The mechanism of the secondary alkylation of dinitrogen and the relationship between structure and reactivity in the alkylation of co-ordinated dinitrogen

Dinitrogen loss from a range of bis(N2)-complexes of Mo and W is the common rate-determining step in the primary alkylation of the remaining co-ordinated N2, whereas the second alkylation of co-ordinated N2 is a typical SN2 reaction; the rates of these reactions are sensitive to both the metal and the coligands, and those factors which encourage the first alkylation are those which inhibit the second.