Topological Indices Derived From Parts of a Universal Matrix

Anton Perdih*, Franc Perdih

Department of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia.

Using the approach of mutual contribution of vertices to the value of topological indices derived from parts of a universal matrix gave the idea how to develop new topological indices. Some of the newly developed indices are useful indices of Octane Numbers and of Critical Pressure of alkanes of equal carbon number, giving rise to abs(Rfit) > 0.99. Using them we estimated the missing data of Octane Numbers of 2,3-dimethyl butane and 2,2,3,3-tetramethyl butane, as well as of nonanes and decanes. The best analogous indices derived from the reverse variants of this universal matrix are in general less useful. Some types of newly developed indices are also useful for structural interpretation of several known indices.

Key words: alkane, index, octane number, structural interpretation, topological matrix