Tuning the frontier orbital character of iron-thiolate complexes.

dc.contributor.advisorAshby, Michael,en_US
dc.contributor.authorMcguire, Danny Gordon.en_US
dc.date.accessioned2013-08-16T12:30:58Z
dc.date.available2013-08-16T12:30:58Z
dc.date.issued2000en_US
dc.description.abstractAnother part of this work describes the solvatochromatic effect of CpFe(CO) 2(SC6H5) dissolved in different solvents. A blue shift in the UV-vis spectra occurs as CpFe(CO)2(SC6H 5) is solvated in more polar solvents, which is evidence that the ground-state dipole moment is greater than the excited-state dipole moment.en_US
dc.description.abstractA portion of this work describes intermolecular hydrogen bonding studies using the compound CpFe(CO)2(SC6H 5) as a model system for iron-thiolate proteins. A correlation between the half-wave potential, E1/2, and the force constant, FCO, shows that there is a substantially smaller effect on the half-wave potential for hydrogen bonding compared with protonation, (about 30%). The X-ray crystallographic structures of CpFe(CO)2(SC 6H5) and [CpFe(CO)2(HSC6H5)]BF 4 show that protonation produces a shorter Fe-S bond. This indicates a stabilization of the Fe-S bond due to a weakening of the HOMO Fe(dpi)-S(ppi) antibonding orbital.en_US
dc.description.abstractAnother part of this work describes the synthesis and characterization of CpFe(dppe)(SC6H4-p-Z) where Z = OCH3, H, Cl, NO2, and CF3. A kinetic study of the methylation of CpFe(dppe)(SC6H4-p-Z) by CH3I shows a correlation between the relative donor ability of the aryl substituent and the reaction rate. From a Hammett plot, a value of rho = -2.14 was calculated which indicates a developing positive change on the sulfur center during the course of the reaction.en_US
dc.description.abstractElectron paramagnetic resonance experiments indicate that the HOMO of the compound [CpFe(dppe)(SC6H4-p-Z)]BF 4, where Z = OCH3, H, Cl, NO2, and CF3, is primarily metal in character. A linear free energy relationship is observed between the g-values and the relavative donor ability of the aryl substituent. Apparently, when the aryl substituent becomes more electron withdrawing and the g-values increase the HOMO becomes more metal in character.en_US
dc.description.abstractCyclic voltammetric data of CpFe(dppe)(SC6H4- p-Z) shows a linear free energy relationship between the relative donor ability of the aryl substituent and the half-wave potential of the compounds CpFe(dppe)(SC6H4-p-Z). Also, X-ray crystallographic analysis of CpFe(dppe)(SC6H4- p-OCH3), CpFe(dppe)(SC6H5) and CpFe(dppe)(SC 6H4-p-NO2) shows that the Fe-S bond distances decrease in the order of the derivatives: OCH3 > H > NO2. Apparently, the NO2 substituent best stabilizes the complex by withdrawing electron density from the HOMO which is the dpi-ppi antibonding orbital.en_US
dc.format.extentxxvi, 232 leaves :en_US
dc.identifier.urihttp://hdl.handle.net/11244/5996
dc.noteMajor Adviser: Michael Ashby.en_US
dc.noteSource: Dissertation Abstracts International, Volume: 61-06, Section: B, page: 3057.en_US
dc.subjectChemistry, Inorganic.en_US
dc.subjectElectronic excitation.en_US
dc.subjectChemistry, Organic.en_US
dc.subjectComplex compounds.en_US
dc.subjectHydrogen bonding.en_US
dc.thesis.degreePh.D.en_US
dc.thesis.degreeDisciplineDepartment of Chemistry and Biochemistryen_US
dc.titleTuning the frontier orbital character of iron-thiolate complexes.en_US
dc.typeThesisen_US
ou.groupCollege of Arts and Sciences::Department of Chemistry and Biochemistry
ou.identifier(UMI)AAI9975799en_US

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