Assignment of the vibrations of the S0, S1, and D0+ states of perhydrogenated and perdeuterated isotopologues of chlorobenzene

We report vibrationally resolved spectra of the S-1 <- S-0 transition of chlorobenzene using resonance-enhanced multiphoton ionization spectroscopy. We study chlorobenzene-h(5) as well as its perdeuterated isotopologue, chlorobenzene-d5. Changes in the form of the vibrational modes between the isotopologues and also between the S-0 and S-1 electronic states are discussed for each species. Vibrational bands are assigned utilizing quantum chemical calculations, previous experimental results, and isotopic shifts, including those between the Cl-35 and Cl-37 isotopologues. Previous work and assignments of the S-1 spectra are discussed. Additionally, the vibrations in the ground state cation, D-0(+), are considered, since these have also been used by previous workers in assigning the excited neutral state spectra. (C) 2015 AIP Publishing LLC.