Hexadecene, sometimes called cetene in older literature, refers to hydrocarbons with the formula C16H32 that contain one carbon–carbon double bond. As members of the alkene class, hexadecenes share the general properties of unsaturated, nonpolar hydrocarbons: they are hydrophobic, soluble in organic solvents, and chemically reactive at the double bond.

Structure and isomers

The simplest way to think about hexadecene is by the position of the double bond on a 16‑carbon chain. For a straight (unbranched) chain there are positional isomers commonly numbered 1‑ through 15‑hexadecene, but by symmetry the distinct positions reduce to eight unique internal/terminal placements (1‑ through 8‑hexadecene). Terminal double bonds (alpha‑olefins such as 1‑hexadecene) differ in reactivity from internal double bonds. Internal alkenes can also exist as geometric stereoisomers (E/Z or trans/cis) when the substituents on the double bond are different.

Beyond the straight‑chain variants, a very large family of branched constitutional isomers exists: moving alkyl branches along the chain produces many distinct compounds with the same molecular formula. These branching patterns and double‑bond locations create diverse physical and chemical behaviors among members of the C16H32 set.

Physical and chemical characteristics

  • Molecular formula: C16H32; molar mass approximately 224 g·mol−1.
  • Physical state: typically colorless liquids or low‑melting waxy oils at ambient conditions, depending on isomer and purity.
  • Chemical reactivity: the carbon–carbon double bond undergoes typical alkene reactions — hydrogenation, hydroformylation, epoxidation, polymerization and halogenation — making hexadecenes useful intermediates.

Production, occurrence and uses

Hexadecenes are encountered in petroleum fractions and are produced industrially by catalytic oligomerization of ethylene, by selective cracking of longer hydrocarbons, and by targeted synthesis routes that produce alpha‑olefins. Organic chemistry and petrochemical industry processes can tailor the double‑bond position and branching to match desired applications.

Common uses include: as comonomers or modifiers in specialty polyethylene and other polymers, intermediates in surfactant and lubricant additive production, and as feedstocks for further chemical transformations (for example hydroformylation to aldehydes or epoxidation for surfactant precursors). 1‑Hexadecene (an alpha‑olefin) is particularly valuable where terminal reactivity is required.

Safety and environmental notes

Hexadecenes are flammable liquid hydrocarbons. They are of low solubility in water, tend to persist in nonpolar environmental compartments, and may pose inhalation or skin‑irritation hazards. Handling follows standard precautions for hydrocarbons: good ventilation, fire control, and appropriate personal protective equipment. Releases to the environment are managed under common petroleum/chemical regulations.

Distinctions and notable facts

  1. The name "hexadecene" designates a family rather than a single molecule; adding a locant (for example, 1‑hexadecene or 7‑hexadecene) specifies the double‑bond position.
  2. Positional isomerism (1–8 for straight‑chain symmetry) and geometric (E/Z) isomerism substantially increase the number of distinct species within C16H32.
  3. For further reading on carbon chains and isomerism see general resources about the carbon atom chemistry and isomerism in hydrocarbons.

Because hexadecenes form a bridge between commodity petrochemicals and specialty chemicals, they serve both as practical industrial feedstocks and as illustrative examples of how double‑bond placement and branching control molecular properties and applications.