Reversible iodine absorption of nonporous coordination polymer Cu(TCNQ)

Article abstract of DOI:10.1039/c3nj01290e

Polycrystalline powders of Cu(TCNQ) (TCNQ = 7,7′,8,8′- tetracyanoquinodimethane) absorb iodine to form Cu(TCNQ)I₄ upon solid grinding with iodine or immersion in a hexane solution of iodine. Of the two polymorphs of Cu(TCNQ), phase II Cu(TCNQ) exhibits a much slower iodine-absorption rate than that of phase I Cu(TCNQ) in the liquid-phase reaction, whereas the solid grinding reaction results in efficient absorption for both phases. The valence state of the iodine-containing salt is [Cu ⁺I^-(TCNQ⁰)](I₂)_1.5, where the copper ion is coordinated with an iodide anion and neutral TCNQ. The salt is a semiconductor (σ_RT = 3 × 10^-3 S cm ^-1, compaction pellet) with an electrical conductivity one order lower than that of Cu(TCNQ). The salt releases iodine by annealing to regenerate the original phases of Cu(TCNQ) via an intermediate Cu(TCNQ)I state. A solid-state reaction of TCNQ, CuI, and iodine also produces the iodine-containing salt. The iodine absorption-desorption mechanism of Cu(TCNQ) differs from that of alkali-TCNQ salts that we reported previously.

Full text of DOI:10.1039/c3nj01290e

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Reversible iodine absorption of nonporous
coordination polymer Cu(TCNQ)†
Cite this: New J. Chem., 2014,
38, 739
Koji Miyao,a Akira Funabiki,a Kazuyuki Takahashi,a Tomoyuki Mochida*a and
Mikio Uruichib
Polycrystalline powders of Cu(TCNQ) (TCNQ = 7,70,8,80-tetracyanoquinodimethane) absorb iodine to
form Cu(TCNQ)I4 upon solid grinding with iodine or immersion in a hexane solution of iodine. Of the two
polymorphs of Cu(TCNQ), phase II Cu(TCNQ) exhibits a much slower iodine-absorption rate than that of
phase I Cu(TCNQ) in the liquid-phase reaction, whereas the solid grinding reaction results in efficient
absorption for both phases. The valence state of the iodine-containing salt is [Cu+Iꢀ(TCNQ0)](I2)1.5
,
where the copper ion is coordinated with an iodide anion and neutral TCNQ. The salt is
a
Received (in Victoria, Australia)
17th October 2013,
Accepted 27th November 2013
semiconductor (sRT = 3 ꢁ 10ꢀ3 S cmꢀ1, compaction pellet) with an electrical conductivity one order
lower than that of Cu(TCNQ). The salt releases iodine by annealing to regenerate the original phases of
Cu(TCNQ) via an intermediate Cu(TCNQ)I state. A solid-state reaction of TCNQ, CuI, and iodine also
produces the iodine-containing salt. The iodine absorption–desorption mechanism of Cu(TCNQ) differs
from that of alkali-TCNQ salts that we reported previously.
DOI: 10.1039/c3nj01290e
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Introduction
Over the last few decades, reversible absorption–desorption of
small molecules by coordination polymers and caged com-
pounds has attracted considerable attention.1 Several porous
coordination polymers absorb iodine.2 Compounds that exhibit
reversible iodine-absorption properties are useful for iodine
storage. Organic donor compounds and polymers also absorb
iodine;3 this reaction is often used to increase their electrical
conductivity. As part of our investigations into solid-state
reactions,4 we reported that powders of alkali-TCNQ salts
[M(TCNQ), M = Na, K] reversibly absorb iodine to form M(TCNQ)I,
even though they are nonporous materials.5 Iodine absorption
by such simple charge-transfer salts is uncommon and interesting
from the perspective of controlling their electronic properties.
Their simple composition and easy preparation may be advanta-
geous for practical applications.
Fig. 1 Structural formula of Cu(TCNQ).
The latter is thermodynamically more stable.7 In the current study,
the iodine-absorption properties of the two phases are investigated,
and the solid-state reaction and liquid-phase reaction are compared.
The mechanism of iodine absorption–desorption is discussed in
comparison with that of alkali-TCNQ compounds.
Results and discussion
Iodine absorption of Cu(TCNQ) by a solid-state reaction
In this paper, we report the iodine-absorption properties of The iodine absorption–desorption properties of Cu(TCNQ)
Cu(TCNQ) (Fig. 1). Cu(TCNQ) is a nonporous coordination poly- (phase I and phase II) found in the present study are sum-
mer composed of CuI and a TCNQ anion. It is a semiconductor, marized in Fig. 2. Solid-state grinding of a dark-blue powder of
and devices based on its electronic characteristics have been Cu(TCNQ) and I2 in a molar ratio of 1 : 2 produced a black
investigated;6 hence, the ability to control its physical properties powder of Cu(TCNQ)I4 within 30 min. The solid-state reaction
is useful. Cu(TCNQ) has two polymorphs: phase I and phase II. was efficient for both phases I and II. The use of excess iodine
left unreacted iodine in the resultant powder. The iodine-
containing salts obtained from the two polymorphs exhibited
almost the same amorphous X-ray diffraction (XRD) patterns
with several weak peaks (phase I: Fig. 3a, phase II: Fig. 3b).
However, their IR spectra were slightly different, indicating the
differences in their local structures.
a Department of Chemistry, Graduate School of Science, Kobe University, Kobe,
Hyogo 657-8501, Japan. E-mail: tmochida@platinum.kobe-u.ac.jp
b Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
† Electronic supplementary information (ESI) available. See DOI: 10.1039/
c3nj01290e
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phase of Cu(TCNQ), as seen in the XRD patterns (Fig. 3). This was
also confirmed by the recovery of the IR spectrum of each phase.
The recovery of the original phases is ascribed to differences in the
local structures of Cu(TCNQ)I4 derived from each polymorph.
However, the weaker XRD peak intensities suggest that the product
also contains amorphous Cu(TCNQ). In the XRD patterns, peaks
corresponding to CuI were also observed. The amount of CuI in
the sample from phase I was about 3%, as determined by X-ray
fluorescence analysis. Repeating the absorption–desorption pro-
cedure resulted in a slight increase in the CuI peak intensities and
decrease of the crystallinity of the regenerated Cu(TCNQ) (Fig. S1,
ESI†). Interestingly, phase II Cu(TCNQ) was gradually converted to
phase I Cu(TCNQ) by repeating the procedure. Conversion from
phase I to phase II occurs in solution,7 whereas the solid-state
reaction caused the reverse conversion.
Fig. 2 General reaction scheme.
Fig. 4 shows the TG traces of Cu(TCNQ)I4 prepared from
phase I Cu(TCNQ). The trace exhibits a two-step weight loss;
the losses in the first step (60–120 1C; 49.4%) and second step
(120–230 1C; 15.3%) correspond to the desorption of three and one
iodine atoms, respectively. This result indicates that Cu(TCNQ)I is
a stable intermediate state (Fig. 2). The TG trace of Cu(TCNQ)I4
prepared from phase II Cu(TCNQ) exhibited the same total weight
loss (65.1%; Fig. S2, ESI†), but with a smaller weight loss in the
second step, which is likely due to the microscopic inhomogeneity
of the product. Desorption of iodine also occurred upon immersion
of Cu(TCNQ)I4 from phase I and phase II Cu(TCNQ) in hexane,
producing Cu(TCNQ)I in 40 days.
The iodine-absorption process was investigated by stepwise
addition of iodine with grinding. The peaks of Cu(TCNQ)
disappeared in the XRD patterns of Cu(TCNQ)In (n = 1–2)
(phase I: Fig. 5, phase II: Fig. S3, ESI†). The TG curve of
Cu(TCNQ)I2 prepared from phase I Cu(TCNQ) displays a clear
two-step iodine desorption via a Cu(TCNQ)I intermediate state
(Fig. S4a, ESI†) and indicates the formation of [CuI(TCNQ)](I2)0.5
.
In contrast, the TG curve of Cu(TCNQ)I2 prepared from phase II
Cu(TCNQ) displays a continuous loss of iodine, which indicates
that the product is inhomogeneous (Fig. S4b, ESI†). This is
probably because phase II Cu(TCNQ) is less reactive because it
is more thermodynamically stable than phase I.
Fig. 3 Powder X-ray diffraction patterns of (a) phase I Cu(TCNQ) and
(b) phase II Cu(TCNQ) (i) before iodine absorption, (ii) after iodine absorption
by a solid-state reaction, and (iii) after desorption of iodine by annealing.
Triangles indicate the peaks for CuI.
Heating the iodine-containing salts generated from phase I
and phase II Cu(TCNQ) at 200 1C for 1.5 h under vacuum led
Fig. 4 Thermogravimetric traces of Cu(TCNQ)I4 prepared by solid-state
to the desorption of iodine to regenerate the corresponding reactions of phase I Cu(TCNQ).
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Fig. 5 Powder X-ray diffraction patterns of Cu(TCNQ)In (n = 1, 2, and 4)
obtained by stepwise solid-state reactions of phase I Cu(TCNQ). Triangles
indicate peaks for CuI.
Fig. 6 Powder X-ray diffraction patterns of phase I Cu(TCNQ) and its
products: (a) before iodine absorption, (b) after absorption of iodine by the
liquid-phase reaction (immersion in a hexane solution of iodine), and (c) after
desorption of iodine by annealing. Triangles indicate peaks for CuI.
In Fig. 5 and Fig. S3 (ESI†), it is noteworthy that peaks
corresponding to CuI were very evident in the XRD patterns of
Cu(TCNQ)n (n = 1 and 2) and were barely evident in the XRD
pattern of the sample with n = 4. We found that grinding of CuI,
TCNQ, and I2 produces Cu(TCNQ)I4. This reaction is probably
responsible for the disappearance of CuI during the absorption
process and requires iodine as no reaction occurred by grinding
only CuI and TCNQ. This contrasts with the results of the
reaction of alkali iodides, which produces M(TCNQ)I by grinding
with TCNQ.5 Annealing of Cu(TCNQ)I4 obtained by the grinding
reaction produced Cu(TCNQ) with the XRD pattern of phase II.
reaction without a partially doped intermediate state (Fig. 2).
For example, Cu(TCNQ)In (n = 2.1), which was obtained from a
short reaction period, comprises a 1 : 1 mixture of Cu(TCNQ)
and Cu(TCNQ)I4; Cu(TCNQ) was observed by XRD measure-
ments and two-step weight loss of Cu(TCNQ)I4 was observed by
TG analysis (Fig. S6, ESI†). This result is in sharp contrast with
the solid-state reaction, which produced a partially doped
homogeneous product (Fig. 2), as described above. The phase
separation in the liquid phase reaction probably occurs because
the reaction proceeds from the surface and the formation of
defects accelerates absorption. We further investigated the
effect of grinding. Ball-milling of Cu(TCNQ)In (n = 2.1) prepared
by the liquid-phase reaction produced a homogeneous solid,
i.e., [CuI(TCNQ)](I2)0.5, as confirmed by XRD and TG measure-
ments (Fig. S6, ESI†). This result clearly indicates that grinding
induces diffusion and the homogeneous reaction of iodine.
Iodine absorption of Cu(TCNQ) by a liquid-phase reaction
Immersion of a polycrystalline powder of phase I Cu(TCNQ)
in a hexane solution of iodine produced a black powder of
Cu(TCNQ)I4 within two weeks. In contrast, the iodine-absorption
rate of phase II was much slower, reaching only n E 0.7 after two
months; this is ascribed to the higher thermodynamic stability
of phase II than phase I. The efficiency of the solid-state reaction
for both phases, as described above, is ascribed to the mechano-
chemical effect.8
Electronic state of the iodine-containing salt
The valence state of Cu(TCNQ)I4 obtained from the liquid-phase
The powder XRD patterns of phase I Cu(TCNQ) before and reaction was investigated by Raman spectroscopy. The CQC
after iodine absorption are shown in Fig. 6. The peaks of stretching bands of TCNQ in Cu(TCNQ)I4 were observed at
phase I Cu(TCNQ) disappeared after absorption of iodine and 1451 cmꢀ1 (Fig. S7, ESI†), which indicates that TCNQ is neutral.9
new weak peaks appeared. The product exhibited higher crystal- Hence the TCNQꢀ1 in Cu(TCNQ) is oxidized upon iodine absorp-
linity than the solid-state reaction product. Heating the iodine- tion. The characteristic stretching band of I3ꢀ was not observed;10
containing salt under vacuum led to desorption of the iodine to hence, it is likely that the iodine exists as Iꢀ and/or I2. The results
regenerate phase I Cu(TCNQ). The weaker XRD peaks suggest of the Raman and TG measurements suggest that the valence
that the solid also contains amorphous Cu(TCNQ). In the XRD state of Cu(TCNQ)I4 is [Cu+Iꢀ(TCNQ0)](I2)1.5. A plausible local
patterns, peaks corresponding to CuI were also observed after structure around the copper ion is schematically shown in Fig. 7:
desorption of iodine. The TG curves of Cu(TCNQ)I4 were very four neutral TCNQ molecules and one iodide anion coordinate to
similar to those of solid-state reaction products, exhibiting two- the copper ion, and this unit forms a network structure via
step weight losses (total weight loss 65.9%; Fig. S5, ESI†).
We investigated the iodine-absorption process and found located between the units. The Cu–I bonds likely form because
that Cu(TCNQ)I4 was directly produced by the liquid phase Cu+ and Iꢀ are both soft ions according to the HSAB theory.
Cuꢂ ꢂ ꢂNC bonds; the remaining iodine molecules are probably
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whereas solid-state grinding produced homogeneous products.
Annealing of the salt led to release of iodine to selectively
regenerate the original phases of Cu(TCNQ), although the product
contains amorphous components.
This study shows that Cu(TCNQ) reversibly absorbs iodine
similarly to alkali-TCNQ, but via a different mechanism. The
iodine-containing salts produced from alkali-TCNQ are crystalline
Fig. 7 Schematic illustration of a plausible local structure around the
copper ion in Cu(TCNQ)In.
solids represented as [M+(TCNQꢀ2/3)](I3ꢀ 1/3, whereas Cu(TCNQ)I4 is
)
represented as [Cu+Iꢀ(TCNQ0)](I2)1.5, which contains Cu+Iꢀ, neutral
TCNQ, and iodine that is likely located between the coordination
networks. Reflecting the different valence states, the electrical
conductivity of alkali-TCNQ increases after iodine absorption, while
that of Cu(TCNQ) decreases. In contrast to the iodine absorption of
alkali-TCNQ, the affinity of Iꢀ and Cu+ according to the HSAB theory
plays an important role in the iodine absorption of Cu(TCNQ). The
iodine absorption–desorption properties shown here can be also
used to control the physical properties of Cu(TCNQ).
This structure accounts for the formation of Cu(TCNQ)I during
the iodine desorption process. X-ray photoelectron spectra
measurements consistently revealed that Cu(TCNQ)I produced
by iodine desorption contains Cu+ and Iꢀ; the main Cu 2p3/2 and
I 3d5/2 peaks were observed at 932 and 619 eV, respectively.7,11
The valence change in the iodine absorption reaction
([Cu+(TCNQ)ꢀ] + 0.5I2 - [Cu+Iꢀ(TCNQ0)]) is reasonable in
terms of the redox potentials. Oxidation of TCNQ by iodine is
possible due to the comparable redox potentials of TCNQ/TCNQꢀ
(0.22 V,12a vs. SCE in CH3CN) and I2/Iꢀ (0.22 V, ref. 12b), and the
product is further stabilized by the formation of the Cu–I bond.
The redox potentials including those of the copper ions (Cu+/Cu:
ꢀ0.5 V, Cu2+/Cu+: 1.05 V, ref. 12c and d) are consistent with the
invariant copper valency. The triiodide anion is not formed due to
the Cu–I bond formation despite the favorable redox potential
(I2/I3ꢀ: 0.62 V, ref. 12b).
The proposed structure and valence state are reasonable
considering that an analogous CuI complex containing a
thiophene-fused DCNQI (3,7-dimethyl-N,N0-dicyanobenzo-
[1,2-b:4,5-b0]dithiophene-4,8-dionediimine, abbreviated as TP-DCNQI),
has a valence state of [Cu+Iꢀ(TP-DCNQI)0] and contains a Cu–I bond.13
The electrical conductivity of a compaction pellet of Cu(TCNQ)In
(n = 3.7, obtained by the liquid phase reaction) was 3.1 ꢁ
10ꢀ3 S cmꢀ1 at room temperature, which is one order lower than
that of phase I Cu(TCNQ).7 The decreased conductivity is consistent
with the valence change of TCNQ from anionic to neutral. The
conductivity seems to be rather high for a complex with neutral
TCNQ, but may be reasonable considering that [CuI(TP-DCNQI)]
containing neutral acceptors exhibits a conductivity of 7.6 ꢁ
10ꢀ3 S cmꢀ1 (single crystal).13 The temperature dependence of the
conductivity revealed semiconducting behavior with an activation
energy of 0.1 eV (Fig. S8, ESI†); this contrasts with the change in
the electrical conductivity of alkali-TCNQ, which increases upon
the absorption of iodine.5 These results demonstrate that the
affinity of Iꢀ and Cu+ is important for the iodine-absorption
mechanism of the current salt, in contrast to that of alkali-TCNQ.5
Experimental
Phase I and phase II Cu(TCNQ) samples were prepared accord-
ing to the methods described in the literature.7 The XRD data
were recorded on a Rigaku SmartLab diffractometer using
Cu Ka radiation. The FT-IR spectra were recorded on a Thermo
Nicolet Avatar 360 FT-IR spectrometer using KBr plates. Raman
spectra were obtained using a Renishaw inVia Reflex spectro-
meter at room temperature with a 488 nm laser as the excitation
light. Thermogravimetric analyses were performed at a heating
rate of 1 K minꢀ1 under a nitrogen atmosphere using a Rigaku
TG 8120 thermal analyzer. Elemental analyses were carried out
on a Yanaco MT5 analyzer. The electrical conductivity of the
compaction pellets was measured by a four-probe method with
carbon paste electrodes using a HUSO HECS-994C multichannel
resistivity meter. X-ray photoelectron spectra were recorded on a
PHI X-tool system (ULVAC-PHI) with an Al source. The amount
of CuI in the product after iodine desorption was determined by
X-ray fluorescence analysis using a Shimadzu EDX-720 energy
dispersive X-ray fluorescence spectrometer.
Iodine absorption by solid-state grinding was performed
using a Fritsch P-7 planetary ball mill. A mixture of Cu(TCNQ)
and I2 (B0.2 g) was subjected to ball-milling in a zirconia rotor
with the aid of zirconia beads (750 rpm, 30–90 min). The solid-
state reactions were carried out under solventless conditions,
but the addition of a few drops of water was found to accelerate
them. Desorption of iodine was carried out by annealing the
iodine-containing salts at 200 1C for 1.5 h under vacuum. The
liquid-phase reaction was performed by immersing a powder of
Cu(TCNQ) (97 mg, 3.6 ꢁ 10ꢀ4 mol) in a hexane solution (300 mL)
Conclusion
A nonporous coordination polymer, i.e., Cu(TCNQ), absorbs of iodine (830 mg, 3.3 ꢁ 10ꢀ3 mol) for 1–2 weeks at 12 1C. The
iodine through a solid-state grinding or liquid-phase reaction to products were collected by filtration, washed with hexane, and
produce Cu(TCNQ)I4. Both phases efficiently produced the iodine- vacuum dried for 10 min. Anal. calcd for C12H4N4CuI4: C, 18.54;
containing salt using the solid-state reaction, although the iodine- H, 0.52; N, 7.23; found: C, 18.84; H, 1.17; N, 7.25%. The reactions
absorption rate of phase II Cu(TCNQ) was much slower via the under air produced only heterogeneous mixtures containing
liquid-phase reaction. During iodine absorption, the liquid-phase hygroscopic materials; this is probably because of the reaction
reaction produced mixtures of Cu(TCNQ) and Cu(TCNQ)I4, of TCNQ anions with oxygen.14
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2, 1055–1060; (b) A. Funabiki, T. Mochida, H. Hasegawa,
K. Ichimura and S. Kimura, New J. Chem., 2011, 35, 483–488.
5 A. Funabiki, T. Mochida, K. Takahashi, H. Mori, T. Sakurai,
H. Ohta and M. Uruichi, J. Mater. Chem., 2012, 22,
8361–8366.
6 (a) K. Xiao, J. Tao, Z. Pan, A. A. Puretzky, I. N. Ivanov,
S. J. Pennycook and D. B. Geohegan, Angew. Chem., Int. Ed.,
2007, 46, 2650–2654; (b) R. Mu¨ller, O. Rouault, A. Katzenmeyer,
L. Goux, D. J. Wouters, J. Genoe and P. Heremans, Philos.
Trans. R. Soc., A, 2009, 367, 4191–4201; (c) R. S. Potember,
T. O. Poehler and R. C. Benson, Appl. Phys. Lett., 1982, 41,
548–550; (d) R. Mu¨ller, S. De Jonge, K. Myny, D. J. Wouters,
J. Genoe and P. Heremans, Solid-State Electron., 2006, 50, 602.
7 R. A. Heintz, H. Zhao, X. Ouyang, G. Grandinetti, J. Cowen
and K. R. Dunbar, Inorg. Chem., 1999, 38, 144–156.
8 (a) F. Toda, Organic Solid State Reactions, Springer, Berlin,
Heidelberg, 2002; (b) Z. V. Todres, Organic Mechanochemistry
and its Practical Applications, Taylor & Francis, Boca Raton,
2006; (c) M. K. Beyer and H. Clausen-Schaumann, Chem.
Rev., 2005, 105, 2921–2948; (d) A. Stolle, T. Szuppa, S. E. S.
Leonhardt and B. Ondruschka, Chem. Soc. Rev., 2011, 40,
2317–2329; (e) G. Kaupp, CrystEngComm, 2009, 11, 388–403;
( f ) D. Braga and F. Grepioni, Angew. Chem., Int. Ed., 2004, 43,
4002–4011; (g) S. L. James, C. J. Adams, C. Bolm, D. Braga,
Acknowledgements
We thank Prof. H. Onishi for X-ray fluorescence analysis,
Prof. T. Uchino for his help with the grinding experiments,
and Dr Y. Furuie for elemental analysis. This work was supported
by MEXT KAKENHI grant number 23110719 and Nanotechnology
Platform Program (Molecule and Material Synthesis) of MEXT,
Japan.
References
1 (a) Y. Inokuma, M. Kawano and M. Fujita, Nat. Chem., 2011,
3, 349–358; (b) S. T. Meek, J. A. Greathouse and M. D.
Allendorf, Adv. Mater., 2011, 23, 249–267; (c) G. Couderc
and J. Hulliger, Chem. Soc. Rev., 2010, 39, 1545–1554;
(d) S. Horike, S. Shimomura and S. Kitagawa, Nat. Chem.,
2009, 1, 695–704.
2 (a) A. Abate, M. Brischetto, G. Cavallo, M. Lahtinen,
P. Metrangolo, T. Pilati, S. Radice, G. Resnati, K. Rissanen
and G. Terraneo, Chem. Commun., 2010, 46, 2724–2726;
´
(b) G. Agusı, R. Ohtani, K. Yoneda, A. B. Gaspar, M. Ohba,
´
˜
J. F. Sanchez-Royo, M. C. Munoz, S. Kitagawa and J. A. Real,
Angew. Chem., Int. Ed., 2009, 48, 8944–8947; (c) A. Peuronen,
A. Valkonen, M. Kortelainen, K. Rissanen and M. Lahtinen,
Cryst. Growth Des., 2012, 12, 4157–4169; (d) P. Cui, L. Ren,
Z. Chen, H. Hu, B. Zhao, W. Shi and P. Cheng, Inorg. Chem.,
2012, 51, 2303–2310; (e) D. F. Sava, M. A. Rodriguez, K. W.
Chapman, P. J. Chupas, J. A. Greathouse, P. S. Crozier and
T. M. Nenoff, J. Am. Chem. Soc., 2011, 133, 12398–12401;
( f ) B. F. Abrahams, M. Mylan, S. D. Orchard and R. Robson,
ˇˇ ´
P. Collier, T. Friscic, F. Grepioni, K. D. M. Harris, G. Hyett,
W. Jones, A. Krebs, J. Mack, L. Maini, A. G. Orpen, I. P. Parkin,
W. C. Shearouse, J. W. Steed and D. C. Waddell, Chem. Soc.
Rev., 2012, 41, 413–447.
9 R. Bozio, I. Zanon, A. Girlando and C. Pecile, J. Chem. Soc.,
Faraday Trans. 2, 1978, 74, 235–248.
¨
Angew. Chem., 2003, 115, 1892–1895; (g) C. H. Gorbitz, 10 (a) M. A. Abkowitz, A. J. Epstein, C. H. Griffths, J. S. Miller
M. Nilsen, K. Szeto and L. W. Tangen, Chem. Commun.,
2005, 4288–4290; (h) Q.-K. Liu, J.-P. Ma and Y.-B. Dong,
Chem. Commun., 2011, 47, 7185–7187; (i) M. H. Zeng,
and M. L. Slade, J. Am. Chem. Soc., 1977, 99, 5304–5307;
(b) W. Kiefer and H. J. Bernstein, Chem. Phys. Lett., 1972, 16,
5–9.
Q. X. Wang, Y. X. Tan, S. Hu, H. X. Zhao, L. S. Long and 11 (a) I. H. Inoue, A. Kakizaki, H. Namatame, A. Fujimori,
M. Kurmoo, J. Am. Chem. Soc., 2010, 132, 2561–2563;
( j) H. Kitagawa, H. Ohtsu and M. Kawano, Angew. Chem.,
Int. Ed., 2013, 52, 12395–12399.
A. Kobayahi, R. Kato and H. Kobayashi, Phys. Rev. B: Condens.
Matter Mater. Phys., 1992, 45, 5828–5833; (b) A. V. Generalov
and A. S. Vinogradov, Phys. Solid State, 2013, 55, 1136–1147.
3 (a) H. Akamatu, H. Inokuchi and Y. Matsunaga, Bull. Chem. 12 (a) S.-S. Pac and G. Saito, J. Solid State Chem., 2002, 168,
Soc. Jpn., 1956, 29, 213–218; (b) H. Shirakawa, E. J. Louis,
A. G. MacDiarmid, C. K. Chiang and A. J. Heeger, J. Chem.
Soc., Chem. Commun., 1977, 578–580; (c) C. K. Chiang,
Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis and
A. G. MacDiarmid, J. Chem. Phys., 1978, 69, 5098–5104;
(d) Handbook of Advanced Electronic and Photonic Materials
486–496; (b) J. Datta, A. Bhattacharya and K. K. Kundu, Bull.
Chem. Soc. Jpn., 1988, 61, 1735–1742; (c) J. M. Rosamilia and
B. Miller, J. Electrochem. Soc., 1989, 136, 1053–1059;
(d) A. R. Harris, A. K. Neufeld, A. P. O’Mullane, A. M.
Bond and R. J. S. Morrison, J. Electrochem. Soc., 2005, 152,
C577–C583.
and Devices, Conducting Polymers, ed. H. S. Nalwa, Academic 13 K. Takahashi, Y. Mazaki and K. Kobayashi, Chem. Commun.,
Press, New York, 2001, vol. 8; (e) R. N. Lyubovskaya,
D. V. Konarev, E. I. Yudanova, O. S. Roschupkina, Yu. M. 14 (a) M. Sorm and S. Nespu˚rek, Acta Polym., 1985, 36, 433–439;
1996, 2275–2276.
ˇ
ˇ
Shul’ga, V. N. Semkin and A. Graja, Synth. Met., 1997, 84,
741–742.
4 (a) A. Funabiki, H. Sugiyama, T. Mochida, K. Ichimura,
T. Okubo, K. Furukawa and T. Nakamura, RSC Adv., 2012,
(b) M. R. Suchanski and R. P. Van Duyne, J. Am. Chem. Soc.,
1976, 98, 250–252; (c) M. C. Grossel, A. J. Duke, D. B.
Hibbert, I. K. Lewis, E. A. Seddon, P. N. Horton and
S. C. Weston, Chem. Mater., 2000, 12, 2319–2323.
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