This item is under embargo and not available online per the author's request. For access information, please visit http://libanswers.wustl.edu/faq/5640.
Date of Award
Doctor of Philosophy (PhD)
Late transition metals, specifically group 9 and 10 metals, have played a crucial role in the development of oxidation catalysis. These reactions led to the advancement of the current chemical industry to produce key intermediates such as alcohols, epoxides, aldehydes, ketones, and organic acids. Yet what may be of further significance is its application of these oxidative reactions in green and sustainable chemistry. To further develop a better understanding of these catalytic systems, key steps in the catalytic cycle such as C-C coupling and C-H functionalization reactions have been studied in detail. While these reactions have been studied extensively, the less stable intermediates in these oxidation reactions are limited. For example, in the case of Rh/Ir the common oxidation states involve +1 and +3 states and the low valent +2 or high valent +4 or +5 have limited characterization due to their instability. Nickel has a similar story, where catalytic cycles involving Ni0/II is common, the NiI intermediate is rarely characterized. Obtaining a complete characterization of these intermediates will provide insight to determine their role in the catalytic cycle and key electronic and steric features of the supporting ligand to design a more selective and efficient catalyst.
In order to study these short-lived intermediates, we implemented the use of a variety of tetradentate N,N’-dialkyl-2,11-diaza[3.3](2,6)pyridinophane (RN4) ligands and also designed a new phosphorous containing ligand P,P’-ditertbutyl-2,11-diphosphonate[3.3](2,6)pyridinophane (N2P2). This ligand allowed for the isolation and characterization of metal complexes in a wide range of oxidation states, and thereby leading to preliminary studies of C-C bond formation transformations.
Chair and Committee
Liviu M. Mirica
William E. Buhro, John R. Bleeke, Sophia E. Hayes, Nigam P. Rath,
Fuchigami, Kei, "Redox Chemistry of Late Transition Metal Complexes" (2017). Arts & Sciences Electronic Theses and Dissertations. 1187.
Available for download on Wednesday, December 15, 2117