Chiral supramolecular material from gel to 3D crystal

Abstract

The invention discloses a chiral supramolecular material from gel to 3D crystals. Chiral small organic molecules L-TMPE or D-TMPE are adopted as an assembly element, and the chiral supramolecular gel material with the spiral nanotube structure is formed in a specific solvent in a self-assembly mode. And after aging, the chiral supramolecular gel material begins to collapse and transform so as to form a chiral three-dimensional crystal material with a hexagonal prism shape. The supramolecular gel with the macroscopic spiral nanotube structure is prepared in a supramolecular assembly mode, and the supramolecular gel is a novel chiral supramolecular gel material, has circular polarization luminescence performance and has good capability of inducing achiral luminescent materials to emit light in a circular polarization mode. The chiral supramolecular material has two forms and has different potential application values, the preparation method is simple, a new variety is provided for research of novel chiral supramolecular functional materials, and a new path is provided for novel phase transition chiral materials.

Description

Technical Field

[0001] The present invention belongs to the field of supramolecular chemistry, and particularly relates to a chiral supramolecular material from gel to 3D crystal. Background Art

[0002] Chirality widely exists in nature, which is manifested as the inability of a substance to completely coincide with its mirror image. Chirality not only appears in organic small molecules, but can also be observed in the macroscopic structural systems constructed by these small molecules. Supramolecular chemistry is a chemistry beyond the molecular level and an expansion of molecular chemistry to intermolecular chemistry. Constructing chiral supramolecular materials by supramolecular assembly of chiral organic small molecules has become one of the important directions for the development of chiral materials.

[0003] Chiral supramolecular materials are a class of materials with chiral characteristics and formed based on the principle of supramolecular self-assembly, and have important applications in multiple fields, such as biomedical, optical devices, and catalysis. Through the supramolecular self-assembly process, chiral molecules or chiral building blocks are assembled into materials with specific chiral structures and functions. There are three methods for constructing chiral supramolecular functional materials. One is through molecular design and synthesis: designing and synthesizing molecules with specific chiral centers and functional groups, so that chiral supramolecular materials are formed during the self-assembly process. The second is through the template induction method: using chiral template molecules to induce the chiral assembly of achiral molecules or precursors to obtain chiral supramolecular materials. The third is through physical methods: such as applying physical fields such as electric fields, magnetic fields, and temperature gradients to induce chiral molecules or supramolecular systems to form materials with specific chiral structures. However, it is still a difficult problem to obtain chiral supramolecular materials that can undergo material transformation.

[0004] In the field of chemistry, "aging" is a relatively broad concept, usually referring to the process in which a substance changes in structure, performance, etc. over time under certain environmental conditions. The present invention is expected to utilize this phenomenon to construct a novel chiral supramolecular material from gel to crystal. Summary of the Invention

[0005] The object of the present invention is to provide a chiral supramolecular material from gel to 3D crystal. The present invention uses chiral organic small molecules as assembly building blocks, and under the conditions of a specific solvent, forms a chiral supramolecular gel with a helical nanotube structure through self-assembly; after a certain aging time, the chiral supramolecular gel begins to collapse and transform, and with gradual aging, a 3D crystal structure with a hexagonal prism morphology is formed, and the analysis is confirmed by single crystal.

[0006] The discovery of the chiral supramolecular material from the gel state to the 3D crystal state provided by the present invention offers a new path for the development of novel chiral supramolecular materials. Chiral supramolecular gels have extensive applications in biomedical fields such as drug delivery, biosensing, and tissue regeneration, while the applications of chiral supramolecular crystal materials mainly include fields such as optical devices, catalysis, and gas adsorption and separation. Therefore, the chiral supramolecular material with the transformation provided by the present invention has broad application prospects in many fields.

[0007] Specifically, the chiral organic small molecule L / D-TMPE used in the present invention is a chiral phenylalanine derivative, and its structural formula is shown as follows:

[0008]

[0009] The present invention uses the chiral organic small molecule L / D-TMPE as an assembly unit to perform self-assembly in a specific solvent to form a chiral supramolecular gel with a helical nanotube structure. Through aging, the gel collapses and transforms from the helical nanotube structure into a hexagonal prism-shaped 3D crystal structure, which is confirmed by single crystal analysis.

[0010] Preferably, the specific solvent is a DMSO-water system, and the volume ratio of the two is 6:4 - 4:6, and specifically can be 1:1;

[0011] Preferably, the assembly concentration of the chiral molecule L / D-TMPE is 8 - 30 mg / mL, preferably 10 - 20 mg / mL.

[0012] Preferably, the aging time is 2 weeks or more, more preferably 2 weeks.

[0013] The chiral supramolecular material from gel to 3D crystal provided by the present invention is a chiral supramolecular material with a phase transition, having the application prospects of chiral supramolecular gels in the biomedical and energy device fields, and also having the application prospects of chiral supramolecular crystal materials in fields such as optical devices, catalysis, and gas adsorption and separation. Moreover, this process of gel-to-crystal transformation can also be applied to biosensing encryption.

[0014] The present invention has the following beneficial technical effects:

[0015] (1) The present invention prepares a supramolecular gel with a macroscopic helical nanotube structure through supramolecular assembly. This is a novel chiral supramolecular gel material, which has circularly polarized luminescence properties by itself and has a good ability to induce circularly polarized luminescence of achiral luminescent materials.

[0016] (2) Through the process of aging over time, the chiral supramolecular gel material is transformed into a 3D hexagonal prism crystal material, which is a novel chiral crystal material and has potential application value in fields such as adsorption separation.

[0017] (3) The chiral supramolecular material prepared by the present invention has two forms, with different potential application values, and the preparation method is simple, providing new types for the study of novel chiral supramolecular functional materials and also providing a new path for novel phase transition chiral materials. Description of the Drawings

[0018] Figure 1 It is a process diagram of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE aging to form a crystal assembly.

[0019] Figure 2 It is the SEM image of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE of the present invention; among them, Figure a is the macroscopic morphological feature of the supramolecular gel of L-configuration, and Figure b is the macroscopic morphological feature of the supramolecular gel of D-configuration.

[0020] Figure 3 It is the TEM image of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L-TMPE of the present invention.

[0021] Figure 4 It is the SEM image of the assembly formed by the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE of the present invention through a 2-week aging process; among them, Figure a is the macroscopic morphological feature of the 3D crystal transformed from the supramolecular gel of L-configuration, and Figure b is the macroscopic morphological feature of the 3D crystal transformed from the supramolecular gel of D-configuration.

[0022] Figure 5 It is the CD spectrum of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE of the present invention.

[0023] Figure 6 It is the CPL spectrum of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE of the present invention.

[0024] Figure 7 It is the g lum spectrum of the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L / D-TMPE of the present invention.

[0025] Figure 8 It is the single crystal structure analysis of the assembly formed by the supramolecular gel formed by the supramolecular assembly of the chiral organic molecule L-TMPE of the present invention through a 2-week aging process. Detailed Embodiments

[0026] The present invention will be further described in detail below in conjunction with specific embodiments. The provided embodiments are only for clarifying the present invention and not for limiting the scope of the present invention. The following provided embodiments can be used as a guide for those of ordinary skill in the art to make further improvements, and do not constitute any limitation to the present invention in any way.

[0027] In the following embodiments, the experimental methods, unless otherwise specified, are all conventional methods, carried out according to the techniques or conditions described in the literature in this field or according to the product instructions. The materials, reagents, etc. used in the following embodiments, unless otherwise specified, can all be obtained from commercial channels.

[0028] In the following embodiments, the organic chiral small molecule L / D-TMPE is synthesized through the following steps:

[0029] Dissolve L- or D-phenylalanine methyl ester hydrochloride (966.02 mg, 4.5 mmol) in dichloromethane (150 mL), add triethylamine (506.0 mg, 5.0 mmol), and stir the mixture at room temperature for 30 minutes. Then, dropwise add trimesoyl chloride (265.5 mg, 1.0 mmol), and stir the mixed solution at room temperature overnight. Rotate and dry the reaction solution, dissolve it in methanol solution, and then drop it into saturated salt water, and a white turbid liquid precipitates during stirring. Filter the reaction mixture to obtain a white solid powder (666.0 mg, 96.0% yield). (Refer to the literature reported: DOI: 10.1016 / j.molstruc.2011.09.006), and the reaction process is as follows:

[0030]

[0031] Example 1

[0032] Perform supramolecular assembly of 10 mg of the chiral organic small molecule L / D-TMPE in 1 mL of a mixed solvent (the concentration of L / D-TMPE is 10 mg / mL). The mixed solvent is DMSO / water, and the solvent (volume) ratio is 1:1. First, heat and dissolve the organic molecule and then add water to form a supramolecular gel material. It can be seen from SEM and TEM that the morphology of this gel material is a supramolecular chiral nanotube with helical characteristics, as Figure 2 and Figure 3 shown.

[0033] Through a two-week aging process, the supramolecular gel constructed by the chiral organic small molecule L / D-TMPE is transformed into a chiral crystal material, and the macroscopic state changes from Figure 1As shown, the chiral supramolecular gel collapses and completely transforms into a shiny crystalline material. It can be seen from SEM that the morphology of this crystalline material is a three-dimensional (3D) crystalline material with hexagonal prism shape, as Figure 4 shown.

[0034] The chiral supramolecular gel material was detected by circular polarization spectroscopy and circular dichroism spectroscopy, and it was found to have good chiral optical information. Figure 5 shows the CD signal of the chiral supramolecular gel L- or D-TMPE, and a strong chiral signal with mirror symmetry was observed at 260 nm. In addition, Figure 6 also shows the CPL signal of the chiral supramolecular gel L- or D-TMPE near 350 nm. Figure 7 shows the g lum spectrum, and the g lum values of L- or D-TMPE reach +1.2×10 -2 and -1.2×10 -2 respectively, showing mirror symmetry. It indicates that the chiral supramolecular gel of the present invention shows good chiral optical information and has potential application value in optical information encryption and 3D display.

[0035] After two weeks of aging time, the chiral supramolecular gel transforms into a crystalline material, Figure 8 showing the single crystal analysis of the chiral crystalline material to determine its crystal configuration. The transformation of the chiral material state explores the potential value of the material of the present invention, and this special transformation material becomes a new type of chiral supramolecular material.

[0036] Example 2,

[0037] 20 mg of chiral organic small molecule L / D-TMPE was subjected to supramolecular assembly in 1 mL of mixed solvent (the concentration of L / D-TMPE was 20 mg / mL). The mixed solvent was DMSO / water, and the solvent (volume) ratio was 1:1. First, the organic molecule was heated and dissolved, and then water was added to form a supramolecular gel material. After 20 days of aging time, it was still observed that the supramolecular gel transformed into 3D crystals.

[0038] Comparative Example 1,

[0039] 10 mg of chiral organic small molecule L / D-TMPE was subjected to supramolecular assembly in 1 mL of mixed solvent (the concentration of L / D-TMPE was 10 mg / mL). The mixed solvent was DMSO / water, and the solvent (volume) ratio was 7:3. First, the organic molecule was heated and dissolved, and then water was added, but no supramolecular gel material could be formed and it remained in the solution state. After two weeks of aging time, it was still in the solution state and no 3D crystals could be formed.

[0040] Comparative Example 2,

[0041] 10 mg of chiral organic small molecule L / D-TMPE was subjected to supramolecular assembly in 1 mL of organic solvent (the concentration of L / D-TMPE was 10 mg / mL). The organic solvent was toluene. Heating and dissolving the organic molecules and then allowing them to cool naturally could not form a supramolecular gel material, but the assembly would precipitate. Through two weeks of aging time, the assembly could not form 3D crystals.

[0042] In the present invention, a supramolecular gel is formed by supramolecular self-assembly of chiral organic molecules, and then the supramolecular gel is transformed into a three-dimensional (3D) crystal material through an aging process, which is an interesting and stable phenomenon. During this aging process, the internal structure of the gel gradually changes. Molecules, aggregates, etc. that were originally disordered or in a metastable state will transform towards a more ordered and stable crystalline state. On the one hand, as time goes by, the molecules in the gel system have more opportunities for slow diffusion and rearrangement. The solute molecules, polymer segments, etc. in the gel may initially be randomly distributed. During the aging process, driven by their intermolecular forces (such as van der Waals forces, hydrogen bonds, etc.), they start to seek a lower-energy arrangement, gradually aggregate and arrange according to certain lattice rules, laying the foundation for the formation of a crystal structure. On the other hand, during aging, some tiny crystal nuclei may form first in the gel. Then, under suitable conditions, with these crystal nuclei as the center, the surrounding substances continuously attach to them, and the crystal slowly grows and develops, ultimately realizing the transformation from the gel state to the crystal state. The supramolecular gel constructed by the chiral organic small molecule L / D-TMPE reported in the present invention is transformed into a 3D crystal material, which mainly depends on a specific solvent system and a suitable assembly concentration. This organic small molecule cannot achieve the transformation into 3D crystals under other solvent systems and concentrations. This discovery of the present invention constructs a new chiral supramolecular material from gel to crystal, providing a new path and choice for the development and advancement of chiral supramolecular materials.

[0043] The above has detailed the present invention. For those skilled in the art, without departing from the purpose and scope of the present invention and without the need for unnecessary experiments, the present invention can be implemented within a relatively wide range under equivalent parameters, concentrations, and conditions. Although specific embodiments of the present invention are given, it should be understood that the present invention can be further improved. In summary, according to the principle of the present invention, this application intends to cover any modifications, uses, or improvements to the present invention, including those that depart from the scope disclosed in this application but are made by using conventional techniques known in the art.

Claims

1. Application of chiral organic small molecules L-TMPE or D-TMPE in the preparation of chiral supramolecular gel materials or chiral three-dimensional crystal materials; The structural formulas of the chiral organic small molecules L-TMPE and D-TMPE are as follows:

2. A chiral supramolecular gel material or a chiral three-dimensional crystal material, which is self-assembled by using the organic small molecule L-TMPE or D-TMPE described in claim 1 as an assembly unit.

3. The method for preparing the chiral supramolecular gel material or the chiral three-dimensional crystal material according to claim 2, comprising the following steps: The chiral organic small molecule L-TMPE or D-TMPE is used as an assembly unit to form the chiral supramolecular gel material with a spiral nanotube structure in a specific solvent by self-assembly; after aging, the chiral supramolecular gel material begins to collapse and transform to form the chiral three-dimensional crystal material with a hexagonal prism morphology.

4. The preparation method according to claim 3, characterized in that: The specific solvent is a DMSO-water mixed system, and the volume ratio of the two is 6:4-4:

6.

5. The preparation method according to claim 3 or 4, characterized in that: The assembly concentration of the chiral organic small molecule L-TMPE or D-TMPE is 8-30 mg / mL.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The aging time is 2 weeks or more.

7. Application of the chiral supramolecular gel material or the chiral three-dimensional crystal material according to claim 2 in drug loading, adsorption, and optical data storage and encryption.

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