A study on the aromaticity and ring currents of polycyclic neutral oxocarbon isomers

Abstract

AbstractIn this study, topological resonance energy (TRE) methods and ring current (RC) methods were used to describe the global aromaticity of a series of polycyclic neutral oxocarbon isomers. The observed trends in aromaticity are explained. Our results obtained using the TRE method are compared with those obtained using the nucleus independent chemical shift (NICS) method as reported in the literature. The bond resonance energy (BRE) and circuit resonance energy (CRE) indices were applied to study the local aromaticity of oxocarbons. The aromaticity of the individual rings of each of the polycyclic neutral oxocarbon isomers studied was assessed using the Hückel–London ring current (RC) model. The results regarding the local aromatic and antiaromatic states of the individual rings as obtained using the BRE and CRE indices show direct correspondence with the RC results, which indicate the strength of the diatropic and paratropic currents within those rings.