Oxidation of theexo- andendo-phenylcyclohexadienyl iron complexes Fe(η5-6-PhC6H6) (η5- C5H5)

The roe of oxidatively induced homolyhc scission a the C(sp³)-H bonds in the iron phenykychhexadienyl complexes Fe(⁵-6-PhC₆H₆)(⁵-C₅H₅) (1) depends on the spatial orientation of the Ph substitutent. In the case of the (1 _endo ⁺) radical cation this process, resulting in the cationic biphenyl complex (Fe(⁶ -C₆H₅C₆H₅)(⁵-C₅H₅)]⁺ (2 ⁺), is fast and proceeds for several minutes. In the case of the more stable radical cation (1 _exo ⁺) the formation of 2⁺ is slow and takes tens minutes to complete.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1698–1700, July, 1996.     

Heats of formation of C(6)H(5)(•), C(6)H(5)(+), and C(6)H(5)NO by threshold photoelectron photoion coincidence and active thermochemical tables analysis

Threshold photoelectron photoion coincidence has been used to prepare selected internal energy distributions of nitrosobenzene ions [C(6)H(5)NO(+)]. Dissociation to C(6)H(5)(+) + NO products was measured over a range of internal energies and rate constants from 10(3) to 10(7) s(-1) and fitted with the statistical theory of unimolecular decay. A 0 K dissociative photoionization onset energy of 10.607 ± 0.020 eV was derived by using the simplified statistical adiabatic channel model. The thermochemical network of Active Thermochemical Tables (ATcT) was expanded to include phenyl and phenylium, as well as nitrosobenzene. The current ATcT heats of formation of these three species at 0 K (298.15 K) are 350.6 (337.3) ± 0.6, 1148.7 (1136.8) ± 1.0, and 215.6 (198.6) ± 1.5 kJ mol(-1), respectively. The resulting adiabatic ionization energy of phenyl is 8.272 ± 0.010 eV. The new ATcT thermochemistry for phenyl entails a 0 K (298.15 K) C-H bond dissociation enthalpy of benzene of 465.9 (472.1) ± 0.6 kJ mol(-1). Several related thermochemical quantities from ATcT, including the current enthalpies of formation of benzene, monohalobenzenes, and their ions, as well as interim ATcT values for the constituent atoms, are also given.     

The Synthesis of the Arene Clusters Ru6C(CO)14(η6-Arene) (Arene = C6H5CHMe2, C6H5C4H9, C6H5C3H7, and C6H5C3H5)

On reaction with Ru₃(CO)₁₂, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru₆C(CO)₁₄(⁶-C₆H₅CHMe₂) 1 and Ru₆C(CO)₁₄(⁶-C₆H₅C₄H₉) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru₆C(CO)₁₄(⁶-C₆H₅C₃H₇) 3 and Ru₆C(CO)14(⁶-C₆H₅C₃H₅) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature.     

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.     

Migration of the η1:η6-C6H5Cr(CO)3 ligand into the cyclopentadienyl ring during metallation of the η5-C5H5(CO)2Fe η1:η6-C6H5Cr(CO)3 binuclear complex

It was found that the ¹⁶-C₆H₅Cr(CO)₃ ligand migrates into the cyclopentadienyl ring when the ⁵-C₅H₅(CO)₂Fe ¹⁶-C₆H₅Cr(CO)₃ binuclear complex is metallated with BuⁿLi. Under the same conditions, no migration of the phenyl ligand in the ⁵-C₅H₅(CO)₂Fe ¹-C₆H₅ complex was observed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 325–326, February, 1994.     

Substitution and insertion reactions of (η5-C5H5)Cr(CO)3C2H5

The complex (η⁵-C₅H₅)Cr(CO)₃Cp42 H₅ has been made and its reactions with σ donor ligands L (L = (MeO)₃P and (EtO)₃P) and with SO₂ studied. The alkyl phosphites give compounds of the composition (η⁵-C₅H₅)Cr(CO)₂LC₂H₅, and sulfur dioxide gives the corresponding S-sulfinato (η⁵-C₅H₅)Cr(CO)₃SO₂C₂H₅.     

簇合物(μ-SC6H5)(μ-P(SC6H5)2)Fe2(CO)6的合成和晶体结构

用Fe_3(CO)_(12)与亚磷酸三硫代苯酯P(SC_6H_5)_3反应得到标题化合物。P(SC_6H_5)_3以其裂解分子片SC_6H_5和P(SC_6H_5)_2配位。用X-ray衍射技术测定了该化合物的晶体结构, 晶体属正交晶系, 空间群为Pbca, a=1.7422(7), b=1.0634(6), c=2.898(12) nm; V=5.370 nm, z=8, D_c=1.579 g·cm~(-3)。由直接法和差值Fourier合成解出全部非氢原子坐标, 并用全矩阵最小二乘法修正, 最后偏离因子R=0.054, R_w=0.058, 分子结构中心的Fe_2SP折叠环沿S…P线或沿Fe—Fe键折叠的二面角(分别为76.1°和82°)比其它具有中心Fe_2S_2, Fe_2P_2和Fe_2SP折叠环的类似化合物中的相应值小, Fe—Fe键长为0.2572 nm, Fe—S(1)—Fe=68.6°, Fe—P—Fe=70.7°。     

Molecular structure of two dicyclopentadienylmolybdenum derivatives containing a four-membered ring [Mo(η5-C5H5)2(2-NHNC5H4)][PF6] and [Mo(η5C5H5)2(2-ONC5H4)][PF6]

The structure of the new compound [Mo(η⁵-C₅H₅)₂(2-NHNC₅H₄)][PF₆] (1) has been determined. The crystals are orthorhombic, space group Pca2₁ with a 20.807(1), b 8.0030(8), c 10.056(3) Å, V 1674.5 ų, Z = 4. The structure of [Mo(η⁵-C₅H₅)₂(2-ONC₅H₄)][PF₆] (2) has also been determined. The crystals are orthorhombic, space group Pnma with a 12.727(3), b 10.174(2), c 12.918(1) Å, V 1672.8 ų, Z = 4. The structures were solved by Patterson and difference electron density syntheses and refined by least-squares to R of 0.028 for 1287 reflections for 1 and 0.059 for 1178 reflections for 2.Although not isostructural the two cationic complexes have equivalent geometries with the normal bent bismetallocene structure. For 1 the MoN bond lengths are 2.160(8) and 2.142(9) Å, with a NMoN bond angle of 59.8(3)°, whereas for 2 MoO is 2.142(10), MoN is 2.138(11) Å, the NMoO angle is 61.2(4)°. These parameters are discussed and compared with the corresponding data for similar biscyclopentadienyl complexes of molybdenum(IV). Extended Hückel molecular orbital calculations have been carried out to throw light on the nature of the bonding between the metal and the bidentate ligand.     

Insertion reactions of t-Bu(η5-C5H5)Fe(CO)2

The complex t-Bu(η⁵-C₅H₅)FE(CO)₂ has been treated with triphenylphosphine in refluxing THF to produce t-BuCO(η⁵-C₅H₅)Fe(CO)(PPh₃). The large steric bulk of the t-butyl group suggests that this reaction should be faster than the reaction involving the methyl group, and a kinetic investigation illustrates this to be the case. The same steric bulk predicts that the reaction with SO₂ should be slow, and indeed we have been unable to effect the related SO₂ insertion reaction. Attempts to prepare the corresponding t-Bu(η⁵-C₅H₅)W(CO)₃ led to formation of the related isobutyl complex.     

The Structure of Pd2(CH≡CC6H5)2(C5H7O2)3(BF3)2BF4

IR and NMR data showed that the ionic complex Pd₂(CHCC₆H₅)₂(C₅H₇O₂)₃(BF₃)₂BF₄ isolated in the reaction Pd(Acac)₂ + PA + 5BF₃OEt₂ (Acac is C₅H₇O₂, PA is phenylacetylene) is an adduct of two complexes, namely, (Acac)PdBF₄ and [(PA)₂Pd(C³-Acac · BF₃)]⁺(Acac · BF₃)^– (coordinatively unsaturated). On dissolution in deuteroacetone or deuteromethanol, the [(Acac)PdF₂BF₂Pd(C³-Acac · BF₃)(PA)₂]⁺(Acac · BF₃)^– adduct decomposed to Pd(Acac)₂, 2BF₃ · L (L = (CD₃)₂CO, CD₃OD) and the [L(PA)₂Pd(C³-Acac]⁺BF₄ ^– complex.     

The X-ray crystal structure of di-η5-cyclopentadienylthiophenolatoamminemolybdenum(IV) hexafluorophosphate solvate [Mo(η5-C5H5)2(NH3)(SC6H5)][PF6] · (CH32CO

Crystals of [Mo(η⁵-C₅H₅)₂(NH₃)(SC₆H₅)][PF₆] · (CH₃)₂CO solvate are monoclinic, space group P2₁/n, a 9.777(1), b 11.6343(2), c 19.656(4) Å, β 93.60(1)°, V 2231-46 ų, Z  D_c 1.617 g cm⁻³, μ(Mo-K_α) 7.21 cm⁻¹. The structure was solved by Patterson and difference Fourier electron density synthesis and refined to R (F)  0.047 and R_w(F)  0.057 for 3293 observed reflections. The molybdenum atom has the usual distorted tetrahedral geometry comprising the two MoCp (Cp  η⁵-C₅H₅) ring normals (MoCp 1.988(13), 1.989(15) Å), one Mo-NH₃ (MoN 2.226(12) Å), and one MoSc₆H₅ (MoS 2.465(5) Å). Extended HMO and steric energy calculations were made in order to account for the geometry adopted by the thiolato ligand in this complex.     

Synthesis and Crystal Structure of an Ionic Compound [Fe(CN)6(phCH2NC5H5)3]·(H2O)4

A novel ionic compound [Fe(CN)6(phCH2NC5H5)3]·(H2O)4(Mr = 794.71) has been synthesized and its structure was characterized by IR, elemental analysis and X-ray diffraction. The compound crystallizes in monoclinic, space group P21/c with a = 10.837(2), b = 16.551(3), c = 23.402(5) (A), β = 97.531(4)°V = 4161.0(15)(A)3, Z = 4, Dc = 1.269 g/cm3, F(000) = 1668, μ = 0.414 mm-1, R = 0.0479 and wR = 0.1232. The building unit of the title compound consists of three (phCH2N C5H5) ions, one [Fe(CN)6]3- anion and four water molecules. According to the structural analysis, [Fe(CN)6]3- are linked together by O-H…N and O-H…O hydrogen bonds, but [Fe(CN)6]3- and [(phCH2N C5H5)3] ions are bound by electrostatic force to form an ionic compound.Keywords: N-benzyl-pyridine, ferricyanic anion, crystal structure, supramolecular, ionic compound.     

Synthesis and structure of neutral π-arene complex (η6-C6H5Me)U(AlCl4)3

A new neutral -arene complex of trivalent uranium, (⁶-C₆H₅Me)U(AlCl₄)₃ (1), was obtained by the reductive Freidel-Crafts reaction. The crystal structure of 1 was determined by single crystal X-ray diffraction analysis. The U atom in 1 is bound to the C₆H₅Me group by the ⁶ mechanism and is linked to the three AICl₄ groups through two g-CI bridges. The coordination of the U atom is a distorted pentagonal bipyramid in which the center of the arene ring is in one apical position, and the bridging Cl atoms occupy the other vertices.Translated from Izvestiva Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 469–472, February, 1996.     

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.     

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].     

Detection of σ-alkane complexes of manganese by NMR and IR spectroscopy in solution: (η5-C5H5)Mn(CO)2(ethane) and (η5-C5H5)Mn(CO)2(isopentane)

Irradiation of CpMn(CO)₃ in liquid ethane at 135 K at 355 nm yields a photoproduct that exhibits ν(CO) bands in the IR spectrum shifted to low wavenumber with respect to CpMn(CO)₃ that are indicative of a Mn(i) dicarbonyl. Parallel experiments employing in situ irradiation within an NMR probe (133 K, 355 nm photolysis) reveal the ¹H NMR signals of this product and confirm its formulation as the σ-ethane complex CpMn(CO)₂(η²-C1–H-ethane). The resonance of its coordinated C–H group is observed at δ –5.84 and decays with lifetime of ca. 360 s. Analogous photolysis experiments in isopentane solution with IR detection produce CpMn(CO)₂(η²-C–H-isopentane) with similar IR bands to those of CpMn(CO)₂(η²-C–H-ethane). ¹H NMR spectra of the same species were obtained by irradiation of CpMn(CO)₃ in a 60 : 40 mixture of propane and isopentane; three isomers of CpMn(CO)₂(η²-C–H-isopentane) were detected with coordination of manganese at the two inequivalent methyl positions and at the methylene group, respectively. The lifetimes of these isomers are ca. 380 ± 20 s at 135 K and do not vary significantly from each other. These σ-complexes of manganese are far more reactive than those of related CpRe(CO)₂(alkane) complexes which are stable in solution at 170–180 K. The room temperature lifetimes of CpMn(CO)₂(η²-C–H-ethane) and CpMn(CO)₂(η²-C–H-isopentane), as determined by TRIR spectroscopy, are 2.0 ± 0.1 and 28 ± 1 μs, respectively.     

A Convenient Synthesis of 2,4(3H,5H)-Furandione (β-Tetronic Acid)

The chemical versatility of 2,4(3H,5H)-furandione (β-tetronic acid, 1) and its synthetic applicability are of considerable current interest^1b,2a-k. The multifunctional character of this small molecule confers an intriguing synthetic potential which has prompted us to develop synthetic schemes utilizing it as a synthon for certain heterocyclic systems.     

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.     

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.