Stuttgart 2012 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 17: Femtosecond Spectroscopy IV

MO 17.8: Vortrag

Donnerstag, 15. März 2012, 12:30–12:45, V38.03

Excited state dynamics and binding energies of DNA bases in aqueous solution — •Franziska Buchner and Andrea Lübcke — Max-Born-Institut, Max-Born-Strasse 2A, 12489 Berlin, Germany

Interaction of UV light with DNA may lead to photodamage. Photodamage of DNA can occur either by direct absorption of uv photons or by attachment of solvated electrons formed by a photodetachment process in the vicinity.

We report on the excited state dynamics of DNA bases in aqueous solution observed by time-resolved photoelectron spectroscopy, exploiting the liquid jet technique. Sub-100 fs pulses of 200 nm or in the range of 240-266 nm are used to excite a 1 mmolar solution of the DNA base or its sugar conjugate. Excited state dynamics is probed by photoionization with a delayed UV pulse (also sub-100 fs).

Depending on the photon energy of the pump pulse we either see formation and recombination of solvated electrons or excited state dynamics of the base itself. Both population dynamics and binding energies of the excited states will be discussed.