Search

Polymeric aggregates (~100 nm) based on polydiacetylenic acid doped with the luminescent TbIII complexes with the tetra- and bis-1,3-diketonate derivatives of calix[4]arenes with nonyl substituents at the lower rims are considered as potential nanosensors. The obtained colloidally stable mixed aggregates can generate a substrate-induced luminescent response in aqueous solutions of 2,2´,6´,2´´-terpyridine in the micromolar concentration range due to the coordination of the latter by TbIII ions on the aggregate surface.

A composite for the extraction of lanthanide ions from strongly acidic media by temperature-induced phase separation was designed based on the nonionic surfactant Triton X-100 and new phosphine oxide derivatives. The dependence of the efficiency and selectivity of micellar extraction on the length of the hydrophobic substituent at the P=O group is determined by both the influence of hydrophobic substituents on the electron-donor capacity of the P=O group and the solubility of phosphine oxides in aqueous and micellar phases. The nitric acid concentration was found to influence the efficiency of extraction of lanthanide ions by phosphine oxides with different structures. An increase in the concentration of nitric acid in an aqueous medium from 0.1 to 1 mol L−1 leads to a decrease in the degree of extraction by water-soluble derivatives and a substantial increase in the degree of extraction by phosphine oxides, which are soluble only in the micellar phase of Triton X-100.

A new approach to the synthesis of 2-hydroxyaryl-alkenylphosphine oxides and dialkyl (diaryl)-(2-methyl-4-oxopent-2-yl)phosphine oxides was developed that involves an interaction of Grignard reagents with available benzo[e]-1,2-oxaphosphorinines and 1,2-oxaphospholene-2-oxide. This approach allows obtaining target compounds with a high yield. The synthesized phosphine oxides proved to be highly efficient extractants in the micellar extraction of some lanthanides from the nitric acid media.

A procedure of micellar extraction of the lanthanide ions (La, Gd, and Lu) from nitric acid media based on the use of novel phosphine oxide derivatives is developed. In the micellar extraction, complexes of the lanthanide ions with the extractant in the ratio of 1 : 2 (metal : extractant) form. The dependence of the selectivity of extraction on the length of hydrophobic radicals attached to the P=O group was shown. The conditions of the selective micellar extraction in the series La > Gd > Lu with the use of an extractant containing octyl substituents at the P=O group were found.

The extraction of gadolinium(III) and lanthanum(III) ions at the cloud point is studied in Triton X100 micellar solutions in a wide range of pH. In the absence of chelating agents, lanthanum(III) and gadolinium(III) ions are unselectively extracted at pH > 6. It is shown that the use of p-sulfonatothiacalyx[6(8)]arenes as chelating agents noticeably enhances the degree of extraction at pH 2–6. The composition and stability of lanthanum-p-sulfonatothiacalyx[n]arene complexes (n = 4, 6, 8) are estimated in a wide range of pH by pH-potentiometry. The degree of Gd3+ and La3+ ions extraction, which is performed at the cloud points employing calyxarene macrocycles of different sizes, is depended on the acidity of a medium.

The aggregation and catalytic effect in the reaction of hydrolytic decomposition of phosphorous acid esters are studied for series of systems such as calixarene (CA)-sodium dodecyl sulfate (SDS), CA-poly(ethylene imine) (PEI), SDS-PEI, and CA-SDS-PEI. Using dynamic light scattering, sizes of aggregates are determined, cloud point is estimated, and catalytic effect is studied. Data obtained are consistent with the assumption of the joint aggregation in systems studied. The possibility of the passage from 20-fold inhibiting effect to the catalysis (higher than the order of magnitude) of studied reaction by the immobilization of anionic nanoaggregates (nanoreactors) on a catalytically active polymer matrix is demonstrated. The possibility of the passage from microheterogeneous to heterogeneous system and the separation of catalyst from the products are established.

Concentration range of solubilization of calix[4]resorcinarene (H8L) in sodium dodecyl sulfate (SDS) micelles was found. The interaction of the deprotonated form of H8L (tetraanions [H4L]4−) with tetramethylammonium (TMA) and choline cations in micellar solutions of SDS was studied by pH-metry and NMR spectroscopy. The concentration dependences of the change in the cloud point in a multicomponent system TMA (choline)-[H4L]4-SDS-tetrabutylammonium bromide were determined. A correlation of these dependences with host-guest binding processes was found. The sharp change in the cloud points of the corresponding micellar solutions in concentration regions of TMA (0-5·10−4 mol L−1) and choline (0–1.1· 10−3 mol L−1) is caused by the formation of inclusion complexes TMA (choline)-[H4L]4− at the interface of the aqueous and micellar pseudophases.

Solubilization of calix [4]resorcinarenes (Cn) with a varied length of hydrophobic substituents (R =Me, Pr, C5H11, C7H15, C9H19, and C11H23) in aqueous solutions of oxyethylated dodecanol Brij-35 was studied by the solubility method and 1D and 2D 1H NMR spectroscopy. The solubilization of Cn in micellar solutions of Brij-35 is caused by the formation of mixed Cn-Brij-35 aggregates and is weakened substantially with the elongation of R. It was shown by pH-metry and 1D 1H NMR spectroscopy that the receptor properties of the Cn anions toward the tetramethylammonium cations in the mixed aggregates differ substantially from those for the monomeric molecules in aqueous-organic and aqueous solutions. In particular, the binding of the tetramethylammonium cations does not result in screening of their N-Me fragments with the cyclophane cavity of the receptor.

Regularities of solubilization of calix[4]resorcinarenes (H8L) with the variable length of hydrophobic radicals (R = CH3, C3H7, C5H11, C7H15, C8H17, C9H19, C11H23) by the micelles of nonionic surfactants Triton X-100 and Triton X-405 in aqueous solutions were studied using solubility measurements. It was found that the solubilization capacity of surfactant micelles with respect to H8L and [H4L]4– depends on the extension (thickness) of their polar layers. It was shown by means of potentiometric titration that, in solutions of nonionic surfactants, the constants of the interaction between tetraanions [H4L]4– and tetrametylammonium ions depend on the structure and concentration of nonionic surfactants and the hydrophobicity of H8L molecules. A change in the affinity of the [H4L]4– anions for protons and tetramethylammonium cations in nonionic surfactant solutions was revealed in relation to the length of substituents R and reagent concentrations.

Solubility and acid–base properties of calix[4]resorcinarene (H8L) in aqueous solutions of nonionic surfactants Triton X-100, Triton X-405, and Brij-35, as well as isopropanol were studied by pH-potentiometry. The dependence of the amount of a nonionic surfactant necessary to dissolve H8L on the length of ethylene oxide chain was found. The dissociation constants of macrocycle for the first four steps are low sensitive to the medium nature (micellar or water–alcohol solutions). Complexation ability of the [H8 – nL]n– anions with respect to tetramethyl- and tetraethylammonium, N-methylpyridinium, and [Co(En)2(C2O4) ]+ cations was studied by pH-potentiometry. A noticeable increase in the selectivity of guest–host binding was found on going from aqueous or water–alcohol to micellar solutions.

It is found that a sodium dodecyl sulfate-Brij 35 binary mixture inhibits the alkaline hydrolysis of O-ethyl-O-p-nitrophenylchloromethylphosphonate. Tensiometric data and variations in cloud point suggest the synergistic effect of the above surfactants caused by the formation of mixed micelles. The method of solvatochromic probe E T(30) shows that the micropolarity of a medium rises at the sites of localization of substrates solubilized in micelles with an increase in ionic surfactant fraction in mixed aggregates. Variations in micellization properties, micropolarity, and surface potential with the composition of the binary mixture of the surfactants influence the catalytic properties of mixed micelles with respect to the examined reaction.