Fu Kefu, Li Huaping, Zhou Bing, Kitaygorodskiy Alex, Allard Lawrence F, Sun Ya-Ping
Department of Chemistry and Center for Advanced Engineering Fibers and Films, Howard L. Hunter Chemistry Laboratory, Clemson University, Clemson, South Carolina 29634-0973, USA.
J Am Chem Soc. 2004 Apr 14;126(14):4669-75. doi: 10.1021/ja030312c.
A systematic investigation on the unusual attachment of labile deuterium to carbon nanotubes in deuterated water and alcohols is reported. The carbon nanotubes were solubilized through the established functionalization of the nanotube-bound carboxylic acids to allow solution-phase reaction and characterization. The deuterium attachment was found under several experimental conditions, including the use of deuterated ethanol as a co-reactant in the nanotube functionalization reaction and the refluxing of functionalized or simply purified carbon nanotubes in deuterated water and alcohols. The solubility of the functionalized carbon nanotube samples in common organic solvents and water allowed unambiguous (2)H NMR characterization. The reproducible broad (2)H NMR signal at approximately 6.5 ppm is assigned to carbon nanotube-attached deuterium species. The assignment is supported by the results from FT-IR measurements. The carbon-deuterium interaction is so strong that the corresponding vibration resembles the typical C-D stretching mode in the characteristic frequency region. The FT-IR peak intensities also correlate well with the (2)H NMR signal integrations in a series of samples. Mechanistic implications of the results are discussed.
报道了一项关于在重水和醇类中不稳定的氘与碳纳米管异常结合的系统研究。通过对纳米管结合的羧酸进行既定的功能化处理使碳纳米管溶解，以便进行溶液相反应和表征。在多种实验条件下都发现了氘的结合，包括在纳米管功能化反应中使用重水乙醇作为共反应物，以及将功能化或简单纯化的碳纳米管在重水和醇类中回流。功能化碳纳米管样品在常见有机溶剂和水中的溶解性使得能够进行明确的2H NMR表征。在约6.5 ppm处可重现的宽2H NMR信号归属于与碳纳米管结合的氘物种。该归属得到了FT-IR测量结果的支持。碳-氘相互作用非常强，以至于相应的振动在特征频率区域类似于典型的C-D伸缩模式。在一系列样品中，FT-IR峰强度也与2H NMR信号积分良好相关。讨论了这些结果的机理意义。
