Syntheses, structures and electrochemistry of some 1-(η2-allylamino)-1-ferrocenylcarbene complexes of chromium(0), molybdenum(0) and tungsten(0)

The bimetallic chelated complexes (OC)4MC(η2-NHCH2CHCHX)Fc 4/5 [M = Cr: a; Mo: b; W: c; Fc = CpFe(C5H4)] were obtained by photo-decarbonylation/alkene ligation of the unchelated precursor carbene complexes (OC)5MC(NHCH2CHCHX)Fc (2; X = H)/(3; X = CH2OH). The latter exist as mixtures of E- and predominantly Z-isomers. The molecular structures of 4b and 4c were determined by X-ray single-crystal diffraction analyses. The intermetallic communicative effects and the interplay of Fc and η2-alkene moieties of 4a and 4b were assessed by cyclovoltammetry.