Ln2Cl 7 − ions (Ln = La and Lu): Structures and thermodynamic stability

The equilibrium geometrical parameters and frequencies of the normal vibrations of Ln₂Cl ₇ ^? ions (Ln = La and Lu) and the enthalpies of the dissociation reactions Ln₂Cl ₇ ^? → Ln₂Cl₆ + Cl^? and Ln₂Cl ₇ ^? → LnCl₃ + LnCl ₄ ^? were calculated at the MP2 and MP4 levels (with regard to single, double, triple, and quadruple perturbations). The basis set superposition errors were eliminated by using the counterpoise approach. The potential energy surface of the Ln₂Cl ₇ ^? ions was found to reach a minimum for a configuration with three bridging and four terminal Cl atoms (symmetry C ₂). The terminal fragments LnCl₂ show almost free inherent rotation. The lanthanide compression of the interatomic Ln-Cl distances differed for the bridging and terminal Ln-Cl bonds. The calculated enthalpies of dissociation of the Ln₂Cl ₇ ^? ions were compared with data from high-temperature mass spectrometry.     

Ce3+在LnOX(Ln=La,Gd或Y;X=Cl,Br或I)中的发光

以激发光谱和发光光谱研究了Ce³⁺在LnOX中的发光。光谱表明当X相同而Ln不同时,谱图上Ce³⁺峰的位置只有较小的移动;而X不同时Ce³⁺峰的位置有明显和有规律地移动,即按照Cl——Br——I次序往长波方向移动,这个次序与X的电负性减小的次序是一致的。还可以看到Ln=La时与Ln=Gd或Y时有差别,而且Ln=La时stokes位移较大,从离子半径角度对这些进行了讨论。     

Thermodynamic properties of some lanthanum and lanthanide halides: II. Thermodynamic functions of gaseous molecules LnX (Ln = Ce−Lu,X = F,Cl)

The molecular constants of LnF (Ln = Ce?Lu) for the ground state have been estimated based on the available spectroscopic characteristics of lanthanum and lanthanide monofluorides. These constants have been used for calculating the reduced Gibbs energy (?[G ⁰(T) ? H ⁰(0)]/T) of the compounds in the ideal gas state in the range 298.15–3000 K at the standard pressure p ⁰ = 0.1 MPa. The rigid rotator-harmonic oscillator approximation with additional inclusion of the anharmonicity of oscillations (by the method of Mayer and Goeppert-Mayer) and correction for centrifugal stretching have been used. The contribution made by electronic excitation has been calculated by two methods: based on the energies of the excited states of molecules and based on the electronic excitation energy of the free Ln⁺ ion. Analogous data are reported for lanthanide monochlorides.     

(η^5-C~5H~5)~3Ln.OC~4H~8(Ln=Ce,Er)的合成及晶体结构

用无水硝酸铈铵[(NH~4)~2Ce(NO~3)~6]与环戊二烯钠(C~5H~5Na)在四氢呋喃中1:6摩尔比反应, 得到(η^5-C~5H~5)~3Ce.OC~4H~8; 用ErCl~3.nTHF与环辛二烯钾(C~8H~11K)按等摩尔比于-78℃反应, 升至室温, 再按1:2摩尔比加入C~5H~5Na, 得到了(η^5-C~5H~5)~3Er.OC~4H~8。两配合物晶体结构测定结果表明都属单斜晶系P2~1/n空间群。Ce配合物与已测定过的(η^5-C~5H~5)~3Ln.OC~4H~8(Ln=La, Pr,Nd, Gd, Dy, Y, Lu)的晶体结构不是同构物; 而Er配合则是同构物。Ce配合物中的Ce-O、Ce-Cent(环戊二烯环中心)和平均Ce-C(η^5)键长不符合镧系收缩规律, 而Er配合物的键长符合。这说明在(η^5-C~5H~5)~3Ln.OC~4H~8同构系列中的Ce和Dy有两个断点, 但不存在所谓的“钆断现象”, 因为Y, Er, Lu配合物的Ln-O和Ln-C(η^5)和Ln-Centroid距离不大于Gd的相应值。     

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     

Ce~(3+)在LnOX(Ln=La,Gd或Y;X=Cl,Br或I)中的发光

以激发光谱和发光光谱研究了Ce~(3+)在LnOX中的发光。光谱表明当X相同而Ln不同时,谱图上Ce~(3+)峰的位置只有较小的移动;而X不同时Ce~(3+)峰的位置有明显和有规律地移动,即按照Cl——Br——I次序往长波方向移动,这个次序与X的电负性减小的次序是一致的。还可以看到Ln=La时与Ln=Gd或Y时有差别,而且Ln=La时stokes位移较大,从离子半径角度对这些进行了讨论。     

(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(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。     

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.     

Syntheses and Single-crystal Structures of Ln_3Sn_(0.25)GeS_7 (Ln=La,Sm)

Two new quaternary sulfides,La3Sn0.25GeS71 and Sm3 Sn0.25GeS72,have been synthesized by a facile solid-state reaction,and their crystal structures were determined by singlecrystal X-ray diffraction analysis.The two compounds crystallize in the P6 3 space group,and the crystal data are as follows-La3Sn0.25GeS7:a=10.3335(7),c=5.8455(7),Z=2;Sm3Sn0.25GeS7:a=9.999(3),c=5.787(2),Z=2.Single-crystal analysis indicated that the two compounds consist of three types of building blocks:LnS 8 anti-tetragonal prism,SnS 6 octahedron,and GeS 4 tetrahedron.     

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.     

Syntheses and characterization of [Ru(η5-C5H5) (AsPh3)(L)X] and [Ru(η5-C5H5)(AsPh3)(L)(MeCN)]+mY− (L = PPh3 or AsPh3; X = F,Cl, Br,I, CN,H or SnCl3; Y = HgCl3, Zn2Cl6 or BPh4; m = 1 or 2)

The syntheses of the complexes [(η⁵-C₅H₅)Ru(AsPh₃)(L)X] (L = PPh₃ or AsPh₃; X = Cl, F, Br, I, H, CN or SnCl₃) and [(η⁵-C₅H₅)Ru(AsPh₃)(L)(MeCN)]⁺Y⁻ (Y = HgCl₃, BPh₄ or Zn₂Cl₆) are described. They were characterized by elemental analyses, IR, UV and visible, PMR spectroscopy, X-ray powder diffraction, and mass spectral studies.     

Syntheses and Structures of Alkali Metal Rare Earth Polyphosphates CsLn（PO3）4 （Ln = La,Ce）

Alkali metal-rare earth polyphosphates, CsLn（PO3）4 （Ln = La, Ce）, were synthesized by the high temperature solution reaction and studied by single-crystal X-ray diffraction technique. They crystallize in the monoclinic space group P21 （Z = 2） and feature infinite PO4 spiral chains linked with neighboring CsO10 and LnO8 polyhedra. In addition, theoretically calculated energy band structure and density of states （DOS） by the density functional theory （DFT） predict that the solid-state compound CsLa（PO3）4 possesses insulative character.     

A series of heterobimetallic Ni(II)–Ln(III) (Ln = La,Ce, Pr and Nd) coordination polymers derived from 3-EtOsalamo and dicarboxylates: syntheses,crystal structures and fluorescence properties

Transition Metal Chemistry - Four coordination polymers ∞2 [Ni(DMF)(L)Ln(bdc)1.5] (Ln?=?La (1) and Nd (4)) and ∞2 [Ni2(DMF)2(L)2Ln2(bdc)3]·CH3OH (Ln?=?Ce...     

Oxygen-Bridged Ga2(Et)3(OTeF5)3 and the Weakly Coordinating Anions [Ga(Et)(OTeF5)3]− and [Ga(OTeF5)4]−

Salts of the weakly coordinating anions [Ga(OTeF₅)₄]⁻ as well as [Ga(Et)(OTeF₅)₃]⁻ and the neutral Ga₂(Et)₃(OTeF₅)₃ were synthesized and characterized by spectroscopic methods and single-crystal X-ray diffraction. Ga₂(Et)₃(OTeF₅)₃ was formed by treating GaEt₃ with pentafluoroorthotelluric acid (HOTeF₅) and reacted with PPh₄Cl and CPh₃Cl to [PPh₄][Ga(Et)(OTeF₅)₃] and [CPh₃][Ga(Et)(OTeF₅)₃]. In contrast, Ag[Ga(OTeF₅)₄] was prepared from AgOTeF₅ and GaCl₃ and was used as a versatile starting material for further reactions. Starting with Ag[Ga(OTeF₅)₄] the substrates [PPh₄][Ga(OTeF₅)₄] and [CPh₃][Ga(OTeF₅)₄] were formed from PPh₄Cl and CPh₃Cl.     

Synthesis and structures of the six-coordinate donor-acceptor complexes R3(C6H4O2)Sb…L (R=Ph, L=OSMe2 or ONC5H5; R=Me, L=ONC5H5 or NC5H5) and R3(C2H4O2)Sb…L (R=Ph, L=ONC5H5; R=Cl or C6F5, L=OPPh3)

One-pot oxidation of R₃Sb (R=Ph, Me, Cl, or C₆F₅) withtert-butyl hydroperoxide in the presence of 1,2-diols and monodentate donor compounds was studied. The structures of the resulting neutral organic donor-acceptor Sb^V complexes, Ph₃(C₆H₄O₂)Sb…OSMe₂, Ph₃(C₆H₄O₂)Sb…ONC₅H₅, Me₃(C₆H₄O₂)Sb…ONC₅H₅, Me₃(C₆H₄O₂)Sb…NC₅H₅, Ph₃(C₂H₄O₂)Sb…ONC₅H₅, and Cl(C₆F₅)₂(C₂H₄O₂)Sb…OPPh₃, were established by X-ray diffraction analysis. In these complexes, the coordination environment about the Sb atoms is a distorted octahedron. The Sb?O(N) distances and the Sb?O?E angles (E=S, N, or P) vary over wide ranges.     

Ln(NO_3)_3·C_(26)H_(38)N_2O_4(Ln=La、Ce)配合物的合成和La(NO_3)_3·C_(26)H_(38)N_2O_4·CH_3CN的晶体结构

合成了２个新的希土冠醚配合物Ｌｎ（ＮＯ３）３·Ｃ２６Ｈ３８Ｎ２Ｏ４（Ｌｎ＝Ｌａ、Ｃｅ；Ｃ２６Ｈ３８Ｎ２Ｏ４＝１，７，１０，１６－四氧－４，１３－二氮杂－Ｎ，Ｎ′－二苄基环十八烷）。通过元素分析，红外光谱，拉曼光谱及其１Ｈ核磁共振谱进行表征。用四圆衍射仪测定了Ｌａ（ＮＯ３）３·Ｃ２６Ｈ３８Ｎ２Ｏ４·ＣＨ３ＣＮ的晶体结构。晶体属三斜晶系，Ｐ１空间群，晶胞参数：ａ＝１．２８６９（４）ｎｍ，ｂ＝１．５８６８（６）ｎｍ，ｃ＝０．９１４７（２）ｎｍ；α＝１０１．８９（２）°，β＝１０５．３８（２）°，γ＝７１．９６（３）°；Ｚ＝２。ｄｃａｌｄ．＝１．５８ｇ·ｃｍ－３，μ（ＭｏＫα）＝１３．２５ｃｍ－１。中心镧离子与冠醚配体中的４个氧原子和２个氮原子配位，３个硝酸根中的６个氧原子也与Ｌａ３＋配位，形成配位数为１２的配合物。     

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.     

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.