Lithiation of ferrocenylamines and vanadium dinitrogen chemistry

The lithiation of ferrocenylamines [Fe(C5H5)(C5H4CH2R)] (R=NMe2, NEt2, CH2NMe2, NC4H8O or NMeCH2Ph) with organolithium reagents does not proceed with clean reaction at position 2 of the ring. Generally a range of products is formed, these sometimes difficult to separate. The electronic condition of the iron in these complexes as tested by Mössbauer spectroscopy and electrochemistry, does not differ much between compounds. The crystal structures of several methylated derivatives of the ferrocenylamines are reported. All the ferrocenylamines seem to potentiate vanadium(II) to dinitrogen uptake, but the precise nature of the dinitrogen species formed could not be determined.