Energy transfer in supramolecular oligo(p-phenylene vinylene) architectures.

Oligo(p-phenylene vinylene)s (OPVs) are ideal model compds. for studying electronic materials based on org. matter. By making use of non-covalent interactions, well-defined OPV aggregates are obtained in dodecane soln. These aggregates are helically organized and have a sharp melting temp., which increases upon elongating the conjugated backbone. The high interchromophoric order causes the exciton dynamics in the stacks to resemble those of polymer thin films. Blending OPVs of different length results in the formation of mixed aggregates, in which efficient energy transfer occurs from short to longer oligomers. At low doping levels, the longer oligomers are present as molecularly dissolved species inside the donor aggregates while they interact upon increasing the acceptor content. Using ethylene oxide in stead of dodecyl side chains enables the formation of OPV assemblies in an aq. environment. By incorporating cyano-substituted OPV acceptors into these aggregates, efficient energy transfer is obsd. to the trap mols.