title: Visible and ultraviolet spectroscopy of gas phase rhodamine 575 cations.
abstract: The visible and ultraviolet spectroscopy of gas phase rhodamine 575 cations has been studied experimentally by action-spectroscopy in a modified linear ion trap between 220 and 590 nm and by time-dependent density functional theory (TDDFT) calculations. Three bands are observed that can be assigned to the electronic transitions S0 → S1, S0 → S3, and S0 → (S8,S9) according to the theoretical prediction. While the agreement between theory and experiment is excellent for the S3 and S8/S9 transitions, a large shift in the value of the calculated S1 transition energy is observed. A theoretical analysis of thermochromism, potential vibronic effects, and-qualitatively-electron correlation revealed it is mainly the latter that is responsible for the failure of TDDFT to accurately reproduce the S1 transition energy, and that a significant thermochromic shift is also present. Finally, we investigated the nature of the excited states by analyzing the excitations and discussed their different fragmentation behavior. We hypothesize that different contributions of local versus charge transfer excitations are responsible for 1-photon versus 2-photon fragmentation observed experimentally.
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Steven
authors.initials: S
authors.lastname: Daly
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kulesza
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Knight
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Luke
authors.initials: L
authors.lastname: MacAleese
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Antoine
authors.affiliation: †Université de Lyon, F-69622, Lyon, France.|‡CNRS et Université Lyon 1, UMR5306, Institut Lumière Matière, 69622, Villeurbanne CEDEX, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Dugourd