苯钕络合物的合成及其对丁二烯聚合的催化活性

利用热原子蒸汽法合成稀土金属有机化合物,近几年来才有报导。Evans等报导了用La、Sm、Nd、Er、Yb等金属原子蒸汽与乙烯、丙烯、丁二烯、1,2-丙二烯和已炔反应合成稀土有机金属络合物。Dekock曾将La、Ce、Nd、Er、Yb等稀土金属原子与环辛四烯反应,分别得到有机金属给合物,[La₂(C₈H₈)₃]·2C₄H₈O;Ce₂(C₈H₈)₃;[Nd₂(C₈H₈)₃]·2C₄H₈O;Yb(C₈H₈);[Er₂(C₈H₈)₃]·2C₄H₈O。本文研究了金属钕在高温高真空下所产生的蒸汽与苯在-196℃反应的规律和所得产物组成和性质。     

[C5H5Fe(CO)2]LnCl2·nTHF和[C5H5Fe(CO)2][C5H4(SiMe3)]LnCl·nTHF双核配合物的合成

合成了稀土铁双核配合物:(C₅H₅Fe(CO)₂)LnCl₂·nTHF(Ln=Nd,Sm,Gd;n=1,2)和(C₅H₅Fe(CO)₂)(C₅H₄(SiMe₃))·LnCl·nTHF(Ln=Nd,Sm,Gd;n=0,1,2)。元素分析,热分析,红外光谱和质谱分析确认了这两种配合物。红外光谱数据表明铁与稀土原子是以羰基桥连接。晶体结构分析表明((C₅H₅Fe(CO)₂)Na·4THF是(C₅H₅Fe(CO)₂)LnCl₂·nTHF合成的中间体。     

Nd(O-i-C3H7)2Cl的直接合成法

Nd(O-i-C₃H₇)₂Cl可作为Ziegler-Natta催化剂中的主要成分用于共扼双烯的定向 聚合^[1],其常用合成方法^[1]需添加CH₃COCl: 我们在实验中发现,Nd(O-i-C₃H₇)₂Cl和异丙醇形成的络合物在苯-异丙醇混合溶液中并不沉淀析出,从而可用NdCl₃·3HO-i-C₃H₇,和NaO-i-C₃H₇,直接合成Nd(O-i-C₃H₇)₂Cl。     

硝酸铕18-C-6(4:3)络合物的晶体结构

标题化合物的分子式为[Eu(NO₃)₆][Eu(NO₃)₂C₁₂H₂₄O₆]₃。晶体属单斜晶系,空间群为C2/m,a=28.772(6),b=11.142(2),c=12.024(2)Å,β=112.63(2)°,Z=2。对1167个可观察反射(I≥3σ(I)),用块矩阵最小二乘法精修所有的结构参数,最后的一致性因子R=0.063。结构分析表明:晶体学上有三个不同的离子,(1)[Eu(NO₃)₆]^3-,(2)[Eu(NO₃)₂C₁₂H₂₄O₆]⁺(有序)和(3)[Eu(NO₃)₂C₁₂H₂₄O₆]⁺(无序)。前两个离子都具有C_2h对称性。第三个离子是C₁对称性,它有一个无序的冠醚环。在Fourier图上二个冠醚环叠加,它们的相互交错角为32°。     

六氯化铈三烷基鏻的合成

合成了三个新的(HPR₃)₂CeCl₆络合物,其中R=C₂H₅,C₃H₇,C₄H₉。络合物经元素分析,红外和紫外光谱鉴定。用热重分析法研究了这些络合物的热分解行为,结果表明,它们于分解温度时,都首先失去一个氯原子。     

二环戊二烯基氯化钕的合成

用NdCl₃·2 THF和环戊二烯的(摩尔比)比为1:1.8在四氢呋喃(THF)溶液中室温反应得到二环戊烯基氯化钕四氢呋喃络化物(C₅H₅)₂NdCl·THF。元素分析,红外光谱和X光电子能谱的数据证实了这一化合物的存在。在抽空加热下脱去THF得到组成符合(C₅H₅)₂NdCl的淡紫色的残余物。     

光引发阳离子聚合反应的研究——Ⅱ.硫鎓盐DPTS引发乙烯基正丁醚光聚合动力学

以二苯基-4-苯硫基代苯基硫鎓盐(DPTS)为光引发剂,研究了乙烯基正丁醚的本体和溶液光聚合。在本体聚合中,聚合速率(R_p)与引发剂浓度成正比;在15～35℃范围内,聚合活化能几乎为零。分别以CHCl₃(CH₂Cl)₂和C₆H₅Cl作溶剂的溶液聚合,其R_p均比本体聚合者大,同时单体浓度对R_p的影响则表现出复杂的关系。根据普遍接受的硫鎓盐光解机理并假设溶剂和单体均可不同程度地参与引发反应,解释了溶液聚合中单体影响的动力学规律。     

稀土元素与马来酸和邻菲咯啉三元固态配合物的研究

合成了13种由稀土离子(La³⁺、Pr³⁺、Nd³⁺、Sm³⁺-Yb³⁺和Y³⁺)与马来酸(C₄H₄O₄)和邻菲咯啉(Phen)形成的三元配合物。元素分析和微量水分测定确定其组成为Ln₂(C₄H₂O₄)₃(Phen)₂·4H₂O.研究了它们的紫外,红外吸收光谱,探讨了配合物的荧光性质及热稳定性。     

五氯化二氧六环合铈(Ⅳ)及其铵盐配合物的合成

本文用氢氧化铈(Ⅳ)在二氧六环中,通入干燥的HCl气体,得到了热稳定性较好的四或五氯化二氧环合铈(Ⅳ)配合物-Ce(C₄H₈O₂)₄Cl₄或HCe(C₄H₈O₂)₄Cl₅。并将五氯化二氧六环合铈(Ⅳ)配合物与不同的含氮化合物配合,合成了一些新的五氯化二氧六环合铈铵盐配合物(HL)Ce(C₄H₈O₂)_xCl₅(L=8-羟基喹啉、咪唑、邻啡啰啉、吡啶、氮杂菲、吩嗪;x=1,2,3,4)。上述配合物通过元素分析、红外光谱、紫外光谱、热分析和电子能谱进行了鉴定。研究了不同的含氮化合物对四价铈氯化物热稳定性的影响。     

疏水-亲脂作用对反应活性的影响

本文在t-BuOH-H₂O,Me₂SO-H₂O等六种有机溶剂-水二元体系中用动力学方法研究了:(1)疏水-亲脂作用对不同链长的脂肪酸酯 —C₇H₁₅,—C₁₁H₂₃,—C₁₅H₃₁)水解行为的影响;(2)竣甲基糖淀粉(Na-CMA)催化酯水解机理的探讨;(3)长链酯簇集与其被糖淀粉包结之间的竞争;(4)疏水取代基常数的反应活性之间相关分析的新探索。     

Reactions of Lewis bases with tetrakisdiphenylamide uranium(IV)

The coordinatively unsaturated uranium(IV) complex U[N(C₆H₅)₂]₄ has been prepared via the stoichiometric reaction of diphenylamine with [(Me₃Si)₂N]₂ H₂. U[N(C₆H₅)₂]₄ coordinates Lewis bases such as Et₂O, THF, pyridine or (EtO)₃PO, based on electronic absorption spectroscopy and ¹H NMR studies. Exchange between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄(L), where L is THF or pyridine, is rapid on the NMR time-scale between 307 and 323 K. Measurement of equilibrium constants for L = THF provides ΔH and ΔS values of −60 kJ mol⁻¹ and −1.8 × 10² J K⁻¹ mol⁻¹, respectively. U[N(C₆H₅)₂]₄ coordinates and binds (EtO)₃PO much more tightly (K_eq = & > 10⁴ M⁻¹) than THF or pyridine with the exchange rate between U[N(C₆H₅)₂]₄ and U[N(C₆H₅)₂]₄[OP(OEt)₃] being close to the NMR time-scale.     

Synthese und reaktivität von dienylmetall-verbindungen : XXVII. Ein einfacher weg zur synthese von cyclopentadienylcobalt(III)-dikationen

CpCo(CO)₂ is oxidised by [Cp₂Fe]BF₄ (Cp = C₅H₅) in the presence of neutral ligands L to give the dications [CpCoL₃]²⁺ (L = SMe₂, S(n-C₄H₉)₂, PMe₃, C₅H₅N, MeCN; Me = CH₃). In [CpCo(SMe₂)₃]²⁺, sulfane ligands are substituted by neutral ligands L, L---L and L---L---L, to give the complexes [CpCoL₃]²⁺ (L = SeMe₂, TeMe₂, PMe₃, P(OMe)₃, AsMe₃, SbMe₃, t-C₄H₉NC, C₅H₅N, MeCN), [Cp-Co(L---L)SMe₂]²⁺ (L---L = R₂P(CH₂)_nPR₂, n = 1, 2, R = C₆H₅; bipyridine, o-phenanthroline, neocuproin) and [CpCo(L---L---L)]²⁺ (L---L---L = RP(CH₂CH₂PR₂)₂, R = C₆H₅). The dications react with iodide resulting in the monocations [CpCoL₂I]⁺ and [CpCo(L---L)I]⁺. Azacobaltocinium cations [CpCo(C₄R₂H₂N)]⁺ (R = H, CH₃) are obtained by reaction of [CpCo(SMe₂)₃]²⁺ with metal pyrrolides.     

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.     

The synthesis and lyotropic phase behaviour of some aquatetra(cyano)-dodecylaminoferrate(II) complexes

Some alkali and alkaline earth metal salts of the amphiphilic anion [Fe(CN)₄(H₂O)(C₁₂H₂₅NH₂)]^2- have been synthesized by reaction of [Fe(CN)₅NO]^3- with C₁₂H₂₅NH₂. Using optical microscopy, they have been shown to give a hexagonal (H₁) mesophase in water.     

Isospecific polymerizations of alkyl methacrylates with a bis(alkyl)Yb complex and formation of stereocomplexes with syndiotactic poly(alkyl methacrylate)s

Yb[C(SiMe₃)₃]₂ initiates the living polymerization of methyl methacrylate (MMA) at −78°C to give the polymer with M_n of 51.0×10⁴ (M_w/M_n=1.1) and high isotacticity (97%) in a quantitative yield. Mixing of the acetone solution of resulting polymer (M_n=16.3×10⁴) with the acetone solution of syndiotactic poly(MMA) (M_n=15.7×10⁴) prepared by the (C₅Me₅)₂SmMe(THF) initiator produces desired stereocomplex in high yield bearing very high T_m whose tensile modulus is higher than the respective isotactic and syndiotactic poly(MMA)s. Yb[C(SiMe₃)₃]₂ also generated isotactic (98%) poly[2-(dimethylamino)ethyl methacrylate] (DMEMA), and (C₅Me₅)₂SmMe(THF) affords the syndiotactic (97%) polymer in high yields. The combination of isotactic poly(MMA)-block-poly(DMEMA) (97/3) and syndiotactic poly(MMA)-block-poly(DMEMA) (97/3) provides the amphiphathic stereocomplex. In sharp contrast to the catalysis of Yb[C(SiMe₃)₃]₂ in toluene, the addition of THF or HMPA resulted in the formation of syndio-rich poly(MMA).     

Interaction of heterocyclic thioamides with tellurium(II) and tellurium(IV). Syntheses and crystal structures of bis[2-(2-thioxo-1,3- thiazolidin-3-yl)-4,5-dihydro-1,3- thiazolium]hexabromotellurate(IV) and tris(1- methylimidazole-2-(3H)-thione)tellurium(II) bromide

Reaction of 1,3-thiazolidine-2-thione with tellurium(IV) in hydrobromic acid medium gave the hexabromotellurate, [C₆H₉N₂S₃]₂²⁺[Te^IVBr₆]²⁻ (3). Reaction of 1-methylimidazoline-2-(3H)-thione (L″) with tellurium(IV), in hydrobromic acid medium, gave the mixed-ligand tellurium(II) complex [Te^IIL″₃Br]⁺Br⁻ (4). The structures of [C₆H₉N₂S₃]₂²⁺[Te^IVBr₆]²⁻ (3) and [Te^IIL″₃Br]⁺Br⁻ were determined by single crystal X-ray diffraction methods. In 3 the unit cell contains [TeBr₆]²⁻ anions and two [C₆H₉N₂S₃]⁺ cations. There is no direct bonding between the metal atom and the cations. In the anion only slight angular deviations from the perfect octahedral geometry are observed. The lone pair of electrons on tellurium(IV) is found to be stereochemically inert. In the cation the two five-membered heterocyclic rings adopt different conformations. In complex 4, in the solid state, the planar [Te^IIL″₃Br]⁺ cation and Br⁻ anion are held together by ionic interactions. In the cation, L″ is bonded to the central tellurium atom through the sulphur atom.     

Group 3 and 4 metal alkyl and hydrido complexes containing a linked amido-cyclopentadienyl ligand: “constrained geometry” polymerization catalysts for nonpolar and polar monomers

In order to understand the nature of the putative cationic 12-electron species [M(η⁵:η¹-C₅R₄SiMe₂NR′)R″]⁺ of titanium catalysts supported by a linked amido-cyclopentadienyl ligand, several derivatives with different cyclopentadienyl C₅R₄ and amido substituents R′ were studied systematically. The use of tridentate variants (C₅R₄SiMe₂NCH₂CH₂X)²⁻ (C₅R₄=C₅Me₄, C₅H₄, C₅H₃^tBu; X=OMe, SMe, NMe₂) allowed the NMR spectroscopic observation of the titanium benzyl cations [Ti(η⁵:η¹-C₅Me₄SiMe₂NCH₂CH₂X)(CH₂Ph)]⁺. Isoelectronic neutral rare earth metal complexes [Ln(η⁵:η¹-C₅R₄SiMe₂NR′)R″] can be expected to be active for polymerization. To arrive at neutral 12-electron hydride and alkyl species of the rare earth metals, we employed a lanthanide tris(alkyl) complex [Ln(CH₂SiMe₃)₃(THF)₂] (Ln=Y, Lu, Yb, Er, Tb), which allows the facile synthesis of the linked amido-cyclopentadienyl complex [Ln(η⁵:η¹-C₅Me₄SiMe₂NCMe₃)(CH₂SiMe₃)(THF)]. Hydrogenolysis of the linked amido-cyclopentadienyl alkyl complex leads to the dimeric hydrido complex [Ln(η⁵:η¹-C₅Me₄SiMe₂NCMe₃)(THF)(μ-H)]₂. These complexes are single-site, single-component catalysts for the polymerization of ethylene and a variety of polar monomers such as acrylates and acrylonitrile. Nonpolar monomers such as -olefins and styrene, in contrast, give isolable mono-insertion products which allow detailed studies of the initiation process.     

Thermal decomposition study on mixed ligand thymine complexes of divalent nickel(II) with dianions of some dicarboxylic acids

Thermal decomposition of mixed ligand thymine (2,4-dihydroxy-5-methylpyrimidine) complexes of divalent Ni(II) with aspartate, glutamate and ADA (N-2-acetamido)iminodiacetate dianions was monitored by TG, DTG and DTA analysis in static atmosphere of air. The decomposition course and steps of complexes [Ni(C₅H₆N₂O₂)(C₄H₅NO₄)²⁻(H₂O)₂]·H₂O, [Ni(C₅H₆N₂O₂)(C₅H₇NO₄)²⁻(H₂O)₂]·H₂O and [Ni(C₅H₆N₂O₂)(C₆H₈N₂O₅)²⁻(H₂O)₂]·1.5H₂O were analyzed. The final decomposition products are found to be the corresponding metal oxides. The kinetic parameters namely, activation energy (E*), enthalpy (ΔH*), entropy (ΔS*) and free energy change of decomposition (ΔG*) are calculated from the TG curves using Coats–Redfern and Horowitz–Metzger equations. The stability order found for these complexes follows the trend aspartate > ADA > glutamate.     

Synthesis and X-ray crystal structures of [Ph2PMe2][(η-C5H4Bu)2Li] and [(η-C5H4Bu)2Yb(Cl)CH2P(Me)Ph2]

The interaction of [(η⁵-C₅H₄Bu^t)₂YbCl · LiCl] with one equivalent of Li[(CH₂) (CH₂)PPh₂] in tetrahydrofuran gave [Ph₂PMe₂][(η⁵-C₅H₄Bu^t)₂Li] (1) and [(η⁵-C₅H₄Bu^t)₂Yb(Cl)CH₂P(Me)Ph₂] (2) in 10% and 30% yields, respectively. 1 could also be prepared in 70% yield from the reaction of [Ph₂PMe₂][CF₃SO₃] with two equivalents of (C₅H₄Bu^t)Li. Both compounds have been fully characterized by analytical, spectroscopic and X-ray diffraction methods. The solid state structure of 1 reveals a sandwich structure for the [(η⁵-C₅H₄Bu^t)₂Li]⁻ anion.     

Metallorganische verbindungen der lanthanoide LVIII. Zur struktur des dicyclopentadienyl-bis(trimethylsilyl)lutetat-anions

(C₅H₅)₂Lu(μ-Cl₂)Na(dme)₂ reacts with LiSi(CH₃)₃ in dimethoxyethane with formation of [Li(dme)₃][(C₅H₅)₂Lu(Si(CH₃)₃)₂]. The crystal structure study shows the compound to consist of discrete ions [Li(dme)₃]⁺ and [(C₅H₅)₂Lu(Si(CH₃)₃)₂]⁻. The compound crystallizes in the space group P2/n with a 14.497(5) b 9.041(2), c 14.672(6) Å, β 103.85(3)° and V 1867(2) ų. The crystal and molecular structure was refined to R = 0.0473 for 2491 observed reflections with F_o 3σ(F_o).