Synthesis, structure and catalase activity of the [TPA(2)Mn(2)(mu-Cl)(2)](2+) complex

초록

The dinuclear Mn complex (Et3NH)(2)[TPA(2)Mn(2)(mu-Cl)(2)](ClO4)(4) (I) was synthesized and characterized. Complex I was obtained from the reaction between MnCl2 and [H(3)TPA](ClO4)(3) in MeOH. Structural analysis of I showed the two Mn(II) atoms are bridged by two chloride ligands, forming a bis(mu-chloro)dimanganese core. The [Mn-2(mu-Cl)(2)](2+) core, with a Mn-Mn distance of 3.521(2) angstrom, is similar to the active site found in chloride-inhibited Mn catalase. EPR and temperature-dependent magnetic susceptibility measurements of complex I showed an antiferromagnetic interaction between the two S = 5/2 Mn centers with an exchange parameter J = - 8.8 cm(-1). Catalytic activity of H2O2 dismutation was measured for complex I and compared with other related complexes. Kinetic parameters of H2O2 dismutation were obtained and a possible catalytic mechanism of complex 1, related to chloride-inhibited Mn catalase, was suggested. (c) 2007 Elsevier Ltd. All rights reserved.

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