Synthesis method and use of stannous complex

Abstract

The present invention discloses a method for synthesizing a stannous complex, which belongs to the technical field of organic synthesis and comprises the following steps: Step S1, in an inert gas atmosphere, mixing SnCl2, a solvent and an amino alcohol to obtain a reaction system A; the amino alcohol structural formula is R 1 R 2 NCH2CR 3 R 4 OH; Step S2, adding a base to reaction system A, and after complete addition, reflux and stir the reaction to obtain reaction system B; Step S3, filtering and separating reaction system B, and purifying it by distillation to obtain a stannous complex. This synthesis method is simple to operate, has a high yield, and is suitable for scale-up production. The stannous complex can be used to prepare semiconductor thin film materials.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of a stannous complex and application thereof. Background Art

[0002] Over the past few decades, with the development of semiconductor materials, metal oxide semiconductors have garnered significant attention and are widely used in thin-film transistors (TFTs), gas sensors, lithium batteries, and solar cells. Among these, n-type oxides, such as ZnO, SnO2, ZnSnO, InGaZnO, and WO3, have attracted considerable research due to their stability, while p-type oxides, such as SnO and Cu2O, have been less studied due to their processing difficulties. However, p-type oxides are crucial in semiconductor device manufacturing, as they are used in pn junctions and CMOS. SnO, due to its wide optical bandgap (2.7-3.0 eV), also holds promise as a transparent conductive oxide (TCO).

[0003] According to existing reports, SnO can be obtained from a Sn precursor and H2O through atomic layer deposition (ALD). Currently developed Sn precursors include Sn(dmamp)2, Sn(dmamb)2, etc. Taking Sn(dmamp)2 as an example, its synthesis method is: first, SnCl2 is reacted with lithium bis(trimethylsilyl)amide [LiN(SiMe3)2] in tetrahydrofuran, and then the intermediate Sn[N(SiMe3)2]2 is obtained through separation and purification, and then reacted with a ligand to obtain a Sn precursor (Dalton Trans., 2021, 50, 13902-13914; J. Chem. Soc., Chem. Commun., 1983, 639-641.). This synthesis method can be used to synthesize Sn(dmamp)2 in small batches (tens of grams), and the yield is comparable to that reported in the literature (Dalton Trans., 2021, 50, 13902-13914, yield 64%). However, in the scaled-up synthesis (hundreds of grams), due to the poor thermal stability of the intermediate Sn[N(SiMe3)2]2, the scaled-up synthesis of the intermediate has low yield, poor purity, and difficult post-processing. For example, in Comparative Example 2 in the embodiment, the scaled-up synthesis yield of the intermediate is 36%, which directly affects the yield and purity of the final product, making it difficult to obtain qualified products. Finding a method for synthesizing stannous complexes that is stable in process and can be scaled up for production is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of the present invention is to provide a synthesis method of a stannous complex and its application, so as to solve the problem that it is difficult to achieve scale-up production of stannous precursors.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for synthesizing a stannous complex comprises the following steps:

[0007] Step S1, under an inert gas atmosphere, mixing SnCl2, a solvent and an amino alcohol to obtain a reaction system A;

[0008] Step S2, adding a base to the reaction system A, and after the addition, refluxing and stirring to react to obtain the reaction system B;

[0009] Step S3: filtering and separating the reaction system B, and purifying it by distillation to obtain a stannous complex.

[0010] As a preferred technical solution of the present invention, the amino alcohol structural formula is R 1 R 2 NCH2CR 3 R 4 OH, where R 1 、R 2 、R 3 、R 4 For alkyl.

[0011] Among them, the R 1 、R 2 、R 3 、R 4 independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

[0012] As a preferred technical solution of the present invention, the inert gas atmosphere is one of nitrogen or argon.

[0013] As a preferred technical solution of the present invention, the solvent is selected from one or more of toluene, ether, tetrahydrofuran, ethylene glycol dimethyl ether, and methyl tert-butyl ether.

[0014] As a preferred technical solution of the present invention, the base is one or more of methyl lithium, butyl lithium, methyl magnesium bromide, and ethyl magnesium bromide.

[0015] As a preferred technical solution of the present invention, the base is added dropwise, and the temperature of the reaction system B is controlled to be maintained at -50°C to -20°C during the addition process.

[0016] As a preferred technical solution of the present invention, the molar ratio of SnCl2 to amino alcohol is 1:2 to 1:3.

[0017] As a preferred technical solution of the present invention, the feeding amount of the base is: 2n(SnCl2)≤n(base)≤n(amino alcohol); n is the number of moles.

[0018] As a preferred technical solution of the present invention, the volume ratio of the amino alcohol to the solvent is 1:1 to 1:100.

[0019] The stannous complex prepared by the above synthesis method is used in the preparation of semiconductor thin film materials.

[0020] Beneficial effects of the present invention:

[0021] (1) This invention provides a method for synthesizing a stannous complex. In this method, SnCl2 is first subjected to a coordination reaction with an amino alcohol, and then a base is added to obtain the stannous complex. Compared with the prior art, the present invention does not require the step of separating the intermediates, and the operation is simple.

[0022] (2) The method for synthesizing a stannous complex of the present invention has a higher yield than that of the prior art. In the prior art method, SnCl2 is prepared into a Sn[N(SiMe3)2]2 intermediate with poor thermal stability. In this method, there are problems of low yield and high impurities when the intermediate is synthesized in large quantities. The method of the present invention not only has a higher yield, but also has a higher purity of the obtained product, which can be better applied to the preparation of semiconductor thin film materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] Figure 1 The embodiment of the present invention 1 1 H NMR spectrum;

[0025] Figure 2 It is the thermogravimetric spectrum of the intermediate in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0027] A method for synthesizing a stannous complex comprises the following steps:

[0028] Step S1, under an inert gas atmosphere, mixing SnCl2, a solvent and an amino alcohol to obtain a reaction system A;

[0029] Step S2, adding a base to the reaction system A, and after the addition, refluxing and stirring to react to obtain the reaction system B;

[0030] Step S3: filtering and separating the reaction system B, and purifying it by distillation to obtain a stannous complex.

[0031] Wherein, the amino alcohol structural formula is R 1 R 2 NCH2CR 3 R 4 OH, where R 1 、R 2 、R 3 、R 4 is an alkyl group. 1 、R 2 、R 3 、R 4 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl. 1 =R 2 =R 3 =R 4 =Me, the amino alcohol structural formula is Me2NCH2CMe2OH, abbreviated as dmampH; when R 1 =R 2 =R 3 =Me, R 4 =Et, the amino alcohol structural formula is Me2NCH2CMeEtOH, abbreviated as dmambH.

[0032] The inert gas atmosphere is nitrogen or argon.

[0033] Wherein, the solvent is selected from one or more of toluene, ether, tetrahydrofuran, ethylene glycol dimethyl ether, and methyl tert-butyl ether.

[0034] Wherein, the base is one or more of methyl lithium, butyl lithium, methyl magnesium bromide, and ethyl magnesium bromide.

[0035] The base is added dropwise, and the temperature of the reaction system B is controlled to be maintained at -50°C to -20°C during the addition process.

[0036] Wherein, the molar ratio of SnCl2 to amino alcohol is 1:2 to 1:3.

[0037] The amount of the base added is: 2n(SnCl2)≤n(base)≤n(amino alcohol); n is the number of moles.

[0038] The volume ratio of the amino alcohol to the solvent is 1:1-100.

[0039] Example 1

[0040] Under a nitrogen atmosphere, SnCl2 (570.0 g, 3.0 mol), tetrahydrofuran (4 L), and amino alcohol Me2NCH2CMe2OH (i.e., dmampH) (702.0 g, 6.0 mol) were added to a reactor and reacted at room temperature for 2 hours. The system was then cooled and maintained at -50°C to -30°C, and 2.4 L of butyl lithium (2.5 M, 6.0 mol) was added dropwise. After the addition was completed, the mixture was naturally returned to room temperature and then heated under reflux for 8 hours. After the reaction was completed, the mixture was filtered, and the low-boiling substances in the filtrate were distilled off. The residue was then distilled under reduced pressure to obtain 2903.0 g of the product Sn(dmamp) with a yield of 86%. The product's NMR is shown in Figure 2. Figure 1 As shown, 1 H NMR (400MHz, C6D6, ppm): δ1.39(s,12H,CH3 of C(CH3)2), 2.23(s,12H,CH3 ofN(CH3)2), 2.34(br,4H,CH2).

[0041] Example 2

[0042] Under a nitrogen atmosphere, SnCl₂ (500.0 g, 2.6 mol), tetrahydrofuran (4 L), and the amino alcohol Me₂NCH₂CMe₂OH (dmampH) (457.0 g, 3.9 mol) were added to a reaction vessel and allowed to react at room temperature for 2 h. The system was then cooled and maintained at -50°C to -30°C, and 1.56 L of butyl lithium (2.5 M, 3.9 mol) was added dropwise. After the mixture was allowed to return to room temperature, it was heated under reflux for 8 h. After completion of the reaction, the mixture was filtered, and the filtrate was distilled to remove low-boiling substances. The residue was then distilled under reduced pressure to obtain 2340.3 g of Sn(dmamp) in a 37% yield.

[0043] Example 3

[0044] Under a nitrogen atmosphere, SnCl2 (190.0 g, 1.0 mol), toluene (2 L), and the amino alcohol Me2NCH2CMe2OH (i.e., dmampH) (351.0 g, 3.0 mol) were added to a reaction vessel and allowed to react at room temperature for 1 hour. The system was then cooled and maintained at -30°C to -20°C. 3 L of ethylmagnesium bromide (1 M, 3.0 mol) was added dropwise. After the temperature was naturally returned to room temperature, the mixture was heated under reflux for 6 hours. After completion of the reaction, the mixture was filtered, and the filtrate was distilled to remove low-boiling substances. The residue was then distilled under reduced pressure to obtain 2288.0 g of Sn(dmamp) in an 82% yield.

[0045] Example 4

[0046] Under a nitrogen atmosphere, SnCl2 (190.0 g, 1.0 mol), 1 L of ether, and the amino alcohol Me2NCH2CMeEtOH (i.e., dmambH) (314.0 g, 2.4 mol) were added to a reaction vessel and allowed to react at room temperature for 1 hour. The system was then cooled and maintained at -30°C to -20°C. 1.25 L of methyllithium (1.6 M, 2.0 mol) was added dropwise. After the temperature was naturally returned to room temperature, the mixture was heated under reflux for 6 hours. After completion of the reaction, the mixture was filtered, and the filtrate was distilled to remove low-boiling substances. The residue was then distilled under reduced pressure to obtain 2307.0 g of Sn(dmamb) in an 81% yield.

[0047] Example 5

[0048] Under a nitrogen atmosphere, SnCl₂ (247.0 g, 1.3 mol), 1.5 L of toluene, and the amino alcohol Me₂NCH₂CMeEtOH (i.e., dmambH) (406.8 g, 3.1 mol) were added to a reactor and allowed to react at room temperature for 1 hour. The system was then cooled and maintained at -30°C to -20°C. 1.04 L of n-butyllithium (2.5 M, 2.6 mol) in n-hexane was added dropwise. After the temperature was naturally returned to room temperature, the mixture was heated under reflux for 6 hours. After completion of the reaction, the mixture was filtered, and the filtrate was distilled to remove low-boiling substances. The residue was then distilled under reduced pressure to obtain 2374.6 g of the product Sn(dmamb) in a 76% yield.

[0049] Example 6

[0050] A method for preparing a SnO thin film comprises the following steps:

[0051] (1) The Sn(dmamp)2 precursor and ultrapure water were placed in stainless steel source bottles, respectively. The Sn(dmamp)2 source bottle was heated to 65°C, and the ultrapure water bottle was maintained at room temperature. The bottles were connected to the reaction chamber of the atomic layer deposition equipment through a pipeline, and the pipeline was heated to 90°C to prevent the Sn source from condensing in the pipeline.

[0052] (2) Ultrasonicate the substrate (silicon wafer, quartz, glass) with acetone for 5-20 minutes, ultrasonicate with ethanol for 5-20 minutes, and ultrasonicate with deionized water for 5-20 minutes. After drying with nitrogen, place it in the vacuum reaction chamber of the atomic layer deposition system and evacuate to 1-3 Pa.

[0053] (3) Heat the atomic layer reaction chamber to 200°C and stabilize it for more than half an hour;

[0054] (4) Open the ALD valve of the Sn(dmamp)2 source, use Ar as the carrier gas with a flow rate of 50 sccm, and pass the Sn(dmamp)2 precursor into the reaction chamber in the form of vapor pulses through the carrier gas with a pulse time of 2 s;

[0055] (5) Purge the excess precursors and reaction products in the chamber with Ar for 15 s;

[0056] (6) Open the ALD valve of the water source, use Ar as the carrier gas, with a flow rate of 50 sccm (it can be any flow rate), and pass water into the reaction chamber in the form of vapor pulses through the carrier gas, with a pulse time of 1 s;

[0057] (7) Purge excess water and reaction products in the chamber with Ar for 15 s;

[0058] (8) This forms a cycle of SnO, and steps 4-7 are repeated until the SnO film reaches the target thickness.

[0059] Comparative Example 1

[0060] (Reference Dalton Trans., 2021, 50, 13902-13914)

[0061] Under a N2 atmosphere, SnCl2 (10.0 g, 52.7 mmol) and 100 mL of tetrahydrofuran were added to a reaction kettle, and 105 mL of lithium bis(trimethylsilyl)amide (1 M, 105.0 mmol) was added dropwise to the system. The mixture was refluxed for 2 h. The mixture was filtered, and the filtrate was decompressed to remove low-boiling substances. The residue was extracted with toluene and filtered. The resulting filtrate was distilled under reduced pressure to obtain 19.7 g of the intermediate Sn(N(Si(CH3)3)2)2 with a yield of 85%. The intermediate Sn(N(Si(CH3)3)2)2 was dissolved in n-hexane, and 10.5 g of amino alcohol Me2NCH2CMe2OH (i.e., dmampH) was added. After reacting at room temperature for 6 h, the product was distilled under reduced pressure to obtain 10.7 g of the product with a yield of 68%.

[0062] Comparative Example 2

[0063] Under a nitrogen atmosphere, SnCl2 (190.0 g, 1.0 mol) and 2 L of tetrahydrofuran were added to a reaction vessel. 2 L of lithium bis(trimethylsilyl)amide (1 M, 2 mol) was added dropwise to the system and refluxed for 2 h. The mixture was filtered, and the filtrate was decompressed to remove low-boiling substances. The residue was extracted with toluene and filtered. The filtrate was then decompressed and distilled to obtain 156.0 g of the intermediate Sn(N(Si(CH3)3)2)2 in a 36% yield. During the decompression distillation of the intermediate, an orange solid impurity was distilled out along with the product. For a thermogravimetric spectrum of the intermediate, see [see reference for details]. Figure 2 As shown in Figure 3, the experimental data show that the intermediate begins to decompose significantly at 120 °C.

[0064] The intermediate Sn(N(Si(CH3)3)2)2 was dissolved in n-hexane, and 83.2 g of amino alcohol Me2NCH2CMe2OH (i.e., dmampH) was added. After reacting at room temperature for 6 hours, 59.3 g of product was obtained by distillation with a yield of 48% (the total yield calculated based on the amount of SnCl2 added was 16.9%).

[0065] Comparative Example 1 and Comparative Example 2, we found that the synthesis method of the prior art (reference Dalton Trans., 2021, 50, 13902-13914) can be used to synthesize Sn(dmamp)2 in small batches (several grams to tens of grams), but as the feed increases (hundreds of grams), due to the poor thermal stability of the intermediate Sn[N(SiMe3)2]2, the intermediate has problems of low yield, poor purity, and difficult post-processing, which also directly affects the yield and purity of the final product.

[0066] Comparative Example 3

[0067] Under N2 atmosphere, SnCl2 (10.0 g, 52.7 mmol), sodium aminoalcohol Me2NCH2CMeEtONa (17.2 g, 112.0 mmol), and 100 mL of tetrahydrofuran were added to the reaction kettle and heated under reflux for 12 h. The mixture was filtered and the filtrate was separated and purified to obtain 6.6 g of the product in a yield of 33%.

[0068] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0069] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for synthesizing a stannous complex, characterized in that: The steps include: Step S1: Under an inert gas atmosphere, SnCl2, a solvent and an amino alcohol are mixed to obtain a reaction system A; the amino alcohol structural formula is R 1 R 2 NCH2CR 3 R 4 OH; In the amino alcohol structural formula, R 1 、R 2 、R 3 、R 4 is an alkyl group; Step S2, adding a base to the reaction system A, and after the addition, refluxing and stirring to react to obtain a reaction system B; the base is one or more of methyl lithium, butyl lithium, methyl magnesium bromide, and ethyl magnesium bromide; Step S3: filtering and separating the reaction system B, and purifying it by distillation to obtain a stannous complex.

2. The method for synthesizing a stannous complex according to claim 1, wherein The R 1 、R 2 、R 3 、R 4 independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl and tert-butyl.

3. The method for synthesizing a stannous complex according to claim 1, wherein The solvent is selected from one or more of toluene, ether, tetrahydrofuran, ethylene glycol dimethyl ether, and methyl tert-butyl ether.

4. The method for synthesizing a stannous complex according to claim 1, wherein The base is added dropwise, and the temperature of the reaction system B is controlled to be maintained at -50°C to -20°C during the addition process.

5. The method for synthesizing a stannous complex according to claim 1, wherein The molar ratio of SnCl2 to amino alcohol is 1:2 to 1:

3.

6. The method for synthesizing a stannous complex according to claim 1, wherein The feeding amount of the alkali is: 2n(SnCl2)≤n(alkali)≤n(amino alcohol).

7. The method for synthesizing a stannous complex according to claim 1, wherein The volume ratio of the amino alcohol to the solvent is 1:1-100.

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