Selective Gas Adsorption in a Pair of Robust Isostructural MOFs Differing in Framework Charge and Anion Loading

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• 作者：Matthew G. Cowan ; Reece G. Miller ; Peter D. Southon ; Jason R. Price ; Ozgur Yazaydin ; Joseph R. Lane ; Cameron J. Kepert ; Sally Brooker
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：November 17, 2014
• 年：2014
• 卷：53
• 期：22
• 页码：12076-12083
• 全文大小：514K
• ISSN：1520-510X

文摘

Activation of the secondary assembly instructions in the mononuclear pyrazine imide complexes [Co^III(dpzca)₂](BF₄) or [Co^II(dpzca)₂] and [Ni^II(dpzca)₂] has facilitated the construction of two robust nanoporous three-dimensional coordination polymers, [Co^III(dpzca)₂Ag](BF₄)₂路2(H₂O) [1路2(H₂O)] and [Ni^II(dpzca)₂Ag]BF₄路0.5(acetone) [2路0.5(acetone)]. Despite the difference in charge distribution and anion loading, the framework structures of 1路2(H₂O) and 2路0.5(acetone) are isostructural. One dimensional channels along the b-axis permeate the structures and contain the tetrafluoroborate counterions (the Co^III-based MOF has twice as many BF₄^{鈥?/sup> anions as the NiII-based MOF) and guest solvent molecules. These anions are not readily exchanged whereas the solvent molecules can be reversibly removed and replaced. The H₂, N₂, CO₂, CH₄, H₂O, CH₃OH, and CH₃CN sorption behaviors of the evacuated frameworks 1 and 2 at 298 K have been studied, and modeled, and both show very high selectivity for CO₂ over N₂. The increased anion loading in the channels of CoIII-based MOF 1 relative to NiII-based MOF 2 results in increased selectivity for CO₂ over N₂ but a decrease in the sorption kinetics and storage capacity of the framework.}