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MO: Fachverband Molekülphysik
MO 12: Femtosecond Spectroscopy III
MO 12.3: Talk
Tuesday, March 13, 2012, 14:45–15:00, V38.03
ESIPT in 3-Hydroxyflavone and 3-Hydroxychromone: A Femtosecond Transient Absorption Study — •Katharina Chevalier1, Matthias M.N. Wolf1, Andreas Funk3, Markus Gerhards2 und Rolf Diller1 — 1Dept. of Physics, Univ. Kaiserslautern — 2Dept. of Chemistry, Univ. Kaiserslautern, 67663 Kaiserslautern, Germany — 3Institute for Buildings and Materials Chemistry, Univ. Siegen, 57076 Siegen, Germany
3-Hydroxyflavone (3HF) and its derivatives have recently gained interest as fluorescent probes in micelles, liposomes and membranes. Since the respective time constant of proton transfer after electronic excitation (ESIPT) with UV light as well as the characteristics of the fluorescence and transient absorption depend strongly on the polarity and hydrogen bonding ability of the surrounding medium it is important to understand the mechanism of energy deactivation. 3-hydroxychromone (3HC) is one of the basic chromophoric units of naturally occuring flavonoides which can form an intramolecular hydrogen bond. Studies in gas phase and in hydrocarbon solution have reveiled a proton transfer in the excited state similar to 3HF but with significant differences in the emission properties. Results from condensed phase sub-picosecond time resolved absorption spectroscopy are presented and compared to quantum chemical calculations allowing for the identification and characterization of photoinduced processes and intermediate states.