Preparation method of mono-substituted cyclopentadienyl yttrium precursor

Abstract

The invention discloses a preparation method of a mono-substituted cyclopentadienyl yttrium precursor, and relates to the field of chemical product preparation, the preparation method of the mono-substituted cyclopentadienyl yttrium precursor comprises the following steps: S1, adding mono-substituted cyclopentadiene into a solution of an alkali metal compound, and then carrying out a heating reaction; s2, dropwise adding the mixture obtained in the step S1 into a solution containing yttrium halide, and carrying out a reflux reaction; and S3, filtering the mixture in S2, and carrying out reduced pressure distillation to remove the solvent. According to the preparation method disclosed by the invention, by changing the solvent and controlling the equivalent weight of reactants and the reaction temperature, the yield can be improved, the purification step can be simplified, and the high-efficiency and large-scale preparation of the mono-substituted cyclopentadienyl yttrium can be realized.

Description

Technical Field

[0001] The present invention relates to the field of chemical product preparation, and in particular to a method for preparing a monosubstituted cyclopentadienyl yttrium precursor. Background Art

[0002] Yttrium-containing oxide films have been widely studied and applied in semiconductor devices and perovskite battery materials due to their excellent properties: wide bandgap, low leakage current, high breakdown voltage, and thermal stability. For example, yttrium-containing oxide films can be used as gate dielectric materials for field-effect transistors. Their high dielectric constant (i.e., high K), high breakdown voltage, and low leakage current can improve gate capacitance, stabilize devices at high voltages, and reduce device power consumption. They can also be used as gate insulating films. Their high breakdown voltage and low leakage current help maintain data stability and reliability in memory cells during high-density integration, while their thermal stability enables them to maintain performance during high-temperature manufacturing processes. They can also be used as high-K dielectric layer materials. Their high dielectric constant can significantly increase the capacitance density of capacitors. Yttrium-containing oxide films can be used as insulating films in metal-insulator-metal (MIM) structures. Their wide bandgap and low leakage current effectively prevent current leakage, thereby improving the device's on / off ratio. Their high breakdown voltage enhances the MIM structure's ability to withstand high voltages.

[0003] Yttrium-containing oxide films are prepared using substituted or unsubstituted cyclopentadienyl yttrium as a precursor via chemical vapor deposition (CVD) or atomic layer deposition (ALD). The conventional route for synthesizing these substituted or unsubstituted cyclopentadienyl yttrium precursors is: YCl3 + RCpNa → Y(RCp)3 + NaCl. This route typically uses tetrahydrofuran or diethyl ether as a coordinating solvent and requires multiple steps to purify the product. This method has low yields and is time-consuming, making it impractical for industrial large-scale synthesis. This significantly reduces the efficiency of the precursor material and limits the application of yttrium-containing oxide films.

[0004] Chinese patent CN2004800228648 discloses a rare earth metal complex, thin film-forming raw materials, and a method for producing thin films. This patent utilizes sodium hydride, sec-butylcyclopentadiene, and yttrium trichloride in a conventional synthesis route, using tetrahydrofuran as a ligand to produce tri(sec-butylcyclopentadienyl)yttrium. However, the yield of the pilot product is only 46%, and the preparation process requires light shielding. Korean patent KR1020230162513 discloses a novel metal precursor for forming thin films using cyclopentadiene and a method for producing the same. This patent utilizes diethyl ether as a ligand to react yttrium chloride with sodium n-butylcyclopentadienyl using a conventional route. Tri(n-butylcyclopentadienyl)yttrium is produced by controlling the reaction temperature below 35°C. However, the yield of this reaction remains low, at only 50%. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a monosubstituted cyclopentadienyl yttrium precursor to solve the following technical problems:

[0006] How to improve the yield of monosubstituted cyclopentadienyl yttrium precursors and simplify the purification steps to achieve large-scale synthesis.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] In a first aspect, the present invention discloses a method for preparing a monosubstituted cyclopentadienyl yttrium precursor, comprising the following steps:

[0009] S1. adding a monosubstituted cyclopentadiene to a solution of an alkali metal compound, and then heating the solution for reaction;

[0010] S2, adding the mixture of S1 dropwise to the solution containing yttrium halide to perform reflux reaction;

[0011] S3, filtering the mixture in S2 and removing the solvent by vacuum distillation;

[0012] The solvent in the solution of the alkali metal compound and the solution of the yttrium halide is an aromatic organic solvent.

[0013] Preferably, the structure of the monosubstituted cyclopentadiene in S1 is RCp, and R is a C1-C6 alkyl group or a silane group, preferably a C1-C3 alkyl group.

[0014] Preferably, the alkali metal compound in S1 includes NaH, LiH, KH, NaNH2, KNH2, MeLi, EtLi, n BuLi, i Pr2NLi(LDA), t BuONa, t One or more of BuOK; the yttrium halide described in S2 includes one or more of yttrium chloride, yttrium bromide, and yttrium iodide.

[0015] Preferably, the aromatic organic solvent is one or more of benzene, toluene, ethylbenzene, xylene, and trimethylbenzene, preferably toluene.

[0016] Preferably, the equivalent ratio of the monosubstituted cyclopentadiene to the alkali metal compound in S1 is 1:0.8-2.5.

[0017] Preferably, the heating reaction temperature in S1 is 60-90° C., and the reaction time is 8-24 h.

[0018] Preferably, the equivalent ratio of the monosubstituted cyclopentadiene and the yttrium halide described in S2 is 2-4.5:1.

[0019] Preferably, the heating reaction temperature in S2 is 100-130° C., and the reaction time is 10-24 h.

[0020] Preferably, when the monosubstituted cyclopentadiene is added in S1, the temperature of the solution of the alkali metal compound is controlled to be 20-50°C.

[0021] Preferably, when the mixture of S1 is added dropwise to S2, the temperature of the yttrium halide solution is controlled to be 20-50°C.

[0022] Based on this, a preferred method for preparing a monosubstituted cyclopentadienyl yttrium precursor is obtained, comprising the following steps:

[0023] S1. Adding monosubstituted cyclopentadiene to a toluene solution of an alkali metal compound, then heating to 75-85° C. and continuing the reaction for 8-24 hours;

[0024] S2, adding the mixture in S1 dropwise to the toluene solution of yttrium halide, and then performing reflux reaction at a reaction temperature of 110-125° C. for a reaction time of 10-24 h;

[0025] S3, filtering the mixture in S2 and removing the solvent by distillation under reduced pressure.

[0026] Beneficial effects of the present invention:

[0027] The present invention uses an aromatic organic solvent and a preparation method that precisely controls the reactant equivalents and reaction temperature, thereby increasing the product yield from 10% to 67.5%, significantly improving the reaction yield. Furthermore, purification requirements can be met by sublimation only twice, simplifying the purification steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The product of Example 1 of the present invention 1 H NMR spectrum.

[0029] Figure 2 The product of Example 2 of the present invention 1 H NMR spectrum.

[0030] Figure 3 The product of Example 3 of the present invention 1 H NMR spectrum.

[0031] Figure 1 The characterization data in is: 1 H NMR (C6D6): δ1.92 (3H, Cp-CH3), 5.85-5.93 (4H, Cp-H).

[0032] Figure 2 The characterization data in is: 1HNMR(C6D6): δ0.98(3H,Cp-C-CH3), 2.32(2H,Cp-CH2-C), 5.88-6.01(4H,Cp-H).

[0033] Figure 3 The characterization data in is: 1 HNMR(C6D6): δ1.04(6H,Cp-C-(CH3)2), 2.69(1H,Cp-CH-C2), 5.91-6.06(4H,Cp-H). DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments 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.

[0035] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0036] Example 1

[0037] This embodiment discloses a method for preparing a monosubstituted cyclopentadienyl yttrium precursor, comprising the following steps:

[0038] S1. Mix 78 g of NaH (3.25 mol) and 2.2 L of toluene to prepare a NaH toluene solution. Control the temperature to 35 ° C. Add 217 g of methylcyclopentadiene (2.71 mol) thereto. After completion, heat to 80 ° C., stir, and react for 15 h.

[0039] S2, 151g YCl3 (773mmol) and 730mL toluene were mixed to prepare a toluene solution of YCl3, the solution temperature was controlled at 28°C, the reaction solution of S1 was added dropwise to the toluene solution of YCl3, and the mixture was refluxed at 120°C for 15h;

[0040] S3. The filtrate was collected by filtration and the solvent was removed by distillation under reduced pressure at 90° C. to obtain 159.6 g of product with a yield of 65.7%.

[0041] The product was sublimed twice and tested to have a purity of 95.90%. 1 H NMR spectrum is attached Figure 1 .

[0042] Example 2

[0043] This embodiment discloses a method for preparing a monosubstituted cyclopentadienyl yttrium precursor, comprising the following steps:

[0044] S1. Mix 133 g of NaH (5.56 mol) and 3.5 L of toluene to prepare a NaH toluene solution. Control the temperature to 44 ° C. Add 216.7 g of ethylcyclopentadiene (2.30 mol) thereto. After completion, heat to 85 ° C., stir, and react for 8 h.

[0045] S2, 100.7g YCl3 (516mmol) and 1.5L toluene were mixed to prepare a toluene solution of YCl3, the solution temperature was controlled at 23°C, the reaction solution of S1 was added dropwise to the toluene solution of YCl3, and the mixture was refluxed at 130°C for 20h;

[0046] S3. The filtrate was collected by filtration and the solvent was removed by distillation under reduced pressure at 100° C. to obtain 124.0 g of product with a yield of 67.5%.

[0047] The product was sublimed twice and tested to have a purity of 98.72%. 1 H NMR spectrum is attached Figure 2 .

[0048] Example 3

[0049] This embodiment discloses a method for preparing a monosubstituted cyclopentadienyl yttrium precursor, comprising the following steps:

[0050] S1. Mix 34 g of NaH (1.42 mol) and 2.2 L of toluene to prepare a NaH toluene solution. Control the temperature to 45°C, add 180 g of isopropylcyclopentadiene (1.63 mol) thereto, and then heat to 75°C with stirring and react for 24 h.

[0051] S2, 151g YCl3 (773mmol) and 850mL toluene were mixed to prepare a toluene solution of YCl3, the solution temperature was controlled at 40°C, the reaction solution of S1 was added dropwise to the toluene solution of YCl3, and the mixture was refluxed at 110°C for 12h;

[0052] S3. The filtrate was collected by filtration and the solvent was removed by distillation under reduced pressure at 80° C. to obtain 179.0 g of product with a yield of 58.1%.

[0053] The purity of the product after sublimation twice is 98.96%. 1 H NMR spectrum is attached Figure 3 .

[0054] Comparative Example 1

[0055] The difference from Example 1 is that toluene is replaced by tetrahydrofuran, and other conditions remain the same. Finally, 20 g of product is obtained with a yield of 8.2%.

[0056] The purity of the product was 87.34% after two sublimations and 95.26% after four sublimations.

[0057] Comparative Example 2

[0058] The difference from Example 1 is that toluene is replaced by n-hexane, and other conditions remain the same. Finally, 24.4 g of product is obtained with a yield of 10%.

[0059] The purity of the product was 89.78% after two sublimations and 96.33% after four sublimations.

[0060] Comparative Example 3

[0061] The difference from Example 1 is that the temperature of the toluene solution of YCl3 in S2 is controlled to 5°C, and other conditions remain the same, ultimately obtaining 87.1g of product with a yield of 35.8%.

[0062] The purity of the product after sublimation twice was 92.67%.

[0063] Comparative Example 4

[0064] The difference from Example 1 is that the heating temperature after adding methylcyclopentadiene in S1 is changed to 55° C., and other conditions remain the same. Finally, 82.4 g of product is obtained with a yield of 33.9%.

[0065] The purity of the product after sublimation twice was 93.33%.

[0066] Comparative Example 5

[0067] The difference from Example 1 is that the reflux reaction temperature described in S2 is changed to 140° C., and other conditions remain the same. Finally, 100 g of product is obtained with a yield of 41.2%.

[0068] The purity of the product after sublimation twice was 94.35%.

[0069] Comparative Example 6

[0070] The difference from Example 1 is that the amount of methylcyclopentadiene is changed to 492 g, that is, the equivalent ratio of methylcyclopentadiene to YCl3 is 5.2:1. Other conditions remain the same, and 127.1 g of product is finally obtained, with a yield of 33%.

[0071] The purity of the product after sublimation twice was 94.77%.

[0072] Comparative Example 7

[0073] The difference from Example 1 is that it includes the following steps:

[0074] S1, 78g NaH (3.25mol), 151g YCl3 (773mmol) and 2.93L toluene were mixed, and the temperature during mixing was controlled to be 20-40°C. 217g methylcyclopentadiene (2.71mol) was added thereto, and after completion, the temperature was raised to 80°C, heated with stirring, and reacted for 15h, and then raised to 120°C and refluxed for 15h;

[0075] S2. The filtrate was collected by filtration and the solvent was removed by distillation under reduced pressure at 90° C. to obtain 71.5 g of product with a yield of 29.4%.

[0076] The purity of the product after sublimation twice was 95.39%.

[0077] The sublimation operations described in Examples 1-3 and Comparative Examples 1-7 are specifically as follows:

[0078] The crude product obtained after desolvation was placed in a sublimator and heated to 220°C using a gradient heating method (the initial temperature was set at 160°C, and then the sublimation condition was observed and increased by 10°C per hour), and then continued to heat and sublimate for 12 hours.

[0079] The yield and purity of the monosubstituted cyclopentadienyl yttrium prepared in Examples 1-3 and Comparative Examples 1-7 were calculated as follows:

[0080] Yield = actual mass of product / theoretical mass × 100%.

[0081] Purity test using 1 H NMR;

[0082] Purity = (1-total area of ​​minor impurity peaks / total integral of target compound) × 100%.

[0083] Table 2 is a table of process parameters for the above embodiments and comparative examples.

[0084] Table 2

[0085]

[0086]

[0087] Analysis of the data in Table 2 shows that from Examples 1-3, the product yields in this process all reached over 58%, and after two sublimation purifications, the product purity reached over 95%.

[0088] The present invention adopts an aromatic organic solvent such as toluene and a preparation method that precisely controls the reactant equivalents and reaction temperature, which has a significant effect on improving industrial synthesis yield and simplifying purification steps. It can improve the yield and simplify the purification steps, and realize the efficient and large-scale preparation of mono-substituted cyclopentadienyl yttrium, thereby promoting its wide application in fields such as semiconductor devices.

[0089] 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.

[0090] 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 preparing a monosubstituted cyclopentadienyl yttrium precursor, characterized in that: The steps include: S1. adding a monosubstituted cyclopentadiene to a solution of an alkali metal compound, and then heating the solution for reaction; S2, adding the mixture of S1 dropwise to the solution containing yttrium halide to perform reflux reaction; S3, filtering the mixture in S2 and removing the solvent by vacuum distillation; The solvent in the solution of the alkali metal compound and the solution of the yttrium halide is an aromatic organic solvent.

2. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The structure of the monosubstituted cyclopentadiene in S1 is RCp, and R is a C1-C6 alkyl group or a silane group, preferably a C1-C3 alkyl group.

3. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The alkali metal compound in S1 includes NaH, LiH, KH, NaNH2, KNH2, MeLi, EtLi, n BuLi, i Pr2NLi, t BuONa, t One or more of BuOK; the yttrium halide in S2 includes one or more of yttrium chloride, yttrium bromide, and yttrium iodide.

4. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The aromatic organic solvent is one or more of benzene, toluene, ethylbenzene, xylene, and trimethylbenzene, preferably toluene.

5. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The equivalent ratio of the monosubstituted cyclopentadiene and the alkali metal compound in S1 is 1:0.8-2.

5.

6. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The heating reaction temperature in S1 is 60-90° C., and the reaction time is 8-24 h.

7. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The equivalent ratio of the monosubstituted cyclopentadiene and the yttrium halide described in S2 is 2-4.5:

1.

8. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: The heating reaction temperature in S2 is 100-130° C., and the reaction time is 10-24 h.

9. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: When adding monosubstituted cyclopentadiene to S1, the solution temperature of the alkali metal compound is controlled to be 20-50°C.

10. The method for preparing a monosubstituted cyclopentadienyl yttrium precursor according to claim 1, wherein: When the mixture of S1 is added dropwise to S2, the temperature of the yttrium halide solution is controlled to be 20-50°C.

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