Hexafluoro-2-butyne

Hexafluoro-2-butyne
Names
	Preferred IUPAC name 1,1,1,4,4,4-Hexafluorobut-2-yne
	Other names HFB
Identifiers
CAS Number	692-50-2 ;
3D model (JSmol)	Interactive image;
ChemSpider	62855 ;
ECHA InfoCard	100.010.667
EC Number	211-732-7;
PubChem CID	69654;
RTECS number	ES0702500;
CompTox Dashboard (EPA)	DTXSID3061003 ;
	InChI InChI=1S/C4F6/c5-3(6,7)1-2-4(8,9)10 Key: WBCLXFIDEDJGCC-UHFFFAOYSA-N ; InChI=1/C4F6/c5-3(6,7)1-2-4(8,9)10 Key: WBCLXFIDEDJGCC-UHFFFAOYAY;
	SMILES FC(F)(F)C#CC(F)(F)F;
Properties
Chemical formula	C4F6
Molar mass	162.034 g·mol−1
Appearance	Colorless gas
Density	1.602 g/cm3
Melting point	−117 °C (−179 °F; 156 K)
Boiling point	−25 °C (−13 °F; 248 K)
Solubility in water	Insoluble
Structure
Dipole moment	0 D
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Toxic gas
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H280, H331
Precautionary statements	P261, P311, P410+P403
Related compounds
Related compounds	Dimethyl acetylenedicarboxylate; Hexachlorobutadiene; Acetylene
	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

Hexafluoro-2-butyne (HFB) is a fluorocarbon with the chemical structure CF₃C≡CCF₃. HFB is a particularly electrophilic acetylene derivative, and hence a potent dienophile for Diels–Alder reactions.^[2]^[3]

Synthesis and reactions[edit]

HFB is prepared by the action of sulfur tetrafluoride on acetylenedicarboxylic acid or by the reaction of potassium fluoride (KF) with hexachlorobutadiene.

It reacts with sulfur to give 3,4-bis(trifluoromethyl)-1,2-dithiete.

Cycloaddition of HFB and dithionitronium (NS₂⁺) gives the 1,2,5-dithiazolium cation. This derivative can be reduced to the 7 electron neutral radical. This particular 1,3,5-dithiazole is also rare example of a radical that can be obtained as solid, liquid, and gaseous states. As a gas, it is blue.^[4]

References[edit]

^ "Hexafluoro-2-butyne 99%". Sigma-Aldrich.
^ Essers, Michael; Haufe, Günter (2006). "Hexafluoro-2-butyne". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn00669. ISBN 0471936235.
^ E S Turbanova, A A Petrov (1991). "Perfluoroalkyl(aryl)acetylenes". Russian Chemical Reviews. 60 (5): 501–523. Bibcode:1991RuCRv..60..501T. doi:10.1070/RC1991v060n05ABEH001092.
^ Brownridge, Scott; Du, Hongbin; Fairhurst, Shirley A.; Haddon, Robert C.; Oberhammer, Heinz; Parsons, Simon; Passmore, Jack; Schriver, Melbourne J.; Sutcliffe, Leslie H.; Westwood, Nicholas P. C. (2000). "The Isolation, Characterisation, Gas Phase Electron Diffraction and Crystal Structure of the Thermally Stable Radical CF₃CSNSCCF₃". Journal of the Chemical Society, Dalton Transactions (19): 3365–3382. doi:10.1039/B001489N.

[1] "Hexafluoro-2-butyne 99%". Sigma-Aldrich.

[2] Essers, Michael; Haufe, Günter (2006). "Hexafluoro-2-butyne". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn00669. ISBN 0471936235.

[3] E S Turbanova, A A Petrov (1991). "Perfluoroalkyl(aryl)acetylenes". Russian Chemical Reviews. 60 (5): 501–523. Bibcode:1991RuCRv..60..501T. doi:10.1070/RC1991v060n05ABEH001092.

[4] Brownridge, Scott; Du, Hongbin; Fairhurst, Shirley A.; Haddon, Robert C.; Oberhammer, Heinz; Parsons, Simon; Passmore, Jack; Schriver, Melbourne J.; Sutcliffe, Leslie H.; Westwood, Nicholas P. C. (2000). "The Isolation, Characterisation, Gas Phase Electron Diffraction and Crystal Structure of the Thermally Stable Radical CF₃CSNSCCF₃". Journal of the Chemical Society, Dalton Transactions (19): 3365–3382. doi:10.1039/B001489N.

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