Effect of short-chained sodium alkylsulfate micelles on the kinetics of metal complex formation

1981 ◽  
Vol 59 (9) ◽  
pp. 1361-1367 ◽  
Author(s):  
Paul D. I. Fletcher ◽  
Vincent C. Reinsborough
Keyword(s):  
Alkyl Chain ◽  
Binding Constants ◽  
Micelle Formation ◽  
Reaction Rates ◽  
Bidentate Ligand ◽  
Alkyl Chain Length ◽  
Stopped Flow ◽  
Micellar Solutions ◽  
Kinetics Of ◽  
Micelle Surface

The kinetics of the reaction between Niaq2+ and the bidentate ligand pyridine-2-azo-p-dimethylaniline (PADA) have been investigated in micellar solutions of sodium decyl-, octyl-, and hexylsulfates using the stopped-flow technique. The rate of enhancement decreased with decreasing alkyl-chain length and from the Berezin or Robinson model could be quantitatively related to the independently measured binding constants of Ni2+ ion and PADA to the micelle surface. The dramatic effect of micelles upon the reaction rates in different directions of the Ni2+/PADA and the Ni2+/murexide reactions served as sensitive indicators of the cmc even at the very limit of micelle formation which relatively concentrated sodium hexylsulfate solutions represent.

Distribution and reactivity of gallates toward galvinoxyl radicals in SDS micellar solutions — Effect of the alkyl chain length

2011 ◽  
Vol 89 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Raquel Bridi ◽  
Carolina Aliaga ◽  
Alexis Aspée ◽  
Elsa Abuin ◽  
Eduardo Lissi
Keyword(s):  
Chain Length ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Alkyl Chain ◽  
Sodium Dodecyl ◽  
Homogeneous Solution ◽  
Reaction Rates ◽  
Alkyl Chain Length ◽  
Micellar Solutions ◽  
Methylene Group

In this work, we have evaluated the reactivity of methyl gallate, propyl gallate, and n-octyl gallate toward galvinoxyl radicals in homogeneous solution (ethanol) and sodium dodecyl sulfate micelles. In ethanol, the rate of galvinoxyl consumption was independent of the gallate’s alkyl chain length. On the other hand, reaction rates in micelles were dependent on the length of the gallate alkyl chain. Measurements of the rate of the reaction at different pH show that, even at pH 7.0, the reaction mainly involves the monodeprotonated anionic form of the gallates. Plots of reaction rates as a function of the surfactant concentration allowed us to evaluate the distribution of the gallates (KGH) and an apparent rate constant defined by the product between the intramicellar rate constant of the anion ([Formula: see text]) and its partition constant ([Formula: see text]). The values of the increment of the apparent rate constant per methylene group in the alkyl chain strongly suggest that intramicellar rate constant values are independent of the alkyl chain length. This points to a similar intramicellar localization of the phenolate moiety in the three gallates considered.

Effects of Alkyl Chain Length on Synergetic Adsorption and Micelle Formation in Homologous Cationic Surfactant Mixtures

Langmuir ◽  
2005 ◽  
Vol 21 (18) ◽  
pp. 8131-8137 ◽  
Author(s):  
Hiroki Matsubara ◽  
Takayuki Nakano ◽  
Takashi Matsuda ◽  
Takanori Takiue ◽  
Makoto Aratono
Keyword(s):  
Chain Length ◽  
Cationic Surfactant ◽  
Alkyl Chain ◽  
Micelle Formation ◽  
Alkyl Chain Length ◽  
Surfactant Mixtures

Heparin Effects (And Mechanisms) In The α2-Antithrombin Inactivation Of Serine Proteases--Thrombin, Plasmin, And Trypsin

1981 ◽  
Author(s):  
Gerald F Smith ◽  
Jacqueline L Sundboom
Keyword(s):  
Serine Proteases ◽  
Physiological Role ◽  
Binding Constants ◽  
Reaction Rates ◽  
Heparin Therapy ◽  
Common Mechanism ◽  
High Concentration ◽  
Protein Substrates ◽  
Kinetics Of ◽  
Very High

It is important to elucidate the effects of heparin on the α2-antithrombin (ATIII) inactivation of serine proteases in order to understand the pharmacological activity of heparin. We have studied the enzyme kinetics of the ATIII inactivation of these proteases, and the effects of heparin on these interactions, using a common amide peptide substrate and protein substrates. We also studied the interactions of heparin with the three proteases.We conclude that the mechanism of the catalytic effect of heparin (observed at 0. 005 unit/ml) toward the thrombin- ATIII reaction is different from the mechanism whereby heparin (only at very high concentration, e.g., 10 unit/ml) can induce an enhanced rate in the plasmin-ATIII reaction. We conclude that the first mechanism involves a heparinthrombin complex, while the mechanism with plasmin involves a heparin-ATIII complex which forms only at high heparin concentrations. This is consistent with known appropriate binding constants. We found that heparin has no effect on the very rapid inactivation of trypsin by ATIII. We further conclude that there is no common mechanism whereby clinically relevant levels of heparin cause general enhanced ATIII-protease reaction rates.We suggest ATIII depletion during heparin therapy might be avoided by using low heparin levels, which would not allow heparin-ATIII complexes to form, yet which would catalyze the thrombin-ATIII reaction. Our finding that ATIII inactivates trypsin at a rate similar to the heparin-catalyzed thrombin-ATIII reaction suggests a physiological role for ATIII in the control of trypsin-like enzymes.

Rate enhancement of the nickel(II)-pada complex formation in sodium alkanesulfonate micellar solutions

1982 ◽  
Vol 35 (1) ◽  
pp. 15 ◽  
Author(s):  
JR Hicks ◽  
VC Reinsborough
Keyword(s):  
Complex Formation ◽  
Chain Length ◽  
Micellar Solution ◽  
Binding Constants ◽  
Bidentate Ligand ◽  
Kinetic Constants ◽  
Micellar Solutions ◽  
Reaction Volume ◽  
Rate Of Reaction ◽  
Alkyl Sulfates

Sodium alkanesulfonates (C9, C8, C7, and C6) in micellar solution have been used to enhance the rate of reaction between Niaq2+ and the bidentate ligand pyridine-2-azo-p-dimethylaniline (pada) at 298.2 K. A Berezin-like model has been used to account for the observed kinetic constants in terms of the binding constants of each of the reagents to the micelles and the reaction volume and the concentration of the micellar surfactant. For a given chain length, the alkanesulfonates are about 25 % less effective than alkyl sulfates in promoting the rate of reaction and the model accounts for this successfully.

scholarly journals Kinetics of Reduction of Colloidal MnO2 by Glyphosate in Aqueous and Micellar Media

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Uzma Aisha ◽  
Qamruzzaman ◽  
M. Z. A. Rafiquee
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Binding Constants ◽  
Reaction Rates ◽  
Lauryl Sulfate ◽  
Micellar Media ◽  
First Order Kinetics ◽  
Rate Of Reaction ◽  
Colloidal Mno2 ◽  
Kinetics Of ◽  
Kinetics Of Reduction

The kinetics of the reduction of colloidal MnO2 by glyphosate has been investigated spectrophotometrically in an aqueous and micellar (cetyltrimethylammonium bromide, sodium lauryl sulfate) media. The reaction follows first-order kinetics with respect to colloidal MnO2 in both the aqueous and micellar media. The rate of oxidation increases with increase in [glyphosate] in the lower concentration range but becomes independent at its higher concentrations. The addition of both the anionic (NaLS) and cationic (CTAB) micelles increased the rate of reduction of colloidal MnO2 by glyphosate while the nonionic TX-100 micelles did not influence the rate of reaction. In both aqueous and micellar media, the oxidation of glyphosate occurs through its adsorption over colloidal MnO2 surface. The reaction in micellar media was treated by considering the pseudophase model. The values of reaction rates and binding constants in the presence of micelles were determined.

scholarly journals Effect of the alkyl chain length on micelle formation for bis(N-alkyl-N,N-dimethylethylammonium)ether dibromides

2019 ◽  
Vol 22 (5) ◽  
pp. 386-392 ◽  
Author(s):  
Bogumil Brycki ◽  
Adrianna Szulc ◽  
Hanna Koenig ◽  
Iwona Kowalczyk ◽  
Tomasz Pospieszny ◽  
...  
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Micelle Formation ◽  
Alkyl Chain Length

Influence of the Ligand Alkyl Chain Length on the Solubility, Aqueous Speciation, and Kinetics of Substitution Reactions of Water-Soluble M3S4 (M = Mo, W) Clusters Bearing Hydroxyalkyl Diphosphines

2013 ◽  
Vol 52 (15) ◽  
pp. 8713-8722 ◽  
Author(s):  
Tomás F. Beltrán ◽  
Rosa Llusar ◽  
Maxim Sokolov ◽  
Manuel G. Basallote ◽  
M. Jesús Fernández-Trujillo ◽  
...  
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Water Soluble ◽  
Substitution Reactions ◽  
Kinetics Of

scholarly journals REDOX REACTIONS INVOLVING N-ALKYL-DIHYDRONICOTINAMIDES

1994 ◽  
Vol 2 (2) ◽  
pp. 121-135
Author(s):  
Nadir Ana Wiederkehr
Keyword(s):  
Methylene Blue ◽  
Electron Transfer ◽  
Cytochrome C ◽  
Redox Reactions ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Transfer Reactions ◽  
Micellar Media ◽  
Electron Transfer Reactions ◽  
Kinetics Of

Electron transfer reactions involving a series of N-alkyl-dihydronicotinamides (R-NAH) as donors were studied in homogenous solvents and in micellar media. In particular, the redox chemistry and kinetics of the reduction of methylene blue and cytochrome-C, by varying the alkyl chain length (R = C4, C8, C12) were investigated The schemes proposed for functionalized surfactants of nicotinamide suggest photochemical conversion based on light-induced electron-transfer reactions.

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