Synthesis,Structure Characterization and Photoluminescence of a Novel Complex with（6,4,4）-Network [Ce_2（2,5-pydc）_3（H_2O）_2]（2,5-pydc = Pyridine-2,5-dicarboxylic Acid）

A new three-dimensional supramolecular Ce2(2,5-pydc)3(H2O)2](1) has been hydrothermally synthesized at 180 ℃ and characterized by single-crystal X-ray diffraction.X-ray crystal analyses reveal that the compound belongs to the monoclinic system,space group P21/c,C21H13Ce2N3O14,a = 6.561(1),b = 17.986(5),c = 9.411(3) ,β = 95.558(5)° and Z = 2.In the structure of 1,each Ce(1) center is surrounded by 2,5-pydc ligands,forming the 6-connected node,and the 2,5-pydc ligand coordinates to the Ce(Ⅲ) in two different coordination modes.In mode 1,the four oxygen atoms of two carboxyl groups connect neighboring Ce(Ⅲ) ions,giving 4-connected(4-c) second building unit(SBU-1).Furthermore,the structure is extended into a 2-D layer from SBU-1 by sharing Ce(1) atoms.In mode 2,the ligand coordinates to the Ce(Ⅲ) ion from the adjacent chain with the 4-connected(4-c) second building unit(SBU-2),generating a 1-D ladder from SBU-2 by sharing Ce(1) atoms.Finally,the structure is extended into a 6,4,4-c network.Its photoluminescence property was also investigated.

Synthesis,Structure Characterization and Photoluminescence of a Novel Complex with(6,4,4)-Network[Ce2(2,5-pydc)3(H2O)2](2,5-pydc=Pyridine-2,5-dicarboxylic Acid)

T A new three-dimensional supramolecularCe2(2,5-pydc)3(H2O)2](1)has been hydrothermally synthesized at 180℃ and characterized by single-crystal X-ray diffraction.X-ray crystal analyses reveal that the compound belongs to the monoclinic system,space group P21/c,C21H13Ce2N3O14,α=6.561(1),b=17.986(5),c=9.411(3)(A),β=95.558(5)° and Z=2.In the structure of 1,each Ce(1)center is surrounded by 2,5-pydc ligands,forming the 6-connected node,and the 2,5-pydc ligand coordinates to the Ce(Ⅲ)in two different coordination modes.In mode 1,the four oxygen atoms of two carboxyl groups connect neighboring Ce(Ⅲ)ions,giving 4-connected (4-c)second building unit(SBU-1).Furthermore,the structure is extended into a 2-D layer from SBU-1 by sharing Ce(1)atoms.In mode 2,the ligand coordinates to the Ce(Ⅲ)ion from the adjacent chain with the 4-connected(4-c)second building unit(SBU-2),generating a 1-D ladder from SBU-2 by sharing Ce(1)atoms.Finally,the structure is extended into a 6,4,4-c network.Its photoluminescence property was also investigated.