Positive and negative photoion spectroscopy study of C₂Cl₄

Estimate of the C−Cl photoionization cross section and absolute photoionization cross sections of chlorinated organic compounds

“…TCE's ionization threshold value of 9.33±0.05 eV agrees with the literature value of 9.3256±0.0006 eV [36] and the CBS‐QB3 calculated value of 9.32 eV. There are no dissociative ionization fragments present in the photon energy range of this study (8.9–11 eV); the first dissociative ionization fragment indicating chlorine loss, C 2 Cl 3 + , was observed at 12.62±0.05 eV by Chu et al [37] …”

“…TCE's ionization threshold value of 9.33 � 0.05 eV agrees with the literature value of 9.3256 � 0.0006 eV [36] and the CBS-QB3 calculated value of 9.32 eV. There are no dissociative ionization fragments present in the photon energy range of this study (8.9-11 eV); the first dissociative ionization fragment indicating chlorine loss, C 2 Cl 3 + , was observed at 12.62 � 0.05 eV by Chu et al [37] The first spectral band starting at 9.33 eV is the result of the removal of an electron from the HOMO, which has mostly C=C π-bonding and some CÀ Cl π-antibonding character as shown in Figure 3. This is evidenced by the elongation of the CÀ C bond upon ionization, extending from 1.342 Å to 1.427 Å (bonding character), and the shortening of the CÀ Cl bonds from 1.727 Å to 1.676 Å (antibonding character).…”