Generalized Polansky Index as an aromaticity measure in polycyclic aromatic hydrocarbons (original) (raw)
Related papers
Omega and Cluj-Ilmenau Indices of Hydrocarbon Molecules “Polycyclic Aromatic Hydrocarbons PAHk”
Computational Chemistry, 2016
A topological index is a numerical value associated with chemical constitution for correlation of chemical structure with various physical properties, chemical reactivity or biological activity. In this paper, we computed the Omega and Cluj-Ilumenau indices of a very famous hydrocarbon named as Polycyclic Aromatic Hydrocarbons k PAH for all integer number k.
CTED: the new aromaticity index based on corrected total electron density at bond critical points
Journal of Physical Organic Chemistry, 2014
In this work, the aromaticity of polycyclic benzene rings was evaluated by the calculation of g-factor for a hydrogen placed perpendicularly at geometrical center of related ring plane at a distance of 1.2Å. The results have compared with the other commonly used aromatic indices, such as HOMA, NICSs, PDI, FLU, MCI, CTED and, generally been found to be in agreement with them. So, it was proposed that the calculation of the average g-factor as g could be applied to study the aromaticity of polycyclic benzene rings without any restriction in the number of benzene rings as a new magnetic-based aromaticity index.
Δg: The new aromaticity index based on g-factor calculation applied for polycyclic benzene rings
Chemical Physics Letters, 2015
In this work, the aromaticity of polycyclic benzene rings was evaluated by the calculation of g-factor for a hydrogen placed perpendicularly at geometrical center of related ring plane at a distance of 1.2Å. The results have compared with the other commonly used aromatic indices, such as HOMA, NICSs, PDI, FLU, MCI, CTED and, generally been found to be in agreement with them. So, it was proposed that the calculation of the average g-factor as g could be applied to study the aromaticity of polycyclic benzene rings without any restriction in the number of benzene rings as a new magnetic-based aromaticity index.
Journal of Computational Chemistry, 2007
The relative aromaticity of benzenoid rings in the linear polyacenes is investigated using two novel aromaticity approaches. According to the first, the aromaticity of individual benzene rings was gauged by the values of six-center bond indices (SCI) calculated within the so-called Generalized Population Analysis (GPA). In the second approach, the same goal is addressed using the theory of Molecular Quantum Similarity (MQS). Both independent approaches are found to correlate very well, and both point toward decreasing aromaticity in any linear polyacenes upon going from the outer to inner rings. q 2006 Wiley Periodicals, Inc. J Comput Chem 28: 152-160, 2007
Correlations between Local Aromaticity Indices of Bipartite Conjugated Hydrocarbons
The Journal of Physical Chemistry A, 2010
Local aromaticity in rings of conjugated hydrocarbons can be measured in a variety of ways. In the present paper, we concentrate on two of these, namely, EC, i.e., the π-electron content or π-electron partition, and ef, the energy effect of cycles. For the central ring in five bipartite conjugated hydrocarbons (anthracene, triphenylene, perylene, coronene, and biphenylene), it was found that EC and ef values are modified in a consistent and predictable manner by annelation with benzenoid rings. Equations are presented for computing EC and ef values for the central ring in terms of three integers representing the numbers of annelated benzenoid rings (A, L, and G for angular, linear, and geminal annelation, respectively). The coefficients of A and G are positive (A > G) and the coefficient of L is negative for benzenoids, but for biphenylene, the situation is reversed for coefficients in the correlation for ef values.
On some leap indices of Polycyclic Aromatic Hydrocarbons (PAHs)
Journal of Discrete Mathematical Sciences and Cryptography, 2020
Graph invariants are numerical values assigned to some molecular graph G M to characterize its topological properties. The second neighbourhood or a 2-distance degree of any vertex v in a graph G M is the cardinality of its second neighbors. In this research article, we formulated some expressions for the leap Zagreb indices, leap hyper-indices and F-leap indices, depending on the second degree of a vertex, of a family of a molecular graph called Polycyclic Aromatic Hydrocarbons PAH s .
The extent of unsaturation level in a compound, commonly measured in terms of its number of double bond equivalents (DBEs), reflects the total number of p bonds plus rings and can be calculated if the molecular formula is known. The extent of unsaturation can also be calculated via DBE/C, where C is the number of carbon atoms. For hydrocarbons, if DBE/C is > 0.67, the structure corresponds unequivocally to a condensed aromatic (CA) compound, but this criterion cannot be applied directly to heteroatom containing compounds. A new parameter, the aromaticity index (AI) was recently proposed to solve this problem, and has been applied to establish a region of CA compounds in high resolution mass spectrom-etry (MS) van Krevelen diagrams to characterize natural organic matter (NOM), such as humic acids (HAs). In this study, we report a reformulated AI (rAI) that also considers formulae that accommodate non-aromatic (NA) and non-condensed aromatic (NCA) cyclic carbonyl compounds. We also propose a correction for AI with respect to N and P containing formulae and show an application of the rAI index for the analysis and data treatment of a certified reference material (CRM) of NOM.
The aromatic fluctuation index (FLU): A new aromaticity index based on electron delocalization
The Journal of chemical physics, 2005
In this work, the aromatic fluctuation index ͑FLU͒ that describes the fluctuation of electronic charge between adjacent atoms in a given ring is introduced as a new aromaticity measure. This new electronic criterion of aromaticity is based on the fact that aromaticity is related to the cyclic delocalized circulation of electrons. It is defined not only considering the amount of electron sharing between contiguous atoms, which should be substantial in aromatic molecules, but also taking into account the similarity of electron sharing between adjacent atoms. For a series of rings in 15 planar polycyclic aromatic hydrocarbons, we have found that, in general, FLU is strongly correlated with other widely used indicators of local aromaticity, such as the harmonic-oscillator model of aromaticity, the nucleus independent chemical shift, and the para-delocalization index ͑PDI͒. In contrast to PDI, the FLU index can be applied to study the aromaticity of rings with any number of members and it can be used to analyze both the local and global aromatic character of rings and molecules. Downloaded 02 Dec 2010 to 84.88.138.106. Redistribution subject to AIP license or copyright; see http://jcp.aip.org/about/rights\_and\_permissions 014109-2 Matito, Duran, and Solà J. Chem. Phys. 122, 014109 (2005) Downloaded 02 Dec 2010 to 84.88.138.106. Redistribution subject to AIP license or copyright; see http://jcp.aip.org/about/rights\_and\_permissions 014109-7 New aromaticity index J. Chem. Phys. 122, 014109 (2005) Downloaded 02 Dec 2010 to 84.88.138.106. Redistribution subject to AIP license or copyright; see http://jcp.aip.org/about/rights\_and\_permissions
Computing Sanskruti index of the Polycyclic Aromatic Hydrocarbons
Geology, Ecology, and Landscapes
Among topological descriptors topological indices are very important and they have a prominent role in chemistry. One of them is Sanskruti index was introduced by Hosamani and defined as S(G) = ∑ uv∈E(G) � S u S v S u +S v −2 � 3 where Su is the summation of degrees of all neighbors of vertex u in G. In this paper we compute this new topological index for Polycyclic Aromatic Hydrocarbons PAH k .