A bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative and preparation method thereof

Abstract

The invention discloses a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative and a preparation method thereof, which is achieved by the following method: using 5,15-bis-bromo-long-chain alkoxyporphyrin derivatives and 6-alkynyl naphthalimide derivatives as raw materials, Sonogashira coupling reaction occurs under the catalysis of cuprous iodide and tetrakis(triphenylphosphine)palladium to obtain bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivatives. The preparation method has simple reaction steps, mild reaction conditions and high yield. The compound can undergo efficient fluorescence resonance energy transfer, with the strongest absorption wavelength at 466nm and the maximum fluorescence emission wavelength at 714nm, and has excellent photophysical properties such as large Stokes shift and good photothermal stability. The bis-naphthalimide alkynyl conjugated long-chain alkyl porphyrin derivative has broad application prospects in the fields of light absorption antennas, energy storage materials and biological photosynthesis simulation.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and fine chemical industry, and specifically relates to a bis-naphthalimide alkynyl conjugated long-chain alkoxy porphyrin derivative and a preparation method thereof. Background Art

[0002] With the in-depth utilization of resources by human beings, the in-depth utilization of the inexhaustible solar energy has attracted more and more attention from scientific researchers. Porphyrin derivatives are the core groups of energy transfer in photosynthesis. In the light absorption system, the conversion of light energy to usable energy of the organism must be completed through the energy transfer mechanism. A simple light absorption system must at least contain a photochemical system containing an energy donor-acceptor molecule (donor-acceptor), in which fluorescence resonance energy transfer plays a vital role. Therefore, the design of organic molecules with high energy transfer efficiency has received widespread attention from researchers.

[0003] Naphthalimide derivatives have strong light absorption ability, high fluorescence quantum yield and large Stokes shift, and their structure has certain modifiability. In addition, they have excellent biological activity. Therefore, their synthesis and application in fluorescent probes, two-photon absorption, organic electroluminescence, bioluminescence imaging, anti-tumor activity, etc. have attracted widespread attention.

[0004] As one of the important fluorescent emission materials that has been widely used and continuously introduced in recent years, porphyrin and its derivatives have a series of excellent properties such as large Stokes shift, high fluorescence quantum yield, large molar extinction coefficient, etc. At the same time, by modifying the central skeleton of their fluorophore accordingly, novel derivatives with different fluorescence properties can be obtained. These advantages have greatly expanded their applications. In addition, the preparation methods of porphyrin and its derivatives are diverse, and suitable receptors can be effectively screened out, which provides a prerequisite for the development of effective photoinduced energy transfer molecular systems. Based on the excellent photoelectric properties and good modifiability of porphyrin compounds and similar derivatives, the present invention synthesizes a bis-naphthalene diimide conjugated long-chain alkoxy porphyrin derivative in one step through the Sonogashira coupling reaction, avoiding the problems of many steps in the synthesis of conjugated porphyrin derivatives, expensive catalysts, and difficulty. In this molecular system, the porphyrin absorption spectrum and the naphthalimide substituent emission spectrum are highly overlapped, and naphthalimide can be used as an energy donor, and porphyrin, as an energy acceptor, undergoes fluorescence energy resonance transfer, which can efficiently transfer energy from the naphthalimide fluorophore to the porphyrin group. Because naphthalimide and the porphyrin core are directly coupled by an alkynyl group, the steric hindrance between molecules is effectively reduced, the degree of conjugation between molecules and the planarity of porphyrin molecules are significantly increased, and the spectrum red shift is effectively promoted, so that the compound has potential application prospects in light collection systems, organic light emitting diodes, energy storage materials, biological photosynthesis simulations, and photodynamic therapy. And further research on this class of compounds will help us to understand the collection process of natural light by organisms at a deeper level, understand the essence of photosynthesis, and contribute to the development of new artificial photosynthesis systems. Summary of the invention

[0005] Purpose of the invention: In view of the deficiencies in the prior art, the purpose of the present invention is to provide a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative and a preparation method thereof.

[0006] Technical solution: In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0007] The present invention discloses a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative and a preparation method thereof, wherein the bis-naphthalimide conjugated alkynyl long-chain alkoxyporphyrin derivative has a structural formula as shown in the following formula (III):

[0008]

[0009] A bis-naphthalimide alkynyl conjugated long-chain alkoxy porphyrin derivative and a preparation method thereof, the steps are as follows:

[0010] Under anhydrous and oxygen-free conditions, 5,5-dibromo long-chain alkoxyporphyrin derivative and 6-alkynylnaphthalimide derivative are added to a dry triethylamine and tetrahydrofuran mixed solution in a molar ratio of 1:2.0-3.0, and then cuprous iodide and tetrakis(triphenylphosphine)palladium are added, stirred and heated, the temperature is controlled at 70-80°C, and the reaction time is 5-10 hours. The reaction mixture is cooled to room temperature, extracted with dichloromethane, washed with water, separated, the organic layer is dried with anhydrous sodium sulfate, the organic solvent is removed by reduced pressure distillation, and the residue is separated by silica gel column chromatography, the eluent is dichloromethane-petroleum ether, and a green solid product, dinaphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) is obtained. The specific chemical reaction formula is as follows:

[0011]

[0012] In the above step (1), the molar ratio of the 5,15-dibromo long-chain alkylporphyrin derivative to the 6-alkynylnaphthalimide derivative is 1:2.0-3.0.

[0013] In the above step (1), the volume ratio of tetrahydrofuran and triethylamine added is 1:1.

[0014] In the above step (1), the catalyst is cuprous iodide and tetrakis(triphenylphosphine)palladium.

[0015] In the above step (2), the molar ratio of 5,15-dibromo long-chain alkoxyporphyrin, cuprous iodide and tetrakis(triphenylphosphine)palladium is 1:0.2-0.3:0.05-0.15.

[0016] Beneficial effects of the present invention

[0017] Compared with the prior art, the present invention provides a bis-naphthalimide alkynyl conjugated long-chain alkoxy porphyrin derivative and a preparation method thereof, which have the following advantages: (1) the preparation method is simple and easy, with fewer synthesis steps, simple reaction conditions and higher yield; (2) the compound has a highly efficient fluorescence resonance energy transfer effect, the strongest electronic absorption wavelength is red-shifted to 466 nm, the maximum absorption wavelength is red-shifted to 703 nm, and the maximum emission wavelength is 714 nm, entering the near-infrared region, and can be used as a near-infrared fluorescent dye, and has a large Stokes shift (246 nm); (3) a naphthalimide derivative with biological activity and photoelectric activity is introduced into the porphyrin matrix through alkynyl coupling to form an energy donor-acceptor molecular system, and has a highly efficient energy transfer efficiency under light excitation, so that the compound has good application prospects in the fields of light absorption antennas, energy storage materials and simulated biological photosynthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1The emission spectrum (excitation wavelength: 374 nm) of the 5,15-dibromo long-chain alkoxyporphyrin derivative (I) and the absorption spectrum of the 6-alkynylnaphthalimide derivative (II);

[0019] Figure 2 The UV-visible absorption spectra of 5,15-dibromo long-chain alkoxyporphyrin derivatives (I), 6-alkynyl naphthalimide derivatives (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivatives (III);

[0020] Figure 3 It is a fluorescence emission spectrum of 5,15-dibromo long-chain alkoxyporphyrin derivative (I), 6-alkynylnaphthalimide derivative (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III), with an excitation wavelength of 374 nm. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the specific drawings.

[0022] The structure of the bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative was characterized and confirmed by 1H-NMR and MADLI-TOF. The spectral properties were determined by UV-Vis spectrum and fluorescence emission spectrum; the instruments used for detection were: Bruker ARX 400 nuclear magnetic resonance instrument (deuterated chloroform as solvent), Bruker Autoflex II matrix-assisted laser desorption time-of-flight mass spectrometer, Shimadzu UV-3100 ultraviolet-visible spectrophotometer, American LS 55 fluorescence spectrophotometer (the slits were all 2.5 mm).

[0023] Example 1 Preparation of bis-naphthalene diimide alkynyl conjugated long-chain alkoxy porphyrin derivative (III)

[0024] Under argon protection, 5,15-bisbromo long-chain alkoxyporphyrin derivative (112.66 mg, 0.131 mmol), Pd(PPh3)4 (16 mg, 0.0138 mmol), CuI (6 mg, 0.0315 mmol) were dissolved in 10 mL tetrahydrofuran and 5 mL triethylamine, and 6-alkynylnaphthalene dicarboxylic acid imide derivative (63 mg, 0.262 mmol) dissolved in 5 ml tetrahydrofuran was slowly added dropwise to the reaction mixture. The mixture was slowly heated to 70°C and stirred for 10 hours. Cooled to room temperature, extracted with dichloromethane, washed with water, separated, dried over anhydrous sodium sulfate, and the organic solvent was evaporated under reduced pressure. The residue was separated and purified by silica gel column chromatography, and the eluent was dichloromethane-petroleum ether to obtain a green solid bis-naphthalene dicarboxylic acid imide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) (90 mg, 63%). 1H NMR (400MHz, CDCl3, ppm) δ-2.69--2.79(s, 2H), 9.84-9.56(m, 5H), 9.16-9.03(m, 6H), 7.63-7.44(m, 8H), 7.04-6. 92(m, 5H), 4.29-4.24(m, 12H), 2.02-1.92(m, 15H), 1.46-1.41(m, 13H), 1.23(m, 60H), 0.83(m, 18H); MADLI-TOF: C 116 H 145 N6O8 calculated for:1750.112[M+H + ]; found: 1750.068; UV / Vis(Toluene): λ max (ε×10 -3 )=466(131.7), 617(28.0), 703nm(20.1M -1 cm -1 )( Figure 2 ); Emission Wavelength (Toluene): 714nm ( Figure 3 );

[0025] Example 2 Preparation of bis-naphthalene diimide alkynyl conjugated long-chain alkoxy porphyrin derivative (III)

[0026] Similar to Example 1, the difference is that the 5,15-dibromo long-chain alkoxyporphyrin derivative and the 6-alkynylnaphthalimide derivative in this example are reacted at a molar ratio of 1:2.5; the reaction temperature is controlled at 80°C and the reaction time is 8 hours. Yield: 48%.

[0027] Example 3 Preparation of bis-naphthalene diimide alkynyl conjugated long-chain alkoxy porphyrin derivative (III)

[0028] Similar to Example 1, the difference is that in this example, the 5,15-dibromo long-chain alkoxyporphyrin derivative is reacted with the 6-alkynylnaphthalimide derivative and cuprous iodide in a molar ratio of 1:2:0.3; the reaction temperature is controlled at 60°C and the reaction time is 6 hours. Yield: 42%.

[0029] Example 4 Emission spectrum of 5,15-dibromo long-chain alkoxyporphyrin derivative (I) and absorption spectrum of 6-alkynylnaphthalimide derivative (II) ( Figure 1 ).

[0030] The concentration of 1.0×10 -5The method comprises the following steps: a toluene solution of 5,15-dibromo long-chain alkoxy derivative (I) and 6-alkynyl naphthalimide derivative (II) at 374 nm light source, and a UV-visible absorption spectrum of the 5,15-dibromo long-chain alkoxy porphyrin derivative (I) and a fluorescence emission spectrum of the 6-alkynyl naphthalimide derivative (II) at room temperature. The maximum absorption wavelength of the soret band of the 5,15-dibromo long-chain alkoxy porphyrin derivative (I) is 410 nm, and the maximum emission wavelength of the 6-alkynyl naphthalimide derivative (II) is 408 nm, indicating that the absorption spectrum of the 5,15-dibromo long-chain alkoxy porphyrin derivative (I) and the emission spectrum of the naphthalimide derivative (II) are highly overlapped, and the two are coupled by alkynyl groups, which can effectively reduce the distance between the two, and is conducive to the occurrence of fluorescence resonance energy transfer.

[0031] Example 5 UV-visible absorption spectra of 5,15-dibromo long-chain alkoxyporphyrin derivative (I), 6-alkynylnaphthalimide derivative (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) ( Figure 2 ).

[0032] The concentration of 1.0×10 -5 The UV-visible absorption spectra of 5,15-dibromo long-chain alkoxyporphyrin derivative (I), 6-alkynylnaphthalimide derivative (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) in toluene solution at 100 mol / L were measured respectively. The results are as follows: Figure 2 The absorption spectrum of the bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin is a superposition of the absorption spectra of 5,15-dibromo long-chain alkoxyporphyrin derivatives and 6-alkynyl naphthalimide derivatives, but the Soret band of the porphyrin characteristic absorption is red-shifted to 466nm, and the Q band absorption is red-shifted to 703nm, indicating that the bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) has great application potential in the field of near-infrared fluorescent dyes.

[0033] Example 6 Fluorescence emission spectra of 5,15-dibromo long-chain alkoxyporphyrin derivative (I), 6-alkynylnaphthalimide derivative (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) ( Figure 3 ).

[0034] Toluene solutions of 5,15-dibromo long-chain alkoxyporphyrin derivative (I), 6-alkynylnaphthalimide derivative (II) and bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) with different concentrations were prepared respectively so that the three solutions had the same absorbance at the excitation wavelength (382nm). Figure 3The fluorescence emission spectra of the three compounds in toluene solution with an excitation long wavelength of 382nm are shown. The results show that when the naphthalene imide group is excited at 382nm, the bis-naphthalene imide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) does not emit the characteristic fluorescence emission peak of the naphthalene imide group, but an efficient photoinduced energy transfer occurs. The characteristic fluorescence emission of the naphthalene imide at 408nm in the bis-naphthalene imide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) is completely quenched, and the energy absorbed by the naphthalene imide derivative is transferred to the porphyrin group through intramolecular fluorescence resonance energy transfer, and the characteristic fluorescence emission peak of the porphyrin is emitted at 714nm. And relative to the 5,15-bis-bromo long-chain alkoxyporphyrin derivative (I), the fluorescence intensity is significantly enhanced, indicating that the bis-naphthalene imide alkynyl conjugated long-chain alkoxyporphyrin derivative (III) has broad application prospects in the fields of light absorption antennas, energy storage materials, near-infrared fluorescent materials, etc.

Claims

1. A bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III), characterized in that: Its structural formula is shown in the following formula (III):

2. The method for preparing the bis-naphthalimide alkynyl conjugated long alkoxy chain porphyrin derivative (III) according to claim 1, characterized in that: The method is achieved by the following steps: under anhydrous and oxygen-free conditions, adding a 5,15-dibromo long-chain alkoxyporphyrin derivative and 6-alkynylnaphthalimide in a molar ratio of 1:2.0-3.0 to a dry triethylamine and tetrahydrofuran mixed solution, then adding cuprous iodide and tetrakis(triphenylphosphine)palladium, stirring and heating, controlling the temperature at 70-80°C, reacting for 5-10 hours, terminating the reaction, cooling to room temperature, extracting with dichloromethane, separating, drying with anhydrous sodium sulfate, removing the organic solvent, and performing chromatography separation and purification with a silica gel column to obtain a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative (III). The chemical reaction formula of the preparation process is as follows:

3. The method for preparing a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative according to claim 2, characterized in that: The volume ratio of tetrahydrofuran and triethylamine to the amount of 5,15-dibromo long-chain alkoxyporphyrin derivative is 50-100 mL: 25-50 mL: 1 mmol.

4. The method for preparing a bis-naphthalimide alkynyl conjugated long-chain alkoxyporphyrin derivative according to claim 2, characterized in that: The molar ratio of 5,15-dibromo long-chain alkoxyporphyrin derivative, cuprous iodide, tetrakis(triphenylphosphine)palladium and 6-alkynylnaphthalimide is 1:0.2-0.3:0.05-0.15:2.0-3.0.

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