CN114276522B - Acidic hydroxyl conjugated microporous polymer modified by deep eutectic solvent and preparation method thereof - Google Patents

Abstract

The invention provides an acidic hydroxyl-conjugated microporous polymer modified by a deep eutectic solvent and a preparation method thereof. Sonogashira‑Hagihara cross-coupling chemistry with dimethylformamide and 2,6‑diisopropylaniline as reaction solvents. In addition, through the modification of the deep eutectic solvent, a certain amount of nitrogen doping is added to OH‑CMP, which enriches the element types of OH‑CMP materials and can improve the application of OH‑CMP as other composite materials. The preparation method is simple and the raw materials are readily available, and the obtained conjugated microporous polymer (DESs-OH-CMP) modified with DESs-OH functional groups has high application value in adsorption, electrochemistry and the like.

Description

Acidic hydroxyl conjugated microporous polymer modified by deep eutectic solvent and preparation method thereof

technical field

The invention relates to the technical field of preparation of conjugated microporous polymers, in particular to an acidic hydroxyl conjugated microporous polymer modified by a deep eutectic solvent and a preparation method thereof.

Background technique

Conjugated microporous polymers (CMPs) are a unique class of materials. Since their discovery in 2007, conjugated microporous polymers have become an important class of microporous materials. CMPs are a unique class of microporous materials consisting only of covalent bonds formed by light elements (carbon, hydrogen, etc.), which combine π-π conjugation with a permanent microporous framework, which makes CMPs excellent in gas adsorption and separation , chemical adsorption and encapsulation, heterogeneous catalysis, photoredox catalysis and other fields have potential application prospects. A wide range of synthetic building blocks and network-forming reactions provides a large number of CMPs with diverse properties and structures. However, as an adsorption material, the adsorption effect of CMP is average, and the adsorption selectivity is average. In addition, the elements of CMP are relatively single, and the application of CMP materials is relatively limited.

Contents of the invention

The purpose of the present invention is to provide a deep eutectic solvent-modified acidic hydroxyl conjugated microporous polymer and its preparation method to solve the problems in the prior art that the CMP material is relatively single and has few applications in adsorption and extraction.

The technical scheme adopted in the present invention is: an acidic hydroxyl conjugated microporous polymer modified by a deep eutectic solvent, which is uniformly mixed with a deep eutectic solvent and an acidic hydroxyl conjugated microporous polymer, and then heated at 70-90°C Heating under low temperature for 6-10h, after the reaction, the solid-liquid mixture is separated, and the obtained solid is the acidic hydroxyl-conjugated microporous polymer modified by the deep eutectic solvent after washing and drying; wherein, the deep eutectic solvent Be ethylene glycol and choline chloride, phenol and choline chloride, urea and choline chloride or methanesulfonic acid and choline chloride; the structural formula of the acidic hydroxyl-conjugated microporous polymer is as follows:

。

.

The molar ratio of the deep eutectic solvent to the acidic hydroxyl conjugated microporous polymer is 10-12:1.

The acidic hydroxyl conjugated microporous polymer is prepared by the following method:

Put 1,3,5-triethynylbenzene, 2,4,6-tribromoaniline, tetrakis(triphenylphosphine)palladium and copper iodide in a reaction vessel, then add N,N-dimethylformamide and 2,6-diisopropylaniline, after excluding the air, introduce circulating argon, the mixture is stirred in an oil bath at 70-90°C for 20-28h, after the reaction is completed, the solid-liquid mixture is separated, and the obtained solid is washed, methanol After extraction and drying, the acidic hydroxyl-conjugated microporous polymer is obtained.

The reaction formula for preparing acidic hydroxyl-conjugated microporous polymers is as follows:

。

.

The mass ratio of 1,3,5-triethynylbenzene to 2,4,6-tribromoaniline is 0.4-0.5:1; the mass ratio of 1,3,5-triacetylene to copper iodide is 7- 9:1.

The mass ratio of tetrakis(triphenylphosphine) palladium to copper iodide is 5-7:1; the volume ratio of solvent N,N-dimethylformamide to 2,6-diisopropylaniline is 1-2: 1.

A method for preparing an acidic hydroxyl-conjugated microporous polymer modified by a deep eutectic solvent, which comprises uniformly mixing a deep eutectic solvent and an acidic hydroxyl-conjugated microporous polymer, and then heating at 70-90°C for 6-10 hours After the reaction, the solid-liquid mixture is separated, and the obtained solid is the acidic hydroxyl conjugated microporous polymer modified by the deep eutectic solvent after washing and drying; wherein, the deep eutectic solvent is ethylene glycol and chlorine choline, phenol and choline chloride, urea and choline chloride or methanesulfonic acid and choline chloride; the structural formula of the acidic hydroxyl conjugated microporous polymer is as follows:

。

.

The molar ratio of the deep eutectic solvent to the acidic hydroxyl conjugated microporous polymer is 10-12:1.

The acidic hydroxyl conjugated microporous polymer is prepared by the following method;

Put 1,3,5-triethynylbenzene, 2,4,6-tribromoaniline, tetrakis(triphenylphosphine)palladium and copper iodide in a reaction vessel, then add N,N-dimethylformamide and 2,6-diisopropylaniline, after excluding the air, introduce circulating argon, the mixture is stirred in an oil bath at 70-90°C for 20-28h, after the reaction is completed, the solid-liquid mixture is separated, and the obtained solid is washed, methanol After extraction and drying, the acidic hydroxyl-conjugated microporous polymer is obtained; the reaction formula for preparing the acidic hydroxyl-conjugated microporous polymer is as follows:

。

.

The mass ratio of 1,3,5-triethynylbenzene to 2,4,6-tribromoaniline is 0.4-0.5:1; the mass ratio of 1,3,5-triacetylene to copper iodide is 7- 9:1; the mass ratio of tetrakis(triphenylphosphine) palladium to copper iodide is 5-7:1; the volume ratio of solvent N,N-dimethylformamide to 2,6-diisopropylaniline is 1-2:1.

The preparation mainly involves tetrakis(triphenylphosphine) palladium and copper iodide catalyzed Sonogashira - Hagihara cross-coupling chemistry. OH-CMP was synthesized.

In addition, through the modification of deep eutectic solvents (Deep Eutectic Solvents), OH-CMP has a certain amount of nitrogen doping, which enriches the element types of OH-CMP materials and can improve the application of OH-CMP as other composite materials. , such as the application of electrochemical materials.

The preparation method has simple process and easy-to-obtain raw materials, and the prepared OH-CMP improves the selectivity of CMP as an adsorbent. And through the modification of DESs, the multi-element doping of OH-CMP was carried out. The obtained DESs modified -OH functional group conjugated microporous polymer (DESs-OH-CMP) has high application value in adsorption and electrochemistry.

The beneficial effects of the present invention are:

1) The present invention provides a method for selecting functional groups from reactive monomers to synthesize conjugated microporous polymers containing acidic hydroxyl groups, which provides a new way to improve the adsorption selectivity of conjugated microporous polymer materials;

2) The acidic hydroxyl-conjugated microporous polymers were modified by using different deep eutectic solvents, and the characterization data confirmed that the modification of the deep eutectic solvents carried out multi-element doping on the acidic hydroxyl-conjugated microporous polymers; increased acidity The element type of the hydroxyl-conjugated microporous polymer improves the application value of the acidic hydroxyl-conjugated microporous polymer.

Description of drawings

Fig. 1 is a scanning electron microscope image of OH-CMP of the present invention.

Fig. 2 is an infrared diagram of OH-CMP of the present invention.

Fig. 3 is the adsorption-desorption curve diagram of OH-CMP of the present invention.

Fig. 4 is an X-ray diffraction pattern of OH-CMP of the present invention.

Fig. 5 is a thermogravimetric analysis diagram of OH-CMP of the present invention.

Fig. 6 is a scanning electron micrograph of DESs-OH-CMP of the present invention.

Fig. 7 is an infrared diagram of DESs-OH-CMP of the present invention.

Fig. 8 is an adsorption-desorption curve diagram of DESs-OH-CMP of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with specific examples, and the reagents and operations not mentioned in the examples are all implemented according to conventional operations in the art.

Example 1:

Preparation steps of OH-CMP: Take 1,3,5-triethynylbenzene (181.60 mg), 2,4,6-tribromophenol (400.00 mg), tetrakis(triphenylphosphine) palladium (139.73 mg), Copper iodide (23.00 mg) was placed in a 25.00 mL three-neck round bottom flask, then 6.00 mL DMF and 6.00 mL DIPA were added, and argon gas was circulated after the air was excluded. The mixture was stirred in an oil bath at 80°C for about 24 h. After the reaction, the solid-liquid mixture was suction-filtered, and the upper layer solid was taken, and then filtered and washed with dichloromethane and methanol solvents for several times to remove unreacted monomers and catalysts. Finally, Soxhlet extraction was performed with methanol for 3 days, and the resulting product was dried at 100 °C for 24 hours until the weight was constant. The resulting product was characterized, and the results are shown in Figures 1-5.

The preparation steps of DESs-OH-CMP: the deep eutectic solvent based on alcoholic hydroxyl group is formed by mixing and heating ethylene glycol and choline chloride at a molar ratio of 1:3 at 80 °C; DESs (ethylene glycol: choline chloride) and OH-CMP at a molar ratio of 10:1 and heated at 80 °C for 8 h. After the reaction, the solid-liquid mixture was suction-filtered, and the upper solid was taken, washed several times with pure water, and vacuum-dried at 80 °C for 6 h to obtain DESs (ethylene glycol:choline chloride)-OH-CMP material. Then do scanning electron microscopy, infrared, BET characterization. The results are shown in the graphs or curves labeled 1 in FIGS. 6 and 7 .

Example 2:

The preparation steps of OH-CMP are the same as in Example 1.

The deep eutectic solvent based on phenolic hydroxyl group is prepared by mixing and heating phenol and choline chloride at a molar ratio of 1:2 at 80°C; DESs (phenol:choline chloride) and OH-CMP at a molar ratio of 10:1 are Heated at low temperature for 8 h, filtered, washed, and dried in vacuum at 80 °C for 6 h to obtain DESs (phenol:choline chloride)-OH-CMP material. Then do scanning electron microscopy, infrared, BET characterization. The results are shown in the graphs or curves labeled 2 in FIGS. 6 and 7 .

Example 3:

The preparation steps of OH-CMP are the same as in Example 1.

The amide-based deep eutectic solvent is prepared by mixing and heating urea and choline chloride at a molar ratio of 1:2 at 80°C; DESs (urea:choline chloride) and OH-CMP at a molar ratio of 10:1 are heated Heated under low temperature for 8 h, filtered, washed, and dried in vacuum at 80 °C for 6 h to obtain DESs (urea: choline chloride)-OH-CMP material. Then do scanning electron microscopy, infrared, BET characterization. The results are shown in the graphs or curves labeled 3 in FIGS. 6 and 7 .

Example 4:

The preparation steps of OH-CMP are the same as in Example 1.

The deep eutectic solvent based on sulfonic acid group is formed by mixing and heating methanesulfonic acid and choline chloride at a molar ratio of 1:2 at 80 ℃; DESs (methylsulfonic acid: choline chloride) and OH-CMP molar Heated at 80 °C for 8 h at a ratio of 10:1, filtered, washed, and dried in vacuum at 80 °C for 6 h to obtain DESs (methanesulfonic acid: choline chloride)-OH-CMP material. Then do scanning electron microscopy, infrared, BET characterization. The result is shown in the figure or curve marked as 4 in FIGS. 6 and 7 .

Example 5:

The changes before and after DESs modification of OH-CMP were analyzed by BET method. The specific operations were as follows: firstly weigh and record the weight of the empty tube, then take about 0.1 g OH-CMP and 0.1 g DESs-OH-CMP prepared in Example 1 and put them in into the tube, weigh and record the weight of the tube after placing the sample. After weighing, install the sample tubes in order. After installing the sample tube, start the vacuum. After vacuuming, after the heating window appears, change the pressure in the pretreatment parameters to 10 MPa, set the furnace temperature, turn on the heating switch, and raise the furnace manually. After the heating is over, a prompt window will pop up automatically. After the temperature of the sample tube drops to room temperature, after 2 seconds, install the liquid nitrogen tank and cover the foam pad. The liquid nitrogen tank will automatically rise in about 5 minutes, and the adsorption-desorption curve measurement will start ( 12-24h). After the measurement is over, a window for inputting the sample weight will pop up, and the liquid nitrogen tank will automatically fall down, and the remaining liquid nitrogen will be poured back. The OH-CMP and DESs-OH-CMP samples were removed.

The results of the nitrogen adsorption-desorption curves in Figure 3 and Figure 8 show that the OH-CMP material belongs to the composite composition of type I and type II isotherms, this is because the OH-CMP material has a very obvious adsorption amount at the low end of P/P0, which is different from that of The OH-CMP material is related to the micropore filling, which belongs to the activated carbon type and contains narrow crack pores. But after modified by DESs, the DESs-OH-CMP material belongs to the gas adsorption generated by non-porous or macroporous materials, because the type II isotherm reflects the unrestricted monolayer-multilayer adsorption, and the monolayer adsorption is completed and ended; this Part of the curve is a more gradual bend, indicating that the amount of monolayer coverage and the initial amount of multilayer adsorption superimpose. When P/P0=1, no plateau has been formed, the adsorption has not yet reached saturation, and the thickness of multilayer adsorption seems to be able to increase without limit.

Claims (7)

1. an acidic hydroxy-conjugated microporous polymer modified by a deep eutectic solvent, characterized in that the deep eutectic solvent is mixed with the acidic hydroxy-conjugated microporous polymer, and then heated at 70-90°C for 6- After 10 h, the solid-liquid mixture is separated after the reaction, and the obtained solid is the acidic hydroxyl-conjugated microporous polymer modified by the deep eutectic solvent after washing and drying; wherein, the deep eutectic solvent is ethylene glycol and Choline chloride, phenol and choline chloride, urea and choline chloride, or methanesulfonic acid and choline chloride; The acidic hydroxyl conjugated microporous polymer is prepared by the following method: Put 1,3,5-triethynylbenzene, 2,4,6-tribromoaniline, tetrakis(triphenylphosphine)palladium and copper iodide in a reaction vessel, then add N,N-dimethylformamide and 2,6-diisopropylaniline, after excluding the air, introduce circulating argon, the mixture is stirred in an oil bath at 70-90°C for 20-28h, after the reaction is completed, the solid-liquid mixture is separated, and the obtained solid is washed, methanol After extraction and drying, the acidic hydroxyl-conjugated microporous polymer is obtained. 2. the acidic hydroxyl conjugated microporous polymer of deep eutectic solvent modification according to claim 1, it is characterized in that, the mol ratio of described deep eutectic solvent and acidic hydroxyl conjugated microporous polymer is 10-12 : 1. 3. the acidic hydroxyl conjugated microporous polymer of deep eutectic solvent modification according to claim 1, is characterized in that, the quality of used 1,3,5-triethynylbenzene and 2,4,6-tribromoaniline The ratio is 0.4-0.5:1; the mass ratio of 1,3,5-triethynylbenzene to copper iodide is 7-9:1. 4. The acidic hydroxyl-conjugated microporous polymer modified by a deep eutectic solvent according to claim 1, wherein the mass ratio of tetrakis(triphenylphosphine) palladium to copper iodide is 5-7:1; The volume ratio of solvent N,N-dimethylformamide to 2,6-diisopropylaniline is 1-2:1. 5. A method for preparing an acidic hydroxyl-conjugated microporous polymer modified by a deep eutectic solvent, which is characterized in that the deep eutectic solvent and the acidic hydroxyl-conjugated microporous polymer are mixed uniformly, and then heated at 70-90°C Heating for 6-10 hours, separating the solid-liquid mixture after the reaction, and washing and drying the obtained solid is the acidic hydroxyl-conjugated microporous polymer modified by the deep eutectic solvent; wherein, the deep eutectic solvent is Ethylene glycol and choline chloride, phenol and choline chloride, urea and choline chloride, or methanesulfonic acid and choline chloride; The acidic hydroxyl conjugated microporous polymer is prepared by the following method: Put 1,3,5-triethynylbenzene, 2,4,6-tribromoaniline, tetrakis(triphenylphosphine)palladium and copper iodide in a reaction vessel, then add N,N-dimethylformamide and 2,6-diisopropylaniline, after excluding the air, introduce circulating argon, the mixture is stirred in an oil bath at 70-90°C for 20-28h, after the reaction is completed, the solid-liquid mixture is separated, and the obtained solid is washed, methanol After extraction and drying, the acidic hydroxyl-conjugated microporous polymer is obtained. 6. The preparation method according to claim 5, characterized in that the molar ratio of the deep eutectic solvent to the acidic hydroxyl-conjugated microporous polymer is 10-12:1. 7. The preparation method according to claim 5, characterized in that the mass ratio of 1,3,5-triethynylbenzene to 2,4,6-tribromoaniline is 0.4-0.5:1; the 1,3 , The mass ratio of 5-triethynylbenzene to copper iodide is 7-9:1; the mass ratio of tetrakis(triphenylphosphine) palladium to copper iodide is 5-7:1; the solvent N,N-dimethyl The volume ratio of formamide to 2,6-diisopropylaniline is 1-2:1.

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