Endohedral metallofullerenes (EMFs) have attracted increasing attention during past decades due to their novel structures and potential applications in a variety of fields such as biomedical applications and molecular electronics. This dissertation addresses the structural characterization and hydrogenation of EMFs.
A family of novel large cage yttrium-based TNT EMFs Y₃N@C₂ₙ (n=40-44) was prepared, separated, and structurally characterized for the first time. The structure of Y₃N@C₂ₙ (n=40-44) is proposed by the experimental and computational ¹³C NMR studies. The first ⁸⁹Y NMR results for Y₃N@<I>Iₕ</i>-C₈₀, Y₃N@<I>Cₛ</i>-C₈₄ and Y₃N@<I>D₃</i>-C₈₆ reveal a progression from isotropic to restricted (Y₃N)⁶⁺</sup> cluster motional processes.
The di-metallic EMF Y₂C₉₄ is distinguished as a metal-carbide based EMF, Y₂C₂@<I>D₃</i>-C₉₂. The carbide within the cage is successfully detected by ¹³C NMR. The scalar J<sub>Y-C</sub> coupling between the yttrium atoms and the C₂ unit within the C₉₂ cage is successfully observed, suggesting the C₂ unit rotates rapidly around the yttrium atoms.
Two paramagnetic endohedral metalloheterofullerenes, Y₂@C₇₉N and Gd₂@C₇₉N, were also synthesized and characterized. The EPR study demonstrated that the spin density is mainly localized between the two metallic ions. A spin-site exchange system could be constructed between Y₂@C₇₉N and the organic donor TMPD. Being a unique paramagnetic material, Gd₂@C₇₉N displays an unusual stability over a wide temperature range, which could be very useful in optical and magnetic areas.
Functionalization of EMFs is another point of interest in this dissertation. Hydrogenated Sc₃N@C₈₀ was synthesized and characterized. Our study demonstrated that the Sc₃N@C₈₀ can be fully hydrogenated and the pristine Sc₃N@C₈₀ can be recovered from Sc₃N@C₈₀H₈₀ after being heated in vacuum. The hydrogenated EMFs could be potential hydrogen storage materials. / Ph. D.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/77994 |
| Date | 26 January 2010 |
| Creators | Fu, Wujun |
| Contributors | Chemistry, Dorn, Harry C., Gibson, Harry W., Heflin, James R., Ritter, Alfred L., Morris, John R. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | en_US |
| Detected Language | English |
| Type | Dissertation, Text |
| Format | application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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