Manganese(II) complexes of hydrazone based NNO-donor ligands and their catalytic activity in the oxidation of olefins

The reaction between tridentate NNO donor hydrazone ligands, (E)-2-cyano-N-(phenyl(pyridin-2-yl)methylene)acetohydrazide (HL1) and (E)-2-cyano-N-(1-(pyridin-2-yl)ethylidene)acetohydrazide (HL2), with MnCl(2)4H(2)O in methanol resulted in [Mn(HL1)Cl-2(CH3OH)] (1) and [Mn(HL2)Cl-2(CH3OH)] (2). Molecular structures of the complexes were determined by single-crystal X-ray diffraction. All of the investigated compounds were further characterized by elemental analysis, FT-IR, TGA, and UV-Vis spectroscopy. These complexes were used as catalysts for olefin oxidation in the presence of tert-butylhydroperoxide (TBHP) as an oxidant. Under similar experimental conditions with equal manganese loading, the presence of [Mn(HL2)Cl-2(CH3OH)] (2) resulted in higher conversion than [Mn(HL1)Cl-2(CH3OH)] (1). [GRAPHICS