Nucleus-Independent Chemical Shift Criterion for Aromaticity in Some of the Corannulene Derivatives as Carbon Nanostructure: Effect of Substituent Groups on Aromaticity

Abstract

Substitution of the peripheral H atoms in the corannulene molecule as a carbon nanostructure by OH, CH3, NH2, and NO2 groups was done and the obtained structures were optimized employing MP2/6-31G(d) level of theory. Calculations of the nucleus-independent chemical shift (NICS) were performed to analyze the aromaticity of the corannulene rings and its derivatives upon substitution at B3LYP/6-311+G(d) level of theory. Comparison of NICS(1)zz for concave and convex sides of corannulene derivatives indicated that substitution of H atoms in the corannulene molecule with OH, CH3, NO2, and NH2 groups leads to decreasing of the aromaticity character of corannulene. We discussed about two efficient factors on the aromaticity and antiaromaticity of polycyclic aromatic compounds: electron donating or withdrawing and resonance effects. We showed that NICS values in all structures are strongly dependent on the type, number, and position of the substituted groups.