Ph2P(S)HNP(Se)Ph2]ϩ. 31P NMR (CD2Cl2–d6-acetone 1 : 4):
δ 57.2 (d, SPPh2, JPP = 12.4 Hz), 50.9 (d, SePPh2, JPP = 12.4 Hz,
JPSe = 770 Hz) 1H NMR (d6-acetone): δ 4.81 (s, 2 H, NH), 7.43,
7.82 (m, 40 H, C6H5) Anal. calculated for C48H42-
AgBrN2P4S2Se2ؒ0.25CH2Cl2: C, 48.02; H, 3.56; N, 2.32%.
Found: C, 48.20; H, 3.50; N, 1.77%. Solvent of crystallisation
fixed isotropic contributions (1), respectively. All C–H atoms
were calculated and allowed to ride on their parent atoms with
fixed isotropic contributions. In the crystal of compound 3, the
S and Se atoms were disordered and refined accordingly. The
crystal of compound 4 contained some additional solvent
which could not be identified unambiguously and which was
processed using the SQUEEZE procedure (PLATON).17c The
volume occupied by the solvent is 218.5 Å3, the number of
electrons per unit cell deduced by SQUEEZE is 10. Further
information on crystal data, data collection and structure
refinement are summarised in Table 1. Important interatomic
distances and angles are shown in the corresponding figure
captions.
1
was established by integration of the H NMR spectrum in
d6-dmso.
[{HN(Ph2PSe)(Ph2PS)-Se,S}AgBr]2 (3).
A crystallisation
experiment intended to provide crystals of 2 from a layered
mixture of acetone and pentane was found to yield single
crystals of complex 3 instead. C24H21AgBrP2NSSe requires:
C, 42.13; H, 3.09; N, 2.06%. Found: C, 42.33; H, 2.99, N, 1.93%.
CCDC reference numbers 165867–165869.
lographic data in CIF or other electronic format.
[{HN(Ph2PSe)(Ph2P)-Se,P}2Ag]Br (4). Silver bromide (20.3
mg, 0.108 mmol) and [Ph2P(Se)HNPPh2] (100.0 mg, 0.216
mmol) were stirred in acetone (30 mL) for 2 h. The solvent
volume was reduced to ca. 5 mL and diethyl ether (20 mL)
carefully added to precipitate the white product. This was
washed with diethyl ether (10 mL) and pentane (10 mL) and
dried. Yield: 69% (83 mg). MS (FAB) m/z = 1037, 54% [M]ϩ,
651, 14% [M Ϫ HN(Ph2P)2]ϩ, 572, 90% [M Ϫ HN(Ph2PSe)-
(Ph2P)]ϩ. 31P NMR (CD2Cl2–EtOH 1 : 5): δ 38.7 (dd, PPh2,
JPAgP = 376 Hz, JPNP = 80 Hz); 62.8 (d, SePPh2, JPNP = 80 Hz, JPSe
Synthesis and characterisation of complexes
Acetone solutions of [Ph2P(Se)HNP(E)Ph2] (E = Se, S, O
or lone pair) and AgBr were allowed to react at room temp-
erature to provide moderate to good yields of the com-
plexes [{HN(Ph2PSe)2-Se,SeЈ}2Ag]Br (1), [{HN(Ph2PSe)-
(Ph2PS)-Se,S}2Ag]Br (2) [{HN(Ph2PSe)(Ph2P)-Se,P}2Ag]Br (4)
and [{HN(Ph2PSe)(Ph2PO)-Se}2Ag]Br (5) (see Schemes 1–3).
1
not resolved) H NMR (d4-methanol): δ 3.61 (m, 2 H, NH),
7.30–7.68 (m, 40 H, C6H5). Anal. calculated for C48H42AgBr-
N2P4Se2: C, 51.64; H, 3.79; N, 2.51%. Found: C, 51.88; H, 3.78;
N, 2.25%.
[{HN(Ph2PSe)(Ph2PO)-Se}2Ag]Br (5). Silver bromide (19.6
mg, 0.104 mmol) and [Ph2P(Se)HNP(O)Ph2] (100.0 mg, 0.208
mmol) were stirred in acetone (30 mL) for 2 h. The solvent
volume was reduced to ca. 5 mL and pentane (20 mL) carefully
added to precipitate the white product. This was washed with
pentane (10 mL) and dried. Yield: 57% (68 mg). IR (KBr/
Nujol): 1181 [ν(PO)] cmϪ1. MS (FAB) m/z = 1070, 6% [M]ϩ, 589,
4% [M Ϫ ligand]ϩ. 31P NMR (CD2Cl2): δ 21.8 (d, OPPh2, JPP
=
Scheme 1 Preparation of the complexes 1 and 2 and the loss of
[Ph2P(Se)HNP(S)Ph2] ligand to form 3.
20.0 Hz), 51.9 (d, SePPh2, JPP = 20.1 Hz, JPSe not resolved).
1H NMR (CD2Cl2): δ 4.96 (s, 2 H, NH), 7.34–7.49, 7.67, 7.93
(m, 40 H, C6H5). Anal. calculated for C48H42AgBrN2O2P4Se2: C,
50.20; H, 3.69; N, 2.44%. Found: C, 50.50; H, 3.93; N, 2.08%.
[{Ph2P(Se)CH2CH2AsPh2}2Ag]Br (6). Silver bromide (19.6
mg, 0.104 mmol) and [Ph2P(Se)CH2CH2AsPh2] (100 mg,
0.208 mmol) were stirred in acetone (30 mL) for 2 h. The
solvent volume was reduced to ca. 5 mL and pentane (20 mL)
carefully added to precipitate the white product. This was
washed with pentane (10 mL) and dried. Yield: 30% (38 mg).
MS (FAB) m/z = 1154, 10% [M]ϩ, 629, 100% [M Ϫ Ph2P(Se)-
CH2CH2AsPh2]ϩ. 31P NMR (d6-acetone): δ 39.1 (s, SePPh2,
Scheme 2 Preparation of complex 4.
1
JPSe = 716 Hz). H NMR (d6-acetone): δ 3.25 (m, 2 H, CH2),
7.33, 7.47, 7.86 (m, 40 H, C6H5). Anal. calculated for
C52H48AgAs2BrP2Se2ؒ2CHCl3: C, 44.15; H, 3.43%. Found:
C, 43.52; H, 3.10%. The complex was recrystallised from
a chloroform–pentane mixture and yielded the chloroform
bis-solvate as shown by integration of the 1H NMR spectrum.
Scheme 3 Preparation of complex 5.
The composition of the complexes 1, 2, 4 and 5 was elucid-
ated from microanalysis and FAB mass spectrometric data. The
latter technique provided m/z peaks for the molecular ions in
each case along with peaks corresponding to the loss of an
aminodiphosphine chalcogenide ligand ([M Ϫ L]ϩ). The frag-
mentations observed correlate well with the simulated isotope
patterns. 31P NMR spectroscopy also proved an invaluable tool
in the determination of ligand geometry at the metal centre. In
each complex, the phosphorus atom bearing selenium gave rise
to a resonance at ca. 51 ppm with 31P–77Se coupling in the range
745–770 Hz. A large coupling between the two Ag-bound
phosphorus atoms of 376 Hz (AAЈBBЈ spin system) is observed
X-Ray crystallography
Specimens of suitable quality and size of compounds 1, 3, and
4 were mounted on the ends of quartz fibres in F06206R oil
and used for intensity data collection on a Nonius DIP2020
diffractometer, employing graphite-monochromated Mo-Kα
radiation. The structures were solved by a combination of dir-
ect methods (SHELXS-97)17a and difference-Fourier syntheses
and refined by full matrix least-squares calculations on F 2
(SHELXL-97).17b The thermal motion was treated anisotropic-
ally for all non-hydrogen atoms. All N–H atoms were located
and included into the refinement isotropically (3, 4) and with
3648
J. Chem. Soc., Dalton Trans., 2001, 3647–3651