Preparation and molecular structures of the decanuclear diynyl-ruthenium-silver and -copper complexes [M6{μ3-C{triple bond, long}CC{triple bond, long}C[Ru(dppe)Cp*]}4(μ-dppm)2](BF4)2 (M = Ag, Cu)

Article abstract of DOI:10.1016/j.jorganchem.2010.03.016

Reactions between [M₂(dppm)₂(NCMe)₂]X₂ [M = Ag, X = ClO₄; M = Cu, X = BF₄] and Ru(C{triple bond, long}CC{triple bond, long}CM)(dppe)Cp* [M = Ag, Cu; generated in situ from Ru(C{triple bond, long}CC{triple bond, long}CH)(dppe)Cp* and AgNO₃ or CuCl(PPh₃), respectively] afford the cationic mixed-metal cluster diynyl complexes [M₆{μ₃-C{triple bond, long}CC{triple bond, long}C[Ru(dppe)Cp*]}₄(μ-dppm)₂]X₂, of which the structures were determined by single-crystal XRD studies. Electrochemical studies indicate that there is no interaction between the ruthenium centres. Reactions between [M₂(μ-dppm)₂(NCMe)₂](BF₄)₂ and Ru(C{triple bond, long}CC{triple bond, long}CM′)(dppe)Cp* (M,M′ = Cu, Ag) afforded a mixture of Ag_6-nCu_n clusters, as shown by ES-MS and crystallographic studies. Preliminary studies suggest that extensive disproportionation occurs in solution.

Full text of DOI:10.1016/j.jorganchem.2010.03.016

Journal of Organometallic Chemistry 695 (2010) 1569–1575
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Preparation and molecular structures of the decanuclear diynyl-ruthenium-silver
and -copper complexes [M6{
(M = Ag, Cu)
l3-C„CC„C[Ru(dppe)Cp*]}4(
l-dppm)2](BF4)2
b
c
d
a
Michael I. Bruce a, , Paul J. Low , Brian K. Nicholson , Brian W. Skelton , Natasha N. Zaitseva ,
*
Xiao-li Zhao a,1
a School of Chemistry and Physics, University of Adelaide, Adelaide, South Australia 5005, Australia
b Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, England, United Kingdom
c Department of Chemistry, University of Waikato, Hamilton, New Zealand
d Chemistry M313, SBBCS, University of Western Australia, Crawley, Western Australia 6009, Australia
a r t i c l e i n f o
a b s t r a c t
Article history:
Reactions between [M2(dppm)2(NCMe)2]X2 [M = Ag, X = ClO4; M = Cu, X = BF4] and Ru(C„CC„CM)(dp-
pe)Cp* [M = Ag, Cu; generated in situ from Ru(C„CC„CH)(dppe)Cp* and AgNO3 or CuCl(PPh3), respec-
Received 19 August 2009
Received in revised form 11 March 2010
Accepted 11 March 2010
Available online 16 March 2010
tively] afford the cationic mixed-metal cluster diynyl complexes [M6{
l3-C„CC„C[Ru(dppe)Cp*]}4(l-
dppm)2]X2, of which the structures were determined by single-crystal XRD studies. Electrochemical stud-
ies indicate that there is no interaction between the ruthenium centres. Reactions between [M2(l-
dppm)2(NCMe)2](BF4)2 and Ru(C„CC„CM0)(dppe)Cp* (M,M0 = Cu, Ag) afforded a mixture of Ag6ꢀnCun
clusters, as shown by ES-MS and crystallographic studies. Preliminary studies suggest that extensive dis-
proportionation occurs in solution.
Keywords:
Cluster
Diyne
Ó 2010 Elsevier B.V. All rights reserved.
Copper
Silver
Ruthenium
Structure
1. Introduction
dppm)2(NCMe)2]X2 ([2-M]X2: M = Cu, Ag; X = BF4, PF6) with
Re(C„CC6H2R2C„CH-4)(NN)(CO)3 (R = H, Me; NN = bpy, Me2bpy,
The formation of trinuclear copper(I) clusters in which the Cu–
Cu vectors are bridged by dppm ligands, and bearing a variety of
alkynyl groups capping the Cu3 clusters, has been known for over
But2bpy) afforded complexes [M3{
l
3-C„CC6H2R2C„C[Re(NN)-
-dppm)3]X2 [7] while similar complexes containing
diynyl spacers have also been described [8]. Under different reac-
tion conditions, hexanuclear diynyl complexes [Ag6{l3
C„CC„C[Re(NN)(CO)3]}4( -dppm)4](PF6)2 could be obtained [9].
(CO)3]}2(
l
a decade, the compounds [Cu3(
l
-dppm)3(
l
3-C„CR)n](X)3ꢀn having
-
been described by the groups of Gimeno and co-workers [1] and
Yam and co-workers [2]. Since that time, many other examples
have been described, including diynyl derivatives [3], extensive
studies resulting from the demonstration that some show unusual
luminescent behaviour. Some years later, Yam and coworkers de-
scribed analogous clusters containing silver(I) [4]. Tetranuclear
l
This Communication describes some related systems containing
ruthenium.
2. Results and discussion
complexes Cu4(
l
3-C„CR)4(PR03)4 have also been described [5], as
-dppm)4](BF4)2 [6].
The reaction of Ru(C„CC„CH)(dppe)Cp* (Cp* =
g-C5Me5) with
well as [Cu4( 4-C„C)(
l
l
AgNO3, in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene
(dbu) as base, affords a yellow insoluble, apparently non-explosive
Trinuclear alkynyl derivatives of Group 11 metals in which the
alkynyl is end-capped by other metal-ligand fragments have also
been described. For example, the reactions between [M2(l-
and
presumably
polymeric
material
of
composition
Ru(C„CC„CAg)(dppe)Cp* 1-Ag. The similar copper(I) analogue
1-Cu can be obtained from the reaction between
Ru(C„CC„CH)(dppe)Cp* and CuCl(PPh3) in the presence of
NaOMe. Both materials were characterised only on the basis of
their microanalyses and limited IR spectral data, the latter having
* Corresponding author. Tel.: +61 8 8303 4358.
E-mail addresses: mbruce@chemistry.adelaide.edu.au, michael.bruce@adelai-
de.edu.au (M.I. Bruce).
1
Present address: Shanghai Key Laboratory of Green Chemistry and Chemical
weak
1-Ag contains ions at m/z ca 1400 corresponding to [{Cp*(dppe)
m
(C„C) bands between 2025 and 2075 cmꢀ1. The ES–MS of
Processes, Department of Chemistry, East China Normal University, Shanghai 200062,
China.
0022-328X/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.03.016

1570
M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
RuC4}2]+ and [{Cp*(dppe)RuC4}2 + Ag]+, possibly arising from impu-
rities, together with some 3+ ions at m/z ca 7000, indicating very
high mass aggregates. Further studies of these systems are neces-
sary for full characterisation.
remained electrochemically and chemically irreversible at scan
rates up to 800 mV sꢀ1. Attempts to probe further the nature of
the oxidation processes were hampered by the instability of the re-
dox products on the longer timescale of spectro-electrochemical
experiments.
Nevertheless, we have used both compounds as sources of the
diynyl-ruthenium fragment in their reactions with [M2(
dppm)2(NCMe)2]2+ (M = Cu, Ag) (Scheme 1). The reaction between
Ru(C„CC„CAg)(dppe)Cp* 1-Ag and [Ag2( -dppm)2(NCMe)2]
(ClO4)2 [2-Ag](ClO4)2 was carried out in CH2Cl2/MeOH. Upon
work-up, crystalline [Ag6{ 3-C„CC„C[Ru(dppe)Cp*]}4( -dppm)2]
(ClO4)2 [3-Ag](ClO4)2 was obtained in 76% yield (Scheme 1). The
analogous Cu6Ru4 derivative [3-Cu](BF4)2 was obtained as a red
crystalline solid in 80% yield from the reaction between
l-
2.1. Molecular structures
l
Crystals of the 9MeCN-solvate of [3-Ag](ClO4)2 were obtained
from MeCN/diethyl ether, while a mixed CHCl3–C6H6 solvate of
[3-Cu](BF4)2 was isolated from a mixture of these solvents. Both
crystals proved suitable for XRD structure determinations. Fig. 1
is a plot of the cation [3-Ag]+, the copper analogue being similar.
Pertinent structural parameters are collected in Tables 1 and 2.
In the cation [3-Ag]2+, the core is a centrosymmetric distorted
octahedral Ag6 cluster (Fig. 2). Atom sets Ag(1)Ag(3a) and
Ag(1a)Ag(3) are each bridged by one dppm ligand [Ag(1)–P(5)
and Ag(3)–P(60) separations of 2.404(2), 2.411(2) Å, respectively]
leading to long Agꢁ ꢁ ꢁAg distances [3.5334(6) Å]. All other Agꢁ ꢁ ꢁAg
separations are in the range of 2.8104(8)–3.0056(9) Å, which are
shorter than the sum of van der Waals radii for Ag (3.4 Å) and
are thus suggestive of significant argentophilic interactions [11].
For [3-Cu]2+, a similar arrangement is found, with Cu(1)–P(5) and
Cu(3)–P(6) separations of 2.194(2), 2.222(2) Å, respectively, and
Cuꢁ ꢁ ꢁCu distances between 2.446(1) and 3.301(2) Å.
l
l
Ru(C„CC„CCu)(dppe)Cp* 1-Cu and [Cu2(l-dppm)2(NCMe)2]
(BF4)2 [2-Cu](BF4)2.
The IR spectra of [3-Ag](ClO4)2 and [3-Cu](BF4)2 contain med-
ium intensity (C„C) bands at 2039 (sh), 2003 (br) (Ag) or 2004
m
(sh), 1985 (br) cmꢀ1 (Cu), while NMR spectra contain appropriate
resonances for the Cp*, dppe and dppm ligands. In particular, the
31P NMR spectra contain single resonances for the dppe ligands
at dP 80.5 (Ag) or 79.3 (Cu), together with broad multiplets at dP
6.5 (Ag) or ꢀ6.6, ꢀ11.0 (Cu) for the dppm ligands. The electrospray
mass spectra (ES–MS), discussed further below, contain the parent
dications [M]2+ at m/z 2073.5 (Ag) or 1941 (Cu), together with
weak, presently unassigned, 3+ and 4+ ions and, for [3-Cu]2+, weak
peaks at lower mass corresponding to [{Cp*(dppe)RuC4}2]+ and
[{Cp*(dppe)RuC4}2 + Cu]+.
Four of the triangular faces of the M6 octahedron are capped by
atoms C(4), C(40), C(8), C(80) (where the prime refers to the centro-
symmetrically related atom) of the butadiynyl-ruthenium group in
A cyclic voltammetric study of [3-Ag](ClO4)2 showed only a sin-
gle quasi-reversible oxidation process at +1.29 V, with a second
irreversible wave at +2.02 V. This result is consistent with there
being no electronic communication between the four ruthenium
centres in [3-Ag]2+. Thus, insertion of the Ag6 unit into the Ru–
C4–C4–Ru fragment destroys the interaction found previously for
related Ru–C8–Ru systems [10].
The CV of [3-Cu](BF4)2 was dominated by a large, irreversible
anodic process from ca +0.38 V. The oxidation was accompanied
by significant fouling of the electrode, consistent with degradation
of the cluster core. The chemical stability of the redox products
was not enhanced at sub-ambient temperatures, and the process
an asymmetric l3,g
1-bridging mode [Ag(1,2,3)–C(4) 2.359(6),
2.075(6), 2.330(6); Ag(1,2,3)–C(8, or 80) 2.303(6), 2.109(6),
2.389(6); Cu(1,2,3)–C(4) 2.093(6), 1.900(6), 2.110(6); Cu(1,2,3)–
C(8, or 80) 2.075(6), 1.937(6), 2.043(6) Å]. The diynyl nature of
the carbon chain is shown by the short-long-short CC bond se-
quences [ranges 1.226(8)–1.240(8), 1.360(9), 1.365(8) (Ag),
1.224–1.231(8), 1.369(9), 1.372(9) (Cu)] which indicate that the
alternating C„C and C–C bonds are preserved in the chain. Angles
at C(1), C(2), C(3), and C(5), C(6), C(7) are close to linear [range
171.1(6)–179.8(7)°].
The geometries of the Ru(dppe)Cp* end-caps are similar to
those found in many related derivatives, with distances Ru–P
[2.269(2)–2.278(2) Å], Ru–C(Cp*) [2.228(7)–2.310(7) Å] and Ru–
C(diynyl) [1.965(6)–1.981(6) Å] and angles P–Ru–P [83.60(8)–
84.78(2)°] and P–Ru–C(diynyl) [82.0(2)–88.4(2)°], respectively.
These values may be compared to those found in
Ru(C„CC„CH)(dppe)Cp* [12]. There is no obvious contact be-
tween the four ruthenium centres, except that provided through
the Ag6 cluster via the diynyl links.
Cp*(dppe)Ru
M
[M2(µ-dppm)2(NCMe)2]2+
Cp*(dppe)Ru
Ru(dppe)Cp*
2+
Overall, the structure has some features in common with those
found
for [Ag6(l-dppm)4{l3-C„CC„C[Re(NN)(CO)3]}4](PF6)2
(NN = Me2bpy, Br2phen) [9], in which the central Ag6 unit has
Agꢁ ꢁ ꢁAg separations between 2.940(3)–3.007(3) and 3.0206(11)–
3.0415(10) Å, respectively. However, there are only two bridging
dppm ligands in [3-Ag]2+ and [3-Cu]2+. The extents of Mꢁ ꢁ ꢁM inter-
actions are not obvious from the structural determinations and
would require computational studies to establish.
M
P
Ph2
M
Ph2P
M
M
M
Ph2
PPh2
P
M
2.2. Mixed Ag/Cu complexes
In an effort to describe the reaction in more detail, we then
studied the reactions between the Ru(C„CC„CM0)(dppe)Cp* pre-
cursors 1-M0 and [M2(
l-dppm)2(NCMe)2](BF4)2 [2-M](BF4)2 (M,
Cp*(dppe)Ru
Ru(dppe)Cp*
M0 = Cu, Ag) using a stoichiometry that generated equal amounts
of M and M0 in solution. From these reactions, we obtained pale
yellow solids [4A]2+ (from [1-Cu]2+ + [2-Ag]2+) and [4B]2+ (from
[1-Ag]2+ + [2-Cu]2+) as the BF4 salts, each of which afforded crystals
M = Ag (3), Ag / Cu (4A, 4B)
Scheme 1. Synthesis of [M6{ 3-C„CC„C[Ru(dppe)Cp*]}4 (l .
-dppm)2]2+
l

M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
1571
C109
C211
C212
C222
C100
C221
C105
P2
C108
Ru1
C20
C10
C1
C112
C111
C612
C522
Ag2
C2
C102
C3
C521
C611
C107
C122
P1
C106
C4
C121
P5
P6
Ag3
Ag1
C621
C632
C8
C7
C322
C6
C321
P3
C206
C5
Ru2
C422
C421
C201
C207
C311
C312
P4
C411
C412
C209
Fig. 1. Plot of the cation in [Ag6{
l
3-C„CC„C[Ru(dppe)Cp*]}4(
l-dppm)2](ClO4)2 [3-Ag](ClO4)2.
Table 1
Core geometries (Å) for 3-Ag, 3-Cu, 4A and 4B.
Compound
3-Ag
3-Cu
4A
4B
Composition
Ag6
Cu6
Ag2.8Cu3.2
3.30
2.68
Ag3.1Cu2.9
3.45
2.59
Meq–Meq (dppm-bridged)
Meqꢁ ꢁ ꢁMeq (non-bridged)
Meq–Map (average)
3.53
2.81
2.96
3.30
2.45
2.67
Ag3
2.79
2.86
Ag2
C4
Table 2
Some bond distances (Å) and angles (°).
C8
Ag1
Cation
[3-Ag]2+
[3-Cu]2+
M(1)–P(5)
M(3)–P(6)
2.404(2)
2.411(2)
2.194(2)
2.222(2)
M(1)–C(4,8)
M(2)–C(4,80 )
M(3)–C(4,8)
C(1)–C(2)
2.359(6), 2.303(6)
2.075(6), 2.109(6)
2.330(6), 2.389(6)
1.239(8)
2.093(6), 2.075(6)
1.900(6), 1.937(6)
2.110(6), 2.043(6)
1.225(9)
P5
P6
C(2)–C(3)
1.365(8)
1.369(9)
C(3)–C(4)
C(5)–C(6)
C(6)–C(7)
1.230(8)
1.240(8)
1.360(8)
1.224(8)
1.225(8)
1.372(9)
Fig. 2. Plot of the core of [3-Ag]2+ showing Ag, P and C atoms only. The cores in [3-
Cu]2+, [4A]2+ and [4B]2+ are similar.
C(7)–C(8)
1.226(8)
1.231(9)
Ru(1)–C(1)–C(2)
Ru(2)–C(5)–C(6)
C(1)–C(2)–C(3)
C(2)–C(3)–C(4)
C(5)–C(6)–C(7)
C(6)–C(7)–C(8)
171.1(6)
176.8(5)
171.4(7)
179.8(7)
173.2(6)
178.5(7)
178.7(7)
171.0(6)
174.3(8)
179.4(8)
171.0(6
179.7(6)
Complexes [4A](BF4)2 and [4B](BF4)2 were also studied by sin-
gle-crystal X-ray analyses as their 8CH2Cl2 and 10MeCN solvates,
respectively. A plot of the dication [4A]2+ is shown in Fig. 3. The
cations are isostructural with [3-Ag]2+ and [3-Cu]2+ showing com-
mon features of distorted octahedral M6 clusters (M = Ag/Cu) in
which two Mꢁ ꢁ ꢁM vectors are bridged by dppm ligands and four
of the triangular faces of the octahedron are capped by the diy-
nyl-ruthenium fragments. The inter-Group 11 atom separations
are significantly different, as shown in Table 1.
Symmetry operation:1ꢀx, 1ꢀy, 1ꢀz.
suitable for structure determinations from CH2Cl2/hexane or MeCN /
Et2O, respectively (below).

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M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
C100
C221
P2
C211
C109
C105
Ru1
C112
C1
C2
C612
C611
C3
P1
C4
M2
P5
M3
P6
C122
C512
C621
C622
C8
C7
C322
C321
C6
C5
C40
C421
P3
C201
P4
C204
Ru2
C312
C412
C203
Fig. 3. Plot of the cation in [(Cu/Ag)6{C„CC„C[Ru(dppe)Cp*]}4(dppm)2](BF4)2 [4A](BF4)2.
The Ag/Cu atoms are not statistically placed at each of the sites
in the cluster core, rather the refinements for the products from 1-
Ag and 1-Cu converge with the fraction of Ag at the M(1,2,3) sites
being 0.403(6), 0.287(7), 0.721(6) in [4A]2+, and 0.287(1), 0.713(1),
0.577(1) in [4B]2+
, corresponding to compositions Ag2.8Cu3.2
([4A]2+) and Ag3.1Cu2.9 ([4B]2+). Strangely, the chemically equiva-
lent dppm-bridged equatorial sites M(1) and M(3) have very un-
equal occupancy values in each case (0.403/0.721 and 0.287/
0.577, respectively), while the unique apical site M(2) has the low-
est Ag contribution for [4A]2+ (0.287) but the largest for [4B]2+
(0.713). The overall composition deduced from the site occupancy
factors is supported by the M-M bond distances, with average val-
ues gradually decreasing from [3-Ag]2+ to [4B]2+ to [4A]2+ and fi-
nally, to [3-Cu]2+, as the fraction of the larger Ag decreases at the
expense of increasing Cu (Table 1), with longer bonds to compara-
ble sites of higher Ag contribution.
Electrospray mass spectra of solutions of [4A](BF4)2 and
[4B](BF4)2 in MeOH revealed that in each case, a mixture of com-
plexes containing Ag6ꢀnCun (n = 1 ꢀ 6) cores was present. Virtually
identical mass spectra were found for both [4A]2+ and [4B]2+
(Fig. 4). The highest mass ions of significance correspond to [M]2+
and are found between m/z 1940 and 2030, corresponding to com-
plexes with Cu6ꢀnAgn (n = 1–6) cores. However, the distribution is
not the statistical one expected from an equal Cu/Ag ratio. The
measured ratios are 0.03:0.34:1.00:0.80:0.14:0:0 for n = 0–6,
respectively, corresponding to an overall composition Cu3.7Ag2.3
for the products from each of the reactions. Clearly there is a bias
towards the inclusion of more Cu than expected on a purely statis-
tical basis, irrespective of whether it is added as diynyl 1-Cu or the
dppm-bridged dimer 2-Cu. Further, the overall compositions cal-
culated from the ion relative intensities differ significantly from
Fig. 4. ES mass spectrum (m/z 1900–2100) of [4A]2+ shows the distribution of core
compositions for the [(AgnCu6ꢀn){C4Ru(dppe)Cp*}4(dppm)2]2+ ions. The mass spec-
trum of [4B]2+ shows essentially the same relative intensities.
and Ag3.1Cu2.9 ([4B]2+). From the stoichiometry of the reaction mix-
ture, an Ag3Cu3 ratio might have been expected.
those obtained from the X-ray studies, namely Ag2.8Cu3.2 ([4A]2+
)

M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
1573
A possible explanation for the discrepancy is the occurrence of
redistribution reactions in solution. Further studies of the ES-MS
in MeCN as a function of time have given the following results:
tra. Electrospray mass spectra (ES–MS; positive-ion mode): Fisons
VG Platform II spectrometer. Solutions in MeOH were injected via a
10 ml injection loop; nitrogen was used as the drying and nebulis-
ing gas. Ions listed are the most intense peaks in the isotopic enve-
lope. CVs were recorded from solutions in CH2Cl2 ca 10ꢀ4 M in
analyte also containing 10ꢀ1 M [NBu4]BF4 in a gas-tight single-
compartment three-electrode cell equipped with platinum work-
ing, coiled platinum wire auxiliary and platinum wire pseudo-ref-
ꢂ Within the time of mixing, solutions of a mixture of [3-Ag]2+
and [3-Cu]2+ contain cluster ions corresponding to Cu6, AgCu5,
Ag2Cu4 and Ag3Cu3, the concentrations of the silver-rich ions
increasing on standing. However, no Ag4Cu2 ions are present
after ten minutes, although this species would have been
expected to form statistically.
ꢂ A solution of pre-prepared Ag4Cu2 cluster contains Ag5Cu and
Ag4Cu2, with lesser amounts of Ag3Cu3 and Ag6. After ten min-
utes, the spectra were more complex.
erence electrodes at scan rates of 50-800 mV sꢀ1
. All redox
potentials are reported vs SCE, with the FeCp*2/[FeCp*2]+ redox
couple (ꢀ0.07 V vs. SCE) used as internal reference. Data were col-
lected using a computer-interfaced EcoChemie PGSTAT-30 poten-
tiostat. Elemental analyses were performed by Campbell
Microanalytical Laboratory, University of Otago, Dunedin, New
Zealand.
These data suggest that these clusters are labile in solution,
with complex disproportionation reactions occurring, and in turn
provide an explanation for the broad resonances found in the 31P
NMR spectra. The differing compositions of materials studied by
XRD methods and ES-MS presumably reflect differing stoichiome-
tries of the isolated materials that were used in the separate
experiments.
4.3. Reagents
The compounds Ru(C„CC„CR)(dppe)Cp* (R = H, SiMe3) [12],
[Cu2(dppm)2(NCMe)2](BF4)2 [13], [Ag2(dppm)2(NCMe)2](ClO4)2
[14] and CuCl(PPh3) [15] were made by the cited methods.
4.4. Preparation of Ru(CꢃCCꢃCAg)(dppe)Cp* 1-Ag
3. Conclusions
To a solution of Ru(C„CC„CH)(dppe)Cp* (68.4 mg, 0.1 mmol)
in MeCN (15 mL) was added dbu (0.06 mL, 0.4 mmol), followed
by solid AgNO3 (34 mg, 0.2 mmol). The resulting suspension was
stirred overnight at r.t. before being filtered on a sintered glass fun-
nel and washed with MeCN (2 mL) to give yellow
Ru(C„CC„CAg)(dppe)Cp* 1-Ag which was dried under vacuum
Reactions between the Group 11 cations [M2(l-
dppm)2(NCMe)2]2+ (M = Ag, Cu) and the Ag and Cu derivatives of
the diynyl Ru(C„CC„CH)(dppe)Cp* have given a series of polynu-
clear complexes in which four C„CC„C{Ru(dppe)Cp*} fragments
and two dppm ligands are attached to a hexanuclear Group 11 me-
tal core. The stoichiometry requires addition of four Ag-diynyl frag-
ments to the disilver cation. Formation of the hexanuclear cation
may be envisaged as involving formation of the Ag6 assembly by
argentophilic combination of the precursor reagents 1 and 2, fol-
lowed by migration of the dppm ligands and capping of four Ag3
faces by the diynyl fragments.
(59 mg, 75%). IR/cmꢀ1
: m(C„CC„C) 2075m, 2045m. Anal. Calcd.
(C40H39AgP2Ru): C, 60.76; H, 4.94; Ag, 13.67. Found: C, 60.29; H,
5.01; Ag, 13.14%.
4.5. Preparation of Ru(C„CC„CCu)(dppe)Cp* 1-Cu
Differing compositions of solid materials isolated from mixed-
metal reactions, together with extended ES–MS studies, suggest
that rapid disproportionation of the complexes is occurring in solu-
tion. In this study, it has not been possible to determine how these
reactions occur, but scrambling processes of the ligands about the
central core may account for the almost identical compositions of
the two products obtained in the mixed-metal reactions. This pro-
cess may involve migration of the dppm ligands between Group 11
metal centres, or migration of the face-capping diynyl ligands, or
both.
To
a suspension of Ru(C„CC„CSiMe3)(dppe)Cp* (76 mg,
0.1 mmol) and CuCl(PPh3) (36 mg, 0.1 mmol) in THF (10 mL) was
added NaOMe (from 30 mg Na dissolved in 1 mL MeOH) to give a
deep red solution. The reaction mixture was stirred overnight at
r.t. The resulting light yellow precipitate was filtered under nitro-
gen, washed thoroughly with MeOH (2 mL) and dried under vac-
uum to give Ru(C„CC„CCu)(dppe)Cp* 1-Cu (55 mg, 73%). IR/
cmꢀ1
: m(C„CC„C) 2044w, 2025 w. Anal. Calcd. (C40H39CuP2Ru):
C, 64.38; H, 5.27. Found: C, 64.09; H, 5.43%.
4.6. Preparation of [Ag6{C„CC„C[Ru(dppe)Cp*]}4(dppm)2](ClO4)2 [3-
Ag](ClO4)2
4. Experimental
4.1. General experimental conditions
CAUTION: Appropriate care should be taken with reactions
involving perchlorates and poly-ynes.
All reactions were carried out under dry nitrogen using stan-
dard Schlenk techniques, although normally no special precautions
to exclude air were taken during subsequent workup. Common sol-
vents were dried, distilled under nitrogen, and degassed before
use.
Ru(C„CC„CAg)(dppe)Cp* (80 mg, 0.1 mmol) was added slowly
to [Ag2(dppm)2(MeCN)2](ClO4)2 (32 mg, 0.025 mmol) dissolved in
CH2Cl2–MeOH (1/1) (15 mL). After stirring overnight with exclu-
sion of light a clear deep red solution resulted. After evaporation
to dryness, the solid residue was extracted with MeCN and subse-
quent diffusion of Et2O vapour into the concentrated solution re-
sulted in the formation of yellow crystals of [Ag6{C„CC„
4.2. Instruments
C[Ru(dppe)Cp*]}4(dppm)2](ClO4)2ꢁ9MeCN
[3-Ag](ClO4)2ꢁ9MeCN
Infrared spectra: Bruker IFS28 FT-IR spectrometer. IR spectra
were obtained from samples in Nujol mulls mounted between NaCl
discs. NMR spectra: Varian ACP300 instrument (1H at 300.13 MHz,
31P at 121.503 MHz) at 298 K. Unless otherwise stated, samples
were dissolved in acetone-d6 (Aldrich) contained in 5 mm sample
tubes. Chemical shifts are given in ppm relative to internal tetra-
methylsilane for 1H spectra and external H3PO4 for 31P NMR spec-
(90 mg, 76%). Anal. Calcd. (C210H200Ag6Cl2O8P12Ru4.9MeCN): C,
58.08; H, 4.85; N, 2.67; M (cation), 4147. Found: C, 58.05; H,
4.68; N, 2.31%. IR/cmꢀ1 (C„CC„C) 2039 (sh), 2003m (br). 1H
: m
NMR: d 1.53 (s, 60H, Cp*), 2.11 (s, 27H, MeCN), 3.48-3.68 (m, 4H,
CH2-dppm), 2.09, 3.03 (16H, CH2-dppe), 7.07-7.84 (m, 120H, Ph);
31P NMR: d 80.5 (br s, dppe), 6.5 (br m, dppm). ES–MS/m/z:
2073.5, [Ag6(dppm)2{Ru(dppe)Cp*}4]2+
.

1574
M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
4.7. Preparation of [Cu6{C„CCvC[Ru(dppe)Cp*]}4(dppm)2](BF4)2 [3-
Cu](BF4)2
absorption corrections with No having I > 2r(I). Following solution
by direct methods, the structures were refined against F2. Aniso-
tropic displacement parameter forms were refined for the non-
A
similar reaction used Ru(C„CC„CCu)(dppe)Cp* (74 mg,
hydrogen atoms, (x, y, z, Uiso)H being included following a riding
0.1 mmol) and [Cu2(dppm)2(MeCN)2](BF4)2 (30 mg, 0.05 mmol).
After stirring overnight, solvent was removed from the clear dark
red solution and the residue was crystallized from CH2Cl2 to give
red [Cu6{C„CC„C[Ru(dppe)Cp*]}4(dppm)2](BF4)2 [3-Cu](BF4)2
(81 mg, 77%). Anal. Calcd. (C210H200B2Cu6F8P12Ru4): C, 62.21; H,
model. Neutral atom complex scattering factors were used; com-
putation used the SHELXL-97 program [16]. Pertinent results are gi-
ven in the Figures and in Tables 1–3.
4.97; M (cation), 3882. Found: C, 61.81; H, 5.01%. IR/cmꢀ1
:
5. Variata
m
(C„CC„C) 2004 (sh), 1985m (br); m
(BF) 1092m. 1H NMR: d
1.57 (s, 60H, Cp*), 3.66 (m, 4H, CH2-dppm), 2.10, 2.84 (2 ꢄ m,
16H, CH2-dppe), 6.94–8.00 (m, 120H, Ph); 31P NMR: d 79.3 (br s,
dppe), ꢀ6.6, ꢀ11.0 (2 ꢄ m, dppm). ES–MS/m/z: 1941,
[Cu6(dppm)2{Ru(dppe)Cp*}4]2+. X-ray quality crystals were grown
from CHCl3/C6H6.
[3-Ag](ClO4)2. Ph ring (62n) was found to be disordered over
two sets of sites with both components assigned occupancy factors
of 0.5 after trial refinement. Refinement of ring C42n with aniso-
tropic displacement factors gave unacceptable ellipsoids. A disor-
dered model gave two components with sof 0.85 and 1 ꢀ 0.85
with some of the atoms of the minor component unacceptably
close to solvent atoms. The atoms of this ring were therefore re-
fined with isotropic parameters. The site occupancy of solvent
MeCN(5) was set at 0.5 after trial refinement. Atoms of disordered
groups were refined with isotropic displacement parameters, with
both rings being refined as rigid bodies.
[3-Cu](BF4)2. One Ru(dppe)Cp* group is disordered over two sets
of sites with occupancies refined to 0.578(2) and its complement
(with the exception of one Ph group which is common to both
components). One Ph ring of the minor component was modeled
as being further disordered over two sets of sites and refined with
isotropic displacement parameters and with occupancies set equal
after trial refinement. The BF4 anion and solvent CHCl3 molecule
were similarly disordered. The solvent C6H6 molecule was refined
with occupancies set at 0.5 after trial refinement, with C atoms re-
fined with isotropic displacement parameters. Residual electron
density not modeled as either solvent was effectively removed
by use of the program SQUEEZE [17], resulting in a significant de-
crease in the R-factor.
4.8. Preparation of [(Ag/
Cu)6{C„CC„C[Ru(dppe)Cp*]}4(dppm)2](BF4)2 [4A and 4B]
These mixed-metal compounds were made in reactions similar
to that used for 2, using either Ru(C„CC„CCu)(dppe)Cp* and
[Ag2(dppm)2(MeCN)2](BF4)2 [to give [4A](BF4)2] or Ru(C„
CC„CAg)(dppe)Cp* and [Cu2(dppm)2(MeCN)2](BF4)2 [to give
[4B](BF4)2]. Both products formed yellow solids. Anal. for 4B only.
Calcd. (C210H200Ag3.1B2Cu2.9F8P12Ru4): C, 60.09; H, 4.77. Found: C,
59.91; H, 4.99%. IR/cmꢀ1 (C„CC„C) 1989w. 1H NMR: d 1.46 (s,
: m
60H, Cp*), 2.05, 2.81 (16H, CH2-dppe), 3.4-3.7 (m, 4H, CH2-dppm),
6.90–7.75 (m, 120H, Ph). 31P NMR: for 4A d 80.2 (br s, dppe), ꢀ2.8,
ꢀ10.9 (2 ꢄ m, dppm); for 4B d 79.8 (s, 8P, dppe) (dppm P not de-
tected). ES–MS/m/z: 1985, [Ag2Cu4(dppm)2{Ru(dppe)Cp*}4]2+
;
1963, [AgCu5(dppm)2{Ru(dppe)Cp*}4]2+
; 2029, [Ag4Cu2(dppm)2
{Ru(dppe)Cp*}4]2+; 2007, [Ag3Cu3(dppm)2{Ru(dppe)Cp*}4]2+
.
4.9. Structure determinations
[4A](BF4)2. Site occupancy factors for the Ag atoms at the mixed
Ag/Cu sites 1, 2 and 3 were found to be 0.403(6), 0.287(6) and
0.721(6), respectively, with the occupancies for the Cu atoms being
the complements.
Diffractometer data were measured using an Oxford Diffraction
Xcalibur ([3-Ag](ClO4)2, [4A](BF4)2, [4B](BF4)2; Mo K
a
radiation,
radiation,
k = 0.71073 Å) or Gemini ([3-Cu](BF4)2; Cu
Ka
k = 1.54178vÅ) CCD diffractometers at 100(2) K. Ntot reflections
were merged to N unique (Rint cited) after multi-scan or analytical
[4B](BF4)2. Site occupancy factors for the Ag atoms at the mixed
Ag/Cu sites 1, 2 and 3 were found to be 0.287(1), 0.713(1) and
Table 3
Crystal data and refinement details.
Complex
Formula
[3-Ag](ClO4)2ꢁ9MeCN
C210H200Ag6P12Ru4
ꢁ2ClO4ꢁ9C2H3N
4715.23
[3-Cu](BF4)2ꢁ2CHCl3ꢁC6H6
210H200Cu6P12Ru4.2BF4ꢁ2CHCl3ꢁC6H6
[4A](BF4)2ꢁ8CH2Cl2
C210H200(Ag2.82Cu3.18)P12Ru4
ꢁ2BF4ꢁ8CH2Cl2
4859.11
[4B](BF4)2ꢁ10MeCN
C210H200(Ag3.15Cu2.85)P12Ru4.2BF4
C
ꢁ10C2H3N
4604.84
Triclinic
Formula weight
Crystal system
Space group
a (Å)
b (Å)
c (Å)
4371.32
Triclinic
Triclinic
Triclinic
ꢀ
ꢀ
ꢀ
ꢀ
P1
P1
P1
P1
17.2375(9)
18.0414(8)
19.3672(6)
105.794(3)
92.668(3)
113.674(5)
5224
16.4015(8)
17.4036(7)
20.7303(6)
79.070(3)
89.119(3)
66.041(4)
5297
16.3895(5)
17.6167(4)
21.3267(7)
94.304(2)
107.006(3)
113.817(2)
5254
16.4269(5)
17.4036(4)
20.8055(4)
78.167(2)
88.749(2)
65.372(2)
5278
a
(°)
b (°)
c
(°)
Volume (Å3)
Z
1
1
1
1
qc (Mg mꢀ3
)
1.499
1.370
1.536
1.449
Crystal size (mm3)
l
0.21 ꢄ 0.17 ꢄ 0.16
0.12 ꢄ 0.04 ꢄ 0.02
0.29 ꢄ 0.26 ꢄ 0.05
0.26 ꢄ 0.20 ꢄ 0.13
(Mo K
a
) (mmꢀ1
)
1.007
4.883 (Cu-K
a)
1.205
0.997
F(0 0 0)
Tmin/max
Ntot
2394
0.90
35 274
2230
0.75/0.91
55 190
2459
0.75
66 926
2349
0.94
80 412
N (Rint
No
)
17 766 (0.050)
9282
18 764 (0.1092)
10 942
31 695 (0.043)
20 825
33 579 (0.045)
18 043
R1, wR2 [I > 2
R1, wR2 (all data)
T (K)
r
(I)]
0.0471, 0.1036
0.0922, 0.1138
100(2)
0.0612, 0.1568
0.1142, 0.1791
100(2)
0.0622, 0.1624
0.1003, 0.1777
100(2)
0.0478, 0.1030
0.0981, 0.1166
100 (2)

M.I. Bruce et al. / Journal of Organometallic Chemistry 695 (2010) 1569–1575
1575
(d) V.W.-W. Yam, W.K.-M. Fung, M.T. Wong, Organometallics 16 (1997) 1772;
(e) V.W.-W. Yam, W.K.-M. Fung, K.-K. Cheung, Chem. Commun. (1997) 963;
(f) V.W.-W. Yam, W.K.-M. Fung, K.-K. Cheung, J. Cluster Sci. 10 (1999) 37;
(g) V.W.-W. Yam, C.-H. Lam, K.-K. Cheung, Inorg. Chim. Acta 316 (2001)
19.
0.557(1), respectively, with the occupancies for the Cu atoms being
the complements.
Acknowledgements
[3] W.-Y. Lo, V.W.-W. Yam, N. Zhu, K.-K. Cheung, S. Fatallah, S. Messaoudi, B. Le
Guennic, S. Kahlal, J.-F. Halet, J. Am. Chem. Soc. 126 (2004) 7300.
PJL holds an EPSRC Leadership Fellowship. We thank the Aus-
tralian Research Council for support of this work and Johnson Mat-
they plc, Reading, UK, for a generous loan of RuCl3.nH2O.
[4] V.W.-W. Yam, W.K.-M. Fung, K.-K. Cheung, Organometallics 16 (1997) 2032.
See also Ref. [2e].
[5] (a) V.W.-W. Yam, W.-K. Lee, K.-K. Cheung, J. Chem. Soc., Dalton Trans. (1996)
2335;
(b) V.W.-W. Yam, S.K.W. Choi, C.L. Chan, K.-K. Cheung, J. Chem. Soc., Chem.
Commun. (1996) 2067.
Appendix A. Supplementary material
[6] (a) V.W.-W. Yam, W.K.-M. Fung, K.-K. Cheung, Angew. Chem. 108 (1996) 1213
(Angew. Chem., Int. Ed. Engl. 35 (1996) 1100).;
(b) W.-Y. Lo, C.-H. Lam, W.K.-M. Fung, H.-Z. Sun, V.W.-W. Yam, D. Balcells, F.
Maseras, O. Eisenstein, Chem. Commun. (2003) 1260.
[7] V.W.-W. Yam, W.K.-M. Fung, K.M.-C. Wong, V.C.-Y. Lau, K.-K. Cheung, Chem.
Commun. (1998) 777.
[8] V.W.-W. Yam, W.-Y. Lo, C.-H. Lam, W.K.-M. Fung, K.M.-C. Wong, V.C.-Y. Lau, N.
Zhu, Coord. Chem. Rev. 245 (2003) 39.
[9] V.W.-W. Yam, W.-Y. Lo, N. Zhu, Chem. Commun. (2003) 2446.
[10] (a) M.I. Bruce, B.D. Kelly, B.W. Skelton, A.H. White, J. Organomet. Chem. 604
(2000) 150;
CCDC 734433 [3-Ag](ClO4)2, 768209 [3-Cu](BF4)2, 734434
[4A](BF4)2 and 734432 [4B](BF4)2 contain the supplementary crys-
tallographic 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. Supplementary data associ-
ated with this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2010.03.016.
(b) M.I. Bruce, B.C. Hall, B.D. Kelly, P.J. Low, B.W. Skelton, A.H. White, J. Chem.
Soc., Dalton Trans. (1999) 3719.
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