Hexene

Hexene is a group of unsaturated hydrocarbons with six carbon atoms and one carbon–carbon double bond, giving the general formula C6H12. The term covers several structural isomers of hexene, including 1-hexene, 2-hexene, and 3-hexene. The double bond can be terminal (as in 1-hexene) or internal (2- and 3-hexene), and internal isomers can exhibit cis/trans (Z/E) stereochemistry in some cases.

In 1-hexene, the double bond is at the end of the chain, producing a primary alkene. In 2-hexene and 3-hexene, the double bond lies within the carbon chain, making them internal alkenes; 2- and 3-hexene can occur as stereoisomers (cis and trans) depending on the arrangement surrounding the double bond.

Hexenes are typically colorless liquids or gases at room temperature, depending on the isomer. They are flammable and have the characteristic odor of light hydrocarbons. Physical properties such as boiling point and density vary among the isomers but are generally close due to similar carbon frameworks.

Industrially, hexenes arise as components of petroleum fractions and as byproducts of refining and catalytic processes. They are valued as starting materials in organic synthesis and as comonomers in polymer production, especially 1-hexene, which is used to modify polyethylene properties in processes such as the production of linear low-density or high-density polyethylene. Hexenes can also undergo hydroformylation or hydrogenation to yield aldehydes, alcohols, or saturated hydrocarbons, serving as intermediates in various chemical syntheses.

Safety considerations include keeping hexenes away from heat, sparks, and oxidizers due to flammability; they should be stored in well-ventilated areas and handled with appropriate precautions.