Determination of Mo(VI) with 2-benzylideneiminobenzohydroxamic acid (2-BIBH) in urine by cathodic stripping voltammetry

Summary Controlled adsorptive accumulation of Mo(VI)-2-BIBH at the hanging mercury drop electrode (HMDE) provides the basis for the direct stripping measurement of Mo(VI) in nanomolar concentration. The cathodic stripping response is evaluated with respect to experimental parameters such as preconcentration time, preconcentration potential and others. A differential pulse cathodic stripping voltammetric method for the determination of Mo(VI) with 2-BIBH in urine is proposed. The detection limit is 10^–9 mol/l Mo(VI), standard deviation for 5×10^–8 mol/l is ±1.58×10^–9 mol/l.

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Bestimmung von MolybdÄn(VI) mit 2-BenzylideniminobenzohydroxamsÄure (2-BIBH) in Harn durch kathodische Stripping-Voltammetrie

     

Solvent extraction of molybdenum(VI) with 1-Phenyl-2-methyl-3-hydroxy-4-pyridone

Summary The extraction of molybdenum(VI) from aqueous hydrochloric or perchloric acid solution by 1-phenyl-2-methyl-3-hydroxy-4-pyridone (HX) dissolved in chloroform has been studied. Molybdenum(VI) is quantitatively extracted from aqueous solution in the range 0.001–1M hydrogen ion concentration. Outside this range, the extraction of molybdenum decreases and at 10M acid concentration or at pH>6 practically all the molybdenum remains in the aqueous phase. Molybdenum can be stripped with 10M HCl. The composition of the extracted molybdenum(VI) species was found to be MoO₂X₂. This complex, dissolved in chloroform, has a maximum absorbance at 317 nm and a molar absorptivity of 2.5×10⁴ 1 · mole^–1 · cm^–1. Owing to this property, molybdenum can be determined spectrophotometrically directly in the organic phase.

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Zusammenfassung Die Extraktion von Mo(VI) aus wäßriger Salzsäure oder Perchlorsäure mit 1-Phenyl-2-methyl-3-hydroxy-4-pyridon (HX) in chloroformischer Lösung wurde untersucht. Sie erfolgt quantitativ bei 0,001–1-molarer H-Ionenkonzentration. Außerhalb dieses Bereiches fällt die Extraktionsrate ab und aus 10-m Säure bzw. bei pH>6 bleibt praktisch alles Molybdän in der wäßrigen Phase. Mit 10-m Salzsäure kann man Mo abtrennen. Die Zusammensetzung der extrahierten Mo-Verbindung entspricht der Formel MoO₂X₂. Dieser in Chloroform gelöste Komplex hat ein Absorptionsmaximum bei 317 nm und eine molare Extinktion von 2,5 · 10⁴l · Mol^–1 cm^–1. Demzufolge läßt sich Molybdän unmittelbar in der organischen Phase spektrophotometrisch bestimmen.

     

Determination of subnanomolar concentrations of tungsten (VI) by catalytic adsorption polarography

A new differential pulse polarographic method for the determination of W(VI) using a catalytic adsorption wave is described. W(VI) is first chelated by 7-iodo-8-hydroxyquinoline-5-sulfonic acid at pH 0.5. The complex ion formed is strongly adsorbed on the surface of a dropping mercury electrode. At a potential of –0.95 V versus the Ag/AgCl (3M KCl) reference electrode the adsorbed complex is reduced by the polarographic current and oxidized very fast by hydrated hydrogen ions providing the oxidized form of the complex ion for repeated redox cycles. As the redox process taking place in the electric double layer, the diffusion of the complex does not limit the polarographic current. Therefore, high currents occur, and consequently, a very high sensitivity is obtained. The practical detection limit (PDL) is 3.7 ng W/kg solution corresponding to 2 × 10^–11 M. The standard deviation of single values is 1.2 ng/kg at the concentration of 91 ng/kg lying in the middle of the linear part of the calibration curve. Because Mo (VI) gives a very similar catalytic adsorption wave, serious mutual interferences occur in the analysis of mixtures of both species. An effective separation of Mo(VI) was worked out. Using 1% (w/v) solution of trioctylphosphinoxide in kerosene, Mo(VI) can almost completely be extracted from 1.8M HCl with a threefold extraction resulting in a separation factor of 40000.     

Estimation of Cr(VI) in water,tannery and plating wastes

Summary Estimation of Cr(VI) in Water, Tannery and Plating Wastes A zirconium tellurite membrane exhibits good selectivity for CrO₄ ^2– or CrO₇ ^2– ions at pH 3–6 and 8–11. Membrane electrode can be used to determine the activity of Cr(VI) ions in the concentration range 10^–1 to 7×10^–5 M at specified pH. The response time is 30 s and a large number of anions and cations do not interfere with the functioning of this assembly. It has been tried for the estimation of Cr(VI) in plating and tannery waste.     

Polarographische Studien an Uran(VI)-Verbindungen. I

Zusammenfassung Die polarographische Reduktion von Uran(VI) in schwefelsaurer Lösung an der Quecksilbertropfelektrode wurde untersucht und eine square-wave-polarographische Bestimmungsmethode ausgearbeitet, mit der noch 7·10^–7 Mol Uran/l in Gegenwart 20 anderer Metallionen gut reproduzierbar bestimmt werden können.

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Polarographic studies on uranium(vi) compounds, i

Summary The reduction of uranium(VI) in sulphuric acid solutions has been studied polarographically at the dropping mercury electrode and a square wave polarographic method for the determination up to 7·10^–7 M uranium in presence of 20 other metals is described.

     

Sorption and separation of some elements of nuclear importance using Chelex-100

Chelex-100, in the anionic form has been studied for its ability to perform selective separation and concentration of some metal ions of nuclear importance from mineral acid solutions. The sorption behavior of Zr(IV)–Nb(V), Mo(VI), Tc(VII), Te(IV) and U(VI) from solutions of hydrochloric and sulphuric acids on Chelex-100 has been studied under static and dynamic conditions. Mo(VI) and Tc(VII) have been concentrated on the resin from hydrochloric or sulphuric acid solutions at low acidities probably, as the anions MoO ₄ ^2– and TcO ₄ ^– , respectively. Te(IV) has been isolated from hydrochloric acid solutions of normalities 6 in the form of the anionic chloro complex TeCl ₆ ^2– . Optimum conditions for elution and separation of Mo(VI), Tc(VII), Te(IV) and U(VI) were recommended.     

LIX 84 as an extractant for throium(IV), uranium(VI) and molybdenum(VI)

The extraction order of Th(IV), U(VI) and Mo(VI) based on pH_0.5 values is Mo(VI)>U(VI)>Th(IV). Quantitative extraction has been observed for U(VI) by mixture of 10% (v/v) LIX 84 and 0.1M dibenzoylmethane at pH 4.2 and by mixture of 10% LIX 84 and 0.05M HTTA in the pH range 5.5–7.3 and for Mo(VI) by 10% LIX 84 from chloride media at pH 1.5. The order of extraction of Mo(VI) from 1N acid solutions is HCl>H₂SO₄>HNO₃>HClO₄ and extraction decreases very rapidly with increase in the concentration of HCl as compared to that from H₂SO₄, HNO₃ and HClO₄ acid solutions. The diluents C₆H₆, CCl₄ and CHCl₂ are found to be superior ton-butyl alcohol and isoamyl alcohol for extraction of Mo(VI). Influence of concentration of different anions on the extraction of U(VI) and Mo(VI) has been studied. Very little extraction has been observed in case of Th(IV) by LIX 84 or its mixtures with other chelating extractants or neutral donors.     

Polymethylenebis(octylarsinic acids), [C8H17As(O)OH]2 (CH2)n,as reagents for the liquid-liquid extraction of cerium(III) and Europium(III)

Summary Cerium(III) and europium(III) are extracted at 50° C by [C₈H₁₇ As(O)OH]₂(CH₂) _n (n=6, 8, 12) inn-octanol from aqueous solutions containing NaCl and acetic acid/sodium acetate in the pH range 6.7–8.0. The extraction coefficient, , reached a maximum of: 10.0, 13.2 forn=6; 10.7, 20.0 forn=8; 4.68, 6.03 forn=12; at an aqueous equilibrium pH of: 7.65, 7.80 forn=6; 7.89, 7.95 forn=8; 7.81, 7.82 forn=12; corresponding to the extraction efficiency of: 91%, 93% forn=6; 92%, 95% forn=8; 80%, 83% forn=12; for cerium and europium, respectively.The log was found to be second power dependent for cerium and one and one-half power dependent for europium on the negative log of the aqueous equilibrium [H⁺] forn=6, 8, 12. The extractions were done at 50°C using organic reagent solutions (1.09×10^–3 M forn=12, 1.08 × 10^–3 M forn=8, 1.32×10^–3 M forn=6) and aqueous solutions of 1.0×10^–5 M for CeCl₃ and EuCl₃, having their Cl^– ionic strengths adjusted to 0.100 molar with NaCl. It was found that the slopes increase in the pH dependence studies in the seriesn=6, 8, and 12 for both cerium and europium metal ions. The reagent dependence studies were done at 50°C and pH: 7.00, 6.80 forn=6; 7.30, 7.20 forn=8; 7.45, 7.35 forn=12; for cerium and europium, respectively. The log was found to be first power dependent on the log of the uncomplexed reagent concentration at equilibrium. It is assumed that the complexes are hexacoordinated.

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Polymethylenebis-Oktylarsinsäuren als Reagenzien für die Flüssig-flüssig-Extraktion von Cer(III) und Europium(III)

Zusammenfassung Cer(III) und Europium(III) werden aus wäßrigen, Kochsalz und Essigsäure/Acetat enthaltenden Lösungen bei 50°C mit C₈H₁₇As(O)OH₂(CH₂)_n (_n=6, 8, 12) im pH-Gebiet 6,7–8,0 extrahiert. Der Extraktionskoeffizient erreicht ein Maximum von: 10,0, 13,2 für_n=6; 10,7, 20,0 fürn=8; 4,68, 6,03 fürn=12; bei einem wäßrigen Gleichgewicht-pH von: 7,65, 7,80 fürn=6; 7,89, 7,95 fürn=8; 7,81, 7,82 fürn=12, entsprechend dem Aus maß der Extraktion von: 91%, 93% fürn=6; 92%, 95% fürn=8; 80%, 83% fürn=12; für Ce bzw. Eu.Für Cer ist der log in zweiter Potenz, für Europium in erster und 1/2 Potenz abhängig vom negativen log des wäßrigen [H⁺]-Gleichgewichtes fürn=6, 8, 12. Die Extraktionen wurden bei 50°C mit organischen Reagens-lösungen (1,09×10^–3 M fürn=12, 1,08×10^–3 M fürn=8, 1,32×10^–3 M fürn=6) und mit wäßrigen Lösungen von 1,0×10^–5 M für CeCl₃ und EuCl₃ durchgeführt, deren lonenstärke für Cl^– mit NaCl auf 0,100M eingestellt wurde. Bei der Untersuchung der pH-Abhängigkeit bei den Reihenn=6, 8 und 12 ergab sich ein Anstieg sowohl für Ce wie für Eu. Die Reagens-Abhängigkeit wurde bei 50°C und bei pH 7,00, 6,80 fürn=6; 7,30, 7,20 fürn=8; 7,45, 7,35 fürn=12 für Cer bzw. Europium geprüft. Der log war einfach abhängig vom log der Konzentration des unkomplexierten Reagens beim Gleichgewicht. Es wird angenommen, daß die Komplexe hexakoordiniert sind.

     

Metal chelates in adsorption polarography I: Mo(VI) and derivatives of oxine

The formation of complexes between Mo(VI) and 8-hydroxy-quinoline (oxine) and four oxine derivatives were investigated by multiwavelength molecular absorption spectrometry, potentiometry, and polarography. The following pK_OH- and pK_NH- values of the ligands and logK ₂₁₁-values of the complexes MoO₂(OH)₂L ^x– (x=1 or 2) were obtained at 25° C and an ionic strength of 1M(NaClO₄): 5,7-dinitro8-hydroxyquinoline 4.59, <0, 14.50; 7-nitro-8-hydroxyquinoline-5-sulfonic acid 5.34, 0.41, 15.70; 7-iodo-8-hydroxyquinoline-5-sulfonic acid 6.98, 2.62, 17.65; 8-hydroxyquinoline-5-sulfonic acid 8.33, 4.13, 18.71; and 8-hydroxyquinoline 9.62, 5.28, 19.69. A good linearity was found between logK ₂₁₁ and the sum of the pK-values of the OH- and NH⁺-groups. The dependence of the peak current of Mo(VI)-determinations by adsorption polarography of the 7-nitro-8-hydroxyquinoline-5-sulfonate complex of Mo(VI) MoO(OH)₃L^– can quantitatively be described at pH 0.8–2 using the corresponding pK-values and the log K₃₁₁ of 18.54±0.03, determined by polarography.     

Polarographic determination of uranium(VI) after salting-out extraction as 8-quinolinolate in acetonitrile

Summary Uranium(VI) can be extracted as its 8-quinolinolate into acetonitrile by means of salting-out with ammonium and sodium acetates, respectively; the metal oxinates extracted give a well-defined dc polarogram with E _1/2=–0.80V and a sharp square wave (sw) polarogram with E _p=–0.96V in the extract. The dc wave height and the sw peak current are directly proportional to the uranium(VI) concentration in the range of 6.0×10^–6 to 4.0×10^–4M at pH 6.7–10.0 and 8.0×10^–7 to 2.8×10^–5M at pH 10.5–11.0, respectively. A number of ions do not interfere in the presence of EDTA.

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Polarographische Bestimmung von Uran(VI) nach Aussalz-Extraktion als 8-Hydroxychinolat mit Acetonitril

Zusammenfassung Uran(VI) kann durch Aussalzen mit Ammonium- bzw. Natriumacetat als Oxinat mit Acetonitril extrahiert werden. Das extrahierte Oxinat ergibt ein gut ausgebildetes Gleichstrompolarogramm mit E _1/2=–0,80 V bzw. ein scharfes square-wave-Polarogramm mit E _p=–0,96 V. Die Gleichstrom-Stufenhöhe bzw. der square-wave-Peakstrom sind der U(VI)-Konzentration im Bereich 6,0·10^–6-4,0· 10^–4M (pH 6,7–10,0) bzw. 8,0·10^–7-2,8·10 ^–5M (pH 10,5–11,0) direkt proportional. Durch Zusatz von EDTA kann eine Reihe von Störungen ausgeschaltet werden.

     

Die kinetische polarographische Stufe des Urans in Gegenwart von Chlorat-Ionen

An increase of the 2nd polarographic uranium(VI) wave has been observed in the presence of chlorate ions in HClO₄–NaClO₄, or HClO₄–NaClO₄–NaCl supporting electrolyte, resp. The polarographic measurements at different temperatures and at various perchloric acid concentrations show that this increase is due to a kinetic U(III)-U(IV) current. The activation parameters of the U(III)-U(IV) oxidation reaction with ClO₃ ^– have been calculated usingKautecky's method.The approximately 5fold increase of the 2nd polarographic wave allows the determination of small amounts of uranium (10^–5–10^–6 mole/l).

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Mit 2 Abbildungen     

Thermodynamic Model for the Solubility of TcO2· xH2O(am) in the Aqueous Tc(IV) – Na+ – Cl− – H+ – OH− – H2O System

Solubility studies of TcO₂· xH₂O(am) have been conducted as a function of H⁺ concentration from 1 × 10^{– 5} to 6 M HCl and as a function of chloride concentration from 1 × 10^{– 3} to 5 M NaCl. These experiments were conducted under carefully controlled reducing conditions such that the preponderance of Tc present in solution is in the reduced oxidation state and was determined to be Tc(IV) by XANES analysis. The aqueous species and solid phases were characterized using a combination of techniques including thermodynamic analyses of solubility data, XRD, and XANES, EXAFS, and UV-vis spectroscopies. Chloride was found to significantly affect Tc(IV) concentrations through (1) the formation of Tc(IV) chloro complexes [i.e., TcCl₄(aq) and TcCl₆ ^{2 –}] and a stable compound [data suggests this compound to be TcCl₄(am)] in highly acidic and relatively concentrated chloride solutions, and (2) its interactions with the positively charged hydrolyzed Tc(IV) species in solutions of relatively low acidity and high chloride concentrations. A thermodynamic model was developed that included hitherto unavailable chemical potentials of the Tc(IV)–chloro species and Pitzer ion-interaction parameters for Tc(IV) hydrolyzed species with bulk electrolyte ions used in this study. The thermodynamic model presented in this paper is consistent with the extensive data reported in this study and with the reliable literature data and is applicable to a wide range of H⁺ and Cl^– concentrations and ionic strengths.     

Enhanced sensitivity for the differential pulse polarographic determination of Mo(VI) based on adsorption catalytic current

A differential pulse polarographic (DPP) method based on the adsorption catalytic current in a medium containing chlorate and 8-hydroxyquinoline (oxine) is suggested for the determination of molybdenum(VI). Experimental conditions such as pH and the composition of supporting electrolyte have been optimized to get a linear calibration graph at trace levels of Mo(VI). The sensitivity for molybdenum can be considerably enhanced by this method. The influence of possible interferences on the catalytic current has been investigated. The sensitivity of the method is compared with those obtained for other DPP methods for molybdenum. A detection limit of 1.0 × 10^–8 mol/L has been found.     

Thermodynamics and Kinetics of Reaction of (Oxo)(hydroxo)molybdenumtetraphenylporphyrin with Pyridine

The reaction of meso-tetraphenylporphyrin with Mo(VI) oxide in boiling phenol resulted in a stable complex O=Mo(OH)TPP. Thermodynamics and kinetics of the reaction between (oxo)(hydroxo)molybdenumtetraphenyporphyrin with pyridine in toluene were studied by spectrophotometric method. This reaction was found to occur in three equilibrium elementary stages: replacement of OH^– by Py (K ₁=9.1 × 10³ l/mol, k ₁=5.25 s^–1 mol^–1 l), the formation of dication (dipyridine)(hydroxo)molybdenumtetraphenylporphyrin as a result of cleavage of a double bond Mo=O (K ²=39.3 l/mol, k ₂=1.83 × 10^–2 s^-1 mol^–1 l), and the formation of cationic complex[Mo(Py)₃TPP]³⁺ · 3OH^– (K ₃=1.0 l/mol, k ₃=1.19 × 10^–3 s^–1 mol^–1 l).__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 380–386.Original Russian Text Copyright © 2005 by Tipugina, Lomova, Motorina.     

Complex equilibria of molybdenum(VI) with 2,3-dihydroxynaphthalene

Equilibria of Mo(VI) in acid aqueous solutions with excess of 2,3-dihydroxynaphthalene (DHN)c _DHN /c _Mo = 2.3–107 (I = 0.6 mol 1^–1 (NaClO₄), 0.6% v/v ethanol) were studied spectrophotometrically. Formation constants of MoO₂R ₂ ^2– (logK ₀₁₂ = 5.89±0.01) and presumed MoO₂(OH)(OH₂)R^– (logK ₁₁₁ = 7.79±0.01) chelates were evaluated using SQUAD-G program.     

Liquid-liquid extraction of molybdenum(VI) and uranium(VI) by LIX 622

The order of extraction of Mo(VI) from 1M acid solutions by 5% (v/v) LIX 622 (HL) in benzene is HCl>HNO₃>HClO₄>H₂SO₄, and extraction decreases with increasing concentration of HCl and H₂SO₄, and increases slightly with increasing concentration of HNO₃ and HClO₄. The extracted species is shown to be MoO₂L₂ as established by IR data of organic extracts and the extracted species in the solid form. Extraction is almost quantitative at and above 10% LIX 622, and is found to be independent of [Mo(VI)] in the range of 10^–4 to 10^–3 M. The diluents CCl₄, CHCl₃ and C₆H₆ are found to be superior to solvents of high dielectric constant for extraction of Mo(VI). Extraction of uranium(VI) by 10% (v/v) LIX 622 in benzene was found to increase with increasing equilibrium pH (3.0 to 6.0), and becomes quantitative at pH 5.9. Tributyl phosphate acts as a modifier up to 2% (v/v). Thorium(IV) is almost not extracted by LIX 622 or its mixture. Separation of Mo(VI) and U(VI) is feasible.     

Extraction and separation of uranium(VI) and protactinium(V) with 1-(4-tolyl)-2-methyl-3-hydroxy-4-pyridone

Summary The extraction of uranium(VI) from aqueous hydrochloric or nitric acid, and the extraction of protactinium from hydrochloric acid by 1-(4-tolyl)-2-methyl-3-hydroxy-4-pyridone (HY) dissolved in chloroform has been studied. At pH >4, uranium (VI) is quantitatively extracted while at pH < 1 practically all the uranium remains in the aqueous phase. At hydrochloric acid concentrations lower than 1M, protactinium(V) is quantitatively extracted while at hydrochloric acid concentration higher than 5M practically all the protactinium remains in the aqueous phase. This difference in extraction of uranium and protactinium was utilized for their separation. From 0.5M hydrochloric acid, protactinium is quantitatively extracted, and separated from uranium.The composition of the extracted uranium(VI) and protactinium (V) complexes was studied. A uranium complex with the formula UO₂Y₂ · HY was isolated from the chloroform solution. The solution of this complex in chloroform has a maximum absorbance at 319 nm and the molar absorptivity is 3.1×10⁴ l · mole^–1 · cm^–1. Owing to this property uranium can be determined spectro-photometrically directly in the organic phase.

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Zusammenfassung Die Extraktion von Uran(VI) aus wäßriger Salzsäure oder Salpetersäure sowie die Extraktion von Protaktinium aus Salzsäure mit 1-(4-Tolyl)-2-methyl-3-hydroxy-4-pyridon (HY) in chloroformischer Lösung wurde untersucht. Bei pH > 4 wird U(VI) quantitativ extrahiert, während bei pH < 1 praktisch alles Uran in der wäßrigen Phase bleibt. Bei Salzsäurekonzen-trationen unter 1-m wird Protaktinium (V) quantitativ extrahiert, während bei Salzsäurekonzentrationen über 5-m praktisch alles Pa in der wäßrigen Phase bleibt. Dieser Unterschied bei der Extraktion der beiden Elemente wurde für deren Trennung benützt. Pa wird aus 0,5-m Salzsäure quantitativ extrahiert und so von Uran getrennt.Die Zusammensetzung der extrahierten U (VI)- und Pa (V)-Komplexe wurde untersucht. Ein Urankomplex der Formel UO₂ · Y₂ · HY wurde aus der Chloroformlösung isoliert. Die Lösung dieses Komplexes in Chloroform hat ein Absorptionsmaximum bei 319 nm und eine molare Extinktion von 3,1 · 10⁴ l · mol^–1 · cm^–1. Auf Grund dieser Eigenschaft kann Uran spektrophotometrisch direkt in der organischen Phase bestimmt werden.

     

Removal, preconcentration and determination of Mo(VI) from water and wastewater samples using maghemite nanoparticles

Removal and recovery of Mo(VI) from aqueous solutions were investigated using maghemite (γ-Fe₂O₃) nanoparticles. Combination of nanoparticle adsorption and magnetic separation was used to the removal and recovery of Mo(VI) from water and wastewater solutions. The nanoscale maghemite with mean diameter of 50 nm was synthesized by reduction coprecipitation method followed by aeration oxidation. Various factors influencing the adsorption of Mo(VI), e.g. pH, temperature, initial concentration, and coexisting common ions were studied. Adsorption reached equilibrium within <10 min and was independent of initial concentration of Mo(VI). Studies were performed at different pH values to find out the pH at which maximum adsorption occurred. The maximum adsorption occurred at pHs between 4.0 and 6.0. The Langmuir adsorption capacity (q_max) was found to be 33.4 mg Mo(VI)/g of the adsorbent. The results showed that nanoparticle (γ-Fe₂O₃) is suitable for the removal of Mo(VI), as molybdate, from water and wastewater samples. The adsorbed Mo(VI) was then desorbed and determined spectrophotometrically using bromopyrogallol red as a complexation reagent. This allows the determination of Mo(VI) in the range 1.0–86.0 ng mL⁻¹.     

Electron-transfer kinetics and mechanism of the reduction of octacyanometallates(IV) (M = Mo,W) by hydroxide ion in aqueous solution

Summary The kinetics of the reduction of octacyanometallates(IV) in alkaline aqueous medium have been studied spectrophotometrically. The experimental results are in agreement with following rate law:-d[M(CN) _inf8 ^sup3– ]/dt = k _obs[M(CN) _inf8 ^sup3– ]²[OH^–][Na⁺] where k _obs = 4.1 × 10^–2M^–3s^–1 (Mo) and 4.0 × 10^–4 M^–3 s^–1 (W). The rate data were used to calculate the thermodynamic activation parameters H and S . A mechanism of the reaction is discussed.On leave from Faculty of Chemistry, Forest Engineering Institute, Archangelsk, Russia.     

Differential pulse polarographic determination of some organotin(IV) compounds in dimethyl sulfoxide

The differential pulse polarographic behavior of two series of organotin(IV) compounds having the general formula R_xSnCl_{4 − x} (R = Me, Ph; x = 1, 2, 3, 4) has been investigated in DMSO. The peaks obtained are recommended for the trace determination of these compounds. Linear calibration curves are obtained over the concentration range 10⁻⁴ –10⁻⁶ M.