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Preparation, magnetic and spectral properties of some monoaniline and monopyridine adducts of substituted… Landa , Benjamin 1969

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PREPARATION, MAGNETIC AND SPECTRAL PROPERTIES OF SOME MONOANILINE AND MONOPYRIDINE ADDUCTS OF SUBSTITUTED ARYLCARBOXYIATES OF COPPER(II) by BENJAMIN LANDA B . S c , U n i v e r s i t y of B r i t i s h Columbia 1965 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n the Department of Chemistry THE UNIVERSITY OF BRITISH COLUMBIA A p r i l 1969 In 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 the 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 olumbia, I a g r e e t h a t the 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 Study. I f u r t h e r a g r e e 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 of t h i s t h e s i s f o r s c h o l a r l y purposes may be g r a n t e d by the Head o f my Department o r by h i s 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 thes,is f o r f i n a n c i a l g a i n s h a l l not 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 . The U n i v e r s i t y o f B r i t i s h Columb Vancouver 8, Canada Department ABSTRACT Monoanil ine and monopyridine adducts of copper (II) or tho-m e t h y l - , meta-methyl- , ortho-bromo-, and meta-bromobenzoate, and mono-a n i l i n e adducts of copper (II) o r t h o - c h l o r o - , p a r a - m e t h y l - , and p a r a -bromobenzoate were prepared. Magnetic s u s c e p t i b i l i t y measurements of these compounds were made at room temperature on Gouy and Faraday apparatus. V a r i a b l e temperature s u s c e p t i b i l i t y measurements over the range 77 - 330°K were made employing a Gouy apparatus. V i s i b l e d i f f u s e re f l ec tance s p e c t r a as w e l l as s o l u t i o n spec tra of these compounds were a l so recorded. Molecular weight measurements could be obtained only for a few of the compounds because of t h e i r marked i n s o l u b i l i t y . S truc ture and bonding are discussed i n the l i g h t of the r e s u l t s . i i TABLE OF CONTENTS Page ABSTRACT ± TABLE OF CONTENTS ± ± LIST OF TABLES i v LIST OF FIGURES v ACKNOWLEDGEMENT v i i CHAPTER I INTRODUCTION 1 1.1. Previous s tudies on copper (II) carboxylates 1 1.2. Purpose of the present work 12 CHAPTER II EXPERIMENTAL 13 2.1. P u r i f i c a t i o n of mater ia l s 13 2.2. Prepara t ion of copper (II) complex 13 2.2.1. Copper (II ) a r y l c a r b o x y l a t e s 13 2.2.2. P y r i d i n e adducts 14 2.2.3. A n i l i n e adducts 15 2.3. Analyses 18 2.4. S o l u b i l i t y tests 19 2.5. Magnetic s u s c e p t i b i l i t y measurements 19 2.5.1. Gouy method 2.5.2. Faraday method 20 2.6. E l e c t r o n i c Spectra 20 2.7. Molecular weights 21 i i i Page CHAPTER I I I RESULTS 23 3.1. Magnetic s u s c e p t i b i l i t y s tudies 23 3.2. E l e c t r o n i c spectra 44 3.3. Molecular weight determinations 45 3.4. S o l u b i l i t y tests 53 CHAPTER IV 4.1. S tructure and bonding ' 54 4.2. Concerning the ease of formation of the monoamine adducts 60 . 4.3. S i g n i f i c a n c e of g values as determined from magnetic s u s c e p t i b i l i t y s tudies 61 4.4. Conclusions 65 4.5. Suggestions f o r f u r t h e r work 66 BIBLIOGRAPHY 67 APPENDIX 69 iv L I S T OF TABLES TABLE Page I COPPER ( I I ) CARBOXYLASES 3 I I ANALYTICAL RESULTS 17 I I I MOLECULAR WEIGHT DATA 22 IV EXPERIMENTAL AND CALCULATED GRAM AND MOLAR SUSCEPTIBILITIES 2 4 V ROOM TEMPERATURE MAGNETIC SUSCEPTIBILITY DATA 29 V I ADDITIONAL MAGNETIC DATA FOR THE BINUCLEAR COMPOUNDS 3 0 V I I . MAGNETIC MOMENTS IN ANILINE SOLUTION AND OF THE POWDERED SAMPLE 42 V I I I POSITION OF BAND MAXIMA (OR SHOULDERS) IN SOLUTIONS AND IN DIFFUSE REFLECTANCE 4 3 LIST OF FIGURES FIGURE 1 2 3 4 10 11 12 13 14 15 16 STRUCTURE OF THE CUPRIC ACETATE MONOHYDRATE MOLECULE CARB0XY1ATE BONDING CONFIGURATIONS CRYOMAGNETIC DATA FOR COPPER (II) BENZOATE ANILINE CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-METHYL-BENZOATE PYRIDINE CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-METHYL-BE NZOATE ANILINE DIFFUSE REFLECTANCE AND SOLUTION SPECTRA OF MONO-ANILINE AND MONOPYRIDINE ADDUCTS OF COPPER (IT) ARYLCARBOXYLATE S DIFFUSE REFLECTANCE AND SOLUTION SPECTRA OF MONOANILINE AND MONOPYRIDINE ADDUCTS OF COPPER (II) ARYCARB OXYLATE S PAGE 7 10 31 32 33 CRYOMAGNETIC DATA FOR COPPER (II) META-METHYL-BENZOATE PYRIDINE 34 CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-BROMOBENZOATE PYRIDINE 35 CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-BROMOBENZOATE ANILINE 36 CRYOMAGNETIC DATA FOR COPPER (II) META-BROMOBENZOATE PYRIDINE 37 CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-CHLOROBENZOATE ANILINE 38 CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-BROMOBENZOATE 39 CRYOMAGNETIC DATA FOR COPPER (II) META-BROMO, META-METHYL, PARA-METHYL, AND PARABROMOBENZOATE ANILINE 40 DIFFUSE REFLECTANCE SPECTRA OF MONOANILINE ADDUCTS OF COPPER (II) ARYLCARBOXYLATES 41 DIFFUSE REFLECTANCE AND SOLUTION SPECTRA OF MONO-ANILINE AND MONOPYRIDINE ADDUCTS OF COPPER (II) ARYLCARBOXYLATES 46 47 48 v i FIGURES (Continued) FIGURE • PAGE 17 VISIBLE SPECTRA IN ANILINE OF COPPER (II) FORMATE TETRAHYDRATE AND COPPER (II) ORTHO-METHYL BENZOATE ANILINE 49 18 VISIBLE SPECTRA IN ANILINE OF MONOANILINE ADDUCTS OF COPPER (II) ARYLCARBOXYLATES 50 19 ULTRA VIOLET SPECTRA IN DICHLOROMETHANE OF THE MONOANILINE AND MONOPYRIDINE ADDUCTS OF COPPER (II) vMETA-METHYLBENZOATE 51 20 PROPOSED STRUCTURE FOR THE MONO ANILINE ADDUCTS OF THE COPPER (II) META AND PARA-SUBSTITUTED ARYLCARBOXYLATES 52 21 CRYOMAGNETIC DATA FOR COPPER (II) META-BROMOBENZOATE PYRIDINE WITH AND WITHOUT PARAMAGNETIC IMPURITY 55 22 CRYOMAGNETIC DATA FOR COPPER (II) ORTHO-METHYLBENZOATE PYRIDINE WITH AND WITHOUT PARAMAGNETIC IMPURITY 56 23 VARIATION OF ERROR WITH g FOR COPPER (II) ORTHO-CHLOROBENZOATE ANILINE 62 v i i ACKNOWLEDGEMENTS The author wishes to express h i s gra t i tude to Dr. R . C . Thompson, h i s research superv i sor , who f i r s t suggested the problem, for h i s pa t i en t and c a r e f u l guidance, and for h i s s t imula t ing d i s c u s s i o n of the work. The author a l so wishes to express h i s gra t i tude to Mr. K.N.Shaw who wrote the computer programme and to Mr. P. Borda who performed the carbon, hydrogen and ritrogen analyses . . CHAPTER 1 I . I INTRODUCTION 1..1 Previous s tudies on copper ( II ) carboxylates 9 M a g n e t i c a l l y d i l u t e copper ( II ) compounds (d e l e c t r o n i c systems) i n an oc tahedra l e l e c t r o n i c environment obey Cur ie law and have magnetic moments i n the range 1.8 - . 2 . 1 Bohr Magnetons (B .M.) The experimental room temperature moments are somewhat h igher than those c a l c u l a t e d from the "sp in-only" formula (1) (2) (3): y*t so = V r 4 S ( S + l ) (1) which for one unpaired e l e c t r o n i s 1.73 B . M . Thi s i s a r e s u l t of c o n t r i b u -2 t i o n of o r b i t a l angular momentum a r i s i n g from a higher l y i n g T^ term with 2 9 the ground term that i s present i n an oc tahedra l d c o n f i g u r a t i o n . T h i s "mixing" can be descr ibed by equation (2) /H e f f = ./i so (1 - o< > / l 0 Dq) (2) where ? V i s the s p i n - o r b i t coupl ing constant and lOD^j the separat ion between the two terms. 7^ i s ^ 0 for l e s s than h a l f - f i l l e d s h e l l s and ^ 0 f o r more than h a l f - f i l l e d s h e l l s . The -</^L0D^ term descr ibes 2 the degree of p e r t u r b a t i o n of the ground s tate ( E^) when o r b i t a l angular 2 momentum from the higher l y i n g 1^ term i s in t roduced . I t i s obtained upon a p p l i c a t i o n of the s p i n - o r b i t coupl ing operator on the wave funct ions of A and E terms. The p e r t u r b a t i o n f o r the g va lue i s then obtained i n s i m i l a r form as equat ion (2): 2 g = 2 (1 - aX/lODq) (3) where the constant a i s 2 or 4 when e i t h e r A or E terms are i n t e r a c t i n g wi th T terms. A l a r g e c lass of copper (II). compounds, however do not obey s imple C u r i e , or Curie-Weiss law. The copper (II) carboxylates have aroused cons iderable i n t e r e s t because of t h e i r unusual magnetic proper t i e s (4). (Table 1). Table 1 summarizes the magnetic p r o p e r t i e s of the complexes s t u d i e d . Some of the compounds are charac ter i zed by unusual ly low room-temperature moments (u e f f ~ 1.40 B.M.) and t h e i r s u s c e p t i b i l i t y (X^) -temperature (T) curves show broad maxima. Thi s ant i ferromagnet ic behavior i s a r e s u l t of d e f i n i t e s t r u c t u r a l features of these compounds. In an X-ray s tudy, Niekerk and Schoening found copper (II) acetate monohydrate to have a d imeric s t r u c t u r e ( F i g . 1). The two copper atoms are i n c lose prox imity to each other (copper-copper separat ion of O 2.64 A) and are br idged to each other by four carboxylate groups. The two water molecules each occupy termina l p o s i t i o n s on the copper atoms. In t h i s compound there i s a l a t e r a l overlap of d ^ v2 o r D i t ' a l s of the two copper atoms r e s u l t i n g i n the formation of a (5 bond (6, 42). The a n t i f e r r o -magnetic i n t e r a c t i o n has been expla ined as a r i s i n g through the i n t e r a c t i o n of the two paramagnetic centers to form a "singlet ground e l e c t r o n i c s ta te and upper t r i p l e t e l e c t r o n i c s t a t e . The i n t e r a c t i o n i s in t ramolecu lar as the exchange occurs w i t h i n the molecule . The p o s s i b i l i t y that bond formation occurs v i a the d £ o r b i t a l s was re jec ted on the grounds that the promotional energy needed to a t t a i n t h i s i s too large (12,000 cm ^ ) (6). For copper (II) 3 TABLE 1 COPPER (II) CARBOXYLATES Compound p e f f . ( B - M , ) (rocm temp) Reference Cu ( I I ) formate ( r o y a l b lue) 1.90 9 ti 2H 2 0 1.90 9 I I turquoise 1.75 9 I I 4H 0 1.75 9 I I H COOH 1.64 9 I I blue 1.61 9 I I (NH ) CO 1.08 4 I I 2(NH j 2H 0 1.67 4 it 1 a n i l i n e 1.85 18 I I ^ - p y r i d i n e 1.07 18 I I ^ - p i c o l i n e 1.06 18 I I i f - p i c o l i n e 1.10 18 t i p i c o l i n e 1.06 18 I I % dioxane 0.96 18 Cu ( II ) acetate 1.39 6 I I H 2 ° 1.40 6 I I i & p y r i d i n e 1.35 10 I I ^ • p i c o l i n e 1.34 10 I I ^ . p i c o l i n e 1.36 10 it p i c o l i n e 1.36 10 I I (NH 2 ) 2 C0 1.37 4 ft (NH ) 2 C 0 H 2 0 1.37 4 ti a n i l i n e 1.73 10 I I p - t o l u i d i n e 1.78 10 n 2 p - t o l u i d i n e 1.84 10 I I dioxane 1.30 18 ti % dioxane 1.38 18 Cu ( I I ) butyrate 1.37 10 I I H 2 ° 1.35 10 I I o ( » p y r i d i n e 1.34 10 I I /$• p i c o l i n e 1.32 10 I I ^ - p i c o l i n e 1.34 10 I I a n i l i n e 1.73 10 ti m-to lu id ine 1.73 10 I I p - t o l u i d i n e 1.76 10 ti urea 1.42 4 Cu ( I I ) v a l e r a t e 1.41 17 I I % urea 1.43 4 Copper (II ) caproate 1.40 4 I I % urea 1.40 4 TABLE 1 (Continued) Compound ^ e f f . ( B - M - ) Reference r (room temp) -Copper (II) enanthoate 1.42 4 " % urea 1.42 4 Copper (II) c a p r i l i c o a t e 1.40 4 " % urea 1.42 4 Copper (II) pelargonoate 1.42 4 ••" h urea 1.39 4 Copper (II ) undecanoate 1.45 4 Copper (II) Laurate 1.40 4 Copper (II ) laurate p y r i d i n e 1.48 4 Copper ( I I ) myr i s ta te 1.43 4 Copper (II) palmitate 1.45 4 Copper (II ) behenoate 1.40 4 Copper (II) ch loroaceta te 1.42 4 4H 2 0 1.45 4 Copper (II ) d i c h l o r o a c e t a t e 1.66 4 " 4H 20 1.74 4 Copper (II) t r i c h l o r o a c e t a t e 1.77 4 " 3H 2 0 1.77 4 Copper (II ) monobromoacetate 1.5 4 Copper (II ) t r i f l u o r o a c e t a t e 1.9 20 Copper ( II ) phenylacetate 1.44 4 Copper (II) d iphenylacetate 1.38 4 Copper (II ) Naphtylacetate 1.44 4 Copper (II ) oxalate 1.20 19 " %H20 1.25 19 Copper (II ) malonate 1.75 19 " %H20 1.77 19 Copper (II ) succ inate 1.30 19 " 2IL0 1.34 19 1 1 p y r i d i n e • 1.54 19 " a n i l i n e 1.60 19 Copper (II) g l u t a r a t e 1.34 19 " p y r i d i n e 1.34 19 " a n i l i n e 1.73 19 Copper (II ) adipate 1.20 19 " p y r i d i n e 1.40 19 TABLE 1 (Continued) i t t i I I t i t i t i t i i i t i . - y (B.M.) Compound , e t t ' , ^ Reference r (room temp) • Copper (II) benzoate 1.78 ) 11 1.53 ) 11 1.45 ) 11 1.40 ) 11 1.72 . 12 A.49 12 1.40 12 3H 0 1.87 12 EtOH 1.43 11 benzoic acid 1.42 11 % (4.4-bipyridil) 1.42 11 pyridine 1.42 11 Copper (II) o-bromobenzoate 1.63 41 Copper (II) o-bromobenzoate pyridine 1.37 41 Copper (II) m-bromobenzoate 1.74 4 Copper (II) p-bromobenzoate 1.58 4 Copper (II) o-chlorobenzoate 1.45 8 . . " • ^0 1.51 8 " pyridine 1.32 8 Copper (II) m-chlorobenzoate A 1.73 8 B 1.37 8 2H20 1.91 8 11 pyridine 1.82 7 0.8 pyridine 1.43 7 % pyridine 1.46 7 1.69 7 Copper (II) p-chlorobenzoate 2 pyridine 1.82 7 " 1.2 pyridine 1.50 7 I I t t I I I I t i t i i i t i t t 0.8 pyridine 1.46 7 % pyridine 1.53 7 p-chlorobenzoate 1.46 7 Copper (II) o-methylbenzoate 1.41 8 Copper (II) m-methylbenzoate A 1.42 8 ." B 1.69 8 Copper (II) p-methylbanzoate 1.36 8 H20 • 2.06 8 Copper (II) o-tiitrobenzoate > 1.45 8 " *~ H 0 A 1.86 8 " HT0 B 1.34 8 " pyridine 1.39 41 Copper (II) m-nitrobenzoate 1.67 8 " 2H20 1.84 8 6 TABLE 1 (Continued) Compound ^ e f f . ^ - M - { Reference r (room temp)  Copper (IT) benzoate butanol 1«46 29 Copper (II) p-methylbenzoate butanol 1„40 29 Copper (II) p-nitrobenzoate butanol 1D45 29 Copper (II) p-methoxybenzoate butanol 1.47 29 Copper (II) p-bromobenzoate butanol 1.45 29 Copper (II) p-chlorobenzoate ethanol 1.50 23 Copper (II) p-bromobenzoate ethanol 1051 ' 23 Copper (II) p-iodobenzoate ethanol 1„48 23 St ruc tu re of the c u p r i c ace ta te monohydra t e molecu le z Figure 1 acetate monohydrate and a number of the higher copper (II) alkanoates the magnetic s u s c e p t i b i l i t y data was s u c c e s s f u l l y f i t t e d to the express ion: Xm = g 2**/^ 2 ' ( 1 + 1/3 exp 2J /kT + N a (4) kT s where g i s the Lande spectroscopic s p l i t t i n g f a c t o r N , Avogadros's number B, the Bohr magneton k, the Boltzman constant J, the exchange coupl ing constant and N a i s the temperature-independent paramagnetic c o n t r i b u t i o n to the molar s u s c e p t i b i l i t y of copper ( I I ) . Some authors , however, have experienc poor agreement between experimental and t h e o r e t i c a l curves c a l c u l a t e d from equat ion (4 ) . A t low temperature the experimental values were found to be h igher than the t h e o r e t i c a l v a l u e s . Thompson e t . a l . found be t t er agree-ment with theory by a l lowing for a small percentage of magnet i ca l ly d i l u t e i m p u r i t i e s for copper ( II ) benzoate. (36) A number of copper (II ) carboxy la te s , however, d i s p l a y weaker magnetic i n t e r a c t i o n than the b i n u c l e a r carboxy la te s . These inc lude f o r example copper (IT) formate t e t rahydrate , (9) copper (II) acetate monoanil ine copper (II ) butyrate monoanil ine (10) and some forms of copper ( I I ) benzoate (11) (12) (13). Kokot and M a r t i n proposed that the weaker magnetic i n t e r a c t i o n i s a r e s u l t of a d i f f e r e n t s t r u c t u r a l arrange-ment found i n these compounds (10). They c l a s s i f i e d the b r i d g i n g arrange-ment between the copper atoms of the b i n u c l e a r compounds as exempl i f ied by copper ( II ) acetate monohydrate as a syn-syn arrangement and the b r i d g i n g arrangement i n the others as being e i t h e r an a n t i - a n t i or an a n t i - s y n as i shown i n F i g u r e 2. X - r a y s tudies have confirmed the presence of polymeric a n t i -a n t i , and a n t i - s y n arrangements o c c u r r i n g r e s p e c t i v e l y for copper (II ) formate te trahydrate (14) and the r o y a l - b l u e form of anhydrous copper (II ) formate (15). In the polymeric s t ruc ture the copper-copper d is tance i s greater than i n the b i n u c l e a r model being of the order 5.80A and 3.44A i n the copper (II) formate t e t r a h y d r a t e , and r o y a l - b l u e form of anhydrous copper (II ) formate r e s p e c t i v e l y . Copper ( II ) benzoate t r i h y d r a t e has a l so been shown to have a polymeric s t r u c t u r e (16). M a r t i n e t . a l . have suggested that the tendency f o r a compound to adopt a b i n u c l e a r s t ruc ture w i l l be governed by the amount of r e s i d u a l charge remaining on the copper atoms. The pKa of the parent a c i d can be taken as a measure of the degree of p o l a r i z a b i l i t y of the carboxylate a n i o n . (17) (9). Since anions der ived from ac ids wi th h igh pKa's w i l l be more p o l a r i z a b l e than those der ived from ac ids having lower pKa's they w i l l reduce the unfavorable accumulation of p o s i t i v e charge on the copper atoms and thereby s t a b i l i z e the b i n u c l e a r c o n f i g u r a t i o n more e f f e c t i v e -l y . T h i s ho lds true f o r the copper (II ) alkanoates i n which the parent a c i d ... has pKa's ^ a c e t i c ac id (pKa = 4.75). In the copper ( II ) formates i n which the pKa of the parent a c i d i s 3.55, the b i n u c l e a r s t ruc ture i s d e s t a b i l i z e d and they adopt a polymeric s t r u c t u r e ; apparent ly the pKa of the parent a c i d i s too low and thus a c r i t i c a l accumulation of p o s i t i v e charge d e s t a b i l i z e s the b i n u c l e a r s t r u c t u r e . M a r t i n and Waterman have found that s u b s t i t u t i o n of s t rong ly e l ec tron-donat ing l igands such as p y r i d i n e or dicrcane to polymeric copper ( II ) formates markedly reduces the 10 O — C u R C R \ O — C u (a) Carboxylate bonding configurations: (a ) syn — syn (b ) anti — anti ( c ) anti - syn Figure 2 11 r e s i d u a l charge on the copper atoms and i n fac t "condit ions" the polymeric s t r u c t u r e i n t o the b i n u c l e a r u n i t . P y r i d i n e coord inat ion to compounds that are b i n u c l e a r such as copper (II) acetate i t s e l f however, does not s i g n i -f i c a n t l y increase the magnetic i n t e r a c t i o n (18). I t was found, on the other hand, that a n i l i n e s u b s t i t u t i o n on a s e r i e s of b i n u c l e a r copper (II) alkanoates reduces the i n t e r a c t i o n cons iderab ly . M a r t i n e t . a l . a l so demonstrated t h i s behavior for monoaniline and monopyridine adducts of copper (II) C6,u d i carboxy la tes (19). P y r i d i n e coord ina t ion d i d not modify the magnetic i n t e r a c t i o n s i g n i f i c a n t l y from the anhydrous b i n u c l e a r copper (II) a,oj d i c a r b o x y l a t e but a n i l i n e coord inat ion decreased the magnetic i n t e r -a c t i o n c o n s i d e r a b l y . Thompson and Yawney fur ther demonstrated the s i g n i -f i cance of the pKa of the parent a c i d i n i n f l u e n c i n g s t r u c t u r e by forming magnet i ca l ly d i l u t e copper (II) t r i f l u o r o a c e t a t e (20). As would be expected the t r i f l u o r o a c e t a t e anion leaves a l a r g e amount of r e s i d u a l p o s i t i v e charge on the copper atoms-thus rendering the b i n u c l e a r s t r u c t u r e unstable . On pass ing to the copper (II) a r y l c a r b o x y l a t e s , the c r i t e r i a of pKa that was used i n p r e d i c t i n g s t r u c t u r a l arrangements i n the a l k y l copper (II) carboxylates does not apply. (8, 21, 22). I t appears on the b a s i s of magnetic evidence that even when the pKa of the parent a c i d i s w e l l below that of formic a c i d , the copper (II) s a l t s of o r t h o - s u b s t i t u t e d a r y l c a r b o x y l a t e s , (such as o r t h o - n i t r o - , . o r t h o - c h l o r o - , and ortho-bromo-benzoate) possess the b i n u c l e a r s t r u c t u r e . A number of other copper (II) a r y l carboxylates were prepared i n more than one magnet ica l ly d i s t i n c t form. The presence of magnet ica l ly d i s t i n c t compounds fur ther com-p l i c a t e s the a n a l y s i s of t h e i r magnetic behav ior . Another compl icat ion 12 was found by L i n and Thompson who had d i f f i c u l t y i n prepar ing s t o i c h i o -metr ic imnopyridine adducts of copper (II) meta- and para-chlorobenzoates (7) . In a study of butano l and ethanol adducts of some p a r a -s u b s t i t u t e d copper (II) ary lcarboxy la te s H a t f i e l d e t . a l . found the magnetic proper t i e s of t h e i r compounds to be r e l a t i v e l y i n s e n s i t i v e to the nature of the subs t i tuent on the phenyl r i n g (13). 1.2 Purpose of the present work In view of the a b i l i t y of p y r i d i n e to cond i t ion copper (II) formate i n t o a b i n u c l e a r s t r u c t u r e i t was of i n t e r e s t to attempt to prepare a s e r i e s of monopyridine adducts of s u b s t i t u t e d copper (II) ary l carboxy la te s i n order to see i f the degree of magnetic i n t e r a c t i o n i n these compounds could be c o r r e l a t e d wi th the nature and p o s i t i o n of the subs t i tuent on the benzene r i n g . Moreover, the observat ion by M a r t i n of the apparent decrease i n the degree of magnetic i n t e r a c t i o n when the terminal l i g a n d i s a n i l i n e prompted a study of monoaniline adducts of these s u b s t i t u t e d carboxy la tes . 13 CHAPTER I I | EXPERIMENTAL 2.1 P u r i f i c a t i o n of mater ia l s The appropriate "Eastman Kodak" reagent grade ary1carboxyl ie ac ids were used d i r e c t l y without p u r i f i c a t i o n . "Eastman Kodak" reagent grade a n i l i n e and p y r i d i n e were each, d r i e d over potassium hydroxide and then d i s t i l l e d and s tored away from l i g h t . Reagent grade benzene was d i s t i l l e d from sodium before use. "Fisher" reagent grade dichloromethane was used d i r e c t l y without f u r t h e r p u r i f i c a t i o n . Reagent grade carbon t e t r a c h l o r i d e and chloroform were used d i r e c t l y without fur ther p u r i f i c a -t i o n . 2.2 P r e p a r a t i o n of copper (II) complexes 2.2.1 Copper (II) ary l carboxy la te s A l l the copper (II) ary l carboxy la te s s tud ied i n t h i s work were prepared by the same general method descr ibed below. To a s t i r r i n g suspension of the appropriate a r y l c a r b o x y l i c a c i d was added a 10% sodium hydroxide s o l u t i o n . The undisso lved a c i d was then removed by f i l t r a t i o n . The pH of the r e s u l t i n g s o l u t i o n was always 5.5 or l e s s . When a s l i g h t excess copper sulphate pentahydrate was added i n the form of a saturated s o l u t i o n , an.immediate b lue p r e c i p i t a t e formed. The p r e c i p i t a t e was f i l t e r e d and washed repeatedly wi th d i s t i l l e d water u n t i l free of sulphate (BaCl - test) . . 14 The product was then d r i e d under vacuum (10 mm Hg) over phosphoric oxide at the temperature of b o i l i n g t e t r a d ; l o r oe thy lene for 3-4 hours . Copper (II ) ortho-bromobenzoate monohydrate Thi s compound was prepared i n the manner descr ibed above only a d i l u t e copper sulphate s o l u t i o n was used. Upon adding the copper sulphate s o l u t i o n to sodium ortho-bromobenzoate, a b lue-green s o l u t i o n formed and upon standing f o r one hour green c r y s t a l s formed. The c r y s t a l s were then washed free of sulphate and d r i e d i n a vacuum dess i ca tor over phosphoric ox ide . 2 . 2 . 2 . P y r i d i n e adducts The anhydrous copper (II) a r y l c a r b o x y l a t e was simply d i s s o l v e d i n a minimum quant i ty of warm pyr id ine whereupon a purple s o l u t i o n immediately formed. Upon standing over concentrated su lphur ic a c i d i n a vacuum d e s s i c a t o r f o r approximately one to three weeks, a purple s o l i d formed which g r a d u a l l y changed into a l i g h t - g r e e n s o l i d . Copper (II) ortho-bromo-benzoate monopyridine, copper (II) meta-bromobenzoate monopyridine copper (II) ortho-methylbenzoate monopyridine, and copper (II) meta-methylbenzoate mono-p y r i d i n e were made i n th i s manner. Copper (II) para-ni trobenzoate b i s p y r i d i n e The above procedure y i e l d e d copper (II) para-nitrobenzoate b i s p y r i d i n e . Attempts to remove one mole of p y r i d i n e to make the monopyridine adduct by heat ing over phosphoric oxide at the temperature of b o i l i n g t e t r a c h l o r o e t h y l e n e under vacuum (10 mm Hg) were unsuccess fu l . I t was observed that upon hea t ing , the c o l o r of the compound changed from purple to b l u e . 15 2 . 2 . 3 . A n i l i n e adducts Copper ( II ) benzoate monoaniline To a s t i r r i n g mixture of 20 ml a n i l i n e (0.213 moles) i n 80 ml benzene was added 0.01 moles of copper (II) benzoate; a green s o l u t i o n immediately formed. Later a green p r e c i p i t a t e s e t t l e d out . Th i s was f i l t e r e d and washed s evera l times wi th petroleum ether ( b p - 3 0 - 6 0 ° ) . The green substance which was shown by a n a l y s i s to conta in more than 1 mole of a n i l i n e per mole of copper was then heated over phosphoric oxide (^Of,) a t the temperature of b o i l i n g t e trach lore thy lene under vacuum (10 mm Hg) f o r one hour . Copper (II) ortho-methylbenzoate monoaniline To a s t i r r i n g mixture of 20 ml a n i l i n e (0.213 moles) i n 80 ml benzene was added 0.015 moles of copper (II) ortho-methylbenzoate. A b r i g h t green p r e c i p i t a t e immediately formed, and the mixture was s t i r r e d f o r f i f t e e n minutes. The p r e c i p i t a t e was f i l t e r e d and washed severa l times wi th petroleum ether ( b p - 3 0 - 6 0 ° ) . The p r e c i p i t a t e was then heated over V^O^) as descr ibed above f o r two hours . Copper (II) meta-methylbenzoate monoaniline To a s t i r r i n g mixture of 0.065 moles of a n i l i n e i n 125 ml benzene was added 0.0025 moles of anhydrous copper (II ) meta-methylbenzoate An emerald-green s o l u t i o n formed which was evaporated to near dryness . A dark-green p r e c i p i t a t e which formed was washed severa l times with pet ether (30-60) and then placed i n a vacuum dess i ca tor and pumped on for a few days. The compound analyzed as the b i s a n i l i n e adduct. Attempts to remove the one mole ,of a n i l i n e by heat ing over a s descr ibed above, were unsucces s fu l . 16 The monoaniline adduct was f i n a l l y made by a d d i t i o n of 0.0209 moles of the .copper (II) s a l t , to a s t i r r i n g mixture of 0 „ 0 2 1 moles a n i l i n e i n 100 ml benzene. A green s o l u t i o n formed which was then evaporated to dryness . The dark-green product was then d r i e d i n a vacuum dess i ca tor over ^ 2^5 with constant regu lar r e g r i n d i n g of the sample. Copper (II) para-methylbenzoate monoaniline To a s t i r r i n g mixture of 0.0102 moles of a n i l i n e i n 80 ml benzene was added 0.009 moles of anhydrous copper (II) para-methylbenzoate. An emerald-green p r e c i p i t a t e formed and was f i l t e r e d , then washed severa l times wi th benzene. I t was then placed i n a vacuum des s i ca tor over ?2®$ and pumped on for a few days to remove excess a n i l i n e . Copper (II) ortho-bromobenzoate monoaniline To a s t i r r i n g mixture of 0.043 moles of a n i l i n e i n 80 ml benzene was added 0.023 moles of the anhydrous copper (II) s a l t . A green p r e c i p i t a t e formed which was f i l t e r e d , then washed severa l times with benzene. The green product was then placed i n a vacuum dess i ca tor over P^O^ and pumped on f o r severa l days to remove excess a n i l i n e . Copper (II) meta-bromobenzoate monoaniline To a s t i r r i n g mixture of 0.00975 moles of a n i l i n e i n 80 ml benzene was added 0.0086 moles of anhydrous copper (II) meta-bromobenzoate. A dark-green s o l u t i o n formed. Upon evaporat ion to dryness a dark-green product was obtained and i t was washed severa l times with benzene. I n i t i a l a n a l y s i s i n d i c a t e d that greater than one mole of a n i l i n e was present . The compound was then heated over ^2^5 a t t * a e temperature of b o i l i n g C C l ^ under vacuum (10 mm Hg) for approximately f o r t y minutes . TABLE 2 ANALYTICAL RESULTS Found (7.) C a l c u l a t e d (%) Compound C H N Cu C H N Cu Cu (ID B z 0 An 60.11 4.48 3.67 15.87 60.22 4.27 3.51 15.69 Cu (ID o-MeBzPyr 61.10 4.48 3.52 15.49 60.90 4.59 3.38 15.42 Cu (ID o-MeBz An 61.70 4.66 3.39 15.10 61.90 4.23 3.29 14.90 Cu (ID m-MeBz Pyr 60.91 4.78 3.45 15.58 60.90 4.59 3.38 15.42 Cu (ID m-MeBz An 61.85 4.66 3.33 14.86 61.90 . 4.66 3.29 14.90 Cu (ID m-MeBz An 60.62 4.60 - 14.92 61.90 4.66 3.29 14.90 Cu (ID o-BrBz Pyr 42.00 2.52 2.61 11.92 41.84 2v38 2.57 11.72 Cu (ID o-BrBz An 42.35 2.60 - 11.54 43.13 2.70 2.52 11.42 Cu (ID m-BrBz Pyr 42.06 2.49 2.51 11.59 41.84 2.38 2.57 11.72 Cu (ID m-BrBz An 43.34 2.69 2.61 11.59 43.13 2.70 2.52 11.42 Cu (ID p-BrBz An 43.37 2.89 2.66 11.63 43.13 2.70 2.52 11.42 Cu (ID o-ClBz An 51.16 3.11 3.23 13.69 51.34 3.21 3.00 13.60 Cu (ID o-BrBz 36.47 1.64 13.92 36.24 1.73 - 13.70 Cu (ID ° - B r B z 34.72 2.09 - - 34.90 2.08 - -H 2 0 Cu (ID p-NO-Bz 52.42 3.10 10.35 - 52.03 3.25 10.12 -2Pyr Cu (ID m-ClBz 55.67 3.93 - - 55.99 3.94 5.00 - • 2An Bz = benzoate An = a n i l i n e Pyr = p y r i d i n e Me = methyl Br = bromo CI = c h l o r o 18 Copper (II) para-bromobenzoate monoaniline To a s t i r r i n g mixture of 0.0075 moles a n i l i n e i n 200 ml benzene was added 0.0056 moles of anhydrous copper (II) para-bromobenzoate. A green p r e c i p i t a t e immediately formed and was f i l t e r e d , and washed severa l times wi th benzene. Copper (II) ortho-chlorobenzoate monoaniline To a s t i r r i n g mixture of 0.0107 moles a n i l i n e i n 200 ml benzene was added 0.00168 moles of anhydrous copper (II) ortho-chlorobenzoate . A green p r e c i p i t a t e formed which was then f i l t e r e d and washed severa l times w i th benzene. I t was then placed i n a vacuum dess i ca tor and pumped on for one day. Copper (II) meta-chlorobenzoate b i s a n i l i n e To a s t i r r i n g mixture of 0.025 moles a n i l i n e i n 200 ml benzene was added 0.00715 moles of anhydrous copper (II) meta-chlorobenzoate. A green s o l u t i o n formed and was then evaporated to dryness . The product was then placed i n a vacuum dess i ca tor and pumped on for severa l days. The product analyzed for the b i s a n i l i n e adduct. Attempts to remove one mole of a n i l i n e by heat ing over P 2 ^5 a t t * i e temperature of b o i l i n g ^ C l ^ under vacuum (10 mm Hg) were unsuccess fu l . 2.3. Analyses Copper was determined i o d o m e t r i c a l l y us ing 0.01 molar sodium thiosulphate s o l u t i o n (24). Carbon hydrogen and n i trogen analyses were obtained i n the m i c r o a n a l y t i c a l laboratory of th i s department. The analyses are shown i n Table 2. 19 2.4 Solubility tests Crude solubility tests of the copper (II) salts were conducted i n dichloromethane, benzene, chloroform, carbontetrachloride • and acetonitrile. 2.5 Magnetic susceptibility measurements 2.5.1. Gouy method Magnetic susceptibility measurements employing the Gouy method were made using two separate apparatus. A l l room temperature susceptibilities were measured employing a microbalance and a permanent magnet (ca. 7000 Gauss with a 13 mm pole gap). For a l l the compounds studied the results reported are the average of at least three separate determinations (each involving repacking of the Gouy tube). . Variable temperature measurements of susceptibilities were determined using an electromagnet and semi-microbalance (25). Susceptibilities were measured over the range 333°K to 77°K at a f i e l d strength of approximately 8000 Gauss. A l l compounds were also tested for f i e l d dependence at approximately 4000 Gauss. Gouy tubes of between 3 and 4 mm inner diameter pyrex glass tubes were used. They were calibrated with a gravimetrically analyzed Nickel (II) chloride solution (26). Room-temperature moments were calculated from the expression u - 2.84 /(X - N a) T; where, X is the corrected molar err m m susceptibility, and Na is the temperature-independent paramagnetic contri-bution per gram-ion of copper. A value of 60 x 10 ^ for N a was used in the calculation of the magnetic moments for a l l compounds. Diamagnetic corrections were obtained from data of Lewis et. a l . (8), Earnshaw (2), Foex (27) and the Handbook of Chemistry and Physics (28). 20 2 . 5 . 2 , Faraday method Room temperature s u s c e p t i b i l i t y measurements were a l so measured employing the Faraday method. T h i s was done i n order to obta in an accurate as pos s ib l e gram s u s c e p t i b i l i t i e s and to check the accuracy of the Gouy r e s u l t s . An Alpha model 9500 water-cooled 6" electromagnet, equipped with t ip s of Heyding design (1%" pole gap) was used. Samples were suspended i n a quartz bucket from a Cahn Rg e l e c t r o b a l a n c e . Measure-ments were performed, i n a n i t r o g e n atmosphere, at regions of H dH/dx of 2.53 x 10 , 5.26 x 10 and 8.69 x 10 (Gauss /cm) to check f o r any f i e l d dependence.of the samples. A l l the samples were f i e l d independent. I t can be seen from Table 5 that the agreement between the Faraday and Gouy method i s qui te good. The average percentage d i f f erence was 2.817.. Th i s i s qui te acceptable s ince the accuracy of the Gouy i n most cases i s no b e t t e r than 37>. Since the main e r r o r i n the Gouy method a r i s e s from nonuniform sample packing , the Faraday r e s u l t s were used i n the c a l c u l a t i o n s s ince the Faraday r e s u l t s are not a f f ec ted by nonuniform packing of the sample. 2 .6 . E l e c t r o n i c spectra V i s i b l e and u l t r a v i o l e t s o l u t i o n spectra were measured us ing a Bausch and Lomb "Spectronic 600" spectrophotometer. " P y r o c e l l " g lass c e l l s of 1 cm path length were used. The molar a b s o r p t i v i t y , a , was c a l c u l a t e d from the Beer-Lambert law equat ion: a = A. be Where b i s the path length (cm) c i s the concentrat ion ( m o l e s / l i t r e ) A i s the absorbance 21 Di f fuse r e f l e c t a n c e spectra were measured us ing a d i f f u s e re f l ec tance attachme.it f o r the "Spectronic 600" Bausch and Lomb spectrophotometer. Magnesium Carbonate U . S . P . was used as the re f l e c tance s tandard. Powdered samples were pressed between s i l i c a g lass p l a t e s . 2 .7 . Molecular weights Molecular weights i n benzene were determined (Table 3) us ing a Mechrolab Model 301A osmometer. Reagent grade b e n z i l d i s s o l v e d i n benzene was used to c a l i b r a t e the instrument . 22 TABLE 3 MOLECULAR WEIGHT DATA IN BENZENE Compound M o l a r i t y x 10" 3 Molecular wt. Molecular wt. (found) ( c a l c . f o r dimer) copper (II) ortho-bromo-benzoate monopyridine 3.20 923 1086 copper (II) meta-bromo-benzoate monopyridine 2.05 1040 1086 copper (II) ortho-methyl-benzoate monopyridine 3.05 864 824 23 CHAPTER I I I RESULTS 3 .1 . Magnetic s u s c e p t i b i l i t y s tudies The magnetic s u s c e p t i b i l i t y data are summarized i n Tables 4, 5 , 6 and Figures 3 - . 1 2 , 21, 22. I t i s apparent that the compounds s tud ied f a l l i n t o two magnet ica l ly d i s t i n c t groups. Group I which inc ludes a l l the p y r i d i n e adducts and a l l the a n i l i n e adducts of the copper (II) o r t h o - s u b s t i t u t e d carboxy la tes , e x h i b i t moments i n the range 1.35 - 1.51 Bohr Magnetons ( B . M . ) . The Xm-T curves are t y p i c a l of b i n u c l e a r copper (II) carboxylates . The magnetic s u s c e p t i b i l i t y data was f i t t e d using a t h e o r e t i c a l express ion for two paramagnetic centers which i n t e r a c t i n such a manner as to form lower s i n g l e t and upper t r i p l e t e l e c t r o n i c s ta tes and a term that allows for a smal l c o n t r i b u t i o n from magnet ica l ly d i l u t e i m p u r i t i e s (Equation 5 ) . X = x m 0.453 + Na + (1-x) 2 2 -1 S^g- (1 + 1/3 exp 2J/kT) where the constant 0.453 i s der ived by assuming the magnet ica l ly d i l u t e impur i ty to have a normal room-temperature moment of 1.92 B . M . The quant i ty x i s the mole f a c t i o n of the magnet ica l ly d i l u t e i m p u r i t y . Where x i s large ( i . e . > 1%) the agreement between experiment and theory us ing equation 4 was poor (see F i g . 21). T h e r e - i s however very good agreement us ing equation 4 when x i s smal l (see F i g . 22). TABLE 4 EXPERIMENTAL GRAM AND MOLAR SUSCEPTIBILITIES AND CALCULATED SUSCEPTIBILITIES ( C . G . S . , E . M . U . ) Copper ( I I ) b e n z o a t e a n i l i n e Temp ( ° K ) 1 0 6 X K 10 6 X ( e x p e r . ) m 106 X ( c a l c u l . ) m 297 1.789 919.34 920.67 253 1.783 916.96 926.28 245.4 1.803 924.89 923.84 236 1.777 914.58 919.00 233 1.777 914.58 917.00 220.2 1.770 911.81 905.67 198.4 1.698 883.25 874.62 161.8 1.475 794.83 784.27 152.0 1.390 761.12 752.48 130.2 1.167 672.69 676.75 101.0 .8653 553.05 599.55 78.0 1.103 647.05 618.67 Copper ( I I ) o - m e t h y l b e n z o a t e p y r i d i n e 77.0 .1013 180.21 110.05 88.2 .3038 96.67 149.74 112 0.1140 269.03 272.95 136 0.5253 438.71 418.64 157 0.6709 497.77 537.59 165. 0.9624 619.03 577.94 196.0 1.184 710.45 702.98 227.8 1.380 792.31 782.55 251.4 1.456 822.66 816.33 257 1.436 814.41 821.85 270 1.496 . 839.16 831.56 286 1.475 830.50 838.45 288 1.475 830.50 838.97 312.3 1.456 822.66 840.37 332.5 1.411 803.99 836.02 Copper ( I I ) o - m e t h y l b e n z o a t e a n i l i n e 83 0.1690 306.24 282.56 86,2 0.1363 292.29 289.80 101.2 0.2072 322.53 341.03 106 0.2672 348.12 362.01 122 0.4635 431.85 440.46 TABIE 4 (Continued) Temp ( C K) 10 X 10 X (exper . ) 10 X ( c a l c u l . ) 145.4 0.7525 555.12 558.50 165.4 0.9870 . 655.14 646.32 181.6 1.134 717.85 704.00 191 1.145 722.75 732.72 213.4 1.287 783.11 781.95 249 1.383 824.05 824.27 265 1.413 836.85 832.10 281 1.424 841.54 834.89 289 1.401 832.04 834.73 312 1.380 822.78 829.76 324 1.363 815.52 825.06 Copper ( I D m-me thylbenzoa te p y r i d i n e 85 0.04356 239.97 235.63 95 0.1336 277.12 293.25 104.4 0.3252 355.98 354.46 169.2 1.306 760.78 731.43 123,4 9,6759 594,58 473,64 154.8 1.109 672.51 667.92 186.8 1.225 727.36 790.77 202 1.504 842.46 827.64 212.6 1.527 851.95 846.60 226.2 1.402 800.38 864.08 252.2 1.603 883.30 880.57 269 1.632 895.26 882.39 286.4 1.650 902.69 879.07 295 1.600 882.06 875.90 308 1.591 878.35 869.61 319 1.568 868.86 863.14 Copper ( I D o-bromobenzoate p y r i d i n e 81.8 .2842 105.39 121.90 90 .2463 125.94 156.36 104.8 .06157 226.14 285.32 112.4 0.000 259.53 281.68 152.8 .5358 550.14 535.48 189.2 .8799 736.77 709.49 224 1.049 828.49 810.43 247.8 1.094 852.89 849.64 293 1.113 863.20 879.09 207.2 .9529 776.36 769.01 241.8 1.077 843.67 841.64 261 1.105 858.86 863.39 281.2 1.117 865.37 875.78 301 1.117 865.37 879.98 TABLE 4 (Continued) Temp ( K) io 6x 10 X (exper.) m 10 X (calcul.) m Copper (ID o-bromobenzoate aniline 83 .3345 459.43 464.94 89o2 .4439 520.32 492.96 102.0 .4865 544.03 566.09 109 .6020 608.31 610.58 134 .8697 757.29 765.74 165 1.144 909.78 908.07 192.6 1.265 977.29 979.64 218.8 1.332 1014.58 1010.23 238.9 1.350 1024.60 1016.40 243.2 1.357 1028.49 1016.25 252.8 1.314 1004.60 1014.42 284.6 1.283 987.31 996.97 230.6 1.357 1028.49 1015.32 295.0 1.265 977.29 988.58 311 1.274 950.02 973.99 Copper (ID m-bromobenzoate pyridine 82.7 .1183 323.69 312,72 97.8 .2185 378.04 386.49 124.8 .5250 544.28 558.10 156.6 .8921 743.39 741.04 177.6 1.070 839.88 828.36 204.8 1.188 903.87 901.78 234.8 1.247 935.88 942.01 255.8 1.275 951.03 952.14 280.6 1.279 953.23 951.14 291 1.270 948.47 947.68 300 1.261 943.47 943.57 307 1.251 938.05 939.77 Copper (ID o-chlorobenzoate : aniline 80.2 .2244 359.42 385.66 96 .5347 518.57 483.87 114 .7349 621.27 615.92 136 1.026 770.61 764.80 174 1.317 919.78 936.07 158 1.223 871.67 878.01 208 1.463 994.79 1003.71 220 1.490 1008.64 1013.81 235.4 1.508 1017.87 1019.23 258.4 1.517 1022.49 1015.51 249 1.518 1023.00 1018.45 272 1.518 1023.00 1008.50 294 1.490 948.64 992.05 314 1.452 989.15 973.42 TABLE 4 (Continued) Temp ( ° K ) 106X 106X ( e x p e r i . ) 106X ( c a l c u l . ) Copper (ID o-bromobenzoate 84.4 2.120 1218.61 1228.13 119.8 2.739 1472.95 1476.71 104 2.648 1432.77 1400.04 138.6 2.799 1502.76 1511.03 144.6 2.794 1500.45 1512.42 164 2.765 1487.01 1495.61 192.8 2.642 1429.99 1435.38 203 2.565 1394.30 1409.07 220 2.503 1365.56 1362.87 229 2.425 1329.40 1337.91 243.4 2.348 1293.71 1298.03 272 2.211 1230.21 1362.87 295 2.080 1169.48 1163.04 296 2.120 1218.61 1228.13 315 1.977 1121.74 1115.62 Copper (ID m-methylbenzoate a n i l i n e 81 5.457 2561.78 97 5.124 2419.74 110 4.849 2302.44 132.8 4.453 2133.53 154.4 4.038 1956.52 186.2 3.492 1723.63 222.6 2.763 1541.06 250.6 2.763 1412.68 291 2.550 1321.82 Copper (ID p-me thylb enz oa te a n i l i n e 81 7.144 3281.35 93 6.318 2929.03 113 5.081 2401.40 136 4.438 2127.13 164 3.835 1869.93 197 3.331 1654.95 224 3.027 1525.28 247 2.788 1423.34 295 2.590 1338.89 . 28 TABLE 4 (Continued) Temp ( ° K ) 10 6 X 10 6 X ( e x p e r i . ) 10 6 X ( c a l c u l . ) Copper (II ) m-bromobenzoate a n i l i n e 77 4.497 2776.03 108 3.037 1963.48 127.6 2.679 1763.48 152.4 2.457 1640.69 183 2.214 1505.45 209.8 2.021 1398.03 243 1.837 1295.73 295 1.640 1186.00 Copper (II ) p-bromobenzoate a n i l i n e 82.4 8.704 5117.39 112 7.198 4279.24 127.4 6.083 3658.70 154 5.041 3078.77 178 3.760 2365.86 203.4 3.584 2267.91 236.6 3.041 1965.71 293 2.428 1624.55 TABLE 5 MAGNETIC SUSCEPTIBILITY ROOM-TEMPERATURE DATA Group I Compound Temp ( ° K ) Faraday io 6x 8 Gouy 10 6 X g y e f f * -io 6 A 10 6 Xm " Cu(II ) o -BrBzH 2 0 295 1.63 +.01 1.66 1.502 223 1007.91 Cu(II)o-MeBzPyr 295 1.475+.015 1.553 1.354 222 830.50 Cu(II)m-MeBzPyr 295 1.60 +.01 1.66 1.400 222 882.06 Cu(II )o -BrBzPyr 295 1.13 +.02 1.147 1.383 260 873.07 Cu(II)m-BrBzPyr 295 1.27 +.015 1.311 1.455 260 949.02 Cu(II )o-BrBzAn 295 1.265+.005 1.310 1.478 273" " 977.02 Cu(II)o-MeBzAn 295 1.39 +.01 1.424 1.350 234 826.89 Cu(II )o -ClBzAn 295 1.49 +.02 1.51 1.431 244 940.83 Cu(II ) Bz An 295 1.79 +.01 1.936 1.434 210 923.39 Cu(II )o-BrBz 295 2.08 2.080 1.633 205 1167.08 Group I I Cu(II)m-MeBzAn 295 2.48 +.004 2.623 1.713 234 1291.97 Cu(II)m-BrBzAn 295 1.64 +.02 1.646 1.637 273 1186.00 Cu(II)p-MeBzAn 295 2.59 +.04 2.674 1.744 234 1338.89 Cu(II)p-BrBzAn 295 2.42 +.02 2.411 1.927 273 1620.09 Pyr = p y r i d i n e An = a n i l i n e t -10^ ^ = diagmagnetic l i g a n d c o r r e c t i o n 10^x = gram s u s c e p t i b i l i t y 6 8 10 X = correc ted molar s u s c e p t i b i l i t y m * c a l c u l a t e d from Faraday Xg 30 TABLE 6 ADDITIONAL MAGNETIC DATA FOR THE BINUCLEAR COMPOUNDS Compound T ( K) 7. Impurity g 2J(cm ) Reference Cu(II ) Bz An 300 8.8 2.249 334 here Cu(II ) o-Me Bz Pyr 305 .1 2.244 339 here Cu(II ) o-MeBz 250 - 2.18 312 8 Cu(II ) o-MeBz An 295 2.8 2.167 328 here Cu(II ) m-MeBz Pyr 270 1.0 2.157 300 here Cu(II ) o-BrBz 160 7.1 2.127 178 here Cu(II )o -BrBz Pyr 305 0.0 2.301 339 here Cu(II )o-BrBz An 255 4.6 2.221 284 here C u ( I I ) o - C l B z 150 - 2.14 167 8 C u ( I I ) o - C l B z Pyr 280 - 2.18 312 8 C u ( I I ) o - C l B z An 250 3.1 2.22 278 here Cu(II)m-BrBz Pyr 275 2.6 2.253 306 here 31 -to to 70.2 Figure 3 l]2.S5 155.7 .193.45 TEMP.X 241.2 233.S3 32G.G99 +- = Experimental — = Calculated C u ( n ) b e n z o a t e a n i l i n e 32 rv - • to i . • + o — = Calculated CU(IE) O - m e t h y l b e n z o a t e p y r i d i n e 33 F , ' 9 u r e 5 + = Experimental = Calculated C u ( n ) O - m e t h y l b e n z o a t e a n i l i n e 34 C u ( n ) M - m e t h y l b e n z o a t e p y r i d i n e 35 ip : a a •— = Calculated C u ( n ) O - b r o m o b e n z o a f e p y r i d i n e o r-o. ID IO CO in C5). 74.7 139.267 Figure 8 153.833 208.4 " 252^955 TEMP-.X ~ r 297.533 "1 342.039 + '= E x p e r i m e n t a l — ^ C a l c u l a t e d C u ( i i ) O - b r o m o b e n z o a t e a n i l i n e 1 i r • i i i 74.43 118.300 162.187 206.D5S 249.913 293.823 337.699 TEMP.X •Figure 9 + = E x p e r i m e n t a l — = C a l c u l a t e d C u (II) M - b r o m o b e n z o a t e p y r i d i n e 38. to — = C a l c u l a t e d CU(JI) O - C h l o r o b e n z p a t e a n i l i n e 39 C u ( n ) O - b r o m o b e n z o a f e Figure 12 T e m p ° K diffuse reflectance 1 CopperC* P B r B z ) 2 An 2 Copper ( PMeBz ) An 2 3 Copper( Bz ) An r- i i i 1 , — i 1 1 350 400 450 5CO 550 6CO 650 700 725 visible spectra (mp.) Figure 13 42 TABLE 7 i MAGNETIC MOMENTS IN ANILINE SOLUTION AND IN THE POWDERED SAMPLE Compound u (B.M. )powdered Sample A n i l i n e S o l u t i o n Cu (II) o-MeBz An 1.35 1.96 Cu ( I I ) o - C l Bz An 1.43 2.09 Cu ( I I ) m-MeBz An .1.71 1.89 Cu (II ) p-MeBz An 1.74 2.10 Cu (II) formate An 1.85 Cu (II ) formate 4H 20 1.63 43 TABLE 8 POSITION OF BAND MAXIMA (OR SHOULDERS) IN SOLUTIONS  AND IN DIFFUSE REFLECTANCE Compound (mu) Band S o l u t i o n I Band II Band I I I Di f fuse Band I Ref lectance Band II Cu (II ) o-MeBz Pyr 700 400 sh (benzene) 725 br 385 sh Cu (II) o-MeBz An 685 375 sh Cu ( II ) m-MeBz Pyr 705 br 380 sh 280 d 730 hr 375 sh Cu (II) m-MeBz An 680 280 d 685 385 Cu (II) p-MeBz An 680 br 400 br Cu (II) o-BrBz Pyr 710 400 sh (benzene) 730 br 375 sh Cu (II ) o-BrBz An 680 400 sh Cu (II) m-BrBz Pyr 730 br 375 sh Cu (II ) m-BrBz An 675 420 Cu (II ) p-BrBz An 640 br 425 br Cu (II ) o-ClBz An 685 br 380 sh Cu (II ) Bz An 685 br 385 br Cu (II) o-BrBz 680 375 b r ' d dichloromethane br broad sh shoulder 44 Group I I compounds e x h i b i t magnet ica l ly weaker i n t e r a c t i o n s than thoso>. i n group I . The former possess h igh room temperature moments (1.64 - 1.93 B . M . ) , and t h e i r X - T curves are s i m i l a r to those obtained m f o r compounds such as copper (II) formate 4H2O, and copper (II) benzoate 3H„0 which are known to have polymeric s t r u c t u r e s . The l / ( x -60) vs T Z m curves for the group II compounds are l i n e a r and obey Curie-Weiss law. They are shown i n F igure 12. The room temperature moments of 1.71, 1.64 and 1.74 B . M . for copper (II) meta-methylbenzoate a n i l i n e , copper (II) meta-bromobenzoate a n i l i n e and copper (II) para-methylbenzoate a n i l i n e r e s p e c t i v e l y , i n d i c a t e that some ant i ferromagnet ic i n t e r a c t i o n i s o c c u r r i n g i n these compounds. Copper (II) para-bromobenzoate a n i l i n e ex-h i b i t e d a normal room temperature moment of 1.93 B . M . 3.2. E l e c t r o n i c Spectra In s p i t e of the d i f f e r e n t magnetic proper t i e s of the two groups of compounds, t h e i r d i f f u s e re f l e c tance s p e c t r a ( D . R . S . ) are qu i te s i m i l a r , and are shown i n Figures 13, 14, 15, 16 and Table 8. Group II compounds a l l d i s p l a y broad maxima i n the "700"miJ reg ion (band I) and i n the "400"my reg ion (band I I ) . T h e i r spectra resemble those of the mono-ani l ine adducts of copper (II) succ inate and copper (II) g lu tara te which show room-temperature moments of 1.60 and 1.73 B . M . r e s p e c t i v e l y (19). 45 The D . R . S . of group I compounds, shown i n Figures 13, 14, 15 and 16 are f a i r l y t y p i c a l of compounds that possess the b i n u c l e a r s t r u c t u r e (4 ,8 ) . A broad maxima occurs at band I and a shou lder , poor ly d e f i n e d , i n some cases , occurs at band I I . The v i s i b l e s p e c t r a of soma compounds d i s s o l v e d i n a n i l i n e are shown i n Figures 17 and 18. The maxima at "400" my i s re ta ined i n a l l the compounds. In fac t the shoulders present i n the group I compounds now appear as d i s t i n c t maxima i n a n i l i n e s o l u t i o n . The broad maxima at band II present i n re f l ec tance and i n benzene s o l u t i o n for copper (II) meta-methylbenzoate a n i l i n e i s not present i n dichloromethane. The u l t r a v i o l e t spec tra of copper (II) meta-methylbenzoate monoanil ine and copper (II) meta-methylbenzoate monopyridine i s shown i n s o l u t i o n i n dichloromethane i n F igure 18. They are almost i d e n t i c a l and r e v e a l the presence of d i s t i n c t absorpt ion maxima at 240 my (band I I I ) having molar absorptions of 27,000 and 23,000 £ cm moles ^ r e s p e c t i v e l y . A broad shoulder appears at approximately 280 my. Band I I I i s a l s o present at approximately 250 my i n the u l t r a - v i o l e t spectrum of copper (II) acetate monohydrate i n 95% ethanol s o l u t i o n (39). .3.3 Molecu lar weight determinations The molecular weight data shown i n Table 3 i n d i c a t e that the copper (II) ortho-bromobenzoate, meta-bromobenzoate, and or tho -methylbenzoate monopyridine adducts are dimers i n benzene. (/) 1 1 : 1 1 1 i i 1 1 400 5CO 6CO 700 750 Figures visible spectra ( m / x ) 1 Cu (OMe Bz)2- PYR.in Benzene ( 2.04 x lO'Violor) 350 40O 450 500 550 600 650 700 25 750 Figure is v i s i b l e s p e c t r a ( ITI/LO 350 CH 2CI 2 1 Cu (MMaBz)PYR. 2 Cu(MMe Bz ) - An 2 3 Cu (MMeBz) PYR. 2 300 -250 " 200-I5Q IOO-50-Spectrum diffuse diffuse dichloromethane(5.4l xlO"3 molar) dichloromethane (4.85 x IO"3 molar) 00 *C D > v i_ o a) o c o a Q) <+-Q) i _ <D 00 D «+-4-X 3 350 400 450 500 550 6CO i : 1 r r 650 700 25 Figure 16 visible spectra (m/x) oo a ) -) , , , , , , , 3 5 0 4 C O 4 5 0 500 5 5 0 6 0 0 6 5 0 7 0 0 ( m//J.) Figure 17 visible s p e c t r a in aniline 3 Q 3 5 0 4 0 0 4 5 0 5 0 0 5 5 0 6 0 0 6 5 0 700(m/Li.) Figure ie visible s p e c t r a in aniline 51 2 3 0 2 5 0 2 7 5 3 0 0 3 2 5 3 5 0 30O Figure 19 P r o p o s e d s t ructure for C u C O C H R B B V I I O B = aniline R = C H 3 or B r can also be in the metapositionj not shown are the two [ C G 2 C 6 H 4 R ] units that are e a c h joined to the C u atoms on opposite sides and JL to the plane of the paper. F i g u r e 20 3.4 Solubility tests Except for the compounds in Section 3.3 which were just sufficiently soluble in benzene to obtain molecular weight data, all the compounds were very insoluble in dichloromethane, benzene, chloro-form and carbcntetrachloride. In all cases the solubility is less than -4 10 molar which is below the limit of concentrations required to -3 perform molecular weight measurements (10 molar)• 54 CHAPTER IV DISCUSSION 4.1 S truc ture and bonding In view of s i m i l a r i t i e s of magnetic and s p e c t r a l proper t i e s (and molecular weight data) of the group I compounds wi th known b i n u c l e a r compounds i t i s probable that the group I compounds a lso possess the b i n u c l e a r s t r u c t u r e . Agreement between experimental and t h e o r e t i c a l s u s c e p t i b i l i t y data i s good when c o n t r i b u t i o n from a smal l amount of p a r a -magnetic impuri ty i s i n c l u d e d . ( a s shown i n Figures 21 and 22) . These i m p u r i t i e s may be due to polymeric b a s i c s a l t s of copper (II) carboxylates having the formula Cu (II) RC00 2 (OH) (8) or cupr ic oxide (13). More probably these i m p u r i t i e s are due to smal l amounts of polymeric m a t e r i a l , i n which the copper atoms are not br idged i n p a i r s , present i n the sample. EPR s tudies have confirmed the presence of magnet ica l ly d i l u t e i m p u r i t i e s i n b i n u c l e a r copper (II) carboxylates (22, 30, 36). I t appears that regardless of the nature of the t ermina l l i g a n d and i r r e s p e c t i v e of the pKa of the parent ac id a l l the o r t h o -s u b s t i t u t e d copper (II) a r y l carboxylates s tudied i n t h i s work possess the b i n u c l e a r s t r u c t u r e . Thompson e t . a l . (8) and Lewis e t . a l . (22) have found t h i s s t e r i c e f f e c t to h o l d true for other or tho - subs t i tu ted copper (II) a r y l c a r b o x y l a t e s . In a d d i t i o n , the p y r i d i n e adducts always e x h i b i t greater magnetic i n t e r a c t i o n than the a n i l i n e adducts which i n turn show a greater degree of magnetic i n t e r a c t i o n than the copper (II) or tho - subs t i tu ted benzoates themselves. C3 IP 50.0 100.0 F i g u r e 2 1 150.0 200.0 TEMP.X 250.0 300.0 350.0 + = E x p e r i m e n t a l = C a l c u l a t e d C u C u ) M - b r o m o b e n z o a t e p y r i d i n e C u ( 1 1 ) O - m e t h y l b e n z o a t e p y r i d i n e 57 The l a r g e s t d i f f e r e n c e i n magnetic i n t e r a c t i o n between the a n i l i n e and p y r i d i n e adducts occurs for both the ortho-bromo- and o r t h o - c h l o r o -d e r i v a t i v e s . They have d i f ferences of 22 cm 1 and 34 cm 1 i n t h e i r 2J values r e s p e c t i v e l y . Smaller d i f ferences i n magnetic i n t e r a c t i o n occur for the p y r i d i n e and a n i l i n e adducts of copper (II) or tho-methyl -benzoate and copper (II) benzoate. I t a l so appears that where the l e v e l o f magnetic i n t e r a c t i o n i n the anhydrous compound i s qu i te low, as i s the case f o r copper (II) ortho-bromo- and ortho-chlorobenzoate(2J = 178 and 167 cm L r e s p e c t i v e l y ) , a n i l i n e s u b s t i t u t i o n g r e a t l y increases the i n t e r -a c t i o n . The increase i n i n t e r a c t i o n upon a n i l i n e s u b s t i t u t i o n i s not so marked when the l e v e l of i n t e r a c t i o n i s found to be qui te h igh In the anhydrous compound. This i s the case for copper (II) ortho-methylbenzoate. I t i s not unreasonable that the monopyridine compounds have greater magnetic i n t e r a c t i o n than the monoaniline compounds, s ince p y r i d i n e , being a s tronger base than a n i l i n e can more e f f e c t i v e l y reduce the unfavorable p o s i t i v e charge dens i ty on the copper atoms. For the group II compounds the quest ion ar i ses as to whether these too have b i n u c l e a r s t ruc tures or whether they are .po lymer ic with s t r u c t u r e s perhaps l i k e that depicted i n Figure 20. The spec tra proper t i e s of the two groups are very s i m i l a r both showing bands I and I I . I f we assume that the presence of band I I i s i n d i c a t i v e of a b i n u c l e a r s t r u c t u r e as has been done by a number of authors (4, 6, 8)., then we would conclude that group I I compounds as w e l l as the group I compounds possess b i n u c l e a r s t r u c t u r e s . In an attempt to determine the v a l i d i t y of the "band II c r i t e r i o n of a b i n u c l e a r s t ruc ture" for the present compounds we s tudied s o l u t i o n s of a number of the compounds i n a n i l i n e . The r e s u l t s , shown i n 58 Figures 17 and 18 i n d i c a t e that a l l the compounds give maxima at approx-imately 400 my i n a n i l i n e . Moreover the magnetic s tudies done on these s o l u t i o n s show that the compounds are not b i n u c l e a r i n s o l u t i o n . I t i s concluded therefore that the 400 band i n these a n i l i n e adducts i s a property of the a n i l i n e - c o p p e r bond (charge t rans fer ) and cannot be used as a c r i t e r i o n of s t r u c t u r e . The band at 700 my (band I) i s present i n a l l s i x coordinate copper (II) s p e c t r a and ar i ses from d-d t r a n s i t i o n s from e i t h e r dz^—~> d x 2 _y2 o r a dxz, dyz —--> dx2 -y2 e l e c t r o n promotion (34, 37, 38). The p o s i t i o n of the band i s genera l ly s e n s i t i v e to the nature of the t ermina l l i g a n d . A s h i f t to lower wavelength ( b l u e - s h i f t ) has been observed by M a r t i n e t . a l . (19) upon s u b s t i t u t i o n of p y r i d i n e by a n i l i n e for copper (II) a,ui d i c a r b o x y l a t e s . A s i m i l a r e f f e c t i s observed here i n the d i f f u s e re f l e c tance spec tra (Figures 13, 14, 15 and 16) . The p y r i d i n e adducts show absorpt ion maxima at wavelengths genera l ly greater than 700 my whi le the a n i l i n e adducts have t h e i r absorpt ion maxima o c c u r r i n g at l e ss than 700 my, u s u a l l y between 675 and 685 my. Copper (II) para-bromobenzoate a n i l i n e shows the greatest s h i f t to lower wavelength having a broad maxima i n the reg ion 635 - 685 my. Band I I has been the subject of cons iderable i n t e r e s t i n recent y e a r s . Some authors b e l i e v e the t r a n s i t i o n to be d-d i n o r i g i n (33, 37 and 38). Other authors however, f e e l that the promotional energy invo lved i s probably too large and the band ar i se s from a charge' t r a n s f e r between l i g a n d carboxylate o r b i t a l s and d o r b i t a l s (32, 39) . M a r t i a l e t . a l . performed Hiickel molecular o r b i t a l c a l c u l a t i o n s on b i n u c l e a r copper (II) acetate monohydrate and ass ign the t r a n s i t i o n as a r i s i n g from a charge 59 t r a n s f e r promotion of an e l e c t r o n from a l ow- ly ing f i l l e d l i gand o r b i t a l to an empty dx^ -y2 o r b i t a l npu > 6* dx^ - y ^ . The shoulder at 280 m\i i s c h a r a c t e r i s t i c of oxygen conjugated to an aromatic r i n g (40). The magnetic proper t i e s of group I and I I compounds are so d i f f e r e n t that i t i s reasonable to conclude that the group II compounds are not b i n u c l e a r . The magnetic and s p e c t r a l proper t i e s of the group I I compounds are i n c lose agreement with those of some monoaniline adducts of some copper (II) a lky l carboxy la te s and copper (II) a,co d icarboxy la tes s tud ied by M a r t i n e t . a l . (19). These authors suggested that on the bas is of s i m i l a r s p e c t r a l features exh ib i t ed by t h e i r compounds and the fac t that the magnetic data could be f i t t e d to Equation 4, that t h e i r compounds possessed the b i n u c l e a r s t r u c t u r e . The present author f e e l s , however, that al though the experimental data of M a r t i n e t . a l . agree qu i te w e l l i n some cases wi th the t h e o r e t i c a l data th i s i s i n no way conc lus ive evidence f o r a b i n u c l e a r s t r u c t u r e . I t i s not inconce ivable to envisage s p i n - s p i n i n t e r a c t i o n of two copper atoms occurr ing between copper atoms on adjacent chains i n a polymeric s t r u c t u r e as shown i n Figure 20. I t i s p o s s i b l e that group I I compounds may possess t h i s polymeric s t r u c t u r e . A polymeric s t r u c t u r e has been shown to occur f o r copper (II) benzoate t r i h y d r a t e i n which each copper atom i s br idged by one benzoate group and two water mole-cules to two d i f f e r e n t copper atoms forming l i n e a r chains of the formula (Cu (II) CgH,_ COO (H20)2 n + (with the benzoate groups a l t e r n a t i n g p o s i t i o n s on e i t h e r s ide of the Cu-Cu axis) and a chain un i t (H^O) b e n z o a t e 1 1 O i n t e r v e n i n g between the chains . The copper-copper dis tance i s 3.15 A o which i s intermediate i n length between a syn-syn arrangement (2.64 A) and an a n t i - a n t i arrangement (5.20 A ) . 60 4.2 Concerning the ease of formation of the monoamine adducts A l l the monoaniline and monopyridine adducts of or tho-subs t i tuted-benzoate complexes were prepared by r e a c t i n g an excess of base wi th the copper CH) s a l t ( i . e . base: Cu r a t i o > 1). Th i s y i e l d e d presumably b i s a n i l i n e and b i s p y r i d i n e adducts from which one mole of base could e a s i l y be removed to form the b i n u c l e a r adduct. The monoanil ine and monopyridine adducts of copper (II) ortho-bromobenzoate, copper (II) ortho-methylbenzoate and the monoaniline adduct of copper (II) or tho -chlorobenzoate were made i n t h i s manner. S i m i l a r procedures were used by Lewis e t . a l . to prepare copper (II) benzoate p y r i d i n e (II) and copper (II) ortho-chlorobenzoate p y r i d i n e (8). In the case of copper (II) meta-methylbenzoate and copper (II) meta-bromobenzoate the previous procedure was used and the monopyridine adducts were e a s i l y obta ined. Thi s procedure d i d not work for copper (II) para-n i trobenzoate . Excess p y r i d i n e r e a c t i n g wi th the anhydrous copper (II) complex r e s u l t e d i n formation of the b i s -p y r i d i n e adduct. Attempts to remove one mole of p y r i d i n e were unsuccess fu l . L i n and Thompson us ing the same procedure were unsuccess fu l i n t h e i r attempts to completely remove one mole of p y r i d i n e from copper (II) p a r a -chlorobenzoate b i s p y r i d i n e (7). B i s a n i l i n e adducts of copper (II) meta-methyl and meta-chlorobenzoate were obtained by a d d i t i o n of excess base ( i . e . base: Cu r a t i o > 1). Attempts to remove the one mole of a n i l i n e were unsuccess fu l . The monoaniline adducts , however, could be made by c a r e f u l a d d i t i o n of s t o i c h i o m e t r i c amounts of a n i l i n e . I f i t i s assumed that an important fac tor i n determing the ease of formation of a monopyridine or monoanil ine adduct from a b i s p y r i d i n e or b i s a n i l i n e adduct i s the formation of a b i n u c l e a r molecule then these 61 r e s u l t s can be expla ined by the fact. that, where the base i s p y r i d i n e or a n i l i n e , o r t h o - s u b s t i t u t e d copper (II) carboxylates r e a d i l y from b i n u c l e a r molecules and hence r e a d i l y form monopyridine and monoaniline adducts. On the other hand f o r meta- and p a r a - s u b s t i t u t e d benzoates the s i t u a t i o n v a r i e s depending on the. compound and base usad. I t i s not understood why i n some cases monobase adducts are r e a d i l y formed ( i . e . monopyridine adducts of copper (II) meta-bromo- and meta-methylbenzoate).while i n other cases they are not r e a d i l y formed ( i . e . monopyridine adducts of copper (II) p a r a - c h l o r o - , meta -ch loro - , and para-ni trobenzoate monopyridine adducts (7) ) . 4.3 S i g n i f i c a n c e of g values as determined from magnetic s u s c e p t i b i l i t y s tudies The g values quoted were obtained from the minimum f i t t i n g e r r o r (as expla ined i n the appendix). They are by no means accurate s ince the g values obtained are no b e t t e r than the l i m i t of the minimum e x p e r i -mental e r r o r . As shown i n Figure 23 the experimental e r r o r i s greater than, the minimum f i t t i n g e r r o r and i n fac t g can l i e i n the range 2.14 -2.2 f o r copper (II) ortho-chlorobenzoate a n i l i n e . Part of t h i s reg ion over laps the range of g values (2.14 - 2.18) observed by Lewis for some copper (II) ary l carboxy la te s (22). S i m i l a r v a r i a t i o n of g with the f i t t i n g e r r o r was observed for the other compounds s t u d i e d . The experimental e r r o r was c a l c u l a t e d as fo l lows: i Exper imenta l ly X = f g/W° 6 i and f = ( W Q - W J ) - 6 = f o r c e (mgl 62 40 2.10 Variation of error with g for C u ( n ) O - c h l o r o b e n -zoafe aniline 2.15 2.20 E x p e r i m e n t a l e r r o r B e s t , f i t e r r o r i — i 2.25 g F i g u r e 2 3 . 63 <5 diagmagnetic tube c o r r e c t i o n (jag) wo = weight of sample, f i e l d on (mg) w l = weight of sample, f i e l d o f f (mg) W° = weight of sample (g) 8 = tube constant The main e r r o r comes from A6 which increases as the temperature i s lowered and a l so from smal l (WQ - w^) va lues . Absolute errors i n reading ( W Q -W j ) and i n B were constant . The e r r o r i n reading W was smal l enough to be neg lec ted . The e r r o r at each temperature was computed as fo l lows : t the r e l a t i v e e r r o r i n X (RE X ) = (8 ± ^ 7 - x 100%) 6 8 £ (Re X ) = (RE X ) g m absolute e r r o r X x mol . wt. = (AE X ) = (RE X ) X /100 g m g m X x mol . wt. ' (AE X ) = (8 + - ^7 - x 100%) 100 f , f l ( A E X m ) 2 root mean square e r r o r (RMS) = 1 ' n-1 where n = number of data points . RMS i r i r i < 7 / and e r r o r = —— x 100% A. m S i m i l a r RMS versus g p l o t s and magnitude of experimental e r r o r were obtained for the other compounds that exh ib i t ed broad maxima i n the X - T curves . Since the g values obtained from t h i s procedure are m on ly approximate, 2 J , corresponding to the range of g 2.14 - 2.22, can 64 vary from 256 cm 1 to 278 cm 1 for copper (II) ortho-chlorobenzoate a n i l i n e . I t can be seen therefore that only approximate values of g. 2J and T can be obtained from t h i s experimental method, c 65 CONCLUSIONS 4.4. The compounds s tudied i n t h i s work f a l l i n t o two magnet ica l ly j d i s t i n c t groups. The group I compounds, which inc lude a l l the mono-p y r i d i n e adducts of a l l the or tho- and meta-subst i tuted copper (II) a r y l -carboxy la te s , and the monoaniline adducts of the or tho - subs t i tu ted copper (II) a r y l c a r b o x y l a t e s , e x h i b i t magnetic and s p e c t r a l proper t i e s that are t y p i c a l o f known b i n u c l e a r molecules . I t i s therefore qu i te reasonable to suggest that the group I compounds a l so possess the b i n u c l e a r s t r u c t u r e . In these group I compounds the magnetic i n t e r a c t i o n s i n the p y r i d i n e adducts i s greater than those i n the a n i l i n e adducts . Th i s i s cons i s tent wi th the f a c t that p y r i d i n e , being a s tronger base than a n i l i n e would be expected to more e f f e c t i v e l y reduce the r e s i d u a l p o s i t i v e charge dens i ty on the copper atoms. The fac t that a l l the o r t h o - s u b s t i t u t e d copper (II) a r y l c a r b o x y l a t e s possess the b i n u c l e a r s t r u c t u r e i r r e s p e c t i v e of the nature of t ermina l l i g a n d , or nature of subs t i tuent i n the o r t h o -p o s i t i o n , s t r o n g l y suggests that a s t e r i c e f f e c t i s present i n these o r t h o -s u b s t i t u t e d compounds. Where there are meta- and para- subs t i tuent s on the benzene r i n g , the f a c t o r s which determine whether or not a compound adopts a b i n u c l e a r s t r u c t u r e i s not understood. Although the s p e c t r a l features of the group I I compounds are qu i te s i m i l a r to the group I compounds, the magnetic proper t i e s are d i s t i n c t l y d i f f e r e n t . The magnetic i n t e r a c t i o n i s cons iderably weaker than the i n t e r a c t i o n observed for the group I compounds. The group II compounds may possess a polymeric s t r u c t u r e . 66 In view of the limited accuracy of the magnetic susceptibility measurements and the broad maxima observed for most of the binuclear compounds, only approximate values for g, 2J and T £ can be obtained. 4.5 Suggestions for further work In view of the limited accuracy of the magnetic susceptibility measurements in obtaining g values, EPR studies should be carried out on the binuclear compounds in order to obtain accurate g values. I t would then be interesting, using these values, to determine accurately the degree of magnetic interaction (2J) and the position of the maxima (T c ) . It would also be of interest to find more precisely the amount of impurity that may be present. Since binuclear and presumably polymeric compounds are obtained with the aniline adducts, i t would be interesting to prepare a series of ortho-, meta and para-substituted aniline adducts of the meta and para-substituted copper (II) arylcarboxylates, in order to examine r whether the ortho-substituted aniline adducts would exert any steric hindrance as to favor the formation of a binuclear molecule. 67 BIBLIOGRAPHY 1. B . N . F i g g i s and J . Lewis , "Modern Coordinat ion Chemistry". E d i t e d by J . Lewis and R . G . W i l k i n s . In tersc ience Pub l i shers | I n c . , New Y o r k . 1960, p . 400. 2. A . Earnshaw, "Introduct ion to Magnetochemistry". Academic Press., New Y o r k , 1968. 3. B . N . F i g g i s and J . Lewis , i n "Progress i n Inorganic Chemistry", V o l . V I . E d i t e d by F . A . Cot ton , In tersc i ence Publ i shers I n c . , New Y o r k , 1960. 4. M. Kato , H . B . Jonassen, and J . C . Fanning, Chem. Rev. _64_, 99 (1964). 5. J . N . van N i e r k i r k and R . F . L . Schoening, A c t a C r y s t . 6>, 227 (1953). 6. B . N . F i g g i s and R . L . M a r t i n , J . Chem. Soc. 3837 (1956). . 7 . Y . C . L i n and R . C . Thompson, Can. J . Chem. 46, 557 (1968). 8. J . Lewis , Y . C . L i n , L . K . Royston, and R . C . Thompson, J . Chem. Soc. 6464 (1965). 9. R . L . M a r t i n , and H. Waterman, J . Chem. Soc. 1359 (1959). 10. E . Kokot and R . L . M a r t i n , Inorg . Chem. _3, 1306 (1964). 11. J . Lewis and 'F . Mabbs, J . Chem. Soc. 3894 (1965). 12. Y . Inoue, M. K i s h i t a , and M. Kubo, Inorg . Chem. _3> 239 (1964). 13. C . S . Founta in , and W.E. H a t f i e l d , Inorg . Chem. 4_, 1368 (1965). 14. R. Kir iyama and K . I . Ibamoto, Acta C r y s t . _7, 482 (1954). 15. G . A . Barc lay and C . H . L . Kennard, J . Chem. Soc. 3289 (1961). 16. - H . Ko izumi , K . Osaki and T . Watnabe, J . Phys. Soc. Japan, 18, 117 (1963). 17. R . L . M a r t i n and H . Waterman, J . Chem. Soc. 2545 (1957). 18. R . L . M a r t i n and H . Waterman, J . Chem. Soc. 2960 (1969). 19. L . D u b i c k i , C M . H a r r i s , E . Kokot and R . L . M a r t i n , Inorg . Chem. 5_, 93 (1966). 20. R . C . Thompson and D.B.W. Yawney, Can. J . Chem. 43, 1240 (1965). 21. J . Lewis and R . C . Thompson, Nature 200, 468 (1963). 68 22. J. Lewis, F.E. Mabbs, L.K. Royston, and W.R. Smail, J. Chtm. Soc. 291 (1969). 23. R. Whyman, W.E. Hatfield, and C.S. Fountain, Inorg. Chemica Acta 1, 429 (1967). ! ~ 24. H.A. Laitmen, "Chemical Analysis". McGraw H i l l , New York, 1960. 25. H.C. Clark and R.J. O'Brien, Can. J. Chem. 4., 350 (1965). 26. H.R. Nettleton and S. Sugden, Proc. Roy. Soc. A, 173 (1939). 27. G. Foex. "Diamagnetisme et Paramagnetisme". Masson and Co., Paris, 1957. 28. R.C. Weast and S.M. Selby (Editors), Handbook of Chemistry and Physics, 46th ed. Chemical Rubber Publishing Co., Cleveland, Ohio, 1965-66. 29. W.E. Hatfield, C.S. Fountain and R. Whyman, Inorg. Chem. 11, 1855 (1966). 30. F.G. Herring, unpublished results. 31. Y.C. Lin, M.Sc. thesis, University of British. Columbia, Vancouver, Canada (1965). 32. G. Basu, R.L. Belford and R.E. Dickerson, Inorg. Chem. 1, 438 (1962). 33. D.P. Graddon, J. Inorg. Nucl. Chem. 14, 161 (1960). 34. D.P. Graddon, J. Inorg. Nucl. Chem. 17, 222 (1961). 35. A.B. Lever, J. Lewis and R.S. Nyholm, J. Chem. Soc. 5262 (1969). 36. F.G. Herring, R.C. Thompson and CF. Schwerdtfeger, Can. J. Chem. 47, 555 (1969). 37. C.W. Reimann, G.F. Kokoszka, and G. Gordon, Inorg. Chem. _4, 1082 (1965). 38. S. Kida, Y. Nakashima, Y. Morimoto, K. Niimi, and S. Yamada, Bull. Chem. Soc. Japan, _37, 549 (1964). 39. L. Dubicki and R.L. Martin, Inorg. Chem. 13, 2203 (1966). 40. S.F. Mason, Quart. Rev. 15, 287 (1961). 41. J.C.S. Scott, B.Sc. thesis, University of British. Columbia, Vancouver, Canada (1965). 42. I.R. Wasson, C.I. Shyr, and C. Trapp. Inorg. Chem. _3» 469 (1968). 69 APPENDICES 70 ANALYSIS OF MAGNETIC SUSCEPTIBILITY DATA (By: K.N. Shaw) An a n a l y s i s of the temperature dependent magnetic s u s c e p t i b i l i t y data f o r a given compound, under the assumption that an a d d i t i o n a l magnetic species may be present, involves the determination of three parameters: i g-factor, g i i Curie temperature, T c and i i i f r a c t i o n a l c o n t r i b u t i o n of the a d d i t i o n a l species, X. That i s , we may express f (T) defi n i n g the molar magnetic s u s c e p t i b i l i t y , X (T), as a fun c t i o n of the independent v a r i a b l e T i n the general form: f (T) = (1-X) f x (T) + X f 2 (T), 0 £ x ^ 1 (1) where: f l (T) = k E 2 + ( l ) a . T (1 + 1/3 ex P(1.60T c/ T) N / , 3K N i ( = temperature independent paramagnetic term N «< 60.0 x I O - 6 f 2 ( T ) = 0^53 + ( 1 ) b < The function f ^ (T) then defines the magnetic s u s c e p t i b i l i t y associated with an i n t e r a c t i n g two-spin system, and f-^ (T) defines that associated with an a d d i t i o n a l magnetic species obeying the normal Curie law. 71 To determine the aforementioned parameters, we consider a least-squares best f i t analysis of the experimental data. We require to f i t a set of n data points (X^T^ to the function f (T^a..), c f . eg. (1) The m parameters (j = 1, m) may be considered as generalized variables. In accordance with the principle of least squares fitting, the parameters are determined to minimize the function^"^: = i - f ( T f , (2) The function F^  which is continuous and differentiable, is minimized by setting all derivatives of the form equal to zero and solving the resulting set of normal equations. However, the parameters a., are not linearly independent and therefore lead to a set 'of non-linear normal equations which cannot be solved directly. For m parameters a., the total derivative F^  is defined as: j ' , 30-i J - * J (3) Equation (3) shows that for given values of a_., F^  is linear in the derivatives ^ j . Thus we may apply the least-squares fitting procedure in terms of F^  and 4 j to obtain effective linearisation. Neglecting all derivatives higher than first order, the normal equations then take the general form: 72 "sswhere: f. = f (T., a:) 1 1 j Hhese equations are conveniently expressed in matrix form for computational -purposes as: £> I - 1 (5) w^here: j "Assuming Q to be non-singular, Equation (5) is readily solved for the incremental parameters / j j« The general iterative procedure used to determine the parameters aj corresponding to the least-squares best f i t may now be summarized as follows: i choose approximate values for a., j = 1, m i i evaluate all derivatives of the form ——: . i i i calculate 4 j in accordance with Equation (5) iv re-define parameter aj as the better approximation aj + Aj, 4 J ^ - 0 v if 4. j ^  ^ return to (ii), where £ is a specified limit value for the incremental parameter ^ j . From a consideration of the form of the derivatives involved for the particular ^function under consideration, to eliminate the possibility of divergence in ->sthe-overall fitting procedure the parameter 'J is allowed to increment over a. chosen temperature interval and the remaining parameters, g and x are Fssolved for simultaneously. . uiSThe fitting error, -is defined in accordance with the gauss (2) -^criterion as: il r * ^ '2 (6) -where: - f i =—value corresponding „to,temperature T^  calculated from the best f i t functional relationship given in general form in Equation (1). The best overall f i t to the experimental data is then considered as that corresponding to the minimum value of _/2_ . By incre-menting T c from above and below a best f i t value, i t was shown that XI. was an absolute minimum and that i t corresponded to a consistent set of parameters g, T £ and x. The best f i t analysis was carried out on an IBM 7044 computer using a FORTRAN IV G program BENFIT consisting of the following routines: i BENFIT: Control program defining input parameters and data and associated FORMAT i i BMAIN: Main program controlling the overall iterative fitting procedure, evaluation of errors and output data iv ;LSQFIT: •FUNC: tSOLVEX: "TPLOT: General least-squares fitting program using -normal equation linearization as based upon Equation (5). This program includes an array MD(J) which controls the parameters being -varied in the fitting procedure, i.e. g or x smay be varied.alone or simultaneously, program for the evaluation of the function f, c f . Equation (1) and the necessary ^derivatives c.f. Equation (5). ^^ rogram.-.£or,_.the^ olution.-of~-Equation-- (5) "Program'for plotting output data showing ^resultant best-fit curve for given input experimental data and variable parameters. .The program has been shown to consistently converge to the best f i t parameter values using.only 4-6 sees. CPU time on the IBM-7044 A listing of the source program is included for reference following this appendix. REFERENCES: (1) M.R.Spiegel "Theory and Problems of Statistics" Schaum Publishing Company, N.Y., p.189, 1962 (2) D.D.McCracken and W.S.Dorn "Numerical Methods" John Wiley and Sons, Inc., N.Y., p.283, 1966 S P A U S E MOUNT T A P E _ —STJO'B" i"5"07+6 • "K_.M.'S"HA« ! $PAGE 6 0 ST I ME 1 0 "STB'F T'C~B EN FTT'~~ : C C PROGRAM FOR F I T T I N G M A G N E T I C S U S C E P T I B I L I T Y DATA -~C " ITEA'S-T-S'QtTA R E'S~_CR" I"T E R ' I O N " C C PROGRAM FOR IBM-7 0 4 4 BY KNS — C ~ ~ - ~ : - — C I N P U T DATA • C N = NO.DATA P O I N T S ' "' c — r - r r r " " T E M P E R A T U R E . D ' E ' G V K " ~ C NOTE - T ( l ) , T ( N ) MIN,MAX TEMP C XM'(.I ) = MOLAR M A G N E T I C S U S C E P T I B I L T Y "'C ' • ~ " C HD = R E F E R E N C E DATA C I N P U T P A R A M E T E R S -_..c re ^'cuRir POINT--TEMPER"A'TDRE C T I = I N C R E M E N T C M J .= MAX.NO. I N C R E M E N T S ~ C ~VC~~C-U-R'I E~CONTR'I B U T T O N ( V A R I A B L E " ) ~ " p " ( " f " ) C VG - G-FACTOR ( V A R I A B L E ) P ( 2 ) C "~C C ON T'R'O L""T'AR ATi'E' Tfc R'S" C MD( I ) = 1 P A R A M E T E R F I T _C . EC = P E R C E N T A G E L I M I T P A R A M E T E R F I I " C : ~ ~ M P ™ " 0 PRTNT"OUTP'UT"' D'AT'A "ONLY ' C - 1 P L O T DATA __C _ N P N Oj^P L 0 T p_0J Nj 3 [f I T T E D D A T A ) . c ' " MI" =' o " S Y'NGLV DATA "SET»END~"OF" DATA c = i ' DATA S E R I E S c ~ C — " — T N P U T F ' O RMAT C HD 1 3 A 6 > A 2 C N ? MI 4 15 c T i n 8 F 1 0 o c C XM < I ) C TC >TI ,MJ 2 F 1 0 . 0 » I 5 ~C V C v V G 2 F 1 0 . 0 - •• C M D ( I ) » E C 2 I 1 » F 8 . 0 C D A T A K , p / •, / - — - •— DATA MP / 4 0 0 / CALL_ BMA I N ( MP_»_NPJ STOP '. END SIBF'TC BMAIN 5 U r 3 R c v j T j Kl BMA IN ("MP VNP") • — C DIMENSION T( lOO) »XM( 100) »Vi (20) »V2(20) »F('lOO) Dl ME'N'S'l 0'N'"H'D"( 1 AlTT p( "fO 0 0" )7X Pi TO 0"0 ) DIMENSION P ( 4 ) » D U » 1 0 0 ) » M D U ) C 1 F'( I'lP.M". 1 )" GO TO 100 " CALL PLOTS 100 READ(5'12) HD "T2 FORMAT! 13 A 6 i A 2 ) " ~ " WRITE(6*14) HD 14 FORMAT(//'13A6'A2>//) RE.fi.DT^_l. , - ~ N - - M I  1 - FORMATU15) READ < 5 »-2 ) ( T ( I ) , I = 1 »N ) 2 • F aRWA"T-( '8 F 1 070 ) " ~ READ(5'2) < XM( I ) , I = i , N) READ ( 5'15 ) l 'c»Ti ,MJ T5 FORMA"T {'ZFTOTOI'V^l READ ( 5 '2 ) VOVG READ(5»19) MTl»MT2»EC T 9 F ORM A.Tt 21T»T8 ."'0 ') C C J = Tc-ITERATI 0N INDEX. E M ~ ^ ~ r ~ - 0 F 1 - 2 — J = 1 102 TV = 1.60-Tc C - V'CVV'G"""CEAS'T-SQ0'"A"RES ' FIT ~ : — ' P<1) = VC P<2) = V'G MD'( 1 r^""MTT " MD<2) = MT2 CALL LSQFIT(T »TV >XM,N »P >MD> EC >D'F) Vl( J J - --p-!-] ) V2 < J) = P(2) C CALCULATE FITTING ERROR f.R' O.C — DO 4 I=1»N 4 ER = ER+(X M( I )-F( I ) )**2 1 F-(-E-RvG-TvEM )• • GO—T 0 '6 • : - — J  EM = ER J = J + l r e --: T o r i IF(JcLE.MJ) GO TO 10 2 J l = J - l "" WR'i"T'E'( 6''"3 ) J l ~ " " r 3 FORMAT ( 4 X » 1 3 H F IT E X I T E D A I'» I 4 * 2X * i'uH I I E-RA i I ONi »/ / ) 6 Tc = T C - T l — — T V" = ] . 6 0 * T c " _ " " ~ ' P <1) = V I ( J - l ) P ( 2 ) = V2 < J - l ) c ~ ~ ~ " ~ ~ c P R I N T OUTPUT DATA W R I T E ( 6 » 2 1 ) 2 1 FORMA T ( ? X > ] 9iF'i E"ST- F I T P AR AM E T E R 3 ) ' W R I T E ( 6 » 1 7 ) 17 F O R M A T ( / ) W R I T ; ( 6 > 1 8 ) T C " " ~ 7 " 1 8 F O R M A T ( 4 X » 4 H T C = » F 6 . 1 ) W R I T E ( 6 ' 1 7 ) W R l T r ( 6 , 2 2 ) P " T " l ) V p " ( ' 2 " j " ~ " ~ ™ ~ " " ~ " ~ " " " 2 2 F O R M A T ( 4 X » 4 H V C = » F 6 . 3 » 6 X » 4 H V G = » F 6 . 3 ) W R I T E ( 6 * 1 7 ) ~ w R 1 T [ ( 6»7") ™ " ~ " ~ " " ~ 7 FORMAT ( 4 X >32HOUTPUT DATA L E A S T - S Q U A R F 3 F I I » / / > 1 5 X » 4 H T ( I ) >7X>5HXM( I ) , 8 X , 4 H F ( I ) ) I T f ( 6 * 1 7 ) - ~ ~ ' M = 0 I M = 0 C A L L F U N C < P > " T , T V , F * N > D > M > M D V I M ) " FM = 0.0 DO 8 I = 1 * N I FT F ( I )'. GT . FM ) FM = F ( I ) : ' ~ 8 W R I T E ( 6 » 9 ) T ( I ) » X M ( I ) ? F ( I ) 9 F O R M A T ( F 9 . 1 > F 1 3 . 2 » F 1 2 . 2 ) C E V A L U A T E F I N AX" F I T TT NG "ERROR " ER = 0.0 DO 1 0 1=1»N ~ ' EX = ( X y ( I ) -p ( I ) ) - - -1 0 ER = E R + E X # P X HN = N-1 " E R = S O R T ( E R/HN ) " " " " " " " " WRI1'E<6»11) ER 1 1 FORMAT I / / » 4 X » 1 9 H R M S F I T T I N G ERROR = » F 8 . 2 ) ~ " E R P = < ER/FM ) " 1.0 0.0 " ' W R I T E ( 6 » 1 6 ) ERP 1 6 F O R M A T ( / » 2 2 X » 1 H = » F 8 . 2 ' 2 X » 7 H P E R C E N T ) '~" " I FT MP . N E . T ) " GO TO ] C 1 " ' C SUBROUTINE LSQFlT(X,Xc»Y.»N»P»MD»ER»D»YT) """GEWEkAT"TtA3T'-3TUAH'E"S~TTT'T I NG~TJ"ROGRAM NORMAL EQUATION L1NEAKISATIuN*TAYLOR EXPANSION 'DIMENSION X( l ) »Y t i ) . * r r T i 'ri PTDTMDTT y " DIMENSION A ( 4>4 ) »i3 ( 4) »D"( 4» 100 ) »DP ( 4 ) DATA MC»Ni / 1»20 / P I T T I N G P A R A M E T E R CONTROL A R R A Y * M D ( J ) i M _L>EF_IN t o A -MA T R I X D I M c N S I O N " ~ P A K T i A_'"DEi< i V'ATi V'ES"'EV A L U AT E D M = 2 IM = 0 _ _ _ " " D O "1 " J ^ 1 > M " " I F ( M D ( J ) • E O o 0 ) GO 10 1 Iivi - IM+1 ~T\WCr'F\T'~^~~3 " " C O N T I N U E I F l M C . E Q . l ) GO To 1 0 0 "vii R I T E "f6»"2T! -;D('J j •> I n) FORMAT(3X>2HMD» I 5 s 5 I 10 » / ) ~~T\1 ^n'oTA^lTOlTBLR""rTERATToN'S' ~ NT = 0 M A T R I X E L E M E N T S A ( J » K ) »B('J ) ZERO ' D O 3 J = l » I M _ D_(_J]__ ~ G.G U U 3 i * l M A ( J » K ) • = 0 o 0 C O N " Q N ' j _ £ . EVALUATE- M A T R I X E L E M E N T S A U ' M ' B U ) LC = 1. "CALL F'UNC i> '•> X'» XCVY 1'» N » D , |_ C } D O 4 1 = 1 J N D O 4 J=1,IM L " = "MDTJJ D O 5 K. = 1 » J LD = M D ( K ) ~ Wi\, » \")""-,\ ( J >Kt T'J j *:J ("'_.0 V L') ioi ' = I Y i i ) - Y T ( i ) ) * 0 ( L > I ) U i J ) = Li ( J ) + U UTPUT DATA •( iT-cr. I*T fry ( N ) + 0 . 1 * T ( N ) P TN = 2 > MP = T P ( i i J + D T = TM UNC < P » TP , T V , XP , NP , D * M » MD •> I M ) P L O T ( J » X M » T P »XP >N »NP) 6'2 3 ) 1 (1H1) G T . O ) GO To 100 E'QVl")CAi:r;--pr;oT,\ [)"""" -— V " " CONT I NUE I F t I M . G T . 1 ) GO TO 6 DP« 1 )_ = _B ( 1 ) / A( I ' D ' GO 'I w i b " " " " " , " C S Y M M E T R I C A - M A T R I X 6' 0O_ _7_ J=_l »_1 M ""' . . J B ~ = "J+I" " " " l F l J i i . G T . I M ) GO TO 7 _ J ^ _ ^ jK_=^ J ii »_1 M ' A"< J >7J = A ('< > J ) : 0 CONTINUE 7 c ci N u_.y^ji... c K E 5 E n ' i \ i £ ' : o T j ) KP = IM+1 DO 9 J=1»IM _ •) M J T K P T ' " "= "\u jj™ t C E^.Ii.B.'iLilE JfM.AilF.IER...1,NCREMENT_»PP.( :J ) C A L L o O L V L A ( A > D P ? I M ) 1 6 DO 1 0 J = I » I M ' 'K = riD ( J ) "lO r i ,\ ) = P i r, ) + DP ( J ) ~ " I F(MC.EQ.1 ) GO TO 17 ' _ • _ ^ i l 1 1 E ( 6 L 1 L±. ( P ' K )_»,<= 1 ? M ) TP''". " F 0 KM A TT4 A V 6 F 10 . "47 1 7 , N T = • N T + i .'I F I NT .GT. Nl ) GO TO 14 c C r n . c < ; p AKAM E t E R" "TN C L E M E N T " " " " " " " " " " ~ ' . ' ' " DO 12. J = l » IM _ _K =_ MD ( J ) _ _ PC = A D 31 DP ( J )7"P 1'KT)'*1 0 0 . 0 " i F ( P C . L £ . LI< ) GO TO 1 2 C _ I F ( P C . G T . 1 0 0 . 0 ) G O T O 1 4 1 GO "To" 10 0 : " ~ " " " L2 C O N T I N U E '_• .RETURN _ "'• L4~"v*'RTTIT(>'•> i -J)R 1o F O R M A T ( / / ? 4 X 5 21H u Y o T E M• NGN-CONVERGENT >//) •  NT = 0 (A L T U K ,\ ""'~ END DF1 C FuNC UL.CK ouBROU i I NE F U N C ( P » T > Tc » F » N » D > M ) d us clip" T T B i L T T Y h U N C f I O N V D E R T V AT Tv E """c A E C U L A T T O N DjVi E N o I 0 N P ( 1 ) _> J_ ( l ) >_F ( 11 > D < VP J "vc~="~p( TT~ " " " ~ " ' ~"~ " VG = P ( 2 ) CP = 1 • 0 E + 6 CA = 6 0". 0 " " " " " " " AK. = CF*0 . 1 2 5 2 0 0 10 1 = 1 >_N .__ , ] ^  ^  ;.. X P ( Y C 7 Y ( 7 , 7)73,g" F l = A K * V G * V G / E F + C A F 2 = C f- * 0 . A '3 -5 / i { J j + C A VF = 1 . 0 - V C F ( I ) = V F * F 1 + V C * F 2 I F ( M . E u . 0 ) GO 1O 10 u i 1 > J ) r i D t 2 » I ) = 2 . 0* V F * A N . - * V ' G / E F C 0 N T I iM u E RE T URN END 

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