The role of charge transfer interactions in the decomposition of organic peroxides—I: Benzoyl peroxide-amine systems in non-restricted fluid media

The influences of diphenylamine and benzidine on the rate of decomposition of dibenzoyl peroxide (DBP) were studied. The reaction was found to be second order with activation energies of 57.6 kJ/mole for the case of diphenylamine and 36.6 kJ/mole for that of benzidine. These low activation energies are attributed to charge transfer interaction between the amine donor and the peroxide acceptor. The activation energy for the case of benzidine is lower than that for diphenylamine because of the symmetrical charge transfer interaction as well as the lower ionization potential for the former. In such molecular complexes, a modification in the normal peroxide dihedral angle may occur. The activation energies are compared for decomposition of DBP molecules present in the vicinity of defect sites in single crystals.