Environmentally Responsive Molecular Baskets:  Unimolecular Mimics of Both Micelles and Reversed Micelles

When four facially amphiphilic cholate derivatives are attached to a tetraaminocalixarene scaffold, the resulting molecule responds to environmental changes by rotation of the cholate units. In polar solvents, the molecule adopts a micellelike conformation with the hydrophilic α-faces of the cholates pointing outward. In nonpolar solvents, it turns inside out, assuming a reversed micellelike conformation with the hydrophobic β-faces pointing outward. Switching between the two conformations is driven by solvophobic interactions and is fully reversible.