title: Evaluation of the aromaticity of non-planar and bowl-shaped molecules by NICS criterion.
abstract: Nucleus independent chemical shift (NICS) criterion was used to gauge the amount of aromaticity in a lot of publications in two last decades. Non-planar molecules with many polygons in different sheets that make angle together have not been studied by this criterion. Perhaps, one ascribes this deficiency to NICS index, but we think it is concern to depauperation in evaluation methods. Therefore, in this work, we try to evaluate aromaticity of two fullerene substructures bowl-shaped molecules, namely corannulene and sumanene as typical non-planar molecules by using of the NICSzz-scan method. The gauge-independent atomic orbital (GIAO) NMR calculations were done at B3LYP/6-311+G(d) level of theory. Energetic criterion as another tool for evaluation of the aromaticity of compounds was used and discussed. Results shows that pentagon and hexagon rings in corannulene have antiaromatic and aromatic character, respectively and in sumanene, pentagon and outer hexagon rings have antiaromatic and aromatic character, respectively. However, the picture obtained based on the NICS computations did not provide any insight towards the real nature of current density in the corannulene and sumanene.
authors.affiliation: Department of Physical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Iran. Electronic address: areisi@kashanu.ac.ir.
authors.forename: Adel
authors.initials: A
authors.lastname: Reisi-Vanani
authors.affiliation: Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Kashan, Kashan, Iran.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Rezaei
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D037741:Fullerenes; D011084:Polycyclic Aromatic Hydrocarbons; C434863:corannulene; C505028:sumanene
keywords: Aromaticity; Fullerene substructure; Induced ring current; Non-planar polycyclic molecule; Nucleus independent chemical shift