Helix-Sense-Selective Synthesis of Right- and Left-Handed Helical Luminescent Poly(diphenylacetylene)s with Memory of the Macromolecular Helicity and Their Helical Structures
Helix-Sense-Selective Synthesis of Right- and Left-Handed Helical Luminescent Poly(diphenylacetylene)s with Memory of the Macromolecular Helicity and Their Helical Structures
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DOI：
10.1021/jacs.0c02542
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发表时间：
2020-04-22
影响因子：
15
通讯作者：
Yashima, Eiji
中科院分区：
文献类型：
--
作者：
Maeda, Katsuhiro;Nozaki, Mai;Yashima, Eiji
含有羧基侧链的对称取代聚二苯乙炔(PDPA)在水中与非外消旋胺热处理后折叠成单手螺旋，并伴随着螺旋度的手性放大。在完全去除手性胺后，诱导的右旋或左旋螺旋PDPA被保留(记忆)，从而以螺旋选择性的方式产生单手螺旋圆偏振发光PDPA。具有静态螺旋度记忆的螺旋PDPA对羧基侧基的修饰具有容忍性，提供了仅由于大分子螺旋性而具有旋光性的功能性PDPA。PDPA及其衍生物在单手螺旋度诱导前后以及随后的螺旋度记忆中表现出很好的分辨率，非常简单的H-1和C-13核磁共振和拉曼光谱，其光谱模式实际上是相同的，而不受螺旋度偏差的影响。根据H-1和C-13核磁共振、红外光谱、拉曼光谱、振动和电子圆二色谱的测量结果，结合理论计算，确定了PDPA的主要结构特征(顺式或反式、顺式或跨体)及其螺旋反转势垒和绝对利手性(右旋或左旋螺旋)以及具有静态螺旋度记忆的单手螺旋PDPA及其衍生物的螺旋过量。结果，利用非共价螺旋度诱导和记忆策略，成功地获得了几乎完全的右旋和左旋螺旋顺式跨体PDPA，螺旋长度超过98%。
Symmetrically substituted poly(diphenylacetylene) (PDPA) bearing carboxy pendants was found to fold into a one-handed helix upon thermal annealing with nonracemic amines in water accompanied by chiral amplification of the helicity. The induced right- or left-handed helical PDPA was retained (memorized) after complete removal of the chiral amines, thus producing a one-handed helical circularly polarized luminescent PDPA in a helix-sense-selective manner. The helical PDPA with static helicity memory is tolerant toward modification of carboxy pendants, providing functional PDPAs with an optical activity solely due to macromolecular helicity. The PDPA and its derivatives before and after the one-handed helicity induction and its subsequent memory of the helicity exhibited well-resolved very simple H-1 and C-13 NMR and Raman spectra whose spectral patterns are virtually identical independent of the helical sense bias. On the basis of the H-1 and C-13 NMR, IR, Raman, and vibrational and electronic circular dichroism spectral measurement results combined with theoretical calculations, the key structural features (cis or trans and cisoid or transoid) of the PDPA as well as its helix inversion barrier and absolute handedness (right- or left-handed helix) and helix-sense excess of the one-handed helical PDPA and its derivatives with static helicity memory were determined. As a result, almost complete right- and left-handed helical cis-transoidal PDPAs with 98% helix-sense excess were successfully obtained using noncovalent helicity induction and memory strategy.