Spatiotemporal Design of the Metal–Organic Framework DUT‐8(M). Issue 8 (27th December 2022)

• Record Type: Journal Article
• Authors: Miura, Hiroki; Bon, Volodymyr; Senkovska, Irena; Ehrling, Sebastian; Bönisch, Nadine; Mäder, Gerrit; Grünzner, Stefan; Khadiev, Azat; Novikov, Dmitri; Maity, Kartik; Richter, Andreas; Kaskel, Stefan
• Is Part Of: Advanced materials. Volume 35:Issue 8(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-27
• Subjects: metal–organic frameworks -- nucleation -- porous materials -- spatiotemporal engineering -- stimuli‐responsive materials; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202207741
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Switchable metal–organic frameworks (MOFs) change their structure in time and selectively open their pores adsorbing guest molecules, leading to highly selective separation, pressure amplification, sensing, and actuation applications. The 3D engineering of MOFs has reached a high level of maturity, but spatiotemporal evolution opens a new perspective toward engineering materials in the 4th dimension (time) by t ‐axis design, in essence exploiting the deliberate tuning of activation barriers. This work demonstrates the first example in which an explicit temporal engineering of a switchable MOF (DUT‐8, [M1 M2 (2, 6‐ndc)2 dabco] n, 2, 6‐ndc = 2, 6‐naphthalene dicarboxylate, dabco = 1, 4diazabicyclo[2.2.2]octane, M1 = Ni, M2 = Co) is presented. The temporal response is deliberately tuned by variations in cobalt content. A spectrum of advanced analytical methods is presented for analyzing the switching kinetics stimulated by vapor adsorption using in situ time‐resolved techniques ranging from ensemble adsorption and advanced synchrotron X‐ray diffraction experiments to individual crystal analysis. A novel analysis technique based on microscopic observation of individual crystals in a microfluidic channel reveals the lowest limit for adsorption switching reported so far. Differences in the spatiotemporal response of crystal ensembles originate from an induction time that varies statistically and widens characteristically with increasing cobalt content reflecting increasing activation barriers. Abstract : A pillared layer metal–organic frameworks can be tuned along a time axis by adjusting the ratio of nickel and cobalt in the paddle wheel node. Advanced in situ methodologies reveal switching rates ranging from 1 to 200 s. Individual crystal observations in a microfluidic device reveal prolonged induction time in particular for highly cobalt substituted frameworks.