Synthesis and structure of a three-dimensional copper(II) coordination polymer with 1,2-bis(imidazol-1'-yl)ethane

The synthesis and characterization of the copper(II) complex [Cu(bim)(2.5)](ClO4)(2) . 2MeOH, where bim = 1,2-bis(imidazol-1'-yl) ethane, is described. The complex crystallizes in the monoclinic system, space group P2(1)/a, with cell constants a = 12.280(8), b = 12.533(5), c = 19.490(9) Angstrom, beta = 92.17(5)degrees and Z = 4. The structure was solved by a direct method and refined by full-matrix least squares to a residual R value of 0.064 and R-w of 0.066. The complex contains non-interacting ClO4- anions and a {[Cu(bim)(2.5)](2+)}(infinity) macrocation in which each metal ion involves a distorted square-based pyramidal coordination environment comprising five N atoms from five separate bim molecules. The total structure consists of two alternately stacked 2D sheets of copper(II) ions bridged through the bidentate imidazole molecules constituting a three-dimensional network. Consistent with the observed structural data the complex shows a typical axially symmetric ESR signal at room temperature.