Approach to Di/Triorganotin(IV) Cations via Hydrolysis of Stannate Salts Bearing Alkanesulfonate Ligands

Abstract

An in-depth study of the class of organotin cations bearing weakly coordinating trifluoromethanesulfonate/arylsulfonate has led to key insights into their stability, structural aspects, and role as catalysts. Related chemistry with alkanesulfonate ligands remains a missing link due to the strong Sn-O bond. The study reported herein describes the scope of diorganostannates, [n-Bu4N][R2Sn(OSO2R1)3] (R = n-Bu, R1 = Me(1), Et(2); R = Ph, R1 = Me(3)), as reactive substrates in the presence of adventitious water to afford [n-Bu2SnOH(OSO2Me)] (4), [n-Bu2Sn(H2O)4][n-Bu4N][OSO2Et]3·H2O (5), and [Ph2Sn(H2O)4][n-Bu4N]2[OSO2Me]4 (6), respectively, the latter two being the first examples of salt cocrystals comprising tetra(aqua)diorganotin cations. Hydrolysis of 3 in the presence of 1,4-bis((1H-imidazol-1-yl)methyl)benzene (bix) as the N-donor ligand proceeds via disproportionation and yields [Ph3Sn(bix)](OSO2Me) (7) along with an insoluble solid, likely derived from the hydrolysis of PhSn(OSO2Me)3. Direct evidence of this phenomenon can be gleaned from ESI-MS of 3, which identifies mass clusters corresponding to [Ph3Sn(OSO2Me)2]- and [PhSn(OSO2Me)3-H+]-. X-ray crystallographic studies of 1-7 are reported to establish their structural identity and the role of alkanesulfonate anions in the formation of supramolecular assemblies.