Synthesis and structural characterization of triorganotin(IV) methoxyacetates: Correlation of ^{13}C CPMAS NMR spectroscopy with single crystal structure

Abstract

The triorganotin(IV) derivatives of methoxyacetic acid, methoxyacetatotriphenyltin(IV) ( 1), methoxyac- etatomethyldiphenyltin(IV) (2), and methoxyacetatotriphenyltin(IV) (3) were synthesized by the reaction of methoxyacetic acid with Ph3SnCl, Ph2MeSnI, and Me3SnCl, respectively, with the aid of potassium iso-propoxide. Compounds 1-3 were characterized by elemental analysis, mass spectrometry, infrared spectroscopy (IR), and 1 H, 13 C, 119 Sn NMR, and 13 C CPMAS NMR. The molecular structures of the three complexes were determined by single-crystal X-ray diffraction. Crystallography shows that all three complexes adopt polymeric trans-C3SnO2 trigonal bipyramidal structures with the oxygen atoms occupying axial positions. The X-ray structures reveal two independent, non-symmetric, but essentially identical molecules in the crystal- lographic asymmetric unit of 1 and 3, in which they link to each other by a bridged methoxyacetato ligand. The 13 C CPMAS NMR spectroscopy of 1 and 3, with two sets of signals for the groups linked to tin, is consistent with the two independent trigonal bipyramids in the asymmetric unit. The prepared compounds show much higher solubility in ethanol in comparison to acetate derivatives.