Synthesis and Structural Characterization of ... - Jacobs University

Chapter 3
Published Results
3.B.1.2. Synthesis
The precursors K 14 [As 2 W 19 O 67 (H 2 O)] and Na 9 [B-α-AsW 9 O 33 ] used for the synthesis of the
reported species were synthesized according to the procedures published by Kortz 8 and
Pope, 12 respectively.
K 9.5 Na 0.5 [Yb(H 2 O) 2 K(H 2 O) 2 As 2 W 19 O 67 (H 2 O)]·25H 2 O (KNa-13)
0.10 g (0.21 mmol) of Yb(NO 3 ) 3·5H 2 O was added to 20 mL H 2 O with stirring followed by
addition of 1.0 g (0.19 mmol) of K 14 [As 2 W 19 O 67 (H 2 O)], and then the pH was adjusted to 5.5 -
6.5 with 1M NaOH (aq) . The solution was stirred at 60 ˚C for 20 min, allowed to cool to r. t. and
then filtered. 0.5 mL of 1M KCl (aq) was added to the filtrate, which was kept in an open vial for
crystallization. After about three weeks colorless crystals were obtained, which were filtered
off and air-dried (yield 1.1 g, 95 %). The IR spectrum for KNa-13 showed metal-oxygen
bands at 948(m), 891(m), 792(sh), 720(s), 615(s), 479(w), 471(w) cm −1 . –
H 60 A s2 K 10 . 5 Na 0.5 W 19 Yb (5850.6): calcd. K 7.02, Na 0.20,Yb 2.96, As 2.60, W 59.71; found K
6.99, Na 0.18, Yb 2.76, As 2.60, W 58.84.
Na 8 [La 2 (H 2 O) 6 As 2 W 19 O 67 (H 2 O)]·16H 2 O (Na-14)
0.07 g (0.19 mmol) of LaCl 3·6H 2 O was added to 20 mL of 1M NaCl (aq) with stirring, followed
by addition of 0.50 g (0.20 mmol) of Na 9 [B-α-AsW 9 O 33 ], and then the pH was adjusted to 5.0
with 1M HCl. The solution was stirred at 50 ˚C for 30 min, allowed to cool to r. t. and then
filtered. The filtrate was kept in an open vial for crystallization. After ca. three weeks
colorless crystals were obtained, which were filtered off and air-dried (yield 0.51 g, 89 %).
The IR spectrum for Na-14 showed metal-oxygen bands at 953(m), 878(w), 859(s), 796(m),
728(s), 615(w), 500(w), 484(w), 458(w) cm −1 .
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