| 主权项 |
1. A compound comprising a ligand LA of Formula I: wherein ring A is a 5-membered or 6-membered carbocyclic or heterocyclic ring; wherein R is fused to ring B and has a structure of Formula II: wherein the wave lines indicate bonds to ring B; wherein R1 represents mono, di, tri, or tetra substitution, or no substitution; wherein R2 represents mono or di substitution, or no substitution; wherein X1, X2, X3, and X4 are each independently carbon or nitrogen; wherein at least two adjacent of X1, X2, X3, and X4 are carbon and fuse to R; wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO2, CR′R″, SiR′R″, and GeR′R″; wherein R1, R2, R3, R4, R′, and R″ are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and wherein any two adjacent substituents are optionally joined to form into a ring; wherein at least one of R3 and R4 comprises a chemical group selected from the group consisting of alkyl, cycloalkyl, partially fluorinated alkyl, partially fluorinated cycloalkyl, and combinations thereof; wherein the ligand LA is coordinated to a metal M; wherein the ligand LA is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate, or hexadentate ligand; and wherein M is optionally coordinated to other ligands. |
