Chapter 4 - Jacobs University

Chapter 6
U-peroxo-Polyoxometalate
6.2 Synthesis
Preparation of K 6 Li 19 [Li(H 2 O)K 4 (H 2 O) 3 {(UO 2 ) 4 (O 2 ) 4 (H 2 O) 2 } 2 (PO 3 OH) 2 P 6 W 36 O 136 ]×74H 2 O (4a):
A 0.042 g (0.083 mmol) sample of UO 2 (NO 3 ) 2·7H 2 O was dissolved in 20 mL of 1M
CH 3 COOLi/CH 3 COOH buffer at pH 4.0, followed by addition of 0.181 g (0.024 mmol)
K 16 Li 2 [H 6 P 4 W 24 O 94 ]×33H 2 O (synthesized according to Contant and Tézé) 17 and after complete
dissolution 4-6 drops of 30% H 2 O 2 were added. This solution was heated to 40 °C for 1h, and
filtered hot. Then the filtrate was layered with ~1 mL of 1 M NH 4 Cl solution, and allowed to
evaporate in an open vial at room temperature. After about one week a yellow, crystalline
product started to appear. Evaporation was allowed to continue until the solution level had
approached the solid product, which was filtered off and air-dried. Yield: 0.044 g (32%, based on
uranium). IR: 1138(s), 1089(s), 1024(s), 986(sh), 944(sh), 928(s), 870(sh), 843(w), 770(s),
667(w), 472(w), 430(w), 462(w) cm -1 . Anal. Calcd (Found) for 4a: K 2.9 (2.8), Li 1.0 (1.1), W
48.7 (47.0), P 1.8 (1.7), U 14.0 (13.8).
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