Allyl luminous free radical material and preparation method thereof

Abstract

The invention provides an allyl light-emitting free radical material and a preparation method thereof, and belongs to the technical field of light-emitting materials. The allyl light-emitting free radical material provided by the invention has a structure as shown in a formula I, a five-membered aromatic ring is introduced to construct an asymmetric triaryl methyl free radical derivative, a steric hindrance effect is used for inhibiting spin delocalization, spinning electrons are promoted to be localized in an allyl core, and therefore an intrinsic luminous allyl free radical core structure unit is constructed; furthermore, an electron donor functional unit is accurately introduced to the periphery of the free radical nucleus, and the electronic structure and the front line molecular orbital energy level of the D-A type free radical are systematically regulated and controlled, so that a novel free radical luminescence system with high fluorescence quantum yield and wide spectrum regulation and control range (700-1100nm) is finally realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-emitting materials, in particular to an allyl light-emitting radical material and a preparation method thereof. BACKGROUND

[0002] Organic radical light-emitting materials have shown certain application prospects in the fields of high-efficiency organic electroluminescent devices (OLED), electrochromic devices, molecular-level quantum information technology carriers, and precise photodynamic therapy probes, etc. due to their unique open-shell electronic structure and photophysical properties. The structural diversity of organic light-emitting monoradical systems is still insufficient, and the reported systems are mainly concentrated in the following categories: TTM / PTM type radicals, heteroanthracenes, and bis-carbazole-substituted triarylmethyl radicals. Developing new monoradical light-emitting cores has always been a problem to be solved in this field.

[0003] Among the currently reported organic light-emitting monoradical materials, TTM and PTM radicals have successfully realized the preparation and application of OLED devices due to their significant photophysical performance advantages, especially higher fluorescence quantum yield. For example: in 2018, the team of Li Feng jointly with the R.H. Friend group experimentally proved that monoradical materials can achieve an internal quantum efficiency (IQE) close to 100%, and the OLEDs of TTM derivatives with different carbazole linkage modes have an EQE of 27% and 17%, respectively. T. Kusamoto team developed a series of pyridine-containing methyl radicals PyBTM, bis-PyTM and trisPyM. Compared with TTM radicals, the introduction of pyridine makes this kind of compounds have lower energy levels, thus showing more excellent air stability; the team of He Zikai reported a bis-carbazole-substituted triarylmethyl radical, which showed a rare near-infrared luminescence feature (1020 nm), but its fluorescence yield was too low to be detected; the team of Li Zhen jointly with the team of Wu Jixin and the team of Li Feng reported a series of stable heteroanthracene monoradicals, which have good light stability. This series of monoradicals have near-infrared emitting fluorescence characteristics, and their OLED devices can exhibit an IQE of nearly 81%, which again proves the potential of radical materials in the field of OLEDs. Therefore, how to prepare new radical units with air stability through molecular design, and then construct radical light-emitting materials with high-efficiency luminescence and spectral controllable characteristics, has become a key scientific problem to be broken through in this field.

[0004] The introduction of donor-acceptor structures containing non-alternating aromatic compounds, the symmetry regulation of molecular orbitals, and the non-bonding connection between donor-acceptor units are particularly important for constructing a free radical light-emitting system with high quantum efficiency and excellent stability. Allyl radicals, as a class of unique three-center three-electron open-shell pi system molecules, have attracted much attention due to their excellent air stability. However, the delocalization of unpaired electrons and low-energy excited states of allyl radicals make their energy release through non-radiative transition, resulting in no luminescence of allyl radicals. SUMMARY

[0005] Therefore, the present application aims to develop a new single radical light-emitting core, and provide an allyl light-emitting radical material and a preparation method thereof.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions.

[0007] In one of the technical solutions of the present application, the allyl light-emitting radical material has the structure shown in Formula I:

[0008]

[0009] wherein · is a free radical single electron;

[0010] R is any one of the following structures:

[0011]

[0012] X is

[0013] In a preferred embodiment of the present application, the allyl light-emitting radical material has the structure shown in Formula a to p:

[0014] In another technical solution of the present application, a preparation method of the above-mentioned allyl light-emitting radical material is provided. When X is , the preparation method of the allyl light-emitting radical material having the structure shown in Formula I comprises the following steps:

[0015] Step 1. Compound 1 is subjected to a Friedel-Crafts alkylation reaction 1 with compound 2 to obtain a Friedel-Crafts alkylation product 1;

[0016] Step 2. The Friedel-Crafts alkylation product 1 is subjected to an oxidation reaction to obtain an oxidation product;

[0017] Step 3. The oxidation product is subjected to a dehydrogenation reaction 1 to obtain the allyl light-emitting radical material;

[0018] The application provides a preparation method of an allyl luminescent free radical material with a structure shown in formula I, and the method comprises the following steps.

[0019] Step S1. Compound 1 is subjected to a Friedel-Crafts alkylation reaction 2 with compound 3, so as to obtain a Friedel-Crafts alkylation product 2;

[0020] Step S2. The Friedel-Crafts alkylation product 2 is subjected to a dehydrogenation reaction 2, so as to obtain the allyl luminescent free radical material;

[0021] The compound 1 has a structural formula as shown in the following formula:

[0022] The compound 2 has a structural formula as shown in the following formula:

[0023] The compound 3 has a structural formula as shown in the following formula:

[0024] In the compound 2 and the compound 3, R is the same as R in the above formula I.

[0025] In a preferred embodiment of the application, in step 1, the catalyst used in the Friedel-Crafts alkylation reaction 1 is aluminum trichloride, the solvent is anhydrous dichloromethane, the molar ratio of compound 1 to compound 2 is 1:(0.9-2), the molar ratio of compound 1 to aluminum trichloride is 1:1, the reaction temperature of the Friedel-Crafts alkylation reaction 1 is room temperature, and the reaction time is 1-3 hours.

[0026] The application does not specially limit the amount of the anhydrous dichloromethane used in the above-mentioned Friedel-Crafts alkylation reaction 1, and a conventional technical means of a person skilled in the art can be selected, for example, 10-20 mL of the solvent is added per 1 mmol of compound 1.

[0027] In the application, after the Friedel-Crafts alkylation reaction 1 is completed, the reaction is quenched with hydrochloric acid, and then the obtained reaction solution is subjected to extraction and purification.

[0028] In a preferred embodiment of the application, in step 2, the oxidant used in the oxidation reaction is peroxotricfluoroacetic acid or m-chloroperbenzoic acid, and other oxidants suitable for the oxidation reaction in the application can also be selected, the solvent is anhydrous dichloromethane, the molar ratio of the Friedel-Crafts alkylation product 1 to the oxidant peroxotricfluoroacetic acid is 1:(10-15), the molar ratio of the Friedel-Crafts alkylation product 1 to the oxidant m-chloroperbenzoic acid is 1:(4-5), the temperature of the oxidation reaction is room temperature, and the reaction time is 12-14 hours.

[0029] The application does not specially limit the amount of the anhydrous dichloromethane used in the above-mentioned oxidation reaction, and a conventional technical means of a person skilled in the art can be selected, for example, 10-20 mL of the solvent is added per 1 mmol of compound 1.

[0030] In the present application, after the oxidation reaction is completed, the reaction is quenched with saturated sodium bisulfite solution, and then the obtained reaction solution is extracted and purified.

[0031] In the preferred embodiment of the present application, in step 3, the base in the dehydrogenation reaction 1 is potassium tert-butoxide, the catalyst is 18-crown-6, the solvent is tetrahydrofuran, and the oxidant is tetrachlorobenzoquinone; the molar ratio of the oxidation product, potassium tert-butoxide, 18-crown-6, and tetrachlorobenzoquinone is 1:8:8:8; the temperature of the dehydrogenation reaction 1 is room temperature, and the reaction time is 12 h.

[0032] The amount of tetrahydrofuran used in the above-mentioned dehydrogenation reaction 1 is not particularly limited and can be selected by using conventional technical means of those skilled in the art, for example, 2-3 mL of solvent is added per 1 μmol of compound 1.

[0033] In the present application, after the dehydrogenation reaction 1 is completed, the reaction is quenched with saturated brine, and then the obtained reaction solution is extracted and purified.

[0034] In the preferred embodiment of the present application, in step S1, the catalyst used in the Friedel-Crafts alkylation reaction 2 is aluminum chloride, and the solvent is anhydrous dichloromethane; the molar ratio of compound 1 to compound 3 is 1:(0.09-0.12); the molar ratio of compound 1 to aluminum chloride is 1:(0.1-0.2); the reaction temperature of the Friedel-Crafts alkylation reaction 2 is room temperature, and the reaction time is 1-3 h.

[0035] The amount of anhydrous dichloromethane used in the above-mentioned Friedel-Crafts alkylation reaction 2 is not particularly limited and can be selected by using conventional technical means of those skilled in the art, for example, 10-20 mL of solvent is added per 1 mmol of compound 1.

[0036] In the present application, after the Friedel-Crafts alkylation reaction 2 is completed, the reaction is quenched with hydrochloric acid, and then the obtained reaction solution is extracted and purified.

[0037] In the preferred embodiment of the present application, in step S2, the base in the dehydrogenation reaction 2 is potassium tert-butoxide, the catalyst is 18-crown-6, the solvent is tetrahydrofuran, and the oxidant is tetrachlorobenzoquinone; the molar ratio of the Friedel-Crafts alkylation product 2, potassium tert-butoxide, 18-crown-6, and tetrachlorobenzoquinone is 1:10:10:10; the temperature of the dehydrogenation reaction 2 is room temperature, and the reaction time is 12 h.

[0038] The amount of the base, catalyst, and solvent used in the above-mentioned dehydrogenation reaction 2 is not particularly limited and can be selected by using conventional technical means of those skilled in the art, for example, 2-3 mL of solvent is added per 1 μmol of compound 1.

[0039] In the present application, after the dehydrogenation reaction 2 is completed, the reaction is quenched with saturated brine, and then the obtained reaction solution is extracted and purified.

[0040] The present application discloses the following technical effects:

[0041] The present application constructs an intrinsic emitting allyl radical core structure unit by introducing a five-membered aromatic ring to construct an asymmetric triarylmethyl radical derivative, using steric hindrance effect to inhibit spin delocalization, and promoting spin electrons to localize in the allyl core.

[0042] The allyl light-emitting radical provided by the present application has good electron transport capacity, and optical information shows that the emission wavelength in n-hexane solution is more than 700 nm.

[0043] The present application prepares a novel radical unit-allyl light-emitting radical with air stability through molecular design; under natural light irradiation, the half-lives of ARS-Ph(a) and ARS-TPA(j) are 5.2 days and 27.5 days respectively, a new single radical light-emitting core is developed and prepared, a radical light-emitting material with high efficiency and spectral adjustable characteristics is constructed, and an organic light-emitting single radical system is expanded.

[0044] The preparation method of the allyl light-emitting radical material provided by the present application has simple process, wide raw material source, high product yield and purity, and shows excellent application prospect in the fields of high-efficiency organic light-emitting diodes (OLEDs), electrochromic devices, and photodynamic therapy probes. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0046] Figure 1 The ultraviolet absorption spectrum and fluorescence emission spectrum of ARS-Ph(a), ARS-TPA(j) and ARC-Ph(l) prepared in Examples 1-3 in solution state are shown in the following figures:

[0047] Figure 2EPR spectrum of ARS-Ph(a) prepared for Example 2 in toluene solution;

[0048] Figure 3 EPR spectrum of ARS-TPA(j) prepared for Example 1 in toluene solution.

[0049] Figure 4 Light stability of ARS-Ph(a) prepared for Example 2 under natural light irradiation.

[0050] Figure 5 Light stability of ARS-TPA(j) prepared for Example 1 under natural light irradiation. DETAILED DESCRIPTION

[0051] Various illustrative embodiments of the present application are described in detail below, with reference to the attached drawings. These embodiments are not intended to be exhaustive or to limit the application to the precise form and details disclosed. Rather, the intent is to cover any modifications and equivalents included within the scope of the application, giving due consideration to the pertinent prior art.

[0052] It should be understood that the terms used herein are for the purpose of describing particular embodiments and are not intended to limit the application. Additionally, for a range of values of a parameter, unless otherwise stated, each intervening value by each intervening value, as well as any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these intervening values can independently be included or excluded in the range, and the fraction of the range between any stated or intervening value may

[0053] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict, the present specification will control.

[0054] Various modifications and changes can be made to the specific embodiments described herein without departing from the scope or spirit of the application. Other embodiments will be apparent to those of ordinary skill in the art from consideration of the specification and practice of the application. The specification and examples given are exemplary only. It is to be understood that the application is not to be limited to the specific embodiments described in this specification.

[0055] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended terms that are intended to mean "including but not limited to".

[0056] In the present application, unless otherwise specified, room temperature means 25±5°C.

[0057] The present application provides an allyl luminescent radical material having a structure shown in Formula I:

[0058]

[0059] wherein • is a radical single electron;

[0060] R is any one of the following structures:

[0061]

[0062] X is

[0063] In the present application, when X is a preparation method of the allyl luminescent radical material having a structure shown in Formula I, the steps are as follows:

[0064]

[0065] Under nitrogen protection, compound 1, aluminum trichloride and anhydrous dichloromethane are added into a reaction bottle respectively, and reacted at 0°C for 20 min. Then compound 2 is added into the reaction bottle, and reacted at room temperature for 1-3 h. The reaction is quenched with hydrochloric acid, the mixture is extracted with dichloromethane for multiple times, dried and purified by column chromatography (petroleum ether:dichloromethane = 5:1 as eluent), and then the crude product is washed with methanol to obtain compound 3.

[0066] Under nitrogen protection, an oxidant, compound 3 and anhydrous dichloromethane are added into a reaction bottle respectively, and reacted at room temperature for 12-14 h. The reaction is quenched with saturated sodium bisulfite solution, the mixture is extracted with dichloromethane for multiple times, dried and purified by column chromatography (petroleum ether:dichloromethane = 1:2 as eluent) to obtain compound 4.

[0067] In a glove box, compound 4, potassium tert-butoxide, 18-crown-6 and anhydrous tetrahydrofuran are added into a reaction bottle respectively, and reacted at room temperature for 5 h. Then tetrachlorobenzoquinone is added, and the reaction is continued at room temperature for 12 h. The reaction is quenched with saturated brine, the mixture is extracted with dichloromethane for multiple times, dried and purified by column chromatography to obtain the target product.

[0068] when X is a preparation method of the allyl luminescent radical material having a structure shown in Formula I, the steps are as follows:

[0069]

[0070] In a 250 mL reaction flask, compound 1 (3.18 mmol), aluminium trichloride (3.18 mmol) and anhydrous dichloromethane (50 mL) were added under nitrogen protection, and reacted at 0°C for 20 min. Compound 2 (3.02 mmol) was added to the reaction flask, and reacted at room temperature for 3 h. The reaction was quenched with 0.1 M hydrochloric acid (50 mL), and the mixture was extracted with dichloromethane. After drying and purification by column chromatography (petroleum ether: dichloromethane = 5:1 as eluent), the crude product was washed with methanol to obtain compound 3 as a light yellow solid (0.29 g, 14%),

[0071] In a glove box, compound 11, potassium tert-butoxide, 18-crown-6 and anhydrous tetrahydrofuran were added to a reaction flask, and reacted at room temperature for 5 h. Tetra-chloro-quinone was added to the reaction flask, and the reaction was continued at room temperature for 12 h. The reaction was quenched with saturated brine, and the mixture was extracted with dichloromethane. After drying and purification by column chromatography (petroleum ether as eluent), compound 12 was obtained as the target product.

[0072] The technical solutions described in the present application are conventional solutions in the art, and the reagents or raw materials used are commercially available or have been disclosed, unless otherwise specified.

[0073] In order to better understand the present application, the content of the present application is further illustrated below in combination with examples, but the content of the present application is not limited to the following examples.

[0074] Example 1

[0075] Synthesis of allyl luminous free radical ARS-TPA (j):

[0076]

[0077] In a 250 mL reaction flask, compound 1 (3.18 mmol), aluminium trichloride (3.18 mmol) and anhydrous dichloromethane (50 mL) were added under nitrogen protection, and reacted at 0°C for 20 min. Compound 2 (3.02 mmol) was added to the reaction flask, and reacted at room temperature for 3 h. The reaction was quenched with 0.1 M hydrochloric acid (50 mL), and the mixture was extracted with dichloromethane. After drying and purification by column chromatography (petroleum ether: dichloromethane = 5:1 as eluent), the crude product was washed with methanol to obtain compound 3 as a light yellow solid (0.29 g, 14%), 1 H NMR (600 MHz, CDC13) δ (ppm): 7.96 (d, 1H), 7.91 (d, 1H), 7.42 (d, 2H), 7.41-7.38 (t, 2H), 7.34 (s, 1H), 7.12-7.09 (m, 6H), 7.07 (d, 4H), 2.33 (s, 6H); 13C NMR (150 MHz, CDC13) δ (ppm): 147.75, 145.33, 140.08, 139.28, 137.78, 137.49, 136.20, 134.32, 133.74, 132.59, 130.01, 129.34, 127.87, 124.42, 123.10, 122.33, 46.01, 20.98; HRMS analysis (APCI): calcd for C 41 H 26 Cl6NS (M-H) - : 773.9923, found: 773.9924 (error: 0.13 ppm).

[0078]

[0079] In a 50 mL reaction vial, m-chloroperoxybenzoic acid (0.94 mmol), compound 3 (0.20 mmol) and anhydrous dichloromethane (5 mL) were added respectively under nitrogen protection, and reacted at room temperature for 14 h. The reaction was quenched with saturated sodium bisulfite solution, the mixture was extracted with dichloromethane for several times, dried and purified by column chromatography (petroleum ether: dichloromethane = 1:2 as eluent) to obtain compound 4 as a yellow solid (52 mg, 32%). 1 H NMR (600 MHz, CDC13) δ (ppm): 7.80 (m, 1H), 7.48-7.50 (m, 2H), 7.41 (d, 1H), 7.34 (d, 2H), 7.15 (s, 1H), 7.12 (d, 4H), 7.10 (d, 2H), 6.98 (d, 4H), 6.95 (s, 1H), 6.89 (d, 2H), 6.51 (s, 1H), 2.33 (s, 6H); 13C NMR (600 MHz, CDC13) δ (ppm): 149.42, 148.66, 144.60, 144.53, 141.58, 139.89, 139.34, 138.27, 137.38, 137.18, 137.15, 136.55, 135.77, 134.95, 134.83, 134.54, 134.13, 133.77, 133.66, 133.59, 133.35, 132.31, 131.53, 130.98, 130.26, 130.21, 129.96, 129.79, 129.03, 128.78, 128.37, 127.66, 125.58, 125.08, 124.44, 123.89, 122.15, 121.42, 121.22, 119.62, 119.54, 42.76, 42.58, 32.04, 29.82, 21.03; HRMS analysis (APCI): calcd for C 41 H 26 Cl6NO2S (M-H) - : 805.9821, found: 805.9815 (error: -0.87 ppm).

[0080]

[0081] In the glove box, compound 4 (25 pmol), potassium tert-butoxide (197 pmol), 18-crown-6 (197 pmol) and anhydrous tetrahydrofuran (10 mL) were added into a 25 mL reaction vial and stirred at room temperature for 5 h. Then, 4,4,5,5-tetramethyl-2-(2-oxopyrrolidin-1-yl)imidazoline-1,3-dione (197 pmol) was added into the reaction vial and stirred at room temperature for another 12 h. The reaction was quenched with saturated brine and the mixture was extracted with dichloromethane for several times. The mixture was dried and purified by column chromatography (petroleum ether: dichloromethane = 1:2 as eluent) to give compound 5 as dark green solid (i.e. product allyl luminous radical ARS-TPA (j)) (11 mg, 57 %). HRMS analysis (APCI): calcd for C 41 H 26 Cl6NO2S (M-H): 805.9821, found: 805.9819 (error: -0.25 ppm). The fluorescence quantum yield was 11.7 % and the half-life under natural light irradiation was 27.5 days.

[0082] Example 2

[0083] Synthesis of allyl luminous radical ARS-Ph (a):

[0084]

[0085] In a 250 mL reaction flask, compound 1 (10.02 mmol), aluminium trichloride (10.22 mmol) and anhydrous dichloromethane (120 mL) were added under nitrogen protection, and the mixture was stirred at 0 °C for 20 min. Compound 6 (9.52 mmol) was added into the reaction flask, and the mixture was stirred at room temperature for 2 h. The reaction was quenched with 0.1 M hydrochloric acid (200 mL), and the mixture was extracted with dichloromethane, dried and purified by column chromatography (petroleum ether as eluent), and the crude product was washed with methanol to give compound 7 as a white solid (3.58 g, 60%), 1 H NMR (600 MHz, CDC13) δ (ppm): 7.76 (d, 1H), 7.43 (d, 1H), 7.31-7.33 (t, 2H), 7.30 (s, 4H), 7.14-7.18 (dd, 4H), 6.74 (s, 1H), 2.34 (s, 3H); 13 C NMR (150 MHz, CDC13) δ (ppm): 140.22, 139.43, 137.67, 137.55, 137.20, 136.73, 134.80, 133.68, 131.72, 129.42, 129.39, 128.81, 124.52, 124.34, 123.23, 122.22, 46.14, 21.45; HRMS analysis (APCI): calcd for C 28 H 15 Cl6S (M-H) - : 592.9031, found: 592.9030 (error: -0.17 ppm).

[0086]

[0087] In a 250 mL reaction flask, hydrogen peroxide (41.86 mmol) and anhydrous dichloromethane (100 mL) were added under nitrogen protection, and trifluoroacetic anhydride (62.79 mmol) was added dropwise at 0 °C, and the mixture was stirred at this temperature for 10 min. Compound 7 (4.19 mmol) was added, and the mixture was stirred at room temperature for 12 h. The reaction was quenched with saturated Na2C03solution, and the mixture was extracted with dichloromethane, dried and purified by column chromatography (petroleum ether: dichloromethane = 1:2 as eluent) to give compound 8 as a white solid (2.13 g, 81%). 1H NMR (600 MHz, CDC13) δ (ppm): 7.80 (d, 1H), 7.46-7.51 (m, 3H), 7.46 (s, 2H), 7.10 (s, 2H), 6.88 (d, 2H), 6.67 (d, 2H), 6.52 (s, 1H), 2.32 (s, 3H); 13 CNMR (600 MHz, CDC13) δ (ppm): 139.75, 139.48, 135.90, 135.65, 133.74, 130.02, 129.87, 128.80, 128.55, 128.33, 127.07, 126.71, 124.34, 123.94, 121.47, 42.40, 21.50, 21.35. HRMS analysis (APCI): calcd for C 28 H 15 Cl6O2S (M-H) - : 624.8929, found: 624.8926 (error: -0.48 ppm). Half-life under natural light irradiation was 5.2 days.

[0088]

[0089] In a glove box under light-free reaction, compound 8 (0.16 mmol), potassium tert-butoxide (1.27 mmol), 18-crown-6 (1.27 mmol) and anhydrous tetrahydrofuran (40 mL) were added into a 100 mL reaction flask, respectively, and reacted at room temperature for 5 h, then added with tetrachlorobenzoquinone (1.27 mmol) and continued to react at room temperature for 12 h. The reaction was quenched with saturated brine, and the mixture was extracted with dichloromethane, then dried and purified by column chromatography (petroleum ether: dichloromethane = 1:2 as eluent) to obtain compound 9 as a brownish yellow solid (i.e. product allyl luminous radical ARS-Ph(a)) (31 mg, 31%). HRMS analysis (APCI): calcd for C 28 H 15 Cl6O2S (M) - : 624.8929, found: 624.8926 (error: -0.48 ppm). Half-life under natural light irradiation was 5.2 days.

[0090] Example 3

[0091] Synthesis of allyl luminous radical ARC-Ph(l):

[0092]

[0093] In a 25 mL reaction vial, compound 1 (0.94 mmol), aluminium trichloride (0.102 mmol) and anhydrous dichloromethane (2 mL) were added under nitrogen protection, and the mixture was stirred at 0 °C for 20 min. Then compound 10 (0.085 mmol) was added into the reaction vial, and the mixture was stirred at room temperature for 2 h. The reaction was quenched with 0.1 M hydrochloric acid (10 mL), and the mixture was extracted with dichloromethane, dried and purified by column chromatography (petroleum ether as eluent), and the crude product was washed with methanol to give compound 11 as a white solid (39 mg, 75%), 1 HNMR (600 MHz, CDC13) δ (ppm): 7.41 (d, 1H), 7.34 (d, 1H), 7.32 (d, 1H), 7.24 (d, 1H), 7.21 (t, 1H), 7.15 (d, 1H), 7.13 (d, 1H), 7.04 (d, 1H), 6.76 (d, 1H), 6.71 (d, 1H), 6.58 (d, 1H), 6.45 (d, 1H), 6.15 (s, 1H), 2.30 (s, 3H), 1.56 (s, 3H), 1.28 (s, 3H); 13 CNMR (150 MHz, CDC13) δ (ppm): 150.42, 141.90, 139.05, 137.63, 136.38, 134.61, 134.52, 132.77, 129.45, 129.09, 129.01, 128.92, 128.56, 127.38, 121.29, 104.16, 47.13, 31.78, 21.36, 17.15; HRMS analysis (APCI): calcd for C 31 H 23 Cl6 (M+H) + : 604.9925, found: 604.9929 (error: 0.66 ppm).

[0094]

[0095] In a 100 mL reaction vial, compound 11 (9.9 μmol), potassium tert-butoxide (99 μmol), 18-crown-6 (99 μmol) and anhydrous tetrahydrofuran (5 mL) were added under nitrogen protection and the mixture was stirred at room temperature for 5 h. Then tetrachloroquinone (99 μmol) was added into the reaction vial, and the mixture was stirred at room temperature for 12 h. The reaction was quenched with saturated brine, and the mixture was extracted with dichloromethane, dried and purified by column chromatography (petroleum ether as eluent) to give compound 12 as a green solid (3 mg, 50%). HRMS analysis (APCI): calcd for C31 H 22 Cl6(M) + :603.9847, found:603.9849 (error:0.33 ppm).

[0096] From Figure 1 (Wherein, ARS-TPA(j), ARS-Ph(a), ARC-Ph(l) respectively represent ARS-TPA(j) in Example 1, ARS-Ph(a) in Example 2, ARS-Ph(l) in Example 3) can be known, the allyl light-emitting free radical material presents two obvious absorption peaks at 350 nm and 410 nm, and shows a long absorption band characteristic of free radicals near 620 nm, after introducing the donor group, ARS-TPA shows significantly enhanced absorption, and the maximum absorption wavelength is 770 nm; its emission spectrum is in the near infrared region, the maximum emission wavelength of ARS-TPA is 843 nm, and the half-peak width is only 50 nm, which is the narrowest among the carbon free radicals in the near infrared region found at present.

[0097] From Figure 2 It can be known that the g value of ARS-Ph(a) is 2.0036.

[0098] From Figure 3 It can be known that the g value of ARS-TPA(j) is 2.0037.

[0099] From Figure 4 It can be known that the half-life of ARS-Ph(a) under natural light irradiation is 5.2 days.

[0100] From Figure 5 It can be known that the half-life of ARS-TPA(j) under natural light irradiation is 27.5 days.

[0101] The above only describes the preferred embodiments of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can also be made, which should be considered as the protection scope of the present application.

Claims

1. An allyl luminescent free radical material, characterized in that, It has the structure shown in Equation I: Where · represents a single electron of a free radical; R can be any of the following structures: X is 2. The allyl luminescent free radical material according to claim 1, characterized in that, The allyl luminescent radical material has the structures shown in formulas a to p:

3. A method for preparing the allyl luminescent free radical material according to claim 1 or 2, characterized in that, When X is The preparation method of an allyl luminescent free radical material having the structure shown in Formula I includes the following steps: Step 1. Compound 1 and compound 2 are subjected to Friedel-Crafts alkylation reaction 1 to obtain Friedel-Crafts alkylated product 1; Step 2. The Friedel-Crafts alkylation product 1 is subjected to an oxidation reaction to obtain an oxidation product; Step 3. The oxidation product is subjected to dehydrogenation reaction 1 to obtain the allyl luminescent free radical material; When X is The preparation method of an allyl luminescent free radical material having the structure shown in Formula I includes the following steps: Step S1. Compound 1 and compound 3 are subjected to Friedel-Crafts alkylation reaction 2 to obtain Friedel-Crafts alkylated product 2; Step S2. The Friedel-Crafts alkylation product 2 is subjected to a dehydrogenation reaction 2 to obtain the allyl luminescent radical material; The structural formula of compound 1 is as follows: The structural formula of compound 2 is as follows: The structural formula of compound 3 is as follows: In compounds 2 and 3, R is the same as R in formula I of claim 1.

4. The preparation method according to claim 3, characterized in that, In step 1, the catalyst used in Friedel-Crafts alkylation reaction 1 is aluminum trichloride, and the solvent is anhydrous dichloromethane; the molar ratio of compound 1 to compound 2 is 1:(0.9-2); the molar ratio of compound 1 to aluminum trichloride is 1:1; the reaction temperature of Friedel-Crafts alkylation reaction 1 is room temperature, and the reaction time is 1-3 h.

5. The preparation method according to claim 3, characterized in that, In step 2, the oxidant used in the oxidation reaction is peroxytrifluoroacetic acid or m-chloroperoxybenzoic acid, and the solvent is anhydrous dichloromethane; the molar ratio of Friedel-Crafts alkylation product 1 to the oxidant peroxytrifluoroacetic acid is 1:(10-15); the molar ratio of Friedel-Crafts alkylation product 1 to the oxidant m-chloroperoxybenzoic acid is 1:(4-5); the oxidation reaction is carried out at room temperature for 12-14 hours.

6. The preparation method according to claim 3, characterized in that, In step 3, the base used in dehydrogenation reaction 1 is potassium tert-butoxide, the catalyst is 18-crown-6, the solvent is tetrahydrofuran, and the oxidant is tetrachlorobenzoquinone; the molar ratio of the oxidation product, potassium tert-butoxide, 18-crown-6, and tetrachlorobenzoquinone is 1:8:8:8; the temperature of dehydrogenation reaction 1 is room temperature, the time is 12 hours, and the reaction is carried out in the dark.

7. The preparation method according to claim 3, characterized in that, In step S1, the catalyst used in the Friedel-Crafts alkylation reaction 2 is aluminum trichloride, and the solvent is anhydrous dichloromethane; the molar ratio of compound 1 to compound 3 is 1:(0.09-0.12); the molar ratio of compound 1 to aluminum trichloride is 1:(0.1-0.2); the reaction temperature of the Friedel-Crafts alkylation reaction 2 is room temperature, and the reaction time is 1-3 h.

8. The preparation method according to claim 3, characterized in that, In step S2, the base in dehydrogenation reaction 2 is potassium tert-butoxide, the catalyst is 18-crown-6, the solvent is tetrahydrofuran, and the oxidant is tetrachlorobenzoquinone; the molar ratio of Friedel-Crafts alkylation product 2 to potassium tert-butoxide, 18-crown-6, and tetrachlorobenzoquinone is 1:10:10:10; the temperature of dehydrogenation reaction 2 is room temperature, and the time is 12 hours.

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