Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Angew Chem Int Ed Engl. 2021 Sep 20;60(39):21289-21294. doi: 10.1002/anie.202109326. Epub 2021 Aug 20.
Replacement of the allylic C=C-C unit with a N-B-N unit at each of the three zigzag edges of [4]triangulene gives rise to B N -[4]triangulene, which is envisioned to represent a key structural unit of a new hypothetical boron carbon nitride (BC N). A tert-butylated B N -[4]triangulene has been successfully synthesized by three-fold nitrogen-directed borylation, and the X-ray crystallographic analysis indicates that its slightly bent triangular polycyclic framework can be viewed as a 1,3,5-triphenylbenzene connected by three 4π-electron N-B-N units. The HN-B-NH moiety provides a dual hydrogen-bond donor, which forms H-bonds with halide or carboxylate anions in solution, and form DD-AA hydrogen-bond arrays with 2,7-di(tert-butyl)-pyrene-4,5,9,10-tetraone in the co-crystal. Moreover, the blue fluorescence of B N -[4]triangulene in solution is responsive to binding p-nitrobenzoate anion through hydrogen bonds.
在[4]三角烯的三个之字形边缘的每个位置用 N-B-N 单元替换烯丙基 C=C-C 单元，得到 BN-[4]三角烯，它被设想为代表新的假设硼碳氮化物（BCN）的关键结构单元。通过三倍氮导向硼化成功合成了叔丁基 BN-[4]三角烯，X 射线晶体结构分析表明，其略微弯曲的三角多环骨架可视为由三个 4π 电子 N-B-N 单元连接的 1,3,5-三苯基苯。HN-B-NH 部分提供了双氢键供体，它在溶液中与卤化物或羧酸盐阴离子形成氢键，并在共晶中与 2,7-二（叔丁基）-芘-4,5,9,10-四酮形成 DD-AA 氢键阵列。此外，溶液中 BN-[4]三角烯的蓝色荧光通过氢键响应与对硝基苯甲酸根阴离子的结合。
