Comparison of polyoxo and polyoxothiometallate rings: a theoretical approach

Abstract

The electronic structures of a synthesized oxothiomolybdate ring and its hypothetic oxo analog were studied by DFT calculations. Different intermediate structures, which can appear during ring formation, were analyzed and their stabilities systematically compared. No significant difference between the two systems has been found in the ring assembly processes from elementary bricks [Mo₂O₂X₂(H₂O)₆]²⁺ (X = S, O). It is suggested that the assembly of the oxo ring can be perturbed by the coexistence of two close-in-energy isomers for the oxo dication [Mo₂O₄(H₂O)₆]²⁺, having short and long Mo–Mo distances.