Nucleophilic-Alkylation-Reoxidation: A Functionalization Sequence for Single-Wall Carbon Nanotubes
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- 作者：Ralf Graupner ; Jü ; rgen Abraham ; David Wunderlich ; Andrea Vencelová ; Peter Lauffer ; Jonas Rö ; hrl ; Martin Hundhausen ; Lothar Ley ; and Andreas Hirsch
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：May 24, 2006
- 年：2006
- 卷：128
- 期：20
- 页码：6683 - 6689
- 全文大小：286K
- 年卷期：v.128,no.20(May 24, 2006)
- ISSN：1520-5126
文摘
A new reaction sequence for the chemical functionalization of single-wall carbon nanotubes(SWNTs) consisting of the nucleophilic addition of t-BuLi to the sidewalls of the tubes and the subsequentreoxidation of the intermediates t-BunSWNTn- leading to t-BunSWNT was developed. During the formationof the t-BunSWNTn-, a homogeneous dispersion in benzene was formed due to the electrostatic repulsionof the negatively charged intermediates causing debundling. The entire reaction sequence can be repeated,and the degree of functionalization of the products (t-Bun)mSWNT (m = 1-3) increases with increasing m.Degrees of functionalization expressed as the carbon-to-addend ratio of up to 31 were reached. The reactionwas studied in detail by photoelectron spectroscopy, Raman spectroscopy, and scanning tunnelingmicroscopy (STM). The C 1s core level spectra reveal that the nucleophilic attack of the t-BuLi leads tonegatively charged SWNTs. Upon oxidation, this negative charge is removed. The valence band spectraof the functionalized samples exhibit a significant reduction in the 
-derived density of states. In STM, thecovalently bonded t-butyl groups attached to the sidewalls have been visualized. Raman spectroscopyreveals that addition of the nucleophile to metallic tubes is preferred over the addition to semiconductingtubes.
-derived density of states. In STM, thecovalently bonded t-butyl groups attached to the sidewalls have been visualized. Raman spectroscopyreveals that addition of the nucleophile to metallic tubes is preferred over the addition to semiconductingtubes.