Polymeric frameworks constructed from a metal-organic coordination compound, in 1-D and 2-D systems: Synthesis, crystal structures, and fluorescent properties

Three novel metal-organic coordination polymers, Cd(BDC)(phen)(2)(.)(C2H5OH)(H2O) (1) (H2BDC = benzene-1,4-dicarboxylic acid), Cd(1,3-BDC)(phen) (2) (1,3-H2BDC = benzene- 1,3-dicarboxylic acid), and Cd-2(fma)2(phen)2 (3) (H(2)fma = fumaric acid), have been synthesized by using the metal-organic coordination compound Cd(phen)(2)(NO3)(2) as the metal source instead of metal salts under different conditions. Compound 1 is a 1-D zig-ag chain. The presence of two phen ligands chelating to one cadmium atom in 1, which is rare in similar polymers because of the severe steric hindrance for bulky phen groups, is mainly due to these two phen ligands entirely coming from metal source Cd(phen)(2)(NO3)(2). Compound 2 is an interesting twisted double chain with a 1-D channel along the c axis, which crystallizes in a monoclinic system, P-2/c space group. And compound 3 is a 2-D undulating network, in which fma ligands adopt three different coordination fashions. Additionally, these three compounds show strong fluorescence in the solid state at room temperature.