The synthesis and X-ray crystal structure of [(4-ferrocenylphenylimido)]trichlorobis(triphenylphosphine)rhenium(V) and related ferrocenyl-rhenium(V) compounds

The reaction of 4-ferrocenylaniline with trans-[ReOCl3(PPh3)(2)] gave [(4-f errocenylphenylimido)]trichlorobis(triphenylphosphine) rhenium(V) (1). The molecular structure of 1 has been determined by X-ray diffraction. The X-ra y crystal structure of [(4-ferrocenylphenylimido)]tribromobis(triphenylphos phine) rhenium(V) (2) has also been determined and its molecular structure is compared with that of 1. The complexes 1 and 2 have also been investigat ed by cyclic voltammetry and UV-visible spectroscopy. The results of the cy clic voltammetry suggest that there is insignificant electron delocalizatio n from the ferrocenyl group towards rhenium in 1 and 2. However, both 1 and 2 show a long wavelength absorption in their electronic spectra which is c haracteristic of conjugated ferrocenyl derivatives. The synthesis and chara cterization of two further similar imido-complexes but in which the ferroce nyl-phenyl group is part of a more extended unit is described (complexes 5 and 6). The synthesis of a rhenium oxo-complex, fac-oxotrichloro[1,1'-bis(d iphenylphosphine)ferrocene]rhenium(V) (3) has also been achieved and 3 has been further derivatized with two different ferrocenylamines to provide rhe nium complexes containing two ferrocenyl groups (4 and 7).