Persistent Link:
http://hdl.handle.net/10150/184347
Title:
ELECTRON TRANSFER PROPERTIES OF ALIPHATIC SULFIDES.
Author:
COLEMAN, BRIAN RANDALL.
Issue Date:
1982
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 ease of electron loss of fifty alipathic thioethers was studied by electrochemistry, charge transfer and photoelectron spectroscopy. These compounds consisted of mesocyclic thioethers and S-methyl norbornane derivatives. Comparison of charge transfer and photoelectron ionization potential showed a good correlation. Correlation of ionization potential with anodic peak potentials showed the existence of two groups of compounds. Those compounds having an electron rich neighboring group capable of an intramolecular interaction were found to have a good correlation of ionization potential with electrochemical peak potential. For those compounds without this capability, no observable correlation was seen. Photoelectron ionization potentials of thioethers are a function of the alkyl groups attached to the sulfur atom. With substituent constants assigned to alkyl groups from measurements on simple thioethers, the ionization potential of more complicated thioethers can be calculated. Compounds whose experimental value was found to be less than the calculated value were found to fall in the group where an intramolecular neighboring group could facilitate the ease of electron loss by stabilization of the cation radical. Electrochemical peak potentials were seen to be dramatically affected by intramolecular stabilization of the cation radical. Shifts of 600-800 mV were seen for structurally similar compounds whose only difference was the availability of an electron rich neighboring group. Since the electrochemistry of these compounds exhibits irreversible behavior, the shift in peak potential could be due to a change in the formal potential, the heterogeneous rate constant, the rate of a following chemical reaction or a combination of these. Changes in the heterogeneous rate constant or chemical step rate constant alone cannot account for the magnitude of the shift seen. Thus the differences observed must be due to two different processes. In the noninteracting case, E⁰' is a measure of the formation of the cation radical, whereas, in the case of interacting compounds E⁰') is a measure of the formation of an intramolecularly stabilized cation radical where bond formation has occurred. Evidence for the structure of some intramolecular stabilized intermediates is presented. An electron deficient thioether which is a model for biological systems was shown to be capable of phosphorylating adenine nucleotides.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Aliphatic compounds -- Electric properties.; Photoelectron spectroscopy.; Charge transfer.; Electrochemistry.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Wilson, George S.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleELECTRON TRANSFER PROPERTIES OF ALIPHATIC SULFIDES.en_US
dc.creatorCOLEMAN, BRIAN RANDALL.en_US
dc.contributor.authorCOLEMAN, BRIAN RANDALL.en_US
dc.date.issued1982en_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.abstractThe ease of electron loss of fifty alipathic thioethers was studied by electrochemistry, charge transfer and photoelectron spectroscopy. These compounds consisted of mesocyclic thioethers and S-methyl norbornane derivatives. Comparison of charge transfer and photoelectron ionization potential showed a good correlation. Correlation of ionization potential with anodic peak potentials showed the existence of two groups of compounds. Those compounds having an electron rich neighboring group capable of an intramolecular interaction were found to have a good correlation of ionization potential with electrochemical peak potential. For those compounds without this capability, no observable correlation was seen. Photoelectron ionization potentials of thioethers are a function of the alkyl groups attached to the sulfur atom. With substituent constants assigned to alkyl groups from measurements on simple thioethers, the ionization potential of more complicated thioethers can be calculated. Compounds whose experimental value was found to be less than the calculated value were found to fall in the group where an intramolecular neighboring group could facilitate the ease of electron loss by stabilization of the cation radical. Electrochemical peak potentials were seen to be dramatically affected by intramolecular stabilization of the cation radical. Shifts of 600-800 mV were seen for structurally similar compounds whose only difference was the availability of an electron rich neighboring group. Since the electrochemistry of these compounds exhibits irreversible behavior, the shift in peak potential could be due to a change in the formal potential, the heterogeneous rate constant, the rate of a following chemical reaction or a combination of these. Changes in the heterogeneous rate constant or chemical step rate constant alone cannot account for the magnitude of the shift seen. Thus the differences observed must be due to two different processes. In the noninteracting case, E⁰' is a measure of the formation of the cation radical, whereas, in the case of interacting compounds E⁰') is a measure of the formation of an intramolecularly stabilized cation radical where bond formation has occurred. Evidence for the structure of some intramolecular stabilized intermediates is presented. An electron deficient thioether which is a model for biological systems was shown to be capable of phosphorylating adenine nucleotides.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectAliphatic compounds -- Electric properties.en_US
dc.subjectPhotoelectron spectroscopy.en_US
dc.subjectCharge transfer.en_US
dc.subjectElectrochemistry.en_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.advisorWilson, George S.en_US
dc.identifier.proquest8217402en_US
dc.identifier.oclc681937025en_US
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