Deep-Blue Thermally Activated Delayed Fluorescence from a CF3-substituted Carbene-Metal-Amide Complex

Abstract

The gold-based carbene-metal-amide (CMA) complex BICAuBGCF3 with a 2-(trifluoromethyl)-benzoguanidine amide (L) have been prepared in good yields and characterized. The CF3-substituted amide donor ligand resulted in 0.27 eV stabilization of the highest occupied molecular orbital (HOMO) and wide energy gap of 2.97 eV. In fluid media complex experience a dynamic behavior between two forms which reduces the blue luminescence quantum yield down to 43%. In solid state complex shows bright deep-blue thermally activated delayed fluorescence at 432 nm with 60% luminescence quantum yield thanks to small singlet triplet energy gap (ΔEST) down to 54 meV. The radiative rates (kr) are up to 1.4×106 s–1 in amorphous polystyrene media indicating BICAuBGCF3 complex as a promising material for optoelectronic applications.