Journal of Materials Chemistry C
Paper
30 min, followed by addition of bromoethane. Aer cooling to temperature. The solvent was removed under reduced pressure.
room temperature, the reactant mixture was heated to reux The crude product was puried by silica gel column chroma-
overnight and quenched with ice water. The mixture was then tography using dichloromethane/ethyl acetate (6 : 1) and the
extracted by dichloromethane (3 ꢂ 30 mL). The organic layer resulting powders were recrystallized from the dichloro-
was dried with Na2SO4, and the solvent was removed under methane and petroleum ether mixture to give complex 1 as a
vacuum. The product was then obtained by column chroma- light-yellow solid with a yield of 58%. 1H-NMR (500 MHz,
tography on silica gel with ethyl acetate/petroleum (1 : 3) as the deuterated dimethyl sulfoxide (DMSO-d6), ppm): d 8.08 (t, J ¼
1
eluent to produce a light-yellow solid with a yield of 64%. H- 7.5 Hz, 1H), 7.98 (d, J ¼ 7.5 Hz, 1H), 7.94 (d, J ¼ 4.5 Hz, 1H), 7.90
NMR (500 MHz, deuterated chloroform (CDCl3), ppm): d 7.83– (d, J ¼ 7.0 Hz, 1H), 7.82 (d, J ¼ 8.0 Hz, 1H), 7.71–7.78 (m, 3H),
7.85 (m, 1H), 7.72–7.73 (m, 2H), 7.51–7.53 (m, 3H), 7.42 (t, J ¼ 7.65 (t, J ¼ 7.0 Hz, 1H), 7.35–7.45 (m, 4H), 7.24–7.31 (m, 5H),
4.5 Hz, 1H), 7.30–7.32 (m, 2H), 4.25–4.29 (m, 2H), 1.44 (t, J ¼ 7 7.13–7.17 (m, 2H), 7.04–7.09 (m, 2H), 6.85 (t, J ¼ 8.0 Hz, 2H),
Hz, 3H). The related cyclometalated ligands (L2, L3, L4 and L5) 6.77 (t, J ¼ 7.0 Hz, 1H), 6.70 (t, J ¼ 7.0 Hz, 1H), 6.61 (t, J ¼ 7.0 Hz,
were prepared using similar procedures.
1H), 6.26 (d, J ¼ 8.0 Hz, 1H), 5.96 (d, J ¼ 8.0 Hz, 1H), 5.87 (d, J ¼
1
Butyl-2-phenyl-1H-benzo[d]imidazole (L2). H-NMR (500 MHz, 8.0 Hz, 1H), 4.93–4.95 (m, 2H), 4.66–4.71 (m, 1H), 4.55–4.60 (m,
CDCl3, ppm): d 7.83–7.85 (m, 1H), 7.70–7.72 (m, 2H), 7.51–7.53 1H), 1.52 (t, J ¼ 7.0 Hz, 3H), 1.23 (t, J ¼ 6.5 Hz, 5H). 19F-NMR
(m, 3H), 7.41 (t, J ¼ 4.5 Hz, 1H), 7.30–7.32 (m, 2H), 4.21 (t, J ¼ 7.5 (470 MHz, DMSO-d6, ppm): ꢁ67.30 (d, J ¼ 710.17 Hz, 6F). MS
Hz, 2H), 1.78 (t, J ¼ 7.5 Hz, 2H), 1.24–1.29 (m, 2H), 0.84 (t, J ¼ 7.5 (MALDI-TOF): m/z 933.3 (M–PF6). The related complexes 2, 3, 4
Hz, 3H).
Hexyl-2-phenyl-1H-benzo[d]imidazole (L3). 1H-NMR (500 MHz,
and 5 were prepared using similar procedures.
Synthesis and characterization of complex 2. Light-yellow solid,
1
CDCl3, ppm): d 7.83–7.85 (m, 1H), 7.70–7.72 (m, 2H), 7.51–7.53 (yield: 67%). H-NMR (500 MHz, DMSO-d6, ppm): d 8.06 (t, J ¼
(m, 3H), 7.40 (t, J ¼ 4.5 Hz, 1H), 7.29–7.31 (m, 2H), 4.19 (t, J ¼ 7.5 8.0 Hz, 1H), 7.97 (d, J ¼ 7.0 Hz, 1H), 7.91 (t, J ¼ 5.0 Hz, 1H), 7.90
Hz, 2H), 1.79 (t, J ¼ 7.0 Hz, 2H), 1.21–1.24 (m, 6H), 0.84 (t, J ¼ 6.5 (s, 1H), 7.83 (d, J ¼ 8.5 Hz, 1H), 7.71–7.78 (m, 3H), 7.65 (t, J ¼ 7.0
Hz, 3H).
Hz, 1H), 7.46 (d, J ¼ 7.0 Hz, 2H), 7.35–7.41 (m, 2H), 7.23–7.33
1
Octyl-2-phenyl-1H-benzo[d]imidazole (L4). H-NMR (500 MHz, (m, 5H), 7.12–7.18 (m, 2H), 7.05 (t, J ¼ 7.0 Hz, 1H), 7.00 (d, J ¼
CDCl3, ppm): d 7.83–7.84 (m, 1H), 7.70–7.71 (m, 2H), 7.50–7.51 7.5 Hz, 1H), 6.85 (t, J ¼ 7.5 Hz, 2H), 6.75 (t, J ¼ 7.5 Hz, 1H), 6.71
(m, 3H), 7.41 (t, J ¼ 3.0 Hz, 1H), 7.29–7.31 (m, 2H), 4.19 (t, J ¼ 7.5 (t, J ¼ 7.5 Hz, 1H), 6.58 (t, J ¼ 8.0 Hz, 1H), 6.21 (d, J ¼ 8.0 Hz,
Hz, 2H), 1.78 (t, J ¼ 7 Hz, 2H), 1.19–1.27 (m, 10H), 0.84 (t, J ¼ 6.5 1H), 5.98 (d, J ¼ 7.5 Hz, 1H), 5.87 (d, J ¼ 8.5 Hz, 1H), 4.86–4.97
Hz, 3H).
(m, 2H), 4.65–4.68 (m, 1H), 4.53–4.59 (m, 1H), 1.90 (t, J ¼ 7.0 Hz,
1-decyl-2-phenyl-1H-benzo[d]imidazole (L5). 1H-NMR (500 2H), 1.55 (t, J ¼ 7.5 Hz, 2H), 1.26–1.39 (m, 4H), 0.89 (t, J ¼ 7.0 Hz,
MHz, CDCl3, ppm): d 7.81–7.82 (m, 1H), 7.64–7.66 (m, 2H), 7.41– 6H). 19F-NMR (470 MHz, DMSO-d6, ppm): ꢁ67.30 (d, J ¼ 711.11
7.46 (m, 3H), 7.32–7.34 (m, 1H), 7.23–7.26 (m, 2H), 4.12 (t, J ¼ Hz, 6F). MS (MALDI-TOF): m/z 989.4 (M–PF6).
7.5 Hz, 2H), 1.72–1.74 (m, 2H), 1.16–1.27 (m, 14H), 0.85 (t, J ¼ 7
Synthesis and characterization of complex 3. Light-yellow solid,
1
Hz, 3H).
(yield: 52%). H-NMR (500 MHz, DMSO-d6, ppm): d 8.08 (t, J ¼
Synthesis of the ancillary ligand. 2-(1,3-diphenyl-1H-1,2,4-tri- 8.0 Hz, 1H), 7.99 (d, J ¼ 7.5 Hz, 1H), 7.91–7.94 (m, 2H), 7.85 (d, J
azol-5-yl) pyridine (Phtz) was synthesized according to previ- ¼ 8.0 Hz, 1H), 7.72–7.80 (m, 3H), 7.66 (t, J ¼ 6.5 Hz, 1H), 7.45 (d,
ously reported procedures, which produced a white solid with a J ¼ 7.5 Hz, 2H), 7.37–7.43 (m, 2H), 7.24–7.33 (m, 5H), 7.13–7.19
yield of 75%. 1H-NMR (500 MHz, CDCl3, ppm): d 8.51 (d, J ¼ 4.5 (m, 2H), 7.06 (t, J ¼ 8.0 Hz, 1H), 7.02 (d, J ¼ 7.5 Hz, 1H), 6.86 (t, J
Hz, 1H), 8.25 (d, J ¼ 7.5 Hz, 2H), 7.94 (d, J ¼ 8.0 Hz, 1H), 7.77 (t, J ¼ 7.5 Hz, 2H), 6.76 (t, J ¼ 7.5 Hz, 1H), 6.72 (t, J ¼ 7.5 Hz, 1H),
¼ 8.0 Hz, 1H), 7.42–7.49 (m, 8H), 7.30 (t, J ¼ 6 Hz, 1H).
6.58 (t, J ¼ 7.5 Hz, 1H), 6.23 (d, J ¼ 8.0 Hz, 1H), 6.00 (d, J ¼ 8.0
Synthesis of the chloro-bridged dimer. The organometallated Hz, 1H), 5.87 (d, J ¼ 8.0 Hz, 1H), 4.95–4.98 (m, 1H), 4.87–4.90
dimer [Ir(L1)2Cl]2 was synthesized by reacting IrCl3$3H2O (0.505 (m, 1H), 4.66–4.69 (m, 1H), 4.54–4.59 (m, 1H), 1.92 (t, J ¼ 7.0 Hz,
g, 1.43 mmol) with 1-methyl-2-phenyl-1H-benzo[d]imidazole (L1; 2H), 1.58 (s, 2H), 1.19–1.38 (m, 12H), 0.78–0.84 (m, 6H). 19F-
0.656 g, 3.15 mmol) in a 2-ethoxyethanol and water mixture (3 : 1 NMR (470 MHz, DMSO-d6, ppm): ꢁ67.30 (d, J ¼ 710.17 Hz, 6F).
v/v, 30 mL) for 24 h. The product was ltered out and washed with MS (MALDI-TOF): m/z 1045.3 (M–PF6).
diethyl ether followed by ethanol, and dried (yield: 76%). Other
Synthesis and characterization of complex 4. Yellow-green
1
chloride-bridged complexes, [Ir(L2)2Cl]2, [Ir(L3)2Cl]2, [Ir(L4)2Cl]2 solid, (yield: 76%). H-NMR (500 MHz, DMSO-d6, ppm): d 8.07
and [Ir(L5)2Cl]2, were synthesized using a method similar to that (t, J ¼ 7.0 Hz, 1H), 7.96 (d, J ¼ 8.0 Hz, 1H), 7.89–7.92 (m, 2H),
for [Ir(L1)2Cl]2. The chloro-bridged dimers were used in the 7.84 (d, J ¼ 7.5 Hz, 1H), 7.71–7.78 (m, 3H), 7.64 (t, J ¼ 6.5 Hz,
subsequent reactions without further purication.
Synthesis and characterization of complexes 1–5
1H), 7.43 (d, J ¼ 7.5 Hz, 2H), 7.35–7.41 (m, 2H), 7.22–7.31 (m,
5H), 7.11–7.17 (m, 2H), 7.04 (t, J ¼ 8.0 Hz, 1H), 7.00 (d, J ¼ 7.5
Synthesis and characterization of complex 1. A solution of Hz, 1H), 6.85 (t, J ¼ 7.5 Hz, 2H), 6.74 (t, J ¼ 7.5 Hz, 1H), 6.70 (t, J
ancillary ligand (0.172 g, 0.63 mmol) and the dichloro-bridged ¼ 7.0 Hz, 1H), 6.56 (t, J ¼ 7.5 Hz, 1H), 6.21 (d, J ¼ 7.5 Hz, 1H),
diiridium complex [Ir(L1)2Cl]2 (0.386 g, 0.3 mmol) in a mixture 5.98 (d, J ¼ 8.0 Hz, 1H), 5.85 (d, J ¼ 8.5 Hz, 1H), 4.94–4.97 (m,
of methanol (15 mL) and dichloromethane (30 mL) was reuxed 1H), 4.86–4.89 (m, 1H), 4.64–4.67 (m, 1H), 4.54–4.57 (m, 1H),
for 24 h in the dark. Aer cooling to room temperature, the 1.92–1.93 (m, 2H), 1.58 (s, 2H), 1.17–1.36 (m, 20H), 0.79–0.82
mixture was ltered, and then an excess of solid KPF6 was added (m, 6H). 19F-NMR (470 MHz, DMSO-d6, ppm): ꢁ67.30 (d, J ¼
and the mixture was stirred for another 0.5 h at room 710.17 Hz, 6F). MS (MALDI-TOF): m/z 1101.5 (M–PF6).
7650 | J. Mater. Chem. C, 2014, 2, 7648–7655
This journal is © The Royal Society of Chemistry 2014