Supporting Information
to
Synthesis of Phenanthro[1,10,9,8-cdefg]carbazole-based
Conjugated Polymers for Organic Solar Cell Applications
So Min Park‡¶ Youngwoon Yoon, †,¶ Chan Woo Jeon, § Honggon Kim, † Min Jae Ko, † Doh-Kwon Lee, † Jin
Young Kim, † Hae Jung Son, †,* Soon-Ki Kwon, ‡* Yun-Hi Kim§* and BongSoo Kim †,*
†
Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST), Seoul
136-791, Republic of Korea
‡
School of Materials Science and Engineering, Engineering Research Institute, Gyeongsang National
University, Jinju 660-701, Korea
§
Department of Chemistry, Gyeongsang National University JinJu, 660-701, Korea
¶
These authors equally contributed to this work.
*
Corresponding author: E-mail: Hae Jung Son, †,* Soon-Ki Kwon, ‡* Yun-Hi Kim§* and BongSoo Kim †,*
General. All chemicals were purchased from Aldrich and used without further purification.
Compound 7 was prepared according to the reported synthetic method. [1] 1H NMR and 13C NMR
spectra were recorded using a Bruker Advance-300 spectrometer. The thermal analysis was
performed using a TA TGA 2100 thermo gravimetric analyzer under nitrogen atmosphere at a rate of
10 ℃/min. Differential scanning calorimeter (DSC) was conducted under nitrogen atmosphere using
a TA instrument 2100 DSC. The sample was heated at a rate of 10 ℃/min from 30 ℃ to 300 ℃.
UV–vis absorption spectra were measured using a UV-1650PC spectrophotometer. Molecular weights
and polydispersities of the
PPQ polymers were determined by gel permeation chromatography
(GPC) analysis (waters high-pressure GPC assembly Model M515 pump, u-Styragel columns of HR4,
HR4E, HR5E, with 500 and 100 Å, refractive index detectors). THF was used as an eluent and
polystyrene as a standard. Cyclic voltammetry (CV) was performed using an EG and G Parc model 273
Å
potentiostat/galvanostat
system
with
a
three-electrode
cell
in
an
acetonitrile
of
tetrabutylammonium perchlorate (Bu4NClO4) (0.1 M) with a scan rate of 50 mVs-1. The polymer films
were coated on a square carbon electrode by dipping the electrode into polymer solutions and then
dried under nitrogen protection. A Pt wire was used as the counter electrode, and an Ag/AgNO3 (0.1
M) electrode was used as the reference electrode. The conformations of model compounds of the
PPQ polymers in study were estimated by density functional theory (DFT) calculations. The model
compounds were geometrically optimized to an energy minimum using Gaussian 09 at the DFT B3LYP
level with a 6-31G(d) basis set.
Synthesis of monomers
1-Nitroperylene (1)
Perylene (30.0 g, 118.8 mmol) in 1,4-dioxane (1.2 L) was added into a mixture of water (24.0 mL) and
nitric acid (15.0 mL) dropwise. The resulting solution was heated at 60 °C with vigorous stirring for 30
min, and then cooled and poured into water (5 L). The solid was collected, washed, dried, and
purified by column chromatography (silica gel, methylene chloride/hexane=5/1) to get a brick-red
product. Yield: 8.1 g, 23%. 1H-NMR (DMSO): 8.57-8.53 (d, 2H), 8.04-7.95 (m, 4H), 7.84-7.68 (m, 4H),
7.60-7.58(t, 1H).
6H-phenanthro[1,10,9,8-cdefg]carbazole (2)
A solution of 1-nitroperylene (20.2 g, 68 mmol) and dissolved in triethyl phosphite (150 mL) was
reflux under nitrogen atmosphere for 6 h. After cooling to room temperature, a yellow-brown
product was obtained after recrystallization. Yield: 14.6 g, 81%. 1H-NMR (DMSO): 12.19 (s, 1H), 8.778.74 (d, 2H), 8.19-8.17 (d, 2H), 7.99-7.92 (d, 4H), 7.85-7.79 (t, 2H).
Scheme S1. Synthesis of 6H-phenanthro[1,10,9,8-cdefg]carbazole (PCB) monomer.
2-Decyltetradecyl 4-methylbenzenesulfonate (3)
A solution of 2-decyltetradecan-1-ol (30.0 g, 84.6mmol) dissolved in a mixture of pyridine (26.8 g,
338.8 mmol) and dichloromethane (15 mL) was stirred and cooled to below room temperature. Into
the reaction mixture, 4-methylbenzene-1-sulfonyl chloride (17.8 g, 93.3mmol) was added and then,
the reaction mixture was stirred at the same temperature for 3 hours. Large excess of a cold aqueous
hydrochloric acid solution was added into the reaction mixture and the organic part was extracted
using ethyl acetate. The organic layer was separated and dried with anhydrous magnesium sulfate.
The product was obtained by flash column chromatography (silica gel, hexane). Yield: 26.0 g, 60%.
1
H-NMR(CDCl3): 7.82-7.79 (d, 2H), 7.37-7.34 (d, 2H), 3.93-3.91 (d, 2H), 2.46 (s, 3H), 1.61-1.55 (m, 1H),
1.34-1.17 (m, 40H), 0.92-0.87 (t, 6H).
6-(2-Decyltetradecyl)- phenanthro[1,10,9,8-cdefg]carbazole (4)
6H-phenanthro[1,10,9,8-cdefg]carbazole (4.0 g, 15.8 mmol), NaH (0.6 g, 25 mmol), and 2decyltetradecyl 4-methylbenzenesulfonate (11.5 g, 22.6 mmol) were dissolved in tetrahydrofuran
(THF) (300 mL) and then, the resulting solution was stirred at 60 oC for 12 h under nitrogen
atmosphere. The reaction mixture was cooled to room temperature and poured into water. The
compound was extracted with dichloromethane and the solvent was evaporated under reduced
pressure. The crude product was purified by column chromatography (silica gel, hexane) to get a
yellow viscous product. Yield: 6.08 g, 64%. 1H-NMR (CDCl3): 8.68-8.66 (d, 2H), 8.15-8.13 (d, 2H), 7.947.92 (d, 2H), 7.85-7.79 (m, 4H), 4.59-4.57 (d, 2H), 2.29 (m, 1H), 1.45-1.19 (m, 40H), 0.91-0.86 (m, 6H).
4,8-Dibromo-6-(2-decyltetradecyl)- phenanthro[1,10,9,8-cdefg]carbazole (5)
6-(2-decyltetradecyl)-phenanthro[1,10,9,8-cdefg]carbazole (5.0 g, 8.3 mmol) was dissolved in
dichloromethane (100 mL). N-bromosuccinimide (NBS) (3.0 g, 16.8 mmol) dissolved in N,Ndimethylformamide (DMF) (50 mL) was added into the solution under dark condition and the
resulting reaction mixture was stirred at 20 °C for 5 h. The reaction mixture was then poured into
dichloromethane and the organic phase was washed with brine to remove DMF. The solvent was
evaporated under reduced pressure, and the crude product was purified by column chromatography
(silica gel, petroleum ether) to get a yellow compound. Yield: 2.7 g, 43%. 1H-NMR (CDCl3): 8.56-8.53
(d, 2H), 8.28-8.25 (d, 2H), 7.87-7.81 (m, 4H), 4.21-4.19 (d, 2H), 2.19-2.08 (m, 1H), 1.24-1.18 (m, 40H),
0.91-0.85 (m, 6H).
6-(2-Decyltetradecyl)-4,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)
phenanthro[1,10,9,8-
cdefg]carbazole (6)
n-Buthyl-lithium (5.2 ml, 13.0 mmol, 2.5 M solution in hexane) was added dropwise into a solution of
4,8-dibromo-6-(2-octyldodecyl)-phenanthro[1,10,9,8-cdefg]carbazole (3.8 g, 5 mmol) dissolved in
THF (100 mL) at -78 oC. The mixture warmed to 0 °C for 30 min and then, cooled down to –78 °C. 2isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2.6 g, 13.8 mmol) was added rapidly into the
solution and stirred at room temperature overnight. The mixture was quenched with water (50 mL)
and extracted with dichloromethane. The organic layer was washed with brine and dried over
anhydrous magnesium sulfate and concentrated in vacuum. The crude product was purified by
column chromatography (silica gel, petroleum ether/dichloromethane=3/1) to get a yellow solid.
Yield: 1.28 g, 30%. mp : 165 oC, 1H-NMR (CDCl3): 9.01-8.98 (d, 2H), 8.74-8.72 (d, 2H), 8.50 (s, 2H),
7.92-7.86 (m, 2H), 4.72 (d, 2H), 2.34 (m, 1H), 1.52 (s, 24H), 1.43-1.39 (m, 6H), 1.21 (m, 34H), 0.900.86 (m, 6H).
13
C-NMR (CDCl3): 133.23, 132.71, 132.69, 132.66, 131.50, 130.99, 125.33, 125.25,
125.15, 125.12, 124.53, 123.15, 122.68, 121, 12, 120.89, 120.56, 120.16, 84.00, 50.18, 40.14, 34.75,
32.18, 32.15, 32.07, 30.30, 30.06, 30.01, 29.98, 29.73, 26.85, 26.79, 25.47, 23.32, 23.05, 14.49. FT-IR
(KBr) (cm-1): 3063 (aromatic), 2925 (aliphatic, C-H), 1671 (aromatic, C=C), 1441 (aromatic, C-C), 817
(aliphatic, C-S). MS (FAB) calcd for C56H81B2NO4, 853.6 ([M]+); Found, 853.6
Scheme S2. Synthesis of quinoxaline monomers.
1,2-Bis(4-(octyloxy)phenyl)ethane-1,2-dione (8)
n-Buthyllithium (19.0 ml, 47.4 mmol, 2.5 M solution in hexane) was added dropwise into a solution
of 1-bromo-4-(octyloxy)benzene (12.3 g, 43.1 mmol) dissolved in THF (100 mL) at -78 oC. After the
mixture was stirred at -78 oC for 1h, 1,4-dimethylpiperazine-2,3-dione (3.0 g, 21.1 mmol) was added
into the reaction mixture at -78 oC. The resulting reaction mixture was stirred at -78 oC for 15 min and
then, further stirred at room temperature overnight. The mixture was poured into water, extracted
with ether, and dried over MgSO4. After concentrating the solution under reduced pressure, the
product was obtained by precipitation in methanol. Yield: 15.9 g, 79%. 1H-NMR (CDCl3): 7.96-7.93 (d,
4H), 6.97-6.94 (d, 4H), 4.06-4.02 (m, 4H), 1.84-1.79 (m, 4H), 1.62 (m, 4H), 1.48-1.44 (m, 4H), 1.331.30 (m, 12H), 0.90 (m, 6H).
5,8-Dibromo-2,3-bis(4-(octyloxy)phenyl)quinoxaline (9)
1,2-Bis(4-(octyloxy)phenyl)ethane-1,2-dione (1.26 g, 2.7 mmol) and 3,6-dibromobenzene-1,2diamine (0.8 g, 3.0 mmol) were dissolved in MeOH (30 mL). Into the mixture, acetic acid (1.5 mL) was
added and then, the mixture was stirred at reflux for 6 h. After evaporating the solvent, the mixture
was poured into water (100 mL) and extracted with chloroform. The organic layer was separated and
dried over anhydrous magnesium sulfate. The solvent was removed using a rotary evaporator and
then, the crude product was obtained by precipitation in methanol. Yield: 1.1 g, 58%. 1H-NMR
(CDCl3): 7.92 (s, 2H), 7.64-7.61 (d, 4H), 6.93-6.90 (d, 4H), 4.05-4.01 (m, 4H), 1.85-1.80 (m, 4H), 1.521.48 (m, 4H), 1.45-1.33 (m, 16H), 0.94-0.90 (m, 6H).
2,3-Bis(4-(octyloxy)phenyl)-5,8-di(thiophen-2-yl)quinoxaline (10)
5,8-dibromo-2,3-bis(4-(octyloxy)phenyl)quinoxaline
(1.74
g,
2.5
mmol)
and
2-(tri-
nbutylstannyl)thiophene (2.2 g, 5.9 mmol) were dissolved in toluene (100 mL). After nitrogen
bubbling for 30 min, tetrakis(triphenylphosphine)palladium (0) (0.07 g, 0.06 mmol) was added and
the reaction mixture was stirred at 100 oC overnight. The resulting reaction mixture was poured into
water (100 mL) and extracted with chloroform. After drying over anhydrous magnesium sulfate, the
solvent was evaporated and the residue was precipitated in MeOH several times. Yield: 1.3 g, 74%.
1
H-NMR (CDCl3): 8.17 (s, 2H), 7.91-7.90 (d, 2H), 7.75-7.72 (m, 4H), 7.58-7.54 (m, 2H), 7.24-7.21 (m,
2H), 6.96-6.93 (m, 4H), 4.07-4.02 (m, 4H), 1.86-1.81 (m, 4H), 1.50-1.46 (m, 4H), 1.37-1.34 (m, 16H),
0.93 (m, 6H).
5,8-Bis(5-bromothiophen-2-yl)-2,3-bis(4-(octyloxy)phenyl)quinoxaline (11)
Under dark condition, a solution of 2,3-bis(4-(octyloxy)phenyl)-5,8-di(thiophen-2-yl)quinoxaline (1.68
g, 2.4 mmol) in chloroform was cooled to 0 oC. Then NBS (0.85 g, 4.8 mmol) was added in small
portions over 10 min and then the mixture was stirred for 3 h. The mixture was poured into water
(100 mL) and extracted with chloroform. After drying over anhydrous magnesium sulfate, the solvent
was evaporated. The crude product was purified by crystallization with MeOH. Yield: 1.6 g, 77%. mp :
111 oC, 1H-NMR (CDCl3): 8.14 (s, 2H), 7.71-7.63 (m, 6H), 7.19 (d, 2H), 6.98-6.95 (m, 4H), 4.08-4.04 (m,
4H), 1.87-1.82 (m, 4H), 1.52-1.49 (m, 4H), 1.39-1.35 (m, 16H), 0.93 (m, 6H). 13C-NMR (CDCl3): 160.44,
160.14, 151.74, 139.74, 136.33, 131.92, 130.64, 130.26, 129.01, 125.30, 125.13, 116.93, 114.25,
113.02, 68.11, 31.84, 29.41, 29.31, 29.27, 26.10, 22.68, 14.12. MS (FAB) calcd for C44H48Br2N2O2S2 860
([M+H]+); Found, 861
1,2-Bis(3-(octyloxy)phenyl)ethane-1,2-dione (12)
Compound 12 was prepared using the same method as described for compound 8 using 1-bromo-3(octyloxy)benzene (12.3 g, 43.1 mmol). Yield: 13.3 g, 66%. 1H-NMR (CDCl3): 7.51-7.47 (m, 2H), 7.457.43 (m, 4H), 7.25-7.21 (m, 2H), 4.06-4.02 (m, 4H), 1.86-1.80 (m, 4H), 1.56-1.48 (m, 4H), 1.34-1.32 (m,
16H), 0.94-0.88 (m, 6H).
5,8-Dibromo-2,3-bis(3-(octyloxy)phenyl)quinoxaline (13)
Compound 13 was prepared using the same method as described for compound 9 using 1,2-bis(3(octyloxy)phenyl)ethane-1,2-dione (1.25 g, 2.7 mmol) and 3,6-dibromobenzene-1,2-diamine (0.8 g,
3.0 mmol). Yield: 1.1 g, 58%. 1H-NMR (CDCl3): 7.99 (s, 2H), 7.31-7.28 (m, 2H), 7.21-7.18 (m, 2H), 7.006.96 (m, 2H), 3.90-3.86 (m, 4H), 1.76-1.7 (m, 4H), 1.46-1.44 (m, 4H), 1.42-1.34 (m, 16H), 0.92 (m, 6H).
MS (FAB) calcd for C44H48Br2N2O2S2 860 ([M+H]+); Found, 861
2,3-Bis(3-(octyloxy)phenyl)-5,8-di(thiophen-2-yl)quinoxaline (14)
Compound 14 was prepared using the same method as described for compound 10 using 5,8dibromo-2,3-bis(3-(octyloxy)phenyl)quinoxaline (1.74 g, 2.5 mmol) and 2-(tri-butylstannyl)thiophene
(2.2 g, 5.9 mmol). Yield: 1.1 g, 63%. 1H-NMR (CDCl3): 8.16 (s, 2H), 7.94-7.92 (d, 2H), 7.58-7.56 (m, 4H),
7.36 (m, 2H), 7.30-7.28 (m, 2H), 7.24 (m, 2H), 6.98-6.96 (m, 2H), 3.94 (m, 4H), 1.79-1.77 (m, 4H), 1481.44 (m, 4H), 1.42-1.40 (m, 16H), 0.93 (m, 6H).
5,8-Bis(5-bromothiophen-2-yl)-2,3-bis(3-(octyloxy)phenyl)quinoxaline (15)
Compound 15 was prepared using the same method as described for compound 11 using 2,3-bis(3(octyloxy)phenyl)-5,8-di(thiophen-2-yl)quinoxaline (1.69 g, 2.4 mmol). Yield: 1.7 g, 82%. mp : 156 oC,
1
H-NMR (CDCl3): 8.09 (s, 2H), 7.57-7.56 (m, 4H), 7.14-7.11 (m, 2H), 7.01-7.00 (m, 4H), 6.98-6.97 (m,
2H), 4.08-4.04 (m, 4H), 1.85-1.80 (m, 4H), 1.53-1.51 (m, 4H), 1.35-1.31 (m, 16H), 0.91 (m, 6H). 13CNMR (CDCl3): 159.38, 151.79, 139.39, 136.31, 130.39, 129.01, 128.98, 127.23, 125.48, 125.41, 125.34,
122.93, 117.18, 115.15, 68.33, 31.87, 29.44, 29.36, 29.32, 26.20, 22.70, 14.13.
Synthesis of polymers
Synthesis of PPQP: PPQP was prepared via the palladium-catalyzed Suzuki coupling reaction.
The polymerization was carried out under nitrogen protection. Into a stirred solution of N-(2decyltetradecyl)-4,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-phenanthro[1,10,9,8cdefg]carbazole
(0.404
g,
0.47
mmol)
and
5,8-bis(5-bromothiophen-2-yl)-2,3-bis(4-
octyloxyphenyl)quinoxaline (0.404 g, 0.47 mmol) in 7 mL of toluene, a 2 M K2CO3 aqueous solution
(1.41 mL) and tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4) (0.01 g, 1.8 mol%) were added.
The resulting reaction mixture was heated at 95oC under nitrogen protection for 72 h. bromobenzene
(0.094 g, 0.6 mmol) was added with a small amount of Pd(PPh3)4 catalyst for end-capping and
refluxed for 24 h, then phenylboronic acid (0.098 g, 0.8 mmol) was added. After heating for 24 h, the
reaction mixture was poured into 50 mL methanol and filtered. The collected polymer was purified
by performing Soxhlet extraction with hexane, acetone, toluene, and chloroform. The purified
polymer was dissolved in CHCl3 and precipitated into methanol. Yield: 0.34 g, 57%. 1H-NMR (CDCl3):
8.75-8.73 (m, 4H), 7.94-7.76 (br, 14H), 6.87-6.86 (m, 4H), 3.94-3.92 (br, 6H), 1.73 (br, 6H), 1.20-1.12
(br, 59H), 0.87-0.83 (br, 12H). FT-IR (KBr) (cm-1): 3063 (aromatic), 2921 (aliphatic, C-H), 1650
(aromatic, C=C), 1410 (aromatic, C-C), 830 (aromatic, C-S).
Synthesis of PPQM: PPQM was prepared using a similar method as that for PPQP with
respective monomers of N-(2-decyltetradecyl)-4,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenanthro[1,10,9,8-cdefg]carbazole (0.404 g, 0.47 mmol) and 5,8-bis(5-bromothiophen-2-yl)-2,3bis(3-octyloxyphenyl)quinoxaline (0.404 g, 0.47 mmol). Yield: 0.28 g, 47%. 1H-NMR (CDCl3): 8.97-8.83
(br, 6H), 7.96-7.74 (br, 14H), 6.90-6.88 (br, 6H), 3.89-3.71 (br, 6H), 1.66 (br, 6H), 1.16-1.10 (br, 59H),
0.68-0.64 (br, 6H). FT-IR (KBr) (cm-1): 3053 (aromatic), 2907 (aliphatic, C-H), 1650 (aromatic, C=C),
1430 (aromatic, C-C), 807 (aromatic, C-S).
100
PPQP
o
Weight (%)
80
5 w% loss at 427 C
60
40
20
0
100
200
300
400
500
600
700
800
Temperature (°C)
100
Weight (%)
80
PPQM
o
5 w% loss at 383 C
60
40
20
0
100
200
300
400
500
600
700
800
Temperature (°C)
Figure S1. Thermorgravimetric analyses of polymers.
-1.6
1st heating
cooling
2nd heating
Heat Flow (W/g)
-1.8
PPQP
-2.0
-2.2
-2.4
-2.6
-2.8
60
90
120
150
180
210
240
Temperature (°C)
-2.2
Heat Flow (W/g)
-2.3
-2.4
1st heating
cooling
2nd heating
PPQM
-2.5
-2.6
-2.7
-2.8
-2.9
-3.0
-3.1
60
90
120
150
180
210
240
Temperature (°C)
Figure S2. Differential scanning calorimetry results of polymers.
Absorbance (a.u.)
1.0
0.8
0.6
0.4
0.2
0.0
PPQP
PPQM
400
500
600
700
800
Wavelength (nm)
Figure S3. Absorption spectra of PPQP and PPQM films prepared using a CB:DIO cosolvent.
MS (FAB) calcd for C56H81B2NO4
853.6 ([M]+); Found, 853.6
Figure S4. Mass spectrum of compound 6.
MS (FAB) calcd for C44H48Br2N2O2S2
860 ([M+H]+); Found, 861.2
Figure S5. Mass spectrum of compound 11.
MS (FAB) calcd for C44H48Br2N2O2S2
860 ([M+H]+); Found, 861.2
Figure S5. Mass spectrum of compound 15.
Reference
1. Westerhoff, U. T. M.; Zhou, M. J. Org. Chem. 1994, 59, 4988