The effect of parallel e xternal el ectric field on the aromaticity by density functiona l theory a pproach

Altho ugh there is no exact quantum chem ical definit ion, aromaticity is a wid ely used concept in chemistry inclu ding the theoretical ch emistry com munity. This lack of a proper definition has led to many different perceptions of aromaticity, and many indices for its quantifi cation have been introd uced. These include structural indi ces, includi ng the well-known har monic oscilla tor model of aromatic ity (HOM A)[۱], reacti vity and c onceptual density functional theory (DFT)-bas ed indices [۲], and so forth. The nucleus independent chemical shifts (NICS )[۳] suggests an increase of the molecular aromaticity from the outer toward the inner rings.Arom atic molecules exhibit characteristic responses with applie d field. Owing to its D۶h symmetry, benzene, although dev oid of a permanent elec tric dipole moment, ac quires an induced moment in the pr esence of an external electric field, which aligns the molecule in the di rection of a pplied field. Of special importance in the prese nt study, we have used NICS indices for investigation of th e effect of external electric field on the aroma ticity of benzene molecules.

کلیدواژه ها:

Aromaticity ، External electric field ، Densit y Functional Theory