Remarkable catalytic activity of dinitrogen-bridged dimolybdenum complexes bearing NHC-based PCP-pincer ligands toward nitrogen fixation

作者：Aya Eizawa, Kazuya Arashiba, Hiromasa Tanaka, Shogo Kuriyama, Yuki Matsuo, Kazunari Nakajima, Kazunari Yoshizawa, Yoshiaki Nishibayashi · 发表于：Nature Communications · 年份：2017 · DOI：10.1038/ncomms14874 · 被引用次数：263 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、N-Heterocyclic Carbenes in Organic and Inorganic Chemistry、Asymmetric Hydrogenation and Catalysis

Abstract 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 bearingN-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 on1reveal that the PCP-pincer ligand serves as not only a strongσ-donor but also aπ-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.