Selective anion-induced helical aggregation of chiral amphiphilic polythiophenes with isothiouronium-appended pendants

Article abstract of DOI:10.1080/10610278.2010.506546

An optically active isothiouronium-attached polythiophene 1poly has been prepared for the first time by oxidative polymerisation of (S)-3-(3-(N-(2-(2- methoxyethoxy)ethyl)-N-(1-phenylethyl)-S-isothiouronio)propoxy) -4-methylthiophene 1 with FeCl3. The ana

Full text of DOI:10.1080/10610278.2010.506546

This article was downloaded by: [University of New Mexico]
On: 13 October 2014, At: 18:27
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
Supramolecular Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/gsch20
Selective anion-induced helical aggregation of chiral
amphiphilic polythiophenes with isothiouronium-
appended pendants
Tsuyoshi Minami a & Yuji Kubo a
a Department of Applied Chemistry , Graduate School of Urban Environmental Sciences,
Tokyo Metropolitan University , 1-1 Minami-Ohsawa, Hachioji, Tokyo, 192-0397, Japan
Published online: 27 Aug 2010.
To cite this article: Tsuyoshi Minami & Yuji Kubo (2011) Selective anion-induced helical aggregation of chiral
amphiphilic polythiophenes with isothiouronium-appended pendants, Supramolecular Chemistry, 23:01-02, 13-18, DOI:
10.1080/10610278.2010.506546
To link to this article: http://dx.doi.org/10.1080/10610278.2010.506546
PLEASE SCROLL DOWN FOR ARTICLE
Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained
in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no
representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the
Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and
are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and
should be independently verified with primary sources of information. Taylor and Francis shall not be liable for
any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever
or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of
the Content.
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any
form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://
www.tandfonline.com/page/terms-and-conditions

Supramolecular Chemistry
Vol. 23, Nos. 1–2, January–February 2011, 13–18
Selective anion-induced helical aggregation of chiral amphiphilic polythiophenes with
isothiouronium-appended pendants
Tsuyoshi Minami and Yuji Kubo*
Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University,
1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan
(Received 14 May 2010; final version received 23 June 2010)
An optically active isothiouronium-attached polythiophene 1poly has been prepared for the first time by oxidative
polymerisation of (S)-3-(3-(N-(2-(2-methoxyethoxy)ethyl)-N-(1-phenylethyl)-S-isothiouronio)propoxy)-4-methylthiophene
1 with FeCl3. The analysis carried out using gel-permeation chromatography allows us to estimate the number average
molecular weight (Mn) and the polydispersity index as 5.53 £ 105 and 1.4, respectively. Although the polymer showed an
absorption band at 420 nm with circular dichroism (CD) silence in H2O–MeOH (1:1, v/v) at 258C, the addition of anions as a
chemical stimulus was found to cause not only a bathochromic shift but also a split-type-induced CD (ICD) in the p–p
*
transition region. This phenomenon is anion selective; the most enhanced ICD spectra were obtained when hydrophobic
anions such as PF26 were added to the solution. As inferred from field emission-scanning electron microscopy observation,
the anion-ICD spectra arose from chiral aggregation of the polymer, which was effected by solvophobic effect via
the exchange with hydrophobic anions at isothiouronium pendants. Solvent polarity and temperature dependencies on the
chirality induction were investigated, the obtained results suggested that the dynamic helical aggregation of the
polythiophene backbone is based on planar interchain interactions.
Keywords: polythiophene; isothiouronium unit; chirality; anion
Introduction
capable of interacting chiral guest species could induce
helical conformer through such an interaction (9), Shinkai
et al. (10) have proposed a new way that a certain water-
soluble polythiophene is insulated by a natural helix-
forming polysaccharide, schizophyllan, to induce a
predominantly one-handed helical structure. Despite such
intriguing approaches, the investigation of chirality
manipulation on amphiphilic conjugated polymers still
remains of worth because obtained knowledge would
contribute to the methodology for structure control of
chiroptical polymers.
It is one of the fascinating research areas in material science
to study how to arrange highly ordered structures of p-
conjugated polymers because the conformation and
organisation would affect their electrical and optical
properties (1). This subject is a significant issue in their
applications such as field effect transistors (2), electro-
luminescence devices (3), solar cells (4), chemosensors (5).
Of particular interest in this field is the supramolecular
chirality control of optically active conjugated polymers
from the stand point of not only the more understanding of
stereochemical aspects in biological systems but also
potential applications to chiroptical materials (6). The use
of amphiphilic p-conjugated polymers has a merit towards
this end; the interplay of hydrophilic and hydrophobic
interactions could lead to supramolecular organisation in
aqueous solution. Nilsson et al. (7) reported chiral amino
acid-appended polythiophenes wherein the zwitterionic
side chain which acts as a hydrophilic site regulates the
conformation of the polymer backbone in water, resulting
in a helical syn conformation. In addition, amphiphilic
polythiophenes bearing enantiometrically pure oligo(ethy-
lene oxide) side chains have been prepared and character-
ised (8). Although achiral amphiphilic polythiophenes
Currently, we have focused on synthesis and charac-
teristics of polythiophenes with isothiouronium groups as a
pendant unit. The high synthetic susceptibility of the
cationic isothiouronium unit could allow us to introduce
functional groups at R1, R2 and R3 sites (Scheme 1(a)).
With this in mind, we previously reported the related
polythiophene (Scheme 1(b)) which exhibited a phytate
sensing in water (11). Its highly sensitive aggregation
property triggered by anion as a chemical stimulus
motivated us to prepare the next target.
Herein, we report a new type of optically active
polythiophene 1poly which has been readily prepared
by introducing (S)-phenylethylamino unit into the
*Corresponding author. Email: yujik@tmu.ac.jp
ISSN 1061-0278 print/ISSN 1029-0478 online
q 2011 Taylor & Francis
DOI: 10.1080/10610278.2010.506546
http://www.informaworld.com

14
T. Minami and Y. Kubo
the polydispersity index were estimated to be 5.53 £ 105
(a)
R2
(b)
and 1.4, respectively. The obtained 1poly is soluble not only
in water and MeOH but also aprotic solvents such as
acetone and acetonitrile. The optical properties were
estimated by means of UV–vis and fluorescence
spectroscopy. After several examinations, a stable aqueous
dispersion was obtained when H2O–MeOH (1:1, v/v) was
employed; the absorption and fluorescence maxima were
observed at 420 and 535 nm (lex ¼ 420 nm), respectively
(Figure 1). In the latter case, the fluorescence quantum
yield was estimated to be 2.4% using fluorescein as the
reference (15).
NH
NH
R1
Br
S
O
X
S
O
S
R3
n
N
H
N
O
H
Scheme 1. Structures of isothiouronium derivatives.
isothiouronium pendant. The amphiphilic properties led
to a selective anion-induced helical aggregation in aqueous
solution.
Anion-induced helical chirality
Results and discussion
The introduction of chirality into the pendants allowed us
to use circular dichroism (CD) spectroscopy to estimate
the conformational process occurring in the formation of
supramolecular structures. In H2O–MeOH (1:1, v/v) at
258C, the polythiophene 1poly (1.0 £ 1024 M/unit) exhibits
Synthesis
The synthetic path towards 1poly is shown in Scheme 2.
Because a variety of isothiocyanate derivatives are
commercially available, chiral functional group can be
appended into the pendant segment. We thus decided to
employ (S)-(1-isothiocyanatoethyl)benzene 2 as starting
material (12). It was allowed to react with 2-(2-
methoxyethoxy)ethylamine (13) to afford the correspond-
ing thiourea 3 in 54% yield, being followed by the reaction
with 3-(3-bromopropoxy)-4-methylthiophene (10) to
afford the desired monomer 1 in 46% yield. The structure
assignment of monomer 1 was carried out using several
spectroscopic data (see Experimental section); the
insertion of an isothiouronium unit was identified by
means of the 1H NMR measurement (d ¼ 8.74–8.76,
10.37 ppm). The polymerisation of 1 using FeCl3 as an
no CD pattern in the p–p transition region, which
*
indicates that 1poly adopts a random-coil conformation
under these conditions. Taking the cationic character of
isothiouronium unit into account, we investigated how the
addition of an anion into the solution would affect the
conformation of 1poly. Figure 2 shows the change in CD
and UV–vis spectra of 1poly upon addition of incremental
amounts of PF26 as a putative chemical stimulus in
H2O–MeOH (1:1, v/v) at 258C where 10 mM of NaCl was
added into the solution to maintain the ionic strength of the
reaction solution. The PF62 addition caused a significant
red shift in the absorption spectra with an apparently
isosbestic point at 460 nm, appearing as a new absorption
band with well-resolved vibronic transitions at l ¼ 510,
540 and 590 nm. The spectral change brought about a
colour change from yellow to purple. In addition, an
intense split-type-induced CD (ICD) was observed upon
the addition of PF26 (Figure 2(a)), where the zero-crossing
point close to the absorption maximum at 543 nm indicates
the presence of strong exciton coupling between
polythiophene backbones. Taken together, the distinct
red shift in the absorption band and the appearance of
1
oxidising agent was carried out in dry CHCl3. The H
NMR measurement allowed us to observe the disappear-
ance of signals arising from the terminal thiophene ring,
which implied that the polymerisation of 1 proceeded. We
reasoned that under the reaction conditions using dry
CHCl3 as a solvent no anion exchange reaction occurred
on the cationic side chain (14). The obtained polymer
1poly was then analysed by using gel-permeation
chromatography (GPC) with a polystyrene standard,
where the number average molecular weight (Mn) and
CH3
CH3
H
H
NH
NH
Br
Br
S
S
NH
NH
S
O
O
CH3
(i)
(ii)
(iii)
O
CH3
N
N
O
O
O
H
NCS
H
H
S
S
H
n
O
O
2
3
1
1poly
Scheme 2. Reagents and conditions: (i) 2-(2-methoxyethoxy)ethylamine, MeOH, room temperature, 21 h, 54%; (ii) 3-(3-
bromopropoxy)-4-methylthiophene, dry EtOH, 708C, 93 h, 46% and (iii) FeCl3, dry CHCl3, room temperature, 12 h.

Supramolecular Chemistry
15
Figure 1. UV–vis and fluorescence spectra of 1poly
(1.0 £ 1024 M/unit) in H2O–MeOH (1:1, v/v) at 258C.
lex ¼ 420 nm.
bisignate CD spectra (Davydov splitting) are characteristic
of the p-stacked chiral aggregation of the polythiophene
(16), the ICD pattern being assigned as a p-helix.
The evidence of PF26 -induced aggregation came from a
field emission-scanning electron microscopy (FE-SEM).
The images were taken from the samples obtained by drying
the H2O–MeOH (1:1, v/v) solution on an aluminium foil.
Whereas 1poly indicates a well-isolated state without any
aggregation (Figure 3(a)), the image of the solution after
PF26 addition clearly indicates a networked structure
consisting of fibril-like aggregates (Figure 3(b)).
Figure 3. FE-SEM images of (a) 1poly (1.0 £ 1024 M/unit) and
(b) 1poly (1.0 £ 1024 M/unit) aggregated by adding KPF6 (5 mM).
The scale bar corresponds to 100 nm.
Anion selectivity for the chirality induction
Our interest is to see whether such a dynamic aggregation
would be anion selective. We carried out CD titration
experiments in H2O–MeOH (1:1, v/v) at 258C; change in the
intensity at 600 nm in the CD spectra was plotted as a function
of the concentration of added anion where F2, Cl2, Br2, I2,
AcO2, HPO422 (equilibrating with H2PO24 under neutral
conditions), adenosine 5-triphosphate (ATP), BF24 , ClO42 and
PF26 were employed as guest anions. As shown in Figure 4, a
steep increase in CD intensity was observed upon addition of
.1 £ 1023 M of PF26 into the solution, meaning that chiral
aggregation switched on at the anion concentration. We thus
defined the concentration as aggregation point which,
consequently, was dependent on anions used in the following
order: PF26 (1 £ 1023 M) . ClO42 (5 £ 1023 M) . BF42
(3 £ 1022 M), I2 (4 £ 1022 M). Indeed, the addition of I2
did not induce such aggregation so efficiently; the CD
intensity in the presence of 1.0 £ 1021 M of I2 was 5.6 times
lower than that when 5 £ 1023 M of PF26 was added into the
solution. On the other hand, there was no change in the CD
spectra upon addition of F2, Cl2, Br2, AcO2, HPO422 and
ATP. From these results, the addition of hydrophobic anions
was effective for the chiral aggregation behaviour, suggesting
that anion exchange with hydrophobic anions at isothiour-
onium units should diminish the hydrophilicity of the side
Figure 2. CD (a) and UV–vis (b) spectra of 1poly
(1.0 £ 1024 M/unit) in the addition of an incremental amount
of KPF6 in H2O–MeOH (1:1, v/v) with NaCl (10 mM) at 258C.
[KPF6] ¼ 0, 0.3, 0.6, 1, 2, 3 and 5 mM. The data was collected
within 10 min after mixing 1poly with KPF6.

16
T. Minami and Y. Kubo
Figure 4. ICD of 1poly (1.0 £ 1024 M/unit) by anions at various concentrations in H2O–MeOH (1:1, v/v) with NaCl (10 mM) at 258C.
The CD intensities were monitored at 600 nm. The data was collected within 10 min after mixing 1poly with anions. The guest
concentration ranges from (a) 0 to 10 mM and (b) to 100 mM. KPF (X), NaClO (A), KF ( ), KCl ( £ ), KBr (þ), KI (O), ATP with
*
6
4
sodium counterion (V), K2HPO4, (S), AcOK (W) and NaBF4 (e).
chains to induce chiral aggregation. This behaviour, in turn,
might be utilised as an anion-detectable method by means of
CD spectroscopy (17).
the ratio of H2O led the absorption maximum to be red
shifted from 380 to 540 nm with showing an isosbestic point.
Taken together, the observed CD is attributable to a biased
helical aggregation of the polythiophene, the aggregation
being prompted not only by the exchange of the
isothiouronium counterion (Br2) with the hydrophobic
anion (PF26 ) but also by an increase in hydrophilicity of the
bulk environment. In addition, temperature-dependent CD
and UV–vis spectra were measured in the presence of PF62
inH2O–MeOH (1:1, v/v). As temperaturewas increased, the
CD intensities decreased significantly which became
optically silent at 708C (Figure 6(a)), being accompanied
with the thermochromic behaviour as shown in Figure 6(b).
These results strongly indicate the dynamic helical
aggregation, where planarisation of the polymer occurred
with interchain interactions.
Solvent-dependencies and temperature-dependencies on
the chirality induction
The effect of polar solvents on the chiral aggregates of 1poly
induced by PF26 was investigated by CD and UV–vis
spectroscopic methods. Figure 5 shows the obtained spectra
of 1poly in the presence of PF26 in a mixture of H2O and
MeOH with various ratios of H2O. Although the
CD spectrum was almost silent when 5 or 10% (v/v)
H2O–MeOH solution 1poly with PF26 was employed, the
intensity of the ICD signal dramatically increased as the ratio
of H2O in the solution was increased. Also, the increase in
Conclusions
Taking advantage of the synthetic susceptibility of the
isothiouronium unit, we have succeeded in synthesising
optically active polythiophenes with (S)-phenylethyliso-
thiouronium pendants. Although H2O–MeOH solution of
1poly is CD silent, selective anion-ICD spectra were detected
where the addition of hydrophobic anions such as PF26 was
most effective. To the best of our knowledge, 1poly is a new
type of chiral amphiphilic polythiophene in which helical
aggregation is promoted by hydrophobic anions in aqueous
solution. The findings would provide a new approach to
obtain polythiophene-based chiroptical materials.
Experimental section
General
NMR spectra were recorded on JEOL JNM-EX 270
(270 MHz) and JEOL Lambda 500 (500 MHz) spec-
trometers. Chemical shifts (d) are reported downfield from
the internal standard Me4Si. Fast atom bombardment
Figure 5. CD (a) and UV–vis (b) spectra of 1poly
(1.0 £ 1024 M/unit) in the presence of KPF6 (5 mM) in H2O–
MeOH of various ratios at 258C.

Supramolecular Chemistry
17
solution, the mixture was stirred at room temperature for
21 h. The resulting solution was evaporated and chro-
matographed on silica gel (Wakogel C-300, 5% (v/v)
MeOH in CHCl3). In this way, 1.78 g of 3 was obtained
(54% yield).
1H NMR (270 MHz, CDCl3) d (ppm): 1.53 (d,
J ¼ 6.91 Hz, 3H), 3.33 (s, 3H,), 3.36–3.39 (m, 2H),
3.43–3.63 (m, 6H), 4.98 (br, 1H), 6.04 (br, 1H), 6.26 (br,
1H), 7.27–7.38 (m, 5H); MS (FAB) m/z 283 [M þ H]þ.
(S)-3-(3-(N-(2-(2-Methoxyethoxy)ethyl)-N-
(1-phenylethyl)-S-isothiouronio)propoxy)-4-
methylthiophene 1
Under N2 atmosphere, 3-(3-bromopropoxy)-4-methylthio-
phene (424 mg, 6.79 mmol) was dissolved in dry EtOH
(16 ml). (S)-1-(2-(2-Methoxyethoxy)ethyl)-3-(1-phenyl-
ethyl)thiourea 3 (560 mg, 1.98 mmol), dissolved in dry
EtOH (10 ml), was added to the solution. The resulting
mixture was stirred at 708C for 93 h. After the removal of
solvent in vacuo, the residue was chromatographed on
silica gel (Wakogel C-300) using a gradient of MeOH (0–
5% (v/v)) in CHCl3 as an eluent, and further purified by
GPC using CHCl3 as an eluent. In this way, 426 mg of 1
was obtained (46% yield).
1H NMR (270 MHz, CDCl3) d (ppm): 1.62 (d,
J ¼ 8.07Hz, 3H), 2.03 (d, J ¼ 0.84Hz, 3H), 2.18 (quint,
J ¼ 6.21Hz, 2H), 3.25 (s, 3H), 3.47–3.50 (m, 2H), 3.69 (t,
J ¼ 4.21Hz, 2H), 3.75 (t, J ¼ 6.18Hz, 2H), 3.86 (br, 4H),
4.00(t, J ¼ 4.77Hz, 2H), 4.87(qunit, J ¼ 6.60Hz, 1H), 6.12
(d, J ¼ 3.29Hz,1H), 6.79–6.81(m, 1H), 7.23–7.41(m, 5H),
8.74–8.76 (br, 1H), 10.37 (br, 1H); MS (FAB) m/z 437
[M 2 Br]þ; Anal. calcd for C22H33BrN2O3S2.0.5CHCl3: C,
45.78; H, 5.85; N, 4.85. Found: C, 45.61; H, 5.93; N, 4.95.
Figure 6. Temperature-dependent CD (a) and UV–vis (b)
spectra of 1poly (1.0 £ 1024 M/unit) in the presence of KPF6
(5 mM) in H2O–MeOH (1/1, v/v) with NaCl (10 mM).
(FAB) mass spectra were obtained on a JEOL JMS-700
spectrometer where 3-nitrobenzyl alcohol was used as a
matrix. Infrared spectra were recorded on JASCO FT/IR-
5300. Elemental analyses were obtained on a Yanaco
CHNcoder MT-5. GPC was performed using a JAI recycling
preparative HPLC equipped with RI-5 RI detector. JAIGEL-
5H-A column was used for the system where N,N-
dimethylformamide (DMF) was employed as an eluent
containing lithium bromide (100mM) and phosphoric acid
(60 mM). The number average molecular weight (Mn) and
polydispersity (Mw/Mn) of the polymers were calculated on
the basis of polystyrene calibration. CD spectra were
recorded on JASCO J-820 spectropolarimeter. Fluorescence
and absorption spectra were measured using a JASCO
FP-6300 and Shimadzu UV-3100PC spectrophotometers,
respectively.
Polymer preparation (1poly
)
FeCl3 (316 mg, 1.95 mmol) was dissolved in dry CHCl3
(12 ml) under N2 atmosphere. Monomer 1 (336 mg,
0.649 mmol), dissolved in dry CHCl3 (10 ml), was added
to the solution. The mixture was then stirred for 12 h at
room temperature. The resulting precipitate was washed
with Et2O (20 ml £ 3). The product was purified by
extraction through a soxhlet extractor with Et2O (150 ml)
for 47 h and then with acetone (150 ml) for 5 h. After
evaporation, the residue was further washed with CHCl3
(30 ml) and dried in vacuo. In this way, 113 mg of 1poly was
obtained.
Materials
Unless otherwise indicated, reagents and solvents used for
this study were commercially available and used as supplied
(Tokyo Kasei [Chuo-ku, Tokyo, Japan], Kanto Kagaku
[Chuo-ku, Tokyo, Japan], Wako [Osaka, Osaka, Japan],
Aldrich [St Louis, MO, USA]). The water and methanol for
spectroscopic as for well as SEM measurements were
purchased in analytical grade and used as received.
1H NMR (500 MHz, DMSO-d6) d (ppm): 1.24–1.44
(br, 3H), 1.97 (s, 3H), 2.23 (br, 2H), 3.13 (s, 3H), 3.37 (br,
10H), 3.83 (br, 2H), 4.87 (br, 1H), 7.17–7.25 (br, 5H), 9.61
(br, 2H); IR (KBr): n ¼ 3364, 2922, 1179 cm21; GPC: Mn
(S)-1-(2-(2-Methoxyethoxy)ethyl)-3-(1-phenylethyl)
thiourea 3
(S)-(1-Isothiocyanatoethyl)benzene (1.92 g, 11.8 mmol)
2 was dissolved in MeOH (14 ml). After 2-(2-methox-
yethoxy)ethylamine (1.39 g, 11.6 mmol) was added to the
5.53 £ 105 gmol21
,
polydispersity: 1.4; UV–vis:

18
T. Minami and Y. Kubo
(6) (a) Langeveld-Voss, B.M.W.; Janssen, R.A.J.; Christiaans,
M.P.T.; Meskers, S.C.J.; Dekkers, H.P.J.M.; Meijer, E.W.
J. Am. Chem. Soc. 1996, 118, 4908–4909. (b) Langeveld-
Voss, B.M.W.; Christiaans, M.P.T.; Janssen, R.A.J.; Meijer,
E.W. Macromolecules 1998, 31, 6702–6704. (c) Iarossi, D.;
Mucci, A.; Parenti, F.; Schenetti, L.; Seeber, R.; Zanardi, C.;
Forni, A.; Tonelli, M. Chem. Eur. J. 2001, 7, 676–685. (d)
Zhang, Z.-B.; Fujiki, M.; Motonaga, M.; Nakashima, H.;
Torimitsu, K.; Tang, H.-Z. Macromolecules 2002, 35, 941–
944. (e) Goto, H.; Okamoto, Y.; Yashima, E. Chem. Eur. J.
2002, 8, 4027–4036. (f) Goto, H.; Yashima, E. J. Am.
Chem. Soc. 2002, 124, 7943–7949. (g) Zhang, Z.-B.;
Fujiki, M.; Motonaga, M.; McKenna, C.E. J. Am. Chem.
Soc. 2003, 125, 7878–7881. (h) Saito, F.; Takeoka, M.;
Rikukawa, M.; Sanui, K. Synth. Met. 2005, 153, 125–128.
(i) Cagnoli, R.; Lanzi, M.; Mucci, A.; Parenti, F.; Schenetti,
L. Polymer 2005, 46, 3588–3596. (j) Koeckelberghs, G.;
Vangheluwe, M.; Samyn, C.; Persoons, A.; Verbiest, T.
Macromolecules 2005, 38, 5554–5559. (k) Van den Bergh,
K.; Huybrechts, J.; Verbiest, T.; Koeckelberghs, G. Chem.
Eur. J. 2008, 14, 9122–9125. (l) Vangheluwe, M.; Verbiest,
T.; Koeckelberghs, G. Macromolecules 2008, 41, 1041–
1044. (m) Haraguchi, S.; Tsuchiya, Y.; Shiraki, T.;
Sugikawa, K.; Sada, K.; Shinkai, S. Chem. Eur. J. 2009,
15, 11221–11228.
lmax ¼ 420 nm in H2O–MeOH (1:1, v/v); fluorescence:
lem ¼ 535 nm (lex ¼ 420 nm) in H2O–MeOH (1:1, v/v).
FE-SEM measurements
The samples were dissolved in H2O–MeOH (1:1, v/v) and
dried under reduced pressure on an aluminium foil. They
were shielded by Au and examined with a JEOL JSM-
7500F scanning electron microscope.
Acknowledgements
This research has been supported by a Grant-in-Aid for Scientific
Research (C) from Education, Science, Sport and Culture of
Japan (No. 21550137).
References
(1) (a) Leclerc, M. Adv. Mater. 1999, 11, 1491–1498. (b)
¨
Nilsson, K.P.R.; Rydberg, J.; Baltzer, L.; Inganas, O. Proc.
Natl. Acad. Sci. USA 2003, 100, 10170–10174. (c) Hoeben,
F.J.M.; Jonkheijm, P.; Meijer, E.W.; Schenning, A.P.H.J.
Chem. Rev. 2005, 105, 1491–1546. (d) Aoki, T.; Kaneko,
T.; Teraguchi, M. Polymer 2006, 47, 4867–4892.
¨
(7) Nilsson, K.P.R.; Olsson, J.D.M.; Konradsson, P.; Inganas,
O. Macromolecules 2004, 37, 6316–6321.
(2) (a) Sirringhaus, H.; Tessler, N.; Friend, R.H. Science 1998,
280, 1741–1744. (b) Dimitrakopoulos, C.D.; Malenfant,
P.R.L. Adv. Mater. 2002, 14, 99–117. (c) Ong, B.S.; Wu, Y.;
Li, Y.; Liu, P.; Pan, H. Chem. Eur. J. 2008, 14, 4766–4778.
(d) Wu, W.; Liu, Y.; Zhu, D. Chem. Soc. Rev. 2010, 39,
1489–1502.
(8) Brustolin, F.; Goldoni, F.; Meijer, E.W.; Sommerdijk,
N.A.J.M. Macromolecules 2002, 35, 1054–1059.
(9) (a) Li, C.; Numata, M.; Takeuchi, M.; Shinkai, S. Chem.
Asian J. 2006, 1–2, 95–101. (b) Yao, Z.; Li, C.; Shi, G.
Langmuir 2008, 24, 12829–12835. (c) Ho, H.-A.;
´
Boissinot, M.; Bergeron, M.G.; Corbeil, G.; Dore, K.;
(3) (a) Andersson, M.R.; Thomas, O.; Mammo, W.; Svensson,
¨
Boudreau, D.; Leclerc. M. Angew. Chem. Int. Ed. 2002, 41,
1548–1551.
M.; Theander, M.; Inganas, O. J. Mater. Chem. 1999, 9,
1933–1940. (b) Friend, R.H.; Gymer, R.W.; Holmes, A.B.;
Burroughes, J.H.; Marks, R.N.; Taliani, C.; Bradley,
(10) Li, C.; Numata, M.; Bae, A.-H.; Sakurai, K.; Shinkai, S.
J. Am. Chem. Soc. 2005, 127, 4548–4549.
´
¨
D.D.C.; Dos Santos, D.A.; Bredas, J.L.; Logdlund, M.;
Salaneck, W.R. Nature 1999, 397, 121–128. (c) Hughes,
G.; Bryce, M.R. J. Mater. Chem. 2005, 15, 94–107.
(11) Minami, T.; Kubo, Y. Chem. Asian J. 2010, 5, 605–611.
(12) Isobe, T.; Fukuda, K.; Tokunaga, T.; Seki, H.; Yamaguchi,
K.; Ishikawa, T. J. Org. Chem. 2000, 65, 7774–7778.
(13) Neumayer, D.A.; Belot, J.A.; Feezel, R.L.; Reedy, C.;
Stern, C.L.; Marks, T.J.; Liable-Sands, L.M.; Rheingold,
A.L. Inorg. Chem. 1998, 37, 5625–5633.
(4) (a) Coakley, K.M.; McGehee, M.D. Chem. Mater. 2004, 16,
4533–4542. (b) Li, G.; Shrotriya, V.; Huang, J.; Yao, Y.;
Moriarty, T.; Emery, K.; Yang, Y. Nat. Mater. 2005, 4, 864–
868. (c) Roncali, J. Chem. Soc. Rev. 2005, 34, 483–495.
(5) (a) McQuade, D.T.; Pullen, A.E.; Swager, T.M. Chem. Rev.
´
´
(14) Bera-Aberem, M.; Ho, H.-A.; Leclerc, M. Tetrahedron
2004, 60, 11169–11173.
¨
2000, 100, 2537–2574. (b) Nilsson, K.P.R.; Inganas, O.
(15) Demas, J.N.; Crosby, G.A. J. Phys. Chem. 1971, 75,
991–1024.
(16) Langeveld-Voss, B.M.W.; Janssen, R.A.J.; Meijer, E.W.
J. Mol. Struct. 2000, 521, 285–301.
(17) (a) Kakuchi, R.; Nagata, S.; Sakai, R.; Otsuka, I.; Nakade,
H.; Satoh, T.; Kakuchi, T. Chem. Eur. J. 2008, 14,
10259–10266. (b) Kakuchi, R.; Nagata, S.; Tago, Y.; Sakai,
R.; Otsuka, I.; Satoh, T.; Kakuchi, T. Macromolecules 2009,
42, 1476–1481. (c) Kakuchi, R.; Tago, Y.; Sakai, R.; Satoh,
T.; Kakuchi, T. Macromolecules 2009, 42, 4430–4435.
Nat. Mater. 2003, 2, 419–424. (c) Liu, B.; Bazan, G.C.
Chem. Mater. 2004, 16, 4467–4476. (d) Thomas III, S.W.;
Joly, G.D.; Swager, T.M. Chem. Rev. 2007, 107, 1339–
1386. (e) Sugiyasu, K.; Swager, T.M. Bull. Chem. Soc. Jpn.
2007, 80, 2074–2083. (f) Fan, L.-J.; Zhang, Y.; Murphy,
C.B.; Angell, S.E.; Parker, M.F.L.; Flynn, B.R.; Jones Jr.,
W.E. Coord. Chem. Rev. 2009, 253, 410–422. (g) Zheng,
W.; He, L. J. Am. Chem. Soc. 2009, 131, 3432–3433. (h)
Yao, Z.; Feng, X.; Li, C.; Shi, G. Chem. Commun. 2009,
5886–5888.