Abstract：A supramolecular Cd(Ⅱ) complex[Cd(bpdc)(phen)2(H2O)]·6H2O (1) was synthesized with 2,4’-biphenyldicarboxylic acid (H2bpdc) and 1,10-phenanthroline (phen) under hydrothermal conditions and characterized by single-crystal X-ray diffraction elemental analysis, and IR spectrum. Single-crystal X-ray analysis reveals complex 1 crystalizes in the triclinic P1 space group, the metal center Cd(Ⅱ) ion is six-coordinated and exhibits a distorted octahedron geometry arrangement. 3D supramolecular structure could be formed taking into account two kinds of hydrogen bonds and π—π interactions. At the same time, we discussed the luminescent properties of complex 1 in the solid-state as well as in the solvents at different temperatures. When excited at 350 nm, in the solid state at 298 K, 1 has purple luminescence with emission band at 390 nm; in the solid state at 77 K, 1 displays two emission bands at 380 and 520 nm. Because the vibration structure is more defined at low temperature, at 298 K, 1 also has purple luminescence in DMSO and CH3OH solutions with emission bands at 380 and 375 nm, which are blue-shifted compared with solid-state maximum emission band. These all can be attribute to the π*→π transition based on the coordinate ligands. The fluorescence decay curves of complex 1 indicate that the processes of decay consist of two components. At 298 K, the lifetime of 1 is longer in DMSO solution (τ1=1.73 μs and τ2=14.07 μs) than that in CH3OH solution (τ1=1.21 μs and τ2=12.44 μs). Moreover, the lifetime of 1 is longer at 77 K (τ1=1.96 μs and τ2= 16.11 μs) than that at 298 K in the solid state (τ1=1.20 μs and τ2=11.34 μs). The results might be caused by the increase in radiative rate and decrease in non-radiative rate at low temperature.
[1] Zhang H B, Zhou L J, Wei J, et al. J. Mater. Chem., 2012, 22: 21210. [2] Chou P T, Chi Y, Chung M W, et al. Coord. Chem. Rev., 2011, 255: 2653. [3] Dario B, Fabrizia G, Lucia M, et al. New J. Chem., 2011, 35: 339. [4] Fan L M, Zhang X T, Zhong S, et al. Crystal Growth & Design, 2013, 13: 2462. [5] Fan R Q, Wang L Y, Wang P, et al. J. Solid State Chem., 2012, 196: 332. [6] Sun Y Q, Zhang J, Yang G. Chem. Commun., 2006, 45：4700. [7] Wang W Y, Yang Z Y, Wang C J, et al. Cryst. Eng. Comm., 2011, 13: 4895. [8] Yi X Y, Fang H C, Gu Z G, et al. Crystal Growth & Design, 2011, 11: 2824. [9] Nie C Y, Zhang Q, Ding H J, et al. Dalton Trans., 2014, 4: 599. [10] Shelxtl N T. 1999. Crystal Structure Analysis Package, Version 5.10, Bruker AXS, Analytical X-Ray System, Madison, WI. [11] Zhu L C, Zhao Y, Yu S J, et al. Inorg. Chem. Commun., 2010, 13: 1299. [12] Hou G F, Wang X D, Yu Y H, et al. Cryst. Eng. Comm., 2013, 15: 249. [13] Fu Y M, Zhao Y H, Lan Y Q, et al. J. Solid State Chem., 2008, 181: 2378. [14] Wang X M, Qiang L S, Fan R Q, et al. Supramolecular Chemistry, 2013, 25: 416. [15] Moore E G, Zigethy G S, Xu J D, et al. Angew. Chem. Int. Ed., 2008, 47: 9500.
