A Semi-Empirical Spectrophotometric (SESp) Method for the Indirect Determination of the Ratio of Cationic Micellar Binding Constants of Counterions X^|^ndash; and Br^|^ndash; (KX/KBr)

Khan, M. Niyaz; Yusof, Nor Saadah Mohd; Razak, Norazizah A.

doi:10.5650/jos.62.695

Cited by 5 publications

(4 citation statements)

References 40 publications

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“…This can be attributed to the polarizability difference, as well as the electronegativity of the halogen substituent [31]. The values of K Br X or R Br X increase with the decrease and increase in electronegativity [27] d Ref. [28] e Ref.…”

Section: Resultsmentioning

confidence: 99%

“…It has been shown that the extent of the catalytic effects of CTABr/MX/ H 2 O can give the value of the ion exchange constant, K Br X [26]. The values of K Br X for X = mono-substituted halobenzoate ions at constant [CTABr] T (where CTABr and [] T represent cetyltrimethylammonium bromide and total concentration, respectively) have been determined and listed elsewhere [27][28][29][30][31]. Furthermore, these counterions are known to affect the structural features of cationic micelles nanoparticles [32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

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Counterion‐Induced Cationic Flexible Nanoparticle Catalytic of Piperidinolysis of Phenyl Salicylate

Noh

Khalid

Ariffin

et al. 2017

J Surfact & Detergents

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The removal of PSa− from bulk aqueous phase to the pseudo‐micellar phase by halobenzoate counterion X is responsible for the monotonic increase in kobs (pseudo first‐order rate constants) with the increase in the values of [MX] where MX = sodium salts of 2‐, and 4‐halobenzoic acids. The values of ion exchange constants, KnormalXBr or RnormalXBr for X = 2‐ and 4‐halobenzoate ions in the presence of tetradecyltrimethylammonium bromide (TTABr) were calculated from the apparent catalytic rate constants, Xkcat which represent the catalytic effect of CFN. Larger values of KnormalXBr or RnormalXBr were observed for X = 4‐halobenzoate ions than that for X = 2‐halobenzoate ions due to isomeric factors. The values of KnormalXBr or RnormalXBr determined in the presence of TTABr were compared with previously determined KnormalXBr or RnormalXBr values in the presence of cetyltrimethylammonium bromide (CTABr). The values of KnormalXBr or RnormalXBr are nearly 8 ~ 9‐fold larger for 4‐IBz−, 4‐BrBz− and 4‐ClBz− compared to the respective values of X = 2‐IBz−, 2‐BrBz− and 2‐ClBz−. The values of KnormalXBr or RnormalXBr for X = 4‐FBz− is nearly 3‐fold larger than that for X = 2‐FBz−. The values of KnormalXBr or RnormalXBr for X = 2‐ and 4‐halobenzoates are significantly smaller in the presence of TTABr than these in the presence of CTABr nanoparticles.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Counterion‐Induced Cationic Flexible Nanoparticle Catalytic of Piperidinolysis of Phenyl Salicylate

Noh

Khalid

Ariffin

et al. 2017

J Surfact & Detergents

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“…Comparison of the values of K X Br or R X Br , obtained in the present study and reported values for different MX a Unless otherwise noted, CTABr represents the cationic surfactant and the semi-empirical kinetic/semiempirical spectrophotometric method was used to determine K X Br /R X Br at 35 ºC. Ref [42]…”

mentioning

confidence: 77%

Kinetics and Mechanism of Alkaline Hydrolysis of N-(o-Aminophenyl)Phthalimide in the Presence and Absence of Cationic Micelles and Sodium Salts of Aliphatic Acids

Ahmad

Fagge

Sim

et al. 2018

Progress in Reaction Kinetics and Mechanism

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Pseudo first-order rate constants, k obs, for the alkaline hydrolysis of N-( o-aminophenyl) phthalimide, obtained at constant [CTABr]T (total concentration of cetyltrimethylammonium bromide) and varying concentrations of inert salt MX (MX = sodium formate, sodium acetate, sodium propanoate, sodium butyrate, sodium valerate and sodium hexanoate) follow the relationship: [Formula: see text], where θ and KX/S are empirical constants and S = HO-. The values of KX/S for each aliphatic acid decrease with an increase in [CTABr]T. This relationship gives an empirical constant whose magnitude is the measure of the ability of an ion, X-, to expel another counterion S-, from the cationic micellar surface to the bulk aqueous phase. The values of the empirical constant, KX/S, are used to derive the ion exchange constant, KBrX.

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“…The values of K Br Cl (= 2.7 ± 0.1 and 2.6 ± 0.3 for M + = Na + and K + respectively) may be compared with the reported values of 2-3 [68], 2.7 [69] and 5 [70] obtained by the use of different physicochemical techniques. The values of K X/S or K X/S n can be determined using either semi-empirical kinetic (SEK) [5,14,31,67] or semi-empirical spectrophotometric (SESp) [71] methods. The SEK method involves kinetic measurements of an appropriate reaction probe molecule while the SESp method involves an appropriate spectrophotometric probe molecule.…”

Section: Estimation Of Ion Exchange Constants K Xmentioning

confidence: 99%

Kinetics and Mechanism of Cationic Micelle/Flexible Nanoparticle Catalysis: A Review

Khan

Fagge

2018

Progress in Reaction Kinetics and Mechanism

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The aqueous surfactant (Surf) solution at [Surf] > cmc (critical micelle concentration) contains flexible micelles/nanoparticles. These particles form a pseudophase of different shapes and sizes where the medium polarity decreases as the distance increases from the exterior region of the interface of the Surf/H 2 O particle towards its furthest interior region. Flexible nanoparticles (FNs) catalyse a variety of chemical and biochemical reactions. FN catalysis involves both positive catalysis (i.e. rate increase) and negative catalysis (i.e. rate decrease). This article describes the mechanistic details of these catalyses at the molecular level, which reveals the molecular origin of these catalyses. Effects of inert counterionic salts (MX) on the rates of bimolecular reactions (with one of the reactants as reactive counterion) in the presence of ionic FNs/micelles may result in either positive or negative catalysis. The kinetics of cationic FN (Surf/MX/H 2 O)-catalysed bimolecular reactions (with nonionic and anionic reactants) provide kinetic parameters which can be used to determine an ion exchange constant or the ratio of the binding constants of counterions.

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A Semi-Empirical Spectrophotometric (SESp) Method for the Indirect Determination of the Ratio of Cationic Micellar Binding Constants of Counterions X^|^ndash; and Br^|^ndash; (KX/KBr)

Cited by 5 publications

References 40 publications

Counterion‐Induced Cationic Flexible Nanoparticle Catalytic of Piperidinolysis of Phenyl Salicylate

Counterion‐Induced Cationic Flexible Nanoparticle Catalytic of Piperidinolysis of Phenyl Salicylate

Kinetics and Mechanism of Alkaline Hydrolysis of N-(o-Aminophenyl)Phthalimide in the Presence and Absence of Cationic Micelles and Sodium Salts of Aliphatic Acids

Kinetics and Mechanism of Cationic Micelle/Flexible Nanoparticle Catalysis: A Review

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