Tetradentate Pt(II) complexes based on xylenylamino linked dual pyrazolate chelates for organic light emitting diodes

Abstract In this work, we report the syntheses of three Pt(II) emitters, namely, Pt4N1 , Pt4N2 , and Pt4N3 , to which their tetradentate chelates were assembled by linking two pyrazolate chelates with a single xylenylamino entity. Functionalization of Pt4N1 was achieved upon the addition of electronegative CF 3 substituent on pyridinyl groups and switching to more electron‐deficient pyrazinyl groups in giving Pt4N2 and Pt4N3 , respectively. The vertically arranged xylenylamino entity has effectively suppressed the inter‐molecular π‐π stacking and Pt⋅⋅⋅Pt interaction, as shown by the single crystal X‐ray structural analyses. Upon fabrication of OLED devices, Pt4N2 and Pt4N3 based devices delivered efficient cyan and green emission, with an EQE max of 15.2 % and 11.2 %, respectively, affirming the successfulness of the tetradentate chelating strategy.