| Popis: |
Chiral Iridium complexes are very important for the preparation of circularly polarized light emitting diodes (CP-OLEDs). Three novel Iridium(III) complexes, Ir(dnfppy)2(Cl/pyrrole), Ir(dfppy)2(dpp) and Ir(tfmqz)2(sdpp) have been synthesized and characterized, respectively. These Iridium(III) complexes emitted deep-blue, blue and red photoluminescence with high quantum yields, for ((Ir(dnfppy)2(Cl/Pyrrole): λmax=447 nm, F=62.4%; Ir(dfppy)2(dpp): λmax=467 nm, F= 25%; Ir(tfmqz)2(sdpp): λmax=609 nm, F=73.7%). Compared with Ir(dnfppy)2(Cl/pyrrole), HOMO energy level of Ir(dfppy)2(dpp) and Ir(tfmqz)2(sdpp) was calculated to be −5.71/-5.73 eV, and LUMO energy level increased to be -2.75/-3.36 eV, respectively. CD spectra of two pairs of the enantiomers for Ir(dfppy)2(dpp) or Ir(tfmqz)2(sdpp) displayed symmetry with opposite polarization between 300 and 600 nm. The maximum external quantum efficiency (EQEmax) of OLEDs based on Ir(tfmpqz)2(sddp) was 13.8%, showing a relatively low efficiency roll-off with the EQE of 10.7% at 5000 cd/m2. |
