Observation and electronic properties of reactive intermediates from measurement and electronic structure calculations

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dc.contributorSzulczewski, Gregory J.
dc.contributorStreet, Shane C.
dc.contributorRupar, Paul A.
dc.contributorMewes, Tim
dc.contributor.advisorDixon, David A.
dc.contributor.authorLightcap, Johnny Clement
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.date.accessioned2018-07-11T16:49:40Z
dc.date.available2018-07-11T16:49:40Z
dc.date.issued2018
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractElectronic structure calculations were performed to understand the properties of reactive intermediates generated from experiment. Aluminum, manganese and iron nitrate anions were generated in the gas-phase via electrospray ionization (ESI) and were observed to decompose into metal oxides under collision induced dissociation (CID). Aluminum-oxygen bonds were formed after each consecutive loss of NO2•, which possess significant radical character localized to the oxygen ligands. These oxygen radicals facilitate the decomposition of Al(NO3)4- by abstracting neutral oxygen atoms and then undergoing loss of O2. Neutral oxygen atom abstraction was also observed in the decomposition of Mn(NO3)3-, however loss of NO• occurs immediately after, resulting in the rearrangement of a nitrate ligand to provide two oxygen substituents. Both MnO(NO3)2- and MnO2(NO3)- were observed to decompose under CID into the permanganate anion, MnO4-, which occurs through a pair of spin forbidden surface crossings. Fe(NO3)4- can also decompose into a tetroxide, FeO4-, however this occurs through 4 consecutive losses of NO2•, and no nitrate ligand rearrangement was observed. Oxidation of the metal center continues until MnO4- and FeO4- exist in the +VII oxidation state. Density functional theory (DFT) was used to optimize the structures for the ions and neutrals generated by ESI, and coupled cluster methods were used to calculate accurate electronic energies. DFT studies were also performed to interpret the emission spectrum of the 4-methyl-3-azabenzyl radical which was generated in a corona excited supersonic expansion source to understand how substituting a nitrogen atom into the benzene ring can change the electronic properties of aromatic radicals. Although it is possible for an electron in the nitrogen lone pair to be promoted via a charge transfer excitation, the observed emission spectrum of the 4-methyl-3-azabenzyl occurs from an unpaired electron relaxing from an antibonding orbital in the π system to a p orbital localized on the CH2 substituent. Several vibrational energies were measured and the calculated energies agree with experiment.en_US
dc.format.extent188 p.
dc.format.mediumelectronic
dc.format.mimetypeapplication/pdf
dc.identifier.otheru0015_0000001_0002991
dc.identifier.otherLightcap_alatus_0004D_13378
dc.identifier.urihttp://ir.ua.edu/handle/123456789/3676
dc.languageEnglish
dc.language.isoen_US
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.subjectChemistry
dc.titleObservation and electronic properties of reactive intermediates from measurement and electronic structure calculationsen_US
dc.typethesis
dc.typetext
etdms.degree.departmentUniversity of Alabama. Department of Chemistry
etdms.degree.disciplineChemistry
etdms.degree.grantorThe University of Alabama
etdms.degree.leveldoctoral
etdms.degree.namePh.D.
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