D2BIA—flexible, not (explicitly) arbitrary and reference/structurally invariant—a very effective and improved version of the D3BIA aromaticity index

2017 ◽  
Vol 23 (9) ◽  
Author(s):  
Caio Lima Firme ◽  
Diógenes Mendes Araújo
Keyword(s):  
Aromaticity Index

Quantitative Structure-Property Relationship (QSPR) Study of the Hydrophobicity of Phenols and 2-(Aryloxy-a-acetyl)-phenoxathiin Derivatives

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Adrian Beteringhe ◽  
Ana Cristina Radutiu ◽  
Titus Constantinescu ◽  
Luminita Patron ◽  
Alexandru T. Balaban
Keyword(s):  
Water Solubility ◽  
Molecular Descriptors ◽  
Log P ◽  
Structure Property ◽  
Substituted Phenols ◽  
Reverse Phase ◽  
Aromaticity Index ◽  
Structure Property Relationship ◽  
Layer Chromatography ◽  
Energy Of Formation

In a preceding study, the molecular hydrophobicity (RM0) was determined experimentally from reverse-phase thin-layer chromatography data for several substituted phenols and 2-(aryloxy-a-acetyl)-phenoxathiin derivatives, obtained from the corresponding phenoxides and 2-(a-bromoacetyl)-phenoxathiin. QSPR correlations for RM0 were explored using four calculated molecular descriptors: the water solubility parameter (log Sw), log P, the Gibbs energy of formation (DGf), and the aromaticity index (HOMA). Triparametric correlations do not improve substantially the biparametric correlation of RM0 in terms of log Sw and HOMA.

On splitting of the NICS(1) magnetic aromaticity index

RSC Advances ◽  
2016 ◽  
Vol 6 (28) ◽  
pp. 23900-23904 ◽  
Author(s):  
Jan Cz. Dobrowolski ◽  
Piotr F. J. Lipiński
Keyword(s):  
Aromaticity Index ◽  
Ring Center ◽  
Two Indices

The NICS(1) magnetic aromaticity index is split into NICS(1) and NICS(−1) indices when the points 1 Å above and below the ring center are inequivalent by symmetry. The two indices characterize the aromaticity of the two ring faces rather than the ring itself.

A theoretical scheme of annulenes aromaticity

1984 ◽  
Vol 49 (4) ◽  
pp. 920-935 ◽  
Author(s):  
Jaroslav Leška ◽  
Dušan Loos
Keyword(s):  
Ring Size ◽  
Aromaticity Index ◽  
Theoretical Scheme ◽  
Quantitative Results

An aromaticity scheme for annulenes is developed and applied on set of [6] to [18]annulenes. The dependence of annulenes aromaticity on the ring size, noncoplanarity and strain is considered which factors are in the aromaticity indices HOMAW and HOMAM implicitely included. The decrease in aromaticity index with increasing ring size was modelled for [4n+2] and [4n] annulenes by the functions Δ4n+2(N) and Δ4n(N). Two quantities, κd and νs, as the average measures of noncoplanarity and strain have been defined. Significant correlations of the differences Δx(N) - HOMAW and Δx(N) - HOMAM, which represent the decrease in aromaticity index by noncoplanarity and strain, with a function of the parameters κd and νs, have been obtained. The quantitative results show that not only the [4n]annulenes, but also the large part of the [4n+2]annulenes are antiaromatic, even for the presence of noncoplanarity and strain in the molecules.

1-[(1-Ethoxypropylidene)amino]-2-ethyl-4-(4-hydroxybenzyl)imidazol-5(4H)-one

2012 ◽  
Vol 68 (3) ◽  
pp. o141-o143
Author(s):  
Krzysztof Ejsmont ◽  
Agnieszka Kudelko ◽  
Wojciech Zieliński
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Harmonic Oscillator ◽  
Title Compound ◽  
Electron Delocalization ◽  
Aromaticity Index ◽  
Compound C ◽  
Harmonic Oscillator Model ◽  
Catalytic Quantity ◽  
Single Bonds

The racemic title compound, C17H23N3O3, isolated from the reaction of L-(−)-tyrosine hydrazide with triethyl orthopropionate in the presence of a catalytic quantity ofp-toluenesulfonic acid (p-TsOH), crystallizes withZ′ = 1 in a centrosymmetric monoclinic unit cell. The molecule contains two planar fragments,viz.the benzene and imidazole rings, linked by two C—C single bonds. The dihedral angle between the two planes is 59.54 (5)° and the molecule adopts a synclinal conformation. The HOMA (harmonic oscillator model of aromaticity) index, calculated for the benzene ring, demonstrates no substantial interaction between the two π-electron delocalization regions in the molecule. In the crystal structure, there is an O—H...N hydrogen bond that links the molecules along thecaxis.

Validation of the recently developed aromaticity index D3BIA for benzenoid systems. Case study: acenes

2015 ◽  
Vol 21 (9) ◽  
Author(s):  
Diógenes Mendes Araújo ◽  
Tamires Ferreira da Costa ◽  
Caio Lima Firme
Keyword(s):  
Aromaticity Index

A reformulated aromaticity index equation under consideration for non-aromatic and non-condensed aromatic cyclic carbonyl compounds

2016 ◽  
Vol 95 ◽  
pp. 29-33 ◽  
Author(s):  
Jose J. Melendez-Perez ◽  
Mónica J. Martínez-Mejia ◽  
Marcos Nogueira Eberlin
Keyword(s):  
Carbonyl Compounds ◽  
Aromaticity Index

scholarly journals A QSPR study of hydrophobicity of phenols and 2-(aryloxy-α-acetyl)-phenoxathiin derivatives using the topological index ZEP

2013 ◽  
Vol 22 (1) ◽  
pp. 33-40
Author(s):  
ZOITA-MARIOARA BERINDE ◽  
Keyword(s):  
Topological Index ◽  
Water Solubility ◽  
Log P ◽  
Gibbs Energy Of Formation ◽  
Structure Property ◽  
Aromaticity Index ◽  
Physico Chemical ◽  
Structure Property Relationship ◽  
Qspr Study ◽  
Energy Of Formation

The molecular hydrophobicity (RMO) of several newly synthesized phenoxathiin derivatives and of phenols with congeneric structures have been recently correlated with some simple physico-chemical calculated parameters of compounds: the water solubility (log Sw); the partition coefficient (log P); the Gibbs energy of formation (∆Gf ), and the aromaticity index (HOMA) [Beteringhe, A., Radutiu, A. C., Constantinescu, T., Patron, L. and Balaban, A. T., Quantitative Structure-Property Relationship (QSPR) study of the hydrophobicity of phenols and 2-(aryloxy-α-acetyl)- phenoxathiin derivatives, Rev. Chim. (Bucures¸ti) , 59 (2008), No. 11, 1175–1179]. The best correlation was found as a biparametric regression equation in terms of log Sw and HOMA, which cannot be improved by adding one or two of the parameters aforementioned. In the present work we describee the weighted electronic distance based topological index (ZEP) and then use it for QSPR studies of RMO in combination with log Sw, log P, ∆Gf and HOMA. Most of the three parameter QSPR correlations of RMO are significantly improved by involving the theoretical parameter ZEP.

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