Catalytic Reduction of Dinitrogen

The catalytic reduction of dinitrogen to ammonia in biological systems is thermodynamically favorable overall and takes place according to equation 6.2 ... 

A series of model studies initiated in the early 1960s by the groups of Chatt and Hidai demonstrated that dinitrogen could be bound and reduced to ammonia at a single metal centre by Mo and W complexes (Chatt et al., 1978 Hidai, 1999). However, although examples of virtually all the proposed intermediates in a Chatt cycle were isolated, no catalytic reduction of N2 to NH3 was ever achieved. Catalytic reduction of dinitrogen to ammonia... 

Structural basis of biological nitrogen fixation, Phil. Trans. R. Soc., 363, 971-984. Schrock, R.R. (2005) Catalytic reduction of dinitrogen to ammonia at a single molybdenum center,... 

Scheme 18. Proposed mechanism for catalytic reduction of dinitrogen by Mo(red). ...

Scheme 1. Proposed mechanism for the catalytic reduction of dinitrogen at a molybdenum site in nitrogenase...

Studies on model polynuclear catalytic systems have confirmed that for the catalytic reduction of dinitrogen under mild conditions, it is necessary to use a polynuclear transition metal complex capable of donating four electrons to form the hydrazine derivative. 

Dmitry V. Yandulov and Richard R. Schrock Catalytic reduction of dinitrogen to ammonia at a single Mo center... 

HlPTNsN] species can be prepared for Cr [68]. Attempted catalytic reduction of dinitrogen under standard conditions with [HlPTN3N]Cr=N yields only 0.8 equiv... 

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. 

Schrock RR. Catalytic reduction of dinitrogen to ammonia by molybdenum theory versus experiment. Angew Chent Int Ed. 2008 47 5512-5522. 

Rideng V, Yandulov DV, Weare WW, Schrock RR, Hock AS, Davis WM. Molybdenum triamidoamine complexes that contain hexa-tert-butyltetphenyl, hexamethylterphenyl, or p-bromohexaisopropylterphenyl substiments. An examination of some catalyst variations for the catalytic reduction of dinitrogen. J Am Chem Soc. 2004 126 6150-6163. 

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. 

Arashiba K, Miyake Y, Nishibayashi Y. A molybdenum complex bearing PNP-type pincer ligands leads to the catalytic reduction of dinitrogen into ammonia. Nat Chem. 2011 3 120-125. 

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