阅读说明：本技术 一种侧基支化蓝光聚合物材料及制备方法和发光器件应用 (Side group branched blue-light polymer material, preparation method and application of luminescent device ) 是由 林进义 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种侧基支化蓝光聚合物材料及制备方法和发光器件应用,该聚合物材料的结构单元的4位烷氧链为具有支化结构的取代基团。该聚合物材料的单体是通过拜耳-维立格和格氏反应合成。该9,9-二芳基芴类聚合物材料由其单体通过Yamamoto聚合反应得到。该聚合物材料可作为发光层应用于有机发光二极管器件。与直链侧基取代聚二芳基芴相比,本发明的9,9-二芳基芴类聚合物材料采用支化位阻侧链,不仅能有效抑制整个分子链的平面构象转变,提高形态稳定性,而且能提高材料的溶解度,提高成膜的能力,具有高效稳定的蓝光发射性能。(The invention discloses a lateral group branched blue light polymer material, a preparation method and application of a luminescent device, wherein a 4-bit alkoxy chain of a structural unit of the polymer material is a substituent group with a branched structure. The monomers of the polymer material are synthesized by Bayer-Virgo and Grignard reactions. The 9, 9-diaryl fluorene polymer material is prepared by Yamamoto polymerization reaction of monomers thereof. The polymer material can be used as a light-emitting layer to be applied to an organic light-emitting diode device. Compared with the linear side group substituted polydiarylfluorene, the 9, 9-diarylfluorene polymer material adopts the branched steric hindrance side chain, not only can effectively inhibit the planar conformation transformation of the whole molecular chain and improve the form stability, but also can improve the solubility of the material and the film forming capability, and has efficient and stable blue light emission performance.)

1. A lateral group branched blue light polymer material is characterized in that the polymer material is a 9, 9-diaryl fluorene polymer material of which the 4-position of a structural unit contains an alkyl lateral chain with a branched steric hindrance structure, the 4-position alkoxy chain of the structural unit is a substituent group with a branched structure, and the polyfluorene polymer material has the following general structure:

wherein R is an alkyl chain with a branched steric hindrance structure and 8 carbon atoms.

2. The pendant branched blue-emitting polymeric material of claim 1, wherein: r is one of the following structures:

3. a method for preparing the monomer of the side-group branched blue-emitting polymer material according to claim 1 or 2, wherein: the monomers of the polymer material are synthesized by Bayer-Virgo and Grignard reactions.

4. The method for preparing the side-group branched blue-light emitting polymer material monomer according to claim 3, wherein: when the 4-position of the structural unit of the 9, 9-diaryl fluorene polymer material is an isooctyl structure, the reaction path of the monomer of the polymer material is as follows:

step 1, preparing 2, 7-dibromolactone from 2, 7-dibromo-9-fluorenone through a Bayer-Vickers rearrangement reaction, specifically, reacting 2, 7-dibromofluorenone for 72 hours at room temperature under the conditions of trifluoroacetic acid and sodium percarbonate;

step 2, preparing 2, 7-dibromodiol through Grignard reaction, specifically reacting 2, 7-dibromolactone prepared in the step 1 with 4-6 times of equivalent of a Grignard reagent of bromobenzene, wherein a solvent is toluene, and reacting for 24 hours at 85 ℃ under the protection of nitrogen;

step 3, performing alkyl substitution reaction on the 4 th alcohol group, specifically reacting the 2, 7-dibromodiol prepared in the step 2 with 2 times of equivalent of bromoisooctane for 24 hours at room temperature under an alkaline condition by using acetone as a solvent;

and 4, preparing a polymer monomer by Friedel-crafts reaction, and specifically, dissolving the product obtained in the step 3 in anhydrous dichloromethane, and reacting for 2 hours under the catalysis of boron trifluoride-diethyl ether.

5. A method of preparing a pendant branched blue-emitting polymeric material according to claim 1 or 2, wherein: the 9, 9-diaryl fluorene polymer material is prepared by Yamamoto polymerization reaction of monomers thereof.

6. Use of a pendant branched blue-emitting polymeric material according to claim 1 or 2, wherein: the polymer material can be used as a light-emitting layer to be applied to an organic light-emitting diode device.

Technical Field

The invention belongs to the technical field of organic photoelectric materials, and particularly relates to a side group branched blue-light polymer material, a preparation method and application of a light-emitting device.

Background

As a wide band gap light emitting polymer having the most practical application potential, a polyfluorene semiconductor is widely applied to light emitting optoelectronic devices due to its advantages of deep blue light, high fluorescence efficiency, easy modification and the like. Similar to other luminescent polymers, polyfluorene semiconductors with traditional structures also present complex chain conformation behaviors and multiphase transition characteristics in the processing and post-treatment processes, micro-nano regions in films are easily induced to present different condensed state structures, so that the molecular chains are easy to generate photophysical processes such as exciton association emission, singlet annihilation or excited state electron hybridization, and the like, thereby leading the solid films to generate self-absorption or energy transfer behaviors, generating unstable photoelectric physical processes, and reducing the luminescent performance and stability of devices. Therefore, although a series of important advances have been made in the manufacture of materials, the application of optoelectronic devices and the development of new functions of polyfluorene semiconductors, due to the complex and variable condensed state structure of polyfluorene semiconductors, the conventional polyfluorene semiconductors cannot achieve the expected effects in material performance, large-area manufacture and device application, and many key problems, such as complex semiconductor physical process, variable film condensed state structure, poor light-emitting stability, poor device stability and poor manufacturing repeatability, are still needed to be solved. In particular, the problem of the stability of the blue light of the polyfluorene semiconductor needs to be solved urgently. Blue light materials generally have higher energy absorption and high energy band emission, so that the blue light materials are easily influenced by external environment to reduce the stability of materials, morphology and spectrum, and the luminescence of the materials is induced to be transferred from the high energy band emission to the low energy band. At present, a large number of researches show that the generation of low energy bands (500-600 nm) induced by molecular chain aggregation and the stability of blue light are closely related to the aggregation action form and the arrangement structure in/among molecular chains. It is well known that the blue light instability of polyfluorene is an important bottleneck limiting the development of its applications. Currently, the main causes of polyfluorene green band emission can be divided into two mechanisms of action: fluorenones and aggregation induction mechanisms. The existing solution mainly introduces large condensed ring or cyclic group through steric hindrance functionalization of a main chain, inhibits aggregation among molecular main chains, and improves the form and spectral stability of the film. Due to the introduction of a ring or fused ring structure, a barrier layer is introduced into a conjugated main chain, so that Stoke displacement is reduced, aggregation among the main chains is inhibited, and exciton behavior of a monomolecular mechanism is realized. In fact, in order to improve the solubility of the polymer blue light material, the introduction of a straight chain substituent generally induces a weak action on a molecular chain, so that a condensed state structure of a thin film is difficult to control, and the light emitting stability and the light emitting efficiency of the material are reduced. Therefore, how to explore an efficient and simple molecular design idea and improve the light-emitting stability of the polyfluorene semiconductor has important significance for improving, enriching and expanding the performance of the polyfluorene semiconductor and the application of the polyfluorene semiconductor in light-emitting optoelectronic devices.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a lateral group branched blue light polymer material, a preparation method and an application of a light-emitting device.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

a lateral group branched blue light polymer material is a 9, 9-diaryl fluorene polymer material with an alkyl lateral chain with a branched steric hindrance structure at the 4-position of a structural unit, wherein an alkoxy chain at the 4-position of the structural unit is a substituent group with a branched structure, and the polyfluorene polymer material has the following general structure:

wherein R is an alkyl chain with a branched steric hindrance structure and 8 carbon atoms.

Preferably, R is one of the following structures:

the invention also provides a preparation method of the polymer material monomer, which comprises the following steps: the monomers of the polymer material are synthesized by Bayer-Virgo and Grignard reactions.

When the 4-position of the structural unit of the 9, 9-diaryl fluorene polymer material is an isooctyl structure, the reaction path of the monomer of the polymer material is as follows:

step 1, preparing 2, 7-dibromolactone from 2, 7-dibromo-9-fluorenone through a Bayer-Vickers rearrangement reaction, specifically, reacting 2, 7-dibromofluorenone for 72 hours at room temperature under the conditions of trifluoroacetic acid and sodium percarbonate;

step 2, preparing 2, 7-dibromodiol through Grignard reaction, specifically reacting 2, 7-dibromolactone prepared in the step 1 with 4-6 times of equivalent of a Grignard reagent of bromobenzene, wherein a solvent is toluene, and reacting for 24 hours at 85 ℃ under the protection of nitrogen;

step 3, performing alkyl substitution reaction on the 4 th alcohol group, specifically reacting the 2, 7-dibromodiol prepared in the step 2 with 2 times of equivalent of bromoisooctane for 24 hours at room temperature under an alkaline condition by using acetone as a solvent;

and 4, preparing a polymer monomer by Friedel-crafts reaction, and specifically, dissolving the product obtained in the step 3 in anhydrous dichloromethane, and reacting for 2 hours under the catalysis of boron trifluoride-diethyl ether.

The invention also provides a preparation method of the polymer material, which comprises the following steps: the 9, 9-diaryl fluorene polymer material is obtained by Yamamoto polymerization reaction of monomers, and the specific process of the polymerization reaction is as follows: taking the same amount of bipyridine and nickel catalyst Ni (COD)₂In full of N₂The two-neck flask is then activated in DMF solution at 75 ℃ for 20min, then monomer solution dissolved by toluene is added, reflux is carried out for 3 days at 85 ℃, then dried bromobenzene sealing end is used for 0.1ml, THF and hydrazine hydrate are finally used for extraction and extinction, silicon-based metal remover is used for removing residual nickel catalyst in the post-treatment process, then absolute methanol is used for sedimentation by rotary evaporation, acetone is used for extraction for 3 days, and finally vacuum drying is carried out to obtain powdery product.

The side group branched blue light polymer material can be used as a light emitting layer to be applied to an organic light emitting diode device, and the structure of the organic light emitting diode is as follows: ITO/PEDOT PSS/EML/TPBi/LiF/Al.

The invention has the beneficial effects that: the 4-alkoxy chain of the structural unit of the 9, 9-diaryl fluorene polymer material is a substituent group with a branched structure, and specifically, the substituent group can be an alkyl chain with different branching degrees and 8 carbon atoms; compared with the linear side group substituted polydiarylfluorene, the polymer material disclosed by the invention can effectively inhibit planar conformation transformation of a molecular chain, improve form stability and oxidation resistance, improve solubility and improve film forming capability by adopting a branched steric hindrance side chain, so that PLEDs and organic lasers can obtain stable deep blue emission, and can be used as a high-efficiency stable blue light main body material to be applied to the display fields of polymer organic light-emitting diodes and the like.

Drawings

FIG. 1 is an absorption and emission spectrum of a 9, 9-diarylfluorene-based polymer material of example 1 of the present invention measured when dissolved in toluene.

Fig. 2 is an electroluminescence spectrum of the 9, 9-diarylfluorene polymer material as a material of a light emitting layer provided in embodiment 1 of the present invention.

Detailed Description

The following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.

A lateral group branched blue light polymer material is a 9, 9-diaryl fluorene polymer material with an alkyl lateral chain with a branched steric hindrance structure at the 4-position of a structural unit, wherein an alkoxy chain at the 4-position of the structural unit is a substituent group with a branched structure, and the polyfluorene polymer material has the following general structure:

wherein R is an alkyl chain with a branched steric hindrance structure and 8 carbon atoms.

In the above formula, R is one of the following structures:

the invention also provides a preparation method of the side group branched blue-light polymer material monomer, which comprises the following steps: the monomers of the polymer material are synthesized by Bayer-Virgo and Grignard reactions.