Structure and Electronic Characteristics of Coronoid Polycyclic Aromatic Hydrocarbons as Potential Models of Graphite Layers with Hole Defects

While the literature on coronoid hydrocarbons is comprehensively surveyed, new enumeration results on select coronoid classes are presented. The first examples of Kekulean polycyclic (even-carbon) alternant hydrocarbons with doubly degenerate zero eigenvalues at the HMO level are identified. The parallelism between a molecule removed and the antimolecule hole left in formation of a graphite vacancy defect is elaborated. It is argued that the formation of a single carbon atom vacancy hole defect in graphite should be facile because it would entail a minimum electronic reorganization. These results are supported by a substantial amount of eigenvalue calculations. This work provides a unique overview for the class of coronoid hydrocarbons.