Helically Chiral Tetradentate Pt(II) Complexes for Simultaneous Deep-Blue Electroluminescence and Circularly Polarized Luminescence via Diastereoselective Synthesis.

Abstract

Circularly polarized organic light-emitting diodes (CP-OLEDs) have attracted great attention because of their promising applications in 3D displays. However, developing high-performance CP-OLEDs typically face the challenge of integrating large-scale availability of emitters, device efficiency, color purity, and brightness, especially in the deep-blue spectral region. Herein, we developed a novel strategy to successfully realize the diastereoselective and gram-scale synthesis of helically chiral tetradentate Pt(II) complexes with high configurational stabilities through a central chirality adaptively induced helical chirality (CAIH) approach. The bulky central chiral moiety facilitates the suppression of intermolecular interactions and increases the color purity and molecular rigidity. R,M-PtCam2 showed a quantum efficiency of 99% and high color purity, with a full-width at half-maximum (FWHM) of 19.8 nm. R,M-PtCam2/P-PtCam2-based deep-blue OLEDs successfully displayed obvious and mirror-image CP electroluminescence signals. R,M-PtCam2 CP-OLED exhibited a high color purity (FWHM = 24 nm) and a high maximum brightness of up to 51592 cd/m2; moreover, it also achieved a maximum external quantum efficiency (EQE) of 33.2%, along with a record-high EQE of 30.9% at 1000 cd/m2 for all reported deep-blue CP-OLEDs with CIEy < 0.20. This study provides a molecular design strategy to prepare robust helically chiral Pt(II) emitters for high-performance deep-blue phosphorescent CP-OLEDs.