Stacking reactions of the borole complex Cp*Rh(η5-C4H4BPh) with the dicationic fragments [Cp*M]2+ (M = Rh or Ir)

The reaction of the (borole)rhodium iodide complex [(η-C₄H₄BPh)RhI]₄ with Cp^*Li afforded the sandwich compound Cp^*Rh(η-C₄H₄BPh) (4). The reactions of compound 4 with the solvated complexes [Cp^*M(MeNO₂)₃]²⁺(BF ₄ ⁻ )₂ gave triple-decker cationic complexes with the central borole ligand [Cp^*Rh(η-η⁵:η⁵-C₄H₄BPh)MCp^*]²⁺(BF ₄ ⁻ )₂ (M = Rh (5) or Ir (7)). The structure of complex 4 was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1525–1527, September, 2006.     

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.     

1,2,3,4,7-Pentamethylindenyl complex [(η5-C9H2Me5)RhI2]2 as a synthon for the [(η5-C9H2Me5)Rh]2+ fragment

The reaction of the iodide complex [(η⁵-C₉H₂Me₅)RhI₂]₂ (1) or the acetonitrile complex [(η⁵-C₉H₂Me₅)Rh(MeCN)₃]²⁺ with Tl[Tl(η-7,8-C₂B₉H₁₁)] afforded rhodacarborane (η⁵-C₉H₂Me₅)Rh(7,8-C₂B₉H₁₁) (2). The cationic triple-decker complex with the bridging boratabenzene ligand [Cp*Fe(μ-η:η-C₅H₃Me₂BMe)Rh(η⁵-C₉H₂Me₅)]²⁺ (3) was synthesized by the reaction of the nitromethane solvate [(η⁵-C₉H₂Me₅)Rh(MeNO₂)₃]²⁺ with the sandwich compound Cp*Fe(η-C₅H₃Me₂BMe). The structure of 2 was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1623–1625, August, 2008.     

The Isolation of a Large Cyclopentadienylcobaltsulfide Cluster. The Synthesis and Crystal Structure of Octahedral closo-(η5-C5H5Co)5S

The title cluster, which was obtained serendipitously when (η⁵-C₅H₅)Co(PPh₃)₂ was added to a (η⁵-C₅H₅)Co metallacyclobutene containing a sulfone group, is the largest cluster known, formed primarily with (η⁵-C₅H₅)Co vertices. The closo-(η⁵-C₅H₅Co)₅S is a closed-shell, octahedral cluster which forms black, monoclinic crystals from methanol.     

Synthesis and characteristics of novel pentanuclear complexes [(OC)3Mn(η1,η5-C5H4)Fe(CO)2(η1,η5-C5H4CO2)]2M(η5-C5H5)2 (M=Ti, Zr)

The reaction of Cp₂MCl₂ complexes (M=Ti and Zr) with 2 equiv. of (OC)₃Mn(η¹,η⁵-C₅H₄)Fe(CO)₂(η⁵-C₅H₄COONa) results in the formation of the pentanuclear complexes (OC)₃Mn(η¹,η⁵-C₅H₄)Fe(CO)₂(η⁵-C₅H₄CO₂)]₂M(η⁵-C₅H₅)₂, which are characterized by IR and¹H NMR spectroscopy and cyclic voltammetry. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1055–1058, May, 1997.     

30-Electron cationic iron- and cobalt-containing triple-decker complexes with a central cyclopentadienyl ligand. The first synthesis of the parent triple-decker iron complex with cyclopentadienyl ligands, [(η-C5H5)Fe(μ-η:η-C5H5)Fe(η-C5H5)]PF6

The parent 30-electron triple-decker iron complex with cyclopentadienyl ligands, [(η-C₅H₅)Fe(μ-η:η-C₅H₅)Fe(η-C₅H₅)]PF₆ (1), was prepared for the first time by visible-light irradiation of ferrocene and [(η-C₅H₅)Fe(η-C₆H₆)]PF₆ in CH₂Cl₂ at 0 °C. An analogous reaction performed with the use of (η-C₅H₅)Co(η-C₄Me₄) (2) instead of ferrocene afforded the thermally labile 30-electron cationic iron-cobalt triple-decker complex [(η-C₅H₅)Fe(μ-η:η-C₅H₅)Co(η-C₄Me₄)]PF₆. The latter reacted with compound 2 at 20 °C to form the symmetrical 30-electron cationic dicobalt triple-decker complex [(η-C₄Me₄)Co(μ-η:η-C₅H₅)Co(η-C₄Me₄)] PF₆. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 7, pp. 1364–1367, July, 1999.     

Synthesis of the cyclooctadiene and cyclooctenediyl cobalt complexes. Structures of [(η2,η2-cyclooctadiene)Co(η-1,2,4,5-C6H2Me4)]BF4 and [(η1,η3-cyclooctenediyl)Co(η-9-SMe2-7,8-C2B9H10)

Cobaltacarboranes (η¹, η³-cyclooctenediyl)Co(Carb) (Carb = η-9-SMe₂-7,8-C₂B₉H₁₀, η-1-tBuHN-1,7,9-C₃B₈H₁₀) were synthesized by the reaction of the carborane anions [Carb]⁻ with the acetonitrile complex [(η¹, η³-cyclooctenediyl)Co(MeCN)₃]⁺ generated in situ upon the dissolution of [(η¹, η³-cyclooctenediyl)Co(η-1,4-C₆H₄Me₂)]⁺ in MeCN. The structures of (η¹,η³-cyclooctenediyl)Co(η-9-SMe₂-7,8-C₂B₉H₁₀ and [(η²,η²-cyclooctadiene)Co((η-1,2,4,5-C₆H₂Me₄)]BF₄ were determined by X-ray diffraction analysis.     

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.     

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.     

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.     

Synthesis and structures of fulvene-bridged diruthenium complexes

Three diruthenium carbonyl complexes, namely (η ³:η ⁵-C₅H₄C(CH₂)₂)Ru₂(CO)₅ (1), (η ³:η ⁵-C₅H₄C(CHCH₂)(C₂H₅))Ru₂(CO)₅ (2), and (η ¹:η ⁵-C₅H₄C₅H₈)Ru₂(CO)₆ (3), were obtained from the reactions of C₅H₄C(Me)₂, C₅H₄C(Et)₂, and C₅H₄C(CH₂)₄, respectively, with Ru₃(CO)₁₂ in refluxing xylene. The complexes were characterized by elemental analysis, IR and ¹H NMR spectra. Single-crystal X-ray diffraction analysis for complexes 1 and 2 revealed that the fulvene ligands bridge two ruthenium atoms in η ³:η ⁵ fashion.     

Gold(I) complexes containing ionic phosphine ligands with a cobaltocenium backbone

The reaction of [(η⁵-R₂PC₅H₄)₂Co][PF₆] with (Me₂S)AuCl (1:2) resulted in {[(η⁵-R₂PC₅H₄)₂Co](AuCl)₂}[PF₆] (R = Ph, Cy, or ⁱ Pr). With a 1:1 ratio of [(η⁵-R₂PC₅H₄)Co(η⁵-C₅H₅)][PF₆] to (Me₂S)AuCl, yellow crystalline {[(η⁵-R₂PC₅H₄)Co(η⁵-C₅H₅)](AuCl)}[PF₆] was produced. The reaction of {[(η⁵-Cy₂PC₅H₄)Co(η⁵-C₅H₅)](AuCl)}[PF₆] with phenyl acetylene gave {[(η⁵-Cy₂PC₅H₄)Co(η⁵-C₅H₅)][Au(C≡C–Ph)]}[PF₆], while the reaction of {[(η⁵-Cy₂PC₅H₄)₂Co](AuCl)₂}[PF₆] with phenyl acetylene produced the unusual ionic complex {[(η⁵-Cy₂PC₅H₄)₂Co][Au(C≡C–Ph)]₂}[Au(C≡C–Ph)₂]. The structure of this complex has been characterized by X-ray crystallography, and a possible pathway for its formation is suggested. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

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.     

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.     

1,3-Diphenylindenyl zirconium complexes. Synthesis,structure, and reduction reactions

New zirconium sandwich complexes (η⁵-C₉H₅Ph₂)₂ZrCl₂ (1) and (η⁵-C₉H₅Ph₂)-(η⁵-C₅(CH₃)₅)ZrCl₂ (2) were synthesized and characterized. The molecular structures of complexes 1 and 2 were established by X-ray diffraction. The reduction of 1 and 2 does not stop at the formation of the Zr^II derivatives with the η⁹-coordinated indenyl ligand; instead the reaction results in the destruction of the metallocene structure. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1626–1629, August, 2008.     

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 of the first unsymmetrical 34-electron cationic cobalt-nickel triple-decker complex with a central cyclopentadienyl ligand [(η-C6Me6)Co(μ-η:η-C5H5)Ni(η-C5H5)]PF6

The first unsymmetrical 34-electron cationic cobalt-nickel triple-decker complex with a central cyclopentadienyl ligand [(η-C₆Me₆)Co(μ-η:η-C₅H₅)Ni(η-C₅)PF₆ was prepared by the reaction of [(η-C₆Me₆)₂Co]PF₆ with nickelocene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 798–799, April, 1999.     

Synthesis and Characterizations of Ferrocenyl Carbonyl Chromium and Cobalt Clusters

Two novel bimetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅)–C≡C–C₆H₄–Fc] (Fc = C₅H₅FeC₅H₄] (1) and [Cr(CO)₃(η ⁶-C₆H₅)–C ≡ C–Fc–C(CH₃)₂–Fc] (3), were synthesized by the Sonogashira coupling reaction. By using of (1) and (3) as ligands to react with Co₂(CO)₈, two others novel polymetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}–C₆H₄–Fc] (2) and [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}Fc–C(CH₃)₂–Fc] (4) were obtained. Four carbonyl complexes were characterized by elemental analysis, FT-IR, NMR and MS. The molecular structures of complexes (1), (2) and (4) were determined by single crystal X-ray diffraction. The interactions among the ferrocenyl, Cr(CO)₃ and Co₂(CO)₆-η ²-μ ²-C≡C– units were investigated by cyclic voltammetry.     

(η5-C5H5)2TiCl2- hydroalumination of α-olefins with Et3Alhydroalumination of α-olefins with Et3Al

A preparative method for the synthesis of (alkyl)diethylalanes from α-olefins and Et₃Al catalyzed by Cp₂TiCl₂ (Cp=η⁵-C₅H₅)is proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 712–715, April, 1998.     

π-complexes of monoanionic carborane ligand [9-(Me2S)-7,8-C2B9H10]− with [η-C5R5Fe]+ (R=H, Me) and [η-C4Me4Co]+ cationic fragments

Compounds (η-C₅R₅)Fe[η-9-(Me₂S)-7,8-C₂B₉H₁₀] (R=H, Me) and (η-C₄Me₄)Co[η-9-(Me₂S)-7,8-C₂B₉H₁₀] were synthesized by the reactions of Na[9-(Me₂S)-7,8-C₂B₉H₁₀] with complexes [(η-C₅H₅)Fe(MeCN)₃]PF₆, [(η-C₅Me₅)Fe(MeCN)₃]BF₄, and [(η-C₄Me₄)Co(MeCN)₃]PF₆, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 177–179, January, 1999.