Synthesis and Structural Characterization of ... - Jacobs University

Chapter 2
Experimental
least 24 h. After this reaction time, the yellow color of the solution had become more intense.
This solution was allowed to cool to room temperature and was then treated with 150 g KCl.
The precipitate which appeared was filtered off and air-dried. This crude material was
dissolved in 650 mL water, and the solution was, eventually, filtered to remove insoluble
impurities. The clear solution was then heated to ~80°C for at least 72 h. The solution was
then allowed to cool to room temperature before being placed finally in a refrigerator at 4°C.
After a few days, the yellow crystals were collected. 11
2.3.11 Synthesis of K12[H2P2W12O48]·24H2O
83 g of K 6 [α-P 2 W 18 O 62 ]·20H 2 O were dissolved in 300 mL of water. A solution of 48.4 g
tris(hydroxymethyl)aminomethane in 200 mL water was then added. The mixture was stirred
at room temperature for 30 minutes and then 80 g of KCl were added. After complete
dissolution, a solution of 55.3 g of K 2 CO 3 in 200 mL water was added. The resulting mixture
was vigorously stirred for 15 minutes and the white precipitate that appeared after a few
minutes was filtered on a sintered glass frit, and air dried overnight, washed 2-3 times with 50
mL ethanol, dried under suction. The product was then air-dried for 3 days. 12
2.3.12 Synthesis of K28Li5[H7P8W48O184]·92H2O
In 950 mL of water were dissolved, successively, 60 g (1 mol) glacial acetic acid, 21g (0.5
mol) of lithium hydroxide, 21g (0.5 mol) of lithium chloride, and 28 g (0.07 mol) of
K 12 [H 2 P 2 W 12 O 48 ]·24H 2 O. The solution was left in an open beaker. After 9 days the volume of
the solution had evaporated to ca. 650 mL and the crystals were collected by suction filtration
on a coarse frite and washed with 40 mL ethanol (50%), 40 mL of ethanol and 40 mL of ether
and finally air-dried for 1 day. 13
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