HETEROCYCLIC SPIRO COMPOUNDS

Abstract

The present invention relates to spiro compounds containing electron-conducting groups and to electronic devices, in particular organic electroluminescent devices, comprising these compounds.

Claims

1-31. (canceled)

32. A mixture comprising at least one compound of the formula (I), ##STR00517## wherein X is O, S, or C(R.sup.1).sub.2; Ar is on each occurrence, identically or differently, an aryl group having 6 to 40 C atoms or a heteroaryl group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.1; R.sup.1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, C(═O)Ar.sup.1, P(═O)(Ar.sup.1).sub.2, S(═O)Ar.sup.1, S(═O).sub.2Ar.sup.1, CN, NO.sub.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, OSO.sub.2R.sup.2, a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.2, and wherein one or more non-adjacent CH.sub.2 groups are optionally replaced by R.sup.2C═CR.sup.2, C≡C, Si(R.sup.2).sub.2, Ge(R.sup.2).sub.2, Sn(R.sup.2).sub.2, C═O, C═S, C═Se, P(═O)(R.sup.2), SO, SO.sub.2, O, S, or CONR.sup.2, and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2, or an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2, or a combination of these systems; and wherein two or more adjacent substituents R.sup.1 optionally define a mono- or polycyclic, aliphatic or aromatic ring system with one another; R.sup.2 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, CHO, C(═O)Ar.sup.1, P(═O)(Ar.sup.1).sub.2, S(═O)Ar.sup.1, S(═O).sub.2Ar.sup.1, CN, NO.sub.2, Si(R.sup.3).sub.3, B(OR.sup.3).sub.2, OSO.sub.2R.sup.3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy, or thioalkoxy group having 3 to 40 C atoms, each of which is optionally substituted by one or more radicals R.sup.3, wherein one or more non-adjacent CH.sub.2 groups are optionally replaced by C≡C, Si(R.sup.3).sub.2, Ge(R.sup.3).sub.2, Sn(R.sup.3).sub.2, C═O, C═S, C═Se, P(═O)(R.sup.3), SO, SO.sub.2, O, S, or CONR.sup.3, and wherein one or more H atoms are optionally replaced by D, F, Cl, Br, I, CN, or NO.sub.2, or a combination of these systems; and wherein two or more adjacent substituents R.sup.2 optionally define a mono- or polycyclic, aliphatic or aromatic ring system with one another; Ar.sup.1 is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2; wherein two radicals Ar.sup.1 bonded to the same phosphorus atom are also optionally linked to one another by a single bond or a bridge selected from the group consisting of B(R.sup.3), C(R.sup.3).sub.2, Si(R.sup.3).sub.2, C═O, C═NR.sup.3, C═C(R.sup.3).sub.2, O, S, S═O, SO.sub.2, N(R.sup.3), P(R.sup.3), and P(═O)R.sup.3; R.sup.3 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms of the hydrocarbon radical are optionally replaced by F; and wherein two or more adjacent substituents R.sup.3 optionally define a mono- or polycyclic, aliphatic or aromatic ring system with one another; n is on each occurrence, identically or differently, 0, 1, 2, 3, or 4; m is on each occurrence, identically or differently, 0, 1, 2, or 3; o is on each occurrence, identically or differently, 0, 1, or 2; p, q, r, and u are on each occurrence, identically or differently, 0 or 1; s and t are, on each occurrence, 0; E is an electron-transporting group, which is optionally substituted by one or more radicals R.sup.1, R.sup.a is, independently, H, D, or F; R.sup.b is, independently, H, D, or F; with the proviso that the compound of formula (I) contains only one electron-transporting group E; the sum of all indices m, s and, t is less than 7; the sum of all indices n, q and, u is less than 9; the sum of the indices r and o is less than 3; and at least one further compound wherein the further compound is a matrix material.

33. The mixture according to claim 32, wherein p is 0, so that E is bonded directly to the benzofuran or spiro group.

34. The mixture according to claim 32, wherein at least one radical containing the electron-transporting group E is bonded in position 1, 3, 4, 5, 6, or 8 of the spirobifluorene skeleton.

35. The mixture according to claim 32, wherein the electron-transporting group E is a heteroaryl group having 5 to 60 aromatic ring atoms.

36. The mixture according to claim 32, wherein the electron-transporting group E comprises at least one structure selected from the group consisting of triazines, pyrimidines, pyrazines, imidazoles, benzimidazoles, and pyridines.

37. The mixture according to claim 32, wherein the electron-transporting group E comprises at least one structure selected from the group consisting of formulae (E-1) through (E-10): ##STR00518## wherein the dashed bond marks the bonding position, Q′ is on each occurrence, identically or differently, CR.sup.1 or N, and Q″ is NR.sup.1, O, or S, and wherein at least one Q′ is N and/or at least one Q″ is NR.sup.1.

38. The mixture according to claim 35, wherein the electron-transporting group E comprises at least one structure selected from the group consisting of formulae (E-11) through (E-19): ##STR00519## wherein the dashed bond marks the bonding position.

39. The mixture according to claim 37, wherein at least one of the radicals R.sup.1 in the structures of formulae (E-1) through (E-10) is an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is optionally substituted by one or more radicals R.sup.2.

40. The mixture according to claim 32, wherein the compound comprises a compound of formulae (II), (III), (IV), (V), (VI), and/or (VII): ##STR00520## ##STR00521##

41. The mixture according to claim 32, wherein the matrix material has hole-transporting properties.

42. The mixture according to claim 32, wherein the hole transporting compound is a carbazole, bridged carbazoles biscarbazole, indenocarbazole and indolocarbazole derivative.

43. The mixture according to claim 32, wherein the carbazole derivative is a biscarbazole.

44. The mixture according to claim 32, wherein the compound of formula (I) is selected from the group of compounds ##STR00522## ##STR00523## ##STR00524## ##STR00525## ##STR00526## ##STR00527## ##STR00528## ##STR00529## ##STR00530## ##STR00531## ##STR00532## ##STR00533## ##STR00534## ##STR00535## ##STR00536## ##STR00537## ##STR00538## ##STR00539## ##STR00540## ##STR00541## ##STR00542## ##STR00543## ##STR00544## ##STR00545## ##STR00546## ##STR00547## ##STR00548## ##STR00549## ##STR00550## ##STR00551## ##STR00552## ##STR00553## ##STR00554## ##STR00555## ##STR00556## ##STR00557## ##STR00558## ##STR00559## ##STR00560## ##STR00561## ##STR00562## ##STR00563## ##STR00564## ##STR00565## ##STR00566## ##STR00567## ##STR00568##

45. An organic electroluminescent device comprising the mixture according to claim 32.

46. An organic electroluminescent device comprising the mixture according to claim 42.

47. An organic electroluminescent device comprising the mixture according to claim 43.

48. An organic electroluminescent device comprising the mixture according to claim 32 wherein the mixture is employed in an emitting layer, in combination with a phosphorescent dopant.

49. An organic electroluminescent device comprising the mixture according to claim 42 wherein the mixture is employed in an emitting layer, in combination with a phosphorescent dopant.

50. An organic electroluminescent device comprising the mixture according to claim 43 wherein the mixture is employed in an emitting layer, in combination with a phosphorescent dopant.

Description

EXAMPLES

[0193] The following syntheses are carried out, unless indicated otherwise, under a protective-gas atmosphere in dried solvents. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The numbers in square brackets for chemical compounds which are known from the literature relate to the CAS numbers.

A-1) Example 1: Synthesis of Compounds (1-1) to (1-19)

[0194] ##STR00226##

Synthesis of 4-(2-bromophenyl)dibenzofuran Int-1

[0195] 100 g (462 mmol) of dibenzofuran-4-boronic acid, 106 g (439 mmol) of 1,2-dibromobenzene and 10.7 g (9.2 mmol) of Pd(Ph.sub.3P).sub.4 are suspended in 980 ml of dioxane. 979 ml of 2 M potassium carbonate solution are slowly added to this suspension, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is separated off, filtered through silica gel, washed three times with 200 ml of water and subsequently evaporated to dryness. The residue is purified by chromatography on silica gel. Yield: 87 g (270 mmol), 58% of theory, purity according to HPLC>98%.

[0196] The following compounds are prepared analogously to the described synthesis of compound Int-1:

TABLE-US-00002 Starting Starting material 1 material 2 Product Yield Int-2 [00227] [00228] [00229] 62% Int-3 [00230] [00231] [00232] 52% Int-4 [00233] [00234] [00235] 55% Int-5 [00236] [00237] [00238] 35% Int-6 [00239] [00240] [00241] 40% Int-7 [00242] [00243] [00244] 43% Int-8 [00245] [00246] [00247] 42% Int-9 [00248] [00249] [00250] 40%

[0197] The following compounds are prepared analogously to the described synthesis of compound Int-29:

TABLE-US-00003 Starting Starting material 1 material 2 Product Yield Int-10 [00251] [00252] [00253] 80% Int-11 [00254] [00255] [00256] 70% Int-12 [00257] [00258] [00259] 70% Int-13 [00260] [00261] [00262] 72% Int-14 [00263] [00264] [00265] 75% Int-15 [00266] [00267] [00268] 80% Int-16 [00269] [00270] [00271] 75% Int-17 [00272] [00273] [00274] 73% Int-18 [00275] [00276] [00277] 70% Int-19 [00278] [00279] [00280] 75% Int-20 [00281] [00282] [00283] 65% Int-21 [00284] [00285] [00286] 58% Int-22 [00287] [00288] [00289] 80% Int-23 [00290] [00291] [00292] 72% Int-24 [00293] [00294] [00295] 75% Int-25 [00296] [00297] [00298] 67% Int-26 [00299] [00300] [00301] 59% Int-27 [00302] [00303] [00304] 47% Int-28 [00305] [00306] [00307] 51%

Synthesis of Compound (1-1)

[0198] ##STR00308##

[0199] 15.5 g (32 mmol) of bromospiro derivative, 15.2 g (35 mmol) of 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl)phenyl]-1,3,5-triazine dibromodibenzofuran, 31 ml (63 mmol) of Na.sub.2CO.sub.3 (2 M solution) are suspended in 120 ml of toluene and 120 ml of ethanol. 0.73 g (0.63 mmol) of Pd(PPh.sub.3).sub.4 is added to this suspension, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is separated off, filtered through silica gel, washed three times with 200 ml of water and subsequently evaporated to dryness. The residue is recrystallised from toluene and from dichloromethane/isopropanol and finally sublimed in a high vacuum (p=5×10.sup.−5 mbar). The purity is 99.9% (HPLC). The yield of compound (1-1) is 16.6 g (23 mmol), corresponding to 73% of theory.

[0200] Synthesis of compounds (1-2) to (1-19) The following compounds (1-2) to (1-19) are also prepared analogously to the synthesis of compound (1-1) described in Example 1:

TABLE-US-00004 Starting material 1 Starting material 2 Product Yield 1- 2 [00309] [00310] [00311] 74% 1- 3 [00312] [00313] [00314] 81% 1- 4 [00315] [00316] [00317] 84% 1- 5 [00318] [00319] [00320] 67% 1- 6 [00321] [00322] [00323] 72% 1- 7 [00324] [00325] [00326] 82% 1- 8 [00327] [00328] [00329] 77% 1- 9 [00330] [00331] [00332] 71% 1- 10 [00333] [00334] [00335] 81% 1- 11 [00336] [00337] [00338] 72% 1- 12 [00339] [00340] [00341] 70% 1- 13 [00342] [00343] [00344] 80% 1- 14 [00345] [00346] [00347] 76% 1- 15 [00348] [00349] [00350] 70% 1- 16 [00351] [00352] [00353] 66% 1- 17 [00354] [00355] [00356] 72% 1- 18 [00357] [00358] [00359] 76% 1- 19 [00360] [00361] [00362] 77%

[0201] Compound 1-19 can alternatively also be prepared in accordance with the following scheme, in which the unsubstituted benzimidazoleboronic acid is employed in order to obtain compound 1-19a. Step (I) here is carried out analogously to those in the syntheses of compounds 1-1 to 1-19.

##STR00363##

[0202] In step (II), the product from step (I) is reacted with iodobenzene. To this end, 26 g (50 mmol) of compound 1-19a, 560 mg (25 mmol) of Pd(OAc).sub.2, 19.3 g (118 mmol) of CuI, 20.8 g (100 mmol) of iodobenzene are suspended in 300 ml of degassed DMF under protective gas, and the reaction mixture is heated under reflux at 140° C. for 24 h. After the mixture has been cooled, the solvent is removed in vacuo, the residue is dissolved in dichloromethane, and water is added. The organic phase is then separated off and filtered through silica gel. The product is purified by means of column chromatography on silica gel with toluene/heptane (1:2) and finally sublimed in a high vacuum (p=5×10.sup.−7 mbar) (purity 99.9%). The yield is 18.5 g (30 mmol), corresponding to 62% of theory.

A-2) Example 2: Synthesis of Compounds (2-1) to (2-4)

Synthesis of Intermediate Int-29

[0203] ##STR00364##

[0204] 31 g (90 mmol) of 4-(2-bromophenyl)dibenzofuran is initially introduced in 300 ml of THF at −78° C. At this temperature, 40 ml of BuLi (2 M in hexane) are added dropwise. After 1 hour, 16.9 g (94 mmol) of fluoren-9-one in 200 ml of THF are added dropwise. The batch is left to stir overnight at room temperature, added to ice-water and extracted with dichloromethane. The combined organic phases are washed with water and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is, without further purification, heated under reflux at 100° C. overnight with 94 ml of HCl and 1074 ml of AcOH. After cooling, the precipitated solid is filtered off with suction, washed once with 100 ml of water, three times with 100 ml of ethanol each time and finally recrystallised from heptane. Yield: 23.1 g (57 mmol), 58%; purity about 98% according to 1H-NMR.

Synthesis of Compounds (Int-30) to (Int-32)

[0205] ##STR00365##

[0206] 15.0 g (36.9 mmol) of a Spiro derivative are dissolved in 150 ml of AcOH, and 5.7 g (29 mmol) of bromine dissolved in 20 ml of AcOH are added in portions at room temperature. When the addition is complete, the mixture is heated to 50-60° C., and, when the reaction is complete, water and ethyl acetate are added, and the organic phase is separated off, dried and evaporated. The crude product is subsequently washed by stirring a number of times with hot MeOH/heptane (1:1). Yield: 14.3 g (80%) of the bromospiro derivative Int-30.

[0207] The following brominated compounds are prepared analogously:

TABLE-US-00005 Bromination Starting material 1 reagent Product Yield Int-31 [00366] Br/AcOH [00367] 58% Int-32 [00368] Br/AcOH [00369] 55%

Synthesis of Compounds (Int-33) to (Int-40)

[0208] ##STR00370##

[0209] n-Butyllithium (2.5 M in hexane, 19.7 ml, 49.2 mmol) is added to a solution of 8.0 g (19.7 mmol) of a spiro derivative and 2.93 ml (19.7 mmol) of TMEDA in 100 ml of dried tetrahydrofuran at 0° C. at such a rate that the temperature does not rise above 10° C., and the mixture is subsequently stirred at room temperature for 4 h. The reaction mixture is then cooled to −78° C., chlorotrimethylsilane (7.51 ml, 58.0 mmol) is added, and the mixture is stirred overnight, during which the reaction mixture is allowed to warm to room temperature. The reaction mixture is filtered through a little silica gel and evaporated in a rotary evaporator. The oily residue is dissolved in 100 ml of dried dichloromethane, boron tribromide (2.24 ml, 23.6 mmol) is added, and the mixture is stirred overnight. When the reaction is complete, the reaction mixture is added to ice. The organic phase is separated off, and the aqueous phase is extracted with ethyl acetate. The combined organic phases are dried and evaporated. The cloudy, slightly brownish crude product is reacted further without further purification. Yield: 9.3 g (105%).

[0210] The following borylated compounds are prepared analogously. Isomers are separated by chromatography as corresponding pinacol esters:

TABLE-US-00006 Starting material 1 Reagent Product 1 Product 2 Int-32- 33 [00371] BuLi/ BBr3 [00372] [00373] Int-34- 35 [00374] BuLi/ BBr3 [00375] [00376] Int-36- 37 [00377] BuLi/ BBr3 [00378] [00379] Int-38- 39 [00380] BuLi/ BBr3 [00381] [00382] Int-40 [00383] BuLi/ BBr3 [00384]

Synthesis of Compounds (2-1) to (2-4)

[0211] ##STR00385##

[0212] 39 g (81 mmol) of a bromospiro derivative, 115 g (406 mmol) of 2-phenyl-1-benzimidazole, 22.4 g (162 mmol) of potassium carbonate, 1.84 g (8.1 mmol) of 1,3-di(2-pyridyl)-1,3-propanedione, 1.55 g (8.1 mmol) of copper iodide and 1000 ml of DMF are heated under reflux for 30 h. The reaction mixture is subsequently evaporated to dryness in a rotary evaporator. The residue is dissolved in THF and filtered through a short silica-gel bed, and the solvent is then removed in vacuo. The solid is subsequently recrystallised from heptane/THF and extracted with hot heptane/toluene over aluminium oxide. The solid which precipitated out on cooling is filtered off and dried. The yield of compound (2-1) is 36 g (60 mmol), 75%.

[0213] The following compounds (2-2) to (2-4) are also prepared analogously to the synthesis of compound (2-1) described in Example 2:

TABLE-US-00007 Starting Starting material 1 material 2 Product Yield 2-2 [00386] [00387] [00388] 82% 2-3 [00389] [00390] [00391] 64% 2-4 [00392] [00393] [00394] 68%

A-3) Example 3: Synthesis of Compounds 3-1 to 3-5

[0214] ##STR00395##

[0215] 110 ml (276 mmol) of n-butyllithium (2.5 M in hexane) are added dropwise to a solution, cooled to −78° C., of 137 g (270 mmol) of bromospiro derivative in 1500 ml of THF. The reaction mixture is stirred at −78° C. for 30 min. The mixture is allowed to come to room temperature, re-cooled to −78° C., and a mixture of 50 ml (270 mmol) of chlorodiphenylphosphine is then added rapidly, and the mixture is stirred at −70° C. for a further 3 hours. After the mixture has warmed to −10° C., it is hydrolysed using 135 ml of 2 N hydro-chloric acid. The organic phase is separated off, washed with water, dried over sodium sulfate and evaporated to dryness. The residue is dissolved in 300 ml of CH.sub.2Cl2 and stirred with 270 ml of 30% hydrogen peroxide solution at room temperature for 12 hours. The organic phase is separated off and evaporated, the colourless solid is filtered off with suction, washed with n-heptane and dried in vacuo and recrystallised from dichloromethane/toluene and finally sublimed in a high vacuum (p=5×10.sup.−5 mbar). The purity is 99.9% (HPLC). The yield of compound (3-1) is 119 g (191 mmol), corresponding to 70% of theory.

[0216] The following compounds are obtained analogously:

TABLE-US-00008 Starting material 1 Starting material 2 Product Yield 3-2 [00396] [00397] [00398] 72% 3-3 [00399] [00400] [00401] 69% 3-4 [00402] [00403] [00404] 72% 3-5 [00405] [00406] [00407] 73%

A-4) Example 4: Synthesis of Compounds 4-1 to 4-18

Synthesis of Intermediate Int-41

[0217] ##STR00408##

[0218] 50 g (103 mmol) of the bromospirofluorene derivative, 32 g (123 mmol) of bis(pinacolato)diborane and 30 g (309 mmol) of potassium acetate are suspended in 800 ml of dioxane. 2.5 g (3.09 mmol) of 1,1-bis(diphenyl-phosphino)ferrocenepalladium(II) dichloride complex with DCM are added to this suspension. The reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is separated off, washed three times with 400 ml of water and subsequently evaporated to dryness. The residue is recrystallised from toluene (52 g, 95% yield).

[0219] The following compounds are prepared analogously:

TABLE-US-00009 Starting material 1 Product Yield Int-42 [00409] [00410] 90% Int-43 [00411] [00412] 80% Int-44 [00413] [00414] 88% Int-45 [00415] [00416] 88% Int-46 [00417] [00418] 91% Int-47 [00419] [00420] 85% Int-48 [00421] [00422] 89%

Synthesis of Compound (4-1)

[0220] ##STR00423##

[0221] 24.6 g (46.3 mmol) of spirofluorenepinacolboronic ester derivative and 20.0 g (46.3 mmol) of chlorine derivative are suspended in 300 ml of dioxane and 14.1 g of caesium fluoride (92.6 mmol). 4.1 g (5.56 mmol) of bis(tricyclohexylphosphine)palladium dichloride are added to this suspension, and the reaction mixture is heated under reflux for 24 h. After cooling, the organic phase is separated off, filtered through silica gel, washed three times with 100 ml of water and subsequently evaporated to dryness. After the crude product has been filtered through silica gel with toluene, the residue which remains is recrystallised from heptane/toluene and finally sublimed in a high vacuum. The purity is 99.9%. The yield is 29.7 g (80% of theory).

Synthesis of Compounds (4-2) to (4-18)

[0222] The following compounds (4-2) to (4-18) are also prepared analogously to the synthesis of compound (4-1) described above:

TABLE-US-00010 Starting material 1 Starting material 2 Product Yield 4-2 [00424] [00425] [00426] 78% 4-3 [00427] [00428] [00429] 71% 4-4 [00430] [00431] [00432] 80% 4-5 [00433] [00434] [00435] 83% 4-6 [00436] [00437] [00438] 69% 4-7 [00439] [00440] [00441] 72% 4-8 [00442] [00443] [00444] 76% 4-9 [00445] [00446] [00447] 74% 4-10 [00448] [00449] [00450] 73% 4-11 [00451] [00452] [00453] 76% 4-12 [00454] [00455] [00456] 74% 4-13 [00457] [00458] [00459] 71% 4-14 [00460] [00461] [00462] 68% 4-15 [00463] [00464] [00465] 82% 4-16 [00466] [00467] [00468] 83% 4-17 [00469] [00470] [00471] 78% 4-18 [00472] [00473] [00474] 86%

A-5) Example 5: Synthesis of Compounds 5-1 to 5-5

[0223] ##STR00475##

[0224] 330 ml of a phenylmagnesium bromide solution (1.0 molar in THF) were added over the course of 15 min. to a suspension of 48.5 g (100 mmol) of bromospirofluorene derivative in 800 ml of THF at room temperature. The mixture was subsequently stirred at room temperature for a further 30 min. and under reflux for 5 h. After cooling, 100 ml of 5 N HCl and 100 ml of ethanol were added, and the mixture was again heated under reflux for 16 h. After cooling, the aqueous phase was separated off, and the organic phase was evaporated to dryness. The residue was taken up in 1000 ml of dichloromethane and washed five times with 500 ml of water each time.

[0225] After drying over magnesium sulfate, the organic phase was evaporated to dryness. The residue was recrystallised seven times from DMSO (about 3 ml/g) and dried in vacuo and recrystallised from dichloromethane/toluene and finally sublimed in a high vacuum (p=5×10.sup.−5 mbar). The purity is 99.9% (HPLC). The yield of compound (1-1) is 40 g (68 mmol), corresponding to 70% of theory.

Synthesis of Compounds (5-2) to (5-5)

[0226] The following compounds (5-2) to (5-5) are also prepared analogously to the synthesis of compound (5-1) described above:

TABLE-US-00011 Starting material 1 Starting material 2 Product Yield 5-2 [00476] [00477] [00478] 69% 5-3 [00479] [00480] [00481] 65% 5-4 [00482] [00483] [00484] 72% 5-5 [00485] [00486] [00487] 79%

[0227] Production of the OLEDs

[0228] The data of various OLEDs are presented in the following Examples V1 to E15 (see Tables 1 and 2).

[0229] Pre-treatment for Examples V1 to E15: Glass plates coated with structured ITO (indium t in oxide) in a thickness of 50 nm are 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, Germany, applied by sp in coating from aqueous solution) for improved processing. These coated glass plates form the substrates to which the OLEDs are applied.

[0230] The OLEDs have in principle the following layer structure: substrate/hole-transport layer (HTL)/optional interlayer (IL)/electron-blocking layer (EBL)/emission layer (EML)/optional hole-blocking layer (HBL)/electron-transport layer (ETL)/optional electron-injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer with a thickness of 100 nm. The precise structure of the OLEDs is shown in Table 1. The materials required for the production of the OLEDs are shown in Table 3.

[0231] All materials are applied by thermal vapour deposition in a vacuum chamber. The emission layer here always consists of at least one matrix material (host material) and an emitting dopant (emitter), which is admixed with the matrix material or matrix materials in a certain proportion by volume by co-evaporation. An expression such as IC1:IC3:TEG1 (55%:35%:10%) here means that material 101 is present in the layer in a proportion by volume of 55%, IC3 is present in the layer in a proportion of 35% and TEG1 is present in the layer in a proportion of 10%. Analogously, the electron-transport layer may also consist of a mixture of two materials.

[0232] The OLEDs are characterised by standard methods. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/W) and the external quantum efficiency (EQE, measured in percent) as a function of the luminous density, calculated from current/voltage/luminous density characteristic lines (IUL characteristic lines) assuming Lambert emission characteristics, are determined. The electroluminescence spectra are determined at a luminous density of 1000 cd/m.sup.2, and the CIE 1931 x and y colour coordinates are calculated therefrom. The term U1000 in Table 2 denotes the voltage required for a luminous density of 1000 cd/m.sup.2. CE1000 and PE1000 denote the current and power efficiency respectively which are achieved at 1000 cd/m.sup.2. Finally, EQE1000 denotes the external quantum efficiency at an operating luminous density of 1000 cd/m.sup.2.

[0233] The data of the various OLEDs are summarised in Table 2. Examples V1 and V2 are comparative examples in accordance with the prior art, Examples E1 to E15 show data of OLEDs according to the invention.

[0234] Some of the examples are explained in greater detail below in order to illustrate the advantages of the OLEDs according to the invention.

[0235] Use of Mixtures According to the Invention in the Emission Layer of Phosphorescent OLEDs

[0236] The materials according to the invention give rise to significant improvements in the voltage and external quantum efficiency compared with the prior art when used as matrix materials in phosphorescent OLEDs. The use of compounds 1-18 according to the invention in combination with the red-emitting dopant TER1 enables an increase of about 20% to be achieved in the external quantum efficiency compared with the prior art SdT1 (Examples V1 and E2).

[0237] Use of Compounds According to the Invention as Electron-Transport Materials

[0238] Compared with an OLED in which material SdT2 in accordance with the prior art is used in the ETL, a significant improvement in voltage and power efficiency is observed on use of materials 1-19 according to the invention (Examples V2 and E2).

TABLE-US-00012 TABLE 1 Structure of the OLEDs HTL/IL(HATCN; 5 nm)/EBL/EML/HBL/ETL/EIL HTL EBL EML HBL ETL EIL Ex. Thickness Thickness Thickness Thickness Thickness Thickness V1 SpA1 SpMA1 SdT1:TER1 — ST2:LiQ — 90 nm 130 nm (92%:8%) 40 nm (50%:50%) 40 nm V2 SpA1 SpMA1 IC1:TEG1 — SdT2:ST2 LiQ 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm 3 nm E1 SpA1 SpMA1 1-18:TER1 — ST2:LiQ — 90 nm 130 nm (92%:8%) 30 nm (50%:50%) 30 nm E2 SpA1 SpMA1 IC1:TEG1 — 1-19:ST2 LiQ 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm 3 nm E3 SpA1 SpMA1 4-12:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E4 SpA1 SpMA1 4-1:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E5 SpA1 SpMA1 1-1:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E6 SpA1 SpMA1 1-5:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E7 SpA1 SpMA1 1-7:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E8 SpA1 SpMA1 1-9:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E9 SpA1 SpMA1 IC1:TEG1 — 1-11:ST2 LiF 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm 1 nm E10 SpA1 SpMA1 1-14:IC3:TEG1 IC1 ST2:LiQ — 70 nm 90 nm (45%:45%:10%) 30 nm 10 nm (50%:50%) 30 nm E11 SpA1 SpMA1 1-15:IC3:TEG1 IC1 ST2:LiQ — 70 nm 90 nm (45%:45%:10%) 30 nm 10 nm (50%:50%) 30 nm E12 SpA1 SpMA1 IC1:3-3:TEG1 IC1 ST2:LiQ — 70 nm 90 nm (45%:45%:10%) 30 nm 10 nm (50%:50%) 30 nm E13 SpA1 SpMA1 4-3:TER1 — ST2:LiQ — 90 nm 130 nm (92%:8%) 30 nm (50%:50%) 30 nm E14 SpA1 SpMA1 IC1:TEG1 — 4-5:LIQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm E15 SpA1 SpMA1 4-11:TEG1 — ST2:LiQ — 70 nm 90 nm (90%:10%) 30 nm (50%:50%) 40 nm

TABLE-US-00013 TABLE 2 Data of the OLEDs U1000 CE1000 PE1000 EQE CIE x/y at Ex. (V) (cd/A) (lm/W) 1000 1000 cd/m.sup.2 V1  5.4 12 7 10.6% 0.67/0.33 V2  3.7 69 59 18.2% 0.34/0.62 E1  4.9 14 9 13.3% 0.67/0.33 E2  3.4 67 64 18.0% 0.33/0.62 E3  3.6 61 53 16.9% 0.33/0.62 E4  3.3 63 60 17.2% 0.34/0.62 E5  3.5 64 61 17.4% 0.34/0.62 E6  3.6 66 58 17.6% 0.34/0.62 E7  3.3 64 61 17.3% 0.33/0.62 E8  3.8 55 45 15.4% 0.34/0.62 E9  3.4 58 54 16.4% 0.33/0.62 E10 3.5 60 54 16.7% 0.34/0.63 E11 3.7 61 52 16.9% 0.33/0.62 E12 3.6 56 49 16.0% 0.34/0.62 E13 5.1 15 9 13.8% 0.67/0.33 E14 3.6 66 58 18.4% 0.34/0.62 E15 3.9 60 48 16.6% 0.33/0.62

TABLE-US-00014 TABLE 3 Structural formulae of the materials for the OLEDs [00488] HATCN [00489] SpA1 [00490] SpMA1 [00491] LiQ [00492] SpMA2 [00493] TEY1 [00494] IC2 [00495] ST2 [00496] IC1 [00497] IC3 [00498] SdT1 [00499] SdT2 [00500] TEG1 [00501] TER1 [00502] 1-18 [00503] 1-19 [00504] 4-12 [00505] 4-1 [00506] 1-1 [00507] 1-5 [00508] 1-7 [00509] 1-9 [00510] 1-11 [00511] 1-14 [00512] 1-15 [00513] 3-3 [00514] 4-3 [00515] 4-5 [00516] 4-11