Studies on Manganese( <scp>II</scp> ) Complexes of N ‐Benzimidazole‐Functionalized 1,4,7‐Triazacyclononane: Crystal Structures, Properties and Combined Superoxide Dismutase and Catalase Functions

Two new manganese(II) complexes [MnL1Cl2] and [MnL2Cl]ClO4·MeOH were synthesized [L1 = 1-(benzimidazol-2-ylmethyl)-1,4,7-triazacyclononane; L2 = 1,4-bis(benzimidazol-2-ylmethyl)-1,4,7-triazacyclonone) and characterized by standard physical methods. The new complexes have better stability than the parent complex due to the introduction of benzimidazole groups on the backbone of tacn. The complexes were studied as superoxide dismutase (SOD) mimics by the riboflavin photoreduction method at pH 7.4. In basic or weakly basic solutions, the complexes decompose hydrogen peroxide catalytically, and possess the combined functions of SOD and catalase. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)