JPH08151216A - Production of tetraammine-platinum (ii) dichloride - Google Patents

Abstract

PURPOSE: To provide a synthesizing method capable of producing tetraammine- platinum (II) dichloride not containing ammonium chloride, increasing an amount of a catalyst supported and improving catalytic activity in use for catalyst supporting as a cation for platinum (II). CONSTITUTION: Magnus' salt is reacted with excessive ammonia in the presence of tetraammine-platinum (II) dichloride to give tetraammine-platinum (II) dichloride. The reaction is carried out in an autoclave at 100-130 deg.C for 16 to 18 hours. After the reaction, the reaction mixture is annealed, filtered and heated until an ammonia smell no longer exists.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for synthesizing tetraammine platinum (II) dichloride ([Pt (NH ₃ ) ₄ ] Cl ₂ ) used as a cation of platinum (II) for supporting a catalyst.

[0002]

_2. Description of the Related Art Conventionally, chloroplatinum (IV) acid (H ₂ PtC) has been used to synthesize tetraammine platinum (II) dichloride.
l ₆ ) solution to magnus salt ([Pt (NH ₃ ) ₄ ] [Pt
Cl ₄ ] was prepared, ammonia was reacted in the presence of ammonium chloride, and then ammonium chloride mixed therein was removed, so that precipitation was performed with an alcohol / acetone solution for purification.

By the way, in the above-mentioned method, ammonium chloride is produced because hydrochloric acid is added at the time of amminization of the Magnus salt. In order to remove the ammonium chloride, a large amount of an organic solvent such as ethanol or acetone is used for crystallization, so that it takes a lot of time, the yield is poor, and the cost is high. Further, if ammonium chloride is used without being removed, ammonium chloride will coexist as an impurity, which is not preferable when supporting the catalyst.

[0004]

Therefore, the present invention is intended to provide a production method by which tetraammine platinum (II) dichloride containing no ammonium chloride can be obtained.

[0005]

[Means for Solving the Problems] A method for synthesizing tetraammine platinum (II) dichloride according to the present invention for solving the above-mentioned problems is to react excess ammonia while coexisting tetraammine platinum (II) dichloride in magnus salt. It is characterized by. The tetraammine platinum (I
I) The reaction of magnus salt with ammonia in the presence of dichloride is preferably heated at 100 ° C to 130 ° C for 16 hours to 18 hours, and further, the reaction is preferably performed in an autoclave. If the temperature is lower than 100 ° C, the reaction does not proceed completely, and if the temperature exceeds 150 ° C, there is a problem of decomposition, which is not preferable. If the reaction time is less than 16 hours, the reaction does not proceed completely, and if the reaction time exceeds 18 hours, the reaction progress does not change and it is wasteful.
Further, after reaction of the magnus salt and ammonia in the coexistence of tetraammineplatinum (II) dichloride, the mixture is allowed to cool, filtered, and then heated until the smell of ammonia disappears, whereby ammonia as an impurity is removed, which is more preferable. The excess amount of ammonia at the time of reaction is preferably 50 to 60% of the equivalent amount. If it is less than 50%, the reaction between the Magnus salt and ammonia will not be completed, and if it exceeds 70%, ammonia will be wasted, and further ammonia will remain as impurities, which is not preferable.

[0006]

As described above, the tetraammine platinum (II) of the present invention
The dichloride synthesis method involves adding an aqueous solution of tetraammineplatinum (II) dichloride to magnus salt, and adding ammonia water to the reaction, so that ammonium chloride is not generated by the amminization of the magnus salt and a troublesome purification step is taken. Even without, tetraammine platinum (II) dichloride free of ammonium chloride is obtained.

[0007]

EXAMPLE An example of a method for synthesizing tetraammine platinum (II) dichloride of the present invention will be described. Platinum (IV) chloride solution (Pt 15.282%) 327.2 g at 80 ° C 2 hydrazine hydrochloride 1
A solution of 4.86 g in 100 ml of water was added with stirring.
Next, after stirring at 95 to 100 ° C for 2 hours, the deposited platinum was filtered, and the filtrate was exactly divided into two equal parts. Then one platinum chloride (I
I) 85 ml of ammonia water was added to the acid solution to make the solution volume 500 ml, and then heated in an autoclave at 120 ° C. for 17 hours. Then, the mixture was allowed to cool, filtered, neutralized with 1N hydrochloric acid, and the liquid volume was adjusted to 4 liters. Then, the remaining platinum chloride (I
I) The acid solution was added with stirring for 5 minutes. After 2 hours, the generated Magnus salt was collected by filtration and washed 4 times with 300 ml of water. Next, 29 g of platinum Magnus salt was collected, and an aqueous solution of 21.4 g of tetraammineplatinum (II) dichloride synthesized by a conventional method was added. Then 60 ml of ammonia water was added to this mixture,
After adjusting the liquid volume to 500 ml, it was heated in an autoclave at 120 ° C. for 17 hours. Then, after cooling by cooling, the mixture was heated until the smell of ammonia disappeared to obtain tetraammineplatinum (II) dichloride. A quality inspection of this tetraammine platinum (II) dichloride revealed that it contained no ammonium chloride.

[0008]

PRIOR ART First, Magnus salt was prepared in the same manner as in the examples. Platinum 1.88g of Magnus salt is collected, 25ml of water,
Concentrated hydrochloric acid (2 ml) and aqueous ammonia (100 ml) were added to obtain a mixed solution, and then the mixed solution was boiled, and stirring was continued to dissolve all green precipitates. Then, the resulting solution was boiled to give an ammonia odor. Concentrate until no more, then 1 ml
After adding hydrochloric acid to acidify the mixture, add a 10-fold amount of alcohol / acetone (1: 1) mixed solution, and add tetraammineplatinum (I
I) Dichloride was precipitated, allowed to stand for 1 hour and then filtered. After that, the precipitate was washed 3 times with an alcohol / acetone solution, then with acetone alone, and finally with ether,
After drying, crystals of tetraammineplatinum (II) dichloride were obtained. As described above, in the conventional method, since ammonium chloride is formed as a by-product, a large amount of alcohol / acetone solution is required to remove the by-product, and labor and cost are large.

[0009]

As can be seen from the above description, according to the method for producing tetraammineplatinum (II) dichloride of the present invention, ammonium chloride does not form as a by-product, and ammonium chloride is not contained without tedious purification work. When used as a cation of platinum (II) for supporting a catalyst, it is possible to obtain tetraammine platinum (II) dichloride which can increase the supported amount and can improve the catalytic activity.

Claims (5)

[Claims] 1. A magnesium salt to tetraammine platinum (II)
In the production method of making dichloride, while coexisting tetraammine platinum (II) dichloride in Magnus salt,
A method for producing tetraammineplatinum (II) dichloride, which comprises reacting excess ammonia. 2. The reaction between magnus salt and ammonia in the coexistence of tetraammine platinum (II) dichloride is 100 ° C.
The method for producing tetraammineplatinum (II) dichloride according to claim 1, which is heating at from to 130 ° C for 16 to 18 hours. 3. The method for producing tetraammineplatinum (II) dichloride according to claim 2, wherein the reaction is carried out in an autoclave. 4. The tetraammine platinum (2) according to claim 2 or 3, wherein after the reaction of the magnus salt with ammonia in the coexistence of tetraammine platinum (II) dichloride, the mixture is allowed to cool and filtered and then heated until the smell of ammonia disappears. II) Method for producing dichloride. 5. The excess amount of ammonia is increased by 50 to 60% of the equivalent amount when the magnus salt reacts with ammonia in the coexistence of tetraammine platinum (II) dichloride.
3. The method for producing tetraammine platinum (II) dichloride according to 3 or 4.