Dinitrogen complexes molybdenum

With the similar molybdenum complex the yield of ammonia reaches only ca 0.7 mol per metal atom, the remainder being evolved as free dinitrogen, with molybdenum being oxidized to molybdenum(III). Apparently, however, no such complexes have been observed as intermediates in dinitrogen reduction in protic media. 

The yields were found also to increase in the presence of phosphines, particularly trimethyl or tributyl phosphine. After all the improvements of the catalyst and reaction conditions the system became by far the most active of known non-biological catalytic systems for the reduction of dinitrogen at ambient temperature and pressure. The specific activity (the rate of N2 reduction per mole of the complex) reached and even exceeded that of nitrogenase. Up to 1000 turnovers relative to the molybdenum complex can be observed at atmospheric pressure and more than 10 000 turnovers at elevated N2 pressures. 

Keywords Dinitrogen complexes, Organo-nitrogen compounds, Nitrogen fixation, Molybdenum complexes, Tungsten complexes... 

Protonation of coordinated dinitrogen with dihydrogen mediated by sulfido-bridged dinuclear molybdenum complexes... 

A novel molybdenum (0) dinitrogen complex containing crown thioether as the sole auxiliary ligand trans-[Mo (N2) 2Me0 [16]aneS4]... 

Dinitrogen cleavage can also be accomplished in the coordination sphere of a molybdenum complex supported by the anionic POCOP pincer hgand... 

Broda H, Hinrichsen S, Tuczek F. Molybdenum(0) dinitrogen complexes with pol-ydentate phosphine Hgands for synthetic nitrogen fixation geometric and electronic structure contributions to reactivity. Coord Chem Rev. 2013 257 587-598. 

Guha AK, Phukan AK. Why vanadium complexes perform poorly in comparison to related molybdenum complexes in the catalytic reduction of dinitrogen to ammonia (Schrock cycle) a theoretical study. Inorg Chem. 2011 50 8826-8833. 

Weare WW, Schrock RR, Hock AS, Muller P. Synthesis of molybdenum complexes that contain hybrid triamidoamine ligands, [(hexaisopropylterphenyl-NCH2CH2)2 NCH2CH2N-aryl], and studies relevant to catalytic reduction of dinitrogen. Inorg Chem. 2006 45 9185-9196. 

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