Kiyoshi Yasuda

Occurrence of dimeric trimethyltin hydroxide

Abstract The infrared spectra of trimethyltin hydroxide are examined in the solid state and in solution. These spectra are discussed in terms of a weak coordination of the oxygen atom with the tin atom. Ebulliometric molecular weight determinations of trimethyltin hydroxide in carbon tetrachloride, chloroform or benzene solution indicate a dimeric molecule [(CH 3 ) 3 SnOH] 2 . The SnO stretching vibration band in solid trimethyltin hydroxide is observed at 370 cm −1 , while in carbon tetrachloride solution it is found in the 500–580 cm −1 region. The OH stretching vibration band which is observed at 3620 cm −1 in the solid shifts to 3658 cm −1 in solution. Only one SnC stretching vibration band is observed at 540 cm −1 in the solid state, while in solution an additional absorption associated with the SnC stretching vibration is observed. These facts suggest that in the solid state trimethyltin hydroxide is a linear polymer in which the planar (CH 3 ) 3 Sn group is bridged by the -O(H)- unit, whereas in solution it has a dimeric structure, in which two SnO groups form a four-membered ring.

Reactions of triethylindium with halomethanes: preparations and properties of diethylindium halides

Triethylindium, Et3In, reacted with CH2X2 (X = 1 and Br) and CCl4 (or CHCl3) to give the corresponding diethylindium halide, Et2InX (X = I, Br and Cl). These reactions are explained as proceeding through a carbenoid intermediate (Et2InCH2X) (I) (X = I and Br) and (Et2InCCl3) (II), respectively. Methylene from (I) was added to cyclohexene to give norcarane, whereas dichloromethylene from (II) was preferentially inserted into the InC bond to give 2-pentene. Et2InX (X = I, Br and Cl) were found to have a dimeric structure with a nonlinear CInC skeleton. Et2InF was prepared from Et3In and Et3SnF and polymeric structure with linear CInC units is suggestd for it.

Preparation and spectroscopic studies of dialkyltin hydroxide nitrate, trimethyltin nitrate and its monohydrate

Abstract The reaction between a dialkyltin oxide (alkyl = CH3 or C2H5) and dilute nitric acid gives a new type of compound, the dialkyltin hydroxide nitrates R2Sn(NO3)(OH). These are stable, high-melting, crystalline substances, which are soluble in water and in methanol but insoluble in non-polar solvents. Their infrared spectra indicate that the oxygen atoms of the OH and NO3 groups are coordinated strongly with the tin atoms. The reaction of trimethyltin hydroxide with dilute nitric acid yields trimethyltin nitrate monohydrate (m.p. 98–99°), the sublimation of which gives anhydrous trimethyltin nitrate (m.p. 140°). The anhydrous compound is hygroscopic and reverts to the monohydrate upon the absorption of moisture. In anhydrous trimethyltin nitrate it is suggested that the planar trimethyltin groups are bridged by NO3 units. The most probable structure of trimethyltin nitrate monohydrate is one in which the bridged structure of the anhydrous compound is retained but with the water molecule located in the plane of the trimethyltin group and weakly coordinated to the tin atom.

Preparation and properties of dialkyltin nitrate derivatives

Abstract Several series of dialkyltin (R = CH 3 , C 2 H 5 , n-C 3 H 7 , n-C 4 H 9 ) nitrate derivatives: dialkyltin nitrate hydroxides (IV), tetraalkyl-I,3-dinitratodistannoxanes (III),tetraalkyl-I-nitrato-3-hydroxydistannoxanes (II) and dibutyltin dinitrate (V) were prepared. The structures of (III) and (IV) are suggested. The existence of R 2 SnX(OH) where X is NO 3 and Cl is indicated and discussed.

Studies of organoindium compounds reactions of triethylindium with thiobenzophenone, benzophenone, benzaldehyde, phenylisocyanate and benzonitrile

Abstract Triethylindium reacted with thiobenzophenone, benzophenone, benzaldehyde, phenyl isocyanate and benzonitrile, forming colored complexes at low temperature. With elevation of temperature, these complexes, except that of benzonitrile (V), rearranged, giving hydrogen migration products (I) and (II) and ethyl group migration products (III) and (IV) exclusively. These diethylindium compounds were isolated and identified and a possible explanation for these selective rearrangements is discussed on the basis of the steric hindrance about the carbon atom of the functional group of the organic reagents. The fairly thermally stable benzonitrile complex was forced to partially decompose at more elevated temperatures, giving ethyl group migration and a small amount of hydrogen migration products at the trimer of benzonitrile.

On the structure of dimethylthallium acetylacetonate in solution

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 .