CN111848329A

CN111848329A - Anthracene derivative and preparation method and application thereof

Info

Publication number: CN111848329A
Application number: CN202010668887.7A
Authority: CN
Inventors: 陈文铖; 邱志鹏; 霍延平; 李振声
Original assignee: Guangdong University of Technology
Current assignee: Guangdong University of Technology
Priority date: 2020-07-13
Filing date: 2020-07-13
Publication date: 2020-10-30

Abstract

The invention discloses an anthracene derivative and a preparation method and application thereof. The anthracene derivative is prepared by mixing bromoanthracene, tetraphenylnaphthalene boric acid and a catalyst, and reacting in an environment with strong alkali and under the protection of inert gas. The introduction of the tetraphenyl naphthalene group enables the injection and transmission of carriers of the anthracene derivative to be more balanced, and the charge transfer effect between the electron donor and the electron acceptor is balanced, so that the deep blue emission of the anthracene derivative can be maintained while the high fluorescence quantum efficiency of the solid film in an aggregation state is realized, and the organic light-emitting micromolecule with good carrier transmission capability and high fluorescence quantum yield in the aggregation state is synthesized.

Description

Anthracene derivative and preparation method and application thereof

Technical Field

The invention relates to the field of organic luminescent materials, in particular to an anthracene derivative and a preparation method and application thereof.

Background

With the rise of high-tech products such as large-screen smart phones, tablet computers, wearable devices and the like, the traditional liquid crystal display material is more and more difficult to meet the requirements of mobile terminals on increasingly light weight, thinness and low consumption of display screens. People are beginning to pay attention to organic electroluminescent devices having advantages of higher flexibility, thinner thickness, lower power consumption, wider viewing angle, higher color saturation, and the like. The OLED device has decisive significance for display technologies such as full-color display and solid-state light emission. Although there are many reports on anthracene-based light-emitting materials used in small-molecule organic electroluminescent devices, in most cases, in an aggregate state, due to the fact that pi-pi accumulation is formed in a planar structure of molecules, fluorescence is quenched, and thus efficiency of the device is reduced.

The anthracene luminescent material modified by the traditional group has the defects of unbalanced carrier transmission and poor device performance of a device taking the anthracene luminescent material as a luminescent layer due to the common electron transmission and hole transmission capability of the molecule. And because of the over-strong electron-donating or electron-withdrawing capability between the modifying group and the anthracene group, the modified molecule has serious self intramolecular charge transfer phenomenon, so that the modified molecule has insufficient color purity due to red shift of luminescence, and the application of the material is influenced. Chinese patent CN108586367A discloses an organic luminescent material, which is a connecting structure of asymmetric anthracene and triazine with good electron transport performance, and is obtained by modifying an anthracene derivative-containing structure, but the prepared organic luminescent material far does not reach the deep blue emission of an international standard OLED device (x + y is less than 0.30). Chinese patent CN 101400643a discloses a tetraphenylnaphthalene derivative, and in the examples, each organic light emitting device prepared using the tetraphenylnaphthalene derivative disclosed in the patent observed only 3700 nit of blue light emission at the maximum under the condition of applying a forward electric field of 8.1V.

Therefore, there is an urgent need to develop an anthracene-based light emitting material having both good carrier transport ability and high blue light color purity.

Disclosure of Invention

The invention provides an anthracene derivative for overcoming the defects that the prior art is difficult to consider both good carrier transmission capability and high blue light color purity of a luminescent material. The anthracene derivative can effectively improve pi electron delocalization, so that carrier injection and transmission are more balanced, the fluorescence quantum efficiency of the anthracene derivative is improved, and the high fluorescence quantum efficiency of a solid film aggregation state can be realized while organic solvent efficiently emits deep blue light.

Another object of the present invention is to provide a process for producing the anthracene derivative.

Still another object of the present invention is to provide use of the above anthracene derivative as a light emitting material in an organic light emitting device.

In order to solve the technical problems, the invention adopts the technical scheme that:

an anthracene derivative having a general structural formula of formula (I):

wherein R is

The anthracene derivative has a donor-pi-acceptor structure; wherein the tetraphenylnaphthalene unit is used as an electron acceptor, and the anthracene is used as an electron donor, so that the phenomenon of efficiency reduction caused by strong charge transfer can be avoided. The tetraphenylnaphthalene molecule has good electron transport performance and hole transport performance, can effectively balance the injection and transport capabilities of the current carrier of the device with the anthracene derivative as a luminescent layer, and has high color purity.

The invention also provides a preparation method of the anthracene derivative, which comprises the following steps:

mixing p-bromo-naphthalene anthracene or bis-p-bromo-anthracene, tetraphenylnaphthalene boric acid with a catalyst, preparing mixed liquor containing anthracene derivatives by Suzuki reaction (Suzuki reaction) in the presence of strong alkali under the protection of inert gas, and extracting and purifying to obtain the anthracene derivatives.

The catalyst is a palladium catalyst.

Preferably, the catalyst is palladium tetratriphenylphosphine.

Preferably, the strong base is potassium carbonate or sodium carbonate.

In the Suzuki reaction, an organic boron compound is activated by alkali to be a borate intermediate in the presence of alkali, so that organic molecules are easily transferred from boron atoms to palladium atoms to construct carbon-carbon single bonds. The whole reaction condition is mild, the byproducts are few, the toxicity is low, and a large number of functional groups in the raw material compound can stably exist without being damaged, so that the high-selectivity chemical catalyst has high chemical selectivity.

Preferably, the addition molar ratio of the para-bromo-naphthalene anthracene to the tetraphenyl naphthalene-boric acid to the catalyst is 1: 1-2: 0.05-0.1.

More preferably, the para-bromo-naphthalene anthracene, tetraphenylnaphthalene-boronic acid and catalyst are added in a molar ratio of 1:1.5: 0.07.

Preferably, the addition molar ratio of the bis-para-bromo-anthracene to the tetraphenylnaphthalene-boric acid to the catalyst is 1:2 to 4:0.05 to 0.1.

More preferably, the bis-para-bromo-anthracene, tetraphenylnaphthalene-boronic acid and catalyst are added in a molar ratio of 1:3: 0.07.

Preferably, the temperature of the Suzuki reaction is 80-95 ℃, and the reaction time is 36-60 ℃.

More preferably, the temperature of the Suzuki reaction is 90 ℃ and the reaction time is 48 ℃.

Preferably, the extractant used for the extraction is saturated brine and dichloromethane.

Preferably, the purification is performed by column chromatography, wherein the stationary phase is silica gel powder and the eluent is petroleum ether/dichloromethane.

The invention also protects the application of the anthracene derivative as a luminescent material in an organic luminescent device.

Compared with the prior art, the invention has the beneficial effects that:

the invention creatively synthesizes the anthracene derivative. The anthracene derivative enables carrier injection and transmission to be more balanced by virtue of the excellent characteristics of anthracene materials and tetraphenylnaphthalene and balances charge transfer effect between an electron donor and an acceptor, so that deep blue emission of the solid film can be maintained while high fluorescence quantum efficiency of an aggregation state is realized, and organic light-emitting micromolecules with good carrier transmission capability and high fluorescence quantum yield in the aggregation state are synthesized. The preparation method of the anthracene derivative is simple and convenient, can be used for large-scale batch preparation, and is applied to industrial production. The anthracene derivative can be used as a luminescent material and widely applied to organic light-emitting devices, in particular to stable and efficient deep blue organic electroluminescent devices.

Drawings

FIG. 1 shows the molecular hydrogen spectrum of the anthracene derivative An-TNa1 prepared in example 1 measured by a superconducting NMR spectrometer.

FIG. 2 shows the molecular hydrogen spectrum of the anthracene derivative An-TNa2 prepared in example 2 measured by a superconducting NMR spectrometer.

FIG. 3 shows the absorption spectra of An-TNa1 and An-TNa2 in methylene chloride solution measured by Shimadzu UV-2700 spectrophotometer for visible and ultraviolet light.

FIG. 4 shows fluorescence emission spectra of An-TNa1 and An-TNa2 in dichloromethane measured at An excitation wavelength of 350nm for Edinburgh FLS 980.

FIG. 5 shows normalized absorption spectra of An-TNa1 and An-TNa2 in the thin film state, as measured by Shimadzu UV-2700 UV-visible spectrophotometer.

FIG. 6 is a normalized fluorescence emission spectrum of Edinburgh FL980 transient steady state fluorescence phosphorescence spectrometer under the state of An-TNa1 and An-TNa2 thin films at An excitation wavelength of 350 nm.

FIG. 7 shows the electroluminescence spectra of An-TNa1 and An-TNa2 as OLED light-emitting layer devices measured by Photo Research PR745 spectrum scanner.

FIG. 8 is a graph showing the relationship between the external quantum yield and the luminance of An-TNa1 and An-TNa2 as OLED light-emitting layer devices measured by a Photo Research PR745 spectrum scanner.

Detailed Description

The present invention will be further described with reference to the following embodiments.

The raw materials in the examples are all commercially available;

reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

Example 1

Example 1 provides an anthracene derivative prepared by the following method:

para-bromo-naphthalene anthracene (1.15g, 3mmol), tetraphenylnaphthalene boronic acid (2.51g, 4.5mmol) and tetrakistriphenylphosphine palladium (0.16g, 0.21mmol) were charged to a 100ml two-necked flask, which was evacuated under vacuum and replaced three times under dry nitrogen;

60mL of tetrahydrofuran and 8mL of saturated K were added₂CO₃Heating, refluxing and stirring the aqueous solution at 90 ℃ for reacting for 48 hours to obtain a mixed solution;

the mixed solution was extracted with saturated brine and dichloromethane, and distilled under reduced pressure to obtain a black solid, which was purified by column chromatography using silica gel powder as the stationary phase and petroleum ether/dichloromethane as the eluent, to give the anthracene derivative An-TNa1 in a total of 1.0g, 80% yield.

The reaction process is as follows:

example 2

Example 2 provides an anthracene derivative prepared by the following method:

bis-p-bromoanthracene (1.01g, 3mmol), tetraphenylnaphthalene boronic acid (5.02g, 9mmol) and tetrakistriphenylphosphine palladium (0.16g, 0.21mmol) were charged to a 100ml two-necked flask, which was evacuated under vacuum and replaced three times with dry nitrogen;

extracting the mixed solution by using saturated saline water and dichloromethane, and distilling under reduced pressure to obtain black solid; the anthracene derivative An-TNa2 was obtained by column chromatography with silica gel as the stationary phase and petroleum ether/dichloromethane as the eluent in a total of 1.69g, with a yield of 66.7%.

The reaction process is as follows:

example 3

Example 3 provides an anthracene derivative, which is prepared by a method different from that of example 1: the amount of tetraphenylnaphthalene boronic acid added was 3mmol, and the amount of tetratriphenylphosphine palladium added was 0.15 mmol.

Example 4

Example 4 provides an anthracene derivative, which is prepared by a method different from that of example 1: the amount of tetraphenylnaphthalene boronic acid added was 6mmol, and the amount of tetratriphenylphosphine palladium added was 0.3 mmol.

Example 5

Example 5 provides an anthracene derivative, which is prepared by a method different from that of example 2: the amount of tetraphenylnaphthalene boronic acid added was 6mmol, and the amount of tetratriphenylphosphine palladium added was 0.15 mmol.

Example 6

Example 6 provides an anthracene derivative, which is prepared by a method different from that of example 2: the amount of tetraphenylnaphthalene boronic acid added was 12mmol, and the amount of tetratriphenylphosphine palladium added was 0.3 mmol.

Application testing

The anthracene derivatives prepared in example 1 and example 2 were selected for application tests.

The test method is as follows:

and (3) detecting the structure of the compound: detecting by a superconducting nuclear magnetic resonance apparatus Bruker 400MHz to obtain a molecular hydrogen spectrum, wherein a solvent is deuterated DMSO;

absorption light intensity: detecting absorption spectra of the anthracene derivatives An-TNa1 and An-TNa2 in a dichloromethane solution and normalized absorption spectra in An-TNa1 and An-TNa2 film states by using An Shimadzu UV-2700 ultraviolet-visible spectrophotometer;

emission light intensity: detecting fluorescence emission spectra of anthracene derivatives An-TNa1 and An-TNa2 under dichloromethane and normalized fluorescence emission spectra under An-TNa1 and An-TNa2 thin film states at An excitation wavelength of 350nm by using Edinburgh FLS 980;

electroluminescent properties: anthracene derivatives An-TNa1 and An-TNa2 are respectively used as OLED light-emitting layer devices, and An electroluminescence spectrum is obtained by detecting with a Photoresearch PR745 spectrum scanner;

external quantum yield (EQE): anthracene derivatives An-TNa1 and An-TNa2 were used as OLED light-emitting layer devices, respectively, and their EQE and luminance relationship spectra were measured using a Photo Research PR745 spectral scanner.

The test results were as follows:

the molecular hydrogen spectrum of the anthracene derivative An-TNa1 is shown in FIG. 1, and the molecular hydrogen spectrum of the anthracene derivative An-TNa2 is shown in FIG. 2, and it can be seen that:

An-TNa1 has a characteristic wave number (ppm) of molecular hydrogen spectrum of¹H NMR(600MHz,Chloroform-d)8.06(dd,J＝8.3,5.6Hz,1H),8.03–7.98(m,1H),7.98–7.83(m,4H),7.79–7.73(m,2H),7.69(dd,J＝8.0,1.6Hz,2H),7.63–7.51(m,4H),7.40–7.34(m,2H),7.34–7.26(m,6H),7.25–7.22(m,2H),7.17(t,J＝1.7Hz,1H),7.09(t,J＝7.6Hz,2H),7.04–6.98(m,1H),6.96–6.80(m,10H)；

An-TNa2 has a characteristic wave number (ppm) of molecular hydrogen spectrum of¹H NMR(400MHz,DMSO-d6)7.76–7.65(m,2H),7.63–7.57(m,4H),7.57–7.47(m,3H),7.45–7.36(m,7H),7.35(s,2H),7.26(s,7H),7.23(s,2H),7.10(d,J＝7.2Hz,4H),7.01(dd,J＝12.6,7.7Hz,9H),6.92(dd,J＝15.6,7.2Hz,10H),6.86(d,J＝6.5Hz,4H)。

The wave peak energy corresponds to the hydrogen atoms of anthracene and tetraphenylnaphthalene one by one, and the quantity is reasonable, which shows that the tetraphenylnaphthalene substituted anthracene derivatives An-TNa1 and An-TNa2 prepared in examples 1 and 2 have single structures.

The luminescence properties of the anthracene derivatives An-TNa1 and An-TNa2 are shown in fig. 3 and 4, the arrows indicate the direction of the ordinate of the curve reading, and the absorption intensity and emission intensity are read by a normalization method. The maximum absorption peaks of the anthracene derivative are all located within 350-425 nm, and the anthracene derivative shows the triplet absorption of a typical anthracene derivative; the emission wavelengths were 424 and 447nm, respectively, indicating that the emission is in the deep blue region. The absolute fluorescence quantum yield of the organic electroluminescent material in the solution can reach nearly 100%, which shows that the organic electroluminescent material has extremely high fluorescence quantum yield in the solution and can be applied to high-efficiency deep blue organic electroluminescent devices.

The luminescence properties of the anthracene derivatives An-TNa1 and An-TNa2 in the state of aggregation are shown in fig. 5 and 6, and the arrows indicate the directions of ordinate of curve reading, reading absorption intensity and emission intensity. As can be seen from the figure, the maximum absorption peaks are all located within 350-425 nm, and the triple absorption of a typical anthracene derivative is shown; the emission wavelengths were 444 and 452nm, respectively, showing that it can also achieve deep blue emission in the aggregated state, and has a high absolute fluorescence quantum yield in the thin film, indicating that it can efficiently emit fluorescence also in the aggregated state.

Due to the deep blue emission and high fluorescence quantum yield, the anthracene derivatives An-TNa1 and An-TNa2 are respectively used as non-doped OLED devices of a light-emitting layer, and the device structures are HAT-CN (10nm)/TAPC (50nm)/TCTA (10nm)/EML (20nm)/TPBI (40nm)/LiF (1nm)/Al (100 nm).

The electroluminescence spectrum of the OLED device is shown in FIG. 7, the maximum emission wavelength of the undoped devices of An-TNa1 and An-TNa2 is 445nm, standard deep blue emission is achieved, the half-peak width is only 68nm, and the high color purity is shown. The CIE color coordinates are (0.15, 0.09) and (0.15, 0.11), which all reach the deep blue emission of the OLED device with the international standard (x + y < 0.30). Indicating that undoped OLED devices using An-TNa1 or An-TNa2 as the light-emitting layer have very high color purity.

The external quantum yield (EQE) and the luminance relationship of the OLED device are shown in fig. 8, and the devices using An-TNa1 and An-TNa2 as the light emitting layer respectively obtain the maximum EQE of 5.05% and 4.27%, which indicates that the tetraphenylnaphthalene-substituted anthracene derivatives prepared in examples 1-2 have good photoelectric properties and carrier transport ability in the OLED device. OLED devices using An-TNa1 as the light-emitting layer can achieve a maximum of over 4000 nits (cd/m) driven at voltages below 8 volts ²) The luminance of (2) shows excellent luminance performance under the condition that the device activation voltage of the light emitting layer is low.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. An anthracene derivative, wherein the structure of the anthracene derivative is shown as formula (I):

wherein R is

2. The process for producing an anthracene derivative according to claim 1, comprising the steps of:

mixing para-bromo-naphthalene anthracene or bis-para-bromo-anthracene, tetraphenylnaphthalene boric acid with a catalyst, reacting in the presence of strong alkali under the protection of inert gas to obtain mixed liquor containing anthracene derivatives, and extracting and purifying to obtain the anthracene derivatives.

3. The method of claim 2, wherein the catalyst is a palladium catalyst.

4. The method according to claim 2, wherein the catalyst is palladium tetrakistriphenylphosphine.

5. The method according to claim 2, wherein the strong base is potassium carbonate or sodium carbonate.

6. The production method according to claim 2, wherein the para-bromo-naphthalene anthracene, the tetraphenylnaphthalene-boric acid and the catalyst are added in a molar ratio of 1:1 to 2:0.05 to 0.1.

7. The method according to claim 2, wherein the bis-p-bromo-anthracene, the tetraphenylnaphthalene-boric acid and the catalyst are added in a molar ratio of 1:2 to 4:0.05 to 0.1.

8. The method according to claim 2, wherein the Suzuki reaction temperature is 80 to 95 ℃ and the reaction time is 36 to 60 ℃.

9. The method according to claim 2, wherein the Suzuki reaction temperature is 90 ℃ and the reaction time is 48 ℃.

10. Use of the anthracene derivative according to claim 1 as a light-emitting material in an organic light-emitting device.