{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/67280"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/67280","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Nitrogen-14 Nuclear Quadrupole Resonance Studies of Pyrimidine and Purine Derivatives","abstract":"The classical and quantum mechanical descriptions of nuclear quadrupole resonance (nqr) are reviewed. Fundamental principles of nuclear spin thermodynamics are introduced to explain double resonance via level crossing (drlc), the experimental technique employed to detect ('14)N nqr resonances.","abstract_html":"The classical and quantum mechanical descriptions of nuclear quadrupole resonance (nqr) are reviewed. Fundamental principles of nuclear spin thermodynamics are introduced to explain double resonance via level crossing (drlc), the experimental technique employed to detect ('14)N nqr resonances.","abstract_has_math":false,"creators":["Mccullen, William Lynwood"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-13T20:11:19Z","date_published":"2014-12-13T20:11:19Z","updated_at":"2026-07-22T22:25:57Z","subjects":["Chemistry, Inorganic"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8127640"],"render_values":[{"text":"(UMI)AAI8127640","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/67280","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Mccullen, William Lynwood"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-13T20:11:19Z","10000-01-01","1981"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry, Inorganic"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/67280","(UMI)AAI8127640"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The classical and quantum mechanical descriptions of nuclear quadrupole resonance (nqr) are reviewed. Fundamental principles of nuclear spin thermodynamics are introduced to explain double resonance via level crossing (drlc), the experimental technique employed to detect ('14)N nqr resonances.","Two double irradiation techniques are described which enhance spectral intensity and resolution. The first technique, "sensitivity enhancement", which was previously reported in the literature, affords a means of selectively enhancing the intensity of inherently weak (nu)(,-)resonances. The second technique, "pre-saturation", provides a method of resolving two intense, overlapping resonances which arise from different nitrogen sites.","A simple model is developed from non-degenerate perturbation theory to describe the 'solid effect'. The model qualitatively accounts for the characteristic line shapes associated with various types of nitrogen sites and the unresolved fine structure associated with resonances arising from the nitrogens of primary amine groups.","Finally, the ('14)N nqr parameters for a number of pyrimidines and purines are reported. A Townes-Dailey model is presented which relates the nqr parameters with the relative nitrogen atom hybrid orbital populations for the sp('2) orbitals of the cyclic amino, cyclic imino, exocyclic amino nitrogen sites. The population trends are discussed in terms of intramolecular resonance and inductive effects, and intermolecular bonding interactions. The ('14)N nqr spectra were obtained for several diamagnetic metal-pyrimidine compounds. With the exception of dichlorouracilcadmium, unambiguous assignment of these spectra was not possible.","Made available in DSpace on 2014-12-13T20:11:19Z (GMT). No. of bitstreams: 1 8127640.pdf: 8496299 bytes, checksum: d05a2b324d3985c35c9c96e24b263512 (MD5) Previous issue date: 1981","Embargo set by: Seth Robbins for item 67458 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","316 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981."]},{"key":"dc:title","label":"Title","values":["Nitrogen-14 Nuclear Quadrupole Resonance Studies of Pyrimidine and Purine Derivatives"]}]}],"canonical_facts":{"dc:creator":["Mccullen, William Lynwood"],"dc:date":["2014-12-13T20:11:19Z","10000-01-01","1981"],"dc:description":["The classical and quantum mechanical descriptions of nuclear quadrupole resonance (nqr) are reviewed. Fundamental principles of nuclear spin thermodynamics are introduced to explain double resonance via level crossing (drlc), the experimental technique employed to detect ('14)N nqr resonances.","Two double irradiation techniques are described which enhance spectral intensity and resolution. The first technique, "sensitivity enhancement", which was previously reported in the literature, affords a means of selectively enhancing the intensity of inherently weak (nu)(,-)resonances. The second technique, "pre-saturation", provides a method of resolving two intense, overlapping resonances which arise from different nitrogen sites.","A simple model is developed from non-degenerate perturbation theory to describe the 'solid effect'. The model qualitatively accounts for the characteristic line shapes associated with various types of nitrogen sites and the unresolved fine structure associated with resonances arising from the nitrogens of primary amine groups.","Finally, the ('14)N nqr parameters for a number of pyrimidines and purines are reported. A Townes-Dailey model is presented which relates the nqr parameters with the relative nitrogen atom hybrid orbital populations for the sp('2) orbitals of the cyclic amino, cyclic imino, exocyclic amino nitrogen sites. The population trends are discussed in terms of intramolecular resonance and inductive effects, and intermolecular bonding interactions. The ('14)N nqr spectra were obtained for several diamagnetic metal-pyrimidine compounds. With the exception of dichlorouracilcadmium, unambiguous assignment of these spectra was not possible.","Made available in DSpace on 2014-12-13T20:11:19Z (GMT). No. of bitstreams: 1 8127640.pdf: 8496299 bytes, checksum: d05a2b324d3985c35c9c96e24b263512 (MD5) Previous issue date: 1981","Embargo set by: Seth Robbins for item 67458 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","316 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981."],"dc:identifier":["http://hdl.handle.net/2142/67280","(UMI)AAI8127640"],"dc:language":["eng"],"dc:subject":["Chemistry, Inorganic"],"dc:title":["Nitrogen-14 Nuclear Quadrupole Resonance Studies of Pyrimidine and Purine Derivatives"],"dc:type":["text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:57Z"}