Bis-selenium compounds, selenium-containing thin films, and methods of making the same

Abstract

The present application relates to the technical field of chemical synthesis, in particular to a double selenium compound, a selenium-containing film and a preparation method thereof.The double selenium compound has a structure of formula (I).The preparation method comprises the following steps: mixing a compound of formula (II) and an inorganic diselenide to obtain the compound of formula (I).The present application takes the double selenium compound as a core raw material, and combines a substrate and optional reagents such as a reducing agent, a base, a melanin precursor and an oxidizing agent to prepare a selenium-containing film under mild conditions.The present application solves the synthesis problem of integrating catechol and diselenide bond and the application bottleneck of uneven distribution of selenium components and weak binding force in the selenium-containing film, and the product has good adhesion and stability, and has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis technology, specifically relating to diselenium compounds, selenium-containing thin films, and their preparation methods. Background Technology

[0002] In synthetic chemistry, both catechol and organoselenium compounds are important building blocks for constructing functional molecules: the catechol group possesses excellent metal chelating ability and surface adhesion properties, while compounds containing diselenyl bonds (-Se-Se-) have attracted much attention in materials science due to their unique chemical properties. However, integrating these two highly reactive functional groups into the same stable molecular framework presents significant challenges: in traditional synthetic routes, classic methods for constructing diselenyl bonds (such as selenool oxidative coupling) often require oxidative or alkaline conditions, which can easily lead to the oxidation of the catechol unit to a quinone structure or unintended selenization, compromising the integrity of the target product; even with a strategy of pre-protecting the phenolic hydroxyl group, commonly used protecting groups (such as methyl and benzyl) lack sufficient stability in subsequent diselenyl bond construction or deprotection steps, resulting in lengthy and inefficient synthetic routes. Therefore, developing synthetic methods with mild conditions, good functional group tolerance, simple steps, and strong universality to efficiently construct novel compounds containing both catechol and diselenyl structures has significant synthetic chemical value and application needs.

[0003] In terms of materials applications, biomimetic coatings based on catechol chemistry (such as polydopamine) are widely used due to their simple film formation and universal adhesion, but their long-term stability is poor, especially their durability under harsh environments such as oxidation and humid heat. Introducing selenium into the coating system is an effective strategy to improve its antioxidant properties and stability, but existing technologies mostly introduce selenium by physically blending selenium nanoparticles or by post-modifying existing coatings. This easily leads to problems such as uneven distribution of selenium components, weak bonding with the substrate, and easy leaching and deactivation, making it impossible to achieve uniform and stable fixation of selenium in the coating. Patent CN116768772A utilizes the coordination of selenium-containing compounds with a gold substrate to generate selenium-containing thin films, which have good stability and applicability. However, this method relies on the coordination between selenium and gold and cannot be applied to other non-metallic substrates. Summary of the Invention

[0004] To overcome the aforementioned technical bottlenecks, this invention provides a novel diselenium compound, its preparation method, and a selenium-containing thin film through innovative molecular design and a "molecular design-controllable film formation" strategy. This simultaneously solves the synthesis problems and application defects, laying the foundation for a new generation of highly stable and multifunctional coating materials.

[0005] In a first aspect, the present invention provides a compound of formula (Ⅰ), a diselenium compound: (I) Among them, R1 and R2 may be the same or different, and each is independently selected from one of the following: -COOH, -H, -OH, -CH3, -CH(CH3)2, -C(CH3)3, -OCH3, -NH2, -CONH2, -CN, -NO2, -CHO, -SO3H, -F, -Cl, -Br, -I, -CF3, -CCl3, -N(CH3)2, -NHCOCH3, -OCOCH3, -C6H5, -COCH3, -COOCH3, -CH=CH2, -CH2NO; R3 and R4 may be the same or different, and each is independently selected from one of the following: -COOH, -H, -OH, -CH3, -CH(CH3)2, -C(CH3)3, -OCH3, -NH2, -CONH2, -CN, -NO2, -CHO, -SO3H, -F, -Cl, -Br, -I, -CF3, -CCl3, -N(CH3)2, -NHCOCH3, -OCOCH3, -C6H5, -COCH3, -COOCH3, -CH=CH2, -CH2NO; n and m are natural numbers greater than 1, preferably natural numbers between 1 and 30.

[0006] The phenolic hydroxyl group in the benzene ring structure can be located at any position on the benzene ring, and the number of phenolic hydroxyl groups can be 1-5 or 2.

[0007] Secondly, the present invention provides a method for preparing the compound of formula (I) above, the reaction route of which is as follows: (II) (I) Compound of formula (I) is obtained by reacting a mixture of compound (II), inorganic diselenide and solvent; Wherein, X is selected from one of -OTs, -OMs, -OTf, -ONO2, -OAc, -N2⁺, -SR2⁺, -I, -Br, -Cl; R1 and R2 may be the same or different, and each is independently selected from one of the following: -COOH, -H, -OH, -CH3, -CH(CH3)2, -C(CH3)3, -OCH3, -NH2, -CONH2, -CN, -NO2, -CHO, -SO3H, -F, -Cl, -Br, -I, -CF3, -CCl3, -N(CH3)2, -NHCOCH3, -OCOCH3, -C6H5, -COCH3, -COOCH3, -CH=CH2, -CH2NO; R3 and R4 may be the same or different, and each is independently selected from one of the following: -COOH, -H, -OH, -CH3, -CH(CH3)2, -C(CH3)3, -OCH3, -NH2, -CONH2, -CN, -NO2, -CHO, -SO3H, -F, -Cl, -Br, -I, -CF3, -CCl3, -N(CH3)2, -NHCOCH3, -OCOCH3, -C6H5, -COCH3, -COOCH3, -CH=CH2, -CH2NO; n and m are natural numbers greater than 1, preferably natural numbers between 1 and 30.

[0008] The phenolic hydroxyl group in the benzene ring structure can be located at any position on the benzene ring, and the number of phenolic hydroxyl groups can be 1-5.

[0009] Inorganic diselenides include alkali metal diselenides, alkaline earth metal diselenides, and other diselenides synthesized through direct elemental synthesis, reduction, oxidation, and other methods; preferably, disodium diselenide and disodium diselenide. Specifically, they can be obtained by reacting selenium with borohydrides. The present invention does not impose particular limitations on the preparation method; it can be obtained by reacting selenium with borohydrides in the presence of water or an alcohol solvent. The alcohol reagent can be methanol, ethanol, propanol, butanol, propylene glycol, ethylene glycol, etc.

[0010] Preferably, the reaction temperature is 30-100 ℃.

[0011] Preferably, the molar ratio of diselenide and compound (II) is (1-5):1.

[0012] Preferably, the molar ratio of reducing agent to selenium powder is (1-5):1.

[0013] Preferably, the solvent is an organic solvent.

[0014] Preferably, the organic solvent includes at least one of N,N-dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, dichloromethane, 2-methyltetrahydrofuran, 1,4-dioxane, and acetonitrile.

[0015] Preferably, the reaction time is 1-24 h.

[0016] Preferably, the purification method is column chromatography.

[0017] Preferably, the stationary phase used in column chromatography is silica gel, and the eluent is a mixed solvent of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is dichloromethane:methanol = (5-50):1.

[0018] Thirdly, the present invention provides a selenium-containing thin film, which is obtained by mixing a substrate, an oxidant, a diselenium compound, a melanin precursor, a reducing agent, and an alkali. Whether the reducing agent, alkali, melanin precursor, and oxidant are added is not specified.

[0019] The substrate includes one or more organic polymer materials, inorganic non-metallic materials, polymer materials, and composite materials, such as metallic materials, non-metallic inorganic materials, metallic materials, semiconductors, and electrodes. Optionally, it may include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, polyurethane, polytetrafluoroethylene, ceramics, silicon, silicon oxide, silicon nitride, alumina, glass slides, quartz slides, gold, silver, copper, aluminum, titanium, glassy carbon electrodes, etc.

[0020] Melanin monomers include at least one of dopamine, L-L-dopa, catechol, 1,8-dihydroxynaphthalene, tyrosine, homohovanillic acid, phenylalanine, 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, 5-S-cysteine-dopa, 1,4,6,7,9,12-hexahydroxyperylquinone, tyramine, adrenaline, and noradrenaline.

[0021] Oxidizing agents include at least one of potassium permanganate, oxygen, sodium periodate, ammonium persulfate, sodium periodate, hydrogen peroxide, sodium hypochlorite, potassium persulfate complex salt, ruthenium tetroxide, cerium ammonium nitrate, manganese dioxide, selenium dioxide, peroxybenzoic acid, m-chloroperoxybenzoic acid, peracetic acid, potassium dichromate, pyridine dichromate, ruthenium tetroxide, cobalt tetrapyridine dichromate, dimethyl sulfoxide, benzoyl peroxide, Des Martin periodane, 2,3-dichloro-5,6-dicyano-p-benzoquinone, methyl (trifluoromethyl)dioxane, and dimethyl peroxide.

[0022] The reducing agent is at least one of sodium sulfite, ferrous sulfate, stannous chloride, oxalic acid, potassium borohydride, sodium borohydride, lithium aluminum hydride, and tris(2-carboxyethyl)phosphonic acid.

[0023] Preferably, the molar ratio of the oxidant to the diselenium compound is (1-5):1.

[0024] Preferably, the solvent is water.

[0025] The preferred location has a reaction time of 1-72 hours.

[0026] Compared with the prior art, the beneficial effects of the present invention are: Synthetic aspects: This invention innovatively designs a molecular skeleton that combines catechol adhesion units and diselenide structural units. It adopts a synthetic route that directly reacts the compound of formula (II) with inorganic diselenide, eliminating the need for complex protection-deprotection operations on phenolic hydroxyl groups. The reaction conditions are mild and the functional groups are well tolerated, effectively solving the problems of poor compatibility between catechol and diselenide bonds, lengthy routes, and low efficiency in traditional synthesis. The product is easy to purify, with a yield of up to 60%, and has good versatility and industrial application potential.

[0027] In terms of material performance: This invention utilizes the oxidative polymerization characteristics of catechol in diselenoside compounds through a "molecular design-controllable film formation" strategy to directly construct selenium-containing films on the substrate surface. This achieves uniform molecular-level dispersion and chemical bonding of selenium in the film, fundamentally solving the defects of uneven selenium component distribution, weak bonding with the substrate, and easy leaching and deactivation in existing technologies. At the same time, the introduction of diselenoside bonds significantly improves the antioxidant properties and long-term stability of the film, while the catechol units ensure strong adhesion of the film to various substrates, making the film both multifunctional and highly durable.

[0028] Applications: Selenium-containing thin films have a wide range of substrate applications, compatible with various materials such as organic polymers, inorganic non-metals, metals, and electrodes. The film formation conditions are mild and do not require complex equipment. They can be widely used in fields such as coating protection and surface modification of functional materials, with broad application prospects. Attached Figure Description

[0029] Figure 1 This is the synthetic route for the diselenium compounds of this invention.

[0030] Figure 2 This is the carbon spectrum of the product prepared in Example 1.

[0031] Figure 3 This is the hydrogen spectrum of the product prepared in Example 1.

[0032] Figure 4 This is the mass spectrum of the product prepared in Example 1.

[0033] Figure 5 These are photographs of selenium-containing thin films prepared on silicon wafers and quartz wafers in Examples 2 (A) and 3 (B).

[0034] Figure 6 These are scanning electron microscope images (A: planar view; B: cross-sectional view) of the product prepared in Example 2.

[0035] Figure 7 This is the photoelectron spectrum of the product prepared in Example 2. Detailed Implementation

[0036] Example 1 This embodiment provides a method for preparing a diselenocyanin compound, the structural formula of which is shown below, and includes the following steps: First, 0.404 g (5.1 mmol) of selenium (Se) powder, 0.194 g (5.1 mmol) of sodium borohydride, and 2.5 mL of water were added to a 100 mL flask to react and give disodium diselenide (Na₂Se₂). Then, disodium diselenide was mixed with 20 mL of a tetrahydrofuran (THF) solution of 1 g (4.6 mmol) of 4-(2-bromoethyl)-1,2-benzenediol at 50 °C overnight to synthesize bis[2-(3,5-dihydroxyphenyl)ethyl]diselenes. Column chromatography was performed using dichloromethane and methanol as eluents (dichloromethane:methanol = 20:1), with a yield of approximately 60%.

[0037] The carbon spectrum, proton spectrum, and mass spectrum of the obtained product are as follows: Figure 2 , Figure 3 and Figure 4 The structural characterization data are as follows: 1 H NMR (600 MHz, CD3OD) δ 6.67 (d, J = 8.0 Hz, 2H), 6.63 (d, J = 1.9Hz, 2H), 6.51 (dd, J = 8.0, 1.9 Hz, 2H), 3.09 (t, J = 7.8 Hz, 4H), 2.87 (t, J = 7.8 Hz, 4H). 13 C NMR (600 MHz, (CD3)2SO) δ 30.98, 36.66, 115.06, 115.28, 119.50,132.60, 143.40, 144.90. HRMS (m / z) (ESI): C 16 H 17 O4Se 2− : 432.9414. Example 2 Preparation of selenium-containing thin films by ammonium persulfate oxidation under acidic conditions Weigh 2 mg of diselenide compound and 1.33 mg of tris(2-carboxyethyl)phosphonic acid and react them in an ethanol-water solution for 5-30 minutes. Add 4.22 mg of ammonium persulfate, then add the substrate material and react overnight at room temperature (15-25 °C). After growth, remove the sample with tweezers, rinse with water for 20 seconds, and then dry with nitrogen gas to complete the film preparation. Figure 5 As shown in Tables 6, 7 and 1, 2, thin films can be formed on a variety of substrates. Tables 1 and 2 show the elemental composition of the products obtained by X-ray photoelectron spectroscopy.

[0038] Table 1 Table 2 Example 3 Preparation of selenium-containing thin films by ammonium persulfate oxidation under alkaline conditions Weigh 2 mg of diselenide compound and 1.33 mg of tris(2-carboxyethyl)phosphonic acid and react them in an ethanol / sodium carbonate-sodium bicarbonate buffer solution for 5-30 minutes. Add 4.22 mg of ammonium persulfate, then add the substrate material and react overnight at room temperature. After growth, remove the sample with tweezers, rinse with water for 20 seconds, and then dry with nitrogen gas to complete the film preparation.

[0039] Example 4 Preparation of selenium-containing thin films by air oxidation under alkaline conditions Weigh 2 mg of the diselenide compound and dissolve it in an ethanol / Tris buffer solution. Add the solution to the substrate and allow it to react overnight at room temperature. After growth, remove the sample with tweezers, rinse with water for 20 seconds, and then dry with nitrogen to complete the film preparation.

[0040] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to the above embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing a bis-seleno compound, characterized by, The process includes the following steps: mixing compound (II), inorganic diselenide, and solvent to react and obtain compound (I); （Ⅱ） （Ⅰ） Wherein, X is selected from one of -OTs, -OMs, -OTf, -ONO2, -OAc, -N2⁺, -SR2⁺, -I, -Br, -Cl; R1, R2, R3, and R4 may be the same or different, and each is independently selected from one of the following: -COOH, -H, -OH, -CH3, -CH(CH3)2, -C(CH3)3, -OCH3, -NH2, -CONH2, -CN, -NO2, -CHO, -SO3H, -F, -Cl, -Br, -I, -CF3, -CCl3, -N(CH3)2, -NHCOCH3, -OCOCH3, -C6H5, -COCH3, -COOCH3, -CH=CH2, and -CH2NO. n and m are natural numbers greater than or equal to 1; In formulas (I) and (II), the phenolic hydroxyl groups on the benzene ring structure are located at any position on the benzene ring, and the number of phenolic hydroxyl groups is 1-5.

2. The production method according to claim 1, characterized by, n and m take values ​​from 1 to 30.

3. The production method according to claim 1, characterized by, The inorganic diselenide is at least one of disodium diselenide and disodium diselenide.

4. The method of claim 1, wherein, The reaction temperature is 30-100 ℃, and the reaction time is 1-24 h; the molar ratio of diselenide and compound (II) is (1-5):1; the solvent is an organic solvent selected from at least one of N,N-dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, dichloromethane, 2-methyltetrahydrofuran, 1,4-dioxane, and acetonitrile; the reaction product is purified by column chromatography, with silica gel as the stationary phase and a mixed solvent of dichloromethane and methanol as the eluent, with a volume ratio of (5-50):

1.

5. A selenium-containing thin film, characterized by, It is prepared using a substrate and a diselenium compound obtained by any one of the preparation methods described in claims 1-5 as the core raw material; the substrate is selected from one or more of metallic materials, non-metallic inorganic materials, polymeric materials, and composite materials. The substrate is selected from one of organic polymeric materials, inorganic non-metallic materials, metallic materials, composite materials, carbon-based materials, semiconductors, and electrodes.

6. The selenium-containing thin film according to claim 5, wherein The substrate is selected from one of the following materials: polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, polyurethane, polytetrafluoroethylene, ceramics, silicon wafers, silicon oxide, silicon nitride, alumina, glass, quartz wafers, gold, silver, copper, aluminum, titanium, and glassy carbon. Among these, polyethylene and polypropylene are polymer materials, ceramics and silicon wafers are non-metallic inorganic materials, and gold and silver are metallic materials. The substrate is an electrode made of one of the following materials: polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, polyurethane, polytetrafluoroethylene, ceramics, silicon wafers, silicon oxide, silicon nitride, alumina, glass, quartz wafers, gold, silver, copper, aluminum, titanium, and glassy carbon.

7. The selenium-containing thin film according to claim 5, wherein The reaction conditions for preparing the selenium-containing thin film also include one or more of a reducing agent, an alkali, a melanin precursor, and an oxidizing agent.

8. The selenium-containing thin film according to claim 7, characterized in that, Melanin precursors include at least one of dopamine, L-L-dopa, catechol, 1,8-dihydroxynaphthalene, tyrosine, homohovanillic acid, phenylalanine, 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, 5-S-cysteine-dopa, 1,4,6,7,9,12-hexahydroxyperylquinone, tyramine, adrenaline, and noradrenaline; The oxidizing agents include at least one of potassium permanganate, oxygen, sodium periodate, ammonium persulfate, hydrogen peroxide, sodium hypochlorite, potassium peroxymonosulfate complex salt, ruthenium tetroxide, cerium ammonium nitrate, manganese dioxide, selenium dioxide, peroxybenzoic acid, m-chloroperoxybenzoic acid, peracetic acid, potassium dichromate, pyridine dichromate, cobalt tetrapyridine dichromate, dimethyl sulfoxide, benzoyl peroxide, Des Martin periodoyl alkyl, 2,3-dichloro-5,6-dicyano-p-benzoquinone, methyl (trifluoromethyl)dioxane, and dimethyl peroxide. The reducing agent includes at least one of sodium sulfite, ferrous sulfate, stannous chloride, oxalic acid, potassium borohydride, sodium borohydride, lithium aluminum hydride, and tris(2-carboxyethyl)phosphonic acid hydrochloride.

9. The selenium-containing thin film according to claim 7, wherein The solvent for preparing the selenium-containing thin film is water, and the reaction time is 1-72 hours; the molar ratio of oxidant to diselenium compound is (1-5):1.

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