Ionization of methanol: monitoring the trapping of electrons on the fs time scale

Femtosecond spectroscopy of the photogeneration of electrons in methanol is demonstrated from the visible to the mid-infrared utilizing polarization and fs-time resolution. After two photon excitation at 9.1 eV clear evidence is provided for a preferred trapping of the electrons with τtr=100 fs within H-bonded methanol chains oriented preferentially parallel to the applied pump field. Trapping proceeds in contrast to the case of water along an excited p′-state under same experimental conditions.