Komplexone XXV. Die polarographische Untersuchung von Austauschgleichgewichten. Neue Daten der Bildungskonstanten von Metallkomplexen der Äthylendiamin‐tetraessigsäure und der 1,2‐Diaminocyclohexan‐tetraessigsäure

Schwarzenbach, G.; Gut, R.; Anderegg, G.

doi:10.1002/hlca.19540370402

Cited by 391 publications

(31 citation statements)

References 13 publications

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“…In the case of Cd(II)-EDTA titration, the ammonia by using the above-determined KCdD value and the numerical values13,16) given in Table 2 can be considered to have a magnitude which can explain well the facts given by Schwarzenbach et al 13) From the facts obtained and the theoretical discussion given above, it can be safely concluded that reasonable KPbD and KcdD values have been determined.…”

Section: The Above Relations Indicate That When Mdis Formed Only Thesupporting

confidence: 62%

Spectrophotometric Study of Metal Chelates of Eriochrom Black T (BT). II. Solution Equilibria between BT and Lead(II)-Nitrilotriacetate (NTA) or Cadmium(II)-N′-(Hydroxyethyl)-ethylenediamine-N, N, N′-triacetate (EDTA-OH)

Kodama

Sasaki

1968

Bulletin of the Chemical Society of Japan

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The solution equilibria between BT and lead(II)-NTA or cadmium(II)-EDTA-OH chelates were studied spectrophotometrically, and the composition and the stability constants of the BT chelates of these metal ions were determined. In the presence of an excess amount of NTA or EDTA-OH, lead(II) and cadmium(II) ions join with BT to form a chelate with a 1-to-1 composition. The magnitude of the stability constants (1013.19 and 1012.74 respectively, μ=0.30) can explain satisfactorily the well-known experimental fact that BT can be used as a metallochromic indicator in Pb(II)- and Cd(II)-EDTA titrations.

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Section: The Above Relations Indicate That When Mdis Formed Only Thesupporting

confidence: 62%

Spectrophotometric Study of Metal Chelates of Eriochrom Black T (BT). II. Solution Equilibria between BT and Lead(II)-Nitrilotriacetate (NTA) or Cadmium(II)-N′-(Hydroxyethyl)-ethylenediamine-N, N, N′-triacetate (EDTA-OH)

Kodama

Sasaki

1968

Bulletin of the Chemical Society of Japan

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“…2 clearly shows that BT forms only normal chelate CoD-with cobalt(II) under the experimental conditions. With the aid of relation (2), the stability constant for CoD-was calculated to be 100.0 by using the log{ Since the kinetic measurements were carried out in solutions containing EDTA and cobalt(II)-EDTA chelate in an excess over BT, the overall exchange reaction of BT and cobalt(II)-EDTA system (1) can be simplified to, (5) whose reaction rate is given by (6) where k's mean the apparent rate constants. Integrating Eq.…”

Section: Resultsmentioning

confidence: 99%

Spectrophotometric Studies of the Solution Equilibria and the Kinetics of the Substitution Reaction between Eriochrom Black T and Cobalt(II)-Ethylenediaminetetraacetate Chelate

Kodama¹

1967

Bulletin of the Chemical Society of Japan

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The solution equilibria and the kinetics of the substitution reaction between Eriochrom Black T (BT) and cobalt(II)-EDTA chelate were studied spectrophotometrically.At the pH range from 8.50 to 9.50, BT was found to form only 1 to I normal chelate CoD-with cobalt(II), the stability constant of which is 10 20.0 Kinetically, the substitution reaction was found to proceed through the following two simultaneous reaction paths, i)ii) and k1+ and k2+ were determined to be 0.23 l mol-1 sec-1 andIn the previous paper,1) the solution equilibria between Eriochrom Black T (BT) and zinc(II)-NTA or copper(II)-CyDTA chelate were studied spectrophotometrically, and the stability constants and the compositions of 1 to 1 chelates of BT with these metal ions were determined. The rate of substitution reaction between BT and zinc(II)-NTA or copper (II) -CyDTA chelates was very large and the reaction mixtures reached the equilibrium within 30 sec.In the case of the substitution reaction of BT and cobalt(II)-EDTA chelate, however, the reaction proceeds at a considerable rate. In the present paper, spectrophotometeric studies of the solution equilibria and of the kinetics of the substitution reaction between BT and cobalt(II)-EDTA chelate are presented. ExperimentalThe standard solution of cobalt(II) was prepared by the following procedure. Hot ammoniacal metal solution was treated with a 1 percent solution of dimethylglyoxime in ethanol and filtered carefully using a frittedglass funnel. To the filterate, an excessive amount of sodium hydroxide was added and the solution was heated nearly to boiling point to precipitate cobalt(II) ions as hydroxide. The resulting precipitate was filtered off, washed thoroughly with redistilled water, and dissolved in diluted perchloric acid solution. The concentration of cobalt(II) was then determined by titration with a standard EDTA solution.2) The solution of disodium salt of ethylenediaminetetraacetate (EDTA) was standardized against pure metallic zinc.As was described in the previous paper,1) BT was purified by employing the procedure described by Diehl and Lindstrom 3) and the purity was checked spectrophotometrically.

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“…However, the pH titration was carried out successfully when the transition metals and calcium were chosen as the first and the second metal ions respectively, and the stability constants for the transition metalcalcium TAPHA chelates (KMCaL) were obtained from Eq. (14). The various equilibrium constants thus obtained are summarized in Tables 3-8.…”

Section: Table 2 Definitions Of Equilibrium Constantsmentioning

confidence: 99%

Synthesis of Chelating Agents. VI. Chelating Behavior of 1,2,3-Triaminopropanehexaacetic Acid with Divalent Metal Ions

MoriguchiYoshiki¹,

MiyazakiMitsumasa²,

UenoKeihei³

1968

Bulletin of the Chemical Society of Japan

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Komplexone XXV. Die polarographische Untersuchung von Austauschgleichgewichten. Neue Daten der Bildungskonstanten von Metallkomplexen der Äthylendiamin‐tetraessigsäure und der 1,2‐Diaminocyclohexan‐tetraessigsäure

Cited by 391 publications

References 13 publications

Spectrophotometric Study of Metal Chelates of Eriochrom Black T (BT). II. Solution Equilibria between BT and Lead(II)-Nitrilotriacetate (NTA) or Cadmium(II)-N′-(Hydroxyethyl)-ethylenediamine-N, N, N′-triacetate (EDTA-OH)

Spectrophotometric Study of Metal Chelates of Eriochrom Black T (BT). II. Solution Equilibria between BT and Lead(II)-Nitrilotriacetate (NTA) or Cadmium(II)-N′-(Hydroxyethyl)-ethylenediamine-N, N, N′-triacetate (EDTA-OH)

Spectrophotometric Studies of the Solution Equilibria and the Kinetics of the Substitution Reaction between Eriochrom Black T and Cobalt(II)-Ethylenediaminetetraacetate Chelate

Synthesis of Chelating Agents. VI. Chelating Behavior of 1,2,3-Triaminopropanehexaacetic Acid with Divalent Metal Ions

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