Octaneoxy-modified imine gel factor, two-component gel, and preparation method and application thereof

Abstract

The present invention relates to the technical field of organic supramolecular chemical materials, and in particular to an octyloxy-modified imine gelator, a two-component gel thereof, a preparation method and an application thereof. The gelator is symmetrical. o The invention discloses an octaneoxy-modified terephthalaldehyde-maleonitrile imine gel factor with obvious aggregation-induced emission performance; the gel factor and cholesterol half ester gelator can form a non-fluorescent emission two-component organic gel in an organic solvent; the non-fluorescent emission two-component gel formed in tert-butyl alcohol presents a red fluorescent emission gel when it comes into contact with water, and turns into a blue fluorescent emission gel when it comes into contact with NaClO, which can realize fast and intuitive detection of water and NaClO; the fluorescence of the gel factor is enhanced and blue-shifted when it comes into contact with NaClO in the solution state, and it has fluorescence "off-on" detection for NaClO. 2+ After that, the fluorescence emission intensity decreased and the Hg 2+ With fluorescence "on-off" detection performance.

Description

Technical Field

[0001] The present invention relates to the technical field of supramolecular chemical materials, and in particular to an octaneoxy-modified imine gel factor, a two-component gel, and a preparation method and application thereof. Background Art

[0002] Organic small molecule gels are a class of soft materials with a three-dimensional network structure. They primarily form a cross-linked network structure through non-covalent interactions between gelling factors (such as hydrogen bonds, π-π interactions, and van der Waals forces), thereby binding large amounts of solvent and reducing the fluidity of the system. These non-covalent interactions are susceptible to environmental stimuli, causing the gel system to undergo significant changes. Therefore, as a new type of intelligent soft material, organic small molecule gels offer rapid response to external stimuli, intuitive signal generation, high sensitivity, and simple operation, making them promising for applications in areas such as adsorption and separation, and drug delivery. Organic small molecule fluorescent gels, which embed luminescent groups within a three-dimensional network structure, can change the color or intensity of their emission in response to external stimuli. They also possess advantages such as self-healing and biocompatibility. They are widely used in fields such as biomedical imaging and environmental sensing, and are currently at the forefront of research at the intersection of materials science and chemistry.

[0003] Organic small molecule gels can be categorized as single-component gels and multi-component gels. Single-component gels involve a single organic gelator that gelates a solvent through non-covalent interactions. Multi-component gels involve two or more organic gelators that interact non-covalently to form a structurally stable complex, which then assembles hierarchically to form a three-dimensional network structure. Two-component gels, formed by two organic gelators, are the simplest and most extensively studied multi-component gel systems to date. In recent years, traditional single-component organogels have often struggled to meet complex application requirements due to limitations such as limited functionality, insufficient mechanical strength, and poor environmental stability. In two-component gel systems, a single minor structural adjustment of the gelator can alter numerous properties, and the two components can introduce functional structures into the gel system. Compared to single-component systems, two-component gels possess unique new properties, greater stability, and greater structural flexibility. Consequently, researchers have increasingly turned their attention to two-component synergistic gel systems, optimizing material properties and integrating functions through the coordinated assembly of different functional molecules. Cholesterol and its derivatives, due to their rigid steroidal structure and amphiphilic properties, have become ideal candidates for constructing organogels. For example, maleic anhydride, a cyclic anhydride containing a double bond, forms an ester bond with the hydroxyl group of cholesterol through a ring-opening reaction to obtain an amphiphilic cholesterol half-ester derivative. This not only retains the gel assembly ability of cholesterol, but the introduced carboxylic acid group can also enhance intermolecular cross-linking through hydrogen bonding or electrostatic interactions, thereby improving gel stability. In addition, to form a stable organic small molecule fluorescent gel, long-chain alkyl groups can be introduced into the luminescent gel factor to promote intermolecular entanglement, enhance the self-assembly driving effect, and form a more stable organic small molecule luminescent gel material. However, there is little research on the performance of organic fluorescent factors prepared with 2,5-octyloxyterephthalaldehyde as the building block and the two-component gel formed with cholesterol half-ester derivatives. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides an octyloxy-modified imine gelator, a two-component gel, and a preparation method and application thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] An octyloxy-modified imine gel factor, the gel factor is symmetrical o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor, its structure is: .

[0007] The symmetrical o -Octaneoxy-modified terephthalaldehyde-maleonitrile imine gel factor has aggregation-induced fluorescence emission properties.

[0008] Another object of the present invention is to provide the oThe preparation method of the octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor comprises the following steps:

[0009] Dissolve 2,5-(bisoctyloxy)terephthalaldehyde in EtOH-DMF mixed solvent, add 2,3-diaminomaleonitrile and concentrated sulfuric acid in sequence, heat and reflux for 10-12 hours; cool the reaction solution to room temperature, filter, wash with methanol, and dry to obtain orange o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor.

[0010] Furthermore, the molar ratio of the 2,5-(bisoctyloxy)terephthalaldehyde and diaminomaleonitrile is 1:2, the volume ratio of EtOH and DMF in the mixed solvent is 9:1, the amount of the mixed solvent added is limited to 20 mL of the mixed solvent per 1 mmol of 2,5-(bisoctyloxy)terephthalaldehyde, and the amount of sulfuric acid added is 50 μL of sulfuric acid per 1 mmol of 2,5-(bisoctyloxy)terephthalaldehyde.

[0011] described o The preparation reaction formula of the octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor is: .

[0012] The third object of the present invention is to provide o A method for forming a two-component organic gel by octyloxy-modified terephthalaldehyde-maleonitrile imine gelator (TD) and cholesterol half-ester gelator (CS) includes the following steps, using a heating-low-temperature ultrasonic cooling gelation method: the octyloxy-modified imine gelator and the cholesterol half-ester gelator are mixed in a molar mass ratio of 1:20, an organic solvent is added, and the mixture is heated until the two-component gelator is completely dissolved, followed by ultrasonic cooling at about -10°C for 3 minutes to form a two-component gel material.

[0013] Furthermore, the organic solvent is one of methanol, ethanol, isopropanol, tert-butanol, and acetone.

[0014] The fourth object of the present invention is to provide o The TDCS two-component gel formed by -octyloxy-modified terephthalaldehyde-maleonitrile imine gelator and cholesterol half-ester gelator in tert-butanol was applied to H2O detection.

[0015] The specific performance is as follows: the TDCS two-component gel formed in tert-butanol has no fluorescence emission performance, and after the addition of H2O, it changes from no fluorescence emission to orange-red fluorescence emission gel.

[0016] The fifth object of the present invention is to provide oThe TDCS two-component gel formed by -octyloxy-modified terephthalaldehyde-maleonitrile imine gelator and cholesterol half-ester gelator in tert-butanol was applied to NaClO detection.

[0017] The specific performance is as follows: the TDCS two-component gel formed in tert-butanol has no fluorescence emission performance. After the addition of NaClO, it changes from no fluorescence emission to blue fluorescence emission gel.

[0018] The sixth object of the present invention is to provide o -Octaneoxy-modified terephthalaldehyde-maleonitrile imine gel factor was applied to the detection of NaClO in solution.

[0019] Furthermore, the o The specific detection function of the -octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor for NaClO in the solution state is as follows: the imine gel factor solution has a maximum fluorescence emission near 522 nm. When NaClO is added, its maximum fluorescence emission gradually increases and blue-shifts to 472 nm, showing an obvious fluorescence "off-on" detection response to NaClO.

[0020] The seventh object of the present invention is to provide the o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor to Hg 2+ Detection application.

[0021] Furthermore, the o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor has a maximum fluorescence emission around 522 nm, Hg 2+ After the addition of Hg, the maximum fluorescence emission intensity decreased and red-shifted to 570 nm. The fluorescence emission spectrum of the gel factor remained basically unchanged after the addition of other metal ions, indicating that the imine gel factor has a strong effect on Hg 2+ It has a clear fluorescence "on-off" detection response.

[0022] Compared with the prior art, the present invention has the following technical effects: o-Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor has aggregation-induced fluorescence emission performance; the gel factor and cholesterol half ester gelator (CS) can form yellow two-component organic gel in methanol, ethanol, isopropanol, tert-butanol, etc., and the two-component gel without fluorescence emission formed in tert-butanol exhibits orange-red fluorescence emission when encountering water, and has an intuitive signal detection response to water; the fluorescence of the gel factor is enhanced and blue-shifted after adding NaClO in the solution state, and it forms a two-component gel with cholesterol half ester gelator in tert-butanol, which changes from no fluorescence emission to blue fluorescence emission gel when encountering NaClO, realizing the rapid, intuitive and sensitive detection of NaClO in the dual state of the gel factor solution and gel; the gel factor is added with Hg in the solution state. 2+ After that, the fluorescence emission intensity decreased and the Hg 2+ It has fluorescence "on-off" detection performance. o -Octaneoxy-modified terephthalaldehyde-maleonitrile imine gel factor and its two-component gel assembled with cholesterol half ester gelator have the advantages of mild synthesis conditions and simple preparation, which creates favorable conditions for its promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 for o -NMR spectrum of terephthalaldehyde-maleonitrile imine gel factor modified with octyloxy.

[0024] Figure 2 for o -UV absorption spectra of octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor in organic-water solvents with different ratios.

[0025] Figure 3 for o Aggregation-induced fluorescence emission of octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor.

[0026] Figure 4 for o Image of a two-component tDCS gel formed by a terephthalaldehyde-maleonitrile imine gelator modified with a cholesterol half-ester gelator.

[0027] Figure 5 The fluorescence emission images of the TDCS two-component gel formed in tert-butanol before and after adding water under UV light.

[0028] Figure 6 The fluorescence emission graph of the TDCS two-component gel formed in tert-butanol before and after adding NaClO under UV light.

[0029] Figure 7 SEM image of the TDCS two-component gel formed in tert-butanol before the addition of NaClO.

[0030] Figure 8 SEM image of the TDCS two-component gel formed in tert-butanol after adding NaClO.

[0031] Figure 9 for o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gelling factor solution state for NaClO fluorescence detection performance.

[0032] Figure 10 for o -Octyloxy modified terephthalaldehyde-maleonitrile imine gelling factor solution state Hg 2+ Fluorescence detection performance.

[0033] Figure 11 for o -Octyloxy modified terephthalaldehyde-maleonitrile imine gelling factor solution state Hg 2+ Compete with other metal ions for performance. DETAILED DESCRIPTION

[0034] The present invention discloses a kind of aggregation-induced fluorescence emission o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor, its molecular structure is:

[0035] .

[0036] It can be prepared by a one-step polymerization reaction using 2,5-(bisoctyloxy)terephthalaldehyde and diaminomaleonitrile as reaction raw materials. The synthesis reaction formula is:

[0037] .

[0038] Example 1

[0039] Preparation of compound A: Dissolve 1 mmol of 2,5-(dioctyloxy)terephthalaldehyde in 20 mL of EtOH-DMF (9:1), add 2 mmol of 2,3-diaminomaleonitrile and 50 μL of concentrated sulfuric acid, and heat under reflux for 10 hours. The reaction solution is cooled to room temperature, filtered, washed with methanol, and dried to obtain an orange compound (400 mg, 70% yield).

[0040] Example 2

[0041] Preparation of compound B: Dissolve 1 mmol of 2,5-(dioctyloxy)terephthalaldehyde in 20 mL of EtOH-DMF (9:1), add 2 mmol of 2,3-diaminomaleonitrile and 50 μL of concentrated sulfuric acid, and heat under reflux for 12 hours. The reaction solution is cooled to room temperature, filtered, washed with methanol, and dried to obtain an orange compound (411 mg, 72% yield).

[0042] Compounds A and B obtained in Examples 1 and 2 were analyzed and determined by NMR. Figure 1 To, see Figure 1 , the NMR data are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 8.61 (s, 1H), 8.11 (s, 2H), 7.84 (s,1H), 4.12 (s, 2H), 1.73 (s, 2H), 1.47 (s, 2H), 1.30 (s, 4H), 1.25 (s, 4H),0.85 (s, 3H); MS: ion peak m / z 570.38, [theoretical calculated value M + is 570.34]; indicating that compound A / B and o The theoretical values ​​of the gelling factors of -octyloxy modified terephthalaldehyde-maleonitrile imine are basically consistent. Therefore, it can be confirmed that the molecular structures of compounds A and B are:

[0043] ,Right now o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor.

[0044] Example 3

[0045] o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor aggregation performance: concentration of 2×10 -4 M's o The UV absorption spectrum test of the octyloxy modified terephthalaldehyde-maleonitrile imine gel factor in different proportions of THF-water mixed solvents showed that: in pure THF, the gel factor had a maximum absorption peak at 462 nm and a slightly weak shoulder peak near 498 nm; as the water content in the mixed solvent increased from 0% to 60%, the absorption spectrum of the gel factor hardly changed; when the water content increased from 60% to 90%, the absorption peaks at 462 and 498 nm shifted red, the absorbance decreased, and the absorption tail after 510 nm tilted; continuing to increase the proportion of water in the mixed solvent to 95%, its UV absorption absorbance decreased significantly, and it showed a broad absorption peak without structural characteristics, indicating that o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor aggregates in THF-water mixed solvent with a water content of more than 60%, see Figure 2 .

[0046] Example 4

[0047] o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor aggregation induced fluorescence emission performance: The fluorescence emission spectrum test of the gel factor in different proportions of THF-water mixed solvents showed that: as the water content in the mixed solvent increased from 0% to 60%, the weak fluorescence emission of the gel factor near 534 nm remained basically unchanged; increasing the water content from 60% to 90%, its fluorescence emission at 534 nm was significantly enhanced and red-shifted to near 570 nm; continuing to increase the proportion of water in the mixed solvent to 95%, the above-mentioned enhanced fluorescence emission was slightly reduced. These studies show that o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor has aggregation induced emission properties in THF-water mixed solvent with slightly higher water content, see Figure 3 .

[0048] Example 5

[0049] o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor formed a two-component gel performance: The gel was prepared by the "heating-low temperature ultrasonic cooling" method. o The octyloxy-modified terephthalaldehyde-maleonitrile imine gelator (TD) and cholesterol half-ester gelator (CS) were two-component gelators. According to the TD:CS molar mass ratio of 1:20, 1 mg of TD and the corresponding amount of CS gelator were weighed and placed in a series of 2 mL glass vials. 0.3 mL of organic solvents such as methanol, ethanol, isopropanol, tert-butanol, acetone, dichloromethane, acetonitrile, and ethyl acetate were added respectively. After heating until the two-component gelator was completely dissolved, ultrasonic cooling was carried out at around -10°C for 3 minutes. The two-component gelators TD and CS formed yellow TDCS two-component gels in solvents such as methanol, ethanol, isopropanol, tert-butanol, and acetone, as shown in FIG. Figure 4 .

[0050] Example 6

[0051] Water detection performance of two-component gel TDCS in tert-butanol: In pure tert-butanol, the two components of TDCS form a three-dimensional gel network through hydrogen bonding, hydrophilic and hydrophobic interactions, and the TD gel factor exists in a monodisperse state. Its benzene ring can rotate freely, and the excited state energy is dissipated through non-radiative transition pathways, resulting in no fluorescence emission when it forms a gel as an organic fluorescent gel factor. In a tert-butanol-H2O mixed solvent (9:1 v / v), the two-component gel TDCS forms an orange-red fluorescence emitting gel. Figure 5 , indicating that the TDCS two-component gel in tert-butanol has the potential for intuitive signal detection of water.

[0052] Example 7

[0053] Detection performance of two-component TDCS gel in tert-butanol for NaClO: A yellow non-fluorescent TDCS two-component organogel was first prepared in tert-butanol by the "heating-ultrasonic cooling" method. 0.1 mol / L NaClO dilution was then added dropwise to the surface of the gel. Under 365 nm UV light, the TDCS two-component gel transformed from non-fluorescent to blue fluorescent (Figure 6). Field emission scanning electron microscopy (SEM) o The micromorphology of the TDCS two-component dry gel formed by the addition of NaClO before and after the addition of 2-alkoxy-substituted bis-salicylimide organic fluorescent gel factor and amphiphilic cholesterol half-ester gel was characterized. It was found that in the tert-butanol system, the TDCS two-component self-assembled gel showed an intertwined three-dimensional network structure. Figure 7 After adding NaClO, the microstructure of TDCS gel changed from the initial entangled interwoven structure to a disordered lamellar structure. Figure 8 These studies showed that the TDCS two-component gel has the potential to detect ClO⁻ in situ, real-time, on-site, intuitively and quickly.

[0054] Example 8

[0055] o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor solution for NaClO detection performance: in 90% DMF aqueous solution, the concentration of 2×10 -5 mol / L o Fluorescence emission properties of the octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor with different concentrations of NaClO: The imine gel factor has a maximum fluorescence emission near 522 nm. As the concentration of NaClO is increased from 0 to 100 times the molar equivalent, the fluorescence emission of the gel factor at 522 nm gradually increases and blue-shifts to 472 nm, indicating that o The -octaneoxy-modified terephthalaldehyde-maleonitrile imine gel factor has a fluorescence "off-on" detection performance for NaClO, as shown in Figure 9.

[0056] Example 9

[0057] o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor solution for metal ion detection performance: in 90% DMF aqueous solution, the concentration was 1×10 -5 mol / L o -octyloxy modified terephthalaldehyde-maleonitrile imine gel factor was added with 10 times the molar equivalent of Na + 、Fe3+ , K + 、Li + 、Hg 2+ 、Co 2+ , Pb 2+ Cr 3+ 、Al 3+ 、Cd 2+ , Ca 2+ 、Mn 2+ 、Ni 2+ 、Cu 2+ , Pb 2 + 、Zn 2+ The fluorescence emission performance test showed that the gel factor has a maximum fluorescence emission peak at 522 nm; 10 times the molar equivalent of Hg 2+ After addition, the maximum fluorescence emission intensity decreased by 52%; other metal ions such as Na + 、Fe 3+ , K + 、Li + 、Co 2+ , Pb 2+ Cr 3+ 、Al 3+ 、Cd 2+ , Ca 2+ 、Mn 2+ 、Ni 2+ , Pb 2+ 、Zn 2+ After addition, the fluorescence emission spectrum of the gel factor showed almost no significant change, indicating that o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor to Hg 2+ Ions have an intuitive fluorescence "on-off" signal monitoring response, see Figure 10 .

[0058] Example 10

[0059] o Hg in the solution of terephthalaldehyde-maleonitrile imine gel factor modified by -octyloxy 2+ Competitive performance with other metal ions: In 90% DMF aqueous solution, the concentration is 1×10 -5 mol / L o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor was added with 10 times the molar equivalent of Hg 2+ After adding other different metal ions, the fluorescence emission spectrum study of the ternary mixed system shows that: o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor was added with 10 times the molar equivalent of Hg 2+After that, the maximum fluorescence emission intensity at 522 nm decreased; when Na + 、Fe 3+ , K + 、Li + 、Co 2+ , Pb 2+ Cr 3+ 、Al 3+ 、Cd 2 + , Ca 2+ 、Mn 2+ 、Ni 2+ , Pb 2+ 、Zn 2+ Metal ions such as Cu 2+ At the same time add o After the terephthalaldehyde-maleonitrile imine gel factor was modified with -octyloxy, the fluorescence emission of the ternary system was o -Octyloxy-modified terephthalaldehyde-maleonitrile imine gel factor-Hg 2+ The fluorescence emission of the binary system is similar, and the specific results can be found in Figure 11 , indicating that even if other metal ions exist, o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor to Hg 2+ It has good selectivity and sensitive fluorescence "on-off" detection response.

Claims

1. An octyloxy-modified imine gelator, characterized in that: The gel factor is symmetrical o -Octyloxy modified terephthalaldehyde-maleonitrile imine gel factor, its structure is: 。 2. A method for preparing an octyloxy-modified imine gelator according to claim 1, characterized in that: The steps include: Dissolve 2,5-(bisoctyloxy)terephthalaldehyde in EtOH-DMF mixed solvent, add 2,3-diaminomaleonitrile and concentrated sulfuric acid in sequence, heat and reflux for 10-12 hours; cool the reaction mixture to room temperature, filter, wash with methanol, and dry to obtain orange o -Octaneoxy modified terephthalaldehyde-maleonitrile imine gel factor; the synthetic reaction formula is as follows: 。 3. The method for preparing the octyloxy-modified imine gelator according to claim 2, wherein: The molar ratio of the 2,5-(bisoctyloxy)terephthalaldehyde and diaminomaleonitrile is 1:2, the volume ratio of EtOH and DMF in the mixed solvent is 9:1, the amount of the mixed solvent added is limited to 20 mL of the mixed solvent per 1 mmol of 2,5-(bisoctyloxy)terephthalaldehyde, and the amount of sulfuric acid added is 50 μL of sulfuric acid per 1 mmol of 2,5-(bisoctyloxy)terephthalaldehyde.

4. Use of the octyloxy-modified imine gelator according to claim 1 in NaClO detection, wherein the use does not involve the diagnosis and treatment of diseases.

5. An octyloxy-modified imine gel factor as claimed in claim 1 in Hg 2+ The application of the invention is not related to the diagnosis and treatment of diseases.

6. A method for preparing a two-component gel comprising the octyloxy-modified imine gelator according to claim 1, characterized in that: The heating-low-temperature ultrasonic cooling gelation method was adopted: the octyloxy-modified imine gel factor and the cholesterol half-ester gelator were mixed in a molar mass ratio of 1:20, an organic solvent was added, and the mixture was heated until the two-component gel factor was completely dissolved. The mixture was then ultrasonically cooled at about -10°C for 3 min to form a two-component gel material.

7. A two-component gel comprising an octyloxy-modified imine gelator prepared by the method according to claim 6.

8. Use of the two-component gel comprising an octyloxy-modified imine gelator as claimed in claim 7 in water detection, wherein the use does not involve the diagnosis and treatment of diseases.

9. Use of the two-component gel comprising an octyloxy-modified imine gelator as claimed in claim 7 in NaClO detection, wherein the use does not involve the diagnosis and treatment of diseases.

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