Single- and Double-Layer Structures and Sorption Properties of Two Microporous Metal–Organic Frameworks with Flexible Tritopic Ligand
journal contributionposted on 03.04.2013, 00:00 by Liqin Han, Yan Yan, Fuxing Sun, Kun Cai, Tsolmon Borjigin, Xiaojun Zhao, Fengyu Qu, Guangshan Zhu
Two 2D multifunctional microporous metal–organic frameworks, [Cd3(L)2(H2O)6]·1.5H2O·2EtOH·DMF (1, H3L = 2,4,6-tris-(4-carboxyphenoxy)-1,3,5-triazine) and [Zn3(L)2(H2O)2]·3H2O·TEA·2DMF (2), with single- and double-(6,3)-layer structures, respectively, have been synthesized by the reaction of Cd(Zn) nitrate with H3L in a mixed solvent of DMF, ethanol, and H2O. TGA and PXRD analysis showed that compounds 1 and 2 were thermally stable up to 250 °C. Gas sorption measurement indicates that compounds 1 and 2 exhibited selective sorption capabilities for CO2 over CH4 and N2 and could adsorb considerable amounts of H2 at low temperature. These two compounds also showed high sorption capabilities for water, methanol, and ethanol vapors. The highest adsorption amounts of compounds 1 and 2 are 168.8 and 257.3 cc/g for H2O, 175.1 and 140.8 cc/g for methanol, and 91.7 and 76.2 cc/g for ethanol, respectively. Furthermore, the maximum luminescence emission peaks of compounds 1 and 2 exhibit blue shifts of 138 and 132 nm, respectively, compared to the free ligand.