Organic electroluminescent materials and devices

1. A compound comprising a first ligand L 1 having the Formula:

wherein ring A is a 6-membered heteroaryl and ring B is a phenyl;

wherein X 1 and X 2 is N, and the other X 1 and X 2 is C;

wherein X 3 and X 4 are C;

wherein R A and R B each independently represent mono, di, tri, or tetra substitution;

wherein at least one of R A and R B has a structure according to the following formula:

 wherein L is a direct bond or a linker selected from the group consisting of alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R 1 represents mono, di, tri, or tetra substitution, or no substitution;

wherein R 2 represents mono, di, tri, tetra, or penta substitution, or no substitution;

wherein M 2 is selected from the group consisting of Os, Ru, and Re;

wherein R 1 and R 2 are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein at least one R A has the structure of Formula II;

wherein when R A and R B is not Formula II, R A and R B are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any two adjacent substituents are optionally joined to form a ring, which can be further substituted;

wherein the ligand L 1 is coordinated to Ir;

wherein the Ir can be coordinated to other ligands; and

wherein the ligand L 1 is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand.

2. The compound of claim 1 , wherein at least one of R A and R B has a structure according to the following formula:

and

wherein R 5 and R 6 are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

3. The compound of claim 1 , wherein the ligand L 1 is

wherein R 3 and R 4 each independently represent mono, di, tri, or tetra substitution, or no substitution; and

wherein R 3 , R 4 , R 5 , and R 6 are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof.

4. The compound of claim 1 , wherein the compound is homoleptic.

5. The compound of claim 1 , wherein the compound is heteroleptic.

6. The compound of claim 1 , wherein the compound is neutral.

7. The compound of claim 1 , wherein the ligand L 1 is selected from the group consisting of:

8. The compound of claim 1 , wherein the compound has the formula of M(L 1 ) x (L 2 ) y (L 3 ) z ;

wherein L 2 is a second ligand, and L 3 is a third ligand, and L 2 and L 3 can be the same or different;

wherein x is 1, 2, or 3;

wherein y is 0, 1, or 2;

wherein z is 0, 1, or 2;

wherein x+y+z is the oxidation state of the metal M;

wherein the second ligand L 2 and the third ligand L 3 are independently selected from the group consisting of:

wherein R a , R b , R c , and R d may represent mono, di, tri, or tetra substitution, or no substitution;

wherein R a , R b , R c , and R d are independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein two adjacent substituents of R a , R b , R c , and R d are optionally joined to form a fused ring or form a multidentate ligand.

9. The compound of claim 8 , wherein the compound has the formula of Ir(L 1 )(L 2 ) 2 .

10. The compound of claim 1 , wherein the compound is selected from the group consisting of:

11. A device comprising one or more organic light emitting devices, at least one of the one or more organic light emitting devices comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, the organic layer comprising a compound comprising a first ligand L 1 of Formula I:

wherein ring A is a 6-membered heteroaryl and ring B is a phenyl;

wherein one of X 1 and X 2 is N, and the other X 1 and X 2 is C;

wherein X 3 and X 4 are C;

wherein R A and R B each independently represent mono, di, tri, or tetra substitution;

wherein at least one of R A and R B has a structure according to the following formula:

 wherein L is a direct bond or a linker selected from the group consisting of alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein R 1 represents mono, di, tri, or tetra substitution, or no substitution;

wherein R 2 represents mono, di, tri, tetra, or penta substitution, or no substitution;

wherein M 2 is selected from the group consisting of Os, Ru, and Re;

wherein R 1 and R 2 are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein at least one R A has the structure of Formula II;

wherein when R A and R B is not Formula II, R A and R B are each independently selected from the group consisting of hydrogen, deuterium, halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein any two adjacent substituents are optionally joined to form a ring, which can be further substituted;

wherein the ligand L 1 is coordinated to Ir;

wherein the Ir can be coordinated to other ligands; and

wherein the ligand L 1 is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand.

12. The device of claim 11 , wherein the device is selected from the group consisting of a consumer product, an electronic component module, an organic light-emitting device, and a lighting panel.

13. The device of claim 11 , wherein the organic layer is an emissive layer and the compound is an emissive dopant or a non-emissive dopant.

14. The device of claim 11 , wherein the organic layer further comprises a host comprising at least one chemical group selected from the group consisting of carbazole, triphenylene, aza-triphenylene, dibenzothiphene, dibenzofuran, dibenzoselenophene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

15. The device of claim 11 , wherein the organic layer further comprises a host selected from the group consisting of:

and combinations thereof.

16. A formulation comprising the compound of claim 1 .