Ellipticity, PDI and FLU, Evaluation of Aromaticity Indexes During Substituting B &N Atoms in Poly-Annulene

Abstract

A close relationship between chemical shift and magnetic criteria for aromaticity arouses a deeper view for probing and modeling of induced current density in π systems through external magnetic fields. The (4n+2)π systems aromatic are studied on variants of Azabora Derivatives of [8] Annulene (BnNnC(8-2n)H8) via the localized orbital localization (LOL) and electron localized function (ELF) by considering the density functional calculation. By this work, it has been predicted a four-electron dia-tropic (aromatic) ring current for (4n+2) π variants of Bn NnC(8-2n) H8 and a two-electron para-tropic (anti-aromatic) current for (4n) π. With the HOMO and LUMO energies and also HOMO/LUMO overlapping in whole space, it is possible to predict the transition states from delocalized to-localized currents in all variant mentioned compounds in the viewpoint of aromaticity and anti-aromaticity. In addition, the nucleus independent chemical shifts (NICS), HOMA, Ellipticity, Aromatic Fluctuation index (FLU), and para delocalization index (PDI) values confirm the amounts of aromaticity and anti-aromaticity in those rings.