CN113121469A

CN113121469A - Red light material and preparation method and application thereof

Info

Publication number: CN113121469A
Application number: CN202110293517.4A
Authority: CN
Inventors: 刘聪; 杨京莲; 罗运源; 戴慧; 利颖蓉; 石光; 顾凤龙
Original assignee: South China Normal University
Current assignee: South China Normal University
Priority date: 2021-03-19
Filing date: 2021-03-19
Publication date: 2021-07-16
Anticipated expiration: 2041-03-19
Also published as: CN113121469B

Abstract

The invention belongs to the technical field of luminescent materials, and discloses a red light material, and a preparation method and application thereof. The red light material has the structural formula as follows:

wherein D represents an electron donating group and π represents a π conjugated group. The red light material takes benzothiadiazole as a luminescent nucleus, one side of the diazosulfide is connected with an electron donating group, and the other side of the diazosulfide is connected with a secondary amino group and a pi conjugated group to form a D-A type molecule. The red light material is used as a fluorescent probe, has high sensitivity, good selectivity and low detection limit, can simultaneously detect fluorine ions and 2,4, 6-trinitrophenol, and has the detection limit for detecting 2,4, 6-Trinitrophenol (TNP) as low as 5.30 multiplied by 10^‑9mol/L. The preparation method of the red light material is simple.

Description

Red light material and preparation method and application thereof

Technical Field

The invention belongs to the technical field of luminescent materials, and particularly relates to a red light material, and a preparation method and application thereof.

Background

2,4, 6-Trinitrophenol (TNP) is one of the more powerful explosives in the nitroaromatic class, causes huge pollution to soil and water environment, and is a potential soil and water pollutant. The traditional TNP detection method comprises a chromatographic method, an ion transfer method, a spectroscopic method and the like. These methods often require expensive equipment and are complicated and time consuming to operate. The TNP in the water body environment is detected, the content of the TNP in the water body is favorably controlled, the environmental pollution is reduced, and the human health is ensured.

The fluorine ions are the anions with the strongest electronegativity and the smallest ionic radius, and have important functions in the fields of chemistry, biology, medicine and the like. The fluorine ions are one of the trace elements necessary for human body, and a proper amount of fluorine can play the roles of strengthening bones and teeth, preventing the dissolution of the tooth surface and promoting the re-solidification of the dissolved surface, and can effectively prevent and treat dental caries, osteoporosis and the like. However, the metabolism of fluorine ions in human body is very slow, the excessive fluorine will cause permanent and irreversible damage to human body, and the long-term intake of excessive fluorine will cause many diseases and affect growth and development. Therefore, the concentration of fluorine ions in the water body is also concerned.

The detection method of the fluorescent probe has the advantages of high selectivity, high sensitivity, convenience, rapidness, low cost and the like, but the existing fluorescent probe capable of detecting 2,4, 6-trinitrophenol and fluorine ions is less, and the fluorescent probe capable of simultaneously detecting 2,4, 6-trinitrophenol and fluorine ions in water does not exist.

Therefore, it is highly desirable to provide a fluorescent probe capable of detecting 2,4, 6-trinitrophenol and fluoride ions simultaneously.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a red light material, and the red light material is used for preparing a fluorescent probe and can be used for simultaneously detecting 2,4, 6-trinitrophenol and fluorine ions.

A red light material has a structural formula as follows:

wherein D represents an electron donating group and π represents a π conjugated group.

Preferably, the electron donating group is an aniline or carbazole containing group.

Further preferably, the electron-donating group is one selected from the group consisting of groups represented by formula (1), formula (2) and formula (3),

preferably, the pi conjugated group is an aromatic group; further preferably, the pi conjugated group is at least one selected from the group consisting of groups represented by formula (4), formula (5), formula (6) and formula (7),

wherein R is₁、R₂、R₃And R₄Each independently represents-H, -NO₂-CN, -CHO or-CF₃One kind of (1).

Preferably, the red light material is a compound with a structural formula shown as a formula (8) or a formula (9),

the invention also provides a preparation method of the red light material, which comprises the following steps:

(1) preparing an intermediate containing an electron donating group and benzothiadiazole;

(2) adding an aromatic compound containing secondary amine groups into the intermediate prepared in the step (1) to prepare the red light material.

Specifically, the preparation method of the red light material comprises the following steps:

(1) a compound containing a benzothiadiazole structure, a compound containing an aniline or carbazole structure, and Cs₂CO₃And Ruphos (2-dicyclohexylphosphine-2 ', 6' -diisopropoxybiphenyl) and a catalyst are dissolved in a solvent, mixed, reacted, cooled and extracted to prepare the intermediate.

(2) Adding aromatic compounds containing secondary amino and Cs into the intermediate prepared in the step (1)₂CO₃And Ruphos (2-dicyclohexylphosphine-2 ', 6' -diisopropoxybiphenyl) and a catalyst are dissolved in a solvent, and the red light material is prepared by mixing, reacting, cooling and extracting.

Preferably, the temperature of the reaction in the step (1) is 110-120 ℃, and the time of the reaction in the step (1) is 12-48 h.

Preferably, the temperature of the reaction in the step (2) is 110-120 ℃, and the time of the reaction in the step (1) is 12-48 h.

Preferably, the aromatic compound containing a secondary amine group in step (2) is p-aminobenzonitrile.

The invention also provides application of the red light material in preparation of a fluorescent probe.

The application of the red light material in detecting fluoride ions.

The red light material is applied to detection of 2,4, 6-trinitrophenol.

According to the red light material provided by the invention, benzothiadiazole is used as a luminescent nucleus, is an extremely strong electron-withdrawing group and has a large Stokes shift (Stokes shift), one side of the benzothiadiazole is connected with the electron-withdrawing group to form a D-A structure, and a propeller structure is formed, so that intermolecular pi-pi accumulation is inhibited, and the luminous efficiency is enhanced; the other side is connected with a secondary amine group, an intramolecular hydrogen bond is easily formed, and excited state proton transfer (ESIPT) occurs. The red light material has Aggregation Induced Emission (AIE) and Intramolecular Charge Transfer (ICT) properties, contains a strong electron-withdrawing group, is favorable for deprotonation of molecules, and is favorable for detecting fluorine ions and 2,4, 6-trinitrophenol.

Compared with the prior art, the invention has the following beneficial effects:

(1) the red light material provided by the invention takes benzothiadiazole as a luminescent nucleus, one side of the benzothiadiazole is connected with an electron donating group, and the other side of the benzothiadiazole is connected with a secondary amino group and a pi conjugated group to form a D-A type (containing a donor and an acceptor) molecule. The red light material can be used as a fluorescent probe, and has high sensitivity, good selectivity and low detection limit. Can simultaneously detect fluorinion and 2,4, 6-trinitrophenol, and the detection limit for detecting 2,4, 6-Trinitrophenol (TNP) is as low as 5.30 multiplied by 10^-9mol/L。

(2) The preparation method of the red light material provided by the invention is simple.

Drawings

FIG. 1 is a mass spectrum of a red-light material prepared in example 1;

FIG. 2 is a mass spectrum of a red-light material prepared in example 2;

FIG. 3 is a graph showing fluorescence spectra of the red-emitting material prepared in example 1 in different solvents;

FIG. 4 is a graph showing fluorescence spectra of the red-emitting material prepared in example 2 in different solvents;

FIG. 5 shows DMSO/H of the red light material prepared in example 1 at different volume fractions of water₂Fluorescence spectrum in O solution;

FIG. 6 is a graph showing the fluorescence intensity of the red-emitting material prepared in example 1 in different volume fractions of water;

FIG. 7 shows DMSO/H of red light materials prepared in example 2 at different water volume fractions₂Fluorescence spectrum in O solution;

FIG. 8 is a graph showing the fluorescence intensity of the red-emitting material prepared in example 2 in different volume fractions of water;

FIG. 9 is a graph showing the fluorescence spectra of the red-emitting material prepared in example 1 with different anions added;

FIG. 10 is a graph of the UV-VIS absorption spectra of the red-emitting materials prepared in example 2 with different anions added;

FIG. 11 is a graph showing the fluorescence spectra of the red-emitting material prepared in example 2 with different anions added;

FIG. 12 is a fluorescence spectrum of the red-emitting material prepared in example 1 for detecting different nitro explosives;

FIG. 13 is a graph of the fluorescent titration of TNP for red-emitting materials prepared in example 1;

FIG. 14 shows the results of measurement I of the red-emitting material obtained in example 1₀The trend of the/I-1 value with the TNP concentration;

FIG. 15 shows the results of measurement I of the red-light emitting material obtained in example 1₀-a fitted curve of I versus TNP concentration;

FIG. 16 is a fluorescence spectrum of the red-emitting material prepared in example 2 for detecting different nitro explosives;

FIG. 17 is a graph of the fluorescent titration of TNP for red-emitting materials prepared in example 2;

FIG. 18 shows the results of measurement I of the red-emitting material obtained in example 2₀The trend of the/I-1 value with the TNP concentration;

FIG. 19 shows the results of the detection of red light materials prepared in example 2₀-I fitted curve to TNP concentration.

Detailed Description

In order to make the technical solutions of the present invention more apparent to those skilled in the art, the following examples are given for illustration. It should be noted that the following examples are not intended to limit the scope of the claimed invention.

The starting materials, reagents or apparatuses used in the following examples are conventionally commercially available or can be obtained by conventionally known methods, unless otherwise specified.

Example 1

A red light material has the following structural formula (mass spectrum shown in figure 1):

the preparation method of the red light material comprises the following steps:

(1) preparation of intermediate DP-BTD-Br

A250 mL three-necked flask was charged with 1.76g (6mmol) of 4, 7-dibromo-2, 1, 3-benzothiadiazole, 0.85g (5mmol) of diphenylamine, and Cs₂CO₃4g (8.7mmol) and 0.10g (0.3mmol) of Ruphos were dissolved in 25mL of toluene, magnetically stirred and bubbled with Ar gas for 40 minutes, then the reaction temperature was adjusted to 110 ℃ and 3mg of catalyst Pd was added₂(dba)₃And reacting for 24 hours under an Ar atmosphere. The reaction was cooled to room temperature, then poured into saturated brine, extracted three times with dichloromethane, dried with excess anhydrous magnesium chloride, vacuum filtered, rotary evaporated to give an orange solid, the crude product was further purified by silica gel column chromatography (eluent DCM/PE ═ 1: 10) to give an orange solid, yield: 62.1 percent. The results of nuclear magnetic characterization were:¹H NMR(600MHz,CDCl₃)δ7.68(d,J＝8.0Hz,1H),7.29–7.27(m,3H),7.26(s,1H),7.09(t,J＝7.4Hz,2H),7.05(dd,J＝8.5,1.0Hz,4H),7.03(d,J＝8.0Hz,1H).ESI-MS m/z:[M]⁺calcd.for 382.2770；found,382.0007。

(2) preparation of Red light Material DP-BTD-CN

Taking 0.24g (0.63mmol) of DP-BTD-Br prepared in the step (1), and 0.063g (0.53mmol) of para-aminobenzonitrile, Cs₂CO₃0.39g (1.2mmol) and 0.0140g (0.03mmol) of Ruphos were dissolved in 25mL of toluene, magnetically stirred and bubbled with Ar gas for 40 minutes, then the reaction temperature was adjusted to 110 ℃ and 3mg of catalyst Pd was added₂(dba)₃And reacting for 24 hours under an Ar atmosphere. Cooling the reaction system to room temperature, then pouring the reaction system into saturated salt water, extracting the mixture by dichloromethane for three times, adding excessive anhydrous magnesium chloride, drying the mixture overnight, carrying out vacuum filtration and rotary evaporation to obtain a brick red solid, and further purifying the crude product by silica gel column chromatography (eluent is DCM/PE ═ 3:1) to obtain the brick red solid, wherein the yield is as follows: 86.4 percent. The results of nuclear magnetic characterization were:¹H NMR(600MHz,DMSO)δ9.43(s,1H),7.66(d,J＝8.7Hz,2H),7.45(d,J＝8.0Hz,1H),7.35(d,J＝8.8Hz,2H),7.29(d,J＝8.0Hz,1H),7.24(t,J＝7.9Hz,4H),6.99(d,J＝8.1Hz,4H),6.97(s,2H).¹³C NMR(151MHz,DMSO)δ152.14,150.44,147.25,133.47,132.39,130.49,129.24,127.69,122.37,122.34,119.73,116.69,114.41,100.76.ESI-MS m/z:[M]⁺calcd.for 419.5051；found,418.1133。

example 2

The red light material has the following structural formula (mass spectrum shown in figure 2):

the preparation method of the red light material comprises the following steps:

(1) preparation of intermediate DP-BTD-Br

(2) preparation of red light material DP-BTD-TPE

Taking 0.27g (0.7mmol) of DP-BTD-Br prepared in the step (1), 0.12g (0.36mmol) of 1- (4-aminobenzene) -1,2, 2-triphenylethylene and Cs₂CO₃0.26g (0.8mmol) and 0.0140g (0.03mmol) of Ruphos were dissolved in 25mL of toluene, magnetically stirred and bubbled with Ar gas for 40 minutes, then the reaction temperature was adjusted to 110 ℃ and 3mg of catalyst Pd was added₂(dba)₃And reacting for 24 hours under an Ar atmosphere. The reaction system is cooled to room temperature, then poured into saturated salt water, extracted by dichloromethane for three times,excess anhydrous magnesium chloride was added, dried overnight, vacuum filtered, rotary evaporated to give a red solid, and the crude product was further purified by silica gel column chromatography (DCM/PE ═ 1:1 as eluent) to give a red solid in yield: 82.6 percent. The results of nuclear magnetic characterization were:¹H NMR(600MHz,DMSO)δ8.81(s,1H),7.28(d,J＝8.0Hz,1H),7.23–7.20(m,3H),7.20–7.19(m,1H),7.18–7.14(m,5H),7.10(dtd,J＝13.1,9.4,4.5Hz,7H),7.04–7.01(m,4H),6.97–6.92(m,8H),6.92–6.88(m,2H).¹³C NMR(151MHz,DMSO)δ152.58,149.49,147.32,143.56,143.47,143.38,140.37,140.03,139.82,136.42,133.84,131.58,130.76,130.04(s,2H),129.19,128.82,127.92,127.83,127.80,126.53,126.47,126.39,121.88,121.64,118.52,107.42.ESI-MS m/z:[M]⁺calcd.for 648.2348；found,647.2277。

product effectiveness testing

1. The light emitting properties of the red light emitting materials prepared in examples 1 and 2 were measured

Both the DP-BTD-CN molecule (prepared from example 1) and the DP-BTD-TPE molecule (prepared from example 2) contain the strongly electron withdrawing group Benzothiadiazole (BTD) and the electron donating group Diphenylamine (DP), belonging to the D-A type of molecules. Fluorescence emission spectra of the two red light materials in different organic solvents are tested, and FIGS. 3 and 4 are fluorescence spectra of DP-BTD-CN molecules and DP-BTD-TPE molecules in different solvents respectively. In FIG. 3, the abscissa is the wavelength and the ordinate is the standard light intensity, and the curves in FIG. 3 are spectra in the direction of the arrows in CH (cyclohexane), TOL (toluene), THF (tetrahydrofuran), DCM (dichloromethane), DMF (dimethylformamide) and DMSO (dimethylsulfoxide). In FIG. 4, the abscissa is the wavelength and the ordinate is the standard light intensity, and the curves in FIG. 4 are spectra in TOL (toluene), THF (tetrahydrofuran), DCM (dichloromethane), DMF (dimethylformamide) and DMSO (dimethyl sulfoxide) in the direction of the arrows. As can be seen from FIGS. 3-4, the fluorescence spectra of DP-BTD-CN and DP-BTD-TPE are significantly red-shifted with increasing polarity of the solvent, and the maximum emission wavelength of DP-BTD-CN is red-shifted by 88nm, indicating that the excited state of the molecule is influenced by the solvent and has Intramolecular Charge Transfer (ICT) property.

2. The red-emitting materials prepared in examples 1 and 2 were tested for their aggregation-induced emission properties

FIG. 5 shows DMSO/H of DP-BTD-CN molecules (prepared from example 1) at different volume fractions of water₂Fluorescence spectrum in O solution. In fig. 5, the abscissa is the wavelength and the ordinate is the intensity, and the curves in fig. 5 are spectra in which the volume of water is 80%, 90%, 0%, 70%, 10%, 30%, 50%, and 60% in the direction of the arrow.

FIG. 6 is a graph showing the change in fluorescence intensity of DP-BTD-CN molecules (prepared in example 1) in different volume fractions of water. In fig. 6, the abscissa is the volume fraction of water, and the ordinate is the fluorescence intensity.

FIG. 7 shows DMSO/H in different volume fractions of water for DP-BTD-TPE molecules (prepared in example 2)₂Fluorescence spectrum in O solution; in fig. 7, the abscissa is the wavelength and the ordinate is the intensity, and the curve in fig. 7 is a spectrum diagram in the direction of the arrow in the order of 50%, 70%, 90%, 30%, 0%, 10% and 20% of the volume of water.

FIG. 8 is a graph showing the change in fluorescence intensity of DP-BTD-TPE molecules (prepared in example 2) in different volume fractions of water. In fig. 8, the abscissa is the volume fraction of water, and the ordinate is the fluorescence intensity.

As can be seen from FIGS. 6 to 8, the fluorescence intensity of the compound gradually increased after decreasing with the increase of the proportion of the poor solvent water, indicating that the molecule has aggregation-induced emission properties.

3. Application of red light material prepared in examples 1 and 2 in fluorescence sensing

(1) Test Red Material Pair F^-Selectivity and sensitivity of

The prepared red light emitting materials of example 1 and example 2 were used to prepare a detection solution (2.0X 10)^-5mol/L), respectively testing initial ultraviolet and fluorescence spectra under the excitation wavelength of 365nm, and then respectively adding different anions ((AcO)^-、NO₃ ^-，HSO₄ ^-，H₂PO₄ ^-，Br^-，Cl^-，I^-) And F) and^-and testing ultraviolet and fluorescence spectra. The DP-BTD-CN solution shows red light, and after F-is added, the color of the solution is brightIt changes to blue and remains red after addition of other anions.

FIG. 9 is a graph showing fluorescence spectra of the red light material (DP-BTD-CN) obtained in example 1, in which the abscissa is wavelength and the ordinate is light intensity, to which different anions were added. As can be seen from FIG. 9, different anions (AcO) were added to the DP-BTD-CN solution^-、NO₃ ^-，HSO₄ ^-，H₂PO₄ ^-，Br^-，Cl^-，I^-) After that, the fluorescence spectrum did not change significantly, but F was added^-And then, the color of the solution is changed, and the fluorescence spectrum is obviously quenched, which shows that the F-can be selectively detected.

FIG. 10 is a graph showing UV-VIS absorption spectra of the red-emitting material (DP-BTD-TPE) prepared in example 2 with different anions, wherein the abscissa is wavelength and the ordinate is light intensity. FIG. 11 is a fluorescence spectrum of the red-light material prepared in example 2 with different anions added, wherein the abscissa is wavelength and the ordinate is light intensity. As can be seen from FIGS. 10 and 11, the DP-BTD-TPE solution (10)^-4mol/L) addition of different anions (AcO)^-、NO₃ ^-，HSO₄ ^-，H₂PO₄ ^-，Br^-，Cl^-，I^-) And then, an ultraviolet visible absorption spectrogram and a fluorescence spectrogram do not change obviously, but the ultraviolet spectrum changes obviously after the F-is added, and the fluorescence spectrogram is quenched obviously, so that the selective detection of the F-can be realized.

(2) Testing selectivity and sensitivity of red light material to explosive

The red light material of example 1 was formulated into a solution (DMSO/H)₂O ═ 2:8), the initial fluorescence spectra were measured at an excitation wavelength of 365nm, and then different nitro explosives (9 × 10) were added^-5mol/L), detecting the fluorescence spectrum of the added different nitro explosives, and testing the selectivity of the nitro explosives.

FIG. 12 shows that the red-light material prepared in example 1 can detect different nitro-explosives (9X 10)^-5mol/L) in which the abscissa is wavelength and the ordinate is fluorescence intensity, the curve in FIG. 12The line is blank along the direction of the arrow, and the fluorescence spectrograms of NT (p-nitrotoluene), NB (nitrobenzene), TNT (2, 4, 6-trinitrotoluene), NP (p-nitrophenol), DNP (2, 4-dinitrophenol) and TNP (2, 4, 6-trinitrophenol) are shown in figure 12, and the fluorescence spectrogram is obviously quenched after the TNP is added, which shows that the TNP has selectivity.

FIG. 13 is a graph of the fluorescence titration TNP of the red-light emitting material obtained in example 1, in which the abscissa is the wavelength and the ordinate is the fluorescence intensity, and FIG. 13 shows the dropping concentration of 0 to 9.0X 10 to the red-light emitting material solution obtained in example 1^-5As can be seen from FIG. 13, the fluorescence intensity of TNP at mol/L (i.e., 0-90. mu.M) decreases with increasing concentration of TNP.

Further combining with the Stem-Volmer theory to calculate the formula Ksv [ C ]]＝I₀1, [ I ] by treatment of different concentrations of TNP₀I) -1, wherein I₀Is the initial fluorescence intensity, I is the fluorescence intensity after quenching, linear fitting is carried out on the initial fluorescence intensity and the fluorescence intensity after quenching to obtain a linear equation, and the quenching combination constant Ksv is obtained from the slope and is 3.51 multiplied by 10⁴L/mol; FIG. 14 shows the results of measurement I of the red-emitting material obtained in example 1₀The trend of the/I-1 values with TNP concentration (the upper inset is the fitted curve).

At the same time, the TNP detection limit was tested. The limit of detection (LOD) refers to the minimum concentration or amount of a test substance that can be detected from a sample by an analytical method within a given degree of reliability, and is calculated by the formula: LOD is 3 sigma/m; adding TNP with different concentrations into the detection solution to obtain TNP fluorescence quenching curves with different concentrations, and passing through the TNT concentrations [ C ]]And I₀-I is plotted, wherein I₀As initial fluorescence intensity, I is fluorescence intensity after quenching, and a linear fit is made thereto, FIG. 15 is I at the time of detection using the red-light material obtained in example 1₀Fitting a curve of the relation between the concentration of the I and the concentration of the TNP to obtain a linear equation, wherein the slope of the linear equation is m, simultaneously testing the fluorescence intensity of the blank sample solution without adding the TNT, testing 6 groups, calculating the fluorescence intensity of the highest point of the fluorescence emission wavelength of the 6 groups of data according to a standard deviation formula to obtain the standard deviation sigma of the blank sample, and obtaining the standard deviation sigma of the blank sampleSubstituting the m and the sigma into a detection limit calculation formula to obtain the detection limit of the TNP.

Wherein the detection limit calculation formula is as follows: LOD is 3 sigma/m,

wherein K_SV＝3.51×10⁴L/mol，σ＝12.68，m＝2.42×10⁹，

Calculating to obtain: LOD is 1.57 × 10^-8mol/L。

The red light material of example 2 was prepared as a solution (DMSO/H2O ═ 6:4), and the initial fluorescence spectra were measured at an excitation wavelength of 365nm, after which different nitro explosives (9 × 10) were added, respectively^-5mol/L), detecting the fluorescence spectrum of the added different nitro explosives, and testing the selectivity of the nitro explosives.

FIG. 16 shows that the red-light material prepared in example 2 can detect different nitro-explosives (9X 10)^-5mol/L), wherein the abscissa is the wavelength and the ordinate is the fluorescence intensity, the curves in FIG. 16 are the fluorescence spectra of DP-BTD-TPE (DP-BTD-TPE is blank, NT overlaps with DP-BTD-TPE), NB, TNT, NP, DNP and TNP in sequence along the direction of the arrow, as can be seen from FIG. 16, the fluorescence spectra are significantly quenched after the addition of TNP, indicating that the selectivity to TNP is provided.

FIG. 17 is a graph of the fluorescence titration TNP of the red-light emitting material obtained in example 2, in which the abscissa is the wavelength and the ordinate is the fluorescence intensity, and FIG. 17 shows the dropping concentration of 0 to 9.0X 10 to the red-light emitting material solution obtained in example 2^-5As can be seen from FIG. 17, the fluorescence intensity of TNP at mol/L (i.e., 0-90. mu.M) decreases with increasing concentration of TNP.

FIG. 18 shows the results of measurement I of the red-emitting material obtained in example 2₀The trend of the/I-1 values with TNP concentration (the upper inset is the fitted curve). FIG. 19 shows the results of the detection of red light materials prepared in example 2₀-I fitted curve to TNP concentration.

Calculating a detection limit according to the data, wherein the detection limit calculation formula comprises the following steps: LOD is 3 sigma/m,

wherein, K_SV＝4.06×10⁴L/mol，σ＝12.51，m＝7.08×10⁹，

Calculating to obtain: LOD 5.30 × 10^-9mol/L。

Comprehensively, the following steps are carried out: the red light material provided by the invention has a good response effect on TNP, has high selectivity, low detection limit and high TNP detection efficiency.

Claims

1. A red light material is characterized in that the structural formula is as follows:

2. The red-light material of claim 1, wherein the electron donating group is an aniline or carbazole containing group.

3. The red light-emitting material of claim 2, wherein the electron-donating group is selected from one of the groups represented by formula (1), formula (2), or formula (3),

4. the red-light material of claim 1, wherein the pi conjugated group is an aromatic group.

5. The red-light-emitting material according to claim 4, wherein the pi-conjugated group is at least one selected from the group consisting of groups represented by formula (4), formula (5), formula (6), and formula (7),

wherein R is₁、R₂、R₃And R₄Are respectively provided withIndependently represent-H, -NO₂-CN, -CHO or-CF₃One kind of (1).

6. The red light emitting material according to any one of claims 1 to 5, wherein the structural formula of the red light emitting material is a compound represented by formula (8) or formula (9),

7. the method for preparing a red-light emitting material according to any one of claims 1 to 6, comprising the steps of:

8. Use of the red-emitting material of any one of claims 1 to 6 in the preparation of a fluorescent probe.

9. Use of the red-emitting material of any one of claims 1 to 6 for detecting fluoride ions.

10. Use of the red-emitting material of any one of claims 1-6 for detecting 2,4, 6-trinitrophenol.