Synthesis, fine structure of 19F NMR and fluorescence of novel amorphous TPA derivatives having perfluorinated cyclopentenyl and benzo[b]thiophene unit

Article abstract of DOI:10.1016/j.saa.2013.01.019

Three novel triphenylamine (TPA) derivatives having perfluorinated cyclopentenyl and benzo[b]thiophene unit are obtained from 4-bromo-N,N-diphenyl- 2-methylbenzo[b]thiophen-5-amine. The new compounds are expected to find their use in thin film devices as charge transport materials and host organic light-emitting materials. It is found that the new compounds show relatively strong fluorescence either in solution or in solid state, and are amorphous due to a special conformation which is elucidated by the fine structure of ¹⁹F NMR. Molecular structure and properties of these compounds is characterized by ¹H NMR, ¹³C NMR (broadband decoupled), ESI-HRMS, elemental analysis and thermal analysis (DSC). Fluorescent quantum yield in solution is measured using 9,10-diphenylanthrancene (DPA) as standard fluorescent substance.

Full text of DOI:10.1016/j.saa.2013.01.019

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
Contents lists available at SciVerse ScienceDirect
Spectrochimica Acta Part A: Molecular and
Biomolecular Spectroscopy
journal homepage: www.elsevier.com/locate/saa
Synthesis, fine structure of 19F NMR and fluorescence of novel amorphous TPA
derivatives having perfluorinated cyclopentenyl and benzo[b]thiophene unit
b
a
b
Bian-Peng Wu a, , Mei-Li Pang , Ting-Feng Tan , Ji-ben Meng
⇑
a School of Science, Tianjin Institute of Urban Construction, No. 26, Jinjing Road, Tianjin 300384, China
b Department of Chemistry, Nankai Univesity, No. 94, Weijin Road, Tianjin 300070, China
g r a p h i c a l a b s t r a c t
h i g h l i g h t s
"
Three novel amorphous
triphenylamine (TPA) derivatives
were obtained from an ‘‘abnormally’’
intermediate.
"
"
"
"
19F NMR of perfluorinated
cyclopentenyl compounds.
Fluorescence of the compounds in
solution and solid-state.
Fluorescent quantum yield in
solution was measured.
Amorphism of the solid powder was
measured by DSC.
a r t i c l e i n f o
a b s t r a c t
Article history:
Three novel triphenylamine (TPA) derivatives having perfluorinated cyclopentenyl and benzo[b]thio-
phene unit are obtained from 4-bromo-N,N-diphenyl-2-methylbenzo[b]thiophen-5-amine. The new
compounds are expected to find their use in thin film devices as charge transport materials and host
organic light-emitting materials. It is found that the new compounds show relatively strong fluorescence
either in solution or in solid state, and are amorphous due to a special conformation which is elucidated
by the fine structure of 19F NMR. Molecular structure and properties of these compounds is characterized
by 1H NMR, 13C NMR (broadband decoupled), ESI–HRMS, elemental analysis and thermal analysis (DSC).
Fluorescent quantum yield in solution is measured using 9,10-diphenylanthrancene (DPA) as standard
fluorescent substance.
Received 4 November 2012
Received in revised form 25 December 2012
Accepted 10 January 2013
Available online 23 January 2013
Keywords:
Benzothiophene
Triarylamine (TPA)
Fluorinated cyclopentene
Amorphous state
Fluorescent materials
Ó 2013 Elsevier B.V. All rights reserved.
Introduction
[2–4]. Molecules derived from TPA have also been widely
investigated as hole-transporting materials (HTMs) of small mole-
Triphenylamine (TPA) is an outstanding windmill-like molecule
with useful functions [1]. TPA, as building blocks, is widely used in
the synthesis of materials with various applications, such as
electro-photographic photoreceptors, TiO2 electrode sensitizers
for solar cells, polymers for emitting materials, dendrimers,
octupoles for second harmonic generation (SHG), as well as octu-
polar, multibranched and dendric chromophores for two-photo
absorption
cules [5]. Many of the compounds became a kind of important and
basic materials in the fields of organic light-emitting diodes
(OLEDs) [6–10] and dye-sensitized solar cells (DSCs) [11–13].
Because TPA-based small molecules crystallized easily, the service
life of OLED is very limited [14]. In order to improve device perfor-
mance, multiple TPA structural units, multiple
p-bond and the
groups with electronic and spatial effects are introduced in one
molecule to control the charge transfer efficiency and improve
the film-forming to inhibit the self-crystallization [15]. For
example, star structure give s improved amorphous film-forming
and thermodynamic stability [16]. Particular interest is devoted
⇑
Corresponding author. Tel.: +86 22 23085110; fax: +86 22 23509933.
E-mail address: bianpeng-wu@163.com (B.-P. Wu).
1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.saa.2013.01.019

40
B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
Scheme 1. Synthesis of novel amorphous TPA derivatives having perfluorinated cyclopentenyl and benzo[b]thiophene unit.
Fig. 1. NMR characterization of related compounds. Top left: 1H comparison of between the compounds; top right: 13C NMR of compound 2; bottom left: 13C NMR of compound
3; bottom right: 19F NMR of compound 4 and compound 5 (5a and 5b).

B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
41
Fig. 2. Optimized conformations of 4, 5a and 5b. (a) compound 4; (b) compound 5a; (c) compound 5b.
Fig. 3. Fluorescence spectrum. Top left: emitting spectrum and excitation spectrum of compound 2, the inset figure: the picture of fluorescence of compound 2, excited by
light of ꢀ375 nm; top right: the comparison of emitting spectrum in solution and solid state, kex = 365 nm; bottom left: 3D fluorescence spectrum of 2 in chloroform; bottom
right: 3D fluorescence spectrum of 5a in solid state.
to multiple aryl derivatives [17–19], which combined with TPA
may give promising results, such as dendrimers, star-like
compounds up to polymers [3–5,16,20–23]. But the final yields
these kinds of compounds were fairly low due to multiple steps
of Ar- and Ar-coupling reactions.
In addition, molecules having both charge transfer and fluores-
cence were a kind of host organic light-emitting materials. As is
well known, 8-hydroxyquinoline aluminum is a typical host mole-
cule [24]. When used in the electroluminescent device, host light-
emitting materials showed high luminous efficiency on relatively
simple layer structure. But, for those TPA-based compounds,
crystalline-interfering structure is detrimental to fluorescence
generally [25].
the things we wish for. In this paper, three novel TPA-based
compounds are obtained from 4-bromo-N,N-diphenyl-2-meth-
ylbenzo[b]thiophen-5-amine, an intermediate we previously ob-
tained due to ‘‘abnormal’’ reaction selectivity [26]. When
perfluorinated cyclopentenyl is bonded to the 4-position of
2-methyl-5-diarylamino-benzo[b]thiophene, the resulting com-
pounds are amorphous and meanwhile strongly fluorescent.
Results and discussion
Synthesis and characterization
If some kind of simple TPA-based molecules themselves could
also have the fairly good performance in application, it will be
The synthesis of target compounds 4 and 5 was accomplished as
in Scheme 1. The intermediate, 1c was obtained through four steps

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B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
Fig. 4. Comparison of fluorescence intensity and measurement of fluorescence quantum yield. Top left: the picture of fluorescence intensity in different state, (a-1) 5a in ethyl
acetate; (a-2) 5a in chloroform; (a-3) 5a in petroleum; (a-4) 5a in ethanol; (a-5) 5a solid; (a-6) 5a film on frosted glass; (b-1) 4 in ethyl acetate; (b-2) 4 in chloroform; (b-3) 4
in petroleum; (b-4) 4 in ethanol; (b-5) 4 solid; (b-6) the film of 4 on the surface of frosted glass; top right: excitation spectrum of 4, 5a an 5b solid; 5a in petroleum; DPA in
cyclohexane, 365 nm was selected as excitation wavelength for the measurement of quantum yield; bottom left: the fluorescent spectrums and quantum yield of compound 4
in different solvent, excited by light of 365 nm; bottom right: the fluorescent spectrums and quantum yield of compound 5a in different solvent, excited by light of 365 nm.
as shown above. Firstly, acetyl thiophenol reacted with 2,3-
dichloropropene. The resulting compound 1a was converted to
1c through Claisen rearrangement/elimination reaction and hydro-
lysis [27]. A novel TPA derivative 2, as crystalline powder, was con-
structed from 1c by Ullmann reaction [28,29]. Structural
compositions of the compounds were established by spectral (1H,
13C NMR and high-resolution mass) methods and elemental analy-
sis. As is shown in Fig. 1b, compound 2 gave 13 peaks in 13C NMR
(broadband decoupled) due to the symmetry of its structure in
which the two benzene rings (ring A and ring B) were in similar
magnetic environment. In the 1H NMR of 2, the peaks were very
consistent with the H’s on aromatic rings. More importantly, weak
but clear coupling effect existing between 3-H and 2-CH3 could be
found. The H’s at 2-CH3 split off two peaks. The coupling constant
(4JH–H) was relatively small (about 1 Hz). This was the evidence of
the existence of 3-H.
The key intermediate 3 was unexpectedly obtained as sticky solid
(without solidifying) when 2 was brominated. ‘‘Abnormal’’ reaction
selectivity led to the formation of 3. This may be confirmed by the
splitting of 2-CH3 (Fig. 1a). An analogue of 3, 4-bromo-N,
N-bis(4-tert-butylphenyl)-2-methylbenzo[b]thiophen-5-amine had
been synthesized. The presence of the 4-Br could be directly con-
firmed by the single crystal test of the analogue (see Supplemental
information). In addition, the difference of ring A and ring B of 3
wasincreaseddue to the presenceof4-Brsothat13C NMR (broadband
decoupled) of 3 gave 21 peaks.
Compounds 4 and 5 were synthesized from the lithium com-
pound of 3 by adjusting the proper level of octafluorocyclopentene.
1H NMR spectrums of 4 and 5 are almost the same (Fig. 1a) so that
they could not be distinguished by using 1H NMR. However, 19F
NMR of them had given some important structural information
due to the wide range of d and higher resolution of 19F NMR. As
shown in Fig. 1d, 4 and 5 gave different 19F NMR spectrums.
Mono-substituted 4 had four groups of peaks, while di-substituted
5 had two groups of peaks. In addition, the fine structure had re-
vealed important information about the distribution of the atoms
in space. For compound 4, every F atoms on cyclopentene had sig-
nificantly different magnetic environment, which resulted more
than six peaks. For the reason of confirmation (Fig. 2a), the two
fluorine atoms on the same carbon atom had different d because
they were on the different side of five-membered ring. For com-
pound 5, it had two isomers (5a and 5b) with different polarity.
The isomers had the same mass spectral characteristics, the same
elemental composition, similar 1H NMR spectrums and 19F NMR
spectrums. However, the fine structure of peaks had significant dif-
ference. They were most likely conformational isomers.
The results of structure optimization by Chem3D/MM2 indicate
that compounds, 4, 5a and 5b, were all in the non-planar

B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
43
Table 1
second harmonic. The measurement results showed that, with
the increase of solvent polarity, the fluorescence quantum yield
decreased. The maximum fluorescence emission wavelength short-
ened with the decrease of solvent polarity (Table 1). For example,
5a in petroleum achieved the 84.2% excited by light of 365 nm
and gave the maximum emission wavelength at 505 nm (Fig. 4d).
Solvent effects on quantum yield might be the reasonable explana-
tion. Because stronger interaction existed among polar solvent
molecules and TPA derivatives such as dipole interaction, hydrogen
bond, more energy loss occurred through solvate. Quantum yield of
compound 5 was higher than of compound 4, and 5a higher than
5b (Fig. 4c and d).
Fluorescence quantum yield (%).
Compounds
Fluorescence quantum yield (%)ꢁ (kex = 365 nm)
Ethanol
Ethyl acetate
Chloroform
Petroleum
4
5a
17.7
20.0
24.5
43.3
36.5
47.4
81.4
84.2
Thermal properties of any materials are important for practical
application. The phase transition characteristics of the compounds
in solid state were characterized using Differential Scanning Calo-
rimetry (DSC) (Fig. 5). Except that, on first heating and cooling run,
clear but fairly weak phase transition of 5b occurred at about
82.1 °C on heating, any phase transition could not be observed
for the compounds on heating or cooling. Only some glass transi-
tion process could be seen (for 5a, Tg = 43.6 °C on heating,
Tg = 54.2 °C on cooling). It could be confirmed that these com-
pounds are amorphous due to a special fixed conformation which
hindered the molecules to crystallize.
Conclusions
Three novel triarylamine (TPA) derivatives were synthesized
from an unexpectedly obtained intermediate 3 via normal syn-
thetic routes. The structure of related compounds was confirmed
by 1H NMR, 13C NMR (broadband decoupled), 19F NMR, ESI–HRMS
and elemental analysis. The fluorescent measurements and ther-
mal analysis have revealed that 4-perfluorinated cyclopentenyl
gave the molecules relatively strong fluorescence and made the
molecules become amorphous materials, which is very beneficial
for improving the life of film device. The novel compounds were
expected to find their use as host emitting materials and charge
transport materials.
Fig. 5. Differential Scanning Calorimetry (DSC) of 4, 5a and 5b on first heating/
cooling run, heating from 0 to 230 °C, 10 °C/min., then cooling from 230 °C to
ꢂ20 °C, 10 °C/min.
conformation (Fig. 2). 5a and 5b could not transform into each
other due to the large rotation hinder. 5a had smaller polarity than
5b so that it was first eluted from column. It could be find in 19F
NMR that in the two groups of 5a, the four Fb atoms had similar
environment and split into three peaks by Fa (Fig. 1d, spectrum
5-a), and 5b had three groups of peaks (Fig. 1d, spectrum 5-b).
Experimental
Fluorescence and differential thermal analysis
General
Compound 2 was a kind of puzzling fluorescent substance with
a narrow band (370–450 nm) in the excitation spectrum (Fig. 3, top
left and bottom left). The yellow1 line (Fig. 3, bottom left) at
370 nm was the line of demarcation. For this reason, its fluores-
cence could not be observed under ordinary dual-wavelength
(254 nm and 365 nm) UV lamp. As seen in Fig. 3, top left (the inset
figure), compound 2 could emit obvious fluorescence under LED
UV light source (375–400 nm). In addition, weak up-conversion
fluorescence could also be observed for compound 2. Compounds
4 and 5 showed very strong fluorescence either in solution or solid
state (Figs. 3 and 4, top left). It was found that they emitted signif-
icant yellow fluorescence excited by the light in range of 200–
500 nm when in solid state (Fig. 3, bottom left). The maximum
emission wavelength in the solid state was longer than in solution
(Fig. 3, top right).
The starting compounds, 4-Aminothiophenol (content of 98.5%)
and 2,3-dichloropropene (content of 97.5%) and all other reagents
were used as commercially available reagents without being puri-
fied except for N-bromosuccinimide (NBS), Cu powder and 9,10-
diphenylanthrancene (DPA). NBS was recrystallized in 1,2-dichlo-
roethane to remove bromine. Cu powder was activated by being
treated with 1:1 (v:v) HCl, filtered and washed with ethanol and
acetone. After drying in air, the fresh powder was stored in a nitro-
gen atmosphere. DPA was purified by recrystallization in toluene.
1H NMR and 13C NMR spectra were recorded using Bruker
AV300 (300 MHz) and Bruker AV400 (400 MHz) spectrometer with
chemical shifts (in ppm) relative to tetramethylsilane (TMS). ESI–
HRMS were recorded on a Finnigan MAT95 mass spectrometer.
The phase transition were investigated by a TA DSC Q20 differen-
tial scanning calorimeter at a heating and cooling rate of 10 °C/
min. Fluorescence spectrum were measured on Hitachi F-7000.
UV–visible absorbance was measured on PerkinElmer Lambda 35.
In order to measure the fluorescence quantum efficiency of
compounds 4, 5a and 5b in solution, 9,10-diphenylanthrancene
(DPA) in cyclohexane was selected as standard quantum yield be-
cause it had similar fluorescence spectrum. As seen in Fig. 4b,
365 nm was the appropriate exciting wavelength, which could at-
tain enough fluorescence intensity and avoid the interference of
Synthesis
N-(4-(2-chloroallylthio) phenyl) acetamide 1a
4-Aminothiophenol (100 g, 0.8 mol), acetic acid (100 mL) were
added in three-necked bottle of 250 mL three-necked round-bottomed
1
For interpretation of color in Fig. 3, the reader is referred to the web version of
this article.

44
B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
flask equipped with mechanical stirrer, thermometer and distilling
Vigreux (200 mm). The mixture was heated to boiling and 48 mL of
water and small amount of acetic acid was collected at 104–106 °C
(the temperature of distillate liquid). After cooling to below 75 °C,
200 mL of ethanol (95%) was added and then heated to solve the result-
ing solid. On cooling to room temperature, 110 g of orange-yellow crys-
talline was obtained through vacuum filtration, yield 82.1%, m.p. 152–
156 °C (lit. 151–153 °C).
(60–90 °C, 70 mL) and Al2O3 microsphere (80–100 mesh, 20 mL
by apparent volume) was added. After stirring for 5 min, yellow
clear solution was obtained by filtration. Petroleum ether was
evaporated off in vacuo to give yellow solid 2 (0.65 g), yield 67%,
m.p. 136–140 °C. 1H NMR (400 MHz, CDCl3): d (ppm) = 7.61 (d,
J = 8.59 Hz, 1H), 7.38 (d, J = 2.05 Hz, 1H), 7.25–7.20 (m, 4H), 7.07
(ddd, J = 10.82, 8.61, 1.57 Hz, 5H), 6.98 (dd, J = 10.48, 4.18 Hz,
2H), 6.82 (s, 1H), 2.56 (d, J = 0.98 Hz, 1H); Elemental analysis
(CHN, %): Calculated for C21H17NS, C 79.96, H 5.43, N, 4.44; Found:
C 79.80, H 5.23, N, 4.54; ESI–HRMS [M]+: m/z calculated for
The above product (50 g, 0.3 mol), anhydrous K2CO3 powder
(40 g) and acetone (70 mL) in three-necked bottle were added
2,3-dichloropropene (29.5 g, 0.27 mol) in acetone (50 mL) drop-
wise and stirred for additional 3 h. The resulting mixture was vac-
uum filtration. The filtrate was concentrated until solid appeared.
After cooling to room temperature, yellow flaky solid 1a (66.8 g)
was collected by filtrating and washing with ethanol (95%), yield
92.3%, m.p. 94–96 °C (98–100 °C after recrystallization in ethanol
C
21H17NS, 315.1082, Found: 316.1150 (M+H+, 100%).
4-Bromo-N,N-diphenyl-2-methylbenzo[b]thiophen-5-amine 3
N-bromosuccinimide (NBS) (3.9 g, 21.7 mmol) was dissolved in
a solution of acetated acid (45.0 mL) and CHCl3 (80.0 mL). 2-
methyl-N,N-diphenylbenzo[b]thiophen-5-amine
2
(5.0 g,
(95%), recovery 66.8%). 1H NMR (400 MHz, CDCl3):
d
15.9 mmol) in a solution of CHCl3 (150 mL) was added drop-wised
to the above solution below ꢂ13 °C in 1 h. The result mixture was
washed with water and neutralized with sodium carbonate to ba-
sicity. After concentration, the crude solid was purified by column
chromatography on silica gel with petroleum ether (60–90 °C) to
give colorless sticky compound 3 (6.1 g, yield 97.3%). 1H NMR
(300 MHz, CDCl3): d (ppm) = 7.61 (dd, J = 8.55, 3.07 Hz, 1H), 7.31
(ddd, J = 10.04, 6.14, 2.69 Hz, 3H), 7.26–7.18 (m, 3H), 7.08–6.95
(m, 4H), 6.94–6.89 (m, 2H), 6.80 (s, 1H); Elemental analysis
(CHN, %): Calculated for C21H16BrNS, C 63.96, H 4.09, N, 3.55;
Found: C 63.81, H 4.04, N, 3.50; ESI–HRMS [M]+: m/z calculated
for C21H16BrNS, 393.0187, Found: 394.0267 (M+H+, 100%).
(ppm) = 7.35–7.48 (m, ArAH, 4H), 5.20 (AClC@CH2, 2H), 3.65
(SACH2A, 2H), 2.17 (s, ACH3, 3H); Elemental analysis (CHN, %): cal-
culated for C11H12ClNOS, C 54.65, H 5.00, N 5.79, Found: C 54.55, H
4.95, N 5.80; ESI–HRMS [M]+: m/z calculated for C11H12ClNOS+,
241.0328, Found: 242.0407 (M+H+, 100%).
N-(2-methylbenzo[b]thiophen-5-yl) acetamide 1b
Compound 1a (35.5 g, 98.0 mmol) and N,N-diethylaniline
(150 mL) reacted at 208–215 °C for 20 h in N2 atomsphere. Ethyl
acetate (100 mL) was added after cooling to room temperature.
The mixture was extracted three times with hydrochloric acid
(15%, 200 mL). The organic phase was washed with water and
dried under anhydrous MgSO4. Ethyl acetate was distillated off un-
der vacuum. Solid product (21.2 g) was filtrated off and recrystal-
lized in ethanol and water (3:4). Pearl flake solid 1b (15.3 g) was
obtained, yield 72%, m.p. 138–141 °C. 1H NMR (300 MHz, CDCl3):
d (ppm) = 7.96 (d, J = 1.77 Hz, 1H), 7.63 (d, J = 8.56 Hz, 1H), 7.37
(s, 1H), 7.21 (dd, J = 8.56, 1.92 Hz, 1H), 6.90 (s, 1H), 2.56 (d,
J = 1.01 Hz, 3H), 2.19 (s, 3H); Elemental analysis (CHN, %): Calcu-
lated for C11H11NOS, C 64.36, H 5.40, N 6.82, Found (%): C 64.20,
H 5.29, N 6.68; ESI–HRMS[M]+: m/z calculated for C11H11NOS,
205.0561, Found: 206.0641 (M+H+, 100%).
Compound 4
Compound 3 (0.278 g, 0.70 mmol) in THF (15 mL) was cooled to
below ꢂ78 °C under N2 atomsphere, and n-Butyllithium (0.31 mL)
was added dropwise. The reaction mixture was kept at below
ꢂ78 °C for 1 h. C5F8 (0.38 ml, 2.83 mmol) was injected to react
for 1 h. Ethanol (0.5 mL) was added to terminate the reaction. Sol-
vent was evaporated in vacuo. Purification by column chromatog-
raphy (petroleum ether, 60–90 °C) on silica gel gave 4 as yellow
solid (204.3 mg, 57.6%). 1H NMR (400 MHz, CDCl3: d (ppm) = 7.65
(d, J = 8.60 Hz, 1H), 7.41 (s, 1H), 7.28 (d, J = 7.44 Hz, 2H), 7.21 (d,
J = 8.17 Hz, 2H), 7.14 (d, J = 7.66 Hz, 2H), 7.09 (d, J = 7.34 Hz, 1H),
7.05 (d, J = 8.28 Hz, 1H), 6.92 (d, J = 7.97 Hz, 2H), 6.84 (s, 1H),
2.57 (s, 3H). Elemental analysis (CHN, %): Calculated for C26H16F7-
NS, C 61.54, H 3.18, N 2.76, Found: C 61.35, H 3.16, N 2.74; ESI–
HRMS [M]+: m/z calculated for C26H16F7NS, 507.0892, Found:
508.0960 (M+H+, 100%).
2-Methylbenzo[b]thiophen-5-amine 1c
Compound 1b (7.2 g, 35.1 mmol) and NaOH aqueous solution
(10%, 100 mL) were stirred overnight under reflux and N2 atom-
sphere. After cooling, the oil product in the bottom of flask solidi-
fied. The solid (5.2 g) was collected by filtration, yield 91%, m.p.
48–52 °C. The crude product was purified by recrystalization in
ethanol (95%) and water (1:1.64). white pearl solid product 1c
Compound 5a and compound 5b
was obtained, m.p. 56–58 °C. 1H NMR (300 MHz, CDCl3):
d
Compound 3 (0.284 g, 0.72 mmol) in THF (15 mL) was cooled to
below ꢂ78 °C under N2 atomsphere, and n-Butyllithium (0.35 mL)
was added dropwise. The reaction mixture was kept at below
ꢂ78 °C for 1 h. C5F8 (0.048 ml, 0.36 mmol) was injected to react
for 1 h. Ethanol (0.5 mL) was added to stop the reaction. Solvent
was evaporated in vacuo. First fluorescent component 5a
(142.8 mg, 24.7%) as orange solid was separated on column chro-
matography (petroleum ether:chloroform = 6:1 (v:v)) on silica
gel, and second fluorescent component 5b (13.8 mg, 2.4%) as or-
ange solid with petroleum ether:chloroform = 2:1 (v:v). For 5a,
1H NMR (400 MHz, CDCl3): d (ppm) = 7.64 (d, J = 8.55 Hz, 2H),
7.41 (d, J = 1.98 Hz, 2H), 7.25 (dd, J = 26.32, 8.51 Hz, 8H), 7.14 (d,
J = 7.48 Hz, 4H), 7.08 (d, J = 7.32 Hz, 2H), 7.05 (dd, J = 8.55,
2.12 Hz, 2H), 6.92 (d, J = 8.85 Hz, 4H), 6.84 (s, 2H), 2.57 (d,
J = 0.74 Hz, 6H); 19F NMR (377 MHz, CDCl3): d (ppm) = ꢂ109.71 (t,
J = 5.35, 5.35 Hz, 4F), ꢂ131.54 (m, 2F). Elemental analysis (CHN,
%): Calculated for C47H32F6N2S2, C 70.31, H 4.02, N 3.49; Found:
C70.10, H 4.04, N 3.44; ESI–HRMS [M]+: m/z calculated for C47H32-
F6N2S2, 802.1911, Found: 803.1986 (M+H+, 100%). For 5b, 1H NMR
(ppm) = 7.49 (d, J = 8.43 Hz, 1H), 6.95 (d, J = 2.12 Hz, 1H), 6.79 (s,
1H), 6.68 (dd, J = 8.44, 2.20 Hz, 1H), 3.64 (s, 1H), 2.54 (d, J = 1.23,
3H); Elemental analysis (CHN, %): Calculated for C9H9NS, C 66.22,
H 5.56, N 8.58, Found: C 65.98, H 5.46, N 8.49; ESI–HRMS [M]+:
m/z calculated for C9H9NS, 163.0456, Found: 164.0528 (M+H+,
100%).
2-Methyl-N,N-diphenylbenzo[b]thiophen-5-amine 2 [30]
Compound 1c (0.5 g, 3.06 mmol), iodobenzene (1.5 g,
7.35 mmol), actived Cu powder (0.84 g), anhydrous K2CO3 (fine
powder, 3.64 g), 18-Crown-6 (0.173 g) and 1,2-Dichlorobenzene
(10 mL) was added in reaction flask and heated rapidly to reflux
under intense stirring and N2 atomsphere for 24 h. The resulting
mixture was filtrated and washed with hot 1,2-Dichlorobenzene
for two times. The filtrate was distilled off most of 1,2-Dichloro-
benzene under vacuum at 60–70 °C. The residual 1,2-Dichloroben-
zene was removed by stream distillation. Solid powder (1.45 g)
was obtained. The crude solid was disolved in petroleum ether

B.-P. Wu et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 107 (2013) 39–45
45
(400 MHz, CDCl3): d (ppm) = 7.67 (t, J = 9.19, 9.19 Hz, 2H), 7.43 (dd,
J = 5.38, 1.94 Hz, 2H), 7.30 (d, J = 3.16 Hz, 2H), 7.27 (d, J = 3.77 Hz,
2H), 7.23 (d, J = 8.74 Hz, 4H), 7.15 (d, J = 7.51 Hz, 4H), 7.07 (ddd,
J = 12.97, 11.26, 4.89 Hz, 6H), 6.93 (d, J = 8.87 Hz, 2H), 6.86 (d,
J = 7.36 Hz, 2H); 19F NMR (377 MHz, CDCl3): d (ppm) = ꢂ109.68
(s, 2F), ꢂ109.83 (s, 2F), ꢂ131.55 (m, 2F); Elemental analysis
(CHN, %): Calculated for C47H32F6N2S2, C 70.31, H 4.02, N 3.49;
Found: C 70.09, H 3.99, N 3.52; ESI–HRMS [M]+: m/z calculated
for C47H32F6N2S2, 802.1911, Found: 803.1982 (M+H+, 100%).
852439). These data can be obtained free of charge from
www.ccdc.cam.ac.uk/conts/retrieving.html or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge, CB2 1EZ,
UK; Fax: (internet) +44 1223 336 033; Email: deposit@ccdc.cam.a-
c.uk. Supplementary data associated with this article can be found,
in the online version, at http://dx.doi.org/10.1016/j.saa.2013.
01.019.
References
Fluorescence measurements
[1] H. Niu, P. Luo, M. Zhang, L. Zhang, L. Hao, J. Luo, X. Bai, W. Wang, Eur. Polym. J.
45 (2009) 3058–3071.
[2] X. Li, Y.S. Kim, S.H. Kim, K. Jun, Y.A. Son, Fibers Polym. 10 (2009) 739–742.
[3] A. Iwan, D. Sek, Prog. Polym. Sci. 36 (2011) 1277–1325.
[4] D. Sek, E. Grabiec, H. Janeczek, B. Jarzabek, B. Kaczmarczyk, M. Domanski, A.
Iwan, Opt. Mater. 32 (2010) 1514–1525.
[5] K.C. Majumdar, N. Pal, Pradip Debnatha, N.V.S. Raob, Tetrahedron Lett. 48
(2007) 6330–6333.
[6] Y. Sun, N.C. Giebink, H. Kanno, B. Ma, M.E. Thompson, S.R. Forrest, Nature 440
(2006) 908–912.
[7] Y. Tao, C. Yang, J. Qin, Chem. Soc. Rev. 40 (2011) 2943–2970.
[8] Y.K. Kim, S.-H. Hwang, Synth. Met. 156 (2006) 1028–1035.
[9] F. Huang, Y.J. Cheng, Y. Zhang, M.S. Liu, A.K.Y. Jen, J. Mater. Chem. 18 (2008)
4495–4509.
[10] A.M. Thangthong, D. Meunmart, N. Prachumrak, S. Jungsuttiwong, T. Keawin, T.
Sudyoadsuk, V. Promarak, Chem. Commun. 47 (2011) 7122–7124.
[11] U. Bach, D. Lupo, P. Comte, J.E. Moser, F. Weissörtel, J. Salbeck, H. Spreitzer, M.
Gräzel, Nature 395 (1998) 583–585.
[12] J. Qian, Q.S. Liu, G. Li, K.J. Jiang, L.M. Yang, Y. Song, Chem. Commun. 47 (2011)
6461–6463.
Solid fluorescence was measured on KBr tablet. The sample tab-
let was placed 45° with the irradiate light and tilted in the vertical
direction. The sample-free tablet was selected to be set as blank va-
lue to deduct the interference of scattering light and second har-
monic. Fluorescence was detected in the direction of 90° with
the irradiation light. 3D spectrum was recorded at 2.5 nm of slit
width and 1200 nm/min (scanning speed).
Fluorescence quantum yield in solution was measured with
exciting wavelength at 365 nm. The quantum yield of DPA was
set to be 1.0 (its actual value is 0.98 in cyclohexane). In order to en-
sure the accuracy of the measurements, absorbance of the sample
solution should be less than 0.05. Determination of the fluores-
cence quantum yield was based on the following relation:
/x=/DPA ¼ FxADPA=FDPAAx
[13] M. Shin, H. Kim, S. Nam, J. Park, Y. Kim, Energy Environ. Sci. 3 (2010) 1538–
1543.
/x the quantum yield of the analyte, /DPA the quantum yield of the
standard material DPA, Fx the fluorescence intensity of analytes
(integral of selected peak), FDPA the fluorescence intensity of the
standard material DPA, ADPA the absorbance of the standard mate-
rial DPA at 365 nm, and Ax the absorbance of the analytes at
365 nm.
[14] W.L. Li, Chin. J. Liq. Cryst. Disp. 13 (1998) 136–140.
[15] Barbara Gigante, M. Alexandra Esteves, N. Pires, Matthew L. Davies, Peter
Douglas, Sofia M. Fonseca, Hugh D. Burrows, Ricardo A.E. Castro, Joao Pina, Joao
Seixas de Melo, New J. Chem. 33 (2009) 877.
[16] Y. Shirota, J. Mater. Chem. 10 (2000) 1–25.
[17] K. Danel, E. Gondek, M. Pokladko, I.V. Kityk, J. Mater. Sci.: Mater. Electron 20
(2009) 171–176.
[18] K. Danel, K. Ozga, I.V. Kityk, Chem. Phys. 313 (2005) 33–38.
[19] M. Makowska-Janusik, I.V. Kityk, N. Gauthier, F. Paul, J. Phys. Chem. C 111
(2007) 12094–12099.
Acknowledgments
[20] Y. Shirota, J. Mater. Chem. 15 (2005) 75–93.
[21] K. Inoue, Prog. Polym. Sci. 25 (2000) 453–571.
[22] Y.J. Wang, H.-S.h. Sheu, Ch.K. Lai, Tetrahedron 63 (2007) 1695–1705.
[23] Zh. Yang, B. Xu, J. He, L. Xue, Q. Guo, H. Xia, W. Tian, Org. Electron. 10 (2009)
954–959.
[24] C.W. Tang, S.A. Vanslyyke, Appl. Phys. Lett. 51 (1987) 913–951.
[25] (a) M.G. Martindill, The formulation of fluorescent coating, J. Oil Colour Chem.
Assoc. 72 (12) (1989) 485–486. 497;
(b) K. McLaren, The Colour Science of Dyes and Pigments, second ed., Bristol,
Adam Hilger Ltd., 1986. pp. 32–44.
[26] Wu Bian-Peng, Mei-Li Pang, Ting-Feng Tan, Ji-Ben Meng, J. Mol. Struct. 1032
(2013) 126–132.
This work was financially supported by grants from the Natural
Science Foundation of Tianjin (09JCYBJC06000), the Open Fund to
Large-scale Equipment of Tianjin Urban Construction Institute,
and the National Natural Science Foundation of China (Nos.
21102098 and 20971071).
Appendix A. Supplementary material
1H NMR and 13C NMR data of the analogue of 3, 4-bromo-N,N-
[27] H. Tian, T. Xu, Yongbo Zhao, Kongchang Chen, J. Chem. Soc. Perkin Trans. 2
(1999) 545–549.
[28] S. Gauthier, J.M.J. Frechet, Synthesis 4 (1987) 383–385.
[29] T. Maindron, Y. Wang, J.P. Dodelet, K. Miyatake, A.R. Hlil, A.S. Hay, Y. Tao, M.
D’Iorio, Thin Solid Films 466 (2004) 209–216.
bis(4-tert-butylphenyl)-2-methylbenzo[b]thiophen-5-amine,
is
available online as the supplementary data associated with this
article. Its crystallographic data for the structures has been depos-
ited with the Cambridge Crystallo graphic Data Centre (CCDC No.
[30] F.D. Hager, Org. Syn. 1 (1941) 544; 8 (1928) 116.