Hydrolysis of Bis((trimethylsilyl)methyl)tin Dihalides. Crystallographic and Spectroscopic Study of the Hydrolysis Pathway

The synthesis and characterization by multinuclear NMR spectroscopy of the diorganotin dihalides (Me 3 SiCH 2 ) 2 SnX 2 ( 1, X = Cl; 2, X = Br), the diorganotin dichloride water adduct (Me 3 SiCH 2 ) 2 SnCl 2 ·H 2 O ( 1a ), the dimeric tetraorganodistannoxanes [(Me 3 SiCH 2 ) 2 (X)SnOSn(Y)(CH 2 SiMe 3 ) 2 ] 2 ( 3, X = Y = Cl; 4, X = Br, Y = OH; 5, X = Br, Y = F; 6, X = Y = OH; 8, X = Cl, Y = OH), and the molecular diorganotin oxide cyclo -[(Me 3 SiCH 2 ) 2 SnO] 3 ( 7 ) are reported. The structures in the solid state of compounds 1a, 3, 6, and 7 were determined by single-crystal X-ray analysis. In toluene solution, the hydroxy-substituted tetraorganodistannoxane 6 is in equilibrium with the diorganotin oxide 7 and water. The eight-membered diorganotin oxide cyclo -[(Me 3 SiCH 2 ) 2 SnO] 4 ( 7a ) is proposed to be involved in this equilibrium. On the basis of the results of this and previous works, a general hydrolysis pathway is developed for diorganotin dichlorides containing reasonably bulky substituents.