Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8565, Japan.
J Am Chem Soc. 2017 Nov 15;139(45):16068-16071. doi: 10.1021/jacs.7b09142. Epub 2017 Nov 1.
Although enantiomeric separation of single-wall carbon nanotubes is possible, their enantiomeric purity (EP) remains an issue due to a lack of effective evaluation methods. In this work, we report the EP of (6,5) carbon nanotube enantiomers using flavin mononucleotide (FMN) as an enantiomer-sensitive dispersant. The enantiomers (6,5) and (11,-5) were separated by a gel column chromatography method and dispersed in a FMN aqueous solution. In these solutions, (6,5) and (11,-5) showed E optical transitions at different wavelengths due to handedness-dependent interactions with the FMN molecule, which enabled us to estimate each concentration, namely, the EP. We prepared six intermediate-purity enantiomer samples by mixing the (6,5) and (11,-5) enantiomers and measured their circular dichroism (CD) spectra. The CD signal was confirmed to change linearly with the EP. Using this relationship, we can estimate the EP of any mixture of (6,5) and (11,-5) from its CD intensity.
虽然单壁碳纳米管可以实现对映体分离，但由于缺乏有效的评价方法，其对映体纯度（EP）仍然是一个问题。在这项工作中，我们报告了使用黄素单核苷酸（FMN）作为对映体敏感分散剂的（6,5）碳纳米管对映体的 EP。通过凝胶柱层析法分离对映体（6,5）和（11,-5），并将其分散在 FMN 水溶液中。在这些溶液中，（6,5）和（11,-5）由于与 FMN 分子的手性依赖性相互作用，在不同波长处表现出 E 光跃迁，这使我们能够估计每种浓度，即 EP。我们通过混合（6,5）和（11,-5）对映体制备了六个中等纯度的对映体样品，并测量了它们的圆二色性（CD）光谱。CD 信号被证实与 EP 呈线性变化。利用这种关系，我们可以根据 CD 强度来估计（6,5）和（11,-5）的任何混合物的 EP。
