Light-induced free radical luminescent compound and preparation method and application thereof

Abstract

The invention discloses a light-induced free radical luminescent compound as well as a preparation method and application thereof. The compound has a structure as shown in a formula (I). A compound shown in the formula (I) is dissolved in a mixed solvent of dichloromethane and methyl alcohol, the volume ratio of dichloromethane to methyl alcohol is 1: (1-3), the concentration of the compound shown in the formula (I) in the mixed solvent is 0.15-2 mmol / L, a clear and transparent solution is obtained, standing is conducted, a single crystal is obtained after the solvent is slowly volatilized, and the single crystal a is the light-induced free radical light-emitting flexible crystal material. # imgabs0 # (I)

Description

Technical Field

[0001] The present invention relates to a luminescent flexible material, and particularly to a photoinduced radical luminescent compound, a preparation method thereof, and an application thereof. Background Art

[0002] In recent years, due to the large steric hindrance of stable radical luminescent materials, they are not prone to recombination, dimerization and other reactions, and the theoretical exciton utilization rate can reach 100%. Such luminescent materials have relatively broad application prospects in the fields of organic light-emitting diodes, X-ray scintillators, and biological imaging.

[0003] The photoinduced radical luminescent flexible crystal material refers to a kind of material that, under illumination conditions, changes from non-luminescent to bright blue fluorescence and the fluorescence intensity increases with the increase of illumination time. Under the condition of applying stress, the photoinduced radical luminescent flexible crystal material can be bent into a ring with the increase of stress, and after removing the stress, the crystal can return to the original state without breaking. During the bending process, the original luminescent properties of the material will not change.

[0004] At present, most of the research on radical luminescent materials is focused on fluorescent probes, magnetism, etc., and there are few reports on the mechanical properties of radical luminescent materials. In particular, the flexible crystal material with photoinduced radical luminescence not only has the unique doublet state characteristics of radical molecules, but also has good mechanical properties. However, such materials are difficult to develop.

[0005] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] The object of the present invention is to provide a photoinduced radical luminescent compound, a preparation method thereof, and an application thereof. The photoinduced radical luminescent crystal material of the present invention has the characteristics of simple preparation, stable properties, high luminescence efficiency, significant color change, and bendability, and can be used in the fields of optical displays, camouflage materials, wearable sensing materials, etc.

[0007] In order to achieve the above object, the present invention provides a photoinduced radical luminescent compound, which has the structure shown in formula (Ⅰ): .

[0008] The second object of the present invention is to provide a preparation method of the photoinduced radical luminescent compound, which comprises:

[0009] Dissolve 4-methoxy-1-naphthol in sodium hydroxide solution, stir, and then add 4-bromobenzoyl chloride, and stir the reaction at low temperature, where the low temperature is 0-8 °C, to obtain the compound shown in formula (I).

[0010] Preferably, the molar ratio of 4-methoxy-1-naphthol to 4-bromobenzoyl chloride is 1: 0.3-1.8; or / and, the concentration of the sodium hydroxide solution is 10%.

[0011] Preferably, the volume ratio of the sodium hydroxide solution to the amount of substance of 4-methoxy-1-naphthol dissolved is 1-4 mmol: 3-12 mL.

[0012] Preferably, 4-methoxy-1-naphthol is dissolved in sodium hydroxide solution and stirred for 15-30 min; or / and, the time of the low-temperature stirring reaction is 1-2 h.

[0013] Preferably, after the reaction is completed, filter and wash the crude product with water, dry it, and subject the obtained crude product to silica gel column chromatography separation to obtain the compound shown in formula (I).

[0014] More preferably, the eluent used for the silica gel column chromatography separation is dichloromethane and petroleum ether with a volume ratio of 1: 2.

[0015] The third object of the present invention is to provide a photoinduced radical luminescent flexible crystal material, and the chemical structural formula of the material is as shown in formula (I);

[0016] The crystal space group of this material is Cc, and the unit cell parameters are a = 11.3851(4) Å, b = 4.6816(1) Å, c = 19.378(2) Å, α = 90°, β = 94.946(1)°, γ = 90°, Z = 4.

[0017] The fourth object of the present invention is to provide a preparation method of the photoinduced radical luminescent flexible crystal material, and the method includes: dissolving the compound shown in formula (I) in a mixed solvent of dichloromethane and methanol, where the volume ratio of dichloromethane to methanol is 1: 1-3, and the concentration of the compound shown in formula (I) in the mixed solvent is 0.15-2 mmol / L, obtaining a clear and transparent solution, standing still, and waiting for the solvent to slowly volatilize to obtain a single crystal, and this single crystal a is a photoinduced radical luminescent flexible crystal material.

[0018] The fifth object of the present invention is to provide the application of the photoinduced radical luminescent flexible crystal material in an optical display or a camouflage material.

[0019] The photoinduced radical luminescent compound, its preparation method and application of the present invention have the following advantages: (1) The photoinduced radical luminescent flexible crystal material of the present invention has few synthesis steps, high yield, is easy to generate radicals under light irradiation and has high luminescence efficiency. (2) The photoinduced radical luminescent flexible crystal material of the present invention can be bent into a ring under the condition of applying stress. After removing the stress, it returns to the original state without breaking and can emit bright blue fluorescence, which will greatly enhance the application potential of this material in the field of organic optical materials. Description of the Drawings

[0020] Figure 1 It is a photo (a) of the photoinduced radical luminescent flexible crystal material prepared by the present invention under light irradiation and a curve graph (b) of spectral changes.

[0021] Figure 2 It is a photo (a) of the photoinduced radical luminescent flexible crystal material prepared by the present invention before light irradiation under applied stress and a curve graph (b) of load changes at different displacements.

[0022] Figure 3 It is a photo (a) of the photoinduced radical luminescent flexible crystal material prepared by the present invention after light irradiation under applied stress and a curve graph (b) of load changes at different displacements. Detailed Embodiments

[0023] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that: for those not specifying specific conditions in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. For those reagents or instruments not specifying the manufacturer, they are all conventional products that can be obtained by purchasing in the market.

[0025] In the present invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents and concentrations, are only for the sake of simplicity and convenience. Accordingly, the description of the numerical range or percentage range should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0026] The features mentioned in the present invention can be combined arbitrarily as long as there is no contradiction in the combination of these features. All possible combinations should be considered as the scope described in this specification. Each feature disclosed in the specification can be replaced by any alternative feature that can provide the same, equivalent or similar purpose. Therefore, unless otherwise specified, the disclosed features are only general examples of equivalent or similar features.

[0027] The photoinduced radical luminescent compound provided by the present invention has the structure shown in formula (I):

[0028] The preparation method of the photoinduced radical luminescent compound comprises the following steps:

[0029] Dissolve 4-methoxy-1-naphthol in a sodium hydroxide solution, stir, and then add 4-bromobenzoyl chloride, and stir and react at a low temperature, the low temperature is 0-8 °C, to obtain the compound shown in formula (I).

[0030] Furthermore, the molar ratio of 4-methoxy-1-naphthol to 4-bromobenzoyl chloride is 1: 0.3-1.8.

[0031] Furthermore, the concentration of the sodium hydroxide solution is 10%.

[0032] Still further, the ratio of the volume of the sodium hydroxide solution to the amount of substance of 4-methoxy-1-naphthol dissolved is 1-4 mmol: 3-12 mL.

[0033] Furthermore, dissolve 4-methoxy-1-naphthol in a sodium hydroxide solution and stir for 15-30 min.

[0034] Furthermore, the time of stirring and reacting at a low temperature is 1-2 h.

[0035] Furthermore, after the reaction is completed, filter and wash the crude product with deionized water, dry it, and subject the obtained crude product to silica gel column chromatography separation to obtain a white solid product, that is, the compound shown in formula (I).

[0036] Still further, the eluent used for silica gel column chromatography separation is dichloromethane and petroleum ether with a volume ratio of 1: 2.

[0037] The present invention also provides a photoinduced radical luminescent flexible crystal material, and its preparation method comprises: Dissolve the compound shown in formula (I) in a mixed solvent of dichloromethane and methanol, the volume ratio of dichloromethane to methanol is 1: 1-3, and the concentration of the compound shown in formula (I) in the organic solvent is 0.15-2 mmol / L to obtain a clear and transparent solution, let it stand, and wait for the solvent to slowly volatilize to obtain single crystal a. The crystal space group of single crystal a is Cc, and the unit cell parameters are a = 11.3851(4) Å, b = 4.6816(1) Å, c = 19.378(2) Å, α = 90°, β = 94.946(1)°, γ = 90°, Z = 4. This single crystal a is the photoinduced radical luminescent flexible crystal material.

[0038] The photoinduced radical luminescent flexible crystal material prepared by the above preparation method can be applied to fields such as optical displays and camouflage materials.

[0039] The following further illustrates the technical solutions of the present invention and the obtained technical effects through Examples 1-7 and Experimental Examples 1-2 for the photoinduced radical luminescent compound provided by the present invention, its preparation method and application.

[0040] Example 1 A photoinduced radical luminescent compound, the preparation method thereof comprising: Dissolve 0.174 g (1 mmol) of 4-methoxy-1-naphthol in 3 mL of 10% sodium hydroxide solution, stir for 15 min, and then add 0.261 g (1.2 mmol) of weighed 4-bromobenzoyl chloride, and stir and react at 0 °C for 1.25 h.

[0041] After the reaction is completed, filter and wash with deionized water to obtain a crude product, and dry it in an oven. The crude product is separated by silica gel column chromatography, and the eluent is dichloromethane: petroleum ether = 1:2 (volume ratio). After the solvent is rotary evaporated under reduced pressure, 0.189 g of white solid is obtained, and the total yield is 53%. The obtained white solid is the target product photoinduced radical luminescent compound.

[0042] Dissolve the obtained white solid in a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is 1:3 to obtain a clear and transparent solution, and let it stand. Wait for the solvent to slowly volatilize to obtain single crystal a.

[0043] The NMR and mass spectrometry characterization data of the photoinduced radical luminescent compound are as follows: 1 H NMR (400 MHz, DMSO) δ 8.25 - 8.20 (m, 1H), 8.19 - 8.15 (m, 2H), 7.89 - 7.85 (m, 2H), 7.80 - 7.75 (m, 1H), 7.61 - 7.55 (m, 2H), 7.40 (d, J = 8.3 Hz, 1H), 7.02 (d, J = 8.5 Hz, 1H), 4.01 (s, 3H); 13 C NMR (200 MHz, DMSO), δ 164.92, 153.45, 139.87, 132.72, 132.34, 128.79, 128.47, 127.83, 126.52, 125.81, 122.46, 121.32, 119.02, 104.16, 56.36; HRMS (ESI, m / z) Calculated for C 18 H 13 O3Br = 356.0041, found [M] + = 356.0048。

[0044] The characterization data of single crystal a are as follows: The crystal space group is Cc, and the unit cell parameters are a = 11.3851(4) Å, b = 4.6816(1) Å, c = 19.378(2) Å, α = 90°, β = 94.946(1)°, γ = 90°, Z = 4.

[0045] Example 2 A photoinduced radical luminescent compound, whose preparation method is basically the same as that of Example 1, except that: The amount of 4-methoxy-1-naphthol used is 0.348 g (2 mmol), the amount of 10% sodium hydroxide solution used is 4 mL, and it is stirred for 25 min; the amount of 4-bromobenzoyl chloride used is 0.784 g (3.6 mmol), and after adding 4-bromobenzoyl chloride, it is stirred and reacted at 0 °C for 1.5 h.

[0046] 0.547 g of white solid was obtained, and the total yield was 76.5%. The obtained white solid is the target photoinduced radical luminescent compound, and its NMR and MS characterization data are the same as those of Example 1.

[0047] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol with a volume ratio of dichloromethane to methanol of 1:1 to obtain a clear and transparent solution, which was left standing, and single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data are the same as those of Example 1.

[0048] Example 3 A photoinduced radical luminescent compound, whose preparation method is basically the same as that of Example 1, except that: The amount of 10% sodium hydroxide solution used is 5 mL, and it is stirred for 20 min; after adding 4-bromobenzoyl chloride, it is stirred and reacted at 0 °C for 1 h.

[0049] 0.218 g of white solid was obtained, and the total yield was 61%. The obtained white solid is the target photoinduced radical luminescent compound, and its NMR and MS characterization data are the same as those of Example 1.

[0050] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol with a volume ratio of dichloromethane to methanol of 1:1.5 to obtain a clear and transparent solution, which was left standing, and single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data are the same as those of Example 1.

[0051] Example 4 A photoinduced radical luminescence compound, the preparation method of which is basically the same as that of Example 1, except that: The amount of 4-methoxy-1-naphthol used is 0.692 g (4 mmol), and the amount of 10% sodium hydroxide solution used is 12 mL; after adding 4-bromobenzoyl chloride, the reaction is stirred at 0 °C for 2 h.

[0052] 1.014 g of white solid was obtained, and the total yield was 71%. The obtained white solid is the target photoinduced radical luminescence compound, and its nuclear magnetic resonance and mass spectrometry characterization data are the same as those of Example 1.

[0053] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol was 1:2, obtaining a clear and transparent solution. After standing, single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data are the same as those of Example 1.

[0054] Example 5 A photoinduced radical luminescence compound, the preparation method of which is basically the same as that of Example 1, except that: The amount of 10% sodium hydroxide solution used is 5 mL, and it is stirred for 30 min; after adding 4-bromobenzoyl chloride, the reaction is stirred at 0 °C for 1.5 h.

[0055] 0.286 g of white solid was obtained, and the total yield was 80%. The obtained white solid is the target photoinduced radical luminescence compound, and its nuclear magnetic resonance and mass spectrometry characterization data are the same as those of Example 1.

[0056] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol was 1:3, obtaining a clear and transparent solution. After standing, single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data are the same as those of Example 1.

[0057] Example 6 A photoinduced radical luminescence compound, the preparation method of which is basically the same as that of Example 1, except that: After adding 4-bromobenzoyl chloride, the reaction is stirred at 5 °C for 1.25 h.

[0058] 0.171 g of white solid was obtained, and the total yield was 48%. The obtained white solid is the target photoinduced radical luminescence compound, and its nuclear magnetic resonance and mass spectrometry characterization data are the same as those of Example 1.

[0059] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol was 1:2.5, obtaining a clear and transparent solution. After standing, single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data are the same as those of Example 1.

[0060] Example 7 A photoinduced radical luminescent compound, whose preparation method is basically the same as that of Example 1, except that: After adding 4-bromobenzoyl chloride, the mixture was stirred at 8 °C for 1.25 h.

[0061] 0.142 g of white solid was obtained, and the total yield was 40%. The obtained white solid was the target photoinduced radical luminescent compound, and its NMR and mass spectrometry characterization data were the same as those of Example 1.

[0062] The obtained white solid was dissolved in a mixed solvent of dichloromethane and methanol with a volume ratio of dichloromethane to methanol of 1:2.5 to obtain a clear and transparent solution. After standing, single crystal a was obtained by slow evaporation of the solvent. Its single crystal characterization data were the same as those of Example 1.

[0063] Experimental Example 1 Fluorescence Intensity Test The fluorescence intensity of the photoinduced radical luminescent compound prepared in Example 1 of the present invention was tested, and the results were as Figure 1 shown in a of. The photoinduced radical luminescent compound provided by the present invention had an obvious color change. As the illumination time increased, the fluorescence intensity began to increase, from non-luminescent to bright blue fluorescence. Therefore, the color change was obvious ( Figure 1 of b).

[0064] Experimental Example 2 Mechanical Property Test The mechanical properties of the photoinduced radical luminescent flexible crystal material prepared in Example 1 of the present invention were tested, and the Young's modulus was obtained by nanoindentation test. The results were as Figure 2 shown. It could be bent into a ring under the condition of applying stress, and the Young's modulus could reach 9.14 GPa, indicating that the photoinduced radical luminescent flexible crystal material prepared by the present invention could be used in flexible displays and camouflage materials. Among them, Figure 2 was the flexible crystal before illumination. It could be bent into a ring under the condition of applying stress, and the Young's modulus could reach 9.14 GPa, Figure 3 was the flexible crystal after generating radicals by illumination. It could be bent into a ring under the condition of applying stress, and the Young's modulus could reach 9.47 GPa, indicating that illumination generated radicals but did not affect the elasticity of the photoinduced radical luminescent flexible material.

[0065] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After those skilled in the art have read the above content, various modifications and substitutions of the present invention will be obvious. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims

1. A light-induced free radical luminescent compound, characterized in that: The compound has the structure shown in formula (I): 。 2. The method for preparing a light-induced free radical luminescent compound according to claim 1, characterized in that: The method includes: Dissolve 4-methoxy-1-naphthol in sodium hydroxide solution, stir, then add 4-bromobenzoyl chloride, stir and react at low temperature, wherein the low temperature is 0-8°C, to obtain the compound represented by formula (I).

3. The preparation method according to claim 2, characterized in that: The molar ratio of the 4-methoxy-1-naphthol to the 4-bromobenzoyl chloride is 1: 0.3-1.8; Or / and, the concentration of the sodium hydroxide solution is 10%.

4. The preparation method according to claim 3, characterized in that: The ratio of the volume of the sodium hydroxide solution to the amount of the substance dissolved in 4-methoxy-1-naphthol is 1-4 mmol: 3-12 mL.

5. The preparation method according to claim 2, characterized in that: The 4-methoxy-1-naphthol is dissolved in a sodium hydroxide solution and stirred for 15 to 30 minutes; Or / and, the low temperature stirring reaction time is 1 to 2 h.

6. The preparation method according to claim 2, characterized in that: After the reaction is completed, the crude product is filtered and washed with water, dried, and the obtained crude product is separated by silica gel column chromatography to obtain the compound represented by formula (I).

7. The preparation method according to claim 6, characterized in that: The eluent used in the silica gel column chromatography separation is dichloromethane and petroleum ether in a volume ratio of 1:

2.

8. A light-induced free radical luminescent flexible crystal material, characterized in that: The chemical structure of the material is shown in formula (I); The crystal space group of this material is Cc, and the unit cell parameters are a=11.3851(4)Å, b=4.6816(1)Å, c=19.378(2)Å, α=90°, β=94.946(1)°, γ=90°, and Z=4.

9. The method for preparing the light-induced free radical luminescent flexible crystal material according to claim 8, characterized in that: The method includes: The compound represented by formula (I) is dissolved in a mixed solvent of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is 1: 1-3, and the concentration of the compound represented by formula (I) in the mixed solvent is 0.15-2 mmol / L, to obtain a clear and transparent solution. The solution is allowed to stand until the solvent evaporates slowly to obtain a single crystal, wherein the single crystal a is a light-induced free radical luminescent flexible crystal material.

10. Use of the light-induced free radical luminescent flexible crystal material as claimed in claim 8 in optical displays or camouflage materials.

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