Perfluoroisobutene

Perfluoroisobutene
Names
	Preferred IUPAC name 1,1,3,3,3-Pentafluoro-2-(trifluoromethyl)prop-1-ene
	Other names Perfluoroisobutene, Perfluoroisobutylene, Octafluoroisobutylene, Octafluoro-sec-butene, PFIB
Identifiers
CAS Number	382-21-8 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL4634291;
ChemSpider	55060 ;
ECHA InfoCard	100.108.743
EC Number	609-533-9;
PubChem CID	61109;
RTECS number	UD1800000;
UNII	1J9BGS6NTY ;
CompTox Dashboard (EPA)	DTXSID4073176 ;
	InChI InChI=1S/C4F8/c5-2(6)1(3(7,8)9)4(10,11)12 Key: DAFIBNSJXIGBQB-UHFFFAOYSA-N ; InChI=1/C4F8/c5-2(6)1(3(7,8)9)4(10,11)12 Key: DAFIBNSJXIGBQB-UHFFFAOYAF;
	SMILES FC(F)=C(C(F)(F)F)C(F)(F)F;
Properties
Chemical formula	C4F8
Molar mass	200.030 g/mol
Appearance	colorless gas
Density	8.2 g/l
Melting point	−130 °C (−202 °F; 143 K)
Boiling point	7.0 °C (44.6 °F; 280.1 K)
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H330, H370
Precautionary statements	P260, P264, P270, P271, P284, P304+P340, P307+P311, P310, P320, P321, P403+P233, P405, P501
	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

Perfluoroisobutene (PFIB) is the perfluorocarbon with the formula (CF₃)₂C=CF₂. Classified as a perfluoroalkene, it is the fluorinated counterpart of the hydrocarbon isobutene. This colorless gas is notable for its high toxicity.

Production and reactions

PFIB is one product of pyrolysis of polytetrafluoroethylene (PTFE). Tetrafluoroethylene thermally dimerizes to octafluorocyclobutane, which above 600 °C degrades to hexafluoropropylene and PFIB.

Perfluoroisobutene is highly reactive toward nucleophiles, e.g. methanol. It also forms addition compounds with thiols, and it is this reactivity that may be related to its toxicity. It hydrolyzes readily to give the relatively innocuous (CF₃)₂CHCO₂H, which readily decarboxylates to give hexafluoropropane.^{[citation needed]}

Oxidation of HFIB with potassium permanganate gives hexafluoroacetone.

Safety

Perfluoroisobutene is highly toxic with an LCt = 880 mg⋅min⋅m⁻³ (mice). It is a Schedule 2 substance of the Chemical Weapons Convention. Its toxicity is comparable to that of phosgene.

References

1 2 3 4 Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2000). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a11_349. ISBN 978-3-527-30385-4.
↑ Stewart, Charles E. (2006). Weapons of mass casualties and terrorism response handbook. American Academy of Orthopaedic Surgeons. Sudbury, Mass: Jones and Bartlett. ISBN 978-0-7637-2425-2.
1 2 Timperley, Christopher M. (2000). "Highly-toxic fluorine compounds". Fluorine Chemistry at the Millennium. pp. 499–538. doi:10.1016/B978-008043405-6/50040-2. ISBN 9780080434056.
↑ Michael Van Der Puy, Louis G. Anello (1985). "Hexafluoroacetone". Organic Syntheses. 63: 154. doi:10.15227/orgsyn.063.0154.

External links

International Chemical Safety Card 1216

[Ullmann-1] 1 2 3 4 Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2000). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a11_349. ISBN 978-3-527-30385-4.

[2] Stewart, Charles E. (2006). Weapons of mass casualties and terrorism response handbook. American Academy of Orthopaedic Surgeons. Sudbury, Mass: Jones and Bartlett. ISBN 978-0-7637-2425-2.

[Timp-3] 1 2 Timperley, Christopher M. (2000). "Highly-toxic fluorine compounds". Fluorine Chemistry at the Millennium. pp. 499–538. doi:10.1016/B978-008043405-6/50040-2. ISBN 9780080434056.

[4] Michael Van Der Puy, Louis G. Anello (1985). "Hexafluoroacetone". Organic Syntheses. 63: 154. doi:10.15227/orgsyn.063.0154.