Conjugated Asymmetric Donor‐Substituted 1,3,5‐Triazines: New Host Materials for Blue Phosphorescent Organic Light‐Emitting Diodes

Abstract Conjugated asymmetric donor‐substituted 1,3,5‐triazines (ADTs) have been synthesized by nucleophilic substitution of organolithium catalyzed by [Pd(PPh 3 ) 4 ]. Theoretical and experimental investigations show that ADTs possess high solubility and thermostability, high fluorescent quantum yield (35 %), low HOMO (−6.0 eV) and LUMO (−2.8 eV), and high triplet energy ( E T , 3.0 eV) according to the different substitution pattern of triazine. The application as host materials for blue PHOLEDs yielded a maximum current efficiency of 20.9 cd A −1 , a maximum external quantum efficiency of 9.8 %, and a brightness of 9671 cd m −2 at 5.4 V, making ADTs good candidates for optoelectronic devices.