Abstract:
Following the pioneering investigations of Bader on the topology of molecular electron
density, the topology analysis of its sister field viz. molecular electrostatic potential (MESP) was
taken up by the authors’ groups. Through these studies, MESP topology emerged as a powerful tool
for exploring molecular bonding and reactivity patterns. The MESP topology features are mapped
in terms of its critical points (CPs), such as bond critical points (BCPs), while the minima identify
electron-rich locations, such as lone pairs and π-bonds. The gradient paths of MESP vividly bring out
the atoms-in-molecule picture of neutral molecules and anions. The MESP-based characterization
of a molecule in terms of electron-rich and -deficient regions provides a robust prediction about its
interaction with other molecules. This leads to a clear picture of molecular aggregation, hydrogen
bonding, lone pair–π interactions, π-conjugation, aromaticity and reaction mechanisms. This review
summarizes the contributions of the authors’ groups over the last three decades and those of the
other active groups towards understanding chemical bonding, molecular recognition, and reactivity
through topology analysis of MESP.
