New Insights into Re-3(mu-Cl)(3)Cl-6 Aromaticity. Evidence of sigma- and pi-Diatropicity

Abstract

We have theoretically evaluated the behavior of the Re-3(mu-Cl)(3)Cl-6 cluster under magnetic perturbation, and it clearly shows that the magnetic response within the Re-3(mu-Cl)(3) plane is highly diatropic in nature. An analysis of both the magnetically induced current density (MICD) and induced magnetic field (B-ind) allows us to classify this cluster as doubly sigma- and also pi-aromatic on the magnetic criterion. These findings contradict the classical Re-Re double bond representation and favor a chemical bonding pattern that involves delocalized bonds.