Acetylide Cluster Research Articles

Synthesis and skeletal isomerization of the phosphinidene acetylide cluster complexes [Ru4(CO)10(μ4-PPh)(CCPh){WL(CO)}] where L = C5Me5 or C5H5

Reactions of the phosphinidene cluster [Ru4(CO)13(µ3-PPh)] with tungsten acetylide complexes [WL(CO)3(CCPh)] (L = C5Me5 or C5H5) gave interconvertible isomers of formula [Ru4(CO)10(µ4-PPh)(CCPh){WL(CO)}]. The structures of the two C5Me5 derivatives were determined by X-ray diffraction, showing a novel WRu4P octahedral core arrangement, in which the acetylide ligand is co-ordinated to a WRu2 triangle with its C–C vector bridging the Ru–Ru edge. For one isomer the phosphinidene ligand is located at the position trans to the W atom, while in the second isomer it is at the cis position. Possible mechanisms for this rare example of skeletal isomerization are suggested.

Syntheses and Reactivity of Heterometallic Oxo−Acetylide Cluster Compounds. Skeletal Rearrangement and Conversion of Acetylide to Alkenyl, Alkylidene, and Allenyl Ligands on a WRe2 Framework

Oxidation of the mixed-metal cluster Cp*WRe2(CCR)(CO)9 (1, Cp* = C5Me5; R = Ph and C(Me)CH2) with dioxygen in solution at 100 °C affords the oxo clusters Cp*W(O)Re2(CCR)(CO)8, (2a, R = Ph; and 2b, R = C(Me)CH2. Treatment of 2 with CO at 110 °C provides the clusters Cp*W(O)Re2(CCR)(CO)9 (4), which revert back to 2 by removal of one CO upon thermolysis. Both compounds 2 and 4 contain an open triangular skeletal arrangement, a multisite bound acetylide ligand, and a terminal oxo ligand attached to the W atom. Complex 2a reacts with dihydrogen to form a mixture of three cluster complexes: the acetylide cluster Cp*WRe2(μ-O)(μ-H)2(CCPh)(CO)6 (5a), alkenyl cluster Cp*W(O)Re2(CHCHPh)(CO)8 (6a), and the alkylidene cluster Cp*W(O)Re2(μ-H)(CHCH2Ph)(CO)8 (7a), which are formally produced by addition of two H2 and elimination of two CO molecules, transferring one H2 to the acetylide ligand and incorporation of one H2 molecule to 6a, respectively. For the vinylacetylide compound 2b, it reacts with dihydrogen under sim...

Synthesis of the Tetranuclear Clusters RuM3H(C⋮CFc)(CO)12 (M = Ru, Os; Fc = Ferrocenyl), Containing a Fluxional μ4-Acetylide Ligand. Structure of a Mixed Crystal Containing Tetranuclear (Ru4H(C⋮CFc)(CO)12) and Trinuclear (Ru3H(C⋮CFc)(CO)9) Ruthenium Complexes

Reactions of acetylide clusters M3H(C⋮CFc)(CO)9 (1a, M = Ru; 1b, M = Os; Fc = ferrocenyl) with Ru3(CO)12 in refluxing hexane yield the tetranuclear clusters RuM3H(C⋮CFc)(CO)12 (2a,b) with a butterfly metal core. The μ4-acetylide ligand of these complexes undergoes migration, indicated by variable-temperature 1H and 13C NMR studies. Compounds 2a and 2b are relatively unstable in solution as well as in the solid state and decompose with formation of corresponding trinuclear acetylide precursors and Ru3(CO)12. The molecular structures of 1a and 2a were established by the X-ray diffraction study of a mixed crystal, which contains both clusters in a 1:1 ratio.

Synthesis and structure of the heteronuclear alkyne cluster RuOs3(μ4-HC2Me)(CO)12

The acetylide cluster Os3(μ-H)(μ3-CɢCMe)(CO)9 reacts with Ru3(CO)12 in refluxing hexane to give RuOs3(μ4-HC2Me)(CO)12 (2), a tetranuclear alkyne cluster with a butterfly metal core. Compound 2 was characterized by IR, NMR and single-crystal X-ray diffraction studies.

Competitive Acetylide C−C Bond Scission vs Formation of a Quadruply Bridging Carbonyl Ligand. X-ray Crystal Structures of the Two Pentanuclear Clusters Cp*3W3Ru2(μ4-C)(μ3-CPh)(CO)9 and Cp*3W3Ru2(μ3-CCBut)(CO)9

Reactions of Cp*WRu2(CCPh)(CO)8 (1a) with excess Cp*W(CO)3H, Cp* = C5Me5, affords a carbido−alkylidyne cluster Cp*3W3Ru2(μ4-C)(μ3-CPh)(CO)9 (5) alone with three byproducts, which are identified as hydride cluster Cp*WRu3(μ-H)3(CO)11 (2), vinylidene cluster Cp*2W2Ru2(CCHPh)(CO)9 (4), and a pentanuclear oxo−carbido cluster Cp*2W2(O)Ru3(μ5-C)(CO)11 (3). In contrast, the respective condensation using tert-butyl derivative Cp*WRu2(CCBut)(CO)8 (1b) gives an acetylide cluster Cp*3W3Ru2(μ3-CCBut)(CO)9 (6). The X-ray structural determinations of 5 and 6 reveals the existence of an edge-bridged tetrahedral core, in which the butterfly crater is occupied by a μ4-carbide in 5 or a quadruply bridging CO ligand in 6. A plausible mechanism leading to the formation of these two cluster compounds is also presented.

Reversible C−C Bond Cleavage and Interconversion of the Resulting Hydrocarbyl Ligands on Butterfly Frameworks Derived from Acetylide Complexes Cp*WOs3(μ4-CCR)(CO)11(R = Ph,nBu, CH2OMe, CH2OPh)

Combination of mononuclear complexes Cp*W(CO)3(CCR) (Cp* = C5Me5; R = Ph, nBu, CH2OMe, CH2OPh) with the triosmium cluster Os3(CO)10(NCMe)2 in toluene affords two isomeric acetylide cluster compounds a and b, which possess the formula Cp*WOs3(CCR)(CO)11 (R = Ph (1), nBu (2), CH2OMe (3), CH2OPh (4)). Isomers a and b undergo reversible interconversion by relocating the Cp*W(CO)2 fragment between the hinge and wingtip positions upon heating in solution. Their reactivities vs the substituents on the acetylide ligand are also investigated and compared. Thus, thermolysis of 1a furnishes the carbido−alkylidyne cluster Cp*WOs3(μ4-C)(μ-CPh)(CO)10 (5) through reversible scission of the C−C bond induced by elimination of CO. By contrast, heating of 2 or 3 gives an isomeric mixture of the carbido−vinylidene clusters Cp*WOs3(μ4-C)(μ-H)(μ-CCHR‘)(CO)9 (R‘ = nPr (6), OMe (7)) through a subsequent C−H activation. The CH2OPh isomers 4 readily eliminate two CO ligands to give two isomeric carbido−benzofuryl clusters Cp*WOs3(...

Reversible C-C Bond Scission and C-H Bond Activation in the Butterfly Acetylide Clusters Cp*WOs3(CO)11(CCR) (R = Ph, Bu, CH2OMe)

Reversible C-C Bond Scission and C-H Bond Activation in the Butterfly Acetylide Clusters Cp*WOs3(CO)11(CCR) (R = Ph, Bu, CH2OMe)

Reactions of Acetylide Clusters Cp*WRe2(CO)9(CCR) [R = Ph, C(Me):CH2, and Cyclohexenyl] with Thiophenol. Formation of WRe2 Thiolate Alkyne and Vinylalkylidyne Derivatives

Reactions of Acetylide Clusters Cp*WRe2(CO)9(CCR) [R = Ph, C(Me):CH2, and Cyclohexenyl] with Thiophenol. Formation of WRe2 Thiolate Alkyne and Vinylalkylidyne Derivatives

Heterometallic carbonyl cluster oxide. Formation, structure and reactivity of WRe2 oxo-acetylide cluster compounds

Cluster [WRe2(C5Me5)(O)(CO)8(CCPh)]1a possessing a terminal oxo ligand is prepared by treatment of the acetylide cluster [WRe2(C5Me5)(CO)9(CCPh)] with O2 or N2O; hydrogenation of 1a affords three isolable clusters, showing an example of oxo-ligand mediated sequential conversion of acetylide to alkenyl and alkylidene.

Rearrangement of acetylide and vinylidene ligands on the coordination spheres of cluster complexes. Reaction of the trinuclear acetylide cluster CpWOs2(CO)8(C.tplbond.CPh) with mononuclear metal hydride complexes LW(CO)3H (L = Cp, Cp*)

Reaction of CpWOs 2 (CO) 8 (C≡CPh) with 1.2 equiv of Me 3 NO in a mixture of dichloromethane-acetonitrile at room temperature followed by in situ reaction with hybride complexes LW(CO) 3 H, L=Cp and Cp*, in refluxing toluene produced the acetylide cluster complexes CpLW 2 Os 2 (CO) 9 (CCPh)(μ-H) (2a, L=Cp; 2b, L=Cp*) and vinylidene cluster complexes CpLW 2 Os 2 (CO) 9 (CCHPh) (3a, L=Cp; 3b, L=Cp*). Heating of the acetylide or vinylidene complex in refluxing toluene induced a reversible rearrangement, giving a mixture of both isomeric complexes. The structures of complexes 2b and 3b have been determined by single-crystal X-ray diffraction

Reaction of polynuclear acetylide clusters. Mixed-metal complexes derived from reactions of CpWOs3(CO)11(C.tplbond.CR) (R = Ph, nBu) with disubstituted alkynes

Reaction of CpW(CO) 3 (C≡CR) with Os 3 (CO) 10 (CH 3 CN) 2 in refluxing toluene produces tetranuclear mixed-metal acetylide complexes, CpWOs 3 (CO) 11 (C≡CR) (R=Ph (1a), n Bu (1b)). Reaction of 1a with excess ditolylacetylene in refluxing toluene effects the scission of acetylide ligand to give CpWOs 3 (CO) 8 (μ 3 -CPh)[μ 4 -η 5 -C(C 2 Tol 2 ) 2 ]. In contrast, treatment of complexes 1a and 1b with alkynes containing electron-withdrawing groups produces the tetranuclear alkyne-acetylide coupling products CpWOs 3 (CO) 10 [CR'CR'CCR] (R=Ph, R'=CO 2 Me, CO 2 Et); R= n Bu, R'=CO 2 Et) and CpWOs 3 (CO) 9 [CCRCR'CR'] (R=Ph, R'=CO 2 Me, CO 2 Et); R= n Bu, R'=CO 2 Et). The structures of complexes have been determined by single-crystal X-ray diffraction studies

ChemInform Abstract: Chemistry of Carbonyl‐Derived Ligands. Nucleophilic Attack on Anionic Acetylide Clusters.

AbstractThe triiron nonacarbonyl acetylide clusters (I) and (IV), which are derived from the iron ketenylidene (PPN)2(Fe3(CO)9CCO), add a single phosphine (II).

Nucleophilic attack on cluster-bound acetylide ligands derived from the iron ketenylidene, [Fe3(CO)9(CCO)]2?

Reaction of the iron ketenylidene (PPN)2[Fe3(CO)9CCO] [PPN =bis (triphenylphosphine)nitrogen(+1)] with trifluoroacetic anhydride forms a highly electrophilic acetylide cluster (PPN)[Fe3(CO)9CCOC(O)CF3] (lc), analogous to the known compounds (PPN)[Fe3(CO)9CCOR] [R=Et, (Ia); Ac, (Ib)] prepared from the reaction of ethyl triflate and acetyl chloride on the ketenylidene. Reaction of phosphines and (Ib, c) yield phosphonium acetylides [Fe3(CO)9CCPR3] [(II),R=Ph], with loss of (PPN)[CH3CO2] or (PPN)[CF3CO2]. Additionally, (Ic) and triphenylarsine react to give an analogous arsonium acetylide [Fe3(CO)9CCAsPh3] (III). No reaction occurs when an excess of arsine is added to (Ib). The reaction of (Ib, c) with anionic nucleophiles is reported, including reaction of Na[CpFe(CO)2] and (Ib) to afford an unusual metallated acetylide cluster (PPN) [Fe3(CO)9CCFe(CO)2Cp] (IV). Clusters (II), (III), and (IV) are spectroscopically characterized and a single crystal x-ray structure determination of (IV) is reported. (PPN)[Fe3(CO)9CCFe(CO)2Cp] (IV) crystallizes in the monoclinic space group P21/n;a=17.793(2) A;b=16.108(3) A;c=18.157(3) A;β=107.62(1)0;V=4959(3) A3;Z=4. Refinement of 469 variables on 5981 observed [I>3σ(I)] reflections converged toR=3.5% andRw=4.7%.

Chemistry of carbonyl-derived ligands. Nucleophilic attack on anionic acetylide clusters

The broad range of reactions of anionic ketenylidene clusters is reviewed. We then describe some chemistry of the triiron nonacarbonyl acetylide clusters (PPN)[Fe 3(CO) 9CCOR] (Ia,Ib), (a: R = CH 2CH 3; b: R = C(O)CH 3; PPN = bis(triphenylphosphine)iminium (1 +), (Ph 3P) 2N +), which are derived from the iron ketenylidene (PPN) 2[Fe 3(CO) 9CCO]. The ethoxyacetylide cluster Ia adds a single phosphine to form a phosphonium alkyne (PPN)[Fe 3(CO) 9PMePh 2CCOEt] (II). In contrast, Ib reacts with loss of acetate anion to form an unusual phosphonium acetylide cluster [Fe 3(CO) 9CCPMePh 2] (III), which is also formed cleanly by protonation of II with one equivalent of triflic acid, HSO 3CF 3. Implications of the formation of these products on bonding and mechanism are considered. Clusters II and III are spectroscopically characterized, and a single crystal X-ray structure determination of II and III are reported. (PPN)[Fe 3(CO) 9PMePh 2CCOEt] (II) crystallizes in the triclinic space group P 1 ; a 9.910(1); b 16.920(2); c 17.372(2) Å; α 74.83(1)°; β 84.65(1)°; γ 86.07(1)°; V 2796(1) Å 3; Z = 2. [Fe 3(CO) 9CCPMePh 2] (III) crystallizes with an orthorhombic lattice; space group Pbca; a 7.898(1); b 19.885(2); c 31.906(5) Å; V 5011(2) Å 3; Z = 8.

Synthesis of cluster complexes containing Au2(PPh3)2moieties: isolobal models of the interaction of H2with metal clusters. X-Ray structure of Au2Fe2Ir(µ4-C2Ph)(CO)7(PPh3)3

Reactions of several metal cluster complexes with [O{Au(PPh3)}3][BF4] in the presence of [ppn]+ salts [ppn =(Ph3P)2N] have given derivatives containing two Au(PPh3) moieties in which an Au–Au bond may or may not be present; in the title complex, an unusual Au–C interaction is present, which may model an intermediate stage in the addition of H2[isolobal with Au2(PPh3)2] to the parent Fe2Ir acetylide cluster, which reaction affords the hydrido-vinylidene complex Fe2Ir(µ-H)(µ3-CCHPh)(CO)8(PPh3).

Electron rich acetylide clusters; molecular and electronic structure and reactions of Os3(CO)7(µ2-η2-CCR)2(µ-PPh2)2(R = Ph, Pri); 50-electron species with expanded metal frameworks

The reactivity of the 50-electron acetylide clusters Os3(CO)7(µ2-η2-CCR)2(µ-PPh2)2[(1a) R = Ph; (1b) R = Pri] which have unusual expanded Os3 frameworks, is dominated by nucleophilic addition at the metals: the molecular structures of Os3(CO)7(µ2-η2-CCPri)2(µ-PPh2)2 and the ethylamine adduct of (1a), Os3(CO)6(µ2-η2-CCPh)(η1-CCPh)(µ-PPh2)2(EtNH2)2(2a) have been determined by X-ray diffraction and their electronic structures probed by EHMO calculations.

Rotation of the acetylide ligand on the triangular face of tungsten-diruthenium clusters. Crystal structure and solution dynamics of LWM 2(CO) 8(CCPh), L = C 5H 5, C 5Me 5 and M = Os, Ru

Reaction of CpW(CO) 3CCPh with OS 3(CO) 10(CH 3CN) 2 or Ru 3(CO) 12 in refluxing toluene gives trinuclear mixed-metal acetylide clusters, CpWOs 2(CO) 8(CPh) ( 1) and CpWRu 2(CO) 8(CCPh) ( 3); the acetylide ligands of these two complexes are related to each other by a 120° rotation as indicated by X-ray diffraction studies. In solution, the variable temperature 1H and 13C NMR spectra suggest that the acetylide ligand of 3 undergoes a 360° rotation on the face of the WRu 2 triangle.

ChemInform Abstract: Cluster‐Assisted Formation and Cleavage of C‐H and C‐C Bonds. (Fe3(CO)9(CCO))2‐ and Its Acetylide and Alkyne Derivatives.

AbstractThe ketenylidene cluster (I) is acetylated or ethylated at the ketenylidene O atom to generate the anionic acetylide clusters (IIIa) and (IIIb).

Conversion of the ketenylidene cluster [Fe3(CO)9(C:C:O)]2- into the acetylide cluster [Fe3(CO)9(C.tplbond.COAc)]-, and reactivity of the acetylide system

L'acylation de [Fe 3 (CO) 9 (CCO)] 2− a lieu sur l'atome d'oxygene de cetenylidene pour generer [Fe 3 (CO) 9 (CCOC(O)CH 3 )] etudie par RX