https://doi.org/10.1140/epjd/s10053-021-00135-2
Regular Article - Molecular Physics and Chemical Physics
VUV photoionization and dissociative photoionization of o-xylene: experimental and theoretical insights
1
School of Nuclear Science and Engineering, East China University of Technology, 330013, Nanchang, People’s Republic of China
2
National Synchrotron Radiation Laboratory, School of Nuclear Science and Technology, University of Science and Technology of China, 230029, Hefei, People’s Republic of China
3
School of Chemistry and Chemical Engineering, Qiannan Normal University for Nationalities, 558000, Duyun, People’s Republic of China
Received:
20
December
2020
Accepted:
24
March
2021
Published online:
16
April
2021
The photoionization and dissociative photoionization of o-xylene have been studied using synchrotron radiation vacuum ultraviolet light with the photon energy in the range of 8.0–13.0 eV. The ionization energy of o-xylene and the appearance energies for the main fragment ions 
, 
and 
were determined to be 8.45, 11.08, 11.47 and 11.17 eV, respectively, with photoionization efficiency spectra (PIES). Three dissociation pathways of parent ions are investigated by experimental photoionization and the quantum-chemical calculations. The fragment ions 
derived from parent ions involved hydrogen atom transfer rather than direct dissociation. Particularly, detailed mechanisms of dissociation are presented for the first time in this work. In addition, the geometries of the intermediates (INTs), transition states (TSs) and products have been performed at B3LYP/6-311 
G (d, p) level. The mechanisms of dissociative photoionization of o-xylene and the INTs and TSs involved are discussed in detail.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021
