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Area of Science:

  • Physical Chemistry
  • Chemical Physics
  • Molecular Spectroscopy

Background:

  • Nitrobenzene anion is a key molecule for studying electron dynamics.
  • Understanding energy relaxation pathways in excited anions is crucial for chemical physics.
  • Previous reports proposed reverse internal conversion, but direct evidence was lacking.

Purpose of the Study:

  • To provide direct experimental evidence for reverse internal conversion in the excited nitrobenzene anion.
  • To investigate the robustness of reverse internal conversion across multiple electronic states.
  • To elucidate the role of reverse internal conversion in the energy relaxation of excited anionic states.

Main Methods:

  • Time-resolved photoelectron spectroscopy using electron detection.
  • Analysis of photoelectron spectra at significantly delayed times post-laser interaction.
  • Observation of autodetached photoelectrons and thermionic emission.

Main Results:

  • Direct experimental evidence of reverse internal conversion in excited nitrobenzene anion was obtained.
  • Autodetached photoelectrons from dipole-bound states were observed concurrently with thermionic emission.
  • Reverse internal conversion was found to be robust across multiple electronically excited states.

Conclusions:

  • The findings confirm the proposed mechanism of reverse internal conversion in nitrobenzene anion.
  • Reverse internal conversion is a significant factor in the energy relaxation of excited anionic states.
  • This process may be a general phenomenon in excited anionic systems.