Hydrothermal Synthesis and Crystal Structure of a Lead(II) Polymer with a Two-dimensional Network Structure: [Pb2(PDB)2(phen)]n•nH2O

A new metal-organic complex [Pb-2(PDB)(2)(phen)](n)center dot nH(2)O (H2PDB = pyridine-3,4-dicarboxylic acid, phen = 1,10-phenanthroline) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P (1) over bar with a = 7.2472(5), b = 10.6966(8), c = 16.2176(12) angstrom, alpha = 98.2960(10), beta = 91.6430(10), gamma = 97.4810(10)degrees, V = 1233.53(16) angstrom(3), C26H16O9N4Pb2, M-r = 942.81, D-c = 2.538 g/cm(3), mu(MoK alpha) = 13.697 mm(-1), F(000) = 872, Z = 2, the final R = 0.0247 and wR = 0.0654 for 3886 observed reflections (I > 2 sigma(I)). In the crystal structure, the Pb(1) atom is six-coordinated with four carboxylate oxygen atoms from three different PDB ligands and two nitrogen atoms from phen ligand, showing a distorted octahedral geometry; the Pb(2) atom is four-coordinated with four carboxylate oxygen atoms from four different PDB ligands, showing a distorted tetrahedral geometry It exhibits a three-dimensional supramolecular network structure formed by hydrogen bonds and pi-pi interactions.