1999 – 2024, a Quarter Century of the Parr’s Electrophilicity ω Index

In 1999, Robert G. Parr introduced the electrophilicity w index as a measure of the electronic stabilization of a molecule when it acquires an additional amount of electron density. Numerous theoretical studies over the last 25 years have demonstrated the usefulness of this index in the study of polar reactions. The present MEDT study reinforces the relevance of Parr’s electrophilicity w index as a quantitative measure of the electrophilic character of species involved in a polar reaction.