A new scheme for electronegativity equalization as a source of electronic descriptors: application to chemical reactivity.

Recently, we have proposed a new unconventional scheme of electronegativity equalization. We assume that atomic electronegativities are equalized in a molecule in the same manner as electrical potentials in the nodes of a closed electrical network, with the molecule being represented by a molecular graph (MG). Computational procedure includes several operations over the matrices associated with MG. The only parameter used is the atomic electronegativity (EN). The method is very fast and easy-to-implement. With the help of the method one can generate a family of electronic descriptors (equalized or "effective" ENs and atomic charges) which are applicable to the treatment of some types of chemical reactivity. Quite good correlations of the descriptors obtained are observed for such thermodynamic and kinetic data as proton affinity and Taft's inductive sigma* constants. The EN equalization scheme suggested can be used as an independent tool for molecular electrostatics modeling, or can be implemented into an integrated QSAR software.