Palladium(ii) and Platinum(ii) Complexes with Crown Ether Phosphane Ligands
FULL PAPER
Ph(Hortho)], 7.50 [m, 1 H, Ph(Hpara)], 7.43 [m, 2 H, Ph(Hmeta)], 7.21
[dd, JP = 12.5, JH6 = 1.7, 2 H, Ar*(H2)], 7.00 [ddd, JP = 12.1, JH5
(0.250 g, 0.342 mmol). The presence of 1 equiv. of MeOH in the
crystalline white solid is suggested by the elemental analyses and
= 8.2, 2 H, Ar*(H6)], 6.86 [dd, JP = 2.9, 2 H, Ar*(H5)], 4.13 (m, 4 confirmed by NMR spectra (resonances of the methanol are omit-
H, CH2 crown), 4.01 (m, 4 H, crown), 3.91 (m, 4 H, crown), 3.83
ted in the spectroscopic data below). C38.5H56BO12.5P (760.65, in-
(m, 4 H, crown), 3.75 (m, 4 H, crown), 3.74–3.67 (m, 12 H, crown), cludes 1/2 a molecule of methanol): calcd. C 60.79, H 7.42; found
1
3.66 (s, 8 H, crown) ppm. 13C{1H} NMR (CDCl3, 126 MHz): δ =
C 60.74, H 7.36. H NMR (CDCl3, 500 MHz): δ = 7.49 [m, JP =
151.82 [s, Ar*(C4)], 148.87 [d, JP = 14.5, Ar*(C3)], 132.92 [d, JP
12.4, Ph(Cortho)], 131.52 [d, JP = 2.6, Ph(Cpara)], 130.01 [d, JP
105.6, Ph(Cipso)], 128.55 [d, JP = 11.5, Ph(Cmeta)], 126.68 [d, JP
=
=
=
10.8, 2 H, Ph(Hortho)], 7.47 [m, 1 H, Ph(Hpara)], 7.38 [m, 2 H,
Ph(Hmeta)], 7.08 [dd, JP = 11.4, JH6 = 1.8, 2 H, Ar*(H2)], 7.00 [ddd,
JP = 8.6, JH5 = 8.4, 2 H, Ar*(H6)], 6.85 [dd, JP = 2.6, 2 H, Ar*(H5)],
4.15 (m, 4 H, CH2 crown), 4.05 (m, 4 H, crown), 3.91 (m, 4 H,
12.0, Ar*(C6)], 124.02 [d, JP = 106.9, Ar*(C1)], 117.52 [d, JP = 12.1,
Ar*(C2)], 113.03 [d, JP = 14.3, Ar*(C5)], 70.93, 70.83, 70.80, 70.67, crown), 3.84 (m, 4 H, crown), 3.75 (m, 4 H, crown), 3.74–3.67 (m,
70.65, 70.42, 69.45, 69.18, 68.89 (s, CH2 crown) ppm. 31P{1H}
NMR (CDCl3, 202 MHz): δ = 31.3 ppm.
12 H, crown), 3.66 (s, 8 H, crown), 1.5–0.6 (very broad, BH3) ppm.
13C{1H} NMR (CDCl3, 75 MHz): δ = 151.50 [s, Ar*(C4)], 148.98
[d, JP = 13.3, Ar*(C3)], 132.89 [d, JP = 9.6, Ph(Cortho)], 130.95 [d,
JP = 3.0, Ph(Cpara)], 130.11 [d, JP = 58.2, Ph(Cipso)], 128.60 [d, JP
Ar*Ph2P·BH3 (7): PAr*Ph2 (1; 0.11 g, 0.22 mmol) was dissolved in
THF (20 mL) and a 1.0 m solution of BH3·THF in THF (0.22 mL,
0.22 mmol) was added with a syringe. The mixture was stirred at
room temperature for 24 h. The solvent was subsequently removed
under vacuum to give a white solid. Pure borane complex 7
(0.097 g, 85%) was obtained after crystallization of the crude pro-
duct from a mixture of absolute ethanol and methanol (18:1) at
–25 °C. C28H36BO6P (510.38): calcd. C 65.89, H 7.11; found C
66.01, H 7.08. MS (ESI+): m/z = 534.0 (calcd. for MNa+: 533.2),
520.0 (calcd. for MNa+ – BH3: 519.2). 1H NMR (CDCl3,
300 MHz): δ = 7.52 [m, JP = 10.8, 4 H, Ph(Hortho)], 7.47 [m, 2 H,
Ph(Hpara)], 7.43 [m, 4 H, Ph(Hmeta)], 7.10 [dd, JP = 11.4, JH6 = 1.8,
1 H, Ar*(H2)], 7.05 [ddd, JP = 10.4, JH5 = 8.2, 1 H, Ar*(H6)], 6.87
[dd, JP = 2.4, 1 H, Ar*(H5)], 4.15 (m, 2 H, CH2 crown), 4.05 (m,
2 H, crown), 3.91 (m, 2 H, crown), 3.84 (m, 2 H, crown), 3.74 (m,
2 H, crown), 3.71 (m, 2 H, crown), 3.70 (m, 2 H, crown), 3.68 (m,
2 H, crown), 3.65 (s, 4 H, crown), 1.5–0.6 (very broad, BH3) ppm.
13C{1H} NMR (CDCl3, 126 MHz): δ = 151.64 [d, JP = 2.2,
Ar*(C4)], 148.98 [d, JP = 12.8, Ar*(C3)], 133.03 [d, JP = 9.5, Ph-
(Cortho)], 132.04 [d, JP = 2.2, Ph(Cpara)], 129.65 [d, JP = 57.8,
Ph(Cipso)], 128.67 [d, JP = 10.0, Ph(Cmeta)], 127.38 [d, JP = 9.5,
Ar*(C6)], 120.07 [d, JP = 62.3, Ar*(C1)], 118.21 [d, JP = 12.8,
Ar*(C2)], 113.28 [d, JP = 12.23, Ar*(C5)], 70.94, 70.89, 70.80, 70.71,
70.67, 69.45, 69.37, 69.17, 68.88 (s, CH2 crown) ppm. 31P{1H}
NMR (CDCl3, 202 MHz): δ = 21.5 ppm.
= 10.3, Ph(Cmeta)], 127.17 [d, JP = 8.9, Ar*(C6)], 120.57 [d, JP
=
62.7, Ar*(C1)], 117.97 [d, JP = 12.5, Ar*(C2)], 113.17 [d, JP = 12.5,
Ar*(C5)], 70.90, 70.82, 70.78, 70.69, 70.63, 70.41, 69.36, 69.12,
68.84 (s, CH2 crown) ppm. 31P{1H} NMR (CDCl3, 202 MHz): δ =
21.0 ppm.
Decomplexation of Phosphane–Borane Complex 7: This was carried
out as described below for complex 9.
Decomplexation of Phosphane–Borane Complex 8: Complex 8
(0.044 g, 0.065 mmol) and 1,4-diazabicyclo[2.2.2]octane (DABCO)
(0.0174, 0.16 mmol) were dissolved in THF (5 mL). The mixture
was refluxed at 85 °C for 5 h and then allowed to cool to room
temperature. The solvent was removed under reduced pressure and
complete decomplexation was evidenced by 1H NMR spectroscopy.
The excess of DABCO was completely eliminated under high vac-
uum at room temperature and the DABCO·BH3 formed in the re-
action was partially removed in this treatment. The final product
was found to be a mixture of phosphane 2 and DABCO·BH3 (1.6:1,
1H NMR).
Decomplexation of Phosphane–Borane Complex 9: Complex 9
(0.22 g, 0.30 mmol) and the DABCO ligand (0.040, 0.36 mmol)
were dissolved in toluene (20 mL). The mixture was stirred at 40 °C
for 4 h. The solvent was removed under reduced pressure and the
crude product was identified as a 1:1 mixture of phosphane 3 and
complex BH3·DABCO (1H NMR), showing that decomplexation
was complete. Phosphane 3 (0.20 g, 90%) could be purified by
crystallization of the crude mixture with ethanol at –25 °C.
Ar*2MeP·BH3 (8): The procedure described above for 7 was used
for the synthesis of borane complex 8 starting from the crude pro-
duct 2 (0.35 g, 0.52 mmol) and a 1.0 m solution of BH3·THF in
THF (0.52 mL, 0.52 mmol). In this case, the reaction time was re-
duced to 4 h, and the crude product was recrystallized three times
from a mixture of absolute ethanol and methanol (18:1) at –25 °C
to provide 0.21 g (60%) of an analytically pure solid which was
identified as 8. C33H52BO12P (682.55): calcd. C 58.07, H 7.68;
found C 58.30, H 7.63. MS (ESI+): m/z = 706.0 (calcd. for MNa+:
705.3). IR (KBr pellets): ν(BH) = 2371 s. 1H NMR (CDCl3,
500 MHz): δ = 7.19 [dd, JP = 12.3, JH6 = 1.9, 2 H, Ar*(H2)], 7.13
[ddd, JP = 12.0, JH5 = 8.0, 2 H, Ar*(H6)], 6.87 [dd, JP = 2.9, 2 H,
Ar*(H5)], 4.15 (m, 4 H, CH2 crown), 4.13 (m, 4 H, crown), 3.91
(m, 4 H, crown), 3.89 (m, 4 H, crown), 3.78 (m, 8 H, crown), 3.73
(m, 8 H, crown), 3.65 (s, 8 H, crown), 1.74 (d, JP = 10.3, 3 H, Me),
1.3–0.5 (very broad, BH3) ppm. 11B{1H} NMR (CDCl3, 160 MHz):
δ = –39 ppm. 13C{1H} NMR (CDCl3, 126 MHz): δ = 151.52 [s,
Ar*(C4)], 148.97 [d, JP = 13.3, Ar*(C3)], 125.52 [d, JP = 8.9,
Ar*(C6)], 122.20 [d, JP = 60.5, Ar*(C1)], 117.25 [d, JP = 11.8,
Ar*(C2)], 113.55 [d, JP = 13.3, Ar*(C5)], 70.91, 70.85, 70.77, 70.68,
69.50, 69.39, 68.94 (s, CH2 crown), 12.5 (d, JP = 41.3, Me) ppm.
31P{1H} NMR (CDCl3, 202 MHz): δ = 10.2 ppm.
[PtCl2(PAr*Ph2)2] (10): The procedure described below for 12 was
used for the synthesis of platinum complex 10 starting from phos-
phane
1 (0.067 g, 0.13 mmol) and [PtCl2(PhCN)2] (0.028 g,
0.059 mmol). Complex 10 was obtained as a pure white solid con-
taining only the cis isomer (0.062 g, 83%). C56H66Cl2O12P2Pt
(1259.07): calcd. C 53.42, H 5.28; found C 53.11, H 5.31. MS
(ESI+): m/z = 1281.0 (calcd. for MNa+: 1280.3). IR (Nujol): ν(Pt–
Cl) = 318, 292. 1H NMR (CDCl3, 500 MHz): δ = 7.44 [m, 8 H,
Ph(Hortho)], 7.28 [m, 4 H, Ph(Hpara)], 7.14 [m, 8 H, Ph(Hmeta)], 7.09
[m, JP = 10.5, JH6 = 2.0, 2 H, Ar*(H2)], 6.93 [m, JP Ϸ 8, 2 H,
Ar*(H6)], 6.59 [dd, JP = 2.2, JH5 = 8.3, 2 H, Ar*(H5)], 4.10 (m, 4
H, CH2 crown), 3.90 (m, 4 H, crown), 3.76 (m, 8 H, crown), 3.74
(m, 8 H, crown), 3.69 (m, 8 H, crown), 3.66 (s, 8 H, crown) ppm.
13C{1H} NMR (CDCl3, 75 MHz): δ = 151.07 [d, JP = 2.2, Ar*(C4)],
147.67 [pseudo t, JP virtual = 14.4, Ar*(C3)], 134.44 [pseudo t,
JP virtual = 9.6, Ph(Cortho)], 130.47 [s, Ph(Cpara)], 130.01 [pseudo dd,
Japparent = 68.0 and 2.4, Ph(Cipso)], 129.01 [pseudo t, JP virtual = 9.6,
Ar*(C6)], 127.66 [pseudo t, JP virtual = 11.6, Ph(Cmeta)], 120.09
[pseudo dd, Japparent = 68.0 and 1.6, Ar*(C1)], 120.39 [pseudo t, JP
= 12.6, Ar*(C2)], 112.03 [pseudo t, JP = 12.8, Ar*(C5)], 70.93,
70.90, 70.79, 70.69, 70.58, 69.32, 68.92, 68.79 (s, CH2 crown) ppm.
Ar*2PhP·BH3 (9): The procedure described above for 7 was used
for the synthesis of borane complex 9 (0.308 g, 90%) from 3
Eur. J. Inorg. Chem. 2005, 1468–1476
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1473