α-Aminophosphonates: Effective carriers for the membrane transport of biorelevant species

The novel lipophilic α-aminophosphonates were synthesized by the Kabachnik-Fields reaction. These compounds exhibited remarkable selectivity as carriers for the membrane transport of the biorelevant species such as α-amino and α-hydroxy acids

P-tert-Butylthiacalix[4]arenes functionalized by N-(4'-nitrophenyl)acetamide and N,N-diethylacetamide fragments: Synthesis and binding of anionic guests

© 2017 Vavilova and Stoikov; Licensee Beilstein-Institut. New p-tert-butylthiacalix[4]arenes, which are mono-, 1,2-di- and tetrasubstituted at the lower rim containing N-(4'- nitrophenyl)acetamide and N,N-diethylacetamide groups in cone and partial cone conformations have been synthesized. Their complexation ability towards a number of tetrabutylammonium salts n-Bu 4 NX (X = F - , Cl - , Br - , I - , CH 3 CO 2 -, H 2 PO 4 - , NO 3 - ) was studied by UV spectroscopy. The effective receptor for the anions studied as well as selective receptors for F-, CH 3 CO 2 - and H 2 PO 4 - ions, which based on the synthesized thiacalix[4]arenes, have been obtained. It was shown that p-tertbutylthiacalix[ 4] arene tetrasubstituted at the lower rim by N-(4'-nitrophenyl)acetamide moieties bonded to the anions studied with association constants within the range of 3.55 × 10 3 -7.94 × 10 5 M -1 . Besides, the binding selectivity for F - , Cl - , CH 3 CO 2 - , and H 2 PO 4 - anions against other anions was in the range of 4.1-223.9. Substituting one or two fragments in the macrocycle with N,Ndiethylacetamide groups significantly reduces the complexation ability of the receptor. In contrast to the 1,3-disubstituted macrocycle containing two N-(4'-nitrophenyl)acetamide moieties, the 1,2-disubstituted thiacalix[4]arene, which contains only one such fragment and a N,N-diethylacetamide moiety, selectively binds F - anions

Tetracarboxylic acids on a thiacalixarene scaffold: Synthesis and binding of dopamine hydrochloride

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018. For the first time thiacalix[4]arene derivatives in 1,3-alternate conformation simultaneously containing amide, carboxyl and hydroxyl groups capable of forming 1:1 stoichiometry complexes with dopamine hydrochloride were obtained. The efficiency of dopamine hydrochloride binding was evaluated by a number of spectral methods. Using the methods of fluorescent, UV-Vis and NMR spectroscopy, the mechanism of interaction of the synthesized macrocycles with dopamine has been studied. It was shown that quenching of dopamine fluorescence by the studied macrocycles is carried out through a static mechanism

P-tert-butyl thiacalix[4]arenes functionalized with amide and hydrazide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations are "smart" building blocks for constructing nanosized structures with metal cations of s-, p-, and d-elements in the organic phase

The ability of p-tert-butyl thiacalix[4]arenes functionalized with tertiary and secondary amide and hydrazide groups at the lower rim in cone, partial cone, and 1,3-alternate conformations to self-assemble and recognize metal ions of s- (Li+,Na+,K+,Cs+), p- (Al 3+, Pb2+)and d- (Fe3+, Co3+, Ni 2+, Cu2+, Ag+, Cd2+, Hg 2+) elements was investigated by picrate extraction method and dynamic light scattering (DLS). DLS was used for determination of the hydrodynamic diameter, polydispersity index, and molecular weight of nanoscale aggregate systems consisting of p-tert-butyl thiacalix[4]arene molecules and metal nitrates. Also for quantitative determination of the dimer shape from the values of molecular weight and the particles size, the Perrin factor (F) was established. It was shown that in most cases the dimers of stereoisomers of p-tert-butyl thiacalix[4]arenes tetra- substituted at the lower rim by secondary amide groups represent the prolate spheroid. © 2009 American Chemical Society

Guanidine-equipped thiacalix[4]arenes: Synthesis, interaction with DNA and aggregation properties

New tetrakis-guanidinium-containing p-tert-butylthiacalix[4]arene forms monodisperse nanoparticles with diameter 44 nm in the concentration range of 40-100 μm. Its association constant with model DNA was evaluated as pK a = 3.96 by fluorescent intercalator displacement assay. © 2014 Mendeleev Communications. All rights reserved

Guanidine-equipped thiacalix[4]arenes: Synthesis, interaction with DNA and aggregation properties

New tetrakis-guanidinium-containing p-tert-butylthiacalix[4]arene forms monodisperse nanoparticles with diameter 44 nm in the concentration range of 40-100 μm. Its association constant with model DNA was evaluated as pK a = 3.96 by fluorescent intercalator displacement assay. © 2014 Mendeleev Communications. All rights reserved

Towards nanomaterials with tubular pores: synthesis and self-assembly of bis-pillar[5]arene

Recently, materials obtained using supramolecular chemistry approaches, and, in particular, spatially preorganized macrocyclic compounds, have attracted close attention of the researchers. Pillar[n]arenes are of special interest due to their tubular spatial structure and macrocyclic cavity. A similar tubular structure is retained in the supramolecular packaging of pillar[5]arene crystals, forming pores. In this study, we developed a block synthetic approach for the preparation of bis-pillar[5]arene containing amide groups. The ability of the synthesized bis-pillar[5]arene to form stable self-associates in solvents of different polarity (CHCl3 and CH3OH) was demonstrated by the DLS method. In trichloromethane at concentration of 1·10–3 M, monodisperse associates with average hydrodynamic diameter of 227 nm (PDI = 0.28) are formed; in methanol, stable associates (1·10–6 M) have an average hydrodynamic diameter of 136 nm (PDI = 0.21). The results obtained can be used to create new supramolecular systems, molecular machines, or capture and detect various organic molecules.

Secondary amine derivatives of p-tert-butylthiacalix[4]arene: Synthesis and molecular recognition of phthalic acid

© ISUCT Publishing. New tetrasubstituted at the lower rim p-tert-butylthiacalix[4]arenes in 1,3-alternate conformation containing 2-, 3-, and 4-picolylamine fragments were synthesized. It was shown that the macrocycles synthesized are able to selectively bind phthalic acid in the series of dicarboxylic (oxalic, malonic, succinic, adipic, glutaric, fumaric, maleic, isophthalic and terephthalic) and hydroxy (glycolic and tartaric) acids

Membrane extraction of organic compounds 3. A new receptor fragment for carboxylate groups based of the calix[4]arene platform

A new type of macrocyclic receptor able to bind organic substrates containing carboxy and carboxylate groups was designed on the basis of 1,3-disubstituted calix[4]arenes. A series of disubstitited calix[4]arenes were prepared in 60-80% yields by selective 1,3-alkylation of p-tert-butylcalix[4]arene. The compounds obtained were tested as carriers for DL-tartaric, glycolic, DL-amygdalic, and DL-glutamic acids through liquid membranes immobilized on a polymer matrix. The structural factors favorable for the transport of these hydrophilic substrates through lipophilic membranes were established

Synthesis and complexation properties of 1,3-alternate stereoisomers of p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim by the phthalimide group

Thiacalix[4]arenes containing the phthalimide group were synthesized and their extraction ability toward monocharged cations (alkali metals and Ag+) was investigated. © 2009