Synthesis and properties of a novel through-space conjugated polymer with [2.2] paracyclophane and ferrocene in the main chain

Article abstract of DOI:10.1021/ma030464s

The novel conjugated polymer (12) which has [2.2]paracyclophane and ferrocene units in the polymer backbone was synthesized by palladium-catalyzed polycondensation of the monomer (10) with diiodoferrocene (11). The obtained polymer (12) was soluble in com

Full text of DOI:10.1021/ma030464s

Macromolecules 2003, 36, 9319-9324
9319
Synthesis and Properties of a Novel Through-Space Conjugated Polymer
with [2.2]Paracyclophane and Ferrocene in the Main Chain
Ya su h ir o Mor isa k i a n d Yosh ik i Ch u jo*
Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura,
Nishikyo-ku, Kyoto 615-8510, J apan
Received September 3, 2003; Revised Manuscript Received October 21, 2003
ABSTRACT: The novel conjugated polymer (12) which has [2.2]paracyclophane and ferrocene units in
the polymer backbone was synthesized by palladium-catalyzed polycondensation of the monomer (10)
with diiodoferrocene (11). The obtained polymer (12) was soluble in common organic solvents, and the
1
structure of 12 was confirmed by H NMR, 13C NMR, and FT-IR. The polymer showed delocalization of
the π-electron via the through-space of the [2.2]paracyclophane moiety. The [2.2]paracyclophane unit
was more effective for the delocalization of the π-electron than the ferrocene unit. The cyclic voltammetry
measurement of 12 showed a broad oxidation potential reversibly with a Epa value of 0.62 V. The
electrochemical oxidation was diffusion-controlled by the linear dependence of the oxidative peak currents
(I) on the square root of the scan rate (υ1/2), and the diffusion coefficient (D) of the electroactive substance
was about 5.5 × 10-7 (cm2/s). On iodine doping under ambient conditions, the polymer (12) showed a
maximum conductivity of 1.6 × 10-4 S/cm.
Ch a r t 1
In tr od u ction
Over the past decade, a great deal of interest has
arisen in the synthesis of novel conjugated polymers1
as a result of their intriguing properties, including
electrical conductivity,2 electroluminescence,3 liquid
crystallinity,4 third-order nonlinear optical properties,5
and chemical sensing.6 The most prominent example
concerns poly(p-phenylenevinylene)s, PPVs, which have
led to the development of polymer-based light-emitting
diodes (LEDs) used for displays and other purposes
since the first report on PPVs in 1990,7 and poly(p-
phenyleneethynylene)s, PPEs,8 which are a promising
candidate for the molecular wire used as an active
component in polymer-based electronic and photonic
devices. One of current research interests in conjugated
polymers including PPVs and PPEs focuses on tuning
their spectral and electrical properties. For this purpose,
a number of aromatic compounds have been incorpo-
rated with the conjugated polymer backbone, and the
physical properties of these compounds have been
investigated in detail.
Cyclophane, especially [2.2]paracyclophane, is a very
attractive molecule as an aromatic building block lead-
ing to the construction of a π-conjugated polymer.9 To
date, many cyclophane compounds have been prepared,
and their reactivity and physical properties have been
investigated in detail due to their characteristic interac-
tions between the two cofacial π-electron systems.9,10
Recently, we reported the first preparation and the
physical properties of novel π-conjugated polymers
(Chart 1)11 using cyclophane derivatives as the key
monomer. We found that the obtained polymers showed
an extension of π-delocalization via the through-space
with π-π stacking according to the UV-vis absorption
spectra and that they also exhibited an intense lumi-
nescence in solution.
tems plays an important role. From this standpoint,
Mizogami and Yoshimura reported the first synthesis
of polymetacyclophane (Chart 1) by polycondensation
reaction of an oxidative dimer of 8,16-dihydroxy[2.2]-
metacyclophane, and this polymer exhibited a conduc-
tivity of 0.25 S/cm by doping with H2SO4 vapor.12
Recently, oligothiophene-substituted [2.2]paracyclo-
phane and thiophene-containing [2.2]paracyclophane
polymers were synthesized, and their redox activities
were investigated by cyclic voltammetry analysis.13,14
Ferrocene derivatives and polymers, like those of
thiophene, are also electroactive and show semiconduc-
tive behavior.15 There are a number of articles dealing
with the synthesis of ferrocene-containing polymers.15b
In view of the interesting structure and the electronic
effect, it is fascinating to incorporate a sandwich frame-
work of ferrocene into the [2.2]paracyclophane-contain-
ing π-conjugated polymer.
In this study, we present the synthesis of the novel
through-space π-conjugated polymer with alternating
[2.2]paracyclophane and ferrocene units in the main
chain based on PPE, and we discuss the optical proper-
ties as well as the electrochemical behaviors of the
obtained polymer.
On the other hand, charge transfer is essential to
expression of conductivity and electroluminescence, in
which charge hopping between the π-conjugated sys-
Resu lts a n d Discu ssion
We synthesized the monomer (10), which has a
didodecyloxy-substituted phenylene spacer, because the
* To whom correspondence should be addressed. E-mail:
chujo@chujo.synchem.kyoto-u.ac.jp.
10.1021/ma030464s CCC: $25.00 © 2003 American Chemical Society
Published on Web 11/20/2003

9320 Morisaki and Chujo
Macromolecules, Vol. 36, No. 25, 2003
Sch em e 1
Sch em e 2
F igu r e 1. 1H NMR spectrum of the polymer (12) in CDCl3.
long alkoxy chain provides good solubility for the long
and rigid π-conjugated polymer. The synthetic route is
shown in Scheme 1. The synthesis of 4,16-diethynyl-
[2.2]paracyclophane (4) was started from commercially
available [2.2]paracyclophane (1). The iron-catalyzed
electrophilic dibromination of 1 and recrystallization
afforded only pseudo-p-dibromo[2.2]paracyclophane (2)
in 25% isolated yield due to highly poor solubility.16 The
PdCl2(PPh3)2/CuI-catalyzed cross-coupling17 of 2 and
trimethylsilylacetylene provided 3 (71%), which was
then converted to compound 4 by Bun4NF-promoted
desilylation in 90% yield. 4-Iodo-2,5-didodecyloxy-1-
[(trimethylsilyl)ethynyl]benzene (8) was prepared in a
three-step reaction from hydroquinone (5), as follows:
dialkylation of 5, diiodination of 6, followed by the
treatment of 7 with trimethylsilylacetylene in the
presence of the Pd/Cu catalyst. Due to the fact that 2,5-
didodecyloxy-1,4-diiodobenzene (7) showed a high reac-
tivity for palladium-catalyzed coupling reaction, both
2,5-didocyloxy-1,4-[bis(trimethylsilyl)ethynyl]benzene and
starting compound (7) were obtained along with 8.
Consequently, pure 8 was isolated in 11% yield by
column chromatography. Sonogashira coupling reaction
of 4 with 8 and, finally, deprotection of the trimethylsilyl
group of 9 gave the desired monomer (10) in 36% yield.
1,1′-Diiodoferrocene (11) was prepared according to the
published procedure.18
of 10 with 11 in the presence of a catalytic amount of
PdCl2(PPh3)2/PPh3/CuI for 48 h under a nitrogen atmos-
phere after purification. The polymer (12) was soluble
in common organic solvents such as THF, CH2Cl2,
CHCl3, and toluene. The polymer (12) could be processed
into a self-standing film, and it was thermally stable in
solution and in the solid state. The molecular weight
measurements were performed by gel permeation chro-
matography (GPC) in a CHCl3 eluent using a calibration
curve of polystyrene standards, and the polymer (12)
was shown to have a number-average molecular weight
(Mn) of 24 500, which corresponds to a degree of polym-
erization of about 18, with a Mw/Mn of 2.7.
1
This polymer was characterized by the H NMR, 13C
1
NMR, and IR spectra. In the H NMR spectrum of 12
in CDCl3 (Figure 1), the peak corresponding to the
terminal alkyne protons at 3.0 ppm of the monomer (10)
disappeared. The signals of the dodecyloxy side chains
were dominating in the region 0.80-1.8 ppm, and the
bridged methylene protons of [2.2]paracyclophane units
appeared at 2.8-3.8 ppm. The methylene groups adja-
cent to the oxygen were found to be 4.0 ppm. The
incorporated ferrocene protons appeared at 4.2 and 4.4
ppm, respectively. The signals of the aromatic protons
were between 6.5 and 7.5 ppm. In the 13C NMR
spectrum of the polymer (12), typical signals for acety-
lenic carbons were dominant in the region 83-95 ppm.
The acetylenic moieties were also characterized by the
IR spectrum, and a weak stretching vibration mode of
The procedure for the synthesis of the polymer (12)
was carried out as follows (Scheme 2). The orange
powder (12) was obtained in 93% yield by the treatment

Macromolecules, Vol. 36, No. 25, 2003
Novel Through-Space Conjugated Polymer 9321
Sch em e 3
a carbon-carbon triple bond was observed at around
2200 cm-1
.
The UV-vis absorption spectrum of the polymer (12)
was recorded in dilute CHCl3 at room temperature, as
shown in Figure 2. In the UV-vis absorption spectrum,
absorption maxima at 306 nm (ꢀ ) 27 800, based on the
repeating unit) and 376 nm (ꢀ ) 37 000, based on the
repeating unit), which were ascribed to the π-π*
transition of the conjugated polymer backbone, were
observed. The band gap energy of 12, estimated from
the absorption edge of the UV-vis spectrum, was about
2.10 eV.19 The spectrum of polymer 12 exhibited a blue-
shift of about 10 nm in comparison with that of polymer
13 (λmax ) 384 nm,11a Chart 2), indicating that a [2.2]-
paracyclophane unit is more effective for the delocal-
ization of the π-electron via the through-space than the
ferrocene unit. On the other hand, the model compound
(17) was prepared. The synthetic procedure is outlined
in Scheme 3, and the UV-vis absorption spectrum is
also shown in Figure 2. The UV-vis spectrum of 17 in
CHCl3 solution was similar to that of polymer 12, with
the absorption maxima at 297 and 363 nm, respectively.
This result indicates the extension of π-delocalization
length via the through-space of the two facing benzene
rings. Furthermore, 17 showed the d-d transition band
in the ferrocene moiety at around 450 nm, while 12
exhibited the broadened π-π* transition band which
covered the d-d band.
F igu r e 2. UV-vis spectra of the polymer (12) and the model
compound (17) in CHCl3 solution at room temperature.
Ch a r t 2
The fluorescence emission was investigated in dilute
CHCl3 solution (1.0 × 10-5 mol/L) at room temperature
by the excitation wavelength at 365 nm. The polymer
(12) gave a highly weak fluorescence with a peak
maximum at about 475 nm in the visible bluish green
region. The fluorescence quantum efficiency in solution
was measured relative to that of 9-anthracenecarboxylic
acid in CH2Cl2 as a standard, and the value was 0.04.20
To evaluate the electrochemical behavior of the novel
polymer examined herein, the cyclic voltammetry mea-
surement of 12 was carried out in CH2Cl2 solution
containing Bu4NPF6 (0.10 M) as a supporting electro-
lyte, with a platinum working electrode, a platinum wire
counter electrode, and a Ag/AgCl reference electrode.
Consequently, the reversible cyclic voltammogram was
obtained with a scan rate of 100 mV/s, and one broad
oxidation peak was found to be 0.62 V vs Ag/Ag+ (Figure
3). The model compound (17) had a relatively sharp
oxidation peak at 0.58 V (Figure 3, inset). These
oxidative waves could be attributed to the typical
formation of the ferrocenium corresponding to the Fe-
(II)/Fe(III) and Fe(III)/Fe(II) systems. Communication
between phenyleneethynylene groups including a fer-
rocene as a core, via the through-space of two cofacial
benzenes in [2.2]paracyclophane, causes the single
broad oxidation peak,13c although each redox active
ferrocene unit is spaced widely. Figure 4 shows the
cyclic voltammetric responses of 12 at various scan rates
from 50 to 1000 mV/s. The height of the current peaks
increased as the scan rate increased, and the oxidation
potentials were independent of the scan rate. As shown
in Figure 5, the oxidation waves were diffusion-
controlled by the linear dependence of the oxidative
peak currents (I/µA) on the square root of the scan rate
(υ1/2/V1/2 s-1/2), and they demonstrated the zero intercept,
which indicates the diffusion coefficient (D) of the
electroactive substance is about 5.5 × 10-7 (cm2/s).21 In
addition, D of the model compound (17) was 2.53 × 10-5
(cm2/s), which is larger than that of the polymer, due
to the smaller molecular size and weight. Similar results
were reported in detail by Yamamoto and co-workers
using PPE-type conjugated polymers having a ferrocene
unit in the main chain.22

9322 Morisaki and Chujo
Macromolecules, Vol. 36, No. 25, 2003
tivity of 1.6 × 10-4 S/cm. Before doping, 12 showed a
conductivity of ∼10-8, at least 4 orders of magnitude
greater than that of the undoped state. On the other
hand, the conductivity of polymetacyclophane was found
to be 0.25 S/cm by doping with H2SO4.12 The lower
conductivity of 12 seems to be the reason there are not
many electroactive ferrocene units in the polymer
backbone, while all components are doped in polymeta-
cyclophane.
In summary, a novel π-conjugated polymer (12) hav-
ing ferrocene and [2.2]paracyclophane units in the main
chain was designed, synthesized, and characterized.
π-Conjugation of 12 was expanded by way of the
through-space, and the [2.2]paracyclophane moiety was
found to contribute more effectively than the ferrocene
unit to the delocalization of the π-electron according to
the UV-vis absorption analysis. Cyclic voltammetry of
polymer 12 showed a single and reversible oxidative
wave at 0.62 V derived from the Fe(II)/Fe(III) and Fe-
(III)/Fe(II) systems. The electrochemical oxidation was
diffusion-controlled by the linear dependence of the
oxidative peak currents (I) on the square root of the scan
rate (υ1/2), and the diffusion coefficient (D) was 5.5 ×
10-7 (cm2/s), as estimated by a υ1/2-I plot. On iodine
doping under ambient conditions, the polymer (12)
showed a maximum conductivity of 1.6 × 10-4 S/cm. The
investigated polymers showed thermal stability and
good film formation, and they are therefore considered
promising candidates for use in electronic devices.
Further studies on the preparation of cyclophane poly-
mers containing organometallic moieties, and their
application as conductive materials and their use in
nonlinear optical devices, are now in progress.
F igu r e 3. Cyclic voltammogram of the polymer (12) in CH2-
Cl2 containing Bu4NPF6 as a supporting electrolyte using a
Pt electrode (vs Ag/Ag+) at a scan rate of 100 mV/s. First and
second cycles are shown. The inset shows the cyclic voltam-
mogram of 17 in CH2Cl2 containing Bu4NPF6 (vs Ag/Ag+) at a
scan rate of 100 mV/s.
Exp er im en ta l Section
Gen er a l. 1H and 13C NMR spectra were recorded on a J EOL
J NM-EX270 instrument at 270 and 67.5 MHz, respectively.
Samples were analyzed in CDCl3, and the chemical shift values
were expressed relative to Me4Si as an internal standard. IR
spectra were obtained on a Perkin-Elmer 1600 spectrometer.
UV-vis spectra were obtained on a J ASCO V-530 spectropho-
tometer, and samples were analyzed in CHCl3 at room tem-
perature. Fluorescence emission spectra were recorded on a
Perkin-Elmer LS50B luminescence spectrometer, and samples
were analyzed in CHCl3 at room temperature. Gel permeation
chromatography was carried out on a TOSOH UV-8011 and
RI-8000 (Shodex K-803L column) using CHCl3 as an eluent
after calibration with standard polystyrene. Low-resolution
mass spectra (LRMS) and high-resolution mass spectra (HRMS)
were obtained on a J EOL J MS-SX102A spectrometer. Analyti-
cal thin-layer chromatography (TLC) was performed with silica
gel 60 Merck F254 plates. Column chromatography was per-
formed with Wakogel C-300 silica gel. Elemental analysis was
performed at the Microanalytical Center of Kyoto University.
Cyclic voltammetry was carried out using a BAS CV-50W
voltammetric analyzer with a 0.10 M CH2Cl2 solution contain-
ing Bu4NPF6 as an electrolyte, a platinum working electrode,
a platinum wire counter electrode, and a Ag/AgCl reference
electrode. Electrical conductivity was measured at room tem-
perature with a two-probe technique using a Keithley 2400
source meter, after doping with iodine vapors for 24 h under
nitrogen.
F igu r e 4. Cyclic voltammogram of the polymer (12) in CH2-
Cl2 containing Bu4NPF6 as a supporting electrolyte using a
Pt electrode (vs Ag/Ag+) at scan rates from 50 to 1000 mV/s.
Ma ter ia ls. THF was distilled from sodium benzophenone
ketyl. NEt3 was distilled from KOH. CH2Cl2 was distilled from
CaCl2. Bu4NPF6 was recrystallized from EtOH. [2.2]Paracy-
clophane (1), hydroquinone (5), trimethylsilylacetylene, phe-
nylacetylene, Bun4NF (1.0 M in THF), dodecanol, PdCl2(PPh3)2,
CuI, PPh3, K2CO3, KI, I2, and KIO4 were obtained commercially
and used without further purification. 4,16-Dibromo[2.2]-
paracyclophane (2),16 1,4-didodecyloxybenzene (6),23 2,5-di-
dodecyloxy-1,4-diiodobenzene (7),23 1,1′-diiodoforrocene (11),18
F igu r e 5. Plot of I (I ) anodic peak current) vs υ1/2 (υ ) scan
rate) for the titled polymer (12).
The electrical conductivity measurement of the poly-
mer (12) by oxidatively doping with iodine vapors for
24 h under a nitrogen atmosphere exhibited a conduc-

Macromolecules, Vol. 36, No. 25, 2003
Novel Through-Space Conjugated Polymer 9323
24
and Pd(PPh3)4 were prepared as described in the literature.
26.2, 26.6, 29.1, 29.3, 29.4, 29.5, 29.6 (overlapping signals),
31.9, 32.2, 33.8, 34.1, 69.5, 69.6, 89.2, 95.2, 99.5, 101.3, 100.8,
113.4, 114.5, 116.5, 117.3, 124.8, 130.6, 133.2, 137.1, 139.6,
142.2, 153.5, 154.1. IR (KBr): 2155 cm-1. LRMS (EI) m/z
(relative intensity) ) 1338 (M+, 29), 154 (100). HRMS (FAB):
calcd for C90H136O4Si2, 1336.9977; found, 1336.9973. Anal.
Calcd for C90H136O4Si2: C, 80.78; H, 10.24. Found: C, 80.56;
H, 10.00.
All reactions were performed under a nitrogen atmosphere
using standard Schlenk techniques.
4,16-Bis(tr im eth ylsilyleth yn yl)[2.2]par acycloph an e (3).
4,16-Dibromo[2.2]paracyclophane (2) (3.5 g, 9.7 mmol), tri-
methylsilylacetylene (10 mL), PdCl2(PPh3)2 (0.70 g, 1.0 mmol),
PPh3 (0.52 g, 2.0 mmol), and CuI (0.20 g, 1.0 mmol) were
dissolved in 70 mL of THF-NEt3 (v/v ) 5:2). The solution was
stirred at 75 °C for 2 days under a nitrogen atmosphere.
Precipitated ammonium salts were filtered off, and the filtrate
was evaporated under vacuum. The residue was subjected to
column chromatography on SiO2 with hexane-CHCl3 (v/v )
2:1, Rf ) 0.15) as an eluent to givecompound 3 (2.7 g, 6.8 mmol,
4,16-Bis[(2,5-d id od ecyloxy-4-eth yn ylp h en yl)eth yn yl]-
[2.2]p a r a cyclop h a n e (10). To a solution of 9 (1.9 g, 1.4 mmol)
in 20 mL of THF was added Bun4NF (0.50 mL, 1.0 M solution
in THF). The reaction mixture was stirred at room tempera-
ture for 24 h under a nitrogen atmosphere. The solution was
evaporated under vacuum, and the residue was subjected to
column chromatography on SiO2 with hexane-CHCl3 (v/v )
2:1, Rf ) 0.55) as an eluent to give compound 10 (0.61 g, 0.51
1
81%) as a white powder. H NMR (CDCl3, 270 MHz): δ 0.31
(s, 18H), 2.80 (m, 2H), 2.97 (m, 2H), 3.14 (m, 2H), 3.57 (m,
2H), 6.44 (d, J ) 7.8 Hz, 2H), 6.49 (s, 2H), 7.98 (d, J ) 7.8 Hz,
2H). 13C NMR (CDCl3, 67.5 MHz): δ 0.13, 33.5, 34.0, 97.5,
105.8, 124.6, 130.1, 133.0, 137.4, 139.3, 142.6. IR (Nujol): 2146
cm-1. LRMS (EI) m/z (relative intensity) ) 400 (M+, 75), 200
(100), 185 (70). Anal. Calcd for C26H32Si2: C, 77.93; H, 8.05.
Found: C, 77.82; H, 8.02.
1
mmol, 36%) as a yellow powder. H NMR (CDCl3, 270 MHz):
δ 0.87 (t, J ) 4.6 Hz, 12H), 1.25 (m, 64H), 1.50 (m, 8H), 1.88
(m, 8H), 2.93 (m, 4H), 3.30 (m, 2H), 3.36 (s, 2H), 3.72 (m, 2H),
4.05 (m, 4H), 4.05 (t, J ) 4.3 Hz, 4H), 6.51 (d, J ) 7.5 Hz,
2H), 6.60 (s, 2H), 7.03 (s, 2H), 7.10 (d, J ) 7.5 Hz, 2H). 13C
NMR (CDCl3, 67.5 MHz): δ 14.1, 22.7, 25.9, 26.2, 29.2, 29.3,
29.5, 29.6 (overlapping signals), 31.9, 33.8, 34.1, 69.3, 69.7,
80.1, 82.1, 89.1, 95.3, 112.3, 114.9, 117.0, 124.8, 130.6, 133.2,
137.2, 139.6, 142.2, 142.3, 153.4, 154.1. IR (KBr): 3287, 2107
cm-1. LRMS (EI) m/z (relative intensity) ) 1194 (M+, 8), 154
(100). HRMS (FAB): calcd for C84H120O4, 1192.9187; found,
1192.9199. Anal. Calcd for C84H120O4: C, 84.51; H, 10.13.
Found: C, 84.04; H, 10.09.
4,16-Dieth yn yl[2.2]p a r a cyclop h a n e (4). To a solution of
3 (2.0 g, 5.0 mmol) in 50 mL of THF was added Bun4NF (10
mL, 1.0 M solution in THF). The reaction mixture was stirred
at room temperature for 20 h under a nitrogen atmosphere.
The solution was evaporated under vacuum, and the residue
was subjected to column chromatography on SiO2 with hex-
ane-CHCl3 (v/v ) 2:1, Rf ) 0.55) as an eluent to give
compound 4 (1.1 g, 4.5 mmol, 90%) as a white powder. 1H NMR
(CDCl3, 270 MHz): δ 2.92 (m, 4H), 3.19 (m, 2H), 3.27 (s, 2H),
3.59 (m, 2H), 6.44 (d, J ) 7.0 Hz, 2H), 6.56 (s, 2H), 7.00 (d, J
) 7.0 Hz, 2H). 13C NMR (CDCl3, 67.5 MHz): δ 33.7, 33.8, 80.2,
83.9, 123.5, 130.6, 133.2, 137.8, 139.5, 142.6. IR (KBr): 3298,
2098 cm-1. LRMS (EI) m/z (relative intensity) ) 256 (M+, 88),
241 (35), 128 (100). Anal. Calcd for C20H16: C, 93.71; H, 6.29.
Found: C, 93.45; H, 6.26.
4-Iodo-2,5-didodecyloxy-1-(ph en yleth yn yl)ben zen e (14).
Compound 7 (7.0 g, 10 mmol), phenylacetylene (1.1 g, 11
mmol), PdCl2(PPh3)2 (0.36 g, 0.50 mmol), and CuI (0.10 g, 0.50
mmol) were dissolved in 80 mL of THF-Et3N (v/v ) 3:1). The
solution was stirred at 40 °C for 24 h under a nitrogen
atmosphere. Precipitated ammonium salts were filtered off,
and the filtrate was evaporated under vacuum. The residue
was subjected to column chromatography on SiO2 with hex-
ane-CHCl3 (v/v ) 2:1, Rf ) 0.50) as an eluent to give
compound 14 (2.6 g, 3.8 mmol, 38%) as a white solid. Didode-
cyloxy-1,4-diiodobenzene (7) (Rf ) 0.95) and 2,5-diiodo-1,4-bis-
(phenylethynyl)benzene (Rf ) 0.20) were removed by column
4-Iod o-2,5-d id od ecyloxy-1-(tr im eth ylsilyleth yn yl)ben -
zen e (8). 2,5-Didodecyloxy-1,4-diiodobenzene (7) (21 g, 30
mmol), trimethylsilylacetylene (3.5 g, 35 mmol), PdCl2(PPh3)2
(0.70 g, 1.0 mmol), and CuI (0.20 g, 1.0 mmol) were dissolved
in 120 mL of THF-Et3N (v/v ) 7:5). The solution was stirred
at room temperature for 24 h under a nitrogen atmosphere.
Precipitated ammonium salts were filtered off, and the filtrate
was evaporated under vacuum. The residue was subjected to
column chromatography on SiO2 with hexane-CHCl3 (v/v )
9:1, Rf ) 0.60) as an eluent to give compound 8 (2.3 g, 3.5
mmol, 12%) as a pale yellow powder. Didodecyloxy-1,4-diiodo-
benzene (7) (Rf ) 0.95) and 2,5-diiodo-1,4-bis(trimethylsilyl-
ethynyl)benzene (Rf ) 0.33) were removed by column chro-
1
chromatography. H NMR (CDCl3, 270 MHz): δ 0.88 (t, J )
6.4 Hz, 6H), 1.26-1.32 (m, 32H), 1.52 (m, 4H), 1.82 (m, 4H),
3.95 (t, J ) 6.8 Hz, 2H), 3.97 (t, J ) 6.8 Hz, 2H), 6.90 (s, 1H),
7.29 (s, 1H), 7.32 (m, 3H), 7.53 (m, 2H). 13C NMR (CDCl3, 67.5
MHz): δ 14.1, 22.7, 26.0, 29.1, 29.3, 29.4, 29.6 (overlapping
signals), 31.9, 69.8, 70.0, 85.5, 87.4, 93.9, 94.1, 113.5, 115.8,
123.4, 123.7, 128.2, 131.5, 149.3, 151.7, 154.3. IR (Nujol): 2212
cm-1. LRMS (EI) m/z (relative intensity) ) 672 (M+, 96), 336
(100), 210 (81). HRMS (FAB): calcd for C38H57IO2, 672.3403;
found, 672.3401. Anal. Calcd for C38H57IO2: C, 67.84; H, 8.54.
Found: C, 68.12; H, 8.52.
1
matography. H NMR (CDCl3, 270 MHz): δ 0.26 (s, 9H), 0.88
(t, J ) 4.3 Hz, 6H), 1.26-1.31 (m, 32H), 1.51 (m, 4H), 1.79 (m,
4H), 3.93 (t, J ) 4.0 Hz, 4H), 6.83 (s, 1H), 7.25 (s, 1H). 13C
NMR (CDCl3, 67.5 MHz): δ 0.06, 14.1, 22.7, 26.0, 26.1, 29.2,
29.3, 29.4, 29.5, 29.6 (overlapping signals), 31.9, 69.8, 70.1,
87.9, 99.4, 100.8, 113.4, 116.3, 123.9, 151.7, 154.9. IR (KBr):
2162 cm-1. LRMS (EI) m/z (relative intensity) ) 668 (M+, 76),
154 (100). HRMS (FAB): calcd for C35H61IO2Si, 668.3486;
found, 668.3484. Anal. Calcd for C35H61IO2Si: C, 62.85; H, 9.19.
Found: C, 63.10; H, 8.94.
2,5-Did od ecyloxy-1-(tr im eth ylsilyleth yn yl)-4-(p h en yl-
eth yn yl)ben zen e (15). Compound 14 (2.6 g, 3.8 mmol),
trimethylsilylacetylene (3.0 mL), PdCl2(PPh3)2 (0.14 g, 0.20
mmol), PPh3 (0.10 g, 4.0 mmol), and CuI (0.040 g, 0.20 mmol)
were dissolved in 35 mL of THF-NEt3 (v/v ) 5:2). The solution
was stirred at 40 °C for 24 h under a nitrogen atmosphere.
Precipitated ammonium salts were filtered off, and the filtrate
was evaporated under vacuum. The residue was subjected to
column chromatography on SiO2 with hexane-CHCl3 (v/v )
2:1, Rf ) 0.48) as an eluent to give compound 15 (1.0 g, 1.6
mmol, 42%) as a pale yellow solid. 1H NMR (CDCl3, 270
MHz): δ 0.27 (s, 9H), 0.88 (t, J ) 6.4 Hz, 6H), 1.25 (m, 32H),
1.52 (m, 4H), 1.81 (m, 4H), 3.98 (t, J ) 6.4 Hz, 2H), 3.99 (t, J
) 6.8 Hz, 2H), 6.94 (s, 1H), 6.96 (s, 1H), 7.33 (m, 3H), 7.52 (m,
2H). 13C NMR (CDCl3, 67.5 MHz): δ -0.05, 14.1, 22.7, 26.0,
29.3, 29.4, 29.6 (overlapping signals), 31.9, 69.4, 69.5, 85.8,
94.8, 99.9, 101.1, 113.5, 114.2, 116.7, 117.1, 123.4, 128.2, 131.5,
131.6, 153.4, 154.1. IR (Nujol): 2154 cm-1. LRMS (EI) m/z
(relative intensity) ) 642 (M+, 100), 291 (83). HRMS (FAB):
calcd for C43H66O2Si, 642.4832; found, 642.4835. Anal. Calcd
for C43H66O2Si: C, 80.31; H, 10.34. Found: C, 80.01; H, 10.53.
2,5-Did od e cyloxy-1-e t h yn yl-4-(p h e n yle t h yn yl)b e n -
zen e (16). To a solution of 15 (0.90 g, 1.4 mmol) in 25 mL of
4,16-Bis{[2,5-d id od ecyloxy-4-(t r im et h ylsilylet h yn yl)-
ph en yl]eth yn yl}[2.2]par acycloph an e (9). Compound 4 (0.39
g, 1.5 mmol), 8 (2.0 g, 3.0 mmol), PdCl2(PPh3)2 (0.070 g, 0.10
mmol), and CuI (0.020 g, 0.10 mmol) were dissolved in 8 mL
of THF-Et3N (v/v ) 5:3). The solution was stirred at 50 °C
for 24 h. Precipitated ammonium salts were filtered off, and
the filtrate was evaporated under vacuum. The residue was
subjected to column chromatography on SiO2 with hexane-
CHCl3 (v/v ) 1:1, Rf ) 0.67) as an eluent to give compound 9
(2.0 g, 1.5 mmol, 99%) as a white powder. 1H NMR (CDCl3,
270 MHz): δ 0.25 (s, 18H), 0.86 (t, J ) 4.7 Hz, 6H), 0.87 (t, J
) 4.7 Hz, 6H), 1.25-1.36 (m, 64H), 1.53 (m, 8H), 1.81 (m, 4H),
1.91 (m, 4H), 2.89 (m, 2H), 3.00 (m, 2H), 3.30 (m, 2H), 3.76
(m, 2H), 4.03 (t, J ) 4.3 Hz, 4H), 4.05 (t, J ) 4.3 Hz, 4H), 6.49
(d, J ) 5.4 Hz, 2H), 6.59 (s, 2H), 6.98 (s, 2H), 7.08 (d, J ) 5.4
Hz, 2H). 13C NMR (CDCl3, 67.5 MHz): δ 0.00, 14.1, 22.7, 26.1,

9324 Morisaki and Chujo
Macromolecules, Vol. 36, No. 25, 2003
THF was added Bun4NF (0.50 mL, 1.0 M solution in THF).
The reaction mixture was stirred at room temperature for 16
h under a nitrogen atmosphere. The solution was evaporated
under vacuum, and the residue was washed with MeOH to
give pure 16 (0.73 g, 1.3 mmol, 92%) as a pale yellow solid. 1H
NMR (CDCl3, 270 MHz): δ 0.88 (t, J ) 6.4 Hz, 6H), 1.25 (m,
32H), 1.51 (m, 4H), 1.82 (m, 4H), 3.35 (s, 1H), 3.99 (t, J ) 6.0
Hz, 2H), 4.01 (t, J ) 6.4 Hz, 2H), 6.98 (s, 1H), 6.99 (s, 1H),
7.34 (m, 3H), 7.53 (m, 2H). 13C NMR (CDCl3, 67.5 MHz): δ
14.1, 22.7, 25.9, 26.0, 29.1, 29.3, 29.4, 29.6 (overlapping
signals), 31.9, 69.4, 69.5, 80.0, 82.2, 85.7, 94.9, 112.4, 114.6,
116.7, 117.7, 123.3, 128.3, 131.5, 131.6, 153.4, 154.1. IR
(Nujol): 3280, 2106 cm-1. LRMS (EI) m/z (relative intensity)
) 570 (M+, 100), 234 (82). HRMS (FAB): calcd for C40H58O2,
570.4437; found, 570.4440. Anal. Calcd for C40H58O2: C, 84.15;
H, 10.24. Found: C, 84.04; H, 10.33.
(5) See, for example: (a) Nonlinear Optical Effects in Organic
Polymers; Messier, J ., Kajzar, F., Prasad, P. N., Ulrich, D.
R., Eds.; Kluwer Academic Publishers: Dordrecht, 1989. (b)
Introduction to Nonlinear Optical Effects in Molecules and
Polymers; Prasad, P. N., Williams, D. J ., Eds.; Wiley: New
York, 1990. (c) Materials for Nonlinear Optics; Marder, S.
R., Sohn, J . E., Stucky, G. D., Eds.; ACS Symposium Series
455; American Chemical Society: Washington, DC, 1991. (d)
Molecular Nonlinear Optics: Materials, Physics, and Devices;
Zyss, J ., Ed.; Academic Press: Boston, MA 1994. (e) Bredas,
J . L.; Adant, C.; Tackx, P.; Persoons, A. Chem. Rev. 1994,
94, 243.
(6) For a recent review, see: McQuade, D. T.; Pullen, A. E.;
Swager, T. M. Chem. Rev. 2000, 100, 2537.
(7) Burroughes, J . H.; Bradley, D. D. C.; Brown, A. R.; Marks,
R. N.; Mackay, K.; Friend, R. H.; Burns, P. L.; Holmes, A. B.
Nature (London) 1990, 347, 539.
(8) For a recent review, see: Bunz, U. H. F. Chem. Rev. 2000,
100, 1605.
(9) For recent reviews, see: (a) Vo¨gtle, F. In Cyclophane Chem-
istry; Wiley & Sons: New York, 1993. (b) Shultz, J .; Vo¨gtle,
F. Top. Curr. Chem. 1994, 172, 42.
(10) For recent articles, see: (a) Bazan, G. C.; Oldham, W. J ., J r.;
Lachicotte, R. J .; Tretiak, S.; Chernyak, V.; Mukamel, S. J .
Am. Chem. Soc. 1998, 120, 9188. (b) Wang, S.; Bazan, G. C.;
Tretiak, S.; Mukamel, S. J . Am. Chem. Soc. 2000, 122, 1289.
(c) Zyss, J .; Ledoux, I.; Volkov, S.; Chernyak, V.; Mukamel,
S.; Bartholomew, G. P.; Bazan, G. C. J . Am. Chem. Soc. 2000,
122, 11956. (d) Bartholomew, G. P.; Bazan, G. C. J . Am.
Chem. Soc. 2002, 124, 5183.
1,1′-Bis{[2,5-d id od ecyloxy-4-(p h en ylet h yn yl)p h en yl]-
eth yn yl}fer r ocen e (17). Compound 11 (0.22 g, 0.50 mmol),
16 (0.57 g, 1.0 mmol), Pd(PPh3)4 (0.12 g, 0.10 mmol), and CuI
(0.020 g, 0.10 mmol) were dissolved in 7 mL of THF-NEt3
(v/v ) 5:2). The solution was stirred at 50 °C for 48 h under a
nitrogen atmosphere. Precipitated ammonium salts were
filtered off, and the filtrate was evaporated under vacuum. The
residue was subjected to column chromatography on SiO2 with
hexane-CHCl3 (v/v ) 2:1, Rf ) 0.27) as an eluent to give
compound 17 (0.46 g, 0.34 mmol, 67% based on 11) as a red
1
solid. H NMR (CDCl3, 270 MHz): δ 0.88 (m, 12H), 1.25 (m,
64H), 1.54 (m, 8H), 1.83 (m, 8H), 3.94 (t, J ) 6.2 Hz, 4H), 4.00
(t, J ) 6.2 Hz, 4H), 4.36 (s, 4H), 4.58 (s, 4H), 6.92 (s, 2H), 6.97
(s, 2H), 7.33 (m, 6H), 7.52 (m, 4H). 13C NMR (CDCl3, 67.5
MHz): δ 14.1, 22.7, 26.0, 26.1, 29.3, 29.5, 29.6 (overlapping
signals), 31.9, 66.7, 69.5, 71.5, 73.0, 82.8, 86.1, 93.0, 94.6, 113.3,
114.4, 116.6, 116.7, 123.5, 128.1, 128.3, 131.5, 153.4, 153.6.
IR (KBr): 2212 cm-1. HRMS (FAB): calcd for C90H122O4Fe,
1322.8693; found, 1322.8676.
(11) (a) Morisaki, Y.; Chujo, Y. Macromolecules 2002, 35, 587. (b)
Morisaki, Y.; Chujo, Y. Chem. Lett. 2002, 194. (c) Morisaki,
Y.; Ishida, T.; Chujo, Y. Macromolecules 2002, 35, 7872. (d)
Morisaki, Y.; Chujo, Y. Polym. Bull. (Berlin) 2002, 49, 209.
(e) Morisaki, Y.; Ishida, T.; Chujo, Y. Polym. J . 2003, 35, 501.
(f) Morisaki, Y.; Fujimura, F.; Chujo, Y. Organometallics
2003, 22, 3553.
(12) Mizogami, S.; Yoshimura, S. J . Chem. Soc., Chem. Commun.
1985, 1736.
P olym er iza tion . A typical procedure is as follows. A
mixture of 10 (119 mg, 0.10 mmol), 11 (44 mg, 0.10 mmol),
PdCl2(PPh3)2 (7.2 mg, 0.010 mmol), PPh3 (5.2 mg, 0.020 mmol),
CuI (2.0 mg, 0.010 mol), NEt3 (2.0 mL), and THF (4.0 mL)
was placed in a 50 mL Pyrex flask equipped with a magnetic
stirring bar and a reflux condenser under a nitrogen atmos-
phere. The reaction was carried out at 50 °C for 48 h with
stirring. After the reaction mixture was cooled, precipitated
ammonium salts were filtered off and washed with THF. The
filtrate was concentrated and poured into MeOH (50 mL) to
precipitate the polymer. The resulting polymer (12) was
filtered, washed with MeOH, and dried in vacuo to give 128
mg (0.093 mmol, 93%) as an orange powder. 1H NMR (CDCl3,
270 MHz): δ 0.82 (br s, 12H), 1.20 (br s, 64H), 1.49 (br s, 8H),
1.88 (m, 8H), 1.83 (m, 8H), 2.84 (br, 4H), 3.25 (br, 2H), 3.72
(m, 2H), 4.00 (br, 8H), 4.21 (br s, 4H), 4.42 (br, 4H), 6.46 (m,
2H), 6.55 (br s, 2H), 7.00 (m, 6H). 13C NMR (CDCl3, 67.5
MHz): δ 14.1, 22.7, 26.0, 26.2, 29.0, 29.4, 29.5 (overlapping
signals), 31.9, 33.8, 34.1, 69.8, 70.0, 71.2, 72.3, 74.1, 83.3, 89.4,
92.5, 95.0, 113.7, 116.2, 117.0, 124.9, 128.3, 134.1, 137.1, 139.6,
(13) (a) Collard, D. M.; Lee, B. ACS Polym. Prepr. 2000, 41 (1),
241. (b) Salhi, F.; Collard, D. M. Polym. Mater. Sci. Eng. 2002,
222. (c) Salhi, F.; Collard, D. M. Adv. Mater. 2003, 15, 81.
(14) (a) Guyard, L.; Audebert, P. Elecrochem. Commun. 2001, 3,
164. (b) Guyard, L.; Nguyen Dinh An, M.; Audebert, P. Adv.
Mater. 2001, 13, 133.
(15) (a) Togni, A., Hayashi, T., Eds. Ferrocenes: Homogeneous
Catalysis, Organic Synthesis, Materials Science; Wiley-
VCH: Weinheim, 1995. (b) Hudson, R. D. H. J . Organomet.
Chem. 2001, 637-639, 47 and pertinent references therein.
(16) (a) Reich, H. J .; Cram, D. J . J . Am. Chem. Soc. 1969, 91, 3527.
(b) Izuoka, A.; Murata, S.; Sigawara, T.; Iwamura, H. J . Am.
Chem. Soc. 1987, 109, 2631.
(17) (a) Dieck, H. A.; Heck, R. F. J . Organomet. Chem. 1975, 93,
259. (b) Sonogashira, K.; Tohda, Y.; Hagihara, N. Tetrahedron
Lett. 1975, 16, 4467.
(18) Kovar, R. F.; Rausch, M. D.; Rosenberg, H. Organomet. Chem.
Synth. 1970/1971, 1, 173.
(19) J ohnson, E. G.; Willardson, R.; Beer, A. C. Semiconductors
and Semimetals; Academic Press: New York, 1967.
(20) The quantum efficiency (Φunk) of an unknown sample was
142.2, 153.4, 153.6. IR (film): 2200, 832 cm-1
.
calculated by the following equation: Φunk ) Φstd[AstdFunk
/
2
A
unkFstd][nD,unk/nD,std] where Astd and Aunk are the absor-
bances of the standard and unknown samples, respectively,
Fstd and Funk are the corresponding relative integrated
fluorescence intensities, and nD is the refractive index [CH2-
Cl2 (nD ) 1.424) and CHCl3 (nD ) 1.446) were used].
(21) According to the linear dependence of I vs υ1/2, the diffusion
coefficient (D) at 25 °C was estimated using the following
equation: I ) 268.6ACD1/2υ1/2 where A (cm2) is the area of
the electrode, C (mol/L) is the concentration of the electro-
chemically active species, and υ (V/s) is the sweep ratio,
respectively.
(22) (a) Yamamoto, T.; Morikita, T.; Maruyama, T.; Kubota, K.;
Katada, M. Macromolecules 1997, 30, 5390. (b) Morikita, T.;
Yamamoto, T. J . Organomet. Chem. 2001, 637-639, 809.
(23) (a) Li, H.; Powell, D. R.; Hayashi, R. K.; West, R. Macromol-
ecules 1998, 31, 52. (b) Moroni, M.; Moigne, J . L. Macromol-
ecules 1994, 27, 562.
Ack n ow led gm en t. We thank the Ogasawara Foun-
dation for Promotion of Science & Engineering and the
Kinki Invention Center for financial support.
Refer en ces a n d Notes
(1) Skothim, T. A., Elsenbaumer, R. L., Reynolds, J ., Eds.
Handbook of Conducting Polymers, 2nd ed.; Marcel Dekker:
New York, 1997.
(2) Pomerantz, M. Handbook of Conducting Polymers, 2nd ed.;
Marcel Dekker: New York, 1998.
(3) For a recent review, see: Kraft, A.; Grimsdale, A. C.; Holmes,
A. B. Angew. Chem., Int. Ed. Engl. 1998, 37, 402.
(4) (a) Nehring, J .; Amstutz, H.; Holmes, P. A.; Nevin, A. Appl.
Phys. Lett. 1987, 51, 1283. (b) Moll, A.; Siegfried, N.; Heitz,
W. Makromol. Chem., Rapid Commun. 1990, 11, 485. (c)
Witteler, H.; Lieser, G.; Wegner, G.; Schulze, M. Makromol.
Chem., Rapid Commun. 1993, 14, 471.
(24) Coulson, D. R. Inorg. Synth. 1972, 13, 121.
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