CN100532378C - Photosensitive luminescent europium complex and its photosensitive ligand molecule and their synthesis method - Google Patents

Abstract

This invention relates to a photosensitive shining Europium complex and its photosensitive ligand molecule, also relates to the synthetic method. The Europium complex structure is showd as VI: the R1, R2 is alkyl with 1 to 4 carbon atoms, R3, R4, R5, and R6 are same and are methyl or H, the R8 is methyl or H. The organic photosensitive ligand molecule structural formula is showd as I: the R1, R2 is alkyl with 1 to 4 carbon atoms, R3, R4, R5, and R6 are same and are methyl or H, the R8 is methyl or H. The photoallergy molecule possess fine long wave photoactivate Europium ion luminance. The new style Europium complex possess width activating window, at the same time possess large two-photon absorption acting section and / or high rare earth ion fluorescence quanta yield, is useful for preparing excellent bioluminescence probe stuff, possess comprehensive application prospects.

Description

Photosensitive luminescent europium complex and its photosensitive ligand molecule and their synthesis method

technical field

The invention relates to photosensitive luminescent europium complexes, photosensitive ligand molecules and their synthesis methods.

Background technique

The unique electronic structure of rare earth ions, especially the shielding effect of its 5P66S2 electrons on the 4f orbital, makes its compounds have many special spectral properties. They have important application value in light-emitting devices (energy-saving lamps, light-emitting diodes, displays), optical fibers, optical amplifiers, lasers, biosensing, bioimaging, and fluorescent immunoassays. The sharp line emission of rare earth ions in the visible or near-infrared region and the long luminescent state lifetime (ms level) can reduce the fluorescence interference generated by the biological material itself, so that the detection has high sensitivity and efficiency, and at the same time avoids the use of radioactive element bands. A series of questions to come.

Since the f-f transition of rare earth ions is limited by the electric dipole selection rate, the light absorption ability of rare earth ions itself is very weak, and the molar extinction coefficient is very small. Therefore, to obtain better luminescence performance, rare earth ions need to be sensitized, that is, by The ligand (or charge transfer state) as a sensitizer absorbs light and transfers the energy to the light emitting state of rare earth ions to achieve high-efficiency light emission of rare earth ions. Although many rare earth complexes can be excited by ultraviolet light to obtain better luminescent properties, ultraviolet light can cause greater damage and interference to organisms, and will also produce strong background fluorescence. Therefore, the excitation window of rare earth complexes is extended to the long-wave direction. And improving its fluorescence quantum yield under long-wave light excitation has become one of the important research directions (K. Kuningas, et al., Anal. Chem. 2005, 77, 7348).

WO patent WO2003076938-A reports two types of rare earth ion sensitizing molecules containing terpyridine and bipyrazole-pyridine structures. Wherein N, N, N', N'-[(4'-(5"'-amino-2"'-thienyl)-2,2':6',2"-terpyridine-6,6" -diyl)bis(methylenenitrile)]acetic acid (N,N,N',N'-[(4'-(5"'-amino-2"'-thienyl)-2,2':6 ',2"-terpyridine-6,6"-diyl)bis(methylenenitrilo)]tetrakis(acetate)) as a sensitizing ligand, the peak of the excitation spectrum of the Eu ³⁺ complex appears at 336 nm, and the tail of the excitation window extends to 410nm, the fluorescence quantum yield is 0.15.

The excitation window of the Michler ketone-sensitized Eu(Fod) ₃ (Fod=6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) complex system can be extended to Above 450nm, however, even under deoxygenated conditions, its fluorescence quantum yield is only 0.2 (MHVWerts, et al., Chem.Commun.1999, 799-800).

The inventors of the present invention once reported a rare earth complex [Eu(tta) ₃ dpbt] (dpbt is shown in the structural formula II, and tta is the anion of thiophenoyltrifluoroacetone). The excitation window of this complex dissolved in toluene (dilute solution with a concentration of 10 ^-5 M) can be extended to 441nm, and the complex has a very high luminescence quantum yield (0.52) (Y.Wang, et al., Angew .Chem.Int.Ed.2004, 43, 5010). [Eu(tta) ₃ dpbt] also has good two-photon sensitized luminescence performance, and its two-photon absorption cross section (δ×Φ _F ) is as high as 82GM at 808nm, which can efficiently emit pure red light (JP Zhang, Y. Wang, et al., Angew. Chem. Int. Ed. 2005, 44, 747). The two-photon absorption-sensitized luminescence approach effectively expands the wavelength range of the excitation light, enabling the excitation light wavelength to be in the near-infrared region with greater penetrability and little damage or interference to biological samples. If such probe materials are used to synthesize new fluorescent biological probes, near-infrared laser excitation is used in fluorescence immunoassay, which will make fluorescence immunoassay have the advantages of high sensitivity, high signal-to-noise ratio and large penetration depth.

Recently, Werts et al. reported the two-photon-sensitized luminescence properties of four organic rare earth complex systems (MHVWerts, et al., Photochem.Photobiol.Sci.2005, 4, 531), among which the two-photon-sensitized luminescence properties The best Michler ketone-sensitized Eu(Fod)3) complex system has a two-photon absorption cross section (δ×Φ _F ) of 43GM under 810nm laser excitation, and its two-photon absorption cross section under 840nm laser excitation Below 25GM.

Further expanding the excitation window of rare earth fluorescent dyes to the long-wave direction can obtain greater penetration depth in applications such as biological imaging and fluorescent immunoassays, further reduce damage and interference to biological samples and is expected to obtain higher detection sensitivity .

It is of great application value to create a new type of rare earth complex luminescent material, which has a wide single-photon and two-photon excitation window, a large two-photon absorption cross section and/or a high rare earth ion fluorescence quantum yield. The construction of such rare earth complexes requires photosensitizing ligand molecules with excellent properties.

(式II，dpbt)

(Formula II, dpbt)

In the synthetic method of dpbt (as shown in structural formula II) reported in literature (Y.Wang, et al., Angew.Chem.Int.Ed.2004,43,5010), the intermediate product N,N-diethylamine phenyl -The synthetic method of dichlorotriazine is that N, N-diethylaniline and tripolychlorazine (cyanuric chloride, cyanuric chloride) are directly mixed and heated. Because tripolychlorazine attacks the diethylamine group of reactant simultaneously, the reaction generates a large amount of by-products, adopts the intermediate product N of this synthetic method gained, the productive rate of N-diethylamine phenyl-dichlorotriazine is low at 25%. At the same time, because there is a large amount of excess tripolychlorazine in the reaction system, it is difficult to separate the product, so the yield of the final target product dpbt is low, about 20%.

Contents of the invention

The object of the present invention is to provide photosensitive luminescent europium complexes and their photosensitive molecular ligands with wide excitation window, large two-photon absorption cross section and/or high rare earth ion fluorescence quantum yield and their synthesis method.

The structure of the photosensitive molecular ligand provided by the present invention is shown in formula I:

(Formula I)

In formula I, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₃ =R ₄ =R ₅ =R ₆ is methyl or H, R ₇ is methyl, R ₈ is methyl or H ; In the formula I, preferably R ₁ and R ₂ are ethyl, and R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ is methyl.

The structure of the photosensitive luminescent europium complex provided by the present invention is shown in formula VI:

(Formula VI)

In formula VI, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₃ =R ₄ =R ₅ =R ₆ is methyl or H, R ₇ is methyl, R ₈ is methyl or H ; In the formula VI, R ₁ and R ₂ are preferably ethyl, and R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ is methyl.

The synthesis method of the above-mentioned photosensitive molecular ligand provided by the present invention comprises the following steps:

1) P-N, N-dialkylamino-2,6-dimethylphenyllithium or p-N, N-dialkylamino-2-methylphenyllithium and tripolychlorazine (cyanide Urea acid chloride, cyanuric chloride) reaction, makes the substituted triazine compound shown in formula IV;

2) reacting the substituted triazine compound obtained in step 1) with the pyrazole anion or substituted pyrazole anion shown in formula V to prepare the photosensitive organic molecule ligand shown in formula I;

(Formula IV) (Formula V)

Wherein in formula IV, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₇ is methyl, R ₈ is methyl or H, and in formula V, R ₃ =R ₅ is methyl or H.

In the method, the N, N-dialkylamino-2,6-dimethylphenyllithium or the N, N-dialkylamino-2-methylphenyllithium can be The product obtained by reacting the compound shown in formula III with alkyllithium;

(Formula III)

In formula III, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₇ is methyl, R ₈ is methyl or H, and X is halogen elements such as I, Br, and Cl.

In the method, the reaction temperature of the halogenated aniline represented by the formula III and the alkyllithium may be -78-50°C.

The number of carbon atoms of the alkyllithium is 1-8.

In the method, the N, N-dialkylamino-2,6-dimethylphenyllithium or the N, N-dialkylamino-2-methylphenyllithium and trimerized Chlorazine reaction temperature is -78—50°C.

In the method, in the step 1), it also includes the p-N,N-dialkylamino-2,6-dimethylphenyllithium or the p-N,N-dialkylamino- The product obtained by the reaction of 2-methylphenyllithium and tripolychlorazine is purified by a silica gel column to obtain a purified substituted triazine compound represented by formula IV; the eluent for purification is dichloromethane or chloroform.

In the method, in the step 2), the molar ratio of the compound represented by the formula IV to the pyrazole anion or substituted pyrazole anion represented by the formula V is 1:2-10.

In the method, in the step 2), it also includes chromatographically separating the product of the reaction between the substituted triazine compound and the pyrazole anion or substituted pyrazole anion shown in formula V, and then performing recrystallization to obtain purified A photosensitive organic molecule ligand shown in formula I.

The method for synthesizing the above-mentioned europium complex provided by the present invention is to react the photosensitive organic molecular ligand prepared above with the compound represented by formula XXII to obtain the europium complex.

(式XXII)

(Formula XXII)

The method also includes purifying the europium complex obtained by the reaction, the purification method is to add a poor solvent to the complex solution to precipitate the complex; the poor solvent is selected from petroleum ether, n-hexane, cyclohexane One or more than one of alkanes in any combination.

In the above preparation method of photosensitive organic molecular ligand and europium complex, the reaction can be carried out in many organic solvents, such as tetrahydrofuran, ether, benzene, toluene, chloroform, dichloromethane and other solvents.

There are significant structural differences between the photosensitive organic molecular ligand of the present invention and our recently reported dpbt (structure shown in formula II). In particular, the (CH ₂ ) ₂ N-plane of the R ₁ R ₂ N-group in the compound shown in formula I has a large distance from the plane of the benzene ring due to the steric hindrance of the 2, 6 or 2 methyl groups of the benzene ring. When both the 2 and 6 positions have methyl groups, the included angle is close to 90 degrees, and the N in the ground state is sp ³ hybridized; and in the dpbt molecule, the (C ₂ H ₅ )N-group (CH ₂ ) _{The 2} N-plane is coplanar with the benzene ring, and N is sp ² hybridized in the ground state. This structural change unexpectedly leads to the europium complex of the present invention having the structure shown in formula VI to have more excellent two-photon sensitized luminescent properties and a wider visible light excitation window. For example, when R ₁ ＝R ₂ ＝H ₃ CH ₂ C-, R ₃ ＝R ₄ ＝R ₅ ＝R ₆ ＝R ₇ ＝R ₈ ＝H ₃ C- in Formula VI, the two-photon absorption of complex XIV The cross-section is as high as 85GM, and its two-photon excitation window is greatly extended to the long-wave direction. At 842nm, its two-photon absorption cross-section is as high as 56GM (see Figure 1), and the tail of the two-photon excitation window extends to 890nm. However, the two-photon absorption cross-section of the compound synthesized by dpbt as shown in formula VII is significantly lower when the wavelength is greater than 810nm, and the two-photon absorption cross-section at 820nm is about 36GM, and there is almost no two-photon sensitivity at wavelengths greater than 850nm. Chemiluminescent ability (see Figure 2). The complex compound with the structure of formula XIV of the present invention is the europium complex with the best long-wave laser two-photon sensitized luminescent performance so far. Experiments have proved that the new complex represented by the formula VI has excellent visible light-sensitized luminescent ability, and its europium ion fluorescence quantum yield is greater than 0.4. The excitation window of the new complex represented by formula VI dissolved in toluene solution (with a concentration of 10 ⁻⁵ M) can be extended to more than 450 nm. However, the excitation window of the complex represented by formula VII dissolved in toluene solution (with a concentration of 10 ⁻⁵ M) can be extended to 441 nm. Compared with the complex shown in formula VII, the new complex shown in formula VI has a wider visible light excitation window.

    (式VII)    

   (式XIV)

(Formula VII)

(Formula XIV)

The photosensitive molecule provided by the present invention has excellent long-wave sensitized luminescent ability, and the novel europium complex provided by the present invention has a very wide excitation window, and at the same time has a large two-photon absorption cross section and/or high fluorescence quantum yield of rare earth ions , which has important application value in bioprobe synthesis, biosensing, imaging and fluorescence immunoassay.

In the synthesis method of the present invention, when synthesizing the key intermediate product shown in formula IV, the carbanion formed by the reaction of the compound of formula III with the alkyllithium is used to attack tripolychlorazine, avoiding the trimerization in the direct heating synthesis method Chlorazine easily attacks the dialkylamine group in dialkylamino-2,6-dimethylbenzene or dialkylamino-2-methylbenzene to generate a large amount of by-products. Adopt the synthetic method of the present invention, can obtain the structure as the key intermediate product shown in formula IV with high yield (greater than 50%); The method of the mixture of base benzene or dialkylamino-2-methylbenzene synthesizes the key intermediate product shown in IV formula, then its productive rate is less than 5%. Therefore, the novel photosensitizing ligand molecular compound with the structure shown in formula II and the novel photoluminescent europium complex with the structure shown in formula VI can be obtained with high yield by using the synthesis method provided by the invention.

Description of drawings

Fig. 1 is the two-photon absorption sectional view (λ _em =614nm) of the compound of the present invention (structure such as formula XIV);

Figure 2 is a cross-sectional view of the reported two-photon absorption of the compound [Eu(tta) ₃ dpbt] (λ _em =614nm).

Detailed ways

In order to illustrate the present invention more specifically, several examples are given. However, the content involved in the present invention is not limited to these examples. The methods in the following examples are conventional methods unless otherwise specified. The raw materials used in the reaction are all commercially available.

The synthetic method of photosensitive molecule of the present invention, its reaction process is as follows:

Among them, in formula I, formula IV, formula III, and formula XXIII, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₇ is methyl, R ₈ is methyl or H, formula I, formula V R ₃ ＝R ₄ ＝R ₅ ＝R ₆ is methyl or H; in formula III, X is a halogen element such as I, Br, Cl; in R'Li, R' is an alkyl group with 1-8 carbon atoms .

The synthesis method of the organic photosensitive molecule of the present invention may specifically comprise the following steps:

1) P-N, N-dialkylamino-2,6-dimethylphenyllithium or p-N, N-dialkylamino-2-methylphenyllithium and tripolychlorazine (cyanide Urea acid chloride, cyanuric chloride) reaction, makes the substituted triazine compound shown in formula IV;

2) reacting the substituted triazine compound obtained in step 1) with the pyrazole or substituted pyrazole anion shown in formula V to prepare the photosensitized organic ligand compound shown in formula I;

The synthetic method of europium complex of the present invention, its reaction process is as follows

Among them, in formula I and formula VI, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₃ =R ₄ =R ₅ =R ₆ is methyl or H, R ₇ is methyl, R ₈ is methyl or H.

Example 1, 2-(N,N-diethyl-2,6-dimethylanilino-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)- 1,3,5-triazine (C ₂₅ H ₃₂ N ₈ , formula VIII, that is, in formula I, R ₁ =R ₂ =H ₃ CH ₂ C-, R ₃ =R ₄ =R ₅ =R ₆ =R ₇ ＝R ₈ ＝H ₃ C-) Synthesis of Photosensitive Ligand Molecular Compound

Take 4mmol of N,N-diethyl-2,6-dimethyl-p-bromoaniline, dissolve it in dried tetrahydrofuran, pass through argon to remove oxygen, place it in a dry ice acetone bath at -78°C, and dissolve it in argon Under protection, add 6.4mmol n-BuLi, slowly warm up to room temperature, continue to stir for 30min, add it to 5.4mmol of tripolychlorazine frozen at -78°C, slowly warm up to room temperature, continue to stir for 60min. After removal of the solvent, the product was chromatographed on a silica gel column with dichloromethane as the eluent. The obtained crude product was recrystallized in petroleum ether to obtain 2-(N,N-diethyl-2,6-dimethylaniline-4-yl)-4,6-dichloro-1,3,5- Triazine yellow needle crystal 0.65g. Under the protection of argon, add 1.25 mmol of freshly cut potassium metal into anhydrous tetrahydrofuran; add 1.75 mmol of 3,5-dimethylpyrazole, heat and reflux for 3 hours to generate 3,5-dimethylpyrazole anion; The reaction mixture was placed in an ice bath, and 2-(N,N-diethyl-2,6-dimethylanilino-4-yl)-4,6-dichloro-1,3,5-tri Oxyzine 0.5mmol, stirred at room temperature for 1h, and then refluxed in an oil bath at 80-85°C for 8-9h. After cooling, concentrate, and use a mixture of dichloromethane and ethyl acetate (the volume ratio of dichloromethane to ethyl acetate is 3:1) as eluent, and separate by silica gel column chromatography. The obtained crude product was recrystallized from a mixture of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 1:1), and 90 mg of yellow needle-like crystals were obtained.

The obtained crystal is subjected to mass spectrometry analysis, and mass spectrometry (EIMS) analysis records molecular ion peak M/Z=444; Elemental analysis value (mass percentage composition): C, 67.20% (67.54%); H, 7.11% (7.25% ); N, 25.13% (25.20%), the theoretical values in brackets. Single crystal X-ray analysis and nuclear magnetic resonance spectrum prove that the structure of the product is shown in formula VIII.

(式VIII)

(Formula VIII)

Example 2, Synthesis of Europium Complex [Eu(tta) ₃ VIII] (EuC ₄₉ H ₄₄ N ₈ F ₉ O ₆ S ₃ )

Under argon protection, 10 mL of Eu(tta) ₃ 3H ₂ O (0.03 mmol) in tetrahydrofuran was added dropwise to 10 mL of the compound of formula VIII (0.03 mmol) prepared in Example 1 in tetrahydrofuran. Stir for 30min. Remove the solvent, dissolve and filter with a small amount of ether, use n-hexane as a precipitant to precipitate a solid, wash it, and dry it to obtain 27 mg of a yellow powder.

The obtained yellow powder was subjected to mass spectrometry analysis, and the mass spectrometry (MALDI-TOF MS) characterization showed that the molecular ion peak M/Z=1260; elemental analysis (mass percentage): C, 46.80% (46.71%); H, 3.43% (3.52%); N, 9.01% (8.89%), the theoretical value in brackets; NMR analysis shows that the product is [Eu(tta) ₃ VIII], and its structure is shown in Formula XIV.

Complex [Eu (tta) ₃ VIII] is dissolved in toluene, chooses the RhodamineB of known two-photon absorption cross section value as standard substance, according to literature (JP Zhang, Y.Wang, et al., Angew.Chem.Int.Ed .2005,44,747) method to measure its two-photon absorption cross-section, and its two-photon absorption cross-section is shown in Figure 1. The maximum two-photon absorption cross section of the complex is as high as 85GM, and its two-photon absorption cross section is as high as 56GM at 842nm, and the tail of the two-photon excitation window extends to 890nm.

(Formula XIV)

Figure 2 is the two-photon absorption cross section of our recently reported [Eu(tta) ₃ (dpbt)] complex (Y.Wang, et al., Angew.Chem.Int.Ed.2004, 43, 5010), The maximum two-photon absorption cross-section of the complex is 82GM, and its two-photon absorption cross-section is 36GM under 820nm laser excitation, and [Eu(tta) ₃ (dpbt)] has almost no two-photon sensitivity when excited by a laser with a wavelength greater than 850nm. luminescence ability. Comparing Fig. 1 and Fig. 2, it can be found that the [Eu(tta) ₃ VIII] complex provided by the present invention has more excellent two-photon sensitized luminescence performance.

The complex [Eu(tta) ₃ VIII] was dissolved in toluene, and the dimethyl sulfoxide solution of 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyrl-4H-pyran (DCM) was used as a reference (Φ=0.8 , JMDrake, et.al., Chem.Phys.Lett.1985, 113, 530-534.), under the irradiation of excitation light with a wavelength of 411nm, the europium ion fluorescence quantum yield of [Eu(tta) ₃ VIII] was measured It is 0.58 (detection wavelength is 614nm). The experimental results show that the excitation window of [Eu(tta)3VIII] complex dissolved in toluene solution (concentration: 10 ^-5 M) can be extended to 458nm.

Example 3, 2-(N,N-dimethyl-2,6-dimethylanilino-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)- 1,3,5-triazine (C ₂₃ H ₂₈ N ₈ , formula IX, that is, in formula I, R ₁ =R ₂ =R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ =H ₃ C -) Synthesis of photosensitive ligand molecular compound

Take 4mmol of N,N-dimethyl-2,6-dimethyl-p-bromoaniline, dissolve it in dried tetrahydrofuran, pass through argon to remove oxygen, put it in a dry ice acetone bath at -78°C, and dissolve it in argon Under protection, add 6.4 mmol of ethyllithium, slowly warm up to room temperature, continue stirring for 30 min, add it to 5.4 mmol of tripolychlorazine frozen at -78°C, slowly warm up to room temperature, and continue stirring for 60 min. After removal of the solvent, the product was chromatographed on a silica gel column with dichloromethane as the eluent. The obtained crude product was recrystallized in petroleum ether to obtain 2-(N,N-dimethyl-2,6-dimethylanilin-4-yl)-4,6-dichloro-1,3,5- Triazine pale yellow needle-like crystal 0.61g. Under the protection of argon, add 5.0 mmol of freshly cut potassium metal into anhydrous tetrahydrofuran; add 6.0 mmol of 3,5-dimethylpyrazole, heat and reflux for 3 hours to generate 3,5-dimethylpyrazole anion; The mixture was placed in an ice bath, to which was added 2-(N,N-dimethyl-2,6-dimethylanilin-4-yl)-4,6-dichloro-1,3,5 - Triazine 0.5 mmol, stirred at room temperature for 1 h, and then refluxed in an oil bath at 80-85° C. for 8-9 h. Concentrate after cooling, and use a mixture of dichloromethane and ethyl acetate (the volume ratio of dichloromethane to ethyl acetate is 2:1) as the eluent to separate by silica gel column chromatography. The obtained crude product was recrystallized with a mixture of petroleum ether and dichloromethane (the volume ratio of petroleum ether and dichloromethane was 1:1), and 43 mg of yellow needle-like crystals were obtained.

The compound of gained is carried out mass spectrum analysis, mass spectrometry (EI MS) analysis records molecular ion peak M/Z=416; Elemental analysis (mass percentage composition): C, 66.11% (66.32%); H, 6.83% (6.78% ); N, 26.97% (26.90%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product prepared above is shown in formula IX.

(Formula IX)

Embodiment 4, synthesis of europium complex [Eu(tta) ₃ IX] (EuC ₄₇ H ₄ 0N ₈ F ₉ O ₆ S ₃ )

25 mg of the complex [Eu(tta) ₃ IX] was synthesized according to the synthesis method of Example 2, using the compound shown in Formula IX as a ligand.

Mass spectrometry (MALDI-TOF MS) analysis measured the complex molecular ion peak M/Z=1232; elemental analysis value (mass percentage): C, 45.70% (45.82%); H, 3.30% (3.27%) ; N, 9.14% (9.10%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XV.

According to the method described in Example 2, with the dimethyl sulfoxide solution of DCM as a reference (Φ=0.8), under the irradiation of excitation light with a wavelength of 411nm, the fluorescence quantum yield of europium ions of the complex of formula XV is measured to be 0.50 (The detection wavelength is 614nm), and the fluorescence excitation window is extended to 455nm.

    (式XV)

(Formula XV)

Example 5, 2-(N,N-dibutyl-2,6-dimethylanilino-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)- 1,3,5-triazine (C ₂₉ H ₄₀ N ₈ , formula X, that is, in formula I, R ₁ =R ₂ =n-Bu, R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ =H ₃ C-) Synthesis of Photosensitive Ligand Molecular Compound

According to the synthesis method of Example 1, replace N, N-diethyl-2,6-dimethyl-p-bromoaniline with N,N-dibutyl-2,6-dimethyl-p-bromoaniline, synthesize 2-(N,N-dibutyl-2,6-dimethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3 , 5-triazine compound 80 mg.

The obtained compound is subjected to mass spectrometry analysis, and mass spectrometry (EI MS) analysis records molecular ion peak M/Z=500; Elemental analysis value (mass percentage composition): C, 69.45% (69.57%); H, 8.14% (8.05% %); N, 22.49% (22.38%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula X.

    (式X)

(Formula X)

Example 6, Synthesis of Europium Complex [Eu(tta) ₃ X] (EuC ₅₃ H ₅₂ N ₈ F ₉ O ₆ S ₃ )

Using the compound represented by formula X as a ligand, 30 mg of the complex was synthesized according to the synthesis method of Example 2.

The obtained complex is subjected to mass spectrometry analysis, mass spectrometry (MALDI-TOF MS) analysis records molecular ion peak M/Z=1316; Elemental analysis value (mass percentage content): C, 48.40% (48.36%); H, 3.91 % (3.98%); N, 8.55% (8.51%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XVI.

According to the method described in Example 2, taking the dimethyl sulfoxide solution of DCM as a reference (Φ=0.8), under the irradiation of excitation light with a wavelength of 411nm, the fluorescence quantum yield of europium ions of the complex of formula XVI is measured to be 0.49 (The detection wavelength is 614nm), and the fluorescence excitation window is extended to 456nm.

According to the method described in Example 2, the two-photon excitation luminescence performance of the complex [Eu(tta) ₃ X] was tested, and its two-photon absorption cross-section reached 75 GM, and its two-photon absorption cross-section reached 40 GM at 842 nm, and the two-photon excitation The tail of the window extends to 880nm.

(Formula XVI)

Example 7, 2-(N,N-diethyl-2-methylanilino-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3 , 5-triazine (C ₂₄ H ₃₀ N ₈ , formula XI, that is, in formula I, R ₁ =R ₂ =H ₃ CH ₂ C-, R ₃ =R ₄ =R 5 =R ₆ = _{R 7 =} H ₃ C-, R ₈ ＝H) Synthesis of Photosensitive Ligand Molecular Compound

According to the synthesis method of Example 1, replace N, N-diethyl-2,6-dimethyl-p-bromoaniline with N, N-diethyl-2-methyl-p-bromoaniline, and synthesize 2- (N,N-diethyl-2-methylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine compound 75mg.

The obtained compound is subjected to mass spectrometry analysis, mass spectrometry (EI MS) analysis records this compound molecular ion peak M/Z=430; Elemental analysis value (mass percentage composition): C, 66.73% (66.95%); H, 7.08% (7.02%); N, 26.15% (26.03%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XI.

    (式XI)

(Formula XI)

Example 8, Synthesis of Europium Complex [Eu(tta) ₃ XI](EuC ₄₈ H ₄₂ N8F ₉ O ₆ S ₃ )

Under argon protection, 10 mL of Eu(tta) ₃ ·3H ₂ O (0.03 mmol) in benzene was added dropwise to 10 mL of (XI) (0.03 mmol) in benzene, and stirred at room temperature for 30 min. Remove the solvent, dissolve and filter with a small amount of ether, then use cyclohexane as a precipitant to precipitate a solid, wash and dry to obtain 27 mg of a yellow powder of the complex [Eu(tta) ₃ XI].

The obtained complex is subjected to mass spectrometry analysis, mass spectrometry (MALDI-TOF MS) analysis records the complex molecular ion peak M/Z=1246; Elemental analysis value (mass percentage): C, 46.20% (46.27%); H , 3.44% (3.40%); N, 8.83% (8.99%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XVII.

According to the method described in Example 2, with the dimethyl sulfoxide solution of DCM as a reference (Φ=0.8), under the irradiation of excitation light with a wavelength of 411nm, the fluorescence quantum yield of europium ions of the complex of formula XVII is measured to be 0.51 (The detection wavelength is 614nm), and the fluorescence excitation window can be extended to 455nm.

    (式XVII)

(Formula XVII)

Example 9, 2-(N-methyl-N-ethyl-2-methylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1 , 3,5-triazine (C ₂₃ H ₂ 8N ₈ , formula XII, that is, in formula I, R ₁ ＝H ₅ C ₂ -, R ₂ ＝R 3 ＝R ₄ ＝R ₅ ＝ _{R 6 ＝} R ₇ ＝H ₃ C-, R ₈ ＝H) Synthesis of Photosensitive Ligand Molecular Compound

According to the synthesis method of Example 1, replace N, N-diethyl-2,6-dimethyl-p-bromoaniline with N-methyl-N-ethyl-2-methyl-p-bromoaniline, and synthesize 2-(N-methyl-N-ethyl-2-methylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5 - Triazine compound 68 mg.

The obtained compound is subjected to mass spectrometry analysis, and mass spectrometry (EI MS) analysis records the above-mentioned synthetic compound molecular ion peak M/Z=416; Elemental analysis value (mass percentage composition): C, 66.52% (66.32%); H, 6.74% (6.78%); N, 26.79% (26.90%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XII.

    (式XII)

(Formula XII)

Example 10, Synthesis of Europium Complex Eu(tta) ₃ XII (EuC ₄₇ H ₄₀ N ₈ F ₉ O ₆ S ₃ )

Under argon protection, 10 mL of Eu(tta) ₃ ·3H ₂ O (0.03 mmol) in ether was added dropwise to 10 mL of (XII) (0.03 mmol) in ether, and stirred at room temperature for 30 min. Concentrate, then use petroleum ether as a precipitating agent to precipitate a solid, wash and dry to obtain 28 mg of a yellow powder of the complex [Eu(tta) ₃ XII].

The obtained complex is subjected to mass spectrometry analysis, mass spectrometry (MALDI-TOF MS) analysis records the molecular ion peak M/Z=1232; Elemental analysis value (mass percentage content): C, 45.61% (45.82%); H, 3.29 % (3.27%); N, 8.99% (9.10%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XVIII.

According to the method described in Example 2, with the dimethylsulfoxide solution of DCM as a reference (Φ=0.8), under the irradiation of excitation light with a wavelength of 411nm, the fluorescence quantum yield of europium ions of the complex of formula XVIII is measured to be 0.40 (The detection wavelength is 614nm), and the fluorescence excitation window is extended to 450nm.

    (式XVIII)

(Formula XVIII)

Example 11, 2-(N,N-diethyl-2,6-dimethylanilino-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-tri Oxyzine, (C ₂₁ H ₂₄ N ₈ , formula XIII, namely R ₁ =R ₂ =H ₃ CH ₂ C- in formula I, R ₃ =R ₄ =R ₅ =R ₆ =H, R ₇ =R ₈ = Synthesis of H ₃ C-) Organic Photosensitive Molecular Compounds

According to the synthesis method of Example 1, pyrazole was used instead of 3,5-dimethylpyrazole described in Example 1 to obtain 40 mg of the compound of formula XIII.

The obtained compound is subjected to mass spectrometry analysis, and mass spectrometry (EI MS) analysis records molecular ion peak M/Z=388; Elemental analysis value (mass percentage composition): C, 64.80% (64.93%); H, 6.27% (6.23% %); N, 28.91% (28.85%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XIII.

　　　　(式XIII)

(Formula XIII)

Example 12, Synthesis of Europium Complex [Eu(tta) ₃ XIII] (EuC ₄₅ H ₃₆ N ₈ F ₉ O ₆ S ₃ )

22 mg of the complex [Eu(tta) ₃ XIII] was synthesized according to the synthesis method of Example 2, using the compound represented by the formula XIII as a ligand.

The obtained complex was subjected to mass spectrometry analysis, and the results showed that the mass spectrometry (MALDI-TOF MS) analysis measured the molecular ion peak M/Z=1204; elemental analysis value (mass percentage): C, 44.71% (44.89%); H, 3.00% (3.01%); N, 9.38% (9.31%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XIX.

    (式XIX)

(Formula XIX)

Example 13, 2-(N-methyl-N-butyl-2,6-dimethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl) )-1,3,5-triazine (C ₂₆ H ₃₄ N ₈ , formula XX, that is, in formula I, R ₁ =H ₃ C-, R ₂ =nH ₉ C ₄ -, R ₃ =R ₄ =R ₅ ＝R ₆ ＝R ₇ ＝R ₈ ＝H ₃ C-) Synthesis of photosensitive ligand molecule compound

According to the synthesis method of Example 1, replace N, N-diethyl-2,6-dimethyl-p-bromoaniline with N-methyl-N-butyl-2,6-dimethyl-p-iodoaniline , synthesized to obtain 2-(N-methyl-N-butyl-2,6-dimethylaniline-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl) - 39 mg of 1,3,5-triazine compound.

The obtained compound is subjected to mass spectrometry analysis, and mass spectrometry (EI MS) analysis records molecular ion peak M/Z=458; Elemental analysis value (mass percentage composition): C, 67.96% (68.09%); H, 7.43% (7.47 %); N, 24.55% (24.43%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the product structure is shown in formula XX.

    (式XX)

(Formula XX)

Example 14, Synthesis of Europium Complex [Eu(tta) ₃ XX] (EuC ₅₀ H ₄₆ N ₈ F ₉ O ₆ S ₃ )

Using the compound of formula XX as a ligand, 26 mg of the complex was synthesized according to the synthesis method of Example 2.

The obtained complex is subjected to mass spectrometry analysis, mass spectrometry (MALDI-TOF MS) analysis records the molecular ion peak M/Z=1274; Elemental analysis value (mass percentage): C, 47.25% (47.13%); H, 3.57 % (3.64%); N, 8.72% (8.79%), the theoretical value in brackets; nuclear magnetic resonance spectrum analysis shows that the structure of the product is shown in formula XXI.

According to the method described in Example 2, with the dimethyl sulfoxide solution of DCM as a reference (Φ=0.8), under the irradiation of excitation light with a wavelength of 411nm, the fluorescence quantum yield of europium ions of the complex of formula XV is 0.53 (The detection wavelength is 614nm). The fluorescence excitation window of the compound of formula XV is extended to 455nm.

    (式XXI)

(Formula XXI)

The results in Figures 1-2 show that the complex XIV provided by the present invention has a wider two-photon excitation window in the long-wave direction than the reported europium complex [Eu(tta) ₃ dpbt]. The type VI complex compound provided by the invention has excellent visible light-sensitized luminescent ability, its europium ion fluorescence quantum yield is greater than 0.40, and its excitation window extends above 450nm.

The novel rare earth complex provided by the present invention has a wide excitation window, a large two-photon absorption cross section and/or a high fluorescence quantum yield of rare earth ions, and can be used to synthesize functional materials such as bioluminescent probes with excellent luminescent properties.

Claims (10)

1. A photosensitive organic molecular compound, the structure of which is shown in formula I:

(Formula I) Wherein, in formula I, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₃ =R ₄ =R ₅ =R ₆ is methyl or H, R ₇ is methyl, R ₈ is methyl or H. 2. The photosensitive organic molecular compound according to claim 1, characterized in that: in the formula I, R ₁ and R ₂ are ethyl groups, R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ are all For methyl. 3. A photosensitive luminescent europium complex, the structure of which is shown in formula VI:

(Formula VI) Wherein, in formula VI, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₃ =R ₄ =R ₅ =R ₆ is methyl or H, R ₇ is methyl, R ₈ is methyl or H. 4. The europium complex according to claim 3, characterized in that: in the formula VI, R ₁ and R ₂ are ethyl groups, R ₃ =R ₄ =R ₅ =R ₆ =R ₇ =R ₈ is methyl base. 5. The method for synthesizing the photosensitive organic molecular compound according to claim 1 or 2, comprising the following steps: 1) To N, N-dialkylamino-2,6-dimethylphenyllithium or to N, N-dialkylamino-2-methylphenyllithium and cyanuric chloride to prepare Obtain the substituted triazine compound shown in formula IV; 2) reacting the substituted triazine compound obtained in step 1) with the pyrazole anion or substituted pyrazole anion shown in formula V to prepare the photosensitive organic molecular compound shown in formula I;

(Formula IV) (Formula V) Wherein, in formula IV, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₇ is methyl, and R ₈ is methyl or H; in formula V, R ₃ =R ₅ are both methyl or H. 6. The method according to claim 5, characterized in that: the p-N,N-dialkylamino-2,6-dimethylphenyllithium or p-N,N-dialkylamino- 2-Methylphenyllithium is the product obtained after reacting N,N-dialkyl p-halogenated anilines shown in formula III with alkyllithium; (Formula III) Wherein, in formula III, R ₁ and R ₂ are alkyl groups with 1-4 carbon atoms, R ₇ is methyl, R ₈ is methyl or H, and X is I, Br or Cl. 7. The method according to claim 6, characterized in that the number of carbon atoms in the alkyllithium is 1-8. 8. The method according to claim 7, characterized in that: in the step 2), the molar ratio of the compound shown in formula IV to the pyrazole anion or substituted pyrazole anion shown in formula V is 1:2— 10. 9. The method according to claim 8, characterized in that: in the step 2), it also includes reacting the reaction product of the substituted triazine compound with the pyrazole anion or substituted pyrazole anion shown in formula V using Chromatographic column separation, and then recrystallization to obtain the purified photosensitive organic molecular compound represented by formula I. 10. The preparation method of the europium complex according to claim 3 or 4, which is to react the photosensitive organic molecular compound according to claim 1 or 2 with the compound represented by formula XXII to obtain the europium complex;

(Formula XXII) In the method, it also includes purifying the europium complex obtained by the reaction, and the purification method is to add a poor solvent to the complex solution to precipitate the complex; the poor solvent is selected from petroleum ether, n-hexane and One or more of cyclohexane.

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