ORDERING THE ISOMERIC MOLECULES THROUGH THE GRAPH SPECTRUM - GENERATION OF 2 TOPOLOGICAL INDEXES DEPICTING THE BRANCH AND LINEAR CHARACTERS(A COMPUTATIONAL METHOD)

Octane isomeric molecules have been ordered by using the graph spectru m of the vertex adjacency matrix and a Fortran-77 program. The program not only orders the isomeric molecules into various subgroups, but al so generates topological descriptors, which primarily depict the branc hing and linear characters of the molecule. These descriptors are corr elated with different physical properties, like standard entropy (S(29 8)degrees) Standard entropy of formation (Delta S(298)degrees), heat o f vaporization (H-v), octane number (MON), and A coefficient of Antoin e equation. Good correlations of the descriptors with the above proper ties have been obtained.