title: Structural Transitions of the Metal-Oxide Nodes within Metal-Organic Frameworks: On the Local Structures of NU-1000 and UiO-66.
abstract: In situ pair distribution function (PDF) analyses and density functional theory (DFT) computations are used to probe local structural transitions of M6O8 nodes found in two metal organic frameworks (MOFs), NU-1000 and UiO-66, for M = Zr, Hf. Such transitions are found to occur without change to the global framework symmetry at temperatures within a range relevant to many potential MOF applications. For the particular M6(O)8 nodes studied here, the observed distortions can be mapped to polymorphic forms known for bulk ZrO2. In the MOF framework, however, node distortions are found to occur at substantially lower temperature than analogous distortions in bulk ZrO2 owing to the nanoscale nature of the former.
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
authors.forename: Ana E
authors.initials: AE
authors.lastname: Platero-Prats
authors.affiliation: Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States.
authors.forename: Andreas
authors.initials: A
authors.lastname: Mavrandonakis
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
authors.forename: Leighanne C
authors.initials: LC
authors.lastname: Gallington
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Hupp
authors.affiliation: Department of Chemistry, Northwestern University , Evanston, Illinois 60208-3113, United States.|Department of Chemistry, Faculty of Science, King Abdulaziz University , Jeddah 21589, Saudi Arabia.
authors.forename: Omar K
authors.initials: OK
authors.lastname: Farha
authors.affiliation: Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Cramer
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439-4858, United States.
authors.forename: Karena W
authors.initials: KW
authors.lastname: Chapman