Synthesis, Structure and Catalytic Activity of Titanium, Zirconium and Hafnium-Containing Polyoxometalates

Abstract

Polyoxometalates (POMs) represent by now a well-known class of discrete, molecular metal-oxides, which are attractive due to a large structural and compositional variety combined with a multitude of properties. Vacant (lacunary) polytungstate precursors allow for incorporation of a vast number of electrophiles including transition metals. The resulting products often have properties which render them of interest for potential applications in different areas such as catalysis, medicine and materials science. The exploration of the interaction between lacunary polyoxometalates (POMs) and group 4 (Ti, Zr and Hf) transition metal ions has been mainly driven by the fact that potential products may serve as oxidation catalysts or even as soluble molecular analogues of known Ti and Zr-containing heterogeneous catalysts. This document is a summary of three-year research conducted in this specific area, that is investigation of titanium containing POMs, the chemistry involved, synthesis, solid state and solution characterization and catalytic performance