Metal complexes

Abstract

The present invention relates to iridium complexes suitable for use in organic electroluminescent devices, especially as emitters.

Claims

1. A compound of formula (1): ##STR00407## wherein L.sup.1 is a sub-ligand of formula (2): ##STR00408## which coordinates to the iridium via the two Z groups and which is bonded to V via the dotted bond; A is the same or different in each instance and is CR.sub.2, O, S, or NR, wherein at least one A group is CR.sub.2; Z is the same or different in each instance and is O, S, or NR; L.sup.2 is a bidentate, monoanionic sub-ligand which coordinates to the iridium via one carbon atom and one nitrogen atom or via two carbon atoms; L.sup.3 is a bidentate, monoanionic sub-ligand which coordinates to the iridium via one carbon atom and one nitrogen atom or via two carbon atoms, or is a sub-ligand of the formula (2) which is optionally the same as or different from L.sup.1; V is a group of formula (3), wherein the dotted bonds each denote the linkage of sub-ligands L.sup.1, L.sup.2 and L.sup.3, ##STR00409## X.sup.1 is the same or different in each instance and is CR or N; X.sup.2 is the same or different in each instance and is CR or N, or two adjacent X.sup.2 groups together are NR, O, or S, so as to define a five-membered ring; or two adjacent X.sup.2 groups together are CR or N when one of the X.sup.3 groups in the cycle is N, so as to form a five-membered ring; with the proviso that not more than two adjacent X.sup.2 groups in each ring are N; X.sup.3 is C in each instance in one cycle or one X.sup.3 group is N and the other X.sup.3 group in the same cycle is C, wherein the X.sup.3 groups in the three cycles are optionally selected independently, with the proviso that two adjacent X.sup.2 groups together are CR or N when one of the X.sup.3 groups in the cycle is N; R is the same or different in each instance and is H, D, F, Cl, Br, I, N(R.sup.1).sub.2, OR.sup.1, SR.sup.1, CN, NO.sub.2, COOH, C(═O)N(R.sup.1).sub.2, Si(R.sup.1).sub.3, B(OR.sup.1).sub.2, C(═O)R.sup.1, P(═O)(R.sup.1).sub.2, S(═O)R.sup.1, S(═O).sub.2R.sup.1, OSO.sub.2R.sup.1, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl, or alkynyl group in each case is optionally substituted by one or more R.sup.1 radicals and wherein one or more nonadjacent CH.sub.2 groups are optionally replaced by Si(R.sup.1).sub.2, C═O, NR.sup.1, O, S, or CONR.sup.1, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R.sup.1 radicals; and wherein two R radicals together optionally define a ring system; R.sup.1 is the same or different in each instance and is H, D, F, Cl, Br, I, N(R.sup.2).sub.2, OR.sup.2, SR.sup.2, CN, NO.sub.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, C(═O)R.sup.2, P(═O)(R.sup.2).sub.2, S(═O)R.sup.2, S(═O).sub.2R.sup.2, OSO.sub.2R.sup.2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl, or alkynyl group in each case are optionally substituted by one or more R.sup.2 radicals, wherein one or more nonadjacent CH.sub.2 groups are optionally replaced by Si(R.sup.2).sub.2, C═O, NR.sup.2, O, S, or CONR.sup.2, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and is optionally substituted in each case by one or more R.sup.2 radicals; and wherein two or more R.sup.1 radicals together optionally define a ring system; R.sup.2 is the same or different in each instance and is H, D, F, or an aliphatic, aromatic, and/or heteroaromatic organic radical having 1 to 20 carbon atoms, wherein one or more hydrogen atoms is optionally replaced by F; and wherein the three bidentate ligands L.sup.1, L.sup.2, and L.sup.3, in addition to bridge V, are also optionally connected via a further bridge so as to form a cryptate.

2. The compound of claim 1, wherein V is selected from the group consisting of formulae (4a) through (7a): ##STR00410##

3. The compound of claim 1, wherein V has a structure of formula (4b′), (4c), or (5c): ##STR00411##

4. The compound of claim 1, wherein both A groups in sub-ligand L.sup.1 are CR.sub.2.

5. The compound of claim 1, wherein both Z groups in sub-ligand L.sup.1 are O.

6. The compound of claim 1, wherein L.sup.1 has a structure of formula (2c): ##STR00412## wherein the dotted bond denotes the bond to V, and R is the same or different in each instance and is selected from the group consisting of H, D, OR.sup.1, a straight-chain alkyl group having 1 to 10 carbon atoms, optionally substituted in each case by one or more R.sup.1 radicals, a branched or cyclic alkyl group having 3 to 10 carbon atoms, optionally substituted in each case by one or more R.sup.1 radicals, and an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms optionally substituted in each case by one or more R.sup.1 radicals.

7. The compound of claim 1, wherein the two sub-ligands L.sup.2 and L.sup.3 each have one carbon atom and one nitrogen atom as coordinating atoms.

8. The compound of claim 1, wherein the sub-ligands L.sup.2 and L.sup.3 are the same or different at each instance and are a structure of the formula (L-1) or (L-2): ##STR00413## wherein the dotted bond represents the bond of the sub-ligand to V; CyC is the same or different in each instance and is a substituted or unsubstituted aryl or heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates in each case to the metal via a carbon atom and which is bonded to CyD via a covalent bond; CyD is the same or different in each instance and is a substituted or unsubstituted heteroaryl group which has 5 to 14 aromatic ring atoms and coordinates to the metal via a nitrogen atom or via a carbene carbon atom and which is bonded to CyC via a covalent bond; and wherein two or more of the optional substituents together optionally define a ring system.

9. The compound of claim 8, wherein one of the sub-ligands L.sup.2 and L.sup.3 has a structure of formula (L-1) and the other of the sub-ligands L.sup.2 and L.sup.3 has a structure of formula (L-2).

10. The compound of claim 8, wherein CyC is selected from the group consisting of structures of formulae (CyC-1) through (CyC-19), wherein the CyC group binds to CyD in each case at the position identified by #and to the iridium at the position identified by *, and wherein the CyD group is selected from the group consisting of structures of formulae (CyD-1) through (CyD-12), and wherein the CyD group binds to CyC in each case at the position identified by #and to the iridium at the position identified by *: ##STR00414## ##STR00415## ##STR00416## ##STR00417## wherein X is the same or different in each instance and is CR or N, with the proviso that not more than two symbols X per cycle are N; W is the same or different in each instance and is NR, O, or S; with the proviso that when the bridge V is bonded to CyC, one symbol X in the corresponding CyC group is C, to which the bridge V is bonded, and, when the bridge V is bonded to CyD, one symbol X in the corresponding CyD group is C, to which the bridge V is bonded; wherein the bond to the bridge V is via the position denoted by “o”.

11. A process for preparing the compound of claim 1 comprising reacting a free ligand with an iridium alkoxide of formula (52), an iridium ketoketonate of formula (53), an iridium halide of formula (54), or an iridium carboxylate of formula (55): ##STR00418## wherein Hal is F, Cl, Br, or I; and wherein the iridium reactants of formulae (52) through (55) are optionally in the form of a hydrate.

12. A formulation comprising at least one compound of claim 1 and at least one further compound.

13. The formulation of claim 12, wherein the at least one further compound is a matrix material and/or a solvent.

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

15. The electronic device of claim 14, wherein the electronic device is selected from the group consisting of organic electroluminescent devices, 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, light-emitting electrochemical cells, infrared sensors, oxygen sensors, and organic laser diodes.

16. The electronic device of claim 15, wherein the electronic device is an organic electroluminescent device, wherein the organic electroluminescent device comprises one or more emitting layers, and wherein the one or more emitting layers comprises a compound of formula (1).

17. The compound of claim 1, wherein R.sup.2 is a hydrocarbyl radical having 1 to 20 carbon atoms, wherein one or more hydrogen atoms is optionally replaced by F.

Description

EXAMPLES

(1) 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. In the case of compounds that can have multiple tautomeric forms, one tautomeric form is shown in a representative manner.

A: Synthesis of the Synthons S—Part 1

Example S1

(2) ##STR00255##

(3) Preparation according to Casey, Brian M. et al., Beilstein Journal of Organic Chemistry, 9, 1472-1479, 2013.

(4) To a suspension, cooled to 0° C., of 2.6 g (110 mmol) of NaH in 300 ml of THF are added dropwise, with good stirring, 10.3 g (100 mmol) of acetylacetone [123-54-6] (caution: evolution of hydrogen) and the mixture is stirred for a further 15 min. Then 42.0 ml (105 mmol) of n-BuLi, 2.5 M in n-hexane, are added dropwise and the mixture is stirred for another 15 min. Then a solution, cooled to 0° C., of 25.0 g (100 mmol) of 2-bromobenzyl bromide [3433-80-5] in 25 ml of THF is added all at once with very good stirring. The mixture is stirred for a further 10 min, the ice bath is removed, and the mixture is allowed to warm up to 15° C. over 30 min and hydrolysed by dropwise addition of 110 ml of 2N aqueous HCl. The aqueous phase is removed and extracted three times with 200 ml each time of ethyl acetate. The combined organic phases are washed twice with 300 ml each time of saturated sodium chloride solution and dried over magnesium sulfate. After the solvent has been removed under reduced pressure, the oily residue is chromatographed in an automatic column system (CombiFlash Torrent from A. Semrau). Yield: 12.4 g (46 mmol), 46%. Purity: about 97% by .sup.1H NMR.

(5) In an analogous manner, it is possible to prepare the following compounds:

(6) TABLE-US-00001 Ex. Reactants Product Yield S2 39% S3 37% S4 0 48% S5 64% S6 50% S7 61% S8 48% S9 0 50% S10 63% S11 59% S12 63% S13 60% S14 0 55% S15 49% S16 29% S17 46% S18 55% S19 0 57% S20 61% S21 56% S22 53% S23 46%

Example S50

(7) ##STR00300##

(8) A mixture of 26.9 g (100 mmol) of 2-(3-chloro-5-methoxyphenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane [929626-16-4], 31.0 g (100 mmol) of 2-(2′-bromo[1,1′-biphenyl]-4-yl)pyridine [1374202-35-3], 21.2 g (200 mmol) of sodium carbonate, 788 mg (3 mmol) of triphenylphosphine, 225 mg (1 mmol) of palladium(II) acetate, 300 ml of toluene, 100 ml of ethanol and 300 ml of water is heated under reflux for 48 h. After cooling, the mixture is extended with 300 ml of toluene, and the organic phase is removed, washed once with 500 ml of water and once with 500 ml of saturated sodium chloride solution, and dried over magnesium sulfate. After the solvent has been removed, the residue is chromatographed on silica gel (n-heptane/ethyl acetate, 2:1 v/v). Yield: 28.4 g (76 mmol), 76%. Purity: about 97% by .sup.1H NMR.

(9) In an analogous manner, it is possible to prepare the following compounds:

(10) TABLE-US-00002 Ex. Reactants Product Yield S51 01 02 80% S52 03 04 73% S53 05 06 75% S54 07 08 80% S55 09 0 77% S56 71%

Example S100

(11) ##STR00313##

(12) A mixture of 37.2 g (100 mmol) of S50, 31.0 g (100 mmol) of 5-(2-bromophenyl)-2-phenylpyridine [1989597-29-6], 21.2 g (200 mmol) of sodium carbonate, 1.23 g (3 mmol) of SPhos, 449 mg (2 mmol) of palladium(II) acetate, 300 ml of toluene, 100 ml of ethanol and 300 ml of water is heated under reflux for 16 h. After cooling, the mixture is extended with 300 ml of toluene, and the organic phase is removed, washed once with 500 ml of water and once with 500 ml of saturated sodium chloride solution, and dried over magnesium sulfate. After the solvent has been removed, the residue is chromatographed on silica gel (n-heptane/ethyl acetate, 2:1 v/v). Yield: 40.3 g (71 mmol), 71%. Purity: about 97% by .sup.1H NMR.

(13) In an analogous manner, it is possible to prepare the following compounds:

(14) TABLE-US-00003 Ex. Reactants Product Yield S101 68% S102 70% S103 74% S104 0 69% S105 75% S106 73% S107 67% S108 70%

Example S200

(15) ##STR00330##

(16) A mixture of 55.6 g (100 mmol) of S100 and 115.6 g (1 mol) of pyridinium hydrochloride [628-13-7] is heated to 200° C. on a water separator for 3 h, discharging the distillate from time to time. After cooling, 1000 ml of ice-water are added to the reaction mixture, crystallizing the product. The mixture is left to stand in a refrigerator overnight, and the crystals are filtered off with suction, washed with a little ice-water and dried under reduced pressure. Yield: 55.0 g (87 mmol), 87%; purity: about 97% by .sup.1H NMR.

(17) In an analogous manner, it is possible to prepare the following compounds:

(18) TABLE-US-00004 Ex. Reactant Product Yield S201 S101 90% S202 S102 88% S203 S103 85% S204 S104 85% S205 S105 91% S206 S106 90% S207 S107 86% S208 S108 88%

Example S300

(19) ##STR00339##

(20) To a solution, cooled to 0° C., of 55.6 g (100 mmol) of S200 in a mixture of 500 ml of dichloromethane and 100 ml of pyridine are added dropwise, with good stirring, 34 ml (200 mmol) of trifluoromethanesulfonic anhydride [358-23-6]. The reaction mixture is allowed to warm up to room temperature and stirred for a further 16 h, poured onto 1000 ml of ice-water while stirring and stirred for a further 10 min, the organic phase is removed and the aqueous phase is extracted three times with 300 ml each time of dichloromethane. The combined organic phases are washed twice with 300 ml each time of ice-water and once with 500 ml of saturated NaCl solution and dried over sodium sulfate. The wax obtained after removal of the dichloromethane under reduced pressure is recrystallized from acetonitrile. Yield: 60.5 g (88 mmol), 88%; purity: about 95% by .sup.1H NMR.

(21) In an analogous manner, it is possible to prepare the following compounds:

(22) TABLE-US-00005 Ex. Reactant Product Yield S301 S201 0 90% S302 S202 81% S303 S203 83% S304 S204 81% S305 S205 83% S306 S206 77% S307 S207 79% S308 S208 85%

Example S400

(23) ##STR00348##

(24) To a solution of 68.5 g (100 mmol) of S300 and bis(diphenylphosphino)palladium(II) dichloride x DCM in 500 ml of dioxane are added, with good stirring, 41.8 ml (300 mmol) triethylamine and then, in a dropwise manner, 29.0 ml (200 mmol) of 4,4,5,5-tetramethyl-[1,3,2]-dioxaborolane, and the mixture is heated under reflux for 16 h. After cooling, the mixture is concentrated to dryness under reduced pressure, and the oil is taken up in 500 ml of ethyl acetate, washed three times with 300 ml each time of water and once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate, and the desiccant is filtered off using a silica gel bed in an ethyl acetate slurry. The solvent is removed under reduced pressure and the residue is recrystallized twice from acetonitrile with addition of a little ethyl acetate. Yield: 49.7 g (75 mmol), 75%; purity: about 95% by .sup.1H NMR.

(25) In an analogous manner, it is possible to prepare the following compounds:

(26) TABLE-US-00006 Ex. Reactant Product Yield S401 S301 73% S402 S302 0 69% S403 S303 67% S404 S304 70% S405 S305 74% S406 S306 68% S407 S307 70% S408 S308 67%

B: Synthesis of the Ligands L

Example L1

(27) ##STR00357##

(28) A mixture of 66.3 g (100 mmol) of 2,2′-[5″-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′:2′,1″:3″,1′″:2′″,1″″-quinquephenyl]-4,4″″-diyl]bispyridine [1989597-72-9], 29.6 g (110 mmol) of S1, 31.8 g (300 mmol) of sodium carbonate, 1.23 g (3 mmol) of SPhos, 449 mg (2 mmol) of palladium(II) acetate, 300 ml of toluene, 100 ml of ethanol and 300 ml of water is heated under reflux for 18 h. After cooling, acetic acid is used to adjust the pH to 6-7, the organic phase is removed, the aqueous phase is extracted three times with 100 ml each time of toluene, and the combined organic phases are washed once with 300 ml of water and once with 500 ml of saturated sodium chloride solution and dried over sodium sulfate. After the solvent has been removed, the residue is chromatographed (CombiFlash Torrent from A. Semrau). Yield: 50.0 g (69 mmol), 69%; purity: about 97% by .sup.1H NMR.

(29) In an analogous manner, it is possible to prepare the following compounds:

(30) TABLE-US-00007 Ex. Reactants Product Yield L-Ref.1 58% L2 0 70% L3 [1989597-72-9] S22 64%

Example L100

(31) ##STR00363##

(32) Procedure analogous to example L1, except that, rather than 2,2′-[5″-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′:2′,1″:3″,1′″:2′″,1″″-quinquephenyl]-4,4″″-diyl]bispyridine [1989597-72-9], 3,3′-[5′-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′:3′,″-terphenyl]-2,2″-diyl]bis[6-phenylpyridine] [1989597-70-7] is used. Yield: 53.2 g (73 mmol), 73%; purity: about 97% by .sup.1H NMR.

(33) In an analogous manner, it is possible to prepare the following compounds:

(34) TABLE-US-00008 Ex. Reactants Product Yield L- Ref.2 54% L101 [1989597-70-7] S7 65% L102 68% L103 0 67% L104 61% L105 58%

Example L200

(35) ##STR00375##

(36) Procedure analogous to example L1, except that, rather than 2,2′-[5″-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-[1,1′:2′,1″:3″,1′″:2′″,1″″-quinquephenyl]-4,4″″-diyl]bispyridine [1989597-72-9], S400 is used. Yield: 53.0 g (72 mmol), 72%; purity: about 97% by .sup.1H NMR.

(37) In an analogous manner, it is possible to prepare the following compounds:

(38) TABLE-US-00009 Ex. Reactants Product Yield L- Ref.3 S400 [473758- 02-0] 56% L201 S401 S2 54% L202 S401 S3 57% L203 S402 S5 65% L204 S402 S23 0 67% L205 S403 S8 60% L206 S403 S19 62% L207 S403 S21 66% L208 S404 S9 65% L209 S404 S10 60% L210 S405 S13 57% L211 S405 S14 62% L212 S406 S15 70% L213 S407 S18 67% L214 S408 S19 0 59%

C: Preparation of the Metal Complexes

Example Ir(L1)

(39) ##STR00391##

(40) Variant A:

(41) A mixture of 7.25 g (10 mmol) of ligand L1, 4.90 g (10 mmol) of trisacetylacetonatoiridium(III) [15635-87-7] and 120 g of hydroquinone [123-31-9] is initially charged in a 1000 ml two-neck round-bottom flask with a glass-sheathed magnetic bar. The flask is provided with a water separator (for media of lower density than water) and an air condenser with argon blanketing. The flask is placed in a metal heating bath. The apparatus is purged with argon from the top via the argon blanketing system for 15 min, allowing the argon to flow out of the side neck of the two-neck flask. Through the side neck of the two-neck flask, a glass-sheathed Pt-100 thermocouple is introduced into the flask and the end is positioned just above the magnetic stirrer bar. Then the apparatus is thermally insulated with several loose windings of domestic aluminium foil, the insulation being run up to the middle of the riser tube of the water separator. Then the apparatus is heated rapidly with a heated laboratory stirrer system to 250-255° C., measured with the Pt-100 temperature sensor which dips into the molten stirred reaction mixture. Over the next 1 h, the reaction mixture is kept at 250-255° C., in the course of which a small amount of condensate is distilled off and collects in the water separator. After 1 h, the mixture is allowed to cool down to 190° C., the heating mantle is removed and then 100 ml of ethylene glycol are added dropwise. After cooling to 100° C., 400 ml of methanol are slowly added dropwise. The beige suspension thus obtained is filtered through a double-ended frit, and the beige solid is washed three times with 50 ml of methanol and then dried under reduced pressure. Crude yield: quantitative. The solid thus obtained is dissolved in 200 ml of dichloromethane and filtered through about 1 kg of silica gel in the form of a dichloromethane slurry (column diameter about 18 cm) with exclusion of air in the dark, leaving dark-coloured components at the start. The core fraction is cut out and concentrated on a rotary evaporator, with simultaneous continuous dropwise addition of MeOH until crystallization. After removal with suction, washing with a little MeOH and drying under reduced pressure, the orange product is purified further by continuous hot extraction five times with dichloromethane/acetonitrile 1:1 (v/v) (amount initially charged in each case about 200 ml, extraction thimble: standard Soxhlet thimbles made from cellulose from Whatman) with careful exclusion of air and light. The loss into the mother liquor can be adjusted via the ratio of dichloromethane (low boilers and good dissolvers):acetonitrile (high boilers and poor dissolvers). It should typically be 3-6% by weight of the amount used. Hot extraction can also be accomplished using other solvents such as toluene, xylene, ethyl acetate, butyl acetate, etc. Finally, the product is sublimed at 390° C. under high vacuum. Yield: 5.95 g (6.1 mmol), 61%; purity: >99.9% by HPLC.

(42) Variant B:

(43) Procedure analogous to Ir(L1) Variant A, except that 300 ml of ethylene glycol [111-46-6] are used rather than 120 g of hydroquinone and the mixture is stirred at 190° C. for 16 h. After cooling to 70° C., the mixture is diluted with 300 ml of ethanol, and the solids are filtered off with suction (P3), washed three times with 100 ml each time of ethanol and then dried under reduced pressure. Further purification is effected as described in Variant A. Yield: 6.35 g (6.5 mmol), 65%; purity: >99.9% by HPLC.

(44) Variant C:

(45) Procedure analogous to Ir(L1) Variant B, except that 3.53 g (10 mmol) of iridium(III) chloride x n H.sub.2O (n about 3) are used rather than 4.90 g (10 mmol) of trisacetylacetonatoiridium(III) [15635-87-7] and 300 ml of 2-ethoxyethanol/water (3:1, vv) rather than 120 g of hydroquinone, and the mixture is stirred under reflux for 30 h. After cooling, the solid is filtered off with suction (P3), washed three times with 30 ml each time of ethanol and then dried under reduced pressure. Further purification is effected as described in Variant B. Yield: 4.67 g (5.1 mmol), 51%; purity: >99.9% by HPLC.

(46) The metal complexes are typically obtained as a 1:1 mixture of the Λ and Δ isomers/enantiomers. The images of complexes adduced hereinafter typically show only one isomer. If ligands having three different sub-ligands are used, or chiral ligands are used as a racemate, the metal complexes derived are obtained as a diastereomer mixture. These can be separated by fractional crystallization or by chromatography, for example with an automatic column system (CombiFlash from A. Semrau). If chiral ligands are used in enantiomerically pure form, the metal complexes derived are obtained as a diastereomer mixture, the separation of which by fractional crystallization or chromatography leads to pure enantiomers. The separated diastereomers or enantiomers can be purified further as described above, for example by hot extraction.

(47) Diastereomer1 refers hereinafter to that diastereomer which shows the greater Rf on thin-film chromatography plates (TLC silica gel 60 F254 from Merck) with ethyl acetate as eluent; Diastereomer2 refers to that diastereomer which shows the smaller Rf.

(48) In an analogous manner, it is possible to prepare the following compounds:

(49) TABLE-US-00010 Product Ex. Ligand Variant/extractant* Yield Ir(L-Ref.1) L-Ref.1 Ir(L-Ref.1) 30% B Ir(L2) L2 Ir(L2) 63% B Ir(L3) L3 Ir(L3) 65% A/Toluene Ir(100) L100 60% Ir(L-Ref.2) L-Ref.2 Ir(L-Ref.2) 24% B Ir(L101) L101 Ir(L101) 57% A Ir(L102) L102 Ir(L102) 60% B/toluene Ir(L103) L103 Ir(L103) 66% C/toluene Ir(L104) L104 Ir(L104) 62% A Ir(L105) L105 Ir(L105) 58% A Ir1(L200) L200 24% Ir2(L200) L200 Ir2(L200) 27% A Diastereomer2 Ir1(L- L-Ref.3 Ir1(L-Ref.3) 10% Ref.3) B Diastereomer1 Ir2(L- L-Ref.3 Ir2(L-Ref.3) 13% Ref.3) B Diastereomer2 Ir(L201) L201 Ir(L201) 68% A Isomer mixture Ir1(L202) L202 Ir1(L202) 30% B Diasteromer1 Ir2(L202) L202 Ir2(L202) 28% B Diastereomer2 Ir1(L203) L203 Ir1(L203) 25% C Diastereomer1 Ir2(L203) L203 Ir2(L203) 29% C Diasteromer2 Ir1(L204) L204 Ir1(L204) 35% C Diastereomer1 Ir2L204) L204 Ir2L204) 23% C Diastereomer2 Ir1(L205) L205 Ir1(L205) 31% A Diastereomer1 Ir2L205) L205 Ir2L205) 33% A Diastereomer2 Ir1(L206) L206 Ir1(L206) 27% A Diastereomer1 Ir2L206) L206 Ir2L206) 34% A Diastereomer2 Ir1(L207) L207 Ir1(L207) 30% B Diastereomer1 Ir2L207) L207 Ir2L207) 35% B Diastereomer2 Ir1(L208) L208 Ir1(L208) 28% B Diastereomer1 Ir2L208) L208 Ir2L208) 31% B Diastereomer2 Ir1(L209) L209 Ir1(L209) 30% B Diastereomer1 Ir2L209) L209 Ir2L209) 30% B Diastereomer2 Ir1(L210) L210 Ir1(L210) 32% A Diastereomer1 Ir2L210) L210 Ir2L210) 27% A Diastereomer2 Ir1(L211) L211 Ir1(L211) 33% A Diastereomer1 Ir2L211) L211 Ir2L211) 30% A Diastereomer2 Ir1(L212) L212 Ir1(L212) 33% C Diastereomer1 Ir2L212) L212 Ir2L212) 29% C Diastereomer2 Ir1(L213) L213 Ir1(L213) 35% A Diastereomer1 Ir2L213) L213 Ir2L213) 31% A Diastereomer2 Ir1(L214) L214 Ir1(L214) 27% B Diastereomer1 Ir2L214) L214 Ir2L214) 23% B Diastereomer2 *if different

(50) Sublimation Temperatures and Rates:

(51) By comparison with the tripodal complexes having three phenylpyridine-like sub-ligands, the compounds of the invention sublime at lower temperatures and with higher sublimation rates (g/h) at a given sublimation temperature, as detailed in the table below. The exact temperatures and sublimation rates always depend on the exact pressure and the particular geometry of the sublimation apparatus used. The temperatures and sublimation rates are determined at a base pressure of about 10.sup.−5 mbar in the same apparatus in each case.

(52) TABLE-US-00011 Sublimation Sublimation rate at the temperature given sublimation temperature Complex [° C.] [g/h] Ir-Ref. 1 ~440 0.6 Ir-Ref. 2 ~440 0.5 Ir-Ref. 3 ~420 1.0 Ir(L1) ~390 1.4 Ir(L100) ~390 1.3 Ir(L200) ~380 1.8

Example: Production of the OLEDs

(53) 1) Vacuum-Processed Devices:

(54) OLEDs of the invention and OLEDs according to the prior art are produced by a general method according to WO 2004/058911, which is adapted to the circumstances described here (variation in layer thickness, materials used).

(55) In the examples which follow, the results for various OLEDs are presented. Cleaned glass plaques (cleaning in Miele laboratory glass washer, Merck Extran detergent) coated with structured ITO (indium tin oxide) of thickness 50 nm are pretreated with UV ozone for 25 minutes (PR-100 UV ozone generator from UVP) and, within 30 min, for improved processing, coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS™ P VP Al 4083 from Heraeus Precious Metals GmbH Deutschland, spun on from aqueous solution) and then baked at 180° C. for 10 min. These coated glass plaques form the substrates to which the OLEDs are applied. The OLEDs basically have the following layer structure: substrate/hole transport layer 1 (HTL1) consisting of HTM doped with 5% NDP-9 (commercially available from Novaled), 20 nm/hole transport layer 2 (HTL2)/optional electron blocker layer (EBL)/emission layer (EML)/optional hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer of thickness 100 nm.

(56) First of all, vacuum-processed OLEDs are described. For this purpose, all the materials are applied by thermal vapour deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as M1:M2:Ir(L2) (55%:35%:10%) mean here that the material M1 is present in the layer in a proportion by volume of 55%, M2 in a proportion by volume of 35% and Ir(L1) in a proportion by volume of 10%. Analogously, the electron transport layer may also consist of a mixture of two materials. The exact structure of the OLEDs can be found in Table 2. The materials used for production of the OLEDs are shown in Table 4.

(57) The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in lm/W) and the external quantum efficiency (EQE, measured in percent) as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian emission characteristics, and also the lifetime are determined. The electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated therefrom. The lifetime LT80 is defined as the time after which the luminance drops to 80% of the starting luminance in the course of operation with a constant current of 40 mA/cm.sup.2.

(58) Use of Compounds of the Invention as Emitter Materials in Phosphorescent OLEDs

(59) One use of the compounds of the invention is as phosphorescent emitter materials in the emission layer in OLEDs. The iridium compounds according to Table 4 are used as a comparison according to the prior art. The results for the OLEDs are collated in Table 2.

(60) TABLE-US-00012 TABLE 1 Structure of the OLEDs HTL2 EBL EML HBL ETL Ex. thickness thickness thickness thickness thickness Ref.-D1 HTM — M1:Ir-Ref. 1 ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D2 HTM — M1:Ir-Ref. 2 ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D3 HTM — M1:I Ir-Ref. 3 ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D4 HTM — M1:M2:Ir-Ref. 1 ETM1 ETM1:ETM2 40 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D5 HTM — M1:M2:Ir-Ref. 2 ETM1 ETM1:ETM2 40 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D6 HTM — M1:Ir(L-Ref. 1) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D7 HTM — M1:Ir(L-Ref. 2) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm Ref.-D8 HTM — M1:I Ir1 (L-Ref. 3) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm D1 HTM — M1:Ir(L1) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm D2 HTM — M1:Ir(L100) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm D3 HTM — M1:Ir(L200) ETM1 ETM1:ETM2 40 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm D4 HTM — M1:M2:Ir(I1) ETM1 ETM1:ETM2 40 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm D5 HTM — M1:M2:Ir(L100) ETM1 ETM1:ETM2 40 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm D6 HTM — M1:M2:Ir(L200) ETM1 ETM1:ETM2 40 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm D7 HTM EBM M1:M2:Ir(L200) ETM1 ETM1:ETM2 30 nm 10 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm

(61) TABLE-US-00013 TABLE 2 Results for the vacuum-processed OLEDs EQE (%) @ Voltage (V) CIE x/y @ LD80 (h) @ Ex. 1000 cd/m.sup.2 @ 1000 cd/m.sup.2 1000 cd/m.sup.2 40 mA/cm.sup.2 Ref.-D1 20.3 3.1 0.34/0.62 220 Ref.-D2 20.7 3.0 0.40/0.58 240 Ref.-D3 16.0 3.1 0.38/0.57 250 Ref.-D4 20.6 3.1 0.34/0.62 250 Ref.-D5 21.0 3.1 0.39/0.59 270 Ref.-D6 19.9 3.2 0.37/0.60 150 Ref.-D7 20.1 3.3 0.45/0.52 130 Ref.-D8 20.4 3.2 0.43/0.53 160 D1 22.6 2.9 0.39/0.59 220 D2 22.9 3.0 0.43/0.55 250 D3 23.4 3.0 0.44/0.54 280 D4 22.2 2.9 0.39/0.59 280 D5 22.5 3.0 0.43/0.55 310 D6 23.0 3.0 0.44/0.54 300 D7 22.9 3.0 0.44/0.54 320

(62) Solution-Processed Devices:

(63) From Soluble Functional Materials of Low Molecular Weight

(64) The compounds of the invention may also be processed from solution and in that case lead to OLEDs which are much simpler in terms of process technology compared to vacuum-processed OLEDs, but nevertheless have good properties. The production of such components is based on the production of polymeric light-emitting diodes (PLEDs), which has already been described many times in the literature (for example in WO 2004/037887). The structure is composed of substrate/ITO/hole injection layer (60 nm)/interlayer (20 nm)/emission layer (60 nm)/hole blocker layer (10 nm)/electron transport layer (40 nm)/cathode. For this purpose, substrates from Technoprint (soda-lime glass) are used, to which the ITO structure (indium tin oxide, a transparent conductive anode) is applied. The substrates are cleaned in a cleanroom with DI water and a detergent (Deconex 15 PF) and then activated by a UV/ozone plasma treatment. Thereafter, likewise in a cleanroom, a 20 nm hole injection layer is applied by spin-coating. The required spin rate depends on the degree of dilution and the specific spin-coater geometry. In order to remove residual water from the layer, the substrates are baked on a hotplate at 200° C. for 30 minutes. The interlayer used serves for hole transport; in this case, HL-X092 from Merck is used. The interlayer may alternatively also be replaced by one or more layers which merely have to fulfil the condition of not being leached off again by the subsequent processing step of EML deposition from solution. For production of the emission layer, the triplet emitters of the invention are dissolved together with the matrix materials in toluene or chlorobenzene. The typical solids content of such solutions is between 16 and 25 g/I when, as here, the layer thickness of 60 nm which is typical of a device is to be achieved by means of spin-coating. The solution-processed devices of type 1 contain an emission layer composed of M3:M4:IrL (20%:60%:20%), and those of type 2 contain an emission layer composed of M3:M4:IrLa:IrLb (30%:34%:30%:6%); in other words, they contain two different iridium complexes. The emission layer is spun on in an inert gas atmosphere, argon in the present case, and baked at 160° C. for 10 min. Vapour-deposited above the latter are the hole blocker layer (10 nm ETM1) and the electron transport layer (40 nm ETM1 (50%)/ETM2 (50%)) (vapour deposition systems from Lesker or the like, typical vapour deposition pressure 5×10.sup.−6 mbar). Finally, a cathode of aluminium (100 nm) (high-purity metal from Aldrich) is applied by vapour deposition. In order to protect the device from air and air humidity, the device is finally encapsulated and then characterized. The OLED examples cited are yet to be optimized; Table 3 summarizes the data obtained.

(65) TABLE-US-00014 TABLE 3 Results with materials processed from solution Emitter EQE (%) Voltage (V) LD50 (h) Ex. Device 1000 cd/m.sup.2 1000 cd/m.sup.2 CIE x/y 1000 cd/m.sup.2 Sol-Ref. 1 Ir-Ref. 4 20.6 5.2 0.36/0.61 220000 Type 1 Sol-Ref. 2 Ir-Ref. 5 21.4 5.0 0.31/0.62 11000 Type 1 Sol-D1 Ir(L2) 22.3 5.1 0.38/0.59 230000 Type 1 Sol-D2 Ir(L202) 21.4 4.7 0.68/0.32 320000 Ir(L213) Type 2

(66) TABLE-US-00015 TABLE 4 Structural formulae of the materials used 00 01 02 03 04 05 06