Uranyl oxalate

Uranyl oxalate (UO2C2O4) is a pale yellow powdered uranyl compound. It is often encountered in industrial nuclear processes at both the front and back-end of the nuclear fuel cycle. Due to its hygroscopicity, uranyl oxalate rarely exists in the dehydrated state and is usually instead found in the trihydrate form (UO2C2O4·3H2O) at room temperature.[1] At room temperature, the powder exhibits a monoclinic crystal structure in the P21/c space group.[2]

Uranyl oxalate
U Oxalate Trihydrate.tif
Other names
Uranyl oxalate trihydrate; uranyl oxalate hydrate
  • 2031-89-2
3D model (JSmol)
  • InChI=1S/C2H2O4.2O.U/c3-1(4)2(5)6;;;/h(H,3,4)(H,5,6);;;/q;;;+2/p-2
  • C(=O)(C(=O)[O-])[O-].O=[U+2]=O
Molar mass 358 g/mole (412 g/mol as trihydrate)
Appearance Pale yellow powder
Partially soluble
Related compounds
Related uranium oxides
Uranyl peroxide
Triuranium octoxide
Uranium dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references


Uranyl oxalate trihydrate can be produced by the reaction of uranyl nitrate hexahydrate with oxalic acid.[3]

Uranyl oxalate has been used in actinometers.[4]


  1. ^ Thompson, Nathan B. A.; Stennett, Martin C.; Gilbert, Matthew R.; Hyatt, Neil C. (2021-01-06). "Nuclear forensic signatures and structural analysis of uranyl oxalate, its products of thermal decomposition and Fe impurity dopant". Journal of Radioanalytical and Nuclear Chemistry. doi:10.1007/s10967-020-07538-2. ISSN 0236-5731.
  2. ^ Jayadevan, N. C.; Chackraburtty, D. M. (1972-11-15). "The crystal and molecular structure of uranyl oxalate trihydrate". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry. 28 (11): 3178–3182. doi:10.1107/s0567740872007691. ISSN 0567-7408.
  3. ^ Tel, H; Bülbül, M; Eral, M; Altaş, Y (November 1999). "Preparation and characterization of uranyl oxalate powders". Journal of Nuclear Materials. 275 (2): 146–150. Bibcode:1999JNuM..275..146T. doi:10.1016/s0022-3115(99)00119-1. ISSN 0022-3115.
  4. ^ Bryce-Smith, D. Photochemistry. Royal Society of Chemistry. p. 279. ISBN 978-0-85186-015-2.