A Multiphilic Descriptor for Chemical Reactivity and Selectivity

TL;DR

This paper introduces a multiphilic descriptor based on local philicity functions that can simultaneously explain nucleophilicity and electrophilicity at atomic sites, aiding in understanding chemical reactivity and selectivity.

Contribution

It proposes a new multiphilic descriptor and nucleophilicity excess, extending previous concepts to better predict reactivity and analyze reaction pathways.

Findings

Successfully tested on various systems and reactions.

Analyzed force profiles in representative cases.

Extended to intra- and intermolecular reactivities.

Abstract

In line with the local philicity concept proposed by Chattaraj et al. (Chattaraj, P. K.; Maiti, B.; Sarkar, U. J. Phys. Chem. A. 2003, 107, 4973) and a dual descriptor derived by Toro-Labbe and coworkers (Morell, C.; Grand, A.; Toro-Labbe, A. J. Phys. Chem. A. 2005, 109, 205), we propose a multiphilic descriptor. It is defined as the difference between nucleophilic (Wk+) and electrophilic (Wk-) condensed philicity functions. This descriptor is capable of simultaneously explaining the nucleophilicity and electrophilicity of the given atomic sites in the molecule. Variation of these quantities along the path of a soft reaction is also analyzed. Predictive ability of this descriptor has been successfully tested on the selected systems and reactions. Corresponding force profiles are also analyzed in some representative cases. Also, to study the intra- and intermolecular reactivities another related descriptor namely, the nucleophilicity excess (DelW-+) for a nucleophile, over the electrophilicity in it has been defined and tested on all-metal aromatic compounds.