Synthesis and structural characterization of three manganese(III) complexes with N2O2 donor tetradentate Schiff base ligands: Exploration of their catalase mimicking activity

Three manganese(III) complexes, [Mn(L-1)(N-3)(H2O)]center dot CH3OH center dot H2O (1), iMn(L-2)(N-3)(H2O)] (2) and [Mn(L-3) (H2O)(2)]ClO4 (3) {where H2L1 = N,N'-bis(3-methoxysalicylidene)1,2-ethanediamine, H2L2 = N,N'-bis(3-methoxysalicylidene)1,2-diamino-l-propene and H2L3 = N,N'-bis(3-methoxysalicylidene)1,2-propanediamine}, have been synthesized and characterized. Single crystal x-ray diffraction analysis confirmed their structures. Weak non covalent interactions generate extended supra-molecular assemblies in all three complexes. Catalase mimicking activities (catalytic decomposition of hydrogen peroxide into oxygen and water) of the complexes have been investigated. Complex 3 catalyzes the decomposition of hydrogen peroxide most effectively. The higher catalase mimicking efficiency of complex 3 has been related to its structure.