TWI594993B - An organic compound and the method for preparing the same and its application - Google Patents

Description

Organic compound and synthesis method and application thereof

The present invention relates to an organic compound, and more particularly to an organic compound which can be used for a broad band, high glass transition temperature (Tg) organic light-emitting diode light-emitting layer host material, a method for synthesizing the same, and the organic light-emitting diode An element of the luminescent layer body material.

Organic Light-emitting Diode (OLED) has all-solid-state, self-luminous, high-brightness, high-resolution, ultra-wide viewing angle (above 170 degrees), fast response, and low driving voltage (3-10V) ), low power consumption, wide operating temperature range, flexible substrate, small size, thin thickness, and light weight. In recent years, in the field of flat panel displays, attention has been paid to lighting systems, communication systems, vehicle displays, and portable devices. Electronic equipment, high-definition displays and even military applications are widely used. The OLED is generally composed of two side electrodes and an organic thin film (light emitting layer) having a semiconductor property sandwiched between the electrodes, wherein at least one of the electrodes is a transparent electrode. Driven by the external voltage, the electrons injected by the cathode and the holes injected by the anode interact in the luminescent layer to form excited excitons. The energy gradient generated by the radiation transition from the excited state back to the ground state is finally photon. Form release.

However, the organic electroluminescent material is generally a singlet fluorescent dye or a triplet phosphorescent dye, but the material has a strong concentration quenching effect, which reduces the luminous efficiency of the emitting layer. Therefore, at present, the luminescent layer in the organic light-emitting diode device almost uses a host-guest illuminant system structure, that is, a guest illuminant material such as a fluorescent dye or a phosphorescent dye is doped to a host having good carrier transport capability. In materials, this can greatly reduce the quenching caused by excessive exciton concentration, especially the triplet-triplet annihilation of phosphorescent materials.

Such as: Forrest and Thompson et al. 4,4'-N, N'-dicarbazolyl-3,5-substituted benzene as the main material, blue iridium complexes as doping materials for organic electroluminescent devices, the largest The power can reach 8.9ml/W. Chinese patent application CN102031104A discloses a bipolar phosphorescent host material of an anthracene derivative of tetraphenylphosphonium and carbazole, and is doped with Ir(ppy)3. Chinese patent application CN101368096A discloses a ruthenium complex doped in a main illuminant and a luminescent layer obtained by doping it with a main luminescent material. The structure of a compound generally used in an organic layer such as a main luminescent material or a guest luminescent material is also disclosed in Japanese Patent Application No. JP2002-305083A.

In general, the energy gap of the host material should be larger than the energy gap of the guest illuminant material, otherwise the energy is easily transferred from the guest illuminant to the host material to reduce the efficiency of the device, in addition to the main material - especially small Molecular host materials also have high requirements on crystallization properties and glass transition temperatures.

The invention provides an organic compound, and the problem to be solved is that the small molecule host material in the OLED is easy to crystallize and the Tg is low.

The first aspect of the present application provides an organic compound having the molecular structure represented by the structural formula (I) or (II): (I) (II)

Wherein, Ar is a cyclic group of C4-C7 or a cyclic group of C4-C7 containing a hetero atom.

Among them, Ar is preferably any one of a benzene ring and a pyridine, and more preferably a benzene ring.

Wherein the organic compound has the molecular structure represented by the structural formula (I-1) or (II-1):

In the above aspect of the present invention, the number of the R ₁ and R ₂ groups may be independently one or more, and may be substituted at any position of the naphthalene ring.

Wherein R ₁ and R ₂ may be the same or different.

Wherein the R ₁ and R ₂ groups may be independently selected from any of H, C1-C5 alkyl groups.

In the above aspect of the invention, R may be any one selected from the group consisting of:

Among them, Ar ₁ , Ar ₂ , Ar ₃ , and Ar ₄ may be the same or different.

Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl.

In a preferred embodiment of the invention, the organic compound is a helical biphthyl derivative.

In the above aspect of the invention, the C1-C5 alkyl group may be any one or more selected from the group consisting of methyl, ethyl, propyl, isopropyl, t-butyl, n-butyl and n-pentyl.

In the above aspect of the invention, the C6-C20 aromatic group may be any one or more selected from the group consisting of a phenyl group, a biphenyl group, a naphthyl group and a fluorenyl group.

In a preferred embodiment of the invention, the R group is selected from any of the following groups:

Among them, the above organic compound is a helical biphenyl derivative.

A second aspect of the present invention provides a method for synthesizing the above organic compound, comprising: an R or S configuration of the formula (III), 1,1'-bi-2-naphthol and the formula (IV) The compound is reacted at 45 to 70 ° C to obtain an intermediate (V); wherein, X ₁ and X ₂ are each independently selected from a halogen atom; and the halogen atom X1 in the intermediate (V) is substituted with an R group to give a structural formula (I) Or an organic compound as shown in (II).

Wherein the number of the R ₁ and R ₂ groups may be independently one or more, and may be substituted at any position of the naphthalene ring.

Wherein R ₁ and R ₂ may be the same or different.

Wherein the R ₁ and R ₂ groups may be independently selected from any of H, C1-C5 alkyl groups.

Wherein X ₁ and X ₂ may be the same or different.

Wherein X ₁ and X ₂ are each independently preferably Cl or Br.

Wherein, Ar is a cyclic group of C4-C7 or a cyclic group of C4-C7 containing a hetero atom.

Among them, Ar is preferably any one of a benzene ring and a pyridine, and more preferably a benzene ring.

Wherein the compound of the formula (IV) is preferably a 3,5-di(halomethyl)-halobenzene represented by the formula (VI):

Wherein R may be any one selected from the group consisting of: or

Among them, Ar ₁ , Ar ₂ , Ar ₃ , and Ar ₄ may be the same or different.

Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl.

In the above, in the above aspect of the present invention, the C1-C5 alkyl group may be any one or a few of a methyl group, an ethyl group, a propyl group, an isopropyl group, a t-butyl group, a n-butyl group, and a n-pentyl group. Kind.

In the above, in the above aspect of the invention, the C6-C20 aromatic group may be any one or more selected from the group consisting of a phenyl group, a biphenyl group, a naphthyl group and a fluorenyl group.

In a preferred embodiment of the invention, the R group is selected from any of the following groups:

In the synthesis method of the present invention, the reaction between 1,1'-bi-2-naphthol represented by the formula (III) and the compound of the formula (IV) is preferably carried out in the presence of a catalyst.

Wherein, the catalyst may be any one or more selected from the group consisting of K ₂ CO ₃ , Na ₂ CO ₃ , NaOH, KOH, Mg/I ₂ , and more preferably K ₂ CO ₃ .

In the synthesis method of the present invention, the reaction between the 1,1'-bi-2-naphthol represented by the formula (III) and the compound of the formula (IV), the reaction temperature is preferably 50-60 ° C. More preferably, it is carried out under reflux conditions in an acetone solvent.

In the synthesis method of the present invention, the reaction in which X ₁ in the intermediate (V) is substituted with an R group is preferably carried out by intermediate (V) and RH by a Buchwald coupling reaction (Buckwald Coupling).

In the synthesis method of the present invention, the reaction of X ₁ in the intermediate (V) by the substitution of the R group, the reaction temperature is preferably 80-160 ° C, more preferably 90-150 ° C, more preferably selected from two The reaction is refluxed in any one or several solvents of hexacyclohexane, toluene and butyl ether.

In the Buchwald coupling reaction, preferably in the presence of a base, the base may be any one selected from the group consisting of sodium t-butoxide, Cs ₂ CO ₃ , K ₂ CO ₃ , K ₃ PO ₄ or Several.

A third aspect of the present invention provides an organic light-emitting device including at least one organic light-emitting diode including an anode, a cathode, and a light-emitting layer between the anode and the cathode, the light-emitting layer At least one organic compound having a molecular structure represented by the formula (I) or (II) is included:

Wherein, Ar is a cyclic group of C4-C7 or a cyclic group of C4-C7 containing a hetero atom.

Among them, Ar is preferably any one of a benzene ring and a pyridine, and more preferably a benzene ring.

Wherein the organic compound is a helical biphenyl derivative having a molecular structure represented by the structural formula (I-1) or (II-1):

In the above aspect of the present invention, the number of the R ₁ and R ₂ groups may be independently one or more, and may be substituted at any position of the naphthalene ring.

Wherein R ₁ and R ₂ may be the same or different.

Wherein the R ₁ and R ₂ groups may be independently selected from any of H, C1-C5 alkyl groups.

In the above aspect of the invention, R may be any one selected from the group consisting of:

Among them, Ar ₁ , Ar ₂ , Ar ₃ , and Ar ₄ may be the same or different.

Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl.

In the above aspect of the invention, the C1-C5 alkyl group may be any one or more selected from the group consisting of methyl, ethyl, propyl, isopropyl, t-butyl, n-butyl and n-pentyl.

In the above aspect of the invention, the C6-C20 aromatic group may be any one or more selected from the group consisting of a phenyl group, a biphenyl group, a naphthyl group and a fluorenyl group.

In a preferred embodiment of the invention, the R group is selected from any of the following groups:

Wherein, the luminescent layer further comprises a doped fluorescent dye or a phosphorescent dye.

The organic light emitting device of the present invention may be any one or a few of a cold light source, a display, or a mobile phone, a computer, an ATM machine, a POS machine, a game machine, a photocopying machine, a digital camera, a DVD, and a meter including the display. Kind.

The present invention provides an organic compound which is a helical biphenyl derivative having a certain dihedral angle between the two naphthalene rings rather than being fully conjugated. Molecules of this type have two advantages due to incomplete conjugation between the benzene ring and the benzene ring: 1) HOMO (highest occupied molecular orbital) and LUMO (lowest empty molecular orbital) have large energy level differences, which are difficult The energy revolving is generated; 2) the non-coplanarity of the molecules makes it difficult for the accumulation to occur and the concentration quenching effect occurs.

The glass transition temperature of the host material has a great influence on the stability of the device. The organic compound provided by the present invention can increase the glass transition temperature with a relatively large molecular size, and the inter-molecular space effect can also enhance.

The organic compound provided by the invention serves as a host material of the OLED light-emitting layer, and solves the defects that the small-molecule host material is easy to crystallize and the glass transition temperature of some broad-band main body materials is low. The invention adopts a series of helix naphthalene structures as the host material, and the two naphthalene rings have a certain dihedral angle instead of being completely conjugated, and can also replace the intermediate connecting benzene ring, for example, using a pyridine ring instead of the intermediate benzene. The ring is used to enhance the electron transport performance of the material. It can be seen from the experimental data that the organic compound obtained by the invention has the advantages of high glass transition temperature, energy bandwidth, difficulty in crystallization, and small concentration quenching effect.

It should be noted that the embodiments in the present invention and the features in the embodiments may be combined with each other without conflict.

The invention is further illustrated by the following figures and specific examples, but is not to be construed as limiting.

<Example 1>

step 1:

R or S configuration of 1,1'-bi-2-naphthol (28.6 g, 0.1 mol, 1.0 eq), 3,5-diodor methyl odor benzene (40.78 g, 0.12 mol, 1.2 eq) and K ₂ CO ₃ (41.4 g, 0.3 mol, 3.0 eq) was placed in a 3 L round bottom flask, and 1 L of anhydrous acetone was added and stirred under reflux for 24 hours. Subsequently, it was cooled to room temperature, concentrated in a vacuum using a rotary evaporator to remove an organic solvent, and a crude product was obtained, and the obtained crude product was subjected to column chromatography purification with ethyl acetate/petroleum ether (1:2 by volume) as a mobile phase. After drying under vacuum at 50 ° C, 2,2'-(1",3"-dibenzyloxy-5"-bromobenzene)-1,1'-binaphthyl (42 g, 0.09 mol, Yield 90%), the reaction equation is as follows: MS: m/z = 467.1 (M + ⁺ ); 1H NMR (400M, d6-DMSO): 7.64 (d, 2H), 7.60 (d, 2H), 7.56 (d, 2H), 7.32 (dd, 2H), 7.29 (s, 2H), 7.21 (dd, 2H), 7.10 (d, 2H), 7.06 (s, 1H), 5.30 (s, 4H). Anal. Calcd for C28H19BrO2: C, 71.96; H, 4.1; 6.85.Found: C, 71.93; H, 4.08; N, 6.86.

Step 2:

R or S configuration 2,2'-(1",3"-dibenzyloxy-5"-bromobenzene)-1,1'-binaphthyl (23.3 g, 0.05 mol, 1.0 eq), diphenyl Amine structure monomer (0.06 mol, 1.2 eq) and Cs ₂ CO ₃ (48.75 g, 0.15 mol, 3.0 eq), Pd(OAc) ₂ (0.336 g, 1.5 mmol, 0.03 eq), 2-dicyclohexylphosphine -2',6'-diisopropoxy-1,1'-biphenyl (Ru-Phos, 1.4 g, 3 mmol, 0.06 eq) was charged to a 1 L round bottom flask and 500 ml of anhydrous dioxane was added. Stirring under nitrogen for 24 hours, then cooling to room temperature, vacuum concentration using a rotary evaporator to remove the organic solvent and the crude product was obtained with ethyl acetate/petroleum ether (1:1 by volume) as mobile phase. The obtained crude product was purified by column chromatography, and dried under vacuum at 50 ° C to obtain an R or S configuration of 2,2'-(1",3"-dibenzyloxy-5"-substituted benzene)-1,1'. - binaphthyl (yield: 70%), the reaction equation is as follows: MS: m/z = 556.2 (M+H ⁺ ); 1H NMR (400M, d6-DMSO): 8.48 (dd, 2H), 8.05 (dd, 2H), 7.77 (td, 2H), 7.55 (dd, 2H) , 7.44 (dt, 2H), 7.20 (dd, 4H), 7.11 (d, 2H), 6.81 (tt, 2H), 6.72 (dt, 1H), 6.63 (d, 4H), 6.61 (t, 2H), 5.30(s,4H).Anal.Calcd for C40H29NO2: C, 86.46; H, 5.26; N, 2.52. Found: C, 86.43; H, 5.29; N, 2.53.

After detection, the compound of the present example has an excitation wavelength of 320 nm; an emission wavelength of 467 nm; and a glass transition temperature of Tg: 139 °C.

<Example 2>

Step 1: Synthesis of 2,2'-(1",3"-dibenzyloxy-5"-bromobenzene)-1,1'-binaphthyl

Synthesized as described in Example 1.

Step 2: Synthesis of 2,2'-(1",3"-dibenzyloxy-5"-bromobenzene)-1,1'-binaphthyl

R or S configuration 2,2'-(1",3"-dibenzyloxy-5"-bromobenzene)-1,1'-binaphthyl (0.05 mol, 1.0 eq), carbazole monomer (0.05 Mol, 1.0 eq) and Cs ₂ CO ₃ (0.15 mol, 3.0 eq), Pd(OAc) ₂ (1.5 mmol, 0.03 eq), 2-dicyclohexylphosphino-2',6'-diisopropoxy- 1,1'-biphenyl (Ru-Phos, 3 mmol, 0.06 eq) was placed in a 1 L round bottom flask, 500 ml of anhydrous toluene was added, and the mixture was stirred under reflux for 24 hours under nitrogen. Then cooled to room temperature using a rotary evaporator The organic solvent was removed by vacuum concentration to obtain a crude product, which was purified by column chromatography, and dried under vacuum at 50 ° C to obtain an R or S configuration of 2,2'-(1",3"-dibenzyloxy-5"- Substituting phenyl)-1,1'-binaphthyl, the reaction equation is as follows:

After detection, the compound of the present example has an excitation wavelength of 320 nm; an emission wavelength of 467 nm; and a glass transition temperature of Tg: 139 °C.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the embodiments and the scope of the present invention, and those skilled in the art should be able to Alternatives and obvious variations are intended to be included within the scope of the invention.

Claims (14)

An organic compound having the molecular structure shown by structural formula (I) or (II): Wherein, Ar is a cyclic group of C4-C7 or a cyclic group of C4-C7 containing a hetero atom; and the R ₁ and R ₂ groups may be independently selected from H, C1-C5 alkyl, respectively. One; R is selected from any of the following groups: or Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl. The organic compound as described in claim 1 is a helical biphthyl derivative. The organic compound according to claim 1, wherein Ar is any one of a benzene ring and a pyridine. The organic compound of claim 1, wherein the R group is selected from any one of the following groups: The organic compound according to any one of claims 1 to 4, which has the molecular structure represented by the structural formula (I-1) or (II-1): A method for synthesizing an organic compound, comprising: The R or S configuration of the formula (III), 1,1'-bi-2-naphthol, and the compound of the formula (IV) are reacted at 45-70 ° C to obtain an intermediate (V); wherein, X ₁ and X ₂ are each independently selected from a halogen atom; the halogen atom X ₁ in the intermediate (V) is substituted with an R group to give an organic compound of the formula (I) or (II); Wherein, the R ₁ and R ₂ groups may be independently selected from any one of H, C1-C5 alkyl; Ar is a C4-C7 cyclic group or a hetero atom-containing C4-C7 cyclic group. R; R is selected from any of the following groups: or Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl. The method of claim 6, wherein Ar is any one of a benzene ring and a pyridine. The method of claim 6, wherein the reaction between the 1,1'-bi-2-naphthol represented by the formula (III) and the compound of the formula (IV) is in the presence of a catalyst The catalyst is selected from any one or more of K ₂ CO ₃ , Na ₂ CO ₃ , NaOH, KOH, Mg/I ₂ . The method of claim 6, wherein the reaction between the 1,1'-bi-2-naphthol represented by the formula (III) and the compound of the formula (IV) is carried out at a reaction temperature of 50 -60 ° C. The method of claim 6, wherein the reaction of X ₁ in the intermediate (V) with an R group is carried out, and the intermediate (V) and RH are carried out by a Buchwald coupling reaction. An organic light-emitting element comprising at least one organic light-emitting diode, the organic light-emitting diode comprising an anode, a cathode and a light-emitting layer between the anode and the cathode, the light-emitting layer comprising at least one structural formula (I Or an organic compound of the molecular structure shown in (II): Wherein, Ar is a cyclic group of C4-C7 or a cyclic group of C4-C7 containing a hetero atom; and the R ₁ and R ₂ groups may be independently selected from H, C1-C5 alkyl, respectively. One; R is selected from any of the following groups: or Among them, Ar ₁ , Ar ₂ , Ar ₃ and Ar ₄ may be independently selected from any one of an aromatic group of C6-C20 and an aromatic group of C6-C20 substituted by C1-C5 alkyl. The organic light-emitting device according to claim 11, wherein Ar is any one of a benzene ring and a pyridine. The organic light-emitting device of claim 11, wherein the R group is selected from any one of the following groups: The organic light-emitting element according to claim 11, which is a cold light source, a display, or a mobile phone, a computer, an ATM machine, a POS machine, a game machine, a copy machine, a digital camera, a DVD, and a meter including the display. One or several.