Selenium oxydichloride
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Names | |||
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IUPAC name Selenium oxychloride | |||
Other names Seleninyl chloride | |||
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3D model (JSmol) |
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ChemSpider |
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ECHA InfoCard | 100.029.313 ![]() | ||
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InChI
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Properties | |||
Chemical formula | SeOCl2 | ||
Molar mass | 165.87 g/mol | ||
Appearance | colorless 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) | ||
Refractive index (nD) | 1.651 (20 °C) | ||
Structure | |||
Molecular shape | trigonal pyramidal | ||
Hazards | |||
GHS labelling:[2] | |||
Pictograms | ![]() ![]() ![]() ![]() | ||
Warning | |||
Hazard statements | 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) | ![]() 3 0 1 | ||
Lethal dose or concentration (LD, LC): | |||
LDLo (lowest published) | 2 mg/kg (rabbit, dermal)[1] | ||
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). ![]() ![]() ![]() Infobox references |
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.
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
- Selenium oxybromide SeOBr2
- Selenous acid H2SeO3
References
- ^ "Selenium compounds (as Se)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ "Selenium oxychloride". pubchem.ncbi.nlm.nih.gov. Retrieved 12 December 2021.
- ^ Smith, G. B. L.; Jackson, Julius (1950). "Selenium(IV) Oxychloride". Inorganic Syntheses. Vol. 3. pp. 130–137. doi:10.1002/9780470132340.ch34. ISBN 9780470132340.
- ^ Audrieth & Kleinberg 1953, p. 237.
- ^ Audrieth & Kleinberg 1953, pp. 239–242.
- ^ Audrieth, Ludwig F.; Kleinberg, Jacob (1953). Non-aqueous solvents. New York: John Wiley & Sons. pp. 235–6. LCCN 52-12057.
- v
- t
- e
- Se3S5
- Se2S6
- Se2Cl2
- C3H7NO2Se
- SeBr2
- SeCl2
- SeS2
- SeO2−3
- SeBr4
- SeCl4
- SeF4
- SeO2
- SeS2
- SeOF2
- SeOCl2
- SeOBr2
- H2SeO3
- SeO2−4
- SeF6
- SeO3
- SeO2F2
- H2SeO4
- SeO2−4 + SeO2−3