Hydrolysis of (Me3SiCH2)PhSnCl2. Isomerisation of the dimeric tetraorganodistannoxane [(Me3SiCH2)Ph(Cl)SnOSn(Cl)Ph(CH2SiMe3)]2

Abstract

The hydrolysis of (Me₃SiCH₂)PhSnCl₂ (1) was studied under two different reaction conditions (i) by using an excess of aqueous NaOH in toluene at reflux temperature and (ii) by using small amounts of NEt₃ and water in CH₂Cl₂ at room temperature. For (i) the products (Me₃SiCH₂)Ph₂SnOSnPh₂(CH₂SiMe₃) (2) and [(Me₃SiCH₂Sn)₁₂O₁₄(OH)₆](OH)₂ (3) were isolated indicating that a phenyl group migration took place. For (ii) the dimeric tetraorganodistannoxane [(Me₃SiCH₂)Ph(Cl)SnOSn(Cl)Ph(CH₂SiMe₃)]₂ (4) was obtained. In solution, 4 exists as an equilibrium mixture of all five possible isomers 4a–4e; in the solid state two of these isomers 4d and 4e co-crystallized in the same crystal modification. The observation of interconvertible isomers of 4 was attributed to the kinetic lability of the ladder-like Sn₄O₂Cl₄ structural motif. Compounds 1 and 4 were investigated by X-ray crystallography.