Affiliations: Dipartimento di Chimica, Università della Calabria, Via P. Bucci – cubo 14/C, I-87036 Arcavacata di Rende (CS), Italia. Fax: +39 0984 492044; E-mail: lionp@unical.it
Abstract: A new algorithm which explicitly describes the depleted hydrogen atoms is proposed for chemical graph computations, and especially for molecular connectivity model studies. The new algorithm continues to be centred on the concepts of complete graphs and general graphs, but considers the contribution of the bonded hydrogen atoms as a kind of perturbation, which does not need any new graph concept for its formulation. The model quality of the new algorithm is tested and compared with properties, which have already been modelled without the hydrogen perturbation. Chosen classes of compounds display quite different percentages of bonded hydrogen atoms, allowing thus a checking of the contribution of the hydrogen perturbation as a function of the hydrogen content. Obtained results underline the importance of the property, and, in a minor way, the importance of the number of data points, i.e., the number of compounds, in determining the importance of the hydrogen perturbation. Molecular connectivity terms do not always show the same behaviour as the combination of basis indices relatively to the perturbation introduced by the hydrogen atoms.
Keywords: General chemical graphs, complete graphs, hydrogen perturbation, molecular connectivity computations
