ENUMERATION OF CHEMICAL ISOMERS OF POLYCYCLIC CONJUGATED HYDROCARBONS WITH DIFFERENT RING SIZES

Polygonal systems, corresponding to completely condensed polycyclic conjugated hydrocarbons with arbitrary ring sizes, are studied. For all the cases up to four rings inclusive, the numbers of CnHs isomers are reported, as well as for some classes of the systems with five rings. Explicit combinatorial expressions and the solutions in terms of generating functions are given in some cases. These solutions were corroborated and extended by computer programming. Chemical applications are reported with references to hydrocarbons which are known in organic chemistry.