Electronic coupling responsible for energy transfer in columnar liquid crystals

Electronic coupling is the driving force for energy transfer in molecular m aterials and consists of several components. We determine the strength of d ipolar/multipolar coupling and coupling due to orbital overlap for excitati on transport in triphenylene columnar liquid crystals. We use time-resolved fluorescence spectroscopy and computer simulations, The fit of the experim ental and simulated fluorescence decays reveals that the transfer process i s dominated by short range interactions (multipolar and orbital overlap) bu t the contribution of long range dipolar interactions cannot be neglected. (C) 1999 Elsevier Science B.V. All rights reserved.