Synthesis and characterization of deep blue emitters from starburst carbazole/fluorene compounds

Article abstract of DOI:10.1016/j.tet.2007.12.059

A series of well-defined, highly fluorescent starburst compounds with a carbazole core and oligo(2,7-fluorene ethynylene) arms have been synthesized by Sonogashira coupling reaction and fully characterized. These conjugated compounds exhibit good solubility, high thermal stability, and excellent fluorescence quantum yields (up to 0.99). The incorporation of carbazole core interrupted the main-chain conjugation and resulted in blue-shifted absorption and emission. Moreover, deep blue light has been approached from organic light-emitting diodes (OLEDs) adopting these compounds as emitting layer.

Full text of DOI:10.1016/j.tet.2007.12.059

Available online at www.sciencedirect.com
Tetrahedron 64 (2008) 2658e2668
www.elsevier.com/locate/tet
Synthesis and characterization of deep blue emitters
from starburst carbazole/fluorene compounds
b
b,
Zujin Zhao a, Xinjun Xu b, Xiaopeng Chen a, Xiaoming Wang a, Ping Lu a, , Gui Yu , Yunqi Liu
*
*
a Department of Chemistry, Zhejiang University, Hangzhou 310027, PR China
b Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China
Received 21 September 2007; received in revised form 18 December 2007; accepted 21 December 2007
Available online 8 January 2008
Abstract
A series of well-defined, highly fluorescent starburst compounds with a carbazole core and oligo(2,7-fluorene ethynylene) arms have been
synthesized by Sonogashira coupling reaction and fully characterized. These conjugated compounds exhibit good solubility, high thermal sta-
bility, and excellent fluorescence quantum yields (up to 0.99). The incorporation of carbazole core interrupted the main-chain conjugation and
resulted in blue-shifted absorption and emission. Moreover, deep blue light has been approached from organic light-emitting diodes (OLEDs)
adopting these compounds as emitting layer.
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords: Blue emitter; Starburst molecules; Photoluminescence; Electroluminescence
1. Introduction
satisfactory due to their large energy gaps and low electron affin-
ities leading to inefficient electron injection into the blue
emitters.
Since the development of first efficient OLEDs by Tang and
VanSlyke,1 significant attention has been paid on the produc-
tion of full-color flat panel displays.2,3 Full-color displays
based on OLEDs exhibit many attractive features, such as
wide viewing angles, bright self-emission, facile color tunabil-
ity, and compatibility with flexible substrates and now exist in
a range of commercial applications and compete with conven-
tional liquid-crystal displays (LCDs).4e7 To realize full-color
OLED displays, highly efficient red-, green-, and blue-emit-
ting materials and devices are required. However, only red
and green materials and devices with sufficient efficiencies
and lifetimes of commercial value have been described,8e11
while high-efficient, pure blue light still remains a challenge.
Consequently, a great number of blue-emitting materials,
such as anthracene derivatives,12e15 oligoquinoline,16 tetra-
phenylsilane,17,18 and diarylfluorene derivatives19,20 have been
developed. However, most of these materials are still not
Monodisperse oligofluorenes, first reported by Klaerner and
Miller,21 have recently attracted much attention because of
their excellent chemical, thermal, photochemical stabilities
as well as the possibility of structure tuning to adjust the
electronic and morphological properties of desired compounds
via the substitution on the C-9 position of fluorene.22,23 Not
only does this class of materials have great potential applica-
tions for optoelectronic materials, such as blue emitters of
OLEDs,24,25 but also it would be very helpful to study the
properties of a series of pure compounds and to have a better
understanding of the structureeproperty relationships of their
corresponding polymers. On the other hand, carbazole units
hold hole-transport ability and incorporation of them could
improve the hole-transport properties of materials as well as
suppress the aggregation and/or excimers formation of mole-
cules.26e29 In this report, carbazole units were successfully
introduced into fluorene compounds through 3-, 6-, and/or
9-positions of carbazole. Thus, linear and starburst structures
of molecules were obtained (Scheme 1). These synthesized
compounds emitted deep blue light with high quantum yields
* Corresponding authors. Tel./fax: þ86 571 879 52543.
E-mail address: pinglu@zju.edu.cn (P. Lu).
0040-4020/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2007.12.059

Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
2659
N
N
Cz2F
C7H15
C7H15
N
N
Cz2F3
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
N
Cz2F5
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
N
N
CzF6
Cz3F4
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
N
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
N
CzF9
Cz4F6
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
N
Scheme 1. Chemical structures of carbazole/fluorene compounds.
and their applications in blue OLEDs were investigated
accordingly.
diethynyl-9-(4-ethynylphenyl)-9H-carbazole (12), which served
as a core of starburst molecules, was prepared by coupling 10
with 3-methyl-1-butyn-3-ol, and subsequently by deprotec-
tion. Fluorene derivatives 13 and 1833 were used to construct
the main chain of these conjugated molecules. Pd/Cu-cata-
lyzed coupling of 4 with an excess amount of 13 yielded
intermediate 14, which could be coupled with 3-methyl-1-bu-
tyn-3-ol in the presence of Pd/Cu catalyst and subsequently
base-promoted deprotection to provide compound 16. Recou-
pling of 16 with an excess amount of 13 afforded 17, which
served as arms of starburst compounds. Similar procedures
were performed to obtain 19.33 Coupling of 2,7-diethynyl-
9,9-diheptyl-9H-fluorene (18) with 2 equiv of 2, 14, and 17
offered linear compounds Cz2F, Cz2F3, and Cz2F5 in
moderate yields of 86, 78, and 72% after separation, respec-
tively. Furthermore, treatment of 3,6-diethynyl-9-p-tolyl-9H-
2. Results and discussion
2.1. Synthesis
Structures of these well-defined, carbazole end-capped and/
or centered fluorene compounds are illustrated in Scheme 1. A
Pd/Cu-catalyzed Sonogashira coupling reaction was used as
a key reaction to construct these triple-bond-linked com-
pounds. Scheme 2 illustrates the synthetic routes to intermedi-
ates and final compounds. Our synthetic strategy started from
commercially available compounds carbazole and fluorene.
The cabazole derivatives 1e830,31 and 9 and 1032 were synthe-
sized according to the reference methods. Compound 3,6-

2660
Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
I
I
OH
N
I
N
N
R
3 R =
4 R =
I
N
13
d
c
b
a
C7H15C7H15
H
C7H15 C7H15
N
H
i
14
2
1
4
I
I
R
R
OH
N
7 R =
8 R =
N
c
d
f
c
OH
N
15 R=
16 R =
e
R
N
d
H
6
H
N
H
C7H15 C7H15
5
I
I
R
R
OH
g
f
h
11 R =
12 R =
I
I
N
d
N
N
13
C7H15C7H15
I
N
H
9
10
i
C7H15
C7H15
C7H15
17
C7H15
Br
Br
R
i
i
N
I
N
I
Cz2F3
+
+
Cz2F
C7H15 C7H15
C7H15
C7H15 C7H15
C7H15
2
18
14
18
18
C7H15 C7H15
Cz2F5
N
8
N
CzF6
8
i
Cz3F4
N
I
i
I
N
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15
C7H15 C7H15
C7H15
C7H15
12
N
17
19
CzF9
12
Cz4F6
Scheme 2. Conditions: (a) (CH3)3CCl, AlCl3, CH2Cl2; (b) K2CO3, Cu, 18-crown-6, 1,4-diiodobenzene, DMF, N2, 170 ꢀC; (c) 3-methyl-1-butyn-3-ol, Pd(PPh3)2Cl2,
PPh3, CuI, NEt3, reflux; (d) KOH, 2-propanol, reflux; (e) K2CO3, Cu, 18-crown-6, 1-iodo-4-methylbenzene, DMF, N2, 170 ꢀC; (f) KI, KIO3, acetic acid, 80 ꢀC; (g)
K2CO3, Cu, 18-crown-6, 1-bromo-4-iodobenzene, DMF, N2, 170 ꢀC; (h) 3-methyl-1-butyn-3-ol, Pd(Ph3P)4, Ph3P, CuI, diisopropylamine, N2, reflux; (i)
Pd(PPh3)2Cl2, PPh3, CuI, NEt3, reflux.
carbazole (8) with 2 equiv of 19 and 17 provided Cz6F, and
Cz3F4 in 69 and 65% yields, respectively. Finally, CzF9 and
Cz4F6 were synthesized by the reactions of 3,6-diethynyl-9-
(4-ethynylphenyl)-9H-carbazole (12) with 3 equiv of 19 and
17, respectively, in the presence of Pd/Cu catalyst.
structures of compounds. Although the chains of all molecules
were composed of fluorene units, the arrangement of fluorene
units was quite interesting. Cz2F3 and Cz2F5, end-capped
with carbazole units, have rod-like structures and the fluorene
units arranged alternatively in two different directions in back-
bones, which was in a good accordance with the arrangement
of fluorene in its homopolymer. However, both CzF6 and
Cz3F4, with V-shaped structures, presented the arrangement
of fluorene in one direction. This phenomenon could also
be observed in the propeller-like structures of CzF9 and
Cz4F6. From Figure 1, we inferred that it was much easier
for small and linear molecule Cz2F to form close molecular
packing than other compounds. The multifeasibility of the
free rotation along the molecular chain and the steric hin-
drance arising from the centered carbazole hampered the close
packing of the aromatic rings and thereafter hindered the ag-
gregation and/or excimer formation.
All compounds appeared to be yellow powder after dried in
vacuum. Structures of the target compounds were character-
ized by NMR, MALDI-TOF mass spectroscopy, and element
analysis. These compounds exhibited excellent solubility in
common organic solvents, such as CH2Cl2, CHCl3, THF, tol-
uene, and even cyclohexane, which was ascribed to the exis-
tence of n-heptyl and tert-butyl substituents. Existence of
alkyl substituents not only benefited the easier preparation
and purification of compounds, but also helped the device fab-
rication via simple spin-coating. Further, these compounds
showed good thermal stabilities, and their decomposition tem-
peratures (Td, 5% loss of initial weight) were above 400 ꢀC
examined by thermogravimetric analysis (TGA) in N2 at
a heating rate of 20 ꢀC minꢁ1. The melting and glass transition
temperatures were not clearly observed by differential scan-
ning calorimetry (DSC).
2.3. Photophysical properties
The photophysical properties of these compounds were ex-
amined by UVevis and fluorescence spectroscopy in dichloro-
methane solutions and in thin neat films as well. Figure 2
shows the normalized UVevis absorption spectra. In dilute di-
chloromethane solutions, all the compounds exhibited struc-
tureless absorption bands arising from the pep* transition
2.2. Visualization and simulation
Structures of the synthesized compounds were optimized
by PM3 method. Figure 1 illustrates the energy-minimized

Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
2661
Figure 1. Energy-minimized structures of compounds calculated by PM3.
of the molecular chain. The maximum absorption peaks of lin-
ear compounds (Cz2F, Cz2F3, and Cz2F5) bathochromically
shifted with the increase of molecular length. The V-shaped
and the starburst compounds exhibited almost identical ab-
sorption bands with maximum absorption peaks at about
400 nm. The carbazole at the center of the molecules interrup-
ted the main-chain conjugation34 and resulted in relatively
short absorption wavelength with respect to that of Cz2F5.
In thin neat films, the absorption spectra of these compounds
were quite similar to those in solutions except for slightly
red shifts (1e5 nm), which indicated that these compounds ex-
hibited very similar conformations in both solution and solid
states. The pep* energy gaps (Eg, Table 1) of these com-
pounds were calculated from the UVevis absorption thresh-
olds. The Egs increased progressively with the decrease of
the chain length. The Egs of the V-shaped and the starburst
compounds were 2.97 eV, which were higher than that of
Cz2F5. This was also attributed to the different conjugation
degree of molecules with or without centered carbazole core,
which could result in different energy levels.35 From Table
1, it was observed that the molar absorption coefficient be-
came larger with the increase of the conjugation length or
the number of arms. Moreover, carbazole end-capped com-
pounds seemed to have relatively larger molar absorption
coefficient compared with those of similar molecules without
carbazole cappers.
Figure 3 displays the emission spectra of compounds in
dilute CH2Cl2 solutions and in thin neat films as well, excited
at 380 nm. Cz2F3 and Cz2F5 showed narrow emission spectra
with a full width at half emission maximum (fwhm) of 14 nm
and emission peaks located at 417 and 421 nm, respectively.
Expectably, the shortest compound (Cz2F) exhibited a red-
shifted, broad emission peak at 422 nm with a fwhm of
65 nm, which was ascribed the excimers formation as
we assumed above. Much energy loss observed from the
largest Stokes shift (52 nm) was well evident. In view of

2662
Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
(a)
(b)
1.2
Cz2F
1.0
0.8
0.6
0.4
0.2
0.0
CzF6
Cz2F3
Cz3F4
CzF9
1.0
Cz2F5
Cz4F6
0.8
0.6
0.4
0.2
0.0
300
350
400
Wavelength (nm)
450
500
300
350
400
Wavelength (nm)
450
500
(c)
(d)
1.0
0.8
0.6
0.4
0.2
0.0
1.0
0.8
0.6
0.4
0.2
0.0
Cz2F
CzF6
Cz3F4
CzF9
Cz2F3
Cz2F5
Cz4F6
300
350
400
Wavelength (nm)
450
500
300
350
400
Wavelength (nm)
450
500
Figure 2. Absorption spectra of compounds in dilute CH2Cl2 solutions (a), (b), and in thin neat films (c), (d).
carbazole-centered molecules, their emission spectra were
almost the same. Main emission peaks were located at about
415 nm with shoulder peaks at about 440 nm, which were
close to those of reported polyfluorenes (415 and 439 nm).36
Similar to the observation in solutions, Cz2F exhibited broad,
red-shifted emission in thin neat film due to the excimer
formation. Emission spectra in thin neat films of other com-
pounds were resembled to those in solutions except for slight
red shifts (ꢂ6 nm).
increased as the chain lengths elongated. These findings
were much better than those of oligo(2,7-fluorene ethynyl-
ene)s without carbazole participation (0.49e0.63).33 Remark-
ably, high quantum yields (0.97e0.99) were observed for
those starburst compounds with centered carbazole core,
which were higher than those of compounds with similar effi-
cient conjugation length.34 For example, the quantum yield of
Cz4F6 was 0.99, while those of Cz2F and Cz2F3 were 0.74
and 0.89, respectively. Similar phenomena have been reported
by Yamaguchi et al.,40 which was ascribed to an extension of
the p conjugation between the arms of starburst molecules.
From higher PL quantum yields as well as larger molar ab-
sorption coefficient of starburst compounds, we inferred that
the insertion of carbazole core into the molecular backbone
The synthesized compounds were highly fluorescent in
solutions and in solid states. Quantum yields were measured
in degassed cyclohexanes using the standard of 9,10-diphenyl-
anthrecene (DPA, F¼0.95 in cyclohexane).37e39 Those of
linear ones were measured in the range of 0.74e0.96, which
Table 1
Photophysical properties of compounds
b
lEm. (nm)
e
Compound
lAbs. (nm)
Fc
fwhmd
(nm)
Stokes
shift (nm)
Eg
(eV)
Td
(nm)
(ꢀC)
CH2Cl2 (3ꢃ105)a
370 (0.97)
Film
CH2Cl2
Film
Cz2F
Cz2F3
Cz2F5
CzF6
CzF9
Cz3F4
Cz4F6
a
369
422
411, 447
423, 448
427, 452
419, 446
420, 444
421, 444
419, 443
0.74
0.89
0.96
0.97
0.99
0.98
0.99
65
14
14
16
16
20
16
52
16
12
13
14
15
14
3.02
2.93
2.90
2.97
2.97
2.97
2.97
413
420
419
415
411
421
416
385 (2.20), 401 (1.97)
391 (3.45), 409 (3.32)
381 (3.10), 402 (2.63)
382 (4.56), 401 (4.09)
382 (4.26), 400 (3.95)
382 (5.64), 400 (5.25)
383, 406
387, 410
381, 405
383, 404
382, 404
383, 402
417, 447
421, 446
415, 440
415, 439
415, 440
414, 439
Molar absorption coefficient (3): Mꢁ1 cmꢁ1
.
b
c
d
e
Excited at 380 nm.
Measured in cyclohexane solutions using DPA as a standard.
Full width at half emission maximum in dilute CH2Cl2 solutions (w10ꢁ6 M).
Determined from UVevis absorption spectra.

Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
2663
(a)
(b)
1.0
0.8
0.6
0.4
0.2
0.0
1.0
Cz2F
CzF6
Cz2F3
Cz3F4
CzF9
0.8
Cz2F5
Cz4F6
0.6
0.4
0.2
0.0
350
400
450
Wavelength (nm)
500
550
600
350
400
450 500
Wavelength (nm)
550
600
(c)
(d)
1.0
1.0
0.8
0.6
0.4
0.2
0.0
CzF6
Cz2F
Cz3F4
CzF9
Cz2F3
Cz2F5
0.8
0.6
0.4
0.2
0.0
Cz4F6
350
400
450
500
550
Wavelength (nm)
600
650
700
350
400
450
500
550
Wavelength (nm)
600
650
700
Figure 3. PL spectra of compounds in dilute CH2Cl2 solutions (a), (b), and in thin neat films (c), (d).
might not interrupt the main-chain conjugation completely,
and a weak p conjugation still occurred between arms.
densityevoltageebrightness characteristic curves and Table 2
summarizes the performance of devices based on these com-
pounds. The EL spectra were similar to PL spectra in thin
neat films, which indicated the same radiative decay process
of singlet excitons.41,42 In view of linear compounds, Cz2F
and Cz2F3 showed broad emission peaks with additional emis-
sions around 500 nm. This could be ascribed to the enhanced
excimer formation of these short chains that were prone to align
under electric fields.43,44 Cz2F5, with longer chain length, ex-
hibited EL emission peaks at 428 and 452 nm with a fwhm of
75 nm. No excimer emission was observed in this case. Further,
compounds with a carbazole core, except for Cz4F6 whose EL
emission was unstable, exhibited similar narrow emission with
fwhms in the range of 72e89 nm. The preliminary results dem-
onstrated that deep blue light could be approached from the
devices based on Cz2F5 and carbazole-centered compounds
2.4. Electroluminescence properties
To investigate the EL properties of these compounds, devices
with the configurations of indium tin oxides (ITO)/poly(3,4-eth-
ylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)
(30 nm)/compounds (50 nm)/1,3,5-tris(N-phenylbenzimid-
azol-2-yl)benzene (TPBI) (20 nm)/Al (100 nm), were fabricated.
PEDOT:PSS were used as a hole-injection layer, TPBI was
adopted as an electron-transporting and hole-blocking layer,
and the synthesized compounds functioned as light-emitting
layers. EL spectra as well as current densityevoltageebright-
ness characteristics were measured under ambient conditions.
Figures 4e6 illustrate the normalized EL spectra and current
(a)
(b)
1.0
1.0
CzF6
Cz2F
Cz2F3
Cz3F4
0.8
0.8
CzF9
Cz2F5
0.6
0.6
0.4
0.2
0.0
0.4
0.2
0.0
350 400 450 500 550 600 650 700 750
Wavelength (nm)
350 400 450 500 550 600 650 700 750
Wavelength (nm)
Figure 4. EL spectra of compounds in devices: ITO/PEDOT:PSS/compounds/TPBI/Al.

2664
Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
(a)
(b)
CzF6
Cz2F
400
300
200
100
0
Cz2F3
Cz2F5
Cz3F4
300
CzF9
200
100
0
0
2
4
6
8
Voltage (V)
10 12 14 16
0
2
4
6
Voltage (V)
8
10
12
Figure 5. Brightnessevoltage diagrams for device: ITO/PEDOT:PSS/compounds/TPBI/Al.
(a)
(b)
CzF6
Cz2F
200
150
100
50
200
150
100
50
Cz3F4
CzF9
Cz2F3
Cz2F5
0
0
0
2
4
6
Voltage (V)
8
10
12
0
2
4
6
Voltage (V)
8
10 12 14 16
Figure 6. Current densityevoltage diagrams for devices: ITO/PEDOT:PSS/compounds/TPBI/Al.
Table 2
Summary of device performances
4. Experimental section
Compound EL (nm)
fwhm hmax, ext hmax, L Turn-on Brightnessmax
(cd Aꢁ1) voltage (cd mꢁ2, V)
(V)
4.1. General information
(nm) (%)
1H and 13C NMR spectra were obtained on a Bruker
AVANCE DMX500 spectrometer operating in the FT mode.
Solutions in chloroform-d (5% w/v) were used to obtain
NMR spectra. TMS was used as an internal standard. Mass
spectroscopic (MS) measurements were carried using matrix-
assisted laser desorptioneionization time-of-flight (MALDI-
TOF) technique. Fluorescence measurements were made with
a RF-5301PC spectrofluorometer (Shimadzu, Kyoto, Japan)
equipped with a xenon lamp. UVevis absorption spectra
were recorded on Shimadzu UV-2450 spectrophotometer.
NETZSCH STA 409 PG/PC was used to measure the thermal
performances of the compounds. The solvents were distilled
before used. Commercially available reagents were used with-
out further purification.
Cz2F
468, 492 98 0.34
432, 468, 502 126 0.40
0.63
0.76
0.52
0.39
0.34
0.23
7.4
7.6
5.2
6.1
6.1
4.2
421, 13
155, 12.5
296, 9.0
230, 9.0
221, 9.0
222, 8.0
Cz2F3
Cz2F5
CzF6
428, 452
424, 448
424, 448
420, 448
75 0.44
89 0.30
72 0.31
72 0.21
Cz3F4
CzF9
(Cz3F4 and CzF9). Introduction of carbazole units into molec-
ular backbone led to the color-stable, blue-shifted emission by
suppressing excimers formation.
3. Conclusions
In summary, we had successfully synthesized and fully
characterized a series of well-defined, highly fluorescent com-
pounds with a carbazole core and oligo(2,7-fluorene ethynyl-
ene) arms. Addition of carbazole units significantly
increased the fluorescence quantum yields in comparison
with those of oligo(2,7-fluorene ethynylene)s, especially for
carbazole-centered compounds. Moreover, participation of
carbazole interrupted the conjugation and resulted in blue-
shifted absorption and emission. Furthermore, deep blue light
had been approached from OLEDs based on these compounds
as emitters.
4.2. 3,6-Diethynyl-9-(4-ethynyl-phenyl)-9H-carbazole (12)
Compound 10 (2.87 g, 5 mmol), 3-methyl-1-butyn-3-ol
(1.68 g, 20 mmol), cuprous iodide (20 mg, 0.1 mmol), Pd(Ph3P)4
(11.5 mg, 0.01 mmol), triphenylphosphine (10.5 mg, 0.04 mmol),
and dry diisopropylamine (150 mL) were placed in a 250 mL
round bottle flask equipped with a Teflon covered magnetic stir
bar. After the solution was purged with nitrogen for half an

Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
2665
hour, it was refluxed under nitrogen for 12 h. The reaction
mixture was filtered and the filtrate was evaporated under
reduced pressure. Compound 11 was obtained through col-
umn chromatography (silica gel, hexane/ethyl acetate as
eluent). Then 11, potassium hydroxide (2.0 g, 35 mmol),
and 2-propanol (150 mL) were placed in 250 mL round bot-
tle flask equipped with a Teflon covered magnetic stir bar.
After the resulting mixture was refluxed for 3 h under N2,
it was cooled to room temperature. Solution was poured
into water and extracted by CH2Cl2. After washing by water
and drying by MgSO4, the solvent was then removed, and the
residue was purified through column chromatography (silica
gel, hexane/dichloromethane as eluent). In this way, 1.2 g
0.02 mmol), and dry triethylamine (150 mL) were placed in
a 250 mL round bottle flask equipped with a Teflon covered
magnetic stir bar. After the solution was purged with nitro-
gen for half an hour, it was refluxed under nitrogen for
12 h. The reaction mixture was filtered and the filtrate was
evaporated under reduced pressure. The residue was purified
through column chromatography (silica gel, hexane/dichloro-
methane/ethyl acetate as eluent) to afford 15. Then 15, potas-
sium hydroxide (2.0 g, 35 mmol), and 2-propanol (150 mL)
were placed in 250 mL round bottle flask equipped with
a Teflon covered magnetic stir bar. After the resulting mix-
ture was refluxed for 3 h under N2, it was cooled to room
temperature. Solution was poured into water and extracted
by CH2Cl2. After washing by water and drying by MgSO4,
the solvent was then removed, and the residue was purified
through column chromatography (silica gel, hexane/dichloro-
1
(72 % total yield) of 12 was obtained. H NMR d CDCl3:
3.10 (s, 2H), 3.20 (s, 1H), 7.32 (d, 2H, J¼8.5 Hz), 7.50
(d, 2H, J¼8.5 Hz), 7.55 (dd, 2H, J1¼8.5 Hz, J2¼1.5 Hz),
7.73 (d, 2H, J¼8.5 Hz), 8.26 (d, 2H, J¼1.0 Hz) ppm; 13C
NMR d CDCl3: 76.17, 78.83, 82.83, 84.58, 110.18, 114.50,
122.20, 123.16, 124.99, 127.04, 130.80, 134.10, 137.30,
141.03 ppm; MS (EI) (m/z): 315 (Mþ). Anal. Calcd for
C24H13N: C, 91.40; H, 4.15; N, 4.44. Found: C, 91.41; H,
4.13; N, 4.38.
1
methane as eluent). Yield 62%. H NMR d CDCl3: 0.61e
0.62 (m, 4H), 0.81(t, 6H, J¼7.5 Hz), 1.06 (br, 12H),
1.17e1.21 (m, 4H), 1.47 (s, 18H), 1.96e1.99 (m, 4H),
3.15 (s, 1H), 7.39 (d, 2H, J¼9.0 Hz), 7.47e7.50 (m, 4H),
7.54e7.58 (m, 4H), 7.65 (d, 1H, J¼7.5 Hz), 7.68 (d, 1H,
J¼8.0 Hz), 7.76 (d, 2H, J¼8.5 Hz), 8.14 (d, 2H,
J¼1.0 Hz) ppm; 13C NMR d CDCl3: 14.29, 22.83, 23.99,
29.22, 30.23, 32.05, 32.25, 35.01, 40.55, 55.52, 77.57,
84.85, 89.48, 91.38, 109.47, 116.56, 120.19, 120.36,
121.02, 121.97, 122.20, 123.86, 123.98, 126.29, 126.67,
128.82, 131.07, 131.54, 133.23, 138.36, 139.17, 140.93,
141.40, 143.47, 151.32, 151.45 ppm; MS (MALDI-TOF)
(m/z): 763.9 (Mþ). Anal. Calcd for C57H65N: C, 89.59; H,
8.57; N, 1.83. Found: C, 89.60; H, 8.55; N, 1.80.
4.3. 3,6-Di-tert-butyl-9-[4-(9,9-diheptyl-7-iodo-9H-fluoren-2-
ylethynyl)-phenyl]-9H-carbazole (14)
Compound 4 (379 mg, 1 mmol), 13 (1842 mg, 3 mmol), cu-
prous iodide (10 mg, 0.05 mmol), Pd(PPh3)2Cl2 (3.5 mg,
0.005 mmol), triphenylphosphine (5 mg, 0.02 mmol), and dry
triethylamine (150 mL) were placed in a 250 mL round bottle
flask equipped with a Teflon covered magnetic stir bar. After
the solution was purged with nitrogen for half an hour, it
was refluxed under nitrogen for 4 h. The reaction mixture
was filtered and the filtrate was evaporated under reduced pres-
sure. The residue was purified through column chromatogra-
phy (silica gel, hexane/dichloromethane as eluent). In this
way, 623 mg (72 % yield) of 14 was obtained. 1H NMR
d CDCl3: 0.62 (br, 4H), 0.80 (t, 6H, J¼7.5 Hz), 1.06e1.07
(m, 12H), 1.16e1.20 (m, 4H), 1.47 (s, 18H), 1.95e2.00
(m, 4H), 7.34 (d, 2H, J¼6.5 Hz), 7.39 (d, 2H, J¼8.0 Hz),
7.47e7.49 (m, 2H), 7.55e7.58 (m, 4H), 7.65e7.70 (m, 2H),
7.75e7.77 (m, 2H), 8.14 (d, 2H, J¼1.5 Hz) ppm; 13C NMR
d CDCl3: 14.28, 22.82, 24.00, 29.21, 30.26, 32.04, 32.23,
34.99, 40.61, 55.40, 89.02, 91.57, 93.42, 109.46, 116.54,
119.92, 120.08, 120.27, 121.93, 123.16, 123.81, 123.96,
126.25, 126.65, 127.14, 127.81, 130.89, 132.37, 133.20,
136.26, 139.12, 141.87, 143.44, 151.30, 153.67 ppm; MS
(MALDI-TOF) (m/z): 739.7 (MþꢁI). Anal. Calcd for
C55H64IN: C, 76.28; H, 7.45; I, 14.65; N, 1.62. Found: C,
76.25; H, 7.49; N, 1.58.
4.5. 3,6-Di-tert-butyl-9-{4-[7-(9,9-diheptyl-7-iodo-9H-
fluoren-2-ylethynyl)-9,9-diheptyl-9H-fluoren-2-ylethynyl]-
phenyl}-9H-carbazole (17)
The procedure is analogous to that described for 14. Yield
1
58%. H NMR d CDCl3: 0.62 (br, 8H), 0.80e0.83 (m, 12H),
1.06e1.07 (m, 24H), 1.17e1.21 (m, 8H), 1.47 (s, 18H),
1.93e1.97 (m, 4H), 2.00e2.03 (m, 4H), 7.39e7.45 (m, 3H),
7.48 (dd, 2H, J1¼8.5 Hz, J2¼1.5 Hz), 7.53e7.59 (m, 8H),
7.65e7.71 (m, 5H), 7.77 (d, 2H, J¼8.5 Hz), 8.15 (d, 2H,
J¼1.5 Hz) ppm; 13C NMR d CDCl3: 22.84, 23.94, 24.02,
29.20, 29.28, 30.19, 30.28, 32.05, 32.09, 32.25, 35.00,
40.54, 40.70, 55.54, 55.67, 89.47, 90.97, 91.03, 91.43,
93.37, 109.46, 116.55, 120.09, 120.27, 120.31, 121.92,
121.96, 122.02, 122.27, 122.43, 123.98, 126.13, 126.20,
126.52, 126.66, 131.01, 131.07, 132.34, 133.22, 136.25,
138.32, 139.14, 140.35, 140.61, 140.92, 141.13, 143.44,
150.49, 151.41, 153.64 ppm; MS (MALDI-TOF) (m/z):
1250.1 (Mþ). Anal. Calcd for C84H100IN: C, 80.67; H, 8.06;
I, 10.15; N, 1.12. Found: C, 80.70; H, 8.10; N, 1.10.
4.4. 3,6-Di-tert-butyl-9-[4-(7-ethynyl-9,9-diheptyl-9H-
fluoren-2-ylethynyl)-phenyl]-9H-carbazole (16)
4.6. 2-((9,9-Diheptyl-7-iodo-9H-fluoren-2-yl)ethynyl)-7-((9,9-
diheptyl-9H-fluoren-2-yl)ethynyl)-9,9-diheptyl-9H-fluorene (19)
Compound 14 (866 mg, 1 mmol), 3-methyl-1-butyn-3-ol
(168 mg, 2 mmol), cuprous iodide (10 mg, 0.05 mmol),
Pd(PPh3)2Cl2 (3.5 mg, 0.005 mmol), triphenylphosphine (5 mg,
The procedure is analogous to that described for 17. Yield
77%. 1H NMR d CDCl3: 0.61 (br, 12H), 0.78e0.83 (m, 18H),

2666
Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
1.06 (br, 36H), 1.17e1.18 (m, 12H), 1.94e2.02 (m, 12H),
7.33e7.34 (m, 3H), 7.44 (d, 1H, J¼8.0 Hz), 7.52e7.58 (m,
8H), 7.66e7.71 (m, 7H) ppm; 13C NMR d CDCl3: 14.29,
14.31, 22.83, 23.92, 23.98, 29.20, 29.24, 29.28, 30.18,
30.26, 32.04, 32.08, 40.54, 40.69, 40.75, 55.38, 55.50,
55.65, 90.60, 90.91, 91.05, 91.18, 93.38, 119.91, 120.08,
120.24, 121.63, 121.91, 122.12, 122.35, 122.41, 123.10,
126.10, 126.15, 127.11, 127.76, 130.81, 130.96, 132.30,
136.23, 140.33, 140.58, 140.65, 140.83, 141.00, 141.69,
150.45, 151.02, 151.24, 151.31, 151.34, 153.62 ppm; MS
(MALDI-TOF) (m/z): 1256.9 (Mþ). Anal. Calcd for
C85H109I: C, 81.17; H, 8.74; I, 10.09. Found: C, 81.19; H,
8.71.
13C NMR d CDCl3: 14.29, 22.85, 24.04, 29.28, 30.29, 32.09,
32.26, 35.01, 40.71, 55.57, 89.48, 91.08, 91.12, 91.47,
109.47, 116.57, 120.27, 122.01, 122.04, 122.29, 122.35,
123.86, 123.99, 126.23, 126.27, 126.68, 131.03, 131.09,
133.23, 138.35, 139.17, 140.93, 140.99, 141.16, 143.47,
151.43 ppm; MS (MALDI-TOF) (m/z): 1886.3 (Mþ). Anal.
Calcd for C141H164N2: C, 89.75; H, 8.76; N, 1.48. Found: C,
89.75; H, 8.75; N, 1.47.
4.7.3. 9,90-(4,40-(7,70-(7,70-(9,9-Diheptyl-9H-fluorene-2,7-
diyl)bis(ethyne-2,1-diyl)bis(9,9-diheptyl-9H-fluorene-7,2-
diyl))bis(ethyne-2,1-diyl)bis(9,9-diheptyl-9H-fluorene-7,2-
diyl))bis(ethyne-2,1-diyl)bis(4,1-phenylene))bis(3,6-di-tert-
butyl-9H-carbazole) (Cz2F5)
1
4.7. General procedure for the synthesis of the compounds
Yield 72 %. H NMR d CDCl3: 0.64 (br, 20H), 0.80e0.83
(Cz2F, Cz2F3, Cz2F5, CzF6, Cz3F4, CzF9, and Cz4F6)
(m, 30H), 1.08 (br, 60H), 1.18e1.20 (m, 20H), 1.47 (s, 36H),
2.02 (br, 20H), 7.40 (d, 4H, J¼8.5 Hz), 7.49 (dd, 4H,
J1¼8.5 Hz, J2¼2.0 Hz), 7.56e7.59 (m, 24H), 7.70e7.72 (m,
10H), 7.78 (d, 4H, J¼8.5 Hz), 8.15 (d, 4H, J¼1.5 Hz) ppm;
13C NMR d CDCl3: 14.29, 22.84, 24.01, 29.29, 30.28, 32.08,
32.24, 35.00, 40.69, 40.76, 55.53, 75.90, 85.95, 89.45,
91.07, 91.43, 116.54, 120.27, 120.30, 121.95, 121.99,
122.23, 122.29, 123.81, 123.97, 126.17, 126.65, 131.01,
131.06, 133.22, 138.30, 139.12, 140.90, 140.96, 141.13,
143.43, 151.36, 151.40 ppm; MS (MALDI-TOF) (m/z):
2656.3 (Mþ). Anal. Calcd for C199H236N2: C, 89.99; H,
8.96; N, 1.05. Found: C, 90.00; H, 9.00; N, 0.99.
These compounds were obtained following an essentially
similar procedure. An illustrative example is provided
for Cz2F: 3,6-di-tert-butyl-9-(4-iodophenyl)-9H-carbazole (2)
(962 mg, 2 mmol), 2,7-diethynyl-9,9-diheptyl-9H-fluorene (18)
(410 mg,1 mmol),cuprousiodide(10 mg,0.05 mmol),dichloro-
bis(triphenylphosphine)palladium (II) (3.5 mg, 0.005 mmol),
triphenylphosphine (5 mg, 0.02 mmol), and dry triethylamine
(100 mL) were placed in a 150 mL round bottle flask equipped
with a Teflon covered magnetic stir bar. After the solution was
purged with nitrogen for half an hour, it was refluxed under nitro-
gen for 4 h. The reaction mixture was filtered and the filtrate was
evaporated under reduced pressure. The residue was purified
through column chromatography (silica gel, hexane/dichlorome-
thane as eluent) to get Cz2F (960 mg, 86% yield).
4.7.4. 3,6-Bis((7-((7-((9,9-diheptyl-9H-fluoren-2-
yl)ethynyl)-9,9-diheptyl-9H-fluoren-2-yl)ethynyl)-9,9-
diheptyl-9H-fluoren-2-yl)ethynyl)-9-p-tolyl-9H-carbazole
(CzF6)
4.7.1. 9,90-(4,40-(9,9-Diheptyl-9H-fluorene-2,7-diyl)
bis(ethyne-2,1-diyl)bis(4,1-phenylene))bis(3,6-di-tert-
butyl-9H-carbazole) (Cz2F)
Yield 69%. 1H NMR d CDCl3: 0.63e0.64 (m, 24H), 0.78e
0.83 (m, 36H), 1.05e1.08 (m, 72H), 1.15e1.20 (m, 24H),
1.98e2.03 (m, 24H), 2.51 (s, 3H), 7.33e7.37 (m, 8H), 7.45
(d, 4H, J¼2.5 Hz), 7.55e7.61 (m, 20H), 7.65 (dd, 2H,
J1¼8.0 Hz, J2¼1.5 Hz), 7.69e7.71 (m, 12H), 8.38 (d, 2H,
J¼1.0 Hz) ppm; 13C NMR d CDCl3: 14.28, 21.54, 22.82,
22.85, 24.02, 29.24, 29.29, 30.28, 30.30, 32.06, 32.09,
40.69, 40.76, 55.41, 55.54, 89.39, 90.64, 91.02, 91.11,
91.13, 91.18, 110.44, 115.21, 119.91, 120.24, 121.64,
122.12, 122.26, 122.37, 122.68, 123.13, 123.19, 124.28,
126.13, 126.19, 127.13, 127.17, 127.76, 130.22, 130.84,
130.92, 130.98, 134.42, 138.38, 140.67, 140.70, 140.88,
140.99, 141.09, 141.36, 141.71, 151.05, 151.28, 151.38 ppm;
MS (MALDI-TOF) (m/z): 2564.5 (Mþ). Anal. Calcd for
1
Yield 86%. H NMR d CDCl3: 0.67 (br, 4H), 0.82 (t, 6H,
J¼7.5 Hz), 1.10 (br, 12H), 1.18e1.22 (m, 4H), 1.47 (s,
36H), 2.01e2.05 (m, 4H), 7.40 (d, 4H, J¼8 Hz), 7.48
(dd, 4H, J1¼8.5 Hz, J2¼2 Hz), 7.57e7.59 (m, 8H), 7.71 (d,
2H, J¼7.5 Hz), 7.78 (d, 4H, J¼8.5 Hz), 8.14 (d, 4H,
J¼1.5 Hz) ppm; 13C NMR d CDCl3: 14.30, 22.85, 24.05,
29.26, 30.28, 32.08, 32.26, 35.02, 40.65, 55.58, 89.50,
91.44, 109.48, 116.56, 120.33, 122.01, 122.12, 123.87,
123.99, 126.32, 126.70, 131.10, 133.25, 138.38, 139.19,
141.10, 143.48, 151.48 ppm; MS (MALDI-TOF) (m/z):
1117.7 (Mþ). Anal. Calcd for C83H92N2: C, 89.20; H, 8.30;
N, 2.51. Found: C, 89.19; H, 8.41; N, 2.50.
C193H231N: C, 90.38; H, 9.08; N, 0.55. Found: C, 90.35; H,
9.08; N, 0.65.
4.7.2. 9,90-(4,40-(7,70-(9,9-Diheptyl-9H-fluorene-2,7-
diyl)bis(ethyne-2,1-diyl)bis(9,9-diheptyl-9H-fluorene-7,2-
diyl))bis(ethyne-2,1-diyl)bis(4,1-phenylene))bis(3,6-di-tert-
butyl-9H-carbazole) (Cz2F3)
Yield 78%. 1H NMR d CDCl3: 0.65 (br, 12H), 0.82 (t, 18H,
J¼7.5 Hz), 1.08 (br, 36H), 1.18e1.21 (m, 12H), 1.47 (s, 36H),
2.02 (br, 12H), 7.40 (d, 4H, J¼9.0 Hz), 7.48 (dd, 4H,
J1¼8.5 Hz, J2¼2.0 Hz), 7.57e7.59 (m, 16H), 7.69e7.71 (m,
6H), 7.77 (d, 4H, J¼8.0 Hz), 8.15 (d, 4H, J¼1.0 Hz) ppm;
4.7.5. 9,90-(4,40-(7,70-(7,70-(9-p-Tolyl-9H-carbazole-3,6-
diyl)bis(ethyne-2,1-diyl)bis(9,9-diheptyl-9H-fluorene-7,2-
diyl)bis(ethyne-2,1-diyl))bis(9,9-diheptyl-9H-fluorene-7,2-
diyl)bis(ethyne-2,1-diyl))bis(4,1-phenylene))bis(3,6-di-tert-
butyl-9H-carbazole) (Cz3F4)
Yield 65%. 1H NMR d CDCl3: 0.65 (br, 16H), 0.82 (t, 24H,
J¼7.5 Hz), 1.08 (br, 48H), 1.18e1.22 (m, 16H), 1.47 (s, 36H),
2.02e2.04 (m, 16H), 2.52 (s, 3H), 7.36e7.41 (m, 6H), 7.45e

Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
2667
7.50 (m, 8H), 7.56e7.60 (m, 20H), 7.65 (dd, 2H, J1¼8.5 Hz,
J2¼2.0 Hz), 7.71 (d, 8H, J¼7.5 Hz), 7.78 (d, 4H, J¼8.5 Hz),
8.14 (d, 4H, J¼1.5 Hz), 8.38 (s, 2H) ppm; 13C NMR
d CDCl3: 14.30, 21.54, 22.85, 24.03, 29.28, 29.30, 30.29,
30.32, 32.10, 32.25, 35.01, 40.70, 40.77, 55.54, 55.55,
89.39, 89.45, 90.98, 91.14, 91.46, 109.46, 110.45, 115.20,
116.55, 120.22, 120.25, 120.28, 120.31, 121.99, 122.11,
122.37, 122.69, 123.19, 123.84, 123.98, 124.29, 126.11,
126.19, 126.22, 126.26, 126.67, 127.17, 130.23, 130.92,
131.02, 131.08, 133.23, 134.42, 138.32, 138.39, 139.15,
140.66, 140.89, 141.11, 141.16, 141.36, 143.45, 151.38,
151.42 ppm; MS (MALDI-TPF) (m/z): 2549.4 (Mþ). Anal.
Calcd for C191H213N3: C, 89.94; H, 8.42; N, 1.65. Found: C,
89.98; H, 8.39; N, 1.45.
(MALDI-TOF) (m/z): 3683.2 (Mþ). Anal. Calcd for
276H310N4: C, 90.00; H, 8.48; N, 1.52. Found: C, 89.97; H,
8.50; N, 1.72.
C
4.8. Fabrication and characterization of OLEDs
All the devices were fabricated on bare ITO substrates that
were cleaned by detergent, deionized water, acetone, and
ethanol. Poly(3,4-ethylenedioxythiophene):poly(4-styrenesul-
fonate) (PEDOT:PSS) was spin-coated on ITO glass, and
was baked under 100 ꢀC for 2 h. Compounds Cz2F, Cz2F3,
Cz2F5, CzF6, Cz3F4, CzF9, and Cz4F6 were spin-coated
onto PEDOTePSS layer from their toluene solutions. Films
of 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) and
Al cathodes were formed by vacuum deposition under a pres-
sure of 3ꢃ10ꢁ4 Pa. The deposition rate for TPBI and Al
4.7.6. 3,6-Bis((7-((7-((9,9-diheptyl-9H-fluoren-2-
yl)ethynyl)-9,9-diheptyl-9H-fluoren-2-yl)ethynyl)-9,9-
diheptyl-9H-fluoren-2-yl)ethynyl)-9-(4-((7-((7-((9,9-
diheptyl-9H-fluoren-2-yl)ethynyl)-9,9-diheptyl-9H-fluoren-
2-yl)ethynyl)-9,9-diheptyl-9H-fluoren-2-yl)ethynyl)phenyl)-
9H-carbazole (CzF9)
cathode layers was 1 and 5 A sꢁ1, respectively. The thickness
˚
of the thin films was monitored by a quartz crystal oscillator
placed near the substrates and was calibrated ex situ by an
Ambios Technology XP-2 surface profilometer. EL spectra
were recorded with a Photo Research PR-650 spectrophotom-
eter. Currentevoltage characteristics were measured with
a Hewlett-Packard 4140B semiconductor parameter analyzer.
A Newport 2835-C multifunction optical meter was used to
measure the luminescence output.
1
Yield 58%. H NMR d CDCl3: 0.65 (br, 36H), 0.80e0.85
(m, 54H), 1.07e1.10 (m, 108H), 1.17e1.22 (m, 36H),
1.98e2.04 (m, 36H), 7.33e7.37 (m, 10H), 7.47 (d, 2H,
J¼8.0 Hz), 7.57e7.63 (m, 30H), 7.69e7.74 (m, 21H), 7.86
(d, 2H, J¼8.5 Hz), 8.42 (s, 2H) ppm; 13C NMR d CDCl3:
14.27, 22.80, 22.84, 23.97, 29.22, 29.28, 30.26, 30.27,
32.04, 32.08, 40.67, 40.75, 55.37, 55.50, 90.60, 90.91,
90.98, 91.01, 91.06, 91.15, 110.38, 115.69, 119.90, 120.22,
121.62, 122.12, 122.18, 122.31, 122.52, 123.10, 126.10,
126.14, 126.19, 127.10, 127.75, 130.80, 130.90, 130.96,
133.45, 140.65, 140.72, 140.80, 140.85, 140.96, 141.01,
141.67, 151.00, 151.23, 151.34 ppm; MS (MALDI-TOF) (m/z):
3704.5 (Mþ). Anal. Calcd for C279H337N: C, 90.45; H, 9.17;
N, 0.38. Found: C, 90.44; H, 9.13; N, 0.42.
Acknowledgements
P.L. thanks the National Natural Science Foundation of
China (20674070) and the Natural Science Foundation of Zhe-
jiang Province (R404109). This work is partially supported by
the Major State Basic Research Development Program and the
Chinese Academy of Sciences.
Supplementary data
4.7.7. 9,90-(4,40-(7,70-(7,70-(9-(4-((7-((7-((4-(3,6-Di-tert-
butyl-9H-carbazol-9-yl)phenyl)ethynyl)-9,9-diheptyl-9H-
fluoren-2-yl)ethynyl)-9,9-diheptyl-9H-fluoren-2-
yl)ethynyl)phenyl)-9H-carbazole-3,6-diyl)bis(ethyne-2,1-
diyl)bis(9,9-diheptyl-9H-fluorene-7,2-diyl)bis(ethyne-2,1-
diyl))bis(9,9-diheptyl-9H-fluorene-7,2-diyl)bis(ethyne-2,1-
diyl))bis(4,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole)
(Cz4F6)
Supplementary data and representative spectra associated
with this article can be found in the online version, at
doi:10.1016/j.tet.2007.12.059.
References and notes
1. Tang, C. W.; Van Slyke, S. A. Appl. Phys. Lett. 1987, 51, 913.
2. Montes, V. A.; Li, G.; Pohl, R.; Shinar, J.; Anzenbacher, P., Jr. Adv. Mater.
2004, 16, 2001.
1
Yield 50%. H NMR d CDCl3: 0.65 (br, 24H), 0.81e0.84
(m, 36H), 1.09 (m, 72H), 1.18e1.21 (m, 24H), 2.04 (br,
24H), 7.41 (d, 6H, J¼8.5 Hz), 7.45 (d, 2H, J¼8.5 Hz), 7.49
(dd, 6H, J1¼8.5 Hz, J2¼1.5 Hz), 7.56e7.61 (m, 34H), 7.68e
7.72 (m, 12H), 7.78 (d, 6H, J¼8.0 Hz), 7.85 (d, 2H,
J¼8.5 Hz), 8.15 (s, 6H), 8.40 (s, 2H) ppm; 13C NMR
d CDCl3: 14.31, 22.84, 24.01, 29.27, 30.28, 30.30, 32.08,
32.23, 34.98, 40.69, 46.42, 55.52, 89.43, 90.91, 90.99,
91.12, 91.41, 109.44, 115.69, 116.54, 120.27, 120.30,
121.92, 121.96, 122.10, 122.30, 122.54, 123.47, 123.79,
123.97, 126.09, 126.19, 126.22, 126.62, 130.90, 130.99,
131.05, 133.20, 138.28, 139.09, 140.72, 140.81, 140.87,
140.91, 141.04, 141.12, 141.33, 143.42, 151.37 ppm; MS
3. Tseng, R. J.; Chiechi, R. C.; Wudl, F.; Yang, Y. Appl. Phys. Lett. 2006, 88,
093512.
4. Hung, L. S.; Chen, C. H. Mater. Sci. Eng., R. 2002, 39, 143.
5. Mitschke, U.; Bauerle, P. J. Mater. Chem. 2000, 10, 1471.
6. Shirota, Y. J. Mater. Chem. 2000, 10, 1.
7. Wolak, M. A.; Delcamp, J.; Landis, C. A.; Lane, P. A.; Anthony, J.; Kafafi,
Z. Adv. Funct. Mater. 2006, 16, 1943.
8. Baldo, M. A.; O’Brien, D. F.; You, Y.; Shoustikov, A.; Sibley, S.; Thomp-
son, M. E.; Forrest, S. R. Nature 1998, 395, 151.
9. Kawamura, Y.; Goushi, K.; Brooks, J.; Brown, J. J.; Sasabe, H.; Adachi,
C. Appl. Phys. Lett. 2005, 86, 071104.
10. Friend, R. H.; Gymer, R. W.; Holmes, A. B.; Burroughes, J. H.; Marks,
R. N.; Taliani, C.; Bradley, D. D. C.; Dos Santos, D. A.; Bredas, J. L.;
Logdlund, M.; Salaneck, W. R. Nature 1999, 397, 121.

2668
Z. Zhao et al. / Tetrahedron 64 (2008) 2658e2668
11. Chen, C.-T. Chem. Mater. 2004, 16, 4389.
12. Kim, Y.-H.; Shin, D.-C.; Kim, S.-H.; Ko, C.-H.; Yu, H.-S.; Chae, Y.-S.;
Kwon, S.-K. Adv. Mater. 2001, 13, 1690.
28. Zhu, W.; Hu, M.; Yao, R.; Tian, H. J. Photochem. Photobiol., A: Chem.
2003, 154, 169.
29. Lu, J.; Tao, Y.; D’iorio, M.; Li, Y.; Ding, J.; Day, M. Macromolecules
2004, 37, 2442.
13. Shi, J.; Tang, C. W. Appl. Phys. Lett. 2002, 80, 3201.
14. Culligan, S. W.; Chen, A. C.-A.; Wallace, J. U.; Klubek, K. P.; Tang,
C. W.; Chen, S. H. Adv. Funct. Mater. 2006, 16, 1481.
15. Kim, Y.-H.; Jeong, H.-C.; Kim, S.-H.; Yang, K.; Kwon, S.-K. Adv. Funct.
Mater. 2005, 15, 1799.
30. Xing, Y.; Xu, X.; Zhang, P.; Tian, W.; Yu, G.; Lu, P.; Liu, Y.; Dao, D.
Chem. Phys. Lett. 2006, 423, 293.
31. Liu, L.; Wong, W.-Y.; Shi, J.-X.; Cheah, K.-W. J. Polym. Sci., Part A:
Polym. Chem. 2006, 44, 5588.
16. Kulkarni, A. P.; Gifford, A. P.; Tonzola, C. J.; Jenekhe, S. A. Appl. Phys.
Lett. 2005, 86, 061106.
32. Zhang, Q.; Chen, J.; Cheng, Y.; Wang, L.; Ma, D.; Jing, X.; Wang, F.
J. Mater. Chem. 2004, 14, 895.
33. Lee, S. H.; Nakamura, T.; Tsutsui, T. Org. Lett. 2001, 3, 2005.
17. Chan, L. H.; Lee, R. H.; Hsieh, C. F.; Yeh, H. C.; Chen, C. T. J. Am. Chem.
Soc. 2002, 124, 6469.
34. Brunner, K.; Dijken, A.; Borner, H.; Bastiaansen, J. J. A. M.; Kiggen,
¨
18. Kim, J. U.; Lee, H. B.; Shin, J. S.; Kim, Y. H.; Joe, Y. K.; Oh, H. Y.; Park,
C. G.; Kwon, S. K. Synth. Met. 2005, 148, 205.
K. M. M.; Langeveld, B. M. W. J. Am. Chem. Soc. 2004, 126, 6035.
35. Chen, B.; Wu, Y.; Wang, M.; Wang, S.; Sheng, S.; Zhu, W.; Sun, R.; Tian,
H. Eur. Polym. J. 2004, 40, 1183.
19. Wu, C. C.; Lin, Y. T.; Wong, K. T.; Chen, R. T.; Chien, Y. Y. Adv. Mater.
2004, 16, 61.
20. Chao, T. C.; Lin, Y. T.; Yang, C. Y.; Hung, T. S.; Chou, H. C.; Wu, C. C.;
Wong, K. T. Adv. Mater. 2005, 17, 992.
36. Ding, J.; Day, M.; Robertson, G.; Roovers, J. Macromolecules 2002, 35, 3474.
37. Melhuish, W. H. J. Phys. Chem. 1961, 65, 229.
38. Meech, S. R.; Phillips, D. J. Photochem. 1983, 23, 193.
39. Hamal, S.; Hirayama, F. J. Phys. Chem. 1983, 87, 83.
40. Yamaguchi, Y.; Ochi, T.; Miyamura, S.; Tanaka, T.; Kobayashi, S.;
Wakamiya, T.; Matsubara, Y.; Yoshida, Z.-i. J. Am. Chem. Soc. 2006,
128, 4504.
21. Klaerner, G.; Miller, R. D. Macromolecules 1998, 31, 2007.
22. Wu, F.-I.; Reddy, D. S.; Shu, C.-F.; Liu, M. S.; Jen, A. K.-Y. Chem. Mater.
2003, 15, 269.
23. Rathnayake, H. P.; Cirpan, A.; Delen, Z.; Lahti, P. M.; Karasz, F. E. Adv.
Funct. Mater. 2007, 17, 115.
24. Li, Z. H.; Wong, M. S. Org. Lett. 2006, 8, 1499.
25. Wong, K.-T.; Chien, Y.-Y.; Chen, R.-T.; Wang, C.-F.; Lin, Y.-T.; Chiang,
H.-H.; Hsieh, P.-Y.; Wu, C.-C.; Chou, C. H.; Su, Y. O.; Lee, G.-H.; Peng,
S.-M. J. Am. Chem. Soc. 2002, 124, 11576.
26. Xia, C.; Advincula, R. C. Macromolecules 2001, 34, 5854.
27. Li, Y.; Ding, J.; Day, M.; Tao, Y.; Lu, J.; D’iorio, M. Chem. Mater. 2004,
16, 2165.
41. Shih, P.-I.; Tseng, Y.-H.; Wu, F.-I.; Dixit, A. K.; Shu, C.-F. Adv. Funct.
Mater. 2006, 16, 1582.
42. Tao, S.; Peng, Z.; Zhang, X.; Wang, P.; Lee, C.-S.; Lee, S.-T. Adv. Funct.
Mater. 2005, 15, 1716.
43. Bradley, D. D. C.; Grell, M.; Long, X.; Mellor, H.; Grice, A. Proc. SPIE
1997, 3145, 254.
44. Weinfurtner, K.-H.; Fujikawa, H.; Tokito, S.; Taga, Y. Appl. Phys. Lett.
2000, 76, 2502.