Preparation and reactivity of a ruthenium complex bearing a 2,6-bis(trimethylsilyl)benzenethiolate ligand

Article abstract of DOI:10.1021/om100689f

The reaction of [Cp Ru(μ₃-Cl)]₄ with ArSK (ArS = 2,6-(Me₃Si)₂C₆H₃S) gives the mononuclear ruthenium complex with π-arenethiolate ligand [Cp Ru(ν⁵-SAr)] via [Cp Ru(μ-SAr)]₂. Further reactions of [Cp Ru(ν⁵-SAr)] with HCl and [Cp Ru(μ₃-Cl)] ₄ give the corresponding monoruthenium complex [Cp Ru(ν⁶-HSAr)]Cl and diruthenium complex [Cp Ru(μ- ν⁵:ν¹-SAr)RuClCp] in high yields, respectively.

Full text of DOI:10.1021/om100689f

4148 Organometallics 2010, 29, 4148–4153
DOI: 10.1021/om100689f
Preparation and Reactivity of a Ruthenium Complex Bearing
a 2,6-Bis(trimethylsilyl)benzenethiolate Ligand
Masahiro Yuki, Yoshihiro Miyake, and Yoshiaki Nishibayashi*
Institute of Engineering Innovation, School of Engineering, The University of Tokyo,
Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan
Received July 13, 2010
The reaction of [Cp*Ru(μ3-Cl)]4 with ArSK (ArS = 2,6-(Me3Si)2C6H3S) gives the mononuclear
ruthenium complex with π-arenethiolate ligand [Cp*Ru(η5-SAr)] via [Cp*Ru(μ-SAr)]2. Further reac-
tions of [Cp*Ru(η5-SAr)] with HCl and [Cp*Ru(μ3-Cl)]4 give the corresponding monoruthenium
complex [Cp*Ru(η6-HSAr)]Cl and diruthenium complex [Cp*Ru(μ-η5:η1-SAr)RuClCp*] in high yields,
respectively.
Introduction
good to high yields with complete selectivity,1,2 we have found
novel transformations of propargylic alcohols catalyzed only
by thiolate-bridged diruthenium complexes [Cp*RuCl(μ2-SR)]2
(R = Me, Et, nPr, iPr).3,4 More recently, we have developed en-
antioselective versions of these catalytic reactions by using chiral
thiolate-bridged diruthenium complexes [Cp*RuCl(μ2-SR*)]2
(SR* = (R)-SCH(Et)C6H2Ph3 and (R)-SCH(Et)C6H3Ph2)
as catalysts.5
Since the first report on the ruthenium-catalyzed propargylic
substitution reactions of propargylic alcohols with nucleophiles
to give the corresponding propargylic-substituted products in
*To whom correspondence should be addressed. E-mail: ynishiba@
sogo.t.u-tokyo.ac.jp.
(1) (a) Nishibayashi, Y.; Wakiji, I.; Hidai, M. J. Am. Chem. Soc. 2000,
122, 11019. (b) Nishibayashi, Y.; Wakiji, I.; Ishii, Y.; Uemura, S.; Hidai, M.
J. Am. Chem. Soc. 2001, 123, 3393. (c) Nishibayashi, Y.; Inada, Y.; Hidai,
M.; Uemura, S. J. Am. Chem. Soc. 2002, 124, 7900. (d) Nishibayashi, Y.;
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(2) The result of the density functional theory calculation on the
model reaction also supports the proposed reaction pathway of the
ruthenium-catalyzed propargylic substitution reactions of propargylic
alcohols with nucleophiles, where ruthenium-allenylidene complexes
work as key intermediates; see: (a) Ammal, C. S.; Yoshikai, N.; Inada,
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lographic analysis was not known at this stage: Dev, S.; Imagawa, K.;
Mizobe, Y.; Cheng, G.; Wakatsuki, Y.; Yamazaki, H.; Hidai, M.
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83, 358, and references therein.
As an extension of our study, we have envisaged the pre-
paration of a novel thiolate-bridged diruthenium complex
bearing bulky 2,6-bis(trimethylsilyl)benzenethiolate6 as a
bridging ligand because the introduction of sterically demand-
ing ligands is known to provide unique reactive sites on the
transition-metal complexes.7 The reaction of [Cp*RuCl-
(μ2-Cl)]2 with ArSH (ArS = 2,6-(Me3Si)2C6H3S) in tetrahydro-
furan (THF) at room temperature for 12 h did not give the
target dinuclear diruthenium complex [Cp*RuCl(μ2-SAr)]2, but
only a small amount of the corresponding mononuclear ruthe-
nium complex with π-arenethiolate ligand [Cp*Ru(η5-SAr)] (1)
(Scheme 1). The unusual coordination mode of the benzenethiolate
(5) (a) Nishibayashi, Y.; Onodera, G.; Inada, Y.; Hidai, M.; Uemura,
S. Organometallics 2003, 22, 873. (b) Inada, Y.; Nishibayashi, Y.; Uemura,
S. Angew. Chem., Int. Ed. 2005, 44, 7715. (c) Matsuzawa, H.; Miyake, Y.;
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Kanao, K.; Miyake, Y.; Nishibayashi, Y. Org. Lett. 2007, 9, 5561. (e) Kanao,
K.; Matsuzawa, H.; Miyake, Y.; Nishibayashi, Y. Synthesis 2008, 3869.
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(g) Fukamizu, K.; Miyake, Y.; Nishibayashi, Y. J. Am. Chem. Soc. 2008,
130, 10498. (h) Kanao, K.; Miyake, Y.; Nishibayashi, Y. Organometallics
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Ikagawa, Y.; Suizu, R.; Tatsumi, K. J. Organomet. Chem. 2007, 692, 4792.
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(8) Gimeno, J.; Crochet, P. In Comprehensive Organometallic Chemistry
III; Bruce, M., Ed.; Elsevier: Amsterdam, 2007; Vol. 6, Chapter 14, pp 465-550.
(4) (a) Nishibayashi, Y.; Imajima, H.; Onodera, G.; Hidai, M.;
Uemura, S. Organometallics 2004, 23, 26. (b) Nishibayashi, Y.; Imajima,
H.; Onodera, G.; Inada, Y.; Hidai, M.; Uemura, S. Organometallics 2004, 23,
5100. (c) Miyake, Y.; Endo, S.; Nomaguchi, Y.; Yuki, M.; Nishibayashi, Y.
Organometallics 2008, 27, 4017. (d) Miyake, Y.; Endo, S.; Yuki, M.; Tanabe,
Y.; Nishibayashi, Y. Organometallics 2008, 27, 6039. (e) Tanabe, Y.; Kanao,
K.; Miyake, Y.; Nishibayashi, Y. Organometallics 2009, 28, 1138. (f ) Kanao,
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r
pubs.acs.org/Organometallics
Published on Web 08/23/2010
2010 American Chemical Society

Article
Scheme 1. Reaction of [Cp*RuCl(μ2-Cl)]2 with ArSK
Organometallics, Vol. 29, No. 18, 2010 4149
The diruthenium complex 2 was unstable and gradually
converted into π-arenethiolate complex [Cp*Ru(η5-SAr)] (1).
In fact, 1 was obtained in 80% isolated yield after a THF
solution of 2was stood at room temperature for 20 days. The 1H
NMR spectrum of 1 displays one set of trimethylsilyl and Cp*
signals at 1.84 and 0.36 ppm in 18:15 ratio, respectively, showing
1:1 complexation of the Cp*Ru fragment with the SAr moiety.
1
On the other hand, the H NMR spectrum of 1 exhibits two
to the ruthenium atom in 1 prompted us to investigate the
reactivity of 1 in detail.
high-field-shifted signals at 4.85 and 4.34 ppm ascribable to
the aryl protons of the thiolate ligand. In the 13C NMR spec-
trum of 1, signals of aromatic carbons bound to the ruthenium
center were observed at high field (97.5-82.3 ppm), whereas the
signal of the carbon atom attached to the sulfur atom appeared
at 152.0 ppm, suggesting η5-coordination. A similar transfor-
mation was previously reported only in the reaction of the
diruthenium complex bearing O-bonded 2,4-bis(tert-butyl)phe-
nolate ligand [Cp*Ru(μ2-OC6H4-2,4-tBu2)]2 to give the corre-
sponding mononuclear ruthenium complex with π-benzolate
ligand [Cp*Ru(η5-OC6H4-2,4-tBu2)].9i
The molecular structure of 1 was unequivocally deter-
mined by X-ray crystallography. The unit cell contains two
independent molecules, but the structural parameters were
almost the same. An ORTEP drawing and selected bond
distances of 1 are shown in Figure 1. Evidently the 2,6-
bis(trimethylsilyl)benzenethiolate ligand is bound to the
ruthenium atom through the aromatic carbons. The sulfur
It is well known that [Cp*Ru(μ3-Cl)]4 (Cp* = η5-C5Me5)
reacted with various arene derivatives including phenol to give
the corresponding π-arene complexes [Cp*Ru(η6-arene)]Cl
(Scheme 2).8-11 In sharp contrast, reactions of [Cp*Ru(μ3-Cl)]4
with benzenethiols did not give the corresponding π-arene
complexes, but the corresponding benzenethiolate-bridged diru-
thenium complexes [Cp*Ru(μ2-SAr0)]2 (Ar0=Ph, 2,6-Me2C6H3,
C6F5) because of high affinity between the ruthenium atom and
thiolate sulfur.12 Although the reaction with sterically demanding
2,6-dimesitylbenzenethiolate (DmpS) gave the corresponding
mononuclear ruthenium complex [Cp*Ru(η1-SDmp)],13 no for-
mation of the corresponding π-arene complexes was observed at
all. As a new approach to the preparation of π-benzene com-
plexes, we have now found that the reaction of [Cp*Ru(μ3-Cl)]4
with ArSK gave 1 in good yield with complete selectivity. Herein,
we describe the preparation and reactivity of 1 in detail.
˚
atom is far away from the ruthenium center (Ru S: 3.8 A).
3 3 3
Results and Discussion
The carbon atom attached to the sulfur atom has no or very
weak interaction with the ruthenium center because the
interatomic distance between ruthenium and the carbon
Treatment of [Cp*Ru(μ3-Cl)]4 with ArSK in THF at room
temperature for 4 h gave the dinuclear ruthenium complex
[Cp*Ru(μ-SAr)]2 (2) in 72% isolated yield (Scheme 3). The
1H NMR spectrum of 2 exhibits proton signals assignable to
trimethylsilyl and Cp* moieties in 18:15 ratio, showing 1:1
complexation of the Cp*Ru fragment with the SAr moiety.
The ring protons of the aryl moieties were observed in the
normal region for aromatic protons (7.71-7.04 ppm), in-
dicating that the thiolate ligand is bound to the ruthenium
center through the sulfur atom in a general manner. 13C
NMR spectrum of 2 was also consistent with the structure. In
addition, the mass spectral data for 2 support the dinuclear
structure of 2 (see Experimental Section). Unfortunately, we
have not yet characterized the molecular structure of 2 by
X-ray crystallography.
˚
atoms (2.37 A (mean)) is longer than those between ruthe-
˚
nium and other carbon atoms (2.19-2.26 A). These devia-
tions of bond distances between ruthenium and carbon
atoms indicate that the 2,6-bis(trimethylsilyl)phenyl moiety
is coordinated to the ruthenium atom in a η5-pentadienyl
fashion rather than a η6-arene fashion. The η5-pentadienyl
structure was analogous to the corresponding phenolate
complexes.9 The bond length between sulfur and the carbon
˚
atoms (1.72 A (mean)) is shorter than those of general
14
arenethiolato ligands (ca. 1.80 A), indicating a partial
˚
double-bond character between the sulfur and carbon atoms.
The π-coordination of the 2,6-bis(trimethylsilyl)benzene-
thiolate ligand in 1 fulfills the 18-electron count for the ruthe-
nium center. Only one example of the coordination mode of the
η5-pentadienyl structure bearing a thiolate ligand was pre-
viously reported for the molybdenum complex bearing two
2,6-bis(trimethylsilyl)phenyl thiolate ligands.15
(9) (a) Chaudret, B.; He, X.; Huang, Y. J. Chem. Soc., Chem.
Commun. 1989, 1844. (b) Loren, S. D.; Campion, B. K.; Heyn, R. H.; Tilley,
D. T.; Bursten, B. E.; Luth, K. W. J. Am. Chem. Soc. 1989, 111, 4712. (c) He,
X. D.; Chaudret, B.; Dahan, F.; Huang, Y.-S. Organometallics 1991, 10, 970.
(d) Koelle, U.; Wang, M. H.; Raabe, G. Organometallics 1991, 10, 2573. (e)
Vichard, D.; Gruselle, M.; Amouri, H. E.; Jaouen, G. J. Chem. Soc., Chem.
Commun. 1991, 46. (f ) Huang, Y.-S.; Sabo-Etienne, S.; He, X.-D.; Chaudret,
On the other hand, the diruthenium complex 2 rapidly
reacted with 2 equiv of isonitriles at room temperature for
20 min to give [Cp*Ru(η1-SAr)(CNR)2] (3a, R = tBu; 3b,
R = p-MeOC6H4) in 66% and 75% yields (Scheme 3). IR
€
B. Organometallics 1992, 11, 3031. (g) Koelle, U.; Hornig, A.; Englert, U.
spectra of 3 showed two νCN bands (3a: 2111 and 2045 cm-1
,
€
€
Organometallics 1994, 13, 4064. (h) Hornig, A.; Englert, U.; Kolle, U.
J. Organomet. Chem. 1994, 464, C25. (i) B€ucken, K.; Koelle, U.; Pasch, R.;
Ganter, B. Organometallics 1996, 15, 3095. ( j) Pasch, R.; Koelle, U.; Ganter,
B.; Englert, U. Organometallics 1997, 16, 3950. (k) Morvan, D.; Rauchfuss,
T. B.; Wilson, S. R. Organometallics 2009, 28, 3161. (l) Trujillo, A.;
Fuentealba, M.; Carrillo, D.; Manzur, C.; Ledoux-Rak, I.; Hamon, J.-R.;
Saillard, J.-Y. Inorg. Chem. 2010, 49, 2750.
3b: 2102 and 2030 cm-1). The molecular structure of 3a was
unequivocally determined by X-ray crystallography. An OR-
TEP drawing and selected bond distances of 3a are shown in
Figure 2. The 2,6-bis(trimethylsilyl)benzenthiolate ligand was
(10) Fish, R. H.; Fong, R. H.; Tran, A.; Baralt, E. Organometallics
1991, 10, 1209.
(11) Chaudret, B.; Jalon, F.; Perez-Manrique, M.; Lahoz, F. J.; Plou,
F. J.; Sanchez-Delgado, R. New J. Chem. 1990, 14, 331.
(12) (a) Koelle, U.; Rietmann, C.; Englert, U. J. Organomet. Chem.
(14) (a) Ruhlandt-Senge, K.; Davis, K.; Dalal, S.; Englich, U.; Senge,
M. O. Inorg. Chem. 1995, 34, 2587. (b) Chadwick, S.; Englich, U.;
Ruhlandt-Senge, K.; Watson, C.; Bruce, A. E.; Bruce, M. R. M. J. Chem.
€
€
€
1992, 423, C20. (b) Hornig, A.; Rietmann, C.; Englert, U.; Wagner, T.; Kolle,
U. Chem. Ber. 1993, 126, 2609. (c) Takahashi, A.; Mizobe, Y.; Matsuzaka,
H.; Dev, S.; Hidai, M. J. Organomet. Chem. 1993, 456, 243.
(13) Ohki, Y.; Sadohara, H.; Takikawa, Y.; Tatsumi, K. Angew.
Chem., Int. Ed. 2004, 43, 2290.
Soc., Dalton Trans. 2000, 2167. (c) Hildebrand, A.; Lonnecke, P.; Silaghi-
Dumitrescu, L.; Silaghi-Dumitrescu, I.; Hey-Hwakins, E. Dalton Trans.
2006, 967.
(15) Komuro, T.; Matsuo, T.; Kawaguchi, H.; Tatsumi, K. J. Am.
Chem. Soc. 2003, 125, 2070.

4150 Organometallics, Vol. 29, No. 18, 2010
Scheme 2. Reactions of [Cp*Ru(μ3-Cl)]4 with Arenes
Yuki et al.
Scheme 3. Reactions of [Cp*Ru(μ-SAr)]2 (2)
bound to the ruthenium center through the sulfur atom. The
ruthenium center adopts a three-legged piano stool geometry
with one thiolate, two isonitriles, and one Cp* ligand. Two silyl
groups of the 2,6-bis(trimethylsilyl)benzenthiolate moiety are
highly bent away from the ruthenium center. The silicon atoms
(Scheme 4). In the 1H NMR spectrum of 4, the thiol proton
was observed at 3.42 ppm. In the 13C NMR spectrum of 4,
all aromatic carbons of the 2,6-bis(trimethylsilyl)phenyl
moiety including the carbon atom attached to the sulfur
atom (102.7 ppm) are observed at high field (102.7-88.9 ppm)
as typical for η6-arene complexes. A similar change from η5- to
η6-coordination is known for the protonation of the corre-
sponding phenolate analogues.9
The molecular structure of 4 was unequivocally deter-
mined by X-ray crystallography. An ORTEP drawing and
selected bond distances of 4 are shown in Figure 3. The
sandwich structure of 1 is preserved in 4. However, the bond
distances between sulfur and carbon bonds are elongated
˚
were displaced ca. 0.5 A out of the least-squares plane defined by
the six aromatic carbons, representing the severe steric repul-
sion between the trimethylsilyl group and the other ligands.
A similar mononuclear ruthenium complex, [Cp*Ru(SDmp)-
(CNtBu)2], was previously obtained from the reaction of mono-
nuclear ruthenium complex [Cp*Ru(SDmp)] with isonitriles.13
In addition, the thiolate-bridged diruthenium complex [Cp*-
Ru(StBu)]2 reacted with isonitriles to give the corresponding
dinuclear complex [Cp*Ru(StBu)(CNtBu)]2.12a
˚
˚
to 1.79 A (mean) by 0.07 A compared to those of 1. Bond
distances between ruthenium and carbon atoms attached to
Treatment of 1 with HCl in dichloromethane at room
temperature for 1 h gave the corresponding mononuclear
ruthenium complex [Cp*Ru(η6-HSAr)]Cl (4) in 94% yield
˚
˚
sulfur atoms are 2.23-2.28 A, which are ca. 0.1 A shorter
than those of 1 and are comparable to the distances between

Article
Organometallics, Vol. 29, No. 18, 2010 4151
Figure 3. ORTEP view of 4. Only one of two crystallographically
independent molecules is shown. Selected interatomic distances
(A) for molecule A: Ru-C1 2.284(2), Ru-C2 2.269(3), Ru-C3
2.209(2), Ru-C4 2.192(2), Ru-C5 2.193(2), Ru-C6 2.257(3),
S-C1 1.789(2). For molecule B: Ru-C1 2.231(2), Ru-C2
2.254(2), Ru-C3 2.211(2), Ru-C4 2.195(2), Ru-C5 2.211(2),
Ru-C6 2.256(2), S-C1 1.787(2).
Figure 1. ORTEP view of 1. Only one of two crystallographically
independent molecules is shown. Selected interatomic distances
(A) for molecule A: Ru-C1 2.368(4), Ru-C2 2.263(4), Ru-C3
2.196(4), Ru-C4 2.185(4), Ru-C5 2.190(4), Ru-C6 2.257(4),
S-C1 1.721(4). For molecule B: Ru-C1 2.378(4), Ru-C2 2.255(4),
Ru-C3 2.190(4), Ru-C4 2.191(4), Ru-C5 2.192(4), Ru-C6
2.262(3), S-C1 1.727(4).
˚
˚
Figure 2. ORTEP view of 3a. Only one of two crystallographi-
cally independent molecules is shown. Selected interatomic dis-
tances (A) for molecule A: Ru-S 2.4354(12), Ru-C23 1.923(6),
Ru-C28 1.925(5), S-C1 1.786(5). For molecule B: Ru-S
2.4398(13), Ru-C23 1.922(5), Ru-C28 1.896(7), S-C1 1.781(5).
Figure 4. ORTEP view of 5. Only one of two crystallographically
˚
independent molecules is shown. Selected interatomic distances (A)
˚
for molecule A: Ru1-C1 2.319(5), Ru1-C2 2.275(5), Ru1-C3
2.205(6), Ru1-C4 2.204(6), Ru1-C5 2.194(6), Ru1-C6 2.271(6),
S-C1 1.768(5), Ru2-S 2.3400(16). For molecule B: Ru1-C1
2.338(6), Ru1-C2 2.267(6), Ru1-C3 2.199(7), Ru1-C4 2.190(7),
Ru1-C5 2.200(7), Ru1-C6 2.272(6), S-C1 1.758(6), Ru2-S
2.3440(16).
Scheme 4. Reactions of [Cp*Ru(η5-SAr)] (1)
On the other hand, the reaction of 1 with [Cp*Ru(μ3-Cl)]4
in THF at room temperature for 12 h gave the corresponding
diruthenium complex [Cp*Ru(μ-η5:η1-SAr)RuClCp*] (5) in
93% isolated yield (Scheme 4). In the 13C NMR spectrum of
5, the signal corresponding to the carbon atom attached to
the sulfur atom appeared at 138.0 ppm, which was inter-
mediate in value between 1 (152.0 ppm) and 4 (102.7 ppm).
These observations indicate that coordination of the sulfur
atom to a Cp*RuCl fragment in 5 results in the interme-
diate structure of the 2,6-bis(trimethylsilyl)benzenethiolate
moiety between η5-pentadienyl and η6-arene character.
The molecular structure of 5 was unequivocally deter-
mined by X-ray crystallography. The unit cell contains two
independent molecules. An ORTEP drawing and selected
bond distances of 5 are shown in Figure 4. In the dinuclear
complex, the [Cp*Ru(η5-SAr)] moiety served as a sulfur
donor ligand to the Cp*RuCl fragment. The bond distances
˚
ruthenium and other carbon atoms (2.19-2.27 A) in 4. These
structural data indicate that the 2,6-bis(trimethylsilyl)phenyl
˚
between ruthenium and sulfur atoms (2.34 A (mean)) were
unusual. The bond distances between the carbon and sulfur
moiety in 4 adopts a normal η6-arene coordination mode.

4152 Organometallics, Vol. 29, No. 18, 2010
Table 1. Summary of Crystallographic Data
Yuki et al.
1 0.25C6H14
3
3a 0.5C6H14
3
4
5
formula
fw
C23.5H39.5RuSi2S
511.36
C35H61N2RuSSi2
699.18
C22H37ClRuSi2S
526.29
C32H51Ru2Si2S
761.56
cryst size/mm
color, habit
cryst syst
space group
0.54 ꢀ 0.23 ꢀ 0.02
yellow plate
triclinic
0.50 ꢀ 0.25 ꢀ 0.05
orange plate
monoclinic
P21/c (No. 14)
20.2705(8)
18.1441(7)
22.610(1)
90
104.327(1)
90
8057.2(6)
8
1.153
0.60 ꢀ 0.30 ꢀ 0.05
colorless plate
triclinic
0.30 ꢀ 0.20 ꢀ 0.15
wine red prism
monoclinic
P21/n (No. 14)
14.9562(5)
26.9734(8)
18.6671(7)
90
109.586(1)
90
7094.9(4)
8
1.426
P1 (No. 2)
11.1331(4)
15.9138(5)
16.1451(5)
92.964(1)
108.106(1)
107.073(1)
2566.6(2)
4
1.323
0.793
25 328 (2θ < 55°)
11 693 (0.041)
518
P1 (No. 2)
11.6073(8)
14.0285(9)
16.641(1)
67.495(2)
89.219(2)
89.219(2)
2500.1(3)
4
1.398
0.919
24 112 (2θ < 55°)
11 235 (0.031)
517
˚
a/A
˚
b/A
˚
c/A
R/deg
β/deg
γ/deg
3
˚
V/A
Z
dc/g cm-3
μ(Mo KR)/mm-1
no. of data collected
no. of unique data (Rint
no. of params refined
R1a (F2 > 2σ)
wR2b (all data)
goodness of
0.523
1.072
58 072 (2θ < 50°)
14 459 (0.097)
742
0.065
0.199
1.02
68 342 (2θ < 55°)
16 158 (0.085)
707
0.060
0.192
1.08
)
0.039
0.108
1.09
0.031
0.081
1.08
fit indicatorc
residual electron
þ0.91 to -1.40
þ1.88 to -1.07
þ0.60 to -0.50
þ1.21 to -1.45
-3
˚
density/e A
P
P
P
P
P
aR1 =
Fo| - |Fc
/
|Fo|. bwR2 = [ w(Fo2 - Fc2)2/ w(Fo)2]1/2. c[ w(Fo2 - Fc2)2/(Nobs - Nparam)]1/2
.
˚
atoms (1.76 A (mean)) were elongated by coordination to the
Cp*RuCl fragment, but were shorter than that of 4. At the
same time, the interatomic distances between ruthenium and
in vacuo to remove HN(SiMe3)2. The white solid of ArSK was
redissolved in THF (5 mL) and was transferred to an orange-
brown THF (5 mL) solution of [Cp*RuCl]4 (136 mg, 0.125
mmol). The resulting purple solution was stirred at room
temperature for 4 h. The solution was concentrated to dryness,
and the residue was extracted with hexane. Concentration of the
hexane extract gave a purple powder of 2 (227 mg, 0.232 mmol).
Recrystallization from cold hexane (-30 °C) afforded analyti-
cally pure 2 as purple microcrystals (176 mg, 0.180 mmol, 72%).
Data for 2: 1H NMR (THF-d8) δ 7.71 (d, JHH = 7 Hz, 4H), 7.04
(t, JHH = 7 Hz, 2H), 1.45 (s, 30H, Cp*), 0.09 (s with 29Si
satellites, 3JHSi = 6 Hz and 36H, SiMe3); 13C NMR (THF-d8)
δ 142.7 (3,5-positons of Ar), 127.5 (2,6-positions of Ar), 120.3
(4-position of Ar), 77.8 (C5Me5), 11.2 (C5Me5), 0.4 (SiMe3);
FAB MS (Xe, m-nitrobenzyl alcohol matrix) m/z 980 (18, Mþ),
907 (29, Mþ - SiMe3), 489 (100, Cp*RuSAr-H). Anal.
Calcd for C22H36RuSSi2: C, 53.94; H, 7.41. Found: C, 54.06;
H, 7.13.
˚
the carbon atom attached to the sulfur atom (2.33 A (mean))
are shorter than those of 1, but still longer than those of 4.
Theses results indicate that the extent of donor-acceptor
interaction of 1 at the sulfur atom influences the coordina-
tion structure of the 2,6-bis(trimethylsilyl)benzenethiolate
moiety.
In summary, we have newly prepared and characterized a
mononuclear ruthenium complex with π-arenethiolate ligand
[Cp*Ru(η5-SAr)] (1) from the reaction of [Cp*Ru(μ3-Cl)]4
with ArSK (ArS = 2,6-(Me3Si)2C6H3S). Further reactions of
the monoruthenium complex 1 withHCl and [Cp*Ru(μ3-Cl)]4
gave the corresponding monoruthenium complex [Cp*Ru-
(η6-HSAr)]Cl (4) and diruthenium complex [Cp*Ru(μ-η5:
η1-SAr)RuClCp*] (5) in high yields, respectively.
Preparation of [Cp*Ru(η5-SAr)] (1). Complex 2 (41.7 mg,
0.0426 mmol) was dissolved in THF (5 mL). After 20 days at
room temperature, the solution was concentrated to dryness.
The dark yellow residue was washed with hexane to give a yellow
Experimental Section
General Methods. All manipulations were carried out under
an inert atmosphere using standard Schlenk-line techniques or
in a glovebox. Solvents were dried over appropriate agents
crystalline solid of 1 0.25C6H14 (34.9 mg, 0.0682 mmol, 80%).
Data for 1: 1H NMR (THF-d8) δ 5.24-5.14 (m, 3H, Ar), 1.84 (s,
3
15H, Cp*), 0.36 (s with 29Si satellites, JHSi = 7 Hz and 18H,
3
16
SiMe3); 13C NMR (THF-d8) δ 152.0 (1-position of Ar), 97.5
(2,6-position of Ar), 91.9 (C5Me5), 89.7 (3,5-position of Ar),
82.3 (4-position of Ar), 10.9 (C5Me5), 1.2 (SiMe3). Anal. Calcd
under an inert atmosphere. Compounds [Cp*RuCl]4 and
2,6-bis(trimethylsilyl)benzenethiol6 were prepared by the litera-
ture methods. Other reagents were purchased from commercial
sources and were used as received. NMR spectra were recorded
on JEOL JNM-EX270 spectrometers, and chemical shifts are
quoted in ppm. Assignments of 13C NMR signals were made by
using DEPT and inverse-gated decoupling methods. Infrared
spectra were recorded on a JASCO FT/IR-4100 spectrometer.
Elemental analyses were performed on an Exeter Analytical
CE-440 elemental analyzer.
for C23.5H39.5RuSSi2 (1 0.25C6H14): C, 55.19; H, 7.79. Found:
3
C, 54.84; H, 7.66.
t
Preparation of [Cp*Ru(η1-SAr)(CNR)2] (3a; R = Bu). To a
THF (5 mL) solution of 2 (48.9 mg, 0.0499 mmol) was added
tBuNC (27.2 mg, 0.327 mmol). The mixture was stirred at room
temperature for 5 min. After filtration, the dark orange solution
was concentrated to dryness. The residue was recrystallized
from cold hexane (-30 °C). The orange platelet crystals were
dried in vacuo to afford 3a (42.9 mg, 0.0654 mmol, 66%). Data
for 3a: 1H NMR (C6D6) δ 7.47 (d, J = 7 Hz, 2H, Ar), 7.05 (t, J =
7 Hz, 1H, Ar), 1.72 (s, 15H, Cp*), 1.05 (s, 18H, tBu), 0.75 (s, 18H,
SiMe3); 13C NMR (C6D6) δ 167.4 (1-position of Ar), 146.2 (2,6-
positions of Ar), 134.5 (3,5-positions of Ar), 122.0 (4-position of
Ar), 92.8 (C5Me5), 55.4 (CMe3), 31.4 (CMe3), 9.9 (C5Me5), 2.4
Preparation of [Cp*Ru(μ-SAr)]2 (2). To a THF (2 mL) solu-
tion of 2,6-bis(trimethylsilyl)benzenethiol (128 mg, 0.501 mmol)
was added a THF (3 mL) solution of KN(SiMe3)2 (100 mg, 0.501
mmol). After 30 min, the resulting yellow solution was dried
(16) Fagan, P. J.; Ward, M. D.; Calabrese, J. C. J. Am. Chem. Soc.
1989, 111, 1698.

Article
Organometallics, Vol. 29, No. 18, 2010 4153
(SiMe3); IR (KBr) νCN 2111 and 2045 cm-1. Anal. Calcd for
C32H54N2RuSSi2: C, 58.58; H, 8.30, N, 4.27. Found: C, 58.90;
H, 8.36; N, 4.24.
(t, 3JHH = 6 Hz, 1H, Ar), 5.27 (d, 3JHH = 6 Hz, 2H, Ar), 1.90 (s,
15H, Cp*), 1.59 (s, 15H, Cp*), 0.42 (s, 18H, SiMe3); 13C{1H}
NMR (THF-d8) δ 138.0 (1-position of Ar), 100.3 (2,6-positions
of Ar), 93.3 (C5Me5), 90.8 (3,5-positions of Ar), 86.3 (4-position
of Ar), 70.6 (C5Me5), 11.3 (C5Me5), 11.2 (C5Me5), 2.9 (SiMe3).
Preparation of [Cp*Ru(η1-SAr)(CNR)2] (3b; R = p-MeOC6-
H4). To a THF solution (3 mL) of 2 (48.8 mg, 0.0498 mmol) was
added p-methoxyphenylisonitrile (56.0 mg, 0.421 mmol) in THF
(2 mL). The mixture was stirred at room temperature for 20 min.
After filtration, the dark orange solution was concentrated to
dryness. The oily residue was recrystallized from cold hexane
(-30 °C), affording orange prisms of 3b (56.2 mg, 0.0743 mmol,
75%). Data for 3b: 1H NMR (C6D6) δ 7.47 (d, J = 7.2 Hz, 2H,
Ar), 7.22 (t, J = 7.2 Hz, 1H, Ar), 6.98 (d, J = 8.9 Hz, 4H, C6H4-
OMe), 6.53 (d, J = 8.9 Hz, 4H, C6H4OMe), 3.11 (s, 6H, OMe),
1.85 (s, 15H, Cp*), 0.68 (s, 18H, SiMe3); 13C NMR (C6D6) δ
171.2 (CNR), 166.6 (1-position of Ar), 158.3 (4-position of R),
146.1 (2,6-positions of Ar), 135.3 (3,5-positions of Ar), 126.9
(2,6-positions of R), 124.5 (1-position of R), 122.5 (4-position of
Ar), 114.5 (3,5-positions of R), 95.1 (C5Me5), 54.9 (OMe), 10.1
(C5Me5), 2.1 (SiMe3); IR (KBr) νCN 2102 and 2030 cm-1. Anal.
Calcd for C38H50N2O2RuSSi2: C, 60.36; H, 6.67, N, 3.70. Found:
C, 59.98; H, 6.52; N, 3.57.
Anal. Calcd for C35H58ClRu2SSi2 (5 0.5C6H14): C, 52.24; H,
3
7.27. Found: C, 52.34; H, 7.18.
X-ray Crystallography. Crystallographic data are summa-
rized in Table 1. Paraffin-coated crystals were placed on a nylon
loop and mounted on a Rigaku RAXIS RAPID imagining plate
system. Data were collected at -100 °C under a cold nitrogen
stream using graphite-monochromated Mo KR radiation (λ =
˚
0.71069 A). Data were corrected for Lorenz, polarization, and
absorption effects. Structures were solved by direct methods
(SIR97)17 and refined on F2 by full-matrix least-squares techni-
ques. Anisotropic thermal parameters were introduced for all
non-hydrogen atoms. The thiol hydrogen (H1) of 4 was located
by difference-Fourier map and refined isotropically, while the
remaining hydrogen atoms were placed in idealized positions and
treated as riding atoms. In the crystal of 5, the large anisotropy of
thermal factors indicated the disordered structure of the Cp*
ligands, but they could not be appropriately modeled. All calcu-
lations were carried out using WinGX/SHELXL software
suites.18,19 Thermal ellipsoid plots were drawn with ORTEP3.20
Preparation of [Cp*Ru(η6-HSAr)]Cl (4). To a CH2Cl2 (5 mL)
solution of 1 0.25C6H14 (51.2 mg, 0.100 mmol) was added
3
etheral HCl (2 M solution, 0.07 mL, 0.14 mmol). After stirring
at room temperature for 1 h, volatiles were removed under
vacuum. Recrystallization from CH2Cl2 (1 mL)-hexane (7 mL)
afforded colorless plates of 4 (49.3 mg, 0.0937 mmol, 94%).
Data for 4: 1H NMR (CDCl3) δ 6.86 (t, J = 6 Hz, 1H, Ar), 5.82
(d, J = 6 Hz, 2H, Ar), 3.42 (br, 1H, SH), 1.93 (s, 15H, Cp*), 0.40
(s with 29Si satellite, 3JHSi = 6 Hz and 18H, SiMe3); 13C NMR
(CDCl3) δ 102.7 (1-position of Ar), 99.9 (2,6-positions of Ar),
96.2 (C5Me5), 91.3 (3,5-positions of Ar), 88.9 (4-position of Ar),
11.3 (C5Me5), 0.79 (s with 29Si satellite, 1JC-Si = 55 Hz, SiMe3).
Anal. Calcd for C22H37ClRuSSi2: C, 50.21; H, 7.09. Found: C,
49.97; H, 6.60.
Acknowledgment. This work was supported by a
Grant-in-Aid for Scientific Research for Young Scientists
(S) (No. 19675002) from the Ministry of Education, Culture,
Sports, Science and Technology, Japan.
Supporting Information Available: X-ray crystallographic file
in CIF format. This material is available free of charge via the
Internet at http://pubs.acs.org.
Preparation of [Cp*Ru(μ-η5:η1-SAr)RuClCp*] (5). To a THF
(17) SIR97: Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano,
G. C.; Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.;
Spagna, R. J. Appl. Crystallogr. 1999, 32, 115.
(5 mL) solution of 1 0.25C6H14 (23.0 mg, 0.0450 mmol) was
3
added [Cp*RuCl]4 (12.0 mg, 0.0110 mmol) with stirring. The
resulting wine red solution was stirred at room temperature for
12 h. Concentration of the solution and recrystallization from
€
€
(18) Sheldrick, G. M. SHELX-97; University of Gottingen: Gottingen,
Germany, 1998.
(19) Farrugia, L. J. J. Appl. Crystallogr. 1999, 32, 837.
(20) Farrugia, L. J. ORTEP3 for Windows. J. Appl. Crystallogr.
1997, 30, 565.
THF-hexane afforded wine red prisms of 5 0.5C6H14 (34.2 mg,
3
0.0425 mmol, 93%). Data for 5: 1H NMR (THF-d8) δ 5.41