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M. Muthu Tamizh et al. / Journal of Organometallic Chemistry 700 (2012) 194e201
2.4.1. [Ru(L1)(CO)(PPh3)2] (1)
25 ꢁC):
d
¼ 108.77, 115.33, 120.14, 122.80, 124.28, 125.54, 127.44,
1 was prepared from [RuHCl(CO)(PPh3)3] (250 mg; 0.262 mmol)
and H2L1 (60 mg; 0.262 mmol). Yield: 141 mg (61%). Decomposi-
tion temperature 230 ꢁC. Anal. Calc for C50H39NO2P2RuS: C, 68.17;
H, 4.46; N, 1.59; S, 3.63. Found: C, 68.02; H, 4.35; N, 1.39; S, 3.34%.
UVeVis (CH2Cl2), lmax/nm (ε/dm3molꢀ1cmꢀ1): 229 (52615), 258
127.48, 127.52, 129.54, 129.70, 131.06, 131.22, 131.39, 134.29, 134.33,
134.38, 135.96, 141.33, 141.39, 147.34, 151.71, 164.07, 206.42. 1P{1H}
NMR (202.46 MHz, CDCl3, 25 ꢁC):
d
¼ 29.52 (s).
2.4.5. [Ru(L5)(CO)(PPh3)2] (5)
(24623), 330 (6435), 373 (3031), 475 (3188). IR (KBr disk), cmꢀ1
:
5 was prepared from [RuHCl(CO)(PPh3)3] (250 mg; 0.262 mmol)
and H2L5 (73 mg; 0.262 mmol). Yield: 142 mg (58%). Decomposi-
tion temperature 245 ꢁC. Anal. Calc. for C54H41NO2P2RuS: C, 69.67;
H, 4.44; N, 1.50; S, 3.44. Found: C, 69.40; H, 4.21; N, 1.29; S, 3.27%.
UVeVis (CH2Cl2) lmax/nm (ε/dm3molꢀ1cmꢀ1): 230 (52172), 259
(15122), 271 (24836), 330 (10557), 380 (4041), 462 (3996), 494
n
(C^O) 1925,
n
(C]N) 1601,
n
(CeO) 1331,
n
(CeS) 741, bands due to
PPh3 1433, 1090, 693. 1H NMR (500 MHz, CDCl3, 25 ꢁC):
d
¼ 6.15 (t,
J ¼ 7.09 Hz, 1H), 6.47 (d, J ¼ 6.94 Hz, 1H), 6.57 (d, J ¼ 8.20 Hz, 2H),
6.65 (t, J ¼ 7.09 Hz, 1H), 6.75 (d, J ¼ 8.20 Hz, 1H), 6.85 (t, J ¼ 6.94 Hz,
1H), 7.06e7.17 (m, 13H), 7.18e7.24 (m, 6H), 7.28e7.42 (m, 12H), 7.55
(bs, 1H). 13C{1H} NMR (125.76 MHz, CDCl3, 25 ꢁC):
d
¼ 112.39,
(5507). IR (KBr disk), cmꢀ1
1319,
(CeS) 741, bands due to PPh3 1433, 1091, 693. 1H NMR
(500 MHz, CDCl3, 25 ꢁC):
: n(C^O) 1933,n(C]N) 1614, n(CeO)
115.38, 119.92, 119.97, 123.87, 123.96, 127.35, 127.39, 127.43, 128.46,
129.40, 129.61, 131.40, 131.56, 131.73, 132.03, 134.38, 134.43, 134.47,
135.13, 141.52, 147.45, 153.32, 165.47, 205.55. 1P{1H} NMR
n
d
¼ 6.54 (t, J ¼ 7.57 Hz, 1H), 6.63 (t,
J ¼ 8.20 Hz, 1H), 6.66 (d, J ¼ 9.14 Hz, 1H), 6.74 (d, J ¼ 8.20 Hz, 1H),
7.05e7.12 (m, 14H), 7.15e7.20 (m, 6H), 7.22 (d, J ¼ 9.14 Hz, 1H) 7.29
(t, J ¼ 8.35 Hz, 1H), 7.32e7.40 (m, 13H), 7.45 (dd, J ¼ 7.88, 0.95 Hz,
1H), 8.64 (bs, 1H). 13C{1H} NMR (125.76 MHz, CDCl3, 25 ꢁC):
(202.46 MHz, CDCl3, 25 ꢁC):
d
¼ 29.50 (s).
2.4.2. [Ru(L2)(CO)(PPh3)2] (2)
2 was prepared from [RuHCl(CO)(PPh3)3] (250 mg; 0.262 mmol)
and H2L2 (68 mg; 0. 0.262 mmol). Yield: 115 mg (48%). Decompo-
sition temperature 234 ꢁC. Anal. Calc. for C51H41NO3P2RuS: C, 67.24;
H, 4.54; N, 1.54; S, 3.52. Found: C, 67.10; H, 4.27; N, 1.21; S, 3.28%.
UVeVis (CH2Cl2) lmax/nm (ε/dm3molꢀ1cmꢀ1): 229 (56720), 258
d
¼ 109.82, 115.50, 119.12, 120.29, 121.03, 123.37, 126.24, 126.42,
126.92, 127.31, 127.39, 127.46, 128.14, 128.23, 128.45, 128.56, 128.62,
128.72, 129.05, 129.39, 129.49, 129.82, 131.26, 131.60, 131.94, 132.42,
133.59, 133.90, 134.28, 134.37, 134.46, 135.38, 140.00, 147.03, 147.49,
147.65, 166.06, 205.17. 1P{1H} NMR (202.46 MHz, CDCl3, 25 ꢁC):
(31581), 306 (13288), 377 (4002), 514 (3992). IR (KBr disk), cmꢀ1
:
d
¼ 29.58 (s).
n
(C^O) 1919,
n
(C]N) 1629,
n
(CeO) 1316,
n
(CeS) 741, bands due to
¼ 3.64 (s,
PPh3 1434, 1092, 692. 1H NMR (500 MHz, CDCl3, 25 ꢁC)
d
2.5. Catalytic oxidation of alcohols
3H), 5.94 (d, J ¼ 3.20 Hz, 1H), 6.53 (d, J ¼ 9.16 Hz, 1H), 6.58 (bs, 1H),
6.63 (dd, J ¼ 9.16, 3.20 Hz, 1H), 6.68 (t, J ¼ 7.10 Hz, 1H), 6.78 (d,
J ¼ 8.24 Hz, 1H), 7.07e7.19 (m, 13H), 7.21e7.27 (m, 6H), 7.34e7.42
(m, 12H), 7.51 (bs, 1H). 13C{1H} NMR (125.76 MHz, CDCl3, 25 ꢁC):
To a solution of alcohol (1 mmol) in dichloromethane (20 mL),
ruthenium(II) complex (1 mol%) and NMO (351 mg; 3 mmol) were
added. The mixture was stirred at 27 ꢁC for 12 h. Then the solution
was concentrated and the alcohol and aldehyde/ketone were ob-
tained by passing the solution through a short silica gel column
(hexane/ethyl acetate). The extract was then analyzed by GC.
d
¼ 56.11, 114.86, 115.33, 118.22, 120.00, 123.02, 123.78, 124.62,
127.37, 128.46, 128.52, 128.71, 129.39, 129.65, 131.45, 131.61,
131.78, 133.67, 133.82, 134.43, 134.47, 142.89, 147.40, 147.80, 152.48,
153.67, 161.34, 205.65. 1P{1H} NMR (202.46 MHz, CDCl3, 25 ꢁC):
d
¼ 29.41 (s).
3. Results and discussion
2.4.3. [Ru(L3)(CO)(PPh3)2] (3)
The reaction between ONS donor ligands (H2L) and [RuHCl(-
CO)(PPh3)3] afforded new ruthenium(II) complexes of composition
[Ru(L)(CO)(PPh3)2] (L ¼ dianionic ONS donor Schiff base ligand). All
the complexes are pink in color. They are stable under ambient
conditions and soluble in CH2Cl2, CH3CN, C6H6, DMSO, DMF and
C2H5OH. The analytical data for these complexes confirm the above
molecular formula. During complexation, it has been observed that
the Schiff base behaves as a bifunctional tridentate ligand by
substituting one triphenylphosphine, one hydride and one chloride
from the starting complex (Scheme 1).
3 was prepared from [RuHCl(CO)(PPh3)3] (250 mg; 0.262 mmol)
and H2L3 (69 mg; 0.262 mmol). Yield: 127 mg (53%). Decomposi-
tion temperature: 246 ꢁC. Anal. Calc. for C50H38ClNO2P2RuS: C,
65.61; H, 4.18; N, 1.53; S, 3.50. Found C, 65.43; H, 4.01; N, 1.28; S,
3.38%. UVeVis (CH2Cl2) lmax/nm (ε/dm3molꢀ1cmꢀ1): 231 (42822),
259 (16127), 269 (24574), 336 (6441), 371 (3847), 486 (4943). IR
(KBr disk), cmꢀ1
741, bands due to PPh3 1433, 1092, 693. 1H NMR (500 MHz, CDCl3,
25 ꢁC):
: n(C^O) 1925, n(C]N) 1597, n(CeO) 1319, n(CeS)
d
¼ 6.47 (d, J ¼ 2.75 Hz, 1H), 6.52 (d, J ¼ 9.16 Hz, 1H), 6.59 (t,
J ¼ 7.32 Hz, 1H), 6.69 (t, J ¼ 7.10 Hz, 1H), 6.75e6.81 (m, 2H),
7.08e7.13 (m, 1H), 7.14e7.20 (m, 12H), 7.23e7.28 (m, 6H), 7.32e7.39
(m, 12H), 7.52 (bs, 1H). 1P{1H} NMR (202.46 MHz, CDCl3, 25 ꢁC):
3.1. Spectral characterization
d
¼ 29.50 (s).
All the new ruthenium complexes are diamagnetic (meff ¼ 0),
indicating the presence of ruthenium in þ2 oxidation state in all the
complexes. The electronic spectra of all the complexes in
dichloromethane showed five to seven bands in the region
2.4.4. [Ru(L4)(CO)(PPh3)2] (4)
4 was prepared from [RuHCl(CO)(PPh3)3] (250 mg; 0.262 mmol)
and H2L4 (81 mg; 0.262 mmol). Yield: 159 mg (63%). Decomposi-
tion temperature 239 ꢁC. Anal. Calc. for C50H38BrNO2P2RuS: C,
62.57; H, 3.99; N, 1.46; S, 3.34. Found : C, 62.28; H, 3.71; N, 1.24; S,
3.10%. UVeVis (CH2Cl2) lmax/nm (ε/dm3molꢀ1cmꢀ1): 230 (39922),
259 (16390), 270 (25829), 295 (14840), 370 (4298), 486 (5270). IR
1
229e514 nm (Fig. 2). The ground state of ruthenium(II) is A1g
arising from t26g configuration in an octahedral environment. The
3
excited states corresponding to the t25geg1 configuration are 3T1g T2g
,
1T1g and T2g. Hence, four bands corresponding to the transitions
1
1A1g/3T1g 1A1g/3T2g 1A1g/1T1g and 1A1g/1T2g are possible in
, ,
(KBr disk), cmꢀ1
741, bands due to PPh3 1433, 1091, 693. 1H NMR (500 MHz, CDCl3,
25 ꢁC):
J ¼ 7.10 Hz, 1H), 6.74 (d, J ¼ 8.24 Hz, 1H), 6.86 (dd, J ¼ 8.93, 2.52 Hz,
1H), 7.09 (d, J ¼ 7.78 Hz, 1H), 7.11e7.19 (m, 12H), 7.20e7.28 (m, 6H),
7.29e7.38 (m, 12H), 7.49 (bs, 1H). 13C{1H} NMR (125.76 MHz, CDCl3,
:
n
(C^O) 1927
n(C]N) 1590,
n
(CeO) 1319,
n
(CeS)
the order of increasing energy. The bands appearing in the region
229e336 nm have been assigned to intraligand transitions [35].
The bands due to charge transfer transitions arising from the metal
d
¼ 6.45 (d, J ¼ 8.70 Hz, 1H), 6.53e6.61 (m, 2H), 6.66 (t,
t2g level to the unfilled p* molecular orbital of the ligand appeared
around 350e405 nm. The bands around 430e597 nm have been
assigned to the 1A1g/1T1g transition. The nature of electronic