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171.
Summary Selective and sensitive procedures are described for the direct differential pulse polarographic determination of antimony(III), indium(III) and cadmium(II) in propylene carbonate. This method was based on the salting-out extraction of their halide complexes into the solvent from acidic aqueous media. The extracted Sb(III), In(III) and Cd(II) complexes exhibit sharp differential pulse polarographic peaks at –0.21 V, –0.63 V and –0.72 V vs. SCE in salted-out propylene carbonate phases respectively. The lower limits of determination are 5.0g for Sb(III), 0.6g for In(III), and 0.2g for Cd(II) in 10 ml of the organic phase. A number of foreign ions are eliminated through both processes of solvent extraction and polarography using propylene carbonate.
Propylencarbonat als Lösungsmittel für die Fällungs-Extraktion und die nachfolgende Differential-Puls-Polarographie
Zusammenfassung Selektive und empfindliche Verfahren für die direkte Bestimmung von Sb(III), In(III) und Cd(II) in Propylencarbonat mit Hilfe der Differential-Puls-Polarographie wurden beschrieben. Die vorliegende Methode beruht auf der Fällungs-Extraktion der Halogenid-Komplexe aus wäßrig-saurem Medium in das Lösungsmittel. Die extrahierten Komplexe des Sb(III), In(III) und Cd(II) ergeben scharfe Peaks bei –0,21 V, –0,63 V und –0,72 V gegen die Kalomelelektrode in den betreffenden Propylencarbonat-Phasen. Die unteren Grenzen der Bestimmungen liegen bei 5,0g Sb, 0,6g In bzw. 0,2g Cd in 10 ml organischer Phase. Eine Anzahl Fremdionen wird durch die beiden Prozesse der Extraktion und der Polarographie in Propylencarbonat ausgeschaltet.相似文献
172.
R.V. Denys V.A. Yartys Masashi Sato R.G. Delaplane 《Journal of solid state chemistry》2007,180(9):2566-2576
A new intermetallic deuteride Ce2Ni7D4.7 with an anomalous volume expansion has been studied. Its structure was solved on the basis of in situ neutron diffraction data. Expansion proceeds along the c-axis and within the CeNi2 slabs only. All D atoms are located inside these slabs and on the border between CeNi2 and CeNi5. Ordering of D atoms in the bulk of CeNi2 is accompanied by substantial deformation of these slabs thus lowering the hexagonal symmetry to orthorhombic [space group Pmcn (No. 62); a=4.9251(3) Å, b=8.4933(4) Å, c=29.773(1) Å]. Inside the CeNi2 layer the hydrogen sublattice is completely ordered; all D-D distances exceed 2.0 Å. Local coordination of Ni by D inside the CeNi2 blocks is of “open”, saddle-like type. Hydrogen ordering is mainly determined by Ce-H and H-H interactions. The pressure-composition-temperature measurements yielded the following thermodynamic parameters of the formation of the hydride: ΔH=−22.4 kJ/molH, ΔS=−59.9 J/(K molH). 相似文献
173.
Generation of alkoxycarbenium ion pools from thioacetals and applications to glycosylation chemistry
[reaction: see text] Alkoxycarbenium ions have been generated and accumulated as "cation pools" by the low-temperature electrochemical oxidation of alpha-phenylthioethers. Although an unsuccessful attempt to accumulate glycosyl cations was made, a one-pot method for electrochemical glycosylation, which involves anodic oxidation of thioglycosides to generate glycosyl cation equivalents followed by their reactions with glycosyl acceptors, has been developed. 相似文献
174.
S. Nezu S. Walsh V. Meille M. Yoshida J. B. Lando 《Journal of polymer science. Part A, Polymer chemistry》1995,33(6):973-977
The dimer, trimer, and tetramer of 1,11-dodecadiyne, HC?C? (CH2)8? C?CH, were synthesized. The solid-state polymerization of the dimer was investigated by infrared (IR) spectroscopy. IR bands due to the diacetylene moiety were identified through the comparison of the IR spectra of the dimer, trimer, and tetramer. The dimer was found to have two polymorphs, melt-crystallized and solution-crystallized. Both of the polymorphs undergo solid-state polymerization by exposure to γ-ray or UV irradiation. The former has higher polymerizability for the diacetylene moiety than the latter. The solid-state polymerization of the terminal acetylene group was not observed. It is shown that the previously reported dimer structure in which both the diacetylene and terminal acetylene groups are polymerized to form an inherently electrically conducting polymer is incorrect. © 1995 John Wiley & Sons, Inc. 相似文献
175.
Kiyoshi Hasebe Satoshi Hikima Hitoshi Yoshida 《Fresenius' Journal of Analytical Chemistry》1991,339(4):261-263
Summary The covalent bonding of l-lactate oxidase (no E.C.) to cross-linked copolymers of chitosan (Chitopearl) using the glutaraldehyde method is described and applied to the determination of l-lactate in serums of diseased and normal animals. The bioreactor packing of the immobilized enzyme is stable for at least 4 months and can be continuously used for the rapid and simple determination of l-lactate. The reduction current of pyruvate, corresponding to the product of enzymatic reaction, is determined by differential pulse polarography. The reproducibility (RSD) for 10 mol/l l-lactate is 0.78% (n=6) and the detection limit is 0.62 mol/l (k=2, confidence level 97.72%). 相似文献
176.
177.
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179.
Straub PB Jaffe DE Glass HD Adams MR Brown CN Charpak G Cooper WE Crittenden JA Finley DA Gray R Hemmi Y Hsiung YB Hubbard JR Jonckheere AM Jöstlein H Kaplan DM Lederman LM Luk KB Maki A Mangeot P McCarthy RL Miyake K Plaag RE Rutherfoord JP Sakai Y Santiard JC Sauli F Smith SR Yoshida T Young KK 《Physical review letters》1992,68(4):452-455
180.
Konarev DV Khasanov SS Otsuka A Yoshida Y Saito G 《Journal of the American Chemical Society》2002,124(26):7648-7649
The ionic multicomponent complex complex: ([Cr(I)(PhH)(2)].+))(2)[Co(II)TPP(C(60)(CN)(2))]-[C(60)(CN)(2)](.-).3(o-C(6)H(4)Cl(2)) (Co(II)TPP: cobalt (II) tetraphenylporphyrin; Cr(PhH)(2): bis(benzene)chromium; o-C(6)H(4)Cl(2): o-dichlorobenzene) containing CoTPP(C(60)(CN)(2)- anion and C(60)(CN)(2).- radical anion was obtained. The complex has the cage structure with channels, which accommodate Cr(I)(PhH)(2)(.+) and o-C(6)H(4)Cl(2) molecules. For the first time the sigma-bonding of Co(II)TPP to the fullerene radical anion with the essentially shortened Co.C(C(60)(CN)(2)) contact of 2.282 A is observed. The sigma-bonding results in the diamagnetism of Co(II)TPP(C(60)(CN)(2))(-) anion. The nonbonded C(60)(CN)(2)(.-) radical anion retains both the C(2)(v)symmetry and the shape of the molecule. The length of the C(triple bond)N bonds is 1.141 and 1.152 A. 相似文献