The equilibrium distribution of cations between Dowex 50 sulfocationite and an aqueous solution of nicotinic acid and iron chloride at pH 1−3 was studied experimentally. The concentrations of protons, iron cations, and their complexes with nicotinic acid in the ionite significantly depend on pH of solution. The content of doubly charged iron complexes with nicotinic acid in the polymer can reach the value corresponding to the total ion exchange capacity of the ionite. A method is proposed for calculating the counterionic composition of the sulfocationite phase from the equilibrium constants of binary exchange of the sulfocationite proton for the iron cation and of the protonated form of nicotinic acid or the doubly charged iron complex with nicotinic acid.

Выполнено экспериментальное исследование равновесного распределения катионов в системе: сульфокатионит Dowex 50 и водный раствор пиколиновой кислоты и хлорида железа. В фазе сульфокатионита Dowex 50 получена высокая концентрация комплексов железа и пиколиновой кислоты. Показана возможность расчета равновесного противоионного состава сульфокатионита Dowex 50 по константам равновесия бинарных ионных обменов и известному составу раствора. Сульфокатионит Dowex 50 предложен в качестве контейнера для биологически активных препаратов на основе пиколиновой кислоты и катионов Fe 3+ .

The sorption of 2-pyridinecarboxylic, 3-pyridinecarboxylic, and 4-pyridinecarboxylic acids by polystyrene sulfonic acid type cation exchange resin Dowex 50W-X8 and Dowex 50W-X4 from aqueous solutions was studied. Based on the analysis of the FT-IR spectra of acids, sulfates of their protonated forms, and an acid-saturated cation exchange resin, it was shown that pyridinecarboxylic acid is in the protonated form in the cation exchange phase. The equilibrium constants of sorption proceeding with participation of pyridinecarboxylic acid, sulfonic cation exchange resin, and proton were calculated according to experimental data on the equilibrium distribution of acids in the aqueous solution–cation exchange resin system. The values of the equilibrium constant of the cation exchange of the sulfonic ion-exchange resin proton by the pyridinecarboxylic acid cation from solution lie in the range 3.2–4.4. The equilibrium constants of sorption of 2-pyridinecarboxylic acid molecules are 25 dm3 mol–1, they increase to 195–220 dm3 mol–1 for 4-pyridinecarboxylic acid, and reach 320–330 dm3 mol–1 for 3-pyridinecarboxylic acid. Changing the amount of the cross-linking agent (from 4 to 8

The possibility of immobilizing benzocaine in polymeric nanocontainers made of sulfonated cation exchangers, i.e., sulfonated polycalixarene and KU-23 30/100, was studied. The desorption kinetics of neutral and cationic benzocaine from the polymeric nanocontainers provided the desired drug-release pharmacokinetics upon peroral administration.

The theory of the ion exchange kinetics on strong acid cationites with the participation of weak electrolytes is discussed. The kinetics of desorption of benzocaine in the protonated and molecular forms from strong acid cationites, sulfonated polycalixarene, and KU-23 30/100 sulfocationite, is studied experimentally. It is shown that the flow of protonated benzocaine from cationite upon desorption proceeding by the ion-exchange mechanism is more intense than upon desorption of nonionized benzocaine molecules. It is established that the diffusion coefficient of benzocaine cations is (1.21 ± 0.23) × 10−12 m2/s in KU-23 30/100 sulfocation and (0.65 ± 0.06) × 10−13 m2/s in sulfonated polycalixarene, while the diffusion coefficient of benzocaine molecules is (0.65 ± 0.15) × 10−14 m2/s in sulfonated polycalixarene.

Исследована кинетика восстановления эфиров n-нитробензойной кислоты в нанореакторах на основе сульфированных сетчатых полимеров, содержащих нанодисперсный палладий. Рассчитаны кинетические характеристики процесса гидрирования ароматических нитросоединений.

The kinetics of the reduction of p-nitrobenzoic acid esters in nanoreactors based on sulfonated network polymers containing nanodispersed palladium was studied. The kinetic characteristics of the hydrogenation of aromatic nitro compounds were calculated.

We compare the ion exchange selectivity of phenol-type sorbents based on phenol formaldehyde resins, products of condensation of diatomic phenols with formaldehyde, and crosslinked polymer based on C-phenyl[4]resorcinarene resin, for cesium and rubidium ions. It is shown that phenol formaldehyde sorbents are the ones most selective. The interaction of alkali metal cations with the anion of calix[4]arene is investigated via quantum-chemical modeling. It is shown that the selectivity toward cesium and rubidium ions in ion exchangers of the phenolic type is not due to specific interactions of ions with phenolic groups.

Crosslinked polymers based on macrocyclic polyphenols, in particular, metacyclophaneoctols, can serve as the matrices of proton-conducting membranes and electrode materials for a new generation of chemical current sources. Coking coal conversion products are the main source of raw materials for the production of metacyclophaneoctols. Here, a conductometric and potentiometric study of the properties of polymetacyclophaneoctols and metal-polymer nanocomposites on their basis was performed. It was found that the electrical conduction of the H form of polysulfonatotetraphenylmetacyclophaneoctol (0.2 S/cm) corresponds to the performance characteristics of the best proton-exchange membranes of hydrogen fuel cells. The nanocomposite on a polysulfonatotet-rametacyclophaneoctol matrix containing 5% palladium metal nanoparticles was proposed as a material for the negative electrode of a hydrogen fuel cell. Polysulfonatotetraphenylmetacyclophaneoctol containing 2% palladium nanoparticles and 10% silver was chosen as a material for the positive electrode, at which oxygen is reduced.

A new polymer was prepared by etherifi cation of phenolic OH groups in polysulfotetraphenylcalix[4]resorcinolarene. It exhibits high ion-exchange capacity and is less hydrophilic than the starting polymer.

The catalytic reduction processes of nitrobenzene derivatives occurring in the nanoreactors based on cross-linked polymers containing nanoparticles of palladium have been studied. Kinetic characteristics of precursors of anesthetic drugs hydrogenation were calculated.

The nanoreactor synthesis of pyridinecarboxylic acids—the precursors of biologically active compounds—was performed by the catalytic oxidation of coal tar components. The composite of Pd or Pd and Ag nanoparticles on a matrix of sulfonated polycalixresorcinarene was used as a nanoreactor. It was found that nicotinic acid can be obtained by the nanoreactor oxidation of β-picoline with cerium(IV) sulfate at 1.013 · 10−5 Pa and 25–30°C.

The electrical conductivity of a polymer based on tetraphenylcalix[4]resorcinarene in the form of H + , Na + , Li + , Ag + , and Ba 2+ cations was measured, and the self-diffusion coefficients and activation energies of metal cation diffusion in the polymer phase were calculated. It was found that the specific conductivity of the polymer in the form of Ba 2+ cations was 0.004 S/cm, increased to 0.01 S/cm when the polymer was in the form of singly-charged metal cations, and became as high as 0.2 S/cm when the polymer was transformed into the H form. It was shown that the self-diffusion coefficients of metal cations in the polymer phase increased in the sequence Ba 2+ < Ag + , Li + < Na + . The conclusion was made that, over the temperature range 298–333 K, the activation energy of metal cation diffusion in polymer was 14–15 kJ/mol and did not obviously depend on the cation charge.