Syntheses, Crystal Structures and Characterization of Two New Pb(II) and Cu(II) Coordination Polymers Based on 2-(4-Fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline and Benzenedicarboxylate Ligands

Two new coordination polymers, [Pb(L)(1,3-bdc)]center dot 2.5H(2)O (1) and [Cu(L)(1,4-bdc)] (2) (L = 2-(4-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline; 1,3-bdc, 1,4-bdc = 1,3- and 1,4-benzenedicarboxylate), have been hydrothermally synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Crystal data for C54H40F2N8O13Pb2, triclinic, space group P (1) over bar, a = 9.3468(19), b = 9.4607(14), c = 15.581(3) angstrom, alpha = 90.44(4), beta = 101.13(3), gamma = 113.97(3)degrees, V = 1229.6(4) angstrom(3), Z = 1. Crystal data for 2: C27H15CuFN4O4, triclinic, space group P (1) over bar, a = 9.640(6), b = 10.941(8), c = 11.865(5) angstrom, alpha = 62.694(4), beta = 69.776(3), gamma = 79.915(5)degrees, V = 1043.2(11) angstrom(3), Z = 2. In 1, the Pb(II) atoms are bridged by the 1,3-bdc ligands to yield a chain structure. The ligands L are only located on one side of the chain, where pi center dot center dot center dot pi interactions among neighboring chains result in a supramolecular ladder, and the OH center dot center dot center dot O hydrogen bonding interactions further stabilize this structure. Compound 2 shows a layer structure, with stacking by pi-pi interactions to give a three-dimensional (3D) supramolecular architecture. N-H center dot center dot center dot O hydrogen bonding further stabilizes the structure of 2.