CN102040617A - Organic boron difluoride complex and preparation method thereof - Google Patents

Abstract

The invention discloses an organic boron difluoride complex, which is a compound shown in structural formula I: in structural formula I, R ₁ and R ₂ are each independently OCH ₃ , H or Cl; R ₃ and R ₄ are independently H, NO ₂ , Br, CH ₃ or OCH ₃ ; this type of complex has stable chemical properties, strong thermal stability, high fluorescence quantum yield and large molar absorptivity, not only has strong solution fluorescence, but also has remarkable solid fluorescence. The invention also discloses a preparation method of the organic boron difluoride complex, which is obtained by reacting the ligand and boron trifluoride ether in an anhydrous organic solvent in the presence of an organic base at room temperature or under reflux; the method has mild reaction conditions, The reaction time is short, the product yield is high, and the separation and purification are quick and easy.

Description

Organic boron difluoride complex and preparation method thereof

technical field

The invention relates to the field of organic synthesis, in particular to an organic boron difluoride complex and a preparation method thereof.

Background technique

Organic boron difluoride complexes are important fluorescent materials. As far as the coordination forms of boron atoms are concerned, the most important ones are N,N-bidentate ligands represented by pyrromethene and β-enolones. The two types of O, O-bidentate ligands are represented, and the research on their performance and application has been quite in-depth and abundant (Chem.Rev., 2007, 107, 4891; Angew.Chem.Int.Ed., 2008, 47, 1184; New J.Chem., 2007, 31, 496; J.Phys.Org.Chem.1996, 9, 7; J.Am.Chem.Soc., 2007, 129, 8942; Tetrahedron, 2007, 63, 9354 ).

However, there are relatively few studies on organic boron difluoride complexes containing N, O-bidentate ligands, which are isosteres of the above two, and there are even fewer reports on species with luminescent properties. From the preliminary relationship between the structure and luminescent properties, it can be known that the non-rotating σ bond of the N tooth is a necessary structural condition for the complex to emit light. Based on this, two types of β-enolimines are disclosed in Chinese invention patent ZL 200710070713.5 The boron difluoride complexes of N, O-bidentate ligands, these two types of complexes show strong green fluorescence in organic solution. The only few examples in the literature about the structure of the luminescent N, O-bidentate ligand organic boron difluoride complex also possess the element of N-dentate non-rotational σ bond (Org.Lett., 2008, 10, 633 ; Org. Lett., 2008, 10, 4437; Inorg. Chem., 2009, 48, 7230; Luminescence, 2007, 126, 447).

Contents of the invention

The invention provides an organic boron difluoride complex with high-intensity solid and liquid fluorescence in the visible light region.

The invention also provides a method for preparing the organic boron difluoride complex, which has mild conditions, short reaction time, high yield, and easy separation and purification of products.

An organic boron difluoride complex is a compound shown in the following structural formula I:

In structural formula I, R ₁ is OCH ₃ , H or Cl; R ₂ is OCH ₃ , H or Cl; R ₃ is H, NO ₂ , Br, CH ₃ or OCH ₃ ; R ₄ is H, NO ₂ , Br, _CH3 or _OCH3 .

A method for preparing an organic boron difluoride complex, comprising the steps of: reacting a ligand with boron trifluoride ether to prepare a compound shown in structural formula I:

In structural formula I, R ₁ is OCH ₃ , H or Cl; R ₂ is OCH ₃ , H or Cl; R ₃ is H, NO ₂ , Br, CH ₃ or OCH ₃ ; R ₄ is H, NO ₂ , Br, _CH3 or _OCH3 ;

The ligand is a compound shown in the following structural formula II:

R ₁ , R ₂ , R ₃ , and R ₄ in structural formula II have the same meanings as R ₁ , R ₂ , R ₃ , and R ₄ in structural formula I, respectively.

The boron trifluoride diethyl ether is preferably in excess in the reaction, and the molar ratio of ligand to boron trifluoride diethyl ether is preferably 1:3-5.

In order to achieve a better inventive effect, preferably:

The reaction conditions are as follows: stirring at 20°C-30°C for 30min-50min or heating at 55°C-65°C for 15min-25min and then crystallizing naturally, the obtained crystals are repeatedly washed with anhydrous ether to obtain organic boron difluoride Complexes.

An acid-binding agent (ie, an organic base) is added in the reaction to provide an alkaline environment, and the acid-binding agent is triethylamine, N, N-diisopropylethylamine or diethylamine.

The molar ratio of the acid-binding agent to the ligand is 2-3:1.

The reaction is performed in an anhydrous organic solvent, and the anhydrous organic solvent is one or more of ether, dichloromethane, chloroform, benzene, toluene, tetrahydrofuran, acetone, and ethyl acetate.

The organic boron difluoride complex of the present invention is composed of 2-(2-quinolyl)phenol and its derivatives of heterocyclic N, O-bidentate ligands and boron trifluoride ether under the condition of alkaline anhydrous solvent The reaction is obtained, taking room temperature or heating as an example, its chemical reaction formula is as follows:

Since the ligand has the structure of phenolic hydroxyl group, it can be converted into the corresponding phenolic oxygen anion form with alkali to enhance the coordination ability of the ligand. The applicable organic base is triethylamine, N, N-diisopropyl Ethylamine or diethylamine; the reaction is stirred in an anhydrous organic solvent at 20°C-30°C for 30min-50min or heated at 55°C-65°C for 15min-25min, and a powdery solid is precipitated, filtered and washed repeatedly with anhydrous ether After several times, the target complex is obtained after natural drying, and the yield is generally above 70%. Available organic solvents include ether, dichloromethane, chloroform, benzene, toluene, tetrahydrofuran, acetone, ethyl acetate, etc. one or more species.

Compared with prior art, the present invention has following advantage:

The organic boron difluoride complex of the present invention is a kind of ligand that uses 2-(2-quinolyl)phenol and its derivatives, has stable chemical properties, strong thermal stability, high fluorescence quantum yield, and large molar absorptivity coefficient And it is a new compound with high-brightness solid and liquid fluorescence. This complex can provide a new source for the preparation and development of luminescent materials, fluorescent probes, fluorescent tracers, information storage media, laser dyes, and photosensitizers for photodynamic cancer therapy. alternative materials.

The preparation method of the organic boron difluoride complex of the invention has mild conditions, short reaction time, high yield, and easy separation and purification of products.

Description of drawings

Fig. 1 is the ultraviolet absorption spectrum curve (a), the fluorescence emission spectrum curve (b) and its solid fluorescence emission curve (c) of complex 8 prepared in embodiment 8 in dichloromethane solution; Wherein, abscissa is wavelength ( Wavelength/nm), the vertical coordinates are UV absorbance value (Absorption Value) or fluorescence intensity (Fluorescence Intensity);

Fig. 2 is the fluorescence performance of the dichloromethane solution of complex 8 prepared in Example 8 under ultraviolet light irradiation;

Fig. 3 is the fluorescence performance of the solid of complex 8 prepared in Example 8 under ultraviolet light irradiation;

Fig. 4 is the infrared spectrogram of complex 6 prepared in Example 6 using the KBr tablet method; wherein, the abscissa is the wave number (Wavenumbers/cm ^-1 );

Fig. 5 is the proton nuclear magnetic resonance spectrum of complex 6 prepared in embodiment 6, the condition of proton nuclear magnetic resonance spectrum is: 400M Hz, DMSO-d ₆ is a solvent, and trimethylsilane (TMS) is an internal standard;

Fig. 6 is the carbon nuclear magnetic resonance spectrum of complex 6 prepared in Example 6. The conditions of the carbon nuclear magnetic resonance spectrum are: 100 M Hz, DMSO-d ₆ is the solvent, and TMS is the internal standard.

Detailed ways

Example 1

At room temperature, 2.81g (10mmol) of 2-(6,7-dimethoxy-2-quinolyl)phenol was placed in 15mL of toluene solution, and 4.2mL (30mmol) of triethylamine was added dropwise under stirring, 15 Minutes later, 2.8 mL (30 mmol) of boron trifluoride ether solution was added dropwise, and stirring was continued for 45 min after the addition was complete, gradually solid precipitated out. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain complex 1 in the form of light yellow powder with a yield of 81%.

The infrared spectrum, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the above-mentioned complex 1 are as follows:

IR(KBr): υ = 1603, 1516, 1250, 1083, 849 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=4.02(s, 3H), 4.15(s, 3H), 7.02(t, J=8.0Hz, 1H), 7.07(s, 1H), 7.19(d, J =8.4Hz, 1H), 7.48(t, J=8.0Hz, 1H), 7.83(d, J=8.0Hz, 1H), 7.94(d, J=8.8Hz, 1H), 8.29(m, 2H).

¹³ C NMR (DMSO-d ₆ ): δ=56.20, 56.62, 104.45, 105.70, 114.90, 116.38, 120.04, 120.29, 124.06, 126.12, 134.48, 137.67, 140.46, 149.81, 150.44, 154.5

Example 2

At room temperature, 2.56g (10mmol) of 2-(6-chloro-2-quinolyl)phenol was placed in 15mL of benzene solution, 3.7mL of triethylamine (27mmol) was added dropwise under stirring, and triethylamine was added dropwise after 15 minutes. Boron fluoride ether solution 4.2mL (45mmol), continue to stir for 45min after the addition, gradually solid precipitates out. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain complex 2 in the form of yellow powder with a yield of 76%.

The infrared spectrogram, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of above-mentioned complex 2 are as follows:

IR(KBr): υ = 1614, 1517, 1358, 1265, 1165, 1099, 930, 847, 754 cm ^-1 .

¹ H NMR (DMSO-d ₆ ): δ=7.07(t, J=7.6Hz, 1H), 7.20(d, J=8.4Hz, 1H), 7.56(t, J=7.6Hz, 1H), 7.63( d, J=8.4Hz, 1H), 7.84(d, J=8.8Hz, 1H), 7.90(d, J=8.4Hz, 1H), 8.15(d, J=8.8Hz, 1H), 8.47(d, J=8.8Hz, 1H), 8.96(s, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=117.31, 120.43, 120.67, 124.18, 124.28, 124.38, 125.97, 126.87, 129.24, 129.47, 136.12, 139.66, 142.43, 153.57, 156.44.

Example 3

At room temperature, 2.21g (10mmol) of 2-(2-quinolyl)phenol was placed in 10mL of ethyl acetate solution, and 2.9mL (21mmol) of triethylamine was added dropwise with stirring, and trifluorinated trifluoride was added dropwise after 15 minutes. Boron ether solution 2.8mL (30mmol), continue to stir for 45min after the addition, gradually a solid precipitates out. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain complex 3 in the form of yellow powder with a yield of 86%.

The infrared spectrum, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the above-mentioned complex 3 are as follows:

IR(KBr): υ = 1609, 1560, 1523, 1481, 1265, 1085, 922, ^{760 cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=7.06(t, J=7.6Hz, 1H), 7.21(d, J=8.4Hz, 1H), 7.54(t, J=8.0Hz, 1H), 7.69( t, J=7.6Hz, 1H), 7.91(m, 3H), 8.18(d, J=8.8Hz, 1H), 8.52(d, J=8.8Hz, 1H), 8.96(d, J=8.8Hz, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=117.08, 120.34, 120.47, 124.84, 124.92, 126.74, 127.64, 128.06, 128.41, 132.98, 135.64, 140.36, 142.81, 152.83, 156.39.

Example 4

At room temperature, put 2.66g (10mmol) of 4-nitro-2-(2-quinolyl)phenol in 10mL of acetone solution, add 4.2mL (30mmol) of triethylamine dropwise under stirring, and heat at 60°C After 15 minutes, 4.8 mL (50 mmol) of boron trifluoride diethyl ether solution was added dropwise. After the addition, the mixture was kept warm and stirred for 20 minutes, and a solid precipitated out gradually. The solid was collected by filtration, washed repeatedly with anhydrous diethyl ether, and naturally dried to obtain a khaki powder, powder complex 4, with a yield of 71%.

The infrared spectrogram, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of above-mentioned complex 4 are as follows:

IR(KBr): υ = 1615, 1513, 1329, 1074, 929, 846 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ = 7.35 (d, J = 8.8Hz, 1H), 7.91 (t, J = 7.6Hz, 1H), 8.11 (t, J = 7.6Hz, 1H), 8.39 ( d, J=8.4Hz, 1H), 8.47(d, J=9.2Hz, 1H), 8.71(d, J=8.4Hz, 1H), 8.96(d, J=8.4Hz, 1H), 9.14(d, J=9.2Hz, 1H), 9.26(s, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=118.48, 118.78, 118.95, 124.31, 126.88, 126.94, 127.27, 128.06, 131.29, 139.07, 139.42, 143.56, 155.56, 155.43, 165.96.

Example 5

At room temperature, 3.0 g (10 mmol) of 4-bromo-2-(2-quinolyl)phenol was placed in 10 mL of chloroform solution, and 4.2 mL (30 mmol) of triethylamine was added dropwise with stirring, and heated at 60° C. for 15 Minutes later, 4.8 mL (50 mmol) of boron trifluoride ether solution was added dropwise. After the addition was complete, the mixture was kept warm and stirred for 20 min, and a solid precipitated out gradually. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain complex 5 in the form of a khaki powder with a yield of 77%.

The infrared spectrogram, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of above-mentioned complex 5 are as follows:

IR(KBr): υ = 1607, 1555, 1523, 1479, 1348, 1089, 927, 828 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=6.99 (d, J=8.8Hz, 1H), 7.54 (d, J=8.8Hz, 1H), 7.70 (t, J=7.2Hz, 1H), 7.87( t, J=8.4Hz, 1H), 8.10(t, J=8.4Hz, 2H), 8.37(s, 1H), 8.45(d, J=8.8Hz, 1H), 8.63(d, J=8.8Hz, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=110.11, 118.58, 120.17, 120.92, 126.65, 126.90, 127.36, 127.99, 130.18, 131.12, 134.52, 138.77, 143.81, 156.07, 159.02.

Example 6

At room temperature, 2.34g (10mmol) of 4-methyl-2-(2-quinolyl)phenol was placed in 15mL of dichloromethane solution, and 3.5mL of N,N-diisopropylethylamine was added dropwise with stirring (20mmol), after 15 minutes, 2.8mL (30mmol) of boron trifluoride diethyl ether solution was added dropwise, and stirring was continued for 45min after the addition was complete, and a solid precipitated out gradually. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain yellow-green powder complex 6 with a yield of 91%.

The infrared spectrogram, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of above-mentioned complex 6 are as follows:

IR(KBr): υ=1620, 1560, 1524, 1496, 1384, 1325, 1265, 1100, 1077, 920, 831.755 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=2.39(s, 3H), 7.11(d, J=8.4Hz, 1H), 7.35(d, J=8.8Hz, 1H), 7.67(m, 2H), 7.89 (m, 2H), 8.16 (d, J=8.8Hz, 1H), 8.49 (d, J=8.8Hz, 1H), 8.95 (d, J=9.6Hz, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=20.84, 117.11, 120.07, 124.71, 124.80, 124.89, 126.45, 127.56, 127.93, 128.37, 129.63, 132.89, 136.84, 142.64, 152.83.38, 154.

Example 7

At room temperature, put 2.34g (10mmol) of 5-methyl-2-(2-quinolyl)phenol in 15mL of tetrahydrofuran solution, add 2.1mL (20mmol) of diethylamine dropwise under stirring, and dropwise add Boron trifluoride diethyl ether solution 2.8mL (30mmol), continue to stir for 45min after the addition, gradually solid precipitates out. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain yellow-green powder complex 7 with a yield of 94%.

The infrared spectrum, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the above-mentioned complex 7 are as follows:

IR(KBr): υ = 1616, 1553, 1526, 1262, 1086, 090 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=2.40(s, 3H), 6.84(d, J=8.0Hz, 1H), 7.00(s, 1H), 7.64(t, J=7.6Hz, 1H), 7.76(d, J=8.4Hz, 1H), 7.87(t, J=7.6Hz, 2H), 8.08(d, J=8.8Hz, 1H), 8.43(d, J=8.8Hz, 1H), 9.92( d, J=8.8Hz, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=21.25, 118.04, 118.17, 119.03, 121.91, 123.15, 127.44, 127.90, 128.03, 129.27, 132.05, 139.01, 143.96, 146.95, 152.31, 155.3

Example 8

At room temperature, 2.51g (10mmol) of 5-methoxy-2-(2-quinolyl)phenol was placed in 15mL of toluene solution, and N,N-diisopropylethylamine 3.5mL was added dropwise under stirring ( 20mmol), after 15 minutes, 2.8mL (30mmol) of boron trifluoride diethyl ether solution was added dropwise. After the addition, the stirring was continued for 45min, and a solid precipitated out gradually. The solid was collected by filtration, washed repeatedly with anhydrous ether, and naturally dried to obtain yellow-green powder complex 8 with a yield of 83%.

The infrared spectrogram, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of above-mentioned complex 8 are as follows:

IR(KBr): υ = 1617, 1557, 1380, 1263, 1224, 1080, 910, 833 ^{cm -1} .

¹ H NMR (DMSO-d ₆ ): δ=3.88 (s, 3H), 6.62 (m, 2H), 7.61 (t, J=7.6Hz, 1H), 7.84 (m, 3H), 8.00 (d, J =9.2Hz, 1H), 8.37(d, J=9.2Hz, 1H), 8.87(d, J=8.8Hz, 1H).

¹³ C NMR (DMSO-d ₆ ): δ=55.69, 102.51, 110.03, 116.69, 124.29, 124.38, 124.47, 126.98, 127.43, 128.08, 128.35, 132.73, 142.19, 152.65, 158.73, 166.

Detected by infrared spectrum, proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum, it is shown that the complex 1-8 prepared in embodiment 1-8 has the following structure:

Complex 1: R ₁ =OCH ₃ , R ₂ =OCH ₃ , R ₃ =R ₄ =H; pale yellow powder, melting point: 272-273°C;

Complex 2: R ₁ =Cl, R ₂ =R ₃ =R ₄ =H; yellow powder, melting point: 262-264°C;

Complex 3: R ₁ =R ₂ =R ₃ =R ₄ =H; yellow powder, melting point: 264-265°C;

Complex 4: R ₁ ＝R ₂ ＝R ₄ ＝H, R ₃ ＝NO ₂ ; khaki powder, melting point: >300°C;

Complex 5: R ₁ =R ₂ =R ₄ =H, R ₃ =Br; khaki powder, melting point: 294-295°C;

Complex 6: R ₁ =R ₂ =R ₄ =H, R ₃ =CH ₃ ; yellow-green powder, melting point: 264-265°C;

Complex 7: R ₁ =R ₂ =R ₃ =H; R ₄ =CH ₃ ; yellow-green powder, melting point: 257-259°C;

Complex 8: R ₁ =R ₂ =R ₃ =H; R ₄ =OCH ₃ ; yellow-green powder, melting point: 243-244°C.

Under the irradiation of ultraviolet light, the solid and organic solution of the organic boron difluoride complex of the present invention exhibit bright fluorescence, and the color of the solid fluorescence is generally yellow-green (except for a few, which are cyan), while the fluorescence color of the solution is from blue to blue. Cyan, blue-green gradually transition. Taking complexes 1-8 as an example, the spectral properties can be seen in Table 1 below:

Spectral properties of the complexes in Table 1

Note 1: Spectral properties are all measured in dichloromethane solution at room temperature;

Note 2: Fluorescence quantum yield Φ takes quinine sulfate (Φ=0.55, 0.5mM sulfuric acid aqueous solution) as a reference, and is measured by dilute solution comparison method.

It can be seen from the data in Table 1 that, except for the complexes containing electron-withdrawing substituents on the phenolic ring, the organic solutions and solids of the other complexes exhibit strong fluorescence under ultraviolet light irradiation. The ultraviolet absorption wavelength is in the range of 363nm-394nm, the fluorescence emission wavelength is in the range of 441nm-502nm, and the fluorescence quantum yield is in the range of 0.13-0.96.

When the electron-withdrawing substituent is attached to the phenolic ring, the fluorescence of the complex is significantly weakened, which can be reflected from the quantum yield data of the corresponding complex, which makes its solid-state fluorescence impossible to measure, even when the substituent is When the nitro group is added, the complex has completely lost its fluorescence properties. Although the introduction of electron-withdrawing groups on the quinoline ring also reduced the quantum yield of the complexes, the effect was not as strong as that on the phenol ring. No matter on the quinoline ring or the phenolic ring, the introduction of electron-repelling groups is beneficial to the enhancement of the fluorescence properties of the complex, but it seems that the electron-repelling groups on the phenolic ring have a greater fluorescence enhancement effect, especially when the electron-repelling groups are in the phenolic oxygen The meta position of the atom. It can be seen that the change of the electrical properties of the substituents on the phenol ring has a more significant impact on the overall fluorescence properties of the complex. Due to the introduction of substituents on the phenol ring or quinoline ring increases the steric hindrance, making it impossible to produce dense packing between molecules, reducing the intermolecular interactions such as π-π attraction, coupled with a large Stock's shift to eliminate Self-quenching, thus leading to strong solid-state fluorescence emission from the complex.

Claims (7)

1. an organic boron difluoride complex, is characterized in that, is the compound shown in following structural formula I:

In structural formula I, R ₁ is OCH ₃ , H or Cl; R ₂ is OCH ₃ , H or Cl; R ₃ is H, NO ₂ , Br, CH ₃ or OCH ₃ ; R ₄ is H, NO ₂ , Br, _CH3 or _OCH3 . 2. A preparation method of an organic boron difluoride complex, comprising the steps of: reacting a ligand with boron trifluoride ether to obtain a compound shown in structural formula I:

In structural formula I, R ₁ is OCH ₃ , H or Cl; R ₂ is OCH ₃ , H or Cl; R ₃ is H, NO ₂ , Br, CH ₃ or OCH ₃ ; R ₄ is H, NO ₂ , Br, _CH3 or _OCH3 ; The ligand is a compound shown in the following structural formula II:

R ₁ , R ₂ , R ₃ , and R ₄ in structural formula II have the same meanings as R ₁ , R ₂ , R ₃ , and R ₄ in structural formula I, respectively. 3. The preparation method of the organic boron difluoride complex according to claim 2, characterized in that the molar ratio of the ligand to boron trifluoride ether is 1:3-5. 4. The preparation method of organic boron difluoride complex according to claim 2, characterized in that, the reaction conditions are: stirring at 20°C-30°C for 30min-50min or heating at 55°C-65°C After 15min-25min, natural crystallization was carried out, and the obtained crystals were repeatedly washed with anhydrous ether to obtain organic boron difluoride complexes. 5. according to the preparation method of the described organic boron difluoride complex of claim 2 or 4, it is characterized in that, in the described reaction, add acid-binding agent, described acid-binding agent is triethylamine, N, N - diisopropylethylamine or diethylamine. 6. The preparation method of organic boron difluoride complex according to claim 5, characterized in that the molar ratio of the acid-binding agent to the ligand is 2-3:1. 7. according to the preparation method of the described organic boron difluoride complex of claim 2 or 4, it is characterized in that, described reaction is carried out in anhydrous organic solvent, and described anhydrous organic solvent is diethyl ether, dichloro One or more of methane, chloroform, benzene, toluene, tetrahydrofuran, acetone, ethyl acetate.

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