Alkenecontaining

Alkene-containing compounds are organic molecules that include one or more carbon–carbon double bonds (C=C). The C=C bond introduces unsaturation, affects molecular geometry, and creates a site of heightened reactivity compared with alkanes. The double bond also restricts rotation, giving rise to geometric isomerism and distinct physical properties.

Stereochemistry is a key feature of alkenes. Because the two carbon atoms of a double bond cannot freely rotate, substituents on each carbon can adopt different spatial arrangements. This leads to E/Z (formerly trans/cis) isomerism, which can influence reactivity, boiling points, and conductivity in some systems.

Common examples include simple alkenes such as ethene (ethylene) and propene, as well as more complex structures like butadiene, isoprene, styrene, vinyl chloride, and acrylonitrile. Alkenes can also appear as functional groups within larger molecules or as part of conjugated systems, influencing color, UV absorption, and reactivity.

Reactivity of alkene-containing compounds centers on the C=C bond. Typical transformations include electrophilic addition (hydrohalogenation, halogenation), hydroboration-oxidation to give alcohols, hydration, and epoxidation. Hydrogenation converts C=C to C–C single bonds. Alkenes participate in oxidation to diols and in protective or directing strategies in synthesis. Polyfunctional alkenes can undergo polymerization to form plastics, with polyolefins such as polyethylene and polypropylene being prominent examples. Olefin metathesis is another widely used transformation for constructing new alkenes.

In naming and classification, alkene-containing compounds are described as alkenes or alkenyl derivatives. Internal and terminal alkenes, and polyenes with multiple double bonds, are distinguished for both nomenclature and reactivity considerations.