Hydrazone-based dioxidomolybdenum(vi) complexes: catalytic oxidation of omeprazole sulfide

Abstract

Four hydrazone-based molybdenum(VI) complexes, namely [MoO₂(L₁)·H₂O] 1, [MoO₂(L₂)·H₂O] 2, [MoO₂(L₃)·H₂O] 3, [MoO₂(L₄)·H₂O] 4, were successfully synthesized utilizing hydrazone ligands H₂L₁–H₂L₄. The structural and physicochemical properties of these ligands and their corresponding molybdenum complexes were elucidated through a comprehensive array of spectroscopic and analytical techniques. Single-crystal X-ray diffraction analysis (SC-XRD) unambiguously confirmed that all four complexes adopt a distorted octahedral arrangement around the metal center. Additionally, powder X-ray diffraction (P-XRD) studies verified the bulk purity of the synthesized complexes. The catalytic potential of all complexes was evaluated in the oxidation of omeprazole sulfide using green oxidant i.e. hydrogen peroxide (H₂O₂) as an oxidant under both dark and illuminated conditions. Remarkably, all complexes exhibited excellent catalytic efficiency, achieving complete conversion of the omeprazole sulfide substrate with 100% product selectivity.