MONOMOLECULAR LAYERS OF CRYPTOPHANES AT THE AIR-WATER-INTERFACE

The cryptophanes represent a family of hollow molecules with an ovoid shape (13 to 16 angstrom in mean diameter) which are capable of complexing in a selective.fashion neutral and charged species ranging in size from methane to acetylcholine. We report that certain cryptophanes reversibly form monomolecular layers at the air-water interface, without the need for adding long hydrocarbon chains to their structure. This behaviour, which is rather unexpected for molecules of this shape, may allow the construction of new 2D-organized assemblies capable of recognition towards selected molecular species. The amphiphilic character of these cryptophanes is believed to originate from an appropriate balance between the number of oxygens and of carbons covering their external surface.