Effect of the Imidazole π-Extension on TADF Emitters in Electrochemiluminescence.

Already known molecules which exhibit good electrochemiluminescence (ECL) efficiencies and high photoluminescence quantum yields (PLQY) have been structurally modified in order to increase their performance. The followed strategy is to stiffen the structures to limit the rotational and vibrational freedom degrees and favour radiative decay processes once excited. Molecules under investigation consist of donor-acceptor systems in which the acceptor fraction is a benzonitrile with an imidazole in para position, while the donor fraction consists of four diphenylamine (NPh) or 3,6-di(tert-butyl)-9H-carbazole (Cz) groups in the remaining positions on the central benzene ring.