Energy transfer in organic dendrimer antenna funnel and anti-funnel supermolecules

The photophysics of exciton localization and energy transfer are examined in two unique classes of phenylacetylene dendrimers. One set of supermolecules is observed to efficiently and rapidly funnel absorbed radiation toward the molecular locus, while a slight change in molecular structure creates an effective 'anti-funnel', greatly reducing the efficiency of energy trapping. Lifetime-based and steady state fluorescence studies are used to determine the rates of intramolecular energy transfer and to glean information on molecular geometry and intermolecular interactions in two solvents.