The paper presents new symmetric and asymmetric cationic imidazole-triazole amines. Their aggregation behavior in water using spectrofluorimetry (with pyrene and eosin Y probes), UV spectroscopy, and dynamic light scattering was studied. It was demonstrated that all of the compounds form positively charged nanoassociates. For the asymmetric amphiphilic derivatives, an increase in the length of the alkyl tail was found to result in a decrease in the critical micelle concentration, as well as the formation of a more hydrophobic core of aggregates. The interaction of compounds with DNA was studied using competitive displacement of ethidium bromide, fluorescence lifetime analysis, UV spectroscopy, circular dichroism spectroscopy, nanoparticle tracking analysis and zeta potential measurements. A mixed binding mechanism involving electrostatic and hydrophobic interactions was established. Compounds with a symmetrical imidazole-triazole structure and a tetradecyl tail were the most effective inverting its charge. These results demonstrate the physicochemical properties favorable for further exploration in nucleic acid compaction.

For the first time asymmetric and symmetric carboxytriazoleimidazolium derivatives with different structures were synthesized. The critical micellization concentration (CMC) value was estimated using a pyrene fluorescent probe and the solubility of Orange OT. The complexation ability of carboxytriazoleimidazolium derivatives toward bovine serum albumin (BSA) has been investigated by various physico-chemical methods: fluorescence spectroscopy, electrophoretic light scattering and circular dichroism. The effect of the oxo-bridge and the presence of a hydrophobic fragment in the structure of the molecules and its influence on their aggregation properties and interaction with BSA has also been studied. According to the fluorescence data, only in the case of the asymmetric derivatives with long alkyl fragments a shift of the BSA emission maximum is observed, indicating a change in the BSA microenvironment. The secondary structure of BSA remains virtually unchanged in the presence of carboxytriazoleimidazolium derivatives, as shown by circular dichroism. No significant changes in the structure of BSA were observed in the presence of zwitterionic compounds with an oxo-bridge at concentrations where fluorescence quenching occurs, as shown by time-resolved fluorescence measurements. Electrophoretic light scattering showed a recharging of BSA from a negative to a positive zeta potential in the presence of amphiphilic derivatives.

Efficient catalytic systems for various organic transformations in green solvents, especially water, are in great demand. Catalytically active bis-NHC complexes of palladium(II) based on imidazole-4,5-dicarboxylic acid with different lipophilicities were obtained. The synthesis of imidazolium salts was complicated by the formation of side products of nucleophilic substitution by iodide ions in the Menshutkin reaction involving alkyl iodides, which was successfully resolved by using alkyl tosylates. The synthesis of bis-NHC complexes of palladium(II) was carried out in situ using Pd(OAc)2 and KI from imidazolium tosylate salts. The structures of all compounds were well-characterized by a complex of modern physical methods. Typical for gemini surfactants, imidazolium salts aggregate in water to form submicron 200 nm (in the case of di-butyl salt) or compact 6 nm (in the case of di-tetradecyl salt) particles. The catalytic activity of the complexes and systems in situ with Pd(OAc)2 in the hydrogenation reaction of nitroaromatics has been studied. The complex with butyl substituents was found to be superior to known catalytic systems in the reduction of p-nitrophenol (kapp = 1.53 min-1). According to microscopy data, after reduction palladium nanoparticles remained uniformly distributed in the butyl complex, while a lipophilic shell in the tetradecyl complex prevented the access of water-soluble regents to Pd centers. However, the lipophilic tetradecyl complex is more active in the reduction of water-insoluble p-ethylnitrobenzene and in cross-coupling reactions using water-insoluble lipophilic aryl halides due to the combination of micellar and metal complex catalysis. Our results provide insight into amphiphilic NHC palladium complexes as promising catalytic systems for aqueous media.

In the present work, a first-generation dendron, based on imidazole-4,5-dipropargyl-diamide, was synthesized using the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. By alkylation of imidazole-4,5-dipropargyl-diamide with dibromopropane, a bis-imidazole core was obtained and used for the CuAAC-based synthesis of G0 and G1 dendrimers containing terminal OH groups. The structures and compositions of all substances were determined using modern physical methods including two-dimensional NMR and high-resolution mass spectrometry.

Two dinuclear double oxygen-bridged iron(III) complexes made of the Fe-2(mu(2)-OR)(2) diamond-core cluster resulting from the coordination between iron(III) cations with calix[4]arene ligands and bearing two lower-rim-appended salicylideneamine (4) or o-methoxy-salicylideneamine coordinating sites (5), connected to the macrocyclic platform via three methylene bridges and displaying a salen-type coordination pocket, were synthesized and characterized using single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), high-resolution mass spectrometry (HRESI-MS), IR, TG-DSC and EA techniques. Independent of the presence of the o-methoxy group in the salicylideneamine moieties, the as-formed complexes contained two nonequivalent iron(III) atoms, both adopting a distorted octahedral coordination N2O4-environment but differing in the cis and trans positions of the nitrogen atoms within the metal coordination sphere, as attested by single-crystal X-ray diffraction and DFT-B3LYP calculations. The possible reason for the observed coordination mode of the macrocyclic ligands is their conformational behavior upon coordination with Fe(III) cations, as confirmed by DFT-B3LYP analysis. Fe-57 M & ouml;ssbauer spectroscopy study showed that both Fe(III) atoms were present in high spin states at room temperature and at 80 K in the studied coordination compounds. The methoxy groups located at the ortho position of the salicylideneamine coordinating fragments were observed to influence the energy of the frontier orbitals, resulting in an increase in the bandgap energy from 1.97 eV to 2.07 eV, as experimentally established by solid-state voltammetry study of 4(2)-Fe-2 exp and 5(2)-Fe-2 exp, respectively. The interplay between the steric and electronic factors, emerging from the o-methoxy group within coordinating salicylideneamine moieties, seemed to have a negligible effect on the electronic properties of the prepared clusters but significantly impacted the frontier orbital energy distribution, according to both experimental data and theoretical calculations.

An overview of the main scientific achievements of Russian universities in the field of organic chemistry over the period 2018–2023 is presented.

The synthesis of tetrasubstituted thiacalix[4]arene derivatives 2 and 3 in the 1,3-alternate conformation functionalized with azo and sulfo fragments on the lower rim with different distances between the macrocyclic platform and functional groups, is presented. Host-guest complexes were obtained by synthesized ligands 2b and 3bwith cationic dyes: rhodamine B (RhB), rhodamine 6G (Rh6G), and rhodamine 123 (Rh123). The structure of the supramolecular complexes was determined by 1H NMR, UV and fluorescence spectroscopy. Based on fluorescent titration data, it was revealed that Rh6G binds most efficiently to macrocycles compared to other dyes. The binding constants for compound 3b containing a naphthalene fragment with other dyes were two orders of magnitude higher than for derivative 2b. In the dye-macrocycle system the different degrees of binding constants correlate with UV spectroscopy data: for the complex with 2b-Rh6G a hypochromic effect and a bathochromic shift are observed, while the addition of macrocycle 2b to other dyes causes virtually no changes in the absorption spectra. The stoichiometry of the synthesized complexes was determined by the Job's plots. In the complexes of compound 2b with all dyes was indeterminate composition but in the case of compound 3b complexes were 1:1. The mechanism of dye luminescence quenching was studied using the 3b-Rh6G system as an example. In the presence of macrocycles2b and 3b, a high-field shift of the Rh6G proton signals is observed, caused by the influence of ring currents of the aromatic nuclei of calixarene, which was shown using NMR spectroscopy. At the same time, for the 3b-Rh6G system, smaller values of dye signal shifts were observed compared to the 2b-Rh6G complex, which is apparently due to the lower degree of immersion of the dye into the macrocycle cavity. The possibility of dissociation of binary macrocycle-dye systems in the presence of components contained in biological environment (lysine, arginine, proline, glucose, adenosine-5'-triphosphate, urea, creatinine, bovine serum albumin and metal ions: Na+, K+, Mg2+, Ca2+, Zn2+, Fe3+) was studied. It has been shown that for systems with a high Ka value there is no competitive complexation with objects present in biological environment.

Among the seven-membered ketals of pyridoxine containing hydroxymethyl groups in various positions of the pyridine ring, an unusual ability of selenium dioxide to catalyze the reaction of nucleophilic substitution of the hydroxyl group by N,O-nucleophiles was found. Quantum chemical calculations have shown the possibility of the formation of selenium dioxide adducts with substrates and the formation of reactive intermediates—ortho- and para-pyridinone methides. The antioxidant and antimycotic activity of the obtained compounds was determined.

The present work is devoted to the synthesis and analysis of the physicochemical properties of new functionalized asymmetric Gemini surfactants. Herein, alkyl- and azide-substituted surfactants with symmetric and asymmetric substituents were synthesized by using the click-reaction method. The critical aggregation concentration values of Gemini surfactants were determined. The binding processes of functionalized Gemini surfactants with bovine serum albumin were evaluated by fluorescence spectroscopy. Also, using the temperature dependences of the binding constants, the mechanism of Gemini surfactants binding with bovine serum albumin was studied. The hydrodynamic diameters of the formed bovine serum albumin/surfactant aggregates were analyzed. Based on electrophoretic light scattering, the ability of the synthesized Gemini surfactants to form associates was analyzed. The possibility of changing the mechanism of interaction in the 15c/bovine serum albumin system was shown. Based on the results obtained using different light scattering techniques and fluorescence spectroscopy, the mechanisms of interaction between bovine serum albumin and surfactants were determined.

A first-generation triazole-containing dendron with hydroxypropyltriazole groups and a tetraethylene glycol linker was synthesized for the first time by stepwise modification of gallic acid by the azide–alkyne cycloaddition reaction. The structures of all intermediate compounds have been proven by advanced physical methods. It has been found that, due to the high mobility of the bromine atom in the benzylic position, the use of bromomethylene gallic acid derivatives in the synthesis of triazole-containing dendrons gives by-products resulting from alkylation of the bases used in the reaction (triethylamine and diisopropylethylamine).

Triazole derivatives of fluorescein-containing N,N-dimethylaminopropyl fragments and their ammonium salts were synthesized with yields of 74–85%. The resulting compounds exhibit fluorescent properties in the green region of the visible spectrum. The critical aggregation concentration (CAC) was estimated using a pyrene fluorescent probe corresponding to a range of 0.28–1.43 mM, and at concentrations above the CAC, the compounds form stable aggregates ranging from 165 to 202 nm. A relative quantum yield of 5–24% has been calculated based on fluorescence and UV spectra. The best value is shown by a derivative containing a tetradecyl substituent. When studying the photocatalytic properties of synthesized compounds through the reaction between N-substituted 1,2,3,4-tetrahydroisoquinoline and malonic ester, the mono-tetradecyl derivative demonstrated the best results. According to gas chromatography–mass spectrometry (GC-MS) data, the conversion of the initial heterocycle reached 95%. Therefore, these resulting compounds have the potential to act as an effective photocatalysts.

1st generation dendrimers containing polar hydroxyl and both 1st and 2nd generation dendrimers with oxyethyl groups were obtained using a convergent approach and CuAAC reaction. Three types of dendrimer nuclei were utilized: the macrocyclic nucleus of calix[4]arene bearing 2/4 dendron and 2/4 alkyl fragments and the non-macrocyclic analog of calixarene bearing a one dendron/alkyl fragment. Nanoparticle tracking analysis reveals self-organization of the obtained dendrimers in aqueous solution into submicron/nanoparticles with sizes of 80-250 nm. The lowest CAC values in the series are possessed by tetra-alkyl substituted calix[4]arenes (1.6-1.8 mu M), while the low molecular weight analog of calixarenes possesses a CAC one to two orders of magnitude larger (44-350 mu M). When the obtained dendrimers were used as stabilizers of palladium nanoparticles, the formation of spherical palladium nanodendrites (50-60 nm) consisting of metal Pd and PdO was determined using TEM and SAED. The micellar effect of using stabilized palladium particles with dendrimers at concentrations higher than their CAC in the catalysis of Suzuki reactions and nitro aromatics reduction is shown. In the p-nitrophenol reduction reaction, the catalytic activity of the obtained systems (the maximum kapp in series was 0.47 min-1) exceeds many known Pd-based systems. 1st and 2nd generation amphiphilic dendrimers were obtained. Spherical palladium nanodendrites stabilized by amphiphilic dendrimers show excellent catalytic activities in coupling and reduction of aromatics in water.

Supramolecular chemistry is one of the most actively developing areas of modern science. The inexhaustible interest in supramolecular structures stems from their ability to self-assemble, that allows to create systems modeling processes occurring in living organisms, as well as to use nature's approaches to create such functional systems as molecular receptors, catalysts, nanoreactors, molecular machines, etc. For this reason, special attention of researchers working in the field of supramolecular chemistry is focused on amphiphilic molecules which are able to form highly ordered molecular ensembles in aqueous solutions. Amphiphilic macrocycles are of particular interest. A distinctive feature of amphiphilic macrocycles is their ability to high molecular recognition due to multipoint interactions. The modular approach of click chemistry (especially the copper-catalysed cycloaddition reaction of azides and alkynes, CuAAC), proposed by Sharpless in 2001 [1], is extremely suitable for the construction of amphiphilic structures based on macrocycles due to its exceptional tolerance to the introduced functional groups, allowing the direct introduction of even ionized fragments without the use of protecting groups. So, it is possible to synthesize libraries of various amphiphilic compounds by the changing of azide- or alkyne-containing structural modules [2,3] (Figure 3). Ակնարկային աշխատանքը ներկայացնում է համընդհանուր սինթետիկ մոտեցում մի շարք ամֆիֆիլային (թիա)կալիքս[4]արենների պատրաստմանը, ներառյալ երկֆունկցիոնալ ամֆիֆիլները՝ պոլիմերվող դիացետիլենային հատվածներով, CuAAC-պոլիմերացվող ամֆիֆիլներ, ինչպես նաև NHC–Pd(II) համալիրներ՝ օգտագործելով CuAAC/Մենշուտկինի ռեակցիան։ Հոդվածում բերվում են ստացված համակարգերի կիրառության մի քանի ուղղություններ և բնագավառներ: В настоящей работе представлен универсальный синтетический подход для получения ряда амфифильных (тиа)каликс[4]аренов, включающих бифункциональные амфифилы с полимеризуемыми диацетиленовыми фрагментами, CuAAC-полимеризуемые амфифилы, а также комплексы NHC – Pd(II) путем использование реакции CuAAC/Меншуткина. В обзоре продемонстрированы различные направления применения полученных систем.

For the first time, dendrimers based on thiacalix[4]arenes bearing imidazolium dendrons on one side and alkyl fragments on another side of the macrocyclic platform and symmetrical dendrimers with four dendrons on both sides were synthesized. Dendrons consist of gallic acid-based branches functionalized with imidazolium and triazolium groups. The physicochemical properties of the dendrimers such as micellar concentration (CMC), size, and solubilization capacity were measured. Novel dendrimers exhibit high binding efficiency with calf thymus DNA (ctDNA) as revealed by fluorescence quenching of the DNA-EtBr complex in the presence of macrocycles. Dendrimers have been used as supports for Pd nanoparticles, which show high catalytic activity for the reduction of nitroaromatic compounds.

Today, the modification of the organic molecules using the copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC) is of great interest, as evidenced by the Nobel Prize in Chemistry awarded in 2022 to the founder of “click” chemistry. Supramolecular chemistry, in turn, is one of the actively developing branches of modern science. Using the CuAAC approach is a very convenient method to obtain new macrocyclic structures of interest. This review focuses on the use of the modular “click”-chemistry approach for the synthesis of various triazole derivatives of thiacalix[4]arenes and calix[4]arenes as well as general routes for the synthesis of their precursors (azides and alkynes). Examples of some functional systems based on triazole-containing macrocycles, such as chemosensors, multicalixarenes, amphiphilic calixarenes as well as examples of the use of triazole calixarenes for bioapplications are described.

Four new NiII, CoII, ZnII, and CuII complexes with the promising anti-tuberculosis drug (E/Z)-N′-((5-Hydroxy-3,4-bis(hydroxymethyl)-6-methylpyridin-2-yl)methylene)-isonicotino-hydrazide (LH) were synthesized and characterized by structural methods: single-crystal X-ray diffraction, vibrational spectroscopy, and mass spectrometry. The NiII, CoII, and ZnII metal ions form only amorphous phases with various morphologies according to mass spectrometry and IR spectroscopy. The CuII forms a crystalline 1D coordination polymer with the relative formula {[CuLCl]·0.5H2O}∞1. Even though the LH ligand in the crystalline state includes a mixture of E-/Z-isomers, only the tautomeric iminol E-/Z-form is coordinated by CuII in the crystal. The copper(II) complex crystallizes in the monoclinic P21/n space group with the corresponding cell parameters a = 16.3539(11) Å, b = 12.2647(6) Å, and c = 17.4916(10) Å; α = 90°, β = 108.431(7)°, and γ = 90°. DFT calculations showed that the Z-isomer of the LH ligand in solution has the lowest formation energy due to intramolecular hydrogen bonds. According to the quantum chemical calculations, the coordination environment of the CuII atom during the transfer of the molecule into the solution remains the same as in the crystal, except for the polymeric bond, namely, distorted trigonal bipyramidal. Some of the complexes investigated can be used as effective sensors in biosystems.

A methodology for synthesizing 1st generation triazole-containing dendrons based on epichlorohydrin with different functional groups was developed using a Cu-catalyzed azide-alkyne cycloaddition reaction (CuAAC) reaction. The proposed methodology uses simple reagents and can serve as a basis for the synthesis of dendrons and dendrimers of higher generations. High reaction yields as well as the cost of starting reagents, make the preparation of such compounds economically and environmentally favorable.

Calix[4]arene derivatives containing two or four O -propargyl moieties are capable of undergoing reductive depropargylation in the presence of hydrazine hydrate. The propargyl groups are removed in the form of 4,5-dihydro-1 H -pyrazoles, which allowed proposing a reasonable mechanism for the depropargylation. The propargyl group can be used as the protection for the selective nitration at the distal positions of the upper rim of di- O -propargyl-substituted calix[4]arene and p - tert -butylcalix[4]arene. The reduction of nitro group at the upper rim proceeds along with the depropargylation upon the addition of a nickel catalyst to the reaction mixture with hydrazine hydrate, which leads to calixarenamines containing free hydroxy groups.

The properties of amphiphilic calix[4]arenes and thiacalix[4]arenes containing the same polar N-tetrahydroxyethylimidazolium groups on one side and alkyl fragments on the other side of the macrocyclic platform are shown. Critical aggregation concentration (CAC) values were studied with three methods: solubilization of Orange OT (a); binding of pyrene (b); interaction with eosin Y (c). Absorbance and emission plots of interaction with eosin Y were effectively calculated by a sigmoidal Boltzmann type function. Different solubilizing ability, interaction with a dianion dye, and selectivity of the of binary system macrocycle-eosin Y respectively to adenosine phosphates (mono-, di-or triphosphate) are shown.