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5
(
V ). Moreover, the strong electronegativity of the fluorine
1-Bromo-3-((2-hexyldecyl)oxy)benzene (2)
3
3-Bromophenol (3.9 g, 22.7 mmol), K CO (13.0 g, 94.2
oc
atom gives rise to non-covalent attractive interactions
between F and hydrogen or sulfur atoms (FꢀꢀꢀH or FꢀꢀꢀS),
resulting in polymer chains with strong inter/intramolecular
interactions. Exploiting these effects in the design of conju-
gated polymers might lead to an improvement in the perfor-
mance of PSCs.
2
mmol), and 2-hexyldecyl 4-methylbenzenesulfonate 1 (7.5 g,
18.9 mmol) were dissolved in DMF (200 mL) and the result-
ing solution was stirred at 110 8C for overnight. The reaction
mixture was cooled to room temperature and filtered. The
filtrate was extracted with distilled water and diethyl ether.
The organic extracts were dried over anhydrous magnesium
sulfate, and the solvent was removed under reduced pres-
sure. The crude product was purified by silica gel column
6
Generally, a conjugated polymer is composed of two main
components (the p-conjugated backbone and the side
chains), and they both need to be carefully considered in the
design of new conjugated polymers. Furthermore, it is con-
structive to investigate the synergistic effect of altering both
the conjugated backbone and the side chains on the photo-
voltaic properties, in an attempt to further understand the
structure–property relationship.
1
chromatography to give 2 as a colorless oil (6.0 g, 80%). H-
NMR (400 MHz, CDCl ) d (ppm): 7.12 (t, J 5 8.2 Hz, 2H),
3
7
.05 (m, 2H), 6.83 (dd, J 5 8.1 Hz, 1H), 3.80 (d, 2H), 1.75 (m,
H), 1.41-1.26 (m, 24H), 0.88 (m, 6H). Elemental Anal. Calcd.
for (C22 37BrO): C, 66.49; H, 9.38. Found: C, 68.12; H, 9.57.
1
H
1
,2-Bis(3-((2-hexyldecyl)oxy)phenyl)ethane-1,2-dione (3)
In this study, four new D-A type copolymers such as PQxBT,
PQxFBT, TQxBT, and TQxFBT were designed and synthe-
sized successfully. We investigated the effect of (i) using a
fluorinated bithiophene (FBT) as the electron donating unit
and (ii) varying the side-chain moieties tethered to quinoxa-
line (Qx) as the electron withdrawing group in the polymer
backbone, on the physical properties, molecular orientation,
crystallinity, and photovoltaic performance. In particular,
TQxFBT exhibited the face-on orientation in the film state,
as observed by grazing incidence X-ray diffraction and a
well-mixed nano-sized small grain morphology in
TQxFBT:PC BM blend films, corresponding to a photovolta-
n-BuLi (6.8 mL, 18.9 mmol, 2.5 M solution in hexane) was
added dropwise into a solution of 1-bromo-3-((2-hexyldecy-
l)oxy)benzene 2 (6.0 g, 15.1 mmol) dissolved in THF
(
50 mL) at 278 8C. The mixture was stirred at this tempera-
ture for 1 h, followed by addition of 1,4-dimethylpiperazine-
,3-dione (1.07 g, 7.5 mmol). The resulting reaction mixture
2
was stirred at 278 8C for 20 min and then stirred at room
temperature overnight. The mixture was poured into water,
extracted with diethyl ether, and dried over anhydrous mag-
nesium sulfate. After concentrating the solution under
reduced pressure, the product was purified by silica gel col-
7
1
umn chromatography to give compound 3 as yellow oil
ic device with the highest PCE of 4.18% .
1
(
3.78 g, 78%). H-NMR (400 MHz, CDCl ) d (ppm): 7.52 (m,
3
2
H), 7.44 (d, J 5 7.8 Hz, 2H), 7.38 (t, J 5 7.4 Hz, 2H), 7.19
EXPERIMENTAL
(dd, J 5 7.8 Hz, 2H), 3.88 (m, 4H), 1.70 (m, 2H), 1.43-1.27
Materials
(m, 48H), 0.88 (m, 12H). Elemental Anal. Calcd. for
(C H O ): C, 79.95; H, 10.79. Found: C, 78.52; H, 9.98.
All chemicals were purchased from Sigma-Aldrich, Acros
Organics, and Alfa Aesar and used without further purifica-
tion. 1,4-Dimethylpiperazine-2,3-dione, 3,6-dibromobenzene-
4
6 74 4
5,8-Dibromo-2,3-Bis(3-((2-
hexyldecyl)oxy)phenyl)quinoxaline (M1)
Compound 3 (1.06 g, 1.5 mmol) and 3,6-dibromobenzene-
1,2-diamine, and compounds M3 and M4 were prepared
7
according to reported literature procedures.
1,2-diamine (0.41 g, 1.5 mmol) were dissolved in acetic acid
Synthetic Procedures
(30 mL) and stirred at reflux for 6 h. After cooling to room
temperature, the reaction mixture was poured into water
and extracted with CH Cl . The organic layer was dried over
2 2
2
-Hexyldecyl 4-methylbenzenesulfonate (1)
A solution of p-toluenesulfonyl chloride (4.3 g, 22.7 mmol)
in CH Cl (20 mL) was added dropwise to a cold solution of
2
2
anhydrous magnesium sulfate. The solvent was removed
under reduced pressure, and the crude product was purified
by silica gel column chromatography. Product M1 was
2
5
-hexyl-1-decanol (5.0 g, 20.6 mmol), triethylamine (5.22 g,
1.4 mmol), and Me NꢀHCl (1.3 g, 21.6 mmol) in CH Cl
3
2
2
1
(
30 mL). After completion of the addition, the resulting solu-
obtained as a yellow oil (1.02 g, 72%). H-NMR (400 MHz,
tion was allowed to stir at room temperature for 4 h. Then,
the reaction mixture was poured into water, followed by
CDCl
m, 4H), 6.94 (m, 2H), 3.70 (d, 4H), 1.72 (m, 2H), 1.43-1.28
(m, 48H), 0.88 (m, 12H). Elemental Anal. Calcd. for
C H Br N O ): C, 67.81; H, 8.32; N, 3.04. Found: C, 69.13;
3
) d (ppm): 7.92 (s, 2H), 7.24 (d, J 5 7.8 Hz, 2H), 7.20
(
extraction with CH Cl . The organic layer was dried using
2
2
anhydrous magnesium sulfate and filtered, and the solvent
was removed under reduced pressure. The product was
purified by silica gel column chromatography. The desired
(
5
2
76
2 2 2
H, 8.08; N, 3.22.
1
product 1 was obtained as a colorless oil (7.5 g, 91%). H-
2-(2-hexyldecyl)Thiophene (4)
NMR (500 MHz, CDCl ) d (ppm): 7.80 (d, J 5 8.2 Hz, 2H),
n-BuLi (2.85 mL, 7.1 mmol, 2.5 M solution in n-hexane) was
added into a solution of thiophene (0.6 g, 7.1 mmol) in THF
(20 mL) at 278 8C. The mixture was stirred at this tempera-
ture for 1 h and then 2-hexyldecyl bromide (2.0 g, 3.3
mmol) was added. After the addition was complete, the
3
7
.35 (d, J 5 8.2 Hz, 2H), 3.92 (d, 2H), 2.45 (s, 3H), 1.60 (m,
H), 1.31-1.13 (m, 24H), 0.88 (m, 6H). Elemental Anal. Calcd.
for (C H O S): C, 69.65; H, 10.17; S, 8.08. Found: C, 71.05;
1
2
3 40 3
H, 9.69; S, 7.97.
2
JOURNAL OF POLYMER SCIENCE, PART A: POLYMER CHEMISTRY 2017, 00, 000–000