Trinuclear ReFePt clusters with a μ 3 -phenylvinylidene ligand: synthetic approaches, rearrangement of vinylidene, and redox-induced transformations

A series of trinuclear μ -vinylidene ReFePt clusters were synthesized by the application of two approaches: (i) reactions of the binuclear RePt μ-vinylidene complexes with Fe (CO) ; (ii) ligand substitution or exchange reactions at the Pt atom in the synthesized ReFePt clusters. The molecular structures of CpReFePt(μ -CCHPh)(CO) [P(OEt) ]L [L = CO; P(OEt) ] were determined by an X-ray diffraction study. The obtained compounds were studied by IR and H, C and P NMR spectroscopy. The spectroscopic study revealed that the clusters CpReFePt(μ -CCHPh)(CO) [P(OEt) ]L [L = CO; P(OEt) ] and CpReFePt(μ -CCHPh)(CO) [P(OPr ) ] undergo isomerization upon dissolution, resulting in three isomers with different positions of the μ -vinylidene ligand over the ReFePt core. The redox properties of the clusters were studied by electrochemical methods. The relatively stable cation-radicals obtained by chemical oxidation of CpReFePt(μ -CCHPh)(CO) [P(OPr ) ] and CpReFePt(μ -CCHPh)(CO) [P(OEt) ] with ferrocenium tetrafluoroborate were characterized by EPR spectroscopy.