Classification According to the Corona Holes

The pair of invariants (ho, n ) pertain to the corona hole (considered as a benzenoid) of a single coronoid C, while (h, n are the corresponding invariants of C. For a given h value, the range of h values was found to be — Vol. I-eqn. (9.8) 

Dias JR (1982). J Chem Inf Comput Sci 22 15 wrong numbers therein are omitted. 

Bowever, aU benzenoids with the hP values prescribed above need not be inspected (for h 8). Take for instance h = 12, for which the maximum value is 7 in accordance with eqn. (1). Here only one out of the 331 benzenoids with seven hexagons is of interest, viz. coronene. The corresponding corona hole h = 7, = 6) occurs in kekulene h = 12), whUe all single 

In order to shed some Ught on the above problem, introduce 

according to the last equation in Volume I, I—(9.9), a primitive single coronoid around the hole (ho, nfl) has h = h (and = 0). This of course presupposes that the corona hole benzenoid, which is characterized by (h , can be circumscribed. The foUowing restrictions are vaUd for primitive single coronoids. 

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