An organic chiral supramolecular gel based on 1-naphthylmethylamine and its application in chiral recognition

Abstract

The present invention belongs to the technical field of material preparation, and discloses an organic chiral supramolecular gel based on 1-naphthylmethylamine and its application in chiral recognition. At normal temperature and pressure, 1-naphthylmethylamine and tartaric acid are respectively dissolved in organic solvents and mixed in a certain proportion to obtain a chiral organic supramolecular gel; the prepared organic supramolecular gel has a chiral recognition effect on phenyl chiral amine molecules (such as methylbenzylamine, phenylalaninol, 1,2,3,4-tetrahydro-1-naphthylamine, etc.). The method for preparing the organic chiral supramolecular gel provided by the present invention is simple and easy to repeat, and does not involve complex chemical reactions; the chirality of chiral molecules can be determined according to the macroscopic state of the gel and does not depend on any high-precision instrument, and has broad application prospects in the field of chiral recognition.

Description

Technical Field

[0001] The present invention belongs to the technical field of material preparation, and specifically relates to a preparation method of an organic chiral supramolecular gel based on 1-naphthylmethylamine and its application in chiral recognition. Background Art

[0002] Chirality is one of the basic properties of nature and appears in substances at various scales. Chiral substances play unique roles in nature and are essential for ensuring the normal life activities of organisms. Chiral amine molecules play important roles in fields such as chemical engineering and medicine. For example, methylbenzylamine and phenylalaninol are chiral auxiliaries; 1,2,3,4-tetrahydro-1-naphthylamine is a synthetic intermediate for certain drugs. Different enantiomers of the same chiral substance often have different chemical properties and greatly different pharmacological properties. Therefore, it is necessary to accurately identify the chirality of these chiral molecules. There are many methods for chiral recognition, including chromatography, spectroscopy, electrochemistry, etc. Although these methods have their own advantages, they cannot be directly detected without instruments. Organic supramolecular gels are a type of physical gels, which are generally self-assembled by organic small molecule gelators in selective solvents. Organic supramolecular gels have reversible characteristics. As long as the three-dimensional network structure formed by non-covalent interactions is destroyed, the gel will collapse. At present, there are few reports on using organic supramolecular gels as chiral recognition materials, and there are no relevant reports on achieving naked-eye chiral recognition. Therefore, if a material that can achieve naked-eye chiral recognition through the macroscopic collapse of an organic supramolecular gel can be prepared by utilizing the reversible characteristics of the organic supramolecular gel, it has broad application value. Summary of the Invention

[0003] The purpose of the present invention is to provide a preparation method of an organic chiral supramolecular gel based on 1-naphthylmethylamine and its application in chiral recognition. This method is simple to operate and has excellent experimental repeatability.

[0004] The above technical purpose of the present invention is achieved through the following technical solutions.

[0005] A preparation method of an organic chiral supramolecular gel based on 1-naphthylmethylamine, the specific steps are as follows:

[0006] Dissolve 1-naphthylmethylamine and tartaric acid in the same organic solvent respectively, and then mix the two according to a certain ratio under normal temperature and pressure. When the two assembly units are mixed, it will trigger the rapid assembly of the system and form an organic supramolecular gel, and an organic chiral supramolecular gel can be obtained.

[0007] Preferably, the tartaric acid is one of L-tartaric acid (LTA) and D-tartaric acid (DTA), and the organic gels formed by the two have the same chiral recognition ability. The concentration range of tartaric acid in the mixed system is 0.6 - 5 mg / mL.

[0008] Preferably, the organic solvent is any one of THF, ethyl acetate, dioxane, n-butanol, and isopropanol.

[0009] Preferably, 1-naphthylmethylamine and tartaric acid solution are mixed in a molar ratio of 1:1 to 5 to form an organogel. The transparency of the organogel increases with the increase in the proportion of tartaric acid.

[0010] Application of the organic chiral supramolecular gel based on 1-naphthylmethylamine in chiral recognition, specifically:

[0011] Chiral molecules are added to the organic supramolecular gel in a certain proportion, and the chirality of the molecules is judged according to the change in the macroscopic state of the gel.

[0012] Preferably, the chiral molecule is a phenyl chiral amine molecule, such as any one of methylbenzylamine, phenylalaninol, and 1,2,3,4-tetrahydro-1-naphthylamine (THAN). Other phenyl chiral amine molecules with similar structures can also be expected to achieve chiral recognition.

[0013] Preferably, when the addition amount of the chiral molecule reaches 0.2% of the mass of the organogel, macroscopic gel collapse can be observed to achieve chiral recognition, and when the addition amount reaches 0.3%, instantaneous chiral recognition can be achieved.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] The method for preparing the organic chiral supramolecular gel provided by the present invention is simple and easy to repeat, and does not involve complex chemical reactions; the chirality of the chiral molecule can be determined according to the macroscopic state of the gel and does not depend on any high-precision instrument, and has broad application prospects in the field of chiral recognition. Brief Description of the Drawings

[0016] Figure 1 It is a physical picture of the organic supramolecular gel obtained in Example 1.

[0017] Figure 2 It is a scanning electron microscope image of the organic supramolecular gel obtained in Example 2: (a) THF, (b) ethyl acetate, (c) dioxane, (d) isopropanol.

[0018] Figure 3 It is a physical picture of the organic supramolecular gel obtained in Example 3.

[0019] Figure 4 It is the (a-c) SEM and (d, e) TEM images of the organic supramolecular gel obtained in Example 3.

[0020] Figure 5 It is a scanning electron microscope image of the organic supramolecular gel obtained by adding S-MBAm in Example 3. Detailed implementation mode

[0021] The technical features of the present invention are further illustrated by the following embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0022] Example 1: Mixing LTA / DTA and NMA in THF

[0023] Dissolve 5.0 mg of L-tartaric acid (LTA) and 5 μL of 1-naphthylmethylamine (NMA) in 1 mL of THF respectively. Under normal temperature and pressure, mix the two according to a molar ratio of 1:1. When the two assembly units are mixed, it will trigger the rapid assembly of the system and form an organic supramolecular gel.

[0024] Dissolve 5.0 mg of D-tartaric acid (DTA) and 5 μL of 1-naphthylmethylamine (NMA) in 1 mL of THF respectively. Under normal temperature and pressure, mix the two according to a molar ratio of 1:1. When the two assembly units are mixed, it will trigger the rapid assembly of the system and form an organic supramolecular gel.

[0025] Example 2: Mixing LTA and NMA in different organic solvents

[0026] Dissolve 5.0 mg of L-tartaric acid (LTA) and 5 μL of 1-naphthylmethylamine (NMA) in 1 mL of THF, ethyl acetate, dioxane, and isopropanol respectively. Under normal temperature and pressure, mix NMA and LTA dissolved in the same solvent according to a molar ratio of 1:1, and an organic supramolecular gel is rapidly formed in the system. Perform SEM tests on the organic supramolecular gels formed in different solvents to observe their microscopic morphologies. As Figure 2 shown, it is found that nanowires with a large aspect ratio and entangled high-level helical nanowires can be obtained. The above results indicate that the formation of the gel three-dimensional network is due to physical cross-linking between nanowires.

[0027] Example 3: Chiral recognition of methylbenzylamine (MBAm) by organic supramolecular gel

[0028] Dissolve 5.0 mg of LTA and 5 μL of NMA in 1 mL of THF respectively. Under normal temperature and pressure, mix the two according to a molar ratio of 1:1, and an organic supramolecular gel is rapidly formed in the system. Taking the amount of substance of 1-naphthylmethylamine as the standard, add 1, 1.25, 1.5, 1.75, and 2 eq (equivalent to 0.3%, 0.34%, 0.45%, 0.53%, and 0.6% of the mass of the organic gel) of MBAm / THF solution to the obtained organic supramolecular gel. It can be observed that the addition of R-MBAm does not cause any visible macroscopic changes in the gel state; while when the addition amount of S-MBAm is greater than or equal to 0.3%, the gel will rapidly collapse macroscopically. AsFigure 5 After the recognition reaction occurred, the morphology of the assembly changed from the initial helical nanowires to particles with a diameter of about 400 nm. This morphological transformation was the direct cause of the gel breaking and collapsing.

[0029] Example 4: Chiral Recognition of Phenylalaninol by an Organic Supramolecular Gel

[0030] Dissolve 5.0 mg of LTA and 5 μL of NMA in 1 mL of THF respectively. Mix the two at a molar ratio of 1:1 under normal temperature and pressure, and an organic supramolecular gel is rapidly formed in the system. Taking the amount of substance of 1-naphthylmethylamine as the standard, add 1, 1.25, 1.5, 1.75, and 2 eq (equivalent to 0.3%, 0.34%, 0.45%, 0.53%, and 0.6% of the mass of the organic gel) of phenylpropanol / THF solution to the obtained organic supramolecular gel. It can be observed that when the addition amount of (L)-(-)-phenylalaninol is greater than or equal to 0.3%, the gel rapidly turns into a white precipitate and collapses; while when (D)-(+)-phenylalaninol is added, the gel does not collapse under the same conditions.

[0031] Example 5: Chiral Recognition of 1,2,3,4-Tetrahydro-1-naphthylamine (THAN) by an Organic Supramolecular Gel

[0032] Dissolve 5.0 mg of LTA and 5 μL of NMA in 1 mL of THF respectively. Mix the two at a molar ratio of 1:1 under normal temperature and pressure, and an organic supramolecular gel is rapidly formed in the system. Taking the amount of substance of 1-naphthylmethylamine as the standard, add 1, 1.25, 1.5, 1.75, and 2 eq (equivalent to 0.3%, 0.34%, 0.45%, 0.53%, and 0.6% of the mass of the organic gel) of THAN / THF solution to the obtained organic supramolecular gel. It can be observed that when the addition amount of (S)-(+)-THNA is greater than or equal to 0.3%, the gel rapidly turns into a white precipitate and collapses; while when (R)-(-)-THNA is added, the gel does not collapse under the same conditions.

[0033] Example 6: Mixing of Dodecylamine and LTA in THF

[0034] Dissolve 5.0 mg of L-tartaric acid (LTA) and 7.9 μL of dodecylamine in 1 mL of THF respectively. Mix the two at a molar ratio of 1:1 under normal temperature and pressure. When the two assembly units are mixed, it will trigger the rapid assembly of the system and form a white precipitate, which cannot be applied in chiral recognition.

[0035] Example 7: Mixing of Benzylamine and LTA in THF

[0036] Dissolve 5.0 mg of L-tartaric acid (LTA) and 3.7 μL of benzylamine in 1 mL of THF respectively. Under normal temperature and pressure, mix the two in a molar ratio of 1:1. When the two assembly units are mixed, it will trigger the rapid assembly of the system and form an organogel. Taking the amount of substance of benzylamine as the standard, add 1, 1.25, 1.5, 1.75, and 2 eq (equivalent to 0.3%, 0.34%, 0.45%, 0.53%, and 0.6% of the mass of the organogel) of MBAm / THF solution to the obtained organogel. It can be observed that the addition of S-MBAm or R-MBAm does not cause any visible change in the macroscopic state of the gel. Add phenylalaninol and 1,2,3,4-tetrahydro-1-naphthylamine to the obtained organogel respectively according to such a ratio. It is observed that the addition of different chiral phenylamine molecules does not cause any visible change in the macroscopic state of the gel.

Claims

1. A method for preparing an organic chiral supramolecular gel based on 1-naphthylmethylamine, characterized in that, it comprises the following steps: Dissolve 1-naphthylmethylamine and tartaric acid in the same organic solvent respectively, and then mix the two in proportion under normal temperature and pressure to obtain an organic chiral supramolecular gel; The organic solvent is selected from any one of tetrahydrofuran, ethyl acetate, dioxane, n-butanol, and isopropanol; wherein the molar ratio of 1-naphthylmethylamine to tartaric acid is 1:1 to 1:

5.

2. The method for preparing an organic chiral supramolecular gel based on 1-naphthylmethylamine according to claim 1, characterized in that: The tartaric acid is any one of L-tartaric acid and D-tartaric acid.

3. An organic chiral supramolecular gel based on 1-naphthylmethylamine, characterized in that: The gel is prepared by the method of claim 1 or 2.

4. The application of the organic chiral supramolecular gel based on 1-naphthylmethylamine according to claim 3 in chiral recognition, characterized in that: The application includes adding the phenyl chiral amine molecule to be recognized into the organic supramolecular gel, wherein the addition amount of the phenyl chiral amine molecule is greater than or equal to 0.2% of the mass of the organic supramolecular gel, and the chirality of the phenyl chiral amine molecule is recognized according to whether the macroscopic state of the gel collapses.

5. The application according to claim 4, characterized in that: The phenyl chiral amine molecule is selected from at least one of methylbenzylamine, phenylalaninol, and 1,2,3,4-tetrahydro-1-naphthylamine.

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