Is coronene better described by Clar's aromatic π‐sextet model or by the AdNDP representation?

• Published in: Journal of computational chemistry 2017-07, Vol.38 (18), p.1606-1611
• Main Authors: Kumar, Anand, Duran, Miquel, Solà, Miquel
• Format: Article
• Language: English
• Subjects: adaptative natural density partitioning; aromatic fluctuation index; Aromaticitat (Química); Aromaticity (Chemistry); Clar's aromatic π‐sextet; Density functionals; Diels-Alder reaction; Diels-Alder, Reacció de; Diels–Alder; Funcional de densitat, Teoria del; harmonic oscillator model of aromaticity; nucleus independent chemical shift; para‐delocalization index
• ISSN: 0192-8651; 1096-987X
• DOI: 10.1002/jcc.24801

The bonding patterns in coronene are complicated and controversial as denoted by the lack of consensus of how its electronic structure should be described. Among the different proposed descriptions, the two most representative are those generated by Clar's aromatic π‐sextet and adaptative natural density partitioning (AdNDP) models. Quantum‐chemical calculations at the density functional theory level are performed to evaluate the model that gives a better representation of coronene. To this end, we analyse the molecular structure of coronene, we estimate the aromaticity of its inner and outer rings using various local aromaticity descriptors, and we assess its chemical reactivity from the study of the Diels–Alder reaction with cyclopentadiene. Results obtained are compared with those computed for naphthalene and phenanthrene. Our conclusion is that Clar's π‐sextet model provides the representation of coronene that better describes the physicochemical behavior of this molecule. © 2017 Wiley Periodicals, Inc. The nature of the chemical bonding in coronene is controversial. Comparison of predictions derived from Clar's aromatic π‐sextet and Adaptative Natural Density Partitioning (AdNDP) models reveals that Clar's π‐sextet model provides a representation that better describes the physicochemical behaviour of coronene.