Photoelectron Spectroscopy and Computational Studies of Molecules with Delocalized Electronic Structure and Extended Electronic Structure Interactions

Persistent Link:
http://hdl.handle.net/10150/203484
Title:
Photoelectron Spectroscopy and Computational Studies of Molecules with Delocalized Electronic Structure and Extended Electronic Structure Interactions
Author:
Head, Ashley Lauren Rose
Issue Date:
2011
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:
The localized model of a chemical bond has had a long and prominent role in chemistry, but situations of extended charge delocalization and dipole effects remain topics in need of greater understanding. Both orbital delocalization in isolated molecules and induced molecular dipoles in condensed phases serve to move electron density and influence the chemical and physical properties of a system. This dissertation studies these aspects of electronic structure for selected organic, inorganic, and organometallic systems by means of electronic structure calculations and photoelectron spectroscopy, which is well-suited for studying both intramolecular and intermolecular effects by providing a direct probe of orbital energies and characters. Photoelectron spectra of P₄ and AsP₃ reveal differences in the molecular symmetry and cationic state effects between the two molecules in Chapter 3. Despite these differences, AsP₃ is found to have electron delocalization and vibrational structures that are comparable to P₄. A similar study of the delocalized -system of 2H-1,2,3-triazole in Chapter 4 relates the vibrational structure in photoelectron spectroscopy data to a series of Rydberg excitations in the vacuum UV photoabsorption spectrum. Chapters 5 and 6 examine extended electronic structures in organometallic complexes. The electron delocalization and charge transfer between two Ru centers along a bridging ethynediyl ligand is studied in [CpRu(CO)₂]₂(μC≡C). Details of the Ru-alkynyl interaction were explored by comparing the spectra of CpRu(CO)₂C≡CMe with CpRu(CO)₂Cl, including the -backbonding ability of alkynyl ligands. Chapter 6 moves from the realm of intramolecular effects to intermolecular interactions to understand how surrounding media affect electronic properties of molecules. The reversal of ionization energies between the gas and solid phases of M(CO)₄dmpe and M(CO)₄dppe, where M = Mo, W, is explored with photoelectron spectroscopy. The surrounding molecular environment stabilizes the cation, resulting in this reversal that extends to core ionization energies. The variety of systems presented illustrates the wide applicability of photoelectron spectroscopy and computations to different electronic structure studies, including how gas phase results can be related to condensed phase studies. This work continues the progress of photoelectron spectroscopy from small molecules to larger molecular systems and even further to bulk systems.
Type:
text; Electronic Dissertation
Keywords:
extended charge effects; intermolecular interactions; photoelectron spectroscopy; Chemistry; electron delocalization; electronic structure
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Lichtenberger, Dennis L.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titlePhotoelectron Spectroscopy and Computational Studies of Molecules with Delocalized Electronic Structure and Extended Electronic Structure Interactionsen_US
dc.creatorHead, Ashley Lauren Roseen_US
dc.contributor.authorHead, Ashley Lauren Roseen_US
dc.date.issued2011-
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.abstractThe localized model of a chemical bond has had a long and prominent role in chemistry, but situations of extended charge delocalization and dipole effects remain topics in need of greater understanding. Both orbital delocalization in isolated molecules and induced molecular dipoles in condensed phases serve to move electron density and influence the chemical and physical properties of a system. This dissertation studies these aspects of electronic structure for selected organic, inorganic, and organometallic systems by means of electronic structure calculations and photoelectron spectroscopy, which is well-suited for studying both intramolecular and intermolecular effects by providing a direct probe of orbital energies and characters. Photoelectron spectra of P₄ and AsP₃ reveal differences in the molecular symmetry and cationic state effects between the two molecules in Chapter 3. Despite these differences, AsP₃ is found to have electron delocalization and vibrational structures that are comparable to P₄. A similar study of the delocalized -system of 2H-1,2,3-triazole in Chapter 4 relates the vibrational structure in photoelectron spectroscopy data to a series of Rydberg excitations in the vacuum UV photoabsorption spectrum. Chapters 5 and 6 examine extended electronic structures in organometallic complexes. The electron delocalization and charge transfer between two Ru centers along a bridging ethynediyl ligand is studied in [CpRu(CO)₂]₂(μC≡C). Details of the Ru-alkynyl interaction were explored by comparing the spectra of CpRu(CO)₂C≡CMe with CpRu(CO)₂Cl, including the -backbonding ability of alkynyl ligands. Chapter 6 moves from the realm of intramolecular effects to intermolecular interactions to understand how surrounding media affect electronic properties of molecules. The reversal of ionization energies between the gas and solid phases of M(CO)₄dmpe and M(CO)₄dppe, where M = Mo, W, is explored with photoelectron spectroscopy. The surrounding molecular environment stabilizes the cation, resulting in this reversal that extends to core ionization energies. The variety of systems presented illustrates the wide applicability of photoelectron spectroscopy and computations to different electronic structure studies, including how gas phase results can be related to condensed phase studies. This work continues the progress of photoelectron spectroscopy from small molecules to larger molecular systems and even further to bulk systems.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectextended charge effectsen_US
dc.subjectintermolecular interactionsen_US
dc.subjectphotoelectron spectroscopyen_US
dc.subjectChemistryen_US
dc.subjectelectron delocalizationen_US
dc.subjectelectronic structureen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorLichtenberger, Dennis L.en_US
dc.contributor.committeememberCorrales, Renéen_US
dc.contributor.committeememberMonti, Oliveren_US
dc.contributor.committeememberSanov, Andreien_US
dc.contributor.committeememberWalker, F. Annen_US
dc.contributor.committeememberLichtenberger, Dennis L.en_US
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