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The first example of a complex containing a C₁₉ chain, {Co₃(μ-dppm)(CO)₇}{μ₃-C(C≡C)₉}{W(CO)₃Cp}, has been prepared in 22% yield from the Pd(0) / Cu(I)-catalysed reaction between I(C≡C)₃I, W{C≡CC≡CAu(PPh₃)}(CO)₃Cp and Co₃{μ₃-C(C≡C)₄Au(PPh₃)}(μ-dppm)(CO)₇. Other products also formed include {Co₃(μ-dppm)(CO)₇}{μ₃-C(C≡C)₆}{W(CO)₃Cp} (32%), {Co₃(μ-dppm)(CO)₇}₂{μ₃:μ₃-C(C≡C)xC} [x = 8 (6%) and 11 (5%)], containing respectively C₁₃, C₁₈ and C₂₄ chains, and {W(CO)₃Cp}₂{μ-(C≡C)x} (x = 4, 7) (traces). A second example of a 19-atom chain is found in Hg{(C≡C)₄C[Co₃(μ-dppm)(CO)₇]}₂, obtained in 24% yield from the reaction between Hg(OAc)₂ and Co₃{μ₃-C(C≡C)₄SiMe₃}(μ-dppm)(CO)₇ in the presence of NaOMe.
The syntheses of over sixty known and new derivatives of Ru₃(CO)₁₂ and H₄Ru₄(CO)₁₂ by substitution reactions initiated by sodium diphenylketyl are described. The range of ligands studied includes isocyanides, tertiary phosphines and phosphites, tertiary arsines and SbPh₃. The reactions are characterised by high degrees of specificity and conversion: under mild conditions up to four ligands can be introduced. Comparisons with the corresponding thermally induced reactions are made in several cases. The reactions provide routes to mixed ligand derivatives of the cluster carbonyls, although account of relative Lewis base strengths of the ligands may have to be taken. Possible mechanisms of these reactions are discussed briefly, as are the IR ν (CO) spectra of the Ru₃ (CO)12-nLn complexes.
Several complexes containing Co₃ carbonyl clusters end-capping carbon chains of various lengths are described. Pd(0)/Cu(I)-catalysed reactions between {Co₃{μ₃-C(Ctriple bond; length of mdashC)₂Au(PPh₃)}(μ-dppm)(CO)₇ and I(Ctriple bond; length of mdashC)₂SiMe₃ or FcCtriple bond; length of mdashCI gave {Co₃{μ₃-C(Ctriple bond; length of mdashC)xR}(μ-dppm)(CO)₇ [x = 4, R = SiMe₃3; x = 3, R = Fc 8]; treatment of 3 with NaOMe and AuCl(PPh₃) gave 4 [x = 4, R = Au(PPh3)]. Related preparations of Co₃{μ₃-C(Ctriple bond; length of mdashC)₂[Ru(PP)Cp′]}(μ-dppm)n(CO)9−2n [PP = (PPh₃)₂, Cp’ = Cp, n = 1, 5; PP = dppe, Cp′ = Cp∗, n = 1, 6; 0, 7] are also described. Syntheses of bis-cluster complexes {Co₃(μ-dppm)(CO)₇}₂(μ-Cx) (x = 14, 12; 16, 9; 18, 11; 26, 10) – the latter being the longest cluster-capped Cx chains so far described – and the mercury-br...
Reactions between [M2(dppm)2(NCMe)2]X2 [M = Ag, X = ClO₄; M = Cu, X = BF₄] and Ru(C CC CM)(dppe)Cp* [M = Ag, Cu; generated in situ from Ru(C CC CH)(dppe)Cp* and AgNO₃ or CuCl(PPh₃), respectively] afford the cationic mixed-metal cluster diynyl complexes [M₆{μ₃-C CC C[Ru(dppe)Cp*]}₄(μ-dppm)₂]X₂, of which the structures were determined by single-crystal XRD studies. Electrochemical studies indicate that there is no interaction between the ruthenium centres. Reactions between [M₂(μ-dppm)₂(NCMe)₂](BF₄)₂ and Ru(C CC CM′)(dppe)Cp* (M,M′ = Cu, Ag) afforded a mixture of Ag6−nCun clusters, as shown by ES-MS and crystallographic studies. Preliminary studies suggest that extensive disproportionation occurs in solution.
Treatment of Co₃(μ₃-CC≡CR)(μ-dppm)(CO)₇ with O₂ (air) in the presence of [FcH]PF₆ afforded Co₃{μ₃-CC(O)R}(μ-dppm)(CO)₇ by the formal conversion –C≡C– + O–O → >C–O + C≡O. In this way, complexes with R = Ph, Fc, and W(CO)₃Cp, bis-clusters {Co₃(μ-dppm)(CO)₇}₂{μ₃:μ₃-[≡C(O)(C≡C)C≡]}, {Co₃(μ-dppm)(CO)₇}₂{μ₃:μ₃-[≡C(O)(C≡C)xC(O)C≡]} (x = 1, 2), and {Co₃(μ-dppm)(CO)₇}₂{μ₃:μ₃-[≡CC(O)C≡CC₆H4C≡CC(O)C≡]}, and heterometallic bis-clusters {Co₃(μ-dppm)(CO)₇}{μ₃:μ₃-[≡CC(O)C≡CC≡]}{M₃(μ-H)₃(CO)₉} (M = Ru, Os) have been prepared. Single-crystal XRD structure determinations of several products are reported together with that of precursor {Co₃(μ-dppm)(CO)₇}₂{μ₃:μ₃-[≡C(C≡C)₂C₆H₄(C≡C)₂C≡]}.
The reaction between Ru(C≡CC≡CAg)(dppe)Cp* and tcne affords a novel percyanovinylidene complex by an unusual decyano-dimerization reaction of the cyanocarbon with the diynyl fragment. This complex is also obtained from tcne and Ru{C≡CC≡C[Au(PPh₃)]}(dppe)Cp*, together with Ru{C≡CC[═C(CN)₂]C[Au(PPh₃)]═C(CN)₂}(dppe)Cp*, formed by the anticipated [2 + 2] cycloaddition and subsequent ring-opening reactions.
The preparation, characterisation and single-crystal XRD molecular structure determinations of four complexes containing –CC–MLn end-groups, namely Ru{C≡CFc′(I)}(dppe)Cp (1), the vinylidene [Os(=C=CH₂)(PPh₃)₂Cp]PF₆ (2), trans-Pt(C≡CC₆H₄-4-C≡CPh){C≡CC₆H₄-4-C₂Ph[Co₂(μ-dppm)(CO)₄]}(PPh₃)₂ (3), and C₆H₄{μ₃-C₂[AuRu₃(CO)₉(PPh₃)]}₂-1,4 (4) are reported. In these compounds a range of –CC– environments is found, extending from the σ-bonded alkynyl group in 1 to examples where the C₂ unit interacts with either a proton (in vinylidene 2), by bridging a dicobalt carbonyl moiety (in 3) or the AuRu₃ cluster in 4. Changes in geometry are rationalised by considering the various bonding modes.
The complex Ru{C≡CC(CN)═C(CN)₂}(dppe)Cp* (1), containing the new tricyanovinylethynyl (3,4,4-tricyanobut-3-en-1-ynyl) ligand, undergoes ready substitution of the 3-cyano group by nucleophiles (Nu) such as H, Me, Pri, Bu, But, mesityl, OMe, OBut, OCH2CH═CH₂, NHEt, NEt₂, and PPh₂ to give Ru{C≡CC(Nu)═C(CN)₂}(dppe)Cp*. The X-ray diffraction structures of several of the resulting complexes are reported and, for the mesityl and PPh₂ products, show that isomerization to the 3,5-dimethylbenzyl and oxidation to the phosphine oxide have respectively occurred.
Several new gold-containing cluster complexes have been prepared from the reactions of gold alkynyl complexes, L n M-C x -Au(PPh₃), (x = 3, 4, 6) with Ru₃(CO)₁₀(NCMe)₂. The bis-cluster complex 1,4-{AuRu₃(CO)₉(PPh₃)(μ₃-C₂)}₂C₆H₄ was obtained from Ru₃(CO)₁₀(NCMe)₂ and 1,4-{(Ph₃P)Au(C≡C)}₂C₆H₄. The complexes Ru₃(μ-H){μ₃-C₂C≡C[Ru(PP)Cp′]}(CO)₉ [PP = (PPh₃)₂, Cp′ = Cp; PP = dppe, Cp′ = Cp*] were also obtained as minor by-products and synthesised independently from Ru(C≡CC≡CH)(PP)Cp′. A reaction between Co₃{μ₃-CC≡CC≡CAu(PPh₃)}(μ-dppm)(CO)₇ and Ru₃(CO)₁₂ afforded {(Ph₃P)(OC)₉AuRu₃}C≡CC≡CC{Co₃(μ-dppm)(CO)₇} 7. Related complexes AuRu₃{μ₃-C₂C≡[M(CO)₂Tp]}(CO)₉(PPh₃) (M = Mo 8, W 9) were obtained from {Tp(OC)₂M}≡CC≡C{Au(PPh₃)}, while the mixed metal cluster complexes MoM₂(C₂Me)(CO)₈Tp (M = Ru 13, Fe 14) were obtained from M(≡CC≡CSiMe₃)(CO)₂Tp (M =...
The ambient temperature reaction of the N-heterocyclic carbenes (NHCs) 1,3-dimesitylimidazol-2-ylidene (IMes) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IDipp) with the triruthenium cluster [Ru3(CO)12], in a 3 : 1 stoichiometric ratio, results in homolytic cleavage of the cluster to quantitatively afford the complexes [Ru(CO)4(NHC)] (1; NHC = IMes, 2; NHC = IDipp). Reaction of the 2-thione or hydrochloride precursors to IMes, i.e. S[double bond, length as m-dash]IMes and IMes·HCl, with the same triruthenium cluster affords the complexes [Ru4(µ4-S)2(CO)9(IMes)2] (3) and [Ru4(µ4-S)(CO)10(IMes)2] (4) (3 : 1 and 2 : 1 reaction), and [{Ru(µ-Cl)(CO)2(IMes)}2] (7) (3 : 1 reaction) respectively. By contrast, the complex [Ru3(µ3-S)2(CO)7(IMeMe)2] (6), where IMeMe is 1,3,4,5-tetramethylimidazol-2-ylidene, is the sole product of the 2 ...
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