Hu Ming, Ye Feng-Ying, Yu Wei, Sheng Kang, Xu Zhi-Rong, Fu Jin-Jin, Wen Xin, Feng Hai-Tao, Liu Minghua, Zheng Yan-Song
Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology Wuhan 430074 China
Beijing National Laboratory for Molecular Science (BNLMS), CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China.
Chem Sci. 2024 Sep 10;15(40):16627-36. doi: 10.1039/d4sc03599b.
The helical structure is often the key factor for forming and enhancing chiroptical properties, such as circular dichroism (CD) and circular polarized luminescence (CPL) effects. However, no matter whether helical molecules or helical aggregates, they usually display modest chiroptical signals, which limits their practical applications. Herein, chiral tetraphenylethylene (TPE) bimacrocycles prepared in almost quantitative yield show strong and repeatable CD signals up to more than 7000 mdeg, which is very rare for general organic compounds, besides emitting very strong CPL light with an absolute value up to 6.2 × 10. It is found that the superhelices formed by self-inclusion between the cavity and outward cyclohexyl ring of TPE bimacrocycles in crystal state are the key factor for highly enhanced chiroptical effect, and the self-inclusion superhelices in assemblies are confirmed by High Resolution Transmission Electron Microscopy (HR-TEM), Powder X-ray Diffraction (XRD) and Fourier Transform Infrared Spectrometry (FT-IR) data. Furthermore, the chiral TPE bimacrocycle shows great potential in chiral recognition and chiral analysis not only for chiral acids but also for chiral amines, chiral amino acids, and neutral chiral alcohol. Using self-inclusion helical nanocrystals of chiral macrocycles, this work provides a new strategy for chiroptical materials with excellent chiroptical properties.
螺旋结构通常是形成和增强手性光学性质的关键因素，如圆二色性（CD）和圆偏振发光（CPL）效应。然而，无论是螺旋分子还是螺旋聚集体，它们通常都显示出适度的手性光学信号，这限制了它们的实际应用。在此，以几乎定量的产率制备的手性四苯乙烯（TPE）双大环化合物显示出高达7000 mdeg以上的强且可重复的CD信号，这对于一般有机化合物来说是非常罕见的，此外还发射出绝对值高达6.2×10的非常强的CPL光。研究发现，TPE双大环化合物在晶体状态下由空腔与向外的环己基环之间的自包结形成的超螺旋是手性光学效应高度增强的关键因素，通过高分辨率透射电子显微镜（HR-TEM）、粉末X射线衍射（XRD）和傅里叶变换红外光谱（FT-IR）数据证实了组装体中的自包结超螺旋。此外，手性TPE双大环化合物在手性识别和手性分析方面不仅对手性酸，而且对手性胺、手性氨基酸和中性手性醇都显示出巨大的潜力。利用手性大环化合物的自包结螺旋纳米晶体，这项工作为具有优异手性光学性质的手性光学材料提供了一种新策略。
