东北林业大学李伟团队报道了超分子聚合物光控手性螺旋的手性纤维素纳米薄膜圆极化能力的研究。相关研究成果发表在2022年2月8日出版的《德国应用化学》

圆偏振光（CPL）可以将手性结构信息传递到化学产品中，是不对称光化学的关键。

该文中，研究人员展示了手性纤维素纳米晶体（CNC）薄膜的圆极化能力，以触发非手性超分子聚合物向螺旋结构的光对准。通过自组装CNC膜，生成了右旋透射（T-）CPL，将非晶态偶氮苯（Azo）超分子聚合物诱导成手性结构。T-CPL对间隔较长的偶氮聚合物的手性诱导作用增强。经T-CPL辐照后，液晶超分子聚合物的吸收不对称因子（g-abs）值可显著增大（超过10倍）。此外，通过将碳点集成到CNC薄膜中，实现了具有相当大的发光不对称因子（Glum）高达-0.66的CPL发射，并且可以用于具有高手性光学性质的偶氮聚合物的光对准。

该研究为CPL活性材料对超分子聚合物的光调制提供了新的见解。

附：英文原文

Title: Exploring the circular polarization capacity from chiral cellulose nanocrystal films for photo-controlled chiral helix of supramolecular polymers

Author: Mingcong Xu, Guangyao Li, Wei Li, Bang An, Jiaming Sun, Zhijun Chen, Haipeng Yu, Jian Li, Guang Yang, Shouxin Liu

Issue&Volume: 2022-02-08

Abstract: Circularly polarized light (CPL) is key to asymmetric photochemistry as it could impart the chiral organization information into chemical products. Here, we demonstrate the circular polarization capacity from chiral cellulose nanocrystal (CNC) films to trigger photo-alignment of achiral supramolecular polymers into helical structures. Right-handed transmitted (T-) CPL was generated from self-assembled CNC films, which induced amorphous azobenzene (Azo) supramolecular polymers into chiral structures. The chiral induction effect of T-CPL is enhanced on Azo polymers with longer spacers. The absorptive dissymmetry factor (g  abs  ) values of liquid crystal supramolecular polymers can be amplified significantly (over 10 times) after T-CPL irradiation. Moreover, by integrating carbon dots into CNC films, CPL emission with considerable luminescence dissymmetry factor (g  lum  ) up to -0.66 was achieved, and it could be used for the photo-alignment of Azo polymers with high chiroptical property. This work provides new insight for the photo modulation of supramolecular polymers by CPL-active materials.

DOI: 10.1002/anie.202117042

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202117042