A two-photon two-state luminescent porphyrin fluorescent dye and a preparation method thereof

Abstract

The application relates to the technical field of functional porphyrin derivative preparation, and discloses a two-photon two-state light-emitting porphyrin fluorescent dye and a preparation method thereof.The preparation method comprises the following steps: dissolving salicylaldehyde porphyrin in a solvent to obtain solution A; dissolving aromatic amine in a solvent to obtain solution B; mixing and stirring the solution A and the solution B, and heating to 110-120 DEG C to reflux; performing vacuum distillation on the reaction liquid, and then performing recrystallization, and drying to obtain the two-photon two-state light-emitting porphyrin fluorescent dye.The porphyrin fluorescent dye disclosed by the application can be excited by 780 nm near-infrared light and emits red fluorescence of about 650 nm, and can emit fluorescence in both solution and solid state, and has two-photon and two-state light-emitting dual performances.The porphyrin fluorescent dye can effectively reduce light damage, reduce the interference of background fluorescence and improve the penetration depth while maintaining the continuity of the fluorescent signal, and has a good application prospect.The preparation method disclosed by the application has simple synthesis process, the product is easy to purify, and is suitable for industrial production.

Description

Technical Field

[0001] This application relates to the field of functionalized porphyrin derivative preparation technology, specifically to a two-photon two-state luminescent porphyrin fluorescent dye and its preparation method. Background Technology

[0002] Porphyrins are red-light dyes with excellent photothermal stability, high Stokes shift, and red light emission, making them widely applicable in photodynamic therapy, optoelectronic devices, fluorescence analysis, photoelectrocatalysis, and supramolecular chemistry. Therefore, the synthesis of porphyrins and their derivatives has attracted considerable attention from researchers.

[0003] However, in practical applications, most porphyrins currently suffer from two major problems that significantly limit their application. First, although porphyrins exhibit relatively long red light emission, their excitation wavelength is very short, around 420 nm, even shorter than the excitation wavelength of common green-emitting fluorescent dyes. In biomedical applications, short-wavelength excitation not only causes significant photodamage and background fluorescence interference but also has limited penetration depth. Second, there is the aggregation-induced quenching (ACQ) problem. Porphyrin fluorescence emission is limited to dilute solutions. When the porphyrin concentration is high or it becomes solid, the strong intermolecular π-π interactions cause a significant decrease or quenching of fluorescence. In applications that rely on fluorescence for analysis and diagnosis (such as fluorescence sensing and photodynamic therapy), changes in the fluorescence signal can introduce significant deviations, affecting accuracy.

[0004] Currently, researchers have successively discovered and designed various two-photon and two-state luminescent fluorescent dyes. Among them, two-photon fluorescent (TPF) dyes are dyes that generate short-wavelength emission through long-wavelength excitation, also known as anti-Stokes fluorescent dyes. Their excitation range is in the near-infrared region, and they have advantages such as low photodamage, low background fluorescence interference, and strong tissue penetration. On the other hand, two-state luminescent (DSE) dyes have little or no ACQ effect and can emit fluorescence in both solution and solid states. Their fluorescence emission is no longer limited by the state and can better maintain the continuity and stability of the fluorescence signal.

[0005] Based on this, this application develops new porphyrin dyes based on two-photon and two-state luminescence properties to improve the application performance of porphyrins. Summary of the Invention

[0006] This application provides a two-photon, two-state luminescent porphyrin fluorescent dye and its preparation method, aiming to solve the problems of large photodamage, large background fluorescence interference, and limited penetration depth caused by the short excitation wavelength of porphyrin fluorescent dyes in the prior art, as well as poor continuity and low accuracy of fluorescence signals caused by aggregation-induced quenching.

[0007] To achieve the above objectives, the present application adopts the following technical solution.

[0008] A first aspect of this application provides a two-photon, two-state luminescent porphyrin fluorescent dye having the chemical structure shown in formula (1):

[0009]

[0010] R contains at least one benzene ring.

[0011] In some implementation schemes, R is:

[0012]

[0013] A second aspect of this application provides a method for preparing the aforementioned two-photon, two-state luminescent porphyrin fluorescent dye, comprising:

[0014] Salicylaldehyde porphyrin was dissolved in a solvent to obtain solution A; an aromatic amine was dissolved in a solvent to obtain solution B; solutions A and B were mixed and stirred, and then heated to 110-120℃ and refluxed.

[0015] The reaction solution was distilled under reduced pressure, recrystallized, and dried to obtain a two-photon two-state luminescent porphyrin fluorescent dye.

[0016] In some embodiments, the salicylaldehyde porphyrin is 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin, which has the chemical structure shown in formula (2):

[0017]

[0018] In some embodiments, the 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin is prepared by the following method:

[0019] S1, Hydroxyporphyrin was prepared using p-hydroxybenzaldehyde, benzaldehyde and pyrrole;

[0020] S2, hydroxyporphyrin and hexamethylenetetramine are dissolved in trifluoroacetic acid and refluxed at 70°C for 24-36 h; wherein the molar ratio of hydroxyporphyrin to hexamethylenetetramine is 1:2;

[0021] S3, add hydrochloric acid to the reaction solution, and then add alkaline solution to adjust the pH to 7-8;

[0022] S4. Extract the reaction solution with dichloromethane to collect the organic phase. Dry the organic phase, filter it, and distill it under reduced pressure to obtain the crude product.

[0023] S5, the crude product was purified by chromatography to obtain a purple solid, namely salicylaldehyde porphyrin;

[0024] The chromatography process uses a silica gel column and the eluent is a mixture of petroleum ether and ethyl acetate in a volume ratio of 3:1.

[0025] In some embodiments, the preparation of hydroxyporphyrin using p-hydroxybenzaldehyde, benzaldehyde, and pyrrole specifically involves:

[0026] p-hydroxybenzaldehyde and benzaldehyde were added to propionic acid and heated to reflux. Then, pyrrole was slowly added dropwise to the propionic acid solution and refluxed at 130-150℃ for 1-2 hours. The reaction solution was distilled under reduced pressure to remove propionic acid, and anhydrous ethanol was added and stirred evenly. After standing at -20℃, the solution was filtered. The filter cake was washed and dried to obtain the crude product.

[0027] The crude product was purified by silica gel column chromatography to obtain a purple solid, namely hydroxyporphyrin.

[0028] In some embodiments, the aromatic amine is aniline, p-hydroxyaniline, p-methylaniline, p-nitroaniline, 4-N,N-diphenylaniline, or 5-(4-aminophenyl)-10,15,20-triphenylporphyrin;

[0029] In some embodiments, the solvent is a mixed solution of toluene and n-butanol, wherein the volume ratio of toluene to n-butanol is 1:(1-2).

[0030] In some embodiments, the molar ratio of the salicylaldehyde porphyrin to the aromatic amine is 1:(2-3).

[0031] In some embodiments, the solvent used for recrystallization is methanol, ethanol, n-propanol, or n-butanol.

[0032] Compared with the prior art, the beneficial effects of this application are as follows:

[0033] The porphyrin fluorescent dyes described in this application can all be excited by near-infrared light at 780 nm and emit red fluorescence at around 650 nm. They can emit fluorescence in both solution and solid states, exhibiting both two-photon and two-state luminescence properties. While maintaining the continuity of the fluorescence signal, they can effectively reduce optical damage, decrease interference from background fluorescence, and increase penetration depth, demonstrating promising application prospects.

[0034] The preparation method of this application has a simple synthesis process and the product is easy to purify, making it suitable for industrial production. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1High-resolution mass spectrometry [M+H] for porphyrin fluorescent dye 1 + picture;

[0037] Figure 2 High-resolution mass spectrometry [M+H] for porphyrin fluorescent dye 2 + picture;

[0038] Figure 3 High-resolution mass spectrometry [MH] for porphyrin fluorescent dye 3 - picture;

[0039] Figure 4 The image shows the 1H NMR spectrum of porphyrin fluorescent dye 1 (solvent: CD2Cl2);

[0040] Figure 5 The image shows the 1H NMR spectrum of porphyrin fluorescent dye 2 (solvent: CD2Cl2).

[0041] Figure 6 The image shows the 1H NMR spectrum of porphyrin fluorescent dye 3 (solvent: CD2Cl2).

[0042] Figure 7 SEM image of porphyrin fluorescent dye 1;

[0043] Figure 8 SEM image of porphyrin fluorescent dye 2;

[0044] Figure 9 SEM image of porphyrin fluorescent dye 3;

[0045] Figure 10 The solution and solid fluorescence spectra of porphyrin fluorescent dye 1 are shown (E). x =420nm);

[0046] Figure 11 The solution and solid fluorescence spectra of porphyrin fluorescent dye 2 are shown (E). x =420nm);

[0047] Figure 12 The solution and solid fluorescence spectra of porphyrin fluorescent dye 3 are shown (E). x =420nm);

[0048] Figure 13 Two-photon fluorescence spectrum of porphyrin fluorescent dye 1 (E x =780nm);

[0049] Figure 14 The two-photon fluorescence spectrum (E) of porphyrin fluorescent dye 2 x =780nm);

[0050] Figure 15Two-photon fluorescence spectrum of porphyrin fluorescent dye 3 (E x =780nm). Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0052] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0053] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0054] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0055] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0056] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0057] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0058] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0059] In a first aspect, this application provides a two-photon, two-state luminescent porphyrin fluorescent dye having the chemical structure shown in formula (1):

[0060]

[0061] R contains at least one benzene ring.

[0062] In this application, the preferred value of R is:

[0063]

[0064] The two-photon, two-state luminescent porphyrin fluorescent dyes of this application can be excited by near-infrared light at 780 nm and emit red fluorescence with a wavelength of about 650 nm. They can emit fluorescence in both solution and solid state, and have dual properties of two-photon and two-state luminescence.

[0065] The two-photon, two-state luminescent porphyrin fluorescent dye of this application can emit fluorescence in both solid and liquid states. While maintaining the continuity of the fluorescence signal, it can also effectively reduce light damage, reduce interference from background fluorescence, and improve the penetration depth, showing great application potential.

[0066] Secondly, this application provides a method for preparing the above-mentioned two-photon two-state luminescent porphyrin fluorescent dye, comprising:

[0067] Salicylaldehyde porphyrin was dissolved in a solvent to obtain solution A; an aromatic amine was dissolved in a solvent to obtain solution B; solutions A and B were mixed and stirred, and then heated to 110-120℃ and refluxed.

[0068] The reaction solution was distilled under reduced pressure, recrystallized, and dried to obtain a two-photon two-state luminescent porphyrin fluorescent dye.

[0069] In this application, the salicylaldehyde porphyrin is 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin, which has the chemical structure shown in formula (2):

[0070]

[0071] 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin is prepared by the following method:

[0072] S1, Hydroxyporphyrin was prepared using p-hydroxybenzaldehyde, benzaldehyde and pyrrole;

[0073] Specifically, p-hydroxybenzaldehyde and benzaldehyde are added to propionic acid and heated to reflux. Then, pyrrole is slowly added dropwise to the propionic acid solution and refluxed at 130-150℃ for 1-2 hours. The reaction solution is then distilled under reduced pressure to remove propionic acid. Anhydrous ethanol is added and stirred until homogeneous. After standing at -20℃, the solution is filtered. The filter cake is washed and dried to obtain the crude product.

[0074] The crude product was purified by silica gel column chromatography to obtain a purple solid, namely hydroxyporphyrin. The eluent used for the chromatography purification was a mixture of dichloromethane and petroleum ether in a volume ratio of 2:1.

[0075] The synthetic reaction formula for the hydroxyporphyrin is as follows:

[0076]

[0077] S2, Hydroxyporphyrin and hexamethylenetetramine are dissolved in trifluoroacetic acid and refluxed at 70°C for 24-36 h;

[0078] In this process, hydroxyporphyrin and hexamethylenetetramine undergo a formylation reaction in trifluoroacetic acid, wherein the molar ratio of hydroxyporphyrin to hexamethylenetetramine is preferably 1:2, and the molar volume ratio of hydroxyporphyrin to trifluoroacetic acid is 0.1-0.2 mmol / mL.

[0079] S3, add hydrochloric acid to the reaction solution, and then add alkaline solution to adjust the pH to 7-8;

[0080] Hydrochloric acid is used to decompose residual hexamethylenetetramine. The concentration of hydrochloric acid is 1 mol / L, and the volume of hydrochloric acid is 40 times that of trifluoroacetic acid. Alkaline solution is used to neutralize hydrochloric acid. The alkaline solution is a 1 mol / L sodium hydroxide or potassium hydroxide solution.

[0081] S4. Extract the reaction solution with dichloromethane to collect the organic phase. Dry the organic phase, filter it, and distill it under reduced pressure to obtain the crude product.

[0082] The drying process uses anhydrous Na2SO4.

[0083] S5, the crude product was purified by chromatography to obtain a purple solid, namely salicylaldehyde porphyrin;

[0084] The chromatography uses a silica gel column, and the eluent used in the chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of 3:1.

[0085] The synthetic reaction formula for the 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin is as follows:

[0086]

[0087] In this application, a two-photon two-state luminescent porphyrin fluorescent dye is synthesized by reacting a porphyrin containing a salicylaldehyde structure with an aromatic amine in a solvent via a Schiff base reaction.

[0088] The aromatic amine is aniline, p-hydroxyaniline, p-methylaniline, p-nitroaniline, 4-N,N-diphenylaniline, or 5-(4-aminophenyl)-10,15,20-triphenylporphyrin. In this application, the aromatic amine is preferably aniline, 4-N,N-diphenylaniline, or 5-(4-aminophenyl)-10,15,20-triphenylporphyrin. The solvent is a mixed solution of toluene and n-butanol. Specifically, a mixed solution with a volume ratio of toluene to n-butanol of 1:(1-2) is preferred, such as a volume ratio of toluene to n-butanol of 1:1, 1:1.5, 1:2, or any ratio within this range.

[0089] In this application, the preferred molar ratio of salicylaldehyde porphyrin to aromatic amine is 1:(2-3), such as 1:2, 1:2.5, 1:3, or any ratio within this range. Within this range, two-photon two-state luminescent porphyrin fluorescent dyes can be successfully synthesized.

[0090] Specifically, in this application, when aniline is selected as the aromatic amine, the synthesis reaction formula is as follows:

[0091]

[0092] When 4-N,N-diphenylaniline is selected as the aromatic amine, the synthesis reaction formula is as follows:

[0093]

[0094] When the aromatic amine is 5-(4-aminophenyl)-10,15,20-triphenylporphyrin, the synthetic reaction formula is as follows:

[0095]

[0096] In this application, after the reaction of salicylaldehyde porphyrin with aromatic amine is completed, the reaction solution is distilled under reduced pressure to remove the mixed solvent. Then, methanol, ethanol, n-propanol or n-butanol are added to the reaction solution for recrystallization. The crystals are then dried under vacuum to obtain a purple two-photon two-state luminescent porphyrin fluorescent dye.

[0097] The present application will be further illustrated by the following examples.

[0098] Preparation of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin in the Example

[0099] 32.7 mmol of p-hydroxybenzaldehyde and 88.0 mmol of benzaldehyde were added to 250 mL of propionic acid and heated to reflux. Then, 129.6 mmol of pyrrole was slowly added dropwise to the propionic acid solution. The mixture was refluxed at 140 °C for 1 h, and then heating was stopped. After the reaction solution cooled, two-thirds of the volume of propionic acid was distilled off under reduced pressure. Then, 100 mL of anhydrous ethanol was added and stirred until homogeneous. The mixture was placed in a refrigerator at -20 °C for 12 h, and then filtered to obtain a purple filter cake. The filter cake was repeatedly washed with anhydrous ethanol and dried in a vacuum drying oven to obtain a solid crude product. The crude product was purified by silica gel column chromatography using dichloromethane / petroleum ether (2:1, v / v) as the eluent. After vacuum drying, a pure purple solid, namely hydroxyporphyrin TPP-OH, was obtained.

[0100] 0.79 mmol of hydroxyporphyrin TPP-OH and 1.58 mmol of hexamethylenetetramine were dissolved in 5 mL of trifluoroacetic acid and refluxed at 70 °C for 36 h. After the reaction was completed, 200 mL of 1 mol / L hydrochloric acid solution was added to the reaction solution, and the mixture was stirred at room temperature for 2 h. The pH was then adjusted to 7-8 with 1 mol / L NaOH solution. The reaction solution was extracted with dichloromethane, washed with distilled water, and the resulting organic layer was dried over anhydrous Na2SO4, filtered, and the solvent was removed under reduced pressure to obtain the crude product.

[0101] The crude product was purified by silica gel column chromatography, using a mixture of petroleum ether and ethyl acetate in a volume ratio of 3:1 as the eluent to obtain a purple solid salicylaldehyde porphyrin, namely 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin.

[0102] Example 1: Preparation of a two-photon, two-state luminescent porphyrin fluorescent dye using aniline

[0103] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.3 mmol of aniline were dissolved separately in a 1:1 volume ratio of toluene and n-butanol. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 12 hours with stirring. After the reaction was complete, the mixed solvent was removed under reduced pressure, and the mixture was recrystallized from methanol and dried under vacuum to obtain a purple porphyrin fluorescent dye 1 in 74.6% yield. The chemical formula of porphyrin fluorescent dye 1 is:

[0104]

[0105] The porphyrin fluorescent dye 1 was characterized by NMR and mass spectrometry, and the results are as follows:

[0106] 1 H NMR (400MHz, CD2Cl2) δ13.66(s,1H),8.96(s,1H),8.89(d,J=8.4Hz,8H),8.24(d,J=5.8Hz ,8H),7.78(d,J=6.8Hz,9H),7.48–7.39(m,6H),-2.78(s,2H).HR-MS(m / z):734.2911(M+H + (calcd 734.2920).

[0107] Example 2: Preparation of a two-photon, two-state luminescent porphyrin fluorescent dye using aniline

[0108] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.45 mmol of aniline were dissolved separately in a mixed solvent of toluene and n-butanol in a volume ratio of 1:2. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 24 hours with stirring. After the reaction was complete, the mixed solvent was removed by vacuum distillation, followed by recrystallization with ethanol and drying under vacuum to obtain a purple porphyrin fluorescent dye with a yield of 74.6%.

[0109] The porphyrin fluorescent dye was characterized by NMR and mass spectrometry, and the results are as follows:

[0110] 1 H NMR (400MHz, CD2Cl2) δ13.66(s,1H),8.96(s,1H),8.89(d,J=8.4Hz,8H),8.24(d,J=5.8Hz ,8H),7.78(d,J=6.8Hz,9H),7.48–7.39(m,6H),-2.78(s,2H).HR-MS(m / z):734.2911(M+H + (calcd 734.2920).

[0111] Example 3 uses 4-N,N-diphenylaniline to prepare a two-photon two-state luminescent porphyrin fluorescent dye.

[0112] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.3 mmol of 4-N,N-diphenylaniline were dissolved in a 1:1 mixture of toluene and n-butanol. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 12 hours with stirring. After the reaction was complete, the mixed solvent was removed under reduced pressure, and the mixture was recrystallized from n-propanol and dried under vacuum to obtain a purple porphyrin fluorescent dye 2 in 69.8% yield. The chemical formula of porphyrin fluorescent dye 2 is:

[0113]

[0114] The porphyrin fluorescent dye 2 was characterized by NMR and mass spectrometry, and the results are as follows:

[0115] 1 H NMR (400MHz, CD2Cl2) δ13.80(s,1H),8.96(s,2H),8.91–8.85(m,8H),8.23(dd,J=6.1,1.9Hz,8H),7.78(d,J=7.0Hz,9H),7.40(d,J=8.3Hz ,1H),7.33(s,2H),7.30–7.25(m,4H),7.13–7.11(m,3H),7.10–7.10(m,2H),7.07–7.02(m,2H),-2.79(s,2H).HR-MS(m / z):901.3649(M+H) + (calcd901.3655).

[0116] Example 4 uses 4-N,N-diphenylaniline to prepare a two-photon, two-state luminescent porphyrin fluorescent dye.

[0117] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.45 mmol of 4-N,N-diphenylaniline were dissolved in a mixed solvent of toluene and n-butanol in a volume ratio of 1:2. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 24 hours with stirring. After the reaction was complete, the mixed solvent was removed by vacuum distillation, followed by recrystallization with n-butanol and drying under vacuum to obtain a purple porphyrin fluorescent dye with a yield of 69.8%.

[0118] The porphyrin fluorescent dyes were characterized by NMR and mass spectrometry, and the results are as follows:

[0119] 1H NMR (400MHz, CD2Cl2) δ13.80(s,1H),8.96(s,2H),8.91–8.85(m,8H),8.23(dd,J=6.1,1.9Hz,8H),7.78(d,J=7.0Hz,9H),7.40(d,J=8.3Hz ,1H),7.33(s,2H),7.30–7.25(m,4H),7.13–7.11(m,3H),7.10–7.10(m,2H),7.07–7.02(m,2H),-2.79(s,2H).HR-MS(m / z):901.3649(M+H) + (calcd901.3655).

[0120] Example 5 uses 5-(4-aminophenyl)-10,15,20-triphenylporphyrin to prepare a two-photon two-state luminescent porphyrin fluorescent dye.

[0121] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.3 mmol of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin were dissolved in a 1:1 mixture of toluene and n-butanol. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 12 hours with stirring. After the reaction was complete, the mixed solvent was removed under reduced pressure, and the mixture was recrystallized from ethanol and dried under vacuum to obtain a purple porphyrin fluorescent dye 3, with a yield of 73.7%. The chemical formula of porphyrin fluorescent dye 3 is:

[0122]

[0123] The porphyrin fluorescent dye 3 was characterized by NMR and mass spectrometry, and the results are as follows:

[0124] 1 H NMR (400MHz, CD2Cl2) δ13.85(s,1H),9.04(s,1H),8.91(d,J=24.8Hz,16H),8.43(d,J=9.7Hz,2H),8.32(d ,J=9.1Hz,2H),8.23(d,J=4.5Hz,12H),7.79(s,21H),-2.79(d,J=18.7Hz,4H).HR-MS(m / z):1268.4766(MH + (calcd 1268.4843).

[0125] Example 6 uses 5-(4-aminophenyl)-10,15,20-triphenylporphyrin to prepare a two-photon two-state luminescent porphyrin fluorescent dye.

[0126] 0.15 mmol of 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin and 0.45 mmol of 5-(4-aminophenyl)-10,15,20-triphenylporphyrin were dissolved in a mixed solvent of toluene and n-butanol in a volume ratio of 1:2. The two solutions were then added separately to round-bottom flasks and refluxed at 118 °C for 24 hours with stirring. After the reaction was complete, the mixed solvent was removed under reduced pressure, and the mixture was recrystallized from ethanol and dried under vacuum to obtain a purple porphyrin fluorescent dye in 73.7% yield.

[0127] The porphyrin fluorescent dyes were characterized by NMR and mass spectrometry, and the results are as follows:

[0128] 1 H NMR (400MHz, CD2Cl2) δ13.85(s,1H),9.04(s,1H),8.91(d,J=24.8Hz,16H),8.43(d,J=9.7Hz,2H),8.32(d ,J=9.1Hz,2H),8.23(d,J=4.5Hz,12H),7.79(s,21H),-2.79(d,J=18.7Hz,4H).HR-MS(m / z):1268.4766(MH + (calcd 1268.4843).

[0129] Mass spectrometry analysis was performed on porphyrin fluorescent dye 1 prepared in Example 1, porphyrin fluorescent dye 2 prepared in Example 3, and porphyrin fluorescent dye 3 prepared in Example 5. Figure 1 , Figure 2 and Figure 3 The images show the spectra of porphyrin fluorescent dye 1, porphyrin fluorescent dye 2, and porphyrin fluorescent dye 3, respectively. From... Figures 1-3 It can be seen that the target porphyrin fluorescent dye was successfully synthesized in Examples 1, 3 and 5.

[0130] The proton NMR spectra of porphyrin fluorescent dyes 1, 2, and 3 were analyzed. Figure 4 , Figure 5 and Figure 6 The figures show the 1H NMR spectra of porphyrin fluorescent dyes 1, 2, and 3, respectively. Figure 4 , Figure 5 and Figure 6 It can be seen that the target porphyrin fluorescent dye was successfully synthesized in Examples 1, 3 and 5.

[0131] SEM tests were performed on porphyrin fluorescent dye 1, porphyrin fluorescent dye 2, and porphyrin fluorescent dye 3, respectively. Figure 7 , Figure 8 and Figure 9The images show SEM images of porphyrin fluorescent dye 1, porphyrin fluorescent dye 2, and porphyrin fluorescent dye 3, respectively. Figure 7 It can be seen that porphyrin fluorescent dye 1 has a strip-like parallel stacked morphology; from Figure 8 It can be seen that porphyrin fluorescent dye 2 has a fine, irregularly stacked morphology; from Figure 9 It can be seen that porphyrin fluorescent dye 3 exhibits a plate-like stacked morphology. These three morphologies are completely different from the π-π close-packing of typical ACQ-effect porphyrins such as tetraphenylporphyrin, which allows porphyrin fluorescent dyes 1-3 to largely avoid the ACQ effect caused by π-π interactions and produce obvious solid-state fluorescence.

[0132] Porphyrin fluorescent dye 1, porphyrin fluorescent dye 2, and porphyrin fluorescent dye 3 were subjected to solution and solid fluorescence spectra tests, respectively. The test parameters were: Ex = 420 nm, slit width 5-5 nm, and scanning range 600-800 nm. Figure 10 , Figure 11 and Figure 12 The images show the solution and solid fluorescence spectra of porphyrin fluorescent dyes 1, 2, and 3, respectively. Figure 10 , Figure 11 and Figure 12 It can be seen that porphyrin fluorescent dye 1, porphyrin fluorescent dye 2 and porphyrin fluorescent dye 3 all have strong fluorescence emission in solution, with a maximum emission wavelength of about 655 nm; at the same time, the three porphyrin fluorescent dyes also have strong fluorescence emission in the solid state, and the fluorescence spectrum of the solid state shows a significant red shift compared to the fluorescence spectrum of the solution, with a maximum emission wavelength of about 725 nm, which proves that the three dyes have obvious DSE performance.

[0133] Two-photon fluorescence spectra of porphyrin fluorescent dye 1, porphyrin fluorescent dye 2, and porphyrin fluorescent dye 3 were performed. The test parameters were: 780nm, 920nm, and 1030nm femtosecond lasers, Ex = 780nm, slit width: 1Au, and scanning wavelength range: 600-750nm. Figure 13 , Figure 14 and Figure 15 The images show the two-photon fluorescence spectra of porphyrin fluorescent dyes 1, 2, and 3, respectively. Figure 13 , Figure 14 and Figure 15 It is known that all three porphyrin fluorescent dyes have strong two-photon fluorescence emission, and their emission wavelength is the same as that of single-photon (Ex = 420 nm) emission spectrum. The difference is that the two-photon excitation wavelength is 780 nm, which makes the excitation and emission of porphyrin in the near-infrared region, and its application performance is greatly improved.

[0134] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A two-photon, two-state luminescent porphyrin fluorescent dye, characterized in that, It has the chemical structure shown in formula (1): (1) Where R is: , or .

2. The method for preparing the two-photon, two-state luminescent porphyrin fluorescent dye according to claim 1, characterized in that, include: Salicylic aldehyde porphyrin was dissolved in a solvent to obtain solution A; an aromatic amine was dissolved in a solvent to obtain solution B. Mix and stir solutions A and B, then heat to 110-120℃ and reflux. The reaction solution was distilled under reduced pressure, recrystallized, and dried to obtain a two-photon two-state luminescent porphyrin fluorescent dye. The salicylaldehyde porphyrin is 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin, which has the chemical structure shown in formula (2): (2)。 3. The preparation method according to claim 2, characterized in that, The 5-(4-hydroxy-3-formylphenyl)-10,15,20-triphenylporphyrin was prepared by the following method: S1, Hydroxyporphyrin was prepared using p-hydroxybenzaldehyde, benzaldehyde and pyrrole; S2, hydroxyporphyrin and hexamethylenetetramine are dissolved in trifluoroacetic acid and refluxed at 70°C for 24-36 h; wherein the molar ratio of hydroxyporphyrin to hexamethylenetetramine is 1:2; S3, add hydrochloric acid to the reaction solution, and then add alkaline solution to adjust the pH to 7-8; S4. Extract the reaction solution with dichloromethane to collect the organic phase. Dry the organic phase, filter it, and distill it under reduced pressure to obtain the crude product. S5, the crude product was purified by chromatography to obtain a purple solid, namely salicylaldehyde porphyrin; The chromatography process uses a silica gel column and the eluent is a mixture of petroleum ether and ethyl acetate in a volume ratio of 3:

1.

4. The preparation method according to claim 3, characterized in that, The preparation of hydroxyporphyrin using p-hydroxybenzaldehyde, benzaldehyde, and pyrrole specifically involves: p-hydroxybenzaldehyde and benzaldehyde were added to propionic acid and heated to reflux. Pyrrole was then slowly added dropwise to the propionic acid solution and refluxed at 130-150℃ for 1-2 hours. The reaction solution was then distilled under reduced pressure to remove propionic acid. Anhydrous ethanol was added and stirred until homogeneous. After standing at -20℃, the solution was filtered. The filter cake was washed and dried to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain a purple solid, namely hydroxyporphyrin.

5. The preparation method according to claim 2, characterized in that, The solvent is a mixed solution of toluene and n-butanol, wherein the volume ratio of toluene to n-butanol is 1:(1-2).

6. The preparation method according to claim 2, characterized in that, The molar ratio of the salicylaldehyde porphyrin to the aromatic amine is 1:(2-3).

7. The preparation method according to claim 2, characterized in that, The solvent used for recrystallization is methanol, ethanol, n-propanol, or n-butanol.

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