| 主权项 |
1. A compound comprising a ligand LA of Formula I: wherein R has the following structure and is fused to ring A: wherein each Z1 to Z8 is nitrogen or carbon; wherein the wave lines indicate the bonds to two of the adjacent Z1 to Z4 of ring A; wherein when two of the adjacent Z1 to Z4 are used to fuse to R, those two of the adjacent Z1 to Z4 are carbon; wherein R1 and R4 each independently represent mono, di, tri, or tetra substitutions, or no substitution; wherein R2 and R3 each independently represent mono, or di substitutions, or no substitution; wherein X is O or S; wherein R1, R2, R3, R4, R5, and R6 are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein any two adjacent substituents are optionally joined to form a ring, which can be further substituted; wherein the ligand LA is coordinated to a metal M; and wherein the ligand LA is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand. |
