Perfluoroisobutene

Perfluoroisobutene
Names
	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;
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 C(=C(F)F)(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
Boiling point	7.0 °C (44.6 °F; 280.1 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Perfluoroisobutene (PFIB) is the perfluorocarbon counterpart of the hydrocarbon isobutene and has the formula (CF₃)₂C=CF₂. An alkene, it is a colorless gas that it is notable as a highly toxic perfluoroalkene. Few simple alkenes are as toxic.

Safety

Perfluoroisobutene is quite toxic with an LCt = 880 mg⋅min⋅m⁻³ (mice).^[1] It is a Schedule 2 substance of the Chemical Weapons Convention.

Perfluoroisobutene is highly reactive toward nucleophiles. It hydrolyzes readily to give the relatively innocuous (CF₃)₂CHCO₂H, which readily decarboxylates to give hexafluoropropane. It forms addition compounds with thiols, and it is this reactivity that may be related to its toxicity.^[1]

PFIB is a product of pyrolysis of polytetrafluoroethylene (PTFE), one of the substances invoked to explain polymer fume fever.

External links

International Chemical Safety Card 1216

References

^ ^a ^b 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.

[Timp-1] 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.

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