Examining the impact of ancillary ligand basicity on copper(I)–ethylene binding interactions: a DFT study

A theoretical investigation at the density functional theory level (B3LYP) has been conducted to elucidate the impact of ligand basicity on the binding interactions between ethylene and copper(I) ions in [Cu(η ²-C₂H₄)]⁺ and a series of [Cu(L)(η ²-C₂H₄)]⁺ complexes, where L = substituted 1,10-phenanthroline ligands. Molecular orbital analysis shows that binding in [Cu(η ²-C₂H₄)]⁺ primarily involves interaction between the filled ethylene π-bonding orbital and the empty Cu(4s) and Cu(4p) orbitals, with less interaction observed between the low energy Cu(3d) orbitals and the empty ethylene π*-orbital. The presence of electron-donating ligands in the [Cu(L)(η ²-C₂H₄)]⁺ complexes destabilizes the predominantly Cu(3d)-character filled frontier orbital of the [Cu(L)]⁺ fragment, promoting better overlap with the vacant ethylene π*-orbital and increasing Cu → ethylene π-backbonding. Moreover, the energy of the filled [Cu(L)]⁺ frontier orbital and mixing with the ethylene π*-orbital increase with increasing pK _a of the 1,10-phenanthroline ligand. Natural bond orbital analysis reveals an increase in Cu → ethylene electron donation with addition of ligands to [Cu(η ²-C₂H₄)]⁺ and an increase in backbonding with increasing ligand pK _a in the [Cu(L)(η ²-C₂H₄)]⁺ complexes. Energy decomposition analysis (ALMO-EDA) calculations show that, while Cu → ethylene charge transfer (CT) increases with more basic ligands, ethylene → Cu CT and non-CT frozen density and polarization effects become less favorable, yielding little change in copper(I)–ethylene binding energy with ligand pK _a. ALMO-EDA calculations on related [Cu(L)(NCCH₃)]⁺ complexes and calculated free energy changes for the displacement of acetonitrile by ethylene reveal a direct correlation between increasing ligand pK _a and the favorability of ethylene binding, consistent with experimental observations.     

Synthesis of asymmetrical bis(arene) iron complexes

Visible light irradiation of the [(η-C₆H₇)Fe(η-C₆H₆)]⁺ cation (1) in CH₂Cl₂ in the presence of alkyl-substituted benzenes results in arene exchange forming the [(η⁵-C₆H₇)Fe(η-C₆R₆)]⁺ cations (2a–d: C₆R₆ is toluene, p-xylene, mesitylene, and durene). The mixed bis(arene) [(η-C₆H₆)Fe(η-C₆R₆)]²⁺ iron complexes (3a–d) were synthesized by hydride ion abstraction from 2a–d by [Ph₃C]⁺. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1864–1865, September, 2007.     

Sandwich complexes of Si, Ge, Sn, and Pb with cyclopentadienyl type derivatives of corannulene and fullerene C60: stability estimates and molecular and electronic structure prediction by the MNDO/PM3 method

The ability of cyclopentadienyl type derivatives of corannulene C₂₀H₁₀ and fullereneI _h -C₆₀ to form η⁵-π-complexes and the problem of their existence is discussed. MNDO/PM3 calculations of half-sandwich complexes η⁵-π-MC₂₀H₁₅, η⁵-π-MC₂₀H ₁₅ ⁺ , η⁵-π-MC₆₀H₅, η⁵-π-MC₆₀H₅ and sandwich complexes 2η⁵-π-M(C₂₀H₁₅)₂, 2η⁵-π-M(C₂₀H₁₅)₂, 2η⁵-π-M(C₆₀H₅)₂ (M=Si, Ge, Sn, Pb) were performed. For all systems studied, local minima were found on corresponding potential energy surfaces and the heats of formation, geometric parameters, and distributions of effective atomic charges were calculated. Sandwich complexes are most likely to exist with M=Si and Ge. The energy and geometric characteristics of η⁵-π-complexes of corannulene were compared with those of η⁵-π-complexes of fullereneI _h -C₆₀. It was concluded that the results of quantum-chemical calculations of sandwich type corannulene derivatives can be used for simulation of the geometry and electronic structure of analogous complexes of fullereneI _h -C₆₀. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1649–1656, September, 1999.     

An electrochemical investigation on the reduction path of the arene complexes [CpM(arene)]2+ and [(η-9-SMe2-7,8-C2B9H10)M(arene)]2+ (M=Rh, Ir)

The reduction behavior of the isoelectronic complexes [CpM^III(η⁶-C₆R₆)]²⁺ (M=Rh, Ir; R=H, Me) and [(η-9-SMe₂-7,8-C₂B₉H₁₀)M^III(η⁶-C₆R₆)]²⁺ (M=Rh, Ir; C₆R₆ = C₆H₆, C₆H₅OMe, C₆H₃Me₃) has been studied by cyclic voltammetry and controlled potential coulometry in acetonitrile and propylene carbonate at 253 and 298 K, respectively. The extent of chemical reversibility of the pertinent sequences Rh(III)/Rh(II)/Rh(I) and Ir(III)/Ir(I) is highly dependent on both the nature of the solvent and the intrinsic electronic properties of the arene substituents. The arene η⁶ coordination makes the derivatives in their lower oxidation states notably short lived, even if, in some cases, the use of propylene carbonate improves their stability or causes the increase in their lifetimes before changing the arene coordination from η⁶ to η⁴. Cations [(η-9-SMe₂-7,8-C₂B₉H₁₀)M(η⁶-C₆R₆)]²⁺ were obtained by the bromide abstraction from [(η-9-SMe₂-7,8-C₂B₉H₁₀)MBr₂]₂ with Ag⁺ in the presence of benzene and its derivatives. The structure of [(η-9-SMe₂-7,8-C₂B₉H₁₀)Ir(η⁶-C₆H₅OMe)](BF₄)₂ was determined by X-ray diffraction.     

Photochemical substitution of benzene in the iron cyclohexadienyl complex [(η<Superscript>5</Superscript>-C<Subscript>6</Subscript>H<Subscript>7</Subscript>)Fe(η-C<Subscript>6</Subscript>H<Subscript>6</Subscript>)]<Superscript>+</Superscript>

The visible light irradiation of the [(η⁵-C₆H₇)Fe(η-C₆H₆)]⁺ cation (1) in acetonitrile resulted in the substitution of the benzene ligand to form the labile acetonitrile species [(η⁵-C₆H₇)Fe(MeCN)₃]⁺ (2). The reaction of 1 with Bu^tNC in MeCN produced the stable isonitrile complex [(η⁵-C₆H₇)Fe(Bu^tNC)₃]⁺ (3). The photochemical reaction of cation 1 with pentaphosphaferrocene Cp*Fe(η-cyclo-P₅) afforded the triple-decker cation with the bridging pentaphospholyl ligand, [(η⁵-C₆H₇)Fe(μ-η:η-cyclo-P₅)FeCp*]⁺ (4). The latter complex was also synthesized by the reaction of cation 2 with Cp*Fe(η-cyclo-P₅). The structure of the complex [3]PF₆ was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2088–2091, November, 2007.     

Ab initio MO LCAO SCF simulation of molecular and electronic structure of η5-π-C60H5XCp (X=Fe, Si) complexes

The problem of existence of η⁵-π-complexes of unsubstituted fullereneI _h -C₆₀ and its cyclopentadienyl type derivative C₆₀H₅ ^. is discussed.Ab initio MO LCAO SCF calculations of hypothetical sandwich systems η⁵-π-C₆₀H₅XCp (X=Fe (1a), Si (1b)), the cationic complex C₆₀FeCp⁺ of unsubstituted C₆₀, and the C₆₀H₅ ^. radical were performed in the STO-3G and 3-21G basis sets. In the1a, 1b, and C₆₀H₅ ^. systems, hydrogen atoms are attached to carbon atoms of fullerenei _h -C₆₀ at α-positions relative to the same pentagonal face (pent ^*). In η⁵-complexes, XCp species are also coordinated to this face. According to calculations in the 3-21G basis set, the Fe-pent ^* bond energy in complex1a is much higher than those of similar bonds in1b and in the η⁵-π-C₆₀FECp⁺ cation (117 kcal mol⁻¹ vs. 37 and 64 kcal mol⁻¹, respectively) and is 7 kcal mol⁻¹ higher than the Fe−Cp bond energy in the classical sandwich system FeCp₂. The Fe…C _pent* and Fe…C_Cp distances in complex1a are slightly shorter than the Fe…C distance in the ferrocene molecule. The spin populations in the C₆₀H₅ ^. radical are almost completely localized on the atoms of thepent ^* face, which must favor the formation of η⁵-π-complexes of this radical. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1657–1662, September, 1999.     

Dynamic effect on the structure of X-ray photoelectron spectra of lanthanide fluorides and oxides

Dynamic effect on the fine structure of X-ray photoelectron spectra of lanthanide oxides and fluorides is discussed. The Ln4p electron spectra are considerably complicated by the interaction between the configurations of themain one-hole and additional two-hole final states of 4p⁵4d⁵⁴fⁿ ↔ 4p⁶4d⁸fⁿ⁺¹ type. The effect of the nature of atoms in the nearest environment of lanthanide ions on the fine structure parameters is evaluated. Translated fromZhurnal Struktumoi Khimii, Vol. 39, No. 6, pp. 1059–1066, November–December, 1998.     

Synthesis,Characterization and Crystal Structures of New Difurylphosphido-bridged Dinuclear Ruthenium Carbonyl Complexes Derived from Ferrocenylacetylene Ligands

The difurylphosphido-bridged dinuclear complex [Ru₂(CO)₆(μ-PFu₂)(μ-η¹,η²-Fu)] (Fu = 2-furyl) 1 readily reacts with two equivalents of each of the terminal alkynes HC≡CR (R = Fc, p-C₆H₄Fc, p-C₆H₄NO₂, Fc = Fe(η⁵-C₅H₅)(η⁵-C₅H₄)) by an interesting head-to-tail ynyl coupling with a furan group to form a series of phosphido-bridged diruthenium compounds containing a novel furyl-substituted C₄ hydrocarbyl chain of stoichiometry [Ru₂(CO)₄(μ-PFu₂){μ-η¹,η¹,η²,η³-RCC(H)C(R)C(H)Fu}] (R = Fc 2, p-C₆H₄Fc 3, p-C₆H₄NO₂ 4) in moderate to good yields. Reaction of 1 with an equimolar amount of HC≡CFc and HC≡C(p-C₆H₄NO₂) afforded a pair of isomers of [Ru₂(CO)₄(μ-PFu₂){μ-η¹,η¹,η²,η³-R¹CC(H)C(R²)C(H)Fu}] (R¹ = Fc, R² = p-C₆H₄NO₂ 5a; R¹ = p-C₆H₄NO₂, R² = Fc 5b) together with a small mixture of 4. X-ray crystal structures of 2, 3, 5a and 5b are reported. All of these new alkyne-derived dinuclear complexes are electron precise with 34 cluster valence electrons in which the μ-η¹,η²-furyl ligand acts as a three-electron donor and the μ-phosphido Ru₂ framework is retained in the products upon alkyne coupling reactions. The resulting organic fragment of each complex is coordinated to the Ru atoms via a π, a π-allyl and two σ bonds, and donates seven electrons to the metal core. Dedicated to the memory of Professor F. Albert Cotton.     

Iron and ruthenium triple-decker complexes with a central pentaphospholyl ligand

Thirty-electron triple-decker complexes with a central pentaphospholyl ligand [(η-C₅Me₅)Fe(μ-η:η-P₅)M(η-C₅R₅)]BF₄ (M=Fe, R=Me or M=Ru, R=H, Me) were synthesized by a stacking reaction of cationic 12-electron fragments [(η-C₅R₅)M]⁺ with (η-C₅Me₅)Fe(η-P₅). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1625–1626, August, 1998.     

Synthesis of triple-decker iron and cobalt complexes with a central tetramethylphospholyl ligand

30-Electron triple-decker complexes [(η-C₅H₅)Fe(μ-η:η-C₄Me₄P)Fe(η-C₅Me₅)]PF₆ and [(η-C₄Me₄)Co(μ-η:η-C₄Me₄P)Fe(η-C₅Me₅)]PF₆ with a central tetramethylphospholyl ligand were synthesized by stacking reactions of cationic fragments [(η-C₅H₅)Fe]⁺ and [(η-C₄Me₄)Co]⁺ with nonamethylphosphaferrocene (η-C₄Me₄P)Fe(η-C₅Me₅). Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1647–1649, September, 2000.     

Cyclopentadienyl type η5-π-complexes of C60 fullerene derivatives with indium and thallium: simulation of molecular and electronic structure by the MNDO/PM3 methodof C60 fullerene derivatives with indium and thallium: simulation of molecular and electronic structure by the MNDO/PM3 method

The results of MNDO/PM3 calculations of η⁵-π-C₆₀R₅M complexes (R=H and Ph; M=Tl and In) are reported. Local energy minima and geometric parameters as well as the heats of formation and ionization potentials were determined for all systems in question. The nature of chemical M—pent bonding (pent is the pentagonal face) is discussed. The results of calculations are compared with experimental data that confirm our predictions about the possibility of existence of stable cyclopentadienyl type η⁵-π-complexes of C₆₀ fullerence derivatives. The stability of the C₆₀In₁₂ complex with theI _h symmetry, in which the In atoms are coordinated to each of 12 pentagonal faces of C₆₀ fullerene, was estimated. The energy of the In—pent bond (62.4 kcal mol⁻¹) is close to that in C₆₀H₅In (64.5 kcal mol⁻¹). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1935–1940, November, 1997.     

Why betaine crystallizes in high local Cs symmetry. An ab initio MO and DFT study of anhydrous betaine and betaine monohydrate

A theoretical study of the structure, charge distribution, rotational barrier and fundamental vibrations of anhydrous betaine (CH₃)₃NCH₂COO (trimethylglycine) was carried out and compared with available experimental data. Calculations were carried out at HF, MP2 and B3LYP levels using a 6-31+G(d,p) basis set. The calculated rotational barrier of the betaine carboxylic group is 40.5 kJ/mol at the MP4(SDQ)/6-311G(d,p)//HF/6-31+G(d,p) level of theory. The rotation of the carboxylic group changes the molecule from a highly symmetric (C _s ) conformation into a twisted conformation resulting in shortening of the molecule by about 50 pm. Natural population analysis (NPA) indicates intramolecular interaction between the carboxylic oxygen and the nearest methyl hydrogens resulting in internal hydrogen bonding. MP4(SDQ)/6-311G(d,p) single-point NPA calculations on a betaine monohydrate model taken from the X-ray geometry show an expected weakening in the internal hydrogen bond. Calculations explain why betaine preferentially crystallizes in high local C _s symmetry. Received: 24 March 1998 / Accepted: 3 September 1998 / Published online: 7 December 1998     

Benzene complex [(η-9-SMe2-7,8-C2B9H10)Fe(η-C6H6)]+ as a synthon for the cationic ferracarborane moiety

The photochemical reaction of [(η⁵-C₆H₇)Fe(η-C₆H₆)]⁺ (1) with the [(η-9-SMe₂-7,8-C₂B₉H₁₀)]⁻ anion followed by the treatment of the resulting ferracarborane (η-9-SMe₂-7,8-C₂B₉H₁₀)Fe(η⁵-C₆H₇) (2) with hydrochloric acid afforded the benzene complex [(η-9-SMe₂-7,8-C₂B₉H₁₀)Fe(η-C₆H₆)]⁺ (3). The reaction of cation 3 with Bu^tNC produced the isonitrile complex [(η-9-SMe₂-7,8-C₂B₉H₁₀)Fe(^tBuNC)₃]⁺ (4). The structure of the complex [4]PF₆ was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2046–2048, October, 2007.     

Theoretical study of the valence π → π* excited states of polyacenes: anthracene and naphthacene

The valence π → π ^* excited states of anthracene and naphthacene are studied with multireference perturbation theory with complete active space self-consistent field reference functions. The predicted spectra provide a consistent assignment of all one- and two-photon spectra and T-T spectra of low-lying valence π → π ^* excited states of anthracene and naphthacene. The present theory predicts the valence π → π ^* excitation energies with an accuracy of 0.15 eV for anthracene and of 0.25 eV or better for naphthacene. The excited states of anthracene and naphthacene are compared with those of benzene and naphthalene studied previously. The present calculations predict that, going from anthracene to naphthacene, there is a symmetry reversal of the two lowest singlet state transitions, but not for the triplet, just as indicated by the experimental data. Some general trends of polyacene excited states are discussed based on the calculated results for benzene to naphthacene. Conclusive results obtained for anthracene and naphthacene can be used as a model for understanding the excited states of larger polyacenes. Received: 22 April 1998 / Accepted: 6 July 1998 / Published online: 28 September 1998     

Photochemical arene exchange in the ferracarborane complex [1-(η-C6H6)-12-ButNH-1,2,4,12-FeC3B8H10]+

The benzene complex [1-(η-C₆H₆)-12-Bu^tNH-1,2,4,12-FeC₃B₈H₁₀]⁺ (3a) was synthesized by the photochemical reaction of [(η⁵-C₆H₇)Fe(η-C₆H₆)]⁺ (1) with the anion [7-Bu^tNH-7,8,9-C₃B₈H₁₀]⁻ followed by the treatment of ferracarborane 1-(η⁵-C₆H₇)-12-Bu^tNH-1,2,4,12-FeC₃B₈H₁₀ (2) with hydrochloric acid. The benzene ligand in cation 3a is replaced by alkyl-substituted benzenes under visible light irradiation in CH₂Cl₂ to form [1-(η-C₆R₆)-12-Bu^tNH-1,2,4,12-FeC₃B₈H₁₀]⁺ (3b–e; C₆R₆ is toluene (b), mesitylene (c), hexamethylbenzene (d), or anisole (e)). The structure of [3c]PF₆ was established by X-ray diffraction.     

Photochemical replacement of benzene in the tetramethylcyclopentadienyl complex of iron, [η-C<Subscript>5</Subscript>Me<Subscript>4</Subscript>H)Fe(η-C<Subscript>6</Subscript>H<Subscript>6</Subscript>)]<Superscript>+</Superscript>

Irradiation of the cation [η-C₅Me₄H)Fe(η-C₆H₆)]⁺+ (1) and Bu^tNC with visible light in acetonitrile results in the displacement of the benzene ligand, giving [(η-C₅Me₄H)Fe(Bu^tNC)₃]+ (2). Reactions of complex 1 with P(OR)₃ and dppe in M_eCN yield the complexes [(η-C₅Me₄H)-Fe(M_eCN)P(OR)_{3 2}]+ (R = Me (3) and Et (4)) and [(η-C₅Me₄H)Fe(MeCN)(dppe)]+ (5) containing two Fe—P bonds. The same reactions in CH₂Cl₂ give the tris(phosphite) complexes [(η-C₅Me₄H)FeP(OR)_{3 3}]+ (6, 7). A photochemical reaction of complex 1 with pentaphos-phaferrocene Cp*Fe(η-cyclo-P₅) yields the triple-decker cation [(η-C₅Me₄H)Fe(μ-η:η-cyclo-P₅)FeCp*]+ (8) with a bridging pentaphospholyl ligand. Structures [2]PF₆ and [3]PF₆ were identified by X-ray diffraction.     

Simulation of molecular and electronic structure of η5-π-complexes of fullereneI h -C 60 with half-sandwich XCp species (X=Si, Ge, Sn)

The molecular and electronic structure of hypothetical complexes of unsubstituted fullerene C₆₀ withI _h symmetry and its cyclopentadienyl type derivatives were simulated by the MNDO/PM3 method taking the C₆₀(XC[) _n molecules (n=1, 2, 10, 12; X=Si, Ge, Sn) and η⁵-C₆₀H₅XCp (X=Ge, Sn), respectively, as example. The complexes 12η⁵-πC₆₀(XCp)₁₂ and η⁵-πC₆₀XCp withI _h andC _5v symmetry, respectively, were found to be the most stable compounds. The energies of the X−C₆₀ bonds in these complexes are close to those of X−Cp bonds in bis(cyclopentadienyl) complexes XCp₂ and are substantially higher than the energies of similar bonds in complexes of unsubstituted fullerene η¹-πC₆₀(XCp)⁻ and η⁵-πC₆₀(XCp)⁺. Geometric parameters and spin densities in radicals C₆₀XCp and biradicals C₆₀(XCp)₂ and C₆₀H₁₀ were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2155–2165, November, 1998.     

Ionic bonding of lanthanides,as influenced by d‐ and f‐atomic orbitals,by core–shells and by relativity

Lanthanide trihalide molecules LnX₃ (X = F, Cl, Br, I) were quantum chemically investigated, in particular detail for Ln = Lu (lutetium). We applied density functional theory (DFT) at the nonrelativistic and scalar and SO‐coupled relativistic levels, and also the ab initio coupled cluster approach. The chemically active electron shells of the lanthanide atoms comprise the 5d and 6s (and 6p) valence atomic orbitals (AO) and also the filled inner 4f semivalence and outer 5p semicore shells. Four different frozen‐core approximations for Lu were compared: the (1s²–4d¹⁰) [Pd] medium core, the [Pd+5s²5p⁶ = Xe] and [Pd+4f¹⁴] large cores, and the [Pd+4f¹⁴+5s²5p⁶] very large core. The errors of Lu? X bonding are more serious on freezing the 5p⁶ shell than the 4f¹⁴ shell, more serious upon core‐freezing than on the effective‐core‐potential approximation. The Ln? X distances correlate linearly with the AO radii of the ionic outer shells, Ln³⁺‐5p⁶ and X^?‐np⁶, characteristic for dominantly ionic Ln³⁺‐X^? binding. The heavier halogen atoms also bind covalently with the Ln‐5d shell. Scalar relativistic effects contract and destabilize the Lu? X bonds, spin orbit coupling hardly affects the geometries but the bond energies, owing to SO effects in the free atoms. The relativistic changes of bond energy BE, bond length R_e, bond force k, and bond stretching frequency v_s do not follow the simple rules of Badger and Gordy (R_e～BE～k～v_s). The so‐called degeneracy‐driven covalence, meaning strong mixing of accidentally near‐degenerate, nearly nonoverlapping AOs without BE contribution is critically discussed. © 2015 Wiley Periodicals, Inc.     

Oxidation of (η5-6-exo-cyclopentadienylcyclohexadienyl)- (η5-cyclopentadienyl) iron by trityl hexafluorophosphateby trityl hexafluorophosphate

Oxidation of the cyclohexadienyl complex Fe(η⁵-C₅H₅)(1-5-7⁵-6-exo-C₅H₅-C₆H₆) (2) by (Ph₃C)PF₆ (CH₂Cl₂, from −30 to +20 °C) occurs as two concurrent processes: elimination of an H atom from the cyclohexadienyl ligand and replacement of an H atom in the cyclopentadienyl ring by a CPh₃ fragment. A mixture of cationic complexes [Fe(η⁵-C₅H₅) (η⁶-Ph-C₅H₅]⁺ (1⁺) and [Fe(η⁵-C₅H₄CPh₃) (η⁶-Ph-C₅H₅]⁺ (4⁺) (4 ⁺) with PF₆ ⁻ anions is obtained. Deprotonation of the mixture of 1⁺ and 4⁺ complexes under the action of Bu ^t OK inm-xylene followed by boiling of the reaction mixture gives phenylferrocene (7) as the product of η⁶:η⁶ haptotropic rearrangement. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, NO. 5, pp. 1045–1047, May, 1997.     

Synthesis, spectral characteristics, and crystal structure of the hexanuclear complex MeSi[η1,η5-C5H4(CO)2Fe(η1,η5-C5H5)Mn(CO)3]3

The reaction of MeSiCl₃ with 3 equivalents of LiC₅H₄(CO)₂Fe(η¹,η⁵-C₅H₄)Mn(CO)₃ afforded the hexanuclear complex MeSi[η¹,η⁵-C₅H₄(CO)₂Fe(η¹,η⁵-C₅H₅)Mn(CO)₃]3. The structure of the resulting complex was established by¹H and¹³C NMR and IR spectroscopy and by X-ray diffraction analysis. Dedicated to the memory of Academician M. I. Kabachnik on his 90th birthday. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2056–2061, October, 1998.