REAGENT REACTIVITIES IN RADICAL ABSTRACTION REACTIONS - PHYSICAL FACTORS DETERMINING THE ACTIVATION-ENERGY

The data on the reactivities of molecules and radicals is reviewed and analyzed in terms of the parabolic model. Ten main factors are established that determine the activation energy for radical abstraction reactions: the enthalpy of a reaction, the force constants of reacting bonds, the energy of triplet repulsion, the electron affinity of the atoms of the reaction center, the polar interaction, the multidipole interaction, the pi-electrons in the vicinity of the reaction center, the atomic radius of the reaction center, steric hindrances, and the solvation of polar reagents.