Julien Pilme

In this contribution, I will present, within the framework of conceptual Density Functional Theory and based on the topological domains of the Electron Localization Function (ELF), a mechanistic methodology designed to identify the most favorable reaction pathway between frozen reactants at low computational cost. In the first part, I will show how a combined approach based on ELF topology and the condensed Dual Descriptor (DD) can be used to drive the optimal orientation between reactants and to mimic the potential energy surfaces of molecular systems at the early stages of the chemical pathway. The DD was chosen for its ability to evaluate the regioselectivity of neutral and soft species, and potentially to mimic the interaction energy arising from mutual interactions between nucleophilic and electrophilic regions. In the second part, this approach will be generalized toward a broader donor–acceptor reactivity model, which can be related to previous studies showing that molecular reactivity results from a balance between electrostatic control and electron-transfer (frontier-orbital) control. Some illustrative examples will be given for non-covalent donor–acceptor systems as well as for reactive systems. Finally, the strengths and limitations of the proposed models for predicting chemical reactivity will be outlined.