Novel aggregation-induced emission and thermally activated delayed fluorescence materials based on thianthrene-9,9′,10,10′-tetraoxide derivatives?

RSC Advances Pub Date: 2016-02-19 DOI: 10.1039/C6RA03281H

Abstract

Two novel luminescent molecules based on thianthrene-9,9′,10,10′-tetraoxide derivatives, named tCzDSO2 and 3tCzDSO2, have been synthesized and characterized. The compound tCzDSO2 emits intense aggregation-induced emission (AIE) with a high photoluminescence quantum yields (ΦF) of 0.92 at room temperature in the solid state. Simultaneously, by increasing the proportion of carbazole units, 3tCzDSO2 exhibits both AIE and thermally activated delayed fluorescence (TADF) in the solid state with ΦF of 0.19 in air and 0.41 in N2 atmosphere. The two compounds also display a bathochromic effect due to their intramolecular charge transfer (ICT) attribute. The time-dependent DFT predicted the singlet and triplet splitting (ΔEST) values of tCzDSO2 and 3tCzDSO2 to be 0.29 eV and 0.06 eV, respectively. The ΔEST of 3tCzDSO2 is small enough to allow efficient reverse intersystem crossing (RISC), leading to the TADF property at room temperature. As a result, the molecular design provides a simple and effective approach to integrate the features of AIE and TADF into one compound.

Graphical abstract: Novel aggregation-induced emission and thermally activated delayed fluorescence materials based on thianthrene-9,9′,10,10′-tetraoxide derivatives
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