COMPOUNDS FOR ELECTRONIC DEVICES

Abstract

The present application relates to phenanthrene compounds of a particular formula (I), their use in electronic devices, electronic devices comprising such phenanthrene compounds, as well as processes for the synthesis of such phenanthrene compounds.

Claims

1-16. (canceled)

17. A compound of formula (I): ##STR00105## wherein the phenanthrene group is optionally substituted by radicals R.sup.3 in the free positions, and the anthracene group is optionally substituted by radicals R.sup.4 in the free positions; Ar.sup.1 is selected from the group consisting of aryl groups having 6 to 10 aromatic ring atoms, which are optionally substituted by radicals R.sup.1, and heteroaryl groups having 5 to 18 aromatic ring atoms, which are optionally substituted by radicals R.sup.1; Ar.sup.2 is selected from the group consisting of phenyl, which is optionally substituted by radicals R.sup.2, 1-naphthyl, which is optionally substituted by radicals R.sup.2, aromatic ring systems having 13 to 30 aromatic ring atoms, which are optionally substituted by radicals R.sup.2, and heteroaromatic ring systems having 5 to 30 aromatic ring atoms, which are optionally substituted by radicals R.sup.2; R.sup.1, R.sup.2, and R.sup.4 is selected, identically or differently on each occurrence, from the group consisting of H, D, F, C(?O)R.sup.5, CN, Si(R.sup.5).sub.3, N(R.sup.5).sub.2, P(?O)(R.sup.5)2, OR.sup.5, S(?O)R.sup.5, S(?O).sub.2R.sup.5, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherein two or more radicals R.sup.1, R.sup.2, or R.sup.4 are optionally connected to each other so as to define a ring; wherein the alkyl, alkoxy, alkenyl, and alkynyl groups and the aromatic and heteroaromatic ring systems are in each case optionally substituted by one or more radicals R.sup.5, and wherein one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are in each case optionally replaced by R.sup.5C?CR.sup.5, C?C, Si(R.sup.5).sub.2, C?O, C?NR.sup.5, C(?O)O, C(?O)NR.sup.5, NR.sup.5, P(?O)(R.sup.5), O, S, SO, and SO.sub.2; R.sup.3 is selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, and alkenyl or alkynyl groups having 2 to 20 C atoms, wherein two or more radicals R.sup.3 are optionally connected to each other so as to define a ring; wherein the alkyl, alkoxy, alkenyl, and alkynyl groups are in each case optionally substituted by one or more radicals R.sup.5, and wherein one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are in each case optionally replaced by R.sup.5C?CR.sup.5, C?C, Si(R.sup.5).sub.2, C?O, C?NR.sup.5, C(?O)O, C(?O)NR.sup.5, NR.sup.5, P(?O)(R.sup.5), O, S, SO, or SO.sub.2; R.sup.5 is selected, identically or differently on each occurrence, from the group consisting of H, D, F, C(?O)R.sup.6, CN, Si(R.sup.6).sub.3, N(R.sup.6).sub.2, P(?O)(R.sup.6).sub.2, OR.sup.6, S(?O)R.sup.6, S(?O).sub.2R.sup.6, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherein the alkyl, alkoxy, alkenyl, and alkynyl groups and the aromatic and heteroaromatic ring systems are in each case optionally substituted by one or more radicals R.sup.6, and wherein one or more CH.sub.2 groups in the alkyl, alkoxy, alkenyl, and alkynyl groups are in each case optionally replaced by R.sup.6C?CR.sup.6, C?C, Si(R.sup.6).sub.2, C?O, C?NR.sup.6, C(?O)O, C(?O)NR.sup.6, NR.sup.6, P(?O)(R.sup.6), O, S, SO, or SO.sub.2; and R.sup.6 is selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, alkyl groups having 1 to 20 C atoms, aromatic ring systems having 6 to 40 C atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, wherein the alkyl groups, aromatic ring systems, and heteroaromatic ring systems are optionally substituted by F and CN.

18. The compound of claim 17, wherein Ar.sup.l is a phenyl or a naphthyl group, each of which is optionally substituted by one or more radicals R.sup.1.

19. The compound of claim 17, wherein Ar.sup.2 is selected from the group consisting of phenyl, 1-naphthyl, fluorenyl, benzofluorenyl, indenofluorenyl, spirobifluorenyl, benzoindenofluorenyl, phenanthrenyl, anthracenyl, pyrenyl, benzanthracenyl, and benzophenanthrenyl, each which is optionally substituted by one or more radicals R.sup.2, and heteroaromatic ring systems having 5 to 30 aromatic ring atoms, which is optionally substituted by radicals R.sup.2.

20. The compound of claim 17, wherein Ar.sup.2 is a phenyl group, which is optionally substituted by radicals R.sup.2, or a heteroaromatic ring system having 5 to 18 aromatic ring atoms, which is optionally substituted by radicals R.sup.2.

21. The compound of claim 17, wherein the compound is a compound of formulae (I-1) or (I-2): ##STR00106## wherein the phenanthrene group is optionally substituted by radicals R.sup.3 in the free positions, and the anthracene group is optionally substituted by radicals R.sup.4 in the free positions, and the phenyl group is optionally substituted by radicals R.sup.2 in the free positions; and A.sub.2Het is a heteroaromatic ring system having 5 to 18 aromatic ring atoms, which is optionally substituted by radicals R.sup.2.

22. The compound of claim 17, wherein R.sup.1 is selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, Si(R.sup.5).sub.3, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, and branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms; and wherein the alkyl and alkoxy groups are in each case optionally substituted by one or more radicals R.sup.5.

23. The compound of claim 17, wherein if Ar.sup.2 is phenyl, radicals R.sup.2 bonded thereto are selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, Si(R.sup.5).sub.3, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, and heteroaryl groups having 5 to 20 aromatic ring atoms, wherein the alkyl and alkoxy and heteroaryl groups are in each case optionally substituted by one or more radicals R.sup.5, and wherein one or more CH.sub.2 groups in the alkyl and alkoxy groups are in each case optionally replaced by R.sup.5C?CR.sup.5, C?C, Si(R.sup.5).sub.2, C?O, C?NR.sup.5, C(?O)O, C(?O)NR.sup.5, NR.sup.5, P(?O)(R.sup.5), O, S, SO, or SO.sub.2.

24. The compound of claim 17, wherein radicals R.sup.3 are selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, and branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, wherein the alkyl or alkoxy groups are in each case optionally substituted by one or more radicals R.sup.5.

25. The compound of claim 17, wherein radicals R.sup.3 are H or D.

26. A process for preparing a compound of claim 17, comprising (1) preparing an aryl-substituted phenanthrene derivative by a sequence comprising a transition metal catalysed coupling reaction and a carbocyclization reaction; and (2) coupling the aryl-substituted phenanthrene derivative to an anthracene derivative in a transition metal catalysed coupling reaction.

27. An oligomer, polymer, or dendrimer comprising one or more compounds according to claim 17, where the bond(s) to the polymer, oligomer, or dendrimer are optionally localised at any desired position(s) in formula (I) which are substituted by R.sup.1, R.sup.2, R.sup.3, or R.sup.4.

28. A formulation comprising at least one compound of claim 17 and at least one solvent.

29. A formulation comprising at least one oligomer, polymer, or dendrimer of claim 27 and at least one solvent.

30. An electronic device selected from the group consisting of organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, organic light-emitting electrochemical cells, organic laser diodes, and organic electroluminescent devices, comprising at least one compound of claim 17.

31. An electronic device selected from the group consisting of organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, organic light-emitting electrochemical cells, organic laser diodes, and organic electroluminescent devices, comprising at least one oligomer, polymer, or dendrimer of claim 27.

32. The electronic device of claim 30, wherein the electronic device is selected from the group consisting of organic electroluminescent devices comprising an anode, a cathode, an emitting layer, and optionally further organic layers, wherein the at least one compound is present in an emitting layer or in a layer with electron transporting function.

33. The electronic device of claim 31, wherein the electronic device is selected from the group consisting of organic electroluminescent devices comprising an anode, a cathode, an emitting layer, and optionally further organic layers, wherein the at least one oligomer, polymer, or dendrimer is present in an emitting layer or in a layer with electron transporting function.

34. The electronic device of claim 32, wherein the at least one compound is present as a matrix material in combination with a fluorescent emitter in an emitting layer or is present as an electron transporting material in a layer with electron transporting function.

35. The electronic device of claim 33, wherein the at least one oligomer, polymer, or dendrimer is present as a matrix material in combination with a fluorescent emitter in an emitting layer or is present as an electron transporting material in a layer with electron transporting function.

Description

WORKING EXAMPLES

A) Synthesis of Compounds

[0106] The following syntheses are generally performed under a protective gas atmosphere and with dried solvents.

##STR00061##

[0107] Reaction 1: Sonogashira coupling, Copper(I) catalysis, Pd catalysis

[0108] Reaction 2: Suzuki reaction, Pd catalysis

[0109] Reaction 3: Metal-induced carbocyclization, Iron(III) triflate

[0110] Reaction 4: Borane, Pd catalysis

[0111] Reaction 5: Br-anthracene derivative, Pd catalysis, Suzuki reaction

Example 1a

[0112] 50 g (0.16 mol) 2-bromo-4-chloro-1-iodobenzene, 17.3 mL (0.16 mol) phenylacetylene, 1.66 g (2.4 mmol) bis(triphenylphosphine)palladium(II) chloride and 0.3 g (1.6 mmol) copper(I) iodide are mixed in 500 mL of triethylamine and stirred for 2 h at 80? C. Then, the mixture is left to cool to room temperature and 200 mL of saturated aqueous ammonium chloride solution and 400 mL of toluene are added. The phases are separated. The organic phase is washed multiple times with water, and then filtered over silica. After crystallization from ethanol, the product is obtained as a solid. Yield: 38 g (0.13 mol; 83%).

[0113] In analogous manner, the following compounds can be obtained:

TABLE-US-00002 starting material compound 1 yield 1b [00062] [00063] 72% 1c [00064] [00065] 81%

Example 2a

[0114] 36 g (0.13 mol) 1a, 16.5 g (0.13 mol) phenylboronic acid, 1.85 g (2.6 mmol) bis(triphenylphosphine)palladium(II) chloride and 27.6 g (0.26 mol) sodium carbonate are mixed in 700 mL toluene/ethanol/water (2:1:1) and are heated under reflux for 5 h. After cooling the mixture to room temperature, 300 mL of water and 300 mL of toluene are added. The phases are separated. The organic phase is washed multiple times with water and the solvent is removed in vacuo. The crude product is purified by column chromatography on silica (heptane). The desired product is obtained as a colorless solid. Yield: 23 g (0.8 mmol, 62%).

[0115] In analogous manner, the following compounds can be obtained:

TABLE-US-00003 Starting material compound 2 yield 2b [00066] [00067] 85% 2c [00068] [00069] 78%

Example 3a

[0116] 22.2 g (0.077 mol) 2a and 773 mg (1.5 mmol) iron(III) triflate are stirred for 3 hours at 80? C. in 400 mL dichloroethane. Then, the mixture is filtrated over silica, and the solvent is evaporated in vacuo. Yield: 22 g (76 mmol; 99%).

[0117] In analogous manner, the following compounds can be obtained:

TABLE-US-00004 Starting material compound 3 yield 3b [00070] [00071] 97% 3c [00072] [00073] 96%

Example 4a

[0118] 22 g (76 mmol) 3a, 23.2 g (91 mmol) bis(pinacolato)diboran, 1.12 g (1.5 mmol) bis(tricyclohexylphosphine)palladium(II) chloride and 12.7 g (130 mmol) potassium acetate are stirred for 16 h at 90? C. in 300 mL dioxane, and then allowed to cool to room temperature. Afterwards, the mixture is filtrated first over aluminium oxide, and then over silica, and washed with toluene. The solvents are removed in vacuo, and the residue is recrystallized from heptane. The product is isolated as a colorless solid in a yield of 19.6 g (51.5 mmol; 77%).

[0119] In analogous manner, the following compounds can be obtained:

TABLE-US-00005 Starting material compound 4 yield 4b [00074] [00075] 65% 4c [00076] [00077] 83%

Example 5a

[0120] 18.9 g (50 mmol) 4a, 15.5 g (47 mmol) 9-bromo-10-phenylanthracene, 1 g (0.9 mmol) tetrakis(triphenylphosphine)palladium(0) and 17.9 g (0.17 mmol) sodium carbonate are heated under reflux in 600 ml toluene/ethanol/water (2:1:1) for 16 h. After cooling the mixture to room temperature, 200 mL of toluene is added and the phases are separated. The organic phase is washed multiple times with water and the solvent is removed in vacuo. Afterwards, the organic phase is filtrated over aluminium oxide. The product is further purified by recrystallization from toluene and subsequent sublimation. Yield: 7.8 g (15.4 mmol; 33%).

[0121] In analogous manner, the following compounds can be obtained:

TABLE-US-00006 Starting material Starting material (phenanthrene (anthracene derivative) derivative) compound 5 yield 5b [00078] [00079] [00080] 52% 5c [00081] [00082] [00083] 41% 5d [00084] [00085] [00086] 40% 5e [00087] [00088] [00089] 49% 5f [00090] [00091] [00092] 38%

B) Device Examples

Fabrication of OLED Devices

[0122] The manufacturing of the OLEDs is performed accordingly to WO 04/05891 with adapted film thicknesses and layer sequences. The following examples V1 to E7 (see Table 1) show data of various OLEDs.

Substrate Pre-Treatment of Examples V1-E8:

[0123] Glass plates with structured ITO (50 nm, indium tin oxide) are coated with 20 nm PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate, CLEVIOS? P VP Al 4083 from Heraeus Precious Metals GmbH Germany, spin-coated from a water-based solution) and form the substrates on which the OLEDs are processed.

[0124] The OLEDs have in principle the following layer structure: [0125] Substrate, [0126] ITO (50 nm), [0127] Buffer (20 nm), [0128] Hole injection layer (HTL1 95%, HIL 5%) (20 nm), [0129] Hole transporting layer (HTL2) (20 nm), [0130] Emissive layer (EML) (20 nm), [0131] Electron transporting layer (see table 2, EIL 50%) (30 nm), [0132] Electron injection layer (EIL) (3 nm), [0133] Cathode.

[0134] The cathode is formed by an aluminium layer with a thickness of 100 nm. The materials used for the OLED fabrication are presented in Table 1.

[0135] All materials are applied by thermal vapour deposition in a vacuum chamber. The emission layer here always consists of at least one matrix material (host material=H) and an emitting dopant (emitter=D), which is admixed with the matrix material or matrix materials in a certain proportion by volume by co-evaporation. An expression such as H1:D1 (95%:5%) here means that material H1 is present in the layer in a proportion by volume of 95%, whereas D1 is present in the layer in a proportion of 5%. Analogously, the electron-transport layer may also consist of a mixture of two or more materials.

[0136] The OLEDs are characterised by standard methods. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A) and the external quantum efficiency (EQE, measured in % at 1000 cd/m.sup.2) are determined from current/voltage/luminance characteristic lines (IUL characteristic lines) assuming a Lambertian emission profile. The electroluminescence (EL) spectra are recorded at a luminous density of 1000 cd/m.sup.2 and the CIE 1931 x and y coordinates are then calculated from the EL spectrum. For all experiments, the lifetime LT95 is determined. The lifetime LT95 @ 1000 cd/m.sup.2 is defined as the time after which the initial luminous density of 1000 cd/m.sup.2 has dropped by 5%. The device data of various OLEDs is summarized in Table 2. The examples starting with a V are comparison examples according to the state-of-the-art. The examples starting with an E represent OLEDs according to the invention.

[0137] In the following section several examples are described in more detail to show the advantages of the inventive OLEDs.

Use of Inventive Compounds as Host Material in Fluorescent OLEDs

[0138] The inventive compounds, represented by H1 and H2, are expecially suitable as host materials in fluorescent blue emissive layers of OLEDs. Comparison examples for the state-of-the-art are represented by VH-1 and VH-2, either doped by fluorescent emitters D1 or D2.

[0139] The use of the inventive compound as a host material with a single substitution of a phenyl at the phenanthren (H1 in devices E3 and E4) results in significantly improved OLED device date compared to the state-of-the-art, where the phenanthren is substituted two times by a phenyl ring (VH-1 in devices V1 and V2).

[0140] Furthermore, the inventive compound with a 1-naphthyl substitution (H2) yields improved EQE and lifetime (devices E7 and E8) compared to the state-of-the-art compound which bears a 2-naphthyl group in the respective position (VH-2 in devices V5 and V6).

[0141] In summary, the use of the inventive compounds as host material results in significantly improved OLED device data compared to state-of-the-art materials, especially with respect to external quantum efficiency and device lifetime.

[0142] In addition, the inventive compounds are also suitable as electron transporting materials e.g. in fluorescent blue emissive layers of OLEDs, here represented by ETL2. The use of the inventive compound as electron transporting material results in competitive OLED device data, compare device example E9 with state-of-the-art electron transporting material in device V1.

TABLE-US-00007 TABLE 1 Chemical structures of the OLED materials [00093] HIL [00094] HTL1 [00095] HTL2 [00096] VETL1 [00097] EIL [00098] VH-1 [00099] H1 [00100] VH-2 [00101] H2 [00102] D1 [00103] D2 [00104] ETL2

TABLE-US-00008 Tabelle 2: Device data of OLEDs EQE LD95 @ @ Host Dopant ETL 1000 cd/m.sup.2 1000 cd/m.sup.2 CIE Example 95% 5% 50% % [h] x y V1 VH-1 D1 VETL1 5.5 40 0.14 0.14 V2 VH-1 D2 VETL1 5.7 50 0.14 0.10 E3 H-1 D1 VETL1 7.2 75 0.15 0.13 E4 H-1 D2 VETL1 7.5 100 0.15 0.09 V5 VH-2 D1 VETL1 6.6 70 0.14 0.14 V6 VH-2 D2 VETL1 7.0 85 0.14 0.10 E7 H-2 D1 VETL1 6.9 90 0.14 0.14 E8 H-2 D2 VETL1 7.3 105 0.14 0.10 E9 VH-1 D1 ETL2 5.6 35 0.14 0.14