Part I. Self-assembly of amphiphilic dendritic dipeptides into functional helical pores. Part II. Expression of molecular chirality and two-dimensional supramolecular self-assembly at the liquid-solid interface

Part I describes the synthesis and structural analysis of a library of amphiphilic dendritic dipeptides that self-assemble in solution and in bulk through a complex recognition process into helical pores. It is found that the molecular recognition and self-assembly process is sufficiently robust to tolerate a range of modifications to the amphiphile, and preliminary proton transport measurements establish that the pores are functional. The internal structure and stability of the porous structure self-assembled from these dendritic dipeptides is programmed by the stereochemistry and protecting groups of the dipeptide, by the number of methylenic units from the alkyl groups of the dendron, and by the primary structure of the dendron attached to the dipeptide. It is expected that this class of self-assembling dendrimers will allow the design of a variety of biologically inspired systems with functional properties arising from their porous structure. Part II investigates the two-dimensional ordering of chiral and achiral monodendrons at the liquid-solid interface. The chiral molecules self-assemble into extended arrays of dimers. As expected, the R enantiomer forms the mirror image type pattern of the chiral two-dimensional structure formed by the S enantiomer. A racemic mixture applied from solution onto the substrate undergoes spontaneous segregation: the enantiomers separate on the surface and appear in different domains. In contrast to the chiral molecules, the achiral analogue self-assembles into cyclic tetramers. Moreover, the pattern formed by the achiral molecule strongly depends on the solvent used. By the appropriate solvent choice, the distance between the potential supramolecular containers can be influenced