Structural Phase Transitions and Water Dynamics in Uranyl Fluoride Hydrates

Autor:	Lee Trowbridge, Eugene Mamontov, Andrew Miskowiec, Brian B. Anderson, Kenneth W. Herwig, Marie C. Kirkegaard, Ashfia Huq, Adam J. Rondinone
Rok vydání:	2015
Předmět:	chemistry.chemical_compound Crystallography chemistry Ligand Coordination number Phase (matter) Quasielastic neutron scattering Anhydrous Organic chemistry Physical and Theoretical Chemistry Uranyl fluoride Radiation chemistry Uranyl
Zdroj:	The Journal of Physical Chemistry A. 119:11900-11910
ISSN:	1520-5215 1089-5639
Popis:	We report a novel production method for uranium oxyfluoride [(UO2)7F14(H2O)7]·4H2O, referred to as structure D. Structure D is produced as a product of hydrating anhydrous uranyl fluoride, UO2F2, through the gas phase at ambient temperatures followed by desiccation by equilibration with a dry environment. We follow the structure of [(UO2)7F14(H2O)7]·4H2O through an intermediate, liquid-like phase, wherein the coordination number of the uranyl ion is reduced to 5 (from 6 in the anhydrous structure), and a water molecule binds as an equatorial ligand to the uranyl ion. Quasielastic neutron scattering results compare well with previous measurements of mineral hydrates. The two groups of structurally distinct water molecules in D perform restricted motion on a length scale commensurate with the O-H bond (r = 0.92 Å). The more tightly bound equatorial ligand waters rotate slower (Dr = 2.2 ps(-1)) than their hydrogen-bonded partners (Dr = 28.7 ps(-1)).
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::45780a56ffb15972f8e24581027bea49 https://doi.org/10.1021/acs.jpca.5b09296 Zobrazit plný text záznamu