Antenna Effects of Aromatic Dendrons and Their Luminescence Applications

Abstract

Remarkable concentration of the photon energy absorbed by aromatic dendritic scaffolds toward the focal point (i.e., antenna effects) is one of the most distinct features of the dendritic macromolecules. Poly(benzyl ether) dendron is used as effective antennas in various luminescence systems. For example, organic photosensitive moieties (azo linkage, porphyrin), poly(phenyleneethynylene), metal cations (Tb³⁺, Eu³⁺, Ru²⁺), and semiconductor nanocrystals (CdSe) are surrounded by the dendrons. “Energy funnels” are designed using poly(phenylacetylene) dendrimer and a multiporphyrin array arranged in a dendritic scaffold to demonstrate effective photon energy harvesting toward the focal point. The importance of symmetric structure for the antenna effect has been revealed both in the whole shape of the macromolecule and the dendritic repeating unit. Luminescence applications are discussed (e.g., temperature-responding gel, fluoroimmunoassay reagent).