Rapid energy transfer in light-harvesting small dendrimers

The energy-transfer dynamics from peripheries to cores was investigated in two series of light-harvesting small dendrimers. In a star-shaped stilbenoid phthalocyanine having image-conjugated peripheries, a highly efficient and rapid energy transfer occurs. The core photoluminescence (PL) of a phenylene-based dendrimer, which has the effective overlap between the periphery PL and the core-absorption spectra, gives rise to a faster rise time than the periphery PL decay time. In these small dendrimers, it was found that short-range interactions caused by the wave function overlap between peripheries and cores become important, in which a rapid relaxation from the Frank–Condon states in the peripheries should be responsible for the rapid energy transfer.