1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3-Hbpt) as ligand in Cd(II) complexes: synthesis, crystal structures, and fluorescence

Hydrothermal reactions of 1H-3-(2-pyridyl)-5-(3-pyridyl)-1,2,4-triazole (2,3-Hbpt) with CdCl2 and CdI2 yielded three new coordination polymers, {[CdCl(2,3-bpt)(H2O)]2H(2)O}(n) (1), {[Cd2I3(2,3-H(0.5)bpt)(2)]}(n) (2), and [CdI3(2,3-Hbpt)](2,3-H(2)bpt)H2O (3). Structural analysis reveals that 1 has a 1-D double chain structure; in 2, 2,3-bpt bridges adjacent Cd(II) ions to form a 1-D twofold helical chain, which further connects via (2)-I-, giving a 2-D grid structure in the ab plane; 3 is mononuclear. These complexes are further connected through weak hydrogen bonding interactions, and/or weak stacking interactions, to generate 3-D supramolecular structures. The fluorescence properties of 1 and 2 have been investigated in the solid state at room temperature.