Organic electroluminescent materials and devices

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 a first ligand LA of
• wherein ring A is a 5- or 6-membered carbocyclic or heterocyclic ring;
• wherein X is NR, O, or S;
• wherein RA and RB each represents mono to a maximum possible number of substitutions, or no substitution;
• wherein RA and RB are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof,
• wherein R is selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof;
• wherein any adjacent substitutions in RA and RB can be joined or fused into a ring;
• wherein Z1 is an anionic coordinating atom selected from the group consisting of C and N;
• wherein the ligand LA is coordinated to Ir or Pt;
• wherein LA is a bidentate ligand when it is coordinated to Ir;
• wherein Ir or Pt can be coordinated to other ligands.

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
• wherein ring A is a 5- or 6-membered carbocyclic or heterocyclic ring;
• wherein X is NR, O, or S;
• wherein RA and RB each represents mono to a maximum possible number of substitutions, or no substitution;
• wherein RA and RB are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof,
• wherein R is selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof;
• wherein any adjacent substitutions in R, RA, and RB can be joined or fused into a ring;
• wherein Z1 is an anionic coordinating atom selected from the group consisting of C and N;
• wherein the ligand LA is coordinated to Ir or Pt;
• wherein LA is a bidentate ligand when it is coordinated to Ir;
• wherein Ir or Pt can be coordinated to other ligands.