A 3D photoluminescent Cd(II) polymer based on mixed 3,5-bis-oxyacetate-benzoic acid and rigid bis(imidazole) ligands with an unusual (4,8)-connected topology

The hydrothermal reaction of CdCl2·2.5H2O with 3,5-bis-oxyacetate-benzoic acid (H3BOABA) and 4,4′-bis(1-imidazolyl)biphenyl (L) generates a new three-dimensional (3D) coordination polymer, {[Cd2(BOABA)(L)(μ3-OH)]2·3H2O}n (1). In 1, the Cd(II) centers are connected by carboxylate and μ3-OH bridges into Cd-O-C rod-like secondary building units (SBUs) which are further linked by BOABA3 − and L ligands into the 3D framework. Two types of irregular rhombic channels occupied by free water molecules were observed in the framework. And the topology analysis suggests an unusual (4,8)-connected net for 1. Furthermore, the thermal and photoluminescent properties of 1 have also been studied.