Electronic Structure, Intermolecular Interactions and Electron Emission Dynamics via Anion Photoelectron Imaging

Persistent Link:
http://hdl.handle.net/10150/195933
Title:
Electronic Structure, Intermolecular Interactions and Electron Emission Dynamics via Anion Photoelectron Imaging
Author:
Grumbling, Emily Rose
Issue Date:
2010
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This dissertation explores the use of anion photoelectron imaging to interrogate electronic dynamics in small chemical systems with an emphasis on photoelectron angular distributions. Experimental ion generation, mass selection, laser photodetachment and photoelectron imaging were performed in a negative-ion photoelectron imaging spectrometer described in detail. Results for photodetachment from the simplest anion, H⁻, are used to illustrate fundamental principles of quantum mechanics and provide basic insight into the physics behind photoelectron imaging from a pedagogical perspective. This perspective is expanded by introducing imaging results for additional, representative atomic and small molecular anions (O⁻, NH₂⁻ and N₃⁻) obtained at multiple photon energies to address the energy-dependence of photoelectron angular distributions both conceptually and semi-quantitatively in terms of interfering partial photoelectron waves. The effect of solvation on several of these species (H⁻, O⁻, and NH₂⁻) is addressed in photoelectron imaging of several series of cluster anions. The 532 and 355 nm energy spectra for H⁻(NH₃)n and NH₂⁻(NH₃)n (n = 0-5) reveal that these species are accurately described as the core anion solute stabilized electrostatically by n loosely coordinated NH3 molecules. The photoelectron angular distributions for solvated H⁻ deviate strongly from those predicted for unsolvated H⁻ as the electron kinetic energy approaches zero, indicating a shift in the partial-wave balance consistent with both solvation-induced perturbation (and symmetry-breaking) of the H⁻ parent orbital and photoelectron-solvent scattering. The photoelectron energy spectra obtained for the cluster series [O(N₂O)n]⁻ and [NO(N₂O)n]⁻ indicate the presence of multiple structural isomers of the anion cores, the former displaying sharp core-switching at n = 4, the latter isomer coexistence over the entire range studied. The photoelectron angular distributions for detachment from the O⁻(N₂O)n and NO⁻(N₂O)n isomers deviate strongly from those expected for bare O⁻ and NO⁻, respectively, in the region of an anionic shape resonance of N₂O, suggesting resonant photoelectron-solvent scattering. Partial-wave models for two-centered photoelectron interference in photodetachment from dissociating I₂⁻ is presented and discussed in the context of previous results. New time-resolved photoelectron imaging results for I₂⁻, for both parallel and perpendicular pump and probe beam polarizations, are presented and briefly discussed. Finally, new ideas and directions are proposed.
Type:
text; Electronic Dissertation
Keywords:
anions; clusters; gas-phase; laser spectroscopy; photodetachment dynamics; photoelectron imaging
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Sanov, Andrei
Committee Chair:
Sanov, Andrei

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleElectronic Structure, Intermolecular Interactions and Electron Emission Dynamics via Anion Photoelectron Imagingen_US
dc.creatorGrumbling, Emily Roseen_US
dc.contributor.authorGrumbling, Emily Roseen_US
dc.date.issued2010en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis dissertation explores the use of anion photoelectron imaging to interrogate electronic dynamics in small chemical systems with an emphasis on photoelectron angular distributions. Experimental ion generation, mass selection, laser photodetachment and photoelectron imaging were performed in a negative-ion photoelectron imaging spectrometer described in detail. Results for photodetachment from the simplest anion, H⁻, are used to illustrate fundamental principles of quantum mechanics and provide basic insight into the physics behind photoelectron imaging from a pedagogical perspective. This perspective is expanded by introducing imaging results for additional, representative atomic and small molecular anions (O⁻, NH₂⁻ and N₃⁻) obtained at multiple photon energies to address the energy-dependence of photoelectron angular distributions both conceptually and semi-quantitatively in terms of interfering partial photoelectron waves. The effect of solvation on several of these species (H⁻, O⁻, and NH₂⁻) is addressed in photoelectron imaging of several series of cluster anions. The 532 and 355 nm energy spectra for H⁻(NH₃)n and NH₂⁻(NH₃)n (n = 0-5) reveal that these species are accurately described as the core anion solute stabilized electrostatically by n loosely coordinated NH3 molecules. The photoelectron angular distributions for solvated H⁻ deviate strongly from those predicted for unsolvated H⁻ as the electron kinetic energy approaches zero, indicating a shift in the partial-wave balance consistent with both solvation-induced perturbation (and symmetry-breaking) of the H⁻ parent orbital and photoelectron-solvent scattering. The photoelectron energy spectra obtained for the cluster series [O(N₂O)n]⁻ and [NO(N₂O)n]⁻ indicate the presence of multiple structural isomers of the anion cores, the former displaying sharp core-switching at n = 4, the latter isomer coexistence over the entire range studied. The photoelectron angular distributions for detachment from the O⁻(N₂O)n and NO⁻(N₂O)n isomers deviate strongly from those expected for bare O⁻ and NO⁻, respectively, in the region of an anionic shape resonance of N₂O, suggesting resonant photoelectron-solvent scattering. Partial-wave models for two-centered photoelectron interference in photodetachment from dissociating I₂⁻ is presented and discussed in the context of previous results. New time-resolved photoelectron imaging results for I₂⁻, for both parallel and perpendicular pump and probe beam polarizations, are presented and briefly discussed. Finally, new ideas and directions are proposed.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectanionsen_US
dc.subjectclustersen_US
dc.subjectgas-phaseen_US
dc.subjectlaser spectroscopyen_US
dc.subjectphotodetachment dynamicsen_US
dc.subjectphotoelectron imagingen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSanov, Andreien_US
dc.contributor.chairSanov, Andreien_US
dc.contributor.committeememberMonti, Oliver L. A.en_US
dc.contributor.committeememberSalzman, W. Ronen_US
dc.contributor.committeememberGlass, Richard S.en_US
dc.identifier.proquest11377en_US
dc.identifier.oclc752261241en_US
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