Molecular Structural Descriptors of Donut Benzenoid Systems

Abstract

Circumcised donut benzenoid systems are a class of polycyclic aromatic hydrocarbons (PAHs) derived from planar benzenoid networks by strategically eliminating a few hexagons. The study of donut benzenoid systems has been gaining ground because of their neoteric and fascinating characteristics like superaromaticity, ascribed to their unique structure. The distinct nature and properties of donut benzenoids open the door for applications in several industries such as biotechnology, electronics, pharmaceuticals and so on. The investigation of the properties of circumcised donut benzenoids and their relationship to the underlying molecular structures using graph-theoretical techniques is advantageous in the design and synthesis of new donut benzenoid compounds. Studies on topological indices have conclusively proved that they have a strong correlation to various properties of chemical compounds. They also provide a mathematical representation of the molecular structure for QSPR/QSAR techniques. In this paper, the degree-based molecular structural descriptors are calculated for two circumcised donut benzenoid structures using M-polynomial and edge partition techniques, effectively doubling the number of known topological indices for these structures. Also, the numerical values of these indices are computed and compared pictorially.