Synthesis and luminescent properties of poly(9-(3-Vinyl-phenyl)-phenanthrene)

Article abstract of DOI:10.1166/jnn.2016.12017

Recently, interest of polymer light-emitting diode (PLED) fabricated from conjugated polymer has augmented because PLED has advantage property that is well-suited to flexible lighting and solution processed device. In this presentation, we suggest a new polymer host based on phenanthrene, poly(9-(3-Vinyl-phenyl)-phenanthrene) (PVPP). It can be easily synthesized through simple synthetic methods which are Suzuki and Wittig reactions. PVPP film can be obtained from spin coating with solution used by common solvent. It exhibited PL maximum value of 381 nm and broad PL spectrum. Energy transfer smoothly occurred when the three dopants for green, red and yellow were used in PVPP.

Full text of DOI:10.1166/jnn.2016.12017

Article
Journal of
Nanoscience and Nanotechnology
Vol. 16, 1748–1751, 2016
Copyright © 2016 American Scientific Publishers
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Printed in the United States of America
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Synthesis and Luminescent Properties of
Poly(9-(3-vinyl-phenyl)-phenanthrene)
Garam Yang, Hayoon Lee, Suji Lee, Hyocheol Jung, Hwangyu Shin,
∗
Jaehyun Lee, and Jongwook Park
Department of Chemistry, The Catholic University of Korea, Bucheon, 420-743, Korea
Recently, interest of polymer light-emitting diode (PLED) fabricated from conjugated polymer has
augmented because PLED has advantage property that is well-suited to flexible lighting and solution
processed device. In this presentation, we suggest a new polymer host based on phenanthrene,
poly(9-(3-Vinyl-phenyl)-phenanthrene) (PVPP). It can be easily synthesized through simple synthetic
methods which are Suzuki and Wittig reactions. PVPP film can be obtained from spin coating
with solution used by common solvent. It exhibited PL maximum value of 381 nm and broad PL
spectrum. Energy transfer smoothly occurred when the three dopants for green, red and yellow
were used in PVPP.
Keywords: Polymer Light-Emitting Diodes (PLEDs), Luminescent, Phenanthrene.
Delivered by Publishing Technology to: McMaster University
IP: 200.59.58.19 On: Tue, 05 Jan 2016 09:14:23
Copyright: American Scientific Publishers
1
2
1
. INTRODUCTION
molecular aggregation. Moreover, phenyl and phenan-
threne groups were linked by meta position to sup-
press conjugation extension for maintaining deep blue
Polymer light emitting diodes (PLEDs) have been studied
for application of organic light emitting diodes(OLEDs)
1
13
in large size display. Also, PLEDs have attracted much
emission. The advantage of PVPP preparation includes
attention from academic and industrial fields as they are
applied to diverse areas such as flat-panel displays and
lightings.3 In particular, PLEDs manufactured using con-
facile synthesis methods such as Suzuki coupling and
Witting reaction.
–5
6
ꢀ7
jugated polymers have received great attention because
they have properties well-suited for flexible lightings: low
2
. EXPERIMENTAL DETAILS
2
.1. General Experiment
2
operating voltages, good processability, and facile color
Reagents and solvents were purchased as reagent grade
and used without further purification. All reactions were
performed using dry glassware under nitrogen atmosphere.
Analytical TLC was carried out on Merck 60 F254 silica
gel plate and column chromatography was performed on
Merck 60 silica gel (230–400 mesh).
turnability over the full visible range.
Many light-emitting polymers were synthesized and
studied, and performance of PLEDs has been improv-
ing significantly in recent years. Especially, blue OLED
8
was firstly fabricated with poly(para-phenylene) (PPP).
And several conjugated polymers including polyfluo-
9
10
renes (PFs), poly(p-phenylenevinylene) (PPVs), and
1
1
2.2. Synthesis of Compound 1
In a 500 ml round-bottom flask, 10 g of 9-bromo-
phenanthrene (38.89 mmol) was added and dissolved in
poly(phenan-threne) have been used for blue emitters.
However, many cases had maximum shift problem
of green emission, which is due to excimer formation,
molecular aggregation, and inter-chain attractions in the
1
50 ml of anhydrous tetrahydrofuran (THF) before stir-
ꢀ
ring. The reaction temperature was maintained at −76 C,
and 25.28 ml of 2.0 M n-butyllithium (50.59 mmol)
was slowly added to the reaction vessel. After about
ꢁ
-conjugated system. In this paper, we synthesized new
deep blue light-emitting polymer, poly(9-(3-Vinyl-phenyl)-
phenanthrene) (PVPP), as a blue host. PVPP has phenan-
threne and phenyl groups at side part to prevent effectively
1
0 minutes, 6.07 ml of trimethyl borate (54.45 mmol) was
added to the reaction vessel. Once the reaction temperature
increased to room temperature after about 1 hour, 7.12 ml
∗
Author to whom correspondence should be addressed.
1748
J. Nanosci. Nanotechnol. 2016, Vol. 16, No. 2
1533-4880/2016/16/1748/004
doi:10.1166/jnn.2016.12017

Yang et al.
Synthesis and Luminescent Properties of Poly(9-(3-vinyl-phenyl)-phenanthrene)
of 12 M HCl (85.56 mmol) was added. After the reac-
tion, the mixture was extracted using ethyl acetate (EA)
and distilled water. Water remaining in the organic layer
n-BuLi, (MeO)3B HO
B
Br
THF
HO
was dried with MgSO . The mixture was concentrated by
4
(1)
reduced pressure and re-precipitated with THF and hexane
to obtain white solid. The yield was 42%.
O
O
Pd(PPh3)4, K2CO3
THF
CH3P(C6H5)2Br, t-BuOK
THF
1
H-NMR (300 MHz, Chloroform) ꢂ(ppm): 8.75–8.71
(
1) +
(
(
t, 2H), 8.56–8.53 (d, 1H), 8.04 (s, 1H), 7.88–7.85
d, 1H), 7.61–7.52 (m, 6H), 5.79 (s, 3H).
Br
(3)
(2)
2
.3. Synthesis of Compound 2
n
In a 500 ml round-bottom flask, 3.3 g of Compound
Polymerization
1
2
(14.86 mmol), 0.69 g of Pd(PPh ꢃ (0.59 mmol) and
3 4
.08 mL of 3-bromobenzaldehyde (17.83 mmol) were
(3)
(4)
added and dissolved in 100 ml of anhydrous THF. When
the temperature increased to 80 C, 37.15 ml of 2 M
ꢀ
Scheme 1. Synthetic routes of PVPP.
K CO3 (74.31 mmol) was added to the reaction ves-
2
sel. After the reaction, the mixture was extracted using
toluene and distilled water. Water remaining in the organic
2
.5. Synthesis of Poly(9-(3-vinyl-phenyl)-
phenanthrene) (PVPP)
layer was dried with MgSO . The mixture concentrated by
4
reduced pressure was purified by primary column using
toluene solvent. The purified mixture was concentrated
again by reduced pressure and purified by secondary col-
umn using methylene chloride (MC):hexane = 1:2. The
purified product was concentrated by reduced pressure to
remove the solvent at room temperature and obtain solid
In a 100 ml round-bottom flask, 0.2 g of monomer
(
(
0.71 mmol) and 0.02
0.12 mmol) were added for nitrogen substitution and
g
of azobisisobutynitrile
dissolved in 4 ml of anhydrous benzene solvent. Poly-
merization was maintained at 50 C while stirring for
1
ꢀ
2 hours. After the reaction, the mixture was dissolved in
material in light yellow color. The yield was 38%.
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1
small amount of chloroform and recrystallized in excess
H-NMR (300 MHz, Chlor oI fPo :r m2 0) 0. ꢂ5 (9p . p5 m8 .) 1: 9 1O0 n. 1: 2Tue, 05 Jan 2016 09:14:23
Copyright: American S ac ci ee tno t ni f ei ct oP uo bb tl ai si nh ew r hs ite solid polymer. The yield was 55%.
(
(
(
s, 1H), 8.81–8.75 (m, 2H), 8.73–8.07 (m, 1H), 8.06–7.98
m, 1H), 7.97–7.90 (m, 1H), 7.89–7.80 (m, 2H), 7.73–7.66
m, 5H), 7.64–7.58 (m, 1H).
1
H-NMR (300 MHz, Chloroform) ꢂ(ppm) : 8.64–6.04
broad peaks, aromatic rings), 3.23–1.01 (alkyl groups).
(
2
.6. Characterization
2
.4. Synthesis of Monomer
1
H-NMR spectra were recorded using Bruker AM-300
spectrometer, and chemical shifts were recorded in ppm
unit. UV-Visible spectra were recorded with HP 8453 UV-
VIS-NIR spectrometer. Photoluminescence (PL) spectra
were measured using Perkin Elmer luminescence spec-
trometer LS50 (Xenon flash tube). The molecular weights
and polydispersities of the polymers were determined
by gel permeation chromatography (GPC) analysis using
In a 500 ml round-bottom flask, 6.65 g of methyltriph-
enylphosphonium bromide (18.61 mmol) and 2.24 g of
KOC(CH ꢃ (19.85 mmol) were added and dissolved in
3
3
1
1
50 ml of anhydrous THF. The solution was stirred for
ꢀ
hour at 0 C. Continuously maintaining the temperature
ꢀ
at 0 C, 3.5 g of Compound 2 (12.41 mmol) was dissolved
in 50 ml of anhydrous THF and slowly added to the reac-
tion vessel while stirring for 1 hour. If the reaction was
not complete, 6.65 g of methyltriphenylphosphonium bro-
mide (18.61 mmol) and 4.48 g of KOC(CH ꢃ (39.7 mmol)
chloroform solvent. Degradation temperatures (T ꢃ were
d
determined with thermogravimetric analysis (TGA) by
using a TGA4000 (PerkinElmer). Samples were heated to
3
3
ꢀ
were additionally added and stirred at 0 C. After the reac-
tion, the mixture was extracted using methylene chloride
ꢀ ꢀ
00 C at a rate of 10 C/min.
8
(
MC) and distilled water. Water remaining in the organic
layer was dried with MgSO . The mixture concentrated by
4
Table I. Synthesis of various PVPP.
reduced pressure was purified by column using developing
solvent of chloroform:hexane= 1:10. The purified product
was concentrated by reduced pressure and re-precipitated
using THF and hexane to obtain white solid material. The
yield was 10%.
a
b
c
M
(g)
S
(ml)
I
(g)
Mn
Mw
DP
0
0
0.2
0.2
.2
.2
4
4
4
4
0.01
0.02
0.04
0.06
–
–
–
29739
2048
708
48243
3877
943
1ꢄ62
1ꢄ89
1ꢄ33
1H-NMR (300 MHz, Chloroform) ꢂ(ppm): 8.76–8.68
(
(
m, 2H), 7.91–7.85 (m, 2H), 7.67–7.40 (m, 9H), 6.83–6.74
m, 1H), 5.83–5.77 (dd, 1H), 5.30–5.24 (m, 1H).
ꢀ
Notes: a: Monomer (g), b: solvent (mL), c: initiator (g), temperature: 50 C,
time: 12 h.
J. Nanosci. Nanotechnol. 16, 1748–1751, 2016
1749

Synthesis and Luminescent Properties of Poly(9-(3-vinyl-phenyl)-phenanthrene)
Yang et al.
0
0
0
0
.6
.4
.2
.0
120
80
40
0
Table II. Optical properties of monomer and PVPP.
monomer UV
polymer UV
monomer PL
polymer PL
a
b
Solution
Film
Compound
UVmax (nm) PLmax (nm) UVmax (nm) PLmax (nm)
Monomer
Polymer (PVPP)
296
301
374
379
307
305
379
381
Note: a. Chloroform solution (1×10− M), b. Spin coating film (1 wt%).
5
from NMR data, vinyl group protons were disappeared
and aromatic protons showed broad proton peak because
of polymer characteristics.
Polymer was obtained with high molecule weight and
small polydispersity value by changing initiator, solvent
2
50
300
350
400
450
500
Wavelength(nm)
(
benzene) and reaction temperature. In particular as shown
Figure 1. UV-Visible absorption and PL spectra of monomer (square)
and PVPP (triangle) in chloroform solution (1.0×10− M).
5
in Table I, equivalent weight change of initiator compared
to solvent amount and reaction temperature could opti-
mize molecular weight of polymer. Polymer having Mn of
2
.7. Luminescent Properties
3
0,000 was used in this study.
Figures 1 and 2 show UV-Visible (UV) absorption and
The polymer film was prepared by spin coating of the
polymer solution containing 1% by weight in toluene
solvent. Spinning was conducted with the condition of
photoluminescence (PL) spectra of PVPP and its monomer
in solution and film state, respectively. These data are sum-
marized in Table II. As shown in UV data of Table II,
monomer and polymer had similar maximum values of
296 nm and 301 nm in solution state, which indicate
characteristic peak of phenanthrene. In film state, maxi-
mum absorption values of monomer and polymer showed
1
000 rpm for 15 sec and 2000 rpm for 15 sec. As a
result of atomic force microscopy (AFM) for polymer film
morphology, roughness of root mean square (RMS) was
0
.359 nm. It means that film surface is smooth.
3
. RESULTS AND DIS DC e Ul i vS e Sr eI Od Nb y Publishing Technology to: McMaster University
07 nm and 305 nm respectively. The maximum values
3
IP: 200.59.58.19 On: Tue, 05 Jan 2016 09:14:23
Scheme 1 shows synthetic routes of PVPP. They consist
are mostly higher for the film state than in solution due to
the effects of molecule packing in the films.
Copyright: American Scientific Publishers
of simple three steps for monomer.
The main motivation for this new polymer is based on
suggestion of polymer host which has wide band gap and
is simply synthesized. Monomer can be obtained through
these three steps, and the polymer obtained by polymer-
ization can be used as host material. Especially, in order
to obtain wide band gap, PVPP has meta linkage between
phenyl group and phenanthrene group. Meta position has
advantage of squeezed conjugation length and relatively
PL maximum value of monomer and polymer had
74 nm and 379 nm in solution state, respectively. In
3
film state, PL maximum values of monomer and polymer
showed 379 nm and 381 nm. In film state is slightly red
shifted compared to solution state. This is the same reason
as mentioned above.
ꢀ
PVPP showed high Td value of 380 C by thermo-
gravimetric analysis (TGA). In order to check thermal sta-
bility of PVPP, PL spectrum of PVPP film was examined
1
3
wide band gap compared to ortho and para position. Also
ꢀ
ꢀ
after heating for 30 min under Ar gas with 100 C, 200 C,
0.5
0.4
0.3
0.2
0.1
0.0
800
monomer UV
polymer UV
monomer PL
polymer PL
600
400
200
0
250
300
350
400
450
500
550
Wavelength(nm)
Figure 2. UV-Visible absorption and PL spectra of monomer (square)
and PVPP (triangle) in spin coated film.
Figure 3. UV spectra of (•) C545T, (ꢀ) rubrene, (ꢁ) DCM in toluene
solution and the PL emission of (ꢂ) PVPP film as host.
1750
J. Nanosci. Nanotechnol. 16, 1748–1751, 2016

Yang et al.
Synthesis and Luminescent Properties of Poly(9-(3-vinyl-phenyl)-phenanthrene)
4
. CONCLUSION
As a new polymer host, PVPP was prepared by sim-
ple four steps of synthetic scheme. Spin coating film of
PVPP exhibited PL maximum value of 381 nm with broad
PL specctrum. Energy transfer happened well when three
dopants for green, red and yellow were used in PVPP.
PVPP can be a good candidate as a host emitter for solu-
tion processible white OLED.
Acknowledgment: This research was supported by a
grant from the Fundamental R&D Program for Core
Technology of Materials funded by the Ministry of
Trade, Industry and Energy, Republic of Korea (Project
No. 10050215).
Figure 4. PL spectra of PVPP film and PVPP films doped with various
dopants. ((ꢂ) PVPP, (•) PVPP+C545T 8%, (ꢀ) PVPP+rubrene 8%, (ꢁ)
PVPP+DCM 8%).
References and Notes
1
2
. J. Y. Lee, J. Ind. Eng. Chem. 14, 792 (2008).
. J. Y. Lee, M. H. Choi, D. K. Moon, and J. R. Haw, J. Ind. Eng.
Chem. 16, 395 (2010).
ꢀ
and 380 C. As a result, PL maximum values were in the
range of 381 to 384 nm indicating similar value of room
temperature condition. It means that PVPP has high ther-
mal stability which is applicable to display process.
3. H. J. Song, J. Y. Lee, I. S. Song, D. K. Moon, and J. R. Haw, J. Ind.
Eng. Chem. 17, 352 (2011).
4. (a) C. W. Tang and S. A. Vanslyke, Appl. Phys.Lett. 54, 913 (1987);
Highest occupied molecular orbital (HOMO) level and
lowest occupied molecular orbital (LUMO) of PVPP
was 5.97 eV and 2.15 eV respectively. Also band gap
was 3.82 eV. The HOMO energy level was determined
with ultraviolet photoelectron yield spectroscopy (AC-2).
LUMO level was calculated from the HOMO level and
(
b) Y. I. Park, B. J. Lee, K. H. J. H. Lee, S. Y. Oh, and J. W. Park,
Nanosci. Nanotechnol. 12, 4325 (2012).
5. (a) R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroghes, R. N.
Marks, C. Taliani, D. D. C. Bradley, D. A. Dos Santos, J. L. Bredas,
M. Logdlund, and W. R. Salaneck, Nature (London) 397, 121 (1999);
(b) J. S. Kang, S. K. Kim, J. Y. Jung, J. H. Lee, J. Y. Jaung, and
J. W. Park, Mol. Cryst. Liq. Cryst. 514, 171 (2009); (c) S. Kang,
J. H. Lee, S. Y. Oh, and J. W. Park, Mol. Cryst. Liq. Cryst. 462, 267
Delivered by Publishing Technology to: McMaster University
the optical band gap. The optical band gap was derived by
determining the absorption edges.
IP: 200.59.58.19 On: Tue, 05 Jan 2016 09:14:23
(2007).
Copyright: American Scientific Publishers
6
. P. L. Burn, A. B. Holmes, A. Kraft, D. D. C. Bradley, A. R. Brown,
Figure 3 shows the solution UV spectra of C545T,
DCM, rubrene which are dopants for green, red and yel-
low, respectively and PL emission of PVPP as a host. All
UV spectra of three dopants overlapped with PVPP emis-
sion. From this data, it is expected that when three dopants
were used with PVPP as a polymer host, energy transfer
can be available from host to dopant.
R. H. Friend, and R. W. Gymer, Nature 356, 47 (1992).
. A. Kraft, A. C. Grimsdale, and A. B. Holmes, Angew. Chem., Int.
Ed. 37, 402 (1998).
7
8. G. Grem, G. Leditzky, B. Ulrich, and G. Leising, Adv. Mater. 4, 36
1992).
. T. F. Guo, S. Pyo, S. C. Chang, and Y. Yang, Adv. Funct. Mater.
1, 339 (2001).
(
9
1
1
0. Y. Jin, J. Y. Kim, S. Song, Y. Xia, J. Kim, and H. Y. Woo, Polymer
As a results, Figure 4 shows the PL spectra of PVPP
spin-coated film, which was doped using 3 dopants
for green, red and yellow: C545T, DCM and rubrene.
When three dopants were used in PVPP host polymer,
energy transfer happened well from blue color to each
color.
49, 467 (2008).
11. R. Grisorio, G. P. Suranna, P. Mastrorilli, and C. F. Nobile, Org.
Lett. 9, 3149 (2007).
2. H. Lee, B. Kim, S. Kim, J. Kim, J. Lee, H. Shin, J. H. Lee, and
J. Park, J. Mater. Chem. C. 2, 4737 (2014).
3. Y. Park, S. Kim, J. H. Lee, D. H. Jung, C. C. Wu, and J. Park, Org.
Electronics 11, 864 (2010).
1
1
Received: 21 April 2015. Accepted: 27 May 2015.
J. Nanosci. Nanotechnol. 16, 1748–1751, 2016
1751