Date of Award

12-2010

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Chemistry

Advisor

Echegoyen, Luis

Committee Member

Brumaghim , Julia

Committee Member

Chumanov , George

Committee Member

Smith , Rhett

Abstract

Since the introduction of semiconductors in the second half of the 20th century, advancements in electronics and technology have been tremendous. In particular, the rapid development of silicon-based computer chip technology and miniaturization of electronic components has been tremendous. Since silicon-based materials have a limit in terms of size, scientists proposed that individual molecules could behave as single electronic components for high degree of miniaturization.
Given that the molecules of interest must have dimensions on the nanometer scale, be able to bind to the electrode surface and have electron donor-acceptor properties, C60 fullerene has been a prime candidate for these studies. It has also been found that a covalent bond between a C60 derivative and the surface of a metal substrate enhances the electron tunneling conductance upon accepting electrons, demonstrating the importance of the design and regioselective synthesis of C60 fullerene derivatives. However, regiochemical control is very challenging given its high symmetry.
The work presented here explores the synthesis, characterization and electrochemical properties of pentakis-, hexakis- and heptakis-adducts of C60 and some of its Fe-complexes under a regio-controlled protection-deprotection protocol. Derivatives were synthesized using two known reactions: cyclopropanation and 1,3-dipolar cycloaddition reactions, better known as: as the Bingel-Hirsch and Prato reactions, respectively.
This approach allowed us to introduce the addends in specific positions over the sphere. For example, two pyrrolidine groups were bonded in a trans-1 relationship with respect to each other. These adducts were characterized by means of 1H, 13C, and 2D-NMR, UV-vis, MALDI-TOF MS and ESI-MS. Their electrochemical properties were analyzed by Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) experiments.

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