Hydrocarbons with at least one carbon-carbon double bond are referred to as alkenes, or olefins. Unlike alkanes, which only have single bonds, alkenes have double bonds, which give them special chemical characteristics and reactivity patterns. Ethylene (C2H4) is the most basic alkene; it is made up of two carbon atoms..
Hydrocarbons with at least one carbon-carbon double bond are referred to as alkenes, or olefins. Unlike alkanes, which only have single bonds, alkenes have double bonds, which give them special chemical characteristics and reactivity patterns. Ethylene (C2H4) is the most basic alkene; it is made up of two carbon atoms joined by a double bond, with each carbon atom also bound to two hydrogen atoms.Organization and Compatibility Alkenes have a single pi (π) bond and a single sigma (σ) bond that make up the carbon-carbon double bond. Whereas the side-to-side overlap of unhybridized p orbitals forms the π bond, the head-on overlap of sp² hybrid orbitals forms the σ bond. This double bond causes geometric isomerism, also known as cis-trans isomerism, by limiting rotation around the carbon-carbon axis. The substituents on the double bond's carbon atoms are on the same side in a cis isomer and on the opposite side in a trans isomer.Physical Characteristics Since alkenes are typically nonpolar molecules, water does not dissolve them and they dissolve in nonpolar solvents. Because their Van der Waals forces are smaller than those of alkanes with equal molecular weights, they often have lower melting and boiling temperatures. Physical characteristics like density and refractive index are also impacted by the presence of the double bond and are generally higher than those of equivalent alkanes.Reactions and Reactivity Alkenes have a high electron density site in their double bond, which makes them reactive to electrophiles. This causes the π bond to break and new σ bonds to form in a number of addition processes. Typical responses consist of:Hydrogenation is the process of turning alkenes into alkanes by adding hydrogen (H2), usually with the help of a metal catalyst such as platinum or palladium.Halogenation is the process of forming vicinal dihalides by adding halogens (X2, where X is Cl, Br, etc.).Hydrohalogenation is the process of forming alkyl halides by adding hydrogen halides (HX).Hydration is the process of forming alcohols by adding water (H2O) and an acid catalyst.Uses Alkenes are fundamental to organic synthesis as well as industrial chemistry. A crucial raw material for the creation of polyethylene, a common plastic, is ethylene. Another significant alkene is propylene, which is utilized in the synthesis of acrylonitrile, polypropylene, and other compounds. Alkenes are also used as intermediates in the synthesis of polymers, alcohols, and other organic molecules, which emphasizes their utility and significance in the production of chemicals.
Alkene stubs, alkenes, and 2-methylbutanol are essential in chemical synthesis. Alkene stubs and alkenes participate in polymerization and addition reactions. 2-Methylbutanol is used as a solvent and in the production of various chemicals.
