title: Wavelength and solvent independent photochemistry: the electrocyclic ring-closure of indolylfulgides.
abstract: A wavelength and solvent dependent study of a photochromic indolylfulgide is presented. The ring-closure reaction is characterized using stationary and time-resolved spectroscopy with femtosecond time resolution. After excitation into the first excited singlet state (S(1)) the photoprocesses proceed on ultrafast timescales (0.3-0.45 ps) in both polar and non-polar solvents. Excitation into higher electronic states results in similar reaction kinetics as found for S(1) excitation. A simple kinetic scheme can be established for the photoprocesses under all different experimental conditions: as expected from organic textbooks neither the solvent surroundings nor the excitation wavelength strongly alter the reaction scheme. The experimental study demonstrates that the ring-closure reaction of photochromic indolylfulgides can be considered as a very robust photoprocess: this fact may lead to a great variety of different applications where the reaction dynamics of the molecular switch are not disturbed by any surrounding effects.
authors.affiliation: Ludwig-Maximilians-Universität München, Oettigenstr. 67, D-80538, München, Germany.
authors.forename: Thorben
authors.initials: T
authors.lastname: Cordes
authors.forename: Teja T
authors.initials: TT
authors.lastname: Herzog
authors.forename: Stephan
authors.initials: S
authors.lastname: Malkmus
authors.forename: Simone
authors.initials: S
authors.lastname: Draxler
authors.forename: Thomas
authors.initials: T
authors.lastname: Brust
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Digirolamo
authors.forename: Watson J
authors.initials: WJ
authors.lastname: Lees
authors.forename: Markus
authors.initials: M
authors.lastname: Braun