Synthesis and structural characterisation of group 10 homo- and hetero-dimetallic sulfur-bridged complexes of the [Ni(ema)(μ-S,S′) M(diphos)] (M = Ni, Pd, Pt) type

Article abstract of DOI:10.1002/ejic.200500678

The series of group 10 homo- and hetero-dimetallic sulfur-bridged complexes [Ni(ema)(μ-S,S′)M(diphos)], [M = nickel, palladium or platinum; diphos = 1,3-bis(diphenylphosphanyl)-propane or 1,2-bis(diphenylphosphanyl)ethane], have been synthesised. Their pr

Full text of DOI:10.1002/ejic.200500678

FULL PAPER
Synthesis and Structural Characterisation of Group 10 Homo- and Hetero-
Dimetallic Sulfur-Bridged Complexes of the [Ni(ema)(µ-S,SЈ)M(diphos)]
(M = Ni, Pd, Pt) Type
Samantha E. Duff,[a] J. Elaine Barclay,[a] Sian C. Davies,[a] Peter B. Hitchcock,[b] and
David J. Evans*[a]
Keywords: Nickel / Palladium / Platinum / Heterometallic complexes
The series of group 10 homo- and hetero-dimetallic sulfur-
bridged complexes [Ni(ema)(µ-S,SЈ)M(diphos)], [M = nickel,
palladium or platinum; diphos = 1,3-bis(diphenylphosphanyl)-
propane or 1,2-bis(diphenylphosphanyl)ethane], have been
synthesised. Their properties and the crystal structures of five
of the series are described. The dinickel complexes are good
structural analogues of the dinickel subunit of the nickel-
containing enzyme acetyl-CoA synthase.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2005)
tion of dinuclear group 10 complexes as mimics for the di-
nickel sub-site of the A cluster.[5–10] Herein we report the
synthesis and properties of the series of complexes [Ni-
(ema)(µ-S,SЈ)M(diphos)], where M is nickel, palladium or
platinum, H4ema is N,NЈ-ethylenebis(2-mercaptoacetamide)
and where diphos is 1,3-bis(diphenylphosphanyl)propane
(dppp) or 1,2-bis(diphenylphosphanyl)ethane (dppe).
Introduction
The nickel enzyme acetyl-CoA synthase catalyses the
synthesis of acetyl-CoA. The reaction parallels the indus-
trially important Reppe process for the synthesis of acetic
acid, both apparently involving metal–carbonyl, methyl–
metal and acyl–metal intermediates.[1] Protein crystallogra-
phy[2–4] shows at the active site, the A cluster, an Fe4S4 clus-
ter bridged through cysteinylthiolate sulfur to a proximal
nickel that is then linked to a distal nickel() atom in an
N2S2 coordination environment, Figure 1. The cis-planar
N2S2 coordination is from a deprotonated Cys–Gly–Cys se-
Results and Discussion
quence of the protein. Following publication of the crystal Synthesis and Spectroscopy
structures there has been a renewed vigour in the prepara-
Previously, we have demonstrated that the homonuclear
complexes [Ni(ema)(µ-S,SЈ)Ni(dppp)] (1) and [Ni(ema)(µ-
S,SЈ)Ni(dppe)] (2) can be readily prepared from the reaction
of equimolar amounts of [NEt4]2[Ni(ema)] and [NiCl2-
(diphos)] in acetonitrile solution.[5] Here, a similar method-
ology has been applied to isolate, from the appropriate
[MCl2(diphos)], the heteronuclear dimetallic complexes [Ni-
(ema)(µ-S,SЈ)M(diphos)], M = Pd, diphos = dppp (3) or
dppe (4); M = Pt, diphos = dppp (5) or dppe (6), in good
yield, Equation (1).
[NEt4]2[Ni(ema)] + [MCl2(diphos)] Ǟ
[Ni(ema)(µ-S,SЈ)M(diphos)] + 2[NEt4]Cl
(1)
All complexes have been characterised by EI-MS and the
structures of 1[5] and 3–6 have been confirmed by X-ray
crystallography. Satisfactory elemental analyses (C, H, N)
are obtained for all compounds except 3, which, for reasons
unknown, gave consistently poor results. However, spectro-
scopic parameters and the mass spectrum of this compound
are fully consistent with the crystal structure.
Figure 1. The active site, A cluster, of acetyl-CoA synthase.
[a] Department of Biological Chemistry, John Innes Centre,
Norwich Research Park, Colney, Norwich, NR4 7UH, UK
E-mail: dave.evans@bbsrc.ac.uk
[b] Department of Chemistry, University of Sussex,
Falmer, Brighton, BN1 9QJ, UK
Eur. J. Inorg. Chem. 2005, 4527–4532
DOI: 10.1002/ejic.200500678
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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S. E. Duff, J. Elaine Barclay, S. C. Davies, P. B. Hitchcock, D. J. Evans
FULL PAPER
In the solid, complexes 1–6 exhibit an infra-red amido- Table 2. Colour of solutions of complexes 1–6 in acetonitrile and
carbonyl stretch in the range 1566–1578 cm–1. The 31P{H}
methanol.
NMR chemical shifts for solutions in methanol and in di-
methyl sulfoxide are consistent with diphosphane chelate
ligation and, as expected, depend on the chelate ring size;
Complex
MeCN
MeOH
[Ni(ema)Ni(dppp)]
[Ni(ema)Ni(dppe)]
(1)
(2)
(3)
(4)
(5)
(6)
emerald green
emerald green
royal blue
violet
cerise
peach
midnight blue
indigo
deep red
burgundy
pink
the chemical shifts observed for five-membered (dppe) che- [Ni(ema)Pd(dppp)]
[Ni(ema)Pd(dppe)]
late rings (ca. 49 to 62 ppm) are larger than those for six-
[Ni(ema)Pt(dppp)]
membered (dppp) rings (ca. –5 to 1 ppm).[11] The single res-
[Ni(ema)Pt(dppe)]
orange
onance observed in each case confirms the equivalence of
the phosphorus atoms in solution at ambient temperature.
The values for 2 are comparable to those of the related com-
The cyclic voltammogram of 1 in dichloromethane shows
plexes [Ni(L)(µ-S,SЈ)Ni(dppe)](PF6)2 {L = N,NЈ-diethyl- a reversible one electron process at E1/2 = –0.42 V (vs. SCE)
3,7-diazanonane-1,9-dithiolate(2–)} (CD2Cl2, 61.1 ppm)[6] assigned to a NiII/NiI couple of the NiP2S2 moiety, a similar
and [Ni(CGC)(µ-S,SЈ)Ni(dppe)] (CGC
=
cys–gly–cys) process at E1/2 = –0.47 V (vs. SCE) has been reported for
[Ni(L)(µ-S,SЈ)Ni(dppe)](PF6)2.[6] A second feature at Epc
(CD3CN, 56.7 and 57.5 ppm).[8]
In the solid state the nickel complexes are coloured = –1.39 V (vs. SCE) may be assigned to an irreversible re-
green, palladium blue-black and platinum red. The elec- duction NiI/Ni0 at NiP2S2 or an irreversible NiII/NiI couple
tronic absorption spectra of solutions of 1–6 exhibit several at the other nickel site. The cyclic voltammetry of the com-
absorbance peaks as expected, and their parameters are col- plexes 2–6 has not been investigated.
lected in Table 1. The colour in solution is dependent on
It has been observed that 1,10-phenanthroline will che-
solvent, Table 2. The nickel and palladium complexes show late and extract the proximal nickel from the acetyl-CoA
a dramatic colour difference on changing solvent from ace- synthase A cluster.[13] The effect has been observed also in
tonitrile to methanol. This is a consequence of the ability of
a
synthetic analogue, [Ni(PhPepS)(µ-S,SЈ)Ni(dppe)]
such square-planar complexes to coordinate extra (solvent) {PhPepSH4 = N,NЈ-phenyl(o-mercaptobenzamide)}, of the
ligands in solution to establish an equilibrium between dinickel subsite of the A cluster where it is proposed that
four-, five- and six-coordinate species.[12] However, the the nickel is removed from the NiP2S2 unit.[9] The same
NMR in methanol does not support the presence of a six- reaction occurs with complexes 1 and 2, in dichloromethane
coordinate, paramagnetic species.
solvent, using a ten-fold excess of 1,10-phenanthroline.
Table 1. Electronic absorption spectrum parameters for complexes 1–6 in acetonitrile and methanol solution.
Complex
MeCN
MeOH
λ [nm]
ε [dm3mol–1 cm–1]
λ [nm]
ε [dm3mol–1 cm–1]
[Ni(ema)Ni(dppp)] (1)
630
468
280
–
1230
250
22590
–
586
447
320
256
222
575
459
308
287
242
545
438
325 sh
263 sh
221 sh
546
445
–
229
522
395
351
–
225
518
405
361
–
2550
1500
12710
28930
52760
1170
890
8490
9510
13420
1710
1760
7960
21140
40470
820
980
–
14510
590
1890
2830
–
–
–
[Ni(ema)Ni(dppe)] (2)
[Ni(ema)Pd(dppp)] (3)
623
472
282
1040
860
14480
581
449
319 sh
278 sh
225 sh
581
443
274
224
535
411
365
319
227
533
414
382
323
1540
2570
3860
20220
44260
1130
750
11480
27770
2910
5780
6740
3057
97080
430
[Ni(ema)Pd(dppe)] (4)
[Ni(ema)Pt(dppp)] (5)
43550
340
1380
2150
–
[Ni(ema)Pt(dppe)] (6)
2290
2080
2850
60760
244
226
24540
4528
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Eur. J. Inorg. Chem. 2005, 4527–4532

Dimetallic Sulfur-Bridged Complexes of the [Ni(ema)(µ-S,SЈ)M(diphos)]
FULL PAPER
There is, however, under similar conditions, no reaction of
1,10-phenanthroline with the heterometallic complexes 3–6,
with [NEt4]2[Ni(ema)] or with the trinickel complex [NEt4]2-
[Ni{Ni(ema)(µ-S,SЈ)}2],[5] which provides further confirm-
ation that the phosphine-ligated nickel is lost and that the
nickel atom associated with the Ni(ema) moiety is not che-
lated by 1,10-phenanthroline.
Structures
The crystal structure of 1·Et2O[5] (Figure 2) shows that
each nickel ligand sphere is slightly distorted square planar,
with nickel(1) ligated by the two phosphorus atoms from
the dppp ligand and the two sulfur atoms of the ema ligand
and the other nickel, (2), ligated by the two nitrogen and
two sulfur atoms of the ema ligand. The dppp-ligated nickel
atom may be considered to lie within the S2P2 mean plane
[displaced 0.0035(5) Å from the plane towards the ema-lig-
ated Ni], which is essentially flat [deviations from the mean
planes lie in the range –0.0238(9) to 0.0241(9) Å, where the
negative sign indicates opposite side of the mean plane]; the
most distorted angle about this nickel is 80.93(3)°. This is
similar in the other two dppp-ligated metal complexes, with
the metal atoms lying within 0.020(2) Å of the S2P2 mean
planes, which in turn have atoms lying in the ranges
–0.017(3) to 0.017(4) and –0.010(2) to 0.010(2) Å from the
mean planes in 3 and 5, respectively. This is, however, dif-
ferent to the arrangement in the dppe-ligated complexes. In
these, the S2P2 planes are twisted with atoms lying in the
ranges –0.2134(13) to 0.2109(13) Å and –0.2556(13) to
0.2590(13) Å in the two independent molecules in 4 and
–0.1925(3) to 0.1949(13) in 6. The metal atoms lie 0.1075(6)
and 0.0712(6) Å from the mean planes in 4 and 0.0591(6)
in 6. The ema-chelated nickel atom lies 0.1534(6) Å from
the N2S2 plane [displaced in the direction away from Ni(1)]
with an angle of 169.52(8)° for a N–Ni–S angle being the
most distorted. This distortion is similar in all the com-
plexes. The dihedral (hinge) angle at the bridging sulfur
atoms in 1 is 111.22°. The Ni–S bond lengths within the
chelate ring (2.12 Å) are slightly shorter and the bridge dis-
tances (2.28 Å) slightly longer than those observed (2.14–
2.19 Å and 2.19–2.24 Å, respectively) for other synthetic
sulfur-bridged dinickel complexes such as [Ni(L)(µ-S,SЈ)-
Ni(dppe)](PF6)2.[6] Other angles and bond lengths about the
nickel atoms and the Ni···Ni distance [2.6897(5) Å] are sim-
ilar to those reported for related “Ni(µ-S)2NiN2” struc-
tures.[7]
Figure 2. A view of [Ni(ema)(µ-S,SЈ)Ni(dppp)] (1) showing atom
numbering scheme, hydrogen atoms omitted for clarity.
alternating ab planes lying on opposite sides of the Ni(ema)
planes (Figure 3). This packing arrangement is identical to
that in 3 and 5, while the Ni–ema planes are also found in
4 and 6. There is a difference in the packing in 6, however,
as the Pt–dppe groups are not “staggered” along the crys-
tallographic a vector as they are in the other four arrange-
ments.
Figure 3. Packing arrangements of [Ni(ema)(µ-S,SЈ)Ni(dppp)] (1)
as viewed along (a) the crystallographic c axis and (b) the b axis.
The Ni(ema) group of the complex forms a curved “wall”
The [Ni(ema)(µ-S,SЈ)M(diphos)] molecules in complexes
around two of the phenyl groups of the dppp ligand, which 3, 4, 5 and 6 have structures similar to complex 1. In 4 there
are orientated “edge-on” to the Ni(ema) group. Within each are two independent molecules within the asymmetric unit.
PPh group, the normals to the second phenyl rings are ori- Representative structures of the heterometallic complexes 3
entated at 111.3 and 102.6°, respectively, to those of the first and 4 are shown in Figure 4 and Figure 5, respectively. A
two. The complex molecules are arranged with the Ni(ema) comparison of selected bond lengths and angles are given
groups forming approximate (due to the curved nature of in Table 3. On substitution of nickel(1) by palladium, there
the ema ligands) planes parallel to the crystallographic bc is no significant change in the average Ni–N bond length
plane; viewed along the crystallographic b direction, the and only a very slight lengthening of the average Ni–S bond
molecules are arranged in pairs with the Ni(dppp) groups in length within the Ni(ema); replacement of palladium by
Eur. J. Inorg. Chem. 2005, 4527–4532
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S. E. Duff, J. Elaine Barclay, S. C. Davies, P. B. Hitchcock, D. J. Evans
FULL PAPER
platinum leads to no further increase in bond length.
Within the NiP2S2 fragment there is again an elongation of
the M–P and M–S bond lengths on substitution of nickel(1)
by palladium (0.08 and 0.13 Å, respectively) but no further
change when palladium is replaced by platinum. On chang-
ing from dppp to dppe chelation, independent of metal,
there is a decrease in the M–P–C(alkane) angle from ca.
116° to ca. 108° that helps maintain the square-planar envi-
ronment. The dihedral (hinge) angle at the bridging sulfur
atoms is similar in all complexes, ranging from 111–117°.
The nickel to metal distance increases from 2.6897(8) Å in
1 to 2.780(2) Å in 3, which is similar to the distance in the
heterometallic complexes 4 and 5 and slightly shorter than
that in 6 [2.8653(5) Å]. The longer platinum–nickel distance
is consistent with the larger hinge angle in the latter com-
plex.
Conclusions
The series of six group 10 homo- and hetero-dimetallic
sulfur-bridged complexes of the [Ni(ema)(µ-S,SЈ)-
M(diphos)] (M = Ni, Pd, Pt; diphos = dppp, dppe) type
have been prepared and characterised; five by X-ray crystal-
lography. The geometric parameters about the metal atoms
for complex 1 and 3–6 resemble those reported for the di-
nickel subunit of the A-cluster of acetyl-CoA synthase: in
complex 1 the nickel(1) and nickel(2) atoms mimic the A
cluster distal nickel and proximal nickel, respectively.
Figure 4. A molecule of [Ni(ema)(µ-S,SЈ)Pd(dppp)] (3), hydrogen
atoms omitted for clarity.
Experimental Section
General: All manipulations were performed under dinitrogen, un-
less otherwise stated, using either Schlenk or vacuum-line tech-
niques. Solvents were dried with appropriate drying agents and dis-
tilled under dinitrogen prior to use. [NiCl2(dppp)] was purchased
from Aldrich and [Pd(1,5-cylcooctadiene)Cl2], [Pt(1,5-cylcooctadi-
ene)Cl2] and [PdCl2(dppe)] were purchased from Alfa Aeser. [NEt4]2-
[Ni(ema)],[14] [PtCl2(dppp)], [PtCl2(dppe)] and [PdCl2(dppp)] were
obtained by adaptation of published procedures.[15] [Ni(ema)(µ-
S,SЈ)Ni(dppp)] (1) and [Ni(ema)(µ-S,SЈ)Ni(dppe)] (2) were pre-
pared as we recently reported.[5] IR spectra were recorded with a
Shimadzu FTIR-8000 spectrophotometer and UV/Vis spectra with
a Perkin–Elmer Lambda 25. 31P NMR were obtained with a Jeol
Lambda 400 spectrometer. Electrospray ionisation mass spectra, in
methanol solution, were measured with a Deca XPplus ion trap
mass spectrometer from Thermo Finnigan. Elemental analyses
were by Medac Ltd, Egham, Surrey, UK.
Figure 5. Molecular structure of [Ni(ema)(µ-S,SЈ)Pd(dppe)] (4), hy-
drogen atoms omitted for clarity.
Table 3. Comparison of selected bond lengths [Å], metal–metal separation [Å] and hinge angle [°] in complexes 1 and 3–6.
Complex
Ni(2)–S
Ni(2)–N
M–P
M–S
M–Ni
Hinge angle
[Ni(ema)Ni(dppp)]
[Ni(ema)Pd(dppp)]
[Ni(ema)Pd(dppe)]
[Ni(ema)Pt(dppp)]
[Ni(ema)Pt(dppe)]
(1)
2.1224(5)
1.8298(76)
1.8338(64)
1.8400(19)
1.8377(21)
1.8398(41)
2.1892(2)
2.2712(3)
2.2651(44)
2.2624(20)
2.2578(65)
2.2812(2)
2.4092(18)
2.4064(48)
2.4098(8)
2.4084(93)
2.6897(5)
2.7803(14)
2.7927(129)
2.7950(7)
2.8653(5)
111.22
110.37
112.16
110.78
117.22
(3)
2.1465(20)
2.1556(35)
2.1560(24)
2.1597(92)
(4)[a]
(5)
(6)
[a] Average values from the two independent molecules within the asymmetric unit.
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Eur. J. Inorg. Chem. 2005, 4527–4532

Dimetallic Sulfur-Bridged Complexes of the [Ni(ema)(µ-S,SЈ)M(diphos)]
FULL PAPER
Preparations
11.8017(3), b = 16.9502(4), c = 19.2990(4) Å, α = 65.591(1), β =
72.565(1), γ = 81.065(1), V = 3351.81(14) Å3, Z = 4, Dc
=
[Ni(ema)(µ-S,SЈ)Pd(dppp)] (3): A slurry of [PdCl2(dppp)] (0.146 g,
2.49×10–4 mol) in MeCN (20 mL) was added to a stirred solution
of [NEt4]2[Ni(ema)] (0.130 g, 2.49×10–4 mol) in MeCN (10 mL).
The resultant black solution was stirred at room temp. for 12 h,
then diethyl ether (10 mL) was added dropwise. Within 4 h blue-
black crystals were formed and collected by filtration (0.12 g, 62%).
1.617 mg/m3; data collection method: 95 mm CCD camera on κ-
goniostat, CCD rotation images, thick slices, scans at T = 173(2) K,
λ = 0.71073 Å, θmax = 25.02°; 11766 unique reflections used, 9510
with I Ͼ 2σI, F(000) = 1668, µ = 1.358 mm–1, R1/wR2 (I Ͼ 2σI) =
0.036/0.077, R1/wR2 (all data) = 0.052/0.084, goodness-of-fit on F2
= 1.016.
IR (KBr): ν
= (CO) 1578 cm–1. 31P NMR (162 MHz. CD3OD;
˜
max
ref. H3PO4): δ = –5.11 (s) ppm, ([D6]DMSO): δ = 5.22 (s) ppm.
[Ni(ema)(µ-S,SЈ)Pt(dppp)]·2CH2Cl2 (5·2CH2Cl2): C33H34N2Ni-
O2P2PtS2, CH2Cl2, M = 1040.33; orthorhombic, space group Pbca,
a = 16.6045(3), b = 27.3310(5), c = 17.1881(2) Å, V = 7800.3(2) Å3,
Z = 8, Dc = 1.772 mg/m3; data collection method: 95 mm CCD
camera on κ-goniostat, CCD rotation images, thick slices, scans at
T = 173(2) K, λ = 0.71073 Å, θmax = 26.01°; 7652 unique reflections
used, 5827 with [I Ͼ 2σ(I)], F(000) = 4112, µ = 4.564 mm–1, R1/
wR2 (I Ͼ 2σI) = 0.038/0.083, R1/wR2 (all data) = 0.061/0.092, good-
ness-of-fit on F2 = 1.045
MS: m/z = 783 (100) [M+ + H+ ].
[Ni(ema)(µ-S,SЈ)Pd(dppe)] (4): To a slurry of [PdCl2(dppe)] (0.300 g,
5.22×10–4 mol) in MeCN (10 mL) was added solid [NEt4]2-
[Ni(ema)] (0.273 g, 5.22×10–4 mol) and additional MeCN (5 mL).
The resultant black solution was stirred at room temp. for 30 min,
then diethyl ether (5 mL) was added dropwise. A brown solid
(0.25 g, 63%) was collected by filtration. C32H32N2NiO2P2PdS2
(767.80): calcd. C 50.1, H 4.2, N 3.7; found C 50.0, H 4.2, N 3.7.
IR (KBr): νmax = (CO) 1567 . 31P NMR (162 MHz. CD3OD; ref.
˜
[Ni(ema)(µ-S,SЈ)Pt(dppe)] (6): C32H32N2NiO2P2PtS2, M = 856.46;
monoclinic, space group P21/c, a = 11.0225(4), b = 16.4895(5), c =
H3PO4): δ = 62.64 (s) ppm, ([D6]DMSO): δ = 61.96 (s) ppm. MS:
m/z = 769 (100) [M+ + H+]. Recrystallisation from a methanol/
diethyl ether mixture gave blue-black crystals of 4·1½MeOH
(0.22 g, 52%).
17.3899(4) Å, β = 100.920(2), V = 3103.5(2) Å3, Z = 4, Dcalcd.
=
1.833 mg/m3; data collection method: 95 mm CCD camera on κ-
goniostat, CCD rotation images, thick slices, scans at T = 173(2) K,
λ = 0.71073 Å, θmax = 26.02°; 6094 unique reflections used, 5193
with [I Ͼ 2σ(I)], F(000) = 1688, µ = 5.381 mm–1, R1/wR2 [I Ͼ 2σ(I)]
= 0.027/0.051, R1/wR2 (all data) = 0.038/0.054, goodness-of-fit on
F2 = 1.041.
[Ni(ema)(µ-S,SЈ)Pt(dppp)] (5): To a white slurry of [PtCl2(dppp)]
(0.330 g, 4.87×10–4 mol) in MeCN (20 mL) was added a solution
of [NEt4]2[Ni(ema)] (0.255 g, 4.87×10–4 mol) in MeCN (10 mL).
The solution was stirred for a further 10 min before the volume
was decreased in vacuo to 15 mL. Diethyl ether was layered onto
the solution and a red product precipitated overnight which was
collected by filtration (0.29 g, 68%). C33H34N2NiO2P2PtS2
(870.48): calcd. C 45.5, H 3.9, N 3.2; found C 46.0, H 4.4, N 3.2.
CCDC-258104 (for 1), -279513 (for 3), -279514 (for 4), -279515 (for
5) and -279516 (for 6) contain the supplementary crystallographic
data for this paper. These data can be obtained free of charge from
The Cambridge Crystallographic Data Centre via www.ccdc.cam.
ac.uk/data_request/cif.
IR (KBr): ν
= (CO) 1578 cm–1. 31P NMR (162 MHz. CD3OD;
˜
max
ref. H3PO4): δ = –3.70 (s) ppm; ([D6]DMSO): δ = –2.87 (s) ppm.
MS: m/z =871 (100) [M+ + H+]. Recrystallisation from dichloro-
methane gave crystals of 5·2CH2Cl2.
Acknowledgments
[Ni(ema)(µ-S,SЈ)Pt(dppe)] (6): Compound 6 was prepared similarly
to 5 in 69% yield from [PtCl2(dppe)]. C32H32N2NiO2P2PtS2
(856.46): calcd. C 44.9, H 3.8, N 3.3; found C 43.9, H 4.0, N 3.3.
The Biotechnology and Biological Sciences Research Council are
thanked for funding and the John Innes Foundation for a postgrad-
uate studentship (S. E. D). Dr Lionel Hill, JIC Metabolite Service
is thanked for mass spectrometry.
IR (KBr): ν
= (CO) 1566 cm–1. 31P NMR (162 MHz. CD3OD;
˜
max
ref. H3PO4): δ = 49.01 (s) ppm; ([D6]DMSO): δ = 48.92 (s) ppm.
MS: m/z =857 (100) [M+ + H+].
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Thiele, P. Römer, R. Huber, O. Meyer, Proc. Natl. Acad. Sci.
U. S. A. 2004, 101, 446–451.
[5] S. E. Duff, J. E. Barclay, S. C. Davies, D. J. Evans, Inorg. Chem.
Commun. 2005, 8, 170–173.
Crystal Data
[Ni(ema)(µ-S,SЈ)Ni(dppp)]·Et2O (1·Et2O): C33H34N2Ni2O2P2S2,
C4H10O, M = 808.2; orthorhombic, space group Pcab (equiv. to
Pbca, no. 61), a = 16.557(3), b = 16.799(8), c = 26.931(5) Å, V =
7491(4) Å3, Z = 8, Dcalcd. = 1.433 mg/m3; data collection method:
CAD4 scintillation counter, ω scans at T = 150(2) K, λ =
0.71073 Å, θmax = 28.0°; 9000 unique reflections used, 5793 with
I Ͼ 2σI, F(000) = 3376, µ = 1.240 mm–1, R1/wR2 [I Ͼ 2σ(I)] =
0.039/0.078, R1/wR2 (all data) = 0.073/0.094, goodness-of-fit on
F2 = 1.040.
[6] Q. Wang, A. J. Blake, E. S. Davies, E. J. L. McInnes, C. Wilson,
M. Schröder, Chem. Commun. 2003, 3012–3013.
[7] P. V. Rao, S. Bhaduri, J. Jiang, R. H. Holm, Inorg. Chem. 2004,
43, 5833–5849.
[Ni(ema)(µ-S,SЈ)Pd(dppp)]·Et2O (3·Et2O): C33H34N2NiO2P2PdS2,
C4H10O, M = 855.9; orthorhombic, space group Pbca, a =
16.7601(8), b = 27.0435(14), c = 16.9278(5) Å, V = 7672.6(6) Å3, Z
= 8, Dcalcd. = 1.482 mg/m3; data collection method: 95mm CCD
camera on κ-goniostat, CCD rotation images, thick slices, scans at
T = 173(2) K, λ = 0.71073 Å, θmax = 24.12°; 6067 unique reflections
used, 3610 with I Ͼ 2σ(I), F(000) = 3520, µ = 1.189 mm–1, R1/wR2
[I Ͼ 2σ(I)] = 0.084/0.128, R1/wR2 (all data) = 0.158/0.149, good-
ness-of-fit on F2 = 1.128.
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4484–4485.
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Soc. 2004, 126, 14714–14715.
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Chem. Soc. 2005, 127, 1933–1945.
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[12] M. Schröder, in: Encyclopedia of Inorganic Chemistry (Ed.:
R. B. King), John Wiley & Sons, Chichester, England, 1994, 5,
pp. 2392–2412.
[Ni(ema)(µ-S,SЈ)Pd(dppe)]·1.5MeOH (4·1.5MeOH): C32H32N2-
NiO2P2PdS2·1.5(CH4O) M = 815.8; triclinic, space group P1, a =
¯
Eur. J. Inorg. Chem. 2005, 4527–4532
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4531

S. E. Duff, J. Elaine Barclay, S. C. Davies, P. B. Hitchcock, D. J. Evans
FULL PAPER
[13] W. Shin, P. A. Lindahl, J. Am. Chem. Soc. 1992, 114, 9718–
[15] J. DePriest, G. Y. Zheng, C. Woods, D. R. Rillema, N. A. Miki-
rova, M. E. Zandler, Inorg. Chim. Acta 1997, 264, 287–296.
Received: July 28, 2005
9719.
[14] H.-J. Krüger, G. Peng, R. H. Holm, Inorg. Chem. 1991, 30,
734–742.
Published Online: October 11, 2005
4532
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2005, 4527–4532