Structural characterization, magnetic studies, and catecholase-like activities of Mn12 clusters.

Two polynuclear, mixed-valence, sandwich dodecanuclear manganese clusters [MnII4MnIII4MnII4(μ4-O)2(μ3-O2CH)2(thme)4(MeCO2)10(H2O)4]·4H2O (1) and [MnII4MnIII4MnII4(μ4-O)2(μ3-O)2(thmp)4(MeCO2)10(H2O)4]·10H2O (2) are reported by the reaction of 1,1,1-tris(hydroxymethyl)ethane (H3thme) or 1,1,1-tris(hydroxymethyl)propane (H3thmp) with manganese(II) salts in methanol under reflux conditions. 1 and 2 were characterized by single-crystal X-ray diffraction, PXRD, cyclic voltammetry (CV), and variable temperature magnetic studies. 1 and 2 crystallize in the monoclinic (P21/n) and triclinic (P-1) systems, respectively, and each structure consists of a dodecanuclear mixed-valent sandwich core. Magnetic data confirmed that both complexes show dominant antiferromagnetic interactions between metal centers. The fascinating features of the non-covalent supramolecular contacts have been explored. The interplay of O⋯H interactions (i.e. O-H⋯O and C-H⋯O contacts) gives rise to the consolidation of discrete units of 1 and 2 into supramolecular architecture. Catecholase activity data show that the present clusters catalyze the oxidation of 3,5-DTBC to 3,5-DTBQ with efficient Kcat values. [ABSTRACT FROM AUTHOR]