Reaction of alkyne cluster Os3(μ-CO)(CO)9(μ3-η1:η1:η2-Me3SiC2Me) with HC≡CCOOMe. Molecular and crystal structures of Os3(CO)9{μ3-η1:η1:η2:η2-C(SiMe3)C(Me)C(COOMe)CH× and Os3(CO)8{μ3-η1:η1:η4:η1-C(SiMe3)C(Me)C(H)C(COOMe)CH× complexes

Reaction of the cluster Os₃(μ-CO)(CO)₉(μ₃-η¹:η¹:η²-Me₃SiC₂Me) with HC≡CCOOMe in benzene at 70 °C results in Os₃(CO)₉{μ₃-η¹:η¹:η²:η²-C(SiMe₃)C(Me)C(COOMe)CH× (5), Os₃(CO)₉{μ₃-η¹:η¹:η²:η²-C(SiMe₃)C(Me)C(H)C(COOMe)CH× (6), Os₃(CO)₉{μ-η¹:η¹:η⁴-C(SiMe₃)C(Me)C(H)C(COOMe)CH× (7), and Os₃(CO)_δ{μ₃-η¹:η¹:η⁴:η¹-C(SiMe₃)C(Me)C(H)C(COOMe)× complexes (8), containing an osmacyclopentadiene moiety. Complexes5–8 were characterized by¹H NMR and IR spectroscopy. The structure of clusters5 and8 was confirmed by X-ray analysis. Complex7 is formed from cluster5 as a result of a new intramolecular rearrangement and complex8 is obtained by decarbonylation of compound6. Complex8 adds PPh₃ to give Os₃(CO)_δ(PPh₃){μ-η¹:η¹:η⁴-C(SiMe₃)C(Me)C(H)C(COOMe)×.     

Reaction of Os3(μ-Cl)2(CO)10 with Ph2PCH2PPh2. The formation of a novel 12-membered macrocycle containing C, P, Cl, and Os atoms in the ring

The reaction of Os₃(μ-Cl)₂(CO)₁₀ (1) with Ph₂PCH₂PPh₂ (dppm) in a toluene solution at 65°C results in novel osmium complexes [Os₃(μ-Cl)₂(CO)₉]₂(dppm) (2) and [Os₃(μ-Cl)₂(CO)₈]₂(dppm)₂ (3). Compounds 2 and 3 were characterized by¹H and³¹P NMR, and IR spectroscopy and their structures were established by X-ray analysis. In both compounds, dppm is a bridging ligand between the two cluster units. Molecule3 can be considered as an unusual 12-membered macrocycle containing C, P, Cl, and Os atoms in the ring. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1844–1851, September, 1998.     

Redox behavior of trinuclear M3(μ-H)(μ3-μ1:μ2:μ2-C2Fe)(Co)9 and tetranuclear RuM3 3(μ-H)(μ4-μ1:μ1:μ1:μ2-C2Fe)(Co)12 (M=Ru or Os; and Fc=ferrocenyl) clusters. Electronic interaction between the ferrocenylacetylide ligand and the metal core of the cluster

The redox properties of the clusters Ru₃(CO)₁₂(1), Ru₃(μ-H)(μ₃-μ¹:μ²:μ²-C₂Fe)(CO)₉ (2), OS₃(μ-H)(μ₃-μ¹:μ²:μ²-C₂Fe)(CO)₉ (3), Ru₄(μ-H)(μ₄-μ¹:μ¹:μ¹:μ²-C₂Fe)(CO)₁₂ (4), and RuOS₃(μ-H)(μ₄-μ¹:μ¹:μ¹:μ²-C₂Fe)(CO)₁₂ (5) in THF have been studied by cyclic voltammetry in the temperature range from ?60 to +20°C. It was demonstrated that reversible one-electron oxidation of the ferrocenyl fragment in clusters 2–5 occurs at more positive potentials (δE ⁰=0.15–0.26 V) than that of free ferrocene. This is indicative of the electron-withdrawing character of the cluster core with respect to the ferrocenylacetylide ligand. The electron-withdrawing effect of the metal core is more pronounced in tetranuclear clusters4 and 5 than in trinuclear clusters2 and3. Unlike complexes1–3, which undergo irreversible reduction, complexes4 and5 undergo reversible one-electron reduction to form the corresponding radical anions4 ^? and5 ^?.     

New ruthenocene-based ruthenium pincer complex bearing the C<Subscript>5</Subscript>Me<Subscript>4</Subscript>CF<Subscript>3</Subscript> ligand

The first (trifluoromethyl)tetramethylruthenocene-based ruthenium pincer complex RuCl(CO)[{2,5-(Bu ₂ ^t PCH₂)₂C₅H₂}Ru(C₅Me₄CF₃)] was synthesized by cyclometallation of the bisphosphine ligand {1,3-(Bu ₂ ^t PCH₂)₂C₅H₂}Ru(C₅Me₄CF₃) with RuCl₂(DMSO)₄ in 2-methoxyethanol in the presence of NEt₃. The new complex was fully characterized by ¹H, ¹⁹F, ³¹P{¹H}, ¹³C{¹H} NMR and IR spectroscopy.     

Electronic effect of ferrocenyl,ruthenocenyl, and osmocenyl group as substituents

Conclusions According to the¹⁹F NMR spectra of the m- and p-fluorophenyl derivatives of ferrocene, ruthenocene, and osmocene, the inductive component successively increases and the resonance component of the electron-donor effect of the metallocenyl groups successively decreases with increase in the order number of the metal.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1170–1172, May, 1981.     

Synthesis of the gold-dirhenium ferrocenylacetylide cluster. The crystal structure of Re2(μ-C≡CFc){Au(PPh3)}(CO)8

The thermal reaction of Re₂(CO)₈(NCMe)₂ with Au(CCFc)PPh₃ afforded the cluster Re₂(-CCFc){Au(PPh₃)}(CO)₈, which was characterized by X-ray diffraction analysis.     

Functionalization of one or two methyl groups in the [Cp*<Subscript>2</Subscript>RuBr]<Superscript>+</Superscript>Br<Superscript>−</Superscript> complex in the reaction with bromine

The reaction of [Cp*₂RuBr]⁺Br⁻ with bromine in CH₂Cl₂ (CD₂Cl₂) in an inert atmosphere at room temperature produces the complexes [Cp*Ru(Br)C₅Me₄CH₂Br]⁺Br₃ ⁻ (syn conformer), [Cp*Ru(Br)C₅Me₃(CH₂Br)₂]⁺ (syn and anti conformers), and [Ru(Br)(C₅Me₄CH₂Br)₂]⁺ (syn conformer). All complexes were characterized by ¹H and ¹³C NMR spectroscopy; the former complex, by elemental analysis. These complexes were also prepared by the reaction of [Cp*RuC₅Me₄CH₂]⁺BF₄ ⁻ with bromine in CH₂Cl₂. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2712–2718, December, 2005.     

Alkyne-vinylidene coupling in the reactions of the alkyne complex Os3(μ-CO)(CO)9(μ3-Me3C2Me) with Me3SiC≡CR (R=Me, Bun). The structure and stereodynamic behavior of clusters Os3(CO)9{μ3-C(SiMe3)=C(Me)C=C(SiMe3)=C(Me)C=C(SiMe3)R} containing an osmacyclobutene moietycontaining an osmacyclobutene moiety

Reactions of the alkyne cluster Os₃(μ-CO)(CO)₉(μ₃-Me₃C₂Me) with alkynes Me₃SiC≡CR (R=Me, Buⁿ) in refluxing hexane result in the formation of clusters Os₃(CO)₉{μ₃-C(SiMe₃)=C(Me)C=C(SiMe₃)=C(Me)C=C(SiMe₃)R} (2a: R=Me;3a: R=Buⁿ). The dienediyl ligand in these complexes is formed by alkyne-vinylidene coupling, with vinylidene generated in the course of reaction from the alkyne molecule by the acetylene-vinylidene rearrangement involving a 1,2-shift of the Me₃Si group. The structure of cluster3a was determined by X-ray structural analysis. The dienediyl ligand is coordinated to three metal atoms of the cluster framework by two π-ethylene bonds with two osmium atoms and two σ-bonds with the third osmium atom with the formation of the osmacyclobutene moiety. The¹H and¹³C NMR study of¹³CO-enriched samples of clusters2a and3a revealed the stereochemical nonrigidity of these molecules due to the exchange of the hydrocarbon and carbonyl ligands.