Picosecond photoinduced formation of a radical cation: CARS and transient absorption studies of 1,4-diphenylbutadiene
Résumé
We report the direct observation of the formation and stabilization of the radical cation of 1,4-diphenylbutadiene (DPB) in polar solvents (acetonitrile, linear alcohols) by picosecond “pump-probe” and polarization-sensitive resonant CARS (Coherent Anti-Stokes Raman Scattering) experiments. For the first time, we have observed the formation and stabilization rate of the DPB radical cation which occurs on a 10–20 ps timescale. We confirm that the formation process is mainly monophotonic.