BOND ORDERING RELATION - INCOMPATIBILITY BETWEEN BONDS, ESSENTIAL SINGLE/DOUBLE BONDS, AND THE NONEXISTENCE OF KEKULE STRUCTURES IN MOLECULAR SUBGRAPHS

摘要

An ordering relation between single and/or double bonds, such that one bond gives an order to another, on a set of Kekule structures (perfect matchings) in hydrogen-suppressed molecular graphs is defined. By use of this binary relation, lemmas relating to both incompatibility between bonds and essential single/double bonds can be described. It is thus possible to estimate the nonexistence of Kekule structures in a given molecular subgraph. [References: 7]