Synthesis of transition metal containing molecular wires
Jessica Koehnea, Wendy Fan*, b, Chongwu Zhouc, Geetha R. Dholakiab, M. Meyyappana, and Jie Hanb
aNASA Ames Center for Nanotechnology, NASA Ames Research Center,
Moffett Field, CA 94035 USA
bEloret Corporation, NASA Ames Research Center
Moffett Field, CA 94035 USA
cUniversity of Southern California
This is an abstract
for a presentation given at the
10th
Foresight Conference on Molecular Nanotechnology
The electron transport property of conjugated oligomers have been exploited intensively for their potential applications as molecular electronic devices (1). A class of such compounds containing bidentate 2,2'-dipyridine unit is of interest due to their rigid rod-like topologies, interesting electronic structures and particularly their ability to coordinate transition metal ions (2). Owing to the unique electronic structures, transition metals and their corresponding ions possess multiple stable oxidation states and are capable of facile redox reactions. Therefore conjugated oligomers containing transition metals integrate charge transport properties from both oligomers and their coordinated metals thus yield new and tunable electronic properties (3). These integrated systems may allow electron transport to be conveniently studied through well-defined charge states, possibly down to single-atom level (4). In addition, lower band gaps and versatile self-assembly into suparmolecular structures can result from metal-ligand coordination (4). Here we report the synthesis and characterization of a class of dithiol terminated oligo(phenyleneethynylene)s containing a center unit of transition metal chelated 2,2'-dipyridine-5,5'-diyl moiety (Figure). The self-assembly monolayers (SAM) were prepared by adsorption of these molecules onto gold surface and the subsequent electronic conduction behavior studied through I/V measurements and scanning tunneling microscopy.
References:
- Mullen, K. and Wegner,G. Ed. Electronic Materials: The oligomer approach, Wiley-VCH, 1998.
- Ley, K.D. and Schanze, K.S. Coordination Chem. Rev. 171, 287 (1998).
- Schwab, P.F.H., Levin M.D. and Michl J. Chem. Rev. 99, 1863 (1999).
- Park J., Pasupathy, A. N., Goldsmith, J.I., Chang C., Yaish Y., Petta J.R., Rinkoski, M., Sethna J.P., Abruna, H.D., MaEuen, P.L. and Ralph D.C. "Coulomb blockade and the Kondo effect in single atom transistors" To be publsihed.
*Corresponding Address:
Wendy Fan
Eloret Corporation, NASA Ames Research Center
MS 229-01, Moffett Field, CA 94035 USA
Phone: 650-604-2122 Fax: 650-604-5244
Email: wfan@mail.arc.nasa.gov
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