Syntheses,Structures and Luminescent Properties of Cd(Ⅱ)/Zn(Ⅱ) Coordination Polymers Based on the Flexible 4-Substituted Bis(1,2,4-triazole) Ligand

Two new cadmium(Ⅱ) and zinc(Ⅱ) coordination polymers, {Cd(btre)0.5-(mip)(H_2O)_2]·H_2O}n(1) and Zn(btre)(mip)]n(2), were synthesized at room temperature condition and characterized by IR spectra, elemental analyses, single-crystal and powder X-ray diffractions(btre = 1,2-bis(1,2,4-triazol-4-yl)ethane, H2 mip = 5-methyl-1,3-benzenedicarboxylic acid). Complex 1 belongs to the triclinic system, P1 space group, with a = 8.9830(6), b = 10.0579(6), c = 10.2479(9) ?, α = 98.837(6), β = 115.975(8), γ = 106.370(6)°, V = 756.30(11) ?~3 and Z = 2; complex 2 crystallizes in monoclinic, space group P21/c, with a = 7.0332(3), b = 14.9947(7), c = 15.9689(7) ?, β = 97.1170(10)°, V = 1671.12(13) ?~3 and Z = 4. Compounds 1 and 2 based on the same N/O-donor ligands show different structures. The one-dimensional chains of 1 are further linked by hydrogen bonding and π-π interactions to yield a three-dimensional supramolecular structure. The two-dimensional(6,3) networks of 2 are further extended into a 3D framework via π-π interactions. Thermal stabilities and luminescence of 1 and 2 were investigated.