(Electro)chemical N 2 Splitting by a Molybdenum Complex with an Anionic PNP Pincer-Type Ligand

• Published in: ACS Organic & Inorganic Au 2024-06, Vol.4 (3), p.329
• Main Authors: Ostermann, Nils, Rotthowe, Nils, Stückl, A Claudia, Siewert, Inke
• Format: Article
• Language: English
• ISSN: 2694-247X; 2694-247X
• DOI: 10.1021/acsorginorgau.3c00056

Molybdenum(III) complexes bearing pincer-type ligands are well-known catalysts for N -to-NH reduction. We investigated herein the impact of an anionic PNP pincer-type ligand in a Mo(III) complex on the (electro)chemical N splitting ([ MoCl ] , , H = 2,6-bis((di- -butylphosphaneyl)methyl)-pyridin-4-one). The increased electron-donating properties of the anionic ligand should lead to a stronger degree of N activation. The catalyst is indeed active in N -to-NH conversion utilizing the proton-coupled electron transfer reagent SmI /ethylene glycol. The corresponding Mo(V) nitrido complex exhibits similar catalytic activity as and thus could represent a viable intermediate. The Mo(IV) nitrido complex is also accessible by electrochemical reduction of under a N atmosphere. IR- and UV/vis-SEC measurements suggest that N splitting occurs via formation of an "overreduced" but more stable [( (N ) Mo ) μ-N ] dimer. In line with this, the yield in the nitrido complex increases with lower applied potentials.