{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23159"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23159","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Environmental effects on the rate of intramolecular electron transfer in trinuclear mixed-valence transition metal carboxylate complexes in the solid state","abstract":"In a series of the isostructural (R32 space group) mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) $\\cdot$ S complexes, where (4-Me-Py) is 4-methylpyridine and S is a solvate molecule, we have found that systematic changes of solvate molecules have a pronounced impact on the phase transitions at which a given complex valence detraps. This sensitivity is a reflection of the fact that the lowest energy electronic states of Fe$\\sb3$O complexes are vibronic and as a result these complexes are very sensitive to their environment. It is also found that the CHCl$\\sb3$ solvate complex exhibits a very abrupt phase transition at low temperature (95K) and the CH$\\sb3$CCl$\\sb3$ solvate complex exhibits a phase transition at 125K. $\\sp{57}$Fe Mossbauer spectra of this CHCl$\\sb3$ solvate complex show that this complex valence-detraps at $\\sim$95K. However, the complex with the less symmetric CH$\\sb3$CHCl$\\sb2$ solvate molecule becomes valence-detrapped at $\\sim$45 degrees higher than for the CH$\\sb3$CCl$\\sb3$ complex and $\\sim$75 degrees higher than for the CHCl$\\sb3$ complex. Changing the solvate molecules may lead to changes in the intermolecular interactions propagated via the pyridine-pyridine overlaps between neighboring Fe$\\sb3$O molecules. The introduction of the bulky solvate (CH$\\sb3$CCl$\\sb3$) and less symmetric solvate (CH$\\sb3$CHCl$\\sb2$) gives rise to less intermolecular interactions between neighboring Fe$\\sb3$O molecules and, consequently, gives higher transition temperature than that of the C$\\sb3$ symmetry CHCl$\\sb3$ solvate. In fact, the results of CNDO/2 molecular orbital calculations show that an important factor is the intermolecular interactions between the 4-Me-Py$\\cdots$4-Me-Py ligands for controlling the intramolecular electron transfer rate in addition to the onset of solvate molecules dynamic motion.","abstract_html":"In a series of the isostructural (R32 space group) mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) $\\cdot$ S complexes, where (4-Me-Py) is 4-methylpyridine and S is a solvate molecule, we have found that systematic changes of solvate molecules have a pronounced impact on the phase transitions at which a given complex valence detraps. This sensitivity is a reflection of the fact that the lowest energy electronic states of Fe$\\sb3$O complexes are vibronic and as a result these complexes are very sensitive to their environment. It is also found that the CHCl$\\sb3$ solvate complex exhibits a very abrupt phase transition at low temperature (95K) and the CH$\\sb3$CCl$\\sb3$ solvate complex exhibits a phase transition at 125K. $\\sp{57}$Fe Mossbauer spectra of this CHCl$\\sb3$ solvate complex show that this complex valence-detraps at $\\sim$95K. However, the complex with the less symmetric CH$\\sb3$CHCl$\\sb2$ solvate molecule becomes valence-detrapped at $\\sim$45 degrees higher than for the CH$\\sb3$CCl$\\sb3$ complex and $\\sim$75 degrees higher than for the CHCl$\\sb3$ complex. Changing the solvate molecules may lead to changes in the intermolecular interactions propagated via the pyridine-pyridine overlaps between neighboring Fe$\\sb3$O molecules. The introduction of the bulky solvate (CH$\\sb3$CCl$\\sb3$) and less symmetric solvate (CH$\\sb3$CHCl$\\sb2$) gives rise to less intermolecular interactions between neighboring Fe$\\sb3$O molecules and, consequently, gives higher transition temperature than that of the C$\\sb3$ symmetry CHCl$\\sb3$ solvate. In fact, the results of CNDO/2 molecular orbital calculations show that an important factor is the intermolecular interactions between the 4-Me-Py$\\cdots$4-Me-Py ligands for controlling the intramolecular electron transfer rate in addition to the onset of solvate molecules dynamic motion.","abstract_has_math":true,"creators":["Jang, Ho Gyeom"],"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":2011,"date_issued":"2011-05-07T14:04:16Z","date_published":"2011-05-07T14:04:16Z","updated_at":"2026-07-22T22:25:21Z","subjects":["Chemistry, Inorganic"],"languages":["eng"],"rights":["Copyright 1989 Jang, Ho Gyeom"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9010899","(UMI)AAI9010899"],"render_values":[{"text":"AAI9010899","href":null,"code":true},{"text":"(UMI)AAI9010899","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23159","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Jang, Ho Gyeom"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T14:04:16Z","10000-01-01","1989"]},{"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"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1989 Jang, Ho Gyeom"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9010899","(UMI)AAI9010899","http://hdl.handle.net/2142/23159"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["In a series of the isostructural (R32 space group) mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) $\\cdot$ S complexes, where (4-Me-Py) is 4-methylpyridine and S is a solvate molecule, we have found that systematic changes of solvate molecules have a pronounced impact on the phase transitions at which a given complex valence detraps. This sensitivity is a reflection of the fact that the lowest energy electronic states of Fe$\\sb3$O complexes are vibronic and as a result these complexes are very sensitive to their environment. It is also found that the CHCl$\\sb3$ solvate complex exhibits a very abrupt phase transition at low temperature (95K) and the CH$\\sb3$CCl$\\sb3$ solvate complex exhibits a phase transition at 125K. $\\sp{57}$Fe Mossbauer spectra of this CHCl$\\sb3$ solvate complex show that this complex valence-detraps at $\\sim$95K. However, the complex with the less symmetric CH$\\sb3$CHCl$\\sb2$ solvate molecule becomes valence-detrapped at $\\sim$45 degrees higher than for the CH$\\sb3$CCl$\\sb3$ complex and $\\sim$75 degrees higher than for the CHCl$\\sb3$ complex. Changing the solvate molecules may lead to changes in the intermolecular interactions propagated via the pyridine-pyridine overlaps between neighboring Fe$\\sb3$O molecules. The introduction of the bulky solvate (CH$\\sb3$CCl$\\sb3$) and less symmetric solvate (CH$\\sb3$CHCl$\\sb2$) gives rise to less intermolecular interactions between neighboring Fe$\\sb3$O molecules and, consequently, gives higher transition temperature than that of the C$\\sb3$ symmetry CHCl$\\sb3$ solvate. In fact, the results of CNDO/2 molecular orbital calculations show that an important factor is the intermolecular interactions between the 4-Me-Py$\\cdots$4-Me-Py ligands for controlling the intramolecular electron transfer rate in addition to the onset of solvate molecules dynamic motion.","Interestingly, solid-state $\\sp2$H NMR studies of (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(Py)$\\sb3$) (CDCl$\\sb3$) and (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) (CDCl$\\sb3$) show that the C$\\sb3$-symmetry CHCl$\\sb3$ molecule synchronously moves with the changes of the vibronic coordinates in neighboring Fe$\\sb3$O molecules in the lattice. Thus, we can suggest that another important factor in controlling the rate of electron transfer may be the van der Waals interactions between a solvate molecule and neighboring Fe$\\sb3$O complexes. This van der Waals interactions may be large enough to modify the ground state potential-energy surface for a Fe$\\sb3$O complex to affect the rate at which such a complex can tunnel from one vibronic minimum to another.","Finally, we have discovered the first trinuclear iron acetate complex (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(3-Et-Py)$\\sb3$) (C$\\sb7$H$\\sb8$)$\\sb{0.5}$ which exhibits an isosceles Fe$\\sb3$O triangular plane at room temperature, i.e., completely valence-trapped on the X-ray time scale. However, the analogous mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(3-Et-Py)$\\sb3$) (CH$\\sb3$CCl$\\sb3$) shows a valence detrapping phenomenon due to the adoption of a symmetric solvate molecule configuration. Thus, one really can turn on and off the intramolecular electron transfer in the mixed-valence complexes by controlling the lattice environments.","Made available in DSpace on 2011-05-07T14:04:16Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9010899.pdf: 12546397 bytes, checksum: d7ba644ab5b585aaedf7d5bb57b4b5d8 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:02:35Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:29:46-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Environmental effects on the rate of intramolecular electron transfer in trinuclear mixed-valence transition metal carboxylate complexes in the solid state"]}]}],"canonical_facts":{"dc:creator":["Jang, Ho Gyeom"],"dc:date":["2011-05-07T14:04:16Z","10000-01-01","1989"],"dc:description":["In a series of the isostructural (R32 space group) mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) $\\cdot$ S complexes, where (4-Me-Py) is 4-methylpyridine and S is a solvate molecule, we have found that systematic changes of solvate molecules have a pronounced impact on the phase transitions at which a given complex valence detraps. This sensitivity is a reflection of the fact that the lowest energy electronic states of Fe$\\sb3$O complexes are vibronic and as a result these complexes are very sensitive to their environment. It is also found that the CHCl$\\sb3$ solvate complex exhibits a very abrupt phase transition at low temperature (95K) and the CH$\\sb3$CCl$\\sb3$ solvate complex exhibits a phase transition at 125K. $\\sp{57}$Fe Mossbauer spectra of this CHCl$\\sb3$ solvate complex show that this complex valence-detraps at $\\sim$95K. However, the complex with the less symmetric CH$\\sb3$CHCl$\\sb2$ solvate molecule becomes valence-detrapped at $\\sim$45 degrees higher than for the CH$\\sb3$CCl$\\sb3$ complex and $\\sim$75 degrees higher than for the CHCl$\\sb3$ complex. Changing the solvate molecules may lead to changes in the intermolecular interactions propagated via the pyridine-pyridine overlaps between neighboring Fe$\\sb3$O molecules. The introduction of the bulky solvate (CH$\\sb3$CCl$\\sb3$) and less symmetric solvate (CH$\\sb3$CHCl$\\sb2$) gives rise to less intermolecular interactions between neighboring Fe$\\sb3$O molecules and, consequently, gives higher transition temperature than that of the C$\\sb3$ symmetry CHCl$\\sb3$ solvate. In fact, the results of CNDO/2 molecular orbital calculations show that an important factor is the intermolecular interactions between the 4-Me-Py$\\cdots$4-Me-Py ligands for controlling the intramolecular electron transfer rate in addition to the onset of solvate molecules dynamic motion.","Interestingly, solid-state $\\sp2$H NMR studies of (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(Py)$\\sb3$) (CDCl$\\sb3$) and (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(4-Me-Py)$\\sb3$) (CDCl$\\sb3$) show that the C$\\sb3$-symmetry CHCl$\\sb3$ molecule synchronously moves with the changes of the vibronic coordinates in neighboring Fe$\\sb3$O molecules in the lattice. Thus, we can suggest that another important factor in controlling the rate of electron transfer may be the van der Waals interactions between a solvate molecule and neighboring Fe$\\sb3$O complexes. This van der Waals interactions may be large enough to modify the ground state potential-energy surface for a Fe$\\sb3$O complex to affect the rate at which such a complex can tunnel from one vibronic minimum to another.","Finally, we have discovered the first trinuclear iron acetate complex (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(3-Et-Py)$\\sb3$) (C$\\sb7$H$\\sb8$)$\\sb{0.5}$ which exhibits an isosceles Fe$\\sb3$O triangular plane at room temperature, i.e., completely valence-trapped on the X-ray time scale. However, the analogous mixed-valence (Fe$\\sb3$O(O$\\sb2$CCH$\\sb3$)$\\sb6$(3-Et-Py)$\\sb3$) (CH$\\sb3$CCl$\\sb3$) shows a valence detrapping phenomenon due to the adoption of a symmetric solvate molecule configuration. Thus, one really can turn on and off the intramolecular electron transfer in the mixed-valence complexes by controlling the lattice environments.","Made available in DSpace on 2011-05-07T14:04:16Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9010899.pdf: 12546397 bytes, checksum: d7ba644ab5b585aaedf7d5bb57b4b5d8 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:02:35Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:29:46-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9010899","(UMI)AAI9010899","http://hdl.handle.net/2142/23159"],"dc:language":["eng"],"dc:rights":["Copyright 1989 Jang, Ho Gyeom"],"dc:subject":["Chemistry, Inorganic"],"dc:title":["Environmental effects on the rate of intramolecular electron transfer in trinuclear mixed-valence transition metal carboxylate complexes in the solid state"],"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":"2026-07-22T22:25:21Z"}