Oxazole Triplet Emitters for OLED Applications

• US 20110062858A1
• Filed: 07/27/2007
• Published: 03/17/2011
• Est. Priority Date: 07/28/2006
• Status: Active Grant

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Novaled AG
• Inventors: Reiser, Oliver, Yersin, Hartmut, Eibauer, Stefan, Li, Luo Qun
• Granted Patent: US 8,815,413 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C07D 263/32 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
• CPC Class Codes: C07D 263/34 with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
• CPC Class Codes: C07D 263/42 attached in position 5
• CPC Class Codes: C07D 263/57 Aryl or substituted aryl radicals
• CPC Class Codes: C07F 15/002 Osmium compounds
• CPC Class Codes: C07F 15/0033 Iridium compounds
• CPC Class Codes: C07F 15/0046 Ruthenium compounds
• CPC Class Codes: C07F 15/006 Palladium compounds
• CPC Class Codes: C07F 15/0086 Platinum compounds
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/346 comprising platinum

Abstract

The present invention relates to compounds which can be used in particular as ligands, to complexes and also to light-emitting devices and in particular to organic light-emitting devices (OLEDs). In particular, the invention relates to the use of luminescent oxazole-chelate metal complexes as emitters in such devices.

Claims

1. A complex of formula (I) or (II)

2. The complex according to claim 1, characterized in that M in formula (I) or (II) is Pt(II), Pd(II), Ir(III), Ru(II) or Os(II).

3. The complex according to claim 1 or 2, characterized in that X independently is nitrogen, oxygen or sulphur.

4. The complex according to any one of the preceding claims, characterized in that R¹ to R⁷ or R′

or R″

independently of one another are each hydrogen, alkyl, aryl, heteroaryl, alkenyl or alkynyl groups which may optionally he substituted.

5. The complex according to any one of the preceding claims, characterized in that R¹ to R⁷ or R′

or R″

independently of one another each comprise one or more substituents selected from halogens, in particular fluorine, and alkyl groups having 1 to 6, in particular 1 to 4 C atoms.

6. The complex according to any one of the preceding claims, characterized in that L¹, L² and L³ independently of one another are each selected from halogen, in particular chloride or bromide, pseudohalogen, in particular thiocyanate, cyanate or cyanide, and ligands which are bound to M via an element from group 16 of the Periodic Table, in particular oxygen or sulphur, from group 15 of the Periodic Table, in particular nitrogen, phosphorus or arsenic, or from group 14 of the Periodic Table, in particular carbon.

7. The complex according to any one of the preceding claims, selected from 5,5′

-di-tert-butyl-2,2′

-m-phenylene-bis-oxazole-2-platinum(II)bromide;

5,5′

-diphenyl-2,2′

-m-phenylene-bis-oxazole-2-platinum(II)bromide;

2,6-bis(5-ethoxyoxazol-2-yl)phenyl-bromoplatinum(II);

2-(4-methoxycarbonyloxazol-2-yl)-6-(5-ethoxyoxazol-2-yl)phenyl-bromoplatinum(II);

(3-oxo-3-ethoxypropynyl)-[2,6-bis(5-ethoxyoxazol-2-yl)phenyl]-platinum(II);

(3-hydroxylpropynyl)-[2,6-bis(5-ethoxyoxazol-2-yl)phenyl]-platinum(II);

5,5′

-di-tert-butyl-2,2′

-m-phenylene-bis-oxazole-2-palladium(II)bromide;

5,5′

-diphenyl-2,2′

-m-phenylene-bis-oxazole-2-palladium(II)bromide; and

from

24. The light-emitting device according to any one of the preceding claims, characterized in that it comprises as the emitter the compound:

5,5′

-di-tert-butyl-2,2′

-m-phenylene-bis-oxazole-2-platinum(II) bromide;

5,5′

-diphenyl-2,2′

-m-phenylene-bis-oxazole-2-platinum(II)bromide;

2,6-bis(5-ethoxyoxazol-2-yl)phenyl-bromoplatinum(II);

2-(4-methoxycarbonyloxazol-2-yl)-6-(5-ethoxyoxazol-2-yl)phenyl-bromoplatinum(II);

(3-oxo-3-ethoxypropynyl)-[2,6-bis(5-ethoxyoxazol-2-yl)phenyl]-platinum(II);

(3-hydroxylpropynyl)-[2,6-bis(5-ethoxyoxazol-2-yl)phenyl]platinum(II);

5,5′

-di-tert-butyl-2,2′

-m-phenylene-bis-oxazole-2-palladium(II)bromide;

5,5′

-diphenyl-2,2′

-m-phenylene-bis-oxazole-2-palladium(II)bromide,

or

8. A ligand of formula (III)

9. A compound of formula (IV)

10. The compound according to claim 9, selected from

11. A light-emitting device, comprising

(i) an anode,

(ii) a cathode and

(iii) an emitter layer arranged between and in direct or indirect contact with the anode and the cathode, comprising at least one complex of formula (I) or (II)

12. The light-emitting device according to claim 11, characterized in that it furthermore comprises a hole transport layer or/and an electron transport layer.

13. The light-emitting device according to claim 11 or 12, characterized in that it furthermore comprises a CsF or LiF intermediate layer.

14. The light-emitting device according to any one of the preceding claims 11 to 13, characterized in that it is arranged on a substrate, in particular on a glass substrate.

15. The light-emitting device according to any one of the preceding claims 11 to 14, characterized in that the complex contained in the emitter layer is a triplet emitter.

16. The light-emitting device according to any one of the preceding claims 11 to 15, characterized in that M is in an oxidation stage 0 to +4,

17. The light-emitting device according to any one of the preceding claims 11 to 16, characterized in that the emitter layer contains complexes of formula (I) or/and (II) in a concentration of 1 to 100% by weight, relative to the total weight of the emitter layer.

18. The light-emitting device according to any one of the preceding claims 11 to 17 characterized in that the proportion of complexes of formula (I) in the emitter layer is more than 80% by weight, in particular more than 90% by weight, relative to the total weight of the emitter layer.

19. The light-emitting device according to claim 18, characterized in that the complexes of formula (I) in the emitter layer exist as oligomers.

20. The light-emitting device according to any one of claims 11 to 17, characterized in that the proportion of complexes of formula (I) in the emitter layer is more than 10% by weight, in particular more than 20% by weight and up to 80% by weight, in particular up to 70% by weight, relative to the total weight of the emitter layer.

21. The light-emitting device according to claim 20, characterized in that the complexes of formula (I) in the emitter layer exist both as monomers and as oligomers.

22. The light-emitting device according to any one of claims 11 to 17, characterized in that the proportion of complexes of formula (I) or/and (II) in the emitter layer is more than 2% by weight, in particular more than 4% by weight and up to 10% by weight, in particular up to 8% by weight, relative to the total weight of the emitter layer.

23. The light-emitting device according to claim 22, characterized in that the complexes of formula (I) or/and (II) in the emitter layer exist as monomers.

25. The light-emitting device according to any one of the preceding claims 11 to 24, characterized in that it comprises at least two different complexes of formula (I) or (II).

26. The light-emitting device according to claim 25, characterized in that the emitter layer comprises at least one complex of formula (I) where M=Pt and at least one complex of formula (I) or (II) where M=Pd.

27. The light-emitting device according to any one of claims 11 to 17, characterized in that the emitter layer contains complexes of formula (I) where M=Pd(II) in a proportion of more than 80% by weight and complexes of formula (I) where M=Pt(II) in a proportion of less than 10% by weight, in each case relative to the total weight of the emitter layer.

28. The light-emitting device according to any one of the preceding claims 11 to 27, characterized in that it comprises crystalline or/and quasi-crystalline layers of complexes of formula (I).

29. The light-emitting device according to any one of the preceding claims 11 to 28, characterized in that it is an OLED.

30. The light-emitting device according to any one of the preceding claims 11 to 29, characterized in that it is a display or/and a lighting device.

32. The use according to claim 25 as a triplet emitter.

33. A method for producing a light-emitting device according to any one of claims 11 to 30, characterized in that at least one complex of formula (I) or (II) is incorporated in the emitter layer by means of vacuum sublimation.

34. A method for producing a light-emitting device according to any one of claims 11 to 30, characterized in that at least the complex of formula (I) or (II) is incorporated in the emitter layer via a wet chemical process.

31. The use of a complex of formula (I) or (II) as an emitter in a light-emitting device.