Carbon-Carbon Triple Bond

Definition

A carbon-carbon triple bond is a type of covalent bond where three pairs of electrons are shared between two carbon atoms, resulting in a very strong and stable connection. This structural feature is found in organic compounds known as alkynes and has important implications for their physical and chemical properties.

5 Must Know Facts For Your Next Test

1. The carbon-carbon triple bond is the shortest and strongest covalent bond between two carbon atoms, with a bond length of approximately 120 picometers.
2. The presence of a carbon-carbon triple bond results in a linear molecular geometry for alkyne compounds, as the three sigma bonds and one pi bond formed by the sp hybridized carbon atoms are arranged in a linear fashion.
3. Alkynes, due to their carbon-carbon triple bond, are more reactive than alkanes and alkenes, allowing them to undergo various addition reactions, such as hydrohalogenation, hydrogenation, and halogenation.
4. The carbon-carbon triple bond in alkynes is a key structural feature that contributes to their higher boiling points compared to alkanes and alkenes of similar molecular weight.
5. Acetylene, the simplest alkyne, is widely used as a fuel in welding and cutting torches due to the high energy released during its combustion reaction.

Review Questions

• Explain the relationship between sp hybridization and the structure of the carbon-carbon triple bond in acetylene.
  • The carbon-carbon triple bond in acetylene is a result of the sp hybridization of the carbon atoms. In sp hybridization, the s orbital and two p orbitals of a carbon atom combine to form three equivalent sp hybrid orbitals. These sp hybrid orbitals are used to form the sigma bonds, while the remaining p orbitals form the pi bonds of the triple bond. This sp hybridization and the resulting linear arrangement of the bonds give acetylene its characteristic linear molecular geometry.
• Describe how the presence of a carbon-carbon triple bond affects the reactivity and physical properties of alkynes compared to alkanes and alkenes.
  • The carbon-carbon triple bond in alkynes makes them more reactive than alkanes and alkenes. The triple bond is a region of high electron density, which makes alkynes susceptible to nucleophilic addition reactions. Additionally, the triple bond is shorter and stronger than the single or double bonds found in alkanes and alkenes, respectively, resulting in higher boiling points for alkynes of similar molecular weight. These unique reactivity and physical properties of alkynes are important considerations in their use and behavior in organic chemistry.
• Analyze the importance of the carbon-carbon triple bond in the industrial application of acetylene, the simplest alkyne.
  • The carbon-carbon triple bond in acetylene is crucial for its use as a fuel in welding and cutting torches. The high energy released during the combustion of acetylene is due to the breaking of the triple bond, which releases a significant amount of energy. This energy-rich nature of the carbon-carbon triple bond makes acetylene an ideal fuel for applications that require intense heat, such as welding and metal cutting. The linear molecular structure of acetylene, resulting from the sp hybridization and triple bond, also contributes to its suitability as a fuel by allowing for efficient combustion reactions.

Related terms

sp Hybridization: A type of orbital hybridization where the s orbital and two p orbitals of a carbon atom combine to form three equivalent sp hybrid orbitals, which are used to form sigma bonds.

Acetylene: The simplest alkyne, with the chemical formula C2H2, characterized by a carbon-carbon triple bond and linear molecular geometry.

Alkyne: A class of unsaturated hydrocarbons containing a carbon-carbon triple bond, which gives them unique reactivity and physical properties compared to alkanes and alkenes.