Chemistry Reference
In-Depth Information
tAbLe 4.26
Percentage of extraction (%) of europium and thorium nitrates from 1 M
Hno
3
into Dichloromethane at 20°C
eu
3
+
th
4
+
Ligands
C
L
=
10
−
3
M
C
L
=
10
−
2
M
C
L
=
10
−
4
M
C
L
=
10
−
3
M
OΦCMPO
69.5
12.2
TOPO
18
10.2
O
5
1
-
6
-
4
O
5
2
-
18.3
-
22
O
5
3
15
94
-
4.3
O
5
4
43.4
100
15.2
-
O
5
5
17
-
21.7
-
CPw1
35
60
CPw2
64
61.8
CPw3
58
61
CPw4
24
26
CPw5
68
53
CPw6
68
63
CPw7
72
54
CPw8
69.5
51.5
CPw9
59
50
CPw10
-
46
CPw11
20
32
CPw12
40
39
CPw13
49
43
CPw14
45
69
CPw15
48
66
CPw16
60
66
europium and only 10
−4
M for thorium. An increase of the alkyl chain length from
C
10
to C
18
does not cause any regular change in the extraction efficiency. The cyclic
pentamer extracts thorium slightly less than its tetramer counterpart. The mixed
derivatives (CPw14-CPw16), which correspond to the progressive replacement of
four CH
3
groups at the narrow rim of CPw1 by bulkier C
3
H
7
groups, show slightly
but still significantly higher extraction values for thorium than their counterparts
bearing four identical groups.
For all the calix[4]arenes, whatever the length of the linear alkyl branched to the
narrow rim, the solubility in NPHE remained very low (~10
−3
M) and even lower
than 10
−3
M for the longest alkyl chains (C
16
CPw8, C
18
CPw9) (Table 4.25).
159
It
was surprising that compared to the high lipophilicity introduced by such radicals,
interactions with NPHE arose more with phenyl-phenyl interactions than with alkyl
chains Van der Waals interactions. All the calixarenes prepared in Mainz exhibit
high extracting power toward actinides whatever their valencies. When the solubility
