Dendrimers possessing coumarin-2 dyes at the periphery, and either a coumarin-343 or a heptathiophene dye at the core, have been studied by femtosecond transient absorption spectroscopy in order to elucidate energytransfer rate constants. These measurements indicated that energy transfer occurs with average correlation times of less than 6 ps in the first three generations, and slows to a correlation time of approximately 18 ps in the fourth. The transient spectral features arising from excitation of the peripheral donor chromophores at 330 nm are described. Additionally, these measurements provide a quantitative comparison between observed and theoretical energy-transfer rate constants (kET), indicating a close correlation of the experimental results with Forster theory.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry