The reactions of [M(N2)2(dppe)2][M = MO or W; dppe = 1,2-bis(diphenylphosphino)ethane] with alkyl bromides, acyl chlorides, or aroyl chlorides, under irradiation, lead to organohydrazido(2–)- and organodiazenido-complexes. Complexes [ReCl(N2)(PMe2Ph)4] and [ReCl(N2)(py)(PMe2Ph)3](py = pyridine) can be acylated but not alkylated at the dinitrogen, but in [OsCl2(N2)(PMe2Ph)4] dinitrogen is inactive even to acid chlorides. The reactivity of dinitrogen in its complexes decreases along the third Transition Series in the order W > Re > Os.