CN111320899B

CN111320899B - Kit and application thereof in preparation of visual organic solvent indicator and writing of confidential documents

Info

Publication number: CN111320899B
Application number: CN202010177802.5A
Authority: CN
Inventors: 杨成
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2020-03-13
Filing date: 2020-03-13
Publication date: 2021-09-03
Anticipated expiration: 2040-03-13
Also published as: CN111320899A

Abstract

The invention relates to a kit and application thereof in preparing a visual organic solvent indicator and writing a security document. Specifically provides a kit, which comprises the following components: the component A comprises: pillar arene P [ n ]](ii) a And B component: total oxidation product of pillar arene P [ n ]]And Q. The kit may further comprise a component C: an organic solvent. Experiments of the invention find that P [ n ]]And P [ n ]]And the composition obtained by Q mixing is exposed to different organic solvent vapors, and the system has different color changes, so that the rapid visual identification of common organic solvents can be simply and conveniently realized through whether CT complexes are formed in the vapors of different organic solvents, and the formation time and color change of the CT complexes. In addition, the compositions and CT complexes of the invention are highly stable and can be recycled multiple times. Therefore, the kit has good application prospects in preparation of visual organic solvent indicators, electrochemical sensing and writing of confidential documents.

Description

Kit and application thereof in preparation of visual organic solvent indicator and writing of confidential documents

Technical Field

The invention belongs to the field of composite materials, and particularly relates to a kit and application thereof in preparation of a visual organic solvent indicator and writing of a confidential document.

Background

Pillar arenes are a new class of supramolecular macrocyclic compounds with unique cavity and columnar molecular structures whose unique host-guest chemistry and cavity size enable them to selectively recognize and capture specific small molecules. Thus, the emergence of pillared aromatics has accelerated the development of supramolecular chemistry and provided new opportunities for material chemistry. Since the first report in 2008, pillar arenes have become key players in supramolecular chemistry.

Known literature "based on the preparation of column [5] arene polymer hydrogel and the visual detection of paraquat, the high molecular bulletin 2017, month 1, phase 1" discloses a polymer hydrogel containing column [5] arene, which is formed by reacting a self-made mono-functionalized column [5] arene monoene with acrylamide (AAM), a crosslinking agent N, N' -Methylene Bisacrylamide (MBA) and an initiator Azobisisobutyronitrile (AIBN) at 70 ℃ for 12 hours to form a high molecular polymer containing macrocyclic main column [5] arene. The polymer hydrogel containing the column [5] arene has an absorption effect on paraquat, and the color of the hydrogel is changed from light yellow to brownish red by immersing the hydrogel into paraquat solution with the concentration from small to large, which is caused by the host-guest action between the column [5] arene and N, N '-dimethyl-4, 4' -bipyridyl guest molecules in the hydrogel to form a supermolecule polymer containing a pseudorotaxane structure. The hydrogel realizes the visual detection of paraquat.

However, the host-guest interactions between different structures of the pillared aromatic hydrocarbon and different substances are different, and the polymer hydrogel containing the pillared [5] aromatic hydrocarbon reported in the known literature cannot be used for the visual detection of other substances, such as common organic solvents. At present, there are also few reports about visual detection of organic solvents, so that the method further researches the host-guest interaction between the cyclophane and the derivative thereof to prepare the indicating reagent capable of rapidly, simply and conveniently identifying common organic solvents has very important significance.

Besides being used for visual detection, the application of supramolecular macrocyclic compounds such as pillar arene and the like in other fields is receiving more and more attention. For example, in the aspect of security writing, a known document "supramolecular functional material based on functionalized naphthalimide and pillared [5] arene" discloses a naphthalimide derivative G1 with a pyridine group functionalized, G1 can be self-assembled into stable ionic supramolecular gel is-G in organic acid, and the supramolecular gel is of great use value in the field of fluorescent security materials. However, the pyridine group functionalized naphthalimide derivative G1 is complex in preparation process and high in cost. If host-guest interactions between supramolecular macrocycles can be further studied, supramolecules that develop color under specific conditions can be prepared by simple methods, which will have very good potential in the preparation of security materials or in the writing of security documents.

Disclosure of Invention

The invention aims to provide a kit consisting of a supramolecular macrocyclic compound columnar arene Pn and a columnar quinone Pn Q obtained by full oxidation of the columnar arene, and application thereof in preparing a visual organic solvent indicator and writing a confidential document.

The invention provides a kit, which comprises the following components:

the component A comprises: a pillar arene P [ n ];

and B component: the product PnQ of the total oxidation of the column aromatics;

wherein, the structures of P [ n ] and P [ n ] Q are as follows:

a is an integer of 1 to 6, R is C_1～6An alkyl group.

Further, P [ n ] is DMP5, and P [ n ] Q is P5Q:

furthermore, the molecular number ratio of Pn to Pn Q is (1-2): 1, preferably 1: 1.

Further, the kit also comprises a component C: an organic solvent;

the organic solvent is preferably one or more than two of the following organic solvents: dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform, tetrahydrofuran, diethyl ether and other common alkanes, alkenes, halogenated hydrocarbons, organic alcohols, organic acids, aromatic hydrocarbons.

The invention also provides a method for rapidly and visually identifying common organic solvents, which is carried out by using the kit and comprises the following steps:

mixing the component A and the component B in the kit, exposing the mixture to common organic solvent steam to be identified, and observing color change;

preferably, the common organic solvent to be identified is selected from dichloromethane, acetonitrile, acetone, ethyl acetate, diethyl ether chloroform, tetrahydrofuran and other common alkanes, alkenes, halogenated hydrocarbons, organic alcohols, organic acids, aromatic hydrocarbons.

The invention also provides an encryption and decryption method of the confidential document, which is carried out by using the kit and comprises the following steps:

(a) encryption: dissolving the component A by using the component C to obtain a solution A; dissolving the component B by using the component C to obtain a solution B; writing a security document with the solution A; the concentration of the solution A and the solution B is preferably 1.5 mmol.L^-1More preferably 1.5 to 2.0 mmol/L^-1；

(b) And (3) decryption: spraying the security document written in the step (a) with the solution B to display the content of the security document.

The invention also provides application of the kit in preparation of a visual organic solvent indicator.

The invention also provides the application of the kit in writing security documents.

The invention also provides a composition consisting of Pn and Pn Q as defined above.

The invention also provides a charge transfer complex formed by the composition and organic solvent molecules.

Further, in the charge transfer complex, the molecular number ratio of Pn, Pn Q and the organic solvent is 1:1: (1 to 3), preferably 1:1: 2.

further, the organic solvent is one or more than two of the following organic solvents: dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform, tetrahydrofuran, diethyl ether and other common alkanes, alkenes, halogenated hydrocarbons, organic alcohols, organic acids, aromatic hydrocarbons.

Further, the organic solvent is dichloromethane, and in a PXRD spectrogram of the charge transfer compound, a 2 theta diffraction angle has characteristic absorption peaks at 9.83 +/-0.2 degrees, 10.11 +/-0.2 degrees, 10.98 +/-0.2 degrees, 13.15 +/-0.2 degrees, 15.71 +/-0.2 degrees, 16.23 +/-0.2 degrees, 23.91 +/-0.2 degrees, 24.43 +/-0.2 degrees, 25.63 +/-0.2 degrees and 26.22 +/-0.2 degrees;

preferably, the intensities of the characteristic absorption peaks at the 2 θ diffraction angles are as follows:

angle of 2 theta diffraction	Strength of
		9.83±0.2°	2395.08
10.11±0.2°	2037.21
		10.98±0.2°	1815.55
13.15±0.2°	1949.68
		15.71±0.2°	2998.64
16.23±0.2°	1903.68
		23.91±0.2°	8227.71
24.43±0.2°	5388.84
		25.63±0.2°	3044.04
26.22±0.2°	2664.81

More preferably, the PXRD pattern of the charge transfer complex is as shown in fig. 4 (a).

Further, the color of the charge transfer complex is purple.

The present invention also provides a method of preparing the above charge transfer complex, the method comprising the steps of:

dissolving Pn and PnQ in organic solvent to obtain Pn solution and PnQ solution, and mixing to obtain mixed solution; standing to separate out solid, namely the charge transfer compound.

Further, the P [ n ]]In solution, P [ n ]]Has a concentration of 1.5 mmol. L^-1Above, preferably 1.5 to 2.0 mmol.L^-1(ii) a The P [ n ]]In solution Q, P [ n ]]The concentration of Q was 1.5 mmol. multidot.L^-1Above, preferably 1.5 to 2.0 mmol.L^-1；

And/or the temperature of the standing is below normal temperature, preferably below 4 ℃.

In the present invention, a CT complex, i.e., a charge transfer complex, is a complex in which electrons are transferred between an electron donor and an electron acceptor when an electron-deficient electron acceptor and an electron-rich electron donor are combined, and is substantially a complex formed by a dipole-dipole interaction between molecules.

In the organic solvent of the invention, dichloromethane is DCM, acetonitrile is acetonitrile, acetone is acetone, ethyl acetate is EA, chloroform is CHCl₃Tetrahydrofuran (THF), tetrachloroethane (tetrachloroethane), anhydrous ether (anhydro ether), methanol (methanol), ethanol (EtOH), n-hexane (n-hexane), n-pentane (n-pentane), Petroleum Ether (PE), cyclohexane (cyclohexoxane), and carbon tetrachloride (carbon tetrachloride).

Normal temperature means 25 + -2 deg.C.

C_1～6The alkyl group is a straight chain or branched chain alkyl group having 1 to 6 carbon atoms.

The present invention uses column arene Pn of supermolecule macrocyclic compound and column quinone Pn Q obtained by column arene full oxidation as raw material, and under the mediation of specific organic solvent molecule a new supermolecule binary CT compound is made up. When DMP5 and P5Q are used as raw materials and DCM is selected as an organic solvent, the molecular number ratio of DMP5, P5Q and organic solvent molecules in the obtained CT compound is 1:1: 2. experiments prove that the composition obtained by mixing equimolar DMP5 and P5Q is exposed to different organic solvent vapors, so that the system has different color changes, and quick visual identification of common organic solvents can be simply realized by whether CT complexes are formed in the vapors of different organic solvents or not, and the formation time and color change of the CT complexes. In addition, the compositions and CT complexes of the invention are highly stable, can be recycled many times, and maintain good activity after 5 cycles. Therefore, the kit has good application prospects in preparation of visual organic solvent indicators, electrochemical sensing and writing of confidential documents.

Obviously, many modifications, substitutions, and variations are possible in light of the above teachings of the invention, without departing from the basic technical spirit of the invention, as defined by the following claims.

The present invention will be described in further detail with reference to the following examples. This should not be understood as limiting the scope of the above-described subject matter of the present invention to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.

Drawings

FIG. 1 is a schematic diagram of the formation of CT complexes.

FIG. 2 is a solid state UV-Vis spectral test pattern.

FIG. 3(a) is a FT-IR test spectrum wherein "DMP 5-P5Q complex" indicates CT complex DMP5-P5Q @2DCM and "1: 1DMP5-P5Q mix" indicates a mixed powder obtained by machine milling equimolar DMP5 and P5Q solids, obtained from example 4; FIG. 3(b) is a TGA result of CT complex DMP5-P5Q @2DCM from example 4; FIG. 3(c) is a photograph obtained in example 4Method for preparing CT complex DMP5-P5Q @2DCM¹H NMR spectrum.

FIG. 4 is a PXRD spectrum wherein (a) represents the CT complex DMP5-P5Q @2DCM obtained in example 4, (b) represents the mixed powder obtained by machine milling equimolar DMP5 and P5Q solids, (c) represents the P5Q obtained in example 1, and (d) represents the DMP5 obtained in example 1.

FIG. 5 shows the color development of P5Q and DMP5 mixtures in different organic solvents, wherein the organic solvents represented by the respective numbers are: 1. dichloromethane, 2 acetonitrile, 3 acetone, 4 ethyl acetate, 5 chloroform, 6 tetrahydrofuran, 7 tetrachloroethane, 8 anhydrous ether, 9 methanol, 10 n-hexane, 11 cyclohexane and 12 carbon tetrachloride.

FIG. 6 is a bar graph showing the color development of mixtures of P5Q and DMP5 in Table 1 in different organic solvent vapors, wherein the incubation time represents t in Table 1₁The coloration time represents Δ t in table 1.

FIG. 7 is a diagram of: (a) visualizing the cycling performance of the organic solvent indicator, (b) PXRD (red) of the resulting solvent-stripped mixture of DMP5 and P5Q after 5 cycles and PXRD (black) of the resulting mixture milled with the initial DMP5 and P5Q in a 1:1 molar ratio.

Fig. 8 is photographs of characters (a) before and (b) after writing characters in experimental example 6.

FIG. 9 is a schematic operation diagram of the rapid visual identification of common organic solvents by CT complexes according to the present invention.

Detailed Description

The raw materials and equipment used in the invention are known products and are obtained by purchasing commercial products.

Example 1 preparation of the kit 1 of the invention

1. Synthesis of 1, 4-dimethoxycolumn [5] arene (DMP 5):

a500 mL round-bottom flask was charged with p-methoxybenzene (6.00g, 43.43mmol), paraformaldehyde (8.68g, 130.29mmol) in that order, and 1, 2-dichloroethane (200.0mL) was added as a solvent, oftenDissolving the mixture by warm stirring, and then adding a catalyst BF₃·OEt₂(4.33 mL). The reaction mixture was stirred at room temperature for 40 minutes and monitored by TLC (pure DCM) to confirm completion of the reaction. The system after the reaction was completed was poured into 300.0mL NaHCO₃The catalyst was quenched in aqueous solution, the mixture was stirred with a glass rod until the reaction solution turned from dark green to gray, DCM was added, the layers were separated, and the organic solvent was removed in vacuo to give the crude product. The crude product was then purified by column chromatography (silica, pure DCM) to give DMP5(2.69g) as a white solid in 41.26% yield.

2. Synthesis of column [5] quinone (P5Q):

in a 250mL round bottom flask 1.00g1, 4-diethoxy column [5] was dissolved with 60mL THF]Aromatic hydrocarbons, then 10mL of H₂Dissolving 7.5g (11eq) of ammonium ceric nitrate as oxidant in O, adding into the reaction flask at one time, allowing the solution to rapidly change from dark red to light orange and precipitating pale yellow solid, reacting completely after about 2min, vacuum filtering to obtain pale yellow solid, and respectively dissolving with H₂Washing with O and ethanol for 2-3 times to obtain light yellow solid P5Q.

3. The DMP5 is used as an A component, and the P5Q is used as a B component, and the DMP5 is controlled to be: the molar ratio of P5Q is 1:1, the kit 1 of the present invention was prepared.

Example 2 preparation of the kit 2 of the invention

With the DMP5 of example 1 as the A component, P5Q as the B component, and methylene chloride as the C component, the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-1 of the invention.

With the DMP5 of example 1 as the A component, P5Q as the B component, and acetonitrile as the C component, the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-2 of the invention.

Taking DMP5 in example 1 as A component, P5Q as B component and acetone as C component, controlling the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-3 of the invention.

Taking DMP5 in example 1 as A component, P5Q as B component and ethyl acetate as C component, controlling the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-4 of the invention.

With DMP5 as the A component, P5Q as the B component, and chloroform as the C component in example 1, the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-5 of the invention.

With the DMP5 of example 1 as the A component, P5Q as the B component, and tetrahydrofuran as the C component, the ratio of DMP 5: the molar ratio of P5Q is 1:1, preparing the kit 2-6 of the invention.

Example 3 preparation of the composition of the invention

The composition of the present invention was obtained by mixing the P5Q and DMP5 (molar ratio 1: 1) of example 1 uniformly.

Example 4 preparation of inventive CT complexes

P5Q and DMP5 (molar ratio 1: 1) from example 1 were taken and dissolved in Dichloromethane (DCM) to give two clear DCM solutions (concentration 2.0 mmol. multidot.L each)^-1) Then, the two solutions were mixed to obtain a pale yellow mixed solution, which was placed in a refrigerator at 4 ℃. It was observed that the pale yellow mixed solution became a pale red homogeneous solution after cooling in a refrigerator for 30 minutes, and then a purple complex was observed to be precipitated as a precipitate. The purple complex is the CT complex of the invention: DMP5-P5Q @2 DCM. The schematic diagram of the formation process of the CT complex is shown in FIG. 1.

Example 5 preparation of inventive CT complexes

Referring to the procedure of example 4, P5Q and DMP5 (molar ratio 1: 1) were dissolved in Dichloromethane (DCM) to give two clear DCM solutions (concentration 1.5 mmol. L. each)^-1) Then, the two solutions were mixed to obtain a pale yellow mixed solution, which was placed in a refrigerator at 4 ℃. It was observed that the pale yellow mixed solution became a pale red homogeneous solution after cooling in a refrigerator for 180 minutes, and then a purple complex was observed to be precipitated as a precipitate.

When the CT compound is prepared, under the condition that the proportion of P5Q and DCM is not changed, the higher the concentration of P5Q and DCM is, the faster the compound is formed, and the CT compound can be formed even at normal temperature.

Example 6 preparation of inventive CT complexes

Referring to the procedure of example 4, P5Q and DMP5 (molar ratio 1: 1) were dissolved in Dichloromethane (DCM) to give two clear DCM solutions (concentration 1.0 mmol. multidot.L each)^-1) Then, the two solutions were mixed to obtain a pale yellow mixed solution, which was placed in a refrigerator at 4 ℃. It was observed that after cooling in the refrigerator for 48 hours, the pale yellow mixed solution did not change in color, and no purple complex precipitated.

In preparing the CT complexes of the invention, when DMP5 and P5Q are mixed in DCM at a ratio of 1:1 is less than or equal to 1.0 mmol.L^-1When the mixed solution was left in the refrigerator for 48 hours, no complex was precipitated, and no complex precipitation was observed in DCM solutions of DMP5 and P5Q alone, respectively.

The beneficial effects of the present invention are demonstrated by the following experimental examples.

Experimental example 1 structural characterization of CT composite of the invention

1. Experimental methods

The CT complex DMP5-P5Q @2DCM prepared in example 4 was used as an experimental sample for solid-state UV-Vis spectral test, TGA,¹H NMR and FT-IR tests. P5Q and DMP5 were used as controls.

2. Results of the experiment

The solid state UV-Vis spectral test pattern is shown in figure 2, the FT-IR test pattern is shown in figure 3(a), the TGA result is shown in figure 3(b),¹the H NMR spectrum is shown in FIG. 3 (c).

The precipitated CT complexes were found by solid state UV/Vis spectroscopy to exhibit a distinct charge transfer absorption band at 500-800nm, whereas this absorption band was not found in the solid state UV/Vis spectra of DMP5 or P5Q.¹In the H NMR results, 6.75, 3.77, and 3.64 are absorption peaks of DMP5, 6.77 and 3.50 are absorption peaks of P5Q, and 5.28 is an absorption peak of DCM, indicating that the molecular number ratio of DMP5, P5Q, and DCM in the CT complex prepared in example 4 is 1:1: 2. The TGA results showed 11.95% weight loss of the CT complex and solvent evaporation showed two different temperatures, 40.39 ℃ and 125.07 ℃ respectively, which is comparable to the two aboveThe evaporation results for the individual DCM molecules were consistent, and the difference in evaporation temperature means that the binding sites of the two DCM molecules are different. Furthermore, it was found by FT-IR that the carbonyl stretch band of the DMP5-P5Q @2DCM CT complex was blue-shifted by 5cm compared to P5Q and DMP5^-1Blue shift of ether bond stretching band by 7cm^-1(ii) a In contrast, the FT-IR absorption peak shift of the mixed powder obtained by machine milling equimolar DMP5 and P5Q solids was not significant, suggesting that the templating action of the organic solvent DCM molecules plays a very important role in facilitating the assembly process of the CT complex.

The above results indicate that DMP5 and P5Q can form stable CT complexes in DCM solvent.

Experimental example 2 characterization of crystal form structure of CT composite of the invention

1. Experimental methods

Powder X-ray diffraction analysis (PXRD) was performed using the CT composite obtained in example 4 as an experimental sample. Control was made by machine milling equimolar DMP5 and P5Q solids against P5Q, DMP5 to give a powder blend.

2. Results of the experiment

The PXRD pattern is shown in figure 4. The PXRD pattern of the DMP5-P5Q @2DCM CT complex was found to be significantly different from the PXRD pattern of the supramolecular monomers DMP5 and P5Q, indicating that a crystal structure transition occurred during the formation of the CT complex. In addition, the PXRD pattern of the DMP5-P5Q @2DCM CT complex is also significantly different from the crystal form of the mixed powder obtained by machine milling of equimolar DMP5 and P5Q solids, further illustrating that in the formation of the DMP5-P5Q @2DCM complex, the solvent DCM acts as an important template, resulting in a different stacking method of the crystal form with the DMP5 and P5Q monomers.

Experimental example 3 screening of organic solvent in CT Complex of the present invention

1. Experimental methods

The change of the mixed solution was observed by referring to the method of example 4 while sequentially replacing DCM in example 4 with the organic solvent of this experiment. The organic solvents adopted in the experiment are acetonitrile, acetone, ethyl acetate, chloroform, tetrahydrofuran, tetrachloroethane, anhydrous ether, methanol, toluene, 1, 2-dichloroethane, DMF, n-hexane, cyclohexane and carbon tetrachloride respectively.

The specific operation is as follows: taking P5Q and DMP5 (molar ratio is 1: 1), respectively dissolving in an organic solvent to obtain two clear solutions, then mixing the two solutions to obtain a light yellow mixed solution, placing the light yellow mixed solution in a refrigerator at 4 ℃, and observing the color change of the mixed solution.

2. Results of the experiment

As shown in FIG. 5, it can be seen that P5Q and DMP5 form purple CT complexes in acetonitrile, acetone, ethyl acetate, chloroform, anhydrous ether and tetrahydrofuran in addition to DCM, while the pale yellow color remained in methanol, n-hexane, cyclohexane and carbon tetrachloride, and the purple CT complex could not be separated out. The CT complex DMP5-P5Q @2DCM of the invention has selective chromogenic behavior only in certain specific organic solvents.

Experimental example 4 use of the kit of the present invention as a visual organic solvent indicator

1. Experimental methods

Taking the kit 1 prepared in the example 1 of the present invention, grinding in a mortar 1:1 equimolar mixture of DMP5 and P5Q and cyclohexane was added dropwise thereto and the resulting pasty mixture was dropped on a glass slide and dried. The slide glass on which the mixture was dropped was exposed to each of the common organic solvent vapors shown in table 1, and the color change of the complex on the surface of the slide glass was observed (a schematic diagram is shown in fig. 9). And record t₁，t₂Then, Δ t (Δ t ═ t) is calculated₂-t₁). Wherein t is₁Indicates the time at which the glass slide on which the mixture was dropped began to change color after being exposed to each of the commonly used organic solvent vapors; t is t₂Represents the time required for the color change to complete after the slide on which the mixture was dropped was exposed to each of the commonly used organic solvent vapors; when t is₁＝a，t₂When b, it means that the color of the slide glass on which the mixture was dropped did not change within 90 seconds after the slide glass was exposed to the organic solvent vapor.

2. Results of the experiment

It was found that exposing the slide with the mixture drop to DCM vapor changed the slide surface from pale yellow to purple within 11 s. While the slide with the mixture applied thereto was exposed to ethanol vapor, no color change was exhibited on the slide surface for 90 seconds. The time of color change and the changed color in each common organic solvent vapor are summarized in table 1, and the data in table 1 are arranged into a histogram as shown in fig. 6 n.

It can be seen that the glass slides dropped with equimolar mixture of DMP5 and P5Q are exposed to each common organic solvent vapor, and only the color changes in the vapors of dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform, and tetrahydrofuran occur, and the time for the color to start changing and the time for the color to complete changing are different in different solvent vapors, and the changed colors are slightly different. Therefore, the kit prepared by the invention can simply and conveniently realize the rapid visual identification of common organic solvents by judging whether the steam of the solvent can promote the formation of the CT compound and the formation time and color of the CT compound.

TABLE 1 color change of slides with equimolar mixtures of DMP5 and P5Q exposed to vapors of common organic solvents

Experimental example 5 Activity test of the kit of the present invention as a visual organic solvent indicator

1. Experimental methods

Taking the kit 1 prepared in the invention example 1, after grinding DMP5 and P5Q according to the molar ratio of 1:1, contacting with DCM steam to form CT compound, then using CHCl₃Washing, and vacuum drying at 120 deg.C to completely remove DCM solvent molecules to obtain mixture of DMP5 and P5Q; the experiment was cycled by again contacting the mixture of DMP5 and P5Q with DCM steam.

The resulting mixture was milled at a 1:1 molar ratio of the initial DMP5 to P5Q, and each solvent-stripped mixture of DMP5 and P5Q was subjected to PXRD testing to record the intensity of the absorption peak at 14.26 ° for each PXRD pattern 2 θ. PXRD data for the mixture obtained by grinding the initial DMP5 and P5Q at a 1:1 molar ratio was 100%, and PXRD statistics for the solvent stripped mixture of DMP5 and P5Q obtained after one cycle are shown in fig. 7 (a).

2. Results of the experiment

It can be seen that unlike most known indicator materials, the solvent-mediated CT complex of the present invention formed by P5Q and DMP5 is highly stable and such CT complexes can be made by using CHCl₃The method of washing and vacuum drying at 120 deg.C completely removes DCM solvent molecules for reactivation, which can be reused as indicator material.

Moreover, after 5 times of circulation, the crystal form of the obtained mixture of DMP5 and P5Q after solvent removal and the crystal form of the mixture obtained by grinding the original DMP5 and P5Q according to the molar ratio of 1:1 can still be consistent, which indicates that the mixture can still maintain the activity of forming a CT complex after 5 times of circulation.

Experimental example 6 application of the kit of the invention in writing confidential documents

Using the kit 2-1 prepared in example 2 of the present invention, DMP5 was dissolved in DCM (concentration: 1.5 mmol. multidot.L)^-1) Writing "secret" on white paper, the effect is shown in fig. 8 (a); P5Q was then dissolved in DCM (concentration 1.5 mmol. multidot.L)^-1) The purple character "secret" was immediately displayed on the white paper by spraying with a spray gun, and the effect is shown in FIG. 8 (b).

Therefore, the writing with DCM solvent of DMP5 was not revealed, but the writing was immediately revealed after spraying with DCM solution of P5Q, a property that can be applied to writing security documents.

In summary, the present invention provides a kit, which comprises the following components: the component A comprises: a pillar arene P [ n ]; and B component: the oxidation product PnQ of the column aromatic hydrocarbon. The kit may further comprise a component C: an organic solvent. Experiments of the invention find that the composition obtained by mixing the DMP5 and the P5Q in equimolar mode is exposed to different organic solvent vapors, so that the system has different color changes, and therefore, the rapid visual identification of common organic solvents can be simply realized by judging whether CT complexes are formed in the vapors of different organic solvents or not, and the formation time and the color change of the CT complexes. In addition, the compositions and CT complexes of the invention are highly stable, can be recycled many times, and maintain good activity after 5 cycles. Therefore, the kit has good application prospects in preparation of visual organic solvent indicators, electrochemical sensing and writing of confidential documents.

Claims

1. A kit, characterized in that: the kit comprises the following components:

the component A comprises: a pillar arene P [ n ];

wherein P [ n ] is DMP5, and P [ n ] Q is P5Q:

the molecular number ratio of Pn and PnQ is 1:1, and the common organic solvent to be identified is selected from dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform and tetrahydrofuran.

2. A method for rapidly and visually identifying common organic solvents is characterized by comprising the following steps: the method is carried out using the kit of claim 1, comprising the steps of:

mixing the component A and the component B in the kit according to claim 1, exposing the mixture to a common organic solvent vapor to be identified, and observing the color change;

the common organic solvent to be identified is selected from dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform, tetrahydrofuran.

3. A method for encrypting and decrypting a secure document, comprising: the method is carried out using the kit of claim 1, comprising the steps of:

(a) encryption: dissolving the component A by using a common organic solvent to obtain a solution A; dissolving the component B by using a common organic solvent to obtain a solution B; writing a security document with the solution A;

(b) and (3) decryption: spraying the security document written in the step (a) with the solution B to display the content of the security document;

the common organic solvent is selected from dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform and tetrahydrofuran; the concentration of the solution A and the solution B is 1.5 mmol.L^-1The above.

4. The encryption and decryption method of claim 3, wherein: the concentration of the solution A and the solution B is 1.5-2.0 mmol.L^-1。

5. Use of the kit of claim 1 in the preparation of a visual organic solvent indicator, wherein the organic solvent is one or more selected from dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform and tetrahydrofuran.

6. Use of the kit according to claim 1 for writing security documents.

7. A charge transfer complex, characterized by: the charge transfer complex is formed by Pn, Pn Q and organic solvent molecules in the kit of claim 1, wherein the organic solvent is one or more than two of the following organic solvents: dichloromethane, acetonitrile, acetone, ethyl acetate, chloroform, tetrahydrofuran;

in the charge transfer complex, the ratio of the number of molecules of Pn, Pn Q and organic solvent is 1:1: (1-3).

8. The charge transfer complex of claim 7, wherein: in the charge transfer complex, the ratio of the number of molecules of Pn, Pn Q and organic solvent is 1:1: 2.

9. a charge transfer complex according to any one of claims 7 to 8, wherein: the color of the charge transfer complex is purple.

10. A method of preparing a charge transfer complex according to any one of claims 7 to 9, wherein: the method comprises the following steps:

the kit of claim 1 wherein P [ n ] is]、P[n]Q is respectively dissolved in organic solvent to obtain Pn]Solutions and P [ n ]]Q solution, and then mixing to obtain a mixed solution; standing, and separating out solid, namely a charge transfer compound; the P [ n ]]In solution, P [ n ]]Has a concentration of 1.5 to 2.0 mmol.L^-1(ii) a The P [ n ]]In solution Q, P [ n ]]The concentration of Q is 1.5 to 2.0 mmol.L^-1(ii) a The temperature of the standing is below 4 ℃.