Naphthalimide organogelator and preparation method and application thereof
阅读说明：本技术 一种萘酰肼类有机凝胶因子及其制备方法与应用 (Naphthalimide organogelator and preparation method and application thereof ) 是由 周义锋 王俊俊 陈鑫 郭春梅 王妍 于 2021-07-13 设计创作，主要内容包括：本发明涉及一种萘酰肼类有机凝胶因子及其制备方法与应用,萘酰肼类有机凝胶因子的结构式如下所示：其中,n＝4-18；通过将对烷氧基苯甲酸与缩合剂配制成混合溶液,再加入萘甲酰肼并进行缩合反应,经分离纯化后即可制备得到；将上述有机凝胶因子与有机溶剂混合,并在密封状态下加热溶解,冷却后,即可得到具有氟离子响应性的有机凝胶。与现有技术相比,本发明制备工艺简单,反应条件温和,对甲醇、乙醇等多种有机溶剂中均表现出良好的凝胶能力；并在凝胶状态下对氟离子具有显著的特异性响应,在氟离子检测方面表现出明显的优势。(The invention relates to a naphthalimide organogelator and a preparation method and application thereof, wherein the structural formula of the naphthalimide organogelator is as follows: wherein n is 4-18; preparing p-alkoxy benzoic acid and a condensing agent into a mixed solution, adding naphthoyl hydrazine, carrying out condensation reaction, and separating and purifying to obtain the p-alkoxy benzoic acid-naphthoyl hydrazine derivative; mixing the organogelator and organic solvent, heating and dissolving in sealed condition, and coolingThen, the organogel with the response of the fluorinion can be obtained. Compared with the prior art, the preparation method has the advantages of simple preparation process, mild reaction conditions and good gelling capability in various organic solvents such as methanol, ethanol and the like; and has remarkable specific response to the fluorine ions in the gel state, and shows obvious advantages in the aspect of fluorine ion detection.)
1. The naphthalimide organogelator is characterized in that the structural formula of the naphthalimide organogelator is as follows:
wherein n is 4-18.
2. The method for preparing the naphthohydrazide-type organogelator as claimed in claim 1, wherein the method comprises the following steps: preparing a mixed solution of p-alkoxy benzoic acid and a condensing agent, adding naphthoyl hydrazine, carrying out condensation reaction, and separating and purifying to obtain the naphthoyl hydrazine organogel factor.
3. The method for preparing the naphthohydrazide-type organogelator as claimed in claim 2, wherein the condensing agent comprises EDCI and HOBt;
the molar ratio of the p-alkoxy benzoic acid to the EDCl to the HOBt to the naphthoyl hydrazine is 5 (6-10) to (8-12) to (4-6);
in the mixed solution, the solvent comprises at least one of dichloromethane and ethanol.
4. The method for preparing the naphthohydrazide organogelator as claimed in claim 2, wherein the reaction temperature in the condensation reaction is 18-35 ℃ and the reaction time is 24-36 h.
5. The method for preparing the naphthohydrazide organogelator as claimed in claim 2, wherein the method for preparing the p-alkoxybenzoic acid comprises the following steps:
1) mixing methyl p-hydroxybenzoate and K2CO3Mixing alkyl bromide in an organic solvent, reacting for 7-10h at 70-90 ℃, and sequentially filtering, extracting and separating by column chromatography to obtain p-alkoxy methyl benzoate;
2) reacting methyl p-alkoxybenzoate, NaOH and H2And O is mixed in an organic solvent, the mixture reacts for 5 to 8 hours at the temperature of between 60 and 70 ℃, the pH value is adjusted to between 1 and 2 after the mixture is cooled, the mixture is poured into cold water, flocculent precipitate is collected, and the flocculent precipitate is dried to obtain the p-alkoxy benzoic acid.
6. The method for preparing the naphthohydrazide organogelator as claimed in claim 5, wherein the methyl paraben and K are used in the step 1)2CO3The molar ratio of alkyl bromide is 1 (0.8-1.2) to 0.8-1.2;
the organic solvent comprises N, N-dimethylformamide.
7. According to claim 5The preparation method of the naphthohydrazide organogelator is characterized in that in the step 2), the methyl p-alkoxybenzoate, NaOH and H2The feeding ratio of O is 1g, (0.3-0.5) g, (2-3) mL;
the organic solvent comprises a mixed solution of dichloromethane and ethanol according to the volume ratio of 1 (0.8-1.2).
8. The use of the naphthohydrazide-type organogelator as defined in claim 1, wherein said naphthohydrazide-type organogelator is used for preparing organogel having a fluorine ion responsiveness.
9. The use of the naphthohydrazide organogelator as claimed in claim 8, wherein said organogel is prepared by the following steps: mixing the naphthohydrazide organogel factor with an organic solvent, heating and dissolving the mixture in a sealed state, and cooling the mixture to obtain the organogel with the fluorine ion responsiveness;
in the heating dissolution, the heating temperature is above 80 ℃.
10. The use of the naphthohydrazide-type organogelator as claimed in claim 9,
when n is 12, the critical gel concentration of the naphthohydrazide organogelator in methanol is 1.9 multiplied by 10-2mol/L；
The critical gel concentration of the naphthalimide organogelator in ethanol is 2.0 multiplied by 10-2mol/L；
The critical gel concentration of the naphthalimide organogelator in the propanol is 3.2 multiplied by 10-2mol/L；
The critical gel concentration of the naphthalimide organogel factor in n-butyl alcohol is 5.0 multiplied by 10-2mol/L；
The critical gel concentration of the naphthohydrazide organogelator in isobutanol is 6.8 multiplied by 10-2mol/L；
The naphthalimide organogelator is in tetrahydrofuranHas a critical gel concentration of 1.9X 10-2mol/L；
The critical gel concentration of the naphthalimide organogelator in acetonitrile is 1.9 multiplied by 10-2mol/L。
Technical Field
The invention belongs to the technical field of supramolecular chemistry, and relates to a naphthohydrazide organogel factor, and a preparation method and application thereof.
Background
Fluorine is an essential trace element in human body, plays an important role in the life process, and can be used for dental care and clinical treatment of osteoporosis, but excessive fluorine ions can cause dental fluorosis and even fluorosis. Therefore, the method has great significance for detecting the fluorine ions in the environment, food and medicines. The traditional fluorine ion analysis methods such as ion selective electrode and ion chromatography have the defects of low sensitivity, high cost, complex procedure and the like, and research on fluorine ion stimulation response materials is mostly limited in solution, so that the application range of the fluorine ion stimulation response materials is greatly limited.
Disclosure of Invention
The invention aims to provide a naphthohydrazide organogel factor, a preparation method and application thereof, which are used for solving the problems of low sensitivity, high cost and complex procedure of the existing fluorine detection.
The purpose of the invention can be realized by the following technical scheme:
naphthalic hydrazide type organogelator, N' - [4- (alkoxy) benzoyl]Naphthalene-1-carboxylic acid hydrazide (abbreviated as D)nN-4-18), which has the following structural formula:
wherein n is 4-18.
A preparation method of a naphthohydrazide organogelator comprises the following steps: preparing a mixed solution of p-alkoxy benzoic acid and a condensing agent, adding naphthoyl hydrazine, carrying out condensation reaction, and separating and purifying to obtain the naphthoyl hydrazine organogel factor.
Further, the condensing agent comprises EDCl and HOBt, wherein the molar ratio of p-alkoxy benzoic acid, EDCl, HOBt and naphthoyl hydrazine is 5 (6-10) to (8-12) to (4-6);
in the mixed solution, the solvent comprises at least one of dichloromethane and ethanol.
Further, in the condensation reaction, the reaction temperature is 18-35 ℃, and the reaction time is 24-36 h; the separation and purification comprises extraction and column chromatography separation.
Further, the preparation method of the p-alkoxy benzoic acid comprises the following steps:
1) mixing methyl p-hydroxybenzoate and K2CO3Mixing alkyl bromide in an organic solvent, reacting for 7-10h at 70-90 ℃, and sequentially filtering, extracting and separating by column chromatography to obtain p-alkoxy methyl benzoate;
2) reacting methyl p-alkoxybenzoate, NaOH and H2And O is mixed in an organic solvent, the mixture reacts for 5 to 8 hours at the temperature of between 60 and 70 ℃, the pH value is adjusted to between 1 and 2 after the mixture is cooled, the mixture is poured into cold water, flocculent precipitate is collected, and the flocculent precipitate is dried to obtain the p-alkoxy benzoic acid.
Further, in the step 1), the methyl p-hydroxybenzoate and the K-hydroxybenzoate are2CO3The molar ratio of alkyl bromide is 1 (0.8-1.2) to 0.8-1.2;
the organic solvent comprises N, N-dimethylformamide.
Further, in the step 2), the methyl p-alkoxybenzoate, NaOH and H2The feeding ratio of O is 1g, (0.3-0.5) g, (2-3) mL;
the organic solvent comprises a mixed solution of dichloromethane and ethanol according to the volume ratio of 1 (0.8-1.2).
The application of the naphthalimide organogelator is specifically that the naphthalimide organogelator is used for preparing organogel with fluorine ion responsiveness.
Further, the preparation method of the organogel comprises the following steps: mixing the naphthohydrazide organogel factor with an organic solvent, heating and dissolving the mixture in a sealed state, and cooling the mixture to obtain the organogel with the fluorine ion responsiveness; in the heating dissolution, the heating temperature is above 80 ℃.
Further, when n is 12, the critical gel concentration of the naphthohydrazide organogelator in methanol is 1.9 multiplied by 10-2mol/L, phase transition temperature of 62 ℃, and gel forming time of 3 minutes;
the critical gel concentration of the naphthalimide organogelator in ethanol is 2.0 multiplied by 10-2mol/L, phase transition temperature of 40 ℃, and gel forming time of 8 minutes;
the critical gel concentration of the naphthalimide organogelator in the propanol is 3.2 multiplied by 10-2mol/L, the phase transition temperature is 32 ℃, and the gelling time is 5 minutes;
the critical gel concentration of the naphthalimide organogel factor in n-butyl alcohol is 5.0 multiplied by 10-2mol/L, the phase transition temperature is 26 ℃, and the gelling time is 9 minutes;
the critical gel concentration of the naphthohydrazide organogelator in isobutanol is 6.8 multiplied by 10-2mol/L, the phase transition temperature is 26 ℃, and the gelling time is 9 minutes;
the critical gel concentration of the naphthalimide organogelator in tetrahydrofuran is 1.9 multiplied by 10-2mol/L, phase transition temperature of 50 ℃, and gel forming time of 6 minutes;
the critical gel concentration of the naphthalimide organogelator in acetonitrile is 1.9 multiplied by 10-2mol/L, phase transition temperature of 54 ℃, and gel forming time of 5 minutes.
Compared with the prior art, the naphthalimide organogel has stronger pi-pi interaction force among naphthalene rings in the molecular structure, can enable various organic solvents to form stable gel, and has simple preparation process and mild reaction conditions; the obtained naphthoyl hydrazine organogel factor takes a naphthalene group as a pi-pi stacking group, a hydrazide bond as a hydrogen bond linking group and a hydrophilic group, and an alkoxy group as a hydrophobic group, and forms a three-dimensional network structure through self-assembly of non-covalent bond acting forces such as hydrogen bond action (mainly intermolecular hydrogen bonds among hydrazide groups), coordination action, hydrophobic action, pi-pi stacking action, van der waals force and the like, and can form gel with various organic solvents such as methanol, ethanol, propanol, n-butyl alcohol, tetrahydrofuran, acetonitrile and the like, wherein the gelling capacity in a methanol solution is the best; and in a gel state, the material has a regular sheet structure, has remarkable specific response to fluorine ions, has the advantages of convenient and quick visual detection effect, thermal reversibility, self-repairability, low toxicity, good stability, easiness in storage and carrying, convenience in use and the like, shows remarkable advantages in the aspect of fluorine ion detection as an intelligent material with wide application prospect, and can realize the detection of quasi-solid fluorine ions.
Drawings
FIG. 1 is a synthesis scheme of a naphthohydrazide organogelator according to the present invention;
FIG. 2 is a NMR spectrum of N' - [4- (dodecyloxy) benzoyl ] naphthalene-1-carboxylic acid hydrazide prepared in example 2;
FIG. 3 is D having fluoride ion responsiveness prepared in example 412-scanning electron micrographs of methanol gel;
FIG. 4 is D having fluoride ion responsiveness prepared in example 412-infrared spectrum of methanol gel;
FIG. 5 shows F in example 5-、Cl-、Br-、I-And CH3COO-After incorporation D12-change in methanol gel;
FIG. 6 shows F in example 5-、Cl-、Br-、I-And CH3COO-After incorporation D12-uv-vis absorption spectrum of methanol gel;
FIG. 7 shows different concentrations F in example 5-After incorporation D12Nuclear magnetic resonance hydrogen spectrum of (a).
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments.
The naphthalimide organogelator is N' - [4- (alkoxy) benzoyl]Naphthalene-1-carboxylic acid hydrazide (abbreviated as D)nN-4-18) having the structural formulaThe following steps:
wherein n is 4-18.
The preparation method of the naphthohydrazide organogelator shown in figure 1 comprises the following steps:
1) mixing methyl p-hydroxybenzoate and K2CO3Mixing alkyl bromides in N, N-dimethylformamide according to the molar ratio of 1 (0.8-1.2), reacting at 70-90 ℃ for 7-10h, and sequentially filtering, extracting and separating by column chromatography to obtain p-alkoxy methyl benzoate;
2) reacting methyl p-alkoxybenzoate, NaOH and H2Mixing O in a solution of dichloromethane/ethanol (v/v ═ 1 (0.8-1.2)) at a feeding ratio of 1g, (0.3-0.5 g), (2-3) mL, reacting at 60-70 ℃ for 5-8h, cooling, adjusting the pH to 1-2, pouring into cold water, collecting flocculent precipitate, and drying to obtain p-alkoxy benzoic acid;
3) adding p-alkoxybenzoic acid, a condensing agent EDCl and HOBt into a dichloromethane/ethanol (v/v ═ 1 (0.8-1.2)) solution, adding naphthoyl hydrazine, carrying out condensation reaction at 18-35 ℃ for 24-36h, and obtaining a white powdery naphthoyl hydrazine organogel factor after extraction and column chromatographic separation; wherein, the mol ratio of the p-alkoxy benzoic acid to the EDCl to the HOBt to the naphthoyl hydrazine is 5 (6-10) to (8-12) to (4-6).
The naphthalimide organogelator can be used for preparing organogel with fluorine ion responsiveness, and the specific preparation method comprises the steps of mixing the naphthalimide organogelator with an organic solvent, heating and dissolving the mixture in a sealed state, and cooling the mixture to obtain the organogel with fluorine ion responsiveness; in the heating and dissolving process, the heating temperature is above 80 ℃.
When n is 12, the critical gel concentration of the naphthohydrazide organogelator in methanol is 1.9 multiplied by 10-2mol/L, phase transition temperature of 62 ℃, and gel forming time of 3 minutes;
critical gel of naphthalimide organogelator in ethanolThe concentration is 2.0 × 10-2mol/L, phase transition temperature of 40 ℃, and gel forming time of 8 minutes;
the critical gel concentration of the naphthohydrazide organogelator in the propanol is 3.2 multiplied by 10-2mol/L, the phase transition temperature is 32 ℃, and the gelling time is 5 minutes;
the critical gel concentration of the naphthalimide organogelator in n-butanol is 5.0 multiplied by 10-2mol/L, the phase transition temperature is 26 ℃, and the gelling time is 9 minutes;
the critical gel concentration of the naphthohydrazide organogelator in isobutanol is 6.8 multiplied by 10-2mol/L, the phase transition temperature is 26 ℃, and the gelling time is 9 minutes;
the critical gel concentration of the naphthohydrazide organogelator in tetrahydrofuran is 1.9 multiplied by 10-2mol/L, phase transition temperature of 50 ℃, and gel forming time of 6 minutes;
the critical gel concentration of the naphthalimide organogelator in acetonitrile is 1.9 multiplied by 10-2mol/L, phase transition temperature of 54 ℃, and gel forming time of 5 minutes.
The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
Example 1:
naphthalimide organogelator (D)6) The preparation method comprises the following steps:
1) adding methyl p-hydroxybenzoate (3.0g, 0.02mol), anhydrous potassium carbonate (2.8g, 0.02mol) and 20mL of DMF into a 100mL round-bottom flask, stirring thoroughly, adding bromohexane (3.0mL, 0.022mol) into the mixture, stirring at 80 deg.C for 8h, filtering, extracting, retaining organic phase, and performing column chromatography to obtain white powder (methyl p-hexyloxybenzoate, B)6)4.2g, yield: 89 percent;
B6the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ7.78(d,2H),6.98(d,2H),4.00(t,2H),3.88(s,3H),1.76(p,2H),1.45(dd,2H),1.39–1.25(m,4H),0.94–0.84(m,3H).
2) b is to be6(2.0g, 0.008mol) was dissolved in 50mL of a dichloromethane/ethanol (v/v ═ 1:1) solution, and 0.8g of NaOH and 5.0mL of H were added2Refluxing at 65 deg.C for 6 hr, cooling to adjust pH to 1-2, pouring into ice water, collecting flocculent precipitate, and oven drying to obtain white powder (p-hexyloxybenzoic acid, C)6)1.7g, yield: 94 percent;
C6the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ7.90(d,2H),7.01(d,2H),4.00(t,2H),1.81–1.72(m,2H),1.50–1.41(m,2H),1.38–1.25(m,4H),0.93–0.84(m,3H).
3) c is to be6Adding a solution of (1.2g and 5mmol), EDCl (1.5g and 8mmol), HOBt (1.3g and 9mmol) and 100mL of dichloromethane/methanol (v/v ═ 1:1) into a 250mL round-bottom flask, stirring until the mixture is completely dissolved, adding naphthoyl hydrazine (0.9g and 5mmol), reacting at room temperature for 24 hours, extracting and collecting an organic phase, and purifying by column chromatography to obtain white powder (N' - [4- (hexyloxy) benzoyl)]Naphthalene-1-carboxylic acid hydrazides, D6)0.9g, yield: 43 percent;
D6the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ9.35(s,1H),9.03(d,1H),8.42(d,1H),7.98(d,1H),7.89(d,1H),7.85(d,2H),7.79(d,1H),7.60–7.55(m,1H),7.55–7.48(m,1H),7.47(d,1H),6.92(d,2H),4.01(t,2H),1.81(p,2H),1.48(t,2H),1.36(dd,4H),0.91(q,3H).
HRMS m/z(ESI):calcd.for C24H26O3N2:[M+Na]+,required:413.1835,found:413.1836.
example 2:
naphthalimide organogelator (D)12) The preparation method comprises the following steps:
1) methyl p-hydroxybenzoate (7.6g, 0.05mol), anhydrous potassium carbonate (6.9g, 0.05mol) and 50mL of DMF were added to a 250mL round-bottomed flask, bromododecane (13.0mL, 0.055mol) was added to the mixture after stirring thoroughly, the mixture was stirred at 80 ℃ for reaction for 8h, and white powder (methyl p-dodecyloxybenzoate, B) was obtained after filtration and column chromatography12)14g, yield: 87 percent;
B12the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ7.98(d,1H),6.90(d,1H),4.00(t,1H),3.88(s,1H),1.79(p,1H),1.45(td,1H),1.38–1.25(m,8H),0.88(t,1H).
2) b is to be12(2.5g, 0.008mol) was dissolved in 50mL of a dichloromethane/ethanol (v/v ═ 1:1) solution, and 0.8g of NaOH and 5.0mL of H were added2Refluxing at 65 deg.C for 6 hr, cooling, adjusting pH to 1-2, pouring into ice water, collecting flocculent precipitate, and oven drying to obtain white powder (p-dodecyloxybenzoic acid, C)12)2.4g, yield: 96 percent;
C12the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ8.05(d,2H),6.93(d,2H),4.02(t,2H),1.80(p,2H),1.46(dd,2H),1.28(d,16H),0.88(t,3H).
3) c is to be12Adding a solution of (1.5g and 5mmol), EDCl (1.5g and 8mmol), HOBt (1.3g and 9mmol) and 100mL of dichloromethane/methanol (v/v ═ 1:1) into a 250mL round-bottom flask, stirring until the mixture is completely dissolved, adding naphthoyl hydrazine (0.9g and 5mmol), reacting for 36 hours at room temperature, extracting and collecting an organic phase, and purifying by column chromatography to obtain white powder (N' - [4- (dodecyloxy) benzoyl)]Naphthalene-1-carboxylic acid hydrazides, D12)1.1g, yield: 47%;
D12the hydrogen spectrum of Nuclear Magnetic Resonance (NMR) of (A) is shown in FIG. 2:1H NMR(500MHz,Chloroform-d)δ10.04(d,1H),9.72(d,1H),8.43–8.33(m,1H),7.94(d,1H),7.88(s,1H),7.86(s,2H),7.77(d,1H),7.53(d,2H),7.44(t,1H),6.88(d,2H),3.98(t,2H),1.80(q,2H),1.47(t,2H),1.29(d,16H),0.89(t,3H).
HRMS m/z(ESI):calcd.for C30H38O3N2:[M+K]+,required:513.2518,found:513.2514.
example 3:
naphthalimide organogelator (D)16) The preparation method comprises the following steps:
1) adding methyl p-hydroxybenzoate (3.0g, 0.02mol), anhydrous potassium carbonate (2.8g, 0.02mol) and 20mL of DMF into a 100mL round-bottom flask, stirring thoroughly, adding bromohexadecane (6.7mL, 0.022mol) into the mixture, stirring at 80 deg.C for 8h, filtering, and performing column chromatography to obtain white powder (methyl p-hexadecyloxybenzoate, B)16)6.8g, yield: 90 percent;
B16the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ7.97(d,2H),6.90(d,2H),4.00(t,2H),3.88(s,3H),1.79(p,2H),1.45(q,2H),1.32(d,24H),0.88(t,3H).
2) b is to be16(3.0g, 0.008mol) was dissolved in 50mL of a dichloromethane/ethanol (v/v ═ 1:1) solution, and 0.8g of NaOH and 5.0mL of H were added2Refluxing at 65 deg.C for 6 hr, cooling, adjusting pH to 1-2, pouring into ice water, collecting flocculent precipitate, and oven drying to obtain white powder (p-hexadecyloxybenzoic acid, C)16)2.6g, yield: 92 percent;
C16the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ8.04(d,2H),6.93(d,2H),4.02(q,2H),1.79(d,2H),1.46(t,2H),1.29(q,24H),0.88(q,3H).
3) c is to be16Adding a solution of (1.8g and 5mmol), EDCl (1.5g and 8mmol), HOBt (1.3g and 9mmol) and 100mL of dichloromethane/methanol (v/v ═ 1:1) into a 250mL round-bottom flask, stirring until the mixture is completely dissolved, adding naphthoyl hydrazine (0.9g and 5mmol), reacting for 36 hours at room temperature, extracting and collecting an organic phase, and purifying by column chromatography to obtain white powder (N' - [4- (hexadecyloxy) benzoyl)]Naphthalene-1-carboxylic acid hydrazides, D16)1.0g, yield: 39 percent;
D16the structure is characterized as follows:1H NMR(500MHz,Chloroform-d)δ9.45(s,1H),9.11(s,1H),8.41(d,1H),7.96(d,1H),7.88(d,1H),7.84(d,2H),7.78(d,1H),7.56(d,1H),7.53(d,1H),7.46(t,1H),6.90(d,2H),3.99(t,2H),1.81(q,3H),1.46(q,3H),1.27(q,24H),0.88(t,3H).
HRMS m/z(ESI):calcd.for C34H46O3N2:[M+Na]+,required:553.3401,found:553.3407.
example 4:
this example used the naphthohydrazide organogelator (D) of example 212) Preparing an organogel with fluorine ion responsiveness, wherein the preparation process comprises the following steps:
10mg of N' - [4- (dodecyloxy) benzoyl]Naphthalene-1-carboxylic acid hydrazide (D)12) Added to a sealed vial with 0.5mL of methanolHeating to 80 ℃ and keeping the temperature for 3min to completely dissolve the organic gel, and then cooling to room temperature to obtain the stable white organic gel with the fluorine ion responsiveness.
As shown in FIG. 3, which is an SEM image of the organogel, it can be seen that the xerogel formed is regular sheet-like with a diameter of 5-20 μm.
As shown in fig. 4, D is in different states12(D12-methanol xerogel, D12Methanol gel, D12Gel factor powder), it can be seen from the figure that, in the gel state, hydrogen bonds are formed between N-H and C ═ O in the gel molecules; in the powder state, the two N-H stretching vibration peaks are located at 3445 and 3226cm-1The stretching vibration peak of carbonyl (C ═ O) appears at 1640cm-1At least one of (1) and (b); in the xerogel state, the N-H stretching vibration absorption peaks are respectively shifted to 3413cm-1And 3252cm-1At the same time, the stretching vibration peak of carbonyl (C ═ O) is red shifted to 1638cm-1To (3). Meanwhile, in the gel state, the corresponding absorption peaks of the stretching vibration are shifted. This indicates that hydrogen bonding is involved in N' - [4- (alkoxy) benzoyl]The self-assembly process of naphthalene-1-carbonyl hydrazine is one of the main driving forces for gel formation.
Example 5:
this example is used to examine the fluoride ion responsiveness of the white organogel prepared in example 4, and the specific process is as follows: 5 equivalents of tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium acetate were added to a white organogel (10mg of gelator, 0.5mL of methanol solution), respectively, and the results are shown in FIG. 5, in which the gel was broken after the tetrabutylammonium fluoride was added, and the remainder was not significantly changed.
When Cl is observed in combination with the UV-VIS spectrum shown in FIG. 6-、Br-、I-And CH3COO-After the addition, the absorption has almost no influence on the maximum absorption wavelength; when F is present-After addition, the maximum absorption wavelength shifts from a distinct red at 221nm to 225 nm.
FIG. 7 shows the addition of different concentrations F-(0；0.3eq；0.5eq；1.0eq；2.0eq)D12NMR spectrum, it can be seen that when F is absent-When added, the nuclear magnetic resonance peaks of-N (H1/H2) appeared at 10.47 and 10.39ppm, and when added, the amount of F exceeded 1 equivalent-After that, the corresponding NMR peak was completely disappeared, indicating that F-The addition of (a) completely destroys the main driving force (hydrogen bonding) for gel formation. The gel can specifically respond to F-The reason for (a), electronegativity: f (3.98)>O(3.44)>Cl(3.16)>Br(2.96)>I (2.66), therefore F-Can be combined with H on hydrazide in preference to O on carbonyl group, thereby destroying hydrogen bond network in gel system, and changing white opaque gel into colorless transparent solution, and Cl-、Br-、I-Deprotonation cannot easily occur.
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.