Synthesis, crystal structure and activity for H2O2 disproportionation of abinuclear manganese(III) complex [(tol)Mn(bbml)(2)Mn(tol)](ClO4)(2)

The title binuclear Mn-2(III) complex was synthesized through the reaction of 2-[bis(2-benzimidazolylmethyl)amino]ethanol (Hbbml), Mn(DMSO)(6)(ClO4)(3 ) and o-toluic acid (Htol). X-ray structure analysis shows that the two Mn( III) atoms are bridged by the oxygen atoms of the two bbml ligands, forming a bis(mu -alkoxo)dimanganese core. Electrospray mass spectrometry (ES-MS) experiments shows that the complex cation may easily lose one or two tol(-) ligands leaving an unoccupied coordination site, which would favor the coo rdination and activation of H2O2. Furthermore, its catalytic activity for t he disproportionation of H2O2 and the effect of added heterocyclic base wer e also investigated. The complex has some similarities to manganese catalas e in structure and activity. (C) 2001 Elsevier Science Ltd. All rights rese rved.