Slow photoelectron spectroscopy of 3-hydroxyisoquinoline.
We studied the single photon ionization of gas phase 3-hydroxyisoquinoline by means of VUV synchrotron radiation coupled to a velocity map imaging electron/ion coincidence spectrometer. Near the ionization thresholds of 3-hydroxyisoquinoline, the photoionization is found to occur mainly via a direct process. The spectra are assigned with the help of theoretical calculations on the equilibrium geometries, electronic states patterns, harmonic and anharmonic wavenumbers of the lactim and lactam forms of 3-hydroxyisoquinoline and their cations. The slow photoelectron spectrum (SPES) of this lactim is dominated by vibrational transitions to the X̃ state of the cation. In addition, several weaker and complex bands are observed, corresponding to the population of the vibrational bands (pure or combination) of the Ã electronically excited state of the cation. The adiabatic ionization energy of 3-hydroxyisoquinoline and the lowest electronic state energetics of the lactim and lactam cationic forms are determined.
Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong.
Yi
Y
Pan
Kai-Chung
KC
Lau
Lionel
L
Poisson
Gustavo A
GA
Garcia
Laurent
L
Nahon
Majdi
M
Hochlaf
D000998:Antiviral Agents / Q000737:chemistry; D004583:Electrons; D005740:Gases; D007546:Isoquinolines / Q000737:chemistry*; D007769:Lactams / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D017785:Photons; D017356:Synchrotrons; D013816:Thermodynamics
D000998:Antiviral Agents; D005740:Gases; D007546:Isoquinolines; D007769:Lactams