Collect. Czech. Chem. Commun. 1993, 58, 1751-1760

Topological Aspects of Chemical Reactivity. Electron Correlation in the Course of Chemical Reactions

Robert Ponec and Martin Strnad

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


The second order similarity index gRP, which has been proposed recently as a new means for a qualitative characterization of correlation effects in chemical reactivity, was generalized by incorporation into a topological model of the overlap determinant method. The resulting approach, which provides information about the variation of electron correlation during chemical reactions, was applied to the investigation of several selected pericyclic reactions. Consistent with what can be expected, the role of electron correlation was found to be the most critical for transition states of other transient species near the top of the energy barrier. The systematic differences in the extent of electron correlation between allowed and forbidden reactions are also discussed.