Binuclear dimethylplatinum (II) complexes each containing monodentate phosphine ligands and a bridging diphosphine ligand X(PPh2) 2, X = CH2 or NH. Molecular structure of cis,cis-[Me 2(pyPh2P)Pt(μ-Ph2PNHPPh2) Pt(PPh2py) Me2]·2CH2Cl2

Article abstract of DOI:10.1016/j.jorganchem.2005.01.002

Displacement of the labile bridging SMe₂ ligand in the organodiplatinum(II) complexes cis,cis-[Me₂Pt(μ-SMe ₂){μ-X(PPh₂)₂}PtMe₂], in which X(PPh₂)₂ is either bis(diphenylphosphino)amine [dppa (X = NH)], 1a, or bis(diphenylphosphino)methane [dppm (X = CH₂)], 1b, with 2 equiv of some monodentate phosphine ligands, L, gave a series of organodiplatinum(II) complexes with general formula cis,cis-[Me ₂LPt(μ-dppa)PtLMe₂][L = PPh₃, 2a, PPh ₂py(2-diphenylphosphinopyridine, PN), 3a, or P(O-ⁱPr) ₃, 4a] or cis,cis-[Me₂LPt(μ-dppm)PtLMe₂][L = PPh₃, 2b, PN, 3b, or P(O-ⁱPr)₃, 4b] in good yields. In these complexes the two metallic centers are held together by only one bridging diphosphine ligand with no metal-metal bond. When L is PPh ₂Me or PPhMe₂, the diplatinum(II) complexes are split to the corresponding monomers, [PtMe₂{X(PPh₂)₂}] and cis-[PtMe₂L₂]. No reaction was observed when L is pyridine or SMe₂. The complexes were fully characterized using multinuclear NMR (¹H, ¹³C, ³¹P and ¹⁹⁵Pt) methods, and the structure of cis,cis-[Me ₂(pyPh₂P)Pt(μ-Ph₂PNHPPh₂) Pt(PPh₂py)Me₂]·2CH₂Cl₂, 3a, has been determined crystallographically.

Full text of DOI:10.1016/j.jorganchem.2005.01.002

Journal of Organometallic Chemistry 690 (2005) 1600–1605
www.elsevier.com/locate/jorganchem
Binuclear dimethylplatinum (II) complexes each containing
monodentate phosphine ligands and a bridging diphosphine
ligand X(PPh2)2, X = CH2 or NH. Molecular structure of
cis,cis-[Me2(pyPh2P)Pt(l-Ph2PNHPPh2)Pt(PPh2py) Me2] Æ 2CH2Cl2
a,
a
b
b,
*
Mehdi Rashidi *, Katayoon Kamali , Michael C. Jennings , Richard J. Puddephatt
a
Department of Chemistry, Faculty of Sciences, Shiralz University, Shiraz 71454, Iran
b
Department of Chemistry, University of Western Ontario, London, Canada N6A 5B7
Received 20 December 2004; accepted 20 December 2004
Abstract
Displacement of the labile bridging SMe2 ligand in the organodiplatinum(II) complexes cis,cis-[Me2Pt(l-SMe2){l-
X(PPh2)2}PtMe2], in which X(PPh2)2 is either bis(diphenylphosphino)amine [dppa (X = NH)], 1a, or bis(diphenylphosphino)meth-
ane [dppm (X = CH2)], 1b, with 2 equiv of some monodentate phosphine ligands, L, gave a series of organodiplatinum(II) complexes
with general formula cis,cis-[Me2LPt(l-dppa)PtLMe2][L = PPh3, 2a, PPh2py(2-diphenylphosphinopyridine, PN), 3a, or P(O-iPr)3,
4a] or cis,cis-[Me2LPt(l-dppm)PtLMe2][L = PPh3, 2b, PN, 3b, or P(O-iPr)3, 4b] in good yields. In these complexes the two metallic
centers are held together by only one bridging diphosphine ligand with no metal–metal bond. When L is PPh2Me or PPhMe2, the
diplatinum(II) complexes are split to the corresponding monomers, [PtMe2{X(PPh2)2}] and cis-[PtMe2L2]. No reaction was
observed when L is pyridine or SMe2. The complexes were fully characterized using multinuclear NMR (1H, 13C, 31P and 195Pt)
methods, and the structure of cis,cis-[Me2(pyPh2P)Pt(l-Ph2PNHPPh2)Pt(PPh2py)Me2] Æ 2CH2Cl2, 3a, has been determined
crystallographically.
Ó 2005 Published by Elsevier B.V.
Keywords: Platinum; Organoplatinum; Binuclear complexes; Diphosphine ligands
1. Introduction
by two or more bridging ligands and metal–metal bonds
may also be involved. Bis(diphenylphosphino)methane
(dppm) [3] and the amine analog bis(diphenylphosph-
ino)amine (dppa) [4] are versatile ligands which usually
bridge two metal centers in forming binuclear com-
plexes, although there are cases in which they act as
chelate or monodentate ligands. There are many similar-
ities, and also some differences, in the coordination
chemistry of these two ligands [5]. In the diplatinum
complexes containing these ligands, the metallic centers
are usually held together by two bridging dppm or dppa
ligands and in many cases metal–metal bonds are pres-
ent as well [3,4,6]. However, recently a number of diplat-
inum(II) complexes containing two different bridging
Binuclear complexes, as the simplest multimetallic
systems, are of great interest because the neighboring
metals may ‘‘cooperate’’ in promoting difficult reactions,
and because electronic interactions between the two
metals can lead to distinctive properties [1,2]. In these
complexes, the metallic centers are usually held together
*
Corresponding author. Tel.: +98 711 228 4822; fax: +98 711 228
6008.
E-mail addresses: rashidi@chem.susc.ac.ir (M. Rashidi), pudd@
uwo.ca (R.J. Puddephatt).
0022-328X/$ - see front matter Ó 2005 Published by Elsevier B.V.
doi:10.1016/j.jorganchem.2005.01.002

M. Rashidi et al. / Journal of Organometallic Chemistry 690 (2005) 1600–1605
1601
ligands, e.g., cis,cis-[Me2Pt(l-SMe2)(l-dppm)PtMe2] [7],
[NBu4][(C6F5)2Pt(l-halide)(l-dppm)Pt(C6F5)2] [8] and a
particularly interesting dimeric complex cis,cis-
[Me2Pt(l-dppm)(l-dppa)PtMe2] (in which a direct com-
parison of dppm and dppa in equivalent positions was
possible) [5], have been reported. In continuation of
our interest in making diplatinum complexes of this
type, we report a new series of complexes of general for-
mula cis,cis-[Me2LPt{l-X(PPh2)2}PtLMe2], in which
X(PPh2)2 is either dppm(X = CH2) or dppa (X = NH)
and L is a monodentate phosphorus ligand with a rela-
tively large Tolman cone angle, e.g., PPh3, PPh2py(2-
diphenylphosphinopyridine, PN) or P(O-iPr)3 [9]. This
indicates that, in this type of dimer, the two metallic cen-
ters can be locked together with only one bridging
bidentate ligand and with no metal–metal bonding or
other bridging ligand present.
When L is PPh2Me or PPhMe2 (which have relatively
lower cone angles, but higher r-donor abilities com-
pared to the above mentioned monodentate phosphorus
ligands), then the dimers are split into the corresponding
monomers [PtMe2{X(PPh2)2}] and cis-[PtMe2L2]. Pyri-
dine or SMe2 are unable to displace the bridging labile
ligand SMe2 in complexes 1, and so no reaction was ob-
served between these reagents and 1, as monitored by 1H
NMR spectroscopy.
2.2. Characterization of the complexes
The dinuclear complexes were fully characterized by
1
their H, 13C, 31P and 195Pt NMR spectra. In the 31P
NMR spectrum of cis,cis-[Me2(Ph3P)Pt(l-dppa)Pt-
(PPh3)Me2], 2a (Fig. 1(b)), the two equivalent phospho-
rus atoms of dppa resonated as a singlet at d = 60.5 and
showed short range coupling platinum satellites with
1J(PtP) = 2142 Hz as well as platinum satellites arising
from long range coupling with 3J(PtP) = 46 Hz. The
splitting in the satellites corresponds to the phospho-
rus–phosphorus coupling when only one of the platinum
atoms is 195Pt with 2J(PP) = 55 Hz. No coupling was re-
solved between the dppa phosphorus and the phospho-
rus atom of the PPh3 ligand. A singlet at d = 27.5 with
1J(PtP) = 1910 Hz was assigned to the two phosphorus
atoms of the PPh3 ligands. Note that in 31P NMR spec-
trum of the dppm analog complex 4b, cis,cis-[Me2(iPr-
O)3P}Pt(l-dppm)Pt{P(O-iPr)3}Me2] (Fig. 1(c)), the
coupling between the phosphorus atom of P(O-iPr)3
with the phosphorus atom of dppm (2J(PP) = 17 Hz) is
also observed. Consistent with these results, the 195Pt
NMR spectrum (Fig. 1(a)) showed a doublet of doublets
of doublets signal at d = À4672 that is due the short
range coupling of each platinum with two inequivalent
phosphorus atoms directly connected to the platinum
with 1J(PtP) = 2148 Hz and 1J(PtP) = 1911 Hz which
further couples to the distant dppa phosphorus with
3J(PtP) = 43 Hz. In the 13C NMR spectrum of 2a, the
two methyl groups which are attached to the same plat-
inum atom are inequivalent. The carbon atom trans to
PPh3 coupled to the trans phosphorus and gave a dou-
2. Results and discussion
2.1. Synthesis of the complexes
As described in Scheme 1, reaction of the dimeric pre-
cursors cis,cis-[Me2Pt(l-SMe2)(l-dppa)PtMe2] [5], 1a,
or cis,cis-[Me2Pt(l-SMe2)(l-dppm)PtMe2] [7], 1b, each
of which contains a labile bridging SMe2, with 2 equiv
of L (L = PPh3, PN or P(O-iPr)3) in benzene proceeded
by displacement of SMe2 to give after 1 h the desired di-
mers cis,cis-[Me2LPt{l-X(PPh2)2}PtLMe2], 2–4, in good
yields. Note that the reaction with 1 equiv of L gave the
same dimer along with 0.5 equiv of unreacted starting
dimer. In these unusual dimers, the dinuclear integrity
is held by only one bridging ligand X(PPh2)2 with no
metal–metal bonding; each platinum center also bears
a monodentate ligand L and two methyl groups.
+2 L , -SMe2
cis-[PtMe2L2] + [PtMe2{X(PPh2)2}]
L=PMePh2 or PMe2Ph
P
P
2
P
P
Me2
S
blet at d = 5.9 with J(CPtrans) = 107 Hz which further
coupled to the cis phosphorus of dppa to give a doublet
Me
L
- SMe2
Pt
Pt
2 L
2
of doublets with J(CPcis) = 8 Hz. The coupling to 195Pt
+
Pt
Pt
Me
gave satellites with1J(PtC) = 634 Hz. The carbon atom
trans to the phosphorus atom of dppa resonated at
d = 4.3 and similarly gave the coupling constants
1J(PtC) = 634 Hz and 2J(CPtrans) = 97 Hz. However,
the resonance appeared as a doublet of multiplets
(which appeared as a second order pattern) due to the
long range coupling to the distant dppa phosphorus
atom (4-bond coupling). A similar pattern (Fig. 2) was
also observed in the 13C NMR of the P(O-iPr)3 analog
complex 4a. The observation of this long range coupling
could be attributed to the large PNP angle (see Scheme 2
Me
Me
Me
Me
L
Me
Me
L
P
P
P
P
2a
dppa
dppa
dppa
PPh3
1a
1b
dppa
dppm
3a
4a
PPh2py
P(O-iPr)3
2b
3b
4b
dppm
dppm
dppm
PPh3
PPh2py
P(O-iPr)3
Scheme 1.

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M. Rashidi et al. / Journal of Organometallic Chemistry 690 (2005) 1600–1605
Fig. 1. Selected NMR spectra: (a) the 195Pt resonance for complex 2a (see the inset) showing the doublet of doublets of doublets pattern arising from
3
two inequivalent 1J(PtP) couplings with further coupling to J(PtP); (b) the 31P NMR spectrum for complex 2a showing two resonances due to the
dppa and PPh3 phosphorus atoms with the corresponding couplings as shown. The asterisks indicate a very small trace of a monomeric impurity and
(c) the 31P NMR spectrum for complex 4b (see the inset) showing the 2J(PP) (phosphorus of P(O-iPr)3 with phosphorus of dppm) as well.
Fig. 2. 13C NMR spectrum of complex 4a (shown in the right inset). Most of the assignments are indicated. Left inset is the expansion of the region
for Me ligand trans to dppa. The peak shown by (i) indicates a very small trace of an impurity.

M. Rashidi et al. / Journal of Organometallic Chemistry 690 (2005) 1600–1605
1603
Table 1
Ph2P
Pt
PPh2
Pt
˚
Selected bond distances (A) and angles (°) for complex cis,cis-
[Me2(NP)Pt(l-dppa)Pt(PN)Me2], 3a
N
H
Pa'N
Mea
Pt(1)–C(12)
Pt(1)–P(1)
Pt(2)–C(21)
Pt(2)–P(2)
P(3)–N
2.097(10)
2.276(2)
2.095(8)
2.287(2)
1.684(7)
Pt(1)–C(11)
Pt(1)–P(3)
Pt(2)–C(22)
Pt(2)–P(4)
P(4)–N
2.097(9)
2.309(3)
2.101(10)
2.299(2)
1.703(7)
NPa
Mea'
Me
Me
Scheme 2. A Simplified representation of structure of cis,cis-[Me2(NP)-
Pt(l-dppa)Pt(PN)Me2], 3a.
C(12)–Pt(1)–C(11)
C(11)–Pt(1)–P(3)
C(21)–Pt(2)–C(22)
C(21)–Pt(2)–P(4)
N–P(3)–Pt(1)
83.3(4)
88.7(3)
84.8(4)
88.4(3)
105.1(3)
145.1(5)
C(12)–Pt(1)–P(1)
P(1)–Pt(1)–P(3)
C(22)–Pt(2)–P(2)
P(2)–Pt(2)–P(4)
N–P(4)–Pt(2)
89.9(3)
98.14(10)
87.3(3)
99.50(9)
104.1(3)
and the related discussion, which follows shortly). Two
triplets with platinum satellites at d = 0.13[2J(PtH) =
66.5 Hz and 3J(PH) = 7.5 Hz] and 0.60[2J(PtH) =
P(3)–N–P(4)
3
1
69.3 Hz and J(PH) = 6.7 Hz] were observed in the H
NMR spectrum of 2a for the two inequivalent CH3
groups on each platinum center. The NH proton reso-
nated as a broad signal at d = 4.87. The other complexes
were similarly characterized and the results are gathered
in the experimental section.
The structure of complex cis,cis-[Me2(NP)Pt(l-dppa)-
Pt(PN)Me2], 3a, was determined crystallographically
and is shown in Fig. 3, with selected bond parameters
listed in Table 1. Each of the Pt atoms has distorted
square planar stereochemistry and the two square pla-
nar cis-dimethylplatinum(II)-PN units are bridged by
the dppa ligand. The distances P–N = 1.684(7) and
possible from each other. This may also be responsible
3
for a nearly 50% increase in the J(PtP) value in the
31P NMR spectrum(see above) as compared to the same
coupling
(46 Hz vs 31 Hz). As expected therefore, the bite separa-
in
cis,cis-[Me2Pt(l-SMe2)(l-dppa)PtMe2]
˚
tion P3. . .P4 = 3.23 A, and the non-bonding Pt. . .Pt dis-
˚
tance of 5.68 A are greater than the corresponding
separations in the double bridged complexes cis,cis-
˚
[Me2Pt(l-SMe2)(l-dppa)PtMe2] (3.06 and 3.57 A,
respectively) and cis,cis-[Me2Pt(l-dppm)(l-dppa)PtMe2]
˚
˚
(3.09 A and 4.44 A, respectively). A simplified represen-
tation of structure of cis,cis-[Me2(NP)Pt(l-dppa)Pt(PN)
Me2], 3a, is shown in Scheme 2. The central N atom of
PNP ligand is directed towards one of the terminal PN
ligands and therefore, as indicated, some of the ligating
atoms are inequivalent. However, these atoms appear
equivalent in the NMR time scale in the corresponding
spectra discussed above. It therefore seems that the sim-
ple umbrella like inversion of the ligands about the N
atom of PNP can take place in solution to make the
whole molecule more symmetrical.
˚
1.703(7) A are similar to the distance in the free ligand
˚
dppa [1.692(2) A] [10]. The two angles NPPt = 104.1(3)°
and 105.1(3)° are close to the ideal tetrahedral angle and
indicate that there is no significant strain in the complex
as opposed to the strain in complex cis,cis-[Me2Pt-
(l-dppm)(l-dppa)PtMe2] in which the platinum centers
are held together by two bridging diphosphine ligands
[5]. The angle PNP = 145.1(5)° is very large (cf. the angle
PNP = 126.6(5)° in the double bridged dimer just men-
tioned). This configuration is probably to allow the
two very bulky PtP2C2 moieties to stay as far away as
3. Experimental
The 1H NMR spectra were recorded on a Bruker
Avance DPX 250 MHz spectrometer. 31P, 13C and
195Pt NMR spectra were recorded on a Bruker Avance
DRX 500 MHz. References were TMS (1H, 13C),
H3PO4 (31P), and aqueous K2PtCl4 (195Pt), and unless
otherwise stated, CDCl3 was used as solvent. All the
chemical shifts and coupling constants are in ppm and
Hz, respectively. The dimeric precursors cis,cis-
[Me2Pt(l-SMe2)(l-dppa)PtMe2] [5], 1a, and cis,cis-
[Me2Pt(l-SMe2)(l-dppm)PtMe2] [7], 1b, were prepared
by the literature methods.
3.1. cis,cis-[Me2(Ph3P)Pt(l-dppa)Pt(PPh3)Me2], 2a
A mixture of cis,cis-[Me2Pt(l-SMe2)(l-dppa)PtMe2],
1a, (70 mg, 0.078 mmol) and PPh3 (40.89 mg,
0.156 mmol) in benzene (10 ml) was stirred at room
Fig. 3. A view of the structure of cis,cis-[Me2(NP)Pt(l-dppa)Pt(PN)-
Me2], 3a.

1604
M. Rashidi et al. / Journal of Organometallic Chemistry 690 (2005) 1600–1605
temperature for 1 h. The solvent was removed and the
product was washed with n-hexane (5 ml) and dried un-
der vacuum. Yield: 77%; m.p. 171–172 °C (decomp.).
Anal. Calcd. for C64H63NP4Pt2: C, 56.51; H, 4.67; N,
1.03. Found: C, 56.8; H, 4.7; N, 1.0%. NMR in CDCl3:
d(1H) = 0.13 [t, 2J(PtH) = 66.5 Hz, 3J(PH) = 7.5 Hz,
2J(CPtextsubscriptcis) = not measured, 2 Me ligands],
24.7 [br. s, CH2 of dppm]; d(31P) = 27.3 [m,
1J(PtP) = 1880 Hz, 2J(PP) = 9 Hz, PPh3ligands], 17.6
[s, 1J(PtP) = 1904 Hz, 3J(PtP) = 18 Hz, 2J(PP) = 9 Hz,
2J(PP) = 21 Hz(dppm-PP), dppm]; d(195Pt) = À4718 [t,
1J(PtP) = 1892 Hz]. cis,cis-[Me2(NP) Pt(l-dppm)Pt(PN)-
Me2], 3b. Yield: 86%. NMR in CDCl3: d(1H) = 0.00
[m, 2J(PtH) = 66.0 Hz, 3J(PH) = 7.9 Hz, 6H, 2 Me li-
gands], 0.13 [m, 2J(PtH) = 69.3 Hz, 3J(PH) = 7.7 Hz,
6H,
2
Me ligands], 0.60 [t, 2J(PtH) = 69.3 Hz,
3J(PH) = 6.7 Hz, 6 H, 2 Me ligands], 4.87 [br., 1H,
NH]; d(13C) = 4.3 [m, 1J(PtC) = 634 Hz, 2J(CPtrans) =
97 Hz,
2
Me ligands trans to dppa], 5.9 [dd,
6H, 2
Me ligands], 3.37 [m, 3J(PtH) = 18.0 Hz,
1J(PtC) = 634 Hz, 2J(CPtrans) = 107 Hz, 2J(CPcis) =
8 Hz, 2 Me ligands trans to PPh3]; d(31P) = 27.5
2J(PH) = 9.0 Hz, 2H, CH2 of dppm], 8.10 [d,
3J(HH) = 4.2 Hz, 1H, H6 of PN]; d(31P) = 18.4 [s,
1J(PtP) = 1924 Hz, 3J(PtP) = not resolved, 2J(PP) =
20 Hz (dppm-PP), dppm], 26.8 [s, 1J(PtP) = 1873 Hz,
PN ligands]; d(195Pt) = À4720 [dd, 1J(PtP) = 1914 Hz,
1J(PtP) = 1882 Hz]. cis,cis-[Me2(iPr-O)3P}Pt(l-dppm)
Pt {P(O-iPr)3}Me2], 4b. Yield: 52%; m.p. 154 °C (de-
comp.). Anal. Calcd. for: C47H76O6P4Pt2: C, 45.12; H,
6.12. Found: C, 45.0; H, 6.0%. NMR in CDCl3:
d(1H) = 0.13 [t, 2J(PtH) = 64.5 Hz, 3J(PH) = 8.9 Hz,
1
1
[s, J(PtP) = 1910 Hz, PPh3 ligands], 60.5 [s, J(PtP) =
2142 Hz, 3J(PtP) = 46 Hz, 2J(PP) = 55 Hz (dppa-PP),
dppa]; d(195Pt) = À4672 [ddd, 1J(PtP) = 2148 Hz,
3
1J(PtP) = 1911 Hz, J(PtP) = 43 Hz].
The following complexes were made similarly using
cis,cis-[Me2Pt(l-SMe2)(l-dppa)PtMe2], 1a, or cis,cis-
[Me2Pt(l-SMe2)(l-dppm)PtMe2, 1b, and 2 equiv of the
corresponding
L
group:
cis,cis-[Me2(NP)Pt-
(l-dppa)Pt(PN)Me2], 3a. Yield: 73%; m.p. 146 °C (de-
comp.). Anal. Calcd. for C62H61N3P4Pt2: C, 54.58; H,
4.47; N, 3.08. Found: C, 54.2; H, 4.2; N, 2.8%. NMR
in CD2Cl2: d(1H) = 0.10 [m, 2J(PtH) = 66.5 Hz,
6H,
2
Me ligands], 0.42 [t, 2J(PtH) = 70.8 Hz,
3J(PH) = 7.1 Hz, 6H,
2
Me ligands], 0.84 [d,
i
3J(HH) = 5.9 Hz, 24 H, 6 Me groups of Pr groups],
i
4.41 [br., 6H, 6 CH groups of Pr groups], 3.96 [m,
3J(PH) = 8.2 Hz, 6H,
2
Me ligands], 0.64 [m,
3J(PtH) = 20.0 Hz, 2J(PH) = 9.8 Hz, 2H, CH2 of dppm];
d(13C) = À2.8 [dd, 1J(PtC) = 584 Hz, 2J(CPtrans) = 99
3
2J(PtH) = 69.3 Hz, J(PH) = 7.4 Hz, 6H, 2 Me ligands],
3
2
2
5.00 [m, J(PtH) ꢀ 10 Hz, J(PH) ꢀ 5 Hz, 1H, NH of
dppa], 8.15 [d, 3J(HH) = 4.0 Hz, 1H, H6 of PN];
d(31P) = 27.7 [s, 1J(PtP) = 1917 Hz, PN ligands], 63.7
[s, 1J(PtP) = 2119 Hz, 3J(PtP) = 46 Hz, 2J(PP) = 56 Hz
(dppa-PP), 2J(PP) = 6 Hz, dppa]. cis,cis-[Me2(iPr-
O)3P}Pt(l-dppa)Pt {P(O-iPr)3}Me2], 4a. Yield: 57%;
Hz, J(CPcis) = 11 Hz, 2 Me ligands trans to P(O-iPr)3],
8.9
[dd,
1J(PtC) = 586 Hz,
2J(CPtrans) = 142 Hz,
2J(CPcis) = 7 Hz,
2
Me ligands trans to dppm];
d(31P) = 18.8 [s, 1J(PtP) = 1860 Hz, 3J(PtP) = not re-
solved, 2J(PP) = 18 Hz (dppm-PP), 2J(PP) = 17 Hz
(phosphorus of P(O-iPr)3with phosphorus of dppm),
dppm], 129.7 [s, 1J(PtP) = 3232 Hz, 2J(PP) = 17 Hz
(phosphorus of P(O-iPr)3 with phosphorus of dppm),
P(O-iPr)3 ligands]; d(195Pt) = À4635 [dd, 1J(PtP) =
m.p.
152 °C
(decomp.).
Anal.
Calcd.
for
C46H75NO6P4Pt2: C, 44.12; H, 6.04; N, 1.12. Found:
C, 44.6; H, 5.8; N, 1.1%. NMR in CDCl3:
d(1H) = 0.35 [t, 2J(PtH) = 60.0 Hz, 3J(PH) = 7.0 Hz,
1
1860 Hz, J(PtP) = 3226 Hz].
3
12H, 4 Me ligands], 0.72 [d, J(HH) = 6.1 Hz, 24H, 6
i
Me groups of Pr groups], 4.31 [br., 6H, 6 CH groups
i
of Pr groups], 4.93 [br., 1H, NH]; d(13C) = À0.8 [dd,
1J(PtC) = 560 Hz, 2J(CPtrans) = 106 Hz, 2J(CPcis) =
11 Hz, 2 Me ligands trans to P(O-iPr)3], 9.1 [m,
1J(PtC) = 588 Hz, 2J(CPtrans) = 139 Hz, 2 Me ligands
trans to dppa]; d(31P) = 65.0 [s, 1J(PtP)=2078 Hz,
3J(PtP) = 23 Hz, 2J(PP) = 14 Hz, 2J(PP) = 58 Hz, dppa],
131.4 [s, 1J(PtP) = 3242 Hz, 2J(PP) = 14 Hz, P(O-iPr)3 li-
gands]; d(195Pt) = À4599 [dd, 1J(PtP) = 3247 Hz,
3.2. Reaction of cis,cis-[Me2Pt(l-SMe2)(l-dppa)-
PtMe2], 1a, with PPhMe2
A mixture of cis,cis-[Me2Pt(l-SMe2)(l-dppa)PtMe2],
1a,
(50 mg,
0.056 mmol)
and
PPhMe2(17 ll,
0.111 mmol) in benzene (15 ml) was stirred at room tem-
perature for 1 h. The solvent was removed and the prod-
uct was washed with n-hexane (5 ml) and dried under
vacuum. The product was identified as an equivalent
mixture of the monomers cis-[PtMe2(PPhMe2)2] and
1J(PtP) = 2107 Hz].
cis,cis-[Me2(Ph3P)Pt(l-dppm)Pt-
(PPh3)Me2], 2b. Yield: 81%; m.p. 164–176 °C (decomp.).
Anal. Calcd. for C65H64P4Pt2: C, 57.44; H, 4.75. Found:
C, 58.2; H, 4.8%. NMR in CDCl3: d(1H) = 0.31 [t,
1
[PtMe2(dppa)] as confirmed by its H NMR spectrum
[5,11].
3
2J(PtH) = 68.8 Hz, J(PH) = 9.7 Hz, 6H, 2 Me ligands],
0.37 [t, 2J(PtH) = 55.7 Hz, 3J(PH) = 6.7 Hz, 6H, 2 Me li-
Similar results were obtained for the reactions of
complex 1a with PPh2Me and complex cis,cis-
[Me2Pt(l-SMe2)(l-dppm)PtMe2, 1b, with PPh2Me and
the resulting monomers were identified by their 1H
NMR spectra [11,12].
3
2
gands], 3.14 [m, J(PtH) ꢀ 32 Hz, J(PH) = 8.1 Hz, 2H,
CH2 of dppm]; d(13C) = 7.0 [dd, 1J(PtC) = 621 Hz,
2
2J(CPtrans) = 106 Hz, J(CPcis) = not measured, 2 Me li-
1
gands], 7.9 [dd, J(PtC) = 637 Hz, J(CPtrans) = 104 Hz,
2

M. Rashidi et al. / Journal of Organometallic Chemistry 690 (2005) 1600–1605
1605
Table 2
Crystal data and structure refinement for 3a
The largest residue electron density peak (3.008)
was associated with one of the platinum atoms.
Full-matrix least squares refinement on F2 gave
R1 = 4.91 for 2r data and wR2 = 11.24 for all data
(GOOF = 0.994).
Formula
Formula weight
Temperature (K)
C62H61N3P4Pt2
1362.20
200(2)
˚
Wavelength (A)
0.71073
Orthorhombic
Pca2(1)
Crystal system
Space group
˚
a (A)
16.2101(2)
18.3159(2)
18.6612(3)
90
4. Supplementary material
˚
b (A)
˚
c (A)
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC no. 256450. Copies of this informa-
tion may be obtained free of charge from the Director,
CCDC, 12 Union Road, CB2 1EZ, UK (fax: +44-
1223-336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
b (°)
Volume (A )
3
˚
5540.56(13)
4
1.633
Z
D(calc) (Mg mÀ3
)
Absorption coefficient (mmÀ1
F(000)
Number of reflections
)
5.202
2680
58499
Number of independent reflections
Absorption correction
GOOF (F2)
12248 [R(int) = 0.100]
Integration
0.994
R1, wR2 [I > 2r(I)]
R1, wR2 (all data)
0.0491, 0.0990
0.0928, 0.1124
Acknowledgement
We thank the Shiraz University Research Council,
Iran (Grant No. 82-SC-1599-C240) and the NSERC
(Canada) for financial support.
3.3. X-ray structure determination
Crystals of cis,cis-[Me2(NP)Pt(l-dppa)Pt(PN)Me2],
3a, were grown from a concentrated methylene chloride
solution by slow diffusion of hexane. A colourless shoe-
box was mounted on a glass fiber. Data were collected at
200 K using a Nonius Kappa-CCD diffractometer with
COLLECT software (Nonius B.V., 1998). The unit cell
parameters were calculated and refined from the full
data set. Crystal cell refinement and data reduction were
carried out using DENZO (Nonius B.V., 1998). The
data were scaled using SCALEPACK (Nonius B.V.,
1998). The crystal data and structure refinement para-
meters are listed in Table 2. The reflection data and sys-
tematic absences were consistent with an orthorhombic
space group: Pca2 (1).
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