Cis-trans-Isomere von Diazadiphosphetidin-Derivaten: Fünf Kristall- und Molekülstrukturen Cis-trans Isomers of Diazadiphosphetidine Derivatives: Five Crystal and Molecular Structures

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 c o m p o u n d s [ R 3 C P ( X ) N R ] 2 ( R = C H 3 ; X = S , T e f o r eis i s o m e r s a n d X = l o n e p a i r , S , T e f o r trans i s o m e r s ) ( 2 6 ) w e r e d e t e r m i n e d f r o m s i n g l e c r y s t a l X r a y d a t a . T h e f o u r m e m b e r e d P N r i n g s i n t h e eis i s o m e r s 2 a n d 3 s h o w s i g n i f i c a n t d e v i a t i o n s f r o m p l a n a r i t y a t t r i b u t e d t o s t e r i c o v e r c r o w d i n g i n t h e m o l e c u l e s . T h e trans i s o m e r s 4—6 a r e p l a n a r . T h e P N b o n d l e n g h t s ( m e a n v a l u e s f o r 2 6 : 1 7 1 . 4 , 1 7 0 , 1 7 1 . 6 , 1 6 9 . 2 a n d 1 6 8 . 3 p m ) i n t h e eis i s o m e r s a r e n o t s i g n i f i c a n t l y d i f f e r e n t f r o m t h e c o r r e s p o n d i n g l e n g t h s i n t h e trans i s o m e r s 5 a n d 6 .