| Abstract
| - A series of small dendritic structures containing one of two efficient multiphoton absorbing dyes at the peripheryand a nile red derivative at the core have been synthesized. These molecules display efficient (>96%)fluorescence resonance energy transfer (FRET) from the periphery to the core on selective excitation of thetwo-photon absorbing chromophore by either UV (linear absorption) or high-intensity IR (nonlinear absorption)radiation. In addition, a significant increase in core emission is observed on excitation of the peripheralchromophores, compared to direct excitation of the core. This “antenna effect” essentially doubles betweenincreasing dendrimer generations within a series. The combination of the ability of the peripheral chromophoresto absorb high-intensity IR radiation, coupled with a very efficient energy transfer process and a significantincrease in the fluorescence of the acceptor chromophore, makes these molecules potentially useful for avariety of applications, including optical power limiting and biomedical imaging.
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