A Hydrogen‐Bonded yet Hydrophobic Porous Molecular Crystal for Molecular‐Sieving‐like Separation of Butane and Isobutane. (7th October 2020)

• Record Type: Journal Article
• Authors: Ye, Zi‐Ming; Zhang, Xue‐Wen; Liao, Pei‐Qin; Xie, Yi; Xu, Yan‐Tong; Zhang, Xue‐Feng; Wang, Chao; Liu, De‐Xuan; Huang, Ning‐Yu; Qiu, Ze‐Hao; Zhou, Dong‐Dong; He, Chun‐Ting; Zhang, Jie‐Peng
• Is Part Of: Angewandte Chemie. Volume 132:Number 51(2020)
• Page Start: 23522
• Page End: 23528
• Publication Date: 2020-10-07
• Subjects: adsorptive separation -- hydrogen-bonded organic frameworks (HOFs) -- hydrophobicity -- molecular sieve -- single-crystal-to-single-crystal; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202011300
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Porous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen‐bonded cyclic dinuclear Ag I complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2–13. The seemingly rigid adsorbent shows a pore‐opening or nonporous‐to‐porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving. Quantitative column breakthrough experiments show slight co‐adsorption of isobutane with an experimental butane/isobutane selectivity of 23, and isobutane can be purified more efficiently than for butane. In situ powder/single‐crystal X‐ray diffraction and computational simulations reveal that a trivial guest‐induced structural transformation plays a critical role. Abstract : A rigid hydrogen‐bonded porous molecular crystal shows not only exceptionally high hydrophobicity and chemical stability, but also molecular‐sieving‐like separation of butane/isobutane associated with a trivial guest‐induced structural transformation revealed by powder/single‐crystal X‐ray diffraction and computational simulations.