{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/84312"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/84312","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Steric and Electronic Effects Induced by Ancillary Ligand Substitutions on Cyclopentadienyl Osmium Complexes","abstract":"To understand these variances, the molecular geometries of several osmium(II) and osmium(IV) complexes were investigated. (C5H5)Os(dmpm)Br reacts with NaOMe in refluxing methanol to afford the monohydride compound (C5H5)Os(dmpm)H, which can be protonated with HBF 4·Et2O to afford [(C5H5)Os(dmpm)H 2][BF4]. Comparison of the X-ray crystal structures of (C 5H5)Os(dmpm)H and (C5Me5)Os(dmpm)H revealed no significant differences. In contrast, comparison of the structures of [(C5H5)Os(dmpm)H2+] and [(C5Me5)Os(dmpm)H2+] showed that C5Me5 is more sterically demanding than C 5H5, as evidenced by the 7--8° decrease in the dihedral angle between the P-Os-P and C5 ring planes for the C5H 5 analogue, suggesting that movement of the phosphine toward the less sterically bulky C5 ring may lead to greater distances between cisoid ligands, effectively raising the barrier to hydrogen exchange in the dihydride and the methyl hydride systems.","abstract_html":"To understand these variances, the molecular geometries of several osmium(II) and osmium(IV) complexes were investigated. (C5H5)Os(dmpm)Br reacts with NaOMe in refluxing methanol to afford the monohydride compound (C5H5)Os(dmpm)H, which can be protonated with HBF 4·Et2O to afford [(C5H5)Os(dmpm)H 2][BF4]. Comparison of the X-ray crystal structures of (C 5H5)Os(dmpm)H and (C5Me5)Os(dmpm)H revealed no significant differences. In contrast, comparison of the structures of [(C5H5)Os(dmpm)H2+] and [(C5Me5)Os(dmpm)H2+] showed that C5Me5 is more sterically demanding than C 5H5, as evidenced by the 7--8° decrease in the dihedral angle between the P-Os-P and C5 ring planes for the C5H 5 analogue, suggesting that movement of the phosphine toward the less sterically bulky C5 ring may lead to greater distances between cisoid ligands, effectively raising the barrier to hydrogen exchange in the dihydride and the methyl hydride systems.","abstract_has_math":false,"creators":["Jew, Richard L."],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Girolami, Gregory S."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:13:54Z","date_published":"2015-09-25T22:13:54Z","updated_at":"2026-07-22T22:26:23Z","subjects":["Chemistry, Inorganic"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI3337810"],"render_values":[{"text":"(MiAaPQ)AAI3337810","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/84312","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Girolami, Gregory S."]},{"key":"dc:creator","label":"Author","values":["Jew, Richard L."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:13:54Z","10000-01-01","2008"]},{"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/2142/84312","(MiAaPQ)AAI3337810"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["To understand these variances, the molecular geometries of several osmium(II) and osmium(IV) complexes were investigated. (C5H5)Os(dmpm)Br reacts with NaOMe in refluxing methanol to afford the monohydride compound (C5H5)Os(dmpm)H, which can be protonated with HBF 4·Et2O to afford [(C5H5)Os(dmpm)H 2][BF4]. Comparison of the X-ray crystal structures of (C 5H5)Os(dmpm)H and (C5Me5)Os(dmpm)H revealed no significant differences. In contrast, comparison of the structures of [(C5H5)Os(dmpm)H2+] and [(C5Me5)Os(dmpm)H2+] showed that C5Me5 is more sterically demanding than C 5H5, as evidenced by the 7--8° decrease in the dihedral angle between the P-Os-P and C5 ring planes for the C5H 5 analogue, suggesting that movement of the phosphine toward the less sterically bulky C5 ring may lead to greater distances between cisoid ligands, effectively raising the barrier to hydrogen exchange in the dihydride and the methyl hydride systems.","Made available in DSpace on 2015-09-25T22:13:54Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3337810.pdf: 1843547 bytes, checksum: 09f9c70b4a986e4cd0ee9a4e6308a6b6 (MD5) Previous issue date: 2008","Embargo set by: Seth Robbins for item 85593 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","140 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008."]},{"key":"dc:title","label":"Title","values":["Steric and Electronic Effects Induced by Ancillary Ligand Substitutions on Cyclopentadienyl Osmium Complexes"]}]}],"canonical_facts":{"dc:contributor":["Girolami, Gregory S."],"dc:creator":["Jew, Richard L."],"dc:date":["2015-09-25T22:13:54Z","10000-01-01","2008"],"dc:description":["To understand these variances, the molecular geometries of several osmium(II) and osmium(IV) complexes were investigated. (C5H5)Os(dmpm)Br reacts with NaOMe in refluxing methanol to afford the monohydride compound (C5H5)Os(dmpm)H, which can be protonated with HBF 4·Et2O to afford [(C5H5)Os(dmpm)H 2][BF4]. Comparison of the X-ray crystal structures of (C 5H5)Os(dmpm)H and (C5Me5)Os(dmpm)H revealed no significant differences. In contrast, comparison of the structures of [(C5H5)Os(dmpm)H2+] and [(C5Me5)Os(dmpm)H2+] showed that C5Me5 is more sterically demanding than C 5H5, as evidenced by the 7--8° decrease in the dihedral angle between the P-Os-P and C5 ring planes for the C5H 5 analogue, suggesting that movement of the phosphine toward the less sterically bulky C5 ring may lead to greater distances between cisoid ligands, effectively raising the barrier to hydrogen exchange in the dihydride and the methyl hydride systems.","Made available in DSpace on 2015-09-25T22:13:54Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 3337810.pdf: 1843547 bytes, checksum: 09f9c70b4a986e4cd0ee9a4e6308a6b6 (MD5) Previous issue date: 2008","Embargo set by: Seth Robbins for item 85593 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","140 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008."],"dc:identifier":["http://hdl.handle.net/2142/84312","(MiAaPQ)AAI3337810"],"dc:language":["eng"],"dc:subject":["Chemistry, Inorganic"],"dc:title":["Steric and Electronic Effects Induced by Ancillary Ligand Substitutions on Cyclopentadienyl Osmium Complexes"],"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":"2026-07-22T22:26:23Z"}