Delayed Blue Fluorescence via Upper-Triplet State Crossing from C-C Bonded Donor-Acceptor Charge Transfer Molecules with Azatriangulene Cores.

ABSTRACT: We report the synthesis and structural and photophysical characterization of two series of molecules with functionalized azatriangulene electron donor cores and three pendant electron acceptor units. The presented donor and acceptor units are joined by C-C bonds, instead of the usual C-heteroatom bonds often found in thermally activated delayed fluorescence (TADF) emitters. The effects of the donor-acceptor strength and donor-acceptor dihedral angle on the emission properties are assessed. The data establish that the singlet-triplet energy gap is >0.3 eV and that delayed emission is present in only specific host matrices, irrespective of host polarity. Specific host behavior is atypical of many TADF materials, and we suggest the delayed emission in this work does not occur by a conventiona

SUBMITTER: Ward JS 

PROVIDER: S-EPMC7011764 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature