Three 1-(4-Hydroxyphenyl)-1h-1,2,4-Triazole-Based Cd(Ii) Coordination Polymers Directed By Aromatic Polycarboxylate Coligands

The reactions of 1-(4-hydroxyphenyl)-1H-1,2,4-triazole (hptrz) and inorganic Cd(II) salts with different aromatic polycarboxylic acids in mixed-solvent led to the formation of three new crystalline coordination polymers, {[Cd(H2O)(2)(hptrz)(Hbtc)](n)center dot CH3OH center dot H2O} 1, [Cd-2(H2O)(2)(hptrz)(2)(tp)(2)](n) 2, and {[Cd(H2O)(2)(hptrz)-(OH-ip)](n)center dot DMF center dot H2O} 3 (H(3)btc = 1,3,5-benzenetricarboxylic acid, H(2)tp = terephthalic acid, and OH-H(2)ip = 5-hydroxyisophthalic acid), which were fully characterized by elemental analysis, IR spectroscopy, single crystal X-ray crystallography, thermogravimertric analysis and luminescence spectra. Structure determination revealed that one-dimensional (1-D) polymeric chains for 1 and 3, and 2-D layered structure for 2 are significantly directed by the coordination mode of the carboxylate groups from aromatic coligands. In contrast, the terminal hptrz ligand affords its uncoordinated phenolic OH group to form classical H-bond interactions with coordinated water and/or carboxylate groups, which are responsible for the fori-nation of 3-D supramolecular networks. In addition, the three solid coordination polymers with considerable thermal stability present strong hptrz-based fluorescence emissions at room temperature.