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1.
Srivastava JN  Singh RP 《Talanta》1973,20(11):1210-1213
Thiotropolone forms chloroform-soluble reddish-brown and violet complexes with cobalt(II) and nickel(II), in the pH range 7.0-8.5 and 6.0-9.0 respectively. Based on this, a sensitive and rapid method for the spectrophotometric determination of traces of cobalt and nickel in metals and alloys has been developed. The two metals can be determined accurately in the range 0.6-2.6 ppm of cobalt and 0.75-4.57 ppm of nickel, simultaneously.  相似文献   

2.
The reagent 3,8,13,18-tetramethyl-21H,23H-porphine-2,7,12,17-tetrapropionic acid or coproporphyrin-I (CPI) was used for the spectrophotometric determination of copper(II) and cobalt(II) in the presence of pyridine and imidazole catalysts. Optimum conditions were investigated and the methods were applied to the determination of parts per billion levels of copper(II) and cobalt(II). The Sandell sensitivities of the recommended procedures were 0.568 μm cm−2 and 0.464 μg cm−2 (for A = 0.001) for copper and cobalt, respectively. The relative standard deviations were 2.0% for copper and 1.0% for cobalt. The kinetics of the reaction of CPI with copper(II) and cobalt(II) in the presence of the catalysts and the influence of the temperature were studied, and their kinetic constants determined.The influence of light on the photodecomposition of CPI was also studied.  相似文献   

3.
Zusammenfassung Die synergistische Extraktion von Eisen(II)-, Cobalt(II)- und Nickel(II)-Komplexen wird untersucht. Verwendet werden fluorierte Diketone (A) (Derivate des Thenoyltrifluoracetons) und eine neue Gruppe Schiff' scher Basen. Aus den Extraktionskurven nach der Job- und Molar-Ratio-Methode, der Elementaranalyse und aus Molmassenbestimmungen werden Komplexverbindungen der Zusammensetzung [M4A8B4] nachgewiesen. Aus den Elektronen- und IR-Spektren und aus magnetischen Messungen wird für die Ni(II)-Komplexe eine octaedrische Struktur vorgeschlagen.
Preparation and structure analysis of new iron(II), cobalt(II) and nickel(II) complexes by synergistic extraction
Summary The synergistic extraction of iron(II), cobalt(II) and nickel(II) complexes was investigated. Fluorinated diketones (A) (derivates of thenoyltrifluoracetones) and a new group of Schiff bases were used. By Job and molar-ratio method investigation on the extraction curves, by elementary analysis and molar mass detection, complex compounds of the composition [M4A8B4] could be proved. Electron and infrared spectra and magnetical measurements led to an octahedral structure proposal for the Ni(II)-complexes.
Mein Dank gilt besonders Herrn Professor Dr. H. Specker, Direktor des Instituts für Anorganische Chemie I der RUB, für die Zurverfügungstellung der Geräte und Chemikalien, Herrn Professor Dr. Metfessel und Frau Dr. Magdela Gronau für die magnetischen Messungen in der Abteilung Physik der RUB.  相似文献   

4.
Schiff-base complexes of cobalt(II), nickel(II), copper(II) and, zinc(II) with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, 1H- and 13C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). A tetrahedral geometry has been assigned to the complexes.  相似文献   

5.
Tri-nuclear cobalt and nickel complexes ([(CoL)2(OAc)2Co]?·?THF (I) and [(NiL)2(OAc)2(THF)2Ni]?·?THF (II)) have been synthesized by reaction of a new Salen-type bisoxime chelating ligand of 2,2′-[ethylenedioxybis(nitrilomethylidyne)]dinaphthol(H2L) with cobalt(II) acetate tetrahydrate or nickel(II) acetate tetrahydrate, respectively. Complexes I and II were characterized by elemental analyses, IR, TG-DTA and 1H-NMR etc. The X-ray crystal structures of I and II reveal that two acetate ions coordinate to three cobalt or nickel ions through M–O–C–O–M (M?=?Co or Ni) bridges and four μ-naphthoxo oxygen atoms from two [ML] units also coordinate to cobalt(II) or nickel(II). Complex I has two distorted square-pyramidal coordination spheres and an octahedral geometry around Co1. In complex II all three nickel ions are six-coordinate.  相似文献   

6.
《Analytical letters》2012,45(8):2021-2031
Abstract

The preferential complexing tendency of different nietal ions towards chelating agents anchored on a polymer has been used for separation of transition metals. the anthranilic acid group was anchored on the polymeric cellulose back-bone by successive coupling with trifunctional reagent cyanuric chloride, in diozane medium, at pH 7 and 9–10, respectively. This polymer bound chelating agent was used to separate copper(II), nickel(II) and cobalt(II) in the concentration range 1.0–0.1 mmol/L. the separation of a mixture of two components was quantitative using column chromatography.  相似文献   

7.
Khuhawar MY  Lanjwani SN 《Talanta》1998,46(4):485-490
The complexing reagent 2-thiophenaldehyde-4-phenyl-3-thiosemicarbazone (TAPT) was examined for high performance liquid chromatographic (HPLC) separations of cobalt(II), copper(II) and iron(II) or cobalt(II), nickel(II), iron(II), copper(II) and mercury(II) as metal chelates on a Microsorb C-18, 5-mum column (150x4.6 mm i.d.) (Rainin Instruments Woburn, MA, USA). The complexes were eluted isocratically with methanol:acetonitrile:water containing sodium acetate and tetrabutyl ammonium bromide (TBA). UV detection was at 254 nm. The solvent extraction procedure was developed for simultaneous determination of the metals, with detection limits within 0.5-2.5 mug ml(-1) in the final solution. The method was applied for the determination of copper, cobalt and iron in pharmaceutical preparation.  相似文献   

8.
Nickel(II) and cobalt(II) bis-chelates of methyl(2-aminocyclopentene-1-dithiocarboxy)-S-acetate (ACDASAMe) were synthesized and characterized by spectroscopic methods and in the case of the nickel complex, X-ray single-crystal diffraction. The ligand exhibits the (N, S) coordination mode on interacting with the metal centers. The X-ray structure of the nickel(II) complex reveals a NiN2S2 distorted square planar coordination geometry with the ligands showing a cis configuration. There is no interaction between the –CH2COOMe moieties of the ligand and the metal center, however intermolecular hydrogen bonds through the carbonyl group leads to the building of dimeric associations.  相似文献   

9.
This works reports the use of square-wave adsorptive stripping voltammetry (SWAdSV) for the simultaneous determination of Ni(II) and Co(II) on a rotating-disc bismuth-film electrode (BFE). The metal ions in the non-deoxygenated sample were complexed with dimethylglyoxime (DMG) and the complexes were accumulated by adsorption on the surface of the BFE. The stripping step was carried out by using a square-wave potential-time voltammetric excitation signal. Electrochemical cleaning of the bismuth film was employed, enabling the same bismuth film to be used for a series of measurements. The experimental variables (choice of the working electrode substrate, the presence of oxygen, the DMG concentration, the buffer concentration, the preconcentration potential, the accumulation time, the rotation speed and the SW parameters) as well as potential interferences were investigated and the figures of merit of the methods were established. Using the selected conditions, the 3σ limits of detection were 70 ng l−1 for Co(II) and 100 ng l−1 for Ni(II) (for 300 s of preconcentration) and the relative standard deviations were 2.3% for Co(II) and 3.9% for Ni(II) at the 2 μg l−1 level (n = 8). Finally, the method was applied to the determination of nickel and cobalt in real samples with satisfactory results.  相似文献   

10.
Zusammenfassung Die synergistische Extraktion von Eisen(II)-, Cobalt(II)- und Nickel(II)-Komplexen wird untersucht. Verwendet wurden fluorierte Diketone (A) (Hexafluoroacetylaceton und Derivate des Thenoyltrifluoracetons) und Abkömmlinge des Pyridinal(2)-phenylimins und des Bis-(pyridinal-2-)-diimines (B). Aus den Extraktionskurven nach der Job- und der Molar-Ratio-Methode, der Elementaranalyse und aus Molmassenbestimmungen werden Komplexverbindungen der Zusammensetzung [MA2B1], [M2A4B2] und [M3A6B3] nachgewiesen. Aus den Elektronen- und IR-Spektren und aus magnetischen Messungen wird für die Ni(II)-Komplexe eine octaedrische Struktur vorgeschlagen.
Investigation and structure analysis of iron(II), cobalt(II) and nickel(II) complexes after synergistic extraction
Summary The synergistic extraction of iron(II), cobalt(II) and nickel(II) complexes was investigated. Fluorinated diketones (A) (hexafluoroacetylacetone and derivatives of thenoyltrifluoracetones) and derivatives of pyridinale(2)-phenylimine and bis(pyridinale-2-)diimine (B) were used. By Job and molar-ratio investigation on the extraction curves, by elementary analysis and molar mass detection complex compounds of the composition [MA2B1], [M2A4B2] and [M3A6B3] could be proved. Electron and infrared spectra and magnetical measurements led to an octahedral structure proposal for the Ni(II)-complexes.
Wir danken Herrn Dr. Bodo Plewinsky, Institut für Anorganische Chemie der FU Berlin, sehr herzlich für die Bestimmung der Molmassen mit der Ultrazentrifuge.  相似文献   

11.
A chiral Schiff base complex, bis(N-R-1-phenylethyl-3,5-dichlorosalicydenaminato) cobalt(II) was prepared newly and characterized to be a distorted tetrahedral trans-[CoN2O2] coordination geometry. Organic/inorganic hybrid materials containing the related cobalt(II), nickel(II), copper(II), and zinc(II) complexes and photochromic azobenzene in polymethylmethacrylate (PMMA) cast films were assembled for comparison of their flexibility and molecular arrangement in the photofunctional medium. Characterization of each component and hybrid materials was carried out by means of absorption and CD spectra and thermal analysis (TG–DTA and DSC). Moreover, we have attempted to observe changes of conformation and/or molecular arrangement of the complexes or azobenzene induced by cistrans photoisomerization of azobenzene after alternate irradiation of polarized UV and visible light. Gradual increase of optical anisotropy was observed for all the hybrid materials regardless of flexibility of Schiff base complexes, and the degree of dichroism and weak intermolecular interactions were discussed based on polarized absorption electronic spectra.  相似文献   

12.
The tris(2,2′-bipyridine)cobalt(II) complex gives a reversible d.c. wave with E12 = ?1.02 V vs. SCE and a sharp differential pulse peak at Ep = ?1.03 V in a salted-out acetonitrile phase. A simple selective method is described for the determination of cobalt(II); down to 0.25 μg of cobalt(II) can be determined in presence of large amounts of Ni, Zn, Cd, Pb, and Cu; iron(III) can be masked with sodium fluoride. The method is applicable to the determination of >0.0l% cobalt in nickel salts and >5 × 10?5% cobalt in iron salts. Nickel(II) can also be extracted from aqueous solution and determined by differential pulse polarography, even in presence of a 20-fold amount of cobalt(II) by masking with EDTA; >0.01% of nickel in cobalt salts can be determined reproducibly.  相似文献   

13.
An extraction-spectrophotometric method is described for the determination of traces of iron(II) with 2-[2-(3,5-dibromopyridyl)azo]-5-diethyl-aminobenzoic acid. The reagent forms a stable and blue 12 iron/reagent complex that can be extracted into chloroform. The apparent molar absorptivity of the iron(II) complex is 1.09 × 105 1 mol–1 cm–1 at 624 nm in chloroform. The reagent is relatively selective; interferences from cobalt, copper, nickel and vanadium can be removed by using dimethylglyoxime and EDTA. The method is applied to the determination of iron (II) in sea water and aluminium alloys with good precision and accuracy.  相似文献   

14.
Mononuclear copper(Ⅱ), nickel(Ⅱ) and cobalt(Ⅲ) tetracoordinate macrocyclic complexes were synthesized and spectroscopically characterized. The crystal structure of the three compounds were determined by X-ray crystallography. The electrochemical experimental results indicate that the three complexes could interact with DNA mainly by electrostatic interaction. The interaction of tetracoordinate macrocyclic cobalt(Ⅲ) complex with DNA was studied by cyclic voltammetry and UV-vis spectroscopy. The experimental results reveal that tetracoordinate macrocyc- lic cobalt(Ⅲ) complex could interact with DNA by electrostatic interaction to form a 1 : 1 DNA association complex with a binding constant of 7.50 ×10^3 L·mol^-1.  相似文献   

15.
《Analytical letters》2012,45(9):1379-1398
Abstract

A FIA assembly producing a carrier with pH which can be adjusted to the desired pH value is propposed. It is based on the merging of two different solutions, one of them at constant flow-rate and the other at variable flow-rate. This manifold has been used for the simultaneous determination of Bi(III) and Pb(II) with Arsenazo III. Calibration curves are linear in the 1.0-11.0 ppm Bi (III) range at pH 0.25 and 1.0-12.1 ppm Pb (II) at pH 2.15. The effect of foreign ions is also reported.  相似文献   

16.
A convenient and efficient method for the estimation of cobalt(II) ions in the presence of other metal ions is described. Interference of metal ions such as iron(II), iron(III), nickel(II), manganese(II), and copper(II) have been investigated. Only iron(III) ions seriously affect this determination. Copper(II) and nickel(II) ions do not interfere if present in a molar-ratio less than 1:2 in the cobalt(II) ion solution. Cobalt(II)-nickel(II) and cobalt(II)-copper(II) binary mixtures can be efficiently analyzed at selective wavelengths.  相似文献   

17.
Reddy KH  Prasad NB  Reddy TS 《Talanta》2003,59(3):425-433
The analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemi-carbazone (PPDOT) are described for the first time. The reagent gives colour reactions with copper(II) and nickel(II) in sodium acetate-acetic acid buffer medium. The copper complex shows maximum absorbance at 465 nm while the nickel complex at 395 nm. Therefore, these colour reactions have been advantageously used for the simultaneous spectrophotometric determination of copper(II) and nickel(II) in synthetic mixture and also in edible oils and seeds.  相似文献   

18.
The cobalt(II) and nickel(II) chelates of Schiff bases, derived by condensing 4-butyryl-3-methyl-1-phenyl-2-pyrazolin-5-one (BMPP) with o-, m-, p-phenylenediamine, benzidine, and ethylenediamine have been synthesized and characterized by elemental analyses, thermogravimetric analyses (TGA), conductance data, magnetic measurements, IR, 1H NMR, 13C NMR, mass, and electronic spectroscopies. Each of the Schiff bases was an ONNO donor to metal forming chelates formulated as [M(L)(H2O)2] n with M = Ni(II) and Co(II) and L is the di-anion of the Schiff base. The monomeric (n = 1) and dimeric (n = 2) species of these metal chelates, based on available evidence, are suggested.  相似文献   

19.
A partial least squares (PLS-1) calibration model based on kinetic—spectrophotometric measurement, for the simultaneous determination of Cu(II), Ni(II) and Co(II) ions is described. The method was based on the difference in the rate of the reaction between Co(II), Ni(II) and Cu(II) ions with 1-(2-pyridylazo)2-naphthol in a pH 5.8 buffer solution and in micellar media at 25°C. The absorption kinetic profiles of the solutions were monitored by measuring the absorbance at 570 nm at 2 s intervals during the time range of 0–10 min after initiation of the reaction. The experimental calibration matrix for the partial least squares (PLS-1) model was designed with 30 samples. The cross-validation method was used for selecting the number of factors. The results showed that simultaneous determination could be performed in the range 0.1-2 μg mL−1 for each cation. The proposed method was successfully applied to the simultaneous determination of Cu(II), Ni(II) and Co(II) ions in water and in synthetic alloy samples.   相似文献   

20.
Y. Zhao 《Chromatographia》2000,51(3-4):231-234
Summary A new chelating reagent 2-thiophenaldehyde-4-phenyl-3-thiosemicarbazone (TAPT) has been examined for high performance liquid chromatographic (HPLC) separations of cobalt (II), copper(II) and iron (II) or cobalt (II), nickel (II), iron (II), copper (II) and mercury (II) as metal chelates on a C18, 5μm column (250×4 mm i.d.) The chelates were eluted isocratically with methanol: acetonitrile: water containing sodium acetate and tetrabutylammonium bromide (TBA), and detected at 254 nm. A solvent extraction procedure was developed for simultaneous determination of the metals with detection limits within 0.02–2.5 μ g.mL−1. The method was applied to the determination of copper, cobalt and iron in natural waters.  相似文献   

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