Theoretical and experimental study of dynamic triplet-triplet annihilation in an organic one-dimensional motion system

Abstract

Pair-density-matrix theory has been adapted to the triplet-pair exciton annihilation under microwave excitation by including the dimensionality of exciton motion and applied to the fluorescence detected magnetic-resonance spectrum observed for a one-dimensional molecular crystal. This theory gives a satisfactory fit of the observed effects on a 1,4 dibromonaphtalene crystal and leads to the determination of the singlet annihilation rate constant $\ensuremath{\lambda}$ and the triplet exciton pair lifetime ${\ensuremath{\beta}}^{\ensuremath{-}1}$.