Yellowish-orange and red emitting quinoline-based iridium(III) complexes: Synthesis, thermal, optical and electrochemical properties and OLED application

Abstract Two novel heteroleptic iridium(III) acetylacetonate (acac) complexes K3a and K3b were synthesised from cyclometallating ligands of 2-(4′-formylphenyl)quinoline 11a and 2-(5′-formylphenyl)quinoline 11b. Complexes K3a and K3b were fully characterised by NMR spectroscopy, mass spectrometry and FT-IR. Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) indicate that both complexes were amorphous solids, stable up to 303 °C and 313 °C, respectively. Complexes K3a and K3b showed strong, high-energy absorption bands (