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Amirov, R. R.; Saprykova, Z. A.; Skvortsova, E. A.; Nugaeva, Z. T.; Улахович, Н. А.

doi:10.1023/a:1013204231746

Cited by 4 publications

(7 citation statements)

References 1 publication

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“…As is seen from Fig. 3, at C SDS ≥ 5-6 mM (curves 7,8), the pH value of the solution decreases. The same threshold value was obtained when titrating a series of 2 mM HOx · 0.5 HCl solutions.…”

Section: Resultsmentioning

confidence: 65%

“…The moment of the micellization (the CMC value) was also determined studying the displacement of H 2 Ox + from the micelles by Na + counterions [7]:…”

Section: Resultsmentioning

confidence: 99%

“…For the processing of titration curves at C SDS > CMC, we applied an approach, according to which, the interaction between the counterions and micelles is considered as a process of complexation [7]. In this case, the head sulfogroups of micelles {DS -} act as ligands.…”

Section: Resultsmentioning

confidence: 99%

“…Their concentration is determined from the C SDS -CMC relationship, where C SDS is the total surfactant concentration. Reactions (1)-(4), (7)-(9) and the interactions of the Na + and H + ions with micelles [7] were included in the mathematical model:…”

Section: Resultsmentioning

confidence: 99%

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Investigation of the state of 8-hydroxyquinoline in aqueous sodium dodecyl sulfate solutions

Ramenskaya

Vladimirova

2005

Colloid J

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The influence of sodium dodecyl sulfate on the dissociation of protonated 8-hydroxyquinoline in aqueous solutions is investigated by potentiometric titration at 293 K. The constants of direct binding of 8-hydroxyquinoline with the monomers and micelles of sodium dodecyl sulfate are determined by the computer simulation of the most probable processes. The role of electrostatic and hydrophobic interactions in the studied system is discussed. 202

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Section: Resultsmentioning

confidence: 65%

“…The moment of the micellization (the CMC value) was also determined studying the displacement of H 2 Ox + from the micelles by Na + counterions [7]:…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the state of 8-hydroxyquinoline in aqueous sodium dodecyl sulfate solutions

Ramenskaya

Vladimirova

2005

Colloid J

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“…The outlook for this approach is confirmed, for example, by the interrelation between the crystallization from water of the compounds of long-chain alkyl sulfate ions with cationic metal complexes having highly ordered layered structure and the unusually high stability (log K > 6) of corresponding ionic associates in dilute aqueous solutions [5,6]. Identically strong associates have been revealed earlier upon the interaction of dodecyl sulfate ions with dications of some diamine [7,8]. Along with the ionic associates of amphiphilic cations with organic counterions, the molecular complexes of cationic surfactants with nonionized aromatic compounds are known existing both in the solid state and in the aqueous solutions [9,10].…”

Section: Introductionmentioning

confidence: 80%

The Association of Picrate Ions with Amphiphilic Cations in Water and Aqueous Solutions of Nonionic Surfactant and β-Cyclodextrin

et al. 2005

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The interaction of cetyltrimethylammonium and cetylpyridinium bromides with picrate ions in water and aqueous solutions of the nonionic surfactant Brij 35 is studied by spectrophotometry. Spectral characteristics of the associates of picrate ions with long-chain nitrogen-containing cations depend on the concentration of a cationic surfactant. When β -cyclodextrin is added, these associates decompose owing to the formation of the strong inclusion complexes of the guest-host type with amphiphilic ions of a cationic surfactant or Brij 35 molecules. The conclusion is made that the driving force for the formation of premicellar aggregates involving picrate ions is the interactions between alkyl chains of surfactant cations. It is shown that, in the presence of various surfactants, as β -cyclodextrin concentration increases, first the molecules of nonionic surfactant and then amphiphilic cations bind with the receptor cavity. It is confirmed that there is no interaction between polyethylene glycol and β -cyclodextrin in aqueous solution.

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Complexation of GdIII with tetra-p-tert-butylthiacalix[4]arenoic acid in micellar media

et al. 2009

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The conditions for the formation of gadolinium(III) complexes possessing high relaxivity with various tetraacid stereoisomers based on p tert butylthiacalix[4]arene in micellar solutions of nonionic surfactants were established. The acid base properties of individual isomers of the ligand were studied by pH metric titration and UV spectroscopy. The composition and stability constants of the solubilized gadolinium(III) complexes with the obtained thiacalixarenes were determined using computer simulation of the NMR relaxation data.Search for high relaxivity metal complexes is one of the most urgent problems in the development of new con trast agents (CAs) for magnetic resonance imaging (MRI), which is a non invasive method for NMR based clinical diagnostics of diseases. 1 At present stable gadolinium(III) complexes with linear and cyclic polyaminopolycarboxy lates are used as CAs. 2 A substantial drawback of these CAs is their low relaxivity factor (3000-5000 L mol -1 s -1 ), which requires the administration of large doses of the drug to the body. Since natural biochemical cycles involv ing Gd 3+ ions are absent, the decrease in the amount of the gadolinium compounds introduced into the body is an important task. This requires the design of contrast agents with high spin lattice relaxivity values (relaxivity is the paramagnetic contribution to the relaxation rate of pro tons of the solvent, R 1 ). 2,3 It is known that one of the methods for increasing the relaxivity of solutions contain ing gadolinium ions is the retardation of their rotation due to the formation of high molecular weight particles (aggregation, complexes) in their composition. 4 It was shown 5,6 than an increase in the relaxivity in solutions of long chain alkyl sulfates in the presence of Gd 3+ ions is caused by the adsorption of the latter on the surface of anionic micelles. The increase in the relaxivity of the gadolinium(III) complex with the diethylenetriaminepen taacetic acid derivative containing the cholesterol moiety as the substituent is due to its self aggregation in wa ter with an increase in the concentration or the incor poration of the complex in mixed aggregates with the non ionic surfactant. 7 Thus, the choice of amphiphilic com pounds capable of self aggregation or incorporation in the composition of mixed aggregates seems to be one of the promising approaches to the design of contrast pre parations.From this point of view, metacyclophanes, in particu lar, calixarenes, whose ability to complexation and hydro philic-lipophilic balance can be varied in a wide range, 8-11 are very promising ligands for chelating rare earth met al ions, including gadolinium(III). 12,13 Meanwhile, in a few known works, 14,15 calixarenes with insufficient lipo philicity were used to design potential contrast agents. However, the influence of the ligand conformation on the stability and relaxation parameters of their complexes with Gd III was not examined. The purpose of the present study is to reveal the influence of the spatial arrangement of the func...

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Untitled

Cited by 4 publications

References 1 publication

Investigation of the state of 8-hydroxyquinoline in aqueous sodium dodecyl sulfate solutions

Investigation of the state of 8-hydroxyquinoline in aqueous sodium dodecyl sulfate solutions

The Association of Picrate Ions with Amphiphilic Cations in Water and Aqueous Solutions of Nonionic Surfactant and β-Cyclodextrin

Complexation of GdIII with tetra-p-tert-butylthiacalix[4]arenoic acid in micellar media

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