Polypyrazolylborate mixed-ligand complexes of Zr(IV), VO(IV) and MoO₂(VI)

Abstract

Mixed-ligand complexes of Zr(IV), VO(IV) and MoO₂(VI) containing tris(3,5-dimethylpyrazolyl)borate(L) and acetylacetonate(acac) have been prepared by the ligand exchange reactions of the appropriate acetylacetonate complct'xes with sodium hydrotris(3,5-dimethylpyrazolyl)borate ligand. The isolated 1:1 complexes Zr(acac)₃L, VO(acac)L and MoO₂(acac)L have been characterized by IR, NMR and EPR methods. The susceptibility of the mixed-ligand complexes Zr(acac)₃L and VO(acac)L to undergo oxidation and reduction reactions have been examined by electrochemical methods. Thermoanalytical studies on VO (acac)L and VO(acac)₂ have been performed by TG and DTG methods to study the influence of the chelating ligand L on the thermal stability of these metal acetylacetonate complexes.