The Principle of Least Nuclear Motion

Abstract

This chapter outlines the principle of least nuclear motion (PLNM). The principle of least motion, states that those elementary reactions will be favored that involve the least change in atomic position and electronic configuration. Thus, the principle of least motion deals with reactivity in terms of the reactant(s) and product(s) of the reaction. When product stability effects have been accounted for, the residue will contain the PLNM effects, but it will also contain asynchronization effects and effects of differences in changes in electronic configuration. The chapter discusses the principle qualitatively in terms of the intersecting Morse curve approach. Further attention to motion toward the transition state instead of toward the product may be valuable. The effect of imperfect synchronization of changes and of non-monotonic changes taking place during a reaction should also be studied further.