Hydrothermal Synthesis, Crystal Structure and Properties of a Novel 3D Metal-organic Coordination Polymer with Helical Chains Based on 5-(Imidazol-1-ylmethyl)isophthalic Acid

A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethypisophthalic acid (H2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillary ligand, [CdL(bpa)(0.5)] (1), has been obtained under hydrothermal conditions and characterized by elemental analysis, powder X-ray diffraction (PXRD), IR, thermal gravimetric analyses (TGA) and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P2(1)/c with a = 10.984(2), b = 10.1829(12), c = 17.782(3) angstrom, beta = 123.156(11)degrees, V = 1665.1(5) angstrom(3), Z = 4, M-r = 448.72, D-c = 1.790 g/c(m)3, R-int = 0.0871, F(000) = 892, the final R = 0.0687 and wR = 0.1294 for 2920 observed reflections (I > 2 sigma(I)). In complex 1, the L2- anions connect Cd(II) ions to form two-dimensional metal-organic layers (Cd2L2),I, in which the 1D helical chains (Cd-L)(n) are alternately arranged in a right- and left-handed sequence. These layers are further linked to build a 3D network by the bpa ligand. In addtion, photo luminescent properties for 1 are also investigated.