A Thermodynamic Assessment on the Reaction of Aromatic Amines Versus Reactivity with p-Benzoquinone from a Kinetic Study

Abstract

The investigated aromatic amine-quinone reaction was found to proved kinetically as a second order reaction. Reactivities of amines towards addition to p-benzoquinone have been determined by individual rate measurements and carefully elucidated in terms of (i) electronic and mesomeric effects,(ii) the standard free energy change AG0,(iii) the fraction of activated molecules (N*/N): Informations streaming from different sources were found to indicate that electron repelling groups tend to increase the reaction rate, whereas electron withdrawing groups decrease it. A substituent effect (ρ=—1.5) has been observed. The thermodynamic activation parameters of the reaction were determined and AS* was found to be a linear function of AH* which points to the occurence of the same mechanism for the investigated reaction using different aromatic amines.