Preparation method of water-soluble colorimetric probe based on hydrogen bonds and application of water-soluble colorimetric probe in anion recognition

Abstract

The invention discloses a preparation method of a water-soluble colorimetric probe based on hydrogen bonds and application of the water-soluble colorimetric probe in anion recognition. The preparation method comprises the following steps: carrying out a Schiff base condensation reaction on an aldehyde group derivative of a xanthene or triphenylmethane indicator (such as phenolphthalein) and an aminoguanidine derivative to obtain a type I probe, and carrying out a reduction reaction to obtain a type II probe. The prepared two types of colorimetric probes can identify F <->, AcO <-> and SO4 < 2-> anions in water with high selectivity and high sensitivity, and can realize visual detection through obvious color change. A binding constant gt calculated by an ultraviolet-visible titration experiment; the water-based anion probe is superior to most of existing water-based anion probes. The probe has the advantages of low raw material cost, simple and convenient synthesis steps, quick response, obvious colorimetric signal and the like, and has a good application prospect in the fields of anion recognition, environmental pollutant detection, water treatment and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of supramolecular chemistry and sensor technology, and particularly relates to a water-soluble colorimetric probe based on hydrogen bond and anion recognition application. BACKGROUND

[0002] It is always a core challenge in the field of supramolecular chemistry to realize the high selectivity recognition of anions in aqueous environment, and the main difficulty lies in that water molecules have a strong solvation ability, which can seriously weaken the interaction force between host molecules and anion guests. At present, the common anion recognition strategy mostly depends on the interaction between hydrogen bond donor groups such as amide, urea and thiourea and target anions, and although such systems can realize effective combination under specific conditions, the recognition performance is often greatly attenuated in water environment due to the fierce solvation competition. In addition, such receptor molecules generally have problems such as complicated synthesis path, low yield, and lack of sensitive optical signal (such as color or fluorescence) output, which greatly limits their practical application. Therefore, anion receptor materials with high selectivity, high sensitivity and significant signal output in aqueous phase are still very scarce. It is of great significance to develop new host molecules with specific response function to anions for the fields of environmental monitoring, biomedical diagnosis and the like.

[0003] Phenolphthalein and other triphenylmethane indicator molecules are a typical lactone type non-planar molecule, which is widely used as an acid-base indicator because it can undergo significant and reversible color change under acid-base stimulation. The color change mechanism is due to the reversible opening and closing of the lactone ring: under alkaline conditions, the lactone ring is opened, the molecular coplanarity and conjugation degree are increased, which leads to red shift of the absorption spectrum and coloration; on the contrary, acidification restores the structure and fades the color. Although phenolphthalein and other indicators have excellent optical response characteristics, there is no systematic report on the use of them as a core skeleton to construct anion recognition host. On the other hand, guanidinium group can provide multiple hydrogen bond sites and form strong non-covalent interaction with anions, and is considered as a kind of anion binding unit with great potential. In view of this, the excellent coloration characteristics of phenolphthalein are combined with the guanidinium group with rich action sites to design and construct a new type of anion response colorimetric probe, which is expected to realize the visual detection of anions. It provides an innovative path to solve the problem of anion recognition in aqueous phase, and has wide application prospect. SUMMARY

[0004] The present application aims at the deficiencies of existing anion receptors, such as poor water solubility, complicated synthesis steps, lack of effective signal sensing unit, poor anion bonding, etc., and proposes a kind of indicator type molecule and guanidine group combination, by means of the color change function of indicator and the hydrogen bond ability of guanidine group, a simple water-soluble colorimetric anion receptor is constructed.The receptor molecule has the advantages of easy raw material, simple synthesis, good water solubility, rapid anion response and naked eye visual identification.

[0005] The present application is implemented by the following technical solutions: The present application discloses a water-soluble colorimetric anion probe based on hydrogen bond, the colorimetric anion probe includes I type probe and II type probe, the I type probe and II type probe are all composed of amino guanidine and its derivative and xanthene or triphenylmethane indicator molecule two parts, the structural formula is as shown in formula (1) and formula (2), Formula (1) I type probe, Formula (2) II type probe, Wherein, R represents xanthene or triphenylmethane molecular derivative.

[0006] The xanthene or triphenylmethane molecular derivative, preferably, R can be mainly selected from the compound shown in the following formula (3), wherein the site of R part connected with amino guanidine group is the ortho position of phenolic hydroxyl group; Formula (3); The R part includes but is not limited to the structure in formula (3).

[0007] The second part of the present application discloses the preparation method of the water-soluble colorimetric anion probe, including formylation modification of R part structure, Schiff base condensation reaction of aldehyde modified R part and amino guanidine group to prepare I type probe and II type probe obtained by reducing I type probe.

[0008] Specifically, the following steps are included: S1.reaction of xanthene or triphenylmethane indicator molecule and hexamethylenetetramine in trifluoroacetic acid, acid hydrolysis to obtain aldehyde derivative; S2 reflux reaction of aldehyde derivative obtained in step S1 with amino guanidine hydrochloride in organic solvent to obtain I type probe; S3. the I type probe obtained in step S2 is reduced with sodium borohydride to obtain II type probe.

[0009] Further, the I type probe mainly refers to the structure of imine C=N bond, and the II type probe refers to the structure of corresponding I type probe reduced to C-N single bond.

[0010] Further, in step S1, xanthene or triphenylmethane indicator molecules 2-4 g, hexamethylenetetramine 10-15 equivalents, trifluoroacetic acid 40-80 mL, under nitrogen protection, 80-100 °C for 3-24 h, after the reaction, add 3M hydrochloric acid aqueous solution 100-300 mL, hydrolysis at 100 °C for 1-2 h, cool to room temperature, suction filtration, water washing, drying to obtain yellow powder, then purified by silica gel column chromatography to obtain aldehyde derivatives.

[0011] Further, in step S2, aldehyde derivatives 2 mmol, amino guanidine hydrochloride 4 equivalents or 8 equivalents, reflux in organic solvent for 12 h, cool to room temperature, filter and rinse with organic solvent, vacuum drying to obtain type I probe; the organic solvent is acetonitrile or N,N-dimethylformamide.

[0012] Further, in step S3, in step S3, 2 mmol of type I probe is dissolved in 50-300 mL of ethanol, 10 equivalents of sodium borohydride are added, and reflux reaction is carried out for 48 h. After the reaction, 0.1M hydrochloric acid is used to adjust the pH to 10. During the pH adjustment, a large amount of solid powder is precipitated from the solution. Centrifugation and washing of the precipitate with deionized water, vacuum drying, to obtain type II probe.

[0013] According to an embodiment of the present application, a method for preparing a hydrogen bond-based water-soluble colorimetric probe comprises the following steps: S1. Synthesis of aldehyde derivatives of xanthene or triphenylmethane molecules (In-CHO) (formula 4, taking R3 as an example): 2-4 g of xanthene or triphenylmethane molecules, 10-15 equivalents of hexamethylenetetramine and 40-80 mL of trifluoroacetic acid are mixed, and reacted at 80-100 °C under nitrogen protection for 3-24 h; after the reaction is completed, 3M hydrochloric acid aqueous solution (100-300 mL) is added, hydrolysis at 100 °C for 1-2 h, cool to room temperature, suction filtration, water washing, drying to obtain yellow powder, then purified by 200 mesh silica gel column chromatography (eluent: dichloromethane / methanol) to obtain dialdehyde In-CHO (formula 5); .

[0014] S2. Synthesis of probe I (formula 6, taking R3 as an example): 2 mmol of aldehyde derivatives In-CHO, 4 (for dialdehyde) or 8 (for tetraaldehyde) equivalents of amino guanidine hydrochloride are dissolved in an appropriate amount of organic solvent, and refluxed for 12 h. Cool to room temperature, filter and rinse with organic solvent, 60 °C vacuum drying to obtain the product probe I (formula 6); .

[0015] S3. Synthesis of probe II (formula 7): 2 mmol of probe I is dissolved in 50-300 mL of ethanol, 10 equivalents of sodium borohydride reducing agent are dissolved in an appropriate amount of ethanol, and are slowly added to the above probe I solution in batches, refluxed for 48 h, cooled to room temperature, and the filtrate is dissolved to obtain a solid crude product, 80-500 mL of deionized water is added until it is completely dissolved, and the solution is adjusted to pH 10 using 0.1 M hydrochloric acid. During the pH adjustment, a large amount of solid powder is precipitated from the solution, which is centrifuged and washed with deionized water, and vacuum dried at 60°C for 12 h to obtain probe II (formula 7).

[0016] .

[0017] Further, the preparation of the aldehyde derivative of the xanthene or triphenylmethane molecule (In-CHO) in step S1 includes but is not limited to the following structure (formula 8): .

[0018] The third aspect of the present application discloses the application of the water-soluble colorimetric anion probe in preparing an anion detection reagent.

[0019] Further, the water-soluble colorimetric anion probe can be dissolved in pure water and exhibits a yellow-green color.

[0020] Further, the anion is one or more of acetate ion, sulfate ion or fluoride ion.

[0021] Further, the water-soluble colorimetric anion probe can produce a significant discoloration phenomenon for one or more of trace (10 -5 M) acetate, sulfate and fluoride ions in water, and the ultraviolet-visible spectrum shows that the discoloration range is 300-600 nm.

[0022] Further, the probe forms multiple hydrogen bonds with the anion through the NH on the amino guanidine group, and the binding stoichiometry of the probe and the anion is 1:2.

[0023] Advantages of the present application: The present application only needs 2-3 steps to synthesize two types of water-soluble, fast-responding and naked-eye visible anion receptors, which have a rapid discoloration response to one or more of trace acetate, sulfate and fluoride ions in water, and have high selectivity and anti-interference. The Job curve shows that the binding ratio of the receptor-anion is 1:2, and the binding constant logβ calculated by the ultraviolet-visible titration experiment is >10 3 M -2 The receptor has the advantages of low cost, simple synthesis, rapid response and visual detection in pure water. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and are meant to explain the present application and are not intended to limit the application. In the drawings: Figure 1 : Schematic diagram of chemical equation of reaction of preparation method of the present application.

[0025] Figure 2 : NMR hydrogen spectrum chart (400MHz, DMSO-d6) of colorimetric probe 1 in Example 1.

[0026] Figure 3 : NMR hydrogen spectrum chart (400MHz, DMSO-d6) of colorimetric probe 1 in Example 1. 1 H- 1 HNoesy spectrum chart (400MHz, DMSO-d6).

[0027] Figure 4 : NMR carbon spectrum chart (400MHz, DMSO-d6) of colorimetric probe 1 in Example 1.

[0028] Figure 5 : Mass spectrum chart of colorimetric probe 1 in Example 1.

[0029] Figure 6 : Colorimetric response of colorimetric probe 1 in Example 1 to AcO - , SO4 2- and F - in water.

[0030] Figure 7 : UV-vis absorption spectrum of colorimetric probe 1 in Example 1 after adding various anions.

[0031] Figure 8 : AcO - UV-visible titration curve of colorimetric probe 1 in Example 1.

[0032] Figure 9 : SO4 2- UV-visible titration curve of colorimetric probe 1 in Example 1.

[0033] Figure 10 : F - UV-visible titration curve of colorimetric probe 1 in Example 1.

[0034] Figure 11 : Synthesis route of colorimetric probe 2 in Example 2.

[0035] Figure 12 : NMR hydrogen spectrum chart (400MHz, DMSO-d6) of colorimetric probe 2 in Example 2.

[0036] Figure 13 : 2D H-H COSY spectrum of colorimetric probe 2 in Example 2 (400 MHz, DMSO-d6).

[0037] Figure 14 : 13C NMR spectrum of colorimetric probe 2 in Example 2 (400 MHz, DMSO-d6).

[0038] Figure 15 : Color change photographs of colorimetric probe 2 in Example 2 upon addition of various anions.

[0039] Figure 16 : UV-vis absorption spectra of colorimetric probe 2 in Example 2 upon addition of various anions.

[0040] Figure 17 : UV-vis titration absorption spectra of colorimetric probe 2 in Example 2 upon addition of AcO - .

[0041] Figure 18 : UV-vis titration absorption spectra of colorimetric probe 2 in Example 2 upon addition of SO4 2- .

[0042] Figure 19 : Synthetic route of colorimetric probe 3 in Example 3.

[0043] Figure 20 : 1H NMR spectrum of colorimetric probe 3 in Example 3 (400 MHz, DMSO-d6).

[0044] Figure 21 : 13C NMR spectrum of colorimetric probe 3 in Example 3 (400 MHz, DMSO-d6).

[0045] Figure 22 : Mass spectrum of colorimetric probe 3 in Example 3 (400 MHz, DMSO-d6).

[0046] Figure 23 : Color change photographs of colorimetric probe 3 in Example 3 upon addition of various anions.

[0047] Figure 24 : UV-vis absorption spectra of colorimetric probe 3 in Example 3 upon addition of various anions (full spectra).

[0048] Figure 25 : UV-vis absorption spectra of colorimetric probe 3 in Example 3 upon addition of various anions (partial).

[0049] Figure 26 : UV-vis absorption spectra of colorimetric probe 3 in Example 3 upon addition of various AcO -UV-vis titration absorption spectra after. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the present application more clear to the person skilled in the art, the specific embodiments of the present application are further described in detail below combined with specific examples and drawings, so as to define the protection scope of the present application.

[0051] Example 1: Preparation of colorimetric probe 1 (type I probe) of the present application and its recognition of AcO - , SO4 2- and F - .

[0052] Take 4g of phenolphthalein, 15 equivalents (relative to phenolphthalein) of hexamethylenetetramine and 80mL of trifluoroacetic acid, mix under argon atmosphere at 100℃ for 24h, add 3M aqueous hydrochloric acid solution (300mL), hydrolyze at 100℃ for 1h, cool to room temperature, filter, water wash, purify and dry to obtain yellow powder, then purify by 200 mesh silica gel column chromatography (dichloromethane / methanol 50:1) to obtain pure phenolphthalein tetraaldehyde In-CHO-2; take 2mmol of In-CHO-2, 4 equivalents (8mmol) of aminoguanidine hydrochloride, dissolve in 100mL of acetonitrile, reflux for 12h, cool to room temperature, filter and wash with acetonitrile, vacuum dry at 60℃ to obtain orange yellow powder type I probe 1 (78%). The synthesis route is shown in Figure 1 , the structure is determined by Figure 2 nuclear magnetic hydrogen spectrum, Figure 3 1 H- 1 H-noesy NMR spectrum, Figure 4 nuclear magnetic carbon spectrum, Figure 5 ESI-MS mass spectrum. 1 H NMR (400 MHz, DMSO- d 6) δ (ppm): 12.35 (s, 4H), 10.09(s, 2H), 8.48 (s, 4H), 8.32 (d, J = 7.8 Hz, 1H), 7.94 (s, 1H), 7.93 – 7.84(m, 12H), 7.82 (s, 4H), 7.70 (t, J = 7.5 Hz, 2H). 13 C NMR (400 MHz, DMSO- d6) δ (ppm): 168.69, 155.18, 154.01, 150.81, 145.23, 135.17, 132.96, 130.2, 128.67, 125.82, 125.14, 124.55, 129.72, 89.89. FT-IR (cm -1 ) v (ppm): 3151 (v), 1756 (m), 1676 (vs), 1624 (vs), 1459 (m), 1351 (w), 1249 (w), 1153 (w), 1111 (w), 947 (w), 757 (w), 699 (w), 614 (w). HRMS (ESI +ve) m / z: 685.4 ([M+CH3OH+H] + ), C 28 H 30 N 16 O4 calculated 655.26.

[0053] The probe 1 can be easily dissolved in pure water as a yellow transparent solution, and can quickly fade to colorless (F Figure 6 ) to the acetate, sulfate and fluoride ions in water, while other anions do not change color, these ions include Cl - , Br - , I - , PF6 - , CO3 2- , ClO4 - , NO3 - , PhCO2 - (benzene carboxylate) and CN - . Further, the UV-vis absorption spectra of the blank probe 1 and the probe 1 after adding 10 equivalents of anions are shown in Figure 7 , which shows that only when AcO - , SO4 2- and F - are added, the strong absorption peak of probe 1 at 425 nm is significantly weakened, while other anions have no obvious change. Similarly, the absorption peak at 350 nm is only significantly enhanced when AcO - , SO4 2- and F - are added, further proving the high responsiveness of probe 1 to the three target anions. The UV-vis titration curves of probe 1 to the three anions are shown in Figures 8-10The results showed that with the continuous addition of anions, the UV-Vis absorption curve of probe 1 gradually weakened, especially the absorption peak at 425 nm, which showed a more significant decrease. The AcO2 obtained by fitting the above titration data (1:2 model) using the Bindfit program... - SO4 2- and F - The binding constant logβ is 7.13 (SO4). 2- >3.38 (AcO) - )≈3.24(F - M -2 .

[0054] Example 2: Preparation method of colorimetric probe 2 (type II probe) of the present invention and its AcO - and SO4 2- The identification.

[0055] 2 mmol of probe 1 from Example 1 was dissolved in 80 mL of ethanol, and 20 mmol of NaBH4 reducing agent was dissolved in ethanol. These solutions were slowly added in batches to the above solution. After reflux for 48 h, the mixture was cooled to room temperature, and the filtrate was desolvated to obtain a green solid. This solid was dissolved in 100 mL of deionized water, and the pH of the solution was adjusted to 10 using 0.1 M hydrochloric acid. During pH adjustment, a large amount of green powder precipitated from the solution. After centrifugation of the heterogeneous solution, it was vacuum dried at 60 °C for 12 h to obtain probe 2 (35%), which is a green powder. The synthetic route is as follows: Figure 11 As shown, its structure consists of Figure 12 1H NMR spectrum Figure 13 1 H- 1 H-noesy spectrum Figure 14 Carbon NMR spectrum. 1 H NMR (400MHz, DMSO- d 6) δ 8.25 (d, J = 6.6 Hz, 4H), 8.20 (s, 1H), 8.04 (d, J = 7.8 Hz, 1H), 7.92 (d, J = 7.2 Hz, 2H), 7.85 (t, J = 7.2 Hz, 2H), 7.67 (t, J = 7.4 Hz, 2H), 7.51(s, 1H), 7.45 (d, J = 5.2 Hz, 4H), 7.29 (s, 2H), 7.24 – 7.09 (m, 2H), 6.69 –6.42 (m, 3H), 6.33 (s, 2H), 5.78 (s, 16H).13 C NMR (400 MHz, DMSO- d 6) δ (pm):179.59, 158.9, 134.68, 127.14, 121.28, 120.34, 78.09,77.77, 77.44. FT-IR (cm -1 ) Figure 15 (ppm): 3421 (vs), 1748 (w), 1623 (m), 1469 (s), 1346 (m), 1261 (w), 1132 (m), 1102 (s), 944 (m), 825 (m), 708 (w), 604 (w), 462 (w).

[0056] Probe 2 dissolves in pure water to form a yellow, transparent solution, and can rapidly decolorize acetate and sulfate ions in water until they are colorless. Figure 16 It does not change color for other anions, including Cl-. - ,Br - I - F-, PF6 - CO3 2- ClO4 - NO3 - PhCO2 - (Benzoyl carboxylate) and CN - Furthermore, the UV-vis absorption spectra of blank probe 2 and probe 2 after adding 10 equivalents are as follows: Figures 17-18 As shown, only AcO is displayed. - and SO4 2- When this anion is added, the strong absorption peak at 380 nm of probe 2 only significantly weakens, while the absorption peak does not change significantly when other anions are added. Similarly, the absorption peak at 268 nm only weakens when AcO is added. - SO4 2- and F - The effect only significantly weakened upon addition, further demonstrating the high responsiveness of probe 2 to the two target anions. UV-vis titration curves of probe 2 for the two anions ( Figure 19 The results showed that with the continuous addition of anions, the UV-Vis absorption curve of probe 2 gradually weakened, especially the absorption peak at 380 nm, which showed a more significant decrease. The AcO2 obtained by fitting the above titration data (1:2 model) using the Bindfit program... - and SO4 2- The binding constant logβ is 3.66 (SO4). 2- ~3.66 (AcO) - M-2 .

[0057] Example 3: Preparation of the colorimetric probe 3 (type II probe) of the present invention and its AcO - The identification.

[0058] 4 g of phenolphthalein, 10 equivalents of hexamethylenetetramine, and 80 mL of trifluoroacetic acid were weighed and mixed. The mixture was reacted at 100 °C for 4 h under an argon atmosphere. 3 M hydrochloric acid aqueous solution (300 mL) was added, and the mixture was hydrolyzed at 100 °C for 1 h. After cooling to room temperature, the mixture was filtered, washed with water, purified, and dried to obtain a yellow powder. The powder was then purified by silica gel column chromatography (dichloromethane / methanol 80:1) to obtain pure phenolphthalein dialdehyde In-CHO-1. 2 mmol of In-CHO-1 and 2 equivalents of aminoguanidine hydrochloride were weighed and dissolved in 80 mL of acetonitrile. The mixture was refluxed for 12 h, cooled to room temperature, filtered, washed with acetonitrile, and dried under vacuum at 60 °C to obtain an orange-yellow powder. Then, the above-mentioned orange-yellow powder (2 mmol) was dissolved in 50 mL of ethanol, and 10 equivalents of NaBH4 were slowly added in batches. The reaction was refluxed at 60 °C for 48 h, cooled to room temperature, and the organic solvent was removed by rotation. 50 mL of deionized water was added to dissolve the powder, and the pH of the solution was adjusted to 10 using 0.1 M hydrochloric acid. During the pH adjustment process, a large amount of green powder precipitated from the solution. After centrifugation of the heterogeneous solution, it was vacuum dried at 60 °C for 12 h to obtain probe 3 (50%), which was a blue powder. The synthetic route is as follows: Figure 20 As shown, its structure consists of Figure 21 1H NMR spectrum Figure 22 carbon spectrum, Figure 23 ESI-MS mass spectrometry was used to determine the result. 1 H NMR (400 MHz, DMSO- d 6 ) Figure 24 8.12 (s, 2H), 7.93 – 7.85 (m, 2H),7.82 (t, J = 6.9 Hz, 1H), 7.65 (t, J = 7.9 Hz, 1H), 7.27 (d, J = 2.4 Hz, 2H),7.04 (d, J = 8.6 Hz, 2H), 6.83 (d, J = 8.6 Hz, 2H), 5.70 (d, J = 35.3 Hz, 6H). 13 C NMR (400 MHz, DMSO- d 6 ) Figure 25169.48, 159.77, 157.48, 152.65, 146.71, 135.36,131.86, 130.16, 127.85, 127.69, 125.91, 125.00, 124.87, 120.70, 116.22. FTIR(KBr, cm -1 ) ν 3456(s), 3381(w), 3201(s), 1752(m), 1626(vs), 1548(s). ESI-MS(positive-ion): m / z [M+H2O+H] + calcd. for C 24 H 29 N8O5, 509.23; found, 509.168.

[0059] Probe 3 dissolves in pure water to form a blue, transparent solution, and can rapidly decolorize acetate ions in water to a colorless state. Figure 26 It does not change color for other anions, including Cl-. - ,Br - I - F-, PF6 - ClO4 - NO3 - SO4 2- PhCO2 - (Benzoyl carboxylate) HCOO - HPO3 2- and CN - Furthermore, the UV-vis absorption spectra of blank probe 3 and its addition of 10 equivalents are as follows: ​ , ​ As shown, only AcO is displayed. - When probe 3 is added, the strong absorption peak at 580 nm significantly weakens, while the absorption peak does not change significantly when other anions are added. Probe 3 affects AcO. - UV-vis titration curve of anions ( ​ The results showed that with the continuous addition of anions, the UV-Vis absorption curve of probe 3 gradually weakened, especially the absorption peak at 580 nm, which showed a more significant decrease. The AcO2 obtained by fitting the above titration data (1:2 model) using the Bindfit program... - The binding constant logβ is 6.52M. -2 .

[0060] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A water-soluble colorimetric anion probe based on hydrogen bonding, characterized in that, The colorimetric anion probe includes a type I probe and a type II probe. Both type I and type II probes are composed of two parts: an aminoguanidine and its derivatives, and a xatonne or triphenylmethane indicator molecule, as shown in formulas (1) and (2). Formula (1) Type I probe, Formula (2) Type II probe, In this context, R represents a sulfanilamide or triphenylmethane derivative, and the site where the aminoguanidine group is attached to R is adjacent to the phenolic hydroxyl group.

2. The hydrogen-bonded water-soluble colorimetric anion probe according to claim 1, characterized in that, R is selected from aldehyde derivatives of phenolphthalein, thymolphthalein, fluorescein, or phenol red.

3. A method for preparing the water-soluble colorimetric anion probe according to claim 1 or 2, characterized in that, Includes the following steps: S1. Reaction of xanthannaphthalene or triphenylmethane indicator molecules with hexamethylenetetramine in trifluoroacetic acid, followed by acidic hydrolysis to obtain aldehyde derivatives; S2. The aldehyde derivative obtained in step S1 is reacted with aminoguanidine hydrochloride under reflux in an organic solvent to obtain a type I probe; S3. Reduce the type I probe obtained in step S2 with sodium borohydride to obtain the type II probe.

4. The preparation method according to claim 3, characterized in that, In step S1, 2-4 g of xanthannaphthalene or triphenylmethane indicator molecules, 10-15 equivalents of hexamethylenetetramine, and 40-80 mL of trifluoroacetic acid are added. The mixture is reacted at 80-100 °C for 3-24 h under nitrogen protection. After the reaction, 100-300 mL of 3M hydrochloric acid aqueous solution is added, and the mixture is hydrolyzed at 100 °C for 1-2 h. The mixture is then cooled to room temperature, filtered, washed with water, and dried to obtain a yellow powder. The powder is then purified by silica gel column chromatography to obtain an aldehyde derivative.

5. The preparation method according to claim 3, characterized in that, In step S2, 2 mmol of the aldehyde derivative and 4 or 8 equivalents of aminoguanidine hydrochloride are refluxed in an organic solvent for 12 h, cooled to room temperature, filtered and washed with an organic solvent, and vacuum dried to obtain a type I probe; the organic solvent is acetonitrile or N,N-dimethylformamide.

6. The preparation method according to claim 3, characterized in that, In step S3, 2 mmol of type I probe was dissolved in 50-300 mL of ethanol, 10 equivalents of sodium borohydride were added, and the mixture was refluxed for 48 h. After the reaction, the pH was adjusted to 10 with 0.1 M hydrochloric acid. During the pH adjustment process, a large amount of solid powder precipitated from the solution. The precipitate was centrifuged and washed with deionized water, and then dried under vacuum to obtain type II probe.

7. The application of the water-soluble colorimetric anion probe according to claim 1 or 2 in the preparation of anion detection reagents.

8. The application according to claim 7, characterized in that, The anion is one or more of acetate ions, sulfate ions, or fluoride ions.

9. The application according to claim 7, characterized in that, The probe forms multiple hydrogen bonds with the anion through the NH group on the aminoguanidine group, and the binding stoichiometry between the probe and the anion is 1:2.

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