Novel Structural Diversity of Triazolate-Based Coordination Polymers Generated Solvothermally with Anions

Five novel d10 metal coordination polymers, {[Cd3(trz)5(Br)]·H2O}n (1), [Cd2(trz)3(NO3)(H2O)]n (2), [Cd(Htrz)(SO4)(H2O)]n (3), [Zn2(trz)2(NO3)2(H2O)]n (4), and [Zn2(Htrz)2(SO4)2]n (5) (Htrz = 1,2,4-triazole), have been synthesized through in situ solvothermal decarboxylation reactions using 1H-1,2,4-triazole-3-carboxylic acid and cadmium/zinc salts as starting materials. The X-ray crystallographic analyses demonstrate the two-dimensional structure of complex 4 and three-dimensional ones of complexes 1−3 and 5. The Htrz ligands adopt the μ1,2,4-bridging mode in complexes 1 and 2 and μ2,4-bridging mode in complex 3. Complex 5 represents the first example of metal/triazolate complexes, in which the neutral Htrz ligands act as both μ1,2 and μ2,4 bridges. The diversity of architectures of these complexes reveals that anions play important roles in the self-assembly process under in situ solvothermal conditions. The possible mechanism of decarboxylation is discussed, and the thermal stability and fluorescent properties of these complexes are reported briefly.