An Amphiphilic Molecular Basket Sensitive to Both Solvent Changes and UV Irradiation

Abstract

A molecular basket was obtained by linking four cholate units to a cone-shaped calix[4]arene scaffold through azobenzene spacers. The molecule turns its polar faces inward in nonpolar solvents to bind polar molecules such as sugar derivatives. In polar solvents, the nonpolar faces turn inward, allowing the binding of hydrophobic guests such as pyrene. The molecule can also respond to UV irradiation by trans-cis isomerization of the azobenzene spacers. Response toward both solvents and UV light is fully reversible.

Tuning the Efficiency of Dendritic Nanocarriers using Conformational Constraints

“…Cholic acid‐based cyclophanes7h and oligomers10b are known to bind glycoside derivatives in nonpolar media due to the hydrophilic cavities in the case of cyclophanes and possible reverse micelle‐like conformations of the oligomers. Phenyl β‐ D ‐glucopyranoside has been used as a guest to study glycoside binding of cholic acid‐based oligomers10b, d by NMR spectroscopy. Most of these studies were done in the presence of a small amount of deuterated polar solvent, such as MeOH or dimethyl sulfoxide (DMSO), in CDCl 3 .…”

Biomaterials made of bile acids

“…When the arms are modified with photosensitive groups, the molecules are sensitive to both solvents and UV light [96] . Similar molecules were made as artificial ion channels that can transport K + across the phospholipid bilayers (Figure 18) [97,98] .…”

Facial amphiphiles in molecular recognition: From unusual aggregates to solvophobically driven foldamers

“…Because the interior of this "molecular basket" had polarity always opposite to that of the environment, 20 could bind polar guests in nonpolar solvents and nonpolar guests in polar solvents [40]. When the amide linkages were replaced with azobenzene linkers, the resulting molecule could respond to both solvent polarity and UV irradiation [41]. More recently, a molecule basket with an iron porphyrin as the scaffold (21) displayed solvent-responsive catalytic epoxidation.…”