Definition of a nucleophilicity scale

Jaramillo, P; Perez, P.; Contreras R.; Tiznado, W; Fuentealba P.

Abstract

This work deals with exploring some empirical scales of nucleophilicity. We have started evaluating the experimental indices of nucleophilicity proposed by Legon and Millen on the basis of the measure of the force constants derived from vibrational frequencies using a probe dipole H-X (X = F,CN). The correlation among some theoretical parameters with this experimental scale has been evaluated, The theoretical parameters have been chosen as the minimum of the electrostatic potential Vmin, the binding energy (BE) between the nucleophile and the H-X dipole, and the electrostatic potential measured at the position of the hydrogen atom VH when the complex nucleophile and dipole H-X is in the equilibrium geometry. All of them present good correlations with the experimental nucleophilicity scale. In addition, the BEs of the nucleophiles with two other Lewis acids (one hard, BF3, and the other soft, BH3) have been evaluated. The results suggest that the Legon and Millen nucleophilicity scale and the electrostatic potential derived scales can describe in good approximation the reactivity order of the nucleophiles only when the interactions with a probe electrophile is of the hard-hard type. For a covalent interaction that is orbital controlled, a new nucleophilicity index using information of the frontier orbitals of both, the nucleophile and the electrophile has been proposed. © 2006 American Chemical Society.

Más información

Título según WOS: Definition of a nucleophilicity scale
Título según SCOPUS: Definition of a nucleophilicity scale
Título de la Revista: JOURNAL OF PHYSICAL CHEMISTRY A
Volumen: 110
Número: 26
Editorial: AMER CHEMICAL SOC
Fecha de publicación: 2006
Página de inicio: 8181
Página final: 8187
Idioma: English
URL: http://pubs.acs.org/doi/abs/10.1021/jp057351q
DOI:

10.1021/jp057351q

Notas: ISI, SCOPUS