scholarly journals Computational Analysis of Imbalance-Based Irregularity Indices of Boron Nanotubes

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 678
Author(s):  
Yang ◽  
Munir ◽  
Rafique ◽  
Ahmad ◽  
Liu

. Molecular topology provides a basis for the correlation of physical as well as chemical properties of a certain molecule. Irregularity indices are used as functions in the statistical analysis of the topological properties of certain molecular graphs and complex networks, and hence help us to correlate properties like enthalpy, heats of vaporization, and boiling points etc. with the molecular structure. In this article we are interested in formulating closed forms of imbalance-based irregularity measures of boron nanotubes. These tubes are known as α-boron nanotube, triangular boron nanotubes, and tri-hexagonal boron nanotubes. We also compare our results graphically and come up with the conclusion that alpha boron tubes are the most irregular with respect to most of the irregularity indices.

2016 ◽  
Vol 94 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Muhammad Imran ◽  
Abdul Qudair Baig ◽  
Haidar Ali

Topological indices are numerical parameters of a graph that characterize its molecular topology and are usually graph invariant. In a QSAR/QSPR study, the physico-chemical properties and topological indices such as the Randić, atom–bond connectivity (ABC), and geometric–arithmetic (GA) indices are used to predict the bioactivity of chemical compounds. Graph theory has found a considerable use in this important area of research. All of the studied interconnection networks in this paper are constructed by the Star of David network. In this paper, we study the general Randić, first Zagreb, ABC, GA, ABC4 and GA5, indices for the first, second, and third types of dominating David derived networks and give closed formulas of these indices for these networks. These results are useful in network science to understand the underlying topologies of these networks.


2021 ◽  
Vol 11 (5) ◽  
pp. 13290-13302

In medical science, pharmacology, chemical, biological, pharmaceutical properties of molecular structure are essential for drug preparation and design. These properties can be studied by using topological indices calculation. In this research work, we establish the topological properties of some chemical structures that have been applied for the treatment of COVID-19 patients by using the domination of topological indices and γ-domination indices. We determine the φ_P- polynomial for the antiviral chemical structures. The results obtained can help study the chemical properties of chemical structures that have been applied for the treatment of COVID-19 patients.


2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.


2011 ◽  
Vol 382 ◽  
pp. 372-374
Author(s):  
Yong Jiang ◽  
Zhi Bin Jiang ◽  
Guo Jie Shao ◽  
Dong Cheng Guo ◽  
Yu Tian ◽  
...  

Purpose: The purpose of this study was to study the compositions of the polygonaceae medicinal plants called rumex root. Methods: Solvent method and chromatography was used to purificate the chemical compositions of Rumex, and the molecular structure of the compound was identified by physical and chemical properties and spectral data. Results: Two compounds were obtained from the ethanol extract of rumex root, which were identified as Chrysophanol and Physcione. Conclusions: Experimental basis was provided for the further study of the active ingredients of rumex root and the development and utilization of medical resources.


1978 ◽  
Vol 31 (3) ◽  
pp. 661 ◽  
Author(s):  
RS Dickson ◽  
SH Johnson

The reaction of [Rh(CO)2Cl]2 with CF3C≡CCF3 gives a fluorocarbon-rhodium complex of approximate formula [RhCl(CO)2 or 3(C4F6)]n,xH2O,yC6H6. The complex is an intermediate in the formation of tetrakis(trifluoromethyl)cyclopentadienone from CF3C≡CCF3 and CO in the presence of[Rh(CO)2Cl]2. The molecular structure of the complex remains obscure despite extensive study of its spectroscopic and chemical properties. The major products formed in the reactions of the complex with σ-cyclopentadienylthallium and with triphenylphosphine are (η- C5H5)2Rh2(CO)2(CF3C2CF3)and Rh(CO)Cl(PPh3)2 respectively.


1976 ◽  
Vol 54 (20) ◽  
pp. 3130-3141 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter

Crystals of B,B-bis(p-tolyl)boroxazolidine, 1c, are trigonal, a = 25.1028(9), c = 12.4184(7) Å, Z = 18, space group [Formula: see text]. And crystals of B,B-diphenylboroxazolidine, 1a, are orthorhombic, a = 17.6420(4), b = 14.2527(3), c = 10.205(1) Å, Z = 8, space group Pbca. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to final R values of 0.057 and 0.040 for 2230 and 1828 reflections with I ≥ 3σ(I) respectively. Both molecules have structures similar to related compounds and feature intermolecular N—H … O hydrogen bonds (N … O = 2.982(2) for 1c and 2.896(2) Å for 1a). Bond lengths are: for 1c; O—C, 1.413(3), O—B, 1.478(3), N—C, 1.488(3), N—B, 1.657(3), C(sp3)—C(sp3), 1.501(4), B—C, 1.616(3) and 1.623(3), mean C—C(ar), 1.395, N—H, 0.93(2) and 0.94(2), mean C(sp3)—H, 1.00, and mean C(ar)—H, 1.00 Å; for 1a; O—C, 1.409(2), O—B, 1.476(2), N—C, 1.489(2), N—B, 1.655(2), C(sp3)—C(sp3), 1.507(3), B—C, 1.613(2) and 1.620(2), mean C—C(ar), 1.391, N—H, 0.93(2) and 0.92(2), mean C(sp3)—H, 1.00, and mean C(ar)—H, 0.98 Å. A statistical analysis of the phenyl C—C distances in compounds 1a, 1b, and 1c has provided an example of statistically significant substituent-induced bond length variation in the phenyl rings.


2018 ◽  
Vol 74 (1-2) ◽  
pp. 25-33 ◽  
Author(s):  
Zahid Iqbal ◽  
Muhammad Ishaq ◽  
Adnan Aslam ◽  
Wei Gao

AbstractPrevious studies show that certain physical and chemical properties of chemical compounds are closely related with their molecular structure. As a theoretical basis, it provides a new way of thinking by analyzing the molecular structure of the compounds to understand their physical and chemical properties. The molecular topological indices are numerical invariants of a molecular graph and are useful to predict their bioactivity. Among these topological indices, the eccentric-connectivity index has a prominent place, because of its high degree of predictability of pharmaceutical properties. In this article, we compute the closed formulae of eccentric-connectivity–based indices and its corresponding polynomial for water-soluble perylenediimides-cored polyglycerol dendrimers. Furthermore, the edge version of eccentric-connectivity index for a new class of dendrimers is determined. The conclusions we obtained in this article illustrate the promising application prospects in the field of bioinformatics and nanomaterial engineering.


Symmetry ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 320 ◽  
Author(s):  
Young Kwun ◽  
Abaid Virk ◽  
Waqas Nazeer ◽  
M. Rehman ◽  
Shin Kang

The application of graph theory in chemical and molecular structure research has far exceeded people’s expectations, and it has recently grown exponentially. In the molecular graph, atoms are represented by vertices and bonds by edges. Topological indices help us to predict many physico-chemical properties of the concerned molecular compound. In this article, we compute Generalized first and multiplicative Zagreb indices, the multiplicative version of the atomic bond connectivity index, and the Generalized multiplicative Geometric Arithmetic index for silicon-carbon Si2C3−I[p,q] and Si2C3−II[p,q] second.


2008 ◽  
Vol 15 (3) ◽  
pp. 389-395 ◽  
Author(s):  
A. Jiménez ◽  
K. F. Tiampo ◽  
A. M. Posadas

Abstract. Recent work has shown that disparate systems can be described as complex networks i.e. assemblies of nodes and links with nontrivial topological properties. Examples include technological, biological and social systems. Among them, earthquakes have been studied from this perspective. In the present work, we divide the Southern California region into cells of 0.1°, and calculate the correlation of activity between them to create functional networks for that seismic area, in the same way that the brain activity is studied from the complex network perspective. We found that the network shows small world features.


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