Kinetic and mechanistic studies of the nonchain radical nucleophilic substitution reactions

Article abstract of DOI:10.1021/jo00078a010

The kinetics of the radical nucleophilic substitution reaction of p- nitrochlorobenzene with the sodium salt of the ethyl α-cyanoacetate carbanion in dimethyl sulfoxide (DMSO) solution at 335.9, 340.1, 343.9, 347.7, and 351.4 K were determined by observing the increase of the UV- visible absorbance of the product, the ethyl α-cyano-α-(p- nitrophenyl)acetate carbanion. The activation energies and entropies for the single electron transfer (k₁) and for the p-nitrochlorobenzene radical anion dissociation (k₂) were obtained. These results strongly support the previous conclusion that the thermal nucleophilic substitution reactions of o- and p- nitrohalobenzenes with the sodium salt of ethyl α-cyanoacetate carbanion in DMSO solution proceed exclusively via a nonchain radical mechanism (Scheme II).