Porous imine-based networks with protonated imine linkages for carbon dioxide separation from mixtures with nitrogen and methane
Porous imine-based networks with protonated imine linkages for carbon dioxide separation from mixtures with nitrogen and methane
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DOI：
10.1039/c5ta02504d
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发表时间：
2015-01-01
影响因子：
11.9
通讯作者：
Senker, Juergen
中科院分区：
文献类型：
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作者：
Popp, Nadine;Homburg, Thomas;Senker, Juergen
用2，4，6-(4-氨基苯基)-1，3，5-三嗪与9，10-蒽二甲醛(Pin1和Pin1_2)和4，4‘，4’‘，4’‘-亚甲基苯甲醛(PIN2)在无催化剂条件下进行席夫碱缩合反应，制备了多孔亚胺连接网络(PINs)。即使在合成优化后，也只得到了DMSO(Pin1和PIN2)的微孔骨架，而DMF(Pin1_2)和其他溶剂导致了无孔体系，由Ar测量估计。此外，N-15固体核磁共振和红外光谱揭示了DMSO分解产物的影响，导致了亚胺键的质子化，并导致了含有磺酸反离子的离子结构。到目前为止，文献中还没有讨论由于使用DMSO作为溶剂而导致的亚胺功能的质子化。相反，对于Pin1_2，亚胺键保持中性。PIN1和PIN2的Ar吸附等温线分别为458m(2)g(-1)和325m(2)g(-1)，孔结构为微孔和小孔，孔径为0.6~5 nm。此外，在273K下的CO2等温线显示，三种聚合物的超微孔具有相似的孔径分布。尽管它们的网络结构不同，但获得了相似的CO2吸收(在273K，1.0bar时为1.8-1.06 mmolg(-1))和30kJ摩尔(-1)的吸附热Q(St)。与PIN1和PIN2的多离子性质一致，这两种化合物在室温下对水的吸附量都是疏水性较强的中性PIN1_2的三倍，说明了两种不同的吸附机制。最后的选择性计算显示了良好的CO2/N-2(30-31)和CO2/CH4(8-12)选择性因子。尽管具有中等的BET表面积，但PIN表现出良好的二氧化碳吸收和选择性系数。
Porous imine-linked networks (PINs) have been prepared by catalyst-free Schiff base condensation of 2,4,6-(4-aminophenyl)1,3,5-triazine with 9,10-anthracene-dicarboxaldehyde (PIN1 and PIN1_2) and with 4,4',4 '',4 '''-methanetetrakis-benzaldehyde (PIN2). Even after synthesis optimisation, only with DMSO (PIN1 and PIN2) microporous frameworks were obtained, whereas DMF (PIN1_2) and other solvents led to nonporous systems, estimated by argon measurements. Furthermore, N-15 solid state NMR and IR spectroscopy reveal the influence of the decomposition products of DMSO leading to protonation of the imine linkage and resulting in an ionic structure with an incorporated sulfonic counterion. Until now, protonation of an imine function due to the usage of DMSO as solvent has not been discussed in the literature. In contrast, for PIN1_2 the imine linkage remains neutral. Argon sorption isotherms for PIN1 and PIN2 exhibit surface areas of 458 m(2) g(-1) nd 325 m(2) g(-1) and the pore structure displays micro-and small mesopores with pore diameters from 0.6 to 5 nm. Additionally, CO2 isotherms at 273 K demonstrate ultramicropores for all three polymers with similar pore size distributions. Despite their different network structures, similar CO2 uptakes (1.8-1.06 mmol g(-1) at 273 K at 1.0 bar) and heat of adsorption Q(st) values of 30 kJ mol(-1) were obtained. In line with the polyionic character of PIN1 and PIN2, both compounds adsorb three times more water than the more hydrophobic, neutral PIN1_2 at room temperature indicating two different adsorption mechanisms. IAST selectivity calculations show good CO2/N-2 (30-31) and CO2/CH4 (8-12) selectivity factors. Despite their moderate BET-surface areas, the PINs show good CO2 uptakes and selectivity factors.