Synthesis of Palladium Clusters with the P--N--P Assembling Ligands (Ph2P)2CH2 (dppm) and (Ph2P)2NH (dppa). Crystal Structure of [Pd4(μ-Cl)2(μ-dppm)2(μ-dppa)2](PF6)2

Tetrapalladium clusters containing dppa or dppa and dppm bridging ligands were prepared by condensation of dinuclear units. Reaction of [Pd₂Cl₂(-dppa)₂] with [Cu(PPh₃)]PF₆ (generated in situ in THF) yielded [Pd₄(-Cl)₂(-dppa)₄] (PF₆)₂ (4) in a virtually quantitative yield but [Pd₄(-Cl)₂(-dppm)₂(-dppa)₂] (PF₆)₂ (6) was best prepared in CH₂Cl₂ from [Pd₂Cl₂(-dppm)₂] and [Pd₂(MeCN)₂(-dppa)₂](PF₆)₂ (2). The structure of 6·2(CH₃)₂CO·2H₂O was determined by X-ray diffraction. It consists of a planar, centrosymmetric 10-membered ring structure. The four bridging diphosphine ligands are of two types: two dppa ligands support the Pd Pd bonds [2.6055(4) Å], whereas the two dppm ligands bridge between two palladium atoms separated by 3.722(4) Å, which are also bridged by a chloride ligand.     

Synthesis and X-ray structures of some mono- and binuclear ruthenium complexes with bisphosphine ligands

Summary The dinuclear complexes {RuCp*(-Cl)}₂(-dppm) (1) and {RuCp*(-Cl)}₂ (-dppe) (3) are obtained by reacting [RuCp*(³-Cl)]₄ withdppm, anddppe, respectively.1 is readily oxidized with AgCF₃SO₃, instead of chloride abstraction, to afford the dinuclear complex [{RuCp*(-Cl)}₂(-dppm)](SO₃CF₃)₂ (2) with two metal centers connected by a single Ru-Ru bond. Under the same conditions,3 decomposes to several intractable materials. Similarly to1, RuCp* (dmpe)Cl reacts with AgCF₃SO₃ to afford the Ru(III) complex [RuCp*(dmpe)Cl](SO₃CF₃) (4) without no halide abstraction. The crystal structures of2,3, and4 are presented.

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Synthese und Röntgenstrukturanalyse einiger ein- und zweikerniger Rutheniumkomplexe mit Bisphosphinliganden

Zusammenfassung Die Komplexe {RuCp*(-Cl)}₂(-dppm) (1) und {RuCp*(-Cl₂(-dppe) (3) wurden durch Umsetzung von [RuCp*(³-Cl)]₄ mitdppm bzw.dppe dargestellt.1 wird durch AgCF₃SO₃ zum zweikernigen Komplex [{RuCp*(-Cl)}₂(-dppm)](SO₃CF₃)₂ (2) oxidiert, welcher eine Ru-Ru-Metallbindung aufweist. Unter den gleiche Reaktionsbedingungen zersetzt sich3 zu undefinierten Produkten. Analog zu1 reagiert RuCp* (dmpe)Cl mit AgCF₃SO₃ zum Ru(III)-Komplex [Ru(Cp*)(dmpe)Cl](SO₃CF₃) (4) wobei es zu keiner Chloridabspaltung kommt. Von2,3, und4 wurden die Kristallstrukturen bestimmt.

     

Addition of HCl to a Cluster-Bound Vinylidene Ligand: Preparation and Structure of Ru5(μ3-SMe)(μ3-CMe)(μ-Cl)(μ-SMe)(μ-PPh2)2(CO)9·PhMe

Addition of aqueous HCl to Ru₅( ₃-C=CH₂)(-SMe)₂(-PPh₂)₂(CO)₁₀ afforded the structurally characterized carbyne complex Ru₅( ₃-SMe)( ₃-CMe)(-Cl)(-SMe)(-PPh₂)₂(CO)₉, formed by addition of H to the vinylidene ligand; a Cl atom bridges an Ru–Ru bond.     

C-C bond formation at polynuclear metal centers

Studies on C-C bond formation between simple hydrocarbon species such as CH₂, C=CH₂, CH=CH₂, CH₂=CH₂, CH₂=C=CH₂ and CHCH at a diruthenium center suggest that the process is promoted when the dimetal center can readily compensate for the two electrons lost in the formation of the new C-C bond. Thus, whereas -CH₂ and ethene combine only under forcing conditions, the combination of -CH₂ with allene or ethyne, which have additional -electrons available for coordination, occurs readily at room temperature. Likewise, the availability of uncoordinated -electrons in -C=CH₂ allows vinylidene to link rapidly with ethene at room temperature. Alkyne complexes [Ru₂(CO)(-RCCR)(-C₅H₅)₂] (R=CF₃ or Ph) react only under vigorous conditions with additional alkyne to give [Ru₂(CO)(-C₄R₄) (-C₅H₅)₂], but give these same species at room temperature in the presence of acid, shown to be due to the intermediacy of highly reactive 30-electron -vinyl cations. Thermally, alkyne linking proceedsvia three-alkyne species [Ru₂(-C₆R₆)(-C₅H₅)₂] to a four-alkyne complex [Ru₂(-C₈R₈)(-C₅H₅)₂], containing an unprecedented C₈ ligand composed of a C₆ ring with a C₂ tail. Treatment of [Ru₂(CO)(-RCCR)(-C₅H₅)₂] with unsaturated metal fragments gives trimetal complexes such as [Ru₃(CO)₅(₃-CF₃CCCF₃) (-C₅H₅)₂]. The MeCN derivative of this species undergoes unusual linking processes on reaction with additional alkyne to giveinter alia [Ru₃(CO)₃(₃-CCF₃){₃-C₃(CF₃)₃}(-C₅H₅)₂], arising from alkyne cleavage, and [Ru₃(CO)₃{₃-C₄(CF₃)₂(CO₂Me)₂}(-C₅H₅)₂], a closo-pentagonal bipyramidal Ru₃C₄ cluster.     

The Synthesis and Reactivity of New μ 2- and μ 3-Aminophosphinidene Cobalt Complexes

The reaction of K[Co(CO)₄] and PCl₂(TMP) at –5°C leads to the unstable and reactive -phosphinidene complex [Co₂(CO)₆{-P(TMP)}] (1), while the same reaction carried out at 35°C gives the chlorophosphido and phosphinidene bridged cluster [Co₃(CO)₇{-P(Cl)TMP}{ ₃-P(TMP)}] (2) (TMP=2,2,6,6-tetramethylpiperidyl). Compound 1 reacts with dppm (dppm=bis(diphenyl- phosphino)methane) and [Co₂(CO)₈] to form the more stable substitution product [Co₂(CO)₄{-P(TMP)}(-dppm)] (3) and [Co₄(CO)₇(-CO)₃{ ₃-P(TMP)}] (4) respectively. The first example of a cationic ₃-phosphinidene cluster compound [Co₃(CO)₉{ ₃-P(TMP)}][AlCl₄] (5) is obtained from reaction of 3 with AlCl₃. The X-ray structures of clusters 2 and 5 are discussed.     

Reactions of the Ru3(CO)10(μ-Ph2PCH2PPh2) cluster with enynes RCH=CHC≡CR (R is phenyl or ferrocenyl). Formation of indenone derivatives of triruthenium clusters

The thermal reaction of Ru₃(CO)₁₀(-Ph₂PCH₂PPh₂) (1) with enyne PhCH=CHCCPh afforded the trinuclear ruthenium clusters Ru₃(CO)₆{₃-P(Ph)CH₂PPh₂}{₃-C(Ph)=CHCC(Ph)(1,2-C₆H₄)C(=0)} (2), Ru₃(-H)(CO)₅{₃-P(Ph)CH₂PPh₂}{₃-C(Ph)=CHCC(Ph)(1,2-C₆H₄)C(—0)} (3), and Ru₃(CO)₆(-CO){₃-P(Ph)CH₂PPh₂}{₃-C(C=CPh₂)CH=C(H)Ph} (4) and also two isomers of Ru₃(CO)₅(-CO)(-Ph₂PCH₂PPh₂){₃-C₄Ph₂(CH=CHPh)₂} (5a and 5b). Clusters 2, 3, and 4 were characterized by IR spectroscopy, ¹H and ³¹P NMR spectroscopy, and X-ray diffraction analysis. The reaction of complex 1 with enyne FcCH=CHCCFc gave rise to the Ru₃(CO)₆{₃-P(Ph)CH₂PPh₂}{₃-C(Fc)=CHCC(Fc)(1,2-C₆H₄)C(=0)} (6) and Ru₃(-H)(CO)₅{₃-P(Ph)CH₂PPh₂}{₃-C(Fc)=CHCC(Fc)(1,2-C₆H₄)C(—0)} (7) clusters. According to the spectral data, the latter compounds are isostructural to complexes 2 and 3, respectively.     

Trinuclear Gold(I) Complexes with Various Coordination Modes of N,N-dimethyldithiocarbamate

The compounds [Au₃(S₂CNMe₂)₃{ ₃-(PPh₂)₃CH]} (1) and [Au₃(S₂CNMe₂)(-S₂CNMe₂){ ₃-(PPh₂)₃CH}]ClO₄ (2) are obtained by reaction of [Au₃Cl₃{ ₃-(PPh₂)₃CH}] with three equivalents of sodium dimethyldithiocarbamate or two equivalents of the same reagent in the presence of excess NaClO₄. Reaction of 2 with the group 11 metal complexes [AuCl(tht)], CuCl or [Au(C₆F₅)(tht)] takes place with displacement of [M(S₂CNMe₂)]_n (M=Cu, Au) and formation of the new complexes [Au₃X(-S₂CNMe₂){ ₃-(PPh₂)₃CH}]ClO₄ (X=Cl (3), X=C₆F₅ (4)); further reaction of 3 with [Ag(OClO₃)(tht)] (tht=tetrahydrothiophene) affords the dicationic species [Au₃(-S₂CNMe₂){ ₃-(PPh₂)₃CH}(tht)](ClO₄)₂ (5). Treatment of [Au₃Cl₃{ ₃-(PPh₂)₃CH}] with one equivalent of NaS₂CNMe₂ allows the substitution of only one chlorine atom, giving rise to the complex [Au₃Cl₂(S₂CNMe₂){ ₃-(PPh₂)₃CH}] (6), in which the dithiocarbamate ligand acts as monodentate rather than bidentate bridging as observed in compounds 3–5. The crystal structures of complexes 1 and 2 have been established by X-ray diffraction studies and show close gold–gold contacts.     

Reactions of dodecacarbonyltriruthenium with α,β-unsaturated ketones. Crystal and molecular structures of two reaction products

The thermal reactions of Ru₃(CO)₁₂ with RCOCH=CHPh (R=Me, p-MeC₆H₄) in hydrocarbon solvents lead to the formation of a series of complexes, several of which have been isolated as individual compounds by chromatography. The dinuclear complex Ru₂(-H)(CO)₆(-MeCOCH=CPh) and the tetranuclear complex Ru₄(-H)(-CO)(CO)₇(p-MeC ₆H₄ COCH=CPh)(-p-MeC₆H₄COCH=CPh)(₄-p-MeC₆H₃COCH=CHPh) are characterized by an X-ray structural study. The structures of other reaction products are discussed on the basis of spectral data. The reactions are accompanied by reduction of the starting enones to the corresponding unsaturated ketones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1285–1293, July, 1993.     

Reaction of the Hexa-1,3,5-triyne Me3SiC≡CC≡CC≡CSiMe3 with Ru4(CO)13(μ 3-PPh): Parallels with the Chemistry of Alkynes and Diynes

Reaction of Ru₄(CO)₁₃(₃-PPh) (1) with the 1,3,5-hexatriyne Me₃SiCCCCC CSiMe₃ under mild thermal conditions affords initially Ru₄(CO)₁₀(-CO)₂{₄-¹,¹,²-P(Ph)C(CCSiMe₃)C(CCSiMe₃) (2), via the facile formation of a P–C bond in a manner similar to that demonstrated previously with alkynes and diynes. The 62-CVE cluster 2 readily decarbonylates to give crystallographically characterised Ru₄(CO)₁₀(-CO)(₄-PPh){₄-¹,¹,²,²-Me₃SiCCC₂CCSiMe₃} (3). Attempts to further incorporate the pendant alkyne moieties in 3 into the Ru₄ coordination environment were partially successful with Ru₄(CO)₁₀(₄-PPh)(₄-¹,¹,³,³-RC₄R') (4, R/R'=SiMe₃/CCSiMe₃) being formed as a minor product together with the unusual toluene coordinated species Ru₄(CO)₇(⁶-C₆H₅Me)(₄-PPh)(₄-¹,¹,³,³-Me₃SiC₄CCSiMe₄) (5). Cluster 3 reacts with an excess of Me₃SiCCCCCCSiMe₃ to give the open chain cluster Ru₄(CO)₉(₃-PPh){₄-²,²,⁴,⁴,-C₄(CCSiMe₃)(SiMe₃)C₄(CCSiMe₃)₃} (6).     

Cluster chemistry. 85. Addition of a gold acetylide to an Ru5 cluster. X-ray structure of AuRu5(μ5-C2PPh2)(μ-C2Ph)(μ-PPh2)(CO)13(PPh3)

The reaction between Ru₅(₅-C₂PPh₂)(-PPh₂)(CO)₁₃ and Au(C₂Ph)(PPh₃) afforded AuRu₅(₅-C₂PPh₂)(-C₂Ph)(-PPh₂)(CO)₁₃ (PPh₃), in which the Ru₅ cluster has a scorpion geometry; the Au(PPh₃) group bridges one of the Ru-Ru bonds of the Ru₃ triangle, while the C₂Ph group bridges one of the tail Ru-Ru vectors.For Part 84, see Ref. 1.     

Cluster Chemsitry. 96. Penta- and hexa-nuclear ruthenium cluster complexes derived from reactions of cyclopentadienes with Ru5(μ5-C2PPh2)(μ-PPh2)(CO)13

The reactions between Ru₅( ₅-C₂PPh₂)(gm-PPh₂(CO)₁₃ (1) and cyclopentadienes afforded the hexanuclear clusters Ru₆( ₆-C)( ₃-PPh₂)₂(CO)₁₀(-C₅ R ₅) [R ₅ = H₅ (2), H₄Me (3), Me₅ (4)] which contain an encapsulated carbide and a face-capping ₃-CH group, formed by cleavage of CC and CP bonds of the C₂PPh₂ moiety in1. In the reaction with cyclopentadiene, the unusual ligand C₁₃H₁₂O, formed by combination of C₂, CO and two molecules of C₅H₆ (or one molecule of dicyclopentadien), was characterized in the complex Ru₅( ₄-PPh) ( ₄-C₁₃H₁₂O)(-PPh₂(CO)₁₁(-C₅H₅) (5). In the reaction with pentamethylcyclopentadiene, the vinylidene complex Ru₅( ₃-CCHPh)( ₄-PPh)( ₄-PPh) (-PPh₂)(CO)₉(-C₅Me₅) (6) was also formed.     

Reactivity and flexibility in platinum metal clusters

The synthesis, structural properties, and fluxional behaviour of platinum-triosmium and platinum-triruthenium clusters derived from Os₃Pt(-H)₂ (CO)₁₀(PR₃) and Ru₃Pt(-H)(-CC ^t Bu)(CO)₉ (dppe) and related species are described.     

New Molybdenum(V) Complexes Prepared by the Oxidation of Dinuclear Quadruply-Bonded Molybdenum(II) Monothiocarboxylates

Oxidation of molybdenum(II) thiopivalate and thiobenzoate in the presence of -picoline or pyridine results in the formation of dinuclear molybdenum(V) complexes of the general formulae [Mo₂O₂(-O)₂(-SO₄)L₄] with L = -picoline or pyridine and [Mo₂O₂(-O)(-S)(-SO₄)L₄] with L = -picoline. As determined by X-ray structure analysis, two complexes with -picoline differ in their bridging cores: In one complex, two Mo atoms are doubly bridged through two oxygen atoms; in the other, one Mo atom is doubly bridged through oxygen and sulfur atoms. However, they both crystallize together. The product is solvated with -picoline and water molecules. Molybdenum atoms exhibit distorted octahedral coordinations. The same complexes were prepared also through direct reactions of [Mo₂O₃(O₂CCH₃)₄] with thiopivalic and thiobenzoic acid in the presence of -picoline or pyridine. The appearance of the oxo-oxygens and sulfido-sulfur as well as sulfato ligand is explained by the molybdenum-catalyzed oxidation of thiocarboxylates.     

Chemistry of heterometallic phenyl imido and phosphinidene clusters

Triruthenium imido cluster Ru₃(CO)₁₀(₃-NPh)⁽¹⁾ reacts with tungsten hydride LW(CO)₃H to afford heterometallic imido clusters LWRu₂(CO)₈(-H) (₃-NPh), L=Cp, (IIa); L=Cp*, (IIb), whereas the respective phosphinidene complexes LWRu₂(CO)₈(-H)(₃-PPh), L=Cp, (IXa); L=Cp*, (IXb), were generated via reaction of Ru₃(CO)₁₀(-H)(-PPh₂) with CpW(CO)₃H and with CP*W(CO)₃H followed by thermolysis in the presence of carbon monoxide. Their molecular structure, solution dynamics, and the subsequent reaction with hexafluoro-2-butyne are presented.     

New cobalt trimethylacetate complexes with pyridine

The reaction of the tetranuclear trimethylacetate complex Co₄(₃-OH)₂(-OOCCMe₃)₄(²-OOCCMe₃)₂(EtOH)₆ with pyridine in acetonitrile was studied. Two new compounds, viz., the hexanuclear cobalt(ii) complex Co₆py₄(₃-OH)₂(-OOCCMe₃)₁₀ (25% yield) and the unusual ionic compound [Co₃py₃(₃-O)(-OOCCMe₃)₆]⁺[Co₄py(₄-O)(-OOCCMe₃)₇]^– (5% yield), were prepared. The structures of the new compounds were established by X-ray diffraction analysis.     

Cleavage of 1,4-diphenylbuta-1,3-diyne on a ruthenium-cobalt cluster: Synthesis and molecular structure of Co2Ru3(μ4−C2Ph)(μ3−C2Ph)(μ-dppm)(μ-CO)2(CO)9

The reaction between Ru₃(₃-²-PhC₂C=CPh)(-dppm)(CO)₈ and Co₂(CO)₈ afforded dark red Co₂Ru₃(₄-C₂Ph)(₃-C₂Ph)(-dppm)(-CO)₂(CO)₉, shown by an X-ray structure determination to contain a strongly twisted Co₂Ru₃ bow-tie cluster (central Co), to which two PhC₂ units derived from cleavage of the original diyne are attached. One a these is strongly interacting with four metal atoms, the other being attached in the familiar ¹,2²-mode. The dppm ligand remains bridging two of the Ru atoms.     

Unsymmetrical dinuclear cobalt and nickel trimethylacetate complexes

The reaction of the dinuclear complex Co₂(-OOCCMe₃)₂(²-OOCCMe₃)₂bpy₂ (1) with the polymer [Co(OH) _n (OOCCMe₃)_2–n ] _x afforded the unsymmetrical dinuclear complex bpyCo₂(₂-O,²-OOCCMe₃)(₂-O,O"-OOCCMe₃)₂(²-OOCCMe₃) (2). The reaction of 2,2"-dipyridylamine with [Co(OH) _n (OOCCMe₃)_2–n ] _x gave rise to the analogous complex [(C₅H₄N)₂NH]Co₂(₂-O,²-OOCCMe₃)(-OOCCMe₃)₂(²-OOCCMe₃) (3). The reaction of complex 1 with Ni₄(₃-OH)₂(-OOCCMe₃)₄(OOCCMe₃)₂(MeCN)₂[²-o-C₆H₄(NH₂)(NHPh)]₂ (4) produced an isostructural heterometallic analog of complex 2 with composition bpyM₂(₂-O,²-OOCCMe₃)(₂-O,O"-OOCCMe₃)₂(²-OOCCMe₃) (5) (M = Co, Ni; Co : Ni = 1 : 1) and the dinuclear heterometallic complex bpy(HOOCCMe₃)M(-OH₂)(-OOCCMe₃)₂M(OOCCMe₃)₂[o-C₆H₄(NH₂)(NHPh)] (6) (M = Co, Ni; Co : Ni = 0.15 : 1.85). Compounds 2 and 5 exhibit ferromagnetic spin-spin exchange interactions.     

Redox Properties of Trinuclear Osmium Carbonylhydride Clusters with Unsaturated Ligands

Schemes of redox transformations were proposed for osmium carbonylhydride clusters: trinuclear (-H)Os₃(-CR = CHR')(CO)_{1 0} (R = R' = H, Ph; R = H, R' = Ph), (-H)₂Os₃(₃-L)(CO)₉ (L = C = CHPh, CHCPh), tetranuclear CpMnOs₃ (-CH = CHPh)(-H)(-CO)(CO)_{1 1}, and trinuclear Os₃(₃-C = CHPh)(CO)₉. Two-electron reduction of the trinuclear clusters results in elimination of the unsaturated ligand with preservation of the metal framework.     

Synthesis and protonation of an OS3(μ-H)(CO)10(μ-σ,η2-C≡CCMe2OMe) cluster

Triosmium cluster Os₃(-H)(CO)₁₀(--²-CCC Me₂OMe) (1) was obtained by treating OS₃(-H)(-Cl)(CO)₁₀ with LiCCCMe₂OMe. The reaction of cluster1 with HBF₄ · Et₂O at –60 °C leads to the cationic complex [Os₃(-H)(CO)₁₀(-,,²-C=C=C Me₂)]⁺BF₄ ^– (2) with an allenylidene ligand. The^s1H and¹³C NMR spectra of complex2 reveal the temperature dependence caused by migration of hydrocarbon and carbonyl ligands. Thermodynamic parameters were obtained for be exchange process of the allenylidene ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp, 2990–2992, December, 1996.     

Chemistry on the rhomboidal Ru4 faces of the clusters RU4(CO)13(μ-PR2)2: Novel small molecule,ligand, and skeletal transformations

Tetrametal clusters such as Ru₄(CO)₁₃(-PPh₂)₂ and Ru₄(CO)₁₀(-PPh₂)₄ are 64-electron systems and, with five metal-metal interactions, are formally electron rich. In fact these clusters have unusual rhomboidal (or flat butterfly) structures with three or four elongated Ru-Ru bonds. With molecular orbitals antibonding with respect to metal metal interactions occupied in such clusters, facile two electron oxidation or ligand dissociation processes should occur, giving electron precise molecules. The molecule Ru₄(CO)₁₃(-PPh₂)₂ 1a undergoes a remarkable, reversible transformation upon loss of CO affording (-H)Ru₄(CO)₁₀(-PPh₂)[₄-¹(P),¹(P),¹(P),¹,²-{C₆H₄}PPh]3 a cluster which contains a five coordinate phosphido bridge and an orthometallated ² arene ring. This conversion is reversible under CO. These and other results which will be discussed confirm that M₄ clusters with electrons in excess of the expected EAN rule count may exhibit unusual reactivity. The solid-state CP/MAS and static powder³¹P NMR spectra of some of these clusters exhibit^99/101Ru-³¹P couplings, values of which have been measured for the first time.