Synthesis, characterization and catalytic activity of new Cr(III) complex in oxidation of primary alcohols to aldehydes

New mononuclear complex of chromium(III), [Cr(bp)(N3)(CH3OH)]·2CH3OH has been synthesized where H2bp is N,N-bis(2-hydroxy-3,5-di-tert-butylbenzyl)-N’,N’-dimethylethylene-1,2-diamine. The complex was characterized by elemental analyses and spectroscopic methods and X-ray diffraction analysis. Single crystal X-ray diffraction structure analysis of the complex revealed that the chromium ion is octahedrally coordinated where the bis(phenolate) ligand (bp2−) is N2O2-bonded to the Cr(III) center in a tetradentate dinegative fashion. The catalytic potential of this complex has been tested for the oxidation of primary alcohols using H2O2 as oxidant. The effects of various parameters including molar ratio of oxidant to substrate, temperature, and solvent have been studied. Excellent conversions have been obtained for the oxidation of benzyl alcohols containing electron-donating groups on para-position.