Intermolecular interaction potential maps from energy decomposition for interpreting reactivity and intermolecular interactions

Abstract

The electrostatic potential (ESP) has been widely used to visualize electrostatic interactions about a molecule. However, electrostatic effects are often insufficient for capturing the entirety of an interaction or a reaction of interest. In this investigation, intermolecular interaction potential maps (IMIPs), constructed from the potentials derived from energy decomposition analysis (EDA) using density functional theory, were developed and applied to provide unique insight into molecular interactions and reactivity. To this end, rather than constructing a potential map from probe point charge interactions, IMIPs were constructed from probe interactions with small molecular fragments, including CH₃⁺, CH₃⁻, benzene, and atomic probes including alkali metals, transition metals, and halides. The interaction potentials are further decomposed producing IMIPs for each interaction component using EDA (electrostatic, orbital, steric, etc.). The IMIPs are applied to the study of various interactions including cation–π and anion–π interactions, electrophilic and nucleophilic aromatic substitution, Lewis acid activation, π-stacking, endohedral fullerenes, and select organometallics which reveal fundamental insight into the positional preferences and physical origins of the interactions that otherwise would be difficult to uncover through other surface analyses.