Kinetic Studies on Intramolecular Excimer Formation in Dinaphthylalkanes

Article abstract of DOI:10.1246/bcsj.54.35

Various dinaphthylalkanes in which two naphthyl groups are separated by three carbon atoms were prepared, and intramolecular excimer formation was investigated.All rate constants in Foerster's kinetics were determined by the steady state and time-resolved fluorescence measurements.A large difference in the association rate constant was observed with variation of molecular structure.The results suggest that intramolecular excimer formation is directly controlled by the rotational relaxation processes of the molecules from their neighboring conformations to the excimer conformation.A large formation rate (7.9 * 10⁸ s^-1 at 25 deg C) was observed for meso-2,4-dinaphthylpentane, the rate for the racemo isomer being found to be one tenth of that for the meso isomer.This indicates that the isotactic sequence in vinyl aromatic polymers plays an important role in the intramolecular excimer formation.