A main chain charged fused heterocyclic polyelectrolyte and its preparation method and application

Abstract

The present invention discloses a main chain charged fused heterocyclic polyelectrolyte and its preparation method and application, and relates to the field of polymer technology. The main chain charged fused heterocyclic polyelectrolyte has the general structural formula: wherein x, y, z, and w are each independently an integer between 1 and 200; R1 is an aryl group, an aryl derivative, an unsubstituted alkyl group, or a substituted alkyl group; R2 is an aryl group, an aryl derivative, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, a sulfur atom, a selenium atom, a hydrogen atom, a halogen atom, or a biologically active fragment; is an aryl group or an aryl derivative; is selected from one of the following. The polyelectrolyte provided by the present invention is a polycyclic fused main chain charged fused heterocyclic polyelectrolyte, which has special aggregated luminescence properties, good solubility, film forming properties, excellent thermal stability, and morphological stability, and has unique potential application value in the fields of optical devices, protein detection, etc.

Description

Technical Field

[0001] The present invention relates to the field of polymer technology, in particular to a main chain charged fused heterocyclic polyelectrolyte and a preparation method and application thereof. Background Art

[0002] Polyelectrolytes are an important class of functional polymer materials whose repeating units contain ionizable groups. The electron-pushing and electron-pulling capabilities of charged aromatic groups can be leveraged to conveniently manipulate their fluorescence properties, conferring unique properties such as photosensitivity, reactive oxygen species generation, and acid-base responsiveness.

[0003] In existing polyelectrolytes, charges are mostly bound to the side chains of conjugated polymers. However, side-chain polyelectrolytes have difficulty directly affecting the electronic properties of the conjugated backbone, and thus have certain limitations in modulating photophysical properties.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] Based on the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a main chain charged fused heterocyclic polyelectrolyte and its preparation method and application, aiming to solve the problem that the charges of existing polyelectrolytes are mostly bound to the side chains of conjugated polymers.

[0006] The technical solutions of the present invention are as follows:

[0007] The first aspect of the present invention provides a main chain charged fused heterocyclic polyelectrolyte, wherein the main chain charged fused heterocyclic polyelectrolyte has the general structural formula:

[0008]

[0009] wherein x, y, z, and w are each independently an integer between 1 and 200 (specifically, 1, 2, 5, 10, 15, 20, 50, 70, 80, 100, 120, 130, 150, 180, or 200, etc.);

[0010] R1 is an aryl group, an aryl derivative, an unsubstituted alkyl group (such as a methyl group, an ethyl group, a propyl group, a butyl group, etc., but of course not limited thereto) or a substituted alkyl group (such as an alkoxy group, etc., but of course not limited thereto);

[0011] R2 is an aryl group, an aryl derivative, a nitro group, a cyano group, an unsubstituted alkyl group (such as a methyl group, an ethyl group, a propyl group, a butyl group, etc., but of course not limited thereto), a substituted alkyl group (such as a trifluoromethyl group; an alkoxy group, specifically a methoxy group, etc.; an alkyl group containing an ester group, such as an alkyl ester group, specifically CH3COO-, etc.; an alkyl group containing a ketocarbonyl group, such as an alkyl copper carbonyl group, specifically CH3CO-, etc., but of course not limited thereto), a sulfur atom, a selenium atom, a hydrogen atom, a halogen atom (such as F, Cl, Br, or I, etc.), or a biologically active fragment, wherein the biologically active fragment comprises one of a terpenoid, a steroid, a fatty alcohol, and a vitamin;

[0012] is an aryl group or an aryl derivative;

[0013] Selected from (Right now ), (Right now ), One of them.

[0014] The polyelectrolyte provided by the present invention is a polycyclic fused main-chain charged polyelectrolyte, namely a main-chain charged fused heterocyclic polyelectrolyte. It has unique aggregated luminescence properties, good solubility (soluble in dichloromethane, methanol, acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide), film-forming properties, excellent thermal stability and morphological stability, and has unique potential application value in optical devices, protein detection and other fields. The main-chain charged fused heterocyclic polyelectrolyte provided by the present invention effectively solves the problem that the charges of existing polyelectrolytes are mostly bound to the side chains of conjugated polymers, making it difficult to directly affect the electronic properties of the conjugated main chain, and having certain limitations in regulating photophysical properties.

[0015] The main chain charged fused heterocyclic polyelectrolyte provided by the present invention can not only continue the excellent properties of traditional side chain conjugated polyelectrolytes, but also utilize the strong push / pull electron ability of the fused heterocyclic charged groups in the main chain to directly and conveniently regulate the electronic properties such as absorption and emission of the fluorescent polyelectrolyte, providing great convenience for its physical and chemical property regulation.

[0016] Aggregation-induced emission is an effect in which molecules do not emit light or emit light weakly in solution, but emit light in an aggregated state. The current mainstream explanation for the principle of aggregation-induced emission is the mechanism of restricted intramolecular motion: in solution, the twisted structure of the excited state of the molecule changes greatly, which makes the reformation energy of the torsional vibration very large, providing an efficient energy dissipation channel for the non-radiative transition process. In the aggregated state, the "confined" environment formed by the intermolecular interaction greatly limits the change of the molecular twisted structure, making the reformation energy of the torsional vibration smaller, effectively blocking the non-radiative transition channel, and the radiative transition process dominates, and the molecule exhibits strong fluorescence. The main chain charged fused heterocyclic polyelectrolyte repeating unit provided by the present invention contains a large number of freely rotatable rotor side groups. In the solution state, the rotor rotates freely, which mainly manifests as non-radiative transition. In the aggregated state, due to the π-π stacking effect, the rotor rotation is restricted, which manifests as radiative transition, and the luminescence effect is enhanced. Therefore, the main chain charged fused heterocyclic polyelectrolyte provided by the present invention exhibits aggregated luminescence performance based on the mechanism of restricted intramolecular motion.

[0017] when for When the main chain charged fused heterocyclic polyelectrolyte has the general structural formula:

[0018]

[0019] Optionally, R1 is selected from one of the following structural formulas 1 to 25:

[0020]

[0021]

[0022] in, represents a connection point; m, p, q, and r are each independently an integer between 1 and 20 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20); R and R' are each independently a hydrogen atom, a halogen atom (for example, F, Cl, Br, or I), a sulfur atom, a selenium atom, a nitro group, a cyano group, an unsubstituted alkyl group (for example, a methyl group, an ethyl group, a propyl group, a butyl group, etc., but not limited thereto), a substituted alkyl groups (such as trifluoromethyl; alkoxy groups, specifically such as methoxy groups, etc.; alkyl groups containing ester groups, such as alkyl ester groups, specifically such as CH3COO-, etc.; alkyl groups containing ketocarbonyl groups, such as alkyl copper carbonyl groups, specifically such as CH3CO-, etc.; of course, but not limited to these), aryl groups, aryl derivatives (such as heteroaryl groups, specifically such as pyridine groups, thiophene groups, furan groups, indole groups, etc., of course, but not limited to these) or biologically active fragments, wherein the biologically active fragments include one of terpenes, steroids, fatty alcohols and vitamins;

[0023] X is one of an oxygen atom, a sulfur atom, and a selenium atom.

[0024] Optionally, R2 is selected from one of the following structural formulas 26 to 35:

[0025]

[0026] in, Indicates a connection;

[0027] s and t are each independently an integer between 0 and 20 (e.g., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, etc.);

[0028] R and R' are each independently a hydrogen atom, a halogen atom (such as F, Cl, Br or I, etc.), a sulfur atom, a selenium atom, a nitro group, a cyano group, an unsubstituted alkyl group (such as methyl, ethyl, propyl, butyl, etc., of course not limited to these), a substituted alkyl group (such as trifluoromethyl; alkoxy, specifically such as methoxy, etc.; an alkyl group containing an ester group, such as an alkyl ester group, specifically such as CH3COO-, etc.; an alkyl group containing a ketocarbonyl group, such as an alkyl copper carbonyl group, specifically such as CH3CO-, etc.; of course not limited to these), an aryl group, an aryl derivative (such as a heteroaryl group, etc., specifically such as a pyridine group, a thiophene group, a furan group, an indole group, etc.) or a biologically active fragment, wherein the biologically active fragment includes one of terpenes, steroids, fatty alcohols and vitamins.

[0029] Optionally, Selected from one of the following structural formulas:

[0030]

[0031] Indicates a connection.

[0032] The second aspect of the present invention provides a method for preparing the main chain charged fused heterocyclic polyelectrolyte as described above, which comprises the following steps:

[0033] Adding a bipyridine-substituted aromatic compound, an internal alkyne monomer, a rhodium catalyst and an additive into a solvent, and reacting to obtain the main chain charged fused heterocyclic polyelectrolyte;

[0034] The structural formula of the bipyridine-substituted aromatic compound is:

[0035] The structural formula of the internal alkyne monomer is:

[0036] R1 is an aryl group, an aryl derivative, an unsubstituted alkyl group (such as a methyl group, an ethyl group, a propyl group, a butyl group, etc., but of course not limited thereto) or a substituted alkyl group (such as a trifluoromethyl group; an alkoxy group, specifically a methoxy group, etc.; an alkyl group containing an ester group, such as an alkyl ester group, specifically CH3COO-, etc.; an alkyl group containing a ketocarbonyl group, such as an alkyl copper carbonyl group, specifically CH3CO-, etc.; but of course not limited thereto);

[0037] R2 is an aryl group, an aryl derivative, a nitro group, a cyano group, an unsubstituted alkyl group (such as a methyl group, an ethyl group, a propyl group, a butyl group, etc., but of course not limited thereto), a substituted alkyl group (such as a trifluoromethyl group; an alkoxy group, specifically a methoxy group, etc.; an alkyl group containing an ester group, such as an alkyl ester group, specifically CH3COO-, etc.; an alkyl group containing a ketocarbonyl group, such as an alkyl copper carbonyl group, specifically CH3CO-, etc., but of course not limited thereto), a sulfur atom, a selenium atom, a hydrogen atom, a halogen atom (such as F, Cl, Br, or I, etc.), or a biologically active fragment, wherein the biologically active fragment comprises one of a terpenoid, a steroid, a fatty alcohol, and a vitamin;

[0038] is an aryl group or an aryl derivative;

[0039] The additive includes one of silver trifluoroacetate, silver trifluoromethanesulfonate, silver p-toluenesulfonate and anhydrous copper acetate.

[0040] Currently, the variety of main-chain charged fluorescent polyelectrolyte structures is scarce, and there are still few reports on synthetic methods that can efficiently prepare main-chain charged conjugated polyelectrolytes in one step using cheap and readily available monomer raw materials. The difficulty in synthesizing conjugated polyelectrolytes greatly limits the diversity of the structures and functions of fluorescent polyelectrolytes. Therefore, it is of great significance to develop a convenient, economical, and efficient new polymerization reaction to achieve the efficient construction of main-chain charged fluorescent polyelectrolytes with novel structures. Based on this, the present invention provides the above-mentioned preparation method, which is simple and efficient. The target product can be obtained in a single step, namely, a rhodium-catalyzed C-H activation cyclization reaction, with a high yield (yield of up to 98.0%). The raw materials used are cheap and readily available. The prepared main-chain charged fused heterocyclic polyelectrolyte has a high molecular weight (weight-average molecular weight of up to 231,000 and a polymer dispersity index of 1.29-1.69), has unique aggregated luminescence properties, and has unique potential application value in fields such as optical devices and protein detection.

[0041] Optionally, the rhodium catalyst includes dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer; and the solvent includes at least one of acetonitrile, methanol, 1,2-dichloroethane, N,N-dimethylformamide and dimethyl sulfoxide, but is not limited thereto.

[0042] Optionally, the molar ratio of the internal alkyne monomer, the bipyridine-substituted aromatic compound, the rhodium catalyst and the additive is 1:(0.5-1.25):(0.1-0.5):(2.3-9.5); for example, the molar ratio of the internal alkyne monomer, the bipyridine-substituted aromatic compound, the rhodium catalyst and the additive is 1:0.5:0.1:2.3, 1:1.25:0.5:9.2, 1:1:0.25:6, 1:0.5:0.1:9 or 1:0.75:0.3:7, etc.

[0043] The reaction concentration of the internal alkyne monomer is 0.05 to 2 mol / L (for example, 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.5 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L or 2 mol / L, etc.);

[0044] The reaction conditions are:

[0045] Inert gas atmosphere, the reaction temperature is 100-140°C (for example, 100°C, 110°C, 120°C, 130°C or 140°C), and the reaction time is 12-24h (for example, 12h, 15h, 18h, 20h, 22h or 24h, etc.).

[0046] Optionally, after the reaction, before obtaining the main chain charged fused heterocyclic polyelectrolyte, the following steps are further included:

[0047] The reaction solution obtained after the reaction was cooled to room temperature, and filtered to obtain a filtrate;

[0048] The filtrate is added to a precipitant for precipitation, and then filtered and dried.

[0049] The polymer product obtained in the present invention is easy to separate and only needs to be precipitated once in a precipitant to obtain a main chain charged fused heterocyclic polyelectrolyte with high purity.

[0050] In the present invention, specifically, the reaction solution obtained after the reaction is cooled to room temperature, then diluted with methanol and dichloromethane (the volume ratio of the two can be 1:3), and then simply filtered through neutral alumina to obtain a filtrate; the obtained filtrate is added to a precipitant for precipitation, filtered, and the precipitate is collected and dried to constant weight to obtain the main chain charged fused heterocyclic polyelectrolyte.

[0051] Optionally, the precipitant includes at least one of methanol, ether, acetone and n-hexane, but is not limited thereto;

[0052] The R1 is selected from one of the following structural formulas 1 to 25, and the R2 is selected from one of the following structural formulas 26 to 35. Selected from one of the following structural formulas 36 to 46:

[0053]

[0054]

[0055]

[0056] in, represents a connection; m, p, q, and r are each independently an integer between 1 and 20 (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20); s and t are each independently an integer between 0 and 20 (for example, 0,

[0057] 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, etc.); R, R' are each independently a hydrogen atom, a halogen atom (such as F, Cl, Br or I, etc.), a nitro group, a cyano group, an unsubstituted alkyl group (such as methyl, ethyl, propyl, etc., of course not limited thereto), a substituted alkyl group (such as trifluoromethyl; an alkoxy group, specifically such as methoxy, etc.; an alkyl group containing an ester group, such as an alkyl ester group, specifically such as CH3COO-, etc.; an alkyl group containing a ketocarbonyl group, such as an alkyl copper carbonyl group, specifically such as CH3CO-, etc.; of course not limited thereto)), a sulfur atom, a selenium atom, an aryl group, an aryl derivative (such as a heteroaryl group, etc.) or a biologically active fragment, wherein the biologically active fragment includes one of terpenes, steroids, fatty alcohols and vitamins.

[0058] The third aspect of the present invention provides an application of the main chain charged fused heterocyclic polyelectrolyte as described above and / or the main chain charged fused heterocyclic polyelectrolyte prepared by the preparation method as described above in the field of optical devices or protein detection.

[0059] Beneficial Effects: The polyelectrolyte provided by the present invention is a polycyclic fused main-chain charged polyelectrolyte with unique aggregated luminescence properties, good solubility (e.g., soluble in dichloromethane, methanol, acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide), film-forming properties, and excellent thermal and morphological stability. It has unique potential applications in optical devices, protein detection, and other fields. Furthermore, the preparation method provided by the present invention is simple and efficient, requiring only a single step, namely, a rhodium-catalyzed C-H activation cyclization reaction, to obtain the target product with a high yield (up to 98.0%), and the raw materials used are inexpensive and readily available. The present invention effectively addresses the problem of existing polyelectrolytes, where the charge is mostly bound to the side chains of the conjugated polymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the polyelectrolyte P1 prepared in Example 1 in deuterated dimethyl sulfoxide.

[0061] Figure 2 (A) is a photoluminescence curve of the polyelectrolyte P1 prepared in Example 1 in a dimethyl sulfoxide solution with the same water content, and (B) is a trend diagram of the fluorescence emission intensity change of the polyelectrolyte P1 prepared in Example 1 in a dimethyl sulfoxide solution with the same water content.

[0062] Figure 3 This is the hydrogen nuclear magnetic resonance spectrum of the polyelectrolyte P2 prepared in Example 2 in deuterated dimethyl sulfoxide.

[0063] Figure 4 (A) is a photoluminescence curve of the polyelectrolyte P2 prepared in Example 2 in a dimethyl sulfoxide solution with the same water content, and (B) is a fluorescence emission intensity change trend diagram of the polyelectrolyte P2 prepared in Example 2 in a dimethyl sulfoxide solution with the same water content.

[0064] Figure 5 (A) is a fluorescence intensity change curve of the polyelectrolyte P2 prepared in Example 2 in PBS solutions with different contents of bovine serum albumin added thereto, and (B) is a fluorescence emission intensity change trend diagram of the polyelectrolyte P2 prepared in Example 2 in PBS solutions with different contents of bovine serum albumin added thereto.

[0065] Figure 6 This is the hydrogen nuclear magnetic resonance spectrum of the polyelectrolyte P3 prepared in Example 3 in deuterated dimethyl sulfoxide.

[0066] Figure 7 This is the hydrogen nuclear magnetic resonance spectrum of the polyelectrolyte P4 prepared in Example 4 in deuterated dimethyl sulfoxide.

[0067] Figure 8This is the hydrogen nuclear magnetic resonance spectrum of the polyelectrolyte P5 prepared in Example 5 in deuterated dimethyl sulfoxide.

[0068] Figure 9 (A) is a graph showing the photoluminescence intensity of the polyelectrolyte P5 prepared in Example 5 in dimethyl sulfoxide solutions with different water contents. (B) is a graph showing the fluorescence intensity variation of the polyelectrolyte P5 prepared in Example 5 in dimethyl sulfoxide solutions with the same water content. DETAILED DESCRIPTION

[0069] The present invention provides a polyelectrolyte and its preparation method and application. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only for the purpose of explaining the present invention and are not intended to limit the present invention.

[0070] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0071] The present invention will be further described below with reference to specific examples.

[0072] Unless otherwise specified, the raw materials used in the following examples are all commercially available products.

[0073] In the following examples, 1,5-di(2-pyridyl)naphthalene was prepared according to the method disclosed in the literature (Xu K, Fu Y, Zhou Y, et al. Angewandte Chemie, 2017, 129(50), 16092-16097.), and 4,4'-(1,4-hexenedioxy)bis(phenylacetylene) was prepared according to the method disclosed in the literature (Gao, M.; Lam, JWY; Liu, Y.; Li, J.; Tang, BZ Polymer Chemistry 2013, 4(9), 2841-2849.).

[0074] 1,6-bis(4-(hex-1-yn-1-yl)phenoxy)hexane was prepared according to the method disclosed in the literature (Gao, M.; Lam, JWY; Liu, Y.; Li, J.; Tang, BZ Polymer Chemistry 2013, 4(9), 2841-2849).

[0075] 1,6-Di(2-pyridyl)pyrene was prepared according to the method disclosed in the literature (Xu K, Fu Y, Zhou Y, et al. Angewandte Chemie, 2017, 129(50), 16092-16097.).

[0076] 1,1′-[1,2-bis[4-(2-phenylethynyl)phenyl]-1,2-vinyl]bisbenzene was prepared according to the method disclosed in the literature (Gao, M.; Lam, JWY; Liu, Y.; Li, J.; Tang, BZ Polymer Chemistry 2013, 4(9), 2841-2849).

[0077] Example 1

[0078] This embodiment provides a main chain charged fused heterocyclic polyelectrolyte (denoted as polyelectrolyte P1) and a preparation method thereof. The structural formula of polyelectrolyte P1 is as follows:

[0079]

[0080] The synthetic route of polyelectrolyte P1 is as follows:

[0081]

[0082] The preparation method of polyelectrolyte P1 comprises the following steps:

[0083] (1) Under inert gas protection, 47.02 mg of 4,4'-(1,4-hexenedioxy)bis(diphenylacetylene), 28.22 mg of 1,5-di(2-pyridyl)naphthalene, 18.5 mg of dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer ([Cp*RhCl2]2) and 203.21 mg of silver trifluoroacetate (AgCF3CO2) were added to 1 mL of dry acetonitrile solution and dissolved at 120°C. The reaction was stirred at 4°C for 12 hours. After the reaction was complete, the reaction mother liquor was diluted with 4 mL of dichloromethane and 1 mL of methanol, filtered through a 4 cm high neutral alumina column (200 mesh), and then directly precipitated in 100 mL of ether solution. The precipitate was collected and dried under vacuum at 65°C to constant weight to obtain polyelectrolyte P1 with a yield of 98.0%, an absolute weight-average molecular weight of 231,700 g / mol, and a polymer dispersity index (PDI) of 1.60.

[0084] The H NMR spectrum of the polyelectrolyte P1 prepared in deuterated dimethyl sulfoxide is shown in FIG. Figure 1 As shown. Figure 1As can be seen in the figure, the solvent peak and water peak of deuterated dimethyl sulfoxide are located at 2.50 ppm and 3.30 ppm, respectively. All other hydrogen atom signals are from polyelectrolyte P1, and several characteristic hydrogen atom signals can be assigned accordingly. The peak at 4.0 ppm is a characteristic peak for hydrogen atoms attached to the methylene group connected to the oxygen in the alkyl chain.

[0085] The photoluminescence curves of the polyelectrolyte P1 prepared in Example 1 in dimethyl sulfoxide solutions with different water contents (i.e., mixed solutions of dimethyl sulfoxide and water with different water contents, the same below, wherein the volume content of water is 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%) are shown in FIG. Figure 2 As shown in (A), the fluorescence emission intensity variation trend in dimethyl sulfoxide solutions with different water contents is as follows Figure 2 As shown in (B), I is the fluorescence intensity of polyelectrolyte P1 in dimethyl sulfoxide solutions with different water contents, and I0 is the fluorescence intensity of polyelectrolyte P1 in pure dimethyl sulfoxide solution. Figure 2 As can be seen in (B), with the increase of water content, the fluorescence of polyelectrolyte P1 gradually increases and reaches a maximum at 90% water content. Polyelectrolyte P1 exhibits obvious aggregation-induced emission phenomenon.

[0086] Example 2

[0087] This embodiment provides a main chain charged fused heterocyclic polyelectrolyte (denoted as polyelectrolyte P2) and a preparation method thereof. The structural formula of polyelectrolyte P2 is as follows:

[0088]

[0089] The synthetic route of polyelectrolyte P2 is as follows:

[0090]

[0091] The preparation method of polyelectrolyte P2 comprises the following steps:

[0092] Under inert gas protection, 43.1 mg of 1,6-bis(4-(hex-1-yn-1-yl)phenoxy)hexane, 28.22 mg of 1,5-di(2-pyridyl)naphthalene, 18.5 mg of dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer, and 203.21 mg of silver trifluoroacetate were added to 1 mL of dry acetonitrile solution and dissolved. The mixture was stirred at 120°C for 12 h. After the reaction was complete, the reaction mother liquor was diluted with 4 mL of dichloromethane and 1 mL of methanol, filtered through a 4 cm high neutral alumina column (200 mesh), and then directly precipitated in 100 mL of ether solution. The precipitate was collected and dried in vacuo at 65°C to constant weight to obtain polyelectrolyte P2 with a yield of 91.0%.

[0093] The H NMR spectrum of the polyelectrolyte P2 prepared in deuterated dimethyl sulfoxide is shown in FIG. Figure 3 As shown. Figure 3 As can be seen in the figure, the solvent peak and water peak of deuterated dimethyl sulfoxide are located at 2.50 ppm and 3.30 ppm, respectively. All other hydrogen atom signals are from polyelectrolyte P2, and several characteristic hydrogen atom signals can be assigned accordingly. The peak at 4.0 ppm is a characteristic peak of hydrogen atoms from the methylene group attached to the oxygen in the alkyl chain.

[0094] The photoluminescence curves of the polyelectrolyte P2 prepared in Example 2 in dimethyl sulfoxide solutions with different water contents are shown in FIG. Figure 4 As shown in (A), the fluorescence emission intensity variation trend of polyelectrolyte P2 in dimethyl sulfoxide solutions with different water contents is shown in Figure 4 As shown in (B), I is the fluorescence intensity of polyelectrolyte P2 in dimethyl sulfoxide solutions with different water contents, and I0 is the fluorescence intensity of polyelectrolyte P2 in pure dimethyl sulfoxide solution. Figure 4 As can be seen in (B), with the increase of water content, the fluorescence of polyelectrolyte P2 gradually increases and reaches the maximum at 90% water content. Polyelectrolyte P2 shows obvious aggregation-induced emission phenomenon.

[0095] The protein detection application results of the polyelectrolyte P2 prepared in Example 2 are as follows Figure 5 As shown, I is the fluorescence intensity of polyelectrolyte P2 in PBS buffer with different bovine serum albumin contents, and I0 is the fluorescence intensity of polyelectrolyte P2 in pure PBS buffer. Figure 5 In the experiment, polyelectrolyte P2 interacted with different amounts of bovine serum albumin (BSA) (0, 5, 15, 25, 45, 65, 100, 150, 200, 250, 300, and 400 μL) in PBS buffer (3 mL), causing changes in the fluorescence intensity of polyelectrolyte P2. As the BSA content increased, the fluorescence intensity of polyelectrolyte P2 in solution first decreased and then increased. This indicates that the polyelectrolyte provided by the present invention can be used in the field of protein detection technology.

[0096] Example 3

[0097] This embodiment provides a main chain charged fused heterocyclic polyelectrolyte (denoted as polyelectrolyte P3) and a preparation method thereof. The structural formula of polyelectrolyte P3 is as follows:

[0098]

[0099] The synthetic route of polyelectrolyte P3 is as follows:

[0100]

[0101] The preparation method of polyelectrolyte P3 comprises the following steps:

[0102] Under inert gas protection, 47.02 mg of 4,4'-(1,4-hexenedioxy)bis(diphenylacetylene), 33.2 mg of 1,5-di(2-pyridyl)anthracene, 18.5 mg of dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer, and 203.21 mg of silver trifluoroacetate were dissolved in 1 mL of dry acetonitrile solution and stirred at 120°C for 12 hours. After the reaction was complete, the reaction mother liquor was diluted with 4 mL of dichloromethane and 1 mL of methanol, filtered through a 4 cm high neutral alumina column (200 mesh), and then directly precipitated in 100 mL of ether solution. The precipitate was collected and dried in vacuo at 65°C to constant weight to obtain polyelectrolyte P3 with a yield of 86.2%.

[0103] The H NMR spectrum of the polyelectrolyte P3 prepared in deuterated dimethyl sulfoxide is shown in FIG. Figure 6 As shown. Figure 6 As can be seen in the figure, the solvent peaks for deuterated dimethyl sulfoxide and water are located at 2.50 ppm and 3.30 ppm, respectively, while the solvent peak for residual dichloromethane is at 5.76 ppm. All other signals are hydrogen atom signals from polyelectrolyte P3, and several characteristic hydrogen atom signals can be assigned accordingly. The peak at 4.0 ppm is a characteristic hydrogen atom peak from the methylene group attached to the oxygen in the alkyl chain.

[0104] Example 4

[0105] This embodiment provides a main chain charged fused heterocyclic polyelectrolyte (denoted as polyelectrolyte P4) and a preparation method thereof. The structural formula of polyelectrolyte P4 is as follows:

[0106]

[0107] The synthetic route of polyelectrolyte P4 is as follows:

[0108]

[0109] The preparation method of polyelectrolyte P4 comprises the following steps:

[0110] Under inert gas protection, 47.02 mg of 4,4'-(1,4-hexenedioxy)bis(diphenylacetylene), 35.6 mg of 1,6-di(2-pyridyl)pyrene, 18.5 mg of dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer, and 203.21 mg of silver trifluoroacetate were added to 1 mL of dry acetonitrile solution and dissolved. The mixture was stirred at 12°C for 12 h. After the reaction was complete, the reaction mother liquor was diluted with 4 mL of dichloromethane and 1 mL of methanol, filtered through a 4 cm high neutral alumina column (200 mesh), and then directly precipitated in 100 mL of ether solution. The precipitate was collected and dried in vacuo at 65°C to constant weight to obtain polyelectrolyte P4 with a yield of 91.1%.

[0111] The H NMR spectrum of the polyelectrolyte P4 prepared in deuterated dimethyl sulfoxide is shown in FIG. Figure 7 As shown. Figure 7 As can be seen in the figure, the solvent peaks for deuterated dimethyl sulfoxide and water are located at 2.50 ppm and 3.30 ppm, respectively, while the solvent peak for residual dichloromethane is at 5.76 ppm. All other signals are hydrogen atom signals from polyelectrolyte P4, and several characteristic hydrogen atom signals can be assigned accordingly. The peak at 4.0 ppm is a characteristic peak for hydrogen atoms on the methylene group connected to the oxygen on the alkyl chain.

[0112] Example 5

[0113] This embodiment provides a main chain charged fused heterocyclic polyelectrolyte (denoted as polyelectrolyte P5) and a preparation method thereof. The structural formula of polyelectrolyte P5 is as follows:

[0114]

[0115] The synthetic route of polyelectrolyte P5 is as follows:

[0116]

[0117] The preparation method of polyelectrolyte P5 comprises the following steps:

[0118] Under inert gas protection, 53.2 mg of 1,1'-[1,2-bis[4-(2-phenylethynyl)phenyl]-1,2-vinyl]bisbenzene, 28.22 mg of 1,5-di(2-pyridyl)naphthalene, 18.5 mg of dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer, and 203.21 mg of silver trifluoroacetate were dissolved in 1 mL of dry acetonitrile solution and stirred at 120°C for 12 h. After the reaction was complete, the reaction mother liquor was diluted with 4 mL of dichloromethane and 1 mL of methanol, filtered through a 4 cm high neutral alumina column (200 mesh), and then directly precipitated in 100 mL of diethyl ether solution. The precipitate was collected and dried in vacuo at 65°C to constant weight to obtain polyelectrolyte P5 with a yield of 84.8%.

[0119] The H NMR spectrum of the polyelectrolyte P5 prepared in deuterated dimethyl sulfoxide is shown in FIG. Figure 8 As shown. Figure 8 As can be seen in the figure, the solvent peak of deuterated dimethyl sulfoxide and the water peak are located at 2.50 ppm and 3.30 ppm, respectively, and the solvent peak of residual dichloromethane is at 5.76 ppm. In addition, all other hydrogen atom signals are hydrogen atom signals of polyelectrolyte P5, and several characteristic hydrogen atom signals can also be assigned accordingly.

[0120] The photoluminescence curves of the polyelectrolyte P5 prepared in this example in dimethyl sulfoxide solutions with different water contents are shown in FIG. Figure 9 As shown in (A), the fluorescence emission intensity variation trend of polyelectrolyte P5 in dimethyl sulfoxide solutions with different water contents is shown in Figure 9 As shown in (B), I represents the photoluminescence intensity of polyelectrolyte P5 in dimethyl sulfoxide solutions with different water contents, and I0 represents the photoluminescence intensity of polyelectrolyte P5 in pure dimethyl sulfoxide. Figure 9 As can be seen in (B), with the increase of water content, the fluorescence of polyelectrolyte P5 gradually increases and reaches a maximum at 90% water content, proving that the polyelectrolyte P5 exhibits obvious aggregation-induced emission phenomenon.

[0121] In summary, the present invention provides a main-chain charged fused heterocyclic polyelectrolyte, its preparation method, and application. The polyelectrolyte provided by the present invention is a polycyclic fused main-chain charged fused heterocyclic polyelectrolyte with unique aggregated luminescence properties, good solubility (e.g., solubility in dichloromethane, methanol, acetonitrile, N,N-dimethylformamide, and dimethyl sulfoxide), film-forming properties, excellent thermal stability, and morphological stability, and has unique potential applications in optical devices, protein detection, and other fields. In addition, the preparation method provided by the present invention is simple and efficient, requiring only a single step, namely, a rhodium-catalyzed CH activation cyclization reaction, to obtain the target product. The raw materials used are inexpensive and readily available, with a high yield (up to 98.0%), and the product is easily separated with high atom economy. The present invention effectively solves the problem that the charges of existing polyelectrolytes are mostly bound to the side chains of the conjugated polymer, making it difficult to directly affect the electronic properties of the conjugated main chain, and thus having certain limitations in regulating photophysical properties.

[0122] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A main chain charged fused heterocyclic polyelectrolyte, characterized in that: The general structural formula of the main chain charged fused heterocyclic polyelectrolyte is: wherein x, y, z, and w are each independently an integer between 1 and 200; R1 is aryl, aryl derivative, unsubstituted alkyl or substituted alkyl; R2 is an aryl group, an aryl derivative, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, a sulfur atom, a selenium atom, a hydrogen atom, a halogen atom, or a biologically active fragment, wherein the biologically active fragment comprises one of a terpenoid, a steroid, a fatty alcohol, and a vitamin; is an aryl group or an aryl derivative; Selected from One of them.

2. The main chain charged fused heterocyclic polyelectrolyte according to claim 1, characterized in that R1 is selected from one of the following structural formulas 1 to 25: wherein -* represents a junction; m, p, q, and r are each independently an integer between 1 and 20; R and R' are each independently a hydrogen atom, a halogen atom, a sulfur atom, a selenium atom, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, an aryl group, an aryl derivative, or a biologically active fragment, wherein the biologically active fragment comprises one of a terpenoid, a steroid, a fatty alcohol, and a vitamin; X is one of an oxygen atom, a sulfur atom, and a selenium atom.

3. The main chain charged fused heterocyclic polyelectrolyte according to claim 1, characterized in that R2 is selected from one of the following structural formulas 26 to 35: Among them, -* indicates a connection; s, t are each independently an integer between 0 and 20; R and R' are each independently a hydrogen atom, a halogen atom, a sulfur atom, a selenium atom, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, an aryl group, an aryl derivative or a biologically active fragment, wherein the biologically active fragment includes one of terpenes, steroids, fatty alcohols and vitamins.

4. The main chain charged fused heterocyclic polyelectrolyte according to claim 1, characterized in that Selected from one of the following structural formulas: -* indicates a connection.

5. A method for preparing the main chain charged fused heterocyclic polyelectrolyte according to claim 1, characterized in that: The steps include: Adding a bipyridine-substituted aromatic compound, an internal alkyne monomer, a rhodium catalyst and an additive into a solvent, and reacting to obtain the main chain charged fused heterocyclic polyelectrolyte; The structural formula of the bipyridine-substituted aromatic compound is: The structural formula of the internal alkyne monomer is: R1 is aryl, aryl derivative, unsubstituted alkyl or substituted alkyl; R2 is an aryl group, an aryl derivative, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, a sulfur atom, a selenium atom, a hydrogen atom, a halogen atom, or a biologically active fragment, wherein the biologically active fragment comprises one of a terpenoid, a steroid, a fatty alcohol, and a vitamin; is an aryl group or an aryl derivative; The additive includes one of silver trifluoroacetate, silver trifluoromethanesulfonate, silver p-toluenesulfonate and anhydrous copper acetate.

6. The preparation method according to claim 5, characterized in that The rhodium catalyst includes dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer; and the solvent includes at least one of acetonitrile, methanol, 1,2-dichloroethane, N,N-dimethylformamide and dimethyl sulfoxide.

7. The preparation method according to claim 5, characterized in that The molar ratio of the internal alkyne monomer, the bipyridine-substituted aromatic compound, the rhodium catalyst and the additive is 1:(0.5-1.25):(0.1-0.5):(2.3-9.5); the reaction concentration of the internal alkyne monomer is 0.05-2 mol / L; The reaction conditions are: Inert gas atmosphere, the reaction temperature is 100-140°C and the reaction time is 12-24h.

8. The preparation method according to claim 5, characterized in that After the reaction, the following steps are further included before obtaining the main chain charged fused heterocyclic polyelectrolyte: The reaction solution obtained after the reaction was cooled to room temperature, and filtered to obtain a filtrate; The filtrate is added to a precipitant for precipitation, and then filtered and dried.

9. The preparation method according to claim 8, characterized in that The precipitant comprises at least one of methanol, ether, acetone and n-hexane; R1 is selected from one of the following structural formulas 1 to 25, and R2 is selected from one of the following structural formulas 26 to 35, Selected from one of the following structural formulas 36 to 46: wherein -* represents a linker; m, p, q, and r are each independently an integer between 1 and 20; s and t are each independently an integer between 0 and 20; and R and R' are each independently a hydrogen atom, a halogen atom, a sulfur atom, a selenium atom, a nitro group, a cyano group, an unsubstituted alkyl group, a substituted alkyl group, an aryl group, an aryl derivative, or a biologically active fragment, wherein the biologically active fragment includes one of a terpenoid, a steroid, a fatty alcohol, and a vitamin.

10. Use of the main-chain charged fused heterocyclic polyelectrolyte according to any one of claims 1 to 4 and / or the main-chain charged fused heterocyclic polyelectrolyte prepared by the preparation method according to any one of claims 5 to 9 in the field of optical devices or protein detection.

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