Benzoic acid host-guest phosphorescent compound as well as preparation method and application thereof

Abstract

The invention provides a benzoic acid host-guest phosphorescent compound as well as a preparation method and application thereof, and belongs to the technical field of organic materials. Benzoic acid and derivatives thereof and macrocyclic host cyclodextrin (alpha / beta / gamma-CD) are simply ground, and host-guest interaction and hydrogen bond interaction are utilized to obtain the benzoic acid host-guest phosphorescent compound which has a phosphorescent phenomenon and long afterglow time, can stably exist in air for a long time, and is non-toxic and environment-friendly. The macrocyclic main body cyclodextrin and benzoic acid and derivatives thereof can be commercially purchased, have the advantages of low cost, easiness in obtaining, no toxicity and the like, are simple, convenient and efficient to prepare, and are safer and more environment-friendly. The benzoic acid host-guest phosphorescent compound provided by the invention has good solubility and no toxicity, and can be used as an anti-counterfeiting encryption material with excellent performance to be applied to encryption and counterfeiting prevention of foods and medicines.

Description

Technical Field

[0001] The invention relates to the technical field of organic materials, and in particular to a benzoic acid host-guest phosphorescent composite and a preparation method and application thereof. Background Art

[0002] Organic room temperature phosphorescence (RTP) has unique fluorescent properties. Its luminous efficiency is higher than that of fluorescent materials. If it is prepared into a light-emitting diode, the luminous efficiency can be increased three times that of fluorescent materials. Therefore, the application of RTP materials in organic light-emitting diodes (OLEDs), bio-imaging, anti-counterfeiting and encryption has also become a major research hotspot.

[0003] However, the realization of ultralong room temperature phosphorescence requires that excitons go from singlet to triplet excited states through intersystem crossing and return to the ground state in a slow non-radiative relaxation process. Therefore, in order to obtain efficient RTP materials, the non-radiative transition of triplet excitons can be suppressed by manipulating intermolecular interactions, such as crystal engineering, host-guest assembly, h-aggregation, polymerization, and self-assembly, thereby obtaining efficient RTP materials. In addition, molecular engineering can be performed, such as introducing heavy atoms (Br, I, etc.), heteroatoms (N, O, S, etc.), or carbonyl groups into the molecular skeleton to enhance ISC, which is very important for the filling of triplet excitons.

[0004] At present, the method based on the interaction between macrocyclic host molecules and guest molecules has attracted wide attention due to its inherent advantages such as simple material preparation, low cost, diverse molecular structure resources and controllable modulation. In particular, the amorphous state of the host-guest RTP material system makes its practical application in production highly feasible. The macrocyclic host molecules can not only fix the phosphorescent guests and provide them with a rigid microenvironment to limit molecular vibration, but also protect them from oxygen quenching.

[0005] Food and drug anti-counterfeiting is of great significance for protecting the legitimate interests of consumers and patients, encouraging scientific research enterprises to invent and create, and maintaining a fair market environment. Therefore, the development of anti-counterfeiting encryption materials that can be used for food and drugs has important economic value and social significance. Summary of the invention

[0006] The purpose of the present invention is to provide a benzoic acid host-guest phosphorescent complex and a preparation method and application thereof, and to utilize host-guest interaction and hydrogen bond interaction to obtain a benzoic acid host-guest phosphorescent complex that has both phosphorescence and a long afterglow time, can stably exist in the air for a long time, is non-toxic, and is environmentally friendly, and is used as a type of anti-counterfeiting material for encryption and anti-counterfeiting of food and medicine.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a benzoic acid host-guest phosphorescent complex, which is prepared by host-guest complexation of a macrocyclic host cyclodextrin with benzoic acid and its derivatives, and the structure of the benzoic acid host-guest phosphorescent complex is shown in formula (I):

[0009]

[0010] Preferably, the molar ratio of the macrocyclic host cyclodextrin to benzoic acid and its derivatives in the benzoic acid host-guest phosphorescent complex is 1 to 1000:1.

[0011] Preferably, the structural formula of the benzoic acid and its derivatives is as follows:

[0012]

[0013] The benzoic acid and its derivatives include one of the following compounds: benzoic acid, p-aminobenzoic acid, 4-methylaminobenzoic acid, 4-dimethylaminobenzoic acid, 4-(N,N-diethylamino)-benzoic acid, 4-aminobenzoic acid methyl ester, p-aminobenzenesulfonic acid, aminobenzoic acid hydrochloride, 4-dimethylaminobenzoic acid hydrochloride, 4-(1-pyrrolidinyl)benzoic acid, p-hydroxybenzoic acid, terephthalic acid, p-chlorobenzoic acid, p-bromobenzoic acid, p-iodobenzoic acid , p-methoxybenzoic acid, p-methylthiobenzoic acid, p-acetamidobenzoic acid, 2-naphthoic acid, 2-anthracenecarboxylic acid, m-aminobenzoic acid, 3,4-diaminobenzoic acid, 4-amino-3-hydroxybenzoic acid, 3-chloro-4-benzoic acid, 1-pyrenecarboxylic acid, 4-amino-3-bromobenzoic acid, phthalic acid, isophthalic acid, 3,5-diaminobenzoic acid, s-tribenzoic acid, 4-hydroxypyridine, 4-phenylpyridine, 4-(pyridin-4-yl)aniline;

[0014] The macrocyclic main body cyclodextrin includes one of cyclodextrin α-CD, β-CD, and γ-CD, which correspond to the following structures respectively:

[0015]

[0016] On the one hand, the present invention also provides a method for preparing the above-mentioned benzoic acid host-guest phosphorescent complex, wherein the prepared product is a phosphorescent complex solid material, and the preparation method comprises the following steps:

[0017] Benzoic acid and its derivatives are used as guests, and macrocyclic host cyclodextrin α / β / γ-CD is used as the main body. The mixture is mixed according to a set ratio, and water is added and ground to obtain a benzoic acid host-guest phosphorescent composite solid material.

[0018] As another embodiment of preparing a solid material, the present invention provides the above-mentioned benzoic acid host-guest phosphorescent complex, and the prepared product is a phosphorescent complex solid material. The preparation method comprises the following steps:

[0019] Taking benzoic acid and its derivatives as guests and macrocyclic main body cyclodextrin α / β / γ-CD as main body, the macrocyclic main body cyclodextrin is dissolved in water according to a set ratio to obtain a cyclodextrin aqueous solution, the benzoic acid and its derivatives are dissolved in an organic solvent to obtain a saturated solution of benzoic acid and its derivatives, the saturated solution of benzoic acid and its derivatives is added dropwise into the cyclodextrin aqueous solution while stirring, ultrasonically mixed, and dried to obtain a benzoic acid host-guest phosphorescent complex solid material.

[0020] On the other hand, the present invention also provides a method for preparing the above-mentioned benzoic acid host-guest phosphorescent complex, wherein the prepared product is a phosphorescent complex crystal material, and the preparation method comprises the following steps:

[0021] Taking benzoic acid and its derivatives as the guest, and macrocyclic main body cyclodextrin α / β / γ-CD as the main body, according to the set ratio, the macrocyclic main body cyclodextrin is dissolved in water to obtain a cyclodextrin aqueous solution, and the benzoic acid and its derivatives are dissolved in an organic solvent to obtain a saturated solution of benzoic acid and its derivatives;

[0022] A saturated solution of benzoic acid and its derivatives is added dropwise to a cyclodextrin aqueous solution while stirring, and the mixture is reacted at 45-60°C for 4-6 hours. The mixture is then cooled to room temperature, and an appropriate amount of water is added to the filtrate. The mixture is allowed to stand at room temperature until colorless crystals are generated. The generated precipitate is filtered, and the crude product is dissolved in hot water to prepare a saturated solution. The solution is cooled to room temperature and the precipitated solid is filtered off. An appropriate amount of water is then added to the filtrate. The mixture is allowed to stand at room temperature until colorless crystals are generated, thereby obtaining a benzoic acid host-guest phosphorescent complex crystal material.

[0023] As another embodiment of preparing the crystalline material, the present invention also provides a method for preparing the above-mentioned benzoic acid host-guest phosphorescent complex, and the prepared product is a phosphorescent complex crystalline material, and the preparation method comprises the following steps:

[0024] Benzoic acid and its derivatives are used as guests, and the macrocyclic host cyclodextrin α / β / γ-CD is used as the main body. They are mixed according to a set ratio, ground with water, slowly added with water, and ultrasonicated to reach saturated concentration. Then an appropriate amount of water is added, and the mixture is filtered and transferred to different vials. The mixture is allowed to stand at room temperature to generate colorless crystals. The organic solvent is allowed to slowly diffuse into the solution within a week, and colorless crystals are generated, thereby obtaining a benzoic acid host-guest phosphorescent complex crystal material.

[0025] As another embodiment of preparing the crystalline material, the present invention also provides a method for preparing the above-mentioned benzoic acid host-guest phosphorescent complex, and the prepared product is a phosphorescent complex crystalline material, and the preparation method comprises the following steps:

[0026] Benzoic acid and its derivatives are used as guests, and macrocyclic host cyclodextrin α / β / γ-CD is used as the main body, mixed according to a set ratio, ground with water, dissolved in a solvent, heated at 80-110° C. for 2-4 hours, then slowly cooled to room temperature, added a proper amount of water to the filtrate, allowed to stand at room temperature, colorless crystals are generated, the generated precipitate is filtered, the crude product is dissolved in hot water to prepare a saturated solution, cooled to room temperature, filtered to remove the precipitated solid, then added a proper amount of water to the filtrate, allowed to stand at room temperature, colorless crystals are generated, and a benzoic acid host-guest phosphorescent complex crystal material is obtained;

[0027] The solvent is water or a mixture of water and an organic reagent, the volume ratio of water to the organic reagent in the mixture of water and organic reagent is 2:1, and the organic reagent is one of acetonitrile, isopropanol, N,N-dimethylformamide, and dimethyl sulfoxide.

[0028] Preferably, the organic solvent is one of methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide.

[0029] In addition, the standing time mentioned above is 0 to 3 weeks.

[0030] The present invention also provides an application of the benzoic acid host-guest phosphorescent complex prepared by the above-mentioned benzoic acid host-guest phosphorescent complex or any preparation method of the benzoic acid host-guest phosphorescent complex in food and medicine encryption and anti-counterfeiting.

[0031] The beneficial effects of the present invention compared with the prior art are:

[0032] (1) The present invention uses cyclodextrin (α / β / γ-CD) as a macrocyclic host molecule (H), benzoic acid and its derivatives (G) as phosphorescent guest molecules, and effectively combines with organic phosphorescent guest molecules by utilizing host-guest interaction and hydrogen bond interaction, thereby obtaining an all-organic room temperature phosphorescent material that has both phosphorescence and a long afterglow time and can stably exist in the air for a long time, that is, a benzoic acid host-guest phosphorescent complex. Among them, the macrocyclic host cyclodextrin and benzoic acid and its derivatives are both commercially available, the preparation of the phosphorescent complex is simple and efficient, the phosphorescent performance is good, and it has bright blue light emission, which is expected to solve the problem of low-cost and efficient preparation of phosphorescent materials.

[0033] (2) The application of the environmentally friendly benzoic acid host-guest phosphorescent complex of the present invention provides valuable inspiration for the further development of pharmaceutical, food, cosmetic processing and biotechnology fields due to the good solubility and non-toxicity of the host-guest system, and also provides a new method for developing safer and more environmentally friendly materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 Schematic diagram of the application of benzoic acid host-guest phosphorescent complex NH@α-CD in food and medicine encryption in Example 1;

[0036] Figure 2 This is a photo of the luminescence of the benzoic acid host-guest phosphorescent complex NH@α-CD in Example 1;

[0037] Figure 3 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex NH@α-CD in Example 2 with a molar ratio of 1 to 1000:1;

[0038] Figure 4 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex NH@β-CD in Example 3;

[0039] Figure 5 The luminescence photographs of the benzoic acid host-guest phosphorescent complex NH@β-CD in Example 3 with a molar ratio of 1 to 1000:1;

[0040] Figure 6 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex NH@γ-CD in Example 3;

[0041] Figure 7 This is the luminescence photo of the benzoic acid host-guest phosphorescent complex NMH@α-CD in Example 5;

[0042] Figure 8 This is the luminescence photo of the benzoic acid host-guest phosphorescent complex NMMH@α-CD in Example 6;

[0043] Fig. 9 This is the luminescence photo of the benzoic acid host-guest phosphorescent complex ACNH@α-CD in Example 7;

[0044] Fig.10 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex NM@α-CD in Example 8;

[0045] Fig.11 This is a luminescent photo of the benzoic acid host-guest phosphorescent complex PYH@α-CD in Example 9;

[0046] Fig.12 This is the luminescence photograph of the benzoic acid host-guest phosphorescent complex OHH@α-CD in Example 10;

[0047] Fig.13 This is the luminescence photograph of the benzoic acid host-guest phosphorescent complex OMH@α-CD in Example 11;

[0048] Fig.14 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex p-HH@α-CD in Example 12;

[0049] Fig.15 This is a luminescent photograph of the benzoic acid host-guest phosphorescent complex o-HH@α-CD in Example 13;

[0050] Fig.16 This is the luminescence photograph of the benzoic acid host-guest phosphorescent complex NAH@α-CD in Example 14. DETAILED DESCRIPTION

[0051] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0052] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0053] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0054] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0055] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0056] The raw materials (the listed benzoic acid derivatives) used in the present invention are all commercially available, cyclodextrin (α / β / γ-CD) is commercially available, and the relevant preparation method is synthesized according to the literature (J. Org. Chem. 2001, 66, 8094-8100). This is hereby explained.

[0057] The present invention provides a benzoic acid host-guest phosphorescent complex, which uses cyclodextrin (α / β / γ-CD) as a macrocyclic host molecule (H), benzoic acid and its derivatives (G) as phosphorescent guest molecules, and utilizes host-guest interaction and hydrogen bond interaction to effectively combine with organic phosphorescent guest molecules to obtain a fully organic room temperature phosphorescent material that has both phosphorescence and a long afterglow time and can stably exist in the air for a long time, and has a formula (I):

[0058]

[0059] For example, taking aminobenzoic acid and its derivatives as an example, the preparation route of the benzoic acid host-guest phosphorescent complex is as follows:

[0060]

[0061] The present invention provides two types (solid, crystalline) of benzoic acid host-guest phosphorescent complexes, comprising:

[0062] 1. Preparation method of phosphorescent composite solid material:

[0063] (1) One implementation method is: using benzoic acid and its derivatives as the guest (G), and macrocyclic host cyclodextrin (α / β / γ-CD) as the host (H), adding water and grinding according to different ratios of host and guest H:G = 1 to 1000:1 to obtain a phosphorescent composite solid material.

[0064] When grinding with water, the amount of water added is not enough to completely dissolve the host and guest, so that the host and guest are in a paste state. The grinding time is 15 minutes, and the grinding is repeated three times.

[0065] (2) Another implementation method is: H is dissolved in water, and a saturated solution of an organic reagent of G (methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide) is gradually added dropwise to the aqueous solution of H according to different ratios of host and guest H:G=1 to 1000:1 under continuous stirring, and ultrasonically mixed to be uniform, and all the mixed solution is poured into a watch glass, and then placed in an oven, and dried to obtain a phosphorescent composite solid material.

[0066] Wherein, the concentration of the aqueous solution of H is 0.01-0.5 mol / L.

[0067] 2. Preparation method of phosphorescent composite crystals:

[0068] (1) One implementation method is: according to H:G=1-1000:1, a saturated solution of an organic reagent of G (methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide) is gradually added dropwise to an aqueous solution of H under continuous stirring. The reaction mixture is reacted at 50°C for 5 hours and then slowly cooled to room temperature. 1-5% of the total volume of water is added to the filtrate, and the mixture is allowed to stand at room temperature for about two weeks, and colorless crystals are generated; the generated precipitate is filtered, and the crude product is dissolved in hot water at 40-90°C to prepare a saturated solution. After cooling to room temperature, the precipitated solid is filtered off, and then a small amount of water is added to the filtrate, and the mixture is allowed to stand at room temperature for about two weeks, and colorless crystals are generated.

[0069] (2) Another implementation method is: according to H:G=1-1000:1, add water to grind, continue to slowly add water, ultrasonicate to reach saturation concentration, add a small amount of water, filter the solution with a syringe filter, and transfer it to different vials. Let it stand at room temperature for about two weeks, and colorless crystals will form; let the organic solvent (methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide) slowly diffuse into the solution within one week, and colorless crystals will form.

[0070] (3) Another implementation method is: according to H:G=1-1000:1, add water and grind, finally dissolve in 3 ml of water or in a mixed solvent of 2 ml of water and 1 ml of an organic reagent (acetonitrile, isopropanol, N,N-dimethylformamide, dimethyl sulfoxide), further heat in a hydrothermal reactor at 80-110°C for 2-4 hours, slowly cool to room temperature, add a small amount of water to the filtrate, let it stand at room temperature for about two weeks, and colorless crystals will be generated; filter the generated precipitate, dissolve the crude product in hot water to prepare a saturated solution, cool to room temperature and filter out the precipitated solid, then add a small amount of water to the filtrate, let it stand at room temperature for about two weeks, and colorless crystals will be generated.

[0071] Example 1

[0072] Example 1 of the present invention discloses NH@CD composite materials prepared from NH (aminobenzoic acid) and α / β / γ-CD, including: NH@α-CD, NH@β-CD, NH@γ-CD. The preparation route of the NH@CD composite material is as follows:

[0073]

[0074] In Example 1 of the present invention, a benzoic acid host-guest phosphorescent complex NH@α-CD is prepared, and the specific preparation method is as follows:

[0075] NH was used as the guest (G) and α-CD was used as the host (H) at a ratio of H:G = 2:1 and ground into a paste. The grinding time was 15 minutes and the grinding was repeated three times to obtain a white phosphorescent composite solid material.

[0076] The present invention further discloses the application of NH@α-CD as described above in food and drug encryption. Para-aminobenzoic acid (NH), also known as vitamin B10 (VB10), is an important component of folic acid necessary for cell growth and division in the body. It is present in large quantities in yeast, liver, wheat bran and malt. In addition, cyclodextrin is a cyclic oligosaccharide composed of glucose molecules, which is processed from potato, corn, wheat and other starches and is a recognized edible macrocyclic molecule. A saturated solution of NH@α-CD is applied to food and tablets. After drying, it appears normal under visible light, but under the excitation of 254-nanometer ultraviolet light, the patterns of "QL" and "VB10@CD" show a blue afterglow, such as Figure 1 shown.

[0077] Among them, NH is used as the guest (G) and α-CD is used as the host (H). The prepared NH@α-CD powder shows blue emission under 254UV. After the excitation is removed, blue light is emitted and the phosphorescence lifetime is 209.63ms. The quantum yield can reach 53.6%. The results are shown in Figure 2 ;

[0078] Example 2

[0079] Example 2 of the present invention adopts the preparation method of Example 1, and increases the molar ratio of the macrocyclic host α-CD to NH in the host-guest phosphorescent complex to 1000:1, and shows the ratio changes of 1:1, 10:1, 100:1, and 1000:1, and detects whether it has fluorescence. The results are shown in FIG. Figure 3 .

[0080] Figure 3 It was shown that increasing the molar ratio of the macrocyclic host α-CD to NH in the host-guest phosphorescent complex to 1000:1 still produced bright blue phosphorescence.

[0081] Example 3

[0082] Example 3 of the present invention adopts the method of Example 1, using NH as the guest (G) and β-CD as the host (H) to prepare NH@β-CD powder.

[0083] The obtained NH@β-CD powder showed blue emission under 254UV (see Figure 4 ), after the excitation is removed, it emits blue light with a phosphorescence lifetime of 555.15 ms, and the quantum yield can reach 49.4%.

[0084] Similarly, by changing the molar ratio of β-CD to NH to 1000:1, the ratios of 1:1, 10:1, 100:1, and 1000:1 were shown. When the molar ratio of the macrocyclic host β-CD to NH in the host-guest phosphorescent complex was increased to 1000:1, there was still bright blue phosphorescence (see Figure 5 ).

[0085] Similarly, NH@γ-CD can be prepared with NH as the guest (G) and γ-CD as the host (H). The NH@γ-CD powder shows blue emission under 254UV (see Figure 6 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 561ns, and the quantum yield can reach 7.4%.

[0086] Example 4

[0087] Example 4 of the present invention prepares NH@α-CD crystals, comprising the following steps:

[0088] According to the molar ratio of H:G = 1:1, the saturated solution of G in dimethyl sulfoxide was gradually added dropwise to the aqueous solution of H with a concentration of 0.5 mol / L under continuous stirring. The reaction mixture was reacted at 50°C for 5 hours and then slowly cooled to room temperature. 3% of the total volume of water was added to the filtrate, and it was allowed to stand at room temperature for about two weeks, and colorless crystals were generated; the precipitate was filtered, and the crude product was dissolved in 90°C hot water to prepare a saturated solution. After cooling to room temperature, the precipitated solid was filtered out, and then a small amount of water was added to the filtrate, and it was allowed to stand at room temperature for about two weeks, and colorless crystals NH@α-CD were generated.

[0089] NH@α-CD crystals emit strong blue fluorescence and show a bright blue afterglow for up to 6 seconds after the 254nm ultraviolet irradiation stops. The lifetime of the time-resolved emission spectrum monitored at a wavelength of 434nm is 977ms, and the photoluminescence quantum yield reaches 84.4%; NH@β-CD crystals emit strong blue fluorescence and show a bright blue afterglow for up to 7 seconds after the 254nm ultraviolet irradiation stops. The lifetime of the time-resolved emission spectrum monitored at a wavelength of 434nm is 1.16s, and the photoluminescence quantum yield reaches 86.5%.

[0090] Example 5

[0091] In Example 5 of the present invention, a benzoic acid host-guest phosphorescent complex NMH@α-CD was prepared. The specific preparation method is as follows:

[0092] NMH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Figure 7 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 701ms, and the quantum yield can reach 35.4%.

[0093] The preparation route of NMH@α-CD composite material is as follows:

[0094]

[0095] Example 6

[0096] In Example 6 of the present invention, a benzoic acid host-guest phosphorescent complex NMMH@α-CD was prepared. The specific preparation method is as follows:

[0097] NMMH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Figure 8 ), after removing the excitation, it emits blue light with an ultra-long phosphorescence lifetime of 534ms, and the quantum yield can reach 39.6%.

[0098] The preparation route of NMMH@α-CD composite material is as follows:

[0099]

[0100] Example 7

[0101] In Example 7 of the present invention, a benzoic acid host-guest phosphorescent complex ACNH@α-CD was prepared. The specific preparation method is as follows:

[0102] ACNH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Fig. 9 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 245.66ms and a quantum yield of 5.9%.

[0103] The preparation route of ACNH@α-CD composite material is as follows:

[0104]

[0105] Example 8

[0106] In Example 8 of the present invention, a benzoic acid host-guest phosphorescent complex NM@α-CD is prepared, and the specific preparation method is as follows:

[0107] NM was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Fig.10 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 96.33 ms and a quantum yield of 34.6%.

[0108] The preparation route of NM@α-CD composite material is as follows:

[0109]

[0110] Example 9

[0111] In Example 9 of the present invention, a benzoic acid host-guest phosphorescent complex PYH@α-CD is prepared, and the specific preparation method is as follows:

[0112] PYH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A blue phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Fig.11 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 503.20ms, and the quantum yield can reach 25.7%.

[0113] The preparation route of PYH@α-CD composite material is as follows:

[0114]

[0115] Example 10

[0116] In Example 10 of the present invention, a benzoic acid host-guest phosphorescent complex OHH@α-CD is prepared, and the specific preparation method is as follows:

[0117] OHH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Fig.12 ), after the excitation is removed, it emits blue light with an ultra-long phosphorescence lifetime of 324ms, and the quantum yield can reach 20.8%.

[0118] The preparation route of OHH@α-CD composite material is as follows:

[0119]

[0120] Embodiment 11

[0121] In Example 11 of the present invention, a benzoic acid host-guest phosphorescent complex OMH@α-CD was prepared. The specific preparation method is as follows:

[0122] OMH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1. Water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed blue emission under 254UV (see Fig.13 ), after removing the excitation, it emits blue light and has an ultra-long phosphorescence lifetime of 119.10ms, and the quantum yield can reach 12.8%. The preparation route of OMH@α-CD composite material is as follows:

[0123]

[0124] Example 12

[0125] In Example 12 of the present invention, a benzoic acid host-guest phosphorescent complex p-HH@α-CD was prepared. The specific preparation method is as follows:

[0126] With p-HH as the guest (G) and α-CD as the host (H), the mixture was mixed in a molar ratio of H:G = 2:1, and water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid to obtain a white phosphorescent composite solid material. It showed blue emission under 254UV (see Fig.14 ), after the excitation is removed, it emits blue light with a phosphorescence lifetime of 110.08ms, and the quantum yield can reach 9.2%.

[0127] The preparation route of p-HH@α-CD composite material is as follows:

[0128]

[0129] Embodiment 13

[0130] In Example 13 of the present invention, a benzoic acid host-guest phosphorescent complex o-HH@α-CD was prepared. The specific preparation method is as follows:

[0131] o-HH was used as the guest (G) and α-CD was used as the host (H). The mixture was mixed in a molar ratio of H:G = 2:1, and water was added to make it a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid. A white phosphorescent composite solid material was obtained. It showed cyan emission under 254UV (see Fig.15 ), after removing the excitation, it emits blue light with a phosphorescence lifetime of 30.39 ms and a quantum yield of 6.6%.

[0132] The preparation route of o-HH@α-CD composite material is as follows:

[0133]

[0134] Embodiment 14

[0135] In Example 14 of the present invention, a benzoic acid host-guest phosphorescent complex NAH@α-CD was prepared, and the specific preparation method is as follows:

[0136] NAH was used as the guest (G) and α-CD as the host (H), and the mixture was mixed in a molar ratio of H:G = 2:1, and water was added to make it into a paste. The grinding time was 15 minutes, and the grinding was repeated three times until it became turbid to obtain a white phosphorescent composite solid material. It showed cyan emission under 254UV (see Fig.16 ), after the excitation is removed, blue light is emitted with a phosphorescence lifetime of 276.61 ms and a quantum yield of 60.5%.

[0137] The preparation route of NAH@α-CD composite material is as follows:

[0138]

[0139] Here, the above examples are summarized, and the results of the phosphorescent complex formed by α / β / γ-CD and benzoic acid derivatives and the crystal photophysical properties thereof are summarized in Table 1:

[0140] Table 1 Crystal photophysical properties of different benzoic acid host-guest phosphorescent complexes

[0141] Complexes <![CDATA[E X (nm)]]> <![CDATA[λ p (nm)]]> <![CDATA[τ p (ms)]]> <![CDATA[φ FL (%)]]> <![CDATA[NH@α-CD b ]]> 300 434 977 84.4 <![CDATA[NH@β-CD b ]]> 300 433 1157 86.5 <![CDATA[NH@γ-CD a ]]> 300 438 0.46 7.4 <![CDATA[NMH@α-CD a ]]> 300 437 701 35.4 <![CDATA[NMMH@α-CD a ]]> 300 442 534 39.6 <![CDATA[ACNH@α-CD a ]]> 300 503 245.66 5.9 <![CDATA[NM@α-CD a ]]> 300 420 96.30 34.6 <![CDATA[PYH@α-CD a ]]> 300 441 503.20 25.7 <![CDATA[OHH@α-CD a ]]> 300 408 324 20.8 <![CDATA[OMH@α-CD a ]]> 300 415 119.10 12.8 <![CDATA[p-HH@α-CD a ]]> 300 417 110.08 9.2 <![CDATA[o-HH@α-CD a ]]> 300 530 30.39 6.6 <![CDATA[NAH@α-CD a ]]> 300 470 276.61 60.5

[0142] Note: The table headers are Complexes, E X (nm) refers to the wavelength of the excitation light, λ p (nm) refers to the peak wavelength of phosphorescence, τ p (ms) refers to the phosphorescence lifetime and φ FL (%) refers to the photoluminescence quantum yield (the a in the upper right corner of the composite represents powder and the b represents crystal)

[0143] Conclusion: The complexes of all α / β / γ-CD and benzoic acid derivatives and their crystal-related photophysical data are shown in Table 1. The results show that this strategy can be used to further restrict benzoic acid derivatives so that the phosphorescence lifetime or quantum yield can be greatly improved, thus obtaining a type of phosphorescent anti-counterfeiting encryption material.

[0144] The present invention develops an edible RTP material with low cost, long life and high brightness. By utilizing the advantages of benzoic acid and its derivatives being commercially available, low cost and easy to obtain, and by simply grinding with a macrocyclic host cyclodextrin (α / β / γ-CD), and utilizing host-guest interaction and hydrogen bond interaction, an organic room temperature phosphorescent material having both phosphorescence phenomenon and long afterglow time, which can stably exist in the air for a long time, is non-toxic and environmentally friendly, is obtained, and a phosphorescent complex can be formed.

[0145] The present invention addresses the difficulty in preparing low-cost, long-life and high-brightness RTP materials, as well as the problem that current RTP materials are toxic. By utilizing the advantages of benzoic acid and its derivatives being commercially available, low-cost and easily available, the present invention forms a non-toxic phosphorescent complex with a macrocyclic host cyclodextrin (α / β / γ-CD) through simple grinding, thereby achieving bright blue phosphorescent emission and being applied to anti-counterfeiting encryption of food and medicine.

[0146] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited to the specific details in the above embodiments. Those skilled in the art will appreciate that, without departing from the spirit and scope of the present invention, a variety of equivalent replacements, modifications or improvements may be made to the technical solution of the present invention and its embodiments, which all fall within the scope of the present invention. It should also be noted that, in the absence of contradictions, the various specific technical features described in the above specific embodiments may be combined in any suitable manner to avoid unnecessary duplication. In addition, any combination of the various embodiments of the present invention may also be performed, and as long as they do not violate the concept of the present invention, they shall also be regarded as the contents disclosed by the present invention.

Claims

1. A benzoic acid host-guest phosphorescent complex, characterized in that: The benzoic acid host-guest phosphorescent complex is prepared by a host-guest complexation reaction between a macrocyclic host cyclodextrin and benzoic acid and its derivatives. The structure of the benzoic acid host-guest phosphorescent complex is shown in formula (I):

2. The benzoic acid host-guest phosphorescent complex according to claim 1, characterized in that: The molar ratio of the macrocyclic host cyclodextrin to benzoic acid and its derivatives in the benzoic acid host-guest phosphorescent complex is 1-1000:

1.

3. The benzoic acid host-guest phosphorescent complex according to claim 1, characterized in that: The benzoic acid and its derivatives include one of the following compounds: benzoic acid, p-aminobenzoic acid, 4-methylaminobenzoic acid, 4-dimethylaminobenzoic acid, 4-(N,N-diethylamino)-benzoic acid, 4-aminobenzoic acid methyl ester, p-aminobenzenesulfonic acid, aminobenzoic acid hydrochloride, 4-dimethylaminobenzoic acid hydrochloride, 4-(1-pyrrolidinyl)benzoic acid, p-hydroxybenzoic acid, terephthalic acid, p-chlorobenzoic acid, p-bromobenzoic acid, p-iodobenzoic acid , p-methoxybenzoic acid, p-methylthiobenzoic acid, p-acetamidobenzoic acid, 2-naphthoic acid, 2-anthracenecarboxylic acid, m-aminobenzoic acid, 3,4-diaminobenzoic acid, 4-amino-3-hydroxybenzoic acid, 3-chloro-4-benzoic acid, 1-pyrenecarboxylic acid, 4-amino-3-bromobenzoic acid, phthalic acid, isophthalic acid, 3,5-diaminobenzoic acid, s-tribenzoic acid, 4-hydroxypyridine, 4-phenylpyridine, 4-(pyridin-4-yl)aniline; The macrocyclic main body cyclodextrin includes one of cyclodextrin α-CD, β-CD and γ-CD.

4. A method for preparing the benzoic acid host-guest phosphorescent complex as claimed in claim 1, characterized in that: The prepared product is a phosphorescent composite solid material, and the preparation method comprises the following steps: Benzoic acid and its derivatives are used as guests, and macrocyclic host cyclodextrin α / β / γ-CD is used as the main body. The mixture is mixed according to a set ratio, and water is added and ground to obtain a benzoic acid host-guest phosphorescent composite solid material.

5. A method for preparing the benzoic acid host-guest phosphorescent complex as claimed in claim 1, characterized in that: The prepared product is a phosphorescent composite solid material, and the preparation method comprises the following steps: Taking benzoic acid and its derivatives as guests and macrocyclic main body cyclodextrin α / β / γ-CD as main body, the macrocyclic main body cyclodextrin is dissolved in water according to a set ratio to obtain a cyclodextrin aqueous solution, the benzoic acid and its derivatives are dissolved in an organic solvent to obtain a saturated solution of benzoic acid and its derivatives, the saturated solution of benzoic acid and its derivatives is added dropwise into the cyclodextrin aqueous solution while stirring, ultrasonically mixed, and dried to obtain a benzoic acid host-guest phosphorescent complex solid material.

6. A method for preparing the benzoic acid host-guest phosphorescent complex as claimed in claim 1, characterized in that: The prepared product is a phosphorescent composite crystal material, and the preparation method comprises the following steps: Taking benzoic acid and its derivatives as the guest, and macrocyclic main body cyclodextrin α / β / γ-CD as the main body, according to the set ratio, the macrocyclic main body cyclodextrin is dissolved in water to obtain a cyclodextrin aqueous solution, and the benzoic acid and its derivatives are dissolved in an organic solvent to obtain a saturated solution of benzoic acid and its derivatives; A saturated solution of benzoic acid and its derivatives is added dropwise to a cyclodextrin aqueous solution while stirring, and the mixture is reacted at 45-60°C for 4-6 hours. The mixture is then cooled to room temperature, and an appropriate amount of water is added to the filtrate. The mixture is allowed to stand at room temperature until colorless crystals are generated. The generated precipitate is filtered, and the crude product is dissolved in hot water to prepare a saturated solution. The solution is cooled to room temperature and the precipitated solid is filtered off. An appropriate amount of water is then added to the filtrate. The mixture is allowed to stand at room temperature until colorless crystals are generated, thereby obtaining a benzoic acid host-guest phosphorescent complex crystal material.

7. A method for preparing the benzoic acid host-guest phosphorescent complex as claimed in claim 1, characterized in that: The prepared product is a phosphorescent composite crystal material, and the preparation method comprises the following steps: Benzoic acid and its derivatives are used as guests, and the macrocyclic host cyclodextrin α / β / γ-CD is used as the main body. They are mixed according to a set ratio, ground with water, slowly added with water, and ultrasonicated to reach saturated concentration. Then an appropriate amount of water is added, and the mixture is filtered and transferred to different vials. The mixture is allowed to stand at room temperature to generate colorless crystals. The organic solvent is allowed to slowly diffuse into the solution within a week, and colorless crystals are generated, thereby obtaining a benzoic acid host-guest phosphorescent complex crystal material.

8. A method for preparing the benzoic acid host-guest phosphorescent complex as claimed in claim 1, characterized in that: The prepared product is a phosphorescent composite crystal material, and the preparation method comprises the following steps: Benzoic acid and its derivatives are used as guests, and macrocyclic host cyclodextrin α / β / γ-CD is used as the main body, mixed according to a set ratio, ground with water, dissolved in a solvent, heated at 80-110° C. for 2-4 hours, then slowly cooled to room temperature, added a proper amount of water to the filtrate, allowed to stand at room temperature, colorless crystals are generated, the generated precipitate is filtered, the crude product is dissolved in hot water to prepare a saturated solution, cooled to room temperature, filtered to remove the precipitated solid, then added a proper amount of water to the filtrate, allowed to stand at room temperature, colorless crystals are generated, and a benzoic acid host-guest phosphorescent complex crystal material is obtained; The solvent is water or a mixture of water and an organic reagent, the volume ratio of water to the organic reagent in the mixture of water and organic reagent is 2:1, and the organic reagent is one of acetonitrile, isopropanol, N,N-dimethylformamide, and dimethyl sulfoxide.

9. The method for preparing the benzoic acid host-guest phosphorescent complex according to claim 5, 6 or 7, characterized in that: The organic solvent is one of methanol, ethanol, acetonitrile, acetone, isopropanol, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide.

10. Use of a benzoic acid host-guest phosphorescent complex prepared by the preparation method of the benzoic acid host-guest phosphorescent complex according to any one of claims 1 to 3 or the benzoic acid host-guest phosphorescent complex according to any one of claims 4 to 8 in food and drug encryption and anti-counterfeiting.

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