Organic electroluminescent materials and devices

1. A first device comprising a first organic light emitting device, comprising:

an anode;

a cathode; and

an emissive layer, disposed between the anode and the cathode;

wherein the emissive layer comprises a compound having the formula:

wherein Z 1 , Z 2 , Z 3 , Z 4 and Z 5 are each independently selected from group consisting of CR 9 and N;

wherein any adjacent R 9 are optionally joined to form a fused ring;

wherein at least one of Z 1 , Z 2 , Z 3 , Z 4 and Z 5 is N;

wherein L 1 is selected from the group consisting of:

and combinations thereof;

wherein X 1 is O, S, or CRR′;

wherein R, R′ are optionally joined to form a ring;

wherein n 1 is an integer from 1 to 20;

wherein L 1 can be further substituted by a substituent selected from the group consisting of alkyl, aryl, and heteroaryl;

wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group selected from the group consisting of:

wherein X and Y is selected from the group consisting of O, S, NR 14 ; and

wherein R 11 , R 12 , R 13 and R 14 are selected from the group consisting of aryl and heteroaryl;

wherein any two adjacent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are not joined to form a ring;

wherein m is an integer from 1 to 20;

wherein n 2 is an integer from 1 to 20;

wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 do not contain an electron acceptor group;

wherein R 9 does not contain an electron donor group;

wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof;

wherein R 9 , R, and R′ are independently selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, heteroalkyl, arylalkyl, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, and combinations thereof; and

wherein at least one of Z 1 , Z 2 , Z 3 , Z 4 and Z 5 is CR 9 wherein R 9 is selected from aryl and heteroaryl, and can be further substituted.

2. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises the electron donor group selected from the group consisting of:

3. The first device of claim 1 , wherein the compound has the formula:

and

wherein R 91 and R 92 are independently selected from aryl or heteroaryl, and can be further substituted.

4. The first device of claim 1 , wherein the electron donor group is selected from the group consisting of:

5. The first device of claim 1 , wherein the compound is selected from the group consisting of:

6. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

7. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

8. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

9. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

10. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

11. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

12. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

13. The first device of claim 1 , wherein at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 comprises at least one electron donor group having the structure

14. The first device of claim 1 , wherein L 1 is

15. The first device of claim 1 , wherein L 1 is

16. The first device of claim 1 , wherein L 1 is

17. The first device of claim 1 , wherein L 1 is

18. The first device of claim 1 , wherein L 1 is

19. The first device of claim 1 , wherein the first device is a consumer product selected from the group consisting of flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior illumination and/or signaling, heads up displays, fully transparent displays, flexible displays, laser printers, telephones, cell phones, personal digital assistants (PDAs), laptop computers, digital cameras, camcorders, viewfinders, micro-displays, vehicles, a large area wall, theater or stadium screen, and a sign.