Studies On VUV Photoionization And Combustion Of Some C₃ Oxygen-Contained Compounds

This dissertation includes two parts. The first part describes the VUV photoionization and dissociative photoionization of C₃ oxygen-contained compounds, i.e. acetone (AC), 2-propanol (isopropanol, IPA) and 1-propanol (n-propanol, NPA) using synchrotron radiation. The dissociation channels of these three compounds are established with the help of ab initio calculation. The second one deals with the identification and the determination of mole fractions of combustion intermediates of six C₃ oxygenated hydrocarbons/oxygen flames, using synchrotron radiation photoionization combined with molecular beam mass spectrometry.Part I VUV photoionization and dissociative photoionization studies of C₃ oxygenated compounds(1) The method of photoionization mass spectrometry using synchrotron radiation is introduced, together with the fundamental photoionization mechanism. The VUV beamline and combustion endstation at the National Synchrotron Radiation Laboratory in Hefei are described briefly. It is the first time to study the ionization of such species by using synchrotron radiation, combined with reflectron time-of-flight mass spectrometry (RTOF-MS).(2) The photoionization and dissociative photoionization of acetone have been studied at the photon energy range of 8 - 20 eV. The ionization energy (IE) of the molecule, CH₃COCH₃, and the appearance energies (AEs) of the fragment ions, CH₃⁺, C₂H₃⁺, C₃H₃⁺, C₃H₅⁺, CH₂CO⁺, CH₃CO⁺, C₃H₄O⁺ and CH₃COCH₂⁺ have been measured. Besides the common fragment CH₃CO⁺, some new fragments are also observed, including C₃H₃⁺, C₃H₅⁺ and CH₃COCH₂⁺. With the help of G3 results, the dissociation channels for the formation of the fragment ions CH₃CO⁺, CH₂CO⁺, CH₃⁺,...