Actinium(III) oxide

Not to be confused with Acetic anhydride.

Actinium(III) oxide is a chemical compound containing the rare radioactive element actinium. It has the molecular formula Ac₂O₃. It is similar to its corresponding lanthanum compound, lanthanum(III) oxide, and contains actinium in the oxidation state +3.^[2][3] Actinium oxide is not to be confused with Ac₂O (acetic anhydride), where Ac is an abbreviation for acetyl instead of the symbol of the element actinium.

Actinium(III) oxide

Unit cell, ball and stick model of actinium(III) oxide
Names
IUPAC name Actinium(III) oxide
Systematic IUPAC name Actinium(3+) oxide
Other names Actinium sesquioxide
Identifiers
CAS Number	12002-61-8 N
3D model (JSmol)	Interactive image
ChemSpider	10700920
ECHA InfoCard	100.031.275
EC Number	234-417-6
PubChem CID	21946271
CompTox Dashboard (EPA)	DTXSID601029728
InChI InChI=1S/2Ac.3O/q;;3*-2 Y[pubchem] Key: MAPOZTWVBAGEOP-UHFFFAOYSA-N Y[pubchem]
SMILES [O--].[O--].[O--].[Ac+3].[Ac+3]
Properties
Chemical formula	Ac2O3
Molar mass	502.053 g/mol
Appearance	white
Melting point	2,327 °C (4,221 °F; 2,600 K)[1]
Structure
Crystal structure	Trigonal, hP5
Space group	P3m1, No. 164
Lattice constant	a = 408 pm, c = 630 pm[1]
Related compounds
Other cations	Lanthanum(III) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Reactions

• Ac₂O₃ + 6HF → 2AcF₃ + 3H₂O
• Ac₂O₃ + 6HCl → 2AcCl₃ + 3H₂O
• 4Ac(NO₃)₃ → 2Ac₂O₃ + 12NO₂ + 3O₂
• 4Ac + 3O₂ → 2Ac₂O₃
• Ac₂O₃ + 2AlBr₃ → 2AcBr₃ + Al₂O₃
• 2Ac(OH)₃ → Ac₂O₃ + 3H₂O
• Ac₂(C₂O₄)₃ → Ac₂O₃ + 3CO₂ + 3CO
• Ac₂O₃ + 3H₂S → Ac₂S₃ + 3H₂O