Molecular Sieving of C2‐C3 Alkene from Alkyne with Tuned Threshold Pressure in Robust Layered Metal–Organic Frameworks. Issue 31 (28th May 2020)

• Record Type: Journal Article
• Authors: Ke, Tian; Wang, Qingju; Shen, Jin; Zhou, Jingyi; Bao, Zongbi; Yang, Qiwei; Ren, Qilong
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 31(2020)
• Page Start: 12725
• Page End: 12730
• Publication Date: 2020-05-28
• Subjects: adsorption -- alkenes -- metal–organic frameworks -- molecular sieving -- separation; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202003421
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: C2 ‐C3 alkyne/alkene separation is of great importance; however, designing materials for an efficient molecular sieving of alkenes from alkynes remains challenging. Now, two hydrolytically stable layered MOFs, [Cu(dps)2 (GeF6 )] (GeFSIX‐dps‐Cu, dps=4, 4′‐dipyridylsulfide) and [Zn(dps)2 (GeF6 )] (GeFSIX‐dps‐Zn), can achieve almost complete exclusion of both C3 H6 and C2 H4 from their alkyne analogues. GeFSIX‐dps‐Cu displays a notable advanced threshold pressure for alkynes adsorption and thus substantial uptakes at lower pressures, providing record C3 H4 /C3 H6 uptake ratios and capacity‐enhanced C2 H2 /C2 H4 sieving for a wide composition range. Metal substitution (Zn to Cu) affords fine tuning of linker rotation and layer stacking, creating slightly expanded pore aperture and interlayer space coupled with multiple hydrogen‐bonding sites, allowing easier entrance of alkyne while excluding alkene. Breakthrough experiments confirmed tunable sieving by these MOFs for C3 H4 /C3 H6 and C2 H2 /C2 H4 mixtures. Abstract : A fine tuning of linker rotation and layer stacking in hydrolytically stable layered MOFs via metal substitution creates optimal expanded pore aperture and interlayer space coupled with multiple binding sites. It affords almost complete exclusion of C2 ‐C3 alkenes from alkynes with substantial alkyne uptake and record C3 H4 /C3 H6 uptake ratios in a wide pressure range.