The Effect of Substituents on Catalytic Performance of bis-Thiosemicarbazone Mo(VI) Complexes: Synthesis and Spectroscopic, Electrochemical, and Functional Properties¹

Abstract—The preparation, characterization and electrochemical properties are reported for three new types of molybdenum(VI) complexes with bis-thiosemicarbazone ligands. All compounds were characterized by elemental analysis, electronic spectra, IR and ¹H NMR spectroscopies, thermogravimetric analysis, and cyclic voltammetry. The bis-thiosemicarbazone Mo(VI) complexes were tested as a catalyst for the homogeneous oxidation of olefins using tert-butyl hydrogen peroxide as an oxidant. The catalysts showed efficient reactivity in the olefins epoxidation reactions giving high yield and selectivity of the products, in most cases. Results showed that the bis-thiosemicarbazone ligands introduced both electronic and steric effects on catalytic performance of the prepared Mo(VI) complexes.