LaNi4M(Ni,Cu,Fe)-H2体系的量热研究

本文用量热法测定了氢在LaNi₅,LaNi₄Cu,LaNi₄Fe中溶解的相对偏摩尔焓△H_Hα→β和偏摩尔自由能△G_Hα→β,并计算了偏摩尔熵△S_Hα→β。用X光衍射分析计算了LaNi₅,LaNi₄Cu,LaNi₄Fe的晶胞体积V,发现了△H_Hα→β和△G_Hα→β)与V存在线性关系。     

Die Kristallstrukturen von β-TaNi3, Ta(Cu,Al)2, Nb(Cu,Al)2 und Ta6(Cu,Al)7

Zusammenfassung Neben der bekannten Phase TaNi₃ mit TiCu₃-Typ wird eine Kristallart gleicher Zusammensetzung gefunden, die mit TiAl₃ isotyp ist. Ta(Cu, Al)₂ und Nb(Cu, Al)₂ kristallisieren im MgZn₂-Typ (Laves-Phase). Ta₆(Cu, Al)₇ ist eine -Phase.     

SnO2—SiO2负载Cu,Ni催化剂的CO2加氢反应性能

采用表面反应改性法制备了SnO2-SiO2(SnSIO)表面复合物载体,用等体积浸渍法制备了SnSiO担载的Cu-Ni双金属催化剂,借助BFT,XRD,TPR,IR和微反等技术研究了SnSiO及其负载的Ni,Cu双金属催化剂的表面构造,化学吸附及CO2加氢反应性能,结果表明：SnSiO是SnO2单分子层价联于SiO2表面的复合氧化物,仍保持类似SiO2载体的孔结构和比表面;SnO2引入SiO2表面后可以有效地促进CuO,NiO的还原,还原后成为负载在SnSiO载体表面的Cu-Ni合金,CO2在负载型Cu-Ni合金表面Cu或表面Ni位 发生化学吸附,形成线式和剪式吸附;CO2在催化剂上的加氢反应产物主要是CH3OH,CH4,CO和H2O,生成CH3OH的选择性与催化剂组成及反应条件密切相关,Cu-Ni催化剂,在0．5MPa,170度,H2。CO2（mol/mol)为3 的条件下,CH3OH的选择性达到84．6％。     

State of uranyl silicates MII(HSiUO6)2 ·6H2O (MII=Mn, Co, Ni, Cu, Zn) in aqueous solutions

Uranyl silicates with formula M^II(HSiUO₆)₂·6H₂O (M^II=Mn, Co, Ni, Cu, Zn) were investigated in aqueous solutions in the pH range of 0÷14. The pH interval was established where compounds preserve their composition and structure. It varies in the pH range of (3.5–4.0)÷(10.8–11.4) and depends on M^II type. Out of this pH interval investigated uranyl silicates convert to the compounds of other composition and structure, such as amorphous silica, polyuranates and hydroxides of 3d-transition elements. The solubility of M^II(HSiUO₆)₂·6H₂O was determined, it’s value changes on the several orders of magnitude from 10^?6 M in subalkali solutions to 10^?3 M in acid and strongly alkaline media. Using obtained experimental data the solubility products and solubility curves of uranyl silicates were calculated by mathematical modeling. Also the speciation diagrams of uranium (VI), silicon (IV) and M (II) in solutions and solids were plotted.     

Dependence of the Structure and Properties of (M,Cu)Sr2(Ln,Ca)Cu2O8−δ (1212) and (M,Cu)Sr2(Ln,Ce4+)2Cu2O10−δ (1222) Phases on the Cation M

The composition and structure of (M,Cu)(Sr,Ln)₂(Ln,Ca,Sr)Cu₂O_8– phases, where M = B, Al, Cr, Pb, Bi, Ru, or Mo (1212 type), and (M,Cu)(Sr,Ln(₂(Ln,Ce⁴⁺)₂Cu₂O_10– phases, where M = V, Cr, Mn, Ru, or Mo (1222 type), have been determined. The role of the M cation in the formation of the crystal structures and the superconductivity phenomenon was analyzed. The relationship between the type of M cation and structural parameters was discovered.     

Crystal Structure of (Hg, Ce, Cu)(Sr, Pr)2(Pr, Sr)Cu2O6+δ and (Hg, \square )(Sr, Pr)2(Pr, Sr)2Cu3O8+δ Phases

This paper reports on the refined compositions and crystal structures of two phases from the homologous series (Hg, M)(Sr, Pr)₂(Pr, Sr)_k-1Cu_kO_2k+2+ with k = 2 (Hg-1212) — (Hg_0.44(2)Ce _0.31 ⁴⁺ Cu_0.25)(Sr_0.90(3)Pr_0.10)₂(Pr_0.52(3)Sr_0.48)Cu_2.00O_7.00 (a = 3.8634(1), c = 12.2030(8) , space group P4/mmm) with k = 3 (Hg-1223) — (Hg_0.29(1) )(Sr_0.67(2)Pr_0.33)₂(Pr_0.61(2)Sr_0.39)₂Cu_3.00O_9.32(8) or (Hg_0.29(1) )(Sr_0.61(4)Pr_0.39)₂(Pr_0.51(4)Sr_0.49)₂Cu_3.00O_9.00 (with a fixed content of superstoichiometric oxygen O(4) in the phase) ( is a vacancy; a = 3.8294(9), b = 3.8567(6), c = 15.2763(44) , space group Pmmm). The implausibly high content of oxygen in the Hg-1223 phase (refinement I) is attributed either to O–O bond formation or to the possible presence of a minor amount of copper in a defect position of Hg; the inclusion of the latter in structure refinement leads to a better reproduction of the real structure but increases the R indices. The crystal-chemical analysis of the title phases and a comparison with the available data for analogous phases indicates that the composition of the crystallographic positions is related to structural features, in particular, to the coordinates of (Hg, M) and superstoichiometric oxygen, whose content depends on the degree of substitution of strontium ions by praseodymium ions. Reasons for the orthorhombic distortion of the Hg-1223 phase are discussed. The absence of superconductivity is explained by the nonoptimal formal charge (FC) of copper, which depends on the oxygen content in the phase.     

金属(Fe,Co,Ni,Cu)掺杂的Mo2C催化剂在TiO2表面用于中性条件光催化分解水产氢

中性条件下的分解水产氢(HER)是化工领域的重要反应之一,其效率取决于催化剂的内在特性.在本工作中,我们利用3d金属(Fe,Co,Ni,Cu)对Mo2C进行掺杂来调节其费米能级,从而达到催化剂可在中性条件下吸附水并提高最终活性的目的.首先,利用简单浸渍法将四种金属的前驱体吸附到MoO3表面,然后通过煅烧一步合成金属掺杂的Mo2C.产物Mo2C的XRD峰位移以及XPS表征结果表明,四种金属通过掺杂进入到了Mo2C晶格.利用HRTEM以及相应的元素面扫分析,也证明金属确实掺杂进入了Mo2C体相.考察了Mo2C基催化剂在中性条件下电解水产氢的性能,结果表明,在10 mA/cm2条件下,Cu-Mo2C催化剂表现出最优的HER性能,其次,是Ni-Mo2C,Co-Mo2C,Fe-Mo2C和纯Mo2C,它们的过电位分别为78,90,95,100和173 mV,Tafel斜率分别是40,43,42,56和102 mV/dec.利用阻抗测试详细分析了催化剂-反应液界面电阻Rct的变化情况,样品Mo2C,Fe-Mo2C,Co-Mo2C,Ni-Mo2C和Cu-Mo2C拟合后的Rct值分别为119,89.6,46.5,33.8和23.2 ohm/cm^2,表明金属掺杂能明显降低催化剂的反应界面电阻.由于电催化过程的主要研究对象是表面双电层,所以我们利用循环伏安法计算了催化剂表面双电层的数值,得到上述五个样品的Cdl数值分别为0.047,0.06,0.1,0.16和0.24 F/cm^2,双电层的提高为催化剂表面提供了更多的反应位点.考虑了到光解水的界面反应实质也是电催化过程,我们通过浸渍方法将催化剂负载到锐钛矿TiO2表面,考察调控的功函数对光催化效率的影响.XPS表征验证了M-Mo2C负载于TiO2表面.负载助催化剂的TiO2-M-Mo2C样品均表现出了优于纯TiO2的光解水产氢性能.样品TiO2-Cu-Mo2C,TiO2-Ni-Mo2C,TiO2-Co-Mo2C,TiO2-Fe-Mo2C,TiO2-Mo2C和纯TiO2的产氢速率分别为21,404,275,224,147和112μmol/h.利用瞬态荧光研究了载流子在助催化剂和TiO2两相的界面迁移,通过单指数拟合得到样品TiO2,TiO2-Mo2C,TiO2-Fe-Mo2C,TiO2-Co-Mo2C,TiO2-Ni-Mo2C,TiO2-Cu-Mo2C和TiO2-Pt的荧光寿命分别是22.6,20.5,10.1,4.7,4.0,2.5和1.9 ns,说明不同金属掺杂的Mo2C对提取光生电子的效果不同,元素Cu最有效.进一步利用瞬态吸收光谱研究了TiO2-Mo2C,TiO2-Cu-Mo2C和TiO2-Pt三个样品的载流子迁移,同样采用单指数拟合得到的荧光寿命分别为105,73和31 ps,进一步说明掺杂Cu后助催化剂Mo2C对于提取TiO2的光生电子寿命具有很好的促进作用.利用UPS技术探究了金属掺杂后Mo2C的缺陷能级位置,从计算结果可以看出,元素Cu掺杂后Mo2C具有更深的缺陷能级,该能级对吸附水具有促进作用.利用原位红外光谱对样品进行了水蒸气吸附测试,结果表明,Mo2C,Fe-Mo2C,Co-Mo2C,Ni-Mo2C和Cu-Mo2C样品依次的吸附水性能提升.综上,我们利用3d金属对助催化剂进行了缺陷调控来调变其对水的起始吸附过电位,该工作对设计性能优异的光解水助催化剂具有一定的借鉴意义.     

Electrochemical synthesis of neutral transition metal(II) (Fe,Co, Ni,Cu, Zn) complexes of pyridine-2-carbaldehyde pyridin-2′-ylhydrazone and several analogues

Summary Neutral transition metal(II) complexes of pyridine-2-carbaldehyde pyridin-2-ylhydrazone (papyH) and several analogues have been prepared by electrochemical synthesis. The [M(papy)₂] compounds (M = Fe, Co, Ni, Cu or Zn) were obtained mostly as red-green dichroic substances as a result of the extended -conjugation system in the anionic hydrazone. Vibrational and electronic spectra confirm the presence of the anionic hydrazone and its tridentate coordination to the metal centre.     

同位素稀释质谱法测量贻贝中微量Ni,Cu,Pb

以天然丰度镍、铜、铅标液为稀释剂标定浓缩同位素￣（６２）Ｎ、￣（６５）Ｃｕ、￣（２０７）Ｐｂ溶液浓度，再以此浓缩同位素为稀释剂，用同位素稀释质谱法（ＩＤＭＳ）测量贻贝中Ｎｉ、Ｃｕ、Ｐｂ的含量。测量结果：贻贝中Ｎｉ，１．０１１±０．０１２×１０￣（－６）；Ｃｕ：７．６２±０．１４×１０￣（－６）；Ｐｂ：２．００８±０．０２４×１０￣（－６）。     

Synthesis,crystal structure,thermal decomposition,and XPS studies of homo and heterotrinuclear Cu(II)–Cu(II)–Cu(II) and Cu(II)–Ni(II)–Cu(II) complexes obtained from salpn type ligands

In this study, a mononuclear CuL complex was prepared by the use of bis-N,N′-(salicylidene)-1, 3-propanediamine (LH₂) and Cu²⁺ ion. NiCl₂ and NiBr₂ salt were treated with this complex in dioxanewater medium and two new complexes [(CuL)₂NiCl₂(H₂O)₂] and [(CuL)₂NiBr₂(H₂O)₂)] with Cu(II)–Ni(II)–Cu(II) nucleus structure were obtained. In addition to this bis-N,N′-(2-hydroxybenzyl)-1,3-diaminopropane (L^HH₂) was prepared by the reduction of LH₂ with NaBH₄ in MeOH medium. The treatment of this reduced complex with Cu²⁺ ion resulted a complex [(CuL^H)₂CuCl₂] with a structure of Cu(II)–Cu(II)–Cu(II). The complexes prepared were characterized by the use of elemental analysis, IR spectroscopy, thermogravimetric and X-ray diffraction methods. The crystal structures of [(CuL)₂NiBr₂(H₂O)₂] (СIF file CCDC 1448402) and [(CuL^H)₂CuCl₂] (СIF file CCDC 1448401) complexes were elucidated. It was found that halogen ions are coordinated to terminal Cu²⁺ ions which are in a distorted square pyramid coordination sphere. It was determined that the central Cu(II), which joins terminal square pyramidal Cu(II), was coordinated only by the phenolic oxygens of the ligand while the central Ni(II) was coordinated by two phenolic oxygens of the organic ligand and two water molecules. These complexes were investigated by XPS and it was found that the terminal and central Cu²⁺ ions were different in Cu(II)–Cu(II)–Cu(II) complex. Also, the thermal degradation of the CuLH complex unit was observed to exothermic in contrast to the expectations.

     

Synthesis,crystal structure,magnetic and spectroscopic properties of {[Cu(oxbe)(py)]2Ni(py)2}·2Dmf complex of dissymmetrical oxamidate

The trinuclear complex {[Cu(oxbe)(py)]₂Ni(py)₂}·2DMF has been prepared and characterized by elemental analysis, IR and electronic spectra and magnetic susceptibility, where H₃oxbe is the dissymmetrical ligand N-benzoato-N′-(2-aminoethyl) oxamido, py?=?pyridine, DMF?=?dimethylformamide. The molecular structure of this complex is centrosymmetrical and has an extended oxamido-bridged structure consisting of two pyramidal copper(II) and one octahedral nickel(II) ions. The central Ni(II) and two terminal Cu(II) ions are antiferromagnetically coupled, J?=???60.2?cm^?1.     

Study of the state of uranogermanates MII(HGeUO6)2·6H2O in Aqueous Solutions (MII = Mn, Co, Ni, Cu, Zn)

The state of d-elements uranogermanates M^II(HGeUO₆)₂·6H₂O in aqueous salt solutions in a wide range of ionic strength, ionic composition, and acidity has been investigated. The pH ranges of the uranogermanates stability have been determined, and products of their transformation have been identified. Solubility, solubility equilibrium constant, and Gibbs energy of formation have been determined for the studied uranogermanates. Diagrams of uranium(VI), germanium(IV), and M(II) state in aqueous solutions and in equilibrium solid phases have been plotted.     

STUDIES ON CRYSTAL AND MOLECULAR STRUCTURES OF DEMETHYLCANTHARATE-M (M=Zn, Cu, Ni, Co)

The complexes of demethylcantharic acid coordinating with Zn~(2+), Cu~(2+), Ni~(2+) and Co~(2+) wereprepared and the five crystal structures were all determined by X-ray diffraction. Metal ions in thefive structures are of six-membered coordination. The demethylcantharate ions can act as a tri-,tetra- or penta-dentate ligand toward metal ions to form ion-pair structure, chain structure or threedimensional polymer structure respectively. The bridge oxygen atom in ligand always participatesin coordination. In the structures of KM(C_8H_8O_5)_2·6H_2O, the formal valence of M (Ni, Co) is+3, but the data of crystal structures show that M are M~(2+) ions and Ni may form a Ni~(2+) -stabilizedligand radical. In addition, the metal ions are assumed to be probes and some possible Interactionsbetween the acceptor and the receptor are discussed.     

Al_2O_3负载Cu,Fe或Ni掺杂氧化钼催化乙苯氧化脱氢(英文)

Molybdenum-based catalysts supported on Al_2O_3 doped with Ni, Cu, or Fe oxide were synthesized and used in ethylbenzene dehydrogenation to produce styrene. The molybdenum oxide was supported using an unconventional route that combined the polymeric precursor method(Pechini) and wet impregnation on commercial alumina. The samples were characterized by X-ray diffraction(XRD), N_2 adsorption-desorption isotherms, temperature-programmed reduction of H_2(H_2-TPR),and thermogravimetric(TG) analysis. XRD results showed that the added metals were well dispersed on the alumina support. The addition of the metal oxide(Ni, Cu, or Fe) of 2 wt% by wet impregnation did not affect the texture of the support. TPR results indicated a synergistic effect between the dopant and molybdenum oxide. The catalytic tests showed ethylbenzene conversion of 28%–53% and styrene selectivity of 94%–97%, indicating that the addition of the dopant improved the catalytic performance, which was related to the redox mechanism. Molybdenum oxides play a fundamental role in the oxidative dehydrogenation of ethylbenzene to styrene by its redox and acid–base properties. The sample containing Cu showed an atypical result with increasing conversion during the reaction, which was due to metal reduction. The Ni-containing solid exhibited the highest amount of carbon deposited, shown by TG analysis after the catalytic test, which explained its lower catalytic stability and selectivity.     

New Ni(Ⅱ)Cu(Ⅱ)Ni(Ⅱ) trinuclear complexes with an S=3/2 high-spin ground state

Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)2]2[Cu(opba)]}(ClO4)2, where opba denotes o-phenylenebis(oxamato) and L stands for 1,10-phenanthroline(phen) (1), 5-nitro-1,10-phenanthroline(NO2-phen) (2), 2,2'-bipyridyl(bpy) (3) and 4,4'-dimethyl-2,2'-bipyridyl(Me2bpy) (4). The temperature dependence of the magnetic susceptibility of {[Ni(phen)2]2[Cu(opba)]}(ClO4)2.3H2O has been studied in the 4-300 K range, giving the exchange integral J=-109 cm-1. The MT vs. T plot exhibits a minimum at about 100 K, characteristic of this kind of coupled polymetallic complex with an irregular spin-state structure.     

Synthesis,structure, and electrochemical properties of [M(N-MeIm)6]2+ (M = Ni,Co, Cu) associated with [HgCl4]2−

Reaction of Hg(NO₃)₂ with 4 equivalent KI in water afford K₂[HgI₄]. By using K₂[HgI₄] as the precursor, three new heterobimetallic compounds [Ni(N-MeIm)₆][HgI₄] (I), [Co(N-MeIm)₆][HgI₄] (II), and [Cu(N-MeIm)₆][HgI₄] (III) have been characterized by elemental analysis, IR spectra, and the singlecrystal X-ray crystallorgraphy analysis. Three complexes are isomorphous and crystallized in monoclinic symmetry space group P2₁/c. The coordination around each center metal(II) atom is octahedral with six nitrogen atoms of N-MeIm ligand. Each structure contains one tetrahedral [HgI₄]^2? as an anion to balance the charge of the molecular. Thermogravimetry analysis indicates these complexes have the similar departure process and cyclic voltammogram exhibits a significant pair of redox peaks.     

Cyanido-bridged one-dimensional systems assembled from [ReIVCl4(CN)2]2? and [MII(cyclam)]2+ (M = Ni, Cu) precursors

Three new cyanido-bridged heterometallic Re^IVNi^II and Re^IVCu^II one-dimensional systems were synthesized and extensively characterized both structurally and magnetically. Single-crystal X-ray diffraction analysis revealed that these compounds display a common topology, with chains composed of alternating [Re^IVCl₄(CN)₂]^2? and [M^II(cyclam)]²⁺ (M = Ni in 1, Cu in 2) or [Cu^II(N,N??-dimethylcyclam)]²⁺ (in 3) building units. Two different chain orientations with a tilt angle of ca. 51° to 55° are present in the crystal packing of these compounds. The magnetic susceptibility measurements suggest the presence of intrachain ferromagnetic interactions between the S = 3/2 Re^IV centers and the 3d metal ions: S = 1 Ni^II or S = 1/2 Cu^II. At low temperature, a three-dimensional ordered magnetic phase induced by interchain antiferromagnetic interactions (antiferromagnetic for 1 and 2; canted antiferromagnetic for 3) is detected for the three compounds.     

Syntheses,Crystal Structures,Visible, and Near-Infrared Luminescence Properties of 3d–4f Coordination Polymers Cu2Er2 and Eu2Ni2

Russian Journal of Coordination Chemistry - Solvothermal condition reaction of Ln(NO3)3 ? 6H2O (Ln = Er, Eu) with 5-nitroisophthalate (Nipt2–) and mononuclear macrocyclic oxamide...     

Electrophilic Substitution Co(II)→M(II) (M = Mn,Ni, Cu,Zn, Cd) in Co2[Fe(CN)6] Gelatin-Immobilized Matrices

Electrophilic substitutions Co(II) M(II) (M = Mn, Ni, Cu, Zn, Cd) in cobalt(II) hexacyanoferrate(II) gelatin-immobilized matrices in contact with aqueous solutions of corresponding chlorides MCl₂ were studied. As a result of this contact, Co(II) was shown to be replaced to some extent by Ni(II), Cu(II), Zn(II), or Cd(II) and to give heteronuclear cobalt(II) hexacyanoferrates(II) and two-charge ions. A complete substitution of Co(II) or the formation the respective mononuclear hexacyanoferrate(II) M₂[Fe(CN)₂] was observed in neither of the studied systems Co(II) M(II). No Co(II) Mn(II) substitution was observed, even though the immobilized matrix was in contact with a solution for a long time.