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On the structure of dimethylthallium acetylacetonate in solution

1965; Elsevier BV; Volume: 1; Issue: 4 Linguagem: Inglês

10.1016/s0020-1650(65)80020-4

1878-3473

Hideo Kurosawa, Kiyoshi Yasuda, Rokuro Okawara,

Synthesis and Characterization of Heterocyclic Compounds

In o r d e r to s t u d y the c o n f i g u r a t i o n and the n a t u r e o f bond ing o f d i m e t h y l t h a l l i u m a c e t y l a c e t o n a t e , we have examined the NMR and i n f r a r e d s p e c t r a o f t h i s compound. The i n f r a r e d spec t rum of (CH3)2Tl(acac) in c h l o r o f o r m (Table 1) shows the p r e s e n c e o f bands a s s o c i a t e d wi th bo th t he symmetr ic and a n t i s y m m e t r i c T1-C s t r e t c h i n g v i b r a t i o n s a t 482 cm °1 and 566 cm °1 , r e s p e c t i v e l y . Th is s u g g e s t s t h a t t he d i m e t h y l t h a l l i u m group shou ld have a n o n l i n e a r c o n f i g u r a t i o n i n c h l o r o f o r m . Other f e a t u r e s o f the i n f r a r e d spec t rum a r e s i m i l a r to t h o s e (1) o f known c h e l a t e d me ta l a c e t y l a c e t o n a t e s . NMR d a t a a r e g iven in Table 2. For compar i son , NMR d a t a f o r d i m e t h y l t h a l l i u m o x i n a t e which has been r e p o r t e d (2) to have a c h e l a t e d s t r u c t u r e in c h l o r o f o r m by the s tudy o f the e l e c t r o n i c s p e c t r a a r e i n c l u d e d i n the t a b l e . In c h l o r o f o r m , the ~ v a l u e s o f the y and methyl p r o t o n s o f the a c e t y l a c e t o n a t e group in (CH3)2Tl(acac) a r e a t a h i g h e r magne t i c f i e l d t han t h o s e (3 ,4) found in t i n ( I V ) a c e t y l a c e t o n a t e s , w h i l e in Tab le 1 i t i s seen t h a t the C=0 s t r e t c h i n g f r equency i s h i g h e r and the M-0 s t r e t c h i n g f r e q u e n c y i s lower than t h o s e (5 ,6) in t i n ( I V ) a c e t y l a c e t o n a t e s , r e s p e c t i v e l y . This c o r r e l a t i o n between t h e r e s u l t s o f the NMR and the i n f r a r e d s p e c t r a has been e s t a b l i s h e d p r e v i o u s l y ( 3 ) f o r t i n ( I V ) a c e t y l a c e t o n a t e s . Thus our r e s u l t s i n d i c a t e t h a t the a c e t y l a c e t o n a t e l i g a n d i s r a t h e r weak ly c h e l a t e d to the d i m e t h y l t h a l l i u m moie ty in c h l o r o f o r m s o l u t i o n .