Synthesis, crystal structure and catalytic activity of a new Mo Schiff base complex with Mo histidine immobilized on Al-MCM-41 for oxidation of sulfides

A cis-dioxomolybdenum(VI) complex with Schiff base ligand derived from salicylaldehyde and l-histidine was prepared and designated as MoO2(Sal-His). Characterization of MoO2(Sal-His) was accomplished with elemental analysis, FT-IR, UV–Vis and TGA. X-ray crystallography studies revealed that the coordination of Mo in MoO2(Sal-His) is a distorted octahedron formed by tetradentate histidine Schiff base ligand and two binding oxygen atoms. MoO2(Sal-His) was used either alone or immobilized within Al-MCM-41 as sulfoxidation catalyst for a variety of sulfides with H2O2 as oxidant. The latter proved to be a very active and reusable heterogeneous sulfoxidation catalyst, providing 70–99% conversion and 80–95% selectivity.