Coordination-directed one-dimensional coordination polymers generated from a new unsymmetrical oxadiazole bridging ligand and transition metal ions

Three one-dimensional coordination polymers, namely [ZnL2(NO3)2]n (1), [CdL2(NO3)2]n (2) and {[ZnL2(H2O)2](ClO4)2•2L•2(H2O)}n (3), have been successfully synthesized based on a new unsymmetrical oxadiazole bridging ligand 2-[2-((3-pyridyl)methoxy)phenyl]-5-[(4-pyridyl)]-1,3,4-oxadiazole (L). Compounds 1–3 feature a similar one-dimensional infinite chain that consists of M2L2 building block (M = Zn(II) and Cd(II)). In 3, the uncoordinated L ligands are located between the [M2L2]n chains and serve as the agents to cross-link the chains by weak π–π and H-bonding interactions into a 2D network. In addition, the luminescent properties of L and 1–3 were primarily investigated in the solid state.