Synthesis and Crystal Structure of [Cu_3(dmpzm)_4(μ-1,3-dca)_2(dca)_4]·2H_2O (dmpzm=1,1'-Methylenebis-(3,5-dimethyl-1H-pyrazole),dca=dicyanamide)

The title compound, [Cu3(dmpzm)4(μ-1,3-dca)2(dca)4]·2H2O (dmpzm = 1,1'-methyle- nebis(3,5-dimethyl-1H-pyrazole), dca = dicyanamide) 1·2H2O, was synthesized via the reaction of CuCl2·2H2O with dmpzm and Na(dca), and characterized by elemental analysis and IR spectra. 1·2H2O crystallizes in the monoclinic system, space group C2/m with a = 13.578(3), b = 16.769(3), c = 14.769(3) , β = 104.10(3)o, V = 3261.4(11) 3, Z = 2, Dc = 1.466 g/cm3, T = 153(2) K, C56H68N34O2Cu3, Mr = 1440.09, F(000) = 1490, μ(MoKα) = 1.040 mm-1, S = 1.150, R = 0.0553 and wR = 0.1123 for 2744 observed reflections with I 2σ(I). The central copper atom is chelated by two dmpzm ligands and coordinated by two bridging dca anions, forming a slightly distorted octahedral geometry. The two external copper atoms adopt a square-pyramidal coordination geometry, coor- dinated by one chelating dmpzm ligand and one bridging and two terminal dca anions. Two inter- molecular hydrogen bonding interactions result in the formation of a 2D (4,4) hydrogen-bonded network.