Reaction of [Ru3(CO)12] with tri(2-furyl)phosphine: Di- and tri-substituted triruthenium and phosphido-bridged diruthenium complexes

Reaction of [Ru₃(CO)₁₂] with tri(2-furyl)phosphine, P(C₄H₃O)₃, at 40 °C in the presence of a catalytic amount of Na[Ph₂CO] furnishes two triruthenium complexes [Ru₃(CO)₁₀{P(C₄H₃O)₃}₂] (1) and [Ru₃(CO)₉{P(C₄H₃O)₃}₃] (2) with the ligand coordinated through the phosphorus atom. Treatment of 1 and 2 with Me₃NO at 40 °C affords the dinuclear phosphido-bridged complexes [Ru₂(CO)₆(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}] (3) and [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(C₄H₃O)₃}] (4), respectively, that are formed via phosphorus–carbon bond cleavage of a coordinated phosphine followed by coordination of the dissociated furyl moiety to the diruthenium center in a σ,π-alkenyl mode. Reaction of [Ru₃(CO)₁₂] with tri(2-furyl)phosphine in refluxing benzene gives, in addition to 3 and 4, low yields of the cyclometallated complex [Ru₃(CO)₉{μ-η¹,η¹-P(C₄H₃O)₂(C₄H₂O)}₂] (5). Treatment of 3 with EPh₃ (E = P, As, Sb) at room temperature yields the monosubstituted derivatives [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}(EPh₃)] (E = P, 8; E = As, 9; E = Sb, 10). Similar reactions of 3 with P(C₄H₃O)₃, P(OMe)₃ and Bu^tNC yield 4, [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(OMe)₃}] (11) and [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}(NCBu^t)] (12), respectively. The molecular structures of complexes 3, 4 and 8 have been elucidated by single crystal X-ray diffraction studies. Each complex contains a bridging σ,π-alkenyl group and while in 4 the phosphine is bound to the σ-coordinated metal atom, in 8 it is at the π-bound atom. Protonation of 3 and 4 gives the hydride complexes [(μ-H)Ru₂(CO)₆(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}]⁺ (6) and [(μ-H)Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(C₄H₃O)₃}]⁺ (7), respectively, while heating 3 with dimethylacetylenedicarboxylate (DMAD) in refluxing toluene gives the cyclotrimerization product, C₆(CO₂Me)₆.     

Activation of Open‐Cage Fullerenes with Ruthenium Carbonyl Clusters

Reactions of the open‐cage fullerene C₆₃NO₂(Py)(Ph)₂ ( 1 ) with [Ru₃(CO)₁₂] produce [Ru₃(CO)₈(μ,η⁵‐C₆₃NO₂(Py)(Ph)₂)] ( 2 ), [Ru₂H(CO)₃(μ,η⁷‐C₆₃N(Py)(Ph)(C₆H₄))] ( 3 ), and [Ru(CO)(Py)₂₍η³‐C₆₃NO₂(Py)(Ph)₂)] ( 4 ), in which the orifice sizes are modified from 12 to 8, 11, and 15‐membered ring, through ruthenium‐mediated C?O and C?C bond activation and formation.     

Darstellung carboxylatsubstituierter Rhenium-Gold-Metallatetrahedrane Re2(AuPPh3)2(μ-PCy2)(CO)7(η1-OC(R)O) (R = H,Me, CF3, Ph, 3,4-(OMe)2C6H3)

Synthesis of Carboxylate Substituted Rhenium Gold Metallatetrahedranes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H, Me, CF₃, Ph, 3,4-(OMe)₂C₆H₃) The reaction of the in situ prepared salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(ax-C(Ph)O)] ( 2 ) with 1,5 equivalents of monocarboxylic acid RCOOH (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e ) in tetrahydrofruan (THF) solution at 60 °C gives within 4 h under release of benzaldehyde (PhCHO) the η¹-carboxylate substituted dirhenium salt Li[Re₂(μ-H)(μ-PCy₂)(CO)₇(η¹-OC(R)O)] (R = H ( 4 a ), Me ( 4 b ), CF₃ ( 4 c ), Ph ( 4 d ), 3,4-(OMe)₂C₆H₃ ( 4 e )) in almost quantitative yield. The lower the pK_a value of the respective carboxylic acid the faster the reaction proceeds. It was only in the case of CF₃COOH possible to prove the formation of the hydroxycarbene complex Re₂(μ-H)(μ-PCy₂)(CO)₇(=C(Ph)OH) ( 5 ) prior to elimination of PhCHO. The new compounds 4 a–4 e were only characterized by ³¹P NMR and ν(CO) IR spectroscopy as they are only stable in solution. They are converted with two equivalents of BF₄AuPPh₃ at 0 °C in a so-called cluster expansion reaction into the heterometallic metallatetrahedrane complexes Re₂(AuPPh₃)₂(μ-PCy₂)(CO)₇(η¹-OC(R)O) (R = H ( 7 a ), Me ( 7 b ), CF₃ ( 7 c ), Ph ( 7 d ), 3,4-(OMe)₂C₆H₃ ( 7 e )) (yield 47–71% ). The expected precursor complexes of 7 a–7 e Li[Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(R)O] ( 8 ) were not detected by NMR and IR spectroscopy in the course of the reaction. Their existence was retrosynthetically proved by the reaction of 7 b with an excess of the chelating base TBD (1,5,7-Triazabicyclo[4.4.0]dec-5-en) forming [(TBD)_xAuPPh₃][Re₂(AuPPh₃)(μ-PCy₂)(CO)₇(η¹-OC(Me)O] ( 8 b ) in solution. The η¹-bound carboxylate ligand in 7 a–7 e can photochemically be converted into a μ-bound ligand in Re₂(AuPPh₃)₂(μ-PCy₂)(μ-OC(R)O)(CO)₆ (R = H ( 9 a ), Me ( 9 b ), CF₃ ( 9 c ), Ph ( 9 d ), 3.4-(MeO)₂C₆H₃ ( 9 e )) under release of one equivalent CO. All isolated cluster complexes were characterized and identified by the following analytical methods: elementary analysis, NMR (¹H, ³¹P) spectroscopy, ν(CO) IR spectroscopy and in the case of 7 d and 9 b by X-ray structure analysis.     

Lewis Base Behavior of Bridging Nitrido Ligands of Titanium Polynuclear Complexes

The Lewis base behavior of μ₃‐nitrido ligands of the polynuclear titanium complexes [{Ti(η⁵‐C₅Me₅)(μ‐NH)}₃(μ₃‐N)] ( 1 ) and [{Ti(η⁵‐C₅Me₅)}₄(μ₃‐N)₄] ( 2 ) to MX Lewis acids has been observed for the first time. Complex 1 entraps one equivalent of copper(I ) halide or copper(I ) trifluoromethanesulfonate through the basal NH imido groups to give cube‐type adducts [XCu{(μ₃‐NH)₃Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}] (X=Cl ( 3 ), Br ( 4 ), I ( 5 ), OSO₂CF₃ ( 6 )). However, the treatment of 1 with an excess (≥2 equiv) of copper reagents afforded complexes [XCu{(μ₃‐NH)₃Ti₃(η⁵‐C₅Me₅)₃(μ₄‐N)(CuX)}] (X=Cl ( 7 ), Br ( 8 ), I ( 9 ), OSO₂CF₃ ( 10 )) by incorporation of an additional CuX fragment at the μ₃‐N nitrido apical group. Similarly, the tetranuclear cube‐type nitrido derivative 2 is capable of incorporating one, two, or up to three CuX units at the μ₃‐N ligands to give complexes [{Ti(η⁵‐C₅Me₅)}₄(μ₃‐N)_4?n{(μ₄‐N)CuX}_n] (X=Br ( 11 ), n=1; X=Cl ( 12 ), n=2; X=OSO₂CF₃ ( 13 ), n=3). Compound 2 also reacts with silver(I ) trifluoromethanesulfonate (≥1 equiv) to give the adduct [{Ti(η⁵‐C₅Me₅)}₄(μ₃‐N)₃{(μ₄‐N)AgOSO₂CF₃}] ( 14 ). X‐ray crystal structure determinations have been performed for complexes 8 – 13 . Density functional theory calculations have been carried out to understand the nature and strength of the interactions of [{Ti(η⁵‐C₅H₅)(μ‐NH)}₃(μ₃‐N)] ( 1′ ) and [{Ti(η⁵‐C₅H₅)}₄(μ₃‐N)₄] ( 2′ ) model complexes with copper and silver MX fragments. Although coordination through the three basal NH imido groups is thermodynamically preferred in the case of 1′ , in both complexes the μ₃‐nitrido groups act as two‐electron donor Lewis bases to the appropriate Lewis acids.     

Derivative des borols: VI. Dehydrierende komplexierung von borolenen mit carbonylmetallen: (borol)metall-komplexe von mangan,eisen und cobalt

The reaction of 2-borolenes and 3-borolenes C₄H₆BR (R = Ph, Me, C₆H₁₁, OMe) with Mn, Fe, and Co carbonyls leads to dehydrogenating complexation with formation of simple, i.e. C-unsubstituted (η⁵-borole)metal complexes. Thus, Mn₂(CO)₁₀ gives the triple-decked complexes (μ-η⁵-C₄H₄BR)[Mn(CO)₃]₂ (R = Ph, OMe). By irradiation of Fe(CO)₅ the half-sandwich complexes Fe(CO)₃ (η⁵-C₄H₄BR) (R = Ph, Me, C₆H₁₁, OMe) are formed, whereas Co₂(CO)₈ yields the dinuclear complexes (μ-CO)₂[Co(CO)(η⁵-C₄H₄BR)]₂ (Co-Co) (R = Ph, Me). A low-temperature X-ray structure determination of Fe(CO)₃(η⁵-C₄H₄BPh) is described in detail.     

Olefin-aminocarbyne coupling in diiron complexes: Synthesis of new bridging aminoallylidene complexes

The bridging aminocarbyne complexes [Fe₂{μ-CN(Me)(R)}(μ-CO)(CO)₂(Cp)₂][SO₃CF₃] (R = Me, 1a; Xyl, 1b; 4-C₆H₄OMe, 1c; Xyl = 2,6-Me₂C₆ H₃) react with acrylonitrile or methyl acrylate, in the presence of Me₃NO and NaH, to give the corresponding μ-allylidene complexes [Fe₂{μ-η¹:η³- C_α(N(Me)(R))C_β(H)C_γ(H)(R′)}(μ-CO)(CO)(Cp)₂] (R = Me, R′ = CN, 3a; R = Xyl, R′ = CN, 3b; R = 4-C₆H₄OMe, R′ = CN, 3c; R = Me, R′ = CO₂Me, 3d; R = 4-C₆H₄OMe, R′ = CO₂Me, 3e). Likewise, 1a reacts with styrene or diethyl maleate, under the same reaction conditions, affording the complexes [Fe₂{μ-η¹:η³-C_α(NMe₂)C_β(R′)C_γ(H)(R″)}(μ-CO)(CO)(Cp)₂] (R′ = H, R″ = C₆H₅, 3f; R′ = R″ = CO₂Et, 3g). The corresponding reactions of [Ru₂{μ-CN(Me)(CH₂Ph)}(μ-CO)(CO)₂(Cp)₂][SO₃CF₃] (1d) with acrylonitrile or methyl acrylate afford the complexes [Ru₂{μ-η¹:η³-C_α(N(Me)(CH₂Ph))C_β(H)C_γ(H)(R′)}(μ-CO)(CO)(Cp)₂] (R′ = CN, 3h; CO₂Me, 3i), respectively.The coupling reaction of olefin with the carbyne carbon is regio- and stereospecific, leading to the formation of only one isomer. C-C bond formation occurs selectively between the less substituted alkene carbon and the aminocarbyne, and the C_β-H, C_γ-H hydrogen atoms are mutually trans.The reactions with acrylonitrile, leading to 3a-c and 3h involve, as intermediate species, the nitrile complexes [M₂{μ-CN(Me)(R)}(μ-CO)(CO)(NC-CHCH₂)(Cp)₂][SO₃CF₃] (M = Fe, R = Me, 4a; M = Fe, R = Xyl, 4b; M = Fe, R = 4-C₆H₄OMe, 4c; M = Ru, R = CH₂C₆H₅, 4d).Compounds 3a, 3d and 3f undergo methylation (by CH₃SO₃CF₃) and protonation (by HSO₃CF₃) at the nitrogen atom, leading to the formation of the cationic complexes [Fe₂{μ-η¹:η³-C_α(N(Me)₃)C_β(H)C_γ(H)(R)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (R = CN, 5a; R = CO₂Me, 5b; R = C₆H₅, 5c) and [Fe₂{μ-η¹:η³-C_α(N(H)(Me)₂)C_β(H)C_γ(H)(R)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (R = CN, 6a; R = CO₂Me, 6b; R = C₆H₅, 6c), respectively.Complex 3a, adds the fragment [Fe(CO)₂(THF)(Cp)]⁺, through the nitrile functionality of the bridging ligand, leading to the formation of the complex [Fe₂{μ-η¹:η³-C_α(NMe₂)C_β(H)C_γ(H)(CNFe(CO)₂Cp)}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (9).In an analogous reaction, 3a and [Fe₂{μ-CN(Me)(R)}(μ-CO)(CO)₂(Cp)₂][SO₃CF₃], in the presence of Me₃NO, are assembled to give the tetrameric species [Fe₂{μ-η¹:η³-C_α(NMe₂)C_β(H)C_γ(H)(CN[Fe₂{μ- CN(Me)(R)}(μ-CO)(CO)(Cp)₂])}(μ-CO)(CO)(Cp)₂][SO₃CF₃] (R = Me, 10a; R = Xyl, 10b; R = 4-C₆H₄OMe, 10c).The molecular structures of 3a and 3b have been determined by X-ray diffraction studies.     

Carbonyl substitution chemistry of some trimetallic transition metal cluster complexes with polyfunctional ligands

The trimetallic clusters [Ru₃(CO)₁₀(dppm)], [Ru₃(CO)₁₂] and [RuCo₂(CO)₁₁] react with a number of multifunctional secondary phosphine and tertiary arsine ligands to give products consequent on carbonyl substitution and, in the case of the secondary phosphines, PH activation. The reaction with the unresolved mixed P/S donor, 1-phenylphosphino-2-thio(ethane), HSCH₂CH₂PHPh ( LH₂), gave two products under various conditions which have been characterised by spectroscopic and crystallographic means. These two complexes [Ru₃(μ-dppm)(H)(CO)₇(LH)] and [Ru₃(μ-dppm)(H)(CO)₈(LH)Ru₃(μ-dppm)(CO)₉], show the versatility of the ligand, with it chelating in the former and bridging two Ru₃ units in the latter. The stereogenic centres in the molecules gave rise to complicated spectroscopic data which are consistent with the presence of diastereoisomers. In the case of [Ru₃(CO)₁₂] the reaction with LH₂ gave a poor yield of a tetranuclear butterfly cluster, [Ru₄(CO)₁₀(L)₂], in which two of the ligands bridge opposite hinge wingtip bonds of the cluster. A related ligand, HSCH₂CH₂AsMe(C₆H₄CH₂OMe), reacted with [RuCo₂(CO)₁₁] to give a low yield of the heterobimetallic Ru-Co adduct, [RuCo(CO)₆(SCH₂CH₂AsMe(C₆H₄CH₂OMe))], which appears to be the only one of its type so far structurally characterised.The secondary phosphine, HPMe(C₆H₄(CH₂OMe)) and its oxide HP(O)Me(C₆H₄(CH₂OMe)) also react with the cluster [Ru₃(CO)₁₀(dppm)] to give carbonyl substitution products, [Ru₃(CO)₅(dppm)(μ₂-PMe(C₆H₄CH₂OMe))₄], and [Ru₃H(CO)₇(dppm)(μ₂,η¹-P(O)Me(C₆H₄CH₂OMe))]. The former consists of an open Ru₃ triangle with four phosphide ligands bridging the metal-metal bonds; the latter has the O atom symmetrically bridging one Ru-Ru bond, the P atom being attached to a non-bridged Ru atom.     

Isolation of New Disilanylene-bridged Bis（cyclopentadienyl）tetracarbonyldiiron Complexes and Molecular Structure of [η^5, η^5-C5H4SiMe（SiMePh2）C5H4]Fe2（CO）2（μ-CO）2

1,2-Diphenyl-1,2-dimethyldisilanylene-bridged bis-cyclopentadienyl complex[η~5,η~5-C_5H_4PhMeSiSiMePh-C_5H_4]Fe_2(CO)_2(μ-CO)_2(1)was synthesized by a modified procedure,from which the trans-isomer 1b that was pre-viously difficult to obtain has been isolated for the first time.More interestingly,two new regio-isomers[η~5,η~5C_5H_4SiMe(SiMePh_2)C_5H_4]Fe_2(CO)_2(μ-CO)_2(2)and [η~5,η~5-C_5H_4Me_2SiSiPh_2C_5H_4]Fe_2(CO)_2(μ-CO)_2(3)were occa-sionally obtained during above process,the novel structures of which opened up new options for further study ofthis type of Si—Si bond-containing transition metal complexes.The molecular structure of 2 has been determinedby the X-ray diffraction method.     

Novel dinuclear and trinuclear ruthenium clusters derived from 2‐aryl‐substituted indenylphosphines via C─H bond cleavage

Treatment of Ru₃(CO)₁₂ with an equivalent of (2‐phenyl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 1 ) and (2‐pyridyl‐1H ‐inden‐1‐yl)dicyclohexylphosphine ( 4 ) in refluxing heptane gave the novel trinuclear ruthenium clusters (μ₃‐η¹:η²:η⁵–2‐phenyl‐3‐Cy₂PC₉H₄)Ru₃(CO)₈ ( 1c ) and [μ₂‐η¹–2‐(pyridin‐2‐yl)‐3‐Cy₂PC₉H₆]Ru₃(CO)₉ ( 4a ), respectively, via C ─ H bond cleavage. (2‐Mesityl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 2 ) reacted with Ru₃(CO)₁₂ in refluxing heptane to give the trinuclear ruthenium cluster [μ‐2‐mesityl‐(3‐Cy₂PC₉H₅)](μ₂‐CO)Ru₃(CO)₉ ( 2c ) via C ─ H bond cleavage and carbonyl insertion. 2‐(Anthracen‐9‐yl)‐1H –inden‐3‐yldicyclohexylphosphine ( 3 ) reacted with Ru₃(CO)₁₂ in refluxing heptane to give the dinuclear ruthenium cluster [μ₂‐η³:η³–2‐(anthracen‐9‐yl)‐3‐Cy₂PC₉H₆]Ru₂(CO)₅ ( 3a ). The structures of 1c , 2c , 3a and 4a were fully characterized using IR and NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. These results suggest that the 2‐aryl substituent on the indenyl ring has a pronounced effect on the reaction and coordination modes of Ru₃(CO)₁₂.     

Synthesis and Structure of a Novel Cluster with Trigonal-bipyramidal Ge_2Ru_3 Core

ＩｎｔｒｏｄｕｃｔｉｏｎＷｅｒｅｃｅｎｔｌｙｒｅｐｏｒｔｅｄａｎｉｎｔｒａｍｏｌｅｃｕｌａｒｔｈｅｒｍａｌｒｅａｒ ｒａｎｇｅｍｅｎｔｂｅｔｗｅｅｎＳｉ—ＳｉａｎｄＦｅ—Ｆｅｂｏｎｄｓｉｎｔｈｅｄｉｎｕ ｃｌｅａｒｉｒｏｎｃｏｍｐｌｅｘ { (Ｍｅ2 ＳｉＳｉＭｅ2 ) [(η5 Ｃ5Ｈ4 )Ｆｅ(ＣＯ) ]2 (μ ＣＯ) 2 } (Ｓｃｈｅｍｅ 1) .1 5Ｔｈｅｔｈｅｒｍａｌｒｅａｒｒａｎｇｅｍｅｎｔｗａｓｌａｔｅｒｅｘｔｅｎｄｅｄｔｏｇｅｒｍａｎｉｕｍ ｉｒｏｎａｎｄｓｉｌｉｃｏｎ ｒｕｔｈｅｎｉ ｕｍａｎａｌｏｇｕｅｓ .6 8Ｔｈ…     

The μ3-cyclopentadienylidene ligand: X-ray structure of [Ru4(CO)5 {P(OMe)3}(μ3-C5H4)2(η-C5H5)2]

UV irradiation of [Ru₂(CO)₄(η-C₅H₅)₂] yields the tri- and tetra-ruthenium complexes [Ru₂(CO)₄(η-C₅H₅){η-C₅H₄Ru(CO)₂(η-C₅H₅)}] and [Ru₄(CO)₆(μ₃-C₅H₄)₂(η-C₅H₅)₂]. The μ₃-C₅H₄ ligand in the latter has been characterised through an X-ray diffraction study on [Ru₄(CO)₅{P(OMe)₃}(μ₃-C₅H₄)₂(η-C₅H₅)₂].     

Unsymmetrical alkyne binding to a triruthenium centre: Oxidative-addition of diphenyl ditelluride to the furyne cluster [Ru3(CO)7(μ-H)(μ3-η-C4H2O){μ-P(C4H3O)2}(μ-dppm)]

Oxidative-addition of PhTe₂Ph to the furyne cluster [Ru₃(CO)₇(μ-H)(μ₃-η²-C₄H₂O){μ-P(C₄H₃O)₂}(μ-dppm)] (1) results in the isolation of four complexes; (i) the previously reported 54-electron cluster [Ru₃(CO)₆(μ₃-Te)₂(μ-TePh)₂(μ-dppm)] (5) which results from elimination of trifuryl phosphine, (ii) the furenyl cluster [Ru₃(CO)₅(μ-η²-C₄H₃O){μ-P(C₄H₃O)₂}(μ-TePh)₂(μ-dppm)] (6) which results from carbon-hydrogen bond formation and (iii) two new 50-electron complexes [Ru₃(CO)₅(μ-H)(μ₃-η²-C₄H₂O){μ-P(C₄H₃O)₂}(μ-TePh)₂(к²-dppm)] (7) and [Ru₃(CO)₄(μ-H){P(C₄H₃O)₃}(μ₃-η²-C₄H₂O){μ-P(C₄H₃O)₂}(μ-TePh)₂(к²-dppm)] (8) both containing unsymmetrical furyne ligands. The structures of all the new compounds have been unambiguously established by single crystal X-ray crystallography. Further reactivity studies have provided a clear understanding of the relative sequence of the key oxidative-addition and reductive-elimination processes, showing that 6 is an intermediate in the formation of 7. DFT calculations have been used to shed light on the unsymmetrical binding of the furyne ligand in 7 and also to show that the adopted position of the heteroatom within the furyne ring can vary within complexes of this type.     

The addition of small molecules to (η-C5H5)2Rh2(CO)(CF3C2CF3) : I. The coordinative-addition of CO,CNR, and some group V donor ligands

Treatment of the μ(η¹)-alkyne complex (η-C₅H₅)₂Rh₂(CO)₂(CF₃C₂CF₃) with trimethylamine-N-oxide results in mono-decarbonylation to give the μ(η²)- alkyne complex (η-C₅H₅)₂Rh₂(μ-CO)(CF₃C₂CF₃). Coordinative addition of a variety of ligands L to the monocarbonyl complex has been achieved at room temperature, and stable adducts (η-C₅H₅)₂Rh₂(CO)L(CF₃C₂CF₃) (L  CO, CNBu^t, PPh₃, PMePh₂, P(OMe)₃, AsPh₃, PF₃ and PF₂(NEt₂)) have been fully characterized by infrared and NMR spectroscopy. In each complex, there is a μ(η¹)-attachment of the hexafluorobut-2-yne and a trans-arrangement of CO and L. The spectroscopic data establish that there is rapid scrambling of CO and L when L  CNBu^t. An unstable adduct is formed when (η-C₅H₅)₂Rh₂(μ-CO)(CF₃C₂CF₃) is dissolved in pyridine.     

A convenient entry into diruthenium chemistry

In boiling toluene, diphenylacetylene is readily displaced from the dimetallocycle [Ru₂(CO)(μ-CO) {μ-C(O)C₂Ph₂} (η-C₅H₅)₂] by a variety of reagents (P(OMe)₃, SO₂, R₂CN₂, Ph₂PCH₂) to produce [Ru₂(CO){P(OMe)₃}(μ-CO)₂ - (η-C₅H₅)₂] or [Ru₂(CO)₂(μ-CO)(μ-L)(η-C₅H₅)₂] (L  SO₂, CR₂, CH₂) in high yield.     

Conversion of allene into μ-dimethylcarbene at a diruthenium centre

Treatment of [Ru₂(CO)(μ-CO) {μ-C(O)C₂Ph₂} (η-C ₅H₅)₂] with allene in toluene at 100°C displaces diphenylacetylene and produces [Ru(CO)(η-C₅H₅)-{η³-C₃H₄Ru(CO)₂(η-C₅H₅)}]; upon protonation a 1-methylvinyl cation [Ru₂(CO)₂(μ-CO){μ-C(Me)CH₂}(η-C₅H₅)₂]⁺ is formed which undergoes nucleophillic attack by hydride to yield the μ-dimethylcarbene complex [Ru₂(CO)₂-(μ-CO)(μ-CMe₂)(η-C₅H₅)₂].     

Catalytic and anticancer activities of sawhorse-type diruthenium tetracarbonyl complexes derived from fluorinated fatty acids

The reaction of fluorinated fatty acids, perfluorobutyric acid (C₃F₇CO₂H), and perfluorododecanoic acid (C₁₁F₂₃CO₂H), with dodecacarbonyltriruthenium (Ru₃(CO)₁₂) under reflux in tetrahydrofuran, followed by addition of two-electron donors (L) such as pyridine, 1,3,5-triaza-7-phosphatricyclo[3.3.1.1]decane, or triphenylphosphine, gives stable diruthenium complexes Ru₂(CO)₄(μ₂-η²-O₂CC₃F₇)₂(L)₂ (1a, L?=?C₅H₅N; 1b, L?=?PTA; 1c, L?=?PPh₃) and Ru₂(CO)₄(μ₂-η²-O₂CC₁₁F₂₃)₂(L)₂ (2a, L?=?C₅H₅N; 2b, L?=?PTA; 2c, L?=?PPh₃). The catalytic activity of the complexes for hydrogenation of styrene under supercritical carbon dioxide has been assessed and compared to the analogous triphenylphosphine complexes with non-fluorinated carboxylato groups Ru₂(CO)₄(μ₂-η²-O₂CC₃H₇)₂(PPh₃)₂ (3) and Ru₂(CO)₄(μ₂-η²-O₂CC₁₁H₂₃)₂(PPh₃)₂ (4). In addition, the cytotoxicities of the fluorinated complexes 1 were also evaluated on several human cancer cell lines (A2780, A549, Me300, HeLa). The complexes appear to be moderately cytotoxic, showing greater activity on the Me300 melanoma cells. Single-crystal X-ray structure analyses of 1a and 3 show the typical sawhorse-type arrangement of the diruthenium tetracarbonyl backbone with two bridging carboxylates and two terminal ligands occupying the axial positions.     

Synthesis,Characterization, and Crystal Structures of Diruthenium Complexes Containing Bridging Salicylato Ligands

The thermal reaction of Ru₃(CO)₁₂ ( 1 ) with salicylic acid, in the presence of triphenylphosphine, pyridine, or dimethylsulfoxide, afforded the dinuclear complexes Ru₂(CO)₄(μ‐O₂CC₆H₄OH)₂L₂ ( 2 ) [L = PPh₃ ( 2a ). C₅H₅N ( 2b ); (CH₃)₂SO ( 2c )]. Complex 2b was further reacted with the aromatic dimmines 2,2′‐dipyridine or 1,10‐phenanthroline to give the cationic diruthenium complexes [Ru₂(CO)₂(μ‐CO)₂(μ‐O₂CC₆H₄OH)(N∩N)₂]⁺ ( 3 ) [(N∩N) = 2,2′‐dipyridine ( 3a ); 1,10‐phenanthroline ( 3b )], which were isolated as their tetraphenylborate salts. All five novel complexes were characterized spectroscopically and analytically. For 2a – 2b and 3a – 3b , single‐crystal X‐ray diffraction studies were also carried out.     

Unusual tetra- and penta-ruthenium complexes from linking of ethylidyne and vinylidene ligands

The complexes [Ru₂(CO)₂(μ-CO)(μ-CMe)(η-C₅H₅)₂]^? and [Ru₂CO₂(μ-CO)(μ-CCH₂)(η-C₅H₅)₂] react together to give [{Ru₂CO)₃(η-C₅H₅)₂}₂(μ-CMeCHCH)]⁺ and [{Ru₃(CO)₃(η-C₅H₅)₃}(μ-CCH₂CHC){Ru₂(CO)₃(η-C₅H₅)₂}], each characterised by X-ray diffraction. The former results from ethylidyne-vinylidene linking followed by an alkylidyne to vinyl rearrangement.     

Mapping the Transformation [{RuII(CO)3Cl2}2]→[RuI2(CO)4]2+: Implications in Binuclear Water–Gas Shift Chemistry

The complete sequence of reactions in the base‐promoted reduction of [{Ru^II(CO)₃Cl₂}₂] to [Ru^I₂(CO)₄]²⁺ has been unraveled. Several μ‐OH, μ:κ²‐CO₂H‐bridged diruthenium(II) complexes have been synthesized; they are the direct results of the nucleophilic activation of metal‐coordinated carbonyls by hydroxides. The isolated compounds are [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐OH)(NP^F‐Am)₂][PF₆] ( 1 ; NP^F‐Am=2‐amino‐5,7‐trifluoromethyl‐1,8‐naphthyridine) and [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)(μ‐OH)(NP‐Me₂)₂][BF₄]₂ ( 2 ), secured by the applications of naphthyridine derivatives. In the absence of any capping ligand, a tetranuclear complex [Ru₄(CO)₈(H₂O)₂(μ³‐OH)₂(μ:κ²‐C,O‐CO₂H)₄][CF₃SO₃]₂ ( 3 ) is isolated. The bridging hydroxido ligand in 1 is readily replaced by a π‐donor chlorido ligand, which results in [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐Cl)(NP‐PhOMe)₂][BF₄] ( 4 ). The production of [Ru₂(CO)₄]²⁺ has been attributed to the thermally induced decarboxylation of a bis(hydroxycarbonyl)–diruthenium(II) complex to a dihydrido–diruthenium(II) species, followed by dinuclear reductive elimination of molecular hydrogen with the concomitant formation of the Ru^I? Ru^I single bond. This work was originally instituted to find a reliable synthetic protocol for the [Ru₂(CO)₄(CH₃CN)₆]²⁺ precursor. It is herein prescribed that at least four equivalents of base, complete removal of chlorido ligands by Tl^I salts, and heating at reflux in acetonitrile for a period of four hours are the conditions for the optimal conversion. Premature quenching of the reaction resulted in the isolation of a trinuclear Ru^I₂Ru^II complex [{Ru(NP‐Am)₂(CO)}{Ru₂(NP‐Am)₂(CO)₂(μ‐CO)₂}(μ₃:κ³‐C,O,O′‐CO₂)][BF₄]₂ ( 6 ). These unprecedented diruthenium compounds are the dinuclear congeners of the water–gas shift (WGS) intermediates. The possibility of a dinuclear pathway eliminates the inherent contradiction of pH demands in the WGS catalytic cycle in an alkaline medium. A cooperative binuclear elimination could be a viable route for hydrogen production in WGS chemistry.     

Reactions of Triruthenium Clusters with Quinolines: X-Ray Structures of [Ru3(μ-CO)(CO)7{μ3-η2-P(C6H5)CH2P(C6H5)2)}{μ-η2-C9H5(CH3)N}] and [Ru3(CO)10(μ-H){μ-η2-C9H6N}]

The reactions of [Ru₃(CO)₁₀(μ-dppm)] 4 with quinolines afforded [Ru₃ (μ-CO)(CO)₇{μ₃-η²-P(C₆H₅)CH₂P(C₆H₅)₂)}{μ-η²-C₉H₅(R)N}] (8, R = 4-Me; 9, R = H) as the major products along with small amounts of known compound [Ru₃(CO)₉{μ₃-η³-P(C₆H₅)CH₂P(C₆H₅)(C₆H₄)}] 5. The molecular structure of 8 has been determined by single crystal X-ray studies. The reaction of 5 with 4-methylquinoline in refluxing cyclohexane afforded 8 and two known dinuclear compounds, [Ru₂(CO)₆{μ-CH₂P(C₆H₅)(C₆H₄)P(C₆H₅}] 10 and [Ru₂(CO)₆ {μ-(C₆H₄)P(C₆H₅)(CH₂)P(C₆H₅}] 11, in 40, 12, and 10% yields, respectively. The compounds 10 and 11 are also formed from the thermolysis of 4 in addition to the major compound 5. The solid state structure of the previously reported [Ru₃(CO)₁₀(η-H){μ-η²-C₉H₆N}] 2a is also reported for comparison.