Aizawa Hiroki, Sato Takuro, Maki-Yonekura Saori, Yonekura Koji, Takaba Kiyofumi, Hamaguchi Tasuku, Minato Taketoshi, Yamamoto Hiroshi M
Institute for Molecular Science, Myodaiji, Okazaki, 444-8585, Japan.
the Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585, Japan.
Nat Commun. 2023 Jul 28;14(1):4530. doi: 10.1038/s41467-023-40133-z.
Enantioselectivity of helical aggregation is conventionally directed either by its homochiral ingredients or by introduction of chiral catalysis. The fundamental question, then, is whether helical aggregation that consists only of achiral components can obtain enantioselectivity in the absence of chiral catalysis. Here, by exploiting enantiospecific interaction due to chiral-induced spin selectivity (CISS) that has been known to work to enantio-separate a racemic mixture of chiral molecules, we demonstrate the enantioselectivity in the assembly of mesoscale helical supramolecules consisting of achiral cobalt phthalocyanines. The helical nature in our supramolecules is revealed to be mesoscopically incorporated by dislocation-induced discretized twists, unlike the case of chiral molecules whose chirality are determined microscopically by chemical bond. The relevance of CISS effect in the discretized helical supramolecules is further confirmed by the appearance of spin-polarized current through the system. These observations mean that the application of CISS-based enantioselectivity is no longer limited to systems with microscopic chirality but is expanded to the one with mesoscopic chirality.
螺旋聚集的对映选择性传统上是由其同手性成分或通过引入手性催化来引导的。那么，根本问题在于，仅由非手性成分组成的螺旋聚集在没有手性催化的情况下能否获得对映选择性。在此，通过利用已知可用于对映分离手性分子外消旋混合物的手性诱导自旋选择性（CISS）引起的对映特异性相互作用，我们证明了由非手性钴酞菁组成的介观螺旋超分子组装中的对映选择性。我们超分子中的螺旋性质被揭示为通过位错诱导的离散扭曲在介观层面上整合而成，这与手性分子的情况不同，手性分子的手性是由化学键在微观层面上决定的。通过系统的自旋极化电流的出现进一步证实了CISS效应在离散螺旋超分子中的相关性。这些观察结果意味着基于CISS的对映选择性的应用不再局限于具有微观手性的系统，而是扩展到具有介观手性的系统。
