Plutonium(IV) sulfate
| Names | |
|---|---|
| IUPAC name
Plutonium(IV) sulfate
| |
| Identifiers | |
3D model (JSmol)
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|
| |
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| Properties | |
| Pu(SO4)2 | |
| Molar mass | 506.18 g/mol |
| Appearance | Red crystalline solid[1] |
| Melting point | ~800°C? (Decomposes)[2] |
| Somewhat soluble[3] | |
| Structure | |
| Orthorhombic | |
| Fddd (α-Pu(SO4)2·4H2O)[1][4] Pnma (β-Pu(SO4)2·4H2O)[4] | |
| mmm (α-Pu(SO4)2·4H2O)[1] | |
| Related compounds | |
Other anions
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Plutonium(IV) oxide Plutonium(IV) fluoride |
Other cations
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Uranium(IV) sulfate Uranyl sulfate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Plutonium(IV) sulfate is a chemical compound consisting of plutonium and sulfate ions, with the chemical formula Pu(SO4)2·xH2O. It has been observed as a tetrahydrate, where x=4,[1][3] as well as an anhydrous form, where x=0.[2] The tetrahydrate has been used as a primary analytical standard for plutonium.[5]
Formation & Reactions
[edit]Plutonium(IV) sulfate is produced when plutonium(IV) ions react with bisulfate or sulfate ions in aqueous solution:[6]
- Pu4+(aq) + 2 HSO−4(aq) → Pu(SO4)2(aq) + 2 H+(aq)
- Pu4+(aq) + 2 SO2−4(aq) → Pu(SO4)2(aq)
At high temperatures (~800°C), plutonium(IV) sulfate tetrahydrate decomposes. It first releases its water to form anhydrous plutonium(IV) sulfate, then releases sulfur oxides to form plutonium(IV) oxide.[3][2]
At normal temperatures, however, plutonium(IV) sulfate tetrahydrate is stable in air, even at high humidity.[5][7]
Structure
[edit]Plutonium(IV) sulfate tetrahydrate ligands are monodentate, with bonds between plutonium atoms and oxygen atoms in the water and sulfate molecules. Each plutonium atom has a coordination number of 8, and a coordination geometry of square antiprismatic. Plutonium(IV) sulfate tetrahydrate crystals have an orthorhombic crystal structure. Hydrogen bonds exist between hydrogen atoms in the water molecules and oxygen atoms in the sulfate ions that are not attached to the plutonium atom.[1][4]
Allotropes
[edit]Plutonium(IV) sulfate tetrahydrate has two allotropes– α-Pu(SO4)2·4H2O and β-Pu(SO4)2·4H2O. The two forms share the same molecular geometry, but differ in the functional nature of the hydrogen bonds. The α-form transitions into the β-form at ~120°C.[4]
α-Pu(SO4)2·4H2O has a unit cell with dimensions a=26.53Å, b=12.00Å, and c=5.69Å, where there are 8 formula units per unit cell.[4]
β-Pu(SO4)2·4H2O has a unit cell with dimensions a=14.54Å, b=10.98Å, and c=5.67Å, where there are 4 formula units per unit cell.[4]
Hazards
[edit]Plutonium(IV) sulfate is a highly dangerous compound, due to it being radioactive and carcinogenic.[3]
References
[edit]- ^ a b c d e Richard E. Wilson (18 May 2011). "Structural Periodicity in Plutonium(IV) Sulfates". Inorganic Chemistry. 50 (12): 5663–5670. doi:10.1021/ic200384h. PMID 21591736.
- ^ a b c Waterbury, Glenn R., Douglass, Robert M., Metz, Charles F. (1 July 1961). ""Thermogravimetric Behavior of Plutonium Metal, Nitrate, Sulfate, and Oxalate"". Analytical Chemistry. 33 (8): 1018–1023. doi:10.1021/ac60176a047.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b c d NBL Program Office, "Safety Data Sheet: Plutonium Sulfate Tetrahydrate", https://www.energy.gov/sites/prod/files/2020/11/f80/SDS-Plutonium_Sulfate_2020.pdf
- ^ a b c d e f Jayadevan, N.C., Mudher, K.D.S., Chackraburtty, D.M. (25 Aug 2010). "The crystal structures of α- and β-forms of plutonium(IV) sulphate tetrahydrate". Zeitschrift für Kristallographie - Crystalline Materials. 161 (1–4): 7–14. doi:10.1524/zkri.1982.161.14.7.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b C. E. Pietri, A. W. Wenzel (1 Nov 1962). "The stability of plutonium sulphate tetrahydrate, an analytical standard: a ten-year evaluation". Talanta. 18 (8): 849–852. doi:10.1016/0039-9140(71)80138-8. PMID 18960954.
- ^ Lemire, R. J. et al., Chemical Thermodynamics of Neptunium and Plutonium, Elsevier, Amsterdam, 2001.
- ^ C. E. Pietri (1 Nov 1962). "Plutonium Sulfate Tetrahydrate, a Proposed Primary Analytical Standard for Plutonium". Analytical Chemistry. 163 (12): 130–136. doi:10.1021/ac60192a027.