Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Mead, Keith T.

Committee Member

Foster, Stephen C.

Committee Member

Emerson, Joseph

Committee Member

Lewis, Edwin

Committee Member

Sygula, Andrzej

Date of Degree

1-1-2015

Document Type

Dissertation - Open Access

Major

Chemistry

Degree Name

Doctor of Philosophy

College

College of Arts and Sciences

Department

Department of Chemistry

Abstract

The synthesis and characterization of the first series of tetra-NHC-Ag(I)-X cubane clusters are reported. The clusters were characterized with 1H and 13C NMR spectroscopy, ESI-TOF MS, and single crystal X-ray diffraction. Crossover experimental data were consistent with intramolecular exchange, which can be visualized by a molecular rotating type mechanism. Additionally, -NHC Zr(IV) pincer type complexes were synthesized and characterized with 1H and 13C NMR spectroscopy, CHN combustion analysis, and X-ray crystallography. A large rate effect was observed based on the halogen and metal center for the hydroamination/cyclization of unactivated aminoalkenes. Zirconium based pincers provided faster reaction rates than their hafnium counterparts (Zr>Hf). Precatalysts with iodide ligands provided faster reaction rates than their bromide and chloride counterparts (I>Br>Cl). The mechanism of hydroamination for Zr(IV) -NHC complexes was also investigated for bis(iodide) and bis(amido) ligand classes. A full kinetic analysis of substrate and precatalyst have been identified along with the formation of small amounts of an oxidized product. The proposed mechanism contains an imido-type intermediate whose formation depends greatly on which set of ligand class is used.

URI

https://hdl.handle.net/11668/19611

Comments

catalysis||organometallic

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