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dc.contributor.advisorGhosh, Abhik
dc.contributor.authorGanguly, Sumit
dc.date.accessioned2017-12-12T09:40:50Z
dc.date.available2017-12-12T09:40:50Z
dc.date.issued2017-11-30
dc.description.abstractIn recent years, first-row metallocorroles have provided some of the most instructive examples of noninnocent ligands. This thesis presents a study of some 50 iron, manganese, and cobalt corrole complexes with different axial ligands (including approximately 30 new compounds and 6 new X-ray structures) with emphasis on their noninnocent/innocent character. UV-vis spectroscopy has for some time provided a convenient empirical probe of ligand noninnocence in transition metal meso-tris(para-X-phenyl)corrole (TpXPC) complexes. Redshifts of the Soret maxima with increasing electron-donating character of the para-substituent X have indicated noninnocent systems, while substituent-insensitive Soret maxima have indicated innocent corrole ligands. I have greatly expanded the scope of this optical probe of noninnocence and used it to identify new classes of noninnocent metallocorroles. The μ-oxo diiron corroles have long been thought of as true Fe(IV) complexes. However, as discussed in Paper A, a study of the optical spectra of {Fe[TpXPC]}2O derivatives along with DFT calculations have indicated a noninnocent description for these complexes. Iron-aryl corroles are classic examples of true Fe(IV) species. Several Fe-aryl corroles were synthesized and examined together with other Fe corrole derivatives by means of UV-vis and NMR spectroscopy and electrochemistry in a detailed study for ligand noninnocence in a wide range of Fe corroles (Paper B). Analogous studies of Mn-aryl corroles were also carried out (Chapter 3), but these have not yet been written up as a manuscript. A collaborative study with the Stanford Synchrotron Radiation Lightsource also provided the first X-ray absorption spectroscopic analysis of the question of ligand noninnocence in Fe corrole complexes. Cobalt-triphenylphosphine (Co-PPh3) corroles have also been thought of as classic low-spin Co(III) complexes until now. An examination of the UV-vis spectra of Co-PPh3 corroles and DFT calculations again indicated a partially noninnocent Co(II) corrole radical description for these complexes (Paper C). In contrast, an innocent description was indicated for Rh-PPh3 corroles. Finally, as discussed in Paper D, Co corrole pyridine adducts were likewise studied with a variety of spectroscopic techniques and the noninnocent behavior of the monopyridine adducts was elucidated in considerable detail.en_US
dc.description.doctoraltypeph.d.en_US
dc.description.popularabstractThe red color of blood (hemoglobin) and the green color of leaves (chlorophyll) both result from different forms of a ring-shaped molecule called porphyrin, which can bind a metal atom at its center. That metal atom is iron in the case of hemoglobin and magnesium in the case of corroles. In my own work, I have constructed slightly tighter molecular rings called corroles and inserted three different elements – manganese, iron, and cobalt – at their centers. As a result of tighter binding between the ring and the metal atoms, these artificial constructs exhibit quite different properties than the natural porphyrins. There are already indications that a number of these molecules act as catalysts for a variety of processes of great societal importance such as the generation of hydrogen from water. The expectation is that the insights I have obtained will lead to significantly better catalysts than what is available today.en_US
dc.descriptionThe paper C and D of this thesis are not available in Munin. <br> Paper C: Ganguly, S., Renz, D., Giles, L. J., Gagnon, K.J., McCormick, L. J., Conradie, J., Sarangi, R., Ghosh, A.: “Cobalt- and Rhodium-Corrole-Triphenylphosphine Complexes Revisited: The Question of a Noninnocent Corrole». (Manuscript). Published version available in <a href=http://dx.doi.org/10.1021/acs.inorgchem.7b01828> Inorg. Chem.2017 </a> <br> Paper D: Ganguly, S., Conradie, J., Bendix. J., Gagnon, K.J., McCormick, L. J., Ghosh, A.: “Electronic Structure of Cobalt-Corrole-Pyridine Complexes: Noninnocent Five-coordinate Co(II) Corrole-Radical States». (Manuscript). Published version available in <a href=http://dx.doi.org/10.1021/acs.jpca.7b09440> J. Phys. Chem. A, 2017. </a>en_US
dc.identifier.isbn978-82-8236-278-8 (trykt) 978-82-8236-279-5 (pdf)
dc.identifier.urihttps://hdl.handle.net/10037/11848
dc.language.isoengen_US
dc.publisherUiT Norges arktiske universiteten_US
dc.publisherUiT The Arctic University of Norwayen_US
dc.rights.accessRightsopenAccessen_US
dc.subject.courseIDDOKTOR-004
dc.subjectVDP::Mathematics and natural science: 400::Chemistry: 440::Inorganic chemistry: 442en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Kjemi: 440::Uorganisk kjemi: 442en_US
dc.titleLigand Noninnocence In Manganese, Iron, and Cobalt Corrolesen_US
dc.typeDoctoral thesisen_US
dc.typeDoktorgradsavhandlingen_US


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