ABSTRACT
A.T. Balaban and O. Ivanciuc Department of Organic Chemistry, Faculty of Chemical Technology,
University “Politehnica” of Bucharest, Oficiul 12 CP 243, 78100 Bucharest, Romania
Beginning with Wiener, numerical molecular descriptors, named topological indices (TIs) by Hosoya, have gained gradual acceptance along with other descriptors for use in QSAR and QSPR studies. The historical development will follow the chronological order but also the classification into first-, second-, and third-generation TIs, according to the nature of the local and global descriptor: integer or real number. The latest developments involve stereochemical descriptors. The historical description will also provide some information on how high is the degeneracy of the TIs, and how their correlation ability allows them to be used in single-or multiple-parameter correlations, which in turn may be linear or non linear. Intercorrelations between various TIs make some of them redundant. Appreciations on the usefulness and potential of TIs will be described. The bibliography will encompass more than 40 years of the history of TIs.
