Chemistry Reference
In-Depth Information
reactions similar to Eqs. (4.16 and 4.16a) [77]:
e
−
, cathode
BuO
−
(4.22)
BuOH
H
F
H
F
BuO
−
BuO
−
(
)
C
C
C
C
C
C
H
F
(4.22a)
The product contains (besides some residual F and H) also inserted
NBu
4
þ
, i.e. it is naturally n-doped. Even in the absence of BuOH, reactive
nucleophiles like [(CH
3
)
2
NCHO]
or (CH
3
)
2
N
can be generated by pre-
electrolysis of dimethylformamide solutions [59]. Such a process allows
electrochemical deposition of diamond-like carbon on an aluminum elec-
trode [78] and it also produces polyyne from PVDF (cf. Eq. 4.22a). At
similar conditions, PTFE shows no reactivity [59] and polyvinylchloride
is dehydrohalogenated only to polyacetylene [79-82]. However, trans-poly-
acetylene, which was stereoregularly chlorinated by FeCl
3
, is carbonizable
by electrochemically generated BuO
(cf. reactions 4.22 and 4.22a) [83]:
H
H
H
Cl
Cl
H
BuO
−
FeCl
3
H
Cl Cl
H
(4.23)
H
H
The presence of carbynoid structures was confirmed by IR and Raman
spectra [83].
4.2.2 C
ARBYNE
-L
IKE
M
ATERIALS
M
ADE BY
''D
RY
''
E
LECTROCHEMISTRY
The principle of electrochemical carbonization at the ''dry'' interface of
reactants was treated in Section 4.1.1 (cf. generic
reaction is a carbonization of PTFE with diluted liquid amalgams of alkali
also
Figure 4.1
). The
with regular n-doping (see
The polyyne was monitored by
1
Raman band of the C
C stretch at
2000 cm
(cf.
Figure 4.4
)
[47,48,84].
Screening of perfluoro-n-alkanes (C
x
F
2x
þ
2
, x
)
[48] pointed at PTFE giving optimum yields of polyyne. The yields fur-
ther increased in the series of alkali metal amalgams: Li<Na<K [47,48].
Further improvement was traced if highly oriented PTFE was used as
¼
1, 2, 6, 9, 20, 24,
1
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