title: A Computational and Experimental Approach Linking Disorder, High-Pressure Behavior, and Mechanical Properties in UiO Frameworks.
abstract: Whilst many metal-organic frameworks possess the chemical stability needed to be used as functional materials, they often lack the physical strength required for industrial applications. Herein, we have investigated the mechanical properties of two UiO-topology Zr-MOFs, the planar UiO-67 ([Zr6O4(OH)4 (bpdc)6], bpdc: 4,4'-biphenyl dicarboxylate) and UiO-abdc ([Zr6O4(OH)4 (abdc)6], abdc: 4,4'-azobenzene dicarboxylate) by single-crystal nanoindentation, high-pressure X-ray diffraction, density functional theory calculations, and first-principles molecular dynamics. On increasing pressure, both UiO-67 and UiO-abdc were found to be incompressible when filled with methanol molecules within a diamond anvil cell. Stabilization in both cases is attributed to dynamical linker disorder. The diazo-linker of UiO-abdc possesses local site disorder, which, in conjunction with its longer nature, also decreases the capacity of the framework to compress and stabilizes it against direct compression, compared to UiO-67, characterized by a large elastic modulus. The use of non-linear linkers in the synthesis of UiO-MOFs therefore creates MOFs that have more rigid mechanical properties over a larger pressure range.
authors.affiliation: EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Joseph Black Building, Edinburgh, EH9 3FJ, UK.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Hobday
authors.affiliation: WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Marshall
authors.affiliation: WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
authors.forename: Colin F
authors.initials: CF
authors.lastname: Murphie
authors.affiliation: EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Joseph Black Building, Edinburgh, EH9 3FJ, UK.
authors.forename: Jorge
authors.initials: J
authors.lastname: Sotelo
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge, CB3 0FS, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Richards
authors.affiliation: Diamond Light Source, Harwell Campus, Didcot, OX11 ODE, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Allan
authors.affiliation: Department of Chemical Engineering, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
authors.forename: Tina
authors.initials: T
authors.lastname: Düren
authors.affiliation: Chimie ParisTech, PSL Research University, CNRS, Institut de Recherche de Chimie, 75005, Paris, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Coudert
authors.affiliation: WestCHEM, School of Chemistry, The University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK. ross.forgan@glasgow.ac.uk.
authors.forename: Ross S
authors.initials: RS
authors.lastname: Forgan
authors.affiliation: EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Joseph Black Building, Edinburgh, EH9 3FJ, UK. Carole.Morrison@ed.ac.uk.
authors.forename: Carole A
authors.initials: CA
authors.lastname: Morrison
authors.affiliation: EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, David Brewster Road, Joseph Black Building, Edinburgh, EH9 3FJ, UK. smoggach@staffmail.ed.ac.uk.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Moggach
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, Charles Babbage Road, Cambridge, CB3 0FS, UK. tdb35@cam.ac.uk.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bennett
keywords: X-ray crystallography; gas separation; high-pressure chemistry; metal-organic frameworks; structure elucidation