Molecular structure of ansa-compound (η5-C5H4)CMe2(η5-C9H6)TiCl2

The structure of a new ansa compound, (⁵-C₅H₄)CMe₂(⁵-C₉H₆)TiCl₂ (1), was studied by X-ray analysis:a = 15.00(1),b =15.500(5),c = 13.032(4) Å, = 92.66°(4),V = 3025.1(1) ų, space groupP2₁/.,R = 0.038. The distorted tetrahedral coordination sphere of the Ti atom is formed by two Cl atoms and two -ligands. It was proposed that the angle () between theC-M direction and the line normal to M-Cp can be considered as one of the geometric parameters characteristic of the structure-properties correlation.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 1995.     

Comparison of the Bonding of Benzene and C60 to a Metal Cluster: Ru3(CO)9(μ3-η2,η 2,η2-C6H6) and Ru3(CO)9(μ3-η2,η2,η2-C60)

The electron distributions and bonding in Ru₃(CO)₉( ³- ², ², ²-C₆H₆) and Ru₃(CO)₉( ³- ², ², ²-C₆₀) are examined via electronic structure calculations in order to compare the nature of ligation of benzene and buckminsterfullerene to the common Ru₃(CO)₉ inorganic cluster. A fragment orbital approach, which is aided by the relatively high symmetry that these molecules possess, reveals important features of the electronic structures of these two systems. Reported crystal structures show that both benzene and C₆₀ are geometrically distorted when bound to the metal cluster fragment, and our ab initio calculations indicate that the energies of these distortions are similar. The experimental Ru–C_fullerene bond lengths are shorter than the corresponding Ru–C_benzene distances and the Ru–Ru bond lengths are longer in the fullerene-bound cluster than for the benzene-ligated cluster. Also, the carbonyl stretching frequencies are slightly higher for Ru₃(CO)₉( ³- ², ², ²-C₆₀) than for Ru₃(CO)₉( ³- ², ², ²-C₆H₆). As a whole, these observations suggest that electron density is being pulled away from the metal centers and CO ligands to form stronger Ru–C_fullerene than Ru–C_benzene bonds. Fenske-Hall molecular orbital calculations show that an important interaction is donation of electron density in the metal–metal bonds to empty orbitals of C₆₀ and C₆H₆. Bonds to the metal cluster that result from this interaction are the second highest occupied orbitals of both systems. A larger amount of density is donated to C₆₀ than to C₆H₆, thus accounting for the longer metal–metal bonds in the fullerene-bound cluster. The principal metal–arene bonding modes are the same in both systems, but the more band-like electronic structure of the fullerene (i.e., the greater number density of donor and acceptor orbitals in a given energy region) as compared to C₆H₆ permits a greater degree of electron flow and stronger bonding between the Ru₃(CO)₉ and C₆₀ fragments. Of significance to the reduction chemistry of M₃(CO)₉( ³- ², ², ²-C₆₀) molecules, the HOMO is largely localized on the metal–carbonyl fragment and the LUMO is largely localized on the C₆₀ portion of the molecule. The localized C₆₀ character of the LUMO is consistent with the similarity of the first two reductions of this class of molecules to the first two reductions of free C₆₀. The set of orbitals above the LUMO shows partial delocalization (in an antibonding sense) to the metal fragment, thus accounting for the relative ease of the third reduction of this class of molecules compared to the third reduction of free C₆₀.     

Five- and six-membered palladacycles derived from [(η5-C5H5)Fe{(η5-C5H4)-CH=N-(C6H4-2-C6H5)}]

The reaction of the novel ferrocenyl Schiff base: [(η⁵-C₅H₅)Fe{(η⁵-C₅H₄)-CH=N-(C₆H₄-2-C₆H₅)}] (1) with Na₂[PdCl₄] and Na(CH₃COO)·3H₂O in a 1:1:1 molar ratio in methanol is reported. In this reaction two different di-μ-chloro-bridged cyclopalladated complexes: [Pd{[(η⁵-C₅H₃)-CH=N-(C₆H₄-2-C₆H₅)]Fe(η⁵-C₅H₅)}(μ-Cl)]₂ (2a) and [Pd{[(C₆H₄-2-C₆H₄)-N=CH-(η⁵-C₅H₄)]Fe(η⁵-C₅H₅)}(μ-Cl)]₂ (2b) can be formed depending on the experimental conditions. Compounds 2a and 2b, which differ in the nature of the metallated carbon atom (C_{sp²,ferrocene} or C_{sp²,biphenyl}, respectively), undergo cleavage of the ‘Pd(μ-Cl)₂Pd’ bridges in the presence of thallium (I) acetylacetonate, deuterated pyridine or triphenylphosphine giving the monomeric derivatives: [Pd(C^∧N)(acac)] (3a, 3b) and [Pd(C^∧N)Cl(L)] {with L=py- d₅(4a, 4b), PPh₃(5a, 5b)}. The reactions of 2 with 1,2-bis(diphenylphosphino)ethane (dppe) reveal that the two isomers (2a and 2b) exhibit different reactivity versus dppe. These results have been interpreted on the basis of steric effects.     

Synthesis and structure of (boratabenzene)rhodacarborane (η-7,8-C2B9H11)Rh(η-C5H5BMe)

The bromide complex [(η-C₅H₅BMe)RhBr₂]₂ (1) was synthesized by the reaction of the cyclooctadiene derivative (η-C₅H₅BMe)Rh(1,5-C₈H₁₂) with Br₂. The reaction of compound 1 with Tl[Tl(η-7,8-C₂B₉H₁₁)] gave (boratabenzene)rhodacarborane (η-7,8-C₂B₉H₁₁)Rh-(η-C₅H₅BMe) (2). The structure of compound 2 was determined by X-ray diffraction     

The Thermolysis of [Ru3(CO)12] in Cyclohexene: Synthesis and Charaterisation of the New Clusters [Ru3H2(CO)9(μ3-η1:η2:η1-C6H8)] and [Ru5(CO)12(μ4-η2-C6H8)(η4-C6H8)]

Thermolysis of [Ru₃(CO)₁₂] in cyclohexene for 24 h affords the complexes [Ru(CO)₃(η⁴-C₆H₈)] (1), [Ru₃H₂(CO)₉(μ₂-η¹:η²:η¹-C₆H₈)] (2), [Ru₄(CO)₁₂(μ₄-C₆H₈)] (3) [Ru₄(CO)₉(μ₄-C₆H₈)(η⁶-C₆H₆)] (4a and 4b, two isomers) and [Ru₅(CO)₁₂(μ₄-η²-C₆H₈)(η⁴-C₆H₈)] (5), where 1, 3, 4a and 4b have been previously characterised as products of the thermolysis of [Ru₃(CO)₁₂] with cyclohexa-1,3-diene. The molecular structures of the new clusters 2 and 5 were determined by single-crystal X-ray crystallography, showing that two conformational polymorphs of 5 exist in the solid state, differing in the orientation of the cyclohexa-1,3-diene ligand on a ruthenium vertex.     

Organometallic polymorphism. Synthesis and structural characterization of two forms of [Ru(η6-C6H6)(η6-C6H4(CH3)COOCH3)][BF4]2 and the phase transition in [Ru(η5-C5H5)(η6-C6H5OH)][PF6]

The synthesis and structural characterization of the complex [Ru(η⁶-C₆H₆)(η⁶-C₆H₄(CH₃)COOCH₃)] [BF₄]₂ (2) and of its precursor [Ru(η⁶-C₆H₄(CH₃)COOCH₃)Cl₂]₂ (1) are reported. Compound (2) has been characterized in two polymorphic modifications (2a and 2b) and the molecular organization in the solid state has been investigated. The complex [Ru(η⁵-C₅H₅)(η⁶-C₆H₅OH)][PF₆] (3) has also been investigated; it has been shown to possess a disorder similar to that observed in the high temperature phase of related systems such as [Ru(η⁵-C₅H₅)(η⁶-C₆H₆)][PF₆].     

1,2-C4H6→2-C4H6异构化反应机理的理论研究

采用自洽场分子轨道UHF/6-31G**从头算法,研究了1,2-C4H6→2-C4H6异构化反应机理,优化了基态势能面上反应物、过渡态、中间体和产物的几何构型,并对各驻点能量进行了零点能校准.结果表明该反应经历一个1-甲基环丙烯生成产物比经两步氢迁移反应历程更易发生.     

Cyclooctaselenadiazole: synthesis,decomposition pathway,and reaction with (η5-C5H5) Co(L)2 (L = C2H4, PPh3). Crystal and molecular structure of [(η5-C5H5)CO]2(μ2-η3,η2-C8H6Se)

Thermolysis of cyclooctaselenadiazole (2) yields only selenium-containing products. Compound 2 reacts with CpCo sources to give [(η⁵-C₅H₅)CO]₂(μ₂η³,η²-C₈H₆Se), a fluxional compound whose structure has been determined by X-Ray crystallography.     

Syntheses,spectroscopic and structural studies of indenyl ruthenium complexes incorporating amine and nitrile ligands: molecular structures of [(η5-C9H7) Ru(η2-dppe)(CH3CN)]PF6 and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6

The reaction of [(η⁵-C₉H₇)Ru(η²-dppe)Cl] (1) with monodentate nitriles, (L) in the presence of NH₄PF₆ afforded the complexes [(η⁵-C₉H₇)Ru(η²-dppe)(L)]PF₆, with L?=?CH₃CN (2a), CH₃CH=CHCN (2b), NCC₆H₄CN (2c), C₆H₅CH₂CN (2d), respectively. However, reaction of 1 with NH₄PF₆ in methanol yielded an amine complex of the type [(η⁵-C₉H₇) Ru(η²-dppe)(NH₃)]PF₆ (3a). The complexes were fully characterized by spectroscopy and analytical data. The molecular structures of the complexes [(η⁵-C₉H₇)Ru(η²-dppe) (CH₃CN)]PF₆ (2a) and [(η⁵-C₉H₇)Ru(η²-dppe)(NH₃)]PF₆ (3a) have been determined by single crystal X-ray analyses.     

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.     

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.     

(η^5-C5H5)(η^5-C5H4R)TiCl2类化合物的新合成方法

本文报道了取代环戊二烯基负离子与[(η~5-C_5H_5)TiCl_2]_2O反应生成(η~5-C_5H_5)(η~5-C_5H_4R)·TiCl_2的新方法。研究了取代环戊二烯基负离子的空间位阻和(η~5-C_5H_5)TiCl_3,[(η~5-C_5H_5)TiCl_2]_2O的结构以及反应温度对产物产率的影响。合成了七个新的(η~5-C_5H_5)(η~5-C_5H_4R)TiCl_2类型的化合物及七个相应的二氟化合物。     

(η^5-C5H5)(η^5-C5H4R)TiCl2类化合物的新合成方法

本文报道了取代环戊二烯基负离子与[(η^5-C5H5)TiCl2]2O反应生成(η^5-C5H5)(η^5-C5H4R).TiCl2的新方法. 研究了取代环戊二烯基负离子的空间位阻和(η^5-C5H5)TiCl3, [(η^5-C5H5)TiCl2]2O的结构以及反应温度对产物产率的影响. 合成了七个新的(η^5-C5H5)(η^5C5H4R)TiCl2类型的化合物及七个相应的二氟化合物。     

Some reactions of [(η6-C6Me6)Ru(η6-[2.2]paracyclophane)]-[BF4]2 with nucleophiles

Single addition of the nucleophiles X⁻ (X = H, CN, OH) to the less sterically hindered ring in [(η⁶-C₆Me₆)Ru(η⁶-C₁₆H₁₆)][BF₄]₂ (1) proceeds smoothly to produce, as the sole product, [(exo-η⁵-C₆Me₆X)Ru(η⁶-C₁₆H₁₆)][BF₄]. Use of Na[BD₄] in place of Na[BH₄] gives the expected shift in ν(C-H_exo) in the infrared spectrum.     

Tetranuclear Bismuth Complex Bi4(O)2(O2CC6H2F3-3,4,5,)8 · 2η6-C6H5Me: Synthesis and Structure

Tetranuclear organobismuth complex Bi₄(O)₂(O₂CC₆H₂F₃-3,4,5)₈ · 2⁶-₆₅Me with four bismuth atoms joined via the bridging carboxylate ligands and oxygen atoms was studied using X-ray diffraction analysis. The coordination sphere of either of the two terminal bismuth atoms contains the chelate carboxylate ligand and the toluene molecule. For the bridging tricoordinated oxygen atoms, the Bi–O distances are 2.083(2), 2.119(2), and 2.276(2) Å. The average distance between the bismuth atom and the center of toluene molecule is equal to 3.131 Å.     

Syntheses of (η6-p-cymene)ruthenium(II) piano-stool amine complexes: molecular structure of [(η6-C10H14)RuCl2(H2N-C6H4-p-Cl)]

The dimeric complex [{(η⁶-p-cymene)Ru(μ-Cl)Cl}₂] (1) reacts with S,N-donor Schiff base ligands, para-substituted S-(thiophen-2-ylmethylene)phenylamines in methanol to give mononuclear amine complexes of the type [(η⁶-p-cymene)RuCl₂(NH₂–C₆H₄–p-X)] {X?=?H (2a); X?=?CH₃ (2b); X?=?OCH₃ (2c); X?=?Cl (2d); Br (2e) X?=?NO₂ (2f), respectively} by hydrolysis of the imine group of the ligand after coordination to the metal. The complexes were characterized by analysis and IR and NMR spectroscopy. The molecular structure of [(η⁶-C₁₀H₁₄)RuCl₂(H₂N–C₆H₄–p-Cl)] (2d) was established by a single-crystal X-ray diffraction study.     

Synthesis and Anti-inflammatory Action of （η-C5H5 ）2Ti（ Sal）2 and （η-C5H5 ）2Ti（Clo）2

IntroductionSince K pf[1]discovered that dicyclopenta die-nyltitanium dichloride possesses antitumour action in1979,a large number of cyclopentadienyltitanium com-plexes with different substituents have been synthe-sized[2,3].The experimental data reveal …     

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.     

The mechanism of fluxionality of (1,2,7-η3-2-Me-benzyl)(η5-C5H5)Mo(CO)2

It is shown that (1,2,7-η³-2-Me-benzyl)(η⁵-C₅H₅)Mo(CO)₂ exits in solution as one isomer which is fluxional, probably via (7-η¹-2-Me-benzyl)((η⁵-C₅H₅)Mo(CO)₂, with ΔG^≠₃₇₀ = 23.6 ± 1.0 kcal mol⁻¹. In contrast, (1,2,7-η³-3-Me-benzyl)(η⁵-C₅H₅)Mo(CO)₂ exits as two isomers at −20°C, which undergo interconversion at room temperature with ΔG^≠ 15.7 kcal mol⁻¹. This dynamic process is an allyl rotation. It is probable that there is also a low energy [1,5]-sigmatropic shift.     

Alcoholysis of hydridesilanes to give silyl ethers catalyzed by rhodacarboranes closo-3,3-(Ph3P)2-3-H-3,1,2-RhC2B9H11 and closo-3,3-(η2,η3-C7H7CH2)-3,1,2-RhC2B9H11

Rhodacarboranes closo-3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₁₁ and closo-(²,³-C₇H₇CH₂)-3,1,2-RhC₂B₉H₁₁ are catalysts for the alcoholysis of hydridesilanes. Closo-3,3-(²,³-C₇H₇CH₂)-3,1,2-RhC₂B₉H₁₁ displays greater activity than closo-3,3-(Ph₃P)₂-3-H-3,1,2-RhC₂B₉H₁₁ though both rhodacarboranes catalyze the alcoholysis of hydridesilanes more efficiently than (Ph₃P)₃RhCl.A. N. Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1657–1660, July, 1992.