I. Experimental test of 'carbon monoxide self-shielding' in the early solar nebula using ultra-high resolution VUV photodissociation & photoionization. II. Laser ablation, photodissociation, and photoionization of transition-metal compounds.

摘要

Vacuum ultraviolet (VUV) laser spectroscopy, laser ablation, photoion and photoelectron imaging are powerful physical chemistry methods used to study the kinetics of molecules and the dynamics of reactions. This fundamental information is required by astrochemists to test cosmochemical models, and to properly interpret and separate intermingled spectra of molecules in space. The first half of this dissertation discusses our experimental results from testing the "carbon monoxide self-shielding" (COSS) model using laser spectroscopy. Our results reproduced the mass-independent oxygen anomaly observed in the solar system, which confirmed the validity of the model. Additionally, we discuss the results of our photoion imaging study on CO. This study evaluated the chemical pathways of oxygen atoms that are generated from the self-shielded photodissocaiton of CO. The second half of the dissertation focuses on our photoionization studies and theoretical studies on nickel atoms and nickel carbide. This study is the first to accurately measure the ionization energy of NiC. The resulting high-resolution spectra revealed previously unknown electronic transitions of Ni and NiC, which can be used to interpret space spectra, and to benchmark theoretical computations of transition-metal-bearing compounds.