Informatics Educational Institutions & Programs

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)
Boiling point	83.8 °C (182.8 °F; 356.9 K)
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

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

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]

References

^ Campbell, Kenneth N.; Eby, Lawrence T. (October 1941). "The Reduction of Multiple Carbon—Carbon Bonds. III. Further Studies on the Preparation of Olefins from Acetylenes 1,2". Journal of the American Chemical Society. 63 (10): 2683–2685. doi:10.1021/ja01855a050.
^ Hennion, G. F.; Sheehan, J. J. (June 1949). "1,2-Hexadiene". Journal of the American Chemical Society. 71 (6): 1964–1966. doi:10.1021/ja01174a017.
^ Ulan, Judith G.; Maier, Wilhelm F. (September 1989). "Mechanism of 2-hexyne hydrogenation on heterogeneous palladium". Journal of Molecular Catalysis. 54 (2): 243–261. doi:10.1016/0304-5102(89)80220-2.
^ Schrock, Richard R.; Osborn, John A. (April 1976). "Catalytic hydrogenation using cationic rhodium complexes. II. The selective hydrogenation of alkynes to cis olefins". Journal of the American Chemical Society. 98 (8): 2143–2147. doi:10.1021/ja00424a021.
^ Zuccaccia, Daniele; Belpassi, Leonardo; Rocchigiani, Luca; Tarantelli, Francesco; Macchioni, Alceo (5 April 2010). "A Phosphine Gold(I) π-Alkyne Complex: Tuning the Metal−Alkyne Bond Character and Counterion Position by the Choice of the Ancillary Ligand". Inorganic Chemistry. 49 (7): 3080–3082. doi:10.1021/ic100093n. PMID 20222666.
^ Thomas, Robert J.; Campbell, Kenneth N.; Hennion, G. F. (March 1938). "Catalytic Hydration of Alkylacetylenes 1". Journal of the American Chemical Society. 60 (3): 718–720. doi:10.1021/ja01270a061.
^ Higashimura, Toshinobu; Deng, Yun Xiang; Masuda, Toshio (March 1982). "Polymerization of 2-hexyne and higher 2-alkynes catalyzed by MoCl 5 Ph 4 Sn and WCl 6 Ph 4 Sn 1". Macromolecules. 15 (2): 234–238. Bibcode:1982MaMol..15..234H. doi:10.1021/ma00230a005.

[1] Campbell, Kenneth N.; Eby, Lawrence T. (October 1941). "The Reduction of Multiple Carbon—Carbon Bonds. III. Further Studies on the Preparation of Olefins from Acetylenes 1,2". Journal of the American Chemical Society. 63 (10): 2683–2685. doi:10.1021/ja01855a050.

[henn-2] Hennion, G. F.; Sheehan, J. J. (June 1949). "1,2-Hexadiene". Journal of the American Chemical Society. 71 (6): 1964–1966. doi:10.1021/ja01174a017.

[3] Ulan, Judith G.; Maier, Wilhelm F. (September 1989). "Mechanism of 2-hexyne hydrogenation on heterogeneous palladium". Journal of Molecular Catalysis. 54 (2): 243–261. doi:10.1016/0304-5102(89)80220-2.

[4] Schrock, Richard R.; Osborn, John A. (April 1976). "Catalytic hydrogenation using cationic rhodium complexes. II. The selective hydrogenation of alkynes to cis olefins". Journal of the American Chemical Society. 98 (8): 2143–2147. doi:10.1021/ja00424a021.

[5] Zuccaccia, Daniele; Belpassi, Leonardo; Rocchigiani, Luca; Tarantelli, Francesco; Macchioni, Alceo (5 April 2010). "A Phosphine Gold(I) π-Alkyne Complex: Tuning the Metal−Alkyne Bond Character and Counterion Position by the Choice of the Ancillary Ligand". Inorganic Chemistry. 49 (7): 3080–3082. doi:10.1021/ic100093n. PMID 20222666.

[6] Thomas, Robert J.; Campbell, Kenneth N.; Hennion, G. F. (March 1938). "Catalytic Hydration of Alkylacetylenes 1". Journal of the American Chemical Society. 60 (3): 718–720. doi:10.1021/ja01270a061.

[7] Higashimura, Toshinobu; Deng, Yun Xiang; Masuda, Toshio (March 1982). "Polymerization of 2-hexyne and higher 2-alkynes catalyzed by MoCl 5 Ph 4 Sn and WCl 6 Ph 4 Sn 1". Macromolecules. 15 (2): 234–238. Bibcode:1982MaMol..15..234H. doi:10.1021/ma00230a005.

[1]

[2]

[3]

[4]

[5]

[6]

[7]