Novel self-assembling system based on resorcinarene and cationic surfactant

Mixed association of calix[4]resorcinarene with ethyl sulfonate groups on the lower rim and dimethylaminomethyl groups on the upper rim (CR) and cationic surfactant 4-aza-1-hexadecyl-azoniabicyclo[2.2.2]octane bromide (DABCO-16) is studied by methods of tensiometry, conductometry, potentiometry and NMR spectroscopy at fixed CR concentration and varied surfactant concentration. Beyond ca. 0.4 mM of DABCO-16, mixed aggregates enriched by CR are proved to be formed due to electrostatic forces, while beyond ca. 5 mM, aggregates enriched by surfactant occur due to the hydrophobic effect. Spectrophotometry monitoring of the solubilization of a hydrophobic dye, Orange OT, demonstrated that only the second type of mixed aggregate enriched by DABCO-16 is capable of binding the organic probe, while the mixed system where the surfactant is a minor component shows no binding capacity towards Orange OT. This finding can be used for the design of nanocontainers with controllable binding/release properties.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

Closed polymer containers based on phenylboronic esters of resorcinarenes

Novel polymer nanospheres (p(SRA-B)) were prepared by cross-linking a sulfonated resorcinarene (SRA) with phenylboronic acid. p(SRA-B) shows good stability in water and can be used as a nanocontainer for the pH- and glucose-controlled substrate release. Fluorescent dyes (fluorescein, pyrene and 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt) were successfully loaded into p(SRA-B). The release of dye is achieved by lowering the pH value to 3 or by adding glucose

A Supramolecular Amphiphile Based on Calix[4]resorcinarene and Cationic Surfactant for Controlled Self-Assembly

A novel supramolecular system based on calix[4]­resorcinarene sulfonatoalkylated at the lower rim and piperidine-methylated at the upper rim and the cationic surfactant hexadecyl-1-azonia-4-azobicyclo[2.2.2]­octane bromide was investigated by methods of NMR, tensiometry, conductometry, potentiometry, dynamic light scattering, X-ray powder diffraction, and spectral probe techniques. Both types of molecules were found to self-associate in aqueous solution, with aggregates of different morphology formed. Importantly, a supramolecular amphiphilic binary system with controlled structure and binding behavior could be fabricated. At high surfactant concentration, the formation of its own aggregates takes place. In the systems with the excess of cyclophane the supramolecular amphiphiles are formed, which, in turn, self-assemble in particles with a large hydrophobic core. Thereby the structure of supramolecular species is determined by relative fractions of components and, hence, could be selectively controlled. The found properties can be used for the design of nanocontainers with the controlled cavity size