Intramolecular triplet energy transfer in benzophenone-{crown ether}-naphthalene system

Bichromophoric compound benzophenone-{crown ether}-naphthalene (Bp-C-Np) was synthesized and its photophysics was examined. Steady state and time-resolved spectroscopic measurements indicate that intramolecular energy transfer from the triplet state of the benzophenone chromophore to the naphthyl group in Bp-C-Np occurs with efficiency of ca. 33% and rate constant of ca. 3.3 10 5 s -1 . This long-distance triplet energy transfer is proposed to proceed via a through-bond exchange mechanism.