Materials for organic electroluminescent devices

Abstract

The present invention relates to compounds of the formulae (1) to (4), which are suitable for use in electronic devices, in particular organic electroluminescent devices, to intermediate compounds for the compounds or formulae (1) to (4) and to electronic devices, which comprise the compounds of formulae (1) to (4).

Claims

1. A compound of one of the formulae (1) to (4), ##STR00636## where the following applies to the symbols and indices used: Y is selected from the group consisting of fluorescent emitting groups, phosphorescent emitting groups, host groups for fluorescent emitting compounds and host groups for phosphorescent emitting compounds, having a molecular weight equal or less than 3000 g/mol, and which may in each case be substituted by one or more radicals R.sup.1; Ar is on each occurrence, identically or differently, selected from the group consisting of aromatic ring systems having 6 to 18 aromatic ring atoms, which may in each case also be substituted by one or more radicals R, where two groups Ar are allowed to be connected via a single bond or a divalent bridge; T is on each occurrence, identically or differently selected from the group consisting of T1 to T19, ##STR00637## ##STR00638## ##STR00639## where the symbol(s) * in T1 to T19 indicates the bonding to the group(s) —(Ar).sub.m—Y in formulae (1) to (4); R and R.sup.1 stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, NO.sub.2, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 40 C atoms or branched or a cyclic alkyl, alkoxy or thioalkyl groups having 3 to 40 C atoms, each of which may be substituted by one or more radicals R.sup.2, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by R.sup.2C═CR.sup.2, C≡, C═O, C═S, SO, SO.sub.2, O or S and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO.sub.2, an aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which may in each case be substituted by one or more radicals R.sup.2, or an aryloxy groups having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R.sup.2, where two adjacent substituents R and/or two adjacent substituents R.sup.1 may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R.sup.2; R.sup.2 stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl groups having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, where in each case one or more non-adjacent CH.sub.2 groups may be replaced by SO, SO.sub.2, O, S and where one or more H atoms may be replaced by D, F, Cl, Br or I, or an aromatic or heteroaromatic ring system having 5 to 24 C atoms; m is on each occurrence, identically or differently, 1, 2, 3 or 4; n is an integer from 1 to 8; and p is on each occurrence, identically or differently, 0 or 1, with the proviso that at least one p is equal to 1 in formulae (1) and (2).

2. The compound according to claim 1, wherein m is on each occurrence, identically or differently, 1 or 2.

3. The compound according to claim 1, wherein the group Y is a phosphorescent emitting group selected from the group consisting of iridium, platinum and copper complexes.

4. The compound according to claim 1, wherein the group Y is a fluorescent emitting group selected from the group consisting of arylamines, indenofluorene derivatives and anthracene derivatives.

5. The compound according to claim 1, wherein the group Y is a host group for a phosphorescent emitting compound selected from spirobifluorene amines, aromatic ketones, aromatic phosphine oxides or aromatic sulfoides or sulfones, triarylamines, carbazole derivatives, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, silanes, azaboroles or boronic esters, triazine derivatives, zinc complexes, fluorene derivatives, diazasilole or tetraazasilole derivatives, diazaphosphole derivatives or bridged carbazole derivatives.

6. The compound according to claim 1, wherein the group Y is a host group for a fluorescent emitting compound selected from the group consisting of oligoarylenes comprising naphthalene, anthracene, benzanthracene, benzophenanthrene, pyrene, oligoarylenevinylenes, indenofluorene derivatives, ketones, phosphine oxides and sulfoxides.

7. The compound according to claim 1, wherein the group T has a molecular weight equal or superior to 350 g/mol.

8. A formulation comprising at least one compound according to claim 1 and at least one solvent.

9. The formulation according to claim 8, wherein the solvents is selected from the group consisting of aromatics, alkylaromatics, cyclohexanes, ketones, ethers, esters, amides, sulfones, sulfoxides and mixtures thereof.

10. A process for the preparation of the compound according to claim 1, which comprises bonding group T to a group Y, or in which a group T, which is previously substituted by a group Ar, is bonded to a group Y via the group Ar, where T, Y and Ar have the same meaning as in claim 1.

11. An electronic device comprising at least one compound according to claim 1, wherein the electronic device is selected from the group consisting of organic electroluminescent device, organic integrated circuit, organic field-effect transistor, organic thin-film transistor, organic light-emitting transistor, organic solar cell, dye-sensitised organic solar cell, organic optical detector, organic photoreceptor, organic field-quench device, light-emitting electrochemical cell, organic laser diode, organic plasmon emitting device and liquid-crystal device.

12. An organic electroluminescent device which comprises an emitting layer, where the said emitting layer comprises at least one compound according to claim 1.

13. The compound according to claim 1, wherein the group T is selected from the group consisting of T1, T2, T6, T9, T10, T11, T12, T15, T16 and T18.

14. The compound according to claim 1, wherein the group T is selected from the group consisting of T1, T2 and T6.

15. The compound according to claim 1, wherein the group T is selected from the group consisting of T1 and T2.

Description

EXAMPLES

(1) A) Y is a Fluorescent Emitting Group

a-1) Syntheses Examples

(2) The following syntheses are generally performed under a protective gas atmosphere and with dried solvents.

(3) ##STR00495##

(4) Step 1: Suzuki-Miyaura borylation, Pd catalysis

(5) Step 2: Suzuki cross-coupling (Pd); Me-Grignard addition; Condensation

(6) Step 3: Bromination

(7) Int 1a:

(8) 2,7-Dibromo-9,9-dioctyl-9H-fluorene (100 g, 0.17 mol), bis(pinacolato)-diboron (94.9 g, 0.37 mol) and potassium acetate (50 g, 0.51 mol) are suspended in 1.4 L dioxane. The solution is saturated with argon. PdCl.sub.2(dppf)-CH.sub.2Cl.sub.2 (4.2 g, 0.01 mol) is added. The reaction mixture is refluxed for 16 h and then cooled to room temperature. Ethyl acetate and water are added. The organic phase is washed with water (3×500 mL). The organic phase is concentrated under reduced pressure and the residue is purified by recrystallization from ethanol. The desired product Int 1a is obtained as a grey powder. Yield: 98 g (90%).

(9) In analogous manner, the following compounds can be obtained:

(10) TABLE-US-00012 starting material product Int 1 yield 90%

(11) Int 2a:

(12) Step 1: Int 1a (94 g, 0.146 mol), 1-bromo-naphthaline-2-carboxylic acid ethyl ester (104 g, 0.37 mmol) and sodium carbonate (56 g, 0.5 mol) are added to water/toluene/dioxane (1:1:1, 1.5 L). The solution is saturated with argon. Tetrakis(triphenylphosphin)-palladium(0) (15.2 g, 0.01 mol) is added and the reaction mixture is refluxed for 6 hours. After cooling down to room temperature toluene (500 mL) is added and the organic phase is washed with water (3×500 mL) and then concentrated under reduced pressure. The residue is purified by recrystallization from ethanol.

(13) To 115 g (0.145 mol) of the recrystallized intermediate are added 145 g (0.60 mol) cerium(III) chloride and 500 mL THF, and the mixture is stirred for 30 minutes and cooled to 0° C. 390 mL (1.17 mol) methyl magnesiumchloride (3M in THF) is diluted in 1 L THF and added dropwise to the reaction mixture at 0° C. The reaction mixture is allowed to warm to room temperature. After 16 hours 800 ml sat. aq. ammonium chloride is added at 0° C. Ethyl acetate (2×500 mL) is added, the combined organic phases are washed with water (2×500 mL) and concentrated under reduced pressure. The residue is purified by recrystallization from ethanol.

(14) To 103 g (0.14 mol) of the recrystallized intermediate is added 275 g amberlyst 15 and 1.5 L toluene. The reaction mixture is refluxed for 16 hours using a Dean-Stark apparatus. After cooling down to room temperature, the amberlyst is removed by filtration and the organic phase is concentrated under reduced pressure. The residue is purified by several recrystallizations from ethanol or heptane/toluene. The desired product Int 2a is obtained as a yellow solid. Yield: 73 g (70% over three steps).

(15) In analogous manner, the following compounds can be obtained:

(16) TABLE-US-00013 starting material product Int 2 yield 70%

(17) Int 3a:

(18) Int 2a (73 g, 101 mmol) is dissolved in 1 L DCM and cooled to −10° C. Br.sub.2 (33.1 g, 207 mmol) in 500 mL DCM is added dropwise. The reaction mixture is stirred one hour at 0° C. and then allowed to warm to room temperature. After 16 hours, 20 mL sodium thiosulfate solution is added and the mixture is stirred for 15 minutes. Water (1 L) is added, the organic phase is washed with water (3×500 mL) and the combined organic phases are concentrated under reduced pressure. The purified product Int 3a is obtained by multiple recrystallizations from ethanol or heptane/toluene. Yield: 66.4 g (74%).

(19) In analogous manner, the following compounds can be obtained:

(20) TABLE-US-00014 starting material product Int 3 yield 00 01 70%

(21) ##STR00502##

(22) Int 4:

(23) To 5α-Cholestan-3β-ol (104 g, 267 mmol) and triphenylphosphine (140 g, 534 mmol) stirring in THF (500 mL) at 0° C. is added N-bromosuccinimide (95.0 g, 534 mmol) portionwise over 1 h. The heterogeneous orange reaction mixture is warmed to RT and stirred overnight. The reaction is quenched by addition of 2N aqueous HCl, and diluted with 500 mL EtOAc. The reaction mixture is filtered, and the precipitate washed further with EtOAc. The organic phase is collected, and the aqueous phase extracted with EtOAc. The combined organic phases are dried with Na2SO4, filtered, concentrated to a brown oil, and combined with the initial collected precipitate. The crude is extracted with heptane, filtered and concentrated. The filtrate is concentrated, and purified by recrystallization from a heptane/ethanol mixture. The desired product Int 4 is obtained as a colorless powder. Yield: 93.8 g (78%).

(24) Int 5a:

(25) To a dried reaction flask under Ar is added 4-chlorophenylboronic acid (44.1 g, 282 mmol), nickel(II) iodide (4.41 g, 14.1 mmol), trans-2-aminocyclohexanol (3.08 g, 14.1 mmol) and NaHMDS (86.1 g, 469 mmol). The flask is cooled to 0° C. and anhydrous iPrOH (500 ml) is added by addition funnel to the reagents over 30 min (caution: exothermic), resulting in a free flowing heterogeneous mixture. The reaction mixture is warmed to RT and Int 4 (106 g, 235 mmol) is added as a solid. The reaction mixture is heated to 70° C. and stirred overnight. The reaction mixture is then cooled to RT, and diluted with 1 L heptane and passed through a plug of SiO2. The eluent is concentrated to dryness, taken up in 1 L refluxing EtOH, and cooled to RT. The resulting precipitate is collected by filtration, washing with EtOH. The desired product Int 5a is collected as a colorless powder. Yield: 81.6 g (72%).

(26) In analogous manner, the following compounds can be obtained:

(27) TABLE-US-00015 starting material product Int 5 yield 03 04 33% 05 06 53%

(28) Int 6a:

(29) A mixture of Int 5a (81.5 g, 169 mmol), bispinacolatodiboron (78.7 g, 304 mmol), and potassium acetate (49.7 g, 506 mmol) in 1,4-dioxane (500 mL) is degassed by bubbling with Ar for 10 min, then trans-dichlorobis(tricyclohexylphosphine)palladium(II) (7.55 g, 10.1 mmol) is added and the reaction mixture is stirred under Ar at 100° C. overnight. The reaction mixture is cooled to RT, diluted with 500 mL toluene and filtered through Celite. The filtrate is concentrated, taken up in DCM and filtered through a plug of SiO2, and the eluent concentrated to dryness. The resulting crude material is purified by recrystallization from EtOH. The desired product Int 6a is obtained as a light gray powder. Yield: 88.1 g (91%).

(30) In analogous manner, the following compounds can be obtained:

(31) TABLE-US-00016 starting material Int 5 product Int 6 yield Int 5b 07 83% Int 5c 08 88%

(32) Compound 1:

(33) ##STR00509##

(34) A mixture of 4-(10-Bromo-anthracen-9-yl)benzo[a]anthracene (4.83 g, 10.0 mmol), Int 6a (6.61 g, 11.5 mmol), and sodium carbonate (2.12 g, 20.0 mmol) in a toluene (100 ml)/dioxane (100 ml)/water (100 ml) solvent mixture is degassed by Ar sparging for 15 min. To the reaction mixture is then added tetrakis(triphenylphosphine)palladium(0) (580 mg, 0.50 mmol), and the mixture is heated to 95° C. with stirring overnight. The reaction mixture is cooled to RT, and the organic phase is extracted with toluene. The combined organics are concentrated and further purified by filtration through silica (eluting with toluene) and hot extraction through basic aluminum oxide (eluting with a toluene/heptane mixture). The desired product 1 is obtained as a colorless powder. Yield: 7.8 g (92%).

(35) In analogous manner, the following compounds can be obtained:

(36) TABLE-US-00017 Int 6 Aryl halide Product compound yield Int 6b 0 72% Int 6a 65% Int 6c 90%

a-2) Fabrication of OLEDs

(37) Device Examples Processed from Solution

(38) 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.

(39) The device structure used is thus as follows: substrate, ITO (50 nm), PEDOT (20 nm), hole-transport layer (HTL) (20 nm), emission layer (92% of host, 8% of dopant) (60 nm), electron-transport layer (ETL) (20 nm), electron-injection layer (EIL) (3 nm) cathode (Al) (100 nm).

(40) 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 Al 4083 (Heraeus Clevios GmbH, Leverkusen). The spin coating of the buffer 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.

(41) The hole-transport layer is the polymer of the structure shown in Table 2, which was synthesised in accordance with WO 2010/097155. The polymer is dissolved in toluene, so that the solution typically has a solid content of approx. 5 g/I 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.

(42) The emission layer (EML) is always composed of at least one matrix material (host=H) and an emitting dopant (emitter=D). An expression such as H1 (92%): D1 (8%) here means that material H1 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 solid content of such solutions is approx. 18 g/I 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 2.

(43) The materials for the electron-transport layer, the electron-injection 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%) would mean 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 2.

(44) 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 from this data. 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 data obtained for the various OLEDs are summarised in Table 1.

(45) Use of Compounds According to the Invention as Fluorescent Emitting Compounds in Organic Light Emitting Diodes

(46) Emitting compounds D1 and D2 correspond to compounds according to the invention. The state-of-the-art compound for comparison is represented by V-D1. All emitting compounds are used in combination with either host H1 or H2.

(47) Examples E1 to E4 show in a comparative examination with Comparative Examples V1 and V2 that according to the invention, compounds D1 and D2 achieve an improved external quantum efficiency (EQE) with deeper-blue emission as compared to comparative material V-D1. Especially the comparison of material V-D1 (Examples V1 and V2) with D2 (Examples E5 and E6) shows the technical effect of the present invention, in which appending a terpene-derived motif leads to an improved device performance compared to the state-of-the-art.

(48) TABLE-US-00018 TABLE 1 OLED data Emitting EQE @ Host compound 1000 cd/m.sup.2 CIE Example 92% 8% % x y V1 H1 V-D1 6.0 0.145 0.105 V2 H2 V-D1 5.7 0.145 0.108 E1 H1 D1 6.5 0.147 0.076 E2 H2 D1 6.5 0.148 0.078 E3 H1 D2 7.5 0.146 0.090 E4 H2 D2 7.3 0.145 0.094

(49) TABLE-US-00019 TABLE 2 Structures of the materials used HTL H1 H2 V-D1 0 D1 (com- pound 3) D2 (com- pound 4) EIL ETL

(50) Compounds according to the invention possess good solubility and thus are well suitable for solution processing. By this technique, electronic devices based on blue fluorescent emitting compounds with excellent performance data can be generated.

(51) Alternatively, or in addition, the compounds according to the invention may serve as host materials inside the emission layer (EML), as hole injection material (HIL), as hole transporting material (HTL), as electron transporting material (ETL) or as electron-injection material (EIL) in an organic light emitting diode.

(52) B) Y is a Phosphorescent Emitting Group

(53) The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The metal complexes are additionally handled with exclusion of light or under yellow light. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective FIGURES in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature.

b-1) Metal Organic Synthones Known from the Literature

b-1-1) Bidentate Complexes Bromo-Functionalized Ligands MS

(54) ##STR00524## ##STR00525## ##STR00526##

b-1-2) Tripodale Complexes With Bromo-Functionalized Ligands PS (Syntheses are Described in the Patent Application WO2016/124304)

(55) ##STR00527## ##STR00528## ##STR00529## ##STR00530## ##STR00531## ##STR00532##

b-2) Synthesis of the Compounds According to the Invention: Suzuki Coupling with the Bromo-Functionalized Iridium Complexes

(56) Variant a, Two-Phase Reaction Mixture:

(57) A suspension consisting of 10 mmol of a brominated complex, 12-20 mmol of boronic acid or boronic acid ester per Br-function and 40-90 mmol of tripotassium phosphate in a mixture of 200 ml of toluene, 100 ml of dioxane and 200 ml of water is mixed with 0.6 mmol Tri-o-tolylphosphine and then with 0.1 mmol of palladium(II)acetate and heated under reflux for 16 h. After cooling, 500 ml of water and 200 ml of toluene are added, the aqueous phase is separated from the organic phase, the organic phase is washed three times with 200 ml of water, then once with 200 ml of a saturated saline solution and dried over magnesium sulfate. The mixture is filtered through a Celite bed, washed with toluene, the toluene is removed almost completely in vacuum, 300 ml of methanol are added, the precipitated crude product is filtered, washed three times with 50 ml of methanol each time, and dried in vacuum. The crude product run through a silica gel column. The metal complex is finally annealed or sublimed. The annealing is carried out in the high vacuum (p approx. 10 6 mbar) in the temperature range of approx. 200-300° C.

(58) Variant B, Single-Phase Reaction Mixture:

(59) A suspension of 10 mmol of a brominated complex, 12-20 mmol of boronic acid or boronic acid ester per Br-function and 60-100 mmol of the base (potassium fluoride, tripotassium phosphate (anhydrous or monohydrate or trihydrate), potassium carbonate, cesium carbonate, etc.) and 100 g of glass beads (3 mm diameter) in 100 ml-500 ml of an aprotic solvent (THF, dioxane, xylene, mesitylene, dimethylacetamide, NMP, DMSO, etc.) is mixed with 0.6 mmol of tri-o-tolylphosphine and then with 0.1 mmol of palladium(II)Acetate and heated under reflux for 1-2 h. Alternatively, other phosphines such as, for example, triphenylphosphine, tri-tert-butylphosphine, Sphos, Xphos, RuPhos and XanthPhos can be used, the phosphine: palladium ratio being 3:1 to 1.2:1. The solvent is removed under vacuum, the product is mixed with a suitable solvent (toluene, dichloromethane, ethyl acetate, etc.) and purified as described in Variant A.

(60) Variant C:

(61) In the case of educt complexes, which are not very soluble, it may be advantageous to first carry out the Suzuki coupling according to variant B and to subject the obtained crude product to a new Suzuki coupling according to variant A in order to achieve a conversion as complete as possible. After the crude product has been isolated, remaining trace impurities of bromine can be removed by heating the crude product in toluene (100 ml) with 10 mg of palladium(II) cetate and 1 ml of hydrazine hydrate for 16 h. The crude product is then purified as described above.

Synthese Von Ir1

(62) ##STR00533##

(63) Variant A:

(64) The reaction is carried out using 892 mg (1.0 mmol) of MS1 and 2355 mg (4 mmol) of cholesterol phenylboronester (see synthesis above), 1911 mg (9 mmol) of tripotassium phosphate (anhydrous), 183 mg (0.6 mmol) of tri-o-tolylphosphine [6163-58-2], 23 mg (0.1 mmol) of palladium(II)acetate, 20 ml of toluene, 10 ml of dioxane and 20 ml of water, under reflux for 16 h. Two chromatographic separation in silica gel with toluene/ethyl acetate are performed using an automatic column chromatography Torrent, Company A. Semrau. Yield: 1.365 g (0.67 mmol) 67%; Purity: approx. 99.9% after HPLC.

(65) Analogously, the following compounds can be prepared by adapting the proportion of the molar amount of reactant with the molar amount of the bromine functionalities of the metal complexes:

(66) TABLE-US-00020 Product Metal complex educt Variant Yield 0 0 0 0 Ir41 PS17 C 67% 0

b-3) Fabrication of OLEDs

(67) Solution-Processed Devices:

(68) Obtained from Low Molecular Weight Soluble Functional Materials

(69) The iridium complexes according to the invention can also be processed from solution, which is also desirable owing to the high technical complexity in the case of vacuum processes. The production of such components is based on the production of polymer light-emitting diodes (PLEDs), which has already been described in many ways in the literature (eg in WO 2004/037887). The structure of such OLEDs is generally the following one: substrate/ITO/hole injection layer (60 nm)/interlayer (20 nm)/emission layer (60 nm)/hole blocking layer (10 nm)/electron transport layer (40 nm)/cathode. For this purpose, substrates of the company Technoprint (Sodalimeglas) are used, to which the ITO film (indium tin oxide, a transparent, conductive anode) is applied. The substrates are cleaned in the clean room with DI water and a detergent (Deconex 15 PF) and then activated by a UV/ozone plasma treatment. A hole injection layer (20 nm) is then also applied by spin coating in the clean room. The required spin rate depends on the degree of dilution and of the specific spin-coater geometry. In order to remove residual water from the layer, the substrates are heated for 30 minutes at 200° C. on a heating plate. The interlayer used is for hole transport, in this case a HL-X from Merck is used. The interlayer can alternatively be replaced by one or more layers, which only have to fulfill the condition, by which the downstream processing step of the EML deposition from solution do not lead to the dissolution of the interlayer(s). For the production of the emission layer, the triplet emitters according to the invention are dissolved together with the matrix materials in toluene or chlorobenzene or 3-phenoxytoluene. The typical solid content of such solutions is between 16 and 25 g/L when, as in this case, the typical layer thickness of 60 nm is to be achieved by means of spin coating. The solution-processed devices of type 1 contain an emission layer of M1: M2: IrL (30%: 45%: 25%), and the solution-processed devices of type 2 contain an emission layer of M1:M2:IrLa:IrLb (30%: 35%: 30%: 5%), i.e they contain two different Ir complexes. The emission layer is spun in an inert gas atmosphere, in the present case argon, and is heated at 160° C. for 10 minutes. The hole blocking layer (15 nm ETM1) and the electron transport layer (35 nm ETM1 (50%)/ETM2 (50%)) are evaporated thereon (Vapor deposition system from Lesker, typical vaporization pressure 5×10.sup.−6 mbar). Finally, a cathode of aluminum (100 nm) (high-purity metal from Aldrich) is evaporated. In order to protect the device from air and air moisture, the device is finally encapsulated and then characterized. The OLED examples mentioned are not yet optimized, Table 1 summarizes the data obtained.

(70) TABLE-US-00021 TABLE 1 Results obtained with materials processed from solution EQE (%) Voltage (V) LT50 (h) Emitting 1000 1000 CIE 1000 Ex. compound cd/m.sup.2 cd/m.sup.2 x/y cd/m.sup.2 Yellow - Green Typ 1 Ref-Green IrRef1 18.1 5.2 0.34/0.61 210000 G1 Ir1 19.4 5.3 0.34/0.62 220000 G2 Ir3 19.7 5.1 0.35/0.62 230000 G3 Ir8 19.5 5.0 0.48/0.50 270000 G4 Ir14 20.3 5.2 0.37/0.60 250000 G5 Ir16 21.4 5.1 0.41/0.57 250000 G6 Ir19 20.7 5.2 0.45/0.52 270000 G7 Ir25 21.7 4.7 0.32/0.63 270000 G8 Ir26 21.8 4.5 0.46/0.52 350000 G9 Ir38 22.1 4.3 0.33/0.63 330000 G10 Ir43 20.9 4.3 0.36/0.61 340000 G11 Ir48 22.2 4.4 0.34/0.62 350000 G12 Ir55 21.9 4.3 0.36/0.61 360000 Red Typ 2 R1 IrRef1 18.9 4.0 0.66/0.34 290000 Ir9 R2 Ir26 19.3 4.1 0.66/0.34 360000 Ir9

(71) TABLE-US-00022 TABLE 2 Structures of the materials 0

(72) C) Y is a Host Group

c-1) Syntheses Examples

(73) The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The metal complexes are additionally handled with exclusion of light or under yellow light. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective FIGURES in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature.

c-1-1) Organic Synthones Known from the Literature

(74) ##STR00596## ##STR00597## ##STR00598## ##STR00599## ##STR00600##

c-1-2) Synthesis of the Used Synthones

(75) 1)

(76) ##STR00601##

(77) 22.8 g (46.7 mmol) of Syn-8, 26.6 g (100 mmol, 2.20 eq) bis(pinacolato)diboron (CAS: 73183-34-3) and 13.89 g (140 mmol, 3.0 eq) of potassium acetate are dissolved in 1000 ml of anhydrous DMF and degassed into a heated 2000 ml 4-neck flask with KPG stirrer, reflux condenser, thermometer, dropping funnel and inert gas connection.

(78) 0.73 g (3.27 mmol, 0.07 eq) of palladium(II)acetate are added to the reaction mixture and the mixture is stirred at 100° C. for 24 hours. After cooling to room temperature, 1000 ml of water are added and the precipitated solid is filtered. The solid is collected with dichloromethane, washed with water, filtered through celite, and the solvent is removed under vacuum. The solid is dissolved in ethyl acetate and filtered over silica gel. A colorless solid Syn-12 is obtained as a product (11.7 g, 46.8 mmol, 47% yield).

(79) ##STR00602##

(80) 30 g (46.8 mmol) of Syn-17 are dissolved in 1250 ml of anhydrous THF in a 4000 ml 4-neck flask equipped with KPG stirrer, reflux condenser, thermometer, dropping funnel and inert gas connection and degassed.

(81) 8.33 g (46.8 mmol, 1 eq) of N-bromosuccinimide are added and the mixture is stirred at 50° C. for 4 days. The solvent is removed in vacuum, the residue is slurried with ethyl acetate, filtered, washed with ethyl acetate and dried in vacuum. A colorless solid Syn-18 is obtained as a product (32.8 g, 45.6 mmol, 97%).

c-1-3) Synthesis of Synthones According to the Invention

(82) ##STR00603##

Synthesis of BB-3

(83) ##STR00604##

(84) 1.15 g magnesium chips are weighed in a heated 500 ml 4-neck flask with KPG stirrer, reflux condenser, thermometer, dropping funnel and inert gas connection. 25 g (47.4 mmol) of BB-1 are weighed in the dropping funnel and mixed with 100 ml of anhydrous THF and 9.2 ml of ethylglycol dimethyl ether (99.5 mmol, 2.1 eq). The solution is slowly added dropwise to the magnesium so that the solvent boils slightly. The reaction mixture is boiled under reflux for 60 minutes and then cooled to 0° C.

(85) 10.7 g (47.4 mmol, 1 eq) of 2,4-dichloro-6-phenyl-[1,3,5]-triazine are added into a heated 500 ml 4-necked flask with a KPG stirrer, reflux condenser, thermometer, dropping funnel and mixed with 50 ml of anhydrous THF and cooled to 0° C. The cooled Grignard solution is slowly added to the reaction mixture so that the internal temperature does not rise above 5° C. The reaction mixture is slowly warmed to room temperature, then boiled under reflux for 48 hours. The mixture is cooled to room temperature and diluted with 100 ml of anhydrous THF. Under ice-cooling, 20 ml of water are carefully added, the mixture is stirred at room temperature and ethyl acetate is added. The organic phase is separated, extracted with water, removed from the solvent and dried. A colorless solid BB-3 is obtained as a product (17.1 g, 26.8 mmol, 57%).

c-1-4) Synthesis of Host Compounds According to the Invention

(86) 1)

(87) ##STR00605##

(88) 26 g (0.045 mol) of BB-1, 7.17 g (0.011 mol, 0.25 eq) of Syn-1 and 22.9 g of potassium phosphate monohydrate (0.1 mol, 2.2 eq) are weighed in a 1000 ml four-necked flask with KPG stirrer, heating head, reflux condenser and argon connection and mixed with 400 ml of toluene, 200 ml of 1,4-dioxane and 100 ml of water. The reaction solution is degassed and mixed with 253 mg (0.001 mol, 0.025 eq) of palladium(II)acetate and 688 mg of tri-o-tolylphosphine (0.002 mol, 0.05 eq). The reaction mixture is refluxed for 24 hours, then allowed to cool and mixed with water. The phases are separated, the aqueous phase is extracted several times with toluene, and the combined organic phases are separated from the solvent. Recrystallization from toluene/ethanol and heptane gives 7.8 g (0.003 mol, 27% yield) of the colorless solid H-1.

(89) Analogously, Syn-2 can be used instead of Syn-1 so that H-2 is obtained with a yield of 25%.

(90) ##STR00606##

(91) 2)

(92) ##STR00607##

(93) 19 g (0.033 mol) of BB-1, 12.7 g (0.033 mol, 1 eq) of Syn-3 and 30.9 g of potassium phosphate monohydrate (0.145 mol, 4.4 eq) are weighed in a 1000 ml four-neck flask with KPG stirrer, heating head, reflux condenser and argon overlay and mixed with 250 ml THF and 135 ml water. The reaction solution is degassed and treated with 2.8 g (0.003 mol, 0.1 eq) XPhos Palladacycle (CAS: 1028206-56-5). The reaction mixture is refluxed for 24 hours and then allowed to cool. Ethanol is added to the reaction mixture, the precipitated solid is filtered, washed with ethanol and dried. Recrystallization from methyl ethyl ketone and cyclohexane gives a colorless solid H-3 (4.2 g, 0.006 mol, 17% yield).

(94) The compounds H-4 to H-9 are obtained analogously by replacing Syn-3 with other synthons, see Table below:

(95) TABLE-US-00023 08 09 H-4 from Syn-4 Yield: 8% 0 H-5 from Syn-5 Yield: 7% H-8 From Syn-11 Yield: 18%

(96) 3)

(97) ##STR00615##

(98) 1.657 g of sodium hydride (0.041 mol) are weighed in a 2000 ml four-neck flask equipped with a KPG stirrer, heating head, reflux condenser and argon overlay, mixed with 150 ml of anhydrous dimethylformamide (DMF) and degassed. 14 g (0.035 mol, 0.83 eq) of Syn-6 are dissolved in 200 ml of anhydrous DMF, slowly added dropwise to the sodium hydride solution and the mixture is further stirred for 2 hours. 22.04 g (34.5 mmol, 0.83 eq) of BB-3 are dissolved in 250 ml of anhydrous DMF, slowly added dropwise to the reaction mixture and stirred for 24 hours at room temperature. 500 ml of water are added dropwise to the reaction solution, the precipitated solid is filtered and washed with water. The solid is recrystallized from ethanol and dried to give 29.5 g (29.5 mmol, 85% yield) of the colorless solid H-10.

(99) The compounds H-11 to H-15 are obtained analogously by replacing Syn-6 with other synthons, see Table below:

(100) TABLE-US-00024 0

(101) 4)

(102) ##STR00622##

(103) 12.7 g (23.7 mmol) of Syn-12, 15.14 g (23.7 mmol, 1 eq) of BB-3 and 5.5 g (52.2 mmol, 2.2 eq) of sodium carbonate are weighed in a 500 ml four-neck flask with KPG stirrer, heating head, reflux condenser and argon overlay and dissolved in 50 ml of water and 100 ml 1,4-Dioxane, and degassed. 411 mg (0.36 mmol, 0.015 eq) of tetrakis(triphenylphosphine)palladium(0) (CAS: 14221-01-3) are added and the reaction mixture is refluxed for 24 hours. After cooling to room temperature, the solid is collected by filtration and purified by repeated recrystallization from methyl-ethylketone. A colorless solid H-16 is obtained as a product (10.1 g, 9.96 mmol, 42% yield).

(104) The compounds H-17 to H-22 are obtained analogously by replacing Syn-6 with other synthons, see Table below:

(105) TABLE-US-00025

(106) 5)

(107) ##STR00629##

(108) 18.1 g (44.6 mmol) of Syn-6, 40 g (75.9 mmol, 1.7 eq) of BB-2, 6.61 g (66.7 mmol, 1.5 eq) of sodium tert-butylate are weighed in a 1000 ml four-neck flask with KPG stirrer, heating head, reflux condenser and argon overlay and degassed. 0.3 g (1.35 mmol, 0.03 eq) of palladium(II)acetate, 982 mg (2.67 mmol, 0.06 eq) of tricyclohexylphosphine tetrafluoroborate (CAS: 58656-04-5) and 450 ml of anhydrous o-xylene are added to the reaction mixture, which is boiled for 48 hours under reflux. After cooling to room temperature, the solvent is removed in vacuum, 300 ml of ethanol are added to the residue and the mixture is stirred at 50° C. for 3 hours. The solid is filtered, washed with ethanol and dried. Multiple recrystallization from toluene/heptane mixtures are performed. A colorless solid H-23 is obtained as a product (12.17 g, 14.3 mmol, 32%).

(109) The compounds H-24 to H-28 are obtained analogously by replacing Syn-6 with other synthons, see Table below:

(110) TABLE-US-00026 0 H-25 from Syn-13 Yield 29% H-26 from Syn-14 Yield 36% H-27 from Syn-15 Yield 33% H-28 from Syn-16 Yield 21%

c-5) Fabrication of OLEDs

(111) The host compounds H-1 to H-28 can be used as host compounds in the OLEDs described above in point b-3) instead of M1 and/or M2.