I'm glad you are interested in my recent research activities. Since May 2000 I was doing my PhD-studies here, at the Chair for BioMolecular Optics, Ludwig-Maximilians-University in Munich.
My doctoral work focussed on "Ultrafast photoinduced intra- and intermolecular charge transfer and solvation"
(see abstract in english or german).
I obtained a PhD degree in physics in December 2004. Right now I am looking for a new challenge
(see my application documents in german).
This page is to present the topics of my research work.
I studied various molecular systems in solution by pump-probe
femtosecond spectroscopy and steady-state fluorescence
in order to explore the dynamics of the fundamental photoinduced processes .
Following the excitation of their structural subunits, triphenylmethane lactones undergo
ultrafast photoinduced electron transfer
with the formation of a radical ion pair of their structural subunits. This formation is observed with a time constant of 50 fs,
what is one of the fastest intramolecular electron transfer observed.
After its photoexcitation, the biochromophore
indole in water shows interesting dual behavior of fluorescence on a nanosecond time
scale and photoionization within 60 fs. This phenomenon is explained with an ultrafast branching occurring immediately after
excitation, dividing excited indole population into a fraction which exhibits a La/Lb state reversal and a fraction that undergoes
photoionization generating indole radicals and solvated electrons. The electron solvation dynamics is resolved to occur with a time
constant of 350 fs.
Internal conversion (IC), an important nonradiative process occurring in organic compounds
upon the UV radiation, is explored in o-hydroxybenzaldehyde (OHBA), a molecule that exhibits
excited state intramolecular proton transfer (ESIPT).
It is shown that the IC of OHBA proceeds as a thermally activated process over an energy barrier of about 200 meV
caused by an avoided crossing. The IC shows pure statistical behavior depending on the total excitation photon energy although the
ESIPT is a balistic motion of a well-defined wavepacket.
Thus, the coordinates involved in the ESIPT and in the IC are found
to be orthogonal.