title: Computational study on the photophysics of protonated benzene.
abstract: The reaction paths in the lowest excited electronic states relevant for the photophysics of protonated benzene, C(6)H(7)(+), have been explored by ab initio techniques of electronic structure theory. For this purpose, the first four excited singlet electronic states of C(6)H(7)(+) have been calculated at the CC2/cc-pVTZ level of theory. The CC2 approach has been validated by CASPT2 and TD-DFT calculations. The calculated UV absorption spectrum is in good agreement with the experimental spectrum. It has been found that the out-of-plane and the in-plane ring deformation leads in the excited states in an essential barrierless manner to a low-lying conical intersection between the lowest excited states and with the ground state, providing a mechanism for efficient radiationless deactivation, which is expected to quench luminescence of the isolated molecular ion.
authors.affiliation: Institute of Physics, Polish Academy of Sciences, PL-02668 Warsaw, Poland.
authors.forename: Michal F
authors.initials: MF
authors.lastname: Rode
authors.forename: Andrzej L
authors.initials: AL
authors.lastname: Sobolewski
authors.forename: Claude
authors.initials: C
authors.lastname: Dedonder
authors.forename: Christophe
authors.initials: C
authors.lastname: Jouvet
authors.forename: Otto
authors.initials: O
authors.lastname: Dopfer