Compound comprising phenyl pyridine units

1. A compound of formula I

wherein

R 1 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical;

a is, independently at each occurrence, an integer ranging from 0-4;

b is 0, 1 or 2;

Ar 1 is a direct bond or heteroaryl, aryl, or alkyl or cycloalkyl;

Ar 2 is heteroaryl, aryl, or alkyl or cycloalkyl;

c is an integer ranging from 1-7; and

n is an integer ranging from 2-4.

2. The compound according to claim 1 , being of formula

3. The compound according to claim 1 , wherein Ar 1 is a direct bond.

4. The compound according to claim 1 , wherein Ar 1 is chosen from

R 2 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, a C 3 -C 20 cycloaliphatic radical, an aryl groups or a heteroaryl group.

5. The compound according to claim 1 , wherein Ar 2 is chosen from

and

R 2 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, a C 3 -C 20 cycloaliphatic radical, an aryl groups or a heteroaryl group, and

R 3 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, a C 3 -C 20 cycloaliphatic radical, an aryl group or a heteroaryl group and d is an integer ranging from 0-5.

6. The compound according to claim 5 , wherein Ar 2 is chosen from

7. The compound according to claim 5 , wherein Ar 1 and Ar 2 are independently chosen from

8. The compound according to claim 5 , wherein Ar 1 and Ar 2 are independently chosen from

9. The compound according to claim 1 , chosen from

10. A compound of formula

wherein

R 1 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical;

a is, independently at each occurrence, an integer ranging from 0-4;

R 2 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, a C 3 -C 20 cycloaliphatic radical, an alkyl, an aryl group or a heteroaryl group;

R 4 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, a C 3 -C 20 cycloaliphatic radical, an aryl group or a heteroaryl group;

e is an integer ranging from 0-3; and

m is an integer ranging from 1-7.

11. The compound according to claim 10 , wherein R 2 is aryl or alkyl.

12. The compound according to claim 10 , wherein R 2 is C 6 H 13 or C 8 H 17 .

13. The compound according to claim 10 , being of formula

14. The compound according to claim 10 , being of formula

15. The compound according to claim 10 , being of formula

16. The compound according to claim 10 , being of formula

17. An optoelectronic device comprising at least one compound of formula I

wherein

R 1 is, independently at each occurrence, a C 1 -C 20 aliphatic radical, a C 3 -C 20 aromatic radical, or a C 3 -C 20 cycloaliphatic radical;

a is, independently at each occurrence, an integer ranging from 0-4;

b is 0, 1 or 2;

Ar 1 is a direct bond or heteroaryl, aryl, or alkyl or cycloalkyl;

Ar 2 is heteroaryl, aryl, or alkyl or cycloalkyl;

c is an integer ranging from 1-7; and

n is an integer ranging from 2-4.

18. The optoelectronic device according to claim 17 , wherein the at least one compound is of formula

19. The optoelectronic device according to claim 17 , being an organic light emitting device.

20. The optoelectronic device according to claim 19 , having an electron transporting layer comprising the at least one compound of formula I.

21. The optoelectronic device according to claim 19 , having a hole transporting layer comprising the at least one compound of formula I.

22. The optoelectronic device according to claim 19 , having an emissive layer comprising the at least one compound of formula I.

23. The optoelectronic device according to claim 20 , additionally comprising at least one of blue, yellow, orange, green and red phosphorescent dyes, or a combination thereof.