Multidimensionality of delocalization indices and nucleus independent chemical shifts in polycyclic aromatic hydrocarbons.
J Comput Chem
; 29(3): 358-66, 2008 Feb.
Article
em En
| MEDLINE
| ID: mdl-17631652
ABSTRACT
The aromaticity and local-aromaticity of a large set of polycyclic aromatic hydrocarbons (PAHs) is studied using multicenter delocalization indices from generalized population analysis and the popular nucleus independent chemical shift (NICS) index. A method for the fast computation of the NICS values is introduced, using the so-called pseudo-pi-method. A detailed examination is made of the multidimensional nature of aromaticity. The lack of a good correlation between the NICS and the multicenter delocalization indices is reported and the grounds discussed. It is shown through a thorough statistical analysis that the NICS values arise not only from local aromaticity of the benzenoid rings, but also from other circuits. It is shown that the NICS indices do not reveal the individual aromatic nature of a specific ring, contrary to the delocalization indices.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hidrocarbonetos Policíclicos Aromáticos
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article