Extremal values of vertex‐degree‐based topological indices of coronoid systems. Issue 6 (10th November 2020)

• Record Type: Journal Article
• Authors: Cruz, Roberto; Santamaría‐Galvis, Andrés David; Rada, Juan
• Is Part Of: International journal of quantum chemistry. Volume 121:Issue 6(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-10
• Subjects: coronoid systems -- vertex‐degree‐based topological indices; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.26536
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: A vertex‐degree‐based (VDB for short) topological index φ induced by the numbers { φ i, j }, is defined for a graph G with n vertices as 1 φ G = ∑ 1 ≤ i ≤ j ≤ n − 1 m i, j φ i, j, where m i, j is the number of edges in G joining vertices of degree i and j . Our main concern is to study VDB topological indices over important classes of coronoid systems. Recall that a coronoid system is a natural representation of a coronoid hydrocarbon and can be defined as a benzenoid‐like system with a hole. In this paper we determine the extremal values of a VDB topological index φ over the set of primitive coronoid systems, the set of catacondensed coronoid systems, and the set of circumscribed coronoid systems. Abstract : One important problem in chemical graph theory is to determine extremal values of a vertex‐degree‐based topological index over significant sets of coronoid systems. If we fixed the number of hexagons h, the hollow hexagons, depicted in this figure, are extremal coronoid systems with respect to any vertex‐degree‐based topological index over the classes of primitive coronoid systems, catacondensed coronoid systems and circumscribed coronoid systems with h hexagons.