Chemistry Reference
In-Depth Information
IR
(characteristic bands in cm
-1
): 3507 (m), 2955/2924/2870/2851 (s), 1467 (m),
1456 (m), 1383 (m), 1342 (m), 1086 (s), 1013 (w), 945 (m), 916 (m), 814 (s), 768 (w),
723 (m), 600 (w), 565 (w), 529 (w)
5.3.4 Azide-experiment (Q
7
)
5
[
D
SiW
11
O
39
Fe(H
2
O)] + NaN
3
0.677 g (0.14 mmol) of (Q
7
)
5
[SiW
11
O
39
Fe(H
2
O)] were dissolved in 25 ml of dry
chloroform and 0.055 g (0.84 mmol; 6 eq.) of NaN
3
added under nitrogen atmosphere
applying normal Schlenk technique. The reaction mixture was stirred at 45 °C for 4 h.
Not reacted sodium azide was filtered off and the bright yellow solution split into two
parts (ca. 50% each). One part was directly freed from solvent and dried at the vacuum
to yield a yellow highly viscous liquid.
The other part was transferred into an EPR quartz tube and photolyzed for 24 h with an
150 W medium-pressure mercury light source (Heraeus TQ-150, UV Consulting Peschl
O
max
= 365 nm equipped with a pyrex deep-UV cutoff filter
O
cutoff
= 320 nm) which
resulted in a dark blue solution that was also freed from the solvent and dried at the
vacuum.
5.3.5 CO-experiments
A concentrated solution of (Q
7
)
5/6
(
D
-SiW
11
O
39
M(H
2
O)) (M = Cu
II
, Mn
II
, Fe
III
) as well as
(Q
7
)
8
(
D
-SiW
11
O
39
) in toluene was prepared in a schlenk tube sealed from air via septum.
Utilizing a syringe a constant stream of CO was bubbled for 5 hours through the solution
under vigorous stirring. The following color changes occurred: (Q
7
)
6
(
D
-
SiW
11
O
39
Cu(H
2
O)): turquoise to lime green. (Q
7
)
6
(
D
-SiW
11
O
39
Mn(H
2
O)): purple to
orange. (Q
7
)
5
(
D
-SiW
11
O
39
Fe(H
2
O)): no visual color change. (Q
7
)
8
(
D
-SiW
11
O
39
): white to
khaki.
Afterwards the solvent was removed and the highly viscous product dried at the
vacuum for 3 days and several times lyophilizing.
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