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

Abstract

Three Mn(III,III) complexes containing dibenzoylmethane (dbm), Mn 2(OMe)2(dbm)2(ClH2CCOO)2 (1), Mn2(OMe)2(dbm)2(Cl2HCCOO) 2 (2) and Mn2(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 . It exhibits antiferromagnetic coupling with exchange parameter |J| = 20.4 cm-1 (H = -2JSAS 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. © 2011 Elsevier B.V. All rights reserved.