Work Group Prof. Dr. F. Temps

Femtosecond spectroscopy

Femtosecond spectroscopy allows us to follow the motion of a wavepacket prepared by an ultrashort laser pulse on the excited-state potential energy hypersurface through the conical intersection (CoIn) mediating the radiationless transition from the excited state (usually S1) to the ground state (S0). The quantum yields for photoproduct formation and radiationless electronic deactivation are decided by the dynamics of the wavepacket in the vicinity of the CoIn. Our major research themes "Photostability of the DNA and its Building Blocks" and "Dynamics of Functional Photochromic Molecular Switches" are therefore closely related.

  

Ground- and Excited-State Potential Energy Hypersurfaces with Conical Intersection
Wavepacket motion on the excited potential energy hypersurface through the conical intersection
(CoIn) connecting the excited state (S1) with the ground state (S0).                            (c) F. Temps

     

In ideal cases, the experimentally observed dynamics can be directly assigned to the motion of specific atoms or functional groups in a molecule (e.g. hexa- and pentafluorobenzene).