как синтезировать K3W2Cl9

[Arseniy_al]

каким образом можно синтезировать такое вещество из вольфрамовой кислоты(H₂WO₄): K₃W₂Cl₉ 

[Paul_S]

To a mixture of 30 ml of H20 and 30 g (0.22 mole) of K2C03, 28 g (0.11 mole) of W03.H2O was added with stirring. The stirring was continued until a white slurry formed, and the mixture then was cooled to -20". This mixture was then added dropwise with stirring to 600 ml of concentrated hydrochloric acid which had also been cooled to -20'. Simultaneously, gaseous HC1 was bubbled slowly through the solution. During the last 30 min of the addition, four 25-ml portions of concentrated hydrochloric acid were added. hfter the addition of the tungstate solution iyas complete (ca. 90 min), another 100 mi of concentrated acid was added. The solution was removed from the coolant, allowed to stand for 30 min, and filtered. The filtrate was placed in a water bath at about 40' and 90 g of 200 mesh tin metal was slowly added over a period of about 75 min with continuous stirring. The color of the solution changed from blue, which occurred after the initial addition of tin, to deep wine-red and finally to a deep green. About 7 min after the appearance of the green color, the solution was placed in a Dry Ice-acetone bath and 1500 ml of absolute ethyl alcohol was immediately added. hfter the precipitation was complete, the mixture was filtered. The green product Jvas then washed with absolute ethyl alcohol, followed by anhydrous ether. The yield at this point was generally about 70%. Recrystallization was accomplished by dissolving the product in a minimum quantity of dilute hydrochloric acid (ca. 0.5 M), filtering, cooling to -15", and slowly saturating the solution with gaseous HCI. The green, crystalline product was waShed as bcfore. Thc yield is 60-62%

https://pubs.acs.org/doi/abs/10.1021/ic50054a015.