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

Three Zn-triazolate-dicarboxylate 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, CO 2, and CH 4 sorption experiments. Because 3 has exposed amino groups and distinct pore shape, it has the highest CO 2 uptake and CO 2 /N 2 and CO 2 /CH 4 selectivities at 273 K.