2-Hexyne

2-Hexyne is an organic compound that belongs to the alkyne group. Just like its isomers, it also has the chemical formula of C₆H₁₀.

2-Hexyne

Names
Preferred IUPAC name Hex-2-yne
Identifiers
CAS Number	764-35-2
3D model (JSmol)	Interactive image
ChemSpider	31016
ECHA InfoCard	100.011.015
EC Number	212-117-6
PubChem CID	33629
UNII	EC0WA2IXU7
CompTox Dashboard (EPA)	DTXSID9074725
InChI InChI=1S/C6H10/c1-3-5-6-4-2/h3,5H2,1-2H3 Key: MELUCTCJOARQQG-UHFFFAOYSA-N
SMILES CCCC#CC
Properties
Chemical formula	C6H10
Molar mass	82.146 g·mol−1
Density	0.7317
Melting point	−88 °C (−126 °F; 185 K)[1]
Boiling point	83.8 °C (182.8 °F; 356.9 K)[2]
Refractive index (nD)	1.4135
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H304, H315, H319
Precautionary statements	P210, P233, P240, P241, P242, P243, P264, P280, P301+P310, P302+P352, P303+P361+P353, P305+P351+P338, P321, P331, P332+P313, P337+P313, P362, P370+P378, P403+P235, P405, P501
Related compounds
Related compounds	3-Hexyne, 1-Hexyne
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Reactions

2-Hexyne can be semihydrogenated to yield 2-hexene or fully hydrogenated to hexane.^[3] With appropriate noble metal catalysts it can selectively form cis-2-hexene.^[4]

2-Hexyne can act as a ligand on gold atoms.^[5]

With strong sulfuric acid, the ketone 2-hexanone is produced. However this reaction also causes polymerization and charring.^[6]

Under heat and pressure 2-hexyne polymerizes to linear oligomers and polymers. This can be hastened by some catalysts such as molybdenum pentachloride with tetraphenyl tin. However Ziegler–Natta catalysts have no action as the triple bond is hindered.^[7]