Light harvesting and energy transfer in laser-dye-labeled poly(aryl ether) dendrimers

The photophysical properties of a series of laser-dye-labeled poly(aryl ether) dendrimers, generations 1-4, have been determined. The dendrimers act as extremely efficient light-harvesting antennae capable of transferring light energy through space from their periphery to their core. The light-harvesting ability of these molecules increases with generation due to an increase in the number of peripheral chromophores. The energy-transfer efficiency was found to be quantitative for generations 1-3, with only a slight decrease observed for the fourth generation (similar to 93%). Due to the high extinction coefficients and fluorescence quantum yields of the chromophores and the efficient intramolecular energy transfer of the dendritic assemblies, these macromolecules have the potential to become integral components of molecular photonic devices.