The Nature of Aqueous Solutions of a Cationic Calix[4]arene: A Comparative Study of Dye–Calixarene and Dye–Surfactant Interactions

Abstract

Among different types of calixarenes, the water–soluble ones are of especial interestbecause of their possible applications in biochemical research. In order to elucidate the natureof aqueous solutions of a cationic amphiphilic calixarene, substituted tetrapropoxycalix[4]arene bearing hydrophilic choline groups at the upper rim, we studied vis–spectroscopically the influence of the above system on the acid–base behavior of threeindicator dyes, namely, 2,4-dinitrophenol, bromophenol blue, and N,N/-dioctadecylrhodamine,at constant ionic strength of 0.05 M, maintained with NaCl addition. Simultaneously,‘apparent’ ionization constants, Kaa , of the same dyes were determined in the presence ofcommon cationic surfactant micelles. Within the concentration range from 1.0×10–5 to 0.01 M,the aforementioned water–soluble calixarene displays effects similar to those of micelles ofcetyltrimethylammonium bromide (or chloride). The shifts of the absorption and emissionbands in the visible region, as well as the alterations of the Kaa values against the ‘aqueous’ones appeared to be very similar in aqueous solutions of both calix[4]arene and cationicsurfactant. A conclusion can be made about aggregation (or association), i.e., micelleformation of the cationic calix[4]arene under study.

Virus‐Sized DNA Nanoparticles for Gene Delivery Based on Micelles of Cationic Calixarenes

“…The first example from this family, CX3, has already been synthesized and characterized before. [31] However, its studies showed that it forms micellar structures only at rather high concentrations (CMC near 2.5 mm) in water. [30] To improve the self-assembling ability of this molecule, we extended the length of the alkyl chains from propyl to octyl.…”

A theoretical study of the global and local electrophilicity, nucleophilicity, polarizability and QTAIM theory for calix[4]arene-gas interaction

“…In the literature, Furel et al. [ 35 , 36 ] have been studied the experimental infrared spectrum of the free CX[4] molecule. The experimental spectrum shows O–H stretching vibration in the region varying from 2900 to 3500 cm −1 .…”

Evaluation of a cationic calix[4]arene: Solubilization and self-aggregation ability

“…Taking into account self-aggregation of the studied aminocalix (Arimori et al, 1995), it is likely that drug solubilization by aminocalix is based on micellar effects. The interaction between CAs with a similar ionic struc- ture and dyes (Mchedlov-Petrossyan et al, 2006 has been studies and it has been proposed that the possible mechanism of interactions is due to the micellar effect rather than docking of the indicator dyes into calixarene cavities. Thus, relation of aminocalix's solubilizing ability to drug interaction with lipophilic vesicle regions should not be excluded.…”