Chelometric Titrations Using Azoarsonic Acid Indicator

Fritz, James S.; Oliver, Richard T.; Pietrzyk, Donald J.

doi:10.1021/ac60138a032

Cited by 129 publications

(54 citation statements)

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“…[12] The amounts of rare earths() were determined by complexometric titrations with EDTA. [20,21,22] Solid KAsF 6 (Ozark Mahoning), solid LnF 3 (all from Alfa; the experiment with TmF 3 has not been conducted), standard solutions of Ln III [C ϭ 1000…”

Section: Methodsmentioning

confidence: 99%

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

2004

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Results of elemental chemical analyses of the coordination compounds of the type LnFn(AsF6)3‐n (Ln = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) indicated unexpectedly low stability of the generally highly hydrolytically stable [AsF6]− ion. Experiments conducted on model compounds of the type NdFn(AsF6)3‐n have shown that hydrolysis proceeded instantaneously during the reaction of the solid compound with water. The ligand substitution catalysis of the compounds is explained in terms of the distortion of the [AsF6]− octahedra earlier shown by vibrational spectroscopy. The study contrasts formally related reactions on the solid−solvent interface as opposed to those in homogeneous solution. A new look at some long studied and well‐known inorganic species is offered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

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Section: Methodsmentioning

confidence: 99%

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

2004

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“…All chemicals used were purchased from Acros or Aldrich and were used without further purification. A color test reaction for free lanthanides was performed with Arsenazo III as the indicator [33]. pH Measurements were made at r.t. with a Corning 125 pH meter and a calibrated micro-combination probe purchased from Aldrich Chemical Co.…”

Section: Experimental Partmentioning

confidence: 99%

Structure and Dynamics of Lanthanide Complexes of Triethylenetetramine‐N,N,N′,N″,N′′′,N′′′‐hexaacetic Acid (H₆ttha) and of Diamides H₄ttha(NHR) Derived from H₆ttha as Studied by NMR, NMRD, and EPR

Zitha-Bovens

Müller

Laurent

et al. 2005

Helvetica Chimica Acta

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“…10 À3 M CeCl 3 Á 6H 2 O, Th(NO 3 ) 4 , and UO 2 (CH 3 COO) 2 Á 2H 2 O solutions were prepared and standardized with EDTA using the appropriate indicator [27,28]. Both CeCl 3 Á 6H 2 O and Th(NO 3 ) 4 were dissolved in water, whereas Schiff bases and UO 2 (CH 3 COO) 2 Á 2H 2 O were dissolved in ethanol due to their insolubility in H 2 O.…”

Section: Methodsmentioning

confidence: 99%

Chelation Behaviour of Ce(III), Th(IV), and UO2(VI) with 5,7-Dihydroxy-6-formyl-2-methylbenzopyran-4-one Schiff Bases

Issa¹,

Sherif²,

Abbas³

1998

Monatshefte fuer Chemie

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The stability constants of the stepwise chelate formation between Ce 3 , Th 4 , and UO 2 2 ions and some Schiff bases derived from 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one were determined conductometrically as well as potentiometrically applying the Irving and Rossotti techniques. The results indicate the formation of 1:1 and 1:2 (M:L) chelates. The stability constants increase with decreasing ionic strength, decreasing temperature, and decreasing percentage of ethanol. In different organic solvents (70% v/v solvent-water media), the stability constant values follow the order MeOH < EtOH < 1-propanol < 2-propanol < acetone < DMSO depending on both the dielectric constant and the hydrogen bonding structure of the medium. The thermodynamic parameters (ÁG, ÁH, and ÁS) were calculated; they indicate that the chelate formation is an exothermic process and that the degree of disorder of the solution increases upon chelation.Das Chelierungsverhalten von Ce 3 , Th 4 und UO 2 2 mit Schiffschen Basen vom Typ 5,7-Dihydroxy-6-formyl-2-methylbenzopyran-4-on Zusammenfassung. Die Stabilita Ètskonstanten fu Èr die stufenweise Chelatbildung von Ce 3 -, Th 4 -und UO 2 2 -Ionen mit von 5,7-Dihydroxy-6-formyl-2-methylbenzopyran-4-onen abgeleiteten Schiffschen Basen wurden konduktometrisch und potentiometrisch mit Hilfe der Irving-Rossotti-Technik bestimmt. Die Ergebnisse zeigen die Bildung von 1:1-und 1:2-Chelaten (M:L) an. Die Stabilita Èkonstanten steigen mit steigender Ionensta Èrke, abnehmender Temperatur und abnehmendem Anteil von Ethanol. In verschiedenen organischen Lo Èsungsmitteln (70% v/v Lo Èsungsmittel-WasserGemische) folgen die Stabilita Ètskonstanten der Reihe MeOH < EtOH < 1-Propanol < 2-Propanol < Aceton < DMSO, ha Èngen also sowohl von der Dielektrizita Ètskonstante als auch von der Wasserstoffbru Èckenbindungsstruktur des Mediums ab. Die thermodynamischen Parameter (ÁG, ÁH und ÁS) wurden bestimmt; sie weisen darauf hin, daû die Bildung solcher Chelate exotherm verla Èuft und daû und der Unordnungsgrad der Lo Èsung bei der Chelierung steigt.

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Chelometric Titrations Using Azoarsonic Acid Indicator

Cited by 129 publications

References 5 publications

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

Structure and Dynamics of Lanthanide Complexes of Triethylenetetramine‐N,N,N′,N″,N′′′,N′′′‐hexaacetic Acid (H₆ttha) and of Diamides H₄ttha(NHR) Derived from H₆ttha as Studied by NMR, NMRD, and EPR

Chelation Behaviour of Ce(III), Th(IV), and UO2(VI) with 5,7-Dihydroxy-6-formyl-2-methylbenzopyran-4-one Schiff Bases

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Chelometric Titrations Using Azoarsonic Acid Indicator

Cited by 129 publications

References 5 publications

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF6]− Ion

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF6]− Ion

Structure and Dynamics of Lanthanide Complexes of Triethylenetetramine‐N,N,N′,N″,N′′′,N′′′‐hexaacetic Acid (H6ttha) and of Diamides H4ttha(NHR) Derived from H6ttha as Studied by NMR, NMRD, and EPR

Chelation Behaviour of Ce(III), Th(IV), and UO2(VI) with 5,7-Dihydroxy-6-formyl-2-methylbenzopyran-4-one Schiff Bases

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The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

The Solid‐State Lanthanoid‐Assisted Hydrolysis of the Solvolytically “Inert” [AsF₆]⁻ Ion

Structure and Dynamics of Lanthanide Complexes of Triethylenetetramine‐N,N,N′,N″,N′′′,N′′′‐hexaacetic Acid (H₆ttha) and of Diamides H₄ttha(NHR) Derived from H₆ttha as Studied by NMR, NMRD, and EPR