Preparation Method and Application of Boron Cluster Naphthopyran Photochromic Compound

Abstract

The present invention relates to a preparation method and application of a boron cluster naphthopyran photochromic compound, and its molecular structure is shown in Formula I, where Ar represents different aromatic groups; the compound prepared by the present invention has a fast fading rate, shows photochromic and fluorescence properties when irradiated with a low-power ultraviolet lamp at room temperature, has a rapid light response and good fatigue resistance; for this type of compound, as the irradiation time increases, the absorbance value increases, while the fluorescence intensity decreases instead. After the absorbance value reaches saturation, during the fading process, the fluorescence intensity gradually increases, and after fading to colorless, the fluorescence intensity returns to the initial value; this process realizes the regulation of the fluorescence intensity of the boron cluster by light-induced color change, which greatly expands the application fields of naphthopyran and has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of organic optofunctional materials, and particularly relates to a preparation method and application of a boron cluster naphthopyran photochromic compound. Background Art

[0002] With the development of sunlight conversion technology, the combination of organic optofunctional materials and photovoltaic devices improves the utilization rate of light, which greatly accelerates the development of optofunctional materials. As an optofunctional material, under light irradiation, the molecules of naphthopyran transition from the ground state to the excited state, the C-O bond in the pyran ring breaks, the carbon-carbon double bond twists, and the benzene rings orthogonally repelled on both sides of the naphthalene ring rotate approximately 90° within the molecule. The conjugation degree of the whole molecule changes, resulting in the redshift of its absorption spectrum from the ultraviolet region to the visible light region, so it shows color externally. Under darkness or thermal action, the open-ring form closes back to the original structure again, and the absorption correspondingly shifts to the ultraviolet region, thus restoring the colorless state. Under the action of light, naphthopyran can switch between two states.

[0003] However, naphthopyran has problems such as slow fading rate and residual color in the solid state environment, which affect the rapid conversion between the two stable states. In order to improve the fading rate of naphthopyran, some scientific researchers modified the molecular structure and used the intramolecular force to sterically prevent the double bond isomerization of the TC structure in space, thereby reducing the content of TT and increasing the fading rate. The members of the Paulo J. Coelho research group constructed a bridged ring between the naphthalene ring and the double bond, so that only one isomer of TC is formed after ring opening, increasing the fading rate (J. Org. Chem. 2015, 80, 12177 - 12181). The Jiro research group used hydrogen bond induction to reduce the structure of TT, and the fading rate was accelerated (Adv. Mater. 2019, 31: 1805661). Although the above methods have solved the problem of slow fading rate to a certain extent, the synthesis steps are complex and the cost is high, reducing their practical application value.

[0004] A boron cluster is a twelve-vertex icosahedral closed cage structure composed of two carbon atoms, ten boron atoms and twelve hydrogen atoms, with three-dimensional large steric hindrance. According to the positions of the two carbon atoms, boron clusters are divided into ortho, meta and para types. In terms of photoelectric properties and energy, the structures of boron cluster derivatives are vertically distributed. Using the structural characteristics of boron clusters, two planar groups can be twisted into a face-to-face conjugated structure through intramolecular torsion, which has great advantages in the field of optoelectronic materials.

[0005] The present invention aims to provide a naphthopyran photochromic compound that uses the characteristics of boron clusters to improve the color change rate of naphthopyran and reduce the residual color, further broadening the use of naphthopyran as an optofunctional material. Summary of the Invention

[0006] The object of the present invention is to provide a boron cluster naphthopyran photochromic compound,

[0007] Another object of the present invention is to provide a preparation method and application of the boron cluster naphthopyran photochromic compound.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A boron cluster naphthopyran photochromic compound, and this kind of compound has the structure shown in Formula I:

[0010]

[0011] In the formula, Ar is any one of, where * represents the connection site.

[0012] The o-carborane is an icosahedral three-dimensional structure, has three-dimensional aromaticity, and has strong electron-withdrawing ability. The aromatic groups connected on both sides of the two carbon atoms become face-to-face conjugation. This kind of compound has excellent optical properties and a unique three-dimensional structure.

[0013] This technical solution utilizes the three-dimensional structural characteristics of o-carborane, connects the naphthalene ring and aromatic groups with different substituents to two carbons respectively, and the naphthalene ring plane and the two planes of the aromatic groups in the direction form a "V" structure. After the pyran ring is opened, it is orthogonal to the naphthalene ring plane, and the aromatic group on the other side exerts resistance to the torsion of the carbon-carbon double bond of the TC structure, thereby reducing the generation of TT.

[0014] The preparation method of the compound of the present invention includes the following steps:

[0015] Step 1: 1-Bromo-4-methoxynaphthol reacts with in a basic solvent under the catalysis of a palladium catalyst to generate Compound 1, and the reaction formula is as follows:

[0016]

[0017] Step 2: Compound 1 reacts with decaborane dodecaethyl sulfide to generate Compound 2, and the reaction formula is as follows:

[0018]

[0019] Step 3: Compound 2 reacts under the catalysis of boron tribromide to generate Compound 3

[0020]

[0021] Step 4: Compound 3 reacts with 1,1-(diaryl)-2-propyn-1-ol under the catalysis of an organic acid to generate the photochromic compound I, and the reaction formula is as follows:

[0022]

[0023] In the above preparation method, in the first-step reaction, the catalyst used is tetrakis(triphenylphosphine)palladium, the cocatalyst is cuprous iodide, the basic solvent is triethylamine, the reaction temperature is 80 - 90 °C, the reaction time is 18 - 24 h, and the reaction is carried out under the protection of an inert gas. Among them, the molar ratio of 1-bromo-4-methoxynaphthol to tetrakis(triphenylphosphine)palladium is 1:0.05, the molar ratio of 1-bromo-4-methoxynaphthol to phenylacetylene is 1:(2.2 - 2.5), and the molar ratio of 1-bromo-4-methoxynaphthol to cuprous iodide is 1:0.05.

[0024] In the second-step reaction, an aromatic solvent is used, preferably toluene, the reaction temperature is 100 - 120 °C, and the reaction time is 20 - 24 h. Among them, the molar ratio of compound 1 to bis(ethylcyclopentadienyl)decaborane is 1:1.2.

[0025] In the third-step reaction, boron tribromide is used as the catalyst, the reaction solvent is dichloromethane or chloroform, the reaction temperature is 0 °C, and the reaction time is 16 - 20 h. Among them, the molar ratio of compound 2 to boron tribromide is 1:(2.5 - 3).

[0026] Preferably, in the fourth-step reaction, the organic acid used is dodecylbenzenesulfonic acid, the reaction solvent is at least one of toluene or xylene, the reaction temperature is 40 - 50 °C, and the reaction time is 3 - 6 h. Among them, the molar ratio of compound 3 to 1,1-(diaryl)-2-propyn-1-ol is 1:(1 - 1.3).

[0027] The biggest feature of the photochromic compound prepared by this technical solution is that the molecular structure contains a boron cluster icosahedron three-dimensional structure. In order to obtain this structure, the intermediate compounds 1 - 3 and their preparation processes are also particularly important. Specifically, the intermediates include compounds 1 - 3, which have the following structures respectively:

[0028]

[0029] Through intermediate compound 3, other photochromic compounds not limited to those described in the present invention can be prepared.

[0030] In the above reaction formula, Ar is any one of, where * represents the connection site.

[0031] The drugs and reagents used in the above reactions are all well-known materials in the art and can be obtained through commercial purchase.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] The photochromic compound prepared by the present invention can effectively control the content of TT according to the length and rigidity of the aromatic group, thereby controlling the fading rate of the naphthopyran photochromic compound. The naphthopyran compound turns purple-red after being irradiated with ultraviolet light in the solution state and fades rapidly after being irradiated with sunlight, t 1 / 2 The fastest is less than 3 seconds. Such compounds change color and fade rapidly, have basically no residual color, high chroma, and excellent fatigue resistance, and have broad application prospects. Description of the Drawings

[0034] Figure 1 Is the ultraviolet absorption spectrum of the fading of Compound Ia in solution;

[0035] Figure 2 Is the fatigue resistance cycle test chart of Compound Ia in solution;

[0036] Figure 3 Is the fluorescence intensity change chart of Compound Ia in solution with the irradiation time;

[0037] Figure 4 Is the fluorescence emission spectrum of Compound Ia in the PMMA film. Detailed Embodiments

[0038] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the embodiments of the present invention in detail. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Example 1: Preparation of the photochromic compound Ia

[0040] Step 1: Preparation of Compound I-1, the reaction formula is as follows:

[0041]

[0042] Add 1-bromo-4-methoxynaphthol (1.2 g, 5 mmol), phenylacetylene (1.12 g, 11 mmol), tetrakis(triphenylphosphine)palladium (578 mg, 0.5 mmol), copper iodide (48 mg, 0.25 mmol), and triethylamine (30 mL) to a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry with anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is petroleum ether (60-90 °C) to obtain a white solid product I-1 with a yield of 69%. Mp: 89.6-90.3 °C.

[0043] The obtained white solid product was used as a solvent with CDCl3 for 1 1H NMR test and 13 13C NMR test, and the obtained NMR data are characterized as follows:

[0044] The characterization data of the 1H nuclear magnetic resonance spectrum of compound I-1 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.41 (d, J = 8.3 Hz, 1H), 8.30 (d, J = 8.3 Hz, 1H), 7.71 (d, J = 8.0 Hz, 1H), 7.66 - 7.61 (m, 3H), 7.54 (t, J = 8.0 Hz, 1H), 7.38 (m, 3H), 6.82 (d, J = 8.0 Hz, 1H), 4.04 (s, 3H).

[0045] The characterization data of the 13C nuclear magnetic resonance spectrum of compound I-1 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 156.08, 134.26, 131.57, 131.11, 128.47, 128.07, 127.38, 126.09, 125.81, 125.47, 123.90, 122.37, 113.06, 103.70, 92.80, 87.96, 55.65.

[0046] Step 2: Preparation of compound I-2. The reaction formula is as follows:

[0047]

[0048] Compound I-1 (774 mg, 3 mmol), boron dodecahydride bis(ethyl sulfide) complex (1.0 g, 3.6 mmol), and toluene (5 mL) were added to a 100 mL Schlenk tube. Under nitrogen protection, the oil bath was heated to 100 °C and the reaction was carried out for 24 h. After the reaction was completed, the reaction solution was concentrated under reduced pressure to remove the solvent. The residue was passed through a basic alumina column to remove sulfur-containing impurities, and then separated by silica gel column chromatography. The eluent was a mixed solvent of petroleum ether / ethyl acetate (volume ratio of petroleum ether / ethyl acetate was 10:1), and a yellow solid product I-2 was obtained with a yield of 11%. Mp: 188.6 - 190.2 °C.

[0049] The obtained yellow solid product was used as a solvent with CDCl3 for 1 1H NMR test and 13 13C NMR test, and the obtained NMR data are characterized as follows:

[0050] The characterization data of the 1H nuclear magnetic resonance spectrum of compound I-2 are as follows: 1HNMR(400MHz,Chloroform-d)δ9.00(d,J=8.0Hz,1H),8.28(d,J=8.4Hz 1H),7.85(d,J=8.0Hz,1H),7.64(t,J=7.6Hz 1H),7.48(t,J=7.6Hz,1H),7.31(d,J=7.6Hz,2H),7.13(t,J=8.0Hz,1H),7.00(t,J=8.0Hz,2H),6.49(d,J=8.0Hz,1H),3.89(s,3H),3.69-1.99(m,10H).

[0051] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound I-2 are as follows: 13 C NMR(101MHz,CDCl3)δ157.59,134.84,132.78,131.13,130.35,129.92,128.13,127.32,125.96,125.15,124.68,122.90,117.68,102.31,89.45,89.01,55.59.

[0052] Step 3: Preparation of Compound I-3, and the reaction formula is as follows:

[0053]

[0054] Add Compound I-2 (120 mg, 0.32 mmol) and dichloromethane (15 mL) to a 100 mL Schlenk tube. Under nitrogen protection, slowly add boron tribromide (0.5 mL) in an ice bath. After one hour, bring the reaction to room temperature and react for 12 h. After the reaction is completed, add dichloromethane (20 mL) with a syringe, then slowly add water (20 mL) with a syringe. After the reaction no longer reacts violently, add water (40 mL) again. Extract with dichloromethane (20 mL × 2), combine the organic phases and dry over anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography (petroleum ether / ethyl acetate = 4:1) to obtain the yellow liquid product I-3 with a yield of 76%.

[0055] Use the obtained yellow liquid product as the solvent with CDCl3 to conduct 1 HNMR test and 13 C NMR test, and the nuclear magnetic data obtained are characterized as follows:

[0056] The characterization data of the nuclear magnetic resonance hydrogen spectrum of Compound 3 are as follows: 11H NMR (400 MHz, Chloroform-d) δ 9.02 (d, J = 12.0 Hz, 1H), 8.22 (d, J = 8.0 Hz, 1H), 7.76 (d, J = 12.0 Hz, 1H), 7.65 (t, J = 8.0 Hz, 1H), 7.50 (t, J = 8.0 Hz, 1H), 7.30 (d, J = 8.0 Hz, 2H), 7.12 (dd, J = 12.0 Hz, J = 8.0 Hz, 1H), 7.02 (t, J = 8.0 Hz, 2H), 6.47 (d, J = 8.0 Hz, 1H), 5.98 (s, 1H), 3.42 - 1.77 (m, 10H).

[0057] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound 3 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 154.18, 134.57, 133.23, 131.08, 130.37, 129.98, 128.14, 127.53, 125.17, 124.83, 122.86, 118.07, 107.05, 89.46, 88.89.

[0058] Step 4: Preparation of the photochromic compound Ia, and the reaction formula is as follows:

[0059]

[0060] Add 3 (77 mg, 0.21 mmol), (57 mg, 0.21 mmol), toluene (5 mL) and 1 drop of dodecylbenzenesulfonic acid into a 50 mL round-bottom flask. Heat in an oil bath to 40 °C and react for 3 h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 4:1) to obtain the yellow solid product Ia with a yield of 83%. Mp: 195.7 - 196.4 °C.

[0061] Take the obtained yellow solid product as the solvent with CDCl3 and perform 1 1H NMR test and 13 13C NMR test respectively, and the nuclear magnetic data obtained are characterized as follows:

[0062] The characterization data of the nuclear magnetic resonance hydrogen spectrum of Compound Ia are as follows: 11H NMR (400 MHz, Chloroform-d) δ 8.92 (d, J = 8.0 Hz, 1H), 8.33 (d, J = 8.4 Hz, 1H), 7.59 (s, 1H), 7.56 (d, J = 8.0 Hz, 1H), 7.46 (t, J = 8.0 Hz, 1H), 7.28 (m, 4H), 7.22 (d, J = 8.0 Hz, 2H), 7.03 (t, J = 7.2 Hz, 1H), 6.89 (t, J = 8.0 Hz, 2H), 6.82 (m, 4H), 6.48 (d, J = 8.0 Hz, 1H), 6.08 (d, J = 8.0 Hz, 1H), 3.78 (s, 6H), 3.69 - 1.92 (m, 10H).

[0063] The characterization data of the carbon nuclear magnetic resonance spectrum of compound Ia are as follows: 13 13C NMR (101 MHz, CDCl3) δ 159.01, 150.35, 136.71, 133.04, 132.86, 130.86, 130.21, 129.89, 128.42, 128.11, 127.99, 127.27, 125.43, 125.17, 124.96, 122.87, 122.35, 117.69, 113.84, 113.50, 89.48, 88.69, 83.82, 55.27.

[0064] Example 2: Preparation of the photochromic compound IIa

[0065] Step 1: Preparation of compound II-1, and the reaction formula is as follows:

[0066]

[0067] Add 1-bromo-4-methoxynaphthol (1.2 g, 5 mmol), 2-naphthylacetylene (1.12 g, 11 mmol), tetrakis(triphenylphosphine)palladium (578 mg, 0.5 mmol), copper(I) iodide (48 mg, 0.25 mmol) and triethylamine (30 mL) into a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry with anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is petroleum ether (60 °C - 90 °C) to obtain the white solid product II-1 with a yield of 67%. Mp: 145.4 - 146.1 °C.

[0068] Using the obtained white solid product as the solvent with CDCl3, perform 1 1H NMR test and 1313C NMR test, and the nuclear magnetic data obtained are characterized as follows:

[0069] The characterization data of the 1H NMR spectrum of compound II-1 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.47 (d, J = 8.0 Hz, 1H), 8.32 (d, J = 8.0 Hz, 1H), 8.16 (s, 1H), 7.86 (m, 3H), 7.76 (d, J = 8.0 Hz, 1H), 7.72 - 7.68 (m, 1H), 7.68 - 7.63 (m, 1H), 7.56 (t, J = 8.0 Hz, 1H), 7.52 (t, J = 4.0 Hz, 2H), 6.83 (d, J = 8.0 Hz, 1H), 4.05 (s, 3H).

[0070] The characterization data of the 13C NMR spectrum of compound II-1 are as follows: 13 13C NMR (101 MHz, Chloroform-d) δ 156.13, 134.29, 133.21, 132.77, 131.22, 131.15, 128.57, 128.10, 127.86, 127.82, 127.43, 126.61, 126.58, 126.13, 125.85, 125.49, 122.40, 121.21, 113.08, 103.74, 93.25, 88.38, 56.28.

[0071] Step 2: Preparation of compound II-2, and the reaction formula is as follows:

[0072]

[0073] Add compound II-1 (308 mg, 1 mmol), boron dodecahydride bis(ethyl sulfide) complex (360 mg, 1.2 mmol), and toluene (5 mL) to a 100 mL Schlenk tube. Under nitrogen protection, heat in an oil bath to 100 °C and react for 24 h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is passed through a basic alumina column to remove sulfur-containing impurities, and then separated by silica gel column chromatography. The eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 40:1) to obtain a yellow solid product II-2 with a yield of 17%. Mp: 165.8 - 166.5 °C.

[0074] Use the obtained yellow solid product as the solvent with CDCl3 to conduct 1 1H NMR test and 13 13C NMR test, and the nuclear magnetic data obtained are characterized as follows:

[0075] The characterization data of the 1H NMR spectrum of compound II-2 are as follows:1 HNMR (400 MHz, Chloroform-d) δ 9.06 (d, J = 8.0 Hz, 1H), 8.24 (d, J = 8.0 Hz, 1H), 7.91 (d, J = 8.0 Hz, 1H), 7.84 (s, 1H), 7.68 (d, J = 8.0 Hz, 1H), 7.63 (d, J = 8.0 Hz, 1H), 7.56 (d, J = 8.0 Hz, 1H), 7.49 (d, J = 8.0 Hz, 1H), 7.45 (d, J = 8.0 Hz, 1H), 7.41 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 8.0 Hz, 2H), 6.41 (d, J = 8.0 Hz, 1H), 3.79 (s, 3H), 3.26 - 2.09 (m, 10H).

[0076] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound II-2 are as follows: 13 C NMR (101 MHz, Chloroform-d) δ 157.59, 134.95, 133.28, 132.80, 132.18, 131.12, 128.61, 127.83, 127.52, 127.37, 127.22, 126.63 (d, J = 2.1 Hz), 125.96, 125.14, 124.63, 122.93, 117.77, 102.37, 89.77, 89.59, 55.49.

[0077] Step 3: Preparation of Compound II-3, the reaction formula is as follows:

[0078]

[0079] Add Compound II-2 (120 mg, 0.32 mmol) and dichloromethane (15 mL) to a 100 mL Schlenk tube, evacuate and replace with nitrogen for protection. Add boron tribromide (0.5 mL) in an ice bath. After one hour, bring the reaction to room temperature and react for 12 h. After the reaction is completed, add dichloromethane (20 mL) with a syringe, then slowly add water (20 mL) with a syringe. After the violent reaction stops, add water (40 mL). Extract with dichloromethane (20 mL × 2). Combine the organic phases and dry over anhydrous magnesium sulfate. Concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography (petroleum ether / ethyl acetate = 4:1) to obtain the yellow solid product II-3 with a yield of 68%. Mp: 81.6 - 82.4 °C.

[0080] Using the obtained yellow solid product as the solvent with CDCl3, conduct 1 HNMR tests and 13 C NMR tests, and the nuclear magnetic data obtained are characterized as follows:

[0081] The characterization data of the 1H NMR spectrum of Compound II-3 are as follows: 1 HNMR(400MHz,Chloroform-d)δ9.10(d,J=8.0Hz,1H),8.21(d,J=8.0Hz,1H),7.84(d,J=8.0Hz,2H),7.70(t,J=8.0Hz,1H),7.64(d,J=8.0Hz,1H),7.57(d,J=8.0Hz,1H),7.51(t,J=8.0Hz,1H),7.46(d,J=12.0Hz,1H),7.42(d,J=8.0Hz,1H),7.38(d,J=8.0Hz,2H),6.42(d,J=8.0Hz,1H),3.86-1.84(m,10H).

[0082] The characterization data of the 13C NMR spectrum of Compound II-3 are as follows: 13 C NMR(101MHz,CDCl3)δ154.37,134.73,133.28,133.26,132.15,131.12,129.09,128.56,128.28,127.86,127.57,127.24,126.70,126.62,125.12,124.87,124.77,122.93,118.01,107.08,89.82,89.56.

[0083] The preparation of the photochromic compound IIa is shown by the following reaction formula:

[0084]

[0085] Add II-3(70mg,0.17mmol),1,1-(dimethoxyphenyl)-2-propyn-1-ol(46mg,0.17mmol),toluene(5mL) and 1 drop of dodecylbenzenesulfonic acid into a 50 mL round-bottom flask. Heat the mixture in an oil bath to 40 °C and react for 3 h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 4:1), obtaining a yellow solid product IIa with a yield of 75%. Mp: 166.5-167.1 °C.

[0086] Using the obtained yellow solid product as the solvent with CDCl3, conduct 1 1H NMR tests and 13 13C NMR tests respectively, and the obtained NMR data are characterized as follows:

[0087] The characterization data of the 1H NMR spectrum of Compound IIa are as follows: 1 HNMR(400MHz,Chloroform-d)δ8.97(d,J=8.0Hz,1H),8.27(d,J=8.0Hz,1H),7.82(s,1H),7.70(s,1H),7.63(d,J=8.0Hz,1H),7.57(d,J=8.0Hz,1H),7.54(d,J=8.0Hz,1H),7.44(d,J=8.0Hz,2H),7.38(t,J=8.0Hz,2H),7.32(d,J=8.0Hz,1H),7.18(d,J=8.0Hz,4H),6.43(d,J=8.0,1H),5.98(d,J=8.0,1H),3.75(s,6H),3.64-2.01(m,10H).

[0088] The characterization data of the 13C NMR spectrum of Compound IIa are as follows: 13 C NMR(101MHz,CDCl3)δ158.98,150.34,136.72,133.29,133.19,133.07,132.16,131.09,128.53,128.49,128.06,127.88,127.50,127.36,127.27,126.68,126.53,125.45,125.15,124.91,122.99,121.98,117.81,113.54,113.50,89.92,89.48,89.46,83.98,55.23.

[0089] Example 3: Preparation of Photochromic Compound IIIa

[0090] Step 1: Preparation of Compound III-1. The reaction is as follows:

[0091]

[0092] Add 1-bromo-4-methoxynaphthol (1.2 g, 5 mmol), 2-naphthylacetylene (1.12 g, 11 mmol), tetrakis(triphenylphosphine)palladium (578 mg, 0.5 mmol), copper(I) iodide (48 mg, 0.25 mmol) and triethylamine (30 mL) into a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry with anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is petroleum ether (60-90 °C) to obtain the white solid product III-1 with a yield of 62%. Mp: 191.3-191.9 °C.

[0093] The obtained white solid product was used as a solvent with CDCl3 and subjected to 1 1H NMR tests and 13 13C NMR tests, and the obtained NMR data are characterized as follows:

[0094] The characterization data of the 1H nuclear magnetic resonance spectrum of compound III-1 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.33 (d, J = 8.0 Hz, 1H), 8.22 (d, J = 8.0 Hz, 1H), 7.66 - 7.59 (m, 3H), 7.58 - 7.50 (m, 5H), 7.46 (d, J = 8.0 Hz, 1H), 7.38 (t, J = 8.0 Hz, 2H), 7.29 (d, J = 8.0 Hz, 1H), 6.73 (d, J = 8.0 Hz, 1H), 3.95 (s, 3H).

[0095] The characterization data of the 13C nuclear magnetic resonance spectrum of compound III-1 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 156.08, 140.71, 140.47, 134.21, 131.93, 131.07, 128.89, 127.61, 127.36, 127.08, 127.04, 126.96, 126.06, 125.79, 125.44, 122.76, 122.33, 113.07, 103.69, 92.67, 88.60, 55.66, 29.74.

[0096] Step 2: Preparation of compound III-2. The reaction formula is as follows:

[0097]

[0098] Compound III-1 (774 mg, 3 mmol), borodecahydridediethyldisulfide complex (1.0 g, 3.6 mmol), and toluene (5 mL) were added to a 100 mL Schlenk tube. Under nitrogen protection, the mixture was heated to 100 °C in an oil bath and reacted for 24 h. After the reaction was completed, the reaction solution was concentrated under reduced pressure to remove the solvent. The residue was passed through a basic alumina column to remove sulfur-containing impurities, and then separated by silica gel column chromatography. The eluent was a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate was 10:1), and a yellow solid product III-2 was obtained with a yield of 10.6%. Mp: 167.2 - 167.8 °C.

[0099] The obtained yellow solid product was used as a solvent with CDCl3 and subjected to 1 1H NMR tests and 1313C NMR test, and the nuclear magnetic data obtained are characterized as follows:

[0100] The characterization data of the 1H NMR spectrum of Compound III-2 are as follows: 1 1H NMR(400MHz,Chloroform-d)δ8.99(d,J=8.0Hz,1H),8.25(d,J=8.0Hz,1H),7.87(d,J=8.6Hz,1H),7.62(t,J=8.0Hz,1H),7.46(t,J=7.6Hz,1H),7.38(d,J=7.6Hz,2H),7.35-7.33(m,2H),7.32(s,1H),7.29(d,J=4.0Hz,1H),7.21(t,J=8.0Hz,3H),6.48(d,J=8.0Hz,1H),3.85(s,3H),3.74-1.83(m,10H).

[0101] The characterization data of the 13C NMR spectrum of Compound III-2 are as follows: 13 13C NMR(1MHz,CDCl3)δ157.68,142.45,139.21,134.97,132.83,130.81,130.20,128.85,128.01,127.40,126.90,126.63,126.04,125.20,124.70,123.02,117.76,102.43,89.50,89.36,55.59.

[0102] Step 3: Preparation of Compound III-3. The reaction formula is as follows:

[0103]

[0104] Add Compound III-2(120mg,0.32mmol) and dichloromethane(15mL) to a 100mL Schlenk tube. Under nitrogen protection, add boron tribromide(0.5mL) in an ice bath. After one hour, bring the reaction to room temperature and react for 12h. After the reaction is completed, add dichloromethane(20mL) with a syringe, then slowly add water(20mL) with a syringe. After the reaction is no longer violent, add another 40mL of water. Extract with dichloromethane(20mL×2). Combine the organic phases and dry over anhydrous magnesium sulfate. Concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography(petroleum ether / ethyl acetate = 4:1) to obtain the yellow solid product III-3 with a yield of 76%. Mp: 199.7-200.5℃.

[0105] Using the obtained yellow solid product as the solvent with CDCl3, conduct 1 1H NMR test and13 The 13C NMR test was carried out, and the NMR data obtained are characterized as follows:

[0106] The characterization data of the 1H NMR spectrum of compound III-3 are as follows: 1 1H NMR(400MHz,Chloroform-d)δ9.05(d,J=8.0Hz,1H),8.23(d,J=8.0Hz,1H),7.82(d,J=8.4Hz,1H),7.67(t,J=8.0Hz,1H),7.51(t,J=8.0Hz,1H),7.40-7.29(m,7H),7.22(d,J=8.0Hz,2H),6.48(d,J=8.0Hz,1H),6.02(s,1H),4.04-1.54(m,10H).

[0107] The characterization data of the 13C NMR spectrum of compound III-3 are as follows: 13 13C NMR(101MHz,CDCl3)δ154.32,142.48,139.18,134.67,133.26,130.80,130.15,128.83,128.00,127.54,126.91,126.60,125.15,124.89,124.84,122.93,118.10,107.14,89.46,89.21.

[0108] Step 4: Preparation of the photochromic compound IIIa, and the reaction formula is as follows:

[0109]

[0110] III-3(41mg,0.09mmol), 1,1-(dimethoxyphenyl)-2-propyn-1-ol(25mg,0.09mmol), toluene(5mL) and 1 drop of dodecylbenzenesulfonic acid were added to a 50 mL round-bottom flask. The mixture was heated to 40 °C in an oil bath and reacted for 3 h. After the reaction was completed, the reaction solution was concentrated under reduced pressure to remove the solvent. The residue was separated by silica gel column chromatography, and the eluent was a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate was 4:1), and a yellow solid product IIIa was obtained with a yield of 73%.

[0111] The obtained yellow solid product was used as a solvent with CDCl3 for 1 1H NMR test and 13 13C NMR test, and the NMR data obtained are characterized as follows: Mp: 258.3-259.1 °C.

[0112] The characterization data of the 1H NMR spectrum of compound IIIa are as follows: 1HNMR(400MHz,Chloroform-d)δ8.95(d,J=8.0Hz,1H),8.30(d,J=8.0Hz,1H),7.64(t,J=4.0Hz,1H),7.58(t,J=4.0Hz,1H),7.43-7.32(m,7H),7.28-7.18(m,7H),6.74(m,4H),6.46(d,J=8.0Hz,1H),6.02(d,J=8.0Hz,1H),3.69(s,6H),3.47-2.05(m,10H).

[0113] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound IIIa are as follows: 13 C NMR(101MHz,CDCl3)δ159.00,142.66,139.43,136.74,133.02,130.78,130.12,128.85,128.09,127.99,127.92,127.30,127.03,126.70,125.40,124.96,123.04,121.94,117.72,113.50,88.91,84.07,55.19.

[0114] Example 4: Preparation of Photochromic Compound IV

[0115] Step 1: Preparation of Compound IV-1, and the reaction formula is as follows:

[0116]

[0117] Add 1-bromo-4-methoxynaphthol (1.2g, 5mmol), 2-methyl-3-butyn-2-ol (1.12g, 11mmol), tetrakis(triphenylphosphine)palladium (578mg, 0.5mmol), copper(I) iodide (48mg, 0.25mmol) and triethylamine (30mL) into a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry with anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography with petroleum ether (60 - 90 °C) to obtain a white solid product IV-1 with a yield of 75%. Mp: 85.6 - 86.2 °C.

[0118] Using the obtained white solid product as a solvent with CDCl3, perform 1 HNMR test and 13 C NMR test, and the obtained nuclear magnetic data are characterized as follows:

[0119] The characterization data of the nuclear magnetic resonance hydrogen spectrum of Compound IV-1 are as follows:1 1H NMR (400 MHz, Chloroform-d) δ 8.30 - 8.22 (m, 2H), 7.61 - 7.56 (m, 2H), 7.51 (m, 1H), 6.72 (d, J = 8.0 Hz, 1H), 3.98 (s, 3H), 1.74 (s, 6H).

[0120] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound IV-1 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 155.94, 134.20, 131.04, 127.29, 125.82, 125.70, 125.34, 122.27, 112.41, 103.47, 97.19, 80.44, 65.95, 55.60, 31.80.

[0121] Step 2: Preparation of Compound IV-2, the reaction formula is as follows:

[0122]

[0123] Add IV-1 (2.4 g, 10 mmol), potassium hydroxide (1.2 g, 30 mmol) and toluene (30 mL) into a 250 mL single-necked flask, heat with stirring under reflux for 12 h. After the reaction is completed, cool to room temperature, filter potassium hydroxide, remove the solvent under reduced pressure, and separate the residue by silica gel column chromatography. The eluent is petroleum ether (60 - 90 °C) to obtain colorless oily liquid IV-2 with a yield of 54%.

[0124] Use the obtained colorless oily product as the solvent with CDCl3 and conduct 1 1H NMR test and 13 13C NMR test respectively, and the nuclear magnetic data obtained are characterized as follows:

[0125] The characterization data of the proton nuclear magnetic resonance spectrum of Compound IV-2 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.33 (d, J = 8.0 Hz, 1H), 8.30 (d, J = 8.0 Hz, 1H), 7.70 (d, J = 8.0 Hz, 1H), 7.62 (t, J = 8.0 Hz, 1H), 7.54 (t, J = 8.0 Hz, 1H), 6.76 (d, J = 8.0 Hz, 1H), 4.01 (s, 3H), 3.43 (s, 1H).

[0126] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound IV-2 are as follows: 1313C NMR (101 MHz, CDCl3) δ 156.35, 134.48, 131.98, 127.49, 125.88, 125.83, 125.33, 122.34, 111.86, 103.42, 82.16, 80.37, 55.63.

[0127] Step 3: Preparation of Compound IV-3, the reaction formula is as follows:

[0128]

[0129] Add IV-5 (488 mg, 2 mmol), 2-bromofluorene (437 mg, 2.4 mmol), bis(triphenylphosphine)palladium(II) chloride (71 mg, 0.1 mmol), copper(I) iodide (20 mg, 0.1 mmol), triphenylphosphine (20 mg, 0.1 mmol) and triethylamine (30 mL) into a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry with anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is petroleum ether (60 - 90 °C) to obtain the white solid product IV-3 with a yield of 72%. Mp: 204.3 - 204.9 °C.

[0130] Take the obtained white solid product as the solvent with CDCl3 and conduct 1 1H NMR test and 13 13C NMR test respectively, and the obtained NMR data are characterized as follows:

[0131] The nuclear magnetic resonance hydrogen spectrum characterization data of Compound IV-3 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.45 (d, J = 8.3 Hz, 1H), 8.31 (d, J = 8.3 Hz, 1H), 7.82 (s, 1H), 7.80 (d, J = 4.0 Hz, 1H), 7.79 (s, 1H), 7.73 (d, J = 8.0 Hz, 1H), 7.67 (d, J = 4.0 Hz, 1H), 7.65 (d, J = 4.0 Hz, 1H), 7.57 (d, J = 4.0 Hz, 1H), 7.54 (d, J = 8.0 Hz, 1H), 7.41 (t, J = 7.4 Hz, 1H), 7.34 (t, J = 7.4 Hz, 1H), 6.82 (d, J = 8.0 Hz, 1H), 4.04 (s, 3H), 3.95 (s, 2H).

[0132] The nuclear magnetic resonance carbon spectrum characterization data of Compound IV-3 are as follows: 1313C NMR (101 MHz, CDCl3) δ 155.97, 143.59, 143.29, 141.65, 141.21, 134.21, 130.96, 130.40, 128.06, 127.31, 127.11, 126.94, 126.11, 125.78, 125.43, 125.13, 122.31, 121.87, 120.18, 119.86, 113.23, 103.70, 93.54, 87.89, 55.66, 36.80.

[0133] Step 4: Preparation of Compound IV-4, the reaction formula is as follows:

[0134]

[0135] Add Compound IV-3 (346 mg, 1 mmol), boron dodecahydride diethyl sulfide complex (360 mg, 1.2 mmol) and toluene (5 mL) into a 100 mL Schlenk tube. Under nitrogen protection, heat the mixture in an oil bath to 100 °C and react for 24 h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is passed through a basic alumina column to remove sulfur-containing impurities, and then separated by silica gel column chromatography. The eluent is a mixed solvent of petroleum ether / ethyl acetate (volume ratio of petroleum ether / ethyl acetate is 100:1) to obtain a yellow solid product IV-4 with a yield of 14%. Mp: 205.3 - 206.2 °C.

[0136] The obtained yellow solid product was used as a solvent with CDCl3 for 1 1H NMR test and 13 13C NMR test, and the obtained NMR data are characterized as follows:

[0137] The characterization data of the nuclear magnetic resonance hydrogen spectrum of Compound IV-4 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 9.09 (d, J = 9.0 Hz, 1H), 8.29 (d, J = 8.4 Hz, 1H), 7.96 (d, J = 8.6 Hz, 1H), 7.71 (t, J = 7.9 Hz, 1H), 7.57 (d, (d, J = 4.0 Hz, 1H), 7.53 (d, J = 8.0 Hz, 2H), 7.44 (d, J = 4.0 Hz, 1H), 7.34 (t, J = 8.0 Hz, 2H), 7.32 - 7.28 (m, 2H), 6.50 (d, J = 8.0 Hz, 1H), 3.85 (s, 3H), 3.59 (s, 2H), 3.14 - 1.83 (m, 10H).

[0138] The characterization data of the nuclear magnetic resonance carbon spectrum of Compound IV-4 are as follows: 1313C NMR (101 MHz, CDCl3) δ 157.61, 143.77, 143.36, 142.96, 140.13, 135.01, 132.87, 129.52, 129.36, 127.59, 127.36, 127.10, 126.90, 125.96, 125.16, 125.05, 124.70, 122.98, 120.39, 119.25, 117.85, 102.37, 90.66, 89.74, 55.52, 36.61.

[0139] Step 5: Preparation of Compound IV-5, the reaction formula is as follows:

[0140]

[0141] Add Compound IV-4 (63 mg, 0.13 mmol) and dichloromethane (15 mL) to a 100 mL Schlenk tube, evacuate and replace with nitrogen for protection. Add boron tribromide (0.5 mL) in an ice bath. After one hour, bring the reaction to room temperature and react for 12 h. After the reaction is completed, add dichloromethane (20 mL) with a syringe, then slowly add water (20 mL) with a syringe. After the reaction is no longer violent, add another portion of water (40 mL). Extract with dichloromethane (20 mL × 2), combine the organic phases and dry over anhydrous magnesium sulfate. Concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography (petroleum ether / ethyl acetate = 4:1) to obtain the yellow solid product IV-5 with a yield of 76%. Mp: 143.3 - 143.9 °C.

[0142] The obtained yellow solid product was used as a solvent with CDCl3 for 1 1H NMR test and 13 13C NMR test, and the obtained NMR data are characterized as follows:

[0143] The characterization data of the nuclear magnetic resonance hydrogen spectrum of Compound IV-5 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 9.03 (d, J = 9.0 Hz, 1H), 8.16 (d, J = 8.3 Hz, 1H), 7.78 (d, J = 6.3 Hz, 1H), 7.65 (t, J = 8.0 Hz, 1H), 7.49 (t, J = 8.0 Hz, 1H), 7.45 (d, J = 8.0 Hz, 1H), 7.42 (s, 1H), 7.38 (d, J = 8.0 Hz, 1H), 7.30 - 7.18 (m, 5H), 6.42 (s, 1H), 3.51 (s, 2H), 3.41 - 2.04 (m, 10H).

[0144] The characterization data of the nuclear magnetic resonance carbon spectrum of Compound IV-5 are as follows:13 C NMR (101 MHz, CDCl3) δ 154.30, 143.76, 143.36, 142.92, 140.10, 134.72, 133.32, 129.46, 129.35, 127.60, 127.53, 127.09, 126.90, 125.11, 125.04, 124.84, 122.91, 120.40, 119.21, 118.15, 107.13, 90.64, 89.58, 36.59.

[0145] Step 6: Preparation of photochromic compound IVa, the reaction formula is as follows:

[0146]

[0147] Add IV-5 (45 mg, 0.1 mmol), 1,1-(dimethoxyphenyl)-2-propyn-1-ol (27 mg, 0.1 mmol), toluene (5 mL) and 1 drop of dodecylbenzenesulfonic acid into a 50 mL round-bottom flask; heat in an oil bath to 40 °C and react for 3 h; after the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent; the residue is separated by silica gel column chromatography, and the eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 20:1) to obtain a yellow solid product IVa with a yield of 78%. Mp: 215.6 - 216.3 °C.

[0148] Use the obtained purple-red solid product as the solvent with CDCl3 and conduct 1 1H NMR test and 13 13C NMR test, and the obtained NMR data are characterized as follows:

[0149] The nuclear magnetic resonance hydrogen spectrum characterization data of compound IVa are as follows:

[0150] 1 1H NMR (400 MHz, Chloroform-d) δ 8.87 (d, J = 9.0 Hz, 1H), 8.20 (d, J = 8.4 Hz, 1H), 7.65 (s, 1H), 7.49 (t, J = 7.3 Hz, 2H), 7.37 (d, J = 7.0 Hz, 2H), 7.34 (d, J = 8.0 Hz, 1H), 7.23 (d, J = 4.4 Hz, 1H), 7.22 - 7.18 (m, 2H), 7.17 (s, 1H), 7.10 (d, J = 8.3 Hz, 4H), 6.60 (d, J = 8.3 Hz, 4H), 6.41 (d, J = 9.7 Hz, 1H), 5.92 (d, J = 9.7 Hz, 1H), 3.59 (s, 6H), 3.46 (s, 2H), 3.40 - 1.72 (m, 10H).

[0151] The characterization data of the carbon-13 nuclear magnetic resonance spectrum of Compound IVa are as follows:

[0152] 13 C NMR(101MHz,Chloroform-d)δ158.97,150.29,143.79,143.41,142.96,140.12,136.73,133.25,133.09,129.43,128.06,127.55,127.31,127.02,126.87,125.43,125.15,125.05,124.98,123.01,121.94,120.47,119.29,117.92,113.46,90.76,89.56,84.04,55.19,36.60.

[0153] Example 5: Preparation of Photochromic Compound V

[0154] Step 1: Synthesis of IV-1

[0155] Step 2: Synthesis of IV-2

[0156] Step 3: Preparation of Compound V-3. The reaction formula is as follows:

[0157]

[0158] Add IV-2 (500 mg, 1.2 mmol), 9,9-dihexyl-2-bromofluorene (270 mg, 1.5 mmol), bis(triphenylphosphine)palladium(II) chloride (43 mg, 0.06 mmol), copper(I) iodide (12 mg, 0.06 mmol), triphenylphosphine (16 mg, 0.06 mmol) and triethylamine (30 mL) into a 100 mL Schlenk reaction flask. Heat to 90 °C under nitrogen protection and react for 24 h. After the reaction is completed, wash with water, extract with dichloromethane (30 mL × 3), combine the organic phases and dry over anhydrous magnesium sulfate, and concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is petroleum ether (60 - 90 °C) to obtain the white solid product V-3 with a yield of 63%. Mp: 102.6 - 103.5 °C.

[0159] Use the obtained white solid product as the solvent with CDCl3 and perform 1 1H NMR test and 13 13C NMR test respectively. The nuclear magnetic data obtained are characterized as follows:

[0160] The characterization data of the proton nuclear magnetic resonance spectrum of Compound V-3 are as follows: 1HNMR(400MHz,Chloroform-d)δ8.49(d,J=8.3Hz,1H),8.33(d,J=8.4Hz,1H),7.76(d,J=7.9Hz,1H),7.72(d,J=8.0Hz,2H),7.68(d,J=8.0Hz,1H),7.65(s,1H),7.62(d,J=8.0Hz,1H),7.56(t,J=8.0Hz,1H),7.38-7.32(m,3H),6.84(d,J=8.0Hz,1H),4.05(s,3H),1.20-1.12(m,4H),1.11-1.03(m,10H),0.82-0.75(m,7H),0.75-0.57(m,5H).

[0161] The characterization data of the carbon nuclear magnetic resonance spectrum of Compound V-3 are as follows: 13 C NMR(101MHz,CDCl3)δ155.98,151.04,150.86,141.22,140.55,134.22,131.00,130.57,127.44,127.32,126.88,126.15,125.79,125.46,122.91,122.33,121.99,119.97,119.68,113.25,103.72,93.89,87.81,55.66,55.19,40.47,31.56,29.76,24.63,22.64,14.05.

[0162] Step 4: Preparation of Compound V-4. The reaction formula is as follows:

[0163]

[0164] Add Compound V-3(514mg,1mmol), boron dodecahydride bis(ethyl sulfide) complex(360mg,1.2mmol), and toluene(5mL) into a 100mL Schlenk tube. Under nitrogen protection, heat the reaction mixture in an oil bath to 100°C and react for 24h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is passed through an alkaline alumina column to remove sulfur-containing impurities, and then separated by silica gel column chromatography. The eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 10:1), and a yellow solid product V-4 is obtained with a yield of 12%. Mp: 188.7-189.3°C.

[0165] [[ID=,17]]Dissolve the obtained yellow solid product in CDCl3 as the solvent and perform 1 HNMR tests and 13 C NMR tests respectively. The nuclear magnetic data obtained are characterized as follows:

[0166] The characterization data of the 1H NMR spectrum of Compound V-4 are as follows: 1 H NMR(400MHz,Chloroform-d)δ9.04(d,J=9.0Hz,1H),8.24(d,J=8.0Hz,1H),7.87(d,J=8.0Hz,1H),7.65(d,J=8.0Hz,1H),7.55-7.51(m,1H),7.47(d,J=8.0Hz,1H),7.36-7.30(m,2H),7.25-7.19(m,4H),6.43(d,J=8.0Hz,1H),3.81(s,3H),3.67-1.82(m,10H),1.73-1.64(m,2H),1.60-1.50(m,3H),1.15-1.00(m,5H),0.96-0.88(m,4H),0.87-0.81(m,5H),0.80-0.75(m,7H).

[0167] The characterization data of the 13C NMR spectrum of Compound V-4 are as follows: 13 C NMR(101MHz,CDCl3)δ157.52,151.28,150.47,142.81,139.44,134.81,132.84,129.80,129.51,127.91,127.34,126.88,125.90,125.09,124.79,124.57,123.05,122.94,120.20,119.14,117.92,102.20,90.61,89.30,55.43,54.92,39.74,31.38,29.51,23.45,22.60,14.04.

[0168] Step 5: Preparation of Compound V-5. The reaction formula is as follows:

[0169]

[0170] Add compound V-4 (115 mg, 0.18 mmol) and dichloromethane (15 mL) to a 100 mL Schlenk tube. Under nitrogen protection, add boron tribromide (0.5 mL) in an ice bath. After one hour, bring the reaction to room temperature and react for 12 h. After the reaction is completed, add dichloromethane (20 mL) with a syringe, then slowly add water (20 mL) with a syringe. After the violent reaction stops, add water (40 mL). Extract with dichloromethane (20 mL × 2). Combine the organic phases and dry over anhydrous magnesium sulfate. Concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography (petroleum ether / ethyl acetate = 4:1) to obtain a yellow solid product V-5 with a yield of 76%. Mp: 152.8 - 153.4 °C.

[0171] Using the obtained yellow solid product as the solvent with CDCl3, conduct 1 1H NMR tests and 13 13C NMR tests, and the obtained NMR data are characterized as follows:

[0172] The characterization data of the 1H NMR spectrum of compound V-5 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 9.05 (d, J = 9.0 Hz, 1H), 8.16 (d, J = 8.4 Hz, 1H), 7.79 (d, J = 8.4 Hz, 1H), 7.65 (t, J = 7.9 Hz, 1H), 7.52 (d, J = 8.0 Hz, 1H), 7.46 (d, J = 7.6 Hz, 1H), 7.36 - 7.28 (m, 2H), 7.28 - 7.17 (m, 5H), 6.40 (d, J = 8.4 Hz, 1H), 5.56 (s, 1H), 4.04 - 2.05 (m, 10H), 1.75 - 1.64 (m, 2H), 1.61 - 1.51 (m, 2H), 1.15 - 1.00 (m, 5H), 0.98 - 0.90 (m, 4H), 0.89 - 0.82 (m, 5H), 0.81 - 0.69 (m, 8H).

[0173] The characterization data of the 13C NMR spectrum of compound V-5 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 154.04, 151.29, 150.52, 142.87, 139.41, 134.53, 133.26, 129.72, 129.60, 127.95, 127.54, 126.90, 125.11, 124.81, 124.78, 124.73, 122.95, 120.24, 119.12, 106.96, 90.70, 89.20, 54.94, 39.76, 31.38, 29.52, 23.46, 22.61, 14.07.

[0174]

[0175] Add V-5 (115 mg, 0.186 mmol), 1,1-(dimethoxyphenyl)-2-propyn-1-ol (50 mg, 0.186 mmol), toluene (10 mL) and 1 drop of dodecylbenzenesulfonic acid into a 50 mL round-bottom flask, heat in an oil bath to 40 °C, react for 3 h. After the reaction is completed, concentrate the reaction solution under reduced pressure to remove the solvent. The residue is separated by silica gel column chromatography, and the eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 40:1), obtaining a purple-red solid product Va, with a yield of 72%, Mp: 180.7 - 181.3 °C.

[0176] Use the obtained purple-red solid product as the solvent with CDCl3, and conduct 1 1H NMR test and 13 13C NMR test respectively, and the obtained NMR data are characterized as follows:

[0177] The characterization data of the 1H nuclear magnetic resonance spectrum of compound Va are:

[0178] 1 1H NMR (400 MHz, Chloroform-d) δ 8.95 (d, J = 9.0 Hz, 1H), 8.24 (d, J = 8.0 Hz, 1H), 7.65 (s, 1H), 7.59 - 7.54 (m, 2H), 7.41 (t, J = 8.0 Hz, 1H), 7.29 (s, 3H), 7.25 (s, 2H), 7.24 - 7.21 (m, 1H), 7.17 (d, J = 8.0 Hz, 4H), 6.68 (d, J = 8.0 Hz, 4H), 6.41 (d, J = 8.0 Hz, 1H), 5.95 (d, J = 8.0 Hz, 1H), 3.67 (s, 6H), 3.17 - 2.10 (m, 10H), 1.72 - 1.65 (m, 2H), 1.61 - 1.55 (m, 3H), 1.08 - 1.01 (m, 4H), 0.94 - 0.84 (m, 6H), 0.83 - 0.78 (m, 4H), 0.77 - 0.72 (m, 7H).

[0179] The characterization data of the 13C nuclear magnetic resonance spectrum of compound Va are:

[0180] 1313C NMR (101 MHz, Chloroform-d) δ 158.96, 151.37, 150.72, 150.20, 142.84, 139.44, 136.64, 133.06, 132.94, 129.70, 129.41, 128.09, 127.89, 127.24, 126.93, 125.32, 125.10, 125.07, 124.86, 123.088, 123.07, 121.99, 120.34, 119.02, 117.83, 113.47, 90.85, 89.22, 84.01, 55.20, 54.89, 39.61, 31.22, 29.47, 23.45, 22.60, 14.04.

[0181] Example 6: Photochromic Properties of Compounds Ia, IIa, IIIa, IVa, Va in Solution

[0182] Weigh specific amounts of the photochromic compounds Ia, IIa, IIIa, IVa, Va respectively and prepare 8×10 -5 mol / L dichloromethane solutions for each of them. Use an ultraviolet lamp (365 nm, 10 W) to irradiate the solutions for 5 s, 10 s, 15 s, 20 s, 25 s, 30 s to reach the saturated absorbance. Measure the time to reach the saturated absorbance, the maximum absorption wavelength, and the saturated absorbance through ultraviolet-visible absorption spectroscopy. After reaching the saturated absorbance, measure the ultraviolet absorption curve under dark conditions, and the fading half-life t 1 / 2 of the photochromic compounds in dichloromethane solution can be calculated by fitting with the biexponential formula. Figure 1 is the ultraviolet-visible absorption spectrum of the fading of Compound Ia in dichloromethane solution. Table 1 shows the photochromic properties of Compounds Ia, IIa, IIIa, IVa, Va in solution. As can be seen from Table 1, the maximum absorption wavelengths of the target compounds Ia, IIa, IIIa, IVa, Va in dichloromethane solution are 531 nm, 521 nm, 521 nm, 530 nm, 525 nm respectively. Irradiation makes the solution change from colorless to purplish red. The light response is rapid, the time to reach the saturated absorbance is 25 - 30 s, it has a high saturated light density value, and the fading rate is fast. The fading half-lives are 105 s, 35 s, 3 s, 10 s, 6 s respectively. It is worth noting that when Ar is a biphenyl group, the fading rate is very rapid.

[0183] Table 1 Photochromic Properties of Compounds Ia, IIa, IIIa, IVa, Va in Dichloromethane Solution (8×10 -5 mol / L)

[0184]

[0185] Note: [a] Photochromic optical density; [b] Fading rate is 3 s, exceeding the test range of existing ultraviolet-visible spectrometers.

[0186] Example 7: Fatigue resistance of compounds Ia, IIa, IIIa, IVa, Va in solution

[0187] Prepare dichloromethane solutions of Ia, IIa, IIIa, IVa, Va with a concentration of 8×10 -5 mol / L, irradiate with an ultraviolet lamp for 30 s to reach the maximum absorbance value, and then wait for 1 min to fade to colorless. Measure the maximum absorbance value and the absorbance value after fading for 1 min respectively. Repeat the measurement 10 times to obtain a color change cycle curve graph, as Figure 2 shown as the fatigue resistance test graph of Ia in solution.

[0188] As can be seen from the appendix Figure 2 After 10 cycles, the maximum absorbance value of Ia in solution hardly changes, indicating that Ia has good fatigue resistance. Similarly, analyze the fatigue resistance test graphs of IIa, IIIa, IVa, Va in solution, and the maximum absorbance remains above 90%. We can speculate that the boron cluster increases the spatial volume of the compound molecule, provides more free space for the ring-opening and ring-closing of naphthopyran, increases the distance between molecules, and reduces the intermolecular interaction force between the ring-opened molecules. Therefore, the naphthopyran compound can undergo the photo-isomerization process repeatedly for many times, and the fatigue resistance is greatly improved.

[0189] Example 8: Fluorescence intensity change of compounds Ia, IIa, IIIa, IVa, Va in solution with illumination time

[0190] Prepare dichloromethane solutions of Ia, IIa, IIIa, IVa, Va with a concentration of 8×10 -5 mol / L, irradiate the solution with an ultraviolet lamp (365 nm, 10 W) for 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, and measure its steady-state fluorescence spectrum, as Figure 3 shown as the fluorescence emission spectrum of Ia at different illumination times.

[0191] As can be seen from the appendix Figure 3 It can be seen that the maximum emission wavelength of Ia at different illumination times is 680 nm, the fluorescence intensity decreases with the increase of illumination time, and when the saturation absorbance is reached at 30 s, the fluorescence intensity no longer decreases. Combining with the fluorescence emission spectra of IIa, IIIa, IVa, Va at different illumination times, it can be concluded that the fluorescence intensity of the compound in solution decreases with the increase of illumination time. After 30 s of illumination, the proportion of the ring-opened form of naphthopyran reaches the maximum. Since the molecule consumes molecular energy during the ring-opening process, the fluorescence intensity decreases and reaches the lowest value.

[0192] Example 9: Fluorescence Emission Spectrum of Compound Ia in Thin Film State

[0193] Weigh polymethyl methacrylate (400 mg) and add it to a 50 mL round-bottom flask. Add 10 mL of chloroform, stir to dissolve, and heat to 50 °C. When all the solids are dissolved and the solution is transparent, weigh the yellow solid compound Ia (8 mg) and add it to the round-bottom flask. After heating and stirring for 1 min, pour the solution in the flask into a cylindrical quartz mold (Ф = 7.5 cm), and place it in the open air away from light. Wait until all the solvent has evaporated, remove the mold, and cut the prepared thin film into small square pieces of size (2 cm × 2 cm). Use a steady-state fluorescence spectrometer to measure its emission spectrum (attached Figure 4 ). As attached Figure 4 shown, the maximum emission spectrum of compound Ia in thin film state is 610 nm.

[0194] Preparation of Comparative Compound CB0

[0195] The preparation route of the compound CB0 without carborane is shown in the following reaction formula:

[0196]

[0197] Weigh 2-2a (1.0 g, 4.0 mmol) and add it to a 100 mL Schlenk tube. After evacuating and replacing with nitrogen three times, add dichloromethane (10 mL). Slowly add boron tribromide (1.0 mL) to the reaction flask in an ice bath. After one hour, bring the reaction to room temperature and react for 12 h. After the reaction is complete, add dichloromethane (20 mL) with a syringe, then slowly add water (20 mL) with a syringe. After the reaction is no longer vigorous, add water (40 mL) again. Extract the aqueous phase with dichloromethane (20 mL × 2), combine the organic phases and dry them with anhydrous magnesium sulfate. Filter to obtain the filtrate, rotary evaporate the solvent, and separate the residue obtained by silica gel column chromatography (petroleum ether / ethyl acetate = 10:1) to obtain a colorless liquid product 2-2a,a with a yield of 58%.

[0198] The characterization data of the nuclear magnetic resonance hydrogen spectrum of compound 2-2a,a are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 8.47 - 8.37 (m, 1H), 8.27 - 8.18 (m, 1H), 7.68 - 7.58 (m, 4H), 7.57 - 7.51 (m, 1H), 7.43 - 7.33 (m, 3H), 6.83 - 6.73 (m, 1H), 5.64 - 5.52 (s, 1H).

[0199] The characterization data of the nuclear magnetic resonance carbon spectrum of compound 2-2a,a are as follows: 1313C NMR (101 MHz, CDCl3) δ 152.2, 134.62, 131.52, 130.9, 128.4, 128.1, 127.4, 126.3, 125.8, 124.2, 123.8, 122.0, 113.5, 108.5, 92.8, 87.7.

[0200] Mass spectrometry characterization data of compound 2-2a,a: HRMS (ESI) Calcd. for C18H12O [M+H]+: 243.0888, found: 243.0811.

[0201] Weigh 2-2a,a (500 mg, 2.0 mmol) and 1,1-(dimethoxyphenyl)-2-propyn-1-ol (600 mg, 2.2 mmol) again, add them into a 100 mL round-bottom flask, add toluene (20 mL) and 1 drop of dodecylbenzenesulfonic acid.

[0202] Heat the reaction solution in an oil bath to 40 °C and react for 3 h. After the reaction is completed, rotary evaporate the toluene. The residue is separated by silica gel column chromatography, and the eluent is a mixed solvent of petroleum ether / ethyl acetate (the volume ratio of petroleum ether / ethyl acetate is 4:1) to obtain a purple-red solid product CB0 with a yield of 81%. m.p: 78.8 - 79.2 °C.

[0203] 1H NMR characterization data of compound CB0 are as follows: 1 1H NMR (400 MHz, Chloroform-d) δ 8.36 - 8.28 (m, 2H), 7.59 (d, J = 7.3 Hz, 2H), 7.48 (d, J = 7.5 Hz, 2H), 7.42 - 7.32 (m, 8H), 6.83 (d, J = 8.4 Hz, 4H), 6.68 (d, J = 9.7 Hz, 1H), 6.14 (d, J = 9.7 Hz, 1H), 3.75 (s, 6H).

[0204] 13C NMR characterization data of compound CB0 are as follows: 13 13C NMR (101 MHz, CDCl3) δ 159.0, 148.6, 137.2, 134.5, 131.5, 129.2, 128.4, 128.24, 128.0, 127.2, 126.2, 126.1, 124.7, 123.8, 122.9, 122.4, 115.3, 113.5, 113.1, 92.8, 87.7, 83.4, 55.3.

[0205] Mass spectrometry characterization data of compound CB0: HRMS(ESI) Calcd. for C 35H 26O 3[M+H]+: 495.1882, found: 495.1949.

[0206] Photochromic properties of compound CB0 in Comparative Example 2

[0207] (1) Study on the color change rate of CB0 in solution

[0208] Using dichloromethane as the solvent, a test solution of CB0 compound with a concentration of 8×10 -5 mol / L was prepared. The absorbance of the solution was measured using a UV spectrophotometer at different illumination times to analyze the response time to reach the photochemical equilibrium. In the experiment, the solution was irradiated with 365 nm UV light for 0 s, 5 s, 10 s, 15 s, 20 s, 25 s, and 30 s respectively to reach the saturated absorbance. The time to reach the saturated absorbance, the maximum absorption wavelength, and the saturated absorbance were measured by UV-visible absorption spectroscopy. After reaching the saturated absorbance, the UV absorption curve was measured under dark conditions, and the fading half-life t 1 / 2 .

[0209] The maximum absorption wavelength of CB0 in dichloromethane solution is 541 nm; the maximum absorption peaks of compounds Ia, IIa, IIIa, IVa, and Va containing boron clusters show a blue shift relative to CB0 without boron cluster groups, indicating a change in the conjugation degree of the molecule. This is because the introduction of the carbaborane causes some aromatic groups to rotate intramolecularly from the original plane, making the whole molecule more three-dimensional. The solution changes from colorless to bright purple-red with high chroma.

[0210] (2) Study on the fading rate of CB0 in solution

[0211] Based on obtaining the optimal concentration of the compound solution and the illumination time to reach the saturated absorbance, the fading performance of the solution was experimentally investigated. Using dichloromethane as the solvent, a solution with a concentration of 8×10 -5 mol / L was prepared. The solution was irradiated with the same UV light source for 30 s, and then the UV absorption curve was measured every 15 s under dark conditions. The fading half-life of CB0 in dichloromethane solution is 150 s; the fading rate of IIIa relative to CB0 is increased by more than 50 times.

[0212] (3) Study on fatigue resistance of CB0 in solution

[0213] Compound CB0 was prepared into a solution with a concentration of 8×10 -5The dichloromethane solution with a concentration of [[mol / L]] was used to measure the maximum absorbance under UV light irradiation for 30 s and in the dark for 1 min in sequence. After 10 cycles, the maximum absorbance value and the absorbance value after 1 min of fading were measured to plot the corresponding cycle curve for fatigue resistance testing. As the number of light irradiation cycles increased, the maximum absorbance of CB0 decreased successively and finally dropped to about 30% of the initial maximum absorbance. For Ia, after 10 cycles of cyclic light irradiation, the maximum absorbance remained above 90%. It can be seen that due to the addition of the boron cluster group, the naphthopyran compound can undergo the photo-isomerization process repeatedly for many times, and the fatigue resistance is greatly improved.

[0214] The preferred embodiments of the present invention have been described in detail above, but the above content is only the preferred embodiments of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention shall fall within the scope covered by the patent of the present invention.

Claims

1. A boron cluster naphthopyran photochromic compound, characterized in that, The compound has the structure shown in Formula I: wherein Ar is any one of, wherein * represents a linking site.

2. The preparation method of the boron cluster naphthopyran photochromic compound according to claim 1, characterized in that: The method comprises the following steps: (1): 1-Bromo-4-methoxynaphthol reacts with in a basic solvent under the catalysis of a palladium catalyst to form Compound 1. The reaction formula is as follows: (2): Compound 1 reacts with bis(ethylthio)decaborane(12) to generate Compound 2, and the reaction formula is as follows: (3): Compound 2 reacts under the action of boron tribromide to generate Compound 3, and the reaction formula is as follows: (4): Compound 3 reacts with 1,1-(diaryl)-2-propyn-1-ol under the catalysis of an organic acid to form a photochromic compound I. The reaction formula is as follows: In the above reaction formulas of steps (1)-(4), Ar is any one of them, where * represents the connection site.

3. The preparation method of the boron cluster naphthopyran photochromic compound according to claim 2, wherein in step (1), the palladium catalyst used is tetrakis(triphenylphosphine)palladium, the cocatalyst is copper(I) iodide, the basic solvent is triethylamine, the reaction temperature is 80-90 °C, and the reaction time is 18-24 h; in step (2), toluene is used as the aromatic solvent, the reaction temperature is 100-120 °C, and the reaction time is 20-24 h; in step (3), boron tribromide is used as the catalyst, the reaction solvent is dichloromethane or chloroform, the reaction temperature is 0 °C, and the reaction time is 16-20 h; in step (4), the organic acid used is dodecylbenzenesulfonic acid, the reaction solvent is at least one of toluene or xylene, the reaction temperature is 40-50 °C, and the reaction time is 3-6 h.

4. The preparation method of the boron cluster naphthopyran photochromic compound according to claim 2, wherein in step (1), the molar ratio of 1-bromo-4-methoxynaphthol to tetrakis(triphenylphosphine)palladium is 1:0.05, the molar ratio of 1-bromo-4-methoxynaphthol to phenylacetylene is 1:(2.2-2.5), and the molar ratio of 1-bromo-4-methoxynaphthol to copper(I) iodide is 1:0.05; in step (2), the molar ratio of Compound 1 to bis(ethylthio)decaborane complex is 1:1.2; in step (3), the molar ratio of Compound 2 to boron tribromide is 1:(2.5-3); in step (4), the molar ratio of Compound 3 to 1,1-(diaryl)-2-propyn-1-ol is 1:(1-1.3).

5. An intermediate for preparing a boron cluster naphthopyran photochromic compound, characterized in that, The intermediate has the following structure: wherein Ar is any one of, wherein * represents a linking site.

6. An intermediate for preparing a boron cluster naphthopyran photochromic compound, characterized in that, The intermediate has the following structure: wherein Ar is any one of, wherein * represents a linking site.

7. The application of the boron cluster naphthopyran photochromic compound intermediate according to any one of claims 5 or 6 in the preparation of the boron cluster naphthopyran photochromic compound.

8. The application of the boron cluster naphthopyran photochromic compound intermediate according to any one of claims 5 or 6 in lenses, smart windows, fashion decorations, and dye-sensitized solar cells.

9. The application of the boron cluster naphthopyran photochromic compound according to claim 1 in lenses, smart windows, fashion decorations, and dye-sensitized solar cells.

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