Amorphous uranium(VI) oxide

Amorphous uranium(VI) oxide[1]
Names
IUPAC name
Diuranyl heptoxide
Other names
Amorphous UO3
Properties
Am-U2O7
Molar mass 588 g/mol
Appearance Orange-brown powder
Density 6.8 g/cm3
Partially soluble
Related compounds
Related uranium oxides
 Uranyl peroxide
Triuranium octoxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Amorphous uranium(VI) oxide (am-U2O7) is an orange diuranyl compound, most commonly obtained from the thermal decomposition of uranyl peroxide tetrahydrate at temperatures between 150 and 500 °C (300 and 930 °F). It exists at room temperature as a powder. Am-U2O7 does not comprise a regular, long-range atomic structure, as demonstrated by its characteristic diffuse scattering pattern obtained by X-ray diffraction. As a result, the molecular structure of this material is little understood, although experimental and computational attempts to elucidate a local atomic environment have yielded some success.[2][3]

  1. ^ L. Sweet, C. Henager, S. Hu, T. Johnson, D. Meier, S. Peper and J. Schwantes, PNNL-20951: Investigation of Uranium Polymorphs, PNNL for U.S Department of Energy, 2011. doi:10.13140/RG.2.1.3073.0004
  2. ^ S. Odoh, J. Shamblin, C. Colla, S. Hickam, H. Lobeck, R. Lopez, T. Olds, J. Szymanowski, G. Sigmon, J. Neuefeind, W. Casey, M. Lang, L. Gagliardi and P. Burns, Structure and Reactivity of X-ray Amorphous Uranyl Peroxide, U2O7, J. Inorg. Chem., 2016, 55, pp.3541-3546. doi:10.1021/acs.inorgchem.6b00017
  3. ^ A. Shields, A. Miskowiec, J. Niedziela, M. Kirkegaard, K. Maheshwari, M. Ambrogio, R. Kapsimalis and B. Anderson, Shining a light on amorphous U2O7: A computational approach to understanding amorphous uranium materials, Opt. Mater., 2019, 89, 295-298. doi:10.1016/j.optmat.2019.01.040