阅读说明：本技术 一种超支化磷光聚合物及其制备方法 (Hyperbranched phosphorescent polymer and preparation method thereof ) 是由 徐海琴 于 2020-06-15 设计创作，主要内容包括：本发明属发光材料技术领域,具体涉及一种超支化磷光聚合物及其制备方法。本发明提供了一种超支化磷光聚合物,其结构如式(I)所示。本发明还提供了一种超支化磷光聚合物的制备方法,包括以下步骤：步骤1：将4-碘苯酚和(4-((10-溴十烷基)氧基)环己基)苯进行亲核取代反应,得到I-Y；步骤2：将N-(3-氨基苯基)-2,7-二溴咔唑,所述I-Y和t-BuONa进行亲电取代应得到式(II)所示化合物；步骤3：将2,2’-(9,9-二丁基-9H-芴-2,7-二基)双(4,4,5,5-四甲基-1,3,2-二氧杂硼烷),式(II)所示化合物,2,5-双(4-溴苯基)-1,3,4-恶二唑和式(III)所示化合物通过Suzuki偶连反应得到式(I)所示聚合物。本发明解决了现有的磷光发射材料光学带隙较宽,且发光效率不理想的技术问题。(The invention belongs to the technical field of luminescent materials, and particularly relates to a hyperbranched phosphorescent polymer and a preparation method thereof. The invention provides a hyperbranched phosphorescent polymer, which has a structure shown in a formula (I). The invention also provides a preparation method of the hyperbranched phosphorescent polymer, which comprises the following steps: step 1: carrying out nucleophilic substitution reaction on 4-iodophenol and (4- ((10-bromodecyl) oxy) cyclohexyl) benzene to obtain I-Y; step 2: carrying out electrophilic substitution on N- (3-aminophenyl) -2, 7-dibromocarbazole, the I-Y and t-BuONa to obtain a compound shown in a formula (II); and step 3: 2,2' - (9, 9-dibutyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane), a compound represented by the formula (II), 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole, and a compound represented by the formula (III) were subjected to Suzuki coupling reaction to obtain a polymer represented by the formula (I). The invention solves the technical problems that the optical band gap of the existing phosphorescent light-emitting material is wider and the luminous efficiency is not ideal.)

1. A hyperbranched phosphorescent polymer is characterized in that the structure is shown as formula (I):

wherein Y is

Wherein x is 100-.

2. A preparation method of a hyperbranched phosphorescent polymer is characterized by comprising the following steps:

step 1: carrying out nucleophilic substitution reaction on 4-iodophenol and (4- ((10-bromodecyl) oxy) cyclohexyl) benzene to obtain I-Y;

step 2: electrophilic substitution of N- (3-aminophenyl) -2, 7-dibromocarbazole, I-Y and t-BuONa is carried out to obtain the compound shown in the formula (II)

And step 3: 2,2' - (9, 9-dibutyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane), the compound shown in the formula (II), 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole and the compound shown in the formula (III) are subjected to Suzuki coupling reaction to obtain a polymer shown in the formula (I),

3. the method for preparing hyperbranched phosphorescent polymer according to claim 2, wherein the amount of the substance of 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole in step 3 is 0.05mmol to 0.2 mmol.

4. The method for preparing hyperbranched phosphorescent polymer according to claim 2, wherein the temperature of the nucleophilic substitution reaction in the step 1 is 100 ℃.

5. The method of claim 2, wherein the electrophilic substitution in step 2 is at a temperature of 120 ℃.

6. The method for preparing hyperbranched phosphorescent polymer according to claim 2, wherein the temperature of the Suzuki coupling reaction in step 3 is 80 ℃.

Technical Field

The invention belongs to the technical field of luminescent materials, and particularly relates to a hyperbranched phosphorescent polymer and a preparation method thereof.

Background

In general, an organic light emitting device includes: an anode on the substrate; a hole transport layer, a light emitting layer, an electron transport layer, and the like as organic layers on the anode. Compounds used to form an emission layer of an organic light emitting device are classified into fluorescent compounds using singlet excitons and phosphorescent compounds using triplet excitons according to an emission mechanism. However, when the fluorescent compound is used to form a light emitting layer in an organic light emitting device, it has the following disadvantages: triplet excitons generated in the host are wasted, and thus, when a phosphorescent compound has been gradually used to form a light emitting layer, since it simultaneously utilizes singlet excitons and triplet excitons, the internal quantum efficiency is much higher than that of a fluorescent light emitting layer. Examples of phosphorescent compounds may include organic complexes complexed with heavy metals such as Ir, Pt, Rh and Pd. When a heavy metal is introduced into an organic molecule, triplet excitons and singlet excitons are mixed by spin-orbit coupling generated by the heavy atom effect. JP-A-2004-531850 discloses ｃA phosphorescent polymer material having ｃA phosphorescent iridium complex as ｃA side chain of the polymer. Wherein the iridium complex is caused to emit light by an electronic transition between the metal of the polymer backbone and the phenylpyridine ligand or within the phenylpyridine ligand. However, when the phosphorescent polymer material is applied to a double-layer electroluminescent device, concentration quenching effect is easily caused by the aggregation of the complex, and the optical band gap is widened, so that the electroluminescent efficiency of the phosphorescent emitting material is not ideal. Therefore, the conventional phosphorescent emitting material has a wider optical band gap and unsatisfactory electroluminescent efficiency, which is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a hyperbranched phosphorescent polymer.

The invention also aims to provide a preparation method of the hyperbranched phosphorescent polymer.

The above purpose of the invention is realized by the following technical scheme:

the invention provides a hyperbranched phosphorescent polymer, which has a structure shown in a formula (I):

wherein Y is

Wherein x is 100-.

The invention also provides a preparation method of the hyperbranched phosphorescent polymer, which comprises the following steps:

step 1: carrying out nucleophilic substitution reaction on 4-iodophenol and (4- ((10-bromodecyl) oxy) cyclohexyl) benzene to obtain I-Y;

step 2: electrophilic substitution of N- (3-aminophenyl) -2, 7-dibromocarbazole, I-Y and t-BuONa is carried out to obtain the compound shown in the formula (II)

And step 3: 2,2' - (9, 9-dibutyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane), the compound shown in the formula (II), 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole and the compound shown in the formula (III) are subjected to Suzuki coupling reaction to obtain a polymer shown in the formula (I),

preferably, the amount of the substance of 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole in step 3 is from 0.05mmol to 0.2 mmol.

Preferably, the temperature of the nucleophilic substitution reaction in step 1 is 100 ℃.

Preferably, the temperature of the electrophilic substitution reaction in step 2 is 120 ℃.

Preferably, the temperature of the Suzuki coupling reaction in step 3 is 80 ℃.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the hyperbranched phosphorescent polymer prepared by the invention is prepared according to a calculation formula of an optical band gap of the polymer: the Eg is 1240/max, and the minimum can be 2.98eV, so that the increase of 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole can reduce the optical band gap of the polymer, and the electroluminescent efficiency of the polymer is obviously improved. The hyperbranched phosphorescent polymer prepared by the embodiment of the invention increases the luminous efficiency, current density and brightness of the device along with the increase of the content of 2, 5-bis (4-bromophenyl) -1,3, 4-oxadiazole, reduces the turn-on voltage and effectively improves the electroluminescent efficiency of the device.

Drawings

FIG. 1 is a synthesis scheme of a hyperbranched phosphorescent polymer in an embodiment of the invention;

FIG. 2 is a graph showing the UV-VIS absorption spectrum of a hyperbranched phosphorescent polymer prepared in an example of the present invention;

FIG. 3 is a current density-external quantum efficiency curve of hyperbranched phosphorescent polymers prepared in the examples of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.