Synthesis, characterization and catalytic study of a novel iron(III)-tridentate Schiff base complex in sulfide oxidation by UHP

An hydrazone Schiff base-iron(III) complex using salicylidene benzoyl hydrazine (L) as ligand has been synthesized and characterized by elemental analyses, IR, 1H and 13C NMR and UV–Vis spectroscopy. Oxidation of sulfides to sulfoxides in one-step was conducted by this complex catalyst using urea hydrogen peroxide (UHP) in mixture of CH2Cl2/CH3OH (1:1) under air at room temperature. The effect of the reaction conditions on the oxidation of methylphenylsulfide was studied by varying the amount of the catalyst, reaction temperature, reaction time and the amount of UHP. The results showed that using this system in the oxidation of sulfides, sulfoxides were obtained as the main products, together with variable amounts of sulfones (⩽9%), depending on the nature of the substrate.

Graphical abstractAn iron(III) complex of a tridentate Schiff base ligand has been synthesized and characterized by elemental analyses, infrared and UV–Vis spectroscopy. The iron complex efficiently catalyzes the selective oxidation of various sulfides to sulfoxides with UHP at room temperature within short reaction times (15 min).Figure optionsDownload full-size imageDownload as PowerPoint slide