H. Khan et al. / Polyhedron 39 (2012) 1–8
7
temperature, dissolved in dichloromethane and reacted with the
5.2.4. [Pd(bis(2-methoxyethyl)-dithiocarbamate)(PPh2-o-OMe-Ph)Cl]
(4)
desired dithiocarbamate in a 1:1 M ratio. The reaction mixture
was heated under reflux for 24 h. The resulting solution was dec-
anted off and the solvent was removed under reduced pressure
to form a golden yellow solid, which was dissolved in 30 mL of a
mixture of dichloromethane, n-hexane and diethyl ether (2:1:1)
and kept for recrystallization at room temperature in a 100 mL
conical flask. Golden yellow crystals of 1 and 2 were obtained,
but the other products were not crystalline under these conditions.
Quantities used were 0.99 g (4.0 mmol) of bis(2-methoxyethyl)-
dithiocarbamate and 3.04 g (4.0 mmol) Pd(PPh2-o-tolyl)2Cl2 in
25 mL of dichloromethane. Yield: 90% (0.30 g) of a golden yellow
solid. M.p. 175–176 °C. FTIR (powder, cmꢁ1): 3060, 2962, 1520,
1412, 1257, 995, 790, 701, 385, 322. 1H NMR (300 MHz, CDCl3) d:
7.40–7.33 (m, 7H, ArH), 7.32–7.25 (m, 6H, ArH), 7.15 (t, 1H, ArH,
3
3JH–H = 7.6 Hz), 3.72 (t, 2H, –CH2CH2, JH–H = 6.9 Hz), 3.70 (t, 2H, –
3
CH2CH2, JH–H = 6.9 Hz), 3.30 (s, 6H, –CH2OCH3), 3.24 (t, 2H, –
3
3
NCH2, JH–H = 6.3 Hz), 3.22 (t, 2H, –NCH2, JH–H = 6.3 Hz), 1.82 (s,
3H, Ar-OCH3). 13C{1H} NMR (75.47 MHz, CDCl3) d: 206.2 (1C, -
CSS), 159.8 (1C, Ar), 135.6 (2C, Ar), 134.2 (5C, Ar), 128.2 (7C, Ar),
123.0 (1C, Ar), 121.0 (1C, Ar), 111.2 (1C, Ar), 69.9 (1C, –CH2OCH3),
69.4 (1C, –CH2OCH3), 55.9 (1C, –NCH2), 55.2 (1C, –NCH2), 50.1 (1C,
–NCH2CH2), 49.8 (1C, –NCH2CH2). 31P NMR (80.98 MHz, CDCl3) d:
22.6. Anal. Calc. for C26H31ClNO3PPdS2: C, 48.60; H, 4.86; N, 2.18;
S, 9.98. Found: C, 48.56; H, 4.83; N, 2.16; S, 10.01%.
5.2.1. [Pd(dibutyldithiocarbamate)(PPh3)Cl] (1)
Quantities used were 0.28 g (4.0 mmol) of dibutyldithiocarba-
mate and 2.80 g (4.0 mmol) Pd(PPh3)2Cl2 in 25 mL of dichloro-
methane. Yield 80% (0.24 g) of golden yellow crystals. M.p.
171–172 °C. FT-IR (powder, cmꢁ1): 3072, 2925, 1526, 1093, 798,
691, 388, 320. 1H NMR (300 MHz, CDCl3) d: 7.73–7.66 (m, 9H,
3
ArH), 7.47–7.40 (m, 6H, ArH), 3.63 (t, 2H, –NCH2, JH–H = 7.5 Hz),
3.48 (t, 2H, –NCH2, 3JH–H = 7.5 Hz), 1.68–1.50 (m, 4H, –CH2CH2CH3),
3
1.38–1.23 (m, 4H, -CH2CH2CH3), 0.94 (t, 3H, –CH2CH3, JH–H
5.2.5. [Pd(dimethyldithiocarbamate)(PPh2Cl)Cl] (5)
3
= 7.2 Hz), 0.88 (t, 3H, –CH2CH3, JH–H = 7.2 Hz). 13C{1H} NMR
Quantities used were 0.48 g (4.0 mmol) of dimethyldithiocarba-
mate and 2.47 g (4.0 mmol) of Pd(PPh2Cl)2Cl2 in 25 mL of dichloro-
methane. Yield: 84% (0.17 g) of a golden yellow solid. M.p.
195–196 °C. FTIR (powder, cmꢁ1) 3053, 2962, 1534, 1433, 1096,
727, 689, 485, 383, 320. 1H NMR (300 MHz, CDCl3) d: 7.73–7.66
(m, 6H, ArH), 7.38–7.35 (m, 4H, ArH), 3.25 (s, 3H, –NCH3), 3.23 (s,
3H, –NCH3). 13C{1H} NMR (75.47 MHz, CDCl3) d: 208.5 (1C, –CSS),
131.3 (2C, Ar), 131.0 (4C, Ar), 128.1 (6C, Ar), 39.1 (1C, –NCH3),
39.0 (1C, –NCH3). 31P NMR (121.49 MHz, CDCl3) d: 84.0. Anal. Calc.
for C15H16Cl2NPPdS2: C, 37.32; H, 3.34; N, 2.90; S, 13.29. Found: C,
37.00; H, 3.33; N, 2.91; S, 13.25%.
(75.47 MHz, CDCl3) d: 206.2 (1C, –CSS), 134.5 (3C, Ar), 130.7 (6C,
Ar), 128.8 (6C, Ar), 128.7 (3C, Ar), 48.9 (1C, –NCH2), 48.8 (1C, –
NCH2), 29.1 (1C, –CH2CH2CH3), 29.0 (1C, –CH2CH2CH3), 20.0 (1C,
–CH2CH3), 19.8 (1C, –CH2CH3), 13.7 (1C, –CH3), 13.6 (1C, –CH3).
31P{1H} NMR (121.49 MHz, CDCl3) d: 26.4. Anal.
Calc. for
27H33ClNPPdS2: C, 53.29; H, 5.47; N, 2.30; S, 10.54. Found: C,
C
53.31; H, 5.48; N, 2.33; S, 10.51%.
5.2.2. [Pd(dibutyldithiocarbamate)(PPh2-p-tolyl)] (2)
Quantities used were 0.28 g (4.0 mmol) dibutyldithiocarbamate
and 2.91 g (4.0 mmol) Pd(PPh2-o-tolyl)2Cl2 in 25 mL of dichloro-
methane. Yield: 82% (0.28 g) of golden yellow crystals. M.p. 195–
196 °C. FTIR (powder, cmꢁ1): 3049, 2930, 1512, 1433, 1095, 804,
747, 694, 380, 315. 1H NMR (300 MHz, CDCl3) d: 7.74–7.58 (m,
8H, ArH), 7.44–7.32 (m, 4H, ArH), 7.28–7.19 (m, 2H, ArH), 3.64 (t,
5.3. Structural studies
Crystals of complexes 1 and 2 were obtained by dissolving the
product in a mixture of dichloromethane, n-hexane, and diethyl
ether (2:1:1 v/v), and dichloromethane, n-hexane and petroleum
ether (2:1:1 v/v), respectively. The solvents were slowly evapo-
rated at room temperature in an open atmosphere and golden yel-
low crystals were obtained. The block crystals were mounted on a
glass fibre using Paratone N hydrocarbon oil. The measurements
were made at 200(2) K on a Bruker APEX II area detector diffrac-
3
3
2H, –NCH2, JH–H = 7.8 Hz), 3.49 (t, 2H, –NCH2, JH–H = 7.8 Hz),
1.73 (s, 3H, –CH3(p-tol)), 1.66–1.53 (m, 4H, –CH2CH2CH3), 1.38–
3
1.23 (m, 4H, –CH2CH2CH3), 0.94 (t, 3H, –CH2CH3, JH–H = 7.5 Hz),
3
0.89 (t, 3H, –CH2CH3, JH–H = 7.2 Hz). 13C{1H} NMR (75.47 MHz,
CDCl3) d: 206.3 (1C, –CSS), 137.3 (1C, Ar), 135.1 (9C, Ar), 134.0,
128.4 (8C, Ar), 49.0 (1C, –NCH2), 48.8 (1C, –NCH2), 29.2 (1C, –
CH2CH2CH3), 29.1 (1C, –CH2CH2CH3), 20.0 (1C, –CH2CH3), 19.8
(1C, –CH2CH3), 13.7 (1C, –CH3), 13.6 (1C, –CH3). 31P{1H} NMR
(121.49 MHz, CDCl3) d: 22.9. Anal. Calc. for C28H35ClNPPdS2: C,
54.02; H, 5.67; N, 2.25; S, 10.30. Found: C, 54.08; H, 5.68; N,
2.27; S, 10.34%.
tometer equipped with graphite monochromated Mo Ka radiation.
The program used for retrieving cell parameters and data collec-
tion was APEX-2 [28]. The data were integrated using the program
SAINT [29] and were corrected for Lorentz and polarization effects.
The multiscan absorption corrections were performed using SADABS
[30]. The structures were solved and refined using SHELXS-97 and
SHELXL-97 (Sheldrick, 1997) [31] and all non-H atoms were refined
anisotropically, with the hydrogen atoms placed at idealized
positions.
5.2.3. [Pd(dipropyldithiocarbamate)(PPh2-t-butyl)Cl] (3)
Quantities used were 0.70 g (4.0 mmol) of dipropyldithiocarba-
mate and 2.65 g (4.0 mmol) of Pd(PPh2-t-butyl)2Cl2 in dichloro-
methane. Yield: 85% (0.27 g) of a golden yellow solid. M.p.
155–156 °C. FTIR (powder, cmꢁ1): 3051, 2959, 1512, 1432, 1246,
1095, 742, 693, 382, 316. 1H NMR (300 MHz, CDCl3) d: 7.50–7.46
5.4. Anti-tumor potato disc assay
For the assay of anti-tumour potato discs, the procedure of
Mclaughlin et al. was followed [32]. Agrobacterium tumefecien (At
10) was grown for 48 h in lauria broth medium containing rifampi-
cin (50 mg/ml). Red skinned potatoes were surface sterilized in a
0.1% mercuric chloride solution for 10 min and thoroughly washed
with autoclaved distilled water. Potato discs (5 mm ꢂ 8 mm) were
made with a borer and placed on agar (1.5%) plates (10 discs per
3
(m, 6H, ArH), 7.44–7.40 (m, 4H, ArH), 3.93 (t, 2H, –NCH2, JH–H
3
= 7.5 Hz), 2.99 (t, 2H, –NCH2, JH–H = 7.5 Hz), 1.88–1.77 (m, 2H, –
CH2CH3), 1.74–1.66 (m, 2H, –CH2CH3), 1.00 (s, 9H, –C(CH3)3), 0.94
3
3
(t, 3H, –CH2CH3, JH–H = 7.5 Hz), 0.88 (t, 3H, –CH2CH3, JH–H
= 7.5 Hz). 13C{1H} NMR (75.47 MHz, CDCl3) d: 206.5 (1C, –CSS),
134.9 (4C, Ar), 129.9 (2C, Ar), 127.6 (6C, Ar), 55.5 (1C, –NCH2),
47.9 (1C, –NCH2), 30.0 (1C, C(CH3)3), 27.8 (1C, C(CH3)3), 20.3 (1C,
–CH2CH3), 19.0 (1C, –CH2CH3), 11.4 (1C, –CH3), 11.3 (1C, –CH3).
31P{1H} NMR (121.49 MHz, CDCl3) d: 46.9. Anal. Calc. for
plate). Agrobacterium cultures (600 ll) mixed with 150 ll each of
10,000, 1000, 100, 10, and 1 ppm of the compounds inoculum (in
DMSO) were applied on the surface of each disc with the respective
concentrations mentioned. The petri plates were then kept at 28 °C
for 21 days. After 21 days, the discs were stained using Lugol’s
C23H33ClNPdS2: C, 52.17; H, 6.28; N, 2.65; S, 12.11. Found: C,
52.12; H, 6.26; N, 2.64; S, 12.16%.