Ultrafast linear and non-linear spectroscopy : from biological light-receptors to artificial light-harvesting systems
In the experiments presented in this work, linear and non-linear femtosecond time-resolved spectrsocopy were applied to investigate the structure-function and functiondynamics relationship in biological and artificially designed systems. The experiments presented in this work utilize femtosecond time-resolved transient absorption and transient grating as well as picosecond time-resolved fluorescence spectroscopy to investigate the photophysics and photochemistry of biological photoreceptors and address the light-induced excited-state processes in a particular molecular device that serves as a - structurally - very simple light-harvesting antenna and potentially as a catalysis-switch for the production of hydrogen in solution. The combination of white-light probe transient absorption and coherent transient grating spectroscopies yields spectral information about the excited state absorption in concert with high quality, high signal-to-noise kinetic transients, which allow for precise fitting and therefore very accurate time-constants to be extracted from the data. The use of femtosecond time-resolved transient grating spectroscopy is relatively uncommon in addressing questions concerning the excited-state reaction pathways of complex (biological) systems, and therefore the experiments presented in this work constitute according to the literature the first studies applying this technique to a a metalloporphyrin and an artificial light-harvesting antenna.
Femtosekunden zeitaufgelöste Spektroskopie, biologische Photorezeptoren, Übergangsmetallkomplexe, künstliche Lichtsammelsysteme, femtosecond time-resolved spectroscopy, biological photoreceptors, transition metal complexes, artificial light harvesting systems
Networked Digital Library of Theses and Dissertations