Dinitrogen activation

Geometric and electronic factors of dinitrogen activation on transition metal complexes. P. Pelikan and R. Boca, Coord. Chem. Rev., 1984, 55, 55-112 (190). 

Active catalysts for dinitrogen activation have been prepared by reduction at a mercury pool of M0CI5 in basic methanolic solutions containing MgCl2, phospholipids, and various tertiary phosphines.319 The turnover number reached several hundreds per Mo center. Both ammonia and hydrazine were formed in a ratio of about 1 10. 

Electroreduction of N2 to NH3 has also been examined using gas-diffusion electrodes modified by 14 different metal phthalocyanines.320 It was found that the Sn-Pc complex is the best catalyst in terms of current efficiency and stability of the electrode for the electrochemical dinitrogen activation. 

Leigh32 has discussed chemical systems for dinitrogen activation and reduction... 

The non-classical divalent lanthanide complexes have stronger reducing power than divalent samarium complexes because of their higher reduction potentials. Dinitrogen is not an inert atmosphere for these non-classical divalent lanthanide complexes. Therefore, attempts to prepare non-classical divalent organolanthanide complexes by metathesis reactions in dinitrogen atmosphere have been unsuccessful, and the dinitrogen-activated products were isolated. A typical example is shown in Equation 8.36 [112]. 

Dinitrogen Activation by Early Transition Metal-Amido Phosphine Complexes... 

N-N triple bond cleavage has always been assumed as a sort of a dream in dinitrogen activation, due to the major practical use of N2 in producing ammonia, and to the fact that in the actual use of heterogeneous catalysts the formation of nitrides is unanimously considered as the intermediate step in the formation of NH3 by dinitrogen hydrogenation. ... 

So far, studies on the reactivity of the divalent complexes mentioned above in Section 2.3 have been very limited. Dinitrogen activation has been observed not only for isolated divalent complexes but also for systems containing divalent species or trivalent rare earths in the presence of reducing agents, thus displaying divalent-like behaviour this important topic will be developed later in Section 2.3.4. 

It appears that dinitrogen activation is also possible with systems involving divalent ions and non-cyclopentadienyl ligands. Thus, the reaction of Tml2 or with KN(SiMe3)2 in TFIE at low temperature afforded... 

The first experiments involving dinitrogen activation by praseodymium and neodymium were described by Floriani et al. in 1998 (Campazzi et al., 1998). When the anionic [Na(THF)3(Et8-calix[4]tetrapyrrolyl)R(THF)] (R = Pr, Nd) were reacted with sodium naphthalenide in THF under dinitrogen, dimeric products featuring the p — -bridging ligand were isolated. Their general... 

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