One-pot synthesis, crystal structure and theoretical calculations of a dinuclear Mn(III) complex with in-situ generated O,N,O- and O,N-donor dichelating hydrazone ligand

Abstract

A new dinuclear Mn(III) complex, [Mn2(L)2(CH3OH)2] (1), was synthesized by one-pot reaction of 2-aminobenzoylhydrazide, salicylaldehyde and Mn(OAc)2·4H2O in methanol (H3L = (E)-N'-(2-hydroxybenzylidene)-2-((E)-(2-hydroxybenzylidene)amino)benzohydrazide). The obtained compound was characterized by elemental analysis, spectroscopic methods, thermogravimetric analysis (TGA) and single crystal X-ray studies. Structural studies indicated that a ditopic O,N,O- and O,N-dichelating hydrazone ligand is obtained by in-situ condensation of 2-aminobenzoylhydrazide with salicylaldehyde which simultaneously is coordinated to two manganese(III) ions as trianionic ligand, (L)3-. During the formation of complex, Mn(II) is oxidized to Mn(III) by aerial oxygen and the Mn(III) ions have distorted octahedral geometry. The spectroscopic and structural properties of complex 1 were further studied by DFT calculations. DFT calculations on complex 1 indicated that the experimental geometric parameters and spectroscopic data are in the reasonable range obtained by theoretical studies.