{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/70243"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/70243","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Kinetics and Mechanism of the Reaction of 4,4'-Dimethoxythio Benzophenone With Grignard Reagents","abstract":"The mechanism of the reaction of 4,4'-dimethoxythiobenzophenone with Grignard reagents was investigated kinetically by stopped-flow spectroscopy. The reaction of this thioketone with methylmagnesium bromide in ether at 25.0(DEGREES)C was found to be first order in thioketone and first order in Grignard, with a second-order rate constant of 0.047 (+OR-) 0.002 s('-1)M('-1). The mechanism proposed to account for the products of the reaction involves slow thiophilic addition of Grignard to thioketone, followed by fast carbophilic addition of the intermediate thus formed to a second molecule of thioketone. The resulting dimeric intermediate produces the sulfide corresponding to thiophilic addition and regenerates thioketone upon aqueous quench at short reaction times. It proceeds to stable dimeric products at very long reaction times. The kinetics of the reaction of 4,4'-dimethoxythiobenzophenone with ethylmagnesium bromide in tetrahydrofuran at 50.0(DEGREES)C are complex, showing an initial fast reaction, followed by one or more successively slower reactions, depending on the wavelength of observation. The reaction proceeds cleanly to the sulfide resulting from thiophilic addition within five minutes. Further investigation is required before a detailed mechanism can be proposed for this reaction.","abstract_html":"The mechanism of the reaction of 4,4'-dimethoxythiobenzophenone with Grignard reagents was investigated kinetically by stopped-flow spectroscopy. The reaction of this thioketone with methylmagnesium bromide in ether at 25.0(DEGREES)C was found to be first order in thioketone and first order in Grignard, with a second-order rate constant of 0.047 (+OR-) 0.002 s('-1)M('-1). The mechanism proposed to account for the products of the reaction involves slow thiophilic addition of Grignard to thioketone, followed by fast carbophilic addition of the intermediate thus formed to a second molecule of thioketone. The resulting dimeric intermediate produces the sulfide corresponding to thiophilic addition and regenerates thioketone upon aqueous quench at short reaction times. It proceeds to stable dimeric products at very long reaction times. The kinetics of the reaction of 4,4'-dimethoxythiobenzophenone with ethylmagnesium bromide in tetrahydrofuran at 50.0(DEGREES)C are complex, showing an initial fast reaction, followed by one or more successively slower reactions, depending on the wavelength of observation. The reaction proceeds cleanly to the sulfide resulting from thiophilic addition within five minutes. Further investigation is required before a detailed mechanism can be proposed for this reaction.","abstract_has_math":false,"creators":["Fradenburgh, Sharon Ann"],"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":"2014-12-15T23:18:07Z","date_published":"2014-12-15T23:18:07Z","updated_at":"2026-07-22T22:26:02Z","subjects":["Chemistry, Organic"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8409924"],"render_values":[{"text":"(UMI)AAI8409924","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/70243","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Fradenburgh, Sharon Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-15T23:18:07Z","10000-01-01","1983"]},{"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, Organic"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/70243","(UMI)AAI8409924"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The mechanism of the reaction of 4,4'-dimethoxythiobenzophenone with Grignard reagents was investigated kinetically by stopped-flow spectroscopy. The reaction of this thioketone with methylmagnesium bromide in ether at 25.0(DEGREES)C was found to be first order in thioketone and first order in Grignard, with a second-order rate constant of 0.047 (+OR-) 0.002 s('-1)M('-1). The mechanism proposed to account for the products of the reaction involves slow thiophilic addition of Grignard to thioketone, followed by fast carbophilic addition of the intermediate thus formed to a second molecule of thioketone. The resulting dimeric intermediate produces the sulfide corresponding to thiophilic addition and regenerates thioketone upon aqueous quench at short reaction times. It proceeds to stable dimeric products at very long reaction times. The kinetics of the reaction of 4,4'-dimethoxythiobenzophenone with ethylmagnesium bromide in tetrahydrofuran at 50.0(DEGREES)C are complex, showing an initial fast reaction, followed by one or more successively slower reactions, depending on the wavelength of observation. The reaction proceeds cleanly to the sulfide resulting from thiophilic addition within five minutes. Further investigation is required before a detailed mechanism can be proposed for this reaction.","Made available in DSpace on 2014-12-15T23:18:07Z (GMT). No. of bitstreams: 1 8409924.pdf: 4040224 bytes, checksum: 600aa62eea9c6c555afc7f53fa140dac (MD5) Previous issue date: 1983","Embargo set by: Seth Robbins for item 70409 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","132 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983."]},{"key":"dc:title","label":"Title","values":["Kinetics and Mechanism of the Reaction of 4,4'-Dimethoxythio Benzophenone With Grignard Reagents"]}]}],"canonical_facts":{"dc:creator":["Fradenburgh, Sharon Ann"],"dc:date":["2014-12-15T23:18:07Z","10000-01-01","1983"],"dc:description":["The mechanism of the reaction of 4,4'-dimethoxythiobenzophenone with Grignard reagents was investigated kinetically by stopped-flow spectroscopy. The reaction of this thioketone with methylmagnesium bromide in ether at 25.0(DEGREES)C was found to be first order in thioketone and first order in Grignard, with a second-order rate constant of 0.047 (+OR-) 0.002 s('-1)M('-1). The mechanism proposed to account for the products of the reaction involves slow thiophilic addition of Grignard to thioketone, followed by fast carbophilic addition of the intermediate thus formed to a second molecule of thioketone. The resulting dimeric intermediate produces the sulfide corresponding to thiophilic addition and regenerates thioketone upon aqueous quench at short reaction times. It proceeds to stable dimeric products at very long reaction times. The kinetics of the reaction of 4,4'-dimethoxythiobenzophenone with ethylmagnesium bromide in tetrahydrofuran at 50.0(DEGREES)C are complex, showing an initial fast reaction, followed by one or more successively slower reactions, depending on the wavelength of observation. The reaction proceeds cleanly to the sulfide resulting from thiophilic addition within five minutes. Further investigation is required before a detailed mechanism can be proposed for this reaction.","Made available in DSpace on 2014-12-15T23:18:07Z (GMT). No. of bitstreams: 1 8409924.pdf: 4040224 bytes, checksum: 600aa62eea9c6c555afc7f53fa140dac (MD5) Previous issue date: 1983","Embargo set by: Seth Robbins for item 70409 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","132 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983."],"dc:identifier":["http://hdl.handle.net/2142/70243","(UMI)AAI8409924"],"dc:subject":["Chemistry, Organic"],"dc:title":["Kinetics and Mechanism of the Reaction of 4,4'-Dimethoxythio Benzophenone With Grignard Reagents"],"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":"2026-07-22T22:26:02Z"}