Method for producing molybdenum dioxide dichloride

Abstract

The present invention relates to a method for producing molybdenum dioxide dichloride. The method for producing molybdenum dioxide dichloride of the present invention can produce molybdenum dioxide dichloride in high yield and without using hazardous chlorine gas or high reaction temperatures, and therefore has the advantages of being safe and being capable of being produced in both small-scale and large-scale production, making it an industrially very useful and efficient method.

Description

[Technical Field]

[0001] The present invention relates to a method for producing molybdenum dioxide dichloride (MoO2Cl2), more particularly to a method for synthesizing molybdenum dioxide dichloride in an anhydrous, solvent-free form. [Background technology]

[0002] Molybdenum dioxide dichloride (MoO2Cl2) is a well-known inorganic molybdenum compound.

[0003] Recently, molybdenum dioxide dichloride (MoO2Cl2) has attracted attention in the semiconductor industry as a precursor for the deposition of metallic molybdenum films via vacuum deposition techniques (CVD or ALD).

[0004] Molybdenum films deposited using molybdenum dioxide dichloride (MoO2Cl2) generally exhibit better performance than those deposited using organometallic molybdenum precursors because the purity of the final film is higher since molybdenum dioxide dichloride (MoO2Cl2) does not contain nitrogen or carbon atoms.

[0005] The two most common methods for synthesizing molybdenum dioxide dichloride (MoO2Cl2) are to chlorinate molybdenum dioxide (MoO2) and molybdenum trioxide (MoO3), as shown in the following chemical formulas 1 and 2.

[0006] MoO2+Cl2→MoO2Cl2 (chemical formula 1)

[0007] 2MoO3+2Cl2→2MoO2Cl2+O2 (chemical formula 2)

[0008] The two methods of Chemical Formula 1 and Chemical Formula 2 involve passing an excess amount of chlorine gas through the solid oxide layers of Chemical Formula 1 and Chemical Formula 2, i.e., molybdenum dioxide (MoO2) and molybdenum trioxide (MoO3), at high temperatures. In this case, the passage of chlorine gas proceeds at 200°C or higher for the molybdenum dioxide layer and 900°C or higher for the molybdenum trioxide layer.

[0009] In the above formulas 1 and 2, molybdenum dioxide dichloride (MoO2Cl2) produced by passing chlorine gas is separated and obtained by sublimation.

[0010] However, the two production methods of Chemical Formula 1 and Chemical Formula 2 are as follows: (i) There is a problem that the excess chlorine gas used in the manufacturing process must be removed. (ii) Molybdenum dioxide dichloride (MoO2Cl2) separated and obtained by sublimation sublimates into a very light and fluffy solid, which occupies the collection space and has a high possibility of clogging the exhaust line.

[0011] To solve the above problems, other methods for producing molybdenum dioxide dichloride (MoO2Cl2) have been proposed, as shown in the following formulas 3-1 and 3-2.

[0012] Na2MoO4+4Me3SiCl(in dme)→MoO2Cl2(dme)+2NaCl+2(Me3Si)2O (chemical formula 3-1)

[0013] (NH4)2Mo2O7+6Me3SiCl(in dme)→2MoO2Cl2(dme)+2NH4Cl+3(Me3Si)2O (chemical formula 3-2)

[0014] The preparation methods of the compounds represented by formulas 3-1 and 3-2 are to react sodium molybdenum dioxide dichloride (NaMoO) and ammonium molybdate ((NH)MoO) with chlorotrimethylsilane dimethoxyethane (MeSiCl(in dme)), respectively, to prepare a solvated molybdenum dioxide dichloride adduct (MoOCl(dme)), which is a solvated form of molybdenum dioxide dichloride in 1,2-dimethoxyethane (dme).

[0015] Both of the above two methods, Chemical Formula 3-1 and Chemical Formula 3-2, can produce 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.

[0016] It is known that the solvent can be removed from the solvated adduct using common techniques (e.g., heating under vacuum). However, when the molybdenum dioxide dichloride dimethoxyethane (MoOCl(dme)) is heated above its melting point, the molybdenum dioxide dichloride is decomposed, making it impossible to obtain pure, solvent-free molybdenum dioxide dichloride.

[0017] Yet another method for producing molybdenum dioxide dichloride (MoO2Cl2) is disclosed in Chemical Scheme 4 below.

[0018] MoOCl4+(Me3Si)2O→MoO2Cl2+2Me3SiCl (chemical formula 4)

[0019] Perchlorinated molybdenum oxytetrachloride (MoOCl4) can be converted to the preferred molybdenum dioxide dichloride (MoO2Cl2) in high yield through reaction with hexamethyldisiloxane. However, the starting material in Formula 4, molybdenum oxytetrachloride (MoOCl4), is not readily available.

[0020] As described above, the production of molybdenum dioxide dichloride (MoO2Cl2) has many problems, and there is an urgent need to develop a new method for producing molybdenum dioxide dichloride (MoO2Cl2) that will improve these problems. Summary of the Invention [Problem to be solved by the invention]

[0021] The present invention seeks to provide a method for preparing molybdenum dioxide dichloride (MoO2Cl2) that offers various advantages while overcoming the drawbacks of the previously known preparation methods.

[0022] The present invention also aims to achieve the above-mentioned clear objects as well as other objects that can be easily derived by a person of ordinary skill in the art from the general teachings of this specification. [Means for solving the problem]

[0023] The method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention for the above purpose can be expressed as in Chemical Formula 5 below.

[0024] MoO3+SOCl2→MoO2Cl2+2SO2 (chemical formula 5)

[0025] Specifically, the method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention includes the following steps: (i) mixing anhydrous molybdenum trioxide and thionyl chloride in a solvent under an inert gas to form a mixture (first step of mixture formation); (ii) refluxing the resulting mixture under an inert atmosphere at elevated temperature to produce a precipitated solid product (a second step of producing a solid product); and (iii) separating and purifying molybdenum dioxide dichloride (MoO2Cl2) from the solid product (third step of separating and purifying molybdenum dioxide dichloride (MoO2Cl2));

[0026] Looking at each of the above stages, In the first stage of producing the mixture, the ratio (molar) of the amounts of molybdenum trioxide and thionyl chloride used may be 1:0.5 to less than 1:2.0.

[0027] The solvent in the first step of forming the mixture must be a non-coordinating solvent that must not react or coordinate with the product molybdenum dioxide dichloride (MoO2Cl2).

[0028] Specifically, the non-coordinating solvent may be an aliphatic or aromatic solvent containing a halogen element and having two or more carbon atoms.

[0029] The solvent may have a boiling point of 50°C to 200°C.

[0030] The inert gas in the reaction vessels for the first stage of producing the mixture and the second stage of producing the solid product may be one or more gases selected from the group consisting of nitrogen (N), argon (Ar), and helium (He).

[0031] In the second stage of producing the solid product, the elevated temperature for reflux stirring may be 50°C to 200°C.

[0032] In the third step of separating and purifying the molybdenum dioxide dichloride (MoO2Cl2), the separation is performed by filtering the solid product, washing it with the solvent used in the first step of the mixture production, and drying it in a vacuum to obtain molybdenum dioxide dichloride (MoO2Cl2).

[0033] The purification is carried out by sublimating the molybdenum dioxide dichloride (MoO2Cl2) obtained by drying. [Effects of the Invention]

[0034] As described above, the method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention has the advantage that it can avoid the use of hazardous chlorine gas and high reaction temperatures, and can produce molybdenum dioxide dichloride (MoO2Cl2) in high yield without using a solvent, unlike conventional known techniques.

[0035] In addition, the method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention does not use hazardous chlorine gas or high reaction temperatures, so it is safe and has the advantage of being suitable for both small-scale and mass production.

[0036] Furthermore, since molybdenum trioxide (MoO3) and thionyl chloride (SOCl2), which are easily available and inexpensive, are used as reactants, the method has the advantage of being economical in producing molybdenum dioxide dichloride (MoO2Cl2). [Brief explanation of the drawings]

[0037] [Figure 1] 1 is a graph showing the results of a thermogravimetric analyzer (TGA) analysis of purified molybdenum dioxide dichloride (MoO2Cl2) obtained in Example 1 of the present invention (Example 1) and molybdenum dioxide dichloride (MoO2Cl2) (Reference) purchased from Sigma-Aldrich. [Figure 2] 1 shows the results of an ICP-MS (Inductively Coupled Plasma Mass Spectrometer) analysis of sublimed molybdenum dioxide dichloride (MoO2Cl2) according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0038] The present invention will be described in detail below.

[0039] However, the following description merely illustrates and describes in detail specific embodiments, and the present invention can be modified in various ways and can have various forms, so the present invention is not limited to the specific embodiments illustrated. It should be understood that the present invention includes all modifications, equivalents, and alternatives that fall within the spirit and technical scope of the present invention.

[0040] Furthermore, in the following description, many specific details such as specific components are described, but this is provided merely to facilitate a more general understanding of the present invention, and it will be obvious to those skilled in the art that the present invention can be practiced without such specific details.

[0041] Furthermore, when describing the present invention, if it is determined that a detailed description of related well-known functions or configurations may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

[0042] Furthermore, the terms used in this application are merely used to describe specific embodiments and are not intended to limit the present invention. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention belongs. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined in this application.

[0043] In this application, the singular expression also includes the plural expression unless the context clearly indicates otherwise.

[0044] In this application, the terms may be used to describe various components, but the components are not limited by the terms, and are used only to distinguish one component from another.

[0045] In this application, the terms "comprise," "contain," or "have" refer to the presence of a feature, component (or constituent), etc. described in the specification, but do not mean that one or more other features, components, etc. are not present or cannot be added.

[0046] The present invention will be specifically described in detail below.

[0047] The method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention can be expressed as the following Chemical Formula 5.

[0048] MoO3+SOCl2→MoO2Cl2+SO2 (chemical formula 5)

[0049] Specifically, the method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention includes the following steps: (i) mixing anhydrous molybdenum trioxide and thionyl chloride in a solvent under an inert gas to form a mixture ("first step of forming a mixture"); (ii) refluxing the resulting mixture under an inert atmosphere at elevated temperature to produce a precipitated solid product ("second stage of solid product production"); and (iii) separating and purifying molybdenum dioxide dichloride (MoO2Cl2) from the resulting solid product ("third step of separating and purifying molybdenum dioxide dichloride (MoO2Cl2)");

[0050] Specifically, looking at each of the above stages, The ratio (molar) of molybdenum trioxide to thionyl chloride used in the first stage of producing the mixture 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.

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

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

[0053] 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.

[0054] Specifically, the solvent may be one or more selected from the group consisting of tetrachloromethane (CCl4), 1,2-dichloroethane (C2H4Cl2), 1,1,1-trichloroethane, 1,1,2-trichloroethane (C2H3Cl3), and chlorobenzene (C6H5Cl).

[0055] The inert gas in the reaction vessels for the first stage of producing the mixture and the second stage of producing the solid product may be one or more gases selected from the group consisting of nitrogen (N), argon (Ar), and helium (He).

[0056] In the second stage of producing the 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 reflux stirring may be 16 hours to 72 hours.

[0057] In the third step of separating and purifying the molybdenum dioxide dichloride (MoO2Cl2), the separation is performed by filtering the solid product, washing it with the solvent used in the first step of the mixture production, and drying it in a vacuum to obtain molybdenum dioxide dichloride (MoO2Cl2).

[0058] The purification is carried out by sublimating the molybdenum dioxide dichloride (MoO2Cl2) obtained by drying. DETAILED DESCRIPTION OF THE INVENTION

[0059] The present invention will now be described in more detail with reference to the following examples.

[0060] Example 1 A 1 L four-neck flask equipped with a magnetic stir bar was charged with 100 g (0.68 mol) of anhydrous molybdenum trioxide under an inert atmosphere. 500 mL of anhydrous 1,2-dichloroethane was then added, followed by 82 g (0.68 mol) of thionyl chloride (MoO3:SOCl2 = 1:1 molar ratio) at room temperature.

[0061] The resulting mixture was stirred using a magnetic stirrer to produce a white suspension, which was then refluxed under an inert gas atmosphere at elevated temperature for 24 hours, at which time a visible change in precipitate formation occurred.

[0062] The resulting yellow-brown mixture was filtered to obtain a yellow-brown solid product, which was washed with anhydrous 1,2-dichloroethane and then dried under vacuum at room temperature to obtain 127 g of molybdenum dioxide dichloride (MoO2Cl2) (yield 97%).

[0063] The obtained product (MoO2Cl2) was purified by sublimation (90°C / 180 mtorr) to obtain 121 g of a pale yellow solid product (yield 87%).

[0064] The obtained yellow solid product (MoO2Cl2) was analyzed using TGA analysis. The TGA analysis results were the same as those of molybdenum dioxide dichloride (MoO2Cl2, CAS Number 13637-68-8) purchased from Sigma-Aldrich. These results indicate that the compound prepared by the method for preparing molybdenum dioxide dichloride of the present invention is molybdenum dioxide dichloride (see Figure 1).

[0065] The TGA analysis was performed using a Mettler Toledo TGA / DSC 3+, with the test material being heated at a rate of 10°C / min up to 500°C.

[0066] Furthermore, the obtained yellow solid product (MoO2Cl2) was shown to have a purity of 99.999% or more through ICP-MS analysis (Figure 2).

[0067] The ICP-MS analysis was performed using a Thermo Scientific XSeries 2.

[0068] <Example 2> The same synthesis method as in Example 1 was used, 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). 12 g of molybdenum dioxide dichloride (MoO2Cl2) was obtained (87% yield). The obtained molybdenum dioxide dichloride (MoO2Cl2) was purified by sublimation in the same manner as in Example 1, yielding 11 g of a pale yellow solid product (MoO2Cl2) (79% yield).

[0069] Example 3 The same synthesis method as in Example 1 was used, 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), to obtain 11 g of molybdenum dioxide dichloride (MoO2Cl2) (yield 82%). The obtained molybdenum dioxide dichloride (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%).

[0070] Example 4 The synthesis was carried out in the same manner 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 under reflux with stirring for 16 hours (MoO3:SOCl2 = 1:1). Before purification, 10 g of molybdenum dioxide dichloride was obtained in a 72% yield, and after purification, 9 g of a pale yellow solid product was obtained in a 68% yield.

[0071] <Example 5> The synthesis was carried out in the same manner 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 at 60°C for 24 hours (MoO3:SOCl2 = 1:1). Before purification, 10 g of molybdenum dioxide dichloride was obtained in a 76% yield, and after purification, 7 g of a pale yellow solid product was obtained in a 49% yield.

[0072] <Comparative Example 1> The synthesis was carried out in the same manner as in Example 1, using 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous heptane, and 8.2 g (0.069 mol) of thionyl chloride, and refluxing with stirring for 24 hours, but the target molybdenum dioxide dichloride could not be obtained.

[0073] <Comparative Example 2> The synthesis was carried out in the same manner as in Example 1, using 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous dichloromethane, and 8.2 g (0.069 mol) of thionyl chloride, and refluxing with stirring for 24 hours, but the target molybdenum dioxide dichloride could not be obtained.

[0074] <Comparative Example 3> The synthesis was carried out in the same manner as in Example 1, using 10 g (0.068 mol) of anhydrous molybdenum trioxide, 50 ml of anhydrous toluene, and 8.2 g (0.069 mol) of thionyl chloride, and refluxing with stirring for 24 hours, but the target molybdenum dioxide dichloride could not be obtained.

[0075] <Comparative Example 4> The synthesis was carried out in the same manner as in Example 1, using 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), and refluxing with stirring for 24 hours, but the target molybdenum dioxide dichloride could not be obtained.

[0076] 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 it is obvious that those skilled in the art can make various modifications without departing from the spirit 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 by the following claims as well as equivalents thereof. [Industrial Applicability]

[0077] As described above, the method for producing molybdenum dioxide dichloride (MoO2Cl2) of the present invention does not use chlorine gas or high reaction temperatures, so it is safe and has the advantages of being able to produce it on a small scale as well as on a mass scale, making it very useful industrially.

Claims

1. 1. A method for producing molybdenum dioxide dichloride, comprising: (i) mixing anhydrous molybdenum trioxide and thionyl chloride in a non-coordinating solvent under an inert gas to form a mixture ("first step of mixture formation"); (ii) refluxing the resulting mixture under an inert atmosphere at an elevated temperature to produce a precipitated solid product ("second stage of solid product production"); and (iii) molybdenum dioxide dichloride (MoO ２ Cl ２ Separating and purifying molybdenum dioxide (MoO ２ Cl ２ a third step of separation and purification of The solvent is an aliphatic or aromatic solvent containing a halogen element and has a boiling point of 50°C to 200°C. ２ Cl ２ ) manufacturing method.

2. The non-coordinating solvent is tetrachloromethane (CCl ４ ), 1,2-dichloroethane (C ２ H ４ Cl ２ ), 1,1,1-trichloroethane, 1,1,2-trichloroethane (C ２ H ３ Cl ３ ) and chlorobenzene (C ６ H ５ 2. The molybdenum dioxide dichloride (MoO) of claim 1, characterized in that the molybdenum dioxide dichloride (MoO) is one or more non-coordinating solvents selected from the group consisting of ２ Cl ２ ) manufacturing method.

3. 2. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the molybdenum trioxide:thionyl chloride ratio (molar) used in the first step of preparing the mixture is 1:0.5 to less than 1:2.

0. ２ Cl ２ ) manufacturing method.

4. 2. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the molybdenum trioxide:thionyl chloride ratio (mol) used in the first step of preparing the mixture is 1:0.8 to 1:1.

5. ２ Cl ２ ) manufacturing method.

5. 2. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the molybdenum trioxide:thionyl chloride ratio (molar) used in the first step of preparing the mixture is 1:

1. ２ Cl ２ ) manufacturing method.

6. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the reflux stirring in the second stage of producing the solid product is carried out at a temperature of 50°C to 200°C. ２ Cl ２ ) manufacturing method.

7. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the reflux stirring in the second stage of producing the solid product is carried out at a temperature of 70°C to 120°C. ２ Cl ２ ) manufacturing method.

8. The molybdenum dioxide dichloride (MoO) according to claim 1, wherein the reflux stirring in the second stage of producing the solid product is carried out at a temperature of 80°C to 100°C. ２ Cl ２ ) manufacturing method.

9. The inert gas in the reaction vessel in the first stage of producing the mixture and the second stage of producing the solid product is nitrogen (N ２ 2. The molybdenum dioxide dichloride (MoO) according to claim 1, characterized in that the gas is one or more selected from the group consisting of argon (Ar) and helium (He). ２ Cl ２ ) manufacturing method.

10. The reaction time of the reflux stirring is 16 to 72 hours. ２ Cl ２ ) manufacturing method.

11. Molybdenum dioxide dichloride (MoO ２ Cl ２ The molybdenum dioxide dichloride (MoO) according to claim 1, characterized in that the third stage of the separation and purification is a sublimation method. ２ Cl ２ ) manufacturing method.

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