Probing molecular environments with a Fictitious isotopic dipole

TL;DR

This paper introduces a novel isotopic dipole probe for analyzing molecular environments, offering high accuracy in detecting electrostatic fields and reactive sites, outperforming some ab initio methods.

Contribution

A new fictitious isotopic dipole method is proposed for probing molecular environments with improved accuracy over existing approaches.

Findings

Effective in hydrogen, water, benzene, chlorobenzene, and frustrated Lewis pairs.

Provides detailed information on electrostatic fields and reactive sites.

Superior accuracy compared to some ab initio methods.

Abstract

A HD-like isotopic dipole moment is proposed as a sensible probe for molecular environments, in particular for electrostatic fields and polarizable (reactive) sites of molecules. Fictitious nuclear masses are chosen in order to yield a rigid dipole with appropriate magnitude. Upon subtracting the Born-Oppenheimer energy, the interaction is reduced to the Field-dipole-like and the dipole-polarizability-like terms, the last one being particularly informative since connected to potentially reactive sites. The Field strength and orientation are easily obtained by identifying the minimum Field-dipole energy configuration and flipping the dipole from it. In this case the method appears to have a superior accuracy in comparison with ab initio approaches. In tests with hydrogen, water, benzene and chlorobenzene molecules and with a frustrated Lewis pair, the potential of the method is assessed.