Two novel Cd(Ⅱ) coordination polymers, [Cd 2(C 10H 2O 8)\5(H 2O) 6] n (1) and [Cd 4(C 6H 4O 2N) 8(H 2O) 4] n (2) (C 10H 2O 8=1,2,4,5-benzenetetracarboxyl and C 6H 4O 2N=nicotinato), were hydrothermally synthesized and characterized by X-ray diffraction of the single-crystal and fluorescence spectra. Complex 1 crystallizes in triclinic system, space group P1 with a=0.559 62(7) nm, b=0.777 58(6) nm, c=0.969 75(10) nm, α=111.981(5)°, β=101.649(6)°, γ=98.240(5)°, and Z=1. Final R=0.024 8(wR=0.078 5). Complex 2 belongs to orthorhombic system, space group Pbca with unit cell dimensions a=1.144 94(19) nm, b=1.209 69(6) nm, c=1.740 73(8) nm and Z=8. Final R=0.018 5(wR=0.034 8). Both the two complexes are coordination polymers with a two-dimensional infinite structure, the repeat unit is [Cd 2(C 10H 2O 8)(H 2O) 6] (1) and [Cd 4(C 6H 4O 2N) 8(H 2O) 4] (2) which are bridged by the ligands of 1,2,4,5-benzenetetracarboxyl(C 10H 2O 8) and nicotinato(NA), respectively. The two polymers show strong fluorescence with λ em=433 nm(λ ex=333 nm, 1) and λ em=423 nm(λ ex=330 nm, 2) in the solid state at room temperature. The emissions observed in the polymers are tentatively assigned to the ligands fluorescence(LLCT).
A novel Co（Ⅱ） coordination polymer was hydrothermally synthesized and characterized. The crystal crystallizes in the monoclinic system, space group C c with a =1.772 59（4） nm, b = 1.150 00（10） nm , c =2.452 76（11） nm, β =92.723（3）°, V =4.994 3 nm 3, Z =4, R =0.080 9, wR =0.213 4. The polymer based on [Co（μ 4,4′ bipy）（4,4′ bipy） 2(（H 2O） 2] n linear chains was cross linked by the H bond bridge of Co—OH 2…4,4′ bipy—Co and π π stacking interaction, producing extended 2D ladder structure. The susceptibility of the polymer at variable temperature（2 0300 K） shows a weak antiferromagnetic interaction and implies that the polymer has the tendency of spin transition. Also, the result of surface photovoltage spectroscopy（SPS） reveals that the polymer has a significant photo electronic transferring property in UV Vis regions, which correspond to π π transition, L M charge transfer transition（shoulder） and d d transition of Co 2+ ion, respectively.
