VSEPR Theory - Multiple bonds

There is more than one bonding pair of electrons in a multiple bond but all of the electron pairs involved in a multiple bond must be in roughly the same place. Thus, for these electrons, the principle of placing the pairs as far apart from each other as possible does not make sense. Double and triple bonds get special treatment:

  • For each double bond around the central atom subtract one from the VSEP count
    • Typically a lone outer oxygen atom will make a double bond as it needs to share two extra electrons to complete a stable outer shell electron configuration.
  • For each triple bond around the central atom subtract two from the VSEP count
    • Typically a lone outer nitrogen atom will make a triple bond as it needs to share three extra electrons to complete a stable outer shell electron configuration.

Bond angles will deviate from their ideal values according to the following rules:

  • Triple bonds repel other bonding-electrons more strongly than double bonds.
  • Double bonds repel other bonding-electrons more strongly than single bonds.

Examples

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