Award Date

5-2011

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Radiochemistry

Department

Chemistry

First Committee Member

Ralf Sudowe, Chair

Second Committee Member

Kenneth Czerwinski

Third Committee Member

Dawn Shaughnessy

Graduate Faculty Representative

Steen Madsen

Number of Pages

140

Abstract

Studying the chemistry of transactinide elements does not only allow for these elements to be properly placed in the Periodic Table, but it also permits for the extrapolation of the electronic structure based upon the position of the element in the Periodic Table. In addition it enable for the assessment of the role that relativistic effects play in the chemical behavior of the heaviest elements. An improved understanding of the role of relativistic effects in chemistry of the heaviest elements allows for a better understanding of the fundamentals principles that govern the Periodic Table. In order to investigate the chemistry of the transactinides, chemical studies on the homologs and pseudo-homologs of the element must first be performed.

Chemical studies of the homologs and pseudo-homologs can be completed in a number of ways. Gas-phase chemistry, solvent extraction and ion-exchange chromatography have all been used to study a number of transactinide elements as well as their respective homologs and pseudo-homologs. No matter the method of study, a given system must fulfill the following requirements to be considered suitable; fast kinetics, high separation factors, large number of exchange steps, highly selective and samples easily prepared for alpha spectroscopy. The system must allow for rapid separation due to the short half-lives of transactinide elements (on the order of a few seconds up to a minute). A large number of exchange steps are necessary due to the fact there is only one atom present at a given time. In order for one atom to be statistically representative of a macroscopic amount the atom must undergo many interactions with the two phases of the separation system. The system should also be highly selective to ensure that background contamination is removed and separation of the transactinide from its homologs and pseudo-homologs is achieved. Finally, the samples generated from the separation must be easily and rapidly prepared for alpha spectroscopy so that the decay of the short lived transactinide element can be directly detected.

The aim of this research is to develop two separation schemes for elements 104 and 105 that fulfill all of these requirements. For element 105 the proposed extractant molecule is a tetra diglycoloamide in a mixed acid matrix. In the case of element 104 crown ether based ligands of interest. The proposed separation schemes for element 104 and 105 are based on both commercially available and in-house synthesized resins.

Keywords

Chromatographic analysis; Crown ethers; DGA; Dubnium; Extraction chromatography; Rutherfordium; Superheavy elements; Transactinide

Disciplines

Analytical Chemistry | Chemistry | Inorganic Chemistry | Nuclear | Radiochemistry

Language

English


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