Selenium trioxide

Selenium trioxide[1]
Structural formula of the monomer as found in the gas phase
Structural formula of the monomer as found in the gas phase
Space-filling model of the monomer as found in the gas phase
Space-filling model of the monomer as found in the gas phase
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.972 Edit this at Wikidata
  • InChI=1S/O3Se/c1-4(2)3 checkY
    Key: VFLXBUJKRRJAKY-UHFFFAOYSA-N checkY
  • InChI=1/O3Se/c1-4(2)3
    Key: VFLXBUJKRRJAKY-UHFFFAOYAC
  • monomer: O=[Se](=O)=O
  • cyclic tetramer: O=[Se]0(=O)O[Se](=O)(=O)O[Se](=O)(=O)O[Se](=O)(=O)O0
Properties
SeO3
Molar mass 126.96 g/mol
Appearance white hygroscopic crystals
Density 3.44 g/cm3
Melting point 118.35 °C (245.03 °F; 391.50 K)
Boiling point sublimes
very soluble
Structure
tetragonal
Hazards
GHS labelling:[3]
GHS06: ToxicGHS09: Environmental hazard
Danger
H301, H331, H373, H410
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 0: Will not burn. E.g. waterInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard OX: Oxidizer. E.g. potassium perchlorate
4
0
2
OX
Lethal dose or concentration (LD, LC):
7 mg/kg (rat, oral)
7.08 mg/kg (mouse, oral)
5.06 mg/kg (guinea pig, oral)
2.25 mg/kg (rabbit, oral)
13 mg/kg (horse, oral)[2]
13 mg/kg (pig, oral)
9.9 mg/kg (cow, oral)
3.3 mg/kg (goat, oral)
3.3 mg/kg (sheep, oral)[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Selenium trioxide is the inorganic compound with the formula SeO3. It is white, hygroscopic solid. It is also an oxidizing agent and a Lewis acid. It is of academic interest as a precursor to Se(VI) compounds.[4]

  1. ^ Lide, David R. (1998). Handbook of Chemistry and Physics (87 ed.). Boca Raton, Florida: CRC Press. pp. 4–81. ISBN 0-8493-0594-2.
  2. ^ a b "Selenium compounds (as Se)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. ^ "C&L Inventory". echa.europa.eu. Retrieved 16 December 2021.
  4. ^ Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier ISBN 0123526515