Diborepins: New Classes of Heteroaromatic Building Blocks for Extended Conjugated Materials

1，2，7-氮杂二烯类化合物是一类具有6个pi电子的新型杂环化合物。二硫杂环1，2，7-氮杂二氮杂环化合物与联噻吩亚胺(BTI)的结构和电子结构有关，BTI是一种公认的n型半导体材料的缺电子有机构建块。在后者的基础上，新设计的三环有机硼化合物是通过用强吸电子的棒-NR-棒部分取代二羧亚胺基团而得到的。这为通过硼上的可变取代基(Ar)微调它们的性质提供了额外的机会。本项目的目的是开发具有不同杂原子(E=O，P，S)的1，2，7-氮杂二氢呋喃和其他类型的新型双氢呋喃，它们的B-E-B单元中有或没有进一步融合的芳环。详细的实验和理论研究将提供对其组成环的芳香性的基本见解。预期的二硼杂环的弱芳香性应能提供足够的稳定性，同时确保与相邻的圆周率体系的有效共轭。通过将新型杂环构建块结合到包括共轭聚合物、低聚物和大环在内的扩展框架中，将瞄准具有特定特性和功能的各种基于diborepin的材料。在梯形齐聚物和半聚合聚合物中的加入有望赋予更多的稳定性，并导致改性的固态填充基元。将探索新材料的光电特性以及传感能力和可能的主-客相互作用。

1,2,7-Azadiborepins constitute a new class of heteroaromatic compounds with six pi electrons. Dithieno-fused 1,2,7-azadiborepins are structurally and electronically related to bithiophene imide (BTI), a well-established electron-deficient organic building block for n-type semiconducting materials. From the latter, the newly devised tricyclic organoboron compounds are formally derived by the substitution of a strongly electron-withdrawing BAr-NR-BAr moiety for the dicarboximide group. This offers the additional opportunity of fine-tuning their properties through the variable substituents (Ar) on boron. The aim of this project is to develop 1,2,7-azadiborepins and further classes of novel diborepins with different heteroatoms (E = O, P, S) in their B-E-B unit and with or without further aromatic rings fused. Detailed experimental and theoretical studies will provide fundamental insight into the aromatic character of their constituent rings. The anticipated weak aromaticity of the diboron heterocycles should confer sufficient stability while ensuring effective conjugation with the adjacent pi systems. A variety of diborepin-based materials with specifically tailored properties and functions will be targeted by incorporating the novel heterocyclic building blocks into extended frameworks including conjugated polymers, oligomers, and macrocylces. Incorporation into ladder oligomers and semiladder polymers is expected to impart substantial additional stability and lead to modified solid-state packing motifs. The optoelectronic properties of the new materials as well as sensory capabilities and possible host-guest interactions will be explored.