A fluorinated triphenylmethyl radical compound, its preparation method and application

Abstract

This invention discloses a fluorinated triphenylmethyl radical compound, its preparation method, and its applications. The invention retains the chemical structure of the triphenylmethyl radical and connects it to a fluorinated alkyl chain in a relatively stable manner. Because the fluorinated triphenylmethyl radical compound retains its core radical structure, it can be applied in melt dynamic nuclear polarization technology to achieve efficient polarization transfer from free electron spin to specific nuclear spins in the target sample, thereby increasing the intensity of the NMR signal. The carboxylic acid functional group can be rationally modified into ester or amide bonds without affecting its role as an electron spin provider. The fluorinated triphenylmethyl radical compound synthesized in this invention has fluorocarbon phase properties. Solid-phase extraction using polytetrafluoroethylene micropowder or fluorosilicone allows for rapid and complete separation of the fluorinated triphenylmethyl radical compound from the polarized sample, solving a key problem in current melt dynamic nuclear polarization technology (rapid removal of free radicals from the sample).

Description

Technical Field

[0001] This invention belongs to the field of nuclear magnetic resonance technology, specifically a fluorinated triphenylmethyl free radical compound, its preparation method, and its application. Background Technology

[0002] Nuclear magnetic resonance (NMR) technology, operating in the radio frequency band, possesses unique advantages such as non-destructive detection, excellent tissue penetration, and low energy absorption, playing a significant role in fields such as biochemistry and materials science. However, the core challenge facing this technology lies in its inherent low sensitivity, a limitation that severely restricts the detection of nuclei with low gyromagnetic ratios or low natural abundance.

[0003] To overcome this limitation, the scientific community has mainly focused on two technical approaches: one is instrument-based signal enhancement strategies, including high-intensity magnets and cryogenic probes. While these methods have achieved significant results, their development has plateaued in recent years. The other is breakthroughs in hyperpolarization technology, among which dynamic nuclear polarization (DNP) technology has attracted considerable attention due to its superior enhancement effect. The core mechanism of DNP technology lies in the high polarization properties of unpaired electrons (free radicals), achieving polarization transfer through electron-nuclear spin interactions. This technology requires three key steps: first, polarizing the polarizing agent and sample under ultra-low temperatures (typically 1-2K) and strong magnetic fields (>3T); then, exciting electron paramagnetic resonance through microwave irradiation; and finally, transferring the polarized sample to a conventional NMR / MRI system through rapid melting.

[0004] Currently, dynamic nuclear polarization polarizers are mainly divided into: 1) Niacinyl compounds: such as bTbK, taking TEKPol as an example [Journal of the American Chemical Society, 2004, 126: 10844-10845]. Such polarizers have a rigid spirocyclic skeleton, which connects niacin radicals together in a specific direction and at a fixed distance, making it more efficient to meet the necessary polarization transfer conditions. However, due to the hydrophobicity of TEKPol molecules, its application is limited to a certain extent. Similar molecules to AMUPol [Angewandte Chemie-International Edition, 2013, 52: 10858-10861] designed by introducing hydrophilic side chains have good hydrophilicity. However, due to the wide EPR spectrum of niacinyl compounds, their application in high magnetic fields is limited; 2) Triphenylmethyl radicals and BDPA: polarizer molecules have the characteristics of narrow EPR spectrum, stable structure and easy chemical modification. To further improve the stability of polarizers, long-chain alkyl groups or functionalized side chains are usually introduced into their molecular structure to regulate the spatial distribution and chemical environment of the polarization center in the system. For example, DTR1 [Chemical Communications, 2008, 4336-4338] has a highly symmetrical dendritic structure to achieve covalent encapsulation and improve the stability of the polarizer; 3) Hybrid diradicals: By combining narrow-linewidth radicals (such as Trityl) and nitryl radicals, they exhibit excellent performance in high-field DNPs. Their advantages are: the narrow-linewidth component is easy to excite with microwaves, and the polarization can be efficiently transferred to the nitryl group through spin coupling, and finally transferred to the target nucleus spin. Compared with traditional nitryl diradicals, this design significantly improves the polarization efficiency under high fields.

[0005] Despite significant progress in strategies to enhance polarizer performance, efficiently removing polarizers after polarization transfer remains a key challenge. This issue is particularly prominent in in vivo bioimaging applications: polarizer free radicals not only accelerate NMR signal decay but may also cause toxic side effects on organisms due to their residue in the sample, such as inducing cell damage or other adverse reactions. Therefore, developing methods for rapidly separating free radicals from polarized samples to reduce signal attenuation and avoid in vivo toxicity is a core challenge that urgently needs to be addressed in current dynamic nuclear polarization (DNP) technology. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a fluorinated triphenylmethyl radical compound, its preparation method, and its application. This invention rationally covalently links the triphenylmethyl radical and the fluorinated alkyl chain Rf to prepare a fluorinated triphenylmethyl radical compound. Using this compound as a DNP polarizer not only achieves efficient polarization transfer from free electrons to the target nuclear spin but also solves the problem of separating the polarized sample from the radical, thus promoting the application of DNP technology in multiple fields such as materials science, drug development, and life science research.

[0007] The technical solution adopted to achieve the above-mentioned objectives of this invention is as follows:

[0008] A fluorinated triphenylmethyl radical compound, the molecular structure of which consists of two parts: the first part is a triphenylmethyl radical, and the second part is a fluorinated alkyl chain Rf. The general structural formula of the compound is as follows:

[0009] Where k is an integer between 1 and 3, preferably k = 1;

[0010] When k=1, the structural formula of the fluorinated triphenylmethyl radical compound (abbreviated as FA) is as follows:

[0011] ;

[0012] When k=2, the structural formula of the fluorinated triphenylmethyl radical compound (abbreviated as FB) is as follows:

[0013] ;

[0014] When k=3, the structural formula of the fluorinated triphenylmethyl radical compound (abbreviated as FC) is as follows:

[0015] ;

[0016] Ra is selected from CH3, CD3, CH2CH2OH, CH2OCH2CH2OH, or two Ra atoms on the same carbon atom are linked together to form the following ring structure.

[0017] , where m is a positive integer and m is not greater than 20;

[0018] Rf is selected from O(CH2) m (CF2) n CF3, O(CH2CH2O) x (CH2) y OC(CF3)3, NH(CH2) m (CF2) n CF3, NH(CH2CH2O)x (CH2) y OC(CF3)3, where m and n are integers between 1 and 10, x and y are integers between 0 and 20, and F is fluorine-19.

[0019] Furthermore, the fluorine content in the compound is 5-65%, preferably 20%.

[0020] A method for preparing a fluorinated triphenylmethyl free radical compound includes the following steps:

[0021] In the presence of a base, a triphenylmethyl radical compound or its salt undergoes a nucleophilic substitution reaction with an activated fluorinated alkyl compound LGRf to yield a fluorinated triphenylmethyl radical compound constructed via an ester bond, as shown in the following reaction formula:

[0022] ,

[0023] Among them, the activated fluorinated alkyl compound LGRf is a compound composed of an activating group LG and a fluorinated alkyl chain Rf.

[0024] Furthermore, the activating group LG is selected from p-toluenesulfonyl, methanesulfonyl, trifluoromethanesulfonyl, halogen and succinimide ester, preferably p-toluenesulfonyl.

[0025] Furthermore, the salt of the triphenylmethyl radical compound is its potassium salt or its sodium salt, and the molar ratio of the triphenylmethyl radical compound or its salt, the fluorinated alkyl compound LGRf and the base is 1.0:1.0-8.0:2.0-4.0.

[0026] Furthermore, in the nucleophilic substitution reaction, the reaction solvent is at least one selected from N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; preferably, the reaction solvent is N,N-dimethylformamide. The base is selected from at least one selected from N,N-diisopropylethylamine, triethylamine, potassium carbonate, and sodium carbonate; preferably, the base is N,N-diisopropylethylamine. The reaction temperature is 0-100°C; preferably, the reaction temperature is 50°C.

[0027] Application of a fluorinated triphenylmethyl radical compound in the preparation of DNP polarizing agents.

[0028] Furthermore, the rapid separation method for the fluorinated triphenylmethyl radical compound is as follows:

[0029] Using polytetrafluoroethylene micropowder or fluorosilicone as solid-phase filler, solid-phase extraction is performed on the mixture of the fluorinated triphenylmethyl free radical compound and the polarized sample to achieve rapid separation of the fluorinated triphenylmethyl free radical compound and the polarized sample.

[0030] Furthermore, the average particle size of the polytetrafluoroethylene (PTFE) micropowder is 1-1000 μm, preferably 200 μm. The average particle size of the fluorosilicone is 1-100 μm, preferably 40-60 μm.

[0031] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0032] The fluorinated triphenylmethyl radical compound of this invention retains the chemical structure of the triphenylmethyl radical and connects to the fluorinated alkyl chain in a relatively stable manner. Because the fluorinated triphenylmethyl radical compound retains its core radical structure, it can be used in melt dynamic nuclear polarization technology to achieve efficient polarization transfer from free electron spin to specific nuclear spins in the target sample. This greatly improves the intensity of the NMR signal, thereby enhancing detection sensitivity. Furthermore, the carboxylic acid functional group can be rationally modified into ester or amide bonds without affecting its role as an electron spin donor. In addition, the fluorinated group in the fluorinated triphenylmethyl radical compound has multiple methylene groups between it and the radical structure, thus avoiding the influence of the electron-withdrawing ability of the fluorinated group on the electronic effects of the radical structure.

[0033] This invention utilizes triphenylmethyl radicals as electron spin mediators and fluorinated alkyl groups as tag molecules, giving it unique fluorocarbon phase properties. The fluorocarbon phase possesses unique hydrophobic and oleophobic properties and selective affinity for fluorinated compounds, enabling efficient purification of these compounds. It offers advantages such as ease of operation, high selectivity, and structure preservation. Using this method, fluorinated radical compounds can be efficiently separated from polarized samples containing non-fluorinated substances, achieving the goal of scavenging free radicals in polarized samples.

[0034] The fluorinated triphenylmethyl free radical compound synthesized in this invention has fluorocarbon phase properties. Solid-phase extraction using polytetrafluoroethylene micropowder or fluorosilica gel enables rapid and complete separation of the fluorinated triphenylmethyl free radical compound from the polarized sample. The separation process is time-efficient and efficient, eliminating the need for cumbersome chromatographic column purification or the addition of chemical reagents. This greatly simplifies the operation of removing free radical compounds, reduces the loss of sample polarizability, helps maintain sample polarizability, enhances the sensitivity of nuclear magnetic resonance, and solves the key problem of current fusion dynamic nuclear polarization technology (rapid removal of free radicals from the sample).

[0035] The fluorinated triphenylmethyl free radical compound synthesized in this invention can be completely separated from polarized samples, reducing the impact of free radicals on subsequent experiments, especially the toxic side effects on biological systems, and providing an efficient and safe sample preparation method for in vivo molecular imaging in the biomedical field.

[0036] The fluorinated triphenylmethyl radical compound of the present invention is suitable as a polarizing agent for dynamic nuclear polarization experiments due to its narrow EPR spectrum and good water solubility.

[0037] The synthetic route of this invention is highly efficient, the reaction conditions are mild, and it does not affect the stability of free radicals. Attached Figure Description

[0038] Figure 1 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 1a prepared in Example 1 is shown.

[0039] Figure 2 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 1b prepared in Example 1 is shown.

[0040] Figure 3 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 1c prepared in Example 1 is shown.

[0041] Figure 4 The fluorinated triphenylmethyl radical compound 1a prepared in Example 1 19 F NMR spectrum.

[0042] Figure 5 The fluorinated triphenylmethyl radical compound 1b prepared in Example 1 19 F NMR spectrum.

[0043] Figure 6 The fluorinated triphenylmethyl radical compound 1c prepared in Example 1 19 F NMR spectrum.

[0044] Figure 7 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 2a prepared in Example 2 is shown.

[0045] Figure 8 The HPLC spectrum of fluorinated triphenylmethyl free radical compound 2a prepared in Example 2 is shown.

[0046] Figure 9 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 2b prepared in Example 2 is shown.

[0047] Figure 10 The HPLC spectrum of fluorinated triphenylmethyl radical compound 2b prepared in Example 2 is shown.

[0048] Figure 11 The MALDI-TOF-MS spectrum of the fluorinated triphenylmethyl radical compound 2c prepared in Example 2 is shown.

[0049] Figure 12 The HPLC spectrum of fluorinated triphenylmethyl free radical compound 2c prepared in Example 2 is shown.

[0050] Figure 13 The fluorinated triphenylmethyl radical compound 2a prepared in Example 1 19 F NMR spectrum.

[0051] Figure 14 The fluorinated triphenylmethyl radical compound 2b prepared in Example 1 19 F NMR spectrum.

[0052] Figure 15 The fluorinated triphenylmethyl radical compound 2c prepared in Example 1 19 F NMR spectrum.

[0053] Figure 16 The EPR spectra of the fluorinated triphenylmethyl radical compounds 2a, 2b, and 2c prepared in Example 2 are shown.

[0054] Figure 17 This is an HPLC chromatogram of a mixture of free radical OX063 and sodium pyruvate before and after solid-phase extraction.

[0055] Figure 18 The image shows the HPLC chromatograms of the mixture of fluorinated triphenylmethyl radical compound 2a prepared in Example 2 and sodium pyruvate before and after solid-phase extraction. Detailed Implementation

[0056] To facilitate understanding and implementation of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to embodiments. It should be understood that the embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0057]

[0058] The free radical CT-03 (commercially available, CAS No.: 372515-55-4, 9.97 mg, 0.01 mmol), 3-perfluorooctylpropyl p-toluenesulfonate (CAS No.: 228570-07-8; 6.32 mg, 0.01 mmol) and N,N-diisopropylethylamine (2.58 mg, 0.02 mmol) were dissolved in N,N-dimethylformamide (1 mL), and then the mixture was stirred at 50 °C for 24 h. After the reaction was complete, the solvent was removed by vacuum distillation of the resulting mixture. The residue was purified by semi-preparative high-performance liquid chromatography (HPLC parameters: column: Shimadzu-Shim-pack GIS, 5 µm C18, 30*250 mm; mobile phase: aqueous phase: water containing 0.1% v / v trifluoroacetic acid, organic phase: methanol containing 0.1% v / v trifluoroacetic acid) to obtain fluorinated triphenylmethyl radical compound 1a (3.68 mg, yield 25%), fluorinated triphenylmethyl radical compound 1b (0.31 mg, yield 1.3%), and fluorinated triphenylmethyl radical compound 1c (0.68 mg, yield 2.8%).

[0059] The MALDI-TOF-MS spectra of fluorinated triphenylmethyl radical compounds 1a-1c are shown below. Figure 1-3 As shown.

[0060] 1a: MALDI-TOF-MS m / z: [M] - calcd for C 51 H 44 F 17 O6S 12 • - , 1457.94; found,1458.09.

[0061] 1b: MALDI-TOF-MS m / z: [M] - calcd for C 62 H 49 F 34 O6S 12 • - , 1918.96; found, 1920.26.

[0062] 1c: MALDI-TOF-MS m / z: [M] - calcd for C 73 H 54 F 51 O6S 12 • - , 2377.98; found,2377.71.

[0063] Fluorinated triphenylmethyl radical compounds 1a-1c 19 F NMR spectrum as shown Figure 4-6 As shown.

[0064] 1a: 19 FNMR (471 MHz, CD3OD) δ -81.87 (t, J = 9.9 Hz), -114.73– -115.30(m), -122.02 – -122.28 (m), -122.30– -122.59 (m), -123.08– -123.44 (m), -123.91– -124.26 (m), -126.64– -127.01(m).

[0065] 1b: 19 FNMR (471 MHz, CD3OD) δ-81.89 (t, J = 9.9 Hz), -114.80 – -115.28(m), -122.01– -122.30 (m), -122.31– -122.66 (m), -123.12– -123.48 (m), -123.95– -124.30 (m), -126.71– -126.98 (m).

[0066] 1c: 19 FNMR (471 MHz, CDCl3) δ-83.93 (t, J = 10.0 Hz), -117.32– -117.91(m), -124.67 – -124.99 (m), -124.99– -125.37 (m), -125.74– -126.11 (m), -126.53– -127.01 (m), -129.09– -129.50 (m).

[0067] Example 2

[0068]

[0069] Free radical OX063 (commercially available, CAS No.: 734519-63-2, 95.2 mg, 0.07 mmol) was dissolved in 7 mL of N,N-dimethylformamide, followed by the addition of N,N-diisopropylethylamine (18.06 mg, 0.14 mmol) and 3-perfluorooctylpropyl p-toluenesulfonate (66.36 mg, 0.105 mmol), and then the mixture was stirred at 5 °C for 24 h. After the reaction was complete, the solvent was removed by vacuum distillation of the resulting mixture. The residue was purified by semi-preparative high-performance liquid chromatography (HPLC parameters: column: Shimadzu-Shim-pack GIS, 5 µm C18, 30*250 mm; mobile phase: aqueous phase: water containing 0.1% v / v trifluoroacetic acid, organic phase: methanol containing 0.1% v / v trifluoroacetic acid) to obtain fluorinated triphenylmethyl radical compound 2a (38 mg, yield 27.6%), fluorinated triphenylmethyl radical compound 2b (34.6 mg, yield 21.7%), and fluorinated triphenylmethyl radical compound 2c (12.0 mg, yield 6.3%).

[0070] The MALDI-TOF-MS spectra of fluorinated triphenylmethyl radical compounds 2a-2c are shown below. Figure 7 , Figure 9 and Figure 11 As shown.

[0071] 2a: MALDI-TOF-MS m / z: [M] - calcd for C 63 H 67 F 17 O 18 S 12 • - , 1818.07, found,1818.180.

[0072] 2b: MALDI-TOF-MS m / z: [M] - calcd for C 74 H 72 F 34 O 18 S 12 • - , 2278.08, found,2277.974.

[0073] 2c: MALDI-TOF-MS m / z: [M] - calcd for C 85 H 77 F 51 O 18 S 12• - , 2738.09, found,2737.652.

[0074] The HPLC spectra of fluorinated triphenylmethyl radical compounds 2a-2c are as follows: Figure 8 , Figure 10 and Figure 12 As shown.

[0075] Fluorinated triphenylmethyl radical compounds 2a-2c 19 F NMR spectrum as shown Figure 13-15 As shown.

[0076] 2a: 19 FNMR (471 MHz, CD3OD) δ-81.91 (t, J = 10.0 Hz), -114.49– -115.19(m), -122.02– -122.27 (m), -122.28– -122.65 (m), -123.15– -123.44 (m), -123.55– -124.01 (m), -126.71– -127.04(m).

[0077] 2b: 19 FNMR (471 MHz, CD3OD) δ-81.91 (t, J = 10.1 Hz), -114.44– -115.29(m), -122.02– -122.28 (m), -122.28– -122.69 (m), -123.15– -123.48 (m), -123.53– -124.04 (m), -126.72– -127.11(m).

[0078] 2c: 19 FNMR (471 MHz, CD3OD) δ -81.90 (t, J = 10.1 Hz), -114.51– -115.20(m), -122.03– -122.27 (m), -122.27 – -122.63 (m), -123.16– -123.43 (m), -123.59– -123.96 (m), -126.73– -127.02 (m).

[0079] Example 3

[0080] 1. A solvent was prepared by mixing equal volumes of degassed PBS buffer (10 mM, pH = 7.4) and ethanol. Fluorotriphenylmethyl radical compounds 2a, 2b, and 2c were dissolved in the solvent to obtain radical solutions A1, A2, and A3, respectively.

[0081] 2. Free radical solutions A1, A2, and A3 were placed into sample tubes, respectively. ESR spectra of fluorinated triphenylmethyl free radical compounds 2a, 2b, and 2c were acquired using an electron paramagnetic resonance (EPR) spectrometer. The EPR spectrometer parameters were set as follows: microwave power 0.15 mW; modulation amplitude 7 mT; modulation frequency 100 kHz; scan width 0.5 mT; scan time 30 s; conversion time 30.00 ms; number of sampling points 2048.

[0082] 3. The collected EPR spectra of fluorinated triphenylmethyl radical compounds 2a-2c are as follows: Figure 16 As shown, by Figure 16 It can be seen that the EPR spectra of fluorinated triphenylmethyl radical compounds 2a-2c all show narrow peaks, indicating that fluorinated triphenylmethyl radical compounds 2a-2c have good electronic paramagnetic uniformity and structural stability, and are suitable as polarizing agents for dynamic nuclear polarization experiments.

[0083] Example 4

[0084] 1. A mixed solvent was obtained by mixing glycerol and water at a volume ratio of 6:4. Fluorinated triphenylmethyl free radical compound 2a and sodium pyruvate were dissolved in the mixed solvent to obtain mixed solution B1, in which the concentration of 2a was 15 mM and the concentration of sodium pyruvate was 0.76 M. Free radical OX063 and sodium pyruvate were dissolved in the mixed solvent to obtain mixed solution B2, in which the concentration of free radical OX063 was 15 mM and the concentration of sodium pyruvate was 0.76 M.

[0085] 2. Add 1.5 mL of pure water to mixed solution B1 and mixed solution B2 respectively to obtain sample solution C1 and sample solution C2. Take 100 µL of sample solution C1 and sample solution C2 respectively for HPLC analysis.

[0086] 3. Solid-phase extraction was performed on sample solution C1, and HPLC analysis was performed on the extract D1.

[0087] The specific procedure for solid-phase extraction (SPE) is as follows: 2 g of PTFE micropowder (average particle size 200 µm) is loaded into an empty SPE column. The resulting SPE column is first rinsed with 10 mL of methanol, then rinsed with 20 mL of water, and then dried with nitrogen. Sample solution C1 is added to the SPE column, and extract D1 is collected.

[0088] HPLC conditions:

[0089] Detector: Shanghai Tongwei UM5800 ELSD evaporative light scattering detector;

[0090] Chromatographic column: Shimadzu-Shim-pack GIS, 5 µm C18, 4.6*250 mm;

[0091] Flow rate: 0.8 mL / min;

[0092] The mobile phase is a mixture of an organic phase and an aqueous phase. The aqueous phase is water containing 0.1% v / v trifluoroacetic acid; the organic phase is methanol containing 0.1% v / v trifluoroacetic acid.

[0093] The conditions for gradient elution are:

[0094] First stage: Elution time is 0-10 min, with the organic phase volume content being 20%;

[0095] Second stage: Elution time is 10-15 min, during which the volume content of the organic phase increases linearly from 20% to 98%;

[0096] The third stage: elution time is 15-40 min, with the organic phase volume content being 98%;

[0097] Fourth stage: Elution time is 40-45 min, during which the volume content of the organic phase decreases linearly from 98% to 20%;

[0098] Fifth stage: Elution time is 45-60 min, with the organic phase volume content being 20%.

[0099] 4. Process sample solution C2 according to the method in step 3.

[0100] 5. The HPLC chromatograms of sample solution C1 containing fluorinated triphenylmethyl radical compound 2a and sodium pyruvate before and after solid-phase extraction are shown below. Figure 18 As shown, the HPLC chromatograms of sample solution C2 containing free radical OX063 and sodium pyruvate before and after solid-phase extraction are as follows. Figure 17 As shown, comparison Figure 17 and Figure 18 It was found that solid-phase extraction based on PTFE micropowder failed to separate the free radical OX063 in sample solution C2, but it could efficiently separate the free radical fluorotriphenylmethyl free radical compound 2a in sample solution C1. The purified raffinate contained only sodium pyruvate. This indicates that solid-phase extraction can rapidly and completely separate fluorotriphenylmethyl free radical compounds from polarized samples, achieving rapid removal of free radicals.

Claims

1. A fluorinated triphenylmethyl radical compound, characterized in that: The molecular structure of the compound consists of two parts: the first part is a triphenylmethyl radical, and the second part is a fluorinated alkyl chain Rf. The general structural formula of the compound is as follows: ； Where k is an integer between 1 and 2, and Ra is selected from CH3, CD3, CH2CH2OH, and CH2OCH2CH2OH; Rf is selected from O(CH2). m (CF2) n CF3, where m and n are integers between 1 and 10, and F stands for Fluorine-19.

2. The fluorinated triphenylmethyl radical compound according to claim 1, characterized in that: The fluorine content in the fluorinated triphenylmethyl free radical compound is 5-65%.

3. A method for preparing the fluorinated triphenylmethyl radical compound according to any one of claims 1-2, characterized in that... Includes the following steps: In the presence of a base, a triphenylmethyl radical compound or its salt undergoes a nucleophilic substitution reaction with an activated fluorinated alkyl compound LGRf to yield a fluorinated triphenylmethyl radical compound constructed via an ester bond, as shown in the following reaction formula: ； Among them, the activated fluorinated alkyl compound LGRf is a compound composed of an activating group LG and a fluorinated alkyl chain Rf.

4. The method for preparing the fluorinated triphenylmethyl free radical compound according to claim 3, characterized in that: The activating group LG is selected from one of p-toluenesulfonyl, methanesulfonyl, trifluoromethanesulfonyl, halogen, and succinimide ester.

5. The method for preparing the fluorinated triphenylmethyl free radical compound according to claim 3, characterized in that: The salt of the triphenylmethyl radical compound is its potassium salt or its sodium salt, and the molar ratio of the triphenylmethyl radical compound or its salt, the fluorinated alkyl compound LGRf and the base is 1.0:1.0-8.0:2.0-4.

0.

6. The method for preparing the fluorinated triphenylmethyl free radical compound according to claim 3, characterized in that: In the nucleophilic substitution reaction, the reaction solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide, the base is selected from at least one of N,N-diisopropylethylamine, triethylamine, potassium carbonate and sodium carbonate, and the reaction temperature is 0-100℃.

7. The use of a fluorinated triphenylmethyl radical compound according to any one of claims 1-2 in the preparation of a DNP polarizer.

8. The application of the fluorinated triphenylmethyl radical compound according to claim 7, characterized in that... The rapid separation method for the fluorinated triphenylmethyl radical compound is as follows: Using polytetrafluoroethylene micropowder or fluorosilicone as solid-phase filler, solid-phase extraction is performed on the mixture of the fluorinated triphenylmethyl free radical compound and the polarized sample to achieve rapid separation of the fluorinated triphenylmethyl free radical compound and the polarized sample.

9. The application of the fluorinated triphenylmethyl radical compound according to claim 8, characterized in that: The average particle size of the polytetrafluoroethylene micro powder is 1-1000 μm, and the average particle size of the fluorosilicone is 1-100 μm.

Images