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 comprising a first ligand LA of Formula I
• wherein rings A and B are each independently a 5-membered or 6-membered carbocyclic or heterocyclic ring;
• wherein each Z1, Z2, Z3, and Z4 is independently C or N;
• wherein at least one of Z1 and Z2 is N, and at least one of Z3 and Z4 is N;
• wherein Z1 and Z2 are coordinated to Ir as represented by the dashed lines;
• wherein Z3 and Z4 are coordinated to M as represented by the dashed lines;
• wherein M is Pd or Pt;
• wherein Ir and M are each coordinated to at least one additional ligand;
• wherein RA and RB each represents mono to the maximum possible substitutions, or no substitution;
• wherein each RA and RB is independently hydrogen or a substituent selected from the group consisting of 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;
• and
• wherein any two substituents can be joined or fused to form a ring.

A consumer product comprising an organic light-emitting device 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 rings A and B are each independently a 5-membered or 6-membered carbocyclic or heterocyclic ring;
• wherein each Z1, Z2, Z3, and Z4 is independently C or N;
• wherein at least one of Z1 and Z2 is N, and at least one of Z3 and Z4 is N;
• wherein Z1 and Z2 are coordinated to Ir as represented by the dashed lines;
• wherein Z3 and Z4 are coordinated to M as represented by the dashed lines;
• wherein M is Pd or Pt;
• wherein Ir and M are each coordinated to at least one additional ligand;
• wherein RA and RB each represents mono to the maximum possible substitutions, or no substitution;
• wherein each RA and RB is independently hydrogen or a substituent selected from the group consisting of 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;
• and
• wherein any two substituents can be joined or fused to form a ring.