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111.
K L Madhok 《Journal of Chemical Sciences》1982,91(2):165-171
Nicke(II) chloride reacts with N,N′-diarylformamidino-N′-arylcarbamides thiocarbamides and N-benzoylformamidino-N′-arylcarbamides,
thiocarbamides forming complexes of the general formula [Ni (Ar.NH.C (NH) NH.C.X. NH.R)2] Cl2 (R=phenyl, orthotolyl and paratolyl; Ar=benzoyl; X=S,O) and [Ni (R.NH.C.X.NH.C (N.Ph.).NH.Ph.)2] Cl2 (R=phenyl, orthotolyl, paratolyl; Ph=phenyl; X=S, O). The ligands when oxidized with iodine undergo ring closure to related
3,5-diarylamino 1,2,4-thiadiazolidines and 3,5-diarylamino-1,2,4-diazolidines, while the complexes are not susceptible to
oxidation. This confirms the binding in complexes is through sulphur and oxygen of the ligands. 相似文献
112.
113.
The electrocatalytic oxidation of hydrazine at the aluminum electrode, modified by electroless deposition of nickel pentacyanonitrosylferrate
(NiPCNF) on the surface of the electrode has been studied by cyclic voltammetry, chronoamperometry and rotating disk electrode
voltammetry and the kinetics of the catalytic reaction were investigated. The results were explained using the theory of electrocatalytic
reactions at chemically modified electrodes. It was found that a one-electron charge-transfer process is rate limiting and
that the average values of the rate constant for the catalytic reaction and the diffusion coefficient, evaluated by different
approaches, are 5.2×103 M–1s–1 and 8.5×10–6 cm2s–1, respectively. Further examinations of the modified electrodes show that the modifying layers (NiPCNF) on the aluminum substrate
have reproducible behavior and a high level of stability, after exposing them in air and hydrazine solutions for a long time.
Electronic Publication 相似文献
114.
Veronika Gemmer-Colos und Rolf Neeb 《Fresenius' Journal of Analytical Chemistry》1978,293(4):290-294
Zusammenfassung Kleine Mengen Ni, Cu und Zn in wäßrigen Lösungen können nach Ausschütteln ihrer Dipropyldithiocarbamatochelate gas-chromatographisch bestimmt werden. Arbeitsbedingungen für den 0,01–1 ppm-Bereich werden angegeben. Die Reproduzierbarkeit der Bestimmung wird durch Zusatz eines inneren Standards verbessert.
Dialkyldithiocarbamates as reagents for the gas-chromatographic determination of metalsII. Determination of zinc, copper and nickel as dipropyldithiocarbamato chelates after extraction from aqueous solution
Summary Small amounts of Ni, Cu and Zn in aqueous solutions can be determined by gas chromatography after extraction of their dipropyldithiocarbamatochelates. Working details for the 0.01–1 ppm range are reported. Reproducibility is markedly improved by addition of an inner standard.
Die Untersuchungen wurden in dankenswerter Weise durch Mittel der Deutschen Forschungsgemeinschaft und des Verbands der chemischen Industrie unterstützt. 相似文献
115.
氢化物发生石墨炉原位富集直接测定高温镍基合金中碲 总被引:5,自引:0,他引:5
通过选择碲的氢化物发生条件,克服了高含量镍对碲的干扰,把氢化物富集在涂钯石墨管里,然后再原子化,成功地测定了高温镍基合金中碲。 相似文献
116.
M.?H.?Pournaghi-AzarEmail author H.?Nahalparvari 《Journal of Solid State Electrochemistry》2004,8(8):550-557
The use of a zinc substrate as an electrode and the modification of its surface by means of a thin film of platinum-doped nickel hexacyanoferrate (Pt-NiHCF) were developed. The modification conditions of the zinc surface including the electroless deposition of metallic nickel on the electrode surface from NiCl2 solution, chemical derivatization of the deposited nickel to the NiHCF film in 0.5 M K3[Fe(CN)6] solution, and electrochemical penetration of metallic platinum into the modified film are described. The modified zinc electrodes prepared under optimum conditions show a well-defined redox couple due to the [NiIIFeIII/II(CN)6]1–/2–
system. The effects of pH, the alkali metal cation, and the anion of the supporting electrolyte on the electrochemical characteristics of the modified electrode were studied in detail. The diffusion coefficients of hydrated alkali metal cations in the film (D), the transfer coefficient (), and the transfer rate constant for the electron (ks) were calculated in the presence of some alkali metal cations. The electrocatalytic activity of the modified electrode for methanol oxidation was demonstrated. The stability of the modified electrode under various experimental conditions was investigated. 相似文献
117.
118.
Much improved catalytic carbon-carbon bond-forming reactions between aryl chlorides and Grignard reagents has been achieved using nickel(II) ion on nanoporous carbon. 相似文献
119.
Valente Gómez-Benítez 《Tetrahedron letters》2006,47(29):5059-5062
[NiCl{C6H3-2,6-(OPPh2)2}] efficiently catalyzes the thiolation of iodobenzene with a broad scope of disulfides in the presence of zinc, the coupled products are obtained in excellent and in many cases nearly quantitative yields. 相似文献
120.
Margarida Maria Correia dos Santos Sheila Alves Maria de Lurdes Simões Gonçalves 《Electroanalysis》2007,19(22):2351-2361
The kinetics of formation and dissociation of Ni(II) complexes with oxalic and citric acids was studied by cyclic voltammetry in model solutions of xylem sap of Q. ilex (the dominant tree growing on serpentine soils of Northeast Portugal) using representative concentrations, pH and ionic strength. The role of magnesium on complex formation was analyzed from solutions where Mg is present at concentration levels found in the xylem sap of Q. ilex growing on both nonserpentine and serpentine soils. Kinetics studies were also done in diluted solutions of real xylem sap samples, spiked with increasing amounts of magnesium. The values obtained for the apparent rate constants were those anticipated by the proposed model. To test the validity of the methodology and mechanisms, formation rate constants, kf (M?1 s?1) of Ni(II) complexes with citrate and oxalate were evaluated that compare with the values from Eigen mechanism. 相似文献