New Zn-Aminotriazolate-Dicarboxylate Frameworks: Synthesis, Structures, and Adsorption Properties

Three Zn-triazolate-ditarboxylate frameworks, namely, [Zn-2(atz)(2)(ipa)] (1, Hatz = 3-amino-1,2,4-triazole, H(2)ipa = isophthalic acid), [Zn-2(datz)(2)(ipa)] (2, Hdatz = 3,5-diamino-1,2,4-triazole), and [Zn-2(atz)(2)(oba)] (3, H(2)oba = 4,4'-oxobisbenzoic acid), have been synthesized by solvothermal reactions Crystal-structure analyses demonstrated that 1-3 are isoreticular three-dimensional porous structures consisting of Zn-triazolate layers and dicarboxylate pillars. The major differences of three compounds are the lengths. and orientations of the pillars: Thermogravimetry analyses and powder X-ray diffraction measurements showed that 1-3 have high thermal stability and good water stability. The adsorption properties of 1-3 were investigated. by N-2, CO2, and CH4 sorption experiments. Because 3 has exposed,amino groups and distinct pore shape, it has the highest CO2 uptake and CO2/N-2 and CO2/CH4 selectivities at 273 K.