Metallaborane reaction chemistry: Part 8. Phenylacetylene trimerisation by [6,6,6-(PPh3)2H-nido-6-IrB9H13] and the structure of [2-(η6-C6H3Ph3)-closo-2-IrB9H8-10-(PPh3)] by synchrotron X-ray diffraction analysis

The microwave-heated reaction between PhCCH and [6,6,6-(PPh₃)₂H-nido-6-IrB₉H₁₃] gives [2-(η⁶-C₆H₃Ph₃)-closo-2-IrB₉H₆-10-(PPh₃)] (29%) and thereby demonstrates acetylene trimerisation on a metallaborane matrix.     

Formation of [8,8-η2-{(μ-Cl)2Ru(η6-p-cym)Ph2PCH2PPh2}-nido-8,7-RhSB9H10], a bimetallic derivative of the novel species [8,8-(η2-dppm)-8-(η1-dppm)-nido-8,7-RhSB9H10]

Treatment of [8,8-(η²-dppm)-8-(η¹-dppm)-nido-8,7-RhSB₉H₁₀] (I) with [Ru(η⁶-p-cym)Cl₂]₂ leads to the formation of a new bimetallic complex, [8,8-η²-{(μ-Cl)₂Ru(η⁶-p-cym)Ph₂PCH₂PPh₂}-nido-8,7-RhSB₉H₁₀], (II) containing the group [(μ-Cl)₂Ru(η⁶-p-cym)Ph₂PCH₂PPh₂] that coordinates in a multidentate mode to Rh.     

Synthesis of UHMW-PE by a Highly Active Homogeneous System: η5-(C5H5)2Ti(η1-OC(O)C6H5)2/MAO

Summary The complex ⁵-(C₅H₅)₂Ti (¹-OC(O)C₆H₅)₂ was synthesized and activated with MA0 for ethylene polymerization. The resultant polymer is UHMW-PE with a viscosimetric molecular weight of Mv = 6.8 x 10⁶ to 0.7 x 10⁶ g/mol dependent on the temperature of the reaction. The effects of the Al/Ti molar ratio and temperature of the reaction on the catalytic activity and polymer properties were studied.     

The synthesis and characterization of two new 19-vertex metallaborane clusters: [B18H20Ni(η5-C5H5)]−1 and [B18H19(2-THF)Ni(η5-C5H5)]

Two new 19-vertex metallaboranes, [B₁₈H₂₀Ni(η⁵-C₅H₅)][N(CH₃)₄] and [B₁₈H₁₉(2-THF)Ni(η⁵-C₅H₅)], were isolated from the reaction of anti-B₁₈H₂₂ with nickelocene, [Ni(η⁵-C₅H₅)₂], in high yields. The complexes were characterized by multinuclear NMR (¹H, ¹³C, ¹¹B), IR and UV–vis spectroscopy. Single-crystal X-ray diffraction analyses of these new complexes confirmed their structures as 19-vertex conjuncto-metallaborane clusters.     

Semi-rigid N-para-ferrocenyl(benzoyl)amino-acid esters for biomaterials: synthesis and characterization of Fc-C6H4CONHCH(R)CO2Me where Fc = (η5-C5H5)Fe(η5-C5H4) and R=H,CH3,CH2CH(CH3)2,CH2C6H5 and the X-ray crystal structures of Fc-C6H4CO2Me and the l-alanine derivative Fc-C6H4CONHCH(CH3)CO2Me

A series of N-para-(ferrocenyl)benzoyl amino-acid esters, para-Fc(C₆H₄)CONHCH(R)CO₂CH₃ {Fc = (η⁵-C₅H₅)Fe(η⁵-C₅H₄); R = H, CH₃, CH₂CH(CH₃)₂, CH₂C₆H₅}, 3–6 have been prepared by coupling para-(ferrocenyl)benzoic acid to the amino-acid esters (gly, l-Ala, l-Leu, l-Phe) using the standard 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) protocol. The compounds were fully characterized by a range of spectroscopic techniques including FAB-MS. The X-ray crystal structures of the parent para-(ferrocenyl)benzoyl methyl ester, Fc-C₆H₄CO₂Me, 1 and a chiral derivative N-{para-(ferrocenyl)benzoyl}-l-alanine methyl ester, Fc-C₆H₄CONHCH(CH₃)CO₂Me, 4 have been determined.     

Ru4(μ-CO)(CO)9(η4-μ4-C6H4)(η2-μ1,μ4-PPhCH2CH2PPh2): an unusual pyrolysis product of Ru3(CO)10(dppe) containing a benzyne ligand

The thermal decomposition of Ru₃(CO)₁₀(dppe) in refluxing benzene gives, in contrast to the pyrolysis of the dppm analogue, the tetranuclear cluster Ru₄(μ-CO)(CO)₉(η⁴-μ₄-C₆H₄)(η²-μ₁,μ₄-PCH₂CH₂PPh₂) (1) along with Ru₃(CO)₉(η²-μ₁,μ₂-C₆H₅)(η³-μ₁,μ₂-PPhCH₂CH₂PPh₂) (2). The single-crystal structure analysis of 1 reveals a square-planar tetraruthenium skeleton containing a η⁴-μ₄-benzyne ligand as well as a η²-μ₁,μ₄-phosphinidene–phosphine ligand.     

Zirconocene complexes of the sterically demanding pentaphenylcyclopentadienyl ligand,CpPRO. Synthesis and characterization of CpPROZrCl3 and CpCpPROZrCl2 (Cp=η5-C5H5; CpPRO=η5-C5(C6H5)5)

The synthesis, characterization and X-ray structures of two zirconium complexes of the bulky pentaphenylcyclopentadienyl ligand, Cp^PRO, are reported. The monocyclopentadienyl 12 electron complex, Cp^PROZrCl₃ (I), has an unusual monomeric structure in the solid state and has short Zr–ligand distances. The Lewis acidity of this complex is manifested in its ability to catalyze the [4+2] cycloadditions of methyl- and ethylmethacrylate to cyclopentadiene. The sandwich complex, Cp^PROCpZrCl₂ (II), has more typical Zr–ligand distances, but has a more parallel arrangement of the two cyclopentadienyl rings.     

Electrochemical anion recognition by redox-responsive unnatural amino acid derivatives; the X-ray crystal structure of N-ferrocenoyl glycine methyl ester, (η5-C5H5)Fe(η5-C5H4)CONHCH2COOMe

N-Ferrocenoyl glycine ester derivatives FcCONHCH₂COOR (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄); R=methyl (1), ethyl (2) and benzyl (3)) have been prepared by coupling ferrocene carboxylic acid to a series of glycine esters using 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBT) and Et₃N in CH₂Cl₂. The electrochemical anion sensing using a platinum microdisk working electrode of these N-ferrocenoyl glycine ester derivatives is reported. The crystal structure of 1 has been determined; principal dimensions are amide N(H)CO 1.229(3) Å, ester CO 1.183(3) Å with N–H⋯OC(amide) as the primary intermolecular hydrogen bond, N⋯O 2.804(3) Å.     

Hydrothermal synthesis,crystal structure and physical properties of {[Gd(H2O)4(μ2-C6NO2H5)2Gd(H2O)4](μ3-C6NO2H4)2(ZnCl3)2} · 2H2O · 2Cl

A bimetallic 4f–3d tetranuclear complex {[Gd(H₂O)₄(μ₂-C₆NO₂H₅)₂Gd(H₂O)₄](μ₃-C₆NO₂H₄)₂(ZnCl₃)₂} · 2H₂O · 2Cl (1) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Complex 1 is characterized by a tetranuclear Gd₂Zn₂ structure with the gadolinium and zinc atoms interconnected by isonicotinic acid ligands. The tetranuclear species of {[Gd(H₂O)₄(μ₂-C₆NO₂H₅)₂Gd(H₂O)₄](μ₃-C₆NO₂H₄)₂(ZnCl₃)₂} link to isolated chlorine ions and water molecules via π?π interactions and hydrogen bonds to yield a 3-D supramolecular framework. Photoluminescent investigation reveals that the title complex displays an emission in ultraviolet region. The solid-state diffuse reflectance spectra of 1 reveal the presence of a sharp optical gap of 3.66 eV.     

Synthesis of the sterically constrained ligand precursor cyclopentadienyl-2,6-diphenylbenzene and structure of [(2,6-Ph2–C6H3-η5-C5H4)Zr(NEt2)3]

A Pd-catalysed Stille coupling of 2,6-diphenyliodobenzene with tributylcyclopentadienyltin gave the sterically constrained ligand precursor cyclopentadienyl-2,6-diphenylbenzene (1). Treatment of this precursor with tetrakis(diethylamido)zirconium(IV) gave the three-legged piano-stool complex [(2,6-Ph₂–C₆H₃-η⁵-C₅H₄)Zr(NEt₂)₃] (2). Complex 2 was characterised by ¹H- and ¹³C{¹H}-NMR spectroscopy as well as by X-ray crystallography which showed significant distortions of the three-legged piano-stool geometry as a result of steric interactions with the bulky aryl substituent.     

2-溴-6-氯-3(2H)-苯并呋喃酮的合成

2-溴-6-氯-3(2H)-苯并呋喃酮是合成具有稠杂环结构杀虫剂的中间体.从4-氯水杨酸开始,运用新颖的方法,经过酯化、成醚、水解、闭环、溴代5步化学反应得到产物,总收率19%.产品结构经质谱、核磁共振氢谱确认正确.     

Thermal dehydration of Y(TFA)3(H2O)3: Synthesis and molecular structures of [Y(μ,η1:η1-TFA)3(THF)(H2O)]1∞ · THF and [Y4(μ3-OH)4(μ,η1:η1-TFA)6(η1-TFA)(η2-TFA)(THF)3(DMSO)(H2O)] · 6THF (TFA = trifluoroacetate)

In order to obtain a better anhydrous precursor for various applications in materials science and catalysis, thermal dehydration reactions of Y(TFA)₃(H₂O)₃ (TFA = trifluoroacetate) (A) were investigated. Thermal treatment of A at different temperatures under vacuum (5 × 10^?2 mm) for several hours failed to give totally anhydrous yttrium trifluoroacetate (as indicated by IR). Two different complexes, a partially dehydrated [Y(μ,η¹:η¹-TFA)₃(THF)(H₂O)]_1∞·THF (1) and a partially hydrolyzed [Y₄(μ₃-OH)₄(μ,η¹:η¹-TFA)₆(η¹-TFA)(η²-TFA)(THF)₃(DMSO)(H₂O)] · 6THF (2), were obtained with good and moderate yield, respectively, by crystallization of two different thermally treated batches of A from THF (or THF + DMSO) at room temperature. More efficient dehydration of A could be achieved at 200 °C in a furnace, the obtained anhydrous yttrium tris-trifluoroacetate giving Y(TFA)₃(THF)₂ (3) on crystallization from THF. All the products were characterized by elemental analyses, FT-IR and ¹H NMR spectroscopy as well as thermo-gravimetric analysis. In addition, single crystal X-ray structures are reported for 1 and 2, which show either a terminal (η¹ and η²) or bridging (μ,η¹:η¹) bonding behavior of the TFA ligand.     

An unusual intramolecular metallalactone formation from coordinated alkoxide and CO: molecular structure of Au3Ru3{μ3-η1:η1:η1,η2-CCHCPh2OC(O)}(CO)8(PPh3)3

Sequential treatment of Ru₃(μ-H){μ₃-C₂CPh₂(OH)}(CO)₉ with K[BHBu^s₃] and AuCl(PPh₃) afforded Au₃Ru₃{μ₃-η¹:η¹:η¹,η²-CCHCPh₂OC(O)}(CO)₈(PPh₃)₃, formed by intramolecular attack of alkoxide on an adjacent CO ligand, and characterised by a single-crystal X-ray study.     

CO2-C2H6共沸物分离的立方型状态方程选取

汽液平衡热力学模型的准确选取对CO₂-C₂H₆共沸物分离流程的设计和操作分析至关重要。在汽液平衡实验数据的基础上,依据逸度平衡原则,评估vdW、RK、SRK和PR立方型状态方程结合vdW、Margles和CVD混合规则预测CO₂纯物质、CO₂-C₂H₆共沸物和n-C₅H₁₂-CO₂-C₂H₆三元体系汽液平衡的可靠性,采用平均绝对误差的方法进行状态方程的选取。结果表明：SRK状态方程计算CO₂纯物质汽液平衡性质的精度最高;PR状态方程结合Margles混合规则可以准确计算CO₂-C₂H₆共沸体系汽液平衡特性;对于n-C₅H₁₂-CO₂-C₂H₆三元体系,SRK状态方程结合Margles混合规则计算精度明显优于vdW、RK和PR状态方程。通过试差迭代法优化CO₂-C₂H₆共沸体系和n-C₅H₁₂-CO₂-C₂H₆三元体系的二元交互作用参数,状态方程的计算精度得到明显提高。     

Theoretical study of the reactive intermediate Si2Me4[(η5-C5H4) Fe(CO)2] 2 2−

In two previous papers (Kinget al., J. Organomet. Chem. 19, 327, 1969; Pannellet al., Organometallics 9, 859, 1990), the synthesis and X-ray structure of the two tetramethyl disilyl complexes [(η⁵-C₅H₅) Fe(CO)₂]₂Si₂Me₄ (I) and Si₂Me₄[(η⁵-C₅H₄) Fe(CO)₂CH₃]₂ (II) were reported. ComplexII is obtained fromI [2]. However, attempts to form other derivatives fromI have generally failed. In the chemical process to getII fromI, an intermediate complex, Si₂Me₄[(η⁵-C₅H₄) Fe(CO)₂] ₂ ^2? (III), is probably formed. This is similar to complexII without the two methyl groups bonded to the Fe atoms. Therefore, a theoretical study that may shed some light on the intermediate structure, stability, and reactivity is justified. We have developed theoretical studies consisting of extended Huckel electronic structure calculations on the simulated intermediate geometry. The results obtained from these calculations suggest that it might be stable enough to form during reactions of complexI. The more reactive sites, which suggest reaction alternatives, are pointed out.     

A convenient method for the synthesis of [Pd{[(η5-C5H3)–CHN–(CH2)2–NMe2]Fe(η5-C5H5)}Cl] and the study of its reactivity with diphosphines

A one-pot method for the preparation of [Pd{[(η⁵-C₅H₃)–CHN–(CH₂)₂–NMe₂]Fe(η⁵-C₅H₅)}Cl] is described. Its X-ray crystal structure and its reactions with the diphosphines Ph₂P–(CH₂)_n–PPh₂ {with n=1 (ddpm) or 2 (dppe)} are also reported.     

[(η6-p-PriC6H4Me)2Ru2Mo2O6(OMe)4]: a new tetranuclear mixed-metal oxo cluster presenting a cube-based chair structure

The title complex was obtained by reaction of [(η⁶-p-PrⁱC₆H₄Me)₄Ru₄Mo₄O₁₆] with methanol in the presence of p-hydroquinone. It contains an Mo₂Ru₂O₂(OMe)₄ core consisting of two Mo₂RuO(OMe)₃ half-cubes fused together to form a chair-like structure.     

Synthesis and structure of the cubane type [Fe2Sb(CO)5(η5-C5H5)]4 cluster

The [Fe₂Sb(CO)₅Cp]₄ (Cp=η⁵-C₅H₅) cluster has been obtained by the thermolysis of [Et₄N][{Fe(CO)₄}₂{Fe(CO)₂Cp}SbI]. The structure of the [Fe₂Sb(CO)₅Cp]₄·2toluene solvate has been determined by X-ray analysis. The cluster contains the cubane [Fe₄Sb₄] core. Each Sb serves as a μ₄-ligand between three iron atoms of the core and one of a terminal [Fe(CO)₂Cp] group.