三(环戊基茚基)钐配合物(C5H9C9H6)3SmCl-Li+(THF)4的合成与晶体结构

稀土配合物能使极性和非极性单体聚合[1].虽然目前已测定了几乎所有的三(环戊二烯基)稀土配合物及部分三(取代环戊二烯基)稀土配合物的晶体结构, 但有关三(茚基)稀土配合物的报道较少. 第一个三(茚基)稀土配合物是无水三氯化稀土与3倍物质的量的茚基钠C9H7Na在四氢呋喃中反应而得, 但未报道其晶体结构 [2]. 后来用同样的反应却分离出以氯为桥的二聚体离子对配合物 [Na(THF)6] [Ln(η5-C9H7)3μ(Cl)Ln(η5-C9H7)3](Ln=Nd, Sm) [3]. 无水三氯化稀土与Mg(C9H7)2或C9H7K等物质的量反应则生成非溶剂化的(C9H7)3Sm[4], 而与茚基钠和环辛四烯钾(C8H8K)以1∶2∶1物质的量比反应时, 则得到(C9H7)3Ln(THF)(Ln=Nd, Gd) [5]. Bottomley [6]曾用(C9Me7)K(七甲基茚基钾)与LnCl3(物质的量比3∶1)反应制备(C9Me7)3Nd(THF)5和(C9Me7)3Er@(THF)3, 但未报道晶体结构. 因为取代茚的空间阻碍比茚的大, 三(取代茚基)稀土配合物较难合成. 迄今未见有关单晶结构报道. 本文首次报道三(环戊基茚基)钐配合物的合成及晶体结构.     

[（t—BuCp）2GdCl]2的合成及晶体结构

Wayda最近报道,无水氯化稀土LnCl_3和叔丁基环戊二烯钠(t-BuCp)Na进行交换反应时,由于歧化反应得不到单取代或双取代的轻稀土氯化物衍生物,只能得到中稀土和重稀土氯化物衍生物,并且没有测得这些配合物的晶体结构。我们采用提高反应温度和延长反应时间,使交换反应进行完全,有效地避免了歧化反应的发生,成功地分离到了单取代或双取代的叔丁基环戊二烯基轻稀土氯化物。并测得(t-BuCp)_2LnCl·nTHF(Ln=Pr,n=2;Ln=Yb,n=1)     

稀土硼氢化物研究——ⅩⅡ.含[B_(12)H_(12)]~(2-)、[B_(10)H_(10)]~(2-)及[B_(10)H_9NH_2COC_3H_7]~-的联吡啶氮氧化物稀土配合物

稀土十二氢十二硼酸与2,2′-联吡啶-N,N′-二氧化物反应,或稀土氯化物与2,2′-联吡啶N,N′-二氧化物及十硼十氢双四乙基铵或Et_4NB_(10)H_9NH_2COC_3H_7反应,制取八个新型稀土配合物。经元素分析、红外光谱、紫外光谱、摩尔电导测定及X射线衍射分析对配合物进行了表征。结果表明,2,2′-联吡啶N,N′-二氧化物以两个氧原子与稀土螯合。含[B_(10)H_9NH_2COC_3H_7]~-配合物中,它通过羰基氧与稀土配位。配合物热稳定次序为:[B_(12)H_(12)]~(2-)>[B_(10)H_9NH_2COC_3H_7]~->[B_(10)H_(10)]~(2-)配合物。     

三（环戊基茚基）钐配合物（C5H9C9H6）3SmCl^—Li^＋（THF）4的合成与晶体结构

稀土配合物能使极性和非极性单体聚合[1] .虽然目前已测定了几乎所有的三 (环戊二烯基 )稀土配合物及部分三 (取代环戊二烯基 )稀土配合物的晶体结构 ,但有关三 (茚基 )稀土配合物的报道较少 .第一个三 (茚基 )稀土配合物是无水三氯化稀土与 3倍物质的量的茚基钠 C9H7Na在四氢呋喃中反应而得 ,但未报道其晶体结构[2 ] .后来用同样的反应却分离出以氯为桥的二聚体离子对配合物[Na( THF) 6][Ln( η5- C9H7) 3μ( Cl) Ln( η5- C9H7) 3]( Ln=Nd,Sm) [3] .无水三氯化稀土与 Mg( C9H7) 2 或C9H7K等物质的量反应则生成非溶剂化的 ( C9H7…     

含P—H键螺环五配位磷化合物的加成反应

5-氢-1,9-二氧-4,6-二氮-5-膦环-[4,4]壬烷1与二硫化碳、异硫氰酸酯反应,分别得到2-巯基二氢噻唑2和2-取代氨基二氢噻唑4,并用动态~(31)P NMR谱研究了其反应机理。     

1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮的合成新方法

发展了一条1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮的新合成方法,以价廉、易得的对溴苯酚为原料,在无水碳酸钾作用下与2-溴乙醛缩二乙醇缩合后用多聚磷酸(PPA)环合得5-溴苯并呋喃,该中间体与丙烯酸甲酯在Pd(OAc)2催化下,经Heck偶合反应得3-(苯并呋喃-5-基)丙酸甲酯,在氢氧化钠水溶液中经Raney Ni催化氢化和水解一锅反应得3-(2,3-二氢苯并呋喃-5-基)丙酸,再经二溴代、Friedel-Crafts酰化反应和氢解脱溴,得1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮,7步反应总收率49.9%.该方法原料易得、反应条件温和、操作简便、产物分离纯化容易,收率良好,适合大规模制备1,2,6,7-四氢-8H-茚并[5,4-b]呋喃-8-酮.     

磺酰胺为烷基化试剂高选择性合成多取代烯烃和2,3-二氢茚衍生物的方法

在质子酸H_2SO_4催化下,含β氢醇与磺酰胺反应可高选择性地得到三取代烯烃和2,3-二氢茚衍生物.含β氢醇酸性条件下脱水后与磺酰胺发生偶联,可以选择性地合成热力学稳定产物Z-多取代烯烃;两者发生[3+2]环加成反应,则可高选择性地得到2,3-二氢茚衍生物.     

二(环戊二烯基)氯化镨和二茚基稀土氯化物的合成

二(环戊二烯基)氯化镨的合成已知的二(环戊二烯基)稀土氯化物(C_5H_5)_2LnCl(Ln=Sm～Lu)均为重稀土化合物.曾有人试图合成二(环戊二烯基)轻稀土(Ln=La～Nd)氯化物但未获成功,认为是由于镧系收缩和轻稀土配位的不饱和性.然而,用取代环戊二烯基和茚基或含螯合物为配位体却可以合成轻稀土的化合物.我们采用 NdCl_3·2THF 和环戊二烯钠在 THF 溶液中室温下反应制得了(C_5H_5)_2NdCl·THF.它具有二聚体的结构,属单斜晶系,空间群为 P2_1/c,该化合物在抽空加热下脱 THF,得到组成符合(C_5H_5)_2NdCl 的残余物.     

(R)-N-(β-三氯锗丙酰基)四氢噻唑-2-硫酮-4-羧酸甲酯的合成及其晶体结构

三氯锗丙酰氯与(R)-四氢噻唑-2-硫酮-4-羧酸甲酯反应, 得到标题化合物1, [α]~D^2^0-89.40°。经水解得到取代丙酰四氢噻唑-2-硫酮-4-羧酸甲酯基锗倍半氧化物2, X射线衍射法测出标题化合物的晶体结构, 属于正交晶系, 晶胞参数: a=0.6192(1)nm,b=1.1147(4)nm,c=2.1796(8)nm, V=1.5045nm^3, Z=4, 空间群P2~12~12~1。分子中酰胺羰基C=O与C=S基团处于C(4)NC(3)键两侧呈反式。用MNDO分子轨道方法研究了该化合物的电子结构, 电荷和键序分布,前沿轨道性质,讨论了电子光谱性质。     

(R)-N-(β-三氯锗丙酰基)四氢噻唑-2-硫酮-4-羧酸甲酯的合成及其晶体结构

三氯锗丙酰氯与(R)-四氢噻唑-2-硫酮-4-羧酸甲酯反应, 得到标题化合物1, [α]~D^2^0-89.40°。经水解得到取代丙酰四氢噻唑-2-硫酮-4-羧酸甲酯基锗倍半氧化物2, X射线衍射法测出标题化合物的晶体结构, 属于正交晶系, 晶胞参数: a=0.6192(1)nm,b=1.1147(4)nm,c=2.1796(8)nm, V=1.5045nm^3, Z=4, 空间群P2~12~12~1。分子中酰胺羰基C=O与C=S基团处于C(4)NC(3)键两侧呈反式。用MNDO分子轨道方法研究了该化合物的电子结构, 电荷和键序分布,前沿轨道性质,讨论了电子光谱性质。     

d/f-Polypnictides Derived by Non-Classical Ln2+ Compounds: Synthesis,Small Molecule Activation and Optical Properties

Reduction chemistry induced by divalent lanthanides has been primarily focused on samarium so far. In light of the rich physical properties of the lanthanides, this limitation to one element is a drawback. Since molecular divalent compounds of almost all lanthanides have been available for some time, we used one known and two new non-classical reducing agents of the early lanthanides to establish a sophisticated reduction chemistry. As a result, six new d/f-polyphosphides or d/f-polyarsenides, [K(18-crown-6)] [Cp′′₂Ln(E₅)FeCp*] (Ln=La, Ce, Nd; E=P, As) were obtained. Their reactivity was studied by activation of P₄, resulting in a selective expansion of the P₅ rings. The obtained compounds [K(18-crown-6)] [Cp′′₂Ln(P₇)FeCp*] (Ln=La, Nd) are the first examples of an activation of P₄ by a f-element-polypnictide complex. Additionally, the first systematic femtosecond (fs)-spectroscopy investigations of d/f-polypnictides are presented to showcase the advantages of having access to a broader series of lanthanide compounds.     

Synthesis and properties of lanthanide(III) complexes with 4-hydroxy-3,5-dimethoxybenzoic acid

Complexes of yttrium(III) and lanthanides(III) with 4-hydroxy-3,5-dimethoxybenzoic (syringic) acid were obtained as solids with metal to ligand mole ratio of 1: 3. The compounds were characterized by elemental analysis, IR spectroscopy, X-ray diffraction patterns, solubility, and thermal studies. The complexes are sparingly soluble in water and stable at room temperature. Compounds of light lanthanides (from La to Nd) are hydrated and they crystallize in a triclinic system. When heated, they lose water molecules in one step and in the next step they decompose to oxides. Complexes of yttrium and other lanthanides are anhydrous and crystallize in a monoclinic system. They are stable up to 300°C and then decompose to oxides. As the coordination number of lanthanide ions is usually equal to 9 or 8, one can suppose that hydroxy or methoxy groups take part in the coordination of these metal ions.     

Pillaring of CdCl2-like layers in lanthanide metal-organic frameworks: synthesis, structure, and photophysical properties

A hydrothermal reaction of lanthanide salts, pyridine-2,3-dicarboxylic acid, benzene-1,4-dicarboxylic acid, and water gave rise to a new series of three-dimensional mixed carboxylates (homocyclic and heterocyclic) of lanthanides with the general formula [M2(H2O)4][{C5H3N(COO)2}2{C6H4(COO)2}], M=La (I), Pr (II), and Nd (III). The structure consists of M2O14N2 dimeric units connected by pyridine-2,3-dicarboxylate moieties to form two-dimensional layers that are pillared by terephthalate units. The structures also possess two co-ordinated water molecules, which are arranged to form one-dimensional helical chains and can be reversibly adsorbed. The connectivity within the layers closely resembles that of the CdCl2 layered structure with 3(6) topology. To the best of our knowledge, this is the first observation of CdCl2 topology in lanthanide metal-organic framework compounds. Partial substitution of La3+ in I by Eu3+ and Tb3+ (2 and 4 %) gives rise to characteristic red/pink or green emission, which suggests a ligand-sensitized metal-centered emission. The Nd compound III shows interesting UV and blue emission through an up-conversion process.     

(CH~3OCH~2CH~2C~5H~4)~2Ln(C~5H~5)的合成和反应性能

本文通过双(2-甲氧乙基环戊二烯基)稀土氯化物与环戊二烯基钠在室温下反应, 经升华得新配合物,(CH~3OCH~2CH~2C~5H~4)~2Ln(C~5H~5) (Ln=La,Pr,Nd), 这些配合物都经红外、光电子能谱、质谱、核磁共振谱和元素分析鉴定；并且比较了具有不同配位环境的三茂稀土配合物－氢化钠体系还原1－己烯的活性。     

POLYMER-SUPPORTED LANTHANIDE COMPLEXES FOR THE POLYMERIZATION OF BUTADIENE

The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1, 4 polybutadiene attained was more than 98%.     

Comparison of thermal properties of lanthanide trimellitates prepared by different methods

By diffusion in gel medium new complexes of formulae: Nd(btc)⋅6H₂O, Gd(btc)⋅4.5H₂O and Er(btc)·5H2O (where btc=(C₆H₃(COO)₃ ³⁻) were obtained. Isomorphous compounds were crystallized in the form of globules. During heating in air atmosphere they lose stepwise water molecules and then anhydrous complexes decompose to oxides. Hydrothermally synthesized polycrystalline lanthanide trimellitates form two groups of isomorphous compounds. The light lanthanides form very stable compounds of the formula Ln(btc)⋅nH₂O (where Ln=Ce−Gd and n=0 for Ce; n=1 for Gd; n=1.5 for La, Pr, Nd; n=2 for Eu, Sm). They dehydrate above 250°C and then immediately decomposition process occurs. Heavy lanthanides form complexes of formula Ln(btc)⋅nH₂O (_Ln=Dy−Lu). For mostly complexes, dehydration occurs in one step forming stable in wide range temperature compounds. As the final products of thermal decomposition lanthanide oxides are formed.     

Pentavalent Lanthanide Compounds: Formation and Characterization of Praseodymium(V) Oxides

The chemistry of lanthanides (Ln=La–Lu) is dominated by the low‐valent +3 or +2 oxidation state because of the chemical inertness of the valence 4f electrons. The highest known oxidation state of the whole lanthanide series is +4 for Ce, Pr, Nd, Tb, and Dy. We report the formation of the lanthanide oxide species PrO₄ and PrO₂⁺ complexes in the gas phase and in a solid noble‐gas matrix. Combined infrared spectroscopic and advanced quantum chemistry studies show that these species have the unprecedented Pr^V oxidation state, thus demonstrating that the pentavalent state is viable for lanthanide elements in a suitable coordination environment.     

New luminescent solids in the Ln-W(Mo)-Te-O-(Cl) systems

Solid-state reactions of lanthanide(III) oxide (and/or lanthanide(III) oxychloride), MoO3 (or WO3), and TeO2 at high temperature lead to eight new luminescent compounds with four different types of structures, namely, Ln2(MoO4)(Te4O10) (Ln = Pr, Nd), La2(WO4)(Te3O7)2, Nd2W2Te2O13, and Ln5(MO4)(Te5O13)(TeO3)2Cl3 (Ln = Pr, Nd; M = Mo, W). The structures of Ln2(MoO4)(Te4O10) (Ln = Pr, Nd) feature a 3D network in which the MoO4 tetrahedra serve as bridges between two lanthanide(III) tellurite layers. La2(WO4)(Te3O7)2 features a triple-layer structure built of a [La2WO4]4+ layer sandwiched between two Te3O72- anionic layers. The structure of Nd2W2Te2O13 is a 3D network in which the W2O108- dimers were inserted in the large tunnels of the neodymium(III) tellurites. The structures of Ln5(MO4)(Te5O13)(TeO3)2Cl3 (Ln = Pr, Nd; M = Mo, W) feature a 3D network structure built of lanthanide(III) ions interconnected by bridging TeO32-, Te5O136-, and Cl- anions with the MO4 (M = Mo, W) tetrahedra capping on both sides of the Ln4 (Ln = Pr, Nd) clusters and the isolated Cl- anions occupying the large apertures of the structure. Luminescent studies indicate that Pr2(MoO4)(Te4O10) and Pr5(MO4)(Te5O13)(TeO3)2Cl3 (M = Mo, W) are able to emit blue, green, and red light, whereas Nd2(MoO4)(Te4O10), Nd2W2Te2O13, and Nd5(MO4)(Te5O13)(TeO3)2Cl3 (M = Mo, W) exhibit strong emission bands in the near-IR region.     

Lanthanide Crownphthalocyaninates: Synthesis,Structure, and Peculiarities of Formation

Complexing properties of lanthanide ions with respect to crown-substituted phthalocyanine are analyzed. Complexes of lanthanides (La, Nd, Sm, Eu, Gd, Tb, Yb, Lu, Y) with tetra-15-crown-5-phthalocyanine are synthesized and their structures are studied by photoelectronic, IR, ¹H NMR, and mass spectrometry methods.     

Evidence of different stoichiometries for the limiting carbonate complexes across the lanthanide(III) series: a capillary electrophoresis-mass spectrometry study

The electrophoretic mobilities (mu ep,Ln) of twelve lanthanides (not Ce, Pr and Yb) were measured by CE-ICP-MS in 0.15 and 0.5 mol L(-1) Alk2 CO3 aqueous solutions for Alk+ = Li+, Na+, K+ and Cs+. In 0.5 mol L(-1) solutions, two different mu ep,Ln values were found for the light (La to Nd) and the heavy (Dy to Tm) lanthanides, which suggests two different stoichiometries for the carbonate limiting complexes. These results are consistent with a solubility study that attests the Ln(CO3)3(3-) and Ln(CO3)4(5-) stoichiometries for the heavy (small) and the light (big) lanthanides, respectively. The Alk+ counterions influence the mu ep,Ln Alk2 CO3 values, but not the overall shape of the mu ep,Ln Alk2 CO3 plots as a function of the lanthanide atomic numbers: the counterions do not modify the stoichiometries of the inner sphere complexes. The influence of the Alk+ counterions decreases in the Li+ > Na+ > K+ > Cs+ series. The K3,Ln stepwise formation constants of the Ln(CO3)3(3-) complexes slightly increase with the atomic numbers of the lanthanides while K4,Ln, the stepwise formation constants of Ln(CO3)4(5-) complexes, slightly decrease from La to Tb, and is no longer measurable for heavier lanthanides.