A. M. Sheloumov

Synthesis of ferrocenylacetylide derivatives of gold-ruthenium and gold-osmium clusters. Crystal structures of M3(AuPPh3)(C≡CFc)(CO)9 (M=Ru or Os; Fc is ferrocenyl)

The synthesis and crystal structures of the clusters M3(AuPPh3)(C≡CFc)(CO)9 (M=Ru,3a; or M=Os,3b) are described. Compound3a was synthesized by deprotonation of Ru3H(C≡CFc)(CO)9 under the action of KOH/EtOH followed by treatment of the anionic complex [Ru3(C≡CFc)(CO)9]− with chloro(triphenylphosphine)gold. Compound3b was prepared by the reaction of Os3(CO)10(NCMe)2 with FcC≡CAuPPh3, which was synthesized by the reaction of FcC≡CNa with ClAuPPh3. The pentanuclear cluster Ru4(AuPPh3)(C≡CFc)(CO)12 (4a), which was prepared by the reaction of3a with Ru3(CO)12, was characterized by spectral methods.

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 (δE0=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−.

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(C≡CFc)PPh3 afforded the cluster Re2(μ-C≡CFc){Au(PPh3)}(CO)8, which was characterized by X-ray diffraction analysis.

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.

Reduction of (1,3-diformylindenyl)cyclopentadienylruthenium derivatives

The reduction of the (1,3-diformylindenyl)cyclopentadienylruthenium derivatives {η5-1,3-(CHO)2C9H5}RuCp (Cp = C5H5), {η5-1,3-(CHO)2C9H5}RuCp* (Cp* = C5Me5), and {η5-1,3-(CHO)2C9H5}RuCpF (CpF = C5Me4CF3) with NaBH4 or LiAlH4 under mild conditions affords the [1,3-bis(hydroxymethyl)indenyl]cyclopentadienylruthenium complexes {η5-1,3-(CH2OH)2C9H5}RuCp, {η5-1,3-(CH2OH)2C9H5}RuCp*, and {η5-1,3-(CH2OH)2C9H5}-RuCpF, respectively, in good yields.

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)×.