We further examine the excited state energies of these two compounds with S1-T1 inversions at their excited state minima (S1, T1, T2 and T3, see Figures ). In both compounds, the Hund's rule violation is preserved across all excited state minima considered. In particular, the Hund's rule violation persists in the S1 and T1 states at both the S1 and T1 minima, i.e., the inversion is still at S1-T1. It is therefore possible that the singlet-triplet inversion can help optimize the photophysical properties in this class of molecules. . a = Synthesis reported by Bergmann and Agranat Triafulvene and pentafulvene consist of a three-and five-membered ring, respectively, and an exocyclic double bond (Figure ).