Selenium oxydichloride

Last updated
Selenium oxydichloride
Seleninyl chloride.png
Structure of the selenium oxydichloride molecule SeOCl2pyramidal.png
Structure of the selenium oxydichloride molecule
3D model of the selenium oxydichloride molecule Selenium-oxydichloride-3D-vdW.png
3D model of the selenium oxydichloride molecule
Names
IUPAC name
Selenium oxychloride
Other names
Seleninyl chloride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.313 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 232-244-0
PubChem CID
RTECS number
  • VS7000000
UNII
  • InChI=1S/Cl2OSe/c1-4(2)3 X mark.svgN
    Key: LIRMPIXWGWLNND-UHFFFAOYSA-N X mark.svgN
  • InChI=1/Cl2OSe/c1-4(2)3
    Key: LIRMPIXWGWLNND-UHFFFAOYAX
  • O=[Se](Cl)Cl
Properties
SeOCl2
Molar mass 165.87 g/mol
Appearancecolorless liquid
Density 2.43 g/cm3, liquid
Melting point 10.9 °C (51.6 °F; 284.0 K)
Boiling point 177.2 °C (351.0 °F; 450.3 K)
1.651 (20 °C)
Structure
trigonal pyramidal
Hazards
GHS labelling: [1]
GHS-pictogram-acid.svg GHS-pictogram-skull.svg GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Warning
H301, H314, H331, H373, H410
P260, P261, P264, P270, P271, P273, P280, P301+P310, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P314, P321, P330, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
3
0
1
Lethal dose or concentration (LD, LC):
2 mg/kg (rabbit, dermal) [2]
Related compounds
Related compounds
SOCl2, POCl3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Selenium oxydichloride is the inorganic compound with the formula SeOCl2. It is a colorless liquid. With a high dielectric constant (55) and high specific conductance, it is an attractive solvent. Structurally, it is a close chemical relative of thionyl chloride SOCl2, being a pyramidal molecule.

Contents

Preparation and reactions

Selenium oxydichloride can be prepared by several methods, and a common one involves the conversion of selenium dioxide to dichloroselenious acid followed by dehydration: [3]

SeO2 + 2 HCl → Se(OH)2Cl2
Se(OH)2Cl2 → SeOCl2 + H2O

The original synthesis involved the redistribution reaction of selenium dioxide and selenium tetrachloride.

Pure selenium oxydichloride autoionizes to a dimer: [4]

SeOCl2 ↔ (SeO)2Cl+
3
 + Cl

The SeOCl2 is generally a labile Lewis acid and solutions of sulfur trioxide in SeOCl2 likely form [SeOCl]+[SO3Cl] the same way. [5]

The compound hydrolyzes readily to form hydrogen chloride and selenium dioxide,[ citation needed ] and very few organic compounds dissolve in it without reaction. At elevated temperatures, it is a strong oxidizer, yielding a chloride, selenium dioxide, and diselenium dichloride. [6]

See also

References

  1. "Selenium oxychloride". pubchem.ncbi.nlm.nih.gov. Retrieved 12 December 2021.
  2. "Selenium compounds (as Se)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. Smith, G. B. L.; Jackson, Julius (1950). "Selenium(IV) Oxychloride". Inorganic Syntheses. Vol. 3. pp. 130–137. doi:10.1002/9780470132340.ch34. ISBN   9780470132340.{{cite book}}: ISBN / Date incompatibility (help)
  4. Audrieth & Kleinberg 1953, p. 237.
  5. Audrieth & Kleinberg 1953, pp. 239–242.
  6. Audrieth, Ludwig F.; Kleinberg, Jacob (1953). Non-aqueous solvents. New York: John Wiley & Sons. pp. 235–6. LCCN   52-12057.