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🥼organic chemistry review

Carbon-Carbon Double Bonds

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

A carbon-carbon double bond is a covalent chemical bond in which two carbon atoms are connected by two shared pairs of electrons. This type of bond is found in many organic compounds and is particularly important in the context of olefin metathesis polymerization.

5 Must Know Facts For Your Next Test

  1. Carbon-carbon double bonds are more reactive than single bonds due to the presence of the additional shared pair of electrons.
  2. Olefin metathesis polymerization is a type of step-growth polymerization that utilizes carbon-carbon double bonds to form new polymer chains.
  3. The reactivity of carbon-carbon double bonds allows them to participate in a variety of organic reactions, including addition, substitution, and rearrangement reactions.
  4. The presence of carbon-carbon double bonds in polymers can affect the physical and mechanical properties of the material, such as flexibility, elasticity, and thermal stability.
  5. Catalysts, such as transition metal complexes, are often used to facilitate and control the olefin metathesis reactions involved in polymerization.

Review Questions

  • Explain how the reactivity of carbon-carbon double bonds is important in the context of olefin metathesis polymerization.
    • The reactivity of carbon-carbon double bonds is crucial in olefin metathesis polymerization because it allows for the rearrangement of these bonds to form new polymer chains. The metathesis reaction, facilitated by catalysts, involves the breaking and reforming of carbon-carbon double bonds, enabling the formation of larger, more complex polymer structures from smaller olefin monomers. This reactivity is a key feature that makes olefin metathesis polymerization a versatile and widely used technique in polymer chemistry.
  • Describe the role of catalysts in the olefin metathesis polymerization process and how they interact with the carbon-carbon double bonds.
    • Catalysts, such as transition metal complexes, play a crucial role in olefin metathesis polymerization by facilitating and controlling the rearrangement of carbon-carbon double bonds. These catalysts form temporary intermediates with the olefin monomers, allowing for the selective breaking and reforming of the double bonds. This catalytic activity enables the precise control over the polymerization process, allowing for the synthesis of polymers with desired properties and architectures. The interaction between the catalyst and the carbon-carbon double bonds is a key aspect of the metathesis reaction that underlies the effectiveness of olefin metathesis polymerization.
  • Analyze how the presence of carbon-carbon double bonds in polymers can influence the physical and mechanical properties of the resulting material.
    • The presence of carbon-carbon double bonds in polymers can have a significant impact on the physical and mechanical properties of the material. The double bonds can increase the flexibility and elasticity of the polymer by introducing kinks and bends in the polymer backbone, which can enhance the material's ability to deform and recover. Additionally, the double bonds can affect the thermal stability of the polymer, as they can be susceptible to thermal degradation or cross-linking reactions. Furthermore, the reactivity of the double bonds can be leveraged to introduce additional functionality or to modify the polymer's properties through post-polymerization reactions. Understanding the influence of carbon-carbon double bonds on polymer properties is crucial in the design and development of materials with tailored characteristics for specific applications.