K. K.-W. Lo, V. Guerchais et al.
FULL PAPER
Synthesis of 4-(4-Nitrostyryl)-2-phenylpyridine (1d): To a solution
∧
[Ir(C N(ppy-4-Me)2]2(µ-Cl)2 (3e): Yield 0.45 g (96%). 1H NMR
3
of
4-[(diethoxyphosphoryl)methyl]-2-phenylpyridine
(0.71 g,
(300 MHz, CD2Cl2): δ = 9.10 (d, J = 6 Hz, 4 H, py6), 7.79 (br. s,
3
4
2.33 mmol) and p-nitrobenzaldehyde (0.52 g, 3.45 mmol) in THF 4 H, py3), 7.57 (dd, J = 7.8 Hz, J = 1.3 Hz, 4 H, Ph3), 6.83 (td,
(20 mL) was added tBuOK (0.65 g, 5.8 mmol). The reaction mix-
ture was stirred for 2 h and then hydrolysed with water (20 mL).
THF was removed under reduced pressure, and the residue was
extracted with CH2Cl2 (3ϫ50 mL). The organic phase was dried
with MgSO4. The solvent was evaporated, and chromatography on
silica gel with heptane/ethyl acetate (80:20) afforded 1d as a yellow
powder. Yield 0.640 g (91%). 1H NMR (500 MHz, CDCl3): δ =
8.74 (d, 3J = 5 Hz, 1 H, py6), 8.29 (d, 3J = 8.7 Hz, 2 H, C6H4),
3J = 7.4 Hz, 4J = 1.2 Hz, 4 H, Ph4), 6.68 (dd, 3J = 6 Hz, 4J =
1.2 Hz, 4 H, py5), 6.62 (td, 3J = 7.6 Hz, 4J = 1.4 Hz, 4 H, Ph5),
5.93 (td, J = 7.8 Hz, J = 1.1 Hz, 4 H, Ph6), 2.70 (s, 12 H, CH3)
ppm. HRMS: calcd. for C48H38Cl2193Ir2N4 [M – Cl]+ 1092.2200;
found 1093.2206.
3
4
∧
∧
Syntheses of Bis-Cyclometallated Complexes Ir(C N)2(O O) 4 and
5: In a Schlenk tube, to a 2-ethoxyethanol solution (10 mL) were
added the chloro-bridged iridium dimer (0.057 mmol), 1,3-diketone
(acetylacetone or dipyvaloylmethane) (0.14 mmol) and Na2CO3
(60 mg, 0.57 mmol). The reaction mixture was heated for 15 h.
When the reaction mixture was heated at 140 °C, the hydrogenated
compounds 4a-H2 and 1a-H2 were isolated, whereas at 80 °C the
pure styryl derivatives 4,5 were obtained. After addition of water
(20 mL), the precipitate was filtered and washed with water and
diethyl ether. The products were then isolated as powders after
crystallization from a mixture of CH2Cl2/Et2O.
8.06 (m, 2 H, Ph ortho), 7.84 (s, 1 H, py3), 7.73 (d, J = 8.7 Hz, 2
H, C6H4), 7.53 (m, 2 H, Ph meta), 7.48 (m, 1 H, Ph para), 7.42 (d,
3
3J = 16 Hz, 1 H, =CH), 7.39 (dd, J = 5 Hz, J = 1 Hz, 1 H, py5),
7.28 (d, 1 H, =CH) ppm. 13C{1H} NMR (125 MHz, CDCl3): δ =
158.4 (C2-py), 150.3 (C6-py), 147.5 (C1-C6H4), 144.2 (C4-py), 142.6
(C4-C6H4), 139.2 (Ph ipso), 130.8 (=CH), 130.6 (=CH), 129.3 (Ph
para), 128.9 (Ph meta), 127.5 (C3-C6H4), 127.0 (Ph ortho), 124.3
(C2-C6H4), 119.4 (C5-py), 118.3 (C3-py) ppm. HRMS: calcd. for
C19H14N2O2 [M]+ 302.1055; found 302.1059. C19H14N2O2 (302.33):
calcd. C 75.48, H 4.67, N 9.27; found C 75.03, H 4.62, N 9.07.
3
4
∧
Ir(C N-ppy-4-CH2CH2C6H4OMe)2(acac) (4a-H2): Yellow powder.
Yield 0.045 g (46%). H NMR (300 MHz, CD2Cl2): δ = 8.36 (d, 3J
1
∧
Syntheses
of
Chloro-Bridged
Dimers
[Ir(C N-ppy-4-
3
= 5.7 Hz, 2 H, py6), 7.70 (s, 2 H, py3), 7.56 (d, J = 7.5 Hz, 2 H,
CH=CHC6H4R)2]2(µ-Cl)2 (3): A Schlenk flask was charged with
IrCl3·3H2O (0.289 g, 0.82 mmol), the appropriate ligand HC N
(3.5 equiv.) and a mixture of 2-ethoxyethanol/water, (75:25, 10 mL).
The mixture was refluxed for 24 h. The precipitate was then washed
with water, ethanol and acetone.
3
3
Ph3), 7.19 (d, J = 8.2 Hz, 4 H, C6H4), 7.01 (d, J = 6.0 Hz, 2 H,
∧
3
py5), 6.88 (m, 6 H, C6H4 and Ph4), 6.73 (t, J = 7.5 Hz, 2 H, Ph5),
6.24 (d, 3J = 7.5 Hz, 2 H, Ph6), 5.31 (s, 1 H, CH), 3.82 (s, 6 H,
OCH3), 3.14 (m, 4 H, CH2), 3.07 (m, 4 H, CH2), 1.83 (s, 6 H, CH3)
ppm. 13C{1H} NMR (75 MHz, CD2Cl2): δ = 184.5 (CO), 167.6
(C2-py), 158.2 (C1-C6H4), 152.3 (C4-py), 147.6 (C6-py), 147.4 (C1-
Ph), 145.3 (C2-Ph), 133.1 (C6-Ph), 132.6 (C4-C6H4), 129.4 (C3-
C6H4), 128.5 (C5-Ph), 123.5 (C3-Ph), 122.3 (C5-py), 120.6 (C4-Ph),
118.6 (C3-py), 113.9 (C2-C6H4), 100.2 (CH), 55.2 (OCH3), 37.5
(CH2), 35.7 (CH2), 28.3 (CH3) ppm. HRMS: calcd. for
∧
[Ir(C N-ppy-4-CH=CHC6H4OMe)2]2(µ-Cl)2 (3a): Yield 0.62 g
1
3
(95%). H NMR (500 MHz, CD2Cl2): δ = 9.15 (d, J = 5.9 Hz, 4
H, py6), 7.94 (s, 4 H, py3), 7.62 (d, J = 7.5 Hz, 8 H, C6H4), 7.39
3
3
(m, 8 H, =CH and Ph), 7.12 (d, J = 16 Hz, 4 H, =CH), 6.93 (d,
4 H, py5), 6.82 (m, 12 H, C6H4 and Ph), 6.32 (t, J = 6.8 Hz, 4 H,
3
C45H43193IrN2O4Na [M
+
Na]+ 891.2750; found 891.2770.
C45H43IrN2O4·0.5H2O (888.08): calcd. C 61.62, H 5.06, N 3.19;
Ph), 6.02 (d, 3J = 8.0 Hz, 4 H, Ph), 3.85 (s, 12 H, OCH3) ppm.
HRMS: calcd. for C80H62Cl2193Ir2N4O4 [M – Cl]+ 1565.3876;
found 1565.3893.
found C 61.59, H 4.85, N 3.13.
ppy-4-CH2CH2C6H4OMe (1a-H2): Evaporation of the diethyl ether
solution gave a yellow oil identified as 1a-H2. 1H NMR (300 MHz,
CD2Cl2): δ = 8.57 (d, 3J = 4.9 Hz, 1 H, py6), 8.02 (m, 2 H, Ph
ortho), 7.57 (s, 1 H, py3), 7.47 (m, 3 H, Ph para and meta), 7.15 (d,
∧
[Ir(C N-ppy-4-CH=CHC6H4NEt2)2]2(µ-Cl)2 (3b): Yield 0.68 g
1
3
(94%). H NMR (500 MHz, CDCl3): δ = 9.10 (d, J = 6 Hz, 4 H,
py6), 7.88 (s, 4 H, py3), 7.58 (d, 4 H, py5), 7.44 (d, J = 8.6 Hz, 8
3
3
3
H, C6H4), 7.38 (d, J = 16 Hz, 4 H, =CH), 7.02 (d, J = 16 Hz, 4
3
3J = 8.5 Hz, 2 H, C6H4), 7.09 (d, J = 4.9 Hz, 1 H, py5), 6.87 (d,
H, =CH), 6.86 (d, 4 H, Ph), 6.77 (t, 3J = 7.0 Hz, 4 H, Ph), 6.68 (d,
3J = 8.5 Hz, 2 H, C6H4), 3.81 (s, 3 H, OCH3), 2.98 (m, 4 H, CH2)
3J = 8.6 Hz, 8 H, C6H4), 6.60 (t, 4 H, Ph), 6.14 (d, J = 7.0 Hz, 4
3
ppm. HRMS: calcd. for C19H19NO [M]+ 289.1467; found 289.1455.
H, Ph), 3.48 (q, 3J = 6.8 Hz, 16 H, CH2), 1.27 (t, 3J = 6.8 Hz,
24 H, CH3) ppm. HRMS: calcd. for C92H92Cl193Ir2N8 [M – Cl]+
1729.6396; found 1729.6435.
∧
Ir(C N-ppy-4-CH=CHC6H4OMe)2(acac) (4a): Red powder. Yield
0.092 g (93%). 1H NMR (300 MHz, CD2Cl2): δ = 8.45 (d, 3J =
6.0 Hz, 2 H, py6), 7.96 (d, 4J = 1.7 Hz, 2 H, py3), 7.68 (dd, 3J =
∧
[Ir(C N-ppy-4-CH=CHC6H5)2]2(µ-Cl)2 (3c): Yield 0.54 g (89%).
4
3
7.7 Hz, J = 1.1 Hz, 2 H, Ph3), 7.63 (d, J = 8.7 Hz, 4 H, C6H4),
1H NMR (500 MHz, CD2Cl2): δ = 9.25 (d, J = 6 Hz, 4 H, py6),
3
7.49 (d, 3J = 16.3 Hz, 2 H, =CH), 7.34 (dd, 3J = 6 Hz, 4J = 1.7 Hz,
8.06 (s, 4 H, py3), 7.71 (d, J = 7.5 Hz, 4 H, Ph), 7.54 (m, 12 H,
3
2 H, py5), 7.14 (d, J = 16.3 Hz, 2 H, =CH), 7.01 (d, J = 8.7 Hz,
3
3
=CH and Ph ortho), 7.36 (m, 3J = 16 Hz, 16 H, =CH and Ph meta
3
4
4 H, C6H4), 6.91 (td, J = 7.7 Hz, J = 1.1 Hz, 2 H, Ph4), 6.74 (td,
3J = 7.7 Hz, 4J = 1.1 Hz, 2 H, Ph5), 6.35 (dd, 3J = 7.7 Hz, 4J =
1.1 Hz, 2 H, Ph6), 5.34 (s, 1 H, CH), 3.90 (s, 6 H, OCH3), 1.86 (s,
6 H, CH3) ppm. 13C{1H} NMR (75 MHz, CD2Cl2): δ = 184.7
(CO), 167.9 (C2-py), 160.6 (C1-C6H4), 147.8 (C6-py), 147.5 (C1-Ph),
146.3 (C4-py), 145.2 (C2-Ph), 134.1 (=CH), 133.3 (C6-Ph), 128.7
(C4-C6H4, C3-C6H4, C5-Ph), 123.6 (C3-Ph), 122.8 (=CH), 120.7
(C4-Ph), 118.5 (C5-py), 115.4 (C3-py), 114.3 (C2-C6H4), 100.3 (CH),
55.4 (OCH3), 28.3 (CH3) ppm. HRMS: calcd. for C45H39193IrN2O4
[M]+ 864.2539; found 864.2528. In CD2Cl2 solution, partial isomer-
ization of the C=C double bond occurs, and the 1H NMR spec-
trum exhibits three isomers (E/E, E/Z, Z/Z); some signals are
and Ph para), 7.02 (d, J = 6 Hz, 4 H, py5), 6.90 (t, J = 7.5 Hz, 4
3
3
3
3
H, Ph), 6.69 (t, J = 6.8 Hz, 4 H, Ph), 6.09 (d, J = 8.0 Hz, 4 H,
Ph) ppm. HRMS: calcd. for C76H56Cl2193Ir2N4 [M]+ 1480.3130;
found 1480.3135.
∧
[Ir(C N-ppy-4-CH=CHC6H4NO2)2]2(µ-Cl)2 (3d): Cleavage with
∧
DMSO to form [Ir(C N-ppy-4-CH=CHC6H4NO2)(DMSO)(Cl)]
(3d-DMSO). Quantitative spectroscopic yield. 1H NMR (300 MHz,
[D6]DMSO): δ = 9.82 (d, 3J = 6.2 Hz, 1 H, py6), 9.50 (d, 3J =
6.2 Hz, 1 H, py6), 8.54 (s, 1 H, py3), 8.44 (s, 1 H, py3), 8.35 (d, J
3
= 7.8 Hz, 2 H, C6H4), 8.08–7.68 (m, 12 H, C6H4, =CH, py5, Ph3),
3
3
6.95 (t, J = 7.2 Hz, 1 H, Ph), 6.89 (t, J = 7.4 Hz, 1 H, Ph), 6.78
3
3
1
3
(t, 3J = 7.6 Hz, 1 H, Ph), 6.74 (t, J = 7.2 Hz, 1 H, Ph), 6.34 (d, J
clearly resolved. H NMR (300 MHz, CD2Cl2): δ = 8.45 (d, J =
= 7.7 Hz, 1 H, Ph6), 5.79 (d, J = 7.6 Hz, 1 H, Ph6) ppm.
6.0 Hz, py6, E/E), 8.43 (d, py6, E/Z), 8.34 (d, py6, E/Z), 8.33 (d,
3
2744
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Eur. J. Inorg. Chem. 2007, 2734–2747