Synthesis of four coordinated palladium complexes and their applications in light emitting devices thereof

1. A compound represented by the formula:

wherein:

each R 1 and R 2 in (R 1 ) 2 and (R 2 ) 2 independently represents hydrogen;

Y 1a represents O;

n is an integer 0;

each of Y 2a Y 2b Y 2c and Y 2d independently represents N, C, or CH;

each of Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e independently represents N, NR 6a , C or CR 6b , wherein each of R 6a and R 6b independently represents hydrogen or optionally substituted C 1 -C 4 alkyl, and the ring which comprises the Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e groups is a heteroaryl group having one or two nitrogen atoms, wherein the heteroaryl group is unsubstituted or substituted with one or more optionally substituted C 1 -C 4 alkyl;

each of Y 4a , Y 4b , Y 4c , and Y 4d independently represents N, NR 6a , C or CR 6b , wherein each of R 6a and R 6b independently represents hydrogen or optionally substituted C 1 -C 4 alkyl, and the ring which comprises the Y 4a , Y 4b , Y 4c , and Y 4d groups is a heteroaryl group having one or two nitrogen atoms, wherein the heteroaryl group is unsubstituted or substituted with one or more optionally substituted C 1 -C 4 alkyl;

m is an integer 1.

2. An organic light-emitting diode (OLED) comprising, as an emissive material, a compound represented by the formula of claim 1 .

3. An organic photovoltaic device comprising, as a donor or acceptor material, a compound represented by the formula of claim 1 .

4. The compound of claim 1 , which is represented by the formula:

5. The compound of claim 1 , which is represented by the formula:

6. An organic light-emitting diode (OLED) comprising, as an emissive material, a compound represented by the formula of claim 4 .

7. An organic photovoltaic device comprising, as a donor or acceptor material, a compound represented by the formula of claim 4 .

8. The compound of claim 1 , wherein the compound is represented by the formula:

9. The compound of claim 1 , wherein Y 2a , Y 2b , Y 2c , and Y 2d are N.

10. The compound of claim 1 , wherein Y 2a , Y 2b , Y 2c , and Y 2d are C or CH.

11. The compound of claim 1 , wherein one of Y 2a , Y 2b , Y 2c , and Y 2d is N and the others are C or CH.

12. The compound of claim 1 , wherein two of Y 2a , Y 2b , Y 2c , and Y 2d are N and the others are C or CH.

13. The compound of claim 1 , wherein three of Y 2a , Y 2b , Y 2c , and Y 2d are N and the other is C or CH.

14. The compound of claim 1 , wherein the ring which comprises Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e groups is a heteroaryl group having one nitrogen atom.

15. The compound of claim 1 , wherein the ring which comprises Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e groups is a heteroaryl group having two nitrogen atoms.

16. The compound of claim 1 , wherein the ring which comprises Y 3a , Y 3b , Y 3c , Y 3d , and Y 3e groups is a pyrazolyl group.

17. The compound of claim 1 , wherein the ring which comprises Y 4a , Y 4b , Y 4c , and Y 4d groups is a heteroaryl group having one nitrogen atom.

18. The compound of claim 1 , wherein the ring which comprises Y 4a , Y 4b , Y 4c , and Y 4d groups is a heteroaryl group having two nitrogen atoms.

19. The compound of claim 1 , wherein the ring which comprises Y 4a , Y 4b , Y 4c , and Y 4d groups is a pyrazolyl group.

20. The compound of claim 1 , which is represented by the formula:

21. The compound of claim 1 , which is represented by the formula:

22. The compound of claim 1 , which is represented by the formula:

23. The compound of claim 1 , which is represented by the formula: