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Ultrafast structural dynamics concomitant to excitation energy transfer in DNA is studied using a pair of pyrene-labeled DNA bases. The temporal evolution of the femtosecond pump-probe spectra reveals the existence of two electronic coupling pathways, through-base stack and through-space, which lead to excitation energy transfer and excimer formation, the local structural dynamics and flexibility and flexibility of DNA are characterized on the picosecond and nanosecond time scale.

Intramolecular bichromophoric coupling and structural relaxation in pyrene and aryl pyrene derivatives in solution is studied using femtosecond broad-band pump-probe spectroscopy. The experimental set-up, the data acquisition procedure, and several experimental details about the characterization of the broad-band femtosecond white light source are described.

A study was conducted to extend femtochemistry to the investigations of reactions in nanocavities. The experiment probed the intramolecular reactions of cyclodextrin in water solutions and the impact of confined geometries on their dynamics. In particular, the focus of the study was on the dynamics of intramolecular proton transfer and isomerization with femtosecond time resolution in beta-cyclodextrin with a cavity diameter of equivalent8 A. The experiment and its results are discussed.

A model was developed for the femtosecond, real-time dynamics of a hydrogen-bonded model base pair (7-azaindole dimer) in the condensed phase and compared with gas-phase, molecular beam investigations. After the production of a wave packet, the initial decay of the reactive pair and the rise of the tautomer in two solvents was resolved. Analyses of the isotope effect, solvent viscosity, energy dependence and polarization anisotropy were in agreement with direct and indirect reaction pathways for double proton transfer on a global potential energy surface.

The double proton transfer dynamics of 7-AI dimers in solution were compared with previous gas-phase studies.