Ultrafast dynamics in polycyclic aromatic hydrocarbons: the key case of conical intersections at higher excited states and their role in the photophysics of phenanthrene monomer

In this study we reveal the detailed photocycle of a phenanthrene monomer. Phenanthrene serves as a popular building block for supramolecular systems and as an archetypal molecule to study the photochemistry of polycyclic aromatic hydrocarbons. By means of femtosecond time-resolved UV-vis transient absorption spectroscopy and molecular modeling, we found that the first bright transition involves the second excited singlet state, which relaxes...