Magnesium dinitrogen complexes

Our scheme calls for the preparation of coordinatively unsaturated, or at least substitution labile, cobalt complexes that will bind O2. Reduction of halide precursor TpCo-I with magnesium metal under N2 yielded the corresponding dinitrogen complexes, see eq. 2.[8,9]... 

We found these conditions by introducing surface-active materials to a solution of a specially prepared catalytic complex containing molybdenum and stabilized by magnesium ions [22]. The structure of the complex which was isolated from the solution in its oxidized form is presented on Figure 5 [23]. When it is reduced to the Mo state the complex becomes an active catalyst of dinitrogen reduction to hydrazine and ammonia by sodium amalgam. Phospholipid (phosphatidylcholine)... 

Relatively few compounds of this type exist. Only two simple alkene Ti-complexes are known, both prepared from the cobalt(I) complex Tp Co(N2) (19, obtained by magnesium reduction of Tp CoX (X = Cl, I) under dinitrogen)with excess H2C = CHR (R = H, CH3 Scheme 1). The ethylene complex 20 was readily isolated from solution at —30 °C, while the propene analogue 21 was only observed spectroscopically, since it proved unstable toward loss of propene upon removal of excess alkene and exposure to N2, leading to the regeneration of 19. This lability of the propene ligand was attributed to the significant steric hindrance imposed by the... 

Yamamoto A, Miura Y, Ito T, et al. Preparation, x-ray molecular structure determination, and chemical properties of dinitrogen-coordinated cobalt complexes containing triphenylphosphine ligands and alkali metal or magnesium. Protonation of the coordinated dinitrogen to ammonia and hydrazine. Organometallics. 1983 2 1429-1436. 

Dugan TR, MacLeod KC, Brennessel WW, Holland PL. Cobalt-magnesium and iron-magnesium complexes with weakened dinitrogen bridges. Eur J Inorg Chem. 2013 3891-3897. 

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