Oxidation of sulfides including DBT using a new vanadyl complex of a non‐innocent o‐aminophenol benzoxazole based ligand

Reaction of a non‐innocent o‐aminophenol benzoxazole based ligand HL^BAP with VOCl₃ afforded a vanadyl complex, VOL^BIS (SQ), in which SQ is a 2,4‐di‐tert‐butylsemiquinone produced from hydrolysis of HL^BAP. The crystal structure of VOL^BIS (SQ) exhibits an octahedral geometry with the VO²⁺ center coordinated by two nitrogen and one oxygen atoms of L^BAP and two oxygen atoms of SQ. Electrochemical studies showed quasi‐reversible metal‐centered reduction and ligand‐centered oxidation of complex. The magnetic moment of VOL^BIS (SQ) is consistent with the spin‐only value expected for S = 1/2 system. The neutral species of VOL^BIS (SQ) is EPR active, which is consistent with a paramagnetic electronic ground state (S = 1/2). This result is in accordance with the vanadyl (IV) moiety surrounded by tridentate iminobenzosemiquinonate anion radical (HL^BIS)^?‐ and benzosemiquinone ligand (SQ)^?. The theoretical calculations confirm the experimental results. Furthermore, we present the optimal conditions for maximum efficiency of sulfide oxidation for oxidative desulfurization with hydrogen peroxide and 6 times reusability of catalyst for sulfoxidation of dibenzothiophene.