Dinitrogen complexes tungsten

The electrocatalytic properties of several parent dinitrogen or hydrazido-containing molybdenum and tungsten complexes with dppe ligand have also been investigated. Each of these complexes yielded NH3, in chemical yields which ranged from 1% to 36% per mole of complex.318... 

Only one nitrido Ww complex has been documented. This was prepared by the action of Me3SiN3 followed by oxidation on dinitrogen W° complex 83 (Eq. (31)) [36]. It has been proposed that the reaction of 83 with trimethylsilylazide affords a Wn complex bearing two N3-ligands a subsequent two-electron oxidation of the metal center then affords nitrido tungsten complex 84. 

Hidai, M. Mizobe, Y. Chemical dinitrogen fixation by molybdenum and tungsten complexes insights from coordination chemistry. In Metal Ions in Biological Systems Sigel, A., Sigel, H., Eds. Marcel Dekker New York, 2002 Vol. 39, pp. 121-186. 

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

However, this work pre-dated the discovery of protonation of dinitrogen in the molybdenum and tungsten complexes and, once this had come to light, we turned our attention to the behaviour of isocyanides and alkynes at those sites that activated dinitrogen to reduction. For isocyanides, the first step was to bind these ligands in place of dinitrogen in the complexes trflns-[M(N2)2(dppe)2], which was done by a displacement reaction [Equation (23)]. ... 

We also employed other ruthenium dihydrogen complexes for the protonation of the coordinated dinitrogen in complex (2b). Typical results are shown in Table 3 [21]. Ammonia is formed in higher yields (up to 79% based on tungsten) when dinitrogen complex (2b) is similarly treated with tra s-[RuCl(r -H2)(dppe)2]X... 

Chemical Dinitrogen Fixation by Molybdenum and Tungsten Complexes Insights from Coordination Chemistry Masanobu Hidai and Yasushi Mizobe... 

Properties of Molybdenum and Tungsten Na, NNH, NNHa, and NNH3 Complexes with Diphosphine Co-Ligands Insights into the End-on Terminal Reduction Pathway of Dinitrogen Felix Tuczek... 

---