Triphenylethylene carbazole derivatives as a new class of AIE materials with strong blue light emission and high glass transition temperature

Article abstract of DOI:10.1039/b902802a

A new class of aggregation-induced emission (AIE) compounds with strong blue-light-emitting properties and a high thermal stability, derived from triphenylethylene carbazole, has been synthesized. Their glass transition temperatures range from 126-151 °C

Full text of DOI:10.1039/b902802a

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PAPER
www.rsc.org/materials | Journal of Materials Chemistry
Triphenylethylene carbazole derivatives as a new class of AIE materials with
strong blue light emission and high glass transition temperature
a
Zhiyong Yang, Zhenguo Chi,
ab
Tao Yu,a Xiqi Zhang,a Meina Chen,a Bingjia Xu,a Siwei Liu,a Yi Zhanga
*
a
*
and Jiarui Xu
Received 10th February 2009, Accepted 12th May 2009
First published as an Advance Article on the web 19th June 2009
DOI: 10.1039/b902802a
A new class of aggregation-induced emission (AIE) compounds with strong blue-light-emitting
properties and a high thermal stability, derived from triphenylethylene carbazole, has been synthesized.
ꢀ
Their glass transition temperatures range from 126–151 C and the maximum fluorescence emission
wavelengths are 451–466 nm.
compound, but has a low Tg of 64 ꢀC, undergoes recrystallization
Introduction
after long periods of operation, and has a short device lifetime
compared to those of green and red materials.6
A large number of blue-light-emitting materials have been
investigated for applications in luminescent devices, such as
OLEDs,1 because emission at blue wavelengths is considered to
be the most important. However, the production of blue-light-
emitting materials with appropriate levels of brightness and
stability is not easy. This difficulty has mainly been attributed to
aggregation quenching, or low glass transition temperatures (Tg).
Most luminescent materials have very high luminescence effi-
ciency in dilute solutions, but exhibit relatively weak emission
when formed into thin films, owing to the aggregation of mole-
cules in the solid state to form species, such as excimers, which
emit far less light.2 Aggregation quenching seems to be an
intractable problem in the development of devices because
organic materials are normally used as thin solid films, in which
aggregation inherently accompanies film formation.3 It is thus
highly desirable to develop electroluminescent materials that can
emit intense light in the solid state and, thereby, overcome the
aggregation quenching problem. Indeed, a few rare compounds
have been found recently that show significant enhancement of
their light-emission upon aggregation or in the solid state. This
intriguing phenomenon is named aggregation-induced emission
(AIE) and thus these compounds have been named AIE mate-
rials.4 Since then, AIE materials have been found to be promising
emitters for the fabrication of highly efficient electroluminescent
devices and stimuli-responsive materials for use in multifunc-
tional switches.5 However, discoveries of AIE materials are quite
limited and most of them are silole-based compounds.4a–f
Recently, a number of carbazole derivatives7 have been used as
organic materials, due to their well known charge-transport
properties, luminescence, and high thermal stability. These
advantageous properties provoked our interest in introducing
the carbazole moiety into AIE materials.
Here, we report a new class of triphenylethylene carbazole
derivatives with strong blue light emission, high Tg and AIE effect.
It is expected that these molecules, with high thermal stability and
the triple functions of blue-light-emitting, AIE-active and charge-
transporting properties, are potential materials for blue-light
emitters in luminescent devices and fluorescence sensors.
Results and discussion
Synthesis
Our strategy for the synthesis of this new series of carbazole
derivatives is outlined in Scheme 1. It is well known that
The Tg of blue-light-emitting materials is another important
factor governing the stability and lifetime of devices. If a device is
heated above the Tg of the organic material components, irre-
versible failure can occur. For example, 4,40-bis(2,2-diphe-
nylvinyl)-1,10-biphenyl (DPVBi) is a commercially available
aKey Laboratory for Polymeric Composite and Functional Materials of
Ministry of Education, Materials Science Institute, School of Chemistry
and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275,
China. E-mail: chizhg@mail.sysu.edu.cn; xjr@mail.sysu.edu.cn; Fax:
+ 86 20 84112222; Tel: + 86 20 84111081
bKey Laboratory of Designed Synthesis and Application of Polymer
Material, School of Chemistry and Chemical Engineering, Sun Yat-sen
University, Guangzhou 510275, China
Scheme 1 Synthetic routes to the desired compounds.
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Table 1 Thermal and photophysical properties of target compounds
carbazole is a ‘generalist’ and many groups including halide,
alkyl, and aryl halide groups can be attached easily and selec-
tively to positions 3 and/or 6, and when the latter is used, the aryl
halide, can be converted readily into other functional groups.
Thus, many derivates of compound 1 can be constructed on the
basis of requirements such as high Tg, good solubility, high level
of efficiency, etc. In addition, intermediate 2 is also a ‘generalist’;
it can be formed directly by many kinds of cross-coupling reac-
tions and it is not difficult to convert aryl bromide into other
functionalized groups, such as aryl boric acid, aryl tin
compounds, aryl aldehydes, etc., which are important interme-
diates in the construction of conjugate organic molecules as
electroluminescent materials through the Suzuki, Heck, and
Wittig cross-coupling reactions. In other words, triphenyl-
ethylene carbazole can be used to obtain a variety of derivatives
according to our needs.
Tg/ꢀC
Tm/ꢀC
Td/ꢀC
l
/nm
l
/nm
max
abs
max
em
4
5
6
7
8
143.8
151.1
140.2
126.6
135.1
305.7
255.2
245.7
239.3
290.6
488.2
453.3
486.1
473.4
478.5
343a
360
343
342
343
463b 452c
464 466
464 462
458 450
453 451
a
b
In dichloromethane. In dichloromethane. c Solid powder.
The key precursor, compound 1, bis(4-(9H-carbazol-9-
yl)phenyl)methanone, was obtained in a single high-yield step
from carbazole and bis(4-fluorophenyl)methanone (94% yield);
therefore, the synthetic method is much simpler than the two-
step procedure starting from bis(4-aminophenyl)methanone that
is described in the literature.8 The key intermediate compounds
2, 9,90-(4,40-(2-(4-bromophenyl)ethene-1,1-diyl) bis(4,1-phenyl-
ene))bis(9H-carbazole) and
3
9,90-(4,40-(2-(4-fluoro-phenyl)-
ethene-1,1-diyl)bis(4,1-phenylene))bis(9H-carbazole), were
synthesized from compound 1 and the corresponding diethyl 4-
halogenobenzylphosphonates through the Wittig–Horner reac-
tion with more than 90% yields. Using a method similar to that
described for the synthesis of compound 1, reaction of compound
3 with carbazole gave the desired product 4, 9,90,900-(4,40,400-
(ethene-1,1,2-triyl)tris(4,1-phenylene))tris(9H-carbazole). Cross-
coupling of the intermediate compound 2 with corresponding
aromatic boric acids under Pd-catalyzed Suzuki conditions
afforded products 5, 9,90-(4,40-(2-(4-(pyren-1-yl)phenyl)ethene-1,1-
Fig. 1 DSC curves for compound 4 at scan rates of 10 ꢀC minꢁ1 (the
inset is a magnification of the figure near Tg).
As can be seen, relatively high Tg values are observed. The Tg
values of all compounds are above 126 ꢀC, while that of
compound 5 is the highest (151 ꢀC), due to the bulky pyrenyl
group. This Tg value is 2.3-fold higher than that of DPVBi
(64 ꢀC) and much higher than that (120 ꢀC) of 2-methyl-9,10-di-
(20-naphthyl)anthracene (MADN), two typical blue-light
emitters.9 It is also much higher than that of 1-methyl-
1,2,3,4,5-pentaphenylsilole (MPPS, 54 ꢀC) and 1,1,2,3,4,5-hex-
aphenylsilole (HPS, 65 ꢀC), two typical AIE-active compounds.10
The decomposition temperature (Td) is defined as the
temperature at which 5% weight loss occurs during heating. As
shown by the TGA curves presented in Fig. 2, the compounds
were highly stable, as they started to decompose at 453–488 ꢀC.
diyl)bis(4,1-phenylene))bis(9H-carbazole);
6,
9,90-(4,40-(2-(4-
(dibenzothiophene-4-yl)phenyl)ethene-1,1-diyl)bis(4,1-phenylene))
bis(9H-carbazole); 7, 9,90-(4,40-(2-(4-(naphthalen-1-yl)phenyl)-
ethene-1,1-diyl)bis(4,1-phenylene))bis(9H-carbazole);
and
8,
9,90-(4,40-(2-(terphenyl-4-yl)ethene-1,1-diyl)bis(4,1-phenyl-ene))bis-
(9H-carbazole), in acceptable yields from 49–65%. All
compounds (1–8) were strictly characterized with proton nuclear
magnetic resonance (1H-NMR), high-resolution mass spectros-
copy (HRMS), and elementary analysis (EA).
Thermal properties
The thermal and photophysical properties of these target
compounds are summarized in Table 1.
The thermal properties of these compounds were investigated
by differential scanning calorimetry (DSC) and thermogravi-
metric analysis (TGA). Similar to the DSC curves of compound 4
(see Fig. 1), all the compounds exhibited a melting peak in the
first heating runs. However, no melting peaks or crystallization
peaks, except a glass-transition peak, were noticed in the second
heating or cooling runs. This indicates very little crystal forma-
tion when cooling (even at a cooling rate of only 1 ꢀC minꢁ1
)
from the melting state, which is expected to yield better electro-
luminescent materials.
Fig. 2 TGA curves of compounds 4–8.
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The Td values of the compounds were also much higher than that
ꢀ
water–THF mixture. While the PL intensity in THF is only 15, it
is boosted to 180 in 90 : 10 (v/v) water–THF. Similar effects were
observed for the other compounds.
of the above AIE-active compounds, MPPS (309 C) and HPS
(351 ꢀC).10
Thermal behavior of organic compounds has a critical influence
on both the stability and the lifetime of luminescent devices. The
results presented here show the potential of these new materials as
blue-light-emitting materials in organic luminescent devices.
The quantitative enhancement of emission was estimated by
the PL quantum yields (FFL) of compound 4 in mixtures of water
and THF in various proportions, using 9,10-diphenylanthracene
(DPA) as the standard. As seen from Fig. 4, the FFL of the THF
solution was very low (FFL ¼ 0.016), and was almost unchanged
when water was added up to 60% (v/v), but started to increase
swiftly upon addition of water to 80% (v/v).
AIE properties
When the volume fraction of water in the water–THF mixture
was increased to 90%, FFL rose to 0.38, which is about 24-fold
higher than that of THF. The above results indicate that the
compound molecules started to aggregate markedly when the
volume fraction of water reached 80%. Since water is a non-
solvent of these compounds, the molecules must have aggregated
in the water–THF mixtures with higher water content. Appar-
ently, the emissions are induced by aggregation of the
compounds; in other words, they are AIE-active.
All of the compounds, except compound 5, exhibit a blue shift in
their emission in the solid state, compared to in dichloromethane
solution. However, solidification of many blue luminescence
materials produces a red-shift their emission spectra, which is
clearly undesirable.
Almost no photoluminescence (PL) signal could be detected
from a dilute solution of the compounds in tetrahydrofuran
(THF). Fig. 3 shows the corresponding emission spectra of
compound 4 in aqueous THF with different water/THF ratios.
The emission from the THF solution of 4 was so weak that
almost no PL signal was recorded. However, a dramatic
enhancement of luminescence was observed for the 60 : 40 (v/v)
Fig. 5 shows the effect of temperature on the PL relative peak
intensity of the compounds in dilute solutions. It can be seen that
the relative peak intensity of the DPA is almost unchanged
during the temperature increase from 75K. In contrast, all of the
new compounds have dramatic decreases near the melting point
of THF. But, the extent of the decrease is not the same for each
compound. The peak intensity of 6, which contains a benzo-
thiophene group, at 75K is about 120-fold higher than that at
room temperature; the value is about 40-fold for compounds 4
and 7, and less than 10-fold for compounds 5 and 8. The results
indicate that the AIE effect of frozen compound molecules in the
solid are similar to those due to aggregation in the liquid, due to
the restriction of rotation of groups.
The effect of temperature on the peak wavelength is different
between AIE compounds such as compound 4 and non-AIE
compounds such as DPA. As seen from Fig. 6, the two peak
wavelengths of compound 4 are red-shifted with increasing
temperature, but they are blue-shifted for DPA.
Fig.7 shows online pictures of the solvent evaporation proce-
dure of a drop of 4 solution in dichloromethane placed on
a weighing paper. Early in its development, the spot was wet and
could scarcely be visualized under irradiation at 365 nm (Fig. 7a).
But as the solvent evaporated, the image became brighter and
Fig. 3 PL spectra of 4 in water–THF mixtures. The inset depicts the
changes of PL peak intensity.
Fig. 4 Variation of PL quantum yield of 4 depending on water
fractions in the THF–water mixture. Inset is the emission images of 4 in
pure THF (left, 10ꢁ5 mol Lꢁ1) and in the THF–water mixture (right, 90%
water). The images were taken at room temperature under UV light
(lex ¼ 365 nm).
Fig. 5 Effect of temperature on the PL relative peak intensity of the
compounds, and DPA, in THF.
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Fig. 8 On/off fluorescence switching of compound 4 on TLC plates
without vapor (a) and in CH2Cl2 vapor (b) under UV light (365 nm)
illumination at room temperature.
chromatography (TLC) plate (Fig. 8). Under UV light illumi-
nation (wavelength 365 nm) at room temperature, the spot
showed bright blue fluorescence, which was switched off
reversibly in an atmosphere of dichloromethane vapor. A
probable explanation is that solvation of the vapor of a good
solvent releases the interaction of solid molecules to a greater
extent and causes free rotation of single bonds of the AIE
molecules, leading to non-emission. Because AIE materials
possess the on/off fluorescence switching property in some
organic vapors, it is suggested that this could be one of their most
important potential applications, in the photoswitch field as
a chemical vapor sensor.
Fig. 6 Effect of temperature on the peak wavelength and intensity of
compound 4 (top) and DPA (bottom) (insets: right upper is the peak
wavelength vs. temperature and right lower is the relative PL intensity vs.
temperature).
Simulated conformation
The structure and optimized geometry of compound 4 are shown
in Fig. 9. It can been seen that the three phenyl rings rotate to
some degree relative to each other (dihedral angle q: C(17)–
C(20)–C(21)–C(27)
¼
ꢁ54.2ꢀ, C(22)–C(21)–C(20)–C(23)
¼
ꢁ52.7ꢀ, C(20)–C(22)–C(41)–C(46) ¼ ꢁ39.0ꢀ), which demon-
strates a twisted configuration of the compound in the isolated
state (single molecule) due to the bulky carbazole group
substituents on the benzene rings of triphenylethylene. Although
the mechanism underlying the AIE phenomenon is still unclear,
the twisted configuration is a common structural characteristic of
Fig. 7 Photographs taken online of a drop of 4 solution in CH2Cl2 on
a weighing paper under irradiation at 365 nm (time: a ¼ 1 s; b ¼ 3 s; c ¼ 5
s and d ¼ 7 s).
brighter (Fig. 7b,c), finally reaching full-size brightness after the
solvent had evaporated to dryness (Fig. 7d). This indicates that
these novel molecules are AIE-active.
Off/on switching properties
Application of the synthesized compounds to on/off fluorescence
Fig. 9 The lowest-energy conformer optimized using the MM2 force
field for compound 4. Hydrogen atoms are omitted for clarity.
switches was investigated with a spot of 4 on a thin-layer
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reported AIE molecules of either siloles,4a or 1-cyano-trans-1,2-
bis-(40-methylbiphenyl)ethylene (CN-MBE).4h
the mixture was stirred continuously for 2 h at room tempera-
ture. The reaction mixture was precipitated into ethanol, the
crude product was collected, and washed with ethanol three
times. The crude product was recrystallized from dichloro-
methane–n-hexane (1 : 20, v/v) to obtain 11.6 g white powder in
Conclusions
1
In this work, we have developed a new class of AIE-active
compounds, triphenylethylene carbazole derivatives. They
exhibit a strongly enhanced emission in the aggregated state, and
87% yield. H NMR (300 MHz, CDCl3) d (ppm): 7.05 (d, 2H),
7.11 (s, 1H), 7.27–7.57 (m, 16H), 7.58–7.71 (m, 6H), 8.10–8.24
(m, 4H); MS (FAB) m/z: 666 ([M]+, calcd for C44H29N2Br,
665.62); Anal. calcd for C44H29N2Br: C 79.40, H 4.39, Br 12.00,
N 4.21; found: C 79.42, H 4.42, N 4.16.
on/off fluorescent switching which is sensitive to organic vapor.
em
The derivatives are all blue-light emitters and their l
are in the
max
range 450–466 nm. These new derivatives have rather high levels
ꢀ
of thermal stability: their Tgs are in the range 126–151 C, and
Synthesis of 9,90-(4,40-(2-(4-fluorophenyl)ethene-1,1-diyl)bis-
their Td values are all above 450 ꢀC. It is suggested that they are
potential materials for blue light emitters in OLEDs and fluo-
rescence sensors.
(4,1-phenylene))bis(9H-carbazole) 3
The compound was prepared using the procedure described for 2
but using diethyl-4-fluorobenzylphosphonate instead of diethyl-
4-bromobenzylphosphonate in 85% yield.
Experimental
1H NMR (300 MHz, CDCl3) d (ppm): 6.97 (t, 2 H), 7.15–7.19
(m, 2 H), 7.31–7.37 (m, 4 H), 7.43–7.56 (m, 10 H), 7.56–7.70 (m, 7
H), 8.19 (dd, 4 H); MS (EI), m/z: 604 ([M]+, calcd for C44H29FN2,
604.71); Anal. calcd for C44H29FN2: C 87.39, H 4.83, F 3.14, N
4.63; found: C 87.41, H 4.85, N 4.60.
All reagents and chemicals purchased from Alfa Aesar were used
as received. Analytical grade DMF was purified by distillation
under an inert nitrogen atmosphere. Tetrahydrofuran (THF) was
distilled from sodium–benzophenone. Ultra-pure water was used
in the experiments. All other solvents were purchased as
analytical grade from Guangzhou Dongzheng Company, and
used without further purification. 1H-NMR spectra were
measured on a Mercury-Plus 300 spectrometer with chemical
shifts reported as ppm (in CDCl3, TMS as internal standard).
Mass spectra were measured with Thermo spectrometers
(MAT95XP-HRMS and DSQ-MS). Elemental analysis was
done with an Elementar Vario EL Elemental Analyzer. Fluo-
rescence spectra were determined with a Shimadzu RF-5301PC
spectrometer and the slit width was 3 nm for both excitation and
emission. Differential scanning calorimetry (DSC) curves were
obtꢀained with a TA thermal analyzer (Q10) at a heating rate of
10 C minꢁ1 under a N2 atmosphere. Thermogravimetric anal-
yses (TGA) were performed with a TA thermal analyzer (A50)
Synthesis of 9,90,900-(4,40,400-(ethene-1,1,2-triyl)tris(4,1-pheny-
lene))tris(9H-carbazole)
4
Carbazole (0.85 g, 5 mmol) was dissolved in anhydrous DMF
(20 mL) in a flask fitted with a magnetic stirrer and condenser.
Potassium tert-butoxide (0.61 g, 5.3 mmol) was added to the
above solution, heated at 70 ꢀC for 10 min and 3 (3.35 g, 5 mmol)
was added with stirring for 12 h. The mixture was cooled to room
temperature, and poured into ice–water. The mixture was filtered
and the crude product was purified by column chromatography
on silica, eluting with dichloromethane–n-hexane (1 : 1, v/v) to
1
yield 4 as an off-white powder (2.85 g, 76% yield). H NMR
under a N2 atmosphere with a heating rate of 20 C minꢁ1
.
ꢀ
(300 MHz, CDCl3) d (ppm): 7.29 (s, 1 H), 7.34 (t, 6 H), 7.41–7.57
(m, 16 H), 7.64–7.77 (m, 8 H), 8.18 (m, 6 H); 13C NMR (125
MHz, CDCl3) d (ppm): 141.76, 141.65, 140.75, 140.69, 140.61,
138.95, 137.45, 137.37, 136.50, 136.13, 132.02, 131.03, 129.02,
128.50, 127.49, 126.89, 126.48, 126.07, 126.00, 123.52, 123.49,
120.48, 120.34, 120.13, 120.10, 109.85, 109.78, 109.67; FT-IR
(KBr) n (cmꢁ1): 3049 (Ar and ¼C–H stretching), 1598, 1514,
1452, 1334, 1228, 835, 750, 723; MS (FAB), m/z: 752 ([M + H]+,
calcd for C56H37N3, 751); Anal. calcd for C56H37N3: C 89.45, H
4.96, N 5.59; Found: C 89.23, H 4.75, N 5.83%.
Synthesis of bis(4-(9H-carbazol-9-yl)phenyl)methanone 1
Carbazole (16.7 g, 100 mmol) was dissolved in anhydrous DMF
(150 mL) in a flask fitted with a magnetic stirrer and condenser.
Potassium tert-butoxide (11.8 g, 105 mmol) was added and the
mixture was heated at 70 ꢀC for 10 min and bis(4-fluo-
rophenyl)methanone (10.9 g, 50 mmol) was added with stirring
for 12 h. The mixture was cooled to room temperature, poured
into ice–water, filtered, and the crude residue was recrystallized
from acetone. A white powder was obtained (24.1 g, 94% yield).
1H NMR (300 MHz, CDCl3) d (ppm): 7.36 (t, 4 H), 7.48 (t, 4
H), 7.58 (d, 4 H), 7.82 (d, 4 H), 8.19 (d, 8 H); MS (FAB) m/z: 512
([M]+, calcd for C37H24N2O, 512.6); Anal. calcd for C37H24N2O:
C 86.69, H 4.72, N 5.46; O 3.12, found: C 86.72, H 4.68, N 5.44.
General procedure for synthesis of compounds 5–8
To a solution of 2 (1.33 g, 2 mmol) and the corresponding boric
acid (2 mmol) in toluene (20 mL), 2 M aqueous K2CO3 solution
(3 mL) was added and the mixture was stirred for 30 min under
an argon atmosphere. Then, the Pd(PPh3)4 catalyst (0.05 g) was
added all at once to the mixture. The reaction mixture was stirred
at 90 ꢀC for 24 h. After cooling, the product was extracted with
dichloromethane–water. The organic layers were collected and
dried under Na2SO4. The concentrated product was purified by
silica gel column chromatography (dichloromethane–n-hexane
from 1 : 5 to 1 : 1, v/v) to obtain pure products 5–8.
Synthesis of 9,90-(4,40-(2-(4-bromophenyl)ethene-1,1-diyl)bis(4,-
1-phenylene))bis(9H-carbazole) 2
A solution of compound 1 (10.3 g, 20 mmol) and diethyl-4-
bromobenzylphosphonate (6.2 g, 20 mmol) in anhydrous tetra-
hydrofuran (100 mL) was stirred under a N2 atmosphere at 0 ꢀC.
Postassium tert-butoxide (2.2 g, 20 mmol) was added quickly and
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Compound 5
Acknowledgements
1H NMR (300 MHz, CDCl3) d (ppm): 7.29–7.51 (m, 11 H),
7.57 (dd, 6 H), 7.65–7.78 (m, 8 H), 8.03 (t, 3 H), 8.12 (s, 2
H), 8.17–8.26 (m, 8 H); 13C NMR (125 MHz, CDCl3)
The authors gratefully acknowledge financial support from the
National Natural Science Foundation of China (Grant numbers:
50773096, 50473020), the Start-up Fund for Recruiting Profes-
sionals from ‘‘985 Project’’ of SYSU, the Science and Technology
Planning Project of Guangdong Province, China (Grant
numbers: 2007A010500001-2, 2008B090500196), and the
Construction Project for University–Industry cooperation plat-
form for Flat Panel Display from the Department of Information
Industry of Guangdong Province (Grant number: 20081203).
d
(ppm): 141.87, 141.25, 140.76, 140.14, 139.27, 137.28,
137.23, 137.11, 136.05, 132.06, 131.48, 130.95, 130.66, 130.45,
129.71, 129.14, 128.98, 128.41, 127.60, 127.48, 127.39, 126.85,
126.03, 126.00, 125.17, 125.08, 124.90, 124.86, 124.69 123.50,
120.37, 120.08, 109.87, 109.74; FT-IR (KBr) n (cmꢁ1): 3039
(Ar and ¼C–H stretching), 1597, 1513, 1450, 1315, 1226, 839,
746, 719; MS (FAB), m/z: 786 ([M]+, calcd for C60H38N2,
786); Anal. calcd for C60H38N2: C 91.57, H 4.87, N 3.56;
Found: C 91.42, H 5.01, N 3.48%.
References
1 (a) Y. H. Kim, D. C. Shin, S. H. Kim, C. H. Ko, H. S. Yu, Y. S. Chae
and S. K. Kwon, Adv. Mater., 2001, 13, 1690; (b) J. Shi and
C. W. Tang, Appl. Phys. Lett., 2002, 80, 3201; (c) S. W. Culligan,
A. C. A. Chen, J. U. Wallace, K. P. Klubek, C. W. Tang and
S. H. Chen, Adv. Funct. Mater., 2006, 16, 1481; (d) T. C. Chao,
Y. T. Lin, C. Y. Yang, T. S. Hung, H. C. Chou, C. C. Wu and
K. T. Wong, Adv. Mater., 2005, 17, 992; (e) Y. H. Kim,
H. C. Jeong, S. H. Kim, K. Yang and S. K. Kwon, Adv. Funct.
Mater., 2005, 15, 1799; (f) A. P. Kulkarni, A. P. Gifford,
C. J. Tonzola and S. A. Jenekhe, Appl. Phys. Lett., 2005, 86,
061106; (g) L. H. Chan, R. H. Lee, C. F. Hsieh, H. C. Yeh and
C. T. Chen, J. Am. Chem. Soc., 2002, 124, 6469; (h) D. Gebeyehu,
K. Walzer, G. He, M. Pfeiffer, K. Leo, J. Brandt, A. Gerhard,
Compound 6
1H NMR (300 MHz, CDCl3) d (ppm): 7.30–7.36 (m, 7 H),
7.45–7.52 (m, 6 H), 7.55–7.61 (m, 6 H), 7.63–7.76 (m, 10 H),
7.83 (t, 1 H), 8.16–8.23 (m, 6 H); 13C NMR (125 MHz,
CDCl3)
d (ppm): 141.77, 141.50, 140.76, 139.49, 139.37,
139.16, 138.40, 137.32, 137.24, 136.82, 136.43, 136.34, 135.75,
132.08, 130.10, 129.01, 128.02, 127.46, 126.86, 126.77, 126.05,
126.00, 125.14, 124.42, 123.50, 122.61, 121.73 120.56, 120.37,
120.08, 109.86, 109.81; FT-IR FT-IR (KBr) n (cmꢁ1): 3047
(Ar and ¼C–H stretching), 1599, 1512, 1446, 1336, 1226, 835,
746, 721; MS (FAB), m/z: 768 ([M]+, calcd for C56H36N2S,
768); Anal. calcd for C56H36N2S: C 87.47, H 4.72, N 3.64, S
4.17; Found: C 87.57, H 4.81, N 3.56, S 4.35%.
€
P. Stoßel and H. Vestweber, Synth. Met., 2005, 148, 205; (i)
C. C. Wu, Y. T. Lin, K. T. Wong, R. T. Chen and Y. Y. Chien,
Adv. Mater., 2004, 16, 61.
2 (a) R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes,
R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos,
J. L. Bredas, M. Logdlund and W. R. Salaneck, Nature, 1999, 397,
121; (b) S. A. Jenekhe and J. A. Osaheni, Science, 1994, 265, 765.
3 (a) C. T. Chen, Chem. Mater., 2004, 16, 4389; (b) T. W. Kwon,
M. M. Alam and S. A. Jenekhe, Chem. Mater., 2004, 16, 4657.
4 (a) J. D. Luo, Z. L. Xie, J. W. Y. Lam, L. Cheng, H. Y. Chen,
C. F. Qiu, H. S. Kwok, X. W. Zhan, Y. Q. Liu, D. B. Zhu and
B. Z. Tang, Chem. Commun., 2001, 1740; (b) J. W. Chen,
C. C. W. Law, J. W. Y. Lam, Y. P. Dong, S. M. F. Lo,
I. D. Williams, D. B. Zhu and B. Z. Tang, Chem. Mater., 2003, 15,
Compound 7
1H NMR (300 MHz, CDCl3) d (ppm): 7.30–7.37 (m, 7 H),
7.42–7.58 (m, 14 H), 7.64–7.77 (m, 8 H), 7.89 (d, 1 H), 7.93 (d, 1
H), 7.98 (d, 1 H), 8.17–8.21 (dd, 4 H); 13C NMR (125 MHz,
CDCl3) d (ppm): 141.86, 141.10, 140.74, 139.70, 139.67, 139.23,
137.24, 137.18, 136.03, 133.84, 132.01, 131.44, 129.92, 129.59,
129.14, 128.94, 128.34, 127.76, 127.44, 126.89, 126.82, 126.11,
126.02, 125.98, 125.80, 125.38, 123.48, 120.36, 120.06, 109.85,
109.71; FT-IR (KBr) n (cmꢁ1): 3043 (Ar and ¼C–H stretching),
1597, 1514, 1450, 1336, 1226, 835, 746, 721; MS (FAB), m/z: 712
([M]+, calcd for C54H36N2, 712); Anal. calcd for C54H36N2: C
90.98, H 5.09, N 3.93; Found: C 91.13, H 4.80, N 4.14%.
€
1535; (c) H. Tong, Y. Q. Dong, M. Haußler, J. W. Y. Lam,
H. H. Y. Sung, I. D. Williams, J. Z. Sun and B. Z. Tang, Chem.
Commun., 2006, 1133; (d) Y. Q. Dong, J. W. Y. Lam, A. J. Qin,
Z. Li, J. Z. Sun, H. H. Y. Sung, I. D. Williams and B. Z. Tang,
Chem. Commun., 2007, 40; (e) Y. Q. Dong, J. W. Y. Lam,
A. J. Qin, J. X. Sun, J. Z. Liu, Z. Li, J. Z. Sun, H. H. Y. Sung,
I. D. Williams, H. S. Kwok and B. Z. Tang, Chem. Commun., 2007,
€
3255; (f) H. Tong, Y. N. Hong, Y. Q. Dong, Y. Ren, M. Haussler,
J. W. Y. Lam, K. S. Wong and B. Z. Tang, J. Phys. Chem. B, 2007,
€
111, 2000; (g) H. Tong, Y. N. Hong, Y. Q. Dong, M. Haussler,
J. W. Y. Lam, Z. Li, Z. F. Guo, Z. H. Guo and B. Z. Tang, Chem.
Commun., 2006, 3705; (h) B. K. An, S. K. Kwon, S. D. Jung and
S. Y. Park, J. Am. Chem. Soc., 2002, 124, 14410; (i) S. Kim,
Q. Zheng, G. S. He, D. J. Bharali, H. E. Pudavar, A. Baev and
P. N. Prasad, Adv. Funct. Mater., 2006, 16, 2317.
Compound 8
1H NMR (300 MHz, CDCl3) d (ppm): 7.28 (s, 1 H), 7.31–7.41
(m, 6 H), 7.45–7.52 (m, 6 H), 7.54–7.61 (m, 7 H), 7.63–7.74 (m,
14 H), 8.20 (d, 4 H); 13C NMR (125 MHz, CDCl3) d (ppm):
141.91, 141.05, 140.76, 140.72, 140.60, 140.28, 139.34, 139.31,
139.22, 137.25, 137.20, 136.18, 132.02, 130.20, 129.06, 128.96,
128.82, 127.54, 127.39, 127.24, 127.01, 126.84, 126.68, 126.02,
125.99, 123.54, 123.49, 120.41, 120.35, 120.11, 120.06, 109.86,
109.79; FT-IR (KBr) n (cmꢁ1): 3030, 3449 (Ar and ¼C–H
stretching), 1595, 1512, 1450, 1336, 1228, 835, 744, 719; MS
(FAB), m/z: 738 ([M]+, calcd for C56H38N2, 738); Anal. calcd for
C56H38N2: C 91.03, H 5.18, N 3.79; Found: C 91.12, H 5.34, N
3.58%.
5 (a) L. P. Heng, Y. Q. Dong, J. Zhai, B. Z. Tang and L. Jiang,
Langmuir, 2008, 24, 2157; (b) H. Tong, Y. N. Hong, Y. Q. Dong,
M. Haussler, Z. Li, J. W. Y. Lam, Y. P. Dong, H. H. Y. Sung,
I. D. Williams and B. Z. Tang, J. Phys. Chem. B, 2007, 111, 11817.
6 S. Wang, W. J. Oldham Jr, R. A. Hudack Jr. and G. C. Bazan, J. Am.
Chem. Soc., 2000, 122, 5695.
7 (a) J. Y. Wu, Y. L. Pan, X. J. Zhang, T. Sun, Y. P. Tian, J. X. Yang
and Z. N. Chen, Inorg. Chim. Acta, 2007, 360, 2083; (b) S. W. Cha and
J. I. Jin, J. Mater. Chem., 2003, 13, 479.
8 K. Albrecht, Y. Kasai, A. Kimoto and K. Yamamoto,
Macromolecules, 2008, 41, 3793.
9 S. K. Kim, B. Yang, Y. G. Ma, J. H. Lee and J. W. Park, J. Mater.
Chem., 2008, 18, 3376.
10 Z. J. Ning, Z. Chen, Q. Zhang, Y. L. Yan, S. X. Qian, Y. Cao and
H. Tian, Adv. Funct. Mater., 2007, 17, 3799.
5546 | J. Mater. Chem., 2009, 19, 5541–5546
This journal is ª The Royal Society of Chemistry 2009