An air-stable B₃,N₃-containing dibenzobisanthene (8) was prepared in 29% yield by heating a 1,3,5-tri(azasilaanthryl)benzene (5) with BBr₃ (180 °C). Under these conditions, the reaction does not stop after threefold SiMe₂/BBr exchange but proceeds further via two rearrangement and two intramolecular C–H borylation steps. Some mechanistic details were unveiled by using smaller model systems and applying lower reaction temperatures. According to X-ray crystallography, compound 8 has a helically distorted scaffold. Due to its multiple resonance structure, it shows a narrow-band blue-green emission (λ_em = 493 nm; Φ_PL = 84%; FWHM = 0.20 eV; THF); samples measured in PMMA gave prompt and delayed fluorescence lifetimes of 10.7 ns and 136 μs, respectively. The optical properties of 8 and of structurally related species were also investigated by quantum-chemical means: most of these compounds exhibit a small energy gap ΔE_ST between the lowest excited singlet (S₁) and triplet (T₁) states and a non-negligible spin–orbit coupling (SOC) between S₁ and T₁/T₂, demonstrating their potential as thermally activated delayed fluorescence (TADF) emitters.

中文翻译：

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氮杂硅蒽的硼化和重排反应制备 B,N 掺杂纳米石墨烯


通过加热 1,3,5-三(氮杂硅蒽基)苯 (5) 制备空气稳定的含 B ₃ ,N ₃ 的二苯并联蒽 (8)，收率 29%与 BBr ₃ (180 °C)。在这些条件下，反应在三次 SiMe ₂ /BBr 交换后不会停止，而是通过两次重排和两次分子内 C-H 硼化步骤进一步进行。通过使用较小的模型系统和应用较低的反应温度揭示了一些机械细节。根据X射线晶体学，化合物8具有螺旋扭曲的支架。由于其多重共振结构，它显示出窄带蓝绿发射（λ _em = 493 nm；Φ _PL = 84%；FWHM = 0.20 eV；THF）；在 PMMA 中测量的样品的瞬时荧光寿命和延迟荧光寿命分别为 10.7 ns 和 136 μs。 8 和结构相关物质的光学性质也通过量子化学手段进行了研究：大多数这些化合物在最低激发单线态（S ₁ ) 和三重态 (T ₁ ) 态以及 S ₁ 和 T ₁ /T ₂