(12) United States Patent (10) Patent No.: US 8.487,300 B2 Parham Et Al

US0084873 OOB2

(12) United States Patent (10) Patent No.: US 8.487,300 B2 Parham et al. (45) Date of Patent: Jul. 16, 2013

(54) ORGANICELECTROLUMINESCENT 5.432,014 A 7/1995 Sano et al. DEVICES COMPRISING 5,840,217 A 1 1/1998 Lupo et al. 6,410,166 Bl 6/2002 Takahashi et al. AZOMETHINE-METAL COMPLEXES 6.458,909 B1 10/2002 Spreitzer et al. 7,701,131 B2 4/2010 Gerhard et al. (75) Inventors: Amir Hossain Parham, Frankfurt (DE); 2005/0244672 A1 11/2005 Cheet al. Jonas Kroeber, Frankfurt (DE); Anja 2006,004O139 A1 2/2006 Herronet al. Gerhard, Veitschöchheim (DE); Rocco 2006/0255332 A1 11/2006 Becker et al. Fortte, Frankfurt (DE) 2007.0034.863 A1 2/2007 Fortte et al. FOREIGN PATENT DOCUMENTS (73) Assignee: Merck Patent GmbH (DE) CN 1793.281 A 6, 2006 EP 676461 A2 10, 1995 (*) Notice: Subject to any disclaimer, the term of this EP 1191612 A2 3, 2002 patent is extended or adjusted under 35 EP 1191613 A2 3, 2002 U.S.C. 154(b) by 327 days. EP 1191614 A2 3, 2002 WO WO-98.27136 A1 6, 1998 WO WO-OO.70655 A2 11/2000 (21) Appl. No.: 12/742.549 WO WO-01/41512 A1 6, 2001 WO WO-02/02714 A2 1, 2002 (22) PCT Filed: Oct. 14, 2008 WO WO-02/15645 A1 2, 2002 WO WO-2005/OO3253 A2 1, 2005 (86). PCT No.: PCT/EP2008/OO8684 WO WO-2005/011013 A1 2, 2005 WO WO-2005/033244 A1 4/2005 S371 (c)(1), (2), (4) Date: May 12, 2010 Primary Examiner — Fernando L Toledo Assistant Examiner — Valerie N Newton (87) PCT Pub. No.: WO2009/062578 (74) Attorney, Agent, or Firm — Novak Druce Connolly PCT Pub. Date: May 22, 2009 Bove + Quigg LLP (65) Prior Publication Data (57) ABSTRACT US 2010/O244009 A1 Sep. 30, 2010 The present invention relates to phosphorescent organic elec troluminescent devices which contain as a matrix material of (30) Foreign Application Priority Data emitting layer, metal complexes of the formula (I) Nov. 12, 2007 (DE) ...... 10 2007 O53 771 formula (I) (51) Int. Cl. HOIL 29/08 (2006.01) RI R1 HOIL 35/24 (2006.01) HOIL 5L/00 (2006.01) HOIL 2L/00 (2006.01) \ na Y / C09K II/02 (2006.01) X Y. Y X (52) U.S. Cl. V \ / USPC ... 257/40; 257/E51.018; 438/46; 252/301.36 M N M (58) Field of Classification Search X \ 1 YS / Y. USPC ...... 438/46 N N See application file for complete search history. M \ (56) References Cited RI R1 U.S. PATENT DOCUMENTS 4,539,507 A 9/1985 VanSlyke et al. 5,151,629 A 9/1992 VanSlyke 17 Claims, No Drawings US 8,487,300 B2 1. 2 ORGANICELECTROLUMNESCENT invention therefore relates to phosphorescent electrolumines DEVICES COMPRISING cent devices which contain these complexes as matrix mate AZOMETHINE-METAL COMPLEXES rial in the emitting layer. The present invention thus relates to organic electrolumi CROSS-REFERENCE TO RELATED nescent devices comprising, in the emitting layer, at least one APPLICATIONS phosphorescent compound and at least one compound of the formula (I) This application is a national stage application (under 35 U.S.C. S371) of PCT/EP2008/008684, filed Oct. 14, 2008, which claims benefit of German application 10 2007 053 10 formula (I) 771.0, filed Nov. 12, 2007. RI RI BACKGROUND OF THE INVENTION

15 \ 4. The structure of organic electroluminescent devices (OLEDs) in which organic semiconductors are employed as XY / N y1 / X functional materials is described, for example, in U.S. Pat. No. 4,539,507, U.S. Pat. No. 5,151,629, EP 0676461 and WO M 98/27136. In recent years, organometallic complexes which YS / X exhibit phosphorescence instead of fluorescence are increas \ ingly being employed (M. A. Baldo et al., Appl. Phys. Lett. ) () 1999, 75, 4-6). For quantum-mechanical reasons, an up to RI four-fold increase in energy and power efficiency is possible using organometallic compounds as phosphorescent emit 25 ters. In general, there are still considerable problems in where the following applies to the symbols and indices used: OLEDs which exhibit triplet emission. For example, the M is on each occurrence, identically or differently, a metalion physical properties of phosphorescent OLEDs are still unsat in the oxidation state +II, selected from Be, Mg, Ca,Sr., Ba, isfactory with respect to efficiency, operating Voltage and Fe, Ru, Os, Co, Ni, Pd, Cu, Zn, Cd, Hg, Sn and Pb: lifetime for use of triplet emitters in high-quality and long 30 X is on each occurrence, identically or differently, O, S or lived electroluminescent devices. CO O: In accordance with the prior art, 4,4'-bis(N-carbazolyl) Ar' is an aromatic or heteroaromatic ring system having 5 to biphenyl (CBP) is frequently used as matrix material in phos 60 aromatic ring atoms, which may be substituted by one or phorescent OLEDs. The disadvantages are short lifetimes of more radicals R and in which individual aromatic groups the devices produced therewith and high operating Voltages, 35 may be linked to one another via alkylene groups having 1 which result in low power efficiencies. In addition, CBP has to 10 C atoms, in which, in addition, one or more non an inadequately high glass transition temperature. In spite of adjacent C atoms may be replaced by O or S; all disadvantages of CBP, it continues to be used as triplet Ar is on each occurrence, identically or differently, an aro matrix material since the problems described above have also matic or heteroaromatic ring system having 5 to 60 aro not yet been solved satisfactorily using alternative matrix 40 matic ring atoms, which may be substituted by one or more materials. radicals R; Aluminium complexes, in particular B-Alq, are further Y is on each occurrence, identically or differently, a single more known as triplet matrix materials (for example Chem. bond or an alkylene group having 1 to 10 C atoms, in Phys. Lett. 2005, 404, 121-125). which, in addition, one or more non-adjacent C atoms US 2006/040 139 describes the use of metal complexes 45 which are not bonded to the nitrogen may be replaced by O with ligands based on Schiffbase as host material for photo and which may be substituted by one or more radicals R; active materials. However, only complexes with trivalent R is on each occurrence, identically or differently, H. F. Cl, Br, metals, in particular aluminium complexes which are penta I, N(R), CN, NO, Si(R), B(OR), C(=O)R, P(=O) or hexacoordinated, are disclosed. (R), S(=O)R’, S(=O),R, OSOR, a straight-chain 50 alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or BRIEF SUMMARY OF THE INVENTION a branched or cyclic alkyl, alkoxy or thioalkyl group hav ing 3 to 40 C atoms, each of which may be substituted by The object of the present invention is the provision of one or more radicals R, where one or more non-adjacent triplet matrix materials which have a Sufficiently high glass CH groups may be replaced by RC=CR, C=C, Si transition temperature and very good thermal stability and are 55 (R), Ge(R), Sn(R), C=O, C-S, C-Se, C=NR, stable to hydrolysis and result in improvements in the effi P(=O)(R), SO, SO, NR. O.S or CONR and where one ciency, lifetime and operating Voltage in organic electrolumi or more H atoms may be replaced by F, Cl, Br, I, CN or nescent devices compared with the prior art. NO, or an aromatic or heteroaromatic ring system having Surprisingly, it has now been found that certain metal che 5 to 60 aromatic ring atoms, each of which may be substi late complexes with divalent metal ions in which the ligand 60 tuted by one or more radicals R, or an aryloxy or het coordinates to the metal via two imine nitrogenatoms exhibit eroaryloxy group having 5 to 60 aromatic ring atoms, significant improvements, in particular with respect to the which may be substituted by one or more radicals R, or a lifetime, efficiency, stability to temperature stress, glass tran combination of these systems; two or more substituents R sition temperature and hydrolysis stability. These complexes, here may also form a mono- or polycyclic aliphatic or which may also be in the form of dimers, contain tetracoor 65 aromatic ring system with one another, dinated metal ions in the oxidation state +II in square-planar, R" is on each occurrence, identically or differently, H, F, CFs, tetrahedral or pseudo-tetrahedral coordination. The present a straight-chain alkyl group having 1 to 40 C atoms or a US 8,487,300 B2 3 4 branched orcyclic alkyl group having 3 to 40 Catoms, each n-pentyl, S-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-hep of which may be substituted by one or more radicals R. tyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluo where one or more non-adjacent CH2 groups may be romethyl, pentafluoroethyl, 2.2.2-trifluoroethyl, ethenyl, pro replaced by RC=CR, C=C, Si(R), Ge(R), Sn(R) penyl, butenyl, pentenyl, cyclopentenyl, hexenyl, and where one or more H atoms may be replaced by F, Cl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cycloocte Br, I, CN or NO, or an aromatic or heteroaromatic ring nyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl system having 5 to 60 aromatic ring atoms, each of which or octynyl. A C- to Co-alkoxy group is preferably taken to may be substituted by one or more radicals R, or a com mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-pro bination of these systems; R' here may also form a mono poxy, n-butoxy, i-butoxy, S-butoxy, t-butoxy or 2-methylbu or polycyclic aliphatic or aromatic ring system with one or 10 toxy. An aromatic or heteroaromatic ring system having 5 to more substituents R; 40 aromatic ring atoms, which may also in each case be R’ is on each occurrence, identically or differently, H. Foran substituted by the above-mentioned radicals R and which aliphatic, aromatic or heteroaromatic hydrocarbon radical may be linked to the aromatic or heteroaromatic ring system having 1 to 20 C atoms, in which, in addition, one or more via any desired positions, is taken to mean, in particular, Hatoms may be replaced by F, two or more substituents R 15 groups derived from benzene, naphthalene, anthracene, here may also form a mono- or polycyclic aliphatic or phenanthrene, pyrene, chrysene, benzanthracene, perylene, aromatic ring system with one another, fluoranthene, benzofluoranthene, naphthacene, pentacene, n is on each occurrence, identically or differently, 0, 1 or 2. benzopyrene, dibenzanthracene, biphenyl, biphenylene, ter phenyl, terphenylene, fluorene, spirobifluorene, dihydro DETAILED DESCRIPTION OF THE INVENTION phenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-monobenzoindenofluo The compounds of the formula (I) preferably have a glass rene, cis- or trans-dibenzoindenofluorene, truxene, isotruX transition temperature T of above 100° C., particularly pref ene, spirotruXene, spiroisotruXene, furan, benzofuran, erably above 120° C. isobenzofuran, dibenzofuran, thiophene, benzothiophene, For the purposes of the present invention, a phosphorescent 25 isobenzothiophene, dibenzothiophene, pyrrole, indole, isoin compound is taken to mean a compound which luminesces dole, carbazole, pyridine, quinoline, isoquinoline, acridine, from an excited State with higher spin multiplicity, i.e. a spin phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, state >1, in particular from an excited triplet state. The emis benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, sion here can take place either from a pure triplet state or from indazole, imidazole, benzimidazole, naphthimidazole, a mixed state with participation of a triplet state. For the 30 phenanthrimidazole, pyridimidazole, pyrazinimidazole, qui purposes of this invention, any luminescence from an iridium noxalinimidazole, oxazole, benzoxazole, naphthoxazole, or platinum complex is taken to mean phosphorescence. anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3- For the purposes of the present invention, an aryl group thiazole, benzothiazole, pyridazine, benzopyridazine, pyri contains 6 to 40 C atoms; for the purposes of the present midine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, invention, a heteroaryl group contains 2 to 40 C atoms and at 35 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-di least one heteroatom, with the proviso that the sum of Catoms azapyrene, 4,5-diazapyrene, 4.5.9,10-tetraazaperylene, pyra and heteroatoms is at least 5. The heteroatoms are preferably Zine, phenazine, phenoxazine, phenothiazine, fluorubin, selected from N, O and S. An aryl group or heteroaryl group naphthyridine, azacarbazole, benzocarboline, phenanthro here is taken to mean either a simple aromatic ring, i.e. ben line, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1.2.3-Oxa Zene, or a simple heteroaromatic ring, for example pyridine, 40 diazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1.3,4-oxadiaz pyrimidine, thiophene, or a condensed aryl or heteroaryl ole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1.2.5-thiadiazole, group, for example naphthalene, anthracene, phenanthrene, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triaz quinoline, isoquinoline. ine, tetrazole, 1,2,4,5-tetrazine, 1.2.3,4-tetrazine, 1.2.3,5-tet For the purposes of the present invention, an aromatic ring razine, purine, pteridine, indolizine and benzothiadiazole. system contains 6 to 40 C atoms in the ring system. For the 45 In a preferred embodiment of the invention, the metal M is purposes of the present invention, a heteroaromatic ring sys selected from Be, Mg, Pd, Zn or Cd. The metal M is particu tem contains 2 to 40 C atoms and at least one heteroatom in larly preferably Zn. the ring system, with the proviso that the sum of C atoms and The index n is furthermore preferably=0 or 1. The index in heteroatoms is at least 5. The heteroatoms are preferably is particularly preferably 0. selected from N, O and S. For the purposes of this invention, 50 The symbol Y, identically or differently on each occur an aromatic or heteroaromatic ring system is to be taken to rence, furthermore preferably stands for a single bond or for mean a system which does not necessarily contain only aryl or a C(R) group, particularly preferably for a single bond. heteroaryl groups, but instead in which a plurality of aryl or The symbol X, identically or differently on each occur heteroaryl groups may also be interrupted by a non-aromatic rence, furthermore preferably stands for O or S. particularly unit (preferably less than 10% of the atoms other than H), 55 preferably for O. such as, for example, an sp-hybridised C, Nor O atom. Thus, Particular preference is given to compounds of the formula for example, systems such as 9.9'-spirobifluorene, 9,9-dia (I) in which the preferences mentioned above are present rylfluorene, triarylamine, diaryl ether, stilbene, are also to be simultaneously, i.e. compounds in which the metal M is regarded as aromatic ring systems for the purposes of the selected from Be, Mg, Pd, Zn or Cd and in which the index present invention, and likewise systems in which two or more 60 n=0 or 1 and in which the symbol Y, identically or differently aryl groups are interrupted, for example, by a linear or cyclic on each occurrence, stands for a single bond or for a C(R) alkyl group or by a silyl group. group and in which the symbol X, identically or differently on For the purposes of the present invention, a C- to Cao-alkyl each occurrence, stands for O or S. Very particular preference group, in which, in addition, individual H atoms or CH is given to compounds of the formula (I) in which the metal M groups may be substituted by the above-mentioned groups, is 65 is Zn and in which the index n=0 and in which the symbol Y preferably taken to mean the radicals methyl, ethyl, n-propyl. stands for a single bond and in which the symbol X stands for i-propyl. n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, O. US 8,487,300 B2 5 6 The symbol Ar' furthermore preferably stands, for n=0, for -continued an aromatic or heteroaromatic ring system having 5 to 24 (XI) aromatic ring atoms, each of which may be substituted by one R R or more radicals R. The group Y—Ar' Y particularly pref R erably stands, for n=0, for a group of the following formulae R F w (II) to (XV): (XII)

(II) R R 10 R R

A w F f w (XIII) w R. R. (III) 15

w w F w (XIV) A. w w R (IV) R

25 R. R.

(V) (XV) 30

(VI) ( )N 35 (VII) The symbol Ar' furthermore preferably stands, for n=1, for 40 an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, in particular having 6 to 12 aromatic ring atoms, each of which may be substituted by one or more (VIII) radicals R. The symbol Ar' particularly preferably stands, for R. R. n=1, for a group of the following formulae (XVI) to (XXI): 45

O (XVI) 50 (IX)

N 55 a- (XVII)

(X)

(XVIII) O 60

W 65 W CO W W US 8,487,300 B2 8 -continued chain alkyl group having 1 to 4 C atoms or a branched alkyl (XIX) group having 3 or 4C atoms, each of which may be substi R. R. tuted by one or more radicals R, where one or more Hatoms may be replaced by F, oran aryl group having 6 to 10 aromatic ring atoms, which may in each case be substituted by one or iii. more radicals R; two or more substituents Rhere may also form a mono- or polycyclic aliphatic or aromatic ring system with one another.

(XX) 10 The symbol R", identically or differently on each occur O rence, furthermore preferably stands for H, a straight-chain alkyl group having 1 to 6 Catoms or a branched orcyclic alkyl group having 3 to 6 C atoms, where in each case one or more Hatoms may also be replaced by F, or for an aryl or heteroaryl 15 group having 5 to 16 aromatic ring atoms, each of which may w A (XXI) be substituted by one or more radicals R. The symbol R', identically or differently on each occurrence, particularly preferably stands for H, a methyl group or a phenyl or naph thyl group, each of which may be substituted by one or more radicals R. The compounds of the formula (I) may optionally be in dimeric or oligomeric form in the Solid state and are not necessarily in the form of simple complexes, as depicted in The dashed bonds in the formulae (II) to (XXI) in each case 25 simplified form in formula (I). Organic electroluminescent represent the link to the imine nitrogen. The index m in devices which contain compounds of the formula (I) which formula (XIX) is 1 to 10. are in dimeric or oligomeric form are therefore naturally Particular preference is given to compounds of the formula covered by the invention in the same way as electrolumines (I) which simultaneously have the above-mentioned prefer cent devices which contain the compounds of the formula (I) ences for M, n, Y and X and a group Ar' selected from the 30 as simple complexes. formulae (II) to (XXI) depicted above. The symbol Ari, identically or differently on each occur Preference is furthermore given to symmetrical com rence, furthermore preferably stands for an aryl or heteroaryl pounds, i.e. compounds in which all symbols Ari are identi group having 5 to 16 aromatic ring atoms, which may be cal, all symbols X are identical, all symbols R' are identical, substituted by one or more radicals R. The symbol Art, iden 35 all symbols Y are identical and which are identically substi tically or differently on each occurrence, particularly prefer tuted. ably stands for an aryl or heteroaryl group selected from Examples of preferred compounds containing structural phenyl, 1- or 2-naphthyl, 4-biphenyl, 1- or 2-anthryl, 2- or elements of the formula (I) are compounds (1) to (180) 3-thienyl, 2- or 3-pyrrolyl, 2- or 3-furanyl, 2-, 3- or 4-pyridi depicted below: nyl, 3- or 4-pyridazinyl, 4- or 5-pyrimidinyl, pyrazinyl, 2-, 3-, 40 4-, 5-, 6-, 7- or 8-quinolinyl or 3-, 4-, 5-, 6-, 7- or 8-isoquino linyl, each of which may be substituted by one or more radicals R. Very particular preference is given to phenyl, 1-naphthyl 2-naphthyl and 4-biphenyl, in particular phenyl, (1) each of which may be substituted by one or more radicals R. 45 Particular preference is given to compounds of the formula (I) which simultaneously have the above-mentioned pre ferred groups Ar and a group Ar' selected from the formulae (II) to (XXI) depicted above. Very particular preference is H N N H given to compounds of the formula (I) which simultaneously 50 2N-1sl have the above-mentioned particular preferences for M, n, Y. o/ Yo X and Art and a group Ar' selected from the formulae (II) to (XV) depicted above. The symbol R, identically or differently on each occur rence, furthermore preferably stands for H, F, N(R), Si 55 (R), C(=O)R, P(=O)(R), a straight-chain alkyl group (2) having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, each of which may be substituted by one or more radicals R, where one or more non-adjacent CH groups may be replaced by RC=CR, O or S and one or 60 more H atoms may be replaced by F, or an aryl or heteroaryl group having 5 to 16 aromatic ring atoms, each of which may be substituted by one or more radicals R, or a combination of these systems; two or more Substituents Rhere may also form a mono- or polycyclic aliphatic or aromatic ring system with 65 one another. The symbol R, identically or differently on each occurrence, particularly preferably stands for H. F., a straight US 8,487,300 B2 9 10 -continued -continued (3) (8)

(4) 15 OS

(9)

25 (5)

(10) 35

(6)

50 (11) (7)

65 US 8,487,300 B2 11 12 -continued -continued (12)

(13)

(18) 30

(14) 40

(19)

HC N N CH 45

3 21 N-1l n 3

(15) 55 (20)

US 8,487,300 B2 15 16 -continued -continued (29) (33) H.C. CH3

HC N N CH H. N. N H 3 21 N 1. N 3 a N 1. n Zn 2Zn, Y No 10 O O

15 F F

(30) (34) H3C CH3 2O O O 21 N-1 N 25 HC 2N. 1N 1 No o/ "N,

30 N NN 21 2

(31) 35 c C (35)

H 2N-1'sN N H 40 / O 27"Q O O

50 (32)

(36) 55 O O O O /NZn

O O 65 HC O O O O CH

US 8,487,300 B2 20 -continued (50)

1'sN Yo

CH3

(51)

N H n No

(52)

N CH u-1 n 3 l No

(53)

H No O US 8,487,300 B2 21 22 -continued -continued (54) (58)

(59)

30 (60)

(56) 35

N CH 3 C 4N Zn n

40 N N CH3 2'N, as CH3 C -7 a. (61) COO O CH CH H N R N H (57) 2 Z n 50 C O CO 55 (62)

H N N H 1 "Nol 60 N N a n

65 C CO US 8,487,300 B2 23 24 -continued -continued (63) (67)

F H 4N-1s H F 1. No 10

(64) (68)

N N H CH."N2'Y-1's CH 1 Zn 25 2N-1's OOO O O COO 1 No CH3 CH3 30 \- SS

(65) 35 (69)

H 4 N.-1s H 40 1 No

O O

(70) (66)

N N 21 N-1 n 1 No

\-d OS US 8,487,300 B2 25 26 -continued -continued (71) (76)

10 O 4S.-1's O 1 No

15 (72)

(77)

(73) 30

35 (78)

40 N-1 N CH3 (74) 1"N

50 (79)

(75) 55

60 N.u-1 N-" 1 No

65 US 8,487,300 B2 27 28 -continued -continued (80) (84) O-4D-O 1.

(81)

25 H 4N -1N1" O 4N -1 N O 1"N, 1"N, 30 O O (86)

(82) ( ) HC 4N -1's CH 40 o-7"S

(87)

21 (83) 1 No ( ) 55 ( ) (88)

2N-'s1. "No 60 O 2N. -1's O O CO CO O. O. 1 "No O US 8,487,300 B2 29 30 -continued -continued (89) (93)

(94)

(91)

(95) 40

(96)

60 US 8,487,300 B2 31 32 -continued -continued (97) (101) O O O N H 10 1. N l N O

(98) 2O (102)

25 H N COC 21 N-1 N 1. N

40 (103)

50 (100)

55 (104)

65 US 8,487,300 B2 33 34 -continued -continued (109) (105) CH3 HC CH 5

N 10 4N 1. n H 4N N Z l 1 O 1 Yo

(110) ce H (106) CH3

35 (111)

(107) CH 40

50 (112)

(108)

65 US 8,487,300 B2 35 36 -continued -continued (113) (117)

(114) (118)

35 (119)

(115) 40

(120) (116) 5 V /

60 N 1. N N US 8,487,300 B2 37 38 -continued -continued O. O (121) (126)

VWS 2N-1's H 2N. 1N H 10 N 1 Yo N N 21 CS o

21 N 15 (127)

(122) O O VW S CS21N-1 N o HC 4N 1N CH 25 Zn 1N (128)

(123) Zn

40 (129) (124)

45 H3C 2N, 1 NN CH

50 O 1"N, O

(125) 55 (130)

60 H3C 2N-1 n - 'S

65 O O O CO US 8,487,300 B2 39 40 -continued -continued (131) (136)

2 n S. >z. Yo1N 10 >. Ys1. (132) is (137)

2N.N -1N 2O 27"\ 21 N N 1. NN O O 27"\ S S

( )—K) 30 (138) N N 2 N-1 n Or 1 N. O 35 4N-n O O 40 1 N. ( ) ( ) (139) 45

S S 50 1 N

(135) ( ) ( ) 55 ( ) K) (140)

2N, 1N 60 N 1. O S S CO 65 US 8,487,300 B2 41 42 -continued -continued (141)

(146)

25 (147)

(143) 30

40 (144)

45 (148)

(145)

N 65 1 'N US 8,487,300 B2 43 44 -continued -continued

(149) (152)

(153)

(154)

65 US 8,487,300 B2 45 46 -continued -continued (158)

(155)

(159)

(160)

(157)

65 US 8,487,300 B2 47 48 -continued -continued (161) (165)

(163)

40 (167)

(164) (168)

65 US 8,487,300 B2 49 50 -continued -continued (169) (174)

2NN- Nn 10 / N

(170) 15 \-d OS (175)

N a NP -N n / N 25

(176)

40 (177)

55 2N-1s / N 60

O 65 US 8,487,300 B2 51 52 -continued compound. The emission layers particularly preferably have (179) in total a plurality of emission maxima between 380 nm and 750 nm, resulting overall in white emission, i.e. various emit ting compounds which are able to fluoresce or phosphoresce 5 are used in the emitting layers. Particular preference is given to three-layer systems in which the three layers exhibit blue, green and orange or red emission (for the basic structure see, ''NeNN-N-1's for example, WO 05/011013). / N The phosphorescent compounds (triplet emitters) com 10 prise at least one compound which emits light, preferably in the visible region, on Suitable excitation and in addition con tains at least one atom having an atomic number greater than (180) 20, preferably greater than 38 and less than 84, particularly 15 preferably greater than 56 and less than 80. The phosphores cent emitters used are preferably compounds which contain copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold 21NN- N or europium, in particular compounds which contain iridium or platinum. Particularly preferred organic electroluminescent devices contain, as phosphorescent emitters, at least one compound of CSC the formulae (XXII) to (XXV) 25 The compounds of the formula (I) can be synthesised by (XXII) DCy standard methods of organic chemistry. In particular, two A-Ir3 synthesis possibilities are suitable here. Thus, it is possible CCy firstly to synthesise the ligand from the corresponding 2 30 (XXIII) diamine and an aldehyde or ketone with formation of a Schiff DCy base, which is then reacted, in a further step, with a suitable Irg metal salt to give the corresponding metal complex. It is CCy furthermore also possible to carry out the ligand synthesis and 3 (XXIV) the complexing reaction in one step (template synthesis) by 35 -PCy reacting a diamine, an aldehyde or ketone and a Suitable metal A-PtC salt with one another simultaneously (Eur: J. Inorg. Chem. CCy 2004, 4561-65). (XXV) DCy The compounds of the formula (I) serve as matrix materials Pt for the phosphorescent emitters used in the emitting layer in 40 CCy the organic electroluminescent devices. 2 The invention therefore furthermore relates to the use of compounds of the formula (I) as matrix material for phospho where R has the same meaning as described above for for rescent compounds in organic electroluminescent devices. mula (I), and the following applies to the other symbols used: The organic electroluminescent device comprises cathode, 45 DCy is, identically or differently on each occurrence, a cyclic anode and at least one emitting layer. In addition to these layers, it may also comprise further layers, for example in group which contains at least one donor atom, preferably each case one or more hole-injection layers, hole-transport nitrogen, carbon in the form of a carbene or phosphorus, layers, electron-blocking layers, hole-blocking layers, elec via which the cyclic group is bonded to the metal, and tron-transport layers, electron-injection layers, charge-gen- 50 which may in turn carry one or more Substituents R; the eration layers (IDMC 2003, Taiwan; Session 21 OLED (5), T. groups DCy and CCy are connected to one another via a Matsumoto, T. Nakada, J. Endo, K. Mori, N. Kawamura, A. covalent bond; Yokoi, J. Kido, Multiphoton Organic EL Device Having CCy is, identically or differently on each occurrence, a cyclic Charge Generation Layer) and/or organic or inorganic pin group which contains a carbon atom via which the cyclic junctions. It is likewise possible for interlayers which have, 55 group is bonded to the metal and which may in turn carry for example, an exciton-blocking function to be introduced one or more substituents R; between two emitting layers. However, it should be pointed A is, identically or differently on each occurrence, a monoan out that each of these layers does not necessarily have to be ionic, bidentate chelating ligand, preferably a diketonate present. ligand. In a preferred embodiment of the invention, the emitting 60 The formation of ring systems between a plurality of radi layer which comprises the compound of the formula (I) and cals R may also produce a bridge between the groups DCy the phosphorescent emitter is a red-, green- or blue-emitting and CCy. layer. Examples of the emitters described above are revealed by In a further preferred embodiment of the invention, the the applications WO 00/70655, WO 01/41512, WO organic electroluminescent device comprises a plurality of 65 02/02714, WO 02/15645, EP 1191613, EP 1191612, EP emitting layers, where at least one layer comprises at least one 1191614 and WO 05/033244. In general, suitable phospho compound of the formula (I) and at least one phosphorescent rescent complexes are all those as are used in accordance with US 8,487,300 B2 53 54 the prior art for phosphorescent OLEDs and as are known to The starting materials can be purchased from ALDRICH or the person skilled in the art in the area of organic electrolu are prepared by processes known from the literature. The minescence. synthesis of 2,2'-diaminobiphenyl from 2,2'-dinitrobiphenyl The mixture of the at least one compound of the formula (I) is carried out in accordance with the process described in and the at least one phosphorescent emitter comprises Chem. Commun. 2005, 46,5799-5801. The synthesis of 4,4'- between 1 and 99% by weight, preferably between 2 and 90% dibromo-2,2'-dinitrobiphenyl is described in J. Am. Chem. by weight, particularly preferably between 3 and 40% by Soc. 2006, 128,9034-9035. The synthesis of 2-mercaptoben weight, in particular between 5 and 15% by weight, of the at Zaldehyde is described in Synlett 2001, 1956-1958. least one phosphorescent emitter, based on the entire mixture of emitter and matrix material. Correspondingly, the mixture 10 Example 1 comprises between 99 and 1% by weight, preferably between 98 and 10% by weight, particularly preferably between 97 Synthesis of 3'2"-diamino-p-quaterphenyl and 60% by weight, in particular between 95 and 85% by weight, of the at least one matrix material of the formula (I), a) Preparation of 3'2"-dinitro-p-quaterphenyl based on the entire mixture of emitter and matrix material. 15 Besides the matrix material of the formula (I), the entire mixture may also comprise further matrix materials. Preference is furthermore given to an organic electrolumi NO nescent device which is characterised in that one or more layers are applied by means of a Sublimation process, in which the materials are vapour-deposited in vacuum Subli mation units at a pressure below 10 mbar, preferably below 10 mbar. Preference is likewise given to an organic electrolumines ON2 cent device which is characterised in that one or more layers 25 are applied by means of the OVPD (organic vapour phase 2.4 g (2.1 mmol) of Pd(PPh) are added to a well-stirred, deposition) process or with the aid of carrier-gas Sublimation, degassed suspension of 18.8 g (154.5 mmol) of phenylbo in which the materials are applied at a pressure between 10 ronic acid, 30 g (74.6 mmol) of 2,5-dibromonitrobenzene and mbar and 1 bar. A special case of this process is the OVJP 53 g (212.7 mmol) of potassium carbonate in a mixture of 300 (organic vapour jet printing) process, in which the materials ml of water and 300 ml of THF, and the mixture is heated are applied directly through a nozzle and are thus structured 30 (for example M. S. Arnold et al., Appl. Phys. Lett. 2008, 92, under reflux for 20 hours. After cooling, the organic phase is 053301). separated off, washed three times with 200 ml of water and Preference is furthermore given to an organic electrolumi once with 200 ml of saturated sodium chloride solution, dried nescent device which is characterised in that one or more over magnesium sulfate and evaporated to dryness in vacuo in layers are produced from Solution, such as, for example, by a rotary evaporator. The grey residue is recrystallised from spin coating, or by means of any desired printing process, 35 hexane. The deposited crystals are filtered off with suction, Such as, for example, Screen printing, flexographic printing or washed with a little MeOH and dried in vacuo; yield: 23 g, offset printing, but particularly preferably LITI (light induced 80% of theory; purity: 99.2% according to HPLC. thermal imaging, thermal transfer printing) or ink-jet print ing. Soluble compounds are necessary for this purpose. b) Preparation of 3'2"-diamino-p-quaterphenyl These processes are known in general to the person skilled 40 in the art and can be applied by him without problems to the system according to the invention comprising compounds of the formula (I) and triplet emitters. NH2 The compounds of the formula (I) have the following sur prising advantages over the prior art on use in organic elec 45 troluminescent devices: 1. The operating Voltage is considerably reduced on use of compounds of the formula (I) compared with B-Alq and HN other aluminium complexes, which results in significantly higher power efficiency. 50 2. The lifetime of the devices is also improved on use of the 16.6 g (42 mmol) of 3'2"-dinitro-p-quaterphenyl and 1.99 compounds of the formula (I) as triplet matrix materials. g of Pd/C (10%) are suspended in 200 ml of methanol, and 8.4 3. Furthermore, the efficiency of the devices is improved on g (222 mmol) of Sodium borohydride are added in portions use of the compounds of the formula (I) as triplet matrix with stirring at 0°C. After stirring for 2 hours, the clear materials. solution is neutralised with dilute HC1. The solvent is then 4. The compounds of the formula (I) have a significantly 55 removed, and the residue is washed intensively with water higher glass transition temperature than CBP, which is and recrystallised from dioxane. The precipitate is filtered frequently used in accordance with the prior art as triplet and dried in vacuo, giving 11 g (35.6 mmol) of a crystalline matrix material. solid. The overall yield is 78%. These above-mentioned advantages are not accompanied by impairment of the other electronic properties. 60 Example 2 The invention is explained in greater detail by the follow ing examples without wishing it to be restricted thereby. General Synthetic Procedure for Metal Complexes EXAMPLES There are two general methods for the preparation of the 65 complexes: The following syntheses are carried out under a protective A) Reaction of aromatic amines with metal salts and o-hy gas atmosphere in dried solvents, unless indicated otherwise. droxyaldehyde or o-hydroxyketone: US 8,487,300 B2 55 56 B) Reaction of Schiffbases of the aromatic amines with metal necked flask, stirrer, internal thermometer and dropping fun salts. nel. A solution of 60 mmol of the aromatic amine in 50 ml of Method A can be used if the by-product (HO) does not dry toluene and a solution of 120 mmol of the aldehyde or destroy the complex to be prepared. If this complex is mois ketone in 50 ml of toluene are subsequently slowly added ture-sensitive or if the imine formation is not quantitative, dropwise. A catalytic amount of p-toluenesulfonic acid is method B is suitable. added to the mixture. The distillation is carried out until the clear, condensed toluene appears. The residues of the solvent are removed in an oil-pump vacuum (130 Pa). The azome Method A: General synthetic procedure thines are isolated as yellow solids, recrystallised from tolu 10 ene and washed with MeOH. O R ii) Complex Synthesis A Solution of the corresponding imine ligand (17 mmol) in 100 ml of methanol is added to a solution of 19 mmol of a ML -- H - "a NH -- S. --NE, 15 Suitable metal salt, for example 3.4 g of Zinc acetate dihy 2 2 2 2x MeOH drate, in 100 ml of methanol, and the mixture is stirred at R room temperature for 3 days. After filtration, the solid is dried in vacuo and Subsequently recrystallised under a protective gaS.

Example 3

25 Synthesis of Zn Complex (1)

260 mmol of the o-hydroxyaldehyde or o-hydroxyketone are added to a solution of 121 mmol of aromatic diamine in 1000 ml of dry methanol and 100 ml of triethylamine. 127 30 mmol of metal salt, for example Zinc acetate, are Subse quently added to the mixture, which is stirred at room tem OH Zn(OAc) perature for 24 hours, then filtered and washed with cold He methanol. The product is purified by recrystallisation. NEt3/MeOH 35

Method B: General synthetic procedure O R 40

H -'a NH + N -- 2 2 MeOH 2x 45 o-Zn-No R

50 The synthesis of 2,2'-1,1'-biphenyl-2,2'-diylbis(ni trilomethylidyne)bisphenolato (2-) N.N.O.O'Zinc was described for the first time by method (B) in Journal of the Chemical Society, Dalton Transactions. Inorganic Chemistry

55 1996,2835-2838. The complex obtained by this method con tains the free ligand as by-product, which makes preparation of the complex in a purity >99% more difficult. Method (A) described above, starting from 8.9 g (48 mmol) of 2,2'-diami nobiphenyl, 17 g (140 mmol) of 2-hydroxybenzaldehyde, 8.8 60 g (48 mmol) of zinc acetate dihydrate and 40 ml of triethy lamine in 400 ml of absolute MeCH, gives the complex in a very high yield and in a purity of 99.9%. After 24 hours, the precipitated solid is washed with cold methanol, dried in i) Ligand Synthesis vacuo and subsequently recrystallised from absolute EtOH The ligand synthesis is carried out using azeotropic distil 65 under a protective gas, giving 21.5 g (47 mmol) of a crystal lation for removing the water formed. 300 ml of dry toluene line solid. The overallyield is 98% (T=152.0°C., T-280.0° are heated to the boil in a distillation apparatus with three C.). US 8,487,300 B2 57 58 Example 4 -continued

Synthesis of Zn Complex (22)

4N 10 o-Zn No

15 This complex is synthesised by method (A) starting from -- NEt/MeOH 16 g (48 mmol) of 3'2"-diamino-p-quaterphenyl, 24.3 g (140 mmol) of 2-hydroxybenzaldehyde, 8.8 g (48 mmol) of zinc acetate dihydrate and 40 ml of triethylamine in 400 ml of absolute MeOH. After 24 hours, the precipitated solid is washed with cold methanol, dried in vacuo and Subsequently recrystallised from absolute EtOH under a protective gas, giving 27 g (44 mmol) of a crystalline solid. The overall yield 25 is 96% (T-252.7°C. T., 367.6° C). Example 6

30 Synthesis of Zn Complex (2)

This complex is synthesised by method (A) starting from 35 8.9 g (48 mmol) of 2,2'-diaminobiphenyl, 24.3 g (140 mmol) of 3,4-di-tert-butyl-2-hydroxybenzaldehyde, 8.8g (48 mmol) of zinc acetate dihydrate and 40 ml of triethylamine in 400 ml of absolute MeCH. After 24 hours, the precipitated solid is 40 washed with cold methanol, dried in vacuo and Subsequently recrystallised from absolute EtOH under a protective gas, giving 29 g (42 mmol) of a crystalline solid. The overall yield is 96% (T=170.5° C., T-314.2° C). 45 Example 5

Synthesis of Zn Complex (16) 50 This complex is synthesised by method (B). a) Ligand Synthesis The synthesis is carried out from 11.16 g (60.59 mmol) of 2,2'-diaminobiphenyl, 16.3 g (120 mmol) of 2-hydroxyac 55 etophenone and 0.2 g (1.1 mmol) of p-toluenesulfonic acid in 400 ml of toluene. After 24 hours, the precipitated solid is -- washed with cold methanol, giving 20 g (47 mmol) of a crystalline solid. The overall yield is 76%. b) Complex Synthesis 60 NH2 NH2 The synthesis is carried out from 3.4 g (19 mmol) of zinc 2O acetate dihydrate and 6 g (17 mmol) of ligand in 200 ml of OH methanol. After 24 hours, the precipitated solid is washed Zn(OAc) with cold methanol, dried in vacuo and Subsequently recrys NEt/MeOH 65 tallised from absolute EtOH under a protective gas, giving 6 g (13.1 mmol) of a crystalline solid. The overall yield is 86% (T=143.4° C., T-261.0° C.). US 8,487,300 B2 59 60 Example 7 from absolute EtOH under a protective gas, giving 22 g (45 mmol) of a crystalline solid. The overall yield is 94% Synthesis of Zn Complex (15) (T=165.5°C., T-290.0° C.). Examples 9 to 11 Production and Characterisation of Organic Electroluminescent Devices Containing Compounds of the Formula (I) 10 2NN-z-N Electroluminescent devices according to the invention can o-1"No be produced as described, for example, in WO 05/003253. The results for various OLEDs are compared here. The basic structure, the materials used, the degree of doping and the 15 layer thicknesses thereof are identical for better comparabil ity. Only the host in the emission layer is varied. The first device example describes a comparative standard in accor dance with the prior art, in which the emission layer consists This complex is synthesised by method (B). of the host material B-Alq and the guest material (dopant) a) Ligand Synthesis Ir(pid). Furthermore, an OLED having an emitter layer con The synthesis is carried out from 11.16 g (60.59 mmol) of sisting of the host material Zn complex (1) and the guest 2,2'-diaminobiphenyl, 23 g (120 mmol) of 2-hydroxyben material (dopant) Ir(pic) is described. OLEDs having the Zophenone and 0.2 g (1.1 mmol) of p-toluenesulfonic acid in following structure are produced analogously to the general 400 ml of toluene. After 24 hours, the precipitated solid is process mentioned above: washed with cold methanol, giving 22.5 g (41 mmol) of a 25 Hole-injection layer (HIL) 10 nm of 2,2,7,7-tetrakis(di-para crystalline solid. The overall yield is 70%. tolylamino)spiro-9.9'-bifluorene b) Complex Synthesis Hole-transport layer (HTL) 30 nm of NPB (N-naphthyl-N- The synthesis is carried out from 3.4 g (19 mmol) of zinc phenyl-4,4'-diaminobiphenyl) acetate dihydrate and 9.2 g (17 mmol) of ligand in 200 ml of Emission layer (EML) host: B-Alq (vapour-deposited; from methanol. After 24 hours, the precipitated solid is washed 30 E-Ray and purified further, sublimed twice; bis(2-methyl with cold methanol, dried in vacuo and subsequently recrys 8-quinolinolato-N1.O8)-(1,1'-biphenyl-4-olato)alu tallised from absolute EtOH under a protective gas, giving 7.5 minium or CBP (bis(carbazol-9-yl)biphenyl) as compari g (11 mmol) of a crystalline solid. The overall yield is 73% Son or Zn complex (1). Dopant: Ir(pid) (10% doping, vapour-deposited; synthe (T-232.8° C., T-354.5° C.). 35 sised in accordance with WO 03/0068526). Example 8 Electron conductor (ETL) 20 nm of AIO (purchased from E-Ray, tris(quinolinato)aluminium(III)) Synthesis of Zn Complex (134) Cathode 1 nm of LiF 150 nm of Al on top. 40 The structure of Ir(piq) is shown below for clarity:

2O N SH 45 2N -- He NEt3/MeOH Ir

NH2 NH2 50

These as yet unoptimised OLEDs are characterised by standard methods; for this purpose, the electroluminescence 55 spectra, the efficiency (measured in cd/A) as a function of the luminance, calculated from the current/voltage/luminance characteristic lines (IUL characteristic lines), and the lifetime are determined. With OLEDs produced with the host CBP as comparative 60 experiment, a maximum efficiency of about 6.5 cd/A with colour coordinates of CIE: x=0.68, y=0.32 is typically This complex is synthesised by method (A) starting from obtained under the conditions described above. For the refer 8.9 g (48 mmol) of 2,2'-diaminobiphenyl, 19.3 g (140 mmol) ence luminous density of 1000 cd/m, voltages of 6.8 V are of 2-mercaptobenzaldehyde, 8.8 g (48 mmol) of zinc acetate required. The lifetime is about 6000 hours at an initial lumi dihydrate and 40 ml of triethylamine in 400 ml of absolute 65 nous density of 1000 cd/m (see Table 1). MeOH. After 24 hours, the precipitated solid is washed with With OLEDs produced with the host B-Alq as further cold methanol, dried in vacuo and Subsequently recrystallised comparative experiment, a maximum efficiency of about 8.0 US 8,487,300 B2 61 62 cd/A with colour coordinates of CIE: x=0.68, y=0.32 is typi Y is on each occurrence, identically or differently, a single cally obtained under the conditions described above. For the bond or an alkylene group having 1 to 10 C atoms, in reference luminous density of 1000 cd/m, voltages of 7.5V which, in addition, one or more non-adjacent C atoms are required. The lifetime is about 7000 hours at an initial which are not bonded to the nitrogen is optionally luminous density of 1000 cd/m (see Table 1). replaced by O and which is optionally substituted by one By contrast, OLEDs according to the invention produced or more radicals R; with the host Zn complex (1) exhibit maximum efficiencies of R is on each occurrence, identically or differently, H. F. Cl, 8.5 cd/A with colour coordinates of CIE: x=0.68, y=0.32 with Br, I, N(R), CN, NO, Si(R), B(OR), C(=O)R’, an otherwise identical structure, where the requisite Voltage P(=O)(R), S(=O)R, S(=O),R, OSOR, a for the reference luminous density of 1000 cd/m is 5.0 V (see 10 straight-chain alkyl, alkoxy or thioalkyl group having 1 Table 1). The lifetime at an initial luminous density of 1000 to 40 C atoms or a branched or cyclic alkyl, alkoxy or cd/m is, at 9000 hours, significantly longer and the voltage, thioalkyl group having 3 to 40 C atoms, each of which is at 5.0 V, is significantly lower than in the case of the reference optionally substituted by one or more radicals R, where materials CBP and B-Alq (see Table 1). one or more non-adjacent CH groups is optionally TABLE 1. Device results with various host materials and with Ir(pic)3 as dopant Max. Lifetime h efficiency Voltage IV initial luminance Experiment EML cod. A at 1000 ccd/m’ CIE (x,y) 1000 ccd/m Example 9 CBP: 10% of 6.5 6.8 0.680.32 6000 (comparison) Ir(piq). (40 nm) Example 10 BAlq: 10% of 8.0 7.5 0.680.32 7000 (comparison) Ir(piq). (40 nm) Example 11 Zn complex 8.5 S.O 0.680.32 9000 (1): 10% of Ir(piq). (40 nm)

The invention claimed is: 30 replaced by RC—CR, C=C, Si(R), Ge(R). 1. An organic electroluminescent device comprising, in the Sn(R), C=O, C-S, C-Se, C=NR, P(=O)(R), emitting layer, at least one phosphorescent compound and at SO, SONR, O, Sor CONR and where one or more H least one compound of formula (I) atoms is optionally replaced by F, Cl, Br, I, CN or NO, oran aromatic or heteroaromatic ring system having 5 to 35 60 aromatic ring atoms, each of which is optionally formula (I) substituted by one or more radicals R, or an aryloxy or RI heteroaryloxy group having 5 to 60 aromatic ring atoms, which is optionally substituted by one or more radicals \ 40 R’, or a combination of these systems; two or more NS / Substituents Rhere optionally forms a mono- or polycy clic aliphatic or aromatic ring system with one another; R" is on each occurrence, identically or differently, H. F. v/N Air CF, a straight-chain alkyl group having 1 to 40 Catoms 45 or a branched or cyclic alkyl group having 3 to 40 C y sk X atoms, each of which is optionally substituted by one or ) () more radicals R, where one or more non-adjacent CH RI groups is optionally replaced by RC=CR, C=C, Si(R), Ge(R), Sn(R), and where one or more H 50 atoms is optionally replaced by F, Cl, Br, I, CN or NO, wherein oran aromatic or heteroaromatic ring system having 5 to M is on each occurrence, identically or differently, a metal 60 aromatic ring atoms, each of which is optionally ion in the oxidation state +II, selected from Be, Mg, Ca, substituted by one or more radicals R, or a combination Sr., Ba, Fe, Ru, Os, Co, Cu, Zn, Cd, Hg, Sn and Pb: of these systems; R' here optionally forms a mono- or X is on each occurrence, identically or differently, O.S or 55 polycyclic aliphatic or aromatic ring system with one or CO O: more substituents R; Ar' is an aromatic or heteroaromatic ring system having 5 R’ is on each occurrence, identically or differently, H. For to 60 aromatic ring atoms, which may be substituted by an aliphatic, aromatic or heteroaromatic hydrocarbon one or more radicals Rand in which individual aromatic radical having 1 to 20 Catoms, in which, in addition, one groups may be linked to one another via alkylene groups 60 or more Hatoms is optionally replaced by F: two or more having 1 to 10 C atoms, in which, in addition, one or substituents Rhere optionally forms a mono- or poly more non-adjacent C atoms is optionally replaced by O cyclic aliphatic or aromatic ring system with one or S: another, Ar is on each occurrence, identically or differently, an n is on each occurrence, identically or differently, 0, 1 or 2. aromatic or heteroaromatic ring system having 5 to 60 65 2. The organic electroluminescent device according to aromatic ring atoms, which is optionally Substituted by claim 1, wherein Y is identically or differently on each occur one or more radicals R; rence, stands for a single bond or for a C(R) group. US 8,487,300 B2 63 64 3. The organic electroluminescent device according to -continued claim 1, wherein the group Y Ar-y, for n=0, stands for a (XII) group of the formulae (II) to CXV), where the dashed bond indicates the link to the imine nitrogen: R R R R (II) (XIII) R. R. 10

A. & w (III)

15 (XIV) R R w w A. w p w w (IV) R. R.

(XV) 25 (V) C - (VI) 30

/ N

p W Cf w w w (VII) 35 4. The organic electroluminescent device according to claim 1, wherein Ar", for n=1, stands for a group of the formulae (XVI) to (XXI), where the dashed bond indicates

W (A. ) the link to the imine nitrogen: w A. w w F (VIII) 40 R R (XVI)

45 COO (XVII) (IX)

OON (XVIII) (X) 55

(XIX) 60

(XI)

65 US 8,487,300 B2 65 66 -continued hole-blocking layers, electron-transport layers, electron-in (XX) jection layers, charge-generation layers and organic or inor O ganic pfnjunctions. 12. The organic electroluminescent device according to claim 1, wherein the organic electroluminescent device com prises a plurality of emitting layers, where at least one layer comprises at least one compound of the formula (I) and at (XXI) least one phosphorescent compound. 13. The organic electroluminescent device according to 10 claim 1, wherein the phosphorescent compound contains copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium. 14. The organic electroluminescent device according to 15 claim 12, wherein the phosphorescent compound comprises 5. The organic electroluminescent device according to claim 1, wherein Ar is identically or differently on each at least one compound of the formulae (XXII) to CXXV) occurrence, stands for an aryl or heteroaryl group having 5 to 16 aromatic ring atoms, which is optionally Substituted by (XXII) one or more radicals R. DCy A-Irg 6. The organic electroluminescent device according to CCy claim 1, wherein Ar is identically or differently on each 2 occurrence, stands for an aryl or heteroaryl group having 5 to (XXIII) DCy 16 aromatic ring atoms, which is optionally Substituted by 25 Irg one or more radicals R, selected from phenyl, 1- or 2-naph CCy thyl, 4-biphenyl, 1- or 2-anthryl, 2- or 3-thienyl, 2- or 3-pyr 3 rolyl, 2- or 3-furanyl, 2-, 3- or 4-pyridinyl, 3- or 4-pyridazi (XXIV) nyl, 4- or 5-pyrimidinyl, pyrazinyl, 2-, 3-, 4-, 5-, 6-, 7- or -PCy 8-quinolinyl or 3-, 4-, 5-, 6-, 7- or 8-isoquinolinyl, each of 30 A-PtC CCy which is optionally substituted by one or more radicals R. (XXV) 7. The organic electroluminescent device according to claim 1, wherein R is identically or differently on each occur rence, stands for F, N(R), Si(R), C(=O)R, P(=O)(R), a straight-chain alkyl group having 1 to 10 C atoms or a 35 branched or cyclic alkyl group having 3 to 10 C atoms, each of which is optionally substituted by one or more radicals R. wherein where one or more non-adjacent CH groups is optionally R is on each occurrence, identically or differently, H. F. Cl, replaced by RC=CR, O or S and one or more H atoms is Br, I, N(R), CN, NO, Si(R), B(OR), C(=O)R’, optionally replaced by F, oran aryl or heteroaryl group having 40 P(=O)(R), S(=O)R, S(=O),R, OSOR, a 5 to 16 aromatic ring atoms, each of which is optionally straight-chain alkyl, alkoxy or thioalkyl group having 1 substituted by one or more radicals R, or a combination of to 40 C atoms or a branched or cyclic alkyl, alkoxy or these systems; two or more substituents Rhere optionally thioalkyl group having 3 to 40 C atoms, each of which is form a mono- or polycyclic aliphatic or aromatic ring system optionally substituted by one or more radicals R, where with one another. 45 one or more non-adjacent CH2 groups is optionally 8. The organic electroluminescent device according to replaced by RC—CR, C=C, Si(R), Ge(R). claim 1, wherein R is identically or differently on each occur Sn(R), C=O, C-S, C-Se, C=NR, P(=O)(R), rence, stands for H, a straight-chain alkyl group having 1 to 6 SO, SONR, O.S or CONR and where one or more H C atoms or a branched or cyclic alkyl group having 3 to 6 C atoms is optionally replaced by F, Cl, Br, I, CN or NO, atoms, where in each case one or more H atoms is optionally 50 oran aromatic or heteroaromatic ring system having 5 to replaced by F, or for an aryl or heteroaryl group having 5 to 16 60 aromatic ring atoms, each of which is optionally aromatic ring atoms, each of which is optionally Substituted substituted by one or more radicals R, or an aryloxy or by one or more radicals R. heteroaryloxy group having 5 to 60 aromatic ring atoms, 9. The organic electroluminescent device according to which is optionally substituted by one or more radicals claim 1, wherein the compounds of the formula (I) are in the 55 R’, or a combination of these systems; two or more form of simple complexes or in dimeric or oligomeric form in Substituents Rhere optionally form a mono- or polycy the solid state. clic aliphatic or aromatic ring system with one another; 10. The organic electroluminescent device according to R’ is on each occurrence, identically or differently, H. For claim 1, wherein, in the compounds of the formula (I), all an aliphatic, aromatic or heteroaromatic hydrocarbon symbols Ari are identical, all symbols X are identical, all 60 radical having 1 to 20 Catoms, in which, in addition, one symbols R are identical, all symbols Y are identical and the or more Hatoms is optionally replaced by F: two or more compounds are identically substituted. substituents Rhere optionally forms a mono- or poly 11. The organic electroluminescent device according to cyclic aliphatic or aromatic ring system with one claim 1, wherein the organic electroluminescent device com another, prises cathode, anode and at least one emitting layer and 65 DCy is, identically or differently on each occurrence, a optionally comprises further layers selected from hole-injec cyclic group which contains at least one donor atom, via tion layers, hole-transport layers, electron-blocking layers, which the cyclic group is bonded to the metal, and which US 8,487,300 B2 67 68 optionally carries one or more Substituents R; the groups DCy and CCy are connected to one another via a cova lent bond; CCy is, identically or differently on each occurrence, a cyclic group which contains a carbonatom via which the cyclic group is bonded to the metal and which may in turn carry one or more Substituents R; A is, identically or differently on each occurrence, a monoanionic, bidentate chelating ligand. 15. The organic electroluminescent device according to 10 claim 12, wherein DCy is, identically or differently on each occurrence, a cyclic group which contains nitrogen orphosphorus, via which the cyclic group is bonded to the metal, and which optionally carries one or more Substituents R; the groups 15 DCy and CCy are connected to one another via a cova lent bond; and A is, identically or differently on each occurrence, a dike tonate ligand. 16. A process for the production of an organic electrolumi nescent device according to claim 1, which comprises apply ing one or more layers by means of a Sublimation process or by means of the OVPD (organic vapour phase deposition) process or by means of the OVJP (organic vapourjet printing) process or with the aid of carrier-gas Sublimation or are pro 25 duced from solution, by spin coating or by means of a printing process. 17. A matrix material for phosphorescent compounds in organic electroluminescent devices which comprises a com pound of the formula (I) according to claim 1. 30 k k k k k