Generation and Enumeration of Single Coronoid Isomers

Abstract

The present chapter deals with the numbers of C_nH_s single coronoid isomers (cardinalities of genus 1 of the C_nH_s formulas, | C_nH_s |₁ cf. Sect. 3.8). Complete data of such isomers are known for 8 ≤ h ≤ 14. This is to understand that the | C_nH_s |₁ values are known for all C_nH_s formulas which are compatible with the given h values. These numbers of isomers, classified according to the Kekuléan and non-Kekuléan systems, have been given for 8 ≤ h < 11 by Cyvin SJ and Brunvoll (1989), and for 12 ≤ h ≤ 14 by Cyvin SJ, Brunvoll and Cyvin (1991a). They are summarized in Table 1. The last reference (Cyvin SJ, Brunvoll and Cyvin 1991a) contains also |C₅₀H₂₀|₁ = 51, |C₅₂H₂₀|₁ = 12 and |C₅₄H₂₀|₁ = 2, but these numbers represent incomplete data for h = 15, 16 and 17, respectively.