Zhang Xu-Jie, Morishita Daiki, Aoki Tsubasa, Itoh Yoshimitsu, Yano Keiichi, Araoka Fumito, Aida Takuzo
Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Chem Asian J. 2022 May 16;17(10):e202200223. doi: 10.1002/asia.202200223. Epub 2022 Apr 5.
Here, we report a medium-to-polymer anomalous chiral transfer in the supramolecular polymerization of a tetraphenylporphyrin-based achiral hydrogen-bonding monomer (TPP) in a chiral medium of 5-cyanobiphenyl CB*. A mixture of TPP in (R)-CB* ([TPP]=7.7 mol %) at 40 °C gave a columnar oblique LC mesophase, where the individual columns were composed of an optically active helical supramolecular polymer of TPP as a consequence of a successful medium-to-polymer chiral transfer. Meanwhile, upon dilution of CB* with achiral 5-cyanobiphenyl CB, the optical activity of the system showed an anomalous bell-shaped dependency on the composition of CB*/CB, where the g value of 0.049 at CB*/CB=50/50 was 6.0 times larger than the g value of CB* alone. Such anomalous chiroptical amplification in CD is most likely due to a change in the stacking geometry of TPP in the oblique columnar LC upon lateral compression.
在此，我们报道了在5-氰基联苯CB的手性介质中，基于四苯基卟啉的非手性氢键单体（TPP）的超分子聚合过程中发生的中等到聚合物的反常手性转移。40℃时，（R）-CB中TPP的混合物（[TPP]=7.7 mol %）形成柱状倾斜液晶中间相，由于成功实现了从介质到手性聚合物的手性转移，各个柱体由TPP的光学活性螺旋超分子聚合物组成。同时，用非手性的5-氰基联苯CB稀释CB时，体系的光学活性对CB/CB的组成呈现出反常的钟形依赖性，其中CB*/CB=50/50时g值为0.049，比单独的CB*的g值大6.0倍。圆二色性中这种反常的手性光学放大很可能是由于在横向压缩时倾斜柱状液晶中TPP堆积几何结构的变化所致。
