Fluorescent Organic Light Emitting Elements Having High Efficiency

Abstract

An organic light-emitting element which emits delayed fluorescence comprising specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives or 1,2,4-thiadiazole derivatives in the light-emitting layer, a light-emitting layer comprising the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives or 1,2,4-thiadiazole derivatives, specific specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives and an organic light emitting element comprising the specific 1,2,4-azole derivatives as well as a light emitting layer comprising the specific 1,2,4-azole derivatives; the use of the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives for electrophotographic photoreceptors, photoelectric converters, sensors, dye lasers, solar cell devices and organic light emitting elements, and the use of the specifically substituted 1,2,4-triazole derivatives, 1,2,4-oxadiazole derivatives and 1,2,4-thiadiazole derivatives for generating delayed fluorescence emission.

Claims

1. An organic light-emitting element, comprising a light-emitting layer comprising i) a compound of formula ##STR00087## as guest and a host material; or ii) a compound of formula ##STR00088## as host and a fluorescent guest material, wherein X is O, S or N—Y.sup.4—R.sup.4, Y.sup.1 and Y.sup.2 and Y.sup.4 are independently of each other a direct bond, C.sub.1-C.sub.25-alkylene, or C.sub.6-C.sub.10-arylene, which is unsubstituted or substituted by one or more groups R.sup.3; R.sup.1 and R.sup.2 are independently of each other hydrogen, deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, which is unsubstituted or substituted by one or more groups R.sup.3, a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); R.sup.3 is deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, or a C.sub.6-C.sub.14aryl group; R.sup.4 is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); ##STR00089## X.sup.1 is O, S, N(R.sup.15), C(═O), C(R.sup.16)(R.sup.17), B(R.sup.18), or Si(R.sup.19)(R.sup.20); R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, which is unsubstituted or substituted by one or more groups R.sup.3, or a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3; R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.19 and R.sup.20 are independently of each other a C.sub.1-C.sub.25alkyl group, or a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3; wherein at least one group of formula (Xa), or (Xd) is present in the compound of formula (I), characterized in that it emits delayed fluorescence.

2. The organic light-emitting element according to claim 1, wherein Y.sup.1 and Y.sup.2 and Y.sup.4 are independently of each other a direct bond, or a group of formula ##STR00090##

3. The organic light-emitting element according to claim 1, wherein R.sup.1 and R.sup.2 are independently of each other hydrogen, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); R.sup.3 is a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryloxy group, or a C.sub.6-C.sub.14aryl group; R.sup.4 is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); X.sup.1 is O, S, C(O), N(R.sup.15), or C(R.sup.16)(R.sup.17); and R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; R.sup.15 is a group of formula ##STR00091## R.sup.16 and R.sup.17 are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; R.sup.22 and R.sup.23 are independently of each other hydrogen, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryloxy group, or a C.sub.6-C.sub.10aryl group; wherein at least one group of formula (Xa), or (Xd) is present in the compound of formula (I).

4. The organic light-emitting element according to claim 1, wherein the group of formula (Xa) or (Xd) is a group of formula (Xa), wherein X.sup.1 is O, S, C(CH.sub.3)(CH.sub.3), C(═O), ##STR00092## or a group of formula (Xd), wherein R.sup.21 and R.sup.21′ are hydrogen.

5. The organic light-emitting element according to claim 1, wherein the group of formula (Xa) or (Xd) is a group of formula ##STR00093##

6. The organic light-emitting element according to claim 1, wherein R.sup.1 and R.sup.2 are independently of each other hydrogen, a C.sub.6-C.sub.10aryl group, or a group of formula (Xa) or (Xd); R.sup.4 is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, or a group of formula (Xa) or (Xd); X.sup.1 is O, S, C(CH.sub.3)(CH.sub.3), C(═O), or ##STR00094## and R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; wherein at least one group of formula (Xa), or (Xd) is present in the compound of formula (I).

7. A light-emitting layer comprising at least one compound of formula (I) as described in claim 1 as guest and a host material.

8. A compound of formula ##STR00095## wherein X is O, S, N—Y.sup.4′—R.sup.4 or N—Y.sup.4″—R.sup.4, Y.sup.1 and Y.sup.2 are independently of each other a direct bond, C.sub.1-C.sub.25-alkylene, or C.sub.6-C.sub.10-arylene, which is unsubstituted or substituted by one or more groups R.sup.3; Y.sup.4′ is a direct bond, C.sub.1-C.sub.25-alkylene; Y.sup.4″ is C.sub.6-C.sub.10-arylene, which is unsubstituted or substituted by one or more groups R.sup.3; R.sup.1 and R.sup.2 are independently of each other hydrogen, deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, which is unsubstituted or substituted by one or more groups R.sup.3, a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); ##STR00096## R.sup.3 is deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, or a C.sub.6-C.sub.14aryl group; R.sup.4 is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); X.sup.1 is O, S, N(R.sup.15), C(═O), C(R.sup.16)(R.sup.17), B(R.sup.18), or Si(R.sup.19)(R.sup.20), or when X is N—Y.sup.4″—R.sup.4, X.sup.1 is N(R.sup.15′), C(═O), C(R.sup.16)(R.sup.17), B(R.sup.18), or Si(R.sup.19)(R.sup.20), R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, deuterium, F, Cl, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.14aryloxy group, which is unsubstituted or substituted by one or more groups R.sup.3, or a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3; R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.19 and R.sup.20 are independently of each other a C.sub.1-C.sub.25alkyl group, or a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3; R.sup.15′ is a C.sub.6-C.sub.14aryl group, which is unsubstituted or substituted by one or more groups R.sup.3; wherein at least one group of formula (Xa) or (Xd) is present in the compound of formula (I′).

9. The compound according to claim 8, wherein Y.sup.1 and Y.sup.2 are independently of each other a direct bond, or a group of formula ##STR00097## Y.sup.4′ is a direct bond; and Y.sup.4″ is a group of formula ##STR00098##

10. The compound according to claim 8, wherein R.sup.1 and R.sup.2 are independently of each other hydrogen, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); R.sup.3 is a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryloxy group, or a C.sub.6-C.sub.14aryl group; R.sup.4 is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, which is unsubstituted or substituted by one or more groups R.sup.3, or a group of formula (Xa) or (Xd); X.sup.1 is O, S, C(O), N(R.sup.15), or C(R.sup.16)(R.sup.17); or when X is N—Y.sup.4″—R.sup.4, X.sup.1 is N(R.sup.15′) or C(R.sup.16)(R.sup.17), and R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; R.sup.15 and R.sup.15′ are independently of each other a group of formula ##STR00099## R.sup.16 and R.sup.17 are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; R.sup.22 and R.sup.23 are independently of each other hydrogen, a C.sub.1-C.sub.25alkyl group, a C.sub.1-C.sub.25alkoxy group, a C.sub.6-C.sub.10aryloxy group, or a C.sub.6-C.sub.10aryl group; wherein at least one group of formula (Xa), or (Xd) is present in the compound of formula (I′).

11. The compound according to claim 8, wherein the group of formula (Xa) or (Xd) is a group of formula (Xa), wherein X.sup.1 is O, S, C(CH.sub.3)(CH.sub.3), C(═O), ##STR00100## or when X is N—Y.sup.4″—R.sup.4, X.sup.1 is C(CH.sub.3)(CH.sub.3), C(═O), ##STR00101## or a group of formula (Xd), wherein R.sup.21 and R.sup.21′ are hydrogen.

12. The compound according to claim 8, wherein the group of formula (Xa) or (Xd) is a group of formula ##STR00102## or when X is N—Y.sup.4″—R.sup.4, a group of formula ##STR00103##

13. The compound according to claim 8, wherein R.sup.1 and R.sup.2 are independently of each other hydrogen, a C.sub.6-C.sub.10aryl group, or a group of formula (Xa) or (Xd); R.sup.4′ is a C.sub.1-C.sub.25alkyl group, a C.sub.6-C.sub.10aryl group, or a group of formula (Xa) or (Xd); X.sup.1 is O, S, C(CH.sub.3)(CH.sub.3), C(═O), or ##STR00104## or when X is N—Y.sup.4″—R.sup.4, X.sup.1 is C(CH.sub.3)(CH.sub.3), C(═O), ##STR00105## and R.sup.10, R.sup.11, R.sup.21 and R.sup.21′ are independently of each other hydrogen, or a C.sub.1-C.sub.25alkyl group; wherein at least one group of formula (Xa), or (Xd) is present in the compound of formula (I′).

14. A light-emitting layer comprising the compound according to claim 8.

15. An organic light emitting element, comprising the compound according to claim 8.

16. The organic light-emitting element according to claim 15, comprising a light-emitting layer comprising the compound as guest and a host material.

17. The organic light-emitting element according to claim 15, comprising a light-emitting layer comprising the compound as host and a guest material.

18. The organic light-emitting element according to claim 1, characterized in that it emits light by delayed fluorescence.

19. A device selected from the group consisting of an electrophotographic photoreceptor, a photoelectric converter, a sensor, a dye laser, a solar cell device and an organic light emitting element, wherein the device comprises the organic light-emitting element of claim 1.

20. A method of generating delayed fluorescence emission, comprising adding the organic light-emitting element of claim 1 to a device or composition.

Description

EXAMPLES

Example 1

[0196] ##STR00083##

[0197] a) 4-Bromobenzonitrile (56 mmol) and Ethanol (35 g) are placed in a 100 ml flask. While stirring, Acetyl chloride (448 mmol) is slowly added. The mixture is stirred at room temperature overnight (15 hours). After the reaction is completed, Ethanol is removed by evaporation, then the residue is washed with Diethyl ether. White solid is obtained by drying in vacuum. (Yield: 84.4%) The product is used for the next reaction without further purification.

##STR00084##

[0198] b) The product from example 1a (11.3 mmol), Triethylamine (24.9 mmol), 4-Bromobenzoyl chloride (11.3 mmol) and 35 ml of dichloromethane are placed in a 100 ml flask. The mixture is stirred at −15° C. to room temperature overnight (15 hours). After the reaction is completed, dichloromethane is removed by evaporation, then the residue is washed with warm Tetrahydrofuran. White solid is obtained by drying in vacuum. (Crude, Yield: 105%). The product is used for the next reaction without further purification.

##STR00085##

[0199] c) The product from example 1b (11.3 mmol), phenylhydrazine (12.5 mmol), and 70 ml of tetrachloromethane are placed in a 100 ml flask. The mixture is stirred at room temperature overnight (15 hours). After the reaction is completed, tetrachloromethane is removed by evaporation. The crude product is purified by column chromatography with dichloromethane/hexane=1/30-1/1 as eluent. Beige solid is obtained by drying in vacuum. (yield: 16.5%). .sup.1H-NMR (ppm, CDCl.sub.3): 8.09 (dd, 2H), 7.59 (dd, 2H), 7.52-7.39 (m, 9H)

##STR00086##

[0200] d) The product from example 1c (0.66 mmol), phenoxazine (1.35 mmol), Tris(dibenzylideneacetone) dipalladium (0.013 mmol), tri-tert-butylphosphine (0.026 mmol), sodium t-buthoxide (1.98 mmol) and 7 ml of toluene are placed in a 50 ml flask. The mixture is stirred at 110° C. overnight and cooled. The mixture is filtered and the solid is washed with hexane, subsequently purified by column chromatography with dichloromethane/hexane=1/5 as eluent. Pale yellow solid is obtained by drying in vacuum. (yield: 81.4%). The product is subsequently purified using zone sublimation. .sup.1H-NMR (ppm, CDCl.sub.3): 8.47 (d, 2H), 7.80 (d, 2H), 7.52 (m, 5H), 7.47 (d, 2H), 7.38 (d, 2H), 6.68 (m, 12H), 6.01 (dd, 2H), 5.94 (dd, 2H)

[0201] An organic light-emitting diode prepared comprising a light-emitting layer comprising the compound A-1 emits light with a high external quantum efficiency.