Vacuum ultraviolet electron impact excitation of the styrene molecule: cross sections and oscillator strengths

The vacuum ultraviolet electronic excitation of the styrene molecule has been studied in the 0-50 eV energy range, using angle-resolved electron-energy-loss spectroscopy at an incident energy of 1 keV. Intense new features have been observed at 10.3, 11.8, 13.7 and 17.1 eV. They were tentatively assigned to high-energy transitions originating from sigma electrons or to double excitations involving p electrons. The absolute generalized oscillator strengths and absolute inelastic differential cross sections have been determined for the band centred at 5.3 eV, associated with the 2,3 (1)A <- 1 (1)A' transitions. The absolute elastic differential cross section has also been determined over an angular range of 2.5 degrees-22.0 degrees. The valence photoabsorption spectrum of styrene, derived from the electron-energy-loss spectrum, is compared to a previously measured benzene spectrum in the 3-45 eV energy range.