128
E. Ripaud et al. / Dyes and Pigments 95 (2012) 126e133
ꢀ
6
through a shadow mask, at a pressure of about 10 mbar. The
106.3; 46.3; 40.1; 30.5; 28.7; 23.8; 23.2; 14.1; 10.7. MS (MALDI-TOF,
Mþ ): calcd 650.12, found 682.10.
2
ꢂ
mask geometry defined a device’s area of 0.28 cm . Each ITO
coated-glass substrate supported two individual devices and for
each experiment a minimum of 4 devices (8 cells) was fabricated.
After preparation, the devices were stored and characterized in an
argon glovebox (200B, MBraun). The JeV curves of the devices were
recorded in the dark and under illumination using a Keithley 236
source-measure unit and a homemade acquisition program. The
light source was an AM 1.5 Solar Constant 575 PV simulator
2,5-Bis(2-ethyl-hexyl)-3,6-bis(5-(benzofuran-2-yl)furan-2-yl)
pyrrolo[3,4-c]pyrrole-1,4-dione (BFF)
In a Schlenk under inert atmosphere, to a solution of 5 (0.2 g,
0.307 mmol) in 20 mL of toluene degassed with argon are added
successively 2.2 eq of 2-trimethylstannylbenzo[b]thiophene and
ꢁ
0.2 eq of Pd(PPh
3
)
4
. The mixture is heated 15 h at 120 C under inert
(
Steuernagel Lichttecknik, equipped with a metal halogenide
atmosphere. After removal of toluene and dissolution in CH
target compound is precipitated with hexane to give 0.267 (75%) of
2 2
Cl the
lamp). The light intensity was measured by a broad-band power
meter (13PEM001, Melles Griot). The devices were illuminated
through the ITO electrode side. The efficiency values reported here
are not corrected, neither for the possible solar simulator spectral
mismatch nor for the reflection/absorbance of the glass/ITO/Bay-
tron coated electrodes.
1
a
blue-violet product.
3
H NMR (CDCl , ppm): 8.5 (d, 2H,
3J ¼ 3.8 Hz); 7.6 (d, 2H, 3J ¼ 7.5 Hz); 7.5 (d, 2H, 3J ¼ 7.5 Hz); 7.3 (m,
4H); 7.06 (d, 2H, 3J ¼ 4 Hz); 7.05 (s. 2H); 4.15 (d. 4H, 3J ¼ 7.6 Hz);
13
1.5e1.6 (m, 2H); 1.2e1.4 (m, 16H); 1.0e0.8 (m, 12H). C NMR
(CDCl
3
, ppm): 161.0; 155.1; 148.3; 146.6; 144.7; 132.7; 128.3; 125.5;
1
2
23.58; 122.4; 121.4; 111.3; 111.3; 107.6; 103.8; 46.7; 39.6; 30.3;
8.5; 23.5; 23.2; 14.1; 10.5. HRMS (Mþ ): calcd 724.3507, found
ꢂ
2.3. Synthesis
724.3497.
Compounds 2, 6 and BFT were synthesized as reported in the
literature [21].
2,5-Bis(2-ethyl-hexyl)-3,6-bis(5-(benzothiophen-2-yl)furan-2-yl)
pyrrolo[3,4-c]pyrrole-1,4-dione (BTF)
In a Schlenk under inert atmosphere, to a solution of 5 (0.2 g,
0.307 mmol) in 20 mL of toluene degassed with argon are added
3,6-Difuran-2-yl-2,5-dihydro-pyrrolo[3,4-c]pyrrole-1,4-dione (1)
Under inert atmosphere, 4.5 8.26 g of sodium [0.36 mol] and
successively 2.2 eq of 2-trimethylstannylbenzo[b]thiophene and
ꢁ
a spatula tip of FeCl
3
are added in 2-methylbutan-2-ol (90 mL). The
0.2 eq of Pd(PPh
3
)
4
. The mixture is heated 15 h at 120 C under inert
ꢁ
mixture is heated at 130 C for 1 h. Then, 0.16 furan-2-carbonitrile
atmosphere. After removal of toluene and dissolution in CH
2 2
Cl the
(
14.9 g, 0.16 mol) and 1 eq of di-tertio-amylsuccinate, (24.7 g) are
target compound is precipitated with hexane to give 0. 235 g (47%)
of a blue-violet product. H NMR (CDCl , ppm): 8.48 (d, 2H,
3
1
introduced with an automated syringe (3 hours-10 mL/h). The
mixture is stirred 3 h at 130 C. the compound is precipitated by
adding an ice/methanol 3/1 (200 mL) mixture, filtered and washed
with methanol to give 10.9 g (51%) of 1. H NMR (DMSO-d
ꢁ
3J ¼ 3.8 Hz); 7.8 (m, 4H); 7.56 (s, 2H); 7.35 (m, 4H); 6.90 (d, 2H,
3J ¼ 3.8 Hz); 4.12 (d, 4H, 3J ¼ 7.6 Hz); 1.5e1.6 (m, 2H); 1.2e1.4 (m,
1
13
6
, ppm):
16H); 0.8e1.0 (m, 12H). C NMR (CDCl
3
, ppm): 161.2; 152.0; 144.4;
1
3
1
1.13 (s, 2H); 8.02 (sel, 2H); 7.65 (sel, 2H); 6.82 (sel, 2H). C NMR
140.0; 132.8; 131.7; 131.0; 128.9; 125.4; 125.1; 124.1; 122.9; 122.4;
121.0; 110.9; 46.8; 39.5; 30.4; 28.6; 23.5; 23.3; 14.1; 10.6. HRMS
(
DMSO-d
6
, ppm): 161.6; 146.5; 144.1; 131.8; 116.3; 113.5; 107.9. IR
ꢀ
1
ꢂ
ꢂ
(
cm ): 1645 (C]O); 3112 eNeH; MS (MALDI-TOF, Mþ ): calcd
(Mþ ): calcd 756.3055, found 756.3029.
:
268.05, found: 268.50.
2,5-Bis(2-ethyl-hexyl)-3,6-bis(5-(benzothiophen-2-yl)thiophen-
2
,5-Bis-(2-ethyl-hexyl)-3,6-difuran-2-ylpyrrolo[3,4-c]pyrrole-1,4-
dione (3)
Under inert atmosphere, 3,6-difuran-2-yl-2,5-dihydro-pyrrolo
3,4-c] pyrrole-1,4-dione 1 (10.8 g, 0.04 mol) 5 eq of 1-bromo-2-
ethylhexane and 4 eq of K CO are suspended in 25 mL of dry
2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione (BTT)
In a Schlenk under inert atmosphere, to a degassed toluene
solution of 6 (0.2 g, 0.29 mmol) are added 2.2 eq of 2-
[
trimethylstannylbenzo[b]thiophene and 0.2 eq of Pd(PPh
3
)
4
were.
ꢁ
2
3
The mixture is heated 15 h at 120 C. After evaporation of toluene
and dissolution in methylenechloride the product is precipitated
ꢁ
DMF. The mixture is heated at 130 C and the reaction is monitored
by TLC. After cooling to rt, 400 mL of dichloromethane are added.
The organic phase is washed with water and dried over MgSO
with hexane. Chromatography on neutral alumina (DCM/Hex: 2/1)
1
4
.
gave 48% of the target compound. H NMR (CDCl
3
, ppm): 8.96 (d,
After removal of the solvent, the residue is chromatographed on
2H, 3J ¼ 4 Hz); 7.79 (m, 4H); 7.55 (s, 2H); 7.43 (d, 2H, 3J ¼ 4 Hz); 7.36
1
silica gel (DCM/PE: 2/1) to give 13 g (66%) of 3. H NMR (CDCl
3
,
(m, 4H); 4.07 (dd, 4H, 3J ¼ 3.3 Hz, 3J ¼ 7.7 Hz); 1.50e1.60 (m, 2H);
13
ppm): 8.33 (d, 2H, 3J ¼ 3.6 Hz); 7.61 (d, 2H, 3J ¼ 1.8 Hz); 6.69 (dd,
3
1.20e1.40 (m, 16H); 0.80e1.0 (m, 12H); C NMR (CDCl , ppm):
2
H, 3J ¼ 1.8 Hz, 3J ¼ 3.6 Hz); 4.06 (m, 4H); 1.5e1.6 (m, 2H); 1.2e1.4
161.6; 150.8; 142.6; 140.1; 135.8; 134.4; 129.2; 125.3; 125.0; 123.9;
122.2; 121.4; 121.4; 114.7; 108.7; 46.1; 31.9; 28.6; 23.7; 23.1; 22.7;
ꢀ1
(
m, 16H); 0.8e1.0 (m, 12H); IR (cm ); 1659 (C]O);
ꢂ
ꢂ
2
4
856e2925e2957 (alkyl chains); 3112 (NeH); HRMS (Mþ ): calcd
14.1; 10.6; HRMS (Mþ ): calcd 811.2491, found 811.2492.
92.2983, found 492.2978.
2,5-Diethylhexyl-3,6-bis(5-(benzofuran-2-yl)thiophen-2-yl)-
2,5-Bis-(2-ethyl-hexyl)-3,6-di(2-bromofurane)-5-ylpyrrolo[3,4-c]
pyrrolo[3,4-c]pyrrole-1,4-dithione (BFT-SS)
pyrrole-1,4-dione (5)
In the dark, at 0 C, 2.2 eq of NBS are added to 2,5-bis-(2-ethyl-
hexyl)-3,6-difuran ylpyrrolo-2-[3,4-c] pyrrole-1,4-dione 3 (12.6 g,
A mixture of BFT (100 mg, 0.13 mmol) and Lawesson’s reagent
(220 mg, 0.53 mmol), in 30 mL of anhydrous toluene is refluxed
overnight under argon. After concentration, the residue is choma-
tographed on silica gel (eluent dichloromethane/petroleum ether:
2/1) to give to a black solid, which is recrystallized from ethanol
ꢁ
2
5.6 mmol) in 100 mL of chloroform. The mixture is stirred under
inert atmosphere at rt 15 h. The reaction mixture is washed with
and
ꢁ
1
water 3 ꢃ 300 mL, the organic phase is dried over MgSO
4
(50 mg, yield ¼ 50%). M.p. 201e202 C. H NMR (300 MHz, CDCl
3
):
filtered. After evaporation of the solvent, the residue is precipitated
8.96 (d, 2H, J ¼ 4.0 Hz); 7.62e7.51 (m, 6H); 7.37e7.24 (m, 4H), 7.09
(s, 2H), 4.59e4.57 (m, 4H), 1.86e1.82 (m, 2H), 1.25e1.19 (m, 16H),
1
with hexane to give 9 g (54% yield) of a violet powder. H NMR
13
(
CDCl
3
, ppm): 8.30 (d, 2H, 3J ¼ 3.6 Hz); 6.62 (d, 2H, 3J ¼ 3.6 Hz);
3
0.82e0.77 (m, 12H). C NMR (300 MHz, CDCl ): 176.7, 155.0, 149.9,
3
.99 (m, 4H); 1.5e1.6 (m, 2H); 1.2e1.4 (m, 16H); 0.8e1.0 (m, 12H).
143.4, 139.0, 135.3, 128.8, 126.9, 125.7, 125.4, 124.5, 123.5, 121.2,
111.3, 103.8, 48.5, 38.6, 30.2, 28.4, 23.6, 22.9, 13.9, 10.7. MS MALDI:
1
3
C NMR (CDCl , ppm): 160.9; 146.2; 132.8; 126.3; 122.2; 115.5;
3