Studies of Transition States, Clusters, and Radicals by Negative Ion Photodetachment and Photodissociation

Abstract

Our AFOSR-supported research during the last three years focused on several experimental programs at the interface of ion spectroscopy and molecular reaction dynamics. We have developed a new method for high resolution photodetachment spectroscopy of negative ions based on photoelectron imaging (SEVI, or Slow photoElectron Velocity-map Imaging) and applied it to simple test systems as well as a pre-reactive van der Waals complex. We have measured photoelectron spectra of solvated transition state precursor anions, and used the vibrational structure in these spectra to infer to effect of various solvents on the strong hydrogen bond in the anion core. This work led to a series of experiments in which we measured the infrared spectra of several strongly hydrogen-bonded anions and the protonated water dimer H5O2+. These experiments were performed on the Free Electron Laser for Infrared experiments (FELIX) which produces high power, tunable infrared pulses over a broad spectral range, enabling the first measurements of the low (<1000 cm-1) frequencies associated with the large amplitude motion of the shared proton in these ions. Finally, we investigated the photodissociation dynamics of the CIN3 molecule at 248 nm using molecular beam photofragment translational spectroscopy, determining that the "conventional wisdom" regarding its primary photochemical branching was totally incorrect.

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Document Details

Document Type
Technical Report
Publication Date
Apr 24, 2006
Accession Number
ADA448625

Entities

People

  • Aster Kammrath
  • Daniel Neumark
  • Etienne Garand
  • Graham Griffin
  • Jeong H. Kim
  • Katherine Kautzman
  • Mark Abel
  • Nathan Bartlett
  • Paul Crider
  • Scott Goncher

Organizations

  • University of California, Berkeley

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Chemical Reactions
  • Chemistry
  • Dynamics
  • Electrons
  • Energy Bands
  • Free Electron Lasers
  • Free Electrons
  • High Resolution
  • Hydrogen Bonds
  • Lasers
  • Photodissociation
  • Photoelectron Spectra
  • Photoelectrons
  • Physical Chemistry
  • Physics
  • Spectra
  • Spectroscopy

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Quantum Chemistry

Technology Areas

  • AI & ML
  • Directed Energy
  • Microelectronics