antioxidants are made for the struggle and reconstruction of the damaged cells, because of their ability in destroying the free radicals. on account of their importance, a theoretical procedure was applied for the study of the molecular structure and radical scavenging activity of six hydroxyphenols which have been introduced as antioxidant compounds. all geometry structures were optimized by m...

thirty nine novel 1,2,3,4-tetrahydropyrimidinone (thione)s were subjected to conformational studies. density functional theory at b3lyp/6-31 g* was performed as the computational method of high accuracy. important dihedral angles and bond lengths were investigated and the values obtained were explainable. results of this work confirm a twisted boat tetrahydropyrimidine ring conformation with an...

let $gamma_{n,kappa}$ be the class of all graphs with $ngeq3$ vertices and $kappageq2$ vertex connectivity. denote by $upsilon_{n,beta}$ the family of all connected graphs with $ngeq4$ vertices and matching number $beta$ where $2leqbetaleqlfloorfrac{n}{2}rfloor$. in the classes of graphs $gamma_{n,kappa}$ and $upsilon_{n,beta}$, the elements having maximum augmented zagreb index are determined.

In theoretical chemistry, -modified Wiener index is a graph invariant topological index to analyze the chemical properties of molecular structure. In this note, we determine the minimum -modified Wiener index of graph with fixed connectivity or edge-connectivity. Our results also present the sufficient and necessary condition for reaching the lower bound.

The imidazopyridine fused ring in the title compound, C(20)H(16)BrN(3)O·H(2)O, is coplanar with the aromatic ring at the 2-position [dihedral angle = 5.2 (1)°]. In the five-membered imidazo portion, the C-N bond whose C atom is also connected to the pyridine N atom has predominantly double-bond character [1.334 (2) Å] whereas the C-N bond whose atom is connected to the pyridine C atom has predo...

let g be a connected simple (molecular) graph. the distance d(u, v) between two vertices u and v of g is equal to the length of a shortest path that connects u and v. in this paper we compute some distance based topological indices of h-phenylenic nanotorus. at first we obtain an exactformula for the wiener index. as application we calculate the schultz index and modified schultz index of this ...

A topological descriptor is regarded as a numerical parameter derived by using mathematical tools from the molecular graph of different chemical structures. The theory paramount section chemistry. In this section, there are many parameters, that have very useful characteristics to study structure chemicals. article, we investigate indices concealed non-kekulean benzenoid hydrocarbon graph. We w...

Graph signal processing deals with signals whose domain, defined by a graph, is irregular. The total π-electron energy or simply the π-electronic energy, as calculated within Hückel tight-binding molecular orbital approximation, one of important quantum-theoretical characteristic conjugated molecules. In this paper, we propose an efficient computer-assisted computational method to determine eig...

the eccentricity connectivity index of a molecular graph g is defined as (g) = av(g)deg(a)ε(a), where ε(a) is defined as the length of a maximal path connecting a to othervertices of g and deg(a) is degree of vertex a. here, we compute this topological index forsome infinite classes of dendrimer graphs.