Diaryl ethylene polymer as well as preparation method and application thereof

Abstract

The invention discloses a diarylethene polymer, the structure of which is shown as (formula 1), n is an integer of 2-20, R1 is independently an H or F atom, R2 is independently a substituted or unsubstituted aryl group, and # imgabs0 # represents a cis-trans isomer form. The invention also discloses a preparation method of the diarylethene polymer, which comprises the following steps: under the protection of inert gas, carrying out click polymerization on a binary alkynyl compound and a binary sulfydryl compound in an organic solvent at the temperature of 20-50 DEG C for 1-4 hours; the molar ratio of the binary alkynyl compound to the binary sulfydryl compound is 1: (1-1.1); and (2) after the reaction is finished, dissolving the product in an organic solvent, then adding into n-hexane, precipitating, collecting the precipitate, and drying to constant weight to obtain the diarylethene polymer. The preparation method disclosed by the invention is efficient, mild in condition, simple and easy to implement and good in atom economy, and the obtained diarylethene polymer can be applied to anti-counterfeiting and copying materials. # imgabs1 #

Description

Technical Field

[0001] The invention relates to the technical field of photochromic polymers, and in particular to a diarylethene polymer and a preparation method and application thereof. Background Art

[0002] The regulation of the physical properties of materials by external stimuli is crucial to the development of molecular devices. Photochromic compounds are the most popular type of molecular switches, which can use light to achieve rapid and local control of molecules without causing physical and chemical reactions in the surrounding sensitive environment. Among them, diarylethene (DTE) molecules show excellent photochromic properties, excellent fatigue resistance and good thermal stability in solution, solid and crystal, and are favored by scientists. This type of molecule will cause changes in electronic properties and topological structures during dynamic transformation, and has very attractive application prospects in waveguides, information storage and optoelectronics. In order to develop these small molecule compounds into practical photoresponsive functional materials, they are usually doped with polymers to give the materials good processing properties. However, the doped materials still have deficiencies such as uneven doping, small molecule aggregation, and precipitation. Based on this, it is undoubtedly a better choice to introduce DTE motifs into the polymer skeleton by covalent bonding.

[0003] Most of the synthetic methods reported so far for polymers containing DTE moieties have problems such as cumbersome synthesis and harsh conditions, and the resulting products have poor stability. Therefore, developing a simple and efficient polymerization method to introduce DTE into polymers to prepare diarylethene polymers with excellent photochromic properties has important scientific significance and application value. Summary of the invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a diarylethene polymer, the structure of which is shown in (Formula 1):

[0005]

[0006] In Formula 1, n is an integer of 2 to 20, and R 1 Each of the atoms R is independently H or F. 2 is independently substituted or unsubstituted aryl, Represents cis-trans isomeric forms.

[0007] Preferably, the R 2 Any one of the following chemical structural formulas 1 to 6:

[0008]

[0009] Here, * indicates the substitution position.

[0010] Specifically, the diarylethene polymer is one of the following specific polymers:

[0011]

[0012] Wherein, n is an integer from 2 to 20, Represents cis-trans isomeric forms.

[0013] Another object of the present invention is to provide a method for preparing a diarylethene polymer, which is simple, efficient, mild and capable of synthesizing a polymer with a relatively high molecular weight. The method comprises the following steps:

[0014] (1) Under the protection of an inert gas, a dibasic alkynyl compound and a dibasic thiol compound are subjected to click polymerization in an organic solvent, the polymerization reaction temperature is 20 to 50° C., and the reaction time is 1 to 4 hours; the molar ratio of the dibasic alkynyl compound to the dibasic thiol compound is 1:(1 to 1.1);

[0015] (2) After the reaction is completed, the product is dissolved in an organic solvent, and then added to n-hexane for precipitation, the precipitate is collected, and dried to constant weight to obtain a diarylethene polymer (Formula 1);

[0016]

[0017] The general structural formula of the dibasic alkynyl compound is shown in (Formula 2),

[0018]

[0019] The binary thiol compound is shown in (Formula 3),

[0020] HS-R 2 -SH (Formula 3)

[0021] In (Formula 1), n ​​is an integer of 2 to 20, and in (Formula 1) to (Formula 3), R 1 Each of the atoms R is independently H or F. 2 is independently substituted or unsubstituted aryl, Represents cis-trans isomeric forms.

[0022] Specifically, the R 2 Any one of the following chemical structural formulas 1 to 6:

[0023]

[0024] Preferably, the organic solvent is at least one of tetrahydrofuran, toluene, dimethyl sulfoxide and N,N-dimethylformamide.

[0025] Preferably, the concentration of the dibasic alkynyl compound in the organic solvent is 0.025-0.1 mol / L.

[0026] Another object of the present invention is to provide applications of the above diarylethene polymer, specifically applications in anti-counterfeiting and copying materials.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] 1. The diarylethene polymer disclosed in the present invention has good film-forming properties, is easy to process, and can be directly made into a film for application.

[0029] 2. The diarylethene polymer disclosed in the present invention has excellent photochromic properties and can quickly achieve closed-loop / open-loop response under alternating irradiation of ultraviolet light / visible light; and has excellent anti-fatigue performance.

[0030] 3. The preparation method disclosed in the present invention has the advantages of mild conditions, simple process, high polymerization efficiency, etc., and a high-yield, high-molecular-weight polymer can be obtained by reacting at 30° C. for only 2 hours.

[0031] 4. The polymerization process of the present invention generates no by-products and is atom-economical.

[0032] 5. The diarylethene polymer obtained by the present invention can be applied to anti-counterfeiting and copying materials, further expanding the application field and scope of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The diarylethene polymer P1 and its corresponding monomer in CDCl 3 H NMR spectrum of .

[0034] Figure 2 This is the ultraviolet absorption spectrum of the diarylethene polymer P1 solution after ultraviolet light irradiation.

[0035] Figure 3 This is a graph showing the change in the absorption value of diarylethene polymer P1 at 635nm under alternating irradiation of ultraviolet light and visible light.

[0036] Figure 4 It is an anti-counterfeiting material model of diarylethene polymer P1.

[0037] Figure 5 It is a replica material model of diarylethene polymer P1. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0039] Example 1

[0040] M1 and M2 were subjected to click polymerization reaction under non-catalytic conditions to prepare diarylethene polymer P1.

[0041]

[0042] Among them, monomer M1 was synthesized according to the synthesis method in the published literature (Macromolecules, 2012, 45, 7692; Chem. An Asian J., 2013, 9, 104; Polym. Chem., 2014, 5, 2301); M2 was purchased from Anage Company.

[0043] 41.6 mg (0.1 mmol) of monomer M1 and 25.0 mg (0.1 mmol) of monomer M2 were added to a 10 mL polymerization tube, and the vacuum was replaced with nitrogen three times. 2 mL of ultra-dry tetrahydrofuran (THF) was injected with a syringe. After the monomer was completely dissolved, it was placed in an oil bath pot that was kept constant at 30°C and reacted for 2 hours. After the reaction was completed, 1 mL of THF was added, and the obtained polymer solution was added dropwise to 60 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain a diarylethene polymer P1. After measurement and analysis, the yield of the product P1 was 71%, the weight average molecular weight was 7100, and the molecular weight distribution was 1.49 (the molecular weight and molecular weight distribution were determined by an ultra-high performance polymer chromatography system (GPC) equipped with a diode array detector. THF was used as the mobile phase, the flow rate was 0.5 mL / min, and linear monodistributed polystyrene (PS) was used as the standard for calibration).

[0044] The H NMR spectra of diarylethene polymer P1 and its corresponding monomer (* represents solvent peak) are shown in Figure 1 .from Figure 1 C shows that the alkyne hydrogen peak at a chemical shift of 3.35 ppm and the thiol peak at a chemical shift of 3.45 ppm disappear, and hydrogen peaks of different cis and trans isomers of olefins appear at chemical shifts of 6.33-7.08 ppm; the above results indicate that the monomers are completely reacted to obtain diarylethene polymer P1.

[0045] Example 2

[0046] Photochromic properties of diarylethene polymer P1.

[0047] The open-ring diarylethene polymer (P1-O) will turn into a closed-ring diarylethene polymer (P1-C) under ultraviolet light. Figure 2The photochromic properties of the polymer shown in the figure show that P1-O has almost no absorption in the visible light region above 400nm, and its THF solution is basically colorless. After irradiation with ultraviolet light, the diaryl vinyl units undergo a ring-closing reaction, changing from an open-ring state to a closed-ring state, with obvious absorption at a wavelength of about 630nm, and its THF solution turns dark green. When irradiated with visible light, the closed-ring diaryl vinyl will undergo a ring-opening reaction to become an open-ring state, and the color of the polymer solution will also return to its original colorless state. In the thin film state of polymer P1, photochromic phenomena similar to those in the solution can also be observed.

[0048] Example 3

[0049] Photochromic and anti-fatigue properties of diarylethene polymer P1.

[0050] In view of the good film-forming properties of the polymer, a film of polymer P1 was prepared by spinning, and its photochromic anti-fatigue properties were investigated. Figure 3 As shown in the figure, the polymer film was irradiated with 365nm ultraviolet light for 1 minute, and then irradiated with visible light greater than 550nm for 15 minutes, and the change of the absorption value at 635nm was monitored. The results show that after 10 repeated cycles, the absorption value at 635nm still did not drop significantly, indicating that polymer P1 has excellent fatigue resistance.

[0051] Example 4

[0052] Anti-counterfeiting material model of diarylethene polymer P1.

[0053] Figure 4 The THF solution of diarylethene polymer P1 is used to write "SCUT" on a silica gel plate using a capillary. When the concentration is very low, basically no words can be seen on the silica gel plate; after irradiation with 365nm ultraviolet light, the open-ring diarylethene is transformed into a closed-ring state, the font color turns light green, and the information is revealed. When irradiated with visible light with a wavelength greater than 550nm for a period of time, the diarylethene unit is transformed from a closed-ring state to an open-ring state, and the font color disappears. It can be seen that the color of the text can be reversibly read and erased by ultraviolet / visible light irradiation, so the diarylethene polymer P1 can be well used in anti-counterfeiting labels.

[0054] Example 5

[0055] Replica material model of diarylethene polymer P1.

[0056] like Figure 5As shown, first, the THF solution of polymer P1 is sprayed on the filter paper, and the apparent color does not change, but it emits dark green fluorescence under ultraviolet light; then, after irradiating the mold and ultraviolet light for 5 minutes, the "kitten" pattern appears under fluorescent light; then, the pattern information is erased using visible light; the mold and ultraviolet light are irradiated for 5 minutes again to "write" and obtain the "puppy" pattern; this cycle is repeated to achieve the erasable operation of information. This conceptual demonstration of erasable patterns shows the potential application of diarylethene polymers as media in the fields of carbon printing and optical storage.

[0057] Example 6

[0058] M3 and M2 were subjected to click polymerization reaction under non-catalytic conditions to prepare diarylethene polymer P2.

[0059] Among them, monomer M3 was synthesized according to the synthesis method in the published literature (Macromolecules, 2012, 45, 7692; Chem. An Asian J., 2013, 9, 104; Polym. Chem., 2014, 5, 2301); M2 was purchased from Anage Company.

[0060]

[0061] Add 30.8mg (0.1mmol) of monomer M3 and 25.0mg (0.1mmol) of monomer M2 to a 10mL polymerization tube, evacuate and replace nitrogen three times, inject 2mL of ultra-dry THF with a syringe, and after the monomer is completely dissolved, put it into an oil bath pot that has been kept constant at 30°C and react for 2 hours. After the reaction is completed, add 1mL of THF, and add the obtained polymer solution dropwise to 60mL of vigorously stirred n-hexane, let it stand, filter, and dry to obtain diarylethene polymer P2. After measurement and analysis, the yield of product P2 is 65%, the weight average molecular weight is 6900, and the molecular weight distribution is 2.02 (the molecular weight and molecular weight distribution are determined by GPC equipped with a diode array detector. THF is used as the mobile phase, the flow rate is 0.5mL / min, and linear monodistributed PS is used as the standard for calibration).

[0062] Example 7

[0063] M1 and M4 were subjected to click polymerization reaction under non-catalytic conditions to prepare diarylethene polymer P3.

[0064] The monomer M1 was synthesized according to the synthesis method in the published literature (Macromolecules, 2012, 45, 7692; Chem. An Asian J., 2013, 9, 104; Polym. Chem., 2014, 5, 2301); M4 was purchased from TCI.

[0065]

[0066] 41.6 mg (0.1 mmol) of monomer M1 and 14.2 mg (0.1 mmol) of monomer M4 were added to a 10 mL polymerization tube, and the vacuum was replaced with nitrogen three times. 2 mL of ultra-dry THF was injected with a syringe. After the monomer was completely dissolved, it was placed in an oil bath pot that was kept constant at 30°C and reacted for 2 hours. After the reaction was completed, 1 mL of THF was added, and the obtained polymer solution was added dropwise to 60 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain a diarylethene polymer P3. After measurement and analysis, the yield of the product P3 was 78%, the weight average molecular weight was 7500, and the molecular weight distribution was 1.62 (the molecular weight and molecular weight distribution were determined by GPC equipped with a diode array detector. THF was used as the mobile phase, the flow rate was 0.5 mL / min, and the linear monodistributed PS was used as the standard for calibration).

[0067] Example 8

[0068] M1 and M5 were subjected to click polymerization reaction under non-catalytic conditions to prepare diarylethene polymer P4.

[0069] The monomer M1 was synthesized according to the synthesis method in the published literature (Macromolecules, 2012, 45, 7692; Chem. An Asian J., 2013, 9, 104; Polym. Chem., 2014, 5, 2301); M5 was purchased from TCI.

[0070]

[0071] 41.6 mg (0.1 mmol) of monomer M1 and 14.2 mg (0.1 mmol) of monomer M5 were added to a 10 mL polymerization tube, and the vacuum was replaced with nitrogen three times. 2 mL of ultra-dry THF was injected with a syringe. After the monomer was completely dissolved, it was placed in an oil bath pot that was kept constant at 30°C and reacted for 2 hours. After the reaction was completed, 1 mL of THF was added, and the obtained polymer solution was added dropwise to 60 mL of vigorously stirred n-hexane, allowed to stand, filtered, and dried to obtain a diarylethene polymer P4. After measurement and analysis, the yield of the product P4 was 78%, the weight average molecular weight was 7200, and the molecular weight distribution was 1.95 (the molecular weight and molecular weight distribution were determined by GPC equipped with a diode array detector. THF was used as the mobile phase, the flow rate was 0.5 mL / min, and the linear monodistributed PS was used as the standard for calibration).

[0072] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A diarylethene polymer, characterized in that The structure is shown in (Formula 1): In Formula 1, n is an integer of 2 to 20, and R 1 Each of the atoms is independently H or F, R 2 is independently substituted or unsubstituted aryl, Represents cis-trans isomeric forms.

2. The diarylethene polymer according to claim 1, characterized in that The R 2 Any one of the following chemical structural formulas 1 to 6: Here, * indicates the substitution position.

3. The diarylethene polymer according to claim 1, characterized in that One of the following specific polymers: Wherein, n is an integer from 2 to 20, Represents cis-trans isomeric forms.

4. A method for preparing a diarylethene polymer according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Under the protection of an inert gas, a dibasic alkynyl compound and a dibasic thiol compound are subjected to click polymerization in an organic solvent, the polymerization reaction temperature is 20 to 50° C., and the reaction time is 1 to 4 hours; the molar ratio of the dibasic alkynyl compound to the dibasic thiol compound is 1:(1 to 1.1); (2) After the reaction is completed, the product is dissolved in an organic solvent, and then added to n-hexane for precipitation, the precipitate is collected, and dried to constant weight to obtain a diarylethene polymer (Formula 1); The general structural formula of the dibasic alkynyl compound is shown in (Formula 2), The binary thiol compound is shown in (Formula 3), HS-R 2 -SH (Formula 3) In (Formula 1), n ​​is an integer of 2 to 20, and in (Formula 1) to (Formula 3), R 1 Each of the atoms is independently H or F, R 2 is independently substituted or unsubstituted aryl, Represents cis-trans isomeric forms.

5. The method for preparing a diarylethene polymer according to claim 4, characterized in that: The R 2 Any one of the following chemical structural formulas 1 to 6:

6. The method for preparing a diarylethene polymer according to claim 4, characterized in that: The organic solvent is at least one of tetrahydrofuran, toluene, dimethyl sulfoxide and N,N-dimethylformamide.

7. The method for preparing a diarylethene polymer according to claim 4, characterized in that: The concentration of the dibasic alkynyl compound in the organic solvent is 0.025-0.1 mol / L.

8. Use of the diarylethene polymer according to any one of claims 1 to 3 in anti-counterfeiting and copying materials.

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