State-resolved slice imaging of photochemical dynamics

<p>This dissertation focuses on the understanding the unimolecular photochemistry and dynamics</p> <p>utilizing state-resolved slice imaging approach combined with the quantum-state selective</p> <p>spectroscopy technique called resonance enhanced multi photon ionization (REMPI)</p> <p>method. This powerful technique allows selecting the initial quantum states of the reactants</p> <p>and determining the nal quantum states, energy, the orientation and alignments of</p> <p>the products. In the investigations of photodissociation dynamics of acetone at 230 nm,</p> <p>a bimodal distribution for the resulting CO photoproduct is identied. This observation</p> <p>indicated the presence of unimolecular dissociation mechanism analogues to the roaming</p> <p>dynamics reported in formaldehyde photodissociation. Moreover, another type of roaming</p> <p>mechanism called \roaming-mediated isomerization" is introduced in the study of nitrobenzene</p> <p>photodissociation. In this study molecules undergo roaming type isomerization</p> <p>before the simple bond ssion take place. In the study of photodissociation dynamics of</p> <p>tertachloroethylene (TCE) at 235 nm and 202 nm using state resolved slice imaging approach</p> <p>illustrate that the dissociation take place at the ground state despite the dierence in</p> <p>the excitation energies. A similar spin-orbit branching ratio of Cl/Cl* at both wavelengths</p> <p>are observed due to the above dynamical behavior of the molecule. In the study of HNO3</p> <p>photodissociation near 204 nm report the translational energy and angular momentum distributions</p> <p>of the resulting O(1D) product. The vibrational energy distribution of the HONO</p> <p>co-product, as seen through the O(1D) translational energy distribution, shows signicant vibrational energy remaining in the molecule. Analysis of the angular distributions from</p> <p>both the 1F3 <-- <-- 1D2 and 1P1 <-- <-- 1D2 O probe transitions oer additional insight into the</p> <p>dynamics of the dissociation of nitric acid through the S3 (2 1A0 ) excited state, helping to</p> <p>resolve some outstanding questions and pointing the way to future studies. This approach</p> <p>allowed us to identify new mechanisms and channels created during the photodissociation</p> <p>events, calculate the branching ratios and infer the complex reactive processes in combustion,</p> <p>atmospheric and interstellar chemistry.</p>

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Open Access Dissertation

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2012

Author dc:creator

• Herath, Herath mudiyans nuradhika

Contributors dc:contributor

• Arthur G. Suits

• Dynamics, Photochemistry, State-resolved
• Chemistry
• Physical Chemistry

Repository record dc:identifier

https://digitalcommons.wayne.edu/oa_dissertations/508

OAI identifier oai:identifier

oai:digitalcommons.wayne.edu:oa_dissertations-1507