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A. Brzeczek et al. / Dyes and Pigments 113 (2015) 640e648
2H), 1.88e1.81 (m, 2H), 1.4 (s, 12H), 1.36e1.17 (m, 10H), 0.85 (t,
1H NMR (400 MHz, CDCl3)
d
8.45 (d, J ¼ 1.6 Hz, 3H), 8.39 (d,
J ¼ 6.9 Hz, 3H). 13C NMR (101 MHz, CDCl3)
d
145.75, 143.02, 140.04,
J ¼ 1.6 Hz, 3H), 8.08 (s, 3H), 7.84 (dd, J ¼ 8.8, 1.6 Hz, 3H), 7.75 (dd,
J ¼ 8.8, 2.0 Hz, 3H), 7.71 (dd, J ¼ 7.8, 1.6 Hz, 3H), 7.49 (d, J ¼ 8.4 Hz,
3H), 7.40 (d, J ¼ 2.7 Hz, 3H), 7.35 (dd, J ¼ 3.6, 1.1 Hz, 3H), 7.24e7.21
(m, 3H), 7.09 (dd, J ¼ 5.1, 3.6 Hz, 3H), 4.33 (t, J ¼ 7.2 Hz, 6H), 1.88 (m,
6H), 1.42e1.00 (m, 30H), 0.92e0.77 (m, 9H). 13C NMR (101 MHz,
132.37, 127.96, 127.89, 126.04, 124.12, 123.60, 123.53, 122.54, 121.90,
118.03, 109.00, 108.28, 83.59, 43.20, 31.76, 29.33, 29.12, 28.94, 27.23,
24.93, 22.57, 14.04.
2.1.10. General procedure for the preparation TCB (9a) and MTCB
(9b)
1,3,5-tribromobenzene (0.06 g, 0.2 mmol) or 1,3,5-tribromo-2-
methoxybenzene (0.07 g, 0.2 mmol), and 9-octyl-3-(4,4,5,5-
CDCl3) d 145.77, 142.56, 140.48, 132.72, 127.96, 125.83, 125.63,
125.53, 124.44, 123.61, 123.45, 123.37, 122.02, 120.31, 119.18, 118.66,
117.98, 109.14, 108.62, 43.37, 31.81, 29.40, 29.19, 29.07, 27.34, 22.61,
14.07.
tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole
3
(0.40 g,
1 mmol) were dissolved in solvent mixture of THF (20 ml) and H2O
(2 ml). The reaction mixture was purged with nitrogen for 5 min
and degassed. Powdered anhydrous potassium carbonate (0.14 g,
1 mmol) and bis-(triphenylphosphine) palladium (II) dichloride
(0.008 g, 0.06 eq.) were added. The reaction mixture was refluxed
for 15 h under nitrogen, after which the mixture was cooled, diluted
with water (50 ml), extracted with CH2Cl2 (4 ꢁ 20 ml) and dried
over anhydrous Na2SO4. The solvent was removed under reduced
pressure and the residue was purified by column chromatography
(n-hexane: ethyl acetate 25:1, v/v and n-hexane: toluene 4:1, v/v
solvent mixtures for TCB and n-hexane: ethyl acetate 25:1, v/v and
n-hexane: toluene 3:1, v/v) for MTCB were used as eluents.
2.2. Electrochemical measurement
Electrosynthesis and studies on polymer films were performed
on CH Instrument Electrochemical Analyzer model 620. Measure-
ment was carried out in acetonitrile (CH3CN; Sigma Aldrich ꢃ99.8%)
containing 0.1
M
tetrabutylammonium hexafluorophospate
(Bu4NPF6; SigmaeAldrich 98%) as a supporting electrolyte. Pt wire
served as working electrode, Pt spiral as a counter electrode. An Ag
pseudo-reference electrode was used and its exact potential was
calibrated versus ferrocene/ferrocenium redox couple.
2.3. Spectral measurement
2.1.11. 1,3,5-tris(9-octyl-9H-carbazol-3-yl)benzene TCB (9a);
UV-Vis measurements were carried out on 8453 Hewlett Pack-
ard spectrophotometer, while fluorescence measurements were
performed on F-2500 Hitachi fluorescence spectrometer.
0.076 g, yield 42%
1H NMR (400 MHz, CDCl3)
d
8.51 (d, J ¼ 1.6 Hz, 3H), 8.19 (d,
J ¼ 8.0 Hz, 3H), 8.02 (s, 3H), 7.92 (dd, J ¼ 8.5, 1.6 Hz, 3H), 7.53 (d,
J ¼ 8.5 Hz, 3H), 7.51e7.43 (m, 6H), 7.27e7.24 (m, 3H), (t, J ¼ 7.2 Hz,
2.4. DFT calculations
6H), 1.95e1.91 (m, 6H), 1.26e1.46 (m, 30H), 0.89e0.83 (m, 9H). 13
C
NMR (101 MHz, CDCl3)
125.45, 124.79, 123.43, 123.06, 120.53, 119.18, 118.90, 43.27, 31.82,
29.41, 29.19, 29.05, 27.36, 22.61, 14.07. MALDI-TOF-MS m/z calcd for
d
143.25, 140.96, 140.09, 132.66, 125.77,
For computational studies, model compounds with N-alkyl
chains reduced to methyl groups were investigated. Quantum
chemical calculations were performed with Gaussian 09 revision
B.01 software [20]. All calculation were carried out using density
functional theory with B3LYP [21,22] hybrid functional and 6-31G(d)
basis set. The ground state geometries were optimized with no
symmetry constrains to a local minimum, which was followed by
frequency calculations. In all cases no imaginary frequencies were
found. Optical properties of molecules were simulated with time-
dependant DFT [23] method with the same functional and basis
set as in DFT calculation, simulating first 50 singlet excited states.
Geometry for TDDFT calculations was taken from the DFT calcula-
tion. In order to simulate the influence of solution, all calculations in
this work (both DFT and TDDFT) were conducted with polarizable
continuum model (PCM) [24], using acetonitrile or dichloromethane
as solvent (depending on solvent used to obtain optical spectra), as
implemented in Gaussian 09 software. Input files and molecular
orbital plots were prepared with Gabedit 2.4.7 software [25].
C
66H75N3, 910.32; found, 910.50.
2.1.12. 2-methoxy-1,3,5-tris(9-octyl-9H-carbazol-3-yl)benzene
MTCB (9b); 0.092 g, 49%
1H NMR (600 MHz, CDCl3)
d
8.48 (d, J ¼ 1.0 Hz, 2H), 8.43 (d,
J ¼ 1.0 Hz, 1H), 8.17 (dd, J ¼ 7.8, 1.0 Hz, 2H), 8.14 (d, J ¼ 7.8 Hz, 1H),
7.88 (dd, J ¼ 8.4,1.2 Hz, 2H), 7.85 (dd, J ¼ 8.4,1.2 Hz,1H), 7.83 (s, 2H),
7.51 (d, J ¼ 8.4 Hz, 2H), 7.50e7.39 (m, 7H), 7.26e7.20 (m, 3H), 4.35 (t,
J ¼ 7.3 Hz, 4H), 4.31 (t, J ¼ 7.3 Hz, 2H), 3.26 (s, 3H), 1.95e1.87 (m,
6H), 1.52e1.20 (m, 30H), 0.88e0.83 (m, 9H). 13C NMR (151 MHz,
CDCl3)
d 154.14, 140.89, 140.80, 139.88, 139.76, 138.04, 136.73,
131.88, 129.77, 129.00, 127.39, 125.70, 125.60, 125.13, 123.37, 123.04,
123.01, 122.89, 121.22, 120.49, 120.47, 118.82, 118.80, 108.88, 108.76,
108.73, 108.31, 60.45, 43.25, 43.22, 31.81, 31.79, 29.70, 29.41, 29.39,
29.20, 29.17, 29.06, 29.02, 27.38, 27.34, 22.61, 22.60, 14.07. MALDI-
TOF-MS m/z calcd for C67H77N3O, 940.35; found, 940.60.
2.5. Spectroelectrochemical experiments
2.1.13. 1,3,5-tris(9-octyl-6-(thiophen-2-yl)-9H-carbazol-3-yl)
benzene TTCB (9c)
Spectroelectrochemical studies were performed with in situ
simultaneous EPR-UV-Vis-NIR spectroelectrochemical measure-
ments. In this kind of setup, one can record both EPR and optical
spectra of materials in one experiment as a function of applied
potential. JEOL JES-FA200 equipped with JEOL optical cavity was
used as a EPR spectrometer, while the UV-Vis-NIR spectra were
recorded with Ocean Optics QE65000 and NirQuest512 spectrom-
eters coupled with DH-BAL200 light source. Light was directed to
the samples and collected after absorption in the optical resonator
by the means of optical fibres. Potential was applied with AUTOLAB
PGSTAT100N potentiostat. For spectroelectrochemical studies, a
thin layer of polymer was deposited on glass electrode covered
with Indium Tin Oxide (ITO), using cyclic voltammetry technique.
Polymers were deposited from saturated solution of monomers in
1,3,5-Tribromobenzene (0.06 g, 0.2 mmol) and 9-octyl-3-
(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6-(thiophen-2-yl)-
9H-carbazole 7 (0.44 g, 0.9 mmol) were dissolved in solvent
mixture of toluene (7.5 ml), H2O (2.4 ml) and ethanol (0.5 ml). The
reaction mixture was purged with nitrogen for 5 min and degassed.
Powdered sodium carbonate (0.42 g, 4 mmol) and tetrakis(-
triphenylphosphine)palladium (0) (0.023 g, 0.1 eq.) were added.
The reaction mixture was refluxed for 15 h under nitrogen, after
which the mixture was cooled, diluted with water (50 ml),
extracted with CH2Cl2 (4 ꢁ 20 ml) and dried over anhydrous
Na2SO4. The residue was purified by column chromatography (n-
hexane: toluene 3:1, v/v) to give white product of TTCB (0.134 g,
58%).