alkeenidest

Alkenes are a class of hydrocarbons characterized by the presence of at least one carbon-carbon double bond. The simplest alkene is ethene, with the chemical formula C2H4. The general formula for acyclic alkenes with one double bond is CnH2n. The double bond consists of one sigma bond and one pi bond, making it a region of higher electron density and therefore more reactive than a single bond. This reactivity is responsible for many of the characteristic reactions of alkenes, such as addition reactions.

The presence of a double bond gives rise to isomerism in alkenes. Geometric isomerism, also known as cis-trans isomerism, occurs when there is restricted rotation around the double bond and each carbon atom of the double bond is attached to two different groups. The cis isomer has similar groups on the same side of the double bond, while the trans isomer has them on opposite sides. Alkenes can be saturated or unsaturated. Unsaturated hydrocarbons contain double or triple bonds.

Alkenes are important intermediates in organic synthesis and are used in the production of polymers, plastics, and other organic compounds. Ethene, for instance, is a key feedstock for the production of polyethylene, one of the most widely used plastics. Other common alkenes include propene, used to make polypropylene, and butene, used in the production of synthetic rubber. The reactivity of the double bond also allows for various functionalization reactions, expanding their utility in chemical manufacturing.