15min:

DAVID T. ANDERSON, LEIF O. PAULSON AND SHARON C. KETTWICH, Department of Chemistry, University of Wyoming, Laramie, WY 82071-3838.

The in situ photochemistry of dopant molecules isolated in solid parahydrogen (pH₂) typically differs from analogous studies in rare gas crystals for two main reasons: (1) solid pH₂ has a negligible cage effect so that photodissociation of a precursor molecule can lead efficiently to well-separated fragments, and (2) radical fragments can potentially react with the pH₂ matrix. Our group is currently studying the 193 nm photochemistry of a number of precursor molecules isolated in solid pH₂ via high-resolution FTIR spectroscopy in hopes of identifying trapped atomic species. Currently we are revisiting the photochemistry of NO in solid pH₂ that has previously been investigated by Momose and co-workers. The 193 nm photodynamics of NO in rare gas matrices has also been extensively studied. The studies by Momose showed that NO is photolabile at 193 nm and that the product N and O atoms react to form NH₃ and H₂O, respectively. Preliminary experiments in this laboratory show evidence for the production of the imidogen (NH) radical as well, and the most recent results and analysis will be presented.