Electrical conductivity of AgI–CdI2–KI and AgI–CuI–KI ionic conducting systems

Samples of general formulae (AgI)_4?2x(CdI₂)_xKI and (AgI)_4?x(CuI)_xKI, x = 0–0.4, have been prepared and studied by conductivity measurements, powder X-ray diffraction and DSC techniques. Room temperature XRD reveals the presence of the orthorhombic K₂AgI₃ as the major component in the system. DSC traces show endothermic peaks in the temperature range of 309–330 K, depending on the sample composition. These are attributed to the solid state reaction between AgI and K₂AgI₃ to form the cubic KAg₄I₅. Impedance spectra show the prominence of electrode – electrolyte interface effect which is explained in terms of the high rate of ion migration. Ionic conductivity enhances with the increase of Cd²⁺ content, while Cu⁺ contained samples show a decrease in conductivity with increasing Cu⁺ ratio though the ionic conductivity remains higher than that of the pure one.     

DBBD及其Cu(Ⅰ)配位聚合物[CuI(DBBD)2]n的合成

In this article we report the synthesis of (R,S)-4,4'-biquinoline-6,6'-dimethyl-3,3'-dicarboxylate (DBBD)(1) and the formation of copper(Ⅰ) coordination polymer [CuI(DBBD)2]n (2) by inducing a bidentate organic ligand (DBBD). The crystal 1 belongs to monoclinic system with space group P21, and a=0.881 30(19) nm, b=1.9660(6)system with space group Fmm2, and a=2.04441 (17) nm, b=1.543 06 (13) nm, c=1.65245 (13) nm, V=5.2129(7)     

Ternary Germanides RE 2Ge2Mg (REY, La–Nd, Sm, Gd, Tb)

Summary. The ternary rare earth metal-magnesium-germanides RE₂Ge₂Mg (RE=Y, La–Nd, Sm, Gd, Tb) were synthesized by reaction of the elements in sealed tantalum tubes in a water-cooled sample chamber of an induction furnace. The germanides were characterized through their X-ray powder patterns. The structures of Ce₂Ge₂Mg and Pr₂Ge₂Mg were refined from X-ray single crystal diffractometer data: Mo₂FeB₂ type, P4/mbm, a=750.6(1), c=442.4(1)pm, wR2=0.0378, 386 F² values, 12 variable parameters for Ce₂Ge₂Mg, and a=745.7(1), c=439.2(1)pm, wR2=0.0462, 448 F² values, 12 variable parameters for Pr₂Ge₂Mg. The lanthanum compound shows a homogeneity range La_2+xGe₂Mg_1–x. The structure of a single crystal with x=0.249(5) was refined from X-ray data: a=770.52(7), c=447.4(1)pm, wR2=0.0481, 322 F² values, 13 variable parameters. The RE₂Ge₂Mg structures can be considered as a 1:1 intergrowth of CsCl and AlB₂ related slabs of compositions REMg and REGe₂.     

Unexpected complexation of allylpseudothiohydantoin hydrochlorides towards CuX (X = Cl,NO3, ClO4, BF4, 1/2SiF6). The first known examples of joint CuI(Cl,ClO4) and CuI(Cl,BF4) π-complexes

By means of alternating current-electrochemical synthesis starting from a mixture of 2-imino-3-(prop-2-en-1-yl)-1,3-thiazolidin-4-one (3-allylpseudothiohydantoin, napt) and 2-allylamino-1,3-thiazol-4(5H)-one (allylaminopseudothiohydantoin, aapt) hydrochlorides and corresponding copper(II) salts five new π-complexes, [Cu(napt)Cl] (1), [Cu₂(aapt)₂Cl]NO₃ (2), [Cu₂(aapt)₂Cl]BF₄ (3), [Cu₂(aapt)₂Cl]ClO₄ (4) and [Cu₂(aapt)₂Cl]₂SiF₆·2H₂O (5), were obtained and studied by X-ray single crystal diffraction and IR-spectroscopy. Napt and aapt molecules are selectively coordinated to Cu⁺ depending on the anion type. In crystals of 1 and 5, the organic ligands are attached to the metal in a chelating N,(C=C)-bidentate mode. The aapt molecule in 2-4 acts as a tridentate chelating ligand, being coordinated to the copper(I) ion through the heterocyclic N atom, carbonyl O atom, and C=C bond of allyl group, forming an original cationic [Cu₂(aapt)₂Cl]⁺ fragment with both a bridging Cl^– ion and O atom of the C=O group. In the presence of the doubly charged SiF₆^2– anion, Cu(I) in 5 prefers to be bonded with two bridging Cl^– ions, rather than the C=O group, causing [Cu₂(aapt)₂Cl]⁺ units to associate into the infinite cationic chains. Crystals of 3 and 4 are the first known examples of the simultaneous BF₄^–/Cl^– or ClO₄^–/Cl^– participation in copper(I) π-complex formation.     

离子色谱法测定生活饮用水中的F~–,Cl~–,SO_4~(2–)和NO_3~–

建立了电导检测–离子色谱法同时测定生活饮用水中F–,Cl–,SO42–,NO3–的方法。选择30 mmol/L Na OH溶液为淋洗液,流量为1.40 m L/min,检测器电流为106 m A。F–的线性范围为0.15~2.0 mg/L,Cl–,SO42–,NO3–的线性范围为3.00~40.0 mg/L,4种离子的线性相关系数均大于0.999 5。F–,Cl–,SO42–,NO3–的方法检出限分别为0.02,0.13,0.14,0.02 mg/L,加标回收率在95.2%~103.0%之间。对环境标准204715进行了平行测试,各阴离子测定值均在标准值的不确定度范围内,测定结果的相对标准偏差小于2%(n=6)。该方法灵敏、准确、快速,可用于生活饮用水中F–,Cl–,SO42–,NO3–的同时测定。     

Synthesis,crystal structure,spectroscopy, and magnetism of a mixed valence Co(III)–Co(II)–Co(III) complex stabilized by N-(2-hydroxybenzyl)salicylaldimine

Reaction of Co(OAc)₂ · 4H₂O with N-(2-hydroxybenzyl)salicylaldimine (H₂L_a) in dimethylformamide (DMF)–H₂O yields a linear trinuclear mixed valence complex [Co^III(μ-L_a)(μ-L_b)(μ-OAc)]₂Co^II · 2DMF (1). Here, HL_b is salicylaldimine, which is afforded by an in situ transformation of H₂L_a via cleavage of the C–N bond. Complex 1 has been characterized by X-ray crystallography as well as elemental analysis, UV-Vis, and IR spectroscopy. The cathodic and anodic responses of 1 in DMF appeared at ?1.46 V (Co^III → Co^II, quasi-irreversible) and +0.99 V (Co^II → Co^III, irreversible) versus saturated calomel electrode, respectively. The magnetic behavior of 1 has been analyzed by the one-ion approximation with spin–orbit coupling in O_h symmetry giving λ = ?121 cm^?1.     

Influence of the Length of the Alanine Spacer on the Acidic–Basic Properties of the Ac–Lys–(Ala) n –Lys–NH2 Peptides (n?=?0, 1, 2, …, 5)

By using the potentiometric titration method, we have determined the pK _a values of the two terminal lysine groups in six alanine-based peptides differing in the length of the alanine chain: Ac?CLys?CLys?CNH₂ (KK), Ac?CLys?CAla?CLys?CNH₂ (KAK), Ac?CLys?CAla?CAla?CLys?CNH₂ (KAK2), Ac?CLys?CAla?CAla?CAla?CLys?CNH₂ (KAK3), Ac?CLys?CAla?CAla?CAla?CAla?CLys?CNH₂ (KAK4), and Ac?CLys?CAla?CAla?CAla?CAla?CAla?CLys?CNH₂ (KAK5) in aqueous solution. For each compound, the model of two stepwise acid?Cbase equilibria was fitted to the potentiometric-titration data. As expected, the pK _a values of the lysine groups increase with increasing length of the alanine spacer, which means that the influence of the electrostatic field between one charged group on the other decreases with increasing length of the alanine spacer. However, for KAK3, the pK _a1 value (8.20) is unusually small and pK _a2 (11.41) is remarkably greater than pK _a1, suggesting that the two groups are close to each other and, in turn, that a chain-reversal conformation is present for this peptide. Starting with KAK3, the differences between pK _a1 and pK _a2 decrease; however, for the longest peptide (KAK5), the values of pK _a1 and pK _a2 still differ by about 1 unit, i.e., by more than the value of log₁₀ (4)?=?0.60 that is a limiting value for the pK _a difference of dicarboxylic acids with increasing methylene-spacer length. Consequently, some interactions between the two charged groups are present and, in turn, a bent shape occurs even for the longest of the peptides studied.     

Thermodynamic Approach of Uranium(VI) Extraction by N,N-(2–ethylhexyl)Isobutyramide

The study of extraction of U(VI) from LiNO3 media by N,N-(2-ethylhexyl)isobutyramide (DEHiBA) in dodecane has been performed at 25.00 °C using isothermal titration microcalorimetry. The raw heat measured is a sum of contributions. To obtain the net extraction enthalpy variation, different heats have to be evaluated as the dilution of amide into dodecane phase which has been measured and subtracted. The microcalorimetric extraction results are then compared to data obtained by Van’t Hoff classical method. The extraction enthalpies obtained by both methods are similar. This first study allowed to define the experimental calorimetric conditions and will be followed by determination with other actinides and amides.     

具有内孔道的层状超分子化合物[(CuI)2(o-phen)2]的水热合成与晶体结构

固态金属配位超分子的晶体工程是化学和分子科学最活跃的研究领域之一, 它不仅因存在内孔和隧道等新颖网络特殊性而具有理论研究价值, 而且在催化、光学、主-客体化学以及分子电学等领域中具有巨大的潜在应用价值[1～8]. 用于构筑这类功能化合物的方法主要依赖于构筑网络的相互作用, 即利用分子间的氢键, π-π作用及其它的分子间弱的相互作用. 由于Cu-X体系超分子化合物优异的光学和催化性能, 它们的合成与表征近来已引起人们的极大兴趣[9,10].     

Vibrational spectroscopic characterization of the phosphate mineral series eosphorite–childrenite–(Mn,Fe)Al(PO4)(OH)2·(H2O)

The phosphate mineral series eosphorite–childrenite–(Mn,Fe)Al(PO₄)(OH)₂·(H₂O) has been studied using a combination of electron probe analysis and vibrational spectroscopy. Eosphorite is the manganese rich mineral with lower iron content in comparison with the childrenite which has higher iron and lower manganese content. The determined formulae of the two studied minerals are: (Mn_0.72,Fe_0.13,Ca_0.01)(Al)_1.04(PO₄, OHPO₃)_1.07(OH_1.89,F_0.02)·0.94(H₂O) for SAA-090 and (Fe_0.49,Mn_0.35,Mg_0.06,Ca_0.04)(Al)_1.03(PO₄, OHPO₃)_1.05(OH)_1.90·0.95(H₂O) for SAA-072. Raman spectroscopy enabled the observation of bands at 970 cm⁻¹ and 1011 cm⁻¹ assigned to monohydrogen phosphate, phosphate and dihydrogen phosphate units. Differences are observed in the area of the peaks between the two eosphorite minerals. Raman bands at 562 cm⁻¹, 595 cm⁻¹, and 608 cm⁻¹ are assigned to the ν₄ bending modes of the PO₄, HPO₄ and H₂PO₄ units; Raman bands at 405 cm⁻¹, 427 cm⁻¹ and 466 cm⁻¹ are attributed to the ν₂ modes of these units. Raman bands of the hydroxyl and water stretching modes are observed. Vibrational spectroscopy enabled details of the molecular structure of the eosphorite mineral series to be determined.     

Theoretical study of group 11 metal–silonyl complexes: M–SiO and M–(SiO)2 (M = Cu, Ag, or Au)

 The spectroscopic properties of M–SiO and M–(SiO)₂ (1–1 and 1–2 complexes with M = Cu, Ag, or Au) have been theoretically studied. It has been shown that both M–SiO and M–(SiO)₂ compounds in their ground state are bent with a metal–Si bonded structure. The calculated M(ns) spin density agrees well with the electron spin resonance experimental data. From a topological analysis, it has been shown that a rather large charge transfer occurs from the metal towards the SiO moiety, and that the M–Si bond energy correlates with the electron density located at the M–Si bond path (bond critical point). Received: 6 July 2000 / Accepted: 11 October 2000 / Published online: 19 January 2001     

Thermal and Microchemical Characterisation of Sol-Gel SiO2, TiO2 and xSiO2–(1–x)TiO2 Ceramic Materials

Amorphous SiO₂, TiO₂ and xSiO₂–(1–x)TiO₂ ceramic materials with selected values of x 0.5, 0.7 and 0.9, have been prepared via sol-gel process using silicon tetraethoxysilane (TEOS) and titanium tetraisopropoxide Ti(OPri)₄. By means of the combined use of differential thermal analysis (DTA),thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM),X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy(XAES), the surface microchemical structure and morphology of the sol-gel materials have been studied as a function of thermal treatments carried out in air up to 1200°C. In the range of temperature from 50 to 450°C, DTA-TG results evidence a remarkable mass loss due to the evaporation of organic solvents entrapped in the sol-gel materials and of the remnant organic components of the precursor metal alkoxides. In the range of temperature from 400 to about 1000°C, by means of the combined use of DTA, XRD, XPS and XAES techniques as a function of temperature and of chemical composition, it is possible to evidence the formation of crystalline phases such as quartz, anatase and rutile. Furthermore, line shape analysis of O1s XPS peak allows to distinguish between single O–Ti and O–Si bonds and also to disclose the presence of cross linking Si–O–Ti bonds, that act as bridges between SiO₂and TiO₂ moieties. As a function of temperature, Si–O–Ti bonds are broken and the formation of new Ti–O and Si–O bonds as in TiO₂ and SiO₂takes place as well as a silica segregation phenomenon. This revised version was published online in July 2006 with corrections to the Cover Date.     

配合物[Cu2(bpe)X2] n (bpe =1, 2–trans–(4–pyridyl)ethene, X=Cl, Br, I )的合成、晶体结构及热稳定性研究

以1,2-反式-二（4-吡啶基）乙烯桥连卤化铜分别得到配合物[Cu₂(bpe)Cl ₂] _n (1), [Cu₂(bpe)Br₂] _n (2) 和 [Cu₂(bpe)I₂] _n (3)。通过X-射线单晶衍射法对配合物1的结构进行了研究,晶体学数据：单斜晶系, P 2(1)/c空间群, a = 0.3788(8) nm, b = 1.5059(3) nm, c = 1.0875(2)nm, β = 96.262(4) °, V = 616.5(2)ų, Z = 2, S = 1.002,最终残差因子( I >2 σ ( I )) R ₁ = 0.0288, wR ₂ = 0.0579,对于全部数据 R ₁ = 0.0509, wR ₂ = 0.0615。元素分析及红外光谱分析表明,该类配合物为同晶化合物。另外,通过热重分析对配合物的热稳定性进行了研究。     

三维混合价态铜配位聚合物[Cu(Me_2dtc)_2(CuI)_3]_n的合成与晶体结构(英文)

A new three-dimensional copper dithiocarbamate-copper iodide coordination polymer [Cu(Me2dtc)2(CuI)3]n (Me2dtc=N,N-dimethyldithiocarbamate) was synthesized by reactions of Cu(OAc)2,NaI and Na(Me2dtc) in DMF solution,characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group C2/c with a=1.293 89(17) nm,b=1.077 61(11) nm,c=1.456 05(17) nm,β=115.585 (4)°,V=1.831 1 (4) nm3,Z=4,Dc=3.175 g·cm-3,Mr=875.28,λ (Mo Kα)=0.071 073 nm,μ=10.082 mm-1,F(000)=1 604,the final R=0.029 5 and wR=0.081 7. A total of 2 083 unique reflections were collected,of which 1 918 with I2σ(I) were observed. The Cu atoms are Cu(Ⅰ)/Cu(Ⅱ) mixed-valence and they have two different coordinate geometries,namely planar square and tetrahedron. This three-dimensional structure consists of individual Cu(Me2dtc)2 molecules linking together CuI polymeric chains which run parallel to the [001] direction vis Cu-S bonds.     

Ab initio study of Eu3+–L (L=H2O,H2S,NH2CH3, S(CH3)2, imidazole) complexes

The ground states and binding energies of Eu³⁺–L (L=H₂O,H₂S,NH₂CH₃,S(CH₃)₂, imidazole) complexes has been determined using ab initio techniques. The binding is mostly electrostatic as expected. The empty f orbital is different for the S compounds, being a π-like orbital, while for the O and N containing ligands it is a σ-like orbital. However, the range in the binding energies for the different f holes is small.     

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.

     

Complexes [Ni2(μ-OH2)(μ-O2CCH(CH3)2)2L2–4((CH3)2CHCO2)2]: Synthesis,Structure, and Mass Spectrometric Studies

Russian Journal of Coordination Chemistry - Three new binuclear aqua-bridged nickel(II) 2-methylpropionate complexes [Ni2(μ-OH2)(μ-O2CCH(CH3)2)2L2–4((CH3)2CHCO2)2] (L is...     

Iodophthalocyaninato(2–)thallium(III) – Synthese und Kristallstruktur

Iodophthalocyaninato(2–)thallium(III) – Synthesis and Crystal Structure Oxidation of dithalliumphthalocyaninate(2–) with excess iodine yields crystalline, blue-green iodophthalocyaninato(2–)thallium(III). It crystallizes in the orthorhombic space group Pnma (no. 62) with lattice parameters: a = 13.778(3) Å, b = 14.649(2) Å, c = 14.907(1) Å, Z = 4. The Tl atom coordinates four N_iso atoms (isoindole N atoms) and one I atom in a tetragonal pyramidal arrangement. The Tl atom is located out of the centre of the (N_iso)₄ plane towards the iodine atom by 0.959(3) Å. The Tl–I distance is 2.674(1) Å, the Tl–N_iso distances range from 2.20(1) to 2.23(1) Å (average 2.22(1) Å). The phthalocyaninate(2–) is severely distorted from planarity (concave distortion).     

Copper-sulfur interactions: synthesis and structure of a trigonal planar copper(I) complex with bis(diphenylthiophosphinyl)methane, [CuI(dppmS2)]·MeCN

Reaction of copper(I) iodide with 1,1-bis(diphenylthiophosphinyl)methane (dppmS₂) in a 1:1?mol ratio in acetonitrile yielded a complex of stoichiometry [CuI(dppmS₂)]·CH₃CN (1) whose X-ray structure determination has shown that the geometry around the copper center is nearly trigonal planar. Acetonitrile is nonbonded. Copper–sulfur bond distances are 2.2470(7) and 2.2591(7)?Å, while the copper–iodide bond distance is 2.4937(5)?Å. IR and NMR spectroscopic data also show the formation of copper–sulfur bonds. Lack of bridging by iodide led to the formation of a three-coordinate copper complex, as against the expected iodo-bridged dimeric complex with chelating dppmS₂.