2Octadecene

2-Octadecene is an organic compound in the alkene family. It is a long-chain hydrocarbon with 18 carbon atoms and a carbon–carbon double bond between the second and third carbons, giving the systematic name octadec-2-ene. The molecular formula is C18H36. As an internal alkene, 2-octadecene exists as geometric isomers around the double bond, with possible E (trans) and Z (cis) configurations; mixtures are common depending on synthesis and purification.

2-Octadecene occurs in trace quantities in some petroleum fractions and can be produced by selective dehydrogenation or oligomerization routes from longer hydrocarbons. Purified samples are typically obtained by distillation and fractionation. It is usually handled as a colorless, nonpolar liquid with low solubility in water and relatively low volatility.

Chemically, the double bond enables standard alkene reactions. It can undergo hydrogenation to give 2-octadecane, halogenation to form dihalides, hydrohalogenation, hydration, and epoxidation. Because the double bond is internal, stereochemical considerations (E/Z) influence the outcome of additions, but many laboratory procedures proceed without strict control of geometry.

Applications of 2-octadecene include use as a nonpolar solvent and as a building block for long-chain aliphatic derivatives. It serves in the formulation of specialty lubricants, coatings, and certain surfactant-related materials. In research contexts, it is used as a reactive hydrocarbon backbone for modifying surface lipophilicity or as a model substrate in studies of alkene chemistry.

Safety notes: 2-octadecene is flammable and should be handled with appropriate precautions. It may cause skin or eye irritation and should be used in well-ventilated areas away from heat or sparks.