Dresden 2009 – scientific programme
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DF: Fachverband Dielektrische Festkörper
DF 10: Photonic Dielectrics I
DF 10.2: Talk
Wednesday, March 25, 2009, 10:40–11:00, WIL A317
Photoswitchable [Ru(bpy)2(OSO)]PF6 molecules for nonlinear opto-fluidics — •Volker Dieckmann1, Sebastian Eicke1, Mirco Imlau1, Nicholas V. Mockus2, Theo Woike2, and Jeffrey J. Rack3 — 1Department of Physics, University of Osnabrück, Barbarastr. 7, D-49069 Osnabrück — 2I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln — 3Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701
The studies on [Ru(bpy)2(OSO)]PF6 (OSO: 2-methylsulfinylbenzoate) characterize the photoswitchability of the molecules concerning the activation energy, the spectral range and the lifetime of the excited states at room temperature. The kinetics of the generation of excited states and their thermal decay were determined by pump-probe technique: The absorption of the solution was probed by 532 nm light during and after pumping with 405 nm light. Two fully reversible thermal decay processes following Arrhenius law (EA,I = (1.0±0.2) eV and EA,II = (0.7±0.1) eV) have been identified. Additionally, absorption spectroscopic studies reveal a photosensitivity and strong absorption changes in the UV spectral range. The lifetimes of the photo-excited states in [Ru(bpy)2(OSO)]PF6 solutions at room temperature have been determined to τI≈ 1.4· 105 s and τII≈ 4· 103 s, respectively. In conclusion, this compound extends the class of photoswitchable molecules to molecules with long lifetimes at room temperature. The application of [Ru(bpy)2(OSO)]PF6 for nonlinear optofluidic systems will be discussed taking into account tuning ability of lifetime and spectral sensitivity. Financial support by the DFG (GRK 695).