A method for synthesizing high-purity tungsten complex

Abstract

This invention provides a method for synthesizing high-purity tungsten complexes, relating to the field of chemical synthesis technology. Under a nitrogen atmosphere, tungsten hexachloride and an alkane solvent are added to a reaction vessel, the temperature is lowered to 0°C, tert-butylamine is added dropwise, the mixture is brought back to room temperature with stirring, filtered, and washed to obtain a filtrate. Trimethylchlorosilane is added dropwise to the filtrate, the reaction is heated, and after returning to room temperature, pyridine is added dropwise. The reaction yields (…). t The intermediate BuN)2WCl2(py)2 is synthesized by adding toluene and dialkylamine. After reaction, the mixture is filtered, washed, the solvent is evaporated, and then distilled to obtain a high-purity tungsten complex. By optimizing the reaction conditions and raw material ratio, the synthesis method of this invention significantly improves the yield of the high-purity tungsten complex. Compared with the prior art, it effectively reduces the waste of raw materials, improves production efficiency, and successfully achieves a product metal purity of 5N, meeting the stringent requirements of the semiconductor field for product metal purity and helping to improve the performance and quality of subsequent application products.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical synthesis, and more specifically, particularly relates to a method for synthesizing a high-purity tungsten complex. Background Art

[0002] In today's material science and semiconductor industry, two-dimensional layered transition metal sulfides have attracted much attention due to their unique properties. Among them, tungsten sulfide (WS2) has shown broad application prospects in many fields such as solar cells and semiconductors due to its high electron mobility, excellent optical absorption and quantum Hall effect. Atomic layer deposition (ALD) technology, as an important means of preparing high-quality WS2 thin films, has extremely high requirements on the performance of the precursor.

[0003] The synthesis of high-quality ALD precursor tungsten complexes has become a key link. However, the existing synthesis methods of bis(tert-butylamine)bis(dimethylamine)tungsten (VI) have many shortcomings. For example, some synthesis routes have complicated reaction steps and require the individual separation of the intermediates in each step, which not only increases the complexity of the operation but also leads to a low yield of the final product. The raw materials used in some methods are expensive, such as specific amine compounds, which greatly increases the production cost.

[0004] At the same time, the reagents used in some reactions pose safety risks, such as flammable substances, extremely sensitive to air, and highly exothermic when added, which bring great risks to production. In addition, due to improper selection of raw materials in some synthetic routes, metal residues are easily left in the product, affecting the purity of the product and increasing the purification cost.

[0005] In summary, the existing synthesis methods have many problems in terms of economy, safety and industrial application, and it is difficult to meet the growing market demand and industrial development requirements. Therefore, developing a new synthesis method of high-purity tungsten complexes to solve the defects of the existing technology has important practical significance and application value. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for synthesizing a high-purity tungsten complex to solve the above problems.

[0007] A method for synthesizing a high-purity tungsten complex comprises the following steps:

[0008] S1: Under the protection of nitrogen atmosphere, add tungsten hexachloride and alkane solvent into the reaction container, and cool the system to 0°C;

[0009] S2: Slowly add tert-butylamine to the product obtained in S1. After the addition is complete, the system turns into a yellow turbid liquid, and then slowly returns to room temperature while continuing to stir;

[0010] S3: filtering the material obtained after the stirring in S2 in anhydrous and oxygen-free manner, and washing with an alkane solvent to obtain a dark brown filtrate;

[0011] S4: Trimethylchlorosilane was added dropwise to the filtrate in S3 at room temperature, and the system gradually turned into a brown-yellow turbid liquid. After the addition was completed, the external temperature of the system was raised to 50°C for heating reaction. After returning to room temperature, pyridine was added dropwise. After the addition was completed, the reaction was carried out at room temperature to obtain ( t BuN)2WCl2(py)2 intermediate;

[0012] S5: Add toluene and dialkylamine to the intermediate obtained in S4, react at -20 to 60°C, filter in anhydrous and oxygen-free conditions after the reaction, wash with an alkane solvent, evaporate the solvent and perform distillation to obtain a light yellow high-purity tungsten complex.

[0013] Preferably, the molar ratio of tungsten hexachloride to tert-butylamine, trimethylchlorosilane, pyridine and dialkylamine is 1:(11-12):(2-3):(2-3):(5-7).

[0014] Preferably, the alkane solvent is one of n-hexane, n-pentane and n-heptane.

[0015] Preferably, the dialkylamine in S5 is one of dimethylamine, diethylamine and methylethylamine.

[0016] Preferably, the stirring time after tert-butylamine is added dropwise in S2 is 10 hours.

[0017] Preferably, the reaction time of heating reaction after adding trimethylsilyl chloride in S4 is 3 hours.

[0018] Preferably, the reaction time after the pyridine is added dropwise in S4 is 12 hours.

[0019] Preferably, in S5, the reaction time after adding toluene and dialkylamine is 12 hours.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Significantly improved product yield: By optimizing the reaction conditions and raw material ratio, the synthesis method of the present invention greatly improves the yield of high-purity tungsten complexes. Compared with the existing technology, it effectively reduces the waste of raw materials and improves production efficiency.

[0022] 2. Ensure high metal purity: The product metal purity has successfully reached 5N, meeting the strict requirements of the semiconductor field on product metal purity, which will help improve the performance and quality of subsequent application products.

[0023] 3. Simplified reaction steps: The one-pot method and other simple synthesis processes are adopted to reduce the separation and purification operations of intermediate products, and reduce the operation complexity and labor intensity.

[0024] 4. Reduced production costs: Common and relatively inexpensive raw materials are used to avoid the use of expensive reagents, while increasing the yield and reducing production costs overall.

[0025] 5. Improved production safety: Avoiding the use of flammable, air-sensitive and dangerous reagents significantly reduces safety risks in the production process and ensures the life safety of operators and production safety of the factory.

[0026] 6. Broadened the range of raw material selection: Different dialkylamines can be flexibly selected, which increases the applicability and flexibility of the synthesis method and meets different production needs.

[0027] 7. The reaction conditions are mild and controllable: the reaction temperature is between -20 and 60°C, which is easy to control and achieve, reducing the dependence on special equipment and harsh conditions and facilitating industrial promotion.

[0028] 8. Promoted industrial production: Simple and easy operation process, lower cost and higher safety make it more suitable for large-scale industrial production and help promote the development of related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0030] The invention relates to a method for synthesizing a high-purity tungsten complex, aiming to solve many problems existing in the prior art and provide a synthesis route with easy-to-obtain raw materials, simple operation, mild conditions, low cost, high safety factor and high yield, so as to meet the needs of industrial large-scale production.

[0031] The synthetic method of the present invention comprises the following steps:

[0032] Under nitrogen atmosphere, tungsten hexachloride and n-hexane were added to the reaction container, the temperature was lowered to 0°C, tert-butylamine was added dropwise, the temperature was restored to room temperature and stirred, and the filtrate was obtained by filtering and washing.

[0033] Trimethylsilyl chloride was added dropwise to the filtrate, heated for reaction, and pyridine was added dropwise after returning to room temperature to obtain ( t BuN)2WCl2(py)2 intermediate.

[0034] Toluene and dialkylamine are added to the intermediate, and after the reaction, the intermediate is filtered, washed, the solvent is evaporated and distilled to obtain a high-purity tungsten complex.

[0035] The molar ratio of tungsten hexachloride to tert-butylamine, trimethylchlorosilane, pyridine and dialkylamine is 1:(11-12):(2-3):(2-3):(5-7), the temperature of the reaction system is controlled at -20-60°C, and the alkane solvent is n-hexane, n-pentane or n-heptane.

[0036] In order to illustrate the synthesis method of the present invention in more detail, a number of specific examples are listed below and compared with comparative examples in the prior art.

[0037] Embodiment 1:

[0038] Tungsten hexachloride (142.7 g, 0.36 mol) and 1.5 L of n-hexane were added to a 3000 ml multi-mouth reaction bottle under nitrogen atmosphere. The temperature was lowered to 0 °C. Tert-butylamine (299.5 g, 4.1 mol) was added dropwise to the reaction system. The system turned into a yellow turbid liquid. After slowly returning to room temperature and stirring for 10 hours, it was filtered without water or oxygen and washed with n-hexane to obtain a dark brown filtrate.

[0039] Trimethylsilyl chloride (97.9 g, 0.9 mol) was added dropwise to the filtrate at room temperature. The system slowly turned into a brown-yellow turbid liquid. After the addition was completed, the reaction was heated at an external temperature of 50 °C for 3 hours. The reaction was then restored to room temperature and pyridine (71.2 g, 0.9 mol) was added dropwise. After the addition was completed, the reaction was continued at room temperature for 12 hours. The product was filtered in anhydrous and oxygen-free conditions to obtain ( t BuN)2WCl2(py)2 intermediate 173.6 g, yield 87%.

[0040] For intermediates ( t BuN)2WCl2(py)2 was characterized by NMR 1 HNMR (C6D6): 9.05 (m, 4H), 6.83 (m, 2H), 6.52 (m, 4H), 1.55 (s, 18H).

[0041] In a 2000 ml reaction flask under nitrogen, add ( t BuN)2WCl2(py)2 (88.8 g, 0.16 mol), 800 ml of toluene, cooled to -10 ℃, liquefied dimethylamine (43.3 g, 0.96 mol) was added dropwise, and after the addition was completed, the mixture was slowly restored to room temperature and stirred for 12 hours, filtered in anhydrous and oxygen-free conditions, washed with n-hexane, and the filtrate was evaporated to dryness. The crude product was further distilled to obtain 60.3 g of a light yellow product, bis(tert-butylamine)bis(dimethylamine)tungsten, with a yield of 91%.

[0042] NMR characterization of the product bis(tert-butylamine)bis(dimethylamine)tungsten 1HNMR (C6D6): 3.50 (s, 12H), 1.40 (s, 18H).

[0043] The purity of the product bis(tert-butylamine)bis(dimethylamine)tungsten was detected by inductively coupled plasma mass spectrometry (ICP-MS), and the results showed that the metal purity of the product was 5N.

[0044] Embodiment 2:

[0045] Under nitrogen atmosphere, tungsten hexachloride (142.7 g, 0.36 mol) and 1.5 L of n-hexane were added to a 5000 ml multi-mouth reaction bottle, and the temperature was lowered to 0 °C. Tert-butylamine (299.5 g, 4.1 mol) was added dropwise to the reaction system. The system turned into a yellow turbid liquid. After slowly returning to room temperature and stirring for 10 hours, it was filtered without water or oxygen, washed with n-hexane, and a dark brown filtrate was obtained.

[0046] Trimethylsilyl chloride (97.9 g, 0.9 mol) was added dropwise to the filtrate at room temperature. The system slowly turned into a brown-yellow turbid liquid. After the addition was completed, the mixture was heated at an external temperature of 50 °C for 3 hours. The mixture was then returned to room temperature and pyridine (71.2 g, 0.9 mol) was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 12 hours.

[0047] Add 500 ml of toluene to the bottle, cool to -10 °C, and add liquefied dimethylamine (97.4 g, 2.16 mol) dropwise. After the addition is complete, slowly return to room temperature and stir for 12 hours. Filter in anhydrous and oxygen-free conditions, wash with n-hexane, evaporate the filtrate to dry the solvent, and further distill the crude product to obtain 126.8 g of a light yellow product, bis(tert-butylamine)bis(dimethylamine)tungsten, with a yield of 85%.

[0048] Embodiment 3:

[0049] Under nitrogen atmosphere, tungsten hexachloride (142.7 g, 0.36 mol) and 1.5 L of n-hexane were added to a 5000 ml multi-mouth reaction bottle, and the temperature was lowered to 0 °C. Tert-butylamine (299.5 g, 4.1 mol) was added dropwise to the reaction system. The system turned into a yellow turbid liquid. After slowly returning to room temperature and stirring for 10 hours, it was filtered without water or oxygen, washed with n-hexane, and a dark brown filtrate was obtained.

[0050] Trimethylsilyl chloride (97.9 g, 0.9 mol) was added dropwise to the filtrate at room temperature. The system slowly turned into a brown-yellow turbid liquid. After the addition was completed, the mixture was heated at an external temperature of 50 °C for 3 hours. The mixture was then returned to room temperature and pyridine (71.2 g, 0.9 mol) was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 12 hours.

[0051] Add 500 ml of toluene to the bottle, cool to -10 °C, and add diethylamine (158 g, 2.16 mol) dropwise. After the addition is complete, slowly return to room temperature and stir for 12 hours. Filter in anhydrous and oxygen-free conditions, wash with n-hexane, evaporate the filtrate to dry the solvent, and further distill the crude product to obtain 149 g of a light yellow product, bis(tert-butylamine)bis(diethylamine)tungsten, with a yield of 88%.

[0052] NMR characterization of the product bis(tert-butylamine)bis(diethylamine)tungsten 1 HNMR (C6D6): 3.64 (q, 8H), 1.41 (s, 18H), 1.25 (t, 12H).

[0053] Embodiment 4:

[0054] Tungsten hexachloride (142.7 g, 0.36 mol) and 1.5 L of n-hexane were added to a 5000 ml multi-mouth reaction bottle under nitrogen atmosphere. The temperature was lowered to 0°C. Tert-butylamine (299.5 g, 4.1 mol) was added dropwise to the reaction system. The system turned into a yellow turbid liquid. After slowly returning to room temperature and stirring for 10 hours, it was filtered in anhydrous and oxygen-free conditions and washed with n-hexane to obtain a dark brown filtrate.

[0055] Trimethylsilyl chloride (97.9 g, 0.9 mol) was added dropwise to the filtrate at room temperature. The system slowly turned into a brown-yellow turbid liquid. After the addition was completed, the mixture was heated at an external temperature of 50 °C for 3 hours. The mixture was then returned to room temperature and pyridine (71.2 g, 0.9 mol) was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 12 hours.

[0056] Add 500 ml of toluene to the bottle, cool to -10 °C, add methylethylamine (127.7 g, 2.16 mol) dropwise, and after the addition is complete, slowly return to room temperature and stir for 12 hours. Filter in anhydrous and oxygen-free conditions, wash with n-hexane, evaporate the filtrate to dry the solvent, and further distill the crude product to obtain 129 g of a light yellow product, bis(tert-butylamine)bis(methylethylamine)tungsten, with a yield of 81%.

[0057] NMR characterization of the product bis(tert-butylamine)bis(methylethylamine)tungsten 1 HNMR (C6D6): 3.71 (q, 4H), 3.50 (s, 6H), 1.41 (s, 18H), 1.19 (t, 6H).

[0058] Comparative Example 1:

[0059] Under nitrogen atmosphere, tungsten hexachloride (142.7 g, 0.36 mol) and 1.5 L of n-hexane were added to a 5000 ml multi-mouth reaction bottle, and the temperature was lowered to 0 °C. Tert-butylamine (299.5 g, 4.1 mol) was added dropwise to the reaction system. The system turned into a yellow turbid liquid. After slowly returning to room temperature and stirring for 10 hours, it was filtered without water or oxygen, washed with n-hexane, and a dark brown filtrate was obtained.

[0060] Trimethylsilyl chloride (97.9 g, 0.9 mol) was added dropwise to the filtrate at room temperature. The system slowly turned into a brown-yellow turbid liquid. After the addition was completed, the mixture was heated at an external temperature of 50 °C for 3 hours. The mixture was then returned to room temperature and pyridine (71.2 g, 0.9 mol) was added dropwise. After the addition was completed, the mixture was reacted at room temperature for 12 hours.

[0061] Add 500 ml of toluene to the bottle, cool to -10 °C, and add dropwise to a 10% by mass solution of lithium dimethylamine in n-hexane (477.3 g, 0.9 mol). After the addition is complete, slowly return to room temperature and stir for 12 hours. Filter in anhydrous and oxygen-free conditions, wash with n-hexane, evaporate the filtrate to dry the solvent, and further distill the crude product to obtain 132.7 g of a light yellow product with a yield of 89%.

[0062] The purity of the product bis(tert-butylamine)bis(dimethylamine)tungsten was tested using inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the product contained 56 ppm of lithium and the metal purity was 4N.

[0063] In order to more intuitively demonstrate the advantages of the synthesis method of the present invention, the data of the embodiments and comparative examples are organized into a table for comparison below:

[0064]

[0065] As can be seen from the above table, the synthesis method of the present invention has obvious advantages in terms of yield and metal purity. In particular, in terms of metal purity, the method of the present invention can reach 5N, while in Comparative Example 1, lithium dimethylamide is used as the raw material, and the metal purity is only 4N.

[0066] First, from the technical perspective, there are a variety of synthetic routes in the prior art, but all of them have various defects, such as low yield, expensive raw materials, complex reaction steps, poor safety, etc. The present invention breaks the traditional thinking mode and creatively proposes a new synthetic route by carefully selecting and optimizing the reaction raw materials, reaction steps and reaction conditions.

[0067] In the selection of reaction raw materials, expensive and difficult-to-obtain raw materials are abandoned, and common and relatively cheap tungsten hexachloride, tert-butylamine, trimethylsilyl chloride, pyridine, etc. are used, which greatly reduces the cost. At the same time, the flexible selection of dialkylamines, such as dimethylamine, diethylamine, methylethylamine, etc., broadens the possibility and adaptability of synthesis, and provides a variety of solutions for different needs.

[0068] By rationally arranging the reaction sequence and optimizing the reaction conditions, such as strictly controlling the reaction temperature, reaction time and raw material ratio, efficient conversion and high-purity products are achieved. Compared with the cumbersome multi-step separation and complex operation in the prior art, the synthesis method of the present invention is more concise and smooth, reduces the loss and pollution in the intermediate links, and improves the yield and purity of the product.

[0069] In terms of safety, the present invention avoids the use of flammable, air-sensitive and dangerous reagents such as lithium dimethylamide, significantly reducing the safety risks in the production process. This emphasis on and improvement of safety is a major breakthrough in the prior art and provides a reliable guarantee for industrial production.

[0070] From the experimental data and results, the successful implementation of multiple embodiments and the sharp contrast with the comparative examples fully demonstrate the superiority of the method of the present invention. The advantages of high yield, high metal purity and mild reaction conditions not only solve the problems in the prior art, but also provide new ideas and methods for the development of related fields.

[0071] In addition, the creativity of the present invention is also reflected in its adaptability to industrial production. The simple and easy operation process, low cost and high safety enable the synthesis method of the present invention to be applied in large-scale industrial production, and has huge potential economic value and social value.

[0072] Compared with the prior art, the present invention is not a simple improvement or combination of existing methods, but fundamentally proposes a new, systematic and efficient synthesis strategy. This creative method not only opens up a new way for the preparation of high-purity tungsten complexes, but also injects new vitality into the development of related industries, and is expected to promote technological progress and innovation in the entire field.

[0073] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A method for synthesizing a high-purity tungsten complex, characterized in that: The following steps are involved: S1: Under the protection of nitrogen atmosphere, add tungsten hexachloride and alkane solvent into the reaction container, and cool the system to 0°C; S2: Slowly add tert-butylamine to the product obtained in S1. After the addition is complete, the system turns into a yellow turbid liquid, and then slowly returns to room temperature while continuing to stir; S3: filtering the material obtained after the stirring in S2 in anhydrous and oxygen-free manner, and washing with an alkane solvent to obtain a dark brown filtrate; S4: Trimethylchlorosilane was added dropwise to the filtrate in S3 at room temperature, and the system gradually turned into a brown-yellow turbid liquid. After the addition was completed, the external temperature of the system was raised to 50°C for heating reaction. After returning to room temperature, pyridine was added dropwise. After the addition was completed, the reaction was carried out at room temperature to obtain ( t BuN)2WCl2(py)2 intermediate; S5: adding toluene and dialkylamine to the intermediate obtained in S4, reacting at -20 to 60°C, filtering in anhydrous and oxygen-free conditions after the reaction, washing with an alkane solvent, evaporating the solvent and rectifying to obtain a light yellow high-purity tungsten complex; Wherein, the molar ratio of tungsten hexachloride to tert-butylamine, trimethylchlorosilane, pyridine and dialkylamine is 1:(11-12):(2-3):(2-3):(5-7); The alkane solvent is one of n-hexane, n-pentane and n-heptane; The dialkylamine in S5 is one of dimethylamine, diethylamine and methylethylamine; The products prepared by the synthesis method of a high-purity tungsten complex are: light yellow product bis(tert-butylamine)bis(dimethylamine)tungsten, light yellow product bis(tert-butylamine)bis(diethylamine)tungsten and light yellow product bis(tert-butylamine)bis(methylethylamine)tungsten.

2. A method for synthesizing a high-purity tungsten complex as claimed in claim 1, characterized in that: After tert-butylamine was added dropwise to S2, the stirring time was 10 hours.

3. A method for synthesizing a high-purity tungsten complex as claimed in claim 1, characterized in that: The reaction time of heating reaction after adding trimethylsilyl chloride dropwise in S4 is 3 hours.

4. A method for synthesizing a high-purity tungsten complex as claimed in claim 1, characterized in that: The reaction time after pyridine was added dropwise in S4 was 12 hours.

5. A method for synthesizing a high-purity tungsten complex as claimed in claim 1, characterized in that: In S5, the reaction time after adding toluene and dialkylamine is 12 hours.

Images