Alkeenid

Alkeenid is a term used in chemistry to refer to organic compounds that contain at least one carbon-carbon double bond. These compounds are a type of unsaturated hydrocarbon, meaning they contain fewer hydrogen atoms than the corresponding saturated hydrocarbon (alkane) with the same number of carbon atoms. The general formula for an alkeen with one double bond is CnH2n, where n is the number of carbon atoms.

The presence of the carbon-carbon double bond, which consists of one sigma bond and one pi bond, makes alkeenid more reactive than alkaanid. The pi bond is weaker and more accessible to attacking reagents, leading to characteristic addition reactions. Common reactions include halogenation, hydrohalogenation, hydration, and hydrogenation. The double bond also allows for geometric isomerism, specifically cis-trans isomerism, when each carbon atom of the double bond is attached to two different groups.

The simplest alkeenid is eteen (ethylene), C2H4, which is a gas and a crucial industrial chemical used in the production of polyethylene plastics, ethylene oxide, and other organic compounds. Propene (propylene), C3H6, is another important alkeenid, used in the manufacture of polypropylene and other chemicals. Higher alkeenid such as butene and pentene also find applications in the petrochemical industry. The presence of multiple double bonds leads to subclasses like dialkeenid (two double bonds) and polyalkeenid (many double bonds).