Organic electroluminescent materials and devices

1. A compound comprising a first ligand L A selected from the group consisting of:

or the compound has one of the following formulas:

wherein ring A is a 5- or 6-membered carbocyclic or heterocyclic ring;

wherein Z 1 to Z 5 are each independently carbon, nitrogen, oxygen, or phosphorus;

wherein X 1 to X 8 , Z 7 and Z 8 are each independently carbon or nitrogen;

wherein Z 6 is selected from the group consisting of carbon, nitrogen, oxygen, sulfur, phosphorus, and boron;

wherein R 1′ , R 2′ , R 1 , R 2 , R B , R C , and R A each independently represents none to a maximum possible number of substitutions;

wherein each R 1′ , R 2′ , R 1 , R 2 , and R A is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any two substitutions in R 1′ , R 2′ , R 1 , R 2 , and R A are optionally joined or fused into a ring;

wherein the ligand L A is coordinated to a metal M;

wherein if L A has a formula according to Formula II or Formula III, it is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate, or hexadentate ligand;

wherein for Formula II and Formula III, M is optionally coordinated to other ligands;

wherein m1, m2 and m3 are each independently an integer of 0 or 1;

when m2 is 0, each m1 and m3 is 1; when m2 is 1, each m1 and m3 are each independently 0 or 1;

wherein at least one of m1 and m3 is not 0;

wherein when m1 is 0, L 1 is not present;

when m2 is 0, L 2 is not present;

when m3 is 0, L 3 is not present;

wherein L 1 , L 2 , and L 3 are each independently selected from the group consisting of a direct bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof;

wherein R B , R C , R, and R′ are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, and combinations thereof;

wherein any two substitutions are optionally joined or fused into a ring;

wherein Q 1 and Q 2 are each independently a direct bond or oxygen;

wherein when any of Z 7 and Z 8 is nitrogen, the Q 1 and Q 2 attached thereto is a direct bond; and

wherein M is Pt or Pd.

2. The compound of claim 1 , wherein each R 1 , R 2 , and R A is independently selected from hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, and combinations thereof.

3. The compound of claim 1 , wherein the compound has one of the following formulas:

4. The compound of claim 3 , wherein each Q 1 and Q 2 is a direct bond.

5. The compound of claim 3 , wherein one of Q 1 and Q 2 is oxygen, and the other one of Q 1 and Q 2 is direct bond.

6. The compound of claim 3 , wherein one of Z 7 and Z 8 is carbon, and the other one of Z 7 and Z 8 is nitrogen.

7. A compound comprising a first ligand L A selected from the group consisting of:

or the compound has one of the following formulas:

wherein ring A is a 5- or 6-membered carbocyclic or heterocyclic ring;

wherein Z 1 to Z 5 are each independently carbon, nitrogen, oxygen, or phosphorus;

wherein X 1 to X 8 , Z 7 and Z 8 are each independently carbon or nitrogen;

wherein Z 6 is selected from the group consisting of carbon, nitrogen, oxygen, sulfur, phosphorus, and boron;

wherein R 1′ , R 2′ , R 1 , R 2 , R B , R C , and R A each independently represents none to a maximum possible number of substitutions;

wherein each R 1′ , R 2′ , R 1 , R 2 , and R A is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any two substitutions in R 1′ , R 2′ , R 1 , R 2 , and R A are optionally joined or fused into a ring;

wherein the ligand L A is coordinated to a metal M;

wherein if L A has a formula according to Formula II or Formula III, it is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate, or hexadentate ligand;

wherein for Formula II and Formula III, M is optionally coordinated to other ligands;

wherein m1, m2 and m3 are each independently an integer of 0 or 1;

when m2 is 0, each m1 and m3 is 1; when m2 is 1, each m1 and m3 are each independently 0 or 1;

wherein at least one of m1 and m3 is not 0;

wherein when m1 is 0, L 1 is not present;

when m2 is 0, L 2 is not present;

when m3 is 0, L 3 is not present;

wherein L 1 , L 2 , and L 3 are each independently selected from the group consisting of a direct bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof;

wherein R B , R C , R, and R′ are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, and combinations thereof;

wherein any two substitutions are optionally joined or fused into a ring;

wherein Q 1 and Q 2 are each independently a direct bond or oxygen;

wherein when any of Z 7 and Z 8 is nitrogen, the Q 1 and Q 2 attached thereto is a direct bond;

wherein M is Pt or Pd; and

wherein one of the following conditions is true:

one of Z 7 and Z 8 is a neutral carbene carbon, the other one of Z 7 and Z 8 is anionic carbon; or

each L 1 , L 2 , and L 3 is not a direct bond when they are present.

8. The compound of claim 3 , wherein L 2 is a direct bond.

9. The compound of claim 3 , wherein the rings of A, B, and C are each independently selected from the group consisting of phenyl, pyridine, imidazole, and imidazole derived carbene.

10. The compound of claim 3 , wherein the compound has at least one Pt-carbene bond.

11. The compound of claim 3 , wherein the compound is selected from the group consisting of:

wherein R D to R G have same definition as R A to R C ;

wherein X 9 to X 25 have same definition as X 1 to X 8 ; and

wherein R 1′ , R 2′ , R 3′ , and R 4′ have the same definition as R 1 and R 2 .

12. The compound of claim 1 , wherein the compound is selected from groups consisting of:

13. 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 L A selected from the group consisting of:

or the compound has one of the following formulas:

wherein ring A is a 5- or 6-membered carbocyclic or heterocyclic ring;

wherein Z 1 to Z 5 are each independently carbon, nitrogen, oxygen, or phosphorus;

wherein X 1 to X 8 , Z 7 and Z 8 are each independently carbon or nitrogen;

wherein Z 6 is selected from the group consisting of carbon, nitrogen, oxygen, sulfur, phosphorus, and boron;

wherein R 1′ , R 2′ , R 1 , R 2 , R B , R C , and R A each independently represents none to a maximum possible number of substitutions;

wherein each R 1′ , R 2′ , R 1 , R 2 , and R A is independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any two substitutions in R 1′ , R 2′ , R 1 , R 2 , and R A are optionally joined or fused into a ring;

wherein the ligand L A is coordinated to a metal M;

wherein if L A has a formula according to Formula II or Formula III, it is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate, or hexadentate ligand;

wherein for Formula II and Formula III, [WK1] M is optionally coordinated to other ligands;

wherein m1, m2 and m3 are each independently an integer of 0 or 1;

when m2 is 0, each m1 and m3 is 1; when m2 is 1, each m1 and m3 are each independently 0 or 1;

wherein at least one of m1 and m3 is not 0; [WK2]

wherein when m1 is 0, L 1 is not present;

when m2 is 0, L 2 is not present;

when m3 is 0, L 3 is not present;

wherein L 1 , L 2 , and L 3 are each independently selected from the group consisting of a direct bond, BR, NR, PR, O, S, Se, C═O, S═O, SO 2 , CRR′, SiRR′, GeRR′, alkyl, cycloalkyl, and combinations thereof;

wherein R B , R C , R, and R′ are each independently selected from the group consisting of hydrogen, deuterium, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, and combinations thereof;

wherein any two substitutions are optionally joined or fused into a ring;

wherein Q 1 and Q 2 are each independently a direct bond or oxygen;

wherein when any of Z 7 and Z 8 is nitrogen, the Q 1 and Q 2 attached thereto is a direct bond; and

wherein M is Pt or Pd.

14. The OLED of claim 13 , wherein the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.

15. The OLED of claim 13 , wherein the organic layer further comprises a host, wherein host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

16. The OLED of claim 13 , wherein the organic layer further comprises a host, wherein the host is selected from the group consisting of:

and combinations thereof.

17. A consumer product comprising the OLED of claim 13 .

18. The consumer product of claim 17 , wherein the consumer product is selected from the group consisting of a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display that is less than 2 inches diagonal, a 3-D display, a virtual reality or augmented reality display, a vehicle, a video walls comprising multiple displays tiled together, a theater or stadium screen, and a sign.

19. A formulation comprising the compound of claim 1 .