A series of entangled Cd(II) coordination polymers assembled from different dicarboxylate acids and a flexible imidazole-based ligand

• Published in: Polyhedron 2015-03, Vol.89, p.20-28
• Main Authors: Mu, Ya-Juan, Xie, Ji-Xing, Ran, Yun-Gen, Han, Bo, Qin, Gui-Fang
• Format: Article
• Language: English
• Subjects: Cd(II) coordination polymers; Dicarboxylate acids; Entangled coordination polymers; Flexible imidazole-based ligands; Photoluminescent properties
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2014.12.029

Four architectures with different entangled modes have been obtained by introducing dicarboxylate co-ligands into the Cd(II)-bmimx system. Their structures have been analyzed. In addition, the thermal stability and photoluminescent properties of complexes 1–4 have also been investigated. [Display omitted] In order to tune the architectures of Cd(II)-bmimx coordination polymers (bmimx=1,4-bis(2-methylimidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene), four dicarboxylate ligands, succinic acid (H2suc), 1,4-benzenedicarboxylic acid (H2bdc), 4,4′-sulfonyldibenzoic acid (H2sdba) and 4,4′-carbonyldibenzoic acid (H2cba), have been employed as co-ligands, and four new coordination polymers with different entangled modes, namely {[Cd(bmimx)(suc)]·2H2O}n (1), [Cd(bmimx)(bdc)(H2O)]n (2), [Cd(bmimx)(sdba)]n (3) and {[Cd(bmimx)(cba)]·8H2O}n (4), have been synthesized and characterized. Complexes 1 and 2 show the dia topology with the 4- and 5-fold interpenetrating modes, respectively. Complexes 3 and 4 exhibit different 2D+2D→3D polycatenated networks via Hopf links, respectively. A comparison of these structures reveals that the backbones of the dicarboxylate ligands play important roles in controlling the entangled modes of the coordination polymers. Furthermore, the thermal stabilities and the photoluminescence of 1–4 have also been investigated.