Wheel-shaped polyoxo and polyoxothiometalates: From the molecular level to nanostructures

Abstract

Publisher Summary This chapter discusses rings of 3d-metals in moderate oxidation states (II, III) with 0, N, and S-donor ligands; wheel-shaped polyoxo(thio)metalates containing metals in high oxidation states (IV, V, VI); and more sophisticated species based on Mo(VI), W(VI), and MO(V) metal ions located at the boundary of molecular and solid-state chemistry. Combination of hard σ-bonding systems with soft hydrogen-bonding interactions can lead to wheels containing more and more high-spin ground states to open the way to molecular magnets. Predicted vacant polyoxometalates can be easily obtained by controlled hydrolyses, and are good reactive nucleophiles that can form a remarkable set of precursors for the design of large soluble molecules. Replacement of oxoatoms in polyoxoanions by sulfide groups modified the electronic properties and the archetypal geometries to build a new family of polyoxothioanion. Synthesis of the big wheels, in addition to the intellectual satisfaction it produces, serves as a mini-reactor to perform hydrolysis reactions at the molecular level. Their colloidal solutions could also serve to develop inorganic reactions in poly-phased medium. The wheel approach might also make it possible to obtain, at the molecular level, compounds with interesting bulk physical properties (magnets, electron reservoirs, catalysts).