Guest-Induced Switchable Breathing Behavior in a Flexible Metal-Organic Framework with Pronounced Negative Gas Pressure

Yi-Xiang Shi; Wu-Xiang Li; Wen-Hua Zhang; Jian-Ping Lang

doi:10.1021/acs.inorgchem.8b01408

Guest-Induced Switchable Breathing Behavior in a Flexible Metal-Organic Framework with Pronounced Negative Gas Pressure

Inorg Chem. 2018 Jul 16;57(14):8627-8633. doi: 10.1021/acs.inorgchem.8b01408. Epub 2018 Jun 29.

Authors

Yi-Xiang Shi¹, Wu-Xiang Li¹, Wen-Hua Zhang¹, Jian-Ping Lang^{1

2}

Affiliations

¹ College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , Jiangsu , PR China.
² State Key Laboratory of Organometallic Chemistry , Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , Shanghai 200032 , PR China.

PMID: 29956934
DOI: 10.1021/acs.inorgchem.8b01408

Abstract

Flexible metal-organic frameworks (MOFs) have attracted great interest for their dynamically structural transformability in response to external stimuli. Herein, we report a switchable "breathing" or "gate-opening" behavior associated with the phase transformation between a narrow pore (np) and a large pore (lp) in a flexible pillared-layered MOF, denoted as MOF-1 as, which is also confirmed by SCXRD and PXRD. The desolvated phase (MOF-1 des) features a unique stepwise adsorption isotherm for N₂ coupled with a pronounced negative gas adsorption pressure. For comparison, however, no appreciable CO₂ adsorption and gate-opening phenomenon with stepwise sorption can be observed. Furthermore, the polar micropore walls decorated with thiophene groups in MOF-1 des reveals the selective sorption of toluene over benzene and p-xylene associated with self-structural adjustment in spite of the markedly similar physicochemical properties of these vapor molecules.