M. Lepeltier et al. / Organic Electronics 37 (2016) 24e34
27
6.31 (m, 1H), 5.68 (m, 1H), 5.38 (m, 1H), 1.97 (s, 3H). MS (ESI) Calcd
for C46H32Cl2F4Ir2N4 1172.1199; Found 1172.1204.
2.2.5. [Ir(C^N)2(N^N)](PF6)
To a solution of the dimer Ir(C^N)2Cl2Ir(C^N)2 (0.128 mmol)
(Ir(dfppy)2Cl2Ir(dfppy)2, Ir(tpy)2Cl2Ir(tpy)2 or Ir(dfppy)(tpy)Cl2Ir(dfp-
py)(tpy)) in 1,2-dichloroethane (20 mL) was added the N^N ligand
(0.32 mmol) (2,20-bipyridine or 1,10-phenanthroline). The reaction
mixture was refluxed for 2 h. Then, a saturated solution of sodium
hexafluorophosphate in methanol (5 mL) was added. The reaction
mixture was stirred at room temperature for 30 min. Then the
solvent was evaporated and dichloromethane (50 mL) was added.
The solution was filtered, the solvent was reduced and the product
was precipitated by addition of diethyl ether (50 mL). The product
was then filtered and purified by flash chromatography on silica gel
using a gradient of dichloromethane and methanol from (100:0) to
(90:10) as eluent. The product was isolated as a yellow powder.
Fig. 2. Structures of the two complexes investigated in this study.
2.2.2.1. Ir(dfppy)2(acac). (0.24 g, 18%): 1H NMR (300 MHz, CDCl3,
ppm): 8.45 (d, 3J ¼ 5.4 Hz, 2H), 8.26 (d, 3J ¼ 8.4 Hz, 2H), 7.81 (dt,
3J ¼ 7.8 Hz, 4J ¼ 1.2 Hz, 2H), 7.20 (m, 2H), 6.34 (m, 2H), 5.67 (dd,
3J ¼ 9.0 Hz, 4J ¼ 2.4 Hz, 2H), 5.27 (s, 1H), 1.83 (s, 6H). MS (ESI) Calcd
for C27H19F4IrN2O2 672.1012; Found 672.1046.
2.2.5.1. [Ir(dfppy)(tpy)(bpy)](PF6). (0.18 g, 82%), 1H NMR (300 MHz,
CDCl3, ppm): 9.53 (d, 3J ¼ 7.8 Hz, 2H), 8.29 (m, 3H), 7.83 (m, 5H),
7.60 (d, 3J ¼ 8.1 Hz, 1H), 7.47 (m, 3H), 7.39 (d, 3J ¼ 5.4 Hz, 1H), 7.06 (t,
3J ¼ 6.0 Hz, 1H), 6.98 (td, 3J ¼ 7.2 Hz, 4J ¼ 0.9 Hz, 1H), 6.90 (dd,
3J ¼ 8.1 Hz, 4J ¼ 6.9 Hz, 1H), 6.52 (m, 1H), 6.01 (s, 1H), 5.76 (dd,
3J ¼ 8.7 Hz, 4J ¼ 2.4 Hz, 1H), 2.16 (s, 3H). MS (ESI) Calcd for
[C33H24F2IrN4]þ 707.1600 Found 707.1595. Anal. calcd for
2.2.2.2. Ir(dfppy)(tpy)(acac). (0.414 g, 31%): 1H NMR (300 MHz,
CDCl3, ppm): 8.53 (d, 4J ¼ 5.1 Hz, 1H), 8.41 (dd, 3J ¼ 6.0 Hz,
4J ¼ 1.2 Hz, 1H), 8.25 (dd, 3J ¼ 8.7 Hz, 4J ¼ 2.7 Hz, 1H), 7.78 (m, 3H),
7.47 (d, 3J ¼ 7.5 Hz,1H), 7.15 (m, 2H), 6.69 (d, 3J ¼ 7.8 Hz,1H), 6.29 (d,
3J ¼ 7.8 Hz, 1H), 6.01 (s, 1H), 5.72 (dd, 3J ¼ 8.7 Hz, 4J ¼ 2.7 Hz, 1H),
5.23 (s, 1H), 2.08 (s, 3H), 1.81 (s, 3H), 1.79 (s, 3H). MS (ESI) Calcd for
C33H24F8IrN4P: C 46.53, H 2.84, N 6.58, Anal. found: C 46.36, H 3.04,
N 6.75.
C
28H23F2IrN2O2 650.1357; Found 650.1352.
2.2.5.2. [Ir(dfppy)(tpy)(phen)](PF6). (0.185 g, 82%), 1H NMR
(300 MHz, CDCl3, ppm): 9.05 (d, 3J ¼ 7.8 Hz, 1H), 8.99 (d, 3J ¼ 8.1 Hz,
1H), 8.51 (m, 2H), 8.32 (m, 2H), 8.24 (d, 3J ¼ 4.8 Hz,1H), 7.97 (m, 2H),
7.90 (d, 3J ¼ 7.8 Hz,1H), 7.75 (m, 2H), 7.65 (d, 3J ¼ 7.8 Hz,1H), 7.38 (d,
3J ¼ 5.7 Hz, 1H), 7.24 (d, 3J ¼ 5.7 Hz, 1H), 6.97 (m, 2H), 6.88 (t,
3J ¼ 6.6 Hz, 1H), 6.59 (m, 1H), 6.13 (s, 1H), 5.88 (dd, 3J ¼ 8.1 Hz,
4J ¼ 2.4 Hz, 1H), 2.22 (s, 3H). MS (ESI) Calcd for [C35H24F2IrN4]þ
731.1600; Found 731.1613. Anal. calcd for C35H24F8IrN4P: C 48.00, H
2.76, N 6.40, Anal. found: C 47.94, H 2.86, N 6.45.
2.2.2.3. Ir(tpy)2(acac). (0.28 g, 22%): 1H NMR (300 MHz, CDCl3,
ppm): 8.49 (d, 3J ¼ 5.4 Hz, 2H), 7.81 (d, 3J ¼ 7.8 Hz, 2H), 7.71 (t,
3J ¼ 7.5 Hz, 2H), 7.45 (d, 3J ¼ 8.1 Hz, 2H), 7.10 (m, 2H), 6.64 (d,
3J ¼ 7.8 Hz, 2H), 6.08 (s, 2H), 5.21 (s,1H), 2.06 (s, 6H),1.79 (s, 6H). MS
(ESI) Calcd for C29H27IrN2O2 628.1702; Found 628.1704.
2.2.3. Ir(C^N)2Cl2Ir(C^N)2
To a suspension of HC^N (3.5 mmol) (2-(2,4-difluorophenyl)
pyridine or 2-(4-methylphenyl)pyridine) in 2-ethoxyethanol/water
(75: 25, 40 mL) was added IrCl3$3H2O (0.344 g, 1.0 mmol). The
reaction mixture was stirred at reflux for 24 h. Then, water (50 mL)
was added and the product was filtered, washed, with ethanol and
diethyl ether. The product was then isolated as a yellow powders.
2.2.5.3. [Ir(dfppy)2(bpy)](PF6). (0.17 g, 77%). 1H NMR (300 MHz,
CDCl3, ppm): 8.34 (m, 4H), 7.87 (m, 6H), 7.50 (m, 4H), 7.10 (m, 2H),
6.60 (m, 2H), 5.71 (d, 3J ¼ 8.4 Hz, 2H). MS (ESI) Calcd for
[C32H20F4IrN4]þ 729.1248; Found 729.1245.
2.2.5.4. [Ir(tpy)2(bpy)](PF6). (0.18 g, 86%).1H NMR (300 MHz, CDCl3,
ppm): 9.61 (m, 2H), 8.26 (m, 2H), 7.87 (m, 4H), 7.74 (t, 3J ¼ 7.5 Hz),
7.59 (d, 3J ¼ 8.1 Hz, 2H), 7.42 (m, 4H), 6.95 (m, 2H), 6.86 (d,
3J ¼ 7.8 Hz), 6.10 (s, 2H), 2.15 (s, 6H). MS (ESI) Calcd for
[C34H28IrN4]þ 685.1938; Found 685.1941.
2.2.3.1. Ir(dfppy)2Cl2Ir(dfppy)2. (0.53 g, 93%). 1H NMR (300 MHz,
CDCl3, ppm): 9.15 (d, 3J ¼ 6.0 Hz, 4J ¼ 1.5 Hz, 4H), 8.32 (d, 3J ¼ 8.4 Hz,
4H), 7.85 (dt, 3J ¼ 7.8 Hz, 4J ¼ 0.9 Hz, 4H), 6.84 (m, 4H), 6.35 (m, 4H),
5.30 (d, 3J ¼ 9.0 Hz, 4J ¼ 2.1 Hz, 4H). MS (ESI) Calcd for
C
44H24Cl2F8Ir2N4 1216.0509; Found 1216.0514.
2.2.5.5. [Ir(dfppy)2(phen)](PF6). (0.2 g, 88%) 1H NMR (300 MHz,
CDCl3, ppm): 8.79 (d, 3J ¼ 8.4 Hz, 2H), 8.32 (m, 6H), 7.92 (m, 2H),
7.78 (t, 3J ¼ 7.5 Hz, 2H), 7.35 (d, 3J ¼ 5.4 Hz, 2H), 6.98 (t, 3J ¼ 6.9 Hz,
2H), 6.40 (m, 2H), 5.80 (dd, 3J ¼ 8.4 Hz, 4J ¼ 1.8 Hz, 2H). MS (ESI)
Calcd for [C34H20F4IrN4]þ 753.1248; Found 753.1247.
2.2.3.2. Ir(tpy)2Cl2Ir(tpy)2. (0.5 g, 89%). 1H NMR (300 MHz, CDCl3,
ppm): 9.18 (d, 3J ¼ 5.1 Hz, 4H), 7.82 (d, 3J ¼ 8.1 Hz, 4H), 7.71 (t,
3J ¼ 8.1 Hz, 4H), 7.38 (d, 3J ¼ 8.1 Hz, 4H), 6.73 (t, 3J ¼ 6.3 Hz, 4H), 6.57
(d, 3J ¼ 7.5 Hz, 4H), 5.76 (s, 4H), 1.94 (s, 12 H). MS (ESI) Calcd for
C
48H40Cl2Ir2N4 1128.1889; Found 1128.1906.
2.2.5.6. [Ir(tpy)2(phen)](PF6). (0.14 g, 64%). 1H NMR (300 MHz,
CDCl3, ppm): 8.75 (m, 2H), 8.28 (m, 4H), 7.88 (m, 4H), 7.71 (m, 2H),
7.63 (d, 3J ¼ 7.2 Hz, 2H), 7.32 (m, 2H), 6.92 (d, 3J ¼ 7.2 Hz, 2H), 6.87
(m, 2H), 6.22 (s, 2H), 2.19 (s, 6H). MS (ESI) Calcd for [C36H28IrN4]þ
709.1945; Found 709.1937.
2.2.4. Ir(dfppy)(tpy)Cl2Ir(dfppy)(tpy)
To a solution of Ir(dfppy)(tpy)(acac) (0.4 g, 0.615 mmol) in
dichloromethane (20 mL) was added at 0 ꢁC a solution of HCl in
diethyl ether (1.2 mol Lꢀ1, 10 mL). The reaction mixture was stirred
for 1 h. Then, methanol (30 mL) was added and the dichloro-
methane was evaporated. The methanol solution was then filtered
off and the product was isolated as a yellow powder (0.306 g, 85%
yield). 1H NMR (300 MHz, CDCl3, ppm): 9.21 (m, 1H), 9.11 (m, 1H),
8.29 (m, 1H), 7.82 (m, 3H), 7.42 (m, 1H), 6.81 (m, 2H), 6.65 (m, 1H),
2.3. LECs fabrication and measurements
All materials used for the device fabrication were purchased
from Lumtec with the best purity available and used as received.