Advances in the Theory of Benzenoid Hydrocarbons

Benzenoid hydrocarbons in space: The evidence and implications.- The distortive tendencies of delocalized ? electronic systems. Benzene, cyclobutadiene and related heteroannulenes.- The spin-coupled valence bond description of benzenoid aromatic molecules.- Semiempirical valence bond views for benzenoid hydrocarbons.- Scaling properties of topological invariants.- Molecular topology and chemical reactivity of polynuclear benzenoid hydrocarbons.- A periodic table for benzenoid hydrocarbons.- Calculating the numbers of perfect matchings and of spanning trees, Pauling's orders, the characteristic polynomial, and the eigenvectors of a benzenoid system.- The existence of Kekulé structures in a benzenoid system.- Peak-valley path method on benzenoid and coronoid systems.- Rapid ways to recognize Kekuléan benzenoid systems.- Methods of enumerating Kekulé structures, exemplified by applications to rectangle-shaped benzenoids.- Clar's aromatic sextet and sextet polynomial.- Caterpillar (Gutman) trees in chemical graph theory.