ABSTRACT
O. Ivanciuc and A.T. Balaban University “Politehnica” of Bucharest, Department of Organic Chemistry,
Faculty of Industrial Chemistry, Oficiul 12 CP 243, 78100 Bucharest, Romania
Usually, the chemical structure of organic compounds is represented by molecular graphs. Graph algorithms are currently used in isomer generation, coding of chemical compounds and reactions, chemical database search, similarity and diversity assessment. An important graph theory application is the numerical characterization of chemical structures with graph invariants, that can be polynomials, spectra, atomic or molecular topological indices. After a brief presentation of graph theory and chemical graphs, the molecular graphs are defined. The most important molecular graph matrices, polynomials, and spectra are introduced, and some examples are presented. A large variety of mathematical operations are applied to molecular graphs giving atomic and molecular structural descriptors; the most important topological indices are reviewed, and their applications in structure-property models are briefly presented.
