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1.
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.  相似文献   

2.
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)  相似文献   

3.
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 La2+xGe2Mg1–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.  相似文献   

4.
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 SiF62– 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.  相似文献   

5.
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。  相似文献   

6.
Reaction of Co(OAc)2 · 4H2O with N-(2-hydroxybenzyl)salicylaldimine (H2La) in dimethylformamide (DMF)–H2O yields a linear trinuclear mixed valence complex [CoIII(μ-La)(μ-Lb)(μ-OAc)]2CoII · 2DMF (1). Here, HLb is salicylaldimine, which is afforded by an in situ transformation of H2La 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 (CoIII → CoII, quasi-irreversible) and +0.99 V (CoII → CoIII, irreversible) versus saturated calomel electrode, respectively. The magnetic behavior of 1 has been analyzed by the one-ion approximation with spin–orbit coupling in Oh symmetry giving λ = ?121 cm?1.  相似文献   

7.
8.
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.  相似文献   

9.
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.  相似文献   

10.
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].  相似文献   

11.
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: (Mn0.72,Fe0.13,Ca0.01)(Al)1.04(PO4, OHPO3)1.07(OH1.89,F0.02)·0.94(H2O) for SAA-090 and (Fe0.49,Mn0.35,Mg0.06,Ca0.04)(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.  相似文献   

12.
 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  相似文献   

13.
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.  相似文献   

14.
陈三平  范广  高胜利 《中国化学》2008,26(2):286-289
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)Å3, 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。  相似文献   

15.

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 (LHH2) was prepared by the reduction of LH2 with NaBH4 in MeOH medium. The treatment of this reduced complex with Cu2+ ion resulted a complex [(CuLH)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 [(CuLH)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.

  相似文献   

16.
《Chemical physics letters》2002,350(5-6):623-627
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.  相似文献   

17.
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...  相似文献   

18.
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.  相似文献   

19.
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 Niso atoms (isoindole N atoms) and one I atom in a tetragonal pyramidal arrangement. The Tl atom is located out of the centre of the (Niso)4 plane towards the iodine atom by 0.959(3) Å. The Tl–I distance is 2.674(1) Å, the Tl–Niso 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).  相似文献   

20.
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.  相似文献   

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