Luidmila S. Yakimova

Selective stepwise oxidation of 1,4-decamethoxypillar[5]arene

For the first time, the 1H and 13C{1H} NMR data were classified and analyzed for the pillar[5]arenes with one, two, three and five 1,4-benzoquinone fragments obtained in good yields. The empirical relationships established make it possible to define the relative position of the quinone and aryl fragments to each other in the oxidation products of any pillar[n]arenes.

MALDI-TOF MS and Morphology Studies of Thiacalixarene-Silsesquioxane Products of Oligo- and Polycondensation

For the first time condensed silsesquioxane derivatives of tetratrialkoxysilyl compounds have been characterized by MALDI-TOF mass spectrometry. Tetrasubstituted p-tert-butyl thiacalix[4]arene derivatives containing organosilicon fragments with variable stereochemistry were chosen as organosilicon compounds for polycondensation. Information obtained from mass spectra was used to deduce both the structures of oligomeric derivatives, as well as the structure of silsesquioxane framework. The morphology of formed polysilsesquioxanes was investigated by scanning and transmission electron microscopy.

Hybrid thiacalix[4]arene/SiO2 nanoparticles: synthesis and selective adsorption of aniline and phenol nitro derivatives

Hybrid thiacalix[4]arene/SiO2 nanoparticles based on a thiacalixarene derivative containing simultaneously three benzyl and one triethoxysilyl groups at the lower rim and silicon dioxide nanopowder were obtained for the first time. The adsorbing properties of the synthesized hybrid organo-inorganic nanoparticles in relation to aromatic guest molecules (2,4,6trinitrophenol, 2,4-dinitrophenol, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 2,4-dinitroaniline) were studied in comparison with unmodified silicon dioxide particles.

Chemoselective acylation of monosubstituted thiacalix[4]arene with di-tert-butyl dicarbonate

Mono-, di-, and tetrasubstituted derivatives of p-tert-butylthiacalix[4]arene containing tert-butylcarbamate, tert-butylcarbonate, and tert-butyl fragments have been prepared for the first time. Depending on the reaction conditions (reagents ratio, temperature, and the presence of a base), the interaction of the monoamine derivative of p-tert-butylthiacalix[4]arene with di-tert-butyl dicarbonate can lead to the formation of mono-, di-, and tetrasubstituted products.

Hybrid multicyclophanes based on thiacalix[4]arene and pillar[5]arene: synthesis and influence on the formation of polyaniline

For the first time, fragments of a pillar[5]arene were spatially preorganized with a thiacalix[4]arene core in a single multimacrocyclic structure. It was shown that the synthesized hybrid multicyclophanes bind aniline and do not interact with p-toluenesulfonic acid. Supramolecular assistance of the synthesized multicyclophanes in oxidative polymerization of aniline in aqueous p-toluenesulfonic acid solutions was studied. It was found that the use of the multicyclophane template in the reaction of the oxidative polymerization of aniline led to the formation of emeraldine with a higher molecular weight and a similar conductivity (1–2 mSm cm−1), which formed more stable emeraldine dispersions in acetone in comparison with traditionally obtained polyaniline.

Polyfunctional branched nitrogen-containing p - tert -butylthiacalix[4]arene derivatives as efficient agents for packaging calf thymus DNA

Polyfunctional p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim with nitrogen-containing fragments in the cone, partial cone, and 1,3-alternate conformations were investigated in the processes of calf thymus DNA packaging. The influence of the macrocycle structure and composition on their ability to pack DNA into nano-sized particles was considered. UV spectroscopy and dynamic light scattering results showed that the synthesized p-tert-butylthiacalix[4]arenes functionalized at the lower rim with polyamine fragments in the cone and 1,3-alternate conformations can compact calf thymus DNA into nanosized particles (<100 nm). A new type of synthetic receptors based on the 1,3-alternate stereoisomer of p-tert-butylthiacalix[4]arene with ester, hydroxy, and tertiary amino groups was suggested for packaging DNA to nanoparticles of 51—85 nm in size.

Systems Based on Calixarenes as the Basis for the Creation of Catalysts and Nanocontainers

Increasing efficiency of chemical catalysis, as well as new directions for the control of chemical reactions, is of great importance in the further progress of chemical technologies and the pharmaceutical industry. One of the modern methods developed to solve this problem assumes carrying out reactions in nanoreactors, in which the reagents are concentrated in compartments of few nanometers in size. Currently, various micro- and nanostructured media, such as amphiphilic macrocyclic compounds (including calixarenes, resorcinarenes, and cyclodextrins) and micellar solutions and emulsions, are used as nanoreactors. This chapter describes systematized data on reactions in solutions containing various calixarene and resorcinarene derivatives, which increase the rate of a large number of reactions by acting as nanoreactors. Usually, the type of functional substituent determines the rate of reaction, for example, its controllable increase or decrease.