Tetrachloroethylene oxide, perchloroethylene oxide (PCEO) or tetrachlorooxirane, is the perchlorinated analogue of ethylene oxide and a proposed metabolite of tetrachloroethylene.[3] It is a halogenated epoxide with the formula C2Cl4O. Tetrachloroethylene oxide is fairly stable but rearranges to trichloroacetyl chloride at higher temperatures.[4]
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| Names | |
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| IUPAC name
tetrachlorooxirane
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| Other names
Perchloroethylene oxide (PCEO), Epoxyperchlorovinyl, Tetrachloroepoxyethane
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C2Cl4O | |
| Molar mass | 181.82 g·mol−1 |
| Appearance | liquid |
| Density | 1.72 g/cm3[1] |
| Melting point | –58 °C[2] |
| Boiling point | 110 °C [1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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It is metabolised to trichloroacetyl chloride which is hydrolysed to trichloroacetic acid.[5]
Production
editTetrachloroethylene oxide was first synthesised by the English chemist Frederick William Kirkbride in 1940, by exposing a mixture of oxygen and chlorine in tetrachloroethylene to UV light.[6]
Tetrachloroethylene oxide can be obtained by the direct oxidation of tetrachloroethylene under UV light.[4]
Reactions
editUnlike most epoxides, PCEO does not polymerise.[4]
PCEO reacts with methanol, with mercury(II) chloride as the catalyst, giving methyl trichloroacetate and hydrogen chloride:[2]
- C2Cl4O + CH3OH → CH3O(CO)CCl3 + HCl
PCEO reacts with methanolic potassium hydroxide to give potassium oxalate.[2] It is slowly decomposed by dilute acid or base solutions, giving off carbon monoxide, carbon dioxide and hydrogen chloride which was possibly from the further decomposition of the intermediate oxalyl chloride.[2]
See also
editReferences
edit- ^ a b Yaws, C. L. (2015). The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals: Physical Properties for More Than 54,000 Organic and Inorganic Chemical Compounds, Coverage for C1 to C100 Organics and Ac to Zr Inorganics.
- ^ a b c d Frankel, Donald; Johnson, Claude; Pitt, Harold (1957). "Notes - Preparation and Properties of Tetrachloroethylene Oxide". The Journal of Organic Chemistry. 22 (9). American Chemical Society (ACS): 1119–1120. doi:10.1021/jo01360a614. ISSN 0022-3263.
- ^ Raat, W. K. d. (2003). 133 Tetrachloroethylene (PER). Sweden: Arbetslivsinstitutet.
- ^ a b c Campbell, R. W.; Vogl, O. (1977). "A Practical Synthesis of Tetrachloroethylene Oxide". Journal of Macromolecular Science: Part A - Chemistry. 11 (3). Informa UK Limited: 515–534. doi:10.1080/00222337708061286. ISSN 0022-233X.
- ^ Testa, B., Mayer, J. M. (2003). Hydrolysis in Drug and Prodrug Metabolism. page 633
- ^ Oxidation of Perchloroethylene, Official Gazette of the United States Patent Office. (1943)