Dissociative photoionization studies of ethyl iodide using synchrotron radiation photoionization mass spectrometry and photoelectron imaging

The stepwise dissociative photoionization of ethyl iodide(C2H5I) has been investigated via synchrotron radiation photoionization mass spectrometry and photoelectron imaging spectroscopy. By using VUV synchrotron radia-tion as excitation source, the photoionization and stepwise dissociative photoionization of C2H5I were observed by tuning the photon energy from 8.5 to 14.0 eV. The ionization energy of C2H5I was measured to be 9.33 +/- 0.05 eV, and the appearance energies of C2H5+, C2H4+, C2H3+ were also determined according to the photoioni-zation efficiency spectra. The possible pathways of the stepwise dissociation of C2H5I were determined by combining the experiments with theoretical calculation based on DFT. Finally, the multi-photon ionization process of C2H5I molecule was further studied via intensity-dependent photoelectron imaging spectroscopy.