Quest for Organotin(IV) Cations Containing O,C,O-Chelating Ligands

Abstract

A set of triorganotin(IV) compounds Ph2L1SnX and Ph2L2SnX (1−9) with O,C,O-chelating ligands L1 and L2 (L1 = 2,6-(MeOCH2)2C6H3 and L2 = 2,6-(t-BuOCH2)2C6H3) containing different electronegative substituents X (X = I, CF3COO, CF3SO3, PF6, and HgI3) was prepared. These compounds have been characterized by elemental analysis, ESI-MS, and 1H, 13C, and 119Sn NMR spectroscopy. X-ray diffraction analysis showed that the decrease of the nucleophilicity of X resulted in the formation of organotin cations stabilized by two strong Sn−O intramolecular interactions. In this transformation the ligand geometry about the tin atom changed from tetrahedral to trigonal bipyramidal with the OR groups in trans arrangement. Solution NMR studies indicated that the coordination geometry of these compounds is the same in the solid state and solution.