J.H. Yun et al.
Dyes and Pigments xxx (xxxx) xxx
4.2.4. 9,9’-(20,50-Dimethyl-[1,1’:40,100-terphenyl]-3,300-diyl)bis(9H-
carbazole) (m-CzDMT)
2,2’-(2,5-Dimethyl-1,4-phenylene)bis(4,4,5,5-tetramethyl-1,3,2-
dioxaborolane) (0.7 g, 1.95 mmol) and 9-(3-bromophenyl)-9H-carba-
zole (1.39 g, 4.30 mmol) were dissolved in THF (20 ml). A 10 ml aqueous
solution of potassium carbonate (0.81 g, 5.86 mmol) was added to the
solution. Tetrakis(triphenylphosphine) palladium (0) (0.07 g,
0.06 mmol) was added and the solution was refluxed overnight. The
mixture was extracted with MC and purified by column chromatog-
raphy. A solid was recrystallized in a toluene/ethanol mixed solvent and
then vacuum sublimed. A white powder was obtained (0.88 g, yield
76.5%). 1H NMR (500 MHz, CDCl3):δ 8.149 (d, 4H, J ¼ 8.0 Hz), 7.655 (t,
2H, J ¼ 7.75 Hz), 7.597–7.551 (m, 4H), 7.493–7.463 (m, 6H), 7.416 (t,
4H, J ¼ 8.0 Hz), 7.304–7.265 (m, 6H), 2.392 (s, 6H). 13C NMR
(125 MHz, CDCl3):δ 143.61, 141.05, 140.40, 137.72, 132.98, 132.20,
129.83, 128.48, 127.97, 126.16, 125.67, 123.60, 120.53, 120.17,
110.01, 20.31. GC/MS (m/z): found, 589.2715 ([FAB]þ); Calcd. for
Fig. 8. Electroluminescence (EL) spectra of blue PhOLEDs of FIrpic emitter at
15% doping concentration. (For interpretation of the references to color in this
figure legend, the reader is referred to the Web version of this article.)
C44H32N2, 588.7383.
4.2.5. 9,9’-(20,50-Dimethyl-[1,1’:40,100-terphenyl]-4,400-diyl)bis(9H-
carbazole) (p-CzDMT)
4.2. Synthesis
9,9’-(20,50-Dimethyl-[1,1’:40,100-terphenyl]-4,400-diyl)bis(9H-carba-
zole) was synthesized according to the synthetic method of 9,9’-(20,50-
dimethyl-[1,1’:40,100-terphenyl]-3,300-diyl)bis(9H-carbazole) except for
the reagent. 9-(4-Bromophenyl)-9H-carbazole (0.99 g, 3.07 mmol) was
used instead of 9-(3-bromophenyl)-9H-carbazole (0.46 g, yield 56.1%).
1H NMR (500 MHz, CDCl3):δ 8.180 (d, 4H, J ¼ 8.0 Hz), 7.672–7.632 (m,
8H), 7.536 (d, 4H, J ¼ 8.5 Hz), 7.457 (t, 4H, J ¼ 7.5 Hz), 7.344–7.305
(m, 6H), 2.456 (s, 6H). 13C NMR (125 MHz, CDCl3):δ 141.09, 140.92,
140.51, 136.65, 133.10, 132.30, 130.88, 126.89, 126.17, 123.64,
120.56, 120.19, 110.08, 20.30. GC/MS (m/z): found, 589.2489
([FAB]þ); Calcd. for C44H32N2, 588.7383.
4.2.1. 2,2’-(2,5-Dimethyl-1,4-phenylene)bis(4,4,5,5-tetramethyl-1,3,2-
dioxaborolane)
2,5-Dibromo-p-xylene (6.0 g, 22.7 mmol), bis(pinacolato) diboron
(18.0 g, 68.2 mmol), potassium acetate (13.4 g, 136 mmol) and Pd(dppf)
Cl2 (1.0 g, 0.68 mmol) were dissolved in DMF (100 ml) and the mixture
was stirred at 85 �C for 48 h. After the reaction, the mixture was
extracted with MC and dehydrated with magnesium sulfate. A crude
product was purified by column chromatography and white powder was
obtained (6.37 g, yield 78.3%). 1H NMR (500 MHz, DMSO‑d6):δ 7.535
(s, 2H), 2.480 (s, 6H), 1.338 (s, 24H). LC/MS (m/z): found, 358.99 ([M þ
H]þ); Calcd. for C20H32B2O4, 358.09.
4.2.6. 9,9’-(20,50-Dimethyl-[1,1’:40,100-terphenyl]-3,300-diyl)bis(9H-
carbazole-3-carbonitrile) (m-CzCNDMT)
4.2.2. 9-(3-Bromophenyl)-9H-carbazole-3-carbonitrile
The synthetic method of 9-(3-bromophenyl)-9H-carbazole-3-car-
bonitrile was provided in our previous work [42].
9,9’-(20,50-Dimethyl-[1,1’:40,100-terphenyl]-3,300-diyl)bis(9H-carba-
zole-3-carbonitrile) was synthesized according to the synthetic method
of
9,9’-(20,50-dimethyl-[1,1’:40,100-terphenyl]-3,300-diyl)bis(9H-carba-
4.2.3. 9-(4-Bromophenyl)-9H-carbazole-3-carbonitrile
zole).
9-(3-Bromophenyl)-9H-carbazole-3-carbonitrile
(1.49 g,
9H-carbazole-3-carbonitrile (1.0 g, 5.20 mmol), 1,4-dibromoben-
zene (3.68 g, 15.6 mmol), potassium carbonate (2.16 g, 15.6 mmol),
1,10-phenanthroline (0.47 g, 2.60 mmol) and copper(I) iodide (0.50 g,
2.60 mmol) were dissolved in DMF (30 ml) and refluxed in a pressure
tube. After 2 h, the reaction mixture was filtered through celite and the
organic solvent was removed by vacuum evaporation. The product was
obtained as a powder after purification using column chromatography
(1.14 g, yield 63.0%). 1H NMR (500 MHz, DMSO‑d6):δ 8.864 (s, 1H),
8.377 (d, 1H, J ¼ 8.0 Hz), 7.890 (d, 2H, J ¼ 9.0 Hz), 7.810 (d, 1H,
J ¼ 8.5 Hz), 7.631 (d, 2H, J ¼ 8.5 Hz), 7.540 (t, 1H, J ¼ 7.75 Hz), 7.494
(d, 1H, J ¼ 8.0 Hz), 7.405 (t, 2H, J ¼ 9.0 Hz). LC/MS (m/z): found,
348.22 ([M þ H]þ); Calcd. for C19H11BrN2, 347.21.
4.30 mmol) was used as reagent instead of 9-(3-bromophenyl)-9H-
carbazole. The product was recrystallized with MC/ethanol and purified
by train vacuum sublimation (0.83 g, yield 66.4%). 1H NMR (500 MHz,
CDCl3):δ 8.462 (s, 2H), 8.169 (d, 2H, J ¼ 8.0 Hz), 7.706 (t, 2H,
J ¼ 8.0 Hz), 7.661 (d, 2H, J ¼ 8.5 Hz), 7.550–7.465 (m, 12H), 7.386 (t,
2H, J ¼ 7.25 Hz), 7.266 (s, 2H), 2.389 (s, 6H). 13C NMR (125 MHz,
CDCl3):δ 143.90, 142.77, 141.83, 140.21, 136.55, 133.02, 132.21,
130.22, 129.45, 127.95, 127.66, 125.76, 125.54, 123.79, 122.47,
121.55, 120.94, 120.57, 103.00, 20.28. GC/MS (m/z): found, 639.3158
([FAB]þ); Calcd. for C46H30N4, 638.7572.
Table 2
Device performances of m-CzDMT, p-CzDMT, m-CzCNDMT and p-CzCNDMT.
Host
Dopant
Von (V)a
ηmax (%)b
η1000 (%)c
ηp (lm/W)d
ηp,1000 (lm/W)e
Color coordinate
m-CzDMT
Firpic
7.0
6.7
5.7
5.3
18.2
16.9
17.3
17.7
16.3
15.8
16.0
15.8
20.6
19.6
29.6
29.4
15.0
15.4
18.5
19.5
(0.16, 0.34)
(0.15, 0.35)
(0.16, 0.35)
(0.15, 0.35)
p-CzDMT
m-CzCNDMT
p-CzCNDMT
a
Von is turn on voltage at 1cdm-2
b
c
ηmax is maximum external quantum efficiency.
η1000 is quantum efficiency measured at 1000cdm-2
ηp is maximum power efficiency.
d
e
ηp,1000 is power efficiency measured at 1000cdm-2
6