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1.
1 INTRODUCTIONAsatypeofimportanceprecursor,alotoforganolanthanidechloridecomplexeshavebeensynthesizedandstructurallycharacterized[1].Thebimetalliccomplexescontainingalkalimetal,Cp2Ln(μCl)2M(L)(Cp=η5C5H5orC5Me5;M=Li,Na;L=THF,TMEDA),isamainstructuretype.Inthecourseo…  相似文献   

2.
王为清  刘景福 《电化学》1995,1(4):422-426
应用电化学,系统研究Keggin结构稀土取代衍生物Ln(MW11)2(M=As,Ti,Ga,Ln=La,Ce,Pr,Nd,Sm,EU,Gd,Dy)在溶液中的氧化还原性质,得其氧化顺序,提出还原机理。  相似文献   

3.
应用电化学方法,系统研究keggin结构稀土取代衍生物Ln(MW_(11)_2(M=As,Ti,Ga,Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Dy)在溶液中的氧化还原性质,得其氧化顺序,提出还原机理。  相似文献   

4.
在严格的无水无氧条件下无水NdCl3和SmCl3与Na2(C5H4SiMe2)2O以1:1摩尔比在四氢呋叶溶液中反应,得标题配合物(O(Me2SiC5H4)2Ln(μ-Cl)(THF)2(Ln=Nd(1),Sm(2),元素分析证明配合物1和2的组成,X射线衍射分析证明1和2是通过氯原子桥联的二聚体结构。  相似文献   

5.
Ln(acac)3—BuMgCl催化甲基丙烯酸甲酯聚合   总被引:2,自引:0,他引:2  
开发了催化甲基丙烯酸甲酯聚合的一类新型催化剂,由稀土乙酰基丙酮配合物Ln(acac)3和格氏试剂BuMgCl组成.研究了不同稀土元素、催化剂陈化时间和温度、溶剂、CCl4添加剂、聚合时间和温度的影响.结果表明,在石油醚中单体聚合转化率和聚合物相对分子质量高于芳烃和其它极性溶剂,过量BuMgCl可能起链转移作用,降低温度可提高聚合物的间同含量.  相似文献   

6.
无水三氯化稀土(LnCl3),二(三甲硅基)胺基钾(LiN(SiMe3)2〗及1-(2-甲乙基)茚室温上在四氢呋喃溶剂中反应,得到了4个含1-(2-甲氧乙基)茚基和二(三甲硅基)胺基的稀土金属有机物{(C9H6CH2C2OMe)Ln〖N(SiMe3)2〗2(Ln=Nd,Sm,Dy,Yb)},这些配合物均经元素分析、IR和MS表征。  相似文献   

7.
Ln(acac)_3/BuMgCl催化聚合甲基丙烯酸甲酯、环氧丙烷和ε-己内酯孙俊全(浙江大学高分子科学与工程系杭州310027)关键词甲基丙烯酸甲酯,环氧丙烷,ε-己内酯,稀土化合物,格氏试剂,配位催化剂,聚合反应在开拓稀土配位聚合反应的研究中,已?..  相似文献   

8.
1 INTRODUCTIONSince1980,manyV/Fe/Sheterometallicsulfurclustercompoundshavebeenreported.RauchfussetalobtainedtwokindsofV/Fe/Scompounds[1]using(CH3C5H4)2V2S4asanorganometallicligand,oneis(MeCp)2V2Fe2(NO)2S4withacubanelikestructureandanotheris(MeCp)2V2S4Fe(NO)2and(MeCp)2V2S4…  相似文献   

9.
Kaminsky型催化剂化乙烯齐聚:二酚基二茂锆的催化作用   总被引:6,自引:0,他引:6  
王梅  沈玉梅 《分子催化》1999,13(4):282-286
通过改变Al/Zr比,反应温度及反应时间,分别考察了Cp2Zr(OAr)2/EAO(Ar=C6H5、p-C6H4Me、M-c6h4no2、P-c6h4no2)4种体系对乙烯齐聚的催化作用,发现用Cp2Zr(OAr)2代替Cp2ZrCl2作为主催化剂,对于Kaminsky型体系Cp2ZrL2/EAO催化乙烯齐聚,具有调变作用,在提高催化活性的同时,可使低碳烯烃的造反  相似文献   

10.
陈久桐  郭国聪 《结构化学》1996,15(3):231-234
通过(1)LnOCl/V_2O_5,(2)LnCl3/V及(3)LnOCl/LnCl/V_2O_5/V的高温固态化学反应,得到两种稀土钒酸盐:Ln_6V_3Cl_(10)O_(12)(Ln=La)及Ln_4V_5Si_4O_(22)(Ln=La~Nd)。La_6V_3O_(10)O_(12)晶体呈浅色透明片状,其结构可认为是由[La_3(VO_4)_3Cl]单元插入到LaCl3结构单元中而形成的,在结构中沿c轴方向存在一系列截面积为19.1的空洞。Ln_4V_5Si_4O_(22)(Ln=La,Ce,Pr,Nd)晶体呈,黑色针状,其结构可认为是由交替的稀土钒硅酸盐薄层及钒氧金红石层沿c轴堆叠而表现为准二维Chevkinite型结构。  相似文献   

11.
Rare-earth silylamide complexes, Ln[N(SiMe3)2]3 (Ln = Y, La, Sm, Yb), effectively catalyzed the coupling reaction of isocyanides with both aliphatic and aromatic terminal alkynes under mild conditions.  相似文献   

12.
The protonolysis reaction of heterobimetallic peralkylated complexes [Ln(AlR4)2]n (Ln=Sm, Yb; R=Me, Et) with 2 equiv of HOC 6H 2 tBu 2-2,6-Me-4 affords the bis(trialkylaluminum) adducts Ln[(micro-OArtBu,Me)(micro-R)AlR2]2 in good yields. Analogous reactions with the less sterically demanding iPr-substituted phenol result in ligand redistributions and formation of X-ray structurally evidenced Ln[(micro-OAriPr,H) 2AlR2]2 (Ln=Yb, R=Me; Ln=Sm, R=Et), Yb[(micro-OAriPr,H)(micro-Et)AlEt2]2(THF), and [Et2Al(micro-OAriPr,H) 2Yb(micro-Et)2AlEt2]2. The solid-state structures of serendipitous alumoxane complex Sm[(micro-OArtBu,Me)AlEt2OAlEt2(micro-OArtBu,Me)](toluene) and dimeric AlMe 3-adduct complex [(AlMe3)(micro-OArtBu,Me)Sm(micro-OArtBu,Me) 2Sm(micro-OArtBu,Me)(AlMe3)] were also determined by X-ray crystallography. While the former can be discussed as a typical hydrolysis product of Sm[(micro-OArtBu,Me)(micro-Et)AlEt2]2, the latter was isolated from the 1:1 reaction of [Sm(AlEt4)2]n with HOArtBu,Me.  相似文献   

13.
In this paper, we report the first examples of trispyrazolylmethane complexes of rare earths. Reaction of LnCl3 with Tpm* (tris(3,5-dimethylpyrazolyl)methane) in THF or acetonitrile gives good yields of the [Ln(Tpm*)Cl3] (Ln = Y, Ce, Nd, Sm, Gd, Yb). Tpm* adducts of the lanthanide triflates [Ln(Tpm*)(OTf)3(THF)] (Ln = Y, Ho, Dy) may also be prepared. The X-ray crystal structures of [Y(Tpm*)Cl3], [Sm(Tpm*)Cl3(THF)], and [Ln(Tpm*)(OTf)3(THF)] (Ln = Y, Ho) are reported. The halide/triflate complexes may be used to prepare the aryloxide complexes [Ln(Tpm*)(OArMe2)3] (Ln = Y, Nd, Sm, Yb; ArMe2 = C6H3-2,6-(CH3)2), which are fluxional in solution as a result of interactions between the Tpm* and the aryloxide groups. The structures of the Nd and Sm complexes have been determined. Finally, the reaction of [Nd(BH4)3(THF)3] with Tpm* in THF results in the displacement of two THF molecules to give [Nd(Tpm*)(BH4)3(THF)]. Infrared spectra are consistent with tridentate borohydride coordination. The X-ray structures of these compounds indicate that the Tpm* ligand is less strongly bound than its anionic trispyrazolylborate analogues.  相似文献   

14.
Reaction of LnI2 (Ln = Sm, Yb) with two equivalents of NaTp(Me2) or reduction of Eu(Tp(Me2))2OTf gives good yields of the highly insoluble homoleptic Ln(II) complexes, Ln(Tp(Me2))2 (Ln = Sm (1a), Yb (2a), Eu (3a)). Use of the additionally 4-ethyl substituted Tp(Me2,4Et) ligand produces the analogous, but soluble Ln(Tp(Me2,4Et))2 (1-3b) complexes. Soluble compounds are also obtained with the Tp(Ph) and Tp(Tn) ligands (Tn = thienyl), Ln(Tp(Ph))2 (Ln = Sm, 1c; Yb, 2c) and Ln(Tp(Tn))2 (Ln = Sm, 1d; Yb, 2d). To provide benchmark parameters for structural comparison the series of Sm(Tp(Me2))2X complexes (X = F, 1e; Cl, 1f; Br, 1g; I, 1h; BPh4, 1j) were prepared either via oxidation of the Sm(Tp(Me2))2 or salt metathesis from SmX3 (X = Cl, Br, I). The solid-state structures of 1-3a, 1b, 1-2c and 1e, 1f, 1h, and 1j were determined by single-crystal X-ray diffraction. The homoleptic bis-Tp complexes are all six-coordinate with trigonal antiprismatic geometries, planes of the kappa(3)-Tp ligands are parallel to one another. In the series of Sm(Tp(Me2))2X complexes the structure changes from seven-coordinate molecular compounds, with intact Sm-X bonds, for X = F, Cl, to six-coordinate ionic structures [Sm(Tp(Me2))2]X (X = I, BPh4), suitable crystals of the bromide compound could not be obtained. The dependence of the structures on the size of X is understandable in terms of the interplay between the size of the cleft that the [Sm(Tp(Me2))2](+) fragment can make available and the donor ability of the anionic group toward the hard Sm(III) center.  相似文献   

15.
[Ln[N(SiMe3)2]2(THF)2](Ln = Sm, Yb) reacts with 1 equiv. of carbon-bridged biphenols, 2,2'-methylene-bis(6-tert-butyl-4-methylphenol)(L1H2) or 2,2'-ethylidene-bis(4,6-di-tert-butylphenol)(L2H2), in toluene to give the novel aryloxide lanthanide(II) complexes [[LnL1(THF)n]2](Ln = Sm, n = 3 (1); Ln = Yb, n = 2 (2)) and [[LnL2(THF)3]2](Ln = Sm (5); Ln = Yb (6)) in quantitative yield, respectively. Addition of 2 equiv. of hexamethylphosphoric triamide (HMPA) to a tetrahydrofuran (THF) solution of 1, 2 and 5 affords the corresponding HMPA-coordinated complexes, [[LnL1(THF)m(HMPA)n]2(THF)y](Ln = Sm, n = 2, m = 0, y = 2 (3); Ln = Yb, m = 1, n = 1, y = 6 (4)) and [[SmL2(HMPA)2]2](7) in excellent yields. The single-crystal structural analyses of 3, 4 and 7 revealed that these aryloxide lanthanide(II) complexes are dimeric with two Ln-O bridges. The coordination geometry of each lanthanide metal can be best described as a distorted trigonal bipyramid. Complexes 1-3, 5 and 7 can catalyze the ring-opening polymerization of epsilon-caprolactone (epsilon-CL), and 1-3, along with 5 show moderate activity for the ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) and the copolymerization of epsilon-CL and DTC to give random copolymers with high molecular weights and relatively narrow molecular weight distributions..  相似文献   

16.
The heterobimetallic peralkylated complexes [Ln(AlR4)2]n (Ln = Sm, Yb; R = Me, Et) were synthesized by a silylamide elimination route from Ln[N(SiMe3)2]2(THF)2 and an excess of AlR3. The solid-state structure of [Sm(AlEt4)2]n is isomorphous to that of the ytterbium derivative. Polymeric [Yb(AlMe4)2]n was examined by 1H and 13C MAS NMR spectroscopy revealing the presence of distinct bridging methyl groups. The reaction of [Yb(AlMe4)2]n and 1,10-phenanthroline (Phen) afforded the monomeric donor adduct Yb(AlMe4)2(Phen), while the protonolysis reaction with 2 equiv. C5Me5H (HCp*) yielded a separated ion pair of composition [Cp*Yb(THF)(4)][AlMe(4)]. Single-crystal X-ray diffraction data are provided for both ytterbium(II) complexes. Solid-state magnetic measurements (SQUID) were performed on [Sm(AlMe4)2]n, [Sm(AlEt4)2]n, SmI2(THF)2 and Sm[N(SiMe3)2]2(THF)2 showing high effective magnetic moments 3.67micro(B) < micro(eff) < 4.43micro(B).  相似文献   

17.
Wang Q  Xiang L  Song H  Zi G 《Inorganic chemistry》2008,47(10):4319-4328
A new series of amidolanthanides have been prepared from the reactions between Ln[N(SiMe3)2]3 and the chiral NNO ligands, (S)-2-(pyrrol-2-ylmethyleneamino)-2'-hydroxy-6,6'-dimethyl-1,1'-biphenyl (2H2) and (S)-5,5',6,6',7,7',8,8'-octahydro-2-(pyrrol-2-ylmethyleneamino)-2'-hydroxy-1,1'-binaphthyl (3H2), which are synthesized from the condensation of pyrrole-2-carboxaldehyde with 1 equiv of (S)-2-amino-2'-hydroxy-6,6'-dimethyl-1,1'-biphenyl or (S)-5,5',6,6',7,7',8,8'-octahydro-2-amino-2'-hydroxy-1,1'-binaphthyl, in the presence of molecular sieves at 70 degrees C, respectively. Treatment of 2H2 with 1 equiv of Ln[N(SiMe3)2]3 (Ln=Sm, Yb) in toluene under reflux, followed by recrystallization from a toluene solution, gives the dimeric amido complexes, {2-SmN(SiMe3)2}2.0.5C7H8 (6.0.5C7H8) and {2-YbN(SiMe3)2} 2.1.5C7H8(8.1.5C7H8), in good yields. While under similar reaction conditions, the reaction of 2H2 with 1 equiv of Y[N(SiMe3)2]3 leads to the isolation of a mixture of {2-YN(SiMe3)2}2 (7a) and {(2)2Y}Y[N(SiMe3)2]2(7b) in 82% total yield; the reaction of 3H2 with 1 equiv of Ln[N(SiMe3)2]3 (Ln=Y, Yb) gives the trinuclear complexes, {(3)2Ln}2LnN(SiMe3) 2.1.5C7H8 (Ln=Y(9.1.5C7H8), Yb(10.1.5C7H8)), in good yields. All compounds have been characterized by various spectroscopic techniques and elemental analyses. The solid-state structures of compounds 2H2 and 6- 10 have been further confirmed by X-ray diffraction analyses. Complexes 6- 9 are active catalysts for the asymmetric hydroamination/cyclization of aminoalkenes, affording cyclic amines in good yields with moderate ee values.  相似文献   

18.
Reactions of a range of the readily prepared and sterically tunable N,N'-bis(aryl)formamidines with lanthanoid metals and bis(pentafluorophenyl)mercury (Hg(C6F5)2) in THF have given an extensive series of tris(formamidinato)lanthanoid(III) complexes, [Ln(Form)3(thf)n], namely [La(o-TolForm)3(thf)2], [Er(o-TolForm)3(thf)], [La(XylForm)3(thf)], [Sm(XylForm)3], [Ln(MesForm)3] (Ln=La, Nd, Sm and Yb), [Ln(EtForm)3] (Ln=La, Nd, Sm, Ho and Yb), and [Ln(o-PhPhForm)3] (Ln=La, Nd, Sm and Er). [For an explanation of the N,N'-bis(aryl)formamidinate abbreviations used see Scheme 1.] Analogous attempts to prepare [Yb(o-TolForm)3] by this method invariably yielded [{Yb(o-TolForm)2(mu-OH)(thf)}2], but [Yb(o-TolForm)3] was isolated from a metathesis synthesis. X-ray crystal structures show exclusively N,N'-chelation of the Form ligands and a gradation in coordination number with Ln3+ size and with Form ligand bulk. The largest ligands, MesForm, EtForm and o-PhPhForm give solely homoleptic complexes, the first two being six-coordinate, the last having an eta1-pi-Ar--Ln interaction. Reaction of lanthanoid elements and Hg(C6F5)2 with the still bulkier DippFormH in THF resulted in C--F activation and formation of [Ln(DippForm)2F(thf)] (Ln=La, Ce, Nd, Sm and Tm) complexes, and o-HC6F4O(CH2)4DippForm in which the formamidine is functionalised by a ring-opened THF that has trapped tetrafluorobenzyne. Analogous reactions between Ln metals, Hg(o-HC6F4)2 and DippFormH yielded [Ln(DippForm)2F(thf)] (Ln=La, Sm and Nd) and 3,4,5-F3C6H2O(CH2)4DippForm. X-ray crystal structures of the heteroleptic fluorides show six-coordinate monomers with two chelating DippForm ligands and cisoid fluoride and THF ligands in a trigonal prismatic array. The organometallic species [Ln(DippForm)2(C[triple chemical bond]CPh)(thf)] (Ln=Nd or Sm) are obtained from reaction of Nd metal, bis(phenylethynyl)mercury (Hg(C[triple chemical bond]CPh)2) and DippFormH, and the oxidation of [Sm(DippForm)2(thf)2] with Hg(C[triple chemical bond]CPh)2, respectively. The monomeric, six-coordinate, cisoid [Ln(DippForm)2(C[triple chemical bond]CPh)(thf)] complexes have trigonal prismatic geometries and rare (for Ln) terminal C[triple chemical bond]CPh groups with contrasting Ln--C[triple chemical bond]C angles (Ln=Nd, 170.9(4) degrees; Ln=Sm, 142.9(7) degrees). Their formation lends support to the view that [Ln(DippForm)2F(thf)] complexes arise from oxidative formation and C--F activation of [Ln(DippForm)2(C6F5)] intermediates.  相似文献   

19.
磷酸二丁酯稀土络合物的合成与红外光谱研究   总被引:3,自引:3,他引:3  
李来明  马爱增 《分析化学》1991,19(9):987-992
  相似文献   

20.
Synthesis of a new class of compounds containing a Ln-O-Al moiety has been accomplished by the reaction of LAlOH(Me) (L = HC(CMeNAr)(2), Ar = 2,6-iPr(2)C(6)H(3)) with a series of Cp(3)Ln compounds. The terminal Al-OH group shows selective reactivity, and the complexes Cp(2)Ln(THF)-O-AlL(Me) (Ln = Yb, 1; Er, 2; Dy, 3), Cp(2)Yb-O-AlL(Me) (4), and Cp(3)Ln(mu-OH)AlL(Me) (Ln = Er, 5; Dy, 6; Sm, 7) were obtained. This allows further insight into the proton exchange process, and two different mechanisms, intermolecular and intramolecular elimination of CpH, are proposed under different conditions. Complexes 1-4, 6, and 7 have been characterized by X-ray structural analyses which reveals a Ln-O-Al or Ln(mu-OH)Al core in these complexes. The obtuse Ln-O-Al angles fall in the range 151.9-169.8 degrees . The reaction of 1 or 4 with Me(3)SnF in toluene under refluxing conditions unexpectedly yielded the compounds [Cp(2)Yb(mu-OSnMe(3))](2) (8) and LAl(Me)F (9). Reactions of LAlOH(Me) with the mono- and dicyclopentadienyl complexes LYbCp(Cl) (10) and LYbCp(2) (11) supported by the bulky beta-diketiminate ligand were unsuccessful. However, the reaction of LAl(OH)Me with LYbN(SiMe(3))(2)Cl (12) containing a labile Yb-N bond leads to the formation of LYbCl-O-AlL(Me) (13) under elimination of HN(SiMe(3))(2). Furthermore, complexes 1, 3, 4, and 6 exhibit good catalytic activity for the polymerization of epsilon-caprolactone.  相似文献   

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