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Donor-acceptor properties of phosphorus-sulphur compounds Le Geyt, Michael Robert 1974

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DONOR-ACCEPTOR PROPERTIES OF PHOSPHORUS-SULPHUR COMPOUNDS MICHAEL ROBERT L E GEYT B . S c , C a r l e t o n U n i v e r s i t y , 1 9 70 A THESIS SUBMITTED I N P A R T I A L FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n t h e D e p a r t m e n t o f 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 a s c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE U N I V E R S I T Y OF B R I T I S H COLUMBIA J u n e , 1974 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 a d v a n c e d d e g r e e at t h e 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 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 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 the Head o f my D e p a r t m e n t 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 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 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 . Depa r tment 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 V a n c o u v e r 8, Canada - i -ABSTRACT The c a g e m o l e c u l e -P^S^ h a s b e e n e x a m i n e d b y a v a r i e t y o f s p e c t r o s c o p i c a n d c h e m i c a l m e t h o d s i n o r d e r t o d e t e r m i n e some i n f o r m a t i o n a b o u t i t s s t a b i l i t y , i t s d i s t r i b u t i o n o f e l e c t r o n i c d e n s i t y , and a l s o a b o u t i t s d o n o r - a c c e p t o r p r o p e r t i e s . i > 4 S 3 n a s b e e n shown t o be a p o o r CT-donor a s i n d i c a t e d b y i t s l a c k o f r e a c t i v i t y t o w a r d e i t h e r BC1.J o r B F ^ , i t s f a i l u r e t o be p r o t o n a t e d b y HBF^, a n d i t s f a i l u r e t o be q u a t e r n i z e d b y e i t h e r MeSO^F o r E t ^ O B F ^ . I t d o e s h o w e v e r show e v i d e n c e o f a c c e p t o r p r o p e r t i e s b y i t s r e a c t i o n w i t h c e r t a i n t h i o p h i l e s . Numerous a t t e m p t s w e r e made t o p r e p a r e t r a n s i t i o n m e t a l c o m p l e x e s o f P^S^. The f o r m a t i o n o f c o m p l e x e s i s m o s t f a v o u r e d w i t h t h e l a t e r a n d h e a v i e r t r a n s i t i o n m e t a l s i n l o w o x i d a t i o n s t a t e s . I n t h e s e c o m p l e x e s , o p t i m u m d o n o r - a c c e p t o r i n t e r -a c t i o n i s e x p e c t e d a n d r e s u l t s r e v e a l t h a t J ^ S ^ i s a g o o d 7 7 - a c c e p t o r . The i n f r a r e d a nd Raman s p e c t r a o f J ^ S ^ w e r e o b t a i n e d and c o m p l e t e v i b r a t i o n a l a s s i g n m e n t s h a v e b e e n made. The s p e c t r a a r e i n s u b s t a n t i a l a g r e e m e n t w i t h r e c e n t l y p u b -l i s h e d i n f o r m a t i o n b u t t h e r e i s some d i f f e r e n c e i n i n t e r -p r e t a t i o n . T e t r a p h o s p h o r u s t r i s u l p h i d e d i i o d i d e , d - P ^ S ^ I ^ h a s b e e n shown t o b e h a v e c h e m i c a l l y a s l i t t l e more t h a n a m o l e c u l a r a s s o c i a t i o n o f a n d I 2« A t t e m p t s t o p r e p a r e t h e c a t i o n P^S^ w e r e u n s u c c e s s f u l and e x p e r i m e n t s d e s i g n e d t o r e p l a c e i o d i d e b y o t h e r g r o u p s s u c h a s -CN, -SON and -OEt i n v a r i -a b l y r e s u l t e d i n l o s s o f m o l e c u l a r i o d i n e and r e g e n e r a -t i o n o f J ? 4 S 5 . C o n t i n u i n g e x p e r i m e n t a l d i f f i c u l t i e s w i t h P^S^ a n d i t s c o m p l e x e s b r o u g h t a b o u t a c h a n g e i n t h e d i r e c t i o n o f t h i s r e s e a r c h . I n s t e a d , v a r i o u s c y c l i c o r g a n o p h o s p h o r u s -s u l p h u r compounds w e r e e x a m i n e d c h e m i c a l l y a n d s p e c t r o -s c o p i c a l l y , a m a j o r p o r t i o n o f t h e w o r k i n v o l v i n g t h e i n t e r r e l a t i o n s h i p b e t w e e n t h e compounds P h ^ P ^ S , P h ^ P ^ S ^ an d P h g P g S ^ * A t t h e t i m e t h a t t h i s w o r k was b e g u n , t h e s t r u c t u r e s o f Ph.P.S a n d P h , P , S , w e r e u n c e r t a i n and t h e 4 4 3 3 3 e s t a b l i s h m e n t o f t h e s e s t r u c t u r e s was n a t u r a l l y e s s e n t i a l f o r a n u n d e r s t a n d i n g o f t h e i r c h e m i s t r y . The c r y s t a l s t r u c t u r e o f Ph^P^S h a s b e e n d e t e r m i n e d , and. t h e m o l e c u l e , c o n t r a r y t o l i t e r a t u r e r e p o r t s , c o n s i s t s o f a n o n - p l a n a r f i v e - m e m b e r e d P^S r i n g . The s t r u c t u r e o f P h ^ P ^ S ^ h a s b e e n e l u c i d a t e d by i n t e r p r e t a t i o n o f t h e p h o s p h o r u s a n d f l u o r i n e n.m.r. s p e c t r a o f i t s p a r a - f l u o r o p h e n y l a n a l o g u e . P h ^ P j S ^ c o n s i s t s o f a n u n s y m m e t r i c a l f i v e - m e m b e r e d P 3 S 2 r i n g , a g a i n c o n t r a r y t o l i t e r a t u r e r e p o r t s , t h e r e m a i n i n g s u l p h u r a t o m b e i n g b o n d e d e x o c y c l i c a l l y t o one o f t h e p h o s p h o r u s a t o m s . The m e t a - a n d p a r a - f l u o r o p h e n y l a n a l o g u e s o f t h e compounds P h ^ P ^ S , P h ^ P ^ S j a n d P n 2 P 2 S 4 ' a n d a l s 0 " t * 1 0 8 6 o f - i i i -( P h P ) n and ( P h P I ) 2 , h a v e b e e n p r e p a r e d ; u s i n g t h e m e t h o d s o f T a f t e t a l , i n d u c t i v e and r e s o n a n c e p a r a m e t e r s h a v e b e e n c a l c u l a t e d f r o m t h e n.m.r. s h i f t s . A c c e p t o r p r o p e r t i e s ( b o t h CT- and 77-) a r e g r e a t e s t i n t h o s e compounds r i c h e s t i n s u l p h u r a nd P h g P g S ^ , i n p a r t i c u l a r , e x h i b i t s v e r y l a r g e i n d u c t i v e a nd c o n j u g a t i v e w i t h d r a w a l . The i n f r a r e d a n d Raman s p e c t r a o f t h e p h e n y l a n d j j - f l u o r o p h e n y l d e r i v a t i v e s h a v e b e e n o b t a i n e d a nd a number o f v i b r a t i o n a l a s s i g n m e n t s h a v e b e e n made. The mass s p e c t r a o f t h e p h e n y l a nd £-fluorophenyl d e r i v a t i v e s h a v e b e e n o b t a i n e d , a nd c o n s i d e r a b l e r e a r r a n g e m e n t o f m o l e c u l a r f r a g m e n t s i s a common f e a t u r e . - i v -T ABLE OF CONTENTS PAGE ABSTRACT i TABLE OF CONTENTS i v L I S T OF TABLES v i L I S T OF FIGURES v i i i ACKNOWLEDGEMENTS i x INTRODUCTION 1 PART 1: TETRAPHOSPHORUS T R I S U L P H I D E I . EXPERIMENTAL A. INTRODUCTION 10 B. EXPERIMENTAL D E T A I L 20 C. INFRARED AND RAMAN SPECTRA 54 I I . D I S C U S S I O N 61 PART 2: ORGANOPHOSPHORUS-SULPHUR COMPOUNDS . I . EXPERIMENTAL A. INTRODUCTION 8 1 B. EXPERIMENTAL D E T A I L 87 I I . RESULTS AND D I S C U S S I O N 111 THE DIIODODIPHENYL DIPHOSPHINES 123 ( R 2 P 2 I 2 ) THE FOUR-MEMBERED RING SYSTEM 135 ( R 2 P 2 S 4 ) THE CYCLOTETRAPHOSPHINE MONOSULPHIDES 146 ( V 4 S ) THE CYCLOTRIPHOSPHINE T R I S U L P H I D E S 153 -V-TABLE OF C O N T E N T S ( c o n t . ) PAGE THE FLUOROPHENYL CYCLOPOLYPHOSPHINES 163 ( F C 6 H 4 P ) n . ELECTRONIC INTERACTIONS OF THE FLUOROPHENYL D E R I V A T I V E S 1 6 5 SUMMARY 180 REFERENCES 183 - v i -L I S T OF TABLES TABLE T I T L E PAGE I V i b r a t i o n a l s p e c t r a o f P^S^ 57 I I S h i e l d i n g p a r a m e t e r s a n d T a f t i n d u c t i v e a n d r e s o n a n c e p a r a m e t e r s o f compounds p r e p a r e d i n t h i s w o r k 113 I I I M a s s s p e c t r a o f P h , , P 2 I 2 and ( p _ - F C 6 H 4 P I ) 2 124 I V C h a r a c t e r i s t i c i n f r a r e d f r e q u e n c i e s o f p h e n y l a n d f l u o r o p h e n y l g r o u p s 116 V Low f r e q u e n c y i n f r a r e d a n d Raman a b s o r p t i o n o f compounds R ^ ^ ^ 127 V I Raman s p e c t r a l r e s u l t s f o r PhPR" 2, P h P C l 2 , m-FCgH^PHg and ( m - F C g H ^ P I ) 2 i n s o l u t i o n ' 120 V I I M ass s p e c t r a o f M e ^ S ^ , P h ^ S ^ and ( p _ - F C 6 H 4 P S 2 ) 2 136 V I I I S o l i d s t a t e Raman s p e c t r a o f compounds R 2 P 2 S 4 138 I X S o l i d s t a t e i n f r a r e d s p e c t r a o f compounds R 2 P 2 S 4 140 X M o l e c u l a r s t r u c t u r e o f Ph^P^S 148 X I M a s s s p e c t r a l r e s u l t s f o r Ph^P^S and ( p _ - F C 6 H 4 P ) 4 S 150 - v i i -T ABLE X I I X I I I X I V XV X V I L I S T OF T A B L E S ( c o n t . ) T I T L E PAGE V i b r a t i o n a l s p e c t r a o f Ph^P^S and ( J J - F C 6 H 4 P ) 4 S 152 M a s s s p e c t r a l r e s u l t s f o r P h ^ P ^ S ^ a n d ( £ - F 0 6 H 4 P S ) 3 155 V i b r a t i o n a l s p e c t r a o f P h ^ P ^ S ^ and i t s f l u o r o p h e n y l a n a l o g u e s 160 M a s s s p e c t r a o f compounds ( j j - F C g H 4 P ) n 164 S h i e l d i n g p a r a m e t e r s a nd T a f t i n d u c t i v e a n d r e s o n a n c e p a r a m e t e r s o f compounds r e f e r r e d t o i n t h e d i s c u s s i o n 166 X V I I E f f e c t o f f l u o r i n e i n t h e p a r a -p o s i t i o n o n v a r i o u s i n f r a r e d s t r e t c h i n g f r e q u e n c i e s 1 7 1 - v i i i -LIST OF FIGURES TITLE E.s.r. e l e c t r o l y s i s c e l l Orientation of p - o r b i t a l s as used i n the c a l c u l a t i o n Energy l e v e l s of P^^ a s derived by HMO ca l c u l a t i o n s Reactions of organophosphorus sulphur r i n g compounds Vibrations of a monosubstituted phenyl group Molecular structure of Ph^P^S Arrangement of phenyl groups i n Ph.P.S 4 4 19 F n.m.r. spectrum of ( £-FC 6H 4PS) 3 "51 P n.m.r. spectrum of (p-FC 6H 4PS) 3 ACKNOWLEDGEMENTS I w o u l d l i k e t o t h a n k P r o f . N. L. P a d d o c k f o r h i s h e l p and e n c o u r a g e m e n t d u r i n g t h e c o u r s e o f t h i s w o r k a nd a l s o f o r t h e v e r y s t i m u l a t i n g d i s c u s s i o n s w h i c h w e r e s o i n v a l u a b l e . The v a r i o u s members o f t h i s r e s e a r c h g r o u p h a v e c o n t r i b u t e d g r e a t l y t o t h e c o m p l e t i o n o f t h i s w o r k a n d and t o a l l o f them I e x p r e s s my g r a t i t u d e , e s p e c i a l l y t o D r . H. P. C a l h o u n f o r t h e s t r u c t u r e d e t e r m i n a t i o n o f P h . P . S . I w o u l d a l s o l i k e t o t h a n k t h e t e c h n i c a l 4 4 s t a f f o f t h e C h e m i s t r y D e p a r t m e n t f o r t h e i r a s s i s t a n c e a n d M r . P. B o r d a , i n p a r t i c u l a r , h a s b e e n v e r y h e l p f u l . L a s t , b u t n o t l e a s t , I w o u l d l i k e t o e x p r e s s my t h a n k s t o M r s . F a i t h H u n t e r f o r h e r d i l i g e n c e i n t y p i n g t h i s t h e s i s a n d t o my f a m i l y a n d f r i e n d s f o r t h e i r s u p p o r t a n d e n c o u r a g e m e n t . - 1 -INTRODUCTION The r e a c t i o n b e t w e e n t h e e l e m e n t s p h o s p h o r u s a n d s u l p h u r was f i r s t n o t e d b y M a r g r a f f i n 1 7 4 0 . I n t h e f o l l o w i n g one h u n d r e d a n d f i f t y y e a r s , c h e m i c a l i n d i v i d -u a l i t y was c l a i m e d f o r more t h a n a d o z e n p h o s p h o r u s -s u l p h u r c o m p o s i t i o n s r a n g i n g f r o m P ^ S t o p 2 S i 2 * M a n v °^ t h e s e s o - c a l l e d compounds w e r e p r e p a r e d s i m p l y b y v a r y i n g t h e P / S r a t i o s o t h a t u n d o u b t e d l y t h e r e w e r e m i x t u r e s o f p h o s p h o r u s s u l p h i d e s p r e s e n t . I t was n o t u n t i l t h e b e g i n n i n g o f t h e t w e n t i e t h c e n t u r y t h a t t h e c a r e f u l w o r k ?_4. o f A l f r e d S t o c k a n d h i s c o - w o r k e r s ^ r e s u l t e d i n t h e k n o w l e d g e t h a t o n l y t h r e e compounds, t e t r a p h o s p h o r u s t r i s u l p h i d e ( P ^ S ^ ) , t e t r a p h o s p h o r u s h e p t a s u l p h i d e ( P ^ S ^ ) a n d t e t r a p h o s p h o r u s d e c a s u l p h i d e ( P ^ S I Q ) c o u 1 ^ "be made b y t h e t h e r m a l r e a c t i o n o f p h o s p h o r u s w i t h s u l p h u r . S i n c e t h a t t i m e , t h e e x i s t e n c e o f s e v e r a l o t h e r p h o s p h o r u s s u l p h i d e s o f l o w e r t h e r m a l s t a b i l i t y h a s b e e n r e c o g n i z e d . T e t r a p h o s p h o r u s p e n t a s u l p h i d e ( P ^ S ^ ) c a n n o t be made b y d i r e c t u n i o n o f t h e e l e m e n t s , a n d i s b e s t p r e p a r e d p h o t o -P i c h e m i c a l l y b y e x p o s i n g a c a r b o n d i s u l p h i d e s o l u t i o n o f s t o i c h i o m e t r i c q u a n t i t i e s o f P ^ S ^ a n d s u l p h u r , p l u s a t r a c e o f i o d i n e , t o d i f f u s e d a y l i g h t f o r s e v e r a l d a y s . R e c e n t l y , t e t r a p h o s p h o r u s n o n a s u l p h i d e ( P ^ S ^ ) h a s b e e n p r e p a r e d ^ b y t h e h y d r o l y s i s o f t h i o p h o s p h o r y l c h l o r i d e i n s e a l e d t u b e s . I n a d d i t i o n , a b r i e f c o m m u n i c a t i o n h a s c l a i m e d t h e e x i s t e n c e o f P ^ S g , f o r m e d f r o m t h e r e a c t i o n o f P^S -x w i t h w h i t e p h o s p h o r u s ? h o w e v e r , i n v i e w o f t h e - 2 -p a s t h i s t o r y o f e r r o r s i n P-S c h e m i s t r y , i t w o u l d be p r u d e n t t o c o n s i d e r t h e e x i s t e n c e o f P 4 S 2 a s u n c e r t a i n . A p h o s -p h o r u s s u l p h i d e o f n o n - s t o i c h i o m e t r i c c o m p o s i t i o n was n o t e d b y R o d l e y a n d W i l k i n s i n t h e i r w o r k o n p h o s p h o r u s - s u l p h u r c o m p o s i t i o n s i n t h e r a n g e P^S^ t o P^Sg g. A p a r t i c u l a r p h a s e o b s e r v e d b y t h e s e w o r k e r s , o f a p p r o x i m a t e c o m p o s i t i o n fl P^Sg ^, was l a t e r shown b y X - r a y d i f f r a c t i o n t o p o s s e s s t h e same b a s i c s t r u c t u r e a s P^S^, e x c e p t t h a t some t e r m -i n a l s u l p h u r a t o m s w e r e m i s s i n g . I t d o e s n o t seem u n l i k e l y c o n s i d e r i n g t h e s e r e s u l t s , t h a t a d d i t i o n a l p h o s p h o r u s s u l p h i d e s w i l l be p r e p a r e d i n t h e f u t u r e . The c r y s t a l s t r u c t u r e s o f P ^ 5 5 , P ^ 1 0 , P 4 S g 1 1 a n d 1 2 P^S-,^ h a v e b e e n r e p o r t e d a n d t h e m o l e c u l a r s t r u c t u r e s o f P ^ S ^ , P ^ S ^ a n d P ^ S ^ a r e r e p r o d u c e d b e l o w . The m o l e -c u l a r s t r u c t u r e o f P ^ J S ^ Q * l i k e t h a t o f P ^ O ^ Q ' P O S S E S S E S t e t r a h e d r a l s y m m e t r y , e a c h p h o s p h o r u s a t o m b e i n g - 3 -p e n t a v a l e n t a n d t e t r a c o o r d i n a t e ; t h e s t r u c t u r e o f P ^ S g i s s i m i l a r t o t h a t o f P ^ ^ Q w i - t h " t h e e x c e p t i o n t h a t a t e r m i -n a l s u l p h u r a t o m i s m i s s i n g . The s t r u c t u r e s o f t h e p h o s -p h o r u s s u l p h i d e s a r e q u i t e d i s t i n c t i v e i n t h a t t h e y a r e "based o n t h e c a g e - l i k e t e t r a h e d r a l s t r u c t u r e o f P ^ , a n d l i k e P ^ i t s e l f , c o n t a i n many s m a l l r i n g s a n d b o n d a n g l e s . I n d e e d , t h e s t r u c t u r e o f P ^ S ^ a s i l l u s t r a t e d a b o v e was OO c o n s i d e r e d u n l i k e l y a s r e c e n t l y a s 1949 o n t h e b a s i s t h a t i t d i d n o t p o s s e s s t h e l e a s t s t r a i n e d s t r u c t u r e t h a t c o u l d be d e v i s e d f r o m f o u r p h o s p h o r u s a t o m s a n d t h r e e s u l p h u r a t o m s . The c o m p l e t e l y u n s y m m e t r i c a l s t r u c t u r e o f P ^ S ^ i s s u r e l y t h e m o s t u n u s u a l o f a l l t h e p h o s p h o r u s s u l p h i d e s t r u c t u r e s i n t h a t i t c o n t a i n s a f o u r - m e m b e r e d r i n g , two f i v e - m e m b e r e d r i n g s a n d a s i x - m e m b e r e d r i n g . E v e n i n P 4 S 7 , n o t a l l t h e P - P b o n d s h a v e b e e n b r o k e n b y b r i d g i n g s u l p h u r a t o m s , a n d t h e s o l i t a r y P - P b o n d i n P4S7 i s c o n s i d e r a b l y l o n g e r ( 2 . 3 5 A 0 ) t h a n a n o r m a l P - P b o n d l e n g t h ( 2 . 2 2 A 0 ) ; i n a d d i t i o n , t h e r e a r e e i g h t d i f f e r e n t t y p e s o f b o n d a n g l e i n P 4 S 7 . A l t h o u g h t h e s t r u c t u r e s o f t h e more common p h o s p h o r u s s u l p h i d e s h a v e b e e n known f o r some t i m e now, t h e c h e m i s t r y o f t h i s f a m i l y h a s r e m a i n e d c o m p a r a t i v e l y u n d e v e l o p e d . I t w o u l d n o t be a n u n d e r -s t a t e m e n t t o s a y t h a t , d e s p i t e t h e i r u n u s u a l s t r u c t u r e s , l i t t l e r e s e a r c h h a s b e e n c a r r i e d o u t w i t h t h e p h o s p h o r u s s u l p h i d e s a n d n o t much i s u n d e r s t o o d a b o u t t h e i r b o n d i n g a n d r e a c t i v i t y . - 4 -The phosphorus s u l p h i d e s have been used e x t e n s i v e l y f o r i n d u s t r i a l purposes f o r q u i t e some time, and although the commercial importance of these compounds should not be underestimated, t h e i r i n d u s t r i a l uses have not con-t r i b u t e d much t o an understanding of t h e i r s t r u c t u r e s or r e a c t i o n s . Thus, P^S^ has l o n g been used i n the manu-f a c t u r e of o r d i n a r y "strike-anywhere" matches i n which i t repl a c e d the more dangerous white phosphorus t h a t was fo r m e r l y used. There e x i s t s a l a r g e number of patents i n the l i t e r a t u r e r e l a t i n g to the use of phosphorus s u l p h i d e s i n the p r e p a r a t i o n of l u b r i c a n t o i l a d d i t i v e s and f l o t a t i o n reagents. Halogenated p a r a f f i n s and phos-phorus s u l p h i d e s , i n the presence of a P r i e d e l - C r a f t s c a t a l y s t at elevated temperatures, g i v e P- and S- con-t a i n i n g organic compounds which are u s e f u l as o i l a d d i t i o n agents because they possess a n t i - o x i d a n t p r o p e r t i e s and i n h i b i t c o r r o s i o n . U s e f u l l u b r i c a t i n g o i l a d d i t i v e s are a l s o obtained from the r e a c t i o n of P^S^ w i t h organic compounds such as e s t e r s , a l c o h o l s and o l e f i n i c hydro-carbons 1^"; i t has a l s o been shown1-' tha t the number and s e v e r i t y of surf a c e i g n i t i o n s i n i n t e r n a l combustion engines i s reduced by the a d d i t i o n of s m a l l q u a n t i t i e s of phosphorus-sulphur compounds t o automotive g a s o l i n e s . Phosphorus s u l p h i d e s have a l s o been used e x t e n s i v e l y i n 16 the manufacture of i n s e c t i c i d e s . Compounds r e f e r r e d t o as t r i d i a l k y l phospho thiophosphates are produced by he a t i n g together P A S 1 0 and a l k y l phosphates; compounds of - 5 -t h i s t y p e w i t h l o w e r a l k y l g r o u p s s u c h a s m e t h y l a n d e t h y l h a v e a q u i c k i n s e c t i c i d a l a c t i o n , h u t t h e h i g h e r a l k y l d e r i v a t i v e s r e t a i n t h e i r t o x i c i t y l o n g e r a n d a r e more r e s i s t a n t t o h y d r o l y s i s . C o n c e n t r a t i o n s a s l o w a s 1:2,000 p a r t s o f w a t e r a r e e f f e c t i v e a g a i n s t r o a c h e s , a p h i d s , s p i d e r s a n d f l i e s . The p o s s i b i l i t y o f u s i n g P^S^ a s a 17 c o o l a n t f o r n u c l e a r r e a c t o r s h a s b e e n i n v e s t i g a t e d S t u d i e s w e r e made t o d e t e r m i n e t h e c o r r o s i o n a n d h e a t t r a n s f e r c h a r a c t e r i s t i c s o f P^S^ a t 1200°F a n d t h e r e b y d e t e r m i n e t h e f e a s i b i l i t y o f e x t r a c t i n g e n e r g y f r o m a n u c l e a r r e a c t o r u s i n g a b o i l i n g P^S^ c y c l e . R e s u l t s showed t h a t P.S-. was b e t t e r s u i t e d a s a c o o l a n t t h a n was 4 3 m o l t e n s u l p h u r , w h i c h p r o v e d t o be more c o r r o s i v e a n d l e s s e f f i c i e n t a s a c o o l a n t . Some o f t h e b e t t e r c h a r a c t e r i z e d r e a c t i o n s o f t h e 18 22 p h o s p h o r u s s u l p h i d e s h a v e b e e n r e v i e w e d p r e v i o u s l y ' . The m a j o r i t y o f t h e r e a c t i o n s i n v o l v e n u c l e o p h i l i c a t t a c k a n d d e s t r u c t i o n o f t h e c a g e s t r u c t u r e s ; t h u s , P ^ S ^ , P ^ S ^ 24 and P ^ S ^ Q h a v e b e e n f o u n d t o r e a c t w i t h G r i g n a r d r e a g e n t s , P 4 S 1 ( ) m& > a c i d h y d r o l y s i s , 4 R P ( s ) ( S H ) ( 0 H ) Compounds w i t h X-H b o n d s (X=0,S,N) r e a c t w i t h P^S^^Q b y e l i m i n a t i o n o f R^S. A l c o h o l s a n d p h e n o l s g i v e p r e -19 20 39 d o m i n a n t l y s e c o n d a r y d i t h i o p h o s p h a t e s ' ' . P 4 S 1 0 + 8 R 0 H > 4 ( R 0 ) 2 P ( S ) S H +2H 2S P 4 S 1 0 i s u s e d e x t e n s i v e l y i n o r g a n i c c h e m i s t r y f o r c o n -- 6 -v e r t i n g C=0, COOH and P=0 i n t o t h e i r corresponding sulphur analogues. Alcohols also react with P^S^ and P^S^ to give p r o d u c t s 4 0 of composition (R0) 2PSH, (R0) 2P(S)SH and (R0) 2P(3)3R. The phosphorus sulphides react v/ith amines 25 43 45 and also with l i q u i d ammonia, ' * the usual r e s u l t being a cleavage of the P-S-P bridges. The phosphorus sulphides range i n h y d r o l y t i c s t a b i l i t y from P^S^, which reacts only slowly with cold d i l u t e HCl or HjSO^, to P^S^ which i s hydrolyzed by atmospheric moisture. The 21 sequence of h y d r o l y t i c s t a b i l i t y appears " to be P^S^>P4S10 ^  P4S7• A l l the phosphorus sulphides are hydro-lyzed by aqueous a l k a l i s to give products which include hydrogen, hydrogen sulphide, phosphine, hypophosphorous 21 acid, phosphorous acid and phosphoric acid 41,42 The r e a c t i o n of P^S^ with iodine i s quite complex. 21 V/ith an excess of iodine, P.S^ i s oxidized to P.S^. Under 4 3 4 7 milder conditions, s t o i c h i o m e t r i c amounts of iodine and P^S^ can react to p roduced- or ^ - P ^ S ^ I j . The CL-isomer^ i s the more stable of these two forms; indeed, - 7 -t h e e x i s t e n c e o f / ^ - P ^ S ^ g h a s o n l y r e c e n t l y b e e n e s t a b -l i s h e d ^ 2 . / ^ - P ^ S j I , , c a n be c o n v e r t e d t o a - P ^ S j I , , b y i n -v e r s i o n o f a n S - P - I g r o u p , t h e t r a n s f o r m a t i o n r e a d i l y o c c u r r i n g when / 3 - P ^ S ^ I 2 i s m e l t e d . T h e s e r e a c t i o n s c on-s t i t u t e a n e x c e l l e n t e x a m p l e o f t h e g e n e r a l m o b i l i t y o f b o n d i n g i n t h e p h o s p h o r u s s u l p h i d e s . A t t h e t i m e t h a t t h i s w o r k was u n d e r t a k e n , o n l y one r e p o r t h a d a p p e a r e d i n t h e l i t e r a t u r e r e g a r d i n g c o m p l e x 29 f o r m a t i o n w i t h t h e p h o s p h o r u s s u l p h i d e s . N i x o n e t a l . h a v e p r e p a r e d t h e c o m p l e x e s c i s - C P ^ S ^ ) 2 M ( C O ) ^ M=Cr,Mo,W , c i s - ( P 4 S 3 ) 3 M ( C O ) 3 JM=Cr,Mo a n d N i ( P 4 S 3 ) 4 a n d h a v e shown t h a t ? 4 S 3 c o o r d i n a t e s t h r o u g h i t s u n i q u e a p i c a l p h o s p h o r u s . I n t h e i n t e r v e n i n g y e a r s , o n l y a f e w a d d i t i o n a l p a p e r s h a v e a p p e a r e d and t h e s e w i l l be r e -f e r r e d t o l a t e r i n t h i s t h e s i s . One o f t h e m a j o r a i m s o f t h i s w o r k h a s b e e n t o i n -v e s t i g a t e t h e d o n o r - a c c e p t o r p r o p e r t i e s o f p h o s p h o r u s -s u l p h u r compounds l n t h e h o p e s o f o b t a i n i n g more k n o w l e d g e o f t h e f a c t o r s i m p o r t a n t i n t h e i r b o n d i n g . The l o w e s t s u l p h i d e , was e x a m i n e d e x t e n s i v e l y i n t h i s r e g a r d b e c a u s e i t i s t h e m o s t s t a b l e a n d m o s t t r a c t a b l e o f t h e s e c a g e m o l e c u l e s . H o w e v e r , c o n t i n u i n g e x p e r i m e n t a l d i f f i -c u l t i e s f o r c e d a c h a n g e i n t h e d i r e c t i o n o f t h i s r e s e a r c h , a n d i n s t e a d o f p u r s u i n g w o r k w i t h t h e c a g e p h o s p h o r u s s u l p h i d e s , v a r i o u s c y c l i c o r g a n o p h o s p h o r u s - s u l p h u r compounds w e r e e x a m i n e d i n s t e a d . C h i e f a m o n g s t t h e s e w e r e t h e compounds P h ^ P ^ S , P h ^ P ^ S ^ a n d P h ^ S ^ , a l l o f w h i c h c a n be p r e p a r e d b y t h e r e a c t i o n o f p h e n y l p h o s p h i n e w i t h s u l p h u r . A t t h e t i m e t h a t t h i s w o r k was u n d e r t a k e n , t h e s t r u c t u r e s o f t h e f i r s t two h a d n o t b e e n c o n c l u s i v e l y e s t a b l i s h e d a n d i t was, o f c o u r s e , n e c e s s a r y t o e s t a b l i s h t h e s e s t r u c t u r e s b e y o n d a n y d o u b t . On t h e o t h e r h a n d , t h e s t r u c t u r e o f t h e t h i r d compound h a s b e e n shown t o c o n s i s t o f a f o u r - m e m b e r e d p l a n a r ? 2 S 2 r i n & » w i t h e a c h p h o s p h o r u s a t o m b e i n g p e n t a v a l e n t a n d t e t r a c o o r d i n a t e . 121 F o r e x a m p l e , t h e s t r u c t u r e o f M e 0 P 0 S . i s shown b e l o w . The r e a c t i o n s o f compounds o f t h i s t y p e h a v e b e e n e x a m i n e d i n d e t a i l ^ a n d r i n g c l e a v a g e i s t h e u s u a l r e s u l t . B o n d m o b i l i t y i s a common f e a t u r e o f t h e c a g e p h o s -p h o r u s s u l p h i d e s a n d s o e x p e r i m e n t s w e r e u n d e r t a k e n t o d e t e r m i n e w h e t h e r t h e r i n g a n a l o g u e s a r e c a p a b l e o f s i m i l a r b e h a v i o u r . W h e r e a s some i n s i g h t i n t o t h e e l e c -t r o n i c i n t e r a c t i o n s i n P^S^ h a s b e e n g l e a n e d b y a n exam-i n a t i o n o f i t s b a s i c g e n e r a l c h e m i s t r y , d o n o r - a c c e p t o r - 9 -i n t e r a c t i o n s w i t h i n t h e p h o s p h o r u s - s u l p h u r r i n g compounds h a v e b e e n a s s e s s e d b y i n t e r p r e t a t i o n o f t h e i r m- a n d p_-f l u o r o p h e n y l d e r i v a t i v e s . F i n a l l y , e v i d e n c e i s p r e s e n t e d t o show s i m i l a r i t i e s b e t w e e n t h e c a g e p h o s p h o r u s s u l p h i d e s a n d t h e P-S r i n g compounds. I n t h e f o l l o w i n g c h a p t e r s , e x p e r i m e n t s u n d e r t a k e n w i t h P^S^ w i l l be d e s c r i b e d , a n d t h e n a d i s c u s s i o n o f t h e i r r e s u l t s w i l l be p r e s e n t e d ; t h e s e c o n d h a l f o f t h i s t h e s i s w i l l d e a l a n a l o g o u s l y w i t h t h e P-S r i n g s y s t e m s . - 1 0 -PART 1; TETRAPHOSPHORUS T R I S U L P H I D E  I - EXPERIMENTAL A. INTRODUCTION Much o f t h e r e p o r t e d w o r k on t e t r a p h o s p h o r u s t r i s u l p h i d e ( P ^ S j ) h a s i n v o l v e d r e a c t i o n s i n w h i c h t h e c a g e s t r u c t u r e o f P^S^ h a s "been d e s t r o y e d . T y p i c a l r e a c t i o n s o f t h i s t y p e 21 21 22 23 i n c l u d e a c i d a n d b a s i c h y d r o l y s i s ' ' , a s w e l l a s r e a c t i o n s w i t h G r i g n a r d r e a g e n t s 2 ^ a n d w i t h a m i n e s 2 " ' . The c u r i o u s s t r u c t u r e s o f t h e p h o s p h o r u s s u l p h i d e s a r e p e r h a p s t h e i r m o s t i n t e r e s t i n g f e a t u r e h o w e v e r a n d t h i s w o r k was m o s t l y c o n c e r n e d i n p u r s u i n g r e a c t i o n s i n w h i c h t h e c a g e o f P^S^ r e m a i n e d i n t a c t . C o n s e q u e n t l y , i f i t became a p p a r e n t d u r i n g t h e w o r k - u p o f a r e a c t i o n t h a t d e c o m p o s i t i o n o f t h e c a g e h a d o c c u r r e d , t h e n t h e r e a c t i o n m i x t u r e was d i s c a r d e d a f t e r m i n i m a l a t t e m p t s t o i d e n t i f y t h e d ecompo-s i t i o n p r o d u c t s . The f i r s t s e q u e n c e o f e x p e r i m e n t s p r e s e n t e d was d e s i g n e d t o t e s t t h e b a s i c i t y o f P^S^. A f r e s h l y - p r e p a r e d s a t u r a t e d s o l u t i o n o f B F ^ i n ^ 0 was a d d e d t o P ^ ^ J n 0 v i s i b l e r e a c t i o n o r d i s s o l u t i o n o f P^S^ o c c u r r e d o y e r a n umber o f d a y s . The s t r o n g e r b u t s i m i l a r l y n o n - o x i d i z i n g a c i d HBF^ was a l s o t e s t e d w i t h P^S ^ J a g a i n no v i s i b l e d i s s o l u t i o n o r r e a c t i o n o c c u r r e d , e v e n o v e r a number o f d a y s . W i t h 100% s u l p h u r i c a c i d , no i m m e d i a t e r e a c t i o n - 1 1 -o c c u r r e d , b u t o v e r a p e r i o d o f a week t h e y e l l o w c r y s t a l s o f P^S^ s l o w l y d i s a p p e a r e d a n d s i m u l t a n e o u s l y t h e r e a p p e a r e d a s m a l l amount o f w h i t i s h c r y s t a l l i n e m a t e r i a l w h i c h was i d e n t i f i e d a s e l e m e n t a l s u l p h u r . The a d d i t i o n o f P^S^ t o o l e u m (20%. SC>5. i n HgSO^) r e s u l t e d i n a n i m m e d i a t e v i g o r o u s r e a c t i o n . The p u n g e n t s m e l l o f - SO2 was d e t e c t e d a n d t h e s o l u t i o n o f o l e u m t u r n e d a v a r i e t y o f c o l o u r s a n d t h e n r e m a i n e d b l u e , i n d i c a t i n g t h e p r o b a b l e p r e s e n c e o f p, ... Sg . I t i s e v i d e n t t h a t P^S^ i s r e a d i l y o x i d i z e d b y SO^. When f l u o r o s u l p h u r i c a c i d was d i s t i l l e d o n t o P^S^, a v i g o r o u s r e a c t i o n s e t i n f o l l o w i n g a b r i e f i n d u c t i o n p e r i o d ; e l e m e n t a l s u l p h u r was a g a i n i s o l a t e d f r o m t h e r e a c t i o n m i x t u r e . I t i s a p p a r e n t t h e n t h a t P^S^ i s a t m o s t v e r y w e a k l y b a e i c ; i t i s n o t p r o t o n a t e d b y s t r o n g n o n -i x i d i z i n g a c i d s a n d i s d e c o m p o s e d b y o x i d i z i n g a c i d s . To t e s t f u r t h e r t h e p o s s i b l e d o n o r p r o p e r t i e s o f P^S^, t h e m o l e c u l e was t r e a t e d w i t h B P ^ a n d t h e n w i t h B G l j . I n e a c h c a s e , t h e r e was no r e a c t i o n . Many t r i v a l e n t p h o s p h o r u s compounds c a n be q u a t e r n i z e d w i t h r e l a t i v e e a s e b u t a t t e m p t s t o q u a t e r n i z e P^S^ y i e l d e d r e s u l t s s i m i l a r t o t h o s e o b t a i n e d f r o m t h e p r o t o n a t i o n e x p e r i m e n t s . The v e r y s t r o n g m e t h y l a t i n g a g e n t m e t h y l f l u o r o s u l p h a t e , K e S 0 ^ F , s l o w l y r e a c t e d w i t h P^S^ b u t a n a l y t i c a l a n d s p e c t r o s c o p i c d a t a o f t h e p r o d u c t r e v e a l e d t h a t d e c o m p o s i t i o n h a d o c c u r r e d . T r i e t h y l o x o n i u m t e t r a f l u o r o b o r a t e a n d P^S^ p r o d u c e no r e a c t i o n when h e a t e d u n d e r r e f l u x i n m e t h y l e n e c h l o r i d e . The l a c k o f r e a c t i o n w i t h t h e s e s t r o n g a l k y l a t i n g a g e n t s i s f u r t h e r e v i d e n c e o f t h e weak d o n o r p r o p e r t i e s o f P^S,. The f o l l o w i n g s e q u e n c e o f r e a c t i o n s was d e s i g n e d t o t e s t t h e s t a b i l i t y o f t h e c a g e o f P^S^ t o w a r d a v a r i e t y o f o x i d a n t s . I n p a r t i c u l a r i t was o f i n t e r e s t t o s e e i f a r a d i c a l c a t i o n o f P^S^ c o u l d be p r o d u c e d . - I f a r a d i c a l c o u l d be f o r m e d , t h e n e l e c t r o n s p i n r e s o n a n c e m e a s u r e m e n t s w o u l d be e x p e c t e d t o y i e l d u s e f u l i n f o r m a t i o n r e g a r d i n g t h e p o s s i b l e m o b i l i t y o f a n u n p a i r e d e l e c t r o n . The h e x a -c h l o r o a n t i m o n a t e i o n , S b C l g , h a s b e e n shown t o be a o n e -e l e c t r o n o x i d a n t w i t h r e s p e c t t o a r o m a t i c a m i n e s , f e r r o c e n e a n d i o d i d e i o n . H o w e v e r , t r i p h e n y l m e t h y l h e x a c h l o r o -a n t i r a o n a t e a n d P^S^, h e a t e d u n d e r r e f l u x i n C H ^ C ^ , f a i l e d t o r e a o t . A n t i m o n y p e n t a c h l o r i d e i t s e l f h a s become a u s e f u l r e a g e n t f o r t h e g e n e r a t i o n o f c a t i o n r a d i c a l s f r o m p o l y n u c l e a r a r o m a t i c m o l e c u l e s ' . T r e a t m e n t o f P^S^ w i t h SbClcj e i t h e r a s a n e a t l i q u i d o r i n s o l u t i o n , r e s u l t s i n d e c o m p o s i t i o n o f t h e c a g e . The r e a c t i o n p r o d u c t s a r e e l e m e n t a l s u l p h u r a n d w h a t a p p e a r s t o be P C l ^ S b C l g . I n v i e w o f t h i s r e s u l t , i t i s n o t s u r p r i s i n g t h a t a n t i m o n y p e n t a f l u o r i d e i s f o u n d t o r e a c t v i o l e n t l y w i t h P^S^. S u l p h u r c a t i o n s a n d S b 2 S 3 a r e a p p a r e n t l y f o r m e d a s p a r t o f t h e d e c o m p o s i t i o n p r o d u c t s . The r e a c t i o n o f P^S^ w i t h A s F ^ p r o c e e d e d a l o n g s i m i l a r l i n e s . When A s F ^ was c o n d e n s e d o n t o P^S^, f u m i n g a n d f r o t h i n g o c c u r r e d a n d t h e - 1 3 -v a r i e t y o f c o l o u r c h a n g e s o b s e r v e d a r e a t t r i b u t e d t o f o r m a t i o n o f s u l p h u r c a t i o n s . When t h e u n r e a c t e d A s P ^ was r e m o v e d f r o m t h e r e a c t i o n f l a s k , i t was f o u n d t h a t t h e w e i g h t o f t h e p r o d u c t was l e s s t h a n t h e o r i g i n a l w e i g h t o f P^S^ i n d i c a t i n g t h a t v o l a t i l e p r o d u c t s h a d b e e n f o r m e d . P^S^ r e a c t s v i g o r o u s l y w i t h l i q u i d d i n i t r o g e n t e t r o x i d e a t room t e m p e r a t u r e and e l e m e n t a l s u l p h u r c a n be i s o l a t e d . D i m e t h y l s u l p h o x i d e , a v e r y weak o x i d i z i n g a g e n t , w i l l a l s o d e s t r o y P^S^ a n d a g a i n t h e f o r m a t i o n o f s u l p h u r i s o b s e r v e d . The s t a b i l i t y o f P^S^ t o w a r d r e d u c t i o n was e x a m i n e d p o l a r o g r a p h i c a l l y . ? 4 . S 3 w a s f o u n d t o u n d e r g o i r r e v e r s i b l e r e d u c t i o n a t a v e r y l o w p o t e n t i a l ; t h e r e d u c e d s p e c i e s d i d n o t e x h i b i t a n y e l e c t r o n s p i n r e s o n a n c e s p e c t r u m . I n g e n e r a l t h e p r e c e d i n g r e a c t i o n s s how t h a t t h e c a g e o f P 4 S 3 i s r a t h e r f r a g i l e a nd i n c a p a b l e o f w i t h s t a n d i n g e v e n m o d e r a t e s t r e s s . I n f u r t h e r e x p e r i m e n t s d e s i g n e d t o t e s t t h e s t r e n g t h o f t h e P-S f r a m e w o r k , P^S^ was s u b j e c t e d t o t r e a t m e n t w i t h t h i o p h i l e s o f v a r y i n g s t r e n g t h . S u l p h i t e i o n i s i n c a p a b l e o f r e m o v i n g s u l p h u r f r o m P^S^ u n d e r t h e c o n d i t i o n s u s e d ; c y a n i d e i o n w i l l r e a c t t o a l i m i t e d d e g r e e t o f o r m SON" u n d e r s i m i l a r c o n d i t i o n s . T r i p h e n y l p h o s p h i n e i n b o i l i n g CS^ o r b e n z e n e d o e s n o t r e a c t w i t h P^S^; i n b o i l i n g t o l u e n e t h e r e i s a s l i g h t r e a c t i o n , a n d i n b o i l i n g x y l e n e a s i g n i f i c a n t r e a c t i o n , w i t h f o r m a t i o n o f - 1 4 -t r i p h e n y l p h o s p h i n e s u l p h i d e a n d a n i n s o l u b l e s c a r l e t m a t e r i a l . A n a l y t i c a l d a t a show t h a t t h i s m a t e r i a l i s o f v a r i a b l e c o m p o s i t i o n b u t c o n s i s t s p r e d o m i n a n t l y o f p h o s p h o r u s . I f Ph^P a n d P^S^ a r e m e l t e d t o g e t h e r i n a s e a l e d t u b e , t h e r e a c t i o n t a k e s p l a c e q u i t e r a p i d l y . I t m i g h t be e x p e c t e d , g i v e n t h e a p p a r e n t l y weak d o n o r p r o p e r t i e s o f P^S^, t h a t s t a b l e t r a n s i t i o n m e t a l c o m p l e x e s w o u l d be o b t a i n e d o n l y w i t h d i f f i c u l t y . S u c h was t h e c a s e f o r t h e p a r t i c u l a r m e t a l s o f t h e f i r s t a n d s e c o n d t r a n s i t i o n s e r i e s t h a t w e r e t e s t e d i n i t i a l l y . T h us b i s ( a c e t y l a c e -t o n a t o ) o x o v a n a d i u m ( I V ) , w h i c h i s known t o f o r m c o m p l e x e s w i t h Ph^PO a n d p y r i d i n e , d o e s n o t c o m b i n e w i t h P^S^ i n r e f l u x i n g b e n z e n e . The r e a c t i o n o f b i s ( t r i p h e n y l p h o s p h i n e ) n i c k e l d i c a r b o n y l w i t h P^S-j l e d t o a v a r i e t y o f p r o d u c t s , 29 a m o n g s t t h e m a b l a c k , a p p a r e n t l y p o l y m e r i c 7 m a t e r i a l a n d t r i p h e n y l p h o s p h i n e s u l p h i d e . The f o r m a t i o n o f t r i p h e n y l -p h o s p h i n e s u l p h i d e i n d i c a t e s t h a t -P^S^ h a s d e c o m p o s e d and s o t h e r e a c t i o n was n o t p u r s u e d . A n t i m o n y t r i c h l o r i d e d i d n o t r e a c t w i t h P^S^ when h e a t e d u n d e r r e f l u x i n C S 2 . When f u s e d t o g e t h e r w i t h P^S^, t h e r e was l i m i t e d d e c o m p o s i t i o n a n d a s m a l l amount o f Sb,,S 3 was i s o l a t e d . The r e a c t i o n s o f P^S^ w i t h l o w v a l e n t m e t a l s i n t h e s e c o n d a n d t h i r d t r a n s i t i o n s e r i e s w e r e somewhat more s u c c e s s f u l b u t i n g e n e r a l t h e p r o d u c t s p r o v e d e x c e e d i n g l y d i f f i c u l t t o c h a r a c t e r i z e ; i n a l l b u t one c a s e t h e p r o d u c t s p r o v e d t o be c o m p l e t e l y i n s o l u b l e i n a l l s o l v e n t s t e s t e d . T h i s l a c k - 1 5 -o f s o l u b i l i t y s e v e r e l y h a m p e r e d e f f o r t s t o p u r i f y a n d c h a r a c t e r i z e t h e c o m p l e x e s a n d was a m a j o r r e a s o n f o r d i s -c o n t i n u i n g w o r k o n P^S^ i n f a v o u r o f t h e more t r a c t a b l e o r g a n o p h o s p h o r u s s u l p h u r c o m pounds. T h u s , a l t h o u g h p a l l a d o u s c h l o r i d e f a i l e d t o r e a c t w i t h P^S^ e i t h e r i n s o l u t i o n o r when f u s e d t o g e t h e r , b i s ( b e n z o n i t r i l e ) p a l l a d i u m d i c h l o r i d e a n d P^S^ r e a c t e d i m m e d i a t e l y t o f o r m a d a r k b r o w n p r e c i p i t a t e . A n i n f r a r e d s p e c t r u m o f t h e s o l i d showed no a b s o r p t i o n due t o C=N s t r e t c h i n g , i n d i c a t i n g t h a t b o t h b e n z o n i t r i l e g r o u p s h a d b e e n d i s p l a c e d . The p r o d u c t was i n s o l u b l e i n a l l s o l v e n t s t e s t e d . S i m i l a r l y , b i s ( b e n z o n i t r i l e ) p l a t i n u m d i c h l o r i d e a n d P ^ S 3 r e a c t t o p r o d u c e a n o r a n g e s o l i d w h i c h i s 30 i n s o l u b l e i n a l l common s o l v e n t s . V a s k a ' s compound , t r a n s - c h l o r o c a r b o n y l b i s ( t r i p h e n y l p h o s p h i n e ) i r i d i u m ( I ) r e a c t s w i t h P^S^ t o y i e l d t h e g r e e n c o m p l e x I r C l 2 ( H ) ( C 0 ) ( P h 3 P ) ( P 4 S 3 ) . E f f o r t s t o r e p l a c e b o t h P h 3 ? m o l e c u l e s w e r e u n s u c c e s s f u l a n d a g a i n o n l y I r C l 2 ( H ) ( C O ) ( P h 3 P ) ( P 4 S 3 ) w a s o b t a i n e d . I t i s somewhat s u r p r i s i n g t h a t t h i s c o m p l e x t o o i s c o m p l e t e l y i n s o l u b l e . I n a n a t t e m p t t o p r e p a r e a s o l u b l e d e r i v a t i v e o f t h i s p r o d u c t , B C 1 3 was b u b b l e d t h r o u g h a s u s p e n s i o n o f I r C l 2 ( H ) ( C O ) ( P h 3 P ) ( P 4 S 3 ) i n b e n z e n e . The c o l o u r o f t h e m i x t u r e s l o w l y c h a n g e d f r o m g r e e n t o o r a n g e , p r e s u m a b l y a s a r e s u l t o f f o r m a t i o n o f a s p e c i e s s u c h a s t h a t v a c u u m - d r y i n g o f t h e o r a n g e s o l i d was s u f f i c i e n t t o I t was f o u n d h o w e v e r - 1 6 -c a u s e i t t o r e v e r t t o t h e o r i g i n a l g r e e n c o m p l e x . A p p a r e n t l y t h e o r a n g e c o m p l e x i s i n e q u i l i b r i u m w i t h f r e e B C l ^ I r C l ( H ) ( C O ) ( P h 3 P ) ( P 4 S 3 ) J + [ S C I " ] < > I r C l 2 ( H ) ( G O ) ( P h 3 P ) ( P 4 S 3 ) + B C 1 3 and so r e m o v a l o f B C 1 3 b y p u m p i n g c a u s e s c o m p l e t e r e v e r s i o n t o t h e i n i t i a l c o m p l e x . An i n f r a r e d s p e c t r u m p r o v e d t h a t t h e g r e e n m a t e r i a l i s o l a t e d was i d e n t i c a l t o t h e s t a r t i n g m a t e r i a l . I t was f e l t t h a t t h e i n s t a b i l i t y o f t h e t e t r a c h l o r o b o r a t e s a l t m i g h t be due i n p a r t t o t h e d i s p a r a t e s i z e s o f a n i o n and c a t i o n . ' C o n s e q u e n t l y e x p e r i m e n t s w i t h l a r g e r a n i o n s w e r e u n d e r t a k e n . H o w e v e r s o d i u m t e t r a p h e n y l b o r a t e f a i l e d t o r e a c t w i t h I r C l 2 ( H ) ( C O ) ( P h 3 ? ) ( ? 4 S 3 ) i n b o i l i n g t e t r a -h y d r o f u r a n ; s i m i l a r l y t h e c h l o r i d e a c c e p t o r s C o C l 2 a n d S n C l 2 f a i l e d t o r e a c t . A l t h o u g h S b C l j . i s a p o w e r f u l c h l o r i d e a c c e p t o r , i t h a s a l s o b e e n shown t o a t t a c k P ^ S 3 and so t h i s r e a c t i o n was n o t a t t e m p t e d . P 4 S 3 w i l l a l s o c o m b i n e w i t h R h C l ( P h 3 P ) 3 > R h B r ( P h 3 P ) 3 and P t ( P h 3 ? ) 4 b u t a g a i n o n l y i n t r a c t a b l e p o w d e r s a r e o b t a i n e d . E x t e n s i v e a n a l y t i c a l d a t a f o r t h e R h C l ( P h 3 P ) 3 - TqSj c o m p l e x g i v e somewhat c u r i o u s r e s u l t s , a n d i n g e n e r a l t h e s e t h r e e c o m p l e x e s r e m a i n r a t h e r i l l - d e f i n e d . The r e a c t i o n o f V^S^ w i t h c _ i s - ( P B u 3 ) 2 P t C l 2 i s v e r y i n t e r e s t i n g . When h e a t e d u n d e r r e f l u x i n b e n z e n e , t h e r e a c t a n t s p r o d u c e a s o l u b l e b r o w n c o m p l e x w h i c h c a n be p r e c i p i t a t e d b y a d d i t i o n o f a l c o h o l o r l i g h t p e t r o l e u m e t h e r . - 1 7 -I n f r a r e d a n d Raman s p e c t r a i n d i c a t e t h e p r e s e n c e o f c o -o r d i n a t e d P^S^, b u t more s i g n i f i c a n t l y , t h e y r e v e a l t h e l a c k o f P t - C l s t r e t c h i n g . T h i s i s c o n f i r m e d b y a n a l y -t i c a l d a t a s h o w i n g t h a t o n l y r e s i d u a l c h l o r i d e i s p r e s e n t . The c a r b o n a n d h y d r o g e n a n a l y s e s a r e i n a g r e e m e n t w i t h t h e f o r m u l a t i o n P t C P B u ^ ) ( P ^ S ^ ) 2 , a c o m p l e x o f p l a t i n u m ( 0 ) . P r e s u m a b l y t h e d i s p l a c e d t r i b u t y l p h o s p h i n e f u n c t i o n s a s a r e d u c i n g a g e n t a n d i s i t s e l f o x i d i z e d t o P B u ^ C l , , . U n f o r t u n a t e l y t h e c o m p l e x c o u l d n o t be c r y s t a l l i z e d a n d p u r i f i c a t i o n was h a m p e r e d b y t h e f a c t t h a t t h e c o m p l e x i s s t r o n g l y a d s o r b e d . b y s u c h u s u a l c o l u m n m a t e r i a l a s f l o r i s i l a n d s i l i c a g e l . D e s p i t e t h e d i f f i c u l t i e s e x p e r i e n c e d w i t h t h e s e G r o u p V I I I m e t a l c o m p l e x e s t h e mere f a c t t h a t c o m p l e x a t i o n h a s o c c u r r e d i s e n c o u r a g i n g ; f u r t h e r m o r e u s e f u l i n f o r m a t i o n h a s b e e n d e r i v e d f r o m t h e C=0 s t r e t c h o f I r C l 2 ( H ) ( C O ) ( P h ^ P ) ( P ^ S 5 ) a n d a l s o f r o m t h e Raman s p e c t r u m o f P t ( P B u ^ ) ( P ^ S ^ ) 2 > T h e s e e x p e r i m e n t s w e r e a m o n g s t t h e l a s t a t t e m p t e d w i t h P^S^ a n d a s s t a t e d p r e v i o u s l y , t h e l a c k o f t r a c t a b i l i t y o f t h e s e , t h e o n l y r e a l l y p r o m i s i n g c o m p l e x e s , r e s u l t e d i n d i s c o n t i n u a t i o n o f w o r k w i t h P^S^ i n f a v o u r o f o r g a n o p h o s p h o r u s s u l p h u r c o m pounds. P^S^ h a s b e e n shown t o r e a c t w i t h i o d i n e t o p r o d u c e two d i f f e r e n t i s o m e r s 5 1 , 5 2 o f P 4 S 5 I 2 . The more s t a b l e i s o m e r , d e n o t e d CL-P^S^I,, was t r e a t e d w i t h s i l v e r h e x a -- 1 8 -f l u o r o a n t i m o n a t e . A n i m m e d i a t e p r e c i p i t a t i o n o f A g l was o b s e r v e d b u t f r o m i t s w e i g h t i t was d e t e r m i n e d t h a t a d d i t i o n a l b y p r o d u c t s w e r e a l s o p r e s e n t . A n o r a n g e w a t e r -i n s o l u b l e p o w d e r b e l i e v e d t o be S b , ^ was a l s o i s o l a t e d , i n d i c a t i n g t h a t d e c o m p o s i t i o n h a d o c c u r r e d . d-P^S^I,,, when m i x e d w i t h s o d i u m t e t r a p h e n y l b o r a t e i n b e n z e n e , g i v e s a w i n e - r e d s o l u t i o n . H o w e v e r , N a B P h ^ was r e c o v e r e d u n c h a n g e d . w a s a l s o r e c o v e r e d a n d t h e r e f o r e t h e w i n e - r e d c o l o u r i s a t t r i b u t e d t o f o r m a t i o n o f m o l e c u l a r i o d i n e . W i t h p o t a s s i u m t h i o c y a n a t e , d - P ^ S ^ ^ a g a i n r e v e r t s t o P^S^ and m o l e c u l a r i o d i n e . P o t a s s i u m c y a n i d e and d - P ^ S ^ I , , r e a c t t o y i e l d a s i m i l a r w i n e - r e d s o l u t i o n . The c o l o u r s l o w l y f a d e d t o a p a l e y e l l o w a n d r e m o v a l o f s o l v e n t g a v e two p r o d u c t s , P^S^ a n d K I . The p o t a s s i u m i o d i d e i s f o r m e d a s l i b e r a t e d m o l e c u l a r i o d i n e o x i d i z e s c y a n i d e i o n , I 2 + 2CN~ > (CN) 2 + 21" T h i s r e a c t i o n a c c o u n t s f o r t h e o b s e r v e d c o l o u r c h a n g e a n d f o r t h e s u b s e q u e n t f o r m a t i o n o f K I . U n d e r t h e a c t i o n o f S b C l c j , d - P ^ S ^ I g a g a i n d e c o m p o s e s t o f o r m -P^S^ a n d I 2 ; i n t h i s c a s e t h e l i b e r a t e d P^S^ i s t h e n d e c o m p o s e d b y S b C l ^ . T r e a t m e n t o f d - P ^ S ^ I g w i t h m e r c u r y r e s u l t e d i n a h e a v y p r e c i p i t a t i o n o f HgS. C o m p l e x f o r m a t i o n w i t h d - P 4 S 5 I 2 was e q u a l l y u n s u c c e s s f u l . W i t h M o ( C O ) 6 , i n s o l u t i o n , d e c o m p o s i t i o n o c c u r e d w i t h t h e f o r m a t i o n o f a b l a c k p o w d e r t h o u g h t t o be e i t h e r m o l y b d e n u m i o d i d e o r s u l p h i d e . When M o ( C 0 ) 6 a n d d - P ^ S ^ I g w e r e m e l t e d t o g e t h e r - 1 9 -o b v i o u s d e c o m p o s i t i o n o c c u r r e d a s i o d i n e s u b l i m e d o u t o f t h e m i x t u r e . W i t h I r C l ( C O ) ( P P h ^ ) 2 > a n o r a n g e i n t r a c t a b l e compound was o b t a i n e d b u t t r i p h e n y l p h o s p h i n e s u l p h i d e was a l s o i s o l a t e d i n d i c a t i n g t h a t a t l e a s t p a r t i a l d e c o m p o -s i t i o n o f CI-P^S^I,, h a d o c c u r r e d . P o l a r o g r a p h i c r e d u c t i o n o f C L - P ^ S ^ I j was u n s u c c e s s f u l a s t h e m o l e c u l e a g a i n d e c o m p o s e d i n t o P^S^ a n d I 2 , a p p a r e n t l y u n d e r t h e i n f l u e n c e o f t h e e l e c t r o l y t e , t e t r a -n - b u t y l a m m o n i u m i o d i d e . The s o l u t i o n t u r n e d b r i g h t o r a n g e i n d i c a t i n g f o r m a t i o n o f t h e t r i i o d i d e i o n and t h e p o l a r o g r a p h i c wave o b s e r v e d a t -0.95 v. was i d e n t i c a l t o t h a t p r e v i o u s l y o b t a i n e d f o r P„S,. - 2 0 -B. EXPERIMENTAL D E T A I L B F 3 * H 2 0 w i t h P 4 S 5 : BP^'HgO was f r e s h l y - p r e p a r e d "by " b u b b l i n g B P ^ t h r o u g h d i s t i l l e d w a t e r f o r a b o u t one a n d one h a l f h o u r s . The v i s c o u s y e l l o w i s h l i q u i d was a d d e d t o P^S^ b u t no r e a c t i o n o r d i s s o l u t i o n o f P^S^ was o b s e r v e d , e v e n u p o n h e a t i n g t h e s o l u t i o n . HBP. s o l u t i o n w i t h P.S,: 4 4 5 B P 3 was b u b b l e d v i g o r o u s l y t h r o u g h a 4 9 % HF a q u e o u s s o l u t i o n f o r a b o u t one h o u r . The r e s u l t i n g c l e a r f u m i n g s o l u t i o n was a d d e d t o P^S^ i n a p o l y e t h y l e n e c o n t a i n e r . A g a i n no v i s i b l e d i s s o l u t i o n o r r e a c t i o n o c c u r r e d e v e n a f t e r a number o f d a y s . 1 0 0 % H 2 S 0 4 w i t h P 4 S 3 : A s m a l l v o l u m e o f 1 0 0 % H 2 S 0 4 was a d d e d t o a s m a l l amount o f P ^ S 3 i n a d r y b o x . No i m m e d i a t e r e a c t i o n o r d i s s o l u t i o n was o b s e r v e d . O v e r a p e r i o d o f a week i t was o b s e r v e d t h a t t h e y e l l o w P ^ S j was s l o w l y d i s a p p e a r i n g a c c o m p a n i e d b y t h e s i m u l t a n e o u s f o r m a t i o n o f s m a l l w h i t i s h c r y s t a l s . T h e s e c r y s t a l s w e r e c o l l e c t e d o n s i n t e r e d g l a s s , w a s h e d w i t h a c e t o n e a n d d r i e d w i t h n i t r o g e n ; a m e l t i n g p o i n t o f 119°C i n d i c a t e d t h a t t h e p r o d u c t was e l e m e n t a l s u l p h u r . Oleum w i t h P^S^: The a d d i t i o n o f P . S , t o c o l d o l e u m r e s u l t s i n a 4 o v i g o r o u s h u t n o t v i o l e n t r e a c t i o n . S u l p h u r d i o x i d e i s a p p a r e n t l y l i b e r a t e d ( d e t e c t e d b y s m e l l ) a n d a b l u e s o l u t i o n e v e n t u a l l y f o r m s . T h i s b l u e c o l o u r i s 2+ a t t r i b u t e d t o t h e f o r m a t i o n o f S Q HSO xP w i t h P.S,: 3 4 3 D o u b l y d i s t i l l e d f l u o r o s u l p h u r i c a c i d was a d d e d t o P^jS^ i n a d r y a t m o s p h e r e . T h e r e was a n i m m e d i a t e e f f e r v e s c e n c e a n d v e r y s h o r t l y t h e r e a f t e r y e l l o w c r y s t a l s b e g a n a p p e a r i n g . T h e s e c r y s t a l s w e r e c o l l e c t e d on s i n t e r e d g l a s s , w a s h e d a n d d r i e d . A m e l t i n g p o i n t o f 119°C i n d i c a t e d t h e f o r m a t i o n o f e l e m e n t a l s u l p h u r . B P w i t h P,S,: 3 4 3 ( i ) i n s o l u t i o n : B P ^ was b u b b l e d t h r o u g h a s o l u t i o n o f P^S^ i n d r y c h l o r o f o r m f o r a p p r o x i m a t e l y one h o u r . A p a r t f r o m some i n i t i a l c l o u d i n e s s b e l i e v e d t o be c a u s e d b y f o r m a t i o n o f a s m a l l amount o f BP^'HgO t h e r e was no o b v i o u s r e a c t i o n . R e m o v a l o f c h l o r o f o r m g a v e o n l y u n r e a c t e d P^S^, m.p. 171-2°C. ( i i ) n e a t : B F ^ was c o n d e n s e d o n t o P^S^ i n a v a c u u m l i n e u n t i l t h e y e l l o w c r y s t a l s w e r e c o m p l e t e l y c o v e r e d b y l i q u i d . No r e a c t i o n was o b s e r v e d a n d t h e m i x t u r e was a l l o w e d t o warm t o room t e m p e r a t u r e . A t t h i s t e m p e r a t u r e , a l l t h e B P , was g a s e o u s . The two compounds w e r e l e f t i n c o n t a c t t o g e t h e r a t r oom t e m p e r a t u r e o v e r n i g h t b u t no r e a c t i o n h a d o c c u r r e d b y t h e f o l l o w i n g m o r n i n g . ( i i i ) i n a n a u t o c l a v e : A s m a l l amount o f P^S^ was p l a c e d i n a n a u t o c l a v e . The a i r was r e m o v e d f r o m t h e a u t o c l a v e a n d B F , was c o n d e n s e d o n t o t h e P.S-,. The 3 4 3 a u t o c l a v e was s e a l e d a n d t h e n h e a t e d w i t h a n i n f r a r e d l a m p f o r 20 h o u r s . A t t h a t t i m e , t h e g a s e s w e r e r e m o v e d f r o m t h e a u t o c l a v e ; a n i n f r a r e d s p e c t r u m o f t h e s o l i d r e m a i n i n g was i d e n t i c a l t o t h a t o f p u r e P^S^ i n d i c a t i n g t h a t no r e a c t i o n h a d o c c u r r e d . B C 1 5 w i t h I ' 4 S 5 : ( i ) n e a t ( a t 0 ° C ) : A s a m p l e o f P^S^ was p l a c e d i n a p e a r f l a s k a n d a t t a c h e d t o a v a c u u m l i n e . S u f f i c i e n t B C 1 , t o c o v e r a l l t h e P,S, was c o n d e n s e d i n t h e f l a s k . 3 4 5 The f l a s k was warmed t o 0°0 b u t t h e r e was no e v i d e n c e o f r e a c t i o n . ( i i ) n e a t ( i n a n a u t o c l a v e ) : A p p r o x i m a t e l y 4-5 m i s . o f B C l ^ w e r e c o n d e n s e d i n t o a n e v a c u a t e d a u t o c l a v e c o n t a i n i n g a s m a l l amount o f P.S,. The a u t o c l a v e was t h e n h e a t e d 4 3 o v e r n i g h t w i t h a n i n f r a r e d l a m p . G a s e o u s p r o d u c t s w e r e r e m o v e d f r o m t h e a u t o c l a v e l e a v i n g b e h i n d u n r e a c t e d P 4 S 5 , m.p. 171-2°C. P.S, w i t h MeSO^F: 4 3 3 A s m a l l amount o f P.S-, was t r e a t e d w i t h a n e x c e s s o f 4 5 MeSO^F a n d t h e m i x t u r e was h e a t e d u n d e r r e f l u x w i t h 3 -23-s t i r r i n g i n a n i t r o g e n a t m o s p h e r e . F o r t h e f i r s t two h o u r s no v i s i b l e r e a c t i o n o c c u r r e d ; t h e n P^S^ was o b s e r v e d t o v e r y s l o w l y d i s a p p e a r a c c o m p a n i e d b y s i m u l -t a n e o u s f o r m a t i o n o f a w h i t i s h p r o d u c t . A f t e r a n a d d i t i o n a l two h o u r s , more o f t h e w h i t e p r o d u c t h a d f o r m e d b u t n o t a l l t h e P^S^ h a d r e a c t e d . I t was f o u n d h o w e v e r t h a t c o n t i n u e d r e f l u x i n g a t t h i s s t a g e b r o u g h t a b o u t r a p i d f o r m a t i o n o f a d a r k b r o w n s o l u t i o n a n d s o t h e r e a c t i o n was s t o p p e d . E x c e s s MeSO^F was r e m o v e d o n t h e v a c u um l i n e a n d t h e r e m a i n i n g p r o d u c t was w a s h e d w i t h C S 2 t o r e m o v e a n y u n r e a c t e d P^S^. The w h i t i s h m a t e r i a l was f o u n d t o be i n s o l u b l e i n n o n - p o l a r o r g a n i c s o l v e n t s b u t was s o l u b l e i n d i m e t h y l s u l p h o x i d e , a c e t o n i t r i l e a n d d i m e t h y l f o r m a r a i d e a l t h o u g h r e c o v e r y f r o m t h e s e l a t t e r t h r e e s o l v e n t s was e x t r e m e l y d i f f i c u l t . H o w e v e r t h e p r o d u c t was s u c c e s s f u l l y c r y s t a l l i z e d f r o m h o t w a t e r t o y i e l d w e l l - f o r m e d c r y s t a l s , m.p. ) 270°C. F o u n d : C 1 6 . 3 3 % H 4 . 3 4 % C H 3 P 4 S 3 + S 0 5 F " r e q u i r e s C 3 . 5 9 % H 0 . 9 0 % O b v i o u s l y t h i s p r o d u c t i s n o t w h a t was h o p e d f o r . 19 A F n.m.r. s p e c t r u m showed a s i n g l e t a t + 1 3 0 p.p.m. ( e x t . G F C l ^ ) i n d i c a t i n g t h e p r e s e n c e o f i o n i c f l u o r i d e . 19 The f l u o r o s u l p h a t e a n i o n h a s a ^F c h e m i c a l s h i f t o f 1 - 3 9 . 2 p.p.m. w i t h r e s p e c t t o C F C l ^ . The H n.m.r. s p e c t r u m showed a s i n g l e t a t 7.067". The m e t h y l g r o u p m u s t be a t t a c h e d t o s u l p h u r t h e r e f o r e , a s a d o u b l e t w o u l d be e x p e c t e d i f i t w e r e a t t a c h e d t o p h o s p h o r u s . - 2 4 -I t i s q u i t e a p p a r e n t t h a t t o t a l d e c o m p o s i t i o n h a s o c c u r r e d a n d c o n s e q u e n t l y t h i s r e a c t i o n was d i s c a r d e d . P^S^ w i t h T r i e t h y l o x o n i u m t e t r a f l u o r o b o r a t e : T r i e t h y l o x o n i u m t e t r a f l u o r o b o r a t e i s e x t r e m e l y h y -g r o s c o p i c a n d was w e i g h e d a n d t r a n s f e r r e d i n a d r y b o x . E t 5 0 + B F 4 ( 0 . 4 0 1 8 gms, 2.12 mmoles) a n d P^S^ ( 0 . 4 6 5 5 gms, 2.12 mmoles) w e r e c o m b i n e d i n d r y m e t h y l e n e c h l o r i d e a n d h e a t e d u n d e r r e f l u x i n a n i t r o g e n a t m o s p h e r e . Upon d i s t i l l i n g o f f t h e s o l v e n t , P^S^ was r e c o v e r e d u n r e a c t e d a n d i d e n t i f i e d b y i t s m e l t i n g p o i n t , 171-2°C. P^S^ w i t h T r i p h e n y l m e t h y l h e x a c h l o r o a n t i m o n a t e : 20.0 m i s . o f a s o l u t i o n o f P h ^ C + S b C l g ( 0 . 0 2 9 9 M i n CH" 2C1 2) w e r e a d d e d t o P^S^ ( 0 . 1 3 1 8 gms, 0.597 mmoles) i n C H 2 C 1 2 u n d e r a b l a n k e t o f d r y n i t r o g e n . No r e a c t i o n was a p p a r e n t a n d s o t h e s o l u t i o n was h e a t e d u n d e r r e f l u x f o r 2 h o u r s i n a n i t r o g e n a t m o s p h e r e . The s o l u t i o n was c o n c e n t r a t e d a n d t h e n c o o l e d i n i c e t o y i e l d P^S^, i d e n t i f i e d b y i t s m e l t i n g p o i n t , 173°C, s h a r p . P,S, w i t h S b C l r - : 4 3 5_ I n t h e a b s e n c e o f s o l v e n t , P^S^ a n d S b C l ^ r e a c t t o -g e t h e r e x t r e m e l y e x o t h e r m i c a l l y . I f S b C l ^ i s a d d e d t o a m i x t u r e o f P^S^ i n d r y c h l o r o f o r m , t h e n t h e P^S^ r e a c t s r a p i d l y a n d w h i t e c r y s t a l s a r e f o r m e d . T h e s e c r y s t a l s w e r e c o l l e c t e d o n s i n t e r e d g l a s s i n a g l o v e b a g f i l l e d w i t h n i t r o g e n , w a s h e d w i t h a l i t t l e d r y c h l o r o f o r m a n d v a c u u m - d r i e d . A n a l y t i c a l r e s u l t s showed t h a t t h e c r y s t a l s c o n t a i n e d no s u l p h u r ; o b v i o u s l y c o m p l e t e decomp-o s i t i o n h a d o c c u r r e d . The c r y s t a l s a r e e x t r e m e l y h y g r o -s c o p i c i n a i r a n d a r e c a p a b l e o f o x i d i z i n g i o d i d e t o i o d i n e , i n d i c a t i n g t h e p r e s e n c e o f Sb^« I t i s t h e r e f o r e l i k e l y t h a t t h e s e c r y s t a l s a r e P C l ^ S b C l g . P,S, w i t h S b F c : 4 3 5_ ( i ) n e a t : A f t e r a b r i e f i n d u c t i o n p e r i o d , s o l i d P^S^ r e a c t e d v i o l e n t l y w i t h l i q u i d S b F ^ . P r o d u c t s i n c l u d e d b r o w n f u m e s a n d b r o w n p o w d e r f l e c k e d w i t h d a r k b l u e c o l o u r s . ( i i ) i n l i q u i d SO • A p p r o x i m a t e l y 2 m i s . o f S b F c w e r e a d d e d t o a b o u t 30 m i s . o f l i q u i d s u l p h u r d i o x i d e a n d t h e n s o l i d P^S^ was a d d e d i n p o r t i o n s u n d e r n i t r o g e n . The s o l u t i o n t u r n e d b r o w n i m m e d i a t e l y . The s u l p h u r d i o x i d e was a l l o w e d t o e v a p o r a t e o v e r n i g h t . The o n l y s o l i d p r o d u c t o b s e r v e d was a mass o f y e l l o w - o r a n g e m a t e r i a l w h i c h d i d n o t m e l t b e l o w 250°C, a n d t u r n e d b l a c k a t 230°C. The two c r y s t a l m o d i f i c a t i o n s o f S b ^ S ^ a r e o r a n g e a n d b l a c k ; i n a d d i t i o n t h i s o r a n g e m a t e r i a l d i s s o l v e d i n h o t , c o n c e n t r a t e d h y d r o c h l o r i c a c i d . A p o r t i o n o f t h i s s o l u t i o n was d i l u t e d w i t h w a t e r a n d a p i e c e o f z i n c was a d d e d . An i m m e d i a t e b l a c k c o a t i n g f o r m e d on t h e z i n c i n d i c a t i n g t h e p r e s e n c e o f a n t i m o n y i o n s . The p h o s p h o r u s - 2 6 -i s p r e s u m a b l y l o s t a s v o l a t i l e p h o s p h o r u s - f l u o r i n e compounds s u c h a s P F ^ t P F ^ a n d S = P F 3 . P,S, w i t h A s F c : 4 3 5_ A s a m p l e o f P^S^ ( 0 . 1 4 0 7 gms, 0.64 mmoles) was p l a c e d i n a r o u n d - b o t t o m f l a s k ; t h e f l a s k was e v a c u a t e d a n d g a s e o u s A s F ^ was i n t r o d u c e d t o t h e s y s t e m . Immed-i a t e l y b r o w n i s h f u m e s e v o l v e d . A s F ^ was c o n d e n s e d o n t o t h e P ^ S 5 b y c o o l i n g t h e f l a s k t o -196°C. When t h e f l a s k was warmed a n d t h e A s F ^ m e l t e d , t h e r e was much f r o t h i n g a n d a b l u i s h s o l u t i o n f o r m e d . A s F ^ was c o n d e n s e d o n t o P^S^ s e v e r a l t i m e s t o e n s u r e c o m p l e t e r e a c t i o n . F i n a l l y t h e f l a s k was e v a c u a t e d o v e r n i g h t . The w e i g h t o f m a t e r i a l r e m a i n i n g was 0.1173 gms. i n d i c a t i n g t h a t a t l e a s t p a r t i a l d e c o m p o s i t i o n i n t o v o l a t i l e p r o d u c t s h a d o c c u r r e d . A s a r e s u l t t h e r e a c t i o n was n o t i n v e s t i g a t e d f u r t h e r . P . S , w i t h N o 0 . : 4 3 2 4 L i q u i d d i n i t r o g e n t e t r o x i d e was p o u r e d i n t o a b e a k e r a n d a s m a l l amount o f P^S^ was a d d e d . T h e r e was a n i m m e d i a t e e x o t h e r m i c r e a c t i o n a n d e l e m e n t a l s u l p h u r was t h e o n l y s o l i d m a t e r i a l i s o l a t e d . A n y p h o s p h o r u s o x i d e s f o r m e d a r e u n d o u b t e d l y c o n v e r t e d t o a c i d s v e r y q u i c k l y . P^S^ w i t h d i m e t h y l s u l p h o x i d e : P .S, i s s l i g h t l y s o l u b l e i n d i m e t h y l s u l p h o x i d e a t - 2 7 -room t e m p e r a t u r e b u t g i v e s no e v i d e n c e o f r e a c t i o n . Upon w a r m i n g t h e m i x t u r e t o 60-70°C a r e a c t i o n i s i n i t i a t e d w h i c h p r o c e e d s v e r y v i g o r o u s l y a n d r a p i d l y . The r e a c t i o n i s a c c o m p a n i e d b y p o p p i n g n o i s e s a n d t h e e v o l u t i o n o f a g a s w h i c h was m o s t l i k e l y d i m e t h y l s u l p h i d e a s e v i d e n c e d b y i t s f o u l s m e l l . A s t h e P^S^ r e a c t e d , a y e l l o w o i l f o r m e d ; when t h e s o l u t i o n was c o n c e n t r a t e d a f t e r t h e r e a c t i o n h a d f i n i s h e d , t h e o i l c r y s t a l l i z e d . The m e l t i n g p o i n t o f t h e p r o d u c t (118-119°C, s h a r p ) , i t s p o o r i n f r a r e d a b s o r p t i o n a n d f i n a l l y i t s mass s p e c t r u m ( p e a k s o b s e r v e d o n l y a t m u l t i p l e s o f 32) e s t a b l i s h b e y o n d d o u b t t h a t a n o t h e r n o v e l r o u t e t o t h e s y n t h e s i s o f e l e m e n t a l s u l p h u r h a d b e e n f o u n d . POLAROGRAPHY F o r e x p e r i m e n t s i n v o l v i n g t h e p o l a r o g r a p h i c r e d u c t i o n o f P^S^, i t was i m p o r t a n t t o e x c l u d e b o t h w a t e r a n d o x y g e n . The s o l v e n t s u s e d , b e n z e n e a n d a c e t o n i t r i l e , w e r e d r i e d o v e r n i g h t w i t h C a H 2 a n d t h e n d i s t i l l e d u n d e r n i t r o g e n . A 1:1 b e n z e n e - a c e t o n i t r i l e m i x t u r e was f o u n d t o be i d e a l a s i t a l l o w e d d i s s o l u t i o n o f e n o u g h P^S^ a n d o f e n o u g h t e t r a - n - b u t y l a m m o n i u m i o d i d e , t h e s u p p o r t i n g e l e c t r o l y t e , t o o b t a i n g o o d p o l a r o g r a m s . The s o l u t i o n s u s e d w e r e 0.002 M w i t h r e s p e c t t o P^S^ and 0.1 M w i t h r e s p e c t t o t e t r a - n - b u t y l a m m o n i u r a i o d i d e . S o l u t i o n s w e r e p r e p a r e d i n a n i t r o g e n a t m o s p h e r e a n d , t o remove t h e l a s t t r a c e s o f o x y g e n , w e r e v i g o r o u s l y f l u s h e d w i t h h i g h p u r i t y n i t r o g e n f o r a t l e a s t f i f t e e n m i n u t e s -28-p r i o r t o u s e . I t was p a r t i c u l a r l y i m p o r t a n t t o r e m o v e o x y g e n b e c a u s e i t s s e c o n d r e d u c t i o n wave o c c u r r i n g a t E^= - 0 . 7 8 v was v e r y c l o s e t o t h e wave f o u n d f o r P^S^. A l l p o l a r o g r a m s w e r e r u n o n a S a r g e n t P o l a r o g r a p h , M o d e l X X I . The e l e c t r o d e s u s e d w e r e a d r o p p i n g m e r c u r y e l e c t r o d e a n d a s t a n d a r d c a l o m e l e l e c t r o d e . The s o l v e n t m i x t u r e u s e d was f o u n d t o be s t a b l e i n t h e r e g i o n 0 t o - 2 . 5 v . A t more n e g a t i v e r e d u c t i o n p o t e n t i a l s , a c e t o n i t r i l e i s r e d u c e d . The s u p p o r t i n g e l e c t r o l y t e , t e t r a - n - b u t y l a m m o n i u m i o d i d e i s s t a b l e i n t h e r e g i o n -0.5 t o - 3 . 0 v . P o l a r o g r a m s c o u l d t h e r e f o r e o n l y be r e c o r d e d i n t h e r e g i o n - 0 . 5 t o -2.5 v o l t s , b u t a s p r e l i m i n a r y t e s t s showed t h a t t h e r e w e r e no w aves i n t h e r e g i o n - 1 . 5 t o - 2 . 5 v . , s u b s e q u e n t p o l a r o g r a m s w e r e g e n e r a l l y r u n o n l y i n t h e r a n g e -0.5 t o - 1 . 5 v . ? 4 S 3 h a s a r e p r o d u c i b l e h a l f - w a v e p o t e n t i a l o f - 0 . 9 5 v . ; no v i s i b l e c o l o u r c h a n g e o c c u r r e d d u r i n g t h i s r e d u c t i o n . The r e d u c t i o n i s a p p a r e n t l y i r r e v e r s i b l e a s N e r n s t p l o t s f r o m s e v e r a l d i f f e r e n t p o l a r o g r a m s g a v e v a l u e s o f n , t h e n u mber o f e l e c t r o n s t r a n s f e r r e d i n t h e r e d u c t i o n p r o c e s s , r a n g i n g f r o m 0.5 t o 0.7. The c a u s e o f t h e i r r e v e r s i b i l i t y i s u n k n o w n ; h o w e v e r c a g e f r a c t u r e o r r e a c t i o n w i t h m e r c u r y a r e two p o s s i b i l i t i e s . E.S.R. ATTEMPTS: To t e s t t h e p o s s i b i l i t y o f r a d i c a l a n i o n f o r m a t i o n -29-STOPCOCK-TUNGSTEN ANODE MERCURY SINTERED GLASS SOLUTION-— GRADED QUARTZ-PYREX SEAL- NSULATED PLATINUM WIRE QUARTZ GLASS t BARE PLATINUM CATHODE • FIG. 1': E.s.r. e l ec t ro l y s i s ce l l - 3 0 -d u r i n g t h e r e d u c t i o n o f ^^S-z,* a c o n t r o l l e d e l e c t r o l y s i s was c a r r i e d o u t u s i n g t h e a p p a r a t u s i l l u s t r a t e d i n F i g . l . T h i s a p p a r a t u s i s d e s i g n e d t o f i t i n t o a V a r i a n E3 e l e c t r o n s p i n r e s o n a n c e ( e . s . r . ) s p e c t r o m e t e r s o t h a t t h e g e n e r a t i o n o f a r a d i c a l c a n i m m e d i a t e l y he d e t e c t e d . S u f f i c i e n t s o l u t i o n i s i n t r o d u c e d t o t h e c e l l s o t h a t t h e t u n g s t e n a n o d e i s i m m e r s e d . The p l a t i n u m w i r e c a t h o d e i s i n s u l a t e d e x c e p t a t t h e v e r y t i p s o t h a t r e d u c t i o n i s c o n c e n t r a t e d i n a v e r y s m a l l v o l u m e . The s y s t e m was s u c c e s s f u l l y t e s t e d b y e l e c t r o l y t i c g e n e r a t i o n o f t h e n i t r o b e n z e n e r a d i c a l a n i o n . The c o m p l e t e 5 4 - l i n e s p e c t r u m o f t h i s s p e c i e s was o b s e r v e d . To t e s t t h e f o r m a t i o n o f a r a d i c a l a n i o n o f P^S^, s o l u t i o n s o f d r y 1:1 b e n z e n e - a c e t o n i t r i l e w e r e p r e p a r e d ; t h e s e w e r e 0.001 M w i t h r e s p e c t t o P^S^ a n d 0.2 M w i t h r e s p e c t t o t e t r a - n - b u t y l a m m o n i u m i o d i d e . Once p l a c e d i n t h e e l e c t r o l y s i s c e l l , t h e s o l u t i o n s w e r e d e g a s s e d b y vacuum s o f a r a s was p o s s i b l e . A p o t e n t i a l o f -1.2 v . was a p p l i e d t o t h e c e l l , s u f f i c i e n t t o e n s u r e t h a t a r e a s o n a b l e amount o f t h e r e d u c e d s p e c i e s w o u l d be p r e s e n t , b u t no e . s . r . s p e c t r u m c o u l d be o b t a i n e d . V a r i a t i o n o f t h e a p p l i e d p o t e n t i a l was e q u a l l y u n s u c c e s s f u l i n o b t a i n i n g a s p e c t r u m . ULTRAVIOLET SPECTRUM U l t r a v i o l e t s p e c t r a w e r e r e c o r d e d u s i n g a P e r k i n E l m e r C o l e m a n 124 D o u b l e Beam S p e c t r o p h o t o m e t e r . - 3 1 -Two s o l u t i o n s w e r e p r e p a r e d f o r d e t e r m i n a t i o n o f t h e m o l e c u l a r e x t i n c t i o n c o e f f i c i e n t s . The f i r s t was a 3.49x10 M s o l u t i o n o f P^S^ i n S p e c t r o g r a d e c h l o r o f o r m ; t h e s e c o n d was a 3 . 5 0 x l 0 ~ 5 M s o l u t i o n o f P.S, i n 9 5 % 4 3 e t h a n o l . The UV s p e c t r u m o f P^S^ e x h i b i t s t w o p e a k s i n t h e r e g i o n 3 8 0 - 2 0 0 nm., one a t 343 nm. (€=217) a n d a n o t h e r A a t 206 nm. (€"=1.38x10 ) . A c o n c e n t r a t e d s o l u t i o n o f P^S^ i n c a r b o n d i s u l p h i d e d i d n o t g i v e a n y a b s o r p t i o n i n t h e r e g i o n 8 0 0 - 3 5 0 nm. P^S^ w i t h t h i o p h i l e s : w i t h N a „ S 0 , 2 3 A s o l u t i o n o f P^S^ ( 0 . 6 3 2 3 gms f 2.87 mmoles) i n C S 2 was s t i r r e d v i g o r o u s l y o v e r n i g h t w i t h a n a q u e o u s s o l u t i o n c o n t a i n i n g s o d i u m s u l p h i t e ( 0 . 6 5 0 9 gms, 5.17 m m o l e s ) . The a q u e o u s l a y e r was s e p a r a t e d , a n d t h e C S ^ l a y e r a n d t h e r e a c t i o n v e s s e l w e r e w a s h e d w i t h s e v e r a l p o r t i o n s o f d i s t i l l e d w a t e r . The w a s h i n g s w e r e c o m b i n e d w i t h t h e b u l k o f t h e a q u e o u s l a y e r a n d t h i s s o l u t i o n was p l a c e d i n a 100 m l . v o l u m e t r i c f l a s k a n d d i l u t e d t o t h e mark. 25 m l . a l i q u o t s w e r e w i t h d r a w n , a f e w m i s . o f f r e s h l y -p r e p a r e d s t a r c h i n d i c a t o r w e r e a d d e d a n d t h e s o l u t i o n was t i t r a t e d w i t h 0.0531 M i o d i n e s o l u t i o n . ( T h e s t a n d a r d i o d i n e s o l u t i o n was p r e p a r e d b y a d d i n g a n a c c u r a t e l y w e i g h e d p o r t i o n o f K I O ^ t o a s o l u t i o n o f K I i n d i l u t e s u l p h u r i c a c i d . ) The t i t r e o f i o d i n e r e q u i r e d t o n e u t r a l i z e a n a l i q u o t was e x a c t l y t h a t r e q u i r e d a s s u m i n g t h a t o n l y s u l p h i t e i o n , a n d n o t t h i o s u l p h a t e , - 3 2 -was p r e s e n t . The r e a c t i o n o f s u l p h i t e w i t h i o d i n e i s : I 2 + S 0 5 = + H 2 0 - * S 0 4 = + 2 1 " + 2 H + w h i l s t t h a t o f t h i o s u l p h a t e w i t h i o d i n e i s : I 2 + 2 S 2 0 3 = — > 2 1 " + S 4 0 6 = T h u s f o r m a t i o n o f a n y t h i o s u l p h a t e s h o u l d r e d u c e t h e v o l u m e o f s t a n d a r d i o d i n e s o l u t i o n r e q u i r e d f o r n e u t r a l -i z a t i o n . B u t a s s t a t e d p r e v i o u s l y , t h e v o l u m e o f i o d i n e r e q u i r e d f o r n e u t r a l i z a t i o n i n d i c a t e s t h a t n o s i g n i f i c a n t a m o u n t s o f t h i o s u l p h a t e h a d f o r m e d . w i t h KCN A s o l u t i o n o f P^S^ ( 0 . 9 9 8 1 gms, 4.54 mmoles) was s t i r r e d v i g o r o u s l y o v e r n i g h t w i t h a n a q u e o u s s o l u t i o n o f KCN ( 0 . 8 8 3 4 gms, 13.6 mmoles.) The a q u e o u s l a y e r was s e p a r a t e d f r o m t h e C S 2 l a y e r i n a s e p a r a t o r y f u n n e l . The C S 2 l a y e r was w a s h e d w i t h w a t e r s e v e r a l t i m e s a n d t h e c o m b i n e d a q u e o u s p o r t i o n s w e r e p o u r e d i n t o a v o l u m e t r i c f l a s k a n d d i l u t e d t o t h e m a r k . To t e s t f o r t h e p r e s e n c e o f t h i o c y a n a t e , t h r e e a l i q u o t s w e r e w i t h d r a w n a n d e a c h t r e a t e d w i t h 0.5 m i s B r 2 a n d 1 m l c o n c e n t r a t e d HNO^. O x i d a t i o n a p p a r e n t l y p r o c e e d e d s m o o t h l y a n d t h e s o l u t i o n s w e r e c o n c e n t r a t e d t o 20 m i s . C o n c e n t r a t e d H C l was a d d e d t o d e s t r o y t h e n i t r a t e i o n s a n d when no more N 0 2 was e v o l v e d , t h e s o l u t i o n s w e r e n e u t r a l i z e d w i t h c o n c e n t r a t e d NaOH a n d t h e n s l i g h t l y a c i d i f i e d w i t h H C l t o p r e v e n t c o - p r e c i p i t a t i o n o f p h o s p h a t e s . The s o l u t i o n s -33-w e r e t h e n d i l u t e d t o 100 m i s . h e a t e d t o " b o i l i n g a n d a h o t d i l u t e B a C l g s o l u t i o n was a d d e d d r o p w i s e u n t i l no f u r t h e r p r e c i p i t a t i o n o c c u r r e d . The p r e c i p i t a t e d BaSO^ was c o l l e c t e d o n s i n t e r e d g l a s s , w a s h e d w i t h w a t e r a n d a c e t o n e a n d d r i e d a t 100°C. The a v e r a g e w e i g h t o f BaSO^ was 0.048+.003 gms. T h i s c o r r e s p o n d s t o r e m o v a l o f 7.5+.4% o f t h e t o t a l s u l p h u r a t o m s a v a i l a b l e f r o m P^S^. w i t h P P h 5 : ( i ) A m i x t u r e o f P^S^ ( 0 . 4 0 3 4 gms, 1.83 mmoles) a n d Ph ^ P ( 0 . 4 8 8 8 gms, 1.83 mmoles) was m e l t e d t o g e t h e r i n a s e a l e d t u b e a t 100°C. A f t e r one h o u r a t t h i s t e m p e r -a t u r e t h e m i x t u r e h a d t u r n e d r e d - o r a n g e . The r e a c t i o n was l e f t o v e r n i g h t a n d t h e n t h e m i x t u r e was c o o l e d a n d t h e t u b e b r o k e n u n d e r n i t r o g e n . T h i s m i x t u r e c a n be s p o n t a n -e o u s l y i n f l a m m a b l e s o a n i n e r t a t m o s p h e r e was e s s e n t i a l . The r e d m a t e r i a l was g r o u n d t o a f i n e p o w d e r a n d t h e n e x t r a c t e d w i t h C S 2 . The C S 2 s o l u t i o n was p u t down a c o l u m n o f 8 0 - 2 0 0 mesh a l u m i n a a n d a p p r o x i m a t e l y t w e n t y f r a c t i o n s w e r e c o l l e c t e d . A s m a l l p o r t i o n o f i m p u r e P 4 S 3 was i s o l a t e d (m.p. 164-168°C, l i t . 172-3°C) b u t b y f a r t h e m a j o r amount o f m a t e r i a l m e l t e d a t 159-161°C. T h i s m a t e r i a l was r e c r y s t a l l i z e d f r o m e t h a n o l t o y i e l d n e e d l e -l i k e c r y s t a l s . P o u n d : C 7 3 . 1 3 % H 5 . 3 3 % P h 5 P = S r e q u i r e s C 7 3 . 4 5 % H 5.14% No u n r e a c t e d P h ^ P was i s o l a t e d s o t h a t i t a p p e a r s t h e r e a c t i n g r a t i o o f Ph-^P i s c o n s i d e r a b l y more t h a n 1:1. - 3 4 -( i i ) I n o r d e r t o o b t a i n a somewhat more p u r e s a m p l e o f t h e r e d b y p r o d u c t , t h e r e a c t i o n o f P h ^ P w i t h P^S^ was t e s t e d i n s o l u t i o n . A s s u m i n g t h a t t h i s m a t e r i a l i s p o l y m e r i c , t h e u s e o f s o l v e n t m i g h t h e l p p r e v e n t i m p u r i t i e s f r o m b e i n g t r a p p e d i n i t s n e t w o r k . P h ^ P a n d P^S^ do n o t r e a c t i n b o i l i n g C S 2 o r i n b o i l i n g b e n z e n e . I n b o i l i n g t o l u e n e , t h e r e i s v e r y l i t t l e r e a c t i o n a s e v i d e n c e d b y f o r m a t i o n o f t h e r e d b y p r o d u c t . I n b o i l i n g x y l e n e t h e r e a c t i o n i s somewhat f a s t e r a n d a v e r y f i n e r e d p r e c i p i t a t e was o b t a i n e d . A l l t h e s e r e a c t i o n s w e r e c a r r i e d o u t u n d e r n i t r o g e n . T h i s r e d m a t e r i a l was t h e n e x t r a c t e d w i t h G S 2 a n d t h e n d r i e d i n v a c u o w i t h h e a t i n g . C a r b o n a n d h y d r o g e n a n a l y s e s g a v e v a l u e s o f 1.71%C a n d 0.51%H. A p h o s p h o r u s a n a l y s i s g a v e a v a l u e o f 7 7 . 2 1 % P . The r e m a i n d e r i s p r e s u m a b l y s u l p h u r . A mass s p e c t r u m o f t h i s p r o d u c t showed t h e b a s e p e a k t o be m/e 124 b u t s i g n i f i c a n t p e a k s w e r e a l s o s e e n f o r P^S^, P P h ^ a n d S=PPh,. J P 4 S 5 w i t h V O ( a c a c ) 2 : A m i x t u r e o f P^S^ ( 0 . 1 2 9 1 gms, 0.587 mmoles) a n d b i s ( a c e t y l a c e t o n a t o ) o x o v a n a d i u m I V ( 0 . 1 5 6 0 gms, 0.587 mmoles) was h e a t e d t o g e t h e r i n r e f l u x i n g b e n z e n e i n a n i t r o g e n a t m o s p h e r e . A f t e r f i v e h o u r s t h e s o l u t i o n was c o o l e d a n d p o u r e d i n t o p e t e t h e r (30-60°). A n i n f r a r e d s p e c t r u m o f t h e p r e c i p i t a t e d b l u e m a t e r i a l was i d e n t i c a l t o t h a t o f p u r e V 0 ( a c a c ) 9 . No r e a c t i o n o c c u r r e d . - 3 5 -( N b C l 5 ) 2 w i t h P 4 S 3 : N i o b i u m p e n t a c h l o r i d e d i m e r ( 0 . 6 2 6 9 gms., 2.35 mmoles) a n d P^S^ ( 0 . 5 1 6 5 gms., 2.35 mmoles) w e r e m i x e d t o g e t h e r i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . The m i x t u r e was h e a t e d u n d e r r e f l u x o v e r n i g h t , a l l o w e d t o c o o l a n d t h e n t r a n s f e r r e d t o a g l o v e b a g . The a p p a r e n t p r o d u c t , a l i g h t b r o w n p o w d e r , was c o l l e c t e d on s i n t e r e d g l a s s a n d t h e n v a c u u m - d r i e d . The i n f r a r e d s p e c t r u m o f t h i s b r o w n i s h m a t e r i a l was e s s e n t i a l l y t h e same a s t h a t o f ( N b C l ^ ) 2 w i t h t h e e x c e p t i o n o f a f e w m i n o r p e a k s w h i c h w e r e a t t r i b u t e d t o i m p u r i t i e s . C o n c e n t r a t i o n o f t h e r e d f i l t r a t e r e s u l t e d i n p r e c i p i t a t i o n o f P^S^, i d e n t i f i e d b y i t s m e l t i n g p o i n t , 172-3°C. - 3 6 -P 4 S 5 w i t h ( P P h 3 ) 2 N i ( C O ) 2 : A m i x t u r e o f P 4 S 5 ( 0 . 1 2 0 7 gms, 0.549 mmoles) a n d ( P P h 5 ) 2 N i ( C O ) 2 ( 0 . 3 5 3 3 gms, 0.549 mmoles) was h e a t e d u n d e r r e f l u x i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . A l m o s t i m m e d i a t e l y a b l a c k p r e c i p i t a t e a p p e a r e d . The r e a c t i o n was l e f t o v e r n i g h t a n d t h e n t h e s o l u t i o n was f i l t e r e d . A n i n f r a r e d s p e c t r u m o f t h e b l a c k m a t e r i a l showed o n l y b r o a d weak a b s o r p t i o n a n d no b a n d s t h a t c o u l d be 29 a s s i g n e d t o e i t h e r CO o r P h ^ P . N i x o n e t a l . J a p p a r e n t l y i s o l a t e d s i m i l a r m a t e r i a l d u r i n g t h e c o u r s e o f t h e i r w o r k o n N i t P ^ S ^ ) ^ . The b r o w n i s h f i l t r a t e f r o m t h i s r e a c t i o n was p a s s e d t h r o u g h a n a l u m i n a c o l u m n . The o n l y compound i s o l a t e d h a d a b r o a d m e l t i n g r a n g e . T h i s m a t e r i a l was d i s s o l v e d i n c a r b o n t e t r a c h l o r i d e a n d f i l t e r e d t h r o u g h a c t i v a t e d c h a r c o a l . W h i t e c r y s t a l s w e r e o b t a i n e d a n d a n i n f r a r e d s p e c t r u m o f t h e s e c r y s t a l s was i n d i s t i n g u i s h a b l e f r o m t h a t o f t r i p h e n y l p h o s p h i n e s u l p h i d e . A s o b v i o u s d e c o m p o s i t i o n h a d o c c u r r e d , t h i s r e a c t i o n was n o t p u r s u e d . P „ S , w i t h S b C l , : 4 3 3_ ( i ) A m i x t u r e o f P 4 S 5 ( 1 . 8 4 7 0 gms, 8.40 mmoles) a n d S b C l ^ ( 3 . 7 6 1 4 gms, 16.5 mmoles) was h e a t e d u n d e r r e f l u x i n c a r b o n d i s u l p h i d e i n a n i t r o g e n a t m o s p h e r e . A f t e r s i x t y h o u r s t h e r e h a d b e e n no v i s i b l e r e a c t i o n . ( i i ) A m i x t u r e o f P ^ ( 1 . 0 5 2 9 gms, 4.79 mmoles) a n d S b C l ^ ( 2 . 1 5 0 0 gms, 9.47 mmoles) was f u s e d i n v a c u o a t -37-110°C. A r e d d i s h p r e c i p i t a t e a p p e a r e d i n t h e y e l l o w i s h l i q u i d . F u s i o n was c o n t i n u e d f o r a b o u t s i x t y h o u r s . U n r e a c t e d P^S^ (m.p. 172-4°C) was r e c o v e r e d f r o m t h e f u s e d mass b y w a s h i n g w i t h C H C l ^ . The f u s e d mass was g r o u n d t o a f i n e s t a t e a n d t h e n w a s h e d w i t h s e v e r a l p o r t i o n s o f C S g , i n w h i c h b o t h s t a r t i n g m a t e r i a l s a r e v e r y s o l u b l e . A n o r a n g e p r e c i p i t a t e r e m a i n e d whose i n f r a r e d s p e c t r u m showed o n l y b r o a d weak b a n d s . The o r a n g e m a t e r i a l d i d n o t m e l t b e l o w 270°C b u t t u r n e d b l a c k a t 90-100°G. I t was u n -d o u b t e d l y SiOpS-^ a s t h e two c r y s t a l m o d i f i c a t i o n s o f S b 0 S x a r e o r a n g e a n d b l a c k . - 3 8 -P 4 S 3 w i t h P d C l 2 : P^S^ ( 0 . 2 4 1 2 gms., 1.1 m m o l e s ) a n d a s u s p e n s i o n o f P d C l 2 ( 0 . 1 9 1 4 gms., 1.1 mmoles) i n a s m a l l v o l u m e o f 1:1 c h l o r o f o r m - a c e t o n e w e r e h e a t e d t o g e t h e r u n d e r n i t r o g e n f o r t h i r t y - s i x h o u r s . As no v i s i b l e r e a c t i o n h a d o c c u r r e d , t h e s o l v e n t m i x t u r e was r e m o v e d b y d i s t i l l a t i o n a n d t h e r e a c t a n t s f u s e d t o g e t h e r i n v a c u o a t 180°C. No v i s i b l e r e a c t i o n o c c u r r e d o v e r a p e r i o d o f 3 h o u r s a f t e r w h i c h t i m e m o s t o f t h e P^S^ h a d s u b l i m e d o u t . P 4 S 5 w i t h ( P h C N ) 2 P d C l 2 : S o l i d P 4 S 3 ( 0 . 1 4 9 2 gms., 0.678 mmoles) was a d d e d t o a r e d s o l u t i o n o f b i s ( b e n z o n i t r i l e ) p a l l a d o u s c h l o r i d e ( 0 . 1 1 2 3 gms., 0.339 mmoles) i n b e n z e n e a t r o o m t e m p e r a -t u r e . The s o l u t i o n r a p i d l y t u r n e d d a r k b r o w n a n d a p r e c i p i t a t e o f t h e same c o l o u r q u i c k l y a p p e a r e d . The p r e c i p i t a t e was c o l l e c t e d o n s i n t e r e d g l a s s a n d washed w i t h s e v e r a l p o r t i o n s o f b e n z e n e ; i t was i n s o l u b l e i n a l l s o l v e n t s t e s t e d a n d h a d a b r o a d m e l t i n g r a n g e , w i t h d e -c o m p o s i t i o n o c c u r r i n g , o f 225-240°C. An i n f r a r e d s p e c t r u m o f t h e p r o d u c t was o f v e r y p o o r q u a l i t y , b u t i n d i c a t e d t h a t t h e b e n z o n i t r i l e g r o u p s h a d b e e n d i s p l a c e d a s no C=N s t r e t c h i n g was v i s i b l e . B r o a d a b s o r p t i o n s w e r e s e e n c e n t r e d a t 525 cm , 470 cm a n d 3 9 0 - 4 4 0 cm The l a t t e r two p e a k s a r e i n t h e g e n e r a l r e g i o n t h a t u n c o m p l e x e d P 4 S ^ e x h i b i t s a b s o r p t i o n . T h e r e was no o b v i o u s b a n d t h a t c o u l d be a s s i g n e d t o p a l l a d i u m -- 3 9 -c h l o r i n e s t r e t c h i n g e v e n t h o u g h ( P h C N ) 2 p d c l 2 h a s m o d e r a t e a b s o r p t i o n a t 366 cm w h i c h h a s b e e n a s s i g n e d a s y ( P d - C l ) . A mass s p e c t r u m o f t h e p r o d u c t was o f e q u a l l y -p o o r q u a l i t y , a p p a r e n t l y due t o t h e l a c k o f v o l a t i l i t y o f t h e c o m p l e x . B e c a u s e o f t h e i n t r a c t a b i l i t y o f t h i s c o m p l e x , i t s p l a t i n u m a n a l o g u e was p r e p a r e d i n s t e a d . P 4 S 3 w i t h ( P h C N ) 2 P t C l 2 : • P 4 S 3 (°« 1349 gms., 0.613 mmoles) was a d d e d t o a b e n z e n e s o l u t i o n o f ( P h C N ) 2 P t C l 2 ( 0 . 1 6 5 9 gms., 0.307 m m o l e s ) . A f t e r one h o u r o f h e a t i n g u n d e r r e f l u x i n a n i t r o g e n a t m o s p h e r e a d a r k r e d - b r o w n p o w d e r h a d p r e c i p i -t a t e d . The p o w d e r was c o l l e c t e d o n s i n t e r e d g l a s s , w a s h e d s e v e r a l t i m e s w i t h b e n z e n e and a i r - d r i e d . A m e l t i n g p o i n t d e t e r m i n a t i o n was a t t e m p t e d b u t no c h a n g e i n c o l o u r o r s t a t e was o b s e r v e d u p t o 250°C. The i n f r a -r e d s p e c t r u m o f t h e p r o d u c t was v e r y s i m i l a r t o t h a t o b t a i n e d f o r t h e a n a l o g o u s p a l l a d i u m c o m p l e x . B r o a d — 1 —1 a b s o r p t i o n s w e r e s e e n c e n t r e d a t 520 cm , 470 cm a n d 440 - 3 9 0 cm""1. No b a n d was s e e n t h a t c o u l d be a s s i g n e d a s P t - C l s t r e t c h i n g e v e n t h o u g h ( P h C N ) 2 P t C l 2 h a s medium a b s o r p t i o n a t t r i b u t a b l e t o 2 ^ ( P t - C l ) a t 340 cm""1. T h i s p r o d u c t t o o was i n s o l u b l e i n a l l s o l v e n t s t e s t e d ; i t was t h e r e f o r e n o t i n v e s t i g a t e d f u r t h e r . - 4 0 -t r a n s - I r G l ( C O ) ( P h 5 P ) 2 w i t h P^S^: ( 1 : 1 m o l e h a s i s ) P^S^ ( 0 . 1 0 8 7 gms., 0.492 mmoles) a n d t r a n s -I r C l ( C O ) ( P h 5 P ) 2 ( 0 . 3 8 3 5 gms., 0.492 mmoles) w e r e m i x e d t o g e t h e r i n a b o u t 20 m i s . o f d r y b e n z e n e i n a n i t r o g e n a t m o s p h e r e . The s o l u t i o n was h e a t e d u n d e r r e f l u x f o r one h o u r t o y i e l d a mass o f v e r y s m a l l g r e e n c r y s t a l s . The c r y s t a l s w e r e c o l l e c t e d o n s i n t e r e d g l a s s , w a s h e d w i t h b e n z e n e a n d d r i e d i n v a c u o o v e r n i g h t . The p r o d u c t was i n s o l u b l e i n t e t r a h y d r o f u r a n , c h l o r o f o r m , w a t e r , a c e t o n e , m e t h a n o l , a c e t o n i t r i l e , b e n z e n e , c a r b o n d i s u l p h i d e , x y l e n e a n d was d e c o m p o s e d b y t r i g l y m e a n d s u l f o l a n e . The m a t e r i a l was e x t r a c t e d f o r t w o d a y s w i t h c h l o r o f o r m i n a n i t r o g e n a t m o s p h e r e . A n a l y t i c a l d a t a r e v e a l e d t h a t n i t r o g e n was p r e s e n t i n t h e s a m p l e , p r e s u m a b l y due t o d i s p l a c e m e n t o f c a r b o n m o n o x i d e b y m o l e c u l a r n i t r o g e n . A l l f u r t h e r m a n i p u l a t i o n s o f t h i s c o m p l e x w e r e t h e r e f o r e c a r r i e d o u t i n a h e l i u m a t m o s p h e r e . A f r e s h s a m p l e was e x t r a c t e d w i t h c h l o r o f o r m f o r two d a y s b u t n o n e o f t h e c o m p l e x d i s s o l v e d . A f e w s o l u b l e i m p u r i t i e s w e r e r e m o v e d a n d a r e a s o n a b l e a n a l y s i s was o b t a i n e d . F o u n d : G 3 0 . 4 4 % H 2 . 1 0 % P 1 9 . 9 2 % S 1 2 . 2 5 % C l 8 . 1 9 % m.p. > 270°C I r C l 2 ( H ) ( C O ) ( P h 3 P ) ( P 4 S 5 ) r e q u i r e s : C 2 9 . 4 5 % H 2 . 0 7 % P 2 0 . 0 2 % S 1 2 . 4 0 % C l 9.17% The i s o l a t i o n o f t h e e x p e c t e d p r o d u c t , I r 0 1 ( C O ) ( P h 3 P ) ( P 4 S 5 ) , a s i t s h y d r o c h l o r i d e i n a n 8 0 % y i e l d i s somewhat s u r p r i s i n g i n v i e w o f t h e f a c t t h a t a maximum' - 4 1 -o f 5 0 % w o u l d be e x p e c t e d h a d a l l t h e c h l o r i d e o r i g i n a t e d f r o m I r C l ( C O ) ( P h 3 P ) 2 . The i n f r a r e d s p e c t r u m o f I r C l 2 ( H ) (CO) ( P h ^ P ) ( P ^ S ^ ) — 1 e x h i b i t s C=0 s t r e t c h i n g a t 2045 cm , c h a r a c t e r i s t i c — 1 —1 p h e n y l a b s o r p t i o n a t 745 cm a n d 690 cm a s w e l l a s _1 n u m e r o u s b a n d s i n t h e 4 0 0 - 5 5 0 cm r e g i o n . A t t e m p t s t o o b t a i n a Raman s p e c t r u m w e r e u n s u c c e s s f u l . t r a n s - I r C l ( C O ) ( P h 5 P ) 2 w i t h P ^ : ( 1 : 2 m o l e b a s i s ) P ^ S j ( 0 . 1 7 4 6 gms., 0.794 mmoles) a n d t r a n s -I r C l ( C O ) ( P h 5 P ) 2 ( 0 . 3 0 9 4 gms., 0.397 mmoles) w e r e d i s s o l v e d i n b e n z e n e a n d h e a t e d u n d e r r e f l u x f o r t w e n t y - f o u r h o u r s i n a h e l i u m a t m o s p h e r e . The i n s o l u b l e o l i v e g r e e n p r o d u c t was w a s h e d w i t h c h l o r o f o r m a n d c a r b o n d i s u l p h i d e t o y i e l d l i g h t g r e e n m a t e r i a l whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f t h e p r e v i o u s l y c h a r a c t e r i z e d I r C l 2 ( H ) ( C O ) ( P h 5 P ) ( P 4 S 3 ) . I r C l 2 ( H ) ( C 0 ) ( P h 3 P ) ( P 4 S 3 ) w i t h B C 1 3 : I r C l 2 ( H ) ( C O ) ( P h 3 P ) ( P 4 S 3 ) ( d e n o t e d I r - 1 ) ( 0 . 0 9 8 3 gms., 0.120 m moles) was s u s p e n d e d i n d r y b e n z e n e t h a t h a d b e e n d e n i t r o g e n a t e d b y b u b b l i n g a s t r e a m o f h e l i u m t h r o u g h t h e s o l u t i o n . A s b o r o n t r i c h l o r i d e was b u b b l e d t h r o u g h t h e s u s p e n s i o n , a c o l o u r c h a n g e f r o m g r e e n t o o r a n g e o c c u r r e d w i t h i n t w e n t y m i n u t e s . B C 1 3 was b u b b l e d t h r o u g h t h e s u s p e n s i o n f o r a n a d d i t i o n a l h o u r b u t no f u r t h e r c o l o u r c h a n g e was o b s e r v e d . E x c e s s B C 1 , was r e m o v e d b y f l u s h i n g - 4 2 -t h e s o l u t i o n w i t h h e l i u m . The s o l i d p r o d u c t was c o l l e c t e d on s i n t e r e d g l a s s i n a g l o v e b a g f i l l e d w i t h n i t r o g e n . As t h e p r o d u c t was d r i e d i n v a c u o , i t s l o w l y c h a n g e d c o l o u r f r o m o r a n g e t o g r e e n . A n i n f r a r e d s p e c t r u m c o n f i r m e d t h a t t h e g r e e n m a t e r i a l was I r - l . I r - 1 w i t h NaBPh^: A m i x t u r e o f I r - 1 ( 0 . 0 8 9 6 gms., 0.11 mmoles) a n d NaBPh^ ( 0 . 0 4 1 9 gms., 0.11 mmoles) i n t e t r a h y d r o f u r a n was s h a k e n f o r two d a y s . No v i s i b l e r e a c t i o n o c c u r r e d . The m i x t u r e was t h e n h e a t e d u n d e r r e f l u x f o r two d a y s . The s u p e r n a t a n t l i q u i d was f i l t e r e d o f f a n d t e s t e d w i t h AgNO^. No p r e c i p i t a t e f o r m e d , i n d i c a t i n g t h e a b s e n c e o f C l " " i n s o l u t i o n . I r - 1 w i t h C o C l 2 : I r - 1 ( 0 . 2 2 6 4 gms., 0.277 mmoles) a n d C o C l 2 ( 0 . 0 2 0 2 gms., 0.138 mmoles) w e r e h e a t e d u n d e r r e f l u x o v e r n i g h t i n d r y m e t h a n o l i n a h e l i u m a t m o s p h e r e . I r - 1 was f i l t e r e d o f f washed w i t h a c e t o n e a n d a i r - d r i e d ; i t was i d e n t i f i e d b y i t s i n f r a r e d s p e c t r u m . The f i l t r a t e was p u r p l e i n d i c a t i n g t h a t C o C l 2 was i n s o l u t i o n . I r - 1 w i t h S n C l 2 : I r - 1 ( 0 . 2 0 1 0 gms., 0.246 mmoles) a n d S n C l 2 . 2 H " 2 0 ( 0 . 0 5 2 3 gms., 0.246 mmoles) w e r e h e a t e d u n d e r r e f l u x i n m e t h a n o l o v e r n i g h t a n d i n a h e l i u m a t m o s p h e r e . The - 4 3 -m i x t u r e was t h e n f i l t e r e d t o r e m o v e t h e g r e e n m a t e r i a l ; i t was w a s h e d w i t h w a t e r a n d m e t h a n o l t o r e m o v e s t a n n o u s c h l o r i d e . A n i n f r a r e d s p e c t r u m o f t h e g r e e n m a t e r i a l showed t h a t i t was I r - 1 . R h C l ( P h 3 P ) 3 w i t h P ^ : A m i x t u r e o f R h C l ( P h 3 P ) 3 ( 0 . 7 1 3 8 gms., 0.785 mmoles) a n d P 4 S 3 ( 0 . 1 7 2 6 gms., 0.785 mmoles) was h e a t e d u n d e r r e f l u x i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . A l m o s t i m m e d i a t e l y a d a r k b r o w n p r e c i p i t a t e o c c u r r e d . A f t e r s e v e r a l h o u r s , t h e r e a c t i o n m i x t u r e was c o o l e d a n d t h e p r o d u c t was c o l l e c t e d o n s i n t e r e d g l a s s i n a n i t r o g e n a t m o s p h e r e . I t was d r i e d i n v a c u o a t 70°G f o r s e v e r a l h o u r s . The c o m p l e x d i d n o t m e l t b e l o w 250°G n o r was i t s o l u b l e i n a w i d e r a n g e o f common s o l v e n t s . The a n a l y t i c a l d a t a a r e a s f o l l o w s : C 2 6 . 7 0 % H 2 . 5 9 % C l 4 . 5 % P 2 0 . 7 1 % S 1 4 . 1 1 % . I f i t i s a s s u m e d t h a t t h e r e m a i n i n g w e i g h t i s due s o l e l y t o r h o d i u m , t h e n t h e p e r c e n t a g e o f Rh i n t h e c o m p l e x i s 3 1 . 4 % . The a n a l y t i c a l d a t a c o r r e s p o n d n o t a t a l l w e l l t o a n y e x p e c t e d c o m p o s i t i o n . The e m p i r i c a l f o r m u l a w h i c h p r o v i d e s t h e c l o s e s t f i t i s R h 2 ( C l ) ( P h 3 P ) ( P ^ S 3 ) f o r w h i c h t h e f o l l o w i n g c o m p o s i t i o n i s e x p e c t e d : C 2 9 . 8 5 % , H 2.07%, C l 4.9%, P 1 9 . 2 8 % , S 1 3 . 2 7 % , Rh 2 8 . 4 7 % . - 4 4 -The i n f r a r e d s p e c t r u m o f t h i s b r o w n p r o d u c t e x h i b i t s c h a r a c t e r i s t i c p h e n y l a b s o r p t i o n a t 7 4 0 ( s ) , 7 2 0 ( m ) , 6 9 0 ( s ) , 5 1 7 ( s ) a n d 5 0 5 ( s h ) cm . T h e r e i s a l s o b r o a d u n r e s o l v e d _ -i a b s o r p t i o n o f medium i n t e n s i t y b e t w e e n 450 a n d 420 cm . T h e r e i s no e v i d e n c e o f R h - C l s t r e t c h i n g b u t t h i s v i b r a t i o n i s q u i t e weak a t 296 c m - 1 i n R h C l C P h ^ P ) ^ . B e c a u s e o f t h e v e r y d a r k c o l o u r o f t h e c o m p l e x , i t s Raman s p e c t r u m was v e r y weak b u t d i s t i n c t b a n d s w e r e s e e n a t 369 cm""1, 420 cm" 1, a n d 1 0 0 3 cm""1. The 1 0 0 3 cm~ 1 b a n d i s a p h e n y l r i n g v i b r a t i o n . B e c a u s e o f t h e u s u a l d i f f i -c u l t i e s i n v o l v e d i n w o r k w i t h t h e s e i n t r a c t a b l e comp-l e x e s , no f u r t h e r w o r k was d o n e on t h i s compound. R h B r ( P h 5 P ) 5 w i t h P ^ S 5 : A m i x t u r e o f R h B r C P h ^ P ) ^ ( 1 . 1 6 3 5 gms., 1.22 mmoles) a n d P4S.J ( 0 . 2 6 7 9 gms., 1.22 mmoles) w e r e h e a t e d u n d e r r e f l u x i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . A l m o s t i m m e d i a t e l y a d a r k b r o w n p r e c i p i t a t e f o r m e d . The p r o d u c t was c o l l e c t e d o n s i n t e r e d g l a s s a n d w a s h e d w i t h n u m e r o u s a l i q u o t s o f C S 2 i n w h i c h b o t h s t a r t i n g m a t e r i a l s a r e v e r y s o l u b l e . The compound was f o u n d t o s m e l l o f H^S u p o n p r o l o n g e d e x p o s u r e t o t h e a t m o s p h e r e . I t was t h e r e f o r e s t o r e d i n a n i t r o g e n a t m o s p h e r e b u t q u i c k m a n i p u l a t i o n s w e r e p e r f o r m e d i n t h e a i r . The c o m p l e x was c o m p l e t e l y i n s o l u b l e i n a l l s o l v e n t s t e s t e d a n d d i d n o t m e l t up t o 2 7 5 ° C I t was d r i e d i n v a c u o a t 70°C t o r e m o v e s o l v e n t a n d t h e f o l l o w i n g a n a l y t i c a l d a t a w e r e o b t a i n e d : - 4 5 -C 2 7 . 6 2 % H 2 . 2 5 % B r 1 0 . 5 5 % . A s s u m i n g t h a t t h i s c o m p l e x i s s i m i l a r t o t h e a n a l o g o u s c h l o r o - c o m p l e x , f o r w h i c h more c o m p l e t e a n a l y t i c a l d a t a a r e a v a i l a b l e , t h e n t h e e m p i r i c a l f o r m u l a R h 2 ( B r ) ( P h ^ P ) ( P ^ S ^ ) w o u l d r e q u i r e t h e f o l l o w i n g p r o p o r t i o n s : 0 2 8 . 1 3 % H 1 . 9 5 % B r 1 0 . 4 2 % . An i n f r a r e d s p e c t r u m i s v e r y s i m i l a r t o t h a t o f t h e c h l o r o - a n a l o g u e . A b s o r p t i o n i s s e e n a t 7 4 0 ( s ) , 7 2 0 ( m ) , 6 8 8 ( s ) , 5 1 7 ( s ) and 492(m) cm""1. I n a d d i t i o n t h e r e i s b r o a d u n r e s o l v e d a b s o r p t i o n o f medium i n t e n s i t y b e t w e e n 4 2 0 - 4 5 0 cm . B e c a u s e o f t h e d a r k b r o w n c o l o u r o f t h i s c o m p l e x , a Raman s p e c t r u m was o f l i m i t e d s u c c e s s . O n l y two r e l a t i v e l y b r o a d b e n d s c e n t r e d a t 366 a n d 420 cm" 1 w e r e s e e n ; t h e n o r m a l l y i n t e n s e p h e n y l r i n g v i b r a t i o n a t 1000 cm c o u l d n o t be s e e n . P t ( P h 5 P ) 4 w i t h P 4 S 5 : A m i x t u r e o f P^S^ ( 0 . 1 6 6 2 gms., 0.0755 mmoles) a n d P t ( P h 5 P ) 4 ( 0 . 9 4 5 3 gms., 0.0755 mmoles) was h e a t e d u n d e r r e f l u x o v e r n i g h t i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . A p a l e b r o w n p r e c i p i t a t e was f i l t e r e d o f f , w a s h e d w i t h c h l o r o f o r m a n d d r i e d i n v a c u o a t 80°C f o r t h i r t y m i n u t e s . T h i s m a t e r i a l d i d n o t m e l t up t o 255°C n o r was i t s o l u b l e i n a n y o f a w i d e r a n g e o f s o l v e n t s . C a r b o n a n d h y d r o g e n a n a l y s e s a r e a s f o l l o w s : C 2 8 . 4 7 % H 2.2%. I f one a s s u m e s t h a t p l a t i n u m r e m a i n s t e t r a c o o r d i n a t e , t h e n f o r s p e c i e s ( P h 5 ? ) 2 P t ( ? 4 S 5 ) 2 a n d ( P h 5 P ) P t ( P 4 S 5 ) 5 , t h e c a r b o n - 4 6 -a n d h y d r o g e n a n a l y s e s s h o u l d be G 3 7 . 2 7 % , H 2 . 5 9 % a n d C 1 9 . 3 4 % , H 1.34% r e s p e c t i v e l y . The p o s s i b i l i t y o f a t r i c o o r d i n a t e p l a t i n u m c o m p l e x c a n n o t be e x c l u d e d . The c o m p l e x ( P h ^ P j P t C P ^ S ^ ) 2 w o u l d be e x p e c t e d t o h a v e c a r b o n a n d h y d r o g e n a n a l y s e s o f 2 4 . 0 8 % a n d 1 . 6 7 % r e s p e c t i v e l y . I t i s a p p a r e n t t h a t n o n e o f t h e s e f o r m u l a t i o n s i s c o r r e c t f o r t h e e x p e r i m e n t a l a n a l y t i c a l d a t a . When P t ( P h ^ P ) 4 was r e a c t e d u n d e r s i m i l a r c o n d i t i o n s w i t h a n e x c e s s o f P „ S , 4 3 ( 1 : 5 m o l e r a t i o ) , a n i n t r a c t a b l e b r o w n c o m p l e x o f compo-s i t i o n 2 1 . 4 7% C a n d 2.46%H was i s o l a t e d . The i n f r a r e d s p e c t r a o f t h e two c o m p l e x e s w e r e i d e n t i c a l a n d a b s o r p t i o n b a n d s w e r e s e e n a t 7 4 4 ( m ) , 7 2 4 ( m ) , 6 9 0 ( s ) , 5 2 4 ( s ) , 5 0 9 ( m ) , 4 9 4 ( s h ) a n d 4 5 0 - 4 2 0 ( b r o a d ) cm" 1. A Raman s p e c t r u m o f t h e f i r s t c o m p l e x was o f p o o r q u a l i t y b u t t h e f o l l o w i n g p e a k s w e r e s e e n : 1 0 3 0 ( m ) , 1 0 0 2 ( s ) , -i 6 2 0 ( w ) , 414(w, b r o a d ) a n d 3 6 5 ( w , b r o a d ) cm . c i s - P t ( P B u 5 ) 2 C l 2 w i t h c i s - P t ( P B u 3 ) 2 C 1 Q was p r e p a r e d a c c o r d i n g t o l i t e r a t u r e 3 23 m e t h o d s ^ . I n a t y p i c a l r e a c t i o n , c i s - P t C P B u ^ ) Q C I Q ( 1 . 0 3 5 5 gms., 1.57 mmoles) a n d P^S^ ( 0 . 3 4 5 6 gms., 1.57 mmoles) were h e a t e d u n d e r r e f l u x i n b e n z e n e i n a n i t r o g e n a t m o s p h e r e . The c o l o u r o f t h e s o l u t i o n s l o w l y c h a n g e s f r o m a p a l e y e l l o w t o a c l e a r r e d - b r o w n s o l u t i o n . The s o l v e n t was t h e n r e m o v e d u n d e r r e d u c e d p r e s s u r e t o y i e l d a b r o w n o i l ; p r e c i p i t a t i o n was e f f e c t e d b y a d d i t i o n o f v e r y c o l d ( - 1 0 ° C ) e t h a n o l . The r e s u l t i n g p a l e b r o w n - 4 7 -p o w d e r was w a s h e d w i t h p e t e t h e r o r a c e t o n e a n d d r i e d i n v a c u o . Upon p r o l o n g e d e x p o s u r e t o a i r , t h e c o m p l e x was o b s e r v e d t o s m e l l o f H 2 S ; i t was t h e r e f o r e s t o r e d i n v a c u o b u t i n g e n e r a l f u r t h e r m a n i p u l a t i o n s w e r e c a r r i e d o u t i n t h e a i r . A t t e m p t s t o c r y s t a l l i z e t h e p r o d u c t b y s l o w e v a p o r a t i o n o f t h e f o l l o w i n g s o l v e n t s w e r e u n s u c c e s s f u l : b e n z e n e , c h l o r o f o r m / p e t r o l e u m e t h e r , c h l o r o f o r m / a c e t o n e , c h l o r o f o r m / e t h a n o l , c a r b o n d i s u l p h i d e / p e t r o l e u m e t h e r . The c o m p l e x i s v e r y s o l u b l e i n c h l o r o f o r m a n d c a r b o n d i s u l p h i d e , somewhat l e s s s o l u b l e i n b e n z e n e a n d i n s o l u b l e i n a l c o h o l s o r p e t r o -l e u m e t h e r . I t d o e s n o t m e l t up t o 275°G. A n a l y t i c a l r e s u l t s a r e a s f o l l o w s : C 1 7 . 1 4 % H 3 . 0 0 % C l 1 . 8 5 % P t ( P B u 3 ) ( P 4 S 3 ) 2 r e q u i r e s G 1 7 . 2 0 % H 3 . 2 2 % C l 0 A t t e m p t s t o r i d t h i s c o m p l e x o f i t s r e s i d u a l c h l o r i d e h a v e b e e n h i n d e r e d b y t h e f a c t t h a t i t i s s t r o n g l y a d s o r b e d b y s u c h common c o l u m n m a t e r i a l s a s f l o r i s i l a n d s i l i c a g e l . The c o m p l e x c o u l d n o t be f r e e d f r o m f l o r i s i l e v e n i n b o i l i n g c h l o r o f o r m . E x p e r i m e n t s a r e c o n t i n u i n g i n a n a t t e m p t t o p u r i f y t h i s i n t e r e s t i n g c o m p l e x . The f o l l o w i n g s p e c t r a l d a t a h a v e b e e n o b t a i n e d : 31 ( i ) n.m.r. A t t e m p t s t o o b t a i n a P n.m.r. s p e c t r u m w e r e u n s u c c e s s f u l . A "*"H n.m.r. s p e c t r u m e x h i b i t s m e t h y l r e s o n a n c e s c e n t r e d a t 1.0S a n d m e t h y l e n e r e s o n a n c e s c e n t r e d a t 1.6<8 . The r e l a t i v e i n t e n s i t i e s a r e 1:2 a s e x p e c t e d . The p r o t o n c h e m i c a l s h i f t s a r e i d e n t i c a l t o t h o s e s e e n i n - 4 8 -c i s - P t ( P B u ^ ) 2 C 1 2 * A P r o t o n s p e c t r u m s c a n n e d t o 4 3 T d i d n o t r e v e a l a n y r e s o n a n c e t h a t m i g h t he a t t r i b u t e d t o a p l a t i n u m h y d r i d e c o m p l e x . ( i i ) i n f r a r e d : A n u j o l m u l l o f P t ( P B u 5 ) ( P ^ S ^ ) 2 showed o n l y weak t o medium a b s o r p t i o n . B a n d s a s s o c i a t e d w i t h ? 4 S 5 w e r e s e e n a t 4 8 0 ( w ) , 4 3 8 ( m ) , 4 2 2 ( m ) , a n d 3 9 5 ( s h ) cm" . On t h e same P e r k i n - E l m e r 457 g r a t i n g s p e c t r o p h o t o m e t e r , t h e c o r r e s p o n d i n g b a n d s o f u n c o m p l e x e d P^S^ a r e s e e n a t 4 7 8 ( m ) , 4 3 4 ( s ) , 4 1 9 ( s ) a n d 3 9 5 ( s h ) cm" 1. No P t - C l s t r e t c h i n g was s e e n ; t h i s v i b r a t i o n i s v e r y e a s i l y s e e n i n b o t h c i s - a n d t r a n s - P t ( P B u ^ ) p C l ^ . ( i i i ) A Raman s p e c t r u m o f P t ( P B U j ) ( P ^ S ^ ) 2 was o b t a i n e d . The f o l l o w i n g b a n d s w e r e o b s e r v e d i n t h e r e g i o n 5 0 0-160 cm" 1: 4 8 8 ( w ) , 4 4 6 ( s ) , 345(m) a n d 290(m) cm . T h e s e c o r r e s p o n d t o Raman b a n d s a t 4 8 8 , 4 4 3 , 3 4 2 , a n d 288 cm" 1 i n u n c o m p l e x e d P^S^. A n a d d i t i o n a l b a n d a t 420 cm" 1 i s s e e n i n P t ( P B u ^ ) ( P ^ S ^ ) 2 b u t i t i s n o t s u f f i c i e n t l y s h a r p t o p e r m i t a n e x a c t e v a l u a t i o n . No b a n d s t h a t c o u l d be a s s i g n e d a s P t - P s t r e t c h i n g w e r e o b s e r v e d . P 4 S 5 I 2 w i t h A g S b P 6 : G - P ^ S ^ ^ was p r e p a r e d a s d e s c r i b e d i n t h e l i t e r a t u r e . A d r y b e n z e n e s o l u t i o n o f P^S^I/, ( 0 . 5 6 4 7 gms.., 1.20 mmoles) was p r e p a r e d a n d s o l i d A g S b F f i ( 0 . 8 1 9 2 gms., 2.40 m m o l e s ) - 4 9 -was a d d e d t o t h e s o l u t i o n u n d e r a n i t r o g e n a t m o s p h e r e . A n i m m e d i a t e p r e c i p i t a t i o n o c c u r r e d b u t t h e w e i g h t o f t h e p r e c i p i t a t e ( 0 . 8 1 4 6 gms.) was s i g n i f i c a n t l y more t h a n c o u l d c o r r e s p o n d s o l e l y t o f o r m a t i o n o f A g l ( 0 . 5 5 9 6 gms. maximum). An u n d e t e r m i n e d amount o f s h a r p - s m e l l i n g g a s was a l s o r e l e a s e d i n t h i s r e a c t i o n ; i n a d d i t i o n , a n i n -s o l u b l e o r a n g e p r o d u c t was i s o l a t e d . I t g a v e a p o s i t i v e t e s t f o r a n t i m o n y a f t e r t r e a t m e n t w i t h H C l a n d was t h e r e f o r e a s s u m e d t o be S b 2 S ^ . The l i b e r a t e d g a s was l i k e l y P F ^ a n d t o some d e g r e e HF. P . S XI„ w i t h N aBPh.: 4 5 2 4 a - P ^ I g ( 0 . 2 2 8 0 gms., 0.481 mmoles) a n d N a B P h ^ ( 0 . 1 6 3 9 gms., 0.96 m moles) w e r e s t i r r e d t o g e t h e r i n a 1:1 d r y s o l v e n t m i x t u r e o f b e n z e n e a n d a c e t o n i t r i l e u n d e r n i t r o g e n . I m m e d i a t e l y a w i n e - r e d s o l u t i o n r e s u l t e d . The m i x t u r e was h e a t e d u n d e r r e f l u x o v e r n i g h t a n d t h e n t h e s o l v e n t was r e m o v e d u n d e r r e d u c e d p r e s s u r e t o y i e l d a y e l l o w - o r a n g e p r o d u c t . The p r o d u c t was e x t r a c t e d w i t h C S 2 t o y i e l d p a l e y e l l o w c r y s t a l s whose m e l t i n g p o i n t (171-2°C) c o n f i r m e d t h a t t h e y w e r e P^S^. The m a t e r i a l w h i c h was n o t e x t r a c t e d b y C S 2 was f o u n d t o d i s s o l v e c o m p l e t e l y i n a c e t o n i t r i l e ; r e m o v a l o f a c e t o n i t r i l e g a v e a p a l e y e l l o w compound whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f N a B P h ^ e x c e p t f o r a f e w weak p e a k s . The i n i t i a l f o r m a t i o n o f a r e d s o l u t i o n i s a t t r i b u t e d t o l o s s o f m o l e c u l a r i o d i n e f r o m P^S.,1,,. - 5 0 -P 4 S 3 I 2 w i t h NaSCN: S o d i u m t h i o c y a n a t e was d r i e d i n v a c u o w i t h h e a t i n g p r i o r t o u s e . P ^ S ^ I ^ ( 0 . 4 7 5 0 gms., 1.0 mmoles) a n d d r y NaSCN ( 0 . 1 8 1 5 gms., 2.0 mmoles) w e r e s t i r r e d t o g e t h e r i n d r y 1:1 b e n z e n e a c e t o n i t r i l e i n a n i t r o g e n a t m o s p h e r e . A n i m m e d i a t e r e d s o l u t i o n f o r m e d . The p r e s e n c e o f f r e e I 2 was c o n f i r m e d u s i n g K l - s t a r c h p a p e r . The s o l v e n t m i x t u r e was r e m o v e d u n d e r r e d u c e d p r e s s u r e a n d e x t r a c t i o n o f t h e r e m a i n i n g s o l i d s w i t h G S 2 y i e l d i n g P ^ S ^ i d e n t i f i e d b y i t s m e l t i n g p o i n t 171-2°C. P 4 S 5 I 2 w i t h KCN: A m i x t u r e o f P ^ S 3 I 2 ( 0 . 3 3 6 8 gms., 0.71 mmoles) a n d KCN ( 0 . 0 1 9 0 gms., 1.42 mmoles) w e r e h e a t e d u n d e r r e f l u x i n d r y 1:1 b e n z e n e - a c e t o n i t r i l e i n a n i t r o g e n a t m o s p h e r e . I n i t i a l l y t h e s o l u t i o n t u r n e d d e e p r e d b u t a f t e r h a v i n g b e e n l e f t o v e r n i g h t , t h e s o l u t i o n was a p a l e y e l l o w c o l o u r . R e m o v a l o f s o l v e n t g a v e s o l i d m a t e r i a l f r o m w h i c h P^S^ (m.p. 172°C, s h a r p ) was e x t r a c t e d w i t h C S 2 . The r e m a i n i n g w h i t e p r o d u c t g a v e no i n f r a r e d s p e c t r u m i n d i c a t i n g t h a t i t was n o t KCN. I t was h o w e v e r w a t e r s o l u b l e a n d was o x i d i z e d b y a n a c i d i c i o d a t e s o l u t i o n t o y i e l d a s t r a w - b r o w n c o l o u r . The w h i t e p r o d u c t i s t h e r e f o r e a s s u m e d t o be K I , f o r m e d b y o x i d a t i o n o f c y a n i d e i o n b y m o l e c u l a r i o d i n e : I 2 + 2CN" > ( C N ) 2 + I " - 5 1 -P 4 S 5 I 2 w i t h M o ( C O ) 6 : ( i ) i n s o l u t i o n : P^S^ I g ( 0 . 1 6 5 6 gms., 0.35 m moles) a n d M o ( C 0 ) g ( 0 . 0 9 0 1 gms., 0.35 mmoles) w e r e m i x e d i n d e g a s s e d b e n z e n e a n d r e f l u x e d u n d e r n i t r o g e n o v e r n i g h t . A h e a v y b l a c k p r e c i p i t a t e h a d f o r m e d . No o t h e r s o l i d s c o u l d be i s o l a t e d f r o m t h e r e a c t i o n m i x t u r e . The l i k e l i h o o d o f d e c o m p o s i t i o n was s o g r e a t t h a t t h e r e a c t i o n was n o t p u r s u e d . ( i i ) m o l t e n : P 4 S 3 I 2 (°« 2587 gms., 0.50 mmoles) a n d M o ( C 0 ) g ( 0 . 1 3 1 7 gms., 0.50 mmoles) w e r e m e l t e d t o g e t h e r u n d e r a s l i g h t p r e s s u r e o f n i t r o g e n . A f t e r t w o h o u r s o n l y a s m a l l v o l u m e o f GO h a d b e e n r e l e a s e d and a s m a l l amount o f s o l i d i o d i n e h a d s u b l i m e d o u t o f t h e r e a c t i o n . I t w o u l d a p p e a r t h e r e f o r e t h a t d i s s o c i a t i o n o f P ^ S ^ ^ i s o c c u r r i n g f o l l o w e d b y s l o w d i s p l a c e m e n t o f CO w i t h P^S^. P 4 S 5 I 2 w i t h S b C l 5 : A s m a l l p o r t i o n o f P^S^ I r , was a d d e d t o a n e x c e s s o f S b C l ^ i n d r y C H 2 G 1 2 . A n e x o t h e r m i c r e a c t i o n was o b s e r v e d a n d t h e s o l u t i o n t u r n e d d a r k o r a n g e . C o n t i n u e d a d d i t i o n o f P^S^ I g g a v e a d a r k r e d s o l u t i o n a n d f o r m a t i o n o f w h i t e c r y s t a l s . The s o l u t i o n was t e s t e d w i t h K l - s t a r c h p a p e r a n d g a v e a s t r o n g p o s i t i v e t e s t f o r m o l e c u l a r i o d i n e . The w h i t e c r y s t a l s w e r e n o t i n v e s t i g a t e d b u t a r e u n d o u b t e d l y t h e same a s t h o s e o b t a i n e d f r o m t h e d e -c o m p o s i t i o n o f P,S, w i t h S b C l 5 ( a s s u m e d t o be P C l + S b C l g ) . - 5 2 -P 4 S 5 I 2 w i t h Hg: A s o l u t i o n o f P ^ S ^ ^ i n C S 2 was a d d e d t o a s m a l l amount o f s t i r r e d m e r c u r y . The r e a c t i o n was c o n t i n u e d o v e r n i g h t i n a n i t r o g e n a t m o s p h e r e a t r o o m t e m p e r a t u r e . A h e a v y b l a c k p r e c i p i t a t e h a d f o r m e d ; i t was i n s o l u b l e i n w a t e r , b u t was s o l u b l e i n c o n c e n t r a t e d a l k a l i a n d i n a q u a r e g i a . The m a t e r i a l i s u n d o u b t e d l y HgS. The r e a c t i o n s o l u t i o n was c o n c e n t r a t e d b y r e m o v a l o f s o l v e n t t o y i e l d a f o u l - s m e l l i n g y e l l o w o i l . P 4 S 5 I 2 w i t h I r C l ( C O ) ( P h 3 P ) 2 : P 4 S 5 I 2 ( 0 . 1 8 4 3 gms., 0.389 mmoles) a n d I r C l ( C O ) ( P h 5 ? ) 2 ( 0 . 3 0 2 8 gms., 0.389 mmoles) w e r e m i x e d t o g e t h e r i n b e n z e n e a n d a l l o w e d t o r e f l u x o v e r n i g h t u n d e r h e l i u m . A l m o s t i m m e d i a t e l y a n o r a n g e p r e c i p i t a t e f o r m e d ; a w o r k - u p o f t h e m o t h e r l i q u o r s r e v e a l e d t h a t t r i p h e n y l -p h o s p h i n e s u l p h i d e h a d f o r m e d ; i t was i d e n t i f i e d b y c o m p a r i s o n o f i t s i n f r a r e d s p e c t r u m w i t h t h a t o f a n a u t h e n t i c s a m p l e . The o r a n g e p r e c i p i t a t e was t h e r e f o r e n o t e x a m i n e d a s i t was o b v i o u s t h a t P ^ S ^ ^ h a d d e c o m p o s e d . A t t e m p t e d P o l a r o g r a p h y o f P ^ S ^ ^ : A 0.001 M s o l u t i o n o f P ^ S ^ ^ i n d r y 1:1 b e n z e n e -a c e t o n i t r i l e was p r e p a r e d . When s u f f i c i e n t t e t r a - n -b u t y l a m m o n i u m i o d i d e t o f o r m 0.1 M s o l u t i o n was a d d e d , t h e m i x t u r e t u r n e d a b r i g h t o r a n g e . N o n e t h e l e s s t h e s o l u t i o n was v i g o r o u s l y d e o x y g e n a t e d a n d a p o l a r o g r a m o f - 5 3 -t h e s o l u t i o n showed o n l y one wave a t - 0 . 9 5 v . i d e n t i c a l t o t h a t p r e v i o u s l y o b t a i n e d f o r P^S^. I t i s a p p a r e n t t h e r e f o r e t h a t P ^ S ^ ^ , u n d e r t h e i n f l u e n c e o f i o d i d e i o n , h a s d i s s o c i a t e d t o f o r m P^S^ a n d I^. The l i b e r a t e d i o d i n e c o m p l e x e s w i t h f r e e i o d i d e i o n t o f o r m t h e 1^ i o n a c c o u n t i n g f o r t h e i n i t i a l c o l o u r c h a n g e . - 5 4 -C. INFRARED & RAMAN SPECTRA OF P ^ S t r u c t u r a l m o b i l i t y i s a c h a r a c t e r i s t i c o f many o f t h e compounds whose c h e m i s t r y i s d e s c r i b e d i n t h i s t h e s i s , 33 The s t r u c t u r e o f P^S^ i n t h e s o l i d s t a t e i s known , b u t i t s c a g e s t r u c t u r e i s c h a n g e d u n d e r v e r y m i l d c o n d i t i o n s b y r e a c t i o n w i t h e l e m e n t a l s u l p h u r t o g i v e P ^ S ^ , a n d i t seemed p o s s i b l e t h a t t h e s t r u c t u r e o f P4S3 i t s e l f m i g h t n o t be t h e same i n s o l u t i o n a s i n t h e c r y s t a l . A s t u d y o f i t s v i b r a t i o n a l s p e c t r a i n t h e l i q u i d a n d s o l i d 34 p h a s e s was t h e r e f o r e u n d e r t a k e n . P r e v i o u s w o r k ( G e r d i n g , M a a r s e n , N o b e l ) h a d i n d e e d shown some d i f f e r -e n c e s b e t w e e n t h e s p e c t r a i n t h e s o l i d a n d i n C S 2 s o l u t i o n , a n d t h e i r w o r k d i d n o t e n t i r e l y a g r e e w i t h t h e 35 l a t e r i n f r a r e d r e s u l t s o f S t e g e r a n d B l e c h s c h m i d t . W h i l e t h e p r e s e n t w o r k was b e i n g c a r r i e d o u t , a more d e t a i l e d p a p e r ^ a p p e a r e d , w h i c h showed t h a t f o r t h e p h o s p h o r u s s u l p h i d e s P ^ S ^ , P ^ S y a n d P^S-^Q, s t r u c t u r a l c h a n g e s do i n d e e d t a k e p l a c e i n s o l u t i o n , p r o b a b l y t h r o u g h m i g r a t i o n o f s u l p h u r a t o m s i n P=S b o n d s . I n a g r e e m e n t w i t h t h e p r e s e n t w o r k , no s u c h m i g r a t i o n s w e r e d e t e c t e d i n P^S,, b u t t h e r e a r e some d i f f e r e n c e s b e t w e e n 4 3* t h e two s e t s o f r e s u l t s , w h i c h a r e r e p o r t e d i n d e t a i l b e l o w . EXPERIMENTAL: Comme r c i a l P^S^ was r e c r y s t a l l i z e d t w i c e f r o m t o l u e n e - 5 5 -u n d e r n i t r o g e n t o y i e l d p a l e y e l l o w c r y s t a l s , m.p. 1 7 1 -172°C ( l i t . 5 7 172-173°C). T h i s was t h e m a t e r i a l u s e d f o r r o u t i n e s p e c t r a . The s p e c t r a o b t a i n e d w i t h t h i s s a m p l e w e r e e n t i r e l y c o n s i s t e n t w i t h t h o s e o b t a i n e d f r o m a h i g h l y p u r i f i e d s a m p l e . To t e s t t h e h y p o t h e s i s t h a t c e r t a i n b a n d s w e r e due t o i m p u r i t i e s , a h i g h l y p u r i f i e d s a m p l e o f P^S^ was p r e p a r e d . P 4 S 3 was t w i c e r e -c r y s t a l l i z e d f r o m t o l u e n e u n d e r n i t r o g e n ; t h e s e c r y s t a l s w e r e g r o u n d t o a f i n e p o w d e r a n d t r e a t e d w i t h b o i l i n g d i s t i l l e d w a t e r f o r one h o u r t o r e m o v e h i g h e r s u l p h i d e s . T h i s p r o c e d u r e was a l s o c a r r i e d o u t u n d e r n i t r o g e n t o a v o i d a n y p o s s i b l e o x i d a t i o n . w a s t h e n c o l l e c t e d o n s i n t e r e d g l a s s a n d w a s h e d w i t h e t h a n o l a n d e t h e r . I t was s u b s e q u e n t l y r e c r y s t a l l i z e d f r o m b e n z e n e u n d e r n i t r o -g e n , p o w d e r e d a n d s u b l i m e d i n v a c u o a t 130°C. The c r y s t a l s w e r e c o l l e c t e d i n a n i t r o g e n a t m o s p h e r e , p o w d e r e d an d p l a c e d i n a Raman t u b e f i t t e d w i t h a B 10 j o i n t . A l l Raman s p e c t r a w e r e r e c o r d e d w i t h a C a r y 8 1 s p e c -t r o m e t e r u s i n g 6 3 2 8 A 0 e x c i t a t i o n f r o m a S p e c t r a P h y s i c s M o d e l 1 2 5 He-Ne c o n t i n u o u s g a s l a s e r . To o b t a i n a c c u r a t e d e p o l a r i z a t i o n r a t i o s , t h e i n s t r u m e n t was c a l i b r a t e d 38 u s i n g d e p o l a r i z a t i o n r a t i o s p r e v i o u s l y r e p o r t e d ^ f o r v a r i o u s b a n d s o f C S 2 , CH" 2C1 2 and C C l ^ . F r e s h l y p r e p a r e d s a t u r a t e d s o l u t i o n s o f P^S^ i n C S 2 w e r e f i l t e r e d p r i o r t o u s e i n t h e d e p o l a r i z a t i o n m e a s u r e m e n t s . - 5 6 -The i n f r a r e d s p e c t r u m o f P^S^ was r e c o r d e d b e t w e e n 625 an d 160 cm u s i n g a P e r k i n E l m e r M o d e l 310 i n f r a r e d s p e c t r o p h o t o m e t e r . The s p e c t r u m was o b t a i n e d i n t h e s o l i d s t a t e a s a n u j o l m u l l b e t w e e n p o l y t h e n e p l a t e s . R ESULTS; The r e s u l t s o b t a i n e d a r e g i v e n i n T a b l e I . . The i n f r a r e d s p e c t r u m i s weak a n d d o e s n o t e x t e n d a b o v e 488 cm . The m e a s u r e d s p e c t r u m a g r e e s w i t h t h a t o f S t e g e r a n d B l e c h s c h m i d t a s f a r a s t h e i r f r e q u e n c y r a n g e e x t e n d s , a n d w i t h t h a t o f G a r d n e r w i t h t h e e x c e p t i o n o f a p o s s i b l e i . r . b a n d a t 185 cm , w h i c h G a r d n e r r e p o r t s a s s t r o n g i n a K B r d i s c . T h e r e a r e s e v e r a l d i f f e r e n c e s b e t w e e n t h e p r e s e n t Raman r e s u l t s a n d t h o s e i n t h e l i t e r a t u r e . 1) The weak b a n d r e p o r t e d b y G e r d i n g e t a l . a t 109 cm was n o t o b s e r v e d , p o s s i b l y b e c a u s e i t was o b s c u r e d b y R a y l e i g h s c a t t e r i n g . 2) The b a n d a t 146 cm" 1 i n t h e s o l i d i s a f f e c t e d b y R a y l e i g h s c a t t e r i n g , b u t a p p e a r s t o be o f m o d e r a t e i n t e n s i t y , n o t weak a s r e p o r t e d b y G a r d n e r . 3) G a r d n e r s u g g e s t s t h a t t h e b a n d s a t 371 cm i n t h e _ i Raman a n d 390 cm i n t h e i n f r a r e d a r e due t o i m p u r i t i e s . H o w e v e r , t h e s e l i n e s a p p e a r c l e a r l y i n t h e s p e c t r a o f b o t h n o r m a l l y a n d h i g h l y p u r i f i e d s a m p l e s , a t t h e same i n t e n s i t i e s , t h o u g h p u r i f i c a t i o n s h a r p e n s t h e b a n d s . -1 G a r d n e r was a b l e t o d e t e r m i n e t h a t t h e b a n d a t 187 cm TABLE S y m m e t r y I n f r a r e d M e l t S p e c i e s S p e c t r u m E A 1 1 8 5 ( v w ) ? E 2 2 1 ( s ) 224 E 287(mw) 288 E 341(mw) 341 E 3 9 0 ( s h ) ? A 1 4 1 9 ( a ) A 1 4 3 5 ( s ) 445 A 1 478(m) 486 w - weak m - medium s - s t r o n g s h - s h o u l d e r p - d e p o l a r i z a t i o n r a t i o ( i n cm""1) Raman C S 2 S o l i d A s s i g n m e n t s o l u t i o n (P) ( i n t e n s i t y ) 8 146 ( 1 . 6 ) V1Q 184 ( 0 . 2 ) V 224 ( 0 . 7 2 ) 219 ( 1 . 0 ) ^ 288 ( 0 . 7 3 ) 288 ( 2 . 4 ) \ 342 ( 0 . 6 8 ) |J|.(4.5)  V l HI ( 0 . 0 4 5 )  ve 424 ( 0 . 2 5 ) 421 ( 2 . 3 ) ^ 3 445 ( 0 . 1 8 ) 443 ( 1 0 ) ^ 2 488 ( 0 . 3 3 ) 488 ( 2 . 1 ) ^ 627 Vn + V4 681 2Vr] 730 V2 + VQ 765 V ^ + Vrj 7 8 1 V 2 + V 812 V2 + 371 o r ^ 3 + 391 825 V ^ + L> 845 2 2 ^ 865 V2 +  VJ> 968 21^ - 5 8 -i s p o l a r i z e d . P o l a r i z a t i o n measurements are otherwise i n agreement. For the symmetry group C 3 v , the fundamental v i b r a t i o n s of P^S^ are expected to be of species 4A 1 + A 2 + 5E. The A 2 v i b r a t i o n (antisymmetric torsion) i s in a c t i v e i n both i n f r a r e d and Raman. The others are a l l a c t i v e , the A^ v i b r a t i o n s being p o l a r i z e d . There i s no doubt that the three bands of highest frequency are pola r i z e d , and are three of the A^ bands. The fourth (by Gardner's r e s u l t s ) i s at 184 cm . The assignment of the bands at 224, 288 and 342 cm"1 (CS 2 solution) i s equally c e r t a i n , not only because of t h e i r p o l a r i -zations, but also because the f i r s t and t h i r d are s p l i t i n the s o l i d (219/225 and 342/346 cm*"1) probably as a r e s u l t of the low s i t e symmetry ( c s ) - -he assignment of the band of lowest frequency i s l e s s c e r t a i n . ' Since i t s i n t e n s i t y i s "moderate" i t i s u n l i k e l y to be the A 2 v i b r a t i o n made a c t i v e by l o c a l i n t e r a c t i o n s , and such a v i b r a t i o n i s u n l i k e l y to occur at higher frequen-c i e s . The observed band i s therefore l i k e l y to be "of species E. The assignment of the two l i n e s at 371/390 cm""1 as fundamentals i s confirmed by the appearance of a — 1 weak combination-band at 812 cm , which can only be described i n terms of one of these weak bands. I t i s perhaps s i g n i f i c a n t that Gerding reported weak Raman absorption at 384 cm""1, intermediate between 371 and. 390 cm"1, and these two bands are here assigned to the f i f t h E mode, resolved i n the s o l i d i n t o A'- and A'' c o m p o n e n t s . T h i s e x p l a n a t i o n o b v i a t e s t h e n e e d t o assume _ -i a c c i d e n t a l o v e r l a p o f A and E modes i n t h e 488 cm b a n d a s G a r d n e r d o e s ; no s p l i t t i n g c o u l d be d e t e c t e d i n t h i s _ -t b a n d e v e n u n d e r t h e h i g h e s t r e s o l u t i o n ( 0 . 5 cm ) . The s y m m e t r y s p e c i e s seem t h e r e f o r e t o be s a t i s f a c t o r i l y a s s i g n e d , a n d t h e s t r u c t u r e o f t h e P ^ ^ c a g e i s t h e r e -f o r e u n c h a n g e d when i t i s m e l t e d o r d i s s o l v e d . A l l o c a t i o n o f t h e f r e q u e n c i e s t o p a r t i c u l a r a t o m i c m o t i o n s i s d i f f i c u l t , b e c a u s e t h e a n g u l a r i n t e r n a l c o -o r d i n a t e s h a v e no c l e a r m e a n i n g i n a s m a l l c a g e m o l e c u l e . H o w e v e r some q u a l i t a t i v e c o n c l u s i o n s seem p o s s i b l e . The b a n d a t 488 cm i s c o n s i d e r e d t o be p o l a r i z e d a n d i s a s s i g n e d a s s y m m e t r i c P-P s t r e t c h i n g . I t i s l o g i c a l t h a t t h i s v i b r a t i o n s h o u l d o c c u r a t t h e h i g h e s t f r e q u e n c y ; m o r e o v e r , i t g i v e s a v a l u e i n g o o d a g r e e m e n t w i t h P-P s t r e t c h i n g f r e q u e n c i e s d e r i v e d f o r o t h e r compounds w h i c h f o r m p a r t o f t h i s t h e s i s . T h e s e i n c l u d e a v a l u e o f 504 cm" 1 i n P h 2 P 2 I 2 , 478 cm" 1 i n ( p - F C 6 H 4 P I ) 2 , 489 cm" 1 i n ( m - F C 6 H 4 P I ) 2 , 476 cm" 1 i n ( p - P C 6 H 4 P ) n . m i t e p h o s p h o r u s e x h i b i t s i n f r a r e d a b s o r p t i o n a t 465 cm" 1. The t o t a l l y s y m m e t r i c v i b r a t i o n s a t 443 a n d 421 cm a r e a s s i g n e d a s s y m m e t r i c P-S s t r e t c h i n g . The r e m a i n i n g t o t a l l y s y m m e t r i c v i b r a t i o n , a s s i g n e d b y G a r d n e r t o t h e _ -i weak 184 cm b a n d , c a n be c o n s i d e r e d a s a s y m m e t r i c a l d e f o r m a t i o n o f t h e a p i c a l p h o s p h o r u s . The t h r e e E v i b r a t i o n s i n v o l v i n g P-P a n d P-S s t r e t c h i n g a r e c o n -- 6 0 -s i d e r e d t o be t h o s e a t 3 9 0 / 3 7 1 cm" 1, 3 4 6 / 3 4 2 cm" 1 a n d 288 cm" 1. The v e r y s t r o n g d e g e n e r a t e v i b r a t i o n a t 342 cm i s m o s t l i k e l y due t o a s y m m e t r i c P-S s t r e t c h i n g . The l o w e r f r e q u e n c y v i b r a t i o n s a t 225/219 cm" - 1 a n d 142 _ i cm r e p r e s e n t a s y m m e t r i c d e f o r m a t i o n s . - 6 1 -I I . D I S C U S S I O N T e t r a p h o s p h o r u s t r i s u l p h i d e h a s b e e n s u b j e c t e d t o a w i d e v a r i e t y o f c h e m i c a l and s p e c t r o s c o p i c t e s t s . P4S3 h a s b e e n shown t o be a t m o s t v e r y w e a k l y b a s i c ; i t c a n n o t be p r o t o n a t e d b y s t r o n g n o n - o x i d i z i n g a c i d s a n d i s d e -c o m posed b y s t r o n g o x i d i z i n g a c i d s . c a n n o t be q u a t e r -n i z e d w i t h s t r o n g a l k y l a t i n g a g e n t s and d o e s n o t c o m p l e x w i t h s u c h p o w e r f u l ( J - a c c e p t o r s a s B F ^ a n d B C l ^ . T h e s e e x p e r i m e n t s i l l u s t r a t e f o r c e f u l l y t h a t P4S.J i s a p o o r CT - d o n o r w i t h r e s p e c t t o s p e c i e s t h a t c a n a c t o n l y a s 0 " - a c c e p t o r s . The v e r y weak b a s i c i t y o f P^S^ i s i l l u s -t r a t e d s t r i k i n g l y i n t h e a t t e m p t t o p e r f o r m a p o l a r o -g r a p h i c r e d u c t i o n o f d - P ^ S ^ . The f a c t t h a t C l - P ^ S . ^ i s d e c o m p o s e d t o P^S^ a n d l"J" b y i o d i d e i o n i n d i c a t e s t h a t I"* i s a s t r o n g e r b a s e t o w a r d s i o d i n e t h a n i s P 4 S 3 . C o n s i d e r i n g t h a t t h e h e a t o f f o r m a t i o n o f 1^*, a s d e t e r -4.7 m i n e d ' b y p a r t i t i o n e x p e r i m e n t s w i t h w a t e r a n d c a r b o n t e t r a c h l o r i d e , i s o n l y -4.34 K c a l / m o l e , t h e n i t i s a p p a r e n t t h a t P^S^ i s a v e r y weak b a s e i n d e e d . A l t h o u g h P ^ S 5 i s t h e r m a l l y s t a b l e a t 190°C, i t i s n o n e t h e l e s s v e r y s e n s i t i v e t o b o t h o x i d a t i v e a n d r e d u c t i v e s t r e s s . W h i l e i t i s p e r h a p s n o t s u r p r i s i n g t h a t P^S^ i s d e c o m p o s e d b y s u c h s t r o n g o x i d a n t s a s SO^, S b F ^ , S b C l ^ , A s F ^ a n d NgO^, i t i s r e m a r k a b l e t h a t s u c h a weak o x i d a n t a s d i m e t h y l s u l p h o x i d e c a n e x e r t a s i m i l a r e f f e c t . I t i s c h a r a c t e r i s t i c o f e l e m e n t a l s u l p h u r t h a t d e s p i t e i t s - 6 2 -p r o f u s i o n o f f o r m a l l y u n s h a r e d e l e c t r o n s , t h e S Q r i n g i s m a i n l y s u s c e p t i b l e t o n u c l e o p h i l i c a t t a c k . The f a c t t h a t a q u e o u s c y a n i d e a n d t r i p h e n y l p h o s p h i n e c a n s l o w l y a t t a c k P^S^ i n d i c a t e s s i m i l a r p r o p e r t i e s i n t h e c a g e . The p o l a r o -g r a p h i c e x p e r i m e n t s h a v e b e e n i n t e r p r e t e d t o g i v e a n i n d i -c a t i o n o f t h e s t a b i l i t y o f t h e P^S^ c a g e t o w a r d r e d u c t i o n . The p o l a r o g r a p h i c wave a t - 0 . 9 5 v . i s c o n s i d e r e d t o i n v o l v e a t w o - e l e c t r o n r e d u c t i o n o f P^S^ r e s u l t i n g i n c l e a v a g e o f a P-P b o n d . O t h e r w o r k e r s ^ 8 h a v e e x a m i n e d a v a r i e t y o f compounds c o n t a i n i n g P-P b o n d s , i n c l u d i n g c y c l o p o l y p h o s p h i n e s , d i p h o s p h i n e s , d i p h o s p h i n e mono-s u l p h i d e s a n d d i p h o s p h i n e d i s u l p h i d e s . I n a l l c a s e s a t w o - e l e c t r o n i r r e v e r s i b l e r e d u c t i o n o c c u r s a n d a P-P b o n d i s c l e a v e d . A l l compounds e x a m i n e d w e r e o b s e r v e d t o e x h i b i t w a v e s i n t h e r e g i o n -1.5 t o -2.5 v o l t s , f o r e x a m p l e , P h 5 P 5 - 1 . 7 2 5 v . , P h 4 P 2 - 2 . 0 5 0 v . , P h 4 P 2 S 2 - 1 . 7 9 5 v . , M e 4 P 2 S 2 - 2 . 4 8 0 v . A s P^S^ e x h i b i t s o n l y one wave i n t h e r e g i o n - 0 . 5 t o - 2 . 5 v . , t h i s wave i s c o n s i d e r e d t o be due t o P-P c l e a v a g e . The v e r y l o w v a l u e o f - 0 . 9 5 v . i l l u s t r a t e s t h e e a s e w i t h w h i c h t h e P^ r i n g c a n be b r o k e n . A l t h o u g h i t c a n n o t be s a i d w i t h c o m p l e t e c e r t a i n t y f r o m t h e s i m p l e e x p e r i m e n t s p e r f o r m e d t h a t r e d u c t i o n o f P^S^ i n v o l v e s c l e a v a g e o f t h e P^ r i n g , t h e w e i g h t o f e v i d e n c e f a v o u r s t h i s e x p l a n a t i o n ; t h e f a i l u r e t o o b s e r v e a n e . s . r . s p e c t r u m i s a l s o i n a g r e e m e n t w i t h s u c h a t w o - e l e c t r o n r e d u c t i o n . I n g e n e r a l t h e r e f o r e , P^S^ i s s t a b l e w i t h i n f a i r l y n a r r o w l i m i t s a s d e f i n e d b y o x i d a t i o n a n d r e d u c t i o n . - 6 3 -I n v i e w o f r e s u l t s t h a t P,S, h a s b e e n shown t o be a 4 5 p o o r C T - d o n o r , i t i s n o t s u r p r i s i n g t h a t P^S^ d o e s n o t c o m p l e x w i t h m e t a l s o f r a t h e r h i g h e f f e c t i v e n u c l e a r c h a r g e s u c h a s V O ( a c a c ) 2 and S b C l ^ . I n t h e s e t y p e s o f m e t a l c o m p l e x e s , t h e p o s s i b i l i t y o f s y n e r g i s t i c e f f e c t s i s g r e a t l y r e d u c e d . The i m p o r t a n c e o f s u c h e f f e c t s i s i l l u s -t r a t e d b y t h e f a c t t h a t P^S^ i s f o u n d t o r e a c t w i t h e v e r y G r o u p V I I I m e t a l c o m p l e x t e s t e d . I n t h e s e c o m p l e x e s , t h e m e t a l i s i n a l o w - o r z e r o - v a l e n t o x i d a t i o n s t a t e a n d s o t h e r e i s a m p l e o p p o r t u n i t y f o r 7 7 " - b a c k - d o n a t i o n f r o m f i l l e d m e t a l d - o r b i t a l s t o u n f i l l e d 7 7 " - o r b i t a l s i n P^S^. The i r i d i u m c o m p l e x i s o l a t e d , I r C l 2 ( H ) ( G O ) ( P h ^ P ) ( P ^ S ^ ) , e x h i b i t s a C=0 s t r e t c h a t 2045 cm w h e r e a s t h a t o f t h e a n a l o g o u s c o m p l e x I r C l 2 ( H ) ( G O ) ( P h ^ P ) ^ i s f o u n d a t 2024 cm" 1. The s h i f t o f t h e C=0 s t r e t c h i n g v i b r a t i o n t o a h i g h e r f r e q u e n c y i m p l i e s t h a t P^S^ i s a s t r o n g e r 77-a c c e p t o r t h a n i s P h ^ P . The i m p o r t a n c e o f d o n o r - a c c e p t o r i n t e r a c t i o n s i s s u p p o r t e d b y t h e e a r l i e r w o r k o f N i x o n a n d c o l l e a g u e s ^: P^S^ was f o u n d t o f o r m m e t a l c a r b o n y l c o m p l e x e s o f t h e t y p e c i s - C P ^ S ^ ) 2 M o ( G 0 ) ^ [M=Cr,Mo,w] a n d c i s - ( P 4 S 5 ) 3 M ' ( C O ) 5 [M»=0r,Mo] . The C=0 s t r e t c h i n g f r e -q u e n c i e s o f t h e s e c o m p l e x e s l i e b e t w e e n t h o s e q u o t e d f o r 50 t h e r e l a t e d P ( 0 M e ) 3 and P C l ^ compounds , s u b s t a n t i a t i n g t h e a r g u m e n t t h a t P^S^ i s a s t r o n g 7 7 " - a c c e p t o r . The f o r m a t i o n a n d s t a b i l i t y o f P t ( P B u 3 ) ( P ^ S ^ ) 2 i s a l s o a g o o d i n d i c a t i o n o f t h e a c c e p t o r p r o p e r t i e s o f I ^ S ^ . T n e w e l l -known-' s t r o n g 7 7 - a c c e p t o r p r o p e r t i e s o f P F , a p p a r e n t l y - 6 4 -s t a b i l i z e P t ( 0 ) t o t h e e x t e n t t h a t t r e a t m e n t o f P t C l 2 w i t h h i g h p r e s s u r e s o f P F ^ r e s u l t s i n r e d u c t i o n o f P t ( I I ) a n d f o r m a t i o n 5 2 o f P t ( P F 5 ) ^ a n d C 1 2 P F 5 . S i m i l a r l y t h e a c c e p -t o r p r o p e r t i e s o f P^S^ a r e f o u n d t o s t a b i l i z e P t ( 0 ) t o t h e e x t e n t t h a t c i s - P t ( P B u 5 ) 2 G 1 2 i s r e d u c e d t o P t ( P B u 5 ) ( P 4 S 5 ) 2 , p r e s u m a b l y w i t h s i m u l t a n e o u s f o r m a t i o n o f C l ^ B u ^ a l t h o u g h no a t t e m p t s w e r e made t o i s o l a t e t h i s b y p r o d u c t . S e v e r a l t r i c o o r d i n a t e c o m p l e x e s o f p l a t i n u m ( 0 ) a r e known i n c l u -d i n g P t ( P h 5 P ) 3 , P t ( M e P P h 2 ) 3 5 4 a n d P t ( P E t 3 ) 3 5 9 . The com-p l e x e s c o n t a i n i n g t r i a r y l p h o s p h i n e s a r e s i g n i f i c a n t l y more s t a b l e t h a n t h e c o m p l e x o f t r i e t h y l p h o s p h i n e . T r i s ( t r i e t h y l p h o s p h i n e ) p l a t i n u m ( 0 ) i s a n e x t r a o r d i n a r i l y s t r o n g n u c l e o p h i l e a n d i s known t o u n d e r g o a d d i t i o n r e a c -t i o n s w i t h PhCN and P h C l , i n c o n t r a s t t o P t ( P P h 3 ) 3 . P t ( P E t 3 ) 3 w i l l a l s o e x t r a c t p r o t o n s f r o m w a t e r o r e t h a n o l t o f o r m t h e c a t i o n i c s p e c i e s |~H P t ( P E t 3 ) 3 j + . No r i g o r o u s • e x p e r i m e n t s h a v e b e e n p e r f o r m e d w i t h P t ( P B u 3 ) ( P ^ S ^ ) 2 , b u t i t i s known t h a t t h i s c o m p l e x i s s t a b l e t o e t h a n o l a n d t h a t i t i s v e r y s l o w t o d e c o m p o s e i n m o i s t a i r ; m o r e o v e r , t h e s m e l l o f H 2S d e t e c t e d i n d i c a t e s t h a t t h e c a u s e o f d e -c o m p o s i t i o n may w e l l be h y d r o l y s i s o f P ^ S j . I t i s a p p a r e n t t h e r e f o r e t h a t P t ( P B u 3 ) ( P ^ S ^ ) 2 more c l o s e l y r e s e m b l e s t h e P t ( P P h 3 ) 3 c o m p l e x , i n w h i c h i n c r e a s e d 7 7 " - b a c k - d o n a t i o n f r o m p l a t i n u m t o p h o s p h o r u s d e c r e a s e s c h e m i c a l r e a c t i v i t y a t t h e m e t a l s i t e . The c r y s t a l s t r u c t u r e 5 * * o f P t C P P h ^ ) ^ c o n f i r m s t h a t 7 7-bonding o c c u r s b e t w e e n p l a t i n u m a n d p h o s -p h o r u s ; t h e r e p o r t e d P t - P b o n d l e n g t h o f 2'26A° i s 0»16A° -65-s h o r t e r t h a n t h e sum o f t h e c o v a l e n t r a d i i o f p l a t i n u m a n d 57 p h o s p h o r u s . A v e r y r e c e n t c r y s t a l s t r u c t u r e o f t h e com-p l e x P^S^MoCCO)^ i n d i c a t e s t h a t m e t a l - p h o s p h o r u s 77"-"bonding i s i m p o r t a n t i n t h i s c o m p l e x a l s o . The Mo-P b o n d l e n g t h o f 2 . 4 7 7 ( 6 ) A 0 i s s h o r t e r t h a n t h e m a j o r i t y o f m o l y b d e n u m -57 p h o s p h o r u s b o n d d i s t a n c e s w h i c h h a v e b e e n r e p o r t e d , a n d 0 . 2 3 A 0 s h o r t e r t h a n t h e sum o f t h e c o v a l e n t r a d i i o f Mo 58 a n d P . A s m i g h t be e x p e c t e d , t h e e f f e c t o f Mo-P 7 7 -b o n d i n g i s s e e n a l s o i n t h e Mo-C b o n d l e n g t h s , w h i c h a t 2.06(2)A° a r e l o n g e r t h a n t h e d i s t a n c e s u s u a l l y f o u n d i n s u b s t i t u t e d c a r b o n y l s , b u t a r e e q u a l t o t h e a v e r a g e v a l u e s f o u n d i n M o ( C O ) 6 5 9 a n d i n M o ( C O ) 5 P P 3 6 0 . To p l a c e P-S-r w i t h i n a w i d e r c h e m i c a l p e r s p e c t i v e , i t i s u s e f u l t o c o m p a r e a n d c o n t r a s t P^S^ w i t h m o l e c u l e s w h i c h i t a p p e a r s t o r e s e m b l e e i t h e r s t r u c t u r a l l y o r chem-29 57 i c a l l y . O t h e r w o r k e r s ' h a v e s h o w n t h a t , i n t h e com-p l e x e s e x a m i n e d t o d a t e , P^S^ p r e f e r s t o b o n d t h r o u g h t h e a p i c a l p h o s p h o r u s a t o m . The s t e r e o c h e m i s t r y a t t h i s a p i c a l p h o s p h o r u s i s i l l u s t r a t e d b e l o w , a l o n g w i t h s i m i l a r d a t a f o r P.O^ a n d P F , . 4 U 6 y Ref. 33 Ref. 61 Ref. 62 - 6 6 -The c o n f i g u r a t i o n a t t h e c o o r d i n a t i n g p h o s p h o r u s a t o m s a r e v e r y s i m i l a r a n d n e i t h e r P^S^ n o r P^Og h a s a n y s u b s t i -t u e n t s s o t h a t s t e r i c e f f e c t s s h o u l d be m i n i m i z e d . A c o m p a r i s o n o f t h e d o n o r a n d a c c e p t o r p r o p e r t i e s o f t h e s e t h r e e compounds s h o u l d p r o v e u s e f u l i n a t t e m p t i n g t o d e c i d e w h a t f a c t o r s a r e i m p o r t a n t i n t h e b o n d i n g o f P^S^. The c h e m i s t r y o f t h e c a g e m o l e c u l e P^Og h a s n o t b e e n s t u d i e d t o a g r e a t d e g r e e , b u t i t h a s b e e n shown t o p o s s e s s q u i t e s t r o n g d o n o r p r o p e r t i e s . F o r e x a m p l e , t h e r e a c t i o n o f P^Og w i t h d i b o r a n e i n s o l u t i o n ^ r e s u l t s i n f o r m a t i o n o f c r y s t a l l i n e c o m p l e x e s P ^ O g ^ B H ^ an d P ^ O g ^ B H ^ . I n a d d -i t i o n t h e r e i s e v i d e n c e p r e s e n t e d f o r t h e e x i s t e n c e o f I > 4 0 6 " 4 B H 3 i n s ° l u t i o n . P/jOg w i l l r e a c t w i t h a n e x c e s s o f N i ( C O ) 4 t o p r o d u c e P 4 O g « 4 N i ( G O ) 5 w i t h i n t e n m i n u t e s 6 4 ; i n t h i s c o m p l e x a l l f o u r p h o s p h o r u s a t o m s a r e c o o r d i n a t e d t o N i ( C O ) 5 m o i t i e s . The r e a c t i o n o f P 4 0 g w i t h B F ^ ' E t p O r e s u l t s i n d e c o m p o s i t i o n and s u c h p r o d u c t s a s P F ^ , P F 2 O P F 2 a n d P F 2 O E t c a n be i s o l a t e d 6 5 . A l t h o u g h i n f o r m -a t i o n i s l i m i t e d w i t h r e s p e c t t o c o o r d i n a t i o n o f P^Og, many p a p e r s h a v e b e e n p u b l i s h e d a b o u t t h e c h e m i s t r y o f t h e c a g e b i c y c l o p h o s p h i t e s , 4 - m e t h y l - 2 , 6 , 7 - t r i o x a - l -p h o s p h a b i c y c l o [ 2 . 2 . 2 ] o c t a n e 6 6 ( L ) a n d 2 , 8 , 9 - t r i o x a - l -67 p h o s p h a a d a m a n t a n e ( L ' ) . A l t h o u g h t h e c r y s t a l s t r u c -t u r e s o f t h e s e m o l e c u l e s h a v e n o t b e e n d e t e r m i n e d , i t i s u n l i k e l y t h a t t h e c o n f i g u r a t i o n a t p h o s p h o r u s i s v a s t l y d i f f e r e n t f r o m t h a t f o u n d i n P 4 O 5 . - 6 7 -Compounds L a n d I ' e x h i b i t v e r y s t r i k i n g d o n o r p r o p e r t i e s . 6 R L w i l l f o r m c o m p l e x e s w i t h BH^, B^H^, BMe^ a n d B F ^ ; i n a d d i t i o n , i t t e n d s t o b r i n g o u t t h e maximum c o o r d i n a t i o n 6 9 n u m b e r i n m e t a l s . V a r i o u s e x a m p l e s i n c l u d e L ^ C u C l O ^ , L 4 A g C 1 0 4 6 9 , C o L 6 ( C 1 0 4 ) 3 7 0 and CoL-ClC^ 7 0. Although L I s n o t s u f f i c i e n t l y b a s i c t o d i s p l a c e t r i r a e t h y l a m i n e f r o m 67 i t s b o r a n e a d d u c t , L 1 h a s b e e n shown t o be c a p a b l e o f d o i n g s o . The h i g h r e a c t i v i t y o f t h e s e b i c y c l o p h o s p h i t e s 66 h a s b e e n a t t r i b u t e d t o t h e i r m i n i m a l s t e r i c h i n d r a n c e , t h e i r h i g h s y m m e t r y a n d t h e i n c r e a s e d a v a i l a b i l i t y o f t h e p h o s p h o r u s l o n e p a i r e l e c t r o n s . E v e n t h o u g h t h e r e a p p e a r s t o be no r e a s o n , o n g e o m e t r i c a l c o n s i d e r a t i o n s , why t h e s e f a c t o r s s h o u l d be s u b s t a n t i a l l y c h a n g e d i n P^S^* t h e d i v e r s i t y o f t h i s w o r k h a s i l l u s t r a t e d t h a t d o n o r p r o p e r t i e s o f P^S^ a r e s t r i k i n g l y d i f f e r e n t f r o m t h o s e o f t h e b i c y c l o p h o s p h i t e s L a n d L ' . - 6 8 -On t h e b a s i s o f e l e c t r o n e g a t i v i t i e s , t h e p h o s p h o r u s a t o m s i n P^S^ a r e e x p e c t e d t o be much more b a s i c t h a n t h e p h o s p h o r u s a t o m s i n P^Og o r i n t h e c o n s t r a i n e d b i c y c l o p h -o s p h i t e s . The r e d u c e d p o l a r i t y o f t h e P-S b o n d w i t h r e s p e c t t o P-0 b o n d s i s i l l u s t r a t e d , f o r e x a m p l e , b y t h e g e n e r a l l y weak i n f r a r e d a b s o r p t i o n o f P^S^; a t t h e same t i m e , t h e i n c r e a s e d p o l a r i z a b i l i t y r e s u l t s i n e x t r e m e l y s t r o n g Raman a b s o r p t i o n . F u r t h e r p r o o f o f r e d u c e d p o l a r -i t y c a n be f u r n i s h e d b y c o m p a r i s o n o f t h e r e a c t i o n s o f P^Og a n d P^S^ w i t h w a t e r ; P^Og i s i n s t a n t l y d e c o m p o s e d b y c o l d w a t e r w i t h q u a n t i t a t i v e p r o d u c t i o n o f H^PO^; o n t h e o t h e r h a n d , P^S^ i s o n l y v e r y s l o w l y d e c o m p o s e d b y b o i l i n g w a t e r . D e s p i t e t h e f a c t t h a t s u l p h u r i s much l e s s e l e c t r o n e g a t i v e t h a n o x y g e n , t h e r e i s no e v i d e n c e o f i n c r e a s e d b a s i c i t y a t p h o s p h o r u s . I n f a c t q u i t e t h e r e v e r s e i s o b s e r v e d : P^S^ h a s c o n s i d e r a b l y p o o r e r d o n o r p r o p e r t i e s t h a n , f o r e x a m p l e , t h e c o n s t r a i n e d b i c y c l o -p h o s p h i t e s . The m o s t r e a s o n a b l e e x p l a n a t i o n o f t h e p r o p e r t i e s o f t h e P^S^ c a g e w o u l d a p p e a r t o i n v o l v e p o s t u l a t i o n o f s i g n i f i c a n t 7 7"-bonding b e t w e e n p h o s p h o r u s a n d s u l p h u r , r e s u l t i n g i n p a r t i a l d e a c t i v a t i o n o f t h e p h o s p h o r u s l o n e p a i r s n o r m a l l y u s e d f o r C-donation. T r i v a l e n t p h o s p h o r u s h a s b e e n shown i n t h i s w o r k 71 ( v i d e i n f r a ) a n d i n p r e v i o u s w o r k ' t o be c a p a b l e o f 77"-d o n a t i o n t o i t s s u b s t i t u e n t s i n compounds w h e r e ( i ) s u b -s t i t u e n t a t o m s o r g r o u p s a r e c a p a b l e o f 7 7 * - a c c e p t a n c e , -69-and w h e r e ( i i ) s u b s t i t u e n t a t o m s o r g r o u p s c a p a b l e o f 77"-a c c e p t a n c e a r e n o t o u t w e i g h e d by t h e e f f e c t s o f o t h e r more e l e c t r o n e g a t i v e g r o u p s . F o r e x a m p l e , w o r k w i t h t h e m- a n d 7 1 j£-fluorophenyl d e r i v a t i v e s o f PhPMe^ a n d P h P P h 2 show t h a t t h e - P M e 2 a n d - P P h 2 g r o u p s a r e weak b u t n e t 7 7 -d o n o r s t o t h e f l u o r o p h e n y l g r o u p s . H o w e v e r , f r o m s i m i l a r d a t a o b t a i n e d w i t h P h P F 2 , i t i s a p p a r e n t t h a t t h e a c c u m u -l a t i o n o f p o s i t i v e c h a r g e o n p h o s p h o r u s , r e s u l t i n g f r o m C T - e l e c t r o n w i t h d r a w a l by f l u o r i n e , w i l l i n c r e a s e Ph-+P an d F—»P p77-d77" a c c e p t o r a c t i o n a n d g e n e r a l l y t e n d t o 7 1 d e c r e a s e P — ^ P h p77" -p77 d o n o r a c t i o n . C o n s i d e r i n g t h a t t h e e l e c t r o n e g a t i v i t i e s o f c a r b o n and s u l p h u r , b a s e d o n t h e A l l r e d - R o c h o w f o r m u l a , a r e 2.50 a n d 2.44 r e s p e c t i v e l y , i t i s n o t u n r e a s o n a b l e t o s u p p o s e , on t h e b a s i s o f i n d u c -t i v e e f f e c t s a l o n e , t h a t t h e a c c u m u l a t i o n o f p o s i t i v e c h a r g e a t p h o s p h o r u s i n P^S^ i s n o t g r e a t l y d i f f e r e n t f r o m t h a t i n P h P P h 2 o r P h P M e 2 . S i n c e i t h a s b e e n shown t h a t t h e - P P h 2 a n d - P M e 2 m o i e t i e s a r e weak 77"-donors t o t h e a t t a c h e d f l u o r o p h e n y l r i n g s , i t seems r e a s o n a b l e t o s u p p o s e t h a t t h e p h o s p h o r u s a t o m s i n P^S^ a r e c a p a b l e o f s i m i l a r a c t i o n w i t h r e s p e c t t o s u l p h u r . A t t h e same t i m e , t h e 7 2 - 7 4 a c c e p t o r p r o p e r t i e s o f s u l p h u r a r e w e l l - k n o w n ; i n d e e d t h e s e c o n d p a r t o f t h i s t h e s i s w i l l r e v e a l t h e i m p o r t a n t a c c e p t o r p r o p e r t i e s o f s u l p h u r i n c y c l i c p h o s p h o r u s -s u l p h u r s y s t e m s . - 7 0 -I n f u r t h e r a t t e m p t s t o o b t a i n some i n d i c a t i o n o f t h e f a c t o r s i m p o r t a n t i n t h e b o n d i n g o f t h i s compound, s i m p l e H u c k e l m o l e c u l a r o r b i t a l (HMO) c a l c u l a t i o n s h a v e b e e n c a r r i e d o u t o n P^S^ w i t h t h e f o l l o w i n g a s s u m p t i o n s . The m o l e c u l a r g e o m e t r y was c o n s i d e r e d t o be t h a t o f t h e d e -33 t e r m i n e d c r y s t a l s t r u c t u r e . I n t e r a c t i o n s w e r e i n c l u d e d b e t w e e n 3 p - o r b i t a l s o n l y , o v e r l a p b e i n g n e g l e c t e d e x c e p t f o r t h e p u r p o s e o f e s t i m a t i n g r e s o n a n c e i n t e g r a l s . The c o u l o m b i n t e g r a l o f p h o s p h o r u s was t a k e n a s 0, a n d t h a t o f s u l p h u r a s - 0 . 4 e V . R e s o n a n c e i n t e g r a l s w e r e e s t i m a t e d b y m u l t i p l y i n g t h e n u m e r i c a l o v e r l a p b y - 2 . 0 e V . , t h e o v e r l a p s f o r t h e two s t a n d a r d o r i e n t a t i o n s ( <J- a n d 77-) 75 b e i n g t a k e n f r o m t h e t a b l e s o f M u l l i k e n f o r t h e a p p r o -p r i a t e i n t e r n u c l e a r d i s t a n c e s , t h e b o n d a s y m m e t r y p a r a -m e t e r t b e i n g t a k e n a s 0. The o r i e n t a t i o n o f t h e p -o r b i t a l s i s shown i n F i g . 2. B e c a u s e 3pO" - 3pO" o v e r l a p i s s t i l l s u b s t a n t i a l a t l a r g e i n t e r n u c l e a r d i s t a n c e s , c a l c u l a t i o n s w e r e c a r r i e d o u t f o r ( i ) i n t e r a c t i o n s b e t w e e n d i r e c t l y b o n d e d a t o m s a n d ( i i ) i n t e r a c t i o n s b e t w e e n a l l a t o m s , s o i n c l u d i n g P-P i n t e r a c t i o n s a c r o s s a s u l p h u r a t o m , S - S ' i n t e r a c t i o n s a n d r e m o t e S-P i n t e r a c t i o n s . T y p i c a l e n e r g y d i a g r a m s a r e shown i n F i g . 3 . The f o l l o w i n g g e n e r a l r e s u l t s w e r e o b t a i n e d : A. T o t a l b i n d i n g e n e r g i e s ( e V . ) D i r e c t l y b o n d e d a t o m s o n l y , 0 " - i n t e r a c t i o n s o n l y : - 1 7 . 3 D i r e c t l y b o n d e d a t o m s o n l y , CT- + 7 7 - i n t e r a c t i o n s : -18.4 A l l b o n d s , ( J - i n t e r a c t i o n s o n l y : -17.6 A l l b o n d s , ( J - + 7 7 - i n t e r a c t i o n s : - 1 8 . 9 - 7 1 -Or ientat ion of p-orbitals as used in the calculat ion 1.5 1.0 0.5 c*p=0| -0.5 A 2 ~ T A 2 f -1.0 directly bonded directly bonded atoms only atoms only all bonds 0", 173eV 0"+TT\ 18.4 eV 0"+Tr,l8.9eV FIG. 3- Energy levels of F^ Sg as derived by HMO calculations - 7 3 -I n c l u s i o n o f t h e more r e m o t e b o n d s h a s a s i g n i f i c a n t s t a b i l i z i n g e f f e c t o n t h e m o l e c u l e , b u t t h e i n c l u s i o n o r e x c l u s i o n o f 7 7 - i n t e r a c t i o n s i s more i m p o r t a n t . B. The t o t a l c h a r g e d e n s i t y a t i n d i v i d u a l a t o m s d e c r e a s e s i n t h e o r d e r S > P, _>P„„^ . F o r two c a s e s , t h e v a l u e s b a s e a p e x * a r e a s f o l l o w s P S P. a p e x b a s e ( J - i n t e r a c t i o n s o f d i r e c t b o n d s : 2.15 4.54 2.75 A l l b o n d s , C T - + 7 7 - i n t e r a c t i o n s : 2.11 4.55 2.75 C. F o r a l l t h e c a s e s c o n s i d e r e d , t h e e n e r g e t i c a l l y l o w -e s t a c c e p t o r o r b i t a l s a r e o f s p e c i e s A^, A^, a n d E, u s u a l l y i n c r e a s i n g i n t h a t o r d e r . The e n e r g y g a p b e t w e e n t h e h i g h e s t o c c u p i e d ( a l w a y s s p e c i e s E) a n d l o w e s t u n o c c u p i e d o r b i t a l s i s d e p e n d e n t m a i n l y o n t h e e x t e n t o f t h e 7 7 -b o n d i n g ; t h e e n e r g y gap i s ( e V . ) d i r e c t l y b o n d e d a t o m s , C J - i n t e r a c t i o n s o n l y : 0.73 d i r e c t l y b o n d e d a t o m s , C J - + 7 7 - i n t e r a c t i o n s : 0.28 A l l b o n d s , C J - i n t e r a c t i o n s o n l y : 0 . 5 1 * A l l b o n d s , C J - + 7 7 - i n t e r a c t i o n s : 0.39 • f i r s t a c c e p t o r l e v e l E; A 1 , k0 0.02, 0.03 eV h i g h e r D. A l l t h r e e l e v e l s a r e c l o s e e n o u g h t o t h e o c c u p i e d l e v e l s t o a c c e p t e l e c t r o n s s i g n i f i c a n t l y , b u t t h e y do s o d i f f e r e n t l y . ( i ) The A 2 l e v e l i s composed o f ' t a n g e n t i a l ' p - o r b i t a l s a t s u l p h u r , a n d p a i r s i n t h e b a s e p l a n e a n t i s y m m e t r i c t o t h e s y m m e t r y p l a n e s o f C^ r. The a t o m i c o r b i t a l s h a v e -74-o n l y a 7 7 - i n t e r a c t i o n , a n d no s , p o r d o r b i t a l o f a n a p i c a l l y - a t t a c h e d a t o m h a s t h e r i g h t s y m m e t r y t o i n t e r a c t w i t h i t . I t i s e s s e n t i a l l y a n o n - b o n d i n g c o m b i n a t i o n w h i c h c a n a c c e p t e l e c t r o n s , b u t c a n h a r d l y be c o n s i d e r e d a ' l o n e - p a i r 1 . ( i i ) The A 1 c o m b i n a t i o n c o n t a i n s c o n t r i b u t i o n f r o m a l l t h r e e a t o m s . E n e r g i e s a n d c h a r g e d e n s i t i e s a r e a s f o l l o w s : P S P v a b ( 7 - i n t e r a c t i o n s o f d i r e c t l y b o n d e d a t o m s ( 0 . 3 8 eV.) 1.06 0.22 0.09 ( J - + 7 7 - i n t e r a c t i o n s o f d i r e c t l y b o n d e d a t o m s ( 0 . 3 4 eV.) 1.06 0.13 0.19 A l l b o n d s , CT- + 7 7 - i n t e r -a c t i o n s ( 0 . 1 6 eV.) 0.87 0.21 0.17 I n c r e a s i n g t h e number o f i n t e r a c t i o n s l o w e r s t h e e n e r g y , b u t t h e d e n s i t y r e m a i n s s t r o n g l y l o c a l i z e d o n P , T h i s c o m b i n a t i o n i s t h e r e f o r e a s t r o n g ( J - a c c e p t o r o r b i t a l , o f t h e same s y m m e t r y a s a d 2 o r b i t a l o f a n a p i c a l l y a t t a c h e d m e t a l a t o m . ( i i i ) The E c o m b i n a t i o n a g a i n c o n t a i n s c o n t r i b u t i o n s f o r a l l a t o m s , e n e r g i e s a nd c h a r g e d e n s i t i e s b e i n g g i v e n b e l o w , P S P^ a b < T - i n t e r a c t i o n s o f d i r e c t l y b o n d e d a t o m s ( 0 . 4 5 eV.) 0.50 0.42 0.38 CT- + 7 7 - i n t e r a c t i o n s o f d i r e c t l y b o n d e d a t o m s ( 0 . 3 5 eV.) 0.13 0.54 0.75 A l l b o n d s , CT- + T T - i n t e r -a c t i o n s ( 0 . 1 9 eV.) 0.24 0.46 0.79 A g a i n , i n c l u s i o n o f more i n t e r a c t i o n s l o w e r s t h e o r b i t a l - 7 5 -e n e r g y , b u t h a s a much b i g g e r e f f e c t o n t h e e l e c t r o n d i s t -r i b u t i o n o f t h e E o r b i t a l t h a n i t h a s on t h e A 1 o r b i t a l ; e l e c t r o n d e n s i t y i s d i s t r i b u t e d f r o m P o n t o S a n d P^. a b T h i s o r b i t a l s h o u l d be a b l e t o a c c e p t c h a r g e e f f e c t i v e l y f r o m b o t h t h e d „ . d 2 „ 2 a n d t h e d „ . d„„ d e g e n e r a t e x y * x — y x z y z p a i r s . E. F i n a l l y i t s h o u l d be e m p h a s i z e d t h a t t h e s e a r e m o d e l c a l c u l a t i o n s o n l y , d e s i g n e d t o f i n d o u t t h e l i k e l y m o s t i m p o r t a n t f a c t o r s i n v o l v e d i n b o n d i n g a n d d o n o r - a c c e p t o r i n t e r a c t i o n s . A p a r t f r o m some o b v i o u s l i m i t a t i o n s a r i s -i n g f r o m t h e u s e o f t h e H i i c k e l m o d e l a nd t h e o m i s s i o n o f s - o r b i t a l s , t h e r e i s a n o t h e r i n h e r e n t i n t h e s e c a l c u l a t i o n s , i n t h a t 7 7 - i n t e r a c t i o n s a r e o v e r e s t i m a t e d f o r two r e a s o n s . ( i ) The o v e r l a p c a l c u l a t i o n s u s e n o d e l e s s 3 p - o r b l t a l s ; o m i s s i o n o f t h e s p h e r i c a l n o d e g i v e s t o o h i g h a 7 7 - o v e r l a p . ( i i ) The 7 7 - 6 v e r l a p t a k e s p l a c e i n a w e a k e r n u c l e a r f i e l d t h a n t h e C J - o v e r l a p , s o a s m a l l e r , b u t unk n o w n , p r o p o r -t i o n a l i t y c o n s t a n t t h a n - 2.0 eV. s h o u l d be u s e d . I t seems u n l i k e l y t h a t u s e o f a b e t t e r v a l u e w o u l d i n v a l i d a t e t h e a b o v e q u a l i t a t i v e c o n c l u s i o n s . T h i s m o d e l c a l c u l a t i o n h a s r e v e a l e d t h e i m p o r t a n c e o f a d d i t i o n a l t h r o u g h - c a g e C J - and 7 7 - i n t e r a c t i o n s a n d t h e o b s e r v e d c h e m i s t r y o f "P^Sj i s c o n s i s t e n t w i t h t h i s i d e a . T r e a t m e n t o f P^S^ w i t h a w i d e v a r i e t y o f o x i d a n t s i n v a r i a b l y l e a d s t o c a g e b r e a k d o w n , i m p l y i n g t h a t e v e n - 7 6 -t h o u g h 7 7 - b o n d i n g i s f o r m a l l y o f s e c o n d a r y i m p o r t a n c e , a n y r e m o v a l o f e l e c t r o n s f r o m P^S^ i s s u f f i c i e n t t o i n d u c e c a g e f r a c t u r e . S i m i l a r l y , e x p e r i m e n t s w i t h a - P ^ S ^ I ^ h a v e shown t h a t f o r m a t i o n o f t h e c a t i o n P ^ S ^ 2 * i s n o t f a v o u r e d . The v a l u e s o f c h a r g e d e n s i t y a t t h e a p i c a l a n d b a s a l p h o s p h o r u s a t o m s h a v e c o n f i r m e d t h a t t h e a p i c a l p h o s p h o r u s a t o m ( P a ) i s e x p e c t e d t o be l e s s b a s i c t h a n t h e b a s a l p h o s p h o r u s a t o m s . D e s p i t e t h e l o w e r c h a r g e d e n s i t y a t P a , P^S-j i s known t o c o o r d i n a t e t h r o u g h t h i s p h o s p h o r u s a t o m . The m o s t l i k e l y e x p l a n a t i o n f o r t h i s b e h a v i o u r i s t h a t , s i n c e i t h a s b e e n e s t a b l i s h e d t h a t P^S^ w i l l o n l y c o m p l e x w i t h t h o s e m e t a l s c a p a b l e o f s y n e r g i s t i c i n t e r a c t i o n s , 7 7 - d e n s i t y r e c e i v e d b y P a c a n , i n p a r t , be s h a r e d e q u a l l y b y t h e t h r e e s u l p h u r a t o m s t o w h i c h i t i s d i r e c t l y b o n d e d . As y e t no c o m p l e x e s h a v e b e e n i s o l a t e d i n w h i c h i t i s known t h a t P^S^ c o o r d i n a t e s t h r o u g h a b a s a l p h o s p h o r u s a t o m ( o r t o t h e e n t i r e P^ r i n g ) , b u t s u c h c o o r d i n a t i o n i s e n t i r e l y p o s s i b l e , p a r t i c u l a r l y i n v i e w o f t h e f a c t t h a t 76 P^ i s k n o w n t o f o r m c o o r d i n a t i o n c o m p l e x e s . S i n c e t h e l o w e s t u n 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 o f P^S^ a r e n o n - b o n d i n g i n t h e c a s e o f t h e A 2 l e v e l , o r a n t i -b o n d i n g i n t h e c a s e o f t h e A^ a n d E l e v e l s , a c c e p t o r a c t i o n b y P^S^ i s n o t e x p e c t e d t o s t r e n g t h e n t h e c a g e s t r u c t u r e . The r e c e n t l y p u b l i s h e d c r y s t a l s t r u c t u r e o f P ^ S ^ M o t C O ) ^ - 7 7 -i s t h e o n l y t r a n s i t i o n m e t a l c o m p l e x o f P^S^ e x a m i n e d i n 57 t h i s way t o d a t e . A l t h o u g h t h e a u t h o r s ^ a r g u e t h a t a l l t h e P-S b o n d l e n g t h s h a v e i n c r e a s e d a n d a r e t h e r e f o r e w e a k e n e d w i t h r e s p e c t t o u n c o m p l e x e d P^S^, t h e s t r u c t u r e d e t e r m i n a t i o n i s u n f o r t u n a t e l y n o t s u f f i c i e n t l y a c c u r a t e t o c l a i m t h a t s i g n i f i c a n t c h a n g e s h a v e o c c u r r e d . M o r e o v e r t h e r e p o r t e d i n f r a r e d b a n d s b e l o n g i n g t o P^S^ i n t h i s c o m p l e x ( 4 7 5 , 435 and 415 cm ) d i f f e r v e r y s l i g h t l y f r o m t h o s e o f u n c o m p l e x e d P^S^ ( 4 7 8 , 434 and 419 cm" r e s p e c t i v e l y ) . S u c h m i n o r c h a n g e s seem i n c o n s i s t e n t w i t h -s i g n i f i c a n t b o n d w e a k e n i n g ; a l s o , i t h a s b e e n e s t a b l i s h e d t h a t t h e i n f r a r e d b a n d s a t 434 and 419 cm""*" a r e due t o P-S s t r e t c h i n g s o t h a t t h e s e two b a n d s w o u l d be e x p e c t e d t o c h a n g e t h e m o s t i f t h e s t r e n g t h o f t h e P-S b o n d i s a l t e r e d . The i n f r a r e d a n d Raman s p e c t r a o f P t ( P B u ^ ) ( P ^ S ^ ) 2 c o n f i r m t h a t t h e v i b r a t i o n a l f r e q u e n c i e s o f P^S^ c h a n g e l i t t l e u p o n c o m p l e x f o r m a t i o n , i n t h a t t h e l a r g e s t s h i f t o f f r e q u e n c y i s o n l y 4 cm . The f a c t t h a t t h e v i b r a t i o n a l f r e q u e n c i e s o f P^S^ c h a n g e s o l i t t l e u p o n c o o r d i n a t i o n s u g g e s t s t h a t t h e n o n - b o n d i n g A 2 l e v e l may be t h e p r i m a r y r e c i p i e n t o f 77"-charge f r o m t h e m e t a l . The c h e m i s t r y o f a -P^S-^Ig i s i n t r i g u i n g , a n d a s p o i n t e d o u t e a r l i e r , i s u s e f u l i n g i v i n g a n i d e a o f t h e b a s e s t r e n g t h o f P^S^. The f a i l u r e t o r e p l a c e i o d i n e b y o t h e r s u b s t i t u e n t s d e f i e s a r e a d y e x p l a n a t i o n . I t h a s b e e n shown t h a t t h e 7 7 - s y s t e m i n P A S , i s o f s m a l l b u t c r u c i a l - 7 8 -p r o p o r t i o n s . I o d i n e h a s a n e l e c t r o n e g a t i v i t y i n t e r m e d i a t e b e t w e e n t h o s e o f p h o s p h o r u s a n d s u l p h u r a n d i s a l s o c a p a b l e o f p a r t i c i p a t i o n i n 7 T - b o n d i n g . I t i s p o s s i b l e t h e r e -f o r e t h a t i o d i n e may be i d e a l l y s u i t e d t o t h e b o n d i n g scheme i n P^S^ w h e r e a s t h e r e l a t i v e l y ' h a r d e r ' g r o u p s s u c h a s -CN a n d -SCN a r e n o t . The i m p o r t a n c e o f i n d i r e c t b o n d i n g i n t e r a c t i o n s i n t h e P ^ S ^ ^ s y s t e m may w e l l a c c o u n t f o r t h e g r e a t e r s t a b i l i t y o f d - P ^ S ^ . The ' a n g l e s o f f o l d ' i n d - P 4 S 5 I 2 ( s h o w n b e l o w 1 4 9 ) a r e 91° a n d t h e c l o s e s t i n t r a m o l e c u l a r P-S d i s t a n c e s a r e 3.1A°, 0.6A° l e s s t h a n t h e sum o f t h e v a n d e r W a a l s r a d i i . B y c o n t r a s t t h e a n g l e s o f f o l d i n ^ - P ^ S j I g a r e 95° a n d 106° a n d t h e i n t r a m o l e c u l a r P-P a n d S-S d i s t a n c e s a r e i n c r e a s e d t o 3.27 a n d 3 . 3 4 A 0 r e s p e c t i v e l y 3 2 . -79-The problem of i n t r a c t a b i l i t y should be mentioned as 29 77 78 other workers ^* ''* have experienced s i m i l a r d i f f i c u l t i e s . The p o s s i b i l i t y of m u l t i p l e c o o r d i n a t i o n s i t e s on P^S^ could l e a d t o f o r m a t i o n o f polymeric complexes by way of 76 b r i d g i n g l i g a n d s . The f a c t t h a t P^ has been found' to form c o o r d i n a t i o n complexes r e i n f o r c e s the i d e a t h a t the apical.phosphorus i n P^S^ may not be the o n l y s i t e capable of c o o r d i n a t i o n . I t i s not yet known how P^ coordinates 76 but Ginsberg and L i n d s e l l favour c o o r d i n a t i o n through the centre o f a P^ r i n g i n view of the bonding scheme t h a t 79 101 has been proposed ^' f o r P^. A s i m i l a r type of bond through the P^ r i n g i n P^S^ i s t h e r e f o r e not unreasonable. There i s l i t t l e chance of p o l y m e r i z a t i o n i n I r C l 2 ( H ) ( C O ) ( P h 5 P ) ( P 4 S 3 ) , but i t i s worth n o t i n g t h a t the analogous t r i p h e n y l p h o s p h i n e c o mplex 4 9, I r C l 2 ( H ) ( G O ) ( P h ^ P ) 2 , i s r e p o r t e d l y too i n s o l u b l e to a l l o w e i t h e r m o l e c u l a r weight or n.m.r. measurements. Thus, even though complexes may be monomeric, they may a l s o be i n h e r e n t l y i n s o l u b l e . In c o n c l u s i o n , the b e l i e f t h a t sulphur atoms i n P^S^ a c t as acceptors leads one to s p e c u l a t e t h a t donor prop-e r t i e s w i l l decrease i n the h i g h e r phosphorus s u l p h i d e s . On t h i s b a s i s , i t i s not s u r p r i s i n g t h a t the attempts of Nixon et a l 2 9 to prepare a complex of P^S^ by h e a t i n g c i s - C P ^ S ^ ) 2 M o ( C O ) ^ w i t h sulphur were u n s u c c e s s f u l and l e d o n l y to i s o l a t i o n of f r e e ^ S ^ . Acceptor p r o p e r t i e s of the h i g h e r s u l p h i d e s would be expected to be g r e a t e r than - 8 0 -t h o s e o f P^S^ a n d i t h a s b e e n f o u n d , f o r e x a m p l e , t h a t t h e h i g h e r s u l p h i d e s a r e much l e s s s t a b l e t o w a r d h y d r o -102 l y s i s t h a n i s P ^ S ^ . A r e c e n t p u b l i c a t i o n o f t h e r e a c -t i o n s o f P ^ S ^ Q w i t h n u c l e o p h i l e s s u c h a s N^"" a n d CN~ c o n -f i r m s t h a t P^S-J^Q h a s s t r o n g 7 7 - a c c e p t o r p r o p e r t i e s . I n a d d i t i o n , t h e s e w o r k e r s w e r e a b l e t o p r e p a r e t h e a n i o n P^SgN" i n w h i c h a b r i d g i n g s u l p h u r i s r e p l a c e d b y n i t r o -g e n . T h i s a n i o n was i s o l a t e d a s i t s t e t r a - n - p r o p y l a m -monium s a l t a n d c o u l d n o t m e t h y l a t e d w i t h d i m e t h y l s u l -p h a t e , i m p l y i n g t h a t t h e r e i s c o n s i d e r a b l e e l e c t r o n i c d e r e a l i z a t i o n . The f a i l u r e o f P^S^ t o be q u a t e r n i z e d b y M e S 0 5 P o r E t ^ O B F ^ i s more i n t e r e s t i n g i n l i g h t o f t h e s e e x p e r i m e n t s . - 8 1 -PART 2 ORGANOPHOSPHORUS-SULPHUR COMPOUNDS  I EXPERIMENTAL A. INTRODUCTION: The p r o b l e m o f i n t r a c t a b i l i t y w h i c h c h a r a c t e r i z e d s o much o f t h e w o r k i n v o l v i n g P^S^ l e d t o e x p e r i m e n t s w i t h c y c l i c o r g a n o p h o s p h o r u s - s u l p h u r compounds i n s t e a d . The p r e s e n c e o f o r g a n i c g r o u p s o n p h o s p h o r u s w o u l d be e x p e c t e d t o make t h e s e compounds more s o l u b l e a n d t h u s s i m p l i f y p u r i f i c a t i o n a n d c h a r a c t e r i z a t i o n ; t h e p r e s e n c e o f s u c h g r o u p s e l i m i n a t e s , o f c o u r s e , t h e p o s s i b i l i t y o f c a g e f o r m a t i o n . A c h a r a c t e r i s t i c f e a t u r e o f t h e c h e m i s t r y o f t h e c a g e p h o s p h o r u s s u l p h i d e s i s t h e i r c o n s i d e r a b l e b o n d m o b i l i t y , q u i t e d r a s t i c c h a n g e s i n s t r u c t u r e o c c u r r i n g u n d e r v e r y m i l d r e a c t i o n c o n d i t i o n s . One o f t h e a i m s o f t h i s w o r k h a s b e e n t o i n v e s t i g a t e t h e p o s s i b i l i t y o f s i m i l a r p r o p e r t i e s i n c y c l i c o r g a n o p h o s p h o r u s - s u l p h u r c ompounds. A s e c o n d i m p o r t a n t a i m h a s b e e n t o e x a m i n e t h e e l e c t r o n i c i n t e r a c t i o n s w i t h i n t h e s e compounds b y p r e p a r i n g t h e i r m e t a - a n d p a r a - f l u o r o p h e n y l d e r i v a t i v e s . 19 An a n a l y s i s o f t h e ^P n.m.r. c h e m i c a l s h i f t s a c c o r d i n g 80 t o t h e m e t h o d s o f T a f t e t a l w o u l d be e x p e c t e d t o be q u i t e i n f o r m a t i v e . I n o r d e r t o p r o p e r l y i n t e r p r e t t h e s e n.m.r. d a t a , a n d i n d e e d t h e r e s t o f t h i s w o r k , i t i s i m p o r t a n t t o know t h e s t r u c t u r e s o f t h e compounds - 8 2 -b e i n g e x a m i n e d . A l t h o u g h many o f t h e compounds p r e p a r e d i n t h i s s e c t i o n a r e n o t new, t h e s t r u c t u r e s o f s e v e r a l w e r e u n c e r t a i n o r d i s p u t e d a t t h e t i m e t h i s w o r k was u n d e r t a k e n . T h e s e s t r u c t u r e s h a v e t h e r e f o r e b e e n e l u c i d a t e d u s i n g c r y s t a l l o g r a p h i c a n d s p e c t r o s c o p i c m e t h o d s . I n a d d i t i o n , t h e s p e c t r o s c o p i c p r o p e r t i e s o f t h o s e compounds o f known s t r u c t u r e w e r e e x a m i n e d i n g r e a t e r d e t a i l t h a n h a s b e e n r e p o r t e d p r e v i o u s l y . The r e a c t i o n o f p h e n y l d i c h l o r o p h o s p h i n e w i t h 8 1 h y d r o g e n s u l p h i d e was r e p o r t e d b y M i c h a e l i s t o g i v e P h 2 P 2 S 2 . No f u r t h e r r e p o r t s h a v e b e e n made r e g a r d i n g a compound o f t h i s c o m p o s i t i o n a n d s i n c e t h e p r o p o s e d s t r u c t u r e , P h 2 P ( S ) - P = S , d i d n o t seem v e r y l i k e l y i n v i e w o f p r e s e n t k n o w l e d g e , t h i s r e a c t i o n was r e i n v e s t i g a t e d . P h e n y l d i c h l o r o p h o s p h i n e a n d h y d r o g e n s u l p h i d e w e r e h e a t e d t o g e t h e r i n a n a u t o c l a v e a t 95°C; t h e s o l i d m a t e r i a l i s o l a t e d f r o m t h e o i l y r e a c t i o n m i x t u r e was s hown t o be c y c l o t r i p h e n y l t r i p h o s p h i n e t r i s u l p h i d e , P h ^ P ^ S ^ , b y a n a l y t i c a l r e s u l t s a n d b y c o m p a r i s o n w i t h t h e 8 2—R A m i n i m a l d a t a r e p o r t e d i n t h e l i t e r a t u r e , S i n c e t h e 8 2 — 8 5 s t r u c t u r e o f t h i s compound was b y no means c e r t a i n , P h ^ P ^ S ^ was i n v e s t i g a t e d more f u l l y . The y i e l d s o f P h ^ P ^ S ^ f r o m t h e M i c h a e l i s m e t h o d w e r e l o w a n d l a r g e a m o u n t s o f o i l y p r o d u c t s w e r e f o r m e d ; t h e r e f o r e , new s y n t h e t i c r o u t e s t o P h ^ P ^ S ^ w e r e e x a m i n e d . Z i n c s u l p h i d e a n d p h e n y l d i c h l o r o p h o s p h i n e d i d n o t r e a c t ; h o w e v e r , -83-anhydrous sodium s u l p h i d e and phenyldichlorophosphine were found to produce Ph^P^S^ i n g e n e r a l l y b e t t e r y i e l d s than the M i c h a e l i s method. As the y i e l d s were not con-op s i s t e n t l y h i g h , the method of Maier was used f o r r o u t i n e p r e p a r a t i o n of Ph^P^S^. S e v e r a l attempts were made to prepare a l k y l -s u b s t i t u t e d analogues of Ph^P^S^, but none were success-f u l . Thus, although e t h y l d i c h l o r o p h o s p h i n e appeared to r e a c t w i t h both K 2S and Na 2S, no product would be i s o l -ated from the r e a c t i o n mixture. Methylphosphine was found to r e a c t w i t h sulphur to gi v e methylthionophosphine Rf i 8*7 s u l p h i d e dimer, Me 2P 2S 4; ' s u r p r i s i n g l y , the same product was i s o l a t e d when methylphosphine was t r e a t e d w i t h an equimolar amount of sulphur d i c h l o r i d e . In an attempt to prepare Ph^P^S^, anhydrous potassium s u l p h i d e was fused w i t h phenyldichorophosphine. E x t r a c -t i o n of the fused mass y i e l d e d a s m a l l amount of y e l l o w c r y s t a l s which were i d e n t i f i e d as t e t r a p h e n y l c y c l o -tetraphosphine monosulphide, Ph^P^S, from a n a l y t i c a l data 82 and from a l i t e r a t u r e r e p o r t ; the r e a c t i o n of phenyl-phosphonothioic d i c h l o r i d e , P h P ( S ) C l 2 , w i t h phenyl-phosphine was a l s o found to produce Ph^P^S. The s t r u c t u r e of Ph^P^S proved to be r a t h e r d i f f i c u l t to e l u c i d a t e as 31 the v i b r a t i o n a l s p e c t r a were i n c o n c l u s i v e and a ' P n.m.r. spectrum was of poor q u a l i t y . T h i s compound was - 8 4 -t h e r e f o r e s t r u c t u r a l l y c h a r a c t e r i z e d h y a s i n g l e c r y s t a l X - r a y s t u d y . 8 ? The o r i g i n a l w o r k o f M a i e r h a s shown t h a t i t i s p o s s i b l e t o p r e p a r e t h e h i g h e r s u l p h u r - c o n t a i n i n g c y c l i c compounds P h ^ P ^ S ^ a n d P l ^ P ^ S ^ h y r e a c t i o n o f Ph^P^S w i t h t h e p r o p e r s t o i c h i o m e t r i c a m o u n t s o f s u l p h u r . To e l a b o r a t e t h i s w o r k , a n d t o d e t e r m i n e t h e p o s s i b l e r e v e r s i b i l i t y o f s u l p h u r a d d i t i o n , t h e f o l l o w i n g s e t o f - 21 e x p e r i m e n t s was u n d e r t a k e n . I t i s known t h a t a n e x c e s s o f i o d i n e i s c a p a b l e o f o x i d i z i n g P^S^ t o P^S^; s i m i l a r l y , when P h ^ P ^ S ^ i s t r e a t e d w i t h a n e q u i m o l a r amount o f i o d i n e a t room t e m p e r a t u r e , i t i s i m m e d i a t e l y o x i d i z e d t o p h e n y l t h i o n o p h o s p h i n e s u l p h i d e d i m e r , P h 0 P 0 S „ . On t h e o t h e r h a n d , t h e r e a c t i o n o f Ph.P.S 2 2 4 4 4 w i t h i o d i n e a t room t e m p e r a t u r e r e s u l t s i n r i n g c l e a v a g e a n d t h e p r o d u c t i o n o f 1 , 2 - d i p h e n y l - 1 , 2 - d i -88 i o d o d i p h o s p h i n e , P h 2 P 2 I 2 . T r i p h e n y l p h o s p h i n e h a s b e e n shown t o be c a p a b l e o f r e m o v i n g s u l p h u r f r o m P^S^; s i m i l a r l y , t h e s t r o n g t h i o p h i l e , t r i b u t y l p h o s p h i n e , i s c a p a b l e o f r e m o v i n g s u l p h u r f r o m P h ^ P ^ S ^ t o g i v e P h ^ P ^ S . The r e m a i n i n g s u l p h u r i s f i r m l y h e l d h o w e v e r , a n d c a n n o t be r e m o v e d b y t r i b u t y l p h o s p h i n e i n b o i l i n g x y l e n e . The r e a c t i o n o f t r i b u t y l p h o s p h i n e , Bu^P, w i t h P h 2 P 2 S 4 89 h a s b e e n e x a m i n e d p r e v i o u s l y , a n d Bu^P h a s b e e n f o u n d t o c l e a v e t h e d i m e r a n d s u b s e q u e n t l y a d d t o t h e monomer g i v i n g t h e s p e c i e s P h - P - P B u ^ . The d e s u l p h u r i z a t i o n o f S" - 8 5 -P h 2 P 2 S 4 w a s "therefore a t t e m p t e d u s i n g e l e m e n t a l m e r c u r y . A t room t e m p e r a t u r e P h 2 P 2 S 4 a n d m e r c u r y s l o w l y r e a c t t o p r o d u c e a w h i t e , m e r c u r y - c o n t a i n i n g compound; t h e r e a c t i o n o f P h ^ P ^ S ^ w i t h m e r c u r y u n d e r s i m i l a r c o n -d i t i o n s p r o d u c e s t h e same compound. H o w e v e r , i f t h e r e a c t i o n i s a l l o w e d t o p r o c e e d f o r a l o n g e r p e r i o d o f t i m e , t h e amount o f m e r c u r y - c o n t a i n i n g i n t e r m e d i a t e d e -c r e a s e s a n d Ph^P^S c a n be i s o l a t e d . T h e s e e x p e r i m e n t s , op t o g e t h e r w i t h t h o s e i n t h e l i t e r a t u r e , i l l u s t r a t e t h a t i t i s i n d e e d p o s s i b l e , b y a d d i t i o n o r r e m o v a l o f s u l p h u r , t o i n t e r c o n v e r t b e t w e e n P h ^ P ^ S , P h ^ P ^ S ^ a n d P h 2 P 2 S 4 w i t h r e m a r k a b l e e a s e . S e v e r a l d i v e r s e e x p e r i m e n t s w e r e a t t e m p t e d w i t h t h e compounds whose c h e m i s t r y i s o u t l i n e d i n t h i s i n t r o -d u c t i o n . F o r e x a m p l e , b o t h P h ^ P ^ S ^ and Ph^P^S w e r e t r e a t e d w i t h t u n g s t e n h e x a c a r b o n y l i n b o i l i n g t e t r a -h y d r o f u r a n b u t n e i t h e r was f o u n d t o r e a c t . F u s i o n o f P h ^ P ^ S j w i t h m o l y b d e n u m h e x a c a r b o n y l r e s u l t e d i n d e -c o m p o s i t i o n a nd a p p a r e n t f o r m a t i o n o f M o S 2 . C h l o r o t r i s -( t r i p h e n y l p h o s p h i n e ) r h o d i u m ( I ) was f o u n d t o r e a c t q u i c k l y w i t h P h ^ P ^ S ^ b u t t r i p h e n y l p h o s p h i n e s u l p h i d e was i s o l a t e d a s a b y p r o d u c t i n d i c a t i n g t h a t l i g a n d r e -a r r a n g e m e n t o r d e c o m p o s i t i o n h a d o c c u r r e d a nd t h e r e f o r e t h e r e a c t i o n m i x t u r e was d i s c a r d e d . I n a n a t t e m p t t o p r e p a r e a n o v e l t y p e o f p h o s p h o r u s - s u l p h u r compound, - 8 6 -P h 2 P 2 I 2 w a s t r e a t e d w i t h e t h a n e t h i o l b u t no r e a c t i o n was o b s e r v e d . S u r p r i s i n g l y , a n a t t e m p t t o p r e p a r e 1,2-d i p h e n y l - 1 , 2 - d i i o d o d i p h o s p h i n e d i s u l p h i d e b y t h e r e a c t i o n o f P h 2 P 2 I 2 w i t h e l e m e n t a l s u l p h u r was u n s u c c e s s f u l a n d b o t h s t a r t i n g m a t e r i a l s w e r e r e c o v e r e d u n r e a c t e d . To a s s e s s e l e c t r o n i c i n t e r a c t i o n w i t h i n t h e p h o s p h o r u s - s u l p h u r r i n g s , a n d t o t a k e a d v a n t a g e o f t h e f a c t t h a t t h e p h e n y l g r o u p i s a p p a r e n t l y a f a v o u r e d s u b -1Q s t i t u e n t , t h e ^F c h e m i c a l s h i f t s o f t h e m e t a - a n d p a r a -f l u o r o p h e n y l d e r i v a t i v e s o f P h ^ P ^ S , P h j P ^ S ^ a n d P h g P ^ w e r e o b t a i n e d a n d a n a l y z e d u s i n g t h e e s t a b l i s h e d m e t h o d s o f T a f t e t a l . 8 0 F o r c o m p a r i s o n p u r p o s e s , t h e 1 9 F c h e m i c a l s h i f t s o f t h e r e l a t e d compounds ( F C g H 4 P ) n a n d ( F C g H ^ P I ) , , w e r e a l s o o b t a i n e d . F i n a l l y , t h e mass s p e c t r a o f many o f t h e s e compounds h a v e b e e n o b t a i n e d ; t h e y e x h i b i t n u m e r o u s m o l e c u l a r f r a g m e n t s w h i c h h a v e u n d e r g o n e c o n s i d e r a b l e r e a r r a n g e m e n t , i n d i c a t i n g o n c e a g a i n t h e c o n s i d e r a b l e b o n d m o b i l i t y o f t h e s e c o mpounds. The i n f r a r e d a n d Raman s p e c t r a o f many o f t h e s e compounds h a v e b e e n r e c o r d e d ; n u m e r o u s b a n d a s s i g n m e n t s w e r e p o s s i b l e b e c a u s e o f t h e c l o s e s i m i l a r i -t i e s o f t h e compounds. - 8 7 -B. EXPERIMENTAL D E T A I L The o r g a n o p h o s p h o r u s - s u l p h u r compounds e x a m i n e d w e r e f o u n d t o he q u i t e a s t r a c t a b l e a s was h o p e d . I n g e n e r a l , t h e s e compounds a r e c r y s t a l l i n e a n d a r e r e a d i l y s o l u b l e i n common s o l v e n t s ; t h e y a r e , h o w e v e r , s e n s i t i v e t o b o t h o x i d a t i o n a n d h y d r o l y s i s a n d s o v i r t u a l l y a l l t h e e x p e r i -m e n t s r e p o r t e d h e r e w e re c a r r i e d o u t i n a n i n e r t a t m o s -p h e r e . I n many c a s e s , s a t i s f a c t o r y m i c r o a n a l y s e s c o u l d be o b t a i n e d o n l y when t h e a n a l y s e s w e r e p e r f o r m e d i n a n i n e r t a t m o s p h e r e , a s s i g n i f i c a n t d e c o m p o s i t i o n was f o u n d t o o c c u r i n t h e b r i e f t i m e r e q u i r e d t o h a n d l e t h e s a m p l e s i n t h e a t m o s p h e r e . P h P C l 2 w i t h H 2 S : ( A l l m a n i p u l a t i o n s a n d r e a c t i o n s w e r e p e r f o r m e d i n v a c u o o r i n a n i t r o g e n a t m o s p h e r e . ) ( i ) P h P C l 2 ( 1 5 . 6 2 gms., 0.087 m o l e s ) was p l a c e d i n a n a u t o c l a v e i n a n i t r o g e n a t m o s p h e r e ; t h e n i t r o g e n was r e m o v e d on a vacuum l i n e a n d a p p r o x i m a t e l y 0.087 m o l e s o f H 2 S (27 cms. p r e s s u r e i n a 5.65 1. g a s b u l b ) w e r e c o n d e n s e d i n t o t h e a u t o c l a v e . The r e a c t i o n m i x t u r e was h e a t e d t o 95°C o v e r n i g h t a n d t h e n c o o l e d . The a u t o c l a v e was o p e n e d a n d a c l e a r p a l e y e l l o w l i q u i d was r e m o v e d . A q u a l i t a t i v e t e s t f o r c h l o r i d e r e v e a l e d t h a t l a r g e a m o u n t s o f u n r e a c t e d p h e n y l d i c h l o r o p h o s p h i n e r e m a i n e d . A n - 8 8 -e x c e s s o f H 2 S was c o n d e n s e d o n t o t h e o i l a t -80 C an d a l l o w e d t o r e m a i n t h e r e f o r t e n h o u r s . L a r g e r o s e t t e s o f w h i t e c r y s t a l s s l o w l y a p p e a r e d a t t h e H 2S - o i l i n t e r f a c e . The h y d r o g e n s u l p h i d e was t h e n pumped o f f a n d t h e c r y s t a l l i n e p r o d u c t was c o l l e c t e d o n s i n t e r e d g l a s s a n d w a s h e d w i t h c y c l o -h e x a n e . A s a m p l e was p u r i f i e d b y s u b l i m a t i o n i n v a c u o a t 1 8 5 ° C P o u n d : C 51.3696 H 3 . 5 6 % m.p. 148°C ( l i t . 8 2 148°C) P h 5 P 3 S 5 r e q u i r e s C 5 1 . 4 2 % H 3 . 5 9 % H n.m.r.: c o m p l e x m u l t i p l e t c e n t r e d a t 2 . 3 T ( i n t . TMS) i n C S 2 . ( i i ) P h P C l 2 a n d H 2 S w e r e a l l o w e d t o r e a c t t o g e t h e r i n a c a r b o n t e t r a c h l o r i d e s o l u t i o n i n t h e p r e s e n c e o f t r i e t h y l a m i n e . I t was h o p e d t h a t t h e t r i e t h y l a m i n e w o u l d a s s i s t t h e r e a c t i o n b y r e m o v a l o f t h e l i b -e r a t e d HOI. G r e a t d i f f i c u l t y was e x p e r i e n c e d i n r e m o v i n g t h e l a s t t r a c e s o f E t 3 N H + C l ~ " f r o m P h ^ P ^ S ^ h o w e v e r a n d t h i s m e t h o d was d i s c a r d e d . ZnS w i t h P h P G l 2 : P h P C l 2 ( 7 . 6 8 3 1 gms., 0.0429 m o l e s ) a n d ZnS ( 4 . 1 7 9 0 gms., 0.0429 m o l e s ) w e r e m i x e d t o g e t h e r u n d e r n i t r o g e n a n d t h e n h e a t e d u n d e r r e f l u x a t t h e b o i l i n g p o i n t o f P h P G l 2 , 222°C, f o r 15 h o u r s . No v i s i b l e r e a c t i o n o c c u r r e d . The m i x t u r e was t h e n c o o l e d a n d d i l u t e d w i t h d r y C C l ^ . U n r e a c t e d ZnS was r e m o v e d b y f i l t r a t i o n a n d r e m o v a l o f -89-C C l ^ i n v a c u o l e f t a n o i l y l i q u i d whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f P h P C l 2 , p r o v i n g t h a t no r e a c t i o n h a d o c c u r r e d . N a 2 S w i t h P h P G l 2 : A n h y d r o u s N a 2 S was p r e p a r e d f r o m t h e e l e m e n t s i n 90 l i q u i d ammonia a c c o r d i n g t o l i t e r a t u r e m e t h o d s . P h P C l 2 ( 7 . 4 3 gms., 0.0415 m o l e s ) a n d N a 2 S ( 3 . 2 3 gms., 0.0415 m o l e s ) w e r e m i x e d t o g e t h e r i n 150 m i s . o f d r y ( L i A l H ^ ) "benzene i n a n i t r o g e n a t m o s p h e r e . The m i x t u r e was h e a t e d t o r e f l u x f o r 24 h o u r s ; a t t h a t t i m e , a s o l u -t i o n s p e c t r u m o f t h e r e a c t i o n m i x t u r e showed no r e a c t i o n . The b e n z e n e was r e m o v e d b y d i s t i l l a t i o n a n d t h e r e a c t a n t s w e r e f u s e d t o g e t h e r a t 222°C f o r two d a y s . E x t r a c t i o n o f t h i s f u s e d mass w i t h b e n z e n e r e s u l t e d i n c l e a r s o l u -t i o n s f r o m w h i c h P h ^ P ^ S ^ c o u l d be i s o l a t e d b y r e m o v a l o f t h e s o l v e n t . P h ^ P ^ S ^ was i d e n t i f i e d b y i t s i n f r a r e d s p e c t r u m ; i t was n o t a l w a y s f o r m e d i n g o o d y i e l d s , h o w e v e r a n d t h e p r e p a r a t i o n o f N a 2 S was cumbersome. C o n -op s e q u e n t l y t h e m e t h o d o f M a i e r , i n v o l v i n g t h e r e a c t i o n o f PhPH" 2 w i t h s u l p h u r , was u s e d f o r r o u t i n e p r e p a r a t i o n o f P h ^ P ^ S j . P h P H 2 w i t h s u l p h u r : PhPR" 2 was p r e p a r e d b y r e d u c t i o n o f P h P ( s ) C l 2 w i t h 91 L i A l H ^ . R e p o r t e d l i t e r a t u r e m e t h o d s ^ f o r t h e p r e p a r a t i o n o f P h P H 2 u s u a l l y i n v o l v e r e d u c t i o n o f P h P C l 2 . H o w e v e r -90-P h P ( S ) C l 2 i s much c h e a p e r a n d v e r y much l e s s o b n o x i o u s t o h a n d l e t h a n i s P h P C l 2 . I n a t y p i c a l r e a c t i o n , L i A l H ^ ( 1 6 . 5 gms., 0.44 m o l e s ) was a d d e d t o 150 m i s . o f d r y ( L i A l H ^ ) e t h e r i n a n i t r o g e n a t m o s p h e r e . The s l u r r y was c o o l e d , w i t h s t i r r i n g , t o 0°C i n a n i c e b a t h . A s o l u -t i o n o f P h P ( S ) C l 2 ( 7 1 gms., 0.34 m o l e s ) i n 50 m i s . o f d r y e t h e r was a d d e d d r o p w i s e t o t h e s l u r r y a t s u c h a r a t e t h a t t h e t e m p e r a t u r e o f t h e s o l u t i o n d i d n o t e x c e e d 5°C. When t h e a d d i t i o n was c o m p l e t e d , t h e r e a c t i o n m i x t u r e was a l l o w e d t o warm t o room t e m p e r a t u r e a n d was s t i r r e d o v e r n i g h t . T h e n 200 m i s . o f 1:1 H C l w e r e a d d e d t o t h e c o o l e d m i x t u r e t o d e s t r o y e x c e s s L i A l H ^ . S t i r r i n g was c o n t i n u e d u n t i l no more g a s e v o l u t i o n was o b s e r v e d . The e t h e r l a y e r was s e p a r a t e d a n d d r i e d w i t h a n h y d r o u s N a 2 S 0 4 a n d t h e n d i s t i l l e d t o g i v e 25.3 gms. o f P h P H 2 ( b . p . 158-161°C). Y i e l d : 6 8 . 3 % P h e n y l p h o s p h i n e a n d s u l p h u r w e r e r e a c t e d t o g e t h e r 8 ? a c c o r d i n g t o t h e m e t h o d o f M a i e r . The s t o i c h i o m e t r y o f t h e r e a c t a n t s i s i m p o r t a n t a s e i t h e r P h ^ P ^ S , P h ^ P ^ S ^ o r P h 2 P 2 S 4 c a n be o b t a i n e d d e p e n d i n g on t h e amount o f s u l p h u r p r e s e n t . E t P C l 2 a n d K 2 S : E t P C l 2 ( 4 . 0 7 gms., 3 1 . 1 mmoles) a n d a n h y d r o u s K 2 S ( 3 . 4 2 gms., 31.1 mmoles) w e r e m i x e d t o g e t h e r i n d r y b e n z e n e i n a n i t r o g e n a t m o s p h e r e . The r e a c t i o n m i x t u r e was h e a t e d u n d e r r e f l u x o v e r n i g h t w i t h s t i r r i n g . B e n z e n e - 9 1 -was t h e n d i s t i l l e d o f f a n d t h e r e a c t a n t s w e r e f u s e d f o r two d a y s . E x t r a c t i o n o f t h e f u s e d mass w i t h d r y "benzene y i e l d e d o n l y a v e r y s m a l l amount o f y e l l o w o i l w h i c h was i n s u f f i c i e n t f o r c h a r a c t e r i z a t i o n . E t P G l 2 a n d N a 2 S : E t P C l 2 ( 5 . 8 2 gms., 44.4 mmoles) a n d a n h y d r o u s N a 2 S ( 3 . 4 6 gms., 44.4 mmoles) w e r e m i x e d t o g e t h e r i n h i g h b o i l i n g (60°-120°) d r y p e t r o l e u m e t h e r i n a n i t r o g e n a t m o -s p h e r e . The r e a c t i o n m i x t u r e became v e r y h o t i m m e d i a t e l y . The m i x t u r e was h e a t e d u n d e r r e f l u x o v e r n i g h t a n d t h e n t h e s o l u t i o n was d e c a n t e d f r o m t h e s o l i d r e s i d u e s . R e m o v a l o f s o l v e n t f r o m t h e f i l t r a t e l e f t b e h i n d o n l y a t r a c e o f o i l y m a t e r i a l whose i n f r a r e d s p e c t r u m showed t h e p r e s e n c e o f E t P G l 2 # On t h e a s s u m p t i o n t h a t t h e r e a c t i o n was i n c o m p l e t e , a n e x c e s s o f a l u m i n u m c h l o r i d e ( 1 3 gms.) was a d d e d t o t h e s o l i d r e s i d u e f o l l o w e d b y a s m a l l v o l u m e o f d r y p e t r o l e u m e t h e r . T h i s m i x t u r e was h e a t e d u n d e r r e f l u x o v e r n i g h t t o y i e l d a c l e a r s o l u t i o n a n d a gum. The s o l u t i o n was d e c a n t e d a n d was f o u n d t o c o n s i s t e n t i r e l y o f s o l v e n t . B e c a u s e o f t h e p o s s i b i l i t y t h a t A l C l ^ h a d c o m p l e x e d E t P C l 2 , i n s t e a d o f r e m o v i n g a c h l o r i d e i o n , t h e gum was f u s e d a t 150°C i n v a c u o o v e r n i g h t t o y i e l d a r e d - b r o w n m i x t u r e . E x t r a c t i o n o f t h i s m i x t u r e w i t h C H 2 C 1 2 y i e l d e d a r e d - b r o w n o i l whose i n f r a r e d s p e c -t r u m d i d n o t c o r r e s p o n d t o a n y l i k e l y compound. T h i s r e a c t i o n was t h e r e f o r e n o t p u r s u e d . - 9 2 -M e P H 2 and S Q : M e P H 2 was p r e p a r e d b y t h e r e d u c t i o n o f M e P ( 0 ) ( O M e ) 2 w i t h L i A l H ^ a c c o r d i n g t o t h e m e t h o d o f S h e l d r i c k 9 2 a n d was p u r i f i e d b y t r a p - t o - t r a p d i s t i l l a t i o n u n t i l t h e v a p o u r p r e s s u r e ( 7 3 mm. a t -63°G) was i n a g r e e m e n t w i t h 93 l i t e r a t u r e d a t a ^ . A m i x t u r e o f b e n z e n e ( 5 m i s . ) a n d s u l p h u r ( 7 . 3 3 gms., 28.6 mmoles) was p l a c e d i n a n a u t o -c l a v e a n d t h e b e n z e n e was d e g a s s e d b y s e v e r a l f r e e z e -t h a w c y c l e s . ( T h e amount o f s u l p h u r u s e d c o r r e s p o n d s t o a 1:2 P:S r a t i o b a s e d on t h e e x p e c t e d y i e l d o f MePH 2.) M e t h y l p h o s p h i n e was c o n d e n s e d i n t o t h e a u t o c l a v e w h i c h was t h e n s e a l e d and p l a c e d i n a n o v e n a t 65°C f o r 12 h o u r s . The a u t o c l a v e was t h e n c o o l e d t o -196°C a n d o p e n e d t o t h e v a c u u m l i n e ; n o n - c o n d e n s a b l e g a s e s w e r e r e m o v e d a n d t h e n t h e a u t o c l a v e was a l l o w e d t o warm t o room t e m p e r a t u r e . C o n d e n s a b l e g a s e s w e r e c o l l e c t e d a t -196°C; t h e p r e s s u r e o f t h e s e g a s e s a t -63°C was a l m o s t one a t m o s p h e r e i n d i -c a t i n g t h a t t h e g a s m i x t u r e was p r e d o m i n a n t l y H 2 S . A n i n f r a r e d s p e c t r u m o f t h i s g a s m i x t u r e d i d r e v e a l b a n d s 94 c h a r a c t e r i s t i c o f M e P H 2 i n d i c a t i n g t h a t t h e r e a c t i o n h a d n o t gone t o c o m p l e t i o n . The a u t o c l a v e was r e s e a l e d a n d t h e n o p e n e d i n a n i t r o g e n a t m o s p h e r e . The p r e s e n c e o f u n r e a c t e d s u l p h u r c o n f i r m e d t h a t t h e r e a c t i o n h a d n o t g o n e t o c o m p l e t i o n . The b e n z e n e s o l u t i o n was d e c a n t e d f r o m t h e u n r e a c t e d s u l p h u r a n d t h e s o l v e n t was r e m o v e d o n t h e v a c u u m l i n e t o g i v e a n a d d i t i o n a l s m a l l amount o f - 9 3 -s u l p h u r a n d a n o i l . The a d d i t i o n o f a s m a l l v o l u m e o f C S 2 c a u s e d p r e c i p i t a t i o n o f a w h i t e p o w d e r w h i l e a t t h e same t i m e d i s s o l v i n g t h e r e s i d u a l s u l p h u r . The w h i t e p o w d e r was f i l t e r e d o f f a n d w a s h e d w i t h C S 2 . I t was o b -s e r v e d t o he e x t r e m e l y h y g r o s c o p i c a n d was t h e r e f o r e r e -c r y s t a l l i z e d t w i c e f r o m b e n z e n e u n d e r n i t r o g e n . F o u n d : C 1 1 . 1 0 % H 2 . 7 3 % m.p. 208-212°C M e 2 P 2 S 4 r e < l u i r e s G 1 0 . 9 1 % H 2 . 8 2 % m.p. 210-212°C ( r e f . 1 H n.m.r.: one d o u b l e t a t 7.50 7", J p f i = 14HZ M e P H 2 a n d S G 1 2 : M e P H 2 was p r e p a r e d a s d e s c r i b e d a b o v e . S u l p h u r d i -c h l o r i d e , S C 1 2 , was f r e s h l y d i s t i l l e d f r o m P C l ^ t o r e m o v e t h e p o s s i b l e i m p u r i t i e s o f s u l p h u r a n d c h l o r i n e . The w e i g h t o f M e P H 2 was d e t e r m i n e d t o be 2.16 gms. ( 4 6 . 0 mmoles) on t h e b a s i s o f i t s p r e s s u r e ( 1 3 . 7 cms.) i n a 5.61 1. g a s s t o r a g e b u l b . T h e r e f o r e t h e c o r r e c t s t o i c h i o -m e t r i c amount o f S C 1 2 ( 4 . 6 5 gms., 46.0 m m o l e s ) was p l a c e d i n a n a u t o c l a v e i n a s m a l l v o l u m e o f b e n z e n e a n d t h e s o l u t i o n was d e g a s s e d b y s e v e r a l f r e e z e - t h a w c y c l e s . The m e t h y l p h o s p h i n e was t h e n c o n d e n s e d i n t o t h e a u t o c l a v e w h i c h was s e a l e d a n d p l a c e d i n a n o v e n a t 85°C f o r 1 5 h o u r s . The a u t o c l a v e was t h e n c o n n e c t e d t o a vacuum l i n e a n d c o o l e d t o -196°C N o n - c o n d e n s a b l e g a s e s w e r e pumped o f f , a nd c o n d e n s a b l e g a s e s w e r e t r a n s f e r r e d t o a s t o r a g e b u l b . The a u t o c l a v e was r e s e a l e d a n d t h e n o p e n e d i n a n i t r o g e n a t m o s p h e r e ; t h e c o n t e n t s o f t h e a u t o c l a v e w e r e - 9 4 -washed o u t w i t h h e n z e n e a n d p l a c e d i n a f l a s k . The s o l v e n t was r e m o v e d o n t h e vacuum l i n e t o g i v e a s m a l l amount o f w h i t e p o w d e r w h i c h was c o l l e c t e d u n d e r n i t r o g e n , w a s h e d w i t h a n h y d r o u s e t h e r a n d t h e n v a c u u m - d r i e d . A n i n f r a r e d s p e c t r u m o f t h i s m a t e r i a l was i d e n t i c a l t o t h a t o f t h e p r e v i o u s l y i d e n t i f i e d M e ^ ^ S ^ . P h P C l 2 a n d K 2 S : A n h y d r o u s K^S was p r e p a r e d i n t h e same way a s h a s b e e n d e s c r i b e d f o r N a 2 S . K 2 S ( 6 . 7 4 gms., 61.2 mmoles) and P h P C l 2 ( 1 0 . 9 5 gms., 61.2 mmoles) w e r e m i x e d t o g e t h e r i n a s m a l l v o l u m e o f b e n z e n e i n a n i t r o g e n a t m o s p h e r e . The s o l v e n t was t h e n r e m o v e d b y d i s t i l l a t i o n a n d t h e r e a c t a n t s f u s e d a t 222°G f o r 48 h o u r s . The r e a c t i o n m i x t u r e was t h e n e x t r a c t e d w i t h d r y b e n z e n e o v e r n i g h t . R e m o v a l o f b e n z e n e o n t h e vacuum l i n e y i e l d e d a s m a l l amount o f p a l e y e l l o w c r y s t a l s . L a r g e n e e d l e - l i k e c r y s t a l s w e r e o b t a i n e d b y p a s s i n g n i t r o g e n s l o w l y o v e r a s a t u r a t e d s o l u t i o n o f t h i s m a t e r i a l i n 1:1 c h l o r o f o r m -a c e t o n e . F o u n d : C 6 2 . 0 4 % H 4 . 3 2 % m.p. 154-6°C P h 4 P 4 S r e q u i r e s C 6 2 . 0 7 % H 4 . 3 1 % m.p. 154-6°C ( r e f . 8 2 ) i H n.m.r.: two m u l t i p l e t s o f e q u a l a r e a c e n t r e d a t 2 . 5 5 T a n d 2.837" ( i n C S 2 , w i t h TMS a s a n i n t e r n a l s t a n d a r d . ) P h P H 2 w i t h P h P ( S ) C l 2 : P h P ( S ) C l 9 ( 3 . 8 4 gms., 18.2 mmoles) was a d d e d t o - 9 5 -P h P H 2 ( 2 . 0 gms., 18.2 mmoles) i n 5 m i s . o f d r y b e n z e n e . The r e a c t a n t s w e r e h e a t e d u n d e r r e f l u x o v e r n i g h t a n d t h e n t h e s o l v e n t was r e m o v e d b y d i s t i l l a t i o n . The r e a c t a n t s w e r e h e a t e d t o g e t h e r f o r a n a d d i t i o n a l 24 h o u r s t o y i e l d a d e e p y e l l o w s o l u t i o n . Upon c o o l i n g , v i r t u a l l y t h e e n t i r e m i x t u r e s o l i d i f i e d t o a mass o f p a l e y e l l o w c r y s t a l s . The c r y s t a l s w e r e c o l l e c t e d i n a n i t r o g e n a t m o s p h e r e a n d w e r e i d e n t i f i e d a s Ph^P^S b y t h e i r m e l t i n g p o i n t a n d b y t h e i r i n f r a r e d s p e c t r u m . Ph^P^S-j w i t h I,,: ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) I o d i n e ( 0 . 2 8 7 gms., 1.13 mmoles) was a d d e d i n one p o r t i o n t o a s l u r r y o f P h ^ P ^ S ^ ( 0 . 4 2 9 7 gms., 1.13 mmoles) i n 15 m i s . o f b e n z e n e . The p u r p l e c o l o u r o f i o d i n e i m m e d i a t e l y d i s a p p e a r e d a n d a b r i g h t y e l l o w s o l u t i o n r e s u l t e d . The r e a c t i o n m i x t u r e was s t i r r e d o v e r n i g h t a t r o o m t e m p e r a t u r e . R e m o v a l o f b e n z e n e o n a v a c uum l i n e a f f o r d e d t i n y y e l l o w c r y s t a l s . T h i s p r o d u c t was r e -c r y s t a l l i z e d f r o m b e n z e n e t o g i v e b l o c k - s h a p e d c r y s t a l s . P o u n d : C 4 1 . 9 6 % H 2 . 9 1 % m.p. 242°C ( s h a r p ) P h 2 P 2 S 4 r e q u i r e s 0 4 1 . 8 6 % H 2 . 9 3 % m.p. 233-243°C ( r e f . 8 6 ) P h^P^S w i t h I 2 : ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) I o d i n e ( 0 . 4 8 9 3 gms., 1.93 mmoles) was a d d e d i n one p o r t i o n t o a s l u r r y o f Ph^P^S ( 0 . 9 1 3 6 gms., 1.93 mmoles) i n 15 m i s . o f b e n z e n e . The p u r p l e c o l o u r o f i o d i n e - 9 6 -i m m e d i a t e l y d i s a p p e a r e d a n d a b r i g h t y e l l o w - o r a n g e s o l u -t i o n r e s u l t e d . The r e a c t i o n m i x t u r e was s t i r r e d a t r oom t e m p e r a t u r e u n t i l a l l t h e s o l i d i o d i n e h a d d i s a p p e a r e d . B e n z e n e was t h e n r e m o v e d on a vacuum l i n e t o y i e l d a mass o f o r a n g e m a t e r i a l . T h i s m a t e r i a l was c r y s t a l l i z e d f r o m b e n z e n e - c h l o r o f o r m ( 1 0 : 1 ) t o y i e l d b r i l l i a n t o r a n g e n e e d l e s . P o u n d : 0 3 0 . 5 3 % H 2 . 0 0 % m.p. 183-185°0 P h 2 P 2 I 2 r e q u i r e s C 3 0 . 6 5 % H 2 . 1 3 % m.p. 178-180°C ( r e f . 9 5 ) A b e t t e r y i e l d o f P h 2 P 2 I 2 was o b t a i n e d when Ph^P^S a n d i o d i n e w e r e a l l o w e d t o r e a c t i n a 1:2 m o l a r p r o p o r t i o n . P h ^ P ^ S ^ w i t h P B u ^ : ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) A m i x t u r e o f P h ^ P ^ S ^ ( 0 . 3 8 0 4 gms., 0.904 mmoles) a n d Bu^P ( 0 . 1 8 2 6 gms., 0.904 mmoles) was h e a t e d u n d e r r e f l u x i n x y l e n e o v e r n i g h t . The s o l v e n t was r e m o v e d on a v acuum l i n e t o y i e l d p a l e y e l l o w c r y s t a l s whose i n f r a r e d s p e c t r u m was i d e n t i c a l w i t h t h a t o f a n a u t h e n t i c s a m p l e o f P h . P . S . 4 4 P h^P^S w i t h P B u ^ : ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a . n i t r o g e n a t m o s p h e r e . ) ( i ) A m i x t u r e o f Ph^P^S ( 0 . 3 7 5 2 gms., 0.817 m moles) a n d P B u ^ ( 0 . 1 6 5 gms., 0.817 m moles) was d i s s o l v e d i n 15 m i s . o f b e n z e n e a n d h e a t e d u n d e r r e f l u x o v e r n i g h t . R e m o v a l o f t h e s o l v e n t on a vacuum l i n e y i e l d e d u n -r e a c t e d Ph^P^S w h i c h was i d e n t i f i e d b y i t s i n f r a r e d s p e c t r u m . - 9 7 -( i i ) The e x p e r i m e n t was r e p e a t e d i n b o i l i n g x y l e n e t o e n c o u r a g e r e a c t i o n . Ph^P^S ( 0 . 2 8 9 0 gms., 0.630 mmoles) a n d P B u ^ ( 0 . 1 2 7 2 gms., 0.630 mmoles) w e r e h e a t e d u n d e r r e f l u x i n x y l e n e f o r 24 h o u r s b u t a g a i n no r e a c t i o n o c c u r r e d . U n r e a c t e d Ph^P^S was i d e n t i -f i e d b y i t s i n f r a r e d s p e c t r u m . P h ^ P ^ S ^ w i t h Hg: ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) ( i ) A s o l u t i o n o f P h ^ P ^ S ^ i n b e n z e n e was s t i r r e d w i t h a l a r g e e x c e s s o f m e r c u r y f o r 16 h o u r s - b y w h i c h t i m e a s m a l l amount o f w h i t e s o l i d h a d a p p e a r e d . T h i s w h i t e m a t e r i a l a n d t h e b e n z e n e s o l u t i o n w e r e d e c a n t e d f r o m t h e m e r c u r y , a n d t h e n t h e s o l i d m a t e r i a l was i s o l a t e d b y f i l t r a t i o n . The s o l i d was v a c u u m - d r i e d a n d i t s i n f r a r e d s p e c t r u m was r e c o r d e d . B e n z e n e was r e m o v e d f r o m t h e f i l t r a t e o n a v a c u um l i n e t o y i e l d a c l e a r o i l . A d d i t i o n o f a s m a l l amount o f a n h y d r o u s e t h e r c a u s e d p r e c i p i t a t i o n o f a n o f f - w h i t e p o w d e r whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f t h e p r e v i o u s l y i s o l a t e d s o l i d . I t a p p e a r s t h e r e f o r e t h a t o n l y one p r o d u c t i s o b t a i n e d u n d e r t h e s e c o n -d i t i o n s . The t w o f r a c t i o n s o f s o l i d w e r e c o m b i n e d and e x t r a c t e d w i t h CS,,. The w h i t e p o w d e r o b t a i n e d i n t h i s m a n n e r was d r i e d i n v a c u o P o u n d : C 2 8 . 4 0 % H 2.28% m.p. 210-220°C The e m p i r i c a l f o r m u l a o f P h ^ p ^ H g w o u l d r e q u i r e C 2 8 . 1 2 % a n d H 1.97%. - 9 8 -Th e mass s p e c t r u m c o n f i r m s t h e p r e s e n c e o f e l e m e n t a l m e r c u r y h u t no m e r c u r y - c o n t a i n i n g f r a g m e n t s w e r e o b s e r v e d . The b a s e p e a k o f t h e mass s p e c t r u m o c c u r s a t m/e 172 a n d i s c o n s i d e r e d t o be P h P S * . The i n f r a r e d s p e c t r u m e x h i b i t s s t r o n g a b s o r p t i o n a t 1 4 3 8 , 1 0 9 0 , 7 6 0 , 7 4 2 , 6 7 2 , 6 2 8 , 6 0 7 , 5 6 9 , 495 a n d — 1 — 1 470 cm . The b a n d a t 628 cm i s t h e s t r o n g e s t a n d b r o a d e s t o f t h e l o w f r e q u e n c y v i b r a t i o n s a n d i s c o n -s i d e r e d t o b e due t o P=S s t r e t c h i n g . The Raman s p e c t r u m e x h i b i t s s t r o n g b a n d s a t 1 0 0 1 , 5 0 3 , 336 _ -i and 263 cm . T h i s compound r e m a i n s i n c o m p l e t e l y c h a r a c t e r i z e d . ( i i ) The r e a c t i o n o f P h ^ P ^ S ^ w i t h m e r c u r y was r e p e a t e d a s b e f o r e e x c e p t t h a t v i g o r o u s s t i r r i n g was c o n t i n u e d f o r 22 h o u r s . A f i n e w h i t e p r e c i p i t a t e h a d a g a i n f o r m e d a n d i t s i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f t h e compound i s o l a t e d i n p a r t ( i ) . The b e n z e n e f i l t r a t e was c o n c e n t r a t e d b y r e m o v a l o f b e n z e n e on a vacuum l i n e t o y i e l d s m a l l y e l l o w c r y s t a l s . A n i n f r a r e d s p e c t r u m o f t h e s e c r y s t a l s p r o v e d t h a t t h e y w e r e P h ^ P ^ S . I t a p p e a r s , t h e r e f o r e , t h a t t h e m e r c u r y - c o n t a i n i n g compound may be a n i n t e r m e d i a t e b e t w e e n P h 5 P 5 S 5 a n d P h ^ P ^ S . P h 2 P 2 S 4 w i t h Hg: ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e ) A s l u r r y o f P h ? P 9 S A i n b e n z e n e was s t i r r e d v i g o r o u s l y - 9 9 -w i t h a b o u t 3 m i s . o f m e r c u r y u n t i l a l l t h e Th^P^S^ h a d d i s a p p e a r e d ( a b o u t 25 h o u r s . ) A t t h e end o f t h i s p e r i o d a h e a v y p r e c i p i t a t e o f HgS h a d f o r m e d . The r e a c t i o n m i x t u r e was f i l t e r e d a n d t h e s o l i d s w e r e w a s h e d w i t h C S 2 ( 3 x 10 m i s . ) S o l v e n t was r e m o v e d f r o m t h e f i l t r a t e o n t h e vacuum l i n e t o y i e l d a c l e a r o i l ; t h e a d d i t i o n o f a n h y d r o u s e t h e r i n d u c e d p r e c i p i t a t i o n o f a w h i t e s o l i d whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f t h e m e r c u r y - c o n t a i n i n g compound i s o l a t e d f r o m t h e r e a c t i o n o f P h ^ P ^ S ^ w i t h m e r c u r y . P h 5 P 5 S 5 w i t h W ( 0 0 ) 6 : P h 5 P 5 S 5 ( 0 . 0 7 7 0 gms., 0.183 mmoles) a n d W ( C 0 ) 6 ( 0 . 1 3 0 3 gms., 0.183 mmoles) w e r e m i x e d t o g e t h e r i n t e t r a -h y d r o f u r a n a n d h e a t e d u n d e r r e f l u x i n a n i t r o g e n a t -m o s p h e r e f o r 36 h o u r s . No v i s i b l e r e a c t i o n o c c u r r e d a n d a n i n f r a r e d s p e c t r u m o f t h e s o l u t i o n showed o n l y one p e a k a t 1970 cm , c h a r a c t e r i s t i c o f W ( C 0 ) g . T h e r e f o r e no r e a c t i o n o c c u r r e d . P h 4 P 4 S w i t h W ( C 0 ) 6 : P h 4 P 4 S ( 0 . 0 0 7 9 gms., 0.017 mmoles) a n d W ( C 0 ) 6 ( 0 . 0 0 5 9 gms., 0.017 mmoles) w e r e h e a t e d u n d e r r e f l u x i n t e t r a h y d r o f u r a n f o r 36 h o u r s i n a n i t r o g e n a t m o s p h e r e . A t t h e end o f t h i s p e r i o d , o n l y one s t r o n g p e a k was o b s e r v e d i n t h e C=0 s t r e t c h i n g r e g i o n a n d i t was c h a r a c t e r i s t i c o f W(CO)/- i m p l y i n g t h a t no r e a c t i o n h a d o c c u r r e d . - 1 0 0 -P h 5 P 3 S 3 w i t h M o ( G 0 ) 6 : A m i x t u r e o f P h 3 P 3 S 3 a n d M o ( G 0 ) g w e r e f u s e d t o g e t h e r u n d e r n i t r o g e n t o g i v e a b r o w n i s h - b l a c k m a s s . E x t r a c t i o n o f t h i s mass w i t h c h l o r o f o r m y i e l d e d a s o l u t i o n whose i n f r a r e d s p e c t r u m showed o n l y one C=0 s t r e t c h , t h a t c h a r a c t e r i s t i c o f M o ( C 0 ) g , p r o v i n g t h a t no c o o r d i n a t i o n c o m p l e x h a d b e e n f o r m e d . The b l a c k m a t e r i a l o b s e r v e d i s u n d o u b t e d l y M 0 S 2 . P h 3 P 3 S 3 w i t h R h C l ( P h 3 P ) 3 : ( A l l m a n i p u l a t i o n s w e r e p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) P h 3 P 3 S 3 ( 0 . 1 3 2 2 gms., 0.315 mmoles) a n d R h C l ( P h 3 P ) 3 ( 0 . 2 8 5 4 gms., 0.315 m moles) w e r e m i x e d t o g e t h e r i n 15 m i s . o f d r y b e n z e n e a n d h e a t e d u n d e r r e f l u x f o r 24 h o u r s i n a n i t r o g e n a t m o s p h e r e . A t t h e end o f t h i s p e r i o d , t h e s o l u t i o n was c o n c e n t r a t e d i n v a c u o a n d a n e x c e s s o f l i g h t p e t r o l e u m e t h e r was a d d e d t o p r e c i p i t a t e a p a l e b r o w n p o w d e r whose i n f r a r e d s p e c t r u m was s t r o n g l y s i m i l a r t o t h a t o f t h e s t a r t i n g m a t e r i a l R h C l ( P h 3 P ) 3 . The m o t h e r l i q u o r s o f t h i s m i x t u r e w e r e e v a p o r a t e d t o d r y n e s s t o y i e l d c r y s t a l s whose i n f r a r e d s p e c t r u m was i d e n t i c a l t o t h a t o f a n a u t h e n t i c s a m p l e o f t r i p h e n y l p h o s p h i n e s u l p h i d e . The f o r m a t i o n o f P h 3 P = S i m p l i e s t h a t P h 3 P 3 S 3 h a s e i t h e r d e -c omposed o r r e a r r a n g e d and t h i s r e a c t i o n was n o t p u r s u e d . P h 2 P 2 I 2 w i t h E t S H : A s l u r r y o f P h 2 P 2 I 2 ( 0 . 3 0 1 6 gms., 0.642 m m o l e s ) i n - 1 0 1 -20 m i s . o f b e n z e n e was s t i r r e d u n d e r n i t r o g e n a t r oom t e m p e r a t u r e i n a f l a s k f i t t e d w i t h a s e p t u m c a p . E t S H ( 9 5 m i c r o l i t r e s , 1.284- mmoles) was a d d e d d r o p w i s e v i a s y r i n g e t h r o u g h t h e s e p t u m . The m i x t u r e was s t i r r e d f o r 1 h o u r a t r oom t e m p e r a t u r e a n d t h e n h e a t e d u n d e r r e f l u x f o r t e n m i n u t e s . R e m o v a l o f s o l v e n t o n a v a c u u m l i n e r e s u l t e d i n p r e c i p i t a t i o n o f a y e l l o w s o l i d w h i c h was i d e n t i f i e d a s P h g P g l ^ h y i t s m e l t i n g p o i n t a n d b y i t s Raman s p e c t r u m . T h e r e f o r e no r e a c t i o n o c c u r r e d . P h 2 P 2 I 2 w i t h S g : ( A l l m a n i p u l a t i o n s w e r e p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) P h 2 P 2 I 2 ( 0 . 5 9 4 9 gms., 1.27 mmoles) a n d S g ( 0 . 0 8 0 0 gms., 0.313 mmoles) w e r e m i x e d t o g e t h e r i n b e n z e n e a n d h e a t e d u n d e r r e f l u x f o r 25 h o u r s . R e m o v a l o f p a r t o f t h e s o l v e n t o n t h e vacuum l i n e c a u s e d p r e c i p i t a t i o n o f P h 2 P 2 I 2 w h i c h was i d e n t i f i e d b y i t s m e l t i n g p o i n t a n d b y i t s Raman s p e c t r u m . E l e m e n t a l s u l p h u r was r e c o v e r e d b y c o n c e n t r a t i o n o f t h e m o t h e r l i q u o r s a n d was i d e n t i -f i e d b y i t s m e l t i n g p o i n t , 112°C. FLUOROPHENYL D E R I V A T I V E S ; ( A l l m a n i p u l a t i o n s p e r f o r m e d i n a n i t r o g e n a t m o s p h e r e . ) The p h o s p h i n e s m - F C g H 4 P H 2 a n d ja-FCgH^PH,, w e r e u s e d t o p r e p a r e t h e f l u o r o p h e n y l d e r i v a t i v e s o f ( P h P ) n , P h ^ P ^ S , P h 5 P 5 S 3 a n d P h ^ S ^ . The f l u o r o p h e n y l d e r i v a -t i v e s o f P h 2 P 2 I 2 were p r e p a r e d b y t h e r e a c t i o n o f i o d i n e w i t h t h e f l u o r o p h e n y l d e r i v a t i v e s o f Ph^P^S o r -102-( P h P ) n . The s y n t h e s e s o f m - F C 6 H 4 P H 2 a n d j j - F C g H ^ P B ^ a r e o u t l i n e d h e l o w . T £ - F C 6 H 4 P C 1 2 : T h i s was p r e p a r e d f r o m t h e r e a c t i o n o f f l u o r o b e n z e n e w i t h p h o s p h o r u s t r i c h l o r i d e i n t h e p r e s e n c e o f a l u m i n u m q g t r i c h l o r i d e a c c o r d i n g t o t h e m e t h o d o f S c h i n d l b a u e r . £ - F C 6 H 4 P H 2 ; The m e t h o d e m p l o y e d was e s s e n t i a l l y t h a t o f S c h i n d l b a u e r ^ ' e x c e p t t h a t t h e a d d i t i o n o f p _ - F C g H 4 P C l 2 t o a n e t h e r e a l s u s p e n s i o n o f L i A l H 4 was c a r r i e d o u t i n s u c h a m a n n e r t h a t t h e t e m p e r a t u r e o f t h e r e a c t i o n m i x t u r e d i d n o t e x c e e d 0°C. The y i e l d o f p_-FC 6H" 4PH 2 ( 1 5 . 3 gms., 50%) i s somewhat i m p r o v e d b y t h i s m e t h o d ( l i t . 3 1 4 5 % . ) S i g n i f i c a n t a m o u n t s o f ( p _ - F C g H 4 P ) n a r e f o r m e d d u r i n g t h e r e d u c t i o n o f p _ - F C g H 4 P C l 2 , t h u s a c c o u n t i n g f o r t h e r a t h e r l o w y i e l d o f p _ - F C 6 H 4 P H 2 . The b o i l i n g p o i n t o f p_-FCgH 4PH 2 was o b s e r v e d t o be 154-158°G ( l i t . 9 7 154-155°C). A 1 H n.m.r. s p e c t r u m o f p_-FCgH 4PH 2 shows a d o u b l e t f o r t h e p h o s p h i n e h y d r o g e n s c e n t r e d a t 6.85 T , J p H = 202 Hz ( l i t . 1 0 0 199 Hz.) The p h e n y l r e s o n a n c e i s c e n t r e d a t 3.42 p.p.m. A 56.4 MHz 1 q ^F n.m.r. s p e c t r u m i n d i c a t e d t h a t o n l y one t y p e o f f l u o r i n e was p r e s e n t . - 1 0 3 -( £ - P 0 6 H 4 P ) n : D u r i n g t h e p r e p a r a t i o n o f jD-FCgH^PHg a w h i t e s o l i d was a l s o f o r m e d . The s o l i d was r e m o v e d b y f i l t r a t i o n a n d e x -t r a c t e d w i t h b e n z e n e t o g i v e l a r g e w e l l - f o r m e d c r y s t a l s . A n a l y t i c a l r e s u l t s r e v e a l e d t h e p r e s e n c e o f e s s e n t i a l l y one m o l e o f b e n z e n e p e r m o l e o f c y c l o p o l y p h o s p h i n e ; t h e r e f o r e , t h e c r y s t a l s w e r e p o w d e r e d a n d d r i e d i n v a c u o w i t h h e a t i n g (100°C) f o r s e v e r a l h o u r s . F o u n d : C 5 6 . 9 2 % H 3 . 2 1 % m.p. 225-230° ( £ - F C 6 H 4 P ) n r e q u i r e s C 5 7 . 1 5 % H 3 . 2 0 % The p _ - f l u o r o p h e n y l c y c l o p o l y p h o s p h i n e s y s t e m i s a p p a r e n t l y 84 a s c o m p l e x a s t h a t o f p h e n y l c y c l o p o l y p h o s p h i n e . 97 S c h i n d l b a u e r ^ ' r e p o r t s t h e m e l t i n g p o i n t o f ( p _ - F C g H 4 P ) n a s 167-169°C when r e c r y s t a l l i z e d f r o m t e t r a h y d r o f u r a n a n d w a t e r , a nd a s 196-197°C when r e c r y s t a l l i z e d f r o m b e n z e n e -e t h y l a c e t a t e . The d i f f e r e n t v a l u e o b t a i n e d h e r e i n d i -c a t e s t h a t s e v e r a l m o d i f i c a t i o n s o f ( p _ - F C g H 4 P ) n e x i s t . ( £ - F C 6 H 4 P ) 4 S : p_-FCgH4PH"2 ( 4 . 6 3 8 9 gms., 36.3 mmoles) a n d s u l p h u r ( 1 . 1 5 4 6 gms., 4.51 mmoles) w e r e r e a c t e d t o g e t h e r i n 8 2 a c c o r d a n c e w i t h t h e m e t h o d p u b l i s h e d b y M a i e r . S o l v e n t was r e m o v e d i n v a c u o t o y i e l d p a l e y e l l o w c r y s t a l s w h i c h w e r e r e c r y s t a l l i z e d t w i c e f r o m b e n z e n e , p o w d e r e d a n d d r i e d a t 85°G f o r 2 h o u r s i n v a c u o . F o u n d : C 5 3 . 5 5 % H 3 . 2 0 % m.p. 194-196°C ( p _ - F C f i H 4 P ) A S r e q u i r e s C 5 3 . 7 3 % H 2 . 9 9 % -104-( £-FC 6H 4PS) 3: £-PCgH 4PH 2 (4.06 gms., 31.7 mmoles) and sulphur (2.03 gms., 7.93 mmoles) were reacted together i n aCCOrd-cs p ance with the method published hy Maier . Solvent was removed in vacuo to yield a white powder which was crystallized twice from benzene, powdered and dried in  vacuo at 80°C for 3 hours. Found: C 45.31% H 2.66% m.p. 115-117°C (p_-FC6H4PS)3 requires C 45.57% H 2.53% ( £-FC 6H 4PS 2) 2: (p_-FCgH4PS)3 (0.7610 gms., 1.61 mmoles) and sulphur (0.1528 gms., 0.597 mmoles) were heated under reflux in toluene for 48 hours. Solvent was removed i n vacuo to yield yellow crystals which were recrystallized from benzene, powdered and dried i n vacuo at 110°C for 2 hours. Found: C 37.55% H 2.35% m.p. 203-206°C (p_-FC 6H 4PS 2) 2 requires C 37.89% H 2.11% (p_-F0 6H 4PI) 2: (p_-FC6H4P)n (0.5197 gms.) and iodine (0.5220 gms.) were stirred together in benzene at room temperature. The solution was f i l t e r e d to remove a small amount of unreacted (p_-FCgH4P)n and then the solvent was removed i n vacuo to yield an orange powder which was crystallized from cyclo-hexane. The crystals were collected on sintered glass and vacuum-dried. - 1 0 5 -F o u n d : m.p. 156-159°C ( l i t . 9 5 138-140°C) 31 P n.m.r.: s i n g l e t a t +21.8 p.p.m. r e l a t i v e t o e x t e r n a l P 4 ° 6 -The s y n t h e s i s o f m-FCgH^PR^ e s s e n t i a l l y f o l l o w s t h e m e t h o d p u b l i s h e d b y S c h i n d l b a u e r a n d P r i k o s z o v i c h 9 8 . ( N E t 2 ) 2 P C l : T h i s was p r e p a r e d b y t h e m e t h o d p u b l i s h e d b y C h a n t r e l l e t a l 9 9 . ( N E t 2 ) 2 P ( m - F C 6 H 4 ) : m - F C g H ^ L i ( 0 . 7 5 m o l e s ) was p r e p a r e d b y a d d i t i o n o f 0.75 m o l e s o f n - B u L i t o 0.75 m o l e s o f m-FCgH^Br i n 200 m i s , o f a n h y d r o u s e t h e r a t -78°C. ( N E t 2 ) 2 P C l ( 0 . 6 7 m o l e s ) was t h e n a d d e d d r o p w i s e t o t h e s o l u t i o n o f m - F C g H ^ L i w i t h s t i r r i n g . I m m e d i a t e l y a f i n e w h i t e p r e c i p i t a t e o f L i C l was f o r m e d . A d d i t i o n o f ( N E t 2 ) 2 P C l was c a r r i e d o u t o v e r a p e r i o d o f s e v e r a l h o u r s a n d t h e n t h e m i x t u r e was a l l o w e d t o warm t o room t e m p e r a t u r e . L i C l was r e m o v e d b y f i l t r a -t i o n i n t h e o p e n a n d t h e s o l v e n t s w e r e r e m o v e d b y d i s t i l -l a t i o n t o y i e l d a d a r k b r o w n o i l . T h i s o i l was v a c u u m -d i s t i l l e d t o y i e l d 7 3 gms. ( 4 0 % ) o f c o l o u r l e s s ( N E t 2 ) 2 P ( m - F C 6 H 4 ) , b . p . 140-147°C, 9.5 mm. ( l i t . 9 8 b . p . 147°C, 10 mm.) m - F C 6 H 4 P C l 2 : T h i s was p r e p a r e d f r o m ( N E t 2 ) 2 P ( m - F C g H 4 ) b y t h e a c t i o n - 1 0 6 -o f H C l i n a c c o r d a n c e w i t h t h e m e t h o d p u b l i s h e d b y S c h i n d l b a u e r 9 8 . The b o i l i n g p o i n t o f m - F C 6 H 4 P C l 2 was f o u n d t o be 97-107°C, 20 mm. ( l i t . 9 8 99-101°C, 20 mm.) A 9 4 . 1 MHz f l u o r i n e s p e c t r u m e x h i b i t e d o n l y one f l u o r i n e m u l t i p l e t . m - F C 6 H 4 P H 2 : The r e d u c t i o n o f m - F C 6 H 4 P C l 2 b y L i A l H ^ r e s u l t s i n a r a t h e r l o w ( 3 8 % ) y i e l d o f m-FCgH^PH,, a c c o r d i n g t o t h e 98 p u b l i s h e d m e t h o d . The c a u s e o f s u c h a l o w y i e l d i s u n -d o u b t e d l y c y c l o p o l y p h o s p h i n e f o r m a t i o n a n d t h e r e f o r e t h e r e d u c t i o n was c a r r i e d o u t w i t h a l a r g e e x c e s s o f L i A l H ^ . I n a d d i t i o n , t h e r e a c t i o n m i x t u r e was k e p t v e r y c o l d a n d a d d i t i o n o f m-FCgH^PCl,, was c a r r i e d o u t v e r y s l o w l y . L i A l H ^ ( 9 . 2 gms., 0.242 m o l e s ) was a d d e d t o 250 m i s . o f d r y e t h e r a n d c o o l e d t o -5°C i n a n i c e - s a l t b a t h . A s o l u t i o n o f m - F C 6 H 4 P C l 2 ( 4 3 gms., 0.218 m o l e s ) i n 75 m i s . o f d r y e t h e r was a d d e d d r o p w i s e o v e r a p e r i o d o f 8 h o u r s s u c h t h a t t h e t e m p e r a t u r e o f t h e r e a c t i o n s o l u t i o n d i d n o t e x c e e d 0°G. The m i x t u r e was a l l o w e d t o warm t o room t e m p -e r a t u r e o v e r n i g h t a n d t h e n e x c e s s L i A l H ^ was d e s t r o y e d b y a d d i t i o n o f 1:1 h y d r o c h l o r i c a c i d . The e t h e r l a y e r was t h e n s e p a r a t e d , d r i e d w i t h N a 2 S 0 4 a n d t h e e t h e r was r e -moved b y d i s t i l l a t i o n t o y i e l d a p a l e y e l l o w o i l y l i q u i d . T h i s l i q u i d was v a c u u m - d i s t i l l e d t o y i e l d 16.4 gms. ( 6 1 % ) o f m - F C 6 H 4 P H 2 , b.p. 54-56°C, 21 mm. ( l i t . 9 8 52-53°C, 21 mm.) - 1 0 7 -A 'H n.m.r. s p e c t r u m o f m-FCgH^PH,, shows t h a t t h e p h o s p h i n e h y d r o g e n r e s o n a n c e o c c u r s a s a d o u b l e t c e n t r e d a t 6.17 7", J p H = 202 Hz. The p h e n y l r e s o n a n c e o c c u r s a s a m u l t i p l e t c e n t r e d a t 3 . 0 0 T . A 9 4 . 1 MHz f l u o r i n e n.m.r. s p e c t r u m showed t h a t o n l y one t y p e o f f l u o r i n e was p r e s e n t . ( m - F 0 6 H 4 P ) 4 S : m - F C 6 H 4 P H 2 ( 2 . 5 3 2 0 gms., 19.8 mmoles) a n d s u l p h u r ( 0 . 6 3 4 8 gms., 2.48 m m o l e s ) w e r e r e a c t e d t o g e t h e r i n 8 2 a c c o r d a n c e w i t h t h e m e t h o d p u b l i s h e d b y M a i e r . S o l v e n t was r e m o v e d i n v a c u o t o y i e l d p a l e y e l l o w c r y s t a l s w h i c h w e r e r e c r y s t a l l i z e d f r o m b e n z e n e , p o w d e r e d a n d d r i e d i n v a c u o a t 110°C f o r 3 h o u r s . F o u n d : C 5 3 . 3 7 % H 2 . 9 8 % m.p. 173-175°C ( m - F C 6 H 4 P ) 4 S r e q u i r e s C 5 3 . 7 3 % H 2 . 9 9 % ( m - F C 6 H 4 P S ) 3 : m - F C g H 4 P H 2 ( 1 . 8 4 7 4 gms., 14.4 mmoles) a n d s u l p h u r ( 0 . 9 2 5 5 gms., 3.62 mmoles) w e r e r e a c t e d t o g e t h e r i n 82 a c c o r d a n c e w i t h t h e m e t h o d p u b l i s h e d b y M a i e r . S o l v e n t was r e m o v e d i n v a c u o t o y i e l d a w h i t e p o w d e r w h i c h was c r y s t a l l i z e d f r o m b e n z e n e , p o w d e r e d and d r i e d i n v a c u o a t 100° f o r 3 h o u r s . F o u n d : C 4 5 . 5 4 % H 2 . 5 5 % m.p. 142-145°C ( m - F 0 6 H 4 P S ) 3 r e q u i r e s C 4 5 . 5 7 % H 2 . 5 3 % - 1 0 8 -( m - F C 6 H 4 P S 2 ) 2 : m - F C g H 4 P H 2 ( 1 . 8 3 9 7 gms., 14.4 mmoles) a n d s u l p h u r ( 1 . 3 8 gms., 5.4 mmoles) w e r e r e a c t e d t o g e t h e r i n a c c o r d -8 2 a n c e w i t h t h e m e t h o d p u b l i s h e d b y M a i e r . S o l v e n t was r e m o v e d i n v a c u o t o y i e l d y e l l o w c r y s t a l s w h i c h w e r e r e -c r y s t a l l i z e d f r o m b e n z e n e , p o w d e r e d a n d d r i e d i n v a c u o a t 100°C f o r 3 h o u r s . F o u n d : C 3 7 . 5 5 % H 2 . 4 0 % m.p. 225-230°C ( m F C 6 H 4 P S 2 ) 2 r e q u i r e s C 3 7 . 8 9 % H 2 . 1 1 % ( m - F C 6 H 4 P I ) 2 : ( m - F C 6 H 4 P ) 4 S ( 1 . 8 3 0 5 gms., 3.4 mmoles) a n d i o d i n e ( 1 . 7 1 6 0 gms., 6.8 mmoles) w e r e s t i r r e d t o g e t h e r i n c y c l o -h e x a n e t o y i e l d a n o r a n g e p r e c i p i t a t e w h i c h was c r y s t a l -l i z e d f r o m c y c l o h e x a n e a n d v a c u u m - d r i e d f o r 1 h o u r a t room t e m p e r a t u r e . F o u n d : G 2 8 . 3 9 % H 1 . 8 0 % m.p. 110-112°C ( m - F C 6 H 4 P I ) 2 r e q u i r e s C 2 8 . 4 6 % H 1 . 5 8 % ( m - F C 6 H 4 P ) n : m - F C 6 H 4 P H 2 ( 1 . 2 2 gms., 8.84 mmoles) a n d m - F C 6 H 4 P C l 2 ( 1 . 7 4 gms., 8.84 mmoles) were h e a t e d u n d e r r e f l u x i n h i g h b o i l i n g (65-110°) p e t r o l e u m e t h e r t o f o r m a w h i t e p o w d e r . T h i s compound i s e x t r e m e l y s o l u b l e i n a l l o t h e r s o l v e n t s t h a t h a v e b e e n t e s t e d a n d was t h e r e f o r e d i f f i c u l t t o c r y s t a l l i z e . A s a m p l e o f t h e w h i t e p o w d e r was d r i e d - 1 0 9 -i n v a c u o a t 70°C f o r 7 h o u r s . F o u n d : C 5 6 . 7 5 % H 3 . 4 0 % m.p. 88-92°C ( m - F C 6 H " 4 P ) n r e q u i r e s C 5 7 . 1 5 % H 3 . 2 0 % FLUORINE N.M.R. SPECTRA: 19 The F n.m.r. s p e c t r a o f t h e s e f l u o r o p h e n y l d e r i v a t i v e s w e r e r e c o r d e d u s i n g a V a r i a n X L - 1 0 0 n.m.r. s p e c t r o m e t e r o p e r a t i n g a t 94.07 MHz. A l l s p e c t r a w e r e r e c o r d e d u s i n g d i l u t e s o l u t i o n s i n C D C l ^ w i t h f l u o r o -b e n z e n e a s a n i n t e r n a l s t a n d a r d . F o u r i e r t r a n s f o r m t e c h n i q u e s w e r e r e q u i r e d f o r t h e compounds ( m - F C g H ^ P j ^ S , c o u l d n o t he o b t a i n e d due t o t h e e x t r e m e i n s o l u b i l i t y o f t h i s compound. S i n c e a l l t h e s p e c t r a w e r e r e c o r d e d u s i n g s o l u t i o n s i n C D C l ^ , t h e d e g r e e o f s o l v e n t - s o l u t e i n t e r a c t i o n w i l l h o p e f u l l y be m i n i m i z e d . To o b t a i n some i d e a o f t h e s o l v e n t e f f e c t , t h e f l u o r i n e s p e c t r a o f p _ - F C g H 4 P C l 2 a n d o f m - F C g H 4 P H 2 w e r e o b t a i n e d i n d e u t e r o c h l o r o f o r m , c y c l o -h e x a n e a n d b e n z e n e . The c h e m i c a l s h i f t s ( r e l a t i v e t o i n t e r n a l f l u o r o b e n z e n e ) o f p _ - F C 6 H 4 P C l 2 w e r e f o u n d t o be -7.79 ppm. i n C L C l ^ , -7.48 ppm. i n C g H 1 2 a n d -7.52 ppm. i n C 6 H 6 . The f l u o r i n e c h e m i c a l s h i f t o f m-FCgH^PHg h a s b e e n d e t e r m i n e d 9 8 t o be +0.1 ppm. r e l a t i v e t o f l u o r o b e n z e n e . No r e s o l u t i o n o f t h e s e t w o p e a k s c o u l d be o b s e r v e d i n t h e - 1 1 0 -t h r e e s o l v e n t s t e s t e d . F r o m a c o m p a r i s o n o f b o t h t h e h a l f - h e i g h t w i d t h s and t h e b a s e w i d t h s o f t h e r e s o n a n c e o b s e r v e d , t h e d i f f e r e n c e s i n c h e m i c a l s h i f t b e t w e e n m-FCgH^PR^ a n d FCgH^ c o u l d n o t h a v e e x c e e d e d 0.2 ppm. i n a n y o f t h e s o l v e n t s , a n d was p r o b a b l y l e s s t h a n o r e q u a l t o 0.1 ppm. The f l u o r i n e c h e m i c a l s h i f t s a r e t a b u l a t e d i n T a b l e I I o f t h e f o l l o w i n g s e c t i o n . MASS SPECTRA: A l l mass s p e c t r a w e r e r e c o r d e d u s i n g a M e t r o p o l i t a n V i c k e r s MS 9 mass s p e c t r o m e t e r . - VIBRATIONAL SPECTRA: A l l i n f r a r e d s p e c t r a w e r e r e c o r d e d i n t h e s o l i d s t a t e u s i n g a n u j o l m u l l . A P e r k i n - E l m e r M o d e l 457 g r a t i n g i n f r a r e d s p e c t r o p h o t o m e t e r was u s e d f o r r o u t i n e s p e c t r a ( i n t h e 4 0 0 0 - 2 5 0 cm" r e g i o n . ) The f a r - i n f r a r e d s p e c t r u m o f M e 2 P 2 S 4 was r e c o r d e d a s a n u j o l m u l l u s i n g a P e r k i n -E l m e r M o d e l 310 i n f r a r e d s p e c t r o p h o t o m e t e r . A l l Raman s p e c t r a w e r e r e c o r d e d w i t h a C a r y 81 s p e c t r o m e t e r u s i n g 6 3 2 8 A 0 e x c i t a t i o n f r o m a S p e c t r a P h y s i c s M o d e l 125 He-Ne c o n t i n u o u s g a s l a s e r . To o b t a i n a c c u r a t e d e p o l a r i z a t i o n r a t i o s , t h e i n s t r u m e n t was c a l i b -r a t e d u s i n g d e p o l a r i z a t i o n r a t i o s p r e v i o u s l y r e p o r t e d f o r v a r i o u s b a n d s o f 0 S o , C H 0 C 1 0 a n d C C l ^ . - H i -l l . RESULTS AND D I S C U S S I O N I n t h i s s e c t i o n , t h e s y s t e m a t i c c h e m i c a l r e l a t i o n -s h i p b e t w e e n t h e o r g a n i c p h o s p h o r u s - s u l p h u r compounds w i l l be p r e s e n t e d a n d t h e s t r u c t u r e s o f t h o s e compounds w h i c h a r e p r e s e n t l y u n c e r t a i n w i l l be d e t e r m i n e d . F o r one o f t h e s e compounds, P h ^ P ^ S , t h e s t r u c t u r e was d e t e r m i n e d c r y s t a l l o g r a p h i c a l l y ; f o r o t h e r c ompounds, s t r u c t u r e s w e r e d e d u c e d s p e c t r o s c o p i c a l l y . F i n a l l y , t h e t y p e s o f e l e c -t r o n i c i n t e r a c t i o n b e t w e e n t h e b a s i c s k e l e t a l s t r u c t u r e s a n d t h e i r p h e n y l s u b s t i t u e n t s w i l l be e x a m i n e d b y a n i n t e r --tq p r e t a t i o n o f t h e V F n.m.r. r e s u l t s o f t h e i r m- a n d p_-f l u o r o p h e n y l a n a l o g u e s . As a r e s u l t o f e x p e r i m e n t s o u t l i n e d i n t h e p r e v i o u s s e c t i o n , i t h a s b e e n e s t a b l i s h e d t h a t o r g a n o p h o s p h o r u s -s u l p h u r r i n g compounds p o s s e s s t h e same s t r u c t u r a l mob-i l i t y a s c a g e p h o s p h o r u s - s u l p h i d e s ; t h e i n t e r r e l a t i o n s h i p b e t w e e n members o f t h e f o r m e r g r o u p i s i l l u s t r a t e d i n F i g . 4, i n w h i c h s t a r r e d r e a c t i o n s r e p r e s e n t o r i g i n a l w o r k . The 3 F n.m.r. c h e m i c a l s h i f t s o f t h e f l u o r o p h e n y l d e r i v -a t i v e s , t o g e t h e r w i t h t h e i n d u c t i v e a n d r e s o n a n c e p a r a -m e t e r s d e d u c e d f r o m t h e m , a r e l i s t e d i n T a b l e I I . S p e c -t r o s c o p i c d a t a f o r t h e compounds P h 2 P , , I 2 , P n 3 I > 3 S 3 » P h ^ P ^ S , P h 2 P 2 S 4 a n d t h e i r f l u o r o p h e n y l d e r i v a t i v e s w i l l now be p r e s e n t e d i n d e t a i l a l o n g w i t h s i m i l a r r e s u l t s f o r t h e f l u o r o p h e n y l d e r i v a t i v e s o f ( P h P ) n . M u ch o f t h e PhPCL P h 2 P 2 I 2 S g or I* ( PhP) n<- excess PBu. Ph 2p2s4 FI6. 4= Reactions of Organophosphorus Sulphur Ring Compounds TABLE I I SHI E L D I N G PARAMETERS 6 AND TAFT INDUCTIVE AND RESONANCE PARAMETERS COMPOUND S ( m - F ) S ( p _ - F ) F C 6 H 4 P H 2 +0.1° - 0 . 6 d +0.07 +0.02 F C 6 H 4 P C 1 2 -2.8 -7.8 +0.48 +0.17 ( F C 6 H 4 P ) 4 S - 1 . 1 4 , - 1 . 3 5 - 0 . 6 0 , -0.82 +0.25, +0.27 -0 . 0 2 ( F C . H . P S ) , f - 2 . 6 5 ( 1 ) -6.9 + 0 . 4 6 ( 1 ) +0.14 b 4 3 [ - 2 . 5 1 ( 2 ) - 3 . 7 , -3.2 +0 . 4 4 ( 2 ) +0.04, +0. ( F C 6 H 4 P S 2 ) 2 -3.5 -9.4 +0.58 +0.20 ( F C 6 H 4 P I ) 2 -1.9 -6.3 +0.35 +0.15 ^ ° 6 H 4 P ) n - 1 . 6 5 , - 1 . 3 9 u n o b t a i n a b l e +0.32, +0.26 a < J I = 0 . 1 4 0 9 ( 0 . 6 - J H m " x ) b C T R o = 0 . 0 3 3 9 ( j H m " x - j H p " x ) c f r o m r e f . 9 8 , i n C F C 1 5 d f r o m r e f . 9 7 , i n b e n z e n e e p . p . m . r e l a t i v e t o i n t e r n a l f l u o r o b e n z e n e , i n C D C 1 - 1 1 4 -s p e c t r o s c o p i c w o r k p r e s e n t e d h e r e i n v o l v e s v i b r a t i o n a l a s s i g n m e n t s d e r i v e d f r o m i n f r a r e d a n d Raman s p e c t r a . The a s s i g n m e n t s w e r e made f o r t h e s i m p l e s t m o l e c u l e s f i r s t a n d w e r e t h e n e x t e n d e d t o t h e more c o m p l i c a t e d m o l e c u l e s . I n t h i s way, f r e q u e n c y r a n g e s o f v a r i o u s c h a r a c t e r i s t i c g r o u p i n g s w e r e o b t a i n e d a n d t h e v i b r a t i o n a l s p e c t r o s c o p i c w o r k c o u l d be u s e d t o c o n f i r m t h e s t r u c t u r e s o f v a r i o u s c o m pounds. Much o f t h e d i f f i c u l t y i n v o l v e d i n m a k i n g v i b r a t i o n a l a s s i g n m e n t s h a s b e e n t o e l i m i n a t e t h e i n t e r n a l v i b r a t i o n s o f t h e p h e n y l g r o u p s . T h e r e a r e n u m e r o u s l o w - f r e q u e n c y v i b r a t i o n s w h i c h a r e o f s i m i l a r e n e r g y t o t h o s e o f , f o r e x a m p l e , P=S, P-S o r P-P b o n d s . To s i m p l i f y t h e s e a s s i g n -m e n t s , t h e v i b r a t i o n a l s p e c t r a o f P h P H 2 a n d P h P C l 2 ( T a b l e V I ) w e r e e x a m i n e d . W i t h t h e a i d o f t h e s e two compounds, i t h a s b e e n p o s s i b l e t o d e t e r m i n e many o f t h e l o w e r - f r e q u e n c y p h e n y l v i b r a t i o n s . T a b l e I V l i s t s t h e h i g h e r - f r e q u e n c y i n f r a r e d v i b r a t i o n s c h a r a c t e r i s t i c o f p h e n y l a n d f l u o r o p h e n y l g r o u p s . T h e s e v i b r a t i o n s w e r e f o u n d i n v i r t u a l l y a l l t h e p h e n y l a n d f l u o r o p h e n y l d e r i v -a t i v e s o f t h e compounds e x a m i n e d ; c o n s e q u e n t l y , t h i s l i s t w i l l n o t be r e p e a t e d f o r e a c h compound d i s c u s s e d . 103 W h i f f e n h a s e x a m i n e d t h e v i b r a t i o n s o f monosub-s t i t u t e d p h e n y l g r o u p s , d e n o t e d C^H^X, a n d h a s f o u n d t h a t TABLE I V CHARACTERISTIC INFRARED FREQUENCIES OF PHENYL AND FLUOROPHENYL GROUPS PHENYL m-FLUOROPHENYL FREQUENCY ( c m - 1 ) 1 5 7 0 ( v a r . ) 1 4 3 0 ( s h a r p ) 1 2 7 0 ( s h a r p ) 1 1 8 0 ( v a r . ) 9 9 6 ( s h a r p ) 8 0 0 ( b r o a d ) 7 4 0 ( s h a r p , s ) 6 8 0 ( s ) 4 6 5 ( m - s ) ASSIGNMENT a r o m a t i c G-C s t r e t c h a r o m a t i c C-C s t r e t c h C-H i n - p l a n e b e n d C-H i n - p l a n e b e n d r i n g v i b r a t i o n C-H o u t - o f - p l a n e b e n d C-H o u t - o f - p l a n e b e n d o u t - o f - p l a n e r i n g d e f o r m a t i o n o u t - o f - p l a n e s k e l e t a l v i b r a t i o n FREQUENCY ( c m " 1 ) 1 5 9 5 ( v a r . ) 1 5 7 5 ( B ) 1 4 7 0 ( a ) 1 4 2 0 ( B ) 1 2 6 5 ( s h a r p ) 1 2 2 0 ( B ) 1 1 6 0 ( v a r . ) 1 0 9 0 ( v a r . ) 1 0 0 0 ( s h a r p ) 9 0 0 ( s h a r p ) 8 7 0 ( v s ) 7 8 0 ( v s ) 6 7 5 ( v s ) 520(ms) 440(ms) ASSIGNMENT a r o m a t i c C-C s t r e t c h a r o m a t i c C-C s t r e t c h a r o m a t i c C-C s t r e t c h a r o m a t i c C-C s t r e t c h C-H i n - p l a n e b e n d C-F s t r e t c h i n g C-H i n - p l a n e b e n d C-H i n - p l a n e b e n d r i n g v i b r a t i o n C-H o u t - o f - p l a n e b e n d C-H o u t - o f - p l a n e b e n d o u t - o f - p l a n e r i n g d e f o r m a t i o n o u t - o f - p l a n e s k e l e t a l v i b r a t i o n o u t - o f - p l a n e s k e l e t a l v i b r a t i o n v a r . = v a r i a b l e ; v = v e r y ; m=medium; s = s t r o n g ; w=weak ( c o n t i n u e d o v e r l e a f ) FREQUENCY (cm"1) 1580(s) 1490(a) 1390(m) 1298(m) 1240(vs) 1 1 6 5 ( v s ) 1080,1090(m) 1020(w) 820(vs) 510(ms) 405(w) TABLE IY(cont . ) p-FLUOROPHENYL ASSIGNMENT aromatic C-C stretch aromatic C-C stretch C-H in-plane bend C-F stretching C-H in-plane bend C-H in-plane bend C-H in-plane bend C-H out-of-plane bend out-of-plane skeletal vibration out-of-plane skeletal vibration - 1 1 8 -t h e r e a r e s i x v i b r a t i o n a l modes i n w h i c h t h e s u b s t i t u e n t X moves w i t h a p p r e c i a b l e a m p l i t u d e a n d c o n s e q u e n t l y , t h e s e f r e q u e n c i e s a r e s e n s i t i v e t o t h e mass o f X ( S e e P i g . 5.) O f t h e s e s i x X - s e n s i t i v e v i b r a t i o n s , t h r e e b e l o n g t o t h e t o t a l l y s y m m e t r i c c l a s s a n d w i l l g i v e r i s e t o p o l a r -i z e d Raman l i n e s ; W h i f f e n d e n o t e s t h e s e v i b r a t i o n s a s X - s e n s . ( q ) , X - s e n s . ( r ) a n d X - s e n s . ( t ) . A l l t h e s e modes i n v o l v e some d e g r e e o f C-X s t r e t c h i n g , a n d i t i s t h e r e f o r e n o t j u s t i f i a b l e t o c o n s i d e r a n y o f t h e s e v i b r a t i o n s a s " t h e " C-X s t r e t c h i n g f r e q u e n c y . The f o u r t h s u b s t i t u e n t -s e n s i t i v e v i b r a t i o n , X - s e n s . ( u ) , b e l o n g s t o t h e B 1 c l a s s a n d may be c a l l e d t h e C-X i n - p l a n e d e f o r m a t i o n mode. The r e m a i n i n g f r e q u e n c i e s , d e n o t e d X - s e n s . ( x ) a n d X - s e n s . ( y ) , b e l o n g t o t h e B 2 c l a s s a n d may b e c o n s i d e r e d a s o u t - o f -p l a n e d e f o r m a t i o n modes. S i n c e t h e s e X - s e n s i t i v e v i b r a t i o n s i n v o l v e c o n s i d e r a b l e m o t i o n o f t h e s u b s t i t u e n t a t o m , i t i s r e a s o n a b l e t o assume t h a t a t l e a s t some o f t h e s e v i b r a t i o n s m i g h t be a f u n c t i o n n o t o n l y o f X, b u t a l s o o f a n y a d d i t i o n a l g r o u p s a t t a c h e d t o X. To t e s t t h i s h y p o t h e s i s , t h e Raman s p e c t r a o f P h P H 2 a n d P h P C l 2 w e r e a n a l y z e d . The v i b r a t i o n a l a s s i g n -i n g m e n t s o f PhPR" 2, a s r e p o r t e d b y A m s t e r a n d C o l t h u p , a r e i n c o m p l e t e a g r e e m e n t w i t h t h e w o r k o f W h i f f e n ; i n f a c t , t h e p h e n y l f r e q u e n c i e s a r e e a s y t o a s s i g n a s t h e y a r e v e r y c l o s e t o t h o s e r e p o r t e d f o r c h l o r o b e n z e n e , no d o u b t b e c a u s e o f t h e s i m i l a r m a s s e s o f t h e c h l o r i n e a t o m a n d t h e PH„ - 1 1 9 -g r o u p . P h P C l 2 i s i n a d e q u a t e l y d e s c r i b e d i n t h e l i t e r a t u r e w i t h r e s p e c t t o p o l a r i z a t i o n m e a s u r e m e n t s ; t h e r e f o r e , t h e s e d a t a w e r e o b t a i n e d a n d a r e p r e s e n t e d i n T a b l e V I . O t h e r w o r k e r s h a v e e x a m i n e d t h e i n f r a r e d a n d Raman s p e c t r a o f P h P C l 2 b u t t h e i r a s s i g n m e n t s h a v e s u f f e r e d f r o m a n 106 a b s e n c e o f p o l a r i z a t i o n d a t a ; f o r e x a m p l e , G o u b e a u e t a l . _ -) a s s i g n e d t h e a p p a r e n t l y p o l a r i z e d b a n d a t 455 cm a s a s y m m e t r i c P C 1 2 s t r e t c h i n g . The s t r o n g e s t p e a k s i n t h e Raman s p e c t r u m o f P h P G l 2 a r e a s s i g n e d t o v a r i o u s P - C l modes. The v e r y s t r o n g a b s o r p t i o n a t 504 c m - 1 i s o b v i o u s l y 108 due t o s y m m e t r i c P C 1 2 s t r e t c h i n g . G r e e n a n d K y n a s t o n a s s i g n e d t h e s t r o n g d e p o l a r i z e d b a n d a t 293 cm a s P C 1 2 w a g g i n g ; t h e same w o r k e r s c o n s i d e r e d t h e d e p o l a r i z e d b a n d a t 190 cm t o be a P G 1 2 s c i s s o r v i b r a t i o n . S u c h a v i b -r a t i o n w o u l d be e x p e c t e d t o g i v e r i s e t o a p o l a r i z e d b a n d , h o w e v e r , a n d t h i s v i b r a t i o n i s t h e r e f o r e more l i k e l y t o be a P C 1 2 r o c k i n g v i b r a t i o n . F r a n k i s s a n d M i l l e r 1 0 9 h a v e e x a m i n e d t h e v i b r a t i o n a l s p e c t r a o f I ^ C l ^ and h a v e a s s i g n e d a d e p o l a r i z e d b a n d a t 189 cm a s a P C 1 2 r o c k i n g v i b r a t i o n . H a v i n g c o r r e c t e d a n d e l i m i n a t e d P C 1 2 v i b r a -t i o n a l modes, t h e r e m a i n i n g v i b r a t i o n s c a n be c o n s i d e r e d t o be due t o t h e p h e n y l g r o u p . By c o m p a r i s o n w i t h t h e s p e c t r u m o f P h P H 2 , s e v e r a l o b v i o u s a s s i g n m e n t s c a n be made. .The b a n d a t 619 cm""1 i n P h P C l 2 , a n d t h a t a t 622 cm""1 i n P h P H 2 , i s o b v i o u s l y W h i f f e n ' s v i b r a t i o n ( s ) , a C-C-C i n -p l a n e r i n g d e f o r m a t i o n ( w h i c h i s n o t s u b s t i t u e n t - s e n s i t i v e . ) The p o l a r i z e d b a n d a t 693 cm i n P h P H 2 c o r r e l a t e s w i t h TABLE V I RAMAN SPECTRAL RESULTS ( m - F C 6 H 4 P I ) 2 i n C S 2 n e a t m-FCgH^PHg FREQUENCY ( c m " 1 ) P FREQUENCY ( c m " 1 ) R E L A T I V E I N T E N S I T Y P ASSIGNMENT 675 n o t m e a s u r e d 680 10 0 . 1 8 ( p ) P - s e n s . ( r ) 567 0 . 6 5 ( d p ) 539 1.2 0 . 6 9 ( d p ) 523 0 . 3 8 ( p ? ) 523 4.3 0 . 3 l ( p ? ) F - s e n s . ( t ) 486 0 . 3 5 ( p ? ) 433 0.8 ~ 0 . 3 ( p ? ? ) s e e t e x t 431 0 . 3 5 ( p ? ) 384 10 0 . 1 8 ( p ) P - s e n s . ( t ) 343 0 . 2 8 ( p ) 245 4.2 0 . 7 5 ( d p ) F - s e n s . ( x ) 245 0 . 7 7 ( d p ) 217 1.2 0 . 6 3 ( d p ? ) 201 0 . 2 4 ( p ) 179 3.2 0 . 8 2 ( d p ) P - s e n s . ( x ) 178 0 . 2 0 ( p ) P = d e p o l a r i z a t i o n r a t i o ; p = p o l a r i z e d ; dp = d e p o l a r i z e d ( c o n t i n u e d o v e r l e a f ) i H O I - 1 2 1 -TABLE V I ( c o n t . )  RAMAN SPECTRAL RESULTS n e a t P h P H 2 a FREQUENCY R E L A T I V E ASSIGNMENT ( c m " 1 ) I N T E N S I T Y ' 693 6 ( p ) X - s e n s . ( r ) 622 4 ( d p ) vib.(s) 438 2 ( d p ) X - s e n s . ( y ) 3 9 4 8 ( p ) X - s e n s . ( t ) 2 5 5 2 ( d p ) X - s e n s . ( u ) 179 6 ( d P ) X - s e n s . ( x ) FREQUENCY ( c m " 1 ) R E L A T I V E I N T E N S I T Y n e a t P h P C l 2 P ASSIGNMENT 7 0 1 619 504 455 423 293 256 244 190 ( 4 ) ( 1 ) weak weak n o t m e a s u r e d n o t m e a s u r e d 0 . 1 8 ( p ) 0 . 3 0 ( p ) 0 . 7 0 ( d p ) 0 . 7 8 ( d p ) 0 . 7 0 ( d p ) X - s e n s . ( r ) v i b . ( s ) sym. P C 1 2 s t r e t c h s e e t e x t s e e t e x t P C 1 2 wag s e e t e x t s e e t e x t s e e t e x t a . f r o m A m s t e r and C o l t h u p , r e f . 104 b. a s s i g n m e n t b a s e d i n p a r t o n w o r k o f G r e e n and K y n a s t o n , r e f . 108 - 1 2 2 -_ i t h e 7 0 1 cm b a n d i n P h P C l 2 ; "by c o m p a r i s o n w i t h W h i f f e n ' s w o r k o n m o n o s u b s t i t u t e d h a l o b e n z e n e s , t h e s e b a n d s a r e a t t r i b u t e d t o t h e t o t a l l y s y m m e t r i c X - s e n s . ( r ) v i b r a t i o n . The X - s e n s . ( u ) v i b r a t i o n o c c u r s a t 255 cm i n P h P H 2 . Two b a n d s o c c u r i n t h i s r e g i o n i n t h e s p e c t r u m o f — 1 —1 P h P C l 2 , one a t 244 cm a n d one a t 256 cm . G r e e n a n d 108 K y n a s t o n h a v e a s s i g n e d t h e s e b a n d s a s t h e X - s e n s . ( u ) v i b r a t i o n a n d P C 1 2 t w i s t i n g r e s p e c t i v e l y . B o t h t h e s e v i b -r a t i o n s w o u l d be e x p e c t e d t o g i v e r i s e t o d e p o l a r i z e d b a n d s s o t h e r e i s l i t t l e c h a n c e o f d i s t i n g u i s h i n g b e t w e e n t h e m . The d e p o l a r i z e d b a n d a t 179 cm i n PhPH" 2 i s c o n -s i d e r e d t o be t h e X - s e n s . ( x ) v i b r a t i o n . T h i s b a n d c o u l d n o t be l o c a t e d i n t h e Raman s p e c t r u m o f P h P C l 2 ; i t may p o s s i b l y be o b s c u r e d b y t h e s t r o n g P 0 1 2 r o c k i n g v i b r a t i o n — 1 a t 1 9 0 cm . F i n a l l y , t h e r e r e m a i n two b a n d s i n e a c h . s p e c t r u m : i n P h P H 2 , t h e s e b a n d s o c c u r a t 394 cm ( p , i n t e n s i t y 8) a n d 438 cm ( d p , i n t e n s i t y 2) a n d A m s t e r a n d C o l t h u p 1 ^ 4 h a v e a s s i g n e d t h e s e b a n d s a s t h e X - s e n s . ( t ) a nd X - s e n s . ( y ) v i b r a t i o n s r e s p e c t i v e l y , i n a g r e e m e n t w i t h 103 W h i f f e n J who h a s shown t h a t t h e y a r e A^ and B 2 v i b r a t i o n s r e s p e c t i v e l y . I n P h P C l 2 , s i m i l a r b a n d s a r e s e e n a t 423 cm" 1 ( p = 0.70, i n t e n s i t y 1) a n d 455 cm" 1 (p = 0.30, i n t e n s i t y 4) a n d a r e c o n s i d e r e d t o be t h e X - s e n s . ( y ) a n d 108 X - s e n s . ( t ) v i b r a t i o n s r e s p e c t i v e l y ; G r e e n and K y n a s t o n h a v e i n c o r r e c t l y r e v e r s e d t h e s e two a s s i g n m e n t s i n t h e i r w o r k on P h P 0 1 2 . - 1 2 3 -The Diiododiphenyldiphosphines ( R 2 P 2 I 2 ) For the sake of c o n t i n u i t y w i t h r e spect to d i s c u s s i o n of the v i b r a t i o n a l work, the s t r u c t u r a l l y simple d i i o d o -d iphenyldiphosphine, P h 2 P 2 I 2 , w i l l be considered f i r s t . The d i m e r i c nature of t h i s compound i s confirmed by i t s mass spectrum (Table I I I ) , i n which a weak parent i o n i s seen. The major fragment o f the spectrum i s P h P I + , i n d i -c a t i n g t h a t the P-P bond i s cleaved r a t h e r e a s i l y . S i g -n i f i c a n t rearrangement has o b v i o u s l y occurred i n order to y i e l d s p e c ies such as P h ^ P ^ , P h 5 P 5 + and P h 5 P + . I t i s apparent t h a t P h 2 P 2 I 2 can regenerate the c y c l o p o l y -phosphine Ph^P^ v i a e l i m i n a t i o n of i o d i n e . The same re a c -t i o n was observed to occur when P h 2 P 2 I 2 was l e f t i n s o l u -31 t i o n f o r a l o n g p e r i o d o f time; a P n.m.r. spectrum of a p a r t l y decomposed sample of (m-FCgH^PI),, showed the presence of (m-FCgH 4P) n. The most l i k e l y e x p l a n a t i o n f o r the appearance of the Ph^P^"1" peak i s t h a t P h 2 P 2 I 2 can a s s o c i a t e i n the vapour phase, as evidence has been p r e -110 sented to show t h a t symmetrical diphosphines can a s s o c i -ate i n s o l u t i o n . The l o s s of molecular i o d i n e i s remin-i s c e n t of the behaviour of C l - P ^ S ^ ^ which has been shown to r e v e r t to P^S^ even under v e r y m i l d c o n d i t i o n s . The peak Ph^P"1" i s no doubt d e r i v e d from Ph^P^*; the r e p o r t e d 1 1 1 base peak i n the mass spectrum of Ph^P^ i s Ph^P*. The very i n t e n s e peak at m/e 183 appears i n most of the mass s p e c t r a r e p o r t e d here and i s assigned s t r u c t u r e I . TABLE I I I MASS SPECTRA OP P h 2 P 2 I 2 AND (jD-FCgH^PI) 2 P e a k ( m / e ) A b u n d a n c e A s s i g n m e n t / + ^  P e a k ( m / e ) A b u n d a n c e A s s i g n m e n t ^ + ^ 470 1.1 P h 2 P 2 I 2 506 37.8 ( F C 6 H 4 P I ) 2 432 10.2 P h 4 P 4 379 100 ( P C 6 H 4 P ) 2 I 362 11.4 P h P I 2 316 54.0 ( F C 6 H 4 ) 3 P 343 44.9 P h 2 P 2 I 284 8.9 ( F C 6 H 4 ) P 2 I 324 6.8 P h 3 P 3 253 81.6 P C 6 H 4 P I 262 10.7 P h 3 P 221 53.4 ( F C 6 H 4 ) 2 P 235 100 P h P I 219 47.5 ., ( F C 6 H 3 ) 2 P 216 9.8 P h 2 P 2 201 25.8 ( F C 6 H 3 ) P ( C 6 H 4 ) 185 9.7 P h 2 P 157 48.6 F C 6 H 4 P 2 183 43.4 ( C 6 H 4 ) 2 P 139 6.2 P h P 2 138 1 2 . 1 G 6 H 4 P 2 108 73.6 P h P 107 82.8 C 6 H 4 P 77 41.2 P h •125-P + II III + P S i m i l a r l y , t h e m a s s s p e c t r u m o f ( 2 - F C g H 4 P I ) 2 e x h i b i t s p e a k s a t m/e 219 a n d 201 w h i c h a r e a s s i g n e d s t r u c t u r e s I I a n d I I I r e s p e c t i v e l y . T h e s e t h r e e i o n s a r e m o s t l i k e l y s t a b i l i z e d b y t h e a r o m a t i c c h a r a c t e r o f t h e 1 4 - e l e c t r o n s y s t e m t h a t r e s u l t s i f p h o s p h o r u s d o n a t e s i t s r e m a i n i n g l o n e p a i r t o t h e 77*-system. The f a c t t h a t t h e s e m o l e c u l a r i o n s o c c u r s o f r e q u e n t l y , a n d i n g e n e r a l l y l a r g e a b u n d a n c e , c o n f i r m s t h a t t h e y m u s t p o s s e s s s p e c i a l s t a b i l i t y . E v e n t h o u g h t h e r e a r e s e v e r a l f r a g m e n t s o f h i g h i n t e n s i t y i n w h i c h i t i s a p p a r e n t t h a t t h e r e a r e t w o p h e n y l g r o u p s a t t a c h e d t o a p h o s p h o r u s a t o m , one o f t h e s e p h e n y l g r o u p s m u s t h a v e m i g r a t e d f r o m e l s e w h e r e d u r i n g m o l e c u l a r r e -- 1 2 6 -i a r r a n g e m e n t . The J P n.m.r. s p e c t r u m o f ( j J - F C g H ^ P I ) 2 e x h i b i t s a s i n g l e p e a k a t +21.8 p.p.m. ( e x t . P^Og) c o n -f i r m i n g t h a t o n l y one t y p e o f p h o s p h o r u s e n v i r o n m e n t i s p r e s e n t a n d t h a t t h i s compound i s 1 , 2 - d i i o d o - l , 2 - d i ( p _ -f l u o r o p h e n y l ) d i p h o s p h i n e . The l o w f r e q u e n c y i n f r a r e d v i b r a t i o n s o f P h 2 P 2 I 2 , ( m - F C 6 H 4 P I ) 2 a n d (jD-FCgH^PI) 2 a r e l i s t e d i n T a b l e V t o -g e t h e r w i t h t h e l o w - f r e q u e n c y R a m a n - a c t i v e v i b r a t i o n s . The Raman s p e c t r u m o f ( m - F C g H ^ P I ) 2 i n c a r b o n d i s u l p h i d e , a n d t h a t o f l i q u i d m-FCgH^PR^, a r e r e p o r t e d i n T a b l e V I , t o g e t h e r w i t h t h e d e g r e e o f p o l a r i z a t i o n o f e a c h v i b r a t i o n . C o n s i d e r f i r s t t h e Raman s p e c t r u m o f P h 2 P 2 I 2 < The _ -i e x t r e m e l y s t r o n g b a n d a t 337 cm i s due t o s y m m e t r i c s t r e t c h i n g o f t h e h i g h l y p o l a r i z a b l e P - I b o n d ; a c c o r d i n g 112 t o C o r b r i d g e , P - I s t r e t c h i n g w o u l d be e x p e c t e d t o be — 1 —1 f o u n d i n t h i s r e g i o n . The b a n d s a t 457 cm and 426 cm i n P h 2 P 2 I 2 a r e c o n s i d e r e d t o be t h e X - s e n s . ( t ) a n d X - s e n s . ( y ) v i b r a t i o n s , r e s p e c t i v e l y , b y a n a l o g y t o s i m i l a r b a n d s — 1 — 1 a t 455 cm a n d 423 cm i n P h P C l 2 . I t may be a r g u e d t h a t t h e s e v i b r a t i o n s s h o u l d s h i f t b y a l a r g e r f r e q u e n c y u p o n r e p l a c e m e n t o f c h l o r i n e b y i o d i n e ; h o w e v e r , t h e w o r k o f W h i f f e n h a s shown t h a t a l e v e l l i n g e f f e c t o c c u r s i n t h e X - s e n s i t i v e v i b r a t i o n s a s t h e mass o f X i s i n c r e a s e d . F u r t h e r m o r e , t h e p r i m a r y e f f e c t i s due t o t h e p h o s p h o r u s a t o m a nd t h e s e c o n d a r y e f f e c t o f t h e p h o s p h o r u s s u b s t i -TABLE V LOW FREQUENCY INFRARED AND RAMAN ABSORPTION INFRARED ABSORPTION (cm"" 1) RAMAN ABSORPTION ( c m " 1 ) ( P h 9 P , I J FREQUENCY R E L A T I V E ASSIGNMENT P h 2 P 2 I 2 ASSIGNMENT ( c m " 1 ) IN T E N S I T Y 3 9 8 , 3 8 8 s e e t e x t 618 0.07 v i b . ( s ) 3 4 1 ( a ) ^ a s . ^ " 1 ) 504 0.9 V ( P - P ) 258(mw) 457 0.5 P - s e n s . ( t ) 426 0.4 P - s e n s . ( y ) 404 0.04 v i b . ( w ) ( £ - F C 6 H 4 P I ) 2 ASSIGNMENT 337 10 l ^ ( P - I ) 228 2.3 363(m) ^ a s . ^ " 1 ) 202 3.4 ' 3 5 1 140 0.7 ( m - F C 6 H 4 P I ) 2 ASSIGNMENT 5 5 0 ( v w ) 3 8 8 ( s ) 3 3 4 ( s ) s e e t e x t v = v e r y w=weak m=medium s = s t r o n g s . = s y m m e t r i c a s . = a n t i s y m m e t r i c ( c o n t i n u e d o v e r l e a f ) TABLE V ( c o n t . ) LOW FREQUENCY RAMAN ABSORPTION ( £ - F C 6 H 4 P I ) 2 ( m - F C 6 H 4 P I ) 2 FREQUENCY R E L A T I V E ASSIGNMENT FREQUENCY R E L A T I V E ASSIGNMENT ( c m " 1 ) I N T E N S I T Y ( c m - 1 ) I N T E N S I T Y 6 3 2 , 6 2 2 0.6 v i b . ( s ) 525 0.7 F - s e n s . ( t ) 478 5.4 V(P-P) 424 1.0 P - s e n s . ( t ) 414 0.1 P - s e n s . ( y ) o r v i b . ( w ) 387 2.2 s e e t e x t 366 10 318 2.7 s e e t e x t 206 6.9 17 1 0.1 157 0.1 675 0.3 P - s e n s . ( r ) 569 0.3 s e e t e x t 522 0.1 F - s e n s . ( t ) 489 1.0 I V ( P - P ) 431 1.3 P - s e n s . ( t ) 410 0.2 P - s e n s . ( y ) o r v i b . 340 10 Va ( P - I ) s. 245 0.1' F - s e n s . ( x ) 203 0.7 178 4.7 136 0.7 - 1 2 9 -t u e n t s w o u l d b e e x p e c t e d t o b e m u c h l e s s i n r e p l a c i n g o n e c h l o r i n e a t o m b y i o d i n e ( a s s u m i n g t h e o t h e r s u b s t i t u e n t , p h o s p h o r u s , t o h a v e a p p r o x i m a t e l y t h e s a m e m a s s e f f e c t a s t h e c h l o r i n e w h i c h i t r e p l a c e s ) t h a n i t w a s i n r e p l a c i n g t w o h y d r o g e n a t o m s b y t w o c h l o r i n e a t o m s . I n a n y c a s e , t h e o n l y o t h e r v i b r a t i o n o f m o d e r a t e i n t e n s i t y i n t h i s r e g i o n o c c u r s a t 5 0 4 cm a n d i t d o e s n o t s e e m p l a u s i b l e t h a t s u c h a f u r t h e r l a r g e f r e q u e n c y s h i f t c o u l d o c c u r f o r e i t h e r t h e X - s e n s . ( t ) o r t h e X - s e n s . ( y ) v i b r a t i o n . B y p r o c e s s o f e l i m i n a t i o n , t h i s b a n d a t 5 0 4 c m " " 1 i s c o n -112 s i d e r e d t o b e d u e t o P - P s t r e t c h i n g ; C o r b r i d g e s u g g e s t s t h a t t h e t y p i c a l r a n g e o f P - P s t r e t c h i n g f r e q u e n c i e s e x t e n d s f r o m 3 9 0 t o 5 1 0 c m - 1 . R e p o r t e d P - P s t r e t c h i n g f r e q u e n c i e s i n c l u d e 4 3 7 cm f o r ? 2 H 4 * 4-45 c m " i n M e 4 P 2 S 2 1 1 4 , 5 1 0 c m " " 1 i n ( n - C 4 H g ) 4 P 2 S 2 1 1 4 , a n d 6 0 6 a n d 4 6 5 cm i n P 4 . T h e , v e r y w e a k a b s o r p t i o n a t 4 0 4 . cm*" m a y b e d u e t o W h i f f e n ' s v i b r a t i o n ( w ) , a n o u t - o f - p l a n e A 2 r i n g d e f o r m a t i o n ; t h e w e a k a b s o r p t i o n a t 6 1 8 cm i s c e r t -a i n l y W h i f f e n ' s v i b r a t i o n ( s ) , a C - C - C i n - p l a n e r i n g d e -f o r m a t i o n . T h e r e m a i n i n g l o w - f r e q u e n c y R a m a n v i b r a t i o n s a t 2 2 8 , 2 0 2 a n d 1 4 0 cm a r e v i e w e d a s d e f o r m a t i o n m o d e s a n d h a v e n o t b e e n a s s i g n e d d e f i n i t i v e m o t i o n s . T h r e e l o w - f r e q u e n c y i n f r a r e d b a n d s ( T a b l e V) r e m a i n -1 t o b e a s s i g n e d . T h e s p l i t b a n d a t 3 9 8 , 3 8 8 cm a p p a r -116 e n t l y a l s o o c c u r s i n t h e i n f r a r e d s p e c t r u m o f P h 2 P 2 B r 2 , i n d i c a t i n g t h a t i t i s n o t h a l o g e n - d e p e n d e n t ; h o w e v e r , t h e - 1 3 0 -v i b r a t i o n t h a t c a u s e s t h i s a b s o r p t i o n h a s n o t b e e n d e d u c e d a n d n e i t h e r h a s t h a t w h i c h c a u s e s weak a b s o r p t i o n a t 258 — 1 -1 cm . The s t r o n g b a n d a t 341 cm i s c o n s i d e r e d t o be d u e t o P - I s t r e t c h i n g . I f t h i s v i b r a t i o n i s c o n s i d e r e d t o be a n a n t i s y m m e t r i c P - I s t r e t c h , t h e n t h e o n l y i n f r a r e d a n d Raman c o i n c i d e n t b a n d ( t o 250 c m - 1 ) i s t h e X - s e n s . ( t ) p h e n y l v i b r a t i o n , i m p l y i n g t h a t P h 2 P 2 I 2 h a s a c e n t r e o f s y m m e t r y . The s t r u c t u r e o f P h 2 P 2 I 2 i n t h e s o l i d s t a t e i s t h e r e f o r e b e l i e v e d t o be a s i l l u s t r a t e d b e l o w . ...-P-i I • ^ C 6 H 5 A n y o t h e r c o n f o r m a t i o n o f P h 2 P 2 I 2 , o r a c h a n g e i n c o n f i g -u r a t i o n a t p h o s p h o r u s , w o u l d r e s u l t i n s p e c i e s w h o s e m o l e -c u l a r s y m m e t r y w o u l d p e r m i t c o m p l e t e c o i n c i d e n c e o f i n f r a r e d a n d Raman f u n d a m e n t a l s . The Raman s p e c t r a o f m-FCgH^PHg a n d o f ( m - F C g H ^ P I ^ i n s o l u t i o n a r e r e p o r t e d i n T a b l e V I . I n m e t a - d i s u b s t i t u t e d b e n z e n e s , t h e l o c a l s y m m e t r y o f t h e r i n g i s l o w e r e d t o 0 ; c o n s e q u e n t l y , a l l i n - p l a n e d e f o r m a t i o n s w i l l be t o t a l l y s y m m e t r i c a n d w i l l g i v e r i s e t o p o l a r i z e d Raman l i n e s . C o n v e r s e l y , a l l o u t - o f - p l a n e d e f o r m a t i o n s w i l l be a s y m -- 1 3 1 -m e t r i c a n d w i l l g i v e r i s e t o d e p o l a r i z e d Raman l i n e s . The e f f e c t o f v a r i o u s s u b s t i t u t i o n p a t t e r n s o n t h e v i b -r a t i o n s o f a b e n z e n e r i n g i s a c o m p l e x p r o b l e m a n d h a s b e e n 117 t h e s u b j e c t o f a n e x h a u s t i v e b o o k . The v i b r a t i o n a l a s s i g n m e n t s o f m-FCgH^PH,, a n d o f ( m - F C g H 4 P I ) 2 a r e t h e r e -f o r e l e s s c o m p l e t e t h a n t h o s e o f t h e i r p h e n y l a n a l o g u e s . S i n c e t h e r e a r e now two t y p e s o f X - s u b s t i t u e n t s , t h e f l u o r i n e - s e n s i t i v e v i b r a t i o n s w i l l be d e n o t e d P - s e n s . a n d t h e p h o s p h o r u s - s e n s i t i v e v i b r a t i o n s w i l l be d e n o t e d P - s e n s . The s t r o n g p o l a r i z e d b a n d a t 680 cm i s a s s i g n e d t o t h e — 1 t o t a l l y s y m m e t r i c P - s e n s . ( r ) v i b r a t i o n s e e n a t 693 cm i n PhPHg. The 680 cm b a n d c a n n o t c o r r e l a t e w i t h t h e s t r o n g i n f r a r e d b a n d s e e n a t 675 cm i n m - f l u o r o p h e n y l d e r i v a t i v e s ( T a b l e I ? ) , a s t h i s v i b r a t i o n i s a n o u t - o f -p l a n e r i n g d e f o r m a t i o n a n d c o u l d n o t g i v e r i s e t o a p o l a -— 1 r i z e d Raman l i n e . The 680 cm b a n d i n m-FCgH^PH,, i s c o n -s i d e r e d t o c o r r e l a t e w i t h t h e 675 cm b a n d o f ( m - F C g H ^ P I ) 2 > a l t h o u g h b y a n o v e r s i g h t t h e s t a t e o f p o l a -r i z a t i o n o f t h e l a t t e r v i b r a t i o n was n o t m e a s u r e d . The d e p o l a r i z e d b a n d a t 539 cm i n m-FCgH^PH,, a p p e a r s t o c o r r e l a t e w i t h t h e d e p o l a r i z e d b a n d a t 567 cm""1 i n ( m - F C g H ^ P I ) 2 . B o t h compounds h a v e a p p a r e n t l y p o l a r i z e d _ i b a n d s a t 523 cm w h i c h a r e a s s i g n e d a s t h e s y m m e t r i c F - s e n s . ( t ) v i b r a t i o n ; t h i s v i b r a t i o n o c c u r s a t 519 cm i n 103 f l u o r o b e n z e n e . The e x t r e m e l y s t r o n g p o l a r i z e d b a n d a t — 1 343 cm i s u n d o u b t e d l y t h e s y m m e t r i c P - I s t r e t c h . T he _ i s t r o n g p o l a r i z e d b a n d a t 384 cm i n m-FC^H^PH,, i s c o n -- 1 3 2 -s i d e r e d t o be t h e P - s e n s . ( t ) v i b r a t i o n s e e n a t 394 cm i n P h P H g . T h i s v i b r a t i o n was o b s e r v e d t o i n c r e a s e t o 455 c m - 1 i n P h P C l 2 ; t h e r e f o r e , t h e s t r o n g p o l a r i z e d b a n d a t 4 3 1 cm" i n ( m - F C g H ^ P I ) 2 i s c o n s i d e r e d t o be t h e P - s e n s . ( t ) v i b r a t i o n . I t i s f e l t t h a t t h i s b a n d c a n n o t c o r r e l a t e w i t h t h e v e r y weak 433 cm b a n d i n m-FCgH^PH,, b e c a u s e t h e r e l a t i v e i n t e n s i t i e s a r e v e r y d i f f e r e n t ; a l t h o u g h _ i T a b l e V I l i s t s t h i s 433 cm b a n d a s b e i n g p e r h a p s p o l a -r i z e d , t h e v i b r a t i o n i s s o weak t h a t t h e s t a t e o f p o l a -r i z a t i o n m u s t be c o n s i d e r e d t o b e u n c e r t a i n . I n f a c t , t h i s v i b r a t i o n may be t h e P - s e n s . ( y ) v i b r a t i o n s e e n a t 438 cm i n PhPR" 2. S i n c e t h e f r e q u e n c y o f t h i s v i b r a t i o n d i d n o t c h a n g e much i n p a s s i n g f r o m P h P H 2 t o P h 2 P 2 I 2 , t h e n i t i s l i k e l y t h a t t h i s b a n d i s e i t h e r n o t s e e n i n (m-FCgH^PI),, o r i s o b s c u r e d by t h e P - s e n s . ( t ) v i b r a t i o n . B y p r o c e s s o f e l i m i n a t i o n , t h e s y m m e t r i c P-P s t r e t c h i s a s s i g n e d t o t h e 486 cm""1 a b s o r p t i o n , i n g o o d a g r e e m e n t w i t h t h e P-P s t r e t c h i n g f r e q u e n c y f o u n d i n P h 2 P 2 I 2 . The d e p o l a r i z e d b a n d a t 245 cm i n m-FCgH^PH,^ c a n n o t c o r r e -l a t e w i t h t h e P - s e n s . ( u ) v i b r a t i o n s e e n a t 255 cm i n PhPH" 2, a s t h e l a t t e r v i b r a t i o n i n v o l v e s a n i n - p l a n e d e -f o r m a t i o n w h i c h w o u l d g i v e r i s e t o a p o l a r i z e d v i b r a t i o n u n d e r t h e G s y m m e t r y o f a m e t a - d i s u b s t i t u t e d b e n z e n e r i n g . The b a n d s a t 245 cm""1 i n b o t h m-FCgH^PHg and ( m - F G 6 H 4 P I ) 2 a r e t h e r e f o r e a t t r i b u t e d t o t h e F - s e n s . ( x ) v i b r a t i o n , a n o u t - o f - p l a n e C-F d e f o r m a t i o n ; t h e F - s e n s . ( x ) v i b r a t i o n o f f l u o r o b e n z e n e o c c u r s a t 242 cm""1 a c c o r d i n g t o W h i f f e n 1 0 5 . - 1 3 3 -The d e p o l a r i z e d b a n d a t 179 cm i n m-FCgH^PH,, i s m o s t l i k e l y due t o t h e P - s e n s . ( x ) v i b r a t i o n s e e n a t 179 cm i n P h P H 2 . I n c o n t r a s t , t h e a b s o r p t i o n a t 178 cm i n ( m - F C g R " 4 P I ) 2 i s due t o a s t r o n g l y p o l a r i z e d v i b r a t i o n w h i c h i s v e r y much g r e a t e r i n i n t e n s i t y t h a n t h e 179 cm b a n d i n m-FCgH^PH,,. ( C o m p a r e , f o r e x a m p l e , t h e r e l a t i v e i n t e n s i t i e s o f t h e s e b a n d s w i t h r e s p e c t t o t h e F - s e n s . ( x ) _ A v i b r a t i o n s a t 245 cm i n e a c h o f t h e s e compounds.) The _ i d e p o l a r i z e d v i b r a t i o n a t 217 cm i n m-FCgH^PH,, and t h e p o l a r i z e d b a n d a t 201 cm" i n (m-FCgH^PI),, h a v e n o t b e e n a s s i g n e d d e f i n i t i v e m o t i o n s . F i n a l l y , t h e i n f r a r e d - a c t i v e A v i b r a t i o n o b s e r v e d a t 388 cm ( T a b l e V) i s b e l i e v e d t o be t h e same v i b r a t i o n o b s e r v e d a t 3 8 8 , 398 cm i n P h 2 P 2 I 2 ; no s u c h b a n d i s o b s e r v e d i n t h e i n f r a r e d s p e c t r u m o f (jD-FCgH^PI) 2 , s u g g e s t i n g t h a t t h e v i b r a t i o n i s d e p e n d e n t u p o n t h e s u b s t i t u t i o n p a t t e r n o f t h e b e n z e n e r i n g . The s t r o n g b a n d a t 334 cm i s c o n s i d e r e d t o be due t o asym-m e t r i c P - I s t r e t c h i n g . A g a i n t h e l a c k o f c o i n c i d e n t i n f r a r e d a n d Raman f r e q u e n c i e s s u g g e s t s t h a t (m-FCgH^PI),, h a s m o l e c u l a r s y m m e t r y C^. A c o m p a r i s o n o f t h e Raman s p e c t r a o f (m-FCgH^PI),, i n s o l i d s t a t e a n d i n s o l u t i o n i l l u s t r a t e s t h a t no g r o s s s t r u c t u r a l c h a n g e s h a v e o c c u r r e d u p o n d i s s o l u t i o n a n d t h a t t h e c o n f o r m a t i o n o f t h e m o l e c u l e i s e s s e n t i a l l y t h e same i n s o l u t i o n a s i n t h e c r y s t a l . The b u l k y i o d i n e a n d p h e n y l s u b s t i t u e n t s no d o u b t h i n d e r r o t a t i o n a b o u t t h e P-P b o n d . -134-The v i b r a t i o n a l s p e c t r a o f ( j D - F C g H ^ P I ) ^ a r e more d i f f -i c u l t t o i n t e r p r e t s i n c e no jj-FCgH^PH,, was a v a i l a b l e f o r c o m p a r i s o n p u r p o s e s . H o w e v e r , s e v e r a l a s s i g n m e n t s h a v e b e e n made b y c o m p a r i s o n w i t h P h 2 P 2 I 2 a n d ( S " F C 6 H 4 P I ) 2 . The s p l i t Raman b a n d a t 622, 632 cm i s c o n s i d e r e d t o be W h i f f e n ' s v i b r a t i o n ( s ) ; t h e same v i b r a t i o n o c c u r s a t 618 c m - 1 i n P h 2 P 2 I 2 . The b a n d a t 525 cm" 1 i s b e l i e v e d t o be A t h e F - s e n s . ( t ) v i b r a t i o n t h a t o c c u r s a t 522 cm A ( m - F C g H ^ P I ) 2 . The s t r o n g a b s o r p t i o n a t 478 cm i s a s s i g n e d a s P-P s t r e t c h i n g b y c o m p a r i s o n w i t h b o t h P h 2 P 2 I 2 a n d ( m - F C g H ^ P I ) 2 . The r e l a t i v e l y s t r o n g b a n d a t 424 c m - 1 i s l i k e l y t h e P - s e n s . ( t ) v i b r a t i o n ; s u c h a n a s s i g n m e n t i s s u p p o r t e d b y t h e f a c t t h a t £ - F C g H 4 P C l 2 h a s a p o l a r i z e d b a n d — 1 —1 a t 424 cm . The weak v i b r a t i o n a t 414 cm may be W h i f f e n ' s v i b r a t i o n ( w ) , a n o u t - o f - p l a n e r i n g d e f o r m a t i o n ; -1 -1 t h e weak b a n d s a t 404 cm i n P h 2 P 2 I 2 a n d 410 cm i n ( m - F C g H 4 P I ) 2 a r e m o s t l i k e l y due t o t h e same v i b r a t i o n . _ -i By v i r t u e o f i t s g r e a t s t r e n g t h , t h e b a n d a t 366 cm i s a s s i g n e d a s P - I s t r e t c h i n g . T h i s s h i f t t o h i g h e r f r e q u e n c y w i t h r e s p e c t t o P h 2 P 2 I 2 a n d (m-FCgH^PI),, i n d i c a t e s t h a t t h e P - I b o n d h a s b e e n s i g n i f i c a n t l y s t r e n g t h e n e d i n (p_-FCgH 4PI) 2 . The e f f e c t o f p a r a - f l u o r o p h e n y l g r o u p s o n c e r t a i n v i b r a t i o n a l f r e q u e n c i e s w i l l be c o n s i d e r e d l a t e r i n t h e d i s c u s s i o n . p _ - F C g H 4 P C l 2 h a s a weak b a n d a t 385 cm w h i l e (jJ-FCgH^PI) 2 h a s a m o d e r a t e l y s t r o n g b a n d a t 387 cm b u t w h e t h e r o r n o t t h e same v i b r a t i o n i s r e s p o n s i b l e i s u n c e r t a i n . The b a n d a t 318 cm i s f o u n d t o o c c u r i n t h e spectra of other para-fluorophenyl compounds and may "be due' to a f l u o r i n e - s e n s i t i v e v i b r a t i o n of the phenyl r i n g . The Four-Membered Ring System (R,,?^) A wide v a r i e t y of compounds of general formula 1 1 R — 1 2 0 R 2 P 2 S 4 h a s D e e n synthesized . •The c r y s t a l structure of MegP^S^ has been solved and the molecule has been found to possess a planar four-mernbered P2^2 p i n g a s shown below. Me S S S Me 19 Space group data f o r P h 2 P 2 S 4 show that t h i s mole-cule also has a centre of symmetry. Despite the d i v e r s i t y of compounds of t h i s type that have been made, very few R ? spectroscopic data have been reported. Thus, Maier reports the i n f r a r e d spectrum of Ph2P2S 4 i n the region — 1 1 800-640 cm and assigns the strong absorption at 655 cm as 1>(P=S); Fluck and B i n d e r 1 2 2 report the 5 1 P n.m.r. of P h 2 P 2 S 4 as c o n s i s t i n g of a s i n g l e t at -15.4 p.p.m. r e l a t i v e to P^Og. As a r e s u l t , the compounds Yi^^^,^ P l ^ P j S ^ and i t s fluorophenyl analogues have been examined spectro-s c o p i c a l l y i n very much greater d e t a i l than has been - 1 3 6 -TABLE V I I MASS SPECTRA OP M e ^ P ^ , P h 2 P 2 S 4 and (p_-FC 6R" 4PS 2) 2 M e 2 P 2 S 4 P e a k ( m / e ) A b u n d a n c e A s s i g n m e n t 220 49.1 M e 2 P 2 S 4 110 100 M e P S 2 95 20.7 P S 2 78 19.2 MePS 63 7 3 . 1 PS 47 19.2 SMe/MePH 45 12.9 C H 2 P P h 2 P 2 s 4 P e a k ( m / e ) A b u n d a n c e A s s i g n m e n t ^ 344 2.8 P h 2 P 2 S 4 249 2.2 P h 2 P S 2 172 100 P h P S 2 109 PhPH 108 9.9 PhP 107 C 6 H 4 P 77 11.8 C 6 H 5 63 53.8 PS ( p _ - P C 6 H 4 P S 2 ) 2 P e a k ( m / e ) A b u n d a n c e Assignment^" 1"^ 380 6.1 ( P C 6 H 4 P S 2 ) 2 t i l 3 ' 8 P C 6 H 4 P 2 S 4 253 1.7 F C 6 H 4 P 2 S 3 190 100 P C 6 H 4 P S 2 ^ 8 7.1 F C 6 H 4 P S 1 2 6 13.4 F C 6 H 4 P 95 4.6 P C 6 H 63 70.4 PS - 1 3 7 -r e p o r t e d p r e v i o u s l y . The mass s p e c t r a o f M e ^ S ^ , P h g P g S ^ a n d ( j j - F C g H ^ P S ^ 2 a r e r e p o r t e d i n T a b l e V I I . I n e a c h c a s e , t h e f r a g m e n t a -t i o n p a t t e r n i s s i m i l a r , t h e b a s e p e a k b e i n g t h e mono-m e r i c s p e c i e s R P S 2 + a n d a s t r o n g p e a k o c c u r r i n g f o r t h e P S + i o n . I n c o n t r a s t t o o t h e r mass s p e c t r a r e p o r t e d i n t h i s s e c t i o n , t h e s p e c t r a o f t h e s e t h r e e compounds do n o t e x h i b i t m o l e c u l a r i o n s w h i c h h a v e u n d e r g o n e c o n s i d e r a b l e r e a r r a n g e m e n t . As r e p o r t e d i n t h e e x p e r i m e n t a l s e c t i o n , t h e p r o t o n n.m.r. o f M e 2 P 2 S 4 c o n s i s t s o f a d o u b l e t c e n t r e d a t t h e v e r y l o w c h e m i c a l s h i f t v a l u e o f 7.50 T , J ? H = 14 H z . T h i s r e s u l t w i l l be c o n s i d e r e d l a t e r i n t h e d i s c u s s i o n t o -g e t h e r w i t h t h e ^F n.m.r. d a t a o f t h e f l u o r o p h e n y l d e r i v -a t i v e s . The i n f r a r e d a n d Raman s p e c t r a o f M e 2 P 2 S 4 , P h 2 P 2 S 4 a n d ( j j - F C g H ^ P S ^ g a r e r e p o r t e d i n T a b l e s V I I I a n d I X . C o m p l e t e v i b r a t i o n a l a s s i g n m e n t s a r e i m p o s s i b l e a s n o n e o f t h e s e compounds a r e s u f f i c i e n t l y s o l u b l e t o a l l o w a d e t e r -m i n a t i o n o f t h e d e g r e e o f p o l a r i z a t i o n o f t h e v a r i o u s v i b r a t i o n s . The a s s i g n m e n t o f v i b r a t i o n s i s a i d e d b y t h e f a c t t h a t M e 2 P 2 S 4 a n d P h 2 P 2 S 4 a r e known t o p o s s e s s a c e n t r e o f s y m m e t r y a n d c o n s e q u e n t l y t h e m u t u a l e x c l u s i o n p r i n c i p l e m u s t p r e v a i l . The v i b r a t i o n a l s p e c t r a o f M e 0 P 0 S „ a r e - 1 3 8 -TABLE V I I I S OLID STATE RAMAN SPECTRA OP COMPOUNDS R„P„S R=Me FREQUENCY R E L A T I V E ASSIGNMENT (cm"" 1) I N T E N S I T Y 2993 n e g . i 7 a s . ( G " " H ) 2905 0.2 V3'(C-K) 1 4 0 7 , 1 4 0 2 n e g . S a s[(C-H) 1 2 7 6 , 1 2 7 4 n e g . g s[(C-H) 905 0.3 p(C-H) 7 5 2 0.3 y s . ^ P " C ) 658 0.7 1>S"(P=S) 447 10 / / ( P - S ) 421 4.2 V ( P - S ) 318 0.5 269 0.9 228 0.3 179 4.5 103 0.4 R=Ph FREQUENCY R E L A T I V E ASSIGNMENT (cm"" 1) I N T E N S I T Y h i g h e r f r e q u e n c i e s n o t r e c o r d e d 726 1.2 s e e t e x t 686 1.9 P - s e n s . ( r ) 616 0.6 v i b . ( s ) 502 10 Z^(P-S) 470 2.1 P - s e n s . ( t ) 410 4.9 s e e t e x t 396 6.1 s e e t e x t 328 1.0 270 2.0 210 2.1 191 3.4 1 7 4 3 ( c o n t i n u e d o v e r l e a f ) 1 43 1.8 neg.= n e g l i g i b l e - 1 3 9 -TABLE V I I I ( c o n t . ) R = £ - F C 6 H 4 FREQUENCY R E L A T I V E ASSIGNMENT ( c m - 1 ) I N T E N S I T Y h i g h e r f r e q u e n c i e s n o t r e c o r d e d 698 2.5 645 0.2 626 0.3 48 1 10 419 8.3 404 2.0 387 5.3 353 1.8 310 0.5 225 1.2 196 0.7 173 3.1 91 2.5 TABLE IX SOLID STATE INFRARED SPECTRA OP COMPOUNDS R 2 P2 S4 R=Me R=Pha PREQ. RELATIVE ASSIGNMENT PREQ. RELATIVE ASSIGNMENT PREQ. RELATIVE ASSIGNMENT (cm" 1) INTENSITY (cm" 1) INTENSITY (cm*1) INTENSITY 1276 m ^ B B ( C - H ) 719 s see text 758 w 900,892 s P (C-H) 655 vs V ( P = S ) 685 vs i> ( P = S ) 756 s y a s . < p - ° > 610 m,sharp vib.(s) 625 s 617 vs ^as.< P = S) 563 s y ( p - s ) 602 s 531 s V (P-S) 473 s P-sens.(t) 555 s 422 s V (P-S) 448 s V (P-S) 450 s 263 mw 346 w 415 sh 239 m 292 w 331 m 150 m v=very; w= weak; ir i=medium; s= strong; sh=shoulder 465 cm - 1) a. spectrum includes those peaks l i s t e d i n Table IV, column I (exc. b. spectrum includes those peaks l i s t e d In Table IV, column III(exc .510 and 405 cm"1) I H O I -141-easiest to i n t e r p r e t . Antisymmetric C-H str e t c h i n g i s seen -1 — 1 at 2993 cm , and symmetric C-H stre t c h i n g , at 2905.cm . Symmetric C-H bending i s seen at 1274 and 1276 cm""1; a n t i -symmetric C-H bending i s seen at 1407 and 1402 cm"1. The -t C-H rocking v i b r a t i o n i s seen at 905 cm (Raman) and at 892, 900 cm"1 ( i n f r a r e d ) . Absorptions;at 752 cm - 1 (Raman) and 756 cm (infrared) are assigned to the symmetric and antisymmetric P-C s t r e t c h r e s p e c t i v e l y . These values are t y p i c a l of pentavalent phosphorus-carbon s t r e t c h i n g 112 —1 frequencies . The strong band at 617 cm i n the in f r a r e d spectrum i s the only band which f a l l s i n the normal region f o r V (P=S) and i t i s therefore assigned as the antisymmetric P=S s t r e t c h . The only band i n t h i s region i n the Raman spectrum (658 cm"1) i s considered to 114 be the symmetric P=S s t r e t c h . Cowley and White also found the symmetric P=S s t r e t c h to occur at higher f r e -quencies than the antisymmetric P=S s t r e t c h i n the d i -phosphine disulphides Me^P^,,, E t ^ P , ^ and Bu^PgS^. In addition, the antisymmetric s t r e t c h i s l i s t e d as being a very strong absorption while the Raman-active symmetric s t r e t c h i s l i s t e d as being of only medium i n t e n s i t y . These observations are consistent with what has been ob-112 tained f o r Me^gS^. Corbridge considers the normal P-S str e t c h i n g frequency range to l i e between 400 and _ -i 550 cm . Such a frequency range i s much more reasonable _ -i than the region 550-600 cm which has been suggested by 8S some workers . Neither Me 0P 9S. nor P..S, has any - 1 4 2 -a b s o r p t i o n i n t h e r e g i o n 5 50-600 cm""'; i n f a c t , t h e h i g h -_ i e s t a b s o r p t i o n i n P^S^ o c c u r s a t 489 cm . F o u r a b s o r p -t i o n b a n d s a r e s e e n i n t h e r e g i o n 4 0 0 - 5 5 0 cm , two i n t h e i n f r a r e d s p e c t r u m ( 5 3 1 , 422 cm ) a n d two i n t h e Raman s p e c t r u m ( 4 4 7 , 4 2 1 cm"" ) a s w o u l d be e x p e c t e d . By v i r t u e — 1 o f i t s g r e a t i n t e n s i t y , t h e s t r o n g e s t Raman b a n d ( 4 4 7 cm ) i s m o s t l i k e l y t h e t o t a l l y s y m m e t r i c P-S s t r e t c h . The i n f r a r e d - a c t i v e b a n d a t 422 cm"*1 and t h e R a m a n - a c t i v e b a n d a t 4 21 cm a r e c o n s i d e r e d t o b e l o n g t o d i f f e r e n t s y m m e t r y s p e c i e s a s b o t h a r e v e r y s t r o n g p e a k s . A s m e n t i o n e d p r e -v i o u s l y , Ke^2^A* h a v i n g a c e n t r e o f s y m m e t r y , i s n o t e x p e c t e d t o h a v e a n y i n f r a r e d a n d Raman c o i n c i d e n c e s ; i f s u c h c o i n c i d e n c e s do o c c u r , i t i s u n l i k e l y t h a t t h e v i b r a -t i o n w o u l d be v e r y s t r o n g i n b o t h t h e i n f r a r e d a n d Raman s p e c t r a . I n a n y c a s e , a n a c c i d e n t a l c o i n c i d e n c e i s n o t u n r e a s o n a b l e s i n c e t h e v a r i o u s P-S s t r e t c h i n g v i b r a t i o n s a r e c l o s e l y r e l a t e d a n d w o u l d be e x p e c t e d t o r e q u i r e s i m i l a r e n e r g i e s . The r e m a i n i n g v i b r a t i o n s a r e t o o d i f f i -c u l t t o a s s i g n w i t h o u t p o l a r i z a t i o n d a t a ; n i n e Raman-a c t i v e f u n d a m e n t a l s a r e e x p e c t e d h o w e v e r , ( t r e a t i n g t h e m e t h y l g r o u p s a s p o i n t m a s s e s ) a n d n i n e a r e o b s e r v e d . S e v e n o f t h e n i n e i n f r a r e d - a c t i v e f u n d a m e n t a l s a r e s e e n , i f t h e i n f r a r e d - R a m a n c o i n c i d e n c e s o f 4 2 2 - 4 2 1 cm and 2 6 3 -269 cm""1 a r e t r e a t e d a s b e i n g a c c i d e n t a l . The v i b r a t i o n a l s p e c t r a o f P h 2 P 2 S 4 a r e somewhat more c o m p l i c a t e d ; t h e v e r y s t r o n g b r o a d i n f r a r e d - a c t i v e b a n d - 1 4 3 -a t 655 cm""1 i s a s s i g n e d a s a n t i s y m m e t r i c P=S s t r e t c h i n g , n o t o n l y b e c a u s e o f i t s s t r e n g t h b u t a l s o b e c a u s e o f t h e s i m i l a r i t y o f t h e b a n d s h a p e t o t h a t o b s e r v e d f o r t h e a n t i -s y m m e t r i c P=S s t r e t c h i n Ke^P^S^. The o n l y o t h e r b a n d i n t h i s r e g i o n w h i c h m i g h t q u a l i f y a s t h e a n t i s y m m e t r i c P=S s t r e t c h i s t h e s t r o n g s h a r p i n f r a r e d - a c t i v e b a n d a t 719 cm . No a s s i g n m e n t h a s b e e n made f o r t h i s b a n d e v e n t h o u g h i t a p p e a r s r e p e a t e d l y i n compounds c o n t a i n i n g P h - P ( S ) C ^ l i n k a g e s ; f o r e x a m p l e , a c o m p a r i s o n o f t h e i n f r a r e d s p e c t r a o f Ph^P a n d Ph^P=S r e v e a l s t h a t s t r o n g — 1 — 1 a b s o r p t i o n s a p p e a r a t 7 1 2 cm a n d 632 cm i n t h e s p e c -t r u m o f P h 3 P = S . The b a n d a t 632 c m - 1 h a s b e e n a s s i g n e d 1 2 4 a s P=S s t r e t c h i n g b u t no m e n t i o n was made o f t h e 7 1 2 cm b a n d e v e n t h o u g h i t i s s l i g h t l y more i n t e n s e t h a n t h e — 1 125 632 cm b a n d . C h i t t e n d e n a n d Thomas J h a v e s u g g e s t e d t h a t t h e P=S b o n d i s c h a r a c t e r i z e d b y two i n f r a r e d a b s o r p -1 ?fi t i o n s ; h o w e v e r , a c c o r d i n g t o o t h e r w o r k e r s t h e a s s o c i -a t i o n o f two a b s o r p t i o n s w i t h P=S s t r e t c h i n g seems t o be i n c o r r e c t . The s h a r p b a n d s a t 610 cm i n t h e i n f r a r e d — 1 s p e c t r u m , a n d 616 cm i n t h e Raman s p e c t r u m , a r e a s s i g n e d a s t h e C-C-C i n - p l a n e r i n g d e f o r m a t i o n , v i b r a t i o n ( s ) i n W h i f f e n ' s n o t a t i o n . The R a m a n - a c t i v e b a n d a t 686 cm i s c o n s i d e r e d t o be t h e P - s e n s . ( r ) v i b r a t i o n o f t h e p h e n y l r i n g ; t h i s v i b r a t i o n was o b s e r v e d t o be r e l a t i v e l y u n -a f f e c t e d i n p a s s i n g f r o m P h P H 2 ( 6 9 3 cm""1) t o P h P C l 2 ( 7 0 1 — 1 — 1 cm ) . The R a m a n - a c t i v e b a n d a t 7 2 6 cm may b e t h e sym-m e t r i c P=S s t r e t c h b u t t h e p o s s i b i l i t y t h a t i t i s due t o - 1 4 4 -t h e same v i b r a t i o n a s i s o b s e r v e d a t 719 c m - ' i n t h e i n f r a -r e d s p e c t r u m c a n n o t be e x c l u d e d . The i n f r a r e d a c t i v e b a n d — 1 —1 a t 473 cm , and t h e R a m a n - a c t i v e band, a t 470 cm , a r e a s s i g n e d a s t h e P - s e n s . ( t ) v i b r a t i o n t h a t was o b s e r v e d a t 465 cm f o r P h 2 P 2 I 2 . The s t r o n g i n f r a r e d - a c t i v e a b s o r p -_ -i t i o n s a t 563 a n d 448 cm a r e c o n s i d e r e d t o be t h e two e x p e c t e d i n f r a r e d - a c t i v e P-S s t r e t c h e s ; t h e s t r o n g e s t Raman b a n d , 502 cm , i s a s s i g n e d a s t h e t o t a l l y s y m m e t r i c P-S s t r e t c h b y a n a l o g y t o MegPgS^. The o t h e r R a m a n - a c t i v e P-S s t r e t c h o c c u r s a t e i t h e r 410 o r 396 cm . No f u r t h e r a s s i g n m e n t s h a v e b e e n a t t e m p t e d f o r P J ^ P g S ^ . The P=S s t r e t c h i n g f r e q u e n c i e s h a v e b e e n i d e n t i f i e d a s o c c u r r i n g a t 652 cm- 1 i n ( m - F C g H ^ P S ^ 2 a n d a t 687 cm""1 i n (p_-FCgR" 4PS 2)2 ' The h i g h e r f r e q u e n c y o b s e r v e d i n ( p _ - F C g H " 4 P S 2 ) 2 i n d i c a t e s t h a t t h e P=S b o n d h a s b e e n s t r e n g -t h e n e d b y c o n j u g a t i v e i n t e r a c t i o n w i t h t h e p _ - f l u o r o p h e n y l g r o u p . The C y c l o t e t r a p h o s p h i n e M o n o s u l p h i d e s ( R ^ P ^ S ) T e t r a p h e n y l c y c l o t e t r a p h o s p h i n e m o n o s u l p h i d e ( P h ^ P ^ S ) 8 ? h a s b e e n p r e p a r e d b y M a i e r who r e p o r t e d i t s i n f r a r e d s p e c t r u m i n t h e r e g i o n 8 0 0 - 6 0 0 cm a n d a m o l e c u l a r w e i g h t d e t e r m i n a t i o n . On t h e b a s i s o f t h i s r a t h e r s c a n t i n f o r m a -t i o n , M a i e r p o s t u l a t e d t h a t Ph^P^S c o n s i s t s o f a f o u r -membered p h o s p h o r u s r i n g a s shown. Ph Ph \ P P s p p \ Ph Ph A c l o s e i n s p e c t i o n o f t h e v i b r a t i o n a l s p e c t r o s c o p i c d a t a ( T a b l e X l l ) r e v e a l s t h a t t h e r e i s no b a n d w h i c h c a n be r e a d i l y a s s i g n e d a s a P=S s t r e t c h i n g f r e q u e n c y . T h e r e w i t h t h e s t r o n g i n f r a r e d - a c t i v e p h e n y l v i b r a t i o n s a t 680 a n d 7 4 0 era . S u c h a c o i n c i d e n c e a p p a r e n t l y o c c u r s i n t h e i n f r a r e d s p e c t r u m o f PhP(S)Cl2» i n w h i c h o n l y t h e s e two 1 27 s t r o n g p h e n y l v i b r a t i o n s a r e s e e n i n t h e r e g i o n 6 0 0 -— 1 8 0 0 cm . B e c a u s e o f t h i s p o s s i b i l i t y , a n d a l s o b e c a u s e 31 o f t h e f a i l u r e t o o b t a i n a n a d e q u a t e P n.m.r. s p e c t r u m , t h e s t r u c t u r e o f P h ^P^S was d e t e r m i n e d b y a s i n g l e c r y s t a l 1 28 X - r a y d i f f r a c t i o n s t u d y , a n d was f o u n d t o c o n s i s t o f a f i v e - m e m b e r e d P^S r i n g , a n d n o t a f o u r - m e m b e r e d p h o s p h o r u s O p r i n g a s M a i e r h a d p o s t u l a t e d . T h e P^S r i n g i s n o n - p l a n a r , a s shown i n F i g u r e s 6 a n d 7, d e v i a t i o n s f r o m t h e mean p l a n e b e i n g : P ( l ) , 0 . 1 9 ; P ( 2 ) , - 0 . 2 4 ; P ( 3 ) , 0.24; P ( 4 ) , - 0 . 1 5 : S, - 0 . 0 2 A 0 . The mean b o n d l e n g t h s are.: P-P, 2.190(5)A°; FIG.6: Molecular structure of Ph.RS FIG. 7' Arrangement of phenyl groups in Ph f^^ S - 1 4 8 -TABLB X MOLECULAR STRUCTURE OP Ph.P.S a. Mean b o n d l e n g t h s (A°) P-S 2 . 1 1 6 ( 5 ) P-P 2 . 1 9 0 ( 5 ) P-C 1 . 8 3 1 ( 2 2 ) C-C 1 . 3 8 2 ( 1 6 ) b. E n d o c y c l i c b o nd a n g l e s ( d e g . ) < P x 1 0 5 . 9 ( 2 ) < P 2 1 0 4 . 2 ( 2 ) < P 3 1 0 5 . 1 ( 2 ) < P 4 1 0 5 . 6 ( 2 ) mean < P 105.2 < S 1 1 0 . 4 ( 2 ) D i h e d r a l a n g l e s ( d e g . ) i n t h e P^S r i n g A toms P ( l ) - P ( 2 ) - P ( 3 ) - P ( 4 ) P ( 2 ) - P ( 3 ) - P ( 4 ) - S P ( 3 ) - P ( 4 ) - S - P ( l ) P ( 4 ) - S - P ( l ) - P ( 2 ) S - P ( l ) - P ( 2 ) - P ( 3 ) A n g l e - 2 9.9 +23.0 -7 . 1 -11.7 +25.6 - 1 4 9 -P-S, 2.116(5)A°; P-C, 1.831(22)A°; C-C, 1.382(16)A°. O t h e r u s e f u l d a t a a r e p r e s e n t e d i n T a b l e X . The p h e n y l g r o u p s a r e n e a r l y p e r p e n d i c u l a r t o t h e mean p l a n e o f t h e P^S r i n g , t h e p a i r s o n t h e same s i d e o f t h e r i n g b e i n g r o u g h l y p a r a l -l e l t o e a c h o t h e r , b u t p e r p e n d i c u l a r t o t h e o t h e r p a i r . The n e a r e q u a l i t y o f t h e a n g l e s a t p h o s p h o r u s ( T a b l e X ) i s t o b e c o n t r a s t e d w i t h t h e v a r i a b i l i t y o f t h o s e i n P h 5 P 5 1 2 9 , i n w h i c h t h e a n g l e s r a n g e f r o m 94.1° t o 107.2°, mean 100°. The s t a b i l i t y o f t h e m o n o s u l p h i d e , i n d i c a t e d b y t h e v a r i e t y o f s y n t h e t i c m e t h o d s a n d t h e d i f f i c u l t y o f r e m o v i n g t h e r e m a i n i n g s u l p h u r w i t h t r i b u t y l p h o s p h i n e , may be due i n p a r t t o t h e l a r g e r a n d more r e g u l a r a n g l e s a t p h o s p h o r u s , t h e m s e l v e s a r e s u l t o f r e d u c e d s t e r i c r e p u l s i o n s o f t h e p h e n y l g r o u p s . The mass s p e c t r a o f Ph^P^S and (-g-FCgH^P^S a r e p r e -s e n t e d i n T a b l e X I . S u r p r i s i n g l y , t h e s t r o n g e s t p e a k s a r e t h o s e i n w h i c h e i t h e r one o r two p h e n y l g r o u p s h a v e m i -g r a t e d t o t h e same p h o s p h o r u s a t o m ; h e n c e , t h e s t r o n g e s t p e a k s i n t h e mass s p e c t r u m o f Ph^P^S a r e due t o t h e i o n s P h 5 P + , P h 2 P + a n d ( C g R ^ ) ^ ; t h e l a t t e r f r a g m e n t i s b e l i e v e d t o be t h e m o l e c u l a r i o n o f 9 - p h o s p h a f l u o r e n e t h a t i s a l s o p r o m i n e n t i n t h e mass s p e c t r u m o f Ph 2P2l2» ^ n e P _ - f l u o r o -p h e n y l a n a l o g u e s o f t h e s e t h r e e i o n s a r e t h e m o s t i n t e n s e p e a k s i n t h e mass s p e c t r u m o f ( j s - F C g H ^ P ) ^ S . S e v e r a l o t h e r f r a g m e n t s a r e s e e n i n t h e mass s p e c t r u m o f Ph^P^S w h i c h i n d i c a t e t h a t s i g n i f i c a n t r e a r r a n g e m e n t h a s o c c u r r e d , - 1 5 0 -TABLE X I MASS SPECTRAL RESULTS FOR P h 4 P 4 S a n d (p _ - F C 6 H 4 P ) 4 S ?V4S ( p _ - F C 6 H 4 P ) 4 S PEAK (m/e) ABUNDANCE A S S I G N M E N T ^ PEAK (m/e) ABUNDANCE A S S I G N M E N T ^ 540 0.8 P h 5 P 5 P h 4 P 4 S 2 536 47 ( F C 6 H 4 P ) 4 S 496 0.3 378 32 ( F C 6 H 4 P ) 3 464 57 *V4s 347 13 ( F C 6 H 4 ) 3 P 2 432 2.3 P h 4 P 4 316 70 ( F C 6 H 4 ) 3 P 4 0 1 2.7 P h 4 P 3 284 26 ( F C 6 H 4 P ) 2 S 388 2.4 P h 5 P 3 S 2 252 10 ( F C 6 H 4 P ) 2 370 1.5 P h 4 P 2 221 100 ( F C 6 H 4 ) 2 P 356 1.7 P h 5 P 3 S 219 62 ( F C 6 H 3 ) 2 P 324 18 P h 3 P 3 201 27 ( F C 6 H 3 ) P ( C 6 H 4 ) 293 35 P h 3 P 2 157 32 F C 6 H 4 P 2 279 2.4 P h 2 P 3 S 126 28 F C 6 H 4 P 262 100 P h 3 P 125 39 F C 6 H 3 P 248 232 16 n e g . P h 2 P 2 S (Ph 4P 4 s ) 2 + 107 95 25 17 G 6 H 4 P  F C 6 H 4 217 8 P h 2 P S 63 12 PS 185 80 P h 2 P 183 95 ( C 6 H 4 ) 2 P 170 8 P h P 3 139 25 P h P 2 108 43 PhP 107 19 C 6 H 4 P 77 34 P h 63 7 PS 52 10 ° 4 H 4 - 1 5 1 -s p e c i f i c a l l y t h e i o n s P h ^ " 1 " , P h ^ S ^ , P h ^ P ^ " 1 " and P h 4 ? 2 + . The compound ( C F ^ P ^ S i s b e l i e v e d 1 5 0 t o p o s s e s s a f i v e - m e m b e r e d P^S r i n g o n t h e b a s i s o f h y d r o l y s i s e x p e r i -m e n t s ; i t s mass s p e c t r u m h a s b e e n r e p o r t e d a n d shows s i g n i f i c a n t d i f f e r e n c e s f r o m t h a t o f P h ^ P ^ S . The s p e c t r a a r e m a i n l y d i f f e r e n t b e c a u s e o f t h e g r e a t l y d i f f e r i n g a b i l -i t y o f t h e p h o s p h o r u s s u b s t i t u e n t s t o s t a b i l i z e t h e m o l e -c u l a r f r a g m e n t ; t h u s , i n t h e mass s p e c t r u m o f ( C P ^ P j ^ S , t h e m a j o r i o n s a r e o f l o w m o l e c u l a r w e i g h t and t h e p a r e n t i o n i s P S + . L a r g e r f r a g m e n t s a r e much more s t a b l e i n t h e mass s p e c t r u m o f P h ^ P ^ S ; f o r e x a m p l e , t h e a b u n d a n c e o f P S + i s o n l y 7% o f t h e b a s e p e a k , Ph^P"*". The i o n ( C F ^ ) 3 P + d o e s n o t a p p e a r i n t h e mass s p e c t r u m o f ( C F ^ P ^ S e v e n t h o u g h i t s p h e n y l a n a l o g u e i s t h e b a s e p e a k i n t h a t o f P h ^ P ^ S . The f l u o r i n e c h e m i c a l s h i f t s o f m- and ( p _ - F C 6 H " 4 P ) , t o g e t h e r w i t h t h e c a l c u l a t e d i n d u c t i v e a n d r e s o n a n c e p a r a -m e t e r s , a r e r e p o r t e d i n T a b l e I I . A s m i g h t be e x p e c t e d , two f l u o r i n e r e s o n a n c e s o f e q u a l a r e a a r e s e e n i n e a c h s p e c t r u m ; one r e s o n a n c e i s a t t r i b u t e d t o t h e f l u o r o p h e n y l g r o u p s a t t a c h e d t o t h e two p h o s p h o r u s a t o m s a d j a c e n t t o s u l p h u r , a nd t h e s e c o n d r e s o n a n c e i s a t t r i b u t e d t o t h e f l u o r o p h e n y l g r o u p s a t t a c h e d t o t h e r e m a i n i n g two p h o s p h o r u s a t o m s . T h e s e r e s u l t s i n d i c a t e t h a t t h e s t r u c t u r e o f P h A P A S i s u n a l t e r e d u p o n d i s s o l u t i o n . - 1 5 2 -TABLE X I I VIBRATIONAL SPECTRA OP P h ^ S AND ( j j - F C g ^ P ) 4 S INFRARED SPECTRAL RESULTS P h 4 F 4 S -1 ( £ - F C 6 H 4 P ) 4 S F R E Q U E N C Y ( c m - 1 ) I N T E N S I T Y F R E Q U E N C Y ( c m - 1 ) I N T E N S I T Y 505 483 464 454 429 398 306 w w m ms w m w 615 490 455 435 400 350 328 w s h a r p w w w w w • i n c l u d e s p e r t i n e n t v i b r a t i o n s l i s t e d i n T a b l e I I w=weak; m=medium; s = s t r o n g RAMAN SPECTRAL RESULTS F R E Q U E N C Y ( c m - 1 ) I N T E N S I T Y FREQUENCY(cm"') I N T E N S I T Y -1 1029 2.3 828 1.2 100 1 5.1 634 0.8 690 0.4 618 1.7 620 0.2 460 1.1 513 0.4 446 1.0 492 0.1 422 3.0 450 1.3 406 10 437 6.4 374 0.2 406 0.2 359 0.7 371 10 341 1.6 315 1.6 313 2.5 300 2.9 301 2.8 284 0.8 276 0.8 264 0.4 258 0.4 252 0.7 225 0.1 218 2.3 199 2.0 184 2.5 188 1.4 - 1 5 3 -The i n f r a r e d a n d Raman s p e c t r a o f Ph^P^S a n d (p_-FCgH 4P) ^ S a r e r e p o r t e d i n T a b l e X I I . B o t h compounds a r e c h a r a c t e r i z e d b y weak t o medium i n f r a r e d a b s o r p t i o n i n t h e r e g i o n r e p o r t e d i n t h i s T a b l e ; b y c o n t r a s t , t h e Raman a b s o r p t i o n i s q u i t e s t r o n g . The s t r o n g e s t b a n d s i n t h e Raman s p e c t r u m o f Ph^P^S a p p e a r a t 437 a n d 371 cm , and c a n be c o n s i d e r e d a s e i t h e r P-P o r P-S s t r e t c h i n g . A m s t e r a n d C o l t h u p 1 ^ 4 h a v e a s s i g n e d b a n d s i n t h e r e g i o n o f — 1 — 1 488-417 cm and 4 0 9 - 3 9 1 cm a s a s y m m e t r i c a n d s y m m e t r i c r i n g s t r e t c h i n g modes r e s p e c t i v e l y i n a l k y l c y c l o p o l y -p h o s p h i n e s . The Raman b a n d a t 450 cm""1, a n d t h e i n f r a r e d b a n d a t 454 cm , a r e m o s t l i k e l y d u e t o t h e P - s e n s ( t ) v i b r a t i o n . I n g e n e r a l , a s s i g n m e n t s a r e v e r y d i f f i c u l t b e c a u s e o f t h e g r e a t number o f v i b r a t i o n s t h a t a r i s e f r o m t h e l o w s y m m e t r y o f t h e s e two m o l e c u l e s . The C y c l o t r i p h o s p h i n e T r i s u l p h i d e s (R^S^S^) The r e a c t i o n o f s u l p h u r w i t h Ph^P^S r e s u l t s i n f o r m -a t i o n o f t r i p h e n y l c y c l o t r i p h o s p h i n e t r i s u l p h i d e , P h ^ P ^ S ^ . A s m e n t i o n e d i n t h e i n t r o d u c t i o n , t h e r e h a s b e e n d i s a g r e e -ment a n d u n c e r t a i n t y a b o u t t h e s t r u c t u r e o f t h i s compound. 132 A n e r r o n e o u s m o l e c u l e w e i g h t d e t e r m i n a t i o n , s u g g e s t i n g t h a t t h i s compound was a t e t r a m e r , was n o t d e t e c t e d b y O p A ' M a i e r a n d a p p a r e n t l y e s c a p e d u n n o t i c e d u n t i l A b e l e_t a l . r e p o r t e d a m o l e c u l a r w e i g h t d e t e r m i n a t i o n i n a g r e e m e n t w i t h a t r i m e r i c s t r u c t u r e . M a i e r a n d D a l y t h e n r e p o r t e d - 1 5 4 -space group data c o n f i r m i n g the t r i m e r i c nature of Ph,P,S,. S i x p o s s i b l e s t r u c t u r e s of Ph.,PvS, have been ) ) ) 5 J o i l l u s t r a t e d i n a l a t e r a r t i c l e by Maier •„ f o u r of these s t r u c t u r e s are i l l u s t r a t e d below. a b c d S t r u c t u r e (a) was suggested by Abel et a l . and was appar-• •>; *z f o n - >.•>. • «,"?ic,^- ' P " " / l V c n+ -o T -f fl'V<MTV>*»-^ C i t o j . ^ i a v u u l c u uj i ' ; a l c i • j - c - . > — '- . i a V v U i c - . i s t r u c t u r e (b) on the b a s i s of i n f r a r e d and mass s p e c t r a l r e s u l t s . The mass s p e c t r a of Ph^P^S^ a n d (^-FC-gH^PS)^ are repo r t e d i n Table X I I I . In each case, the h i g h r e a c -t i v i t y of these compounds r e s u l t s i n peaks which can be exp l a i n e d o n l y i n terms of o x i d a t i o n or h y d r o l y s i s products of the s t a r t i n g m a t e r i a l s ; thus, the parent i o n (P) of Ph^P^S^ i s observed at m/e 420 and peaks present at m/e P+16, P+32 and P+48 are most l i k e l y due t o o x i d a t i o n although the peak at m/e P+32 may w e l l correspond i n p a r t to Ph^P^S^. The mol e c u l a r i o n at m/e 464 has been pre-85 + v i o u s l y assigned as Ph^P^S^CE^ • T } l e h i g h r e a c t i v i t y of (jD-FCgH^PS)^ i s i l l u s t r a t e d by s t r o n g peaks a t m/e 128 - 1 5 5 -T ABLE X I I I MASS SPECTRAL RESULTS FOR P h * P , S , AND ( p ^ F C . H . P S ) P h 5 P7S7 3 3 ( £ - F C 6 H 4 P S ) 3 PEAK ABUNDANCE A S S I G N M E N T ^ PEAK ABUNDANCE ASSIGNMENT^"1" (m/e) (m/e) 468 7.1 P h 3 P 3 S 3 0 3 474 2.8 ( F C 6 H 4 P S ) 3 464 0.8 P h 3 P 3 S 4 C H 2 442 1 5 . 1 ( F C 6 H 4 P ) 3 S 2 452 3.2 Ph 3P 3 s 3 o 2 /Ph 3P 3 s 4 284 23.2 ( F C 6 H 4 P ) 2 S 436 0.9 P h 3 P 3 S 3 0 253 6.5 ( F C 6 H 4 ) 2 P S 420 10.4 P h 3 ? 3 S 3 221 37.4 ( P C 6 H 4 ) 2 P 388 21.3 P h 3 P 3 S 0 219 1 2 . 5 ( F C 6 H 3 ) 2 P 356 9.1 P h 3 P 3 S 190 10.0 F C 6 H 4 P S 2 324 7.1 3 3 160 45.0 F C 6 H 4 P ( O H ) 2 262 4.9 P h 3 P 128 7 6 . 1 F C 6 H 4 P H 2 248 100 Ph 2P 2 s 126 100 F C 6 H P 217 33 P h 2 P S 63 78.3 PS 185 100 P h 2 P 183 85.0 ( C 6 H 4 ) 2 P 1 7 2 21.7 P h P S 2 140 20.0 PhPS 108 19.3 PhP 107 52.1 C 6 H 4 P 63 45.2 PS - 1 5 6 -and m/e 1 6 0 , F C g H ^ P H ^ a n d F C g H ^ P C O H ) ^ r e s p e c t i v e l y . No m o l e c u l a r i o n s l a r g e r t h a n t h e p a r e n t i o n w e re s e e n i n t h e mass s p e c t r u m o f ( p j - F C g H ^ P S ) ^ . B a u d l e r e t a l . a r g u e d t h a t t h e p r e s e n c e o f p e a k s P h ^ P - ^ S ^ , P h ^ P ^ S * a n d P h 5 P 5 + i n t h e mass s p e c t r u m o f Ph^P^S^ was i n d i c a t i v e o f a s t e p -w i s e l o s s o f e x o c y c l i c s u l p h u r a t o m s f r o m a P^ r i n g ; how-e v e r , i t h a s b e e n d e m o n s t r a t e d t h a t s i g n i f i c a n t r e a r r a n g e -m e n t s a r e a common f e a t u r e o f t h e s e compounds a n d , i n p a r t -i c u l a r , i t i s w o r t h n o t i n g t h a t t h e a b u n d a n c e o f P h , P , + J 5 ( 7 . 1 % ) i s s i m i l a r t o t h a t o f P h 3 P + ( 4 . 9 % ) , a n d t h a t t h a t o f P h 5 P 5 S 2 + ( 2 1 . 3 % ) i s s i m i l a r t o t h a t o f P h P S 2 + ( 2 1 . 7 % ) . T h u s i t d o e s n o t seem j u s t i f i e d t o p r o p o s e t h a t Ph^P^S^ i s b a s e d o n a t h r e e - m e m b e r e d p h o s p h o r u s r i n g ; i n f a c t , t h e 1 9 F n.m.r. s p e c t r u m o f ( p _ - F C 6 H 4 P S ) 5 ( F i g . 8 ) shows t h r e e d i s t i n c t p e a k s o f r e l a t i v e a r e a 1 : 1 : 1 , i n d i c a t i n g t h e p r e s e n c e o f t h r e e d i f f e r e n t p h o s p h o r u s e n v i r o n m e n t s a n d s u g g e s t i n g t h a t P h ^ P ^ S ^ p o s s e s s e s s t r u c t u r e ( d ) . The 5 1 P n.m.r. s p e c t r u m ( F i g . 9 ) o f ( p ^ - F C g H ^ P S ) 5 i s o f t h e ABX t y p e , S A = - 3 6 . 8 , S f i = - 2 4 . 2 , S x = +45.7 p.p.m. ( e x t . P^Og) w i t h J A B = 245 H z . and £ A B : X = 2:1, c o n -f i r m i n g t h a t Ph^P^S^ c o n s i s t s o f a n u n s y m m e t r i c a l f i v e -membered r i n g ; f u r t h e r m o r e , t h e v e r y l a r g e AB c o u p l i n g c o n s t a n t i s i n d i c a t i v e o f a d i r e c t P-P b o n d . T h i s u n e x -p e c t e d s t r u c t u r e i s i d e n t i c a l t o t h a t o f one o f t h e r i n g s o f P 4 S 5 a n d t h e b a s i c ( P 2 ) ( S P S ) r i n g i s a l s o f o u n d i n P ^ a n d b o t h f o r m s o f P ^ S ^ I ^ FIG. 9; P n.m.r. spectrum of ( p-FC 6H 4PS ) 6^  = -36.8 p.p.m. SB=~24.2 p.p.m. 8 X = + 45.7 p.p.m. r — ^ v X (relative to ext. F^ Og) | , | - 1 5 9 -Th e i n f r a r e d a n d Raman s p e c t r a o f P h ^ P ^ S ^ a n d i t s f l u o r o p h e n y l d e r i v a t i v e s a r e r e p o r t e d i n T a b l e X I V . The l a c k o f s y m m e t r y o f t h e s e compounds a g a i n r e s u l t s i n a t r e m e n d o u s number o f i n f r a r e d a n d Raman v i b r a t i o n s ; c o n -s e q u e n t l y , f e w a s s i g n m e n t s h a v e b e e n made. The P=S s t r e t c h i n g f r e q u e n c y i s r e a d i l y s e e n i n e a c h o f t h e i n f r a -r e d s p e c t r a , h o w e v e r ; t h e s p e c t r u m o f ( j j - P C g H ^ P S ) ^  i s p a r t i c u l a r l y u s e f u l i n t h i s r e g a r d a s t h e s t r o n g C-H o u t -o f - p l a n e b e n d i n g v i b r a t i o n i s s h i f t e d t o much h i g h e r f r e -_ *i q u e n c i e s a n d t h e r e g i o n o f 6 0 0 - 7 0 0 cm i s g r e a t l y s i m p -_ -t l i f i e d . The v e r y s t r o n g b r o a d b a n d a t 673 cm i s t h e r e -f o r e c o n f i d e n t l y a s s i g n e d a s P=S s t r e t c h i n g ; b a n d s o f s i m i l a r s h a p e a nd i n t e n s i t y o c c u r a t 648 cm i n P h ^ P ^ S ^ and a t 646 cm" i n (m-FCgH^PS)^. A g a i n , t h e s t r o n g u n -_ -i e x p l a i n e d b a n d a t 7 1 0 cm w h i c h a p p e a r s t o be c h a r a c t -e r i s t i c o f P h P ( S ) C ^ l i n k a g e s i s p r e s e n t i n t h e i n f r a r e d _ A s p e c t r u m o f P h ^ P ^ S ^ ; t h e s t r o n g s h a r p b a n d a t 687 cm i n (m-PCgH^PS)^ i s b e l i e v e d t o be due t o t h e same v i b r a t i o n . Raman b a n d s a t 4 6 7 , 440 and 354 cm""1 i n Ph,,P,S_ 5 5 5 _ A a p p e a r t o c o r r e l a t e w i t h b a n d s a t 4 5 2 , 433 a n d 340 cm cm -1 i n (jD-FCgH^PS) 3 » The v i b r a t i o n a p p e a r i n g a t 467 i n P h ^ P ^ S ^ may be t h e P - s e n s . ( t ) v i b r a t i o n b u t i t a p p e a r s t o be r a t h e r t o o s t r o n g b y c o m p a r i s o n w i t h o t h e r s p e c t r a ; _ A e i t h e r t h i s b a n d , o r t h a t a t 511 cm , i s l i k e l y t o be due t o t h e P-P s t r e t c h i n g v i b r a t i o n . The s t r o n g v i b r a t i o n s a t _ -I 440 a n d 354 cm i n t h e Raman s p e c t r u m o f P h ^ P ^ S ^ , a n d TABLE X I V VIBRATI O N A L SPECTRA OF P h , P , S , AND I T S FLUOROPHENYL ANALOGUES P h 3 P 3 S 3 I . RAMAN SPECTRA (p_-PC 6H 4PS) 3 FREQUENCY R E L A T I V E ASSIGNMENT FREQUENCY R E L A T I V E ASSIGNMENT ( c m " 1 ) I N T E N S I T Y ( c m " 1 ) I N T E N S I T Y 714 1.1 682 8.0 P - s e n s . ( r ) 655 3.4 V(P=S) 675 8.0 V(P=S) 619 1.5 619 4.1 511 3.7 s e e t e x t 499 1.8 467 5.5 P - s e n s . ( t ) o r l ^ ( P - P ) 452p 8.0 440 4.9 s e e t e x t 433p 10 s e e t e x t 405 1.1 413p 4.6 378 1.9 401 1.7 354 10 s e e t e x t 340p 9.8 s e e t e x t 317 4.3 315 2.8 289 3.1 304 4.3 270 1.9 294 1.9 242 2.0 257 2.9 218 2.2 242 2.3 p = p o l a r i z e d ( c o n t i n u e d o v e r l e a f ) - 1 6 1 -TABLE X I V ( c o n t . ) I I . INFRARED SPECTRA* ( p _ - F C 6 H 4 P S ) 5 ( m - F C 6 H 4 P S ) 3 FREQUENCY R E L A T I V E ASSIGNMENT FREQUENCY R E L A T I V E ASSIGNMENT ( c m - 1 ) I N T E N S I T Y (cm-') I N T E N S I T Y 702 w 687 s s e e t e x t 673 v s y ( P = S ) 646 s V (P=S) 6 1 5 , 6 1 1 m 555 m 522 ms 517 m 504 ms 507 m 492 ms 488 s 444 ms 466 s 422 mw 4 3 8 , 4 3 2 m 405 w 371 m 365 w 3 1 1 w 338 w 256 w 325 w P h 3 P 3 S 3 FREQUENCY R E L A T I V E ASSIGNMENT ( c m - 1 ) I N T E N S I T Y 710 s s e e t e x t 648 v s y ( P = S ) 610 w 504 m 478 m 4 6 8 , 4 6 2 ms 430 w 395 w v = v e r y ; w=weak; m=medium; s = s t r o n g * i n c l u d e s a b s o r p t i o n s l i s t e d i n T a b l e I V - 1 6 2 -_-1 t h o s e a t 4 3 3 a n d 3 4 0 cm i n t h e R a m a n s p e c t r u m o f ( p ^ - F C g H ^ P S ) ^ a r e b e l i e v e d t o b e d u e t o s t r e t c h i n g v i b r a -t i o n s o f t h e P ^ S p r i n g . T n e i n t e n s i t y o f t h e s e a b s o r p t i o n s e s s e n t i a l l y e l i m i n a t e s t h e p o s s i b i l i t y t h a t t h e y m a y b e d u e t o v i b r a t i o n s w i t h i n t h e p h e n y l r i n g s . T o s u b s t a n t i a t e t h e a r g u m e n t t h a t t h e s e v i b r a t i o n s a r e d u e t o t h e P^S,., r i n g , i t i s w o r t h n o t i n g t h e f o l l o w i n g p o i n t s : ( i ) • P 4 S 3 » c o n t a i n i n g t h r e e f u s e d P ^ S p r i n g s , h a s R a m a n _ -i a b s o r p t i o n a t 4 4 3 a n d 3 4 2 cm ; t h e s e t w o b a n d s a r e t h e s t r o n g e s t o b s e r v e d f o r ^ / ^ ^ a n d . a r e t h o u g h t t o b e s y m m e t r i c a n d a n t i s y m m e t r i c P-S s t r e t c h i n g r e -s p e c t i v e l y . ( i i ) P ^ S 7 , c o n t a i n i n g t w o f u s e d P ^ S p r i n g s , h a s v e r y s t r o n g R a m a n a b s o r p t i o n a t 3 4 6 c m - a n d s t r o n g a b s o r p t i o n a t 4 4 4 cm ( i i i ) P 4 S 5 , c o n t a i n i n g t w o f u s e d P-^Sp r i n g s , h a s s t r o n g ^ ft — 1 a b s o r p t i o n a t 3 8 8 c m " a n d s t r o n g b a n d s a t b o t h 4 3 4 a n d 4 5 2 c m " " 1 . 85 T h e s u g g e s t i o n b y B a u d l e r et a l . t h a t t h e r e g i o n 5 5 0 - 6 0 0 c m " 1 i s t y p i c a l o f P-S s t r e t c h i n g i s n o t j u s t i f i e d a n d t h e l a c k o f a b s o r p t i o n b y P h ^ P ^ S ^ i n t h i s r e g i o n c a n n o t b e c o n s i d e r e d a s e v i d e n c e t h m e m b e r e d p h o s p h o r u s r i n g . t h a t P h , P , S , c o n s i s t s o f a t h r e e -5 5 5 - 1 6 3 -The F l u o r o p h e n y l C y c l o p o l y p h o s p h i n e s ( F C g H ^ P ^ The mass s p e c t r a o f t h e f l u o r o p h e n y l c y c l o p o l y p h o s -p h i n e s a r e p r e s e n t e d i n T a b l e XV. T h e s e r e s u l t s i n d i -c a t e t h a t ( m - F C g H 4 P ) n m o s t l i k e l y h a s a p e n t a m e r i c s t r u c t u r e , w h e r e a s ( p _ - F C g H 4 P ) n p r o b a b l y h a s a h e x a m e r i c s t r u c t u r e . P e a k s a r e s e e n a t a l l v a l u e s o f n = 1-5 f o r ( m - F C g H 4 P ) n a n d t h e r e a p p e a r s t o be no r e a s o n why t h e n = 6 s p e c i e s s h o u l d n o t a l s o a p p e a r i f i t w e r e t h e p a r e n t i o n . On t h e o t h e r h a n d , t h e a b u n d a n c e o f t h e ( F C g H " 4 P ) g + i o n i s g r e a t e r t h a n t h a t o f t h e (FCgH^P)^"*" i o n i n t h e mass s p e c t r u m o f ( p _ - F C g H 4 P ) n , s u g g e s t i n g t h a t t h e f o r m e r p e a k i s t h e p a r e n t i o n . The mass s p e c t r u m o f (p_-FCgR" 4P) n i s much more c o m p l e x t h a n t h a t o f ( m - F C g H 4 P ) n a n d s e v e r a l h i g h m o l e c u l a r w e i g h t f r a g m e n t s c a n o n l y be e x p l a i n e d i f i t i s a s s u m e d t h a t a p h e n y l g r o u p h a s b r o k e n u p . The i n f r a r e d a n d Raman s p e c t r a o f ( p _ - F C g H 4 P ) n h a v e b e e n o b -t a i n e d ; i n t h e i n f r a r e d s p e c t r u m , t h e s t r o n g e s t b a n d s a r e due t o t h e f l u o r o p h e n y l g r o u p s , w h i l s t i n t h e Raman s p e c -_ -i t r u m , a v e r y s t r o n g b a n d a t 476 cm i s t h e o n l y i n t e n s e b a n d i n t h a t r e g i o n a n d i s t h e r e f o r e c o n f i d e n t l y a s s i g n e d a s P-P s t r e t c h i n g . - 1 6 4 -TABLE XV MASS SPECTRA OF COMPOUNDS ( F C 6 H 4 P ) n ( £ - F C 6 H 4 P ) n ( m - F C . 6 H 4 P ) n PEAK ABUNDANCE A S S I G N M E N T ^ PEAK ABUNDANCE ASSIGNMENT (m/e) (m/e) 756 17 ( F C 6 H 4 P ) 6 630 14 ( F C 6 H 4 P ) 5 630 4 ( F C 6 H 4 P ) 5 535 24 ( P C 6 H 4 ) 4 P 5 504 42 < F C 6 H 4 P ) 4 504 2 ( F C 6 H 4 P ) 4 485 16 ( F C 6 H 4 ) 3 P 4 ( C 6 H 4 ) 471 19 F C 6 H 5 P 6 ? 456 21 ? 442 31 ( F C 6 H 4 ) 4 P 2 414 20 ? 409 18 ( F C 6 H 4 } 3 P 4 378 26 ( F C 6 H 4 P ) 3 378 77 ( F C 6 H 4 P ) 3 327 25 ? 316 100 ( F C 6 H 4 ) 3 P 316 100 ( F C 6 H 4 ) 3 P 252 22 ( F C 6 H 4 P ) 2 252 30 ( F C 6 H 4 P ) 221 97 ( F C 6 H 4 ) 2 P 221 69 ( F G 6 H 4 ) 2 219 62 ( F C 6 H 3 ) 2 P 219 51 ( F G 6 H 3 ) 2 : 201 35 ( F C 6 H 3 ) P ( G 6 H 4 ) 201 25 ( F C 6 H 3 ) P ( C 6 H 4 187 41 F C 6 H 3 P 3 ? 157 33 P G 6 H 4 P 2 157 32 F C 6 H 4 P 2 135 31 ? 126 92 F C 6 H 4 P -165-ELECTRONIC INTERACTIONS OF THE FLUOROPHENYL DERIVATIVES The sensitivity of the shielding of fluorine to small changes in molecular environment i s well-known, and for many groups the interpretation of the fluorine chemical shifts of m-fluorophenyl and p_-f luorophenyl derivatives in terms of 77"-electron densities has been 137—139 j u s t i f i e d theoretically and the shielding para-RD meters correlated with the Taft reactivity parameters 1 23 CTj and <3~Ro. More recently , i t has been found that there is a good correlation between CT^ o and £ Aq^TT"), as obtained from CNDO/2 calculations, so verifying that (T^o i s a measure of 77-charge transfer and hence of conjugative interactions. The parameters have also been shown to be applicable to substitution at a phosphorus 71 centre' . 19 The F chemical shifts of the fluorophenyl deriva-tives prepared in this work, and the calculated inductive and resonance parameters, have been presented i n Table II. Related data for previously reported compounds are l i s t e d in Table XVI and w i l l be used for comparison purposes. The results for the fluorophenyl cyclopolyphosphines are of great interest because several variables, such as the oxidation state of phosphorus and the presence of sulphur, are eliminated. Unfortunately, the para-fluorophenyl cyclopolyphosphine was too insoluble to obtain a fluorine n.m.r. spectrum; however, the pentafluorophenyl cyclopoly-TABLE X V I SHIE L D I N G PARAMETERS a AND TAFT INDUCTIVE AND RESONANCE PARAMETERS COMPOUND S(m-F) S(p_-F) CTj CT Ro REFERENCE F C 6 H 4 P ( C 6 H 5 ) 2 -0.9 -0.7 +0.21 -0 . 0 1 97,98 ( F C 6 H 4 ) 3 P -1.3 -1.2 +0.27 ~o 97,98 F C 6 H 4 P ( S ) ( C 6 H 5 ) 2 -2.2 -5.5 +0.39 +0.16 97,98 ( F C 6 H 4 ) 3 P = S — -4.8 — — 97 F C 6 H 4 P F 4 -2.6 - 1 2 . 1 +0.45 +0.32 71 F C 6 H 4 P F 2 - 2 . 1 -8.3 +0.38 +0.21 71 F C 6 H A P n F 2 n - l -3.3 -10.2 +0.56 +0.20 146 F C 6 H 4 B r - 2 . 5 5 + 2.55 +0.44 -0.16 80 F C 6 H 4 F -3.10 +6.40 +0.52 -0.32 80 a . u s i n g d i l u t e s o l u t i o n s w i t h C^-H^F a s i n t e r n a l s t a n d a r d - 1 6 7 -p h o s p h i n e , ( C g F ^ P ) ^ , h a s b e e n e x a m i n e d b y C o w l e y a n d P i n n e l l 1 4 0 who r e p o r t t h a t " t h e 7 7 " - b o n d i n g s i t u a t i o n i n ( C g F f J ? ) ^ w o u l d a p p e a r t o be a b o u t t h e same a s i n C 6 P 5 P ( C g H 5 ) 2 i n t e r m s o f t h e p u b l i s h e d r e l a t i o n s h i p s 1 4 1 * 14-2 19 b e t w e e n t h e c h e m i c a l s h i f t o f t h e p a r a F r e s o n a n c e and 7 7 - b o n d i n g i n p e n t a f l u o r o p h e n y l p h o s p h i n e d e r i v a t i v e s . " I t m i g h t be e x p e c t e d , t h e r e f o r e , t h a t t h e i n d u c t i v e a n d c o n j u g a t i v e e f f e c t s i n t h e m o n o f l u o r o p h e n y l c y c l o p o l y -p h o s p h i n e s w i l l r e s e m b l e t h o s e i n t h e m o n o f l u o r o p h e n y l -d i p h e n y l p h o s p h i n e s ; i n f a c t , t h e 0~j v a l u e o f m - F C g H 4 P ( C g H ^ ) 2 i s +0.21 w h e r e a s t h e a v e r a g e CJ^ v a l u e o f ( m - P C g H 4 P ) n i s +0.29. Much o f t h i s d i f f e r e n c e c a n be a t t r i b u t e d t o t h e p r e s e n c e o f more t h a n one f l u o r o p h e n y l g r o u p ; t h e e f f e c t o f a d d i t i o n a l f l u o r o p h e n y l g r o u p s c a n be s e e n b y c o m p a r i n g t h e CTj v a l u e s o f m-FCgH^PCCgH^)^ and ( m - F C g H ^ P , +0.21 a n d +0.27 r e s p e c t i v e l y ( T a b l e X V I ) . The o b s e r v e d d i f f e r e n c e o f +0.06 i s l i k e l y g r e a t e r t h a n t h e d i f f e r e n c e t h a t w o u l d be e x p e c t e d f o r m - F C g H 4 P ( C g H ^ ) n _ 1 w i t h r e s p e c t t o ( m - F C g H 4 P ) n , s i n c e t h e l a t t e r compound h a s o n l y one f l u o r o p h e n y l g r o u p p e r p h o s p h o r u s a t o m . N o n e t h e l e s s , i t i s a p p a r e n t t h a t i n d u c t i v e e f f e c t s i n ( m - F C 6 H 4 P ) n and m-FCgH^Pt CgH,^) 2 a r e i n d e e d s i m i l a r . T h e r e a r e s e v e r a l p o s s i b l e e x p l a n a t i o n s f o r t h e a p p e a r a n c e o f two f l u o r i n e r e s o n a n c e s i n t h e n.m.r. s p e c t r u m o f ( m - F C g H 4 P ) n : p e r h a p s t h e m o s t l i k e l y i s t h a t two d i f f e r e n t -168-r i n g s i z e s a r e p r e s e n t i n s o l u t i o n ; t h e e x i s t e n c e o f s e v e r a l r i n g s i z e s h a s b e e n n o t e d f o r t h e p h e n y l c y c l o -134 p o l y p h o s p h i n e , p e n t a f l u o r o p h e n y l c y c l o p o l y p o l y p h o s p h i n e 1 4 0 and t r i f l u o r o m e t h y l c y c l o p o l y p h o s p h i n e 1 4 5 s y s t e m s . On t h e o t h e r h a n d , t h e mass s p e c t r u m o f ( m - F C g H ^ P ) n s u g g e s t s t h a t t h i s compound c o n s i s t s o f a f i v e - m e m b e r e d r i n g i n t h e s o l i d s t a t e ; t h e a n a l o g o u s compound ( P C F ^ ) ^ e x h i b i t s two C F ^ m u l t i p l e t s i n i t s ? F n.m.r. s p e c t r u m and t h i s h a s b e e n a t t r i b u t e d 1 4 5 t o p s e u d o - r o t a t i o n , a c y c l i c i n t e r c h a n g e o f t h e r o l e o f t h e P a t o m s , a n d h e n c e o f t h e GF^ g r o u p s , a r o u n d t h e r i n g t h r o u g h a t o r s i o n a l v i b r a t i o n . P s e u d o - r o t a t i o n m i g h t w e l l o c c u r i n ( m - F C g H 4 P ) n i f t h i s compound d o e s c o n t a i n a P^ r i n g i n s o l u t i o n . S i n c e no 5 P n.m.r. s p e c t r u m c o u l d be o b t a i n e d f o r ( g - F C g H ^ P ) ^ t h e c o n j u g a t i v e i n t e r a c t i o n s w i t h i n t h e c y c l o p o l y p h o s p h i n e r i n g h a v e b e e n i n f e r r e d b y u s i n g C o w l e y ' s s t a t e m e n t 1 4 ^ * t h a t 7 7 - b o n d i n g i s s i m i l a r t o t h a t o b s e r v e d i n C g F ^ P ( C g H ^ ) 2 . The T a f t r e s o n a n c e p a r a m e t e r , ^ R 0 , f ° r t h e a n a l o g o u s p a r a - f l u o r o p h e n y l d e r i v a t i v e , £ - F G g H 4 P ( C g H ^ ) 2 , i s -0.01, i n d i c a t i n g t h a t t h e P ( C g H ^ ) 2 m o i e t y i s a weak, b u t n e t 7 7 - d o n o r t o i t s a t t a c h e d f l u o r o p h e n y l g r o u p . T h e r e f o r e , t h e p h o s p h o r u s r i n g i n p h e n y l c y c l o p o l y p h o s p h i n e s i s a p p a r e n t l y a weak 7 7 - d o n o r t o i t s a t t a c h e d p h e n y l r i n g s . The m a g n i t u d e o f 0~ Ro i s so s m a l l i n jD-FCgH^PtCgH^) 2 t h a t i t i s e n t i r e l y p o s s i b l e t h a t t h e c y c l o p o l y p h o s p h i n e r i n g may be a weak 7 7 - a c c e p t o r ; h o w e v e r , t h e r e w i l l o b v i o u s l y n o t be a g r e a t t r a n s f e r o f 7 7 - d e n s i t y b e t w e e n t h e p h e n y l - 1 6 9 -r i n g s and t h e s k e l e t a l p h o s p h o r u s r i n g . I n P h ^ P ^ S , a f i v e - m e m b e r e d r i n g i s a g a i n p r e s e n t e x c e p t t h a t one PhP g r o u p i n g h a s b e e n r e p l a c e d b y s u l p h u r . N o t s u r p r i s i n g l y , t h e s u b s t i t u t i o n o f one s u l p h u r w i t h i n t h e r i n g d o e s n o t p r o d u c e d r a s t i c c h a n g e s . The i n d u c t i v e a n d r e s o n a n c e p a r a m e t e r s o f t h e P^S s k e l e t o n a r e +0.26 ( a v g . ) a n d - 0 . 0 2 , r e s p e c t i v e l y , v e r y c l o s e t o t h o s e o f F G 6 H 4 P ( C 6 H 5 ) 2 ( + 0 . 2 1 an d - 0 . 0 1 r e s p e c t i v e l y ) , b e a r i n g i n m i n d t h e l i k e l y e f f e c t s o f t h e p r e s e n c e o f a d d i t i o n a l f l u o r o p h e n y l g r o u p s . The P^S r i n g i s t h u s a weak TT-donor t o i t s a t t a c h e d f l u o r o p h e n y l g r o u p s ; i n f a c t , i t m u s t be c o n s i d e r e d t o be a s t r o n g e r TT - d o n o r t h a n t h e s e r e s u l t s i n d i c a t e b e c a u s e o f t h e p r e s e n c e o f f o u r f l u o r o p h e n y l g r o u p s . F l u o r i n e i t s e l f i s known t o be a r e a s o n a b l e 77-8 0 d o n o r , s o t h a t t h e 7 7-donor c a p a c i t y o f t h e P^S r i n g i s s u f f i c i e n t t o o u t w e i g h t h e c o m b i n e d e f f e c t s o f t h e f o u r f l u o r i n e a t o m s . The movement o f e l e c t r o n i c d e n s i t y w i t h i n t h e P^S r i n g i s t h e r e f o r e v e r y s i m i l a r t o t h a t i n f e r r e d f o r t h e c y c l o p o l y p h o s p h i n e s y s t e m . The a d d i t i o n o f s u l p h u r t o Ph^P^ S r e s u l t s i n f o r m a -t i o n o f P h ^ P ^ S ^ an d t h e P 3 S 2 r i n g f o u n d i n t h i s compound i s a c h a r a c t e r i s t i c f e a t u r e o f many o t h e r p h o s p h o r u s -s u l p h u r c o m p o u n d s . I t i s a p p a r e n t f r o m t h e r e s u l t s l i s t e d i n T a b l e I I t h a t t h i s a d d i t i o n o f s u l p h u r r e s u l t s i n s i g -n i f i c a n t c h a n g e s i n b o t h t h e i n d u c t i v e a n d r e s o n a n c e - 1 7 0 -p a r a m e t e r s . The m o s t d e s h i e l d e d f l u o r i n e atom' i n "both t h e m e t a -an d p a r a - d e r i v a t i v e s i s c o n s i d e r e d t o be i n t h e f l u o r o -p h e n y l g r o u p a t t a c h e d t o t h e p e n t a v a l e n t p h o s p h o r u s a t o m . The r e m a i n i n g two f l u o r i n e a t o m s c a n n o t be d i s t i n g u i s h e d i n t h e s p e c t r u m o f ( m - F C g H ^ P S ) ^ b u t a r e c l e a r l y n o n -e q u i v a l e n t i n t h e s p e c t r u m o f (jD-FCgH^PS) ^ . T a b l e I I i l l u s t r a t e s t h a t i n d u c t i v e w i t h d r a w a l f r o m t h e f l u o r o -p h e n y l g r o u p s i s r e l a t i v e l y i n s e n s i t i v e t o t h e o x i d a t i o n s t a t e o f p h o s p h o r u s , e v e n t h o u g h c o n j u g a t i v e w i t h d r a w a l i s o b v i o u s l y v e r y s e n s i t i v e t o t h i s p a r a m e t e r . The c o n -s t a n c y o f CT s u g g e s t s t h a t , e i t h e r t h e r e e x i s t s v e r y e f f i c i e n t i n d u c t i v e t r a n s m i s s i o n t h r o u g h o u t t h e r i n g , o r t h a t t h e p r e s e n c e o f s u l p h u r p l a y s t h e m a j o r r o l e i n c a u s i n g i n d u c t i v e w i t h d r a w a l . The m a g n i t u d e o f t h i s w i t h -d r a w a l i s s u r p r i s i n g l y l a r g e , a p p r o x i m a t i n g t h a t o f a 8 0 b r o m i n e s u b s t i t u e n t ; i n f a c t t h e (Jj v a l u e s o f t h e f l u o -r o p h e n y l g r o u p s a t t a c h e d t o t h e t r i v a l e n t p h o s p h o r u s a t o m s a l m o s t r i v a l t h e <J^ v a l u e f o u n d f o r m - FCgH^PClp. The C J R o p a r a m e t e r s r e v e a l t h a t 7 7 - e l e c t r o n d e n s i t y i s w i t h -d r a w n f r o m a l l t h e f l u o r o p h e n y l g r o u p s , b u t t o a v a r y i n g d e g r e e . As s t a t e d p r e v i o u s l y , t h e l a r g e s t w i t h d r a w a l i s c o n s i d e r e d t o be f r o m t h e f l u o r o p h e n y l g r o u p a t t a c h e d t o t h e p e n t a v a l e n t p h o s p h o r u s ; t h e v a l u e o f 0" Ro o f +0.14 i s v e r y s i m i l a r t o t h a t o b t a i n e d f o r m- a n d p_-FCgH^P(S)(CgH^) ( T a b l e X V I ) . F u r t h e r , t h e d i f f e r e n c e i n ( T o b e t w e e n t h e - 1 7 1 -T A BLE X V I I EFFECT OF FLUORINE I N THE p a r a - P O S I T I O N ON VARIOUS INFRARED STRETCHING FREQUENCIES COMPOUND V(P-I)(cm-1) P h 2 P 2 I 2 337 ( m - F C 6 H 4 P I ) 2 340 ( £ - P C 6 H 4 P I ) 2 366 COMPOUND V ( P = S ) ( c m " 1 ) P h 5 P 3 S 5 648 ( m - F C 6 H 4 P S ) 3 646 ( £ - F C 6 H 4 P S ) 3 673 COMPOUND V ( P = S ) ( c n T 1 ) Ph 2P 2 s 4 ( m - F C 6 H 4 P S 2 ) 2 ( £ - F C 6 H 4 P S 2 ) 2 655 652 687 -172-PC 6H 4P(C 6H 5) 2 and FCgH^PCS)(C 6H 5) 2 systems is very close to the difference in C*"Ro observed between the pentavalent phosphorus atom in the (FCgH^PS)^ system and the trivalent phosphorus atoms in the (FCgH^P^S system. An examination of the P=S infrared stretching frequencies (Table XVII) reveals that the P=S bond i s strengthened significantly i n (jD-FCgH^PS)^, suggesting that at least part of the 77-electron density withdrawn from the fluorophenyl group (attached to the pentavalent phosphorus) is transferred to the P=S bond via 77-donor action from fluorine i t s e l f , and not just from the benzene TT-system. Note that the P=S stretching frequency of (m-FCgH^PS)^, i n which conjugative interaction with fluorine i s not possible, i s essentially unchanged from that of Ph^P^S^. Knox e_t a l 1 4 4 studied the meta- and para- substituted derivatives of XC6H4Fe(CO) U=MeO, Me, F, Cl, C02Me, CN) and found a linear correlation between the Hammett ( J -constants and the symmetric and antisymmetric infrared stretching frequencies of the CO groups. However, the changes in these frequencies were small, ^^^j^ - 15 cm-1 and b\V = 12 cm - 1. Stewart and T r e i c h e l 1 o n the sym. * other hand, prepared the series meta- and para-XC6H4Mn(CO)5 (X=H, F, Cl, Br, CN, CF^) and found that the CO vibrations were practically invariant to both the nature of the substituent X and to i t s position on the ring; these authors suggest that the larger effects observed by -173-Knox et al'.*'* probably result from the presence of only two CO groups (vs. five i n the manganese compounds) i n that these two carbonyls would be forced to respond to a greater extent and appear more sensitive to the net electron den-sity change. By contrast, the difference in the P=S stretching frequencies of m- and (p_-FCgH4PS)^ i s 27 cm , much larger than the frequency change for the CO vibra-tions. It appears that other workers have not noticed the effect of 77-donation from fluorine as distinct from donation from the benzene 77-system, perhaps because the effects are usually small; with such highly polarizable bonds as P=S and P-I, the effects are more readily seen. The main conclusion that should be made from these obser-vations i s that conjugative interactions with a p_-fluoro-phenyl group reflect the combined effects of the donor-acceptor properties of the benzene 77-system and the 77-donor properties of fluorine, an extension and modifi-8 0 cation of the original concepts . Substituents X (in Pj-FCgH^X compounds) which exhibit 77-donor properties with respect to the fluorophenyl group are thus stronger donors than otherwise appears in that their 77-donor capabilities must i n i t i a l l y counteract the 77-donor action of fluorine. Similarly, a substituent X (in CgH^X comp-ounds) may actually be a weak 77-donor but appear from n.m.r. chemical shifts (in FCgH^X compounds) to act as a weak 77-acceptor i f i t s 77-donor capabilities are less than those of fluorine. It i s important to keep these effects - 1 7 4 -i n mind when i n t e r p r e t i n g the c o n j u g a t i v e i n t e r a c t i o n s o f f l u o r o p h e n y l d e r i v a t i v e s , s i n c e i t i s v i r t u a l l y i m p o s s i b l e t o d i s t i n g u i s h between donor a c t i v i t y from the benzene 7 7 -system and from f l u o r i n e 7 7 - o r b i t a l s . A comparison o f the r e s u l t s o b t a i n e d w i t h monofluoro-8 0 phenyl systems t o those o b t a i n e d w i t h p e n t a f l u o r o p h e n y l 1 4? systems r e i n f o r c e s the i d e a s p r e s e n t e d above. A c c o r d -8 0 i n g t o T a f t e t a l . , the halogens are e s s e n t i a l l y weak 7 7 -donors w i t h C J R o v a l u e s becoming more n e g a t i v e i n the s e r i e s H < I < CH"5 < Br < C l < P. However, a c c o r d i n g t o 1 42 Graham e t a l l who used p e n t a f l u o r o p h e n y l d e r i v a t i v e s , the o r d e r o f 77-donor s t r e n g t h i s I < H < Br < C l < CH^ < E so t h a t w i t h the e x c e p t i o n o f f l u o r i n e , they might be c o n s i d e r e d as 7 7 - a c c e p t o r s . A l o g i c a l e x p l a n a t i o n o f t h i s d i f f e r e n c e i s t h a t i n the p e n t a f l u o r o p h e n y l systems, CgF^X, t h e r e are t h r e e f l u o r i n e atoms capable o f d o n a t i n g 7 7 - e l e c t r o n d e n s i t y i n a c o n j u g a t i v e manner t o the sub-s t i t u e n t X. Here, then, i s an i l l u s t r a t i o n o f the p o i n t t h a t was made above: the combined a c t i o n o f 7 7 - d o n a t i o n from t h r e e f l u o r i n e atoms changes the s u b s t i t u e n t X from b e i n g a weak 77-donor to b e i n g a weak 7 7 - a c c e p t o r . Of course, the e f f e c t o f i n d u c t i v e withdrawal by the CgF^ group would enable s u b s t i t u e n t X t o s u c c e s s f u l l y compete f o r 7 7 - e l e c t r o n d e n s i t y and cannot be o v e r l o o k e d . In a l l f a i r n e s s though, i t can be s t a t e d t h a t the magnitude o f don o r - a c c e p t o r i n t e r a c t i o n s w i l l be exaggerated i f one -175-uses pentafluorophenyl derivatives instead of monofluoro-phenyl derivatives. The fluorine chemical shift of para-fluorophenyl species, ^-FCgH^X, w i l l therefore depend not only on the a b i l i t y of substituent X to receive or donate 77-charge, but w i l l also depend, to a certain degree, on the inherent 77-donor a b i l i t y of fluorine. This 77-donor a b i l i t y of fluorine would be expected to remain f a i r l y constant as long as the para- substituent X i s capable of 77-inter-actions (excluding X=H, for example) so that the compari-sons that have been made, and w i l l be made, remain valid. Even though the magnitude of the values may not be completely accurate in that they should probably be made somewhat more negative, the trends observed within a series w i l l not be affected. Let us consider once again the 77-interactions within the (FCgH^PS^ system. As pointed out by Taft et a l ? 1 , p77-acceptor interaction by phosphorus i s greatly dimin-ished when the phosphorus i s tetracoordinate, because p-orbitals are largely involved in CT-bond formation; con-sequently, the predominant acceptor interaction w i l l involve use of d orbitals on phosphorus. It i s apparent, therefore, that the P=S bond in (jD-FCgH^PS).^ i s strength-ened by enhanced d77- p77 bonding between P and S, or possibly by d77 - d77 bonding. Conjugative withdrawal -176-frora the fluorophenyl groups attached to the trivalent phosphorus atoms is slight, hut d i s t i n c t l y different from the effects observed in the P^ S ring. It i s d i f f i c u l t to determine whether this 77-electron density i s transferred to sulphur, or whether i t remains with phosphorus to comp-ensate for the accumulation of positive charge resulting from inductive withdrawal by sulphur. In a l l probability, the true bonding picture l i e s somewhere between these extremes. Addition of sulphur to Ph^P^S^ results in a struct-ural change to PhpPpS^, a four-membered ? 2 S 2 r;i-nS» T n e fluorophenyl derivatives of this compound are exceptional in that they exhibit both strong inductive and conjugative withdrawal. The presence of only two fluorophenyl groups in this molecule ensures that the effects of one on the other w i l l be lowered and that the results obtained reflect accurately the various interactions within the I^S^ f r a m e ~ work. Inductive withdrawal from the fluorophenyl groups i s extremely large and the value of CTj (+0.58) is of the same order of magnitude as those found for such strong <X-acceptors as P (+0.52) and N02 (+0.56). Conjugative with-drawal i s also strong and the magnitude of CTRo (+0.20) i s similar to the values found for such strong 7T-acceptors as CN and N02, +0.21 and +0.20 respectively. From Table XVI, i t i s apparent that the value of CJRo in the (FCgH 4PS 2) 2 system i s not greatly different from the CTRo -177-values of other compounds in which phosphorus i s penta-valent and tetracoordinate. Again, the P=S bond i s ob-served to be strengthened (Table XVII) in the p_-fluoro-phenyl derivative; the m-fluorophenyl derivative exhibits a P=S stretching frequency at essentially the same fre-quency as i t s phenyl analogue, confirming that the P=S bond in (jo-FCgH^PS,,) 2 ^ s strengthened (with respect to PhpPpS^) by way of conjugative interaction with fluorine. At the same time, i t i s important to note that the P=S stretching frequency in PhgPpS^ (655 cm" ) occurs at a much higher frequency than in MegPpS^ (617 cm- ), i l l u s -trating the importance of donation from the benzene 77-system. Since both phosphorus atoms in PhpPpS^ are equiv-alent and are tetracoordinate, 77-acceptor act i v i t y at phosphorus must involve population of d orbitals for the reasons outlined previously. The a b i l i t y of pentavalent phosphorus to act as a 77-acceptor has been noted by several workers1 * * and the value of <TRo obtained for the (FCgH^PSp^ system appears to be a typical value. As might be expected, larger values of CTRo have been ob-tained (Table XVI) for the FCgH^PF^ system and also for the monofluorophenyl phosphonitrilic fluoride (FCgH 4P nN nF n A) system. The very large acceptor properties of the P 2 S4 framework i s confirmed by the proton chemical shift of MepPjjS^, which i s centred at the low value of 14-7 7.50 T. By comparison, the proton chemical shift of m ethyl heptafluorocyclotetraphosphonitrile, N^P^F^Me, i s -178-centred at 8.30 7. In addition, the following proton chem-1 4.8 i c a l shifts have been reported by Nixon and Schmutzler : MePF4, 8.12 7; MeP(0)Cl 2, 7.72 7; MeP(S)Cl 2, 7.12 7. It i s thus readily apparent that the proton chemical sh i f t of Me 2P 2S 4 i s rather low. The inductive and resonance parameters obtained for the (FCgH"4PI)2 system are +0.35 and +0.15 respectively. Inductive withdrawal is intermediate between that observed for (m-FCgH4P)4S and (m-FCgH^PS)^; conjugative withdrawal i s also of moderate intensity and the effect of the p_-fluorophenyl gro-up serves to strengthen the P-I bond con-siderably (Table XVII), again showing that a bond order i s raised via conjugative interaction with fluorine. The P-I stretching frequency of (m-FCgH4PI)2 i s essentially unchanged from the value obtained for Ph 2P 2I 2. The effects of the substitution of sulphur into phosphorus ring systems are readily apparent from the n.m.r. results that have been presented i n this section. It has been inferred that the phosphorus ring i n phenyl cyclopolyphosphine i s a weak 77-donor to i t s attached phenyl rings. Replacement of one PhP group with sulphur does not produce a great change and the P^S ring i s also a weak 77-donor to i t s attached phenyl groups. The presence of additional sulphur, as in Ph^P^S^, results i n moderate, but disproportionately large, inductive with-drawal and weak to moderate conjugative withdrawal from - 1 7 9 -the phenyl rings. Finally, i n PhgP^S^, the compound with the highest S/P ratio, the acceptor properties of the P 2S^ framework are very large. It i s thus readily appa-rent that the presence of sulphur and pentavalent phos-phorus must necessarily play crucial roles in the explana-tion of these observations. The trend that acceptor pro-perties of P-S compounds increase with increasing sulphur content was also noted for the cage phosphorus sulphides. The d R o values of the organophosphorus sulphur rings cannot be considered exceptional; on the other hand the (Jj values of the (FCgH^PS)^ and (FCgH^PS^ systems are larger than would be otherwise expected, and an adequate explanation of these features must await further experi-mentation. -180-SUMMARY: It i s worthwhile, by way of summary, to note some of the similarities and differences in the reactions and properties of the ring and cage phosphorus sulphides. Consider f i r s t the various ways of preparing these types of compounds; for example, both types can he prepared by the reactions of phosphines with sulphur. Phosphine i t -121 self w i l l react with sulphur to produce a mixture of phosphorus sulphides, the major components depending on the stoichiometry of the reactants. The results pre-sented in this thesis, together with the earlier work of Maier, have shown that monosubstituted phosphines are capable of similar reactions to yield ring P-S compounds; again, the end products depend upon the stoichiometry of the reactants. Another obvious similarity between the ring and cage P-S compounds i s that the higher sulphides can be pre-pared by the reaction of a lower sulphide with sulphur. It has been mentioned previously that P^Sj. i s best pre-21 pared by the reaction of P ^ S ^ with elemental sulphur; 134 i n addition, Mai has shown that and P ^ S ^ Q can be conveniently prepared from P ^ S ^ and sulphur. Similarly, 82 Maier has shown that both Ph^P^S^ and PhpPpS/j. °an be prepared by the reaction of Ph^P^S with sulphur. The mobility of bonding in P-S compounds has been il l u s t r a t e d several times i n this thesis. A typical example of this -181-mobility i s that, for the ring compounds, the last-mentioned reactions are reversible; that i s , Ph^P^S can "be prepared from both Ph^P^S^ and PhgPpS^ by the removal of sulphur with mercury, the reactions involving considerable re-arrangement of skeletal structures. Limited work of this type has been performed with the cage phosphorus sulphides; in fact, i t would appear that the only reaction examined is that of with triphenylphosphine, reported i n this thesis. Part of the sulphur was successfully removed and i t would be expected that removal of sulphur, partic-ularly the exocyclic sulphur atoms, from the higher sul-phides such as P4 S5» P4 S7 a n d • P4 Slo w o u- 1- d *>e m u ° h easier. An investigation of these reactions would be of interest, not only with a view to expanding our knowledge of the chemistry of the phosphorus sulphides, but also because careful removal of sulphur from the higher sulphides might result i n formation of new cage compounds. 21 Treadwell and Beeli have observed that, with an excess of iodine, P 4 S 2 i s oxidized to J^S^. The oxi-dation of a lower sulphide to a higher sulphide by iodine has also been observed with the P-S ring compounds, namely the oxidation of P h ^ S ^ to PhgP^. By contrast, the lowest ring sulphide, PI14P4S, again behaves more li k e a cyclopolyphosphine and undergoes ring cleavage when i t reacts with iodine. -182-Finally, the use of fluorophenyl groups to assess electronic interactions within the P-S ring compounds has il l u s t r a t e d that acceptor properties are greatest in those compounds richest in sulphur and pentavalent phosphorus; in particular, the acceptor properties of the ?2 S4 framework in PII2P2S4 are unexpectedly large. Although the acceptor properties of the cage phosphorus sulphides have not been examined extensively, i t has been noted previously that P^S^ w i l l form complexes with certain metal carbonyls, but P4S7 apparently w i l l not , implying that the donor properties of P4S7 are less than those of P^S^. Finally, the failure of the P^ S^ N*" anion to react 102 with powerful methylating agents i s strong evidence for powerful acceptor properties in this ion. 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