Multielement trace determinations in A12O3 ceramic powders by inductively coupled plasma mass spectrometry with special reference to on-line trace preconcentration

The use of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace elements in Al₂O₃ powders is reported. Special interest is given to a preconcentration of the trace elements by on-line coupling of chromatography to ICP-MS. This is based on the complexation of Co, Cu, Cr, Fe, Ga, Mn, Ni, V and Zn with hexamethylene-dithiocarbamate (HMDC), their preconcentration on a C18 RP column by reversed phase liquid chromatography and their elution with CH₃OH-H₂O mixtures. A direct coupling of the HPLC system to the ICP-MS has been realized by high pressure pneumatic nebulization using desolvation. With the Chromatographie method developed, removal of the AI by at least 99% was achieved. For the trace elements V, Fe, Ni, Co, Cu and Ga, high and reproducible recoveries (ranging from 96–99%) were reached. The method developed has been shown to considerably enhance the power of detection as compared with direct procedures, namely down to 0.02–0.16 ( for V and Fe, respectively. The possibilities of the method are shown by the determinations of V, Mn, Fe, Ni, Co, Cu, Zn and Ga at the μg/g level in A1₂O₃ powders. The accuracy of the method at the 0.06 to 9.0 level for Co and Fe, respectively, is demonstrated by a comparison with results of independent methods from the literature.     

Spectrophotometric and conductometric study of complexation of salophen and some transition metal ions in nonaqueous polar solvents

The complexation reaction between Cu(2+), Co(2+) and Ni(2+) metal cations with N,N'-bis(salicylidene)-1,2-phenylenediamine (salophen), in three nonaqueous polar solvents such as: acetonitrile (AN), dimethyl sulfoxide (DMSO), methanol (MeOH) and two binary mixtures of AN:DMSO and AN:MeOH at 25 degrees C were studied by spectrophotometric and conductometric methods. All investigated metal ions form 1:1 ML complex which their stability constants were determined and increase as Irving-Williams stability order of Co(2+)相似文献   

AAS determination of Co, Ni, Mn and Cr in ores, concentrates and dusts from copper metallurgy after matrix elements separation by extraction

Summary A method has been developed for the AAS determination of Co, Ni, Mn and Cr in ores, concentrates and dusts of copper metallurgy at the 10^–3–10^–1% level. The matrix elements (Cu, Pb, Zn, Fe) were separated in a two-stage extraction: with MIBK from 6 M HCl solution and with 0.1 M tetrahexylammonium iodide (THAI) in MIBK from 3 M HCl, in form of ion-pairs, without Co, Ni, Mn and Cr losses. Values of r.s.d. were 2.0–6.0%.

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AAS-Bestimmung von Co, Ni, Mn und Cr in Erzen, Konzentraten und Stäuben aus dem Bereich der Kupfermetallurgie nach Abtrennung der Matrixelemente durch Extraction

Zusammenfassung Das beschriebene Verfahren eignet sich für den Bereich von 10^–3 bis 10^–1%. Die Matrixelemente (Cu, Pb, Zn, Fe) wurden als Ionenpaare ohne Verluste an Co, Ni, Mn und Cr mit Hilfe einer zweistufigen Extraktion abgetrennt: mit MIBK aus 6 M HCl-Lösung und mit 0,1 M Tetrahexylammoniumiodid (THAI) in MIBK aus 3 M HCl-Lösung. Die relativen Stadardabweichungen lagen im Bereich von 2,0 bis 6,0%.

     

Synthesis and spectrophotometric study of 2-[2-(3,5-dibromopyridyl,)azo] -5-dimethylaminobenzoic acid as an analytical reagent: Determination of nickel

2-[2-(3,5-Dibrornopyridyl)azo]-5-dimethyIam;nobenzoic acid (3,5-diBr-PAMB) has been synthesized and its potential for the spectrophotometric determination of metals studied. It reacts sensitively with nickel, cobalt, iron and copper, and is particularly useful for nickel. The apparent molar absorptivity in chloroform is 1.50 × 10⁵ l mol^-1 cm^-1 and the Sandell sensitivity is 0.4 ng Ni cm^-2. Nickel reacts with 3.5-diBr-PAMB at pH 4–10; at pH 4–7 the complex can be extracted into chloroform to give a stable purple solution. The optimal calibration range is 0.04–0.4 ppm Ni. Only Cu, Co, Fe, Pd and V interfere seriously but Pd, Cu and V can be masked by thiourea.     

Chemical separation and electrothermal atomic-absorption spectrophotometric determination of Cd, Co, Cu and Ni in high-purity uranium

Summary An electrothermal atomic-absorption spectrophotometric method has been developed for the estimation of trace concentrations of Cd, Co, Cu and Ni in high-purity uranium after their chemical separation. The trace constituents from 100 mg of uranium sample in 3 M nitric acid solution were separated using 0.2 M di-n-octyl sulphoxide in xylene. The concentration of the analytes in the aqueous phase was determined by graphite furnace AAS. The detection limits were 0.001, 0.01, 0.025 and 0.05 ng for Cd, Co, Cu and Ni, respectively. The precision of the determinations was 7–14%. The effect on absorbances of the analytes due to the presence of Al, Ca, Fe, Mg, Pb, W and uranium was examined.

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Chemische Abtrennung und elektrothermische AAS-Bestimmung von Cd, Co, Cu und Ni in hochreinem Uran

Zusammenfassung Die Spuren werden aus einer 100 mg Uranprobe in 3 M salpetersaurer Lösung durch Extraktion des U mit Hilfe von 0.2 M Di-n-octylsulfoxid im Xylol abgetrennt und werden anschließend in der wäßrigen Phase durch Graphitofen-AAS bestimmt. Die Nachweisgrenzen betragen 0,001 ng (Cd), 0,01 ng (Co), 0,025 ng (Cu) und 0,05 ng (Ni). Die Reproduzierbarkeit beträgt 7–14%. Der Einfluß von Al, Ca, Fe, Mg, Pb, W sowie Resturan auf die Absorption der analysierten Elemente wurde untersucht.

     

Synthesis and characterization of azo sulfaguanidine complexes and their application for corrosion inhibition of silicate glass

A new azo dye ligand of sulfaguanidine with 5‐nitro‐8‐hydroxyquinoline and its Mn(II), Ni(II), Co(II) and Cu(II) complexes were synthesized and characterized using elemental analysis, inductively coupled plasma, molar conductance, X‐ray powder diffraction, thermogravimetric analysis, magnetic moment measurements, and infrared, ¹H NMR, electron impact mass and UV–visible spectral studies. The spectral studies and analytical data revealed that the azo dye ligand acts as a monobasic bidentate ligand via deprotonated OH and nitrogen atom of the azo group. The data support the mononuclear formulation of all complexes, except Cu(II) complex that has a binuclear formulation with a 1:2 metal to ligand ratio. The complexes have tetrahedral structure except Ni(II) which has octahedral geometry. The molar conductance data reveal that all the metal complexes are non‐electrolytic in nature The average particle size of the ligand and its Mn(II), Ni(II), Co(II) and Cu(II) complexes is 0.12–0.91 nm. The effect of these compounds for improvement of chemical durability of silicate glass in 0.1 M HCl was studied. Window and soda‐lime silica glass were taken as samples for the durability experiments. The inhibition efficiency of the ligand and its complexes for corrosion of glass surfaces after dissolution experiments was evaluated quantitatively using the specific weight loss method and qualitatively using scanning electron microscopy. The inhibition efficiencies of the tested compounds follow the order Co(II) complex > Mn(II) complex > Ni(II) complex > H₃L > Cu(II) complex. The chemical durability improvement is 88.12–56.25% and 87.99–51.96% for window and soda‐lime silica glass, respectively. Copyright © 2016 John Wiley & Sons, Ltd.     

Electrospray ionization studies of transition-metal complexes of 2-acetylbenzimidazolethiosemicarbazone using collision-induced dissociation and ion-molecule reactions

The complexes of transition-metal ions (M2+, where M = Fe, Co, Ni, Cu, Zn, Cd, and Hg) with 2-acetylbenzimidazolethiosemicarbazone (L) are studied under electrospray ionization (ESI) conditions. The ESI mass spectra of Fe and Co complexes showed the complex ions corresponding to [M+2L-2H]+, and those of Ni and Zn complexes showed [M+2L-H]+ ions, wherein the metal/ligand ratio is 1:2 and the oxidation state of the central metal ion is +3 in the case of Fe and Co and +2 in the case of Ni and Zn. The Cd and Cu complexes showed preferentially 1:1 complex ions, i.e., [M+L-H]+ or [M+L+Cl]+, whereas Hg formed both 1:1 and 1:2 complex ions. During formation of the above complex ions one or two ligands are deprotonated after keto-enol tautomerism, depending on the nature and oxidation state of central metal ion. The structures and coordination numbers of the metal ions in the complex ions were studied by their collision-induced dissociation spectra and ion-molecule reactions with acetonitrile or propylamine in the collision cell. Based on these results it is concluded that Fe, Co, Ni and Zn form stable octahedral complexes, whereas tetrahedral or square planar complexes are formed preferentially for other metals. In addition, the Cu complex showed a [2L+2Cu-3H]+ ion with a Cu-Cu bond.     

The flame photometric determination of Fe,Ni, Co,Cu, Mn,Cr, and Al in waters

Summary A method for the flame photometric determination of Fe, Ni, Co, Cu, Mn, Al, and Cr in various waters is described. Samples can be analysed directly after removal of interfering anions or after separation (and concentration) of the elements to be determined from any interfering cations. Fe, Ni, Co, and Cu are extracted as carbamates, Al as cupferronate, and Cr as the ion-association complex HCrO₃Cl. The extractant used for all is hexone.The elimination of the interference of Mg with Fe is discussed. The variation of the relative error of the emission measurement with the concentration of the elements was investigated.

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Zusammenfassung Eine Methode zur flammenphotometrischen Bestimmung von Fe, Ni, Co, Cu, Mn, Al und Cr in Wässern wurde beschrieben. Nach Entfernung der störenden Anionen oder nach Abtrennung (und Anreicherung) der zu bestimmenden Elemente von etwa störenden Kationen können die Proben direkt analysiert werden. Fe, Ni, Co und Cu werden als Carbamate extrahiert, Al als Cupferronat und Cr in Form des Ionen-Assotiationskomplexes HCrO₃Cl. Als Extraktionsmittel dient in allen Fällen Hexon.Die Beseitigung des störenden Einflusses von Magnesium bei der Eisenbestimmung wurde diskutiert. Die Variation des relativen Fehlers der Emissionsmessung mit der Konzentration der Elemente wurde untersucht.

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Résumé On décrit une méthode pour le dosage par photométrie de flamme du Fe, Ni, Co, Cu, Mn, Al et Cr dans des eaux variées. On peut faire l'analyse directe après élimination des anions qui interfèrent ou après séparation (et concentration) des éléments à doser d'avec les cations gênants. On extrait Fe, Ni, Co et Cu sous forme de carbamates, Al en cupferronate, et Cr à l'état de complexe par association ionique, HCrO₃Cl. Dans tous les cas, on utilise l'hexone comme agent d'extraction.On discute l'élimination de l'interférence du Mg par le Fe. On a suivi la variation de l'erreur relative dans la mesure de l'émission en fonction de la concentration des éléments.

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Paper presented at the Symposium on Analytical Chemistry, Graz, 29th September–1st October 1965.     

Separation of antimony(III) with iodide and dithizone by sorption on polyurethane foam from sulphuric acid medium for its spectrophotometric determination in glasses

A method for quantitative separation of antimony(III) by sorption on polyether based polyurethane foam and its spectrophotometric determination has been described. The method involves formation of a pink-red complex of antimony(III) with iodide (0.045M) and dithizone (2.3 x 10(-5)M) in 0.25-0.75M H(2)SO(4) medium, sorption of the complex on polyurethane foam (within 45 min) at room temperature followed by its elution with acidified acetone (acetone containing 0.008% H(2)SO(4)) and spectrophotometric measurement at 507.2 nm ( = 2.56 x 10(4) l mol cm). The method obeys Beer's law from 0.1 to 6.0 mug antimony(III). Tolerance limits of other ions are Co (100 mug), Ni (100 mug), Fe (10 mug), Cu (0.5 mug), Sn (20 mug), Zn (100 mug), As (100 mug), Mn (200 mug), Pb (50 mug), Ti (100 mug), V (50 mug), etc. Interference by iron and copper have been eliminated by treating with KOH prior to the extraction of antimony. The method has been standardized with glass samples spiked with known amounts of antimony and applied to the determination of antimony in various glasses.     

Electrothermal atomic absorption spectrometric determination of cobalt, copper, lead and nickel traces in aragonite following flotation and extraction separation

A method of determination of Co, Cu, Pb and Ni in nanogram quantities from aragonite is presented. Flotation and extraction of Co, Cu, Pb and Ni is suggested as methods for elimination matrix interferences of calcium. The method of flotation is performed by iron(III) hexamethylenedithiocarbamate, Fe(HMDTC)(3), as a colloid precipitate collector. The liquid-liquid extraction of Co, Cu, Pb and Ni is carried out by sodium diethyldithiocarbamate, NaDDTC, as complexing reagent into methylisobutyl ketone, MIBK. The electrothermal atomic absorption spectrometry (ETAAS) is used for determination of analytes. The detection limits of ETAAS followed by flotation are: 7.8 ng.g(-1) for Co, 17.1 ng.g(-1) for Cu, 7.2 ng.g(-1) for Pb and 9.0 mug.g(-1) for Ni. The detection limits of ETAAS followed by extraction are found to be: 12.0 ng.g(-1) for Co, 51.0 ng.g(-1) for Cu, 24.0 ng.g(-1) for Pb and 21.0 ng.g(-1) for Ni.     

Extraction spectrophotometric method for determination of aluminium in silicates

A simple, rapid and sensitive method has been worked out for spectrophotometric determination of macro and micro amounts of alumina in ceramic raw materials and finished products, including glasses. The method is based on the extraction of aluminum oxinate into chloroform after masking of titanium with chromotropic acid and of iron with ascorbic acid and 1,10-phenanthroline or ferrocyanide at pH 5.2. The absorbance is measured at 385 nm. Interference by Cu, Zn, Cd, Ni and Co, when present, is overcome by stripping them as cyanide complexes by shaking the chloroform extract with potassium cyanide solution. Zr is masked with quinalizarin sulphonic acid and fluoride with BeSO(4).     

Phenoxo-bridged symmetrical homobinuclear complexes derived from an “end-off” compartmental ligand, 2,6- bis [5′-chloro-3′-phenyl- 1H -indole-2′-carboxamidyliminomethyl]-4-methylphenol

A compartment ligand 2,6-bis[5′-chloro-3′-phenyl-1H-indole-2′-carboxamidyliminomethyl]-4-methylphenol was prepared and homobinuclear phenol-bridged Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Hg(II), Fe(III), and Mn(II) complexes have been prepared by the template method using the precursors 2,6-diformyl-4-methylphenol, 5-chloro-3-phenylindole-2-carbohydrazide and metal chlorides in 1 : 2 : 2 ratio, respectively. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, NMR, FAB mass and ESR spectra, TGA, and powder XRD data. Cu(II), Co(II), Zn(II), Cd(II) and Hg(II) complexes exhibit square pyramidal geometry whereas Ni(II), Mn(II), and Fe(III) complexes are octahedral. Low magnetic moment values for Cu(II), Ni(II), Co(II), Fe(III), and Mn(II) complexes show antiferromagnetic spin-exchange interaction between two metal centers in binuclear complexes. The ligand and its complexes were tested for antibacterial activity against Escherichia coli and Staphyloccocus aureus, and antifungal activity against Aspergillus niger and Candida albicans.     

A new sensitive method for the spectrophotometric determination of molybdenum using 3-hydroxy-2-(2'-thienyl)-4H-chromen-4-one

A spectrophotometric method has been developed for the determination of Molybdenum (VI) using 3-hydroxy-2-(2'-thienyl)-4H-chromen-4-one as a complexing agent. The complex formed was dissolved in water in the presence of Triton X-100 and exhibits an absorption maximum at 410 nm. A large number of metal ions like Co(II), Ni(II), Mn(II), Cr(III), Zn(II), Cu(II), Hg(II), Bi(III), Fe(II), Fe(III), Zr(IV), V(V) can be tolerated at an appreciable concentrations. Molar absorptivity and Sandell's sensitivity of the method is 2.80 x 10(5) l mol-1cm-1 and 3.42 x 10(-4) micrograms cm-2, respectively. Beer's law is obeyed in the concentration range of 0.01-0.4 ppm Mo(VI). Aliquots containing 0.2 ppm of Mo(VI) give a mean absorbance of 0.56 with a relative standard deviation of 1.3%.     

Synthesis and Some Transformations of Complex Salts of Bis-o-dicarbollyliron(II), -cobalt(II), and -nickel(II)

The complex salts [(o-C2B9H11)2M³⁺]₂M'²⁺·4bipy, where M = Fe, Co, or Ni, M' = Fe, Co, Ni, Cu, Mn (M M'), and bipy is 2,2'-bipyridyl, were synthesized. The salts with M = Ni decompose to give 3-(2,2'-bipyridyl)-3,1,2-nickelacarborane, when refluxed in alcohol, and to give 2-(2,2'-bipyridyl)-2,1,7-nickel acarborane, when refluxed in dodecane (216°C).     

Determination of cadmium and lead at μg/1 levels in aqueous matrices by chelation ion chromatography

A method for the simultaneous determination of μg/1 or sub-μg/1 levels of cadmium and lead in sea water by chelation ion chromatography is demonstrated. The method consists in the preconcentration of a sea-water sample containing cadmium and lead on an iminodiacetate chelating resin; alkali and alkaline earth metals are removed from the resin with an ammonium acetate buffer, the metals are eluted and separated by cation-exchange chromatography, followed by postcolumn derivatization with 4-(2-pyridylazo)resorcinol and spectrophotometric detection at 520 nm. The concentration and separation steps are automated. The detection limit, when concentrating 200 ml of sea water, was found to be 2 ng for cadmium and 6 ng for lead. Relative standard deviations of 4.5% and 6.8% for 10 μg/1 of cadmium and lead, respectively, were obtained. Transition metals (Fe, Co, Ni, Zn, Cu, Mn) do not interfere in the analysis. An application of the method to the determination of cadmium and lead in sea-water samples collected in the Taranto gulf (Italy) is presented.     

Selective preconcentration, separation and speciation of ferric iron in different samples using N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane

The synthesis and analytical applications of N,N'-bis(2-hydroxy-5-bromo-benzyl)1,2 diaminopropane (HBDAP) are described. This compound reacts with Fe(III) in the range of pH 3-6 to produce a red complex (2:3 mol ratio of Fe(III)/HBDAP) soluble in chloroform. The investigation included a study of the characteristics that are essential for solvent extraction and for spectrophotometric determination and speciation of iron. A highly sensitive, selective and rapid spectrophotometric method is described for the determination of trace amounts of iron(III) by HBDAP. The complex obeys Beer's law from 0.056 to 1.68 mg l(-1) with an optimum range. The detection limit (taken as three times the standard deviation of the reagent blank) is approximately 1.23x10(-7) M Fe(III) and the limit of quantitation (taken as ten times the standard deviation of the reagent blank) is about 4.11x10(-7) M Fe(III). A single extraction gave a good separation of iron(III) from iron(II). Good separation of Fe(III) from Ni(II), Fe(II), Co(II), Cd(II), Mn(II), Zn(II), Pb(II) was also achieved at pH 3-5.     

Salisaldehyde-2-aminobenzimidazole schiff base complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)

New metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) with salicylidine-2-aminobenzimidazole (SABI) are synthesized and their physicochemical properties are investigated using elemental and thermal analyses, IR, conductometric, solid reflectance and magnetic susceptibility measurements. The base reacts with these metal ions to give 1:1 (Metal:SABI) complexes; in cases of Fe(III), Co(II), Cu(II), Zn(II) and Cd(II) ions; and 1:2 (Metal:SABI) complexes; in case of Ni(II) ion. The conductance data reveal that Fe(III) complex is 2:1 electrolyte, Co(II) is 1:2 electrolyte, Cu(II), Zn(II) and Cd(II) complexes are 1:1 electrolytes while Ni(II) is non-electrolyte. IR spectra showed that the ligand is coordinated to the metal ions in a terdentate mannar with O, N, N donor sites of the phenloic -OH, azomethine -N and benzimidazole -N3. Magnetic and solid reflectance spectra are used to infer the coordinating capacity of the ligand and the geometrical structure of these complexes. The thermal decomposition of the complexes is studied and indicates that not only the coordinated and/or crystallization water is lost but also that the decomposition of the ligand from the complexes is necessary to interpret the successive mass loss. Different thermodynamic activation parameters are also reported, using Coats-Redfern method. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis, crystal structures, and magnetic properties of cyano-bridged heterobimetallic chains based on [(Tp)Fe(CN)3]-

With the use of the tailored cyanometalate precursor, (Bu4N)[(Tp)Fe(CN)3] (Tp = Tris(pyrazolyl)hydroborate) as the building block to react with fully solvated Cu(II), Co(II), and Ni(II) cations, four one-dimensional (1D) heterobimetallic cyano-bridged chain complexes of squares, [(Tp)2Fe(III)2(CN)6Cu(CH3OH).2CH3OH]n (1), [(Tp)2Fe(III)2(CN)6Cu(DMF).DMF]n (2), [(Tp)2Fe(III)2(CN)6M(CH3OH)2.2CH3OH]n (M = Co (3) and Ni (4)), have been prepared. In complexes 1 and 2, the Cu(II) ions are pentacoordinated in the form of a slightly distorted square-based pyramid, and they are linked by distorted octahedrons of [(Tp)Fe(CN)3]- to form 1D chains of squares. In complexes 3 and 4, both the central Co(II) and Ni(II) ions have a slightly distorted octahedral coordination geometry, and they are bridged by [(Tp)Fe(CN)3]- to form similar 1D chains of squares. There are weak interchain pi-pi stacking interactions through the pyrazolyl groups of the Tp ligands for complexes 3 and 4. The crystal structures and magnetic studies demonstrate that complexes 1 and 2 exhibit intrachain ferromagnetic coupling and single-chain magnets behavior, and the blocking temperature is ca. 6 K for complex 1 and ca. 3 K for complex 2. Complexes 3 and 4 show significant metamagnetic behavior, where the cyanides mediate the intrachain ferromagnetic coupling between Fe(III) and Co(II) or Ni(II) ions and the interchain pi-pi stacking interactions lead to antiferromagnetic couplings. The field dependence of the magnetization measurements shows that the critical field is around 1 kOe for complex 3 and 0.8 kOe for complex 4 at 1.8 K.     

Surface layer-by-layer chemical deposition reaction for thin film formation of nano-sized metal 8-hydroxyquinolate complexes

The feasibility of a novel and simple layer-by-layer chemical deposition method for the preparation of nano-sized metal 8-hydroxyquinolate complexes has been investigated and reported. Uniform nanocrystalline films have been synthesized via dipping a substrate alternately in metal ion solution followed by ligand solution. The stoichiometry of the as-grown anhydrous Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complex crystals were confirmed from the metal analysis and molar stoichiometric ratio of metal ion to 8-hydroxyquinoline. This was characterized as 1:2 for the Co(II), Ni(II), Cu(II) and Zn(II)–quinolate complexes. The Fe(III)–quinolate thin film was found to exhibit a 1:3 ratio. Electron impact-mass spectra (EI-MS) of all the synthesized thin film metal quinolate complexes were recorded and the results refer to the existence of the molecular ion peak at the corresponding m/z values. Confirmation of such stoichiometric 1:2 and 1:3 ratios were also evident from the (EI-MS) study. The deposited thin films were also subjected to analysis by a scanning electron microscope (SEM) and a particle size ?50 nm was detected. FT-IR and UV–Vis spectroscopy were further used to confirm the structure of the metal 8-hydroxyquinolate complexes. Thermal gravimetric analysis (TGA) was also used to follow up the possible thermal decomposition steps and to calculate the thermodynamic parameters of the nano-sized metal complexes.     

Synthesis and characterization of 3-methyl-5-oxo-N,1-diphenyl-4,5-dihydro-1-H-pyrazole-4-carbothioamide and its metal complexes

The molecular parameters have been calculated to confirm the geometry of 3-methyl-5-oxo-N,1-diphenyl-4,5-dihydro-1-H-pyrazole-4-carbothioamide, HL. The compound is introduced as a new chelating agent for complexation with Cr(III), Fe(III), Co(II), Ni(II) and Cu(II) ions. The isolated chelates were characterized by partial elemental analyses, magnetic moments, spectra (IR, UV–vis, ESR; ¹H NMR) and thermal studies. The protonation constant of HL (5.04) and the stepwise stability constants of its Co(II), Cu(II), Cr(III) and Fe(III) complexes were calculated. The ligand coordinates as a monobasic bidentate through hydroxo and thiol groups in all complexes except Cr(III) which acts as a monobasic monodentate through the enolized carbonyl oxygen. Cr(III) and Fe(III) complexes measured normal magnetic moments; Cu(II) and Co(II) measured subnormal while Ni(II) complex is diamagnetic. The data confirm a high spin and low spin octahedral structures for the Fe(III) and Co(II) complexes. The ESR spectrum of the Cu(II) complex support the binuclear structure. The molecular parameters have also been calculated for the Cu(II) and Fe(III) complexes. The thermal decomposition stages of the complexes confirm the MS to be the residual part. Also, the thermodynamic and kinetic parameters were calculated for some decomposition steps.