Chapter 4 - Jacobs University

Chapter 2
Experimental
2.2 Preparation of starting materials
2.2.1 Synthesis of Na 9 [AsW 9 O 33 ]×27H 2 O
To a hot (~ 95 o C) solution of 110g of Na 2 WO 4 ×2H 2 O in 117 mL of distilled water, 3.67 g of
As 2 O 3 was added. Then 27.7 mL concentrated HCl was added dropwise with in 2 minutes with
continuous stirring for a period of 10 minutes and then filtered into a beaker and covered with
parafilm. The formation of crystals starts when the solution cools in the period of time. The
filtrate was left in an open beaker until the solution reached the mark of crystals. The crystals
were collected in a buchner funnel and dried an air overnight. The final compound was
characterized by FTIR spectroscopy. 1
2.2.2 Synthesis of Na 9 [SbW 9 O 33 ]×27H 2 O
Solution A: 1.96 g of Sb 2 O 3 was dissolved in 10 mL conc. HCl (may or may not dissolve
completely). Solution B: 40g of Na 2 WO 4 ×2H 2 O was dissolved in 80 mL of distilled water (~90
o C). Solution A was transferred into the beaker containing Solution B including the non
dissolved Sb 2 O 3 drop wise and then, the whole reaction mixture was refluxed for approximately
an hour. The solution was cooled and filtered, crystals start forming immediately. Solution was
left open until it reached the level of crystals. The final compound was characterized by FTIR
spectroscopy and compared to the reported spectrum. 2
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