Temperature and visible light dual-response type amphiphilic dendrimer and preparation method thereof
阅读说明：本技术 温度和可见光双重响应型双亲树形大分子及其制备方法 (Temperature and visible light dual-response type amphiphilic dendrimer and preparation method thereof ) 是由 苏新艳 张培楠 张恩泽 赵元博 葛辰伟 陶沛 刘坤 李文 张阿方 于 2021-01-11 设计创作，主要内容包括：本发明涉及温度和可见光双重响应型双亲树形大分子及其制备方法。该大分子的结构式为：其中R-1为一代或二代烷氧醚树枝化基元,R-2为C1-C9直链或者支链烷基；其中Y为氧原子时,X＝N(CH-2)-nCH-3,其中n为0～8。本发明的大分子开关由可见光进行调控。其调控方式具有多重响应性,简单,灵活等特点。因而在拓展分子开关,分子探针,环境监测,光学器件,信息存储以及智能显示等领域中的应用具有指导意义。(The invention relates to a temperature and visible light dual-response type amphiphilic dendrimer and a preparation method thereof. The macromolecule has the structural formula: wherein R is 1 Is a primary or secondary alkoxy ether dendron, R 2 Is C1-C9 straight chain or branched chain alkyl; wherein when Y is an oxygen atom, X ═ N (CH) 2 ) n CH 3 Wherein n is 0 to 8. The macromolecular switch of the invention is regulated and controlled by visible light. The regulation and control mode has the characteristics of multiple responsiveness, simplicity, flexibility and the like. Therefore, the method has guiding significance in expanding the application of the fields of molecular switches, molecular probes, environmental monitoring, optical devices, information storage, intelligent display and the like.)
1. A temperature and visible light dual response type amphiphilic tree-shaped macromolecule is characterized in that the structural formula of the macromolecule is as follows:
wherein R is1Is a primary or secondary alkoxy ether dendron, R2Is C1-C9 straight chain or branched chain alkyl; y is oxygen atom, X ═ N (CH)2)nCH3Wherein n is 0 to 8.
2. The amphiphilic dendrimer with dual responsiveness to temperature and visible light according to claim 1, wherein R in the structural formula of the compound1Comprises the following steps:
wherein the terminal group R of the alkoxy ether dendron3Me or Et.
3. A method for preparing the temperature and visible light dual-responsive amphiphilic dendrimer according to claim 1 or 2, which comprises the following steps:
a. branching elements of alkoxy ether trees with a nuclear point of-CHO and amines are mixed according to the proportion of 1: dissolving the mixture in alcohol solution in a molar ratio of 1.5, mixing and stirring the mixture for reaction for 1 hour under the catalysis of a catalytic amount of acid, adding a reducing agent under the ice bath condition, and reacting for 5 to 10 hours at room temperature; removing solvent, dissolving the residue in DCM, extracting with water, washing the organic layer with saturated sodium bicarbonate and saturated sodium chloride solution, drying, separating, purifying, and vacuum drying to obtain-NHR with nuclear point2The alkoxy ether dendron has a structural formula as follows: r1-NH-R2(ii) a The molar ratio of the alkoxy ether dendronization unit with the core point of-CHO to the reducing agent is as follows: 1: 2; the structural formula of the alkoxy ether dendronization element with the core point of-CHO is as follows: r1CHO; the structural formula of the amine is as follows: r2-NH2；
b. Dissolving the compound (1) and furfural in a molar ratio of 1:1.2 in a THF solution, stirring at room temperature for 1-3 hours, evaporating the solvent after the reaction is finished to obtain a yellow waxy solid, and extracting with DCMCollecting organic phase with anhydrous MgSO4Drying, and performing silica gel column chromatography to obtain a yellow oily product, namely, a compound (2) with a structural formula as follows:the structural formula of the compound (1) is as follows:y is oxygen atom, X ═ N (CH)2)nCH3Wherein n is 0-8;
c. the compound (2) obtained in the step b and the nuclear point obtained in the step a are-NHR2Respectively dissolving the alkoxy ether dendronized elements in a solvent according to a molar ratio of 1:1, and mixing and stirring the solution of the two compounds at room temperature for 10-20 h; and separating and purifying to obtain a purple oily product, namely the temperature and visible light dual-response amphiphilic tree-shaped macromolecule.
4. The method according to claim 3, wherein the reducing agent used in step a is: sodium cyanoborohydride, sodium borohydride, sodium triacetoxyborohydride or lithium aluminum hydride.
5. The method of claim 3, wherein the catalyst acid in step a is: glacial acetic acid, hydrochloric acid or p-toluenesulfonic acid.
Technical Field
The invention relates to a temperature and visible light dual-response type amphiphilic dendrimer and a preparation method thereof.
Background
Self-assembly of amphipathic molecules is very common in nature. Due to the excellent structural characteristics of the structure, such as high branching, terminal functional group enrichment and the like, the amphiphilic dendritic macromolecule has wide application prospects in the fields of biological medicines, molecular devices, drug slow release and the like.
Smart polymers, also known as environmentally sensitive polymers, change the physical and chemical properties of the molecule when exposed to an external stimulus (e.g., temperature, pH, light, or some field force) and transmit a detectable signal to the outside. The Polymer induces reversible or irreversible changes in molecular structure after receiving external stimulus, so that the macromolecular system changes in one or more aspects of shape, surface property, solubility and self-assembly property (Bajpai A K, Bajpai J, Saini R, Gupta R. reactive Polymers in Biology and Technology [ J ]. Polymer reviews.2011,51(1): 53-97.). In recent years, intelligent polymers are receiving attention due to wide application prospects in the fields of drug release, tissue engineering, biosensors, coatings, textiles and the like. As the research on smart materials has become more and more intensive, a single stimulation mode or simple functional output has not been able to meet the demand for a polymer material that is changing day by day. Therefore, at present, related research at home and abroad mostly relates to the development of diversified stimulation modes and functional response type materials with controllable characteristics.
External stimuli are mostly focused on temperature, pH, and light. Wherein the temperature-responsive polymer refers to a polymer that responds with temperature as an external stimulus. The variety of elements for constructing the temperature-sensitive polymer is various, and polyethylene glycol (PEG) and oligo-polyethylene glycol (OEG) have low price and good water solubility and biocompatibility, so that the elements serving as the construction elements of the temperature-sensitive compound are widely applied to various fields. However, linear PEG has a very high LCST (>80 ℃ C.), and is difficult to be practically used. In recent years, the tree-shaped PEG is effective in reducing the LCST of linear PEG due to its excellent topology. The Zhang Asang and the like have conducted exploratory research on the temperature-sensitive dendronized polymer, and the LCST of the dendronized PEG can be regulated and controlled by the hydrophilic and hydrophobic properties of the end group, the algebra of dendronized elements and the like, and has excellent temperature-sensitive performance. (Liu L, Li W, Yan J, Zhang A. thermo reactive polymeric sensors [ J ]. Journal of Polymer Science Part A: Polymer chemistry.2014,52(12):1706-13.)
Photoresponsive polymers are a new class of intelligent polymers. Because light is used as a non-contact stimulation factor, the regulation and control of the light are accurate and clean, and various new technical achievements related to the light are continuously emerged. The visible light sensitive chemical structure can perform isomerization reaction without ultraviolet light and other light with high energy, and can effectively avoid the defects that the high ultraviolet light energy easily damages healthy cells, causes degradation of biological macromolecules, influences the fatigue resistance of materials and the like. Therefore, research and development of visible light stimulus-responsive polymer systems are increasingly being emphasized.
A new class of photochromic compounds (DASAs) has recently been reported in the SemehHelmy group (Helmy S, Leibfarth FA, Oh S, Poelma JE, Hawker CJ, Read de Alaniz J. Photocurable light: a new class of organic photochromic molecules [ J ]. Journal of the American Chemical society.2014,136(23):8169-72.) for visible light response. The solution of the compound is gradually changed from purple to colorless after being irradiated by visible light, is reversibly heated and has higher fatigue resistance. The compound has mild synthesis conditions and high yield, and therefore, has great application potential.
Disclosure of Invention
The invention aims to provide a temperature and visible light dual-response type amphiphilic dendrimer.
The second purpose of the invention is to provide a preparation method of the amphiphilic dendrimer.
The synthesis of the invention is mainly divided into two parts:
(1) synthesizing alkoxy ether branching element. The main adopted method is that amines react with aldehyde groups to generate Schiff base, and then the Schiff base is reduced by a reducing agent to generate alkoxy ether dendron elements with imine groups at nuclear sites.
R1CHO+R2-NH2→R1-NH-R2
Wherein R is1Is a primary or secondary alkoxy ether dendron, R2Is C1-C9 straight chain or branched chain alkyl.
(2) Synthesizing the target amphiphilic dendrimer.
Wherein R is1Is a first or second alkoxy ether dendron with the following structural formula:
wherein the terminal group R of the alkoxy ether dendron3Me or Et.
R2Is C1-C9 straight chain or branched chain alkyl. Y ═ O, X ═ N (CH)2)nCH3Wherein n is preferably 0 to 8.
According to the reaction mechanism, the invention adopts the following technical scheme:
a temperature and visible light dual-response type amphiphilic dendrimer has the following structural formula:
wherein R is1Is a first or second alkoxy ether dendron with a structural formula as follows:
terminal group R of alcoxyl ether dendron3Me or Et; r2Is C1-C9 straight chain or branched chain alkyl; y is oxygen atom, X ═ N (CH)2)nCH3Wherein n is 0 to 8.
A temperature and visible light dual response type amphiphilic tree-shaped macromolecule is characterized in that the structural formula of the macromolecule is as follows:
wherein R is1Is a primary or secondary alkoxy ether dendron, R2Is C1-C9 straight chain or branched chain alkyl; y is oxygen atom, X ═ N (CH)2)nCH3Wherein n is 0 to 8.
R in the structural formula of the compound1Comprises the following steps:
wherein the terminal group R of the alkoxy ether dendron3Me or Et.
A method for preparing the temperature and visible light dual-response amphiphilic dendrimer is characterized by comprising the following steps:
a. branching elements of alkoxy ether trees with a nuclear point of-CHO and amines are mixed according to the proportion of 1: dissolving the mixture in alcohol solution in a molar ratio of 1.5, mixing and stirring the mixture for reaction for 1 hour under the catalysis of a catalytic amount of acid, adding a reducing agent under the ice bath condition, and reacting for 5 to 10 hours at room temperature; the solvent was removed and the residue was dissolved in DCM, extracted with water, the organic layer was washed with saturated sodium bicarbonate and saturated sodium chloride solution and driedThen, after separation and purification, vacuum drying is carried out to obtain the product with the nuclear point of-NHR2The alkoxy ether dendron has a structural formula as follows: r1-NH-R2(ii) a The molar ratio of the alkoxy ether dendronization unit with the core point of-CHO to the reducing agent is as follows: 1: 2; the structural formula of the alkoxy ether dendronization element with the core point of-CHO is as follows: r1CHO; the structural formula of the amine is as follows: r2-NH2；
b. Dissolving the compound (1) and furfural in a molar ratio of 1:1.2 in a THF solution, stirring at room temperature for 1-3 hours, evaporating the solvent after the reaction is finished to obtain a yellow waxy solid, extracting with DCM, and extracting the organic phase with anhydrous MgSO4Drying, and performing silica gel column chromatography to obtain a yellow oily product, namely, a compound (2) with a structural formula as follows:the structural formula of the compound (1) is as follows:y is oxygen atom, X ═ N (CH)2)nCH3Wherein n is 0-8;
c. the compound (2) obtained in the step b and the nuclear point obtained in the step a are-NHR2Respectively dissolving the alkoxy ether dendronized elements in a solvent according to a molar ratio of 1:1, and mixing and stirring the solution of the two compounds at room temperature for 10-20 h; and separating and purifying to obtain a purple oily product, namely the temperature and visible light dual-response amphiphilic tree-shaped macromolecule.
The reducing agent used in the step a is: sodium cyanoborohydride, sodium borohydride, sodium triacetoxyborohydride, or lithium aluminum hydride;
the catalyst acid is: glacial acetic acid, hydrochloric acid or p-toluenesulfonic acid.
Advantageous effects
1. The invention provides a method for synthesizing a temperature and visible light dual-response amphiphilic dendrimer. The synthesis method has the advantages of mild reaction conditions, high reaction efficiency and easy implementation.
2. The temperature and visible light double-response type amphiphilic tree-shaped macromolecule reported by the invention has excellent temperature-sensitive characteristics and visible light response characteristics. Overcomes the defects of high energy required by macromolecules of the traditional ultraviolet response, poor anti-fatigue property of materials and the like, and has guiding significance in the application of expanding molecular switches, molecular probes, environment monitoring, optical devices, information storage, intelligent display and other fields
Drawings
FIG. 1 is a nuclear magnetic hydrogen spectrum of Me-G1-DASA of the present invention (DMSO 20 ℃, 500MHz)
FIG. 2 is a nuclear magnetic hydrogen spectrum (CDCl) of Et-G1-DASA of the present invention3 20℃，500MHz)
FIG. 3 shows the chemical formula of the visible light isomerization reaction of Me-G1-DASA of the present invention. Under the action of visible light, the color of the dendrimer solution is gradually changed from purple to colorless, and the dendrimer solution can be changed from colorless to purple under the dark or heating condition, and the reversible process has solvent dependence.
FIG. 4 is a turbidity curve of an aqueous solution of Me-G1-DASA of the present invention at a concentration of 0.25 Wt%.
FIG. 5 shows the concentration of the present invention at 1 x 10-5The absorbance of the Me-G1-DASA solution at the position of 558nm gradually decreases along with the time change under the visible light irradiation.
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the scope of the present invention in any way. The invention utilizes1The H NMR method is used for representing the structure of the target macromolecule, and an ultraviolet visible spectrometer is used for representing the characteristics of light response and temperature response of the target macromolecule. In all the examples, the silica gel used for separation was not illustrated to be 200-300 mesh.
Example 1:
1. the invention relates to synthesis of N- (3,4,5-tris (2- (2- (2-methoxy) ethoxy) ethoxy) benzyl) ethanamine (M e-G1-NH-Et) with imine as core point, namely synthesis of alkoxy ether branching motif Me-G1-NH-Et: the compound Me-G1-CHO (1G,1.69mmol) was dissolved in a solution of ethylamine in methanol (1.69mL,3.38mmol) and reacted with mixing and stirring at 30 ℃ for 4 hours under the catalysis of glacial acetic acid. Under the condition of ice bathSodium borohydride (0.32g,5.07mmol) was added and the reaction was allowed to warm slowly to 30 ℃ for 8 hours. After the reaction, methanol was evaporated to dryness, and the residue was dissolved in DCM and extracted with water. The organic layer was washed with saturated sodium bicarbonate and saturated sodium chloride solution, and the organic layer was anhydrous MgSO4And (5) drying. Silica gel column chromatography (DCM: methanol 20:1) was used. Me-G1-NH-Et (58%) was obtained as a pale yellow oil.
2. The present invention relates to the synthesis of compound (2)
Dissolving the compound (1) and furfural in THF, stirring at room temperature for 2 hours, and evaporating the solvent after the reaction is finished to obtain a yellow solid. Extracting with DCM, and extracting the organic phase with anhydrous MgSO4Drying, adopting column chromatography and vacuum drying to obtain the final product.
The invention relates to a synthesis method of temperature and light double-response type amphiphilic dendrimer Me-G1-DASA for synthesizing 5- ((2Z,4E) -5- (ethyl (3,4,5-tris (2- (2-methoxy) ethoxy) ethoxy) be nyl) amino) -2-hydroxypenta-2, 4-dien-1-ylidine) -1, 3-diacetylpyrimide-2, 4,6(1H,3H,5H) -trione (Me-G1-DASA): compound (2) (200mg,0.45mmol) and compound Me-G1-NH-Et (600mg, 0.96mmol) were dissolved in 5mL of dichloromethane, and the solutions were stirred at room temperature for 3 hours under exclusion of light. Performing silica gel column chromatography (DCM: CH)3OH 40:1) finally yielded the product as a purple oil (67%).1H NMR(d6-DMSO):δ＝0.83(t, 6H,CH3),1.23(m,20H,CH2),1.48(m,4H,CH2),1.1(t,3H,CH3),3.2(m, 9H,CH3),3.48-3,74(m,36H,CH2),4.0-1.4(m,6H,CH2),4.65-4.76(d,2H, CH2),6.1(m,H,CH),6.59(s,H,CH)，6.74-6.76(m,2H,CH),7.16(m, H,CH),8.17(m,H,CH),12.5(m,H,CH)。
Example 2:
1. the invention relates to synthesis of N- (3,4,5-tris (2- (2- (2-ethoxymethoxy) ethoxy) ethoxy) benzyl) ethanamine (Et-G1-NH-Et) with imine core point as alkoxy ether branching motif Et-G1-NH-Et: experimental procedure Synthesis of the Compound Me-G1-NH-Et in example 1 gave Et-G1-NH-Et as a pale yellow oil (62%).
2. The invention relates to a temperature and light dual-response typeSynthesis of dendrimer Et-G1-DASA Synthesis of 5- ((2Z,4E) -5- (ethyl (3,4,5-tris (2- (2- (2-ethoxymethoxy) ethoxy) ethoxy) ben zyl) amino) -2-hydroxypenta-2, 4-dien-1-ylidine) -1, 3-dioctypyrimide-2, 4,6(1H,3H,5H) -trione (Et-G1-DASA): experimental procedure the synthesis of the compound Me-G1-DASA of example 1 gave the product as a purple oil (58%). Et-G1-DASA:1H NMR(CDCl3):δ＝0.86(t,6H,CH3),1.20(m,12H,CH2),1.26(m,24H,CH2),1.11(t,3H, CH3),3.50(m,6H,CH2),3.52-4.00(m,36H,CH2),4.00-4.10(m,6H,CH2), 4.48-4.51(d,2H,CH2),5.30(s,H,CH),6.50(s,2H,CH)，6.72(s,H,CH), 7.00(s,H,CH),7.16(s,H,CH)。
example 3
The invention relates to a temperature-sensitive experiment of a temperature and light double-response type amphiphilic dendrimer Me-G1-DASA, which dissolves the molecule in water with the concentration of 2.5 wt%. The molecule is clear and purple at room temperature, and the solution becomes turbid when heated to a temperature above the phase transition temperature. When the temperature is reduced to room temperature, the solution returns to a clear state, and the purple color of the solution is lightened due to the conversion of the conjugated structure of the molecules to the ionic structure in the heating process. See in particular fig. 4.
Example 4
The invention relates to a visible light sensitive experimental preparation concentration of 1 x 10 for a temperature and light double-response type amphiphilic dendrimer Me-G1-DASA-5The maximum absorption wavelength of the ultraviolet absorption spectrum of the aqueous solution of mol/LMe-G1-DASA is 558 nm. And the absorbance at that wavelength gradually decreases with irradiation of visible light. The solution gradually changed in color from purple to colorless. From this, it is known that the molecule gradually changes from a conjugated, hydrophobic structure to an ionic, hydrophilic structure under irradiation of visible light. See in particular fig. 5.