Ultrathin monolayers and vesicular membranes from calix[6]arenes

Abstract

p-terf-Butylcalix[6]arene produces stable monolayers at the air-water interface having a limiting area of 260 A2/molecule and a film thickness of ca. 10 A. Complete removal of the p-tert-butyl groups affords a unique vesicle-forming surfactant, calix[6]arene, which forms membranes having an apparent thickness of ca. 20 ± 5 A.Phospholipid bilayer membranes have attracted considerable attention over the past 25 years as models for biological membranes, microcapsules, and devices for solar energy conversion.3 45"6 In a series of pioneering papers published in the late 1970s and early 1980s, Kunitake and co-workers extended the range of vesicle-forming surfac-(1) Supported by the Division of Basic Energy Sciences of the Department of Energy (DE-FG02-85ER-13403).

Self‐Assembly of Amphiphilic Calix[4]arenes in Aqueous Solution

“…As in previous studies, multilayer vesicles are not observed. [6,8,9] It must be stressed at this point that, unlike in other studies, the vesicles form spontaneously, i.e., simply after dissolution in aqueous solvents without further treatment, such as sonication etc.…”

“…As amphiphilic calixarenes can interact with aqueous systems, they are of particular interest for biological and environmental applications, e.g., wastewater treatment, medical diagnosis, and highly sensitive and selective sensors. [2,3] There have thus been some studies on amphiphilic calixarenes in aqueous solution, [1,[4][5][6][7][8][9][10][11][12][13][14][15] but few calixarene-based gels have been reported, [16,17] although such gels could, for example, enable the incorporation of pharmaceutically active compounds into ointments. In the same context, liquid-crystalline calixarenes are interesting, but so far only a few calixarene-based LCs have been reported.…”

“…While most of these studies report the formation of micelles, three studies describe the formation of vesicles from calixarenes. [6,8,9] Vesicular structures should attract attention because they may have applications similar to lipid vesicles or self-assembled polymers, which have been widely promoted as, e.g., drug-delivery systems. [28][29][30] The goal of this current study was thus to synthesize amphiphilic calixarenes and to study their self-assembly in aqueous solution.…”

Study on the Film Properties and Recognition for Metal Ions of Calix[4]arenes Derivative by Langmuir Monolayer

“…This phenomenon was also found for the calix [6]arene without the tert-butyl groups. 30 In this view, it was clear that cations complexation occurred at the spreading, i.e. at very large area values, and the [TCA-M] n+ complexes organized themselves upon compression.…”

“…and the hydrophobic interactions between the tert-butyl residues at the upper side of calixarene. 30 It was worthwhile to emphasize that these molecular cross sections concerned the closely packed monomolecular film, i.e. at the end of the monolayer compression and before the collapse of the monolayer.…”