Electronic coupling responsible for energy transfer in columnar liquid crystals

Electronic coupling is the driving force for energy transfer in molecular materials and consists of several components. We determine the strength of dipolar/multipolar coupling and coupling due to orbital overlap for excitation transport in triphenylene columnar liquid crystals. We use time-resolved fluorescence spectroscopy and computer simulations. The fit of the experimental and simulated fluorescence decays reveals that the transfer process is dominated by short range interactions (multipolar and orbital overlap) but the contribution of long range dipolar interactions cannot be neglected.