Chemistry of Materials
Article
(
PPh ) (0.195 g, 0.17 mmol) were added to a 100.0 mL round-
7.65; N, 2.10; S, 16.85. The other three polymers were synthesized in a
similar manner.
3
4
bottom flask. The next procedure was similar to the procedure used
for 7-bromo-5-chloro-4-(thiophen-2-yl)benzo[c][1,2,5]thiadizole.
Yield: 57.1%. H NMR (400 MHz, CDCl ) δ: 8.16 (m, 1H), 7.99
−1
PBDTBO-ClBTDD. Yield: 74.7%. GPC: M
= 88.49 kg mol , M
=
w
n
1
−1
1
32.85 kg mol , PDI = 2.69. H NMR (400 MHz, CDCl ): δ 8.00 (b,
3
3
(
4
s, 1H), 7.64 (d, 1H, J = 4 Hz), 7.54 (d, 1H, J = 4 Hz), 7.25 (d, 1H, J =
Hz), 7.21 (d, 1H, J = 4 Hz), 1.43 (t, 1H, J = 6 Hz), 2.74 (t, 2H, J = 6
1H), 7.87 (b, 1H), 7.68 (b, 2H), 7.29 (b, 2H), 6.87 (b, 2H), 2.95 (b,
4H), 1.71 (b, 3H), 1.33 (b, 48H), 0.85 (b, 12 H). Anal. Calcd for
13
Hz), 1.73 (m, 2H), 1.29 (m, 18H), 0.89 (t, 3H, J = 8 Hz) . C NMR
100 MHz, CDCl ) δ: 155.0, 150.9, 142.9, 137.8, 134.1, 133.6, 132.5,
C H87ClN S (%): C, 68.50; H, 7.35; N, 2.35; S, 18.82. Found (%):
68 2 7
(
1
2
C, 68.03; H, 7.20; N, 2.34; S, 18.42.
3
−1
28.5, 128.1, 127.8, 126.0, 124.2, 122.9, 31.9, 30.5, 29.7, 29.6, 29.5,
PBDTHD-ClBTEH. Yield: 55.7%. GPC: M
w
= 58.57 kg mol , M
): δ 8.02 (b,
H), 7.90 (b, 1H), 7.73 (b, 2H), 7.31 (b, 2H), 6.88 (b, 2H), 2.86 (b,
H), 2.60 (b, 1H), 1.74 (b, 3H), 1.34 (b, 52H), 0.81 (b, 14 H). Anal.
n
=
−1
1
+
9.4, 22.7, 14.1. ESI-TOF-HRMS: m/z calcd for [M + H]
21.79 kg mol , PDI = 2.69. H NMR (400 MHz, CDCl
1
4
3
+
C H ClN S , 447.0794; found 447.0782. Anal. Calcd for
C H ClN S (%): C, 59.10; H, 5.19; N, 6.27; S, 21.52. Found
2
2
23
2 3
22
23
2 3
Calcd for C H ClN S (%): C, 68.27; H, 7.67; N, 2.24; S, 17.98.
(%): C, 58.94; H, 4.94; N, 6.35; S, 21.25.
72 95
2 7
Found (%): C, 67.74; H, 7.52; N, 2.14; S, 17.79.
Synthesis of Compound 5b. Synthesis of 5b was carried out in a
−1
1
PBDTBO-ClBTEH. Yield: 64.6%. GPC: M = 38.94 kg mol , M =
similar manner to that of 5a. H NMR (400 MHz, CDCl ) δ: 8.15 (m,
1
=
4
1
1
ESI-TOF-HRMS: m/z calcd for [M + H] C H ClN S , 503.1857;
found 503.1406. Anal. Calcd for C H ClN S (%): C, 62.06; H, 6.21;
N, 5.57; S, 19.12. Found (%): C, 61.76; H, 5.94; N, 5.75; S, 18.79.
Synthesis of Compound 6a. To a solution of compound 5a (2.19
g, 4.35 mmol) in THF (150 mL) was added N-bromosuccinimide
w
n
3
−1
1
1
7.50 kg mol , PDI = 2.23. H NMR (400 MHz, CDCl ): δ 8.00 (b,
H), 7.98 (s, 1H), 7.63 (s, 1H), 7.54 (d, 1H, J = 4 Hz), 7.25 (d, 1H, J
3
1
H), 7.87 (b, 1H), 7.70 (b, 2H), 7.29 (b, 2H), 7.29 (b, 2H), 2.82 (b,
4 Hz), 7.19 (d, 1H, J = 4 Hz), 2.67 (t, 1H, J = 8 Hz), 1.65 (d, 2H, J =
Hz), 1.34 (m, 12H), 0.94 (m, 6H) . 13C NMR (100 MHz, CDCl ) δ:
4H), 2.65 (b, 1H), 1.69 (b, 3H), 1.24 (b, 43H), 0.80 (b, 14 H). Anal.
Calcd for C H ClN S (%): C, 67.65; H, 7.01; N, 2.47; S, 19.75.
3
55.0, 150.9, 141.6, 137.7, 133.9, 133.6, 133.0, 128.4, 128.1, 127.8,
26.2, 124.3, 123.8, 118.7, 40.4, 34.7, 32.5, 28.8, 25.8, 23.1, 14.1, 11.1.
64 79
2 7
Found (%): C, 67.64; H, 6.72; N, 2.24; S, 19.49.
Measurement and Characterization. H and 13C NMR spectra
were recorded on Bruker Avance-400 spectrometers. All chemical
shifts (δ) are reported in units of ppm with tetramethylsilane (TMS)
as the internal standard. The following abbreviations were used for
signal multiplicities: s, singlet; d, doublet; t triplet; m, multiplet.
Electrospray ionization−high-resolution mass spectrometry (ESI-
HRMS) experiments were conducted on an applied Q EXACTIVE
mass spectrometry system. The elemental analyses (C, H, N, and S) of
the new compounds and the polymers were measured by using a
FLASH EA1112 elemental analyzer. The molecular weight and
molecular weight distribution of the synthesized polymers were
measured via gel permeation chromatography (GPC) at 40 °C on a
Malvern Viscotek 270 max system equipped with a UV detector, using
polystyrene (Aldrich) as the standard and THF as the eluent. The
optical absorption spectra of solution and thin film were measured
with a UV-vis-IR spectrophotometer (Shimadzu, Model UV3600).
The thin films of the polymers were spin-coated from their solutions in
chloromethane, and the film absorption spectra were measured. Cyclic
voltammetry was performed on a Model CHI 660E potentiostat/
galvanostat (Shanghai Chenhua Instrumental Co., Ltd. China) to
determine the IP and EA of the polymers, in an acetonitrile solution of
1
+
+
26
31
2 3
26
31
2 3
(
NBS, 1.70 g, 9.57 mmol) in a one-neck round flask. The mixture was
then stirred overnight at room temperature. After the solvent was
distilled, the residue was purified by silica gel column chromatography,
using PE-DCM (v/v, 4/1) as an eluent, to yield 6a as a red solid (2.48
g, 86.5%). H NMR (400 MHz, CDCl ) δ: 7.88 (s, 1H), 7.82 (d, 1H, J
1
3
=
4 Hz), 7.63 (s, 1H), 7.19 (d, 1H, J = 4 Hz), 2.68 (t, 2H, J = 8 Hz),
.69 (m, 2H), 1.41 (m, 20H), 0.90 (m, 18H), 0.90 (t, 3H, J = 6 Hz).
1
1
3
C NMR (100 MHz, CDCl ) δ: 154.4, 150.6, 141.9, 138.8, 134.0,
3
1
2
33.4, 132.4, 130.8, 128.2, 127.5, 125.4, 123.4, 116.1, 112.9, 31.9, 29.7,
+
9.6, 29.4, 29.3, 22.7, 14.1. ESI-TOF-HRMS: m/z calcd for [M + H]
+
C H Br ClN S , 604.8715; found, 604.8964. Anal. Calcd for
C H Br ClN S (%): C, 43.68; H, 3.50; N, 4.63; S, 15.90. Found
(
2
2
21
2
2 3
22
21
2
2 3
%): C, 44.63; H, 3.61; N, 4.45; S, 15.68.
Synthesis of Compound 6b. Synthesis of 6b was carried out in a
1
similar manner to that of 6a. H NMR (400 MHz, CDCl ) δ: 7.89 (s,
1
3
H), 7.82 (d, 1H, J = 4 Hz), 7.61 (s, 1H), 7.19 (d, 1H, J = 4 Hz), 2.63
−1
−1
0
.1 mol L n-Bu NPF at a potential scan rate of 100 mV s with an
4 6
(
t, 2H, J = 8 Hz), 1.72 (t, 2H, J = 6 Hz), 1.38 (m, 8H), 0.93 (m, 6H).
+
Ag/Ag reference electrode and a platinum wire counter electrode
under an argon atmosphere. Polymer films were deposited from
chloroform solutions on a glass carbon working electrode (2 mm in
diameter). The redox potential of ferrocene/ferrocene+ (Fc/Fc )
under the same conditions is located at 0.044 V, which is assumed to
have an absolute energy level of −4.8 eV to vacuum. The IP and EA
were calculated by the following equation:
1
3
C NMR (100 MHz, CDCl ) δ: 155.0, 150.9, 141.6, 137.7, 133.9,
3
1
3
33.6, 133.0, 128.4, 128.1, 127.8, 126.2, 124.3, 123.8, 118.7, 40.4, 34.7,
+
2.5, 28.8, 25.8, 23.1, 14.1, 11.1. ESI-TOF-HRMS: m/z calcd for [M +
+
+
2 3
H] C H Br ClN S , 660.9779; found, 660.9587. Anal. Calcd for
C H Br ClN S (%): C, 47.24; H, 4.42; N, 4.24; S, 14.55. Found
(
26
29
2
26
29
2
2 3
%): C, 47.55; H, 4.33; N, 4.36; S, 14.78.
Synthesis of Polymers. Synthesis of PBDTHD-ClBTDD. (4,8-
IP (eV) = − (φ + 4.74)
Bis(5-(2-hexyldecyl)thiophen-2-yl)benzo[1,2-b:4,5-b′]dithiophene-
,6-diyl)bis(trimethylstannane) (550.7 mg, 0.487 mmol) was weighed
into a 50-mL one-neck round-bottom flask. Compound 5a (322.4 mg,
.487 mmol), Pd dba (17.86 mg, 0.019 mmol), and P(o-tol) (23.75
ox
2
EA (eV) = − (φred + 4.74)
0
+
2
3
3
where φox is the onset oxidation potential vs Ag/Ag and φ is the
onset reduction potential vs Ag/Ag . DFT calculations were carried
out at the ωB97X-D/6-31+G(d,p) level in the Gaussian 09 package.
red
mg, 0.078 mmol) were added. The flask was subjected to three
successive vacuum cycles, followed by refilling with argon. Anhydrous
chlorobenzene (36.58 mL) then was added via a syringe. The
polymerization was carried out at 130 °C for 18 h under argon
protection. The mixture then was cooled to room temperature, and the
polymer was precipitated via the addition of 200 mL of methanol,
filtered through a Soxhlet thimble, and then subjected to Soxhlet
extraction with methanol, hexane, acetone, dichloromethane, and
chloroform. The polymer solution was condensed to ∼5 mL and
slowly poured into methanol (200 mL). The precipitate was collected
and dried under vacuum overnight to yield PBDTHD-ClBTDD
+
44
Tapping mode atomic force microscopy (TM-AFM) images were
taken on a NanoScopeIIIa controller (Veeco Metrology Group/Digital
Instruments, Santa Barbara, CA), using built-in software (version
V6.13R1) to capture images. The thickness of the blend films was
determined by a Dektak 6 M surface profilometer. All J−V curves were
captured under an AAA solar simulator (SAN-EI) calibrated by a
standard single-crystal Si photovoltaic cell (certificated by the National
Institute of Metrology). All EQE data were gained through the
measurement of solar cell spectral response measurement system
(Model QE-R3011, Enli Technology, Ltd., Taiwan). The hole mobility
of the active layers was measured by the space charge limited current
(SCLC) method. The device structure for hole-only is ITO/
PEDOT:PSS/polymer:PC BM/MoO /Ag. The processing condi-
−
1
−1
(
607.2 mg, 69.6%). GPC: M = 113.8 kg mol , M = 36.69 kg mol ,
w
n
1
PDI = 3.10. H NMR (400 MHz, CDCl ): δ 8.00 (b, 1H), 7.87 (b,
3
2
4
H), 7.71 (b, 2H), 7.31 (b, 2H), 6.88 (b, 2H), 2.84 (b, 4H), 1.71 (b,
H), 1.33 (b, 60 H), 0.78 (b, 10 H). Anal. Calcd for C H103ClN2S7
7
6
71
3
(%): C, 69.97; H, 7.96; N, 2.15; S, 17.21. Found (%): C, 68.85; H,
tions used for the active layers were the optimized ones. Charge
I
Chem. Mater. XXXX, XXX, XXX−XXX