Coordination chemistry of dioxotungsten(VI): synthesis and characterization of some isothiocyanato complexes of dioxotungsten(VI) with biologically active chelating molecules

The synthesis and characterization of some novel isothiocyanato complexes of dioxotungsten(VI) with the compositions [WO2(NCS)2(L)2(H2O)] where L=benzimidazole or 2,3-dimehyl-1-phenyl-3-pyrazoline-5-one; [WO2(NCS)2 (L-L)] where L-L = 2-aminobenzothiazole, 4-amino-2,3-dimethyl- 1-phenyl-3-pyrazoline-5-one, 2-(2'-pyridyl)imidazole or 2,3-dimethyl- 4-methylamino methanesulphonatesodium monohydrate-l-phenyl- 3-pyrazoline- 5-one and [WO2(NCS)2(PYBZL)(H2O) have been reported. These mixed ligand complexes have been prepared by the interaction of tetraisothiocynatodioxo tungsten(VI) anion with the respective ligand in aqueous medium in the presence of HCl. The complexes which have been characterized by elemental analysis, thermogravimetric analysis, conductance and magnetic measurements, and electronic and IR spectral studies, are found to contain cis - WO2 structure. (author)