Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering , Nagoya University , Furo-cho, Chikusa-ku , Nagoya , Aichi 464-8603 , Japan.
Graduate School of Engineering , Tohoku University , Sendai 980-8579 , Japan.
J Am Chem Soc. 2019 Dec 18;141(50):19807-19816. doi: 10.1021/jacs.9b09556. Epub 2019 Dec 5.
Establishing design principles to create nonplanar π-conjugated molecules is crucial for the development of novel functional materials. Herein, we describe the synthesis and properties of dinaphtho[1,8-:1',8'-]azepine bisimides (DNABIs). Their molecular design is conceptually based on the insertion of a nitrogen atom into a perylene bisimide core. We have synthesized several DNABI derivatives with a hydrogen atom, a primary alkyl group, or an aryl group on the central nitrogen atom. These DNABIs exhibit nonplanar conformations, flexible structural changes, and ambipolar redox activity. The steric effect around the central nitrogen atom substantially affects the overall structures and results in two different conformations: a nonsymmetric bent conformation and a symmetric twisted conformation, accompanied by a drastic change in electronic properties. Notably, the nonsymmetric DNABI undergoes unique structural changes in response to the application of an external electric field, which is due to molecular motions that are accompanied by an orientational fluctuation of the dipole moment. Furthermore, the addition of a chiral Brønsted base to -unsubstituted DNABI affords control over the helical chirality via hydrogen-bonding interactions.
建立设计原则以创造非平面π-共轭分子对于新型功能材料的发展至关重要。在此，我们描述了二萘并[1,8-:1',8'-]吖嗪双酰亚胺（DNABI）的合成和性质。它们的分子设计基于在苝二酰亚胺核心中插入一个氮原子。我们已经合成了几个在中心氮原子上具有氢原子、伯烷基或芳基的 DNABI 衍生物。这些 DNABI 表现出非平面构象、灵活的结构变化和双极氧化还原活性。中心氮原子周围的空间效应显著影响整体结构，导致两种不同的构象：不对称弯曲构象和对称扭曲构象，同时电子性质发生剧烈变化。值得注意的是，非对称 DNABI 对外加电场的响应会发生独特的结构变化，这是由于分子运动伴随着偶极矩的取向波动。此外，向未取代的 DNABI 添加手性布朗斯台德碱通过氢键相互作用可以控制螺旋手性。
