Preparation of ruthenium silanethiolato complexes and their reactions with sulfur dioxide; possible models for the activation of SO2 in the homogeneously catalyzed Claus reaction

Article abstract of DOI:10.1016/S0022-328X(99)00678-6

CpRu(PPh₃)₂SSiⁱPr₃ (6a) was prepared by reacting [CpRu(PPh₃)₂(acetone)]BF₄ and NaSSiⁱPr₃. Complex 6a is substitution-labile and readily gave the mixed-ligand derivatives CpRu(PPh₃)(L)SSiⁱPr₃, where L = CO (6b), PMe₃ (6c), P(OMe)₃ (6d), upon treatment with the corresponding ligands. CpRu(dppe)SSiⁱPr₃ (6e) was obtained from complex 6a and dppe via the intermediate formation of CpRu(PPh₃)(η¹-dppe)SSiⁱPr₃. Treatment of complex 6a with one equivalent of SO₂ gave primarily unstable CpRu(PPh₃)(SO₂)SSiⁱPr₃ (6f). However, complexes 6b-e inserted one equivalent of SO₂ solely at their S-SiⁱPr₃ function to give the unstable O-silyl thiosulfito complexes CpRu(PPh₃)(L)SS(O)OSiⁱPr₃ (L = CO (8b), PMe₃ (8c), P(OMe)₃ (8d)) as well as CpRu(dppe)SS(O)OSiⁱPr₃ (8e). The S-H bonds of CpRu(PPh₃)₂SH (7a) and CpRu(dppe)SH (7b) added to PhNSO to give CpRu(PPh₃)₂SS(O)NHPh (9a) and CpRu(dppe)SS(O)NHPh (9b), respectively. The crystal structure of complex 6a was determined. Crystallographic data for 6a: triclinic, P1, a = 10.642(6) A?, b = 11.068(8) A?, c = 21.994(10) A?, α = 79.27(5)°, β= 89.22(5)°, γ = 62.32(4)°, V = 2246(2) A?³, Z = 2.

Full text of DOI:10.1016/S0022-328X(99)00678-6

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 596 (2000) 193–203
Preparation of ruthenium silanethiolato complexes and their
reactions with sulfur dioxide; possible models for the activation of
SO2 in the homogeneously catalyzed Claus reactionꢀ
Istvan Kovacs, Celine Pearson, Alan Shaver *
Department of Chemistry, McGill Uni6ersity, 801 Sherbrooke Street West, Montreal, Quebec, H3A 2K6 Canada
Received 28 September 1999; received in revised form 1 November 1999
Dedicated to Professor F.A. Cotton on the occasion of his 70th birthday.
Abstract
CpRu(PPh3)2SSiiPr3 (6a) was prepared by reacting [CpRu(PPh3)2(acetone)]BF4 and NaSSiiPr3. Complex 6a is substitution-labile
and readily gave the mixed-ligand derivatives CpRu(PPh3)(L)SSiiPr3, where L=CO (6b), PMe3 (6c), P(OMe)3 (6d), upon
treatment with the corresponding ligands. CpRu(dppe)SSiiPr3 (6e) was obtained from complex 6a and dppe via the intermediate
formation of CpRu(PPh3)(h1-dppe)SSiiPr3. Treatment of complex 6a with one equivalent of SO2 gave primarily unstable
CpRu(PPh3)(SO2)SSiiPr3 (6f). However, complexes 6b–e inserted one equivalent of SO2 solely at their SꢀSiiPr3 function to give
the unstable O-silyl thiosulfito complexes CpRu(PPh3)(L)SS(O)OSiiPr3 (L=CO (8b), PMe3 (8c), P(OMe)3 (8d)) as well as
CpRu(dppe)SS(O)OSiiPr3 (8e). The SꢀH bonds of CpRu(PPh3)2SH (7a) and CpRu(dppe)SH (7b) added to PhNSO to give
CpRu(PPh3)2SS(O)NHPh (9a) and CpRu(dppe)SS(O)NHPh (9b), respectively. The crystal structure of complex 6a was deter-
)
,
,
,
mined. Crystallographic data for 6a: triclinic, P1, a=10.642(6) A, b=11.068(8) A, c=21.994(10) A, h=79.27(5)°, i=89.22(5)°,
3
,
k=62.32(4)°, V=2246(2) A , Z=2. © 2000 Elsevier Science S.A. All rights reserved.
Keywords: Catalysis; Claus process; Ruthenium; Silanethiolate; Sulfhydryl complex; Sulfur dioxide; Insertion; Addition; Thiosulfite
chemical transformations directly on the surface of the
commercial catalyst [3].
1. Introduction
Preliminary investigations have shown that reaction
of complex 1 with SO2 gives (PPh3)2PtS3O (4), a stable
intermediate in the catalytic cycle, which then recovers
1 upon treatment with H2S [1a]. On the basis of these
results, a plausible mechanism was suggested for the
homogeneously catalyzed Claus reaction (Scheme 1)
[1a].
In particular, the activation of SO2 by complex 1 is
believed to take place via intermediates 2 and 3, which
remain undetected. The intermediacy of complex 2 was
assumed on the basis of analogies: alkylthiolato com-
plexes, including cis-(PPh3)2Pt(SiPr)2, reportedly form
similar, well-characterized SO2-adducts [1a,4]. H2S and
SO2 also form an adduct which has a considerably
Well-defined, soluble platinum complexes have been
applied successfully in recent years for modeling possi-
ble surface reactions of the industrially important, het-
erogeneously catalyzed Claus process [1]. This led to
the discovery that cis-(PPh3)2Pt(SH)2 (1) effectively cat-
alyzes the Claus reaction in homogeneous phase under
ambient conditions [1a,2]. The homogeneous system
provides a unique opportunity for studying possible
mechanisms of the catalytic cycle, which is poorly
understood due to obvious difficulties in monitoring
ꢀ Parts of this work have been presented at the 218th ACS
National Meeting, New Orleans, LA, USA, August 22–26, 1999,
Abstract INOR 208 and the 82nd CSC Conference and Exhibition,
Toronto, ON, Canada, May 30–June 2, 1999, Abstract 918.
* Corresponding author. Tel.: +1-514-3986237; fax: +1-514-
3983797.
,
longer SꢀS distance (3.67 A) than alkylthiolato adducts
,
(average 2.61 A) and contains hydrogen bridges [5]. A
similar SH···O interaction cannot be ruled out in com-
E-mail address: shaver@omc.lan.mcgill.ca (A. Shaver)
0022-328X/00/$ - see front matter © 2000 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00678-6

194
I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
(6c), P(OMe)3 (6d)) and CpRu(dppe)SSiiPr3 (6e), in-
cluding the crystal and molecular structure of
CpRu(PPh3)2SSiiPr3 (6a). Their reactions with SO2 and
spectroscopic characterization of the resulting species
are described. Results of a complementary study on the
reactions of CpRu(PPh3)2SH (7a) and CpRu(dppe)SH
(7b) with N-thionylaniline are also presented.
2. Results and discussion
2.1. Synthesis and characterization of
CpRu(PPh3)(L)SSiiPr3 (L=PPh3 (6a), CO (6b), PMe3
(6c), P(OMe)3 (6d)), CpRu(dppe)SSiiPr3 (6e),
CpRu(PPh3)2SH (7a) and CpRu(dppe)SH (7b)
Scheme 1.
plex 2 either. Furthermore, the H2SꢀSO2 adduct sup-
posedly transforms into thiosulfurous acid, HSS(O)OH,
via proton transfer to oxygen [6], which may be an
intermediate in the commercial Claus process [7]. The
same transformation is likely to take place in complex 2
to give 3, which then probably undergoes a rapid
intramolecular thioesterification reaction to generate
complex 4. The high reactivity of complex 3 may
originate from the intrinsic instability of the hydrothio-
sulfito ligand, as well as from the proximity of the
hydrosulfido function. It is reasonable to assume that
hydrothiosulfito complexes are generally unstable, given
that the aforementioned thiosulfurous acid has yet to
be independently identified [7], and no hydrothiosulfito
complex has ever been reported.
In this study, we were interested in modeling the
addition of the SꢀH bond in sulfhydryl complexes to
SO2 and eventually in obtaining evidence for the inter-
mediacy of complex 3 in the homogeneously catalyzed
Claus reaction. By proposing an analogy between the
reactions of ꢀSH and ꢀSSiR3 groups, silanethiolato
complexes appeared to be suitable models. It has been
demonstrated recently that deprotonation of sulfhydryl
complexes [8] and desilation of a silanethiolato complex
[9] gave similar products. They are also interconvert-
ible: [Ru(N)Me3(SSiMe3)]− reportedly gives [Ru(N)-
Me3(SH)]− via hydrolysis of the SꢀSi bond [9]. The
well-known oxophilic nature of silicon and the substan-
tial difference between the SiꢀS (54.2 kcal) and SiꢀO
(88.2 kcal) bond energies were expected to become the
driving force behind a formal 1,2-insertion of SO2 into
the SꢀSi bond, resulting in an O-silyl thiosulfito com-
plex. Since organic thiosulfites, RSS(O)OR%, appear to
be relatively stable compounds [10] compared to the
parent thiosulfurous acid [7], analogous O-silyl esters of
hydrothiosulfito complexes may also have some
stability.
Complexes 6a,b were prepared by reacting NaSSiiPr3
with [CpRu(PPh3)2(acetone)]BF4 and [CpRu(PPh3)-
(CO)(THF)]BF4, respectively. Complex 6b was gener-
ated alternatively from 6a via CO substitution. They
1
were characterized by elemental analysis, IR, H-, 13C-,
and 31P-NMR spectroscopy. An X-ray crystallographic
analysis of complex 6a was also carried out (vide infra).
During the synthesis and characterization of com-
plexes 6a,b some of their fundamental chemical proper-
ties were revealed. First, as expected [11], the bulky
isopropyl groups effectively stabilized the SꢀSi bond
against hydrolysis by ubiquitous water. For compari-
son, this bond in CpRu(PPh3)2SSiPh3, which contains
less bulky phenyl groups, was readily hydrolyzed by
wet acetone to give CpRu(PPh3)2SH, while complex 6a
remained stable under identical conditions. Its RuꢀS
bond, however, was readily cleaved by chloroform to
give CpRu(PPh3)2Cl. This type of reactivity is common
for CpRu(PPh3)2SR (R=alkyl, aryl) complexes [12]
owing to a high degree of nucleophilicity at the sulfur
atom. In contrast, complex 6b was stable in chlorinated
solvents, suggesting that a substantial amount of elec-
tron density is pulled off from sulfur by the p-accepting
CO ligand. Complexes 6a and 6b are also different in
that, only the former underwent ligand substitution.
Although this is common for complexes of the type
CpRu(PPh3)2SR (R=alkyl, aryl) [12], complex 6a ap-
pears to be extraordinarily susceptible for ligand substi-
tution. The facile loss of PPh3 from CpRu(PPh3)2SR
complexes has previously been attributed to a combina-
tion of steric and electronic effects [13]. In complex 6a
both are expected to be strong due to the bulk and
electron-donor capability of the silyl group. As a result,
a number of ligands (CO, phosphorus and nitrogen
donors, isonitriles, etc.) reacted with complex 6a to give
mono- or bis-substituted derivatives. However, PCy3,
which is more basic but also bulkier than PPh3 [14],
completely failed to substitute PPh3. Interestingly, while
the thiolato sulfur atom in CpRu(PPh3)2SR (R=nPr,
Here we report the synthesis and characterization of
a series of new ruthenium(II) silanethiolato complexes,
CpRu(PPh3)(L)SSiiPr3 (L=PPh3 (6a), CO (6b), PMe3

I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
195
Table 1
Selected 1H- and 13C{1H}-NMR spectroscopic data
Compound
1H-NMR data l (ppm) a
13C{1H}-NMR data l (ppm) a
iPr
Cp
CH
CH3
19.8
Cp
CpRu(PPh3)2SSiiPr3 (6a)
1.39
1.28
4.37
4.67
4.67
4.62
4.77 b
4.67
16.1
80.7
CpRu(PPh3)2SS(O)OSiiPr3 (8a)
CpRu(PPh3)2SS(O)NHPh (9a)
CpRu(PPh3)2SS(O)CH2Ph [19b]
CpRu(PPh3)2S(SO2)R (R=iPr, Me) [4b,c]
CpRu(PPh3)(CO)SSiiPr3 (6b)
83.1
83.5
82.5c
87.1
1.34
1.22
15.5
19.6
19.7
17.9
17.9
CpRu(PPh3)(CO)SS(O)OSiiPr3 (8b)
(two diastereomers)
CpRu(PPh3)(CO)SS(O)CH2Ph [19b]
(two diastereomers)
4.79
4.88
4.90
4.87
12.9
12.8
86.3
87.3
86.88
86.90
85.6 c
79.3
81.0
81.2
81.5
82.3
82.8
79.5
b
CpRu(PPh3)(CO)S(SO2)R (R=iPr, Me) [4b,c]
CpRu(PPh3)(PMe3)SSiiPr3 (6c)
CpRu(PPh3)(PMe3)SS(O)OSiiPr3 (8c)
(two diastereomers)
4.86
4.35
4.58
4.75
4.63
4.92
4.93
4.66
4.87
4.91
4.77
4.79
1.36
1.29
16.1
13.1
13.0
16.1
13.0
13.0
15.7
19.8
18.1
18.1
19.8
18.1
18.1
19.7
CpRu(PPh3)[P(OMe)3]SSiiPr3 (6d)
CpRu(PPh3)[P(OMe)3]SS(O)OSiiPr3 (8d)
(two diastereomers)
1.36
1.26
CpRu(dppe)SSiiPr3 (6e)
1.13
1.21
CpRu(dppe)SS(O)OSiiPr3 (8e)
CpRu(dppe)SS(O)NHPh (9b)
CpRu(PPh3)(SO2)SSiiPr3 (6f)
CpRu(PPh3)(PhNSO)SSiiPr3 (6g)
1.30
15.6
19.5
90.5
a Recorded in C6D6.
b R=iPr.
c R=Me, recorded in CDCl3.
iPr) substituted one or both PPh3 ligands to give thio-
lato-bridged dimers and trimers [13], no such reaction
was observed for complex 6a, possibly due to steric
hindrance by the silyl group.
with weak (1 Hz) coupling to phosphorus and separate
multiplet resonances for the o- as well as m,p-Ph pro-
tons of coordinated PPh3. The methyl and methine
carbons in the iPr groups were easily recognizable in the
13C{1H}-NMR spectra, which also exhibited signals for
the other ligands as expected. Proton and carbon NMR
Complexes 6c–e were readily prepared from 6a by
adding stoichiometric amounts of PMe3, P(OMe)3 and
dppe, respectively. The reactions were monitored by
NMR spectroscopy at room temperature and substitu-
tion of one PPh3 ligand was found to be instantaneous
and quantitative in all cases. Replacement of the second
PPh3 ligand, albeit at a slightly slower rate, also took
place when the chelating dppe was applied. Due to
the rate difference, the mixed-ligand intermediate
CpRu(PPh3)(h1-dppe)SSiiPr3, which contains a mono-
dentate dppe ligand, was detected in low concentrations
i
data for the Pr and Cp groups are compiled in Table 1.
The shielding of Cp protons and carbons is consistent
with changes in the basicity of the ligand L in the
CpRu(PPh3)(L)SSiiPr3 system. Being distant from
i
ruthenium, the Pr proton and carbon resonances are
practically insensitive to these changes. For complex 6b,
the methyl carbon resonances of the SiiPr3 group ap-
peared as two closely spaced singlets, indicating that
the chiral metal center rendered these methyl groups
diastereotopic. The spectra of complexes 6c,d did not
indicate chirality, probably because the two methyl
carbon resonances were overlapping.
1
by H- and 31P{1H}-NMR (Table 2). The final product
6e was isolated as an air-stable, orange crystalline mate-
rial and characterized by elemental analysis and NMR
spectroscopy. Complexes 6c,d were also characterized
by multinuclear NMR spectroscopy but not isolated; all
were stable in solution for at least several days at room
temperature.
31P{1H}-NMR spectra (Table 2) of complexes 6a–e
reflect changes in the ligand environment of ruthenium.
For complexes 6c,d, where two different phosphorus
ligands are present, two mutually coupled doublets
were observed with characteristic chemical shift values
and coupling constants. The strong p-acceptor CO lig-
and in complex 6b considerably deshielded the PPh3
ligand (l 51.2), similarly to the Cp ligand (Table 1).
1H-NMR spectra of complexes 6a–e exhibited a fea-
tureless upfield multiplet resonance attributable to all
i
protons of the three Pr groups attached to silicon, a
doublet for the Cp protons in the range 4.35–4.67 ppm

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I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
The chelating effect in complex 6e resulted in even more
substantial deshielding at phosphorus (l 78.6). Unlike
the Cp proton and carbon NMR data, however, the
PPh3 phosphorus resonances of complexes 6a,c,d were
inconsistent with the anticipated electronic effects of the
second phosphine or phosphite [14]. Most notably, this
signal for complex 6a shifted unusually upfield to l 37.0.
It may reflect a weakened interaction between PPh3 and
the ruthenium atom as manifested in the high substitu-
tion lability observed for this particular complex.
When an attempt was made to prepare CpRu-
(PPh3)2SSiPh3, it was found that the product of the
reaction of NaSSiPh3 and [CpRu(PPh3)2(acetone)]-BF4
was readily hydrolyzed by water present in commercial
acetone (Eq. (1)).
While this observation demonstrated the relative sensi-
tivity of CpRu(PPh3)2SSiPh3 toward hydrolysis in com-
parison with complex 6a, it also provided an alternative
method for the synthesis of hydrosulfido complex 7a
[12,15].
Complex 7b was prepared from 7a via thermal substi-
tution with dppe. NMR spectroscopic studies on the
substitution process showed that exchange of the first
PPh3 ligand readily took place to generate the mixed-
ligand species CpRu(PPh3)(h1-dppe)SH containing a
dangling ꢀPPh2 function. Unlike in the case of the
conversion of complex 6a to 6e, the substitution of the
second PPh3 ligand took place at a considerably slower
rate at room temperature to give complex 7b. This
resulted in a temporary accumulation of the mixed-lig-
and intermediate in \95% yield, which permitted its
characterization by NMR (Table 2). Being quite persis-
tent, this intermediate also reacted with a second equiv-
alent of 7a to give the diastereomeric binuclear
CpRu(PPh3)2SSiPh3+H2O
“CpRu(PPh3)2SH+Ph3SiOH
(1)
7a
Table 2
31P{1H}-NMR spectroscopic data
Compound
l (ppm) a
CpRu(PPh3)2SSiiPr3 (6a)
37.0
CpRu(PPh3)2SS(O)OSiiPr3 (8a)
CpRu(PPh3)2SS(O)NHPh (9a)
CpRu(PPh3)2SS(O)CH2Ph [19b]
CpRu(PPh3)2S(SO2)Me [4b]
41.5, 42.3 (both d, JPP=39 Hz)
41.4, 42.4 (both d, JPP=38 Hz)
41.6, 42.9 (both d, JPP=39 Hz)
41.1 b
CpRu(PPh3)(h1-dppe)SSiiPr3
−12.4 (d, JPP=27 Hz, free ꢀPPh2), 37.7 (dd, JPP=45 Hz, JPP=27 Hz,
c
complexed PPh2), 40.4 (d, JPP=45 Hz, PPh3)
78.6
81.0, 81.9 (both d, JPP=27 Hz)
80.1, 82.5 (both d, JPP=27 Hz)
51.2
CpRu(dppe)SSiiPr3 (6e)
CpRu(dppe)SS(O)OSiiPr3 (8e)
CpRu(dppe)SS(O)NHPh (9b)
CpRu(PPh3)(CO)SSiiPr3 (6b)
CpRu(PPh3)(CO)SS(O)OSiiPr3 (8b) (two diastereomers)
CpRu(PPh3)(CO)SS(O)CH2Ph [19b] (two diastereomers)
CpRu(PPh3)(CO)S(SO2)Me [4b]
52.2 (65%), 52.5 (35%)
51.4 (23%), 52.1 (77%)
b
49.2
CpRu(PPh3)(PMe3)SSiiPr3 (6c)
0.2 (d, JPP=50 Hz, PMe3), 47.0 (d, JPP=50 Hz, PPh3)
2.2 (d, JPP=43 Hz, PMe3), 54.2 (d, JPP=43 Hz, PPh3) (58%)
3.0 (d, JPP=43 Hz, PMe3), 53.3 (d, JPP=43 Hz, PPh3) (42%)
48.2 (d, JPP=80 Hz, PPh3), 147.1 (d, JPP=80 Hz, P(OMe)3)
50.9 (d, JPP=74 Hz, PPh3), 152.5 (d, JPP=74 Hz, P(OMe)3) (50%)
51.7 (d, JPP=71 Hz, PPh3), 153.1 (d, JPP=71 Hz, P(OMe)3) (50%)
43.9
CpRu(PPh3)(PMe3)SS(O)OSiiPr3 (8c) (two diastereomers)
CpRu(PPh3)[P(OMe)3]SSiiPr3 (6d)
CpRu(PPh3)[P(OMe)3]SS(O)OSiiPr3 (8d) (two diastereomers)
CpRu(PPh3)(SO2)SSiiPr3 (6f)
CpRu(PPh3)(PhNSO)SSiiPr3 (6g)
CpRu(PPh3)2SH (7a)
45.0
44.3
CpRu(PPh3)(h1-dppe)SH d
−12.6 (d, JPP=29 Hz, free ꢀPPh2), 43.6 (dd, JPP=29 Hz, JPP=39 Hz,
complexed ꢀPPh2), 48.9 (d, JPP=39 Hz, PPh3)
44.4 (d, JPP=39 Hz, dppe), 47.9 (d, JPP=39 Hz, PPh3) (50%)
45.9 (d, JPP=39 Hz, dppe), 48.2 (d, JPP=39 Hz, PPh3) (50%)
86.2
[CpRu(PPh3)SH]2(m-dppe) e (two diastereomers)
CpRu(dppe)SH (7b)
a Recorded in C6D6.
b Recorded in CDCl3.
c 1H-NMR (C6D6): 4.39 (s, Cp).
d 1H-NMR (C6D6): l −3.21 (t, JPH=7 Hz, SH), 4.30 (s, Cp).
e 1H-NMR (C6D6): l −3.57, −3.89 (both t, JPH=7 Hz, SH), 4.17, 4.20 (both s, Cp).

I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
197
2.3. Reaction of ruthenium silanethiolato complexes
with SO2
When a large excess of SO2 gas [4] was passed
through solutions of complexes 6a–e, complete con-
sumption of the starting materials and the formation of
many decomposition products was observed. Therefore,
all subsequent experiments were performed with care-
fully measured volumes of SO2 and were closely moni-
tored by multinuclear NMR spectroscopy. Complexes
6a–e reacted instantly and quantitatively with one
equivalent of SO2 at room temperature to give a single
product each. Upon gradual addition of SO2, no inter-
mediates were detected and no reactions between these
products and their starting materials were observed.
However, addition of even a small excess of SO2 gener-
ated mixtures of unidentified secondary or decomposi-
tion products. The primary products are inherently
unstable either at room temperature or at low tempera-
tures and thus could only be characterized in solution
by IR and NMR spectroscopic techniques, which pro-
vided a reasonable basis for their identification. Com-
plex 6a showed different reactivity toward SO2 than
6b–e.
Fig. 1. ORTEP view of CpRu(PPh3)2SSiiPr3 (6a). Thermal ellipsoids
are drawn at the 40% probability level. Hydrogen atoms are omitted
,
for clarity. Selected bond distances (A) and angles (°) are as follows:
RuꢀS, 2.462(3); RuꢀP(1), 2.317(3); RuꢀP(2), 2.330(2); RuꢀC(1),
2.203(7); RuꢀC(2), 2.211(8); RuꢀC(3), 2.228(7); RuꢀC(4), 2.208(7);
RuꢀC(5), 2.196(7); SꢀSi, 2.114(3); SiꢀSꢀRu, 127.63(11); P(1)ꢀ
RuꢀP(2), 99.81(8); P(1)ꢀRuꢀS, 87.75(9); P(2)ꢀRuꢀS, 87.74(8).
sulfhydryl complex [CpRu(PPh3)SH]2(m-dppe), which
1
was characterized by H and 31P{1H}-NMR (Table 2)
2.3.1. Reaction of complex 6a with SO2
but was not further investigated.
Upon injection of up to one equivalent of SO2 into
benzene-d6 or acetone-d6 solutions of complex 6a at
room temperature, a deep red color evolved instantly
and formation of a 1:1 mixture of free PPh3 and the
new ligand-substituted derivative CpRu(PPh3)(SO2)-
SSiiPr3 (6f) (Eq. (2)) was observed. At this point, no
reaction with the silanethiolato ligand had occurred.
2.2. Crystal and molecular structure of complex 6a
The structure of complex 6a is as expected and is
depicted in Fig. 1, along with the selected bond dis-
tances and angles. The RuꢀS and SꢀSi bond distances
,
are 2.462(3) and 2.114(3) A, respectively, while the
CpRu(PPh3)2SSiiPr3+SO2
RuꢀSꢀSi bond angle is 127.6°. The large PꢀRuꢀP angle
(99.8°) compared with the PꢀRuꢀS angles (both 87.7°)
seems to be an indication of steric crowding about
ruthenium. The RuꢀCring distance for carbon C3 close
to the thiolato sulfur is longer than for those at the
opposite side of the Cp ring, resulting in a slight
ring-slippage.
6a
i
D
C
CpRu(PPh3)(SO2)SSi Pr3+PPh3
(2)
6f
The phosphorus atom of complex 6f resonated at l 43.9
as a singlet and the Cp protons and carbon atoms at l
4.77 as a doublet and 90.5 as a singlet, respectively. All
were significantly deshielded compared to the respective
nuclei in 6a (Tables 1 and 2). Integrals of the proton
signals indicated only one PPh3 ligand in the molecule.
The NMR data are fully consistent with the presence of
the strong electron-accepting SO2 ligand in the coordi-
nation sphere of the ruthenium atom. These data are
comparable to those for complex 6b, indicating that CO
and SO2 have similar s-donor and p-acceptor charac-
ters [20], although the CO ligand in complex 6b pulls
more electron density from the phosphine, while the
SO2 ligand in complex 6f attracts more electron density
from the Cp ligand. Complex 6f is chiral, which renders
the methyl groups in the SiiPr3 moiety diastereotopic
but this was not detected spectroscopically, similarly to
complexes 6c,d and probably due to overlapping signals
(Table 1).
Although a number of transition metal silanethiolato
complexes have been reported [9,16–18], few contain a
single, unsupported transition metalꢀSꢀSi moiety and
only four have been characterized by X-ray crystallog-
raphy: Cp2*Ti(H)SSiHEt2 [18d], (PPh3)2CuSSi(OtBu)3
[16c,e], (PPh3)2AgSSi(OtBu)3 [16i] and tBuN=
V(SSiPh3)3 [17a]. The RuꢀSꢀSi angle in complex 6a is
the largest of all five complexes. The RuꢀS bond dis-
tance in complex 6a also exceeds those observed for a
large number of complexes of the type CpRu-
(PPh3)(L)X (L=CO, PPh3, SO2; X=SH, SR, SSR,
SSSR, SS(O)R, SS(O)2R, S(SO2)R; R=alkyl, aryl),
,
which are in the range 2.36–2.42 A [4b,c,12,19]. The
largest RuꢀSꢀY angle observed in these complexes
(110.7°) is significantly smaller than that in complex 6a.

198
I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
Complex 6f spontaneously decomposes in benzene-d6
R=alkyl, aryl) [4b,c], which typically has two strong
bands in the regions 1210–1218 cm−1 (asymmetric)
and 1060–1069 cm−1 (symmetric). The band at 1110
cm−1 is rather similar to the single band at 1080 cm−1
calculated for HSS(O)OH [7] and to that observed for
CpRu(PPh3)(CO)SS(O)CH2Ph at 1030 cm−1 [19b]. The
wCO band is shifted to higher wavenumbers compared to
that of the parent compound (1941 cm−1) due to the
electron-withdrawing effect of SO2.
to give the starting complex 6a, CpRu(PPh3)2SS(O)-
OSiiPr3 (8a) and Ph3PS, which were detected in rela-
tively significant concentrations among other products.
Complex 8a was tentatively identified on the basis of a
i
new Pr multiplet at l 1.28 and a Cp doublet at 4.67 in
the proton spectrum, as well as of two mutually cou-
pled doublets at l 41.5 and 42.3 in the 31P{1H}-NMR
spectrum. In comparison with the respective data for
complexes 6a and 6f (Tables 1 and 2), these data are
consistent with the proposed structure wherein the SO2
moiety has inserted into the SꢀSi bond. Careful integra-
tion of both the proton and phosphorus signals for
complex 8a supported the presence of two PPh3 ligands
in the molecule. The resulting O-silyl thiosulfito moiety
ꢀS(O)OSiiPr3 is chiral at the S atom and this renders
the Ph3P ligands non-equivalent, consistent with the
observed AB phosphorus resonance pattern.
The reappearance of complex 6a among the products
suggests that Eq. (2) is reversible, but the release of SO2
must be very slow compared to the forward process. It
is probably the SO2 present at equilibrium concentra-
tion, which attacks a thiolato sulfur atom to give
complex 8a. The latter is unstable and decomposes to
yet unidentified species, among them to Ph3PS. Curi-
ously, the formation of complex 8a was not accompa-
nied by that of CpRu(PPh3)(SO2)SS(O)OSiiPr3 in
detectable amounts even though complex 6f was contin-
uously present in the reaction mixture. This is sup-
ported by an independent observation that treatment of
complex 6f with SO2 did not give CpRu(PPh3)(SO2)-
SS(O)OSiiPr3.
1
A combination of H-, 13C{1H}- and 31P{1H}-NMR
spectroscopy confirmed the structures of complexes 8b–
e (Tables 1 and 2). Each of the mixed-ligand complexes
8b–d gave two very similar sets of resonances in the
NMR spectra consistent with the presence of
diastereomers as expected. The ratio of diastereomers
was 50:50 for 8d, 58:42 for 8c, and 65:35 for 8b, and the
latter showed no solvent-dependency in benzene-d6,
acetone-d6, or CDCl3. The different phosphorus envi-
ronments in complexes 8c,d gave rise to two pairs of
mutually coupled doublets in the 31P{1H}-NMR spec-
tra, while only two singlet resonances were detected for
i
complex 8b (Table 2). Comparing the Cp and Pr
proton and carbon resonances of complexes 8b–d to
those of the respective starting materials (Table 1), it is
evident that the Cp nuclei are only slightly affected
i
while the Pr group is considerably shielded, consistent
with SO2 addition. The extent of the changes in shield-
ing is quite uniform for all complexes regardless of their
different ligand sphere. These observations clearly point
to the silanethiolato ligand as the reactive site.
Complex 6e, which contains magnetically equivalent
phosphorus nuclei, was designed to model the reaction
of the thiolato sulfur of 6a with SO2 while preventing
any ligand exchange. Indeed, upon addition of one
equivalent of SO2, complex 8e was obtained as the sole
product. Since the ruthenium center in 8e is achiral, no
diastereomeric mixture is possible. However, the phos-
phine sites are non-equivalent as indicated by an AB
spin pattern in the 31P{1H}-NMR spectrum (Table 2).
This is consistent with the presence of a chiral sulfur
atom in the ꢀSS(O)OSi moiety, which renders the phos-
phorus atoms diastereotopic. This spectroscopic feature
is identical to that observed for complex 8a.
It is proposed that the reaction of complexes 6a–e
with SO2 results in a formal 1,2-insertion of SO2 into
the SꢀSi bond to give the novel O-silyl thiosulfito
complexes 8a–e of the general structure B and not
simply formation of an SO2-adduct as depicted in A
(Scheme 2). Such adducts of ruthenium thiolato com-
plexes are well known and have been characterized by
X-ray crystallography [4b,c]. However, they do not
undergo subsequent insertion into the SꢀC bond and
adduct formation is always reversible [4], which con-
trasts to the rapid and irreversible reaction of com-
plexes 6b–e with SO2. For example, complex 8b was
2.3.2. Reactions of complexes 6b–e with SO2
Unlike complex 6a, its more robust ligand-substi-
tuted derivatives 6b–e did not undergo reaction with
SO2 at the ruthenium center but instead reacted exclu-
sively at the silanethiolato ligand. The reactions were
accompanied by a color change to dark yellow or
yellow–brown and no free ligand could be detected by
NMR spectroscopy. Most reaction mixtures eventually
became green and paramagnetic in a few hours, sug-
gesting a relatively fast oxidation process. The primary
products of the reaction of SO2 with complexes 6b–e
were spectroscopically identified as the O-silyl thio-
sulfito complexes CpRu(PPh3)(L)SS(O)OSiiPr3 (L=CO
(8b), PMe3 (8c), P(OMe)3 (8d)) and CpRu(dppe)SS(O)-
OSiiPr3 (8e) (Eq. (3)).
CpRu(PPh3)(L)SSiiPr3+SO2
“CpRu(PPh3)(L)SS(O)OSiiPr3
The IR spectrum of complex 8b exhibited a broad
wSO band at 1110 cm−1 and a wCO band at 1960 cm−1
(3)
.
The former is different from that of SO2 found in the
adducts CpRu(PPh3)(L)S(SO2)R (L=CO, PPh3, SO2;

I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
199
tected. If any CpRu(PPh3)2SS(O)OH was formed, it
must be very unstable.
Attention then turned to N-thionylaniline, which ap-
peared to be a possible alternative to SO2. In order to
test the analogy between SO2 and N-thionylaniline in
the Claus reaction, a reaction of cis-(PPh3)2Pt(SH)2 (1)
with PhNSO was performed. As outlined in Scheme 1,
the reaction between complex
1 and SO2 gave
(PPh3)2PtS3O (4) and H2O. Notably, the reaction of
complex 1 with PhNSO proceeded similarly to give
complex 4 and aniline (Eq. (4)).
Scheme 2.
kept under vacuum at room temperature for one day
and no complex 6b could be detected.
cis-(PPh3)2Pt(SH)2+PhNSO“(PPh3)2PtS3O+PhNH2
1
4
(4)
Structures of type A and that proposed for complexes
8a–e (B) both possess a stereogenic sulfur, which
should render the chemically equivalent phosphorus
environments in 8a,e magnetically non-equivalent
(Table 2) as observed. This was also observed for
CpRu(PPh3)2SS(O)CH2Ph [19b] and CpRu(PPh3)2SS-
(O)NHPh (9a) as well as in CpRu(dppe)SS(O)NHPh
(9b) (vide infra), which may be viewed as functional
derivatives of complexes 8a,e and are of B-type. In
contrast, only one type of phosphorus environment was
detected in the A-type complexes CpRu(PPh3)2S(SO2)R
(R=Me, Pr, Pr, p-Tol) [4b,c] (Table 2). Furthermore,
complexes 8b–d exist as a pair of diastereomers owing
to the presence of two chiral centers in the molecules
(Tables 1 and 2) and the same behavior was reported
for CpRu(PPh3)(CO)SS(O)CH2Ph [19b]. However, the
A-type adducts CpRu(PPh3)(CO)S(SO2)R (R=Me,
iPr) [4b,c] and CpRu(PPh3)(SO2)S(SO2)-p-Tol [4c] did
not show diastereomerism in their NMR spectra. In
general, it appears that the chirality at sulfur of type A
SO2-adducts of ruthenium thiolato complexes is not
detected via NMR spectroscopy, possibly due to ex-
change. This may also be invoked in support of the
structure B suggested for complexes 8a–e. Note, how-
ever, that although all the evidence supports the forma-
tion of B-type complexes and no A-type adducts were
detected, formation of short-lived A-type intermediates
in fast equilibrium with the starting silanethiolato com-
plexes cannot be ruled out and, as suggested in Scheme
2, are probably intermediates in the formation of 8a–e.
Upon treatment of complex 7a with one equiva-
lent of N-thionylaniline at room temperature, an in-
stantaneous reaction took place giving a single product
(Eq. (5)), which was identified spectroscopically as
CpRu(PPh3)2SH+PhNSO“CpRu(PPh3)2SS(O)NHPh
7a
9a
(5)
CpRu(PPh3)2SS(O)NHPh (9a) and which decomposed
in a few hours to paramagnetic, green colored solutions
even at low temperatures. Its 31P{1H}-NMR spectrum
exhibited an AB spin pattern at l 41.4 and 42.4 (Table
2), consistent with diastereotopism due to a stereogenic
sulfur center. The proton and carbon NMR spectra
exhibited singlet resonances at l 4.64 and 83.1, respec-
tively, attributed to the Cp ligand. All the NMR data
are practically identical with the respective data for
complexes 8a and CpRu(PPh3)2SS(O)CH2Ph [19b] (Ta-
bles 1 and 2). The reaction of complex 7b with PhNSO
was carried out in a similar manner and gave
CpRu(dppe)SS(O)NHPh (9b). Its 1H- and 31P{1H}-
NMR data are similar to those of complex 8e (Tables 1
and 2). On the basis of analogies between complexes
9a,b and 8a,b and the ways they were formed, the
reactions outlined in Eqs. (3) and (5) are mutually
supportive. They also mimic the addition of the SꢀH
bond of sulfhydryl complexes to SO2 to give hydrothio-
sulfito complexes.
n
i
When reactions of N-thionylaniline were attempted
with complexes 6a,b at room temperature, 6b remained
unchanged at least for 3 days, while 6a immediately
gave red colored CpRu(PPh3)(PhNSO)SSiiPr3 (6g) via
an equilibrium ligand substitution (Eq. (6)). Unlike the
2.4. Reactions of complexes 2a,b with SO2 and PhNSO
CpRu(PPh3)2SSiiPr3+PhNSO
Since the original goal was to model the addition of
the SꢀH bond of hydrosulfido complexes to SO2, com-
plex 7a was also treated with SO2. Complex 7a readily
reacted with SO2 but no product was detected by NMR
spectroscopy. The reaction mixture remained homoge-
neous but changed color from orange to green, possibly
due to oxidation of Ru(II) to paramagnetic and NMR-
silent Ru(III). No evidence for the formation of inter-
mediates such as CpRu(PPh3)2SS(O)OH, CpRu(PPh3)-
(SO2)SH, or CpRu(PPh3)2SS(O)SRu(PPh3)2Cp was de-
6a
D
CCpRu(PPh3)(PhNSO)SSiiPr3+PPh3
(6)
6g
substitution reaction of complex 6a with SO2 (Eq. (2)),
this equilibrium favors the starting complex; at least a
fourfold increase in the concentration of PhNSO and
longer reaction times were necessary to achieve a sub-
stantial (38%) conversion of complex 6a into 6g, indi-
cating that PhNSO is a poor ligand compared with

200
I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
SO2. Complex 6g was only identified in the reaction
mixture by its Cp proton (l 4.79) and phosphorus (l
45.0) resonances, which closely resemble to those of the
SO2-substituted complex 6f (Tables 1 and 2). No evi-
dence for insertion of PhNSO into the SꢀSi bond was
detected.
changed quickly to red–orange as stirring started. The
resulting mixture was stirred at r.t. for 2 h, filtered
through Celite and evaporated to dryness. The remain-
ing solid was dissolved in warm acetone and crystal-
lized upon slow cooling as well-formed red–orange
crystals. Yield: 1.64 g (1.9 mmol, 68%). The crystalline
form is indefinitely stable in air but was found to
decompose if kept in a closed vial under acetone va-
pors. The crystals must be washed with hexane and
dried carefully for storage. Anal. Calc. for C50H56-
P2RuSSi: C, 68.23; H, 6.41; S, 3.64. Found: C, 67.78;
3. Summary
Ruthenium silanethiolato complexes of the general
formula CpRu(PPh3)(L)SSiiPr3 and CpRu(dppe)SSiiPr3
are easily accessible and all react instantly with SO2 to
give CpRu(PPh3)(SO2)SSiiPr3, when L=PPh3, as well
as CpRu(PPh3)(L)SS(O)OSiiPr3, when L=CO, PMe3,
P(OMe)3, and CpRu(dppe)SS(O)OSiiPr3 as the primary
products. This is the first observation of a formal
1,2-insertion of SO2 into the SꢀSi bond. The SꢀH bond
of CpRu(PPh3)2SH and CpRu(dppe)SH also add read-
ily to PhNSO to give the corresponding complexes
CpRuL2SS(O)NHPh. Both the anilides and the O-silyl
esters are derivatives of a hypothetical hydrosulfito
complex. These reactions support suggestions that simi-
lar intermediates may also form in the reaction of
cis-(PPh3)2Pt(SH)2 with SO2 as a step in the Claus
chemistry catalyzed by that complex.
1
H, 6.25; S, 3.68. H-NMR (acetone-d6): l 1.11 (m, 21H,
iPr), 4.27 (s, 5H, Cp), 7.13 (m, 12H, m-Ph), 7.26 (m,
6H, p-Ph), 7.41 (m, 12H, o-Ph). 13C{1H}-NMR (ace-
tone-d6): l 16.0 (CH), 19.5 (Me), 80.1 (Cp), 127.2
(m-Ph), 128.5 (p-Ph), 134.2 (o-Ph), 139.2 (t, JPC=20
Hz, ipso-Ph).
4.2. CpRu(PPh3)(CO)SSiiPr3 (6b)
A mixture of CpRu(PPh3)(CO)Cl (1.50 g, 3.0 mmol)
and AgBF4 (0.66 g, 3.4 mmol) was stirred in 100 ml of
THF at r.t. overnight. The resulting precipitateous yel-
low solution was filtered through Celite and the solid
was washed with THF until colorless washings were
obtained. NaSSiiPr3 (0.72 g, 3.4 mmol) was added and
the yellow color changed to orange almost instantly.
Stirring was continued for 2 h and the reaction mixture
was filtered again through Celite and evaporated to
dryness. The product crystallized as yellow plates from
ether or acetone at −30°C. Yield: 1.47 g (2.3 mmol,
76%). Anal. Calc. for C33H41OPRuSSi: C, 61.37; H,
6.40; S, 4.96. Found: C, 61.27; H, 6.50; S, 4.70. IR
4. Experimental
All manipulations were carried out under an inert
atmosphere (N2 or Ar), using standard Schlenk tech-
nique and a drybox. Solvents were dried and freshly
distilled under nitrogen prior to use. CpRu(PPh3)2Cl
[21], CpRu(PPh3)(CO)Cl [22], NaSSiiPr3 [11] and
NaSSiPh3 [23] were prepared according to reported
procedures. IR spectra were recorded on a Bruker IFS
48 spectrometer in solutions using a 0.1 mm NaCl cell.
1H-, 13C-, and 31P-NMR measurements were performed
on a Jeol CPF 270 spectrometer. Selected 1H- and
13C{1H}-NMR data are listed in Table 1 and the
31P{1H}-NMR data are compiled in Table 2. Elemental
analyses were carried out by the Laboratoire d’Analyse
Elementaire at the University of Montreal.
1
(CH2Cl2): wCO 1941 cm−1. H-NMR (CDCl3): l 1.04
i
(m, 21H, Pr), 4.86 (s, 5H, Cp), 7.36 (m, 9H, m,p-Ph),
7.56 (m, 6H, o-Ph). 13C{1H}-NMR (CDCl3): l 15.4
(CH), 19.40 and 19.46 (Me), 87.4 (Cp), 128.0 (d, JPC
=
10 Hz, m-Ph), 129.9 (p-Ph), 133.9 (d, JPC=10 Hz,
o-Ph), 135.7 (d, JPC=48 Hz, ipso-Ph), 205.7 (d, JPC
=
23 Hz, CO).
4.3. CpRu(PPh3)(PMe3)SSiiPr3 (6c)
This compound was generated in situ by adding
PMe3 (3.5 ml, 0.034 mmol) in two portions to complex
6a (30 mg, 0.034 mmol) dissolved in 0.7 ml of benzene-
d6. The ligand substitution process, closely monitored
by NMR spectroscopy, gave quantitative formation of
complex 6c, accompanied by a color change from or-
4.1. CpRu(PPh3)2SSiiPr3 (6a)
A suspension of CpRu(PPh3)2Cl (2.00 g, 2.75 mmol)
and AgBF4 (0.60 g, 3.1 mmol) in a solvent mixture of
100 ml THF and 30 ml acetone was stirred overnight at
room temperature (r.t.). The resulting dark yellow solu-
tion containing a yellow precipitate was filtered through
Celite and the precipitate was washed with acetone
until it became off-white. The combined washings were
concentrated to about 100 ml under vacuum. To this
NaSSiiPr3 was added (0.65 g, 3.1 mmol) and the color
1
ange to yellow upon mixing. H-NMR (C6D6): l 1.09
i
(d, JPH=9 Hz, 9H, PMe), 1.36 (m, 21H, Pr), 4.35 (br
d, 5H, Cp), 7.05 (m, 9H, m,p-Ph), 7.79 (m, 6H, o-Ph).
13C{1H}-NMR (C6D6): l 16.1 (CH), 19.8 (Me), 20.7 (d,
J
J
PC=28 Hz, PMe), 79.3 (Cp), 128.9 (p-Ph), 134.6 (d,
PC=10 Hz, o-Ph), 139.4 (d, JPC=38 Hz, ipso-Ph), the
m-Ph resonance was covered by that of the solvent.

I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
201
4.4. CpRu(PPh3)[P(OMe3)]SSiiPr3 (6d)
THF–acetone (wet). The reaction mixture became red–
orange instantly as expected for CpRu(PPh3)2SSiPh3.
However, it gradually changed color to yellow upon
stirring overnight at r.t. The precipitateous solution was
filtered through Celite and concentrated. Complex 7a
spontaneously separated as a yellow microcrystalline
solid during this process. Yield: 1.90 g (2.62 mmol,
95%). This compound has been described [15]. 1H-
NMR (C6D6): l -3.12 (t, JPH=6 Hz, 1H, SH), 4.28 (s,
5H, Cp), 6.94 (m, 18H, m,p-Ph), 7.57 (m, 12H, o-Ph).
Complex 7b was obtained in benzene-d6 solution by
heating an equimolar mixture of 7a (40 mg, 0.07 mmol)
As for complex 6c, P(OMe)3 (4 ml, 0.034 mmol) and
6a (30 mg, 0.034 mmol) were dissolved in 0.7 ml of
1
i
benzene-d6. H-NMR (C6D6): l 1.36 (m, 21H, Pr), 3.32
(d, JPH=10 Hz, 9H, POMe), 4.63 (d, JPH=1 Hz, 5H,
Cp), 7.09 (m, 9H, m,p-Ph), 7.89 (m, 6H, o-Ph).
13C{1H}-NMR (C6D6): l 16.1 (CH), 19.8 (Me), 81.5
(Cp), 127.1 (d, JPC=9 Hz, m-Ph), 128.8 (p-Ph), 134.8
(d, JPC=9 Hz, o-Ph), 138.7 (d, JPC=42 Hz, ipso-Ph),
152.6 (d, JPC=8 Hz, POMe).
4.5. CpRu(dppe)SSiiPr3 (6e)
1
and dppe. H-NMR (C6D6): l −4.22 (t, JPH=8 Hz,
1H, SH), 1.96, 2.71 (both m, 2H, CH2), 4.68 (s, 5H,
Cp), 6.96, 7.15 (both m, 8H, Ph), 7.78 (m, 4H, Ph).
Complex 6a, generated from 2.0 g CpRu(PPh3)2Cl as
described above, in the final filtered red–orange reac-
tion solution in THF–acetone was treated with bis-
diphenylphosphinoethane (dppe) (1.10 g, 2.7 mmol)
under ambient conditions. The resulting solution was
stirred for 1 day while the color changed to yellow–or-
ange. The solvent was evaporated under vacuum and
the resulting solid was washed thoroughly with a 1:1
hexane–ether solvent mixture to remove PPh3. The
product crystallized as orange needles from acetone at
low temperature. Yield: 1.32 g (1.75 mmol, 64%). Anal.
Calc. for C40H50P2RuSSi: C, 63.72; H, 6.68; S, 4.25.
4.8. CpRu(PPh3)(L)SS(O)OSiiPr3 (L=CO (8b), PMe3
(8c), P(OMe)3 (8d) and CpRu(dppe)SS(O)OSiiPr3 (8e))
Complexes 6b–d (0.034 mmol) in 0.7 ml of benzene-
d6 in an NMR sample tube were treated with one
equivalent of SO2 at r.t. by means of a gas-tight Hamil-
ton syringe. The gas was added in two to three portions
and the reactions were closely monitored by NMR
spectroscopy. Each portion of SO2 reacted instantly
and completely with concomitant proportional con-
sumption of the starting complexes. The reaction mix-
tures changed color from yellow to dark yellow or
brown. In each case, two diastereomers of the single
products 8b–d were identified. Complex 8b slowly de-
composed to various unidentified species. The reaction
mixtures containing 8c and 8d changed color to green
upon standing either at r.t. or at −30°C. The NMR
spectra of the green solutions indicated extensive de-
composition of the reaction products and formation of
Ph3PS as the only identifiable decomposition product.
1
Found: C, 62.99; H, 6.66; S, 4.35. H-NMR (acetone-
i
d6): l 0.80 (m, 21H, Pr), 2.26, 2.91 (both m, 2H,
CH2P), 4.65 (s, 5H, Cp), 7.15 (m, 4H, o-Ph), 7.29 (m,
12H, m,p-Ph), 7.88 (m, 4H, o-Ph). 13C{1H}-NMR (ace-
tone-d6): l 15.2 (CH), 19.1 (Me), 79.2 (Cp), 127.3 (t,
JPC=4 Hz, m-Ph), 127.8 (t, JPC=4 Hz, m-Ph), 128.7
(p-Ph), 128.9 (p-Ph), 132.1 (t, JPC=4 Hz, o-Ph), 133.8
(t, JPC=4 Hz, o-Ph), 137.2 (t, JPC=22 Hz, ipso-Ph).
4.6. CpRu(PPh3)(SO2)SSiiPr3 (6f)
Complex 8b: IR (CH2Cl2): wSO 1110, wCO 1960 cm−1
.
Complex 6a (40 mg, 0.045 mmol) in an NMR sample
tube in 0.7 ml of benzene-d6 was treated with 1.2 ml of
SO2 gas, added in two portions at r.t. by means of a
gas-tight Hamilton syringe. The color of the reaction
mixture became deep red instantly and the NMR spec-
tra revealed formation of complex 6f as well as one
equivalent of free PPh3. The product had significantly
1
Diastereomer (65%): H-NMR (C6D6): l 1.22 (m, 21H,
iPr), 4.79 (s, 5H, Cp), 7.00 (m, 9H, m,p-Ph), 7.50 (m,
6H, o-Ph). 13C{1H}-NMR (CDCl3): l 12.6 (CH), 17.8
(Me), 87.5 (Cp), 128.3 (d, JPC=10 Hz, m-Ph), 130.3
(p-Ph), 133.5 (d, JPC=11 Hz, o-Ph), 135.0 (d, JPC=49
Hz, ipso-Ph); the CO resonance could not be distin-
1
1
guished. Diastereomer (35%): H-NMR (C6D6): l 1.22
decomposed after 2 h at r.t. H-NMR (C6D6): l 1.30
i
i
(m, 21H, Pr), 4.88 (br s, 5H, Cp), 7.00 (m, 9H, m,p-
(m, 21H, Pr), 4.77 (d, JPH=0.5 Hz, 5H, Cp), 7.02 (m,
Ph), 7.50 (m, 6H, o-Ph). 13C{1H}-NMR (CDCl3): l
12.8 (CH), 17.9 (Me), 86.5 (Cp), 128.3 (d, JPC=10 Hz,
m-Ph), 130.3 (p-Ph), 133.5 (d, JPC=11 Hz, o-Ph),
135.1 (d, JPC=50 Hz, ipso-Ph); no CO resonance could
be observed.
9H, m,p-Ph), 7.70 (m, 6H, o-Ph). 13C{1H}-NMR
(C6D6): l 15.6 (CH), 19.5 (Me), 90.5 (Cp), 130.1 (p-Ph),
134.4 (d, JPC=9 Hz, o-Ph); the m-Ph resonance was
covered by that of the solvent, the ipso-Ph resonance
could not be distinguished unambiguously.
1
Complex 8c: Diastereomer (58%); H-NMR (C6D6):
l 1.10 (dd, JPH=7 Hz, JPH=1 Hz, 9H, PMe), 1.29 (m,
4.7. CpRu(PPh3)2SH (7a) and CpRu(dppe)SH (7a)
i
21H, Pr), 4.75 (d, JPH=1 Hz, 5H, Cp), 7.02 (m, 9H,
1
NaSSiPh.3Et2O (1.10 g, 2.8 mmol) was added at once
to a filtered solution of [CpRu(PPh3)2(acetone)]BF4 in
m,p-Ph), 7.59 (m, 6H, o-Ph). Diastereomer (42%); H-
NMR (C6D6): l 1.14 (dd, JPH=7 Hz, JPH=1 Hz, 9H,

202
I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
Table 3
was established by NMR spectroscopy. However, the
solution changed color to green and decomposition of
the product started in B1 h at r.t. The decomposition
Crystallographic data and structure refinement for complex 6a
6a
1
process was complete overnight even at −30°C. H-
Empirical formula
Formula weight
Temperature (K)
C
880.11
293 (2)
Mo–Ka, 0.70930
Triclinic
P1
10.642 (6)
11.068 (8)
21.994 (10)
79.27 (5)
89.22 (5)
62.32 (4)
2246 (2)
2
1.301
0.514
50H56P2RuSSi
NMR (C6D6): l 4.63 (br s, 5H, Cp), 6.95 (m, 18H,
m,p-Ph), 7.42 (m, 12H, o-Ph); the ꢀNHPh resonances
were partially hidden under those of PPh3.
,
Radiation, u (A)
Crystal system
4.10. Reaction of cis-(PPh3)2Pt(SH)2 (1) with
N-thionylaniline
(
Space group
,
a (A)
,
b (A)
,
c (A)
A solution of complex 1 (25 mg, 0.032 mmol) in 0.6
ml of CD2Cl2 was treated with N-thionylaniline (4 ml,
0.035 mmol). The reaction was monitored by NMR
spectroscopy at r.t. Formation of (PPh3)2PtS3O started
in 1 h and a complete reaction took place overnight.
This compound was obtained in 90% yield, accompa-
nied by small amounts of Ph3PS and Ph3PO side-prod-
ucts, which formed in an approximately 3:1 ratio. Small
amounts of a white precipitate also appeared in the
reaction mixture, accountable for the missing platinum.
Similar observations were made during the reaction of
complex 1 with SO2 under similar conditions [1a].
h (o)
i (o)
k (o)
3
,
V (A )
Z
Dcalc. (Mg m−3
)
v (mm−1
F(000)
)
920
Crystal size (mm)
Transmission range
0.38×0.25×0.08
0.90–1.00
9106
Reflections collected
Independent reflections (Rint
Goodness-of-fit on F2
Final R indices (I\2|(I))
R indices (all data)
)
8823 (0.042)
1.053
R1=0.0750, wR2=0.1452 a
R1=0.1519, wR2=0.1677 a
4.11. Reactions of complex 6a with N-thionylaniline
a R1=S(ꢀFoꢀ−ꢀFcꢀ)/SꢀFoꢀ; wR2=[S w(F2o−Fc2)2/S w(Fo2)2]1/2
.
Complex 6a (30 mg, 0.034 mmol) in 0.7 ml of ben-
zene-d6 was treated with N-thionylaniline (4 ml, 0.035
i
PMe), 1.29 (m, 21H, Pr), 4.58 (d, JPH=1 Hz, 5H, Cp),
7.02 (m, 9H, m,p-Ph), 7.59 (m, 6H, o-Ph).
1
mmol) and the reaction was monitored by H-NMR
1
Complex 8d: Diastereomer (50%): H-NMR (C6D6):
l 1.26 (m, 21H, Pr), 3.24 (d, JPH=11 Hz, 9H, POMe),
spectroscopy at r.t. The reaction solution changed color
upon mixing from orange to red and about 17% of the
starting material was consumed to give a 1:1 mixture of
complex 6g and free PPh3. Addition of two and four
equivalents of N-thionylaniline resulted in a deeper red
color and 23 and 38% conversions, respectively. Exten-
sive decomposition of the reaction mixture occurred in
3 days at r.t.
i
4.93 (d, JPH=1 Hz, 5H, Cp), 7.04 (m, 9H, m,p-Ph),
7.73 (m, 6H, o-Ph). 13C{1H}-NMR (C6D6): l 13.0
(CH), 18.1 (Me), 51.9 (d, JPC=7 Hz, POMe), 82.8
(Cp), 134.4 (d, JPC=10 Hz, o-Ph); the missing carbon
resonances could not be distinguished unambiguously.
1
Diastereomer (50%): H-NMR (C6D6): l 1.26 (m, 21H,
iPr), 3.28 (d, JPH=11 Hz, 9H, POMe), 4.92 (d, JPH=1
Hz, 5H, Cp), 7.04 (m, 9H, m,p-Ph), 7.73 (m, 6H, o-Ph).
13C{1H}-NMR (C6D6): l 13.0 (CH), 18.1 (Me), 52.0 (d,
4.12. Crystal-structure determination of complex 6a
J
PC=8 Hz, POMe), 82.3 (Cp), 134.3 (d, JPC=11 Hz,
Large red–orange crystals of complex 6a were ob-
tained from a concentrated acetone-d6 solution at room
temperature. Intensity data were collected on a Rigaku
AFC6S diffractometer. Data collection and structure
solution parameters are listed in Table 3.
Data were collected on three different crystals. The
first two were twinned and although the structure was
solved, the R factors were unacceptable at 15%. The
third crystal was thinner and showed no obvious sign of
twinning, although the faces were still not perfectly
defined. The measured intensities were weak as reflected
by R(|) of 13.9%. Data were corrected for absorption
using psi-scans (transmission range 0.90–1.00). The
structure was solved by direct methods using SHELXS-96
and difmap synthesis using SHELXL-96 [24]. All non-hy-
drogen atoms were refined anisotropically, while the
o-Ph); the missing carbon resonances could not be
distinguished unambiguously.
As described above, complex 6e (50 mg, 0.066 mmol)
and 1.6 ml of SO2 gave 8e in quantitative yield, which
readily decomposed to give a green solution. H-NMR
(C6D6): l 1.21 (m, 21H, Pr), 1.65–2.6 (complex m, 4H,
1
i
CH2P), 4.87 (s, 5H, Cp), 6.9–7.8 (complex m, 20H,
PPh).
4.9. Reactions of complexes 7a,b with N-thionylaniline
To a solution of complex 7a (30 mg, 0.05 mmol) in
0.7 ml of benzene-d6, N-thionylaniline (6 ml, :0.05
mmol) was injected in two portions. The starting yellow
solution became brown and formation of complex 9a

I. Ko6acs et al. / Journal of Organometallic Chemistry 596 (2000) 193–203
203
[8] (a) P.J. Lundmark, G.J. Kubas, B.L. Scott, Organometallics 15
(1996) 3631. (b) M.J. Carney, P.J. Walsh, F.J. Hollander, R.G.
Bergman, Organometallics 11 (1992) 761. (c) M.A. Casado,
M.A. Ciriano, A.J. Edwards, F.J. Lahoz, L.A. Oro, J.J. Perez-
Torrente, Organometallics 18 (1999) 3025.
[9] H.-C. Liang, P.A. Shapley, Organometallics 15 (1996) 1331.
[10] G. Zinner, Angew. Chem. 69 (1957) 508.
[11] E.I. Miranda, M.J. Diaz, I. Rosado, J.A. Soderquist, Tetrahe-
dron Lett. 35 (1994) 3221.
hydrogen atoms were calculated at idealized positions
using a riding model with CꢀH distances depending on
the type of hydrogen. The isotropic displacement fac-
tors, Uiso, were adjusted to a value 50% higher than Ueq
of the parent carbon atom for methyl hydrogens and
20% higher for others. The crystal structure of 6a is
shown in Fig. 1. Selected bond distances and angles are
listed in the figure captions.
[12] A. Shaver, P.-Y. Plouffe, P. Bird, E. Livingstone, Inorg. Chem.
29 (1990) 1826.
[13] A. Shaver, P.-Y. Plouffe, D.C. Liles, E. Singleton, Inorg. Chem.
31 (1992) 997.
5. Supplementary material
[14] C.A. Tolman, Chem. Rev. 77 (1977) 313.
[15] J. Amarasekera, T.B. Rauchfuss, Inorg. Chem. 28 (1989) 3875.
[16] (a) W. Wojnowski, M. Wojnowski, K. Peters, E.-M. Peters,
H.G. von Schnering, Z. Anorg. Allg. Chem. 530 (1985) 79. (b)
W. Wojnowski, M. Wojnowski, H.G. von Schnering, M. Nolte-
meyer, Z. Anorg. Allg. Chem. 531 (1985) 153. (c) B. Becker, W.
Wojnowski, K. Peters, E.-M. Peters, H.G. von Schnering, Poly-
hedron 9 (1990) 1659. (d) W. Wojnowski, B. Becker, L. Walz, K.
Peters, E.-M. Peters, H.G. von Schnering, Polyhedron 11 (1992)
607. (e) B. Becker, W. Wojnowski, K. Peters, E.-M. Peters, K.
Peters, H.G. von Schnering, Inorg. Chim. Acta 214 (1993) 9. (f)
W. Wojnowski, B. Becker, J. Saßmannshausen, E.-M. Peters,
H.G. von Schnering, Z. Anorg. Allg. Chem. 620 (1994) 1417. (g)
B. Becker, K. Radacki, A. Konitz, W. Wojnowski, Z. Anorg.
Allg. Chem. 621 (1995) 904. (h) B. Becker, K. Radacki, W.
Wojnowski, J. Organomet. Chem. 521 (1996) 39. (i) B. Becker, J.
Chojnacki, A. Konitz, W. Wojnowski, Z. Kristallogr. 213 (1998)
697. (j) J. Chojnacki, B. Becker, A. Konitz, M.J. Potrzebowski,
W. Wojnowski, J. Chem. Soc. Dalton Trans. (1999) 3063.
[17] (a) F. Preuss, H. Noichl, J. Kaub, Z. Naturforsch. 41b (1986)
1085. (b) F. Preuss, H. Noichl, Z. Naturforsch. 42b (1987) 121.
(c) F. Preuss, M. Steidel, R. Exner, Z. Naturforsch. 45b (1990)
1618.
Crystallographic data for the structure in this paper
have been deposited with the Cambridge Crystallo-
graphic Data Center as supplementary publication no.
CCDC 134376. Copies of the data can be obtained, free
of charge, on application to CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (fax: +44-1223-336033 or
e-mail: deposit@ccdc.cam.ac.uk).
Acknowledgements
We thank the Natural Sciences and Engineering Re-
search Council of Canada (NSERC) and the Quebec
Department of Education for financial support. The
assistance of Dr Anne-Marie Lebuis (McGill Univer-
sity) in obtaining the crystal structure is greatly
appreciated.
[18] (a) D. Seyferth, R.S. Henderson, L.-C. Song, Organometallics 1
(1982) 125. (b) D.M. Giolando, T.B. Rauchfuss, G.M. Clark,
Inorg. Chem. 26 (1987) 3080. (c) J. Albertsen, R. Steudel, J.
Organomet. Chem. 424 (1992) 153. (d) Z.K. Sweeney, J.L. Polse,
R.A. Andersen, R.G. Bergman, M.G. Kubinec, J. Am. Chem.
Soc. 119 (1997) 4543.
[19] (a) A. Shaver, P.-Y. Plouffe, J. Am. Chem. Soc. 113 (1991) 7780.
(b) W. Weigand, G. Bosl, C. Robl, Z. Naturforsch. 47b (1992)
39. (c) W. Weigand, G. Bosl, C. Robl, J. Kroner, Z. Natur-
forsch. 48b (1993) 627. (d) A. Shaver, P.-Y. Plouffe, Inorg.
Chem. 33 (1994) 4327.
[20] P. Conway, S.M. Garil, A.R. Manning, F.S. Stephens, Inorg.
Chem. 22 (1983) 3714.
[21] M.I. Bruce, C. Hameister, A.G. Swincer, R.C. Wallis, Inorg.
Synth. 21 (1982) 78.
[22] S.G. Davies, S.J. Simpson, J. Chem. Soc. Dalton Trans. (1984)
993.
References
[1] (a) A. Shaver, M. El-khateeb, A.-M. Lebuis, Angew. Chem. Int.
Ed. Engl. 35 (1996) 2362. (b) A. Shaver, H. Boily, A.-M. Lebuis,
Inorg. Chem. 35 (1996) 6356.
[2] (a) C & EN October 28 (1996) 29. (b) Platinum Metals Rev. 41
(1997) 32.
[3] (a) H.G. Karge, I.G. Dalla Lama, J. Phys. Chem. 88 (1984)
1538. (b) A. Datta, R.G. Cavell, J. Phys. Chem. 89 (1985) 454.
[4] (a) P.G. Eller, G.J. Kubas, J. Am. Chem. Soc. 99 (1977) 4346.
(b) W.A. Schenk, E. Dombrowski, I. Reuther, T. Stur, Z.
Naturforsch. 47b (1992) 732. (c) A. Shaver, P.-Y. Plouffe, Inorg.
Chem. 31 (1992) 1823. (d) M.Y. Darensbourg, T. Tuntulani, J.H.
Reibenspies, Inorg. Chem. 33 (1994) 611. (e) J. Darkwa, R.M.
Moutloali, T. Nyokong, J. Organomet. Chem. 564 (1998) 37.
[5] R.E. Bumgarner, D.J. Pauley, S.G. Kukolich, J. Chem. Phys. 87
(1987) 3749.
[23] L. Birkafer, A. Ritter, H. Galler, Chem. Ber. 96 (1963) 3289.
[24] G.M. Sheldrick, SHELXL-96, Program for Structure Analysis,
University of Gottingen, Germany, 1996.
[6] Y. Drozdova, R. Steudel, Chem. Eur. J. 1 (1995) 193.
[7] K. Miaskiewicz, R. Steudel, J. Chem. Soc. Dalton Trans. (1991)
2395.
.