Chemical stereographs: An extension of chemical graphs for representing stereochemical and conformational structures

Chemical stereographs are presented as vehicles for representing qualitative three-dimensional features of molecules that put stereochemical and conformational distinctions in a common graph-theoretic formalism. They extend the concept of a chemical graph by adding tetrads, each qualitatively characterizing the three-dimensional arrangement of four atoms with respect to its clinicity and handedness components. The characterization is sufficiently precise to distinguish synperiplanar, synclinical (gauche), anticlinal and antiperiplanar relationships between vicinal atoms of various conformers. Collectively, the tetrads constitute the embedding graph which presents new possibilities in displaying the stereochemical and conformational features of a molecule. A chemical graph and one of its possible embedding graphs constitute a chemical stereograph. Potential applications of chemical stereographs in the areas of structural representations, molecular symmetry analysis, and stereo-specific substructure searching are discussed.Part of this work was presented by M.J. at the 1989 PaciChem Mathematical Chemistry Minisymposium. The work was funded by The Upjohn Company.