Liang Feng, Alemany Lawrence B, Beach Jonathan M, Billups W Edward
Department of Chemistry and Center for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA.
J Am Chem Soc. 2005 Oct 12;127(40):13941-8. doi: 10.1021/ja052870s.
Alkylation of nanotube salts prepared using either lithium, sodium, or potassium in liquid ammonia yields sidewall-functionalized nanotubes that are soluble in organic solvents. Atomic force microscopy and transmission electron microscopy studies of dodecylated SWNTs prepared from HiPco nanotubes and 1-iodododecane show that extensive debundling results from intercalation of the alkali metal into the SWNT ropes. TGA-FTIR analyses of samples prepared from the different metals revealed radically different thermal behavior during detachment of the dodecyl groups. The SWNTs prepared using lithium can be converted into the pristine SWNTs at 180-330 degrees C, whereas the dodecylated SWNTs prepared using sodium require a much higher temperature (380-530 degrees C) for dealkylation. SWNTs prepared using potassium behave differently, leading to detachment of the alkyl groups over the temperature range 180-500 degrees C. These differences can be observed by analysis of the solid-state 13C NMR spectra of the dodecylated SWNTs that have been prepared using the different alkali metals and may indicate differences in the relative amounts of 1,2- and 1,4-addition of the alkyl groups.
在液氨中使用锂、钠或钾制备的纳米管盐进行烷基化反应，可得到可溶于有机溶剂的侧壁功能化纳米管。对由HiPco纳米管和1-碘十二烷制备的十二烷基化单壁碳纳米管进行原子力显微镜和透射电子显微镜研究表明，碱金属插入单壁碳纳米管绳索中会导致大量解束。对由不同金属制备的样品进行热重-傅里叶变换红外光谱分析，结果显示在十二烷基脱离过程中热行为存在显著差异。用锂制备的单壁碳纳米管在180 - 330℃可转化为原始单壁碳纳米管，而用钠制备的十二烷基化单壁碳纳米管脱烷基则需要更高的温度（380 - 530℃）。用钾制备的单壁碳纳米管表现不同，在180 - 500℃温度范围内烷基会脱离。通过分析用不同碱金属制备的十二烷基化单壁碳纳米管的固态13C核磁共振谱可以观察到这些差异，这可能表明烷基1,2 - 加成和1,4 - 加成的相对量存在差异。
