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, wherein the organic layer comprises a compound comprising a first ligand LA of Formula I:
• wherein
• each of X1, X2, X3, X4, X5, X6, X7, X8, and X9 is independently C or N;
• one of Z1 and Z2 is C and the other is N;
• K1 and K2 are each independently selected from the group consisting of a direct bond, O, and S;
• at least one of K1 and K2 is a direct bond;
• RA and RC each independently represents mono, up to maximum allowed substitutions, or no substitution;
• RB represents mono, or up to maximum allowed substitutions;
• each of R1, R2, RA, RB, and RC is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, selenyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;
• each of X1, X2, X3, X4, X5, X6, X7, X8, and X9 that has an RA, RB, or RC attached thereto is C;
• at least one of R1 and R2 is selected from the group consisting of alkyl, heteroalkyl, cycloalkyl, and heterocycloalkyl;
• R3 is selected from the group consisting of alkyl, heteroalkyl, cycloalkyl, and heterocycloalkyl;
• at least one of the following is true:
• (i) at least one RB comprises a 5-membered or 6-membered heterocycle,
• (ii) two adjacent RB are joined to form a fused 5-membered or 6-membered carbocyclic or heterocyclic ring, which can be further substituted, or
• (iii) RB comprises a carbocyclic or heterocyclic ring substituted with at least one electron withdrawing group;
• LA is coordinated to a metal M selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag, and Au;
• LA may be joined with other ligand to comprise a tridentate, tetradentate, pentadentate, and hexadentate ligand;
• and
• any two of R1, R2, R3, RA, RB, and RC can be joined 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, wherein the organic layer comprises a compound comprising a first ligand LA of Formula I:
• wherein:
• each of X1, X2, X3, X4, X5, X6, X7, X8, and X9 is independently C or N;
• one of Z1 and Z2 is C and the other is N;
• K1 and K2 are each independently selected from the group consisting of a direct bond, O, and S;
• at least one of K1 and K2 is a direct bond;
• RA and RC each independently represents mono, up to maximum allowed substitutions, or no substitution;
• RB represents mono, or up to maximum allowed substitutions;
• each of R1, R2, RA, RB, and RC is independently a hydrogen or a substituent selected from the group consisting of deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, heterocycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, germyl, boryl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, selenyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;
• each of X1, X2, X3, X4, X5, X6, X7, X8, and X9 that has an RA, RB, or RC attached thereto is C;
• at least one of R1 and R2 is selected from the group consisting of alkyl, heteroalkyl, cycloalkyl, and heterocycloalkyl;
• R3 is selected from the group consisting of alkyl, heteroalkyl, cycloalkyl, and heterocycloalkyl;
• at least one of the following is true:
• (i) at least one RB comprises a 5-membered or 6-membered heterocycle,
• (ii) two adjacent RB are joined to form a fused 5-membered or 6-membered carbocyclic or heterocyclic ring, which can be further substituted, or
• (iii) RB comprises a carbocyclic or heterocyclic ring substituted with at least one electron withdrawing group;
• LA is coordinated to a metal M selected from the group consisting of Os, Ir, Pd, Pt, Cu, Ag, and Au;
• LA may be joined with other ligand to comprise a tridentate, tetradentate, pentadentate, and hexadentate ligand;
• and
• any two of R1, R2, R3, RA, RB, and RC can be joined to form a ring.