Hexafluoropropylene oxide

Hexafluoropropylene oxide
Names
	IUPAC name 2,2,3-Trifluoro-3-(trifluoromethyl)oxirane
	Other names trifluoro(trifluoromethyl)oxirane
Identifiers
CAS Number	428-59-1 ;
3D model (JSmol)	Interactive image; Interactive image;
Abbreviations	HFPO
ChemSpider	9499 ;
ECHA InfoCard	100.006.411
PubChem CID	9883;
UNII	JPY12AP87N ;
CompTox Dashboard (EPA)	DTXSID6029177 ;
	InChI InChI=1S/C3F6O/c4-1(2(5,6)7)3(8,9)10-1 Key: PGFXOWRDDHCDTE-UHFFFAOYSA-N ; InChI=1/C3F6O/c4-1(2(5,6)7)3(8,9)10-1 Key: PGFXOWRDDHCDTE-UHFFFAOYAQ;
	SMILES C1(C(O1)(F)F)(C(F)(F)F)F; FC(F)(F)C1(F)OC1(F)F;
Properties
Chemical formula	C3F6O
Molar mass	166.02 g/mol
Appearance	colourless gas
Density	1300kg/m3 at 25 °C
Melting point	−144 °C (−227 °F; 129 K)
Boiling point	−27.4 °C (−17.3 °F; 245.8 K)
Solubility	nonpolar solvents
Vapor pressure	660kPa at 25 °C
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Hexafluoropropylene oxide (HFPO) is an intermediate used in industrial organofluorine chemistry; specifically it is a monomer for fluoropolymers. This colourless gas is the epoxide of hexafluoropropylene, which is a fluorinated analog of propylene oxide, HFPO is produced by Chemours and 3M and as a precursor to the lubricant Krytox and related materials. It is generated by oxidation of perfluoropropylene, e.g. with oxygen as well as other oxidants.^[1]

Reactivity

Fluoride catalyzes the formation of perfluorinated polyethers such as Krytox. The initial step entails nucleophilic attack at the middle carbon to give the perfluoropropoxide anion, which in turn attacks another monomer. This process generates a polymer terminated by an acyl fluoride, which is hydrolyzed to the carboxylic acid which is decarboxylated with fluorine.^[2] The net polymerization reaction can be represented as:

n +2 CF₃CFCF₂O → CF₃CF₂CF₂O(CF(CF₃)CF₂O)_nCF₂CF₃ + CO

Upon heating above 150 °C, HFPO decomposes to trifluoroacetyl fluoride and difluorocarbene:

CF3CFCF₂O → CF₃C(O)F + CF₂

The epoxide of tetrafluoroethylene is even more unstable with respect to trifluoroacetyl fluoride.

In the presence of Lewis acids the compound rearranges to hexafluoroacetone, another important chemical intermediate. This rearrangement can be of concern during storage as the rearrangement be catalyzed by the material of the storage cylinder's walls and leads to unwanted formation of HFA during storage. As a result of this, 3M recommends using all HFPO shipped in carbon-steel containers within 90 days of shipping.^[3]

Methanolysis affords methyl trifluoropyruvate, a reagent useful in organic synthesis:^[4]

CF₃CFCF₂O + 2 MeOH → CF₃C(O)CO₂Me + MeF + 2 HF

References

^ Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine; Kirsch, Peer (2016-01-28). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Chemical Technology. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA. pp. 1–56. doi:10.1002/14356007.a11_349.pub2. ISBN 978-3-527-30673-2.
^ "HEXAFLUOROPROPYLENE OXIDE | CAMEO Chemicals | NOAA".
^ https://multimedia.3m.com/mws/mediawebserver?SSSSSuUn_zu8l00xlYtG4x2G4v70k17zHvu9lxtD7SSSSSS ^{[bare URL]}
^ Ruth Figueroa; Richard P. Hsung; Gang Li; Jin Haek Yang (2007). "Methyltrifluoropyruvate". e-EROS Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. doi:10.1002/047084289X.rn00769. ISBN 978-0-471-93623-7.

External links

[1] Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine; Kirsch, Peer (2016-01-28). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Chemical Technology. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA. pp. 1–56. doi:10.1002/14356007.a11_349.pub2. ISBN 978-3-527-30673-2.

[2] "HEXAFLUOROPROPYLENE OXIDE | CAMEO Chemicals | NOAA".

[3] ttps://multimedia.3m.com/mws/mediawebserver?SSSSSuUn_zu8l00xlYtG4x2G4v70k17zHvu9lxtD7SSSSSS ^{[bare URL]}

[4] Ruth Figueroa; Richard P. Hsung; Gang Li; Jin Haek Yang (2007). "Methyltrifluoropyruvate". e-EROS Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons. doi:10.1002/047084289X.rn00769. ISBN 978-0-471-93623-7.

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