Abstract
dc:description.abstractAt the conception of this research, a separation methodology for obtaining purified mctallofullerene [A<sub>m</sub>@C<sub>2n</sub>, m = # of metal atoms, A, and C<sub>2n</sub> = # of carbons in the surrounding cage] samples was not yet developed. Isolation of these metal-encapsulated fullerenes was strongly desired for characterization of their physical and chemical properties. Predicted applications for these novel species include their use as possible superconductors, catalysts, and non-linear optical devices. However, initial purification efforts have been hindered by several difficulties. These factors include a low abundance (< 1%) in the raw extract, uncertain stability in aerobic environments, co-elution of A<sub>m</sub>@C<sub>2n</sub> with empty-cage fullerenes, and the need for selective chromatographic detection. In this research, these difficulties have been overcome with the development of a continuous-flow, on-line HPLC-EPR apparatus. Advantages include a selective, non-invasive detector with chromatographic separations being performed in a controlled anaerobic environment. This on-line approach permits the selective detection of only those metallofullerenes with an odd-number of encapsulated atoms. The ability to continually monitor separations of these paramagnetic species ultimately permits the optimization of chromatographic parameters. The methodology developed from this on-line HPLC-EPR approach has ultimately resulted in purified empty-cage (C₆₀, C₇₀...C₉₆) and metallofullerene samples (Sc₂@C₇₄, Sc₂@C₇₆, Sc₂@C₇₈, Sc₂@C₈₀, Sc₂@C₈₂, Sc₂@C₈₄ - two isomers, Sc₂@C₈₆, Sc₂@C₈₈, Sc₂@C₉₀, Sc₃@C₈₂, Sc₄@C₈₂, La₂@C₇₂, Er@C₈₂, Er₂@C₈₂ - two isomers, and Er₂@C₉₂).
Degree
thesis:*- Name thesis:degree_name
- Ph. D.
- Level thesis:degree_level
- doctoral
- Discipline thesis:degree_discipline
- Chemistry
- Department dc:contributor.department
- Chemistry
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 1995
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Stevenson, Steven A.
- Chair dc:contributor.committeechair
-
- Dorn, Harry C.
- Committee members dc:contributor.committeemember
-
- Anderson, Mark R.
- Brewer, Karen J.
- Taylor, Larry T.
- Bell, Harold M.
Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
- Language dc:language.iso
- en
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-10032005-171425
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/29176