Molecular Ln(III)−H−E(II) Linkages (Ln=Y,Lu; E=Ge,Sn, Pb)

Following the alkane-elimination route, the reaction between tetravalent aryl tintrihydride Ar*SnH₃ and trivalent rare-earth-metallocene alkyls [Cp*₂Ln(CH{SiMe₃}₂)] gave complexes [Cp*₂Ln(μ-H)₂SnAr*] implementing a low-valent tin hydride (Ln=Y, Lu; Ar*=2,6-Trip₂C₆H₃, Trip=2,4,6-triisopropylphenyl). The homologous complexes of germanium and lead, [Cp*₂Ln(μ-H)₂EAr*] (E = Ge, Pb), were accessed via addition of low-valent [(Ar*EH)₂] to the rare-earth-metal hydrides [(Cp*₂LnH)₂]. The lead compounds [Cp*₂Ln(μ-H)₂PbAr*] exhibit H/D exchange in reactions with deuterated solvents or dihydrogen.     

系列Ln(Ⅲ)配位聚合物(Ln=Eu,Sm,Tb,Pr,Gd)的合成及其荧光分析

采用水热法合成了4个具有1D结构的Ln(Ⅲ)配位聚合物,[Eu₂(C₉H₇O₂)₆(C₉H₇O₂H)(C₂H₅OH)]n(1)、[Sm(C₉H₇O₂)₃]n(2)、[Tb(C₉H₇O₂)₃]n(3)和[Gd(C₉H₇O₂)₃]n(4)(C₉H₈O₂=肉桂酸)。 通过X射线单晶衍射确定了它们的结构。 这4个Ln(Ⅲ)配合物中,Ln(Ⅲ)的配位数均为9,桥配体均为肉桂酸根,但其配位方式有差异。 对配合物进行了IR、UV-Vis-NIR和荧光光谱等表征。 分析了各配合物的荧光发射,结果表明,在可见区,配合物1发射较明显的红光,配合物2、3发射绿光,配合物4发射蓝光,但很弱。 讨论了具有刚柔相混杂性质的肉桂酸配体对配位聚合物的构筑及稀土离子发光的影响。     

Hydrothermal Synthesis,Crystal Structures,and Fluorescence Properties of Ni(II)–Ln(III) Complexes (Ln = Sm,Pr, Eu)

Three novel 3d–4f heterometal complexes [Ln(NiL)₃(Btca)(NO₃)] · xH₂O (Ln = Sm(III) (I), Pr(III) (II), Eu(III) (III) (H₂L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien, H₂Btca = benzotriazole-5-carboxylic acid) were solvothermally synthesized and characterized by singlecrystal X-ray diffraction (CIF files CCDC nos. 1555557 (I), 1555555 (II), 1555556 (III)). They crystallized in the monoclinic space group P2₁/n for I (x = 1.5) and C2/c for (II) and (III) (x = 1), respectively. In these complexes, the central Ln(III) and external nickel ions are bridged by macrocyclic oxamide groups. The metal center of Ln(III) resides in a distorted bicapped square antiprism surrounding with six oxygen atoms of three oxamide groups, two oxygen atoms of Btca^2– ion and two oxygen atoms of NO₃^-. Furthermore, there are C–H···O and/or C–H···N hydrogen bond interactions among nitrate, benzotriazole-5-carboxylate, macrocyclic oxamide and water to form three-dimensional superamolecular architecture. The fluorescence properties of the compounds I and II are also discussed.     

三元体系Ln(ClO~4)~3-ACAP-H~2O(Ln=La,Sm,Yb)的相平衡研究(30℃)

测定了三元体系Ln(ClO~4)~3-ACAP-H~2O(Ln=La,Sm,Yb, ACAP=4-乙酰安替比林)在30℃时的溶解度及饱和溶液的折光率,绘制了相应的溶度图和饱和溶液的折光率-组成图.体系的溶度曲线和折光率曲线均由三支组成,分别与ACAP,Ln(ACAP)~3(ClO~4)~3·nH~2O(Ln=La,n=4,Sm,2,Yb,2)和Ln(ClO~4)~3·nH~2O(Ln=La,n=8,Sm,9,Yb,8)相对应.从溶度图上发现了三个未见文献报道的三元化合物, 它们均为固液异组成溶解的化合物.通过化学分析,元素分析,TG-DTG,IR,UV和X射线粉末衍射进行了表征.初步探讨了影响安替比林4位酰代衍生物β-二酮配体配位能力的因素     

Syntheses of (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, Er, Yb) and crystal structure of [(C_5H_9C_5H_4)_2-LnCl(THF)_n]_2(Ln=Sm, n=1; Ln=Er, n=0)

Reactions of lanthanoid trichlorides with sodium cyclopentylcyclopentadienyl in THFafford bis(cyclopentylcyclopentadienyl) lanthanoid chloride complexes (C_5H_9C_5H_4)_2LnCl(THF)_n (Ln=Nd, Sm, n=1; Ln= Er, Yb, n= 0). The compound [CP'_2SmCl(THF)]_2 (2) (Cp' =cyclopentylcy-clopentadienyl) crystallizes from mixed solvent of hexane and THF in monoclinic space group P_2_1/cwith a = 11.583 (3), b = 23.019(6), c = 8.227 (2), β= 90.26 (2)°, V= 2194 (1)~3, D_c= 1.59 g/cm~3.μ= 28.6 cm~(-1), F(000) = 1060, Z= 2 (dimers). Its crystal molecule is a dimer with a crystallographicsymmetry center. The central metal atom Sm is coordinated to two Cp' rings, two bridging chlorineatoms and one THF forming a distorted trigonal bipyramid. The crystal of [Cp'_2ErCl]_2 (3) belongs tothe triclinic space group P with a = 11.264 (2), b= 13.296(5), c = 14.296(6), a = 96.99 (3), β=112.47(2), γ= 102.78(2)°, V= 1865(1)~3, D_c= 1.67 g /cm~3, μ= 48.0 cm~(-1), F(000) = 924, Z = 2 (dimers).The molecule is a dimer consisting of two Cp'_2 ErCl species bridged by two Cl atoms. The centralmetal atom Er is coordinated to two Cp' rings and two bridging chlorine atoms forming a pseudo-tetrahedron. All these complexes are soluble in THF, DME, Et_2O, toluene and hexane.     

水热法制备近红外发光NaLa(WO4)2∶Ln(Ln=Er, Nd)球形粒子的研究

利用水热法制备了NaLa（WO4）2∶Ln（Ln=Er,Nd）球形粉末,分别用XRD,TEM和发光光谱等对粉末的物相、形貌、发光性质进行研究。XRD和SEM结果表明：制得的NaLa（WO4）2∶Ln（Ln=Er,Nd）粉末为白钨矿晶型,分散性良好,粒度均匀,呈规则的球形,粒径为1μm左右。发光光谱的测试表明：样品的最佳掺杂浓度为1.0%;随着煅烧温度的增加,样品发光强度逐渐增大;700℃下煅烧时最佳煅烧时间是4 h。     

Synthesis, structures, and photoluminescence of heteroligand complexes Ln(L)(iso-Bu2PS2)2(NO3) (Ln = Sm, Tb, Dy; L = Phen, 2,2′-Bipy)

Heteroligand complexes Ln(L)(iso-Bu₂PS₂)₂(NO₃) (Ln = Sm, Tb, Dy; L = Phen, 2,2??-Bipy) (I?CVI) are synthesized. The structure of Dy(Phen)(iso-Bu₂PS₂)₂(NO₃) (III) is determined from the data of X-ray structure analysis. The crystal structure of complex III is based on discrete mononuclear molecules in which the Dy atom has distorted dodecahedral coordination (polyhedron N₂O₂S₄). The ligands Phen, iso-Bu₂PS ₂ ^? and NO ₃ ^? are bidentate-cyclic. According to the X-ray diffraction analysis data, complexes I and II are isostructural to compound III. Complexes I?CVI have photoluminescence in the visible spectral range. The photoluminescence spectra of solid samples of compounds I?CVI exhibit bands corresponding to the radiative electron transitions of the Sm³⁺, Tb³⁺, and Dy³⁺ ions. Among the studied compounds I?CVI, the Tb(III) complexes are characterized by the most intense photoluminescence.     

Structural Order–Disorder Transitions in Ln2Ti2O7 (Ln = Lu,Gd)

The phase generation in the Lu(Gd)–Ti–O systems is studied at 20–1000° using a co-precipitation method. During a thermal treatment of co-precipitation products after a sublimation dehydration, for a composition with the Lu : Ti cation ratio of 1 : 1, an Lu₂Ti₂O₇ phase with a fluorite structure forms at 650°. At 730–750°C the phase undergoes a fluorite pyrochlore transition. Above 750°C its structure is that of disordered pyrochlore, in which antistructural defects occur in Lu and Ti positions (up to 18%). Above 900°C the structure of pyrochlore becomes ordered, and the number of defects in Lu and Ti positions decreases, which affects the temperature dependence of permittivity of Lu₂Ti₂O₇. In Gd–Ti–O system, Gd₂Ti₂O₇ is crystallized, which has a pyrochlore structure only at 740–900°. Electroconductivity and permittivity of Lu₂Ti₂O₇ and Gd₂Ti₂O₇ are measured.     

Synthesis and structural characterization of lanthanide oxalate–oxydiacetate mixed-ligand coordination polymers {[Ln(oda)(H2O) x ]2(ox)} n ( x = 3 for Ln = La,Ce, Pr,Gd, Tb and x = 2 for Ln = Er)

Reactions of oxydiacetic acid (H₂oda) with lanthanide oxide, nitrate, chloride, and carbonate gave six lanthanide oxalate–oxydiacetate mixed-ligand coordination polymers {[Ln(oda)(H₂O) _x ]₂(ox)} _n [x = 3 for Ln = La, Ce, Pr, Gd, Tb, (1–5), and x = 2 for Ln = Er (6)]. Oxydiacetic acid is decomposed into oxalic acid in this reaction. In the crystal structures of 1–6, oxydiacetate and the lanthanides build a chain, and the oxalate groups bridge two chains to form 1-D double-chain ladder-shaped structures, connected by intermolecular hydrogen bonds to form a 2-D network structure. These compounds contain approximately 3.0 × 6.4 Ų channels along the c-axis. The infrared spectra and thermal behaviors of 1–6 are also investigated.     

[(dbm)3Ln(dmbipy)](Ln=Eu,Tb,Ho,Tm,Yb)的合成、结构和荧光性质

以二苯甲酰甲烷和4,4'-二甲基-2,2'-联吡啶为配体合成了一类单核稀土配合物[(dbm)_3Ln(dmbipy)](Ln=Eu(1)、Tb(2)、Ho(3)、Tm(4)和Yb(5))(Hdbm~-=二苯甲酰甲烷,dmbipy=4,4'-二甲基-2,2'-联吡啶)。单晶X-射线衍射分析表明五例配合物为同构,结晶于单斜晶系,P2_1/n空间群。配合物由3个dbm~-配体和1个dmbipy配体构成,中心Ln~(3+)离子位于四方反棱柱构型中。荧光测试表明,配合物1和2在可见光区出现了Eu~(3+)和Tb~(3+)离子的一系列特征发射峰,配合物3,4和5在近红外光区分别表现出Ho~(3+),Tm~(3+)和Yb~(3+)离子的特征发射峰。     

Oxidation resistance of LnSiON powders (Ln=Y,Gd and La)

For application of LnSiON (Ln=Y, Gd and La) oxynitride materials, e.g. as host-lattices for lamp phosphors, oxidation resistance up to about 600 °C in air is a prerequisite. In this study we prepared LnSiON (Ln=Y, Gd and La) powders by solid state reaction and observed via TGA/DTA-experiments that most compounds are oxidation resistant up to 600 °C in air. The stability in air at high temperatures increases going from Ln₅(SiO₄)₃N, Ln₄Si₂O₇N₂, LnSiO₂N, Ln₂Si₃O₃N₄ to Ln₃Si₈O₄N₁₁. This is explained by an increasing cross-linking between the siliconoxygennitrogen tetrahedra in this sequence. For the lattices with less cross-linking between the siliconoxygennitrogen tetrahedra we observed that the oxidation resistance decreases slightly going from Y and Gd to La. For these lattices, also, an additional weight gain was observed during the oxidation reaction, which was higher than expected for complete oxidation. The additional weight gain was ascribed to an intermediate phase in which nitrogen retention takes place.     

ELECTRONIC STRUCTURE AND CHEMICAL BONDING OF BIS(TRIMETHYLSILYL)AMIDE DERIVATIVES OF LANTHANIDES(Ln(N(SiMe_3)_2)_3, Ln=Nd, Eu, Yb)

The electronic structure and chemical bonding of Ln(N(SiMe_3)_2)_3 have been studied by INDO calcula-tions. The results have shown that the Ln-N bonds are considerably covalent in character and that thecovalency decreases with increasing atomic numbers. A new explanation of the pyramidal structure of thecompounds has been proposed based on 5d orbital participation in bonding. With the calculation of asimplified model of Eu(N(SiMe_3)_2)_3. OPPh_3, the roles of electronic and steric effects in bonding have beencompared.     

三元体系Ln(ClO4)3-4-ClCH2COAp-H2O(30℃)的相平衡研究(Ln=La,Sm,Er)

我们测定了三元体系Ln(ClO4)3-4-ClCh2COAp-H2O(Ln=La,Er)在30℃时的溶度及饱和溶液的折光指数,绘制相应的溶度图和饱和溶液的折光指数曲线图。体系的溶度曲线和折光指数曲线均由四支组成,分别与4-ClCh2COAp、Ln(4-ClCh2COAp)3·nH2O(Ln=La,n=7;Sm,8;Er,4)、Ln(4-ClCH2COAp)2(ClO4)3·nH2O(Ln-La,n=7;Sr,6;Er,4)和Ln(ClO4)3·nH2O(Ln=La,n=8;Sm,9;Er,6)相对应,两类配合物均为固液异组成化合物。     

BaCe0.8Ln0.2O2.9(Ln=Gd, Sm, Eu)固体电解质的低温制备及其燃料电池性质

利用溶胶 凝胶法低温合成了BaCe0 .8Ln0 .2 O2 .9(Ln =Gd ,Sm ,Eu)固体电解质 ,X射线粉末衍射表明 90 0℃即形成正交钙钛矿结构 ,较高温固相反应合成温度降低了约 6 0 0℃ .测定了样品的阻抗谱和电导率 ,研究了其导电机理 ,溶胶 凝胶法合成可减小或消除固体电解质的晶界电阻 ,80 0℃时BaCe0 .8Gd0 .2 O2 .9的σ =7.87× 10 -2S·cm-1,以它为电解质的氢氧燃料电池开路电压接近 1V ,最大输出功率密度为 30mW·cm-2 .     

(CH_3C_5H_4)_3Ln·THF(Ln=Sm,Ho,Tb,Yb)与环戊二烯生成(C_5H_5)_3Ln·THF的新反应

研究了(CH_3C_5H_4)_3Ln·THF (Ln = Sm,Ho,Tb,Yb)与环戊二烯高产率生成 (C_5H_5)_3Ln·THF的新反应。反应产物经过了元素分析、质谱和X射线的表征。产 物(C_5H_5)_3Ln·THF的特征结构参数,如五元碳环的碳原子与中心金属的平均距 离,五元碳环质心与中心金属距离,配位的四氢呋喃氧原子与中心金属距离,由于 “镧系收缩现象”,随着中心原子序数的增加而减小。     

三元体系Ln(ClO4)3-4-ClCH2COAp-H2O(30℃)的相平衡研究(Ln=La,Sm,Er)

我们测定了三元体系 Ln(ClO_4)_3—4-ClCH_2COA_p—H_2O(Ln=La,Sm,Er)存30℃时的溶度及饱和溶液的折光指数,绘制了相应的溶度图和饱和溶液的折光指数曲线图.体系的溶度曲线和折光指数曲线均由四支组成,分别与4-ClCH_2COA_p、Ln(4-ClCH_2COAp)_3(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,8;Er,4)、Ln(4-ClCH_2COAp)_2(ClO_4)_3·nH_2O(Ln=La,n=7;Sm,6;Er,4)和 Ln(ClO_4)_3·nH_2O(Ln=La,n=8;Sm,9;Er,6)相对应,两类配合物均为固液异组成化合物.     

镧系元素双三甲基硅胺基络合物(Ln(N(SiMe_3)_2)_3,Ln=Nd,Eu,Yb)的电子结构和化学键

本文采用自旋不限制的INDO方法,首次研究了Ln(N(SiMe_3)_2)_3络合物(Ln=Nd,Eu,Yb)的电子结构和化学键。结果表明,金属和配位体之间的化学键具有很强的共价性,共价性随原子序数增加而减弱。根据5d轨道成键对络合物奇特的三角锥结构提出了新的解释。计算了双三甲基硅胺基铕的OPPh_3加合物的电子结构,并讨论了电子结构和位阻效应在配位化学中的作用。     

The magnetochemistry of novel cyano-bridged complexes Ln(DMF)4(H2O)2Mn(CN)6 · H2O (Ln = Tb,Dy, Er)

Using K₃Mn(CN)₆, DMF and Ln(NO₃)₃ · 6H₂O (Ln = Tb, Dy or Er), novel cyano-bridged complexes Ln(DMF)₄(H₂O)₂Mn(CN)₆ · H₂O (TbMn, DyMn and ErMn, respectively) were prepared and their magnetochemical properties were studied in detail. A weak antiferromagnetic interaction was found to exist between the rare earth ions and the manganese ion. Er(DMF)₄(H₂O)₂Mn(CN)₆ · H₂O, in particular, exhibits long-range magnetic ordering, a higher critical temperature (T _c = 17.5 K) and a stronger coercive force (H _c = 980 Oe).     

Stabilization Of The CN35− Anion In Recoverable High-pressure Ln3O2(CN3) (Ln=La,Eu, Gd,Tb, Ho,Yb) Oxoguanidinates

A series of isostructural Ln₃O₂(CN₃) (Ln=La, Eu, Gd, Tb, Ho, Yb) oxoguanidinates was synthesized under high-pressure (25–54 GPa) high-temperature (2000–3000 K) conditions in laser-heated diamond anvil cells. The crystal structure of this novel class of compounds was determined via synchrotron single-crystal X-ray diffraction (SCXRD) as well as corroborated by X-ray absorption near edge structure (XANES) measurements and density functional theory (DFT) calculations. The Ln₃O₂(CN₃) solids are composed of the hitherto unknown CN₃⁵⁻ guanidinate anion—deprotonated guanidine. Changes in unit cell volumes and compressibility of Ln₃O₂(CN₃) (Ln=La, Eu, Gd, Tb, Ho, Yb) compounds are found to be dictated by the lanthanide contraction phenomenon. Decompression experiments show that Ln₃O₂(CN₃) compounds are recoverable to ambient conditions. The stabilization of the CN₃⁵⁻ guanidinate anion at ambient conditions provides new opportunities in inorganic and organic synthetic chemistry.