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1.
A new electroactive polynuclear inorganic compound of rare earth metal, gadolinium hexacyanoferrate (GdHCF), was prepared and characterized using the techniques of FTIR spectroscopy, thermogravimetric analysis (TG), UV-Vis spectrometry, X-ray photoelectron spectroscopy (XPS), ICP atomic emission spectroscopy, and EDX. The results of ICP atomic emission spectroscopy, EDX, and TGA indicated that the prepared GdHCF sample had a stoichiometry of NaGdFe(CN)6·12H2O (when GdHCF was prepared in NaCl solution). The FTIR spectrum of GdHCF showed that there were two types of water molecules in the structure of GdHCF: one was the interstitial water (5 H2O), which resulted from the association of water due to H-bonding, and the other was water coordinated with Gd (7 H2O). The results obtained using XPS showed that the oxidation state of Fe and Gd in the GdHCF sample was +2 and +3, respectively. GdHCF was immobilized on the surface of spectroscopically pure graphite (SG) electrode forming the GdHCF/SG electrode, and the solid-state electrochemistry of the resultant electrode was studied using cyclic voltammetry. The cyclic voltammetric results indicated that the GdHCF/SG electrode exhibited a pair of well-defined and stable redox peaks with the formal potential of E0′=(197±3) mV. The effects of the concentration of the supporting electrolyte on the electrochemical characteristics of GdHCF were studied, and the results showed that the value of E0′ increased linearly with the activity of the cationic ion of the supporting electrolyte (lgaNa+), with a slope of 54.1 mV, which may become a novel method for determining the activity of Na+ in solution. Further experimental results indicated that GdHCF had electrocatalytic activities toward the oxidation of dopamine (DA) and ascorbic acid (AA), and the electrocatalytic current increased linearly with the concentration of DA (or AA) in the range of 1.0–10.0 mmol·L?1 (for DA) or 0.5–20.0 mmol·L?1 (for AA). 相似文献
2.
迄今未见任何稀土氨基酸络合物的ESR波谱报道,本文在合成Gd3+分别与甘氨酸、β-丙氨酸、谷氨酸、天冬氨酸和天冬酰胺五种氨基酸络合物的基础上,测定了不同温度下,水溶液、粉末及分子筛吸附样品的ESR谱,讨论了络合物中晶体场强,对称性及成键特性。 相似文献
3.
Gunter Zwilling 《Monatshefte für Chemie / Chemical Monthly》1981,112(2):157-165
The anodic overvoltage on carbon and platinum electrodes in the electrochemical production of high purity gadolinium from molten 75 LiF-25 mol% GdF3 solutions is discussed. At the cell temperature of 840°C calciumimpregnated anodes led to the reduction of inert electrode films and to a current yield of nearly 100%.The deposited gadolinium contained 75, 22, 54 and less than 100 ppm of the interstitial elements H, N, O and C respectively; the concentrations of the highest other analysed impurities were: Si (89), Fe (15), Y (5), Zr (3), Nd (3), Tb (71), Ta (49), W (23) and Re (<3 ppm).Partly performed at the Ames Laboratory—U.S. Department of Energy. 相似文献
4.
一缩二甘醇酸体系荧光分析法同时测定钆和铽 总被引:3,自引:0,他引:3
本文研究了Gd^3^+,Tb^3^+与一缩二甘醇酸形成络合物的荧光性能及发光机理,探讨了Gd^3^+,Tb^3^+同时测定的最佳条件和共存离子的影响。Gd^3^+,Tb^3^+的检测限分别为160和3ng/ml。并将该法成功地应用于稀土氧化物中Gd^3^+,Tb^3^+的测定。 相似文献
5.
Gadolinium dicyanamide dihydrate Gd[N(CN)2]3 · 2 H2O was prepared by ion exchange in aqueous solution followed by evaporation of the solvent at room temperature. Gd[N(CN)2]3 · 2 H2O was characterized by single‐crystal structure analysis, FTIR spectroscopy and DSC analysis. In the crystal there are three crystallographically independent [N(CN)2]? ions and Gd3+ which are coordinated by six N atoms from six different [N(CN)2]? ions and two O atoms from two water molecules forming an irregular quadratic antiprism. Four H bonds have been identified in the structure of Gd[N(CN)2]3 · 2 H2O, two of them running to terminal N atoms and two to the bridging N atoms of dicyanamide ions (Gd[N(CN)2]3 · 2 H2O: P21/n (no. 14), a = 7.4845(15) Å, b = 11.529(2) Å, c = 13.941(3) Å, β = 93.98(3)°, Z = 4, 1948 reflections, 175 parameters, R1 = 0.0493). The DSC analysis indicates that Gd[N(CN)2]3 · 2 H2O looses the crystal water at temperatures around 130 – 140 °C forming anhydrous Gd[N(CN)2]3, the structure of which has been refined by the Rietveld method based on X‐ray powder diffraction data. Gd[N(CN)2]3 was found to be isotypic with Ln[N(CN)2]3 (Ln = La, Ce, Pr, Nd, Sm and Eu) which previously have been described in the literature. 相似文献
6.
7.
Summary An isotope dilution method for the determination of rare earth impurities in uranium has been developed and Ce, Nd, Sm, Eu and Gd have been determined in uranium oxide samples. The method involves isotopic dilution with enriched isotopes of the rare earths being measured, followed by the separation of rare earths from uranium. A mass spectrometer with thermionic source was used to determine the relative isotopic abundances in each of these rare earths. All these five elements were analysed selectively by preferential evaporation technique. Trace concentrations down to parts per billion range can be measured with good sensitivity and accuracy.
Bestimmung von Verunreinigungen an Seltenen Erden in hochreinem Uran durch Isotopenverdünnungsanalyse
Zusammenfassung Eine Isotopenverdünnungsmethode wurde ausgearbeitet zur Bestimmung von Ce, Nd, Sm, Eu und Gd in Uranoxidproben. Das Verfahren umfaßt isotopische Verdünnung mit angereicherten Isotopen der zu bestimmenden Elemente und nachfolgende Abtrennung der Seltenen Erden von Uran. Die relativen Isotopenhäufigkeiten wurden mit Hilfe eines Massenspektrometers mit thermischer Ionenquelle bestimmt. Alle fünf Elemente wurden durch selektive Verdampfung analysiert. Spurenkonzentrationen bis herab zum ppb-Bereich konnten mit guter Empfindlichkeit und Genauigkeit erfaßt werden.相似文献
8.
Ute Ch.?Rodewald Mar’yana?Lukachuk Rolf-Dieter?Hoffmann Rainer?P?ttgenEmail author 《Monatshefte für Chemie / Chemical Monthly》2005,136(12):1985-1991
Summary. The gadolinium–rhodium–indide Gd3Rh1.940(7)In4 was prepared by arc-melting of the elements and subsequent annealing in a corundum crucible in a sealed silica tube. Gd3Rh1.940(7)In4 adopts the hexagonal Lu3Co1.87In4 type, space group
, a = 781.4(5), c = 383.8(3) pm, wR2 = 0.0285, BASF = 0.375(1) (merohedric twinning via a twofold axis (xx0)), 648 F2 values, 22 variables. The structure is derived from the well known ZrNiAl type through an ordering of rhodium and indium
atoms on the Ni2 sites. The Rh/In ordering forces a reduction of the space group symmetry from
to
, leading to merohedric twinning for the investigated crystal. The Rh1 site has an occupancy of only 94.0(7)%. The investigated
crystal had a composition Gd3Rh1.940(7)In4. The main geometrical motif are three types of centered, tricapped trigonal prisms, i.e., [Rh1In26Gd3], [Rh2Gd6In23], and [In1Gd6In23]. The shortest interatomic distances occur for Rh–In (276–296 pm) followed by In–In (297 pm). Together, the rhodium and indium
atoms build up a three-dimensional [Rh1.940(7)In4] network, in which the gadolinium atoms fill slightly distorted pentagonal channels. The crystal chemistry of Gd3Rh1.940(7)In4 is discussed on the basis of a group-subgroup scheme. 相似文献
9.
Isaac Zigelboim Daniel Offen Eldad Melamed Hana Panet Moshe Rehavi Yoram Cohen 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(3-4):323-329
Although magnetic resonance imaging (MRI) is one of the most important imaging modalities of the central nervous system (CNS),
one of the main drawbacks of MRI is its limited specificity. This can potentially be partially alleviated by target-specific
contrast agents. In the present paper we describe a simple high yield synthesis of two such gadolinium-based spiperone targeted
MRI contrast agents, 1a and 1b. The R1 relaxivities of 1a and 1b were evaluated and found to be 5.94 and 8.31 mM−1 s−1, respectively at 9.4T, while their R2 relaxivities at the same magnetic field were found to be 18.05 and 22.60 mM−1 s−1, respectively. In addition and very importantly compound 1a, which is a gadolinium-based, spiperone-targeted MRI contrast agent, was found to preserve some of the spiperone affinity
toward the dopamine D2 receptor. Compounds 1a and 1b thus represent potential agents for in vitro dopamine receptor imaging using MRI in experimental models.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
Christine Bauhofer Hansjürgen Mattausch Reinhard K. Kremer Arndt Simon 《无机化学与普通化学杂志》1995,621(9):1501-1507
The Gadolinium Carbide Halides, Gd4C2X3 (X = Cl, Br) The compounds Gd4C2X3 (X = Cl, Br) and Tb4C2Br3 have been prepared by reaction of the metals (RE), REX3, and C in sealed Ta capsules at 1 100° and 1 300°C, respectively. Monophasic samples of Gd4C2Br3 and Tb4C2Br3 were obtained by reacting stoichiometric mixtures of the starting materials for five days. The needle shaped crystals are bronze-coloured and sensitive to air and moisture. Gd4C2X3 crystallizes in the space group Pnma (No. 62) with lattice constants a = 1 059.6(4), b = 368.4(1), c = 1 962.7(8) pm (Gd4C2Cl3), a = 1 084.4(1), b = 373.0(1), c = 2 036.1(1) pm (Gd4C2Br3). According to Guinier photographs, Tb4C2Br3 is isotypic (a = 1 074.3(2), b = 370.6(1), c = 2 019.4(1) pm). In the crystal structure C is octahedrally coordinated by Gd. The Gd6 octahedra are linked via common edges to form corrugated layers. The X-anions coordinate all free edges and corners of these layers and connect them via Xi? Xi contacts parallel [001]. Gd4C2Br3 shows metallic conductivity. The magnetic susceptibility follows at high temperatures a Curie Weiss law with an effective moment of 7.95 μB. At temperatures below 50 K antiferromagnetic order is observed. 相似文献