2H), 7.88 (d, J = 8.5 Hz, 2H), 7.67 (dd, J = 8.5, 1.8 Hz, 2H),
7.49 (dd, J = 8.6, 1.8 Hz, 2H), 7.35 (d, J = 8.6 Hz, 2H), 1.51
(s, 18H), 1.48 (s, 18H). 13C NMR (151 MHz, CDCl3) δ 145.2,
143.5, 142.6, 141.0, 137.5, 133.1, 129.7, 125.0, 123.7, 123.1,
120.2, 119.4, 119.4, 116.3, 111.8, 109.4, 35.0, 34.9, 32.2, 32.0.
2H), 7.46 (d, J = 8.3 Hz, 2H), 7.42 (d, J = 8.2 Hz, 2H), 7.28
(d, J = 8.4 Hz, 2H), 2.87 – 2.79 (m, 8H), 1.81 – 1.71 (m, 8H),
1.47 – 1.32 (m, 24H), 0.92 (t, J = 6.7 Hz, 12H). 13C NMR
(151 MHz, CD2Cl2) δ 144.7, 142.7, 140.1, 138.0, 137.2, 137.2,
136.8, 135.1, 130.4, 129.9, 128.0, 127.5, 127.1, 124.0, 123.4,
120.0, 119.4, 119.3, 112.3, 110.0, 36.6, 36.5, 32.9, 32.7, 32.4,
32.4, 29.7, 29.6, 23.3, 23.3, 14.5, 14.5.. HRMS (ESI): m/z
calculated for C60H70N2+ [M]+ 818.5534, found 818.5537.
+
HRMS (ESI): m/z calculated for C46H50N2 [M]+ 630.3969,
found 630.3962.
2-(3,6-Dihexyl-9H-carbazol-9-yl)-5,11-
dihexylindolo[3,2,1-jk]carbazole
(HexICzCz).
The
5,5',11,11'-Tetra-bis(1,1-dimethylethyl)-2,2'-
compound was prepared according to GP1 starting from 2c
(1.47 g, 3.01 mmol), 4b (1.52 g, 4.53 mmol), K2CO3 (833 mg,
6.03 mmol) and CuSO4*5H2O (75 mg, 0.30 mmol).
biindolo[3,2,1-jk]carbazole (tBuICzICz). The compound
was prepared according to GP2 starting from 2a (1.08 g, 2.50
mmol), 3a (1.50 g, 3.13 mmol), Pd(PPh3)4 (146 mg, 0.13
mmol) and K2CO3 (869 mg, 6.29 mmol, in 3.2 ml H2O).
Purification
by
column
chromatography
(light
petroleum/CH2Cl2, 1% - 2%) gave HexICzCz (1.75 g, 2.35
mmol, 78%) as yellow oil that crystallized after several days.
1H NMR (600 MHz, CD2Cl2) δ 8.14 (s, 2H), 7.99 (s, 2H),
7.94 (s, 2H), 7.86 (d, J = 8.3 Hz, 2H), 7.44 (dd, J = 8.3, 1.5
Hz, 2H), 7.29 (d, J = 8.3 Hz, 2H), 7.23 (dd, J = 8.4, 1.5 Hz,
2H), 2.85 – 2.78 (m, 8H), 1.78 – 1.69 (m, 8H), 1.38 (d, J =
70.2 Hz, 24H), 0.94 – 0.88 (m, 12H). 13C NMR (151 MHz,
CD2Cl2) δ 143.7, 141.6, 138.1, 137.4, 134.8, 133.5, 130.2,
128.4, 127.1, 123.6, 123.6, 120.0, 119.9, 119.5, 112.4, 110.0,
36.6, 36.5, 33.0, 32.7, 32.4, 32.3, 29.7, 29.6, 23.3, 23.2, 14.5,
Purification
by
column
chromatography
(light
petroleum/CH2Cl2 5% - 25%) gave tBuICzICz (0.62 g, 0.88
mmol, 35%) as white solid. H NMR (600 MHz, CDCl3) δ
1
8.45 (s, 4H), 8.25 (s, 4H), 7.86 (d, J = 8.5 Hz, 4H), 7.64 (d, J
= 10.4 Hz, 4H), 1.50 (s, 36H). 13C NMR (151 MHz, CDCl3)
δ 144.8, 144.2, 139.8, 137.4, 130.1, 124.4, 120.3, 120.0, 119.0,
111.6, 35.1, 32.1. HRMS (ESI): m/z calculated for
C52H52N2+ [M]+ 704.4125, found 704.4128.
5,5',11,11'-Tetrahexyl-2,2'-biindolo[3,2,1-jk]carbazole
(HexICzICz). The compound was prepared according to
GP2 starting from 2c (1.22 g, 2.50 mmol), 3b (1.49 g, 2.78
mmol), Pd(PPh3)4 (147 mg, 0.13 mmol) and K2CO3 (866 mg,
6.27 mmol, in 3.2 ml H2O). Purification by column
chromatography (light petroleum/CH2Cl2 5% - 15%) gave
HexICzICz (0.89 g, 1.09 mmol, 44%) as off-white solid. 1H
NMR (600 MHz, CDCl3) δ 8.37 (s, 4H), 8.01 (s, 4H), 7.81 (d,
J = 8.2 Hz, 4H), 7.39 (d, J = 8.2 Hz, 4H), 2.83 (t, J = 7.7 Hz,
8H), 1.76 (p, J = 7.6 Hz, 8H), 1.46 – 1.32 (m, 24H), 0.91 (t, J
= 7.0 Hz, 12H). 13C NMR (151 MHz, CDCl3) δ 144.0, 139.7,
137.7, 136.4, 130.3, 127.3, 123.0, 120.3, 118.7, 111.9, 36.3,
32.3, 32.0, 29.2, 22.8, 14.3. HRMS (ESI): m/z calculated for
C60H68N2+ [M]+ 816.5377, found 816.5376.
+
14.5. HRMS (ESI): m/z calculated for C54H66N2 [M]+
742.5221, found 742.5220.
5,11-Bis(1,1-dimethylethyl)-2-(4-(3,6-bis(1,1-
dimethylethyl)-9H-carbazol-9-yl)phenyl)indolo[3,2,1-
jk]carbazole (tBuICzPCz). The compound was prepared
according to GP2 starting from 2a (1.08 g, 2.50 mmol), 6a
(1.50 g, 3.12 mmol), Pd(PPh3)4 (146 mg, 0.13 mmol) and
K2CO3 (871 mg, 6.30 mmol, in 3.2 ml H2O). Purification by
column chromatography (light petroleum/CH2Cl2, 5% - 8%)
gave tBuICzPCz (1.31 g, 1.85 mmol, 74%) as white solid.
1H NMR (600 MHz, CDCl3) δ 8.37 (s, 2H), 8.24 (d, J = 1.7
Hz, 2H), 8.18 (d, J = 1.5 Hz, 2H), 8.00 (d, J = 8.3 Hz, 2H),
7.85 (d, J = 8.5 Hz, 2H), 7.70 (d, J = 8.3 Hz, 2H), 7.65 (dd, J
= 8.5, 1.9 Hz, 2H), 7.52 (dd, J = 8.6, 1.8 Hz, 2H), 7.48 (d, J
= 8.6 Hz, 2H), 1.50 (s, 18H), 1.50 (s, 18H). 13C NMR (151
MHz, CDCl3) δ 145.0, 144.6, 142.9, 142.4, 139.5, 137.4,
136.7, 136.5, 129.9, 129.6, 127.1, 124.6, 123.8, 123.5, 120.0,
119.2, 119.1, 116.4, 111.7, 109.5, 35.1, 34.9, 32.2, 32.0.
3. Results and Discussion
3.1. Synthesis
The synthetic strategy towards the alkylation of the ICz
building block is depicted in scheme 1 (left side, a). The tert-
butyl substituted building block 2a was synthesized in one
step starting from the brominated ICz precursor 1 by Friedel
Crafts alkylation using 2-chloro-2-methylpropane and ZnCl2
as lewis acid in nitromethane. As substitution occurs
exclusively in the desired positions para to the central
nitrogen atom an excess of the alkylation reagent could be
used yielding 2a almost quantitatively. Introduction of the
hexyl chains was achieved in a similar approach employing
first a Friedel-Crafts acylation with hexanoyl chloride and
AlCl3 as lewis acid. Subsequently, the carbonyl groups were
reduced with LiAlH4 giving the hexyl building block 2c with
an excellent yield of 80% over both steps. Finally, the
halogenated precursors were converted to the corresponding
+
HRMS (ESI): m/z calculated for C52H54N2 [M]+ 706.4282,
found 706.4280.
2-(4-(3,6-Dihexyl-9H-carbazol-9-yl)phenyl)-5,11-
dihexylindolo[3,2,1-jk]carbazole (HexICzPCz). The
compound was prepared according to GP2 starting from 2c
(1.22 g, 2.50 mmol), 6b (1.41 g, 2.62 mmol), Pd(PPh3)4 (145
mg, 0.13 mmol) and K2CO3 (866 mg, 6.27 mmol, in 3.2 ml
H2O). Purification by column chromatography (light
petroleum/CH2Cl2 3% - 10%) gave HexICzPCz (1.08 g,
1
1.32 mmol, 53%) as off-white solid. H NMR (600 MHz,
CD2Cl2) δ 8.32 (s, 2H), 8.03 (s, 2H), 7.99 (d, J = 8.3 Hz, 2H),
7.96 (s, 2H), 7.81 (d, J = 8.2 Hz, 2H), 7.71 (d, J = 8.3 Hz,