Configurations of Molecules of Benzenoid Substances

On the Szeged Index of Unbranched Catacondensed Benzenoid Molecules

Relation between Wiener–type topological indices of benzenoid molecules

The distance d(u, v|G) between the vertices u and v of a molecular graph G is the length of a shortest u, v-path. We consider a class of Wiener–type topological indices Wλ(G) , defined as the sum of the terms d(u, v|G) λ over all pairs of vertices of G . Several special cases of Wλ(G) , namely for λ = +1 (the original Wiener number) as well as for λ = −2,−1,+1/2,+2 and +3 , were previously stud...

Comparing momenta and pi-electron energy of benzenoid molecules

LetGbe agraph associatedwith the hexagonal systemof a benzenoidhydrocarbon.Let 1 · · · n be the set of eigenvalues of the adjacency matrix ofG and consider the momentaMk= ∑n i=1 ki for k even.We show the lower boundM2 q (MrMs) −1/2 E (G) for the total -electron energy ofG, where q, r, s are even integers with 4q = r + s + 2. Particular cases of this bound improve the well-known McClelland’s ine...

On the tutte polynomial of benzenoid chains

The Tutte polynomial of a graph G, T(G, x,y) is a polynomial in two variables defined for every undirected graph contains information about how the graph is connected. In this paper a simple formula for computing Tutte polynomial of a benzenoid chain is presented.

Dependence of Dewar resonance energy of benzenoid molecules on Kekulé structure count

The dependence of the Dewar resonance energy (DRE) on the Kekulé structure count (K) was found to be significantly different from that earlier anticipated. Within classes of benzenoid isomers, the DRE increases either as K for 0.3 or as (ln K) for 2. Both functional dependencies result in approximate expressions for DRE of nearly equal accuracy. Approximations of the form DRE a K + b and DRE a'...