Syntheses, Crystal Structures and Catalytic Activities of Two Novel Mn2Dy2O2 Complexes

Two novel heteronuclear manganese-dysprosium complexes have been synthesized and characterized, both of which contain a [Mn2Dy2O2] core ligated by eight (BuCO2-)-C-t anions and four neutral ligands. In complex 1, [Mn2Dy2O2((BuCO2)-C-t)8((BuCO2H)-C-t)(4)], all the four neutral ligands coordinated to Dy3+ are pivalic acids; Instead, two of these four pivalic acids have been replaced by ethanol in complex 2 [Mn2Dy2O2((BuCO2)-C-t)8((BuCO2H)-C-t)(2)(CH3CH2OH)(2)]. The crystal of complex 1 (C60H1 12Dy2Mn2O26, M-r = 1684.36) belongs to the orthorhombic system, space group Pbca with a = 19.853(3), b = 18.565(3), c = 20.952(3) angstrom, V= 7723(2) angstrom(3), Z = 4, D-c = 1.449 g/cm(3), S = 1.210, mu = 2.302 mm(-1), F(000) = 3448, the final R = 0.0802 and wR = 0.1570 for 8736 independent reflections. The crystal of complex 2 (C54H104Dy2Mn2O24, M-r = 1572.25) belongs to the monoclinic system, space group C2/c with a = 27.814(6), b = 13.194(3), c = 22.912(5) angstrom, beta = 124.89(3)degrees, V = 6897(3) angstrom(3), Z = 4, D-c = 1.514 g/cm(3), S = 1.086, mu = 2.570 mm(-1), F(000) = 3208, the final R = 0.0256 and wR = 0.0592 for 7763 independent reflections. The cyclic voltammogram and catalytic activity measurements of complex 1 suggest that this type of complex can serve as a catalyst for oxygen-evolving reaction.