{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/72275"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/72275","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The Chemistry of Aroyl Azides in Piperidine- and Steroid-Separated Bichromophoric System: Photoinduced Long-Distance Intramolecular Electron Transfer Reactions","abstract":"The photochemistry and photophysics of piperidine- and steroid- separated bichromophoric systems containing an aroyl azide as the electron acceptor and secondary aromatic amines as the electron donors was examined. We report the first example of unique photochemical reactivity associated with through-bond electron transfer in these bichromophores. Light absorbed by the aroyl azide acceptor chromophore of these compounds gives isocyanate by the photo-Curtius rearrangement and nitrene by loss of nitrogen. Light absorbed by the aryl amine donor chromophores initiates a through-bond electron-transfer reaction to form high energy, charge-separated intermediate states. The aryl amine radical cations were detected by pulsed laser spectroscopy and the highly reactive aroyl azide radical anions were identified by the results of steady-state photolysis. In acetonitrile and in methyl alcohol solution, the photoexcited aryl amine converts the azide to a primary amide. The mechanism of this reaction is thought to involve long-range electron transfer to form first the azide and then nitrene radical anion intermediates. Similar irradiation of the bichromophoric system in cyclohexane solution converts the azide to a secondary amide. In this case the reaction seems to proceed through a nitrene intermediate. The photolysis efficiency of the azide is solvent-independent, and is not affected significantly by the orientation of amine group (the cis or trans). Intramolecular electron-transfer from the singlet and triplet excited state of the donor chromophore plays an important role and triplet-triplet energy transfer mechanism may also be involved in this chemistry. The mechanism for the reaction is supported by fluorescence quenching and laser flash photolysis experiments and by quenching and trapping studies.","abstract_html":"The photochemistry and photophysics of piperidine- and steroid- separated bichromophoric systems containing an aroyl azide as the electron acceptor and secondary aromatic amines as the electron donors was examined. We report the first example of unique photochemical reactivity associated with through-bond electron transfer in these bichromophores. Light absorbed by the aroyl azide acceptor chromophore of these compounds gives isocyanate by the photo-Curtius rearrangement and nitrene by loss of nitrogen. Light absorbed by the aryl amine donor chromophores initiates a through-bond electron-transfer reaction to form high energy, charge-separated intermediate states. The aryl amine radical cations were detected by pulsed laser spectroscopy and the highly reactive aroyl azide radical anions were identified by the results of steady-state photolysis. In acetonitrile and in methyl alcohol solution, the photoexcited aryl amine converts the azide to a primary amide. The mechanism of this reaction is thought to involve long-range electron transfer to form first the azide and then nitrene radical anion intermediates. Similar irradiation of the bichromophoric system in cyclohexane solution converts the azide to a secondary amide. In this case the reaction seems to proceed through a nitrene intermediate. The photolysis efficiency of the azide is solvent-independent, and is not affected significantly by the orientation of amine group (the cis or trans). Intramolecular electron-transfer from the singlet and triplet excited state of the donor chromophore plays an important role and triplet-triplet energy transfer mechanism may also be involved in this chemistry. The mechanism for the reaction is supported by fluorescence quenching and laser flash photolysis experiments and by quenching and trapping studies.","abstract_has_math":false,"creators":["Zhu, Yong"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Schuster, Gary B."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-17T21:29:03Z","date_published":"2014-12-17T21:29:03Z","updated_at":"2026-07-22T22:26:06Z","subjects":["Chemistry, Inorganic","Chemistry, Organic","Chemistry, Physical"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI9305750"],"render_values":[{"text":"(UMI)AAI9305750","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/72275","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Schuster, Gary B."]},{"key":"dc:creator","label":"Author","values":["Zhu, Yong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-17T21:29:03Z","10000-01-01","1992"]},{"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","Chemistry, Organic","Chemistry, Physical"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/72275","(UMI)AAI9305750"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The photochemistry and photophysics of piperidine- and steroid- separated bichromophoric systems containing an aroyl azide as the electron acceptor and secondary aromatic amines as the electron donors was examined. We report the first example of unique photochemical reactivity associated with through-bond electron transfer in these bichromophores. Light absorbed by the aroyl azide acceptor chromophore of these compounds gives isocyanate by the photo-Curtius rearrangement and nitrene by loss of nitrogen. Light absorbed by the aryl amine donor chromophores initiates a through-bond electron-transfer reaction to form high energy, charge-separated intermediate states. The aryl amine radical cations were detected by pulsed laser spectroscopy and the highly reactive aroyl azide radical anions were identified by the results of steady-state photolysis. In acetonitrile and in methyl alcohol solution, the photoexcited aryl amine converts the azide to a primary amide. The mechanism of this reaction is thought to involve long-range electron transfer to form first the azide and then nitrene radical anion intermediates. Similar irradiation of the bichromophoric system in cyclohexane solution converts the azide to a secondary amide. In this case the reaction seems to proceed through a nitrene intermediate. The photolysis efficiency of the azide is solvent-independent, and is not affected significantly by the orientation of amine group (the cis or trans). Intramolecular electron-transfer from the singlet and triplet excited state of the donor chromophore plays an important role and triplet-triplet energy transfer mechanism may also be involved in this chemistry. The mechanism for the reaction is supported by fluorescence quenching and laser flash photolysis experiments and by quenching and trapping studies.","Made available in DSpace on 2014-12-17T21:29:03Z (GMT). No. of bitstreams: 1 9305750.pdf: 8244926 bytes, checksum: bbb9fbf8769a958c0bd0025f6669bfe1 (MD5) Previous issue date: 1992","Embargo set by: Seth Robbins for item 72443 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","163 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1992."]},{"key":"dc:title","label":"Title","values":["The Chemistry of Aroyl Azides in Piperidine- and Steroid-Separated Bichromophoric System: Photoinduced Long-Distance Intramolecular Electron Transfer Reactions"]}]}],"canonical_facts":{"dc:contributor":["Schuster, Gary B."],"dc:creator":["Zhu, Yong"],"dc:date":["2014-12-17T21:29:03Z","10000-01-01","1992"],"dc:description":["The photochemistry and photophysics of piperidine- and steroid- separated bichromophoric systems containing an aroyl azide as the electron acceptor and secondary aromatic amines as the electron donors was examined. We report the first example of unique photochemical reactivity associated with through-bond electron transfer in these bichromophores. Light absorbed by the aroyl azide acceptor chromophore of these compounds gives isocyanate by the photo-Curtius rearrangement and nitrene by loss of nitrogen. Light absorbed by the aryl amine donor chromophores initiates a through-bond electron-transfer reaction to form high energy, charge-separated intermediate states. The aryl amine radical cations were detected by pulsed laser spectroscopy and the highly reactive aroyl azide radical anions were identified by the results of steady-state photolysis. In acetonitrile and in methyl alcohol solution, the photoexcited aryl amine converts the azide to a primary amide. The mechanism of this reaction is thought to involve long-range electron transfer to form first the azide and then nitrene radical anion intermediates. Similar irradiation of the bichromophoric system in cyclohexane solution converts the azide to a secondary amide. In this case the reaction seems to proceed through a nitrene intermediate. The photolysis efficiency of the azide is solvent-independent, and is not affected significantly by the orientation of amine group (the cis or trans). Intramolecular electron-transfer from the singlet and triplet excited state of the donor chromophore plays an important role and triplet-triplet energy transfer mechanism may also be involved in this chemistry. The mechanism for the reaction is supported by fluorescence quenching and laser flash photolysis experiments and by quenching and trapping studies.","Made available in DSpace on 2014-12-17T21:29:03Z (GMT). No. of bitstreams: 1 9305750.pdf: 8244926 bytes, checksum: bbb9fbf8769a958c0bd0025f6669bfe1 (MD5) Previous issue date: 1992","Embargo set by: Seth Robbins for item 72443 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","163 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1992."],"dc:identifier":["http://hdl.handle.net/2142/72275","(UMI)AAI9305750"],"dc:subject":["Chemistry, Inorganic","Chemistry, Organic","Chemistry, Physical"],"dc:title":["The Chemistry of Aroyl Azides in Piperidine- and Steroid-Separated Bichromophoric System: Photoinduced Long-Distance Intramolecular Electron Transfer Reactions"],"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":"2026-07-22T22:26:06Z"}