[Ethylene-1,2-bis(diphenylphosphine)-P,P′]dinitratoplatinum(II) and cis-bis[(diphenylphosphinomethyl)-diphenylphosphine oxide-O,P]-platinum(II) dinitrate dihydrate

Article abstract of DOI:10.1107/S0108270100017273

On [Pt(dppe)(NO₃)₂], where dppe is ethylene-1,2-bis(diphenyl-phosphine) (C₂₆H₂₄P₂), the Pt atom is coordinated by the two P atoms and by two O atoms of the two nitrate ions. The molecule has a distorted square-planar geometry, with one of the nitrate groups directed on each side of the plane. The cation in cis-[Pt(dppmO-O,P)₂](NO₃)₂· 2H₂O, where dppmO is bis(diphenylphosphinomethyl)diphenylphosphine oxide (C₂₅H₂₂OP₂), comprises two five-membered chelate rings, each dppmO ligand being coordinated to platinum through one P atom and the O atom. The larger P-Pt-P angle of 102.25 (4)° is due to steric interactions between the two phenyl groups on each P atom.

Full text of DOI:10.1107/S0108270100017273

metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
1987), although the dppmO ligand was reported to be formed
in only low yield by the above method. The solid-state struc-
ture of [Pd(dppeO-O,P)2](BF4)2 has been reported recently
by Coyle et al. (1998). We obtained cis-[bis(diphenylphos-
phinomethyl)diphenylphosphine oxide-O,P]platinum(II) di-
nitrate dihydrate, cis-[Pt{Ph2PCH2P(O)PPh2}2](NO3)2Á2H2O,
(II), as an unexpected by-product of the reaction between
[PtCl2(dppm)] and silver nitrate in air.
ISSN 0108-2701
[Ethylene-1,2-bis(diphenylphos-
phine)-P,P0]dinitratoplatinum(II) and
cis-bis[(diphenylphosphinomethyl)-
diphenylphosphine oxide-O,P]-
platinum(II) dinitrate dihydrate
Malcolm J. Arendse, Gordon K. Anderson and Nigam P.
Rath*
The molecular structure of (I) is shown in Fig. 1. The
coordination geometry around the Pt atom is distorted square
planar, with P1ÐPtÐP2, O1ÐPtÐP1, O4ÐPtÐP2 and O1Ð
PtÐO4 angles of 85.85 (8), 90.82 (17), 98.15 (17) and 85.4 (2)ꢀ,
respectively. The PtÐOÐN angles are 113.5 (5) and
116.2 (5)ꢀ, and the NO2 groups lie on opposite sides of the
PtO2P2 plane. This feature was also observed in the structure
of cis-[Pt(NO3)2(PMe3)2] (Suzuki et al., 1993). The PtÐP
Department of Chemistry, University of Missouri ± St Louis, 8001 Natural Bridge
Road, St Louis, MO 63121, USA
Correspondence e-mail: nigam_rath@umsl.edu
Received 19 June 2000
Accepted 14 November 2000
Ê
distances of 2.215 (2) and 2.220 (2) A, and the PtÐO distances
In [Pt(dppe)(NO3)2], where dppe is ethylene-1,2-bis(diphenyl-
phosphine) (C26H24P2), the Pt atom is coordinated by the two
P atoms and by two O atoms of the two nitrate ions. The
molecule has a distorted square-planar geometry, with one of
the nitrate groups directed on each side of the plane. The
cation in cis-[Pt(dppmO-O,P)2](NO3)2Á2H2O, where dppmO
is bis(diphenylphosphinomethyl)diphenylphosphine oxide
(C25H22OP2), comprises two ®ve-membered chelate rings,
each dppmO ligand being coordinated to platinum through
one P atom and the O atom. The larger PÐPtÐP angle of
102.25 (4)ꢀ is due to steric interactions between the two phenyl
groups on each P atom.
Ê
of 2.111 (5) and 2.115 (5) A, are similar to the corresponding
distances in cis-[Pt(NO3)2(PMe3)2].
The molecular structure of the cation in (II) is bidentate
(Fig. 2), coordinating through one P atom and the O atom of
the phosphine oxide to form two ®ve-membered chelate rings.
Ê
The PtÐO distances are 2.089 (2) and 2.094 (2) A, and the
Ê
PtÐP distances are 2.2168 (10) and 2.2178 (10) A. These PtÐ
O and PtÐP bond lengths are similar to the values of
2.108 (10) A and 2.213 (4) A, respectively, found in cis-
[Pt{Ph2PNHP(O)Ph2-O,P}2](BF4)2 (Bhattacharyya et al.,
1996). The cation in the latter complex is analogous to that in
(II), since it is also composed of two ®ve-membered chelate
Ê
Ê
Comment
The dinitratoplatinum(II) complexes [Pt(NO3)2(P±P)] [P±P is
dppm, Ph2PCH2PPh2, or dppe, Ph2P(CH2)2PPh2] are useful
intermediates in the synthesis of a wide variety of diphos-
phine±platinum complexes, since the weakly coordinated
nitrates can be easily replaced by other ligands. They can be
isolated or they may be generated in situ and used in further
reactions without isolation (De Priest et al., 1997). We
prepared [ethylene-1,2-bis(diphenylphosphine)-P,P0]dinitra-
toplatinum(II), [Pt(NO3)2(dppe)], (I), as a precursor to the
corresponding ascorbate complex by the reaction of
[PtCl2(dppe)] with silver nitrate in acetone solution (Arendse
et al., 1999). The only structure of a related platinum complex
in the literature is that of cis-[Pt(NO3)2(PMe3)2] (Suzuki et al.,
1993).
Mixed phosphine±phosphine oxide ligands have been
prepared by the reaction of Ph2P(CH2)nPPh2 with benzyl
bromide, followed by aqueous NaOH (Abatjoglou & Kapicek,
1981). Palladium and platinum complexes of the type [M{Ph2-
P(CH2)nP(O)Ph2-O,P}2]2+ have been reported (Higgins et al.,
Figure 1
A view of (I) showing the labelling of the non-H atoms. Displacement
ellipsoids are shown at the 50% probability level and H atoms are drawn
as small circles of arbitrary radii.
ꢁ
Acta Cryst. (2001). C57, 237±239
# 2001 International Union of Crystallography
Printed in Great Britain ± all rights reserved 237

metal-organic compounds
Compound (I)
rings. The Ph2PNHP(O)Ph2 ligand is also isoelectronic with
dppmO. In the present case, the coordination geometry about
the Pt atom is distorted square planar. The O1ÐPtÐO2, O2Ð
PtÐP3, O1ÐPtÐP2 and P2ÐPtÐP3 angles are 87.54 (10),
86.10 (7), 84.09 (7) and 102.25 (4)ꢀ, respectively, giving an
angle sum of 359.98ꢀ around the metal. The larger PÐPtÐP
angle is due to the greater steric requirements of the phenyl
groups on the two P atoms that lie cis to each other. The PÐ
PtÐP angle in (II) is larger than that of 98.5 (2)ꢀ found in cis-
[Pt{Ph2PNHP(O)Ph2-O,P}2]2+ (Bhattacharyya et al., 1996); it
is closer to the values of 103.2 (1) and 103.72 (9)ꢀ in the
neutral complexes cis-[Pt{Ph2PNP(O)Ph2-O,P}2] (Bhatta-
charyya et al., 1996) and cis-[Pt{Ph2PCH2C(O)(CF3)2-O,P}2]
(Montgomery et al., 1987).
Crystal data
3
[Pt(C26H24P2)(NO3)2]
Mr = 717.50
Monoclinic, Cc
Dx = 1.820 Mg m
Mo Kꢂ radiation
Cell parameters from 8192
re¯ections
Ê
Ê
a = 10.4971 (1) A
b = 15.5281 (2) A
ꢃ = 2±26ꢀ
ꢄ = 5.53 mm
T = 223 (2) K
1
Ê
c = 16.3930 (2) A
ꢁ = 101.51 (1)ꢀ
V = 2618.36 (5) A
Z = 4
3
Ê
Plate, colourless
0.30 Â 0.20 Â 0.04 mm
Data collection
Bruker CCD area-detector diffract-
ometer
' and ! scans
Absorption correction: empirical
(SADABS; Blessing, 1995)
Tmin = 0.28, Tmax = 0.80
25 459 measured re¯ections
2576 independent re¯ections (plus
2561 Friedel-related re¯ections)
4304 re¯ections with I > 2ꢅ(I)
Rint = 0.10
ꢃmax = 26ꢀ
h = 12 ! 12
k = 19 ! 19
l = 20 ! 20
Intensity decay: <2%
Re®nement
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.039
wR(F2) = 0.069
S = 1.03
5137 re¯ections
w = 1/[ꢅ2(Fo2) + (0.0148P)2]
where P = (Fo2 + 2Fc2)/3
(Á/ꢅ)max < 0.001
3
Ê
Áꢆmax = 1.31 e A
3
Ê
0.59 e A
Áꢆmin
=
334 parameters
H-atom parameters constrained
Absolute structure: Flack (1983)
Flack parameter = 0.024 (8)
Table 1
Selected geometric parameters (A, ) for (I).
ꢀ
Ê
PtÐO4
PtÐO1
PtÐP1
PtÐP2
O1ÐN1
2.111 (5)
2.115 (5)
2.215 (2)
2.220 (2)
1.261 (8)
O2ÐN1
O3ÐN1
O4ÐN2
O5ÐN2
O6ÐN2
1.227 (8)
1.236 (8)
1.277 (9)
1.222 (9)
1.194 (9)
O4ÐPtÐO1
O1ÐPtÐP1
O4ÐPtÐP2
P1ÐPtÐP2
N1ÐO1ÐPt
N2ÐO4ÐPt
85.4 (2)
90.82 (17)
98.15 (17)
85.85 (8)
116.2 (5)
113.5 (5)
O2ÐN1ÐO3
O2ÐN1ÐO1
O3ÐN1ÐO1
O6ÐN2ÐO5
O6ÐN2ÐO4
O5ÐN2ÐO4
122.2 (8)
120.9 (7)
116.8 (7)
121.6 (9)
121.2 (8)
117.3 (8)
Figure 2
A view of the cation of (II) showing the labelling of the non-H atoms.
Displacement ellipsoids are shown at the 50% probability level and H
atoms are drawn as small circles of arbitrary radii.
Experimental
Compound (II)
Compound (I) was synthesized from [PtCl2(dppe)] (Anderson et al.,
1983) by halide abstraction with silver nitrate. Silver nitrate (0.34 g,
2.0 mmol) in water (5 ml) was added to an acetone solution (40 ml) of
[PtCl2(dppe)] (0.66 g, 1.0 mmol). The mixture was stirred for 24 h in
the dark at room temperature, and the precipitate of AgCl was
collected by ®ltration through Celite. The ®ltrate was evaporated
under reduced pressure and the products were obtained as a yellow
powder (yield 0.40 g, 56%). Crystals of (I) suitable for X-ray
diffraction were obtained by slow evaporation from a CDCl3 solution.
Analysis calculated for C26H24N2O6P2Pt: C 43.51, H 3.35, N 3.91%;
Crystal data
3
[Pt(C25H22OP2)2](NO3)2Á2H2O
Dx = 1.590 Mg m
Mo Kꢂ radiation
Mr = 1155.87
Monoclinic, P21/n
Cell parameters from 8192
re¯ections
Ê
Ê
a = 12.9843 (2) A
b = 16.3998 (2) A
Ê
c = 22.6979 (3) A
ꢁ = 92.81 (1)ꢀ
V = 4827.47 (11) A
Z = 4
ꢃ = 2.2±26.4ꢀ
1
ꢄ = 3.10 mm
T = 213 (2) K
3
Ê
Irregular, light yellow
0.36 Â 0.28 Â 0.22 mm
found: C 43.64, H 3.31, N 3.81%; 31P NMR (CDCl3): ꢀP 33.0 (1JPt,P
=
Data collection
3940 Hz). Compound (II) was prepared as follows: the reaction of
[PtCl2(dppm)] (1.30 g, 2 mmol) with 2 equivalents of silver nitrate
(0.68 g, 4.0 mmol) in acetone (100 ml) in the presence of air produced
a 4:1 mixture of [Pt(NO3)2(dppm)] and cis-[Pt(dppmO-O,P)2]2+, as
determined by 31P NMR spectroscopy [ꢀ 4.6 (s, 1JPt,P = 3810 Hz), 67.0
(br)]. On standing, crystals of (II) suitable for X-ray diffraction
analysis were obtained.
Bruker CCD area-detector diffract-
ometer
' and ! scans
Absorption correction: empirical
(SADABS; Blessing, 1995)
Tmin = 0.37, Tmax = 0.51
80 352 measured re¯ections
9898 independent re¯ections
7985 re¯ections with I > 2ꢅ(I)
Rint = 0.06
ꢃmax = 26.46ꢀ
h = 16 ! 16
k = 20 ! 20
l = 28 ! 28
Intensity decay: <2%
ꢁ
238 Malcolm J. Arendse et al.
[Pt(C26H24P2)(NO3)2] and [Pt(C25H22OP2)2](NO3)2Á2H2O
Acta Cryst. (2001). C57, 237±239

metal-organic compounds
Re®nement
SHELXTL-Plus (Sheldrick, 1999); program(s) used to re®ne struc-
ture: SHELXTL-Plus. For compounds (I) and (II), molecular
graphics: SHELXTL-Plus; software used to prepare material for
publication: SHELXTL-Plus.
Re®nement on F2
R[F2 > 2ꢅ(F2)] = 0.031
wR(F2) = 0.069
S = 1.09
9898 re¯ections
w = 1/[ꢅ2(Fo2) + (0.0237P)2
+ 8.7121P]
where P = (Fo2 + 2Fc2)/3
(Á/ꢅ)max = 0.001
3
Ê
Áꢆmax = 0.75 e A
3
Ê
0.59 e A
This work was supported through a grant from the National
Science Foundation (grant No. CHE-9508228) and a Univer-
sity of Missouri ± St Louis Research Award. Thanks are
expressed to the National Science Foundation for a grant to
purchase the X-ray diffraction instrumentation.
604 parameters
H-atom parameters constrained
Áꢆmin
=
Table 2
Selected geometric parameters (A, ) for (II).
ꢀ
Ê
PtÐO2
PtÐO1
PtÐP3
PtÐP2
P1ÐO1
2.089 (2)
2.094 (2)
2.2168 (10)
2.2178 (10)
1.525 (3)
P1ÐC1
P2ÐC1
P4ÐO2
P4ÐC2
P3ÐC2
1.804 (4)
1.837 (4)
1.520 (3)
1.806 (4)
1.844 (4)
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: BK1556). Services for accessing these data are
described at the back of the journal.
O2ÐPtÐO1
O2ÐPtÐP3
O1ÐPtÐP3
O2ÐPtÐP2
O1ÐPtÐP2
87.54 (10)
86.10 (7)
173.52 (7)
171.61 (7)
84.09 (7)
P3ÐPtÐP2
102.25 (4)
106.89 (16)
101.45 (13)
121.61 (14)
106.00 (19)
References
O1ÐP1ÐC1
C1ÐP2ÐPt
P1ÐO1ÐPt
P1ÐC1ÐP2
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Ê
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Ê
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Ê
and the deepest trough is 0.64 A from the Pt atom. In (II), the largest
0
Ê
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SHELXTL-Plus (Sheldrick, 1999); program(s) used to solve struc-
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È
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ꢁ
Acta Cryst. (2001). C57, 237±239
Malcolm J. Arendse et al.
[Pt(C26H24P2)(NO3)2] and [Pt(C25H22OP2)2](NO3)2Á2H2O 239