Fluorescent bis-coumarins for organic light-emitting devices

• US 6,770,385 B2
• Filed: 01/09/2002
• Issued: 08/03/2004
• Est. Priority Date: 01/09/2002
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Inc.
• Inventors: Chen, Jian Ping, Hsieh, Bing R., Thoms, Travis P. S.
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US10/040,764
• Publication Number:
  US 20030164499A1
• Time in Patent Office: 937 Days
• Field of Search: 428/690, 428/917, 313/504, 252/301.16, 252/301.32, 549/283, 549/284, 549/285, 549/288
• US Class Current: 428/690
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/6574 comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

A fluorescent compound, suitable for use in an active layer of an organic light-emitting device and exhibiting both good luminescence and excellent thermal stability, which has the structure

wherein R is substituted or unsubstituted alkyl; wherein Ar₂ is optionally present; and wherein Ar₁, Ar₂, and Ar₃ are independently each a substituted or unsubstituted aryl group.

Claims

1. A fluorescent compound having a structure

wherein R is the same or different and is selected from the group consisting of —

H and C₁-C₁₀ alkyl;

wherein Ar₂ is optionally present;

wherein Ar₁ is selected from the group consisting of

 

and substituted derivatives thereof; and

wherein Ar₂ and Ar₃ are independently selected from the group consisting of

 

and substituted derivatives thereof.

2. The fluorescent compound according to claim 1, wherein R is CH₃.

3. The fluorescent compound according to claim 1, wherein the fluorescent compound is N,N′

-diphenyl-N,N′

-di-7″

-(N-phenyl)-amino-3″

-methyl-coumarin-1,1′

-biphenyl-4,4′

-diamine having the structure

4. The fluorescent compound according to claim 1, wherein the fluorescent compound is N,N′

-diphenyl-N,N′

-di-7″

-(N-p-anisole)-amino-3″

-methyl-coumarin-1,1′

-biphenyl-4,4′

-diamine having the structure

5. The fluorescent compound according to claim 1, wherein the fluorescent compound is N,N′

-diphenyl-N,N′

-di-7″

-(N-4′

-biphenyl)-amino-3″

-methyl-coumarin-1,1′

-biphenyl-4,4′

-diamine having the structure

6. An organic light emitting device comprising:

(a) a transparent anode;

(b) a cathode; and

(c) an emissive layer containing a fluorescent compound according to any one of claims 1-5 as a dopant.

7. The organic light emitting device according to claim 6 wherein the fluorescent compound is present in an amount of from about 0.1 to about 5 wt. % based on the weight of the emissive layer.

8. A method of making a fluorescent compound according to any one of claims 1-5 comprising the step of reacting an arylamino-substituted coumarin and a halo-substituted aryl in the presence of a catalytic metal to form the fluorescent compound.

9. The method according to claim 8, wherein the arylamino-substituted coumarin is selected from the group consisting of 7-(N-phenyl)-amino-3-methyl-coumarin, 7-(N-p-anisole)-amino-3-methyl-coumarin, 7-(N-4′

-biphenyl)-amino-3-methyl-coumarin and 7-(N-9′

,9′

-dimethyl)-2′

-fluorenyl)-amino-3-methyl-coumarin.