Efficient Synthesis of Carbazolyl- and Thienyl-Substitutedfl-Diketonates and Properties of Their Red- andGreen-Light-Emitting Ir(III) Complexes

摘要

The efficient synthesis of novel β-diketonates equipped with functional carbazolyl moieties and theirsubsequent transformations in 5-hexyl-thienyl substituted carbazole derivatives is presented by utilizingan effective Stille cross-coupling reaction. The introduced β-diketonates served as ancillary ligands fornovel heteroleptic red- and green-emitting Ir(III) complexes, when combined with 2-(naphthalen- 1 -yl)pyridine and 2-phenylpyridine as cyclometalating ligands. These novel Ir(III) complexes revealed color-tunability and a very good thermal stability until at least 207 °C. In polystyrene blends, the heterolepticIr(III) complexes revealed remarkable quantum yields up to 36% and suitably short phosphorescencelifetimes ranging from 1 to 4 μs. In the case of the orange-red Ir(III) emitter, equipped with 2-(naphthalen-1 -yl)pyridine cyclometallating ligands, a luminous efficiency as high as 7.7 cd/A at 7.4 V was achieved.All fabricated diodes exhibited in addition favorable color stability.