Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Science. 2018 Feb 23;359(6378):896-900. doi: 10.1126/science.aaq1684.
Currently, the only compounds known to support fixation and functionalization of dinitrogen (N) under nonmatrix conditions are based on metals. Here we present the observation of N binding and reduction by a nonmetal, specifically a dicoordinate borylene. Depending on the reaction conditions under which potassium graphite is introduced as a reductant, N binding to two borylene units results in either neutral (BN) or dianionic ([BN]) products that can be interconverted by respective exposure to further reductant or to air. The N isotopologues of the neutral and dianionic molecules were prepared with N-labeled dinitrogen, allowing observation of the nitrogen nuclei by N nuclear magnetic resonance spectroscopy. Protonation of the dianionic compound with distilled water furnishes a diradical product with a central hydrazido BNH unit. All three products were characterized spectroscopically and crystallographically.
目前，已知在非基质条件下支持二氮（N）固定和功能化的唯一化合物基于金属。在这里，我们观察到一种非金属，即二配位硼烯，对 N 的结合和还原。具体来说，取决于钾石墨作为还原剂引入的反应条件，N 与两个硼烯单元结合会导致中性（BN）或二阴离子（[BN]）产物，这些产物可以通过分别暴露于更多还原剂或空气来相互转化。中性和二阴离子分子的 N 同位素标记是用 N 标记的二氮制备的，允许通过 N 核磁共振波谱观察氮核。用蒸馏水质子化二阴离子化合物会生成带有中心肼基 BNH 单元的双自由基产物。所有三种产物均通过光谱和晶体学进行了表征。
