Study On Photodissociation Dynamics Of Toluene Molecule By Using Synchrotron Radiation VUV Photoionization Mass Spectrometry

The photodissociation dynamics of toluene molecule is an important basic research topic in physics,chemistry,and atmospheric environmental science.This dissertation,the dissociative photoionization of Toluene have been investigated with supersonic molecule beam,synchrotron radiation and the reflectron time-of-flight mass spectrometer,obtaining the ionization energies(IE)of the parents molecules,appearance energies(AE)of the main fragments ions and the dissociation energies(Ed)to produce them.And then,the total energies of molecules and the parent cation and daughter cations will be calculated using the G3 of Gaussian 03 program.Combined with the results of the experimental data,the dissociation mechanisms on their dissociative photoionization have been discussedThe toluene is experimentally studied with tunable VUV synchrotron photoionization in the photon energy range of 7.5~25.5 eV.The single ionization energy and double ionization energy of Toluene were 8.82 eV and 23.90 eV,respectively.At the same time,the appearance energies of C7H7+,C6H5+,C5H6+,C5H5+,C5H3+,C4H5+,C4H4+,C4H3+,C4H2+,C3H3+ and C2H3+ are determined with photoionization efficiency,most of the experimental AEs of fragment ions are in agreement with available published experimental data.Meanwhile,the photoionization and dissociation photoionization of toluene have been studied using quantum chemistry methods.The ionization energy(IE)of toluene and the appearance energies(AEs)for major fragment ions,C7H7+,C5H6+,C5H5+ are determined to be 8.90,11.15 or 11.03,13.69,16.28 eV,respectively,which are all in good agreement with experimental data.The mechanisms of the dissociative photoionization pathways of C7H7+,C5H6+,C5H5+ are also detailed discussed on the basis of theoretical and experimental data.In addition,the transition and intermediates states involving in the pathways are also obtained by theoretical calculations and described in detail in this work.In this study,we will provide reference information of the photodissociation dynamics of toluene molecule for atomic and molecular databases,and provide the basis for the prevention and control of toluene pollution in the atmosphere.