Chapter 4 - Jacobs University

Chapter 9
Unpublished Results
9.3.7 Synthesis of K 14 [Hf (BW 11 O 39 ) 2 ]·21H 2 O (26a)
A 0.641 g (0.2 mmol) of K 9 [BW 11 O 39 ] was dissolved in 20 mL of 1M KCl solution, and then
0.064 g (0.2 mmol) of HfCl 4 was added. The pH of the solution was 2.70. The solution was
heated at 80 °C for 60 min. After 60 min heating the solution was completely cloudy. The
solution was kept overnight and then the clear solution was decanted. Then the solution was
allowed to evaporate in an open vial at room temperature. 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 airdried.
IR : 1002(m), 953(s), 891(s), 831(s),780(w), 735(s), 510(s) cm -1 .
80
75
70
65
60
55
%Transmittance
50
45
40
35
30
25
20
1100
1000
900
800
Wavenumbers (cm-1)
700
600
500
Figure 9.73 FTIR spectrum of 26a.
230