C.-H. Siu et al. / Journal of Organometallic Chemistry xxx (2013) 1e9
3
for 5 min. Pd(PPh3)4 (100 mg) was added and the resulting
mixture was heated to reflux for two days. After being cooled to
room temperature, water was added and the mixture was
extracted with ethyl acetate. The combined organic fractions were
dried over Na2SO4, filtered, and concentrated under reduced
pressure. The crude compound was purified by silica gel column
chromatography using CH2Cl2/n-hexane (1:1, v/v) as eluent to
afford L1 as a yellow solid (0.65 g, 1.8 mmol, 60%). 1H NMR
to the reaction mixture, which was then heated at 45 ꢀC for 20 h.
The solution was purified by aluminum oxide column chroma-
tography [Al2O3 (basic): CH2Cl2/CH3CN, 9:1]. The first yellow band
was isolated and then reconstituted in dichloromethane. A yellow
solid of [Ru(CH3CN)4(L1)]þPFe6 (120 mg, 0.170 mmol, 58%) was
drawn out of the solution by the slow addition of n-hexane. 1H
NMR (400 MHz, CD3CN):
d
¼ 8.37 (s, 1H, Ar), 8.23e8.21 (m, 2H,
Ar), 8.07 (d, J ¼ 7.7 Hz, 1H, Ar), 7.57 (d, J ¼ 3.6 Hz, 1H, Ar), 7.50e
7.48 (m, 1H, Ar), 7.45e7.41 (m, 1H, Ar), 7.22e7.18 (m, 1H, Ar), 4.52e
4.48 (m, 2H, alkyl), 1.97e1.94 (m, 2H, alkyl), 1.45e1.39 (m, 2H,
alkyl), 0.98e0.94 (m, 3H, alkyl), 2.19 (s, 3H, NCCH3), 2.15 (s, 3H,
NCCH3), 2.01 (s, 3H, NCCH3), 1.99 (s, 3H, NCCH3) ppm. MALDI-TOF:
m/z ¼ 571 (Mþ).
(400 MHz, CDCl3):
d
¼ 8.73 (dd, J ¼ 1.7, 0.4 Hz, 1H, Ar), 8.18e8.15
(m, 1H, Ar), 8.09 (dd, J ¼ 8.7, 1.8 Hz, 1H, Ar), 7.87 (d, J ¼ 3.3 Hz, 1H,
Ar), 7.52e7.48 (m, 1H, Ar), 7.45e7.42 (m, 2H, Ar), 7.30e7.27 (m,
2H, Ar), 4.35e4.29 (m, 2H, alkyl), 1.92e1.84 (m, 2H, alkyl), 1.45e
1.39 (m, 2H, alkyl), 0.98e0.94 (m, 3H, alkyl) ppm. 13C NMR
(100 MHz, CDCl3):
d
¼ 169.85, 143.37, 141.52, 141.05, 126.23,
124.92, 124.64, 123.23, 122.92, 120.74, 119.47, 118.88, 117.60,
109.05, 108.97 (Ar), 43.06, 31.13, 20.56, 13.88 (alkyl) ppm. MALDI-
TOF: m/z ¼ 305 (Mþ).
2.3.2. [Ru(CH3CN)4(L2)]þPF6e
Yield: 32%; yellow solid. 1H NMR (400 MHz, CD3CN):
d
¼ 8.18 (d,
J ¼ 3.6 Hz, 1H, Ar), 7.73 (d, J ¼ 2.2 Hz, 1H, Ar), 7.55 (d, J ¼ 3.6 Hz, 1H,
Ar), 7.48 (d, J ¼ 8.3 Hz, 1H, Ar), 7.38e7.33 (m, 4H, Ar), 7.20e7.12 (m,
6H, Ar), 6.73 (dd, J ¼ 8.4, 2.2 Hz, 1H, Ar), 2.18 (s, 3H, NCCH3), 2.14 (s,
3H, NCCH3), 2.01 (s, 3H, NCCH3), 1.98 (s, 3H, NCCH3) ppm. MALDI-
TOF: m/z ¼ 593 (Mþ).
2.2.2. N,N-Diphenyl-4-(thiazol-2-yl)aniline (L2)
The same synthetic procedure as L1 was applied but 4-(diphe-
nylamino)phenylboronic acid was used instead. Yield: 60%; yellow
solid. 1H NMR (400 MHz, CDCl3):
d
¼ 7.81e7.79 (m, 3H, Ar), 7.31e
7.29 (m, 3H, Ar), 7.27e7.25 (m, 2H, Ar), 7.15e7.12 (m, 4H, Ar), 7.10e
7.06 (m, 4H, Ar) ppm. 13C NMR (100 MHz, CDCl3):
2.3.3. [Ru(CH3CN)4(L3)]þPF6e
d
¼ 168.28,
Yield: 57%, yellow solid. 1H NMR (400 MHz, CD3CN):
d
¼ 8.63 (s,
149.49, 147.08, 143.43, 129.41, 127.47, 127.03, 125.07, 123.67, 122.35,
1H, Ar), 8.36e8.34 (m, 2H, Ar), 8.17 (d, J ¼ 7.6 Hz, 1H, Ar), 8.10 (d,
J ¼ 7.4 Hz, 1H, Ar), 7.82e7.78 (m, 1H, Ar), 7.61e7.57 (m, 2H, Ar),
7.53e7.49 (m, 1H, Ar), 7.30e7.27 (m, 1H, Ar), 3.82e3.79 (m, 2H,
alkyl), 2.16 (s, 3H, NCCH3), 2.14 (s, 3H, NCCH3), 2.01 (s, 3H, NCCH3),
1.99 (s, 3H, NCCH3), 1.43e1.39 (m, 2H, alkyl), 0.99e9.97 (m, 2H,
alkyl), 0.69e0.65 (m, 3H, alkyl) ppm. MALDI-TOF: m/z ¼ 621 (Mþ).
117.79 (Ar) ppm. MALDI-TOF: m/z ¼ 327 (Mþ).
2.2.3. 2-(9-Butyl-9H-carbazol-3-yl)benzo[d]thiazole (L3)
A
mixture of 9-butyl-9H-carbazole-3-carbaldehyde (2 g,
8.76 mmol) and 2-aminobenzenethiol (1.65 g, 13.1 mmol) in water
(60 mL) was stirred at 110 ꢀC for 3 h. The mixture was cooled and
extracted with dichloromethane. The organic layer was dried over
Na2SO4, filtered, and concentrated under reduced pressure. The
residue was purified by silica gel column chromatography using
CH2Cl2/n-hexane (2:1, v/v) as eluent to afford L3 as a yellow solid
2.3.4. [Ru(CH3CN)4(L4)]þPF6e
Yield: 59%; yellow solid. 1H NMR (400 MHz, CD3CN):
d
¼ 8.33 (d,
J ¼ 8.3 Hz, 1H, Ar), 8.04 (d, J ¼ 7.7 Hz, 1H, Ar), 7.81e7.76 (m, 2H, Ar),
7.67 (d, J ¼ 8.4 Hz, 1H, Ar), 7.57e7.53 (m, 1H, Ar), 7.45e7.41 (m, 4H,
Ar), 7.28e7.20 (m, 6H, Ar), 6.80 (dd, 1J ¼ 8.4 Hz, 2J ¼ 2.2 Hz, 1H, Ar),
2.16 (s, 3H, NCCH3), 2.13 (s, 3H, NCCH3), 2.02 (s, 3H, NCCH3), 1.97
(s, 3H, NCCH3) ppm. MALDI-TOF: m/z ¼ 643 (Mþ).
(1 g, 2.81 mmol, 32%). 1H NMR (400 MHz, CDCl3):
d
¼ 8.86e8.85 (m,
1H, Ar), 8.22e8.19 (m, 2H, Ar), 8.09e8.07 (m, 1H, Ar), 7.93e7.90 (m,
1H, Ar), 7.52e7.44 (m, 4H, Ar), 7.39e7.35 (m, 1H, Ar), 7.32e7.28 (m,
1H, Ar), 4.37e4.33 (m, 2H, alkyl), 1.93e1.86 (m, 2H, alkyl), 1.46e1.40
(m, 2H, alkyl), 0.99e0.95 (m, 3H, alkyl) ppm. 13C NMR (100 MHz,
2.4. Procedures for the synthesis of ruthenium dyes D1eD4
CDCl3):
d
¼ 169.43, 154.41, 142.14, 141.10, 134.92, 126.37, 126.20,
125.53, 124.66, 123.31, 122.93, 122.68, 121.52, 120.86, 120.05, 119.69,
109.14, 109.02 (Ar), 43.11, 31.13, 22.68, 14.14 (alkyl) ppm. MALDI-
TOF: m/z ¼ 355 (Mþ).
Same synthetic procedures were applied for D1eD4. A typical
example is given for D1.
2.4.1. D1
2.2.4. 4-(Benzo[d]thiazol-2-yl)-N,N-diphenylaniline (L4)
To a flask containing [Ru(CH3CN)4(L1)]þPF6e (100 mg, 0.140mmol)
in methanol (15 mL), 2,20-bipyridine-4,40-dicarboxylic acid (dcbpy)
(68 mg, 0.280 mmol) and NaOH (22.4 mg, 0.560 mmol) were added.
The solution was refluxed overnight at 100 ꢀC. The dark purple
mixture was dissolved in distilled water and acidified with a few
drops of 0.2 M HNO3, until a precipitate was formed. The dark purple
precipitate was filtered by silica gel column chromatography using
methanol as eluent. The solution was concentrated under reduced
pressure. The compound was then washed with diethyl ether to give
D1 as a dark purple solid (95 mg, 0.091 mmol, 65%). 1H NMR
The same synthetic procedure as L3 was applied but 4-(diphe-
nylamino)benzaldehyde was used instead. Yield: 25%; yellow solid.
1H NMR (400 MHz, CD3OD):
d
¼ 8.03e8.00 (m, 1H, Ar), 7.93e7.91
(m, 2H, Ar), 7.88e7.86 (m, 1H, Ar), 7.48e7.44 (m, 1H, Ar), 7.37e7.28
(m, 5H, Ar), 7.18e7.17 (m, 4H, Ar), 7.13e7.09 (m, 4H, Ar) ppm. 13C
NMR (100 MHz, CDCl3):
d
¼ 168.12, 154.53, 150.74, 147.15, 135.06,
129.87, 128.88, 126.81, 126.79, 126.40, 125.72, 125.00, 124.32,
123.00, 122.04, 121.73 (Ar) ppm. MALDI-TOF: m/z ¼ 377 (Mþ).
2.3. Procedures for the synthesis of ruthenium intermediate
(400 MHz, CD3OD):
d
¼ 9.03 (s,1H, Ar), 8.96 (s,1H, Ar), 8.94 (s,1H, Ar),
8.87 (s, 1H, Ar), 8.41 (s, 1H, Ar), 8.28 (d, J ¼ 5.9 Hz, 1H, Ar), 8.09 (d,
J ¼ 5.5 Hz,1H, Ar), 8.00e7.95 (m, 3H, Ar), 7.88 (dd, J ¼ 5.5, 1.5 Hz,1H,
Ar), 7.77 (dd, J¼ 5.5,1.5Hz,1H, Ar), 7.67 (dd, J¼ 5.5,1.5Hz,1H, Ar), 7.60
(dd, J ¼ 5.5,1.5Hz,1H, Ar), 7.36(d, J ¼ 3.5 Hz,1H, Ar), 7.29 (d, J ¼ 3.7Hz,
2H, Ar), 7.11e7.08 (m, 1H, Ar), 6.69 (d, J ¼ 3.5 Hz, 1H, Ar), 6.26 (s, 1H,
Ar), 3.95e3.91 (m, 2H, alkyl), 1.55e1.48 (m, 2H, alkyl), 1.11e1.08 (m,
2H,alkyl),0.81e0.77 (m, 3H,alkyl)ppm. MALDI-TOF:m/z¼ 895 (Mþ).
Anal. Calc. for C43H33F6N6O8PRuS: C, 49.67; H, 3.20; N, 8.08. Found: C,
49.89; H, 3.45; N, 8.22.
Similar procedures were applied for the synthesis of Ru(II) in-
termediates with the corresponding cyclometalating ligands.
[Ru(CH3CN)4(L1)]þPF6ꢁ was taken as a typical example.
2.3.1. [Ru(CH3CN)4(L1)]þPF6e
To a flask containing [Ru(C6H6)Cl2]2 (150 mg, 0.295 mmol), L1
(180 mg, 0.590 mmol) and KPF6 (190 mg, 1.03 mmol) was added
degassed CH3CN (10 mL). NaOH (24 mg, 0.590 mmol) was added
j.jorganchem.2013.04.023