Chaturvedi H, Poler J C
Department of Chemistry and Center for Optoelectronics and Optical Communications, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA.
J Phys Chem B. 2006 Nov 16;110(45):22387-93. doi: 10.1021/jp061952f.
Single-walled carbon nanotubes (SWNTs) bind strongly to rigid ruthenium metallodendrimers. High valence ions effectively coagulate these nanotubes from stable dispersions in N,N-dimethylforamide. While ruthenium salts and small Ru(diimine)(3) complexes also coagulate the nanotubes, they require much higher concentrations and are easily extracted from the nanotubes with acetonitrile. Enantiomerically pure ruthenium metallodendrimer Lambda(6)Delta(3)Lambda-Ru(10)PF(6)(-) is shown to bind strongly and specifically to the SWNTs. Most of the nanotube's ends are functionalized with this large (5.8 nm), optically active, rigid supramolecular complex. We study the binding capacity with UV-vis and atomic absorption spectroscopy. Imaging the functionalized nanotubes with scanning electron microscopy and atomic force microscopy (AFM) yields direct confirmation of end functionalization. Statistical analysis of the AFM images shows the morphology of the functionalized ends is consistent with the nanotubes binding to one of the endo- or exoreceptors around the dendrimer. Implications of these results toward efficient nanomanufacturing of carbon nanotube devices are discussed.
单壁碳纳米管（SWNTs）与刚性钌金属树枝状大分子强烈结合。高价离子能有效地使这些纳米管从在N，N - 二甲基甲酰胺中的稳定分散体中凝聚。虽然钌盐和小的[Ru（二亚胺）（3）]（2 +）配合物也能使纳米管凝聚，但它们需要更高的浓度，并且很容易用乙腈从纳米管中萃取出来。对映体纯的钌金属树枝状大分子[Λ（6）Δ（3）Λ - Ru（10）]（20 +）[PF（6）（ - ）]（20）被证明能与单壁碳纳米管强烈且特异性地结合。大多数纳米管的末端都被这种大的（5.8纳米）、具有光学活性的刚性超分子配合物功能化。我们用紫外 - 可见光谱和原子吸收光谱研究了其结合能力。用扫描电子显微镜和原子力显微镜（AFM）对功能化的纳米管进行成像，直接证实了末端功能化。对AFM图像的统计分析表明，功能化末端的形态与纳米管与树枝状大分子周围的内受体或外受体之一结合的情况一致。讨论了这些结果对碳纳米管器件高效纳米制造的意义。
