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).     

Regiospecific substitution of carbonyl by phosphine ligands in hydrocarbyl-substituted carbonyl clusters. Synthesis and spectroscopic characterization of Fe3(CO)8(PPh3)(μ3-η2- ⊥ -EtC2Et) and (η5-C5H5)NiFe2(CO)5(PPh3)(η3-η2- ⊥-C2But)

The complexes Fe₃(CO)₈(PPh₃)(μ₃-η²- ⊥ -EtC₂Et) and (η⁵-C₅H₅)NiFe₂(CO)₅(PPh₃)(η₃-η²- ⊥-C₂Bu^t) have been obtained by treating Fe₃(CO)₉(C₂Et₂) or (Cp)NiFe₂(CO)₆(C₂Bu^t) with PPh₃ under mild conditions; the substituted clustes have been characterized spectroscopically. Structures are proposed in which the phosphine is on the unique metalatom σ-bonded to the alkyne or acetylide moiety. Replacement of CO by PPh₃ ligands rather than by addition, is observed for the formally unsaturated Fe₃(CO)₉(C₂Et₂). Reorientation of the acetylide was expected for (Cp)NiFe₂(CO)₆(C₂Bu^t) upon substitution, but was not observed.     

Synthesis and crystal structure of [(η3-C3H5)(CO)2Mo(μ-S2CPCy3)-Mo(η3-CH2CMeCH2)(CO)2]

A novel dimolybdenum complex [(³-C₃H₅)(CO)₂Mo(-S₂CPCy₃)Mo(³-CH₂CMeCH₂)(CO)₂], obtained by reacting the [(CO)₂(³-C₃H₅)Mo(-S₂CPCy₃)Mo(CO)₃]^– anion with an excess of ClCH₂CMe=CH₂, has been characterized by i.r., ³¹P{¹H}, ¹H- and ¹³C-n.m.r. spectroscopy and by elemental analysis. The crystal structure of the complex, determined by X-ray diffraction, shows a definite preference for the central carbon of the S₂CPCy₃ bridge to bind to the Mo(2) atom coordinated by ³-2-methylallyl, rather than the Mo(1) atom attached to unsubstituted ³-allyl ligand.     

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 synthesis. 42. The synthesis and crystal and molecular structures of the sulfur-bridged platinum-ruthenium carbonyl cluster compounds PtRu3(CO)9 L(PPh3)(μ3-S)2 (L=CO,PPh3) and PtRu4(CO)12(PPh3)(μ4-S)2

Two new mixed metal cluster complexes PtRu₃(CO)₁₀(PPh₃)(₃-S)₂,3 14% yield and PtRu₃(CO)₉(PPh₃)₂(₃-S)₂,4 23% yield were obtained from the reaction of Ru₃(CO)₉(₃-S)₂,1 with Pt(PPh₃)₂(C₂H₄) at 0°C. The cluster of4 consists of a spiked triangle of four metal atoms with two triply bridging sulfido ligands. The reaction of Ru₄(CO)₁₁(₄-S)₂,2 with Pt(PPh₃)₂(C₂H₄) yielded the expanded mixed-metal cluster complex PtRu₄(CO)₁₂(PPh₃)(₄-S)₂,5 in 12% yield. The structure of the cluster5 can be described as a pentagonal bipyramid of five metal atoms and two sulfido ligands with one metal-metal bond missing. Compounds4 and5 were characterized by a single-crystal X-ray diffraction analyses.     

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.     

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.     

Os3(CO)9(μ3-AsC6H4CH3)(μ3-C6H3CH3) synthesis and crystal structure

One of the products of the reaction of the activated cluster Os₃(CO)₁₁(NCMe) with As(p-tol)₃ in refluxing nonane has been shown by spectroscopic and X-ray crystallographic methods to be Os₃(CO)₉(μ₃-AsC₆H₄CH₃)(μ₃-C₆H₃CH₃), which contains a benzyne moiety bonded asymmetrically from one carbon to one osmium via a σ bond and from a second carbon to form a bridge between the remaining two osmium atoms.     

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp1(μ-OH)(CO)10Cl] (2), [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

The trinuclear osmium carbonyl cluster, [Os₃(CO)₁₀(MeCN)₂], is allowed to react with 1 equiv. of [IrCp¹Cl₂]₂ (Cp¹ = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os₃Ir₂(Cp¹)₂(μ-OH)(μ-CO)₂(CO)₈Cl] (1) and [Os₃IrCp¹(μ-OH)(CO)₁₀Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C₅H₃N(NH₂)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os₃IrCp¹(μ-H)(μ-Cl)(η³,μ₃-C₅H₂N(NH₂)Br)(CO)₉] (3) and [Os₃IrCp¹(μ-Cl)₂ (η²,μ₃-C₅H₃N(NH)Br)(CO)₇] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.     

Synthesis and Structure of the Complex [Mo3(μ3-S)(μ2-S2)3(Et2NCS2)3 +Br-

Tri-₂-disulfido-₃-thiotris(diethyldithiocarbamato)-S,S'-triangle-trimolybdenum bromide [Mo₃(₃-S)(₂-S₂)₃(Et₂NCS₂)₃ ⁺Br^- was obtained and characterized.     

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.     

Electronic Structure Calculation for Co_6(μ_6-C)(μ_3-S)_2(CO)_(12) Cluster

ItiswellAnownthametalclusterscontalninganintershhalnon-metalatomven'welImodelforcatalysisofcatalystSorotherphenomenonofsndcesciencef'-=].However.chermStSoftenpuzzleoverthefonnationmechanismandtheintershhalatom.Qfcourse'thehUemoleculeisoneexampleofthecase.Here.weattempttounderstandtheseprOblemsbytheelectronicStrUctUrecalculationOfthecluster.Themoleculargeometwofthecltistercomesfromx-ra}'theonanalysis1']ltbelongstoD3hp'mmetn'.ItisshowninFigUre1.H-Iineatondcorbital5wereadoptedforalIatoms.…     

Dinuclear Ruthenium(II) Carbonyl Complexes Doubly Bridged by a Bromine Atom and a C5H3N-2-C(O)CH2-6-CH2 (Q) Group. Crystal Structures of Ru2(μ-Br)(μ-Q)Br(CO)4(PPh3)(MeOH) and Ru2(μ-Br)(μ-Q)Br(CO)3(PPh3)2

The oxidative addition reaction of 2,6-bis(bromomethyl)pyridine to Ru₃(CO)₁₂ gave scarcely soluble {Ru₂Br₂(-Q)(CO)₄} _n , 1, [Q=C₅H₃N-2-C(O)CH₂-6-CH₂] or a mixture of 1 and the mononuclear complex RuBr(Q)(CO)₃, 2, [Q=C₅H₃N-2-C(O)CH₂-6-CH₂Br] according to the reactant's mole ratio. Further reactions of 1 with some N- and P-donor ligands (L) afforded readily soluble dinuclear complexes, Ru₂(-Br)(-Q)Br(CO) _n (L) _m [n=4, m=1, L=PPh₃ 3a, or py 3b; n=3, m=2, L=PPh₃ 5a, or PPh₂(o-tolyl) 5b]. In this paper, the characterization of these products by the elemental analyses and the spectroscopic methods are described. The X-ray crystal structures of Ru₂(-Br) (-Q)Br(CO)₄(PPh₃)(MeOH), 4, which was obtained by crystallization of 3a from MeOH, and of 5a · (2CHCl ₃ ) are also described. Each of the metal atoms in 4 has a distorted octahedral coordination, while in 5a · (2CHCl ₃ ) one metal atom takes a distorted octahedral geometry and the other pseudooctahedral, which is completed by presenting a Ru ··· Br secondary bonding interaction.     

Chalcogen–acetylide interaction and unusual reactivity of coordinated acetylide with water: synthesis and characterisation of [(η5-C5R5)Fe3(CO)6(μ3-E)(μ3-ECCH2RI)] (R=H,Me; RI=Ph,Fc; E=S,Se) and [(η5-C5R5)MoFe2(CO)6(μ3-S)(μ-SCCH2Ph)] (R=H,Me)

Photolysis of a benzene solution containing [Fe₃(CO)₉(μ₃-E)₂] (E=S, Se), [(η⁵-C₅R₅)Fe(CO)₂(CCR^I)] (R=H, Me; R^I=Ph, Fc), H₂O and Et₃N results in formation of new metal clusters [(η⁵-C₅R₅)Fe₃(CO)₆(μ₃-E)(μ₃-ECCH₂R^I)] (R=H, R^I=Ph, E=S 1 or Se 2; R=Me, R^I=Ph, E=S 3 or Se 4; R=H, R^I=Fc, E=S 5; R=Me, R^I=Fc, E=S 6 or Se 7). Reaction of [Fe₃(CO)₉(μ₃-S)₂]with [(η⁵-C₅R₅)Mo(CO)₃(CCPh)] (R=H, Me), under same conditions, produces mixed-metal clusters [(η⁵-C₅R₅)MoFe₂(CO)₆(μ₃-S)(μ-SCCH₂Ph)] (R=H 8; R=Me 9). Compounds 1–9 have been characterised by IR and ¹H and ¹³C-NMR spectroscopy. Structures of 1, 5 and 9 have been established crystallographically. A common feature in all these products is the formation of new C-chalcogen bond to give rise to a (ECCH₂R^I) ligand.     

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.     

Diphenylphosphine and diphenylphosphido derivatives of [Ru3(μ-H)(μ3-ampy)(CO)9] (Hampy = 2-amino-6-methylpyridine)

The reactions of [Ru₃(μ-H)(μ-ampy)(CO)₉] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh₂H lead to the complexes [Ru₃(μ-H)(μ₃-ampy)(CO)₈(PPh₂H)] (2) or [Ru₃(μ-H)(μ₃-ampy)(CO)₇(PPh₂H)₂] (3), in which the PPh₂H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru₃(μ₃-ampy)(μ-PPh₂)(μ-CO)₂(CO)₆] (4), which contains the PPh₂ ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high ³¹P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru₃(μ-H)(μ₃-ampy)(μ-PPh₂)₂(CO)₆] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric.     

Ligand exchange between metals: synthesis and characterisation of binuclear and trinuclear iron-alkyne complexes. Crystal structures of [(η5-C5H5)2Fe3(CO)3(μ3-CO)(μ-CO)(CF3C2CF3] and [{μ-CF3CC(CF3)S} {Fe(CO)3}2]

Reaction of[(η⁵-C₅H₅)(CO)Fe{μ-C(CF₃)C(CF₃)SMe}₂Fe(CO)(η⁵-C₅H₅)] with Fe₃(CO)₁₂ leads to an exchange of ligands (hexafluorobut-2-yne, cyclopentadienyl or sulphur) between the metal centres and the formation of several new complexes.Two of These, [(η⁵-C₅H₅)₂Fe₃(CO)₃(μ₃-CO)(μ-CO)(CF₃C₂CF₃)] and [{μ-CF₃CC (CF₃)S Fe(CO)₃}₂], have been shown by X-ray diffraction to contain μ₃-η²-| CF₃C₂CF₃ units bridging Fe₃ and Fe₂S triangles, respectively.     

Reactions of Unsaturated Quinoline Triosmium Clusters [Os3(CO)9(μ3-η2-C9H5(4-R)N)(μ-H)] (R=Me or H) with Tetramethylthiourea: X-ray Structures of [Os3(CO)8(μ-η2-C9H5(4-Me)N)(η2-SC(NMe2NCH2Me)(μ-H)2] and [Os3(CO)9(μ-η2-C9H6N)(η1-SC(NMe2)2)(μ-H)]

Treatment of the electronically unsaturated 4-methylquinoline triosmium cluster $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_3\hbox{-}\upeta^{2}\hbox{-}\hbox{C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upmu\hbox{-H})]$ (1) with tetramethylthiourea in refluxing cyclohexane at 81°C gave $[\hbox{Os}_{3}\hbox{(CO)}_{8}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upeta^2\hbox{-SC}(\hbox{NMe}_2\hbox{NCH}_2\hbox{Me})(\upmu \hbox{-H})_2]$ (2) and $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N})(\upeta^1\hbox{-SC}(\hbox{NMe}_2)_2)(\upmu\hbox{-H})]$ (3). In contrast, a similar reaction of the corresponding quinoline compound $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_{3}\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upmu\hbox{-H})]$ (4) with tetramethylthiourea afforded $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upeta^{1}\hbox{-SC(NMe}_{2})_{2})(\upmu\hbox{-H)}]$ (5) as the only product. Compound 2 contains a cyclometallated tetramethylthiourea ligand which is chelating at the rear osmium atom and a quinolyl ligand coordinated to the Os₃ triangle via the nitrogen lone pair and the C(8) atom of the carbocyclic ring. In 3 and 5, the tetramethylthiourea ligand is coordinated at an equatorial site of the osmium atom, which is also bound to the carbon atom of the quinolyl ligand. Compounds 3 and 5 react with PPh₃ at room temperature to give the previously reported phosphine substituted products $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N)(PPh}_{3})(\upmu\hbox{-H)}]$ (6) and $[\hbox{Os}_{3}\hbox{(CO}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N)(PPh}_{3})(\upmu\hbox{-H)}]$ (7) by the displacement of the tetramethylthiourea ligand.     

过渡金属卡宾配合物 VI:单、双核锰和双核铼的铁硫原子簇卡宾配合物-π-C5H5(CO)2MnC(C6H5)(μ-S)(μ-C6H5S)Fe2(CO)6和[π-C5H5(CO)2MC(C6H5)]2(μ-S)2Fe2(CO)6(M=Mn,Re)的合成和波谱

本文报道了锰和铼的阳离子卡拜配合物[π-C5H5(CO)2MCC6H5]BRr4(M=Mn, Re)分别与(μ-苯硫)六羰基二铁和双(μ-锂硫)六羰基二铁阴离子反应生成标题化合物. 产物的组成和结构由元素分析, IR, ^1H NMR和MS分析, 以及7的单晶X射线结构分析确定的. 文中还对合成和波谱研究结果进行了讨论.     

Triphospha-Ferrocenes as Ligands. Crystal Structures of [Fe(η5-C5Me5)(η5-C2 TBu2P3)M(CO)5)], (M= Cr,MO, W) and the Novel ruthenium and Nickel Complexes [Fe(η5-C5Me5) (η5-C2 TBu2P3)Ru3(CO)9] and [Fe(η5-C5Me5)(η5-C2 tBu2P3)Ni(Co)2]2

Abstract

Syntheses and structures of penta- and hexaphosphorus analogues of ferrocene have been described recently¹. Unlike their simple ferrocene analogues, these complexes have further ligating potential towards other transition metal centres by virtue of the availability of the ring phosphorus lone-pair electrons that are not involved in the η⁵-coordination. We now describe the first examples of coordination compounds of the triphospha-ferrocene [Fe(η⁵-C₅Me₅) (η⁵-C₂ ^tBu₂P₃]. In the ruthenium complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃) Ru₃(CO)₉] ² two adjacent phosphorus atoms of the η⁵-C₂ ^tBu₂P₃ ring are interlinked by a ruthenium carbonyl cluster in which all three ruthenium atoms interact with the phosphorus atoms. The tetrametallic nickel complex [Fe(η⁵-C₅Me₅)(η⁵-C₂ ^tBu₂P₃)Ni(CO)₂]₂ ³ represents the first example of intermolecular interlinkage of two phospha-ferrocene systems by two metal centres.