Roles of Kinetic and Potential Energies in Conjugation. I. A Study of Prototypes

Abstract

Abstract The analysis of the potential and kinetic energy changes between conjugative and nonconjugative structure in vinylamine and nitroethene led to the conclusion that there were two different types of conjugations: the conjugative stability caused by a decrease in the kinetic energy and that given by a decrease in the potential energy. Those two types could be termed conjugations of kinetic energy origin and potential energy origin respectively. The cojugative stability in vinylamine is produced by an excess decrease in the kinetic energy over the increase in the potential energy (kinetic energy origin), which was attributed to a release of the kinetic energy pressure of the lone pair of electrons on nitrogen. On the other hand, the conjugation of nitroethene causes an overwhelming decrease in the potential energy, especially in that belonging to the nitro group (potential energy origin).