JP3307685B2 - Method for producing β-diketonate complex of rare earth element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a process for manufacturing a superconductor, a semiconductor LSI, an optical IC, or various light-emitting materials by a chemical vapor deposition method (hereinafter abbreviated as CDV method). TECHNICAL FIELD The present invention relates to an industrial production method of a high-purity β-diketonate complex of a rare earth element, which is useful as a raw material for forming a thin film such as an oxide containing.

[0002]

2. Description of the Related Art In recent years, the CVD method has been used as an effective means for producing oxide-based ceramic thin films or layered ceramics, and has been actively studied. For example, the CVD method is used in the production of superconductors and dielectric thin films, or in the production process of integrated circuits such as LSIs and optical ICs. As raw materials,
A β-diketone metal complex excellent in volatility and reactivity, which is a complex of a β-diketone represented by the general formula R ₁ —CO—CH ₂ —CO—R ₂ and a metal, is often used.

In the periodic table of elements, scandium (Sc), yttrium (Y), and lanthanoids from lanthanum (La) to lutetium (Lu) belonging to the third group are collectively referred to as rare earth elements. Elements are important elements in electronics and optronics. Yttrium is a major constituent element of the YBC superconductor. Lanthanum is a main constituent element of the ferroelectric PLZT. Also, many lanthanoid elements are
It is used as an additive for imparting functionality as a light emitting material or the like.

[0004] The usefulness of β-diketonate metal complexes, including rare earth elements, as raw materials for CVD methods is described in T. OZAWA (thermochemica Acta, 174).
(1991)) has analyzed in detail. The production of β-diketonate complexes of rare earth elements is carried out by using Eisentra
ut) et al. (KJEISENTRAUT and RESIEVERS, J.Am.Chem.So
c,) 87 (1965))). That is, Eisentraut et al. Described typical dipivaloylmethane ((CH ₃ ) ₃ .C.
_{CO · CH 2 · CO · C} · (CH 3) 3, below, by combining a rare earth element complexes abbreviated as DPM) by the following method. That is, lanthanoid oxide is dissolved in dilute nitric acid,
Evaporate to dryness to obtain the nitrate, which is dissolved in a 50% aqueous methanol solution. On the other hand, while a methanol solution of DPM was constantly stirred, an aqueous solution of sodium hydroxide having an equimolar amount to DPM was added thereto.
% Methanol aqueous solution and stirred immediately under reduced pressure for 2 hours. Once concentrated to half volume, water is added to obtain a precipitate of the complex. The precipitate is dried in a desiccator, and then purified by sublimation under reduced pressure.

[0005]

However, when a complex is synthesized in an aqueous solution as in the above-mentioned method of Eisentraut et al., A high purity complex cannot be obtained. That is, the heat loss curve of a complex obtained by drying the complex formed by this method in a desiccator gradually starts to evaporate from 100 ° C. or less as shown by a curve A in FIG. , Indicates that the evaporation residue is also large. The thermogravimetric curve of the product obtained by vacuum drying this is curve B. Curve B
Indicates that the purity is higher than that of the curve A, but the remaining amount of evaporation is recognized. Then, by further sublimating and refining this, the residual amount of evaporation substantially disappears as shown by the curve C. This is presumably because, during the synthesis, water is taken into the complex and is not easily desorbed, and a non-volatile hydroxide partially generated by hydrolysis remains as a residue. The residue can be removed by sublimation purification, but has a problem that it is industrially uneconomical. At present, in the electronics industry, with the pursuit of high integration and high functionality of products, demands for high purity of raw materials used are becoming more and more strict, and corresponding high purity rare earth elements It has been desired to establish an industrial production method of a β-diketonate complex.

In view of the above-described situation, the present inventors have proposed a rare earth element β having a high purity, that is, having a chelate evaporation of 99.0% or more in thermogravimetric analysis.
-To establish a method for synthesizing a diketonate complex.

[0007]

According to the present invention, the rare earth element β
The method for producing a diketonate complex comprises a step of reacting an anhydrous salt of a rare earth element with β-diketone in an anhydrous organic solvent using a basic reaction accelerator to produce a solid containing the β-diketonate complex. And a step of washing the solid using pure water, and a step of vacuum-drying the solid after the washing.

Hereinafter, the present invention will be described in detail. In the method of the present invention, the synthesis reaction of the β-diketonate complex of a rare earth element is carried out not in an aqueous solution but in a dehydrated anhydrous organic solvent. Chloride is preferably used as a starting material for the rare earth element because a relatively high-purity one is easily obtained. In addition, nitrates, acetates and the like can be used in the same manner. The basic reaction accelerator is sodium hydroxide,
Pyridine and amines such as diethylamine can be used.

As the organic solvent, those that dissolve the rare earth salt as a raw material can be used, and are used after being sufficiently dehydrated with a molecular sieve or the like. In general, organic solvents are classified into (1) an amphoteric solvent which transfers and receives protons and exhibits amphoteric acid and base, and (2) an aprotic solvent having almost no proton releasing property. When the amphoteric solvent of the above (1) is further subdivided, (1) -a: a proton-donating solvent which has a strong tendency to release protons, and (1) -b; a solvent having a hydroxyl group which has almost the same tendency of giving and receiving protons ,
(1) -c; is divided into a protic solvent having a strong tendency to accept a proton. Examples of the (1) -a proton donating solvent include organic acids such as acetic acid and formic acid. (1) Examples of the solvent having a hydroxyl group of -b include alcohols and phenols. (1) Examples of the prophilic solvent of -c include amines such as diethylamine and ethylenediamine. Further, when the aprotic solvent of the above (2) is further subdivided, (2) -a;
b; weakly basic and hard to solvate with cations; phophophobic solvent; (2) -c; (2) Examples of the prophilic solvent for -a include pyridine, diethyl ether, tetrahydrofuran and the like. (2) Examples of the phophophobic solvent of -b include acetonitrile and acetone. (2) Examples of the inert solvent of -c include benzene and toluene. In the present invention, (1) -b, c, (2) -a,
Solvents belonging to b and c can be used, and those obtained by appropriately mixing these can be used.

The β-diketones used in the present invention include 2,2,6-tetramethyl-3,5-heptanedione, 2,6-dimethyl-3,5-heptanedione, dipivaloylmethane, Examples include acetylacetone, dibenzoylmethane, benzoylacetone and the like.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples. Note that the present invention is not limited to these examples. In the following examples, the organic solvent used was dehydrated as follows. That is, an appropriate amount of granular molecular sieve was placed in an Erlenmeyer flask, and an organic solvent was added thereto. In Examples 1 to 15, as the organic solvent, methanol which is a representative organic solvent having a hydroxyl group as the amphoteric solvent (1) -b in the above classification was used, and dipivaloylmethane (DPM) was used as the β-diketone. ) Was used to synthesize a rare earth element DPM complex.

Example 1 150 ml of anhydrous methanol
Sodium hydroxide 14.68 × 10 ^-2 mol
(5.87 g) and DPM 14.68 × 10 ^-2 mol
(27.05 g) and completely dissolved. on the other hand,
4.89 × 10 ^-2 mol of yttrium chloride (YCl ₃ )
Was dissolved in 50 ml of anhydrous methanol. The two solutions were mixed well, kept at about 25 ° C., and stirred for about 3 hours to complete the precipitation reaction. By adding 1,000 ml of pure water and continuing stirring for about 3 hours, the precipitate was washed with pure water to dissolve water-soluble salts. Then, the solid obtained by filtration was filtered into 10
After vacuum drying at 0 ° C. for 10 hours, Y (DPM) ₃ was obtained.
The yield of yttrium was 93%. The obtained Y (D
FIG. 1 shows a weight loss curve (TG curve, the same applies hereinafter) obtained as a result of the thermogravimetric analysis of PM) ₃ . Chelate evaporation is 10
0.0%.

Example 2 In Example 1, lanthanum chloride (LaCl ₃ ) 4.8 was used instead of yttrium chloride.
La was similarly used except that 9 × 10 ^-2 mol was used.
(DPM) ₃ was obtained. The lanthanum yield was 96%. FIG. 2 shows the result of thermogravimetric analysis of the obtained La (DPM) ₃ . The chelate evaporation was 100.0%.

Example 3 In Example 1, cerium chloride (CeCl ₃ ) 4.8 was used instead of yttrium chloride.
In the same manner except that 9 × 10 ^-2 mol was used, Ce
(DPM) ₃ was obtained. The yield of cerium was 94%. FIG. 3 shows the result of thermogravimetric analysis of the obtained Ce (DPM) ₃ . The chelate evaporation was 99.9%.

Example 4 In Example 1, praseodymium chloride (PrCl ₃ ) was used instead of yttrium chloride.
Similarly, except that 4.89 × 10 ^-2 mol was used,
Pr (DPM) ₃ was obtained. Praseodymium yield 92%
Met. FIG. 4 shows the result of thermogravimetric analysis of the obtained Pr (DPM) ₃ . The chelate evaporation was 100.0%.

Example 5 In Example 1, 4.8 of neodymium chloride (NdCl ₃ ) was used instead of yttrium chloride.
Nd was prepared in the same manner except that 9 × 10 ^-2 mol was used.
(DPM) ₃ was obtained. The neodymium yield was 96%. FIG. 5 shows the result of thermogravimetric analysis of the obtained Nd (DPM) ₃ . The chelate evaporation was 99.9%.

(Example 6) In Example 1, samarium chloride (SmCl ₃ ) was used instead of yttrium chloride.
Sm was obtained in the same manner except that 89 × 10 ^-2 mol was used.
(DPM) ₃ was obtained. The yield of samarium was 90%. FIG. 6 shows the result of thermogravimetric analysis of the obtained Sm (DPM) ₃ . The chelate evaporation was 99.9%.

(Example 7) In Example 1, instead of yttrium chloride, europium chloride (EuCl ₃ ) was used.
Similarly, except that 4.89 × 10 ^-2 mol was used,
Eu (DPM) ₃ was obtained. Europium yield 90%
Met. FIG. 7 shows the result of thermogravimetric analysis of the obtained Eu (DPM) ₃ . The chelate evaporation was 99.9%.

Example 8 In Example 1, gadolinium chloride (GdCl ₃ ) was used instead of yttrium chloride.
In the same manner, except that 4.89 × 10 ^-2 mol was used, G
d (DPM) ₃ was obtained. The gadolinium yield was 94%. FIG. 8 shows the result of the thermogravimetric analysis of the obtained Gd (DPM) ₃ . The chelate evaporation was 99.9%.

Example 9 In Example 1, terbium chloride (TbCl ₃ ) was used instead of yttrium chloride.
Tb was prepared in the same manner except that 89 × 10 ^-2 mol was used.
(DPM) ₃ was obtained. The terbium yield was 91%. FIG. 9 shows the result of thermogravimetric analysis of the obtained Tb (DPM) ₃ . The chelate evaporation was 100.0%.

Example 10 In Example 1, dysprosium chloride (DyC) was used instead of yttrium chloride.
l ₃ ) Dy (DPM) ₃ was obtained in the same manner except that 4.89 × 10 ^-2 mol was used. The dysprosium yield was 94%. FIG. 10 shows the result of thermogravimetric analysis of the obtained Dy (DPM) ₃ . Chelate evaporation is 100.
It was 0%.

Example 11 In Example 1, holmium chloride (HoCl ₃ ) was used instead of yttrium chloride.
Similarly, except that 4.89 × 10 ^-2 mol was used,
Ho (DPM) ₃ was obtained. The holmium yield was 94%. FIG. 11 shows the result of thermogravimetric analysis of the obtained Ho (DPM) ₃ . The chelate evaporation was 99.9%.

Example 12 In Example 1, erbium chloride (ErCl ₃ ) was used instead of yttrium chloride.
Similarly, except that 4.89 × 10 ^-2 mol was used,
Er (DPM) ₃ was obtained. Erbium yield was 91%. FIG. 12 shows the result of thermogravimetric analysis of the obtained Er (DPM) ₃ . The chelate evaporation was 100.0%.

Example 13 In Example 1, thulium chloride (TmCl ₃ ) was used instead of yttrium chloride.
Tm was calculated in the same manner except that 89 × 10 ^-2 mol was used.
(DPM) ₃ was obtained. The thulium yield was 90%. FIG. 13 shows the result of thermogravimetric analysis of the obtained Tm (DPM) ₃ . The chelate evaporation was 100.0%.

Example 14 In Example 1, yttrium chloride (YbC) was used instead of yttrium chloride.
l ₃ ) Yb (DPM) ₃ was obtained in the same manner except that 4.89 × 10 ^-2 mol was used. The yield of ytterbium was 93%. FIG. 14 shows the result of thermogravimetric analysis of the obtained Yb (DPM) ₃ . Chelate evaporation 99.9
%Met.

Example 15 In Example 1, lutetium chloride (LuCl ₃ ) was used instead of yttrium chloride.
Similarly, except that 4.89 × 10 ^-2 mol was used,
Lu (DPM) ₃ was obtained. The yield of lutetium was 91%. FIG. 15 shows the result of thermogravimetric analysis of the obtained Lu (DPM) ₃ . The chelate evaporation was 99.9%.

The process of the present invention can also be carried out using an organic solvent other than methanol, a rare earth salt other than chloride, and a basic reaction accelerator other than sodium hydroxide. An example will be described below.

Example 16 Lanthanum chloride (LaC)
l ₃₎ 0.407mol and (100 g) were mixed 1 liter of acetone, here DPM 1.25 mol (23
0g). Next, diethylamine ((C
₂ H _{5) 2} NH) _1.25mol a (92 g) was slowly added and refluxed for 3 hours. After cooling, the mixture was filtered, the filtrate was concentrated, and then recrystallized in ethanol. Filter the generated crystals,
Further, 300 ml of pure water was gradually poured to wash the crystals, and the crystals were vacuum-dried at 100 ° C. for 100 hours. The yield of lanthanum was 71%. The result of the thermogravimetric analysis of the obtained La (DPM) ₃ was not different from that shown in FIG.
The chelate evaporation was 100.0%.

Example 17 Cerium nitrate (Ce (NO
₃ ) ₃ ) 0.307mol (100g) and 1 liter of acetonitrile were mixed, and DPM 0.924mo was added thereto.
1 (170 g) was charged. Next, pyridine 0.9
24 mol (73 g) was gradually charged, and the mixture was refluxed for 3 hours. After cooling, the mixture was filtered, the filtrate was concentrated, and then recrystallized in n-hexane. The generated crystals are filtered off, and the pure 30
After washing by pouring 0 ml gradually, the crystals were cooled to 100 ° C.
And dried under vacuum for 100 hours. The yield of cerium was 66%. The result of thermogravimetric analysis of the obtained Ce (DPM) ₃ was not different from that shown in FIG. The chelate evaporation was 99.9%.

Example 18 Lutetium acetate (Lu (C
H ₃ COO) ₃ ) 0.284 mol (100 g) and 1 liter of dichloromethane were mixed, and DPM 0.8
70 mol (160 g) were charged. Next, 0.870 mol (105 g) of dimethylaniline was gradually added, and the mixture was refluxed for 3 hours. After cooling, the mixture was filtered, the filtrate was concentrated, and then recrystallized in isopropyl ether. The generated crystals were separated by filtration, and 300 ml of pure water was gradually poured to wash the crystals, followed by vacuum drying at 100 ° C. for 100 hours. The lutetium yield was 53%. Obtained Lu (DPM) ₃
Was not different from that shown in FIG. The chelate evaporation was 99.9%.

Comparative Example Lanthanum oxide was dissolved in dilute nitric acid and evaporated to dryness to obtain a nitrate, which was dissolved in a 50% aqueous methanol solution. On the other hand, while constantly stirring the methanol solution of DPM, an aqueous solution of sodium hydroxide in an equimolar amount to DPM was added thereto.
A 0% aqueous methanol solution was added, and the mixture was immediately stirred under reduced pressure for 2 hours. After concentrating to half volume, add water,
A precipitate of the complex was obtained. The precipitate was dried in a desiccator. This was further dried in vacuum and purified by sublimation.
FIG. 16 shows the results of thermogravimetric analysis of the complex obtained by drying in a desiccator, the one obtained by vacuum-drying the complex, and the one obtained by further sublimation purification. , B and C. The chelate evaporation of curve C was 99.1%.

[0031]

As described above, the method for producing a β-diketonate complex of a rare earth element according to the present invention comprises the steps of: reacting an anhydrous salt of a rare earth element with β-diketone in an anhydrous organic solvent using a basic reaction accelerator. To produce a solid containing the β-diketonate complex, a step of washing the solid with pure water, and a step of vacuum-drying the solid after the washing. . Therefore, an extremely high-purity β-diketonate complex containing no water can be easily obtained by vacuum drying without requiring industrially difficult and uneconomical operations such as sublimation purification.

[Brief description of the drawings]

FIG. 1 is a graph showing the results of thermogravimetric analysis of Y (DPM) ₃ obtained by the method of the present invention.

FIG. 2 is a graph showing the result of thermogravimetric analysis of La (DPM) ₃ obtained by the method of the present invention.

FIG. 3 is a graph showing the result of thermogravimetric analysis of Ce (DPM) ₃ obtained by the method of the present invention.

FIG. 4 is a graph showing the results of thermogravimetric analysis of Pr (DPM) ₃ obtained by the method of the present invention.

FIG. 5 is a graph showing the results of thermogravimetric analysis of Nd (DPM) ₃ obtained by the method of the present invention.

FIG. 6 is a graph showing the results of thermogravimetric analysis of Sm (DPM) ₃ obtained by the method of the present invention.

FIG. 7 is a graph showing the results of thermogravimetric analysis of Eu (DPM) ₃ obtained by the method of the present invention.

FIG. 8 is a graph showing the result of thermogravimetric analysis of Gd (DPM) ₃ obtained by the method of the present invention.

FIG. 9 is a graph showing the result of thermogravimetric analysis of Tb (DPM) ₃ obtained by the method of the present invention.

FIG. 10 shows Dy (DPM) ₃ obtained by the method of the present invention.
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 11 shows Ho (DPM) ₃ obtained by the method of the present invention.
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 12 shows Er (DPM) ₃ obtained by the method of the present invention.
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 13 shows Tm (DPM) ₃ obtained by the method of the present invention.
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 14 shows Yb (DPM) ₃ obtained by the method of the present invention.
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 15: Lu (DPM) ₃ obtained by the method of the present invention
4 is a graph showing the results of thermogravimetric analysis of the sample.

FIG. 16 is a graph showing an example of the result of thermogravimetric analysis of a β-diketonate complex of a rare earth element obtained by a conventional method.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07C 45/77 C07C 49/12 C07F 5/00

Claims (4)

(57) [Claims] A step of reacting an anhydrous salt of a rare earth element with β-diketone in an anhydrous organic solvent using a basic reaction accelerator to produce a solid containing a β-diketonate complex; A method for producing a β-diketonate complex of a rare earth element, comprising a step of washing a solid with pure water and a step of vacuum-drying the solid after the washing. 2. The rare earth element is scandium, yttrium, lanthanum, cerium, praseodymium, neodymium,
The method for producing a rare earth element β-diketonate complex according to claim 1, wherein the complex is any one selected from the group consisting of samarium, eurobium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. . 3. The anhydrous organic solvent is an amphoteric solvent showing an acid-base amphoteric and having a hydroxyl group, an amphoteric solvent showing an aprotic organic solvent, and an aprotic organic having almost no proton releasing property. At least one selected from the group consisting of a solvent and an organic solvent having a protophilic property, an aprotic organic solvent and an organic solvent having a protophobic property, and an aprotic organic solvent having an inert organic solvent; The method for producing a β-diketonate complex of a rare earth element according to claim 1, wherein the solvent is an anhydrous solvent comprising: 4. The rare earth element β-diketone according to claim 1, wherein the β-diketone is dipivaloylmethane.
A method for producing a diketonate complex.