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S. Ozgün et al. / Journal of Molecular Structure 1127 (2017) 31e42
T80 þ double beam UVeVisible spectrophotometer in 3.5 ml,
1.0 cm path length optical quartz cells with polytetrafluoroethylene
(PTFE) stoppers using dichloromethane as the solvent. In the
compound 5b was synthesized via the same procedure as 5a from
1.01 g (2.0 mmol) of 3,6-diiodo-9-hexylcarbazole (4b), 1.0 g
(6.0 mmol) of carbazole, 0.64 g (10.0 mmol) of Cu turnings and
2.37 g (17 mmol) of K2CO3. The crude product was purified via
column chromatography (silica gel 60, 70e230 mesh) with
dichloromethane/nꢀhexane (v/v [1/2]) as eluent. Yield: 0.68 g
thermodynamic experiments
a
PTCꢀ2 peltier temperature
controller unit was attached to the UVeVis spectrophotometer
with a 0.1 ꢁC uncertainty of temperature. IR spectra were taken on
a Perkin Elmer Spectrum Two FTꢀIR spectrometer using attenuated
total reflection (ATR) sampling. 1H and 13C NMR data were obtained
from an Agilent Technologies 400 MHz NMR spectrometer (in
CDCl3, TMS as the internal reference). Thermal analyses (TGA and
DSC) were carried out using a Setaram SETSYS Evolution TGAꢀDTA/
DSC instrument.
(59%) of a white powder. 1H NMR (400 MHz, CDCl3):
d
¼ 8.22 (d,
J ¼ 1.59 Hz, 2H, ArH), 8.16 (d, J ¼ 7.7 Hz, 4H, ArH), 7.68e7.66 (m, 4H,
ArH), 7.40e7.24 (m, 12H, ArH), 4.49 (t, J ¼ 7,4 Hz, 2H), 2.06 (quinted,
J ¼ 7.3 Hz, 2H), 1,60e1.34 (m, 6H), 0.94 (t, J ¼ 7.2, 3H). 13C NMR
(100 MHz, CDCl3):
d
¼ 141.9, 140.2, 129.3, 125.9, 125.8, 123.4, 123.1,
120.2, 119.8, 119.6, 110.1, 109.7, 43.7, 31.6, 29.1, 27.1, 22.6, 14.0. FTIR
(ATR) v (cmꢀ1): 3049, 2953, 2929, 2864, 1626, 1595, 1574, 1495,
1477, 1450, 1336, 1315, 1288, 1231, 807, 748, 724, 653, 641, 560.
UVeVis, [CH2Cl2, lmax (nm), (ε)]: 264 (5.76 ꢂ 104), 294 (5.10 ꢂ 104),
343 (1.32 ꢂ 104).
2.2. Materials
Carbazole and 9-ethylcarbazole were in 95e98 purity as
received and purified via recrystallization from proper solvents
prior to using. 1-Bromoheksane, dibromomethane, 1,3-
dibromopropane, 1,4-dibromobutane, 1,5-dibromopentane and
ethylene di(p-toluenesulfonate) were purchased from global sup-
pliers and used as received. The acceptors TCNE (Aldrich) was pu-
rified by sublimation and TNM was synthesized as described in the
literature [15], purified by freezeꢀthaw method. CH2Cl2 used in
spectroscopic measurements were of analytical grade and used
without further purification.
Synthesis of 1,n-di-[3,6-di-(9-carbazolyl)-9-carbazolyl]alkanes
(7a¡7e): The compounds 7a¡7e were synthesized by the similar
procedure as 5a from 1.0 mmol of 1,n-di(3,6-diiodocarbazole-9-yl)
alkane (n ¼ 1e5, compounds 6a¡6e), 1.0 g (6.0 mmol) of carbazole,
0.64 g (10.0 mmol) of Cu turnings and 2.37 g (17 mmol) of K2CO3.
The crude products were purified via column chromatography
(silica gel 60, 70e230 mesh) with dichloromethane/n-hexane (v/v
[1/2]) as eluent.
Di-[3,6-di-(9-carbazolyl)-9-carbazolyl]methane
(7a).
Yield
0.720 g (71%). 1H NMR (400 MHz, CDCl3):
d
¼ 8.32 (d, J ¼ 1.9 Hz, 4H,
2.3. Synthesis
ArH), 8.16 (d, J ¼ 7.8 Hz, 8H, ArH), 7.92 (d, J ¼ 8.6 Hz, 4H, ArH), 7.76
(dd, J ¼ 8.6, 2.4 Hz, 4H, ArH), 7.41e7.38 (m, 16H, ArH), 7.31e7.26 (m,
3,6-Diiodocarbazoles were achieved by a literature procedure
using KI and KIO3 in glacial acetic acid [16].
8H, ArH), 7.08 (s, 2H, CH2). 13C NMR (100 MHz, CDCl3):
d
¼ 141.6,
139.8,131.1,126.8,126.0,124.7,123.2,120.4,120.3,119.9,110.7,109.6,
57.8. FTIR (ATR) v (cmꢀ1): 3049, 2952, 2929, 1625, 1595, 1574, 1495,
1477, 1466, 1450, 1333, 1283, 1228, 1150, 1063, 1016, 917, 872, 801,
746, 722, 652, 640, 615, 558. UVeVis, [CH2Cl2, lmax (nm), (ε)]: 268
(9.36 ꢂ 104), 292 (7.92 ꢂ 104), 342 (2.28 ꢂ 104).
General procedure for the synthesis of 9-hexyl-3,6-diiodocarbazole
(4b) and 1,n-di(3,6-diiodocarbazole-9-yl)alkanes (6a¡6e): In
a
100 ml roundꢀbottom flask 4.19 (10.0 mmol) of 1,3-
g
diiodocarbazole (3) was dissolved in 50 ml of dimethyl sulfoxide
(DMSO) and 1,12 g (20.0 mmol) of KOH was added. The mixture was
stirred for 30 min at room temperature to generate carbazolide
anion. To this 5.0 mmol of the substrate molecule (1-bromohexane
for 4b, 1,n-dibromoalkane for 6a, 6cꢀ6e, and ethylene di(p-
toluenesulfonate) for 6b) was added and the temperature was
raised to 85e90 ꢁC. After stirring at this temperature for 12 h,
during which time a white precipitate evolved, the mixture was
cooled to room temperature, filtered, washed first with water and
then with ethanol to remove unreacted 3, and air dried. The com-
pounds 4b and 6a¡6e were obtained as white powder and used in
the next step without further treatment.
1,2-Di-[3,6-di-(9-carbazolyl)-9-carbazolyl]ethane (7b). Yield
0.654 g (64%). 1H NMR (400 MHz, CDCl3):
d
¼ 8.16e8.09 (m, 12H,
ArH), 7.92 (dd, J ¼ 8.6,1.9 Hz, 4H, ArH), 7.39e7.10 (m, 28H, ArH), 5.11
(s, 4H, CH2). 13C NMR (100 MHz, CDCl3):
d
¼ 141.5, 139.6, 130.0,
125.9, 125.8, 123.8, 123.1, 120.2, 119.7, 119.5, 109.4, 109.3, 41.6. FTIR
(ATR) v (cmꢀ1): 3049, 2952, 2925, 2866, 1625, 1595, 1573, 1495,
1477, 1450, 1334, 1313, 1287, 1229, 1157, 1117, 1019, 917, 876, 805,
745, 722, 684, 641, 615, 558. UVeVis, [CH2Cl2, lmax (nm), (ε)]: 272
(9.0 ꢂ 104), 294 (7.20 ꢂ 104), 342 (2.16 ꢂ 104).
1,3-Di-[3,6-di-(9-carbazolyl)-9-carbazolyl]propane (7c). Yield
0.78 g (75%). 1H NMR (400 MHz, CDCl3):
d
¼ 8.27 (d, J ¼ 1.9 Hz, 4H,
Synthesis of 9-ethyl-3,6-di-(9-carbazolyl)carbazole (5a): 1.25 g
(7.5 mmol) of carbazole (1), 1.27 g (20 mmol) of Cu turnings, 5.0 g
(36.2 mmol) of K2CO3 and 0.26 g (1.0 mmol) of 18-crown-6 in 20 ml
1,2-dichlorobenzene were heated to reflux. Over one hour period,
2.24 g (5.0 mmol) of 9-ethyl-3,6-diiodocarbazole (4a) was added
portion wise to the reaction mixture and further refluxed for 24 h.
The organic component was separated trough filtration while hot
and precipitated into 100 ml of methanol. The crude product was
further purified via column chromatography (silica gel 60, 70e230
mesh) with dichloromethane/n-hexane (v/v [1/1]) as eluent. Yield:
ArH), 8.15 (d, J ¼ 7.6 Hz, 8H, ArH), 7.69 (d,d J ¼ 8.6 and 1.9 Hz, 4H,
ArH), 7.60 (d, J ¼ 8.6 Hz, 4H, ArH), 7.38e7.23 (m, 22H, ArH), 4.72 (t,
J ¼ 7.4 Hz, 4H, CH2), 2.92e2.83 (m, 2H, CH2). 13C NMR (100 MHz,
CDCl3):
d
¼ 141.7, 139.9, 130.0, 126.3, 125.9, 123.7, 123.2, 120.3, 120.1,
119.8, 109.8, 109.6, 41.2, 28.3. FTIR (ATR) v (cmꢀ1): 3049, 3020, 1626,
1595, 1573, 1495, 1477, 1450, 1334, 1313, 1283, 1229, 805, 747, 722,
641, 616, 559. UVeVis, [CH2Cl2, lmax (nm), (ε)]: 264 (1.10 ꢂ 105), 294
(9.24 ꢂ 104), 342 (2.64 ꢂ 104).
1,4-Di-[3,6-di-(9-carbazolyl)-9-carbazolyl]butane (7d). Yield
0.72 g (69%). 1H NMR (400 MHz, CDCl3):
d
¼ 8.27 (s, 4H, ArH), 8.15
1.65 g (63%) of a white powder. 1H NMR (400 MHz, CDCl3):
d
¼ 8.23
(d, J ¼ 7.8 Hz, 8H, ArH), 7.70 (d, 1.2 Hz, 8H, ArH), 7.39e7.34 (m, 16H,
ArH), 7.30e7.24 (m, 8H, ArH), 4.61 (t, J ¼ 7.4 Hz, 4H, CH2), 2.37e2.32
(d, J ¼ 1.77 Hz, 2H, ArH), 8.16 (d, J ¼ 7.7 Hz, 4H, ArH), 7.7e7.6 (m, 4H,
ArH), 7.40e7.24 (m, 12H, ArH), 4.58 (q, J ¼ 7,2 Hz, 2H), 1.64 (t, J ¼ 7.2,
(m, 4H, CH2). 13C NMR (100 MHz, CDCl3):
d
¼ 141.8, 130.1, 129.8,
3H). 13C NMR (100 MHz, CDCl3)
d: 141.9; 139.7, 129.4, 126.0, 125.8,
126.2, 125.9, 123.6, 123.1, 120.3, 120.0, 119.7, 110.0, 109.6. FTIR (ATR)
v (cmꢀ1): 3047, 2924, 2853, 1625, 1594, 1573,1494, 1476,1449, 1334,
1312,1287,1230, 808, 745, 720, 642, 622, 563. UVeVis, [CH2Cl2, lmax
(nm), (ε)]: 270 (8.64 ꢂ 104), 294 (6.84 ꢂ 104), 343 (1.92 ꢂ 104).
1,5-Di-[3,6-di-(9-carbazolyl)-9-carbazolyl]pentane (7e). Yield
123.5, 123.1, 120.2, 119.9, 119.6, 109.9, 109.7, 38.2, 14.1. FTIR (ATR) v
(cmꢀ1): 3050, 2975, 1626, 1594, 1573, 1496, 1478, 1451, 1335, 1318,
1294, 1275, 1232, 816, 806, 749, 723, 684, 653, 641, 620, 560.
UVeVis, [CH2Cl2, lmax (nm), (ε)]: 264 (6.78 ꢂ 104), 294 (5.70 ꢂ 104),
342 (1.56 ꢂ 104).
0.81 g (76%). 1H NMR (400 MHz, CDCl3):
8.15 (d, J ¼ 7.6 Hz, 8H, ArH), 7.69e7.67 (m, 8H, ArH), 7.38e7.34 (m,
d
¼ 8.26e8.24 (m, 4H, ArH),
Synthesis of 9-hexyl-3,6-di-(9-carbazolyl)carbazole (5b): The