Organic electroluminescent materials and devices comprising imidazole-containing metal complexes

An organic light emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an organic layer, disposed between the anode and the cathode, comprising a compound comprising a first ligand LA of Formula I:
• wherein A1 and A2 are each independently C or Si;
• wherein each RA independently represents mono to the maximum allowable substitution, or no substitution;
• wherein each R, R1, R2, R3, R4 and RA is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof,
• wherein LA is complexed to a metal M;
• wherein M is optionally coordinated to one or more other ligands;
• wherein the ligand LA is optionally linked with the one or more other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand;
• and
• wherein any two adjacent substituents are optionally joined or fused together to form a ring.

A consumer product comprising an organic light-emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an organic layer, disposed between the anode and the cathode, comprising a compound comprising a first ligand LA of Formula I:
• wherein A1 and A2 are each independently C or Si;
• wherein each RA independently represents mono to the maximum allowable substitution, or no substitution;
• wherein each R, R1, R2, R3, R4 and RA is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof,
• wherein LA is complexed to a metal M;
• wherein M is optionally coordinated to one or more other ligands;
• wherein the ligand LA is optionally linked with the one or more other ligands to form a tridentate, tetradentate, pentadentate, or hexadentate ligand;
• and
• wherein any two adjacent substituents are optionally joined or fused together to form a ring.