Abstract

In analogy with Sanderson's electronegativity equalization principle, it is possible to postulate a principle of spin potential equalization in the E[Na, Nß] representation of the spin polarized density functional theory, where Na and Nß refer to the number of electrons with spins a and ß, respectively. The principle provides simple expressions to evaluate the energy changes AE between two interacting molecules, A and B, together with the electron transfer, ?Na and ?Nß. The model is illustrated for a series of addition reactions of electrophilic, nucleophilic, and ambiphilic carbenes to alkenes in their singlet and triplet multiplicities. The results are in a consistent qualitative agreement with the experimental reactivity established for these systems. © 2009 American Chemical Society.