The interconversion of η5 and η3 hapticities in cycloheptadienyl complexes of molybdenum and tungsten

[Mo(CO)₄(η⁵-C₇H₉)]⁺ (1) reacts with acetonitrile to give [Mo(CO)₂(NCMe)₃(η³-C₇H₉)]⁺ (3), which is precursor of a wide reange of η⁵-cycloheptadienyl complexes [Mo(CO)₂L₂(η⁵-C₇H₉)]⁺ [6, L = PPH₃; 7, L₂ = Ph₂PCH₂PPh₂; 8, L₂ = 1,3-cyclohexadiene; 9, L₂ = 2,2′-dipyridyl]; 9 reacts reversibly with NCMe to give [Mo(CO)₂(NCMe)(dipy)(η³-C₇H₉)]⁺ (10).     

The synthesis of some mixed metal cluster complexes of osmium with cobalt and iron

The reactions of cis-dihydridotetracarbonylosmium, H₂Os(CO)₄ with both Fe₂(CO)₉, and Co₂(CO)₈ have been studied at room temperature. With Fe₂(CO)₉ the major product is Fe₂Os(CO)₁₂ and H₂FeOs₃(CO)₁₃ was obtained as a minor product. With Co₂(CO)₈, Co₂Os(CO)₁₁ and H₂Co₂Os₂(CO)₁₂ are obtained, along with an unstable compound which was identified mass spectrometrically as HOsCo(CO)₈. Os(CO)₅ reacts under UV irradiation with Co₂(CO)₈ to give Co₂Os(CO)₁₁. The main product of the reaction of H₂Os₂(CO)₈ with Fe₂(CO)₉ is FeOs₂(CO)₁₂.     

Kristallstrukturelle,Festkörper‐31P‐CP/MAS‐NMR,TOSS, 31P‐COSY‐NMR und mechanistische Beiträge zur Koordinationschemie des Octacarbonyldicobalts mit den Liganden Bis(diphenylphosphanyl)amin,Bis(diphenylphosphanyl)methan und 1,1,1‐Tris(diphenylphosphanyl)ethan

Chemistry of Polyfunctional Molecules. 133. X‐Ray Crystal Structural, Solid‐state ³¹P CP/MAS NMR, TOSS, ³¹P COSY NMR, and Mechanistic Contributions to the Co‐ordination Chemistry of Octacarbonyldicobalt with the Ligands Bis(diphenylphosphanyl)amine, Bis(diphenylphosphanyl)methane, and 1,1,1‐Tris(diphenylphosphanyl)ethane Co₂(CO)₈ reacts with bis(diphenylphosphanyl)amine, HN(PPh₂)₂ (Hdppa, 1 ), in two steps to afford the known compound [Co(CO)(Hdppa‐κ²P)₂][Co(CO)₄] · 2 THF ( 6 a · 2 THF). The intermediate [Co(CO)₂(Hdppa‐κ²P) · (Hdppa‐κP)][Co(CO)₄] · dioxane · n‐pentane ( 5 · dioxane · n‐pentane) was isolated for the first time and was characterized by X‐ray analysis. The cation 5 ⁺ exhibits a slightly distorted trigonal‐bipyramidal geometry. Detailed ³¹P‐NMR investigations (solid‐state CP/MAS NMR, TOSS, ³¹P‐COSY, ³¹P‐EXSY) showed that the additional tautomer [Co(CO)₂(Hdppa‐κ²P)(Ph₂P–N=P(H)Ph₂‐κP)]⁺ ( 5 ′⁺) is present in solution. The tautomer equilibrium is slow in the NMR time scale. In contrast to the solid state only tetragonal pyramidal species of 5 are found in solution. At –90 °C there is slow exchange between the three diastereomeric species 5 a ⁺– 5 c ⁺. Compound 5 forms [Co(CO) · (Hdppa‐κ²P)₂]BPh₄ · THF ( 6 b · THF) in THF with NaBPh₄ under CO‐Elimination. A X‐ray diffraction investigation shows that the cation 6 ⁺ consists of a slightly distorted trigonal‐bipyramidal co‐ordination polyeder. However, a distorted tetragonal‐pyramidal structure has been found for the cation 7 ⁺ of the related compound [Co(CO)(dppm)₂][Co(CO)₄] · 2 THF ( 7 · 2 THF; dppm = bis(diphenylphosphanyl)methane, Ph₂PCH₂PPh₂). A comparison with the known [8] trigonal‐bipyramidal stereoisomer, ascertained for 7 ⁺ of the solvent‐free 7 , is described. In solutions of 6 a · 2 THF and 7 · 2 THF ¹³C{¹H}‐ and ³¹P{¹H}‐NMR spectra indicate an exchange of all CO and organophosphane molecules between cobalt(I) cation and cobalt(–I) anion. A concerted mechanism for the exchange process is discussed. CO elimination leads to discontinuance of the cyclic mechanism by forming binuclear substitution products such as the isolated Co₂(CO)₂ · (μ‐CO)₂(μ‐dppm)₂ · 0.83 THF ( 8 · 0.83 THF), which was characterized by spectroscopy and X‐ray analysis. For the dissolved [Co(CO)₂CH₃C(CH₂PPh₂)₃][Co(CO)₄] · 0.83 n‐pentane ( 9 a · 0.83 n‐pentane) no CO and triphos exchange processes between the cation and the anion are observed. Metathesis of 9 a · 0.83 n‐pentane with NaBPh₄ yields [Co(CO)₂CH₃C(CH₂PPh₂)₃]BPh₄ ( 9 b ) which has been characterized by single‐crystal X‐ray analysis. The cation shows a small distorted tetragonal‐pyramidal structure.     

Synthesis and Characterization of Cobalttelluride Clusters with the Cubic Body-Centered Co9Te6(CO)8 Core

Reduction of Cp₂NbTe₂H (Cp=tBuC₅H₄) with CH₃Li results in a red-violet solution which reacts with Co₂(CO)₈ to give the neutral cluster {Cp₂Nb(CO)}₂[Co₉Te₆(CO)₈] (2) and a mixture of salts, from which [Na(THF)₆][Co₉Te₆(CO)₈] (4) was obtained by crystallization from THF in very poor yield, probably due to Na impurities in CH₃Li. Clusters 2 (123 valence electrons) and 4 (122 valence electrons) possess hexacapped cubic Co@Co₈ cores. The structure of 2 was identified by comparison of spectroscopic data with those of parent clusters: Two Cp₂Nb(CO) fragments are fixed at two opposite ₄-Te bridges of the Co₉Te₆(CO)₈ skeleton. A crystal structure determination of 4 shows this compound to contain discrete ions. Nearly equal diameters of ca. 10.5Å for the [Co₉Te₆(CO)₈]^– anion and the octahedral [Na(THF)₆]⁺ cation as well as electrostatic interactions between them and attractive C–HO contacts may be responsible for the formation of layers throughout the crystal.     

Salts of Anionic Metal Carbonyl Clusters with Cryptand[2.2.2](Na+), DB‐18‐crown‐6(Na+), and Paramagnetic Cp*2Cr+ Cations Obtained by Reduction

Reduction of neutral metal clusters (Co₄(CO)₁₂, Ru₃(CO)₁₂, Fe₃(CO)₁₂, Ir₄(CO)₁₂, Rh₆(CO)₁₆, {CpMo(CO)₃}₂, {Mn(CO)₅}₂) by decamethylchromocene (Cp*₂Cr) or sodium fluorenone ketyl in the presence of cryptand[2.2.2] and DB‐18‐crown‐6 was studied. Nine new salts with paramagnetic Cp*₂Cr⁺, cryptand[2.2.2](Na⁺), and DB‐18‐crown‐6(Na⁺) cations and [Co₆(CO)₁₅]^2– ( 1 , 2 ), [Ru₆(CO)₁₈]^2– ( 3 – 4 ) dianions, [Rh₁₁(CO)₂₃]^3– ( 6 ) trianions, and new [Ir₈(CO)₁₈]^2– ( 5 ) dianions were obtained and structurally characterized. The increase of nuclearity of clusters under reduction was shown. Fe₃(CO)₁₂ preserves the Fe₃ core under reduction forming the [Fe₃(CO)₁₁]^2– dianions in 7 . The [CpMo(CO)₃]₂ and [Mn(CO)₅]₂ dimers dissociate under reduction forming mononuclear [CpMo(CO)₃]^– ( 8 ) and [Mn(CO)₅]^– ( 9 ) anions. In all anions the increase of negative charge on metal atoms shifts the bands attributed to carbonyl C–O stretching vibrations to smaller wavenumbers in agreement with the elongation of the C–O bonds in 1 – 9 . In contrast, the M–C(CO) bonds are noticeably shortened at the reduction. Magnetic susceptibility of the salts with Cp*₂Cr⁺ is defined by high spin Cp*₂Cr⁺ (S = 3/2) species, whereas all obtained anionic metal clusters and mononuclear anions are diamagnetic. Rather weak magnetic coupling between S = 3/2 spins is observed with Weiss temperature from –1 to –11 K. That is explained by rather long distances between Cp*₂Cr⁺ and the absence of effective π–π interaction between them except compound 7 showing the largest Weiss temperature of –11 K. The {DB‐18‐crown‐6(Na⁺)}₂[Co₆(CO)₁₅]^2– units in 2 are organized in infinite 1D chains through the coordination of carbonyl groups of the Co₆ clusters to the Na⁺ ions and π–π stacking between benzo groups of the DB‐18‐crown‐6(Na⁺) cations.     

Reactions of nitrosonium ion with anionic carbonyl monomers and clusters. Crystal and molecular structure of FeCo2(μ3-NH)(CO)9

The reactions of several mono- and poly-nuclear carbonyl metallates with nitrosonium ion have been studied. Besides simple substitution of a carbon monoxide with NO⁺ some reactions yielded products containing other nitrogeneous ligands. When [CoRu₃(CO)₁₃]^? reacts with NO⁺, low yields of the new nitrido cluster CoRu₃N(CO)₁₂ are formed. Prior conversion of [CoRu₃(CO)₁₃]^? to the new hydrido cluster [H₂CoRu₃(CO)₁₂]^? under hydrogen, followed by nitrosylation, forms the new imido cluster H₂Ru₃(NH)(CO)₉ in very low yield. The reaction of [FeCO₃(CO)₁₂]^? with NO⁺ also generates an imido cluster, FeCo₂(NH)(CO)₉, in 15% yield. This cluster has been characterized by X-ray crystallography and was found to be similar to the tricobalt alkylidyne clusters. (Triclinic crystal system, P$\text{1}$ space group, Z=2, a 6.787(1), b 8.016(1), c 13.881(2) Å, α 95.50(1), β 100.77(1), γ 107.93(1)°. Modifications of the nitrosylations using NO⁺ were studied. In particular, the addition of triethylamine or N-t-butylbenzaldimine allowed the use of NO⁺ in THF without solvent decomposition. With [CpMo(CO)₃]^? and [CpFe(CO)₂]^? the N-nitrosoiminium species appears to form transient alkylmetals which further react to give the dimers [CpMo(CO)₃]₂ and [CpFe(CO)₂]₂.     

Reactions of 1,1,3,3-tetramethyldisilazane with dicobalt octacarbonyl and iron pentacarbonyl. Thermal decomposition of the cobalt and iron carbonyl silazane complexes

The reaction of (HMe₂Si)₂NH with Co₂(CO)₈ gives the complex [Co₂(CO)₇(SiMe₂)₂NH₂]⁺[Co(CO)₄]⁻. Its thermal decomposition starts with dissociation into the “acid” HCo(CO)₄ and the “base” Co₂(CO)₇(SiMe₂)₂NH. After that, the base and the initial complex decompose further under the action of HCo(CO)₄. The final products of this reaction are CO, NH₃, Co, volatile dimethylcyclosilazane, and a solid residue consisting of cobalt particles encapsulated into a polymethylsiloxane matrix and possessing properties of mixed para- and ferromagnetics with an ultimate specific magnetization of 64–74 G g⁻¹. Tetramethyldisilazane reacts with iron pentacarbonyl under UV irradiation to give relatively stable 1,3-bis(tetracarbonylthydrideiron)-1,1,3,3-tetramethyldisilazane. This product contains Fe−H…N hydrogen bonds, which stabilize it against dehydrogenation and cyclization to diironcyclodisilazane. Thermal decomposition of this product was investigated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2537–2544, December, 1998.     

The preparation,characterisation and some reactions of Os3(CO)9(μ2-H)(μ3-SR) (R  Me or Et)

The complex Os₃(CO)₉(μ₂-H)₂(μ₃-S) reacts with KOH/MeOH to produce the anionic complex [Os₃(CO)₉(μ₂-H)(μ₃-S)^?, which reacts in turn with RO⁺ (R = Me, Et) to form HOs₃(CO)₉SR. This complex is especially reactive towards ligands L (L = C₂H₄, CO, PR₃ and MeCN) to generate complexes of the type Os₃(CO)₉(μ₂-H)(μ₂-SR)(L). At 125°C the complex Os₃(CO)₉(μ₂-H)(μ₂-SR)(C₂H₄) (in the presence of C₂H₄) ejects RH and CO to form Os₃(CO)₈(μ₂-H)?(μ₃-S)(CHCH₂). The structures of the new complexes are described and the probable reaction pathways discussed.     

Digermanium polycobalt carbonyls formed by addition reactions of GeH bonds: [Co4(CO)13Ge(GeMe2)] and [Co6(CO)20Ge2]

GeMe₂H₂ reacts under mild conditions with [{Co₂(CO)₇}₂Ge] to replace one bridging CO and give [Co₄(CO)₁₃Ge(GeMe₂)]. GeH₄ similarly yields a trace of [Co₆(CO)₂₀Ge₂], which may be made in high yield from [Co₂(CO)₈] and Ge₂H₆ or Me₂Si(GeH₃)₂. Spectroscopic evidence suggests structures of linked GeCo₂ triangles.     

Synthesis and crystal structure of a heterodinuclear complex with a bridged ethenyl ligand FeCo(CO)7(μ-CH=CPhH)

[Fe₂(CO)₆(μ-CO)(μ-CHCPhH)]⁻ reacts with Co₂(CO)₈ at room temperature to give the neutral heterodinuclear complex FeCo(CO)₇(μ-CHCPhH), which has been characterized by elemental analysis and spectroscopic (mass, IR and ¹H NMR) methods and by determination of its structure by X-ray diffraction.     

Reactivity of Cyanide and Thiocyanate Towards the Nitrosyl Carbonyl [Co(CO)3(NO)]

The reaction of equimolar amounts of [Co(CO)₃(NO)] and [PPN]CN, PPN⁺ = (PPh₃)₂N⁺, in THF at room temperature resulted in ligand substitution of a carbonyl towards the cyanido ligand presumably affording the complex salt PPN[Co(CO)₂(NO)(CN)] as a reactive intermediate species which could not be isolated. Applying the synthetic protocol using the nitrosyl carbonyl in excess, the title reaction afforded unexpectedly the novel complex salt PPN[Co₂(μ-CN)(CO)₄(NO)₂] ( 1 ) in high yield. Because of many disorder phenomena in crystals of 1 the corresponding NBu₄⁺ salt of 1 has been prepared and the molecular structure of the dinuclear metal core in NnBu₄[Co₂(μ-CN)(CO)₄(NO)₂] ( 2 ) was determined by X-ray crystal diffraction in a more satisfactory manner. In contrast to the former result, the reaction of [PPN]SCN with [Co(CO)₃(NO)] yielded the mononuclear complex salt PPN[Co(CO)₂(NO)(SCN-κN)] ( 3 ) in good yield whose molecular structure in the solid was even determined and its composition additionally confirmed by spectroscopic means.     

Infrared Photodisssociation Spectroscopy of Boron Carbonyl Cation Complexes

The boron carbonyl cation complexes B(CO)₃⁺, B(CO)₄⁺ and B₂(CO)₄⁺ are studied by infrared photodissociation spectroscopy and theoretical calculations. The B(CO)₄⁺ ions are characterized to be very weakly bound complexes involving a B(CO)₃⁺ core ion, which is predicted to have a planar DD_3h structure with the central boron retaining the most favorable 8-electron configuration. The B₂(CO)₄⁺ cation is determined to have a planar D_2h structure involving a B-B one and half bond. The analysis of the B-CO interactions with the EDA-NOCV method indicates that the OC→B σ donation is stronger than the B→CO π back donation in both ions.     

Some chemical properties of (arene)nonacarbonyltetracobalt complexes and the preparation of (arene)octacarbonyltetracobalt trialkylphosphites

In reactions of Co₄(CO)₉(arene) with carbon monoxide, phosphines and acetylenes, displacement of the arene takes place and known derivatives of Co₄(CO)₁₂ and Co₂(CO)₈ are formed. With phosphites, however, displacement of one carbon monoxide can be achieved, to give Co₄(CO)₈(arene)P(OR)₃. The same type of complexes can also be prepared by treatment of Co₄(CO)₁₁P(OR)₃ with arenes.     

Iridium-carbonyl clusters: VI. Mixed-metal clusters via metal-hydride coupling. Synthesis of CpMM′3(CO)11 (M = Mo,W; M′ = Co,Ir) and the crystal structure of CpMoIr3(CO)11

The reaction of CpM(CO)₃H (M = Mo, W), with IrCl(CO)₂(p-toluidine) leads to the species CpMIr₃(CO)₁₁; reaction of CpM(CO)₃H with Co₄(CO)₁₂ produces the known species CpMCo(CO)₁₁ in high yield. The newly-reported species CpMoIr₃(CO)₁₁ has been subjected to an X-ray structural analysis. It crystallizes in the centrosymmetric orthorhombic space group Pbca (No. 61) with a 12.2830(15), b 13.5113(18), c 24.9418(30) Å, V 4139.3(9) ų and Z = 8.Diffraction data were collected with a Syntex P2₁ automated diffractometer (Mo-K_α radiation, 2θ 4.0–45.0°) and the structure was refined to R 5.4% for all 2421 data (R 4.5% for those 2141 data above 3σ(¦F₀¦)).CpMoIr₃(CO)₁₁ is neither isomorphous nor isostructural with the known species CpWIr₃(CO)₁₁ or CpMoCo₃(CO)₁₁. It differs by possessing three bridging carbonyl ligands which encircle one MoIr₂ face of the tetrahedral MoIr₃ cluster. The structure is completed by a Cp ligand on Mo and eight terminal carbonyl ligands (one on the molybdenum atom, three on the unique iridium atom and two each on the iridium atoms associated with the MoIr₂(μ-CO)₃ moiety). The molecule has approximate C_s symmetry.     

Co2(CO)8-mediated and -catalyzed carbonylation of diaryl diselenides and ditellurides to seleno and telluro esters

Diaryl diselenides and ditellurides react with CO (5–100 atm) at 100–200°C in the presence of Co₂(CO)₈ to give the corresponding seleno and telluro esters in 21–96% yield. The carbonylation proceeds catalytically in CO₂(CO)₈ in the presence of triphenylphosphine. It was shown unambiguously that benzoylcobalt tetracarbonyl, which is one of possible intermediates, reacts with diphenyl diselenide or ditelluride to give phenyl selenobenzoate or tellurobenzoate, respectively.     

A new germanium tetracobalt carbonyl: GeCo4(CO)14

The room-temperature reaction of NaCo(CO)₄ with halogermanes, or Co₂(CO)₈ with GeH₄, gives GeCo₄(CO)₁₄ which is assigned a Ge[Co₂(CO)₇]₂ structure on infrared evidence. This new species eliminates one CO at 50°C to give (CO)₄CoGeCO₃(CO)₉ and adds further CO(CO)₄^- to give anionic [GeCo₆(CO)_n]^2-.     

Reactions of (η6-diphenylacetylene) chromiumtricarbonyl complexes with polynuclear carbonyls I. Synthesis of Cr(CO)3(η6-diphenylacetylene) complex and its reaction with Co2(CO)8. Crystal and molecular structure of Cr(CO)3(η6:η2-diphenylacetylene)Co2(CO)6

The reaction of Cr(CO)₃(NH₃)₃ with diphenylacetylene affords as a main product the complex with Cr(CO)₃ moiety bound to a phenyl ring of diphenylacetylene; Cr(CO)₃(η⁶-PhC₂Ph) (I). Complex I readily reacts with Co₂(CO)₈ yielding the mixed metal complex Cr(CO)₃(η⁶:η²-PhC₂Ph)Co₂(CO)₆ (II). The reaction proceeds with retention of the Cr(CO)₃ (η⁶-arene) structural unit, the Co₂(CO)₆ fragment being bound to the triple bond of diphenylacetylene in μ₂,η²-mode. The structure of II was determined by single crystal X-ray analysis. The complex crystallizes in space group P2₁/c with unit cell parameters a 8.666(3) Å, b 18.046(3) Å, c 15.155(6) Å. β 97.57(3)°, V 2349(2) ų, Z = 4, D_x = 1.70 g/cm³. The structure was solved by direct methods and refined by full-matrix least-squares technique to R and R_w values of 0.032 and 0.034, respectively, for 3655 observed reflections. The data obtained show that two structural units in II, Cr(CO)₃(η⁶-Ph-) and Co₂(CO)₆(μ₂,η²-CC), are distorted due to steric repulsion between these metal carbonyl moieties. The Cr(CO)₃ fragment is shifted from the centre of the phenyl ring and slightly tilted with respect to the phenyl ring plane. The Co₂C₂ tetrahedron in the Co₂(CO)₆(μ₂,η²-CC) moiety is distorted in such a way that two of the four Co_iC_j bonds are elongated.     

Syntheses of double- and triple-decker clusters of osmium and cobalt metals linked by cyclotetradeca-1,8-diyne ligands

Photoirradiation of Os₃(CO)₁₀(C₁₄H₂₀) (1) in n-hexane produces the double-decker cluster [Os₃(CO)₉(C₂₈H₄₀)] [Os₃(CO)₁₀] (7), which can also be prepared from the reaction of Os₃(CO)₉(C₂₈H₄₀) (2) and Os₃(CO)₁₀(NCMe)₂. Further reaction of 7 with Os₃(CO)₁₀(NCMe)₂ affords the triple-decker cluster [Os₃(CO)₉(C₂₈H₄₀)][Os₃(CO)₁₀]₂ (8). The bis(diyne) complex Os₃(CO)₈(C₁₄H₂₀)₂ (3) reacts with Os₃(CO)₁₀(NCMe)₂ sequentially to yield the double-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Os₃(CO)₁₀] (4) and the triple-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Os₃(CO)₁₀]₂ (5). Treatment of 3 with Co₂(CO)₈ at room temperature leads to the mixed-metal triple-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Co₂(CO)₆]₂ (6), while the reaction of 2 and Co₂(CO)₈ produces [Os₃(CO)₉(C₂₈H₄₀)][Co₂(CO)₆]₂ (9) and [Os₂(CO)₆(C₂₈H₄₀)][Co₂(CO)₆]₂ (10). Compound 10, which involves cluster degradation from Os₃ to Os₂, has been structurally characterized by an X-ray diffraction study.     

Synthesis and characterization of linked alkyne-bridging Co2C2 tetrahedral clusters and expansion reactions of (Co2(CO)6(μ-HCCCH2OOC))2R with Fe3(CO)12

Two new linked alkyne-bridging tetrahedral carbonyl clusters containing Co₂C₂ Co₂(CO)₆(μ-HCCCH₂OOC(CH₂)₃COOCH₂CCH-μ)Co₂(CO)₆, 1, and Co₂(CO)₆(μ-HCCCH₂OOC(CH₂)₈COOCH₂CCH-μ)Co₂(CO)₆, 2, have been prepared by reactions of two dipropargyl esters (HC≡CCH₂OOC)₂R (R = (CH₂)₃, (CH₂)₈) with Co₂(CO)₈. Expansion reactions of 1 and Co₂(CO)₆(μ-HCCCH₂OOCCOOCH₂CCH-μ)Co₂(CO)₆, 3, with Fe₃(CO)₁₂ give two new mixed-metal linked clusters Co₂(CO)₆(μ-HCCCH₂OOC(CH₂)₃COOCH₂CCH-μ,η⁴)Co₂Fe₂(CO)₁₂, 4, and Co₂(CO)₆(μ-HCCCH₂OOCCOOCH₂CCH-μ,η⁴)Co₂Fe₂(CO)₁₂, 5. The new clusters were characterized by elemental analysis, IR, ¹H-NMR and ESI-MS analysis.     

Multiple C−H Bond Activations in Corannulene by a Dirhenium Complex

The reaction of Re₂(CO)₈(μ-C₆H₅)(μ-H), 1 with corannulene (C₂₀H₁₀) yielded the product Re₂(CO)₈(μ-H)(μ-η²-1,2-C₂₀H₉), 2 (65 % yield) containing a Re₂ metalated corannulene ligand formed by loss of benzene from 1 and the activation of one of the CH bonds of the nonplanar corannulene molecule by an oxidative-addition to 1 . The corannulenyl ligand has adopted a bridging η²-σ+π coordination to the Re₂(CO)₈ grouping. Compound 2 reacts with a second equivalent of 1 to yield three isomeric doubly metalated corannulene products: Re₂(CO)₈(μ-H)(μ-η²-1,2-μ-η²-10,11-C₂₀H₈)Re₂(CO)₈(μ-H), 3 (35 % yield), Re₂(CO)₈(μ-H)(μ-η²-2,1-μ-η²-10,11-C₂₀H₈)Re₂(CO)₈(μ-H), 4 (12 % yield), and Re₂(CO)₈(μ-H)(μ-η²-1,2-μ-η²-11,10-C₂₀H₈)Re₂(CO)₈(μ-H), 5 (12 % yield), by a second CH activation on a second rim double bond on the corannulene molecule. The isomers differ by the relative orientations of the coordinated Re₂(CO)₈(μ-H) groupings. All new products were characterized structurally by single crystal X-ray diffraction analysis.