Darmstadt 2008 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 6: Photochemie II

MO 6.5: Vortrag

Dienstag, 11. März 2008, 12:00–12:15, 3F

Coherently Controlled Release of Drugs in the Ophtalmology — •Tiago Buckup, Jens Möhring, Volker Settels, Jens Träger, Hee-Cheol Kim, Norbert Hampp, and Marcus Motzkus — Physikalische Chemie, Philipps Universität Marburg, D-35043 Marburg, Germany

The release of drugs using photochemical cleavable link molecules is an important method in the modern treatment of eyes diseases. The decisive step in this application is the controlled cleavage of the coumarin dimer link system using two-photon excitation. This way, the photochemical release can be exclusively controlled with laser irradiation when required and not triggered with day light. In this work, we investigate in open- and closed-loop control schemes the optimal pulse solution to achieve an efficient two-photon induced cleavage. The optimization of the dicoumarin cleavage reaction was performed using the shaped emission of a non-collinear optical parametric amplifier at 532nm in a novel accumulation absorption setup based on a capillary as probe holder. In this setup, a defined sample volume is irradiated for a short period with a tailored pulse and the reaction conversion efficiency is probed at 310nm, the absorption maximum of the coumarin monomer. Closed-loop optimizations targeting the maximization of the reaction yield and the minimization of a two-photon dependent signal shows that a Fourier-limited pulse (18fs) is not the best suitable pulse to steer the reaction. Principal component analysis and open-loop scans with defined parameterizations are used to investigate the optimal solutions.