title: Remarkable catalytic activity of dinitrogen-bridged dimolybdenum complexes bearing NHC-based PCP-pincer ligands toward nitrogen fixation.
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 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.
authors.affiliation: Department of Systems Innovation, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Aya
authors.identifier: 0000-0001-6713-1871
authors.initials: A
authors.lastname: Eizawa
authors.affiliation: Department of Systems Innovation, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Arashiba
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Systems Innovation, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Kuriyama
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Matsuo
authors.affiliation: Department of Systems Innovation, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Institute for Materials Chemistry and Engineering, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan.|Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, Nishikyo-ku, Kyoto 615-8520, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Yoshizawa
authors.affiliation: Department of Systems Innovation, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Yoshiaki
authors.identifier: 0000-0001-9739-9588
authors.initials: Y
authors.lastname: Nishibayashi