The Most Stable Class of Benzenoid Hydrocarbons and Their Topological Characteristics − Total Resonant Sextet Benzenoids Revisited

Polycyclic aromatic hydrocarbons that we previously called total resonant sextet (TRS) benzenoids are revisited within the framework of recent experimental findings. A benzenoid transformation called leapfrogging generates TRS benzenoids. There are 13, 30, and 114 TRS benzenoid isomers with formulas C 72 H 26, C 96 H 30, and C 102 H 32, respectively. “The leapfrogs of benzenoids are 2-factorable” is a stronger statement than “the leapfrogs of benzenoids are closed-shell.”