Unravelling the potential of low-valent tunable vanadium complexes in the nitrogen reduction reaction (NRR)

Density functional theory calculations have been carried out to investigate the potential of several hitherto unknown low-valent tripodal vanadium complexes towards conversion of dinitrogen to ammonia as a function of different equatorial (PⁱPr₂ and SⁱPr) and bridgehead groups (B, C and Si). All the newly proposed vanadium complexes were probed towards understanding their efficiency in some of the key steps involved in the dinitrogen fixation process. They were found to be successful in preventing the release of hydrazine during the nitrogen reduction reaction. We have performed a comprehensive mechanistic study by considering all the possible pathways (distal, alternate and hybrid) to understand the efficiency of some of the proposed catalysts towards the dinitrogen reduction process. The exergonic reaction free energies obtained for some of the key steps and the presence of thermally surmountable barrier heights involved in the catalytic cycle indicate that these complexes may be considered as suitable platforms for the functionalization of dinitrogen.