Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
J Am Chem Soc. 2011 Sep 14;133(36):14172-5. doi: 10.1021/ja203648w. Epub 2011 Aug 19.
The mechanism of formation of ammonia borane (NH(3)BH(3), AB) and the diammoniate of diborane ([H(2)B(NH(3))(2)][BH(4)], DADB) in the reaction between NH(3) and THF·BH(3) was explored experimentally and computationally. Ammonia diborane (NH(3)BH(2)(μ-H)BH(3), AaDB), a long-sought intermediate proposed for the formation of DADB, was directly observed in the reaction using (11)B NMR spectroscopy. The results indicate that dihydrogen bonds between the initially formed AB and AaDB accelerate the formation of DADB in competition with the formation of AB.
实验和计算研究了氨硼烷(NH(3)BH(3),AB)和二氨合硼烷([H(2)B(NH(3))(2)][BH(4)],DADB)在氨和四氢呋喃·硼烷(THF·BH(3))反应中的形成机制。使用(11)B NMR 光谱,直接观察到在反应中形成的氨二硼烷(NH(3)BH(2)(μ-H)BH(3),AaDB),这是形成 DADB 的长期以来提出的中间产物。结果表明,最初形成的 AB 和 AaDB 之间的氢键加速了 DADB 的形成,与 AB 的形成竞争。