Photofragmentation of chlorotrifluoromethane excited near the chlorine K-edge

Photodissociation of CF3Cl excited near the chlorine K-edge (≈2.8 keV) using synchrotron radiation has been studied in two separate experiments, both using time-of-flight mass spectrometry and multi-ion coincidence techniques. In the first experiment, double-ion coincidences are analyzed with photo-ion photo-ion momentum correlation methods (PEPIPICO), extended in this dissertation to five-body dissociations and multiply charged ions. This approach is supplemented by identification of kinetic energy release distributions (KERD) of the individual fragments and their respective anisotropy parameters. A novel approach is developed in this dissertation to find the KERD and anisotropy parameters. This approach is compared in detail to others previously published and found to give comparable results. In the second experiment, triple-ion coincidences are used to identify more dissociation pathways and the mechanisms associated with them. These ion triples are analyzed with PEPIPICO techniques extended to triple-ion coincidences. In addition, a simple charge separation model is used to identify and analyze concerted dissociation processes in triple-ion coincidence data.;Concerted dissociation is the predominant dissociation mechanism, producing over 2/3 of all coincidences. Sequential processes produce the remainder. Atomic fragments result from about 90% of the events recorded, with atomic and one diatomic (CF) fragment resulting from the other 10%. The mechanism producing a given ion pair or triple is found not to vary with excitation energy over a range spanning the ionization potential, though relative probabilities for various product channels do change. Most dissociations begin from a charge state of 5+ on the parent ion. Coulomb repulsion is the primary factor in both concerted and sequential dissociations, with chemical forces playing a minor role.;In sequential processes, dissociation of fluorine ions is the first step in most events, and takes place in less than one rotational period. This fast fluorine dissociation indicates that electronic relaxation processes in the molecule may couple the Cl-core hole with (C-F) orbitals.;The experiments presented in this dissertation were performed at Beamline 9.3.1 at the Advanced Light Source at Lawrence Berkeley National Labs through collaboration with Dr. Dennis Lindle, of UNLV.