TOPOLOGICAL PROPERTIES OF CIRCUMCORONENES

The regular-hexagon-shaped benzenoid hydrocarbons: B-1=benzene (C6H6), B-2=coronene (C24H12), B-3 = circumcoronene (C54H18), B-4 = circumcir cumcoronene (C150H30), etc. possess unique topological properties. Gen eral expressions for the most important of such properties (number of fundamental structural invariants, number of Kekule and Clar structure s, number of aromatic sextets, Wiener and Szeged indices, spectral mom ents) are given, including a number of results that are communicated h ere for the first time. Cyclic conjugation In circumcoronenes is analy zed by means of its energy-effect, and found to agree with the predict ions of Clar's aromatic sextet theory only in the case of B-1 and B-2.