Efficient helical columnar emitters of chiral homoleptic Pt() metallomesogens for circularly polarized electroluminescence

Chiral organometallic Pt( ii ) complexes have been demonstrated to be excellent circularly polarized luminescence (CPL) materials due to their rich phosphorescence and strong self-assembly characteristics. However, it remains a formidable task to simultaneously achieve high luminance ( L ) and electroluminescence dissymmetry factor ( g EL ) values for circularly polarized electroluminescence (CP-EL) devices of Pt( ii ) complex-based emitters. In this study, we carry out a straightforward and efficient protocol to construct highly CPL-active helical columnar ( ) emitters by using chiral homoleptic triazolatoplatinum( ii ) metallomesogens ( R / S -HPt ). The peripheral flexible groups can not only improve solubility but also favor the induction of chirality and liquid crystal behavior. The resultant complexes R / S -HPt can self-assemble into the mesophase over a broad temperature range (6-358 °C) and exhibit excellent phosphorescence ( Φ : up to 86%), resulting in intense CPL signals after thermal annealing ( λ em = 615 nm and | g em | = 0.051). Using emitting layers (EML) based on R / S -HPt in solution-processed CP-EL devices, L max and | g EL | of CP-EL can reach up to 11 379 cd m −2 and 0.014, respectively. With comprehensive consideration of L max and g EL , this investigation shows the excellent performances among Pt( ii ) complex-based CP-EL devices. Helical columnar ( ) emitters of homoleptic platinum( ii ) metallomesogens ( R / S -HPt ) are constructed via chiral self-assembly, and can be applied to realize efficient solution-processed circularly polarized electroluminescence (CP-EL) devices.