Self-Assembly of Diacetylene-Bridged Phenylenevinylene Oligomers in Water and Organic Solvents

Rodlike pi-conjugated molecules in which two OPV fragments are connected through a diacetylene bond self-assemble in aqueous and organic media. Optical spectroscopy and AFM measurements indicated that, in water, strong hydrophobic interactions between pi-cores promote aggregation into robust, uniform micellar structures. In contrast, in apolar solvents, a fibrilar morphology is obtained by coiling of columnar stacks. These stacks are formed in a nucleation-elongation process with degrees of cooperativity of 0.006, that is influenced by the low rotation barriers around the sigma-bonds in the diacetylene linker.