Légaré Marc-André, Rang Maximilian, Bélanger-Chabot Guillaume, Schweizer Julia I, Krummenacher Ivo, Bertermann Rüdiger, Arrowsmith Merle, Holthausen Max C, Braunschweig Holger
Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Institute for Sustainable Chemistry and Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Science. 2019 Mar 22;363(6433):1329-1332. doi: 10.1126/science.aav9593. Epub 2019 Mar 21.
The coupling of two or more molecules of dinitrogen (N) occurs naturally under the radiative conditions present in the ionosphere and may be achieved synthetically under ultrahigh pressure or plasma conditions. However, the comparatively low N-N single-bond enthalpy generally renders the catenation of the strongly triple-bonded N diatomic unfavorable and the decomposition of nitrogen chains a common reaction motif. Here, we report the surprising organoboron-mediated catenation of two N molecules under near-ambient conditions to form a complex in which a [N] chain bridges two boron centers. The reaction entails reductive coupling of two hypovalent-boron-bound N units in a single step. Both this complex and a derivative protonated at both ends of the chain were characterized crystallographically.
两个或多个双氮（N₂）分子的偶联在电离层存在的辐射条件下自然发生，并且在超高压或等离子体条件下也可以通过合成方法实现。然而，相对较低的N-N单键焓通常使得强三键连接的N₂双原子的成链不利，并且氮链的分解是常见的反应模式。在此，我们报道了在接近环境条件下两个N₂分子由有机硼介导的令人惊讶的成链反应，形成了一种配合物，其中一条[N]链桥连两个硼中心。该反应涉及一步中两个低价硼结合的N单元的还原偶联。通过晶体学表征了这种配合物以及在链的两端均质子化的衍生物。
