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Synthesis, crystal structure and properties of a new dinuclear manganese(III) complex: a mimic for catalase
1State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, Nanjing 210093, PR China.
Abstract:
A new dinuclear manganese (III) complex [(ac)Mn(bbml)(2)Mn(ac)] x (BF(4))(2) x 3.5H(2)O (Hbbml=[bis(2-benzimidazolylmethyl)amino]ethanol, Hac=acetic acid) was synthesized and characterized by several physical methods. X-ray structure analysis shows that the complex has a dimeric unit and the two Mn(III) atoms are bridged by the oxygen atoms of the two ligands, forming a bis (micro-alkoxo)dimanganese core. The Mn-Mn distance is 3.2103 A. Electrospray mass spectrometry (ES-MS) experiment shows that the complex cation may easily have lost one or two ac(-) and leave unoccupied coordination site which would favor the coordination and activation of hydrogen peroxide. Furthermore, its catalytic activity for the disproportionation of hydrogen peroxide and the effect of added heterocyclic base were also investigated. The complex has some similarities to manganese catalase in structure and activity.
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