Materials for Electronic Devices

Abstract

The present application relates to a substituted benzanthracene compound of a formula (I) or (II). The application furthermore relates to an electronic device which comprises the said benzanthracene compound.

Claims

1-17. (canceled)

18. A compound of formula (I) or (II): ##STR00165## wherein Ar.sup.1 is an aromatic ring system having 6 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2 or heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2; R.sup.0 is C(O)R.sup.3, CN, Si(R.sup.3).sub.3, P(O)(R.sup.3).sub.2, OR.sup.3, S(O)R.sup.3, S(O).sub.2R.sup.3, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein said groups are each optionally substituted by one or more radicals R.sup.3 and wherein one or more CH.sub.2 groups in said groups are optionally replaced by R.sup.3CCR.sup.3, CC, Si(R.sup.3).sub.2, CO, CNR.sup.3, C(O)O, C(O)NR.sup.3, NR.sup.3, P(O)(R.sup.3), O, S, SO, or SO.sub.2; wherein R.sup.0 is optionally linked to a group R.sup.1 so as to define a ring; L is an n-valent group selected from the group consisting of aromatic ring systems having 6 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R.sup.2, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are optionally substituted by one or more radicals R.sup.2; or L is a chemical bond, wherein n is equal to 2; R.sup.1 and R.sup.2 are on each occurrence, identically or differently, H, D, F, C(O)R.sup.3, CN, Si(R.sup.3).sub.3, N(R.sup.3).sub.2, P(O)(R.sup.3).sub.2, OR.sup.3, S(O)R.sup.3, S(O).sub.2R.sup.3, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein said groups are optionally substituted by one or more radicals R.sup.3 and wherein one or more CH.sub.2 groups in said groups are optionally replaced by R.sup.3CCR.sup.3, CC, Si(R.sup.3).sub.2, CO, CNR.sup.3, C(O)O, C(O)NR.sup.3, NR.sup.3, P(O)(R.sup.3), O, S, SO, or SO.sub.2, an aromatic ring system having 6 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.3, or a heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.3; and wherein two or more radicals R.sup.1 or R.sup.2 are optionally linked to one another so as to define a ring; R.sup.3 is on each occurrence, identically or differently, H, D, F, C(O)R.sup.4, CN, Si(R.sup.4).sub.3, N(R.sup.4).sub.2, P(O)(R.sup.4).sub.2, OR.sup.4, S(O)R.sup.4, S(O).sub.2R.sup.4, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, or an alkenyl or alkynyl group having 2 to 20 C atoms, wherein said groups are each optionally substituted by one or more radicals R.sup.4 and wherein one or more CH.sub.2 groups in said groups are optionally replaced by R.sup.4CCR.sup.4, CC, Si(R.sup.4).sub.2, CO, CNR.sup.4, C(O)O, C(O)NR.sup.4, NR.sup.4, P(O)(R.sup.4), O, S, SO or SO.sub.2, an aromatic ring system having 6 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.4, or a heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.4; and wherein two or more radicals R.sup.3 are optionally linked to one another so as to define a ring; R.sup.4 is on each occurrence, identically or differently, H, D, F, CN, or an aliphatic, aromatic, or heteroaromatic organic radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by D, F, or CN; and wherein two or more substituents R.sup.4 are optionally linked to one another so as to define a ring; n is 2, 3, 4, 5, or 6; wherein the compound of formula (I) or (II) optionally contains a radical R.sup.1 at each of the positions indicated as unsubstituted; and wherein the following compounds are excluded: ##STR00166## ##STR00167##

19. The compound of claim 1, wherein either a group R.sup.1 which is selected from the group consisting of H and D is present in position 7 or a group R.sup.0 is present in position 7.

20. The compound of claim 1, wherein the compound of formula (I) contains at least one condensed aryl group having 14 to 18 aromatic ring atoms in addition to the benzanthracene skeleton.

21. The compound of claim 1, wherein the group Ar.sup.1 is bonded in a position selected from the group consisting of positions 2, 3, 4, 5 and 6 on the benzanthracene.

22. The compound of claim 1, wherein the group L is bonded in a position selected from the group consisting of positions 2, 3, 4, 5 and 6 on the benzanthracene.

23. The compound of claim 1, wherein the group R.sup.0 is bonded in position 7 on the benzanthracene.

24. The compound of claim 1, wherein Ar.sup.1 is selected from the group consisting of benzene, naphthalene, anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzimidazole, pyrimidine, pyrazine and triazine, each of which are optionally substituted by one or more radicals R.sup.2.

25. The compound of claim 1, wherein R.sup.0 is selected from the group consisting of Si(R.sup.3).sub.3, straight-chain alkyl or alkoxy groups having 1 to 10 C atoms, or branched or cyclic alkyl or alkoxy groups having 3 to 10 C atoms, wherein said groups are each optionally substituted by one or more radicals R.sup.3.

26. The compound of claim 1, wherein L is selected from the group consisting of benzene, naphthalene, anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzimidazole, pyrimidine, pyrazine and triazine, each of which is optionally substituted by one or more radicals R.sup.2, or L is a single bond, wherein n is equal to 2.

27. The compound of claim 1, wherein n is equal to 2.

28. The compound of claim 1, wherein the compound of formula (I) or (II) is a compound of formulae (I-1), (I-2), (II-1), or (II-2): ##STR00168##

29. A process for preparing a compound of claim 1, comprising: A) steps 1) through 3) in the following sequence: 1) preparing a benzanthracene compound substituted by one or more aromatic or heteroaromatic ring systems via a coupling reaction between a benzanthracene derivative and an aromatic or heteroaromatic ring system; 2) halogenating the benzanthracene; 3) introducing a substituent into the halogenated position; or comprising B) steps I) and II) in the following sequence: I) preparing a substituted benzanthracene derivative from a naphthyl derivative and a phthalic anhydride; II) coupling the substituted benzanthracene derivative with an aromatic or heteroaromatic ring system.

30. The process of claim 29, wherein the halogenation is bromination.

31. An oligomer, polymer, or dendrimer comprising one or more compounds of claim 1, wherein the bond(s) to the polymer, oligomer, or dendrimer are optionally localised at any positions in formula (I) or (II) substituted by R.sup.1, R.sup.2, or R.sup.3.

32. A formulation comprising at least one compound of claim 1 and at least one solvent.

33. A formulation comprising at least one oligomer, polymer, or dendrimer of claim 31 and at least one solvent.

34. An electronic device comprising at least one compound of claim 1.

35. The electronic device of claim 34, wherein the electronic device is 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.

36. An electronic device comprising the least one oligomer, polymer, or dendrimer of claim 31.

37. The electronic device of claim 36, wherein the electronic device is 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.

38. The electronic device of claim 35, wherein the electronic device is an organic electroluminescent device comprising an anode, a cathode, an emitting layer, and optionally further organic layers, wherein the at least one compound is present in the emitting layer as a matrix compound in combination with one or more emitter compounds.

39. The electronic device of claim 37, wherein the electronic device is an organic electroluminescent device 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 the emitting layer as a matrix compound in combination with one or more emitter compounds.

Description

WORKING EXAMPLES

A) Synthesis Examples

[0128] The compounds according to the invention are prepared in accordance with the following synthesis scheme:

##STR00076##

[0129] To this end, firstly a benzanthracene-aryl compound II is prepared via a Suzuki coupling between a benzanthracene-boronic acid derivative I-b and an aryl bromide I-a (step 1). The compound is subsequently brominated to give a bromobenzanthracene compound III (step 2). In a final step 3, a substituent is introduced at the position of the bromine via a Suzuki coupling, giving the compound IV according to the invention.

Step 1

[0130] 4-(10-Phenylanthracen-9-yl)benzo[a]anthracene II-i is synthesised in accordance with the following literature procedure: WO 2008/145239, Working Example 8.

[0131] The following compounds are prepared analogously:

TABLE-US-00002 Starting material Starting material I-a I-b Product II Yield [00077] [00078] [00079] 67% [00080] [00081] [00082] 59% [00083] [00084] [00085] 52% [00086] [00087] [00088] 72%

Step 2

7-Bromo-4-(10-phenylanthracen-9-yl)benzo[a]anthracene III-i

[0132] 1 l of tetrahydrofuran is added to 4-(10-phenylanthracen-9-yl)benzo[a]-anthracene II-i (50 g, 104.0 mmol), N-bromosuccinimide (24.02 g, 135 mmol) and benzoyl peroxide (containing 25% of water) (12.7 ml, 20.8 mmol). The batch is heated under reflux overnight, cooled to room temperature and extended with 800 ml of chloroform and 500 ml of a 10% sodium thiosulfate solution. After phase separation, the aqueous phase is extracted a number of times with chloroform. The combined organic phases are washed with dist. water, dried over magnesium sulfate and filtered through aluminium oxide. The organic phase is evaporated. The residue is brought to precipitation using chlorobenzene and recrystallised from heptane, giving compound III-i as pale-yellow solid: 58.2 g (87% of theory).

[0133] As an alternative, NBS/HBr or bromine (catalytic) can be utilised as bromine source. In order to avoid overbromination, reactions were carried out at low temperature (for example 10 C.).

[0134] The following compounds are prepared analogously:

TABLE-US-00003 Starting material II Product III Yield [00089] [00090] 53% [00091] [00092] 64% [00093] [00094] 68% [00095] [00096] 64%

Step 3

7-Methyl-4-(10-phenylanthracen-9-yl)benzo[a]anthracene IV-i

[0135] 5.47 g (97%, 88.6 mmol) of methylboronic acid, 25 g (44.3 mmol) of 7-bromo-4-(10-phenylanthracen-9-yl)benzo[a]anthracene III-i and 20.4 g (88.6 mmol) of K.sub.3PO.sub.4*H.sub.2O are suspended in 500 ml of toluene. 1.09 g (2.66 mmol) of dicyclohexyl(2,6-dimethoxybiphenyl-2-yl)phosphine (SPhos) and 0.3 g (1.33 mmol) of palladium acetate are added to this suspension, and the reaction mixture is heated under reflux for 16 h. After cooling, the reaction mixture is diluted with water, the organic phase is separated off, washed three times with 100 ml of water and subsequently evaporated to dryness. After filtration of the crude product through silica gel with toluene, the residue remaining is recrystallised from toluene/heptane. The yield is 17.3 g (79% of theory).

[0136] The following compounds IV according to the invention are prepared analogously:

TABLE-US-00004 Boronic acid or boronic No. Starting material III acid ester Product IV Yield 1 [00097] [00098] [00099] 64% 2 [00100] [00101] [00102] 76% 3 [00103] [00104] [00105] 69% 4 [00106] [00107] [00108] 58% 5 [00109] [00110] [00111] 47% 6 [00112] [00113] [00114] 65% 7 [00115] MeB(OH).sub.2 [00116] 59% 8 [00117] [00118] [00119] 62% 9 [00120] [00121] [00122] 72% 10 [00123] [00124] [00125] 74% 11 [00126] MeB(OH).sub.2 [00127] 52% 12 [00128] [00129] [00130] 38% 13 [00131] [00132] [00133] 47% 14 [00134] [00135] [00136] 43% 15 [00137] [00138] [00139] 76% 16 [00140] [00141] [00142] 68% 17 [00143] [00144] [00145] 73%

B) Device Examples

[0137] B-1) Device Examples from the Gas Phase: Production of OLEDs

[0138] OLEDs according to the invention and OLEDs in accordance with the prior art are produced by a general process in accordance with WO 04/058911, which is adapted to the circumstances described here (layer-thickness variation, materials).

[0139] The substrates used are glass substrates coated with structured ITO (indium tin oxide) in a thickness of 50 nm. A layer of Clevios P VP AI 4083 (purchased from Heraeus Clevios GmbH, Leverkusen) with a thickness of 20 nm is applied by spin coating as buffer layer. All remaining materials are applied by thermal vapour deposition in a vacuum chamber.

[0140] The structure A used is as follows: [0141] substrate, [0142] ITO (50 nm), [0143] buffer layer (20 nm), [0144] hole-Injection layer (HTL1 95%, HIL 5%) (20 nm), [0145] hole-transport layer (HTL1) (20 nm), [0146] emission layer (95% of host, 5% of dopant) (20 nm), [0147] electron-transport layer (50% of ETL+50% of EIL) (30 nm), [0148] electron-injection layer (EIL) (3 nm), [0149] cathode (AI) (100 nm).

[0150] The materials used are shown in Table 1.

[0151] The emission layer (EML) always consists of at least one matrix material (host=H) and an emitting dopant (dopant=D), which is admixed with the matrix material in a certain proportion by volume by co-evaporation. An expression such as H-1:D1 (95%:5%) here means that material H-1 is present in the layer in a proportion by volume of 95% and D1 is present in the layer in a proportion of 5%.

[0152] The OLEDs are characterised by standard methods. For this purpose, the electroluminescence spectra are recorded, the current efficiency (measured in cd/A) and the external quantum efficiency (EQE, measured in percent) as a function of the luminous density assuming Lambert emission characteristics are calculated from current/voltage/luminous density characteristic lines (IUL characteristic lines), and finally the lifetime of the components is determined. The electroluminescence spectra are recorded at a luminous density of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated therefrom. The term EQE @ 1000 cd/m.sup.2 denotes the external quantum efficiency at an operating luminous density of 1000 cd/m.sup.2. The lifetime LT95 @ 1000 cd/m.sup.2 is the time which passes until the initial luminance has dropped by 5% from 1000 cd/m.sup.2. The data obtained for the various OLEDs are summarised in Table 2.

[0153] The compounds according to the invention are particularly suitable as matrix materials in blue-fluorescent OLEDs (see Examples V1-V5 and E6-E11). Two standard matrix materials VH-1 and VH-2, each comprising one of the dopants D1, D2 and D3 which fluoresce in the dark blue, serve as comparison. Matrices H-1 and H-2 are shown as compounds according to the invention. These are likewise used in combination with one of the dopants D1, D2 and D3.

TABLE-US-00005 TABLE 1 Structures of the materials used [00146] HIL [00147] ETL [00148] HTL1 [00149] EIL [00150] VH-1 [00151] VH-2 [00152] H-1 [00153] H-2 [00154] D1 [00155] D2 [00156] D3

TABLE-US-00006 TABLE 2 Data of the OLEDs EQE LT95 @ @ 1000 1000 Host Dopant cd/m.sup.2 cd/m.sup.2 CIE Example 95% 5% % [h] x y V1 VH-1 D1 8.0 90 0.136 0.145 V2 VH-1 D2 7.5 100 0.134 0.101 V3 VH-1 D3 6.6 10 0.142 0.086 V4 VH-2 D1 7.9 100 0.135 0.160 V5 VH-2 D3 6.9 30 0.144 0.082 E6 H-1 D1 8.3 150 0.134 0.147 E7 H-1 D2 8.6 170 0.145 0.099 E8 H-1 D3 7.0 110 0.144 0.084 E9 H-2 D1 8.2 140 0.137 0.141 E10 H-2 D2 8.5 150 0.145 0.093 E11 H-2 D3 6.8 90 0.148 0.076

[0154] Examples E6 to E11 show in a comparative examination with Comparative Examples V1 to V5 that compounds H-1 and H-2 according to the invention achieve an improved external quantum efficiency (EQE) and an increased lifetime (LT95) with comparable deep-blue emission compared with comparative materials VH-1 and VH-2.

B-2) Device Examples Processed from Solution: Production of OLEDs

[0155] The production of solution-based OLEDs is described in principle in the literature, for example in WO 2004/037887 and WO 2010/097155. In the following examples, the two production methods (application from gas phase and solution processing) were combined, so that processing up to and including the emission layer was carried out from solution and the subsequent layers (hole-blocking layer/electron-transport layer) were applied by vacuum vapour deposition. The general processes described above are for this purpose adapted to the circumstances described here (layer-thickness variation, materials) and combined as follows.

[0156] The structure B used is thus as follows: [0157] substrate, [0158] ITO (50 nm), [0159] PEDOT (20 nm), [0160] hole-transport layer (HIL2) (20 nm), [0161] emission layer (92% of host, 8% of dopant) (60 nm), [0162] electron-transport layer (ETL 50%+EIL 50%) (20 nm), [0163] cathode (AI).

[0164] The substrates used are glass plates coated with structured ITO (indium tin oxide) in a thickness of 50 nm. For better processing, these are coated with the buffer (PEDOT) Clevios P VP AI 4083 (Heraeus Clevios GmbH, Leverkusen). The spin coating is carried out from water in air. The layer is subsequently dried by heating at 180 C. for 10 minutes. The hole-transport and emission layers are applied to the glass plates coated in this way. The hole-transport layer is the polymer of the structure shown in Table 3, which was synthesised in accordance with WO 2010/097155. The polymer is dissolved in toluene, so that the solution typically has a solids content of approx. 5 g/l if, as here, the layer thickness of 20 nm which is typical for a device is to be achieved by means of spin coating. The layers are applied by spin coating in an inert-gas atmosphere, in the present case argon, and dried by heating at 180 C. for 60 min.

[0165] The emission layer is always composed of at least one matrix material (host material) and an emitting dopant (emitter). An expression such as H-1 (92%):D1 (8%) here means that material H-1 is present in the emission layer in a proportion by weight of 92% and dopant D1 is present in the emission layer in a proportion by weight of 8%. The mixture for the emission layer is dissolved in toluene. The typical solids content of such solutions is approx. 18 g/l if, as here, the layer thickness of 60 nm which is typical for a device is to be achieved by means of spin coating. The layers are applied by spin coating in an inert-gas atmosphere, in the present case argon, and dried by heating at 140 C. for 10 minutes. The materials used are shown in Table 3.

[0166] The materials for the electron-transport layer and for the cathode are applied by thermal vapour deposition in a vacuum chamber. The electron-transport layer, for example, may consist of more than one material, which are admixed with one another in a certain proportion by volume by co-evaporation. An expression such as ETM:EIL (50%:50%) here means that materials ETM and EIL are present in the layer in a proportion by volume of 50% each. The materials used in the present case are shown in Table 1.

TABLE-US-00007 TABLE 3 Structures of the materials used [00157] HIL2 [00158] D4 [00159] D5 [00160] VH-1 [00161] VH-3 [00162] VH-4 [00163] H-1 [00164] H-2

TABLE-US-00008 TABLE 4 Data of the OLEDs EQE LT80 @ @ 1000 10 mA/ Solu- Host Dopant cd/m.sup.2 cm.sup.2 CIE bility Tg Example 92% 8% % [h] x y g/l C. V6 VH-1 D4 4.8 200 0.142 0.211 70 175 V7 VH-1 D5 3.2 40 0.142 0.111 70 175 V8 VH-3 D4/D5 X X X X <1 148 V9 VH-4 D4 4.8 210 0.136 0.195 44 125 V10 VH-4 D5 3.4 50 0.145 0.119 44 125 E11 H-1 D4 5.0 280 0.137 0.201 40 152 E12 H-1 D5 3.6 80 0.147 0.125 40 152 E13 H-2 D4 4.8 300 0.135 0.197 45 143 E14 H-2 D5 3.5 90 0.146 0.120 45 143

[0167] The examples of Table 4 show compounds H-1 and H-2 according to the invention as host compounds for dopants D4 and D5. As comparison, the compounds in accordance with the prior art VH-1, VH-3 and VH-4 are shown, likewise in combination with dopants D4 and D5.

[0168] The results in Table 4 show that, besides an improved external quantum efficiency, it is possible to achieve a significantly improved lifetime (LT80) with deep-blue emission both compared with VH-1 and also with VH-4.

[0169] Reference material VH-3 cannot be processed from solution at all owing to the low solubility (Example V8; X=not determined).

[0170] The structures found are thus also suitable for solution processing besides the vapour-deposition process and result in excellent performance data.