Trinuclear ReFePt clusters with a µ3-phenylvinylidene ligand: synthetic approaches, rearrangement of vinylidene, and redox-induced transformations.

A series of trinuclear µ3-vinylidene ReFePt clusters were synthesized by the application of two approaches: (i) reactions of the binuclear RePt µ-vinylidene complexes with Fe2(CO)9; (ii) ligand substitution or exchange reactions at the Pt atom in the synthesized ReFePt clusters. The molecular structures of CpReFePt(µ3-CCHPh)(CO)5[P(OEt)3]L [L = CO; P(OEt)3] were determined by an X-ray diffraction study. The obtained compounds were studied by IR and 1H, 13C and 31P NMR spectroscopy. The spectroscopic study revealed that the clusters CpReFePt(µ3-CCHPh)(CO)5[P(OEt)3]L [L = CO; P(OEt)3] and CpReFePt(µ3-CCHPh)(CO)6[P(OPri)3] undergo isomerization upon dissolution, resulting in three isomers with different positions of the µ3-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(µ3-CCHPh)(CO)6[P(OPri)3] and CpReFePt(µ3-CCHPh)(CO)5[P(OEt)3]2 with ferrocenium tetrafluoroborate were characterized by EPR spectroscopy.

Manganese-gold-manganese complex with vinylidene and acetylide units.

A series of reactions of Cp(CO)2Mn[double bond, length as m-dash]C[double bond, length as m-dash]CHPh with different gold(i) complexes of [Au-C[triple bond, length as m-dash]C-R]n (R = 4-C5H4N, C6H5) and (tht)AuCl yielded one novel trinuclear MnAuMn cluster. The structure of this cluster can be rationalized as being formed of a vinylidene Mn-Au binuclear and Mn-acetylide fragments, and the binding between those is achieved mainly through the sharing of the electron pair of the single Mn-C σ-bond of an acetylide unit with the gold center.

Crystal structure of µ-carbonyl-1:2κ2C:C-carbonyl-1κC-(1η5-cyclo-penta-dien-yl)iodido-2κI-[µ-2-(pyridin-2-yl)ethene-1,1-diyl-1κC1:2κ2N,C1]ironpalladium(Fe-Pd) benzene monosolvate.

The reaction of Cp(CO)2FeI with 2-ethynyl-pyridine under Sonogashira conditions [5% PdCl2(PPh3)2, 10% CuI, THF-NEt3 (2:1)] afforded the title binuclear µ-pyridyl-vinyl-idene FePd complex (FePd1) as a benzene solvate, [FePd(C5H5)(C7H5N)I(CO)2]·C6H6, in a very low yield rather than the expected iron o-pyridyl-ethynyl complex Cp(CO)2Fe-C≡C-(2-C5H4N). The Fe and Pd atoms in FePd1 are bridged by carbonyl and pyridyl-vinyl-idene ligands, the pyridyl N atom being bonded to the palladium atom. The use of equimolar amounts of PdCl2 increases the yield of FePd1 to 12%. The reaction pathway leading to FePd1 is proposed.