A conjugated polymer containing 9-phenoxy-10-phenylanthracene structural unit and preparation method and application thereof

Abstract

The application discloses a conjugated polymer containing a 9-phenoxy-10-phenyl anthracene structural unit and a preparation method and application thereof. The conjugated polymer takes an asymmetrically modified large conjugated anthracene unit as a main unit, and connects a phenyl group, a tetraphenyl ethylene group, a fluorene group, a carbazole group and other electron-rich donor units with good hole transport and electron transport performance through an alkyne group to jointly construct a D-pi-A type conjugated polymer with good fluorescence performance. The conjugated polymer has good solubility, chemical stability and good photoluminescence performance, and can be widely used as a fluorescent material or a fluorescent probe.

Description

Technical Field

[0001] This invention relates to a conjugated polymer material, particularly to a conjugated polymer containing 9-phenoxy-10-phenylanthracene structural units with fluorescent properties, and also to its preparation method and application, belonging to the field of functional polymer materials technology. Background Technology

[0002] Anthracene is a common blue fluorescent material composed of three fused benzene rings. However, its large aromatic ring conjugated system easily leads to intermolecular aggregation and crystallization, significantly reducing its application value in the field of luminescent materials. Therefore, current research mainly focuses on structural modification of anthracene to reduce intermolecular aggregation and improve its thermal stability and crystallinity. Polyanthracene is a polymeric fluorescent material with good thermal stability, easy processing and molding, and adjustable emission color, thus attracting considerable attention from researchers.

[0003] The literature (Chen L, Chen KZ, Yao RJ. From blue fluorescence to red fluorescence: Solid-state oxidative coupling polymerization of fluorene and anthracene or naphthalene[J]. Materials Chemistry and Physics, 2022, 285: 126083.) discloses the synthesis of a series of fluorene-anthracene copolymers (PFA) and fluorene-co-naphthalene copolymers (PFN) via solid-state oxidative coupling polymerization using FeCl3 as an oxidant (see reaction formula 1). The fluorene-anthracene copolymers were then analyzed by FT-IR and... 1 ¹H NMR characterization of the copolymers revealed a random structure composed of fluorene units and either 9,10-anthracene units or 1,4-linked naphthalene units. All copolymers exhibited good thermal stability, and their optical properties could be tuned by adjusting the ratio of fluorene to anthracene and naphthalene. Furthermore, the polymers emitted light in a range from blue to red, which can be attributed to variations in the effective conjugation length of individual polymers and the formation of polymer aggregates. These unique properties make PFA a potential candidate for applications in optoelectronics.

[0004] Reaction 1:

[0005] The literature (Kitagawa Y, Naito A, Fushimi K. Bright sky-blue fluorescence with high color purity: Assembly of luminescent diphenyl-anthracene lutetium-based coordination polymer[J]. Rsc Advances, 2021, 11: 6604-6606.) discloses the assembly of a polymer coordinated with diphenylanthracene and the metal ion lutetium (see reaction formula 2), demonstrating that the lutetium-coordinated diphenylanthracene derivative polymer exhibits blue fluorescence with high color purity. Observation reveals that its high color purity is based on the close-packed crystal structure of the coordination polymer with multiple CH–F interactions.

[0006] Reaction 2:

[0007] The literature (Park HY, Geum N, Ko J. Chemiluminescent properties of polymeric blue fluorophores containing diphenylanthracene unit[J]. Dyes and Pigments, 2002, 54: 59-66.) discloses the synthesis of a novel conjugated and non-conjugated alternating block copolymer 1 containing 9,10-diphenyl-2-chloroanthracene in the main chain via the Williamson method (see reaction formula 3). Its luminescent properties, including chemiluminescence, were studied by UV-Vis absorption spectroscopy and compared with the model fluorophore 9,10-bis(4-methoxyphenyl)-2-chloroanthracene. The polymer exhibits blue photoluminescence in solution up to approximately 430 nm. The polymer shows good solubility in common organic solvents and moderate stability under peroxide oxidation conditions, but its fluorescence decay time is slightly short; chemiluminescence is visible to the naked eye and persists for more than 12 hours.

[0008] Reaction 3:

[0009] Summary of the Invention

[0010] In view of the shortcomings of the existing technology, the first objective of the present invention is to provide a conjugated polymer containing 9-phenoxy-10-phenylanthracene structural units, which has good solubility, chemical stability and good photoluminescence properties, and can be widely used as a fluorescent material or fluorescent probe.

[0011] The second objective of this invention is to provide a method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit. This method is simple, uses mild conditions, is low in cost, and is conducive to large-scale production.

[0012] A third objective of this invention is to provide an application of a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, which exhibits a maximum emission peak in the blue light region of approximately 410–430 nm, making it suitable for use as a photofluorescent material. Furthermore, it selectively recognizes Fe in solution systems. 3+ It exhibits fluorescence quenching and can be used as a detector for Fe. 3+ The fluorescent probe is used.

[0013] To achieve the above-mentioned technical objectives, the present invention provides a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, which has the following repeating structural units:

[0014]

[0015] in,

[0016] Ar is selected from the following structural units:

[0017]

[0018] The conjugated polymer containing 9-phenoxy-10-phenyl anthracene structural units of the present invention is a D-π-A type polymer fluorescent material. It uses asymmetrically modified anthracene units as the main unit and connects electron-rich donor units such as phenyl, tetraphenylethylene, fluorene, and carbazole with good hole and electron transport properties through alkyne groups to jointly construct a D-π-A type conjugated polymer with good fluorescence properties.

[0019] The conjugated polymer of the present invention, containing 9-phenoxy-10-phenylanthracene structural units, has asymmetrically modified anthracene units. The asymmetrically modified large conjugated system significantly enhances its intramolecular charge transfer. Simultaneously, the introduction of an alkynyl group into the large conjugated system, which possesses electron-accepting ability, increases the electron-withdrawing ability of the entire anthracene unit when linked to the asymmetrically modified large conjugated system anthracene unit, further improving intramolecular charge transfer and thus contributing to its fluorescence properties. Furthermore, the alkynyl group acts as a π-bridge, connecting the asymmetrically modified anthracene host unit with strong electron-donating units such as TPE and fluorene, further enhancing the polymer's thermal stability and high quantum yield of blue light emission. In addition, the asymmetrically modified anthracene unit introduces ether-oxygen bonds, resulting in an asymmetric polar structure. The introduction of n-octyl groups into the carbazole and fluorene units helps improve the solubility of the conjugated polymer and reduces its crystallinity, facilitating processing.

[0020] This invention also provides a method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, comprising the following steps:

[0021] 1) 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene undergoes a diazotization-iodination tandem reaction with potassium iodide in the presence of NaNO2 and p-toluenesulfonic acid to give 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene.

[0022] 2) 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene undergoes a Sonogashira coupling reaction with trimethylsilylacetylene under the catalysis of PdCl2(PPh3)2 and CuI, followed by a detrimethylsilylation reaction under the action of K2CO3 to give 9-(4-ethynylphenoxy)-10-(4-ethynylphenyl)anthracene;

[0023] 3) 9-(4-ethynylphenoxy)-10-(4-ethynylphenyl)anthracene was coupled with a dihaloaryl monomer via Sonogashira polymerization under the catalysis of PdCl2(PPh3)2 and CuI to obtain the product.

[0024] The dihaloaryl monomers are selected from:

[0025]

[0026] X is bromine or iodine.

[0027] As a preferred embodiment, in step 1), 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is added to a solution containing methylbenzenesulfonic acid, cooled to below 0°C, and then a mixed solution containing NaNO2 and KI is added. The reaction is carried out at -5 to 5°C for 40 to 80 minutes. The solution containing methylbenzenesulfonic acid is obtained by adding p-methylbenzenesulfonic acid to a mixed solution of acetonitrile and water, and stirring at 60 to 70°C for 0.4 to 0.6 hours.

[0028] As a preferred embodiment, the molar ratio of methylbenzenesulfonic acid to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.5-3.5):1.

[0029] As a preferred embodiment, the molar ratio of NaNO2 to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.0-2.5):1.

[0030] As a preferred embodiment, the molar ratio of KI to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.0-2.5):1.

[0031] As a preferred embodiment, in step 2), the molar ratio of 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene to trimethylsilylacetylene is 1:(2-3).

[0032] As a preferred embodiment, the Sonogashira coupling reaction is carried out at a temperature of 65–75°C for 8–12 hours.

[0033] As a preferred embodiment, the conditions for the detrimethylsilylation reaction are: at room temperature, the reaction is carried out for 4 to 6 hours.

[0034] As a preferred embodiment, the conditions for the Sonogashira coupling polymerization are: reaction at 75–85°C for 24–48 h.

[0035] This invention also provides an application of a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, which is used as a fluorescent material. This conjugated polymer exhibits an absorption peak in the 302–372 nm ultraviolet region in solutions such as THF, and a maximum intensity emission peak around the 410–430 nm blue light region, indicating that it possesses excellent photofluorescence properties and can be used as a fluorescent material.

[0036] This invention also provides an application of a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, which serves as a Fe... 3+ Applications of fluorescent probes for detecting Fe in complex metal ion solution systems. 3+ It has selective recognition function (e.g., Cu) 2+ Zn 2+ Na + Ba 2+ K + Ca 2+ Fe 3+ (etc.), while Fe 3+ It can quench the fluorescence of conjugated polymers in solution systems, thus serving as a Fe... 3+ Application of fluorescent probes for detection.

[0037] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0038] 1) The conjugated polymers of the present invention exhibit good room temperature solubility in conventional organic solvents such as THF, DCM, and DMF, which gives them good processing performance.

[0039] 2) The fluorescence emission spectrum of the conjugated polymer of the present invention in THF solution shows that there is a maximum intensity emission peak in the range of about 410 to 430 nm, which can be used as a fluorescent material.

[0040] 3) The conjugated polymer of the present invention has good chemical and thermal stability, with a 10% thermal weight loss temperature of 350℃ to 492℃, which can meet the application requirements under different temperature environments.

[0041] 4) The band gap values ​​of the conjugated polymers of the present invention are all around 3.0 eV, which gives them good electrochemical performance.

[0042] 5) The conjugated polymer of the present invention can recognize Fe in THF solution. 3+ Simultaneously, it is accompanied by fluorescence quenching and exhibits strong anti-interference properties. Cu 2+ Zn 2+ Na + Ba 2+ K + Ca 2+ Metal ions do not cause fluorescence quenching and can be used as Fe 3+ The fluorescent probe used for detection.

[0043] 6) The method for preparing the conjugated polymer of the present invention is simple, mild, and low in cost, which is conducive to large-scale production. Attached Figure Description

[0044] Figure 1 For P8 1 H NMR spectrum.

[0045] Figure 2 For P8 13 C10 NMR spectrum.

[0046] Figure 3 The image shows the FTIR spectrum of P8.

[0047] Figure 4 For P9 1 H NMR spectrum.

[0048] Figure 5 The image shows the FTIR spectrum of P9.

[0049] Figure 6 For conjugated polymers P9 to P12 in THF solution (1×10⁻⁶) –5 Fluorescence emission spectrum of (mol / L).

[0050] Figure 7 For conjugated polymers P9 to P12 in THF solution (1×10⁻⁶) -5 PL spectrum (mol / L).

[0051] Figure 8 For conjugated polymers P9 to P12 in different polar solvents (1×10⁻⁶) –5 Fluorescence emission spectrum of (mol / L).

[0052] Figure 9 The CV curves are for conjugated polymers P9 to P12 in dry DCM.

[0053] Figure 10 The TGA curves of conjugated polymers P9 to P12 under nitrogen atmosphere are shown.

[0054] Figure 11 The fluorescence spectra of conjugated polymers P9–P12 in tetrahydrofuran solution containing metal ions are shown. A 10 μL solution with a concentration of 1 × 10⁻⁶ is used. –2 mol / L metal hydrochloride MCl m (M=Cu 2+ Zn 2+ Na + Ba 2+ K + Ca 2+ Fe 3+ The fluorescence intensity of each sample was tested.

[0055] Figure 12 The blank sample of conjugated polymer P9 in tetrahydrofuran solution without any metal ions and the sample solutions with different metal ions added respectively (from left to right: blank sample, Cu). 2+ Zn 2+ Na + Ba 2+ K + Ca 2+ Fe 3+ (Photo taken under 365nm ultraviolet light).

[0056] Figure 13 For different Fe 3+ The fluorescence spectrum and fluorescence emission coefficient variation curve of P12 in tetrahydrofuran at a concentration of 1000 ppm were obtained in 1 mL of THF solution of polymer P12 (1 × 10⁻⁶). –5 Add 10 μL of (0.005~0.04)×10 to each of the following solutions: mol / L. –2 Fe in the concentration range of mol / L 3+ Solution. Detailed Implementation

[0057] The following specific embodiments are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention.

[0058] Unless otherwise specified, the chemical raw materials involved in the following specific embodiments are all conventionally obtained through commercial means in the prior art.

[0059] The performance testing methods used in the following examples are all conventional, and the specific testing instruments are: nuclear magnetic resonance spectrometer (Bruker Vance, Switzerland); Fourier transform infrared spectrometer (Perkin-Elmer Spectrum One FTIR spectrometer, USA); steady-state and transient fluorescence spectrometer (Edinburgh Ltd, UK); thermogravimetric analysis (Shimadzu DT-40 thermal analyzer); electrochemical workstation (Shanghai Chenhua Instrument Co., Ltd.); and ultraviolet-visible absorption spectrometer (Hitachi).

[0060] The specific reaction formulas involved in the following specific embodiments are as follows:

[0061]

[0062]

[0063] M1 and M2 were synthesized based on existing literature:

[0064] Preparation of 9-(4-nitrophenoxy)-10-(4-nitrophenyl)anthracene M1:

[0065] Anthrone (5.82 g, 30 mmol), p-fluoronitrobenzene (9.31 g, 66 mmol), potassium tert-butoxide (6.72 g, 60 mmol), and 60 mL of DMF were added to a 100 mL three-necked flask. The reaction was carried out at 120 °C for 36 h under a nitrogen atmosphere. After the reaction was stopped, the reaction solution was cooled to room temperature and slowly poured into 200 mL of ice water, precipitating a brownish-yellow solid. The crude product was filtered to obtain the crude product, which was then dried and separated by column chromatography to obtain 7.13 g of a yellow solid, with a yield of 80%. 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.50 (d, J = 8.4Hz, 2H), 8.20 (d, J = 9.2Hz, 2H), 8.07 (d, J = 8.4Hz, 2H), 7.69 (d ,J=8.4Hz,2H),7.61(d,J=8.8Hz,2H),7.49(t,J=7.0Hz,2H),7.44(t,J=7.6Hz,2H),6.99(d,J=9.2Hz,2H). 13 CNMR (100MHz, CDCl3): δ (ppm) = 164.2, 147.6, 145.3, 144.8, 142.7, 130.2, 126.9, 126.7, 126.3, 126.1, 123.9, 121.8, 115.6.

[0066] Preparation of 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene M2:

[0067] Under a nitrogen atmosphere, M1 (3.76 g, 8.6 mmol), Pd / C (0.31 g), hydrazine hydrate (6.5 mL), and ethanol (80 mL) were added to a 250 mL three-necked flask, and the mixture was reacted at 70 °C for 24 h. After the reaction was complete, the mixture was filtered while hot, the filter cake was dissolved with DCM, concentrated, and the residue was separated by column chromatography (PE / EA as eluent, V / V = 25:1) to give 3.31 g of a yellow solid, with a yield of 80%. 1 HNMR (400 MHz, DMSO): δ (ppm)=8.08(d,J=8.4Hz,2H),7.77(d,J=8.7Hz,2H),7.44(dt,J=14.0,6.6Hz,4H),7.09(d,J=8 .2Hz,2H),6.83(d,J=8.3Hz,2H),6.55(s,2H),6.49(d,J=8.9Hz,2H),5.31(s,2H),4.71(s,2H). 13 C NMR (100MHz, DMSO): δ (ppm) = 151.97, 148.69, 145.50, 145.38, 143.92, 135.42, 13 2.15,131.24,127.56,126.05,125.94,124.77,122.60,115.90,115.49,114.39.

[0068] Example 1

[0069] Preparation of 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene M3:

[0070] A mixed solution of p-toluenesulfonic acid (1.55 g, 9 mmol), acetonitrile, and water was added to a 100 mL three-necked flask. The mixture was reacted at 60 °C for 0.5 h. Then, M2 (1.13 g, 3 mmol) was added, and the mixture was cooled to 0 °C. A solution of NaNO2 (0.97 g, 6 mmol), KI (0.41 g, 6 mmol), and H2O was added, and the mixture was reacted at 0 °C for 1 h. The temperature was then raised to room temperature, and the reaction was continued for 2 h. After the reaction was complete, the reaction solution was poured into 150 mL of water, and NaHCO3 was added to adjust the pH of the mixture to weakly alkaline. Then, an appropriate amount of Na2S2O3 was added, and the mixture was stirred for 10 min. The mixture was extracted with DCM, and the organic phases were combined and dried over anhydrous magnesium sulfate to remove the solvent. The product was purified by column chromatography using a hexane / DCM mixed solvent (V / V = 100 / 1) as the eluent to obtain 0.72 g of a white powder, with a yield of 60%. 1H NMR (400MHz, CDCl3): δ (ppm) = 8.08 (d, J = 8.5Hz, 2H), 7.93 (d, J = 8.1Hz, 2H), 7.67 (d J=8.6Hz,2H),7.52(d,J=8.7Hz,2H),7.39(dt,J=15.0,6.7Hz,4H),7.21(d J=8.1Hz,2H),6.65(d,J=8.7Hz,2H),5.31(s,2H),4.71(s,2H). 13 C NMR (100MHz, CDCl3): δ (ppm) = 160.03, 145.11, 138.66, 137.98, 137.71, 133.59, 133.37,130.74,126.84,125.98,125.92,124.23,122.25,117.75,93.56,84.24.

[0071] Example 2

[0072] Preparation of 9-(4-ethynylphenoxy)-10-(4-ethynylphenyl)anthracene P8:

[0073] In a nitrogen atmosphere, M3 (1.2 g, 2 mmol), PdCl2(PPh3)2 (36.1 mg, 0.05 mmol), and CuI (38.09 mg, 0.2 mmol) were added to a 100 mL three-necked flask. Then, 20 mL of a mixed solution of triethylamine and tetrahydrofuran (V / V = 30 / 11) was added, and the reaction was carried out at 70 °C for 1 h. Trimethylsilylacetylene (0.39 g, 4 mmol) was then added, and the reaction was continued at 70 °C for 10 h. The reaction was stopped, the reaction solution was cooled to room temperature, the solvent was removed, and K2CO3 and THF (15 mL) were added. The reaction was carried out at room temperature for 5 h. After stopping the reaction, the reaction solution was poured into 150 mL of water, extracted with DCM, and the organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was removed. Using a hexane / DCM mixed solvent (V / V = 20 / 1) as the eluent, the solution was purified by column chromatography to obtain 0.41 g of a pale yellow powder, with a yield of 41%. 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.00 (d, J = 8.2Hz, 2H), 7.64 (d, J = 7.8Hz, 2H), 7.58 (d, J = 8.6Hz, 2H), 7.34 (d, J = 7 .7Hz,2H),7.30(dd,J=8.0,4.5Hz,4H),7.26(d,J=7.0Hz,2H),6.74(d,J=8.6Hz,2H),3.10(s,1H),2.89(s,1H). 13C NMR (100MHz, CDCl3): δ (ppm) = 160.44, 145.08, 139.19, 134.05, 133.95, 132.27, 131.51, 130.73,126.87,125.94,125.89,124.27,122.26,121.63,115.64,115.47,83.53,83.35.

[0074] Figures 1 to 3 These are the proton, carbon, and FTIR spectra of the small molecule P8. Figure 1 In the proton NMR spectrum, singlets appear at 3.100 ppm and 2.893 ppm, which are characteristic peaks of ≡C-H. Compared to alkene hydrogens, alkyne hydrogens are shifted at a higher field. The proton shifts of the aromatic rings are all in the range of 6–9 ppm, and the number and shifts of hydrogen atoms in the spectrum are consistent with the expected hydrogen atoms.

[0075] exist Figure 2 In the carbon spectrum, characteristic C≡C peaks can be seen at chemical shifts of 83.55 ppm and 83.35 ppm, while other peaks at chemical shifts of 110 ppm to 165 ppm are attributed to carbons on the aromatic ring.

[0076] exist Figure 3 In the FTIR spectrum, at 2108 cm⁻¹ –1 The peak observed at 3292 cm⁻¹ is the absorption peak of the stretching vibration of C≡C. –1 The peak appearing at 1592 cm⁻¹ is the absorption peak due to the stretching vibration of the ≡C-H bond. –1 1500cm –1 1437cm –1 The absorption peak that appears is the stretching vibration peak of the carbon-carbon double bond in the aromatic ring skeleton, at 833 cm⁻¹. –1 773cm –1 718cm –1 and 707cm –1 Absorption peaks of the =C-H stretching vibration on the aromatic ring at the same location.

[0077] According to the analysis, the structures shown in the three spectra above are consistent with the structural characteristics of compound P8.

[0078] Example 3

[0079] The synthesis of dihaloaryl monomers was performed according to existing literature:

[0080] Preparation of 1,2-bis(4-bromophenyl)-1,2-diphenylethylene 1b:

[0081]

[0082] Preparation method: Under nitrogen atmosphere, 4-bromobenzophenone (6.53 g, 25 mmol) and zinc powder (3.25 g, 50 mmol), and THF solution (100 mL) were added to a 250 mL three-necked flask. The reaction solution was cooled to 0 °C in an ice bath, and then 2.8 mL of TiCl4 (4.74 g, 25 mmol) was slowly added dropwise. After the addition was complete, the reaction solution was heated to 25 °C and reacted for 1 h, then heated to 70 °C and reacted for 12 h. After the reaction was completed, the reaction solution was slowly poured into a 10% K2CO3 aqueous solution, filtered, and the filtrate was extracted with DCM. The organic phases were combined and washed three times with a saturated sodium chloride solution. After drying with anhydrous magnesium sulfate, the solvent was removed. Using n-hexane as the eluent, the solution was purified by column chromatography to obtain a white solid 1b, with a yield of 65%. 1 H NMR (400MHz, CDCl3): δ (ppm) = 7.29–7.20 (m, 4H), 7.17–7.09 (m, 6H), 7.03–6.96 (m, 4H), 6.91–6.85 (m, 4H).

[0083] Preparation of 3,6-dibromo-N-n-octylcarbazole 1c:

[0084]

[0085] Preparation method: In a 250 mL three-necked flask, 3,6-dibromocarbazole (8.13 g, 25 mmol), 50% potassium hydroxide solution (12 mL), tetrabutylammonium bromide (2.27 g, 7 mmol), and toluene (120 mL) were added sequentially. The mixture was reacted at 110 °C for 2 h. Then, 1-bromooctane (2.28 mL, 30 mmol) was added dropwise, and the reaction was continued for 30 h. After the reaction was stopped, the reaction solution was cooled to room temperature, poured into 200 mL of water, extracted with DCM, and the organic phases were combined. The solvent was removed by drying over anhydrous magnesium sulfate. The solution was purified by column chromatography using n-hexane as the eluent to give a white solid 1c, with a yield of 63%. 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.13 (d, J = 1.7Hz, 2H), 7.55 (dd, J = 8.7, 1.8Hz, 2H), 7.25 (s, 2H), 4 .23(t,J=7.2Hz,2H),1.86–1.79(m,2H),1.26(dd,J=19.1,13.8Hz,10H),0.86(t,J=6.8Hz,3H).

[0086] Preparation of 2,7-dibromo-9-dioctylfluorene 1d:

[0087]

[0088] Preparation method: 2,7-Dibromofluorene (9.23 g, 28 mmol), KOH (9.56 g, 168 mmol), KI (0.475 g, 2.85 mmol), and DMSO (70 mL) were added to a 250 mL three-necked flask. The mixture was reacted at 0 °C for 30 min, followed by the addition of 1-bromooctane (13.77 g, 57 mmol). After the addition was complete, the temperature was slowly increased to 25 °C and the reaction was carried out for 36 h. After the reaction was stopped, the reaction solution was poured into 300 mL of water, extracted with ethyl acetate, and the organic phases were combined. The solvent was removed by drying over anhydrous magnesium sulfate. The solution was purified by column chromatography using n-hexane as the eluent to obtain a white solid (1 d), with a yield of 65%. 1 H NMR (400MHz, CDCl3): δ (ppm) = 7.51 (d, J = 8.5Hz, 2H), 7.44 (d, J = 7.5Hz, 4H), 1.94–1.87 (m, 4H), 1.23–1.03 (m, 20H), 0.83 (t, J = 7.1Hz, 6H), 0.59 (s, 4H).

[0089] Example 4

[0090] Polymer preparation method: Taking P9 as an example, under N2 environment, terminal alkyne monomer P8 (1.2 g, 3 mmol), p-dibromobenzene (0.72 g, 3 mmol), CuI (57.14 mg, 0.3 mmol), PdCl2(PPh3)2 (35.1 mg, 0.05 mmol), and DMF (5 mL) were added sequentially to a 25 mL three-necked flask, and the reaction was carried out at 80 °C for 36 h. After the reaction was completed, the reaction solution was slowly poured into methanol solution, and a brown solid precipitated. The solid was filtered, dried, and extracted sequentially with methanol and acetone in a Soxhlet extractor for 12 h each. After vacuum drying, 0.46 g of brown solid was obtained. 1 H NMR (400MHz, CDCl3): δ (ppm) = 8.11 (s, 2H), 7.85–7.61 (m, 5H), 7.44 (s, 10H), 6.88 (s, 3H).

[0091] The synthesis methods for P10 to P12 are the same as those for P9.

[0092] As shown in the figure Figure 4 The hydrogen spectrum of polymer P9 shows that the proton shifts on the aromatic rings are all between 6 and 9 ppm, and the number of hydrogen atoms is consistent with the expected number of hydrogen atoms in the polymer. Figure 5 This is the Fourier transform infrared spectrum of polymer P9, at 2350 cm⁻¹. –1 The small peak at 3292 cm⁻¹ is the absorption peak of the stretching vibration of the carbon-carbon triple bond. –1The stretching vibration absorption peak of the ≡C-H bond that appeared at the point also disappeared, proving that the carbon-carbon triple bond did not break during the polymerization process, and the polymerization was successful.

[0093] Example 5

[0094] Performance characterization of conjugated polymers P9–P12 prepared in Example 4:

[0095] Ultraviolet absorption spectrum:

[0096] Figure 6 It is polymer P9~P12 in THF solution (1×10 –5 mol L -1 The ultraviolet-visible absorption spectrum in (e.g.) Figure 6 As shown, the UV-Vis absorption spectra of P9 and P11 both exhibit two main absorption peaks, at 298 nm and 372 nm, respectively. P10 and P12 exhibit three main absorption peaks, at 302 nm, 334 nm, and approximately 372 nm. The absorption band at 372 nm in polymers P9–P12 may be due to the π-π... * The maximum UV absorption peaks of P12 and P10 are red-shifted by about 35 nm compared to those of P9 and P11. This may be due to the introduction of tetraphenylvinyl and 9-dioctylfluorene, which increases the degree of conjugation of the entire polymer, resulting in a red shift of the UV absorption peaks of polymers P12 and P10.

[0097] Fluorescence emission spectrum:

[0098] Figure 7 This is the fluorescence emission spectrum of polymers P9–P12 in THF solution. There is a maximum emission peak in the 415–425 nm range, and the solution emits blue fluorescence. The fluorescence emission wavelengths of polymers incorporating structural units such as benzene rings, tetraphenylethylene, fluorene, and carbazole show little change. This series of polymers emits fluorescence to varying degrees in most solvents, but almost no fluorescence in the solid state, exhibiting a pronounced ACQ phenomenon, which may be due to the formation of intermolecular aggregates.

[0099] Polymers P9 to P12 exhibit fluorescence in most organic solvents, but due to the different structures of P9 to P12 polymers, the solvation effect has varying impacts on their luminescence performance. Figure 8These are the fluorescence emission spectra of polymers P9 to P12 in solvents of different polarities. The fluorescence emission wavelengths of P9 and P12 did not change significantly with increasing solution polarity, indicating that they were less affected by solution polarity. The fluorescence emission wavelengths of P9 were in the range of 429–440 nm, and those of P12 were in the range of 414–426 nm. The fluorescence emission wavelengths of polymers P9 to P12 in solutions of five different polarities did not show an obvious pattern, indicating that they were not affected by solvation effects.

[0100] It can be seen that polymers P10 and P11 exhibit a significant blue shift in DMSO solution, with maximum fluorescence emission wavelengths of 427 nm and 415 nm, respectively. This is likely due to the increased energy difference between the ground and excited states under the influence of a polar aprotic solvent, leading to a shift in the maximum fluorescence emission wavelength towards shorter wavelengths, thus resulting in the blue shift. The maximum fluorescence emission wavelength of this series of polymers is less affected by solution polarity.

[0101] Polymer electrochemical properties:

[0102] Table 1 Electrochemical performance of P9 to P12

[0103]

[0104] a The onset of oxidation potentials relative to Fc / Fc + couple.

[0105] b Determined from E onset ox.

[0106] c Estimated from E onset ox and E g .

[0107] e E g e =E LUMO –E HOMO

[0108] The electrochemical performance of polymer P9–P12 in dry DCM was studied using cyclic voltammetry (CV), and the CV curves are shown below. Figure 9 As shown, the corresponding electrochemical data are listed in Table 1. Table 1 shows that the first oxidation potential (E) of polymers P9-P12 is... onset The values ​​were 1.92 eV, 1.52 eV, 1.71 eV, and 1.04 eV, respectively. According to [E...HOMO =-(4.8+E) onset –E Fc / Fc+ )eV](E Fc / Fc+ =0.4eV, F c (representing ferrocene) and [E LUMO =(E HOMO +Eg)eV(E g Using the equations =1240 / λ, where λ is the starting wavelength of the UV-Vis absorption spectrum, calculate the molecular orbital energy levels (HOMO) and the lowest unoccupied molecular orbital (LUMO). The highest occupied molecular orbital energy levels of polymers P9 to P12 are -6.32 eV, -5.92 eV, -6.11 eV, and -5.44 eV, respectively. Their lowest unoccupied molecular orbital energy levels are -3.31 eV, -2.90 eV, -3.10 eV, and -2.45 eV, respectively.

[0109] Polymer thermodynamic properties:

[0110] Thermogravimetric analysis (TGA) was used to test the thermal stability of polymers P9 to P12 in this series. Figure 10 The thermal degradation process of polymers P9–P12 under N2 environment from 20°C to 800°C is shown. Figure 10 As can be seen, this series of polymers exhibits excellent thermal stability. Polymers P9 and P12 have a 5% thermogravimetric temperature (TWT) above 200℃, while polymers P10 and P11 have a 5% TWT around 400℃. All four polymers (P9 to P12) have a 10% TWT above 350℃, with polymer P10 reaching 492℃. Except for polymer P12, the other polymers retain more than 72% of their weight when heated to 800℃. This sufficiently demonstrates the excellent thermal stability of this series of fluorescent polymers, making them highly valuable for applications in optoelectronic devices.

[0111] Fluorescence properties of polymers P9–P12 for metal ions:

[0112] The selectivity of polymers P9–P12 for different metal ions was studied using fluorescence spectroscopy at room temperature. Figure 11 It can be seen from this that in 1 mL of tetrahydrofuran solution of polymers P9 to P12 (1×10⁻⁶), –5 Add 10 μL of the prepared solution with a concentration of 1×10⁻⁶ mol / L to each solution. –2 mol / L metal hydrochloride MCl m (M=Cu 2+ Zn 2+ Na + Ba 2+ K + Ca 2+Fe 3+ The fluorescence intensity was tested separately. It can be seen from the fluorescence emission spectra of polymers P9–P12 that the addition of Zn... 2+ Na + Ba 2+ K + and Ca 2+ The fluorescence intensity of the solutions decreased to varying degrees in samples containing the five ions. However, with the increase of Fe... 3+ and Cu 2+ The addition of two metal ions significantly altered the fluorescence emission spectrum, particularly those containing Fe. 3+ and Cu 2+ The maximum fluorescence intensity of the two metal ion solutions almost disappeared. Figure 12 These are blank samples of polymer P9 in tetrahydrofuran solution without any metal ions and sample solutions with different metal ions added (from left to right: blank sample, Cu). 2+ Zn 2+ Na + Ba 2+ K + Ca 2+ Fe 3+ In the photo taken under 365nm ultraviolet light, it can be clearly seen that with Cu... 2+ and Fe 3+ The fluorescence of the solution changed after the addition of Fe, indicating the presence of Fe. 3+ The fluorescence of the sample solution was quenched, and it reacted with the sample containing Fe. 3+ Compared to solutions containing Cu 2+ The sample solution still showed a faint blue fluorescence.

[0113] Metal ion sensitivity:

[0114] Overall, this series of polymers is effective against Fe. 3+ The response is more sensitive, so taking polymer P12 as an example, the effect of polymer P12 on Fe was studied through fluorescence titration experiments. 3+ The detection sensitivity was assessed in 1 mL of a THF solution containing polymer P12 (1 × 10⁻⁶). –5 Add 10 μL of 0.005–0.04 × 10⁻⁶ mol / L solution to each solution. –2 Fe in the concentration range of mol / L 3+ Solution. For example... Figure 13 As shown, with Fe 3+ As the concentration of the sample gradually increases, the fluorescence intensity of the sample solution gradually decreases.

[0115] At low concentrations of the analyte, its fluorescence response can be analyzed using the Stern-Volmer equation. The Stern-Volmer equation is as follows: I0 / I=1+K[Q], where I0 is the fluorescence intensity without iron ions, I is the fluorescence intensity with iron ions, K is the Stern-Volmer quenching constant, and [Q] is the concentration of iron ions.

[0116] The limit of detection (LOD) formula is as follows: LOD = 3σ / K, where LOD is the detection limit, σ is the standard deviation of the blank probe sample measurement, and K is the slope of the fitted curve. The LOD is calculated by fluorescence titration, and the detection limit is determined by fluorescence emission spectroscopy of a 1×10⁻⁶ tetrahydrofuran solution of P12. –5 Ten measurements were performed on the blank sample (mol / L), and the standard deviation σ of the blank sample measurement was obtained.

[0117] The fitted linear equation for P12 obtained through the Stern-Volmer equation is: I0 / I = 1.3092 + 29.067[Fe 3+ ](R 2 =0.9875), and its LOD is calculated to be 1.03 × 10 –5 mol / L, indicating that polymer P12 has a positive effect on Fe 3+ It has good detection sensitivity.

Claims

1. A conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit, characterized in that: It has the following repeating structural units: ； in, Ar is selected from the following structural units: 。 2. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit as described in claim 1, characterized in that: Includes the following steps: 1) 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene undergoes a diazotization-iodination tandem reaction with potassium iodide in the presence of NaNO2 and p-toluenesulfonic acid to yield 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene. 2) 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene undergoes a Sonogashira coupling reaction with trimethylsilylacetylene under the catalysis of PdCl2(PPh3)2 and CuI, followed by a detrimethylsilylation reaction under the action of K2CO3 to give 9-(4-ethynylphenoxy)-10-(4-ethynylphenyl)anthracene; 3) 9-(4-ethynylphenoxy)-10-(4-ethynylphenyl)anthracene is coupled with a dihaloaryl monomer to undergo Sonogashira coupling polymerization under the catalysis of PdCl2(PPh3)2 and CuI to obtain the product. The dihaloaryl monomers are selected from: ； X is bromine or iodine.

3. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 2, characterized in that: In step 1), 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is added to a solution containing methylbenzenesulfonic acid, cooled to below 0°C, and then a mixed solution containing NaNO2 and KI is added. The reaction is carried out at -5 to 5°C for 40 to 80 minutes.

4. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 3, characterized in that: The molar ratio of methylbenzenesulfonic acid to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.5~3.5):1; The molar ratio of NaNO2 to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.0~2.5):1; The molar ratio of KI to 9-(4-aminophenoxy)-10-(4-aminophenyl)anthracene is (2.0~2.5):

1.

5. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 2, characterized in that: In step 2), the molar ratio of 9-(4-iodophenoxy)-10-(4-iodophenyl)anthracene to trimethylsilylacetylene is 1:(2~3).

6. A method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 2 or 5, characterized in that: The conditions for the Sonogashira coupling reaction are: reaction at 65–75°C for 8–12 h.

7. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 2, characterized in that: The conditions for the detrimethylsilylation reaction are: at room temperature, for 4 to 6 hours.

8. The method for preparing a conjugated polymer containing a 9-phenoxy-10-phenylanthracene structural unit according to claim 2, characterized in that: The conditions for the Sonogashira coupling polymerization are: reaction at 75–85°C for 24–48 h.

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