Synthesis, X-ray structure and study of a mixed ligand iron(III) complex with tridentate Schiff base as a homogeneous catalyst in the efficient oxidation of sulfides

A mononuclear mixed ligand complex of iron, [FeIII(N-OPh-sal)(acac)EtOH], where Hacac and N-HOPh-Hsal denote acetylacetone and N-hydroxyphenyl-salicylideneamine, respectively, has been synthesized and characterized by elemental analysis, spectral studies and X-ray crystallography. The catalytic system containing this complex and urea hydrogen peroxide as oxidizing agent was used to selectively oxidize a range of sulfides to the corresponding sulfoxides in good yields under mild conditions. The electronic spectra of the catalytic system were applied to explore reactivity and stability of the catalyst during sulfide oxidation reactions and to examine the nature of active species, as well.