Multidimensionality of delocalization indices and nucleus-independent chemical shifts in polycyclic aromatic hydrocarbons II: Proof of further nonlocality

Stijn Fias, Sofie Van Damme, Patrick Bultinck

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

In a recent contribution, we examined the effect of 10- and 14-center circuits on the nucleus-independent chemical shifts NICSs using multicenter bond indices (MCBIs) (Fias et al., J Comput Chem 2008,29,358). In this study, the nonlocal contributions to the NICS are further investigated for a larger set of polycyclic aromatic hydrocarbons (PAHs). To achieve this, the NICSs are predicted using the MCBI and compared with ab initio results. The NICSs of the central ring of perylene- and benzo-[ghi]perylene-like fragments and of coronene appear to have other nonlocal contributions than the ones previously studied. It is shown that a model based on the MCBI-ring current maps and the inclusion of new circuits proves the existence and shows the nature of these new nonlocal effects on the NICS. This new model leads to a better understanding of the differences between the NICSs and derealization indices. The results show that the NICS value is not only significantly influenced by the higher order circuits encircling the ring at which it is evaluated but also by the local aromaticity of the surrounding rings, and occasionally, like in the case of coronene, the NICSs are even influenced by currents farther away in the molecule.

Original languageEnglish
Pages (from-to)2286-2293
Number of pages8
JournalJournal of Computational Chemistry
Volume31
Issue number12
DOIs
Publication statusPublished - 1 Sep 2010

Keywords

  • Aromaticity
  • Multicenter bond index
  • Multidimensionality of aromaticity
  • NICS. Generalized population analysis

Fingerprint

Dive into the research topics of 'Multidimensionality of delocalization indices and nucleus-independent chemical shifts in polycyclic aromatic hydrocarbons II: Proof of further nonlocality'. Together they form a unique fingerprint.

Cite this