title: Excited States of Xanthene Analogues: Photofragmentation and Calculations by CC2 and Time-Dependent Density Functional Theory.
abstract: Action spectroscopy has emerged as an analytical tool to probe excited states in the gas phase. Although comparison of gas-phase absorption properties with quantum-chemical calculations is, in principle, straightforward, popular methods often fail to describe many molecules of interest-such as xanthene analogues. We, therefore, face their nano- and picosecond laser-induced photofragmentation with excited-state computations by using the CC2 method and time-dependent density functional theory (TDDFT). Whereas the extracted absorption maxima agree with CC2 predictions, the TDDFT excitation energies are blueshifted. Lowering the amount of Hartree-Fock exchange in the DFT functional can reduce this shift but at the cost of changing the nature of the excited state. Additional bandwidth observed in the photofragmentation spectra is rationalized in terms of multiphoton processes. Observed fragmentation from higher-lying excited states conforms to intense excited-to-excited state transitions calculated with CC2. The CC2 method is thus suitable for the comparison with photofragmentation in xanthene analogues.
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France. mail@alexanderkulesza.de.
authors.forename: Alexander Jan
authors.identifier: http://orcid.org/0000-0002-8812-8548
authors.initials: AJ
authors.lastname: Kulesza
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, Haus 25, D-14476, Potsdam, Germany.
authors.forename: Evgenii
authors.identifier: http://orcid.org/0000-0002-1732-1826
authors.initials: E
authors.lastname: Titov
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France.
authors.forename: Steven
authors.initials: S
authors.lastname: Daly
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, Haus 25, D-14476, Potsdam, Germany.
authors.forename: Radosław
authors.initials: R
authors.lastname: Włodarczyk
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, Haus 25, D-14476, Potsdam, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Megow
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, Haus 25, D-14476, Potsdam, Germany.
authors.forename: Peter
authors.identifier: http://orcid.org/0000-0002-5988-5945
authors.initials: P
authors.lastname: Saalfrank
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France.
authors.forename: Chang Min
authors.identifier: http://orcid.org/0000-0001-7708-9056
authors.initials: CM
authors.lastname: Choi
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France.
authors.forename: Luke
authors.identifier: http://orcid.org/0000-0001-8821-6049
authors.initials: L
authors.lastname: MacAleese
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Antoine
authors.affiliation: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Lyon, France.
authors.forename: Philippe
authors.identifier: http://orcid.org/0000-0003-4395-1140
authors.initials: P
authors.lastname: Dugourd
keywords: CC2 calculations; density functional calculations; multiphoton processes; photofragmentation; xanthenes