Functional Group Pi bond is the functional group. More reactive than sigma bond. Bond dissociation energies: >C=C BDE 611 kJ/mol >C-C BDE -347 kJ/mol >Pi bond 264 kJ/mol => Chapter 7 3 Chapter 7 3 Functional Group • Pi bond is the functional group. • More reactive than sigma bond. • Bond dissociation energies: ➢C=C BDE 611 kJ/mol ➢C-C BDE -347 kJ/mol ➢Pi bond 264 kJ/mol =>