title: Probing the oxygen environment in UO(2)(2+) by solid-state 17O nuclear magnetic resonance spectroscopy and relativistic density functional calculations.
abstract: A combined theoretical and solid-state (17)O nuclear magnetic resonance (NMR) study of the electronic structure of the uranyl ion UO(2)(2+) in (NH(4))(4)UO(2)(CO(3))(3) and rutherfordine (UO(2)CO(3)) is presented, the former representing a system with a hydrogen-bonding environment around the uranyl oxygens and the latter exemplifying a uranyl environment without hydrogens. Relativistic density functional calculations reveal unique features of the U-O covalent bond, including the finding of (17)O chemical shift anisotropies that are among the largest for oxygen ever reported (>1200 ppm). Computational results for the oxygen electric field gradient tensor are found to be consistently larger in magnitude than experimental solid-state (17)O NMR measurements in a 7.05 T magnetic field indicate. A modified version of the Solomon theory of the two-spin echo amplitude for a spin-5/2 nucleus is developed and applied to the analysis of the (17)O echo signal of U (17)O(2)(2+).
authors.affiliation: Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, P. O. Box 999, Richland, Washington 99352, USA. hm.cho@pnl.gov
authors.forename: Herman
authors.initials: H
authors.lastname: Cho
authors.forename: Wibe A
authors.initials: WA
authors.lastname: de Jong
authors.forename: Chuck Z
authors.initials: CZ
authors.lastname: Soderquist