The Reactivity of Transition Metal Complexes with Dinitrogen

2 THE REACTIVITY OF TRANSITION METAL COMPLEXES WITH DINITROGEN 

Interest in metal complexes able to bind molecular dinitrogen is mainly due to a desire to understand and reproduce in the laboratory the so-called nitrogen fixation reaction. This process, which in nature is catalysed by the metalloprotein nitrogenases, reduces the inert dinitrogen molecule to the metabolically useful NH3  

The electrons required for this reduction process are provided in vivo by electron carriers such as ferredoxins (see Chapter 12, Section 3), whereas in vitro they can be provided by reducing agents such as dithionite. 

To appreciate the height of the activation barrier that the biological catalysts are able to overcome one can recall that the Haber-Bosch process  

To date, three types of nitrogenases have been identified, namely FeMo-, FeV- and FeFe- nitrogenases, depending upon the metal (in addition to iron) present in their cofactor. 

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