The reactivity of hydrotris(3-methyl-2-thioxo-1-imidazolyl)borate (Tm) towards organotin(IV) acceptors. An unprecedented monodentate coordination mode of Tm ligand

The reaction between RSnCl3 (R=Me, Bun or Ph), R2SnCl2 (R=Me, Et, Bun or Ph) and R3SnCl (R=Me, Bun, Ph or cy) acceptors and equimolar amounts of hydrotris(3-methyl-2-thioxo-1-imidazolyl)borate potassium salt K[Tm] yields the complexes [(Tm)RSnCl2], [(Tm)R2SnCl] and [(Tm)R3Sn], respectively. The NMR data (1H, 119Sn) showed the mono- and di-organotin derivatives to be five-coordinated in solution, whereas the triorganotin(IV) derivatives are tetrahedral both in solution and in the solid state, as confirmed by X-ray crystallography. The X-ray crystal structure of [(Tm)cy3Sn] is the first example of a complex containing the Tm-ligand coordinated in monodentate fashion, with the tin in a quasi-regular tetrahedral environment and SnS bond being 2.478(1) Å.