Nitrogen Reduction to Ammonia by a Phosphorus-Nitrogen PN3P-Mo(V) Nitride Complex: Significant Enhancement via Ligand Postmodification

by Delong Han, Priyanka Chakraborty, Mei-Hui Huang, Li Yang, Hao Huang, Théo P. Gonçalves, Abdul Hamid Emwas, Zhiping Lai, Jr-Hau He, Aleksander Shkurenko, Mohamed Eddaoudi, Kuo-Wei Huang
Year: 2023 DOI:


Efforts to develop organometallic complexes for catalytic nitrogen reduction have seen significant progress in recent years. However, the strategies for improving the activity of the homogenous catalysts have mainly focused on alternating ligands and metals. Herein, we report that the activity and stability of a PN3P-Mo pincer complex ( ) toward dinitrogen (N2) reduction were greatly enhanced through postmodification of the PN3P pincer framework of its parent complex ( ). A high ratio of NH3/Mo (3525) was achieved in the presence of SmI2 as a reductant. In sharp contrast,  only afforded an NH3/Mo ratio of 21. Moreover, when supported by an anionic pincer ligand,  furnished a high oxidation state Mo(V)-nitride complex via N2 cleavage as a plausible key intermediate in the catalytic process, suggesting a catalytic cycle that may involve different oxidation states (II/V) from those with 10-π electron configuration in the literature.