Complexes of tungsten(VI) with thiomalic acid studied by 1H and 13C nuclear magnetic resonance spectroscopy

Abstract

Proton and carbon-13 nmr evidence is presented on the number, stoichiometry, geometry, and stability of the complexes which form when sodium tungstate and (D,L)-thiomalic acid are mixed in aqueous solution at pH values in the range 2–7. In particular, three (or four) complexes are detected having a 1:2 composition (metal–ligand), as well as a less stable complex which seems to be a 1:1 species. Preliminary data are also given on the exchange of bound ligand in these complexes.