CN101717374B - Compound comprising fork biphenyl center and preparation method thereof - Google Patents

Abstract

The present invention discloses a compound comprising a fork biphenyl center and a preparation method thereof. The invention is characterized in that 2,2',5,5'-biphenyl tetracarboxylic acid is used as a center unit to react with a side chain unit by a condensation method to obtain the novel compound comprising the fork biphenyl center. The rotatable fork biphenyl structure reduces the intermolecular interaction, enables a material to transform from a crystalline state to a amorphous state while keeping heat resistance, mechanical strength and functionality of the material, reduces a processing temperature, increases the solubility in an organic solvent, improves the processability of the material and gives novel functions and purposes at the same time.

Description

Compounds containing forked biphenyl centers and their preparation methods

technical field

The invention relates to a compound containing a biphenyl center and a preparation method thereof, and belongs to the field of preparation of small molecules and oligomers.

Background technique

The structure of a material determines its performance, and the control and modification of the structure can obtain materials with different characteristics. Due to the unique structure of aromatic compounds, materials composed of them have higher heat resistance, mechanical strength and many photoelectric activities than most aliphatic compounds. Therefore, from the field of high-performance materials to the field of organic optoelectronic materials, aromatic compounds are generally used as the main structure of materials. However, the rigid planar structure of aromatic compounds and the strong π-π interaction between molecules make the material have disadvantages such as high crystallinity, high viscous flow temperature, high viscosity, and poor solubility, making it difficult to process; at the same time, in organic optoelectronics In the field of materials, the side-by-side stacking of aromatic compound molecules is the main reason for the fluorescence quenching of the light-emitting layer of small molecules. Therefore, for a long time, people have been looking for ways to maintain the excellent heat resistance, mechanical strength and functionality of aromatic materials while realizing the transformation of materials from crystalline to amorphous states to improve their processability.

For changing the strong crystallinity of aromatic materials and suppressing the strong interaction between their molecular dipoles, the most commonly used method is to introduce long saturated alkane chains, which increases the space distance between adjacent molecules and dipoles on the one hand, and on the other hand On the one hand, it can improve the solubility of the material, making it easier to be processed. However, after modification, due to the orderly arrangement of saturated alkyl chains in space, it still has strong crystallinity, and the introduction of flexible side chains will reduce the thermal stability of molecules to a certain extent.

According to the report of Shirota and other researchers [SHIROTA YJMater.Chem.2005; 15:75], destroying the planar structure of aromatic materials makes the molecules present a fork space branched conformation, which can inhibit the crystallization behavior of materials in the solid state, and may also Realize material transition from crystalline state to amorphous glass state. So far, researchers have mainly used five ways to distort the molecular plane to form a fork space conformation to reduce the crystallinity of the material. The first type is to construct molecules centered on SP ³ hybrid tetrahedral structures such as carbon atoms, silicon atoms, and adamantane. The second type is to construct molecules centered on the [2,2] paracyclic aromatic ring structure. The third type is to construct molecules with multiple substituted benzene rings as the center. The fourth type is to build molecules with a helical structure such as spirofluorene as the center. The fifth category is to construct molecules centered on rotatable multi-substituted biaryl structures, such as biphenyl, binaphthyl, and bithiophene. Among the above molecular design concepts, the route of building molecules with a rotatable multi-substituted biphenyl center has the advantages of good thermal stability of the molecular structure, cheap and easy-to-obtain raw materials, and a simple synthesis process suitable for mass production.

Compounds containing forked biphenyl centers are a kind of multi-substituted branched compounds centered on biphenyl structures, of which four substitutions account for the majority. Due to the influence of the steric hindrance of adjacent groups, the two benzene rings of biphenyl twist to present a certain dihedral angle, and the central δ bond rotates within a certain angle, making the substituents extend in four directions, forming an "×" spatial structure , as shown in structural formula 1. The rotatable biphenyl structure can endow the molecule with a certain degree of flexibility; at the same time, the fork conformation can reduce the probability of parallel stacking between adjacent molecules, reduce the interaction between molecules, increase its free volume, and reduce its crystallinity; make the material by The crystalline state changes to an amorphous state; compared with the same type of linear molecules, the crystallinity of the formed material decreases, the processable temperature (melting point or softening point) decreases, and the solubility in organic solvents increases.

1. The general structural formula of the biphenyl central compound

Petr Holy et al first reported the synthesis method of 2,2',5,5'-biphenyltetracarboxylic acid [Holy P, Sehnal P, Tichy M, Zavada J, Cisarova I. Tetrahedron: Asymmetry.2003; 14: 245] , and found that there is a dihedral angle of 56.23° between the diphenyl rings of the central biphenyl in the solid state, as shown in Structural Formula 2. The author believes that it is due to the steric hindrance effect of adjacent groups; in the article, the author only synthesized a derivative of tetrabenzamide, as shown in structural formula 3. However, there has been no in-depth study on other biphenyl-containing compounds since then.

2.2,2',5,5'-Biphenyltetracarboxylic acid 3. Tetrabenzamide compounds

He Feng of Jilin University and others synthesized a series of phenylene vinylene oligomers centered on forked biphenyl, which were applied in the fields of electroluminescent devices and photovoltaic devices, and published many articles and patents [Adv.Funct.Mater .2007;17:1551], [Adv.Mater.2005;17,2710], [J.Mater.Chem.2004;14:2735], [Chem.Commun.2003;17,2206]; [Synthetic Metals. 2003; 135-136: 209], [Chinese Patent ZL03160019.0 "PPV Luminescent Oligomers Containing Biphenyl Centers". However, subsequent studies [Angew.Chem.Int.Ed.2007; 46:3245] showed that the phenylene vinylene oligomer with biphenyl as the core will occur when stored in the dark at room temperature [2 +2] cycloaddition reaction, as shown in reaction formula 4. It can be seen that the molecular structure with phenylene vinylene as the functional group is not stable, and it is necessary to find a functional group with better structural stability as the peripheral group building molecule of forked biphenyl.

4. [2+2] cycloaddition reaction

In addition to the several chemical structures mentioned above, other molecular structures centered on biphenyl have not been reported in patents and literature. Designing, synthesizing, and in-depth investigation of various new series of compounds containing forked biphenyl centers and their uses are of greater significance.

Contents of the invention

The object of the present invention is to provide a kind of fork-type biphenyl-containing center compound and its preparation method in view of the deficiencies in the prior art, which is characterized in that 2,2',5,5'-biphenyltetracarboxylic acid or 2,2' , 5,5'-biphenyl tetracarbonyl chloride as the central unit reacts with the side chain unit to prepare a new forked biphenyl center-containing compound.

The object of the present invention is achieved by the following technical measures, wherein the parts of raw materials are parts by weight unless otherwise specified.

1. The general structural formula of the biphenyl central compound is:

Wherein R is any one of a benzo five-membered heterocyclic compound or a thermosetting group connected by a carbonyl, an ester bond, an amide bond or a benzophenone compound, i.e. compounds I, II, III, respectively:

I: Structural formula of benzo five-membered heterocyclic compound containing forked biphenyl and its derivatives

或

或R ₁ =O or S or NH, R ₂ =——H or

or

or

中的任一种；- NH ₂ or

any of

II. Structural formula of biphenyl-containing thermosetting compounds

R ₃ =NH or O, R ₄ =-OH or -CN or -C≡CH or

or _-NH2 or -NCO or -OC≡N or

或

或 or

or

or

或

或

or

or

or

中的任一种；or

any of

III. Structural formula of benzophenone derivatives containing biphenyl

2. The chemical reaction formula of the forked biphenyl compound is as follows:

(1) The chemical reaction formula of benzo five-membered heterocyclic compound containing forked biphenyl and its derivatives

(2) The reaction formula of the thermosetting compound containing biphenyl

(3) Reaction formula of benzophenone derivatives containing biphenyl

3. Preparation of forked biphenyl compounds:

(1) Preparation of compound I

Add 1 part of 2,2',5,5'-biphenyltetracarboxylic acid, 1.3 to 3.1 parts of component A and 30 to 80 parts of polyphosphoric acid into a reaction kettle equipped with a stirrer, a thermometer and a nitrogen replacement device. Under nitrogen protection, react at a temperature of 60-70°C for 2-6 hours, 90-100°C for 2-10 hours, 120-140°C for 4-6 hours, and 150-180°C for 5-16 hours. The reaction solution was poured into ice water for precipitation, neutralized with an alkaline substance, filtered and dried to obtain compound I;

(2) Preparation of compound II

Add 1 part of 2,2',5,5'-biphenyltetracarbonyl chloride, 1.2-2.8 parts of component B, 10-20 parts of solvent and 1-2 parts of catalyst into the tank with agitator, thermometer and nitrogen replacement device In the reaction kettle, under the protection of nitrogen, react at a temperature of 0°C for 1 to 3 hours, and at room temperature for 10 to 20 hours. After the reaction, pour into water to precipitate, filter and dry to obtain compound II;

(3) Preparation of compound III

Benzyltributylammonium chloride: iron trichloride = 1:1 molar ratio was made into an ionic liquid, and then 1 part of 2,2',5,5'-biphenyl tetracarbonyl chloride, 4.7 parts of benzyl tri Add butylammonium chloride-ferric chloride ionic liquid and 0.78~1 part of component C into a reaction kettle equipped with a stirrer, thermometer and nitrogen replacement device, and react at a temperature of 50~70°C for 10~ After 60 minutes, after the reaction was completed, it was poured into water, extracted with ether, and dried over anhydrous magnesium sulfate to obtain compound III.

Component A is any one of o-aminophenol, o-aminothiophenol and o-phenylenediamine derivatives containing _R2 groups;

Component B is any one of the aniline or phenol derivatives containing the _R group;

Component C is a derivative containing R ₅ group benzene or toluene;

The solvent is any one of N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, dioxane or methylene chloride;

The catalyst is pyridine or propylene oxide;

The alkaline substance is any one of sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium carbonate, sodium hydroxide or potassium hydroxide.

Compounds containing biphenyl centers are used in the fields of electroluminescence, organic solar cells and specialty adhesives.

The present invention has the following advantages:

1. Synthesized a compound containing a forked biphenyl center. This rotatable forked biphenyl structure reduces the probability of parallel stacking between molecules, reduces the interaction between molecules, and increases the free volume;

2. Compounds containing forked biphenyl center can transform the material from crystalline state to amorphous state while maintaining the heat resistance, mechanical strength and functionality of the material;

3. Compared with the same type of linear molecules, the compound containing forked biphenyl center has lower crystallinity, lower processing temperature (melting point or softening point), and significantly higher solubility in organic solvents.

Detailed ways

The following examples are used to specifically describe the present invention. It is necessary to point out that this example is only used to further illustrate the present invention, and it cannot be interpreted as limiting the scope of protection of the invention. Those skilled in the art can according to the above-mentioned The contents of the present invention make some non-essential improvements and adjustments.

Embodiment 12,2 ', 5, the preparation of 5 '-four (benzoxazolyl) biphenyls

Add 1 part of 2,2',5,5'-biphenyltetracarboxylic acid, 1.3 parts of o-aminophenol and 30 parts of polyphosphoric acid into a reaction kettle equipped with a mechanical stirrer, a thermometer and a nitrogen replacement device. Under the condition of step-by-step heating, the reaction was carried out at 60°C for 6 hours, 90°C for 10 hours, 120°C for 4 hours, and 150°C for 5 hours. After the reaction, the reaction solution was poured into ice water to precipitate, neutralized to neutral with sodium bicarbonate, filtered and dried, decolorized with activated carbon, using ethyl acetate: n-hexane = 1:4 mixture as eluent, column chromatography After purification, 2,2',5,5'-tetrakis(benzoxazolyl)biphenyl was obtained with a yield of 78% (based on 2,2',5,5'-biphenyltetracarboxylic acid). NMR test ¹ H NMR (400MHz, CD3Cl) δ: 7.28-(m, 3H, Ar-H), 7.45(m, 2H, Ar-H), 7.54(m, 1H, Ar-H), 7.61(m, 1H, Ar-H), 7.82(m, 1H, Ar-H), 8.44(m, 1H, Ar-H), 8.58(m, 2H, Ar-H).C40H22N4O4(622); elemental analysis theoretical value: C, 77.16; H, 3.56; N, 9.00; Found: C, 77.20; H, 3.53; N, 8.95.

Embodiment 22,2', 5, the preparation of 5'-tetra(5-tert-butylbenzothiazolyl) biphenyl

Add 1 part of 2,2',5,5'-biphenyltetracarboxylic acid, 2.5 parts of 2-amino-4-tert-butylthiophenol and 80 parts of polyphosphoric acid into the In the reaction kettle of the device, under the protection of nitrogen, the temperature was raised step by step, and the reaction was performed at a temperature of 70°C for 2 hours, 90°C for 2 hours, 135°C for 6 hours, and 180°C for 16 hours. Then the reaction solution was poured into ice water for precipitation, neutralized with sodium bicarbonate, and dried by filtration. Then use activated carbon to decolorize, and recrystallize in trifluoroacetic acid to obtain 2,2',5,5'-tetrakis(5-tert-butylbenzothiazolyl)biphenyl, with a yield of 89% (based on 2,2',5 , 5'-biphenyltetracarboxylic acid). NMR test ¹ H NMR (400MHz, DMSO-d ₆ ) δ: 1.40-(s, 6H, CH ₃ ), 7.56(m, 2H, Ar-H), 7.73(m, 1H, Ar-H), 7.93( m, 4H, Ar-H), 7.82 (m, 1H, Ar-H), 8.23 (m, 2H, Ar-H).C ₅₆ H ₅₄ N ₄ S ₄ (910); elemental analysis theoretical value: C, 73.81; H, 5.97; N, 6.15; S, 14.07; Found: C, 73.85; H, 5.94; N, 6.05;

Example 3 Preparation of four (4-(maleimido) phenyl) biphenyl-2,2',5,5'-tetracarboxylate

Add 1.9 parts of N-(4-hydroxyphenyl)maleimide, 8 parts of N-methylpyrrolidone and 1 part of pyridine into a reaction kettle equipped with a mechanical stirrer, a thermometer and a nitrogen replacement device, under nitrogen protection , Add 1 part of 2,2',5,5'-biphenyl tetracarbonyl chloride dissolved in 2 parts of N-methylpyrrolidone dropwise into the above reaction kettle. Respectively react at 0°C for 1 hour and at room temperature for 10 hours. Then the reaction solution was poured into water to precipitate, filtered, and the filter cake was collected and dried. Using ethyl acetate:n-hexane = 1:1 mixed solution as eluent, column chromatography purification to obtain tetrakis(4-(maleimido)phenyl)biphenyl-2,2',5,5' -Tetracarboxylic acid ester, the yield is 85% (calculated as 2,2',5,5'-biphenyl tetracarbonyl chloride). NMR test ¹ H NMR (400MHz, DMSO-d ₆ ) δ: 6.94 (m, 4H, C=CH), 7.37 (m, 8H, Ar-H), 8.00 (m, 1H, Ar-H), 8.43 ( m, 1H, Ar-H), 8.93 (m, 1H, Ar-H).C ₅₆ H ₃₀ N ₄ O ₁₆ (1014); elemental analysis theoretical value: C, 66.28; H, 2.98; N, 5.52; O , 25.22; Found: C, 66.31; H, 2.93; N, 5.50.

Example 4 Preparation of four (4-(3,4-dicyanophenoxy) phenyl) biphenyl-2,2',5,5'-tetracarboxamide

2.6 parts of 4-(4-aminophenoxy)phthalonitrile, 1 part of 2,2',5,5'-biphenyl tetracarbonyl chloride, 20 parts of N-methylpyrrolidone and 2 parts of propylene oxide Add them into a reaction kettle equipped with a mechanical stirrer, a thermometer and a nitrogen replacement device, and react at a temperature of 0° C. for 1 hour and at room temperature for 13 hours under nitrogen protection. Then pour the reaction solution into water to precipitate, filter, collect the filter cake and dry it, and recrystallize it with methanol to obtain tetrakis(4-(3,4-dicyanophenoxy)phenyl)biphenyl-2,2',5 , 5'-tetracarboxamide, yield 81% (based on 2,2',5,5'-biphenyl tetracarbonyl chloride). NMR test ¹ H NMR (400MHz, DMSO-d ₆ ) δ: 6.93 (m, 4H, Ar-H), 7.44 (m, 2H, Ar-H), 7.58 (m, 4H, Ar-H), 7.94 ( m, 2H, Ar-H), 8.16(m, 3H, Ar-H), 8.27(m, 1H, Ar-H), 8.78(m, 1H, Ar-H). 10.27(m, 2H, NH) C ₇₂ H ₃₈ N ₁₂ O ₈ (1198); Elemental Analysis Calc: C, 72.12; H, 3.19; N, 14.02; O, 10.67; Found: C, 72.19; H, 3.15; N, 13.98.

The preparation of embodiment 52,2', 5,5'-tetrakis(benzophenone)biphenyl

Add 4.7 parts of ionic liquid configured with benzyltributylammonium chloride:ferric chloride=1:1 molar ratio, 1 part of 2,2',5,5'-biphenyl tetracarbonyl chloride and 0.78 parts of benzene In a reaction kettle equipped with a mechanical stirrer, a thermometer and a nitrogen replacement device, under the protection of nitrogen, react at a temperature of 50° C. for 20 minutes. Poured into water again, extracted with ether, dried over anhydrous magnesium sulfate, evaporated ether and dried in vacuum to obtain 2,2',5,5'-tetrakis(benzophenone)biphenyl with a yield of 91% (based on 2,2 ', 5,5'-biphenyl tetracarbonyl chloride). NMR test ¹ H NMR (400MHz, DMSO-d ₆ ) δ: 7.53 (m, 4H, Ar-H), 7.64 (m, 2H, Ar-H), 7.79 (m, 4H, Ar-H), 7.96 ( m, 1H, Ar-H), 7.84 (m, 1H, Ar-H), 8.48 (m, 1H, Ar-H), C ₄₀ H ₂₆ O ₄ (570); elemental analysis theoretical value: C, 84.19; H, 4.59; O, 11.22; Found: C, 84.21; H, 4.54; O, 11.20.

Claims (5)

1. The compound containing forked biphenyl center is characterized in that the structural formula of the compound is: R ₁ =O or S or NH, R ₂ =——H or

- NH ₂ or

any of the. 2. the preparation method of the compound containing biphenyl center as claimed in claim 1, is characterized in that the method comprises the following steps: Add 1 part by weight of 2,2',5,5'-biphenyltetracarboxylic acid, 1.3 to 3.1 parts by weight of component A and 30 to 80 parts by weight of polyphosphoric acid into a reactor equipped with a stirrer, a thermometer and a nitrogen replacement device In the process, under nitrogen protection, react at a temperature of 60-70°C for 2-6 hours, 90-100°C for 2-10 hours, 120-140°C for 4-6 hours, and 150-180°C for 5-16 hours. After the reaction, the reaction solution was poured into ice water for precipitation, neutralized with an alkaline substance, filtered and dried to obtain Compound I, whose chemical reaction formula is:

Component A Component A I R ₁ =O or S or NH, R ₂ =——H or

- NH ₂ or

any of the. 3. the preparation method of the compound containing forked biphenyl center as claimed in claim ₂ , is characterized in that component A is containing R in the ortho-aminophenol of group, ortho-aminothiophenol or ortho-phenylenediamine derivative any kind. 4. the preparation method of the compound containing forked biphenyl center as claimed in claim 2 is characterized in that alkaline substance is sodium carbonate, sodium bicarbonate, potassium bicarbonate, salt of wormwood, sodium hydroxide or potassium hydroxide any kind. 5. the application of the compound containing forked biphenyl center as claimed in claim 1 in electroluminescence, organic solar cells and special adhesives.