Hydrothermal Synthesis and Crystal Structure of a Cobalt(II) Coordination Polymer: [Co(C_2O_4)(bix)]_n (bix = 1,4-Bis(imidazol-1-ylmethyl)-benzene)

A new two-dimensional cobalt coordination polymer has been prepared and fully characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound [Co(C_2O_4)(bix)]_n 1 crystallizes in the monoclinic system, space group C2/c, with a = 11.549(3), b = 15.700(3), c = 9.260(2), β = 102.984(3)°, V = 1636.0(6)~3, C_(16)H_(14)CoN_4O_4, M_r = 383.23, D_c = 1.556 g/cm~3, μ(MoKα) = 1.078 mm~(-1), F(000) = 780, Z = 4, the final R = 0.0455 and wR = 0.1286 for 1483 observed reflections (I 2σ(I)). Of the compound, the Co center is octahedrally coordinated with oxalate acting as a tetra-dentate ligand coordinated to the cobalt atom and each bix serving as a bridging ligand by employing two N-donors to coordinate with the Co center. An infinite {Co_2(C_2O_4)_2}_∞ chain is formed along the a axis. Furthermore, the 1D chains are held together via bix ligands to generate a two-dimensional network structure with 1D coronal-like channels (ca. 5.691 × 15.700).