-ene

Definition

The suffix '-ene' is used in organic chemistry to indicate the presence of a carbon-carbon double bond within a molecule. It is a functional group that is a key characteristic of alkenes, a class of unsaturated hydrocarbons.

5 Must Know Facts For Your Next Test

1. The '-ene' suffix is used to indicate the presence of a carbon-carbon double bond in the parent chain of an alkene.
2. Alkenes are named by replacing the '-ane' suffix of the corresponding alkane with '-ene'.
3. The location of the double bond is indicated by a number preceding the '-ene' suffix, which denotes the position of the first carbon in the double bond.
4. Alkenes exhibit characteristic reactions, such as addition reactions, due to the reactivity of the carbon-carbon double bond.
5. The presence of a carbon-carbon double bond affects the physical and chemical properties of alkenes, including their boiling points, reactivity, and stability.

Review Questions

• Explain the role of the '-ene' suffix in the nomenclature of alkenes.
  • The '-ene' suffix is used in the IUPAC naming system to indicate the presence of a carbon-carbon double bond within the parent chain of an alkene. This suffix replaces the '-ane' ending of the corresponding alkane, signaling the unsaturated nature of the molecule. For example, the alkene with the molecular formula C\text{H}_{2}=C\text{H}_{2} would be named 'ethene', where the '-ene' suffix denotes the carbon-carbon double bond.
• Describe how the location of the carbon-carbon double bond is specified in the naming of alkenes.
  • The position of the carbon-carbon double bond in an alkene is indicated by a number preceding the '-ene' suffix. This number denotes the position of the first carbon in the double bond, starting from the end of the parent chain that results in the lowest possible number. For instance, the alkene with the structure \text{CH}_{3}-\text{CH}=\text{CH}-\text{CH}_{3} would be named '2-butene', where the '2-' prefix specifies that the double bond is located between the second and third carbon atoms in the chain.
• Analyze how the presence of a carbon-carbon double bond affects the properties and reactivity of alkenes.
  • The carbon-carbon double bond in alkenes, indicated by the '-ene' suffix, confers unique physical and chemical properties to these unsaturated hydrocarbons. The double bond makes alkenes more reactive than their saturated alkane counterparts, allowing them to undergo addition reactions that add new substituents across the double bond. Additionally, the presence of the double bond affects the boiling points of alkenes, typically resulting in higher boiling points compared to alkanes of similar molecular weight. The reactivity and physical properties of alkenes are crucial considerations in their use as important intermediates and building blocks in organic synthesis and the production of various chemicals and materials.

Related terms

Alkene: An unsaturated hydrocarbon containing at least one carbon-carbon double bond.

Unsaturated: Refers to a molecule that contains one or more carbon-carbon double or triple bonds, with fewer than the maximum possible number of hydrogen atoms.

Hydrocarbon: An organic compound consisting entirely of carbon and hydrogen atoms.