ORGANIC COMPOUNDS WITH SOLUBLE GROUPS

Abstract

The present invention relates to soluble organic compounds, to compositions comprising these compounds, to formulations comprising the compounds or compositions, and to electronic devices.

Claims

1.-19. (canceled)

20. An organic luminescent TADF compound which does not contain any metals and which has a gap between the first excited triplet state (T.sub.1) and the first excited singlet state (S.sub.1) of not more than 0.15 eV, characterized in that the organic compound contains at least one solubilizing group.

21. The compound according to claim 20, wherein the compound is of the general formula (1) ##STR00211## where the symbols and indices used are as follows: m is an integer selected from 1, 2, 3, 4 and 5; n is an integer selected from 1, 2, 3, 4 and 5; p is an integer greater than or equal to 1; A is an acceptor group which may be substituted by one or more R.sup.1 radicals which may be the same or different at each instance; D is a donor group which may be substituted by one or more R.sup.1 radicals which may be the same or different at each instance; LG is a solubilizing group which may be bonded to A, D and/or V group; V is any organic bridge between the A and D groups or a single bond, where, when V is a single bond, either m or n is 1, where V may be substituted by one or more R.sup.1 radicals which may be the same or different at each instance; R.sup.1 is the same or different at each instance and is hydrogen, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or a silyl group or a substituted keto group having 1 to 40 carbon atoms, an alkoxycarbonyl group having 2 to 40 carbon atoms, an aryloxycarbonyl group having 7 to 40 carbon atoms, a crosslinkable group or a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 60 ring atoms, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, or a combination of these systems, where two or more of the R.sup.1 groups together may form a mono- or polycyclic, aliphatic or aromatic ring system.

22. The compound according to claim 21, wherein p is an integer from 1 to 4; LG is a solubilizing group which may be bonded to D group; R.sup.1 is the same or different at each instance and is hydrogen, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or a silyl group or a substituted keto group having 1 to 40 carbon atoms, an alkoxycarbonyl group having 2 to 40 carbon atoms, an aryloxycarbonyl group having 7 to 40 carbon atoms, a crosslinkable group or a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 60 ring atoms, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, or a combination of these systems, where two or more of the R.sup.1 groups together may form a mono- or polycyclic, aliphatic or aromatic ring system, and when no two or more of the R.sup.1 groups together can form a mono- or polycyclic, aliphatic or aromatic ring system.

23. The compound according to claim 20, wherein the TADF compound is an organic compound having a molecular weight of not more than 5000 g/mol,

24. The compound according to claim 20, wherein the TADF compound is an organic compound having a molecular weight of not more than 1000 g/mol.

25. The compound according to claim 20, wherein the A group contains a cyano, oxo or nitrile group or a pyrimidine or a pyrazine.

26. The compound according to claim 20, wherein the D group contains a diarylamino, diarylheteroarylamino, carbazole, indenocarbazole or indolocarbazole group.

27. The compound according to claim 20, wherein the LG group is selected from: a straight-chain alkyl or alkoxy group having 2 to 40 carbon atoms; a branched or cyclic alkyl or alkoxy group having 3 to 40 carbon atoms; an aromatic or heteroaromatic ring system having 3 or more aromatic or heteroaromatic rings which may be substituted by one or more identical or different R.sup.1 radicals; an aromatic or heteroaromatic ring system having 1 or 2 aromatic or heteroaromatic rings substituted in the ortho position by one or more identical or different R.sup.1 radicals other than H, where the rings may be substituted by further identical or different R.sup.1 radicals; a group of the formula (LG-1) ##STR00212## where the symbols used are as follows: Ar.sup.1, Ar.sup.2 are each independently an aryl or heteroaryl group which may be substituted by one or more R.sup.1 radicals, X is in each case independently N or CR.sup.2, where not more than one of the three X groups may be an N; R.sup.1, R.sup.2 are each independently hydrogen, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or a silyl group or a substituted keto group having 1 to 40 carbon atoms, an alkoxycarbonyl group having 2 to 40 carbon atoms, an aryloxycarbonyl group having 7 to 40 carbon atoms, a crosslinkable group or a substituted or unsubstituted aromatic or heteroaromatic ring system having 5 to 60 ring atoms, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, or a combination of these systems, where two or more of the R.sup.1 and/or R.sup.2 groups may form a mono- or polycyclic, aliphatic or aromatic ring system with one another and/or with the ring to which the R.sup.1 group is bonded; l is 0, 1, 2, 3 or 4; where the dotted bond indicates the bond from LG to A, D or V.

28. The compound according to claim 20, wherein the LG group is selected from the following groups, where the groups may have further substitution by one or more identical or different R.sup.1 radicals: ##STR00213## ##STR00214## ##STR00215## ##STR00216## ##STR00217## ##STR00218## ##STR00219## ##STR00220##

29. The compound according to claim 20, wherein the bridge V is selected from the following formulae which may be substituted by one or more R.sup.1 radicals which may be the same or different at each instance: ##STR00221##

30. The compound according to claim 20, wherein the compound contains at least 2, aromatic rings.

31. A composition comprising one or more of the compounds according to claim 20 and one or more functional materials selected from the group of the electron-conducting materials (ETM), electron-injecting materials (EIM), electron-blocking materials (EBM), hole-conducting materials (HTM), hole-injecting materials (HIM), hole-blocking materials (HBM), fluorescent emitters, phosphorescent emitters, matrix materials and inorganic nanoparticles.

32. The composition according to claim 29, wherein the composition comprises two matrix materials.

33. A formulation comprising at least one compound according to claim 20 and at least one solvent.

34. A process for producing an organic electronic device which comprises producing at least one layer of the electronic device from solution with the aid of the formulation according to claim 33.

35. An organic electronic device which comprises at least one compound according to claim 20.

36. The organic electronic device as claimed in claim 35, wherein the device is an organic light-emitting diode (OLED) or organic light-emitting electrochemical cell (OLEC, LEEC, LEC).

37. The device according to claim 35, wherein the device is selected from organic integrated circuits (OICs), organic field-effect transistors (OFETs), organic thin-film transistors (OTFTs), organic electroluminescent devices, organic solar cells (OSCs), organic optical detectors or organic photoreceptors.

38. The device according to claim 35, wherein the device is an organic electroluminescent device selected from the group consisting of the organic light-emitting transistors (OLETs), organic field quench devices (OFQDs), organic light-emitting electrochemical cells (OLECs, LECs, LEECs), organic laser diodes (O-lasers) and organic light-emitting diodes (OLEDs).

39. An organic electroluminescent device comprising at least one compound according to claim 20 in an emission layer.

Description

EXAMPLES

Example 1

Determination Methods

Quantum Chemistry Method for Determining Orbital Energies and Electronic States

[0224] The HOMO and LUMO energies and the triplet level and singlet levels of the materials are determined via quantum-chemical calculations. For this purpose, in the present case, the “Gaussian09, Revision D.01” software package (Gaussian Inc.) is used. For calculation of organic substances without metals (referred to as the “org.” method), a geometry optimization is first conducted by the semi-empirical method AM1 (Gaussian input line “# AM1 opt”) with charge 0 and multiplicity 1. Subsequently, on the basis of the optimized geometry, a single-point energy calculation is effected for the electronic ground state and the triplet level. This is done using the TDDFT (time dependent density functional theory) method B3PW91 with the 6-31G(d) basis set (Gaussian input line “# B3PW91/6-31G(d) td=(50-50,nstates=4)”) (charge 0, multiplicity 1). For organometallic compounds (referred to as the “M-org.” method), the geometry is optimized by the Hartree-Fock method and the LanL2 MB basis set (Gaussian input line “# HF/LanL2 MB opt”) (charge 0, multiplicity 1). The energy calculation is effected, as described above, analogously to that for the organic substances, except that the “LanL2DZ” basis set is used for the metal atom and the “6-31G(d)” basis set for the ligands (Gaussian input line “#B3PW91/gen pseudo=lanI2 td=(50-50,nstates=4)”). From the energy calculation, the HOMO is obtained as the last orbital occupied by two electrons (alpha occ. eigenvalues) and LUMO as the first unoccupied orbital (alpha virt. eigenvalues) in Hartree units, where HEh and LEh represent the HOMO energy in Hartree units and the LUMO energy in Hartree units respectively. This is used to determine the HOMO and LUMO value in electron volts, calibrated by cyclic voltammetry measurements, as follows:

HOMO(eV)=(HEh*27.212)*0.8308−1.118

LUMO(eV)=(LEh*27.212)*1.0658−0.5049

[0225] These values are to be regarded as HOMO and as LUMO of the materials in the context of this application.

[0226] The triplet level T.sub.1 of a material is defined as the relative excitation energy (in eV) of the triplet state having the lowest energy which is found by the quantum-chemical energy calculation.

[0227] The singlet level S.sub.1 of a material is defined as the relative excitation energy (in eV) of the singlet state having the second-lowest energy which is found by the quantum-chemical energy calculation.

[0228] The energetically lowest singlet state is referred to as S.sub.0.

[0229] The method described herein is independent of the software package used and always gives the same results. Examples of frequently utilized programs for this purpose are “Gaussian09” (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.). In the present case, the energies are calculated using the software package “Gaussian09, Revision D.01”.

[0230] Table 3 states the HOMO and LUMO energy values and S.sub.1 and T.sub.1 of the various materials.

Determination of Orbital Overlap

[0231] The overlap of the molecular orbitals involved in particular electronic transitions (charge transfer states) is described with the aid of the parameter Λ. The meaning of this parameter Λ is well known to those skilled in the art. The determination of the parameter by means of methods described in the prior art does not present any difficulties at all to the person skilled in the art. In the context of the present invention, the parameter Λ is determined by the PBHT method according to D. J. Tozer et al. (J. Chem. Phys. 128, 044118 (2008)), which is implemented, for example, in the Q-Chem 4.1 software package from Q-Chem, Inc. This calculates the molecular orbitals by the method described above. Subsequently, the spatial overlaps for all possible pairs of occupied molecular orbitals, φ.sub.i, and unoccupied (virtual) molecular orbitals, φ.sub.a, is determined by the following equation:

O.sub.ia=|φ.sub.i|∥φ.sub.a|

where the magnitudes of the orbitals are used for the calculation.

[0232] The parameter Λ is then found from the weighted sum total over all the pairs is of occupied and unoccupied molecular orbitals according to

[00001]$\Lambda =\frac{\underset{\mathrm{ia}}{.Math.}.Math.{\kappa }_{\mathrm{ia}}^2.Math.O_{\mathrm{ia}}}{\underset{\mathrm{ia}}{.Math.}.Math.{\kappa }_{\mathrm{ia}}^2}$

where the value of κ.sub.ia according to Tozer et al. is determined from the orbital coefficients in the excitation vectors of the solved TD (time-dependent) eigenvalue calculation and where 0≦Λ≦1.

Determination of PL Quantum Efficiency (PLQE)

[0233] A 50 nm-thick film of the emission layers used in the different OLEDs is applied to a suitable transparent substrate, preferably quartz, meaning that the layer contains the same materials in the same concentration as in the OLED. This is done using the same production conditions as in the production of the emission layer for the OLEDs. An absorption spectrum of this film is measured in the wavelength range of 350-500 nm. For this purpose, the reflection spectrum R(λ) and the transmission spectrum T(λ) of the sample are determined at an angle of incidence of 6° (i.e. incidence virtually at right angles). The absorption spectrum in the context of this application is defined as A(λ)=1−R(λ)−T(λ).

[0234] If A(λ)≦0.3 in the range of 350-500 nm, the wavelength corresponding to the maximum of the absorption spectrum in the range of 350-500 nm is defined as λ.sub.exc. If, for any wavelength, A(λ)>0.3, λ.sub.exc is defined as being the greatest wavelength at which A(λ) changes from a value of less than 0.3 to a value of greater than 0.3 or from a value of greater than 0.3 to a value of less than 0.3.

[0235] The PLQE is determined using a Hamamatsu C9920-02 measurement system. The principle is based on the excitation of the sample with light of a defined wavelength and the measurement of the radiation absorbed and emitted. During the measurement, the sample is within an Ulbricht sphere (“integrating sphere”). The spectrum of the excitation light is approximately Gaussian with a half-height width of <10 nm and a peak wavelength λ.sub.exc as defined above.

[0236] The PLQE is determined by the evaluation method customary for said measurement system. It should be strictly ensured that the sample does not come into contact with oxygen at any time, since the PLQE of materials having a small energy gap between S.sub.1 and T.sub.1 is very greatly reduced by oxygen (H. Uoyama et al., Nature 2012, Vol. 492, 234).

[0237] Table 2 states the PLQE for the emission layers of the OLEDs as defined above together with the excitation wavelength used.

Determination of Decay Time

[0238] The decay time is determined using a sample which has been produced as described above under “Determination of the PL quantum efficiency (PLQE)”. The measurement is effected under reduced pressure. The sample is excited at room temperature by a laser pulse of suitable intensity (wavelength 266 nm, pulse duration about 1.5 ns). After excitation (defined as t=0), the profile of the photoluminescence emitted against time is measured. For the measurement data from time t=250 ns, the decay time t.sub.a=t.sub.e−250 ns is determined. In this formula, t.sub.e is that time after t=250 ns at which the intensity has for the first time dropped to 1/e of its value at t=250 ns.

Determination of Solubility

[0239] In order to examine whether a material has a toluene solubility of 10 mg/ml or more, the procedure is as follows: 20 mg of material in solid form are initially charged in a sample bottle. At room temperature (20° C.), 2 ml of toluene are added. The bottle is closed and the contents are stirred at 60° C. on a heatable magnetic stirrer for 1 h. In the course of this, good thermal contact is ensured by means of an aluminium block having holes into which the bottles fit exactly. After 1 h, the bottle is removed and left to cool to room temperature. If a clear solution lacking any large particles is present in the bottle, at least 10 mg/ml of the material are soluble in toluene.

[0240] Solubilities with other solubility limits are determined in entirely the same way. The starting weight is also matched to 2 ml of solvent.

Example 2

Synthesis of Compounds 6a to 6f

[0241] ##STR00058##

Stage 1

(2-Bromophenyl)phenyl[1,1;3′,1″]terphenyl-5′-ylamine 3a

[0242] To a suspension of 50.0 g (200 mmol, 1.0 eq) of N-phenyl-2-bromoaniline [61613-22-7] and 85.5 g (240 mmol, 1.2 eq) of 5′-iodo-1,1′:3′,1″-terphenyl [87666-86-2] in 500 ml of toluene are added 23.1 g (240 mmol, 1.2 eq) of sodium tert-butoxide, and the mixture is degassed for 30 minutes. Subsequently, 1.35 g (6.0 mmol, 0.03 eq) of palladium(II) acetate and 10 ml (10 mmol, 0.05 eq) of a 1 N tri-tert-butyl phosphonate solution in toluene are added. The mixture is heated under reflux overnight and, after the reaction has ended, washed with water. The aqueous phase is extracted twice with toluene, the combined organic phases are dried over sodium sulphate and the solvent is removed on a rotary evaporator. 89.6 g (188 mmol, 94%) of a brownish oil are obtained.

[0243] The following are prepared analogously:

TABLE-US-00002 No. Reactant 2 Product Yield 3b [00059] [00060] 87% 3c [00061] [00062] 64% 3d [00063] [00064] 92% 3e [00065] [00066] 59% 3f [00067] [00068] 89% 3g [00069] [00070] 95% 3h [00071] [00072] 32% 3i [00073] [00074] 84% 3j [00075] [00076] 65%

Stage 2

2′,7′-Dibromo-10H-terphenyl-10H-spiro(acridine-9,9′-fluorene) 5a

[0244] A solution of 89.0 g (187 mmol, 1.0 eq) of the amine 3a is dissolved in 1 l of dried THF, and 75 ml of n-BuLi (187 mmol, 1.0 eq, 2.5 M in hexane) are added at −78° C. After the addition has ended, the reaction mixture is stirred at this temperature for one hour and then a solution of 63.2 g (187 mmol, 1.0 eq) in 400 ml of dried THF is added. The reaction mixture is stirred at −78° C. for a further 30 minutes and warmed to room temperature overnight. This is followed by quenching of the reaction with water, removal of the organic phase after addition of a little diethyl ether, and washing with water and saturated sodium chloride solution. The organic phase is dried over sodium sulphate and the solvent mixture is removed on a rotary evaporator. The isolated intermediate is added to a mixture of 100 ml of conc. HCl and 1 l of acetic acid and refluxed for 2 h. The reaction mixture is cooled, diluted with water and extracted with dichloromethane. The combined organic phases are washed with saturated sodium hydrogencarbonate solution and water, then dried over sodium sulphate, and the solvent is removed under reduced pressure. The resulting solid is recrystallized from toluene/heptane. 79.2 g (110 mmol, 59%) of a colourless solid are obtained.

[0245] The following are prepared analogously:

TABLE-US-00003 No Reactant 3 Reactant 4 Product 5 Yield 5b [00077] [00078] [00079] 41% 5c [00080] [00081] [00082] 32% 5d [00083] [00084] [00085] 22% 5e [00086] [00087] [00088] 54% 5f [00089] [00090] [00091] 67% 5g [00092] [00093] [00094] 71% 5h [00095] [00096] [00097] 78% 5i [00098] [00099] [00100] 18% 5j [00101] [00102] [00103] 63% 5k [00104] [00105] [00106] 44% 5k [00107] [00108] [00109] 37%

Stage 3

2′,7′-Cyano-10H-terphenyl-10H-spiro(acridine-9,9′-fluorene) 6a

[0246] A mixture of 79.0 g (110 mmol, 1.0 eq) of the dibromide 5a and 24.6 g (275 mmol, 2.5 eq) of copper(1) cyanide [544-92-3] in 1.2 l of NMP is stirred at 170° C. for 24 h. After the reaction has ended, the solution is added to 2 N sodium hydroxide solution, and sodium hypochlorite is added. The resulting solution is stirred for half an hour and extracted with toluene. The combined organic phases are washed with water and dried over sodium sulphate, and the solvent is removed on a rotary evaporator (crude yield: 56.3 g, 92.4 mmol, 84%). The resulting solid is recrystallized repeatedly from toluene/heptane until a purity of >99.9% (HPLC) is attained. Finally, the product is purified by means of sublimation. 28.1 g (46.2 mmol, 42%) of the target compound in high purity are obtained.

[0247] The following are prepared analogously:

TABLE-US-00004 No. Reactant 5 Product Yield 6b [00110] [00111] 54% 6c [00112] [00113] 47% 6d [00114] [00115] 68% 6e [00116] [00117] 33% 6f [00118] [00119] 71%

Example 3

Synthesis of Compound 8a

[0248] ##STR00120##

Stage 1

[0249] 20 g (33 mol, 1.0 eq) of reactant 5g are initially charged in 500 ml of DMF, and 12 g (68 mmol, 2.05 eq) of N-bromosuccinimide are added gradually. After three hours at room temperature, the precipitated solid is filtered off with suction and washed with ethanol. 24 g (31 mmol, 96%) of a beige solid 7a are obtained.

Stage 2

[0250] 24 g (31 mmol, 1.0 eq) of the dibromide 7a, 9.5 g (78 mmol, 2.5 eq) of phenylboronic acid and 26 g (124 mmol, 4.0 eq) of tripotassium phosphate are initially charged, and 375 ml of toluene, 150 ml of dioxane and 375 ml of water are added. After the mixture has been degassed to 30 minutes, 70 mg (0.31 mmol, 0.01 eq) of palladium(II) acetate and 570 mg (1.9 mmol, 0.06 eq) of tri-o-tolylphosphine are added and the mixture is stirred at 85° C. overnight. After the reaction has ended, the phases are separated in a separating funnel, the organic phase is extracted with toluene and the combined organic phases are washed with water. The organic phase is subsequently dried over sodium sulphate and the solvent is removed on a rotary evaporator. 22 g (29 mmol, 93%) of a colourless solid are obtained, which is recrystallized repeatedly from toluene/heptane until an HPLC purity of >99.9% is achieved. Finally, the target product obtained is purified by means of sublimation. 11.5 g (15 mmol, 48%) of compound 8a in high purity are obtained.

Example 4

Synthesis of Compounds 9a to 9f

[0251] ##STR00121##

[0252] 30 g (50 mmol, 1.0 eq) of the unpurified crude product 5g are dissolved under protective gas together with 16.5 g (250 mmol, 5.0 eq) of malononitrile in 1.5 l of dichloromethane. Subsequently, 250 ml (250 mmol, 5.0 eq) of titanium(IV) chloride as a 1 M solution in dichloromethane are added gradually, followed by 20 ml (500 mmol, 10 eq) of dried pyridine. The reaction mixture is boiled under reflux for 24 hours and the same amounts again of malononitrile, titanium(IV) chloride and dried pyridine are added. After the mixture has been boiled again under reflux for 24 hours, 500 ml of dichloromethane are added and the organic phase is washed successively with 10% HCl and 5% NaOH. The organic phase is dried over sodium sulphate and the solvent is removed on a rotary evaporator. The resulting solid, 11.7 g (18 mmol, 36%) is recrystallized with toluene/heptane until an HPLC purity of >99.9% is achieved; finally, a sublimation is conducted. 3.6 g (5.5 mmol, 11%) of product 9a in high purity are obtained.

[0253] The following are prepared analogously:

TABLE-US-00005 No Reactant 8 Product 9 Yield 9b [00122] [00123] 14% 9c [00124] [00125] 9% 9d [00126] [00127] 24% 9e [00128] [00129] 21% 9f [00130] [00131] 13%

Example 5

Synthesis of Compounds 14a to 14i

[0254] ##STR00132##

Stage 1

[0255] Formation of secondary amines 12a to 12h

[0256] The synthesis is conducted in accordance with the method for compound 3a.

[0257] The following are obtained analogously:

TABLE-US-00006 No. Reactant 10 Reactant 11 Product 12 Yield 12a [00133] [00134] [00135] 64% 12b [00136] [00137] [00138] 57% 12c [00139] [00140] [00141] 61% 12d [00142] [00143] [00144] 48% 12e [00145] [00146] [00147] 56% 12f [00148] [00149] [00150] 67% 12g [00151] [00152] [00153] 31% 12h [00154] [00155] [00156] 45%

Stage 2

Preparation of Target Compounds 14a to 14i

[0258] 5.7 g (11 mmol, 1.0 eq) of 2,7-dibromo-2′,T-dicyano-9,9′-spirobifluorene and 17 g (33 mmol, 3.0 eq) of the amine 12a are initially charged in 100 ml of dry toluene and degassed with argon for 30 minutes. Subsequently, 62 mg (0.28 mmol, 0.025 eq) of palladium(II) acetate and 0.55 ml (0.55 mmol, 0.05 eq) of tri-tert-butylphosphine (1 M in toluene) are added and the mixture is heated under reflux overnight. After the reaction has ended, water is added and the organic phase is removed and washed again with water. Subsequently, the combined aqueous phases are extracted with toluene. The organic phases are dried over sodium sulphate and the solvent is removed on a rotary evaporator. 11.5 g (8.3 mmol, 75%) of a beige solid are obtained, which is purified further by recrystallization with heptane/toluene until an HPLC purity>99.9% is achieved. Finally, the solid is subjected to heat treatment at 300° C. under reduced pressure for five hours. 8.9 g (6.4 mmol, 58%) of the target compound 14a are obtained.

[0259] The following are obtained analogously:

TABLE-US-00007 No. Reactant 12 Reactant 13 14b [00157] [00158] 14c [00159] [00160] 14d [00161] [00162] 14e [00163] [00164] 14f [00165] [00166] 14g [00167] [00168] 14h [00169] [00170] 14i [00171] [00172] No. Product 14 Yield 14b [00173] 58% 14c [00174] 31% 14d [00175] 46% 14e [00176] 67% 14f [00177] 18% 14g [00178] 25% 14h [00179] 49% 14i [00180] 69%

Example 6

Synthesis of Compounds 19a to 19f

[0260] ##STR00181##

Stage 1

3-(4-Propylphenyl)-9H-carbazole 17a

[0261] 25 g (100 mmol, 1.0 eq) of 3-bromo-9H-carbazole are initially charged together with 20 g (120 mmol, 1.2 eq) of 4-propylphenylboronic acid [134150-01-9] and 23 g of tripotassium phosphate (106 mmol, 1.06 eq), each in 350 ml of toluene, dioxane and water, and degassed for 30 minutes. Subsequently, 450 mg (2.0 mmol, 0.02 eqα) of palladium(II) acetate and 1.5 g (5.0 mmol, 0.05 eqα) of tri-o-tolylphosphine are added and the reaction mixture is heated to reflux overnight. After the reaction has ended, the organic phase is removed and washed with water. The aqueous phase is extracted with toluene and the combined organic phases are dried over sodium sulphate. The resulting solid is washed with ethanol. After drying, 26 g (91 mmol, 91%) of a pale beige solid 17a are obtained.

[0262] The following are prepared analogously;

TABLE-US-00008 No. Reactant 15 Reactant 16 Product 17 Yield 17b [00182] [00183] [00184] 88% 17c [00185] [00186] [00187] 64%

Stage 2

Synthesis of Target Compound 18a

Variant A:

[0263] To a well-stirred suspension of 3.6 g (91 mmol, 4.0 eq) of sodium hydride, 60% by weight dispersion in mineral oil, in 500 ml of THF are added in portions while cooling with ice, at about +10° C., 26 g (91 mmol, 4.0 eq) of compound 17a—Caution! Evolution of hydrogen! Foaming! After the addition has ended, the mixture is stirred for a further 30 minutes and then 6.6 g (23 mmol, 1.0 eq) of 1,3,5-tricyano-2,4,6-trifluorobenzene [363897-9] are added in portions while cooling with ice in such a way that the temperature does not exceed +20° C. After the addition has ended, the mixture is stirred at +10° C. for a further 2 h, then the cooling bath is removed, and the mixture is allowed to warm to 20-25° C., stirred for a further 2 h and then heated to 40° C. for another 12 h. After cooling to room temperature, the reaction is ended by dropwise addition of 30 ml of methanol and the reaction mixture is concentrated almost to dryness under reduced pressure. The residue is subjected to hot extractive stirring twice with 225 ml each time of a mixture of 175 ml of methanol and 50 ml of water and then once with 100 ml of methanol. Purification is effected by repeated recrystallization from heptane/toluene until an HPLC purity of >99.9% is achieved. 4.8 g (4.8 mmol, 21%) of a colourless solid 18a are obtained.

Variant B:

[0264] A well-stirred suspension of 3.6 g (91 mmol, 4.0 eq) of carbazole 17a, 6.6 g (23 mmol, 1.0 eq) of 1,3,5-tricyano-2,4,6-trifluorobenzene, 24.4 g (115 mmol, 5.0 eq) of tripotassium phosphate (anhydrous) and 200 g of glass beads in 500 ml of dimethylacetamide is stirred at 160° C. for 16 h. After cooling, 1000 ml of water are added, the precipitated solids are filtered off with suction, and these are washed twice with 300 ml each time of water and twice with 200 ml each time of methanol, and then dried under reduced pressure. Further purification is effected analogously to the purification described in Variant A. Yield: 7.8 g (7.8 mmol, 34%), purity: 99.9% by HPLC.

[0265] In an analogous manner, the following compounds are prepared:

TABLE-US-00009 No. Reactant 17 Reactant 18 Product 19 Yield 19b [00188] [00189] [00190] A 41% 19c [00191] [00192] [00193] A 24% 19d [00194] [00195] [00196] B 22% 19e [00197] [00198] [00199] A 37% 19f [00200] [00201] [00202] B 14%

[0266] A and B in the Yield column relate to the variants conducted for the different compounds.

Example 7

Solubilities

[0267] For good processibility from solution, a high solubility in standard solvents is of crucial significance. Standard solutions in toluene applied by means of spin-coating contain a mixture of the OLED-active substances having a total concentration of about 20 mg/ml. In the case of use of higher-boiling solvents, for example mesitylene, it is necessary to use even higher concentrations in order to achieve equal layer thicknesses. If an individual substance has only a solubility of 2 mg/ml in toluene, it is possible to process only mixtures having not more than 10% of this component from solution, and even smaller material proportions still from higher-boiling solvents. A solubility of 5 mg/ml, in contrast, allows the processing of mixtures having up to 25% of this component, and a solubility of 10 mg/ml correspondingly up to 50%.

[0268] The solubilities of selected materials can be found in table 1,

TABLE-US-00010 TABLE 1 Solubilities of selected materials Solubility in Solubility in Solubility in toluene > toluene > toluene > Ex. Material 2 mg/ml 5 mg/ml 10 mg/ml C1-1 [00203] yes no no C1-2 [00204] no no no C1-3 [00205] yes no no I1-1  6a yes yes no I1-2  9a yes yes yes I1-3  9e yes yes no I1-4 19d yes yes yes

Example 8

Device Examples

[0269] The materials which are required for the examples which follow are shown in table 2. The corresponding HOMO and LUMO energy levels and S.sub.1 and T.sub.1 are reported in table 3.

OLEDs Having an Emission Layer Processed from Solution

[0270] There are already many descriptions of the production of completely solution-based OLEDs in the literature, for example in WO 2004/037887. There have likewise been many previous descriptions of the production of vacuum-based OLEDs, including in WO 2004/058911.

[0271] In the examples discussed hereinafter, layers applied in a solution-based and vacuum-based manner were combined within an OLED, and so the processing up to and including the emission layer was effected from solution and in the subsequent layers (hole blocker layer and electron transport layer) from vacuum. For this purpose, the previously described general methods are matched to the circumstances described here (layer thickness variation, materials) and combined as follows:

[0272] The general structure is as follows: substrate/ITO (50 nm)/hole injection layer (HIL)/hole transport layer (HTL)/emission layer (EML)/hole blocker layer (HBL)/electron transport layer (ETL)/cathode (aluminium, 100 nm).

[0273] Cleaned glass plaques (cleaning in Miele laboratory glass washer, Merck Extran detergent) coated with structured ITO (indium tin oxide) of thickness 50 nm are treated with UV ozone plasma for 20 minutes and then, for better processing, coated with PEDOT:PSS (poly(3,4-ethylenedioxy-2,5-thiophene) polystyrenesulphonate, sourced from Heraeus Precious Metals GmbH & Co. KG, Germany). PEDOT:PSS is spun on from water under air and subsequently baked under air at 180° C. for 10 minutes in order to remove residual water. A crosslinkable hole transport layer is applied to these substrates. It consists of a polymer of the following structural formula:

##STR00206##

which has been synthesized according to WO 2010/097155. The material is dissolved in toluene. The solids content of the solution is 5 g/l. The layers are spun on in an inert gas atmosphere, argon in the present case, and baked at 180° C. for 60 minutes.

[0274] Subsequently, the emission layer is applied. The latter is always composed of at least one matrix material (host material) and an emitting dopant (emitter). Details given in such a form as IC2(60%):WB1(30%):6a(10%) mean that material IC2 is present in a proportion by weight of 60%, WB1 in a proportion by weight of 30% and 6a in a proportion by weight of 10% in the solution from which the emission layer is produced. A corresponding solids mixture for the emission layer is dissolved in toluene. The solids content is 18 g/I. The emission layer is spun on in a nitrogen atmosphere and baked at 180° C. in a nitrogen atmosphere for 10 minutes.

[0275] Subsequently, the samples are introduced into a vacuum chamber without contact with air and further layers are applied by thermal evaporation. If such a layer consists of two or more materials, the nomenclature described further up applies to the mixing ratios of the individual components, except that the proportions by weight should be replaced by proportions by volume.

[0276] To characterize the OLEDs, current-voltage-luminance characteristics are measured. Luminance is determined with a calibrated photodiode. In addition, the electroluminescence spectrum is measured at a luminance of 1000 cd/m.sup.2. Assuming Lambertian radiation characteristics, this is used to calculate the external quantum efficiency (EQE, measured in percent).

Comparative Example C2-1

[0277] For the emission layer, a solid mixture of IC2(60%):WB1(30%):20a(10%) is used. This is used as described above to produce a 60 nm-thick emission layer. Subsequently, a 10 nm-thick layer of the material ST1 and then a 40 nm-thick layer of ST1(50%):LiQ(50%) is applied by thermal evaporation under reduced pressure. Subsequently, a 100 nm-thick aluminium layer is applied as cathode by evaporation under reduced pressure.

[0278] The OLEDs exhibit green emission, 14.2% EQE at 1000 cd/m.sup.2, and require a voltage of 7.4 V for this luminance.

Inventive Example I2-1

[0279] The OLED corresponds to Example C2-1, except that, rather than the mixture IC2(60%):WB1(30%):20a(10%), the mixture

IC2(60%):WB1(25%):19d(15%) is used.

[0280] The OLEDs exhibit green emission, 14.6% EQE at 1000 cd/m.sup.2, and require a voltage of 7.3 V for this luminance.

Inventive Example I2-2

[0281] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(20%):19d(20%) is used.

[0282] The OLEDs exhibit green emission, 14.9% EQE at 1000 cd/m.sup.2, and require a voltage of 8.1 V for this luminance.

Inventive Example I2-3

[0283] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(25%):9a(15%) is used.

[0284] The OLEDs exhibit green emission, 12.8% EQE at 1000 cd/m.sup.2, and require a voltage of 7.5 V for this luminance.

Inventive Example I2-4

[0285] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(20%):9a(20%) is used.

[0286] The OLEDs exhibit green emission, 13.2% EQE at 1000 cd/m.sup.2, and require a voltage of 7.7 V for this luminance.

Inventive Example I2-5

[0287] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(25%):9e(15%) is used.

[0288] The OLEDs exhibit green emission, 12.5% EQE at 1000 cd/m.sup.2, and require a voltage of 7.3 V for this luminance.

Inventive Example I2-6

[0289] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(20%):9e(20%) is used.

[0290] The OLEDs exhibit green emission, 13.0% EQE at 1000 cd/m.sup.2, and require a voltage of 7.4 V for this luminance.

Inventive Example I2-7

[0291] The OLED corresponds to Example I2-1, except that the mixture

IC2(60%):WB1(20%):6a(20%) is used.

[0292] The OLEDs exhibit greenish blue emission, 10.5% EQE at 1000 cd/m.sup.2, and require a voltage of 7.2 V for this luminance.

Comparison of the Examples

[0293] In the inventive examples, it is found that the use of higher concentrations of the dopant is advantageous particularly for the efficiency of the components produced. These higher concentrations can be achieved only in the case of sufficient solubility of the dopant, which results from use of the inventive materials. Overall, it is possible with the inventive materials to achieve efficient solution-processed OLEDs without the use of transition metal complexes.

TABLE-US-00011 TABLE 2 Structural formulae of the materials of the OLEDs [00207] [00208] [00209] [00210]

TABLE-US-00012 TABLE 3 HOMO, LUMO, T.sub.1, S.sub.1 of the relevant materials HOMO LUMO S.sub.1 T.sub.1 Material Method (eV) (eV) (eV) (eV) IC2 org. −5.78 −2.84 3.04 2.69 WB1 org. −6.16 −2.24 3.38 2.95 ST1 org. −6.03 −2.82 3.32 2.68 LiQ organomet. −5.17 −2.39 2.85 2.13 6a org. −5.60 −3.01 2.47 2.46 9a org. −5.58 −3.32 2.18 2.17 9e org. −5.57 −3.29 2.20 2.19 19d org. −5.89 −3.66 2.11 2.10