title: Connecting defects and amorphization in UiO-66  and MIL-140 metal–organic frameworks: a  combined experimental and computational study.
abstract: The mechanism and products of the structural collapse of the metal–organic frameworks (MOFs) UiO-66, MIL-140B and MIL-140C upon ball-milling are investigated through solid state 13C NMR and pair distribution function (PDF) studies, finding amorphization to proceed by the breaking of a fraction of metal–ligand bonding in each case. The amorphous products contain inorganic–organic bonding motifs reminiscent of the crystalline phases. Whilst the inorganic Zr6O4(OH)4 clusters of UiO-66 remain intact upon structural collapse, the ZrO backbone of the MIL-140 frameworks undergoes substantial distortion. Density functional theory calculations have been performed to investigate defective models of MIL-140B and show, through comparison of calculated and experimental 13C NMR spectra, that amorphization and defects in the materials are linked.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bennett
authors.forename: Tanya K
authors.initials: TK
authors.lastname: Todorova
authors.forename: Emma F
authors.initials: EF
authors.lastname: Baxter
authors.forename: David G
authors.initials: DG
authors.lastname: Reid
authors.forename: Christel
authors.initials: C
authors.lastname: Gervais
authors.forename: Bart
authors.initials: B
authors.lastname: Bueken
authors.forename: B
authors.initials: B
authors.lastname: Van de Voorde
authors.forename: Dirk
authors.initials: D
authors.lastname: De Vos
authors.forename: David A
authors.initials: DA
authors.lastname: Keen
authors.forename: Caroline
authors.initials: C
authors.lastname: Mellot-Draznieks