Abstract

Nayer Mohammadian, Karim Zare and Majid Monajjemi

DOI : http://dx.doi.org/10.13005/ojc/330402

There are no works in theoretical of a statistical methodof NICS-nucleus independent chemical shift for study of heterocyclic rings, since the asymmetry¹⁵(η)and skew¹⁵(κ) parameter is fluctuated in small distance and are alternate in large distance in the center of heterocyclic rings.Through changing the asymmetriesamong 0 ≤η≤+1 skew¹⁵could be changed in the range of -1 ≤κ ≤+1 , and also the parameter κ will be zero when σ₂₂ = σ_iso¹⁵.In position of axially-symmetric tensors, σ₂₂ equals¹⁵ either σ₁₁ or σ₃₃, skewsare κ=±1. In this study, we have investigated the statistical methodsthrough nucleus-independent chemical shifts-SNICS calculations in view point of Bq motions in the center of sphere spaces of heterocyclic rings. In our previous work¹⁵, it has been exhibited that S-NICS method is an accurate method for estimation the amount of aromaticity in the non-benzene¹⁵ rings similar heterocyclic rings which are popular moleculesin organic chemical compounds as anti-cancer disease.Although NICS values for benzene and naphthalene and so on can be indicated as aromaticity criterion, for other molecules such as heterocyclic rings and their derivatives, S-NICS values are much more accurate compare to NICS index.

S-NICS; NICS; heterocyclic anticancer compounds

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