Quest for Organotin(IV) Cations Containing O,C,O-Chelating Ligands
摘要:
A set of triorganotin(IV) compounds (Ph2LSnX)-Sn-1 and (Ph2LSnX)-Sn-2 (1-9) with O,C,O-chelating ligands L-1 and L-2 (L (1) = 2,6-(MeOCH2)(2)C6H3 and L-2 = 2,6-(t-BuOCH2)(2)C6H3) containing different electronegative substituents X (X = I, CF3COO, CF3SO3, PFr6 and HgI3) was prepared. These compounds have been characterized by elemental analysis, ESI-MS, and H-1, C-13, and Sn-119 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.