Hydrothermal synthesis, structure, and luminescent properties of selected Zn(II)/Cd(II) coordination polymers constructed from 3,5-bis(x-pyridyl)-1,2,4-triazole (x=3, 4)

Utilizing 3,5-bis(x-pyridyl)-1,2,4-triazole (x-Hpytz, x = 3; x = 4) as multidentate ligands, six novel coordination polymers with Zn(II) or Cd(II) metal ions were prepared: [Zn(3-pytz)(0.5)(OH)(0.5)Cl](n) (1, 1D ladder), {[Zn(3-Hpytz)(H2O)(4)] [Zn(3-Hpytz)(H2O)(3)center dot SO4]SO4 center dot 5H(2)O}(n) (2 center dot 5H(2)O, 1D chain), [Cd(3-Hpytz)(SO4)](n) (3, 3D framework), {[Cd(3-Hyptz)SO4 center dot 3H(2)O]center dot 2H(2)O}(n) (4 center dot 2H(2)O, 1D chain), [Zn(4-pytz)Cl](n) (5, 3D framework) and [Zn-2(4-pytz)(SO4)(OH)](n) (6, 3D framework). All compounds were obtained from hydrothermal reactions, with the exception of compound 4 which was obtained by solvent diffusion at room temperature. All compounds were characterized by FTIR, elemental analysis and TGA analysis and their structures were determined by X-ray diffraction. All compounds exhibited substantial thermal stability and showed photofluorescent properties that resulted from ligand pi-pi* transition.