Carbazole-functionalised poly(1-phenyl-1-alkyne)s: Synthesis, light emission, and fluorescent photopatterning

Article abstract of DOI:10.1071/CH12116

Carbazole-containing 1-phenyl-1-alkynes with different spacer lengths [C₆H₅C≡C(CH₂)mCar₁(m) (m≤3, 4, 9), Car≤9-carbazolyl] were synthesised in high yields by consecutive substitution and coupling reactions of n-chloro-1-alkynes. Polymerisation of the monomers was effected by NbCl₅ and WCl6Ph4Sn catalysts, furnishing soluble polymers P1(m) with high molecular weights in high yields. All the polymers were thermally stable, commencing to lose their weights at high temperatures (<400C). Photoexcitation of their THF solutions induced strong blue light emissions with high quantum efficiencies up to 92%. Multilayer electroluminescence devices with configurations of ITO/P1(m)(:PVK)/BCP/Alq3/LiF/ Al were constructed, which gave blue light with maximum luminance and external quantum efficiency of 438cdm-2 and 0.63%. UV irradiation of a thin film of P1(4) through a mask oxidized and quenched the light emission of the exposed parts, generating a two-dimensional luminescent photopattern.

Full text of DOI:10.1071/CH12116

RESEARCH FRONT
CSIRO PUBLISHING
Aust. J. Chem. 2012, 65, 1228–1237
Full Paper
http://dx.doi.org/10.1071/CH12116
Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s:
Synthesis, Light Emission, and Fluorescent Photopatterning
A B
,
C
D
A B
,
Jacky W. Y. Lam,
Cathy K. W. Jim,
Anjun Qin, Yuping Dong, Jianzhao Liu,
A B
,
A B
,
E
Yuning Hong,
Hoi Sing Kwok,
A B C F
, , ,
and Ben Zhong Tang
A
Department of Chemistry, Institute for Advanced Study, State Key Laboratory
of Molecular Neuroscience and Institute of Molecular Functional Materials,
The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon,
Hong Kong, P. R. China.
B
The Hong Kong University of Science & Technology, Fok Ying Tung Research Institute,
Nansha, Guangzhou, P. R. China.
C
Department of Polymer Science & Engineering, Institute of Biomedical
Macromolecules, Zhejiang University, Hangzhou 310027, P. R. China.
D
College of Materials Science & Engineering, Beijing Institute of Technology,
Beijing 100081, P. R. China.
E
Center for Display Research, HKUST, Clear Water Bay, Kowloon, Hong Kong,
P. R. China.
F
Corresponding author. Email: tangbenz@ust.hk
Carbazole-containing 1-phenyl-1-alkynes with different spacer lengths [C6H5CꢀC(CH2)mCar 1(m) (m ¼ 3, 4, 9), Car ¼
9-carbazolyl] were synthesised in high yields by consecutive substitution and coupling reactions of n-chloro-1-alkynes.
Polymerisation of the monomers was effected by NbCl5– and WCl6–Ph4Sn catalysts, furnishing soluble polymers P1(m)
with high molecular weights in high yields. All the polymers were thermally stable, commencing to lose their weights at
high temperatures ($ 4008C). Photoexcitation of their THF solutions induced strong blue light emissions with high
quantum efficiencies up to 92 %. Multilayer electroluminescence devices with configurations of ITO/P1(m)(:PVK)/BCP/
Alq3/LiF/Al were constructed, which gave blue light with maximum luminance and external quantum efficiency of
438 cd mꢁ2 and 0.63 %. UV irradiation of a thin film of P1(4) through a mask oxidized and quenched the light emission of
the exposed parts, generating a two-dimensional luminescent photopattern.
Manuscript received: 24 February 2012.
Manuscript accepted: 14 April 2012.
Published online: 18 May 2012.
bearing carbazole moieties.[6] Most of the efforts, however, have
met with only little success. For example, polymerisation of
N-carbazolylacetylene catalysed by Fe(acac)3–Et3Al[6a] and
3-(N-carbazolyl)-1-propyne in the presence of Ti(OBu)4–Et3Al
and WOCl4–Ph4Sn[6b] gave onlyinsoluble polymers and/or oligo-
mers. Masuda found that WCl6 complexed with n-Bu4Sn worked
well for the polymerisation of 3-(9-carbazolyl)-1-propyne[6c] but
the resultant polymer, however, was insoluble. Even when the
spacer length in the monomer was lengthened to two or four
methylene units, no soluble polymers could be obtained. Because
many possible side reactions can be induced by the toxic
interaction between the polar nitrogen atom of carbazole and
the transition-metal catalysts, synthesis of carbazole-containing
polyacetylenes remains largely a challenge.[7] Our group has
also worked on the design and synthesis of polyacetylenes with
carbazole pendant groups. Delightfully, when the spacer length
in poly[3-(N-carbazolyl)-1-propyne] was lengthened to 3 and 9
methylene units, the polymers were readily soluble in common
Introduction
Polyacetylene is a Nobel Prize-winning macromolecule and
exhibits a high conductivity upon doping.[1,2] Its intractability
and instability, however, has greatly detracted from its potential
for high-technological applications. Replacement of one or two
of its hydrogen atoms by appropriate substituent(s) has gener-
ated mono- and disubstituted polyacetylenes that show not only
better processability and stability but also possess novel prop-
erties that are not found in the parent form. Many substituted
polyacetylenes prepared so far, however, bear nonpolar alkyl
and/or aryl groups.[3] Introduction of polar functional groups
into the polyacetylene structure would further advance poly-
acetylene research and open up a new avenue in polyacetylene-
based speciality materials.[4]
Carbazole is a well known light-emitting, photoconductive,
photorefractive, and hole-transporting material.[5] Owing to the
expectation of generating polymers with unique optoelectronic
properties, manygroupshaveattemptedtopolymerizeacetylenes
Journal compilation Ó CSIRO 2012
www.publish.csiro.au/journals/ajc

Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s
1229
Bu4NϩBrϪ
HC C(CH2)mCl
HC C(CH2)m
ϩ H
N
N
benzene/50 % KOH (aq), reflux
2(m) (m ϭ 3, 4, 9)
3(m) (m ϭ 3, 4, 9)
I
cat.
C
C(CH2)m
[ C C ]n
(CH2)m
N
Pd(PPh3)2Cl2, CuI, Et3N, rt
N
1(m) (m ϭ 3, 4, 9)
P1(m) (m ϭ 3, 4, 9)
Scheme 1. Synthesis of carbazole-containing 1-phenyl-1-alkynes and their transformation into polymers.
organic solvents.[8] We studied their light-emitting properties
and found that they emitted intense UV light upon photoexcita-
tion. The polymers were also photoconductive with photosensi-
tivity much better than poly(9-vinylcarbazole), the best-known
photoconducting vinyl polymer.[9] The carbazole-containing
polyacetylenes are thus a group of new polymers with novel
material properties and further investigation in this area should
lead to more fruitful results.
In this paper, we report the synthesis and properties of a
group of disubstituted polyacetylenes bearing carbazole appen-
dages of varying spacer lengths [P1(m); Scheme 1]. While P1(3)
and P1(9) are newly prepared, the photo- (PL) and electrolumi-
nescence (EL) of P1(4) have been briefly discussed in our
previous short review.[10] Details about its preparation and
functional properties, however, have not been presented. We
would like to give a complete discussion on these, and compare
with those of P1(3) and P1(9) in this paper.
Table 1. Polymerisation of 5-(9-carbazolyl)-1-phenyl-1-pentyne [1(3)]A
No.
Catalyst
Temp [8C]
Yield [%]
MwB
Mw/MBn
1
2
3
4
5
6
NbCl5–Ph4Sn
TaCl5–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
MoCl5–Ph4Sn
60
60
rt
4.6
Trace
8.3
16100
2.3
5800
43000
40400
1.9
2.2
3.1
60
80
60
79.3
92.8
0
ACarried out under nitrogen in toluene for 24 h; [M]0 ¼ 0.2 M, [cat.] ¼
[cocat.] ¼ 10 mM.
BDetermined by GPC in THF on the basis of a polystyrene calibration.
they were also capable of polymerising 1(3). Polymerisation
catalysed by NbCl5–Ph4Sn in toluene at 608C, however, gave a
polymer in a low yield (Table 1, no. 1). The catalytic activity of
TaCl5–Ph4Sn was even lower and no polymeric product was
isolated at all. Clearly, the catalysts are sensitive to the polar
nitrogen atom of the carbazole moiety. Disappointed by the
results, we thus checked whether there is any hope for the
monomer to be polymerised by early-transition-metal halides.
Whereas the reaction with the WCl6–Ph4Sn catalyst at room
temperature gave a low molecular weight polymer in a low
yield, the molecular weight and yield were dramatically boosted
when the temperature was raised to 608C. Further increment of
the temperature to 808C resulted in a much better result: a high
molecular weight, yellow powdery polymer was isolated in
nearly quantitative yield. In sharp contrast, MoCl5–Ph4Sn was
inert for the polymerisation.
Similar to the results of 1(3), 1(4) could be polymerised by
NbCl5–Ph4Sn albeit in a low yield, TaCl5–Ph4Sn was again
ineffective for the polymerisation (Table 2, no. 1 and 2).
Delightfully, WCl6–Ph4Sn performed well for the polymerisa-
tion at 608C, producing a polymer with a high molecular weight
in over 80 % yield. However, polymerisation carried out at 808C
gave a polymer in much lower yield and molecular weight. It
should be stressed here that the result for the polymerisation of
1(4) catalysed by WCl6–Ph4Sn is truly amazing. WCl6–Ph4Sn
had been found to initiate the polymerisation of 6-(9-
carbazolyl)-1-hexyne[6c] and 1-pheny-1-hexyne,[11d] a mono-
substituted cousin and parent form of 1(4), but none of the
resultant polymers were soluble. Polymer P1(4) prepared by the
Results and Discussion
Monomer Synthesis
We designed the molecular structures of three chromophore-
containing 1-phenyl-1-alkynes and elaborated a two-step reac-
tion route for their synthesis. We first attached carbazole to
the acetylene structure through the nitrogen atom by reaction
of n-chloro-1-alkynes with carbazole, catalysed by tetra-
butylammonium bromide (Scheme 1) The obtained products
3(m) were then further coupled with iodobenzene, giving the
desired monomers 1(m) in high yields (85–97 %) after purifi-
cation by column chromatography. It is noteworthy that 3(m)
could be prepared also by lithiation of carbazole followed by
subsequent reaction with n-chloro-1-alkynes.[6c,8] The isolated
yields (,70 %), however, were much lower than those achieved
by the present method, regardless of its more complicated pro-
cedure. While 1(3) and 1(4) were pale yellow solids, 1(9) was a
yellow viscous liquid. All the monomers were characterised by
standard spectroscopic methods and elemental analyses, and all
gave satisfactory data corresponding to their structures (see data
given in the Experimental Section and spectra provided in the
Supplementary Material).
Polymerisation by Metathesis Catalysts
Since NbCl5– and TaCl5–Ph4Sn were effective catalysts for
the polymerisation of 1-pheny-1-alkynes[11] and 1-(p-9-
carbazolylphenyl)-2-phenylacetylene,[6d] we thus tried whether

1230
J. W. Y. Lam et al.
Table 2. Polymerisation of 6-(9-carbazolyl)-1-phenyl-1-hexyne [1(4)]A
Fig. 2 shows the 13C NMR spectra of 1(9) and P1(9) in
CDCl3. The spectrum of P1(9) displayed no acetylene carbon
resonances of 1(9) at d 90.4 and 80.6. It also exhibited no phenyl
and methylene acetylene carbon absorptions due to their trans-
formations to the styrene and allylic structures in the polymer.
The olefin backbone absorptions, however, were hard to distin-
guish, possibly due to overlap with the carbon resonances of the
carbazole pendant.
No.
Catalyst
Temp [8C]
Yield [%]
MwB
Mw/MBn
1
2
3
4
5
6
NbCl5–Ph4Sn
TaCl5–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
MoCl5–Ph4Sn
60
60
rt
14.2
Trace
Trace
81.1
41.6
0
11200
3.3
60
80
60
58100
16500
3.3
2.1
Thermal Stability and Electronic Absorption
ACarried out under nitrogen in toluene for 24 h; [M]0 ¼ 0.2 M, [cat.] ¼
[cocat.] ¼ 10 mM.
As stated in the introduction, unsubstituted polyacetylene has
found little technological applications owing to its low thermal
stability. Its derivatives with appropriate substituents, however,
are thermally much more stable. For example, the 5 % weight
loss for poly(1-phenyl-1-propyne) occurs at 3308C.[12] As
shown in Fig. 3, our polymers showed greater thermal stability
in the thermogravimetric analysis, with higher degradation
temperatures ($4008C). Clearly, this is due to the presence of
the carbazole pendant, which may wrap the polyacetylene
backbone and thus protect it from thermal degradation.[13]
Polymers with longer spacer lengths degraded readily at lower
temperatures. This is understandable because of the plasticising
effect of the alkyl spacer, which allows the polymers to melt at
relatively low temperatures.
BDetermined by GPC in THF on the basis of a polystyrene calibration.
Table 3. Polymerisation of 11-(9-carbazolyl)-1-phenyl-1-undecyne
[1(9)]A
No.
Catalyst
Temp [8C]
Yield [%]
MwB
Mw/MBn
1
2
3
4
5
6
NbCl5–Ph4Sn
TaCl5–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
WCl6–Ph4Sn
MoCl5–Ph4Sn
60
60
rt
Trace
0
61.5
99.1
82.5
Trace
107200
181800
105000
2.8
5.0
2.8
60
80
60
The absorption spectrum of P1(3) in THF is shown in Fig. 4.
Whereas 1(3) absorbed no photons with wavelengths longer
than 340 nm, the spectrum of P1(3) was well extended to the
visible spectral region. Certainly, the absorptions at the longer
wavelengths are obviously from the double-bond backbone of
the polymer. The spacer length had little effect on the ground-
state electronic transitions: the UV spectra of P1(4) and P1(9)
were almost identical to that of P1(3).
ACarried out under nitrogen in toluene for 24 h; [M]0 ¼ 0.2 M, [cat.] ¼
[cocat.] ¼ 10 mM.
BDetermined by GPC in THF on the basis of a polystyrene calibration.
same catalyst, however, was completely soluble and possessed a
high molecular weight, allowing us to investigate its properties
by ‘wet’ spectroscopic methods. Attempts to polymerize 1(4) by
MoCl5–Ph4Sn also ended up in disappointment.
Photoluminescence
Unlike 1(3) and 1(4), 1(9) underwent sluggish polymerisa-
tion in the presence of NbCl5–Ph4Sn catalyst (Table 3, no. 1).
TaCl5–Ph4Sn also failed to polymerise the monomer because
1(9) shared a common structural feature with 1(3) and 1(4): it
possessed a polar functional pendant group. Whereas reactions
of 1(3) and 1(4) catalysed by WCl6–Ph4Sn at room temperature
gave only a trace amount of polymeric product, stirring a toluene
solution of 1(9) under the same conditions, surprisingly, pro-
duced a high molecular weight polymer in a high yield. The
polymerisation proceeded much better at elevated temperatures
and the highest molecular weight and yield obtained were
1.8 ꢂ 105 g molꢁ1 and 99 %, respectively. MoCl5–Ph4Sn, in
contrast, failed to produce any polymeric product.
Previous studies show that the PL properties of polyacetylenes
were sensitive to their molecular structures.[14,15] For example,
poly(phenylacetylene)s were incapable of emitting light but
their disubstituted cousins such as poly(1-phenyl-1-alkyne)s
(PPAs) and poly(diphenylacetylene)s were strong emitters.
Being derivatives of PPAs, P1(m) were also anticipated to emit
intensely upon photoexcitation. Fig. 5a shows the PL spectra
of P1(m) in THF. When the THF solution of P1(3) was UV-
irradiated, it emitted a strong blue light of 448 nm, whose
intensity was more than three-fold higher than that of poly(1-
phenyl-1-octyne) (PPO) under the same measurable conditions.
The fluorescence quantum efficiency (FF ¼ 80 %) calculated
using 9,10-diphenylanthracene (FF ¼ 90 % in cyclohexane) as
standard was also much higher than that of PPO (FF ¼ 43 %),
revealing that the optical properties of polyacetylenes can be
readily manipulated by molecular engineering, and the incor-
poration of chromophoric units into the PAA structure has
resulted in polymers with stronger and more efficient emissions.
The bulky carbazole pendant may have better alleviated the
interaction between the polymer chains. The excitons are thus
likely to be confined in the isolated polymer chain and their
chances to recombine radiatively are increased. Moreover, as
the PL spectrum of carbazole overlaps with the absorption
spectrum of the polyacetylene backbone, the light emitted by the
former at ,370 nm is absorbed by the latter, which pumps it to
its excited state. When the excitons decay back to their ground
state, a strong, blue light is emitted from the polymer chain.
Polymers P1(4) and P1(9) emitted at similar wavelengths with
Structural Characterisation by Spectroscopic Methods
The molecular structures of the polymers were characterised by
spectroscopic methods with satisfactory results. An example of
the 1H NMR spectra of P1(9) and its monomer 1(9) is given in
Fig. 1. The phenyl acetylene protons of 1(9) absorbed at ,d 7.37
and 7.24, which shifted to d 6.80 after the polymerisation. The
peak was broad because the phenyl protons were attached to a
stiff polyacetylene structure, whose motion was limited by the
backbone. Similarly, the resonance of the methylene protons
next to the triple bond of 1(9) also became much broader in the
polymer. No other unexpected signals were found and all the
absorptions peaks could be readily assigned, suggesting that
the polymeric product was indeed P1(9) with a molecular
structure as shown in the inset of Fig. 1b.

Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s
1231
2
(a)
3
1
3
2
6
4
a
C
C
CH2CH2(CH2)5CH2CH2
4
N
g
b
c
d
e
f
5
5
8
6
a(3–5),
g(2, 7)
7
a(2, 6),
g(1, 3, 6, 8)
b
f
g(4–5)
d
c
e
4
(b)
3
a
2
5
6
2
3
1
C
C
]
[
n
4
CH2CH2(CH2)5CH2CH2
N
g
*
b
c
d
e
f
5
8
g(1–3, 6–8)
d
g(4, 5)
6
7
b
e, c
f
a(2–6)
6.5
8.5
4.5
2.5
0.5
Chemical shift [ppm]
Fig. 1. 1H NMR spectra of CDCl3 solutions of (a) 1(9) and (b) its polymer P1(9) (sample from Table 3, no. 4). The
solvent peak is marked with an asterisk.
higher FF values, in agreement with the previous observations
that longer spacer length favours stronger PL and EL in
PPAs.[16]
those of the PL spectra, confirming that the EL emissions were
truly from the polymer emitting layer and that the excimer
emissions were unlikely involved in the EL process.
The change in the current density with the applied voltage of
the EL devices is shown in Fig. 6a. The current flowing through
the EL device of P1(3) was low until its turn-on voltage (13 V)
was reached. Afterwards, it increased exponentially. Unlike in
P1(3), the current density in the EL devices of P1(4) and P1(9)
remained low even at high voltage, presumably due to the lower
mobility of the charge carriers in their longer, insulating alkyl
chains. The light emitted from P1(3) was also weak at low
voltage but became stronger when the voltage exceeded 19 V
(Fig. 6b). The luminance reached its maximum value of
438 cd mꢁ2 at 26 V, which was bright enough for a flat panel
Electroluminescence
Electroluminescence from PPO have been studied in the late 90s
but only light of low luminance (0.5 cd mꢁ2) and efficiency
(0.01 %) was observed.[16a,16c] Since P1(m) are stronger PL
emitters than PPO, they were expected to show better device
performance. Since there is better efficiency in multilayer
devices compared with single-layer devices, we studied the EL
of P1(m) by fabrication of multilayer devices with a configu-
ration of ITO/P1(m)/BCP/Alq3/LiF/Al. All the polymers emit-
ted blue EL of 488 nm (Fig. 5b). The spectral patterns resembled

1232
J. W. Y. Lam et al.
3
2
1
0
(a)
P1(3)
P1(4)
P1(9)
*
*
(b)
240
290
340
390
440
Wavelength [nm]
Fig. 4. UV spectra of THF solutions of P1(3) (sample from Table 1, no. 4),
P1(4) (Table 2, no. 4), and P1(9) (Table 3, no. 4).
(a)
Φ
F [%]
160
130
100
70
40
10
P1(3) 80
P1(4) 92
Chemical shift [ppm]
97
43
P1(9)
PPO
Fig. 2. 13C NMR spectra of CDCl3 solutions of (a) 1(9) and (b) its polymer
P1(9) (sample from Table 3, no. 4). The solvent peaks are marked with
asterisks.
0
P1(3)
P1(4)
P1(9)
Ϫ20
Ϫ40
(b)
P1(3)
P1(4)
P1(9)
Ϫ60
Ϫ80
Ϫ100
100
200
300
400
500
600
Temperature [ЊC]
Fig. 3. TGA thermograms of P1(3) (sample from Table 1, no. 4), P1(4)
(Table 2, no. 4), and P1(9) (Table 3, no. 4) recorded under nitrogen at a
380
440
500
560
620
heating rate of 208C minꢁ1
.
Wavelength [nm]
Fig. 5. (a) PL spectra of THF solutions of P1(3) (sample from Table 1,
no. 4), P1(4) (Table 2, no. 4), P1(9) (Table 3, no. 4), and poly(1-phenyl-1-
octyne) (PPO). Concentration: 0.05 mM, excitation wavelengths (nm): 370
[P1(3), P1(4), and P1(9)] and 355 (PPO). (b) EL spectra of multilayer
devices of P1(3) (sample from Table 1, no. 4), P1(4) (Table 2, no. 4), and
P1(9) (Table 3, no. 4). Device configuration: ITO/P1(m)/BCP (20 nm)/Alq3
(30 nm)/LiF (0.8 nm)/Al.
display. Since no light was emitted from PPO using the same
device configuration, the strong EL intensity observed in P1(3)
was probably due to its unique molecular structure, which well
matched the band gaps of the electrodes. The luminance,
however, decreased upon further increment of the applied
voltage because of the destruction of the EL device by the large

Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s
1233
1400
(a)
500
400
300
200
100
0
(b)
P1(3)
P1(4)
P1(9)
P1(3)
P1(4)
P1(9)
1050
700
350
0
12
18
24
30 12
18
24
30
Voltage [V]
Fig. 6. (a) Current density and (b) luminance versus voltage curves in multilayer EL devices of P1(m) with a device
configuration of ITO/P1(m)/BCP (20 nm)/Alq3 (30 nm)/LiF (0.8 nm)/Al.
0.3
0.2
0.1
0
polymer led to poorer device performance: the EL efficiencies
of P1(4) and P1(9) were 2.9 and 1.7-folds lower than that
of P1(3).
The device performances of P1(m) are clearly better than the
previous results but there is still much room for improvement. In
our recent study, we found that the EL efficiency of chromo-
phore-containing PPAs could be largely enhanced by doping
with poly(9-vinylcarbazole) (PVK).[17] Would similar EL
enhancement be observed in P1(m)? To address this question,
we constructed three new EL devices using blends of P1(m) and
PVK at weight ratio of 1 : 4 as the emitting layers.[17a]
Table 4 summarises the device performances of the polymer
blends. All the EL devices started to emit at lower voltages.
Clearly, the addition of PVK improved hole transportation,
which in turn enhanced the recombination of holes and elec-
trons. The EL efficiency of polymers P1(3) and P1(4) was
greatly enhanced, whereas P1(9) remained constant. The exter-
nal quantum efficiency of an EL device of doped P1(3) was
0.63 %, which was more than two-fold higher than the undoped
one. The extent of enhancement was even higher in P1(4), with
the external quantum efficiency of the polymer blend being four
times higher than the pure polymer. It is noteworthy that the
emissions from the PVK-doped polymers were all 20 nm blue-
shifted from those of the pure polymers (Fig. 8). The exact
reason remains unclear at present but as the EL spectrum of PVK
is peaked at 440 nm, the electronic perturbation of PVK on the
optical properties of P1(m) should be, in most cases, responsible
for such phenomenon.
P1(3)
P1(4)
P1(9)
12
18
24
30
Voltage [V]
Fig. 7. External quantum efficiency versus voltage curves in multilayer
EL devices of P1(m) with a device configuration of ITO/P1(m)/BCP
(20 nm)/Alq3 (30 nm)/LiF (0.8 nm)/Al.
Fluorescent Photopatterning
injection current. The low current density in the EL devices of
P1(4) and P1(9) also resulted in weak EL emissions: the
When PPAs are irradiated by UV light in air, their emissions are
quenched due to photooxidation of the polymer chains. Since
our polymers are also light-emissive, we thus explored their
potential use in PL imaging. The polymers can form uniform,
tough films by solution spin-coating. UV irradiation of a thin
film of P1(4) through a copper mask bleached the exposed
regions, while the unexposed parts remained emissive. A pho-
topattern was thus generated without performing the develop-
ment process (Fig. 9).
luminance from P1(4) and P1(9) was merely 7 and 13 cd mꢁ2
respectively.
,
Fig. 7 shows the external quantum efficiency versus voltage
curves in EL devices of the polymers. The external quantum
efficiency of the P1(3)-based device increased with increasing
applied voltage and reached its maximum value of 0.29 % at
19 V. When the voltage was further increased, the efficiency,
however, became lower. Lengthening the spacer length in the

1234
J. W. Y. Lam et al.
Table 4. Performances of EL devices of pure and PVK doped P1(m)A
]
PolymerB
lmax [nm]
Von [V]
Lmax [cd mꢁ2
]
CEmax [cd Aꢁ1
]
PWmax [lm Wꢁ1
]
QEmax [%]
P1(3)
492
488
492
460
468
468
13
15
14
9
438
7
0.65
0.21
0.37
0.76
0.49
0.20
0.12
0.04
0.06
0.23
0.14
0.06
0.29
0.10
0.17
0.63
0.40
0.18
P1(4)
P1(9)
13
P1(3):PVK
P1(4):PVK
P1(9):PVK
72
11
10
314
219
ADevice configuration: ITO/P1(m)(:PVK)/BCP (20 nm)/Alq3 (30 nm)/LiF (0.8 nm)/Al. Abbreviation: lmax ¼ emission maximum, Von ¼ turn-on voltage,
Lmax ¼ maximum luminance, CEmax ¼ maximum current efficiency, PWmax ¼ maximum power efficiency, QEmax ¼ maximum external quantum efficiency.
BPure P1(m) or their blends with PVK (1 : 4 by weight) were used as emitting layers.
P1(3):PVK
P1(4):PVK
P1(9):PVK
PVK
50 μm
Fig. 9. Two-dimensional photopattern generated by photooxidation of
P1(4) film in air at room temperature for 5 min. The photograph was taken
under UV illumination.
380
440
500
560
620
Wavelength [nm]
Poly(p-phenylene),[18] poly(alkylfluorene),[19] and poly(p-
phenylene vinylene) derivatives[20] are well known blue light-
emitting polymers. Although intense blue PL has been observed
in PPO, it, however, shows an inferior EL performance. Our
work presented here shows that by engineering of the molecular
structures of the polymers and optimization of the EL config-
urations, disubstituted polyacetylenes can emit strong EL in
high efficiency and are promising light-emitting materials.
Fig. 8. EL spectra of PVK and multilayer devices of PVK-doped P1(3)
(sample from Table 1, no. 4), P1(4) (Table 2, no. 4), and P1(9) (Table 3,
no. 4). Device configuration: ITO/P1(m):PVK/BCP (20 nm)/Alq3 (30 nm)/
LiF (0.8 nm)/Al.
Conclusions
In this work, carbazole-containing PPAs with different spacer
lengths were synthesised and the effect of the chromophoric unit
on the optical properties of the polymers was investigated. The
findings can be summarised as follows: (1) The monomers were
prepared in high yields by consecutive substitution and coupling
reactions of n-chloro-1-alkynes. Their polymerisation was
effected by NbCl5– and WCl6–Ph4Sn, giving high molecular
weight (Mw up to 1.8 ꢂ 105) polymers in high yields (isolation
yield up to 99 %). (2) All the polymers possessed high thermal
stability and degraded at high temperatures ($4008C), due to the
protective jacket effect contributed by the phenyl and carbazole
pendants. (3) The polymers emitted strong blue light of
,450 nm in THF solutions with high quantum efficiencies up to
92 %. (4) Multilayer EL devices with configurations of ITO/
P1(m)(:PVK)/BCP/Alq3/LiF/Al were constructed, which gave
blue light with maximum luminance and external quantum
efficiency of 438 cd mꢁ2 and 0.63 %. (5) The polymers were
photosensitive and UV irradiation of their thin films through
copper masks oxidized and quenched the light emission
of the exposed parts, generating two-dimensional luminescent
photopatterns.
Experimental
Materials
˚
Toluene (BDH) was pre-dried over 4 A molecular sieves and
distilled from sodium benzophenone ketyl immediately before
use. Dichlorobis(triphenylphosphine)palladium(II), copper(I)
iodide, carbazole, 5-chloro-1-pentyne 2 (m ¼ 3), 6-chloro-1-
hexyne
2
(m ¼ 4), iodobenzene, tungsten(VI) chloride,
tantalum(V) chloride, niobium(V) chloride, tetraphenyltin,
poly(9-vinylcarbazole) (PVK), tris(8-hydroxyquinolinolato)
aluminium (Alq3), and 2,9-dimethyl-4,7-diphenyl-1,10-
phenanthroline were purchased from Aldrich and used without
further purification. Molybdenum(V) chloride was purchased
from Acros. Acetylene 11-chloro-1-undecyne 2 (m ¼ 9) was
prepared by reaction of 11-undecyn-1-ol with thionyl chloride.
Instruments
The mass spectra were recorded on a Finnigan TSQ 7000 triple
quadrupole mass spectrometer operating in a chemical ioniza-
tion (CI) mode using methane as carrier gas. Elemental analysis

Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s
1235
was performed on a ThermoFinnigan Flash EA1112. The
molecular weights of the polymers were estimated by a Waters
Associates GPC system using a set of monodisperse polystyrene
standards for the molecular weight calibration. The 1H and
13C NMR spectra were measured on a Bruker ARX 300 NMR
spectrometer. The thermal stability of the polymers was
evaluated on a Perkin Elmer TGA 7 under dry nitrogen at a
heating rate of 208C minꢁ1. The UV spectra were measured on a
Milton Roy Spectronic 3000 Array spectrophotometer. The PL
spectra of the polymers in THF were recorded on a Perkin-
Elmer LC 5 luminescence spectrofluorometer. EL spectra
were obtained on a Kollmorgen Instrument PR650 photo-
spectrometer. The luminescence area was 12.6 mm2. Current-
voltage characteristics were obtained using a Hewlett-Packard
HP4145B Semiconductor Analyzer.
5-(9-Carbazolyl)-1-Phenyl-1-Pentyne [1(3)]
Compound 1(3) was prepared by Pd-catalysed coupling of
3(3) (1.7 g, 7.2 mmol) with iodobenzene (1.8 g, 8.9 mmol) in the
presence of Pd(PPh3)2Cl2 (0.1 g, 0.14 mmol), CuI (0.1 mg,
0.1 mmol) and PPh3 (0.2 mg, 0.1 mmol) in triethylamine
(50 mL) under nitrogen. The procedures were similar to those
of previously published paper.[13a] Monomer 1(4) and 1(9) were
prepared by similar procedures and their characterisation data
are given below.
Characterisation Data of 1(3)
Pale yellow solid; yield 96.9 %. (Found: C 88.90, H 6.22,
N 4.60. C23H19N requires C 89.28, H 6.19, N 4.53 %). 1H NMR
(300 MHz, CDCl3), d (ppm): 8.10 (d, J ¼ 7.2 Hz, 2H, Carbazole
(Car)–H at 4 and 5 positions), 7.48 (m, 6H, Car–H at 1, 3, 6, and
8 positions and Ar–H ortho to CꢀC), 7.32 (m, 3H, Ar–H para
and meta to CꢀC), 7.24 (m, 2H, Car–H at 2 and 7 positions),
4.50 (t, J ¼ 6.8 Hz, 2H, NCH2), 2.44 (t, J ¼ 6.8 Hz, 2H, ꢀCCH2),
2.19 (m, 2H, ꢀCCH2CH2). 13C NMR (75 MHz, CDCl3),
d (ppm): 140.4, 131.5 (aromatic carbons ortho to CꢀC), 128.3
(aromatic carbons meta to CꢀC), 127.8 (aromatic carbon para to
CꢀC), 125.6, 123.6 (aromatic carbon linked with CꢀC), 122.8,
120.3, 118.9, 108.6, 89.0 (ꢀCCH2), 81.6 (ArCꢀ), 41.5 (NCH2),
27.8 (ꢀCCH2CH2), 17.0 (ꢀCCH2). m/z (CI) 310.1 [MþH]þ
requires 310.1.
PL Quantum Yield
The PL quantum yields of the polymers in THF solutions
were estimated by the literature method[21] using 9,10-
diphenylanthracene as reference.
Fabrication of EL Devices
Multilayer EL devices were prepared by spin-coating toluene
solutions of P1(m) or their blends with PVK (1 : 4 by weight)
onto ITO glass.[17a] The thickness of thin films of P1(3), P1(4),
and P1(9) were 75, 65, and 66 nm, respectively while those of
the PVK–doped films were all 60 nm. BCP (hole-block layer;
20 nm), Alq3 (electron-transport layer; 30 nm), LiF (electron-
injection layer; 0.8 nm), and Al were in turn deposited under
vacuum (2 ꢂ 10ꢁ6 Torr).
Characterisation Data of 6-(9-Carbazolyl)-1-Phenyl-
1-Hexyne [1(4)]
Pale yellow solid; yield 86.9 %. (Found: C 88.74, H 6.64,
N 4.47. C24H21N requires C 89.12, H 6.54, N 4.33 %). 1H NMR
(300 MHz, CDCl3), d (ppm): 8.10 (d, J ¼ 7.6 Hz, 2H, Car–H at 4
and 5 positions), 7.44 (m, 4H, Car–H at 1, 3, 6 and 8 positions),
7.34 (m, 2H, Ar–H ortho to CꢀC), 7.24 (m, 5H, Ar–H para and
meta to CꢀC and Car–H at 2 and 7 positions), 4.30 (t, J ¼ 7.2 Hz,
2H, NCH2), 2.44 (t, J ¼ 7.2 Hz, 2H, ꢀCCH2), 2.07 (m, 2H,
NCH2CH2), 1.66 (m, 2H, ꢀCCH2CH2). 13C NMR (75 MHz,
CDCl3), d (ppm): 140.3, 131.5 (aromatic carbons ortho to CꢀC),
128.2 (aromatic carbons meta to CꢀC), 127.6 (aromatic carbon
para to CꢀC), 125.6, 123.7 (aromatic carbon linked with CꢀC),
122.8, 120.3, 118.7, 108.6, 89.3 (ꢀCCH2), 81.3 (ArCꢀ), 42.4
(NCH2), 27.9, 26.0, 19.0 (ꢀCCH2). m/z (CI) 324.1 [MþH]þ
requires 324.1.
Photopatterning
Photooxidation of the film of P1(4) was conducted in air at room
temperature using 365 nm light obtained from a Spectroline
ENF-280C/F UV lamp (diameter ¼ 5 cm) at a distance of 1 cm
as light source. The intensity of the incident light was
,18.5 mW cmꢁ2. The film was prepared by spin coating the
polymer solution (5 mg mLꢁ1 in 1,2-dichloroethane) at 1000rpm
for 1 min on a silicon wafer, and was dried under vacuum at 408C
for 1 h. The photopattern was then generated using procedures as
described in our previous paper.[17c]
Monomer Synthesis
The carbazole-containing 1-phenyl-1-alkynes 1(m) were pre-
pared by substitution and coupling reactions of n-chloro-1-
alkynes. Typical procedures for the synthesis of the monomers
are as follows:
Characterisation Data of 11-(9-Carbazolyl)-1-Phenyl-
1-Undecyne [1(9)]
Pale yellow liquid: 90.2 %. (Found: C 88.23, H 8.15, N 3.68.
C29H31N requires C 88.50, H 7.94, N 3.56 %). 1H NMR
(300 MHz, CDCl3), d (ppm): 8.11 (d, J ¼ 7.6 Hz, 2H, Car–H at
4 and 5 positions), 7.43 (m, 6H, Car–H at 1, 3, 6 and 8 positions
and Ar–H ortho to CꢀC), 7.24 (m, 5H, Ar–H para and meta to
CꢀC and Car–H at 2 and 7 positions), 4.28 (t, J ¼ 7.2 Hz, 2H,
NCH2), 2.38 (t, J ¼ 7.2 Hz, 2H, ꢀCCH2), 1.84 (m, 2H,
NCH2CH2), 1.57 (m, 2H, ꢀCCH2CH2), 1.43–1.29 [m, 10H,
(CH2)5]. 13C NMR (75 MHz, CDCl3), d (ppm): 140.4, 131.5
(aromatic carbons ortho to CꢀC), 128.1 (aromatic carbons meta
to CꢀC), 127.4 (aromatic carbon para to CꢀC), 125.5, 124.1
(aromatic carbon linked with CꢀC), 122.8, 120.3, 118.6, 108.6,
90.4 (ꢀCCH2), 80.6 (ArCꢀ), 42.9 (NCH2), 29.3, 29.0, 28.8,
28.9, 28.8, 28.6, 27.2, 19.3 (ꢀCCH2). m/z (CI) 394.1 [MþH]þ
requires 394.1.
5-(9-Carbazolyl)-1-Pentyne [3(3)]
To a mixture of carbazole (2.0 g, 12.0 mmol) and a catalytic
amount of tetrabutylammonium bromide in 30 mL of benzene
and 30 mL of 50 % aqueous KOH, was added 5-chloro-1-
pentyne (1.0 g, 9.8 mmol). The reaction mixture was refluxed
for 12 h. The crude product was extracted with chloroform and
purified by silica-gel column chromatography using hexane/
chloroform mixture (4 : 1 by volume) as eluent. A pale yellow
solid was isolated in 88.0 % yield (2.0 g). 6-(9-Carbazoyl)-1-
hexyne [3(4)] and 11-(9-carbazoyl)-1-undecyne [3(9)] were
prepared in a similar fashion and obtained as yellow solids in
84.7 and 93.7 % yields, respectively.

1236
J. W. Y. Lam et al.
Polymerisation
(c) A. J. Heeger, Angew. Chem. Int. Edit. 2001, 40, 2591.
doi:10.1002/1521-3773(20010716)40:14,2591::AID-ANIE2591.
3.0.CO;2-0
The polymerisation reactions and manipulations of 1(m) were
carried out under nitrogen using Schlenk techniques in a vacuum
line system or an inert-atmosphere glovebox (Vacuum Atmo-
spheres), except for the purification of the polymers, which was
done in an open atmosphere. Typical experimental procedures
for the polymerisation can be found in our previous
publications.[17]
[2] (a) J. C. W. Chien, Polyacetylenes 1984 (Academic Press: New
York, NY).
(b) Handbook of Conducting Polymers 1986 (Ed. T. A. Skotheim)
(Marcel Dekker: New York, NY).
(c) I. V. Krivoshei, V. M. Skorobogatov, Polyacetylenes and Polyar-
ylenes: Synthesis and Conducting Properties 1991 (Gordon and
Breach Science: New York, NY).
Characterisation Data of Poly[5-(9-Carbazolyl)-1-
Phenyl-1-Pentyne] [P1(3)]
[3] (a) S. K. Choi, Y. S. Gal, S. H. Jin, H. K. Kim, Chem. Rev. 2000, 100,
1645. doi:10.1021/CR960080I
(b) U. H. F. Bunz, Acc. Chem. Res. 2001, 34, 998. doi:10.1021/
AR010092C
(c) M. B. Nielsen, F. Diederich, Chem. Rev. 2005, 105, 1837.
doi:10.1021/CR9903353
(d) W. Zhang, J. S. Moore, Angew. Chem. Int. Edit. 2006, 45, 4416.
doi:10.1002/ANIE.200503988
(e) T. Masuda, J. Polym. Sci. A Polym. Chem. 2007, 45, 165.
doi:10.1002/POLA.21782
Yellow powdery solid; yield 79.3%. Mw 43000; Mw/Mn 2.2
(GPC; Table 1, no. 4). 1H NMR (300 MHz, CDCl3), d (ppm):8.08
(br, Car–H at 4 and 5 positions), 7.23 (br, Car–H at 1–3 and
6–8 positions), 3.60 (NCH2), 1.64 (¼CCH2 and ¼CCH2CH2).
13C NMR (75 MHz, CDCl3), d (ppm): 139.7, 125.5, 122.5,
120.2, 118.5, 108.6, 41.2, 27.0. UV (THF, 4.5 ꢂ 10ꢁ5 mol Lꢁ1),
l
max/emax: 296 nm/1.5ꢂ 104 molꢁ1 L cmꢁ1
.
(f) J. Wu, W. Pisula, K. Mullen, Chem. Rev. 2007, 107, 718.
doi:10.1021/CR068010R
Characterisation Data of Poly[6-(9-Carbazolyl)-1-
(g) J. G. Rudick, V. Percec, New J. Chem. 2007, 31, 1083. doi:10.1039/
B616449H
(h) K. Akagi, Polym. Int. 2007, 56, 1192. doi:10.1002/PI.2279
(i) S. W. Thomas, G. D. Joly, T. Swager, Chem. Rev. 2007, 107, 1339.
doi:10.1021/CR0501339
(j) W. Y. Wong, Macromol. Chem. Phys. 2008, 209, 14. doi:10.1002/
MACP.200700563
(k) Y. Morisaki, Y. Chujo, Prog. Polym. Sci. 2008, 33, 346.
doi:10.1016/J.PROGPOLYMSCI.2007.11.003
Phenyl-1-Hexyne] [P1(4)]
Yellow powdery solid; yield 81.1%. Mw 58100; Mw/Mn 3.3
(GPC; Table 2, no. 4). 1H NMR (300 MHz, CDCl3), d (ppm):8.05
(br, Car–H at 4 and 5 positions), 7.17 (br, Car–Hx at 1–3 and 6–8
positions), 3.65 (NCH2), 0.91 (¼CCH2, NCH2CH2
and ¼CCH2CH2). 13C NMR (75 MHz, CDCl3), d (ppm): 139.7,
125.3, 122.6, 120.2, 118.7, 108.4, 41.5, 29.6. UV (THF, 3.0 ꢂ
10ꢁ5 mol Lꢁ1), lmax/emax: 295 nm/1.3ꢂ 104 molꢁ1 L cmꢁ1
.
(l) E. Yashima, K. Maeda, Y. Furusho, Acc. Chem. Res. 2008, 41, 1166.
doi:10.1021/AR800091W
Characterisation Data of Poly[11-(9-Carbazolyl)-1-
Phenyl-1-Undecyne] [P1(9)]
[4] (a) J. Liu, J. W. Y. Lam, B. Z. Tang, Chem. Rev. 2009, 109, 5799.
doi:10.1021/CR900149D
Pale green powdery solid; yield 99.1 %. Mw 181800; Mw/Mn
5.0 (GPC; Table 3, no. 4). 1H NMR (300 MHz, CDCl3), d (ppm):
8.02 (br, Car–H at 4 and 5 positions), 7.30, 7.21 and 7.16 (br,
Car–H at 1–3 and 6–8 positions), 6.80 (br, Ar–H ortho, para
and meta to C¼C), 4.08 (NCH2), 1.66 (NCH2CH2 and
¼CCH2CH2), 1.13 [(CH2)5]. 13C NMR (75 MHz, CDCl3),
d (ppm): 140.2, 125.4, 122.7, 120.3, 118.6, 108.5, 42.9, 29.5,
29.0, 27.3. UV (THF, 1.9 ꢂ 10ꢁ5 mol Lꢁ1), lmax/emax: 295 nm/
(b) J. W. Y. Lam, B. Z. Tang, Acc. Chem. Res. 2005, 38, 745.
doi:10.1021/AR040012F
(c) J. W. Y. Lam, B. Z. Tang, J. Polym. Sci. A Polym. Chem. 2003, 41,
2607. doi:10.1002/POLA.10802
[5] (a) Y. D. Zhang, T. Wada, H. Sasabe, J. Mater. Chem. 1998, 8, 809.
doi:10.1039/A705129H
(b) C. Maertens, C. Detrembleur, P. Dubois, R. Je´roˆme, Chem. Mater.
1998, 10, 1010. doi:10.1021/CM970472L
(c) K. D. Belfield, C. Chinna, O. Najjar, Macromolecules 1998, 31,
2918. doi:10.1021/MA970910þ
1.7 ꢂ 104 molꢁ1 L cmꢁ1
.
(d) X. T. Tao, Y. D. Zhang, T. Wada, H. Sasabe, H. Suzuki,
T. Watauabe, S. Miyata, Adv. Mater. 1998, 10, 226. doi:10.1002/
(SICI)1521-4095(199802)10:3,226::AID-ADMA226.3.0.CO;2-E
[6] (a) S. Dumitrescu, V. Percec, C. I. Simionescu, J. Polym. Sci. Pol.
Chem. 1977, 15, 2893. doi:10.1002/POL.1977.170151206
(b) I. Km´ınek, V. Cimurova´, S. Nespurek, Macromol. Chem. Physic.
1989, 190, 1025. doi:10.1002/MACP.1989.021900511
(c) M. Nakano, T. Masuda, T. Higashimura, Polym. Bull. 1995, 34,
191. doi:10.1007/BF00316395
Supplementary Material
1H and 13C NMR spectra of the monomers 1(m) are available on
the Journal’s website.
Acknowledgements
The work reported in this paper was partially supported by the RPC and SRFI
Grants of HKUST (RPC10SC13, RPC11SC09, and SRFI11SC03PG), the
Research Grants Council of Hong Kong (604711, 603509, HKUST2/CRF/
10, and N_HKUST620/11), the Innovation and Technology Commission
(ITCPD/17–9),theUniversityGrantsCommitteeofHongKong(AoE/P-03/08
and T23–713/11–1) and the National Science Foundation of China
(20974028). B.Z.T. thanks the support from the Cao Guangbiao Foundation of
Zhejiang University.
(d) H. Tachimori, T. Masuda, J. Polym. Sci. A Polym. Chem. 1995, 33,
2079. doi:10.1002/POLA.1995.080331215
(e) T. Sata, R. Nomura, T. Wada, H. Sasabe, T. Masuda, J. Polym. Sci.
A Polym. Chem. 1998, 36, 2489. doi:10.1002/(SICI)1099-0518
(199810)36:14,2489::AID-POLA7.3.0.CO;2-O
(f) J.-W. Park, J.-H. Lee, H.-N. Cho, S.-K. Choi, Macromolecules
1993, 26, 1191. doi:10.1021/MA00057A048
References
[7] (a) G. Costa, Comprehensive Polymer Science 1989, Vol. 4, Chapter 9
[1] (a) H. Shirakawa, Angew. Chem. Int. Edit. 2001, 40, 2574.
doi:10.1002/1521-3773(20010716)40:14,2574::AID-ANIE2574.
3.0.CO;2-N
(Pergamon: Oxford).
(b) T. Masuda, T. Higashimura, Silicon-Based Polymer Science
1990, Chapter 35 (American Chemical Society: Washington,
D. C.).
(b) A. G. MacDiarmid, Angew. Chem. Int. Edit. 2001, 40, 2581.
doi:10.1002/1521-3773(20010716)40:14,2581::AID-ANIE2581.
3.0.CO;2-2
[8] P. P. S. Lee, Y. H. Geng, H. S. Kwok, B. Z. Tang, Thin Solid Films
2000, 363, 149. doi:10.1016/S0040-6090(99)01029-9

Carbazole-Functionalised Poly(1-phenyl-1-alkyne)s
1237
[9] (a) H. Z. Chen, R. S. Xu, Q. H. Sun, J. W. Y. Lam, M. Wang, B. Z.
Tang, Polym. Adv. Technol. 2000, 11, 442. doi:10.1002/1099-1581
(200008/12)11:8/12,442::AID-PAT990.3.0.CO;2-5
(b) B. Z. Tang, H. Z. Chen, R. S. Xu, J. W. Y. Lam, K. K. L. Cheuk,
H. N. C. Wong, M. Wang, Chem. Mater. 2000, 12, 213. doi:10.1021/
CM990552K
[10] J. W. Y. Lam, H. Peng, M. Ha¨ußler, R. Zheng, B. Z. Tang, Mol. Cryst.
Liq. Cryst. 2004, 415, 43. doi:10.1080/15421400490482024
[11] (a) M. Tabata, T. Sone, Y. Sadahiro, Macromol. Chem. Phys. 1999,
200, 265. doi:10.1002/(SICI)1521-3935(19990201)200:2,265::AID-
MACP265.3.0.CO;2-6
(f) Q. Zheng, R. Sun, X. Zhang, T. Masuda, T. Kobayashi, Jpn. J. Appl.
Phys. 1997, 36, L1508. doi:10.1143/JJAP.36.L1508
[16] (a) R. G. Sun, Q. B. Zheng, X. M. Zhang, T. Masuda, T. Kobayashi,
Jpn. J. Appl. Phys. 1999, 38, 2017. doi:10.1143/JJAP.38.2017
(b) M. Hirohata, K. Tada, R. Hidayat, T. Masuda, K. Yoshino, Jpn. J.
Appl. Phys. 1997, 36, L302. doi:10.1143/JJAP.36.L302
(c) R. G. Sun, T. Masuda, T. Kobayashi, Synth. Met. 1997, 91, 301.
doi:10.1016/S0379-6779(98)80046-5
(d) R. G. Sun, T. Masuda, T. Kobayashi, Jpn. J. Appl. Phys. 1996, 35,
L1673. doi:10.1143/JJAP.35.L1673
[17] (a) J. W. Y. Lam, A. Qin, Y. Q. Dong, Y. Hong, C. K. W. Jim, J. Liu,
Y. P. Dong, H. S. Kwok, B. Z. Tang, J. Phys. Chem. B 2008, 112,
11227. doi:10.1021/JP802009D
(b) J. L. Reddinger, J. R. Reynolds, Adv. Polym. Sci. 1999, 145, 57.
doi:10.1007/3-540-70733-6_2
(c) T. Masuda, T. Higashimura, Adv. Polym. Sci. 1987, 81, 121.
doi:10.1007/BFB0037614
(b) J. W. Y. Lam, Y. P. Dong, H. S. Kwok, B. Z. Tang, Macromolecules
2006, 39, 6997. doi:10.1021/MA0612576
(d) T. Masuda, T. Takahashi, T. Higashimura, Macromolecules 1985,
18, 311. doi:10.1021/MA00145A001
(e) E. J. Ginsburg, C. B. Gorman, R. H. Grubbs, Modern Acetylene
Chemistry 1995, Chapter 10, pp. 353–383 (Eds P. J. Stang,
F. Diederich) (VCH: New York, NY).
(c) J. W. Y. Lam,A. Qin, Y. Dong, L. M. Lai, M. Ha¨ussler, Y. Dong, B. Z.
Tang, J. Phys. Chem. B 2006, 110, 21613. doi:10.1021/JP064315Y
[18] (a) Y. Yang, Q. Pei, A. J. Heeger, J. Appl. Phys. 1996, 79, 934.
doi:10.1063/1.360875
(b) Y. Yang, Q. Pei, A. J. Heeger, Synth. Met. 1996, 78, 263.
doi:10.1016/0379-6779(96)80148-2
(c) G. Leising, S. Tasch, F. Meghdadi, L. Athouel, G. Froyer,
U. Scherf, Synth. Met. 1996, 81, 185. doi:10.1016/S0379-6779(96)
03751-4
[12] (a) T. Masuda, B. Z. Tang, T. Higashimura, H. Yamaoka, Macro-
molecules 1985, 18, 2369. doi:10.1021/MA00154A006
(b) T. Masuda, B. Z. Tang, T. Tanaka, T. Higashimura,
Macromolecules 1986, 19, 1459. doi:10.1021/MA00159A030
(c) H. Seki, H. B. Z. Tang, A Tanaka, T Masuda, Polymer (Guildf.)
1994, 35, 3456. doi:10.1016/0032-3861(94)90908-3
(d) S. M. Karim, R. Nomura, T. Masuda, J. Polym. Sci. A Polym. Chem.
2001, 39, 3130. doi:10.1002/POLA.1294
(d) S.-A. Chen, C.-I. Chao, Synth. Met. 1996, 79, 93. doi:10.1016/
0379-6779(96)80174-3
(e) M. Remmers, D. Neher, J. Gru¨ner, R. H. Friend, G. H. Gelinck,
J. M. Warman, C. Quattrocchi, D. A. dos Santos, J.-L. Gre´das,
Macromolecules 1996, 29, 7432. doi:10.1021/MA960599G
[19] (a) L. C. Palilis, D. G. Lidzey, M. Redeeker, D. D. C. Bradley,
M. Inbasekaran, E. P. Woo, W. W. Wu, Synth. Met. 2001, 121,
1729. doi:10.1016/S0379-6779(00)01492-2
[13] (a) Y. Dong, J. W. Y. Lam, H. Peng, K. K. L. Cheuk, H. S. Kwok,
B. Z. Tang, Macromolecules 2004, 37, 6408. doi:10.1021/
MA049094D
(b) J. W. Y. Lam, Y. P. Dong, K. K. L. Cheuk, J. D. Luo, Z. L. Xie,
H. S. Kwok, Z. S. Mo, B. Z. Tang, Macromolecules 2002, 35, 1229.
doi:10.1021/MA011406E
(b) X. Z. Jiang, S. Liu, H. Ma, A. K. Y. Jen, Appl. Phys. Lett. 2000, 76,
1813. doi:10.1063/1.126174
(c) J. W. Y. Lam, X. Kong, Y. P. Dong, K. K. L. Cheuk, K. Xu,
B. Z. Tang, Macromolecules 2000, 33, 5027. doi:10.1021/MA992097J
(d) X. Kong, B. Z. Tang, Chem. Mater. 1998, 10, 3352. doi:10.1021/
CM9803152
(e) B. Z. Tang, X. Kong, X. Wan, H. Peng, W. Y. Lam, X. Feng,
H. S. Kwok, Macromolecules 1998, 31, 2419. doi:10.1021/
MA971672L
(c) D. Sainova, T. Mitera, H. G. Nothofer, U. Scherf, I. Glowacki,
J. Ulanaski, H. Fujikawa, D. Neher, Appl. Phys. Lett. 2000, 76, 1810.
doi:10.1063/1.126173
(d) J. P. Chen, G. Klaerner, J.-I. Lee, D. Markiewicz, V. Y. Lee,
R. D. Miller, J. C. Scott, Synth. Met. 1999, 107, 129. doi:10.1016/
S0379-6779(99)00145-9
(e) A. W. Grice, D. D. C. Bradley, M. T. Bernius, M. Inbasekaran,
W. W. Wu, E. P. Woo, Appl. Phys. Lett. 1998, 73, 629. doi:10.1063/
1.121878
(f) M. Ranger, D. Rondeau, M. Leclerc, Macromolecules 1997, 30,
7686. doi:10.1021/MA970920A
[14] (a) Y. M. Huang, J. W. Y. Lam, K. K. L. Cheuk, W. Ge, B. Z. Tang,
Macromolecules 1999, 32, 5976. doi:10.1021/MA990725R
(b) Y. M. Huang, W. Ge, J. W. Y. Lam, B. Z. Tang, Appl. Phys. Lett.
1999, 75, 4094. doi:10.1063/1.125547
(c) Y. M. Huang, J. W. Y. Lam, K. K. L. Cheuk, W. Ge, B. Z. Tang,
ThinSolidFilms 2000, 363, 146. doi:10.1016/S0040-6090(99)01028-7
(d) Y. M. Huang, W. Ge, J. W. Y. Lam, K. K. L. Cheuk, B. Z. Tang,
Mater. Sci. Eng. B 2001, 85, 122. doi:10.1016/S0921-5107(01)
00543-8
(g) Y. Yang, Q. Pei, J. Appl. Phys. 1997, 81, 3294. doi:10.1063/
1.364313
(h) Q. Pei, Y. Yang, J. Am. Chem. Soc. 1996, 118, 7416. doi:10.1021/
JA9615233
[20] A. Hilberer, H.-J. Brouwer, B.-J. van der Scheer, J. Wildeman,
G. Hadziioannou, Macromolecules 1995, 28, 4525. doi:10.1021/
MA00117A022
[15] (a) C. H. Ting, C. S. Hsu, Jpn. J. Appl. Phys. 2001, 40, 5342.
doi:10.1143/JJAP.40.5342
(b) R. G. Sun, T. Masuda, T. Kobayashi, Jpn. J. Appl. Phys. 1996, 35,
L1434. doi:10.1143/JJAP.35.L1434
[21] (a) L. Liao, Y. Pang, Macromolecules 2001, 34, 7300. doi:10.1021/
MA0108923
(c) K. Tada, R. Hidayat, M. Teraguchi, T. Masuda, K. Yoshino, Jpn. J.
Appl. Phys. 1996, 35, L1138. doi:10.1143/JJAP.35.L1138
(d) R. G. Sun, Y. Z. Wang, D. K. Wang, Q. B. Zheng, A. J. Epstein,
Synth. Met. 2000, 111–112, 403. doi:10.1016/S0379-6779(99)00383-5
(e) R. Hidayat, M. Hirohata, K. Tada, M. Teraguchi, T. Masuda,
K. Yoshino, Jpn. J. Appl. Phys. 1997, 36, 3740. doi:10.1143/JJAP.
36.3740
(b) J. A. Osaheni, S. A. Jenekhe, J. Am. Chem. Soc. 1995, 117, 7389.
doi:10.1021/JA00133A012
(c) G. A. Crosby, J. N. Demas, J. Phys. Chem. 1971, 75, 991.
doi:10.1021/J100678A001
(d) J. D. Ingle, S. R. Crouch, Spectrochemical Analysis 1998,
pp. 52–55 (Prentice Hall: London).