Helical and Flat Structures from Chiral Dendronized Rectangular Oligo(phenylene ethynylene)s

The synthesis of two chiral amphiphiles and their self-assembling features in solution and onto surfaces is reported. The different degree of interdigitation of the paraffinic substituents has an enormous influence in the chirality of the aggregates. Thus, while oligo(phenylene ethynylene) 1 shows a bisignated Cotton effect in solution and P-type helices onto surfaces, compound 2 lacks in any dichroic response at room temperature and self-assembles into flat ribbons.