Organic electroluminescent materials and devices

1. A compound having the structure of Formula 1:

wherein

R a is selected from biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, or fluorenyl;

n is the number of R b , n is selected from 1, 2, 3 or 4; when n≥2, the structures of the R b may be the same or different; each of R b is independently selected from the group consisting of hydrogen, deuterium, phenyl, biphenyl and terphenyl;

R c , R d and R e are each independently selected from the group consisting of hydrogen, deuterium, halogen, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and combinations thereof;

and, wherein R 1 has the structure of Formula 2:

wherein L is selected from a single bond, or a substituted or unsubstituted arylene having 6 to 12 carbon atoms;

wherein R 2 and R 3 are each independently selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms;

when R 2 and R 3 are selected from the substituted group in the group, the substitution in the substituted group is selected from deuterium, halogen, an unsubstituted alkyl group having 1 to 20 carbon atoms, an unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, an unsubstituted heteroalkyl group having 1 to 20 carbon atoms, an unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an unsubstituted aryl group having 6 to 30 carbon atoms, and combinations thereof;

wherein at least one of R 2 and R 3 is biphenyl or terphenyl.

2. The compound of claim 1 , wherein at least one of R 2 and R 3 is biphenyl or terphenyl, and the other one is phenyl, biphenyl or terphenyl.

3. The compound of claim 1 , wherein L is a single bond.

4. The compound of claim 2 , wherein L is a single bond.

5. The compound of claim 1 , wherein R b is hydrogen.

6. The compound of claim 1 , wherein R c , R d and R e are hydrogen.

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

8. An electroluminescent device, which comprises

an anode,

a cathode,

and an organic layer disposed between the anode and the cathode, wherein the organic layer comprising the compound of claim 1 .

9. The device of claim 8 , wherein the organic layer is a hole blocking layer, and the compound is a hole blocking material.

10. The device of claim 8 , wherein the organic layer is a light emitting layer and the compound is a host material.

11. The device of claim 10 , wherein the organic layer further comprises phosphorescent material.

12. The device of claim 11 , wherein the phosphorescent material is a metal complex, wherein the metal complex comprises at least one ligand, and the ligand comprises any one of the following structures:

wherein

R x , R y , and R z , may represent mono substitution, multiple substitutions or no substitution;

R x , R y , and R z , are each independently selected from the group consisting of hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a nitrile group, an isonitrile group, a thiol group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof;

X b is selected from the group consisting of O, S, Se, NR N1 , and CR C1 R C2 ;

R N1 , R C1 and R C2 are each independently selected from the group consisting of hydrogen, deuterium, halogen, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 0 to 20 carbon atoms, an acyl group, a carbonyl group, a carboxylic acid group, an ester group, a nitrile group, an isonitrile group, a thioalkyl group, a sulfinyl group, a sulfonyl group, a phosphino group, and combinations thereof.

13. The device of claim 10 , wherein the organic layer further comprises at least one host material different from the compound having Formula 1.

14. A compound formulation comprising the compound of claim 1 .