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)]·2H2O}n (1), {[Cd2I3(2,3′-H0.5bpt)2]}n (2), and [CdI3(2,3′-Hbpt)](2,3′-H2bpt)·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 μ2-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 π···π 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.