Cell membrane as a model for the design of ion-active nanostructured supramolecular systems

The synthesis and polymerization of six AB(3) tapered self-assembling methacrylate monomers (5a, 5b, 5c,5d, 17a, and 17b) based on first generation alkyl substituted benzyl ether monodendrons (i.e., minidendrons) containing oligooxyethylene units at their focal point and the polymerizable group on their periphery are described. The corresponding polymers (6a, 6b, 6c, 6d, 18a, and 18b) self-assemble and subsequently self-organize in supramolecular networks that form a 2-D hexagonal lattice. This network consists of a continuous phase based on a paraffin barrier material perforated in a hexagonal array by ion-active channels constructed from the oligooxyethylenic units protected by the aromatic groups of the taper. Complexation of the oligooxyethylene channels of 6a-d with LiCF(3)SO(3) salt enhances the thermal stability of their hexagonal columnar (phi(h)) liquid crystalline phase. The enhancement of the thermal stability of the phi(h) phase of both monomers and polymers up to 86 degrees C is also achieved by shifting the placement of the polymerizable group from the 3 position to the 4 position of the 3,4,5-trisubstituted AB(3) benzoate monodendrons. The design of these macromolecules was inspired by the bilayer fluid mosaic structure of the cell membrane. The lipid bilayer of the cell membrane that acts in its ordered state as a barrier to the passage of polar molecules was replaced with the paraffinic barrier, while the protein-based ionic channels were replaced with oligooxyethylenic-based channels. The resulted supramolecular material has the mechanical integrity required for the design of ion-active nanostructured supramolecular systems.