Studies in Laboratory Spectroscopy and Radio Astronomy: From Simple Hydrides to Complex Organic Molecules

Persistent Link:
http://hdl.handle.net/10150/195962
Title:
Studies in Laboratory Spectroscopy and Radio Astronomy: From Simple Hydrides to Complex Organic Molecules
Author:
Halfen, DeWayne Terrence
Issue Date:
2006
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:
There are two main objectives for this thesis. First, laboratory rotational spectra of metal-containing molecules were measured using the millimeter-wave spectrometers of the Ziurys group. Second, radio astronomical observations were performed on a number of the molecules measured in the laboratory, along with several organic species. The laboratory work is essential to the discovery of new molecules in the interstellar medium, and the understanding of the chemical composition of the universe. Identification of these species can only occur after their pure rotational spectra have been measured. Therefore, an investigation of the rotational spectra of several classes of molecules was performed including metal-bearing hydrides, chlorides, carbon-containing species, and molecular ions. The experimental measurements were aided by necessary improvements in the operation of the spectrometers. Many of these species had not been observed by any spectroscopic technique, including CaC, CuCH₃, FeCO⁺ and VCl⁺. Several of these molecules exhibited unusual interactions that complicated the analysis of their spectra, such as VCl, TiCl⁺, VCl⁺, and FeCO⁺. Synthesis of these species required exotic production techniques, including the use of Broida ovens and AC and DC discharges. Astronomical observations of several of the molecules studied in the laboratory were conducted, and upper limits to the abundances obtained. Additional searches for more of the species studied are planned. A region in the Galactic center with a complex chemical composition called Sgr B2(N) was recognized through observations of N₂O. Several organic species were then searched for in this source. The detection of the simple sugar glycolaldehyde was confirmed by observing all of the favorable transitions of this molecule in Sgr B2(N). A standard set of criteria for identifying complex organic molecules was drawn up as a result of this study. This investigation led to an attempt to confirm a larger sugar, dihydroxyacetone. Unfortunately the detection of this species was proven false, and a limit could be placed on the chemical complexity of this source.
Type:
text; Electronic Dissertation
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Ziurys, Lucy M
Committee Chair:
Ziurys, Lucy M

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleStudies in Laboratory Spectroscopy and Radio Astronomy: From Simple Hydrides to Complex Organic Moleculesen_US
dc.creatorHalfen, DeWayne Terrenceen_US
dc.contributor.authorHalfen, DeWayne Terrenceen_US
dc.date.issued2006en_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.abstractThere are two main objectives for this thesis. First, laboratory rotational spectra of metal-containing molecules were measured using the millimeter-wave spectrometers of the Ziurys group. Second, radio astronomical observations were performed on a number of the molecules measured in the laboratory, along with several organic species. The laboratory work is essential to the discovery of new molecules in the interstellar medium, and the understanding of the chemical composition of the universe. Identification of these species can only occur after their pure rotational spectra have been measured. Therefore, an investigation of the rotational spectra of several classes of molecules was performed including metal-bearing hydrides, chlorides, carbon-containing species, and molecular ions. The experimental measurements were aided by necessary improvements in the operation of the spectrometers. Many of these species had not been observed by any spectroscopic technique, including CaC, CuCH₃, FeCO⁺ and VCl⁺. Several of these molecules exhibited unusual interactions that complicated the analysis of their spectra, such as VCl, TiCl⁺, VCl⁺, and FeCO⁺. Synthesis of these species required exotic production techniques, including the use of Broida ovens and AC and DC discharges. Astronomical observations of several of the molecules studied in the laboratory were conducted, and upper limits to the abundances obtained. Additional searches for more of the species studied are planned. A region in the Galactic center with a complex chemical composition called Sgr B2(N) was recognized through observations of N₂O. Several organic species were then searched for in this source. The detection of the simple sugar glycolaldehyde was confirmed by observing all of the favorable transitions of this molecule in Sgr B2(N). A standard set of criteria for identifying complex organic molecules was drawn up as a result of this study. This investigation led to an attempt to confirm a larger sugar, dihydroxyacetone. Unfortunately the detection of this species was proven false, and a limit could be placed on the chemical complexity of this source.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorZiurys, Lucy Men_US
dc.contributor.chairZiurys, Lucy Men_US
dc.contributor.committeememberWoolf, Neville J.en_US
dc.contributor.committeememberBrown, Michael F.en_US
dc.contributor.committeememberSanov, Andreien_US
dc.contributor.committeememberBieging, John H.en_US
dc.identifier.proquest1569en_US
dc.identifier.oclc137356479en_US
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