trans2butene

Trans-2-butene, also known as (E)-2-butene, is an alkene with the molecular formula C4H8. It is the trans isomer of 2-butene, in which the two methyl substituents across the double bond are on opposite sides. The compound is a colorless, flammable gas or low-boiling liquid at ambient pressure. It is less polar than its cis isomer and is generally more thermodynamically stable due to reduced steric hindrance between the substituents.

In terms of naming, trans-2-butene is the stereoisomer with the E configuration per CIP rules; cis-2-butene is the Z isomer. The two isomers have different physical properties and separation often requires distillation or selective reactions.

Trans-2-butene participates in typical alkene chemistry. It can undergo hydrogenation to yield butane, halogenation to form dihalides, and various additions across the double bond. It can be polymerized under suitable catalytic conditions to form polyolefins or used as a co-monomer in the production of modified polyolefins. It is also encountered as part of hydrocarbon mixtures from petroleum processing and can be separated from other C4 olefins by distillation and selective conversion.

Safety: trans-2-butene is flammable and should be handled with appropriate engineering controls and ventilation. It is incompatible with strong oxidizers and may form explosive mixtures when concentrated with air.