Constructions of two photoluminescent 3D coordination polymers comprising of hydroxide-bridged cadmium chain and polynuclear cadmium macrocycle using phenylsuccinic acid

Two new coordination polymers [Cd5(OH)2(psa)4(bpe)(H2O)2]n (1) and [Cd5(psa)5(bpp)(H2O)2]n (2) (H2psa = phenylsuccinic acid, bpe = 1,2-bis(4-pyridyl)ethylene, bpp = 1,3-bis(4-pyridyl)propane) have been synthesized by methods of hydrothermal reaction and their crystal structures determined. In 1, psa ligands act as changeable bridges bound to Cd atoms, resulting in the formation of a sublayer based on cadmium hydroxide chains comprising of Cd5(OH)2 units. The adjacent layers are pillared by bpe linkers forming a 3D condensed structure. 2 has a 3D structure based on cadmium carboxylate sublayer with polynuclear cadmium macrocycles, pillared by bpp ligands. The structure versatility indicates that the phenyl side groups of psa ligands play a crucial role in modulating the cluster-based coordination polymers. A discussion of the crystal structures, as well as the coordination behavior of psa ligand is provided. IR, elemental analysis and XRPD confirmed the phase purity of the bulk materials. The photoluminescent properties of 1 and2 in the solid state are also investigated.