Spectres d'absorption dans l'ultraviolet lointain des iodures de méthyle et d'éthyle et du bromure d'éthyle, gazeux et solides

Electronic excitation and oscillator strength of ethyl iodide by VUV photoabsorption and electron energy loss spectroscopy

“…For the lowest energy valence absorption band, the cross section value reported in Fig. 3 agrees with that deduced from the extinction coefficient 9,39 and with that measured previously 2,3 at 260 nm.…”

Electronic excitation and oscillator strength of ethyl bromide by vacuum ultraviolet photoabsorption and electron energy loss spectroscopy

“…1 agrees with that deduced from the extinction coefficients. 9,11 For the Rydberg state region, as shown in Fig. 3, the photoabsorption spectrum is similar to the normalized EEL spectrum.…”

“…Subsequently, the photoabsorption spectra and extinction coefficients of ethyl bromide have been measured in the region of the valence A band and of the lowest energy Rydberg features, for both gas and condensed phases. 11 Around the ionization thresholds ͑10-10.65 eV͒, the value of the absorption cross section is modulated by electron promotion into Rydberg orbitals with large quantum numbers. Between 10.65 and 10.8 eV, the cross section is nearly constant ͑62 Mb͒ before increasing steeply up to at least 11.8 eV.…”

Valence and Rydberg states of ethyl iodide by electron energy loss spectroscopy

“…In nearly optical conditions the lowest energy A band starting at 4.1 eV is weak, broad and centred at 4.78 eV (figures 1 and 5). region is of I :20. ratio larger than by uv photoabsorption where the ratio is of 1 : 150 (Robin 1974) (even taking into account the line width) and the oscillator strength of 0.0102 (Astoin et al 1958). This band has been interpreted as due to the excitation of an electron from the 4a' iodine lone-pair orbital to the lowest energy C-I anlibonding valence orbital.…”