Remarkable catalytic activity of dinitrogen-bridged dimolybdenum complexes bearing NHC-based PCP-pincer ligands toward nitrogen fixation.
Remarkable catalytic activity of dinitrogen-bridged dimolybdenum complexes bearing NHC-based PCP-pincer ligands toward nitrogen fixation.
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DOI：
10.1038/ncomms14874
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发表时间：
2017-04-04
影响因子：
16.6
通讯作者：
Nishibayashi Y
中科院分区：
文献类型：
--
作者：
Eizawa A;Arashiba K;Tanaka H;Kuriyama S;Matsuo Y;Nakajima K;Yoshizawa K;Nishibayashi Y
在温和的反应条件下，利用过渡金属-二氮络合物作为催化剂转化二氮已经做了大量的努力。然而，在氨的催化形成中，有限的系统已经成功。在这里，我们表明，新设计和制备的带有N-杂环卡宾和膦基PCP钳形配体的二氮桥连二钼配合物[{Mo（N2）2（PCP）}2（μ-N2）]（1）是迄今为止在环境反应条件下由二氮形成氨的最有效的催化剂，其中高达230当量。的氨是基于该催化剂产生的。对1的DFT计算表明，PCP钳形配体不仅是强的σ-给体，而且是强的π-受体。这些电子性质负责钼中心和钳形配体之间的固体连接，从而提高了固氮的催化活性。由于需要开发温和的氨生产路线，催化固氮是一个非常活跃的研究领域。在这里，作者报告了PCP-钳状钼络合物，其允许在环境条件下高效地产生氨。
Intensive efforts for the transformation of dinitrogen using transition metal–dinitrogen complexes as catalysts under mild reaction conditions have been made. However, limited systems have succeeded in the catalytic formation of ammonia. Here we show that newly designed and prepared dinitrogen-bridged dimolybdenum complexes bearing N-heterocyclic carbene- and phosphine-based PCP-pincer ligands [{Mo(N2)2(PCP)}2(μ-N2)] (1) work as so far the most effective catalysts towards the formation of ammonia from dinitrogen under ambient reaction conditions, where up to 230 equiv. of ammonia are produced based on the catalyst. DFT calculations on 1 reveal that the PCP-pincer ligand serves as not only a strong σ-donor but also a π-acceptor. These electronic properties are responsible for a solid connection between the molybdenum centre and the pincer ligand, leading to the enhanced catalytic activity for nitrogen fixation. Catalytic nitrogen fixation is a very active research area, given the need to develop mild routes for ammonia production. Here the authors report a PCP-pincer molybdenum complex allowing for highly efficient ammonia generation under ambient conditions.