Alumina-supported Mn(II),Co(II),Ni(II) and Cu(II) N,N-bis(salicylidene)-2,2-dimethylpropane-1,3-diamine complexes:Synthesis,characterization and catalytic oxidation of cyclohexene with tert-butylhydroperoxide and hydrogen peroxide

摘要

New square-planar manganese(II),copper(II),nickel(II) and cobalt(II) complexes of a tetradentate Schiff-base ligand ' icylidene)-2,2-dimethylpropane-1,3-diamine,H_2[salpnMe_2]" 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 N_2O_2 donors derived from the phenolic oxygen and azomethine nitrogen.The formulae was found to be [M(salpnMe_2)] for the 1:1 non-electrolytic complexes.Alumina-supported metal complexes (ASMC;[M(salpnMe_2)/Al_2O_3]) catalyze the oxidation of cyclohexene with tert-buthylhydroperoxide (TBHP) and hydrogen peroxide.Oxidation of cyclohexene with TBHP gave 2-cyclohexene-1-one,2-cyclohex-ene-1-ol and l-(tert-butylperoxy)-2-cyclohexene whereas,oxidation with H_2O_2 resulted in the formation of cyclohexene oxide and cyclo-hexene-1,2-diol.Manganese)(II) complex supported on alumina "[Mn(salpnMe_2]-Al_O_3" shows significantly higher catalytic activity than other catalysts.