Synthesis and Crystal Structure of a Cadmium(II) Coordination Polymer: [Cd2Cl4(bpme)]n•n(2H2O)

A novel coordination polymer, [Cd2Cl4(bpme)](n)center dot n(H2O) (1, bpme = 2,5-bis(benzoimidazol-2-yl)pyrazine), has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal of the complex belongs to the triclinic system, space group P (1) over bar, with a = 7.0737(9), b = 8.7886(11), c = 9.4561(12) angstrom, alpha = 105.3580(10), beta = 94.981(2), gamma = 96.879(2)degrees, V = 558.46(12) angstrom(3), M-r = 714.97, Z = 1, F(000) = 346, D-c = 2.126 g/cm(3), mu = 2.412 mm(-1), T = 296(2) K, S = 1.057, R = 0.0533 and wR = 0.1480. According to the structural analysis, the Cd(II) ion adopts a slightly distorted six-coordinated octahedral geometry. The Cd(II) atoms are bridged by four Cl atoms along the a direction, forming infinite straight chains which are further constructed to generate 2D network layer structures through the mu(4)-N bpme ligand in the b direction, and such 2D network layer structures finally form a novel three-dimensional infinite supramolecular framework through weak pi-pi stacking between two network layers and hydrogen bonds.