Department of Chemistry and Research Institute of Natural Sciences, Gyeongsang National University, Jinju, 660-701, Korea.
Molecular Design and Function Group, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan.
Chemistry. 2018 Aug 9;24(45):11763-11770. doi: 10.1002/chem.201802086. Epub 2018 Jul 18.
We describe the role of amide groups formed by achiral and chiral moieties to study supramolecular helicity at the molecular level and the correlation between helicity and solvent properties at the supramolecular level. Using circular dichroism (CD) spectroscopy, we observed the CD spectra of supramolecular gel 1, which comprised a triphenylamine (TPA) core, terpyridine, and alanine moieties, formed in various solvents. The strong positive CD signals of supramolecular gel 1 formed in organic solvents, such as chloroform, tetrahydrofuran (THF), and dichloromethane, which have low polarity and a low acceptor number, were observed at 350 nm, indicating right-handed helicity. In contrast, the negative CD signals of supramolecular gel 1 formed in mixed DMSO/water (5:1 v/v), methanol, ethanol, and n-propanol were obtained at 350 nm, indicating left-handed helicity. These findings suggest that the helicity of supramolecular gel 1 was strongly influenced by the solvent properties. Indeed, atomic force spectroscopy images showed the right- and left-handed helicity of supramolecular gel 1 formed in various organic solvents, which was pure helicity.
我们描述了由非手性和手性部分形成的酰胺基团在分子水平上研究超分子螺旋以及在超分子水平上螺旋与溶剂性质之间的相关性的作用。我们使用圆二色性（CD）光谱法观察了由三苯胺（TPA）核心、三吡啶和丙氨酸部分组成的超分子凝胶 1 在各种溶剂中形成的 CD 光谱。在极性低、接受体数低的有机溶剂（如氯仿、四氢呋喃（THF）和二氯甲烷）中形成的超分子凝胶 1 的强正 CD 信号在 350nm 处出现，表明其具有右旋螺旋性。相比之下，在混合 DMSO/水（5:1v/v）、甲醇、乙醇和正丙醇中形成的超分子凝胶 1 的负 CD 信号在 350nm 处获得，表明其具有左旋螺旋性。这些发现表明超分子凝胶 1 的螺旋性受到溶剂性质的强烈影响。事实上，原子力显微镜图像显示了在各种有机溶剂中形成的超分子凝胶 1 的右旋和左旋螺旋性，其为纯螺旋性。
