Chemistry Reference
In-Depth Information
5.3.1.4 (Q
7
)
8
[
D
-SiW
11
O
39
]
A solution of 2.5 g (0.776 mmol) K
8
[
D
-SiW
11
O
39
]
ڄ
13H
2
O (1.00 eq.) was dissolved in 50 ml
of water, heated to 50 °C and a solution of 3.04 g (6.21 mmol) THA-Br (8.00 eq.) in 80 ml
of toluene added. The mixture was vigorously stirred for 5 minutes and the organic
layer separated. After removal of the solvent toluene the light yellow highly viscous
liquid was solvent-stripped once with 50 ml toluene and three times with 50 ml
chloroform.
Yield:
1.89 g (3.1710
-4
mol, 40.9 % based on W
)
EA
in wt. - % (calculated values in brackets): C 46.28 (45.14), H 8.33 (8.12), N 1.91 (1.88)
IR
(characteristic bands in cm
-1
): 2956/2928/2860 (s), 2463 (w), 1629 (w), 1483/1467
(m), 1379 (m), 1252 (w), 1070/1059 (w), 993 (m), 890 (s), 802 (s), 744 (s), 657 (m), 531
(w)
5.3.1.5 (Q
5
-Q
8
)
n
[
D
-SiW
11
O
39
M(H
2
O)]
Synthesis: A solution of 1.05 eq. of metal salt in form of its chloride or nitrate salt was
dissolved in water and added to a solution of 1.00 eq. K
8
[
D
-SiW
11
O
39
]
ڄ
13H
2
O in water
(T = 55 °C). The mixture was stirred for 1.5 hours at 55 °C and the pH slightly acidified
with HNO
3
in case of nitrate metal salts or with HCl in case of chloride metal salts. After
cooling to room-temperature the tetraalkylammonium counter ion was added in the
ratio given in Table 5 as its bromine salt dissolved in toluene and the two-phases mixed
vigorously for a short time. Adding the tetraalkylammonium bromide in slightly lower
amounts than the stoichiometric ratio resulted in cleaner products according to
elemental analysis. The organic layer was then separated and filtered through a folded
filter before removing the solvent under reduced pressure. The resulting product was
solvent-stripped twice with 50 ml toluene and dried under vacuum at 60 °C for at least
24 h and with several times lyophilizing.
Search WWH ::
Custom Search