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.     

Cluster chemistry. Synthesis and X-ray structure of Os5(μ5-η2,P-C2PPh2)(μ-PPh2)(CO)13, a complex containing a phosphinoalkylne ligand attached to an open Os5 cluster

Reaction of C₂(PPh₂)₂(dppa) with Os₃(CO)₁₁(NCMe) affords the yellow complex [Os₃(CO)₁₁]₂(μ-dppa); this on heating gives [Os₅(μ₅-η²-P-C₂PPh₂)(μ-PPh₂)(CO)₁₃] in 51% yield, which is shown by an X-ray study to contain a seven electron donor C₂PPh₂ ligand interacting with all five Os₅ atoms of an open Os₅ cluster consisting of three edge fused Os₃ triangles with a “swallowlike” arrangement. The PPh₂ group bridges the non fused edgeof the central triangle. The structure appears to be identical with that described for the equivalent ruthenium complex.     

New electron-deficient alkene and alkyne derivatives of Ru5(μ5-C)(CO)15: The syntheses and crystal structure analyses of Ru5(μ5-C)(CO)13 [C2H2(CO2Me)2] and Ru5(μ5-C)(CO)15 [C2(CO2Me)2]

Treatment of carbido cluster Ru₅(μ ₅-C)(CO)₁₅ with Me₃NO in acetonitrile solution followed by addition of dimethyl maleate or dimethyl acetylene dicarboxylate affords new clusters Ru₅(μ ₅-C)(CO)₁₃[C₂H₂(CO₂Me)₂] (1) and Ru₅(μ ₅-C)(CO)₁₅[C₂(CO₂Me)₂] (2), respectively. Single crystal X-ray structural studies reveal that both complexes contain a wingtip-bridged butterfly pentametallic skeleton. In complex1 the maleate fragment is coordinated to one wingtip Ru atom through its carbon-carbon double bond and to the adjacent Ru atom by the formation of two O → Ru dative bonding interactions, while the acetylene dicarboxylate fragment in2 is best considered as acis-dimetallated alkene, linking one hinge Ru atom and the nearby Ru atom at the bridged position. Crystal data for1: space group P 4₂/n;a=20.199(6),c=13.941(3) Å,Z=8; finalR _F=0.025,R _w=0.026 for 3963 reflections withI>2σ(I). Crystal data for2: space group P2₁/n;a=9.634(3),b=20.062(6),c=17.372(5) Å,β=90.62(2)°,Z=4; finalR _F=0 033,R _w=0.036 for 4683 reflections withI>3σ(I).     

The insertion of acetylene into the formal ruthenium-phosphorus bonds of closo-[Ru4(μ4-PPh)2(μ2-CO)(CO)10. Crystal structure of [Ru4(μ4-PPh){μ4-η3-P(Ph)CHCH}(μ2-CO)(CO)10]

Treatment of closo-[Ru₄(μ₄-PPh)₂(μ₂-CO)(CO)₁₀] with acetylene under ambient conditions leads to the insertion of the acetylene into the skeletal framework of the cluster and the formation of [Ru₄(μ₄-PPh){μ₄-η³-P(Ph)CHCH}(μ₂-CO)(CO)₁₀], the structure of which has been determined X-ray crystallographically.     

Co-ordinatively unsaturated metal cluster compounds: Facile reactivity of the phosphinidene-capped phosphido-bridged triruthenium cluster [Ru3(μ3-PPh)(μ2-PPh2)2(CO)7]

The purple, phosphinidene-capped, phosphido-bridged triruthenium cluster [Ru₃(μ₃-PPh)(μ₂-PPh₂)₂(CO)₇] reacts readily with carbon monoxide, trimethylphosphite, sodium borohydride and diphenylacetylene under mild conditions to afford product mixtures from which [Ru₃(μ-PPh)(μ₂-PPh₂)₂(CO)_7+n] (n = 1, 2 or 3), [Ru₃(μ₃-PPh)(μ₂-PPh₂)₂(CO)₆{P(OMe)₃}], [Ru₃(μ₃-η³-PhPCPhCPh)(μ₂-PPh₂)₂(CO)₆], respectively, can be isolated. The structure of [Ru₃(μ₃-PPh)(μ₂-PPh₂)₂(CO)₆{P(OMe)₃}] has been established X-ray crystallographically.     

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.     

Synthesis and X-ray crystal structure of the electron-deficient metal carbonyl cluster [Os3(CO)5(μ3-H)(μ-H)(μ-PtBu2)2(μ-Ph2PCH2PPh2)]

The reaction of [Os₃(CO)₁₀(μ-dppm)] (1) with ^tBu₂PH in refluxing diglyme results in the electron-deficient metal cluster complex [Os₃(CO)₅(μ₃-H)(μ-P^tBu₂)₂(μ-dppm)] (2) (dppm = Ph₂PCH₂PPh₂) in good yields. The molecular structure of 2 has been established by a single crystal X-ray structure analysis. In contrast to the known homologue [Ru₃(μ-CO)(CO)₄(μ₃-H)(μ-H)(μ-P^tBu₂)₂(μ-dppm)] (3), no bridging carbonyl ligand was found in 2. The electronically unsaturated cluster 2 does not react with carbon monoxide under elevated pressure, therefore 2 seems to be coordinatively saturated by reason of the high steric demands of the phosphido ligands.     

Photochemically promoted regiospecific P–C bond cleavage in the diruthenium compound Ru2(CO)2(bmf): X-ray diffraction structure of Ru2(CO)6[μ-C=C(PPh2)C(O)OCH(OMe)](μ-PPh2)

The ruthenium cluster Ru₃(CO)₁₂ reacts with the diphosphine ligand 3,4-bis(diphenylphosphino)-5-methoxy-2(5H)-furanone (bmf) in refluxing toluene to furnish the donor–acceptor compound Ru₂(CO)₂(bmf) as a 1?:?1 mixture of diastereomers. Photolysis of Ru₂(CO)₂(bmf) using 366?nm light leads to the oxidative cleavage of a P–C bond and formation of the phosphido-bridged complex Ru₂(CO)₆[μ-C=C(PPh₂)C(O)OCH(OMe)](μ-PPh₂). The regioselective Ph₂P–C(furanone ring) bond activation attendant upon optical excitation is traced to the phosphine group that was β to the furanone carbonyl group, as established by X-ray analysis of one of the diastereomers of Ru₂(CO)₆[μ-C=C(PPh₂)C(O)OCH(OMe)](μ-PPh₂). Both diruthenium products have been fully characterized in solution by IR and NMR (¹H and ³¹P) spectroscopies and elemental analyses. The observed regioselectivity associated with the P–C bond activation in Ru₂(CO)₂(bmf) is discussed with respect to the chemistry of other bmf-substituted compounds prepared by our groups.     

Cluster chemistry: L. Trapping of arylnitrenes formed by cleavage of azoarenes in reactions with M3(CO)12 (M = Fe or Ru): X-ray structure of Ru3(μ3-NPh)2(μ-dppm)(CO)7

Trinuclear products obtained from reactions between M₃(CO)₁₂ (M = Fe or Ru) and azobenzenes are shown to have the structure M₃(μ₃-NAr)₂(CO)₉, rather than the o-semidine formulation proposed earlier. ETC CO-substitution reactions are similar to those of Ru₃(CO)₁₂, with isocyanides occupying axial sites and tertiary phosphines and phosphites occupying equatorial sites on the Ru₃(μ₃-NPh)₂(μ-dppm)(CO)₇, in which the dppm ligand spans the non-bonded Ru … Ru vector.     

New Mixed Metal Cluster Complexes Containing Platinum. The Synthesis and Structural Characterizations of PtFe4(CO)12(COD)(μ5-C) and PtFe4(CO)12(PMe2Ph)2(μ5-C)

The new mixed metal carbide containing cluster compounds PtFe₄(CO)₁₂(COD)(₅-C) 1 and PtFe₄(CO)₁₂(PMe₂Ph)₂(₅-C), 2 were obtained by metal–metal exchange reactions between [Et₄N]₂[Fe₅(C)(CO)₁₄] with Pt(COD)Cl₂ in the presence of TIPF₆ and Pt(PMe₂Ph)₂Cl₂, respectively. Compound 1 was also obtained by the reaction of Fe₅(CO)₁₅(₅-C) with Pt(COD)₂ in the presence of UV irradiation but in a lower yield. Both compounds were characterized by a combination of IR, ¹H NMR and single crystal x-ray diffraction analyses. Both complexes consists of a square pyramidal cluster of five metal atoms with an interstitial carbido ligand in the center of the square base. The phosphine ligands in 2 undergo a dynamical intramolecular interchange at a rate that is fast on the ¹H NMR time scale at 45°C, G (at 318 K)=15.1 kcal/mol.     

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.     

Synthesis and crystal structure of Ru3(CO)6(μ3-PPhCH2PPh2)(μ3-CyNC)- (CyNC)2 (Ph), an open trinuclear cluster complex containing an isocyanide ligand acting as a 4-electron donor

Moderate heating of Ru₃(CO)₁₀(dppm) with CyNC (1:3) for 2 h under nitrogen, 68°C and purification by TLC affords moderate yield of the yellow complex Ru₃(CO)₆(μ₃-PPhCH₂PPh₂)(μ₃-CyNC) (Cy-NC)₂(Ph) (1), which has been shown by X-ray crystallography to contain an open Ru₃ cluster with one isocyanide ligand acting as a 4e donor and bonded to all three metal atoms, representing a novel type of bonding of isocyanide on a Ru₃ cluster. Another interesting feature of 1 is the trapping on the cluster of the phenyl group lost from the dppm ligand.     

Further studies of the reactions of PtRu5(μ6-C)(CO)16 with alkynes: The preparation and structural characterizations of PtRu5(CO)13(μ-EtC2Et)(μ3-EtC2Et)(μ5-C) and Pt2Ru6(CO)17(μ-η5-Et4C5)(μ3-EtC2Et) (μ6-C)

The reaction of PtRu₅(CO)₁₆(μ₆-C),1 with 3-hexyne in the presence of UV irradiation produced two new electron-rich platinum-ruthenium cluster complexes PtRu₅(CO)₁₃(μ-EtC₂Et)(μ₃-EtC₂Et)(μ₅-C),2 (20% yield) and Pt₂Ru₆(CO)₁₇(μ-η⁵-Et₄C₅)(μ₃-EtC₂Et) (μ₆-C),3 (7% yield). Both compounds were characterized by single-crystal X-ray diffraction analyses. Compound2 contains of a platinum capped square pyramidal cluster of five ruthenium atoms with the carbido ligand located in the center of the square pyramid. A EtC₂Et ligand bridges one of the PtRu₂ triangles and the Ru-Pt bond between the apical ruthenium atom and the platinum cap. The structure of compound3 consists of an octahedral PtRu₅ cluster with an interstitial carbido ligand and a platinum atom capping one of the PtRu₂ triangles. There is an additional Ru(CO)₂ group extending from the platinum atom in the PtRu₅ cluster that contains a metallated tetraethylcyclopentadienyl ligand that bridges to the platinum capping group. There is also a EtC₂Et ligand bridging one of the PtRu₂ triangular faces to the capping platinum atom. Compounds2 and3 both contain two valence electrons more than the number predicted by conventional electron counting theories, and both also possess unusually long metal-metal bonds that may be related to these anomalous electron configurations. Crystal data for2, space group Pna2₁,a=19.951(3) Å,b=9.905(2) Å,c=17.180(2) Å,Z=2, 1844 reflections,R=0.036; for3, space group Pna2₁,α=13.339(1) Å,b=14.671(2) Å,c=11.748(2) Å, α=100.18(1)°, β=95.79(1)°, γ=83.671(9)°,Z=2, 3127 reflections,R=0.026.     

Cluster Complexes of Polythioether Macrocycles: The Synthesis and Molecular Structures of Ru6(CO)13(cis-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C) and Ru6(CO)13(trans-SCH2 CHMe(CH2SCH2CHMe)2CH2)(μ6-C)

The reaction of a mixture of cis-3,7,11-trimethyl-1,5,9-trithiacyclododecane, cis-Me₃12S3, 1 and trans-3,7,11-trimethyl-l,5,9-trithiacyclododecane, trans-Me₃12S3, 2, with Ru₆(CO)₁₇(μ ₆-C), 3, yielded three new cluster compounds Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 4, and two isomers of Ru₆(CO)₁₃(μ-η³-cis-SCH₂CHMe(CH₂SCH₂CHMe)₂CH₂)(μ ₆-C) 5a and 5b. The molecular structures of 4 and 5b were established by single crystal X-ray diffraction analyses. In both complexes, the macrocycles have adopted tridentate coordination with one of the sulfur atoms in a bridging position. Two carbonyl ligands occupy bridging positions in each compound. Crystal Data for 4·Me₂CO: space group=P2₁/n, a=11.295(1) Å, b=17.547(3) Å, c=20.318(3) Å, β=93.71(1)°, Z=4, 2900 reflections, R=0.025. Crystal Data for 5b·1.5 C₆H₆: space group=Pbca, a=31.8900(8) Å, b=23.4330(6) Å, c=21.6240(4) Å, Z=16, 12163 reflections, R=0.040.     

Solid–Gas Hydrogenation of Hex-3-yne and 1,4-Cyclohexadiene in the Presence of Ru3(CO)9(μ-H)(μ-PPh2), Ru3(CO)10(μ-H)(μ-PPh2), Ru3(CO)7(μ-PPh2)2(C6H4), and Ru4(CO)11(μ4-PPh)(C6H4) Deposited on Pyrex Glass, Silica, and Alumina

The title complexes were tested in the hydrogenation of hex-3-yne and of 1,3- and 1,4-cyclohexadiene (CHD) under solid–gas conditions. The clusters were deposited on three “standard” supports, that is, pyrex glass, alumina, and silica. All the clusters, particularly (μ-H)Ru₃(CO)₁₀(PPh₂), show hydrogenation activity. However, they are not particularly selective toward the formation of monoenes; “disproportionation” of 1,3- and 1,4-CHD to hydrogenated products and benzene also occurs. The hydrogenation activity of the clusters is dependent on their nature, the type of substrate, and the characteristics of the supporting material; silica and pyrex glass are usually more active than alumina. Attempts at detecting the formation of organometallic intermediates or by-products (through IR spectroscopy) were made. HRTEM was used to check for eventual decomposition on some supports.     

Easy Access to Phosphido-Selenido Clusters. Reaction of [Ru3(CO)12] with Ph2(pyth)PSe {pyth=5-(2-Pyridyl)-2-Thienyl} and Crystal Structure of [Ru3(μ3-Se)(μ-PPh2)(μ-pyth)(CO)6{P(pyth)Ph2}]

The reaction of [Ru₃(CO)₁₂] with Ph₂(pyth)PSe (pyth=5-(2-pyridyl)-2-thienyl) allows to obtain two novel clusters [Ru₃(₃-Se)₂(CO)₇{P(pyth)Ph₂}₂] 1 and [Ru₃(₃-Se)(-PPh₂)(-pyth)(CO)₆{P(pyth)Ph₂}] 2 in satisfactory yields. The first one exhibits the well-known bicapped, open triangular, 50-electron nido-core, whereas 2, whose crystal structure has been determined, shows the rather rare Ru₃Se tetrahedron with the Ph₂P and pyth fragments as side-bridging ligands. Morever cluster 2 belongs to the exiguous family of selenido-phosphido clusters not easily achievable by other routes.     

Stereochemical aspects of the conversion of cyclopentadienylruthenium alkoxycarbene to the corresponding acetylide complexes. Crystal structure of [(η-C5H5)Ru(Ph2PCHMeCHMePPh2)(CCPh)]

Reactions of [(η-C₅H₅)Ru(Diphosphine){C(OCH₃)CH₂C₆H₅}]PF₆ complexes with CH₃MgBr give the corresponding phenylacetylide [(η-C₅-H₅)-Ru(Diphosphine)CCC₆H₅] complexes. A crystal structure determination has been carried out for the product in which the diphosphine is rac-1,2-dimethyl-1,2-ethanediylbis(diphenylphosphine). For the complexes in which the diphosphine is (R)-1,2-propanediylbis(diphenylphosphine), the stereo-chemical outcome of the reaction implies retention of configuration at the metal atom.     

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

Synthesis of 62-electron square planar clusters with group 15 and 16 main group atoms: Structural characterization of Ru4(CO)11(μ4-PPh)(μ4-S) and Ru4(CO)10(μ4-PPh)(μ4-Se)(PEt3): Bonding preferences in cappingNido Ru4(CO)13(μ3-PPh)

Thecloso octahedral cluster Ru₄(CO)₁₁(μ₄-PPh)(μ₄-S)1 and selenium and tellurium analogues, the first examples of unsaturated ruthenium clusters with a planar metal core and different main group 15 and 16 atoms have been synthesized fromnido Ru₄(CO)₁₃(μ₃-PPh). An X-ray analysis of1 and Ru₄(CO)₁₀(μ₄-PPh)(μ₄-Se)(PEt₃)2a has confirmed thetrans disposition of phosphorus and group 16 main group fragments.