{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/70382"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/70382","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Dynamics and Mechanism of Spin-State Interconversion in Iron Spin-Crossover Complexes","abstract":"The work described in this dissertation is directed at a better understanding of the dynamics and mechanism of the so-called spin-crossover phenomenon. Several iron spin-crossover systems, including ferrous and ferric complexes, are investigated with various spectroscopic techniques and single-crystal X-ray structure determination.","abstract_html":"The work described in this dissertation is directed at a better understanding of the dynamics and mechanism of the so-called spin-crossover phenomenon. Several iron spin-crossover systems, including ferrous and ferric complexes, are investigated with various spectroscopic techniques and single-crystal X-ray structure determination.","abstract_has_math":false,"creators":["Xie, Chuan-Liang"],"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":"2014-12-15T23:19:03Z","date_published":"2014-12-15T23:19:03Z","updated_at":"2026-07-22T22:26:02Z","subjects":["Chemistry, Inorganic"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8721791"],"render_values":[{"text":"(UMI)AAI8721791","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/70382","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Xie, Chuan-Liang"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-15T23:19:03Z","10000-01-01","1987"]},{"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":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/70382","(UMI)AAI8721791"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The work described in this dissertation is directed at a better understanding of the dynamics and mechanism of the so-called spin-crossover phenomenon. Several iron spin-crossover systems, including ferrous and ferric complexes, are investigated with various spectroscopic techniques and single-crystal X-ray structure determination.","In the first part the cooperativity of ferric spin-crossover complexes in the solid state and the influence of lattice solvation and metal dilution upon these properties is studied. The complex Fe(3-OMeSalAPA)$\\sb 2$ClO$\\sb 4$, where 3-OMeSalAPA is the Schiff base ligand condensed from one mole of 3-methoxylsalicylaldehyde with N-aminopropylaziridine, and its various halobenzene solvated forms were studied with $\\sp{57}$Fe Mossbauer and EPR spectroscopies, as well as magnetic susceptibility, DSC, single-crystal structure determination and variable temperature XRD techniques. It has been found from the experimental results that the ferric complex Fe(3-OMeSalAPA)$\\sb 2$ClO$\\sb 4$ and its solvated forms are spin-crossover systems of the gradual type.","In the second part of this thesis, an investigation of the correlation between the onset of solvate molecule dynamics and the spin-crossover phase transition is investigated. The complex Fe(dppen)$\\sb 2$Cl$\\sb 2$ with lattice solvate molecules of CH$\\sb 3$COCH$\\sb 3$, CD$\\sb 3$COCD$\\sb 3$, CH$\\sb 2$Cl$\\sb 2$, CD$\\sb 2$Cl$\\sb 2$, CHCl$\\sb 3$, CDCl$\\sb 3$ were investigated by the variable-temperature solid-state $\\sp{2}$H NMR technique. Dppen stands for cis-1,2-bis(diphenylphosphano)ethylene.","In the third part of this thesis, an investigation on the dynamics of the spin-state interconversion in solution and other media is presented. The spin-state interconversion rate of the ferrous complexes series (Fe(6-Me-py)$\\sb{\\rm n}$(py)$\\sb{\\rm 3-n}$tren) (ClO$\\sb 4)\\sb 2$ (n = 0,1,2,3), where the ligand is the Schiff base of triethylaminotetraamine(tren) was measured by the means of the laser-flash photolysis technique. The temperature dependence of the relaxation constant of (Fe(6-Me-py)$\\sb 2$(py)tren) (ClO$\\sb 4)\\sb 2$ doped in PSS polymer film from 300K-4.2K can be fit well to quantum-mechanical tunneling theory. It is concluded that the spin-state relaxation process of this complex occurs by a quantum-mechanical tunneling mechanism. The inverse relationship between the zero-energy separation and the apparent activation energy was observed in the complex series. This observation suggests that the spin-state interconversion process of these complexes is in the "normal" region, not the inverted region. (Abstract shortened with permission of author.)","Made available in DSpace on 2014-12-15T23:19:03Z (GMT). No. of bitstreams: 1 8721791.pdf: 6925147 bytes, checksum: 147ebb8a251f8a60abe6f5474fd38099 (MD5) Previous issue date: 1987","Embargo set by: Seth Robbins for item 70548 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","337 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987."]},{"key":"dc:title","label":"Title","values":["Dynamics and Mechanism of Spin-State Interconversion in Iron Spin-Crossover Complexes"]}]}],"canonical_facts":{"dc:creator":["Xie, Chuan-Liang"],"dc:date":["2014-12-15T23:19:03Z","10000-01-01","1987"],"dc:description":["The work described in this dissertation is directed at a better understanding of the dynamics and mechanism of the so-called spin-crossover phenomenon. Several iron spin-crossover systems, including ferrous and ferric complexes, are investigated with various spectroscopic techniques and single-crystal X-ray structure determination.","In the first part the cooperativity of ferric spin-crossover complexes in the solid state and the influence of lattice solvation and metal dilution upon these properties is studied. The complex Fe(3-OMeSalAPA)$\\sb 2$ClO$\\sb 4$, where 3-OMeSalAPA is the Schiff base ligand condensed from one mole of 3-methoxylsalicylaldehyde with N-aminopropylaziridine, and its various halobenzene solvated forms were studied with $\\sp{57}$Fe Mossbauer and EPR spectroscopies, as well as magnetic susceptibility, DSC, single-crystal structure determination and variable temperature XRD techniques. It has been found from the experimental results that the ferric complex Fe(3-OMeSalAPA)$\\sb 2$ClO$\\sb 4$ and its solvated forms are spin-crossover systems of the gradual type.","In the second part of this thesis, an investigation of the correlation between the onset of solvate molecule dynamics and the spin-crossover phase transition is investigated. The complex Fe(dppen)$\\sb 2$Cl$\\sb 2$ with lattice solvate molecules of CH$\\sb 3$COCH$\\sb 3$, CD$\\sb 3$COCD$\\sb 3$, CH$\\sb 2$Cl$\\sb 2$, CD$\\sb 2$Cl$\\sb 2$, CHCl$\\sb 3$, CDCl$\\sb 3$ were investigated by the variable-temperature solid-state $\\sp{2}$H NMR technique. Dppen stands for cis-1,2-bis(diphenylphosphano)ethylene.","In the third part of this thesis, an investigation on the dynamics of the spin-state interconversion in solution and other media is presented. The spin-state interconversion rate of the ferrous complexes series (Fe(6-Me-py)$\\sb{\\rm n}$(py)$\\sb{\\rm 3-n}$tren) (ClO$\\sb 4)\\sb 2$ (n = 0,1,2,3), where the ligand is the Schiff base of triethylaminotetraamine(tren) was measured by the means of the laser-flash photolysis technique. The temperature dependence of the relaxation constant of (Fe(6-Me-py)$\\sb 2$(py)tren) (ClO$\\sb 4)\\sb 2$ doped in PSS polymer film from 300K-4.2K can be fit well to quantum-mechanical tunneling theory. It is concluded that the spin-state relaxation process of this complex occurs by a quantum-mechanical tunneling mechanism. The inverse relationship between the zero-energy separation and the apparent activation energy was observed in the complex series. This observation suggests that the spin-state interconversion process of these complexes is in the "normal" region, not the inverted region. (Abstract shortened with permission of author.)","Made available in DSpace on 2014-12-15T23:19:03Z (GMT). No. of bitstreams: 1 8721791.pdf: 6925147 bytes, checksum: 147ebb8a251f8a60abe6f5474fd38099 (MD5) Previous issue date: 1987","Embargo set by: Seth Robbins for item 70548 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","337 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1987."],"dc:identifier":["http://hdl.handle.net/2142/70382","(UMI)AAI8721791"],"dc:subject":["Chemistry, Inorganic"],"dc:title":["Dynamics and Mechanism of Spin-State Interconversion in Iron Spin-Crossover 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":"2026-07-22T22:26:02Z"}