On the Shape of C6H6

摘要: The benzene molecule serves as a benchmark among the aromatic hydrocarbons and has been subject of numerous experimental theoretical studies. Despite such intensive investigations, precise structure cation (C 6 H + ) is not known. Now, experiments measuring high-resolution state-to-state threshold photoionization spectra concretely establish terms vibronic levels in distorted that are split by higher order Jahn-Teller coupling between its 2 E 1g electronic ground state ν e 2g in-plane ring-bending vibrational mode. This assignment, turn, sets absolute energy phase pseudorotation this coordinate thereby offers definitive determination shape cation.