Synthesis, Crystal Structure and Luminescence of a New Two-dimensional Pb(II) Coordination Polymer

A new two-dimensional Pb(II) coordination polymer, [Pb-2(L)tpphz)(1.5)(NO3)(2)]center dot H2O (1), has been obtained by the hydrothermal reaction of tetrapyrido[3,2-a:2 ',3 '-c:3",2"-h:2 ''',3 '''-j]-phenazine (tpphz) and 2,2'-bipyridyl-3,3'-dicarboxylic acid (H2L). It crystallizes in monoclinic, space group P2(1)/c with a = 15.344(3), b = 14.111(3), c = 21.963(4) angstrom, beta = 106.89(3)degrees, V = 4550.1(16) angstrom(3), Z = 4, C48H26N13O11Pb2, M-r = 1375.20, D-c = 2.007 g/cm(3), F(000) = 2628, mu(MoK alpha) = 7.471 mm(-1), R = 0.0339 and wR = 0.0808. In 1, the two crystallographically independent tpphz ligands adopt the same bis-chelating coordination mode, but they play different roles in the structure of 1. One type of tpphz ligands bridge the Pb(II) cations to generate a zigzig chain, where the L anions are located on one side of the chain. Further, adjacent chains are linked by the other type of tpphz ligands into a two-dimensional layer structure. Additionally, the solid state luminescent property of 1 was also studied at room temperature.