Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Application of Chemical Graph Theory to QSPR

Chemical graph theory is based on the observation that the connectivity of a molecule is correlated to many of its intrinsic physical properties. Chemical graph theory has been successful in providing an estimate of the intrinsic properties of various low-molecular-weight compounds when employed together with a regression analysis.  [Pg.215]

More recently Bicerano has presented a new methodology in which many physical properties are expressed in terms of connectivity indexes This method allows the prediction of properties for a large number of polymers. Instead of group contributions the methodology relies on summation of additive contributions over atoms and bonds. [Pg.215]

Connectivity indexes in particular may be used easily because each index can be calculated from valence bond diagrams. These indexes can also be correlated [Pg.215]

Two basic quantities are tire atomic simple connectivity index 8 and the atomic valence connectivity index 5. These values are tabulated in Bicerano s book (p. 17) for 11 chemical elements, namely C, N, O, F, Si, P, S, Se, Cl, Br, tnd I. Values of 8 and S are also reported for various hybridizations (sp, sp, etc.). 8 is equal to the number of nonhydrogen atoms to which a given atom is bonded. 8 is calculated through  [Pg.216]

Four types of indexes can be identified path-labeled, cluster-labeled, path/ cluster, and chain-labeled, denoted., respectively, by Xp, Xc- Xp/cj and ich- All calculations reported here are based on the zeroth- and first-order connectivity indexes, Xj x and x, x respectively, for the entire repeat unit and these are defined as  [Pg.216]


See other pages where Application of Chemical Graph Theory to QSPR is mentioned: [Pg.215]    [Pg.215]   


SEARCH



Applications of Theory

Applications theory

Chemical graph theory

Chemical graphs

Graph theory

Graph theory applications

QSPR

© 2024 chempedia.info