Intermolecular interactions in molecular crystals and their effect on thermally activated delayed fluorescence of helicene-based emitters

Anastasia Klimash,Piotr Pander,Fernando B Dias,Simon J Coles,Wim T Klooster,Peter J Skabara,Przemyslaw Data

doi:10.1039/c8tc03390k

Abstract

In crystals of donor–acceptor helicene molecules, thermally activated delayed fluorescence (TADF) is strongly enhanced by the presence of occluded hexane molecules.

Highlights

Despite the increasing amount of thermally activated delayed fluorescence (TADF) materials reported to date, very few studies are focused on investigating TADF behaviour in pure solid state, i.e. without dispersing the emitter in a host
Despite the increasing amount of TADF materials reported to date, very few studies are focused on investigating TADF behaviour in pure solid state, i.e. without dispersing the emitter in a host
The preparation of helical acceptor cores is the limiting step for the scale-up of the materials as highly diluted solutions were used in order to avoid side products of [2+2] cycloaddition

Summary

Introduction

Despite the increasing amount of TADF materials reported to date, very few studies are focused on investigating TADF behaviour in pure solid state, i.e. without dispersing the emitter in a host. Both molecules show delayed CT fluorescence in MCH solution (Fig. S7.1, ESI†) attributed to the TADF mechanism. Photoluminescence decay of H1-PXZ and H2-PXZ in solution at room temperature shows a typical TADF emission behaviour with two exponential regimes depicting prompt and delayed fluorescence, respectively.

Results

Conclusion