Single-photon absorption of liquid methanol and ethanol in the vacuum ultraviolet

The single-photon absorption spectra of pure liquid methanol and ethanol have been measured for the first time, between 6 and 10.8 eV, with the help of a new technique specially developed for the detection of vacuum ultraviolet synchrotron beams normally transmitted through thin (1±0.5 μm) liquid films. The experimental results are presented and analysed with reference to the published spectrophotometric data on low-lying Rydberg states of gaseous alcohols and solid rare gases. Energy relaxation is briefly discussed in the light of the current works on water radiolysis and photolysis.