Chemistry Reference
In-Depth Information
C
8
F
17
F
17
C
8
C
8
F
17
Perfluorinated alkyl radicals
C
8
F
17
I
O
O
R
R
R
O
O
R
R
R
R
R
N
2
+
BF
4
-
-1V
R
Fig. 24 Radical additions on CNTs
Radical Additions
This strategy takes advantage of the high reactivity of radical species produced
either photochemically or thermally. Photolysis of heptadecafluoro-n-octyl iodide
generating the correspondent alkyl radical was exploited by Holzinger et al.
(Fig.
24
) for covalent functionalization of CNTs with perfluorinated alkyl
chains [
100
].
The same type of derivatization is achievable by reaction of the nanotubes with
organic peroxides under thermal conditions or with aromatic ketones photoreduced
by alcohols [
101
,
102
].
A further example of versatile and widely diffused sidewalls functionalization
strategy is the so-called Tour reaction (Fig.
24
), in which aryl groups can be
appended on nanotubes by means of electrochemical reduction of the correspon-
dent diazonium salts [
103
]. The degree of functionalization achievable with this
approach corresponds to 1 functional group out of 20 carbon atoms of the carbon
framework. Several examples have been reported by the same group with the aim
of improving this methodology and rendering the procedure rapid and useful.
In subsequent works the authors described how to obtain the same derivatives by
direct treatment of the nanotubes with aryl diazonium tetrafluoroborate salts,
