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Updated: Apr 20, 2026

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Effect of benzo-annelation on local aromaticity in heterocyclic conjugated compounds
Slavko Radenković1, Jelena Kojić, Jelena Petronijević
1Faculty of Science, University of Kragujevac , 12 Radoja Domanovića, 34000 Kragujevac, Serbia.
Abstract:
The effect of benzo-annelation on the local aromaticity of the central ring of acridine (1), 9H-carbazole (2), dibenzofuran (3), and dibenzothiophene (4) was analyzed by means of the energy effects (ef), pairwise energy effects (pef), multicenter delocalization index (MCI), electron density at ring critical points (ρ(r(C))), harmonic oscillator model of aromaticity (HOMA), and nucleus independent chemical shifts (NICS). According to energetic, electron delocalization, and geometrical indices, angular benzo-annelation increases, whereas linear benzo-annelation decreases, the extent of the local aromaticity of the central ring containing heteroatoms. The local aromaticity of the central heterocyclic ring in the examined molecules can significantly vary by applying different modes of benzo-annelation. The NICS values do not always support the results obtained by the other aromaticity indices and, in some cases, lead to completely opposite conclusions.
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