JPH08151215A - Production of tetraammine-platinum (ii) dichloride - Google Patents

Abstract

PURPOSE: To obtain tetraammine-platinum (II) dichloride not containing ammonium chloride as a purity without using an organic solvent such as acetone or an alcohol. CONSTITUTION: Chloroplatinic (II) acid or its salt is heated with ammonia water under heating to form tetraammine-platinum (II) dichloride once, which is mixed with hydrochloric acid and heated under reflux to form precipitate of trans- dichlorodiammineplatinum (II). The filtrate is filtered, washed with eater, reacted with ammonia water again under heating to give tetraammine-platinum (II) dichloride.

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 used as a catalyst for platinum (II) as a cation.

[0002]

2. Description of the Related Art Conventionally, tetraammine platinum (II) dichloride ([Pt (NH ₃ ) ₄ ] .Cl ₂ ) has been synthesized by the following methods.
Platinum chloride (I) from a solution of platinum (IV) chloride (H ₂ PtCl ₆ )
Through I) acid (H ₂ PtCl _4), Magnus salt ([Pt
(NH ₃ ) ₄ ] [PtCl ₄ ] is prepared, reacted with hydrochloric acid in the coexistence of ammonia, and then precipitated in an alcohol / acetone solution in order to remove ammonium chloride mixed therein, and then purified. By the way, in the above method, ammonium chloride is produced because hydrochloric acid is added during the ammine conversion of the Magnus salt. In order to remove this ammonium chloride, a large amount of organic solvent such as ethanol or acetone is used for crystallization, so that it takes a lot of time and the yield is poor. Further, the amount of acetone-ethanol used is 10 times as much as that of the platinum solution, and the cost is high, and acetone, ethanol, etc. are flammable and harmful, which is not preferable for safety.
When using without removing ammonium chloride,
Ammonium chloride will coexist as an impurity,
When the catalyst is loaded, the loading amount decreases, and the catalytic activity decreases.

[0003]

Therefore, the present invention intends to provide a production method capable of obtaining tetraammineplatinum (II) dichloride free of ammonium chloride by a low cost and simple method without using acetone or ethanol. To do.

[0004]

[Means for Solving the Problems] A method for producing tetraammineplatinum (II) dichloride of the present invention for solving the above-mentioned problems is as follows. Then, tetraammineplatinum (II) dichloride is once generated, and then hydrochloric acid is added and heated under reflux to trans-dichlorodiammineplatinum (II) (t-PtCl ₂
(NH ₃ ) ₂ ) is precipitated, and the precipitate is filtered, washed well with water, and then heated and reacted again with aqueous ammonia to obtain tetraammineplatinum (II) dichloride. The heating reaction between the platinum (II) chloride acid or platinum (II) chloride salt and aqueous ammonia is preferably heating in an autoclave at 110 ° C. to 130 ° C. for 16 hours to 18 hours. If the temperature is less than 100 ° C and less than 16 hours, the reaction does not proceed completely, which is not preferable. Also, even if it exceeds 18 hours, the reaction does not proceed any further,
Further, if it exceeds 150 ° C, the problem of decomposition occurs, which is not preferable.

The heating and refluxing of tetraammineplatinum (II) dichloride and hydrochloric acid are sufficient for 17 to 19 hours. If it is less than that, the reaction will not be completed, and if it exceeds 20 hours, the yield may be lowered. is there. Furthermore, the heating reaction of trans-dichlorodiamine platinum (II) and ammonia water
It is desirable to heat at 75 ° C. to 85 ° C. for 1 hour to 2 hours. If the temperature is less than 70 ° C. and less than 1 hour, the reaction does not proceed completely, which is not preferable. After the tetraammineplatinum (II) dichloride is produced, heating is further continued until the smell of ammonia disappears, and a higher purity product free from the impurity ammonia is obtained.

[0006]

As described above, the tetraammine platinum (II) of the present invention
In the method for producing dichloride, the tetraammineplatinum (II) dichloride once produced is made into trans-dichlorodiammineplatinum (II), which is sparingly soluble in water, so that the impurities hydrochloric acid and ammonium chloride can be washed and removed, and hydrochloric acid and ammonium chloride can be removed. Tetraammineplatinum (II) dichloride is obtained which does not contain.

[0007]

EXAMPLE An example of the method for producing tetraammine platinum (II) dichloride of the present invention will be described. After heating an aqueous solution of platinum (IV) chloride (Pt 15.006%, 166.6 g) to 80 ° C., a solution of hydrazine dihydrochloride (7.24 g) dissolved in 50 ml of pure water was slowly added dropwise while stirring. After the dropping, the mixture was further heated and stirred at 100 ° C. for 2 hours, allowed to cool, and then the produced Pt black was filtered. After adding 85 ml of ammonia water to this aqueous solution of platinum (II) chloride, adjust the liquid volume to 500 ml and place it in an autoclave at 120 ° C.
Heated at 17 hours. Allow to cool and filter, add 265 ml of hydrochloric acid and add 1
The mixture was heated at 10 ° C. for 18 hours with stirring and refluxed. After cooling, the produced yellow precipitate trans-dichlorodiammine platinum (II) was collected by filtration and washed with pure water until the washing water became neutral. After drying at 35 ° C, trans-dichlorodiamine platinum (II) was added to 36.28.
g (94%) was obtained. Trans-dichlorodiammineplatinum (I
I) (12.5 g) was mixed with 30 ml of ammonia water and 170 ml of pure water, and this suspension was heated and stirred to quantitatively give a colorless tetraammine platinum (II) solution. After heating until the ammonia odor disappears, let it cool and then target tetraammine platinum (I
I) An aqueous dichloride solution was obtained.

[0008]

PRIOR ART Magnus salt was prepared from chloroplatinic (IV) acid by a conventionally known method. 1.88 g of platinum Magnus salt is collected,
Add 25 ml of water, 2 ml of concentrated hydrochloric acid, 100 ml of aqueous ammonia to obtain a mixed solution, then boil this mixed solution and continue stirring to dissolve all green precipitates, then boil the resulting solution, Concentrate until there is no odor of ammonia, then add 1 ml of hydrochloric acid to acidify and add 10 times volume of alcohol / acetone (1: 1) mixture to precipitate tetraammineplatinum (II) dichloride for 1 hour. After standing, it was filtered, and then the precipitate was washed with an alcohol / acetone solution three times, washed with acetone alone, and finally with ether, and dried to obtain tetraammineplatinum (II) dichloride crystals. As described above, in the conventional method, a large amount of alcohol / acetone solution is used in order to remove the by-produced ammonium chloride, which is not only costly but also dangerous.

[0009]

As described above, according to the method for producing tetraammineplatinum (II) dichloride of the present invention, tetraammineplatinum (II) dichloride containing no ammonium chloride can be produced without using a large amount of alcohol / acetone. It is possible to obtain tetraammineplatinum (II) dichloride capable of increasing the supported amount when used as a cation of platinum (II) for supporting a catalyst and improving the catalytic activity.

Claims (6)

[Claims] 1. Tetraammineplatinum (II) by reacting platinum (II) chloride or platinum (II) chloride with ammonia water by heating.
After once producing dichloride, hydrochloric acid is added and heated to reflux to produce a precipitate of trans-dichlorodiammineplatinum (II), and the precipitate is filtered, washed well with water, and then heated and reacted again with aqueous ammonia. A method for producing tetraammine platinum (II) dichloride. 2. The tetraammineplatinum according to claim 1, wherein the platinum (II) chloride salt is a sodium salt or a potassium salt.
(II) A method for producing dichloride. 3. The heating reaction between the platinum (II) chloride acid or platinum (II) chloride salt and aqueous ammonia is carried out in an autoclave.
The tetraammine platinum (I) according to claim 1 or 2, wherein the heating is performed at 10 ° C to 130 ° C for 16 hours to 18 hours.
I) A method for producing dichloride. 4. The method for producing tetraammineplatinum (II) dichloride according to claim 1, 2 or 3, wherein the heating and refluxing of the tetraammineplatinum (II) dichloride and hydrochloric acid are continued for 17 to 19 hours. 5. The trans-dichlorodiammine platinum
(II) and ammonia water heating reaction, 1 at 75 ℃ ~ 85 ℃
The method for producing tetraammineplatinum (II) dichloride according to claim 1, 2, 3 or 4, wherein the heating is for 2 hours to 2 hours. 6. The trans-dichlorodiamine platinum
6. The reaction of (II) with ammonia water by heating to produce tetraammineplatinum (II) dichloride, and then heating is continued until the smell of ammonia disappears. Tetraammine platinum (II)
A method for producing dichloride.