Organic electroluminescent materials and devices

1. A compound having a formula selected from the group consisting of:

wherein X is selected from the group consisting of O, S, and Se;

wherein X 1 to X 10 are each independently selected from the group consisting of carbon and nitrogen;

wherein at least one of X 1 to X 6 is nitrogen;

wherein R and R′ each independently represent from mono to the possible maximum number of substitutions, or no substitution;

wherein R and R′ 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, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of X 4 and X 5 is carbon, which is substituted by a D j selected from the group consisting of:

wherein any adjacent substitutions on the same ring are optionally joined or fused into a ring; and

wherein at least one of the following is true: (i) at least one of X 5 and X 6 is N, (ii) at least one of X 7 to X 10 is N, (iii) each of X 1 to X 4 is carbon;

provided that when adjacent substitutions on X 5 and X 6 in Formula I-1 and I-3 fuse into a six-member ring, this ring and the ring having X 7 to X 10 cannot be pyridine at the same time.

2. The compound of claim 1 , wherein at least one of X 5 and X 6 is nitrogen.

3. The compound of claim 1 , wherein the adjacent substitutions on X 5 and X 6 are not joined or fused into a ring.

4. The compound of claim 1 , wherein X 1 to X 4 are all carbon.

5. The compound of claim 1 , wherein at least one of X 1 to X 4 is nitrogen, and at least one of X 5 and X 6 is nitrogen.

6. The compound of claim 1 , wherein the compound has at least five aromatic rings fused together.

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

wherein Z 1 to Z 16 are each independently selected from the group consisting of carbon and nitrogen.

8. The compound of claim 1 , wherein the compound comprises a group selected from the group consisting of:

wherein the dotted lines represent a possible substitution.

9. The compound of claim 8 , wherein the compound is Compound x(Label) having the formula A i D j ,

wherein, x=144j+i−144, where i is an integer from 1, 3 to 8, 10, 12, 14, 16 to 37, 40, 42 to 51, 57 to 67, 69, 71, 73 to 92, 95, 98 to 105, 107 to 110, 113, 116, 117, 120 to 124, 126 to 137, 139 to 144, and j is an integer from 7 to 8, 10 to 29, 31 to 33, 36, 41 to 43, 45 to 49, 54 to 58, 61, 64 to 76, 79 to 244,

Label is the X in the corresponding A i , wherein the dotted line in each D j represents a bond to the corresponding A i .

10. The compound of claim 1 , wherein at least one of X 1 to X 4 is N.

11. The compound of claim 1 , wherein at least one of X 7 to X 10 is N.

12. The compound of claim 1 , wherein at least one pair of adjacent substituents of X 1 to X 10 are joined or fused together to form a ring.

13. The compound of claim 1 , wherein the compound has a structure of formula 1-2.

14. A first organic light emitting device comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having a formula selected from the group consisting of:

wherein X is selected from the group consisting of O, S, and Se;

wherein X 1 to X 10 are each independently selected from the group consisting of carbon and nitrogen;

wherein at least one of X 1 to X 6 is nitrogen;

wherein R and R′ each independently represent from mono to the possible maximum number of substitutions, or no substitution;

wherein R and R′ 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, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of X 4 and X 5 is carbon, which is substituted by a D j selected from the group consisting of:

wherein any adjacent substitutions on the same ring are optionally joined or fused into a ring; and

wherein at least one of the following is true: (i) at least one of X 5 and X 6 is N, (ii) at least one of X 7 to X 10 is N, (iii) each of X′ to X 4 is carbon;

provided that when adjacent substitutions on X 5 and X 6 in Formula I-1 and I-3 fuse into a six-member ring, this ring and the ring having X 7 to X 10 cannot be pyridine at the same time.

15. The first organic light emitting device of claim 14 , wherein the organic layer is an emissive layer and the compound is a host.

16. The first organic light emitting device of claim 14 , wherein the organic layer further comprises a phosphorescent emissive dopant; wherein the emissive dopant is a transition metal complex having at least one ligand or part of the ligand if the ligand is more than bidentate, selected from the group consisting of:

wherein each X 1 to X 13 are independently selected from the group consisting of carbon and nitrogen;

wherein Z is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO 2 , CR′R″, SiR′R″, and GeR′R″;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R a , R b , R c , and R d may represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein R′, R″, R a , R b , R c , and R d 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 acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

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

17. The first organic light emitting device of claim 14 , wherein the organic layer is a charge carrier blocking layer and the compound is a charge carrier blocking material in the organic layer, or the organic layer is a charge carrier transporting layer and the compound is a charge carrier transporting material in the organic layer.

18. The first organic light emitting device of claim 14 , 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.

19. The first organic light emitting device of claim 14 , wherein the organic layer is an emissive layer and the compound is an emitter.

20. The first organic light emitting device of claim 19 , wherein the first organic light emitting device emits a luminescent radiation at room temperature when a voltage is applied across the first organic light emitting device, and wherein the luminescent radiation comprises a delayed fluorescence process.

21. The first organic light emitting device of claim 19 , wherein the emissive layer further comprises a first phosphorescent emitting material.

22. A formulation comprising a compound having a formula selected from the group consisting of:

wherein X is selected from the group consisting of O, S, and Se;

wherein X 1 to X 10 are each independently selected from the group consisting of carbon and nitrogen;

wherein at least one of X 1 to X 6 is nitrogen;

wherein R and R′ each independently represent from mono to the possible maximum number of substitutions, or no substitution;

wherein R and R′ 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, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;

wherein at least one of X 4 and X 5 is carbon, which is substituted by a D j selected from the group consisting of:

wherein any adjacent substitutions on the same ring are optionally joined or fused into a ring; and

wherein at least one of the following is true: (i) at least one of X 5 and X 6 is N, (ii) at least one of X 7 to X 10 is N, (iii) each of X 1 to X 4 is carbon;

provided that when adjacent substitutions on X 5 and X 6 in Formula I-1 and I-3 fuse into a six-member ring, this ring and the ring having X 7 to X 10 cannot be pyridine at the same time.