Application of Reduced Graph Model to the Enumeration of Kekule Structures and Conjugated Circuits of Benzenoid Hydrocarbons

The reduced graph model which represents an alternative way of depicting hexagonal networks is reviewed. This model is exploited in several enumeration problems of benzenoid systems. It is used as a basis for »pencil and paper« algorithms for counting Kekule structures, conjugated circuits and cata-condensed isomers of benzenoid hydrocarbons

On Normalization of Topological Resonance Energy

Normalization of the topological resonance energy, TRE, with respect to the total number of pi-electrons, TRE(PE), and with respect to the number of ring bonds in a molecule, TRE(PRB), was done. That both indices, TRE(PE) and TRE(PRB), lead to similar predictions concerning stability and aromatic behavior of conjugated species was shown by a comparative analysis of various classes of compounds