Organic electroluminescent materials and devices

1. A compound of Formula I;

wherein each of Z 1 -Z 16 is independently C or N;

wherein each of R A , R B , R C , and R D represents mono to the maximum allowable substitution, or no substitution;

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

wherein at least one of Z 1 -Z 16 is N;

wherein at least one of R A , R B , R C , and R D is present and comprises a chemical group selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, triphenylene, azatriphenylene, azatetraphenylene, tetraphenylene, azacarbazole, azadibenzofuran, azadibenzothiophene, azadibenzoselenophene, azafluorene, benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, benzo[d]benzo[4,5]imidazo[2,1-b]oxazole, and benzo[d]benzo[4,5]imidazo[2,1-b]thiazole.

2. The compound of claim 1 , wherein at least one of Z 1 -Z 16 is N.

3. The compound of claim 1 , wherein exactly one of Z 1 -Z 16 is N.

4. The compound of claim 1 , wherein exactly two of Z 1 -Z 16 are N.

5. The compound of claim 1 , wherein exactly four of Z 1 -Z 16 are N.

6. The compound of claim 1 , wherein at least one of R A , R B , R C , or R D is nitrile.

7. The compound of claim 1 , wherein exactly one of R A , R B , R C , or R D is nitrile.

8. The compound of claim 1 , wherein exactly two of R A , R B , R C , and R D are nitrile.

9. The compound of claim 1 , wherein at least one of R A , R B , R C , or R D comprises a chemical group selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, azacarbazole, azadibenzofuran, azadibenzothiophene, tetraphenylene, and azatetraphenylene.

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

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

12. 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 of Formula I;

wherein each of Z 1 -Z 16 is independently C or N;

wherein each of R A , R B , R C , and R D represents mono to the maximum allowable substitution, or no substitution;

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

wherein at least one of Z 1 -Z 16 is N;

wherein at least one of R A , R B , R C , and R D is present and comprises a chemical group selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, triphenylene, azatriphenylene, azatetraphenylene, tetraphenylene, azacarbazole, azadibenzofuran, azadibenzothiophene, azadibenzoselenophene, azafluorene, benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, benzo[d]benzo[4,5]imidazo[2,1-b]oxazole, and benzo[d]benzo[4,5]imidazo[2,1-b]thiazole.

13. The OLED of claim 12 , wherein the organic layer is an emissive layer and the compound of Formula I is a host.

14. The OLED of claim 12 , 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 X 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, fluorine, alkyl, cycloalkyl, heteroalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, aryl, heteroaryl, nitrile, isonitrile, and combinations thereof; and

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

15. The OLED of claim 12 , wherein the organic layer is a blocking layer and the compound of Formula I is a blocking material in the organic layer.

16. The OLED of claim 12 , wherein the organic layer is a transporting layer and the compound of Formula I is a transporting material in the organic layer.

17. A consumer product comprising 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 of Formula I;

wherein each of Z 1 -Z 16 is independently C or N;

wherein each of R A , R B , R C , and R D represents mono to the maximum allowable substitution, or no substitution;

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

wherein at least one of Z 1 -Z 16 is N;

wherein at least one of R A , R B , R C , and R D is present and comprises a chemical group selected from the group consisting of carbazole, dibenzofuran, dibenzothiophene, dibenzoselenophene, triphenylene, azatriphenylene, azatetraphenylene, tetraphenylene, azacarbazole, azadibenzofuran, azadibenzothiophene, azadibenzoselenophene, azafluorene, benzo[d]benzo[4,5]imidazo[3,2-a]imidazole, benzo[d]benzo[4,5]imidazo[2,1-b]oxazole, and benzo[d]benzo[4,5]imidazo[2,1-b]thiazole.

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 wall comprising multiple displays tiled together, a theater or stadium screen, and a sign.

19. A formulation comprising a compound of claim 1 .