Micellar Effects on the Reaction S2O82−+ Fe(CN)4(bpy)2−

Rodrı́guez, Amalia; Graciani, Marı́a del Mar; Moyá, Marı́a Luisa

doi:10.1006/jcis.1997.4932

Cited by 10 publications

(16 citation statements)

References 20 publications

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“…Figure 1 shows the plot of against does not exhibit a meaningful intercept. This shows that no dissociation of the reagent occurs during the reaction, as ex-3Ϫ Fe(CN) (4-CNpy) 5 pected, taking into account the large excess of 4-cyanopyridine ligand present in the reaction media. Table I shows the second order rate constants in various concentrated electrolyte aqueous solutions.…”

Section: Resultsmentioning

confidence: 87%

“…There is no information about ion-pairing constants for the ions , but from the values of 3Ϫ Fe(CN) (4-CNpy) 5 the ion-pairing equilibrium constants given for the related species [14], one would expect ion-3Ϫ Fe(CN) , 6 pairing equilibria to also be important for the molecules. The different ion pairs 3Ϫ Fe(CN) (4-CNpy) 5 would undergo reaction at rates specific to the cations.…”

Section: Discussionmentioning

confidence: 99%

“…Fe(CN) (4-CNpy) 5 Therefore one can be sure that the disappearance of the species is due only to the re-3Ϫ Fe(CN) (4-CNpy) 5 dox reaction under study. All kinetics were followed during three half-lives and each experiment was repeated at least twice.…”

Section: ϫmentioning

confidence: 97%

“…These reactions occur between two anionic species and therefore seem interesting in the investigation of kinetic micellar effects in cationic micellar solutions. The solubility of peroxodisulfate ions in cationic surfactant solutions is low [5]. Nonetheless, the Fe(CN) 5 L 3Ϫ complexes show metal-to-ligand charge transfer bands (MLCT) in the visible region of the spectrum, characterized by high molar extinction coefficients [6].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Study of the reaction Fe(CN)5(4-CNpy)3? + S2O82? in aqueous salt and micellar solutions

Fernández

Graciani

Rodrı́guez

et al. 1999

Int. J. Chem. Kinet.

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The reaction (4-CNpy ϭ 4-cyanopyridine) was studied 3Ϫ 2Ϫ Fe(CN) (4-CNpy) ϩ S O 5 2 8in aqueous salt solutions in the presence of several electrolytes as well as in anionic, cationic, and nonionic surfactant solutions. In aqueous salt solutions the noncoulombic interactions seem to be important in determining the positive salt effects observed. The salting effects are influencing the activity coefficients of any participant in the reaction, including those ion pairs which can be formed between the anionic reagents and the cations which come from the added salts. The changes in surfactant concentration in anionic and nonionic surfactant solutions do not affect the reaction rate, which is similar to that in pure water at the same ionic strength. In cationic micellar solutions an increase in the rate constant compared to that in pure water is found; the reaction rate decreasing when the surfactant concentration increases. The kinetic trends can be explained assuming that the reagents are totally bound to the micelles and, therefore, an increase in the surfactant concentration results in a decrease in the reagent concentrations at the micellar phase and thus in a decrease in the observed rate constant.

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Section: Resultsmentioning

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: ϫmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study of the reaction Fe(CN)5(4-CNpy)3? + S2O82? in aqueous salt and micellar solutions

Fernández

Graciani

Rodrı́guez

et al. 1999

Int. J. Chem. Kinet.

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“…Many results have been published in the literature showing the accelerating or inhibitory effects of anionic, cationic and non-ionic surfactants [24][25][26][27][28][29].…”

Section: Resultsmentioning

confidence: 99%

Surfactant‐Mediated Catalytic Determination of Fe(II) in Herbal and Pharmaceutical Products

Khan

Siddiqui

Uddin

2007

J Surfact & Detergents

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In the present work, the catalyzed oxidation of neutral red (NR) by bromate was used to work out a kinetic-based analytical method as an alternative technique for the determination of Fe(II) in real and synthetic samples. A use of a surfactant, N-dodecylpyridinium chloride enhanced the sensitivity of the reaction by becoming involved in the reaction mechanism and providing a more suitable reaction environment. The iron-catalyzed oxidation of NR with potassium bromate was studied kinetically by using a fixed time method. The reaction was followed by measuring the decrease in absorbance at 535 nm. The use of a surfactant in the analytical run showed a five times increase in the sensitivity of the method. It served as a ready reservoir of NR by increasing its solubilization. The salt effect, pH, and reagent concentration were also investigated to achieve a more selective and sensitive analytical procedure. Under optimized conditions (4.2 · 10 -5 mol L -1 NR, 1.4 · 10 -3 mol L -1 KBrO 3 , 1.5 · 10 -2 mol L -1 cationic surfactant, 0.5 mol L -1 LiCl and pH 2.60 at 30°C), iron(II) was determined in the range 0.1-0.5 lg mL -1 with a detection limit of 0.019 lg mL -1 and a relative standard deviation (n = 6) 1.02% for 0.2 lg mL -1 Fe(II). The influence of foreign ions on the accuracy of the results was investigated. The developed method is extremely sensitive, selective and simple. The method was applied successfully to the determination of iron in the herbal pharmaceutical and synthetic samples. The results showed good agreement with those obtained by atomic absorption spectrophotometry.

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Study of the bromide oxidation by bromate in zwitterionic micellar solutions

Rodrı́guez

Graciani

Muñoz

et al. 2000

Int J of Chemical Kinetics

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The redox reaction Br -ϩ BrO 3has been studied in aqueous zwitterionic micellar solutions of N-tetradecyl-N, N-dimethyl-3-ammonio-1-propanesulfonate, SB3-14, and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate, SB3-16. A simple expression for the observed rate constant, k obs , based on the pseudophase model, could explain the influences of changes in the surfactant concentration on k obs . The kinetic effect of added NaClO 4 on the reaction rate in SB3-14 micellar solutions has also been studied. They were rationalized by considering the binding of the perchlorate anions to the sulfobetaine micelles and their competition with the reactive bromide ions for the micellar surface.

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Micellar Effects on the Reaction S2O82−+ Fe(CN)4(bpy)2−

Cited by 10 publications

References 20 publications

Study of the reaction Fe(CN)5(4-CNpy)3? + S2O82? in aqueous salt and micellar solutions

Study of the reaction Fe(CN)5(4-CNpy)3? + S2O82? in aqueous salt and micellar solutions

Surfactant‐Mediated Catalytic Determination of Fe(II) in Herbal and Pharmaceutical Products

Study of the bromide oxidation by bromate in zwitterionic micellar solutions

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