Method for preparing molybdenum dichloride dioxide

Abstract

The present invention relates to a method for preparing molybdenum dichloride dioxide. The method for preparing molybdenum dichloride dioxide of the present invention enables obtaining of solvent-free molybdenum dichloride dioxide in a high yield without using dangerous chlorine gas and a high reaction temperature, and thus is safe and has the advantages of enabling not only small-scale production but also mass production, thereby being an industrially very useful and efficient method.

Description

Method for producing molybdenum dioxydichloride

[0001] The present invention relates to a method for producing molybdenum dioxydichloride (MoO2Cl2). More specifically, it relates to a method for synthesizing molybdenum dioxydichloride in an anhydrous and solvent-free form.

[0002]

[0003] Molybdenum dioxydichloride (MoO2Cl2) is a well-known inorganic compound of molybdenum.

[0004]

[0005] Recently, the above molybdenum dioxide dichloride (MoO2Cl2) has been attracting attention as a precursor for deposition of metal molybdenum films using vacuum deposition technology (CVD, or ALD) in the semiconductor industry.

[0006] Molybdenum films deposited using the above molybdenum dioxydichloride (MoO2Cl2) generally exhibit better performance than those deposited using organometallic molybdenum precursors. This is because molybdenum dioxydichloride (MoO2Cl2) does not contain nitrogen and carbon atoms, resulting in a higher purity of the final film.

[0007]

[0008] Meanwhile, the two most common methods for synthesizing the above molybdenum dioxydichloride (MoO2Cl2) are to chlorinate molybdenum dioxide (MoO2) and molybdenum trioxide (MoO3), as shown in the following chemical formulas 1 and 2.

[0009]

[0010] MoO2+ Cl2→ MoO2Cl2 (chemical formula 1)

[0011] 2 MoO3+ 2 Cl2→ 2 MoO2Cl2+ O2 (chemical formula 2)

[0012]

[0013] The two methods of the above chemical formulas 1 and 2 are methods in which an excess of chlorine gas is passed through the respective solid oxide layers of chemical formulas 1 and 2, i.e., molybdenum dioxide (MoO2) and molybdenum trioxide (MoO3), at high temperatures. At this time, the passage of chlorine gas through the molybdenum dioxide layer is performed at 200°C or higher, and through the molybdenum trioxide layer is performed at 900°C or higher.

[0014] Molybdenum dioxide dichloride (MoO2Cl2) produced by passing chlorine gas in the above chemical formulas 1 and 2 is separated and obtained by sublimation.

[0015]

[0016] However, the two manufacturing methods of the above chemical formulas 1 and 2,

[0017] i) There is a problem of having to remove the excess chlorine gas used in the manufacturing method, and also

[0018] ii) Molybdenum dioxydichloride (MoO2Cl2) obtained by sublimation is a very light and fluffy solid, which has the problem of taking up space in the obtained product and having a high possibility of blocking the exhaust line.

[0019]

[0020] To solve the above problems, another method for manufacturing molybdenum dioxydichloride (MoO2Cl2) is proposed, as shown in the following chemical formulas 3-1 and 3-2.

[0021]

[0022] Na2MoO4+ 4Me3SiCl(in dme) → MoO2Cl2(dme) + 2NaCl + 2(Me3Si)2O (Chemical Formula 3-1)

[0023] (NH4)2Mo2O7+ 6Me3SiCl(in dme) → 2MoO2Cl2(dme) + 2 NH4Cl + 3(Me3Si)2O (Chemical Formula 3-2)

[0024]

[0025] The manufacturing methods of the above chemical formulas 3-1 and 3-2 are to manufacture a molybdenum dioxydichloride solvated adduct (MoO2Cl2(dme)), which is a 1,2-dimethoxyethane(dme) solvated form of molybdenum dioxydichloride, by reacting sodium molybdenum dioxydichloride (Na2MoO4) and ammonium molybdate ((NH4)2Mo2O7) with chlorotrimethylsilane dimethoxyethane (Me3SiCl(in dme)), respectively.

[0026] Both of the above two methods, Chemical Formula 3-1 and Chemical Formula 3-2, can obtain pure molybdenum dioxydichloride dimethoxyethane (MoO2Cl2(dme)) in high yield, and this product is widely used as an intermediate for the synthesis of many molybdenum compounds.

[0027] Although the above solvating adducts are known to be capable of removing the solvent using common techniques (e.g., heating under vacuum), the molybdenum dioxydichloride dimethoxyethane (MoO2Cl2(dme)) decomposes when heated above its melting point, making it impossible to obtain pure solvent-free molybdenum dioxydichloride.

[0028]

[0029] Another molybdenum dioxydichloride (MoO2Cl2) is prepared by a method disclosed in the following chemical formula 4.

[0030]

[0031] MoOCl4+ (Me3Si)2O → MoO2Cl2+ 2 Me3SiCl (chemical formula 4)

[0032]

[0033] Molybdenum oxytetrachloride (MoOCl4) in its perchlorinated form is converted into the desired molybdenum dioxydichloride (MoO2Cl2) in high yield through reaction with hexamethyldisiloxane. However, molybdenum oxytetrachloride (MoOCl4), the starting material in the chemical formula 4, is not readily available.

[0034]

[0035] As described above, there are many problems in the production of molybdenum dioxydichloride (MoO2Cl2), and there is an urgent need to develop a new method for producing molybdenum dioxydichloride (MoO2Cl2) to improve these problems.

[0036]

[0037] The present invention seeks to provide a method for producing molybdenum dioxydichloride (MoO2Cl2) that overcomes the disadvantages of the conventionally known production methods while providing various advantages.

[0038] The present invention may also aim to achieve other purposes that can be easily derived by a person skilled in the art from the above-mentioned clear purpose and the overall description of the present specification.

[0039]

[0040] The method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention for the above purpose can be expressed as shown in the following chemical formula 5.

[0041]

[0042] MoO3+ SOCl2→ MoO2Cl2+ 2 SO2 (chemical formula 5)

[0043]

[0044] Specifically, the method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention is as follows:

[0045] i) a step of mixing anhydrous molybdenum trioxide and thionyl chloride in a solvent under an inert gas to produce a mixture (first step of producing a mixture);

[0046] ii) a step of raising the temperature of the above-mentioned mixture under an inert gas and stirring under reflux to produce a precipitated solid product (second step of producing a solid product); and

[0047] iii) a step of separating and purifying molybdenum dioxydichloride (MoO2Cl2) from the solid product produced above (the third step of separating and purifying molybdenum dioxydichloride (MoO2Cl2));

[0048]

[0049] Looking at each of the above steps,

[0050] In the first step of producing the above mixture, the usage ratio (in moles) of molybdenum trioxide:thionyl chloride may be less than 1:0.5 to 1:2.0.

[0051] The solvent in the first step of producing the above mixture must be a non-coordinating solvent that should not react or coordinate with the product molybdenum dioxydichloride (MoO2Cl2).

[0052] Specifically, the non-coordinating solvent may be an aliphatic or aromatic solvent having 2 or more carbon atoms and containing a halogen element.

[0053] The solvent may have a boiling point of 50°C to 200°C.

[0054] The inert gas in the reaction vessel in the first step of producing the mixture and the second step of producing the solid product may be at least one gas selected from the group consisting of nitrogen (N2), argon (Ar), and helium (He).

[0055]

[0056] In the second step of producing the above solid product, the elevated temperature for reflux stirring may be from 50°C to 200°C.

[0057]

[0058] In the third step of separation and purification of the above molybdenum dioxydichloride (MoO2Cl2), the separation is a step of filtering the produced solid product, washing it with the solvent of the first step of producing the mixture, and drying it in a vacuum to obtain molybdenum dioxydichloride (MoO2Cl2).

[0059] The above purification is performed by sublimating molybdenum dioxydichloride (MoO2Cl2) obtained by drying.

[0060]

[0061] As described above, the method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention has the advantage of being able to avoid dangerous chlorine gas and high reaction temperature, unlike conventionally known techniques, and of being able to obtain molybdenum dioxydichloride (MoO2Cl2) without a solvent in a high yield.

[0062] In addition, the method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention is safe because it does not use hazardous chlorine gas and high reaction temperature, and thus has the advantage of being capable of mass production as well as small-scale production.

[0063] Furthermore, there is an economic advantage in the production of molybdenum dioxydichloride (MoO2Cl2) because it uses molybdenum trioxide (MoO3) and thionyl chloride (SOCl2), which are readily available and inexpensive, as reactants.

[0064]

[0065] FIG. 1 is a graph showing the results of TGA (Thermogravimetric Analyzer) analysis for purified molybdenum dioxydichloride (MoO2Cl2) obtained according to Example 1 of the present invention (Example 1) and molybdenum dioxydichloride (MoO2Cl2) purchased from Sigma Aldrich (Reference).

[0066] Figure 2 is an analysis result of ICP-MS (Inductively Coupled Plasma Mass Spectrometer) for sublimated molybdenum dioxydichloride (MoO2Cl2) according to the present invention.

[0067]

[0068] Hereinafter, the present invention will be described in detail.

[0069] However, the following merely exemplifies and details specific embodiments. The present invention is capable of various modifications and takes numerous forms, and is therefore not limited to the specific embodiments exemplified. It should be understood that the present invention encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0070] Additionally, the following description describes many specific details, such as specific components, etc., which are provided only to help a more general understanding of the present invention, and it will be apparent to one skilled in the art that the present invention can be practiced without these specific details.

[0071] In addition, when describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description is omitted.

[0072]

[0073] Furthermore, the terminology used in this application is solely for the purpose of describing specific embodiments and is not intended to limit the present invention. Unless otherwise defined, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0074] In this application, singular expressions also include plural expressions unless the context clearly indicates otherwise.

[0075] While the present application may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another.

[0076] In this application, terms such as “include,” “contain,” or “have” are intended to indicate the presence of features, components (or constituents) described in the specification, but do not mean that one or more other features or components do not exist or cannot be added.

[0077]

[0078] Hereinafter, the present invention will be described in detail.

[0079]

[0080] The method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention can be expressed as shown in the following chemical formula 5.

[0081]

[0082] MoO3+ SOCl2→ MoO2Cl2+ SO2 (chemical formula 5)

[0083]

[0084] Specifically, the method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention is as follows:

[0085] i) a step of mixing anhydrous molybdenum trioxide and thionyl chloride in a solvent under an inert gas to produce a mixture ('first step of producing a mixture');

[0086] ii) a step of raising the temperature of the above-mentioned mixture under an inert gas and stirring it under reflux to produce a precipitated solid product ('second step of producing a solid product'); and

[0087] iii) a step of separating and purifying molybdenum dioxydichloride (MoO2Cl2) from the solid product produced above ('the third step of separating and purifying molybdenum dioxydichloride (MoO2Cl2)');

[0088]

[0089] Looking at each of the above steps in detail,

[0090] In the first step of producing the above mixture, the usage ratio (in moles) of molybdenum trioxide:thionyl chloride may be from 1:0.5 to less than 1:2.0, preferably from 1:0.8 to 1:1.5, and more preferably 1:1.

[0091] The solvent in the first step of producing the above mixture must be a non-coordinating solvent that should not react or coordinate with the product molybdenum dioxydichloride (MoO2Cl2).

[0092] Specifically, the non-coordinating solvent may be an aliphatic or aromatic solvent having 2 or more carbon atoms and containing a halogen element.

[0093] The solvent may have a boiling point of 50°C to 200°C, preferably a boiling point of 70°C to 120°C, and most preferably a boiling point of 80°C to 100°C.

[0094] Specifically, the solvent may be at least one selected from the group consisting of tetrachloromethane (CCl4), 1,2-dichloroethane (C2H4Cl2), 1,1,1-trichloroethane, 1,1,2-trichloroethane (C2H3Cl3), and chlorobenzene (C6H5Cl).

[0095]

[0096] The inert gas in the reaction vessel in the first step of producing the mixture and the second step of producing the solid product may be at least one gas selected from the group consisting of nitrogen (N2), argon (Ar), and helium (He).

[0097]

[0098] In the second step of producing the above solid product, the elevated temperature for reflux stirring may be 50°C to 200°C, preferably 70°C to 120°C, and more preferably 80°C to 100°C. The reaction time for the reflux stirring may be 16 hours to 72 hours.

[0099]

[0100] In the third step of separation and purification of the above molybdenum dioxydichloride (MoO2Cl2), the separation is a step of filtering the produced solid product, washing it with the solvent of the first step of producing the mixture, and drying it in a vacuum to obtain molybdenum dioxydichloride (MoO2Cl2).

[0101] The above purification is performed by sublimating molybdenum dioxydichloride (MoO2Cl2) obtained by drying.

[0102]

[0103] The present invention is described in more detail through the examples described below.

[0104]

[0105] <Example 1>

[0106] 100 g (0.68 mol) of anhydrous molybdenum trioxide was added to a 1 L four-necked flask equipped with a magnetic stirring bar under an inert gas atmosphere. 500 ml of anhydrous 1,2-dichloroethane was then added, followed by slow addition of 82 g (0.68 mol) of thionyl chloride at room temperature (MoO3:SOCl2=1:1 molar ratio).

[0107] The resulting mixture was stirred using a magnetic stirrer to form a white suspension. The suspension was heated and refluxed under an inert gas atmosphere for 24 hours. During this time, a visible change in precipitation occurred.

[0108] The resulting yellow-brown mixture was filtered to obtain a yellow-brown solid product, which was washed with anhydrous 1,2-dichloroethane and dried under vacuum at room temperature to obtain 127 g of molybdenum dioxydichloride (MoO2Cl2) (yield 97%).

[0109] The above-obtained product (MoO2Cl2) was purified by sublimation (90°C / 180 mtorr) to obtain 121 g of a pale yellow solid product (yield 87%).

[0110] The obtained yellow solid product (MoO2Cl2) was analyzed using TGA analysis, and the TGA analysis results showed the same analysis results as molybdenum dioxydichloride (MoO2Cl2, CAS Number 13637-68-8) purchased from Sigma aldrich, and these results indicate that the compound manufactured by the method for manufacturing molybdenum dioxydichloride of the present invention is molybdenum dioxydichloride (see Fig. 1).

[0111]

[0112] The above TGA analysis was performed using a Mettler Toledo TGA / DSC 3+, and the test material was heated to 500°C at a rate of 10°C / min.

[0113] In addition, the obtained yellow solid product (MoO2Cl2) was shown to have a purity of 99.999% or more through ICP-MS analysis (Figure 2).

[0114]

[0115] The above ICP-MS analysis was performed using Thermo Scientific XSeries 2.

[0116]

[0117] <Example 2>

[0118] Except that 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous 1,2-dichloroethane, and 7.4 g (0.063 mol) of thionyl chloride were used (MoO3:SOCl2=1:0.9 molar ratio), the same method as in Example 1 was followed to obtain 12 g of molybdenum dioxydichloride (MoO2Cl2) (yield 87%). The obtained molybdenum dioxydichloride (MoO2Cl2) was purified by sublimation in the same manner as in Example 1 to obtain 11 g of a pale yellow solid product (MoO2Cl2) (yield 79%).

[0119]

[0120] <Example 3>

[0121] Except that 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous 1,2-dichloroethane, and 9.9 g (0.083 mol) of thionyl chloride were used (MoO3:SOCl2=1:1.2 molar ratio), the same method as in Example 1 was followed to obtain 11 g of molybdenum dioxydichloride (MoO2Cl2) (yield 82%). The obtained molybdenum dioxydichloride (MoO2Cl2) was purified by sublimation in the same manner as in Example 1 to obtain 9 g of a pale yellow solid product (MoO2Cl2) (yield 69%).

[0122]

[0123] <Example 4>

[0124] Synthesis was performed using the same method as in Example 1, using 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous 1,2-dichloroethane, and 8.2 g (0.069 mol) of thionyl chloride, and stirring under reflux for 16 hours. (MoO3:SOCl2=1:1) 10 g of molybdenum dioxydichloride was obtained with a yield of 72% before purification, and 9 g of a pale yellow solid product was obtained with a yield of 68% after purification.

[0125]

[0126] <Example 5>

[0127] Synthesis was performed using the same method as in Example 1, using 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous 1,2-dichloroethane, and 8.2 g (0.069 mol) of thionyl chloride, and stirring was performed at 60°C for 24 hours. (MoO3:SOCl2=1:1) 10 g of molybdenum dioxydichloride was obtained with a yield of 76% before purification, and 7 g of a pale yellow solid product was obtained with a yield of 49% after purification.

[0128]

[0129] <Comparative Example 1>

[0130] Synthesis was performed using the same method as in Example 1, and 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous heptane, and 8.2 g (0.069 mol) of thionyl chloride were used, and the mixture was stirred under reflux for 24 hours, but the desired molybdenum dioxydichloride could not be obtained.

[0131]

[0132] <Comparative Example 2>

[0133] Synthesis was performed using the same method as in Example 1, and 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous dichloromethane, and 8.2 g (0.069 mol) of thionyl chloride were used, and refluxing was performed for 24 hours, but the desired molybdenum dioxydichloride could not be obtained.

[0134]

[0135] <Comparative Example 3>

[0136] Synthesis was performed using the same method as in Example 1, and 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous toluene, and 8.2 g (0.069 mol) of thionyl chloride were used, and the mixture was stirred under reflux for 24 hours, but the desired molybdenum dioxydichloride could not be obtained.

[0137]

[0138] <Comparative Example 4>

[0139] Synthesis was performed using the same method as in Example 1, and 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous 1,2-dichloroethane, and 16.4 g (0.136 mol) of thionyl chloride (MoO3:SOCl2=1:2 molar ratio) were used, and refluxing and stirring was performed for 24 hours, but the desired molybdenum dioxydichloride could not be obtained.

[0140]

[0141] While the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above, and those skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the above embodiments, but should be determined not only by the claims set forth below but also by equivalents thereof.

[0142] As described above, when using the method for producing molybdenum dioxydichloride (MoO2Cl2) of the present invention, it is safe because it does not use chlorine gas and a high reaction temperature, and thus it is possible to produce not only small-scale production but also mass production, making it very useful industrially.

Claims

1. A method for manufacturing molybdenum dioxydichloride, i) a step of mixing anhydrous molybdenum trioxide and thionyl chloride in a non-coordinating solvent under an inert gas to produce a mixture ('first step of producing a mixture'); ii) a step of raising the temperature of the above-mentioned mixture under an inert gas and stirring it under reflux to produce a precipitated solid product ('second step of producing a solid product'); and iii) a step of separating and purifying molybdenum dioxydichloride (MoO2Cl2) from the solid product produced above ('the third step of separating and purifying molybdenum dioxydichloride (MoO2Cl2)'); A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the solvent is an aliphatic and aromatic solvent containing a halogen element having a boiling point of 50°C to 200°C.

2. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the non-coordinating solvent is at least one non-coordinating solvent selected from the group consisting of tetrachloromethane (CCl4), 1,2-dichloroethane (C2H4Cl2), 1,1,1-trichloroethane, 1,1,2-trichloroethane (C2H3Cl3), and chlorobenzene (C6H5Cl).

3. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the ratio (in moles) of molybdenum trioxide:thionyl chloride used in the first step of producing the mixture is less than 1:0.5 to 1:2.

0.

4. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the ratio (molar) of molybdenum trioxide:thionyl chloride used in the first step of producing the above mixture is 1:0.8 to 1:1.

5.

5. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the ratio (molar) of molybdenum trioxide:thionyl chloride used in the first step of producing the above mixture is 1:

1.

6. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the reflux stirring in the second step of producing the above solid product is performed at a temperature of 50°C to 200°C.

7. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the reflux stirring in the second step of producing the above solid product is performed at a temperature of 70°C to 120°C.

8. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the reflux stirring in the second step of producing the above solid product is performed at a temperature of 80°C to 100°C.

9. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the inert gas in the reaction vessel in the first step of producing the mixture and the second step of producing the solid product is at least one gas selected from the group consisting of nitrogen (N2), argon (Ar) and helium (He).

10. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the reaction time of the above reflux stirring is 16 to 72 hours.

11. In paragraph 1, A method for producing molybdenum dioxydichloride (MoO2Cl2), characterized in that the third step of purification of separation and purification of molybdenum dioxydichloride (MoO2Cl2) is a sublimation method.

Images