Cyclohexene oxidation with tert-butylhydroperoxide and hydrogen peroxide catalyzed by new square-planar manganese(II), cobalt(II), nickel(II) and copper(II) bis(2-mercaptoanil)benzil complexes supported on alumina

New square-planar manganese(II), copper(II), nicke(II) and cobalt(II) complexes of a tetradentate Schiff-base ligand bis(2-mercaptoanil)benzil, H-2[mabenzil] have been prepared and characterized by elemental analyses, IR, UV-vis, conductometric and magnetic measurements. The results suggest that the symmetrical Schiff-base is a bivalent anion with tetradentate N2S2 donors derived from the thiopbenole groups and azomethine nitrogen. The formulae was found to be [M(mabenzil)] for the 1:1 non-electrolytic complexes. Alumina-supported metal complexes (ASMC; [M(mabenzil)/Al2O3]) catalyze the oxidation of cyclohexene with tert-buthylhydroperoxide (TBHP) and H2O2. (c) 2007 Elsevier B.V. All rights reserved.