Synthesis, Characterization, and Physical Properties of Pyrene‐Naphthalimide Derivatives as Emissive Materials for Electroluminescent Devices

Abstract

AbstractA series of axially linked pyrene‐naphthalimide fluorophores (N2Py, N4Py, and BNPy) bearing a different number of 1,8‐naphthalimide units substituted on pyrene and bis‐pyrene cores were designed and synthesized using palladium‐catalyzed cross‐coupling reactions in a stepwise synthetic manner. These molecules were chemically characterized, and their photoelectric properties were explored by spectroscopy, electrochemical and theoretical studies. They exhibited push‐pull characteristics with intense fluorescence in solutions, strong solvatochromic behaviors, good thermal and electrochemical stabilities. N2Py, N4Py, and BNPy were successfully applied as emitters in solution‐processed OLED devices, which resulted in blue‐green emissions with promising device performance. Particularly, the BNPy‐based device achieved the best EL results with a maximum brightness of 3389 cd m−2, a maximum EQE of 3.98 %, a maximum LE of 3.22 cd A−1, and a low turn‐on voltage of 3.2 V.