Collect. Czech. Chem. Commun. 1997, 62, 1821-1831

Electron Reorganization in Chemical Reactions. Bond Order Conservation vs Multicenter Bonding in the Course of Chemical Reactions

Robert Ponec

Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic,165 02 Prague 6-Suchdol, Czech Republic


The conditions underlying the applicability of the empirical BEBO relationship were analyzed and discussed. It has been shown that the relationship holds for reactions in which the electron reorganization can satisfactorily be described by the classical structural theory as a simple shift of bonds. On the other hand, if the electron reorganization is more complex, the BEBO relationship is likely to fail. In these cases, the description of the structure of the transition state requires to invoke the concept of multicenter bonding.

Keywords: Bond energy-bond order; Multicenter bonding; Bond order conservation; Pair population analysis; Bond theory; Transition states.