Synthesis, crystal structure, and luminescent properties of two coordination polymers based on 1,4-phenylenediacetic acid

Two coordination polymers [Zn(pda)(bib)]n (1) and [Cd(pda)0.5(bib)Cl]n (2)] have been synthesized by using Zn(II)/Cd(II) salts with two flexible ligands pda and bib under hydrothermal conditions. Due to the coordination geometry around the metal ions and the diverse coordination modes of the flexible ligands, the obtained complex show diverse structures. In the structure of 1, a pair of bib ligands connect two Zn(II) atoms give rise a 22-membered ring, which is further extended by pda ligands in bidentate coordination mode leading a ring-containing 2D layer. In 2, bib ligands join [Cd2Cl2]2+ dimmers generate 1D polymeric ribbon, the pda ligands further extend such ribbon forming a 2D layer network containing rectangular windows. In additional, luminescent properties of two complexes have also been studied, they could be potential fluorescence materials.279