5,6-DIPHENYL-5,6-DIHYDRO-DIBENZ[C,E][1,2]AZAPHOSPHORIN AND 6-PHENYL-6H-DIBENZO[C,E][1,2]THIAZIN-5,5-DIOXIDE DERIVATIVES AND SIMILAR COMPOUNDS AS ORGANIC ELECTROLUMINESCENT MATERIALS FOR OLEDS

Abstract

The present invention relates to 5,6-diphenyl-5,6-dihydrodibenz[c,e][1,2]azaphosphorin and 6-phenyl-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide derivatives and similar compounds of the formula (1) as organic electroluminescent materials for use in organic electroluminescent devices, for example in organic light-emitting diodes (OLEDs), where the symbols used are as follows: Z is the same or different at each instance and is PAr.sup.2 or S(═O); E is the same or different at each instance and is O or S when the symbol Z to which this E binds is PAr.sup.2, and O when the symbol Z to which this E binds is S(═O); L is selected from the group consisting of a single bond, NAr.sup.2, O, S, S(═O).sub.2, P(═O)Ar.sup.2, —X═X— and —C(═O)—NAr.sup.2; the rest of the symbols are defined in the claims. The present invention discloses synthesis examples of inventive compounds, productions of OLEDs containing these example compounds, and results for these electroluminescent devices.

Claims

1. A compound of formula (1) ##STR00439## where the symbols used are as follows: Z is the same or different at each instance and is PAr.sup.2 or S(═O); E is the same or different at each instance and is O or S when the symbol Z to which this E binds is PAr.sup.2, and O when the symbol Z to which this E binds is S(═O); L is selected from the group consisting of a single bond, NAr.sup.2, O, S, S(═O).sub.2, P(═O)Ar.sup.2, —X═X— and —C(═O)—NAr.sup.2—; X is the same or different at each instance and is CR or N, where not more than two X groups per cycle are N; or two adjacent X are a group of the following formula (2), (3) or (4): ##STR00440## where the dotted bonds indicate the linkage of this group in the formula (1); Y is the same or different at each instance and is CR or N, where not more than two Y groups per cycle are N; Ar.sup.1, Ar.sup.2 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted by one or more R radicals, where Ar.sup.1 and Ar.sup.2 are not joined to one another, with the proviso that the substituents R that bind to Ar.sup.1 are not fluorine; A is the same or different at each instance and is NAr.sup.2, O, S or CR.sub.2; V is the same or different at each instance and is —NAr.sup.2—Z(=E)-; R is the same or different at each instance and is H, D, F, Cl, Br, I, N(Ar.sup.3).sub.2, OAr.sup.3, SAr.sup.3, CN, NO.sub.2, NAr.sup.3R.sup.1, N(R.sup.1).sub.2, OR.sup.1, SR.sup.1, COOR.sup.1, 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, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.1 radicals, where one or more nonadjacent CH.sub.2 groups may be 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 may be substituted in each case by one or more R.sup.1 radicals; at the same time, two R radicals together may also form an aliphatic or heteroaliphatic ring system; Ar.sup.3 is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 30 aromatic ring atoms and may be substituted by one or more R.sup.1 radicals; R.sup.1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R.sup.2).sub.2, CN, NO.sub.2, OR.sup.2, SR.sup.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, 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, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.2 radicals, where one or more nonadjacent CH.sub.2 groups may be 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 may be substituted in each case by one or more R.sup.2 radicals; at the same time, two or more R.sup.1 radicals together may form an aliphatic ring system; R.sup.2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; where the following compounds are excluded from the invention: ##STR00441## ##STR00442## ##STR00443##

2. A compound as claimed in claim 1, selected from the compounds of the formulae (1-1) and (5) to (16) ##STR00444## ##STR00445## ##STR00446## where X is the same or different at each instance and is CR or N, where not more than two X groups per cycle are N, and the further symbols used have the definitions given in claim 1.

3. A compound as claimed in claim 1, characterized in that the group of the formula (2), (3) or (4) is respectively selected from the groups of the formula (2a), (3a) or (4a): ##STR00447## where the symbols used have the definitions given above.

4. A compound as claimed in claim 1, characterized in that the symbols X that are not a group of the formula (2), (3) or (4) are the same or different at each instance and are CR, and in that the symbols Y are the same or different at each instance and are CR.

5. A compound as claimed in claim 1, selected from the structures of the formulae (1a) and (5a) to (16a), ##STR00448## ##STR00449## ##STR00450## where the symbols have the definitions given in claim 1.

6. A compound as claimed in claim 1, selected from the structures of the formulae (17) and (18): ##STR00451## where the symbols used have the definitions given in claim 1 and Z.sup.1 is PR.sup.1 or S(═O).

7. A compound as claimed in claim 1, selected from the structures of the formulae (1b) or (5b) to (16b): ##STR00452## ##STR00453## ##STR00454## where the symbols used have the definitions given in claim 1.

8. A compound as claimed in claim 1, characterized in that Z is PAr.sup.2 and E is O and L is a single bond.

9. A compound as claimed in claim 1, characterized in that Ar.sup.1 and Ar.sup.2 are the same or different at each instance and are an aromatic or heteroaromatic ring system which has 6 to 24 aromatic ring atoms and may be substituted by one or more R radicals, where the R radicals in the case of Ar.sup.1 are not fluorine.

10. A compound as claimed in claim 1, characterized in that R is the same or different at each instance and is selected from the group consisting of H, D, F, N(Ar.sup.3).sub.2, CN, OR.sup.1, a straight-chain alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, where the alkyl or alkenyl group may in each case be substituted by one or more R.sup.1 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by O, or an aromatic or heteroaromatic ring system which has 6 to 30 aromatic ring atoms and may be substituted in each case by one or more R.sup.1 radicals; at the same time, two R radicals together may also form an aliphatic ring system.

11. A formulation comprising at least one compound as claimed in claim 1 and at least one further compound and/or solvent.

12. The use of a compound as claimed in claim 1 in an electronic device.

13. An electronic device comprising at least one compound as claimed in claim 1.

14. An organic electroluminescent device, characterized in that the compound as claimed in claim 1 present in an emitting layer, especially as matrix material, and/or in an electron transport layer and/or in a hole blocker layer and/or in a hole transport layer and/or in an exciton blocker layer.

Description

EXAMPLES

Synthesis Examples

[0138] The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The solvents and reagents can be purchased from ALDRICH or ABCR. The numbers given for the reactants that are not commercially available are the corresponding CAS numbers.

a) 6-Chloro-5H-benzo[c][2,1]benzazaphosphinin

[0139] ##STR00192##

[0140] 8 g (50 mmol) of 2-aminobiphenyl in 70 ml of phosphorus trichloride is heated under reflux for 8 h, then the residual PCl.sub.3 is distilled off under reduced pressure, and the residue (Ar—NH—PCl.sub.2) is heated with 0.5 g of AlCl.sub.3 to 180-220° C. for 6 h. The mixture is dissolved in toluene and filtered through glass wool and hence separated from salts. Purification is effected by sublimation at 180-190° C. (0.05 mm) in the form of white needles that are very sensitive to hydrolysis. Yield: 4.2 g (24 mmol); 42% of theory; purity: 97% by NMR.

[0141] The following compounds can be prepared in an analogous manner:

TABLE-US-00001 Ex. Reactant Product Yield  1a [00193] [00194] 30%  2a [00195] [00196] 34%  3a [00197] [00198] 47%  4a [00199] [00200] 41%  5a [00201] [00202] 45%  6a [00203] [00204] 38%  7a [00205] [00206] 42%  8a [00207] [00208] 36%  9a [00209] [00210] 32% 10a [00211] [00212] 41% 11a [00213] [00214] 48%

b) 6-Phenyl-5H-benzo[c][2,1]benzazaphosphinin

[0142] ##STR00215##

[0143] Under protective gas, 4.2 g (24 mmol) of 6-chloro-5H-benzo[c][2,1]benzazaphosphinin is dissolved in 120 ml of dry toluene. This solution is added within 15 min to a phenyllithium solution, synthesized from 16.2 g (103 mmol) of bromobenzene and 1.5 g of lithium in 100 ml of ether, and boiled under reflux for 1 h. After cooling, the mixture is added to ice-water, and the organic phase is separated off. The organic phase is concentrated under reduced pressure, and the product is recrystallized from toluene. Yield: 3 g (11 mmol); 61% of theory; purity: 98% by NMR.

[0144] The following compounds can be prepared in an analogous manner:

TABLE-US-00002 Reactant Ex. Reactant 1 2 Product Yield 1b [00216] [00217] [00218] 64% 2b [00219] [00220] [00221] 61% 3b [00222] [00223] [00224] 56% 4b [00225] [00226] [00227] 50% 5b [00228] [00229] [00230] 62% 6b [00231] [00232] [00233] 47% 7b [00234] [00235] [00236] 63% 8b [00237] [00238] [00239] 59% 9b [00240] [00241] [00242] 66% 10b  [00243] [00244] [00245] 48% 11b  [00246] [00247] [00248] 62% [00249]

c) 5,6-Diphenylbenzo[c][2,1]benzazaphosphinin

[0145] ##STR00250##

[0146] An initial charge of 6.8 g (25 mmol, 1.00 eq.) of 6-phenyl-5H-benzo[c][2,1]benzazaphosphinin, 21.3 ml (128 mmol, 5.2 eq.) of iodobenzene and 7.20 g of potassium carbonate (52.1 mmol, 2.10 eq.) in 220 ml of dry DMF is inertized under argon. Subsequently, 0.62 g (2.7 mmol, 0.11 eq) of 1,3-di(2-pyridyl)propane-1,3-dione and 0.52 g (2.7 mmol, 0.11 eq) of copper(I) iodide are added and the mixture is heated at 140° C. for three days. After the reaction has ended, the mixture is concentrated cautiously on a rotary evaporator, and the precipitated solids are filtered off with suction and washed with water and ethanol. The crude product is purified twice by means of hot extraction (toluene/heptane 1:1), and the solids obtained are recrystallized from toluene. Yield: 4.5 g (12.8 mmol); 52% of theory.

[0147] The following compounds can be prepared in an analogous manner:

TABLE-US-00003 Reactant Ex. Reactant 1 2 Product Yield  1c [00251] [00252] [00253] 55%  2c [00254] [00255] [00256] 51%  3c [00257] [00258] [00259] 60%  4c [00260] [00261] [00262] 46%  5c [00263] [00264] [00265] 50%  6c [00266] [00267] [00268] 34%  7c [00269] [00270] [00271] 49%  8c [00272] [00273] [00274] 51%  9c [00275] [00276] [00277] 50% 10c [00278] [00279] [00280] 47% 11c [00281] [00282] [00283] 44% 12c [00284] [00285] [00286] 56% 13c [00287] [00288] [00289] 55% 14c [00290] [00291] [00292] 61% 15c [00293] [00294] [00295] 60% 16c [00296] [00297] [00298] 57% 17c [00299] [00300] [00301] 53% 18c [00302] [00303] [00304] 54% 19c [00305] [00306] [00307] 50% 20c [00308] [00309] [00310] 47% 21c [00311] [00312] [00313] 50% 22c [00314] [00315] [00316] 45% 23c [00317] [00318] [00319] 48% 24c [00320] [00321] [00322] 42% 25c [00323] [00324] [00325] 50%

[0148] Compounds 19c, 20c, and 22c-24c are purified by sublimation to a purity of 99.9%.

d) 5,6-Diphenylbenzo[c][2,1]benzazaphosphinin 6-oxide

[0149] ##STR00326##

[0150] 4.5 g (12.8 mmol) is dissolved in 40 ml of ethanol at room temperature, and 80 ml of H.sub.2O.sub.2 (30%) is added dropwise within 30 min. After stirring at 7000 for 1 h, 100 ml of dichloromethane is added to the solution, the phases are separated, the organic phase is concentrated and the product is crystallized from heptane/dichloromethane 2:1. Yield: 3.9 g (10.5 mmol); 93% of theory.

TABLE-US-00004 Ex. Reactant Product Yield 1d [00327] [00328] 94% 2d [00329] [00330] 91% 3d [00331] [00332] 94% 4d [00333] [00334] 90% 5d [00335] [00336] 89% 6d [00337] [00338] 74% 7d [00339] [00340] 90% 8d [00341] [00342] 89% 9d [00343] [00344] 92% 10c  [00345] [00346] 93% 11d  [00347] [00348] 91%

[0151] Compounds 1d-3d, 5d, 7d, 9d and 10d are recrystallized from toluene and finally fractionally sublimed twice (p about 10.sup.−6 mbar, T=330-450° C.).

e) 2-Bromo-5,6-diphenylbenzo[c][1,2]benzazaphosphinin 6-oxide

[0152] ##STR00349##

[0153] To a solution of 56 g (154 mmol) of 5,6-diphenylbenzo[c][2,1]benzazaphosphinin 6-oxide in chloroform (1000 ml) is added N-bromosuccinimide (24.7 g, 139 mmol) in portions at 0° C. with exclusion of light, and the mixture is stirred at this temperature for 2 h. The reaction is ended by addition of sodium sulfite solution and the mixture is stirred at room temperature for a further 30 min. After phase separation, the organic phase is washed with water and the aqueous phase is extracted with dichloromethane. The combined organic phases are dried over sodium sulfate and concentrated under reduced pressure. The residue is dissolved in toluene and filtered through silica gel. Subsequently, the crude product is recrystallized from toluene/heptane. Yield: 44 g (99 mmol); 65% of theory of a colorless solid.

[0154] The following compounds can be prepared in an analogous manner:

TABLE-US-00005 Reactant Product Yield 1e [00350] [00351] 67% 2e [00352] [00353] 68% 3e [00354] [00355] 80% 4e [00356] [00357] 79% 5e [00358] [00359] 77%

f) 5,6-Diphenyl-2-(9-phenylcarbazol-3-yl)benzo[c][1,2]benzazaphosphinin 6-oxide

[0155] ##STR00360##

[0156] 31 (70 mmol) of 2-bromo-5,6-diphenylbenzo[c][1,2]benzazaphosphinin 6-oxide, 20.8 g (75 mmol) of phenylcarbazole-3-boronic acid and 14.7 g (139 mmol) of sodium carbonate are suspended in 200 ml of toluene, 52 ml of ethanol and 100 ml of water. 80 mg (0.69 mmol) of tetrakistriphenylphosphinepalladium(0) are added to this suspension, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is removed, filtered through silica gel, washed three times with 200 ml of water and then concentrated to dryness. The residue is recrystallized from heptane/dichloromethane. The yield is 33 g (55 mmol); 79% of theory.

[0157] The following compounds can be obtained in an analogous manner:

TABLE-US-00006 Reactant 1 Reactant 2 Product Yield  1f [00361] [00362] [00363] 75%  2f [00364] [00365] [00366] 64%  3f [00367] [00368] [00369] 76%  4f [00370] [00371] [00372] 81%  5f [00373] [00374] [00375] 63%  6f [00376] [00377] [00378] 76%  7f [00379] [00380] [00381] 80%  8f [00382] [00383] [00384] 74%  9f [00385] [00386] [00387] 77% 10f [00388] [00389] [00390] 54% 11f [00391] [00392] [00393] 76% 12f [00394] [00395] [00396] 70% 13f [00397] [00398] [00399] 68% 14f [00400] [00401] [00402] 67% 15f [00403] [00404] [00405] 66% 16f [00406] [00407] [00408] 73% 17f [00409] [00410] [00411] 71% 18f [00412] [00413] [00414] 65% 19f [00415] [00416] [00417] 68% 20f [00418] [00419] [00420] 71%

Production of the OLEDs

[0158] Examples E1 to E9 which follow (see table 1) present the use of the materials of the invention in OLEDs.

Pretreatment for Examples E1-E9

[0159] Glass plaques coated with structured ITO (indium tin oxide) of thickness 50 nm are treated prior to coating with an oxygen plasma, followed by an argon plasma. These plasma-treated glass plates form the substrates to which the OLEDs are applied.

[0160] The OLEDs basically have the following layer structure: substrate/hole injection layer (HIL)/hole transport layer (HTL)/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 aluminum layer of thickness 100 nm. The exact structure of the OLEDs can be found in table 1. The materials required for production of the OLEDs are shown in table 2.

[0161] All materials are applied by thermal vapor 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 IC1:IC2:TEG1 (55%:35%:10%) mean here that the material IC1 is present in the layer in a proportion by volume of 55%, IC2 in a proportion by volume of 35% and TEG1 in a proportion by volume of 10%. Analogously, the electron transport layer may also consist of a mixture of two materials.

[0162] The OLEDs are characterized in a standard manner. The electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and the CIE 1931 x and y color coordinates are calculated therefrom.

Use of Mixtures of the Invention in OLEDs

[0163] The materials of the invention can be used as matrix material in the emission layer of phosphorescent green OLEDs. The results are collated in table 3.

TABLE-US-00007 TABLE 1 Structure of the OLEDs HIL HTL EBL EML HBL ETL EIL Ex. thickness thickness thickness thickness thickness thickness thickness E1 HATCN SpMA1 SpMA2 18c:IC2:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (64%:29%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E2 HATCN SpMA1 SpMA2 IC1:f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (47%:46%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E3 HATCN SpMA1 SpMA2 CbzT4:8f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (66%:22%:12%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E4 HATCN SpMA1 SpMA2 IC1:10f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (66%:22%:12%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E5 HATCN SpMA1 SpMA2 CbzT4:13f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (47%:46%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E6 HATCN SpMA1 SpMA2 15f:IC2:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (47%:46%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E7 HATCN SpMA1 SpMA2 IC1:17f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (44%:44%:12%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E8 HATCN SpMA1 SpMA2 CbzT4:18f:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (47%:46%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm E9 HATCN SpMA1 SpMA2 19f:IC2:TEG1 ST2 ST2:LiQ LiQ 5 nm 230 nm 20 nm (34%:59%:7%) 5 nm (50%:50%) 1 nm 40 nm 30 nm

TABLE-US-00008 TABLE 2 Structural formulae of the materials for the OLEDs [00421] HATCN [00422] SpMA1 [00423] SpMA3 [00424] ST2 [00425] TEG1 [00426] LiQ [00427] IC1 [00428] IC2 [00429] CbzT4 [00430] 18c [00431] f [00432] 8f [00433] 10f [00434] 13f [00435] 15f [00436] 17f [00437] 18f [00438] 19f

TABLE-US-00009 TABLE 3 Results for the electroluminescent devices U1000 SE1000 EQE 1000 CIE x/y at Ex. (V) (cd/A) (%) 1000 cd/m.sup.2 E1 3.3 68 19 0.36/0.61 E2 3.5 73 18 0.35/0.62 E3 3.4 72 17 0.34/0.62 E4 3.5 69 18 0.35/0.61 E5 3.2 73 17 0.35/0.62 E6 3.4 73 17 0.35/0.62 E7 3.7 65 16 0.32/0.63 E8 3.5 63 16 0.33/0.63 E9 3.1 60 19 0.33/0.63