Synthesis and reactivities of Ir2Ru heterobimetallic sulfido clusters derived from a hydrogensulfido-bridged diiridium complex

Article abstract of DOI:10.1039/a902999k

The hydrogensulfido-bridged diiridium complex [ClCp*Ir(μ-SH)₂IrCp*Cl] reacted with [RuH₂(PPh₃)₄] to give a mixed-metal trinuclear cluster with an Ir₂Ru(μ₃-S)₂ core [(Cp*Ir)₂(μ₃-S)₂RuCl ₂(PPh₃)] 2, which was further converted into the cationic diphosphine derivatives [(Cp*Ir)₂(μ₃-S)₂RuCl(L)]Cl (L = dppe = Ph₂PCH₂CH₂PPh₂ 3 or depe = Et₂PCH₂CH₂PEt₂ 4). The reaction of cluster 3 with Me₂CuLi followed by anion metathesis with KPF₆ afforded the cationic methyl cluster [(Cp*Ir)₂(μ₃-S)₂RuMe(dppe)][PF ₆] 5 in good yield, while treatment of 3 with CHCl₂Li led to selective formation of [(Cp*Ir){(η⁴-C₅Me₅CHCl ₂)Ir}(μ₃-S)₂RuCl(dppe)] 6, in which one of the Cp* ligands was alkylated by CHCl₂Li to form an η⁴-diene. Clusters 3 and 4 were also transformed into the dihydrido clusters [(Cp*Ir)₂(μ₃-S)₂(μ-H) ₂Ru(L)] (L = dppe 7 or depe 8) by the reaction with NaBH₄. On the other hand, cluster 2 was converted into the carbonyl cluster [(Cp*Ir)₂(μ₃-S)₂RuCl(CO)(PPh ₃)]Cl 9, the isocyanide clusters [(Cp*Ir)₂(μ₃-S)₂RuCl(CNXy)(PPh ₃)]Cl 10 (Xy = 2,6-C₆H₃Me₂) and [(Cp*Ir)₂(μ₃-S)₂Ru(CNXy) ₂(PPh₃)][BPh₄]₂ 11 and the co-ordinatively unsaturated thiolato clusters [(Cp*Ir)₂(μ₃-S)₂Ru(SAr)₂] (Ar = 2,4,6-C₆H₂Prⁱ₃ 12 or Xy 13) on treatment with CO, XyNC and LiSAr, respectively. The molecular structures of [(Cp*Ir)₂(μ₃-S)₂RuCl(depe)][BPh ₄] 4′, 5′CH₂Cl₂, 6, 7 and 12·2C₆H₆ were established by X-ray diffraction studies.

Full text of DOI:10.1039/a902999k

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Synthesis and reactivities of Ir2Ru heterobimetallic sulfido clusters
derived from a hydrogensulfido-bridged diiridium complex
Takuya Kochi,a Yasuo Nomura,a Zhen Tang,a Youichi Ishii,a Yasushi Mizobeb and
Masanobu Hidai*a
a Department of Chemistry and Biotechnology, Graduate School of Engineering,
The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
b Institute of Industrial Science, The University of Tokyo, Roppongi, Minato-ku,
Tokyo 106-8558, Japan. E-mail: hidai@chembio.t.u-tokyo.ac.jp
Received 15th April 1999, Accepted 17th June 1999
The hydrogensulfido-bridged diiridium complex [ClCp*Ir(µ-SH)2IrCp*Cl] reacted with [RuH2(PPh3)4] to give
a mixed-metal trinuclear cluster with an Ir2Ru(µ3-S)2 core [(Cp*Ir)2(µ3-S)2RuCl2(PPh3)] 2, which was further
converted into the cationic diphosphine derivatives [(Cp*Ir)2(µ3-S)2RuCl(L)]Cl (L = dppe = Ph2PCH2CH2PPh2 3
or depe = Et2PCH2CH2PEt2 4). The reaction of cluster 3 with Me2CuLi followed by anion metathesis with KPF6
afforded the cationic methyl cluster [(Cp*Ir)2(µ3-S)2RuMe(dppe)][PF6] 5 in good yield, while treatment of 3 with
CHCl2Li led to selective formation of [(Cp*Ir){(η4-C5Me5CHCl2)Ir}(µ3-S)2RuCl(dppe)] 6, in which one of the Cp*
ligands was alkylated by CHCl2Li to form an η4-diene. Clusters 3 and 4 were also transformed into the dihydrido
clusters [(Cp*Ir)2(µ3-S)2(µ-H)2Ru(L)] (L = dppe 7 or depe 8) by the reaction with NaBH4. On the other hand, cluster
2 was converted into the carbonyl cluster [(Cp*Ir)2(µ3-S)2RuCl(CO)(PPh3)]Cl 9, the isocyanide clusters [(Cp*Ir)2-
(µ3-S)2RuCl(CNXy)(PPh3)]Cl 10 (Xy = 2,6-C6H3Me2) and [(Cp*Ir)2(µ3-S)2Ru(CNXy)2(PPh3)][BPh4]2 11 and the
co-ordinatively unsaturated thiolato clusters [(Cp*Ir)2(µ3-S)2Ru(SAr)2] (Ar = 2,4,6-C6H2Pri3 12 or Xy 13) on
treatment with CO, XyNC and LiSAr, respectively. The molecular structures of [(Cp*Ir)2(µ3-S)2RuCl(depe)][BPh4]
4Ј, 5ؒCH2Cl2, 6, 7 and 12ؒ2C6H6 were established by X-ray diffraction studies.
Transition-metal complexes with sulfur-based ligands have
been attracting increasing interest,1 primarily because they
serve as models for biological systems2 and industrial metal
sulfide catalysts.3 Complexes of metals relevant to such systems,
most typically those of iron and molybdenum, have been exten-
sively investigated. In contrast, the chemistry of noble metal
complexes with sulfur ligands still remains much less exploited.
With the intention of developing complexes with robust and
reactive multimetallic sites, we have synthesized several types of
multinuclear Group 8–10 noble metal complexes with sulfido or
thiolato ligands.4 In fact, intriguing transformations of various
substrate molecules have been achieved on the multimetallic
centres of, for example, [Cp*RuCl(µ-SPri)2Ru(OH2)Cp*]-
[O3SCF3] (Cp* = η5-C5Me5)5 and [PdMo3(µ3-S)4(tacn)3Cl]-
[PF6]3 (tacn = 1,4,7-triazacyclononane).6 Inspired by these
results, we have embarked on establishing a general and rational
route for the construction of noble metal sulfido clusters with
designed structures. Recently, we have newly synthesized a
series of hydrogensulfido complexes [ClCp*M(µ-SH)2MCp*Cl]
(M = Ru,7 Rh8 or Ir8) and [Cp2Ti(µ-SH)2RuCp*Cl] (Cp = η5-
C5H5),4d and found that they can be used as versatile precursors
for the syntheses of homo- and hetero-metallic sulfido
clusters.4c–e,7,8 In particular, the hydrogensulfido complex of
iridium [ClCp*Ir(µ-SH)2IrCp*Cl] 1 is transformed into various
heterobimetallic clusters including trinuclear clusters with the
triangular Ir2M(µ3-S)2 core (M = Rh,8a Pd,8a,c Pt8c or Fe4e) and
pentanuclear clusters with the bow-tie type Ir4M(µ3-S)4 core
(M = Fe, Co or Ni)4e by reaction with a second metal fragment.
In addition, the trinuclear cluster [(Cp*Ir)2(µ3-S)2PdCl2] derived
from 1 exhibits unique regioselectivity in the addition of
alcohols to internal 1-aryl-1-alkynes.8c Now we have synthes-
ized mixed-metal trinuclear clusters with an Ir2Ru(µ3-S)2 core
[(Cp*Ir)2(µ3-S)2RuCl2(PPh3)] 2 and [(Cp*Ir)2(µ3-S)2RuCl(L)]Cl
(L = dppe = Ph2PCH2CH2PPh2 3 or depe = Et2PCH2CH2PEt2
4) from complex 1. Clusters 2, 3 and 4 displayed interesting
reactivities including regioselective alkylation of 3 either at the
ruthenium centre or at the Cp* ligand.
Results and discussion
Preparation of the trinuclear cluster [(Cp*Ir)2(ꢀ3-S)2RuCl2-
(PPh3)] 2 and its diphosphine derivatives 3 and 4
Reaction of complex 1 with an almost equimolar amount of
[RuH2(PPh3)4] in thf smoothly took place at room temperature
to give the mixed-metal trinuclear cluster 2 in good yield,
eqn. (1). Evolution of H2 gas (1.44 mol per 1) during the
H
Cp*
Cl
Ir
S
Ir
+ [RuH2(PPh3)4]
S
Cl
Cp*
H
(1)
1
Cp*
S
Ph3P
Ir
+ 2 H2 + 3 PPh3
Ru
Cl
Cl
Ir
S
Cp*
2
reaction was confirmed by GLC analysis of the gaseous phase,
suggesting that two molecules of H2 were formed per one of
cluster 2. As a related reaction, we have recently reported that
the diruthenium complex [ClCp*Ru(µ-SH)2RuCp*Cl] reacts
with [RuH2(PPh3)4] to give a triruthenium cluster with a
J. Chem. Soc., Dalton Trans., 1999, 2575–2582
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bridging hydrido ligand [(Cp*Ru)2(µ3-S)2(µ-H)RuCl(PPh3)2].4c
In the present reaction, however, cluster 2 was essentially the
1
sole product detected by the H NMR analysis of the crude
reaction mixture, and formation of hydrido clusters was not
observed. Cluster 2 could also be prepared from 1 and
[RuCl2(PPh3)3], but the reaction was sluggish (23% conversion
after 2 d at room temperature).
1
Cluster 2 was characterized by its H and 31P-{1H} NMR
spectra as well as the crystallographic study of its depe deriv-
ative described below. At room temperature, the 1H NMR
spectrum exhibited one Cp* singlet (δ 1.95) and aromatic
signals due to the PPh3 ligand with the intensity ratio of 2:1,
while the 31P-{1H} NMR signal appeared as a broad singlet at
δ 82.9. On lowering the temperature to Ϫ60 ЊC the Cp* signal in
the 1H NMR split into two singlets at δ 1.64 and 2.19 with the
same intensities. This NMR behavior indicates that the favored
conformer of the cluster at low temperatures has an unsym-
metric structure where the PPh3 ligand is located out of the
RuS2 plane, but the co-ordination around the ruthenium atom
is fluxional at room temperature to make the two Cp* ligands
apparently equivalent.
The Ir2RuS2 cluster core was further characterized as
diphosphine derivatives. Thus, on treatment with dppe or depe,
cluster 2 was converted into the cationic cluster 3 or 4, respect-
ively (Scheme 1), and the molecular structure of [(Cp*Ir)2-
Fig. 1 Structure of the cationic part in complex 4Ј. Hydrogen atoms
are omitted for clarity. Thermal ellipsoids are shown at the 50% prob-
ability level.
Table 1 Selected interatomic distances (Å) and angles (Њ) in complex 4Ј
R
R
Cl
Cp*
S
P
Ir
Ir(1)–Ir(2)
Ir(2)–Ru(1)
Ir(1)–S(2)
Ir(2)–S(2)
Ru(1)–S(1)
Ru(1)–P(1)
2.7848(6)
2.8437(9)
2.277(3)
2.290(3)
2.332(3)
2.295(3)
Ir(1)–Ru(1)
Ir(1)–S(1)
Ir(2)–S(1)
Ru(1)–Cl(1)
Ru(1)–S(2)
Ru(1)–P(2)
2.8922(9)
2.285(3)
2.291(3)
2.392(3)
2.261(3)
2.313(3)
dppe or depe
Ru
2
P
R
Ir
Cl
S
R
Cp*
3 R = Ph
4 R = Et
Ir(2)–Ir(1)–Ru(1)
Ir(1)–Ru(1)–Ir(2)
S(1)–Ir(2)–S(2)
Cl(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(1)
S(2)–Ru(1)–P(1)
60.08(2)
58.08(2)
88.41(9)
134.8(1)
101.5(1)
139.4(1)
Ir(1)–Ir(2)–Ru(1)
S(1)–Ir(1)–S(2)
Cl(1)–Ru(1)–S(1)
S(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(2)
S(2)–Ru(1)–P(2)
61.83(2)
88.90(9)
91.80(10)
88.11(9)
176.9(1)
89.7(1)
R
R
S
Cp*
H
Ir
P
P
NaBH4
Ru
Ir
H
S
cationic clusters exhibited no notable temperature dependence
in the 1H NMR spectra. Therefore, the cationic clusters 3 and 4
are considered to be much more fluxional than 2 with respect to
the geometry around the ruthenium atom.
Cp*
R
R
7 R = Ph
8 R = Et
Scheme 1
Regioselective alkylation reactions of cluster 3
(µ3-S)2RuCl(depe)][BPh4] 4Ј, the [BPh4]Ϫ analogue of 4, was
unequivocally established by X-ray analysis. An ORTEP9
drawing of the cation in 4Ј is illustrated in Fig. 1, and selected
bond distances and angles are listed in Table 1. Cluster 4Ј has a
triangular Ir2Ru core capped by two µ3-sulfido ligands from
both sides. The two Ir–Ru contacts at 2.8922(9) and 2.8437(9) Å
and the Ir–Ir contact at 2.7848(6) Å are consistent with Ir–Ru 10
and Ir–Ir4e,11 single bonds, respectively. The Ru(1) atom is
further co-ordinated by a chelating depe molecule and a chloro
ligand, and if the two Ir–Ru bonds are neglected the geometry
around the ruthenium atom is distorted trigonal bipyramidal
with the S(1) and P(2) atoms at the apical positions. This
geometry makes the molecule unsymmetric as a whole. The
Ru(1)–S(1) distance [2.332(3) Å] is appreciably longer than
Alkylation of cluster 3 was examined in detail. Although its
reactions with MeLi, PhLi and MeMgBr ended in the
formation of complex mixtures, selective methylation of the
ruthenium centre was achieved by the reaction with Me2CuLi at
1
Ϫ20 ЊC. The H NMR analysis of the crude product indicated
the formation of a single cluster species, and the cationic methyl
cluster [(Cp*Ir)2(µ3-S)2RuMe(dppe)][PF6]ؒCH2Cl2 5ؒCH2Cl2
was isolated in 67% yield after anion metathesis with KPF6
1
(Scheme 2). The H NMR spectrum of cluster 5 exhibited one
triplet at δ Ϫ1.14 [3 H, 3J(PH) = 6.4 Hz] assignable to the
RuMe protons and one singlet at δ 1.85 (30 H) due to the Cp*
protons, both of which are consistent with the formulation.
Attempted methylation of cluster 2 with Me2CuLi did not give
any isolable methyl clusters.
Ru(1)–S(2) [2.261(3) Å] probably due to the trans influence
11c,d
of the P(2) atom. Although several Ir3(µ3-S)2
S)2
and Ru3(µ3-
The molecular structure of complex 5ؒCH2Cl2 was deter-
mined by X-ray analysis. An ORTEP drawing of the cation
is given in Fig. 2, and important bond distances and angles are
in Table 2. Cluster 5 has a triangular Ir2Ru core capped by two
µ3-sulfido ligands, which is closely related to that of 4Ј. The
three metal–metal distances [Ir(1)–Ir(2), 2.7717(5); Ir(1)–Ru(1),
2.8695(8); Ir(2)–Ru(1), 2.978(1) Å] are diagnostic of metal–
metal bonding interactions, where the elongation of the Ir(2)–
Ru(1) bond is attributed to the steric congestion between the
4c,12
clusters with related structures have been reported, the
mixed-metal Ir2Ru(µ3-S)2 core is unprecedented.
At room temperature, each of complexes 3, 4 and 4Ј showed
1
one Cp* signal (δ 1.88 for 3; 2.11 for 4; 1.99 for 4Ј) in the H
NMR spectrum, although the cation in 4Ј takes the unsym-
metric solid state structure as described above. Their 31P-{1H}
NMR spectra also displayed only one sharp singlet (δ 81.0 for 3;
82.3 for 4 and 4Ј). Furthermore, in contrast to cluster 2, these
2576
J. Chem. Soc., Dalton Trans., 1999, 2575–2582

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Fig. 3 Molecular structure of complex 6. Details as in Fig. 1.
Table 3 Selected interatomic distances (Å) and angles (Њ) in complex 6
Fig. 2 Structure of the cationic part in complex 5ؒCH2Cl2. Details as in
Fig. 1.
Ir(1)–Ir(2)
Ir(2)–Ru(1)
Ir(1)–S(2)
2.8604(5)
2.9740(9)
2.278(2)
2.274(2)
2.128(10)
2.16(1)
2.363(3)
2.287(3)
1.43(1)
Ir(1)–Ru(1)
Ir(1)–S(1)
Ir(2)–S(1)
Ir(2)–C(11)
Ir(2)–C(13)
Ru(1)–Cl(1)
Ru(1)–S(2)
Ru(1)–P(2)
C(11)–C(15)
C(13)–C(14)
2.8199(9)
2.294(2)
2.285(2)
2.159(10)
2.13(1)
2.428(2)
2.296(2)
2.274(3)
1.52(1)
Table 2 Selected interatomic distances (Å) and angles (Њ) in complex
5ؒCH2Cl2
Ir(2)–S(2)
Ir(2)–C(12)
Ir(2)–C(14)
Ru(1)–S(1)
Ru(1)–P(1)
C(11)–C(12)
C(12)–C(13)
C(14)–C(15)
Ir(1)–Ir(2)
Ir(2)–Ru(1)
Ir(1)–S(2)
Ir(2)–S(2)
Ru(1)–S(2)
Ru(1)–P(2)
2.7717(5)
2.978(1)
2.273(2)
2.276(2)
2.295(2)
2.277(3)
Ir(1)–Ru(1)
Ir(1)–S(1)
Ir(2)–S(1)
Ru(1)–S(1)
Ru(1)–P(1)
Ru(1)–C(21)
2.8695(8)
2.284(3)
2.288(2)
2.328(2)
2.266(3)
2.147(9)
1.46(1)
1.41(1)
1.55(1)
Ir(2)–Ir(1)–Ru(1)
Ir(1)–Ru(1)–Ir(2)
S(1)–Ir(2)–S(2)
S(1)–Ru(1)–P(1)
S(1)–Ru(1)–C(21)
S(2)–Ru(1)–P(2)
63.71(2)
56.55(2)
87.52(8)
176.05(10)
95.4(3)
Ir(1)–Ir(2)–Ru(1)
S(1)–Ir(1)–S(2)
S(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(2)
S(2)–Ru(1)–P(1)
S(2)–Ru(1)–C(21)
59.74(2)
87.70(9)
86.10(9)
100.24(9)
91.75(9)
125.9(3)
Ir(2)–Ir(1)–Ru(1)
Ir(1)–Ru(1)–Ir(2)
S(1)–Ir(2)–S(2)
Cl(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(1)
S(2)–Ru(1)–P(1)
C(12)–C(11)–C(15)
C(12)–C(13)–C(14)
C(11)–C(15)–C(14)
63.14(2)
59.10(2)
87.92(9)
136.12(9)
173.32(9)
90.71(9)
108(1)
Ir(1)–Ir(2)–Ru(1)
S(1)–Ir(1)–S(2)
57.77(2)
87.61(8)
89.33(8)
85.55(8)
103.44(9)
141.38(10)
106.0(10)
108.0(9)
Cl(1)–Ru(1)–S(1)
S(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(2)
S(2)–Ru(1)–P(2)
C(11)–C(12)–C(13)
C(13)–C(14)–C(15)
146.86(9)
107(1)
95.5(8)
Ph Ph
PF6
Cp*
S
S
P
Ir
6, which was isolated as dark brown crystals in 57% yield
Ru
Me
P
Ph
(Scheme 2). Formation of no other cluster species was observed
Ir
1
by the H NMR analysis of the crude reaction mixture, indi-
Ph
Cp*
(i) Me2CuLi
(ii) KPF6
1
cating that cluster 6 was produced quite selectively. The H
5
NMR spectrum of cluster 6 showed a set of singlets at δ 1.21
(3 H), 1.79 (6 H), 1.95 (6 H) and 5.23 (1 H) due to the η4-
C5Me5CHCl2 ligand, which revealed that one of the Cp*
ligands in 3 was alkylated by CHCl2Li to form the substituted
η4-cyclopentadiene ligand. This type of conversion of a Cp*
ligand into a substituted η4-cyclopentadiene ligand has been
relatively rare.13 Very recently, Tanaka et al.13c have reported
that the trinuclear cluster [(Cp*Ir)3(µ3-S)2], which is generated
by electrochemical reduction of [(Cp*Ir)3(µ3-S)2][BPh4]2, reacts
with MeCN under CO2 to give a cationic cluster with a sub-
stituted η4-cyclopentadiene ligand [(Cp*Ir)2{(η4-C5Me5CH2-
CN)Ir}(µ3-S)2][BPh4], although the reaction mechanism has not
been clarified.
3
Ph Ph
P
Cp*
S
CHCl2Li
Ir
Ru
Cl
P
Ph
Ir
S
Ph
CHCl2
6
Scheme 2
The molecular structure of cluster 6 was further confirmed
by X-ray diffraction study. An ORTEP drawing is illustrated in
Fig. 3, and selected bond distances and angles are contained in
Table 3. The metric features of the Ir2Ru(µ3-S)2 core in 6 are
similar to those found in 5ؒCH2Cl2 except that the Ir(1)–Ir(2)
bond in 6 [2.8604(5) Å] is elongated. The η4 co-ordination of
the newly formed C5Me5CHCl2 ligand with the Ir(2)–C bond
distances at 2.128(10)–2.16(1) Å has been confirmed. The Ir(2)
atom is now co-ordinated by the two sulfur atoms and the diene
phenyl groups on the P(2) atom and the Cp* ligand on the Ir(2)
atom. It has unambiguously been confirmed that a methyl
ligand [C(21)] is introduced onto the ruthenium centre. The
geometry around the Ru(1) atom is distorted trigonal bipy-
ramidal with the P(1) and S(1) atoms at the apical positions and
the P(2), S(2) and C(21) atoms on the basal plane.
In contrast, treatment of cluster 3 with CHCl2Li led to
formation of [(Cp*Ir){(η4-C5Me5CHCl2)Ir}(µ3-S)2RuCl(dppe)]
J. Chem. Soc., Dalton Trans., 1999, 2575–2582
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ligand with a square planar geometry. This structure suggests
that the Ir(2) atom is reduced to the formal oxidation state of
IrI on reaction with CHCl2Li. On the other hand, the structure
around the ruthenium atom is trigonal bipyramidal and closely
related to that of cluster 4Ј.
The diffraction study of complex 6 has also revealed that the
CHCl2 group in the η4-C5Me5CHCl2 ligand is located at the
exo position. A mechanism consistent with the structure would
involve direct nucleophilic attack of CHCl2Li at the Cp* ligand
in the cationic cluster 3 from the outer co-ordination sphere,13a,b
since indirect attack of a CHCl2 group via the iridium centre to
the Cp* ring is expected to lead to the endo η4-C5Me5CHCl2
isomer.14 Alternatively, a mechanism involving the coupling
of a CHCl2 radical and the neutral cluster [(Cp*Ir)2(µ3-S)2-
RuCl(dppe)] formed by one electron transfer between CHCl2Li
and 3 may be operative.15 It should be pointed out that the
reaction site of 3 attacked by an alkylmetal reagent is highly
dependent upon the nature of the reagent. We consider that soft
and sterically small alkylmetals are driven to attack the
ruthenium centre, while sterically demanding alkylmetals tend
to attack the Cp* ligand.
Preparation of dihydrido clusters from 3 and 4
Fig. 4 Molecular structure of complex 7. Details as in Fig. 1.
Table 4 Selected interatomic distances (Å) and angles (Њ) in complex 7
The regioselective alkylation reactions observed with cluster 3
led us to investigate the reactions of 2, 3 and 4 with a hydride
reagent for comparison. When cluster 3 was allowed to react
with an excess amount of NaBH4 in CH2Cl2–ethanol at room
temperature the dihydrido cluster [(Cp*Ir)2(µ3-S)2(µ-H)2Ru-
(dppe)] 7 was obtained in moderate yield (Scheme 1). Cluster 4
was analogously converted into the corresponding dihydrido
cluster [(Cp*Ir)2(µ3-S)2(µ-H)2Ru(depe)] 8. However, no char-
acterizable hydrido cluster was obtained from 2.
Ir(1) ؒ ؒ ؒ Ir(2)
Ir(2)–Ru(1)
Ir(1)–S(2)
3.509(1)
2.790(2)
2.336(7)
2.288(6)
2.393(6)
2.242(6)
3.568(2)
2.798(2)
2.307(6)
2.352(6)
2.397(6)
2.230(6)
Ir(1)–Ru(1)
Ir(1)–S(1)
Ir(2)–S(1)
Ru(1)–S(1)
Ru(1)–P(1)
2.830(2)
2.336(6)
2.315(7)
2.413(6)
2.236(6)
Ir(2)–S(2)
Ru(1)–S(2)
Ru(1)–P(2)
Ir(3) ؒ ؒ ؒ Ir(4)
Ir(4)–Ru(2)
Ir(3)–S(4)
Ir(4)–S(4)
Ru(2)–S(4)
Ru(2)–P(4)
Ir(3)–Ru(2)
Ir(3)–S(3)
Ir(4)–S(3)
Ru(2)–S(3)
Ru(2)–P(3)
2.793(2)
2.314(7)
2.350(6)
2.420(6)
2.242(6)
1
In the H NMR spectrum cluster 7 exhibited a high-field
hydrido resonance at δ Ϫ14.73 with the intensity of 2 H as a
triplet by coupling with two equivalent phosphorus nuclei
[2J(PH) = 13.4 Hz] as well as one Cp* signal at δ 1.97 (30 H). No
temperature dependence was observed for these signals over the
range 20 to Ϫ80 ЊC. The 31P-{1H} NMR spectrum also showed
only one singlet, confirming the apparent equivalence of the
phosphorus nuclei. The IR spectrum had no absorption in
the range 1500–2200 cmϪ1 attributable to a terminal M–H
stretching. Considering these spectral data, cluster 7 is deduced
to have two hydrido ligands which bridge the two respective
Ru–Ir edges. Cluster 8 showed a hydrido signal at δ Ϫ14.56 as a
Ir(1)–Ru(1)–Ir(2)
S(1)–Ir(2)–S(2)
S(1)–Ru(1)–P(1)
S(2)–Ru(1)–P(1)
Ir(3)–Ru(2)–Ir(4)
S(3)–Ir(4)–S(4)
S(3)–Ru(2)–P(3)
S(4)–Ru(2)–P(3)
77.26(6)
80.4(2)
98.4(2)
170.2(2)
79.31(6)
77.9(2)
101.3(2)
173.4(2)
S(1)–Ir(1)–S(2)
S(1)–Ru(1)–S(2)
S(1)–Ru(1)–P(2)
S(2)–Ru(1)–P(2)
S(3)–Ir(3)–S(4)
S(3)–Ru(2)–S(4)
S(3)–Ru(2)–P(4)
S(4)–Ru(2)–P(4)
78.9(2)
76.3(2)
176.5(2)
101.1(2)
79.6(2)
75.8(2)
172.7(2)
98.4(2)
1
triplet [2J(PH) = 15.9 Hz] in the H NMR spectrum but no IR
absorption assignable to a terminal M–H stretching, revealing a
structure similar to that of 7.
valence electrons of 7. As a related dihydrido cluster, we have
recently synthesized [(Cp*Ru)2(µ3-S)2(µ-H)RuH(PPh3)2] by
treatment of [(Cp*Ru)2(µ3-S)2(µ-H)RuCl(PPh3)2] with NaBH4
and revealed its molecular structure with one terminal and one
bridging hydrido ligand.4c In cluster 7 the large Ir–Ru–Ir angle
probably enables both hydrido ligands to take bridging posi-
tions without deforming the H–Ru–H moiety from the ideal
linear geometry.
The molecular structure of complex 7 was established by
X-ray analysis. The unit cell contains two independent mol-
ecules, whose structures are essentially equivalent. An ORTEP
drawing for one is depicted in Fig. 4, and important bond dis-
tances and angles are collected in Table 4. The Ir–Ru distances
at an average of 2.803 Å are shorter than those found in clusters
4Ј, 5ؒCH2Cl2 and 6 and suggest that there exists substantial
metal–metal bonding character between the ruthenium and
iridium atoms. Although the positions of the hydrido ligands
could not be determined crystallographically, each of these
Ir–Ru edges is considered to be bridged by a hydrido ligand on
the basis of the above mentioned spectroscopic data. The
geometry around the ruthenium atom is viewed as distorted
octahedral with the mutually trans µ-hydrido ligands, if the
Ru–Ir interactions are neglected. On the other hand, the Ir–Ir
separation in each independent cluster molecule [3.509(1),
3.568(2) Å] is much longer than those of 4Ј, 5ؒCH2Cl2 and 6
and is regarded to be non-bonding. The loss of the Ir–Ir bond
makes the Ir–Ru–Ir bond angle [77.26(6), 79.31(6)Њ] signifi-
cantly larger than the corresponding values found in 4Ј,
5ؒCH2Cl2 and 6 [56.55(2)–59.10(2)Њ]. The structure with the two
metal–metal bonding contacts is in good agreement with the 50
Ligand substitution reactions of cluster 2
In addition to the reactions with diphosphine ligands, cluster 2
underwent several ligand substitution reactions. Treatment with
CO (1 atm) at room temperature gave the cationic carbonyl
cluster
[(Cp*Ir)2(µ3-S)2RuCl(CO)(PPh3)]Clؒ0.5CH2Cl2
9ؒ
0.5CH2Cl2 (Scheme 3). The 1H NMR spectrum showed a broad
singlet due to the Cp* ligands at δ 2.14, and the IR spectrum
one strong absorption assigned to the ν(CO) at 1929 cmϪ1. No
further reaction with CO took place even after a long time. In
contrast, when 2 was allowed to react with XyNC (Xy = 2,6-
C6H3Me2), stepwise ligand substitution was observed. Thus,
treatment of 2 with 1 equivalent of XyNC afforded the mono-
cationic cluster [(Cp*Ir)2(µ3-S)2RuCl(CNXy)(PPh3)]Cl 10,
whereas the 1H NMR analysis of the reaction mixture obtained
2578
J. Chem. Soc., Dalton Trans., 1999, 2575–2582

View Article Online
Cl
Cp*
S
S
Ph3P
Cl
Ir
Ru
Cl
Cp*
Ir
S
S
C
Ph3P
Cl
Ir
Cp*
O
Ru
9
Ir
C
N
Cp*
CO
Xy
XyNC
10
2
XyNC (2.5 equivalents)
NaBPh4
[BPh4]2
Cp*
S
Ph3P
Ir
Ru
C
N
Xy
Ir
LiSAr
C
S
N
Cp*
Xy
11
S
S
Cp*
Ir
ArS
ArS
Ru
Ir
Fig. 5 Molecular structure of complex 12ؒ2C6H6. Solvating benzene
molecules and hydrogen atoms are omitted for clarity. Thermal ellips-
oids are shown at the 50% probability level.
Cp*
12 Ar = Tip
13 Ar = Xy
Table 5 Selected interatomic distances (Å) and angles (Њ) in complex
12ؒ2C6H6
Scheme 3
Ir(1)–Ir(2)
Ir(2)–Ru(1)
Ir(1)–S(2)
Ir(2)–S(2)
Ru(1)–S(2)
Ru(1)–S(4)
2.7518(8)
2.833(1)
2.285(4)
2.279(5)
2.202(4)
2.271(4)
Ir(1)–Ru(1)
Ir(1)–S(1)
Ir(2)–S(1)
Ru(1)–S(1)
Ru(1)–S(3)
2.976(1)
2.283(4)
2.275(5)
2.223(4)
2.276(3)
by treatment of 2 with 2.5 equivalents of XyNC suggested that
both of the chloro ligands in 2 were substituted by the XyNC
ligands. Anion metathesis of the latter product with NaBPh4
led to isolation of the dicationic cluster [(Cp*Ir)2(µ3-S)2Ru-
(CNXy)2(PPh3)][BPh4]2ؒCH2Cl2 11ؒCH2Cl2. Cluster 10 exhib-
ited one IR band attributable to the ν(CN) at 2054 cmϪ1. On the
other hand, two ν(CN) bands were observed with cluster 11
at higher wavenumbers (2106 and 2135 cmϪ1), reflecting its
dicationic nature.
During the above reactions with CO and XyNC the PPh3
ligand on the ruthenium atom in complex 2 remains intact.
However, substitution of the two chloro ligands on the
ruthenium centre by more bulky anionic ligands is expected to
give co-ordinatively unsaturated clusters by sterically induced
dissociation of the PPh3 ligand. Actually, reactions of cluster 2
with lithium salts of sterically demanding 2,6-substituted
arenethiolate anions such as TipSϪ (Tip = 2,4,6-C6H2Pri3) and
XySϪ yielded [(Cp*Ir)2(µ3-S)2Ru(SAr)2] (Ar = Tip 12 or Xy 13)
(Scheme 3).
The molecular structure of complex 12ؒ2C6H6 disclosed by
X-ray diffraction study is illustrated in Fig. 5, and selected bond
distances and angles are collected in Table 5. The trinuclear core
with three metal–metal bonds and two µ3-S ligands is retained.
Although this cluster has 46 valence electrons and can be
regarded as co-ordinatively unsaturated, the structure of the
Ir2Ru(µ3-S)2 core is very close to that of the 48eϪ cluster 5
except that the Ru–(µ3-S) bond distances in 12ؒ2C6H6 [2.202(4),
2.223(4) Å] are shorter by 0.09–0.10 Å. The ruthenium atom is
tetrahedrally co-ordinated by the four sulfur atoms, and the
three metal atoms and the two sulfur atoms of the STip ligands
are nearly coplanar. The two aromatic rings of the Tip groups
are oriented almost perpendicular to this Ir2RuS2 plane
(dihedral angles, 88.4 and 80.3Њ). Interestingly, the STip ligands
are arranged in a highly unsymmetric conformation. Thus, the
Tip group attached to the S(4) atom is directed away from the
(Cp*Ir)2(µ3-S)2 moiety, while that connected to the S(3) atom is
located close to the Cp* ligand on the Ir(1) atom. At the same
time, the Ir(1)–Ru(1)–S(3) angle [123.69(10)Њ] is significantly
larger than the Ir(2)–Ru(1)–S(4) angle [92.7(1)Њ]. This charac-
Ir(2)–Ir(1)–Ru(1)
Ir(1)–Ru(1)–Ir(2)
Ir(2)–Ru(1)–S(4)
S(1)–Ir(2)–S(2)
S(1)–Ru(1)–S(3)
S(2)–Ru(1)–S(3)
S(3)–Ru(1)–S(4)
59.14(3)
56.48(3)
92.7(1)
Ir(1)–Ir(2)–Ru(1)
Ir(1)–Ru(1)–S(3)
S(1)–Ir(1)–S(2)
S(1)–Ru(1)–S(2)
S(1)–Ru(1)–S(4)
S(2)–Ru(1)–S(4)
64.38(3)
123.69(10)
84.7(1)
88.1(1)
107.9(2)
118.9(2)
85.0(1)
134.5(2)
122.0(2)
87.8(1)
teristic conformation minimizes the steric congestion between
the STip ligands and the Cp* ligands. In fact, unusually short
non-bonding contacts are observed between the S(4) and C(19)
(Cp* methyl) atoms (3.48 Å) and between the C(6) (Cp*
methyl) atom and the C(21)–C(26) aromatic ring (3.43 Å), both
of which are shorter than the sums of the van der Waals radii of
a methyl group (2.0 Å) and a sulfur (1.85 Å) or aromatic carbon
atom (1.7 Å).16 In particular, the latter distance suggests the
presence of an attractive interaction between the methyl group
and the aromatic ring, i.e., CH ؒ ؒ ؒ π interaction.17
The 1H NMR spectrum of complex 12 showed notable
temperature dependence. At room temperature one broad
signal at δ 1.99 attributable to Cp* ligands was observed,
which split into two broad signals at δ 1.63 and 2.27 on cooling
at Ϫ40 ЊC. This behavior can be accounted for by considering
the conformational interchange of the STip ligands which
are arranged in an unsymmetric structure as disclosed by the
crystallographic study, eqn. (2).
Cp*
Ar
S
Cp*
Ir
Ir
Ar
S
Ir
Ir
S
Ru
(2)
S
S
Ru
S
S
S
Ar
Cp*
Ar
Cp*
J. Chem. Soc., Dalton Trans., 1999, 2575–2582
2579

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temperature for 24 h. The solvent was removed in vacuo, and
Conclusion
the residual solid extracted with CH2Cl2. The CH2Cl2 solution
was concentrated to 5 cm3 and thf (0.3 cm3) added. Slow
diffusion of hexane (10 cm3) into the solution afforded 4Ј (6 mg,
0.004 mmol, 10% yield) as dark brown crystals (Found: C,
47.06; H, 5.53. C54H74BClIr2P2RuS2 requires C, 46.96; H,
5.40%). δH(CDCl3) 1.00 [6 H, dt, 3J(PH) 14.5, 3J(HH) 7.6,
CH2Me], 1.25 [6 H, dt, 3J(PH) 17.2, 3J(HH) 7.6, CH2Me],
1.35–1.48 (2 H, m, CH2), 1.66–1.90 (6 H, m, CH2), 1.99 (30 H, s,
Cp*), 2.05–2.12 (4 H, m, CH2), 6.87 [4 H, t, 3J(HH) 7.3, BPh4],
We have synthesized novel mixed-metal sulfido clusters 2, 3 and
4 with the Ir2Ru(µ3-S)2 core by using the dinuclear hydrogen-
sulfido complex 1 as the synthetic precursor. These clusters
exhibited various reactivities including the regioselective alkyl-
ation of cluster 3 at either the ruthenium centre or the Cp*
ligand. Clusters 5, 6, 7 and 8 have relatively labile or reactive
ligands such as methyl, diene and hydrido ligands, and further
reactions of these clusters as well as of the unsaturated clusters
12 and 13 are now under investigation.
3
7.03 [8 H, t, J(HH) 7.4 Hz, BPh4] and 7.38–7.44 (8 H, m,
BPh4). δP(CDCl3) 82.3 (s).
Experimental
[(Cp*Ir)2(ꢀ3-S)2RuMe(dppe)][PF6]ؒCH2Cl2 5ؒCH2Cl2. To a
thf (20 cm3) solution of Me2CuLi prepared from CuI (111 mg,
0.58 mmol) and MeLi (1.16 mmol, in ether) at Ϫ20 ЊC was
added complex 3 (500 mg, 0.388 mmol) at this temperature, and
the mixture kept at Ϫ20 ЊC for 1.5 h with stirring. Hexane (50
cm3) was added dropwise to the resulting dark brown mixture,
and the dark brown powder precipitated was collected by fil-
tration, washed with hexane and dried in vacuo. This crude
product was dissolved in thf (30 cm3) and KPF6 (714 mg, 3.88
mmol) added. The mixture was stirred at room temperature for
15 h and the solvent then removed in vacuo. The resulting dark
brown solid was extracted with CH2Cl2. Addition of hexane to
the concentrated CH2Cl2 solution afforded 5ؒCH2Cl2 (383 mg,
0.262 mmol, 67% yield) as dark brown crystals (Found: C,
39.28; H, 3.99. C48H59Cl2F6Ir2P3RuS2 requires C, 39.39; H,
All manipulations were carried out under an atmosphere of
nitrogen by the use of standard Schlenk tube techniques.
Solvents were dried by common procedures and distilled
before use. Complex 1,8a,b [RuH2(PPh3)4],18 [RuCl2(PPh3)3]19
and TipSH20 were prepared according to literature methods.
Lithium thiolates were prepared by reactions of BunLi with the
corresponding thiols. Other reagents were commercially
obtained and used as received. The IR spectra were recorded on
a Shimadzu 8100M spectrometer, H (270 MHz) and 31P-{1H}
1
NMR (109 MHz) spectra on a JEOL EX-270 spectrometer.
Hydrogen gas evolution was determined by GLC analysis using
a Shimadzu GC-8A gas chromatograph equipped with a
molecular sieve 13X column. Elemental analyses were per-
formed on a Perkin-Elmer 2400II CHN analyser. Amounts of
the solvent molecules in the crystals were determined not only
by elemental analyses but also by 1H NMR spectroscopy.
3
4.06%). δH(CDCl3) Ϫ1.14 [3 H, t, J(PH) 6.4 Hz, RuMe], 1.85
(30 H, s, Cp*), 2.12–2.34 (2 H, m, CH2), 2.72–2.90 (2 H, m,
CH2) and 7.15–7.82 (20 H, m, Ph). δP(CDCl3) 83.2 (s).
Preparations
[(Cp*Ir){(ꢁ4-C5Me5CHCl2)Ir}(ꢀ3-S)2RuCl(dppe)] 6. To a thf
(20 cm3) solution of CHCl2Li prepared from CH2Cl2 (19 mg,
0.22 mmol) and BunLi (0.22 mmol, in ether) at Ϫ78 ЊC was
added complex 3 (100 mg, 0.078 mmol) at this temperature. The
mixture was slowly warmed to room temperature with stirring.
The solvent was evaporated to dryness, and the residual dark
brown solid extracted with benzene. The benzene was removed
in vacuo, and the residue dissolved in thf. Addition of hexane to
the concentrated thf solution formed a small amount of dark
brown crystals of 6 and a brown powder, the latter of which was
filtered off. The brown filtrate was concentrated to give 6 (59
mg, 0.044 mmol, 57% yield) as dark brown microcrystals
(Found: C, 42.59; H, 4.27. C47H55Cl3Ir2P2RuS2 requires C,
42.19; H, 4.14%). δH(C6D6) 1.21 (3 H, s, Me), 1.75 (15 H, s,
Cp*), 1.79 (6 H, s, Me), 1.83–2.05 (2 H, m, CH2), 1.95 (6 H, s,
Me), 2.86–3.08 (2 H, m, CH2), 5.23 (1 H, s, CHCl2) and 7.00–
8.21 (20 H, m, Ph). δP(C6D6) 81.0 (s).
[(Cp*Ir)2(ꢀ3-S)2RuCl2(PPh3)]ؒ0.25thf 2ؒ0.25thf. To a suspen-
sion of complex 1 (1.01 g, 1.28 mmol) in thf (30 cm3) was added
[RuH2(PPh3)4] (1.75 g, 1.52 mmol), and the mixture stirred at
room temperature for 20 h. The resulting dark brown solution
was concentrated to 2 cm3, and the dark brown microcrystals
deposited were collected by filtration and washed with hexane
to give the trinuclear cluster 2ؒ0.25thf (1.36 g, 1.16 mmol, 91%
yield) (Found: C, 40.09; H, 4.05. C39H47Cl2Ir2O0.25PRuS2
requires C, 39.99; H, 4.04%). δH(CDCl3) 1.95 (30 H, s, Cp*),
7.28 (9 H, br, Ph) and 7.70 (6 H, br, Ph). δP(CDCl3) 82.9 (br s).
In a separate run the GLC analysis of the gaseous phase
indicated that H2 gas (1.44 mol per complex 1) was evolved
during the reaction.
[(Cp*Ir)2(ꢀ3-S)2RuCl(dppe)]Cl 3. To a suspension of complex
2ؒ0.25thf (2.00 g, 1.71 mmol) in thf (200 cm3) was added dppe
(1.05 g, 2.64 mmol), and the mixture stirred at room temper-
ature for 18 h. The resulting solution was concentrated to 10
cm3, and a dark brown powder deposited was collected by
filtration and washed with diethyl ether to give 3 (1.96 g, 1.52
mmol, 89% yield) (Found: C, 42.64; H, 4.30. C46H54Cl2Ir2-
P2RuS2 requires C, 42.85; H, 4.22%). δH(CDCl3) 1.88 (30 H, s,
Cp*), 2.25–2.40, 3.03–3.14 (2 H each, m, CH2) and 7.15–7.84
(20 H, m, Ph). δP(CDCl3) 81.0 (s).
[(Cp*Ir)2(ꢀ3-S)2(ꢀ-H)2Ru(dppe)] 7. To a solution of complex
3 (499 mg, 0.387 mmol) in CH2Cl2 (30 cm3)–ethanol (70 cm3)
was added NaBH4 (101 mg, 2.67 mmol) in small portions, and
the mixture stirred at room temperature for 45 h. The resulting
dark brown solution was evaporated to dryness, and the residue
extracted with benzene. The benzene was removed in vacuo and
the dark brown residue recrystallized from thf–hexane to give 7
(198 mg, 0.162 mmol, 42% yield) as a dark brown powder
(Found: C, 45.52; H, 4.79. C46H56Ir2P2RuS2 requires C, 45.27;
H, 4.62%). δH(C6D6) Ϫ14.73 [2 H, t, 2J(PH) 13.4, hydrido], 1.97
(30 H, s, Cp*), 2.78 [4 H, d, 2J(PH) 17.8 Hz, CH2] and 7.02–7.73
(20 H, m, Ph). δP(C6D6) 73.6 (s).
[(Cp*Ir)2(ꢀ3-S)2RuCl(depe)]Cl 4. This complex was prepared
from 2ؒ0.25thf and depe by a similar procedure to that
described for 3 and isolated in 81% yield as a dark brown
powder (Found: C, 32.78; H, 4.99. C30H54Cl2Ir2P2RuS2 requires
3
C, 32.84; H, 4.96%). δH(CDCl3) 1.06 [6 H, dt, J(PH) 14.5,
3J(HH) 7.6, CH2Me], 1.27 [6 H, dt, 3J(PH) 17.2, 3J(HH) 7.6 Hz,
CH2Me], 1.43–1.54 (2 H, m, CH2), 1.75–1.94 (6 H, m, CH2),
1.98–2.16 (4 H, m, CH2) and 2.11 (30 H, s, Cp*). δP(CDCl3)
82.3 (s).
[(Cp*Ir)2(ꢀ3-S)2(ꢀ-H)2Ru(depe)] 8. To a solution of complex 4
(200 mg, 0.182 mmol) in CH2Cl2 (10 cm3)–ethanol (5 cm3) was
added NaBH4 (69 mg, 1.8 mmol) in small portions, and the
mixture stirred at room temperature for 16 h. The resulting
dark brown solution was evaporated to dryness and the residue
extracted with hexane. Evaporation of the solvent to dryness
gave essentially pure 8 (100 mg, 0.097 mmol, 53% yield) as a
[(Cp*Ir)2(ꢀ3-S)2RuCl(depe)][BPh4] 4Ј. To a suspension of
complex 4 (50 mg, 0.046 mmol) in thf (10 cm3) was added
NaBPh4 (78 mg, 0.23 mmol), and the mixture stirred at room
2580
J. Chem. Soc., Dalton Trans., 1999, 2575–2582

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Table 6 X-Ray crystallographic data for complexes 4Ј, 5ؒCH2Cl2, 6, 7 and 12ؒ2C6H6
4Ј
5ؒCH2Cl2
6
7
12ؒ2C6H6
Formula
M
Crystal system
Space group
C54H74BClIr2P2RuS2
1381.02
Monoclinic
P21/a
C48H59Cl2F6Ir2P3RuS2
1463.44
Monoclinic
P21/n
C47H55Cl3Ir2P2RuS2
1337.89
Monoclinic
P21/c
C46H56Ir2P2RuS2
1220.53
Monoclinic
P21
C62H88Ir2RuS4
1447.13
Monoclinic
P21
a/Å
b/Å
c/Å
17.451(3)
17.774(4)
17.776(3)
97.66(1)
5464(1)
4
53.63
12549
(Rint = 0.046)
0.048, 0.032
11.460(3)
12.065(4)
37.612(3)
94.31(2)
5185(2)
4
57.52
9033
(Rint = 0.043)
0.041, 0.042
12.287(2)
15.247(2)
25.921(2)
94.10(1)
4843(1)
17.369(2)
14.609(1)
17.631(4)
90.26(1)
4473(1)
12.081(2)
16.767(3)
15.752(2)
91.66(1)
3189.4(8)
2
45.73
5825
(Rint = 0.025)
0.041, 0.027
β/Њ
U/Å3
Z
4
4
µ(Mo-Kα)/cmϪ1
Independent
reflections
61.54
8528
(Rint = 0.029)
0.038, 0.025
64.80
10679
(Rint = 0.043)
0.057, 0.039
Final R, RЈ [I > 3.0σ(I)]
dark brown powder (Found: C, 35.39; H, 5.47. C30H56Ir2P2RuS2
H, br s, Cp*), 2.71 [2 H, sep, 3J(HH) 6.9, p-CHMe2], 3.85 [4 H,
sep, 3J(HH) 6.9 Hz, o-CHMe2] and 6.75 (4 H, s, Ar).
2
requires C, 35.04; H, 5.49%). δH(C6D6) Ϫ14.56 [2 H, t, J(PH)
3
3
15.9, hydrido], 1.10 [12 H, dt, J(PH) 14.7, J(HH) 7.6 Hz,
CH2Me], 1.59–1.80 (12 H, m, CH2) and 2.07 (30 H, s, Cp*).
δP(C6D6) 79.6 (s).
[(Cp*Ir)2(ꢀ3-S)2Ru(SXy)2] 13.
A
mixture of complex
2ؒ0.25thf (104 mg, 0.089 mmol) and LiSXy (56 mg, 0.39 mmol)
in thf (8 cm3) was stirred at room temperature for 15 h. The
solvent was evaporated to dryness and the residue extracted
with thf. Addition of hexane to the concentrated thf solution
afforded 13 (10 mg, 0.009 mmol, 10% yield) as dark brown
plates (Found: C, 39.86; H, 4.61. C36H48Ir2RuS4 requires C,
39.50; H, 4.42%). δH(CDCl3) 1.97 (30 H, br s, Cp*), 2.17 (12 H,
br, o-Me) and 6.90 (6 H, br, Ar).
[(Cp*Ir)2(ꢀ3-S)2RuCl(CO)(PPh3)]Clؒ0.5CH2Cl2 9ؒ0.5CH2Cl2.
A CH2Cl2 (5 cm3) solution of complex 2ؒ0.25thf (49 mg, 0.042
mmol) was stirred under an atmosphere of CO at room tem-
perature for 2 h. Then the solution was concentrated under
reduced pressure, and hexane added to the resultant solution to
give 9ؒ0.5CH2Cl2 (42 mg, 0.034 mmol, 82% yield) as dark red
needles (Found: C, 38.50; H, 4.00. C39.5H46Cl3Ir2OPRuS2
requires C, 38.77; H, 3.79%). δH(CDCl3) 2.14 (30 H, s, Cp*) and
7.40–7.57 (15 H, m, Ph). δP(CDCl3) 40.5 (s). νmax/cmϪ1 (CO)
1929 (KBr).
Crystallography
Crystallographic data for complexes 4Ј, 5ؒCH2Cl2, 6, 7 and
12ؒ2C6H6 are summarized in Table 6. Diffraction data were
collected on a Rigaku AFC7R four-circle automated dif-
fractometer at 294 K with graphite-monochromatized Mo-Kα
radiation (λ = 0.71069 Å) using the ω–2θ scan technique for 4Ј,
7 and 12ؒ2C6H6 and the ω scan technique for 5ؒCH2Cl2 and 6.
The structure solution and refinements were carried out by
using the TEXSAN crystallographic software package.21 The
positions of the non-hydrogen atoms were determined by
Patterson methods (DIRDIF PATTY22) and subsequent
Fourier syntheses. All non-hydrogen atoms were refined by
full-matrix least-squares techniques (based on F) with aniso-
tropic thermal parameters except for the carbon atoms of the
CH2Cl2 molecule in 5ؒCH2Cl2, cluster 7 and the C6H6 molecules
in 12ؒ2C6H6. The carbon atoms of 7 were refined with isotropic
parameters, while fixed parameters were used for the carbon
atoms of the solvent molecules in 5ؒCH2Cl2 and 12ؒ2C6H6.
Hydrogen atoms except for those of the CH2Cl2 molecule in
5ؒCH2Cl2 and the hydrido ligands in 7 were placed at calculated
positions (dC–H = 0.95 Å) and included with fixed isotropic
parameters. For 7 and 12ؒ2C6H6, the Flack absolute structure
parameters23 were close to zero [Ϫ0.02(2) and Ϫ0.01(2)].
CCDC reference number 186/1523.
[(Cp*Ir)2(ꢀ3-S)2RuCl(CNXy)(PPh3)]Cl 10. A mixture of
complex 2ؒ0.25thf (93 mg, 0.079 mmol) and XyNC (11 mg,
0.083 mmol) in CH2Cl2 (5 cm3) was stirred at room temperature
for 20 h. The reaction mixture was filtered and concentrated
under reduced pressure. Addition of hexane to the concen-
trated solution afforded 10 (82 mg, 0.064 mmol, 80% yield) as a
dark brown solid (Found: C, 43.58; H, 4.24; N, 0.84. C47H54Cl2-
Ir2NPRuS2 requires C, 43.95; H, 4.24; N, 1.09%). δH(CDCl3)
2.05 (6 H, s, o-Me), 2.11 (30 H, s, Cp*), 7.00 (3 H, br, Ar) and
7.34–7.53 (15 H, m, PPh3). δP(CDCl3) 43.0 (s). νmax/cmϪ1 (CN)
2054 (KBr).
[(Cp*Ir)2(ꢀ3-S)2Ru(CNXy)2(PPh3)][BPh4]2ؒCH2Cl2 11ؒCH2-
Cl2. A mixture of complex 2ؒ0.25thf (100 mg, 0.085 mmol),
XyNC (28 mg, 0.21 mmol) and NaBPh4 (292 mg, 0.853 mmol)
in CH2Cl2 (5 cm3) was stirred at room temperature for 15 h. The
reaction mixture was filtered and concentrated, and addition of
ether afforded 11ؒCH2Cl2 (111 mg, 0.054 mmol, 63% yield) as a
reddish brown powder (Found: C, 61.03; H, 5.10; N, 1.57.
C105H105B2Cl2Ir2N2PRuS2 requires C, 60.98; H, 5.12; N, 1.35%).
δH(CD2Cl2) 1.91 (30 H, s, Cp*), 2.04 (12 H, s, o-Me) and 6.80–
7.51 (61 H, m, Ar). δP(CD2Cl2) 45.0 (s). νmax/cmϪ1 (CN) 2106
and 2135 (KBr).
See http://www.rsc.org/suppdata/dt/1999/2575/ for crystallo-
graphic files in .cif format.
[(Cp*Ir)2(ꢀ3-S)2Ru(STip)2] 12.
A
mixture of complex
Acknowledgements
2ؒ0.25thf (102 mg, 0.087 mmol) and LiSTip (83 mg, 0.34 mmol)
in thf (8 cm3) was stirred at room temperature for 15 h. Then
the solvent was evaporated to dryness, and the residue extracted
with benzene. Addition of MeOH to the concentrated benzene
solution afforded crystals of 12ؒ2C6H6 which were used for
crystallographic study. The crystals gave off benzene on drying
under vacuum to give 12 (78 mg, 0.060 mmol, yield 69%) as a
dark brown solid (Found: C, 46.43; H, 6.01. C50H76Ir2RuS4
requires C, 46.52; H, 5.93%). δH(CDCl3) 1.13 [24 H, d, 3J(HH)
This work was supported by a Grant-in-aid for Specially Pro-
moted Research (09102004) from the Ministry of Education,
Science, Sports and Culture, Japan.
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