Compound and an organic semiconducting layer, an organic electronic device, a display device and a lighting device comprising the same

Abstract

The present invention relates to compound having the following Formula (I) a semiconducting layer comprising this compound, an organic electronic device comprising said organic semiconducting layer, as well as to a device comprising the organic electronic device.

##STR00001##

Claims

1. Compound having the general Formula (I) ##STR00095## wherein A is substituted or unsubstituted C.sub.3 to C.sub.14 heteroarylene comprising at least one six-membered ring, the six-membered ring comprising at least two N-atoms, wherein the one or more substituents, if present in the group A, are independently selected from the group consisting of C.sub.1 to C.sub.7 alkyl, C.sub.1 to C.sub.7 alkoxy, partially or perdeuterated C.sub.1 to C.sub.7 alkyl, partially or perdeuterated C.sub.1 to C.sub.7 alkoxy, partially or perfluorinated C.sub.1 to C.sub.7 alkyl, partially or perfluorinated C.sub.1 to C.sub.7 alkoxy, D, F and CN; R.sup.1, R.sup.2, Q-Ar.sup.1 and Z-Y are bound to C-atoms of A; Q-Ar.sup.1 and Z-Y are bound to C-atoms of the six-membered ring comprising at least two N-atoms of A; R.sup.1 is selected from the group consisting of H, substituted or unsubstituted C.sub.6 to C.sub.18 aryl, and substituted or unsubstituted C.sub.2 to C.sub.18 heteroaryl, wherein the one or more substituents, if present in the group R.sup.1, are independently selected from the group consisting of C.sub.1 to C.sub.7 alkyl, C.sub.1 to C.sub.7 alkoxy, partially or perdeuterated C.sub.1 to C.sub.7 alkyl, partially or perdeuterated C.sub.1 to C.sub.7 alkoxy, partially or perfluorinated C.sub.1 to C.sub.7 alkyl, partially or perfluorinated C.sub.1 to C.sub.7 alkoxy, D, F and CN; R.sup.2 is selected from the group consisting of H, substituted or unsubstituted C.sub.6 to C.sub.18 aryl, and substituted or unsubstituted C.sub.2 to C.sub.18 heteroaryl, wherein the one or more substituents, if present in the group R.sup.2, are independently selected from the group consisting of C.sub.1 to C.sub.7 alkyl, C.sub.1 to C.sub.7 alkoxy, partially or perdeuterated C.sub.1 to C.sub.7 alkyl, partially or perdeuterated C.sub.1 to C.sub.7 alkoxy, partially or perfluorinated C.sub.1 to C.sub.7 alkyl, partially or perfluorinated C.sub.1 to C.sub.7 alkoxy, D, F and CN; or is absent in case that A is C.sub.3 heteroarylene; Q represents a single bond between A and Ar.sup.1 or is a group having the Formula (II) or (III) ##STR00096## in Formulas (II) and (III) the * symbols represent the positions for binding to A and Ar.sup.1, respectively; X is H, C.sub.1 to C.sub.7 alkyl or is represented by the general formula (IV) ##STR00097## in formula (IV) at least two of Ar.sup.2 to Ar.sup.6 are in ortho-position to each other; and/or at least one of Ar.sup.2 and Ar.sup.6 is in ortho-position to the *-position; or in case that a to e are o at the same time, X is in ortho-position to Ar.sup.1; Ar.sup.1 is selected from the group consisting of substituted or unsubstituted C.sub.6 to C.sub.60 aryl, CN-substituted phenyl and substituted or unsubstituted N-containing C.sub.3 to C.sub.20 heteroaryl, wherein the one or more substituents, if present in the group Ar.sup.1, are independently selected from the group consisting of C.sub.1 to C.sub.7 alkyl, C.sub.1 to C.sub.7 alkoxy, partially or perdeuterated C.sub.1 to C.sub.7 alkyl, partially or perdeuterated C.sub.1 to C.sub.7 alkoxy, partially or perfluorinated C.sub.1 to C.sub.7 alkyl, partially or perfluorinated C.sub.1 to C.sub.7 alkoxy, D, F and CN; Ar.sup.1 is different from A; Z represents a single bond between A and Y or a group having the Formula (V) or (VI) ##STR00098## in Formulas (V) and (VI) the * symbols represent the positions for binding to A and Y, respectively; Y is H, C.sub.1 to C.sub.7 alkyl or is represented by the general formula (VII) ##STR00099## in formula (VII) at least two of Ar.sup.7 to Ar.sup.11 are in ortho-position to each other; and/or at least one of Ar.sup.7 and Ar.sup.11 is in ortho-position to the *-position; X and Y cannot be H and/or C.sub.1 to C.sub.7 alkyl at the same time; Q and Y may be substituted with one or more substituents selected from the group consisting of C.sub.1 to C.sub.7 alkyl, C.sub.1 to C.sub.7 alkoxy, partially or perdeuterated C.sub.1 to C.sub.7 alkyl, partially or perdeuterated C.sub.1 to C.sub.7 alkoxy, partially or perfluorinated C.sub.1 to C.sub.7 alkyl, partially or perfluorinated C.sub.1 to C.sub.7 alkoxy, D, F and CN; a to k are independently 0 or 1, provided that 2?a+b+c+d+e+f+g+h+i+k?5; Ar.sup.2 to Ar.sup.11 are independently selected from the group consisting of substituted or unsubstituted C.sub.6 to C.sub.12 aryl and C.sub.4 to C.sub.10 heterorayl, wherein the one or more substituents, if present in one or more of the groups Ar.sup.2 to Ar.sup.11, are independently selected from the group consisting of C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, partially or perfluorinated C.sub.1 to C.sub.6 alkyl, partially or perfluorinated C.sub.1 to C.sub.6 alkoxy, D, F and CN; neither Formula (IV) nor Formula (VII) comprises condensed aromatic rings; and a compound having the following formula is excluded ##STR00100##

2. Compound according to claim 1, wherein the 6-membered ring of A comprises 2 to 3 N-atoms.

3. Compound according to claim 1, wherein Q represents a group having the Formula (II) or (III) and/or Z represents a group having the Formula (V) or (VI).

4. Compound according to claim 1, wherein Q represents a group having the Formula (II) and/or Z represents a group having the Formula (V).

5. Compound according to claim 1, wherein Q represents a group having the Formula (II) and Z represents a group having the Formula (V).

6. Compound according to claim 1, wherein A is selected from the group consisting of triazinylene, pyrimidinylene, pyrazinylene, quinoxalinyl, quinazolinylene, and benzoquinazolinylene.

7. Compound according to claim 1, wherein Ar.sup.1 is selected from the group consisting of phenyl, naphthyl, phenanthrene, pyridinyl, quinolinyl, isoquinolinyl, azaphenanthrenyl, carbazolyl, benzo-nitrilyl, ##STR00101##

8. Compound according to claim 1, wherein the total number of aromatic rings comprised in the compound of Formula (I) is from 7 to 14.

9. Organic semiconducting layer comprising the compound of Formula 1 according to claim 1.

10. Organic electronic device comprising the organic semiconducting layer according to claim 9, wherein the organic semiconducting layer is a charge generation layer.

11. Organic electronic device comprising the organic semiconducting layer according to claim 9, wherein the organic semiconducting layer is an electron transport layer and the electron transport layer comprises one or more additives, wherein the additive may be an n-type dopant.

12. Organic electronic device comprising the organic semiconducting layer according to claim 9, wherein the organic semiconducting layer is an electron transport layer and the electron transport layer consists of a compound of Formula 1.

13. Display device comprising the organic electronic device according to claim 10.

14. Lighting device comprising the organic electronic device according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0294] 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:

[0295] FIG. 1 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention;

[0296] FIG. 2 is a schematic sectional view of an OLED, according to an exemplary embodiment of the present invention.

[0297] 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

[0298] 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.

[0299] 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.

[0300] 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.

[0301] Instead of a single electron transport layer 160, optionally an electron transport layer stack (ETL) can be used.

[0302] 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.

[0303] Referring to FIG. 2, the OLED 100 includes a substrate 110, 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.

[0304] Preferably, the organic semiconducting layer comprising a compound of Formula (I) may be an ETL.

[0305] 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 100 of FIG. 3 further comprises a charge generation layer (CGL) and a second emission layer (151).

[0306] Referring to FIG. 3, the OLED 200 includes a substrate 110, 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) 150, 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 (En) 161, a second electron injection layer (EIL) 181 and a cathode 190.

[0307] Preferably, the organic semiconducting layer comprising a compound of Formula (I) may be the first ETL, n-type CGL and/or second ETL.

[0308] 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.

[0309] Hereinafter, one or more exemplary embodiments of the present invention will be described in detail with, reference to the following examples. However, these examples are not intended to limit the purpose and scope of the one or more exemplary embodiments of the present invention.

Experimental Data

Melting Point

[0310] The melting point (mp) is determined as peak temperatures from the DSC curves of the above TGA-DSC measurement or from separate DSC measurements (Mettler Toledo DSC822e, heating of samples from room temperature to completeness of melting with heating rate 10 K/min under a stream of pure nitrogen. Sample amounts of 4 to 6 mg are placed in a 40 ?L Mettler Toledo aluminum pan with lid, a <1 mm hole is pierced into the lid).

Glass Transition Temperature

[0311] The glass transition temperature (Tg) is measured under nitrogen and using a heating rate of 10 K per min in a Mettler Toledo DSC 822e differential scanning calorimeter as described in DIN EN ISO 11357, published in March 2010.

Rate Onset Temperature

[0312] The rate onset temperature (TRO) is determined by loading 100 mg compound into a VTE source. As VIE source a point source for organic materials may be used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10.sup.?5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the compound is detected with a QCM detector which detects deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in ?ngstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTE source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.

[0313] To achieve good control over the evaporation rate of an organic compound, the rate onset temperature may be in the range of 200 to 255? C. If the rate onset temperature is below 200? C. the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is above 255? C. the evaporation rate may be too low which may result in low tact time and decomposition of the organic compound in VTE source may occur due to prolonged exposure to elevated temperatures.

[0314] The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.

Reduction Potential

[0315] The reduction potential is determined by cyclic voltammetry with potenioststic device Metrohm PGSTAT30 and software Metrohm Autolab GPES at room temperature. The redox potentials given at particular compounds were measured in an argon de-aerated, dry 0.1M THF solution of the tested substance, under argon atmosphere, with 0.1M tetrabutylammonium hexafluorophosphate supporting electrolyte, between platinum working electrodes and with an Ag/AgCl pseudo-standard electrode (Metrohm Silver rod electrode), consisting of a silver wire covered by silver chloride and immersed directly in the measured solution, with the scan rate 100 mV/s. The first run was done in the broadest range of the potential set on the working electrodes, and the range was then adjusted within subsequent runs appropriately. The final three runs were done with the addition of ferrocene (in 0.1 M concentration) as the standard. The average of potentials corresponding to cathodic and anodic peak of the studied compound, after subtraction of the average of cathodic and anodic potentials observed for the standard Fc.sup.+/Fc redox couple, afforded finally the values reported above. All studied compounds as well as the reported comparative compounds showed well-defined reversible electrochemical behaviour.

Dipole Moment

[0316] The dipole moment |{right arrow over (?)} | of a molecule containing N atoms is given by:

[00001]$\stackrel{.fwdarw.}{?}=\underset{i}{\overset{N}{.Math.}}{q}_i\stackrel{.fwdarw.}{r_{\mathrm{.Math.}}}$$.Math.\stackrel{.fwdarw.}{?}.Math.=\sqrt{{?}_x^2+{?}_y^2+{?}_z^2}$

[0317] where q.sub.i and {right arrow over (r)}.sub.i are the partial charge and position of atom i in the molecule.

[0318] The dipole moment is determined by a semi-empirical molecular orbital method.

[0319] The geometries of the molecular structures are optimized using the hybrid functional B3LYP with the 6-31G* basis set in the gas phase as implemented in the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). If more than one conformation is viable, the conformation with the lowest total energy is selected to determine the bond lengths of the molecules.

Calculated HOMO and LUMO

[0320] The HOMO and LUMO are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected. Measurement of OLED Performance

[0321] To assess the performance of the OLED devices 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/cm.sup.2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.

[0322] 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.

[0323] 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.

[0324] The increase in operating voltage ?U is used as a measure of the operating voltage stability of the device. This increase is determined during the LT measurement and by subtracting the operating voltage at the start of operation of the device from the operating voltage after 50 hours.

?U=[U(50 h)?U(0 h)]

The smaller the Value of ?U the Better is the Operating Voltage Stability.

Synthesis Procedures

[0325] ##STR00071## ##STR00072##

[0326] Compound (1) was synthesized following a standard Suzuki-Miyaura procedure (reference KR2017093023A)

2-chloro-4-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-6-phenyl-1,3,5-triazine (3)

[0327] A flask was flushed with nitrogen and charged with 2-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1) (100 g, 196.7 mmol), 2,4-dichloro-6-phenyl-1,3,5-triazine (2) (68.0 g, 295 mmol), Pd(dppf)Cl.sub.2 (7.2 g, 9.8 mmol), and K.sub.2CO.sub.3 (67.9 g, 491.7 mmol). A mixture of deaerated Toluene/THF/water (1:1:1, 1200 mL) was added and the reaction mixture was heated to 65? C. under a nitrogen atmosphere overnight. Solvent was partially evaporated under reduced pressure and the resulting precipitate was isolated by suction filtration and washed thoroughly with water (600 mL), methanol (20 mL) and hexane (20 mL). The crude product was dissolved in toluene (600 mL) and filtered over a pad of silicagel. After rinsing with additional toluene, solvents were partially removed and the suspension was left stirring overnight. Precipitate was filtered, washed with hexane, recrystallized in toluene two times, and dried under vacuum to yield 36.5 g (32%) of white solid after drying. HPLC: 99%.

##STR00073##

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

[0328] A flask was

##STR00074##

flushed with nitrogen and charged with 2-chloro-4-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-6-phenyl-1,3,5-triazine (3) (15.5 g, 26.4 mmol), 3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine (4) (7.4 g, 26.4 mmol), Pd(dppf)Cl.sub.2 (0.4 g, 0.5 mmol), and K.sub.2CO.sub.3 (7.3 g, 52.8 mmol). A mixture of deaerated THF/water (4:1, 132 mL) was added and the reaction mixture was heated to 75? C. under a nitrogen atmosphere overnight. Solvent was evaporated under reduced pressure and the compound (embedded in silicagel) was purified by silicagel column chromatography, using a gradient eluent (dichloromethane/hexane 1:2 to dichloromethane). Solvent was evaporated under reduced pressure and the resulting solid was triturated in methanol to yield 6.2 g (32%) of white solid after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.97%, m/z=691 ([M+H].sup.+).

##STR00075## ##STR00076##

4-chloro-6-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-2-phenylpyrimidine (6)

##STR00077##

[0329] A flask was flushed with nitrogen and charged with 2-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1) (100 g, 196.7 mmol), 4,6-dichloro-2-phenylpyrimidine (5) (66.4 g, 295.0 mmol), Pd(dppf)Cl.sub.2 (7.2 g, 9.8 mmol), and K.sub.2CO.sub.3 (67.9 g, 491.7 mmol). A mixture of deaerated THF/Toluene/water (1:1:1, 1200 mL) was added and the reaction mixture was heated to 60? C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed thoroughly with water (3 L), methanol (2?70 mL) and hexane (2?50 mL). The crude product was then triturated first in Toluene/THF 1:1 (600 mL), and then in toluene (500 mL) to yield 71.2 g (60%) of white solid after drying. HPLC: 99%.

4-(2,6-diphenyl-[1,1:4, 1-terphenyl]-4-yl)-2-phenyl-6-(3-(pyridin-3-yl)phenyl)pyrimidine (M-2)

[0330] A flask was flushed with nitrogen and charged with 4-chloro-6-(2,6-diphenyl-[1,1:4,1-terphenyl]-4-yl)-2-phenylpyrimidine (6) (20 g, 35.0 mmol), 3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine (4) (10.8 g, 38.5 mmol), Pd(PPh.sub.3).sub.4 (0.8 g, 0.7 mmol), and K.sub.2CO.sub.3 (9.7 g, 70.0 mmol). A mixture of dioxane/water (280:35 mL) was added and the reaction mixture was heated to 75? C. under a nitrogen atmosphere over two days. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed thoroughly with water (600 mL), methanol (20 mL) and hexane (20 mL). The crude product was dissolved in dichloromethane (1.6 L) and filtered over a pad of silicagel. After rinsing with additional dichloromethane (2 L) and dichloromethane:methanol (100:5), solvents were partially removed under reduced pressure and hexane (300 mL) was added to induce precipitation. Precipitate was filtered, washed with hexane and dried under vacuum to yield 16 g (66%) of white solid after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 100%, m/z=690 ([M+H].sup.+).

##STR00078##

2,4-diphenyl-6-(4-phenyl-5-(pyridin-3-yl)-[1,1:3,1-terphenyl]-3-yl)-1,3,5-triazine (M3)

[0331] A flask was flushed with nitrogen and charged with 2-(3-chloro-5-(pyridin-3-yl)phenyl)-4,6-diphenyl-1,3,5-triazine (7) (5.0 g, 11.9 mmol), 2-([1,1:2,1-terphenyl]-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (8) (5.5 g, 15.4 mmol), chloro(crotyl)(2-dicyclohexylphosphino-2,6-dimethoxybiphenyl)palladium(II) (0.14 g, 0.2 mmol), and K.sub.3PO.sub.4 (5.0 g, 23.8 mmol). A mixture of dioxane/water (4:1, 68 mL) was added and the reaction mixture was heated to 45? C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed thoroughly with water (400 mL), methanol (20 mL) and hexane (20 mL). The crude product was dissolved in dichloromethane : hexane (1:1, 800 mL) and filtered over a pad of silicagel. After rinsing with additional dichloromethane/hexane (1:1, 800 mL) and dichloromethane (500 mL), solvents were partially removed under reduced pressure and hexane (300 mL) was added to induce precipitation. Precipitate was filtered, washed with hexane and dried under vacuum to yield 5.8 g (80%) of white solid after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.9%, m/z=615 ([M+H].sup.+).

##STR00079##

##STR00080##

2-chloro-4-phenyl-6-(3,4,5-triphenyl-[1,1:2,1-terphenyl]-3-yl)-1,3,5-triazine (10)

##STR00081##

A flask was flushed with nitrogen and charged with 4,4,5,5-tetrarnethyl-2-(3,4,5-triphenyl-[1,1:2,1-terphenyl]-3-yl)-1,3,2-dioxaborolane (9) (60.0 g, 102.6 mmol), 2,4-dichloro-6-phenyl-1,3,5-triazine (2) (27.3 g, 120.8 mmol), Pd(dppf)Cl.sub.2 (4.4 g, 6.0 mmol), and K.sub.2CO.sub.3 (41.7 g, 301.9 mmol). A mixture of Toluene/THF/water (1:1:1, 1050 mL) was added and the reaction mixture was heated to 65? C. under a nitrogen atmosphere overnight. After cooling down to room temperature, the aqueous phase was decanted, and the organic phase was washed with water (2?250 mL), dried over Mg.sub.2SO.sub.4. Drying agent was filtered off and solvents were removed under reduced pressure. Residue was dissolved in dichloromethane and filtered over a silicagel pad. After rinsing with hexane/ethylacetate (20:1), solvents were removed under reduced pressure to yield 24 g (36%) of solid after drying. HPLC: 99%.
2-phenyl-4-(3-(pyridin-3-yl)phenyl)-6-(3,4, 5-triphenyl-[1,1:2, 1-terphenyl]-3-yl)-1,3,5-triazine (M-4)

##STR00082##

A flask was flushed with nitrogen and charged with 2-chloro-4-phenyl-6-(3,4,5-triphenyl-[1,1:2,1-terphenyl]-3-yl)-1,3,5-trazine (10) (11.9 g, 18.4 mmol), 3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine (4), (5.7 g, 20.2 mmol), Pd(dppf)Cl.sub.2 (0.3 g, 0.37 mmol), and K.sub.2CO.sub.3 (5.1 g, 36.8 mmol). A mixture of THF/water (4:1, 125 mL) was added and the reaction re was heated to 75? C. under a nitrogen atmosphere for two hours. After cooling down to room temperature, solvents were removed under reduced pressure. The crude reaction mixture was dissolved in dichloromethane (400 mL), washed with water (3?300 mL), dried over Mg.sub.2SO.sub.4 and directly filtered over a fluorisil pad. After rinsing with additional dichloromethane/methanol (100:2, 2.5 L), solvents were partially removed under reduced pressure and isopropanol (400 mL) was added to induce precipitation. Precipitate was filtered and washed with isopropanol. Solid was dissolved in toluene (40 mL), methanol (200 mL) was added to induce precipitation. Precipitate was filtered, washed with methanol and dried under vacuum to yield 4.4 g (32%) of light pink solid after drying. Final purification was achieved by sublimation. HPLC/ESI-MS: 99.6%, m/z=767 ([M+H].sup.+).

General Procedure for Fabrication of OLEDs

[0332] For the top emission OLED devices of example-1 to example-3 and of the comparative example a substrate with dimensions of 150 mm?150 mm?0.7 mm was ultrasonically cleaned with a 2% aquatic solution of Deconex FPD 211 for 7 minutes and then with pure water for 5 minutes, and dried for 15 minutes in a spin rinse dryer. Subsequently, Ag was deposited as anode at a pressure of 10-5 to 10-7 mbar.

[0333] Then, HT-1 and D-1 were vacuum co-deposited on the anode to form a HIL. Then, HT-1 was vacuum deposited on the HIL, to form an HTL. Then, HT-2 was vacuum deposited on the HTL to form an electron blocking layer (EBL).

[0334] Afterwards the emission layer was formed on the EBL by co-deposition of HOST-1 and EMITTER-1.

[0335] Then, the ET-1 was vacuum deposited onto the emission layer to form the hole blocking layer (HBL). Then, the electron transport layer was formed on the hole blocking layer by co-depositing a compound of Formula (I) and LiQ in a wt % ratio of 1:1 for example-1 to example-3. For the comparative example the electron transport layer was formed on the hole blocking layer by co-depositing the compound comparative-1 and LiQ in a wt % ratio of 1:1.

[0336] Then, the electron injection layer is formed on the electron transporting layer by depositing Yb.

[0337] Ag:Mg is then evaporated at a rate of 0.01 to 1 ?/s at 10-7 mbar to form a cathode.

[0338] A cap layer of HT-1 is formed on the cathode.

[0339] The details of the layer stack in the top emission OLED devices are given below. A slash / separates individual layers. Layer thicknesses are given in squared brackets [. . . ], mixing ratios in wt % given in round brackets ( . . . ):

Layer Stack Details:

[0340] Ag [100 nm]/HT-1:D-1 (wt % 92:8) [10 nm]/HT-1 [118 nm]/HT-2 [5 nm]/H09:BD200 (wt % 97:3) [20 nm]/ET-1 [5 nm]/Compound of Formula (I): LiQ (wt % 1:1) [31 nm]/Yb [2 nm]/Ag:Mg (wt % 90:10) [11 nm]/HT-1 [70 nm]

Technical Effect of the Invention

[0341] The OLED devices according to the invention show improved efficiency and lifetime at comparable voltage when using the compounds of Formula (I) in an electron transport layer instead of the comparative compound. The voltage stability is also improved.

List of Compounds Used

[0342]

TABLE-US-00001 IUPAC name Reference HT-1 N-([1,1-biphenyl]-4-yl)- US2016322581 9,9-dimethyl-N-(4-(9- phenyl-9H-carbazol-3- yl)phenyl)-9H-fluoren-2- amine [CAS 1242056-42-3] HT-2 N-(4-(dibenzo[b,d]furan- WO2015174640 4-yl)phenyl)-N-(4-(9- phenyl-9H-fluoren-9- yl)phenyl)-[1,1-biphenyl]-4- amine [CAS 1824678-59-2] D-1 4,4,4-((1E,1E,1E)- US2008265216 cyclopropane-1,2,3- triylidenetris(cyanome- thanylylidene))tris(2,3,5,6- tetrafluorobenzonitrile) [CAS 1224447-88-4] HOST-1 H09 (Fluorescent-blue Commercially host material) available from Sun Fine Chemicals, Inc, S. Korea EMITTER-1 BD200 (Fluorescent-blue Commercially emitter material) available from Sun Fine Chemicals, Inc, S. Korea ET-1 2-(3-(9,9-dimethyl- WO2016105141 9H-fluoren-2-yl)-[1,1- biphenyl]-3-yl)-4,6- diphenyl-1,3,5-triazine [CAS 1955543-57-3] Comparative- 2-(dibenzo[b,d]furan- 1 3-yl)-4-(2,6-diphenyl- [1,1:4,1-terphenyl]-4- yl)-6-phenyl-1,3,5-triazine LiQ 8-Hydroxyquinolinolato-lithium WO2013079217 [CAS 850918-68-2]

TABLE-US-00002 TABLE 1 Properties of compounds M-1 to M-4 of Formula (I) and of comparative compound Comparative-1. mp Tg T.sub.RO [?C] [?C] [?C] Comparative-1 [00083] 276 158 242 M-1 [00084] 139 252 M-2 [00085] 258 133 259 M-3 [00086] 242 100 240 M-4 [00087] 139

TABLE-US-00003 TABLE 2 Dipole moment, HOMO and LUMO levels of compound comparative-1 and compounds of Formula (I) M-1 to M-4, simulated by DFT (B3LYP_Gaussian / 6-31G*, gas phase) Dipole moment HOMO LUMO [Debye] [eV] [eV] Comparative-1 0.85 ?5.82 ?1.93 M-1 2.69 ?5.86 ?1.92 M-2 3.22 ?5.84 ?1.77 M-3 2.46 ?5.87 ?1.92 M-4 1.86 ?5.86 ?1.87

TABLE-US-00004 TABLE 3 Performance of an organic electroluminescent device comprising the compounds of Formula (I) or the comparative compound-1 as a matrix compound in the electron transport layer. CIE 1931 y = 0.045 Operating voltage U CEff at LT97 at ?U at at 10 30 30 OLED 10 mA/ mA/ mA/ device Matrix mA/cm.sup.2 cm.sup.2 cm.sup.2 cm.sup.2 examples compound Additive (V) (cd/A) (hours) (V) Comparative Compar- LiQ 3.56 6.91 37 0.0605 example ative-1 Example-1 M-1 LiQ 3.53 7.24 51 0.0105 Example-2 M-2 LiQ 3.67 7.86 48 0.0035 Example-3 M-3 LiQ 3.68 7.25 82 0.0025

TABLE-US-00005 TABLE 4 Calculated LUMO levels, Examples of groups A with the bonding simulated by DFT positions of the 6-membered ring comprising at (B.sub.3LYP_Gaussian/6-31G*, least two N-atoms occupied by phenyl rings. gas phase) in [eV] [00088] ?1.87 [00089] ?1.77 [00090] ?1.57 [00091] ?1.77 [00092] ?1.80 [00093] ?1.72 [00094] ?1.90

[0343] The features disclosed in the foregoing description and in the dependent claims may, both separately and in any combination thereof, be material for realizing the aspects of the disclosure made in the independent claims, in diverse forms thereof.