碳锗双桥连二环戊二烯与羰基铁的反应

碳锗双桥连二环戊二烯(Me₂C)(Me₂Ge)(C₅H₄)₂(1)与五羰基铁在回流甲苯及二甲苯中的反应,得到正常的Fe-Fe键化合物(Me₂C)(Me₂Ge)[(η⁵-C₅H₃)Fe(CO)]₂(μ-CO)₂(3)和脱锗桥产物(Me₂C)[(η⁵-C₅H₄)Fe(CO)]₂(μ-CO)₂(4)以及一个结构新颖的化合物(Me₂C)[(η⁵-C₅H₃)[(Me₂Ge)Fe(CO)₂](η¹,η⁵-C₅H₃)[Fe(CO)₂](2).用X射线衍射分析測定了化合物3的晶体结构,并提出了可能的生成机理.     

开环茂金属成环及氢分子消除反应机理的理论研究

采用密度泛函方法(DFT)在M06-2X/def2-TZVPP//B3LYP/def2-TZVPP+ZPE水平下, 对以开环的(η⁵-C₅H₇)₂Ru为前驱体生成闭环(η⁵-C₅H₅)₂Ru的各种可能的反应路径进行了详细的研究. 最终确定其反应机理为: (η⁵-C₅H₇)₂Ru的一个η⁵-C₅H₇发生端碳成键的成环反应形成(η³-C₅H₇)Ru(η⁵-C₅H₇), 经过两步氢原子迁移到Ru原子上, 之后脱掉一个氢气分子形成(η⁵-C₅H₅)Ru(η⁵-C₅H₇), 而后另一个η⁵-C₅H₇再重复成环并进行两步氢迁移以及氢气分子消除而得到最终的产物(η⁵-C₅H₅)₂Ru.     

亚磷酸锌无机-有机杂化化合物的合成与结构表征

在水热条件下, 以1,6-己二胺为模板剂合成了一个三维(3D)亚磷酸锌无机-有机杂化化合物(C₆N₂H₁₆)_0.5ZnHPO₃(ZnHPO-CJ15), 并对其单晶结构进行了解析. 结果表明, ZnHPO-CJ15晶体属单斜晶系, P2₁/c空间群, a=1.19587(7) nm, b=0.82766(5) nm, c=0.77756(5) nm, α=90.00°, β=95.8370(10)°, γ=90.00°, V=0.76562(8) nm³, Z=1. ZnHPO-CJ15具有层柱状结构, 其骨架结构是由ZnO₃N四面体和HPO₃假四面体连接构成的二维4×8元环网层结构, 层与层之间由1,6-己二胺分子与Zn配位柱撑连接形成三维结构.     

一种新型钼钒多酸化合物的合成、结构与荧光性能

采用水热技术,合成了一种新型四帽Keggin结构多酸化合物[H₃Mo₈^ⅥV₈^ⅣO₄₀(AsO₄)](en)₂(4,4-bipy)₇·9H₂O(en:乙二胺;bipy:联吡啶)(1),并对化合物进行了元素分析、红外光谱、X射线光电子能谱和X射线单晶结构分析。 晶体结构分析表明, 化合物属三斜晶系,P1空间群,晶胞参数a=1.47395(5) nm,b=1.48172(6) nm,c=1.62881(7) nm,α=66.16(3)°,β=87.15(2)°,γ=63.42(1)°,V=2.8723(2) nm³,Z=1,R₁=0.0728,wR₂=0.2014。 化合物由四帽Keggin多酸阴离子、4,4'-联吡啶、乙二胺和结晶水分子构成,化合物分子间存在大量的氢键,使化合物1形成3-D超分子结构。 荧光测试表明,化合物1能发出较强的荧光,有可能成为潜在的光活性材料。     

芘基查尔酮的合成及三阶非线性光学性质

合成了一种新的具有潜在应用价值的非线性光学(NLO)有机材料1-(芘-1-基)-3-(4-二甲氨基苯基)丙烯酮(PMAK),并通过 NMR、IR、MS和元素分析等技术手段进行了表征。 采用溶液Nd:YAG激光技术测定了PMAK的三阶非线性光学性质并确定了相关参数。 纳秒实验结果:折射率n₂=-3.5×10^-17 m²/W,吸收系数β=7.0×10^-10 m/W,极化率χ⁽³⁾=2.54×10^-11 esu,分子超极化率γ=3.44×10^-30 esu;皮秒实验结果:n₂=-2.8×10^-18 m²/W,β=8.3×10^-11 m/W,χ⁽³⁾=2.49×10^-12 esu,γ=3.33×10^-31 esu。     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

1-二茂铁基-3-[(9-乙基)咔唑-3-基]丙烯酮的合成及三阶非线性光学性质

合成了一个新的非线性光学(NLO)有机材料1-二茂铁基-3-[(9-乙基)咔唑-3-基]丙烯酮(FCAK),并通过NMR、IR、MS和元素分析等技术手段进行了表征。 采用粉末Nd∶YAG激光技术测定了标题化合物的三阶非线性光学性质并确定了相关参数。 激光脉冲为4 ns时,非线性折射率n₂=-3.5×10^-18 m²/W,非线性吸收系数β=-2.7×10^-11 m/W,三阶非线性极化率χ⁽³⁾=2.04×10^-12 esu,三阶非线性分子超极化率γ=1.1×10^-30 esu。 激光脉冲为21 ps时,n₂=0.55×10^-18 m²/W,β=-0.6×10^-11 m/W,χ⁽³⁾=3.4×10^-13 esu,γ=0.13×10^-30 esu。     

α-二亚胺镍(Ⅱ)催化甲基丙烯酸甲酯聚合

以4种不同结构的α-二亚胺镍(Ⅱ)催化剂[(t-Bu)—N CH—CH N—(t-Bu)]NiBr₂(C1), [C₆H₅—N C(Me)—C(Me) N—C₆H₅]NiBr₂(C2), [(2,6-C₆H₃(Me)₂)—N C(Me)—C·(Me) N—(2,6-C₆H₃(Me)₂)]NiBr₂(C3)和[(2,6-C₆H₃(i-Pr)₂)—N C(An)—C(An) N—(2,6-C₆H₃(i-Pr)₂)]NiBr₂(An=acenaphthyl)(C4), 在甲基铝氧烷(MAO)作用下, 对甲基丙烯酸甲酯(MMA)进行催化聚合. 以C2为模型催化剂系统研究了Al/Ni摩尔比、 单体浓度、 聚合温度、 聚合时间和反应溶剂对催化活性及聚合物分子量的影响. 在较适合的聚合条件(催化剂用量为1.6 μmol, Al/Ni摩尔比为800, MMA浓度为2.9 mol/L, 甲苯为溶剂, 聚合温度为 60 ℃, 聚合时间为4 h)下, 讨论了催化剂结构对催化活性和聚合物分子量的影响. 研究发现, 催化剂C1~C3催化MMA聚合均得到富含间规结构的聚甲基丙烯酸甲酯(PMMA). 催化剂结构中空间位阻增大导致催化活性降低, 空间位阻最小的 C1催化活性最高[达107.8 kg/(mol Ni·h)]; 而空间位阻最大的C4催化活性仅为7.8 kg/(mol Ni·h). 催化剂结构中给电子效应增加有利于催化活性及聚合物分子量的增加. C2催化活性为62.5 kg/(mol Ni·h), 所得聚合物的分子量为5.0×10⁴; 而具有较强给电子效应的C3催化活性达到96.9 kg/(mol Ni·h), 并得到更高分子量的聚合物(7.6×10⁴).     

RCOO-取代的镍(Ⅱ)配合物单组分高效催化乙烯均聚和共聚反应

合成并表征了含RCOO-基团的单核(Ni¹~Ni²)及双核(Ni³)镍配合物[(2,6-R₂-C₆H₃)—N=C(H)—(3-Ph-5-PhCOO-2-O-C₆H₂)-κ²-N,O]Ni(CH₃)(pyridine)](R=iPr;3,5-tBu₂C₆H₃),并用于催化乙烯均聚和共聚反应。 作为单组分催化剂,这些配合物可以有效地催化乙烯聚合得到中等相对分子质量的支化聚乙烯(PE)。 供电性的PhCOO—基团促进了催化剂Ni¹的引发,从而在低温下比Ni⁰活性更高。 引入大位阻的2,6-(3,5-二叔丁基苯基)苯胺基团,催化剂Ni²在5×10⁵ Pa下的活性高达1.8×10⁶ g PE mol^-1·Ni^-1·h^-1,是活性最高的水杨醛亚胺中性镍催化剂之一。 与相应的单核催化剂相比,双核催化剂Ni³对三苯基膦具有更好的耐受性。 这些催化剂可催化乙烯与1,5-己二烯、1,7-辛二烯、6-溴-1-己烯或10-十一烯酸甲酯的共聚合,制备功能化聚乙烯。     

柳叶五层龙正丁醇提取部分中的3个新酚性成分及其α-葡萄糖苷酶抑制活性

采用多种色谱分离方法从柳叶五层龙(Salacia cochinchinensis Lour)的茎叶中分离得到5个化合物. 通过一维(1D)及二维核磁共振波谱(2D NMR), 包括核磁共振氢谱(¹H NMR)、 核磁共振碳谱(¹³C NMR)、 异核单量子相关(HSQC)、 异核多键相关(HMBC)、 氢氢相关(¹H-¹H COSY)和旋转坐标中的欧沃豪斯增强光谱(ROESY), 以及红外光谱(IR)和电喷雾电离高分辨质谱(ESI-HRMS)等方法, 鉴定其结构分别为Salaciacochinoside A(1), 5'-O-3,4,5-trimethoxybenzoyl-β-D-apiofuranoside(2), 5-methoxy-anticerol A(3), 21α,30-dihydroxy-D∶A-friedooleanan-3-one(4)和21α,26-dihydroxyfriedelan-3-one(5). 化合物1~3为新化合物. α-葡萄糖苷酶抑制活性测试结果显示, 化合物1和3对α-葡萄糖苷酶具有显著的抑制作用, 其IC₅₀值分别为0.32和0.59 μmol/L; 化合物2, 4和5未表现出α-葡萄糖苷酶抑制活性.     

A novel arene bonding mode in the mixed-metal cluster Os4Ru(μ-H) 3(CO) 12(μ3-η-C6H5) P(OMe)3

The ionic coupling of [Os₄H₂(CO)₁₂]²⁻ with [Ru(η⁶-C₆H₆)(MeCN)₃]²⁺ affords the neutral mixed metal cluster Os₄Ru(μH)₂(CO)₁₂(η⁶-C₆H₆) 1. The reaction of 1 with trimethylphosphite leads to the initial formation of the addition product Os₄Ru(μH)₂(CO)₁₂(η⁶-C₆H₆)P(OMe)₃ 2, but this complex rearranges in solution to give Os₄Ru(μ-H)₃(CO)₁₂(μ₃-η⁶-C₆H₅)P(OMe)₃ 3. An X-ray structure of 3 shows that the metal core of the cluster is a ruthenium-spiked Os₄ tetrahedron, with one hydrogen atom from the arene having transferred to the Os₄ core, and one arene carbon bridging an Os-Os edge, while the ring as a whole remains η⁶-bound to the Ru atom.     

π-Olefin-Iridium-Komplexe : XXI. Synthese und Kristallstrukturen heterobinuclearer Komplexe mit wannenförmiger, synfacial gebundener η: η-Benzolbrücke

CpIr(η⁴-C₆H₆) (2) has been obtained in high yield by a four-step synthesis. Thermal reaction of 2 with CpCO(C₂H₄)₂ and photochemical reaction of 2 with CpRh(C₂H₄)₂ or CpRh(C₂H₄)₂ give the compounds μ-(η³: η³-C₆H₆)CoIrCp₂ (3), μ-(η³: η³-C₆H₆)RhIrCp₂ (4), and μ-(η³: η³-C₆H₆)(RhCp)(IrCp) (5), respectively. The X-ray crystallography data of 3 and 4 reveal a boat-shaped conformation of the synfacially bridging benzene ligand with a rather long Co---Ir bond distance in 3 and a relatively short Rh---Ir bond length in 4 which are caused by almost constant folding angles of the benzene unit. The dynamic behaviour of the benzene bridge was investigated by NMR spectrometry.     

Interaction of half-sandwich alkylmolybdenum(III) complexes with B(C6F5)3. The X-ray structure of [CpMo(η-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3]

The reactions of the half-sandwich molybdenum(III) complexes CpMo(η⁴-C₄H₄R₂)(CH₃)₂, where Cp=η⁵-C₅H₅ and R=H or CH₃, with equimolar amounts of B(C₆F₅)₃ have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe₃. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η⁴-C₄H₆)(μ-Cl)(μ-CH₂)(O)MoCp][CH₃B(C₆F₅)₃], indicate that the borane attack has occurred at the methyl position.     

Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen : XLVI. Organoeisen-Komplexe mit Selen-Brücken

The nucleophilicity of the bridging atom of the selenium complex (μ-Se)[(η⁵-C₅H₅)Fe(CO)₂]₂ (1) has been demonstrated by addition of the complex cation [(η⁵-C₅H₅)Fe(CO)₂]⁺: Reaction of 1 with the ionic complex [(η⁵-C₅H₅)Fe(CO)₂-(THF)][BF₄] cleanly yields the ionic trinuclear complex [(μ₃-Se)(η⁵-C₅H₅)-Fe(CO)₂₃][BF₄] (3). This addition reaction converts the bridging selenium atom from a bent FeSeFe structure into a flattened Fe₃Se pyramid (X-ray diffraction studies), without significant changes in the iron-selenium bond lengths (244.9(<1) pm and 242.7(1)/243.3(1)/244.8(1) pm, respectively). These bonds are considered to be single bonds in accord with the EAN rule.     

Reactions of nickelocene with methyl-, ethyl- and vinyl-lithium compounds. Hydrogen elimination and cyclopentadienyl ring hydrogenation

It has been shown that bis(cyclopentadienyl)(μ-cyclopentadiene)dinickel, (NiCP)₂(η-C₅H₆), and (η⁵-cyclopentadienyl) (η³-cyclopentenyl)nickel, CpNi(η³-C₅H₇), are formed in the reaction of nickelocene with methyl-lithium and with 1-phenyl-2-methyl-propenyl-lithium. The compound (NiCp)₂(μ-C₅H₆) can be only formed as a result of the reduction of the cyclopentadienyl ring bonded to the nickel atom whereas the formation of CpNi(η³-C₅H₇) can be explained by the further hydrogeneration of cyclopentadiene formed in the earlier reaction steps. (NiCp)₂(μ-C₅H₆) has been fully characterised spectrometrically and its X-ray structure determined. It crystallises in the orthorhombic system, space group Pnma, with four molecules per unit cell.     

H NMR Spectra and electronic structure of binuclear niobocene and titanocene containing fulvalene ligands

¹H NMR spectra of binuclear metallocene hydride complexes, (η⁵ : η⁵-C₁₀H₈)(C₅H₅)₂M₂(μ-H)₂ (M = Nb, 20°C and Ti, (−60 to +25°C), were studied. The Nb complex is diamagnetic and gives a high resolution spectrum. The coordination of bridging hydride H atoms provides Nb atoms with complete 18 electron configuration. In its ground state, the Ti complex is also diamagnetic (the spectrum at −60°C agrees to that) in spite of only 17 electron configuration of each Ti atom. However, the population of the excited triplet state in the case of the Ti complex is appreciable at temperatures higher than −30°C, the proton resonance lines being shifted downfield and significantly broadened as compared with the spectrum at −60°C.     

Synthesis and electrochemistry of organometallic ethanethiolato bridged complexes of ruthenium(IV)

Reaction of the ruthenium(IV) chloro-bridged dimer [{Ru(η³ : η³-C₁₀H₁₆)Cl(μ-Cl)}₂], 1, with ethanethiol (EtSH) in CH₂Cl₂ gives the bridged-cleaved adduct [Ru(η³ : η³-C₁₀H₁₆)Cl₂(SHEt)], 2. Stirring of two molar equivalents of 2 in methanol with one equivalent of 1 gives the binuclear, mixed chloro/thiolato bridged compound [{Ru(η³ : η³-C₁₀H₁₆)Cl} ₂(μ-SEt)], 3. The related doubly thiolato bridged complex [{Ru(η³ : η³-C₁₀H₁₀)Cl(μ-SEt)}₂], 4, is formed by treatment of 1 with an excess of EtSH, or by prolonged stirring of 2 alone in methanol. Compounds 2–4 have been studied by cyclic voitammetry. Compound 2 undergoes only irreversible oxidation, whereas in the case of both 3 and 4 the observation of significant return waves is consistent with a greater stability of the primary redox products.     

Synthesis and crystal structure of the complex [MoW(OEt)(μ-CH2){μ-C(C6H4Me-4)C(Me)O}(η-C7H7)(η-C2B9H10Me)]

The complex [MoW(μ-CC₆H₄Me-4)(CO)₂(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)] reacts with diazomethane in Et₂O containing EtOH to afford the dimetal compound [MoW(OEt)(μ-CH₂){μ-C(C₆H₄Me-4)C(Me)O}(η⁷-C₇H₇)(η⁵-C₂B₉H₁₀Me)]. The structure of this product was established by X-ray diffraction. The Mo---W bond [2.778(4) Å] is bridged by a CH₂ group [μ-C---Mo 2.14(3), μ-C---W 2.02(3) Å] and by a C(C₆H₄Me-4)C(Me)O fragment [Mo---O 2.11(3), W---O 2.18(2), Mo---C(C₆H₄Me-4) 2.41(3), W---C(C₆H₄Me-4) 2.09(3), Mo---C(Me) 2.26(3) Å]. The molybdenum atom is η⁷-coordinated by the C₇H₇ ring and the tungsten atom is η⁵-coordinated by the open pentagonal face of the nido-icosahedral C₂B₉H₁₀Me cage. The tungsten atom also carries a terminally bound OEt group [W---O 1.88(3) Å]. The ¹H and ¹³C-{¹H} NMR data for the dimetal compound are reported and discussed.     

Stabile Bis(η-alkin)MCl2-komplexe; Darstellung und reaktivität

The synthesis and reactivity of {(η⁵-C₅H₄SiMe₃)₂Ti(CCSiMe₃)₂} MCl₂ (M = Fe: 3a; M = Co: 3b; M = Ni: 3c) is described. The complexes 3 are accessible by the reaction of (η⁵-C₅H₄SiMe₃) ₂Ti(CSiMe₃)₂ (1) with equimolar amounts of MCl₂ (2) (M = Fe, Co, Ni). 3a reacts with the organic chelat ligands 2,2′-dipyridyl (dipy) (4a) or 1,10-phenanthroline (phen) (4b) in THF at 25°C to afford in quantitative yields (η⁵-C₅H₄SiMe₃)₂Ti(CSiMe₃)₂ (1) and [Fe(dipy)₂]Cl₂ (5a) or [Fe(phen)₂]Cl₂ (5b). 1/n[Cu^IHal]_n (6) or 1/n[Ag^IHal]_n (7) (Hal = Cl, Br) react with {(η⁵ -C₅H₄SiMe₃)₂Ti(CCSiMe₃)₂}FeCl₂ (3a), by replacement of the FeCl₂ building block in 3a, to yield the compounds {(η⁵-C₅H₄SiMe₃)₂Ti(C CSiMe₃)₂}Cu^IHal (8) or {(η⁵-C₅H₄SiMe₃)₂Ti(CSiMe₃)₂}Ag^IHal (9) (Hal = Cl, Br), respectively. In 8 and 9 each of the two Me₃SiCC-units is η²-coordinated to monomeric Cu^I Hal or Ag^IHal moieties. Compounds 8 and 9 can also be synthesized by the reaction of (η⁵-C₅H₄SiMe₃)₂ Ti(CSiMe₃)₂ (1) with 1/n[Cu^IHal]_n (6) or 1/n [Ag^IHal]_n (7) in excellent yields. All new compounds have been characterized by analytical and spectroscopic data (IR, ¹H-NMR, MS). The magnetic moments of compounds 3 were measured.     

First examples of η- and η --- η-coordination in triphosphorus analogues of ferrocene. Crystal structure of the iron sandwich complex [Fe(η-C5H5) (η-C2R2P3)W (CO)5] (R = Bu)

Syntheses of the novel sandwich compounds [Fe(η⁵-C₅H₅)(η⁵-C₂R₂P₃)] and [Fe(η⁵-C₅H₅)(η⁵-C₂R₂P₃)W(CO)₅], (R = Bu^t), are described. The mode of attachment of the [W(CO)₅] fragment in the latter compound has been determined by NMR and single crystal X-ray diffraction studies.