Compound, Intermediate of the Compound, Process for Preparing the Compound, Organic Semiconducting Material Comprising the Compound, Organic Electronic Device Comprising the Same, and Display Device and Lighting Device Comprising the Same

Abstract

The present invention relates to a compound having the Formula (I) an intermediate of the compound, a process for preparing the compound, an organic semiconducting material comprising the compound and an organic electronic device comprising the same. The invention further relates to a display device or a lighting device comprising the organic electronic device.

##STR00001##

Claims

1. Compound of the following Formula (I) ##STR00048## wherein A is substituted or unsubstituted phenylene, wherein, in case that A is substituted, the one or more substituent(s) are independently selected hydrocarbyl groups; G is (i) substituted or unsubstituted C.sub.10 to C.sub.60 aryl comprising at least two condensed aromatic rings; or (ii) substituted or unsubstituted C.sub.3 to C.sub.60 heteroaryl comprising at least one six-membered ring, wherein the six-membered ring comprises at least two N-atoms; or (iii) substituted or unsubstituted heteroaryl comprising at least two condensed aromatic rings, wherein at least one of the aromatic rings is an azine ring; or (iv) selected from benzofurane, benzothiophene, dibenzothiophene, naphtofurane, naphtothiophene, naphtobenzofurane, naphtobenzothiophene, dinaphtofurane, dinaphtothiophene, xanthene, thioxanthene, dibenzodioxine, phenoxazine, phenothiazine, benzimidazole, benzoxazole, and benzothiazole, wherein the respective group may be unsubstituted or substituted; or (v) selected from fluorene, benzofluorene, dibenzofluorene, naphtofluorene, dinaphtofluorene, benzonaphtofluorene, 9-silafluorene, benzo 9-silafluorene, dibenzo 9-silafluorene, naphto 9-silafluorene, dinaphto 9-silafluorene, and benzonaphto 9-silafluorene; R.sup.1 is (i) H; or (ii) substituted or unsubstituted pyridyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) substituted or unsubstituted phenyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are nitrile; or (iv) a phosphine oxide group; R.sup.2 and R.sup.3 are independently (i) substituted or unsubstituted pyridyl, wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted or unsubstituted phenyl wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) a phosphine oxide group; with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is (i) substituted or unsubstituted pyridyl, wherein the one or more substituent(s) on the pyridyl, if present, are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted phenyl wherein (a) the one or more substituent(s) of the phenyl are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile, and (b) at least one of the substituents is nitrile; or (iii) a phosphine oxide group.

2. Compound according to claim 1, wherein A is unsubstituted phenylene.

3. Compound according to claim 1, wherein G is (i) substituted or unsubstituted C.sub.10 to C.sub.60 aryl comprising at least two condensed aromatic rings; or (ii) substituted or unsubstituted C.sub.3 to C.sub.60 heteroaryl comprising at least one six-membered ring, wherein the six-membered ring comprises at least two N-atoms; or (iii) substituted or unsubstituted heteroaryl comprising at least two condensed aromatic rings, wherein at least one of the aromatic rings is an azine ring.

4. Compound according to claim 1, wherein G is represented by the following Formula (II) ##STR00049## wherein represents the binding to the group A; X.sup.1 to X.sup.3 are independently selected from the group consisting of N and CH, wherein at least two of X.sup.1 to X.sup.3 are N; and R.sup.4 and R.sup.5 are independently selected from the group consisting of C.sub.6 to C.sub.30 aryl and C.sub.3 to C.sub.30 heteroaryl.

5. Compound according to claim 1, wherein R.sup.1 is H, phenyl, pyridyl or phenyl substituted with one nitrile.

6. Compound according to claim 1, wherein R.sup.2 and R.sup.3 are independently selected from the group consisting of phenyl, pyridyl and phenyl substituted with one nitrile.

7. Compound according to claim 1, wherein at least one of R.sup.2 and R.sup.3 is selected from unsubstituted pyridyl, pyridyl substituted with at least one C.sub.1 to C.sub.20 aliphatic hydrocarbyl, and phenyl substituted with at least one nitrile group.

8. Compound according to claim 1, wherein R.sup.1 is H or phenyl and at least one of R.sup.2 and R.sup.3 is selected from unsubstituted pyridyl, pyridyl substituted with at least one C.sub.1 to C.sub.20 aliphatic hydrocarbyl, and phenyl substituted with at least one nitrile group.

9. Organic semiconducting material comprising the compound of Formula (I) according to claim 1.

10. Organic electronic device comprising a first electrode, a second electrode and an organic semiconducting layer arranged between the first electrode and the second electrode, wherein the semiconducting layer comprises a compound of Formula (I) according to claim 1.

11. Organic electronic device according to claim 10, wherein the semiconducting layer comprising the compound of Formula (I) is an electron transport layer, an electron injection layer, a hole blocking layer or an electron generating layer.

12. Display device comprising an organic electronic device according to claim 10.

13. Use of the compound of Formula (I) according to claim 1 for preparing an organic electronic device.

14. Process for preparing a compound of Formula (I) according to claim 1 ##STR00050## the process comprising reacting a compound of the following formula (IV) and a compound of the following formula (V) ##STR00051## wherein A is substituted or unsubstituted phenylene, wherein, in case that A is substituted, the one or more substituent(s) are independently selected hydrocarbyl groups; G is (i) substituted or unsubstituted C.sub.10 to C.sub.60 aryl comprising at least two condensed aromatic rings; or (ii) substituted or unsubstituted C.sub.3 to C.sub.60 heteroaryl comprising at least one six-membered ring, wherein the six-membered ring comprises at least two N-atoms; or (iii) substituted or unsubstituted heteroaryl comprising at least two condensed aromatic rings, wherein at least one of the aromatic rings is an azine ring; or (iv) selected from benzofurane, benzothiophene, dibenzothiophene, naphtofurane, naphtothiophene, naphtobenzofurane, naphtobenzothiophene, dinaphtofurane, dinaphtothiophene, xanthene, thioxanthene, dibenzodioxine, phenoxazine, phenothiazine, benzimidazole, benzoxazole, and benzothiazole, wherein the respective group may be unsubstituted or substituted; or (v) selected from fluorene, benzofluorene, dibenzofluorene, naphtofluorene, dinaphtofluorene, benzonaphtofluorene, 9-silafluorene, benzo 9-silafluorene, dibenzo 9-silafluorene, naphto 9-silafluorene, dinaphto 9-silafluorene, and benzonaphto 9-silafluorene; R.sup.1 is (i) H; or (ii) substituted or unsubstituted pyridyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) substituted or unsubstituted phenyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are nitrile; or (iv) a phosphine oxide group; R.sup.2 and R.sup.3 are independently (i) substituted or unsubstituted pyridyl, wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted or unsubstituted phenyl wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) a phosphine oxide group; and Z.sup.1, Z.sup.2 are independently selected from the group consisting of halogen, boronic acid, sulfonic acid ester and boronate ester; with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is (i) substituted or unsubstituted pyridyl, wherein the one or more substituent(s) of the pyridyl, if present, are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted phenyl wherein (a) the one or more substituent(s) of the phenyl are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile, and (b) at least one of the substituents is nitrile; or (iii) a phosphine oxide group.

15. Compound of the following formula (VI) ##STR00052## wherein R.sup.1 is (i) H; or (ii) substituted or unsubstituted pyridyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) substituted or unsubstituted phenyl, wherein, in case that R.sup.1 is substituted, the one or more substituent(s) are nitrile; or (iv) a phosphine oxide group; R.sup.2 and R.sup.3 are independently (i) substituted or unsubstituted pyridyl, wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted or unsubstituted phenyl wherein, in case that R.sup.2 and/or R.sup.3 are substituted, the one or more substituent(s) are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (iii) a phosphine oxide group and Z.sup.1, Z.sup.2 are groups independently selected from halogen, boronic acid group, sulfonic acid ester group and boronate ester group; with the proviso that at least one of R.sup.1, R.sup.2 and R.sup.3 is (i) substituted or unsubstituted pyridyl, wherein the one or more substituent(s) of the pyridyl, if present, are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile; or (ii) substituted phenyl wherein (a) the one or more substituent(s) of the phenyl are independently selected from the group consisting of C.sub.1 to C.sub.20 aliphatic hydrocarbyl and nitrile, and (b) at least one of the substituents is nitrile; or (iii) a phosphine oxide group.

Description

DESCRIPTION OF THE DRAWINGS

[0354] These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, of which:

[0355] FIG. 1 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention;

[0356] FIG. 2 is a schematic sectional view of an OLED, according to an exemplary embodiment of the present invention.

[0357] FIG. 3 is a schematic sectional view of a tandem OLED comprising a charge generation layer, according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

[0358] Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below, in order to explain the aspects of the present invention, by referring to the figures.

[0359] Herein, when a first element is referred to as being formed or disposed “on” or “onto” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” or “directly onto” a second element, no other elements are disposed there between.

[0360] FIG. 1 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate 110, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an emission layer (EML) 150, an electron transport layer (ETL) 160. The electron transport layer (ETL) 160 is formed on the EML 150. Onto the electron transport layer (ETL) 160, an electron injection layer (EIL) 180 is disposed. The cathode 190 is disposed directly onto the electron injection layer (EIL) 180.

[0361] Instead of a single electron transport layer 16o, optionally an electron transport layer stack (ETL) can be used.

[0362] FIG. 2 is a schematic sectional view of an OLED 100, according to another exemplary embodiment of the present invention. FIG. 2 differs from FIG. 1 in that the OLED 100 of FIG. 2 comprises an electron blocking layer (EBL) 145 and a hole blocking layer (HBL) 155.

[0363] Referring to FIG. 2, the OLED 100 includes a substrate 11o, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, an emission layer (EML) 150, a hole blocking layer (HBL) 155, an electron transport layer (ETL) 160, an electron injection layer (EIL) 180 and a cathode electrode 190.

[0364] Preferably, the organic semiconducting layer comprising a compound (I) or consisting of a compound (I) may be an EML, an HBL or an ETL.

[0365] FIG. 3 is a schematic sectional view of a tandem OLED 200, according to another exemplary embodiment of the present invention. FIG. 3 differs from FIG. 2 in that the OLED 200 of FIG. 3 further comprises a charge generation layer (CGL) and a second emission layer (151).

[0366] Referring to FIG. 3, the OLED 200 includes a substrate no, an anode 120, a first hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first electron blocking layer (EBL) 145, a first emission layer (EML) 15o, a first hole blocking layer (HBL) 155, a first electron transport layer (ETL) 160, an n-type charge generation layer (n-type CGL) 185, a hole generating layer (p-type charge generation layer; p-type GCL) 135, a second hole transport layer (HTL) 141, a second electron blocking layer (EBL) 146, a second emission layer (EML) 151, a second hole blocking layer (EBL) 156, a second electron transport layer (ETL) 161, a second electron injection layer (EIL) 181 and a cathode 190.

[0367] Preferably, the organic semiconducting layer comprising a compound (I) or consisting of a compound (I) may be the first EML, first HBL, first ETL, n-type CGL and/or second EML, second HBL, second ETL.

[0368] While not shown in FIG. 1, FIG. 2 and FIG. 3, a sealing layer may further be formed on the cathode electrodes 190, in order to seal the OLEDs 100 and 200. In addition, various other modifications may be applied thereto.

DETAILED DESCRIPTION

[0369] Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples. Reference will now be made in detail to the exemplary aspects.

Synthesis of Compounds

[0370] The abbreviations used in synthesis procedures have the following meaning:

[0371] Et is ethyl, Ph is phenyl, Ac is acetyl, Tf is trifloromethylsulfonyl, EtOAc is ethyl acetate, DCM is dichloromethane, THF is tetrahydrofuran, Tf.sub.2O is trifluoromethane sulfonic acid anhydride, SPhos is 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl, dppf is 1,1′-ferrocenediyl-bis(diphenylphosphine), APCI is atmospheric pressure chemical ionization, ESI is electrospray ionization, MS is mass spectrometry.

Synthesis of Intermediates

3-(5′-bromo-[1,1′:4′,1″-terphenyl]-2′-yl)pyridine

[0372] ##STR00035##

[0373] A flask was flushed with argon and charged with 2′,5′-dibromo-1,1′:4′,1″-terphenyl (57.7 g, 148.7 mmol), pyridin-3-ylboronic acid (24.3 g, 148.7 mmol), Pd(OAc).sub.2 (1.7 g, 7.4 mmol), PPh.sub.3 (7.8 g, 29.7 mmol) and K.sub.3PO.sub.4 (63.1 g, 297.4 mmol). A mixture of deaerated 1,4-dioxane/water (3:1, 1.1 L) was added and the reaction mixture was heated to 82° C. under an argon atmosphere for 26 h. After cooling down to room temperature, the crude product was extracted with a DCM/aqueous K.sub.2CO.sub.3 mixture, the extract evaporated under reduced pressure and dried. Further purification was achieved via silica gel column chromatography and recrystallization from petroleum ether/DCM (20:1, 158 mL) to yield 28.1 g (49%) of a white solid after drying.

[0374] APCI-MS: m/z=384 ([M−H]+).

4-(5′-bromo-[1,1′:4′,1″-terphenyl]-2′-yl)pyridine

[0375] ##STR00036##

[0376] A flask was flushed with argon and charged with 2′,5′-dibromo-1,1′:4′,1″-terphenyl (40.4 g, 104.1 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (21.8 g, 104.1 mmol), Pd(OAc).sub.2 (1.2 g, 5.2 mmol), PPh.sub.3 (5.5 g, 20.8 mmol) and K.sub.3PO.sub.4 (44.2 g, 208.3 mmol). A mixture of deaerated 1,4-dioxane/water (3:1, 1 L) was added and the reaction mixture was heated to 82° C. under an argon atmosphere overnight. After cooling down to room temperature, the crude product was extracted with a DCM/aqueous K.sub.2CO.sub.3 mixture, the extract evaporated under reduced pressure and dried. Further purification was achieved via silica gel column chromatography and recrystallization from methanol/DCM (100:3, 515 mL) to yield 27.7 g (69%) of a white solid after drying.

[0377] APCI-MS: m/z=385 ([M]+).

5′-(pyridin-3-yl)-[1,1′: 4′,1″-terphenyl]-2′-yl trifluoromethanesulfonate

[0378] ##STR00037##

Step 1

5′-(pyridin-3-yl)-[1,1′:4′,1″-terphenyl]-2′-ol

[0379] A flask was flushed with argon and charged with 2,5-dichloro-4-(pyridin-3-yl)phenol (52.5 g, 218.6 mmol), phenylboronic acid (80.8 g, 218.6 mmol), Pd(OAc).sub.2 (2.9 g, 13.1 mmol), SPhos (9.0 g, 21.9 mmol) and K.sub.3PO.sub.4 (232.0 g, 1.1 mol). A mixture of deaerated toluene/water (2:1, 1.4 L) was added and the reaction mixture was heated to reflux under an argon atmosphere for 30 h. After cooling down to room temperature, the crude product was isolated by suction filtration and washed with water (0.7 L) and toluene. Further purification was achieved by acetone Soxhlet extraction to yield 55.3 g (78%) of a yellow solid after drying.

Step 2

5′-(pyridin-3-yl)-[1,1′: 4′,1″-terphenyl]-2′-yl trifluoromethanesulfonate

[0380] A flask was flushed with argon and charged with 5′-(pyridin-3-yl)-[1,1′: 4′,1″-terphenyl]-2′-ol (59.5 g, 184.0 mmol), pyridine (anhydrous, 22.2 mL, 275.9 mmol) and DCM (anhydrous, 1.2 L). The mixture was cooled to 0° C. and Tf.sub.2O (46.4 mL, 275.9 mmol) was added. After stirring under an argon atmosphere for 45 min, the reaction mixture was quenched with water (0.5 L). The crude product was extracted with a DCM/aqueous K.sub.2CO.sub.3 mixture, then the organic phase was concentrated under reduced pressure to 0.5 L, and filtered through a silica gel pad which was rinsed with DCM/EtOAc (10:1). The solvent was removed under reduced pressure, and the product was stirred overnight in petroleum ether/DCM (65:3, 680 mL) and filtered to yield 51.2 g (61%) of a white solid after drying.

[0381] APCI-MS: m/z=456 ([M+H].sup.+).

Preparation of Exemplary Compounds

2-(dibenzo[b,d]furan-3-yl)-4-phenyl-6-(5′-phenyl-4′-(pyridin-3-yl)-[1,1′:2′1″-terphenyl]-4-yl)-1,3,5-triazine (E1)

[0382] ##STR00038##

[0383] A flask was flushed with nitrogen and charged with 3-(5′-bromo-[1,1′: 4′,1″-terphenyl]-2′-yl)pyridine (7.4 g, 19.3 mmol), 2-(dibenzo[b,d]furan-3-yl)-4-phenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (10.0 g, 19.1 mmol), Pd(dppf)Cl.sub.2 (0.3 g, 0.4 mmol), and K.sub.2CO.sub.3 (5.3 g, 38.1 mmol). A mixture of deaerated THF/water (4:1, 125 mL) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (until pH neutral) and methanol (2×50 mL). The crude product was then dissolved in chloroform (1.7 L) at reflux and filtered through a silica gel pad. Impurities were flushed with additional chloroform, then the product was rinsed with chloroform/methanol (98:2, 3 L). The filtrate was concentrated under reduced pressure to 200 mL and 100 mL n-hexane was added. The precipitate was collected by suction filtration to yield 11.8 g (87%) of a white solid after drying. Final purification was achieved by sublimation.

[0384] ESI-MS: m/z=705 ([M+H].sup.+).

2,4-diphenyl-6-(5′-phenyl-4′-(pyridin-4-yl)-[1,1′:2′,1″-terphenyl]-4-yl)-1,3,5-triazine (E2)

[0385] ##STR00039##

[0386] A flask was flushed with nitrogen and charged with 4-(5′-bromo-[1,1′:4′,1″-terphenyl]-2′-yl)pyridine (13.0 g, 33.7 mmol), 2,4-diphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (19.2 g, 44.0 mmol), Pd(PPh.sub.3).sub.4 (0.8 g, 0.7 mmol), and K.sub.2CO.sub.3 (9.3 g, 67.5 mmol). A mixture of deaerated 1,4-dioxane/water (4:1, 170 mL) was added and the reaction mixture was heated to 75° C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (until pH neutral) and methanol (300 mL). The crude product was then dissolved in chloroform (1.5 L) at reflux and filtered through a silica gel pad. After rinsing with additional chloroform/methanol (98:2), the filtrate was concentrated under reduced pressure to 200 mL. The precipitate was collected by suction filtration, washed with n-hexane (500 mL) and further purified by recrystallization from chloroform to yield 12.0 g (58%) of a white solid after drying. Final purification was achieved by sublimation.

[0387] ESI-MS: m/z=615 ([M+H].sup.+).

2-(naphthalen-2-yl)-4-phenyl-6-(5′-phenyl-4′-(pyridin-3-yl)-[1,1′: 2′,1″-terphenyl]-4-yl)-1,3,5-triazine (E3)

[0388] ##STR00040##

[0389] A flask was flushed with nitrogen and charged with 3-(5′-bromo-[1,1′: 4′,1″-terphenyl]-2′-yl)pyridine (10.0 g, 25.9 mmol), 2-(naphthalen-2-yl)-4-phenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (12.6 g, 25.9 mmol), Pd(dppf)Cl.sub.2 (0.4 g, 0.5 mmol), and K.sub.2CO.sub.3 (7.1 g, 51.7 mmol). A mixture of deaerated 1,4-dioxane/water (4:1, 125 mL) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (until pH neutral) and methanol (400 mL). The crude product was then dissolved in chlorobenzene (800 mL) at reflux and filtered through a silica gel pad. Impurities were flushed with additional chlorobenzene, then the product was rinsed with chloroform/methanol (98:2, 2 L) and the filtrate was concentrated under reduced pressure to 200 mL. The precipitate was collected by suction filtration, washed with n-hexane (500 mL) and further purified by recrystallization from chloroform to yield 9.0 g (52%) of a white solid after drying. Final purification was achieved by sublimation.

[0390] ESI-MS: m/z=665 ([M+H].sup.+).

2,4-diphenyl-6-(5′-phenyl-4′-(pyridin-3-yl)-[1,1′:2′,1″-terphenyl]-4-yl)-1,3,5-triazine (E4)

[0391] ##STR00041##

[0392] A flask was flushed with nitrogen and charged with 3-(5′-bromo-[1,1′: 4′,1″-terphenyl]-2′-yl)pyridine (10.0 g, 25.9 mmol), 2,4-diphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,3,5-triazine (12.4 g, 28.5 mmol), Pd(dppf)Cl.sub.2 (0.2 g, 0.3 mmol), and K.sub.2CO.sub.3 (7.2 g, 51.8 mmol). A mixture of deaerated THF/water (4:1, 130 mL) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (200 ml), methanol (50 mL) and n-hexane (50 mL). The crude product was then dissolved in chlorobenzene (600 mL) at reflux and filtered through a silica gel pad. Impurities were flushed with additional hot chlorobenzene (1.5 L), then the product was rinsed with chlorobenzene/methanol (95:5, 3 L) and the filtrate was concentrated under reduced pressure. The precipitate was collected by suction filtration to yield 3.9 g (25%) of a white solid after drying.

[0393] ESI-MS: m/z=615 ([M+H]+).

Device

[0394] The inventive compounds E1 to E3 were tested as electron transport material (ETM) in a model top emitting blue OLED and compared with state-of-art compound C1 as electron transport material (ETM).

Inventive ETM Examples “E1 to E3”

[0395] ##STR00042##

Comparative ETM Example “C1”

[0396] ##STR00043##

[0397] C1 (disclosed as exemplary compound D2 in WO2019/121672).

Further Supporting Materials for Preparation of a Device

[0398] F1 is

##STR00044## [0399] N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, CAS 1242056-42-3;

[0400] F2 is

##STR00045## [0401] N-(4-(dibenzo[b,d]furan-4-yl)phenyl)-N-(4-(9-phenyl-9H-fluoren-9-yl)phenyl)-[1,1′-biphenyl]-4-amine, CAS 1824678-59-2;

[0402] F3 is

##STR00046## [0403] 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine, CAS 1955543-57-3;

[0404] LiQ is lithium 8-hydroxyquinolinolate, H09 is a commercial blue emitter host and BD200 is a commercial blue emitter, both supplied by SFC, Korea;

[0405] PD2 is

##STR00047## [0406] 4,4′,4″-((1E,1′E,1″E)-cyclopropane-1,2,3-triylidenetris(cyanomethanylylidene))tris(2,3,5,6-tetrafluorobenzonitrile), CAS 1224447-88-4.

Standard Procedures

OLED Preparation

[0407] On a commercially available substrate provided with an anode, organic layers were deposited by vacuum thermal evaporation (VTE) in the desired order and with thicknesses/composition which can be adjusted and controlled by monitoring the deposition rate and adjusting the temperature of vaporization source for each respective component. Metallic cathodes are prepared by VTE, in case of top-emitting devices, an additional organic light outcoupling may be provided on top of the cathode. Finally, the complete OLED stack may be protected from ambient conditions by suitable encapsulation, e.g. with a glass slide, and the formed cavity may comprise a getter material for moisture and/or oxygen absorption.

[0408] To assess the performance of the inventive and comparative examples, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing a voltage in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m.sup.2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.

[0409] Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm.sup.2, using a Keithley 2400 sourcemeter, and recorded in hours.

[0410] The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.

Voltage Stability

[0411] OLEDs are driven by constant current circuits. Those circuits can supply a constant current over a given voltage range. The wider the voltage range, the wider the power losses of such devices. Hence, the change of driving voltage upon driving needs to be minimized.

[0412] The driving voltage of an OLED is temperature dependent. Therefore, voltage stability needs to be judged in thermal equilibrium. Thermal equilibrium is reached after one hour of driving.

[0413] Voltage stability is measured by taking the difference of the driving voltage after 50 hours and after 1 hour driving at a constant current density. Here, a current density of 30 mA/cm.sup.2 is used. Measurements are done at room temperature.

dU [V]=U(50 h,30 mA/cm.sup.2)−U(1 h,30 mA/cm.sup.2)

Device Structure

[0414] The model device for testing the inventive compounds was a blue top emitting OLED with a structure schematically shown in Table 1.

TABLE-US-00001 TABLE 1 Layer Material d [nm] Anode Ag 100 HIL F1:PD2 (92:8 v/v) 10 HTL F1 128 EBL F2 5 EML H09:BD200 (97:3 v/v) 20 HBL F3 5 ETL ETM:LiQ (50:50 v/v) 31 EIL Yb 2 Cathode Ag:Mg (90:10) 11

Test Results

[0415] Test result with respect to the lifetime (LT) and the voltage stability (dV) observed for the model device in case that E1, E2, E3 and C1 were used as ETM, respectively, are shown in Table 2

TABLE-US-00002 TABLE 2 ETM LT (h) dV (V) C1 56 0.033 E1 80 0.006 E2 72 0.004 E3 74 0.005

[0416] As it can be seen from Table 2, if the inventive compounds E1 to E3 were used as ETM, both lifetime as well as voltage stability of the tested device was significantly improved in comparison to the comparative compound C1.