Synthesis, Crystal Structure, and Photoluminescent Properties of Ternary Cd(II)/Triazolate/Chloride System

Solvothermal reactions of cadmium chloride and 1,2,4-triazole (Htrz) in different solvent mediums have successfully synthesized five ternary Cd(II)/trz/Cl- complexes, [Cd(trz)Cl]center dot H2O (1 center dot H2O), [Cd-4(trz)(5)Cl-3(H2O)]center dot(THF)(1.25) (H2O)(2.5) (2 center dot 1.25THF center dot 2.5H(2)O), [Cd-3(trz)(2)Cl(MeCN)] (3), [Cd-3(trz)(4)Cl-2] center dot (H2O)(0.5) (4 center dot 0.5H(2)O), and [Cd-4(trz)(6)Cl-2-(H2O)0.5] center dot (H2O)(3.5) (5 center dot 3.5H(2)O). All of these five coordination polymers have three-dimensional (3-D) structural features, which are constructed by distinct substructures including clusters, chains, rings, and even 3-D frameworks. In all cases, 1,2,4-triazolate adopts a mu(1,2,4), bridging mode, and chloride ions display a,mu(2), mu(3), mu(4) bridging mode, respectively, which makes the structural diversity in the assembling system, for example, mu(4)-Cl and cadmium triazolate, build up an unprecedented tetranuclear cluster [Cd-4(trz)(8)Cl](-) in 2. All of the materials exhibit intense blue fluorescent emission and high thermal stability, wherein 1 presents an interesting guest-responsive photoluminescent property.