Chapter 4 - Jacobs University

Chapter 9
Unpublished Results
9.3 Zirconium- and Hafnium-containing Polyoxometalates
9.3.1 Synthesis of Cs 9 Na 2 [Zr 6 (µ 3 -O) 4 (OH) 4 (H 2 O) 2 (CH 3 COO) 5
(AsW 9 O 33 ) 2 ]·87H 2 O (20a)
A 0.246 g (0.1 mmol) of Na 9 [α-AsW 9 O 33 ] was dissolved in 20 mL of 0.5M LiOAc buffer
solution (pH 4.0) and then 0.0466 g (0.2 mmol) of ZrCl 4 was added. The solution was heated at
80 o C for 1h and filtered while hot. Then 1M CsCl (0.05 mL) solution was added after filtration.
Slow evaporation at room temperature led to the appearance of white crystalline product after
about one week. Evaporation was allowed to continue until the solution level approached the
solid product, which was filtered off and air-dried.
Yield 0.112g (50%). IR : 1637(m), 1617(m), 1577(s), 947(s), 870(vs), 783(m), 728(w),691(w),
642(w), 457(m) cm -1 .
70
65
60
55
50
%Transmittance
45
40
35
30
25
20
15
1800
1600
1400
1200
Wavenumbers (cm-1)
1000
800
600
Figure 9.51 FTIR spectrum of 20a.
207