Syntheses, Structure and Thermal Analysis of a Cobalt Coordination Polymer with Multiform Helical Features Based on Flexible Iodo-dicarboxylate Ligand and N-donor Ancillary Ligand

A new 3D complex, [Co(L)(bpe)(0.5)(H2O)(2)](n), (1, H2L = 5-iodo-benzene-1,3-dioxyacetic acid, bpe = 1,2-bis(4-pyridyl)ethylene), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. It is formulated as C16H16CoINO8, crystallizes in monoclinic, space group P2(1)/c, with a = 9.806(2), b = 6.5492(13), c = 28.187(8) angstrom, beta = 100.12(3)degrees, V = 1782.0(7) angstrom(3), Z = 4, D-c = 1.998 g/m(3), F(000) = 1052, M-r= 536.13, the final R = 0.0393 and wR = 0.0858 for 3134 observed reflections with I > 2 sigma(I). Complex 1 displays a 3D framework with multiform helical features, left- and right-handed triple helical braids and single helical chains, which can be simplified as a new type of (3,4)-connected lattice with a (6 center dot 10(2))(6(2)center dot 10(4)) Schlafli symbol. Moreover, the thermal analysis of complex 1 has also been investigated.