title: Sizable dynamics in small pores: CO2location and motion in the α-Mg formate metal-organic framework.
abstract: Metal-organic frameworks (MOFs) are promising materials for carbon dioxide (CO2) adsorption and storage; however, many details regarding CO2dynamics and specific adsorption site locations within MOFs remain unknown, restricting the practical uses of MOFs for CO2capture. The intriguing α-magnesium formate (α-Mg3(HCOO)6) MOF can adsorb CO2and features a small pore size. Using an intertwined approach of13C solid-state NMR (SSNMR) spectroscopy,1H-13C cross-polarization SSNMR, and computational molecular dynamics (MD) simulations, new physical insights and a rich variety of information have been uncovered regarding CO2adsorption in this MOF, including the surprising suggestion that CO2motion is restricted at elevated temperatures. Guest CO2molecules undergo a combined localized rotational wobbling and non-localized twofold jumping between adsorption sites. MD simulations and SSNMR experiments accurately locate the CO2adsorption sites; the mechanism behind CO2adsorption is the distant interaction between the hydrogen atom of the MOF formate linker and a guest CO2oxygen atom, which are ca. 3.2 Å apart.
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. yhuang@uwo.ca.
authors.forename: Yuanjun
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. yhuang@uwo.ca.
authors.forename: Bryan E G
authors.initials: BE
authors.lastname: Lucier
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. yhuang@uwo.ca.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, P. R. China and National Energy Center for Coal to Clean Fuels, Synfuels China Co., Ltd, Huairou District, Beijing, 101400, P. R. China.
authors.forename: Pengju
authors.initials: P
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan 430071, P. R. China.
authors.forename: Anmin
authors.initials: A
authors.lastname: Zheng
authors.affiliation: Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada. yhuang@uwo.ca.
authors.forename: Yining
authors.initials: Y
authors.lastname: Huang