Plutonium oxysulfides
 | This article may be too technical for most readers to understand. (September 2025) |
Plutonium oxysulfides are compounds of plutonium, oxygen and sulfur, where sulfur exists as sulfide or polysulfide ions and plutonium exists in the trivalent state or tetravalent state. They are mixed oxide-sulfides and include Pu2O2S, Pu4O4S3, PuOS, and Pu2O2S3.[1]
Compounds
[edit]Pu2O2S
[edit]Diplutonium dioxide monosulfide (Pu2O2S) is formed by reacting plutonium(III) oxide and plutonium sesquisulfide at 1400 °C:[1]
- 2 Pu2O3 + Pu2S3 → 3 Pu2O2S
Or the decomposition of Pu4O4S3 at 1100 °C.[1]
It is isostructural with (has the same structure as) cerium(III) oxysulfide, having a hexagonal structure with lattice parameters a=3.929 and c=6.768 Å.[1]
Pu4O4S3
[edit]Tetraplutonium tetroxide trisulfide (Pu4O4S3) is formed by the decomposition of PuOS at 600 °C. It is a mixed valence compound, containing a 1:1 ratio of plutonium in its +3 and +4 oxidation states. It has a complex pseudo-hexagonal structure, with lattice parameters a=4.06, b=6.72, c=3.87 Å, and β=118°.[1]
PuOS
[edit]Plutonium monoxide monosulfide (PuOS) is formed by reacting sulfur with Pu2O2S at 500 °C (though this process also creates Pu2O2S3), or by reacting plutonium monosulfide with oxygen:[1]
- PuS + ½ O2 → PuOS
It is unstable, dissociating to Pu4O4S3 at 600 °C. It adopts the same structure as uranium oxysulfide, UOS, with which it forms a solid solution. Its structure is tetragonal, with lattice parameters a=3.80 and c=6.59 Å. It contains plutonium in its +4 oxidation state.[1]
Pu2O2S3
[edit]Diplutonium dioxide trisulfide (Pu2O2S3) is the other product formed by reacting Pu2O2S with sulfur. It is a polysulfide (compound containing sulfur-sulfur bonds) with plutonium in its +4 oxidation state, and its formula can be written as (Pu4+)2(O2−)2S2−(S2−2). It has a tetragonal structure with lattice parameters a=3.95 and c=7.95 Å.[1]