Structure, magnetic properties, catalase activity and DFT studies of [Mn 2(μ-RCOO) 2(μ-OR) 2] 2+ type dinuclear manganese(III,III) complexes

Abstract

Three Mn(III,III) complexes containing dibenzoylmethane (dbm), Mn 2(OMe) 2(dbm) 2(ClH 2CCOO) 2 ( 1), Mn 2(OMe) 2(dbm) 2(Cl 2HCCOO) 2 ( 2) and Mn 2(OMe) 2(dbm) 2(Cl 3CCOO) 2 ( 3) were synthesized. Crystal structure determination and magnetic characterization were done for 2. The Mn⋯Mn distance in complex 2 is 2.865 Å. It exhibits antiferromagnetic coupling with exchange parameter | J| = 20.4 cm −1 ( H = −2 JS AS B ). All three complexes, though insoluble in common solvents, catalyse the disproportionation of hydrogen peroxide when dispersed on silica gel with turnover numbers ∼150–300. DFT simulations showed that bridging moieties have remarkable effect on intermetallic distances in dimanganese(III,III) complexes.