阅读说明：本技术 一种星型bodipy近红外荧光染料及其制备方法 (Star BODIPY near-infrared fluorescent dye and preparation method thereof ) 是由 徐海军 卫婷 宗轩莱 蔡正春 于 2021-07-28 设计创作，主要内容包括：本发明涉及一种星型BODIPY近红外荧光染料及其制备方法,采用BODIPY衍生物与4-甲酰基三苯胺在对甲苯磺酸和哌啶催化作用下发生Knoevenagel缩合反应合成。该制备方法反应步骤简单、反应条件温和。该荧光染料具有高的摩尔消光系数、良好的溶解性和光稳定性等优异的光物理性能,其最强电子吸收光谱和荧光发射光谱均在690nm以上,是性能非常好的一类近红外荧光染料,在近红外生物荧光成像、近红外荧光传感器、太阳能电池等领域具有良好的应用前景。(The invention relates to a star-shaped BODIPY near-infrared fluorescent dye and a preparation method thereof, which are synthesized by carrying out Knoevenagel condensation reaction on a BODIPY derivative and 4-formyltriphenylamine under the catalytic action of p-toluenesulfonic acid and piperidine. The preparation method has simple reaction steps and mild reaction conditions. The fluorescent dye has excellent photophysical properties such as high molar extinction coefficient, good solubility and light stability, the strongest electron absorption spectrum and fluorescence emission spectrum of the fluorescent dye are both more than 690nm, the fluorescent dye is a near-infrared fluorescent dye with very good performance, and the fluorescent dye has good application prospects in the fields of near-infrared biological fluorescence imaging, near-infrared fluorescence sensors, solar cells and the like.)

1. The star BODIPY near infrared fluorescent dye is characterized in that the structural formula is shown as the formula (I):

2. the preparation method of the star BODIPY near infrared fluorescent dye as claimed in claim 1, which is characterized by comprising the following steps: under the anhydrous condition, adding 1, 3, 5, 7, 8-pentamethyl-boron dipyrrole and 4-diphenylaminobenzaldehyde into dry toluene according to the molar ratio of 1: 3.0-4.0, adding p-toluenesulfonic acid and piperidine, stirring, heating and refluxing for 8-10 hours, finishing the reaction, cooling to room temperature, diluting with dichloromethane, washing with water, separating, drying, distilling under reduced pressure to remove an organic solvent, separating and purifying residues through a silica gel chromatographic column, and obtaining the star-shaped BODIPY near-infrared fluorescent dye by using dichloromethane and petroleum ether as eluent.

3. The method for preparing the star BODIPY near-infrared fluorescent dye according to claim 2, wherein the volume ratio of the toluene to the piperidine is 20: 1.

4. The method for preparing the star BODIPY near-infrared fluorescent dye according to claim 2, wherein the molar ratio of 1, 3, 5, 7, 8-pentamethyl-BODIPY, p-toluenesulfonic acid and 4-diphenylaminobenzaldehyde is 1: 0.6: 3.0-4.0.

5. The star BODIPY near infrared fluorescent dye of claim 1, wherein the 3, 5 and 8 positions contain three 4-diphenylanilino styryl groups, and the maximum absorption wavelength is more than 690 nm.

Technical Field

The invention belongs to the field of fine organic synthesis and functional fluorescent dyes, and particularly relates to a star BODIPY near infrared fluorescent dye and a preparation method thereof.

Background

In recent decades, organic fluorescent dyes have made many breakthrough advances in materials, biology, medicine, solar energy utilization, etc., and have become an important research field in organic chemistry. Organic fluorescent dyes generally have the characteristics of stronger absorption, fluorescence quantum yield and the like, Boron-dipyrromethene (BODIPY for short) is widely concerned due to excellent performance, and BODIPY consists of a nitrogen-Boron six-membered heterocyclic ring in the middle and pyrrole five-membered rings on the left side and the right side and has good conjugate planarity. Two sides of the plane of the matrix are respectively provided with a fluorine atom which is directly connected with a boron atom to form a complete structural unit, and various groups can be introduced for modification according to different purposes so as to improve the performance of various aspects.

In recent years, research on BODIPY compounds tends to synthesize near-infrared fluorescent dyes with long wavelength, because near-infrared light is less interfered during propagation and has good substance permeability, especially in the near-infrared spectral region, absorption and fluorescence of biomolecules are minimal, deviation of organism scattered light and autofluorescence on detection results can be avoided, scattering interference is greatly reduced, and permeability to tissue cells is high. Therefore, near-infrared dyes have unparalleled advantages in the field of biological detection. Compared with the traditional fluorescent dye, such as fluorescein, rhodamine and the like, the BODIPY compound has the properties of higher molar absorption coefficient, fluorescence quantum yield, fluorescence life, insensitivity of a fluorescence signal to solvent polarity and pH, strong absorption in a visible light region, better photo-thermal stability and the like. Moreover, the BODIPY molecule has certain chemical activity and can regulate the structure and the performance. Particularly, methyl groups at 3, 5 and 8 positions of the BODIPY parent nucleus have certain chemical activity and can perform Knoevenagel condensation reaction with aromatic aldehyde to form a larger aromatic ring conjugated system, so that the electron absorption and emission wavelengths of the compounds are obviously red-shifted. Therefore, the BODIPY derivatives can be prepared by modifying the 3, 5 and 8 positions of the BODIPY-3 by using aryl aldehyde groups.

Most of the existing near-infrared BODIPY dyes have multiple synthesis steps, high difficulty and poor solubility, and limit the further application of the dyes in the fields of biology, environment, medicine and the like. Triphenylamine and derivatives thereof have good electron donating property, low ionization potential, good solubility, amorphous film forming property, strong fluorescence property and light stability, and excellent charge transmission capability, so that triphenylamine and derivatives thereof have wide application in the fields of organic electroluminescent diodes (OLEDs), organic solar cells, field effect transistors, two-photon fluorescent materials and the like. The 4-diphenylamine benzaldehyde has extremely high formyl activity and can generate a plurality of chemical reactions, so that the 4-diphenylamine benzaldehyde plays an important role in synthesizing the series of functional materials. Therefore, the star BODIPY near infrared fluorescent dye with novel structure, simple preparation method and excellent performance can be synthesized by reacting the BODIPY derivatives with methyl groups at the 3, 5 and 8 positions with 4-diphenylaminobenzaldehyde through Knoevenagel condensation reaction to form a conjugated double bond. However, no research reports such compounds.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the defects in the prior art, the invention aims to provide a star BODIPY near infrared fluorescent dye. The invention also aims to provide a preparation method of the star BODIPY near infrared fluorescent dye.

The technical scheme is as follows: in order to achieve the purpose of the invention, the invention adopts the technical scheme that:

the invention relates to a star BODIPY near infrared fluorescent dye and a preparation method thereof, which are characterized in that the structural formula is shown as the following formula (I):

a preparation method of a star BODIPY near-infrared fluorescent dye derivative comprises the following steps:

1) under the anhydrous condition, adding 1, 3, 5, 7, 8-pentamethyl-boron dipyrrole, 4-diphenylamine benzaldehyde and newly dried p-toluenesulfonic acid into a round bottom flask, preparing a Dean-Stark device, adding 20-30 mL of toluene for dissolving, adding 1-1.5 mL of piperidine as a catalyst, stirring and heating until reflux is carried out for 8-10 hours; wherein the molar ratio of the 1, 3, 5, 7, 8-pentamethyl-boron dipyrrole to the 4-diphenylamine benzaldehyde is 1: 3-4.

2) Cooling the reactant to room temperature, diluting with dichloromethane, washing with brine, separating, drying an organic layer with anhydrous sodium sulfate, distilling under reduced pressure to remove the organic solvent, separating and purifying the residue by silica gel column chromatography, wherein the eluent is dichloromethane and petroleum ether, and the star BODIPY near-infrared fluorescent dye derivative is obtained.

The specific chemical reaction formula is as follows:

in the step (1), the molar ratio of the 1, 3, 5, 7, 8-pentamethyl-boron dipyrrole to the 4-diphenylamine benzaldehyde is 1: 3-4.

In the step (1), the dosage of the added toluene and piperidine is 20-30 mL and 1-1.5 mL respectively.

In the step (1), the molar ratio of 1, 3, 5, 7, 8-pentamethyl-boron dipyrrole, p-toluenesulfonic acid and 4-diphenylamine benzaldehyde is 1: 0.6: 3.0-4.0. .

In the step (2), the eluent for silica gel column chromatography separation is dichloromethane and petroleum ether (V)₁∶V₂＝2∶3)。

The invention has the advantages of

Compared with the prior art, the star BODIPY near infrared fluorescent dye and the preparation method thereof have the advantages that: (1) the preparation method is simple and easy to implement, and 4-diphenylamino styryl is introduced into 3, 5 and 8 positions of the BODIPY derivative through one-step condensation reaction to form a D-A-D molecular structure; (2) the compound has good solubility in organic solvent, is insensitive to oxygen and humidity, has good environmental stability and wide absorption range, and can absorb in the range of 300-800 nm. (3) The fluorescent dye has a narrow near infrared absorption peak, a high molar absorption coefficient and good light stability, so that the fluorescent dye has good application prospects in the fields of solar cells, fluorescent labeling, biological imaging and the like.

Drawings

FIG. 1 is a high resolution mass spectrum of a star BODIPY near infrared fluorescent dye (I);

FIG. 2 is a diagram of the UV-VIS absorption spectrum of a star BODIPY near-IR fluorescent dye (I).

Detailed Description

The invention is further described below with reference to the specific drawings.

By using¹H-NMR, HRMS and UV-Vis spectra characterization and confirmation of star BODIPY near infrared fluorescenceThe structure of the dye. The detection instrument is as follows: bruker ARX600 nuclear magnetic resonance apparatus (TMS as internal standard, deuterated DMSO as solvent), ThermoElectRON CORPORATION high resolution mass spectrometry workstation, Shimadzu UV-3100 UV-visible spectrophotometer (scan range 200-900 nm).

Example 1

BODIPY derivative (50mg, 0.19mmol), 4-formyltriphenylamine (136mg, 0.5mmol) and freshly dried p-toluenesulfonic acid (43mg) were dissolved in 25mL of toluene and 1mL of piperidine in a round-bottomed flask equipped with a Dean-Stark apparatus, the mixture was heated under reflux for 8 hours, cooled to room temperature, diluted with dichloromethane, washed with brine, the organic layer was dried over anhydrous sodium sulfate, the organic solvent was evaporated under reduced pressure, and the residue was purified by column chromatography on silica gel using dichloromethane and petroleum ether (V) as eluent₁∶V₂2: 3) to give BODIPY near infrared fluorescent dye (14 mg).¹H NMR(600MHz，DMSO-d₆)δppm 7.47(t，J＝11.4Hz，6H)，7.00(s，2H)，6.96(d，J＝8.4Hz，6H)，7.13(dd，J＝9.6，4.8Hz，6H)，7.09(d，J＝7.8Hz，14H)，7.61(d，J＝8.40Hz，2H)，2.29(s，6H)，7.36(t，J＝7.8Hz，14H)。

UV-vis: 240nm, 311nm, 359nm, 438nm, 547nm, 695nm (FIG. 2).

Example 2

In a round-bottomed flask equipped with a Dean-Stark apparatus, BODIPY derivative (50mg, 0.19mmol), 4-formyltriphenylamine (163mg, 0.6mmol) and freshly dried p-toluenesulfonic acid (43mg) were dissolved in 25mL of toluene and 1mL of piperidine, the mixture was heated under reflux for 10 hours, cooled to room temperature, diluted with dichloromethane, washed with saturated brine, separated on a separatory funnel, the organic layer was dried over anhydrous sodium sulfate, the organic solvent was evaporated under reduced pressure, and the residue was separated and purified by silica gel column chromatography to give BODIPY near-infrared fluorescent dye (12 mg).

Example 3 ultraviolet-visible absorption Spectrum of Star-shaped BODIPY near Infrared fluorescent dye (I) in methylene chloride

Dissolving star BODIPY near infrared fluorescent dye (I) in dichloromethane respectively to obtain a solution with a concentration of 1 × 10^{- 5}The UV-VIS absorption spectrum of the solution is measured in mol/L.