex wool 141 5.4 D i s c u s s i o n 145 A P y r o l y s i s w i t h s i l v e r wool 145 B P y r o l y s i s w i t h Pyrex wool 148 5.5 C o n c l u s i o n 149 R e f e r e n c e s (Chapter 5) 151 v i i Chapter 6 T e t r a s u l f u r d i n i t r i d e S«N 2 153 6.1 I n t r o d u c t i o n 153 6.2 E x p e r i m e n t a l 154 6.3 R e s u l t s 156 6.4 D i s c u s s i o n 160 6.5 C o n c l u s i o n 167 R e f e r e n c e s (Chapter 6) 169 Chapter 7 T r i s u l f u r t r i n i t r i d e S 3 N 3 171 7.1 I n t r o d u c t i o n 171 7.2 E x p e r i m e n t a l 176 7.3 R e s u l t s 176 A The s p e c t r a of the vapor 176 B Thermal s t a b i l i t y of the vapor 179 C Condensed phase r e a c t i o n s of t h e vapor 179 7.4 D i s c u s s i o n 179 7.5 C o n c l u s i o n 189 R e f e r e n c e s (Chapter 7) 190 I I I B . A study of monomeric n i t r o s o m e t h a n e , i t s c i s and t r a n s d i m e r s , and formaldoxime 192 Chapter 8 A s t u d y of monomeric n i t r o s o m e t h a n e , i t s c i s and t r a n s d i m e r s , and formaldoxime 193 8.1 I n t r o d u c t i o n 193 8.2 E x p e r i m e n t a l 194 A S y n t h e s i s of the compounds and s a m p l i n g p r o c e d u r e s 194 B T h e o r e t i c a l c a l c u l a t i o n s 196 v i i i 8.3 R e s u l t s 196 8.4 D i s c u s s i o n 207 8.5 C o n c l u s i o n 211 R e f e r e n c e s (Chapter 8) 212 I I I C . A study of some weakly a s s o c i a t e d m o l e c u l e s by u s i n g a f a s t pumping n o z z l e i n l e t system 215 Chapter 9 N 20» 217 9.1 I n t r o d u c t i o n 217 9.2 E x p e r i m e n t a l 218 9.3 R e s u l t s 218 9.4 D i s c u s s i o n 224 9.5 C o n c l u s i o n 229 R e f e r e n c e s (Chapter 9) 232 Chapter 10 The study of a 1:1 charge t r a n s f e r complex, ( C H 3 ) 2 0 - B F 3 234 10.1 I n t r o d u c t i o n 234 10.2 E x p e r i m e n t a l 235 10.3 R e s u l t s 236 10.4 D i s c u s s i o n 242 A Complex f o r m a t i o n of ( C H 3 ) 2 0 - B F 3 242 B I d e n t i f i c a t i o n of the complex 244 C S t r u c t u r e of the complex 245 D Assignment of the PE bands and bonding i n the complex 247 10.5 C o n c l u s i o n 251 R e f e r e n c e s (Chapter 10) 253 i x PART IV Summary and P r o g n o s i s 255 Chapter 11 Summary and P r o g n o s i s 256 R e f e r e n c e s (Chapter 11) 263 APPENDIX 264 X L i s t of T a b l e s page Chapter 2 1 R e l a t i v i s t i c c o r r e c t i o n s f o r I P ' s of some atoms 15 Chapter 3 1 Some t y p i c a l v a l u e s of the v o l t a g e s f o r the l e n s system of the PE s p e c t r o m e t e r 49 2 E n e r g i e s of some l i g h t s o u r c e s f o r UPS and PIMS 68 3 The t r a n s m i t t a n c e c u t - o f f of some uv f i l t e r s 72 Chapter 4 1 The b a s i s s e t e f f e c t on the c a l c u l a t i o n s of H 20 89 2 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of t r a n s - d i a z e n e 95 3 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of tran s - m e t h y -d i a z e n e 96 4 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of trans-azomethane 97 5 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of c i s - h e x a f l u o r o -azomethane 98 6 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of t r a n s - d i f l u o r o -d i a z e n e 99 7 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of m e t h y l e n i m i n e 100 8 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of N-methylmethyl-enimine 101 9 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of C-methylmethyl-enimine 102 10 R e s u l t s of the l i n e a r l e a s t square f i t s of the c a l c u l a t e d x i I P ' s t o the e x p e r i m e n t a l I P ' s 104 11 R e s u l t s ' o f the RSPT c a l c u l a t i o n s f o r HBF 2 109 12 R e s u l t s of the RSPT c a l c u l a t i o n s f o r CH3NO 110 13 R e s u l t s of the RSPT c a l c u l a t i o n s f o r some l i n e a r boron m o l e c u l e s 1 1 1 Chapter 6 1 E x p e r i m e n t a l and t h e o r e t i c a l I P ' s of S„N 2 159 2 R e s u l t s of the geometry o p t i m i z a t i o n f o r S„N 2, a comparison of the C i v / and C 6 s t r u c t u r e s 161 3 The m o l e c u l a r geometry of S„N 2 by ab i n i t i o c a l c u l a t i o n s and x - ray c r y s t a l l o g r a p h y 164 Chapter 8 1 E x p e r i m e n t a l and t h e o r e t i c a l I P ' s of monomeric n i t r o s o -methane 197 2 E x p e r i m e n t a l and t h e o r e t i c a l I P ' s of monomeric f o r m a l -doxime 198 3 E x p e r i m e n t a l and t h e o r e t i c a l I P ' s of the t r a n s n i t r o s o -methane dimer 199 4 T h e o r e t i c a l I P ' s of the c i s n i t r o s o m e t h a n e dimer 200 5 A comparison of observ e d and t h e o r e t i c a l I P ' s c a l c u l a t e d by RSPT f o r monomeric n i t r o s o m e t h a n e 201 6 I n t e r p r e t a t i o n of the i o n i z a t i o n and shake-up p r o c e s s e s of CH 3NO i n the Hel r e g i o n by the m o d i f i e d HAM/3 method 210 x i i Chapter 9 1 The e x p e r i m e n t a l and t h e o r e t i c a l I P ' s of N 20„ 223 2 E x p e r i m e n t a l r e s u l t s of the f o r m a t i o n of N 20„ by PES s t u d i e s 226 3 I n t e r p r e t a t i o n of the i o n i z a t i o n and shake-up p r o c e s s e s of N 20„ i n the Hel r e g i o n by the m o d i f i e d HAM/3 method 230 Chapter 10 1 The r e s u l t s of geometry o p t i m i z a t i o n s on the 1:1 complex ( C H 3 ) 2 0 - B F 3 and a comparison of the t o t a l e n e r g i e s o b t a i n e d by SCF c a l c u l a t i o n s on the complex, ( C H 3 ) 2 0 and BF 3 241 2 E x p e r i m e n t a l and t h e o r e t i c a l I P ' s of ( C H 3 ) 2 0 - B F 3 243 x i i i T a b l e of F i g u r e s page Chapter 2 1 The e x p e r i m e n t a l Hel PE spectrum and t h e o r e t i c a l PE s p e c t r a of N 2 14 2 Schematic diagram of a qu a d r u p o l e mass s p e c t r o m e t e r 32 3 S o l u t i o n of the M a t h i e u e q u a t i o n s - s t a b i l i t y diagrams f o r the x and y d i r e c t i o n s 34 4 The s t a b l e r e g i o n f o r both x and y d i r e c t i o n s near the o r i g i n 35 Chapter 3 1 The i o n i z a t i o n chamber and the e l e c t r o n a n a l y z e r of the PE s p e c t r o m e t e r 44 2 The i o n i z a t i o n chamber and the l i g h t source u n i t of the PE s p e c t r o m e t e r 45 3 The c o n s t r u c t i o n of the cryopump 46 4 The l e n s system of the PE s p e c t r o m e t e r 48 5 The h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r 51 6 A b l o c k diagram of the s c a n n i n g v o l t a g e c o n t r o l f o r the PE/PIM s p e c t r o m e t e r 55 7 The r o d assembly of the qu a d r u p o l e mass s p e c t r o m e t e r ( c r o s s s e c t i o n p e r p e n d i c u l a r t o the a x i a l a x i s ) 58 8 The r o d assembly and the d e t e c t o r of the qu a d r u p o l e mass s p e c t r o m e t e r ( c r o s s s e c t i o n a l o n g the a x i a l a x i s ) 59 9 The e l e c t r o n impact i o n i z a t i o n k i t f o r the qu a d r u p o l e mass s p e c t r o m e t e r 61 x i v 10 The p h o t o i o n i z a t i o n chamber f o r the quadrupole mass s p e c t r o m e t e r 62 11 A b l o c k diagram of the e l e c t r o n i c c o n t r o l f o r the quad-r u p o l e mass s p e c t r o m e t e r 64 12 The c o n s t r u c t i o n of the PE/PIM s p e c t r o m e t e r 66 13 The t r a n s m i t t a n c e c u r v e of L i F (1.55mm) a t 26°C 70 14 The c o n s t r u c t i o n of the f i l t e r h o l d e r 71 15 The Hel mass spectrum of CC1„ 74 16 The mass spectrum of CH 3I i o n i z e d by the r a d i a t i o n from the d i s c h a r g e of a. He, b. He w i t h a t r a c e of H 2, and c. 70% He w i t h 30% H 2 75 17 The HLapr and HLa mass s p e c t r a of a m i x t u r e of CH 3OH, CH 3CN and t o l u e n e 77 18 P r e s s u r e e f f e c t s on the degree of f r a g m e n t a t i o n and the r e l a t i v e count r a t e of the HLo£r mass spectrum of bromo-benzene 78 19 The s t r u c t u r e of the microcomputer c o n t r o l system 80 20 The s c a n n i n g p r o c e s s of a d i g i t i z e d spectrum 81 Chapter 4 1 R e s u l t s of t h e l i n e a r l e a s t square f i t s of the c a l c u l a t e d IP ' s t o the e x p e r i m e n t a l I P ' s 105 2 The r e l a t i v e c o s t s of the c a l c u l a t i o n s f o r each method e x p r e s s e d i n terms of the c o m p u t a t i o n a l time / e l e c t r o n s a g a i n s t the t o t a l number of e l e c t r o n s i n the m o l e c u l e 107 3 The s t r u c t u r e of the o p e r a t i n g system program 114 Chapter 5 1 The m o l e c u l a r s t r u c t u r e of SnN„ 2 The e x p e r i m e n t a l s e t u p f o r the p y r o l y s i s of S ( | N „ i n t o the PE/PIM s p e c t r o m t e r 3 The Hel PE spectrum of S«N« 4 The PIM s p e c t r a o f a S q N , , r e c o r d e d w i t h (a) the Hel and (b) the HLcpr l i g h t s o u r c e s 5 The time dependence of the c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s of S f t N „ over s i l v e r wool 6 The p y r o l y s i s p r o d u c t s of S f l N „ over s i l v e r wool a t 260°C b e f o r e the steady s t a t e (a) the Hel PE spectrum of the p r o d u c t m i x t u r e and (b) the HLcpr PIM spectrum of the pr o d u c t m i x t u r e 7 The Hel PE spectrum of S 2 N 2 8 The PIM s p e c t r a of S 2 N 2 r e c o r d e d w i t h (a) the Hel and (b) the HLa^r l i g h t s o u r c e s 9 The p y r o l y s i s p r o d u c t s of S«N„ over Pyrex wool a t 280°C (a) the Hel PE spectrum of the p r o d u c t m i x t u r e (b) the HLo0r PIM spectrum of the p r o d u c t m i x t u r e 10 The temperature dependence of the c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s of S « N | , over Pyrex wool Chapter 6 1 The PIM s p e c t r a of S f t N 2 r e c o r d e d w i t h (a) H e l , (b) HLa*r and (c) HLa r a d i a t i o n 2 The Hel PE spectrum of S„N 2 3 The ab i n i t i o o p t i m i z e d Cav and C 5 s t r u c t u r e s of S a N 2 4 The e l e c t r o n i c s t r u c t u r e of S«N 2 Chapter 7 1 The c r y s t a l s t r u c t u r e of the (SN) y polymer 2 S t r u c t u r e of the S 3N 3~ a n i o n 3 The Hel P E spectrum of S 3 N 3 4 The P I M s p e c t r a of S 3 N 3 r e c o r d e d w i t h (a) H e l , (b) HLcp and (c) HLo r a d i a t i o n 5 The HLa^r P I M s p e c t r a r e c o r d e d d u r i n g the v a p o r i -z a t i o n of the f r e s h l y condensed S 3 N 3 Chapter 8 1 The Hel P E spectrum (a) o f . n i t r o s o m e t h a n e t o g e t h e r w i t h the P I M s p e c t r a r e c o r d e d w i t h (b) Hel and (c ) H L a ^ r r a d i a t i o n 2 The Hel P E spectrum (a) of t r a n s n i t r o s o m e t h a n e dimer t o g e t h e r w i t h the P I M s p e c t r a r e c o r d e d w i t h (b) Hel and (c)HLopr r a d i a t i o n 3 The Hel P E spectrum (a) of formaldoxime t o g e t h e r w i t h the P I M s p e c t r a r e c o r d e d w i t h (b) Hel and (c)HLapr r a d i a t i o n 4 A p l o t of t h e o r e t i c a l I P ' s of CH 3NO ( A ( E )) a g a i n s t -T the t r u n c a t i o n l i m i t , 10 Chapter 9 1 P E s p e c t r a of (a) N0 2 and (b) N 2 0 4 / N 0 2 m i x t u r e xv i i 2 The mass s p e c t r a of the N 2O a/N0 2 m i x t u r e i o n i z e d by (a) Hel and (b) HLc^r r a d i a t i o n 221 3 The Hel PE spectrum of N 20« 222 4 E x p e r i m e n t a l and t h e o r e t i c a l PE s p e c t r a of N 20, 225 Chapter 10 1 The Hel PE spectrum of a 1:1 m i x t u r e of ( C H 3 ) 2 0 and BF 3 o b t a i n e d from a complete d i s s o c i a t i o n of the ( C H 3 ) 2 0 - B F 3 complex. 237 2 The Hel PE spectrum of the 1:1 ( C H 3 ) 2 0 - B F 3 complex p l u s the f r e e c o n s t i t u e n t s 238 3 The mass s p e c t r a of the 1:1 ( C H 3 ) 2 0 - B F 3 complex p l u s the f r e e c o n s t i t u e n t s o b t a i n e d (a) w i t h a Hel l i g h t s o u r c e , and (b) HLo l i g h t s o u r c e 239 4 The s t r i p p e d Hel PE spectrum of the 1:1 ( C H 3 ) 2 0 - B F 3 complex 240 5 The s t r u c t u r e of the 1:1 ( C H 3 ) 2 0 - B F 3 complex 246 6 0.92x£'s of the 4 - 3 1 G c a l c u l a t i o n s on ( C H 3 ) 2 0 , ( C H 3 ) 2 0 - B F 3 and B F 3 , and e x p e r i m e n t a l v a l u e s f o r ( C H 3 ) 2 0 and BF 3 248 Chapter 11 1 The c o n s t r u c t i o n of a double f u r n a c e h e a t i n g u n i t w i t h a n o z z l e sample i n l e t 258 L i s t of A b b r e v i a t i o n s ADC a n a l o g t o d i g i t a l c o n v e r t e r amu atomic mass u n i t A O a t o m i c o r b i t a l CEM c h a n n e l e l e c t r o n m u l t i p l i e r CI c o n f i g u r a t i o n i n t e r a c t i o n cps c o u n t s per seconds CPU c e n t r a l p r o c e s s o r u n i t DAC d i g i t a l t o a n a l o g c o n v e r t e r HF H a r t r e e - F o c k HLc hydrogen Lyman c l i n e ( l0.20eV) HLopr hydrogen Lyman o c o n t a m i n a t e d w i t h p ( l 2 . 0 9 e V , 10%) and r 02.75eV, 1%) IP i o n i z a t i o n p o t e n t i a l i r i n f r a r e d MO m o l e c u l a r o r b i t a l mp m e l t i n g p o i n t op-amp o p e r a t i o n a l a m p l i f i e r PE p h o t o e l e c t r o n PES p h o t o e l e c t r o n s p e c t r o s c o p y PIM p h o t o i o n i z a t i o n mass PIMS p h o t o i o n i z a t i o n mass s p e c t r o m e t r y RSPT R a y l e i g h - S c h r o d i n g e r p e r t u r b a t i o n t h e o r y SCF s e l f - c o n s i s t e n t f i e l d UPS u l t r a v i o l e t p h o t o e l e c t r o n s p e c t r o s c o p y uv u l t r a v i o l e t x i x Acknowledgements I would l i k e t o thank Dr. C.A. McDowell and Dr. D.C. F r o s t f o r t h e i r s u p p o r t t h r o u g o u t t h i s work. I owe a s p e c i a l g r a t i t u d e t o Dr. N.P.C. Westwood f o r h i s guidance and h e l p i n the PES l a b o r a t o r y , and many s u g g e s t i o n s about t h i s t h e s i s . I w i s h t o thank Dr. D.P. Chong, Dr. T. M i n a t o , Dr. N.L. Paddock, Dr. J.S. Tse, Dr. C. K i r b y , Dr. M.H. Palmer, Dr. S. Chanson, Dr. F. C a r n o v a l e and Dr. R.T. Oakley f o r u s e f u l d i s c u s s i o n s and thank Dr. D.P. Chong f o r the use of h i s programs, Dr. N.L. Paddock f o r the s u p p l y of many s u l f u r -n i t r o g e n compounds, and Dr. R.T. Oakley f o r the s u p p l y of the (SN) c r y s t a l s . I would l i k e t o acknowledge the a s s i s t a n c e of the m e c h a n i c a l and e l e c t r i c a l s t a f f of the C h e m i s t r y Department a t U.B.C., e s p e c i a l l y Mr. E. M a t t e r , Mr. C. M c C a f f e r t y , Mr. B. Po-w e l l and Mr. M. H a t t o n . F i n a l l y , I a l s o thank M i s s S.S. Yau f o r p r o o f - r e a d i n g t h i s t h e s i s . 1 PART I G e n e r a l Background Chapter 1 I n t r o d u c t i o n E i n s t e i n ' s i n t e r p r e t a t i o n of the p h o t o e l e c t r i c e f f e c t (1) demonstrated t h a t when'a sample i s i r r a d i a t e d by photons of s u f -f i c i e n t e nergy, e l e c t r o n s a r e e j e c t e d , i . e . : M + hv • > M + + e and the f o l l o w i n g e q u a t i o n h o l d s f o r t h i s p r o c e s s hv = K E e + - ) 1 -1 where KE e i s the k i n e t i c energy of the e j e c t e d e l e c t r o n , E M + and E^ are the t o t a l energy of the i o n and n e u t r a l m o l e c u l e r e s p e c t i v e l y . P h o t o e l e c t r o n s p e c t r o s c o p y (PES) i s a s p e c i f i c study of t h i s phenomenon, wherein KE i s measured, and by eqn. 1.1, ( E ^ + - E^) i s deduced, s i n c e hv i s known. In t h i s t h e s i s , (E... - E„) i s r e f e r r e d t o as i o n i z a t i o n p o t e n t i a l (IP), no m atter whether the c o r r e s p o n d i n g p r o c e s s i s s i m p l y a d i r e c t i o n i z a t i o n of an e l e c t r o n or a more complex i o n i z a t i o n which i n v o l v e s s i m u l t a n e o u s e x c i t a t i o n of o t h e r e l e c t r o n ( s ) and mixes w i t h o t h e r i o n i z a t i o n p r o c e s s ( e s ) (see c h a p t e r 2, s e c t i o n 2.2E). By measuring IP's and t h e i r PE band shapes, m o l e c u l a r p r o p e r t i e s such as g e o m e t r i c s t r u c t u r e , b o n d i n g , s t a b i l i t y and d i p o l e moment, and p r o p e r t i e s of the i o n s may be deduced by c o r r e l a t i o n w i t h some o t h e r e x p e r i m e n t a l d a t a , i n c l u d i n g PE s p e c t r a of r e l a t e d compounds, and the r e s u l t s of quantum m e c h a n i c a l c a l c u l a t i o n s . S i n c e the f i r s t use of the i n t e n s e and r e l a t i v e l y 3 monochromatic Helo l i n e (21.22eV) as the r a d i a t i o n source i n the e a r l y 1960's by Turner et a l . , and a l i t t l e l a t e r by Vroom ( 2 ) , PE s t u d i e s have been expanding r a p i d l y . Nowadays, commercial PE s p e c t r o m e t e r s a r e a v a i l a b l e and s p e c t r o m e t e r s f o r s p e c i a l purposes have been c o n s t r u c t e d i n many l a b o r a t o r i e s a l l over the w o r l d . Other r a d i a t i o n s such as H e l l , x - r a y and s y n c h r o t r o n e m i s s i o n have been used s u c c e s s f u l l y i n PES. S e v e r a l books (3) have been p u b l i s h e d and the ' J o u r n a l of E l e c t r o n S p e c t r o s c o p y and R e l a t e d Phenomena' been e s t a b l i s h e d , c o v e r i n g both PES and i t s r e l a t e d f i e l d . U l t r a v i o l e t PES (UPS, or merely PES) i s now a w e l l e s t a b l i s h e d t e c h n i q u e used f o r the d e t e r m i n a t i o n of m o l e c u l a r e l e c t r o n i c s t r u c t u r e s . I P ' s of the v a l e n c e e l e c t r o n s have been shown t o s t r o n g l y c o r r e l a t e t o c h e m i c a l bonding i n m o l e c u l e s . In the e a r l y days, t h e s e s t u d i e s were c o n f i n e d t o s t a b l e gaseous or e a s i l y v o l a t i l i z e d m o l e c u l e s , but w i t h the improvement i n e x p e r i m e n t a l t e c h n i q u e s , the scope has been extended s u c c e s s f u l l y t o the study of u n s t a b l e s p e c i e s ( 4 ) . The u n s t a b l e s p e c i e s a r e o f t e n p o s s i b l e r e a c t i o n i n t e r m e d i a t e s , and a r e of tremendous t h e o r e t i c a l and c h e m i c a l i n t e r e s t . Those of r e l a t i v e l y s m a l l s i z e and g i v i n g w e l l r e s o l v e d PE s p e c t r a make t h e o r e t i c a l c a l c u l a t i o n s v i a b l e . In t h e s e c a s e s , the i o n i z a t i o n p r o c e s s e s can be b e t t e r u n d e r s t o o d , and a l s o the v a l i d i t y of the c o r r e s p o n d i n g t h e o r e t i c a l t r e a t m e n t s can be r e a l i s t i c a l l y a s s e s s e d . In a n o t h e r f r u i t f u l a p proach, PES s t u d i e s of u n s t a b l e s p e c i e s have been d i r e c t e d t o the dynamics of gas phase 4 r e a c t i o n s . U n s t a b l e s p e c i e s , due t o t h e i r s h o r t l i f e - t i m e , a r e u s u a l l y g e n e r a t e d as c l o s e as p o s s i b l e t o the i o n i z a t i o n r e g i o n i n a PE s p e c t r o m e t e r . Methods such as atom-molecule r e a c t i o n s , microwave d i s c h a r g e s , p y r o l y s i s , and, more r e c e n t l y , n o z z l e t e c h n i q u e s have been used w i t h s u c c e s s . However, the y i e l d s of these r e a c t i o n s a r e u s u a l l y v e r y s m a l l . Hence, the t a r g e t m o l e c u l e s a r e u s u a l l y a m i x t u r e of the u n s t a b l e s p e c i e s and the r e a c t a n t s p l u s s i d e - p r o d u c t s , which a l l i o n i z e and c o n t r i b u t e t o the PE s p e c t r a . T h i s i s the most se v e r e problem i n PE s t u d i e s of u n s t a b l e s p e c i e s ; however, as has been demonstrated i n t h i s t h e s i s , the PE s p e c t r a can be used t o m o n i t o r gas phase r e a c t i o n s as they t a k e p l a c e under d i f f e r e n t c o n d i t i o n s . T h i s t h e s i s i s p a r t i c u l a r l y r e l a t e d t o the e s t a b l i s h m e n t of a system f o r t h e s e approaches t o the st u d y of u n s t a b l e s p e c i e s . A l i b r a r y has been s e t up, which c o n t a i n s v a r i o u s ab i n i t i o and s e m i - e m p i r i c a l programs f o r MO c a l c u l a t i o n s , the RSPT program ( d e a l i n g w i t h c o r r e c t i o n s of Koopmans' theorem), and the m o d i f i e d HAM/3 program ( p e r f o r m i n g v a l e n c e - e l e c t r o n shake-up c a l c u l a t i o n s ) . T h i s l i b r a r y has been w e l l documented and p r o v i d e s a wide spectrum of t h e o r e t i c a l means f o r c o r r e l a t i n g PE s p e c t r a t o the e l e c t r o n i c s t r u c t u r e s of m o l e c u l e s , which i s of most i n t e r e s t t o s c i e n t i s t s i n g e n e r a l . A q u a d r u p o l e mass sp e c t r o m e t e r has been c o u p l e d w i t h a m o d i f i e d PE s p e c t r o m e t e r t o more e a s i l y i d e n t i f y the ( u s u a l l y u n s t a b l e ) s p e c i e s i n the i o n i z a t i o n r e g i o n . High pumping speed i s i n c o r p o r a t e d i n o r d e r t o f a c i l i t a t e the study of the s h o r t - l i v e d and h i g h l y r e a c t i v e s p e c i e s . The system i s c o n t r o l l e d u s i n g a LSI 11/03 5 microcomputer and a r e a l - t i m e o p e r a t i n g system program f o r d a t a a c q u i s i t i o n , d a t a s t o r a g e and d a t a m a n i p u l a t i o n (such as spectrum s t r i p p i n g ) . Mass s p e c t r o m e t r i c measurements t a k e n under same c o n d i t i o n s as the PE ones have been shown t o be most h e l p f u l i n s p e c i e s i d e n t i f i c a t i o n . The i n t e g r a t i o n of mass s p e c t r a l d a t a r e c o r d e d w i t h d i f f e r e n t l i g h t s o u r c e s ( d i f f e r e n t degrees of f r a g m e n t a t i o n ) and the PE d a t a o b t a i n e d under v a r i o u s c o n d i t i o n s has produced much i n t e r e s t i n g i n f o r m a t i o n about some gas phase r e a c t i o n s . P a r t I of t h i s t h e s i s c o n s i s t s of Chapter 1 ( I n t r o d u c t i o n ) and Chapter 2. The l a t t e r c h a p t e r s u r v e y s the t h e o r e t i c a l background of IP c a l c u l a t i o n s , from the a p p l i c a t i o n of Koopmans' theorem w i t h s e m i - e m p i r i c a l and ab i n i t i o c a l c u l a t i o n s , the HAM/3 s e m i - e m p i r i c a l method which a v o i d s t h e use of Koopmans' theorem, the p e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' theorem, t o v a l e n c e - e l e c t r o n shake-up c a l c u l a t i o n s . The p r i n c i p l e s of q u a d r u p o l e mass s p e c t r o m e t r y a r e a l s o o u t l i n e d . In P a r t I I , Chapter 3 and 4 d e a l w i t h the hardware and s o f t w a r e . development of the c o m p u t e r i z e d system r e s p e c t i v e l y . The o p e r a t i n g system program d e s c r i b e d i n Chapter 4 appears i n the a p p e n d i x . P a r t I I I of the t h e s i s i s c o n cerned w i t h a p p l i c a t i o n s of the system. Chapter 5 d e s c r i b e s the study of the PE s p e c t r a of SaN,, and S 2 N 2 , and the gas phase p y r o l y s i s of Si,Ntt under d i f f e r e n t c o n d i t i o n s . These gas phase r e a c t i o n s a r e l a t e r r e l a t e d t o the s t u d i e s of S«N 2 (Chapter 6) and S 3 N 3 (Chapter 7 ) . S i n c e a l l t h r e e c h a p t e r s c o n c e r n s u l f u r - n i t r o g e n m o l e c u l e s , they 6 are grouped i n P a r t I I I A . Chapter 8 f u r t h e r d emonstrates the c a p a b i l i t y of the system i n s t u d y i n g u n s t a b l e s p e c i e s . The p r o j e c t d e s c r i b e d i n t h i s c h a p t e r c l a r i f i e s m i s t a k e n s p e c i e s assignments i n p r e v i o u s s t u d i e s of CH3NO and i t s d i m e r s . The breakdown of Koopmans' theorem and the o c c u r r e n c e of shake-up peaks i n the i n t e r p r e t a t i o n of the Hel PE spectrum of CH3NO are a l s o d i s c u s s e d . P a r t I I I C d e s c r i b e s two a d i a b a t i c e x p a n sion s t u d i e s : the p r o d u c t i o n of N 2 0 4 (Chapter 9) and a charge t r a n s f e r complex ( C H 3 ) 2 0 - B F 3 (Chapter 10). Shake-up peaks i n the Hel PE spectrum of N 2O f l a r e i n t e r p r e t e d . F i n a l l y , Chapter 11 summarizes the o v e r a l l impact of the work d e s c r i b e d i n t h i s t h e s i s , and i n d i c a t e s some p o t e n t i a l l y f r u i t f u l a p p l i c a t i o n s of the t e c h n i q u e s which have been d e v e l o p e d . 7 R e f e r e n c e s (Chapter 1) 1. A. E i n s t e i n , Ann. d. P h y s i k , 17(1905)132, and 20(1906)199. 2. (a) D.W. T u r n e r , M.I. A l - J o b o u r y , J . Chem. Phys., 37(1962) 3007. (b) D.A. Vroom, Ph. D. t h e s i s , UBC, 1965. 5141 . 3. Some examples a r e : (a) D.W. T u r n e r , C. Baker, A.D. Baker and C.R. B r u n d l e , ' M o l e c u l a r p h o t o e l e c t r o n s p e c t r o s c o p y ' , W i l e y , London, 1970. (b) D.A. S h i r l e y , ed., ' E l e c t r o n s p e c t r o s c o p y ' , N o r t h H o l -l a n d , Amsterdam, 1972. (c) A.D. Bake r , D. B e t t e r i d g e , ' P h o t o e l e c t r o n s p e c t r o s c o p y c h e m i c a l and a n a l y t i c a l a s p e c t s ' , Pergamon, O x f o r d , 1972. (d) J.H.D. E l a n d , ' P h o t o e l e c t r o n s p e c t r o s c o p y ' , H a l s t e d P r e s s , New York, 1974. (e) T.A. C a r l s o n , ' P h o t o e l e c t r o n and Auger s p e c t r o s c o p y ' , Plenum P r e s s , New York, 1975. ( f ) J.D. D u n i t z , P. Hemmerich, R.H. Holm, J.A. I b e r s , C.K. J o r g e n s e n , J.B. N e i l a n d s , D. Reinen and R.J.P. W i l -l i a m s , ed., ' P h o t o e l e c t r o n S p e c t r o m e t r y ' , S t r u c t u r e and Bonding, 24(1975). (g) J.W. R a b a l a i s , ' P r i n c i p l e s of u l t r a v i o l e t p h o t o e l e c t -ron s p e c t r o s c o p y ' , W i l e y , New York, 1977. (h) C.R. B r u n d l e and A.D. Baker, ed., ' E l e c t r o n s p e c t r o -scopy - t h e o r y , t e c h n i q u e and a p p l i c a t i o n s ' , 1(1977), 2(1978) and 3(1979), Academic P r e s s , New York, ( i ) D. B r i g g s , ed., 'Handbook of x-ray and u l t r a v i o l e t p h o t o e l e c t r o n s p e c t r o s c o p y ' , Heyden, London, 1977. ( j ) J . B e r k o w i t z , ' P h o t o a b s o r p t i o n , p h o t o i o n i z a t i o n and p h o t o e l e c t r o n s p e c t r o s c o p y ' , Academic P r e s s , New York, 1979. (k) G. Wendin, 'Breakdown of the o n e - e l e c t r o n p i c t u r e s i n p h o t o e l e c t r o n s p e c t r a ' , S t r u c t u r e and Bonding, 45 (1981 ) See, f o r i n s t a n c e , (a) A.B. C o r n f o r d , Ph.D. t h e s i s , UBC, 1971. (b) S.T. Lee, Ph.D. t h e s i s , UBC, 1974. (c) D. V o c e l l e , A. D a r g e l o s , R. P o t t i e r and C. S a n d o r f y , J . Chem. Phys., 66(1977)2869. (d) C R . MacDonald, M.Sc. t h e s i s , UBC, 1978. (e) D. C o l o u r b n e , Ph.D. t h e s i s , UBC, 1979. ( f ) J . B e r k o w i t z , C H . Batson and G.L. Goodman, J . Chem. Phys., 71(1979)2624. (g) F. C a r n o v a l e , Ph.D. t h e s i s , La Trobe U n i v e r s i t y , 1980. (h) G. J o n k e r s , R. Mooyman and C A . De Lange, Chem. Phys., 57(1981)97. ( i ) E.P.F. Lee and A.W. P o t t s , J . Phys. B, 14(1981)L61. ( j ) J.M. Dyke, N. J o n a t h a n , A. M o r r i s and M.J. W i n t e r , J . Chem. S o c , Faraday T r a n s . 2, 77(1981 )667. (k) D.P. Chong, C. K i r b y , W.M. Lau, T. M i n a t o and N.P.C. Westwood, Chem. Phys., 59(1981)75. 9 Chapter 2 T h e o r e t i c a l I P ' s i n PES and P r i n c i p l e s of  Quadrupole Mass S p e c t r o m e t r y 2.1 I n t r o d u c t i o n S e v e r a l books have been p u b l i s h e d c o n c e r n i n g PES (Chapter 1 ) , where the g e n e r a l p r i n c i p l e , t h e i n t e r p r e t a t i o n of the n a t u r e of PE bands and the band shapes, and the e s t i m a t i o n of p h o t o i o n i z a t i o n c r o s s - s e c t i o n s , e t c . , have been e x t e n s i v e l y r e v i e w e d , and so w i l l not be r e p e a t e d h e r e . However, s i n c e we are p a r t i c u l a r l y i n t e r e s t e d i n the study of t r a n s i e n t s p e c i e s which, i n many • c a s e s , a r e s m a l l m o l e c u l e s , and w i t h e v e r - i n c r e a s i n g computing power due t o the advances i n computer t e c h n o l o g y and development i n t h e o r e t i c a l methods, we have s t a r t e d u s i n g t h e o r e t i c a l c a l c u l a t i o n s of v e r y h i g h q u a l i t y t o i n t e r p r e t PE s p e c t r a . S i n c e the breakdown of Koopmans 1 theorem and t h e o c c u r r e n c e of v a l e n c e - e l e c t r o n shake-up p r o c e s s e s have been s t u d i e d t h e o r e t i c a l l y i n t h i s t h e s i s , the t h e o r y of p r e d i c t i n g I P ' s and i n t e r p r e t i n g the c o r r e s p o n d i n g i o n i z a t i o n p r o c e s s e s i s b r i e f l y summarized i n s e c t i o n 2.2. The c o u p l i n g of a q u a d r u p o l e mass s p e c t r o m e t e r t o a PE s p e c t r o m e t e r has been demonstrated i n t h e t h i r d p a r t (system a p p l i c a t i o n s ) of t h i s t h e s i s t o be i n v a l u a b l e i n i d e n t i f y i n g s p e c i e s i n a r a t h e r c o m p l i c a t e d m i x t u r e . S i n c e the p r i n c i p l e of q u a d r u p o l e mass s p e c t r o m e t r y i s seldom t r e a t e d i n a r t i c l e s or t e x t s c o n c e r n i n g PES, i t i s c o n c i s e l y d e s c r i b e d i n the l a s t s e c t i o n of t h i s c h a p t e r . 10 2.2 T h e o r e t i c a l I P's i n PES 2.2A Koopmans' theorem PES measures t h e k i n e t i c e n e r g i e s of e j e c t e d e l e c t r o n s from m o l e c u l e s (or atoms) and hence t h e i r I P ' s . The w i d e l y used Koopmans' t h e o r e m ( 1 ) , which a s s e r t s t h a t I P ' s a r e e q u a l t o the n e g a t i v e of the o r b i t a l e n e r g i e s of the c o r r e s p o n d i n g m o l e c u l a r o r b i t a l s (MO's), i s a d i r e c t and s i m p l e l i n k a g e between th e s e e x p e r i m e n t a l q u a n t i t i e s and quantum m e c h a n i c a l p i c t u r e s of m o l e c u l e s , which i n t u r n p e r m i t m o l e c u l a r p r o p e r t i e s such as the n a t u r e of c h e m i c a l bonds, t o t a l energy, heat of f o r m a t i o n , and d i p o l e moment t o be deduced. The pr o o f of the theorem i s as f o l l o w s . C o n s i d e r a m o l e c u l e h a v i n g k s t a t i o n a r y n u c l e i , p o e l e c t r o n s and q i e l e c t r o n s . The t o t a l n o n r e l a t i v i s t i c e l e c t r o n i c energy E(p,q) i s g i v e n by ( i n atomic u n i t s ) H* = E(p,q)q 2.1 where H = V^-T - f t ) / f 2.2 and ^ i s the w a v e f u n c t i o n d e s c r i b i n g the e l e c t r o n s of the m o l e c u l e . The f i r s t two terms of eqn. 2.2 c o r r e s p o n d t o a s i t u a t i o n t h a t no f i e l d i s e x e r t e d between e l e c t r o n s , and the o n l y i n t e r a c t i o n i s the n u c l e i - e l e c t r o n a t t r a c t i o n . These two o n e - e l e c t r o n o p e r a t o r s a r e u s u a l l y grouped t o g e t h e r and c a l l e d the c o r e H a m i l t o n i a n p+<? ^ e = ! C - i < - T A ) . 2.3 The l a s t term of eqn. 2.2 i s o b v i o u s l y a t w o - e l e c t r o n 11 H a m i l t o n i a n d e s c r i b i n g the e l e c t r o n - e l e c t r o n r e p u l s i o n . The most common approach ot s o l v e eqn. 2.2 i s the H a r t r e e - F o c k S e l f - C o n s i s t e n t F i e l d (HF-SCF) method, the d e t a i l e d d e r i v a t i o n of which i s a v a i l a b l e i n most quantum c h e m i s t r y t e x t s (e.g. Ref. 2 ) . The t o t a l r e s t r i c t e d HF-SCF e l e c t r o n i c energy of a m o l e c u l e under such a p p r o x i m a t i o n i s where ^ L i r i s the energy which e l e c t r o n i would have i n the n u c l e a r frame-work i n the absence of o t h e r e l e c t r o n s and ^ i s a s p i n o r b i t a l . i s the Coulomb r e p u l s i o n i n t e g r a l between each p a i r of e l e c t r o n s . <ry- <4:(» <$<>>, ± i s the,exchange i n t e r a c t i o n between every p a i r of e l e c t r o n s of the same s p i n . The o n e - e l e c t r o n e i g e n v a l u e of an o o r b i t a l 0. i s cx , pi-t P « 6. = Hcc + X Jcj - Z/cT.y 2.7 J 0 I f one o e l e c t r o n i s removed from t h i s m o l e c u l e and we assume a l l t h e J t j and Kij v a l u e s remain u n a l t e r e d a f t e r i o n i z a t i o n ( f r o z e n o r b i t a l a p p r o x i m a t i o n , i . e . , a l l Cfx's do not change), a c c o r d i n g t o eqn. 2.4-, the t o t a l e l e c t r o n i c energy w i l l reduce t o E(p-1,q) = ZHu +±CL Z Jcj -ZZ&i-tltfj) 2'8 1 2 The IP of t h i s e l e c t r o n i s thus ~ " C H P P t g j : • - £ ^ ) - - 6 P J J 2.9 (note t h a t Ja = K l L ). Based on Koopmans' theorem, p o s i t i o n s of PE bands may be p r e d i c t e d by HF-SCF c a l c u l a t i o n s . There are s e v e r a l d i f f e r e n t approaches t o t h i s c o m p u t a t i o n . Ab i n i t i o methods e v a l u a t e a l l the t w o - e l e c t r o n i n t e g r a l s i n v o l v e d , and the q u a l i t y of t h e s e r e s u l t s depends on the s i z e of the b a s i s s e t used t o r e p r e s e n t the c o r r e s p o n d i n g atomic o r b t i a l s (AO's) of the c o n s t i t u e n t atoms. A l t e r n a t i v e l y , s e m i - e m p i r i c a l methods e m p i r i c a l l y p a r a m e t e r i z e or even n e g l e c t some of the computing-time-consuming t w o - e l e c t r o n i n t e g r a l s . Some ab i n i t i o and s e m i - e m p i r i c a l MO programs a r e d e s c r i b e d and t h e i r performance e v a l u a t e d i n c h a p t e r 4. 2.2B Breakdown of Koopmans' theorem Koopmans' theorem o c c a s i o n a l l y f a i l s t o p r e d i c t the o r d e r i n g of the i o n i z a t i o n p r o c e s s e s i n a m o l e c u l e deduced from r e l a t e d PE s p e c t r a and some o t h e r r e l a t e d e x p e r i m e n t a l and t h e o r e t i c a l d a t a . T h i s f a i l u r e i s o f t e n r e f e r r e d t o as the "breakdown of Koopmans' theorem". A c l a s s i c example concerns the i o n i z a t i o n of N 2 ( 3 ) . The HF r e s u l t s p r e d i c t t h a t the f i r s t 13 IP i s due t o 1nJ,1. In f a c t i t i s due t o 3cg 1 ( F i g . 1). The reasons f o r t h i s k i n d of breakdown have been reviewed (4) and a r e o u t l i n e d below: a. The f r o z e n o r b i t a l a p p r o x i m a t i o n mentioned i n the p r e c e d i n g s e c t i o n may cause e r r o r s . A f t e r i o n i z a t i o n , r e o r g a n i z a t i o n of the r e m a i n i n g e l e c t r o n s w i l l d e c r e ase the e l e c t r o n i c energy of the i o n (eqn. 2.8). Hence, the r e o r g a n i z a t i o n c o r r e c t i o n i s a n e g a t i v e q u a n t i t y and s h o u l d be added t o the "Koopmans' I P " ( n e g a t i v e of the c o r r e s p o n d i n g o r b i t a l energy) . b. Two o t h e r i n t r i n s i c a p p r o x i m a t i o n s of the HF-SCF method i n t r o d u c e more e r r o r s . The n o n r e l a t i v i s t i c n a t u r e of the H a m i l t o n i a n i n d i c a t e s t h a t r e l a t i v i s t i c c o r r e c t i o n s s h o u l d be t a k e n i n t o a c c o u n t . S i n c e the n e u t r a l i s r i c h e r by one e l e c t r o n than the c a t i o n , the r e l a t i v i s t i c energy i n the former i s the l a r g e r . T h i s means t h a t upon c o r r e c t i n g the I P ' s f o r r e l a t i v i s t i c e f f e c t s one a r r i v e s a t h i g h e r v a l u e s . However, f o r v a l e n c e e l e c t r o n s , t h i s c o r r e c t i o n i s s m a l l r e l a t i v e t o t h a t f o r c o r e e l e c t r o n s . The t y p i c a l r e l a t i v i s t i c c o r r e c t i o n s f o r v a r i o u s c a t i o n i c s t a t e s of some atoms a r e e s t i m a t e d from the d a t a of Ref. 5, and summarized i n T a b l e 1. The e f f e c t on the o r d e r i n g of the i o n i z a t i o n p r o c e s s e s induced by uv r a d i a t i o n i s e x p e c t e d t o be v e r y s m a l l . 14 1 2 3 e. d. 2 1 Fig. 1 16 20 17 18 19 IONIZATION POTENTIALS(eV) The experimental Hel PE spectrum (a.) and theoretical  PE spectra of N^  predicted by h. HF-SP.F calculations with Koopmans' theorem (Ref. 3),  r. ASHF method (Ref. 3). d. the RSPT method (Ref.11 ), e. the outer valence type Green's function method (Ref. 6a) 15 TABLE 1 R e l a t i v i s t i c c o r r e c t i o n s f o r IP's°of some atoms" I s " 1 2s" 1 2 p _ 1 3s" 1 3 p _ 1 Ar 16.67 3.20 1.17 0.35 0.10 Mg 3.11 0.46 0.14 0.02 Ne 1.45 0.19 0.05 Be 0.03 0.002 He 0.001 a. A l l values i n eV. b. Ref. 5. 16 More i m p o r t a n t , however, i s the e l e c t r o n c o r r e l a t i o n problem due t o the ' s e l f - c o n s i s t e n t f i e l d ' t r e a t m e n t . The e l e c t r o n - e l e c t r o n r e p u l s i o n between a p a r t i c u l a r e l e c t r o n and a l l the o t h e r e l e c t r o n s i s a pproximated by the i n t e r a c t i o n between t h i s e l e c t r o n and a smooth f i e l d which r e p r e s e n t s the average s p a t i a l d i s t r i b u t i o n of the o t h e r e l e c t r o n s , but not the e l e c t r o n and the o t h e r e l e c t r o n s i n s t a n t a n e o u s l y . In o t h e r words, the HF-SCF method t a k e s i n t o account the i n t e r a c t i o n s between e l e c t r o n s o n l y i n an average way. However, the motions of e l e c t r o n s a r e a c t u a l l y c o r r e l a t e d w i t h each o t h e r . There i s v i r t u a l l y a Coulomb h o l e s u r r o u n d i n g each e l e c t r o n and the p r o b a b i l i t y of f i n d i n g a n o t h e r e l e c t r o n i s s m a l l . The n e g l e c t of t h i s c o r r e l a t i o n makes the r e p u l s i o n and hence the t o t a l e l e c t r o n i c energy (eqn. 2.6) h i g h e r than the a c t u a l v a l u e (the exchange i n t e g r a l s t a k e c a r e of the c o r r e l a t i o n of e l e c t r o n s w i t h the same s p i n ) . The c o r r e l a t i o n energy (the c o r r e s p o n d i n g c o r r e c t i o n ) i s a n e g a t i v e q u a n t i t y , and s i n c e t h e r e i s one more e l e c t r o n i n a n e u t r a l m o l e c u l e than i t s s i n g l y charged c a t i o n , the c o r r e l a t i o n c o r r e c t i o n i s a p o s i t i v e v a l u e t o be added t o the IP a p p r o x i m a t e d by Koopmans' theorem. In s h o r t , the IP c o r r e s p o n d i n g t o the i o n i z a t i o n of one e l e c t r o n from o r b i t a l i i s I P C - C-€L-) - R + C 2.io where rr^ i s the o r b i t a l energy of o r b i t a l i , R and C are the c o r r e c t i o n s due t o the r e o r g a n i z a t i o n and the c o r r e l a t i o n e f f e c t s " r e s p e c t i v e l y . These two c o r r e c t i o n s t e n d t o c a n c e l each o t h e r due t o t h e i r o p p o s i t e s i g n s . However, t h i s i s not always 1 7 t r u e and i n some c a s e s , the i n c o m p l e t e c a n c e l l a t i o n may even s w i t c h the o r d e r i n g p r e d i c t e d by Koopmans' theorem and produce a 'breakdown'. Hence, i n o r d e r t o o b t a i n a c c u r a t e t h e o r e t i c a l I P ' s , the R and C v a l u e s have t o be e v a l u a t e d . The r e o r g a n i z a t i o n c o r r e c t i o n , R, can be i n c l u d e d by the ASCF method I Pi = EHF-SCF of cation i " EHF-SCF of neutral molecule 2 J 1 i n s t e a d of j u s t u s i n g the n e g a t i v e of the energy of o r b i t a l i . However, the r e s u l t s remain a f f e c t e d by the c o r r e l a t i o n e r r o r s ( F i g . 1). The b e s t s o l u t i o n i s hence t o go beyond the HF-SCF a p p r o x i m a t i o n . The two most w i d e l y used methods a r e the Green's f u n c t i o n t e c h n i q u e s (6) and the e s t i m a t i o n of the c o r r e c t i o n s by the R a y l e i g h - S c h r o d i n g e r p e r t u r b a t i o n t h e o r y (RSPT) ( 7 ) . The former method makes use of the many-body t e c h n i q u e s of second q u a n t i z a t i o n , by which the R and C terms are a t t r i b u t e d t o many-body e f f e c t s a c t i n g upon the o n e - p a r t i c l e - o n e - h o l e p r o c e s s ( d i r e c t i o n i z a t i o n ) . An I P , b o t h i t s p o s i t i o n and r e l a t i v e i n t e n s i t y , i s d i r e c t l y r e l a t e d t o a p o l e of the s e l f - e n e r g y p a r t of the Green's f u n c t i o n . The o r i g i n a l f o r m u l a t i o n of t h i s method i s from the t w o - p a r t i c l e - h o l e - R a n d o m - P h a s e - A p p r o x i m a t i o n (2ph-RPA) ( 6 a ) . In p r a c t i c e , a s i m p l i f i e d v e r s i o n has been de v e l o p e d t o c a l c u l a t e a c c u r a t e I P ' s f o r o u t e r v a l e n c e e l e c t r o n s and i s c a l l e d the o u t e r v a l e n c e type Green's f u n c t i o n method, which has been used s u c c e s s f u l l y f o r more than 70 m o l e c u l e s (6f and r e f e r e n c e s c i t e d t h e r e i n ) . The RSPT method i s a s i m p l e r approach t o the s o l u t i o n . The o r d i n a r y t h i r d - o r d e r RSPT i s used t o c a l c u l a t e the c o r r e c t i o n s 18 s t a r t i n g w i t h the SCF r e s u l t s t h a t a r e c l o s e t o the HF l i m i t . S i n c e t h i s t e c h n i q u e has been a p p l i e d t o some s t u d i e s i n t h i s t h e s i s , the t h e o r y i n v o l v e d i s summarized i n the next s e c t i o n . 2.2C P e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' theorem S t a r t i n g w i t h the HF-SCF r e s u l t s of a m o l e c u l e , o r d i n a r y t h i r d - o r d e r RSPT i s used t o f o r m u l a t e the e x p r e s s i o n f o r the c o r r e l a t i o n energy of the p a r e n t m o l e c u l e and the r e o r g a n i z a t i o n and c o r r e l a t i o n e n e r g i e s of the c a t i o n s (7a). The c o n v e n t i o n f o r the i n d i c e s used i n the f o l l o w i n g d e r i v a t i o n i s k, 1,... f o r o c c u p i e d s p i n o r b i t a l s of the p a r e n t m o l e c u l e , and K,L,... f o r v i r t u a l o r b i t a l s . The i n d i c e s r , s , . . . w i l l be r e s e r v e d f o r o c c u p i e d s p i n o r b i t a l s which a r e not 4^ (the o r b i t a l from where the i o n i z e d e l e c t r o n i s e j e c t e d ) . The n o r m a l i z e d approximate ground s t a t e w a v e f u n c t i o n of a nondegenerate c l o s e d - s h e l l p a r e n t m o l e c u l e w i t h 2n e l e c t r o n s can be w r i t t e n as a s i n g l e d e t e r m i n a n t b u i l t from a s e t of c a n o n i c a l HF-SCF s p i n o r b i t a l s (<fj>) p where P i s a p e r m u t a t i o n of 1,2,...,2n and (-1) i s +1 or -1 f o r even or odd p e r m u t a t i o n s , r e s p e c t i v e l y . <^> 's a r e some t r i a l " f u n c t i o n s i n i t i a l l y ( e .g. the c o r r e s p o n d i n g r e s u l t s of the extended H u c k e l method). SCF r e s u l t s a r e o b t a i n e d by i t e r a t i o n 19 of t h e s e 's w i t h the HF H a m i l t o n i a n o p e r a t o r f : {<Pk = ek(pk 2.i3 where f (1) = h d ) + g(1) 2.14 h i s the o n e - e l e c t r o n c o r e H a m i l t o n i a n (eqn. 2.3); and g i s the t w o - e l e c t r o n i n t e r a c t i o n H a m i l t o n i a n : where P 1 2 i s a p e r m u t a t i o n of 1 and 2. The u n p e r t u r b e d H a m i l t o n i a n i s thus H°= H f c o --k%<<pta>Jg <»$«>> = f f C O - G 2.16 where G = X < ^  CO , $ CO cf) co) 2.17 S i n c e the t r u e e l e c t r o n i c H a m i l t o n i a n i s 2.18 the H a m i l t o n i a n c o r r e s p o n d i n g t o the p e r t u r b a t i o n due t o e l e c t r o n c o r r e l a t i o n of the p a r e n t m o l e c u l e i s thus H' = H - H 0 -*J A c c o r d i n g t o the o r d i n a r y t h i r d - o r d e r RSPT, the p e r t u r b e d system 2.19 i s d e s c r i b e d by H £ = E £ 2.20 <J 2* <J° + vji 2.21 E ~ E° + E 1 + E 2 + E 3 2.22 These z e r o - o r d e r t o t h i r d - o r d e r e n e r g i e s can be e x p r e s s e d as 20 E° = < £ ° , H<F> 2-23  E 1 - < f , H ' £ - > 2 - 2 * = G -2G + G = 0 E2 = <<£°, H ^ 4 > 2.25 *' -tZ^H'&y ^ 2-26 Hence the e x p a n s i o n of v£ i n terms of some e x c i t e d w a v e f u n c t i o n s ( e . g . J ^ , a s i n g l e d e t e r m i n a n t l i k e ^ but w i t h C^and (pL r e p l a c i n g (p and (p^ ) w i l l g i v e a s o l u t i o n f o r the e l e c t r o n c o r r e l a t i o n energy. A c c o r d i n g t o the B r i l l o u i n theorem ( 8 ) , s i n g l e e x c i t a t i o n s w i l l not c o n t r i b u t e . Thus the f i r s t o r d e r w a v e f u n c t i o n i s a summation of terms c o r r e s p o n d i n g t o double e x c i t a t i o n s : * A K<L * U where 2.28 By eqn. 2.25 and 2.26 the e x p r e s s i o n s f o r the second- and t h i r d - o r d e r e n e r g i e s a r e k<JL «L U 2.30 U i K<L men M < ^ , L 7 T R L ^ S i m i l a r t r e a t m e n t can be made f o r the c a t i o n . The 21 n o r m a l i z e d u n p e r t u r b e d w a v e f u n c t i o n f o r c a t i o n q ( e l e c t r o n i n s p i n o r b i t a l i s e j e c t e d ) i s w r i t t e n , based on the f r o z e n o r b i t a l a p p r o x i m a t i o n , as Hence, the z e r o - o r d e r energy i s E° = E° - cr^ , 2.33 the f i r s t - o r d e r energy v a n i s h e s by s e t t i n g < > f-j^ = E^ 2 , 3 4 and the second- and t h i r d - o r d e r e n e r g i e s can be e v a l u a t e d by e q u a t i o n s s i m i l a r t o eqn. 2.25 and 2.26. In c o n t r a s t t o the par e n t m o l e c u l e , the f i r s t - o r d e r w a v e f u n c t i o n c o n s i s t s of s i n g l e as w e l l as double e x c i t a t i o n s ( s i n g l e e x c i t a t i o n s of the type r t o q do not c o n t r i b u t e ) : where the B c o e f f i c i e n t s a r e g i v e n by Bl = c e r - e K Y' c vK<?<?r - v.oro^ 2 . 3 6 2.37 A f t e r computing the second- and t h i r d - o r d e r e n e r g i e s f o r both the p a r e n t m o l e c u l e and the c a t i o n , a b e t t e r a p p r o x i m a t i o n of t he IP can be e v a l u a t e d i n s e v e r a l ways : a. A E ( 3 ) : The IP i s approx i m a t e d as the d i f f e r e n c e i n the p a r t i a l sums - -eq + CE?-E*) + CE?-E*y = - e ? + *E* + *E3 2-39 22 b. S c a l e d p e r t u r b a t i o n : S c a l e d p e r t u r b a t i o n (9, 10) i s a common method t o improve the r a t e of convergence. The u n p e r t u r b e d H a m i l t o n i a n i s s c a l e d by (_)° = (["' u" 2.40 so t h a t — — , _ i 6 H ' - H - H ° - H + C i - » L ) H 2.41 The r e s u l t s of t h i s s c a l i n g a r e (7a) £~°= <£° 2.42 E~°= EVE'-Y 1 2.43 ^ 2.44 The s c a l e d w a v e f u n c t i o n i s thus £ * £° + ^ * 4°-14* 2.47 w i t h the energy e x p e c t a t i o n v a l u e as - r° rt, f / f ' C £ 3 - E a ) 2.48 M i n i m i z i n g t h i s e x p e c t a t i o n v a l u e w i t h r e s p e c t t o the s c a l e f a c t o r g i v e s <H;> = e % 5 1 + . C E 1 2.49 2.50 f C £ 3- £ 33 - ft £ 3- 5 a J % * C 5 Q V<£ f £ >r f Hence, the IP can be a p p r o x i m a t e d as iPf = ^ H > = - e ? - f C ? E ? i - c e i , 2.51 However, the a p p l i c a t i o n of the v a r i a t i o n p r i n c i p l e g uarantees 23 the j u s t i f i c a t i o n of t h i s e x p r e s s i o n o n l y f o r the lowest s t a t e of each symmetry. c. A ( E & ^ ) and (AE) 6* : Other ways t o choose the s c a l e f a c t o r are t o make v a n i s h or t o s e t the f i r s t d e r i v a t i v e of the p a r t i a l sum w i t h r e s p e c t t o ^ t o z e r o . Both of them l e a d t o a geometric a p p r o x i m a t i o n (GA) f o r the energy E * E** = E° + E 1 ->- E / o - x ; 2.53 where x = E 3 / E 2 Hence, the IP can be w r i t t e n as IP ? = *CE**) = -6 ? + E ? Vcf-x) - £ 7 c / - x ^ 2.54 A s i m i l a r g e o m e t r i c a p p r o x i m a t i o n e x p r e s s i o n can be s e t as 2.55 where y = ^  E 3 / ^  E 2 Some e m p i r i c a l s t u d i e s (7) have shown t h a t t h e v a r i a t i o n a l approach of the s c a l e d p e r t u r b a t i o n i s the b e s t method i n p r e d i c t i n g IP f o r the low e s t s t a t e of each symmetry. However, i n g e n e r a l , the average e r r o r s of the AE(3), A(E ) and (AE) methods a r e q u i t e s i m i l a r and a p p r o x i m a t e l y 0.5eV f o r a double z e t a b a s i s s e t . The use of a 1-i"zeta b a s i s s e t o n l y i n c r e a s e s the average e r r o r by about 0.1eV ( 7 b ) . The method has a l s o been 24 shown t o be e s s e n t i a l l y e q u i v a l e n t , as f a r as the a c c u r a c y of the r e s u l t s i s c o n c e r n e d , t o the Green's f u n c t i o n method ( 7 c ) . A c c u r a t e I P ' s have thus been c a l c u l a t e d f o r more than 30 m o l e c u l e s by the RSPT method. The breakdown of Koopmans' theorem has been c o n f i r m e d f o r m o l e c u l e s such as N 2 ( 1 1 ) , F 2 0 ( 7 a ) , HOF ( 1 2 ) , HNO, FNO, 0 3 ( 1 3 ) , C1 20, HOC1, FOCI ( 1 4 ) , HN 3 ( 1 5 ) , HNF 2 ( 1 6 ) , and CH3NO ( 1 7 ) . The HF r e s u l t s assuming Koopmans' theorem ( 1 1 ) , the ASCF r e s u l t s ( 3 ) , the Green's f u n c t i o n r e s u l t s ( 6 a ) , and the RSPT r e s u l t s (11) f o r the I P ' s of N 2 a r e p l o t t e d i n F i g . 1, t o g e t h e r w i t h our e x p e r i m e n t a l Hel PE spectrum. T h i s p l o t shows a t y p i c a l example of the breakdown of Koopmans' theorem and the r e s u l t s of d i f f e r e n t approaches t o r e s o l v e t h i s problem. The r e s u l t s o b t a i n e d by u s i n g the Green's f u n c t i o n and RSPT method i n s t u d y i n g the breakdown of Koopmans' theorem l e a d t o some v e r y u s e f u l c o n c l u s i o n s ( 1 3 ) : a. The p r e s e n c e of any l o w - l y i n g v i r t u a l o r b i t a l s s u g g e s t s a c o n s i d e r a b l e p o s s i b l i l i t y of the breakdown of Koopmans' theorem. b. I f the s e p a r a t i o n of e and n type o r b i t a l s i s p o s s i b l e , e.g. f o r m o l e c u l e s h a v i n g C s symmetry, a l o w - l y i n g v (<*) v i r t u a l o r b i t a l , t o g e t h e r w i t h some n (<*) o c c u p i e d o r b i t a l s , i n t r o d u c e s l a r g e c o r r e c t i o n s t o Koopmans' theorem f o r the i o n i z a t i o n from a (ir) o r b i t a l s . These nonuniform s h i f t s o f t e n cause the breakdown of Koopmans' theorem. 25 2 . 2D The semi-empi r i c a l HAM/3 method The HAM/3 (Hydrogenic Atoms i n M o l e c u l e s method, v e r s i o n 3) method (18) i s a c o m p l e t e l y d i f f e r e n t approach t o the af o r e m e n t i o n e d problem i n p r e d i c t i n g I P ' s , b e i n g an a p p l i c a t i o n of S l a t e r ' s s h i e l d i n g c o n c e p t . The method i s p a r a m e t e r i z e d by e x p e r i m e n t a l r e s u l t s from atomic s p e c t r o s c o p y and PES and may be used t o c a l c u l a t e , f o r i n s t a n c e , I P ' s , e l e c t r o n a f f i n i t i e s , e x c i t a t i o n e n e r g i e s and CI between e x c i t e d c o n f i g u r a t i o n s . The advantages of t h i s method a r e t h a t most of the c o r r e l a t i o n energy i s i n c o r p o r a t e d i n t o t he S l a t e r s h i e l d i n g c o n s t a n t s , and t h a t use of Koopmans' theorem i s a v o i d e d i n IP c a l c u l a t i o n s . As an e x t e n s i o n of the quantum-mechanical r e s u l t s on the hydrogen atom, S l a t e r (19, 20) i n t r o d u c e d an e l e c t r o n s h i e l d i n g c o n c e p t , and s e t the energy of an e l e c t r o n » i n an atom A as E ^ - - i - V 2.56 where f ^ - C Z , - S^/tX^ 2.57 i s t he o r b i t a l exponent of the atomic o r b i t a l , Z/i i s n u c l e a r c h a r g e , Sj^ i s t h e s h i e l d i n g , n ^ i s the p r i n c i p a l quantum number. The s h i e l d i n g depends on the o t h e r e l e c t r o n s , V ' s , i n the atom and a s e t of s h i e l d i n g c o n s t a n t s , , has been recommended (20) . In the HAM/3 method, by analogy t o eqn. 2.56, the t o t a l energy of an atom i s w r i t t e n as where f ^ ^ i s the d e n s i t y m a t r i x element, which d e s c r i b e s the 26 number of e l e c t r o n s i n o r b i t a l v. The s h i e l d i n g c o n s t a n t , 6~>^, however, i s e x p r e s s e d as a s i m p l e f u n c t i o n as 0 ^ - - C byi + 2/))/%^ 2 , 5 9 where a ^ , hyj. and Cyu. a r e c o n s t a n t s . The s h i e l d i n g c o n s t a n t s a r e then d e t e r m i n e d by f i t t i n g t he t o t a l e n e r g i e s of 311 d i f f e r e n t atomic s p e c i e s , h a v i n g n = 1 or 2, w i t h eqn. 2.59 ( 1 8 ) . A more r e c e n t t h e o r e t i c a l s t u d y has shown t h a t t h i s e x p r e s s i o n i s e q u i v a l e n t t o the a d d i t i o n of an e l e c t r o n c o r r e l a t i o n term t o the HF energy e x p r e s s i o n ( 2 1 ) . Hence, c o r r e l a t i o n e f f e c t i s a u t o m a t i c a l l y i n c l u d e d i n the HAM/3 method. F u r t h e r e x t e n s i o n of the i d e a of eqn. 2.58 g i v e s the energy e x p r e s s i o n of a m o l e c u l e as 2.60 The f i r s t term /^5*-ZfJu*^ d e s c r i b e s the energy of the e l e c t r o n i c charge Np. , as i n the atomic c a s e . The second term Tju.y^u)' • ~^C~Sjlt'Sj')C -/ ) d e s c r i b e s the e l e c t r o n i c charge ^wS^y, where S^v i s the o v e r l a p p i n g m a t r i x element. f ^ v i s an e m p i r i c a l f a c t o r which depends on the t y p e s of bonding ( i . e . , SMJ; ) . T h i s term i s t h u s c l o s e l y r e l a t e d t o the bonding i n t h e m o l e c u l e . The t h i r d term, QA QB^AB ' * s a c o r r e c t i o n term a r i s i n g from the f a c t t h a t o n l y the r e p u l s i o n between e l e c t r o n s on the same atom i s i n c l u d e d i n the f i r s t two terms. and Q g a r e the g r o s s atomic c h a r g e s on atoms A and B, and TAB i s an e m p i r i c a l f a c t o r . 27 With t h i s energy e x p r e s s i o n f o r the m o l e c u l e , the Fock m a t r i x can be c o n s t r u c t e d by p ,= 2.61 Hence the o r b i t a l energy €c and the AO c o e f f i c i e n t s C ^ of the MO ^""Z^ui^can be e v a l u a t e d . In c a l c u l a t i n g I P ' s , S l a t e r (22) has demonstrated t h a t the o r b i t a l energy c o r r e s p o n d i n g t o a s p i n o r b i t a l w i t h o c c u p a t i o n number 1/2 ( h a l f w a y between 1 f o r the n e u t r a l ground s t a t e and 0 f o r the p o s i t i v e i o n s t a t e ) c l o s e l y a p p r o x i m a t e s the d i f f e r e n c e between two s e p a r a t e l y o p t i m i z e d t o t a l e n e r g i e s ( i . e . ASCF). T h i s v i r t u a l s t a t e h a v i n g an o c c u p a t i o n number 1/2 i s a l s o c a l l e d the t r a n s i t i o n s t a t e . T h i s concept i s used i n the HAM/3 method t o c a l c u l a t e I P ' s ( 2 3 ) . Hence, r e o r g a n i z a t i o n of the i o n s t a t e has been i n c l u d e d . F u r t h e r g e n e r a l i z a t i o n of t h i s concept i n d i c a t e s t h a t i f the removal of h a l f an e l e c t r o n i s e v e n l y d i s t r i b u t e d over the M m o l e c u l a r o r b i t a l s of i n t e r e s t ( ' d i f f u s e i o n i z a t i o n ' ( 2 3 ) ) , the r e s u l t a n t o r b i t a l e n e r g i e s c l o s e l y a p proximate the c o r r e s p o n d i n g I P ' s . T h i s a p p r o x i m a t i o n , j u s t i f i e d b o th e m p i r i c a l l y (23) and t h e o r e t i c a l l y ( 2 4 ) , saves computing e f f o r t s i n c e a l l I P ' s a r e c a l c u l a t e d by a s i n g l e SCF c a l c u l a t i o n . However, the HAM/3 method was s e v e r e l y c r i t i c i z e d a t i t s i n i t i a l s t a g e s (25, 2 6 ) . Of p a r t i c u l a r c o n c e r n , of c o u r s e , i s the j u s t i f i c a t i o n of the energy e x p r e s s i o n of the mo l e c u l e (eqn. 2.60). T h i s p o l e m i c has been s e t t l e d by a t r a n s f o r m a t i o n of the u s u a l LCAO HF-SCF energy e x p r e s s i o n t o a s i m i l a r form as the HAM/3 energy e x p r e s s i o n ( 2 1 ) . T h i s comparison has 28 demonstrated the v a l i d i t y of the HAM/3 method and suggested f u r t h e r improvement l e a d i n g t o an improved HAM/4 v e r s i o n ( 2 1 ) . The HAM/3 computer program i s now a v a i l a b l e from QCPE (Quantum C h e m i s t r y Program Exchange c e n t e r a t I n d i a n a U n i v e r s i t y ) (27) and has been used w i t h s u c c e s s (see Chapter 4 and r e f e r e n c e s c i t e d i n Ref. 2 7 ) . 2.2E V a l e n c e - e l e c t r o n shake-up p r o c e s s e s The t r e a t m e n t i n the p r e c e d i n g s e c t i o n s i s based on the assumption t h a t t h e r e i s a one-to-one co r r e s p o n d e n c e between the e x p e r i m e n t a l I P ' s and the AO's or MO's. T h i s s i m p l e p i c t u r e ( s o - c a l l e d ' q u a s i p a r t i c l e p i c t u r e ' ) i s not t r u e i n some ca s e s where shake-up, s h a k e - o f f or Auger p r o c e s s e s e t c . , are i m p o r t a n t . S i n c e the l a t t e r two p r o b a b l y do not occur i n the v a l e n c e - e l e c t r o n r e g i o n , some b r i e f remarks on shake-up p r o c e s s e s w i l l be made. A shake-up p r o c e s s o c c u r s when an e l e c t r o n i s i o n i z e d t o g e t h e r w i t h a s i m u l t a n e o u s e l e c t r o n e x c i t a t i o n from an o c c u p i e d o r b i t a l t o a v i r t u a l o r b i t a l . T h i s r e s u l t s i n one e l e c t r o n e j e c t e d and the second promoted t o a v i r t u a l o r b i t a l . S i n c e the e l e c t r i c d i p o l e o p e r a t o r i s a o n e - e l e c t r o n o p e r a t o r , the c o r r e s p o n d i n g t r a n s i t i o n moment of a t w o - e l e c t r o n p r o c e s s such as a shake-up p r o c e s s i s z e r o ( 2 8 ) . The most s t r a i g h t f o r w a r d t h e o r e t i c a l approach t o a shake-up p r o c e s s i s CI . M i x i n g the c o n f i g u r a t i o n l e a d i n g t o the t w o - e l e c t r o n p r o c e s s (one e l e c t r o n i o n i z e d and another e x c i t e d ) w i t h the 29 c o n f i g u r a t i o n c o r r e s p o n d i n g t o a d i r e c t i o n i z a t i o n ( p r i m a r y h o l e c o n f i g u r a t i o n ) w i l l o b v i o u s l y c o n t r i b u t e t o the t r a n s i t i o n p r o b a b i l i t y of the shake-up p r o c e s s . T h i s i s a l s o r e f e r r e d t o as ' i n t e n s i t y b o r r o w i n g ' from the p r i m a r y h o l e . As a g e n e r a l r u l e f o r c o n f i g u r a t i o n m i x i n g , the two c o n f i g u r a t i o n s have t o poss e s s the same symmetry and be c l o s e enough i n energy t o i n t e r a c t . The most s u c c e s s f u l t r e a t m e n t of shake-up p r o c e s s e s i s the 2ph-TDA v e r s i o n of the many-body Green's f u n c t i o n method ( 6 ) . T h i s has been e x t e n s i v e l y r e v i e w e d (6) and more than 50 mo l e c u l e s i n c l u d i n g , N 2 , CO, C 0 2 , CS, C S 2 , P 2 , PN, H 2S, PH 3, HCN, HCOOH, n i n e h y d r o c a r b o n s , N 2O f l, N0 2 and S 2 N 2 , have been s t u d i e d (see r e f e r e n c e s c i t e d i n Ref. 6b and 6 f ) . These r e s u l t s show t h a t complete breakdown of the q u a s i p a r t i c l e p i c t u r e i s q u i t e common i n the i n n e r v a l e n c e r e g i o n (20 - 50eV) where the i n t e n s i t y of a main peak p a r t i t i o n s i n t o s e v e r a l s a t e l l i t e peaks of some shake-up p r o c e s s e s , and the main peak and s a t e l l i t e peaks a r e no l o n g e r d i s t i n g u i s h a b l e . S t u d i e s of CS ( 2 9 ) , CS 2 ( 3 0 ) , PN (31, 3 2 ) , P 2 (32, 6 b ) , b u t a t r i e n e , t r a n s - b u t a d i e n e , benzene ( 3 3 ) , N 20„ ( 3 4 ) , S 2 N 2 ( 3 5 ) , and N0 2 (36) i n d i c a t e t h a t shake-up p r o c e s s e s may be i m p o r t a n t ( s a t e l l i t e l i n e w i t h r e l a t i v e i n t e n s i t y h i g h e r than 10%) even i n the Hel r e g i o n . Extreme c a s e s of breakdown occur i n CS, P 2, N 2O f t and S 2 N 2 . A more d e t a i l e d shake-up study of N 2O f l i s d e s c r i b e d i n Chapter 9. The o c c u r r e n c e of s a t e l l i t e peaks i n the Hel r e g i o n g i v e s an im p o r t a n t warning t o PE s p e c t r o s c o p i s t s , s i n c e shake-up p r o c e s s e s have p r e v i o u s l y u s u a l l y been i g n o r e d i n 30 the i n t e r p r e t a t i o n of Hel PE s p e c t r a . T h i s s i m p l i f i c a t i o n i s most l i k e l y t o be err o n e o u s i n the presence of low l y i n g v i r t u a l o r b i t a l ( s ) . The l o w e r i n g of the p o s s i b l e e l e c t r o n e x c i t a t i o n e n e r g i e s may w e l l s h i f t the s a t e l l i t e peaks down t o the Hel r e g i o n , and the i n c r e a s e i n CI w i l l enhance the i n t e n s i t i e s of the s a t e l l i t e s . T h i s c o n c l u s i o n i s demonstrated by the shake-up s t u d i e s i n Chapter 8 and Chapter 9. V a l e n c e - e l e c t r o n shake-up p r o c e s s e s have a l s o been i n v e s t i g a t e d by the HAM/3 method (37, 3 8 ) . CI c a l c u l a t i o n s a r e performed and the p o s i t i o n s and i n t e n s i t i e s of the shake-up peaks a re e s t i m a t e d . T h i s method has been used i n t h i s t h e s i s t o s t u d y shake-up p r o c e s s e s i n CH3NO and N 2O a. 31 2.3 P r i n c i p l e s of quadrupole mass s p e c t r o m e t r y The h i s t o r i c a l development and the g e n e r a l p r i n c i p l e s of quadr u p o l e mass s p e c t r o m e t r y have been w e l l documented ( 3 9 ) . The schematic diagram of a q u a d r u p o l e mass s p e c t r o m e t e r i s shown i n F i g . 2. Four p a r a l l e l rods a r e used t o s e t up a q u a d r u p o l e . I d e a l l y the rod s h o u l d be h y p e r b o l i c i n c r o s s s e c t i o n , however c i r c u l a r rods a re found t o g i v e a c c u r a t e r e s o l u t i o n . I d e a l l y , r r o d . = 1 « 1 4 8 r o ( F i g . 2 ). A d.c. v o l t a g e U and a r . f . v o l t a g e V c o s o t a r e imposed a c r o s s o p p o s i t e p a i r s of r o d s . For a g i v e n s e t of c o n d i t i o n s of v o l t a g e s , u, and rod s e p a r a t i o n , an i o n s p e c i e s w i l l have a bounded t r a j e c t o r y i n the x and y d i r e c t i o n s and t r a v e l w i t h i n the space between the e l e c t r o d e s u n t i l i t emerges from an e x i t a p e r t u r e i n t o a d e t e c t o r . Ions of o t h e r m/e r a t i o s a r e f i l t e r e d out i n the x or y d i r e c t i o n s , and are l o s t . The p o t e n t i a l i n a q u a d r u p o l e f i e l d can be e x p r e s s e d as where a, b and c a r e c o n s t a n t s . I n s i d e the quad r u p o l e mass f i l t e r , the p o t e n t i a l i n the y d i r e c t i o n i s the n e g a t i v e of t h a t i n the x d i r e c t i o n , and t h e r e i s no f i e l d i n z d i r e c t i o n . B e s i d e s , we have 2.62 c£>o = U - Vcosut , 2.63 and a + b + c = 0 because t h e r e i s no space c h a r g e . Hence a = -b = 1 / 2 r 0 2 and c = 0. U - Vcoscot ' 1 Fig. 2 Schematic diagram of a quadrupole mass spectrometer to ro 33 The f o r c e s on a charged p a r t i c l e i n s i d e the mass f i l t e r a re then Fx = - € l f = - ( U - l W ; - ^ 2.64 Fy =-*^r - C U - V / c o s ^ ) - ^ 2.65 F2 = O 2.66 The e q u a t i o n s of motion a r e t h u s x + Ck, ~ 2^coscot ) X = O 2.67 where k( = a n d ' 2.69 k i = — 2 . 7 0 These second-order d i f f e r e n t i a l e q u a t i o n s a r e c a l l e d M a t h i e u e q u a t i o n s (40) and t h e i r s t a n d a r d s o l u t i o n s a r e p l o t t e d t o g e t h e r i n F i g . 3 ( 3 9 ) . The shaped a r e a i s the s o - c a l l e d ' s t a b l e r e g i o n ' where x or y remains f i n i t e as t i n c r e a s e s t o i n f i n i t y , i . e . , the t r a j e c t o r y i s bounded i n the x or y d i r e c t i o n . Hence, the o v e r l a p p i n g s t a b l e r e g i o n of both x and y r e p r e s e n t s the c o n d i t i o n s under which the i o n t r a j e c t o r y i s bounded. The area near the o r i g i n i s the normal r e g i o n of o p e r a t i o n . S t a b l e a r e a s h a v i n g l a r g e v a l u e s of k, and k 2 g i v e i o n motion w i t h l a r g e e x c u r s i o n s compared t o the i n i t i a l i o n d i s p l a c e m e n t and r e q u i r e v e r y l a r g e c o n t a i n m e n t . The s t a b l e a r e a near the o r i g i n i s e n l a r g e d and shown i n F i g . 4 ( 3 9 ) . A mass-scan l i n e i s a s t r a i g h t l i n e p a s s i n g t h r o u g h the o r i g i n and i n t e r s e c t i n g the s t a b l e a r e a . The 34 Fig. 3 Solution of the Mathieu equations - s tab i l i t y diagrams  for the x and y directions. Illl stable region for x direction == stable region for y direction 35 Fig. 4 The stable region for both x and v directions near  the origin x s tab i l i t y boundary y s tab i l i t y boundary UllllJ: stable region for both x and y directions — - mass-scan l ine 3 6 r \ c o n d i t i o n f o r t h i s scan l i n e i s = - ^ 7 - = constant 2.71 The c h a r a c t e r i s t i c s of the mass-scan l i n e a r e t h a t i o n s of d i f f e r e n t m/e w i l l be spread out a l o n g the mass scan l i n e , and t h a t by v a r y i n g the magnitude of U and V, but keeping t h e i r r a t i o c o n s t a n t (or v a r y i n g u f o r a n o n l i n e a r r e s p o n s e ) , i o n s of d i f f e r e n t m/e can be brought i n t o the s t a b l e a r e a . By the shape of the s t a b l e r e g i o n , i t i s o b v i o u s t h a t the s l o p e of the mass-scan l i n e d e t e r m i n e s the r e s o l u t i o n . I f the mass spectrum i s scanned w i t h a mass-scan l i n e of c o n s t a n t s l o p e , the s e n s i t i v i t y w i l l remain the same but the r e s o l u t i o n (1/AM) w i l l d e c r e a s e w i t h the i n c r e a s e of the mass v a l u e , M. In o r d e r t o keep a c o n s t a n t r e s o l u t i o n t hroughout a mass spectrum, the mass-scan l i n e has t o be r o t a t e d towards the apex of the s t a b l e r e g i o n ( F i g . 4) w h i l e s c a n n i n g t o h i g h e r mass v a l u e s . A g a i n , from the shape of the s t a b l e a r e a , the s e n s i t i v i t y a t h i g h e r mass i s lower i n t h i s mode of o p e r a t i o n (which i s commonly a p p l i e d i n q u a d r u p o l e mass s p e c t r o m e t r y ) . 37 R e f e r e n c e s (Chapter 2) 1. T. Koopmans, P h y s i c a , 1(1933)104. 2. J.A. Po p l e and D.L. B e v e r i d g e , 'Approximate m o l e c u l a r o r b i t a l t h e o r y ' , M c G r a w - H i l l , New York (1970). 3. P.E. 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L i n d h o l m , i n p r e p a r a t i o n . 39. P.H. Dawson and N.R. Whetten, Dyn. Mass Spectrom., 2(1969) 1 . 40. N.W. M c L a c h l a n , 'Theory and a p p l i c a i t o n of M a t h i e u Func-t i o n s ' , O x f o r d U n i v e r s i t y P r e s s , O x f o r d (1951). 41 PART TT System Development 42 Chapter 3 Hardware Development 3.1 C o n s t r u c t i o n of the PE S p e c f r o m p r e r The d e s i g n of the o r i g i n a l PE s p e c t r o m e t e r has been f u l l y d e s c r i b e d i n the Ph.D. t h e s i s of S.T. Lee ( 1 ) . The s p e c t r o m e t e r performed r e l i a b l y over s e v e r a l y e a r s , but had c e r t a i n l i m i t a t i o n s f o r the u n s t a b l e s p e c i e s we wished t o s t u d y ; these a r e : (a) The i o n i z a t i o n chamber and the i o n i z a t i o n r e g i o n were of l i m i t e d a c c e s s i b i l i t y , t h e r e b y r e s t r i c t i n g the s i z e and even the a d a p t a t i o n of a c c e s s o r i e s , e.g. f u r n a c e s , d i s c h a r g e a s s e m b l i e s , n o z z l e s e t c . (b) L i m i t e d e f f i c i e n c y f o r f a s t pumping. (c) The sample i n l e t was d i r e c t e d toward the s l i t s of the a n a l y z e r e n t r a n c e r a t h e r the i o n i z a t i o n chamber pumping l i n e . T h i s o f t e n caused s e r i o u s c o n t a m i n a t i o n problems. A m o d i f i e d PE s p e c t r o m e t e r was t h e r e f o r e c o n s t r u c t e d w i t h t h e s e l i m i t a t i o n s i n mind, and w i t h the a d d i t i o n of a mass a n a l y s i s f a c i l i t y . S i n c e we a r e o f t e n d e a l i n g w i t h unknown s p e c i e s the mass a n a l y s i s of the i o n i z a t i o n chamber c o n t e n t s i s of paramount i m p o r t a n c e . I n t h i s case the m o d i f i c a t i o n s c e n t e r e d around the i n c o r p o r a t i o n of a q u a d r u p o l e mass s p e c t r o m e t e r and o t h e r a c c e s s o r i e s . A v e r t i c a l c r o s s - s e c t i o n of the PE s p e c t r o m e t e r through the i o n i z a t i o n r e g i o n , b i s e c t i n g the h e m i s p h e r i c a l e l e c t r o s t a t i c 43 a n a l y z e r , i s shown i n F i g . 1. Another s e c t i o n through the i o n i z a t i o n r e g i o n and the a x i a l a x i s of the l i g h t s o u r c e i s shown i n F i g . 2. The main components of t h i s s p e c t r o m e t e r a r e d i s c u s s e d below. A. The vacuum system The h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r and the h o u s i n g f o r the c h a n n e l e l e c t r o n m u l t i p l i e r (CEM) a r e pumped th r o u g h a 2" gate v a l v e (AIRCO) by a 2" o i l d i f f u s i o n pump (NRC) w i t h a pumping speed of 285 1/sec. The d i f f u s i o n pump i s backed by a r o t a r y pump (1397, Welch S c i e n t i f i c ) . An i o n i z a t i o n gauge (RG75K, VEECO) mounted between the s p e c t r o m e t e r and t h i s bottom d i f f u s i o n pump i s used t o mon i t o r the p r e s s u r e of the system. T y p i c a l base p r e s s u r e i s about 2x10" 6 t o r r and t y p i c a l o p e r a t i n g p r e s s u r e s a r e i n the range 0 . 6 - 2 . 0 x l 0 " 5 t o r r . The d i f f e r e n t i a l l y pumped i o n i z a t i o n chamber i s i s o l a t e d from the e l e c t r o n a n a l y z e r by the bottom p l a t e of the l e n s system ( the c e n t r a l a p e r t u r e 0.02"). Pumping of the i o n i z a t i o n chamber may be e f f e c t e d by t h r e e modes: (a) D i r e c t pumping w i t h a 2" d i f f u s i o n pump (NRC). (b) D i r e c t pumping w i t h a 6" d i f f u s i o n pump (NRC). (c) Mode (a) w i t h a d d i t i o n a l pumping f a c i l i t a t e d by a cryopump a t l i q u i d n i t r o g e n t emperature ( F i g . 3 ) . The pump o i l f o r the d i f f u s i o n pumps i s the Convalex-10 ( B e n d i x ) . A l l vacuum s e a l s a r e e f f e c t e d by V i t o n O - r i n g s . 44 pump nut. (diffusion pump) 1" seal e Fig. 1 The ionization chamber and the electron analyzer of  the PE spectrometer m n i 7 a r . i n n rhamhpr microwave power input ^ 3 f i 1 ter hoider I col 1imating capil lary q u a r t 7 t.uhe mirrnwayp Hi<;rhargp t.uhe to a rotary pump T-electron analyzer p r nt.hpr gases seal e Fig. 2 The ionization chamber and the l ight source unit of the PE spectrometer 46 Liquid nitrogen  reservoir L i q u i d inlet ni trogen PE/PIM Spectrometer Movable brass  tube To diffusion < pump 1" i ! i Seal e F i g . 3 The c o n s t r u c t i o n of the cryopump 47 B. The e l e c t r o n energy a n a l y z e r The e l e c t r o n energy a n a l y z e r c o n s i s t s of two major components: a l e n s system and a h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r . The f u n c t i o n of the l e n s system i s t w o f o l d . F i r s t of a l l , the t o p p l a t e s r e t a r d or a c c e l e r a t e the PE's a t the i o n i z a t i o n p o i n t such t h a t they have a f i n a l k i n e t i c energy matching the pass energy of the h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r . S e c o n d l y , the t h r e e element l e n s system f o c u s e s the e l e c t r o n s a t the i o n i z a t i o n p o i n t down t o the e n t r a n c e of the a n a l y z e r w i t h o u t a f f e c t i n g the chosen k i n e t i c energy. The second component, the h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r , s e t s up a p a s s i n g c r i t e r i o n such t h a t o n l y e l e c t r o n s h a v i n g a p a r t i c u l a r k i n e t i c energy (the pass energy) can pass through the a n a l y z e r and be d e t e c t e d . (a) The l e n s system: The d e t a i l e d c o n f i g u r a t i o n of the l e n s system i s shown i n F i g . 4. Some t y p i c a l o p e r a t i n g v a l u e s of the v o l t a g e s a r e l i s t e d i n T a b l e 1. The v o l t a g e s V, a p p l i e d t o the c i r c u l a r l i d w i t h an a p e r t u r e , V 2 on the c y l i n d r i c a l cup and V 3 on the f i r s t c i r c u l a r p l a t e w i t h an a p e r t u r e a r e u s u a l l y the same as the s c a n n i n g v o l t a g e . S i n c e t h e r e i s no p o t e n t i a l g r a d i e n t w i t h i n t h i s e n c l o s e d r e g i o n , the e l e c t r o n s a t the i o n i z a t i o n p o i n t e x i t w i t h unchanged energy. The second p l a t e i s u s u a l l y grounded (V„). The v o l t a g e s , V 5 and V 7 a p p l i e d on the t o p c y l i n d e r and the bottom c y l i n d e r a r e almost the same, and the v o l t a g e on the c e n t r a l c y l i n d e r i s u s u a l l y grounded. These t h r e e c y l i n d r i c a l elements are thus o p e r a t e d as a s i m p l e e i n z e l l e n s ( 2 ) , which does not change the k i n e t i c energy of 48 Fig. 4 The lens system of the PE spectrometer 49 TABLE 1 Some typical values of the voltages for the lens system  of the PE spectrometer Voltage labe l 9 Voltage value (Volts) V V v l scan V 2 V scan V V 3 scan V^  grounded Vc -5.60 Vg grounded V ? -5.60 Vg grounded a. Refer to Fig. 4. 50 the p a s s i n g e l e c t r o n s . The v o l t a g e , V e, on the bottom p l a t e i s grounded. Hence, the k i n e t i c energy of an e l e c t r o n l e a v i n g the l e n s system w i l l be c l o s e t o E { = E d - eVicaK where E<: i s the i n i t i a l energy of the e l e c t r o n , E ^ i s i t s f i n a l energy, and V s c a n. i s the s c a n n i n g v o l t a g e . Some v o l t a g e s may be o f f s e t i n d e p e n d e n t l y from the l i s t e d v a l u e s t o compensate f o r p o s i t i o n a l v a r i a t i o n s i n the l e n s elements t o p r o v i d e o p t i m a l c o u n t s and r e s o l u t i o n . The v o l t a g e s , V 5 and V 7 can be s e t t o o t h e r v a l u e s as l o n g as the two a r e c l o s e , but the l i s t e d v a l u e s (Table 1) were once the o p t i m a l ones. The v o l t a g e Vfl a f f e c t s the c o l l e c t i n g e f f i c i e n c y over the energy range, e s p e c i a l l y the i n t e n s i t y of the low k i n e t i c energy e l e c t r o n s and can t h e r e f o r e be used t o stu d y I P ' s near the l i g h t source c u t - o f f a t 21.2eV. I t has no e f f e c t on the f i n a l k i n e t i c energy of the e l e c t r o n s because i t a c c e l e r a t e s an e l e c t r o n on one s i d e but r e t a r d t h a t on the o t h e r s i d e or v i c e v e r s a . The lower bound of i t s v a l u e i s the n e g a t i v e of the pass energy, i . e . -eV„ has t o be s m a l l e r than t h e pass energy eVp^ (b) The 180° h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r : A sch e m a t i c diagram of the e l e c t r o s t a t i c a n a l y z e r i s shown i n F i g . 5. The d e s i g n has been f u l l y d i s c u s s e d i n Ref. 1. The r a d i a l p o t e n t i a l between the two h e m i s p h e r i c a l elements i s V ( r ) = A/r + B where A and B a r e c o n s t a n t s . For an e l e c t r o n w i t h k i n e t i c 52 energy e V p ^ ( v e l o c i t y v 0 ) p a s s i n g t h rough the' a n a l y z e r w i t h a s e m i c i r c u l a r t r a j e c t o r y (r=R 0) and b e i n g d e f l e c t e d by 180° upon l e a v i n g the a n a l y z e r , and s i n c e C e n t r i f u g a l f o r c e = E l e c t r i c f o r c e M v 0 2 / R 0 = eA/R 0 2 2eVpa55 = eA/R 0 A = 2R 0V / 0 d ss Hence the r e l a t i o n s h i p between the v o l t a g e drop between the two elements ( V 1 2 ) and the pass energy (eVpa» ) i s V 1 2 = V(R t) - V ( R 2 ) = Vpass (R 2/Ri - R,/R 2) The r e s o l u t i o n , AE, of the a n a l y z e r i s approx i m a t e d by (3) AE = (d/2R 0) x e V p ^ where d i s the d i a m e t e r of the e n t r a n c e and e x i t a p e r t u r e s . Hence, i f the a n a l y z e r i s o p e r a t e d a t a f i x e d pass energy as i n t h i s work, the r e s o l u t i o n w i l l be c o n s t a n t throughout the whole energy range. S i n c e h i g h count r a t e ( h i g h s e n s i t i v i t y ) i s more c r u c i a l than v e r y h i g h r e s o l u t i o n f o r the s t u d i e s d i s c r i b e d i n t h i s t h e s i s , d i s s e t t o 0.02" w i t h R 0 e q u a l t o 1.25" and Vpass about 5 V o l t s . The p r a c t i c a l r e s o l u t i o n i s about 45meV w i t h a count r a t e of 50000cps f o r the Ar 2P^ peak a t 1.2x10" 5 t o r r ( p r e s s u r e a t the i o n gauge). (c) The Helmholtz c o i l s i The H e l m h o l t z c o i l s c o n s i s t of s i x square c o i l s s u p p o r t e d by an alumimum framework. T h e i r f u n c t i o n 53 i s t o compensate f o r a l l magnetic f i e l d s . The c u r r e n t f o r each c o i l i s s u p p l i e d by a DC power s u p p l y (Lambda LH122AFM) and i s a d j u s t e d by some c o a r s e and f i n e p o t e n t i o m e t e r s . C. The l i g h t s ource u n i t An i n t e n s e uv photon f l u x may be g e n e r a t e d by a low p r e s s u r e microwave d i s c h a r g e (2450MHz) i n h e l i u m or o t h e r gases. T h i s i s powered by a M i c r o t r o n - 2 0 0 g e n e r a t o r ( E l e c t r o - M e d i c a l S u p p l i e r s ) o p e r a t i n g a t about 100 w a t t s . The v e r t i c a l c r o s s - s e c t i o n of the l i g h t s o u r c e u n i t i s shown i n F i g . 2. The d e t a i l s of t h i s u n i t have been mentioned i n Ref. 1. However, t h e r e a r e two i m p o r t a n t m o d i f i c a t i o n s ; f i r s t of a l l , the r e g i o n of d i f f e r e n t i a l pumping between the c o l l i m a t i n g c a p i l l a r y and the q u a r t z d i s c h a r g e tube has been r e c o n s t r u c t e d i n o r d e r t o house a f i l t e r h o l d e r . T h i s h o l d e r can be s l i d up and down w i t h o u t b r e a k i n g the vacuum s e a l e f f e c t e d by a V i t o n O - r i n g . Thus, a p a r t i c u l a r f i l t e r can be p o s i t i o n e d between the c a p i l l a r y and the q u a r t z tube c o n v e n i e n t l y . The p o s i t i o n of the f i l t e r h o l d e r can be m o n i t o r e d t h r o u g h the two g l a s s windows. A f u r t h e r m o d i f i c a t i o n i n v o l v e s the i n c o r p o r a t i o n of a T - j o i n t and two l e a k - c o n t r o l s ( G r a n v i l l e P h i l i p s ) such t h a t a m i x t u r e of gases can be i n p u t t o the d i s c h a r g e tube and the c o m p o s i t i o n can be changed e a s i l y w h i l s t s t i l l o p e r a t i n g the l i g h t s o u r c e . The a p p l i c a t i o n s of t h e s e m o d i f i c a t i o n s a r e d i s c u s s e d l a t e r . 54 D. The s c a n n i n g system A 10 V o l t - r a m p from the microcomputer p r o v i d e s the i n p u t t o the s c a n n i n g v o l t a g e c o n t r o l ( F i g . 6 ) . The f u n c t i o n of the c i r c u i t r y i s t o a d j u s t the s t e p s i z e of the ramp by an o p e r a t i o n a l a m p l i f i e r (op-amp) and append an o f f s e t v o l t a g e t o i t s o u t p u t . The r e s u l t a n t s c a n n i n g v o l t a g e , i s a p p l i e d t o the to p t h r e e elements of the l e n s system. The h e m i s p h e r i c a l e l e c t r o s t a t i c a n a l y z e r i s always o p e r a t e d i n a c o n s t a n t pass energy mode. Hence the i n i t i a l k i n e t i c energy (at the i o n i z a t i o n p o i n t ) of an e l e c t r o n b e i n g d e t e c t e d i s g i v e n by E = e ( V 5 c a n + V p a s 5 - V ( R 0 ) ) A l l the c o n s t a n t v o l t a g e s a p p l i e d t o the l e n s system and the a n a l y z e r a r e s u p p l i e d by b a t t e r i e s and a d j u s t e d by p o t e n t i o m e t e r s and r e s i s t o r n etworks. E. The d e t e c t i n g system Upon l e a v i n g the a n a l y z e r , e l e c t r o n s a r e a c c e l e r a t e d by +300 V o l t s a p p l i e d t o the f r o n t end of a CEM ( M u l l a r d B319AL) o p e r a t i n g i n the s a t u r a t e d mode. The h i g h v o l t a g e (about 3000 V o l t s ) a p p l i e d t o the t e r m i n a l of the CEM i s s u p p l i e d by a H e w l e t t P a c k a r d 6516A DC power s u p p l y . The p u l s e output goes v i a a p r e a m p l i f i e r t o a Harshaw NA-15 a m p l i f i e r and a NH-84A d i s c r i m i n a t o r . The t a i l o r e d p u l s e s i g n a l i s then s p l i t . One stream goes t o a r a t e m e t e r t o g i v e a f a s t r e a d - o u t . DISCRETE GAIN CONTROL Ramp frnm OAP. n f t.hp  mir.rnr.nmpntpr rnntrnl system OP-AM RAMP AMPLITUDE FINE CONTROL RAMP LEVEL OFFSET -QSranning voltage tn thP PF/PIM spectrometer Fig. 6 A block diagram of the scanning voltage control for the PE/PIM spectrometer cn 56 The o t h e r stream i s t r a n s f e r r e d t o the microcomputer f o r data a c q u i s i t i o n . The PE s p e c t r o m e t e r i s r e g u l a r l y c a l i b r a t e d w i t h a m i x t u r e of A r , N 2 and 0 2 . The s c a l e of PE s p e c t r a i s o b t a i n e d by a l i n e a r l e a s t square f i t of the I P ' s of t h e s e t h r e e m o l e c u l e s (7) w i t h the h o r i z o n t a l a x i s . 57 3.2 A d d i t i o n of a Quadrupole Mass Spectrometer t o the PE  Spectrometer A mass s p e c t r o m e t e r was added t o the PE s p e c t r o m e t e r i n o r d e r t o det e r m i n e the masses of the i o n i z e d m o l e c u l e s and fragments. T h i s a d d i t i o n a l i n f o r m a t i o n has proven t o be e x t r e m e l y u s e f u l as w i l l be shown i n P a r t I I I of t h i s t h e s i s . A q u a d r u p o l e mass s p e c t r o m e t e r was chosen f o r i t s r e l a t i v e l y low c o s t , s i m p l i c i t y of o p e r a t i o n , h i g h s e n s i t i v i t y , and c o m p a t i b l e s i z e f o r c o u p l i n g t o the PE s p e c t r o m e t e r . The absence of any s t r o n g magnetic f i e l d i s another i m p o r t a n t f e a t u r e of a quad r u p o l e mass s p e c t r o m e t e r . F u r t h e r m o r e , the d e t e c t i n g system i s s i m i l a r t o t h a t of the PE s p e c t r o m e t e r ; hence, some of the e l e c t r o n i c hardware and the c o n t r o l s o f t w a r e can be shared between the two s p e c t r o m e t e r s . A. C o n s t r u c t i o n of the quad r u p o l e mass s p e c t r o m e t e r (a) The q u a d r u p o l e r o d assembly The q u a d r u p o l e mass s p e c t r o m e t e r was b u i l t a c c o r d i n g t o the d e s i g n of the QUAD 150A R e s i d u a l Gas A n a l y z e r ( E l e c t r o n i c A s s o c i a t e s I n c . ) . The qu a d r u p o l e i s appro x i m a t e d by f o u r c y l i n d r i c a l b r a s s r o d s . The c r o s s s e c t i o n of t h e r o d assembly p e r p e n d i c u l a r t o the a x i a l a x i s i s shown i n F i g . 7 and the c r o s s s e c t i o n a l o n g the a x i a l a x i s i s shown i n F i g . 8. 58 Seal e Fig. 7 The rod assembly of the quadrupole mass spectrometer  (cross section perpendicular to the axial axis) 59 Wp Fleet, rode 1 *fff\ n—v/',n Ton entrance Brass rod Ion exit •cxu Seal e A I k Fig. 8 ThP rnd asspmhly and the detector of thp quadrupole mass spectrometer (cross section along the axial axis of the rods) 60 (b) The i o n i z a t i o n u n i t The sample gas may be i o n i z e d near the e n t r a n c e of the quad r u p o l e e i t h e r by e l e c t r o n or photon impact. ( i ) E l e c t r o n impact i o n i z a t i o n : M o l e c u l e s a r e i o n i z e d by an i o n i z a t i o n arrangement as shown i n F i g . 9. Thermal e l e c t r o n s a r e g e n e r a t e d from a heated t u n g s t e n f i l a m e n t . N e g a t i v e v o l t a g e , t y p i c a l l y -70 V o l t s w i t h r e s p e c t t o F i s a p p l i e d t o D and d 3 i n o r d e r t o i n i t i a l i z e the k i n e t i c energy of the e l e c t r o n s p a s s i n g t h r o u g h the s l i t of the Faraday cage. The t a r g e t m o l e c u l e s a r e bombarded by th e s e e l e c t r o n s i n s i d e the cage. The i o n s a r e a c c e l e r a t e d by the p o s i t i v e v o l t a g e on the cage (0-30 V o l t s ) , f o c u s e d by the f o c u s i n g p l a t e C (0 t o -100 V o l t s ) , and they then e n t e r the qua d r u p o l e t h r o u g h the e n t r a n c e a p e r t u r e B. The e x c e s s e l e c t r o n s e m i t t e d from the f i l a m e n t a r e c o l l e c t e d by the e l e c t r o n e x t r a c t o r E o p e r a t e d a t a p o s i t i v e v o l t a g e (0-30 V o l t s ) . T h i s method of i o n i z a t i o n i s the most common method used i n mass s p e c t r o m e t r y , but has l i m i t a t i o n s here due t o e x c e s s i v e f r a g m e n t a t i o n ( s i n c e the e l e c t r o n e n e r g i e s a r e f a i r l y h i g h , up t o 70eV), and a l s o t h e r m a l d e c o m p o s i t i o n of the t a r g e t m o l e c u l e s on the hot f i l a m e n t . D i r e c t p h o t o i o n i z a t i o n w i t h the l i g h t s o u r c e as d e s c r i b e d below i s p r e f e r r e d . ( i i ) P h o t o i o n i z a t i o n : In t h i s c a s e , the e l e c t r o n impact i o n i z a t i o n arrangement i s r e p l a c e d w i t h the chamber shown i n F i g . 10. M o l e c u l e s a r e i o n i z e d by the uv l i g h t from the l i g h t s o urce i n s i d e the c y l i n d r i c a l i o n i z a t i o n chamber e n c l o s e d by two c i r c u l a r p l a t e s D and F,. and a c y l i n d r i c a l cup E. Ions 61 A. Entrance l i d B. Entrance aperature C. Focusing plate D. Filament holder d.| filament d ? one electrode for the filament another electrode E. Electron extractor F. Faraday cage G. Sample entrance Fig. 9 The electron impact ionization kit for the quadrupole mass spectrometer 62 inns pump out Tight source sample in A. The entrance l i d of the quadrupole rod assembly B. Entrance aperture C. Focusing plate D. Ion exit plate E. Collimating cup F. Ion accelerator Fig. 1 0 The photoionization chamber for the qaadrupole mass  spectrometer 63 are c o l l i m a t e d and e x p e l l e d from the chamber by the p o s i t i v e v o l t a g e s " on E and F (about 30-40 V o l t s ) . The i o n e x i t p l a t e D i s u s u a l l y grounded. Ions a r e f u r t h e r f o c u s e d by a p o s i t i v e v o l t a g e (0-30 V o l t s ) on the f o c u s i n g p l a t e C and move i n t o the quadr u p o l e t h r o u g h the e n t r a n c e a p e r t u r e B. The b a s i c i o n i z a t i o n a s s e m b l i e s a r e the same as tho s e of the PE s p e c t r o m e t e r , i . e . both s p e c t r o m e t e r s share the same i o n i z a t i o n r e g i o n . (c) E l e c t r o n i c c o n t r o l of the qu a d r u p o l e mass s p e c t r o m e t e r The q u a d r u p o l e mass s p e c t r o m e t e r i s c o n t r o l l e d by a QUAD 150A R e s i d u a l Gas A n a l y z e r C o n t r o l U n i t ( E l e c t r o n i c A s s o c i a t e s INC.). A b l o c k diagram of the u n i t i s shown i n F i g . 11. The sweep g e n e r a t o r o u t p u t s a 0-10 V o l t ramp which, a f t e r a m p l i f i c a t i o n by an op-amp, d r i v e s the RF and DC g e n e r a t o r s . The RF g e n e r a t o r s u p p l i e s a 0-2400 V o l t peak t o peak ramp a t 3.3 MHz w i t h a 150 amu c o i l . The ramp of the DC g e n e r a t o r ranges from +180 t o -180 V o l t s . In t h i s o p e r a t i n g c o n d i t i o n , the mass range scanned by the s p e c t r o m e t e r i s from 0-150 m/e. However, a 300 m/e c o i l was i n s t a l l e d which b r i n g s the RF fr e q u e n c y down t o about 2.4 MHz. By eqn. 2.69, the mass range was i n c r e a s e d t o 0-300 m/e. U s u a l l y , the mass s p e c t r o m e t e r i s o p e r a t e d i n a user programmed mode such t h a t the i n t e r n a l sweep g e n e r a t o r i s bypassed. The ramp i n p u t t o the op-amp t o d r i v e the RF and DC g e n e r a t o r s i s s u p p l i e d by the user d i r e c t l y . The sou r c e of the ramp i n t h i s case i s from the s c a n n i n g v o l t a g e c o n t r o l u n i t as W E T GENERATOR Scanning voltage from the scanning voltage control OP ,><\MP MODULATOR DRIVER RF DETECTOR RF MODULATOR CENTER MASS! CONTROL POWER SUPPLY (high voltage RF GENERATOR L VQ + V^oswt DC GENERATOR to the rods (VQ + V^oswt) RESOLUTION CONTROL Fig. 11 A block diagram of the electronic control for the guadrnpnlp mass spectrometer •4^  65 d e s c r i b e d i n s e c t i o n 3.1D. (d) D e t e c t i n g system The i o n d e t e c t o r i s a CEM which a c c e p t s i o n s which have s u c c e s s f u l l y t r a v e r s e d t h r o u g h the qu a d r u p o l e r o d assembly. I t s c o n f i g u r a t i o n and o p e r a t i o n a re the same as the d e t e c t o r of the PE s p e c t r o m e t e r , except t h a t the a c c e l e r a t i n g v o l t a g e a t the e n t r a n c e of the CEM i s -300 V o l t s and the h i g h v o l t a g e a p p l i e d a t i t s t e r m i n a l i s 2000-2500 V o l t s . I t s h o u l d be remembered t h a t the CEM can d i s c r i m i n a t e a g a i n s t i o n s of d i f f e r e n t masses and f o r q u a n t i t a t i v e work a Faraday c o l l e c t o r i s p r e f e r r e d . B. C o u p l i n g of the quad r u p o l e mass s p e c t r o m e t e r t o the PE s p e c t -r o m e t e r The t o p l i d of the PE s p e c t r o m e t e r as shown i n F i g . 1 i s r e p l a c e d by the qu a d r u p o l e mass s p e c t r o m e t e r . U s u a l l y , the mass s p e c t r o m e t e r i s o p e r a t e d i n the p h o t o i o n i z a t i o n mode and i t sha r e s the i o n i z a t i o n chamber e n c l o s e d by the top t h r e e elements of the l e n s system of the PE s p e c t r o m e t e r as shown i n F i g . 12. However, i t i s easy t o reassemble the e l e c t r o n impact i o n i z a t i o n k i t t o o p e r a t e the mass s p e c t r o m e t e r i n the e l e c t r o n impact i o n i z a t i o n mode. The vacuum c o n d i t i o n of the mass s p e c t r o m e t e r i s m a i n t a i n e d by pumping the system t h r o u g h the p o i n t of c o n n e c t i o n t o the PE 66 Fig. 12 The construction of the PE/PIM spectrometer 67 s p e c t r o m e t e r . No d i f f e r e n t i a l pumping i s a p p l i e d d i r e c t l y t o the r o d assembly or the d e t e c t o r chamber. T h i s has n o t , as y e t , been found t o be n e c e s s a r y , p a r t i c u l a r l y s i n c e the h i g h v o l t a g e on the CEM i s lower than t h a t used f o r c o u n t i n g e l e c t r o n s . The l i g h t source f o r p h o t o i o n i z a t i o n i s a l s o shared between the two s p e c t r o m e t e r s . As f a r as the mass s p e c t r o m e t e r i s concerned, i t i s v e r y d e s i r a b l e t o i o n i z e a m o l e c u l e w i t h m i n i m a l photon energy i n o r d e r t o reduce i o n f r a g m e n t a t i o n . T h i s has been r e a l i z e d by s p l i t t i n g the gas i n l e t of the d i s c h a r g e tube i n t o two i n l e t s each l i n k e d t o a G r a n v i l l e P h i l l i p s l e a k c o n t r o l . One l e a k c o n t r o l i s d e d i c a t e d t o the fl o w of h e l i u m ( t y p i c a l l y used t o produce Hel r a d i a t i o n f o r PES s t u d i e s ) . The o t h e r may be used t o i n p u t another gas, t y p i c a l l y hydrogen, i n t o the d i s c h a r g e tube. T h i s c o n f i g u r a t i o n p r o v i d e s f a s t s w i t c h i n g between two photon e n e r g i e s w i t h o u t the n e c e s s i t y of t u r n i n g o f f the l i g h t s o u r c e . A range of p h o t o i o n i z a t i o n l i g h t s o u r c e s a r e a v a i l a b l e which can be t a i l o r e d t o s u i t the I P ' s and f r a g m e n t a t i o n p a t t e r n s of the m o l e c u l e s under i n v e s t i g a t i o n . Some of these are shown i n T a b l e 2. The hydrogen Lyman o r a d i a t i o n produced by the microwave d i s c h a r g e of a hydrogen-helium m i x t u r e (25% hydrogen) i s a u s e f u l r e l a t i v e l y low energy photon so u r c e ( p l 6 0 of Ref. 4 ) . The t r a c e of hydrogen Lyman p and r r a d i a t i o n s a re sometimes v e r y u s e f u l t o i o n i z e m o l e c u l e s w i t h h i g h e r f i r s t I P ' s . However, they can be e l i m i n a t e d by i n s e r t i n g a c r y s t a l ( L i F ) between the q u a r t z d i s c h a r g e tube and the c o l l i m a t i n g c a p i l l a r y as a f i l t e r . The t r a n s m i t t a n c e of L i F as a f u n c t i o n 68 TABLE 2 Energies of some l ight sources for UPS and PIMS Radiation Energy (eV)3 Wavelength (I) Hell 40.81 303.78 Hel 21.22 584.33 Nel 16.85(100) 735.89 16.67(15) 743.72 Arl 11.62(100) 1066.66 11.83(50) 1048.22 HL 10.20(100) 1215.67 HL6 12.09(10) 1025.72 HL^ 12.75(1) 972.54 a. Numbers in parenthesis are the relative intensi t ies . b. The values in this table are taken from Ref. 6. 69 of wavelength and temperature has been d i s c u s s e d by L a u f e r et a l . ( 5 ) ; the t r a n s m i t t a n c e c u r v e a t 26°C i s shown i n F i g . 13, w i t h the a d d i t i o n of the l i n e p o s i t i o n s of the hydrogen Lyman o, I and r r a d i a t i o n . The d e t a i l s of the f i l t e r h o l d e r a r e shown i n F i g . 14. I t can be s l i d up and down w i t h o u t b r e a k i n g the vacuum s e a l e f f e c t e d by a V i t o n O - r i n g around the c y l i n d r i c a l stem. In normal o p e r a t i o n , the f i l t e r h o l d e r i s a d j u s t e d t o a p o s i t i o n such t h a t a h o l e i s p l a c e d i n the l i g h t p a t h , and the PE spectrum i s o b t a i n e d w i t h the u s u a l Hel l i g h t s o u r c e . A l i s t of s u i t a b l e f i l t e r s f o r the UV r e g i o n i s shown i n T a b l e 3 (p181 of Ref. 4 ) . At p r e s e n t the two s p e c t r o m e t e r s a r e not run i n c o i n c i d e n c e . One s p e c t r o m e t e r scans a f t e r the o p e r a t i o n of the o t h e r , but the s w i t c h i n g time i s l e s s t h a n a minute, and so the two t i m e - a v e r a g e d s p e c t r a s h o u l d c o r r e l a t e t o the same e x p e r i m e n t a l c o n d i t i o n s and t h e r e f o r e the same s p e c i e s . C. Performance of the qu a d r u p o l e mass s p e c t r o m e t e r The q u a d r u p o l e mass s p e c t r o m e t e r always g i v e s a h i g h count r a t e ( e.g. 50000 cps) w i t h good s i g n a l t o n o i s e and r e a s o n a b l e r e s o l u t i o n (2 amu). S i n c e the qu a d r u p o l e mass s p e c t r o m e t e r u s u a l l y o p e r a t e s i n the p h o t o i o n i z a t i o n mode i n c o n j u n c t i o n w i t h the PE s p e c t r o m e t e r , the f o l l o w i n g d i s c u s s i o n on i t s performance w i l l c o n c e n t r a t e on t h i s o p e r a t i n g mode. 70 71 1" Seal e pum p out The construction of the f i l t e r holder TABLE 3 The transmittance cut -of f of some uv f i l t e r s F i l ter cut -off position (eV) (A) Li F 11.92 1040 MgF2 11.07 1120 CaF2 10.16 1220 SrF 2 9.69 1280 BaF2 9.25 1340 a. The values in this table are taken from Ref. 4, pi80 73 (a) G e n e r a l performance: A t y p i c a l Hel p h o t o i o n i z a t i o n mass (PIM) spectrum of CC1<, a t 0.6 x 10" 5 t o r r i s shown i n F i g . 15. The peak a t 47 amu has a count r a t e of about 5000 c p s ; background n o i s e i s below 50 c p s , the r e s o l u t i o n i s b e t t e r than 2 amu and i n t h i s case i s s u f f i c i e n t t o d i s t i n g u i s h the c h l o r i n e i s o t o p e s ( 3 5 C 1 , 3 7 C 1 ) . The mass s p e c t r o m e t e r i s always o p e r a t e d a t h i g h e r s e n s i t i v i t y (at the expense of r e s o l u t i o n ) i n o r d e r t o o b t a i n the mass spectrum as q u i c k l y as p o s s i b l e . (b) Photon energy e f f e c t t The degree of f r a g m e n t a t i o n tends t o d e c r e a s e w i t h lower photon energy as shown i n F i g . 16. F i g . 16a i s the mass spectrum of CH 3I i o n i z e d by H e l . When a t r a c e of hydrogen i s mixed w i t h the h e l i u m i n the d i s c h a r g e t u b e , the r e l a t i v e i n t e n s i t y of the p a r e n t peak i n c r e a s e s a b r u p t l y ( F i g . 16b). With a m i x t u r e of 30% hydrogen and 70% h e l i u m the p a r e n t peak becomes dominant w i t h o u t any s i g n i f i c a n t amount of the fragment I + , as shown i n F i g . 16c. T h i s i s an i n s t a n c e where the p a r e n t peak can u s u a l l y be i d e n t i f i e d , which i s of the g r e a t e s t i m p o r t a n c e . The hydrogen was s u p p l i e d by Union C a r b i d e w i t h o u t f u r t h e r p u r i f i c a t i o n . Under p r e s e n t o p e r a t i n g c o n d i t i o n s , the hydrogen Lyman a e m i s s i o n l i n e (l0.20eV) i s c o n t a m i n a t e d by Lyman p (l2.09eV) and t r a c e of Lyman r l i n e s (12.75eV). Hence, compounds w i t h the f i r s t IP l e s s than l2.7eV (HLr = l2.75eV) Relative Intensity CC1 37 f j 20 40 60 CC1. CC1 3( 3 5C1)  2( 3 5 C1)+ 3 7 Cl 3 5C1+2( 3 7C1) 2( 3 5C1) 3( 3 7C1) It 3 5 n + 37r.i 2( 3 7 cn 80 100 120 amu Fig. 15 The Hel mass spectrum of CCl^ 75 Relative Intensity CH. u a. (pure He) b. (He + trace of H2) c. (70%He + 30% 30%H2) 50 100 150 amu Fig. 16 The mass spectra of CH 3I, ionized by the radiation  from the discharge of a. He, b. He with a trace  of H 2 , and c. 70%He with 30%H2 76 can be d e t e c t e d w i t h t h i s l i g h t s o u r c e . F i l t e r s may be used t o cut o f f the HLf and HLr c o n t a m i n a t i o n and g i v e pure HLc. F i g . 17 shows the HLopr PIM spectrum of an eq u a l volume m i x t u r e of t o l u e n e ( f i r s t IP a t 8 . 7 l e V ) , CH 3OH ( f i r s t I P a t l0.95eV) and CH 3CN ( f i r s t I P a t 12.20eV). The mass spectrum of each i n d i v i d u a l s p e c i e s g i v e s a s i n g l e p a r e n t peak o n l y . The r e l a t i v e i n t e n s i t y of the peaks i n F i g . 17a w i l l be a f f e c t e d by the vapor p r e s s u r e of the compounds which a r e 27 t o r r f o r t o l u e n e , 114 t o r r f o r CH 3OH and 88 t o r r f o r CH 3CN, a t 298°C. One must a l s o c o n s i d e r the d i s c r i m i n a t i o n i n the d e t e c t o r and t h e i r d i f f e r e n t p h o t o i o n i z a t i o n c r o s s s e c t i o n . By f i l t e r i n g the l i g h t s o u r c e t h r o u g h a p i e c e of L i F c r y s t a l w i t h a t h i c k n e s s of about 1mm, no CH 3CN* and o n l y a t r a c e of CH 3OH + shows up i n the HLo PIM spectrum of the m i x t u r e ( F i g . 17). (c) P r e s s u r e e f f e c t : The b e s t r e s u l t s a r e o b t a i n e d a t p r e s s u r e s below 1 x 10" 5 t o r r . F i g . 18 shows the HLapr PIM s p e c t r a of bromobenzene a t d i f f e r e n t p r e s s u r e s . The degree of f r a g m e n t a t i o n i n c r e a s e s s l i g h t l y , but the count r a t e d e c r e a s e s , w i t h i n c r e a s i n g p r e s s u r e above 1 x 10" 5 t o r r . T h i s o p t i m a l p r e s s u r e range i s q u i t e c o m p a t i b l e w i t h the o p e r a t i n g c o n d i t i o n of the PE sp e c t r o m e t e r and so a mass spectrum of a s p e c i e s can be o b t a i n e d under e x a c t l y t he same c o n d i t i o n as the PE spectrum, or v i c e v e r s a . T h i s i s p a r t i c u l a r l y i m p o r t a n t f o r the i d e n t i f i c a t i o n of the type s of s p e c i e s under study h e r e . 77 R p l a t i v p I n t e n s i t y amu Fig. 17 The HL „ and HL (HL a f i l tered with LiF) mass a CXpY n r i n v — spectra of a mixture of CH-^ OH, ChUCN and toluene Relative  Intensity C g H 5«* + P=0.6xl0"5 V - . .. & 5 .J ,P=1.2xlO"5 V A . ~> P=2.2xl0~5 j P=3.2xlO - 5 1 I . . A J i . i 200 amu Fig . 18 Pressure effects on the degree of fragmentation and the relative count rate of the HL mass  spectrum of bromobenzene 79 3.3 Hardware f o r computer c o n t r o l of the PE/PIM s p e c t r o m e t e r The PE s p e c t r o m e t e r and the mass s p e c t r o m e t e r d e s c r i b e d above are c o n t r o l l e d by a microcomputer (LSI 11/03). The s t r u c t u r e of t h i s microcomputer c o n t r o l system i s shown i n F i g . 19. The 1 6 b i t g e n e r a l purpose c e n t r a l p r o c e s s o r u n i t (CPU), DEC'S LSI 11/03, s u p e r v i s e s the 64 Kbytes main memory and o t h e r p e r i p h e r a l s t h r o u g h a s e t of communication l i n e s , the UNIBUS. A s c a n n i n g v o l t a g e i s s e t and changed a c c o r d i n g t o the d a t a a c q u i s i t i o n program and output e i t h e r t o the PE s p e c t r o m e t e r or the mass s p e c t r o m e t e r ( c o n t r o l l e d by an e x t e r n a l s w i t c h ) . T h i s v o l t a g e output i s implemented by one c h a n n e l of a 1 2 b i t 4-channel DAC (DT2766, Data T r a n s l a t i o n ) . The +10 t o -10 V o l t DAC o u t p u t i s f u r t h e r a d j u s t e d and o f f s e t t o a s u i t a b l e range of v o l t a g e s by an op-amp, v a r i o u s p o t e n t i o m e t e r s , r e s i s t o r s and a b a t t e r y . The s i g n a l s from the s p e c t r o m e t e r s a r e p u l s e s which a r e a m p l i f i e d and t a i l o r e d by a p r e a m p l i f i e r , an a m p l i f i e r and a d i s c r i m i n a t o r and then i n p u t t o the p u l s e c o u n t e r of the computer c o n t r o l system. A spectrum i s o b t a i n e d ( F i g . 24) t h r o u g h the c o o p e r a t i o n of the s c a n n i n g v o l t a g e output and p u l s e c o u n t i n g p r o c e s s e s , and the t i m i n g p r o c e s s r e a l i z e d by a r e a l - t i m e c l o c k (DT2769, Data T r a n s l a t i o n ) . In the p r e s e n t system, a h i g h r e s o l u t i o n spectrum can be r e c o r d e d by u s i n g up t o 4K p o i n t s . A spectrum i s s t o r e d i n the main memory w h i l e s c a n n i n g and i s then t r a n s f e r e d to a f l o p p y d i s k u n i t (DSD440, Data Systems Design) a f t e r the s c a n n i n g has been completed. I t i s d i s p l a y e d 80 Video Termin al iConsole Computer System Level J > \ 1 \ > / 1 > UNIBUS 4 Pul se ADC Interface Counter Level X-Y Plotter Osc i l lo -scope Spectrum Display PE/PIM Spectro-meter Application Level Fig. 19 The structure of the microcomputer control system 81 number of pulses count wi th a pulse counter r * t i by a real-time clock 1 5 6 8 4096 .scanning voltage number of points • scan with a DAC Fig. 20 The scanning process of a digit ized spectrum 82 on an o s c i l l o s c o p e by u s i n g two c h a n n e l s of the DAC as the X and Y c o o r d i n a t e s . A p l o t of the spectrum i s f a c i l i t a t e d by a X-Y p l o t t e r and the same DAC d e v i c e . The c o n t r o l system i s m o n i t o r e d by a v i d e o t e r m i n a l c o n s o l e (VT100, DEC). A hard copy of any d a t a or s o f t w a r e may be output through a t e l e t y p e ( T e l e t y p e C o r p o r a t i o n ) . 83 References (Chapter 3) 1. S.T. Lee, Ph.D. t h e s i s , UBC, 1974. 2. E. H a r t i n g and F.H. Read, ' E l e c t r o s t a t i c l e n s e s ' , E l s e v i e r , Amsterdam, 1976. 3. C.E. R u y a t t and J.A. Simpson, Rev. S c i . I n s t . , 38(1967)103. 4. J.A.R. Samson, 'Techniques of vacuum u l t r a v i o l e t s p e c t r o -scopy', W i l e y , New York, 1967. 5. A.H. L a u f e r , J.A. P i r o g and J.R. McNesby, J . Opt. Soc. Am., 55(1965)64. 6. J.W. R a b a l a i s , ' P r i n c i p l e s of u l t r a v i o l e t p h o t o e l e c t r o n s p e c t r o s c o p y ' , John W i l e y and Sons, New York, (1977)22. 7. D.W. T u r n e r , C. Baker, A.D. Baker and C R . B r u n d l e , ' M o l e c u l a r p h o t o e l e c t r o n s p e c t r o s c o p y ' , W i l e y , London, 1 970. 84 Chapter 4 Software Development 4.1 I n t r o d u c t i o n The i n t e r p r e t a t i o n of a PE spectrum, as mentioned i n c h a p t e r 2, always r e l i e s on some quantum m e c h a n i c a l methods which a r e not o n l y a b l e t o a s s i g n i o n i z a t i o n p r o c e s s e s t o PE peaks but a l s o c o r r e l a t e p a r t of the spectrum t o the n a t u r e of the c o r r e s p o n d i n g c a t i o n , and the whole spectrum t o the m o l e c u l a r p r o p e r t i e s of the p a r e n t s p e c i e s . Hence, g e o m e t r i c and e l e c t r o n i c s t r u c t u r e s , and r e l a t i v e s t a b i l i t y , e t c . , can be deduced. The most w i d e l y used quantum m e c h a n i c a l t r e a t m e n t i s the LCAO ( L i n e a r Combination of Atomic O r b i t a l s ) approach t o the HF-SCF method, which i s a l s o r e f e r r e d t o as the Roothaan-HF method ( 1 , 2 ) . D i r e c t i m p l e m e n t a t i o n of t h i s i d e a l e a d s t o some ab i n i t i o computer programs. A f t e r c h o o s i n g a b a s i s s e t of AO's, a l l the i n t e g r a l s i n the Roothaan-HF f o r m u l a t i o n a r e e v a l u a t e d a n a l y t i c a l l y and the MO s e t i s o b t a i n e d by the SCF t r e a t m e n t . In p r a c t i c e , the AO b a s i s s e t cannot be a complete s e t and i t s s i z e always i n d i c a t e s the q u a l i t i e s as w e l l as the c o s t of the ab i n i t i o c a l c u l a t i o n s . However, even w i t h a ve r y s m a l l b a s i s s e t , the c o s t of ab i n i t i o c a l c u l a t i o n s f o r a m a n y - e l e c t r o n m o l e c u l e i s s t i l l always v e r y h i g h . Hence, i n the s e m i - e m p i r i c a l SCF approach, the computing-time-consuming i n t e g r a l s of the Roothaan-HF method a r e not c a l c u l a t e d p r e c i s e l y . C e r t a i n i n t e g r a l s a r e r e l a t e d t o some s p e c t r o s c o p i c d a t a , e s t i m a t e d by a few s i m p l e p a r a m e t e r i z e d e q u a t i o n s , or even 85 j u s t s e t t o z e r o e m p i r i c a l l y . The o b v i o u s advantages are low c o s t , and a p p l i c a b i l i t y t o r a t h e r l a r g e m o l e c u l e s . However, due t o the s u b j e c t i v i t y i n s e t t i n g a p p r o x i m a t i o n s and c h o o s i n g t y p e s of e m p i r i c a l d a t a i n the p a r a m e t e r i z a t i o n p r o c e d u r e s , and the l i m i t e d amounts of the s e d a t a f o r the f i t t i n g p u rpose, a s e m i - e m p i r i c a l program may be v e r y good i n some a p p l i c a t i o n s but not so good i n o t h e r s . In s h o r t , both ab i n i t i o and s e m i - e m p i r i c a l programs have t h e i r own c h a r a c t e r i s t i c a p p l i c a b i 1 i t i e s . ' A c c o r d i n g l y , a l i b r a r y of PES r e l a t e d computer programs at d i f f e r e n t ' e m p i r i c a l ' l e v e l s has been e s t a b l i s h e d . The program l i b r a r y c o n t a i n s some w i d e l y used ab i n i t i o programs, such as GAUSSIAN 70 ( 3 ) , GAUSSIAN 76 (4) and HONDO 5 ( 5 ) ; s e m i - e m p i r i c a l programs such as CNDO/2 (INDO i n c l u d e d ) ( 6 ) , MINDO/3 ( 7 ) , MNDO (8) and HAM/3 ( 9 ) ; the RSPT program (10) t o c o r r e c t Koopmans' theorem; a r e c e n t l y m o d i f i e d HAM/3 program t o do v a l e n c e - e l e c t r o n shake-up c a l c u l a t i o n s ( 1 1 ) ; and some o t h e r o t h e r programs such as GEOMIN (12) t o perfo r m f u l l geometry o p t i m i z a t i o n w i t h the CNDO/INDO a p p r o a c h , and BOYLOC (13) t o i n c l u d e MO l o c a l i z a t i o n , e t c . The most f r e q u e n t l y used GAUSSIAN 70 and 76, CNDO/2 and INDO, MINDO/3, HAM/3, and MNDO programs, and the RSPT programs are d e s c r i b e d b r i e f l y i n s e c t i o n 4.2, w i t h a performance and c o s t comparison of the GAUSSIAN 70, CNDO/2, MINDO/3, HAM/3, and MNDO programs. B e s i d e s the use of a main-frame t o do l a r g e s c a l e c o m p u t a t i o n , a p p l i c a t i o n s of m i c r o - or minicomputer i n 86 s p e c t r o m e t e r c o n t r o l , d ata a c q u i s i t i o n , d a t a s t o r a g e and s p e c t r a l d a t a m a n i p u l a t i o n a r e a l s o r a p i d l y expanding i n PES. T h i s i d e a has been r e a l i z e d by the hardware i n t e r f a c e of a LSI 11/03 microcomputer t o the PES/PIMS system as mentioned i n c h a p t e r 3 and the development of a s m a l l r e a l - t i m e o p e r a t i n g system. S e c t i o n 4.3 d e s c r i b e s the aim, the d e s i g n and the i m p l e m e n t a t i o n of t h i s system program. The d e t a i l e d codes of the program appear i n the appendix of t h i s t h e s i s . 4.2 The l i b r a r y of computer programs f o r PES 4.2A The ab i n i t i o GAUSSIAN 70 and 76 programs The GAUSSIAN 70 program (3) i s an ab i n i t i o approach t o the Roothaan-HF method. S i n c e m u l t i - c e n t e r i n t e g r a t i o n i n v o l v i n g G a u s s i a n type f u n c t i o n s (GTF's) i s much e a s i e r than t h a t i n v o l v i n g S l a t e r f u n c t i o n s , a S l a t e r type o r b i t a l (STO) i s s i m u l a t e d by s e v e r a l GTF's i n t h i s program (p.56-66 of R e f . 1 4 ) . Analogous t o the m i n i m a l b a s i s s e t of STO (each AO f o r the s h e l l a t l e a s t p a r t l y o c c u p i e d i s r e p r e s e n t e d by a STO), the m i n i m a l b a s i s s e t of GTF i s c a l l e d STO-NG, where N = 2 , 3, , 6 i n t h i s program (each AO of the s h e l l a t l e a s t p a r t l y o c c u p i e d i s r e p r e s e n t e d by a STO which i s a g a i n l e a s t - s q u a r e f i t t e d by N GTF's) ( 1 5 ) . However, the extended b a s i s s e t of GTF, N-31G, i s s l i g h t l y d i f f e r e n t from the extended b a s i s s e t of STO (each v a l e n c e AO i s r e p r e s e n t e d by more than one STO's. For d o u b l e - z e t a b a s i s s e t , DZ-STO, each AO i s e x p r e s s e d i n terms of 87 two STO's, i . e . two-S 's as the e x p o n e n t ) . In the GAUSSIAN 70 program, AO's of an atom a r e s p l i t i n t o v a l e n c e s h e l l and i n n e r s h e l l AO's. Each i n n e r s h e l l AO i s w r i t t e n as a sum of N GTF's, w h i l e a v a l e n c e s h e l l AO (e.g. 2s, 2p on f i r s t row atoms) i s d e s c r i b e d by i t s i n n e r and o u t e r p a r t s . The i n n e r p a r t i s e x p r e s s e d by 3 GTF's and the o u t e r p a r t i s e x p r e s s e d by one GTF. A c c o r d i n g l y , t h i s b a s i s s e t i s a l s o c a l l e d a v a l e n c e extended b a s i s s e t ( 1 6 ) . The r e s t r i c t i o n s of the GAUSSIAN 70 programs a r e : (1) maximum number of atoms i s 35; (2) maximum number of AO's i s 70; (3) t y p e s of AO's a r e up t o 3s and 3p o n l y ; (4) maximum number of GTF's i s 240; (5) N = 4 f o r N-31G. The program c a l c u l a t e s t o t a l energy, e i g e n v e c t o r s and e i g e n v a l u e s f o r MO's, M u l l i k e n p o p u l a t i o n , g r o s s c h a r g e s on atoms and d i p o l e moment, e t c . There a r e a l s o i n t e r n a l geometry o p t i m i z a t i o n and p o t e n t i a l s u r f a c e s c a n n i n g r o u t i n e s i n the program. The BOYLOC program (13) has been appended t o t h i s program and p r o v i d e s MO l o c a l i z a t i o n r e s u l t s . Another m o d i f i c a t i o n i s an o p t i o n t o i n p u t the maximum number of SCF i t e r a t i o n s and the co n v e r g e n t l i m i t i n s t e a d of u s i n g the i n t e r n a l c o n s t a n t s . T h i s m o d i f i c a t i o n i s u s e f u l where i n case d i f f i c u l t i e s i n SCF convergence o c c u r . The GAUSSIAN 76 program (4) i s an e x t e n s i o n of the GAUSSIAN 70 program. P o l a r i z a t i o n f u n c t i o n s , f u n c t i o n s 88 c o r r e s p o n d i n g t o AO's w i t h h i g h e r a z i m u t h a l quantum numbers than those c o r r e s p o n d i n g t o AO's o c c u p i e d i n the ground s t a t e (e.g. f o r hydrogen, p, d, and f o r oxygen, d, f , . . . ) , a r e a v a i l a b l e i n t h i s new v e r s i o n . Hence, f o r STO-NG*, 5 d-GTF's ar e added t o the STO-NG b a s i s s e t of second row atoms; f o r N-31G*, 6 d-GTF's are added t o the N-31G b a s i s s e t of f i r s t row and second row atoms; f o r N-31G**, 3 p-GTF's a r e added t o the N-31G* f o r each hydrogen atom ( 4 ) . The b a s i s s e t e f f e c t , u s i n g H 20 as an example, on the a c c u r a c y and e f f i c i e n c y of the GAUSSIAN 76 program i s summarized i n T a b l e 1.' The t o t a l e n e r g i e s o b t a i n e d by a m i n i m a l STO b a s i s s e t ( 1 7 ) , a DZ-STO b a s i s s e t ( 1 8 ) , and an e s t i m a t i o n of the HF l i m i t ( 1 9 ) a r e a l s o i n c l u d e d , t o g e t h e r w i t h the e x p e r i m e n t a l d i p o l e moment (20) and I P ' s . There are a p p a r e n t l y g r e a t improvements from STO-2G t o STO-3G, and from STO-NG t o 4-31G. Hence, STO-3G and 4-31G a r e recommended f o r most PES s t u d i e s , b e a r i n g i n mind t h a t the c o s t of c o m p u t a t i o n i n c r e a s e s w i t h the 4th o r d e r of the t o t a l number of b a s i s f u n c t i o n s . The l a r g e s t m o l e c u l e s t u d i e d i n t h i s work i s the complex, ( C H 3 ) 2 0 - B F 3 a t 4-31G b a s i s . The c o s t of t h i s 7 5 - b a s i s - f u n c t i o n system i s about 3000sec of computing time w i t h an AMDAHL V6 / I I computer (about $1000 computer d o l l a r s i n c l u d i n g the memory u s a g e ) . The e f f i c i e n c y of the GAUSSIAN 76 i s s i m i l a r t o t h a t of the GAUSSIAN 70 program, except more memory usage i s i n v o l v e d i n the former program. About 25% of the c o s t i s saved by u s i n g the GAUSSIAN 70 program when i t i s a b l e t c t a c k l e the same problem s o l v e d by the GAUSSIAN 76 program. TABLE 1 The basis set effect on the calculations of water Basis set a--Total energy (au) Dipole moment (debye) l b l 1 IP's (eV) 3 a l l b 2 No. of basis functions No. of GTF's CPU ST02G 72.739014 1.47 9.63 11.49 16.34 7 14 1.3 ST03G 74, .963123 1;72 10. 64 12.33 16.79 7 21 1.6 ST04G 75, .496831 1.76 10. 77 12.46 16.85 7 28 2.0 ST05G 75, .636651 1.76 10. 81 12.49 16.88 7 35 2.8 ST06G 75, .678850 1.76 10. 81 12.50 16.88 7 42 4.1 STO b minimal 75 .7055 4-31G 75 .907359 2.61 13. 59 15.19 19.23 13 28 3.5 5-31G 75 .968261 2.63 13. 63 15.24 19.29 13 29 3.7 6-31G 75 .983960 2.63 13. 64 15.25 19.30 13 30 3.9 4-31G* 75 .938776 2.20 13. 49 15.46 19.13 19 34 9.9 4-31G** 75 .951890 2.16 13. 46 15.39 19.04 25 40 22. 5-31G** 76 .008486 2.18 13. 51 15.46 19.10 25 41 23. 6-31G** 76 .023095 2.19 13. ,52 15.47 19.12 25 42 24. DZ-STO0 76 .0053 H F - l i m i t d 76 .0675 Exptl 1.85e 12, ,6 14.7 18.5 a. By GAUSSIAN 76 except as s p e c i f i e d . b. Ref. 17. c. Ref. 18. d. Ref. 19. e. Ref. 20. 90 The r e s t r i c t i o n s of the GAUSSIAN 76 program a r e : (1) maximum number of atoms i s 35; (2) maximum number of AO's i s 80; (3) t y p e s of AO's are up t o 3d; (4) maximum number of GTF's i s 240; (5) N = 4, 5, 6 f o r N-31G. 4.2B S e m i - e m p i r i c a l CNDO/2f INDO t MINDQ/3 and MNDQ programs A l l t h e s e methods stem from d i f f e r e n t a p p r o x i m a t i o n s upon the d i f f e r e n t i a l o v e r l a p between two AO's, '/•jx. and ^ Xv , which i s d e f i n e d as the p r o b a b i l i t y of f i n d i n g an e l e c t r o n i n a volume element common t o /*>(. and y-v , i . e. ( i ) ( i ) • a. The CNDO/2 program: The CNDO/2, Complete N e g l e c t of D i f f e r e n t i a l O v e r l a p method, v e r s i o n 2, i s p r o b a b l y the most w i d e l y used s e m i - e m p i r i c a l program. In the CNDO method (p.62-79 of R e f . 2 1 ) , a l l i n t e g r a l s i n v o l v i n g d i f f e r e n t i a l o v e r l a p , p^ u-Xv ( J^*^ ) are se t t o z e r o . E l e c t r o n e g a t i v i t i e s of atoms a r e used as e m p i r i c a l d a t a i n the program. The st u d y of m o l e c u l a r geometry a l s o l e d t o c a n c e l l a t i o n of a p e n e t r a t i o n term i n an e a r l i e r v e r s i o n of the method. T h i s term r i s e s from the p e n e t r a t i o n of an e l e c t r o n from an 3tom B t o the s h e l l of a n o t h e r atom A, and i t s i n c l u s i o n y i e l d s a r a t h e r s h o r t b o n d - l e n g t h i n p r e d i c t i n g m o l e c u l a r 91 geometry. The program c a l c u l a t e s t o t a l energy, e i g e n v e c t o r s and e i g e n v a l u e s f o r MO's, M u l l i k e n p o p u l a t i o n , g r o s s charges on atoms and d i p o l e moment. I t can a l s o p e r f o r m geometry o p t i m i z a t i o n s i n c e such r o u t i n e has been adopted as a m o d i f i c a t i o n ( 6 ) . The r e s t r i c t i o n s of the program a r e (1) not f o r t h i r d row elements or beyond; (2) maximum 60 atoms and 170 AO's. b. The INDO program In t h i s I n t e r m e d i a t e N e g l e c t of D i f f e r e n t i a l O v e r l a p method (p.80-83 of R e f . 2 1 ) , a l l i n t e g r a l s w i t h d i f f e r e n t i a l o v e r l a p a r e n e g l e c t e d e xcept the one c e n t e r exchange i n t e g r a l s , KS^y-v, ^ "Xv 'XM-y > where both and 7^ a r e o n fc^e same atom. T h i s m o d i f i c a t i o n t o the CNDO method t a k e s c a r e of the f a c t t h a t r e p u l s i o n between e l e c t r o n s w i t h same s p i n i s s m a l l e r than t h a t w i t h d i f f e r e n t s p i n s . Hence t h i s t r e a t m e n t g i v e s b e t t e r r e s u l t s t o systems where e l e c t r o n s p i n d i s t r i b u t i o n i s i m p o r t a n t , e.g. r a d i c a l s . The INDO program i s implemented s i m i l a r t o the CNDO/2 program. The a d d i t i o n a l o n e - c e n t e r exchange i n t e g r a l s a r e e s t i m a t e d s e m i - e m p i r i c a l l y (p.81-82 of R e f . 2 1 ) . The INDO program i s u s u a l l y i n c l u d e d i n the CNDO/2 program and a c t s as an o p t i o n , which cannot be used f o r m o l e c u l e s w i t h elements h e a v i e r than f l u o r i n e . I t s c o s t i s q u i t e s i m i l a r t o t h a t of CNDO c a l c u l a t i o n s . 92 c. The MTNDO/3 p r o g r a m The MINDO/3 method ( 2 2 ) , M o d i f i e d INDO method, v e r s i o n 3, e x t e n s i v e l y m o d i f i e s the INDO method by the involv e m e n t of v a r i o u s e x p e r i m e n t a l d a t a . M o l e c u l a r geometry, i n c l u d i n g b o n d - l e n g t h s and bond-angles, and heat of f o r m a t i o n a r e the two most i m p o r t a n t t y p e s of e m p i r i c a l d a t a . A c c o r d i n g l y , the MINDO/3 program g i v e s good r e s u l t s f o r ge o m e t r i c o p t i m i z a t i o n . B o n d - l e n g t h i s u s u a l l y c o r r e c t t o 0.02k and bond-angle t o a few degrees ( 2 2 ) . However, IP p r e d i c t i o n i s not v e r y good. R e s t r i c t i o n s of the program a r e : (1) f o r m o l e c u l e s h a v i n g H, B t o F, and S i t o C l o n l y ; (2) l a r g e e r r o r s may occur f o r compounds h a v i n g a d j a c e n t atoms w i t h l o n e - p a i r s of e l e c t r o n s , e.g. N 2H 2, and compounds c o n t a i n i n g t r i p l e bonds. d. The MNDO p r o g r a m An e x t e n s i o n of the INDO t r e a t m e n t i s t o r e t a i n a l l d i f f e r e n t i a l o v e r l a p on th e same atom. Hence, i n t e g r a l s such as <C7^ Xv, y ' s , where ^u.,Xvare on atom A, and Xa ,X* a r e on atom B, a r e not n e g l e c t e d i n the NDDO method ( N e g l e c t of D i a t o m i c D i f f e r e n t i a l O v e r l a p ) . The MNDO program i s such an approach ( 2 3 ) , w i t h the s i m i l a r p a r a m e t e r i z a t i o n t e c h n i q u e used i n t he i m p l e m e n t a t i o n of the MINDO/3 program. A l l the i n t e g r a l s , i n c l u d i n g t he a d d i t i o n a l t w o - c e n t e r r e p u l s i o n i n t e g r a l s , a r e d e t e r m i n e d e i t h e r from e x p e r i m e n t a l d a t a d i r e c t l y or from s e m i - e m p i r i c a l e x p r e s s i o n s which c o n t a i n parameters t o be f i t t e d w i t h e x p e r i m e n t a l d a t a . The e m p i r i c a l d a t a used here 93 are from a broader scope than those used i n the MINDO/3 program, and i n c l u d e heat of f o r m a t i o n , g e o m e t r i c v a r i a b l e s , d i p o l e moments and f i r s t v e r t i c a l I P ' s , e t c . , of some r e f e r e n c e compounds. The r e s u l t s a r e t h a t the two e m p i r i c a l problems w i t h the MINDO/3 program mentioned i n the p r e c e d i n g s e c t i o n have been s o l v e d . More i m p o r t a n t i s t h a t the p r e d i c t e d I P v a l u e s and the o r d e r i n g of MO's i n MNDO agree much b e t t e r w i t h t h o s e deduced from PES, compared t o the r e s u l t s of the MINDO/3 program, as w e l l as thos e of the CNDO and INDO c a l c u l a t i o n s (see a l s o s e c t i o n 4.2D). The r e s t r i c t i o n s of the MNDO program a r e : (1) o n l y f o r m o l e c u l e s c o n t a i n i n g H, B, C, N, 0 and F; (2) up t o 35 atoms, 75 AO's and 50 o c c u p i e d MO's; 4.2C The s e m i - e m p i r i c a l HAM/3 program As mentioned i n c h a p t e r 2, the HAM/3 method i s a s e m i - e m p i r i c a l method u s i n g S l a t e r ' s s h i e l d i n g c o n c e p t . The HAM/3 program (9) uses parameters f i t t e d by many atomic s p e c t r o s c o p i c and PE dat a ( 2 4 ) . I t s performance i n PES s t u d i e s i s v e r y s u c c e s s f u l . B e s i d e s IP (both f o r uv and x-r a y PES) c a l c u l a t i o n s , i t can g i v e e l e c t r o n a f f i n i t i e s , and e x c i t a t i o n e n e r g i e s i n c l u d i n g C I , e t c . A r e c e n t l y m o d i f i e d v e r s i o n (11) has an o p t i o n t o p r e d i c t v a l e n c e - e l e c t r o n shake-up p r o c e s s e s as w e l l . The scope of HAM/3 a p p l i c a t i o n s has been d i s c u s s e d i n a r e c e n t a r t i c l e by Chong ( 2 5 ) . 94 The r e s t r i c t i o n s of the HAM/3 program a r e : (1) f o r compounds h a v i n g H, C, 0, N and F o n l y ; (2) maximum 60 atoms and 122 o r b i t a l s . 4.2D Comparison of the performance of the GAUSSIAN 70 r CNDO/2r  MINDO/3r HAM/3 and MNDO p r o g r a m s . The GAUSSIAN 70, CNDO/2, MINDO/3, HAM/3, and MNDO programs have been used t o c a l c u l a t e I P ' s f o r e i g h t m o l e c u l e s c o n t a i n i n g the N=N or C=N bond ( 2 6 ) . These s m a l l imines and d i i m i n e s have been s t u d i e d p r e v i o u s l y by PES (27, 31, 36, 4 2 ) . As such they p r o v i d e a good t e s t f o r the v a r i o u s c o m p u t a t i o n a l methods. W i t h the GAUSSIAN 70 program, the STO-3G b a s i s s e t i s used f o r a l l the m o l e c u l e s , the 4-31G b a s i s s e t b e i n g r e s e r v e d f o r N 2H 2, CH 2NH and N 2 F 2 . The r e s u l t s of a l l these c a l c u l a t i o n s a r e t a b u l a t e d f o r each m o l e c u l e , t o g e t h e r w i t h some a v a i l a b l e ab i n i t i o r e s u l t s , and a r e compared w i t h the e x p e r i m e n t a l I P ' s (Table 2-9). In a l l c a s e s , the quoted I P ' s a r e v e r t i c a l I P ' s . A l s o shown a r e the CPU time s f o r each c a l c u l a t i o n . A l l c a l c u l a t i o n s were performed on an AMDAHL V6/II computer. The r e s u l t s show t h a t the 4-31G c a l c u l a t i o n s always p r e d i c t t o o h i g h IP v a l u e s . T h i s i s t y p i c a l l y o b t a i n e d w i t h ab i n i t i o SCF c a l c u l a t i o n s (see a l s o c h a p t e r 2) and so a 0.92 f a c t o r i s commonly a p p l i e d t o e m p i r i c a l l y c o r r e c t Koopmans' theorem. On the o t h e r hand, the STO-3G r e s u l t s a r e always too low because TABLE 2 The Experimental and Theoretical IP's of trans-diazene a ' Orbital Symmetry Exptl. IP ° HAM/3 4ag(n+) 10.02 9.72 1au(it) 14.39 14.46 3bu(n") 15.03 15.79 3ag(o) 16.90 17.47 Computing time (sec) 0.3 a . All values 1n eV b. Geometry: rNH = 1.028A, rNN = 1.252A, c Ref. 27. d. Raf. 29. e. Ref. 51. Other ab Initio calculations 4-31G ST0-3G MNDO MINDO/3 CNDO/2 Chong et a l * * von Niessen et 11.04 8.95 11.18 8.47 13.76 10.17 10.01 13.99 12.20 13.78 11.79 17.36 14.71 14.18 17.44 15.69 16.67 13.96 22.76 15.31 15.30 18.17 16.21 17.47 12.87 19.75 17.61 17.03 25.3 4.3 0.8 0.3 0.6 < NNH = 106.85* (28). 96 TABLE 3 The Experimental and Theoretical IP's of trans-methydiazene a ,b Orbital Symmetry 10a' (n+) 2a" ( T N N } 9a1 (n-) 8a' la" 7a' 6a' Exptl. IP c 9.57 12.9 13.4 14.7 15.6 16.7 see text Computing time (sec) HAM/3 8.90 12.83 13.31 14.98 15.33 16.84 19.68 1.0 ST0-3G MNDO MINDO/3 CNDO/2 8.35 10.73 11.34 13.41 14.97 15.73 17.04 21.44 19.3 12.82 13.90 16.01 15.63 17.75 23.25 2.4 8.09 11.01 11.69 12.35 14.42 15.04 19.61 1.0 a. All values in eV b. Geometry: rCH = 1.09A, rCN = 1.47A, rNH = 1.014A, rNN=1.24A, <HCH = 109.5°, <CNN = 112°, and <NNH = 110° (30) c. Ref.27. 14.15 15.55 17.01 20.33 22.37 24.49 26.54 1.5 97 TABLE 4 The Experimental and Theoretical IP's of trans-azomethane a' Orbital Exptl. IP c HAM/3 ST0-3G MNDO MINDO/3 CNDO/2 Symmetry 7ag(n+) 8.98 8.46 8.05 10.52 8.05 12.90 2"u(l,NN) 11.81 11.79 10.56 12.18 10.54 14.34 6bu(n-) 12.30 12.10 12.34 13.32 11.44 17.14 13.60 13.34 13.55 13.83 11.13 16.58 l b9 13.97 14.72 14.42 13.46 20.18 14.50 14.95 15.68 15.81 . 14.71 22.96 5b u 15.08 16.39 16.44 14.53 23.52 15.80 15.55 15.71 16.88 13.90 22.24 18.60 18.12 19.94 21.77 18.65 26.47 22.40 21.58 24.13 28.28 23.52 30.88 Computing time (sec) 1.9 53.7 5.1 2.0 2.5 a- All values in eV b. Geometry: rCH = 1.105A, rCN = 1.482A, rNN * 1 .247A, <CNN = 112.3°, <NCH = 107.5°, and the t i l t angle of the methyl group is -4.1° (32) c Ref. 31. 98 TABLE 5 The Experimental and Theoretical IP's of cis-hexafluoro-azomethane3''5 Orbital Symmetry Exptl. IP HAM/3 ST0-3G MNDO MINDO/3 CNDO/2 13b2(n+) 14an 12 b2 7 b l 6a 2 6 b1 5 32 5 b1 13a. 12a, 1 11 b 2 4a2 10b2 4 b ] l l a 1 3a2 gb2 3^ 10a1 8b2 9a, 8a1 7b, Computing time(sec) a. All values in eV b. Geometry: rNN = <NCF = 109.3° (33) c. Ref. 31. 11.35 9.85 8.06 12. 25 10, ,23 13.72 15.3 14.77 13.54 16. 06 12, ,55 19.02 14.79 12.95 16. ,58 11.48 19.71 15.07 12.82 15. ,98 12, .92 18.49 15.29 13.69 16. ,91 12, .66 20.23 15.47 14.28 16. ,96 13, .48 20.74 15.9 15.73 14.16 17, ,10 13. ,12 21 .77 15.88 13.88 17, .16 13. ,74 21.90 15.95 13.85 16 .80 13 .90 19.87 16.8 16.49 14.37 17 .06 14 .40 21.57 16.55 14.76 17 .25 14 .12 21.81 16.62 15.08 17 .34 15, .09 22.59 16.76 15.46 18 .26 16, .71 21 .93 17.12 15.31 17 .43 15, .94 22.75 17.7 18.02 15.98 17 .82 16, .22 23.27 20.09 19.33 20 .95 17, .93 26.76 20.23 19.25 20 .88 18 .38 26.68 20.26 19.65 21 .15 19 .53 27.51 20.59 19.75 21 .18 19.02 27.75 21.4 21.67 21.48 22 .97 22 .07 28.05 21 .70 21 .11 22 .52 20.74 28.65 23.1 24.52 24.39 26 .44 26 .46 30.97 27.1 26.09 27.78 30 .09 29 .10 35.10 26.0 307.3 21 .6 26. ,9 26.1 i eV i = 1.236A, rCN = 1.490A, rCF = 1.326A, <NNC = 133° and 99 TABLE 6 The Experimental and Theoretical IP's of t rans-d i f luorodiazene a ' b Orbital Exptl. IP d HAM/3C 4-31G ST0-3G MNDO MINDO/3 CNDO/2 Brundle et al .d Symmetry 7a (n+) 13.4 13.21 15.04 11.00 13.86 13.31 17.11 13-92 9 (13.19) 2a 14.1 14.01 15.34 11.64 14.32 11-92 17.40 u (14.32) 6b 15.3 15.05 17.91 13.95 i6.31 9-74 20.91 u (14.59) 6a 15.8 15.85 18.88 14.19 16.58 1 5 - 2 7 19.38 9 (15.82) l b 16.9 16.31 20.05 15.51 16.87 14.12 22.38 9 (16.39) 5b u (17.98) la. 17.68 21.85 17.55 19.33 12.53 25.49 18.7 18.63 21.42 18.04 18.35 16.80 24.65 "U (18.72) 5a 19.8 19.57 22.02 18.14 19 94 29.24 24.67 9 (19.83) 21.0 4b 22.7 22.77 25.97 22.63 24 54 16.84 28.35 u (22.68) 7 Computing time (sec) 0.9 100.3 ' 22.1 2.7 1.3 1.3 a. All values in eV b. Geometry: trans isomer: rNN = 1.231A, rNF = 1 .396A and <NNF •= 105.5*(34); cis Isomer: rNN » 1.214A, rNF « 1 .384A and <NNF = 114.5* (35). c. The numbers inside the parentheses are the IP's of the cis Isomer with their own orbital symmetry. d. Ref. 31. 14.24 16.60 17.50 18.57 20.20 19.80 20.39 24.06 TABLE 7 The Experimental and Theoretical IP's of methylenimine 3 > b This work Other ab Initio calculations Orbital Exptl Symmetry . IP c HAM/3 4-31G ST0-3G MNDO MINDO/3 CNDO/2 Moffatd Lehn et al 6 Kollman et alf Genson et al9 7a ' ( T , N ) la«UCN) 6a'(aCN. o N H) 5a'(ocN) 10.52 10.71 11.42 9.81 11 .35 9.52 14.42 11.06 11.57 11.36 5.94 12.43 12.46 12.16 10.63 12.23 11.25 16.96 11.89 12.11 12.16 8.64 15.13 17.04 15.08 17.37 16.36 18.72 14.85 17.26 15.06 17.73 12.49 15.64 18.99 24.60 16.19 18.45 16.63 18.61 16.77 18.78 13.28 15.17 Computing time (sec) 0.3 44.0 6.3 1 .2 0.6 0.6 a. All values In eV b. Geometry: rCN = 1.273A, rNH = 1. 021 A, rCH = 1.09A, <HNC = 110.4° , <HCH = 117.0° and <NCH(c1s) = 125.1* (37) c. Ref. 36. d. Ref. 38. e. Ref. 39. f. Ref. 40. g. Ref. 41. o o 101 TABLE 8 The Experimental and Theoretical IP's of N-methylmethylen-. . a,b inline O r b i t a l Symmetry E x p t l . I P c HAM/3 ST0-3G MNDO MINDO/3 CNDO/2 1 0 a ' ( T , N ) 9.90 9.97 9.15 10 .88 9.01 14.02 2a-(.CN) 11.38 11.04 9.54 11 .32 10.29 14.63 9 a ' 13 .35 13.41 13.48 13 .63 11.46 16.43 l a " see t e x t 14.82 15.47 15 .07 14.28 22.36 8 a ' 15.1 15.13 15.49 16 .11 13.52 21.20 7 a ' 15 .8 15.95 16.77 16 .56 15.20 24.49 6 a ' 19.38 19.48 20.48 22 .52 19.68 27.26 Computing t ime ( s e c ) 1.0 22.5 2. .9 1.5 1.7 a . A l l v a l u e s i n eV b. Geomet ry : (43) 1. M e t h y l g roup t e t r a h e d r a l and s y m m e t r i c a b o u t CN. rCH = 1.089A\ rCN = 1.44^ 2 . M e t h y l e n e g r o u p : i n n e r hyd rogen rCH = 1.091A. <CCH = 1 2 0 . 5 ° o u t e r hydrogen rCH = 1.081A. <CCH = 1 2 1 . 5 ° 3 . i m i n e g r o u p : rCN = 1.30A1 and <CNC = 1 1 6 . 9 ° c. Re f . 42 . TABLE 9 The Experimental and Theoretical IP's of C-methylmethylenimine Orbital Exptl. IP L HAM/3 Symmetry trans ds trans cis 10a' 10a' 10.18 10.10 9.93 2a" 2a" 11.44 11.41 11.39 9a' 9a' 13.62 13.69 13.38 la" 8a' 14.3 14.78 13.79 8a' la" 15.3 14.92 14.66 7a' 7a' 16.93 15.11 16.90 6a' 6a' 19.09 19.83 18.95 Computing time (sec) a. All values In eV 0.9 1.0 ST0-3G trans cis 9.32 9.31 9.94 9.98 13.71 13.75 15.26 13.96 15.57 15.01 15.74 17.32 20.61 19.85 22.6 22.5 MNDO trans cis 10.08 11.15 12.10 11.88 12.43 13.97 15.83 14.34 15.86 14.80 17.65 17.99 20.96 21.50 3.5 1 .9 MINDO/3 trans cis 9.06 9.24 10.65 10.70 11.98 11.74 14.18 13.02 13.75 14.26 14.39 15.96 20.20 19.07 1.1 b. Geometry: (44) 1. Trans isomer: rCN = 1.273A\ rNH = 1.02lJ(, rC(N)H = 1.092A\ rC(C)H = 1.093&, rCC = 1.525A <CNH = 110.4°, <NCH = 117.0°, <NCC = 121.0° and <HCH = 109.5° 2. Cis isomer: rCN = 1 .273A\ rNH = 1.021A\ rC(N)H = 1.092A\ rC(C)H = 1 .093A\ ""CC <CNH = 110.4°, <NCH = 122.0°, <NCC = 126.0° and <HCH = 109.5° c. Ref. 42. 1 .2 1.523A CNDO/2 trans cis 13.84 13.76 15.02 15.15 16.80 17.42 22.35 19.49 20.74 22.26 22.37 24.27 28.20 26.69 1.7 1.7 o ro 103 the t o t a l energy i s s t i l l q u i t e f a r away from the HF l i m i t . The r e s u l t s of MINDO/3 c a l c u l a t i o n s a r e always too low (1-2eV), and thos e of the CNDO/2 program a r e always too h i g h (2-5eV). Moreover, they always g i v e d i f f e r e n t o r d e r i n g s compared w i t h the GAUSSIAN 70 and o t h e r ab i n i t i o c a l c u l a t i o n s . The MINDO/3 r e s u l t s f o r t h e d i i m i n e s a r e p a r t i c u l a r l y poor due t o i t s i n t r i n s i c problem w i t h t h i s type of m o l e c u l e s . C o n t r a r y t o the r e s u l t s of the s e t h r e e methods, the HAM/3 and MNDO programs, e s p e c i a l l y the former, u s u a l l y g i v e s I P ' s i n v e r y good agreement w i t h the e x p e r i m e n t a l d a t a . Moreover, the o r d e r i n g of the o r b i t a l s i s , i n g e n e r a l , q u i t e c o n s i s t e n t w i t h those p r e d i c t e d by the more e x p e n s i v e ab i n i t i o c a l c u l a t i o n s and those d e r i v e d by o t h e r e x p e r i m e n t a l means, such as.a comparison w i t h o t h e r i s o e l e c t r o n i c s p e c i e s , or the study of the v i b r a t i o n a l s t r u c t u r e o b s e r v e d on PE bands, f o r example. A q u a n t i t a t i v e comparison of t h e s e f i v e methods by the l i n e a r l e a s t square f i t t i n g t e c h n i q u e has been made. To make sure the comparison i s not b i a s e d , t h o s e d a t a t h a t show a s w i t c h i n o r b i t a l energy a r e i g n o r e d , s i n c e some of the c a l c u l a t i o n s ( p a r t i c u l a r l y CNDO/2 and MINDO/3) show i n c o n s i s t e n t o r d e r i n g s . S e l e c t e d I P ' s from each method a r e then used t o p e r f o r m a l i n e a r l e a s t square f i t w i t h e x p e r i m e n t a l v a l u e s . The r e s u l t s a re t a b u l a t e d ( T a b l e 10), and p l o t t e d i n F i g . 1. The average e r r o r and c o r r e l a t i o n c o e f f i c i e n t g i v e an i n d i c a t i o n of the r e l a t i v e u s e f u l n e s s of the methods. Another i m p o r t a n t p o i n t , which i s of much i n t e r e s t t o many In t h i s c e n t r a l d a t a bank, 8K words a r e a l l o c a t e d t o a s t a c k f o r the s t o r a g e of up t o f o u r s p e c t r a which can be d i s p l a y e d i n any TABLE 10 Results of the l inear least square f i t s of the calculated IP's to the experimental IP's Method of IP calculat ions 3 A(eV) B Correlation Average e r r o r 0 coeff ic ient between f i t t i n g after f i t t ing HAM/3 0.526 0.971 0.993 0.35 0.35 "GAUSSIAN 70 (ST03G) 3.182 0.807 0.986 1.15 0.62 MNDO 2.240 0.788 0.981 1.25X 0.72 MINDO/3 3.618 0.798 0.986 1.43 0.62 CNDO/2 1 .176 0.683 0.975 " 5.04 0.87 a. Koopmans' theorem is used except in case of HAM/3. b. 27 data points are used in this f i t t i n g : I P f i t t e d = A + B x I Ptheoretica1 c. Average error between f i t t ing = z A B S ( I P t h e o r e t i c a l - ^experimental } 1 2 7 Average error after f i t t ing = z A B S ( I P f 1 t w d - ^experimental ] 1 2 7 o 105 _j , 1 1 1 1 1 1 1 1 0.0 4.0 B.O 12.0 16.0 20.0 24.0 2B.0 32.0 36.0 THEORETICAL IP (EV) Fig. 1 Results of the l inear least square f i t s of the calculated IP's  to the experimental IP's (The l ines corresponding to GAUSSIAN 70 and MINDO/3 are shifted up by 4eV and 8eV respectively in order to c la r i f y the f igure.) 1 06 the v a l u e of ' c o m p u t a t i o n a l time / e l e c t r o n ' g i v e s a rough base f o r c o s t e s t i m a t i o n , even though the a c t u a l c o s t depends on how f a s t the SCF convergence l i m i t i s r eached, as w e l l as how much main memory i s r e q u i r e d . The c o m p u t a t i o n a l t i m e , i n seconds, of each c a l c u l a t i o n i s shown i n the c o r r e s p o n d i n g t a b l e . The ' c o m p u t a t i o n a l time / e l e c t r o n ' v a l u e s of the c a l c u l a t i o n s are p l o t t e d i n F i g . 2. The p l o t shows the c o s t of the HAM/3 program i s always the l o w e s t among t h e s e f i v e methods and v e r y m i n i m a l compared t o t h a t of the GAUSSIAN 70 program. In c o n c l u s i o n , the GAUSSIAN 70 program a t the STO-3G and 4-31G l e v e l s , the HAM/3 and the MNDO programs appear t o be good programs t o be used i n PES s t u d i e s of m o l e c u l e s where they are a p p l i c a b l e . When the m o l e c u l e i s l a r g e and c o n t a i n s atoms t h a t a r e not p a r a m e t e r i z e d by t h e s e two s e m i - e m p i r i c a l methods, the MINDO/3 and CNDO/2 may be used f o r t r i a l c a l c u l a t i o n s such as g e o m e t r i c o p t i m i z a t i o n . I f f e a s i b l e , the GAUSSIAN 70 or 76 program s h o u l d be used t o g i v e more c o n f i d e n t c o n c l u s i o n s about the c o m p u t a t i o n a l r e s u l t s . 4.2E Use of the RSPT program i n c o r r e c t i n g Koopmans' theorem The t h e o r y of the RSPT method i n c o r r e c t i n g Koopmans' theorem has a l r e a d y been d i s c u s s e d i n c h a p t e r 2. The MO i n t e g r a l s (eqn. 2.29) a r e e v a l u a t e d by the c o r r e s p o n d i n g AO i n t e g r a l s p r e v i o u s l y e v a l u a t e d and s t o r e d by some ab i n i t i o Roothaan-HF c a l c u l a t i o n s such as those from the GAUSSIAN 70 or 76 program. 4-31G b a s i s s e t i s recommended t o be used as a 0 20 40 60 80. 100 Number of electrons in the molecule g. 2 The relative costs of the calculations for each  method expressed in terms of the computational  time / electrons against the total number of electrons in the molecule 108 compromise between a c c u r a c y and c o s t . The RSPT program i s then e x e c u t e d w i t h t h e s e MO i n t e g r a l s t o c a l c u l a t e E 2 , E 3 and the I P ' s . ^Sk1)^1/^' s a r e a l s o p r i n t e d out and i f they a r e too l a r g e , the q u a s i - p a r t i c l e p i c t u r e i s p r o b a b l y not adequate due t o the o c c u r r e n c e of s t r o n g shake-up p r o c e s s e s . D u r i n g the c o u r s e of t h i s s t u d y , t h i s RSPT program has been used t o c a l c u l a t e a c c u r a t e I P ' s f o r m o l e c u l e s such as BHF 2 ( 4 5 ) , C H 3 N O ( 4 6 ) , HBO, HBS, FBO, FBS, C1BO, and C1BS ( 4 7 ) . The r e s u l t s f o r the f i r s t two m o l e c u l e s a r e t a b u l a t e d i n T a b l e 11 and 12 r e s p e c t i v e l y , t o g e t h e r w i t h the e x p e r i m e n t a l I P ' s . The assignments of the two bands of HBF 2 at 18.54 and l8.93eV are based on a comparison of the PE spectrum of HBC1 2 and the v i b r a t i o n a l s t r u c t u r e s of the bands ( 4 5 ) . The breakdown of Koopmans' theorem i n the study of CH 3NO i s d i s c u s s e d i n c h a p t e r 8. T a b l e 13 summarizes the r e s u l t s f o r the s i x l i n e a r boron m o l e c u l e s . These m o l e c u l e s a r e v e r y u n s t a b l e and most of them are s t i l l unknown t o e x p e r i m e n t a l c h e m i s t s . E f f o r t has been b e i n g devoted t o t h e i r s y n t h e s i s and the measurement of t h e i r PE s p e c t r a ( 4 8 ) . Hence these p r e d i c t e d I P ' s w i l l be u s e f u l as r e f e r e n c e s . A l l of t h e s e l a t t e r c a l c u l a t i o n s were done w i t h an AMDAHL V8 computer which i s about 30% more e f f i c i e n t than i t s p r e c e d e n t , the V6 model. The c o s t of t h e s e p e r t u r b a t i o n c o r r e c t i o n s i s a l s o i n c l u d e d i n T a b l e 13, which shows t h a t the program can be used f o r m o l e c u l e s h a v i n g l e s s than 40 b a s i s f u n c t i o n s , but a p p l i c a t i o n s t o m o l e c u l e s l a r g e r than t h a t a r e net q u i t e f e a s i b l e . The a c c u r a c y c f the program, e s t i m a t e d by comparison of the p r e d i c t e d I P ' s w i t h the a v a i l a b l e e x p e r i m e n t a l 109 TABLE 11 Results of the RSPT ca l c u l a t i o n s for HBF O r b i t a l E x p t l b 4-31G AE(3) A ( E G A ) symmetry IP (eV) 4 a l 14. 33 15. 29 14.32 14. 27 3b 2 16. 14 17. 81 16.50 15. 91 17. 97 16.59 16. ,15 l b l 17. 96 19. 60 18.34 17. ,92 2b 2 18. 54 20. 64 19.44 18. ,94 3 a i 18. 93 20. 53 19.20 18, ,81 2 a l 21. 03 22. 44 21.25 '20, .76 average error 1. ,60 0.44 0 .16 a. A l l values i n eV. b. Ref. 45. TABT.E 12 Rpsn l t . s n f t h p RSPT r a l r n l a t i n n s f o r fH-NTL-O r b i t a l E x p t l b 4-31G AE(3) A ( E G A ) symmetry IP 10a' 9.68 11. 20 9. 24 9. 10 9a' 13.8 15. 32 13. 69 13. 65 2a" 14.3 14. ,65 14. 00 14. 00 8a' 15.8 18. .14 16. 37 16. 05 7a' 16.9 18, ,95 16. 39 16. 30 l a " 17 17, .65 16. 39 16. 39 6a' 23 .58 20. 58 20. 46 averaj (only »e error f o r the 1 . 15 0, ,28 0, ,34 f i r s t 3 peaks) a. A l l values in eV. b. Ref. 46. TABLE 13 Results of the RSPT calculations for some linear boron molecules Molecule Orbital Exptl 4-31G *E(3) A ( E U ) (AE) scaled symmetry IP HBO IT 14, .05 14. 25 13. 61 13. 11 13. 76 0 16, .55 16. 77 15. 21 14. 53 15. 50 O 18, .20 17. 00 16. 94 16. 90 HBS IT l l . l l b 10, .87 10. 82 10. 82 10. .74 10. ,86 a 13.54 13 .80 13. 27 13. 16 12. .92 13. ,28 a 15.83 17, .78 15. 48 15. 46 15. ,44 FBO TT 14 .42 14. 10 13. 65 13. .21 13. ,95 a 17 .27 17. 20 15. 84 15. ,04 16. ,30 TT 20 .47 18. 79 18. 24 17. ,89 a 22 .44 20. 93 20. 45 20. ,12 FBS TT 11 .10 10. ,73 10. 73 10. ,72 10, .86 a 14 .62 13. ,90 13. 83 13, .69 14, .08 TT 20 .16 18. ,05 17. 45 17, ,05 0 22 .29 20. ,35 19. 75 18, .34 CIBO TT 13 .58 12. ,79 12. 58 12, .35 12, .85 TT 15 .77 14. ,83 14. 68 14, .53 a 17 .04 16. ,69 15. 46 14, .79 15. .86 a 18 .19 17, ,09 16. 92 16, .76 C1BS TT 10.68C 10 .86 10, ,26 10. 26 10 .26 10. .42 a 13.63 14 .28 13, .29 13. ,25 13 .10 13 .50 TT 14 .85 13, .15 13. 16 13 .15 a 16.77 17 .88 16, .00 16. .00 15 .99 Cost (CPU time in sec) Bond-length (A) 4-31G MO transform. RSPT BO.BS BH.BF.BCl 13.1 9.0 29 1.2 1.169 18 19 58 1.6 1.169 30 32 127 1.2 1.31 36 75 184 1.6 1.30 45 45 245 1.2 1.68 63 77 391 1.6 1.68 a. All I P values in eV. b. Ref. 49. c. Ref. 50. d. Assumed. 1 12 PE d a t a ( i n the case of CH 3NO, o n l y the f i r s t t h r e e peaks are used due the o c c u r r e n c e of shake-up p r o c e s s e s i n the h i g h e r IP r e g i o n ) , i s w e l l w i t h i n 0.5eV. 1 13 4.3 A s m a l l r e a l - t i m e o p e r a t i o n system program f o r the m i c r o - computer c o n t r o l of the s p e c t r o m e t e r s 4.3A Aim of the system program A s m a l l r e a l - t i m e o p e r a t i n g system program has been devel o p e d t o c o n t r o l the PES/PIMS system w i t h a LSI 11/03 microcomputer and some i n t e r f a c i n g hardwares (see a l s o c h a p t e r 3 ) . I t s r o l e i s t o c o n t r o l a s p e c t r o m e t e r f o r s c a n n i n g s p e c t r a , s t o r i n g the s p e c t r a , r e t r i e v i n g n e c e s s a r y s p e c t r a l d ata and m a n i p u l a t i n g t h e s e d a t a . The f o l l o w i n g c r i t e r i a have been taken i n t o account i n the development of t h i s system program: a. The t i m i n g p r o c e s s must be a c c u r a t e t o ensure t h a t the r e s u l t a n t s p e c t r a a r e r e a l . b. The program has t o be easy t o use ( s e l f - e x p l a n a t o r y and s i m p l e ) . c. E f f i c i e n c y i n u s i n g memory and d i s k space i s h i g h . d. I t s h o u l d have some e r r o r h a n d l i n g i n t e l l i g e n c e . e. F u r t h e r m o d i f i c a t i o n s h o u l d be easy. 4. 4B The d e s i g n o f rhp gysfprn p r o g r a m a. The a r r h i t p r t n r e o f t h e p r o g r a m The s t r u c t u r e of the system program i s summarized i n F i g . 3 which r e p r e s e n t s a t o p - t o - b o t t o m d e s i g n and the p o s s i b i l i t y of a bo t t o m - t o - t o p i m p l e m e n t a t i o n . 'RECORD' i s the h e a d q u a r t e r s of Fig.- 3 The s t r u c t u r e of the operating system program RECORD (main) Data acquisition PARAME I. ' I EXTRAC BINARY IECHO QUERY CHARAC SQUEEZ I QUERY QUERY SCAN-L-i 1 n 1 DISK IECHO CHARAC DISPLA I KYINHD—OUT-etc., Data retrieval and storage T DISPLA I KYINHD r ^ BACK  DISK FNAME EXTRAC SQUEEZ QUERY BINARY IRAD50 QUERY ^ SUM  DISK FNAME EXTRAC BINARY QUERY IRAD50 WRITE OUT-DISK FNAME EXTRAC QUERY IRAD50 Data manipulation ADDSUB CHANGE EXTRAC BINARY QUERY SQUEEZ QUERY EXTRAC BINARY IECHO QUERY EXTRAC BINARY IECHO QUERY EXTRAC BINARY I ECHO QUERY EXTRAC BINARY IECHO CLEAR > J — - , EXTRAC QUERY _, r-LEVEL PLOT i n 1 EXTRAC QUERY 1 1 SCALE SEPERA SHOW EXTRAC BINARY IECHO r — 1 1 1 I T 1 1 SMOOTH , '—> EXTRAC BINARY Other services STORE I DISK HELP INFO QUERY EXTRAC BINARY IECHO 1 1 5 the program, which c o n t a i n s the n e c e s s a r y g l o b a l d a t a s t r u c t u r e . 28 s u b r o u t i n e s c o o p e r a t e and p e r f o r m f o u r l e v e l s of s e r v i c e s . The t o p l e v e l , the most i m p o r t a n t p a r t of the program, i s f o r c o n t r o l l i n g a s p e c t r o m e t e r t o scan a spectrum and s t o r i n g the spectrum w i t h r e l a t e d s c a n n i n g i n f o r m a t i o n i m p l i c i t l y . The second l e v e l i s f o r d a t a r e t r i e v a l from some secondary s t o r a g e ( d i s k i n t h i s case) t o the i n t e r a c t i v e system, and e x p l i c i t s t o r a g e and f i l e c r e a t i o n a c c o r d i n g t o the user commands. Data m a n i p u l a t i o n i s performed a t the t h i r d l e v e l where a l l the n e c e s s a r y d a t a are p r e s e n t i n the i n t e r a c t i v e system by the a c t i o n s of the upper l e v e l s . F i n a l l y , the bottom l e v e l t a k e s c a r e of the e r r o r h a n d l i n g and the s i m u l a t i o n of user c o n s u l t a t i o n and i n f o r m a t i o n c e n t e r . b. Data structure The c e n t r a l d a t a bank r e s i d e s i n the main program 'RECORD'. In t h i s c e n t r a l d a t a bank, 8K words a r e a l l o c a t e d t o a s t a c k f o r the s t o r a g e of up t o f o u r s p e c t r a which can be d i s p l a y e d i n any c o m b i n a t i o n s . U s u a l l y , a t most t h r e e s p e c t r a a r e r e q u i r e d f o r an o p e r a t i o n of d a t a m a n i p u l a t i o n ( e . g . C = A - B ) . B e s i d e s , i t i s v e r y r a r e t h a t more than f o u r s p e c t r a have t o be compared at once because i f the spectrum of an unknown m i x t u r e has more than f o u r d i f f e r e n t components, i t w i l l be e x t r e m e l y d i f f i c u l t t o be i n t e r p r e t e d c o r r e c t l y anyway. The reasons f o r the s i z e of the s t a c k as 8K words a r e : (1) The DAC i s a 12 b i t d e v i c e , so i t can o n l y handle 4K 1 16 p o i n t s . W h i l e s c a n n i n g , 4K works a r e needed f o r s t o r i n g the c u r r e n t i n d i v i d u a l scan and a n o ther 4K words a r e needed f o r s t o r i n g the sum of the p r e v i o u s scans f o r d i s p l a y purpose. Hence 8K words a l l o w the most extreme case i n the s c a n n i n g p r o c e s s . (2) To show a spectrum on an o s c i l l o s c o p e , the x and y c o o r d i n a t e s of the p o i n t s are sent t o the o s c i l l o s c o p e one by one and t h i s t r a n s f e r i s l o o p e d u n t i l b e i n g i n t e r r u p t e d . A c o n t i n u o u s c u r v e i s seen because the i l l u m i n a t i o n - r e p e t i t i o n of each p o i n t i s f a s t . However, a r u n n i n g spot w i l l o n l y be seen i f t h e r e a r e t o o many p o i n t s t o be d i s p l a y e d i n one s i n g l e l o o p . T h i s problem f o r s p e c t r u m - d i s p l a y a l s o c o n f i n e s the s i z e of the s t a c k . B e s i d e s the s t a c k , the c e n t r a l data bank c o n t a i n s f o u r s p e c t r u m - s t a t u s t a b l e s ( i d e n t i f y i n g the s p e c t r a ) , and f o u r d i s p l a y - i n f o r m a t i o n t a b l e s ( d e s c r i b i n g how t o d i s p l a y the s p e c t r a ) . The p o i n t e r s t o t h e s e t a b l e s a r e passed t o a s u b r o u t i n e i f n e c e s s a r y . Moreover, the main program a l s o has some o t h e r c o n s t a n t s and parameter l i s t s f o r c a l l i n g s u b r o u t i n e s , as i t s l o c a l d a t a s t r u c t u r e . S i m i l a r l o c a l d ata s t r u c t u r e s may be d e f i n e d i n some s u b r o u t i n e s . A l l s u b r o u t i n e c a l l s a r e made by u s i n g R5 ( r e g i s t e r 5) as the p o i n t e r t o the p a r a m e t e r - l i s t which c o n t a i n s a l l n e c e s s a r y means f o r communication between the two r o u t i n e s . The f i r s t word of the parameter l i s t a lways i n d i c a t e s the number of parameters i n the l i s t . T h i s format has been kept t h r o u g h o u t the whole program 1 1 7 c o n s i s t e n t l y . No d a t a i s d e c l a r e d as g l o b a l , except the s u b r o u t i n e names, so the a c c e s s t o every datum i s t i g h t l y c o n t r o l l e d i n p a s s i n g the p a r a m e t e r - l i s t . c. Memory management The 8K words i n the s p e c t r a l s t a c k a r e o r g a n i z e d as f o u r f l o a t i n g segments. P r i o r i t y i s a s s i g n e d t o each segment such t h a t the s m a l l e r the segment number, the h i g h e r the p r i o r i t y . Hence, the most i m p o r t a n t spectrum i s spectrum 1 which r e s i d e s i n segment 1 (head of the s t a c k ) . Whenever a new spectrum i s t o be brought i n , the s i z e of the o l d spectrum ( b e a r i n g the same spectrum number) w i l l be a d j u s t e d t o f i t the new one. Hence, i f the incoming one i s l a r g e r than the o l d one, the segments be h i n d t h i s segment w i l l be moved down by c e r t a i n amounts. Some da t a at the end of the s t a c k , which have the l o w e s t p r i o r i t y t o be kept i n the s t a c k , may be l o s t . The f l o a t i n g scheme makes use of the 8K words more e f f i c i e n t l y , a l t h o u g h some overhead i s i n v o l v e d t o update the s t a t u s t a b l e s of the a f f e c t e d s p e c t r a and t o move the segments eve r y time when a new spectrum i s t o be brought i n . d. F i l e management Each s p e c t r a l d a t a f i l e has an i n f o r m a t i o n b l o c k as i t s f i r s t b l o c k (1 b l o c k = 256 words), and then s e v e r a l b l o c k s of d a t a . The f i r s t 60 b y t e s of the i n f o r m a t i o n b l o c k a r e the 1 18 parameter f i e l d . The 62th t o 128th b y t e s a re the d e s c r i p t i o n of the s p e c t r a i n the f i l e . At p r e s e n t , t h e r e a r e o n l y 7 parameters i n the parameter f i e l d , each of which has a f i x e d l e n g t h of 4 b y t e s ( l e f t - a d j u s t e d and packed w i t h b l a n k s ) . The parameters a r e : (1) number of s p e c t r a i n the f i l e ; (2) s i z e of each spectrum i n number of b l o c k s ; (3) scan r a t e i n m s e c / p o i n t ; (4) number of scans per s p e c t r a ; (5) s t a r t p o i n t number (where the s c a n n i n g s t a r t s ) ; (6) number of p o i n t s per s c a n s ; (7) s t e p - s i z e of the ramp output t o the s p e c t r o m e t e r . These parameters t o g e t h e r w i t h the s h o r t d e s c r i p t i o n i n the i n f o r m a t i o n b l o c k document and i d e n t i f y the d a t a f i l e and i t s d a t a . The r e m a i n i n g space i n the i n f o r m a t i o n b l o c k i s r e s e r v e d f o r f u r t h e r m o d i f i c a t i o n . When a new f i l e i s t o be c r e a t e d , the program checks whether the f i l e a l r e a d y e x i s t s . I f so, i t askes i f the user wants t o o v e r w r i t e t h a t f i l e . T h i s saves the f i l e s from a c c i d e n t a l d e s t r u c t i o n . e. R e l i a b l i t y of rhe spprrral r e s u l t.S S i n c e the t i m i n g p r o c e s s has t o be a c c u r a t e d u r i n g s c a n n i n g , keyboard i n t e r r u p t t o handle i n t e r a c t i v e user commands i s o n l y e n a b l e d a f t e r the c l o c k i s o f f ( s p e c i f i e d s c an-time has 1 19 e x p i r e d , and CPU i s d o i n g d a t a t r a n s f e r , t e s t i n g end of scan e t c . ) , but i s d i s a b l e d b e f o r e the c l o c k i s on. By d o i n g so, the scan-time i n t e r v a l w i l l be e x a c t . The sum of p r e v i o u s scans b e i n g d i s p l a y e d can .be s c a l e d up or down by a s h i f t i n g f a c t o r ( i n t e r a c t i v e l y c o n t r o l by keyboard i n t e r r u p t s ) d u r i n g the s c a n n i n g p r o c e s s f o r a b e t t e r d i s p l a y . However, t h i s i s done by some b u f f e r r e g i s t e r s so the c o n t e n t s i n the s t a c k does not change a t a l l . Hence, t r u n c a t i o n e r r o r s w i l l be a v o i d e d . On the o t h e r hand, b e f o r e a spectrum i s w r i t t e n t o d i s k , i t w i l l be changed back t o i t s o r i g i n a l form as from a scan or a d a t a f i l e w i t h s c a l e f a c t o r as one. A c c o r d i n g l y , the da t a i n a d a t a f i l e always r e p r e s e n t the r e a l spectrum. f. R e l i a b i l i t y of the program Two back-up f i l e s on the system d i s k have been s e t up s p e c i f i c a l l y t o improve the r e l i a b i l i t y of the system program. W h i l e the system i s p e r f o r m i n g a d a t a m a n i p u l a t i n g command, t h e r e i s a h i g h p r o b a b i l i t y t h a t the c e n t r a l d a t a bank w i l l be changed. In o r d e r t o r e c o v e r any m i s t a k e s , the p r e s e n t c e n t r a l d a t a bank i s saved i n one of t h e s e two back-up f i l e s . I n case of a u s e r ' s m i s t a k e or a system m a l f u n c t i o n , the user may s t i l l r e l o a d the d a t a b e f o r e the l a s t command by i s s u i n g a s i n g l e s i m p l e 'RELOAD' command. By d o i n g t h i s , the user w i l l have e x a c t l y the same da t a i n the i n t e r a c t i v e system as i f the wrong command had not been i s s u e d a t a l l . T h i s 'RELOAD' command, as 1 20 the o t h e r d a t a m a n i p u l a t i n g commands, w i l l a l s o awake the back-up p r o c e s s ( i n another back-up f i l e a l t e r n a t i v e l y ) b e f o r e i t s o p e r a t i o n . Hence, any d a t a l o s t i n a wrong 'RELOAD' command can s t i l l be r e c o v e r e d . S i n c e t h e r e a r e o n l y two back-up f i l e s , one s t o r i n g the p r e s e n t d a t a and a n o t h e r s t o r i n g the d a t a b e f o r e the l a s t command, o n l y d a t a b e f o r e the l a s t command can be r e c o v e r e d , but n o t h i n g b e f o r e t h a t . The back-up p r o c e s s s t o p s at t h i s p o i n t because the s i z e of the c e n t r a l d a t a bank i s q u i t e l a r g e (34 b l o c k s ) . However, a d d i t i o n a l back-up f e a t u r e s w i l l be q u i t e easy t o be i n s e r t e d t o the p r e s e n t v e r s i o n . At some c r i t i c a l p o i n t s where e r r o r s may cause d i s a s t e r s , a query i s always i s s u e d t o urge the user t o make a d e c i s i o n b e f o r e the c u r r e n t p r o c e s s i s pu r s u e d . Examples are i n p u t e r r o r s , .data o v e r f l o w i n m u l t i p l i c a t i o n , and da t a p o i n t s out of range, e t c . g. F u n c t i o n s of the s u b r o u t i n e s In o r d e r t o make the i m p l e m e n t a t i o n and f u r t h e r m o d i f i c a t i o n e a s i e r , the whole program i s p a r t i t i o n e d i n t o 28 s u b r o u t i n e s . The f u n c t i o n s of the s e s u b r o u t i n e s are' summarized below: (1) ADDSUB: a d d i t i o n or s u b t r a c t i o n of two s p e c t r a (2) BACK: t a k e d a t a back from d i s k t o memory (3) BINARY: c o n v e r t an ASCII d i g i t a l s t r i n g t o b i n a r y (4) CHANGE: change the v a l u e s of some p o i n t s i n a spectrum (5) CHARAC: c o n v e r t a b i n a r y number t o an ASCII s t r i n g (6) CLEAR: c l e a r a spectrum out 121 (7) DISK: read or w r i t e on d i s k ( 8 ) DISPLA: d i s p l a y some s p e c t r a on o s c i l l o s c o p e (9) EXTRAC: i n p u t some arguments from t e r m i n a l ' ( 1 0 ) FNAME: c o n v e r t an ASCII s t r i n g t o RAD50 format of a v a l i d f i l e - n a m e ( 1 1 ) HELP: show the user some h e l p f u l i n f o r m a t i o n of how to use the system ( 1 2 ) IECHO: echo a b i n a r y number t o t e r m i n a l (13) INFO: show and modify i n f o r m a t i o n and d i s p l a y - s t a t u s of a spectrum (14) KYINHD: i n t e r p r e t d a t a m a n i p u l a t i n g commands and c a l l s u i t a b l e s u b r o u t i n e s (15) LEVEL: l e v e l out some s p i k e s i n a spectrum ( 1 6 ) OUT: go out of the d i s p l a y l o o p (17) PARAME: i n p u t s c a n n i n g p a r a m e t e r s ( 1 8 ) PLOT: p l o t a spectrum (19) QUERY: ask u s e r ' s d e c i s i o n a t some c r i t i c a l p o i n t (20) SCALE: s c a l e up or down a spectrum (21) SCAN: c o o r d i n a t e some ou t p u t v o l t a g e s , a r e a l - t i m e c l o c k and a c o u n t e r t o scan a spectrum and s t o r e i t i n t o memory and d i s k f i l e (22) SEPERA: move a spectrum up or down r e l a t i v e t o the b a s e - l i n e (23) SHOW: show the v a l u e s of some p o i n t s of a spectrum (24) SMOOTH: smooth a spectrum (25) SQUEEZ: squeeze out a h o l e i n memory f o r a new spectrum 122 (26) STORE: save or r e l o a d the c e n t e r d a t a bank (27) SUM: sum up some s i m i l a r s p e c t r a i n a da t a f i l e (28) WRITE: w r i t e data i n memory t o a data f i l e 4.3C Imp l e m e n t a t i o n of the d e s i g n With t h i s system d e s i g n , the i n p u t / o u t p u t s u b r o u t i n e s such as 'BAINARY', 'CHARAC*, 'DISK', 'EXTRAC, 'FNAME', 'IECHO' and 'QUERY' a r e w r i t t e n i n d e p e n d e n t l y and t e s t e d w i t h a s i m p l e c a r r i e r program (a s i m p l e program w i t h minimal d a t a s t r u c t u r e t o c a l l the t e s t i n g s u b r o u t i n e ) . In the elementary form, the n u c l e u s of the program j u s t c o n s i s t s of the main program 'RECORD', the s u b r o u t i n e 'SCAN' ( u s i n g d e f a u l t s c a n n i n g parameters so t h a t 'PARAME' and 'SQUEEZ' are not n e c e s s a r y ) , the s u b r o u t i n e 'DISPLA' ( w i t h m i n i m a l keyboard i n t e r r u p t o p t i o n s ) , and the s u b r o u t i n e 'KYINHD' ( j u s t p r i n t a message and e x i t the system program i n o r d e r t o l e a v e the i n f i n i t e d i s p l a y l o o p ) . A f t e r h a v i n g t h i s s m a l l n u c l e u s w o r k i n g p r o p e r l y , o t h e r s u b r o u t i n e s a r e devel o p e d and l i n k e d t o the n u c l e u s . I n i t i a l l y , the command t a b l e of 'KYINHD', which i s used t o i n t e r p r e t the data m a n i p u l a t i n g commands, has a l i n k t o a s i n g l e dummy s u b r o u t i n e no mat t e r what command i s i s s u e d by the u s e r . Then when a new d a t a m a n i p u l a t i n g s u b r o u t i n e has been d e v e l o p e d , the g l o b a l a d d r e s s of t h i s s u b r o u t i n e i s added t o the proper e n t r y t o s e t up a p r o p e r l i n k i n s t e a d of the dummy l i n k . Hence, the a d d i t i o n of a new s u b r o u t i n e a f f e c t s o n l y two data e n t r i e s ( d e c l a r e g l o b a l and add l i n k ) of 'KYINHD' but not a l l 123 the r e s t . T h i s procedure makes the i m p l e m e n t a t i o n of the system program easy and e f f e c i e n t . On the o t h e r hand, f u t u r e m o d i f i c a t i o n i s more f l e x i b l e . 4.3D R e s u l t s and D i s c u s s i o n A s m a l l r e a l - t i m e o p e r a t i n g system has been developed t o f a c i l i t a t e the PES/PIMS system. The system program has been used f o r about one year and i t s performance p r o v e s t h a t the o b j e c t s of t h i s s o f t w a r e development have been f u l f i l l e d . The arguments i n v o l v e d i n the system d e s i g n a r e i n g e n e r a l j u s t i f i e d . The most i m p o r t a n t f e a t u r e s of t h i s system program a r e : a. the program i s easy t o use; b. i t i s w e l l documented and f u l l y m o d u l i z e d ; hence, f u r t h e r m o d i f i c a t i o n w i l l be easy; c. the use of memory and d i s k space i s e f f i c i e n t and f u r t h e r e x p a n s i o n of the program i s f e a s i b l e ; d. the d a t a back-up d e s i g n i s v e r y u s e f u l . Based on p a s t e x p e r i e n c e , the f o l l o w i n g m o d i f i c a t i o n s a r e s u g g e s t e d : a. Some of the microcomputer system (RT 11) r o u t i n e s , such as the system f i l e d i r e c t o r y and system 'date' r o u t i n e s , e t c . , may be u s e f u l . With the a c c e s s t o the d a t a s t r u c t u r e of these r o u t i n e s , the p r e s e n t f i l e system can be improved t o g i v e f e a t u r e s such as f i l e l i s t i n g , f i l e s c a n n i n g w i t h the f i l e names 124 or date of f i l e c r e a t i o n , f i l e d u p l i c a t i o n , and f i l e d e l e t i o n , e t c . b. A system s u b r o u t i n e '.PRINT' has been used f o r o u t p u t i n g a message t o the t e r m i n a l . T h i s r o u t i n e has caused some problems i n the i m p l e m e n t a t i o n of the system program and a t i m e - d e l a y t e c h n i q u e has been used t o e m p i r i c a l l y a v o i d these problems. A b e t t e r remedy i s t o w r i t e the c o r r e s p o n d i n g r o u t i n e e x p l i c i t l y i n o r d e r t o have a t i g h t c o n t r o l . c. 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L e t t . , 2 2 ( 1 9 7 3 ) 4 9 5 . 50. C. K i r b y , H.W. K r o t o and N.P.C. Westwood, J . Am. Chem. S o c , 100(1978)3766. 51. W. von N i e s s e n , W. Domcke, L.S. Cederbaum and W.P. Kraemer J . Chem. Phys., 67(1977)44. 1 29 PART I I I System A p p l i c a t i o n s 130 111A. A Study of Some S u l f u r N i t r i d e s - Si,Ni, . S 7 N 7 . Si.N?, and T h i s s e c t i o n d e s c r i b e s an i n v e s t i g a t i o n by Hel PE and PIM s p e c t r o s c o p i e s of some s m a l l s u l f u r - n i t r o g e n m o l e c u l e s . The i n t e r e s t here i s i n the i n t e r r e l a t i o n s h i p between these s p e c i e s which can be summarized i n the f o l l o w i n g diagram: Routes A and B a r e co v e r e d i n Chapter 5; C i s d e s c r i b e d i n Chapter 6, and D i n Chapter 7. The r a t i o n a l e f o r the i n t e r e s t may be summarized below: 1. The g e n e r a t i o n of d i s c r e t e s u l f u r - n i t r o g e n m o l e c u l e s f o r s tudy by PES/PIMS system. From the p o i n t of view of the 131 above diagram t h i s a l s o p r o v i d e s s p e c i f i c i d e n t i f i c a t i o n when a n a l y z i n g m i x t u r e s and u n d e r t a k i n g spectrum s t r i p p i n g p r o c e d u r e s . 2. The PE s p e c t r a of S„N a, S 2 N 2 , and SUH2 may be i n t e r -p r e t e d ( w i t h the a s s i s t a n c e of MO c a l c u l a t i o n s ) i n order t o e v a l u a t e t h e i r e l e c t r o n i c s t r u c t u r e s . S«N 2(Chapter 6) has not been s t u d i e d p r e v i o u s l y by UPS due t o i t s i n s t a b i l i t y . 3. The n a t u r e of the s p e c i e s o b t a i n e d i n the gas phase by v a p o r i z i n g the (SN)* polymer has not been u n e q u i v o c a l l y e s t a b -l i s h e d p r e v i o u s l y . E x t e n d i n g 1. and 2. above, i t i s shown t h a t : (a) v a p o r i z a t i o n of (SN) X produces almost 100% of a new s p e c i e s ; (b) t h i s same s p e c i e s i s produced i n a p p r e c i a b l e amounts by c r a c k i n g SKN,, over g l a s s w o o K C h a p t e r 5 ) ; (c) i t i s suggested t h a t the new s p e c i e s i s the p r e v i o u s l y unknown m o l e c u l e S 3 N 3 , a r a d i c a l s p e c i e s , and (d) the ge o m e t r i c and e l e c t r o n i c s t r u c t u r e of t h i s s p e c i e s i s of c o n s i d e r a b l e i n t e r e s t . These items a r e the s u b j e c t of Chapter 7. S i n c e S 2 N 2 and p a r t i c u l a r l y S q N , , a r e p i v o t a l m o l e c u l e s i n the above scheme, they a r e d i s c u s s e d i n the next c h a p t e r , t o g e t h e r w i t h d e t a i l s of the p y r o l y s i s of S 4N t t over s i l v e r and g l a s s w o o ls. T h i s w i l l s e t the scene f o r the i n v e s t i g a t i o n of the Si,N 2 and S 3 N 3 m o l e c u l e s i n the subsequent c h a p t e r s . 1 32 Chapter 5 T e t r a s u l f u r t e t r a n i t r i d e , SuNn and d i s u l f u r d i n i t - r i d e , S?N 7 5. 1 I n t r o d u c t i o n S 9N f t i s e s t a b l i s h e d as the most well-known and c h a r a c -t e r i z e d s u l f u r - n i t r o g e n compound, p r o v i d i n g the s t a r t i n g p o i n t f o r much of the subsequent s u l f u r - n i t r o g e n c h e m i s t r y . T h i s background i s f u l l y c o v e r e d i n the r e v i e w s of H e a l ( l , 2 ) and R o e s k y ( 3 ) . Of some r e l e v a n c e , however, i s the n a t u r e of the s t r u c t u r e , which has been shown by e l e c t r o n d i f f r a c t i o n of the v a p o r ( 4 ) and X - r a y d i f f r a c t i o n of the c r y s t a l ( 5 ) t o p o s s e s s the D 24 shape i l l u s t r a t e d i n F i g 1. I r and Raman s p e c t r a ( 6 , 7 ) , the e l e c t r o n i c a b s o r p t i o n s p e c t r u m ( 8 ) , the 1 a N NMR s p e c t r u m ( 9 ) , t h e s o l i d s t a t e X - r a y PE s p e c t r u m ( 1 0 ) , and, more germane, the Hel(10,11) and H e l l ( 1 1 ) PE s p e c t r a , have a l l been measured f o r t h i s i n t e r e s t i n g m o l e c u l e . The e l e c t r o n i c s t r u c t u r e of S^N, has been s t u d i e d by CND0(12-14), EH(15), X O ( 1 6 ) , and ab i n i t i o ( n ) methods. M u l l i k e n p o p u l a t i o n a n a l y s i s by the l a t t e r method(11) shows t h a t a t o t a l of 0.8036 e l e c t r o n s i s donated from a s u l f u r atom t o a n i t r o g e n atom, t h e r e b y p r o v i d i n g t h e o r e t i c a l ground f o r the n i t r o g e n atoms b e i n g the n u c l e o p h i l i c s i t e s . The t r a n s -f o r m a t i o n of c a n o n i c a l w a v e f u n c t i o n s t o l o c a l i z e d o r b i t a l s ( 1 1 ) a l s o shows t h a t some c r o s s - r i n g bonding e x i s t s between a d j a c e n t p a i r s of s u l f u r atoms. T h i s i s a l s o r e f l e c t e d by the r a t h e r s h o r t S-S s e p a r a t i o n ( 2 . 5 8 A ) . A bond o r d e r of about 0.3 has been proposed by some s e m i - e m p i r i c a l c a l c u l a t i o n s ( 1 0 , 1 5 ) . Fig. 1 The molecular structure of S.N. (Ref. 5) 1 34 Among the many d i v e r s e r e a c t i o n s of S „ N t t , the t h e r m a l d e c o m p o s i t i o n has g a i n e d p a r t i c u l a r a t t e n t i o n because i t i s the p r i n c i p a l method f o r the s y n t h e s i s of the r e c e n t l y e s t a b l i s h e d i n o r g a n i c m e t a l ( S N ) ^ , p o l y m e r i c s u l f u r n i t r i d e ( 1 7 - 1 9 , 3 2). S 2 N 2 i s the major p r o d u c t o b t a i n e d by p a s s i n g S ^ N , vapor over s i l v e r wool a t 200-300°C. The S 2 N 2 vapor condenses as a c o l o r l e s s d i a m a g n e t i c s o l i d which upon warming changes r a p i d l y t o a paramagnetic b l u e f i l m . I t then undergoes a slow s o l i d s t a t e p o l y m e r i z a t i o n and forms the d i a m a g n e t i c ( S N ) * c r y s t a l s ( 1 8 , 1 9 ) . The i d e n t i t y and r e l a t i v e abundance of o t h e r s i d e p r o d u c t s and i n t e r m e d i a t e s i n t h i s p y r o l y s i s a r e unknown. S « N 2 , S 3 N 3 and SN have been c l a i m e d t o occur i n t h i s s y s t e m ( 2 0 ) . The ( S N ) X polymer can a l s o be formed from S « , N i , vapor passed over Pyrex or q u a r t z wool a t e l e v a t e d t e m p e r a t u r e s ( 2 1 ) . . An a c y c l i c isomer of S a N „ , p r e v i o u s l y c l a i m e d as the major s p e c i e s s u b l i m e d from ( S N ) X (22) has been su g g e s t e d as the p r i m a r y i n t e r m e d i a t e ( 2 1 ) . More r e c e n t l y , a mass s p e c t r o m e t e r i c study has showed t h a t the d i r e c t p y r o l y s i s p r o d u c t s a r e a c t u a l l y a m i x t u r e , i n c l u d i n g S „ N 2 , S 3 N 3 , SN and S 2 ( 2 0 ) . However, the p r e c u r s o r ( s ) t o the ( S N ) X f i l m s t i l l remain unknown, and t h i s i s one of the problems a d d r e s s e d i n thes e t h r e e c h a p t e r s . S 2 N 2 , b e s i d e s b e i n g an i n t e r m e d i a t e t o the ( S N ) X polymer, i s an i n t e r e s t i n g s p e c i e s by i t s e l f . I t s m o l e c u l a r geometry has been shown, by X-ray c r y s t a l l o g r a p h y ( 2 3 ) , t o be square p l a n a r w i t h a l t e r n a t i n g s u l f u r and n i t r o g e n atoms. The bond l e n g t h s a r e p r a c t i c a l l y e q u a l , w i t h an average v a l u e of 1.654A. The c o l o r l e s s c r y s t a l s p o l y m e r i z e t o ( S N ) X even a t 0°C and can be 1 35 s u b l i m e d at 10" 2 t o r r . The c h e m i c a l and p h y s i c a l p r o p e r t i e s have been e x t e n s i v e l y reviewed(1 -3). The e l e c t r o n i c s t r u c t u r e of S 2 N 2 has been s t u d i e d t h r o u g h i t s Hel PE spec t r u m ( 1 1 , 2 4 ) , H e l l PE s p e c t r u m ( 1 1 ) , X-ray PE spectrum of the s o l i d ( 2 5 ) , and s e v e r a l t h e o r e t i c a l c a l c u l a t i o n s , i n c l u d i n g an i n v e s t i g a t i o n of the p o s s i b l e p o l y m e r i z a t i o n mechanism(16). A more r e c e n t ab i n i t i o s t u d y ( 1 l ) shows the d o n a t i o n of 0.6852 e l e c t r o n s from the s u l f u r atom t o the n i t r o g e n atom, and the absence of c r o s s - r i n g bonding. Weak shake-up e f f e c t s o b s e r v e d i n the i n n e r v a l e n c e r e g i o n ( 2 4 ) have been q u a n t i t a t i v e l y e v a l u a t e d by Green's f u n c t i o n c a l c u l a t i o n s (26) . In t h i s c h a p t e r , the p y r o l y s i s of the S„Ntt vapor over s i l v e r wool and Pyrex wool has been s t u d i e d by the PES/PIMS c o m b i n a t i o n . The presence of a d i s c r e t e u n s t a b l e s p e c i e s , S 3 N 3 , as one of the p y r o l y s i s p r o d u c t s ( 2 0 ) i s e s t a b l i s h e d , p r e p a r i n g the ground f o r the work d i s c u s s e d i n Chapter 7. 5.2 E x p e r i m e n t a l The a p p a r a t u s employed i n t h i s work i s i l l u s t r a t e d i n F i g 2. The sample o u t l e t was p l a c e d as c l o s e as p o s s i b l e t o the i o n i z a t i o n p o i n t ( a b o u t 2cm) t o m i n i m i z e the d e c o m p o s i t i o n of any r e s u l t a n t t r a n s i e n t s p e c i e s . The S„N a s o l i d was p l a c e d a t the end of the bent tube and heated by a h e a t i n g tape wrapped around the t u b e . Pyrex or s i l v e r wool was plugged l o o s e l y i n the s t r a i g h t tube and heated w i t h a n o t h e r h e a t i n g t a p e . The s i l v e r wool was c l e a n e d b e f o r e use w i t h n i t r i c a c i d . Temperatures were vacuum chamber Pyrex or -silver wool to mass ana1y7er sample reservoir pump out to electron analyzer heater 1 heater 2 PE/PIM spectrometer Fig. 2 The experimental setup for the pyrolysis of S.N, into the PE/PIM spectrometer 1 37 r e c o r d e d by two thermometers i n s e r t e d between the tube and the h e a t i n g t a p e s . 5.3 Results A . The S , , N , , vapor The Hel PE s p e c t r u m ( F i g 3 ) , the Hel mass s p e c t r u m ( F i g 4a) and the HLapr mass s p e c t r u m ( F i g 4b) were o b t a i n e d by h e a t i n g the whole tube a t 80°C, w i t h o u t p u t t i n g any s i l v e r or Pyrex wool i n the t u b e . The PE spectrum i s c o n s i s t e n t w i t h the l i t e r a t u r e r e s u l t s ( 1 0 , 1 1 ) and the mass s p e c t r a a r e comparable t o the mass d a t a o b t a i n e d by o t h e r methods(22,27), ke e p i n g i n mind the competing e f f e c t s of mass d i s c r i m i n a t i o n i n our mass a n a l y z e r , and the low energy l i g h t s o u r c e used f o r p h o t o i o n i z a t i o n . B . SnNf l vapor over s i l v e r wool The S „ N „ vapor was g e n e r a t e d by h e a t i n g the S « N „ s o l i d t o 80°C. The s i l v e r wool was heated t o 260°C. The c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s was a f u n c t i o n of t i m e , but e v e n t u a l l y (about 45 mins) reached a stea d y s t a t e . T h i s change i s p l o t t e d i n F i g 5. The major c o n s t i t u e n t s a r e S a N „ , S 3 N 3 and S 2 N 2 . The i d e n t i f i c a t i o n i s a s s i s t e d by t h e i r i n d i v i d u a l Hel PE s p e c t r a and the mass s p e c t r a r e p o r t e d i n t h i s c h a p t e r and Chapter 7. The r e l a t i v e mole f r a c t i o n s were r o u g h l y e s t i m a t e d from the r e l a t i v e i n t e n s i t y of each s p e c i e s i n the PE and mass s p e c t r a a t e p a r t i c u l a r t i m e . The r e f e r e n c e s used f o r t h i s p r o c e d u r e were the i n t e n s i t i e s and the s c a n n i n g time of the c o r r e s p o n d i n g pure J I I I I I 1 1 1 L 10 12 14 16 1 8 IONIZATION POTENTIAL Fig. 3 The Hel PE spectrum of S.N. 139 140 Relative partial pressure Time (min) Fig. 5 The time dependence of the composition of the pyrolysis  products of S^N^ over s i lver wool (s i lver wool at 260"C  and S^N^s) at 80°C) 141 s p e c t r a of each i n d i v i d u a l s p e c i e s . T h i s p l o t ( s i m i l a r l y f o r F i g 10), however, i s e s s e n t i a l l y f o r q u a l i t a t i v e comparison of m i x t u r e c o m p o s i t i o n s . The Hel PE spectrum and the HLo^r mass spectrum of the p y r o l y s i s p r o d u c t s j u s t b e f o r e t h e s t e a d y s t a t e was reached a r e shown i n F i g 6a and 6b r e s p e c t i v e l y . U s i n g the spectrum s t r i p p i n g t e c h n i q u e , each spectrum was d e c o n v o l u t e d i n t o p a r t s 1, 2, 3 and 4. They c o r r e s p o n d , i n t u r n , t o s p e c t r a 'of S 3 N 3 ( F i g 3 and 4 of Chapter 7 ) , S,N,, S 2 N 2 , and N 2 . At t h e s t e a d y s t a t e , S 2 N 2 i s t h e o v e r w h e l m i n g l y predominant s p e c i e s . I t s Hel PE spectrum i s shown i n F i g 7, which i s c o n s i s t e n t w i t h t h o s e a v a i l a b l e i n the l i t e r a t u r e { 1 1 , 2 4 ) . I t s Hel mass spectrum and H L a e r mass spectrum a r e shown i n F i g 8a and 8b r e s p e c t i v e l y . C. S a N t vapor over Pyrex wool The c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s was independent of time but s e n s i t i v e t o temperature and pumping speed. The r e s u l t s under d i f f e r e n t c o n d i t i o n s a r e summarized below. 1. No o b v i o u s d i f f e r e n c e s from the s p e c t r a of pure S„Nft were o b s e r v e d below 200°C. 2. At 240°C, w i t h f a s t pumping i n o p e r a t i o n , about 20% S 3 N 3 was o b t a i n e d . No o t h e r s p e c i e s g a i n e d enough i n t e n s i t y t o be i d e n t i f i e d by e i t h e r PE or mass s p e c t r a . With slow pumping, Sj,N 2 s t a r t e d a p p e a r i n g , demonstrated by a s m a l l peak of S u N z " i n the HLofir mass spectrum. 142 (b) 4 (a) 4 [A (b) 3 1 (a) 3 (b) 2 I . » I i i A K . H I ' (b) 1 A « k (b) A. i , . , l l i i t l l l i i l (a) J 1 l _ ft 50 100 150 amu 10 14 eV Fig. 6 The pyrolysis products of S^N^ over silver won! at. 260*0  before the steady state (a) The Hel PE spectrum of the product mixture (b) The HL PIM spectrum of the product mixture Each spectrum is deconvoluted to the corresponding parts of i ts constituents: 1 - S 3 N 3 2- S 4 N 4 3. S 2 N 2 4. N0 (cannot be ionized by HL n ) ' i i i i 1 1 1 r 10. 12 14 16 18 IONIZATION POTENTIAL Fig. 7 The Hel PE spectrum of 144 s (b) V " + • S2N j S 2 N 2 S 3 N 3 \ A_J\ L, A k i i i i amu Fig. 8 The PIM spectra of S^N ,^ recorded with (a) the Hel and (b) the HL „ l ight sources -— 1 a3y 145 3. At 260°C, w i t h slow pumping, a d d i t i o n a l S 3 N 3 and S<,N2 were formed. S 2 N 2 and N 2 a l s o s t a r t e d a p p e a r i n g a t t h i s s t a g e . 4. At 280°C, w i t h slow pumping, most of the S „ N , decomposed i n t o S„N 2, S 2 N 2 and S 3 N 3 , i n d e c r e a s i n g o r d e r of c o n c e n t r a t i o n . An i n c r e a s e of N 2 and a t r a c e of S 2 were a l s o o b s e r v e d . The Hel PE and HLafir mass s p e c t r a a t t h i s p a r t i c u l a r s t a g e a r e shown i n F i g 9a and 9b r e s p e c t i v e l y , d e c o n v o l u t e d as d e s c r i b e d p r e v i o u s l y . 5. At 350°C, w i t h f a s t pumping, the d e c o m p o s i t i o n p r o d u c t s were S 2 N 2 , N 2 , S„N 2, S 2, and S 3 N 3 . The amount of S 3 N 3 d e c r e a s e d w i t h a r e d u c t i o n i n pumping e f f i c i e n c y . 6. At 450°C, the main p r o d u c t s were S 2 N 2 , S 2 and N 2. These r e s u l t s a re summarized i n F i g 10. 5.4 D i s c u s s i o n A. P y r o l y s i s w i t h s i l v e r wool The time dependence of the c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s ( F i g 5) c l e a r l y d emonstrates the c a t a l y t i c e f f e c t of s i l v e r s u l f i d e . A steady s t a t e i s e s t a b l i s h e d as soon as enough s i l v e r s u l f i d e has been formed. S 2 N 2 ( w i t h a t r a c e of S 3 N 3 and Si,N ft) i s the o n l y s p e c i e s formed at t h i s s tage whereas a 146 '(b) 4 (a) 4 J (b) 3 \ i ( J (a) 3 (b) 2 • i . 1A I • (a) 2 (b) 1 . . » 1 A. . A l (a) 1 (b) L J i . . . j j j j . (a) ¥ 1 50 150 amu 10 14 eV Fig. 9 Thp. pyrolysis products of over Pyrex wool at 280*0 (a) The Hel PE spectrum of the product mixture (h) The HI. PIM spectrum of the product mixture Each spectrum is deconvoluted to the corresponding parts of i t s constituents: 1. S 3 N 3 2. S 4 N 2 3. S 2 N £ 4. N0 (cannot be ionized by HL „ ) 2 a By Relative partial pressure Fig. 10 The temperature dependence of the composition of the pyrolysis products of S^N^ over Pyrex wool - P i 1 48 c o n s i d e r a b l e amount of N 2 i s produced i n i t i a l l y . These r e s u l t s c o n f i r m the r e a c t i o n s proposed i n the 1 i t e r a t u r e ( 2 8 , 2 9 ) : S«N«(g) + 8Ag(s) A > 4 A g 2 S ( s ) + 2N 2(g) S,N,(g) + A g 2 S ( s ) 2 S 2 N 2 ( g ) + A g 2 S ( s ) The p y r o l y s i s t e m p e r a t u r e has been r e p o r t e d between 130°C(30) and 325°C(19). Maximum y i e l d of S 2 N 2 has been r e p o r t e d f o r 135°C(30), judged by the subsequent y i e l d of the (SN) X polymer. The temp e r a t u r e used here was 250-260°C. Lowering the temperature t o 160°C a f t e r e s t a b l i s h i n g the steady s t a t e y i e l d s a p p r e c i a b l e S 3 N 3 and s m a l l amounts of u n r e a c t e d SflNj,, i n a d d i t i o n t o S 2 N 2 . T h i s i n d i c a t e s t h a t the 'maximum y i e l d ' a t 135°C does not a c t u a l l y r e f e r o n l y t o the S 2 N 2 v a p o r , but a l s o a l l s p e c i e s l e a d i n g t o the (SN) X polymer. The S 3 N 3 vapor c e r t a i n l y a l s o p a r t i c i p a t e s i n t h i s r e a c t i o n and the subsequent f o r m a t i o n of. the polymer. P a s s i n g the S 2 N 2 vapor through Pyrex wool up t o 300°C does not cause n o t i c e a b l e changes i n p r o d u c t s , d e m o n s t r a t i n g , the t h e r m a l s t a b i l i t y of the S 2 N 2 v a p o r . However, warming the b l u e f i l m formed by the c o n d e n s a t i o n of S 2 N 2 vapor g i v e s S 2 N 2 , S f lN 2, S 3 N 3 and S„N a. T h i s s u g g e s t s t h a t s i g n i f i c a n t rearrangement must be i n v o l v e d i n the condensed phase of S 2 N 2 . B. P y r o l y s i s w i t h Pyrex wool The t h e r m a l d e c o m p o s i t i o n of SaN„ vapor over Pyrex wool i s q u i t e s i m i l a r t o t h a t over s i l v e r wool except t h a t use of the l a t t e r a v o i d s the f o r m a t i o n of any s u l f u r - r i c h s p e c i e s , such as S a N 2 and S 2. A l s o , the s i l v e r s u l f i d e l o w e r s the a c t i v a t i o n 1 49 energy f o r the f r a g m e n t a t i o n of S„N„ t o S 2 N 2 . Thus a t temp e r a t u r e s lower than 240°C, most of the S i , N „ vapor s u r v i v e s u n r e a c t e d t h r o u g h the Pyrex w o o l . The major d e c o m p o s i t i o n p r o d u c t i s o n l y S 3 N 3 . S„N 2, N 2 and S 2 N 2 become i m p o r t a n t s p e c i e s a t h i g h e r t e m p e r a t u r e s . At 350-450°C, S 2 N 2 , N 2 and S 2 a r e the major p r o d u c t s . The s i m p l e s t s u l f u r n i t r i d e , S N , which has been s t u d i e d by Hel PE s p e c t r o s c o p y ( 3 1 ) , cannot be i d e n t i f i e d as a p y r o l y s i s p r o d u c t i n t h i s r e a c t i o n under our c o n d i t i o n s , a l t h o u g h t i t s e x i s t e n c e has been r e p o r t e d by a mass s p e c t r o m e t r i c s t u d y ( 2 0 ) . The f a c t t h a t a p r e v i o u s p y r o l y s i s of the S,N„ vapor over Pyrex wool a t 275°C produced the ( S N ) * p o l y m e r ( 2 l ) i s c o n s i s t e n t w i t h our r e s u l t s . Around t h a t t e m p e r a t u r e , most of the S«N„ vapor decomposes i n t o S 2 N 2 , S„N 2 and S 3 N 3 ( F i g 9 ) . S„N 2 i s a v o l a t i l e s p e c i e s and does not undergo any p o l y m e r i z a t i o n a t room t e m p e r a t u r e . Hence the s p e c i e s l e a d i n g t o the f o r m a t i o n of the (SN) S polymer a r e the S 2 N 2 and S 3 N 3 v a p o r s . T h i s i s c o n s i s t e n t w i t h the p y r o l y s i s r e s u l t s o b t a i n e d u s i n g s i l v e r w ool. 5.5 C o n c l u s i o n SflN,, and i t s major p y r o l y s i s p r o d u c t S 2 N 2 have been i n v e s t i g a t e d w i t h the PES/PIMS system. The gaseous s p e c i e s formed from the p y r o l y s i s of the S,Nft vapor w i t h s i l v e r and Pyrex wool have been thus i d e n t i f i e d by the Hel PE s p e c t r a and the HLo07 s p e c t r a d e c o n v o l u t e d w i t h t h e spectrum s t r i p p i n g p r o c e d u r e . S 2 N 2 , S„N 2 and S 3 N 3 are the major s u l f u r n i t r i d e s i n v o l v e d i n t h i s system. C o n d e n s a t i o n of the S 2 N 2 and S 3 N 3 150 vapors l e a d s t o the u l t i m a t e f o r m a t i o n of the (SN) X polymer. The e f f e c t of the s i l v e r wool i s t o pr e v e n t the f o r m a t i o n of any s u l f u r - r i c h s p e c i e s , such as S a N 2 and S 2. The s i l v e r s u l f i d e formed i n the r e a c t i o n between S„N„ and the s i l v e r wool a c t s as c a t a l y s t f o r the f r a g m e n t a t i o n of S«N|, t o S 2 N 2 . The e x i s t e n c e of a new d i s c r e t e s p e c i e s , S 3 N 3 , has been e s t a b l i s h e d by t h i s s t u d y . I t s inv o l v e m e n t i n the f o r m a t i o n of (SN) X p r o v i d e s an im p o r t a n t c l u e f o r s t u d y i n g the v a p o r i z a t i o n of t h i s p o l y m e r ( C h a p t e r 7 ) . 151 R e f e r e n c e s (Chapter 5) 1. H.G. H e a l , Adv. I n o r g . Chem. Radiochem., 15(1972)375. 2. H.G. H e a l , 'The i n o r g a n i c h e t e r o c y c l i c c h e m i s t r y of s u l f u r , n i t r o g e n and phosphorus', Academic P r e s s , London(1980)115. 3. H.W. Roesky, Adv. I n o r g . Chem. Radiochem., 22(1979)239. 4. G.S. Lu and J . Donohue, J . Am.Chem. S o c , 6 6 ( 1 9 4 4 ) 8 1 8 . 5. B.D. Sharma and J . 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Saran, A.G. MacDiarmid, A.F. G a r i t o and A . J . Heeger, J . Am. Chem. S o c , 97(1975) 152 6358. 19. G.B. S t r e e t and R.L. Green, IBM J . Res. Develop., 21(1977) 99. 20. R.D. Sm i t h , J . Chem. S o c , D a l t o n T r a n s . , (1979)478. 21. E . J . L o u i s , A.G. MacDiarmid, A.F. G a r i t o and A.G. Heeger, J . Chem. S o c , Chem. Commun., (1976)426. 22. R.D. Sm i t h , J.R. Wyatt, J . J . De Corpo, F.E. S a a l f e l d , M.J. Moran and A.G. MacDiarmid, J . Am. Chem. S o c , 99(1977) 1726. 23. A.G. MacDiarmid, C M . M i k u l s k i , P . J . Russo, M.S. S a r a n , A.F. G a r i t o and A . J . Heeger, J . Chem. S o c , Chem. Commun., (1975)476. 24. D.C. F r o s t , M.R.LeGeyt, N.L. Paddock and N.P.C. Westwood, J . Chem. S o c , Chem. Commun., (1977)217. 25. J . Sharma, D.S. Downs, Z. I q b a l and F . J . Owens, J . Chem. Phys., 67(1977)3045. 26. W. von N i e s s e n and G.H.F. D i e r c k s e n , J . E l e c t r o n S p e c t r o s c . R e l a t . Phenom.,13(1978)91. 27. I.S. B u t l e r and T. Sawai, Can. J . Chem., 55(1977)3838. 28. C. Hsu and M.M. Labes, J . Chem. Phys., 61(1974)4640. 29. R.L. P a t t o n , Ph. D. T h e s i s , UC B e r k e l e y , 1969. 30. A. D o u i l l a r d , J .F. May and G. V a l l e t , Ann. Chim., 6(1971) 259. 31. J.M. Dyke, A. M o r r i s and I.R. T r i c k l e , J . Chem. S o c , Faraday T r a n s . 2, 73(1977)147. 32. M.M. Labes, P. Love and L.F. N i c h o l s , Chem. Rev.,79(1979)1. 153 Chapter 6 T e t r a s u l f u r D i n i t r i d e SnN 2 6. 1 I n t r o d u c t i o n S„N 2 was f i r s t i s o l a t e d ( i n an impure s t a t e ) i n 1896(1), but the m o l e c u l a r f o r m u l a was o n l y known a f t e r the d e t e r m i n a t i o n of i t s m o l e c u l a r weight i n 1951(2). I t forms opaque, red-grey n e e d l e s which melt a t 23°C t o a dark r e d l i q u i d ( 3 ) . I t decomposes i n a few hours a t room t e m p e r a t u r e , d e c o m p o s i t i o n becoming e x p l o s i v e a t 100°C(3). The compound d i s s o l v e s r e a d i l y i n many o r g a n i c s o l v e n t s such as CS 2, benzene, and hexane(2,4,5), and i t i s much more s t a b l e i n s o l u t i o n ( 6 ) . I t s d i p o l e moment, 1 "N NMR spectrum, mass spectrum, i r spectrum, e l e c t r o n i c spectrum, Raman s p e c t r u m ( 4 ) , and 1 5 N NMR spectrum(7) have been d e t e r m i n e d . These d a t a a l l suggest t h a t t h i s m o l e c u l e i s a six-membered r i n g w i t h the n i t r o g e n atoms i n the 1,3 p o s i t i o n s . L i m i t e d t h e o r e t i c a l s t u d i e s of t h i s s t r u c t u r e have been done. The use of H u c k e l and a r o m a t i c i t y (as a lOtr e l e c t r o n system) arguments (8,9) have i n d i c a t e d a p i anar C 2 v s t r u c t u r e , but an a l t e r n a t i v e boat (or c h a i r ) form (C s symmetry) has been s u g g e s t e d ( 1 0 ) . On the o t h e r hand, an CNDO/2 study suggests a p l a n a r C 2 V s t r u c t u r e ( 1 1 ) , whereas MINDO/3 c a l c u l a t i o n s p r e d i c t a n o n - p l a n a r s t r u c t u r e w i t h no symmetry(12). The compound can be p r e p a r e d by s e v e r a l r o u t e s ( l 3 ) : 1. H e a t i n g S,N„ w i t h s u l f u r i n CS 2 a t 120°C i n an a u t o c l a v e . 2. R e a c t i n g H g 5 ( S N ) B w i t h S 2 C 1 2 i n CS 2. 3. R e a c t i o n of S 2 C 1 2 w i t h aqueous ammonia. 4. R e d u c t i o n of (S„N 3)C1 w i t h m e t a l l i c z i n c . 1 54 5. T r e a t i n g S 7NH w i t h S 3 N 3 C 1 3 i n benzene a t 80°C i n the presence of p y r i d i n e . 6. D e c o m p o s i t i o n of H g ( S 7 N ) 2 a t room t e m p e r a t u r e . The r e a c t i o n s of S a N 2 w i t h o t h e r c h e m i c a l s have not been e x t e n s i v e l y i n v e s t i g a t e d . H y d r o l y s i s c o n v e r t s a l l the n i t r o g e n i n S«,N 2 i n t o ammonia ( 2 , 5 ) . I t does not r e a c t w i t h B C 1 3 i n C S 2 s o l u t i o n a t room t e m p e r a t u r e ( 1 4 ) ; however, i t forms a 1:1 adduct w i t h d i c y c l o p e n t a d i e n e ( 1 5 ) . I t can be o x i d i z e d by S b C l 5 , g i v i n g S4N„-SbCl 5; r e a c t i o n w i t h c h l o r i n e g i v e s S„N 4, S « N 3 + C 1 " and S 6 N 0 2 + ( C 1 " ) 2 ( 1 4 ) . R e d u c t i o n w i t h hydrogen and p a l l a d i u m produces a m i x t u r e of c y c l i c s u l f u r i m ides w i t h eight-membered r i n g s ( 1 4 ) , but s u l f u r and ammonia are the p r o d u c t s of the r e d u c t i o n by HI i n anhydrous f o r m i c a c i d ( 5 ) . T h i s c h a p t e r d e s c r i b e s t h e Hel PE spectrum and t h e PIM s p e c t r a of S(,N 2. I t s t h e r m a l s t a b i l i t y has been i n v e s t i g a t e d by the p y r o l y s i s of the vapor en r o u t e t o the - s p e c t r o m e t e r . The geo m e t r i c and e l e c t r o n i c s t r u c t u r e s of the m o l e c u l e have been s t u d i e d u s i n g ab i n i t i o c a l c u l a t i o n s ( 1 6 ) . ( P r e l i m i n a r y g e o m e t r i c and e l e c t r o n i c s t r u c t u r e c a l c u l a t i o n s were performed i n t h i s l a b o r a t o r y ; the r e f i n e d r e s u l t s d e s c r i b e d here were conducted i n c o l l a b o r a t i o n w i t h M.H. Palmer of the U n i v e r s i t y of Edinburgh.) 6.2 E x p e r i m e n t a l The p r e p a r a t i o n of t h i s compound, an u n s t a b l e r e d o i l , i s not easy and was a c h i e v e d by the the r m a l d e c o m p o s i t i o n of 1 5 5 H g ( S 7 N ) 2 ( l 7 ) d i r e c t l y i n t o the i o n i z a t i o n chamber of the PE s p e c t r o m e t e r . H g ( S 7 N ) 2 was p r e p a r e d by the r e a c t i o n of a methanol s o l u t i o n of S 7NH w i t h m e r c u r y ( I I ) a c e t a t e ( l 7 ) . The p r e c i p i t a t e was f i l t e r e d , washed and d r i e d i n vacuo, where i t was m a i n t a i n e d a t 0°C t o p r e v e n t d e c o m p o s i t i o n . T h i s sample was p l a c e d on l i n e t o the PE s p e c t r o m e t e r and a l l o w e d t o warm. The gas phase p r o d u c t s from the subsequent d e c o m p o s i t i o n were m o n i t o r e d w i t h the PE/PIM s p e c t r o m e t e r and found t o c o n s i s t of m a i n l y S„N 2 and S 2 N 2 , the l a t t e r i d e n t i f i e d by i t s PE and PIM s p e c t r a (Chapter 5 ) . In a second e x p e r i m e n t , the gaseous m i x t u r e was t r a p p e d a t -78°C en r o u t e i n t o the s p e c t r o m e t e r , and by warming s l o w l y t o -15°C S 2 N 2 c o u l d be p r e f e r e n t i a l l y v a p o r i z e d . By c a r e f u l l y c o n t r o l l i n g the c o n d i t i o n s and by s e v e r a l t r a p - t o - t r a p p u r i f i c a t i o n s a l l S 2 N 2 c o u l d be e l i m i n a t e d l e a v i n g dark r e d needle shaped c r y s t a l s below 0°C. T h i s s p e c i e s m e l t e d a t about 20°C. The vapor was p y r o l y z e d a t about 4cm from the i o n i z a t i o n p o i n t . The ab i n i t i o c a l c u l a t i o n s were performed u s i n g a l i n e a r c o m b i n a t i o n of G a u s s i a n b a s i s f u n c t i o n s . Two main bases were used: 1. A medium s i z e minimum b a s i s N ( 7 s 3 p ) , S ( l 0 s 6 p 1 d ) s c a l e d t o o p t i m i z e exponents i n the SN b o n d ( l 8 ) . 2. A c o n t r a c t i o n of the N(9s5p) and S ( 1 2 s 9 p l d ) b a s e s d 9 ) of Dunning(20) and V e i l l a r d ( 2 ! ) . 1 56 6.3 R e s u l t s The i d e n t i f i c a t i o n of the s p e c i e s as pure S,N 2 r e s t s on the o b s e r v e d p h y s i c a l p r o p e r t i e s , e.g. m.p. , and the mass s p e c t r a r e c o r d e d under the same c o n d i t i o n s as the PE spectrum. F i g . 1a, b and c show the PIM s p e c t r a of the vapor above the dark r e d c r y s t a l s r e c o r d e d u s i n g H e l , HLo^r and f i l t e r e d HLa r a d i a t i o n , r e s p e c t i v e l y , as the p h o t o i o n i z a t i o n s o u r c e s . The Hel mass spectrum ( F i g . l a ) shows a s m a l l p a r e n t S„N 2 + peak p l u s S 3 N + , S 2 N 2 + , S 2 N + , S 2 + , and SN + fragments. The u n f i l t e r e d ULapr mass spectrum ( F i g . 1b) i s s i m p l e r , g i v i n g a dominant p a r e n t peak f o r S„N 2 + and major fragment peaks a t t r i b u t a b l e t o S 3N + and S 2 N + . The s m a l l peaks w i t h m/e v a l u e s of 92 ( S 2 N 2 + ) and 46 (SN +) may a r i s e from t r a c e amounts of S 2 N 2 . These l a t t e r peaks v a r y i n i n t e n s i t y w i t h r e s p e c t t o the major t h r e e peaks, and p r o v i d e an assessment of the e x t e n t of S 2 N 2 c o n t a m i n a t i o n . They, however, never e n t i r e l y d i s a p p e a r , and so may be minor fragments from S,N 2 + i t s e l f . F i g . , 1c shows the mass spectrum r e c o r d e d w i t h f i l t e r e d HLo r a d i a t i o n ( 1 0 . 2 e V ) , and here o n l y the t h r e e major peaks a r e o b s e r v e d . No peaks t o h i g h e r m/e were ob s e r v e d at any t i m e . The p r e s e n t r e s u l t s e s s e n t i a l l y agree w i t h the e a r l i e r mass s p e c t r o s c o p i c study ( 4 ) . The Hel PE spectrum i s shown i n F i g . 2 and the e x p e r i m e n t a l I P ' s a r e t a b u l a t e d i n T a b l e 1. The f i r s t two d i s t i n c t peaks at 8.58 and 9.38eV i n the PE spectrum, t o g e t h e r w i t h the PIM d a t a , c h a r a c t e r i z e t h i s s p e c i e s and s e r v e as a good r e f e r e n c e f o r the d e c o n v o l u t i o n p r o c e d u r e s d e s c r i b e d i n Chapter 5. T57 S4 N2 f S,N+ j 1(c) . J L •)(h) * • i l l L 1 (a) V* S + 1 JL i J L 0 40 80 120 160 amu Fig- 1 The PIM spectra of S^ N recorded with (a) Hel, (b) HL  and (c) HL radiation. 159 TABLE 1 Experimental and theoretical I P ' s of S^ N O r b i t a l Exptl T P ' s ThpnrPt.ir.al T P ' s symmetry TVmr.1 p-7Pta CNT)f)/? 15a" 8.58 ± 0.02 8.61 11.10 24a' 9.38 ± 0.02 9.44 11.55 14a" 10.72 ± 0.05 11.96 13.77 23a' 11.1 ± 0.1 13.06 12.86 22a' 12.1 ± 0.1 13.96 14.30 21a' 12.50 ± 0.03 14.16 15.86 13a" 13.23 ± 0.03 14.32 15.28 12a" 14.5 ± 0.1 14.87 16.76 20a' 15.5 ± 0.1 17.48 18.35 19a' 16.8 ± 0.1 17.97 19.80 18a' 17.47 ± 0.05 18.81 20.79 11a" 20.21 18.71 a. All values in eV. 1 60 The m o l e c u l a r geometry was f u l l y o p t i m i z e d by the HONDO program (see Ref. 16) assuming two forms of symmetry, C 2 V and C s. The f i n a l s t r u c t u r e s a r e shown i n F i g . 3 and the energy r e s u l t s a re summarized i n T a b l e 2. The o r b i t a l e n e r g i e s of the o p t i m i z e d C s s t r u c t u r e w i t h a d o u b l e - z e t a b a s i s s e t a r e l i s t e d i n T a b l e 1 t o g e t h e r w i t h the e x p e r i m e n t a l I P ' s . The r e s u l t s of CNDO/2 c a l c u l a t i o n s are a l s o shown f o r comparison w i t h the ab i n i t i o r e s u l t s . The t h e r m a l s t a b i l i t y of the vapor i s q u i t e h i g h . At 200°C, i t p a r t i a l l y decomposes t o S 2 and S 2 N 2 . No f u r t h e r s u b s t a n t i a l change o c c u r s a t h i g h e r t e m p e r a t u r e s , a l t h o u g h a t 400°C s m a l l amounts of S„N« and S 3 N 3 a r e formed. However, S„N 2 i s s t i l l t he major s p e c i e s . N 2 i s not o b s e r v e d i n a p p r e c i a b l e amounts at any p o i n t . 6.4 P i s r u s s i o n W i t h r e f e r e n c e t o T a b l e 2, the non-planar C s s t r u c t u r e i s the most s t a b l e by about 60kJ/mol; f i v e of the atoms are n e a r l y c o - p l a n a r , w i t h o n l y the para-S atom(S5 i n F i g . 3) markedly away from the p l a n e . T h i s i s i n good agreement w i t h the p r e d i c t i o n of J o l l y ( I O ) , and s u g g e s t s t h a t a r o m a t i c i t y i s not p r e s e n t i n S«N 2. Indeed i t can be argued t h a t f o r C 2 V symmetry the d i s t i n c t i o n between 4n and (4n+2)n e l e c t r o n systems i s not f u n d a m e n t a l , s i n c e the H i i c k e l r u l e i s based upon Hund's r u l e of maximum m u l t i p l i c i t y c o u p l e d w i t h the p r e s e n c e of degenerate l e v e l s i n the c y c l i c h y d r o c arbons f o r which i t i s n o r m a l l y i n v o k e d . There are no degenerate l e v e l s i n C 2 V m o l e c u l e s . TABLE 2 Results of the geometry optimization for S^ N^ , a comparison of the and structures c 9 C a 2v s Total energy (AU) -1698.8251 -1698.8301 Virial theorem 1.9999 1.9994 Dipole moment (Debye) 0.560 0.823 Atomic populations S 2 a 15.5054 15.5047 S 4/6 15.8554 15.8637 S 5 16.0719 16.0388 N 1/3 7.3568 7.3646 a. The C„ and C structures are shown in Fig. 3. 2v s 2 5 Fig . 3 The ab i n i t i o optimized C„ and C structures of S.N„ — a c 2v s — 4—2 ro 1 63 A f t e r the p r e s e n t work had been f i n i s h e d , an account of some ' low temperature X-ray c r y s t a l l o g r a p h i c work on S„N 2 was p u b l i s h e d ( 2 2 ) . The r e s u l t s agree v e r y w e l l w i t h the o p t i m i z e d s t r u c t u r e found h e r e , and the s e t s of geo m e t r i c parameters are l i s t e d and compared i n Table 3. C o n v e r s i o n of the d e l o c a l i z e d MO's t o a l o c a l i z e d o r b i t a l system(23) y i e l d s a bonding system of c l a s s i c a l t y p e ( F i g . 4) w i t h the t h r e e c o n t i g u o u s s u l f u r atoms each p o s s e s s i n g normal c o v a l e n t c bonds and two lone p a i r s . The n i t r o g e n atoms a r e each doubl y bound t o the s i n g l e s u l f u r c e n t r e and each of these t h r e e has a s i n g l e l o n e p a i r . The m o l e c u l e i s found t o have a h i g h l y p o l a r i z e d s t r u c t u r e . The c a l c u l a t e d d i p o l e moment i s 0.823 Debye, comparable w i t h the e x p e r i m e n t a l d i p o l e moment of S„N 2 i n CS 2 s o l u t i o n , 1.74 Debye(4). The S3d ( s u l f u r ' s 3d) o r b i t a l p o p u l a t i o n s a r e never h i g h , b e a r i n g i n mind t h a t the s i x S3d c a r t e s i a n f u n c t i o n s i m p l i c i t l y i n c l u d e a f u r t h e r 3s o r b i t a l t o g e t h e r w i t h the u s u a l f i v e ' c h e m i c a l ' S3d o r b i t a l s . T o t a l S3d p o p u l a t i o n s a r e S2 0.7330 S4/S6 0.4784 S5 0.4364 e l e c t r o n s ( l a b e l s r e f e r t o F i g . 3 ) . The h i g h e r v a l u e a t S2 i s c o n s i s t e n t w i t h the c u m u l a t i v e n a t u r e of the bo n d i n g , but i s much lower than might be e x p e c t e d on spd h y b r i d i z a t i o n grounds. The e x c e s s charge on each n i t r o g e n atom i s c a l c u l a t e d t o be 0.3646 e l e c t r o n s . The c o r r e s p o n d i n g v a l u e s f o r S 2 N 2 and S„N a 164 TABLE 3 The molecular geometry of S^ N^  by ab initio calculations  and X-ray crystallography Geometric optimized by ab initio X-ray crystallography^ parameters calculaitons Nl - S2 1.571 1.561 Nl - S6 1.724 1.676 S4 - S5 2.112 2.061 ZN1S2N3 123.3 122.9 ZS2N3S4 126.6 126.7 ZN3S4S5 103.4 103.4 ZS4S5S6 101.1 102.9 a 1.3 0 8 123.1 125.1 a. Refer to Fig. 3. (All bond-lengths are in A) b. Ref. 22. 165 Fig. 4 The electronic structure of S.N 1 66 are 0.6852 and 0.8036 e l e c t r o n s r e s p e c t i v e l y ( 2 3 ) . T h i s t r e n d i s c o n s i s t e n t w i t h the r e l a t i v e b a s i c i t y of the s e t h r e e s p e c i e s , S 0N 2 <S 2N 2<S i,N l l, demonstrated by t h e i r r e a c t i v i t y w i t h Lewis a c i d s , e.g. BF 3 ( 1 4 ) . The v a l e n c e o r b i t a l e n e r g i e s ( T a b l e 1) c a l c u l a t e d by the ab i n i t i o and the CNDO/2 methods can be c l e a r l y grouped i n t o t h r e e r e g i o n s . The f i r s t group c o n s i s t s of the two h i g h e s t o c c u p i e d MO's, 15a" and 24a'. They a r e m a i n l y the a n t i b o n d i n g and bonding c o m b i n a t i o n s of the 3 p z ( t h e x,y p l a n e i s the p l a n e c o n t a i n i n g f i v e atoms) o r b i t a l s of S4 and S6 r e s p e c t i v e l y . The 15a" o r b i t a l a l s o has some i r * c h a r a c t e r r e f e r r i n g t o the S4 and S6 atoms w i t h t h e i r a d j a c e n t n i t r o g e n atoms. These two o r b i t a l s a r e a s s i g n e d t o the f i r s t two PE bands a t 8.58 and 9.38 eV r e s p e c t i v e l y . The second group b e g i n s a t about 2.5eV b e h i n d the f i r s t group (8.61 and 9.44eV) and extend s t o about 15eV (see the ab i n i t i o r e s u l t s i n T a b l e 1 ) . The o r b i t a l s i n t h i s group, 14a", 23a', 22a', 21a', 13a" and 12a", a r e m a i n l y nonbonding or weakly bonding i n c h a r a c t e r . One t o one assignments of t h e s e o r b i t a l s t o s p e c i f i c e x p e r i m e n t a l I P ' s i s not as easy as. f o r the f i r s t group. However, th e s e s i x o r b i t a l s a r e t e n t a t i v e l y a s s i g n e d t o the f o u r PE bands i n the 10-I5ev r e g i o n , as shown i n Tabl e 1. The l a s t group c o n t a i n s f o u r tr or * bonding o r b i t a l s , 20a', 19a', 18a' and 11a", and i s a s s i g n e d t o the broad band a t 15-l8eV. The r e d c o l o r of the compound and i t s weak e l e c t r o n i c a b s o r p t i o n band a t about 450nm (4) suggest a low l y i n g u n occupied o r b i t a l . Both CNDO/2 and ab i n i t i o c a l c u l a t i o n s show 167 t h i s s h o u l d be the n* o r b i t a l of the NSN u n i t . T h i s unoccupied o r b i t a l may induce a Koopmans' breakdown as w e l l as i n c u r some shake-up s a t e l l i t e s , as observed i n the case of S 2 N 2 ( 2 4 ) . T h i s argument has been c o n f i r m e d by a p r e l i m i n a r y Green's f u n c t i o n s t u d y of t h i s s p e c i e s which shows s a t e l l i t e s i n the Hel r e g i o n (25) . In an analogous f a s h i o n t o S 2 N 2 , S«N 2 i s much more s t a b l e i n the vapor phase than i n the condensed phase. The r e s u l t s of the gas phase p y r o l y s i s suggest the d e c o m p o s i t i o n t o be S„N 2 - j - v S 2 N 2 + S 2 The p r o d u c t S 2 N 2 may undergo o t h e r r e a c t i o n s and i n t r o d u c e o t h e r i m p u r i t i e s such as S 3 N 3 and S^ N,,. The t h e r m a l d e c o m p o s i t i o n i n the condensed phase i s p r o b a b l y not through a u n i - m o l e c u l a r r e a c t i o n . 6.5 C o n c l u s i o n S»N 2 has been s y n t h e s i z e d and i s o l a t e d i n a r e l a t i v e l y s i m p l e way, and i d e n t i f i e d by i t s PIM and PE s p e c t r a , which were a l s o used t o c l a r i f y the c o m p o s i t i o n of the p y r o l y s i s p r o d u c t s of the S«N(, vapor over Pyrex wool (Chapter 5 ) . S„N 2 i s one component i n t h a t r e a c t i o n . The vapor phase of the compound i s r e l a t i v e l y t h e r m a l l y s t a b l e i n c o n t r a s t t o i t s i n s t a b l i l i t y i n the condensed phase. The m o l e c u l a r s t r u c t u r e of S,N 2 has been f u l l y o p t i m i z e d by ab i n i t i o c a l c u l a t i o n s and i s shown t o i n v o l v e a C s non-planar form, a f a c t s u p p o r t e d by a r e c e n t X-ray c r y s t a l l o g r a p h i c s t u d y . The e l e c t r o n i c s t r u c t u r e of the m o l e c u l e has been s t u d i e d by i t s 168 Hel PE spectrum, ab i n i t i o and CNDO/2 c a l c u l a t i o n s . The excess charge donated from the s u l f u r atoms t o each n i t r o g e n atom i s l e s s than t h a t f o r S 2 N 2 and S f lN„, which a c c o u n t s f o r the low b a s i c i t y of S„N 2. 169 R e f e r e n c e s (Chapter 6) 1. W. Muthmann and A. C l e v e r , Z. Anorg. A l l g . Chem., 13(1897) 200. 2. A. Meuwen-, Z. Anorg. A l l g . Chem., 266(1951)251. 3. M. Becke-Goehring, P r o g . I n o r g . Chem., 1(1959)207. 4. J . N e l s o n and H.G. H e a l , J . Chem. Soc. A, (1971)136. 5. M. G o e h r i n g , H. Herb and H. Wi s s e m e i e r , Z. Anorg. A l l g . Chem., 267(1952)238. 6. H.G. H e a l , 'The i n o r g a n i c h e t e r o c y c l i c c h e m i s t r y of s u l f u r , n i t r o g e n and phosphorus', Academic P r e s s , London(1980)115. 7. T. C h i v e r s , R.T. O a k l e y , O.J. S c h e r e r and G. Wolmershauser, I n o r g . Chem., 20(1981)914. 8. A . J . B a n i s t e r , N a t u r e , 237(1972)92. 9. H.W. Roesky, Angew. Chem., I n t . Ed. E n g l . , 18(1979)91. 10. W.L. J o l l y , ' S u l f u r r e s e a r c h t r e n d s ' , Adv. Chem. S e r . , 110 (1972)92. 11. R.R. A d k i n s and A.G. T u r n e r , J . Am. Chem. S o c , 100(1978) 1383. 12. A.G. T u r n e r , p r i v a t e communication t o N.P.C. Westwood. 13. H.W. Roesky, Adv. I n o r g . Chem. Radiochem., 22(1979)239. 14. H.G. H e a l , Adv. I n o r g . Chem. Radiochem., 15(1972)375. 15. R.R. A d k i n s and A.G. T u r n e r , I n o r g . Chim. a c t a , 25(1977) 233. 16. M.H. Palmer, J.R. Wheeler, R.H. F i n d l a y , N.P.C. Westwood, and W.M. Lau, s u b m i t t e d t o J . M o l . S t r u c t . Theo Chem. 17. H.G. He a l and R.J. Ramsay, J . I n o r g . N u c l . Chem., 37(1975) 170 286. 18. M.H. Palmer, R.H. F i n d l a y , J . Chem. S o c , P e r k i n T r a n s . 2, (1974)1885. 19. M. Redshaw, M.H. Palmer and R.H. F i n d l a y , Z. N a t u r f o r s c h . , T e i l A, 34(1979)220. 20. T. Dunning, J . Chem. Phys., 53(1970)2823. 21. A. V e i l l a r d , Theor. Chim. A c t a , 12(1968)405. 22. T. C h i v e r s , P..W. Codding and R.T. Oa k l e y , J . Chem. S o c , Chem. Commun., (1981)584. 23. R.H. F i n d l a y , M.H. Palmer, A . J . Downs, R.G. E g d e l l and R. Evans,' I n o r g . Chem., 1 9 ( 1 980)1307. 24. W. von N i e s s e n and G.H.F. D i e r c k s e n , J . E l e c t r o n S p e c t r o s c . R e l a t . Phenom., 13(1978)91. 25. J.S. Tse, p r i v a t e c o m u n i c a t i o n t o W.M. Lau. 171 Chapter 7 T r i s u l f u r t r i n i t r i d e S 3N^ 7.1 I n t r o d u c t i o n The (SN) X polymer was f i r s t p r e p a r e d i n 1910 by the p y r o l y s i s of S,Nft vapor over s i l v e r ( l ) . However, g e n e r a l i n t e r e s t i n t h i s polymer was o n l y r e c e n t l y s t i m u l a t e d by the i n v e s t i g a t i o n of i t s m e t a l l i c e l e c t r o n i c p r o p e r t i e s , e s p e c i a l l y the d i s c o v e r y of i t s s u p e r c o n d u c t i v i t y i n 1975(2). Many r e v i e w s have been p u b l i s h e d on t h i s s p e c i e s , the most r e c e n t one by Labes e t a l . i n 1979(3). The b e s t s y n t h e t i c p r o c e d u r e t o p r e p a r e the c r y s t a l l i n e polymer i s v i a the growth of the c o l o r l e s s c r y s t a l s of S 2 N 2 produced by p y r o l y s i s of S,N, th r o u g h s i l v e r w ool. The c r y s t a l s , upon warming, change t o b l u e - b l a c k (an ESR s i g n a l caused by r a d i c a l s p e c i e s i s o b s e r v e d ) , and f i n a l l y the golden l u s t r o u s d i a m a g n e t i c c r y s t a l s of (SN) X form a f t e r some d a y s ( 6 ) . However, o t h e r r e s u l t s i n d i c a t e t h a t d i f f e r e n t i n t e r m e d i a t e s a r e p o s s i b l e . Two examples a r e a dark r e d paramagnetic s o l i d which may be the SN r a d i c a l , and a dark brown s o l i d w i t h a mass s p e c t r o m e t r i c m o l e c u l a r weight of 9 2 ( 7 ) . Both of the s e two s p e c i e s have been r e p o r t e d t o c o e x i s t w i t h S 2 N 2 as p y r o l y s i s p r o d u c t s of S»N« passe d t h r o u g h s i l v e r w o o l ( 7 ) . T h e i r i s o l a t i o n was r e a l i z e d by h i g h vacuum f r a c t i o n a t i o n , and both s p e c i e s p o l y m e r i z e d r a p i d l y t o the gol d e n s o l i d ( 7 ) . More r e c e n t l y , (SN),< powder has a l s o been p r e p a r e d ( l 5 ) by t h e r e a c t i o n of S 3 N 3 C 1 3 , S 3 N 2 C 1 2 or S 3N 2C1 w i t h ( C H 3 ) 3 S i N 3 or NaN 3 i n CH 3CN. However, t h e r e i s no d i r e c t e v i d e n c e t h a t the f o r m a t i o n of the 172 polymer proceeds t h r o u g h the i n t e r m e d i a c y of a six-membered s u l f u r - n i t r o g e n r i n g , a l t h o u g h t h i s may be a r e a s o n a b l e r o u t e . In s h o r t , the pathways l e a d i n g t o the (SN)* polymer are by no means c l e a r l y e s t a b l i s h e d . The polymer i s a b r i g h t golden l u s t r o u s m e t a l l i c s o l i d w hich i n s i n g l e c r y s t a l form c o n s i s t s of h i g h l y o r i e n t e d p a r a l l e l f i b e r b u n d l e s O ) . I t has been proposed t h a t t h e r e a r e two polymorphs of (SN) X , the a and $ f o r m s ( 4 ) . C r y s t a l l o g r a p h i c d a t a ( 4 ) have been r e p o r t e d o n l y f o r the p form, the s t r u c t u r e of w hich i s shown i n F i g . 1. The m o l e c u l a r c h a i n s d e v i a t e from p l a n a r i t y by about 0.17A f o r b oth s u l f u r and n i t r o g e n atoms. The c o n d u c t i v i t y of the s o l i d depends on i t s p u r i t y as w e l l as i t s c r y s t a l u n i f o r m i t y . The c o n d u c t i v i t y , at room t e m p e r a t u r e , of h i g h q u a l i t y c r y s t a l s i s as h i g h as 40000" 1cm~ 1 ( 5 ) . I t i n c r e a s e s by a f a c t o r of 200 t o 250 a t l i q u i d h e l i u m t e m p e r a t u r e ( 3 ) . The t r a n s i t i o n temperature f o r s u p e r c o n d u c t i v i t y i s 0.26K. Another i n t e r e s t i n g p r o p e r t y of t h e polymer i s t h a t i t s u b l i m e s a t about 135°C. A s p e c t r o s c o p i c study of i t s vapor at t h i s r e l a t i v e l y low temperature i s hence a l o g i c a l approach t o probe i t s e l e c t r o n i c p r o p e r t i e s . A mass s p e c t r o m e t r i c study by Smith et a l . ( 8 ) has s u g g ested t h a t the vapor i s an open-chained (SN) t t. However, e l e c t r i c d e f l e c t i o n a n a l y s i s has shown t h a t the " ( S N ) 8 " s p e c i e s i n the vapor i s n o n p o l a r ( 9 ) . On the other hand, an i r and u v - v i s i b l e s p e c t r o s c o p i c s t u d y u s i n g m a t r i x i s o l a t i o n of the vapor has c o n c l u d e d t h a t the major components are S 2 N 2 and the u s u a l c r a d l e form S 8N„, w i t h some o t h e r u n i d e n t i f i e d 173 Fig. 1 The crystal structure of the (SN)^ polymer (Ref. 4) (All bondlengths are in A.) 174 p r o d u c t s ( 1 0 ) . A more r e c e n t mass s p e c t r o m e t r i c study by Smith (11) r e p o r t s t h a t the p y r o l y s i s p r o d u c t s of S,N„ a c t u a l l y c o n t a i n S 2 N 2 , S 3 N 3 and S,N 2 but no open-chained " ( S N ) , " , a l t h o u g h c o n d e n s a t i o n of th e s e s p e c i e s a g a i n l e a d s t o the f o r m a t i o n of the (SN)* polymer. The i n c o n s i s t e n c y among thes e r e s u l t s i n d i c a t e s t h a t more i n v e s t i g a t i o n s on t h i s s u b j e c t a r e r e q u i r e d . The work p r e s e n t e d i n t h i s c h a p t e r p r o v i d e s such a c o n t i n u a t i o n and g i v e s e v i d e n c e f o r the e x i s t e n c e of the p r e v i o u s l y unknown S 3 N 3 m o l e c u l e . No i n f o r m a t i o n c o n c e r n i n g the S 3 N 3 r a d i c a l i s a v a i l a b l e i n the l i t e r a t u r e but S 3 N 3 " i s r e l a t i v e l y well-known. The cesium and t e t r a a l k y l a m m o n i u m s a l t s of t h i s a n i o n have been s y n t h e s i z e d by the r e a c t i o n of the a p p r o p r i a t e a z i d e w i t h S,N„ i n e t h a n o l ( 1 2 ) . The c r y s t a l s t r u c t u r e of n-Bu„N*S 3N 3" has been d e t e r m i n e d by X-ray c r y s t a l l o g r a p h y ( 1 3 ) . The a n i o n i s a six-membered, e s s e n t i a l l y p l a n a r r i n g as shown i n F i g . 2. The e l e c t r o n i c s t r u c t u r e of the a n i o n has been s t u d i e d by ab i n i t i o H a r t r e e - F o c k - S l a t e r SCF c a l c u l a t i o n s ( 1 3 ) and the CNDO/2 l o c a l i z e d MO method(14). In t h i s c h a p t e r , the vapor of t h e (SN) X polymer has been s t u d i e d by i t s Hel PE and PIM s p e c t r a . The r e s u l t s have been c o r r e l a t e d w i t h the r e s u l t s o b t a i n e d from p y r o l y s i s of S 4N, vapor (Chapter 5 ) . The e x i s t e n c e of a d i s c r e t e s p e c i e s , the S 3 N 3 r a d i c a l , i s thus proposed. The s t a b i l i t y of t h i s s p e c i e s i n i t s vapor phase and condensed phase has been i n v e s t i g a t e d . . 2 Structure of the anion (Ref. 13) o (All bond-lengths in A, and a l l angles in degrees) 176 7.2 E x p e r i m e n t a l The a p p a r a t u s used here was s i m i l a r t o t h a t employed i n the p y r o l y s i s e x p e r i m e n t s of Chapter 5, except t h a t a tube w i t h a s m a l l U - t r a p was used i f t r a p p i n g of the vapor was d e s i r e d . The l e n g t h of the sample tube was v a r i e d from 2cm t o 25cm i n o r d e r t o t e s t the v o l a t i l i t y and s t a b i l i t y of the va p o r . The (SN) X polymer was s u p p l i e d by R.T. Oakley of the Department of C h e m i s t r y , U n i v e r s i t y of C a l g a r y . The sample c o n s i s t e d of some golden l u s t r o u s c r y s t a l s each about 15mm3 i n s i z e . 7.3 R e s u l t s A. The s p e c t r a of the vapor The Hel PE spectrum ( F i g . 3) and H e l , Hhafir, and HLo mass s p e c t r a ( F i g . 4a, b, and c) of the vapor were o b t a i n e d when the (SN) X polymer was heated t o 145°C w i t h i n 2cm of the i o n i z a t i o n p o i n t . The s p e c t r a were the same as tho s e d e c o n v o l u t e d from the s p e c t r a of the p y r o l y s i s p r o d u c t s of the S,N„ vapor, and a s s i g n e d t o . the S 3 N 3 r a d i c a l . The vapor p r e s s u r e i n c r e a s e d r a p i d l y w i t h f u r t h e r s m a l l i n c r e a s e s i n t e m p e r a t u r e . The vapor, however, was a b l e t o t r a v e l as f a r as 25cm a l o n g a 5mm tube w i t h o n l y v e r y s m a l l amounts of S,N, and S„N 2, and p o s s i b l y S 2 N 2 as w e l l , as i m p u r i t i e s . The former two s p e c i e s were observed and i d e n t i f i e d by t h e i r p a r e n t peaks i n the HLo^r mass s p e c t r a . IONIZATION POTENTIAL 178 Fig. 4 The PIM spectra of S^N3 recorded with (a) Hel, (b) HL „ and (c) HL radiation ^—^ a By — ot 179 B. Thermal s t a b i l i t y of the vapor The vapor was o b t a i n e d by h e a t i n g the (SN) X polymer a t 145°C, 10cm from t h e i o n i z a t i o n p o i n t . I t was i d e n t i f i e d as pure S 3 N 3 by i t s PE and mass s p e c t r a . The vapor was then p y r o l y z e d over Pyrex wool a t the open end of the sample tube up t o t e m p e r a t u r e s of 450°C. L i t t l e change o c c u r r e d below 300°C. At h i g h e r t e m p e r a t u r e s , S 2 N 2 , s m a l l amounts of S ( N 2 and a t r a c e of S«N, emerged; but S 3 N 3 remained t h e most i m p o r t a n t s p e c i e s up to 350°C. At 450°C, the major gas phase s p e c i e s were S 2, N 2 and S 2 N 2 . C. Condensed phase r e a c t i o n s of the vapor The vapor was o b t a i n e d and i d e n t i f i e d as pure S 3 N 3 by the pr o c e d u r e s d e s c r i b e d p r e v i o u s l y . By m a i n t a i n i n g the same c o n d i t i o n s , i t was then condensed en r o u t e t o the sp e c t r o m e t e r i n a s m a l l t r a p a t l i q u i d n i t r o g e n t e m p e r a t u r e . A f i l m d e v e l o p e d over the c o u r s e of an hour w i t h p e r i p h e r a l hues of r e d , brown, w h i t e and b l u e . The red p o r t i o n was the most v o l a t i l e and p e n e t r a t e d i n t o the t r a p t o a l a r g e r e x t e n t . The f i l m changed t o dark b l u e when warmed up t o room t e m p e r a t u r e . D u r i n g t h i s p r o c e s s , a s e r i e s of H L o p r mass s p e c t r a were o b t a i n e d as shown i n F i g . 5. By h e a t i n g the b l u e f i l m , S 2 N 2 , S 3 N 3 , S ( N 2 and S«Ntt were o b t a i n e d w i t h v a r y i n g c o m p o s i t i o n s , however S j N , was always the l a s t r e s i d u e . 7.4 D i s c u s s i o n The p r e v i o u s l y p u b l i s h e d p r o p o s i t i o n f o r a l i n e a r ( S N ) i , 180 Fig. 5 The HL PIM spectra recorded during the vaporization 181 s p e c i e s as the vapor phase s p e c i e s of the (SN) X polymer r e s t s e s s e n t i a l l y on the e x p e r i m e n t a l r e s u l t s of t h r e e almost i d e n t i c a l papers by the same a u t h o r s ( 8 ) . The e v i d e n c e f o r such a l i n e a r t e t r a m e r i s summarized a s : 1. Phase a n g l e mass s p e c t r o m e t r i c a n a l y s i s i n d i c a t e s t h a t a t l e a s t 85% of t h e fragments o b s e r v e d i n an e l e c t r o n impact mass spectrum descend from a n e u t r a l s p e c i e s h a v i n g a mass of 190 +/- 10. (The next i m p o r t a n t n e u t r a l p a r e n t i s S 3 N 3 w i t h an e s t i m a t e d upper l i m i t of 15% p o p u l a t i o n . ) 2. The f i e l d i o n i z a t i o n mass spectrum shows an e x t r e m e l y s m a l l peak a t 256 amu ( S B + ) i n a d d i t i o n t o a weak peak a t 184 amu and a s t r o n g one a t 138 amu. The f i e l d d e s o r p t i o n mass spectrum c o n t a i n s o n l y a S B* peak w i t h medium i n t e n s i t y , p l u s a s t r o n g peak a t 184 amu. 3. The f i e l d i o n i z a t i o n mass spectrum of the c r a d l e form S„Nfl shows o n l y the m o l e c u l a r i o n S^N,*; but the vapor of the (SN) X polymer shows a fragment a t 138 amu ( S 3 N 3 * ) , i n a d d i t i o n t o s m a l l peaks a t 256 and 184 amu, w i t h about 85% of the i n t e n s i t y of the complete spectrum. For c y c l i c hydrocarbon and h e t e r o c y c l i c compounds, f r a g m e n t a t i o n under f i e l d i o n i z a t i o n c o n d i t i o n s does not appear t o be i m p o r t a n t ( 1 6 ) . The above e v i d e n c e f o r a l i n e a r (SN)» s p e c i e s can however be c o u n t e r e d by s e v e r a l o t h e r p i e c e s of i n f o r m a t i o n a v a i l a b l e i n 1 B2 the l i t e r a t u r e : 1. A m a t r i x i s o l a t i o n study of the vapor (10) c o n c l u d e d t h a t the v a p o r i z a t i o n of the (SN) X polymer a t 140-160°C produces some S 2 N 2 and p o s s i b l y a t r a c e of the SN r a d i c a l but m o s t l y the well-known c r a d l e form S«N« w i t h more than one o t h e r u n i d e n t i f i e d s p e c i e s . Hence the u s u a l S«N, may e x i s t i n the vapor and a c t as a p a r e n t m o l e c u l e g i v i n g a peak a t 184 amu i n the mass spectrum. However, the S 3 N 3 * peak a t 138 amu does not n e c e s s a r i l y d e r i v e from a p a r e n t i o n a t 184 amu s i n c e t h e r e may be o t h e r s p e c i e s p r e s e n t . 2. A m o l e c u l a r beam e l e c t r i c d e f l e c t i o n a n a l y s i s of the vapor s u g g e s t s t h a t the mass peaks a t 184 amu((SN)„*) and 138 amu((SN) 3*) a r e due t o n o n p o l a r n e u t r a l p r e c u r s o r s and t h a t they c o n s t i t u t e 85-95% of the p a r e n t beam(9). S„N 2 i s observed as an i m p o r t a n t s p e c i e s i n t h i s s t u d y . These r e s u l t s show t h a t the vapor phase system may be more c o m p l i c a t e d due t o the presence of s e v e r a l s p e c i e s , and the p r e c u r s o r t o the peak a t 184 amu i s u n l i k e l y t o be an open-chained (SN)« m o l e c u l e . 3. A vapor p r e s s u r e study of the vapor showed t h a t the s m a l l v a p o r i z a t i o n c o e f f i c i e n t (about 2 X10" 3) and the magnitude of the heat of v a p o r i z a t i o n ( 3 0 K c a l / m o l , compared w i t h about 50-60 K c a l / m o l f o r the S-N bond s t r e n g t h ) both suggest t h a t the vapor phase s p e c i e s does not have the open-chained s t r u c t u r e of the s o l i d polymer but r a t h e r i n v o l v e s an e x o t h e r m i c rearrangement such as r i n g format i o n ( 1 7 ) . 183 4. U s i n g the same e x p e r i m e n t a l t e c h n i q u e s as those l e a d i n g t o the f o r m a t i o n of the proposed " ( S N ) , " s p e c i e s , S 3 N 3 has been shown t o be one of the p r o d u c t s i n the p y r o l y s i s of the S„Nft vapor over q u a r t z wool and s i l v e r w o o l ( 1 l ) . No l i n e a r "(SN),," has been o b s e r v e d i n the s e r e a c t i o n s , s i m i l a r t o the r e s u l t s d e s c r i b e d i n t h i s t h e s i s . S i n c e the c o n d e n s a t i o n of these s p e c i e s w i l l e v e n t u a l l y form the (SN) X polymer, and the s u b l i m a t i o n of the polymer a g a i n w i l l g i v e back the polymer i t s e l f , t h e r e may be some c o r r e l a t i o n s between the vapor s u b l i m e d from the polymer and the s p e c i e s produced i n the p y r o l y s i s of the S«N, vap o r . The e x p e r i m e n t a l r e s u l t s of the p r e s e n t PE/PIM study p r o v i d e a d d i t i o n a l e v i d e n c e a g a i n s t the assignment of the vapor phase s p e c i e s of the (SN) X polymer t o a l i n e a r (SN), m o l e c u l e , but i n s t e a d p o i n t t o the S 3 N 3 r a d i c a l . T h i s e v i d e n c e , which i s a l s o , i n g e n e r a l , c o n s i s t e n t w i t h the o t h e r r e s u l t s i n the l i t e r a t u r e , i s p r e s e n t e d below. 1. A d i s t i n c t s i n g l e peak a t 8.62eV i n the 8 - l0.5eV r e g i o n and the g e n e r a l appearance of the Hel PE s p e c t r u m ( F i g . 3) s t r o n g l y s u g g e s t s t h a t the vapor g e n e r a t e d under such c o n d i t i o n s i s a s i n g l e s p e c i e s . The c o r r e s p o n d i n g Hel mass s p e c t r u m ( F i g . 4a) i s v e r y s i m i l a r t o those of S 2 N 2 and S,N a, s u p p o r t i n g the i d e a t h a t t h i s s p e c i e s i s an a g g r e g a t i o n of the (SN) u n i t . The HLopr mass s p e c t r u m ( F i g . 4b) shows a s t r o n g S 3 N j * peak w i t h o t h e r fragments such as S 2N 2*, S 2N*, and SN*. The HLo mass s p e c t r u m ( F i g . 4 c ) , however, g i v e s o n l y a dominant 184 S 3N 3* peak and two s m a l l peaks ( S 2 N 2 * and S 2 N * ) . S i n c e the HLc r a d i a t i o n ( 1 0 . 2 e V ) cannot i o n i z e S 2 N 2 , the S 2N 2* peak i n the HLo mass spectrum i s a fragment of the p a r e n t s p e c i e s but not the pa r e n t i o n of S 2 N 2 . The low i n t e n s i t y of t h i s peak i n the HLc^r mass spectrum s u g g e s t s t h a t S 2 N 2 i s i n f a c t absent i n the vapor. The f a c t t h a t t h e r e a r e no peaks w i t h masses h i g h e r than 138 amu ( S 3 N 3 * ) i n any of the t h r e e mass s p e c t r a p r o v e s t h a t the vapor does not c o n t a i n s any S„N 2 or the c r a d l e form SqN,,. Moreover, the SN r a d i c a l i s not p r e s e n t because a l t h o u g h i t can be i o n i z e d by HLo r a d i a t i o n , SN* i s absent i n the HLo mass spectrum. Hence, i t can be c o n c l u d e d t h a t the vapor g e n e r a t e d under the p r e s e n t c o n d i t i o n s i s a s i n g l e d i s c r e t e s p e c i e s . S i n c e a l l the o t h e r s u l f u r - n i t r o g e n s p e c i e s s t u d i e d i n these c h a p t e r s show t h e i r p a r e n t peaks i n t h e i r H L o i r mass s p e c t r a , t h i s vapor phase s p e c i e s i s thus a s s i g n e d as the S 3 N 3 r a d i c a l . We do n o t e , however, t h a t under v a r y i n g e x p e r i m e n t a l c o n d i t i o n s o t h e r s p e c i e s , p a r t i c u l a r l y S 2 N 2 and S a N 2 , and a l s o S^Na can be produced. T h i s i n i t s e l f can l e a d t o the c o n f u s i o n i n the l i t e r a t u r e . 2. S i n c e the h i g h e s t peak obser v e d i n the HLo mass spectrum i s S 3N 3*, the vapor phase s p e c i e s s h o u l d c o n s i s t of a t l e a s t t h r e e SN u n i t s . However, the Hel PE spectrum shows a r a t h e r s h a r p f i r s t band and the s e p a r a t i o n between t h i s and the second band„is about 2.5eV. Such a d i s t i n c t f i r s t band i s v e r y u n u s u a l f o r a m o l e c u l e h a v i n g a t l e a s t t h r e e s u l f u r and t h r e e n i t r o g e n atoms. For example, w i t h i n 2.5eV of the f i r s t I P , the 185 Hel PE spectrum of S 2 N 2 shows 3 r e s o l v e d bands, t h a t of S„N 2 shows 4 bands, and S,N, shows 6 bands(see a l s o Chapter 5 and 6 ) . A l i n e a r (SN), b i r a d i c a l or a c y c l i c (SN), m o l e c u l e may g i v e more complex i o n i z a t i o n p a t t e r n s . T h i s argument i s s u p p o r t e d by SCF-Xa-SW c a l c u l a t i o n s of a open-chained (SN), m o d e l ( l 8 ) which shows p o s s i b l e i o n i z a t i o n s from two c and two n o r b i t a l s w i t h i n the f i r s t 2eV. 3. I t has been e s t a b l i s h e d by X-ray c r y s t a l l o g r a p h y t h a t the S 3N 3" a n i o n i n n-Bu,N*S 3N 3~ i s a p l a n a r six-membered r i n g ( l 3 ) . I t s s t r u c t u r e i s shown i n F i g . 2. The e l e c t r o n i c s t r u c t u r e has been s t u d i e d by the ab i n i t i o HFS-SCF method, assuming D 3 h symmetry. The c a l c u l a t e d energy of the f i r s t e l e c t r o n i c t r a n s i t i o n (2E" t o 2A 2") p r e d i c t s the u v - a b s o r p t i o n band of t h i s a n i o n a t 360nm e x t r e m e l y w e l l ( 1 3 ) . S i m i l a r c a l c u l a t i o n s have been done f o r the c o r r e s p o n d i n g S 3 N 3 * c a t i o n , a g a i n assuming D 3 h symmetry but w i t h bond l e n g t h s s e t a t 1.55A i n s t e a d of 1.6A(13). The c a l c u l a t e d s e p a r a t i o n between the LCJMO (l o w e s t u n o c c u p i e d MO) and the HOMO ( h i g h e s t o c c u p i e d MO) of the c a t i o n i s 3 . 3 8 e V ( l 9 ) . I t has been shown t h a t t h i s s e p a r a t i o n can be c o r r e l a t e d w i t h the d i f f e r e n c e between the f i r s t and second I P ' s of the c o r r e s p o n d i n g n e u t r a l s p e c i e s ( 2 0 ) , b e a r i n g i n mind the d i f f e r e n c e s between a d i a b a t i c and v e r t i c a l I P ' s . The e x p e r i m e n t a l v a l u e , 2.5eV, a g r e e s r e a s o n a b l y w e l l w i t h the above crude e s t i m a t i o n and p r o v i d e s some su p p o r t f o r the assignment of t h e S 3 N 3 r a d i c a l t o the vapor a r i s i n g from h e a t i n g the (SN) X polymer. 186 4. The vapor phase s p e c i e s can t r a v e l more than 25cm i n a 5mm g l a s s tube w i t h o n l y v e r y minor d e c o m p o s i t i o n . In a d d i t i o n , most of i t s t i l l s u r v i v e s a f t e r passage through Pyrex wool a t 300°C. A b i r a d i c a l such as the l i n e a r " ( S N )," i s u n l i k e l y t o be so s t a b l e . A S 3 N 3 r a d i c a l w i t h a r i n g s t r u c t u r e and some d e r e a l i z a t i o n of the u n p a i r e d e l e c t r o n , however, may posses s such s t a b i l i t y . 5. T h i s S 3 N 3 r a d i c a l has been obse r v e d and i d e n t i f i e d both by i t s PE and mass s p e c t r a from the p y r o l y s i s of S,N, vapor over s i l v e r wool or Pyrex wool; moreover, i t p r o b a b l y a l s o p a r t i c i p a t e s i n the f o r m a t i o n of the (SN) X polymer upon c o n d e n s a t i o n (Chapter 5 ) . These r e s u l t s and the consequent p r o p o s a l a r e c o h e r e n t w i t h the s u b l i m a t i o n p r o p e r t y of the (SN) X polymer, and c o n s i s t e n t w i t h the r e c e n t mass s p e c t r o m e t r i c study of the p y r o l y s i s of the S,Ntt v a p o r ( 1 1 ) . 6. A l t h o u g h t h i s s p e c i e s i s r e l a t i v e l y s t a b l e i n i t s vapor phase, i t undergoes s u b s t a n t i a l changes upon c o n d e n s a t i o n . The f a c t t h a t c o n d e n s a t i o n of a s i n g l e s p e c i e s g i v e s such a spread of c o l o r s as r e d , brown, w h i t e and b l u e i s r e a l l y q u i t e s u r p r i s i n g . However, th e s e c o l o r s have been observed as p r e c u r s o r s t o the (SN) X p r e p a r a t i o n ( 7 ) . Upon warming back t o room t e m p e r a t u r e , S 2 N 2 , S,N 2, and S 3 N 3 emerge s e q u e n t i a l l y from t h i s c o n d e n s a t e ( F i g . 5 ) ; meanwhile, a dark b l u e f i l m d e v e l o p s a t the same p o s i t i o n as the c o l o r f u l s p r e a d . One t o one i d e n t i f i c a t i o n of the c o l o r s i s not p o s s i b l e because vapors 167 d e t e c t e d by the mass s p e c t r o m e t e r may not be the o r i g i n a l condensed m a t e r i a l s s i n c e changes may occur e i t h e r d u r i n g the v a p o r i z a t i o n p r o c e s s or on r o u t e t o the s p e c t r o m e t e r . On the o t h e r hand, warming the dark b l u e f i l m (room temperature t o 90°C) g i v e s S 2 N 2 , S 3 N 3 , S 4 N 2 and S«N«, i n v a r y i n g c o m p o s i t i o n s . I f the dark b l u e f i l m i s kept a t room t e m p e r a t u r e , i t g r a d u a l l y d a r k e n s and g i v e s some gol d e n l u s t r e s u g g e s t i n g t h a t some (SN)* polymer has been formed. T h i s f i l m i s t h u s s i m i l a r t o t h a t formed by co n d e n s i n g S 2 N 2 . T h i s m a t e r i a l i s c e r t a i n l y more r e a c t i v e than the golden polymer, which i s a g a i n c o n s i s t e n t w i t h the ESR r e s u l t s which show t h a t i t c o n t a i n s r a d i c a l s p e c i e s ( 6 ) . 7. The d e g e n e r a t i o n of the S 3 N 3 r a d i c a l a l s o o c c u r s i f the vapor has t o t r a v e l l o n g d i s t a n c e (about 25cm) b e f o r e a r r i v i n g a t t he i o n i z a t i o n r e g i o n . S m a l l amounts of S f tN 2, S„N, and S 2 N 2 appear. The i n s e r t i o n of a Pyrex wool p l u g does not induce any s u b s t a n t i a l change. However, the abundances of the above s p e c i e s i n c r e a s e s i g n i f i c a n t l y w i t h d e c r e a s e i n pumping e f f i c i e n c y . T h i s s u g g e s t s t h a t t h e s e s p e c i e s a re formed by i n t e r m o l e c u l a r c o l l i s i o n s r a t h e r than j u s t by m o l e c u l e - w a l l c o l l i s i o n s . The i n t e r e s t i n g condensed phase r e a c t i o n s a r e p r o b a b l y j u s t e x t e n s i o n s of t h e s e changes. A l t h o u g h the e x p e r i m e n t a l c o n d i t i o n s a r e not e x a c t l y the same, i t i s q u i t e p o s s i b l e t h a t the o t h e r p r e v i o u s s t u d i e s on the vapor of the (SN) X polymer may have been on the r e s u l t s of i n t e r m o l e c u l a r c o l l i s i o n s i n s t e a d . . Hence the m a t r i x study of the vapor showed the e x i s t e n c e of S 2 N 2 and S,N,, and the e l e c t r i c d e f l e c t i o n 188 e x p e r i m e n t s proved t h a t S,N 2 i s an o t h e r i m p o r t a n t s p e c i e s . However, except by c r a c k i n g the vapor over Pyrex wool above 300°C, elementary s u l f u r has never been observed under the p r e s e n t c o n d i t i o n s . Hence, the e x i s t e n c e of l a r g e amount of S B* i n the f i e l d i o n i z a t i o n and f i e l d d e s o r p t i o n mass spectra(8) s u g g e s t s t h a t the p u r i t y of the sample or the c o r r e l a t i o n between t h e s p e c i e s a t the p r o b i n g s i t e of the s p e c t r o m e t e r and the vapor of the (SN)* polymer i s q u i t e q u e s t i o n a b l e . T h i s problem i s p a r t i c u l a r l y s e r i o u s i n case of the f i e l d d e s o r p t i o n mass spectrum because the h e i g h t of the S e* peak i s about 25% of the (SN),* peak. I n c i d e n t a l l y , the sample g i v i n g t h i s spectrum i s p r e p a r e d by s u b l i m i n g the polymer t o the sample probe, and not d i r e c t l y u s i n g the c r y s t a l l i n e polymer i t s e l f . T h i s v a p o r i z a t i o n and c o n d e n s a t i o n p r o c e s s , as shown above and d i s c u s s e d b e f o r e , i s an i m p o r t a n t source of i m p u r i t i e s . However, s i n c e t h e r e i s o n l y one s i n g l e peak of (SN),* b e s i d e s the S B* peak i n the f i e l d d e s o r p t i o n mass spectrum, and we never o b t a i n e d pure S,N, from the vapor (except a t the end of the r e - e v a p o r a t i o n of the condensed v a p o r ) , t o g e t h e r w i t h the f a c t t h a t t h e r e i s an o b v i o u s c o l o r d i f f e r e n c e between the (SN) X polymer and the S,N, s o l i d , a ( S N), s p e c i e s may be r e a l l y formed i n such c o n d i t i o n s . T h i s argument, of c o u r s e , as w e l l as the p r e s e n t p r o p o s a l of the S 3 N 3 r a d i c a l , r e q u i r e s more e x p e r i m e n t a l e v i d e n c e and i n f o r m a t i o n about t h e vapor c o m p o s i t i o n over t h e (SN) X polymer. E x p e r i m e n t s such as MW a n a l y s i s , e l e c t r o n d i f f r a c t i o n and vapor phase ESR measurements, d i f f e r e n t s y n t h e t i c r o u t e s t o the polymer and the S 3 N 3 r a d i c a l , and vapor 189 phase c h e m i c a l r e a c t i o n s of the vapor may be a p p r o p r i a t e . 7.5 f p n r l n g i on The (SN) X polymer i n the vapor phase has been e s t a b l i s h e d t o be a s i n g l e d i s c r e t e s p e c i e s a t about 145°C. The PIM s p e c t r a , t o g e t h e r w i t h the r e s u l t s of the p y r o l y s i s of the S,N, vapor (Chapter 5) and the l i t e r a t u r e ( 1 1 ) demonstrate t h a t t h i s s p e c i e s i s the S 3 N 3 r a d i c a l . The d i s t i n c t f i r s t peak of i t s Hel PE spectrum a t 8.62eV and the l a r g e s e p a r a t i o n between t h i s and the second band (2.5eV) g i v e s t r o n g s u pport t o t h i s p r o p o s a l . The r e l a t i v e l y h i g h t h e r m a l s t a b i l i t y of the vapor and HFS-SCF c a l c u l a t i o n s on the S 3 N 3 c a t i o n i n d i c a t e t h a t the r a d i c a l may have a r i n g s t r u c t u r e . I n t e r m o l e c u l a r r e a c t i o n s , e s p e c i a l l y i n the condensed phase, change the vapor t o a m i x t u r e of S 2 N 2 , S 3 N 3 , S,N 2 and S 0N,. The condensate e v e n t u a l l y forms the l u s t r o u s (SN) X polymer. These u n u s u a l r e a c t i o n s may be one reason f o r the s e r i o u s d i f f e r e n c e s between r e s u l t s of p r e v i o u s s t u d i e s of the va p o r . No o t h e r s p e c i e s g a i n e d enough i n t e n s i t y t o be i d e n t i f i e d by the PE/PIM s p e c t r o m e t e r i n e i t h e r the v a p o r i z a t i o n of the polymer or the i n t e r m o l e c u l a r r e a c t i o n s and t h e r m a l c r a c k i n g of the vapor under our e x p e r i m e n t a l c o n d i t i o n s (except S 2 and N 2 ) . 1 90 R e f e r e n c e s (Chapter 7) 1. F.P. B u r t , J . Chem. S o c , (1910)1171. 2. R.L. Greene, G.B. S t r e e t and L . J . S u t e r , Phys. Rev. L e t t . , 34(1975)577. 3. M.M. Labes, P. Love and L.F. N i c h o l s , Chem. Rev., 79(1979) 1 . 4. M. B o u d e u l l e , C r y s t . S t r u c t . Commun., 4(1975)9. 5. R.L. Greene and G.B. S t r e e t , " Chemistry and p h y s i c s of one d i m e n s i o n a l m e t a l s " , H.J. K e l l e r , ed., Plenum P r e s s , N.Y., (1977)167. 6. M.J. Cohen, A.F. G a r i t o , A . J . Heeger, A.G. MacDiarmid, C M . M i k u l s k i , M.S. Saran and J . K l e p p i n g e r , J . Am. Chem. S o c , 98(1976)3844. 7. P. Love, G. Myer, H.I. Kao, M.M. Labes, W.R. Junker and C. Elbaum, " S y n t h e s i s and p r o p e r t i e s of low d i m e n s i o n a l m a t e r i a l s " , J.S. M i l l e r and A . J . E p s t e i n , ed., Ann. N.Y. Acad. S c i . , 313(1978)745. 8. R.D. S m i t h , J.R. Wyatt, J . J . DeCorpo, F.E. S a a l f e l d , M.J. Moran and A.G. MacDiarmid, Chem. Phys. L e t t . , 41(1976)362? J . Am. Chem. S o c , 99(1977)1726. R.D. Smith, J . J . DeCorpo, J.R. Wyatt and F.E. S a a l f e l d , I n t . J . Mass. Spectrom. Ion Phys., 21(1976)411. 9. R.R. Cavanagh, R.S. Altman, D.R. Herschbach and W. Klem-p e r e r , J . Am. Chem. S o c , 101 ( 1979)4734. 10. R.A. Teichman I I I and E.R. N i x o n , I n o r g . Chem., 15(1976) 1 993. 191 11. R.D. Sm i t h , J . Chem. S o c , D a l t o n T r a n s . , (1979)478. 12. J . B o j e s and T. C h i v e r s , J . Chem. S o c , Chem. Commun., (1977) 453; I n o r g . Chem., 17(1978)318. 13. J . Bo j e s and T. C h i v e r s , J . Chem. S o c , Chem. Commun., (1978) 391. J . B o j e s , T. C h i v e r s , W.G. L a i d l a w and M. T r s i c , J . Am. Chem. S o c , 101 (1979)4517. 14. A.A. B h a t t a c h a r y y a , A. B h a t t a c h a r y y a and A.G. T u r n e r , I n o r g . Chim. A c t a , 45(1980)L13. 15. J . Passmore and M.N. Sudheendra Rao, J . Chem. S o c , Chem. Commun., (1980)1269. 16. H.D. Beckey, " F i e l d I o n i z a t i o n Mass S p e c t r o m e t r y " , P e r g a -mon, N.Y.(1971). 17. D.C. Weber and C.T. Ewing, I n o r g . Chem., 16(1977)3025. 18. D.R. Salah u b and R.P. Messmer, Phys. Rev. B, 14(1976)2592. 19. R.T. O a k l e y , p r i v a t e communication t o N.P.C. Westwood. 20. F.G. H e r r i n g and R.A.N. McLean, I n o r g . Chem., 11(1972) 1667. 1 92 PART 11 IB A study of monomeric n i t r o s o m e t h a n e . i t s c i s and t r a n s d i m e r s , and formaldoxime The PES/PIMS system has been used t o stu d y monomeric n i t r o s o m e t h a n e , the c i s and t r a n s d i m e r s , and formaldoxime. In c o n t r a s t t o e a r l i e r r e s u l t s i t has shown t h a t c i s (CH 3NO) 2 s e q u e n t i a l l y g i v e s CH2=NOH and CH 3NO upon v a p o r i z a t i o n . A PE spectrum of the c i s dimer was not ob s e r v e d . In a d d i t i o n , a p r e v i o u s spectrum of 'monomeric' CH 3NO i s shown t o be l o n g t o the t r a n s dimer. The assi g n m e n t s of the measured I P ' s f o r these s p e c i e s a r e s u p p o r t e d by HAM/3 c a l c u l a t i o n s . Breakdown of Koopmans' theorem and the o c c u r r e n c e of shake-up peaks i n the Hel r e g i o n a r e c o n f i r m e d f o r CH 3NO by c a l c u l a t i o n s w i t h the RSPT and m o d i f i e d HAM/3 programs r e s p e c t i v e l y . 1 93 Chapter 8 A study of monomeric n i t r o s o m e t h a n e r i t s c i s and t r a n s d i m e r s , and formaIdoxime 8. 1 I n t r o d u c t i o n The dimer of n i t r o s o m e t h a n e , (CH 3NO) 2, e x i s t s a t room temperature i n two i s o m e r i c forms, c i s and t r a n s , which undergo i s o m e r i z a t i o n r e l a t i v e l y e a s i l y . The c i s dimer has been s y n t h e s i z e d by the p y r o l y s i s ( 1 - 3 ) , or p h o t o l y s i s (1,4,5) of t - b u t y l n i t r i t e , or the p e r i o d a t e o x i d a t i o n of N-methyl-h y d r o x y l a m i n e ( 6 ) , w h i l s t the t r a n s isomer has been p r e p a r e d by the p h o t o l y s i s of t - b u t y l n i t r i t e ( 1 ) . The c i s dimer c o n v e r t s e a s i l y t o the t r a n s dimer upon h e a t i n g ( 1 ) , or s i m p l y by d i s s o l v i n g i n a s o l v e n t w i t h a low d i e l e c t r i c c o n s t a n t , e.g. CHC1 3 ( 1 , 6 ) . The r e v e r s e o c c u r s upon i r r a d i a t i o n w i t h u l t r a v i o l e t l i g h t ( 1 ) . Formaldoxime, CH2=NOH, an o t h e r s t r u c t u r a l isomer of n i t r o s o m e t h a n e i s always p r e s e n t i n the s y n t h e s i s of the n i t r o s o m e t h a n e dimer ( 1 - 6 ) , and can be g e n e r a t e d d i r e c t l y by h e a t i n g the dimer i n s o l u t i o n or s o l i d form ( 1 ) . I t i s a c o l o r l e s s l i q u i d which t r i m e r i z e s a t room temperature t o h e x a h y d r o - 1 , 3 , 5 - t r i h y d r o x y - t r i a z i n e . A l t h o u g h some p h y s i c a l measurements have been made on n i t r o s o m e t h a n e i n c l u d i n g the e l e c t r o n i c spectrum ( 7 , 8 ) , and the microwave spectrum ( 9 , 1 0 ) , and s e v e r a l t h e o r e t i c a l c a l c u l a t i o n s p a r t i c u l a r l y r e l a t e d t o the s t r u c t u r a l isomers ( 1 1 ) , e l e c t r o n i c spectrum ( 8, 12-14) and r o t a t i o n a l b a r r i e r (15,16) have been 194 p e r f o r m e d , t h e r e s t i l l remains some a m b i g u i t y i n the PE spectrum of t h i s m o l e c u l e (17-19). H e a t i n g the c i s dimer i n t o a PE s p e c t r o m e t e r gave a spectrum of monomeric CH 3NO w i t h I P ' s i n r e a s o n a b l e agreement w i t h CNDO (8,17) and ab i n i t i o (12) c a l c u l a t i o n s . However, h e a t i n g the t r a n s n i t r o s o m e t h a n e dimer gave an e n t i r e l y d i f f e r e n t PE spectrum (18) w i t h t h r e e IP's below l2eV. To compound the problem f u r t h e r , a d d i t i o n a l work on XNO type m o l e c u l e s (19) gave the same spectrum of the CH3NO monomer as i n Ref. 17, but the spectrum t h e r e a s s i g n e d t o the s t a r t i n g m a t e r i a l c i s (CH 3NO) 2 i s , as we s h a l l show, i n f a c t t h a t of formaldoxime ( 2 0 ) . In t h i s work we w i s h t o c l a r i f y the c o n f u s i o n r e l a t i n g t o the PE s p e c t r a of n i t r o s o m e t h a n e , the c i s and t r a n s dimers and formaldoxime. To a s s i s t i n the i d e n t i f i c a t i o n of these s p e c i e s we have performed mass s p e c t r o s c o p i c measurements under the same c o n d i t i o n s as the PE e x p e r i m e n t s as d e s c r i b e d b e f o r e . We have a l s o performed some s e m i - e m p i r i c a l HAM/3 (21,22) c a l c u l a t i o n s f o r a l l t h e s e m o l e c u l e s , an ab i n i t i o c a l c u l a t i o n i n c l u d i n g p e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' theorem (23) and some shake-up c a l c u l a t i o n s f o r CH 3NO t o support our c o n c l u s i o n s . 8.2 E x p e r i m e n t a l A. S y n t h e s i s of the compounds and sa m p l i n g p r o c e d u r e s (a) c i s (CH 3NO) 2: The bes t method f o r s y n t h e s i z i n g c i s (CH 3NO) 2 t u r n e d out t o be the p e r i o d a t e o x i d a t i o n of 1 95 N-methylhydroxylamine ( 6 ) . P y r o l y s i s and p h o t o l y s i s of t-BuONO were a l s o t r i e d but w i t h l i m i t e d s u c c e s s . The w h i t e s o l i d o b t a i n e d m e l t e d a t 99-99.5°C and gave uv and i r s p e c t r a i d e n t i c a l t o tho s e of the c i s dimer ( 1 ) . The sample was i n t r o d u c e d i n t o the i o n i z a t i o n chamber of the PE s p e c t r o m e t e r by h e a t i n g the s o l i d 4cm from the i o n i z a t i o n p o i n t . T h i s experiment was r e p e a t e d u s i n g a l o n g e r heated i n l e t tube packed w i t h g l a s s wool. PE and mass s p e c t r a were r e c o r d e d i n both i n s t a n c e s under a v a r i e t y of c o n d i t i o n s . (b) t r a n s (CH 3NO) 2: The t r a n s dimer was o b t a i n e d by d i s s o l v i n g the c i s dimer i n CHC1 3 and then s l o w l y e v a p o r a t i n g the s o l v e n t ( 6 ) . The c o l o r l e s s c r y s t a l s m e l t e d a t 126.8-127.0°C and gave an i r spectrum i d e n t i c a l t o t h a t of t h e t r a n s dimer ( 1 ) . S i m i l a r s a m p l i n g p r o c e d u r e s t o those d e s c r i b e d above were used t o o b t a i n PE and mass s p e c t r a . (c) CH2=NOH: Formaldoxime was s y n t h e s i z e d by c o n d e n s a t i o n of formaldehyde and h y d r o x y l a m i n e ( 2 4 ) . The w h i t e s o l i d o b t a i n e d s u b l i m e d between 90-134 0C and d i d not g i v e a m e l t i n g p o i n t even i n a s e a l e d t u b e . The i r spectrum was i d e n t i c a l t o t h a t d e s c r i b e d i n the l i t e r a t u r e (1 ).. The sample was heated i n t o the s p e c t r o m e t e r a t about 43°C and the PE and mass s p e c t r a o b t a i n e d . The PE spectrum, even a f t e r passage of the vapor t h r o u g h g l a s s wool a t t e m p e r a t u r e s up t o 200°C was i d e n t i c a l t o t h a t o b t a i n e d by D a r g e l o s e t a l . ( 2 0 ) , and t o t h a t p u r p o r t i n g t o be the c i s (CH 3NO) 2 s p e c i e s ( 1 9 ) . 196 B. T h e o r e t i c a l c a l c u l a t i o n s C a l c u l a t i o n s were performed on monomeric n i t r o s o m e t h a n e , the c i s and t r a n s d i m e r s , and formaldoxime u s i n g the s e m i - e m p i r i c a l HAM/3 method (21) which has been shown t o g i v e e x c e l l e n t IP v a l u e s f o r a wide v a r i e t y of m o l e c u l e s (see a l s o c h a p t e r 4 ) . The c a l c u l a t e d I P ' s , e x p e r i m e n t a l I P ' s and geo m e t r i e s used f o r the c a l c u l a t i o n s a r e g i v e n i n Ta b l e 1-4. For comparison purposes l i t e r a t u r e r e s u l t s u s i n g o t h e r t y p e s of c a l c u l a t i o n s a r e i n c l u d e d . We have a l s o c a l c u l a t e d the v e r t i c a l I P ' s of CH3NO u s i n g the GAUSSIAN 70 (25) and RSPT (26)programs, and the r e s u l t s a r e summarized i n T a b l e 5. The e a r l i e r geometry q u o ted i n Ref. 9 was adopted i n s t e a d of t h a t i n Ref. 10 f o r the above c a l c u l a t i o n s s i n c e i t gave a s u p e r i o r SCF t o t a l energy. A m o d i f i e d HAM/3 program (27) has a l s o been used t o study the v a l e n c e - e l e c t r o n shake-up p r o c e s s e s of CH3NO. The o r b i t a l e n e r g i e s from a u s u a l HAM/3 c a l c u l a t i o n can be a d j u s t e d e m p i r i c a l l y t o f i t the r e s u l t s of subsequent CI and v a l e n c e - e l e c t r o n shake-up c a l c u l a t i o n s w i t h the e x p e r i m e n t a l e l e c t r o n i c a b s o r p t i o n spectrum and the PE spectrum. 8.3 R e s u l t s The r e s u l t s of the above e x p e r i m e n t s may be summarized: (a) H e a t i n g c i s (CH 3NO) 2 i n t o the PE s p e c t r o m e t e r g i v e s TABLE 1 Experimental and theoretical IP's a of monomprir nitrosomethane Orbital Symmetry Exp t l . b HAM/3C MIND0/3C CNDOd CND0e ab in i t io^ ab in i t io^ 10a' 9.68±0.05 9.56 9.11 11.8 11 .75 11.50 10.39 2 a " 14.3 14.00 12.86 14.7 15.33 14.94 15.16 9 a " 13.8 13.96 11 .75 16.0 16.21 . 15.59 15.62 l a " 16.9 h 16.18 15.35 19.5 17.93 17.52 8a' 15.8 15.60 14.26 19.8 18.21 18.26 7a' 16.9 h 16.83 15.40 20.2 19.23 19.16 6a' 20.90 21 .07 23.88 23.43 a A l l values in eV. b Al l IP's ± 0.1 eV except as specif ied. c This work. The geometry is taken from ref . [9] d Ref. [19] e Ref. [8] f Ref. [12] g The nitroso group is eclipsed to the methyl group as in c [28]. h The l a " and 7a' ionizations are unresolved. 198 TABLE 2 f y p p r i m e n t a l a n d theoretical IP's * of nipnomeric formaldoxime, Orbital Symmetry ExptV Theoretical HAM/3C MIND0/3C 4-31 G d Ab i n i t i o6 2 a " 10.5910.02 10.60 10.04 11.33 11.16 10a' 11.12+0.05 11.49 9.38 12.04 12.24 l a " 14.3 14.23 • 13.80 16.27 9a' 14.9 15.06 12.57 16.27 8a' 16.1 15.76 14.35 17.71 7a' 17.5 17.53 16.64 21.06 6a' 18.3 19.93 20.28 22.64 a All values in eV. b Al l IP's are ± 0.1 eV except as speci f ied, c This work. Geometry is taken from Ref.[30]. d Ref. [20] e The hydrogen of the hydoxyl group is trans to the coplanar hydroc the methylene as in c [28]. 199 TABLE 3 Experimental and theoretical IP's a of the trans nitrosomethane dimer Orbital h SCF-CIH Symmetry Expt l D HAM/3 (CNDO) 3a u 8.63 ± 0.05 8.92 10.58 10ag 9.91 ± 0.01 9.93 11 .96 9b u 10.77 ± 0.05 10.94 13.07 2 b 9 11.5 12.51 14.18 2 a u 13.6 13.98 14.02 8 b u 14.33 l b 9 14.86 8 a 9 15.41 t 0.05 15,35 7b u 16.91 t 0.05 17.30 l a u 18.15 7 a 9 18.55 6b .--u 18.2 18.68 6 a 9 22.60 a Al l values in eV except as specif ied, b A l l IP's i 0.1 eV. C This work. Geometry is taken from Ref.[31]. d Ref. [8]. 200 TABLE 4 Theoretical IP's a of the cis nitrosomethane dimpr Orbital Symmetry HAM/3 b SCF-CI(CNDO) 3bj 8.13 12.42 10aj 9.11 12.09 9b 2 9.68 13.58 2a 2 11.28 10.19 8b2 13.78 2bj 13.96 7b2 14.81 l a 2 15.42 9a, 15.55 8a) 16.32 lbj 17.47 7ai 18.41 6b2 19.02 6a2 24.12 5b2 24.69 5a j 27.89 4b2 29.64 a Al1 values in eV. b This work. Geometry is taken from Ref.[32J. C Ref. [8] TABLE 5 A comparison of observed and theoretical IP's a calculated by RSPT for monomeric nitrosomethane Orbital Symmetry Exptl' Perturbation corrections results ST03G ST04-31G 3rd order A ( E G A ) Extrapolated A ( E G A ) GAUSSIAN 70 l Scaled perturbation 10a' 9.68f0.05 8.40 11 .20 9.24 9.10 9.5 9.67 9a' 13.8 13.36 15.32 13.69 13.65 14.0 2 a " 14.3 12.30 14.65 14.00 14.00 14.2 14.26 8a' 15.8 15.89 18.14 16.37 16.05 16.4 7a' 16.9 16.83 18.95 16.39 16.30 16.6 l a " 16.13 17.65 16.39 16.39 16.6 6a' 21 .79 23.58 20.58 20.46 20.9 a Al l values in eV. b Al l IP's ± 0.1 eV except as specified, c Geometry taken from Ref. [9]. d See text. r o o 202 monomeric formaldoxime, CH2=NOH, up t o about 80°C, and a t about 95°C monomeric n i t r o s o m e t h a n e , CH 3NO, i s the major p r o d u c t i n the vapor phase. The s p e c i e s d e s c r i b e d by Bergmann e t a l . ( " l 9 ) as the c i s dimer i s a c t u a l l y CH2=NOH, a l t h o u g h they d i d o b t a i n a spectrum of CH 3NO a t h i g h e r t e m p e r a t u r e s . The PE spectrum of CH3NO and i t s c o r r e s p o n d i n g PIM s p e c t r a o b t a i n e d under the same c o n d i t i o n s a r e shown i n F i g . 1. H e a t i n g the sample f u r t h e r over Pyrex wool gave no change i n the spectrum. F u r t h e r v e r i f i c a t i o n t h a t CH2=NOH i s the low temperature s p e c i e s was made by t r a p p i n g t h e vapor en r o u t e i n t o the s p e c t r o m e t e r . A w h i t e s o l i d d e p o s i t s which m e l t s a t room t e m p e r a t u r e , and then r e s o l i d i f i e s . T h i s w h i t e s o l i d has s u b l i m i n g c h a r a c t e r i s t i c s and an i r spectrum i d e n t i c a l t o those of t r i m e r i c f ormaldoxime. (b) H e a t i n g t r a n s (CH 3NO) 2 i n t o the PE s p e c t r o m e t e r at about 28°C g i v e s a spectrum i d e n t i c a l t o t h a t o b t a i n e d by E g d e l l e t a l . ( l B ) . As we s h a l l see l a t e r t h i s i s inde e d the t r a n s dimer, and not the monomer as c l a i m e d ( 1 8 ) . The IP v a l u e s a re the same as those f o r the t r a n s dimer p u b l i s h e d by Bergmann et a l . ( l 9 ) . The PE and mass s p e c t r a a r e shown i n F i g . 2, the mass spectrum u n e q u i v o c a l l y showing the presence of the dimer. When t r a n s (CH 3NO) 2 i s passed over Pyrex wool a t about 220°C the PE spectrum o b t a i n e d i s t h a t of monomeric CH 3NO. At lower t e m p e r a t u r e s the PE spectrum shows a m i x t u r e of the t r a n s dimer and monomer, w i t h no e v i d e n c e f o r CH2=NOH. (c) The PE spectrum of formaldoxime i s s i m i l a r t o t h a t 203 (b) Hel PIM sppr.triim (c) hi^ PIM spectrum •NO -CH 3 N0 (a) Hel PE spectrum CH.NQ 1 1 i l 1 8 12 16 eV IONIZATION POTENTIAL Fig. 1 The Hel PE spectrum (a) of nitrosomethane together with thp  PIM spectra recorded with (b) Hel and (c) H L ^ radiation 204 (b) Hel PIM spectrum (c) HL. n PIM spectrum I N0+ I CH3N0+-1 I I I I I I 10 14 18 eV IONIZATION POTENTIAL Fig. 2 The Hel PE spectrum of the trans nitrosomethane dimer together with fb) the Hel and (c) the Hl a g PIM spectra 2 0 5 o b t a i n e d p r e v i o u s l y ( 2 0 ) , and i s shown i n F i g . 3 t o g e t h e r w i t h the mass s p e c t r a . The c r a c k i n g p a t t e r n found u s i n g both Hel and H L opr s e r v e s t o d i s t i n g u i s h CH2=NOH ( F i g . 3) from CH3NO ( F i g . 1 ). T h i s s p e c i e s does not i s o m e r i z e below 200°C. (d) In a d d i t i o n t o the PE and mass s p e c t r o s c o p i c r e s u l t s , HAM/3 c a l c u l a t i o n s ( T able 1-4) p r o v i d e a d d i t i o n a l c o n f i r m a t i o n f o r the c o r r e c t i d e n t i f i c a t i o n of a l l these s p e c i e s . In the absence of a PE spectrum f o r the c i s dimer, the c a l c u l a t i o n ( T a ble 4) p r o v i d e s some i n d i c a t i o n of the p o s i t i o n and o r d e r i n g of the I P ' s which a r e e x p e c t e d t o be much more a c c u r a t e than the p r e v i o u s l y o b t a i n e d CNDO r e s u l t s ( 8 ) . (e) The GAUSSIAN 70 4-31G c a l c u l a t i o n s ( T able 5) g i v e an o r d e r i n g of t h e f i r s t seven o c c u p i e d m o l e c u l a r o r b i t a l s of CH 3NO as 10a', 2a", 9a', 1a", 8a', 7a' and 6a', and a 3a" l o w - l y i n g u n o c c u p i e d MO, which i s c o n s i s t e n t w i t h some o t h e r p r e v i o u s ab i n i t i o r e s u l t s ( T a b l e 1). The p e r t u r b a t i o n c o r r e c t i o n s d e c r e a s e a l l the I P ' s o b t a i n e d by the 4-31G c a l c u l a t i o n s ; but the two IP ' s c o r r e s p o n d i n g t o the two a" o r b i t a l s r e t a i n r e l a t i v e l y h i g h e r v a l u e s . T h i s i s c o n s i s t e n t w i t h the d i s c u s s i o n i n Chapter 2 (2.2C). The o r d e r i n g of i o n i z a t i o n i s 10a', 9a', 2a", 8a', 7a', Va" and 6a', w i t h the I P ' s f o r the 7a' and 1a" o r b i t a l s p r e d i c t e d t o be q u i t e c l o s e t o g e t h e r . Only two I P's ar e r e p o r t e d from the s c a l e d p e r t u r b a t i o n c a l c u l a t i o n s because they e s t i m a t e v e r y good I P ' s f o r the h i g h e s t o c c u p i e d MO of each symmetry s p e c i e s , but not f o r the r e s t . 206 (b) Hel PIM spectrum (c) HL n PIM spectrum <*3Y , CH2N0H+ (a) Hel PE spectrum IONIZATION POTENTIAL f i g . 3 The Hel PE spectrum (a) of formaldoxime together  with (b) the Hel and (c) HL PIM spectra 207 8.4 D i s c u s s i o n We have now e s t a b l i s h e d t h a t t he c i s (CH 3NO) 2 s p e c i e s g i v e s CH2=NOH up t o about 80°C and CH 3NO above 90°C. H e a t i n g t o a h i g h e r temperature over Pyrex wool s t i l l g i v e s the pure CH 3NO monomer, i n d i c a t i n g t h a t the i s o m e r i z a t i o n of the c i s ni t r o s o m e t h a n e dimer t o formaldoxime o c c u r s p r o b a b l y w h i l e the c i s dimer i s s t i l l i n the s o l i d s t a t e . The f o r m a t i o n of the CH2=NOH s p e c i e s a t a temperature some 10°C below t h a t a t which c i s (CH 3NO) 2 d i s s o c i a t e s c o m p l e t e l y i n t o the monomeric form i s r a t h e r u n u s u a l . The thermodynamics of t h i s c o m p l i c a t e d system w i l l have t o be r e - e v a l u a t e d b e f o r e a prop e r i s o m e r i z a t i o n mechanism can be d e v e l o p e d . We have made many a t t e m p t s t o o b t a i n the PE spectrum of the c i s dimer u s i n g a v a r i e t y of methods, i n c l u d i n g h e a t i n g the dimer w i t h i n 2cm of the i o n i z a t i o n p o i n t a t minimal t e m p e r a t u r e s , and a d i a b a t i c a l l y expanding CH3NO th r o u g h a s m a l l n o z z l e . In both i n s t a n c e s , o n l y CH 2=NOH or CH 3NO a l o n e a re formed, With no e v i d e n c e f o r the c i s dimer i s o b t a i n e d . The HAM/3 c a l c u l a t i o n s s e r v e as a b a s i s f o r the assignments of the PE s p e c t r a and a r e p r e s e n t e d i n Tab l e 1-4. They w i l l not be d i s c u s s e d i n any d e t a i l h e r e , except t o say t h a t those f o r CH 2=NOH ( T a b l e 2) a r e i n agreement w i t h the p r e v i o u s r e s u l t s ( 20,28), e s p e c i a l l y c o n c e r n i n g t h e r e l a t i v e o r d e r i n g of the f i r s t two c l o s e l y spaced s t a t e s . Those f o r t r a n s (CH 3NO) 2 (Table 3) c l o s e l y f i t our e x p e r i m e n t a l spectrum ( F i g . 2) and the e x p e r i m e n t a l I P ' s of Ref. 19. They a l s o i n d i c a t e t h a t the 208 e a r l i e r spectrum of E g d e l l et a l . ( l 8 ) i s a c t u a l l y t h a t of the t r a n s dimer. C H 3 N O p r e s e n t s an i n t e r e s t i n g assignment problem (Table 1 ) , s i n c e e a r l i e r c a l c u l a t i o n s on HNO i n v o l v i n g p e r t u r b a t i o n c o r r e c t i o n s t o Koopmans' Theorem i n d i c a t e d t h a t the theorem d i d not h o l d i n t h i s case ( 3 3 ) . T h i s p r e d i c t i o n i s su p p o r t e d by our RSPT c a l c u l a t i o n on CH3NO. The low l y i n g u noccupied ir o r b i t a l causes a s w i t c h i n g of 2a" w i t h 9a' and l a " w i t h 8a' o r b i t a l s a f t e r c o r r e c t i o n s a r e a p p l i e d t o the SCF r e s u l t s . HAM/3 a l s o p r e d i c t s t h i s o r d e r i n g . The RSPT c a l c u l a t e d I P ' s a r e a l l w i t h i n 0.5eV of the e x p e r i m e n t a l v a l u e s . A p l o t of p r e d i c t e d I P ' s T a g a i n s t the v a l u e s 10" (where T i s the t r u n c a t i o n c r i t e r i o n ) ( F i g . 4) shows t h a t t h i s d i s c r e p a n c y s h o u l d d e c r e a s e as more d e t e r m i n a n t s a r e c o n s i d e r e d . An e x c e p t i o n t o t h i s t r e n d i s the s m a l l PE band a t l5.8eV. Due t o t h i s e x c e p t i o n , and the low i n t e n s i t y and broadness of t h i s band, and the presence of a low l y i n g v i r t u a l o r b i t a l , we have done some shake-up c a l c u l a t i o n s w i t h the m o d i f i e d HAM/3 program. The r e s u l t s (Table 6) show t h a t s i m u l t a n e o u s e x c i t a t i o n of an e l e c t r o n from the 2a" or 1a" MO t o the 3a" MO d u r i n g the i o n i z a t i o n of an e l e c t r o n from the 10a' MO does mix s i g n i f i c a n t l y w i t h the i o n i z a t i o n from the 8a' MO. A c c o r d i n g l y , two g e n e r a l i z a t i o n s can be drawn f o r m o l e c u l e s h a v i n g l o w - l y i n g v i r t u a l o r b i t a l s : (a) Koopmans' theorem may be i n v a l i d ( 3 3 ) ; (b) V a l e n c e - e l e c t r o n shake-up p r o c e s s e s may be impo r t a n t even i n the Hel r e g i o n . THEORETICAL IP g PA ' -T Fig. 4 A plot of theoretical IP's of CHoN0 (A(E ) of the RSPT results) against the truncation l imi t , 10 210 TABLE 6 Interpretation of the ionization and shake-up processes of CH3N0 in the Hel region by the modified HAM/3 method Peak Intensity Ionization and shake-up processes position 9.58 0.97 10a'" 1 13.77 0.83 9 a ' " 1 14.29 0.98 2a"" 1 15.68 0.54 8 a ' " 1 ; 10a'" 1 * (2a" - 3a") c 16.49 0.48 10a'" 1 * (2a" - 3a") ; 8 a 1 " 1 ; lOa ' - l * ( la" - 3a") 16.87 0.84 l a " " 1 17.43 0.85 7 a ' " 1 20.96 0.94 6 a ' " 1 a. All values in eV. b. Relative intensity. Only the peaks with intensity greater than 0.12 are described here. c. One electron is ionized from the 10a1 orbital together with the excitation of an electron from the 2a" orbital to the 3a" o rb i ta l . The ordering represents the importance of the processes. 21 1 The l a t t e r p o i n t i s p a r t i c u l a r l y i m p o r t a n t because shake-up p r o c e s s e s i n the Hel r e g i o n have been i g n o r e d i n the past by most .PE s p e c t r o s c o p i s t s and the r e s u l t a n t s a t e l l i t e peaks a re j u s t s i m p l y n e g l e c t e d or a t t r i b u t e d t o i m p u r i t i e s . 8.5 C o n c l u s i o n I t has been demonstrated t h a t the PES/PIMS system, combined w i t h some quantum m e c h a n i c a l c a l c u l a t i o n s can be s u c c e s s f u l l y used t o e v a l u a t e the i o n i z a t i o n p r o c e s s e s i n a c o m p l i c a t e d gas phase system, i n t h i s c a s e , the CH 3NO, c i s and t r a n s (CH 3NO) 2, and CH2=NOH m i x t u r e . T h i s has c l a r i f i e d s e v e r a l a m b i g u i t i e s noted i n e a r l i e r work and a l s o a i d s i n u n d e r s t a n d i n g the unusual shake-up p r o c e s s e s of CH 3NO i n the Hel r e g i o n . We note t h a t w h i l e t h i s work was i n i t s c o n c l u d i n g s t a g e s , the a u t h o r s of Ref. 18, r e p e a t e d t h e i r e a r l i e r work, and show (29) t h a t the PE spectrum of CH 3NO i s as d e s c r i b e d i n t h i s t h e s i s . I n a d d i t i o n , t h e i r CI c a l c u l a t i o n s a l s o . p r e d i c t the breakdown of Koopmans' theorem f o r t h i s m o l e c u l e . 212 References (Chapter B) 1. B.G. Gowenlock and J . Trotman, J . Chem. S o c , (1955)4190. 2. B.G. Gowenlock and J . Trotman, J . Chem. S o c , (1956)1670. 3. A.D. Y o f f e , R e s e a r c h , 7(1954)544. 4. C.S. Coe and T.F. Doumani, J . Am. Chem. S o c , 70(1948) 1516. 5. G.R. M c M i l l a n , J.G. C a l v e r t and S.S. Thomas, J . Phys. 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Nat., 30b(1975)629. 18. R. E g d e l l , J.C. Green, C.N.R. Rao, B.G. Gowenlock and J . Pf a b , J . Chem. S o c , Faraday T r a n s . 2, (1976)988. 19. H. Bergmann, S. E l b e l and R. Demuth, J . Chem. S o c , D a l t o n (1977)401. 20. A. D a r g e l o s and C. S a n d o r f y , J . Chem. Phys., 67(1977)3011. 21. L. Asbrink, C. F r i d h and E. L i n d h o l m , Chem. Phys. L e t t . , 52(1977)69. 22. L. Asbrink, C. F r i d h and E. L i n d h o l m , QCPE 11(1980)393. 23. D.P. Chong, F.G. H e r r i n g and D. M c W i l l i a m s , J . Chem. Phys., 61(1974)78. 24. R. S c h o l l , Chem. Ber . , 24.1(1891)573. 25. W.J. Hehre, W.A. L a t h a n , R. D i t c h f i e l d , M.D. Newton and J . A. P o p l e , QCPE 11(1973)236. 26. D.P. Chong, p r i v a t e communication t o W.M. Lau. (see a l s o Ref. 23) 27. D.P. Chong, p r i v a t e communication t o W.M. Lau. 28. M.A. Robb and I.G. C s i z m a d i a , J . Chem. Phys.,50(1969)1819. 29. N.P. E r n e s t i n g , J . P f a b , J.C. Green and J . Romelt, J . Chem. Soc. Faraday T r a n s . 2, 76(1980)844. 30. I.N. L e v i n e , J . Chem. Phys., 38(1963)2326. 31. M. van Meerssche and G. Germain, B u l l . S o c Chim. B e l g . , 68(1959)244. 32. G. Germain, P. P i r e t and M. van Meerssche, A c t a C r y s t . , 16 (1963)109. 214 33. D.P. Chong, F.G. H e r r i n g and D. M c W i l l i a m s , J . E l e c t r o n S p e c t r o s c . R e l a t . Phenom., 7(1975)445. 215 LLL£. A study of some weakly a s s o c i a t e d m o l e c u l e s by u s i n g  a f a s t pumping n o z z l e i n l e t system The f i n a l examples of system a p p l i c a t i o n s i n c l u d e an area which i s l i k e l y t o become of i n c r e a s i n g i m p o r t a n c e ; t h a t i s the study of weakly a s s o c i a t e d complexes. T h i s moves t h e study of u n s t a b l e m o l e c u l e s f u r t h e r ahead, and p r o v i d e s a c o n v e n i e n t m a r r i a g e between m o l e c u l a r beam t e c h n i q u e s and the i n t e r a c t i o n s of such beams w i t h l i g h t s o u r c e s . The f u t u r e p r o s p e c t of the i n t e r a c t i o n of m o l e c u l a r beams w i t h r e l i a b l e t u n a b l e uv l a s e r s w i l l open up a new e r a of UPS, p r o v i d i n g the i n v e s t i g a t i o n of a much g r e a t e r range of I P ' s a t much h i g h e r r e s o l u t i o n , w i t h the added o p t i o n of s t u d i e s under t h r e s h o l d c o n d i t i o n s . The p r e s e n t system i s d e s i g n e d t o approach these r e q u i r e m e n t s . Under the t y p i c a l h i g h vacuum c o n d i t i o n s of PES e x p e r i m e n t s , a weakly a s s o c i a t e d m o l e c u l e i s of c o u r s e l i k e l y t o be d i s s o c i a t e d i n t o i t s c o n s t i t u e n t s . However, an a d i a b a t i c e x p a n s i o n of the c o n s t i t u e n t m o l e c u l e s t h r o u g h a n o z z l e i n l e t w i l l reduce the l o c a l t e mperature and enhance the pr o d u c t y i e l d due t o the e x o t h e r m i c n a t u r e of i t s f o r m a t i o n . Two such s p e c i e s have been s t u d i e d : 2N0 2 * N 20, and ( C H 3 ) 2 0 + BF 3 *r=^ ( C H 3 ) 2 0 - B F 3 N20<, i s formed at h i g h s t a g n a t i o n p r e s s u r e s (about 1 atm.) w i t h a s m a l l n o z z l e (about 60M). I t s y i e l d i s b e t t e r 216 than 80%. The s u c c e s s i n f o r m i n g t h i s well-known s p e c i e s d emonstrates the c a p a b i l i t y of the p r e s e n t n o z z l e system. T h i s , t o g e t h e r w i t h the t h e o r e t i c a l s t u d y of the breakdown of Koopmans' theorem and the shake-up p r o c e s s e s , i s t r e a t e d i n Chapter 9. ( C H 3 ) 2 0 - B F 3 , i n a d i f f e r e n t a p proach, i s formed by a p p l y i n g a r e l a t i v e l y low s t a g n a t i o n p r e s s u r e (about 3 t o r r ) a c r o s s a l a r g e n o z z l e (about 0.4mm). The y i e l d i n t h i s case i s o n l y 30%. However, a spectrum s t r i p p i n g p r o c e d u r e g i v e s a 'pure' Hel PE spectrum of t h i s complex. Ab i n i t i o and s e m i - e m p i r i c a l MO c a l c u l a t i o n s have been c a r r i e d out t o a s s e s s i t s geometry and e l e c t r o n i c s t r u c t u r e . T h i s study i s d e s c r i b e d i n Chapter 10. 217 Chapter 9 N ?0„ 9.1 I n t r o d u c t i o n The thermodynamics of the monomer-dimer e q u i l i b r i u m between N0 2 and N 2 0 e i n the gaseous phase has been s t u d i e d e x t e n s i v e l y ( 1 , 2 ) . N 2 0 a , e x i s t i n g w i t h a h i g h mole f r a c t i o n at room temperature and 1 atm., i s d i a m a g n e t i c w i t h a p l a n a r s t r u c t u r e and a l o n g N-N bond (1 . 7 8 A compared t o 1 .47A i n N 2H„)(3,4). A l t h o u g h N 2O f t d i s s o c i a t e s c o m p l e t e l y t o N0 2 under h i g h vacuum a t room t e m p e r a t u r e , Hel and H e l l PE s p e c t r a of t h i s s p e c i e s have been o b t a i n e d by v a r i o u s c o o l i n g t e c h n i q u e s ( 5 - 1 0 ) . Among t h e s e , t he a d i a b a t i c e x p a n s i o n of the sample gas through a s m a l l n o z z l e w i t h a h i g h s t a g n a t i o n p r e s s u r e i s the most s u c c e s s f u l method(5,7-10). The h i g h e s t mole f r a c t i o n of N 20„ so f a r o b t a i n e d i s about 68% ( 8-10). E x t e n s i v e MO c a l c u l a t i o n s of N 20„ have a l s o been done u s i n g ab i n i t i o (11-14) and s e m i - e m p i r i c a l methods(15). However, a r e c e n t ab i n i t i o Green's f u n c t i o n study of the p h o t o i o n i z a t i o n of N 20, (16) has p o i n t e d out the breakdown of Koopmans' theorem as w e l l as the o c c u r r e n c e of shake-up p r o c e s s e s , t h e r e b y a c c o u n t i n g f o r the c o m p l e x i t y of the spectrum above l5eV. T h i s c h a p t e r d e s c r i b e s the study of N 20« w i t h our m o d i f i e d s p e c t r o m e t e r w hich c o n s i s t s of an o p t i o n a l cryopump and a n o z z l e i n l e t , u s i n g d i f f e r e n t n o z z l e s i z e s . Ab i n i t i o c a l c u l a t i o n s (GAUSSIAN 70, 4-31G), and s e m i - e m p i r i c a l HAM/3 c a l c u l a t i o n s i n c l u d i n g shake-up p r o c e s s e s ' have a l s o been performed and compared w i t h t he p r e v i o u s r e s u l t s . 218 9.2 E x p e r i m e n t a l The c o n s t r u c t i o n of the cryopump has been d e s c r i b e d i n Chapter 3. The n o z z l e s o f s i z e s r a n g i n g from 400»» t o 50» were made of Pyrex t u b e s . The t i p of the n o z z l e was not c o a t e d w i t h c o n d u c t i n g m a t e r i a l but kept j u s t s h o r t of the i o n i z a t i o n p o i n t by some 5mm. N0 2 (Matheson) was p u r i f i e d by pumping o f f the v o l a t i l e i m p u r i t i e s a t -78°C, and then i n t r o d u c e d t o the g l a s s i n l e t tube c o u p l e d d i r e c t l y t o the n o z z l e t i p . I t s p u r i t y was m o n i t o r e d by the PE/PIM s p e c t r o m e t e r . The cryopump was then brought t o -196°C and the s t a g n a t i o n p r e s s u r e was i n c r e a s e d t o keep the p r e s s u r e a t the i o n gauge a t about 1X10~ 5 t o r r . To a c h i e v e s t a g n a t i o n p r e s s u r e s h i g h e r than 1 atm., a g l a s s n o z z l e w i t h a c o l d t r a p was used. T h i s whole d e v i c e was heated t o about 40°C a f t e r enough sample had been c o l l e c t e d i n s i d e the t r a p and the d e v i c e was i s o l a ' t e d from the sample l i n e . The s t a g n a t i o n p r e s s u r e under these c i r c u m s t a n c e s was about 2 atm., measured by a m e c h a n i c a l p r e s s u r e gauge. Ab i n i t i o c a l c u l a t i o n s were performed by the GAUSSIAN 70 p r o g r a m ( l 7 ) a t the 4-31G l e v e l u s i n g the known g e o m e t r y U ) . The HAM/3 program, used t o c a l c u l a t e I P ' s and s a t e l l i t e l i n e s , was of a m o d i f i e d v e r s i o n ( l 9 ) . 9.3 R e s u l t s N0 2 i s the o n l y gaseous phase s p e c i e s observed when a n o z z l e of 400* i s used a t a s t a g n a t i o n p r e s s u r e of i t o r r 219 w i t h o u t cryopumping. However, about 10% N 20, i s o b t a i n e d w i t h a n o z z l e of 100»/ a t a s t a g n a t i o n p r e s s u r e of 50 t o r r even w i t h o u t cryopumping. The s t a g n a t i o n p r e s s u r e can be s u b s t a n t i a l l y i n c r e a s e d when the cryopump i s c o o l e d down t o -196°C. The most extreme case i s t h a t of a n o z z l e of about 50»# a t a s t a g n a t i o n p r e s s u r e of about 2 atm. However, t h i s h i g h s t a g n a t i o n p r e s s u r e causes a d e g e n e r a t i o n of the s t a b i l i t y of the sampling system because N 20, condenses near the n o z z l e . The best y i e l d of N 2 O t t i s a c h i e v e d by u s i n g a n o z z l e of about 60* a t a s t a g n a t i o n p r e s s u r e of about 1 atm. The Hel PE spectrum, Hel mass spectrum and HLcpy mass spectrum r e c o r d e d under t h e s e o p t i m a l c o n d i t i o n s are shown i n F i g . 1, F i g . 2a and 2b r e s p e c t i v e l y . The Hel PE spectrum of N0 2 i s a l s o shown i n F i g . 1 f o r comparison. A 'pure' Hel PE spectrum of N 20„ ( F i g . 3) i s o b t a i n e d by s u b t r a c t i n g out t h e r e s i d u a l N0 2 i n t h e N 20,/N0 2 m i x t u r e u s i n g our spectrum s t r i p p i n g p r o c e d u r e . The absence of the s h a r p band of N0 2 a t l8.8eV and the unique band of N0 2 a t 14.5eV i n d i c a t e s the q u a l i t y of the N 20„ spectrum. The amount of r e s i d u a l N0 2 i s e s t i m a t e d as 4% by comparing the t o t a l i n t e n s i t y of the f i r s t band (broad band a t 11.2eV) of the N0 2 PE spectrum w i t h t h a t of the f i r s t band (broad band a t 11.4eV) of the N 20«/N0 2 PE spectrum. The t h e o r e t i c a l I P ' s from the 4-31G c a l c u l a t i o n s and the HAM/3 c a l c u l a t i o n s a r e summarized i n T a b l e 1 t o g e t h e r w i t h t h e e x p e r i m e n t a l I P ' s and the o u t e r v a l e n c e type Green's f u n c t i o n r e s u l t s ( l 6 ) . These t h e o r e t i c a l I P ' s , the two p a r t i c l e - h o l e Tamm-Dancoff a p p r o x i m a t i o n (2ph-TDA) Green's f u n c t i o n r e s u l t s 220 IONIZATION POTENTIAL Fig. 1 PE spectra of (a) NO. and (b) N o0, / N0„ mixture 221 ) HL a3y (a) Hel -*r-• ' I I I L 50 amu j i L 100 Fig- 2 The mass spectra of the / NO,, mixture ionized bv fa) Hel and lb) HI radiation. ctpy 223 TABLE 1 The experimental and theoretical IP 's a of Orbital Symmetry Exptl^ IP 0.92x^_ 31G NAM/3d Outer Green 11.4 11.83 11.27 11.23 % 12.35±.01 13.95 12.97 12.57 l a u 13.041.02 13.13 13.18 12.80 lb. Ig 13.471.02 13.37 13.20 13.09 4b, 3u 15.26 13.08 13.90 5b. lu 15.6 18.17 16.54 lb_ H 17.0 19.70 18.05 3b _ 2g 18.651.05 19.77 19.04 20.15 19.15 l b2u 20.93 19.24 5a g 22.08 19.82 a. A l l values in eV. b. A l l values iO.leV except as specified. c. This work. d. This work (no shake-up corrections) e. Ref. 16. 224 and the HAM/3 shake-up r e s u l t s a r e p l o t t e d i n F i g . 4 which c l e a r l y shows the e x i s t e n c e of s a t e l l i t e l i n e s above "5eV. 9.4 p i s c u s s i o n E q u i l i b r i u m c a l c u l a t i o n s from known d a t a ( l , 2 ) i n d i c a t e t h a t o n l y 0.02% of N 20, would e x i s t a t room temperature i n the i o n i z a t i o n chamber w i t h a p r e s s u r e as h i g h as 0.01 t o r r . However, by c o o l i n g t o -100°C, the c o r r e s p o n d i n g mole f r a c t i o n jumps t o 9 6 % (89% i f the p r e s s u r e a t the i o n i z a t i o n p o i n t i s 0.001 t o r r ) . T h i s c o o l i n g e f f e c t i s r e a l i z e d by e i t h e r d i r e c t c o o l i n g or an a d i a b a t i c e x p a n s i o n of the sample gas t o the i o n i z a t i o n chamber through a n o z z l e ( 5 - 1 0 ) . The r e s u l t s of p r e v i o u s e x p e r i m e n t s t o g e t h e r w i t h t h o s e of the p r e s e n t work a r e summarized i n Tab l e 2. The mole f r a c t i o n of N 20, has been e s t i m a t e d e i t h e r by the peak h e i g h t r a t i o of the second bands of the N 2O a and the r e s i d u a l N0 2 i n the N 20,/N0 2 PE spectrum (5) (Method A ) , or the t o t a l i n t e n s i t y r a t i o of the s t r i p p e d spectrum ('pure' N 2O s) and the N 2O f t/N0 2 PE spectrum (18) (Method B ) . The former method i s used here t o r o u g h l y e s t i m a t e the mole f r a c t i o n of N 20, i n the p r e v i o u s l y r e p o r t e d PE s p e c t r a . These v a l u e s a r e t a b u l a t e d i n T a b l e 4. The mole f r a c t i o n of N 20« i n our PE spectrum ( F i g . 1) i s 8 8 % (Method A) and 8 4 % (Method B ) . S i n c e the band shape, the p o s i t i o n and the MO c h a r a c t e r of the f i r s t bands of the N 20« and N0 2 PE s p e c t r a a r e v e r y s i m i l a r ( except t h a t t h e r e i s some weak N-N * bond c h a r a c t e r i n the case l ti 11 II 10 12 14 16 18 20 IONIZATION POTENTIALS(eV) 22 g u l=6a I 2=la. 3= lb 4=4b 5=4b 6= 5b 7=lb 8= 3b 9=3b 10= lb ll=5a 12=4b lg 2g 3u lu 3g 2g 3u 2u g lu Fig. 4 Experimental and theoretical PE spectra of N^ O^  a. GAUSSIAN 70, 4-31G calculations (x0.92) b. HAM/3 IP's calculations c. HAM/3 shake-up calculations d. Modified HAM/3 shake-up calculations (see text) e. 2ph-TDA Green's function (Ref. 16) TABLE 2 Experimental results of the formation of NpO^by PES studies This work Ames Yamazaki Frost Gan Nomoto et a l . a et a l . b et a l . c et a l . d et a l . e Temp, of sample source R .T . f R.T. -60°C -40°C R.T. R.T. Application of nozzle stagnation pressure(atm.) 1 1.2 0.01 1 0.8 nozzle diameter(/c) 60 20 - 300 60 60 Yield of HLO-(mole fraction) estimated by Method A 9 0.88 0.6 0.2 0.6 0.7 0.7 estimated by Method B h 0.84 - - - 0.68 estimated by Method C1 0.96 a. Ref. 5. f . Room Temperature (no direct cooling of the sample source). b. Ref. 6. g. By the peak-height ratio of the 2nd PE bands of N0o and N o 0- . c Ref. 7. (see text) c c q d. Ref. 8. h. By the total intensity rat io of the stripped PE spectrum and e. Ref. 9 . the PE spectrum of the NO^/^O* mixture, (see text) i . By the total intensity ratio of the 1st PE bands of N0? and NpO .^ (see text) ro ro 2 2 7 of N 2 0 „ ) , we assume t h a t they have a s i m i l a r i o n i z a t i o n c r o s s s e c t i o n and use the t o t a l i n t e n s i t i e s of these two bands t o e s t i m a t e the mole f r a c t i o n of N 2 0 « (Method C ) . T h i s g i v e s 9 6 % . Hence, i t i s c l e a r t h a t the p r e s e n t s t u d y does g i v e a y i e l d of N 2 0 , h i g h e r than 8 0 % which i s v e r y much s u p e r i o r t o t h a t a c h i e v e d i n p r e v i o u s work, and so p e r m i t s a more a c c u r a t e measurement of the I P ' s of N 2 0 6 . In the o p t i m a l c a s e , as s t a t e d above, the n o z z l e diameter i s about 6 0 x and the s t a g n a t i o n p r e s s u r e i s about 1 atm. A f r e e j e t i s hence formed s i n c e the mean f r e e p a t h of the gas ( 0 . 0 3 d ) i s much l e s s than the n o z z l e d i a m e t e r . The Mach number M a t a d i s t a n c e x from a n o z z l e w i t h d i a m e t e r d can thus be e s t i m a t e d by the s t a n d a r d e x p r e s s i o n ( 2 0 ) where r i s the r a t i o of the s p e c i f i c h e a t s and A and x 0 depend on the v a l u e of r . r i s e s t i m a t e d t o be about 1 . 1 2 by the d a t a of Ref. 2 , and A and x 0 ( 2 0 ) a r e e x t r a p o l a t e d t o be 4 . 2 2 and 50>/ r e s p e c t i v e l y . M i s thus about 7 w i t h x = 5mm. The temperature a t t h i s p o i n t T, i s g i v e n by the e q u a t i o n ( 2 1 ) _ T = <  where T 0 i s the source t e m p e r a t u r e , R i s the gas c o n s t a n t , M i s the Mach number and C v i s the s p e c i f i c heat a t c o n s t a n t volume. T, i s thus e s t i m a t e d t o be - 1 9 8 ° C . At t h i s temperature the mole f r a c t i o n of N 2 O i , i s v i r t u a l l y 1 0 0 % . In f a c t t o o b t a i n 9 6 % of N 2 0 « , a temp e r a t u r e of - 1 1 0 ° C i s s u f f i c i e n t l y low. The 226 o v e r e s t i m a t i o n of the temperature i s p r o b a b l y due t o the f a c t t h a t the parameters used throughout a re not p r e c i s e l y c o r r e c t , and the i m p e r f e c t n e s s of the n o z z l e . However, t h i s crude e s t i m a t i o n does show t h a t a s u b s t a n t i a l c o o l i n g e f f e c t can be o b t a i n e d w i t h the p r e s e n t e x p e r i m e n t a l arrangement. In s p i t e of the h i g h mole f r a c t i o n of N 20, observed i n the PE, spectrum ( F i g . 1 ) , the mass s p e c t r a ( F i g . 2) r e c o r d e d under the same s a m p l i n g c o n d i t i o n s do not show any peaks h i g h e r than 46 amu ( N 0 2 * ) . T h i s absence of a p a r e n t dimer i o n i s p r o b a b l y due t o the r a t h e r l o n g N-N bond, p e r m i t t i n g the dimer t o r e a d i l y d i s s o c i a t e . L owering the p r e s s u r e i n s i d e the i o n i z a t i o n chamber i n c r e a s e s t he i n t e n s i t y r a t i o of the N0 2* t o NO* peaks. Hence f r a g m e n t a t i o n i s s i g n i f i c a n t l y i n d u ced by i o n - m o l e c u l e c o l l i s i o n s . Another i n t e r e s t i n g p o i n t i s t h a t the H L o p r mass spectrum ( F i g . 2b) shows more f r a g m e n t a t i o n than t h a t of the Hel mass spectrum ( F i g . 2 a ) . S i n c e HLo r a d i a t i o n ( 40.20eV) cannot i o n i z e N0 2 or N 2O f t, the r e l e v a n t s o u r c e r a d i a t i o n i s the HLp r a d i a t i o n (12.09eV). T h i s s u g g e s t s t h a t the p a r e n t i o n c o r r e s p o n d i n g t o the f i r s t broad PE band of N 20, c e n t e r e d a t 11.4eV i s i n a r e p u l s i v e e l e c t r o n i c s t a t e . S i m i l a r t o the o t h e r p r e v i o u s ab i n i t i o c a l c u l a t i o n s (11, 12, 16), our 4-31G r e s u l t s g i v e an o r d e r i n g of 6 a g , l a ^ , 1b,^, 4b 2g and 4 b 3 t L f o r the f i r s t f i v e o r b i t a l s . T h i s o r d e r i n g has been r e v i s e d by the Green's f u n c t i o n s t u d y which p r e d i c t s the breakdown of Koopmans' theorem as w e l l as the e x i s t e n c e of s a t e l l i t e l i n e s above 1 5 e V ( l 6 ) . The 4 b 2 g " 1 i o n i z a t i o n i s thus i n t e r p r e t e d as the second I P . Our HAM/3 c a l c u l a t i o n s g i v e 229 s i m i l a r r e s u l t s but the 4b 3 u." 1 i o n i z a t i o n i s s h i f t e d t o the s m a l l e r IP r e g i o n . The o r d e r i n g i s t h e r e f o r e 6ag, 4t>2j» 4 b 3 a , l a ^ and 1 i>,g. The HAM/3 shake-up c a l c u l a t i o n s a l s o p r e d i c t s a t e l l i t e l i n e s w i t h I P ' s g r e a t e r than 14eV. These p r e l i m i n a r y HAM/3 shake-up r e s u l t s have been then m o d i f i e d by a d j u s t i n g the t h e o r e t i c a l I P ' s b e f o r e the shake-up c a l c u l a t i o n s (see a l s o Chapter 2 and Chapter 8 ) . The r e f e r e n c e s f o r the adjustment a re the e x p e r i m e n t a l e l e c t r o n i c e x c i t a t i o n energy (3.65eV) (22) and the e x p e r i m e n t a l PE spectrum ( F i g . 3 ) . The main i o n i z a t i o n p r o c e s s e s ( i n t e n s i t y h i g h e r than 30%) p r e d i c t e d by these m o d i f i e d HAM/3 shake-up c a l c u l a t i o n s a r e d e s c r i b e d i n T a b l e 3. The t h e o r e t i c a l PE s p e c t r a of our 4-31G c a l c u l a t i o n s , the 2ph-TDA Green's f u n c t i o n s t u d y , our HAM/3 I P ' s c a l c u l a t i o n s and shake-up c a l c u l a t i o n s a r e p l o t t e d i n F i g . 4. A l t h o u g h the q u a l i t y of t h e i n e x p e n s i v e HAM/3 r e s u l t s i s i n f e r i o r t o t h a t of the Green's f u n c t i o n r e s u l t s , they do show the breakdown of Koopmans' theorem and the e x i s t e n c e of shake-up p r o c e s s e s . 9.5 C o n c l u s i o n The f o r m a t i o n of N 20, under h i g h vacuum has been s t u d i e d by the PES/PIMS system equipped w i t h a cryopump and a n o z z l e i n l e t . A y i e l d of N 20, h i g h e r than 80% has been a c h i e v e d by u s i n g a n o z z l e of 60* a t a s t a g n a t i o n p r e s s u r e of 1 atm. T h i s h i g h y i e l d i n d i c a t e s t h a t the p r e s e n t system s h o u l d be u s e f u l i n 230 TAR I F" 3 interpretation of the ionization and shake-up processes of N 20. in the Hel region by the modified HAM/3 method Energy Intensity Ionization and shake-up processes 11.20 0.92 6a - 1 g 12.15 0.88 2g 13.06 0.90 la " 1 u 13.28 0.89 lu 13.43 0.77 4b"1 3u 15.34 0.46 5b! 1 ; lu (6a -6b, )*6a_1 g lu' g 16.61 0.35 (6a -6b g , )*6a_1 ; 5b?1 lu' g ' lu 17.26 0.52 lb" 1 ; (lb, -2b0 ) * l a _ 1 lg 2u^  u 18.38 0.84 3b!1 2g 18.69 0.72 3b:1 3u 19.38 0.39 5ag ' (4b_ -6b. )*4b:1 3u \uJ 2g 22.10 0.94 4b"1 lu a. All values in eV. b. Relative intensity. Only the peaks with intensity greater than 0.3 are described here. c. One electron is excited from the 6a orbital to the 6b, orbital g lu together with the ionization of an electron from the 6a^_ orbital. The ordering represents the importance of the processes. 231 the s t u d i e s of o t h e r weakly a s s o c i a t e d s p e c i e s . S i m i l a r t o the r e s u l t s of the p r e v i o u s Green's f u n c t i o n s t u d y , the i n e x p e n s i v e HAM/3 c a l c u l a t i o n s p r e d i c t t h e breakdown of Koopmans' theorem and the e x i s t e n c e of shake-up p r o c e s s e s due t o i n t e r a c t i o n s w i t h the low l y i n g u n o c c u p i e d o r b i t a l s . 232 R e f e r e n c e s (Chapter 9) 1. W.F. Giauque and J.D. Kemp, J . Chem. Phys., 6(1938)40. 2. I.C. H i s a t s u n e , J . Phys. Chem., 65(1961)2249. 3. D.W.Smith and K. Hedberg, J . Chem. Phys., 25(1956)1282. 4. B.W. M c C l e l l a n d , G. Gundersen and K. Hedberg, J . Chem. Phys., 56(1972)4541. 5. D.L. Ames and D.W. T u r n e r , P r o c . R. Soc. London, S e r . A, 348(1976)175. 6. T. Yamazaki and K. Kimura, Chem. Phys. L e t t . , 43(1976)502. 7. D.C. F r o s t , C.A. McDowell and N.P.C. Westwood, J . E l e c t r o n S p e c t r o s c . R e l a t . Phenom., 10(1977)293. 8. T.H. Gan, J.B. P e e l and G.D. W i l l e t t , J . Chem. Soc. Faraday T r a n s . 2, 73(1977)1459. 9. K. Nomoto, Y. A c h i b a and K. Kimura, Chem. Phys. L e t t . , 63 (1979)277. 10. K. Nomoto, Y. A c h i b a and K. Kimura, B u l l . Chem. Soc. J p n . , 52(1979)1614". 11. R. A h l r i c h s and F. K e i l , J . Am. Chem. S o c , 96(1974)7615. 12. J.M. H o w e l l and J.R. van Wazer, J . Am. Chem. S o c , 96(1974) 7902. 13. L.C. Snyder and H. Basch, ' M o l e c u l a r wave f u n c t i o n s and p r o p e r t i e s ' , W i l e y , New Y o r k ( l 9 7 2 ) . 14. R.L. G r i f f i t h s , R.G.A.R. McClagan, and L.F. P h i l l i p s , Chem. Phys., 3(1974)451. 15. S. K i s h n e r , M.A. Whitehead and M.S. Go p i n a t h a n , J . Am. Chem. S o c , 100( 1 978)1365. 233 16. W. von N i e s s e n , W. Domcke, L.S. Cederbaum, and J . S c h i r m e r , J . Chem. Soc. Faraday T r a n s . 2, 74(1978)1550. 17. W.J. Hehre, W.A. L a t h a n , R. D i t c h f i e l d , M.D. Newton and J.A. P o p l e , QCPE 11(1973)236. 18. J.B. P e e l , p r i v a t e communication t o D.C. F r o s t . 19. D.P. Chong, p r i v a t e communication t o W.M. Lau. 20. T.A. M i l n e and F.T. Greene, Adv. Chem., 72(1968)68. 21. A. K a n t r o w i t z and J . Grey, Rev. S c i . I n s t r u m . , 22(1951)328. 22. T.C. H a l l , J r . and F.E. B l a c e t , J . Chem. Phys., 20(1952) 1745. 234 Chapter 10 The study of a 1:1 charge transfer complex r  (CH,) 70-BF, 10.1 I n t r o d u c t i o n PES of charge t r a n s f e r complexes has been g a i n i n g i n c r e a s i n g a t t e n t i o n i n r e c e n t y e a r s . E a r l i e r work comprised s t u d i e s of some s t r o n g l y a s s o c i a t e d complexes such as the complexes of borane w i t h ammonia, mono-, d i - and t r i m e t h y l a m i n e , carbon monoxide and phosphorus t r i f l u o r i d e ( 1 , 2 ) , the complexes of boron t r i f l u o r i d e w i t h d i - and t r i m e t h y l a m i n e ( 3 ) , the p y r i d i n e - i o d o m o n o c h l o r i d e complex (4) and the a l k y l a m i n e -bromine complexes ( 5 ) . Weak complexes a r e i n h e r e n t l y more d i f f i c u l t t o s t u d y a t t h e low p r e s s u r e r e q u i r e d f o r the PE experiment and so r e c o u r s e t o a s u p e r s o n i c n o z z l e i n l e t i s one approach t o t h i s problem; the i s e n t r o p i c e x p a n s i o n from a h i g h s t a g n a t i o n p r e s s u r e i n d u c e s the c o o l i n g n e c e s s a r y f o r complex f o r m a t i o n . Such a n o z z l e i n l e t system has a l r e a d y been a p p l i e d t o the study of some weak complexes such as those i n v o l v i n g d i m e t h y l e t h e r w i t h hydrogen c h l o r i d e ( 6 ) , hydrogen f l u o r i d e (7) and s u l f u r d i o x i d e ( 8 ) , and the d i m e t h y l s u l f i d e - hydrogen f l u o r i d e complex ( 7 ) . In the p r e c e d i n g c h a p t e r , we have a p p l i e d such a t e c h n i q u e t o study the 2N0 2^= iN 2O u system. The thermodynamics of the 1:1 ( C H 3 ) 2 0 - B F 3 complex has been s t u d i e d by s e v e r a l groups ( 9 - 1 3 ) , the most r e c e n t i n v e s t i g a t i o n showing t h a t the complex has a heat of d i s s o c i a t i o n of 13.65 K c a l / m o l and d i s s o c i a t e s by 60% a t 60°C ( 1 3 ) . The o r i g i n a l e l e c t r o n d i f f r a c t i o n measurement (12) has been r e p e a t e d more 235 r e c e n t l y (14) and the r e v i s e d s t r u c t u r e i s sup p o r t e d by ab i n i t i o c a l c u l a t i o n s ( 1 5 ) . In o r d e r t o p r o v i d e a comparison and i n t e r p r e t a t i o n of the observed PE spectrum, we have performed f u r t h e r ab i n i t i o and s e m i - e m p i r i c a l c a l c u l a t i o n s on the geom e t r i c and e l e c t r o n i c s t r u c t u r e of the complex. 10.2 E x p e r i m e n t a l Boron t r i f l u o r i d e and d i m e t h y l e t h e r (Matheson) were condensed i n a c o l d t r a p a t l i q u i d n i t r o g e n t e m p e r a t u r e . The m i x t u r e was warmed s l o w l y w i t h o c c a s i o n a l pumping t o remove exce s s r e a c t a n t s . The complex, a c o l o r l e s s l i q u i d at room t e m p e r a t u r e , was t r a n s f e r r e d t o the sp e c t r o m e t e r i n l e t i n a g l a s s tube w i t h a t e f l o n n e e d l e v a l v e , and a d m i t t e d t o the sp e c t r o m e t e r a t 22°C. The s a t u r a t e d vapor p r e s s u r e a t t h i s t e m perature was about 3 t o r r as measured by a manometer, and t h i s was the maximum s t a g n a t i o n p r e s s u r e used i n thes e e x p e r i m e n t s . The complex f o r m a t i o n was s t u d i e d w i t h d i f f e r e n t n o z z l e s i z e s (0.1 - 0.9mm), and w i t h the cryopump o p e r a t i n g a t room or l i q u i d n i t r o g e n t e m p e r a t u r e . Geometry o p t i m i z a t i o n and e l e c t r o n i c s t r u c t u r e c a l c u l a t i o n s were e x p l o r e d u s i n g a m o d i f i e d INDO program ( 1 6 ) , and the MNDO (17) and GAUSSIAN 70 (18) programs. F i n a l t o t a l e n e r g i e s and o r b i t a l e n e r g i e s were computed u s i n g the GAUSSIAN 76 program (19) a t the 4-31G l e v e l . 2 3 6 10.3 R e s u l t s W ith the cryopump o p e r a t i n g a t room te m p e r a t u r e , a sample m i x t u r e of f r e e d i m e t h y l e t h e r and boron t r i f l u o r i d e was obs e r v e d ; the Hel PE spectrum of t h i s m i x t u r e i s shown i n F i g . 1, where peaks p e r t a i n i n g t o the i n d i v i d u a l ( C H 3 ) 2 0 and BF 3 components can be matched t o t h e i r known PE s p e c t r a (20, 2 1 ) . Upon c o o l i n g the cryopump t o -196°C, s u b s t a n t i a l changes a r e o bserved i n the PE spectrum i n c l u d i n g two new d i s t i n c t peaks a t 15eV and 18 - 19eV and i n t e n s i t y changes i n o t h e r r e g i o n s . The Hel PE spectrum under the s e c o n d i t i o n s i s shown i n F i g . 2 and the c o r r e s p o n d i n g Hel mass spectrum and HLo mass spectrum a r e shown i n F i g . 3. The o p t i m a l n o z z l e s i z e f o r the complex f o r m a t i o n i s about 0.4mm a t a s t a g n a t i o n p r e s s u r e of about 3 t o r r . No complex f o r m a t i o n i s observ e d i f the n o z z l e i o n i z a t i o n p o i n t d i s t a n c e i s g r e a t e r than 1.5cm. The Hel PE spectrum of the "pure" complex ( F i g . 4) was o b t a i n e d by s t r i p p i n g out the m i x t u r e of the f r e e r e a c t a n t s ( F i g . l ) from the spectrum w i t h complex f o r m a t i o n ( F i g . 2 ) . S i n c e the sample i s a 1:1 m i x t u r e of the two r e a c t a n t s , and the complex i s a l s o a 1:1 addu c t , the two operand s p e c t r a a r e o n l y n o r m a l i z e d by the f i r s t unique peak a t l0.05eV. The r e s u l t s of the geometry o p t i m i z a t i o n c a l c u l a t i o n s a r e shown i n Ta b l e 1, t o g e t h e r w i t h the r e l a t i v e e n e r g i e s and the e x p e r i m e n t a l geometry o b t a i n e d from the e l e c t r o n d i f f r a c t i o n e x p e r i m e n t s (12, 14). The m o d i f i e d INDO method p r e f e r s a s h o r t O-B bond which i s c l o s e t o Bauer's geometry ( 1 2 ) . The MNDO method shows two l o c a l minima, one of which i n d i c a t e s Ionization potential (eV) Fig. 1 The Hel PE spectrum of a 1:1 mixture of (CH 3 )QO and B F 3 obtained from a complete  dissociation of the ( C H ^ O - B F ^ complex. B F ^ peaks are marked with an asterisk. Ionization potential (eV) Fl'q- 2 The Hel PE spectrum of the 1:1 (CH 3) 20-BF 3 complex plus the free constituents g 239 A M U Fig. 3 The mass spectra of the 1:1 (CH3),,0-BF3 complex  plus the free constituents obtained (a) with a Hel l ight source, and (b) with f i l tered HL — _ a  l ight source. 1 I 1 I 1 I 1 I 1 — I — 1 — I — 1 I — I — I — I — I — I — I — I — [ - 1 10 12 14 16 18 2 0 Ionization potential (eV) Fig. 4 The stripped Hel PE spectrum of the 1:1 (CH 3 ) 2 0-BF 3 complex T A B L E 1 The results of geometry optimizations on the 1 : 1 c o m n l p x (nr^O-wi^ and a comparison of the total energies obtained by SCF calculations on the complex. (CHj^O and BF . _ a 3 2 3 Experimental geometry' BF 3 (CH 3) 20 (CH 3) 20-BF 3  Bauer et a l . Shibata et a l . Optimized geometry b MNDO [12] [14] INDO geom. rBF 1.313 - 1.43 1.358 1.343 1.32 1.498 para-r co - 1.416 1.45 1.425 1.437 1.41 1.406 _ c meter <coc - 111 .7 109.5 108.4 114.6 111.7 114.3 rB0 - - 1.50 1.719 1.812 4.06 1.575 0 - - 54.7 33.4 0 1.7 67.84 <OBF - - 109.5 99.0 101.6 90.4 105.75 Relative energy (au) INDO MNDO 82.55396 55.64235 35.89606 24.37749 118.74023 79.97374 79.99022 80.02065 118,87864 Total ST03G energy (au) 431G 322.78497 153.83532 470.80860 476.65502 a. Geometries: BFy ref. [25]; (CH^O, ref. [26]. b. Two local minima. c Bond lengths ln A , angles in degrees. Labels referred to Fig. 5, 470.81476 470.71452 ro -P. 242 e s s e n t i a l l y no bonding e x i s t s between the two components. A l s o shown i n T a b l e 1 ar e the t o t a l e n e r g i e s o b t a i n e d u s i n g the ab i n i t i o GAUSSIAN 70 program a p p l i e d t o S h i b a t a ' s geometry ( 1 4 ) , the m o d i f i e d INDO o p t i m i z e d geometry and one of the MNDO l o c a l minima g e o m e t r i e s . The t h e o r e t i c a l o r b i t a l e n e r g i e s f o r the complex o b t a i n e d from the MNDO and 4-31G c a l c u l a t i o n s u s i n g the geometry of r e f . 14 a r e shown i n Ta b l e 2 t o g e t h e r w i t h the a p p r o p r i a t e o r b i t a l symmetries (assuming C g symmetry f o r the m o l e c u l e ) . The e x p e r i m e n t a l I P ' s are a l s o l i s t e d , and the assignments (assuming Koopmans' theorem) are d i s c u s s e d i n the next s e c t i o n . 10.4 D i s c u s s i o n A. Complex f o r m a t i o n of ( C H 3 ) 2 0 - B F 3 From the e q u a t i o n g i v e n i n r e f . 13, the s a t u r a t e d vapor p r e s s u r e above the complex i s 3.1 t o r r at 25°C. The p a r t i a l vapor p r e s s u r e of the complex i t s e l f i s 2.0 t o r r and the degree of d i s s o c i a t i o n i s about 55%. I f the gas m i x t u r e i s i s o t h e r m a l l y expanded t o the i o n i z a t i o n p o i n t where the l o c a l p r e s s u r e i s e s t i m a t e d as 0.01 t o r r , the degree of d i s s o c i a t i o n i s 99.6%. T h i s e x p l a i n s why the PE spectrum ( F i g . 1) shows only a super i m p o s i t i o n of the two i n d i v i d u a l c o n s t i t u e n t s under f r e e f l o w c o n d i t i o n s . U s i n g the same s e t of e q u a t i o n s and ass u m p t i o n s , the temperature a t the i o n i z a t i o n p o i n t has t o be 243 TABLE 2 The Experimental and theoretical IP's of (CH.)o0-BF 3 Exptal IP's Symmetry 4-31G *0.92 MNDO 12.4 18a' 12.54 13.08 14.0 17a' 13.85 14 .29 14.3 11a" 13.95 14.32 10a" 14.58 14.61 9a" 14.90 14.83 14.6-16.0 16a' 15.30 14.66 8a" 15.56 14.98 15a' 15.82 14.89 7a" 15.88 15.25 16.2 14a' 16.03 15.92 17.7 6a" 17.36 17.74 13a' 17.73 17.45 5a" 18.52 18.94 17.8-19.0 12a' 18.65 18.34 11a' 19.02 19.19 19.9 10a' 19.90 20.81 9a' 23.71 28.39 a. Calculations are based on the geometry of Shibata et al. [14]. All values in eV. 244 about -27°C i n o r d e r t o o b t a i n 30% a s s o c i a t i o n ( a p p r o x i m a t e l y the complex c o n t e n t i n F i g . 2 ) . T h i s temperature drop of approximate 50°C i s a c h i e v e d by the a d i a b a t i c e x p a n s i o n of the gas m i x t u r e through a 0.4mm n o z z l e w i t h f a s t pumping by a cryopump. B. I d e n t i f i c a t i o n of the complex The Hel mass spectrum ( F i g . 3a) of the gas m i x t u r e taken under the same c o n d i t i o n s as those of the PE spectrum ( F i g . 2) u n e q u i v o c a l l y shows the e x i s t e n c e of a 1:1 complex of ( C H 3 ) 2 0 and B F 3 . The f i r s t peak a t 95 amu i s due t o the fragment i o n ( C H 3 ) 2 0 - B F 2 + d e r i v e d from the p a r e n t i o n ( C H 3 ) 2 0 - B F 3 * which does not appear w i t h any a p p r e c i a b l e i n t e n s i t y . T h i s apparent l a c k of a p a r e n t i o n i s a l s o o b s e r v e d f o r BF 3 where BF 2 * i s the dominant i o n . T h i s i s shown i n F i g . 3a where the v e r y s m a l l peak a t 68 amu i s the p a r e n t i o n of B F 3 . The BF 2 * fragment (49 amu) appears as an a p p r e c i a b l e s h o u l d e r on the s i d e of the peak at 46 amu (due t o ( C H 3 ) 2 0 " ) . The peaks a t 80 amu and 61 amu a r e due t o the fragments CH 30-BF 2* and CH 30-BF* r e s p e c t i v e l y . The HLo mass spectrum ( F i g . 3 b ) , r e c o r d e d under i d e n t i c a l c o n d i t i o n s t o t h e Hel mass spectrum, does not show any complex a t a l l , but s i m p l y g i v e s a mass spectrum of ( C H 3 ) 2 0 . T h i s demonstrates t h a t the f i r s t peak o b s e r v e d at l0.05eV i n the PE spectrum w i t h complex f o r m a t i o n ( F i g . 2) does not c o n t a i n any IP b e l o n g i n g t o the complex i t s e l f . Having thus e s t a b l i s h e d t h a t we have not missed the f i r s t I P of ( C H 3 ) 2 0 - B F 3 , and t h a t t h i s peak b e l o n g s s o l e l y t o f r e e ( C H 3 ) 2 0 , we can make use of t h i s 245 f a c t and use the l0.05eV peak t o p r o v i d e an e x c e l l e n t r e f e r e n c e f o r the n o r m a l i z a t i o n of the PE s p e c t r a w i t h , and w i t h o u t , complex f o r m a t i o n ( F i g . 1 and 2 ) . The o c c u r r e n c e of a unique peak a l s o r a i s e s the c o n f i d e n c e l e v e l of the spectrum s t r i p p i n g r e s u l t s . A s e a r c h f o r complexes of BF 3 and ( C H 3 ) 2 0 w i t h c o m p o s i t i o n o t h e r than 1:1 (22) was u n s u c c e s s f u l , d e s p i t e s e v e r a l e x p e r i m e n t s conducted u s i n g an ex c e s s of one of the c o n s t i t u e n t s . No ob v i o u s changes were observed i n e i t h e r the PE or mass s p e c t r a . C. S t r u c t u r e of the complex S i n c e any d i s c u s s i o n of the PE spectrum must b e g i n from the g e o m e t r i c s t r u c t u r e of the m o l e c u l e , we show, i n F i g . 5, the proposed s t r u c t u r e ( 1 4 ) . The geometry of t h i s complex has been o b t a i n e d by two independent e l e c t r o n d i f f r a c t i o n s t u d i e s (12, 14). However, t h e i r r e s u l t s d i f f e r s i g n i f i c a n t l y as shown i n Table 1, p a r t i c u l a r l y w i t h r e g a r d t o the i m p o r t a n t r o B and ZOBF (e i n F i g . 5) pa r a m e t e r s . Our m o d i f i e d INDO o p t i m i z e d geometry i s s i m i l a r t o the geometry of Bauer e t a l . ( l 2 ) , but the MNDO o p t i m i z e d r e s u l t i s c l o s e r t o t h a t of S h i b a t a e t a l . ( l 4 ) i n p r e d i c t i n g a much l o n g e r OB bond l e n g t h (1.812A) d e s p i t e p u t t i n g the parameter © t o 0°. In a d d i t i o n , t he STO-3G c a l c u l a t i o n s i n d i c a t e t h a t the geometry of S h i b a t a e t a l . ( 1 4 ) , and a l s o one of the l o c a l minima by the MNDO method produce b e t t e r t o t a l e n e r g i e s than the geometry o b t a i n e d from the m o d i f i e d INDO 247 method. S i n c e the c a l c u l a t e d d i f f e r e n c e i n t o t a l e n e r g i e s between S h i b a t a ' s geometry and the MNDO l o c a l minimum i s q u i t e s m a l l , we ta k e the geometry of r e f . 14 f o r the 4-31G c a l c u l a t i o n s and use t h e s e r e s u l t s i n the i n t e r p r e t a t i o n of the PE spectrum of the complex. J u s t i f i c a t i o n f o r t h i s c h o i c e i s p r o v i d e d by r e c e n t c a l c u l a t i o n s a t the 4-31G* (4-31G p l u s d f u n c t i o n s ) l e v e l ( 1 5 ) , which c o n f i r m the r e v i s e d geometry. D. Assignment of the PE bands and bonding i n t h e complex Assuming Koopmans' theorem, and a f t e r s c a l i n g by the u s u a l 0.92 f a c t o r , the I P ' s from the 4-31G c a l c u l a t i o n s ( T able 2) match e x t r e m e l y w e l l w i t h the obser v e d I P ' s of the complex shown i n the s t r i p p e d PE spectrum ( F i g . 4 ) . A l t h o u g h the d e n s i t y of o r b i t a l s p r e c l u d e s a d e f i n i t i v e assignment w i t h i n the broad bands, the g e n e r a l matching p e r m i t s a comparison w i t h the I P's of the f r e e m o l e c u l e s . In e s s e n c e , the c a l c u l a t e d MO's c o r r e s p o n d i n g t o ( C H 3 ) 2 0 a r e s t a b i l i z e d by 0.7 - 2.8eV, w h i l s t those b e l o n g i n g t o BF 3 a r e d e s t a b i l i z e d by 1.4 - 3.3eV. T h i s i s i l l u s t r a t e d i n F i g . 6 which shows t h e c l e a r c o r r e l a t i o n between the 4-31G r e s u l t s f o r the complex and those f o r the two c o n s t i t u e n t s , g r a p h i c a l l y d e m o n s t r a t i n g the a f o r e m e n t i o n e d s h i f t s . F i g . 6 a l s o shows the c l o s e c o r r e s p o n d e n c e between the c a l c u l a t e d and e x p e r i m e n t a l v a l u e s f o r f r e e ( C H 3 ) 2 0 and B F 3 , t h e r e b y g i v i n g some a d d i t i o n a l v a l i d i t y t o t h e analogous c a l c u l a t i o n s f o r the complex when compared t o the e x p e r i m e n t a l v a l u e s (Table 2 ) . The ob s e r v e d s h i f t s a r e a t t r i b u t a b l e t o the t r a n s f e r of 248 Fig. 6 0.92xe's of the 4-31G calculations on (CH 3) 20, (CH 3) 20-BF and B F V and experimental values for ( C H j o 0 and BF, 249 e l e c t r o n d e s i t y from ( C H 3 ) 2 0 t o B F 3 . For B F 3 the o v e r a l l d e s t a b i l i z a t i o n i s t h e r e f o r e a r e s u l t of the r e c e p t i o n of t h i s a d d i t i o n a l e l e c t r o n i c charge i n t o the vacant boron pn o r b i t a l , and the subsequent l o s s of symmetry i n g o i n g from p l a n a r ( D 3 h ) BF 3 t o p y r a m i d a l ( C 3 V , l o c a l symmetry) B F 3 . The d e s t a b i l i z a t i o n i s p a r t i c u l a r l y marked f o r the BF 3 a " 2 M0» which, a l t h o u g h d i f f i c u l t t o measure e x p e r i m e n t a l l y w i t h any p r e c i s i o n (due to the broadness of the bands) i s a t l e a s t 3eV (lower l i m i t ) , and i s c a l c u l a t e d t o be 3.3eV. In p l a n a r BF 3 t h i s ' o r b i t a l i s t o t a l l y JT bonding, the l o s s of p l a n a r i t y c o n t r i b u t i n g t o the e x t e n s i v e d e s t a b i l i z a t i o n . I t i s a m a t t e r of some c o n j e c t u r e as t o the r e l a t i v e magnitudes of the s h i f t s due t o the i n c r e a s e d d i f f u s e n e s s i n t h i s MO, and the r e o r g a n i z a t i o n energy from p l a n a r t o p y r a m i d a l geometry. C o n v e r s e l y , f o r ( C H 3 ) 2 0 , t h e r e i s no l o s s of symmetry ( C 2 V , l o c a l symmetry) upon complex f o r m a t i o n , and so the s t a b i l i z a t i o n of a l l o r b i t a l s can be a t t r i b u t e d t o the l o s s of the e l e c t r o n i c charge g i v i n g a nominal p o s i t i v e charge t o the m o l e c u l e , and r e s u l t i n g i n s t r o n g e r bonding. Thus the d e s c r i p t i o n of the complex as ( C H 3 ) 2 0 * * - B F 3 * " i s s u p p o r t e d by our o b s e r v a t i o n s on the PE spectrum and by the 4-31G c a l c u l a t i o n s which i n d i c a t e a net t r a n s f e r of 0.09 e l e c t r o n s from ( C H 3 ) 2 0 t o B F 3 . S p e c i f i c a l l y , the 2 a 2 and 6a, o r b i t a l s of f r e e ( C H 3 ) 2 0 ( m a i n l y oxygen 2p o r b i t a l s ) w i t h e x p e r i m e n t a l I P ' s a t 10.05 and 11.9eV (20) a r e s t a b i l i z e d t o 12.4 and 14.0eV r e s p e c t i v e l y , g i v i n g the f i r s t two o c c u p i e d o r b i t a l s (18a' and 17a') of the complex. The e x p e r i m e n t a l s h i f t s a r e 2.35 and 2.leV 250 r e s p e c t i v e l y . The next two o r b i t a l s of ( C H 3 ) 2 0 a r e the 4b, and *b 2 (at 13.3 and 14.2eV), and a r e both e s s e n t i a l l y bonding CH o r b i t a l s and s u b j e c t e d t o s m a l l e r changes (about 1.0eV). These form the 11a" and 10a" o r b i t a l s of the complex, the f i r s t measured at 14.3eV, the l a t t e r masked i n the broad and i n t e n s e band c e n t r e d at 15.3eV. T h i s band which extends from 14.6 t o l6eV, a l s o c o n t a i n s an a d d i t i o n a l f i v e I P ' s (9a", 16a', 8a", 15a' and 7a") o r i g i n a t i n g from the f i r s t f i v e o r b i t a l s of BF 3 ( a ' , 3e' and e " ) . The o r i g i n a l degeneracy i s removed upon complex f o r m a t i o n , making a s p e c i f i c assignment more d i f f i c u l t . The c a l c u l a t i o n s ( T a b le 2 and F i g . 6) show these f i v e MO's t o be w i t h i n 1eV of each o t h e r . These f l u o r i n e type o r b i t a l s a re d e s t a b i l i z e d by an average of 1.4eV. The s m a l l peak a t l6.2eV . i s a s s i g n e d (not e n t i r e l y unambiguously) t o i o n i z a t i o n from the 14a' o r b i t a l which o r i g i n a t e s from the ir ( a " 2 ) o r b i t a l of B F 3 . As mentioned b e f o r e , t h i s i s the o r b i t a l t h a t shows the g r e a t e s t s h i f t , and p l a c i n g i t a t 16.2eV r e p r e s e n t s a lower l i m i t f o r the magnitude of t h i s s h i f t . The c a l c u l a t i o n s i n d i c a t e a s m a l l c o n t r i b u t i o n of c bonding c h a r a c t e r i n t h i s MO a l s o c o n t r i b u t i n g t o the s h i f t . The next broad band (17 - l9eV) has two r e s o l v e d components, which from the c a l c u l a t i o n s and t h e c o r r e l a t i o n c o r r e s p o n d t o i o n i z a t i o n from f i v e o r b i t a l s , 6a", 13a', 5a", 12a' and 11a'. These a r e m i x t u r e s of the o r b i t a l s , 3 b 1 f 5a y , 1a 2 of ( C H 3 ) 2 0 and the 2e' o r b i t a l s of B F 3 . The p r e c i s e c orrespondence i s not as c l e a r as t h a t f o r the o u t e r v a l e n c e o r b i t a l s , but a suggested d i s t r i b u t i o n i n t o two p l u s t h r e e MO's 251 i s g i v e n by the c a l c u l a t i o n s ( T a b l e 2 ) . The l a s t peak which i s q u i t e s h a r p o c c u r s a t l9.9eV, and r e p r e s e n t s i o n i z a t i o n from the 10a' o r b i t a l which c o n t r i b u t e s a weak e bond between the boron and the t h r e e f l u o r i n e atoms w i t h c o n s i d e r a b l e 2s c h a r a c t e r of t h e boron atom. I t d e r i v e s from the 2a' o r b i t a l of BF 3 which has been o b s e r v e d at 21.5eV i n a H e l l PE spectrum ( 2 3 ) , and was p r e d i c t e d t o g i v e a p a r t i c u l a r l y s h a r p PE b a n d ( 2 l ) . The s t a b i l i z a t i o n of 1.5eV i s i n a c c o r d w i t h the g e n e r a l t r e n d . 10.5 C o n c l u s i o n The f o r m a t i o n of a 1:1 charge t r a n s f e r complex ( C H 3 ) 2 0 - B F 3 , has been s t u d i e d by a PES/PIMS system. S i n c e t h i s i s a weak complex, i t s f o r m a t i o n i s promoted by t h e a d i a b a t i c e x p a n s i o n of the c o n s t i t u e n t gases through a n o z z l e i n l e t . The Hel PE spectrum of the complex i s e x t r a c t e d u s i n g a spectrum s t r i p p i n g p r o c e d u r e . The geometry has been s t u d i e d u s i n g the INDO, MNDO and GAUSSIAN 70 (STO-3G) SCF methods. The r e s u l t s i n d i c a t e t h a t the geometry of Ref. 14 i s more r e a s o n a b l e than t h a t of the e a r l i e r e l e c t r o n d i f f r a c t i o n work, and so t h i s s t r u c t u r e has p r o v i d e d the b a s i s f o r e l e c t r o n i c s t r u c t u r e c a l c u l a t i o n s a t the 4-31G l e v e l . The c a l c u l a t e d I P ' s assuming Koopmans' theorem a r e , i n g e n e r a l , i n e x c e l l e n t agreement w i t h the e x p e r i m e n t a l v a l u e s and a s s i s t i n e s t i m a t i n g the r e l a t i v e s h i f t s of the MO's of each c o n s t i t u e n t upon complex f o r m a t i o n . Thus, the MO's of ( C H 3 ) 2 0 ar e s t a b i l i z e d by 0.7 - 2.8 eV; the f i r s t IP by 2.35eV. The 252 MO's of BF 3 a r e d e s t a b i l i z e d by 1.4 - 3.3eV. These r e s u l t s are a r e f l e c t i o n of the t r a n s f e r of e l e c t r o n i c charge from ( C H 3 ) 2 0 t o the empty pn o r b i t a l of B F 3 ; the SCF c a l c u l a t i o n s i n d i c a t i n g a t r a n s f e r of 0.09 e l e c t r o n s . T h i s i s not l a r g e , i n d i c a t i v e of the weak n a t u r e of the complex, compared t o the ( C H 3 ) 3 N - B F 3 complex which can be i s o l a t e d as a s o l i d and where the f i r s t IP s h i f t s by 3.74eV ( 3 ) . D u r i n g the c o n c l u d i n g s t a g e s of t h i s work we found t h a t a M o l e c u l a r S t r u c t u r e Conference (24) i n c l u d e d an a b s t r a c t r e p o r t i n g a s i m i l a r s t u d y . A l t h o u g h s p e c i f i c d e t a i l s were l i m i t e d , the r e s u l t s appear t o be e s s e n t i a l l y the same as those d e s c r i b e d h e r e i n . 253 R e f e r e n c e s (Chapter 10) 9 1. D.R. L l o y d and N. Lynaugh, J . Chem. S o c , Chem. Comm., (1970) 1545. 2. D.R. L l o y d and N. Lynaugh, J . Chem. S o c , Faraday T r a n s . 2 68(1972)947. 3. R.F. Lake, S p e c t r o c h i m . A c t a , P a r t A, 27(1971)1220. 4. A. Mostad, S. Svensson, R. N i l s s o n , E. B a s i l i e r , U. G e l u i s C. N o r d l i n g and K. Siegbahn, Chem. Phys. L e t t . , 23(1973) 157. 5. C. Utsunomiya, T. Kobayashi and S. Nagakura, Chem. Phys. L e t t . , 39(1976)245. 6. F. C a r n o v a l e , M.K. L i v e t t and J.B. P e e l , J . Am. Chem. Soc. 102(1980)569. 7. F. C a r n o v a l e , p r i v a t e communication t o W.M. Lau. 8. F. C a r n o v a l e , Ph. D. t h e s i s , La Trobe U n i v e r s i t y , 1980. 9. H.C. Brown and R.M. adams, J . Am. Chem. Soc.,64(1942)2557. 10. A.W. Laubengayer and G.R. F i n d l a y , J . Chem. Soc., 65(1943) 884. 11. H.C. Brown and R.M. adams, J . Am. Chem. Soc.,65(1943)2253. 12. S.H. Bauer, G.R. F i n d l a y and A.W. Laubengayer, J . Am. Chem. S o c , 67(1945)339. 13. D.E. M c L a u g h l i n and M. Tamres, J . Am. Chem. Soc., 82(1960) 5618. 14. S. S h i b a t a and K. I i j i m a , Chem. L e t t . Chem. Soc. J p n . , (1977)29. 15. F. H i r o t a , Y.Koyama and S. S h i b a t a , J . M o l . S t r u c t . , 70 254 (1981)305. 16. Y. Fang, p r i v a t e communication t o W.M. Lau. 17. W. T h i e l , QCPE 11(1978)353. 18. W.J. Hehre, W.A. L a t h a n , R. D i t c h f i e l d , M.D. Newton and J.A. P o p l e , QCPE 11(1973)236. 19. J.S. B i n k l e y , R.A. Whitehead, P.C. H a r i h a r a n , R. Seger and J.A. P o p l e , QCPE 11(1978)368. 20. K. Kimura, S. Katsumata, Y. A c h i b a and T. Yamazaki, Mono-graph S e r i e s of the Res e a r c h I n s t i t u t e of A p p l i e d E l e c t r i -c i t y , No. 25: 'Helium I (H e l ) p h o t o e l e c t r o n s p e c t r a of o r -g a n i c compounds', (1978)48. 21. G.H. K i n g , S.S. K r i s h n a m u r t h y , M.F. L a p p e r t and J.B. Ped-l e y , Faraday D i s c u s s . Chem. S o c , 54(1972)327. 22. H.E. W i r t h , M.J. J a c k s o n and H.W. G r i f f i t h s , J . Phys. Chem., 62(1958)871. 23. W.C. P r i c e , A.W. P o t t s and D.G. S t r e e t s , ' E l e c t r o n s p e c t -r o s c o p y ' , D.A. S h i r l e y , ed., N o r t h H o l l a n d , Amsterdam, (1972)187. 24. K. Nomoto, Y. A c h i b a and K. Kimura, A b s t r a c t of M o l e c u l a r S t r u c t u r e C o n f e r e n c e , J p n . , (1980)638. 25. K. K u c h i t s u and S. Konaka, J . Chem. Phys., 45(1966)4342. 26. U. B l u k i s , P.H. K a s a i and R.J. Myers, J . Chem. Phys., 38 (1963)2753. PART IV Summary and P r o g n o s i s 256 Chapter 11 Summary and p r o g n o s i s T h i s t h e s i s d e s c r i b e s an i n t e g r a t e d system f o r the study of u n s t a b l e m o l e c u l e s . The i o n i z a t i o n chamber of a PE sp e c t r o m e t e r has been r e c o n s t r u c t e d and p r o v i d e s an e a s i l y a c c e s s i b l e i o n i z a t i o n r e g i o n . T h i s r e c o n s t r u c t i o n , b e s i d e s r e s u l t i n g i n b e t t e r pumping e f f i c i e n c y , makes f u r t h e r hardware development q u i t e f e a s i b l e . Hence, a q u a d r u p o l e mass s p e c t r o m e t e r has been c o u p l e d t o t h i s PE s p e c t r o m e t e r , s h a r i n g the same i o n i z a t i o n r e g i o n . Ions a r e e x t r a c t e d t o the mass a n a l y z e r i n the o p p o s i t e way where PE's go i n t o an e l e c t r o s t a t i c l e n s system and are fo c u s e d t o the e l e c t r o n a n a l y z e r . At p r e s e n t , t h e s e two a n a l y z i n g p r o c e s s e s a re not c a r r i e d out i n c o i n c i d e n c e . W i t h the s u c c e s s of u s i n g t h i s PES/PIMS system, a l o g i c a l e x t e n s i o n i s t o modify the l e n s system a t the i o n i z a t i o n r e g i o n and add on more t i m i n g hardware t o do c o i n c i d e n c e work, which has been demonstrated t o be a u s e f u l probe of i o n i c s t a t e s ( 1 ) . B e s i d e s the a d d i t i o n of a mass s p e c t r o m e t e r , an e a s i l y removable cryopump and some n o z z l e i n l e t s have been made. The cryopump can be p l a c e d c l o s e t o the i o n i z a t i o n r e g i o n o p p o s i t e t o the n o z z l e i n l e t . T h i s f a s t pumping n o z z l e system has been a p p l i e d s u c c e s s f u l l y t o g e n e r a t e n e a r l y pure N 20„ and a c h a r g e - t r a n s f e r complex, ( C H 3 ) 2 0 - B F 3 , a t t h e low p r e s s u r e of the i o n i z a t i o n r e g i o n . The a d i a b a t i c e x p a n s i o n of the sample gas p r o v i d e s a low temperature f o r the f o r m a t i o n of t h e s e weakly a s s o c i a t e d s p e c i e s . An e x t e n s i o n of t h i s work i s t o study m etal atoms and atomic c l u s t e r s ( m e t a l dimer, t r i m e r . . . ) . The PES 257 study of t h e s e s p e c i e s s h o u l d r e v e a l more of t h e i r bonding p r o p e r t i e s and p r o v i d e a s y s t e m a t i c way t o the u n d e r s t a n d i n g of metal s u r f a c e s , c a t a l y t i c r e a c t i o n s and many o t h e r s o l i d s t a t e e f f e c t s . A double f u r n a c e system has a l r e a d y been made f o r th e s e h i g h t e m p e r a t u r e e x p e r i m e n t s ( F i g . 1 ) , and p r e l i m i n a r y t e s t s a r e b e i n g c a r r i e d o u t . A p p l i c a t i o n s of microcomputers or minicom p u t e r s i n data automation of i n s t r u m e n t s have been expanding r a p i d l y . With a good o p e r a t i n g system program, such an a p p l i c a t i o n w i l l not o n l y save t i m e , b u t , more i m p o r t a n t l y , s t o r e the data e f f i c i e n t l y and s y s t e m a t i c a l l y , r e t r i e v e and m a n i p u l a t e these data w i t h a p p r o p i a t e ' s a f e - g u a r d ' ( e r r o r h a n d l i n g ) r o u t i n e s . T h i s i d e a i s r e a l i z e d by i n t e r f a c i n g the PES/PIMS system w i t h a LSI 11/03 microcomputer and a p p r o p r i a t e hardware. A s m a l l r e a l - t i m e o p e r a t i n g system program has been deve l o p e d t o do data a c q u i s i t i o n , s t o r a g e and m a n i p u l a t i o n . The s i m p l i c i t y of the program from the u s e r s ' p o i n t of v i e w , the o r g a n i z a t i o n of the dat a s t r u c t u r e , the memory management, the f i l e management and the p r o g r a m - m o d u l i z a t i o n have been emphasized i n the development of t h i s program. I t t u r n s out t h a t the whole d i g i t a l system works w e l l and the program can be e a s i l y m o d i f i e d . More data m a n i p u l a t i n g o p t i o n s , such as peak i d e n t i f i c a t i o n , peak p o s i t i o n measurement, i n t e n s i t y i n t e g r a t i o n and spectrum n o r m a l i z a t i o n e t c . , and b e t t e r f i l e management s h o u l d be deve l o p e d t o enhance the performance of the d i g i t a l system. The p r o c e d u r e s f o r the a d d i t i o n of a new data m a n i p u l a t i n g s u b r o u t i n e t o the system program a r e j u s t : — inner furnace cross s e c t i o n ionization pninf nozzle sample i n l e t heater_l heater...2. F l g - 1 The c o n s t r u c t i o n of a double furnace heating u n i t w i t h a nozzle sample i n l e t ro cn Co 259 (1) d e v e l o p the s u b r o u t i n e ; (2) add a l i n k t o the s u b r o u t i n e 'KYINDH' ( r e f e r t o the comment f i e l d of 'KYINDH'in A p p e n d i x ) ; (3) add a b r i e f d e s c r i p t i o n of t h i s s u b r o u t i n e t o the subrou-t i n e 'HELP' ( j u s t f i l e e d i t i o n ) . Together w i t h PE d a t a , quantum m e c h a n i c a l c a l c u l a t i o n s a r e v e r y u s e f u l t o deduce e l e c t r o n i c s t r u c t u r e s as w e l l as o t h e r p r o p e r t i e s of m o l e c u l e s . Hence, a l i b r a r y of computer programs has been e s t a b l i s h e d f o r PE s t u d i e s . I t c o n t a i n s programs from s e m i - e m p i r i c a l CNDO/2, MINDO/3, MNDO, and HAM/3 MO programs, ab i n i t i o GAUSSIAN 70 and 76 MO programs, t o the RSPT program f o r c o r r e c t i n g Koopmans' theorem. B e s i d e s , a m o d i f i e d HAM/3 program can a l s o do v a l e n c e - e l e c t r o n shake-up c a l c u l a t i o n s . In s h o r t , the l i b r a r y p r o v i d e s a wide spectrum of c o m p u t a t i o n a l means f o r PE s t u d i e s . For the f u t u r e study of metal c l u s t e r s , the Xo program w i l l be u s e f u l and s h o u l d be documented and added t o the 1 i b r a r y . The p r e s e n t i n t e g r a t e d system (the microcomputer c o n t r o l l e d PES/PIMS system w i t h the com p u t a t i o n l i b r a r y ) has been a p p l i e d t o t he study of u n s t a b l e m o l e c u l e s o t h e r than the weakly a s s o c i a t e d s p e c i e s . Some s u l f u r - n i t r o g e n compounds, l i k e SuN,, S«N 2, S 3 N 3 and S 2 N 2 , have been g e n e r a t e d and s t u d i e d i n d i v i d u a l l y . The e x i s t e n c e of a r a d i c a l s p e c i e s , S 3 N 3 , has been e s t a b l i s h e d . T h i s , t o g e t h e r w i t h the r e s u l t s of f u t u r e e x p e r i m e n t a l and t h e o r e t i c a l work, w i l l l e a d t o a b e t t e r u n d e r s t a n d i n g of t h i s i n t e r e s t i n g s p e c i e s and the (SN) X polymer. 260 The r a t h e r c o m p l i c a t e d and i n t e r l i n k e d gas phase d e c o m p o s i t i o n of t h e s e f o u r s u l f u r - n i t r o g e n m o l e c u l e s and the unusual condensed phase r e a c t i o n s of S 2 N 2 and S 3 N 3 have a l s o been i n v e s t i g a t e d . The s u c c e s s f u l r e s u l t s demonstrate t h a t the p r e s e n t system can be used t o study gas phase r e a c t i o n s of u n s t a b l e s p e c i e s d y n a m i c a l l y as w e l l as the i n d i v i d u a l u n s t a b l e s p e c i e s i n a s t a t i o n a r y manner. S p e c i e s i d e n t i f i c a t i o n i s always an i m p o r t a n t problem i n the s t u d y of u n s t a b l e s p e c i e s due t o the presence of r e s i d u a l r e a c t a n t s and s i d e p r o d u c t s i n i t s s y n t h e s i s and the u n s t a b l e n a t u r e of the s p e c i e s i t s e l f . The i n t e g r a t i o n of the e f f i c i e n t mass measurements and c o n v e n i e n t d a t a h a n d l i n g f a c i l i t i e s t o the PE i n f o r m a t i o n g r e a t l y enhances the c o n f i d e n c e l e v e l i n s p e c i e s i d e n t i f i c a t i o n . T h i s has been demonstrated by the study of s u l f u r - n i t r o g e n m o l e c u l e s as mentioned above, and the study of CH 3NO, i t s t r a n s and c i s dimer, and i t s isomer CH2NOH. The l a t t e r s t u d y has c l a r i f i e d the e r r o r s o c c u r r i n g i n p r e v i o u s PE s t u d i e s of CH 3NO and i t s dimer. V a l e n c e - e l e c t r o n shake-up p r o c e s s e s i n the Hel r e g i o n have been n e g l e c t e d i n the p a s t by most PE s p e c t r o s c o p i s t s . F a i l u r e of t h i s s i m p l i f i c a t i o n has been demonstrated r e c e n t l y by some Green's f u n c t i o n c a l c u l a t i o n s . Hence the breakdown of the q u a s i p a r t i c l e p i c t u r e i n the Hel r e g i o n has been c o n f i r m e d f o r m o l e c u l e s such as CS, PN, P 2 , N 20„, and S 2 N 2 e t c . ( s e e a l s o c h a p t e r 2 ) . The m o d i f i e d HAM/3 program has t h u s been used t o study the v a l e n c e - e l e c t r o n shake-up p r o c e s s e s of N 2 0 8 and CH3NO. The r e s u l t s show t h a t the m o d i f i e d HAM/3 program i s r e a s o n a b l e 261 i n p r e d i c t i n g shake-up p r o c e s s e s and t h e r e are s a t e l l i t e peaks i n the Hel PE spectrum of t h e s e two m o l e c u l e s . The presence of t h e s e s a t e l l i t e peaks i s d i r e c t l y due t o the o c c u r r e n c e of low l y i n g v i r t u a l o r b i t a l s . A l o g i c a l e x t e n s i o n of t h i s argument i s t h a t shake-up p r o c e s s e s may be i m p o r t a n t even i n the Hel r e g i o n f o r m o l e c u l e s h a v i n g low l y i n g v i r t u a l o r b i t a l s , e s p e c i a l l y f o r c o l o r e d s p e c i e s . The l a t t e r p o i n t i s c o n f i r m e d by a p r e l i m i n a r y Green's f u n c t i o n c a l c u l a t i o n of the 'red' S,N 2. More s i m i l a r shake-up s t u d i e s a r e e x p e c t e d i n the f u t u r e and the above p o i n t s w i l l be used as g u i d e l i n e s f o r such s t u d i e s . R e s o n a n t l y Enhanced M u l t i p h o t o n I o n i z a t i o n S p e c t r o s c o p y (REMPIS) has been expanding r a p i d l y s i n c e t u n a b l e dye l a s e r s were a p p l i e d t o MPI s t u d i e s ( 2 ) . Mass a n a l y s i s of the i o n formed by MPI has .shown i n t e r e s t i n g f r a g m e n t a t i o n p a t t e r n s ( 3 ) . Hence t h i s REMPI t e c h n i q u e p r o v i d e s not o n l y i n f o r m a t i o n about energy l e v e l s of the p a r e n t m o l e c u l e , but a l s o about l o w - l y i n g bound and r e p u l s i v e s t a t e s of the i o n s . However, PES i s o b v i o u s l y an even more d i r e c t probe t o i o n s t a t e s and the i n t e g r a t i o n of the PES t e c h n i q u e t o the REMPIS w i l l d e f i n i t e l y p r o v i d e new e x p e r i m e n t a l impetus t o the r e l a t e d a r e a s . In f a c t , MPI-PES of Xe ( 4 ) , NO ( 5 ) , I 2 (6) and benzene (6) have been done r e c e n t l y and p r o v e d t o be s u c c e s s f u l . In p r a c t i c e , t h e r e i s one s i d e of our c u b i c i o n i z a t i o n chamber r e s e r v e d f o r f u t u r e hardware e x t e n s i o n . T h i s can be used as the l a s e r l i n e w i t h o u t much m o d i f i c a t i o n . When two l a s e r s a r e a v a i l a b l e , the p r e s e n t Hel lamp can be demounted e a s i l y , g i v i n g room t o the a d d i t i o n a l l a s e r . 262 In c o n c l u s i o n , t h i s t h e s i s d e s c r i b e s the development and a p p l i c a t i o n s of a v e r s a t i l e PES/PIMS system f o r s t u d y i n g u n s t a b l e s p e c i e s and t h e i r gas phase r e a c t i o n s . The s u c c e s s i n t h i s work demonstrates the s i g n i f i c a n c e and f e a s i b i l i t y of i n t e g r a t i n g o t h e r hardware and s o f t w a r e t e c h n i q u e s t o a i d PE s t u d i e s . A PES system t h a t can p e r f o r m c o m b i n a t i o n s of m o l e c u l a r beam s t u d i e s , h i g h t emperature work, P E - i o n c o i n c i d e n c e e x p e r i m e n t s and REMPIS w i l l be a l o g i c a l and f r u i t f u l e x t e n s i o n . 263 R e f e r e n c e s (Chapter 11) 1. J.H.D. E l a n d , I n t . J . Mass Spectrom. Ion Phys.., 8( 1972) 143, and 8(1972)153. 2. The f o l l o w i n g r e v i e w s d e s c r i b e some p i o n e e r i n g works i n MPIS and REMPIS: (a) D.H. P a r k e r , J.O. Berg and M.A. E l - S a y e d , 'Advances i n l a s e r c h e m i s t r y ' , A.H. Z e w a i l ed., S p r i n g e r , Ber-l i n , (1978)320. (b) P.M. Johnson, Acc. Chem. Res., 13(1980)20. 3. L. Zandee and R.B. B e r n s t e i n , J . Chem. Phys., 71(1979) 1359, and r e f e r e n c e s i n c l u d e d t h e r e i n . 4. R.N. Compton, J.C. M i l l e r and A.E. C a r t e r and P. K r u i t , Chem. Phys. L e t t . , 71(1980)87. 5. J.C. M i l l e r and R.N. Compton, J . Chem. Phys., 75(1981)22. 6. J.C. M i l l e r and R.N. Compton, J . Chem. Phys., 75(1981) 2020. APPENDIX Codes of the Operating System Program Contents of the Appendix Contents page RECORD 266 ADDSUB 270 BACK 275 BINARY 278 CHANGE 279 CHARAC 282 CLEAR 283 DISK 284 DISPLA 285 EXTRAC 288 FNAME 289 HELP 290 IECHO 291 INFO 292 KYINHD 296 LEVEL 298 OUT 299 PARAME 300 PLOT 302 QUERY 304 SCALE 305 SCAN 307 SEPERA 311 SHOW 313 SMOOTH 316 SQUEEZE 317 STORE 319 SUM 320 WRITE 323 MAIN PROGRAM RECORD VERSION 1.1 1-MAR-81 FUNCTION OF THE PROGRAM IS TO CONTROL A SPECTROMETER WITH A LSI 11 MICRO-COMPUTER. THE JOB INCLUDES DATA ACQUISITION. DATA STORAGE, AND DATA RETRIEVAL. 1. DATA ACQUISITION: THE MAIN PROGRAM ASKS FOR SCANNING PARAMETERS BY CALLING 'PARAME' . THEN CALL 'SQUEEZ' TO MAKE TWO SUITABLE HOLES IN STACK 1, ONE FOR THE CURRENT SCAN CALLEO SPECTRUM 1 AND OTHER FOR THE SUM OF PREVIOUS SCANS CALLED SPECTRUM2. THEN CALL 'SCAN' TO SCAN THE REQUIRED DATA ANO STORE THEM IN STACK 1. EVERY SCAN IS PUT TO A FILE CALLED DK:SPEC.DMP' ON DISK AFTER BEING SCANNED. DURING SCANNING, 'SCAN' WILL CALL 'DISPLA' TO DISPLAY THE SUM (SPECT2) OUT. THE USER'S KEYBOARD INTERRUPT HANDLED BY 'DISPLA' IS ENABLED TO LET THE USER CHANGE SOME OF THE DISPLAY OR SCANNING CONDITIONS. AFTER FINISHED SCANNING, THE CONTROL WILL BE PASSED BACK TO SCAN' (BY SETTING A FLAG TO NEGATIVE TO SIGNAL 'DISPLA' IN ITS INFINITE LOOP). THEN BACK TO MAIN. IF MORE 'SCAN' IS DECIDED BY THE USER, THE ABOVE PROCESS IS REPEATED. OTHERWISE CONTROL IS PASSED TO 'DISPLA' TO DISPLAY THE RESULT. FROM THEN ON, THE USER MAY USE THE KEYBOARD INTERRUPT TO DO DATA MANI-PULATION. SUCH AS 'WRITE THE SUM TO DISK' OR 'PLOT A SPECTRUM OUT'. BY TYPING 'OUT' WHILE IN DATA MANIPULATING MODE. CONTROL WILL BE RETURNED BACK TO MAIN. THEN THE MAIN PROGRAM ASKES THE USER WHETHER TO STOP. DISPLAY OR WANT ANOTHER RUN. 2. DATA STORAGE: ALL DATA FILES CONTAIN A ONE-BLOCK INFORMATION FIELD AS THE STARTING BLOCK AND A NUMBER OF SPECTRAL DATA SECTORS EACH OF WHICH IS A SINGLE SPECTRUM AND HAS SIZE AS A INTEGRAL NUMBER OF BLOCKS. THE INFORMATION FIELD DESCRIBES HOW MANY DATA THERE ARE IN THAT FILE. AND HOW THE DATA WERE OBTAINED. THE ORGANIZATION IS AS FOLLOWED: A. PARAMETER FIELD: (FIRST 60 BYTES) THERE ARE 7 ASCII PARAMETERS IN PRSENT.'THEY ARE: NUMBER OF SPECTRA IN THIS FILE SIZE OF EACH SPECTRUM IN NUMBER OF BLOCKS RATE OF SCAN IN MILLISEC PER POINT NUMBER OF SCANS PER SPECTRUM START POINT_NUMBER OF THE SPECTRUM (WHERE START SCANNING) NUMBER OF POINTS SCANNED PER SCAN STEP SIZE OF THE VOLTAGE OUTPUT EVERY PARAMETER IS LEFT ADJUSTED AND HAS FIXED LENGTH AS 4 BYTES. BLANKS WILL BE FILLED IN IF LESS THAN 4 BYTES. A COMMA AND A BLANK ARE USED TO SEPERATE TWO PARAMETERS. B. DESCRIPTION FIELD: (S3RD BYTES TO 127TH BYTES) THIS DESCRIPTION DESCRIBES BRIEFLY ABOUT THE SPECTRAL DATA, SUCH AS NAME OF COMPOUND. DATE OF EXPERIMENT ETC. DETAILED DOCUMENTATION IS TO BE WRITTEN IN ANOTHER DOCUMENTATION FILE BY THE USER. A DUMP FILE CALLED 'DK:SPEC.DMP' HAS BEEN CREATED IN THE DATA DISK FOR DUMPING THE INDIVIDUAL SCANS WHILE SCANNING. INFORMATION BLOCK WILL BE FILLED AFTER ALL SCANS ARE OVER. ' INDIVIDUAL DATA FILE CAN BE CREATED AND WRITTEN BY A 'WRITE' COMMAND IN THE DATA MANIPULATING MODE OF 'DISPLA'. DATA RETRIEVAL: DATA RETRIEVAL IS DONE WHILE THE CONTROL IS AT DATA MANIPULATING MODE OF 'DISPLA' BY A COMMAND 'BACK'. AFTER THE DATA ARE READ INTO MEMORY] FURTHER DATA MANIPULATION CAN BE PERFORMED. (THE DATA MANIPULATING MODE OF 'DISPLA' IS ENABLED BY KEYBORAO INTER RUPTED THE DISPLAYING PROCESS BY PRESSING 'ESC. A PRELIMINARY HANDLERl IN 'DISPLA'. UPON RECEIVING THIS SIGNAL. WILL CALL ANOTHER HANDLER To] GET AND INTERPRET A DATA MANIPULATING COMMAND('KYINHD')) .TITLE RECORD.MAIN . MCALL .PRINT. EXIT . GLOBL QUERY.DISPLA.PARAME.SCAN.SQUEEZ MACRO QUEST PRADDR.NOAODR MOV MOV JSR TSTB BEO . ENDM PRADDR.QUESAD #LIST1,R5 PC.QUERY ANSWER NOADDR PRINT A QUESTION WITH ADDRESS AS PRADDR IF ANSWER IS 'NO'. THEN BRANCH TO NOADDR ELSE CONTINUE DATA INITIALIZATION: CTCR-1 CTBR= 1 CKCR=1 CKBR=1 RAMP= 1 XOUT =1 YOUT =1 KEYCR= KEYBR= TTCR=1 JSW=44 67762 67774 70420 70422 70440 70444 70442 177560 177562 77564 COUNTER CONTROL REGISTER COUNTER BUFFER REGISTER REAL TIME CLOCK CONTROL REGISTER REAL TIME CLOCK BUFFER REGISTER RAMP OUTPUT BUFFER REGISTER X AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE Y AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE KEYBOARD INPUT CONTROL REGISTER KEYBOARD INPUT BUFFER REGISTER TERMINAL OUTPUT CONTROL REGISTER JOB STATUS WORD FOR .TTYIN. TTYOUT (SEE RT11 LC= . SET UP SYSTEM STACK)STACK_P0INTER=R6) . =200 *LC START MOV #START,SP MOV #STACK1,R4 CLEAR STACK 1 MOV #8192.,R3 STACK 1 CONTAINS 8K WORDS 1$: CLR (R4 ) + IT MAY ACCOMMODATE 1-4 SPECTRA SOB R3. 1$ MOV #1NF0T1,R4 INFOT N: INFORMATION TABLE ABOUT SPECT N MOV *4.R3 * INITIALLY IT CONTAINS 127 BLANK BYTES 2$: MOV #63..R2 AND BYTE 200 AS ITS END 3$: MOV BLANK.(R4)+ BLANK = 2 BLANK BYTES SOB R2 . 3$ MOV EOF. (R4 ) + EOF = BLANK BYTE + BYTE 200 SOB R3,2$ :ASK IF DATA RETRIEVAL IS DESIRED ? ASK 1 : QUEST #MSG1,GETPAR ;ASK: 'DATA RETRIEVAL?' ro cn IF NO, GOTO GET SCAN PARAMETERS IF YES. PASS CONTROL TO DATA RETRIEVAL ;PASS CONTROL TO DATA RETRIEVAL .PRINT #MSG2 ;PRINT 'PRESS 'ESC THEN TYPE IN 'BACK'.' MOV JSR #LIST3.R5 PC.DISPLA ; CALL DISPLA TO DISPLAY AND MANIPULATE ; THE DATA :GOTO SEE IF STOP ;DATA ACQUISITION: ; GET SCANNING PARAMETERS: GETPAR: MOV JSR SPACE: MOV MOV MOV CLRB 1$: MOV JSR TSTB BNE INC SOB #LIST2,R5 PC.PARAME #2.R4 *t.NEWNUM SIZEWD.NEWSIZ ERROR #LIST6,R5 PC.SQUEEZ ERROR ASK3 NEWNUM R4 . 1$ ; CALL PARAME TO GET SCAN PARAMETERS CALL SQUEEZ TO MAKE TWO SUITABLE HOLES FOR SPECT1 (CURRENT SCAN) AND SPECT2 (SUM) NEWNUM IS SPECTRUM # . NEWSIZ IS THE SIZE CLEAR ERROR IF ERROR OCCURRED. THEN SEE IF STOP ELSE DO FOR SPECT2 MOV JSR #LIST4.R5 PC.SCAN ; CALL SCAN TO SCAN THE SPECTRUM ALL SCANS WERE OVER. ASK IF MORE SCANS ARE DESIRED? QUEST #MSG3,STOSUM ASK: 'MORE SCANS?' IF NO. GOTO STORE THE SUM IF YES. CONTINUE AND GET MORE SCANS GET MORE SCANS: BIS #400.MODE INC BR NSCAN GETPAR SET A CONTINUOUS MODE TO KEEP SOME ACCOUNTING CONSTANTS IN 'SCAN'. GET ONE MORE SCAN (AS DEFAULT) GET PARAMETERS AND SCAN AGAIN ;STORE THE SUM: STOSUM: .PRINT *MSG4 : PRINT HOW TO GET THE SUM STORED :DISPLAY THE RESULT OSCILL: MOV MOV JSR #2.MODE #LIST3.R5 PC,DISPLA :CALL DISPLA TO DISPLAY THE RESULT ASK IF STOP: ASKS : QUEST .EXIT #MSG5,ASK4 ;ASK: 'STOP NOW?' IF NO. ASK IF DISPLAY IF YES. TERMINATE ASK IF DISPLAY: ASK4: QUEST #MSG6.ASK5 BR OSCILL ASK: 'WANT TO DISPLAY?' IF NO. ASK IF WANT ANOTHER RUN IF YES. GOTO TO DISPLAY THE RESULT AGAIN ASK IF WANT ANOTHER RUN: ASK5: QUEST 0MSG7.ASK3 JMP START ASK: 'WANT ANOTHER RUN?' IF NO. ASK IF STOP IF YES. GOTO TO START AGAIN DATA FIELD: LI ST 1 : WORD 2 CALL OUERYIQUESTION. ANSWER) QUESAD: . BLKW 1 MESSAGE ADDRESS ANSWER: . BLKB 1 RETURNED RESULT 1=YES. 0=N0 . EVEN LIST2: . WORD 5 CALL PARAME(RATE.NSCAN.START.END.STEP) RATE : WORD 200. INITIAL DEFAULT VALUES 200 MSEC PER POINT NSCAN: . WORD 20. 20 SCANS STARPT: . WORD 0 FROM POINT 0 NPOINT: . WORD 10O0. TO POINT 1000 STEP: . WORD 4 VOLTAGE STEP SIZE IS 4 SIZEWD. . WORD 1024 . MAX SIZEWD WORDS OF DATA LISTS: . WORD 7 CALL DISPLA . WORD MODE ACTIVITY OF EACH SPECTRUM SPTAD1 SPTAD2 SPTAD3 SPTA04 F LAGAD . WORD . WORD . WORD WORD . WORD . BLKW STACK 1 SPECT1 SPECT2 SPECT3 SPECT4 1 ADDRESS ADDRESS ADDRESS ADDRESS ADDRESS ADDRESS SPECT1 IS TO BE DISPLAYED SPECT2 IS TO BE DISPLAYED SPECT3 IS TO BE DISPLAYED SPECT4 IS TO BE DISPLAYED A NEW SCAN RESTART A TERMINATED JOB TO GET MORE SCAN (SEE SUBROUTINE SCAN) SCAN IS OFF SCAN IS ON (SPECT2 IS THE RESULT OF THE STATUS TABLE OF SPECTRUM 1 OF THE STATUS TABLE OF SPECTRUM 2 OF THE STATUS TABLE OF SPECTRUM 3 OF THE STATUS TABLE OF SPECTRUM 4 OF A FLAG FOR COMMUNICATION BETWEEN AND 'DISPLA' BIT 1 = 1 BIT 2 = 1 BIT 3 = 1 BIT 4 = 1 BIT 8 = 0 1 BIT 9 = 0 OF STACK ro LIST4: . WORD 3 CALL SCAN BEGIN1: WORD 4095 . POSITION OF 1ST POINT OF SPECT1 ON OSCILLISCOPE .WORD LIST2 HOW TO SCAN NPT 1 : . WORD 1000. # OF POINTS TO BE DISPLAYED . WORD LIST3 WHERE TO STORE IN MEMORY STEP 1 : . WORD 4 STEP SIZE OF THE VOLTAGE WORD LIST5 WHERE TO STORE IN DISK SIZW01: . WORD 1024 . SIZE OF THE WHOLE SPECT1 IN * OF WORDS INF01: . WORD INF0T1 ADDRESS OF THE INFO TABLE ABOUT SPECT 1 SCALE 1 : .WORD 1 VERTICAL SCALING FACTOR OF SPECT1 LIST5: .WORD 5 CALL DISK SEPER1: . WORD 0 SEPERATION BETWEEN BASELINE ANO SPECT1 .WORD FI LENA FILENAME ADDRESS HEAD 1 : . WORD STACK 1 ADDRESS OF THE HEAD OF SPECT1 DSTART: . WORD 0 STARTING BLOCK NUMBER START 1: . WORD 0 THE INITIAL START POINT # OF THIS SPECTRUM DADDR: WORD STACK 1 STARTING ADDRESS OF THE DATA FIELD TO BE USED DSIZE: . WORD 1024 # OF BLOCKS TO BE TRANSFERED D5TATU: .BYTE 0 STATUS: BIT 1=1 IF WRITE TO DISK SPECT2: .WORD STACK1+2048. ;ADDRESS OF 1ST POINT OF SPECT2 TO BE DISPLAYED EVEN BIT 1=0 IF READ FROM DISK BEGIN2: .WORD 4095 . POSITION OF 1ST POINT OF SPECT2 ON OSCILLISCOPE UPON RETURNED: NEGATIVE IF FAILED NPT 2 : WORD 1000. * OF POINTS TO BE DISPLAYED STEP2: WORD 4 STEP SIZE OF THE VOLTAGE SIZWD2: .WORD 1024 . SIZE OF THE WHOLE SPECT2 IN # OF WORDS FI LENA: .RAD50 /OK SPEC DMP/ ;DK:SPEC.OMP IS THE SCRATCH DATA FILE THAT INF02: WORD INF0T2 ADDRESS OF THE INFO TABLE ABOUT SPECT2 ; IS USEO TO STORE THE SCANNED RESULT. SCALE2: WORD 1 VERTICAL SCALING FACTOR OF SPECT2 ; SIZE = 33G BLOCKS SEPER2: WORD 0 SEPERATION BETWEEN BASELINE AND SPECT2 HEAD2: WORD STACK1+2048. :ADDRESS OF THE HEAD OF SPECT2 LISTG: WORD 6 CALL SOUEEZ TO SQUEEZE A HOLE FOR A NEW SPECTRUM START2: WORD 0 THE INITIAL START POINT # OF THIS SPECTRUM NEWNUM: .BLKW 1 SPECTRUM NUMBER OF THE NEW COMER MODAD: WORD MODE ADDRESS OF THE DISPLAY MODE NEWSIZ: BLKW 1 SIZE OF THE NEW SPECTRUM IN * OF WORDS SPECT3: WORD STACK 1+4096. ;ADORESS OF 1ST POINT OF SPECT3 TO BE DISPLAYED TABLSP: .WORD SPTAD1 TABLE OF ADDRESSES OF SPECTRUM STATUS TABLES BEGIN3: .WORD 4095 . POSITION OF 1ST POINT OF SPECT3 ON OSCILLISCOPE STKAO1: .WORD STACK 1 ADDRESS OF THE STACK 1 NPT3 : . WORD 1000. # OF POINTS TO BE DISPLAYED ERROR: BLKB 1 ERROR FLAG. SET IF ERROR OCCURRED UPON RETURNED STEP3: .WORD 4 STEP SIZE OF THE VOLTAGE SIZWD3: WORD 1024 . SIZE OF THE WHOLE SPECT3 IN # OF WORDS INF03: . WORD INF0T3 ADDRESS OF THE INFO TABLE ABOUT SPECT3 MSG 1 : ASCII /DATA RETRIEVAL7 /<200> SCALE3: .WORD 1 VERTICAL SCALING FACTOR OF SPECT3 SEPER3: . WORD 1000. SEPERATION BETWEEN BASELINE AND SPECT3 MSG2 : ASCIZ /PRESS 'ESC AND THEN TYPE IN 'BACK' TO GET DATA BACK./ HEADS: . WORD STACK1+4096. ;ADDRESS OF THE HEAD OF SPECT3 STARTS: . WORD 0 THE INITIAL START POINT * OF THIS SPECTRUM MSGS : ASCII /MORE SCANS? /<200> MSG4 : ASCII <12>/(T0 STORE THE SUM. PRESS 'ESC AND TYPE 'WRITE'.)/ SPECT4 : .WORD STACKH-6144. ; ADDRESS OF 1ST POINT OF SPECT4 TO BE DISPLAYED ASCII <12><1S>/(THE SUM IS IN SPECTRUM 2)/<12><15><12><200> BEGIN4: WORD 4095. POSITION OF 1ST POINT OF SPECT4 ON OSCILLISCOPE NPT4 : . WORD 1000. # OF POINTS TO BE DISPLAYED MSG5 : ASCII /STOP NOW? /<200> STEP4: WORD 4 STEP SIZE OF THE VOLTAGE SIZWD4: . WORD 1024 . SIZE OF THE WHOLE SPECT4 IN # OF WORDS MSG6 : .ASCI I /WANT TO DISPLAY? /<200> INF04: . WORD INF0T4 ADDRESS OF THE INFO TABLE ABOUT SPECT4 SCALE4: . WORD 1 VERTICAL SCALING FACTOR OF SPECT4 MSG7 : .ASCI I /WANT ANOTHER RUN? /<200> SEPER4: . WORD 1500. SEPERATION BETWEEN BASELINE AND SPECT4 . EVEN HEAD4: . WORD STACK 1+6 144. :ADDRESS OF THE HEAD OF SPECT4 START4: . WORD 0 THE INITIAL START POINT * OF THIS SPECTRUM BLANK: BYTE 40. 40 EOF : BYTE 40.2O0 INFORMATION TABLES: MODE : WORD 2 ;INITIAL VALUE OF MODE. SHOW SPECT2 ONLY INTOT1: BLKW 64 . THE INFORMATION TABLE ABOUT SPECT1 INF0T2: BLKW 64 . THE INFORMATION TABLE ABOUT SPECT2 INF0T3: BLKW 64 . THE INFORMATION TABLE ABOUT SPECT3 SZDATA: .WORD 40+256. +8192. ;SIZE OF THE DATA BANK INF0T4: . BLKW 64 . THE INFORMATION TABLE ABOUT SPECT4 EACH NFORMATION TABLE CONTAINS A PARAMETER FIELD (FIRST GO BYTES) :SPECTRUM STATUS TABLES: AND A DESCRIPTION FIELD (LAST 66 BYTES). A PARAMETER IN PARAMETER FIELD IS A LEFT ADJUSTED 4-BYTE ASCII DIGITAL STRING. SEPERATED WITH THE NEXT ONE BY A COMMA AND A BLANK SPECT1: . WORD STACK 1 ; ADDRESS OF THE 1ST POINT OF SPECT 1 TO BE DISPLAYED THE PARAMETERS ARE: 1. # OF SPECTRA IN THE FILE 2. SIZE OF EACH SPECTRUM IN BLOCKS 3. RATE OF SCAN IN mSEC 4. # OF SCAN OBTAINED FOR EACH SPECTRUM 5. POINT* OF THE 1ST POINT IN MEMORY 6. # OF POINTS ACTUALLY IN MEMORY 7. STEP SIZE WHILE SCANNING THIS SPECTRUM THREE MORE PARAMETERS MAY BE APPENDED THE DESCRIPTION IS USED TO CLARIFY THE SPECTRUM. ;MEMORY FOR THE SPECT STACK 1: BLKW 8192. THE FIRST SIZWD1 THE NEXT SIZWD2 THE NEXT SIZWD3 THE NEXT SI ZWD4 WORDS MAKE UP SPECT1 WORDS MAKE UP SPECT2 WORDS MAKE UP SPECT3 WORDS MAKE UP SPECT4 END OF MAIN PROGRAM RECORD END START ro CTi 10 ; SUBROUTINE ADDSUB VERSION 1.2 27-MAR-8 1 FUNCTION OF THIS SUBROUTINE I S TO PERFORM ADDITION / SUBTRACTION BETWEEN TWO I SPECTRA. THE RESULT CAN BE A NEW SPECTRUM OR PART OF THE EXIST I N G ONE. ITHE PARAMETER L I S T PASSED TO THIS SUBROUTINE I S : : L I S T : .WORD 10. ;CALL A DATA MANIPULATING SUBROUTINE ;SAVE: ; .BLKW 1 ; ADDRESS OF PARAMETER LI S T TO CALL 'DISPLA' : (JUST USED FOR FURTHER MODIFICATION) ;XCUR: WORD 40 9 5 . ;X COORDINATE OF THE CURSOR ;¥CUR: WORD 0 ;Y COORDINATE OF THE CURSOR ;FACTOR: WORD 0 :SCALE FACTOR USED FOR DISPLAY ;MODE: .BLKW 1 ; THE DISPLAY MODE :SPTAD1: .BLKW 1 •ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 ;SPTAD2: BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 ;SPTAD3: BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ;SPTAD4: .BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 :STKAD1: BLKW 1 ;ADDRESS OF STACK 1 USED TO STORE THE SPECTRA ;THE SUB ROUTINE ASKS F 3R THE FOLLOWING INPUTS: 1. 3 SPECTRUM LUMBERS: FOR THE TWO OPERANDS AND THE SUM. FIRST ONE CANNOT BE DEFAULTED. THE DEFAULT FOR THE OTHERS I S ITS PRECEDING VALUE. 2 3 START POINT#'S. NUMBER OF POINTS AND SIGN: THE DEFAULT CONDITION I S THE SAME AS IN 1. FOR THE 3 START_ POINT#'S. NO DEFAULT FOR NUMBER OF POINTS. THE DEFAULT FOR I S ' + ' . .TITLE ADD_SUBSTRACT .GLOBL ADDSUB.EXTRAC.BINARY,QUERY.SQUEEZ.CHARAC .MCALL .PRINT ADDSUB: MOV R5,SAVE ADD #12.R5 ;R5 POINTS TO MODE MOV R5.M0DAD ;MODAD = ADDRESS OF MODE ADD #2.R5 ;R5 POINTS TO SPTAD1 MOV R5.TABLSP ;TABLSP = ADDRESS OF TABLE OF S P T A D N MOV 10( R5).STKAD 1 ;STKAD1 = ADDRESS OF STACK 1 INPUT 1: MOV #LIST1.R5 ;ASK FOR SPECT# OF A.B.C JSR PC.EXTRAC CMPB ARGU1.#200 ; I F FIRST ONE DEFAULT BEQ INPUT 1 : THEN ASK AGAIN CMPB ARGU2.#200 ;IF SECOND ONE IS NOT DEFAULT BNE 1$ ; THEN JUST CONTINUE MOV ARGU1.ARGU2 ; ELSE ASSUME SECOND ONE = FIRST ONE 1$ : CMPB ARGUS.#200 : I F THIRD ONE IS NOT DEFAULT BNE 2$ ; THEN JUST CONTINUE MOV ARGU2.ARGUS ; ELSE ASSUME THIRD ONE = SECOND ONE 2$: MOV #ARGU1,R5 CALCULATE SPTADA.SPTADB,SPTADC, INFOTC MOV *SPrADA.R4 ;AND STORE THEM #3 . R3 B I C MOV DEC ASL ADD ADD MOV # 1 7 7 7 6 0 . ( R 5 ) ( R5 )-» . R2 R2 R2 SAVE,R2 #14.R2 ( R 2 ) . ( R 4 ) + R3.3$ ( R 2 ) , R 2 1 2 ( R 2 ) . I N F O T C (R5)=SPECT# I N A S C I I R2=SPECT# I N BINARY : R2=0FFSET OF SPTADN TO SPTAD1C : R2=#SPTADN :R2 POINTS TO SPTADC ;INFOTC POINTS TO INFO TABLE OF SPECTC ;GET STEP S I Z E : GETSTP: MOV MOV MOV MOV MOV MOV SPTADC.R4 SPTADB,R3 SPTADA.R2 6 ( R 2 ) . S T E P A 6 ( R 3 ) . S T E P S STEPA.STEPB 1$ SPECT» OF THE :R4=#SPECT_N OF C :R3=#SPECT_N OF B :R2=#SPECT_N OF A ;STEPA: S T E P _ S I Z E OF A ;STEPB: S T E P _ S I Z E OF B : I F STEPA < STEPB NEW SPECT CLR DI V TST BNE ASL MOV MOV S T E P B . R l R1 . S T E P C RO STEPA.RO R1 ERSTEP RO RO.STEPA #2 . S T E P B INPUT2 THEN STEPC=STEPB IF STEPB ISN'T MULTIPLE OF STEPA THEN ISSUES AN ERROR MESSAGE ; ELSE STEPA=2*THE MULTIPLE # ; STEPB=2 : (STEPA.B ARE USED TO STEP THRU THE MEM) ; (EVERY POINT OF B WILL BE USED. FOR A) :(ONLY MULTIPLE # POINTS WILL BE SKIPPED) MOV MOV CLR DI V TST BNE ASL MOV MOV STEPA.R1 R1.STEPC RO STEPB.RO R 1 ERSTEP RO RO.STEPB #2.STEPA INPUT2 E STEPC=STEPA IF STEPA ISN'T MULTIPLE OF STEPB THEN ISSUES AN ERROR MESS ELSE STEPB=2*THE MULTIPLE # STEPA=2 (STEPA,B ARE USED TO STEP THRU THE MEM) (EVERY POINT OF A WILL BE USED. FOR B) (ONLY MULTIPLE # POINTS WILL BE SKIPPED) :STEP S I Z E ERSTEP: MOV MOV JSR TSTB EM: *MSG3.QUESAD #LIST3.R5 PC,QUERY ANSWER 1$ F I N I S H INPUT 1 :ASK: F A I L E D TO MAKE STEP_SIZE_A AND STEP_ ; S I Z E B COMPATIBLE. TRY AGAIN?' IF 'YES' THEN GOTO INPUT' ELSE TERMINATE (TOO LONG TO USE BRANCH) ro o NPUT2: MOV JSR *LIST11.R5 PC,EXTRAC ; INPUT START POINT* OF A, B. C. NPOINTS, SIGN CMPB BEO CMPB BNE MOV MOV MOV CMPB BNE MOV MOV MOV CMPB BEO ARGU4.*200 INPUT2 ARGU5.*200 1$ ARGU4,ARGU5 ARGU4+2,ARGU5+2 ARGU4+4,ARGU5+4 ARGU6.#200 2$ ARGU5,ARGU6 ARGU5+2.ARGU6+2 ARGU5+4,ARGU6+4 ARGU7,#200 INPUT2 IF DEFAULT THE FIRST ONE THEN ASK AGAIN IF NOT DEFAULT THE SECOND ONE THEN JUST CONTINUE ELSE ASSUME THE SECOND ONE = THE FIRST ONE IF NOT DEFAULT THE THIRD ONE THEN JUST CONTINUE ELSE ASSUME THE THIRD ONE ; IF DEFAULT NPOINT ; THEN ASK AGAIN SECOND ONE MOV #ARGAD4,R4 ;CONVERT ARGU4.5.6.7 TO BINARY MOV #ADDRA.R2 MOV #4.R3 MOV (R4)+,STRGAD :STRGAD = ADDRESS OF THE DIGITAL ASCII ARGU MOV #LIST2.R5 ;CALL BINARY JSR PC.BINARY ;BINARY NUMBER STORED AS AODRA.ADDRB.ADDRC. AND NPOINT MOV BINUM.(R2)+ SOB R3.3$ MOV #4095..BEGINC :SET RELATIVE POSITION OF SPECTC ON OSCILL. SUB ADDRC.BEGINC :CHECK IF TO KEEP THE EXISTING PART OF SPECT_C OR NOT : EXIST: MOV #MSG2.OUESAD ;ASK: 'WANT TO KEEP THE OTHER PARTS OF OLD MOV #LIST3.R5 ; SPECTC? ' JSR PC.QUERY TSTB ANSWER ;IF 'YES- . BNE KEEP ; THEN KEEP THE OTHER PARTS ;D0 NOT KEEP THE EXISTING PART NOKEEP: MOV NPOINT.R5 : ELSE TREAT IT AS A NEW SPECTRUM CLR R4 DIV #256.,R4 TST R5 BEO 1$ INC R4 ;R4 = # OF BLOCKS TO KEEP NPOINT IS: ASH #8.,R4 ;R4 = NEW SIZE IN » OF WORDS MOV R4.NEWS IZ CLRB ERROR MOV #LIST4,R5 JSR PC.SQUEEZ •.CALL SQUEEZ TO GET A HOLE FOR THIS SPECTRUM TSTB ERROR ;IF NO ERROR OCCURRED BEO UPDAT1 ; THEN CONTINUE JMP FINISH : ELSE STOP UPDAT1: MOV. SPTADC,R4 ;UPDATE THE SPECTRUM STATUS TABLE MOV 20(R4).(R4> + ;SPECT_C = HEAD_C MOV #4095..(R4) SUB ADDRC.(R4)+ ;BEGIN C = 4095. - STARTPOI NT»_C MOV NPOINT.(R4)* ;NPOINT MOV STEPC,< R4 )* STEP SIZE MOV NEWSIZ.(R4 )* SIZE IN # OF WORDS ADO #2 . R4 INFO DOES NOT CHANGE MOV #100..(R4)* (SCALE FACT0R)MOO - 100 CLR (R4 ) + SEPERATION = 0 MOV ADDRC.2(R4) STARTC = START_POINT#_C ;UPDATE INFORMATION TABLE: MOV SPTADC.R4 R4 POINTS TO STATUS TABLE AGAIN MOV #ARGU4.R2 SET UP A TABLE CONTAINING THE INFO PARAMETERS IN THE RIGHT ORDER (USE ARGU4 AS BUFFER) MOV # 1 .(R2) + 1 . # SPECT = NSCAN MOV 10(R4I.R0 2. SIZE IN # OF BLOCKS ASH #-8..RO 1 BLOCK = 256 WORDS MOV RO.(R2)+ CLR <R2) + 3. RATE (UNKNOWN) CLR ( R2 )* 4. NSCAN (UNKNOWN) MOV 22(R4).(R2)* 5. START POINT* MOV NPOINT.(R2)* 6. NPOINT MOV STEPC.(R2) 7. STEP MOV INF0TC.R4 INF01=ADDRESS OF INFO BLOCK OF SPECTC MOV #ARGU4.R2 CONVERT THESE TO ASCII CHARACTERS MOV #7 .R3 R3 = PARAMETER COUNT BLANKS: MOV #64..R1 BLANK OUT THE INFO_TABLE(64 WORDS) MOV R4 . R5 1$: MOV BLANK.(R5) + SOB R 1 . 1$ 13$ : MOV #LIST5.R5 CALL CHARAC MOV (R2)+.NUMBER NUMBER = BINARY NUMBER TO BE CONVERTED JSR PC.CHARAC MOV #4 . RO RO = BYTE COUNT (4 BYTES FOR EACH) MOV #CHAR4,R1 12$ : CMPB #200.1 R1 > 200 INDICATES END OF CHAR4 BNE 10$ MOVB #40.(R4)+ PUT BLANKS UNTIL GOT 4 CHAR'S BR 1 1$ 10$ : MOVB (R1)+,(R4) + 1 1$ : SOB RO.12$ .CONVERTS AND STORES 4 DIGITS MOV COMMA.(R4 ) + :PUT A COMMA AND A BLANK AT THE END SOB R3.13$ ;REPEAT UNTIL 7 PARAMETERS ARE DONE JMP OPERAT ;GOTO DO THE OPERATION ;KEEP THE EXISTING PART: KEEP : MOV SPTADC.R4 ;R4 POINTS TO THE STATUS TABLE OF SPECTC CMP STEPC.6(R4) ;IF NEW STEP SIZE = OLD STEP SIZE BEO STEPOK ; THEN CONTINUE PRINT #MSG2.1 ; ELSE COMMAND ABORTED AND STOP JMP FINISH STEPOK: MOV 12 ( R4 ) , R 1 :R1 POINTS TO THE INFO TABLE ADD #30..Rl ;R1 POINTS TO NPOINT IN THE INFO TABLE MOV R1.STRGAD •CONVERT THIS ORIGINAL NPOINT TO BINARY MOV #4 .RO '.THE MAX SIZE OF THIS PARAMETER IS 4 BYTES 1$: CMPB #40,(Rl)+ ;USE #200 TO END THE DIGITAL STRING BEO 2$ SOB RO. 1$ 2$: MOVB -(R1),R2 ;STORE THIS ENDING BYTE MOVB #200.(Rl) ;SET #200 AS THE END OF;THE DIGITAL STRING MOV #LIST2.R5 JSR PC.BINARY MOV BINUM.OLONPT ;OLDNPT = ORIGINAL NPOINT OF THE SPECTC MOVB R2.(R1) ;RESTORE THE ORIGINAL BYTE DIFFER: MOV ADDRC.R1 ;R1 = START_POINT#_C CLR RO SUB 22(R4).R1 ;R1 = NEW START - OLD START BGE 1* :IF POSITIVE, THEN CONTINUE BIS #177777,RO ; ELSE EXTEND THE SIGN BIT TO RO 1$: DIV G(R4),R0 ;R1=R1/5TEP C MOV RO.DIFFST ;DIFFST = # OF POINTS AHEAD BGE BEHIND :IF RO > 0, NEW SPECT STARTS BEHIND THE OLD ; THE SUM STARTS IN FRONT OF THE EXISTING PART FRONT: NEG DIFFST ;DIFFST IS POSITIVE NOW MOV 10(R4).NEWSIZ INITIALIZE NEWSIZE = OLDSIZE MOV OLDNPT ,R1 ;R1 = TOTAL # OF POINTS OF SPECTC IN MEM ADD DIFFST . R 1 ;R1 = NEW TOTAL # OF POINTS OF SPECTC CMP NPOINT ,R1 : IF NPOINT TO BE ADDED IS LESS THAN THIS BLE ADJSZ1 THEN OK BECAUSE SOME OLD PART EXISTS PRINT #MSG6 ELSE PRINT 'TO MANY POINTS' JMP FINISH AND STOP ADJSZ1: CMP 10( R4 ) ,R1 : IF OLD SIZE > SIZE TO STORE NEW SPECT BGE 3$ THEN JUST MOVE DOWN THE OLD SPECTC CLR RO DIV #256..RO TST R1 BEO 1« INC RO ;R0 = SIZE IN BLOCKS TO STORE NPOINT 1$ : ASH #8..RO :R0 = SIZE IN WORDS MOV RO.NEWSIZ ;NEWSIZ - NEW SIZE OF THE SPECT_C CLRB ERROR MOV #LIST4 . R5 JSR PC.SOUEEZ ;CALL SOUEEZ TO GET A HOLE FOR SPECTC TSTB ERROR BEO 3» ; IF NO ERROR OCCURRED. THEN CONTINUE JMP FINISH ELSE STOP 3$ : MOV OLDNPT .RO ASL RO ;R0 - OLD SIZE IN BYTES ADD 20(R4) .RO ;R0 = ADDRESS OF THE BOTTOM OF THE OLD SPECT MOV DIFFST .Rl ASL R 1 ;R1 - THE SIZE AHEAD OF THE OLD SPECT IN BYTES ADD R0.R1 ;R1 = NEW ADDR OF BOTTOM OF THE OLD SPECT MOV OLDNPT ,R2 :MOV DOWN THE OLD SPECT TO ACCOMMODATE THE NEW DOWN: MOV -(RO). -(R1 ) SOB R2.DOWN CLEAR: MOV DIFFST .RO 1$ : CLR -(R1 ) ;CLEAR THE HOLE SOB RO. 1$ UPDAT 2 : MOV 2 0 ( R 4 ) , ( R 4 ) SPECTC = HEADC MOV #4095. .2(R4 ) SUB ADDRC.2(R4) BEGIN C = 4095. - START POINT* C MOV OLDNPT.4(R4) NPOINT « OLDNPOINT + DIFFST ADD DIFFST.4(R4) MOV NEWSIZ. 10(R4 ) NEW SIZE MOV ADDRC . 22( R4 ) STARTC = START_POINT*_C INF02: MOV INFOTC.R3 UPDATE THE INFO TABLE ADD #24.,R3 R3 POINTS TO THE FIFTH ENTRY OF INFO TABLE MOV #ARGU6,R2 R2 POINTS TO THE ASCII START POINT* OF SEPCTC MOV BLANK,(R3) CLEAR THE OLD 4 BYTE PARAMETER FIRST MOV BLANK.2(R3) 1$: MOVB (R2)*.(R3)+ MOVE IN ASCII DIGIT CMPB #200,(R2) UNTIL THE END OF ASCII DIGITAL STRING BNE 1$ BR INF03 GO TO UPDATE THE REST OF THE INFO. TABLE :THE SUM STARTS BEHIND THE EXISTING PART: BEHIND: MOV NPOINT.R1 ADD DIFFST.R1 Rl = SIZE OF NEW SPECT IN WORDS CMP OLDNPT.R1 IF OLD NPOINT > NEW COMING PART BGE OPERAT THEN JUST GO TO DO THE OPERATION MOV Rl ,4(R4) ELSE SET THE NEW NPOINT = THE LARGER ONE CMP 10(R4 ) . R 1 IF OLD SIZE > NEW SIZE BGE UPDNPT THEN GOTO UPDATE THE NEW NPOINT CLR RO DIV #256..RO TST R 1 BEO 1$ INC RO RO => SIZE IN # OF BLOCKS 1$ : ASH #8..RO RO « SIZE IN # OF WORDS MOV RO.NEWSIZ CLRB ERROR MOV #LIST4,R5 CALL SOUEEZ TO GET A HOLE FOR THE NEW SPECT JSR PC.SOUEEZ TSTB ERROR BNE FINISH IF ERROR OCCURRED, STOP UPDAT 3: MOV 20(R4).(R4) SPECTC - HEAO_C MOV #4095..2(R4) SUB 22IR4).2(R4) BEGIN C = 4095. - START C MOV NEWSIZ.10(R4) SIZE_C = NEWSIZ INF03: MOV INFOTC,R3 UPDATE INFO TABLE ADO #6.R3 R3 POINTS TO SECOND ENTRY OF INFO TABLE OF C MOV NEWSIZ.Rl ASH #-8.,R1 NEW SIZE IN BLOCKS MOV R1.NUMBER CONVERT TO ASCII CLRB FLAG CLEAR FLAG. FLAG SET IF NO MORE CONVERSION CONLP: MOV #LISTS.R5 JSR PC.CHARAC CONVERSION MOV #CHAR4.R2 MOV BLANK.(R31 CLEAR THIS ENTRY MOV BLANK.2(R3I 1$: MOVB IR2 >*.(R3 )* MOVE IN DIGIT CMPB # 2 0 O . ( R 2 ) UNTIL BYTE 200 IS ENCOUNTERED BNE It TSTB FLAG FLAG SET IF NO MORE CHARAC CALL BNE OPERAT UPDNPT: MOV INFOTC,R3 UPDATE THE NEW NPOINT IN INFO TABLE ADD #30.,R3 R3 POINTS TO SIXTH ENTRY (# OF POINTS) MOV 4(R4),NUMBER NEW NPOINT INC FLAG SET FLAG TO INDICATE IT IS THE END OF CONVER. BR CONLP ;ACTUAL ADDITION / SUBTRACTION: OPERAT: MOV #SPTADA,R5 CALCULATE STARTING ADDRESS OF EACH SPECT MOV #ADDRA,R4 STORE THEM TO ADDRA.ADDRB.ADDRC AND GET A COPY OF SEPERA. SEPERB. AND SEPERC MOV #3,R3 ADDRLP: MOV (R5)+.R2 R2=#SPECT_N FOR A.B.OR C MOV (R4),R1 SUB 22(R2),R1 R1 = PRESENT START POINT* - ORIGINAL ONE BLT 1* IF NEGATIVE, SET START POINT* TO ORIG. ONE ASL R1 R1 IS NOW IN BYTES CLR RO DIV 6(R2).RO RO=START_POINT#_N/STEP_N BR 2$ i t : PRINT #MSG4 PRINT ERROR MESSAGE. BUT CONTINUE CLR RO PRESENT START POINT* = ORIGINAL ONE 2t : ADD 20(R2),RO RO=RO+HEAD N MOV RO.(R4)+ ADDR N = RO. STORE TO ADDRA, ADDRB. OR ADDRC MOV 16(R2).6(R4) GET A COPY OF SEPERATIONS. STORE AFTER NPOINT SOB R3.ADDRLP MOV ADDRA.R5 R5 POINTS TO SPECTA MOV ADDRB.R4 R4 POINTS TO SPECTB MOV ADDRC.R3 R3 POINTS TO SPECTC MOV NPOINT,R2 R2 IS THE POINT COUNTER MATHLP: MOV (R4).R1 RI'POINT VALUE OF B SUB SEPERB,R1 RESET THE SEPERATION FROM BASELINE CMPB ARGU8,#'+ IF ADDITION BEO 2$ THEN C - A + B CMPB ARGU8.#'- IF SUBTRACTION BEO 1$ THEN C = A - B CLR R1 ELSE C = A BR 2$ 1$: NEG R1 2$: ADD (R5).RI CALCULATE C SUB SEPERA,R1 RESET THE SEPERATION FROM BASELINE ADO SEPERC.R1 SET THE SEPERATION FROM BASELINE FOR SPECTC MOV R1.(R3)+ RESTORE THE RESULT TO SPECTC ADD STEPA.RS SKIP 'STEPA' POINTS FOR SPECTA ADD STEPB.R4 SKIP -STEPB/2' POINTS (1 POINT = 2 BYTES) SOB R2,MATHLP SET THE DISPLAYING MODE TO DISPLAY THE SUM: MOVB ARGU3.R5 ;SET BIT_N OF MODE IN SUBROUTINE DISPLA DECB R5 MOV #1.R4 ; ASH BIS R5.R4 R4.9M0DAD JOB DONE: FINISH: .PRINT RTS #MSG5 PC DATA FIELD: . BLKB . EVEN LIST4: . WORD 6 NEWNUM: . BLKW 1 MODAD: . BLKW 1 NEWSIZ: BLKW 1 TABLSP: . BLKW t STKAD1: . BLKW I ERROR: .BLKB 1 :BIT N OF R4 IS NOW SET ;SET THE MODE TO DISPLAY SPECTC :PRINT 'COMMAND 'ADDSUB' FINISHED. : RETURN SAVE : BLKW 1 LIST 1: .WORD 4 ;CALL EXTRAC TO INPUT 3 SPECT#'S MESAD: WORD MSG 1 ;ADDRESS OF THE MESSAGE ARGAD1: WORD ARGU 1 ;ADDRESS OF THE ARGUMENTS ARGAD2: WORD ARGU2 ARGAD3: .WORD ARGU3 ARGU1: BLKW 1 ;BUFFER FOR THE ASCII SPECT#'S ARGU2: .BLKW 1 ARGUS: .BLKW 1 LIST1 1 WORD 6 CALL EXTRAC TO INPUT 3 START POINT*'S.NPOINT . WORD MSG 1. 1 AND THE SIGN ARGAD4 WORD ARGU4 ADDRESS OF THE ARGUMENTS ARGAD5 . WORD ARGU5 ARGAD6 . WORD ARGUS ARGAD7 . WORD ARGU7 ARGAD8 . WORD ARGU8 ARGU4: . BLKW 3 BUFFER FOR THE 3 ASCII START _POINT#'S ARGU5: . BLKW 3 ARGUS: BLKW 3 ARGU7: BLKW 3 BUFFER FOR THE ASCII NPOINT ARGU8: BLKW 1 BUFFER FOR THE ASCII SIGN LIST2: . WORD 2 CALL BINARY STRGAD BLKW 1 ADDRESS OF ASCII STRING BINUM: . BLKW 1 BINARY EQUIVALENCE LISTS: .WORD 2 CALL QUERY OUESAD BLKW 1 ADDRESS OF THE QUESTION ANSWER 1=YES 0=N0 THE SPECTRUM # OF THE INCOMING SPECTRUM ADDRESS OF MODE SIZE OF THE NEW SPECTRUM TABLE OF ADDRESSES OF SPECTRUM STATUS TABLES ADDRESS OF STACK 1 ERROR FLAG. SET IF ERROR OCCURRED ro CO EVEN ; END OF SUBROUTINE ADDSUB ; . END LIST5: . WORD 2 ;CALL CHARAC TO CONVERT BINARY TO ASCII . * • . . . * » * + *»••,.•«.» + • * . * * * . * * • * • * • * . * • • • • * • • • * • * . • • • * * * • * * • • * • » * • • * • « • • * * • • • • * NUMBER .BLKW 1 •> ;BINARY NUMBER — — — — — — — ^ — — — — f WORD CHAR4 ;THE ASCII STRING ADORESS FLAG: . BLKB 1 ;A FLAG SET IF NO MORE CHARAC CALL SIGN: . BLKB 1 ;SPACE FOR SIGN RETURNED IF ANY CHAR4: .BLKW 3 ;SPACE FOR THE DIGITAL PART RETURNED MSG1 : .ASCII ; FOR C = A + /- B,; ASCII <12><15>/INPUT SPECT* FOR A, B. C: /<200> MSG 1 . 1 ASCII / START POINT* FOR A, B. C. #_OF_POINTS. SIGN : /<200> MSG2: ASCII <12>/WANT TO KEEP THE OTHER PARTS OF OLD SPECT_C? / .BYTE 200 MSG2.1 ASCII /THE NEW STEP SIZE IS NOT COMPATIBLE TO THE OLD ONE. / ASCIZ /COMMAND ABORTED./ MSGS : ASCII /FAILED TO MAKE STEP SIZE_A AND STEP_SIZE_B COMPATIBLE. / ASCII /TRY AGAIN? / BYTE 200 MSG4 : ASCIZ /THE DESIRED START_POINT* IS TOO SMALL. SET TO MINIMUM NOW./ MSG5: ASCIZ /COMMAND 'ADDSUB' FINISHED. BACK TO DISPLAY./ MSG6: .ASCIZ /ppp NPOINT TOO LARGE. COMMAND ABORTED./ . EVEN BLANK: ASCII / / COMMA: .ASCII /. / SPTADA . BLKW 1 ; #SPECT N OF A SPTADB BLKW 1 ;#SPECT N OF B SPTADC .BLKW 1 ;#SPECT_N OF C INFOTC BLKW 1 ;ADDRESS OF INFO TABLE OF SPECTC STEPA: .BLKW 1 ;STEP SIZE OF A STEPB: BLKW 1 ;STEP SIZE pF B STEPC: BLKW 1 ;STEP SIZE OF C ADDRA: BLKW 1 -.ADDRESS OF THE START POINT OF SPECTA ADDRB: .BLKW 1 :ADDRESS OF THE START POINT OF SPECIE ADDRC: BLKW t ;ADDRESS OF THE START POINT OF SPECTC NPOINT BLKW 1 :# OF POINTS SEPERA BLKW 1 ;SEPERATI ON FROM BASELINE FOR SPECTA SEPERB BLKW 1 :SEPERATION FROM BASELINE FOR SPECTB SEPERC . BLKW 1 ;SEPERATION FROM BASELINE FOR SPECTC BEGINC BLKW 1 :POSITI0N OF SPECTC ON OSCILLISCOPE OLDNPT BLKW 1 ;THE ORIGINAL NPOINT STORED IN INFO TABLE DIFFST BLKW 1 DIFFERENCE BETWEEN OLD AND NEW START_POINT# ro \ i ; READ IN THE INFORMATION BLOCK OF THE DATA FILE AND GET INFOMATION: ************** ***************** ••A******************************************* INFOIN : MOVB ARGU1,R4 R4-N FOR SPECT N SUBROUTINE BACK VERSION 1.1 1-MAR-8 1 BIC #177760.R4 CONVERT TO BINARY MOV R4,NEWNUM NEWNUM IS THE SPECT # OF THE INCOMING ONE ************** *************************************************************** DEC R4 THE FUNCTION OF THIS SUBROUTINE IS TO READ BACK DATA ON DISK ASL R4 ADD #SPTAD1,R4 R4=#SPTAD N THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: MOV (R4).SPTADN SPTADN = STATUS TABLE FOR SPECTN MOV (R4),R3 LIST: WORD 10. CALL A DATA MANIPULATING SUBROUTINE MOV 12(R3),R3 R3=INFOAD_N SAVE : BLKW 1 ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' MOV R3.DADDR (JUST USED FOR FURTHER MODIFICATION) XCUR: WORD 4095 . X COORDINATE OF THE CURSOR MOV #64..DSIZE INPUT THE FIRST 128 BYTES OF THE DATA FILE VCUR : . WORD 0 Y C00RDINA1E OF THE CURSOR CLRB DSTATU FACTOR .WORD 0 SCALE FACTOR USED FOR DISPLAY CLR DSTART INFO_TABLE_N MODE : BLKW 1 THE DISPLAY MODE MOV #LIST3.R5 SPTAD1 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT 1 JSR PC.DISK SPTAD2 .BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 TSTB DSTATU IF DISK OPERATION OK SPTAD3 .BLKW 1 AODRESS OF SPECTRUM STATUS TABLE OF SPECT3 BEO SHOWIN THEN CONTINUE TO SHOW INFORMATION TABLE SPTAD4 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 JMP FINISH ELSE STOP STKAD1 . BLKW ADDRESS OF STACK 1 USED TO STORE THE SPECTRA ; SHOW THE INFORMATION TABLE OF THE DATA IN THE DATA FILE ************** *************************************************************** .TITLE DATA BACK FROM DISK SHOWIN : MOV #MSG3.R5 R5 POINTS TO THE MESSAGE TO BE OUTPUT .GLOBL EXTRAC.QUERY.DISK.BACK.BINARY.SQUEEZ,FNAME MOV #7 . RO PRINT THE 7 PARAMETERS .MCALL PRINT 1$: ADD #18..R5 R5 POINTS TO THE POSITION OF THE NUMBER MOV ( R3 )+ . ( R5 )+• MOVE THE ASCII NUMBER TO THE MESSAGE BACK : MOV R5,SAVE SAVE THE LINK MOV (R3)+.(R5)+ ADD #12.R5 ADD #2 . R5 SKIP TWO BYTES (LINE FEED AND RETURN) MOV (R5I+.M0DE ;GET A COPY OF THE PARAMETERS AOD #2 . R3 SKIP TWO BYTES (COMMA AND BLANK) MOV (R5)+.SPTA01 SOB RO. 1$ MOV <R5)+.SPTAD2 .PRINT #MSG3 PRINT (# SPECT.SIZE.RATE.. STEP SIZE ARE:) MOV (R5)+.SPTA03 ADD #20.,R3 R3 POINTS HEAD OF THE DESCRIPTION MOV (R5)+.SPTAD4 .PRINT #MSG4 PRINT DESCRIPTION MOV <R5).STKAD1 PRINT R3 SHOW THE CURRENT STATUS ON DISPLAY: ;SEE IF IT IS THE RIGHT THING: C URRNT: PRINT #MSG1 OUTPUT SPECT#S OF CURRENTLY DISPLAYED SPECTRA MOV #MSG5,QUESAD ASK:'WANT TO SEE IT?' MOV #0NE.R5 R5 POINTS TO TABLE CONTAINING SOME NUMBERS MOV #LIST4,R5 MOV #1 ,R3 R3 USED TO TEST IF SPECT N IS IN JSR PC.QUERY MOV #4.R2 LOOP 4 TIMES TSTB ANSWER IF 'YES' CURIN: BITB R3,MODE IF BIT_N=0. SPECTN NOT IN BNE PROCED THEN PROCEED BEO NOT IN MOV #MSG6.QUESAD ELSE PRINT R5 JSR PC.QUERY ASK:'TRY ANOTHER ONE' NOT IN: ADD #4 . R5 (4 BYTES FOR EACH NUMBER) TSTB ANSWER IF 'YES' ASL R3 BNE BEGIN THEN TRY AGAIN SOB R2.CURIN JMP FINISH INPUT FILENAME OF THE DATA FILE AND THE SPECTRUM NUMBER OF THE NEW SPECTRUM : DATA FILE OK, GET DISPLAYING STATUS FROM INFORMATION BLOCK: E EGIN: MOV #LIST1,R5 INPUT SPECT*.FILENAME PROCED : MOV DADDR.R3 R3 POINTS BACK TO INFO TABLE JSR PC.EXTRAC MOV #5.R2 CONVERT THE PARAMETERS TO BINARY (SKIP SCAN RATE AND # OF SCANS) MOV #NSPECT.R1 Rl POINTS TO A TABLE TO STORE THESE 5 #'S MOV •ARGU2.FNAMAO CONVERT FILENAME TO RAD50 MOV •STRING.R4 R4 POINTS TO A BUFFER STRING MOV #LIST2.R5 1 MOV R4.STRGAD JSR PC.FNAME MOV #LIST5.R5 CONVERT THESE 3 PARAMETERS TO BINARY BLOOP: MOV R3.R0 ;MOVE THE STRING TO THE BUFFER MOV STRGAD.R4 2% • CMPB (RO).#40 ;IF A BLANK OR A COMMA BEO 1 $ THEN REPLACE IT WITH '200' TO ACT AS CMPB (R0).#' . : END OF STRING BEO 1 $ MOVB (R0)+.(R4)+ ; ELSE COPY THIS BYTE TO BUFFER STRING BR 2$ 1 $ : MOVB #200.(R4) JSR PC.BINARY ;CALL BINARY TO CONVERT THE BUFFER TO BINARY MOV NUMBER.<R1 )* :STORE AS STARTP.NPOINT.STEP ADD #6.R3 ;(6 BYTES FOR EACH PARAMETER IN INFO TABLE) CMP #4.R2 ;IF NEXT ONE IS SCANRATE (THE THIRD) BNE 3$ ADD #12..R3 : THEN SKIP THE NEXT TWO 3$: SOB R2.BLOOP ; ELSE CONTINUE ;INPUT THE DATA FROM DATA FILE INBLKN: CMP #1.NSPECT ;IF THERE IS ONLY ONE SPECTRUM BNE INPUT2 ; THEN GO TO ASK WHICH SPECT TO BE IN MOV #1,DSTART ; ELSE START BLOCK* IS ONE BR ADJSZ ; AND GO TO ADJUST THE SIZE OF MEM INPUT2: MOV #LIST6.RS ;INPUT SPECTRUM* TO BE IN JSR PC.EXTRACT MOV #ARGU3,STRGAD ;CONVERT IT TO BINARY MOV #LIST5,R5 JSR PC.BINARY MOV NUMBER,R3 ;R3 = SPECTRUM # DEC R3 MUL SIZEBK.R3 :R3 - START BLOCK* OF THE REQUIRED SPECTRUM INC R3 ;ONE MORE BLOCK DUE TO THE 1ST INFO BLOCK MOV R3.DSTART ;STORE TO START BLOCK* ADJSZ: MOV SIZEBK.R3 ;STORE (# BLOCKS*(2"8))TO SIZWD_N ASH #8.,R3 ; AND TO D_SIZE MOV R3.DSIZE MOV R3.NEWSIZ ;STORE THIS AS THE NEWSIZE AS WELL CLRB ERROR ;CLEAR THE ERROR FLAG MOV #LIST7,RS ;CALL SQUEEZE TO MAKE A HOLE IN STACK 1 FOR ; THE INCOMING SPECTRUM JSR PC.SOUEEZ TSTB ERROR ;IF ERROR FLAG SET BNE FINISH ; THEN STOP : ELSE CONTINUE ;UPDATE THE SPECTRUM STATUS TABLE: UPDATE: MOV SPTADN.R5 ;UPDATE SPECT STATUS TABLE OF SPECT_N MOV 20(R5).<R5)* ;SPECTN = HEADN MOV #4095..(R5) SUB STARTP.(R5)+ •( R4IMPOSITION OF STARTPOINT ON OSCILLISCOP MOV NPOINT.(R5)t MOV STEP.(R5)+ MOV DSIZE.(R5)+ ;SIZE IN WORDS MOV (R5)+.R4 :R4 POINTS TO INFORMATION TABLE MOV *"1 ,(R4)+ THERE IS ONLY 1 SPECTRUM SO NSPECT = 1 MOV BLANK,(R4) MOV #100..(R5)+ SCALE_FACTOR*100 • 100 CLR (R5) + CLEAR THE SEPARATION MOV (R5)+.DADDR DATA TO BE PUT AT HEAD_N MOV STARTP.(R5) STARTN=STARTP DATAIN: MOV #LIST3.R5 INPUT DATA CLRB DSTATU JSR PC.DISK ;SET THE DISPLAY MODE TO DISPLAY THE NEW SPECTRUM: MOVB ARGU1,R5 SET MODE TO DISPLAY THIS SPECTRUM BIC #177760,R5 DEC R5 MOV #1 ,R4 ASH R5 . R4 BIS R4,MODE MOV SAVE,R5 UPDATE THE MODE'IN DISPLA MOV MODE.12(R5) ; JOB FINISHED FINISH: .PRINT *MSG8 PRINT 'COMMAND 'BACK' COMPLETED.' RTS PC ; DATA FIELD: SAVE : .BLKW 1 MODE : . BLKW 1 SPTAD1 BLKW 1 SPTAD2 .BLKW 1 SPTAD3 BLKW 1 SPTAD4 .BLKW 1 MSG 1 : ASCII /SPECT#'S OF CURRENTLY DISPLAYED SPECTRA ARE: / .BYTE 200 ONE : .ASCI I / 1 /<200>/ 2 /<200>/ 3 /<200>/ 4 /<200><12><15><200> . EVEN LIST 1 : WORD 3 . WORD MSG2 . WORD ARGU 1 . WORD ARGU 2 MSG2 : .ASCI I <12><15><12>/CALL THE INCOMING DATA AS SPECTRUM_N./<12><15> .ASCI I /INPUT N AND THE NAME OF THE DATA FILE: /<200> .EVEN ARGU 1 : . BLKW 1 ;SPECTRUM # OF THE INCOMING SPECTRUM ARGU2: . BLKW 10 :FILENAME IN ASCII ro ASCII / SIZE(# BLOCK): /<12x15> .ASCI I / RATE(MSEC): /<12><15> LIST2: . WORD 2 ASCII / * SCANS: /<12><15> FNAMAD .BLKW 1 ASCII / START POINT*: /<12x15> WORD FRAD50 ASCII / * POINTS: /<12><15> ASCIZ / STEP_SIZE: / FRAD50 BLKW 4 FILE_NAME IN RAD50 HAS 8 BYTES MSG4 : .ASCI I <12>/DESCRIPTION: /<200> LISTS: .WORD 5 MSG5 : ASCII <12X15>/WANT TO SEE IT7 / WORD FRAD50 .BYTE 200 DSTART BLKW 1 STARTING BLOCK* DADDR: BLKW 1 ADDRESS OF THE BUFFER FIELD IN MEM MSG6 : .ASCI I /TRY ANOTHER ONE? / DSIZE: BLKW 1 # OF WORDS TO BE TRANSFERRED BYTE 200 DSTATU BLKB 1 0=RD ; 1=WR; <0 ERROR <12>/WHICH SPECTRUM TO BE IN? INPUT ITS NUMBER: /<200> . EVEN MSG7 : .ASCI I LIST4: WORD 2 CALL QUERY MSG8 : ASCIZ /COMMAND 'BACK' COMPLETED. GO BACK TO 'DISPLAY'./ QUESAD .BLKW 1 . EVEN ANSWER BLKB 1 . EVEN :END OF SUBROUTINE BACK LIST5: WORD 2 CALL BINARY . END STRGAD BLKW 1 ....... ........ NUMBER .BLKW 1 LIST6: WORD 2 CALL EXTRAC WORD MSG7 TO INPUT THE SPECTRUM * IN FILE OF THE . WORD ARGUS SPECTRUM TO BE IN ARGUS: .BLKW 3 SPECTRUM * IN FILE LIST7: WORD 6 NEWNUM .BLKW 1 THE SPECTRUM # OF THE INCOMING SPECTRUM MODAD: WORD MODE ADDRESS OF MODE NEWSIZ .BLKW 1 SIZE OF THE NEW SPECTRUM TABLSP WORD SPTAD1 TABLE OF ADDRESSES OF SPECTRUM STATUS TABLES STKAD1 BLKW 1 ADDRESS OF STACK 1 ERROR: BLKB 1 ERROR FLAG. SET IF ERROR OCCURRED . EVEN SPTADN BLKW 1 STATUS TABLE OF THE INCOMING SPECTRU NSPECT BLKW 1 * OF SPECTRUM IN FILE SIZEBK BLKW 1 SIZE OF SPECTRUM IN BLOCKS STARTP BLKW 1 START POINT # OF THE SPECTRUM NPOINT .BLKW 1 * OF POINTS IN SPECTRUM STEP : .BLKW 1 STEP SIZE STRING BLKW 3 A BUFFER FOR A DIGITAL STRING BLANK: .ASCI I / / MSG3 : ASCII / * SPECT IN FILE: /<12><15> SUBROUTINE BINARY VERSION 1.1 1-MAR-81 •FUNCTION OF THIS SUBROUTINE IS TO CONVERT AN ASCII DIGIT STRING TO ITS BINARY EQUIVALENT. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: LIST: ASCIAD: BINUM: . WORD 2 WORD DIGIT .BLKW 1 ; ADDRESS OF DIGIT STRING, SIGN BYTE AT DIGIT*! ;RETURNED BINARY NUMBER T OF DIGIT: MAX 4 BYTES IN THE DIGIT PART, SIGN BYTE IS AHEAD OF DIGIT. ENDS WITH <200> ) .TITLE CONVERT_ASCIITOBINARY . GLOBL BINARY BINARY: MOV R4,-(SP) ;SAVE R4.R3.R2.R1 MOV R3.-(SP) MOV R2.-(SP) MOV R1.-(SP) MOV R5,SAVE ;SAVE LINK ;GET THE ASCII DIGIT STRING AND COUNT NUMBER OF DIGITAL BYTES: MOV 2(R5),R5 ;R5=ADDRESS OF THE ASCII DIGIT STRING CLR R4 ;COUNT # OF BYTES IN THE STRING 1»: CMPB #200.(R5)+ ; #200 INDATES THE END BEQ 2$ INC R4 ;R4=# OF DIGITAL BYTES IN STRING BR 1$ :CONVERT TO BINARY: CLR MOV DEC MOVB BIC ADD DEC BEQ R2 #1 ,R1 R5 -(R5),R3 MASK,R3 R3.R2 R4 SIGN (SKIP THE BYTE '200') START FROM THE LEAST SIGNIFICANT BYTE R3=BINARY FORM OF THIS BYTE R2=SUM R4=# OF BYTES MOVB BIC MUL MUL ADD SOB -( R5).R3 MASK.R3 #10. ,R 1 R1 ,R3 R3.R2 R4 . 3$ GET THE BYTE CONVERT TO BINARY GET IT SIGNIFICANCE IN DECIMAL SYSTEM MULTIPLY THESE SUM THE VALUE UNTIL ALL BYTES DONE ;CHECK THE SIGN: SIGN: CMPB I BNE NEG #'-.-(R5) FINISH R2 ; BYTE BEFORE THE DIGITAL STRING IS ITS SIGN JOB FINISHED MOV SAVE.RS :STORE THE RESULT MOV R2.4IR5) MOV (SP)».R1 :RESTORE R1.R2.R3.R4 MDV (SPI+.R2 MOV (SPI+.R3 MOV (SPI+.R4 RTS PC -.RETURN ;DATA FIELD: SAVE: BLKW 1 MASK: WORD 177760 :USED TO CONVERT ASCII DIGIT TO BINARY ;END OF SUBROUTINE BINARY . END SUBROUTINE CHANGE VERSION 1.2 30-MAR-81 U l S T : WORD 10. CALL A DATA MANIPULATING SUBROUTINE ;SAVE: . BLKW 1 ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) ;XCUR: WORD 4095 . X COORDINATE OF THE CURSOR ;YCUR: .WORD 0 Y COORDINATE OF THE CURSOR ;FACTOR WORD 0 SCALE FACTOR USED FOR DISPLAY ;MODE: BLKW 1 THE DISPLAY MODE ;SPTAD1 BLKW t ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 :SPTAD2 .BLKW ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 :SPTA03 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ;SPTAD4 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ;STKAD1 .BLKW 1 ADDRESS OF STACK I USED TO STORE THE SPECTRA FUNCTION OF THIS SUBROUTINE IS TO CHANGE THE CONTENT OF SOME SPECIFIED POINTS THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: .TITLE CHANGE . GLOBL EXTRAC,BINARY,I ECHO.QUERY.CHANGE MCALL PRINT CHANGE: ADD MOV ADD MOV MOV INPUT: MOV JSR CMPB BNE JMP 1$ : CMPB BNE JMP 2$: CMPB BNE MOV BR CONVER: MOV CMPB BNE INC 1$ : MOV JSR #4.R5 R5.XCURAD # 10. R5 R5.TABLSP 10( R5).STKAD1 ;XCURAO » ADDRESS OF X COORDINATE OF CURSOR ; TABLSP POINTS TO A TABLE CONTAINING ; ADDRESSES OF SPECTRUM STATUS TABLE ; STKAD1 POINTS TO STACK 1 #LIST1,R5 PC.EXTRAC ARGU2.#200 1$ FINISH *'N,ARGU2 2* NEGAT ARGU2+ 1 .#200 CONVER #1,BINUM STATUS ; INPUT SPECTRUM # AND COMMAND ; IF NO COMMAND ; THEN STOP :IF COMMAND IS 'N' : THEN GO TO NEGAT DIRECTLY ;IF THERE IS DIGITAL INPUT IN THE COMMAND PART THEN GOTO CONVERT IT TO BINARY ; ELSE JUST SET THAT TO ONE ; AND SKIP THE CONVERSION #ARGU2*1.STRGAD #'-,ARGU2+1 1$ STRGAD #LIST2.R5 PC.BINARY ;CONVERT DIGITAL INPUT TO BINARY ;IF NEGATIVE THEN ADVANCE THE POINTER TO THE 1 SI DIGIT ; GET THE STATUS TABLE: STATUS: MOVB ARGU1.R4 :R4=N I ASCI I ) CMPB #200.R4 ;IF NO INPUT SPECTRUM* BNE 1$ MOVB LASTN.R4 ; THEN ASSUME THE LAST INPUT SPECTRUM # 1$ : MOVB R4.LASTN ;STORE THE CURRENT SPECT* FOR LATER DEFAULT BIC #177760.R4 ;R4"N (BINARY) DEC R4 ASL R4 ;R4=0FFSET OF SPTAD_N TO SPTAO_l ADD TABLSP.R4 ;R4=#SPTAD N MOV (R4 ) .R4 :R4 NOW POINTS TO THE SPECT STATUS TABLE ;GET ADDRESS OF THE POINT AT THE CURSOR POSITION: ADDRS: MOV 2(R4).R3 SUB PXCURAD.R3 BGE 1$ :IF POSITIVE. THEN CONTINUE .PRINT #MSG5 ; ELSE PRINT ERROR MESSAGE CLR R3 MOV 2(R4),»XCURAD SET CURSOR TO START POINT 1$ : CLR R2 DIV 6(R4).R2 ;R2 = DIFFERENCE IN REL. POSITION / STEP_SIZE ASL R2 :R2 = DIFFERENCE IN MEM. SPACE (BYTES) ADD 20(R4),R2 :R2 = ACTUAL ADDRESS OF THE POINT ;INTERPRET THE COMMAND PART OF THE INPUT: 2$: CMPB #'S.ARGU2 :IF S' BNE 3$ JMP SHOW ; THEN GO TO SHOW VALUES OF POINTS 3$ : CMPB #'A.ARGU2 ;IF 'A' BNE 4$ JMP ADVANC : THEN GO TO ADVANCE THE CURSOR 4$: CMPB #'D.ARGU2 ;IF 'D' BNE 5$ JMP DEPOSI THEN GO TO DEPOSIT VALUE TO CURRENT POINT 5$: .PRINT #MSG1.1 ;PRINT THE OPTIONS BR INPUT :ASK FOR INPUT COMMAND AGAIN ;CHANGE ALL NEGATIVE TO THE AVERAGE OF THE LAST AND NEXT POSITIVE VALUES : NEGAT: MOV STKAD1.R5 ;START FROM THE HEAD OF STACK 1 MOV #4096..R4 ;AND CHECK ALL POINTS IN STACK 1 CLR R3 TST (R5) + BGE ABLPND CLR -(R5) ;IF FIRST POINT IS NEGATIVE CLEAR IT ABLOOP: TST (R5) + BGE ABLPND MOV -4(R5) .R2 ;NEGATIVE: R2 =LAST POSITIVE # 3$ : INC R3 • R3=# OF POSITIVE POINTS DEC R4 BEO ENDNEG ;IF THE END IS NEGATIVE THEN GO TO ENDNEG TST (R5 ) + ;ELSE IF MORE NEGATIVES BLT 3$ : THEN GO TO 3$ TO COUNT # OF NEGATIVES ADD -(R5I.R2 ;ELSE COMPUTE THE AVERAGE OF THE TWO ASR R2 ; POSITIVE #S SUB R3 . R5 ;MOVE THE POINTER BACK TO THE 1ST SUB R3.R5 ; NEGATIVE* 4$: MOV R2. <R5) + .CHANGE THE NEGATIVES TO THE AVERAGE SOB R3.4S ADD #2.R5 :MOVE THE POINTER TO THE NEXT POINT ABLPND: SOB R4.ABL00P JMP FINISH ENDNEG: MOV R2.-(R5) ;IF THE END IS ALSO NEGATIVE CHANGE THESE SOB R3,ENDNEG NEGATIVES TO THE LAST POSITIVE VALUE JMP FINISH ;SHOW VALUES: SHOW: MOV BINUM.R3 :R3 = POINT COUNTER BGE 1* NEG R3 1*: .PRINT #MSG2 •.ECHO THE SPECTRUM * PRINT #MSG2.t ;PRINT HEADING MOV #4095.,R1 SUB PXCURAD,R1 ;R1 = CURRENT POINT* CLR RO DIV 6(R4),RO ;ROUND OFF THE CURRENT POINT* TO MOV R0.R1 ; MULTIPLE OF STEP SIZE CLR RO MUL 6(R4),R1 SHLOOP: MOV R1 . 14 MOV #LIST3.R5 ;ECHO THE POINT* JSR PC.I ECHO .PRINT #MSG2.2 ;PRINT SPACING MOV (R2).14 ;ECHO THE OLD VALUE MOV #LIST3.R5 JSR PC,I ECHO ;OUTPUT OLD VALUE PRINT #MSG2.3 ;PRINT LINEFEED AND RETURN TST BINUM ;IF BINUM IS NEGATIVE BGT 1$ SUB 6(R4),R1 : THEN ECHO THE LEFT POINTS SUB #2.R2 BR 2$ 1$ : ADD G(R4).R1 ; ELSE ECHO THE RIGHT POINTS ADD #2.R2 2$: SOB R3.SHLOOP JMP INPUT ;G0 TO INPUT OTHER COMMANDS ;DEPOSIT NEW VALUE: DEPOSI MOV BINUM.(R2) :DEPOSIT THE NEW VALUE MOV #1.BINUM BR SHOW ;G0 TO SHOW THE NEW VALUE ;ADVANCE N POINTS: ADVANC MOV BINUM.R1 ADD Rl .R2 ;ADVANCE THE POINTER TO MEMORY ADD R 1 , R2 ;1 POINT = 2 BYTES MUL 6 ( R4).R 1 SUB R1.axCURAD ;ADVANCE THE CURSOR (TO RIGHT) MOV #1.BINUM BR SHOW ;G0 TO SHOW THE CURRENT POINT ;JOB DONE FINISH: .PRINT *MSG4 RT S PC ;PR1NT 'COMMAND 'CHANGE' FINISHED. : RETURN DATA FIELD: TABLSP: BLKW 1 XCURAD: BLKW STKAD1: .BLKW 1 ; ADDRESS OF THE TABLE CONTAINING ADDRESSES OF : THE SPECTRUM STATUS TABLES : ADDRESS OF X COORDINATE OF CURSOR ; ADDRESS OF STACK 1 WHERE SPECTRA ARE STORED LIST1: WORD 3 .WORD MSG 1 ARGAD1: .WORD ARGU 1 ARGAD2: .WORD ARGU2 ; CALL EXTRAC TO GET INPUT : MESSAGE ADDRESS : ADDRESS OF ARGUMENT TO BE INPUT ARGU1: ARGU2: . ASCI I <12><15> ASCII /INPUT SPECTRUM # AND THE REOUIRED OPERATION (.? IF CONFUSED)/ .ASCII / : /<200> . EVEN .BLKW 1 BLKW 5 ;SPECTRUM # ;REOUIRED OPERATION LIST2: WORD 2 :CALL BINARY TO CONVERT ASCII STRING TO BINARY STRGAD: BLKW 1 ;AODRESS OF THE ASCII STRING BINUM: .BLKW 1 LISTS: . WORD 1 ;CALL IECHO TO ECHO A 14 NUMBER 14 : BLKW 1 . ASCI I . ASCI I . ASCI I ASCII . ASCI I ASCII . ASCI I .ASCII .ASCII ASCII . ASCI I . ASCI I <12>/THE FOLLOWINGS ARE SOME EXAMPLES OF A VALID OPERATION:/ <12xl5>/ 1. 'A 10' MEANS 'ADVANCE 10 POINTS' ./ <12x15>/ 2. ' A -10' MEANS 'GO BACK 10 POINTS' ./ <12><15>/ 3. 'D 10' MEANS 'DEPOSIT 10 AS THE VALUE OF THE / /CURRENT POINT' ./<12><15> <12><15>/ 4. 'N' MEANS / OF THE TWO POSITIVE/ < I2>< 15>/ •:12X1S>/ 5. 'S 10' <12><15>/ G. 'S -10 <I2><I5>/ 7. ' < I2>< 15x 12x200> 'CHANGE ALL NEGATIVES TO AVERAGE/ BOUNDS' ./ MEANS 'SHOW THE FOLLOWING 10 POINTS' ./ MEANS 'SHOW THE PRECEDING 10 POINTS' ./ MEANS 'NO OPERATION. JUST RETURN' ./ MSG2 : LASTN: MSG2 . 1 : MSG2 . 2 : . ASCI I ASCI I . ASCI I . ASCI I <12>/THE SPECTRUM * IS / /2/<200> :SET THE INITIAL DEFAULT TO 2 <12><15>/ POINT * / /<200> POINT VALUE /<12><15>/ /<20C> MSG2.3: ASCII <12><15>/ /<200> MSG4: .ASCIZ /COMMAND 'CHANGE' FINISHED. BACK TO 'DISPLAY'./ : MSG5: ASCIZ /»»• THE CURSOR IS OUT OF RANGE. NOW SET TO THE START POINT./ EVEN : ; END OF SUBROUTINE CHANGE ; . END ro CO SUBROUTINE CHARAC VERSION 1.1 1-MAR-8 1 * * * * * * * » * * * * * * * * * * * * * * * * * * * * * * * » * » * * * * * * * * * * * * * * * * * * » * * * * * * * * * * * * * * * * * * * * * * * * FUNCTION OF THIS SUBROUTINE IS TO CONVERT BINARY TO ASCII FOR PRINT OUT. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS : LIST: WORD 2 BINUM: .BLKW 1 jTHE BINARY NUMBER ASCIAD: .WORD DIGIT .ADDRESS OF THE DIGITAL PART OF THE STRING (BINARY NUMBER RANGED FROM -9999 TO 9999 WILL BE OK. ) (UPON RETURN. DIGIT CONTAINS MAX 4 DIGITAL BYTES AND ENDS WITH <200>) (DIGIT+1 CONTAIN THE SIGN BYTE IF IT IS NEGATIVE ) .TITLE CONVERT_BINARY_TO ASCII . GLOBL CHARAC CHARAC: MOV R3. -(SP) ;SAVE R3.R2,R1.RO MOV R2. -(SP) MOV R1 . "(SP) MOV RO. -(SP) : TEST SIGN: MOV 2(R5) . R3 MOV 4(R5) ,R5 SIGN: TST R3 BGE BEGIN NEG R3 MOVB # ' - . -KR5) ; R4=BINARY NUMBER : R5 = ADDRESS OF DIGITAL ASCII STRING :IF NOT NEGATIVE : THEN BEGIN THE CONVERSION : ELSE CHANGE IT TO POSITIVE ; AND PUT A '-' IN FRONT OF THE DIGITS BEGIN CONVERSION BEGIN: IGETI4 : CLRB LEADO ;BEGIN CONVERSION. LEADO SET IF NO LEADING 0 MOV #10000..R1 CLR RO DIV #10.,R0 R0=10OOO/10=10O0 AT FIRST BEO FINISH MOV RO, R 1 CLR R2 LOOP 4 TIMES TO GET 4 DIGITS OUT DIV R0.R2 R2 » MOD (14, 10**N) BNE CONVER IF NOT 0. THEN CONVERT AND STORE TSTB LEADO ELSE IF LEADING 0. THEN SKIP THIS BEO GETI4 ELSE CONTINUE BISB #60.R2 CONVERT TO ASCII MOVB R2.(R5)+ STORE INCB LEADO NO MORE LEADING ZERO BR GETI4 FINISH: TST LEADO BNE DONE IF ALL ARE LEADING ZERO THEN GIVE A ZERO ELSE NO OPERATION MOVB #'0.(R5)+ MOVB #200.(R5) MOV (SPl+.RO MOV (SPI+.R1 MOV (SPI+.R2 MOV (SP)+,R3 RT S PC APPEND 200 AT THE END OF THS STRING FOR PRINTING PURPOSE RESTORE R0.R1.R2.R3 DATA FIELD LEADO BLKB EVEN 1 ; FLAG INDICATES IF LEADING ZERO OCCURRED END OF SUBROUTINE CHARAC . END ro oo ro SUBROUTINE CLEAR VERSION 1.1 1-MAR-81 FUNCTION OF THIS SUBROUTINE IS TO CLEAR PART OF A SPECTRUM. THE PARAMETER LIST PASSEO TO THIS SUBROUTINE IS: LIST : WORD 10. SAVE : . BLKW 1 XCUR : .WORD 4095 YCUR : WORD 0 FACTOR WORD 0 MODE : BLKW 1 SPTAD1 BLKW 1 SPTAD2 BLKW 1 SPTAD3 BLKW 1 SPTAD4 .BLKW 1 STKAD1 BLKW 1 CALL A DATA MANIPULATING SUBROUTINE ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) X COORDINATE OF THE CURSOR V COORDINATE OF THE CURSOR SCALE FACTOR USED FOR DISPLAY THE DISPLAY MODE ADDRESS OF SPECTRUM STATUS TABLE OF SPECT 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 ADDRESS OF SPECTRUM STATUS TABLE OF SPECTS AOORESS OF SPECTRUM STATUS TABLE OF SPECT4 ADDRESS OF STACK 1 USED TO STORE THE SPECTRA .TITLE CLEAR_CONTENT_OF_A_SPECTRUM .GLOBL EXTRAC.QUERY.CLEAR .MCALL PRINT ADD MOV #14.R5 R5.TABLSP ; TABLSP IS THE TABLE CONTAINING THE ADDRESSES ; OF THE SPECTRUM STATUS TABLE INPUT SPECTRUM # TO BE CLEARED: INPUT MOV JSR MOVB #LIST1,R5 PC,EXTRACT #40,ARGU1+1 :INPUT SPECTRUM # ;REPLACE BYTE '200' WITHA A BLANK ASK CONFIRMATION: MOV JSR #LIST2.R5 PC.QUERY ;ASK: 'REALLY WANT TO CLEAR SPECT N?' TSTB ANSWER IF 'NO' BEQ FINISH • THEN STOP ELSE CONTINUE GET_SPECT_STATUS_TABLE: MOVB ARGU1.R5 R5=N (ASCII) BIC #177760.R5 R5=N (BINARY) DEC R5 ASL R5 R5=0FFSET OF SPTAD N TO SPTAD1+2 ADD TABLSP.R5 R5»#SPTAD N MOV (R5),R5 R5=ADDRESS OF SPECT STATUS TABLE CLEAR THE DISPLAYING PART OF THE SPECTRUM: OPERAT: MOV MOV MOV 4(R5).R4 <R5),R3 16(R5).R5 R4=# OF POINTS TO BE CLEARED R3=P0INTER TO THE REGION TO BE CLEARED R5=SEPERATI0N FROM BASELINE 1$: MOV R5.(R3)+ ;CLEAR THE REGION SOB R4.1$ ;CONTINUE :JOB DONE: FINISH: .PRINT #MSG3 ;PRINT 'REQUEST DONE.' RTS PC ;RETURN ;OATA FIELD: TABLSP: .BLKW 1 ;TABLE OF ADDRESSES OF SPECT STATUS TABLE LI ST 1: WORD . WORD WORD 2 MSG 1 ARGU1 CALL EXTRAC TO GET SPECT* MESSAGE ADDRESS SPECT* ADDRESS LIST2: .WORD 2 .WORD MSG2 ANSWER: .BLKB 1 CALL QUERY TO ASK FOR A DECISION MESSAGE ADDRESS RETURN ANSWER: 1=YES 0=N0 MSG 1 : .ASCII /INPUT THE SPECTRUM #: /<200> MSG2 : ASCII /REALLY WANT TO CLEAR SPECTRUM / ARGU1: . BLKW 1 .FIRST BYTE IS ASCII DIGIT, SECOND .ASCI I /? /<200> MSGS : ASCIZ /COMMAND 'CLEAR' FINISHED. BACK TO 'DISPLAY ./ . EVEN END OF SUBROUTINE CLEAR END SUBROUTINE DISK VERSION 1.1 1-MAR-81 FUNCTION OF THIS SUBROUTINE IS TO READ/WRITE A FILE ON DISK. THE PARAMETER LIST OF THIS SUBROUTINE IS AS FOLLOWS: LIST: FNAMAD: DSTART: DADDR: DSIZE: DSTATU: . WORD . BLKW .BLKW BLKW BLKW BLKB . EVEN FILENAME ADDRESS STARTING BLOCK NUMBER STARTING ADDRESS OF THE DATA FIELD TO BE USED * OF BLOCKS TO BE TRANSFERED STATUS: BIT 1=1 IF WRITE TO DISK BIT 1=0 IF READ FROM DISK UPON RETURNED: NEGATIVE IF FAILED TITLE GLOBL DISK DISK MCALL .PRINT,.FETCH. LOOKUP,.READW, .WRITW, CLOSE MOV MOV MOV RI.-(SP) R2.-(SP) RS.-(SP) ;SAVE Rl. R2. AND R3 : FETCH DISK HANDLER: MOV 2(R5).R1 MOV #HANDLR,R2 :R1 POINTS TO FILE-NAME, R2 TO HANDLER .FETCH R2.R1 BCC LOOK ;IF HANDLER FETCHED. GOTO LOOKUP FILE MOV 0FETMSG.RO ;IF NOT. PRINT 'FETCH FAILED' ;ERROR HANDLING: FAIL: PRINT ;PRINT MESSAGE MOVB #-1.12(R5) ;RETURN AN ERROR MESSAGE TO CALLING ROUTINE BR CLOSE :LOOK UP THE FILE: LOOK: LOOKUP *LIST.#0.R1 BCC TRANSF MOV *LKMSG.RO BR FAIL ;READ/WRITE DATA: TRANSF: MOV 6(RS).R1 : R 1 POINTS TO THE BUFFER STACK MOV 4(R5).R2 : R2 CONTAINS THE STARTING BLOCK NUMBER MOV 10(R5).R3 :R3 CONTAINS THE * OF WORDS TO BE TRANSFERED TSTB 12IR5) ; SEE WHETHER WRITE OR READ BNE WRITE ; IF CODE =1. GOTO WRITE READ : .READW #LIST.#0,R1 R3.R2 ;READ DATA FROM CHANNEL 0 BCC CLOSE ; IF READ. GOTO CLOSE THE CHANNEL MOV •RDMSG.RO ; IF NOT. PRINT 'READ FAILED' ; LUUtvur mt rut r K u n i.nni«NCL V ;IF FILE FOUND.GOTO READ OR WRITE ;IF NOT. PRINT 'LOOKUP FAILED' ;GOTO PRINT MESSAGE BR FAIL ;GOTO PRINT MESSAGE WRITE: WRITW #LI ST,#0,R1,R3.R2 :WRITE DATA FROM CHANNEL O BCC CLOSE ;IF WRITTEN. GOTO CLOSE THE CHANNEL MOV #WTMSG,RO :IF NOT. PRINT 'WRITE FAILED' BR FAIL ; DATA TRANSFER DONE. CLOSE THE DATA CHANNEL: CLOSE CLOSE #0 ;CLOSE CHANNEL 0 MOV (SP)+,R3 MOV (SPI+.R2 ;RESTORE R1,R2,AND MOV (SPI+.R1 RTS PC :RETURN DATA FIELD: LIST : .BLKW 5 ;WORKING SPACE FOR THE DISK OPERATION FETMSG: ASCIZ /CAN NOT FIND THE DEVICE, CHECK DEVICE NAME./ LKMSG: .ASCIZ /FILE DOES NOT EXIST. CHECK FILE NAME./ RDMSG: ASCIZ /READ FAILED. MAY BE EXCEEDED END OF FILE./ WTMSG: .ASCIZ /WRITE FAILED, MAY BE FILE IS NOT LARGE ENOUGH./ . EVEN HANDLR: BLKW 2000 ;SPACE FOR DEVICE HANDLER ;END OF SUBROUTINE DISK . END ro oo SUBROUTINE DISPLA VERSION 1.1 THE FUNCTION OF THIS SUBROUTINE IS TO DISPLAY SOME SPECTRA OUT TO AN OSCILLISCOPE. THE PARAMETER LIST PASSED TO THIS SUBROUTINE HAS THE FOLLOWING FORM : LIST : MODAD: .WORD WORD 7 MODE STKAD1 .WORD STACK 1 SPTAD1 WORD SPECT1 SPTAD2 .WORD SPECT2 SPTAD3 .WORD SPECT3 SPTAD4 .WORD SPECT4 FLAGAD .BLKW 1 CALL DISPLA ADDRESS OF BIT BIT BIT BIT BIT THE DISPLAY MODE 1 = 1 SPECT 1 IS TO BE DISPLAYED 2 • 1 SPECT2 IS TO BE DISPLAYED 3 = 1 SPECT3 IS TO BE DISPLAYED 4 = 1 SPECT4 IS TO BE DISPLAYED 9 = 0 A NEW SCAN 1 RESTART A TERMINATED JOB TO GET MORE SCAN (SEE SUBROUTINE SCAN) SCAN IS OFF SCAN IS ON (SPECT2 IS THE RESULT ) ADDRESS OF ADDRESS OF ADDRESS OF ADDRESS OF ADDRESS OF ADDRESS OF 8 = 0 1 STACK 1 THE STATUS TABLE OF SPECTRUM 1 THE STATUS TABLE OF SPECTRUM 2 THE STATUS TABLE OF SPECTRUM 3 THE STATUS TABLE OF SPECTRUM 4 A FLAG TO COMMUNICATE WITH 'SCA TITLE . GLOBL . MCALL DISPLAYDATA DISPLA.KYINHD .PRINT DATA INITIALIZATION: CTCR = CTBR = CKCR = CKBR = |RAMP = XOUT = YOUT = IKEYCR IKEYBR TTCR = 1G7762 167774 1704 20 170422 170440 1704 4 4 170442 = 177560 = 177562 177564 COUNTER CONTROL REGISTER COUNTER BUFFER REGISTER REAL TIME CLOCK CONTROL REGISTER REAL TIME CLOCK BUFFER REGISTER RAMP OUTPUT BUFFER REGISTER X AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE Y AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE KEYBOARD INPUT CONTROL REGISTER KEYBOARD INPUT BUFFER REGISTER TERMINAL OUTPUT CONTROL REGISTER DISPLA: ADD #2.R5 MOV R5.SAVE MOV ©(R5I+.M0DE MOV (R5)*.STKAD1 MOV (R5)+.SPTAD1 MOV (R5)+.SPTAD2 MOV (R51+.SPTAD3 MOV (R5 )+,SPTAD4 MOV ( R5).FLAGAD CLRB 9FLAGAD MOVB #1.MODTST THE DISPLAY MODE ADDRESS OF STACK 1 THE POINTERS TO SPECTRUM STATUS TABLES ADDRESS OF A FLAG USED TO COMMUNICATE BETWEEN 'SCAN' AND 'DISPLA' ' MAKE SURE THAT THE FLAG IS CLEAR MODTST IS A MASK WITH ONE BIT SEI CLR OFFSET ;OFFSET = OFFSET FROM SPTAD1 TO SPTAD_N ;MOVE UP THE SPECTRA FROM THE BASE LINE IN ORDER TO SHOW THEM TOGETHER: i$: BITB MODTST,MODE ;MOVE UP ALL SPECTRA TO BE DISPLAYED BY SEPERN BEO 2$ MOV OFFSET,RO ADD #SPTAD1.RO R0=# SPTAD N MOV (RO ) .RO RO = SPTAD N MOV (R0).R1 R1 =ADDR OF 1ST POINT MOV 4(RO),R2 R2=#0F POINTS MOV 16(RO),RO RO'SEPER N. 3$: ADD RO.(R1)+ SOB R2 . 3$ 2$ : ASLB MODTST ;OPERATE THE NEXT SPECTRUM ADD #2.OFFSET POINTS TO NEXT SPECTRUM STATUS TABLE BITB #20,MODTST BEO 1$ MOV »#60.KEYHND SAVE THE SYSTEM KEYBOARD HANDLER MOV #KEYINT,e#60 SET THE DISPLAY KEYBOARD HANDLER CLR e#62 TSTB MODE IF SCAN IS ON BLT OSCILL THEN DON'T ENABLE KEYBOARD INTERRUPT MOV # 100.9#KEYCR BECAUSE IT IS TURNED ON BY 'SCAN' ; SHOW THE SPECTRA ON OSCILLISCOPE: OSCILL : MOV #1 ,MODTST A ONE-BIT MASK TO TEST IF DISPLAY SPECT N CLR OFFSET OFFSET = OFFSET FROM SPTAD1 TO SPTADN TSTB ©FLAGAD IF FLAG AT FLAGAD IS NOT SET TO NEGATIVE BGE LOOP 1 THEN CONTINUE DISPLAYING JMP OUT ELSE JUMP OUT OF THE DISPLAY LOOP (SCAN SET FLAG TO NEGATIVE AT THE END L00P1: BITB MODTST.MODE IF NOT DISPLAY SPECT N BEO NEXTSP THEN GOTO SEE IF DISPLAY SPECT_N+1 ELSE DISPLAY SPECT_N MOV OFFSET,RO ADD #SPTAD1.RO RO = #SPTAD N MOV (RO).RO RO = SPTAD N MOV (R01+.R1 R1=CHANNEL ADDRESS MOV (ROl+.XOUT MOV (RO)+,R2 R2=NP0INT MOV (ROI+.RO R0=STEP SIZE TSTB MODE BITS OF MODE SET IF SCANNING BGT TOOSC IF SCANNING AND DISPLAYING THEN THE SUM MAY CHANGE BY FACTOR BITB #2.MODTST BNE ADJLP GO TO ADJUST AND OISPLAY TOOSC: MOV (R 1 )+.YOUT ELSE JUST DISPLAY SUB RO.XOUT SOB R2.TOOSC ; SHOW NEXT SPECTRUM: NEXTSP : ASLB MODTST TEST SPECT N-M ro Co cn ADD #2.OFFSET BNE 1$ THEN GO TO TEST OTHER BITB #20.MODTST IF N+1=5 INC FACTOR ELSE INCREMENT FACTOR BY ONE AND RETURN BNE ENDSP THEN DISPLAY CURSOR OR SPOT JMP RETURN BR LOOP1 ELSE LOOP1 TO DISPLAY 1$: CMPB »'-.RO IF NOT rIF THIS IS THE SUM OF PREVIOUS SCAN IN A SCANNING MODE. THEN ADJUST IT SCALE: BNE 2$ THEN GO TO TEST OTHER ADJLP: MOV (R1)+.R5 ADJUST THE VERTICAL SCALE DEC FACTOR ELSE DECREASE FACTOR BY ONE AND RETRUN ASH FACTOR.R5 JMP RETURN MOV R5 YOUT SUB RO.XOUT :CURSOR CONTROL SOB R2.ADJLP 2$: CMPB #'U.RO IF NOT 'U' ASLB MODTST BNE 3$ THEN GO TO TEST OTHER ADD #2.OFFSET ADD DELTA.YCUR ELSE INCREASE THE Y COORDINATE OF CURSOR BR LOOP1 JMP RETURN ;END OF ONE COMPLETE SHOW OF ALL REQUIRED SPECTRA : 3$: CMPB #'D.RO IF NOT ' D' BNE 4$ THEN GO TO TEST OTHER ENDSP: TSTB MODE IF SCAN IS ON DISPLAY CURRENT SCANNING SPOT SUB DELTA.YCUR ELSE DECREMENT THE Y CORRDINATE OF CURSOR BGE CURSOR OTHERWISE SHOW A CURSOR JMP RETURN :IF SCANNING. SHOW CURRENT SCANNING POINT: 4$: CMPB »'R.RO IF NOT •R' BNE 5$ THEN GO TO TEST OTHER SPOT : CLR YOUT RESET Y TO BASELINE SUB DELTA.XCUR ELSE MOVE CURSOR TO RIGHT-MOV RAMP,XOUT SHOW THE CURRENT SPOT JMP RETURN MOV -2(R3).YOUT R3 IS POINTING TO THE NEXT POINT BR DELAY 5$: CMPB #'L.RO IF NOT 'L' BNE 6$ THEN GO TO TEST OTHER ;IF NOT SCANNING. SHOW CURSOR: ADD DELTA.XCUR ELSE MOVE CURSOR TO LEFT JMP RETURN CURSOR: CLR YOUT RESET Y TO BASELINE MOV XCUR,XOUT SHOW THE CURSOR 6$: CMPB #'F.RO IF NOT ' F ' MOV YCUR.YOUT BNE 7$ THEN GO TO TEST OTHER CMP #2000.DELTA ELSE INCREASE DELTA EXCEPT IT = 2000 DELAY: MOV SPTAD1,R5 R5 POINTS TO THE STATUS TABLE OF SPECT1 BLE RETURN MOV 4(R5).R1 R1 = # OF POINTS DISPLAYING FOR SPECT2 ASL DELTA ASH #-5.R1 R1=R1/32 BR RETURN 1$ : SOB R1 . 1$ 7$: CMPB #'S.RO IF NOT 'S' :GO BACK TO SHOW ALL REQUIRED SPECTRA AGAIN: BNE 28$ THEN GO TO TEST OTHER CMPB #1 .DELTA ELSE DECREASE DELTA EXCEPT IT = 1 BR OSCILL BEQ RETURN ASR DELTA BR RETURN :OUT OF THE DISPLAY LOOP: 28$ : CMPB #-^ .RO IF NOT OUT : MOV KEYHND.»#60 MOVE BACK SYSTEM KEYBOARD HANDLER BNE 8$ THEN GO TO TEST OTHER CLR P#G2 MOV #4095..XCUR ELSE RESET CURSOR RTS PC RETURN TO THE CALLING ROUTINE CLR YCUR MOV #128..DELTA AND SET DELTA TO A REASONABLE VALUE .PRELIMINARY KEYBOARD INTERRUPT HANDLER: BR RETURN <EYINT: MOV RO.-(SP) :SAVE RO.R5 :SET THE CURRENT SCAN TO BE THE LAST SCAN: MOV R5.-(SP) 8$ : CMPB #52.RO IF NOT ' * ' MOV YOUT,YBUFFR ;SAVE YOUT BNE 9$ THEN GO TO TEST OTHER MOV #7777.YOUT ;MOVE OUT THE LIGHT BEAM TEMPORARILY MOVB #1,»FLAGAO ELSE SET A FLAG TO INDICATE THAT THIS CLR P#KEYCR ;DISABLE INTERRUPT IS THE LAST SCAN AND SHOULD STOP MOV P#KEYBR.RO ;RO - THE INPUT BYTE BR RETURN CMPB #'+.RO ;IF NOT : DATA MANIPULATING MODE: 9$: CMPB #33,RO IF NOT ESC ' RETURN CLR ERRCNT ;CLEAR COUNT IF SUCCESS BNE 10$ THEN GO TO CHECK IF WANT TO CHANGE MODE FINISH MOV (SP)+,R5 ;RESTORE R5.R0 MOV #77777,R5 SET A DELAY TO LET ALL OUTPUT BUFFER BE MOV #77777,RO 40$ : SOB R5.40$ EMPTY 1$: SOB RO. 1$ ;SET A DELAY TO EMPTY SYSTEM BUFFER MOV KEYHND.9#60 CHANGE BACK THE SYSTEM KEYBOARD INTERRUPT MOV (SPI+.RO :RESTORE RO MOV #100.e*KEYCR HANDLER MOV YBUFFR,YOUT ;RESTORE THE ORGINAL POINT MOV #LIST1,R5 THEN CALL THE USER KEYBOARD INTERRUPT MOV # 100.«>#KEYCR ;ACT IVATE THE KEYBOARD INTERRUPT HANDLE JSR PC,KYINHD HANDLER TO DO DATA MANIPULATION RT I ;RETURN TO INTERRUPTED POINT MOV #KEYINT.P#60 UPON RETURN. SET THE PR1MINARY HANDLER JMP RETURN ;CHANGE MODE : DATA FIELD: 10$: CMPB #'1,R0 IF NOT 1 ' -IST1: WORD 10. ;CALL KYINHD BNE 1 1$ THEN GO TO CHECK OTHERS ; (THIS LIST IS SAME AS THAT USED TO CALL ALL BIS #1.MODE ELSE SET THE FIRST BIT TO DISPLAY SPECT1 ; DATA MANIPULATING SUBROUTINE) BR RETURN SAVE : BLKW 1 ;ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' : (JUST USED FOR FURTHER MODIFICATION) 1 1$: CMPB #'!,R0 IF NOT i ' BNE 12$ THEN GO TO CHECK OTHERS XCUR : .WORD 4095 . ;X COORDINATE OF THE CURSOR BIC #1.MODE ELSE CLEAR FIRST BIT TO DELETE SPECT1 YCUR : WORD 0 ;Y COORDINATE OF THE CURSOR BR RETURN FACTOR . WORD 0 ;SCALE FACTOR USED FOR DISPLAY SUM OF SCANS 12$: CMPB #'2,RO IF NOT 2' BNE 13$ THEN GO TO CHECK OTHERS MODE : BLKW 1 :THE DISPLAY MODE BIS #2.MODE ELSE SET SECOND BIT TO DISPLAY SPECT2 SPTAD1 BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 BR RETURN SPTAD2 BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 SPTAD3 .BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 13$: CMPB #'P.RO IF NOT »' SPTAD4 . BLKW 1 ;ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 BNE 14$ THEN GO TO CHECK OTHERS STKAD1 .BLKW 1 ;ADDRESS OF STACK 1 USED TO STORE THE SPECTRA BIC #2.MODE ELSE CLEAR SECOND BIT TO DELETE SPECT2 BR RETURN OFFSET .BLKW 1 ;OFFSET FROM SPTAD_N TO SPTAD_1 14$: CMPB #'3.RO IF NOT 3 ' BNE 15$ THEN GO TO CHECK OTHERS ERRCNT . WORD 0 :ERROR COUNT OF KEYBOARD PRESS BIS #4,MODE ELSE SET THIRD BIT TO DISPLAY SPECT3 BR RETURN DELTA: .WORD 128 . ;THE SPEED CONTROLLER OF CURSOR MOVEMENT 15$: CMPB #'#,RO IF NOT ' # ' KEYHND .BLKW 1 ;THE ORGINAL SYSTEM KEYBOARD HANDLER BNE 16$ THEN GO TO CHECK OTHERS BIC #4,MODE ELSE CLEAR THIRD BIT TO DELETE SPECT3 FLAGAD BLKW 1 ;THE FLAG ADDRESS TO INDICATE THAT SHOULD BR RETURN ; STOP AFTER THE CURRENT SCAN 16$: CMPB #'4,RO IF NOT '4' YBUFFR BLKW 1 :BUFFER FOR STORING YOUT TEMPORARY BNE 17$ THEN GO TO CHECK OTHERS BIS #10.MODE ELSE SET FOURTH BIT TO DISPLAY SPECT4 MODTST BLKB 1 ;A ONE-BIT BIT-TEST MASK BR RETURN 17$: CMPB #'$.RO IF NOT '$' MSG 1 : .ASCI I /»*/<200> AND TYPE 'HELP' IF CONFUSED./ BNE 18$ THEN GO TO CHECK ERROR COUNT MSG2 : .ASCIZ /PRESS 'ESC', BIC #10.MODE ELSE CLEAR FOURTH BIT TO DELETE SPECT 4 .EVEN BR RETURN 18$ : INC ERRCNT INC ERROR COUNT IF INVALID INPUT ;END OF SUBROUTINE DISPLA CMP #10. .ERRCNT IF IT HAPPENS 10 TIMES BEFORE SUCCESS BGE FINISH THEN PRINT ERROR MESSAGE . END .PRINT #MSG1 PR INT ( ' ONLY ' ESC ' . ' + ' AND '-' A'RE ALLOWED ') ...... ........ .............. ,,«,.,.....«.,...•...»».»•*««»•»«•••»••»•»«»•»*•»• .PRINT #MSG2 _____ ro oo \i SUBROUTINE EXTRAC VERSION 1.1 THE FUNCTIONS OF THIS SUBROUTINE ARE: 1 OUTPUT A QUERYING MESSAGE. 2 INPUT SOME ARGUMENTS THAT ARE SEPARATED BY A COMMA. THE SUBROUTINE EXTRACTS THE ARGUMENTS OUT AND PUTS THEM TO THE ARGUMENT LIST. AFTER DELETING THE UNNECESSARY BLANKS THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: LIST : MSGAD: ARGAD1 ARGAD2 . WORD .BLKW BLKW .BLKW THERE ARE 3-1=2 ARGUMENTS TO BE INPUT ADDRESS OF THE MESSAGE ADDRESS OF ARGUMENT 1 ADDRESS OF ARGUMENT 2 .TITLE EXTRACT_SOME_ARGUMENTS_OUT_FROM_INPUT .GLOBL EXTRAC MCALL GTLIN, PRINT MOV MOV MOV MOV R5.SAVE RO.-(SP) R3.-1SP) R4.-ISP) ;SAVE THE LINK :SAVE RO.R3.R4 CALCULATE NUMBER OF ARGUMENTS AND INPUT ARGUMENTS: MOV (R51+.R3 DEC R3 MOV (R5)+,R4 GTLIN #LNBUF.R4 MOV #LNBUF,RO MOV RO.R4 TSTB (R4) + BNE 1$ CLRB (R4) MOVB COMMA,-(R4) GET NUMBER OF ARGUMENTS PLUS 1 NUMBER OF ARGUMENTS NOW IN R3 GET MESSAGE PRINT A MESSAGE AND GET ONE LINE RO POINTS TO INPUT :INSERT A COMMA TO THE END OF THE INPUT LINE : END OF LINE IS A BYTE 'O' EXTRACT ARGUMENTS OUT AND STORE: LOOP : SKIP: MOV CMPB BEQ CMPB BEQ TSTB BEQ MOVB BR (R51+.R4 #40.(R0) + SKIP COMMA.-(RO) ARGEND (RO) ABNORM (R0)+.<R4)+ SKIP ;R4 POINTS TO THE ARGUMENT :SKIP BLANKS : IF END OF ONE ARGUMENT ;IF END OF LINE BEFORE GETTING ALL P^ARAMETERS. THEN ASK AGAIN ; STORE INPUT AS ARGUMENT ; THEN GOTO TEST THE NEXT BYTE ARGEND: MOVB INC SOB #200.(R4) RO R3,LOOP ;#200 AS END OF ARGUMENT ;GET NEXT BYTE IN THE LINE BUFFER :UNTIL GOT ALL ARGUMENTS JOB DONE MOV (SPI+.R4 :RE STORE RO.R3.R4 MOV (SP)*.R3 MOV (SP)+.RO RTS PC ;RETURN :IN CASE NO ENOUGH ARGUMENTS. THEN COMPLAIN AND ASK FOR THEM AGAIN: ABNORM .PRINT #MSG1 ;N0 ENOUGH INPUT ARGUMENTS. TRY AGAIN MOV SAVE,R5 BR BEGIN ; DATA FIELD: SAVE : .BLKW 1 : THE LINK LNBUF: .BLKW 41 :INPUT LINE BUFFER COMMA: . ASCI I /./ MSG 1 : .ASCIZ NO ENOUGH ARGUMENTS. ARGUMENTS ARE SEPERATED BY A COMMA. . EVEN ro CO CO ********* SUBROUTINE FNAME * * * * * * * * * * * * VERSION 1.1 1-MAR-81 LIST: .WORD 2 ASCFN: BLKW 1 ;ADDRESS OF THE FILE RADFN: BLKW 1 ;ADDRESS OF THE FILE t****************************************************** FUNCTION OF THIS SUBROUTINE IS TO CONVERT AN ASCII STRING TO A FILE NAME WITH PROPER RAD50 FORMAT. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: IAME IN ASCII FORM IAME IN RAD50 FORM (FILE NAME IN ASCII FORM IS AN ASCII STRING. UPON RETURN RADFN (WILL CONTAIN A 8 BYTES FILE NAME. (DEFAULT: DEVICE IS DK: (PROPER ASCII FILE NAME: MAX 3 BYTES FOR DEVICE. 6 BYTES FOR ( NAME AND 3 BYTES FOR TYPE. ( E.G. DY1:FLNAME.PES (IF BYTE PRECEDING ':' IS 'O'. OR 'Y' THEN DEVICE IS SY: ( ELSE DEVICE IS DK: (IF NAME IS MORE THAN 6 BYTES. IT WILL BE TRUNCATED. (IF TYPE HAS LESS THAN 3 BYTES. BLANKS WILL BE APPENDED. * • * * * * * # • * * * * * * * • * * * * * * » + « * • * # * * * » • * » * » « * » * » * * * » • * » « * * » • * * » « » » » * TITLE FILE_NAME .GLOBL FNAME.IRAD50 FNAME: MOV MOV MOV MOV MOV INITST: MOV SOB R5,SAVE R4.-<SP) RO.-(SP) #6.R4 #STRING.R0 BLANK.(R0)+ R4.INITST ;SAVE THE LINK ;SAVE R4.R0 ; INITIATE THE STRING ;BY MOVING BLANKS IN TO IT GET THE DEVICE NAME: MOV 2(R5).R5 MOV 04 ,R4 DEVICE: CMPB #' : . (R5) + BEO NODFT1 SOB R4.DEVICE SUB #4.R5 DATA : MOV DK.STRING BR GETNAM NODFT t : CMPB *'0.-2(R5) BEO SYSTEM CMPB #'Y,-2(R5) BNE DATA SYSTEM: MOV SY.STRING ;R5 POINTS TO THE ASCII STRING ;GET THE DEVICE NAME DEFAULT=DK: R5 POINTS TO THE FIRST BYTE OF THE NAME DK = ' DK • ACCEPT O AND Y AS DYO OKO OR SY ALL OTHER CASES ARE TREATED AS DK: STRING IS TO BE PASSED TO IRAD50 AS THE FILENAME IN ASCII SY = -SY' GET THE NAME OF THE FILE: MOV MOV CMPB BEO #6 . R4 #STRING+3 .RO #'..(R5) N0DFT2 THE CHARACTERS BETWEN ARE THE FILE NAME CMPB #200,(R5) ; IF END OF THE STRING BEO FINISH ; THEN STOP MOVB (R51+,(R0)+ ; IT IS PUT TO A POSITION FROM 4 TH BYTE OF ;THE STRING SOB R4 . 1$ MOV *4 , R4 CMPB #'..(R5) ;IF IT HAS MORE THAN G BYTES THE REST IS BEO N0DFT2 :TRUNCATED INC R5 SOB R4 . 2$ BR FINISH :IF IT HAS MORE THAN 10 BYTES THE LETTERS ;AFTER .' ARE ASSUMED TO BE BLANK ; GET THE TYPE OF FILE: NODFT2 : MOV #3.R4 INC R5 SKIP THE '.' MOV #STRING*11.RO THE 3 BYTES AFTER '.' ARE MOVED 3$: CMPB #200.(RS) IF END OF THE STRING BEO FINISH THEN STOP MOVB (R5)+,(R0)+ SOB R4 . 3$ : FORM HAS BEEN ADJUSTED. CALL IRAD50 TO CHANGE IT TO RAD50 FINISH : MOV SAVE.R5 CALL IRAD50 TO PACK 12 BYTES TO MOV 4(RS).OUTAD MOV #LIST1,R5 OF RAD50 JSR PC.IRAD50 MOV (SP)+.RO .RESTORE R0.R4 MOV (SP )+.R4 RTS PC :RETURN .DATA FIELD: SAVE : .BLKW 1 ; THE LINK OF THE PARAMETER LIST STRING: . BLKW 6 ;12 BYTE BUFFER LIST1: OUTAD: . WORD . WORD WORD BLKW 3 ICNT STRING 1 ;CALL IRA050 ;ADDR. OF # OF BYTES ;ADDR. OF INPUT STRING :AODR. OF OUTPUT RAD50 STRING (8 BYTES) ICNT : WORD 12 . ;12 BYTES BLANK: DK : SY : .BYTE .ASCI I ASCI I . EVEN 40.40 /DK/ /SY/ ;END OF SUBROUTINE FNAME . END ,,,,,**,*..,**...,,....*...*...*.*•*•*••»*•* ro oo ******** .TITLE GLOBL .MCALL * * * * * * * * * * * HELP USER HELP .PRINT TO_ISSUE_COMMAND HELP: MOV RO,-(SP) ;SAVE RO 1$: .PRINT MOV SOB #MSG #77777.R5 R5, 1$ ;PRINT THE WAV OF ISSUING COMMANDS ;SET A DELAY TO OUTPUT ALL OUTPUT BUFFER MOV (SP)+.RO ;RESTORE RO RTS PC ;RETURN SUBROUTINE HELP VERSION 1.1 1-MAR-81 * * * * * * * * * * * * * * * * * * * * * * * * * * » * * * * * * * * * * * * * * * * * * * * * * * * * * * + * * * * * * * * * * « * * « * * * * * * * * FUNCTION OF THIS SUBROUTINE IS TO PRINT OUT SOME USEFUL INFORMATION ABOUT THE OPTIONS OF THE KEYBOARD INTERRUPTS AND DATA MANIPULATING COMMANDS TO HELP THE USER TO USE THE SYSTEM. NO NEED TO USE ANY PARAMETERS. DATA FIELD: ,MSG: ASCII ASCII .ASCI I ASCII ASCII ASCII ASCII .ASCI I ASCII .ASCI I ASCII .ASCI I ASCII . ASCI I .ASCI I ASCII ASCI I ASCII ASCI I .ASCI I .ASCI I ASCI I .ASCII ASCII .ASCI I .ASCI I .ASCII .ASCI I ASCII ASCI I .ASCI I <12x15>/THE FOLLOWING INFORMATION WILL HELP YOU TO ISSUE A/ / COMMAND./<12><15><12> / A. DURING DISPLAY:/<12><15> / 'ESC PASS CONTROL TO DATA MANIPULATION MOOE/<12><15> / '*' SCALE UP THE SUM OF THE SCANNED RESULT BY 2/<12x15> / '-' SCALE DOWN THE SUM OF THE SCANNED RESULT BY 2/ <12><15> / '«' STOP SCANNING AFTER FINISHED THE CURRENT SCAN/ <12><15x12> MOVE CURSOR UP/<12x15> MOVE CURSOR DOWN/<12><15> MOVE CURSOR RIGHT/<12><15> MOVE CURSOR LEFT/<12x15> RESET CURSOR POSITION AND THE SPEED/< 12x 15> SPEED UP THE MOVEMENT OF THE CURSOR/-: 12x 15> SLOW DOWN THE MOVEMENT OF THE CURSOR/<12x15><12> DISPLAY SPECTRUM l/<12><15> NOT DISPLAY SPECTRUM 1/<12x15> DISPLAY SPECTRUM 2/<12><1S> NOT DISPLAY SPECTRUM 2/<12><15> DISPLAY SPECTRUM 3/<12><15> NOT DISPLAY SPECTRUM 3/<12x15> DISPLAY SPECTRUM 4/<12x15> NOT DISPLAY SPECTRUM 4/<12x15x12> B. DURING PLOT:/<12><15> ' + ' SCALE UP SPECTRUM BY 2/<12x15> '-' SCALE DOWN SPECTRUM BY 2/<12><15> 'F' INCREASE PLOT SPEED BY 2/<12x15> 'S' DECREASE PLOT SPEED BY 2/<12><15> 0' OUIT /< 12x 15x 12> C. DATA MANIPULATION COMMANDS: '$' (FIRST 2 LETTERS ENOUGH)/ ASCI I < 12X 15> ASCI I / ADDSUB: ADD OR SUBSTRACT SPECTRA/<12><15> ASCI I / BACK : READ IN DATA FROM DISK/<12><15> ASCI I / CHANGE: CHANGE SOME POINTS OF A SPECTRUM/< 12x 15> ASCII / CLEAR: CLEAR OUT A SPECTRUM/<12><1S> ASCII / HELP: HELP USER TO ISSUE COMMANDS /<12><15> ASCII / INFO : GET OR CHANGE INFORMATION AND STATUS OF A / ASCI I /SPECTRUM/< 12x 15> ASCI I / LEVEL: LEVEL OUT SOME SPIKES OF A SPECTRUM/<12><1S> ASCI I / OUT : GET OUT OF THE DISPLAY MODE/< 12x 15> ASCII / PART : SHOW PART OF THE 4 SPECTRA OR PART OF A / ASCI I /SPECTRUM/<12><15> ASCII / PLOT : PLOT A SPECTRUM/<12><15> ASCI I / RELOAD: RELOAD THE DATA BEFORE THE LAST COMMAND TOOK ASCI I /PLACE/<12><15> ASCI I / SCALE: CHANGE THE SCALE OF A SPECTRUM/< 12x I5> ASCI I / SEPERA: MOVE A SPECTRUM UP OR D0WN/<12><15> ASCII / SHOW: SHOW THE VALUES OF SOME POINTS/< 12x 15> ASCI I / SMOOTH: SMOOTH A SPECTRUM/<12x15> ASCI I / SUM: SUM UP A SET OF SPECTRA IN ONE FILE/<12><15> ASCII / WRITE: WRITE A SPECTRUM TO DISK/<12x15> ASCI I / ' : NO INPUT, THEN JUST RETURN/<12><15x12> ASCI I /COMMAND 'HELP' FINISHED. GO BACK TO 'DISPLAY'./<12><15>< EVEN END OF SUBROUTINE HELP END SUBROUTINE IECHO VERSION 1.1 1-MAR-81 THE FUNCTION OF THIS SUBROUTINE IS TO ECHO A BINARY NUMBER IN ASCII FORM. THE RANGE IS FROM -9999 TO 9999. THE PRINTER WILL STOP RIGHT AFTER THE LAST DIGITAL BYTE. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS : LIST : 14 : WORD .BLKW TITLE .GLOBL .MCALL 1 1 * * * * * * * * * * * * * * * ECH0I4 CHARAC,IECHO .PRINT ;THE BINARY NUMBER TO BE ECHOED MOV MOV MOV MOVB MOV MOV JSR MOV RTS RO.-(SP) :SAVE RO BLANK.CHAR4 ;PUT 5 BLANK BYTES TO A STRING BUFFER 'CHAR4' BLANK,CHAR4*2 BLANK.CHAR4+4 2(R5).I4 ;CONVERT 14 TO ASCII DIGITAL BYTES #LIST1.R5 ; PC.CHARAC #CHAR4 (SP)+.RO PC ;PR1NT THE ASCII DIGITAL STRING ;RESTORE RO DATA FIELD: LI ST 1 : WORD 2 14: BLKW 1 WORD CHAR4+1 ; CALL CHARAC TO CONVERT BINARY TO ASCII ; THE BINARY DIGIT ; ADDRESS OF THE DIGITAL PART OF THE STRING .ASCII / / ;2 BLANK BYTES BLKB S :6 BYTES: 1ST BYTE IS A SIGN BYTE 20O : LAST BYTE IS 200 EVEN END OF SUBROUTINE IECHO END ro LD SUBROUTINE INFO VERSION 1.1 1-MAR-81 * • * * * • » * • * • * * * * * * « • * * * * • * * * * # * * * * * * * * * * * * * * * * * « * * * * * • * # * » » * « » » » * » . , . . . . , » , . . . THE FUNCTION OF THIS SUBROUTINE IS TO SHOW AND MODIFY THE INFORMATION TABLE AND THE SPECTRUM STATUS TABLE THE INFORMATION TABLE CONTAINS SOME RECORDS ABOUT HOW THE SPECTRUM WAS OBTAINED. THE SPECTRUM STATUS TABLE CONTAINS THE CURRENT MEMORY AND DISPLAY STATUS OF THE SPECTRUM. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: CALL A DATA MANIPULATING SUBROUTINE ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) X COORDINATE OF THE CURSOR Y COORDINATE OF THE CURSOR SCALE FACTOR USED FOR DISPLAY SUM OF SCANS THE DISPLAY MODE ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ADDRESS OF STACK) USED TO STORE THE SPECTRA TITLE INFORMATION_OF_A_SPECTRUM . GLOBL INFO.QUERY.EXTRAC.BINARY.IECHO MCALL .PRINT, GTLIN LIST: WORD 10. SAVE: .BLKW t XCUR : WORD 4095 YCUR : .WORD 0 FACTOR .WORD 0 MODE : BLKW 1 SPTAD1 BLKW 1 SPTAD2 .BLKW 1 SPTAD3 BLKW 1 SPTAD4 BLKW 1 STKAD1 BLKW 1 MOV ADD MOV R5.SAVE •12.R5 R5.M0DAD ;SAVE THE LINK ;R5 NOW POINTS TO 'MODE' ; MODAD - ADDRESS OF MODE SHOW THE CURRENT STATUS ON DISPLAY: URRENT• ;OUTPUT SPECT#'S OF CURRENTLY DISPLAYED SPECT PRINT *MSG1.1 MOV #0NE,R5 ;R5 POINTS TO A TABLE CONTAINING SOME MOV #1 ,R3 :R3 USED TO TEST IF SPECT_N IS IN MOV #4.R2 ;LOOP 4 TIMES CURIN: BITB R3.PM0DAD ;IF BIT_N=0. SPECTN NOT IN BEQ NOT IN PRINT R5 ;(4 BYTES FOR EACH NUMBER) NOT IN: ADD *4,R5 ASL R3 SOB R2.CURIN .PRINT R5 :PRINT A LINEFEED AND RETURN ;INPUT SPECTRUM NUMBER :. INPUT 1 MOV *LIST1,R5 ;INPUT SPECT* MOV #MSG1,STRGAD MOV #2.LIST1 MOV #ARGU1,ARGAD1 :ARGU1 - SPECT* TO BE INPUT JSR PC.EXTRAC MOVB ARGU1.R5 BICB *I777G0.R5 :R5 = N IN BINARY DEC ASL ADD ADD MOV MOV R5 R5 SAVE.R5 *14.R5 (R5),R5 R5.SPTADN :R5 NOW = OFFSET OF #SPTAD_N TO *SPTAD_1 ; R5 = *SPTAD_N ;R5 NOW POINTS TO THE SPECT STATUS TABLE : SPTADN POINTS TO THE SPECT STATUS TABLE SHOW INFORMATION TABLE: MOV MOV JSR TSTB BEQ MOV MOV MOV MOV ADD MOV MOV ADD ADD SOB #MSG1.2.QUESAD *LIST2.R5 PC.QUERY ANSWER STATUS *INFOT.R3 SPTADN.R5 12IR5).R4 #7 , R2 R3 (R3) + *22 (R4 ) + (R4)+.(R3) *2 .R3 *2.R4 R2 . 1$ ;ASK: 'WANT TO SEE THE INFORMATION TABLE?' ; I F 'NO' THEN GO SEE IF SHOW STATUS ELSE SHOW INFORMATION TABLE :R3 POINTS TO THE TABLE TO BE PRINTED ;R4=ADDRESS OF INFORMATION TABLE .OUTPUT 7 PARAMETERS :R3 POINTS TO THE POSITION OF THE ASCII * :MOVE IN THE ASCII NUMBER ;ADVANCE 2 BYTES FOR <12><15> ;ADVANCE 2 BYTES FOR COMMA AND BLANK PRINT *HDING1 ;PRINT HEADING AND INFORMATION TABLE 1$: MOV 12(R5).R4 ADD #62.,R4 CLRB 64.(R4) .PRINT #HDING2 .PRINT R4 THE INFORMATION TABLE: MOV #LIST2.R5 MOV #MSG2.QUESAD JSR PC.QUERY TSTB ANSWER BEQ 1$ .PRINT #MSG3 .PRINT R4 .GTLIN R4.#MSG4 PARAMETERS IN INFORMATI MOV *MSG5.QUESAD MOV *LIST2.R5 JSR PC.QUERY TSTB ANSWER BEQ STATUS .PRINT #MSG3 SUB #62..R4 MOVB 62 (R4).BUFFER CLRB 62.(R4 ) .PR INT R4 R4 POINTS TO INFORMATION TABLE AGAIN R4 POINTS TO THE DESCRIPTION FIELD STOP PRINTING HERE PRINT (' DESCRIPTION ') PRINT DESCRIPTION FIELD ;ASK: WANT TO CHANGE THE DESCRIPTION?' IF 'NO' THEN ASK IF CHANGE PARAMETERS ELSE PRINT ('OLD LINE:' ) PRINT OLD_LINE PRINT ('NEW LINE: ')THEN INPUT NEWLINE ;ASK: 'WANT TO CHANGE PARAMETERS?' THEN SEE IF WANT TO SEE STATUS ELSE CHANGE PARAMETERS AS ABOVE R4 POINTS BACK TO BEGINNING OF INFO STORE THIS BYTE TEMPORARY STOP PRINTING HERE ro _> ro GTLIN R4.#MSG4 ;GET A NEW LINE MOVB BUFFER.62.(R4) ;RESTORE THE ORIGINAL BYTE SHOW THE STATUS OF THE SPECTRUM: STATUS: MOV #MSG6.QUESA0 ;ASK: "WANT TO CHECK THE STATUS TABLE?' MOV #LIST2.R5 JSR PC.QUERY TSTB ANSWER ;IF 'YES-BNE 1$ THEN OUTPUT THE STATUS TABLE JMP OTHER : ELSE GOTO SEE IF ANOTHER SPECT REQUIRED i$: MOV SPTADN.R4 ;R4 POINTS TO STATUS TABLE MOV #BUFFER,R3 :R3 IS A BUFFER TO STORE THE PARAMETERS ; IN THE RIGHT ORDER MOV SAVE,R2 MOV 24(R2).R2 ;, R2 = ADDRESS OF THE STACK 1 SUB 20(R4).R2 NEG R2 ; R2 = POSITION OF THE SPECTN IN STACK 1 MOV R2.(R3> + ; 1 . LOCATION IN STACK MOV 22(R4).(R3)+ :2. START POINT* IN MEM MOV 10(R4),(R3)+ ;S. SIZE(WORDS) MOV #4095:.(R3) SUB 2<R4).(R3)+ ;4. START POINT* IN OSCIL MOV 4(R4),(R3)+ ;5. # OF POINTS MOV 6<R4),(R3>* :6. STEP~SIZE MOV 14(R4).(R3)+ ;7. SCALE FACTOR MOV 16(R4).(R3)+ ;8. SEPERATION_FROM_BASELINE MOV #3.R2 ;PRINT 3 MEMORY STATUS WORDS FIRST MOV #BUFFER,R3 ;R3 POINTS TO THE PARAMETER LIST PRINT #HDING3 ;PRINT THE HEADING MOV #STAT1.RO ;R0 POINTS TO THE STATUS ITEMS TO BE PRINTED MOV #LIST4.R5 MOV #2.Rt ;SECONDLY. PRINT DISPLAY STATUS 2$: PRINT RO ;PRINT HEADING MOV <R3)+.14 ;PRINT THE PARAMETER MOV #LIST4.R5 JSR PC.IECHO ADD #46.,R0 ;MOVE TO NEXT HEADING SOB R2.2$ MOV PRINT MOV SOB PRINT #5.R2 #HDING4 #STAT2.R0 Rl .2$ #BLANK ;PRINT 5 DISPLAY STATUS WORDS ;PRINT HEADING ;T0 WIPE OUT THE SECOND PRINT OF HDING4 CHANGE STATUS: MOV MOV JSR TSTB BEQ #MSG7.0UESAD #LIST2.R5 PC.QUERY ANSWER OTHER :ASK: 'WANT TO CHANGE STATUS?' ; IF ANSWER IS NO ; THEN SEE IF OTHER SPECTRUM IS REQUIRED INPUTS: MOV #MSG8.STRGAD ELSE INPUT NEW PARAMETERS MOV #ARGU1,ARGAD1 ;ARGU1 NOW IS THE START POINT* ON DISPLAY MOV #ARGU2.ARGAD2 ;ARGU2 IS # OF POINTS TO BE DISPLAYED MOV #ARGU3,ARGA03 ;ARGUS NOW IS THE STEP SIZE MOV #4,LIST1 ;THERE ARE 4-1=3 PARAMETERS MOV #LIST1.R5 JSR PC.EXTRAC :CONVERT TO BINARY: MOV #ARGAD1.R4 ;R4 POINTS TO A TABLE OF THE ADDRESSES OF THE PARAMETERS MOV #BUFFER.R3 ; R3 POINTS TO A BUFFER FIELD FOR BINARY # MOV #3.R2 ;THERE 3 PARAMETERS MOV #LIST3.R5 1$: MOV (R4)*.ASCIAD ;ASCIAD = ADDRESS OF THE ASCII DIGITAL STRING JSR PC.BINARY MOV BINUM,<R3)* ;CONVERT AND STORE THE BINARY TO BUFFER SOB R2.1$ ;STORE TO THE SPECTRUM STATUS TABLE: MOV SPTADN,R4 ;R4 POINTS TO THE SPECTRUM STATUS TABLE MOV -(R3).6(R4) :STEP_SIZE MOV -(R3).4(R4) :# OF POINTS TO BE DISPLAYED MOV #4095..2(R4) SUB -(R3).2(R4) jPOSITION OF 1ST POINT ON OSCILLISCOPE MOV (RS1.R3 ;R3 = ADDR. OF THIS POINT RELATIVE TO POINT 0 SUB 22(R4).R3 :R3 = ADDR. OF THIS POINT RELATIVE TO ; START_POINT IN THE MEMORY BGE 2$ :IF POSITIVE, THEN CONTINUE PRINT #MSG9 : ELSE PRINT 'POINT OUT OF RANGE ' BR OTHER : SET NO DIFFERENCE 2$: ASL R3 ;THIS OFFSET IS IN BYTES NOW DIV 6(R4).R2 ;R2 IS THE ACTUAL OFFSET IN MEMORY ADD 20(R4).R2 :R2 IS THE ACTUAL ADDRESS OF THE POINT IN MEM MOV R2.1R4) :THIS ADDRESS IS CALLED SPECTN IN TABLE ;CHANGE SCALE: CHSCAL: MOV #MSG9.1.QUESAD ;ASK: 'CHANGE SCALE?' MOV #LIST2,R5 JSR PC,QUERY TSTB ANSWER ;IF 'NO' BEQ OTHER : THEN GO SEE IF WANT TO CHECK OTHER SPECTRA MOV #2.LI5Tt ; ELSE INPUT NEW SCALE VALUE MOV #MSG9.2.STRGAD MOV #ARGU1.ARGAD1 ;ARGU1 NOW IS THE SCALE FACTOR MOV #LIST1.R5 JSR PC.EXTRAC MOV #ARGU1.ASCIAO :CONVERT IT TO BINARY CMPB #'-.ARGU1 :IF FIRST BYTE IS NOT '-' BNE 1$ : THEN JUST CONVERT IT INC ASCIAD : ELSE MOVE POINTER TO THE DIGITAL PART 1$: . MOV #LIST3.R5 JSR PC.BINARY MOV BINUM.141R4) ;STORE THE NEW SCALE :CHECK OTHER SPECTRUM: OTHER: MOV #MSG1O.QUESAD :ASK: 'WANT TO CHECK ANOTHER SPECTRUM?' ro L O C O MOV JSR TSTB BEO JMP #LIST2.R5 PC.QUERY ANSWER FINISH INPUT 1 IF ANSWER IS NO THEN STOP ELSE INPUT THE SPECTRUM » JOB DONE: FINISH 1$: .PRINT #MSG13 MOV #77777.R5 SOB R5.1$ RTS PC ;DATA FIELD: SAVE: BLKW 1 MODAD: .BLKW 1 SPTADN: .BLKW 1 BUFFER: BLKW 8. ;PRINT 'COMMAND 'INFO' FINISHED.' :SET A DELAY TO OUTPUT ALL OUTPUT BUFFER LINK OF THE PARAMETER LIST ADDRESS OF THE DISPLAY MODE IN 'DISPLA' ADDRESS OF THE SPECTRUM STATUS TABLE BUFFER FIELD FOR TEMPORARY STORAGE LI ST 1 : STRGAD: ARGAD1: ARGAD2: ARGAD3: . WORD BLKW .BLKW .BLKW .BLKW 4 1 1 1 1 CALL EXTRAC. # OF ARGUMENTS = 4 - 1 STRGAD = MESSAGE ADDRESS ADDRESS OF THE ARGUMENT ARGU1: ARGU2: ARGU3: .BLKW BLKW .BLKW 3 3 3 ARGUMENT IS A 6 BYTES BUFFER LIST2: OUESAD: ANSWER: WORD BLKW .BLKB EVEN 2 1 1 CALL QUERY TO GET A DECISION ADDRESS OF THE QUESTION RETURN ANSWER 0=NO 1=YES LIST3: ASCIAD: BINUM: . WORD . BLKW .BLKW 2 1 1 CALL BINARY TO CONVERT ASCII DIGIT ASCIAD - ADDRESS OF THE ASCII DIGIT RETURN BINARY NUMBER TO BINARY STRING LIST4: 14 : . WORD .BLKW 1 1 CALL I ECHO TO ECHO AN 14 NUMBER 14 IS THE BINARY NUMBER MSG 1 : ASCII /INPUT THE SPECTRUM # : /<200> MSG1.1: ASCII /SPECT#'S OF CURRENTLY DISPLAYED SPECTRA ARE : / .BYTE 200 MSG1.2: .ASCII /WANT TO SEE THE INFORMATION TABLE ABOUT THIS SPECTRUM? /<200> ONE : .ASCII / 1 /<200>/ 2 /<200>/ 3 /<200>/ 4 /<200>< 12>< 12>< 15x200> MSG2 ASCII < 12x 15>/WANT TO CHANGE THE DESCRIPTIONS? / BYTE 200 MSG3 : MSG4 : MSG5 : HDING1 INFOT: HDING2 MSG6 : HDING3 STAT 1 : HDING4 STAT2: BLANK: MSG7 : MSG8 : MSG9 : MSG9.1 MSG9.2 MSG 10: ASCII /OLD LINE: / BYTE 200 ASCII /NEW LINE: / BYTE 200 ASCII <12><15>/WANT TO CHANGE THE PARAMETERS? / BYTE 20O EVEN ASCII <12x15>/THE INFORMATION TABLE OF THIS SPECTRUM: /<12><15> ASCII / #_SPECT_IN_FILE: /<12><15> ASCII / SIZE(BLOCKS): /<12><15> ASCII / RATE(MSEC): /<12><15> ASCII / #_SCANS_PER_SPECT: /<!2x15> ASCII / START_POINT#: /<12><15> ASCII / #_POINTS_OBTAINED: /<12><1S> ASCIZ / STEP_SIZE: /<12><15> ASCIZ <12><15>/THE DESCRIPTION ABOUT THIS SPECTRUM IS: / ASCII <12><15>/WANT TO CHECK THE STATUS OF THIS SPECTRUM? /<200> ASCII <12x1S>/THE MEMORY STATUS OF THIS SPECTRUM:/<200> ASCII <12><15>/ RELATIVE POSITION IN STACK(BYTES): /<200> ASCII <12><1S>/ POINT* OF THE 1ST POINT IN MEMORY: /<200> ASCII -:12X15>/ SIZE OF MEMORY FOR THE SPECTRUM! WORDS) : /<200> ASCII < 12x 15X 12>/THE DISPLAY STATUS OF THIS SPECTRUM: /<200> ASCII <12><I5>/ POINT* OF THE 1ST POINT ON DISPLAY: /<200> ASCII <12><15>/ * OF POINTS BEING DISPLAYED: /<200> ASCII <12X15>/ STEP SIZE ON DISPLAY: /<200> ASCII <12><15>/ SCALEMOO FOR THE DISPLAY: /<200> ASCII <12><15>/ SEPERATION FROM THE BASELINE: /<200> ASCIZ <15>/ / ASCII <12x15> /YOU MAY MODIFY THE ST ARTPO I NT *. #_POINTS. STEP_SIZE/ ASCII / OF THE SPECTRUM SEGMENT/*12><15> ASCII /BEING DISPLAYED ON OSCILLISCOPE. WANT TO DO IT? / BYTE 200 ASCII /INPUT THE START_P0INT#. #_P0INTS. STEP_SIZE: /<200> ASCII /»•»«> THE SPECIFIED POINT* IS OUT OF RANGE. NOW TAKE THE / ASCIZ /MINIMUM./ ASCII <12><15>/THE SCALE OF A SPECTRUM WILL BE CHANGED BACK TO / ASCII /ONE BEFORE SCALING OR WRIT ING/< 12x 15> ASCII / THE SPECTRUM TO DISK /< 1 2x15> ASCII /YOU MAY CHANGE THE SCALE FACTOR HERE WITHOUT ACTUAL / ASCII /SCALING THE SPECTRUM./<12><15> ASCII /WANT TO DO THIS? /<200> ASCII /INPUT NEW SCALE*100: /<200> ASCII <12XI5>/WANT TO CHECK ANOTHER SPECTRUM? /<200> MSG 13: .ASCIZ /COMMAND 'INFO' FINISHED. BACK TO 'DISPLAY'./ EVEN !END OF SUBROUTINE INFO . END ro L O SUBROUTINE KYINHD VERSION 1.1 1-MAR-B1 FUNCTION OF THIS SUBROUTINE IS TO. UPON A DATA MANIPULATION REOUEST THROUGH A KEYBOARD INTERRUPT. SAVE THE CURRENT DATA BANK. THEN INPUT A COMMAND AND INTERPRET IT. THE CONTROL THEN WILL PASS TO A SUITABLE DATA MANI-PULATING SUBROUTINE TO PERFORM THE REOUIRED JOB. THE CURRENT DATA BANK IS SAVED IN TWO BACK UP FILES ON SYSTEM DISK AL-TERNATIVELY (SY:BKUP1.RCD AND SY:BKUP2.RCD). HENCE THE DATA BEFORE THE LAST DATA MANIPULATING COMMAND TOOK PLACE CAN BE RELOADED. THE RELOAD PROCESS IS DONE BY A DATA MANIPULATING COMMAND 'RELOAD'. TO ADD A NEW DATA MANIPULATING SUBROUTINE. ONE SHOULD: 1. DEVELOPE AND TEST THE NEW SUBROUTINE 2. ADD THE NAME OF THE SUBROUTINE TO THE GLOBLE LIST OF THIS SUBROUTINE 3. PUT THE FIRST TWO LETTERS OF THIS NAME TO THE COMMAND TABLE (CMDTBL:) 4. PUT THE NAME OF THE SUBROUTINE TO THE SUBROUTINE LIST (SUBLST:) IN THE SAME POSITION CORRESPONDED TO THAT IN THE COMMAND TABLE 5. PUT THE DOCUMENTATION OF THIS SUBROUTINE IN THE SUBROUTINE 'HELP' 1 ;THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: JUST: .WORD 10. CALL KYINHD :SAVE: BLKW 1 ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) ;XCUR: WORD 4095 . X COORDINATE OF THE CURSOR ;YCUR: WORD 0 Y COORDINATE OF THE CURSOR ;FACTOR WORD 0 SCALE FACTOR USED FOR DISPLAY SUM OF SCANS ;MODE: BLKW 1 THE DISPLAY MODE ;SPTAD1 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT 1 ;SPTAD2 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 :SPTA03 . BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ;SPTAD4 .BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ;STKAD1 .BLKW 1 ADDRESS OF STACK 1 USED TO STORE THE SPECTRA ***»******************************+*****»************************************ TITLE GLOBL .GLOBL GLOBL GLOBL .MCALL KEYBOARD INTERRUPT HANDLER OUT.KYINHD.EXTRAC BACK.ADDSUB,CLEAR.CHANGE.INFO LEVEL.SEPERA.PLOT.SMOOTH.HELP SHOW. SUM. STORE .WRITE . SCALE .PRINT ;ALL SUBROUTINES MANIPULATION FOR DATA MOV RS,SAVE ;SAVE THE LINK MOV #77777.R5 SOB R5. 1$ :SET A DELAY TO OUTPUT ALL OUTPUT BUFFER MOV RO.-(SP) :SAVE R0.R1.R2. R3.R4 MOV RI.-(SP) MOV R2,-(SP) MOV R3.-(SP) MOV R4.-(SP) BACKUP THE CURRENT DATA FIELD BEFORE CHANGING IT BY STORED IT IN DISK: MOVB #1.FLAG FLAG = 1 FOR SAVE. -0 FOR RELOAD BACKUP : MOV #LIST1,R5 JSR PC,STORE TSTB FLAG IF AFTER RELOAD. BEO END THEN GO OUT ELSE JUST CONTINUE TO GET INPUT COMMAND INPUT: MOV #LIST2.R5 JSR PC,EXTRAC INPUT COMMAND MOV ARGU1,R0 R0=1ST TWO CHAR OF THE COMMAND CMP RELOAD,RO IF THIS IS NOT A RELOAD INSTRUCTION BNE INTERP THEN GO TO INTERPRET THE COMMAND CLRB FLAG ELSE SET A FLAG BR BACKUP AND CALL STORE TO GET DATA BACK '; INTERPRET THE COMMAND: INTERP : MOV #CMDTBL.R1 Rl POINTS TO COMMAND TABLE MOV #SUBLST,R2 R2 POINTS TO SUBROUTINE ADDR,TABLE CMPB #200.RO IF NO INPUT BNE 1$ CLR RO THEN SET IT TO ZERO 1$ : CMP RO.(R1)+ SEARCH THE COMMAND AND GO TO CALL THE BEO CALSUB CORRESPONDING SUBROUTINE ADD #2,R2 BR 1$ CALSUB : MOV SAVE,R5 JSR PC.»(R2) CALL CORRESPONDING SUBROUTINE END : MOV #77777,R5 1$ : SOB R5 . 1$ SET A DELAY TO OUTPUT ALL OUTPUT BUFFER MOV ( SP1 + .R4 RESTORE R4.R3.R2.R1.RO MOV (SP)+.R3 MOV (SP)+.R2 MOV (SP)+.R1 MOV (SP)+.RO RT S PC DUMMY: .PRINT #MSG2 ARGU1 IS AT THE END OF THE COMMAND TABLE. ITS CORRESPONDING SUBROUTINE IS DUMMY. IT PRINTS 'INVALID COMMAND' RETURN .PRINT #MSG3 NO INPUT OR JUST 'RETURN' RTS PC : DATA FIELD: LIST 1 : . WORD 2 CALL STORE TO STORE THE DATA FIELD SAVE : . B.LKW 1 ADDRESS POINTS BACK TO PARA. LIST OF CALLING 'KYINHD' AND OTHER DATA MANIPULATING SUBR. FLAG: .BLKB 1 A FLAG - 1 FOR SAVE. - 0 FOR RELOAD . EVEN LIST2: . WORD 2 CALL EXTRAC TO GET THE COMMAND ro IX) cr. WORD MSG 1 : ADDRESS OF THE MESSAGE .WORD ARGU 1 ,ADDRESS OF COMMAND MSG3 : ASCII /NO OPERATION. BACK TO DISPLAY./<12x15xt2><200> . EVEN MSG 1 : ASCII /000M00000^0000000000000000000^000N00^000ftf/000000tt00tf000tttttt/ ;END OF SUBROUTINE KYINHD ASCI I /###########/<12><15> ASCII /NOW IN DATA MAN IPULATION MODE. TYPE IN COMMAND ./< 12x 15>/# / . END BYTE 20O . » + * * * * EVEN ;COMMAND NAME TABLE: RELOAD: ASCII /RE/ 'RELOAD' IS A SPECIAL COMMAND TO RELOAD DATA CMDTBL: ASCII /AD/ COMMAND TABLE ASCII /BA/ ASCII /CH/ ASCII /CL/ ASCII /HE/ ASCI I /IN/ ASCII /LE/ ASCI I /OU/ ASCII /PA/ ASCII /PL/ ASCI I /SC/ ASCI I /SE/ ASCI I /SH/ ASCII /SM/ ASCII /SU/ ASCI I /WR/ WORD 0 IF NO INPUT. COMMAND CHANGED TO ZERO ARGU 1 : BLKW 4 INPUT COMMAND IS STORED HERE IF COMMAND IS NOT FOUND IN COMMAND TABLE THEN IT WILL HEAD HERE AND CALL 'DUMMY' ;DATA MANIPULATING SUBROUTINE LIST: SUBLST: WORD ADDSUB ADDSUB WORD BACK BACK WORD CHANGE CHANGE WORD CLEAR CLEAR WORD HELP HELP WORD INFO INFO WORD LEVEL LEVEL WORD OUT OUT WORD INFO PART: INFO HAS ALL THE FEATURES FOR PART WORD PLOT PLOT WORD SCALE SCALE WORD SEPERA SEPERA WORO SHOW SHOW WORD SMOOTH SMOOTH WORD SUM SUM WORD WRITE WRITE WORD RETURN IF NO INPUT, THEN JUST 'RETURN' WORD DUMMY IF INVALID COMMAND. 'DUMMY' WILL BE CALLED TO PRINT AN ERROR MESSAGE MSG2 : ASCIZ /»»» INVALID COMMAND. TYPE 'HELP' IF CONFUSED./ ro LD SUBROUTINE LEVEL VERSION 1.1 1-MAR-81 * • * * * * * * • * * « . • * • * • * * * * * * * * * * * * * * » * * • * * * • * * * * * • * * * • * * * * * * * * " * * * * * * * * * * * * * * * * * * THE FUNCTION OF THIS SUBROUTINE IS TO TAKE OUT SOME SPIKES IN A SPECTRUM. A SPIKE IS DEFINED AS A POINT WHERE THE DIFFERENCE WITH THE RIGHT ONE AND THE DIFFERENCE WITH THE LEFT POINT BOTH EXCEEDS THE SPECIFIED CRITERIA. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: !LIST: WORD 10. CALL A DATA MANIPULATING SUBROUTINE ;SAVE: .BLKW 1 ADDRESS OF PARAMETER LI S T TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) ;XCUR: .WORD 4095. X COORDINATE OF THE CURSOR ;YCUR: .WORD 0 Y COORDINATE OF THE CURSOR ;FACTOR .WORD 0 SCALE FACTOR USED FOR DISPLAY SUM OF SCANS ;MODE: . BLKW 1 THE DISPLAY MODE ;SPTAD1 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 ;SPTAD2 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 :SPTAD3 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ;SPTAD4 .BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ;STKAD1 . BLKW 1 ADDRESS OF STACK 1 USED TO STORE THE SPECTRA INPUT : TITLE LEVEL OUT THE SPIKES GLOBL EXTRAC.BINARY.I ECHO.QUERY,LEVEL .MCALL .PRINT MOV R5.SAVE ;SAVE THE LINK ADD #14.R5 MOV R5.TABLSP ;TABLSP POINTS TO A TABLE OF ADDRESSES OF ; THE SPECTRUM STATUS TABLES MOV #LIST1,R5 :INPUT START POINT*. # OF POINT, LEFT JSR PC.EXTRACT :RIGHT DIFFERENCE. SPECT# MOV #ARGAD1.R4 .CONVERT ARGU1, 2. 3. 4 TO BINARY MOV #START.R3 MOV #4.R2 tSTORE AS START.NPOINT,LEFT.RIGHT MOV (R4)+.ASCIAD :ASCIAD = THE ADDRESS ASCII DIGITAL STRING MOV #LIST2.R5 JSR PC.BINARY MOV BINUM.(R3)* •BINUM = THE RETURNED BINARY NUMBER SOB R2. 1$ MOVB ARGU5.R5 BIC #177760.R5 ;R5 = SPECT* IN BINARY DEC R5 ASL R5 ;R5 • OFFSET FROM *SPTAD N TO #SPTAD_1 ADD TABLSP.R5 ;R5 = ADDRESS OF THE POINTER TO STATUS TABLE MOV (R5).R4 ;R4 POINTS TO THE SPECTRUM STATUS TABLE MOV 20(R4).R3 :R3 = HEAD ADDRESS OF SPECTN MOV START. R*1 SUB 22(R4).R1 ;R1 = POINT* OF N - POINT* OF 1ST POINT IN MEM BGE 2$ IF POSITIVE THEN CONTINUE .PRINT *MSG1.1 ELSE PRINT 'POINT OUT OF RANGE' CLR R 1 AND CLEAR DIFFERENCE 2$ : CLR RO ASL R 1 R1 NOW IN BYTES DIV 6(R4 ) ,RO RO = R1 / STEP SIZE ADD 20(R4).RO RO = ACTUAL ADDRESS OF STARTPOINT MOV NPOINT,R3 LPHEAD: MOV ( RO > + . R 1 SUB ( RO ) , R 1 MOV R 1 , R2 R2=LEFT_P0INT-CURRENT_P0INT TST R 1 BGE 2$ NEG R 1 R1=ABS(CURRENT POINT-LEFT POINT) 2$ : CMP R1.LEF r IF RKLEFT CRITERIUN BLT LPEND THEN-NO OPERATION MOV (RO).R1 ELSE SUB 2(R0).R1 SUB R 1 , R2 R2=(LEFT POINT-CURRENT POINT)-TST R 1 (CURRINT_POINT-RIGHT_POINT ) BGE 3$ NEG R1 R1=ABS(CURRENT POINT-RIGHT POINT) 3$ : CMP R 1 .RIGHT IF R1<RIGHT CRITERION BLT LPEND THEN NO OPERATION ELSE TST R2 BGE 4t NEG R2 R2=ABS(LEFT_P0INT+RIGHT_P0INT-2CURRENT) 4$: SUB LEFT.R2 SUB RIGHT.R2 R2=R2-(LEFT CRITERION+RIGHT CRITERION) BLT LPEND IF NEGATIVE THEN JUST A SLOPE, NOT A SPIKE MOV -2 (R0) . (R0) ELSE CURRENT POINT ADD 2(R0).(RO) =(LEFT_P0INT+RIGHT_P0INT)/2 ASR (RO) LPEND: SOB R3.LPHEAD UNTIL SEARCH OVER NPOINTS :JOB FINISHED: FINISH: .PRINT *MSG2 PRINT 'COMMAND 'LEVEL' FINISHED' RTS PC RETURN ;DATA FIELD: SAVE: BLKW 1 ;LINK OF THE PARAMETER LIST TABLSP: BLKW 1 ;TABLSP POINTS TO A TABLE OF THE POINTERS ; TO THE SPECTRUM STATUS TABLE . WORD . WORD . WORD .WORD . WORD . WORD 6 MSG 1 ARGU 1 ARGU2 ARGU3 ARGU4 ;CALL EXTRACT TO GET 5 INPUT PARAMETERS ro ARGADS: .WORD ARGU5 MSG 1: ASCII /SEARCH SPIKES. /< 12><15> ASCII /INPUT START_POINT#. *_POINTS, LEFTCRlTERI ON. / ASCIZ /RIGHT CRITERION. AND SPECT*. / EVEN L1ST2 WORD 2 ;CALL BINARY TO CONVERT ASCII TO BINARY ASCIAD: BLKW 1 :ASCIAD IS THE ADDRESS OF THE ASCII STRING BINUM BLKW 1 :BINUM IS THE RETURNED BINARY NUMBER START BLKW 1 ;START POINT* FOR THE SEARCH NPOINT: BLKW 1 ;# OF POINTS 10 BE SEARCHED LEFT : BLKW 1 ;LEFT CRITERION AS A SPIKE RIGHT BLKW 1 ;RIGHT CRITERION AS A SPIKE ARGU1 BLKW 3 :ASCII INPUT AS START ARGU2 BLKW 3 ;ASCII INPUT AS NPOINT ARGU3 . BLKW 3 ;ASCI I INPUT AS LEFT ARGU4 BLKW 3 :ASCII INPUT AS RIGHT ARGUS BLKB 2 ;ASCII INPUT AS SPECT* MSG 1 . ASCII /<»<><> THE SPECIFIED POINT IS OUT OF RANGE. NOW TAKF THE / .ASCIZ /MINIMUM / MSG2: ASCIZ /COMMAND 'LEVEL' FINISHED. GO BACK TO DISPLAY ' . / < 1 2 > '. 15 > END OF SUBROUTINE LEVEL END SUBROUTINE OUT V E R S I O N I . I I - N A R - S 1 1HE F U N C T I O N OF T H I S S U B R O U T I N E IS TO JUMP OUT OF THE I N F I N I T E D I S P L A * L O O P . THE P A R A M E T E R L I S T P A S S E D TO T H I S S U B R O U T I N E I S : L I S T : . WORD 1 0 . C A L L A DATA M A N I P U L A T I N G SUBROUT INE SAVE : . BLKW 1 A D D R E S S OF PARAMETER L I S T TO C A L L ' D I S P L A ' ( J U S T U S E D FOR FURTHER M O D I F I C A T I O N ) XCUR : . WORD 4 0 9 5 X COORDINATE OF THE CURSOR YCUR: . WORD 0 ¥ COORDINATE OF THE CURSOR F A C T O R : .WORD 0 S C A L E FACTOR U S E D FOR O I S P L A V SUM OF SCANS MOOE : . BLKW 1 THE D I S P L A Y MODE S P T A D 1 : . B L K W 1 A D D R E S S OF SPECTRUM S T A T U S T A B L E OF S P E C T 1 S P T A D 2 : . B L K W 1 A D D R E S S OF SPECTRUM S T A T U S T A B L E OF S P E C T 2 S P T A D 3 : .BLKW 1 A D D R E S S OF SPECTRUM S T A T U S T A B L E OF S P E C T 3 S P T A D 4 : . BLKW 1 A D D R E S S OF SPECTRUM S T A T U S T A B L E OF S P E C T 4 S T K A 0 1 : . B L K W 1 A D D R E S S OF S T A C K . U S E D TO STORE THE SPECTRA T I T L E o u r OF O I S P L A V G L O B L OUT O U T : ADO * 1 2 . R 5 MOV ( R 5 I + . R 4 ; R 4 « MODE MOV R 4 . M 0 D E : R 5 P O I N T S TO P O I N T E R OF S T A T U S T A B L E 1 MOV » 1 . R 3 ; R 3 • A O N E B I T B I T T E S T R E F E R E N C E : C L EAR OUT THE S E P E R A T I O N B E T W E E N THE B A S E L I N E AND THE S P E C T R A F I R S T : LOOP : B I T B R3 . R 4 IF THE S P E C T R U M IS NOT ON D I S P L A Y BEO NOT IN T H E N GOTO CHECK NEXT ONE MOV ( R 5 I , R 2 R2 P O I N T S TO S T A T U S TALBE MOV 2 0 < R 2 ) . R l R l - HEAD ADDRESS MOV 10(R2 ) . R O RO - S I Z E IN WORDS H : SUB ( 6 < R 2 ) . ( R t ) * C L E A R OUT THE S E P E R A T I O N SOB R O . » » CLR 16< R2 > U P D A T E THE S T A T U S T A B L E NOT IN : ADO # 2 . R 5 CHECK NEXT ONE A S L B R3 CMPB # 2 0 , R 3 IF C H E C K E D L E S S THAN 4 S P E C T R A BGE LOOP T H E N CHECK NEXT E L S E CONT INUE : R E STORE A L L R E G I S T E R S AND T R A C E BACK THE C O N T R O L : I t : ADD # 2 , SP V I R T U A L L Y R E T U R N TO MOV ( S P ) * R4 R E S T O R E R 4 . R 3 . R 2 . R 1 MOV ( S P ) * R3 IN ' K Y I N H D ' MOV ( S P ) * R2 MOV ( S P ) * R l MOV ( S P ) * RO ADD *2 . SP V I R T U A L L Y RETURN TO MUV ( SP )• R5 B 5 . R 0 ARE SAVEO IN MOV < SP l * RO ADD *4 . SP V I R T U A L L Y RETURN TO i s r R MODE IF SCAN IS OFF BGE »t THEN JUST RETURN ADD *4 . SP E L S E S K I P E F F E C T R l S PC R E T U R N ' KE V|NT' OF O I S P L A ' D I S P L A * ; D A T A F I E L D MODE: BLKW 1 : E N D Of S U B R O U T I N E OUT ; D I S P L A Y MOOE, B T H B I T - 1 IF S C A N IS ON END MOV (R2 )+.14 :PRINT THE DEFAULTED PARAMETER VALUE ****** ******* * • * • * « * * * * * * • * * * • « * * * * * * » * * * • * • « * * • * • * * * * * * * * * * • * » * * * * • * • • » • • • • * MOV #LIST1.R5 JSR PC.IECHO SUBROUTINE PARAME VERSION . 1 1-MAR-8 1 ADD *20.,R3 ;POINT TO NEXT ITEM SOB R1.PRDEFT ****** ******* • * • * * * * * • » * « • • « • « • * * * * • * • * * * • • • * • * * * • « * « • * » * * * • * • • * * * • * • • « » • * • • * .PRINT #MSG3 : PRINT '<12><15>' FUNCTI ON OF THIS SUBROUTINE IS TO INPUT SCANNING PARAMETERS, CONVERT THEM TO BINARY AND RETURN THESE VALUES. MOV #MSG4.QUESAD MOV #LIST2.R5 ;ASK:'ARE THE DEFAULT VALUES ACCEPTABLE? ' THE PARAMETER LIST PASSED THIS SUBROUTINE IS AS FOLLOWS: JSR PC.QUERY TSTB ANSWER ;IF ANSWER YES LIST: .WORD 5 5 ARGUMENTS(RATE,NSCAN.START.END.STEP) BNE FINISH : THEN RETURN RATE : BLKW 1 RATE OF SCAN IN MILLISEC NSCAN: .BLKW 1 NUMBER OF SCANS GET PARAMETERS STARPT . BLKW 1 WHERE TO START SCANNING NPOINT .BLKW 1 HOW MANY POINTS TO BE SCANNED GETPAR MOV SAVE,R2 STEP : BLKW 1 THE STEP SIZE OF THE OUTPUT VOLTAGE ADD #2.R2 :R2 POINTS TO #RATE(TABLE TO STORE PARAMETERS) SIZEWD BLKW 1 THE SIZE OF MEMORY ALLOCATED TO THIS SPECTRUM PRINT #MSG5 ;PRINT HEADING MOV #MSG1.1.MSGAD :NAME OF FIRST ARGUMENT(SAME AS ECHOED ONES) ****** ******* * * • * * * * * * * * • * * * * • * * * • . « « . * * * * • • * • * • • . * * . * * * * * * * * * * * * * * * * * * * * + * * * MOV *5.R1 ;R1 = ARGUMENT COUNT .TITLE GET SCANN NG PARAMETERS GLOBL BINARY.EXTRAC.I ECHO.QUERY,PARAME INPUT: MOV #LIST3,R5 :INPUT RATE,NSCAN,START,NPOINT.STEP .MCALL PRINT JSR PC,EXTRAC CMPB #200.ARGU ;TEST IF DEFAULT RAMP=170440 ;RAMP OUTPUT BUFFER REGISTER BEQ IS : THEN SKIP AND KEEP THE OLD VALUE X0UT =170444 ;X AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE MOV #LIST4,R5 ; ELSE CONVERT AND UPDATE THE NEW VALUE JSR PC.BINARY PARAME: MOV R5.SAVE ;SAVE THE LINK MOV NUMBER.(R2) MOV RO.-(SP) SAVE RO.R1.R2.R3 1$ : ADD #20..MSGAD ;POINTS TO NAME OF NEXT ARGUMENT MOV R1,-(SP) ADD #2 . R2 :ADVANCE THE POINTER MOV R2.-(SP) SOB R1.INPUT MOV R3,-(SP) CALCULATE THE SIZE OF MEMORY TO BE ALLOCATED TO THIS SPECTRUM IN WORDS: CHECK THE OUTPUT VOLTAGE RANGE: GETSZB CLR RO BEGIN: MOV #-1.SWITCH SWITCH BETWEEN MAXIMUM AND MINIMUM MOV -4 ( R2 ) . R 1 :-4(R2)=NP0INT PRINT #MSGO PRINT 'CHECK OUTPUT VOLTAGE RANGE' DIV #256..RO 2$: MOV #7777,RAMP SHOW MAXIMUM VOLTAGE OUTPUT TST R 1 ; IF NO REMINDER MOV RAMP.XOUT BEQ UPDSZB ;THEN JUST UPDATE SIZEBK BY QUOTIENT 1$: MOV #MAX +1,R1 R1 POINTS BETWEEN ADDRESSES OF MAX AND MIN INC RO ;ELSE SIZEBK=QU0TIENT*1 ADO SWITCH.Rl R1 NOW POINTS TO ADDRESS OF MAX OR MIN UPDSZB ASH #8..RO :R0 = SIZEWD (A MULTIPLE OF 256 WORDS) MOV (Rl).OUESAD ASK: 'WANT TO CHECK MAX/MIN VOLTAGE ?' MOV RO ( 2) :STORE SIZEWD MOV #LIST2.R5 (FIRST TIME SHOW MAX BUT ASK MIN) JSR PC.QUERY JOB DONE: TSTB ANSWER IF NO BEO RANGOK THEN GO TO RANGE OK FINISH MOV SAVE.R2 INITIALIZE XAX1S OF OSCILLOSCOPE NEG SWITCH ELSE IF SHOWING MINIMUM MOV #4095..R1 BLT 2$ THEN SWITCH MAXIMUM SUB G(R2).R1 ; AND VOLTAGE OUTPUT TO SPECTROMETER CLR RAMP ELSE SHOW MINIMUM VOLTAGE OUTPUT ; (R1=4096.-START_POINT) CLR XOUT MOV R1.XOUT BR 1» MOV R1.RAMP SHOW DEFAULT VALUE: :PRINT THE UPDATED PARAMETERS: .PRINT #MSG7 ;PRINT(' THE SCANNING PARAMETERS ARE: ') RANGOK: .PRINT #MSG1 ;PRINT(' THE DEFAULT SCANNING PARAMETERS ARE:' MOV #5. R 1 :R1=ARGUMENT COUNT MOV SAVE.R2 ADD #2 , R2 ;R2 = #RATE (A TABLE CONTAINING THE PARAMETERS) MOV #5,R1 R1=ARGUMENT COUNT MOV #MSG1.1.R3 :R3 POINTS TO THE MESSAGE ADD #2 . R2 R2=#RATE (A TABLE CONTAINING THE PARAMETERS) PRVALU PRINT R3 ;PRINT PARAMETER NAME MOV #MSG1.1.R3 R3 POINTS TO THE MESSAGE MOV (R2 )+. 14 ;PRINT THE DEFAULTED PARAMETER VALUE PRDEFT: .PRINT R3 PRINT PARAMETER NAME MOV "LIST 1,R5 JSR ADD SOB PRINT PC.IECHO #20.,R3 R1.PRVALU #MSG3 POINT TO NEXT ITEM PRINT -<12x15>' MOV MOV JSR TSTB BNE JMP #MSG6.OUESAD #LIST2.RS PC.OUERY ;ASK: 'SCAN NOW ?' ANSWER :IF YES. 1$ ; THEN GO BACK TO MAIN BEGIN ; ELSE GO TO BEGIN AGAIN MOV MOV MOV MOV (SP)*.R3 ;RESTORE R3.R2.R1.RO (SPI+.R2 (SP)*.R1 (SP)*.RO RTS PC RETURN ;DATA FIELD: SAVE : BLKW 1 ;LINK OF THE PARAMETER LIST LIST1 : 14 : . WORD BLKW 1 :CALL IECHO 1 LIST2: OUESAD: ANSWER: WORD .BLKW BLKW . EVEN 2 1 1 CALL QUERY ADDRESS OF OUESTION ANSWER BYTE LIST3: MSGAD: ARGAD: .WORD .BLKW .WORD 2 1 ARGU CALL EXTRAC ADDRESS OF MESSAGE ADDRESS OF ARGUMENT ARGU: BLKW 4 ARGUMENT IS A 8 BYTE BUFFER LIST4: STRGAD: NUMBER: WORD .WORD BLKW 2 ARGU 1 CALL BINARY ADDRESS OF THE STRING TO BE BINARY (NO SIGN) BINARY NUMBER CONVERTED TO SWITCH: MAX : MIN : BLKW WORD WORD 1 MSGO.1 MSG0.2 A SWITCH SWITCHING BETWEEN MAX: ADDRESS OF THE MESSAGE MIN: ADDRESS OF THE MESSAGE MSGO.1 TO MSGO.2 OF SHOWING MAX OF SHOWING MIN MSGO: ASCIZ < 12><15>/0UTPUT VOLTAGE RANGE CHECK:/ MSG0.1: ASCII /NOW SHOWING THE MAXIMUM OUTPUT VOLTAGE. / .ASCII /WANT TO CHECK MINIMUM? /<200> MSGO.2: .ASCII /NOW SHOWING THE MINIMUM OUTPUT VOLTAGE. / .ASCII /WANT TO CHECK MAXIMUM? /<200> MSG 1 : .ASCII <12x15>/THE DEFAULT SCANNING PARAMETERS ARE : /< 12>< 15x200:-MSG 1 1 : ASCII <12><15>/ RATE IN mSEC : /<200> MSG 1 2 : .ASCI I <12><15>/ # OF SCANS: /<200> MSG 1 3 : . ASCI I < 12x 15>/ START POINT*: /<200> MSG 1 4 : .ASCI I <12X15>/ # OF POINTS: /<200> MSG 1 5 : . ASCI I < 12x 15>/ STEP SIZE: /<200> MSG3 ASCIZ / / MSG4 ASCI I /ARE THE DEFAULT VALUES OK? / . BYTE 200 MSG5 .ASCI I <12>/INPUT NEW SCANNING PARAMETERS: (DEFAULT - OLD VALUE)/ ASCII <12x15x200> MSG6 ASCI I <12>/SCAN NOW? /<200> MSG7 .ASCI I <12x12x12x12x12x12x12x12xt2x12x12x12x12x12x12> ASCIZ /THE SCANN ING PARAMETERS ARE:/ .EVEN ; END OF SUBROUTINE PARAME . END SUBROUTINE PLOT VERSION 1.1 1-MAR-81 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * FUNCTION OF THIS SUBROUTINE IS TO PLOT A SPECTRUM. TWO VOLTAGES CORRESPONDED TO THE X AXIS AND Y AXIS ARE OUTPUT TO A PLOTTER. THE TIME OF THE PEN RESIDED AT A POINT IS A LINEAR FUNCTION OF THE DIFFERENCE BETWEEN THE VALUES OF THE CURRENT POINT AND THE NEXT POINT. THIS DELAY IS FURTHER ADJUSTED BY A SHIFTING FACTOR. A SPECIAL KEYBOARD INTERRUPT HANDLER IS LINKED TO HANDLE INTERRUPTS DURING PLOTTING. THE OPTIONS ARE: + ' TO SCALE UP THE PLOT BY 2 TO SCALE DOWN THE PLOT BY 2 F ' TO SPEED UP THE PLOT S' TO SLOW DOWN THE PLOT ' " 0' TO QUIT THE PLOT THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: LIST : WORD 10. SAVE : .BLKW 1 XCUR: .WORD 4095 YCUR: .WORD 0 FACTOR .WORD 0 MODE : BLKW 1 SPTAD1 BLKW 1 SPTAD2 .BLKW 1 SPTAD3 .BLKW 1 SPTAD4 .BLKW 1 STKAD1 .BLKW 1 « * » * * • * * • * * « * * ****** CALL A DATA MANIPULATING SUBROUTINE ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) X COORDINATE OF THE CURSOR Y COORDINATE OF THE CURSOR SCALE FACTOR USED FOR DISPLAY SUM OF SCANS THE DISPLAY MODE ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ADDRESS OF STACK 1 USED TO STORE THE SPECTRA .TITLE PLOT .GLOBL EXTRAC.QUERY.PLOT MCALL .PRINT DATA INITIALIZATION: CTCR = CTBR = CKCR = CKBR = RAMP = XOUT = YOUT = KEYCR KEYBR TTCR = 1677G2 167774 170420 170422 170440 170444 170442 =177560 = 177562 177564 COUNTER CONTROL REGISTER COUNTER BUFFER REGISTER REAL TIME CLOCK CONTROL REGISTER REAL TIME CLOCK BUFFER REGISTER RAMP OUTPUT BUFFER REGISTER X AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE Y AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE KEYBOARD INPUT CONTROL REGISTER KEYBOARD INPUT BUFFER REGISTER TERMINAL OUTPUT CONTROL REGISTER INPUT THE SPECTRUM NUMBER AND SPEED NUMBER: PLOT: MOV R5.SAVE ;SAVE THE LINK BEGIN: MOV #LIST1.R5 ;INPUT SPECT*.SPEED  JSR ,PC.EXTRACT MOVB ARGU1,R5 ;R5 = N IN ASCII BIC * 177760.R5 :R5 = N IN BINARY ASL R5 :R5 = OFFSET FROM SPTAD_N TO SPTAD1 + 2 ADD SAVE.R5 ADD #12.R5 ;R5 POINTS TO SPTAD_N MOV (R5 ) .R4 :R4=#SPECT_N MOV (R4 )+.R3 ;R3=START POINT MOV (R4)+.XOUT ;INITIALIZE VOLTAGE OUTPUT TO X AXIS MOV XOUT.RAMP AND VOLTMETER MOV (R3 ) .YOUT INITIALIZE Y AXIS BY THE 1ST POINT ;PLOT MOV #MSG2,OUESAD MOV »LIST2.R5 ;ASK:'IS IT THE PLOTTER READY NOW?' JSR PC.QUERY TSTB ANSWER :IF ANSWER: 'NO' BEQ FINISH ; THEN RETURN TO 'DISPLA' :ELSE PLOT: MOV (R4)+,R5 ;R5=NPT N DEC R5 :SHOW NPOINT-1 POINTS IN THE LOOP MOV ( R4).R4 ; R4=STEP_N MOVB ARGU2.R2 :ARGU2=SPEED# IN ASCII.LARGER # FASTER SPEED CMPB #200.R2 ;IF NO INPUT BNE 1$ CLR R2 ; THEN JUST SET SPEED CONTROL TO ZERO BR 3$ 1$: CMPB #'-.R2 ;IF NEGATIVE BNE 2$ MOVB ARGU2+1,R2 THEN MOVE THE DIGITAL PART IN 2$ : BIC #177760.R2 ;R2=SPEED IN BINARY CMPB #'-.ARGU2 ;IF NEGATIVE BEQ 3$ THEN LOWER THE SPEED. SO DON'T NEG R2 NEG R2 ;R2 USED AS SHIFTING FACTOR TO CONTROL SPEED 3$: CLR FACTOR :SET FACTOR TO ZERO :SET INTERRUPT HANDLER: MOV 9#60.INTBUF ;STORE THE ORIGINAL VECTOR MOV #KEYINT.»#60 MOV #100.KEYCR ;ENABLE INTERRUPT CLR »#62 :PLOT POINTS: PLOTLP: MOV (R3)*,R1 ASH FACTOR.R1 MOV R1,YOUT ;Y-AXIS=POINT(I)•2"'FACTOR MOV (R3 ) ,R1 ASH FACTOR.Rl SUB Y0UT.R1 TST R 1 BGE 1$ NEG R1 1$: ADD #100.R1 ;R1=100+ABS(Y AXIS(I-1)-Y AXIS(l)) ASH R2 . R 1 ; REDUCE THIS BY 2"R2 BECAUSE R2 IS NEGATIVE o NEG MOV MOV CMP BNE SUB SUB SOB MOV ASH MOV R1 R1 , CKBR *4 1 .CKCR *240.CKCR DELAY R4.XOUT R4.RAMP RS.PLOTLP (R3),R1 FACTOR.Rl R1 . YOUT THE CLOCK COUNTS UP TO ZERO, SO NEGATE R1 INITIALIZE THE BUFFER REGISTER OF THE CLOCK START COUNTING ;OUTPUT X_AXIS(I+1) :VOLTMETER(I*1) ;UNTIL NPOINT-1 POINTS HAVE BEEN PLOTTED ;SHOW THE LAST POINT JOB DONE: FINISH: MOV CLR MOV MOV JSR TSTB BNE JMP 1$: PRINT RTS INTBUF . »*60 »#62 *MSG4.QUESAD *LIST2.R5 PC.OUERY ANSWER 1$ BEGIN *MSG3 PC ;MOVE OUT INTERRUPT HANDLER OF THIS ROUTINE ;ASK: 'STOP NOW?' ;IF 'YES' ; THEN STOP ; ELSE PLOT AGAIN ;PRINT 'COMMAND 'PLOT' FINISHED. ; RETURN TO DISPLA' KEYBOARD INTERRUPT HANDLE OF THE PLOTTING ROUTINE: 3$: CLR MOV CMPB BNE DEC BR CMPB BNE INC BR CMPB BNE INC BR CMPB BNE DEC BR CMPB BNE MOV ADD JMP KEYCR #*KEYBR,RO #'F.RO 1$ R2 RETURN *'S.RO 2$ R2 RETURN * ' + . RO 3$ FACTOR RETURN * ' - . RO 4$ FACTOR RETURN *'Q.RO RETURN *1O0.»*KEYCR #4 . SP FINISH DISABLE FURTHER INTERRUPT RO=THE KEY PRESSED IF NOT 'F' THEN COMPARE OTHERS ELSE MAKE R2 MORE NEGATIVE TO FASTEN SPEED IF NOT 'S' THEN COMPARE OTHERS ELSE MAKE R2 LESS NEGATIVE TO REDUCE SPEED IF NOT '•' THEN COMPARE OTHERS ELSE INCREASE FACTOR TO ENLARGE YAX1S IF NOT '-' THEN COMPARE OTHERS ELSE REDUCE FACTOR TO REDUCE YAXIS IF NOT 'Q' (QUIT) THEN RETURN 70 PLOT ELSE RETURN ABNORMALLY TO THE END OF PLOT RETURN: MOV RT I *100,e#KEYCR ;ENABLE THIS INTERRUPT HANDLER AGAIN ;RETURN TO INTERRUPT POINT ; DATA FIELD: SAVE : .BLKW 1 ;LINK TO THE PARAMETER LIST FACTOR .BLKW 1 :SCALE FACTOR FOR THE PLOTTER INTBUF BLKW 1 ;BUFFER STORES THE ORIGINAL INTERRUPT VECTOR LIST) : . WORD 3 ;CALL EXTRAC WORD MSG 1 WORD ARGUt WORD ARGU2 ARGU1 : BLKB 2 * ; SPECTRUM * ARGU2: BLKB 2 ;SPEED # LIST2: . WORD 2 QUESAD . BLKW 1 ANSWER BLKB 1 MSG 1 : .ASCI I /INPUT SPECT* TO BE PLOTTED AND SPEED* (LARGER.FASTER,EG . 4)/ .ASCI I /: /<200> MSG2: ASCII /IS THE PLOTTER READY NOW? / . BYTE 200 MSG3 : .ASCIZ /COMMAND 'PLOT' FINISHED. GO BACK TO 'DISPLAY'./ MSG4 : ASCI I /STOP NOW? /<200> . EVEN ; END OF SUBROUTINE PLOT . END SUBROUTINE OUERV VERSION 1.1 1-MAR-81 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * FUNCTION OF THIS SUBROUTINE IS TO PRINT A OUESTION AND INPUT AN ANSWER. IF THE ANSWER IS 'YES'. THEN IT RETURNS A FLAG AS '1'. IF THE ANSWER IS 'NO'. THEN IT RETURNS A FLAG AS '0'. OTHERWISE. IT ASKS THE OUESTION AGAIN. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS AS FOLLOWS: LIST: WORD 2 OUESAD: .BLKW 1 ;ADDRESS OF THE OUESTION ANSWER: BLKB 1 ;RETURN ANSWER 0=N0 1=YES .EVEN * * * • • * * • * » * * * * * * * * * * » * * * + # * * * * * * * * • + * * * * • » • * • * » * * * * * » * * * * * * + * * * * * « * * + * * • • * * * * TITLE OUERY_AND_GET_YES/NO .GLOBL QUERY .MCALL .PRINT. GTLIN QUERY: MOV RO.-(SP) SAVE RO MOV R5.SAVE MOV 2(R5),R5 ASK : GTLIN •ANSWER.R5 PRINT THE QUESTION AND GET THE ANSWER MOV •ANSWER,RO It: CMPB #' .(R0)+ SKIP THE PRECEEDING BLANKS BEQ 1t CMPB #'Y,-(RO) IS ANSWER Y? BEQ YES YES.THEN GO TO YES CMPB #171,(RO) IS ANSWER y? BEO YES YES,THEN GO TO YES CMPB #'0. (RO) IS ANSWER 'OK' BEO YES YES, THEN GO TO YES CMPB #157.(RO) IS ANSWER 'ok' BEQ YES YES THEN GO TO YES CMPB #'N.(RO) IS ANSWER N? BEO NO YES THEN GO TO NO CMPB #156.(RO) IS ANSWER n? BEO NO YES. THEN GO TO NO BR ASK OTHERWISE GO AND REPEAT THE QUESTION YES: MOV SAVE,R5 MOVB #1,4(R5) IF AFFIRMATIVE ANSWER SET FLAG TO 1 BR RETURN RESTORE AND RETURN NO: MOV SAVE.R5 CLRB 4(R5) IF NEGATIVE SET FLAG TO 0 RETURN: MOV (SP)*.RO AND RESTORE RO RTS PC RETURN ;DATA FIELD: SAVE: BLKW 1 ;LINK TO THE PARAMETER LIST ANSWER: BLKW 10 ;BUFFER TO STORE THE ANSWER STRING END OF SUBROUTINE QUERY . END O J o SUBROUTINE SCALE VERSION 1.2 30-MAR-81 • *•**•*•***•**•»***•* + *****•*************** + * + **** + ••**•****••"""*"""*'" FUNCTION OF THIS SUBROUTINE IS TO CHANGE THE SCALE OF THE DISPLAYED PORTION OF A SPECTRUM AS SPECIFIED BY THE USER (INPUT SCALE*100. SO THAT CAN BE SCALED TO THE SECOND DECIMAL PLACE). THE SPECTRUM WILL BE SCALED BACK TO UNITY (SCALE*100 = 100) FIRST. BE-FORE SCALING TO THE NEW FACTOR. OVERFLOW WILL BE CHECKED. USER'S DECISION WILL BE ASKED IF OVERFLOW OCCURS. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: JLIST: WORD 10. CALL A DATA MANIPULATING SUBROUTINE ;SAVE : .BLKW 1 ADDRESS OF PARAMETER LIST TO CALL 'OISPLA' (JUST USEO FOR FURTHER MODIFICATION) ;XCUR: .WORD 4095 . X COORDINATE OF THE CURSOR ;YCUR: WORD O Y COORDINATE OF THE CURSOR :FACTOR .WORD 0 SCALE FACTOR USED FOR DISPLAY SUM OF SCANS ;MODE: BLKW 1 THE DISPLAY MODE ;SPTAD1 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT1 ;SPTAD2 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 ;SPTAD3 .BLKW 1 AODRESS OF SPECTRUM STATUS TABLE OF SPECI3 ;SPTAD4 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 ;STKAD1 .BLKW 1 ADDRESS OF STACK 1 USEO TO STORE THE SPECTRA • » * * . * * * * » » * * * * * * * * * * » * * * * • * * * * • * * * * * * * * * * * * * » * * * * * * * • * * * * * * • * * * * * * * * * * * * * * * * .TITLE SCALE SPECIF ED_SPECTRA .MCALL .PRINT GLOBL IECHO.EXTRAC BINARY.SCALE.QUERY ADD #12.R5 MOV (R5)+.M0DE MOV R5.TABLSP :TABLSP POINTS TO POINTERS OF STATUS TABLES MOV #1.TSTBIT MOV #1.SPECTN : MOV SPECTN.R4 :FETCH ADDRESS OF SPECTRUM PARAMETERS DEC R4 ASL R4 ADD TABLSP.R4 ;R4 POINTS TO POINTERS OF STATUS TABLE N MOV (R4),R4 ;R4 POINTS TO STATUS TABLE N CLRB FLAG ;CLEAR FLAG SO THAT OVERFLOW WILL BE TESTED BIT TSTBIT.MODE ;TEST IF SPECTRUM IS BEING DISPLAYED BNE AROUND JMP NOTHIS PRINT #MSG1 ;PRINT THE SCALE OF SPECTRUM MOV SPECTN.14 MOV #LIST1.R5 JSR PC,IECHO :PRINT SPECTRUM NUMBER .PRINT #MSG2 ;PRINT "IS" MOV 141 R4 ) . 14 :FETCH SCALE FACTOR MOV #LIST1.R5 JSR PC.IECHO ;PRINT SCALE FACTOR PRINT #MSG3 PRINT <CRxLR> MOV #LIST2.R5 JSR PC.EXTRAC CMPB #200,ANS BEQ NOTHIS ASK FOR NEW SCALE FACTOR NO ENTRY-DO NOT CHANGE SPECTRUM INC : NOT INC: MOV #ANS.ADDRNO CMPB ANS.#053 BEQ INC CMPB ANS.#055 BNE NOT INC INC ADDRNO MOV #LIST3,R5 JSR PC.BINARY CMP NEWSCA. 14(R4 ) BEO NOTHIS ;SET UP STRING ADDRESS TO CONVERT TO BINARY CHECK IF SIGN BIT PRESENT 053 = + 055 = -THEN POINT TO BYTE AFTER SIGN CONVERT SCALE FACTOR TO BINARY IF NEW SCALE FACTOR SAME AS OLD DON'T CHANGE SPECTRUM MOV MOV TSTB BEO SUB (R4),R3 4(R4),R2 FLAG OLDSCA N0TDID.R2 FETCH ADDRESS OF FIRST POINT TO BE CHANGED FETCH NO.OF POINTS DISPLAYED IF NO OVERFLOW OCCURRED AND A RESTART THEN RESET ALL POINTS ELSE RESET ONLY THE CHANGED POINTS OLDSCA: MOV SUB CLR MUL DIV MOV SOB (R3),RO 16(R4).RO R 1 #100..RO 14(R4),R0 RO.(R3) + R2.OLDSCA : FETCH FIRST POINT ;SUBSTRACT SEPARATION REMOVE SCALE FACTOR STORE VALUE R2 CONTAINS NO.OF POINTS :SCALE: SCALP: : MOV 4( R4).R2 FETCH NO.OF POINTS DISPLAYED MOV (R4 ) ,R3 FIRST ADDRESS OF FIRST POINT MOV NEWSCA.14(R4) STORE NEW SCALE FACTOR CLRB FLAG CLEAR THE FLAG SO OVERFLOW WILL BE CHECKED MOV (R3),R0 FETCH VALUE CLR R 1 32BIT MULTIPLICATION MUL NEWSCA.RO COMPUTE NEW VALUES DIV #100..RO BVC 1$ OVERFLOW? IF NOT, GOTO 1$ AND CONTINUE TSTB FLAG IF NOT FIRST TIME OF OVERFLOW BNE 1$ THEN CONTINUE TO DO IT MOV R2.N0TDID NOTDID = # OF POINTS HAVE BEEN DONE INCB FLAG ELSE SET FLAG AND ASK USER'S DECISION MOV #LIST4,R5 ASK: 'DATA OVERFLOWED. STILL WANT TO DO IT? JSR PC.QUERY C O o cn TSTB BNE BR ADD MOV SOB ANSWER H AROUND 1G(R4).RO RO,(RS) + R2.SCALP IF 'YES' THEN CONTINUE ELSE TRY AGAIN : ADD SEPARATION .STORE VALUE ASL INC CMP BLT JMP PRINT RTS TSTBIT SPECTN #4,SPECTN RETURN NEXTSP *MSG5 PC ;GO TO NEXT SPECTRUM :PRINT 'COMMAND 'SCALE' FINISHED. DATA FIELD: TABLSP: BLKW 1 ; ADDRESS POINTS TO POINTERS OF STATUS TABLES NOTDID: BLKW 1 ;NO OF POINTS REMAINED UNCHANGED LI ST 1 : 14 : WORD WORD 1 ;CALL I ECHO TO ECHO AN 14 NUMBER O ;NUMBER TO BE ECHOED MSG 1 : MSG2 : MSG3 : ASCII ASCII .ASCI I EVEN /THE SCALE*100 OF SPECTRUM /<200> / IS /<200> <12><15x200> LIST2: WORD .WORD WORD 2 MSG 10 ANS CALL EXTRAC TO INPUT NEW SCALE FACTOR ANS : MSGtO: BLKB ASCI I .ASCI I EVEN 6 /PLEASE ENTER NEW SCALE VALUE: (MOO) / <200> SPECTN: MODE : TSTBIT: LISTS: ADDRNO: NEWSCA: BLKW .BLKW .BLKW .WORD .BLKW BLKW 1 1 1 2 1 1 SPECTRUM NUMBER TO BE ALTERED SPECIFIES SPECTRA BEING DISPLAYED TESTS WHICH BITS IN MODE ARE SET LIST4: OUESAD: ANSWER: WORD WORD .BLKB 2 MSG4 1 CALL QUERY TO ASK USER'S DECISION ADDRESS OF THE OUESTION RETURNED ANSWER 0-NO. 1=YES MSG4: .ASCII /»<»?> SCALE TOO LARGE. DATA OVERFLOWED. STILL WANT TO DO IT? / .BYTE 200 MSG5: .ASCIZ /COMMAND 'SCALE' COMPLETED. GO BACK TO 'DISPLAY'./ FLAG: .BLKB 1 :A FLAG. IF 0 DETERMINE OVERFLOW, ELSE NOT .EVEN ;END OF SUBROUTINE SCALE . END SUBROUTINE SCAN VERSION 1.1 1-MAR-81 THE FUNCTIONS OF THIS SUBROUTINE ARE TO SUPERVISE THE FOLLOWING PROCESSES: A) A REAL TIME CLOCK MEASURES A SPECIFIED TIME DURATION B) A COUNTER COUNTS SOME PULSES C) SUBROUTINE DISPLA TO SHOW THE CURRENT SCANNING RESULT D) A MAIN PROCESS TO SET UP THESE PROCESSES. JUDGE THE FLOW OF CONTROL. AND OUTPUT A RAMP VOLTAGE TO THE SPECTOMETER. THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS :LIST: WORD WORD .WORD WORD 3 L I ST 1 LIST2 LISTS HOW TO SCAN WHERE TO STORE IN MEMORY WHERE TO STORE IN DISK THE ABOVE LISTS ARE: LIST 1 : RATE : NSCAN: STARPT: NPOINT: STEP : SIZEWD: WORD .BLKW .BLKW .BLKW BLKW .BLKW .BLKW 5 ARGUMENTS!RATE.NSCAN.START.END,STEP) RATE OF SCAN IN MILLISEC NUMBER OF SCANS WHERE TO START SCANNING HOW MANY POINTS TO BE SCANNED THE STEP SIZE OF THE OUTPUT VOLTAGE THE SIZE OF MEMORY ALLOCATED TO THIS SPECTRUM LIST2: MODAD: WORD .WORD 7 MODE .STKAD1 WORD STACK 1 ADDRESS OF ;SPTAD1 .WORD SPECT1 ADDRESS OF :SPTAD2 .WORD SPECT2 ADDRESS OF :SPTAD3 WORD SPECT3 ADDRESS OF ;SPTAD4 .WORD SPECT4 ADDRESS OF ;FLAGAD .BLKW 1 ADDRESS OF SAME ADDRE LIST SS OF BIT BIT BIT BIT BIT AS THAT FOR CALLING DISPLA THE DISPLAY MODE 1 = 1 SPECT1 IS TO BE DISPLAYED 2 = 1 SPECT2 IS TO BE DISPLAYED 3 = 1 SPECTS IS TO BE DISPLAYED 4 = 1 SPECT4 IS TO BE DISPLAYED 9 = 0 A NEW SCAN 1 RESTART A TERMINATED JOB TO GET MORE SCAN (SEE SUBROUTINE SCAN) 8 = 0 SCAN IS OFF 1 SCAN IS ON (SPECT2 IS THE RESULT) STACK 1 THE STATUS TABLE OF SPECTRUM 1 THE STATUS TABLE OF SPECTRUM 2 THE STATUS TABLE OF SPECTRUM 3 THE STATUS TABLE OF SPECTRUM 4 A FLAG FOR COMMUNICATION BETWEEN 'SCAN' AND DISPLA' : LIST3: ; FNAMAD: ; DSTART: ; DADDR: ;DSIZE: ; DSTATU: WORD .BLKW BLKW BLKW BLKW BLKB . EVEN FILENAME ADDRESS STARTING BLOCK NUMBER STARTING ADDRESS OF THE DATA FIELD TO BE USED * OF BLOCKS TO BE TRANSFERED STATUS: BIT 1=1 IF WRITE TO DISK , BIT 1=0 IF READ FROM DISK UPON RETURNED: NEGATIVE IF FAILED TITLE SCANDATA GLOBL SCAN,DISK.I ECHO.CHARAC,DISPLA .MCALL .PRINT..GTLIN CTCR=1 CTBR= 1 CKCR= 1 CKBR=1 CKPC=4 CKPS=4 RAMP=1 XOUT=1 YOUT=1 677G2 G7774 70420 70422 40 42 70440 70444 70442 KEYCR=177560 KEYBR=177562 TTCR=177564 TTBR=177566 IVECTR=60 ISTATU=62 COUNTER CONTROL REGISTER COUNTER BUFFER REGISTER REAL TIME CLOCK CONTROL REGISTER REAL TIME CLOCK BUFFER REGISTER REAL TIME CLOCK INTERRUPT VECTOR REGISTER REAL TIME CLOCK INTERRUPT STATUS REGISTER RAMP VOLTAGE OUTPUT BUFFER REGISTER X AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE Y AXIS OUTPUT BUFFER REGISTER TO OSCILLISCOPE KEYBOARD CONTROL REGISTER KEYBOARD BUFFER REGISTER TERMINAL CONSOL OUTPUT CONTROL REGISTER TERMINAL CONSOL OUTPUT BUFFER REGISTER SYSTEM KEYBOARD INTERRUPT VECTOR SYSTEM KEYBOARD INTERRUPT STATUS 1$: ADD #2.R5 MOV (R5)+,TABLE 1 TABLE 1 : HOW TO SCAN (LIST2 OF MAIN) MOV (R5)+,TABLE2 TABLE2: HOW TO STORE IN MEM (LISTS) MOV (R5).TABLES TABLE3: HOW TO STORE IN DISK (LIST5) SEE THE DATA FIELD FOR DETAILS MOV TABLE2.R5 ADD *2 , R5 BIS *202.(»(R5) SET SCAN ON AND DISPLAY SPECT2 BIT #400.»(R5)+ IF JUST CONTINUE TO GET MORE SCANS BNE 1$ THEN KEEP NSCNOB(# OF SCANS OBTAINED) CLR NSCNOB ELSE CLEAR IT MOV (R5)+.STKAD1 STKAD1=#STACK1 MOV (R5)+,TABLE4 TABLE4 = SPECTRUM STATUS TABLE OF SPECT1 MOV (R5)+.TABLES TABLES = SPECTRUM STATUS TABLE OF SPECT2 MOV #FLAG1,4(R5) SET UP THE FLAG ADDRESS AND COMMUNICATE WITH 'DISPLA' CLRB FLAG1 MOV TABLE 1,RS (RS)=#LIST2 ADD *2 , RS (R3)=#RATE > THE CLOCK BUFFER: MOV (R3)+.CKBR MOVE RATE TO CLOCK BUFFER NEG CKBR COUNT UP UNTIL ZERO : GET SCANNING PARAMETERS: MOV MOV MOV MOV MOV MOV ASL (R3)+.NSCAN (R3)».START (R3)+.NPOINT (R3)+.STEP (R3).SIZEWD SIZEWD.SIZEBY SIZEBY ;GET A COPY OF THE SCANNING PARAMETERS :SIZEBY = SIZE OF SPECTRUM IN BYTES :INITIALIZE THE SPECTRUM STATUS TABLES OF THE SPECTRUM 1 AND 2. STATUS: MOV TABLE4.R3 :RS POINTS TO STATUS TABLE OF SPECT1 MOV TABLES.R1 Rl POINTS TO STATUS TABLE OF SPECT2 ( •'NOTE : R3 .R4 SHOULD NOT BE USED IN DISPLA' WHILE SCANNING) MOV STKAD1,(R3)+ SPECT 1 = #STACK1 MOV STKAD1, <R1 ) SPECT2 = #STACK1 + SIZEBYOFSPECT1 AFTER SCANNING ALL REQUIRED SCANS. CONTROL IS STILL IN DISPLA'. ADD SIZEBY.(R1) + THE USER IS ASKED TO INTERRUPT IT AND USE THE 'OUT' COMMAND TO MOV #4095..(R3) PASS THE CONTROL BACK TO THE CALLING ROUTINE. IN THIS CASE 'SCAN'. SUB START.(R3) BEGIN1=4096.-START MOV (R3).(R1)+ BEGIN2=BEGINI MOV (R3 )+.RAMPST (INITIALIZE THE RAMP OUT) OUTPUT THE INFORMATION BLOCK OF THIS SET OF SPECTRA TO BLOCK 0 OF THE FILE: MOV RAMPST.RAMP (RAMPST IS ANOTHER COPY OF BEGIN 1> MOV NPOINT,(R3) + NPT1=NP0INT INFOUT: MOV TABLE4.R5 ;R5=#SPECT1 MOV NPOINT, (Rt )<• NPT2=NP0INT MOV TABLE3.R4 ;R4 POINTS TO PARAMETER LIST FOR DISK MOV STEP.(R3)+ STEP1=STEP ADD #4 , R4 ;R4=#DSTART MOV STEP.(R1) + STEP2=STEP CLR (R4 ) + :PUT INFORMATION TO 1ST BLOCK OF DATA MOV SIZEWD.(R3)+ SIZWD1=SIZEWD MOV INF01, ( R4) + ;PUT ADDRESS OF INFO TABLE 1 TO DADDR MOV SIZEWD.(Rl) + SIZWD2»SIZEWD MOV #64. .< R4 ) + ;DSIZE=64. MOV (R3)+.INF01 INF01=ADDR OF INFO TABLE OF SPECT1 MOVB #1.(R4 ) ;SET UP WRITE MODE MOV (R1)+,INF02 T t i c n n - . n n n n c T k i c r n DI C nC CDCTT) INF02-AUUH Ur INrU 1AbLt Ur bKCL1^  MOV #100.(R3) + SET THE INITIAL SCALE FACTOR •= 100 ;UPDATE INFORMATION TABLE: MOV #100.(R1)+ MOV TABLE 1.R3 ;R3 POINTS TO SCANNING INFO TABLE CLR (R3) + SEPER1=0 MOV #TABLE6.R2 ;SET UP A TABLE CONTAINING THE INFO CLR (R1) + SEPER2=0 MOV NSCNOB. (R2 ) + PARAMETERS IN RIGHT ORDER MOV STKAD1,< R3)* HEAD 1=STKAD1 ;1. # SPECT=NSCAN MOV STKAD1.(Rl) HEAD2=STKAD1+SIZEWD*2 MOV 14(R3 >,RO ;2. SIZE IN # OF BLOCKS ADD SIZEBY.< Rl) + ASH #-B.,RO ; 1 BLOCK = 256 WORDS MOV START.(R3 > + START 1=START MOV RO,(R2 )• MOV START.(Rl ) + START2=START MOV 2(R3),(R2 ) + ;3. RATE MOV #1.(R2)+ ;4. NSCAN ;SET UP CLOCK INTERRUPT: ADD #6.R3 MOV #CKINT.CKPC MOV (R3)+.(R2)+ ;5. START CLR CKPS MOV (R3)+,(R2)+ ;6. NPOINT INCB FLAGO FLAGO=1 THE FIRST CYCLE MOV <R3).(R2) :7. STEP :SET COUNTING PROCESS MOV INF01,R4 ; INF01=ADDRESS OF INFO BLOCK OF SPECT1 MOV #3.CTCR COUNTING UP MODE CLRB FLAGO :LATER ON OUTPUT INF02. FLAGO USED AS FLAG MOV #T ABLE6,R2 ;CONVERT THESE TO ASCII CHARACTERS ;START SCANNING: TWICE: MOV #7 , R3 :R3 = PARAMETER COUNT MOV STKAD1.HEAD2 HEAD2 = HEAD OF SPECT2 BLANKS: MOV #64.,R1 :BLANK OUT THE INFO_TABLE(64 WORDS) ADD SIZEBY.HEAD2 MOV R4 , R5 BEGSCN: MOV STKAD1,R4 R4=P0INTER FOR SPECT 1 1$: MOV BLANK.(R5)+ MOV HEAD2.R3 R3=P0INTER FOR SPECT 2 SOB R1 , 1$ MOV NPOINT.PTCTR PTCTR=POINT COUNTER MOV RAMPST,RAMP RAMPST=1ST POINT OF RAMP 13$ : MOV #LIST2.R5 :CALL CHARAC MOV (R2)+,BINUM ;BINUM = BINARY NUMBER TO BE CONVERTED ;SCAN POINT BY POINT: JSR PC.CHARAC MOV #4.R0 :R0 = BYTE COUNT (4 BYTES FOR EACH) NEXTPT: CLR CTCR RESET COUNTER MOV #CHAR4.R1 12$ : CMPB #200.(R1) ;200 INDICATES END OF CHAR4 ;TRIGGER THE CLOCK PROCESS AND THE COUNTING PROCESS BNE 10$ MOV #14 1 .CKCR TURN ON THE CLOCK MOVB #40.(R4)+ ;PUT BLANKS UNTIL GOT 4 CHAR'S MOV #2.CTCR .TURN ON THE COUNTER BR 1 1$ TSTB FLAGO .IF FIRST TIME COME HERE. 10$ : MOVB (R1)*,(R4)+ BNE 3$ THEN GO TO CALL DISPLA 1 1$ : SOB RO.12$ ;CONVERTS AND STORES 4 DIGITS RT I ELSE RETURN TO INTERRUPTED POINT AT DISPLA MOV COMMA.(R4 ) + ;PUT A COMMA AND A BLANK AT THE END 3$: CLRB FLAGO ;FIRST CYCLE GO TO DISPLA MOV TABLE2.R5 SOB R3.13$ :REPEAT UNTIL 7 PARAMETERS ARE DONE JSR PC.DISPLA TSTB FLAGO :IF INF02 HAS BEEN UPDATED BNE TODISK : THEN OUTPUT INF0TABLE1 TO DISK MOV INF02.R4 ELSE DO THE SAME THINGS TO INF02 JSR PC,DISK MOV #TABLE6.R2 EXCEPT MOV #1.(R2) # SPECT = 1 ;PRINT MESSAGE OF HOW MANY SCANS HAVE BEEN OBTAINED: MOV NSCNOB.G(R2) # SCAN = NSCNOB(# OF SCANS OBTAINED) .PRINT #MSG1 :PRINT:('# OF SCANS OBTAINED IS : ' INCB FLAGO SET FLAG TO INDICATE IT'S SECOND TIME INC NSCNOB ;NSCNOB: # OF SCANS OBTAINED BR TWICE END_OF_IF MOV NSCNOB . 14 MOV #LIST1 . R5 ;OUTPUT INFORMATION BLOCK TO THE DUMP FILE ON DISK: JSR PC,IECHO :PRINT NSCNOB .PRINT #MSGO :PRINT (LINEFEED/RETURN) TODISK: MOV INF01,R4 OUTPUT INFO TABLE 1 TO DISK ADD #60.,R4 FIRST 60 BYTES ARE PARAMETERS ;CHECK IF GO OUT OR GO TO GET ANOTHER SCAN: MOV MSG0.(R4)+ NEXT 2 BYTES ARE LINE FEED AND RETURN MOV (SP1+.R5 ;RESTORE R5 TO THE INTERRUPTED POINT GTLIN R4.#MSG2 INPUT DESCRIPTION AS THE NEXT 64 BYTES MOVB #200,65.(R4) #200 AT THE END CMP NSCAN, NSCNOB :IF ALL REQUIRED SCANS ARE OVER BEO OUT ; THEN OUT MOV TABLE3.R5 OUTPUT TO DISK JSR PC.DISK TSTB F LAG 1 ;TEST FLAG . IF SET BY 'DISPLA' BNE OUT ; THEN OUT MOV INF02.R5 INITIALIZE THE DESCRIPTION OF SPECTRUM2 ; ELSE CONTINUE TO GET SCANS ADD #60.,R5 MOV (SP)*. RO :RESTORE RO MOV #33.,R3 MOVE THE 66 BYTES DESCRIPTION FIELD JMP BEGSCN ELSE GET ANOTHER SCAN MOV -2(R4),(R5>+ MOVE THE 60TH AND 61ST BYTES FIRST 1$: MOV (R4 )•.(RS) + THEN MOVE THE 66 BYTES DESCRIPTION OUT : MOVB #-1.F LAG 1 ;SET FLAG1 TO NEGATIVE TO STOP 'DISPLA' SOB R3 . 1$ MOV (SP)+. RO ;RESTORE RO MOV #100.P#KEYCR RTS PC RETURN TO MAIN RT I ;RETURN BACK TO THE INTERRUPTED 'DISPLA' CLOCK INTERRUPT HANDLER: ; DATA FIELD: t :KINT: MOV #17.CTCR ENABLE TO READ CTBR MOV CTBR.(R4) STORE COUNTS TABLE 1 .BLKW 1 ;LINK TO FIRST LIST OF PARAMETERS MOV #100,f#KEVCR ENABLE KEYBOARD INTERRUPT ;WHICH INCLUDES ALL THE SCANNING PARAMETERS BIC #170000,<R4) MOV 12 BIT COUNT TO SPECT1 ADD (R4)+.(R3)+ SPECT2 = SUM OF THE SCANNED DATA TABLE2 BLKW 1 ' LINK TO SECOND LIST OF PARAMETERS DEC PTCTR .WORD MODE BEO 4$ ONE SCAN IS OVER .WORD STACK 1 SUB STEP,RAMP STEP DOWN THE RAMP .WORD SPECT1 CLR »#KEYCR DISABLE KEYBOARD INTERRUPT WORD SPECT2 JMP NEXTPT AND GET MORE POINTS .WORD SPECT3 WORD SPECT4 ONE SCAN IS OVER, STORE THE PREVIOUS SCAN AND PREPARE FOR OTHER SCANS: WORD FLAG STORE: TABLE3 .BLKW 1 LINK TO THIRD LIST OF PARAMETERS (HOW TO CALL DISK) 4$ : MOV RO.-(SP) SAVE R0.R5 MOV R5.-(SP) MOV TABLES,R5 R5 POINTS PARAMETER LIST FOR 'DISK' TABLE4 .BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECTRUM 1: MOV R5.R4 SPECT1: .BLKW 1 ADD #4,R4 BEGIN 1 : BLKW 1 TST NSCNOB IF 1ST TRANSFER NPT1: .BLKW 1 BEO 5$ THEN START_BLOCK=1 STEP 1: BLKW 1 MOV SIZEWD.RO SIZWD1: .BLKW 1 ASH #-8.,RO UPDATE STARTING BLOCK # OF THIS TRANSFER INF01: BLKW 1 ADD RO,(R4)+ SCALE 1: .BLKW 1 BR 6% SEPER1: BLKW 1 5$: MOV # 1 .<R4) + START BLOCK # IS ONE AT THE BEGINNING HEAD 1 : BLKW 1 6»: MOV STKAD1,(R4)+ STORE SPECT1 START 1: BLKW 1 (SEE THE MAIN PROGRAM) MOV SIZEWD,(R4)• STORE SPECT1 BISB #1 .(R4 ) SET THE WR MODE TABLE5 .BLKW 1 ADDRESS OF PSECTRUM STATUS TABLE OF SPECTRUM 2 TABLES: .BLKW 7 TEMP STORGE FOR 7 BINARY NUMBERS RAMPST: PTCTR: BLKW BLKW J STARTING POINT OF RAMP POINT COUNTER NSCAN: START: NPOINT: STEP: BLKW BLKW .BLKW .BLKW J NUMBER OF SCAN REQUIRED START POINT* NUMBER OF POINTS TO BE SCANNED STEP SIZE SIZEBV: SIZEWD: BLKW BLKW ; SIZE OF MEMORY IN BYTES SIZE OF MEMORY IN WORDS FLAGO: FLAG1: . BYTE .BYTE EVEN 0 O FLAG 0 IS USED TO DETERMINE SOME CONDITIONS FLAG t IS USED TO COMMUNICATE WITH 'DISPLA' STKAD1: HEAD2: INF01: INF02: INTRAD: BLKW BLKW .BLKW .BLKW BLKW 1 1 1 1 1 ADDRESS OF STACK 1 HEAD OF SPECT2 ADDRESS OF INFO TABLE OF SPECT1 ADDRESS OF INFO TABLE OF SPECT2 ADDRESS OF KEYBOARD INTERRUPT HANDLER NSCNOB: .WORD 0 NUMBER OF SCAN OBTAINED LI ST 1 : 14 : .WORD BLKW 1 ;CALL IECHO TO ECHO AN 14 NUMBER 1 LIST2: BINUM: .WORD .BLKW WORD 2 1 CHAR4 ;CALL BINARY ;B1NARY * CHAR4: COMMA: BLANK: . ETLKW ASCII ASCII 3 /. / / / ;CHAR4 SHOULD HAVE MSGO: ASCII <12><15><200> MSG 1 : ASCII / * OF SCANS OBTAINED IS: /<200> MSG2 : ASCII EVEN /TYPE IN DESCRIPTION: /<200> ;END OF SUBROUTINE SCAN . END C O I o INPUT: MOV #LIST2 R5 * •**'* * * . * . *.*...**. JSR PC.EXTRAC ;GET NEW VALUE SUBROUTINE SEPERA VERSION . 1 1-MAR-81 MOV #ARGU1 ASCIAD CMPB #'-.ARGU1 ;IF NEGATIVE .«*..*...***.. •**.***,***. . • . * * **...******........*...*......*..... ****•,,•. BNE 1$ FUNCTION OF THIS SUBROUTINE IS TO CHANGE THE SEPARATION BETWEEN A SPECTRUM INC ASCIAD ; THEN SKIP THE SIGN BYTE AND THE BASE LINE. 1$ : CMPB #200.ARGU1 ;IF NO INPUT-BEO NEXT ; THEN DON'T CHANGE THIS SPECTRUM THE PARAMETER LIST PASSED TO THIS SUBROUTINE IS: MOV #LIST3.R5 :CONVERT VALUE TO BINARY LIST: WORD 10. CALL A DATA MANIPULATING SUBROUTINE JSR PC.BINARY SAVE : .BLKW 1 ADDRESS OF PARAMETER LIST TO CALL 'DISPLA' (JUST USED FOR FURTHER MODIFICATION) ;UPOATE THE STATUS TABLE AND MOVE THE SPECTRUM VERTICALLY TO NEW POSITION: XCUR : . WORD 4095 . X COORDINATE OF THE CURSOR OPERAT: MOV NEWVAL 1S(R4) :UPDATE SEPER N YCUR : WORD 0 Y COORDINATE OF THE CURSOR SUB 14.NEWVAL :NEWVAL =NEWVAL-OLDVAL FACTOR .WORD O SCALE FACTOR USED FOR DISPLAY SUM OF SCANS MODE : BLKW 1 THE DISPLAY MODE MOV 201R4) R1 ;R1=P0INTER . SPTAD1 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT 1 MOV 10(R4) R2 :R2># OF POINTS IN THE WHOLE SPECTRUM SPTAD2 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT2 MOV NEWVAL R4 :R4=VERTICAL POSITION TO BE CHANGED SPTAD3 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT3 SPTAD4 BLKW 1 ADDRESS OF SPECTRUM STATUS TABLE OF SPECT4 i$ : ADD R4. (R1 )* :MOVE THE SPECT_N VERTICALLY STKAD1 .BLKW 1 ADDRESS OF STACK 1 USED TO STORE THE SPECTRA SOB R2. 1$ *..******.*.*. *.».****•.•**.*».**.*•******•**•**••»•*...****••«*•*** ......... :CHECK THE NEXT ONE : TITLE SEPARATION SPECT AND BASELINE NEXT : INC N .GLOBL SEPERA,EXTRAC. IECHO.BINARY ASLB MODTST :CHECK NEXT SPECTRUM .MCALL .PRINT CMP N. #4 ;UNTIL N>4 M0DE=#10 WHEN N=4 BLE LOOP SEPERA: ADD #12.R5 MOV (R5I+.M0DE MODE = THE DISPLAY MODE :JOB DONE: MOV R5,TABLSP ;TABLSP POINTS TO POINTERS OF STATUS TABLES FINISH: .PRINT #MSG5 ;PRINT 'COMMAND 'SEPERA' FINISHED.' ;CHECK IF THE SPECTRUM IS BEING DISPLAYED: RTS PC :RETURN MOVB #1.MODTST MOV # 1 . N IF SPECTN IS NOT BEING DISPLAYED LOOP : BITB MODTST,MODE BEO NEXT THEN CHECK NEXT ONE :DATA FIELD: ELSE OUTPUT OLD SEPERATION. INPUT NEW ONE MODE : . BLKW 1 ;THE DISPLAY MODE :OUTPUT OLD SEPERATION: OUTPUT: PRINT #MSG1 ;PRINT ('SPECTRUM ') TABLSP: . BLKW 1 ;TABLSP POINTS TO THE POINTERS OF THE MOV N. 14 ; SPECTRUM STATUS TABLES MOV #LIST1,R5 JSR PC. I ECHO ;PRINT N .PRINT #MSG2 PRINT (' IS POSITIONED AT ') LI ST 1 : . WORD 1 ;CALL IECHO TO ECHO AN 14 NUMBER 14 : .BLKW 1 MOV N.R4 DEC R4 ASL R4 R4 = OFFSET FROM #SPTAD N TO #SPTAD 1 LIST2: . WORD 2 ;CALL EXTRAC TO INPUT THE NEW VALUE ADD TABLSP.R4 R4 POINTS TO POINTER TO SPECTRUM STATUS TABLE . WORD MSG4 MOV (R4),R4 R4 POINTS TO THE SPECTRUM STATUS TABLE . WORD ARGU 1 M