scholarly journals Schultz and Modified Schultz Polynomials of Coronene Polycyclic Aromatic Hydrocarbons

Author(s):  
Mohammad Reza Farahani

Let G = (V;E) be a simple connected graph. The sets of vertices and edges of G are denoted byV = V(G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms andedges represent bonds. The distance between the vertices u and v in V(G) of graph G is the number ofedges in a shortest path connecting them, we denote by d(u,v). In graph theory, we have manyinvariant polynomials for a graph G. In this research, we computing the Schultz polynomial, ModifiedSchultz polynomial, Hosoya polynomial and their topological indices of a Hydrocarbon molecule, thatwe call “Coronene Polycyclic Aromatic Hydrocarbons”.

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Haiying Wang ◽  
Chuantao Li

The general (α,t)-path connectivity index of a molecular graph originates from many practical problems such as three-dimensional quantitative structure-activity (3D QSAR) and molecular chirality. It is defined as Rtα(G)=∑Pt=vi1vi2⋯vit+1⊆G[d(vi1)d(vi2)⋯d(vit+1)]α, where the summation is taken over all possible paths of length t of G and we do not distinguish between the paths vi1vi2⋯vit+1 and vit+1⋯vi2vi1. In this paper, we focus on the structures of Polycyclic Aromatic Hydrocarbons (PAHn), which play a role in organic materials and medical sciences. We try to compute the exact general (α,3)-path connectivity indices of this family of hydrocarbon structures. Furthermore, we exactly derive the monotonicity and the extremal values of R3α(PAHn) for any real number α. These valuable results could produce strong guiding significance to these applied sciences.


2021 ◽  
Vol 18 ◽  
Author(s):  
Muhammad Javaid ◽  
Muhammad Ibraheem ◽  
Abdul Raheem

Introduction: A graph is supposed to be regular if all vertices have equal degree, otherwise irregular. Materials and Methods: Polycyclic aromatic hydrocarbons are important combusting material and considered as class of carcinogens. These polycyclic aromatic hydrocarbons play an important role in graphitisation of medical science. A topological index is a function that assigns a numerical value to a (molecular) graph which predicts various physical, chemical, biological, thermodynamical and structural properties of (molecular) graphs. An irregular index is a topological index that measures the irregularity of atoms with respect to their bonding for the chemical compounds which are involved in the under studying graphs. Results and Discussion: In this paper, we will compute an analysis of distance based irregular indices of polycyclic aromatic hydrocarbons. A comparison among the obtained indices with the help of their numerical values and the 3D presentations is also included. The efficient and steady indices of polycyclic aromatic hydrocarbons are addressed in the form of their irregularities. Conclusion: Connection based study of the molecular graphs is more suitable than the degree based irregularity indices.


Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 467
Author(s):  
Andrey A. Dobrynin ◽  
Ali Iranmanesh

The Wiener index is a topological index of a molecular graph, defined as the sum of distances between all pairs of its vertices. Benzenoid graphs include molecular graphs of polycyclic aromatic hydrocarbons. An edge thorny graph G is constructed from a catacondensed benzenoid graph H by attaching new graphs to edges of a perfect matching of H. A formula for the Wiener index of G is derived. The index of the resulting graph does not contain distance characteristics of elements of H and depends on the Wiener index of H and distance properties of the attached graphs.


Symmetry ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 426
Author(s):  
Haiying Wang

The general ( α , t ) -path sum-connectivity index of a molecular graph originates from many practical problems, such as the three-dimensional quantitative structure–activity relationships (3D QSAR) and molecular chirality. For arbitrary nonzero real number α and arbitrary positive integer t, it is defined as t χ α ( G ) = ∑ P t = v i 1 v i 2 ⋯ v i t + 1 ⊆ G [ d G ( v i 1 ) d G ( v i 2 ) ⋯ d G ( v i t + 1 ) ] α , where we take the sum over all possible paths of length t of G and two paths v i 1 v i 2 ⋯ v i t + 1 and v i t + 1 ⋯ v i 2 v i 1 are considered to be one path. In this work, one important class of polycyclic aromatic hydrocarbons and their structures are firstly considered, which play a role in organic materials and medical sciences. We try to compute the exact general ( α , 2 ) -path sum-connectivity indices of these hydrocarbon systems. Furthermore, we exactly derive the monotonicity and the extremal values of these polycyclic aromatic hydrocarbons for any real number α . These valuable results could produce strong guiding significance to these applied sciences.


2015 ◽  
Vol 12 (1) ◽  
pp. 3934-3939 ◽  
Author(s):  
Wei Gao ◽  
MOHAMMAD REZA FARAHANI

The omega polynomial Ω(G,x), for counting qoc strips in molecular graph G was defined by Diudea as  with m(G,c), being the number of qoc strips of length c. The Theta polynomial Θ(G,x) and the Theta index Θ(G) of a molecular graph G were defined as Θ(G,x)= and Θ(G)=, respectively.In this paper, we compute the Theta polynomial Θ(G,x) and the Theta index Θ(G) of molecular graph Polycyclic Aromatic Hydrocarbons PAHk, for all positive integer number k. 


2019 ◽  
Vol 64 (1) ◽  
pp. 55-67
Author(s):  
Vlad Pӑnescu ◽  
◽  
Mihaela Cӑtӑlina Herghelegiu ◽  
Sorin Pop ◽  
Mircea Anton ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document