An ester group functionalized pillar [6] arene stationary phase, a capillary gas chromatographic column and a preparation method and application thereof

Abstract

An ester group functionalized pillar [6] arene stationary phase, a capillary gas chromatographic column and a preparation method and application thereof, wherein 1,4-p-benzenediol is used as raw material, 1,4-bis(10-bromodecanoxyl)benzene is obtained through etherification reaction, 1,4-bis(10-bromodecanoxyl)benzene is subjected to cyclization reaction to obtain a bromine functionalized pillar [6] arene, and the bromine functionalized pillar [6] arene is subjected to esterification reaction to obtain an ester group functionalized pillar [6] arene derivative P6A-C10-2OAc, the whole experimental operation process has mild reaction conditions, the raw materials used are cheap, the structure of the stationary phase is novel, the separation effect is obvious, the final product obtained is stable and has good performance, and the ester group functionalized pillar [6] arene stationary phase can accurately separate alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chromatographic analysis, and particularly relates to an ester group functionalized column hexaphenylarene stationary phase, a capillary gas chromatography column and preparation and application thereof. BACKGROUND

[0002] Column hexaphenylarene is a kind of macrocyclic molecule formed by bridging 1,4-dimethoxybenzene units at 2 and 4 positions by methylene. Column hexaphenylarene has a rigid and highly symmetrical columnar structure, an electron-rich macrocyclic cavity, and two ends easy to modify and derive, and thus has been widely used in material chemistry and supramolecular chemistry.

[0003] Capillary gas chromatography has the advantages of high sensitivity, high selectivity, simple operation, fast speed, low cost and the like, and has been widely applied in the fields of petrochemical industry, environmental detection, food safety and biological medicine. In gas chromatographic analysis, for alkylbenzenes, halogenated nitrobenzenes, benzaldehyde isomers and the like with extremely close structural properties, it is difficult to complete separation by means of a traditional stationary phase, which is also a challenging problem in the field of analysis. The selectivity of the stationary phase is a key factor to realize effective separation of target components, and therefore it is of great significance to develop a new type of gas chromatography stationary phase with special selectivity.

[0004] Reference Document 1: Chinese patent document with publication number CN115636737A.

[0005] Reference Document 1 discloses preparation and application of an alkyl functionalized column hexaphenylarene stationary phase. In the invention, the alkyl functionalized column hexaphenylarene serves as a stationary phase of a capillary gas chromatography column, and exhibits good separation performance in separating compounds such as bromobenzaldehyde isomers and dimethylbenzene isomers. However, the separation performance thereof is very poor for halogenated nitrobenzene isomers and methyl naphthalene isomers.

[0006] In view of some deficiencies of the alkyl functionalized column hexaphenylarene in Reference Document 1, we synthesized an ester group functionalized column hexaphenylarene, introduced a polar functional group ester group, and significantly improved the column efficiency. For halogenated nitrobenzene and methyl naphthalene isomers, high-efficiency separation is also achieved on the ester group functionalized column hexaphenylarene stationary phase. SUMMARY

[0007] The present application aims to solve the problem of poor separation performance of alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers in the prior art, and provides an ester group functionalized column hexaphenylarene stationary phase, a capillary gas chromatography column and a preparation method and application thereof.

[0008] In order to solve the above technical problems, the specific scheme adopted by the present application is: an ester group functionalized column hexaphenyl fixed phase for separating alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers, the alkylbenzene isomers including xylene isomers, diethylbenzene isomers and ethyltoluene isomers; the xylene isomers including o-xylene, m-xylene and p-xylene, the diethylbenzene isomers including o-diethylbenzene, m-diethylbenzene and p-diethylbenzene, the ethyltoluene isomers including o-ethyltoluene, m-ethyltoluene and p-ethyltoluene; the halogenated nitrobenzene isomers including chloronitrobenzene and bromonitrobenzene; the chloronitrobenzene isomers including o-chloronitrobenzene, m-chloronitrobenzene and p-chloronitrobenzene, the bromonitrobenzene isomers including o-bromonitrobenzene, m-bromonitrobenzene and p-bromonitrobenzene; the benzaldehyde isomers including bromobenzaldehyde isomers and chlorobenzaldehyde isomers; the bromobenzaldehyde isomers including o-bromobenzaldehyde, m-bromobenzaldehyde and p-bromobenzaldehyde, the chlorobenzaldehyde isomers including o-chlorobenzaldehyde, m-chlorobenzaldehyde and p-chlorobenzaldehyde; the chemical formula of the ester group functionalized column hexaphenyl fixed phase is P6A-C10-2OAc, and the chemical structural formula is:

[0009]

[0010] A preparation method of an ester group functionalized column hexaphenyl fixed phase for separating alkylbenzene, halogenated nitrobenzene and benzaldehyde isomers, comprising the following steps:

[0011] 1) reacting 1,4-p-benzenediol with 1,10-dibromodecane, potassium carbonate, potassium iodide and acetone to obtain compound (I), wherein the compound (I) is 1,4-bis(10-bromodecyloxy)benzene;

[0012] 2) performing cyclization reaction on the compound (I), paraformaldehyde, boron trifluoride ether and chlorocyclohexane, and after post-treatment and purification of the product, an intermediate (II) is obtained, wherein the intermediate (II) is a bromine functionalized column hexaphenyl;

[0013] 3) heating the intermediate (II) with potassium acetate and N,N-dimethylformamide, cooling after the reaction is completed, and after post-treatment and purification of the product, the ester group functionalized column hexaphenyl (III) is obtained;

[0014] As a further optimization of the above technical scheme, the adding amount ratio of 1,4-p-benzenediol, 1,10-dibromodecane, potassium carbonate, potassium iodide and acetone in step 1) is 1g:10.9-11.70g:1.26-2.05g:6.03-7.01g:35-40mL.

[0015] As a further optimization of the above technical solution, in step 2): the reaction temperature is 35℃; the reaction time is 3-4h; the adding amount ratio of compound (I), paraformaldehyde, boron trifluoride ether, chlorocyclohexane and 50mL of solvent is 2.00g:0.33g-0.43g:0.52-0.60g:3.11-3.16g:50mL.

[0016] As a further optimization of the above technical solution, in step 3): the reaction temperature is 80℃; the reaction time is 48h; the adding amount ratio of intermediate (II), potassium acetate and N,N-dimethylformamide is 0.2g:0.3-0.4g:10-20mL.

[0017] As a further optimization of the above technical solution, in step 2): column chromatography is used for purification, and the volume ratio of petroleum ether to dichloromethane in the eluent is 3:1.

[0018] As a further optimization of the above technical solution, in step 3): the heating reaction temperature is 80℃; the reaction time is 48h.

[0019] As a further optimization of the above technical solution, in step 3): column chromatography is used for purification, and the volume ratio of dichloromethane to methanol in the eluent is 40:1.

[0020] A capillary gas chromatography column prepared from the above ester-functionalized column hexaarylborate stationary phase.

[0021] As a further optimization of the above technical solution, the capillary gas chromatography column is prepared by static coating.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The ester-functionalized column hexaarylborate stationary phase of the present application can accurately separate alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers, because the ester-functionalized column hexaarylborate has a large cavity size and a polar functional group, the molecular structure size of alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers matches the cavity, and they can freely enter the cavity. Therefore, there is multiple molecular recognition between them, in addition to common non-covalent weak interactions (van der Waals force, hydrogen bond, dipole-dipole and pi-pi interaction), there is also a special shape matching effect, so the ester-functionalized column hexaarylborate has excellent chromatographic separation performance for alkylbenzene isomers, halogenated nitrobenzene isomers and benzaldehyde isomers. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1is the reaction route map of the ester functionalized pillar hexaphenyls P6A-C10-2OAc prepared by the present application using 1,4-hydroquinone as raw material;

[0025] Figure 2 is the thermogravimetric analysis map of the ester functionalized pillar hexaphenyls stationary phase;

[0026] Figure 3 is the column efficiency (Golay curve) map of the capillary gas chromatography column prepared by the present application using naphthalene as probe compound at 120℃;

[0027] Figure 4 is the separation of different polar and different types of alkylbenzene isomers by the capillary gas chromatography column prepared by the present application, including dimethylbenzene isomers: o-xylene, m-xylene, p-xylene, diethylbenzene isomers: o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, ethyltoluene isomers: o-ethyltoluene, m-ethyltoluene, p-ethyltoluene;

[0028] Figure 5 is the separation of different polar and different types of naphthalene isomers by the capillary gas chromatography column prepared by the present application, including 2-methylnaphthalene, 1-methylnaphthalene, and dimethylnaphthalene isomers: 2,6-dimethylnaphthalene, 1,3-dimethylnaphthalene, 2,3-dimethylnaphthalene, 1,2-dimethylnaphthalene;

[0029] Figure 6 is the separation of different polar and different types of halogenated benzene isomers by the capillary gas chromatography column prepared by the present application, including dibromobenzene isomers: o-dibromobenzene, m-dibromobenzene, p-dibromobenzene, trichlorobenzene isomers: o-trichlorobenzene, m-trichlorobenzene, p-trichlorobenzene, chloronitrobenzene isomers: o-chloronitrobenzene, m-chloronitrobenzene, p-chloronitrobenzene, bromonitrobenzene isomers: o-bromonitrobenzene, m-bromonitrobenzene, p-bromonitrobenzene;

[0030] Figure 7 is the separation of benzaldehyde isomers by the capillary gas chromatography column prepared by the present application, including bromobenzaldehyde isomers: o-bromobenzaldehyde, m-bromobenzaldehyde, p-bromobenzaldehyde, chlorobenzaldehyde isomers: o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, dichlorobenzaldehyde isomers: 2,4-dichlorobenzaldehyde, 2,5-dichlorobenzaldehyde, 2,4-dichlorobenzaldehyde, 2,3-dichlorobenzaldehyde, 2,6-dichlorobenzaldehyde, 3,4-dichlorobenzaldehyde, nitrobenzaldehyde isomers: o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde;

[0031] Figure 8isomers of phenol including dimethyl phenol isomers: 2,6-dimethyl phenol, 2,5-dimethyl phenol, 2,3-dimethyl phenol, 3,5-dimethyl phenol, 3,4-dimethyl phenol, dihydroxybenzene isomers: catechol, resorcinol, hydroquinone;

[0032] Figure 9 is a comparison chart of separation of 20-component complex mixture samples of different polarities and different types by the capillary gas chromatographic column prepared in the present application and by using commercial column HP-5, commercial column HP-35 and commercial column PEG-20M;

[0033] Figure 10 is a comparison chart of separation of alkyl benzene isomers by the capillary gas chromatographic column prepared in the present application and by using commercial column HP-5, HP-35 and PEG-20M;

[0034] Figure 11 is a comparison chart of separation of halogenated nitrobenzene isomers by the capillary gas chromatographic column prepared in the present application and by using commercial column HP-5, HP-35 and PEG-20M;

[0035] Figure 12 is a comparison chart of separation of benzaldehyde isomers by the capillary gas chromatographic column prepared in the present application and by using commercial column HP-5, HP-35 and PEG-20M;

[0036] Figure 13 is a scanning electron microscope (SEM) chart of the capillary gas chromatographic column prepared in the present application;

[0037] Figure 14 is a comparison chart of separation of alkyl benzene isomers by the capillary gas chromatographic column prepared in the present application and by using ester group functionalized column five;

[0038] Figure 15 is a comparison chart of separation of halogenated nitrobenzene isomers by the capillary gas chromatographic column prepared in the present application and by using alkyl group functionalized column six;

[0039] Figure 16 is a comparison chart of separation of different substituted naphthalene isomers by the capillary gas chromatographic column prepared in the present application and by using alkyl group functionalized column six;

[0040] Figure 17 is a result of determination of isomer impurities present in commercial reagent products by the capillary gas chromatographic column prepared in Example 4 of the present application. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0042] The present application provides an ester group functionalized pillar [6] arene stationary phase and a preparation method thereof. The structural formula of the ester group functionalized pillar [6] arene stationary phase is as follows:

[0043]

[0044] The preparation method of the ester group functionalized pillar [6] arene stationary phase comprises the following steps:

[0045] 1) 1,4-hydroquinone is reacted with 1,10-dibromodecane, potassium carbonate, potassium iodide and acetone to obtain compound (I), and the compound (I) is 1,4-bis (10-bromodecanoxyl) benzene;

[0046] 2) Compound (I), paraformaldehyde, boron trifluoride ether and chlorocyclohexane are subjected to a cyclization reaction, and after post-treatment and purification, an intermediate (II) is obtained, and the intermediate (II) is a bromine functionalized pillar [6] arene;

[0047] 3) The intermediate (II) is heated and reacted with potassium acetate and N, N-dimethylformamide, and after the reaction is completed, the temperature is lowered, and after post-treatment and purification, the ester group functionalized pillar [6] arene (III) is obtained.

[0048] The reaction formula is as shown in Figure 1

[0049]

[0050] Example 1

[0051] (1) 2.00 g (18.16 mmol) of 1,4-hydroquinone, 21.80 g (72.65 mmol) of 1,10-dibromodecane, 2.51 g (18.16 mmol) of potassium carbonate and 12.06 g (72.65 mmol) of potassium iodide are added into 80 mL of acetone, and the mixture is reacted at 65°C for 72 h, cooled, filtered, and the filter cake is washed with 100 mL of dichloromethane. The filtrate is collected and evaporated to dryness to obtain 24.25 g of brown viscous crude product, which is purified by column chromatography, and the eluent is petroleum ether: dichloromethane = 5:1 (V:V) to obtain 2.50 g of compound (I), and the structural formula of the compound (I) is as follows:

[0052] The characterization data are as follows: 1 ​H NMR (400MHz, CDCl3) δ: 6.84 (s, 4H), 3.92 (t, J = 6.6Hz, 4H), 3.43 (t, J = 7.0Hz, 4H), 2.01-1.83 (m, 4H), 1.83-1.68 (m, 4H), 1.58-1.15 (m, 24H). IR (KBr, cm -1 ): 2933.37(CH2), 2918.83(CH2), 2850.71(CH2), 1508.01(C=C), 1473.71(C=C), 1461.43(C=C), 1216.81(COC), 1036.54(COC), 643.84(C-Br).

[0053] (2) 2.00 g (3.65 mmol) of compound (I), 0.33 g (10.94 mmol) of paraformaldehyde, 0.52 g (3.65 mmol) of boron trifluoride etherate and 50 mL of chlorocyclohexane were added to a 250 mL single-necked flask and reacted at 35°C for 4 h. 50 mL of deionized water was added, and the organic phase was washed with 50 mL of saturated brine, dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness to obtain 2.40 g of a green crude product, which was purified by column chromatography using petroleum ether: dichloromethane = 3:1 (V:V) as the eluent to obtain 0.26 g of intermediate (II) as a white solid. The structural formula of intermediate (II) is:

[0054] Its characterization data are: 1 H NMR (400MHz, CDCl3) δ6.70 (s, 12H), 3.77 (s, 24H), 3.75 (s, 12H), 3.40 (t, J = 6.6Hz, 24H), 1. 83(q,J=7.0Hz,24H),1.71(t,J=7.5Hz,24H),1.47–1.38(m,44H),1.31(m,100H).IR(KBr,cm -1 ): 2922.39(CH2), 2851.37(CH2), 1500.57(C=C), 1473.28(C=C), 1435.70(C=C), 1207.84(COC), 1045.18(COC), 644.74(C-Br).

[0055] (3) Take 0.20 g (59.72 μmol) of the intermediate (II), 0.301 g (1.43 mmol) of potassium acetate and 10 mL of N, N-dimethylformamide obtained in step (2) into a 50 mL single-necked flask, and react at 80°C for 48 h, then cool to room temperature, add 30 mL of deionized water to precipitate a light yellow solid of 0.18 g, and purify by column chromatography with petroleum ether: dichloromethane = 1:1 (V:V = 1:1) as the eluent to obtain the final product (III), which is an ester group functionalized p-quinquephenyl stationary phase, and has the chemical formula of P6A-C10-2OAc and is a light yellow solid of 0.10 g. The structural formula of the final product (III) is

[0056] The characterization data thereof are as follows: 1 H NMR (300 MHz, CDCl3) δ 6.70 (s, 12H), 4.05 (t, J = 6.6 Hz, 24H), 3.75 (m, 36H), 2.04 (s, 36H), 1.68 (s, 48H), 1.30 (s, 120H). IR (KBr, cm -1 ): 2923.29 (CH2), 2851.77 (CH2), 1737.23 (C=C), 1501.55 (C=C), 1473.28 (C=C), 1237.37 (C-O-C), 1209.84 (C-O-C).

[0057] The present application uses 1, 4-hydroquinone as a raw material, first obtains compound (I) through etherification reaction, then obtains intermediate (II) through cyclization reaction of compound (I), and then obtains ester group functionalized p-quinquephenyl derivative (III) (such as Figure 1 ) from intermediate (II) through esterification reaction. The whole experimental operation process has mild reaction conditions, the raw materials used are cheap, the structure of the stationary phase is novel, the separation effect is obvious, and the final product obtained is stable and has good performance.

[0058] As shown in Figure 2 , P6A-C10-2OAc has good thermal stability as a stationary phase of a capillary gas chromatography column, and the thermal stability is as high as 300°C.

[0059] Example 2

[0060] (1) Put 2.50 g of 1, 4-hydroquinone, 27.25 g of 1, 10-dibromodecane, 3.14 g of potassium carbonate and 15.08 g of potassium iodide into 85 mL of acetone, react at 65°C for 72 h, cool, filter, and wash the filter cake with dichloromethane. Collect the filtrate and evaporate to dryness to obtain a yellow sticky crude product, purify by column chromatography with petroleum ether: dichloromethane = 5:1 (V:V) as the eluent to obtain compound (I): 2.80 g;

[0061] (2) The resulting 2.50 g (1.82 mmol) of compound (I), 0.16 g (5.47 mmol) of paraformaldehyde, 0.26 g (1.82 mmol) of boron trifluoride etherate and 60 mL of chlorocyclohexane were added to a 100 mL single-necked flask and reacted at 35°C for 4 h. 40 mL of deionized water was added, the organic phase was washed with 60 mL of saturated brine, dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness to obtain 2.9 g of green crude product, which was purified by column chromatography using petroleum ether: dichloromethane = 3: 1 (V:V) as the eluent to obtain intermediate (II) as a white solid: 0.35 g.

[0062] (3) The resulting 0.3 g (89.59 μmol) of intermediate (II) in step (2), 0.21 g (2.15 mmol) of potassium acetate and 15 mL of N,N-dimethylformamide were added to a 50 mL single-necked flask and reacted at 80°C for 48 h. The temperature was lowered to room temperature, and 40 mL of deionized water was added to precipitate 0.26 g of yellowish solid, which was the final product (III). The final product (III) was an ester-functionalized columnar pentaphene stationary phase with the chemical formula P6A-C10-20Ac and was a yellowish solid 0.15 g.

[0063] Example 3

[0064] (1) 3.00 g of 1,4-hydroquinone, 32.70 g of 1,10-dibromodecane, 3.37 g of potassium carbonate and 18.09 g of potassium iodide were added to 100 mL of acetone and reacted at 65°C for 72 h. The temperature was lowered, and the filter cake was washed with dichloromethane. The filtrate was collected and evaporated to dryness to obtain a yellowish viscous crude product, which was purified by column chromatography using petroleum ether: dichloromethane = 5: 1 (V:V) as the eluent to obtain compound (I): 3.6 g.

[0065] (2) The resulting 2.00 g (3.65 mmol) of compound (I), 0.33 g (10.94 mmol) of paraformaldehyde, 0.52 g (3.65 mmol) of boron trifluoride etherate and 50 mL of chlorocyclohexane were added to a 100 mL single-necked flask and reacted at 35°C for 4 h. 50 mL of deionized water was added, the organic phase was washed with 50 mL of saturated brine, dried over anhydrous magnesium sulfate, filtered, and evaporated to dryness to obtain 1.2 g of green crude product, which was purified by column chromatography using petroleum ether: dichloromethane = 3: 1 (V:V) as the eluent to obtain intermediate (II) as a white solid: 0.26 g.

[0066] (3) Put 0.25 g (74.66 μmol) of the intermediate (II), 0.18 g (1.79 mmol) of potassium acetate and 12 mL of N, N-dimethylformamide obtained in step (2) into a 50 mL single-necked flask, react at 80°C for 48 h, reduce to room temperature, add 35 mL of deionized water to precipitate 0.2 g of light yellow solid, and obtain the final product (III), which is an ester group functionalized column hexa-aryl hydrocarbon stationary phase, and the final product (III) is a light yellow solid 0.13 g. The structural formula of the final product (III) is

[0067] Example 4

[0068] The present application also provides a capillary chromatographic column prepared by using the ester group functionalized column hexa-aryl hydrocarbon stationary phase provided by the present application, and specifically, the static method can be used for coating preparation.

[0069] (1) Cut a quartz capillary tube with a length of 5 m and an inner diameter of 250 μm, first wash it with dichloromethane for 10 min, and then age it at 200°C for 2-3 h under nitrogen protection, so that the impurities in the capillary column flow out with nitrogen at high temperature.

[0070] (2) Weigh 1.31 g of ground NaCl powder, put it into 10 mL of anhydrous methanol solution, and stir vigorously for 45 min to obtain a saturated sodium chloride methanol solution. Take 6 mL of the saturated solution and add it to 8 mL of a vigorously stirred chloroform solution, then add 0.6 mL of anhydrous methanol solution, stir for 5 min, and then add 8 mL of chloroform solution and continue stirring for 2 min to obtain a saturated colloidal solution.

[0071] (3) Under a nitrogen pressure of 0.01-0.02 MPa, press the saturated colloidal solution into the capillary tube. Then blow the solution in the column with nitrogen, and recrystallize at 200°C for 3 h under nitrogen protection to complete the roughening of the inner surface of the capillary column.

[0072] (4) In this experiment, the static method is used to prepare the column, the P6A-C10-2OAc is dissolved in dichloromethane solution to prepare a stationary phase solution with a concentration of 0.3% (w / v), and ultrasonic treatment is performed for 5 min to remove the gas bubbles in the stationary phase solution.

[0073] (5) Push the stationary phase solution into the capillary chromatographic column with a syringe until the stationary phase solution fills the entire chromatographic column, then seal one end of the capillary tube and connect the other end to a vacuum system, and slowly evaporate the solvent in a 40°C constant temperature water bath, so that the stationary phase can be uniformly dispersed on the inner wall of the capillary column.

[0074] (6) The coated capillary chromatographic column is aged by using a programmed temperature method under nitrogen protection: 40℃ is kept for 30 min, then increased to 180℃ at a rate of 1℃ / min, and kept for 7 h, that is, the aging of the chromatographic column is completed, and the capillary gas chromatographic column is obtained.

[0075] The capillary gas chromatographic column prepared by using P6A-C10-2OAc as a chromatographic separation stationary phase for the first time has high column efficiency.

[0076] The ester functionalized pillar [6] arene derivative P6A-C10-2OAc prepared in the application has a unique structure, in which the column ring, the alkyl chain and the ester group make the stationary phase have good effects in practical application, and have various different weak interaction forces with different analytes, including van der Waals force, hydrogen bond, pi-pi interaction, dipole-dipole interaction and CH-pi interaction, so that the P6A-C10-2OAc column has good separation effect.

[0077] The P6A-C10-2OAc is used as a stationary phase of a capillary gas chromatographic column for the first time, and the P6A-C10-2OAc perfectly combines the structural characteristics of pillar [6] arene and the advantages of ester functionalization, so that this new type of material as a stationary phase of a capillary gas chromatographic column becomes a reality, and provides more separation materials for the research of chromatographic separation.

[0078] The ester functionalized pillar [6] arene derivative P6A-C10-2OAc prepared in the application combines the unique molecular recognition ability of pillar arene and the advantages of alkyl and ester functionalization, and mutually compensates for the respective shortcomings, in which the rigid, freely adjustable and π-electron-rich column ring of the pillar arene has good flexibility and has certain induced fitting ability, so as to recognize guest molecules, but has the shortcomings of high melting point and poor film-forming property; the advantages of easy functionalization of the pillar arene make it possible to introduce long alkyl chains and ester groups to improve the properties of the pillar arene as a gas chromatographic stationary phase, the introduction of long alkyl chains can reduce the melting point of the pillar arene and improve the film-forming property of the pillar arene; the substituted ester group can improve the selectivity of the pillar arene for target compounds while ensuring the stability of the pillar arene.

[0079] <Separation effect>

[0080] In order to analyze the separation effect of the capillary chromatographic column, the following experiments are carried out on the capillary chromatographic column provided in the application:

[0081] (1) As Figure 3As shown, the Golay curve of naphthalene was determined using the capillary gas chromatographic column prepared in Example 4. The specific chromatographic conditions were: column box temperature 120° C., carrier gas: nitrogen, carrier gas flow rate: 0.4 mL / min, and minimum theoretical plate height: 0.31 mm.

[0082] (2) Separation of alkylbenzene isomers:

[0083] Three different alkylbenzene isomers were selected as the separated analytes ( Figure 4 ), including xylene isomers: o-xylene, m-xylene, and p-xylene; diethylbenzene isomers: o-diethylbenzene, m-diethylbenzene, and p-diethylbenzene; and ethyltoluenes: o-ethyltoluene, m-ethyltoluene, and p-ethyltoluene. Chromatographic separation conditions: maintaining at 40°C for 1 minute, heating to 160°C at a rate of 10°C / min, and using a carrier gas flow rate of 0.6 mL / min. The capillary chromatographic column prepared by the present invention is capable of separating the various components of alkylbenzene isomers.

[0084] (3) Separation of substituted naphthalene isomers:

[0085] Two different naphthalene isomers were selected as the separated analytes ( Figure 5 ), including methylnaphthalene isomers: 2-methylnaphthalene, 1-methylnaphthalene, and dimethylnaphthalene isomers: 2,6-dimethylnaphthalene, 1,3-dimethylnaphthalene, 2,3-dimethylnaphthalene, and 1,2-dimethylnaphthalene. Chromatographic separation conditions: maintaining at 40°C for 1 minute, heating to 160°C at a rate of 10°C / min, and using a carrier gas flow rate of 0.6 mL / min. The capillary chromatographic column prepared by the present invention is capable of separating the various components of substituted naphthalene isomers.

[0086] (4) Separation of substituted halogenated benzene isomers:

[0087] Four different types of halogenated benzene isomers with different polarities were selected as the separated analytes ( Figure 6 ), including dibromobenzene isomers: o-dibromobenzene, m-dibromobenzene, p-dibromobenzene; trichlorobenzene isomers: o-trichlorobenzene, m-trichlorobenzene, p-trichlorobenzene; chloronitrobenzene isomers: o-chloronitrobenzene, m-chloronitrobenzene, p-chloronitrobenzene; and bromonitrobenzene isomers: o-bromonitrobenzene, m-bromonitrobenzene, p-bromonitrobenzene. Chromatographic separation conditions: maintaining at 40°C for 1 minute, heating at a rate of 10°C / min to 160°C, and using a carrier gas flow rate of 0.6 mL / min. The present invention is capable of separating substituted halogenated benzene isomers.

[0088] (5) Separation of benzaldehyde isomers:

[0089] Four different types of benzaldehyde isomers with different polarities were selected as the separated analytes ( Figure 7) including bromobenzaldehyde isomers: o-bromobenzaldehyde, m-bromobenzaldehyde, p-bromobenzaldehyde, chlorobenzaldehyde isomers: o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, dichlorobenzaldehyde isomers: 2,4-dichlorobenzaldehyde, 2,5-dichlorobenzaldehyde, 2,4-dichlorobenzaldehyde, 2,3-dichlorobenzaldehyde, 2,6-dichlorobenzaldehyde, 3,4-dichlorobenzaldehyde, nitrobenzaldehyde isomers: o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde. Chromatographic separation conditions: 40°C for 1 min, temperature rising rate of 10°C / min to 160°C, carrier gas flow rate of 0.6 mL / min. The substituted benzaldehyde isomers can be separated by the present application.

[0090] (6) Separation of phenol isomers:

[0091] Two different types of phenol isomers with different polarity were selected as separation analytes Figure 8 ) including dimethylphenol isomers: 2,6-dimethylphenol, 2,5-dimethylphenol, 2,3-dimethylphenol, 3,5-dimethylphenol, 3,4-dimethylphenol, diphenol isomers: o-diphenol, m-diphenol, p-diphenol. Chromatographic separation conditions: 40°C for 1 min, temperature rising rate of 10°C / min to 160°C, carrier gas flow rate of 0.6 mL / min. The substituted phenol isomers can be separated by the present application.

[0092] (7) Separation of 20-component complex mixture

[0093] A 20-component complex mixture was selected as an analyte, and the above sample was separated by using the capillary gas chromatographic column prepared in the example. Chromatographic separation conditions: 40°C for 1 min, temperature rising rate of 10°C / min to 160°C, carrier gas flow rate of 0.6 mL / min.

[0094] Figure 9 is a chromatogram of the separation of a 20-component complex mixture by a capillary gas chromatographic column, wherein 1: 4-ethyltoluene, 2: 1,2,4-trimethylbenzene, 3: n-hexanol, 4: 1,4-diethylbenzene, 5: octanone, 6: 1,4-dichlorobenzene, 7: monosubstituted bromoheptane, 8: dodecane, 9: n-octanol, 10: p-methylbenzaldehyde, 11: tridecane, 12: 1,3-dibromobenzene, 13: m-chlorobenzaldehyde, 14: methyl heptanoate, 15: 2,3-dimethyl aniline, 16: 2-methylnaphthalene, 17: 2-bromoaniline, 18: 2,3-dimethylphenol, 19: hexadecane, 20: o-bromonitrobenzene. The separation effect is better than that of polysiloxane commercial columns HP-5, HP-35 and PEG-20M, as shown in Figure 9As shown in the figure, the capillary gas chromatographic column prepared by the example has good separation effect on 20-component complex mixture, the types of analytes are more and the polarity range is wider, which shows that the P6A-C10-2OAc stationary phase is suitable for separating complex mixture and the separation effect is better than that of the commercial columns HP-5, HP-35 and PEG-20M.

[0095] (8) Separation of alkylbenzene isomers

[0096] Three alkylbenzene isomers are selected as analytes, including xylene isomers: o-xylene, m-xylene, p-xylene, diethylbenzene isomers: o-diethylbenzene, m-diethylbenzene, p-diethylbenzene, ethyltoluene isomers: o-ethyltoluene, m-ethyltoluene, p-ethyltoluene. The chromatographic separation conditions are: 40℃ for 1 min, the temperature is raised to 160℃ at a rate of 10℃ / min, the carrier gas flow rate is 0.6 mL / min, and the separation results are shown in the figure. Figure 10 As shown in the figure, the P6A-C10-2OAc column prepared by the application can separate three alkylbenzene isomers, and the effect is better than that of the commercial columns HP-5, HP-35 and PEG-20M.

[0097] (9) Separation of halogenated nitrobenzene isomers

[0098] Two halogenated nitrobenzene isomers are selected as analytes, including chloronitrobenzene isomers: o-chloronitrobenzene, m-chloronitrobenzene, p-chloronitrobenzene, bromonitrobenzene isomers: o-bromonitrobenzene, m-bromonitrobenzene, p-bromonitrobenzene. The capillary gas chromatographic column prepared by the example 4 of the application is used to separate the above samples. The chromatographic separation conditions are: 40℃ for 1 min, the temperature is raised to 160℃ at a rate of 10℃ / min, the carrier gas flow rate is 0.6 mL / min, and the separation results are shown in the figure. Figure 11 As shown in the figure, the P6A-C10-2OAc column prepared by the application can separate halogenated nitrobenzene isomers, and the effect is better than that of the commercial columns HP-5, HP-35 and PEG-20M.

[0099] (10) Separation of benzaldehyde isomers

[0100] Two benzaldehyde isomers are selected as analytes, including bromobenzaldehyde isomers: o-bromobenzaldehyde, m-bromobenzaldehyde, p-bromobenzaldehyde, chlorobenzaldehyde isomers: o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde. The capillary gas chromatographic column prepared by the example 4 of the application is used to separate the above samples. The chromatographic separation conditions are: 40℃ for 1 min, the temperature is raised to 160℃ at a rate of 10℃ / min, the carrier gas flow rate is 0.6 mL / min, and the separation results are shown in the figure. Figure 12 As shown in the figure, the P6A-C10-2OAc column prepared by the application can separate halogenated benzene isomers, and the effect is better than that of the commercial columns HP-5, HP-35 and PEG-20M.

[0101] Good film-forming properties

[0102] Figure 13 This is a scanning electron microscope (SEM) image of the capillary gas chromatography column prepared in the present invention, showing the good film-forming property of the P6A-C10-2OAc stationary phase.

[0103] Comparative Example 1

[0104] Alkylbenzene isomers were separated using the capillary gas chromatography column prepared in Example 4 and a capillary gas chromatography column prepared using an ester-functionalized pentaaromatic stationary phase.

[0105] Three alkylbenzene isomers were selected as analytes: o-xylene, m-xylene, and p-xylene; o-diethylbenzene, m-diethylbenzene, and p-diethylbenzene; and o-ethyltoluene, m-ethyltoluene, and p-ethyltoluene. Chromatographic separation conditions were: 40°C for 1 minute, then a temperature ramp of 10°C / min to 160°C, with a carrier gas flow rate of 0.6 mL / min.

[0106] Depend on Figure 14 It can be seen that the capillary gas chromatography column prepared in Example 4 can separate the three alkylbenzene isomers, but the capillary gas chromatography column prepared with the ester-functionalized pentaaromatic stationary phase cannot separate the alkylbenzene isomers. This is because the cavity size of the ester-functionalized pentaaromatic stationary phase is limited. The halogenated aniline isomers cannot enter the cavity, and the interaction site between them is outside the pillar aromatic hydrocarbon skeleton. The types of interaction forces mainly include van der Waals forces, hydrogen bonds, π-π and other molecular recognition effects. Since the cavity of the ester-functionalized pillar pentaaromatic hydrocarbon cannot match the molecular size of the halogenated aniline isomers, there is no special shape matching effect between them. The ester-functionalized pillar pentaaromatic hydrocarbon cannot effectively separate the alkylbenzene isomers, while the ester-functionalized pillar hexaaromatic hydrocarbon has a larger cavity size. The molecular structure size of alkylbenzene isomers matches its cavity and can freely enter its cavity.

[0107] Comparative Example 2

[0108] The capillary gas chromatography column prepared in Example 4 and the capillary gas chromatography column prepared using the alkyl-functionalized hexaaromatic stationary phase were used to separate the halogenated nitrobenzene isomers.

[0109] Halonitrobenzenes were selected as analytes, including the bromonitrobenzene isomers: o-bromonitrobenzene, m-bromonitrobenzene, and p-bromonitrobenzene; and the chloronitrobenzenes: o-chloronitrobenzene, m-chloronitrobenzene, and p-chloronitrobenzene. Chromatographic separation conditions were: 40°C for 1 minute, then a temperature ramp of 10°C / min to 160°C, with a carrier gas flow rate of 0.6 mL / min.

[0110] Depend on Figure 15 It can be seen that the capillary gas chromatography column prepared in Example 4 can separate halonitrobenzene isomers, but the capillary gas chromatography column prepared with an alkyl-functionalized column hexaarene stationary phase cannot separate halonitrobenzene isomers. This is because the ester-functionalized column hexaarene has a polar functional group, the ester group, which interacts with the halonitrobenzene isomers through π-π, dipole-dipole, and hydrogen bonding, thereby achieving efficient separation of halonitrobenzene isomers. However, the alkylated column hexaarene does not have a polar functional group, and therefore has a poor separation effect on halonitrobenzene isomers.

[0111] Comparative Example 3

[0112] The capillary gas chromatography column prepared in Example 4 and the capillary gas chromatography column prepared using the alkyl-functionalized hexaaromatic stationary phase were used to separate naphthalene isomers.

[0113] Two different naphthalene isomers were selected as analytes, including methylnaphthalene isomers: 1-methylnaphthalene, 2-methylnaphthalene isomers, dimethylnaphthalene isomers, and 2,6-dimethylnaphthalene: 1,3-dimethylnaphthalene, 2,3-dimethylnaphthalene, and 1,2-dimethylnaphthalene isomers. Chromatographic separation conditions were: 40°C for 1 minute, then heated to 160°C at a rate of 10°C / min, with a carrier gas flow rate of 0.6 mL / min.

[0114] Depend on Figure 16 It can be seen that the capillary gas chromatographic column prepared in Example 4 can separate naphthalene isomers, but the capillary gas chromatographic column prepared by the alkyl-functionalized column hexaaromatic stationary phase cannot separate naphthalene isomers. This is because the ester-functionalized column hexaaromatic has a polar functional group ester group, and there is CH-π,π-π, dipole-dipole, hydrogen bond interaction between the column hexaaromatic and the naphthalene isomers, thereby achieving efficient separation of naphthalene isomers, and the alkylated column hexaaromatic does not have a polar functional group, so the separation effect of naphthalene isomers is poor.

[0115] Determination of isomeric impurities in chemical products

[0116] Seven commercial reagent products were selected, including geraniol, trans-dimethylnaphthalene, cis-dimethylnaphthalene, isopropylbenzene, propylbenzene, 2,4-dimethylaniline and o-xylene, and the isomeric impurities present in the commercial reagent products were determined using the capillary gas chromatography column prepared in Example 4.

[0117] From the bottom Figure 17 The capillary gas chromatography column prepared in Example 4 showed consistent purity with the label purity of the commercial reagent product. This result indicates that capillary gas chromatography columns prepared from ester-functionalized hexaaromatic hydrocarbons have great potential for application in the purity analysis of actual samples or the analysis of the content of isomeric impurities.

[0118]

[0119] It should be noted that the above embodiments are only used to illustrate the present invention, but the present invention is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention fall within the scope of protection of the present invention.

Claims

1. An ester-functionalized pillar[6]arene stationary phase, characterized in that: the ester-functionalized pillar[6]arene stationary phase is capable of separating alkylbenzene isomers, halonitrobenzene isomers and benzaldehyde isomers; the alkylbenzene isomers include xylene isomers, diethylbenzene isomers and ethyltoluene isomers; the halonitrobenzene isomers include chloronitrobenzene isomers and bromonitrobenzene isomers; the benzaldehyde isomers include bromobenzaldehyde isomers and chlorobenzaldehyde isomers; the ester-functionalized pillar[6]arene stationary phase has a chemical formula of P6A-C10-2OAc and a chemical structure formula of: 。 2. The method for preparing the ester-functionalized hexaaromatic column stationary phase according to claim 1, wherein: comprising the following steps: 1) reacting 1,4-hydroquinone with 1,10-dibromodecane, potassium carbonate, potassium iodide and acetone to obtain compound (I), wherein the compound (I) is 1,4-bis(10-bromodecanoyl)benzene; 2) performing a cyclization reaction of the compound (I), paraformaldehyde, boron trifluoride etherate and chlorocyclohexane, and after post-treatment and purification, obtaining an intermediate (II), wherein the intermediate (II) is a bromo-functionalized pillar[6]arene; 3) performing a heating reaction of the intermediate (II), potassium acetate and N,N-dimethylformamide, and after cooling, post-treatment and purification, obtaining the ester-functionalized pillar[6]arene.

3. The method of claim 2, wherein the ester-functionalized pillar[6]arene stationary phase is prepared by the reaction of a pillar[6]arene with a carboxylic acid. 3 In step 1), the reaction temperature is 65°C; the reaction time is 72 h; and the addition amount ratio of 1, 4-hydroquinone, 1,10-dibromodecane, potassium carbonate, potassium iodide and acetone is 1 g: 10.9-11.70 g: 1.26-2.05 g: 6.03-7.01 g: 40-45 mL.

4. The method of claim 2, wherein the ester-functionalized pillar[6]arene stationary phase is prepared by the reaction of a pillar[6]arene with a carboxylic acid. 5 In step 2), the reaction temperature is 35°C; and the reaction time is 3-4 h.

5. The method of claim 2, wherein the ester-functionalized pillar[6]arene stationary phase is prepared by the reaction of a pillar[6]arene with an ester-functionalized reagent. In step 3), the reaction temperature is 80°C; the reaction time is 48 h; and the addition amount ratio of the intermediate (II), potassium acetate and N,N-dimethylformamide is 0.2 g: 0.3-0.4 g: 10-20 mL.

6. The method for preparing an ester-functionalized column hexaaromatic stationary phase according to claim 2, wherein: In step 2), column chromatography is used for purification, and the volume ratio of petroleum ether to dichloromethane in the eluent is 3:

1.

7. The method for preparing an ester-functionalized hexaaromatic column stationary phase according to claim 2, wherein: In step 3), column chromatography is used for purification, and the volume ratio of dichloromethane to methanol in the eluent is 40:

1.

8. A capillary gas chromatography column characterized in that, The capillary gas chromatography column is prepared from the ester-functionalized pillar[6]arene stationary phase according to claim 1.

9. A capillary gas chromatographic column as defined in claim 8, characterized in that The capillary gas chromatography column is prepared by a static coating method.

10. Use of a capillary gas chromatography column as claimed in claim 9, characterized in that: The capillary gas chromatography column is capable of separating alkylbenzene isomers, halonitrobenzene isomers and benzaldehyde isomers; the alkylbenzene isomers include xylene isomers, diethylbenzene isomers and ethyltoluene isomers; the xylene isomers include o-xylene, m-xylene and p-xylene; the diethylbenzene isomers include o-diethylbenzene, m-diethylbenzene and p-diethylbenzene; and the ethyltoluene isomers include o-ethyltoluene, m-ethyltoluene and p-ethyltoluene; the halonitrobenzene isomers include chloronitrobenzene and bromonitrobenzene; the chloronitrobenzene isomers include o-chloronitrobenzene, m-chloronitrobenzene and p-chloronitrobenzene; and the bromonitrobenzene isomers include o-bromonitrobenzene, m-bromonitrobenzene and p-bromonitrobenzene; The benzaldehyde isomers include bromobenzaldehyde isomers and chlorobenzaldehyde isomers; the bromobenzaldehyde isomers include o-bromobenzaldehyde, m-bromobenzaldehyde and p-bromobenzaldehyde, and the chlorobenzaldehyde isomers include o-chlorobenzaldehyde, m-chlorobenzaldehyde and p-chlorobenzaldehyde. The benzaldehyde isomers include bromobenzaldehyde isomers and chlorobenzaldehyde isomers; the bromobenzaldehyde isomers include o-bromobenzaldehyde, m-bromobenzaldehyde and p-bromobenzaldehyde, and the chlorobenzaldehyde isomers include o-chlorobenzaldehyde, m-chlorobenzaldehyde and p-chlorobenzaldehyde.

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