alkenek

Alkenes are a class of organic compounds characterized by the presence of at least one carbon-carbon double bond. Their general formula is CnH2n, where n is an integer greater than or equal to 2. This double bond is a region of high electron density, making alkenes more reactive than their saturated counterparts, alkanes. The presence of the double bond restricts the rotation of atoms around it, leading to the possibility of geometric isomerism, specifically cis-trans isomerism, in some alkenes.

The simplest alkene is ethene (C2H4), also known as ethylene. Larger alkenes are named systematically using a numbering system that indicates the position of the double bond within the carbon chain. For example, but-1-ene has a double bond between the first and second carbon atoms, while but-2-ene has it between the second and third. Alkenes undergo various characteristic reactions, including addition reactions across the double bond. Common examples include hydrogenation, where hydrogen is added to form alkanes, and halogenation, where halogens like bromine or chlorine are added. Electrophilic addition is a prevalent mechanism for many of these reactions. Alkenes are important industrial chemicals, serving as monomers for the production of polymers like polyethylene, and as intermediates in the synthesis of other organic compounds.