The expected values of Sombor indices in random hexagonal chains, phenylene chains and Sombor indices of some chemical graphs

Hexagonal chains are a special class of catacondensed benzenoid system and phenylene chains are a class of polycyclic aromatic compounds. Recently, A family of Sombor indices was introduced by Gutman in the chemical graph theory. It had been examined that these indices may be successfully applied on modeling thermodynamic properties of compounds. In this paper, we study the expected values of the Sombor indices in random hexagonal chains, phenylene chains, and consider the Sombor indices of some chemical graphs such as graphene, coronoid systems and carbon nanocones.

Analysis of irregularity measures of zigzag, rhombic, and honeycomb benzenoid systems

Molecular topology is a key to determine the physiochemical aspects of the molecular structure. To determine the degree of irregularity of a certain molecular structure or a network has been a key source of interest for the molecular topologists as it provides an insight of the key features that are used to guess the properties of the structures. In this article, we are interested in formulating closed forms of irregularity measures of some popular benzenoid systems, namely, zigzag, rhombic, and honeycomb benzenoid systems. We also compared our results graphically and concluded that benzenoid system among above is more asymmetric than the others.

Irregularity Molecular Descriptors of Hourglass, Jagged-Rectangle, and Triangular Benzenoid Systems

Determining the degree of irregularity of a certain molecular structure or a network has been a key source of interest for molecular topologists, but it is also important as it provides an insight into the key features used to guess properties of the structures. In this article, we are interested in formulating closed forms of irregularity measures of some popular benzenoid systems, such as hourglass H (m, n), jagged-rectangular J (m, n), and triangular benzenoid T (m, n) systems. We also compared our results graphically and concluded which benzenoid system among the above listed is more irregular than the others.

A method for computing the edge-hyper-Wiener index of partial cubes and an algorithm for benzenoid systems

The edge-hyper-Wiener index of a connected graph G is defined as WWe(G)=1/2 ?{e,f}?E(G) d(e,f) + 1/2 ? {e,f}?E(G)d(e,f)2. We develop a method for computing the edge-hyper-Wiener index of partial cubes, which constitute a large class of graphs with a lot of applications. It is also shown how the method can be applied to trees. Furthermore, an algorithm for computing the edge-hyper-Wiener index of benzenoid systems is obtained. Moreover, the algorithm is used to recalculate already known closed formulas for the edge-Wiener index and the edge-hyper-Wiener index of linear polyacenes. Finally, the method is presented on a benzenoid system with more complicated structure.

On benzenoid systems with minimal number of inlets

Inlets are features on the perimeter of a benzenoid system that determine numerous of its electronic and topological properties. A class of large benzenoid systems is constructed, having small number of inlets. It is shown that the minimal number of inlets in a benzenoid system with h hexagons is less than or equal to ?3(h-1).

A new and facile synthetic approach to substituted 2-thioxoquinazolin-4-ones by the annulation of a pyrimidine derivative

A new and facile synthesis of 2-thioxoquinazolin-4-ones by introducing a benzenoid system in the pyrimidine moiety by reacting ethoxymethylene derivatives of 1,3-diarylthiobarbituric acids (DTBA) with active methylene compounds, such as malononitrile and ethyl cyanoacetate, in presence of ZnCl2 has been developed.