Synthesis,Interatomic Interactions,Structure, and Conductivity of Lanthanum Gallate Doped with Nickel and Magnesium

Russian Journal of General Chemistry - The coexistence of two crystal modifications of lanthanum gallate, orthorhombic and rhombohedral, was revealed for the first time in two series of solutions:...     

Investigation of New Ion-Conducting ORMOLYTES: Structure and Properties

Two families of hybrid organic-inorganic composites exhibiting Li⁺ ionic conduction (ORMOLYTES) have been prepared by the sol-gel process. The first family, prepared from a mixture of 3-isocyanatopropyltriethoxysilane, O,O Bis (2-aminopropyl)-polyethyleneglycol (or O,O Bis (2-aminopropyl)-polypropyleneglycol) and lithium salt, presents chemical bonds between the organic and the inorganic phase and an ionic conductivity higher than 10^-4 S m^-1 at room temperature. Their properties have been related to their structure using liquid state NMR measurements of ⁷Li between -100°C and +100°C and the DMTA technique. In the second family, prepared by ultrasonic method from a mixture of tetraethoxysilane (TEOS), polyethyleneglycol (PEG) and lithium salt, the organic and inorganic phases are not chemically bonded. Ionic conductivity has been studied as a function of the polymer chain length and concentration. Values of up to 10^-2 S m^-1 at room temperature have been obtained (with a silica-PEG₃₀₀ system, PEG/TEOS = 40% in weight). Again, structure was investigated by liquid state ⁷Li NMR measurements.     

Synthesis,Crystal Structure and Fluorescence Properties of a 3D Framework Based on Hexanuclear Lanthanum 5-Nitroisophthalate Entities

The reaction of lanthanum(Ⅲ) nitrate and 5-nitroisophthalic acid in isopropanol/H2O under hydrothermal conditions leads to a 3D lanthanum-containing coordination polymer with the general chemical formula {[La6(Nip)9(H2O)4 ]·(H2O)4 }∞(1,Nip=5-nitroisophthalate).The single-crystal X-ray analyses show that this compound crystallizes in the orthorhombic system,space group Ima2 with a=9.7769(12),b=28.239(3),c=21.149(2),V=5839.1(11)3,Z=2,Mr=2859.61,Dc =1.626 g/cm 3,F(000)=2752.14040 reflections are collected,of which 5275 are unique (R int=0.0241).Final GOOF=1.083,R=0.0406 and wR=0.1182,R indices based on 5183 reflections with I>2σ(I)(refinement on F2),443 parameters,1 restraint.Lp and absorption corrections were applied,=2.242mm-1.Absolute structure parameter x=0.08(3).The crystal structure can be described as the butterfly-liked hexanuclear lanthanum entities {La6O6(CO2)8 } covalently linked to each other by nitroisophthalate ligands into an intricate three-dimensional structure.The fluorescence spectroscopy of compound 1 has been investigated.     

Synthesis, Structure, and Bonding of Two Lanthanum Indium Germanides with Novel Structures and Properties

The new tetragonal phases La(3)In(4)Ge and La(3)InGe are obtained from high-temperature reactions of the elements in welded Ta followed by annealing. The structures of both were established by single-crystal X-ray diffraction in tetragonal space group I4/mcm (Z = 4 and 16, a = 8.5165(3) and 12.3083(2) ?, c = 11.9024(4) and 16.0776(4) ?, respectively). La(3)In(4)Ge contains layers or slabs of three-connected indium built of puckered 8-rings and 4-rings, or of squashed tetrahedra ("butterflies") interlinked at all vertices, and these are separated by layers of La and isolated Ge. The phase is deficient of being a Zintl phase by three electrons per formula unit and is better described in terms of an alternate optimized and delocalized bonding picture and an open-shell metallic behavior for the In slabs. The more complex La(3)InGe, isostructural with Gd(3)Ga(2), is also layered. This phase contains pairs of mixed-occupancy (0.75 In, 0.25 Ge) sites separated by 3.020 ?, as well as isolated In and Ge atoms. The former appear to be fully reduced closed-shell atoms (relative to the bonded Ga dimers in Gd(3)Ga(2)) that are held in somewhat close proximity by cation matrix effects. The compound appears to be semiconducting and thus is a classical Zintl phase, (La(+3))(3)In(-5)Ge(-4) in the simplest oxidation state notation. High Coulomb energies are presumably important for the nature of the bonding and the stabilities of both compounds.     

CaTiO3:Zn溶胶-凝胶法制备、结构及介电性能

采用溶胶-凝胶法制备了CaTiO3:Zn纳米粒子,透射电镜图显示平均粒径为25 nm.Zn的掺杂位置对于陶瓷相组成和烧结特性有很大影响.Ca1-xZnxTiO3和CaTiO3+zZnO样品的Zn以Zn2TiO4相形式存在;而CaZnyTi1-yO3-δy=0.01)样品中的Zn进入Ti位形成固溶体,无明显的降温效果,当Zn量增至0.05和0.1时,出现ZnO相.ZnO和Zn2TiO4第二相的存在均能明显促进陶瓷烧结.CaTiO3:Zn超细粉体可在较低温度下致密烧结(≤1 250 ℃).1 250℃烧结的CaZnyTi1-yO3-δ(y=0.01)陶瓷具有较好的介电性能:介电常数ε=157,品质因数Q×f=6 819 GHz,谐振频率温度系数(τ)f=7.51×10-4℃-1.     

Preparation and Properties of Doped Lanthanum Gallate Film on a Ni/SDC Porous Anode Support

IntroductionIn intermediate-temperature solid oxide fuel cells(SOFCs),doped ceria with a fluorite structure anddoped lanthanum gallate(LSGM)with a perovskitestructure are commonly used as electrolyte materials.However,the former easily exhibits an electro…     

新颖的镧-2-氟苯甲酸及2，2′-联吡啶配合物的合成与晶体结构

2-fluorobenzoic acid (2-HFBA) and 2,2′-bipyridine (2,2′-bpy) was used as ligands to react with lanthanum to obtain a complex, [La(2-FBA)₃·(2,2′-bpy)]₂. The structure of the complex contains three independent molecules. In two of them, the two central metal ions are connected together through four 2-FBA groups by bidentate bridging and chelating-bridging two modes. In another, the two central metal ions are connected together through four bidentate bridging 2-FBA groups. CCDC: 237658.     

Synthesis and Properties of Modified Fillers Based on Calcium and Magnesium Carbonates

A possibility of modifying natural carbonate fillers for paint and varnish industry by solutions of salts of some nonferrous metals was studied. Reactions of carbonates with metal ions and physicotechnical properties of the resulting materials were considered.     

Nanosized Vanadium Diboride: Synthesis,Structure, and Properties

Russian Journal of General Chemistry - X-ray diffraction, scanning electron microscopic, and X-ray photoelectron spectroscopic examinations, as well as energy dispersive X-ray and elemental...     

Synthesis and Magnetic Properties of Barium-Doped Nanocrystal Lanthanum Orthoferrite

Russian Journal of General Chemistry - Barium-doped nanocrystalline lanthanum ferrite was synthesized by the method of co-precipitation and subsequent annealing at 1000°C. The maximum degree...     

磷烯的制备、结构、性质及器件应用

磷烯是继石墨烯之后一种新型的二维材料,具有优异的物理、化学和机械性能,在各类器件中具有大的应用潜力。目前对磷烯的最新制备方法、特性调控和应用的系统总结较少。本文对磷烯的制备、结构、性质、改性方法及其器件应用进行了系统的综述。首先概括了磷烯"自上而下"和"自下而上"的制备方法,对其结构和性质进行了总结,同时讨论了磷烯的修饰改性方法,最后对磷烯的器件应用进行了较详细的介绍,并在此基础上对磷烯的研究方向和前景进行了展望。     

BN Fused Diazulenyl-Carbazole:Synthesis,Structure,and Properties

By combination of two special structural units,a boron-nitrogen-fused polycyclic aromatic hydrocarbon and azulene with strong in-tramolecular dipoles,a novel BN...     

Ruthenium-Based Perovskitelike Phases: Synthesis, Structure, and Properties

This paper reports on synthesis and X-ray diffraction study of two groups of phases obtained from batch mixtures: (La,Sr _k+1(Ru,Cu) _k O_3k+1 and (La,Sr)₃(Ru,Cu)₃O₆₊ (group I); RuSr₂LnCu₂O_8– (Ln = Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), RuSr₂(Ln,Ce⁴⁺)₂Cu₂O_10– (Ln = Pr and Nd for the first time, Sm, Eu, Gd, (Gd,Y) for the first time), and (Ru,Cu)Sr₂(Ln,Ce⁴⁺)₂Cu₂O_10– (Ln = Tb and Y for the first time) (group II). In group I, phases with K₂NiF₄, Sr₃Ti₂O₇, and cubic perovskite type structures are typically formed; in group II, these are respectively (Ru,Cu)(Sr,Ln)₂(Ln,Sr)Cu₂O_8– (1212 type), (Ru,Cu)(Sr,Ln)₂(Ln,Ce⁴⁺)₂Cu₂O_10– (1222 type), and cubic perovskite type structures (the content of the latter depends on the type of Ln). Variation of the formal charge (f.c.) of Ru (group I) and Cu (group II) was evaluated in relation to the cation composition of the phases (groups I and II) and the content of superstoichiometric oxygen (group II). Phases of 1222 type with Ln = Nd, Sm, Eu, Gd, and (Gd,Y) and phases of 1212 type with Ln = Gd exhibited superconducting properties with T _{c max} 40 K.     

Functionalized Hydrocarbon Belts: Synthesis,Structure and Properties

Hydrocarbon belts have drawn great attention because of their unique structures and tantalizing properties. Although a few belts and heteroatom-doped analogs have been synthesized, belt molecules containing non-hexagonal rings remain rare. Herein we report the construction and application of unprecedented zigzag-type hydrocarbon belts which contain functionalized eight-membered rings. The synthesis features fourfold intramolecular acylation reactions of resorcin[4]arene-derived intermediates, which affords C₄-symmetric tetrabenzobelt[4]arene[4]cyclooctatrienones. Stereoselective ketone reduction with LiAlH₄ and nucleophilic addition with alkynyllithiums provide the corresponding tetrahydroxylated belts. The tetraol and its methyl ether are powerful and selective hosts to form 2 : 1 and 1 : 1 complexes with cesium ion, respectively, with binding constants up to (1.71±0.33)×10¹¹ M⁻² and (1.50±0.16)×10⁶ M⁻¹. In addition, enantiopure C₄-symmetric belts can emit CPL with |g_lum| being around 0.01.     

Synthesis,Crystal Structure,and Magnetic Properties of a Quasi-one-dimensional Compound Based on TCNQ

A novel compound, （IBzQI）（TCNQ）2 2 （IBzQ1=1-（4-iodobenzyl）quinolinium and TCNQ = 7,7,8,8-tetracyanoquinodimethane） has been fabricated and X-ray single-crystal structurally analyzed. This compound crystallizes in the triclinic system, space group P1 with a = 8.3540（17）, b = 13.284（3）, c = 16.185（3） А, α= 82.12（3）, β= 75.19（3）, γ= 72.34°, V = 1651.2（6） А^3, Z= 2, C_40H_21IN_9, Mr = 754.56, Dc = 1.518 g/cm^3,μ= 1.015 mm^-1, S = 1.010, F（000） = 754, R = 0.0387 and wR = 0.0948. The structure analysis shows that the anions are stacked into column with tetrads, and there are two types of TCNQ entries （TCNQ-1 and TCNQ^0） in agreement with the IR spectra analysis of the compound. The temperature dependence of the magnetic susceptibility （2-300 K） for 2 exhibits spin gap of singlet-triplet feature, and the best fit gave △/kB = 1523.4 K. In order to understand both magnetic behavior and local charge distribution of [（TCNQ）2]-unit, the molecular orbital calculations and analysis based on extended Hückel method were performed, and the results support the analyses of both crystal structure and IR spectra.     

Synthesis,Structure, and Luminescent Properties of Two Complexes Based on Flexible Phenylenediacetate Ligand

Two new Zn(Ⅱ) and Cd(Ⅱ) coordination complexes, [Zn(ppda)(idz)]_n(1) and [Cd(mpda)(mbib)]_n(2)(H2 ppda = 1,4-phenylenediacetic acid, H_2 mpda = 1,3-phenylenediacetic acid, idz = imidazole, mbib = 1,3-bis(imidazol-1-ylmethyl)benzene), have been synthesized by using Zn(Ⅱ)/Cd(Ⅱ) salt and phenylenediacetic acid in the presence of different imidazole ligands under hydrothermal conditions, and characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and thermogravimetric analysis. Complex 1 crystallizes in orthorhombic system, Iba2 space group. The carboxylic acid ligands form a 2 D helical layer with Zn(Ⅱ) ions, and such layers are expanded into a 3 D network structure by the force of C–H×××π. Complex 2 crystallizes in monoclinic system, P2_1/n space group. Complex 2 shows a 3 D framework with two Cd(Ⅱ) ions as nodes of a dual-core unit, which can be considered to be 6-connected net and regarded as a rare(4~4,5~(10),7) topology network with self-interlacing. The structural diversities indicate that rigid and flexible imidazole ligands play dominating roles in modulating the formation of structures of these crystalline materials. Moreover, the luminescent properties of two complexes are investigated in solid state.     

基于吡啶二羧酸配体的稀土配合物的合成、结构及性质

以2,6-二甲基吡啶-3,5-二羧酸（H₂L₁）为主配体,1,10-菲咯啉（L₂）为辅配体,分别与五水合硝酸镝、六水合硝酸铽及六水合硝酸铕通过水热法合成[Dy₂（L₁）₃（L₂）₂]_n（1）、{[Tb₂（L₁）₃（L₂）₂]·5H₂O}_n（2）和{[Eu₂（L₁）₃（L₂）₂]·5H₂O}_n（3）三种配合物。通过单晶X射线衍射、红外光谱、荧光光谱和热重分析对其结构进行了表征与性质研究。结果表明,配合物1~3均以稀土离子为金属节点连接配体L₁^2-和L₂,形成无限延伸的一维链状结构。     

Structure,Microstructure, Composition and Properties of Lanthanum Lithium Titanates and some Substituted Analogues

The very high value of ionic conductivity at room temperature reported for La_0.51Li_0.34TiO_2.94 some years ago did originate a great deal of interest in the study of materials of general formula La_2/3–xLi_3xTiO₃ (LaLiTiO) and related systems. These oxides have shown to be potential solid electrolytes for lithium secondary batteries, but other aspects, apart from the conducting properties, such as their dielectric behaviour and crystal structure, have been the main focus of important studies in the area of inorganic solid‐state chemistry. LaLiTiO‐related compounds have the perovskite‐type structure (ABO₃) with A‐cation ordering. However, essential details of their crystal structure, as for instance the location of the lithium atoms, are still under discussion and are the subject of current work. We show in this short review of mainly our own work that the complex microstructure of these materials, which has been studied in detail by transmission electron microscopy, is the cause of the difficulties on the precise determination of their crystal structure. We have developed a new approach for crystal structure refinement, which takes into account the microstructural effects, obtaining significantly better results than conventional methods of refinement. The microstructure of these oxides also affects their conducting and dielectric properties. Therefore, different parameters such as composition and microstructure must be considered to understand and, eventually, optimise, as we have done, the conducting properties of LaLiTiO‐related systems.