CN111995734B - A kind of cage-type polysilsesquioxane-based star-shaped hybrid helical polyisonitrile and its preparation method and application - Google Patents

Abstract

The invention discloses a cage-type polysilsesquioxane (POSS)-based star-shaped hybrid helical polyisonitrile and a preparation method and application thereof. The structure is shown in the following general formula:

In the formula,

During its preparation, an aminated POSS is first synthesized, then an amidation reaction is used to introduce an alkynyl group, an organic/inorganic hybrid palladium catalyst is obtained by reacting with palladium, and then isonitrile polymerization is initiated to prepare a POSS-based star hybrid helix polyiso Nitrile. The invention combines organic materials with inorganic materials, the prepared catalyst has good catalytic ability, and the star-shaped hybrid helical polyisonitrile can be easily and conveniently obtained. The polymer obtained by the catalyst has an eight-armed star-shaped helical structure with high molecular weight and narrow molecular weight distribution. It has great potential applications in the fields of self-assembly, drug loading, chiral separation, and dye adsorption.

Description

A kind of cage-type polysilsesquioxane-based star-shaped hybrid helical polyisonitrile and its preparation method and application

technical field

The invention belongs to the field of polymer catalytic reaction and preparation of functional polymers, in particular to a cage-type polysilsesquioxane (POSS)-based star-shaped hybrid helical polyisonitrile and a preparation method and application thereof.

Background technique

Polyisonitrile is a synthetic polymer with stable helical conformation that can be used for chiral recognition, enantiomeric separation and asymmetric catalysis. It is very popular due to its easy availability of monomers and simple polymerization method. In the past few decades, various functional polyisonitrile have been reported one after another. However, most of these polyisonitrile are linear, but the research on hybrid star polyisonitrile is rare. Compared with linear polymers, star polymers have smaller dynamic mechanical dimensions in solution, and have the characteristics of low solution and bulk viscosity, which is of great significance for polymer processing.

Cage silsesquioxane (POSS) is a new type of material whose inner core is Si-O-Si linked and the periphery is a substituent group. It has a caged core composed of inorganic silicon-oxygen-silicon structure and organic branches, and is a good molecular-level nano-organic/inorganic hybrid material. Since the vertices of POSS can introduce reactive functional groups and have strong molecular design, POSS can be introduced into polymer systems as a good nanostructure. Therefore, on this basis, organic/inorganic hybrids with novel structures are designed and synthesized. The star-shaped hybrid helical polyisonitrile prepared by the material as a catalyst for polymerization has great potential application value.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a cage-type polysilsesquioxane (POSS)-based star-shaped hybrid helical polyisonitrile and its preparation method and application.

In order to achieve the above object, the present invention provides the following technical solutions:

式中

An organic/inorganic hybrid palladium catalyst, the structure of which is shown in the following general formula:

in the formula

A kind of preparation method of organic/inorganic hybrid palladium catalyst, operate according to the following steps:

a. Dissolve octaamino POSS and reagent A in dichloromethane, add reagent B and triethylamine to react at room temperature for 22-25h under nitrogen or argon atmosphere, stop the reaction; separate the organic phase, wash, purify, dry , After the solvent was removed by evaporation, dichloromethane was added and the intermediate I was obtained by precipitation with diethyl ether;

b, adding bis(triethylphosphine) palladium dichloride, cuprous chloride and intermediate I to dichloromethane, and adding triethylamine to stir the reaction at room temperature for 2.5-3.5h under nitrogen or argon atmosphere , after the solvent is removed by rotary evaporation, the crude product is purified and dried to obtain an organic/inorganic hybrid palladium catalyst;

Wherein, the structural formula of intermediate I is:

式中

in the formula

Described reagent A is any one in propargyl alcohol ring-opening succinic anhydride, glutaric anhydride, adipic anhydride;

The reagent B is 1-hydroxybenzotriazole, O-benzotriazole-tetramethylurea hexafluorophosphate, 4-dimethylaminopyridine, 1-ethyl-(3-dimethylamino) propyl) one or more of carbodiimide hydrochloride and dicyclohexylcarbodiimide.

Preferably, when reagent A is monopropynyl succinate and reagent B is O-benzotriazole-tetramethylurea hexafluorophosphate:

In step a, the molar ratio of octaamino POSS, monopropynyl succinate, O-benzotriazole-tetramethylurea hexafluorophosphate and 1-hydroxybenzotriazole is 0.17: (4-8) :2.73:2.73;

In step b, the molar ratio of bis(triethylphosphine)palladium dichloride, cuprous chloride and intermediate I is 2:0.2:0.25.

Preferably, in step a, the organic phase is separated and taken, washed, purified, dried, evaporated to remove the solvent, and then the specific process of adding dichloromethane and precipitating with ether to obtain the intermediate I is as follows: take the organic phase with dichloromethane, and sequentially use saturated chlorine After washing 3-4 times with ammonium chloride solution, saturated sodium bicarbonate solution and saturated sodium chloride solution, add anhydrous sodium sulfate to dry, evaporate the solvent to obtain crude product, dissolve in dichloromethane, and add dropwise to frozen ether , the solid intermediate I was collected by suction filtration.

Preferably, the volume ratio of dichloromethane and frozen ether in step a is 1:10.

Preferably, the specific process of purification and drying in step b is as follows: the crude product is purified by silica gel column chromatography, and the palladium catalyst is obtained by vacuum drying, wherein the eluent is firstly a mixture of petroleum ether and ethyl acetate, and then is changed to methanol , and collect the methanol solution and spin dry; wherein, the volume ratio of petroleum ether and ethyl acetate in the eluent is 1:1, and the volume ratio of the mixture of petroleum ether and ethyl acetate to methanol is 5:3.

A cage-type polysilsesquioxane-based star-shaped hybrid helical polyisonitrile, the general structural formula of which is as follows:

Among them, polymerization degree m=10～60;

A preparation method of cage-type polysilsesquioxane-based star-shaped hybrid helical polyisonitrile, the specific steps are as follows:

Add organic/inorganic hybrid palladium catalyst and phenylisonitrile monomer to the polymerization bottle, under anhydrous and oxygen-free conditions, vacuum and fill with nitrogen, add dry solvent tetrahydrofuran, and reflux at 55-60°C for 20-24h. Methanol was added to terminate the reaction, and the obtained product was washed with methanol, and then vacuum-dried until the quality did not change to obtain a phenylisonitrile polymer;

Wherein, the structural formula of described benzonitrile monomer is:

In the formula,

Preferably, the molar ratio of the organic/inorganic hybrid palladium catalyst and the benzonitrile monomer is 1: (10-60), when the input amount of the benzonitrile monomer is 30-100mg, the solvent tetrahydrofuran is added The amount is 1-3 mL.

The application of a cage-type polysilsesquioxane-based star-shaped hybrid helical polyisonitrile can be used in the fields of functional polymer materials, drug carriers, nanotechnology, self-assembly, chiral separation, dye adsorption, and smart materials.

Compared with the prior art, the beneficial effects of the present invention are:

1. The preparation of the cage-type polysilsesquioxane (POSS)-based star-shaped hybrid helical polyisonitrile in the present invention is simple, the requirements for experimental conditions are not harsh, the operation is convenient, and the reaction is easy to carry out.

2. Compared with the single-chain polymer, the star-shaped hybrid helical polyisonitrile obtained by the organic/inorganic hybrid palladium catalyst has a more regular structure, higher molecular weight and lower molecular weight distribution.

3. The invention combines organic materials and inorganic materials, and has great application value in the fields of self-assembly, drug loading, chiral separation, dye adsorption and the like.

Description of drawings

Fig. 1 is the hydrogen nuclear magnetic spectrum of the organic/inorganic palladium catalyst in Example 1 of the present invention, and it can be proved that the organic/inorganic palladium catalyst is obtained.

FIG. 2 is a gel permeation chromatogram of the chiral C ₁₀ isonitrile polymer in Example 2 of the present invention, which can prove that a high molecular weight polymer is obtained.

Fig. 3 is the circular dichroism diagram of the chiral C ₁₀ isonitrile polymer in Example 2 of the present invention, which can prove that the obtained polyisonitrile has chirality.

4 is the critical micelle concentration of the chiral C ₁₀ isonitrile block three-armed hydrophilic isonitrile in Example 3 of the present invention, which can prove that the obtained polyisonitrile can self-assemble.

5 is a dynamic light scattering diagram of a chiral C ₁₀ isonitrile block three-armed hydrophilic isonitrile in Example 3 of the present invention, and the particle size of the obtained polyisonitrile after self-assembly can be measured.

6 is an atomic force microscope image of the chiral C ₁₀ isonitrile block three-armed hydrophilic isonitrile in Example 3 of the present invention, and the morphology of the polyisonitrile after self-assembly can be observed.

Detailed ways

Embodiment 1: the preparation method of organic/inorganic hybrid palladium catalyst

a. Dissolve 0.17mmol (0.20g) of octaamino POSS and 4.09mmol (0.63g) of monopropynyl succinate into 50mL of dichloromethane, add 2.73mmol (1.03g) of O-benzotriazepine azole-tetramethylurea hexafluorophosphate, 2.73 mmol (0.37 g) of 1-hydroxybenzotriazole and 10 mL of triethylamine. In a nitrogen atmosphere, the reaction was carried out at room temperature for 24 h, and the reaction was stopped. The organic phase was taken with 30 mL of dichloromethane, washed 3 times with saturated ammonium chloride solution, saturated sodium bicarbonate solution, and saturated sodium chloride solution in turn, dried by adding anhydrous sodium sulfate, and evaporated to remove the solvent to obtain a crude product. Add 2 mL of dichloromethane and precipitate with 20 mL of ether to obtain Intermediate I; the structural formula is as follows:

式中

in the formula

b. 2 mmol (726.64 mg) of bis(triethylphosphine) palladium dichloride, 0.2 mmol (19.95 mg) of cuprous chloride and 0.25 mmol (500.00 mg) of intermediate I were added to 10 mL of dichloromethane In addition, 10 mL of triethylamine was added. The reaction was stirred at room temperature for 3 h under a nitrogen atmosphere, and the solvent was removed by rotary evaporation. ) purification, obtain 200mg yellow liquid after vacuum drying and be palladium catalyst, and the structural formula of palladium catalyst is as follows:

式中

in the formula

The synthetic route of organic/inorganic hybrid palladium catalyst of the present invention is as follows:

in the formula

Example 2: Initiation of Chiral _C10 Isonitrile Polymerization

The polymerization of chiral C ₁₀ isonitrile was carried out under anhydrous and oxygen-free conditions, and 1.60 mg (0.0003 mmol) of the palladium catalyst prepared in Example 1 and 19.31 mg (0.0614 mmol) of the chiral C ₁₀ isonitrile monomer were added to a 10 mL polymerization flask. mmol), vacuumed and filled with nitrogen for 3 times, added 1 mL of dry tetrahydrofuran, refluxed at 55 °C for 8 h, quenched by adding 10 mL of methanol to precipitate the polymer, washed 5 times with methanol, and centrifuged to obtain a yellow flocculent precipitate , vacuum-dried to the same quality.

The structural formula of the phenyl isonitrile monomer in the present embodiment is:

The structural formula of the obtained product is:

Example 3: Chiral _C10 isonitrile block three-armed hydrophilic isonitrile

15.2 mg of the polymer prepared in Example 2 and 139.81 mg (0.19 mmol) of the three-arm hydrophilic isonitrile monomer were added to a 10 mL polymerization bottle, vacuumed and filled with nitrogen for 3 times, and 0.8 mL of dry tetrahydrofuran was added, and the reaction was carried out under reflux at 55°C. After 20 hours, 10 mL of methanol was added for quenching to precipitate the polymer, which was washed 5 times with methanol, and centrifuged to obtain a white flocculent precipitate, which was dried in vacuum until the quality remained unchanged.

The structural formula of the phenyl isonitrile monomer in the present embodiment is:

The structural formula of the obtained product is:

Example 4: Chiral _C10 Isonitrile Blocked Pentafluorophenol Isonitrile

Add 15.2 mg of the polymer prepared in Example 2 and 3.78 mg (0.01 mmol) of pentafluorophenol isonitrile monomer into a 10 mL polymerization bottle, vacuum and fill with nitrogen for 3 times, add 0.8 mL of dry tetrahydrofuran, and reflux at 55 °C for 20 h. Then, 10 mL of methanol was added for quenching, so that the polymer was precipitated, washed with methanol for 5 times, and centrifuged to obtain a white flocculent precipitate, which was vacuum-dried until the quality remained unchanged.

The structural formula of the phenyl isonitrile monomer in the present embodiment is:

The structural formula of the obtained product is:

The present invention illustrates the detailed technological process of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed technological process, that is, it does not mean that the present invention must rely on the above-mentioned detailed technological process to be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (6)

1. an organic/inorganic hybrid palladium catalyst is characterized in that, its structure is shown in the following general formula:

, where R ₂ =

. 2. a preparation method of organic/inorganic hybrid palladium catalyst as claimed in claim 1, is characterized in that, operate according to the following steps: a. Dissolve octaamino POSS and reagent A in dichloromethane, add reagent B and triethylamine to react at room temperature for 22-25 h under nitrogen or argon atmosphere, and stop the reaction; separate the organic phase, wash, purify, After drying, evaporation of the solvent, addition of dichloromethane and precipitation with ether to give Intermediate I; b. Add bis(triethylphosphine) palladium dichloride, cuprous chloride and intermediate I to dichloromethane, and add triethylamine to stir the reaction at room temperature for 2.5-3.5 h under nitrogen or argon atmosphere , after the solvent is removed by rotary evaporation, the crude product is purified and dried to obtain an organic/inorganic hybrid palladium catalyst; Wherein, the structural formula of intermediate I is:

, where R ₁ =

; Described reagent A is any one in propargyl alcohol ring-opening succinic anhydride, glutaric anhydride, adipic anhydride; The reagent B is 1-hydroxybenzotriazole, O-benzotriazole-tetramethylurea hexafluorophosphate, 4-dimethylaminopyridine, 1-ethyl-(3-dimethylamino) propyl) one or more of carbodiimide hydrochloride and dicyclohexylcarbodiimide. 3. the preparation method of organic/inorganic hybrid palladium catalyst according to claim 2, is characterized in that: When reagent A is monopropynyl succinate and reagent B is O-benzotriazole-tetramethylurea hexafluorophosphate: In step a, the molar ratio of octaamino POSS, monopropynyl succinate, O-benzotriazole-tetramethylurea hexafluorophosphate and 1-hydroxybenzotriazole is 0.17: (4-8) :2.73:2.73; In step b, the molar ratio of bis(triethylphosphine)palladium dichloride, cuprous chloride and intermediate I is 2:0.2:0.25. 4. the preparation method of organic/inorganic hybrid palladium catalyst according to claim 2, is characterized in that: In step a, the organic phase is separated and taken, washed, purified, dried, evaporated to remove the solvent, then added with dichloromethane and precipitated with ether to obtain the intermediate I. The specific process is as follows: the organic phase is taken with dichloromethane, followed by saturated ammonium chloride solution. After washing 3-4 times with saturated sodium bicarbonate solution and saturated sodium chloride solution, add anhydrous sodium sulfate to dry, evaporate the solvent to obtain a crude product, dissolve it in dichloromethane, add dropwise to frozen ether, and extract Solid Intermediate I was collected by filtration. 5. the preparation method of organic/inorganic hybrid palladium catalyst according to claim 4, is characterized in that: In step a, the volume ratio of dichloromethane and frozen ether is 1:10. 6. the preparation method of organic/inorganic hybrid palladium catalyst according to claim 2, is characterized in that: The specific process of purification and drying in step b is as follows: the crude product is purified by silica gel column chromatography, and the palladium catalyst is obtained by vacuum drying, wherein, the eluent is firstly a mixture of petroleum ether and ethyl acetate, and then is changed to methanol, and collected. The methanol solution was spin-dried; wherein, the volume ratio of petroleum ether and ethyl acetate in the eluent was 1:1, and the volume ratio of the mixture of petroleum ether and ethyl acetate to methanol was 5:3.

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