Phenothiazine and carbazole substituted pyrene based electroluminescent organic semiconductors for OLED devices

Article abstract of DOI:10.1039/c5tc03690a

Due to their easy availability, low cost and opportunities for exploiting reactions of bromo substituents, 1,3,6,8-tetrabromopyrene has attracted major attention in the organic electronics community for designing and constructing novel classes of pyrene b

Full text of DOI:10.1039/c5tc03690a

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DOI: 10.1039/C5TC03690A
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ARTICLE TYPE
Phenothiazine and Carbazole Substituted Pyrene Based
Electroluminescent Organic Semiconductors for OLED Devices
Jagadish K. Salunke,a, b F. L. Wong,c Krishna Feron,d Sergei Manzhos,e Ming Fai Lo,c Durgaprasad
Shinde,a Abhijeet Patil,a C. S. Lee,c V. A. L. Roy,*c Prashant Sonar*f , Prakash P. Wadgaonkar*a
5
Received (in XXX, XXX) XthXXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
Due to the easy availability, low cost and opportunities for
exploiting reactions of bromo substituents, 1, 3, 6, 8ꢀ
tetrabromopyrene has attracted major attention in organic
blue materials using various synthetic methodologies and
potential starting precursor building blocks. Among such
potential building blocks, pyrene conjugated system have
10 electronics community for designing and constructing novel 50 attracted considerable interest in the designing of small organic
classes of pyrene based organic semiconducting functional
materials. In the present work, 1, 3, 6, 8ꢀtetrabromo pyrene was
transformed into corresponding tetrasubstituted carbazole and
phenothiazine derivatives using the classical Suzuki coupling
molecules for different applications including OLEDs12ꢀ15 and
organic field effect transistors (OFETs)16ꢀ19 due to its fused four
aromatic condensed planar structure. Pyrene is a promising
chromophore with higher fluorescent quantum yield which makes
15 reaction. These newly synthesized materials with carbazole 55 it an attractive candidate for designing functional materials for
substituent (PY-CA) and phenothiazine substituent (PY-PH)
were characterised thoroughly and were successfully used as an
active lightꢀemitting layer in organic light emitting diodes which
resulted in blue and green emission with promising device
fluorescent probes and labeling experiments. Recently, N, Nꢀdiꢀpꢀ
methoxyphenylamineꢀsubstituted pyrene has been successfully
used as a hole transporting materials for perovskite based solar
20
cells with high efficiency. These examples clearly reveal that
20 performance. PY-CA exhibited maximum brightness around 60 pyrene is a versatile conjugated building block and can be used
2500 cd/m2 and power efficiency of 1.5 lm/W while PY-PH
exhibited 2116 cd/m2 brightness and power efficiency 0.45 lm/W
respectively.
for designing a variety of conjugated functional materials. Pyrene
posseses excellent thermal & chemical stability but on its own is
not a good candidate for light emitting devices due to its excimer
emission tendency which diminishes the fluorescence
65 efficiency.21,22 Nonetheless, this limitation of pyrene has been
overcome by introducing bulky groups with long alkyl chains
which enhances fluorescence quantum efficiency in OLEDs and
also reduces the aggregation of the final material. 23 Over the last
few years, our group has been exploring 1, 3, 6, 8 substituted
70 pyrene based conjugated molecular functional materials for
organic electronic devices. Initially, we reported a series of starꢀ
shaped organic semiconductors using bithiophene, phenylene,
thienothiophene, and benzothiadiazoleꢀthiophene chromophores.
Among them, 1, 3, 6, 8ꢀtetrakis (4ꢀbutoxyphenyl) pyrene, was
75 used as the active emitting layer in simple solutionꢀprocessed
OLEDs with deep blue emission (CIE= 0.15, 0.18) and maximum
efficiencies and brightness levels of 2.56 cd/A and 5000 cd/m2,
respectively.24 In our second attempt, we synthesized single,
double and triple bond incorporated three pyrene cored small
80 conjugated molecules with octyloxy naphthalene conjugated
substituent decorated at 1, 3, 6, 8 position of pyrene via Suzuki,
Heck and Sonogashira coupling reactions, respectively. The
effects of single, double and triple bonds on their optical,
electrochemical, and thermal properties were studied in detail and
Introduction
25
Since the discovery of organic light emitting diodes (OLEDs),
numerous classes of light emitting organic semiconductors have
been designed and developed and these efforts are still continuing
in order to find materials that are easy to synthesize and exhibit
improved solution processability and high efficiency.1ꢀ3 The
30 OLED technology has been used successfully for flat panel
display and solidꢀstate lighting applications.4,5 Still there is a
demand for the development of efficient pure red, blue, and green
light emitting materials for OLEDs. Blue light emitting materials
are also one of the important key elements for fabricating white
35 OLED devices. Conjugated building blocks such as antracene,6
9
pyrene,7 phenothiazine 8 and carbazole have been successfully
used for designing and synthesizing light emitting active layers
for OLED devices. However, current OLEDs still have some
problems to get pure strong emission with lower power
40 consumption which is determined by driving voltage and
efficiency of the devices. Low driving voltage and high efficiency
are required to reduce the power consumption of OLEDs.10 In
addition to the above issues, the electroluminescence properties
of blueꢀemitting materials remain challenging,11 particularly in
45 terms of easy availability, lower cost, efficiency, stability, and
color purity. Thus, it is very important to explore the new class of
25
85 all these materials were used successfully in OLEDs. In the
present work, we wish to report design, synthesis and
characterization of two new compounds 1, 3, 6, 8ꢀtetrakis(9ꢀ(4ꢀ
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DOI: 10.1039/C5TC03690A
methoxyphenyl)ꢀ9Hꢀcarbazolꢀ3ꢀyl)pyrene (PY-CA) and 1, 3, 6,
8ꢀtetrakis(10ꢀ(4ꢀmethoxyphenyl)ꢀ10Hꢀphenothiazinꢀ3ꢀyl)pyrene
(PY-PH). Although the carbazole and phenothiazine combination
into two necked round bottom flask containing chloroform (200
mL). After purging the reaction mixture for half an hour, Nꢀ
bromosuccinimide (3,58 g, 12 mmol) was added and the reaction
have been reported as an efficient deep blue and green emitting 60 mixture was stirred for 12 hr at room temperature. The solution
5
material in OLEDs earlier 26, 27 but so far there is no report in the
literature about using them in the form of tetraꢀfunctionalized
pyrene derivatives for any device application. Our results reveal
that introduction of carbazole and phenothiazine unit on
was poured into 500 mL of ice cold water and organic layer was
extracted with 100 mL of dichloromethane. The combined
organic layer was washed with 200 mL of water, dried over
anhydrous sodium sulfate and filtered. Removal of solvent on a
tetrabromopyrene core is the effective way to design wide band 65 rotary evaporator afforded a crude product which was then
10 gap electroluminescent materials. Upon using these materials in
OLED devices, carbazole substituted material exhibits blue
emission with electroluminescent peak at 493 nm whereas
phenothiazine substituted compound demonstrates green
emission with electroluminescent peak at 540 nm. The highest
15 brightness for carbazole and phenothiazine substituted pyrene
was measured in OLED devices and which was found around
2500 cd/m2 and 2116 cd/m2 respectively. The reported OLED
data clearly indicates that these classes of functional materials
hold a great promise for designing future cost effective and
20 efficient light emitting materials for OLED devices.
chromatographed on silica with petroleum ether as an eluent to
obtain title compound (5.51 g, 80 % yield), as a white solid. H
1
NMR (400 MHz, CDCl3) δ = 8.29 (d, J = 1.5 Hz, 1 H), 8.12 (d, J
= 7.8 Hz, 1 H), 7.60 ꢀ 7.41 (m, 4 H), 7.41 ꢀ 7.27 (m, 2 H), 7.26 ꢀ
70 7.09 (m, 3 H), 3.94 (s, 3 H).13C NMR (100 MHz , CDCl3) δ =
159.1, 140.9, 129.8, 127.1, 123.0, 122.1, 120.3, 115.2, 112.5,
111.2, 110.0, 77.1, 55.6.
Synthesis of 9-(4-methoxyphenyl)-3-(4,4,5,5-tetramethyl-
75 1,3,2-dioxaborolan-2-yl)-9H-carbazole (4): 3ꢀBromoꢀ9ꢀ(4ꢀ
methoxyphenyl)ꢀ9Hꢀcarbazole
(2
g,
1
mmol),
bis(pinacolato)diboron (1.4 g, 1.2 mmol), PdCl2(dppf) (418 mg,
0.1 mmol) and potassium acetate (1.6 g, 3 mmol) were added in
Schlenk tube under argon flow and then evacuated for half an
80 hour. Under an argon flow, anhydrous dioxane (25 mL) was
added to the reaction mixture. The solution was stirred at room
temperature for 30 min, and then at 80 °C for 24 h. The reaction
mixture was quenched by addition of iceꢀcold water (250 mL)
and then extracted with dichloromethane (250 mL). The
85 dichloromethane solution was washed with water, dried over
anhydrous sodium sulfate and filtered. Removal of solvent on a
Experimental
All chemicals (palladium catalysts, bis (pinacolato) diboron, Nꢀ
bromosuccinimide, 4ꢀiodoanisole, potassium acetate and 1, 3, 6,
25 8ꢀtetrabromopyrene) and solvents were purchased from Aldrich
and were used without further purification. All the reactions were
carried out using round bottom flask or Schlenk tube under an
argon or nitrogen atmosphere in anhydrous solvents. H and 13C
NMR spectra were recorded in CDCl3 on Bruker AC
30 spectrometer operating at 400 MHz for H and 100 MHz for 13C.
1
1
rotary evaporator afforded
a crude product which was
The chemical shifts are referenced to tetramethylsilane (TMS).
Matrix assisted laser desorption/ionization timeꢀof flight
(MALDIꢀTOF) mass spectra were obtained on a Bruker Autoflex
TOF/TOF instrument using dithranol as a matrix. Melting points
35 were recorded by open capillary method. UVꢀVis and
photoluminescence (PL) spectra were recorded on Jasco Vꢀ570,
and Cary Eclipse Fluorescence spectrofluorometer, respectively
using chloroform as a solvent.
chromatographed on neutral alumina with 2% dichloromethane in
petroleum ether as an eluent to obtain title compound (1.47 g, 65
90 % yield), as a yellow solid.1H NMR (400 MHz , CDCl3) δ = 8.63
(s, 3 H), 8.29 ꢀ 8.08 (m, 3 H), 7.84 (d, J = 8.2 Hz, 3 H), 7.53 ꢀ
7.20 (m, 19 H), 7.10 (d, J = 8.5 Hz, 6 H), 3.90 (d, J = 0.6 Hz, 3
H), 1.39 (s, 12 H). 13C NMR (100 MHz, CDCl3) δ = 159.5, 142.1,
132.9, 130.6, 128.7, 126.5, 123.7, 121.2, 115.7, 110.0, 84.2, 56.2,
95 25.5
40 Synthesis of 9H-carbazole-9-(4-methoxyphenyl) (2): Carbazole
(2 g, 50 mmol), 4ꢀiodoanisole (2.8 g, 60 mmol), copper powder
(0.536 g, 50 mmol), potassium carbonate (2.7 g, 100 mmol) and
triethylene glycol dimethyl ether (TEGDME) (30 mL) were
Synthesis
of
1,3,6,8-tetrakis(9-(4-methoxyphenyl)-9H-
carbazol-3-yl)pyrene (PY-CA):1,3,6,8ꢀTetrabromopyrene (0.5
g, 1 mmol), 9ꢀ(4ꢀmethoxyphenyl)ꢀ3ꢀ(4,4,5,5ꢀtetramethylꢀ1,3,2ꢀ
added into Schlenk tube and the mixture was stirred under the 100 dioxaborolanꢀ2ꢀyl)ꢀ9Hꢀcarbazole (2.31 g, 6 mmol), 2M K2CO3 (5
45 argon atmosphere at 180 °C for 24 h. The reaction mixture was
cooled to room temperature, filtered and poured into 500 mL of
ice cold water. The white precipitate was collected by filtration.
Recrystallization from 100 mL of methanol gave white crystalline
mL) and Pd(PPh3)4 (0.111 g, 0.1 mmol) were added in Schlenk
tube under argon flow. The flask was evacuated and refilled with
argon three times and then anhydrous THF (25 mL) was added
into the flask and reaction mixture was stirred at 80 °C for 48 h.
solid (2,27 g, 70 % yield): (mp = 153ꢀ154 °C; lit. 154ꢀ155°C) 105 The reaction mixture was extracted with dichloromethane (250
50 28.1H NMR (400 MHz ,CDCl3) δ = 8.14 ꢀ 8.01 (m, 2 H), 7.45 ꢀ
mL) and washed with water (500 mL) and dried over anhydrous
magnesium sulphate. Removal of solvent on rotary evaporator
afforded a crude product which was then purified using silica gel
column chromatography with 2% dichloromethane in petroleum
110 ether as an eluent to obtain title compound PY-CA (0.969 g, 78%
yield), as a green solid. 1H NMR (400 MHz ,) δ = 8.54 (s, 4 H),
8.38 (s, 10 H), 7.82 (d, J = 1.5 Hz, 4 H), 7.63 ꢀ 7.50 (m, 11 H),
7.14 (m, 8 H), 7.08 ꢀ 6.98 (m, 2 H), 7.03 (d, J = 9.0 Hz, 9 H), 3.84
(s, 3 H). 13C NMR (100 MHz, CDCl3) δ = 141.3, 128.5, 125.8,
123.0, 119.9, 115.0, 109.6, 55.6.
55 Synthesis of 3-bromo-9-(4-methoxyphenyl)-9H-carbazole (3):
9HꢀCarbazoleꢀ9ꢀ(4ꢀmethoxyphenyl) (5 g, 10 mmol) was added
2
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7.49 ꢀ 7.38 (m, 9 H), 7.28 (s, 4 H), 7.21 ꢀ 7.13 (m, 8 H), 3.96 (s,
7.19 (m, 3 H), 7.19 ꢀ 7.05 (m, 2 H), 6.97 (d, J = 9.1 Hz, 1 H),
6.80 (d, J = 3.8 Hz, 2 H), 6.14 (d, J = 8.0 Hz, 2 H), 3.91 (s, 3 H),
1.37 ꢀ 1.20 (m, 12 H) 13C NMR (100 MHz , CDCl3) δ = 159.2,
60 133.7, 132.9, 131.9, 126.6, 123.0, 122.5, 122.0, 115.3, 83.5, 55.5,
24.7.
12 H).13C NMR (100 MHz , CDCl3) δ = 158.9, 141.3, 137.8,
133.0, 129.6, 126.6, 123.0, 120.1, 115.1, 109.7, 55.6. MALDIꢀ
TOF: calculated 1288.00, found 1287.73.
Synthesis of 10-(4-methoxyphenyl)-10H-phenothiazine (6): A
mixture of phenothiazine (2 g, 50 mmol), 4ꢀiodoanisole (3.36 g,
60 mmol), copper powder (0.754 g, 50 mmol), potassium
carbonate (3.30 g, 100 mmol), and triethylene glycol dimethyl
5
Synthesis
of
1,3,6,8-tetrakis(10-(4-methoxyphenyl)-10H-
phenothiazin-3-yl)pyrene (PY-PH): 1,3,6,8ꢀTetrabromopyrene
(0.5 g, 1 mmol), 10ꢀ(4ꢀmethoxyphenyl)ꢀ3ꢀ(4,4,5,5ꢀtetramethylꢀ
ether (TEGDME) (30 mL) were added into Schlenk tube and the 65 1,3,2ꢀdioxaborolanꢀ2ꢀyl)ꢀ10Hꢀphenothiazine (2.49 g, 6 mmol),
10 mixture was stirred under the argon atmosphere at 180 °C for 24
h. The reaction mixture was cooled to room temperature, filtered
and poured into 250 mL of ice cold water. The brown precipitate
was collected by filtration. The product was purified by
2M aqueous K2CO3 (5 mL) and Pd(PPh3)4 (0.111 g, 0.1 mmol)
were added in Shlenck flask under argon flow. The flask was
evacuated and refilled with argon three times and then anhydrous
THF (25 mL) was added into the flask and reaction mixture was
recrystallization from ethyl acetate to afford yellowish crystalline 70 stirred at 80 °C for 48 h. The reaction mixture was extracted with
15 solid (1.83 g, 60 % yield): (mp = 170 °C; lit. 172−173 °C) 29.1H
NMR (400 MHz , CDCl3) δ = 7.54 ꢀ 7.36 (m, 2 H), 7.31 ꢀ 7.18
(m, 2 H), 7.18 ꢀ 7.07 (m, 2 H), 6.96 (dd, J = 2.1, 7.3 Hz, 4 H),
6.32 (d, J = 7.5 Hz, 2 H), 4.03 (s, 3 H).13C NMR (100 MHz,
CDCl3) δ = 55.6, 115.7, 116.3,118.9, 122.6, 126.7, 127.4, 132.1,
20 132.6, 144.2, 159.1
dichloromethane (250 mL) and washed with water (500 mL) and
dried over anhydrous sodium sulphate. Removal of solvent on
rotary evaporator afforded a crude product which was then
purified using silica gel column chromatography with 4%
75 dichloromethane in petroleum ether as an eluent to obtain title
1
compound PY-PH (0.819 g, 60% yield), as a yellow solid. H
NMR (400 MHz, CDCl3) δ = 8.13 (s, 4 H), 7.85 (s, 2 H), 7.53 ꢀ
7.23 (m, 14 H), 7.22 ꢀ 6.95 (m, 16 H), 6.95 ꢀ 6.71 (m, 7 H), 6.44 ꢀ
6.13 (m, 8 H), 3.94 (s, 12 H)13C NMR (100 MHz , CDCl3) δ =
80 159.3, 143.9, 44.5, 135.9, 135.0, 133.3, 132.3, 128.5, 126.8,
125.1, 122.4, 119.6, 115.7, 55.6ꢀ MALDIꢀTOF: calculated
1415,04. found 1415.37
OLED Device Fabrication:
OLED devices were fabricated using PY-CA and PY-PH active
85 emitting layer for evaluating the electroluminescent (EL)
Synthesis
of
3-bromo-10-(4-methoxyphenyl)-10H-
phenothiazine (7): 4ꢀPhenothiazineꢀ10ꢀylꢀanisole (2 g, 10 mmol)
was added into 250 mL two necked round bottom flask
containing chloroform ( 100 mL). After purging the reaction
25 mixture with argon for half an hour, Nꢀbromosuccinimide (1.28,
12 mmol) was added and the reaction mixture stirred for 12 h at
room temperature. The reaction mixture was poured into 250 mL
of ice cold water and extracted with dichloromethane. The
dichloromethane solution was washed with water, separated and
30 dried over sodium sulfate. Removal of solvent on rotary
performance.
The
OLED
device
configuration
evaporator afforded
chromatographed on neutral alumina with 2% ethyl acetate in
petroleum ether as an eluent to obtain title compound ( 2.14 g,
a
crude product which was then
glass/ITO/PEDOT: PSS/PY-CA or PY-PH/TPBi/Ca/Ag was
used. Patterned ITO glass substrates were routinely cleaned by
detergent and deionized water, then blown dry by nitrogen gas
1
o
85% yield), as a green solid. H NMR (400 MHz, CDCl3) δ =
90 and kept in a 110 C oven for 3 h before a 25 min ultraꢀviolet
35 7.43 ꢀ 7.22 (m, 2 H), 7.22 ꢀ 7.07 (m, 3 H), 7.07 ꢀ 6.75 (m, 4 H),
6.21 (d, J = 8.3 Hz, 1 H), 6.05 (dd, J = 5.6, 8.8 Hz, 1 H), 3.92 (s,
3 H) 13C NMR (100 MHz, CDCl3) δ= 159.4, 158.9, 132.0, 129.6,
128.7, 126.9, 122.6, 116.9, 116.0, 55.6.
ozone (UVO3) surface treatment. Filtered poly (3, 4ꢀ
ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS)
solution was spinꢀcoated on the patterned ITO glass substrates
o
and they were baked at 140 C for 20 min. The thickness of the
95 PEDOT: PSS films were controlled to 150 nm. Then PY-CA and
PY-PH solutions prepared in chloroform were separately spinꢀ
coated on the individual PEDOT: PSS coated ITO glass
substrates. They were baked at 70 oC for 20 min. The thickness of
both PY-CA and PY-PH films were controlled to 20 nm. All the
100 spinꢀcoat processes were performed in nitrogen glove box
environment. Both the PY-CA and PY-PH coated substrates
were then loaded into a thermal evaporation chamber at vacuum
pressure of below 3x10ꢀ6 Torr. 20 nm of 2, 2’, 2"ꢀ(1, 3, 5ꢀ
benzinetriyl)ꢀtris (1ꢀphenylꢀ1ꢀHꢀbenzimidazole) (TPBI), 20 nm of
105 calcium (Ca) and 100 nm of silver (Ag) were coated on the
substrates. With the completion of the device, EL measurements
were carried out. The EL emission spectra were measured using
PR650 CCD camera with a computer controller power supply
The voltageꢀcurrentꢀbrightness (IꢀVꢀB) characteristics and the
110 C.I.E. coordinates were also measured. The current and power
efficiencies were calculated from the IꢀVꢀB data of the devices.
Synthesis of 10-(4-methoxyphenyl)-3-(4, 4, 5, 5-tetramethyl-1,
40 3, 2-dioxaborolan-2-yl)-10H-phenothiazine (8):
3ꢀBromoꢀ10ꢀ(4ꢀmethoxyphenyl)ꢀ10Hꢀphenothiazine (2 g, 1
mmol), bis(pinacolato)diboron (1.59 g, 1.2 mmol), PdCl2(dppf)
(383 mg, 0.1 mmol) and potassium acetate (1.5 g, 3 mmol) were
added into Schlenk tube under argon flow and then evacuated for
45 half an hour. Under an argon flow anhydrous dioxane (25 mL)
was added to the reaction mixture. The solution was first stirred
for 30 min at room temperature, and then at 80 °C for 24 h. The
reaction mixture was quenched by addition of iceꢀcold water (250
mL) and then extracted with dichloromethane (250 mL). The
50 dichloromethane solution was washed with water, dried over
anhydrous sodium sulfate and filtered. Removal of solvent on
rotary evaporator afforded
a crude product which was
chromatographed on neutral alumina with 2% dichloromethane
in petroleum ether as an eluent to obtain title compound (1.21 g,
55 68% yield), as a green solid.1H NMR (400 MHz , CDCl3) δ =
7.42 (d, J = 1.4 Hz, 1 H), 7.35 –
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DOI: 10.1039/C5TC03690A
Schemeꢀ1
5
Schemeꢀ2
Reagents:ꢀ (i) 4ꢀIodoanisole, DMSO, Cu, K2CO3,180oC, 24 h (ii) NBS, CHCl3, R.T. 12h. (iii) Bis (pinacolato) diboron, Pd (dppf) Cl2.
KOAc, 80oC, 24 h. (IV) Pd (PPh3)4, K2CO3 (2M), THF, 80oC, 48 h.
Suzuki coupling conditions using 1, 3, 6, 8ꢀtetrabromopyrene and
10 Results and Discussion
In this work, two different conjugated segments viz carbazole and
monoboronic ester analogs (4) and (8) respectively. Syntheses of
phenothiazine were selected for attachment to the central pyrene 35 both final pyrene compounds are shown in Scheme 1 and Scheme
chromophore. In order to induce the solution processibility, a
methoxyphenyl group was attached to both the carbazole and
15 phenothiazine. First, commercially available compounds viz,
carbazole (1) and phenothiazine (5) were converted to 9Hꢀ
2. Both the derivatives were readily soluble in common organic
solvents such as dichloromethane, chloroform, toluene,
tetrahydrafuan, etc. This allowed purification of these compounds
by column chromatography. The purity of all the synthesized
carbazoleꢀ9ꢀ(4ꢀmethoxyphenyl) (2) and 10ꢀ(4ꢀmethoxyphenyl)ꢀ 40 precursors as well as final semiconductors were confirmed by 1H
10Hꢀphenothiazine (6), respectively in 70% and 60% yield via
Buchwald coupling using 4ꢀiodoanisole. Compound 2 and 6 were
20 then converted to their monobromo derivatives viz 3ꢀbromoꢀ9ꢀ(4ꢀ
NMR, 13C NMR and MALDIꢀTOF spectroscopy (see all the data
in Supporting Information). The optical properties of PY-CA and
PY-PH compounds were characterized in solution (chloroform)
by both UVꢀvis absorption (UV) and photoluminescence (PL)
methoxyphenyl)ꢀ9Hꢀcarbazole
(3)
and
(7)
3ꢀbromoꢀ10ꢀ(4ꢀ
using
methoxyphenyl)ꢀ10Hꢀphenothiazine
standard 45 spectroscopy (Figure 1). UVꢀvis spectra of both compounds
bromination conditions. Subsequent transformation of mono
bromo compounds (3) and (7) to their respective bisboronic ester
exhibit two absorption peaks respectively at shorter and longer
wavelengths. The absorption in the 300 nm to 500 nm region
clearly indicates the wide band gap nature of the compounds. PY-
CA exhibits two absorbance peaks at 339 nm and 400 nm
50 whereas PY-PH showed peaks at 340 nm and 450 nm,
respectively. The nearꢀidentical peaks at 339 nm and 340 nm are
the signature peaks for the central pyrene core and this is
comparable with absorbance of molecular pyrene (338 nm).
Compared to the pyrene core, PY-CA and PY-PH exhibits the
25 analogs
9ꢀ(4ꢀmethoxyphenyl)ꢀ3ꢀ(4,4,5,5ꢀtetramethylꢀ1,3,2ꢀ
dioxaborolanꢀ2ꢀyl)ꢀ9Hꢀcarbazole (4) and 10ꢀ(4ꢀmethoxyphenyl)ꢀ
3ꢀ(4,4,5,5ꢀtetramethylꢀ1,3,2ꢀdioxaborolanꢀ2ꢀyl)ꢀ10Hꢀ
phenothiazine (8) was carried out using bis(pinacolato)diboron
reagent. The target compounds 1, 3, 6, 8ꢀtetrakis(9ꢀ(4ꢀ
30 methoxyphenyl)ꢀ9Hꢀcarbazolꢀ3ꢀyl)pyrene (PY-CA) and 1,3,6,8ꢀ
tetrakis(10ꢀ(4ꢀmethoxyphenyl)ꢀ10Hꢀphenothiazinꢀ3ꢀyl)pyrene
(PY-PH) were prepared in 78% and 60% yield via classical 55 higher wavelength peaks at 400 nm and 450 nm respectively,
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which were arise from the enhanced conjugation between pyrene
optical data on ITO coated glass for PY-CA and PY-PH are
shown in Figure 3. The optical band gap light absorption onset
was determined by extrapolating the steepest slope to the
intersection of the absorption baseline (substrate). The band gap
core and the attached carbazole/phenothiazine moiety. The 50 nm
red shift in PY-PH compared to PY-CA is due to the more
extended conjugation length of phenothiazine than carbazole.
5
Both compounds show red shift of about 60 and 100 nm, 35 for PY-CA and PY-PH are 2.67 eV and 2.50 eV, respectively.
respectively, in their absorption maxima compared to the base
pyrene compound in solution state. The solution of PY-CA and
PY-PH under UVꢀlamp shows deep sky blue and green emission
(see Supporting Information). The peaks of the PL spectra of PY-
The observed optical band gaps are in a good agreement with our
earlier reported thienothiophene substituted pyrene PyꢀTtC9 (2.44
24
25
eV)
and naphthalene substituted pyrene PYꢀ1 (2.83 eV)
analogous compounds.
10 CA and PY-PH compounds were recorded at 450 nm and 500
nm, respectively. The observed PL maxima are 50 nm and 100
nm red shifted compared to the pyrene photoluminescence
spectra (PL max 393 nm).
UV spectrum of PY-CA
UV spectrum of PY-PH
1.0
0.8
0.6
0.4
0.2
0.0
400
500
600
700
Wavelength (nm)
40
PL spectrum of PY-CA
PL spectrum of PY-PH
1.0
0.8
0.6
0.4
0.2
0.0
400
500
600
700
Wavelength (nm)
15
Figure 2. UVꢀvis absorption (upper) and photoluminiscence
(lower) spectra of PY-CA and PY-PH compounds in thin film.
Figure 1. UVꢀvis absorption (upper) and photoluminiscence
(lower) spectra of PY-CA and PY-PH compounds in chloroform
solution (1x 10ꢀ4 M). PL was measured at the 370 nm excitation
wavalenegth.
45 The higher band gap value of PY-CA and PY-PH is a clear sign
of the wide band gap blueꢀgreen emitters. The energy levels of
PY-CA and PY-PH organic semiconductors were characterized
by the photoelectron spectroscopy in air (PESA) as shown in
Figure 4. Thin films of PY-CA and PY-PH were deposited on
50 the ITO coated glass by spin coating, which were used for the
determination the ionization potential. The photoelectron yield
ratio was measured with respect to the applied UVꢀenergy. The
onset point or slope across this graph gave the HOMO value of
these materials.30, 31 The HOMO value for the PY-CA and PY-
55 PH are 5.48 eV and 5.40 eV, as recorded by PESA. The lower
HOMO values of PY-CA and PY-PH are significant for making
air stable organic electronic devices. The higher HOMO of PY-
20 The thin film of PY-PH and PY-CA were spin coated on the
separate quartz substrates and were measured by UVꢀvis and PL
spectroscopy, which is shown in Figure 2. In the solid state, PY-
CA exhibits absorbance maxima at 425 nm whereas PY-PH
showed peaks at 450 nm, respectively. The value of the solid PY-
25 CA film is 25 nm red shifted compared to the solution
measurement. Thin film PL measurement of PY-CA and PY-PH
showed PL maxima at 485 nm and 520 nm respectively. The
optical band gap of these materials were measured by using spin
coated thin films of PY-CA and PY-PH compounds from
30 chloroform solution directly on ITO coated glass .The thin film
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PH compared to PY-CA is again attributed to the extended
conjugated moiety and electron rich sulfur of phenothiazine. This
observation is in good agreement with optical red shift and
optical band gap measured for PY-PH.
5
25
(b)
Figure 4 Photoelectro spectroscopy in air (PESA) analysis of
compound PY-CA (a) and PY-PH (b) compounds in thin film.
30
The absorption and PL spectra were computed with timeꢀ
dependent DFT (TDꢀDFT). 35 The PL spectra were computed by
optimizing the first excited state. The calculations were
performed in chloroform with the PCM (polarizable continuum
Figure 3. Optical band gap calculated using a thin film of PY-
CA (upper) and PY-PH (lower) spin coated on the ITO coated
10 glass substrates.
35 model) 36 model of the solvent. All calculations were performed
Density Functional Theory (DFT)32 calculations were performed
to compute molecular structures, the energies of frontier orbitals
37
using Gaussian 09.
The HOMO and LUMO of PY-PH and
PY-CA are shown in Figure 5 and Figure 6, respectively. In both
comopunds, the HOMO is more delocalized than the LUMO and
has appreciable amplitude on the phenothiazine and carbazole
40 moieties, respectively, while the LUMO is more localized on the
central fused pyrene core and partially on the fused backbone of
the PH or CA units. This also means that there is an appreciable
degree of charge transfer in the transition responsible for the first
peak in the absorption and PL spectrum (which we confirmed is
45 mostly due to HOMO → LUMO) which calls for the use of a
and their localization as well as absorption and
33
15 photoluminescence (PL) spectra. The B3LYP
and CAMꢀ
B3LYP 34 exchangeꢀcorrelations functionals were used with the
6ꢀ31g(d,p) basis set. These B3LYP and CAMꢀ B3LYP
correlations functionals were used because B3LYP provides more
reliable HOMO (highest occupied molecular orbital) and LUMO
20 (lowest unoccupied molecular orbital) energies which can be
compared to the measured redox levels, while the rangeꢀseparated
CAMꢀB3LYP is preferred for optical properties involving
transitions with significant degree of charge transfer.
rangeꢀseparated hybrid functional in the analysis of optical
38, 39
properties.
The calculated HOMO and LUMO energies of
(a)
PY-CA are ꢀ4.82 eV and ꢀ1.63 eV whereas for PY-PH, they are ꢀ
4.79 eV and ꢀ1.79 eV, respectively. The higher HOMO value for
50 PY-PH compared to PY-CA is related to the longer conjugation
6
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length of phenothiazine over carbazole. The HOMOꢀLUMO band
gap for PY-CA and PY-PH was calculated to be 3.18 eV and 3.0
eV, respectively. The computed contraction of the band gap in
PY-PH vs PY-CA of 0.18 eV matches well with the
experimentally measured difference in optical band gaps of 0.17
eV.
LUMO
5
LUMO
HOMO
HOMO
Figure 6. The electron density isocontours of HOMO and LUMO
35 of PY-PH obtained at the CAMꢀB3LYP level.
The device configurations of compounds PY-CA and PY-PH are
ITO/PEDOT:PSS(50nm)/PY-CA (50 nm)/TPBi (20 nm)/Ca (20
nm)/Ag (100) and ITO/PEDOT:PSS(50nm)/PY-PH (50
40 nm)/TPBi (20 nm)/Ca (20 nm)/Ag (100) respectively (see Figure
7). ITO coated glass and calcium with silver act as anode and
cathode respectively whereas 2,2',2"ꢀ(1,3,5ꢀbenzinetriyl)ꢀtris(1ꢀ
phenylꢀ1ꢀHꢀbenzimidazole) (TPBI) is an electron transporting
layer. When a potential is applied, holes are injected from anode
45 and electrons injected from the cathode respectively. Due to the
recombination of holes and electrons in the active emissive layer,
blue and green photon emission was observed in OLED devices.
The observed electroluminescence (EL) was recorded as shown
in Figure 7, while the EL performance data are given in Table 1.
50 The PY-CA device has an EL maximum of 493 nm emission
peak in the visible blue region with a full wave half maximum
(FWHM) of 80 nm and CIE coordinates of 0.19 and 0.42. While
the PY-PH device has an EL maximum of 540 nm in the visible
green region with a FWHM of 85 nm and CIE coordinates of
55 0.37 and 0.59. The PY-CA device shows turn on voltage (Von),
maximum current efficiency (CEmax), maximum power efficiency
(PEmax), maximum brightness (MBmax) of 3.3 V, 1.6 cd/A, 1.5
lm/W and 2500 cd/m2, respectively. Whereas the PY-PH device
exhibits Von, CEmax, PEmax and MBmax of 3.8 V, 1.1 cd/A, 0.45
60 lm/W and 2116 cd/m2. The power efficiency of the PY-CA
device is almost three times higher (1.5 lm/W) than the PY-PH
10
Figure 5. The electron density isocontours of HOMO and LUMO
of PY-CA obtained at the CAMꢀB3LYP level (visualization of
orbitals here and elsewhere by VESTA). 41
15 The absorption peak maximum computed with CAMꢀ
B3LYP/B3LYP is 379/437 nm for PY-CA and 389/471 nm for
PY-PH. The absorption spectra are shown in the Supporting
Information. The peaks computed using the two functionals
therefore straddle the measured peaks at 400 and 450 nm of PY-
20 CA and PY-PH, respectively (vide infra). This is expected, as
B3LYP is known to underestimate the excitation energy for large
40
conjugated systems and CAMꢀB3LYP to often overestimate it.
These calculations confirm the red shift of the peak with
phenothiazine vs carbazole which is observed experimentally.
25 The red shift was also confirmed for PL: the computed PL peaks
were 471 and 538 nm for PY-CA and PY-PH, respectively
(CAMꢀB3LYP, see Supporting Information). In order to test the
electroluminescent properties of PY-CA and PY-PH materials,
we used them as an active emissive layer in OLED devices.
30
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device (0.45 lm/W). The CE and PE characteristic of the PY-CA
and the PY-PH device is shown in Figure 8.
Unlike the case of the PY-CA device, the CE and PE curves of
the PY-PH device rollꢀoff more rapidly, the CE and PE drop to
50 oneꢀhalf of the CEmax and PEmax when the drive voltage is
increased from 8 V to 10 V. The overall higher performance of
PY-CA than PY-PH is attributed to the appropriate energy levels
for hole injection, better charge transporting and carrier mobility.
The observed OLED performances for both compounds are much
55 better than our previously reported naphthalene substituted
pyrene derivatives.25 The stable blue color output additionally
proves that PY-CA has high prospective to be a blue emitter in
OLED applications. The turn on voltage of 3.3 V also makes PY-
CA based OLED device energy efficient.
2x10-2
PY-CA
5
10
15
20
25
30
1x10-2
8x10-3
4x10-3
0
2
1
0
2
1
0
300
400
500
600
700
800
CE
PE
Wavelength (nm)
5x10-3
PY-PH
3x10-3
0
2
4
6
8
10
12
Voltage (V)
0
300
60
400
500
600
700
800
Wavelength (nm)
0.5
0.4
0.3
0.2
0.1
0.0
1.2
0.8
0.4
0.0
CE
PE
0
2
4
6
8
10
12
Voltage (V)
Figure 8. CE and PE characteristic of the PY-CA device (upper)
and the PY-PH device (lower).
Figure 7. Carbazole substituted pyrene PY-CA (upper) and
phenothiazine substituted pyrene PY-PH (middle) based
35 electroluminiscent spectrum and PY-CA or PY-PH light
The morphological behavior of PY-CA and PY-PH active layer
emitting layer deposited OLED device structure (lower).
65 thin film was characterized by atomic force microscopy (AFM)
as shown in Figure 9. The measured root mean square (RMS)
roughness of film samples was 2.32 nm for PY-CA and 1.06 nm
for PY-PH. The pristine ITO coated glass showed high surface
roughness with an RMS of 3.25 nm. Smooth film morphology of
As the voltage increase from 3 V to 4 V, both the CE and PE of
the PY-CA device increase rapidly to the CEmax and the PEmax of
40 1.6 cd/A and 1.5 lm/W respectively. As the drive voltage further
increases, the CE and PE curves of the PY-CA device rollꢀoff
less rapidly. However, the CE and PE of the PY-CA device still
remain at higher than oneꢀhalf of the CEmax and PEmax even as the
drive voltage is increased from 4 V to 11 V and 7.5 V,
45 respectively. As the voltage increases from 3.8 V to around 8 V,
both the CE and PE of the PY-PH device increase gradually to
the CEmax and the PEmax of 1.1 cd/A and 0.45 lm/W, respectively.
8
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Table1. Electroluminescent performance summary of PY-PH and PY-CA based OLED device
CIE
Power Efficiency
(lm/W)
Turn on
Voltage
(V)
Current
Efficiency
(Cd/A)
Electroluminescent
Peak (nm)
Max. Brightness
(cd/m2)
Device
PY-CA
3.3
1.5
(0.19,0.42)
493
540
2500
2116
1.6
1.1
3.8
0.45
(0.37, 0.59)
PY-PH
for light emission in terms of transportation of holes and electrons
in recombination zone.
Conclusions
20 In summary, we have successfully designed and synthesized a
new solution processable 1, 3, 6, 8ꢀ tetrasubstituted pyrene based
electroluminescent organic semiconductors namely PY-CA and
PY-PH via Suzuki coupling. PY-CA and PY-PH exhibited wide
UVꢀvis absorption starting in the region 300 nm to 500 nm with
25 an optical band gap of 2.67 eV and 2.50 eV, respectively. The
HOMO values of PY-CA and PY-PH thin films were determined
using PESA and were found to be 5.48 eV and 5.40 eV
respectively. PY-CA and PY-PH were used for OLED device
applications and their electroluminescence properties were
30 studied. The turn on voltage for both the devices was calculated
in the range of 3.3 V to 3.8 V. PY-CA exhibited blue emission
with electroluminescent peak at 493 nm, maximum brightness
around 2500 cd/m2 and power efficiency of 1.5 lm/W whereas
PY-PH shows green emission with electroluminescent peak at
35 540 nm, maximum brightness around 2116 cd/m2 and power
efficiency of 0.5 lm/W. The reported OLED data clearly indicate
that this class of functional materials hold a great promise for
designing future cost effective and efficient light emitting
materials for OLED devices. Further enhancements are expected
40 to obtain improved performance with optimized molecular and
device structure for OLED displays.
Acknowledgements
F. L. Wong, V. A. L. Roy is thankful to the Research Grants
Council of the Hong Kong Special Administrative Region
45 (Project No. T23ꢀ713/11). PS thanks to Queensland University of
Technology (QUT) and Australian Research Council (ARC) for
financial support (FT130101337). S.M. thanks to the Ministry of
Education of Singapore (AcRF grant). KF thanks the Australian
Renewable Energy Agency for financial support.
5
Figure 9. Atomic force microscope images of PY-CA (upper)
and PY-PH (lower) spin coated thin film on ITO coated glass.
PY-PH film compared to PY-CA might be attributed to the
10 more bulky phenothiazine group compared to carbazole moiety.
This is also one of the reasons why PY-CA exhibited better
OLED performance than PY-PH counterpart. The AFM images
of PY-CA and PY-PH clearly demonstrated the amorphous
nature of the thin film with complete coverage of microstructure
15 domains on the thin film. Thin film morphology plays crucial role
50 Notes and references
aPolymer Science and Engineering Division, CSIR-National Chemical
Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
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DOI: 10.1039/C5TC03690A
bCurrent Address: Department of Chemistry and Bioengineering,
Tampere University of Technology, P.O. Box 541, FI-33101 Tampere,
Finland
18. F. Liu, W. Y. Lai, C. Tang, H. B. Wu, Q. Q. Chen, B. Peng,
W. Wei, W. Huang and Y. Cao, Macromol. Rapid Commun.,
2008, 29, 659.
19. Y. Sagara, T. Mutai, I. Yoshikawa and K. Araki, J. Am.
Chem. Soc., 2007, 129, 1520.
20. N. J. Jeon, J. Lee, J. H. Noh, M. K. Nazeeruddin, M. Grätzel,
S. Seok, J. Am. Chem. Soc. 2013, 135, 19087
21. J. B. Birks, Photophysics of Aromatic Molecules, Wiley-
Interscience, London, 1970.
70 22. J. R. Lackowicz, Principles of Fluorescence Spectroscopy,
Kluwer Academic/Plenum Publishers, New York, 2 edn,
1999, pp. 595
23. M. T. FigueiraꢀDuarte, K. Mullen. Chem. Rev. 2011, 111,
7260.
5
cCenter of Super Diamond and Advanced Films, and Department of
Physics and Materials Science City, University of Hong Kong, Tat Chee
Avenue, Kowloon, Hong Kong
65
dCSIRO Energy Centre10 Murray Dwyer Circuit Mayfield West NSW
10 2304, Australia
eDepartment of Mechanical Engineering Faculty of Engineering,
National University of Singapore Block EA #07-08, 9 Engineering Drive
1, Singapore 117576
15
fSchool of Chemistry, Physics and Mechanical Engineering, Queensland
University of Technology(QUT), Brisbane, Australia
75 24. P. Sonar, M. S. Soh, Y. H. Cheng, J. T. Henssler, A.
Sellinger, Org. Lett., 2010, 12, 3292.
*Correspondence - sonar.prashant@qut.edu.au, sonarpm74@gmail.com
20
†Electronic Supplementary Information (ESI) available: NMR, MALDIꢀ
TOF MS data of compounds 2, 3, 4, 5, 6, 7, 8, PY-CA and PY-PH See
DOI: 10.1039/b000000x
25. J. K. Salunke, P. Sonar, F. L. Wong, V. A. L. Roy, C. S. Lee,
P. P. Wadgaonkar, Phys. Chem. Chem. Phys., 2014, 16,
23320.
80 26. S. J. Lee, J. S. Park, K.ꢀJ. Yoon, Y.ꢀI. Kim, S.ꢀH Jin, S. K.
Kang, Y.ꢀS. Gal, S. K., J. Y. Lee, J.ꢀW. Kang, SꢀH. Lee, H.ꢀ
D. Park, J.ꢀJ. Kim Adv. Funct. Mater. 2008, 18, 3922ꢀ3930.
27. G. B. Bodedla, K. R. J. Thomas, S. Kumar, J.ꢀH. Jou. C.ꢀJ. Li.
RSC Adv., 2015, 5, 87416ꢀ87428.
25 References
1
. C. W. Tang, S. A. Vanslyke, Appl. Phys. Lett. 1987 , 51 , 913
2. A. C. Grimsdale, K. L. Chan, R. E. Martin, P. G. Jokisz and A.
B. Holmes, Chem. Rev., 2009, 109, 897.
85 28. A. Matoliukstyte, J.V. Grazulevicius, J.A. Reina, V.
Jankauskas , E. Montrimas, Mater. Chem. Phys., 2006, 98,
324.
29. J. H. Huang, K. C. Lee ACS Appl. Mater. Interfaces 2014, 6,
7680−7685
30 3 L. S. Hung, C.H. Chen, Mat. Sci. Eng., R 2002 , 39 , 143.
4. J. Kido and Y. Okamoto, Chem. Rev., 2002, 102, 2357.
5. H.Uoyama, K. Goushi, K.Shizu, H. Nomura, C. Adachi,
Nature, 2012, 492, 234.
6. Y. H. Kim, H. C. Jeong, S. H. Kim, K. Yang, S. K. Kwon, Adv.
90 30. J. Jasieniak, M. Califano, S. E. Watkins, ACS Nano, 2011, 5,
35
40
45
Funct. Mater. 2005, 15, 1799.
588
7. Z. J. Zhao, S. M. Chen, J. W. Y. Lam, P. Lu, Y. C. Zhong, K.
S. Wong, H. S. Kwok, B. Z. Tang, Chem. Commun. 2010, 46,
2221.
8. X. Kong, A. P. Kulkarni, S. A. Jenekhe. Macromolecules 2003,
36, 8992.
9. K. R. J. Thomas, M Velusamy, J. T. Lin, Y. T. Tao, H. Chuen,
Adv. Funct. Mater. 2004, 14, 387ꢀ392.
10. Organic Light-Emitting Devices: Synthesis, Properties, and
Applications, ed. K. Muellen and U. Scherf, WileyꢀVCH,
2006, vol. 978.
31. M. Onoda, K. Tada, H. Nakayama, J. Appl. Phys. 1999, 86,
1999.
32. W. Kohn, L. J. Sham, Phys Rev, 1965, 40, A1133.
95 33. A.D. Becke, J. Phys, Chem., 1993, 5648
34. T. Yanai, D. Tew, N. Handy, Chem. Phys. Lett., 2004, 393,
51.
35. M. A. L. Marques MAL, Annu. Rev. Phys. Chem., 2004, 55,
427.
100 36. J. Tomasi, B. Mennucci, R. Cammi, Chem. Rev., 2006, 105,
2999.
37. M. J. Frisch (2009) Gaussian 09. Gaussian Inc., Wallingford.
38. M. J. G. Peach, P. Benfield, T. Helgaker, D.J. Tozer, J. Chem.
Phys. 2008, 128, 044118.
11. Z. Ma, P. Sonar and Z. K. Chen, Curr. Org. Chem., 2011, 14,
2034.
12. J. N. Moorthy, P. Natarajin, P. Venkatakrishnan, D. F. Huang
and T. J. Chow, Org. Lett., 2007, 9, 5215.
50 13. M. Y. Lo, C. G. Zhen, M. Lauters, G. E. Jabbour, A.
Sellinger, J. Am. Chem. Soc., 2007, 129, 5808.
14. R. D. Xia, W. Y. Lai, P. A Levermore, W. Huang, D. D. C.
Bradley, Adv. Funct. Mater., 2009, 19, 2844.
105 39. S. Manzhos, H. Segawa, K. Yamashita, Chem. Phys. Lett.
2013, 527, 51.
40. D. Jacquemin, V. Wathelet, E. A. Perpete, C. Adamo, J.
Chem. Theory Comput., 2009, 5, 2420.
41. K. Momma, F. Izumi, J. Appl. Crystallogr., 2011, 44, 1272.
110
15. Z. J. Zhao, J. H. Li, X. P. Chen, X. M. Wang, P. Lu, Y. Yang,
55
J. Org. Chem., 2009, 74, 383.
16. H. J. Zhang, Y. Wang, K. Z. Shao, Y. Q. Liu, S. Y. Chen, W.
F. Qiu, X. B. Sun, T. Qi, Y. Q. Ma, G. Yu, Z. M. Su, D. B.
Zhu, Chem. Commun., 2006, 755.
17. M. J. Sienkowska, J. M. Farrar, F. Zhang, S. Kusuma, P. A.
60 Heiney and P. Kaszynski, J. Mater. Chem., 2007, 17, 1399.
10|Journal Name, [year], [vol], 00–00
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Journal of Materials Chemistry C
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DOI: 10.1039/C5TC03690A
Phenothiazine and Carbazole Substituted Pyrene Based
Electroluminescent Organic Semiconductors for OLED Devices
b
Jagadish P. Salunke,a, F. L. Wong,c Krishna Feron,d Sergei Manzhos,e Ming Fai Lo,c
Durgaprasad Shinde,a Abhijeet Patil,a C. S. Lee,c V. A. L. Roy,*c Prashant Sonar*f , Prakash P.
Wadgaonkar*a
Table of Content
Br
Br
S
N
N
=
=
Br
Br
OMe
OMe
PY- CA
PY - PH
Two new solution processable 1, 3, 6, 8- tetrasubstituted pyrene based electroluminescent organic
semiconductors, namely PY-CA and PY-PH were designed and synthesized via Suzuki coupling.
Both PY-CA and PY-PH were used for OLED device applications and their electroluminescence
properties were studied in detail.