Date of Award

1-1-2012

Document Type

Campus Access Dissertation

Department

Chemistry and Biochemistry

Sub-Department

Chemistry

First Advisor

Hans-Conrad zur Loye

Abstract

The overarching theme of my thesis is the coordination chemistry of organic compounds to a variety of cations across the periodic table. The synthesis of both these hybrid coordination compounds as well as of the organic components is discussed, as well as the accompanying characterizations.

The very first chapter of this thesis involves work done at Oak Ridge National Laboratory over a period of five months. It details the synthesis and solvent-solvent extraction capabilities of a ligand in the BTP class of molecules. This work was done both as a general study, and in support of an engineering campaign at ORNL which aimed to separate transuranium actinides from on-site bulk lanthanide waste. The molecule in question had comparable separation capabilities to a reference molecule and was robust toward varying extraction conditions. Unfortunately, the kinetics were slow enough to render it less than desirable without further optimization for industrial applications.

In four of the following chapters, the current progress of a research project begun in January 2011 is reported. This project involved the hydrothermal coordination of the uranyl cation to a number of small ligands, which resulted in the eleven luminescent coordination complexes described in those chapters. Of particular interest are the structures containing mixed-valent U3O8 layers generated in situ in chapter II, and the structure containing a cation-cation interaction highlighted in chapter IV. Both of these topologies have unique aspects, the first in the method of generation, and the second for its presence in a uranium-containing compound. In summation of the other structures, all except one contained the typical luminescent signature of the uranium VI cation, which holds promise for photocatalytic potential in these structures similar to that of the uranium VI cation. However, unlike the uranyl salts, these structures are not readily soluble in water and thus are more stable for use in photocatalytic applications. The exception was a complex of the uranyl cation with the sulfurcontaining molecule PYTAC. This compound had a significantly altered fluorescence in keeping with the ligand's excitation band near the uranyl emission, and demonstrated that the characteristic fluorescence of the uranyl cation can be altered if an appropriate complexing molecule is selected.

Three of the remaining chapters detail coordination work done with main group cations. This work was prompted by the synthesis of the HP3PA ligand, a rigid alkyne-containing molecule which formed a luminescent coordination compound with the lead cation. Six additional compounds were synthesized containing the main group compounds lead and indium, two of which were luminescent courtesy of the coordinating molecule.

The final four chapters detail other solid state compounds synthesized and published over the course of my graduate school career. Six of these were synthesized hydrothermally, and the final was synthesized via molten flux growth with cesium hydroxide.

Rights

© 2012, Rachel Charlotte Severance

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