DE10239549A1 - Luminescent mixture, used in organic LED, e.g. for car, mobile telephone or notebook picture screen, contains polyfluorene, poly-(p-phenylene-vinylene), poly(p-phenylene) or polythiophene compound and heavy metal compound - Google Patents

Abstract

Luminescent mixtures of (1) organic polymer(s) and (2) compound(s) of heavy metals of atomic weight not less than 50 comprise (1a) poly-(p-phenylene-vinylene) compounds and (2a) compound(s) of series 1-3 transition metals, main group 3, 4 and 5 metals of periods 5 and 6 and lanthanides, except platinum; (1b) polyfluorene, poly(p-phenylene) and polythiophene compounds and (2b) compound(s) of copper, zinc and main group 3, 4 and 5 metals of period 6.

Description

The present invention relates to new luminescent mixtures containing at least one organic Polymer selected from the group consisting of polyfluorene compounds (A), poly (pphenylene vinylene) compounds (B), poly (p-phenylene) compounds (C) and polythiophene compounds (D), and containing at least one heavy metal compound, in Case of compound class (B), a heavy metal, its atomic weight is at least 50 and selected that is from the group consisting of the 1st to 3rd row of transition metals, the metals of the 3rd, 4th and 5th main group of the 5th and 6th period of the periodic table of the elements and the lanthanides, whereby platinum compounds are excluded, and in the case of connection classes (A), (C) and (D), a heavy metal whose atomic weight is at least 50 and that selected is from the group consisting of copper, zinc and the metals the 3rd, 4th and 5th main group of the 6th period of the periodic table of the elements, as well as their use for the production of organic light emitting diodes (LED).

LEDs are well known and e.g. in Angew. Chem. 1998, 110, 416-443, described. They are applicable in many areas, e.g. in monochrome, multi-color or full-color screens (for example in applications in automobiles, mobile phones or notebooks).

From Adv. Mater., 1999, 11, 285-288 Mixtures of poly [4- (N-4-vinylbenzyloxyethyl, N-methylamino) -N- (2,5-di-tert-butylphenylnaphthalimide)] with platinum octaethylporphyrin and their use in the manufacture known from organic LED. However, it has been shown that the Mixtures described there still have disadvantages, for example the relatively long lifetime of the triplet emission from the platinum complex of 80 μs.

WO 01/96454 describes photoluminescent and electroluminescent compositions with an aromatic Matrix and luminescent metal ions or luminescent metal complexes.

Object of the present invention it was now to provide new mixtures that turned out to be more advantageous Suitable for the production of organic LED.

Accordingly, those specified at the outset were specified Mixtures found.

The luminescent mixtures according to the invention contain at least one organic, preferably electroluminescent organic polymer selected from the group consisting of polyfluorene compounds (A), poly (p-phenylene vinylene) compounds (B), poly (p-phenylene) compounds (C) and polythiophene compounds (D).

The organic polymers contained in the mixtures according to the invention generally have an average molecular weight of 10 ³ to 10 ⁷ g / mol, based on polystyrene standards, determined by gel permeation chromatography.

They preferably contain the structural elements of formulas I to IV:

Fluorene elements of formula I.

wherein
Ar ¹ C ₆ -C ₂₀ arylene, preferably C ₆ -C ₁₀ arylene, C ₄ -C ₂₀ heteroarylene, preferably C ₄ -C ₁₀ heteroarylene, or a divalent radical of a triarylamine with 18 to 60, preferably 18 to 30 carbon atoms linked by carbon-carbon bonds,
R ¹ and R ² independently of one another are each C ₁ -C ₁₃ alkyl which can be interrupted by one or more oxygen or sulfur atoms or by one or more imino or C ₁ -C ₄ alkylimino groups, or C ₂ -C ₁₃ -Alkoxy, and
m and n each represent 0 to 1, with the proviso that the sum of m and n is 1;

p-Phenylene vinylene elements of the formula II

wherein
A ¹ and A ² are each independently hydrogen or cyano,
Ar ² C ₆ -C ₂₀ arylene, preferably C ₆ -C ₁₀ arylene, C ₄ -C ₂₀ heteroarylene, preferably C ₄ -C ₁₀ heteroarylene, or a divalent radical of a triarylamine with 18 to 60, preferably 18 to 30 carbon atoms linked by carbon-carbon bonds,
R ³ and R ⁴ each independently of one another are C ₁ -C ₁₃ alkyl which can be interrupted by one or more oxygen or sulfur atoms or by one or more imino or C ₁ -C ₄ alkylimino groups, C ₁ -C ₁₃ - Alkoxy, C ₄ -C ₁₆ acyl or tri (C ₄ -C ₁₆ alkyl) siloxy, and
p and q each represent 0 to 1, with the proviso that the sum of p and q is 1;

p-phenylene elements of formula III

worin
Ar⁴ C₆-C₂₀-Arylen, vorzugsweise C₆-C₁₀-Arylen, C₄-C₂₀-Heteroarylen, vorzugsweise C₄-C₁₀-Heteroarylen, oder einen divalenten Rest eines Triarylamins mit 18 bis 60, vorzugsweise 18 bis 30 Kohlenstoffatomen, der über Kohlenstoff-Kohlenstoff-Bindungen verknüpft ist,
R⁷ und R⁸ unabhängig voneinander jeweils C₁-C₁₃-Alkyl, das durch eines oder mehrere Sauerstoff- oder Schwefelatome oder durch eine oder mehrere Imino- oder C₁-C₄-Alkyliminogruppen unterbrochen sein kann, C₁-C₁₃-Alkoxy, C₄-C₁₆-Acyl oder Tri(C₄-C₁₆-alkyl)siloxy, und
t und u jeweils 0 bis 1 bedeuten, mit der Maßgabe, dass die Summe aus t und u 1 beträgt.wherein
Ar ³ C ₆ -C ₂₀ arylene, preferably C ₆ -C ₁₀ arylene, C ₄ -C ₂₀ heteroarylene, preferably C ₄ -C ₁₀ heteroarylene, or a divalent radical of a triarylamine with 18 to 60, preferably 18 to 30 carbon atoms linked by carbon-carbon bonds,
R ⁵ and R ⁶ each independently of one another are C ₁ -C ₁₃ alkyl which can be interrupted by one or more oxygen or sulfur atoms or by one or more imino or C ₁ -C ₄ alkylimino groups, C ₁ -C ₁₃ - Alkoxy, C ₄ -C ₁₆ acyl or tri (C ₄ -C ₁₆ alkyl) siloxy, and
r and s each represent 0 to 1, with the proviso that the sum of r and s is 1; and thiophene elements of formula IV

wherein
Ar ⁴ C ₆ -C ₂₀ arylene, preferably C ₆ -C ₁₀ arylene, C ₄ -C ₂₀ heteroarylene, preferably C ₄ -C ₁₀ heteroarylene, or a divalent radical of a triarylamine with 18 to 60, preferably 18 to 30 carbon atoms linked by carbon-carbon bonds,
R ⁷ and R ⁸ each independently of one another are C ₁ -C ₁₃ alkyl which can be interrupted by one or more oxygen or sulfur atoms or by one or more imino or C ₁ -C ₄ alkylimino groups, C ₁ -C ₁₃ - Alkoxy, C ₄ -C ₁₆ acyl or tri (C ₄ -C ₁₆ alkyl) siloxy, and
t and u each represent 0 to 1, with the proviso that the sum of t and u is 1.

Organic polymers of the formulas I to IV with the structural elements mentioned above are known per se and are described, for example, in Adv. Mater., 2000, 12, 1737-1750, Angew. Chem., 1998, 110, 416-443, Adv. Mater., 1999, 11, 241-246, US-A-5 777 070 . EP-A-1 134 269 and Nature, 1999, 397, 121-128.

Important organic polymers are e.g. Polyfluorene compounds (A), the structural elements of the formula I have poly (pphenylene vinylene) compounds (B), the structural elements of formula II, poly (p-phenylene) compounds (C), the structural elements of formula III, and polythiophene compounds (D), the Have structural elements of formula IV.

This can be the case with the polymers of the formula I, II, III and IV both homopolymers and copolymers act.

Organic polymers are preferred, the selected are from the group consisting of polyfluorene compounds (A), in particular those which have structural elements of the formula I, and poly (p-phenylene vinylene) compounds (B), in particular those have the structural elements of formula II, wherein poly (p-phenylene vinylene) compounds (B), in particular those which have structural elements of the formula II, particularly are to be emphasized.

Organic polymers which may be mentioned are, in particular, homopolymers which have structural elements of the formula I in which R ¹ and R ^{2 are} each, independently of one another, C ₁ -C ₁₀ -alkyl, in particular butyl, hexyl or 2-ethylhexyl, and the copolymers analogous thereto Formula I, in the manner of a divalent radical of a triphenylamine, a thiophene or a carbazole, and homopolymers of the formula II, in which R ³ and R ⁴ each have C ₁ -C ₈ alkoxy, in particular methoxy and 2-ethylhexyloxy, or tri (C ₁ -C ₈ alkyl) silyl, and the copolymers of formula II, in which Ar ^{2 is} a divalent radical of a triphenylamine, a thiophene or a carbazole.

The organic polymers used generally have an electrical conductivity of at least 10 ^-9 S / cm, preferably at least 10 ^-7 S / cm and in particular of at least 10 ^-6 S / cm.

The luminescent mixtures according to the invention can also mixtures of the above closer have designated organic polymers with each other.

In the luminescent in the invention Mixtures containing organic polymers are in generally about compounds known per se, such as e.g. in adv. Mater, 2000, 12, 1737, and Angew. Chem., 1998, 110, 416-443 are.

The luminescent mixtures according to the invention also contain at least one heavy metal compound, with a heavy metal whose atomic weight is at least 50, preferably is at least 63.

In the case of connection class (B), the heavy metal is selected from the group consisting of the 1st to 3rd row of transition metals, the metals of the 3rd, 4th and 5th main group of the 5th and 6th period of the Periodic table of the elements and the lanthanides, being platinum compounds with exception of.

In the case of connection classes (A), (C) and (D) is the heavy metal selected from the group consisting of made of copper, zinc and the metals of the 3rd, 4th and 5th main group the 6th period of the Periodic Table of the Elements.

In the case of connection class (B) preferred heavy metals are those selected from the group consisting of from the lanthanides, copper, rhenium, osmium, iridium, gold, thallium, Lead and bismuth, whereby europium, terbium, copper, rhenium, iridium, Gold, lead and bismuth are particularly noteworthy.

In the case of connection classes (A), (C) and (D) preferred heavy metals are those selected from the group consisting of copper, zinc, thallium, lead and bismuth, copper, lead and bismuth are particularly noteworthy.

As heavy metal compounds are organic heavy metal complexes in particular.

worin
T¹, T² und T³ unabhängig voneinander jeweils C₁-C₁₃-Alkyl, C₆-C₁₂-Aryl oder C₄-C₁₀-Heteroaryl oder jeweils T¹ und T² oder T² und T³, zusammen mit den Kohlenstoffatomen an die sie gebunden sind, einen 5- bis 7-gliedrigen gesättigten oder ungesättigten Carbocyclus oder Heterocyclus bedeuten.Complexing agents for such heavy metal complexes are preferably derived from compounds selected from the group consisting of 2,2'-bipyridyl, 1,10-phenanthroline, 2-pyridinecarboxylate (pic), 2-carbaldehydimino-phenolate (sal) and from 1,3-dicarbonyl compounds, especially those of formula V

wherein
T ¹ , T ² and T ³ independently of one another in each case C ₁ -C ₁₃ alkyl, C ₆ -C ₁₂ aryl or C ₄ -C ₁₀ heteroaryl or in each case T ¹ and T ² or T ² and T ³ , together with the carbon atoms to which they are attached mean a 5- to 7-membered saturated or unsaturated carbocycle or heterocycle.

further complexing agents are selected from the group consisting of 2-phenylpyridine (ppy), 2- (4-tolyl) pyridine (tpy), 1-phenanthridine (bzq), 2- (2-thienyl) pyridine (thp), 2- (2-benzo [b] thiophenyl) pyridine (btp), 2,5-diphenyloxazole (dpo), 2- (2-oxo-7-diethylamino-3-benzo [b] pyranyl) benzothiazole (C6), 2-phenylbenzoxazole (bo), 2-phenylbenzthiazole (bt), 2- ( 1-naphthyl) benzoxazole (bon), 2-phenyl-4,5-dihydrooxazole (op), 2- (1-naphthyl) benzthiazole (absn), 2- (2-naphthyl) benzthiazole (βbsn), 2- (2 -Thienyl) benzthiazole (btth) and 2-phenylquinoline (pq).

worin
E¹ bis E⁸ unabhängig voneinander jeweils Wasserstoff, C₁-C₁₃-Alkyl, C₆-C₁₂-Aryl oder C₄-C₁₀-Heteroaryl,
E⁹ und E¹⁰ unabhängig von einander jeweils C₁-C₁₃-Alkyl, C₆-C₁₂-Aryl, C₄-C₁₀-Heteroaryl, C₁-C₁₃-Alkoxy, Halogen, Cyano oder Thiocyanato,
E¹¹ und E¹² unabhängig voneinander jeweils C₁-C₁₃-Alkyl, C₆-C₁₂-Aryl oder C₄-C₁₀-Heteroaryl,
E¹³, E¹⁴ und E¹⁵ unabhängig voneinander jeweils C₁-C₁₃-Alkyl, C₆-C₁₂-Aryl oder C₄-C₁₀-Heteroaryl oder jeweils E¹³ und E¹⁴ oder E¹⁴ und E¹⁵, zusammen mit den Kohlenstoffatomen an die sie gebunden sind, einen 5- bis 7-gliedrigen gesättigten oder ungesättigten Carbocyclus oder Heterocyclus,
L¹ einen zweizähnigen Liganden, insbesondere 2,2'-Bipyridyl oder 1,10-Phenanthrolin,
L 2-Phenylpyridin oder 2-Phenybenzoxazol,
M ein oben näher definiertes Schwermetall,
M¹ Europium oder Terbium,
X und Y unabhängig voneinander jeweils Sauerstoff, Schwefel Imino, C₁-C₁₀-Alkylimino oder C₆-C₁₂-Arylamino,
Z Stickstoff oder Phosphor und
w 1 bis 3 bedeuten.Metal complexes of the formulas VI to XVIII are also suitable:

wherein
E ¹ to E ⁸ each independently of one another are hydrogen, C ₁ -C ₁₃ alkyl, C ₆ -C ₁₂ aryl or C ₄ -C ₁₀ heteroaryl,
E ⁹ and E ¹⁰ each independently of one another are C ₁ -C ₁₃ alkyl, C ₆ -C ₁₂ aryl, C ₄ -C ₁₀ heteroaryl, C ₁ -C ₁₃ alkoxy, halogen, cyano or thiocyanato,
E ¹¹ and E ¹² independently of one another in each case C ₁ -C ₁₃ alkyl, C ₆ -C ₁₂ aryl or C ₄ -C ₁₀ heteroaryl,
E ¹³ , E ¹⁴ and E ¹⁵ independently of one another in each case C ₁ -C ₁₃ alkyl, C ₆ -C ₁₂ aryl or C ₄ -C ₁₀ heteroaryl or in each case E ¹³ and E ¹⁴ or E ¹⁴ and E ¹⁵ , together with the carbon atoms to which they are attached, a 5- to 7-membered saturated or unsaturated carbocycle or heterocycle,
L ^{1 is} a bidentate ligand, in particular 2,2'-bipyridyl or 1,10-phenanthroline,
L 2-phenylpyridine or 2-phenybenzoxazole,
M is a heavy metal defined in more detail above,
M ¹ europium or terbium,
X and Y each independently of one another oxygen, sulfur imino, C ₁ -C ₁₀ alkylimino or C ₆ -C ₁₂ arylamino,
Z nitrogen or phosphorus and
w is 1 to 3.

Such complex ligands and metal complexes are known per se and e.g. in J. Am. Chem. Soc. 123, 2001, 4304-4312, Inorg. Chem. 40, 2001, 1704-1712, Adv. Mater. 2000, 12, 1591-1594, Adv. Mater. 2001, 13, 1245, WO 99/53724, WO 00/57676, WO 01/08230, WO 01/39234 and WO 01/41512 described.

All in the formulas listed here contained alkyl residues can be both straight and branched.

Examples of alkyl radicals are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, 2-methylpentyl, heptyl, octyl, 2-ethylhexyl, isooctyl, nonyl , Isononyl, decyl, isodecyl, undecyl, dodecyl, tridecyl or isotridecyl. (The above designations isooctyl, isononyl, isodecyl and isotridecyl are trivial names derived from those obtained by the oxo process alcohols -.. Cf. Ullmann's Encyclopedia of Industrial Chemistry, ^5th Edition, Vol A1, pp 290-293, and vol A 10, pages 284 and 285.)

Alkyl radicals which are interrupted by one or more oxygen or sulfur atoms or by one or more imino or C ₁ -C ₄ -alkylimino groups are, for example, 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-butoxyethyl, 2- or 3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 3,7-dioxaoctyl, 4,7-dioxaoctyl, 2- or 3-butoxypropyl or 2- or 4-butoxybutyl or the corresponding radicals which have sulfur atoms, imino or, for example, methyl or ethylimino groups instead of the oxygen atoms.

Alkoxy residues are e.g. Methoxy, ethoxy, Propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy tert-butyl, pentyloxy, Isopentyloxy, neopentyloxy, tert-pentyloxy, hexyloxy, 2-methyloxypentyloxy, Heptyloxy, octyloxy, 2-ethyloxyhexyloxy, isooctyloxy, nonyloxy, Isononyloxy, decyloxy, isodecyloxy, undecyloxy, dodecyloxy, tridecyloxy or isotridecyloxy.

Aryl residues are e.g. Phenyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-ethylphenyl, 2,4-dimethylphenyl, naphthyl or 2-methylnaphthyl.

Arylene residues are e.g. Phenylene, 2-, 3- or 4-methylphenylene, 2-, 3- or 4-ethylphenylene, 2,4-dimethylphenylene, Naphthylene or 2-methylnaphthylene.

Heteroaryl or heteroarylene residues derive e.g. from the following heterocycles: pyrrole, furan, thiophene, Pyridine, pyrimidine, triazine, indole, benzofuran, benzoxazole, benzthiazole, Quinoline or isoquinoline.

Acyl radicals are, for example, butanoyl, isobutanoyl, sec-butanoyl, pentanoyl, isopentanoyl, neopentanoyl, hexanoyl, 2-methylpentanoyl, heptanoyl, octanoyl, 2-ethylhexanoyl, isooctanoyl, nonanoyl, isononanoyl, dec noyl, isodecanoyl, undecanoyl, dodecanoyl, tridecanoyl, isotridecanoyl, tetradecanoyl, pentadecanoyl or hexadecanoyl.

They are of particular importance Ligands 2,2'-bipyridyl, 1,10-phenanthroline, 2-phenylpyridine, 2-phenylbenzoxazole (bo) and 1,3-dicarbonyl compounds, especially those of the formula V.

The luminescent mixtures according to the invention can also mixtures of the above closer have designated heavy metal compounds.

Luminescent mixtures are preferred, containing at least one heavy metal complex with an above defined in more detail Heavy metal and a complexing agent that differs from an organic Connection selected from the group consisting of 2,2'-bipyridyl, 1,10-phenanthroline, 2-phenylpyridine, 2-phenylbenzoxazole (bo) and ligands of the formula V, derives.

Other ingredients included in the luminescent according to the invention Mixtures can be contained are z. B. dopants such as fluorescent dyes, for example the dyes of the formulas XIX and XX mentioned below.

The proportion of organic polymers in the luminescent according to the invention Blends is in generally 70 to 99.999% by weight, preferably 85 to 99.99% by weight and in particular 95 to 99.9% by weight, in each case based on the total weight the mixture.

The proportion of heavy metal compounds in the luminescent according to the invention Mixtures usually 0.01 to 30% by weight, preferably 0.1 to 20% by weight and in particular 0.5 to 15% by weight, in each case based on the total weight the mixture.

The share of the other above Components in the luminescent mixtures according to the invention is usually 0 to 5.0% by weight, preferably 0 to 2.0% by weight, each based on the total weight of the mixture.

The luminescent mixtures according to the invention can can be obtained in a manner known per se. For example, by usual Mixing the organic polymers with the heavy metal complexes and optionally with the ones above designated other components.

The mixtures according to the invention containing at least one organic polymer and at least one heavy metal complex are luminescent. That means that after energetic stimulation e.g. to emit light through light and electricity.

Another subject of the present The invention is the use of the luminescent mixtures according to the invention as an organic LED.

Organic LEDs are usually constructed so that there are organic, electroluminescent compounds containing layer with a thickness of 20 to 200 nm between a Anode and a cathode is located. The mixture according to the invention is preferably located between the two electrodes. The is particularly preferred mixture according to the invention between a hole and an electron transporting layer.

Claims (5)

Luminescent mixtures containing at least one organic polymer selected from the group consisting of polyfluorene compounds (A), poly (p-phenylene vinylene) compounds (B), poly (p-phenylene) compounds (C) and polythiophene compounds (D), and at least one heavy metal compound containing, in the case of compound class (B), a heavy metal whose atomic weight is at least 50 and which is selected from the group consisting of the 1st to 3rd row of transition metals, the metals of the 3rd, 4th and 5th main group of the 5th and 6th period of the periodic table of the elements and the lanthanides, with the exception of platinum compounds, and in the case of the compound classes (A), (C) and (D) Heavy metal, the atomic weight of which is at least 50 and which is selected from the group consisting of copper, zinc and the metals of the 3rd, 4th and 5th main group of the 6th period of the Periodic Table of the Elements. Luminescent mixtures according to claim 1, characterized in that that they contain at least one heavy metal compound Heavy metal, the atomic weight of which is at least 63, contain. Luminescent mixtures according to claim 1, characterized in that that they contain at least one heavy metal complex, whereby the complexing agent of organic compounds, selected from the group consisting of 2,2'-bipyridyl, 1,10-phenanthroline, 2-phenylpyridine, 2-phenylbenzoxazole (bo) and 1,3-dicarbonyl compounds. Luminescent mixtures according to claim 1, characterized in that that, based on the total weight of the mixture, 95 up to 99.9% by weight of at least one organic polymer and 0.01 to 30 Wt .-% contain at least one heavy metal compound. Use of the luminescent mixtures according to claim 1 for the production of organic light emitting diodes.