Functional Group Pi bond is the functional group More reactive than sigma bond Bond dissociation energies >C=C BDE 146 kcal/mol >C-C BDE -83 kcal/mol >Pi bond 63 kcal/mol Chapter 7Chapter 7 2 Functional Group • Pi bond is the functional group. • More reactive than sigma bond. • Bond dissociation energies: ➢C=C BDE 146 kcal/mol ➢C-C BDE -83 kcal/mol ➢Pi bond 63 kcal/mol =>