CN1696137A - Complexes of red light iridium by using nitrogen heterocycles in quinoline as ligand, and application - Google Patents

Abstract

A red-light iridium match using quinoline-type azacyclic compound as its ligand is disclosed. It can be used to prepare the organic electroluminescent device emitting red light.

Description

Nitrogen heterocycles in quinoline is the complexes of red light iridium and the application thereof of part

Technical field

The present invention relates to based on nitrogen heterocycles in quinoline is the complex of iridium of part and as the application of red light material in organic electroluminescence device.

Technical background

People such as C.W.Tang had reported 8-hydroxyquinoline aluminum (Alq first in 1987 ₃) electro optical phenomenon since, the research of Organic Light Emitting Diode has caused the extensive interest of academia and industrial community.According to the spin statistical theory, in most Organic Light Emitting Diodes, the singlet exciton of generation and the ratio of triplet excitons are 1: 3.The essence that triplet excitons is prohibited owing to long life-span and spin shows as non-radiative decay, thereby the internal quantum efficiency that has limited device can not surpass 25%.And transition metal complex is because the heavy atoms effect of atoms metal, caused very strong spin-track coupling, thereby increased effective singlet to the intersystem crossing between the triplet state, promptly utilize transition metal complex can make full use of all form of energy that comprise singlet and triplet state as electroluminescent material, increase substantially the efficient of device, can make the internal quantum efficiency of device reach 100% in theory.

Transition metal complex as electroluminescent material mainly contains Ir (III), Pt (II), Os (II), Re (I), Cu heavy metal complexes such as (I) at present.Wherein complex of iridium is widely used in the electroluminescent device owing to having short life-span and higher efficient, and has realized that red-green-blue is luminous.

The glow color of complex of iridium depends on the structure of part strongly, and therefore, we can select suitable part to regulate glow color.At present, the part that is used to obtain efficient ruddiness in the complex of iridium mainly contains 2-(2-benzothienyl) pyridine and 1-phenyl isoquinolin quinoline etc.The synthetic method complexity of these parts, and be not easy a large amount of synthetic.Therefore, need the synthetic and relatively easy part of purifying of design to be used for complexes of red light iridium efficiently.

Summary of the invention

The purpose of this invention is to provide a kind of is the complexes of red light iridium electroluminescent material of part based on nitrogen heterocycles in quinoline.

The present invention has designed and synthesized a series of nitrogen heterocycles in quinoline as part, with iridium (III) coordination, forms title complex; And the method by vacuum evaporation or solution spin coating is complex doped in material of main part with iridium (III), and structure multilayer device or single layer device are realized efficient red emission.Compare with other ruddiness part, the quinoline part has synthetic and the characteristics such as easy of purifying, and corresponding title complex kept short life-span and higher efficient, for the structure high efficiency electroluminous device provides possibility.

Synthetic iridium of the present invention (III) title complex is monokaryon hexa-coordinate structure, has following basic structure:

In the general structure Representative is the bidentate ligand of ligating atom with carbon and nitrogen, has following structure:

Wherein, R ₁Be selected from aryl, the C6-C30 condensed aromatic ring yl of alkoxyl group, the C6-C30 of alkyl, the C1-C20 of hydrogen, fluorine, trifluoromethyl, cyano group, C1-C30, the heteroaryl of C2-C30; Ar1 is selected from a kind of in the following aromatic structure unit:

R wherein ₂, R ₄, R ₆Alkyl for C1-C30; R ₅Be hexyl or octyl group; R ₃Be the arbitrarily alkyl of the C1-C30 of the position of substitution or the alkoxyl group of C1-C20; R ₇Be selected from the alkyl of hydrogen, C1-C30, the alkoxyl group of C1-C20, the aryl of C6-C30; R ₈Be the alkyl of C1-C30 or the alkoxyl group of C1-C20; X is oxygen or sulphur atom.

The title complex that the present invention is above-mentioned, Ar1 preferentially are selected from a kind of in the following condensed ring aromatic structure unit:

R ₃Be the arbitrarily alkyl of the C1-C30 of the position of substitution or the alkoxyl group of C1-C20

The title complex that the present invention is above-mentioned has following structure:

The title complex that the present invention is above-mentioned has following structure:

All quinoline parts are all by Friedl  nder prepared in reaction.This reaction is with dense H ₂SO ₄Be catalyzer, HAc is a solvent with ice, back flow reaction 16-24 hour.Products obtained therefrom separates with recrystallization or post purifies.

All iridium (III) title complex all makes by two-step reaction.At first,

Part and iridous chloride reaction generate the intermediate of chloride bridge; Then, the chlorine bridge is replaced generation iridium (III) title complex by methyl ethyl diketone (acac).

According to the present invention, a kind of organic electroluminescence device has one or more layers organic thin layer that forms between first electrode and second electrode, and wherein one deck organic layer comprises one or more title complexs above-mentioned as the present invention at least

The luminescent layer of electroluminescent device can adopt the vacuum method preparation of evaporation altogether, technology is as follows: the while evaporation under vacuum condition with iridium (III) title complex and small molecules material of main part, by two independently the quartz crystal oscillator control separately vaporator rate, thereby control both content.Between anode ITO and luminescent layer, introduce hole transmission layer by vacuum vapour deposition simultaneously, between metallic cathode and luminescent layer, introduce one to two layer of organic molecule layer, the structure multilayer device with hole barrier or electric transmission function.Small molecules as material of main part comprises 4,4 '-N, N '-two carbazole biphenyl (CBP), 2-(4-phenylbenzene)-5-(4-tert-butyl-phenyl)-1,3,4-oxadiazole (PBD), 1,3,5-three (2-N-phenyl benzimidazolyl-) benzene (TPBI), 3-(4-phenylbenzene)-5-(4-tert-butyl-phenyl)-4-(4-ethylphenyl)-1,2,4-triazole (TAZ) etc.In luminescent layer, the weight ratio of iridium (III) title complex and material of main part is 1-9: 100.

The luminescent layer of electroluminescent device also can adopt the method preparation of solution spin coating, and technology is as follows: with iridium (III) title complex and the blend of polymer main body material, be dissolved in chloroform CHCl ₃In, be spin-coated on through polythiofuran derivative (PEDOT) and modify or, be prepared into luminescent layer without the ito glass surface of its modification.Polymer as material of main part comprises: the derivative of polystyrene support, polyhenylene, Polyvinyl carbazole, polycarbazole, poly-fluorenes or poly-fluorenes.The weight ratio of iridium (III) title complex and polymer main body material is 1-9: 100.In addition, can also further mix small molecules carrier transmission material: 2-(4-phenylbenzene)-5-(4-tert-butyl-phenyl)-1 in the luminescent layer, 3,4-oxadiazole (PBD), 1,3,5-three (2-N-phenyl benzimidazolyl-) benzene (TPBI), 3-(4-phenylbenzene)-5-(4-tert-butyl-phenyl)-4-(4-ethylphenyl)-1,2,4-triazole (TAZ), N, N '-two (3-aminomethyl phenyl)-N, N '-phenylbenzene-1,1 '-phenylbenzene-4,4 '-diamines (TPD) or N, N '-two (1-naphthyl)-N, N '-phenylbenzene-1,1 '-phenylbenzene-4,4 '-diamines (NPB).Load onto in set of devices, direct evaporation metal electrode behind the intact luminescent layer of spin coating is made single layer device; Also the vacuum available vapour deposition method further introduces one to two-layer organic molecule layer with hole barrier or electric transmission function between metal electrode and luminescent layer, the structure multilayer device.

Description of drawings

In conjunction with the accompanying drawings, will clearerly understand the present invention by the detailed description of exemplary embodiment, wherein:

Fig. 1 provides compound (1-NAPQ) ₂Ir (acac) and (TPAPQ) ₂The UV, visible light of Ir (acac) in dichloromethane solution absorbs (UV-Vib) spectrum and photoluminescence (PL) fluorescence Spectra;

Fig. 2 provides the brightness-voltage curve of the organic EL device of embodiment 2 manufacturings;

Fig. 3 provides the luminous efficiency of the organic EL device that embodiment 2 makes and the power efficiency change curve with brightness;

Fig. 4 provides the EL spectrum of embodiment 1 and 2 organic EL devices of making

Embodiment

Describe the present invention in detail with reference to following examples, following examples are illustrative purposes and do not plan to limit the scope of the invention.

＜reaction formula 1 〉

Synthetic embodiment 1: title complex (1-NAPQ) ₂Ir's (acac) is synthetic

(1) ligand 1-NAPQ's is synthetic

Adjacent aminobenzophenone of 1.97g (10mmol) and 1.70g (10mmol) 1-acetonaphthone are dissolved in the 15ml Glacial acetic acid, slowly drip the 0.1ml vitriol oil, stir reflux.React after 18 hours cool to room temperature.Reaction mixture is slowly poured in the mixing solutions of 40ml water and 15ml strong aqua composition.The precipitation of separating out is clamminess, and uses dichloromethane extraction, washing repeatedly, anhydrous Na ₂SO ₄Drying is filtered, and rotary evaporation falls solvent, and post separates purifies, and obtains 2.85g product (productive rate 86%).

(2) the chlorine bridge is dimeric synthetic

Get 1.46g (4.4mmol) ligand 1-NAPQ and 0.705g (2mmol) IrCl ₃3H ₂O adds in the 50ml round-bottomed flask; add ethylene glycol monomethyl ether 30ml again, distilled water 10ml takes a breath 3 times repeatedly; stirring heating under argon shield; be warming up to 130～140 ℃, behind the back flow reaction 36h, filter; the precipitation that obtains is with ethanol and distilled water wash; drying, post separates purification, gets dimer 1.28g (productive rate 72%)

(3) title complex (1-NAPQ) ₂Ir's (acac) is synthetic

Get dimer 0.89g (0.5mmol); methyl ethyl diketone (acac) 0.20g (2mmol), anhydrous sodium carbonate 0.53g (5mmol), ethylene glycol monoemethyl ether 30ml; add in the 50ml round-bottomed flask; take a breath repeatedly 3 times, stirring heating under argon shield is warming up to 130～140 ℃; behind the back flow reaction 24h; filter, the gained solid uses mixed solvent (sherwood oil/methylene dichloride=2/1) to carry out column chromatography for separation, obtains 500 milligrams of the finished product.(productive rate 53%)

(4) title complex (1-NAPQ) ₂The structural analysis of Ir (acac)

Determined the structure of this compound by NMR and ultimate analysis.

¹H?NMR(300MHz，CDCl ₃)：δ1.54(s，6H)，4.60(s，1H)，6.88(d，J＝8.2Hz，2H)，7.04(d，J＝8.4Hz，2H)，7.29(t，J＝7.4Hz，2H)，7.37-7.40(m，4H)，7.50(t，J＝7.6Hz，2H)，7.56-7.75(m，12H)，7.85(d，J＝7.2Hz，2H)，8.38(d，J＝8.6Hz，2H)，8.62(s，2H)，8.72(d，J＝8.5Hz，2H).

Theoretical value (C ₅₅H ₃₉N ₂O ₂Ir): C, 69.38; H, 4.13; N, 2.94. measured value: C, 69.30; H, 4.38; N, 2.69.

＜reaction formula 2 〉

Synthetic embodiment 2: title complex (TPAPQ) ₂Ir's (acac) is synthetic

Synthetic method and synthetic embodiment 1 are similar.

(1) part TPAPQ's is synthetic

Adjacent aminobenzophenone of 1.97g (10mmol) and 2.87g (10mmol) 4-diphenylamino methyl phenyl ketone are dissolved in the 15ml Glacial acetic acid, slowly drip the 0.1ml vitriol oil, stir reflux.React after 20 hours cool to room temperature.Reaction mixture is slowly poured in the mixing solutions of 40ml water and 15ml strong aqua composition.The precipitation of separating out is clamminess, and uses dichloromethane extraction, washing repeatedly, anhydrous Na ₂SO ₄Drying is filtered, and rotary evaporation falls solvent, and post separates purifies, and obtains 3.59g product (productive rate 80%).

(2) the chlorine bridge is dimeric synthetic

Get 1.97g (4.4mmol) ligand 1-NAPQ and 0.705g (2mmol) IrCl ₃3H ₂O adds in the 50ml round-bottomed flask; add ethylene glycol monomethyl ether 30ml again, distilled water 10ml takes a breath 3 times repeatedly; stirring heating under argon shield; be warming up to 130～140 ℃, behind the back flow reaction 48h, filter; the precipitation that obtains is with ethanol and distilled water wash; drying, post separates purification, gets dimer 1.46g (productive rate 65%)

(3) title complex (TPAPQ) ₂Ir's (acac) is synthetic

Get dimer 1.12g (0.5mmol); methyl ethyl diketone (acac) 0.20g (2.0mmol), anhydrous sodium carbonate 0.53g (5mmol), ethylene glycol monoemethyl ether 30ml; add in the 50ml round-bottomed flask; take a breath repeatedly 3 times, stirring heating under argon shield is warming up to 130～140 ℃; behind the back flow reaction 24h; filter, the gained solid column separates purifies, and obtains 530 milligrams of the finished product (productive rate 45%).

(4) title complex (TPAPQ) ₂The structural analysis of Ir (acac)

Determined the structure of this compound by NMR and ultimate analysis.

¹H?NMR(300MHz，CDCl ₃)：δ1.62(s，6H)，4.77(s，1H)，6.25(d，J＝2.1Hz，2H)，6.55(dd，J＝8.5，2.0Hz，2H)，6.80-6.91(m，20H)，7.42-7.59(m，16H)，7.68(s，2H)，7.74(d，J＝8.1Hz，2H)，8.58(d，J＝8.6Hz，2H)

Theoretical value (C ₇₁H ₅₃N ₄O ₂Ir): C, 71.88; H, 4.50; N, 4.72. measured value: C, 71.10; H, 4.49; N, 4.52.

Embodiment 1:

For the embodiment that provides, use title complex (1-NAPQ) ₂Ir (acac) is entrained in the CBP material of main part and makes organic EL device.At first, at the N of the surperficial evaporation 50nm that is coated with ito glass, N '-two (1-naphthyl)-N, N '-phenylbenzene-1,1 '-phenylbenzene-4,4 '-diamines (NPB) is as hole transmission layer.Then, deposition CBP forms the luminescent layer of 30nm on hole transmission layer, and 3% (1-NAPQ) wherein mixes ₂Ir (acac).At last, deposition goes up hole blocking layer (BCP:10mm), electron transfer layer (Alq successively ₃: 40nm), interfacial layer (LiF:1nm) and negative electrode (Al:100nm).

The El element of gained is at 100cd/m ²Brightness under, luminous efficiency is 2.2cd/A, external quantum efficiency is 3.0%, emission peak is at 642nm, peak width at half height is 35nm, chromaticity coordinates CIE value x=0.71, y=0.29.

Embodiment 2:

For this embodiment, use title complex (TPAPQ) ₂Ir (acac) is entrained in the CBP material of main part and makes organic EL device.At first, at the N of the surperficial evaporation 50nm that is coated with ito glass, N '-two (1-naphthyl)-N, N '-phenylbenzene-1,1 '-phenylbenzene-4,4 '-diamines (NPB) is as hole transmission layer.Then, deposition CBP forms the luminescent layer of 30nm on hole transmission layer, and 7% (TPAPQ) wherein mixes ₂Ir (acac).At last, deposition goes up hole blocking layer (BCP:10nm), electron transfer layer (Alq successively ₃: 40nim), interfacial layer (LiF:1nm) and negative electrode (Al:100nm).

The El element of gained is at 100cd/m ²Brightness under, luminous efficiency is 12.2cd/A, external quantum efficiency is 9.0%, emission peak is at 616nm, peak width at half height is 48nm, chromaticity coordinates CIE value x=0.67, y=0.32.

Claims (5)

1. complexes of red light iridium that nitrogen heterocycles in quinoline is a part has following basic structure:

In the general structure

Representative is the bidentate ligand of ligating atom with carbon and nitrogen, has following structure:

Wherein, R ₁Be selected from aryl, the C6-C30 condensed aromatic ring yl of alkoxyl group, the C6-C30 of alkyl, the C1-C20 of hydrogen, fluorine, trifluoromethyl, cyano group, C1-C30, the heteroaryl of C2-C30; Ar1 is selected from a kind of in the following aromatic structure unit:

R wherein ₂, R ₄, R ₆Alkyl for C1-C30; R ₅Be hexyl or octyl group; R ₃Be the arbitrarily alkyl of the C1-C30 of the position of substitution or the alkoxyl group of C1-C20; R ₇Be selected from the alkyl of hydrogen, C1-C30, the alkoxyl group of C1-C20, the aryl of C6-C30; R ₈Be the alkyl of C1-C30 or the alkoxyl group of C1-C20; X is oxygen or sulphur atom.

2. an organic electroluminescence device has one or more layers organic thin layer that forms between first electrode and second electrode, and wherein one deck organic layer comprises one or more title complexs as claimed in claim 1 at least.

3. title complex as claimed in claim 1, Ar1 preferentially are selected from a kind of in the following condensed ring aromatic structure unit:

R ₃Be the arbitrarily alkyl of the C1-C30 of the position of substitution or the alkoxyl group of C1-C20.

4. title complex as claimed in claim 1 has following structure:

5. title complex as claimed in claim 1 has following structure:

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