摘要:
Two novel metal-organic coordination polymers with the formulas [Zn(btdc)(2,2'-bpy)](n) (1) and {[Cd-2(btdc)(2)(2,2'-bpy)]center dot DMF}(n) (2) have been solvothermally synthesized by the assembly of mixed ligands, H(2)btdc and 2,2'-bpy with Zn(NO3)(2)center dot 6H(2)O and Cd(NO3)(2)center dot 4H(2)O, respectively, where H(2)btdc = 2,2'-bithiophene-5,5'-dicarboxylic acid, 2,2'-bpy = 2,2'-bipyridine, and DMF = N,N'-dimethylformamide. Complex 1 is composed with one-dimensional (1D) infinite zigzag polymeric coordination chains, which are further stacked into 3D supramolecular architecture by pi-pi stacking interaction. Complex 2 possesses 2D layers with the thickness about 1.2 nm, these layers forming a 3D network through pi-pi stacking interactions. In complex 1, the btdc ligand exists in stable trans conformation and the conformation of btdc ligand in complex 2 is of both trans and cis. Furthermore, these two complexes show enhanced fluorescent emission in comparison with H(2)btdc ligand. (C) 2011 Elsevier B. V. All rights reserved.