Multifaceted chemistry of [(Cymene)RuCl2]2 and PCy3

Article abstract of DOI:10.1021/om900374e

The reaction of [(cymene)RuCl₂]₂ (1) with PCy ₃ was investigated using different stoichiometries and reaction conditions. Whereas a mixture of complex 1 and 2 equiv of PCy₃ in methanol gave the known adduct [(cy

Full text of DOI:10.1021/om900374e

Organometallics 2009, 28, 4519–4526 4519
DOI: 10.1021/om900374e
Multifaceted Chemistry of [(Cymene)RuCl2]2 and PCy3
ꢀ
Euro Solari, Sebastien Gauthier, Rosario Scopelliti, and Kay Severin*
ꢀ
ꢀ ꢀ ꢀ
Institut des Sciences et Ingenierie Chimiques, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015
Lausanne, Switzerland
Received May 11, 2009
The reaction of [(cymene)RuCl2]2 (1) with PCy3 was investigated using different stoichiometries
and reaction conditions. Whereas a mixture of complex 1 and 2 equiv of PCy3 in methanol gave the
known adduct [(cymene)RuCl2(PCy3)] (2), the utilization of 4 equiv gave the hydrido complex
[(cymene)RuHCl(PCy3)] (3) along with the phosphonium salt [PCy3(CH2OH)]Cl (4). Prolonged
heating of 1 and 4 equiv of PCy3 in methanol under argon resulted in the formation of complex
[RuHCl(CO)(PCy3)2] (5). Dinuclear, chloro-bridged complexes were generated when 1 was reacted
with only 1 equiv of PCy3. In a mixture of THF and allyl alcohol, the carbonyl complex [(cymene)Ru-
(μ-Cl)3RuCl(CO)(PCy3)] (6) was formed. In dioxane, however, intramolecular C-H activation of the
PCy3 ligand was observed, resulting in the formation of [(cymene)Ru(μ-Cl)3RuCl{PCy2(C6H9)}] (7).
When the reaction was performed under an atmosphere of H2, the dihydrogen complex [(cymene)Ru-
(μ-Cl)3RuCl(H2)(PCy3)] (8) could be isolated. An inert trinuclear cluster of the formula
[RuCl2(PCy3)]3 (10) was formed when 1 was heated with 2 equiv of PCy3 in THF. The complexes
3, 6, 7, 8, and 10 as well as the phosphonium salt 4 were characterized by single-crystal X-ray
analysis.
Introduction
demanding phosphine ligands such as PCy3 are employed,
the cymene π-ligand can be cleaved off by photochemical or
thermal activation (Scheme 1). The resulting ruthenium
complexes have been employed as catalysts for ring-closing
metathesis (RCM)7 and for ring-opening metathesis polym-
erization (ROMP) reactions8,9 as well as for atom transfer
radical addition (ATRA) and polymerization (ATRP) reac-
tions (Scheme 1).10
So far, there is very limited knowledge about what type of
complexes are formed upon liberation of the π-ligand. In the
context of studies about Ru-catalyzed radical reactions we
have recently observed that a partial displacement of the
arene ligand with PCy3 may lead to the formation of
The chloro-bridged complex [(cymene)RuCl2]2 (1) was
first described in 1972.1 It is easily accessible from R-phel-
2
landrene and RuCl3(H2O)n and has become a frequently
used starting material in organometallic,3 medicinal
inorganic,4 and supramolecular5 chemistry. Complex 1 re-
acts with monodentate PR3 ligands to give adducts of the
general formula [(cymene)RuCl2(PR3)].1,6 When sterically
*Corresponding author. E-mail: kay.severin@epfl.ch.
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r
2009 American Chemical Society
Published on Web 07/02/2009
pubs.acs.org/Organometallics

4520 Organometallics, Vol. 28, No. 15, 2009
Solari et al.
Scheme 1
halogeno-bridged complexes of the formula [(arene)-
Ru(μ-Cl)3RuCl(L)(PCy3)] (L = μ-N2 or η2-C2H4).11,12 In
the following we describe more detailed investigations about
the reaction of complex 1 with PCy3. It is shown that
mononuclear hydrido complexes are formed in alcoholic
solvents. Partial arene displacement in nonprotic organic
solvents results in the generation of highly reactive dinuclear
complexes, which may even promote C-H activation. The
complete displacement of the cymene ligand, on the other
hand, gives a trinuclear cluster of low reactivity.
Figure 1. Graphic representation of the molecular structure of
˚
complex 3 in the crystal. Selected bond lengths (A) and angles
(deg): Ru1-Cl1 2.4393(12), Ru1-H1 1.48(5), Ru1-P1 2.3222
(12); P1-Ru1-Cl1 89.64(4), P1-Ru1-H1 75.8(18), Cl1-
Ru1-H1 88.9(17).
Results and Discussion
In a first set of experiments, we have investigated the
reaction of the dimer 1 with PCy3 in methanol. When 1
was reacted with 2 equiv of PCy3, the known mononuclear
complex [(cymene)RuCl2(PCy3)] (2) was obtained in 80%
yield in the form of a microcrystalline material (Scheme 2).
When 4 equiv with respect to the dimer 1 were used, an
orange powder precipitated. This complex turned out
to be the hydrido complex [(cymene)RuHCl(PCy3)] (3)
(Scheme 2), as evidenced by NMR spectroscopy and a
single-crystal X-ray analysis (Figure 1). An alternative
synthesis for complex 3 was recently described by Demerse-
man et al.13,14 They have obtained 3 in a multistep synthesis
with a final ligand exchange reaction between [(cymene)-
RuCl2(PCy3)] and the dihydrido complex [(cymene)-
RuH2(PCy3)] (yield: 39%). The much simpler preparation
of complex 3 from [(cymene)RuCl2]2 and PCy3 should thus
be of interest.
Scheme 2
Scheme 3
To elucidate the fate of the excess PCy3 in our reaction, we
have investigated the filtrate. Evaporation of the methanol
followed by recrystallization from hot toluene gave the
phosphonium salt 4, which was characterized by NMR
spectroscopy and a crystallographic analysis (picture not
shown). It is known that hydroxymethylphosphonium salts
are easily formed from tertiary phosphines, formaldehyde,
and HCl.15 The formation of 4 can thus be rationalized by
assuming a Ru-induced oxidation of methanol to formalde-
hyde via a β-hydride elimination of a methoxy complex with
concomitant reaction of CH2O and HCl with PCy3.
The molecular structure of complex 3 in the crystal is
shown in Figure 1. It displays the expected “piano stool”
geometry with a facial orientation of the hydrido, the chloro,
and the PCy3 ligand. The hydrido ligand was located crystal-
lographically, and the Ru-H bond distance was found to be
˚
˚
1.48(5) A. The lengths of the Ru-P bond (2.3222(12) A) and
˚
of the Ru-Cl bond (2.4393(12) A) are within the expected
range.14a
When the reaction of 1 with 4 equiv of PCy3 was performed
under more forcing conditions (60 °C, 48 h), the cymene
π-ligand was cleaved off and the hydrido complex [RuHCl-
(CO)(PCy3)2] (5) was obtained in 70% yield (Scheme 3).
Several synthetic routes for complex 5 have already been
described. Moers and co-workers reported that 5 can be
obtained along with the dichloro complex [RuCl2(CO)-
(PCy3)2] by reacting RuCl3(H2O)n with PCy3 in 2-methox-
yethanol.16 In 1999, Yi et al. described a high-yield synthesis
of 5 starting from [RuCl2(cod)]2.17 However, the group of
(11) (a) Wolf, J.; Thommes, K.; Briel, O.; Scopelliti, R.; Severin, K.
Organometallics 2008, 27, 4464–4474. (b) Haas, M.; Solari, E.; Nguyen,
Q. T.; Gauthier, S.; Scopelliti, R.; Severin, K. Adv. Synth. Catal. 2006, 348,
439–442. (c) Quebatte, L.; Solari, E.; Scopelliti, R.; Severin, K. Organome-
tallics 2005, 24, 1404–1406. (d) Quebatte, L.; Haas, M.; Solari, E.; Scopelliti,
R.; Nguyen, Q. T.; Severin, K. Angew. Chem., Int. Ed. 2005, 44, 1084–1088.
(12) For structurally related complexes with N-heterocyclic carbene
ligands instead of PCy3 see: Sauvage, X.; Borguet, Y.; Noels, A. F.;
Delaude, L.; Demonceau, A. Adv. Synth. Catal. 2007, 349, 255–265.
ꢀ
(13) Demerseman, B.; Mbaye, M. D.; Semeril, D.; Toupet, L.;
Bruneau, C.; Dixneuf, P. H. Eur. J. Inorg. Chem. 2006, 1174–1181.
(14) For other examples of monohydrido complexes of the general
formula [(arene)RuHCl(PR3)] see: (a) Dyson, P. J.; Chaplin, A. B.
Organometallics 2007, 26, 4357–4360. (b) Miyaki, Y.; Onishi, T.; Ogoshi,
S.; Kurosawa, H. J. Organomet. Chem. 2000, 616, 135–139. (c) Bennett,
M. A.; Huang, T.-N.; Latten, J. L. J. Organomet. Chem. 1984, 272, 189–205.
(15) Henderson, W.; Olsen, G. M. Polyhedron 1996, 15, 2105–2115.
(16) (a) Moers, F. G.; Ten Hoedt, R. W. M.; Langhout, J. P. J.
Organomet. Chem. 1974, 65, 93–98. (b) Moers, F. G.; Langhout, J. P. Rec.
Trav. Chim. Pays-Bas 1972, 91, 591–600.
(17) Yi, C. S.; Lee, Chen, Y. Organometallics 1999, 18, 2043–2045.

Article
Organometallics, Vol. 28, No. 15, 2009 4521
Fogg has recently reported that the synthesis via [RuCl2-
(cod)]2 tends to give small amounts of impurities, which are
difficult to remove.18 As a result, they have devised an
improved route, which starts with hydride complex
[RuHCl(CO)(PPh3)].18 It is interesting to note that complex
5 can also be formed by decomposition of the metathesis
catalysts [RuCl2(dCHR)(PCy3)2] (R=Ph, OEt).19 The spe-
cial attention that complex 5 has received over the last years
is mainly due to the fact that it can be used as a potent
catalyst for numerous organic transformations. For exam-
ple, complex 5 has been used as a catalyst for the hydrogena-
tion of alkenes,20 for the hydrovinylation of vinylarenes,21
for the silylation of terminal alkenes22 and alkynes,23 for the
synthesis of alkynylgermanes,24 for the isomerization of
double bonds,19a and for the coupling of cyclic amines and
alkenes.25 Our new synthesis of complex 5 should be of
interest because it is a simple one-step procedure staring
from commercially available 1.
Figure 2. Graphic representation of the molecular structure of
complex 6 in the crystal. The solvent molecule (CH2Cl2) is not
˚
shown for clarity. Selected bond lengths (A) and angles (deg):
We have also investigated the reaction of 1 with PCy3 in
various nonprotic solvents. Heating complex 1 with 1 equiv
of PCy3 in dibutyl ether at 110 °C for 4 h resulted in the
formation of an orange precipitate (6). IR spectroscopic
investigation of this precipitate showed a strong peak at
ν=1951 cm-1, indicating the presence of a complex with a CO
ligand. This was supported by the 13C NMR spectrum, which
showed a peak at δ=205.2 ppm. The peak appeared as a
doublet (J=18 Hz), suggesting that the CO ligand is situated
next to a PCy3 ligand. This was confirmed by a crystal-
lographic analysis, which established that 6 is a dinuclear
complex of the formula [(cymene)Ru(μ-Cl)3RuCl(CO)-
(PCy3)] (Figure 2).26
Ru1-Cl1 2.552(4), Ru1-Cl2 2.514(5), Ru1-Cl3 2.424(5),
Ru1-Cl4 2.381(5), Ru1-P1 2.327(4), Ru1-C1 1.848(15),
C1-01 1.107(16), Ru1 Ru2 3.301(6); P1-Ru1-C1 89.7(4),
3 3 3
P1-Ru1-Cl4 91.85(16), P1-Ru1-Cl1 176.20(13), Ru1-C1-
O1 177.1(13).
Scheme 4
The source of the CO ligand in complex 6 was puzzling. We
therefore repeated the reaction with freshly distilled dibutyl
ether, and we were unable to reproduce the formation of
Scheme 5
(18) Beach, N. J.; Dharmasena, U. L.; Drouin, S. D.; Fogg, D. E.
Adv. Synth. Catal. 2008, 350, 773–777.
(19) (a) Dinger, M. B.; Mol, J. C. Organometallics 2003, 22, 1089–
1095. (b) Trnka, T. M.; Morgan, J. P.; Sanford, M. S.; Wilhelm, T. E.; Scholl,
M.; Choi, T.-L.; Ding, S.; Day, M. W.; Grubbs, R. H. J. Am. Chem. Soc.
2003, 125, 2546–2558. (c) Louie, J.; Grubbs, R. H. Organometallics 2002,
21, 2153–2164. (d) Drouin, S. D.; Zamanian, F.; Fogg, D. E. Organome-
tallics 2001, 20, 5495–5497.
(20) (a) Beach, N. J.; Blacquiere, J. M.; Drouin, S. D.; Fogg, D. E.
Organometallics 2009, 28, 441–447. (b) de Souza, R. F.; Rech, V.; Dupont, J.
Adv. Synth. Catal. 2002, 344, 153–155. (c) Lee, H. M.; Smith, D. C. Jr.; He,
Z.; Stevens, E. D.; Yi, C. S.; Nolan, S. P. Organometallics 2001, 20, 794–797.
(d) Yi, C. S.; Lee, D. W.; He, Z.; Rheingold, A. L.; Lam, K.-C.; Concolino,
T. E. Organometallics 2000, 19, 2909–2915. (e) Yi, C. S.; Lee, D. W.
Organometallics 1999, 18, 5152–5156.
complex 6. Analysis of the original dibutyl ether by GC-MS
revealed the presence of small amounts of butyl peroxide and
1-butanol. Attempts to prepare 6 by a reaction in a mixture
of freshly distilled dibutyl ether and 1-butanol (9:1) failed,
however. Searching for a reproducible synthetic pathway we
finally found that heating 1 and 2 equiv of PCy3 in a mixture
of THF and allyl alcohol formed complex 6 in good yield
(Scheme 4). The mechanism of this carbonylation reaction
may involve the metal-catalyzed isomerization of allyl alco-
hol into propanal, but more detailed mechanistic studies
would be needed to clarify this point. It is noteworthy,
however, that when the reaction was performed in a mixture
of THF and 1-butanol instead of allyl alcohol, the desired
CO complex 6 was not obtained.
(21) Sanchez, R. P.; Connell, B. T. Organometallics 2008, 27, 2902–
2904.
(22) (a) Dudziec, B.; Marciniec, B. Organometallics 2008, 27, 5598–
5604. (b) Jankowska, M.; Shuvalova, O.; Bespalova, N.; Majchrzak, M.;
Marciniec, B. J. Organomet. Chem. 2005, 690, 4492–4497. (c) Itami, Y.;
Marciniec, B.; Kubicki, M. Organometallics 2003, 22, 3717–3722. (d) Yi,
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3320–3322. (b) Quebatte, L.; Scopelliti, R.; Severin, K. Eur. J. Inorg. Chem.
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When complex 1 was heated with 1 equiv of PCy3 in
dioxane at 70 °C for three days, a new compound was formed
(7) (Scheme 5). The NMR data of this compound were rather
complex: the 31P NMR spectrum showed two singlets at 73.9
and 73.2 ppm with the relative intensity of 5:3. A double set
of signals with a major and a minor component was also
observed for the 1H and the 13C NMR spectra. The presence
of 2 ꢀ 4 signals for the aromatic CH protons of the cymene
π-ligand indicated that complex 7 was chiral. A striking
1
feature was the presence of H NMR signals in the range

4522 Organometallics, Vol. 28, No. 15, 2009
Solari et al.
Scheme 6
Scheme 7
Figure 3. Graphic representation of the molecular structure of
complex 7 in the crystal. The disorder of the cyclohexene ring is
indicated by dotted lines. The solvent molecule (dioxane) is not
˚
shown for clarity. Selected bond lengths (A) and angles (deg):
Ru1-Cl1 2.4902(13), Ru1-Cl2 2.4253(12), Ru1-Cl3 2.5561
(14), Ru1-Cl4 2.3942(12), Ru1-P1 2.2402(14), Ru1-C4 2.179
(6), Ru1-C3 2.185(5), C3-C4 1.361(8), Ru1 Ru2 3.2926(6);
3 3 3
P1-Ru1-Cl4 94.32(5), P1-Ru1-Cl1 100.78(5), P1-Ru1-Cl3
174.06(5).
likely that these diastereoisomers are responsible for the
double set of signals that was observed by NMR spectros-
copy. The bond lengths observed for the η2-bound olefin in
complex 7 (Ru1-C4 2.179(6), Ru1-C3 2.185(5), C3-C4
1.361(8)) are similar to what was observed for a previously
characterized Ru{PCy2(η2-C6H9)} complex.28b
4.40-4.69 ppm, which pointed to the presence of metal-
bound olefinic protons.
An explanation for the NMR data was provided by the
result of a crystallographic analysis. Complex 7 shows a
dinuclear, chloro-bridged structure, which is similar to that
of 6 (Figure 3). Instead of the CO ligand, a η2-bound
cyclohexene group completes the coordination sphere of
the Ru center. The latter is derived from the PCy3 ligand,
which has undergone a partial dehydrogenation reaction.
The acceptorless dehydrogenation of phosphine ligands has
been observed occasionally for tricyclopentylphosphine
complexes.27 The analogous reaction with PCy3 is known
to be much more difficult and generally requires the addition
of hydrogen acceptors such as CH2dCHtBu.27c,27f,28
The crystallographic analysis revealed some disorder of
the η2-bound cyclohexene group. The dehydrogenated
PCy2(C6H9) ligand is chiral, and the Ru1 center represents
a stereogenic center. Consequently, two diastereoisomers are
possible. In the main isomer in the crystal (90%), the Ru-
bound C3 atom is two carbon atoms apart from the P atom,
whereas in the minor isomer (10%), the C3 atom is three
carbon atoms apart from the P atom (Figure 3). It seems
The clean formation of complex 7 via C-H activation of
the cyclohexane group is evidence that the putative inter-
mediate [(cymene)Ru(μ-Cl)3RuCl(PCy3)], which is formed
by displacement of one cymene ligand of complex 1 by one
PCy3 ligand, is highly reactive. Attempts to isolate this
intermediate were so far not successful. However, it was
possible to capture this intermediate by addition of dihydro-
gen. Thus, when a solution of complex 1 was heated with 1
equiv of PCy3 in THF at 60 °C under an atmosphere of
dihydrogen, the dihydrogen complex [(cymene)Ru-
( μ-Cl)3RuCl(H2)(PCy3)] (8) could be isolated in 50%
yield (Scheme 6). An alternative, much cleaner formation
of complex 8 was achieved by treating the ethylene
complex 911c with dihydrogen. In this case, the isolated yield
of complex 8 was 90%.
The 1H NMR spectrum of complex 8 in CD2Cl2 shows a
doublet at -11.83 ppm, which can be attributed to the
dihydrogen ligand. The H2 ligand is not bound very strongly:
when solutions of complex 8 were stored under reduced
pressure, the NMR signals of 8 gradually disappeared with
the concomitant appearance of signals for several unidenti-
fied complexes. We have also attempted to convert the olefin
complex 7 into the dihydrogen complex 8 by treatment with
H2, but complex 7 did not react with H2, even at elevated
temperatures.
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B.; Chaudret, B. Organometallics 1996, 15, 1427–1434. (b) Arliguie, T.;
Chaudret, B.; Chung, G.; Dahan, F. Organometallics 1991, 10, 2973–2977.
(c) Arliguie, T.; Chaudret, B.; Jalon, F. A.; Otero, A.; Lopez, J. A.; Lahoz, F. J.
Organometallics 1991, 10, 1888–1896.
The molecular structure of complex 8 in the crystal
resembles that of the CO complex 6. As expected, the Ru-
Cl bond trans to the dihydrogen ligand is slightly shorter
than what was observed for the Ru-Cl bond trans to the CO
˚
ligand of complex 6 (2.4532(16) vs 2.514(5) A).
Next, we have examined whether it is possible to comple-
tely remove the cymene π-ligands of complex 1 in a nonprotic

Article
Organometallics, Vol. 28, No. 15, 2009 4523
Figure 4. Graphic representation of the molecular structure of
complex 8 in the crystal. The solvent molecules (1.5 toluene) are
˚
not shown for clarity. Selected bond lengths (A) and angles
Figure 5. Graphic representation of the molecular structure of
complex 10 in the crystal. The solvent molecules (6 THF) are not
(deg): Ru1-Cl1 2.4532(16), Ru1-Cl2 2.4194(19), Ru1-Cl3
2.5468(18), Ru1-Cl4 2.3902(19), Ru1-P1 2.2871(19), Ru1-
˚
shown for clarity. Selected bond lengths (A) and angles (deg):
Ru1-Cl1 2.3908(14), Ru1-Cl2 2.4150(14), Ru1-Cl5 2.3712
(14), Ru1-Cl6 2.3649(15), Ru1-P1 2.4075(15), Ru1-Ru2
2.5885(6), Ru2-Ru3 2.5947(6), Ru1-Ru3 2.5944(6); Cl1-
Ru1-Cl2 82.03(5), Cl5-Ru1-Cl2 155.23(5), Cl2-Ru1-P1
92.69(5).
H1A 1.67(7), Ru1-H1B 1.79(7), Ru1 Ru2 3.2747(9); P1-
3 3 3
Ru1-C1 98.84(6), P1-Ru1-Cl4 91.68(7), P1-Ru1-Cl2 96.55
(6), Cl4-Ru1-C2 170.66(6).
solvent. This was achieved by heating a solution of complex 1
with 2 equiv of PCy3 in THF for two days (Scheme 7). The
product mixture was purified by column chromatography
(CHCl3, silica) to give complex 10 in 65% yield.
bidentate phosphine ligands such as PPh3, diphenyl-
phosphinobutane, or 2,20-bis(diphenylphosphino)-1,10-bi-
naphthyl (BINAP), even at elevated temperatures (70 °C,
toluene, 3 h).
The complete loss of the cymene ligand was confirmed by
NMR spectroscopy: the spectra showed only the signals for
the PCy3 ligand. A crystallographic analysis revealed that
complex 10 possesses a trinuclear structure, in which the
three RuCl2(PCy3) fragments are connected by Ru-Ru
bonds and by bridging chloro ligands (Figure 5). The Ru-
Conclusion
In order to better understand the chemistry of the common
catalyst precursor {1 þ n PCy3}, we have investigated the
reaction of complex 1 with PCy3 using different stoichiome-
tries and reaction conditions. When methanol was used as
the solvent, the hydrido complexes [(cymene)RuHCl(PCy3)]
(3) and [RuHCl(CO)(PCy3)2] (5) were obtained. Different
synthetic routes have been described for both compounds,
but our facile one-step procedures are attractive alternatives.
This is particularly relevant for the 16 e- complex 5, which is
a potent catalyst for different organic transformations.
In nonprotic solvents, completely different reaction pro-
ducts were isolated. When 1 was reacted with 1 equiv of
PCy3, dinuclear complexes were formed. Of special interest is
the olefin complex 7, which contains a partially dehydroge-
nated PCy3 ligand. This complex is indirect evidence that the
intermediate species formed after PCy3-induced release of
one cymene π-ligand is highly reactive. The reactivity of the
dinuclear complexes is in contrast to the inert cluster
[RuCl2(PCy3)]3 (10), which was obtained by complete re-
moval of the cymene ligands. The fact that such an inert
cluster can form by reacting 1 with PCy3 should be consid-
ered for catalytic applications, as the formation of 10 might
represent a possible deactivation pathway for the catalyst.
˚
Ru distances (2.5885(6), 2.5947(6), and 2.5944(6) A) point to
very strong metal-metal interactions. For comparison, the
Ru-Ru bonds in trinuclear hydrido complexes of the gen-
eral formula [Ru3H3(O)(arene)3]þ are approximately 0.2 A
˚
longer (Ru-Ru=2.74-2.81 A).29 The compact Ru3 core also
˚
˚
shows rather short Ru-Cl bonds (Ru-Cl=2.36-2.42 A).
The dinuclear complexes 6, 7, and 8, for example, have Ru-
˚
(μ-Cl) distances between 2.42 and 2.56 A. At 2.4075(15),
˚
2.4014(15), and 2.4007(15) A, the Ru-P bonds of 10 are
within the expected range.30
Structurally related trimers with the sterically very de-
manding phosphine ligands PAd2Bu and PtBu2Cy have
recently been described.31 These trimers were found to be
very inert toward addition or substitution reactions.
Similarly, complex 10 did not react with monodentate or
€
(29) (a) Vieille-Petit, L.; Therrien, B.; Buryak, A.; Severin, K.; Suss-
Fink, G. Acta Crystallogr. 2004, E60, m1909–m1911. (b) Vieille-Petit, L.;
Therrien, B.; S€uss-Fink, G. Inorg. Chim. Acta 2003, 355, 394–398. (c)
Vieille-Petit, L.; Therrien, B.; S€uss-Fink, G.; Ward, T. R. J. Organomet.
Chem. 2003, 684, 117–123. (d) Faure, M.; Jahncke, M.; Neels, A.; Stoeckli-
Evans, H.; S€uss-Fink, G. Polyhedron 1999, 18, 2679–2685.
(30) (a) Jung, S.; Ilg, K.; Brandt, C. D.; Wolf, J.; Werner, H. Eur. J.
Inorg. Chem. 2004, 469–480. (b) Louie, J.; Grubbs, R. H. Organometallics
2002, 21, 2153–2164. (c) F€urstner, A.; Ackermann, L.; Gabor, B.; Goddard,
R.; Lehmann, C. W.; Mynott, R.; Stelzer, F.; Thiel, O. R. Chem.;Eur. J.
2001, 7, 3236–3253. (d) Coalter, J. N.III; Bollinger, J. C.; Huffman, J. C.;
Experimental Section
General Procedures. The synthesis of all complexes was
performed under an atmosphere of dry dinitrogen or argon,
using standard Schlenk techniques or a glovebox. The solvents
were either dried using a solvent purification system from
ꢀ
Werner-Zwanziger, U.; Caulton, K. G.; Davidson, E. R.; Gerard, H.; Clot, E.;
Eisenstein, O. New J. Chem. 2000, 24, 9–26.
(31) Gauthier, S.; Scopelliti, R.; Severin, K. Organometallics 2005, 24,
5792–5794.

4524 Organometallics, Vol. 28, No. 15, 2009
Solari et al.
Innovative Technologies, Inc., or distilled from appropri-
ate drying agents. The complexes [(cymene)RuCl2]2 (1)1,2 and
[(cymene)Ru(μ-Cl)3RuCl(C2H4)(PCy3)] (9)11c were prepared
according to a literature procedure. PCy3 (97%) was purchased
[(Cymene)Ru(μ-Cl)3RuCl{PCy2(C6H9)}] (7). A suspension of
complex 1 (1.00 g, 1.63 mmol) and PCy3 (457 mg, 1.63 mmol) in
dioxane (50 mL) was heated to 70 °C under argon. After 3 days,
the mixture was cooled to room temperature and concentrated
to 30 mL. The addition of hexane (100 mL) resulted in the
formation of an orange-brown precipitate, which was filtered,
washed with hexane, and dried under vacuum (yield: 865 mg,
70%). The complex exists in the form of two isomers; the major
isomer is labeled with an A, the minor isomer with a B. 1H NMR
(400 MHz, CD2Cl2): δ (ppm) 1.10-2.51 (m, PCy3, A þ B), 1.34
(d, 3J=7 Hz, CH(CH3)2, B), 1.36 (d, 3J=7 Hz, CH(CH3)2, A),
2.26 (s, CH3, B), 2.28 (s, CH3, A), 2.89-3.00 (m, CH(CH3)2, A þ
1
from Strem Chemicals. The H and 13C spectra were recorded
on a Bruker Advance DPX 400 or a Bruker Advance 200
spectrometer using the residual protonated solvents as internal
standards. All spectra were recorded at room temperature.
[(Cymene)RuCl2(PCy3)] (2). A mixture of complex 1 (50 mg,
82 μmol) and PCy3 (46 mg, 164 μmol) in MeOH (5 mL) was
heated under dinitrogen for a few minutes until a clear solution
was obtained. On cooling to room temperature, the product
precipitated in the form of red microcrystals. They were col-
lected, washed with pentane, and dried under vacuum (yield:
96 mg, 80%). Anal. Calcd (%) for C28H47Cl2PRu: C 57.33, H
8.07. Found: C 57.15, H 8.05. The 1H, 13C, and 31P NMR
spectra correspond to what has been described previously.8d
[(Cymene)RuHCl(PCy3)] (3). A solution of complex 1
(100 mg, 163 μmol) in MeOH (10 mL) was added to a solution
of PCy3 (183 mg, 650 μmol) in MeOH (10 mL) under dinitrogen,
and the mixture was stirred for 12 h at room temperature. The
product precipitated in the form of an orange powder, which
was isolated by filtration, washed with pentane, and dried
under vacuum (yield: 117 mg, 65%). Anal. Calcd (%) for
C28H48ClPRu: C 60.90, H 8.76. Found: C 60.69, H 8.86. The
1H, 13C, and 31P NMR spectra correspond to what has been
described previously.13
3
B), 4.40-4.69 (m, CHolefin, A þ B), 5.37 (d, J=6 Hz, CH,
cymene, B), 5.41 (d, 3J=6 Hz, CH, cymene, A), 5.42 (d, 3J=6 Hz,
CH, cymene, B), 5.47 (d, 3J=6 Hz, CH, cymene, A), 5.55 (d, 3J =
6 Hz, CH, cymene, B), 5.61 (d, 3J=6 Hz, CH, cymene, A), 5.63
(d, 3J=6 Hz, CH, cymene, B), 5.66 (d, 3J=6 Hz, CH, cymene, A).
13C NMR (101 MHz, CD2Cl2): δ (ppm) 18.69-38.50 (m, CH3,
CH(CH3)2, PCy3, CH(CH3)2, A þ B), 71.16 (d, JP,C=2 Hz,
C
C
olefin, B), 73.76 (d, JP,C=2 Hz, Colefin, A), 77.39 (d, JP,C=2 Hz,
olefin, B), 78.31, 78.69, 79.06, 79.74 (CH, cymene, A), 78.27,
78.49, 78.79, 79.57 (CH, cymene, B), 80.74 (d, JP,C=2 Hz, Colefin
,
A), 96.54, 96.70, 100.71, 100.82 (C, cymene, A þ B). 31P NMR
(162 MHz, CD2Cl2): δ (ppm) 73.87 (A), 73.20 (B). Anal. Calcd
(%) for C28H45Cl4PRu2: C 44.45, H 6.00. Found: C 44.43, H
5.97. Single crystals were obtained from a saturated dioxane
solution.
[P(CH2OH)Cy3]Cl (4). After separation of complex 3, the
solvent of the filtrate was evaporated and the resulting solid was
dissolved in toluene (10 mL) with heating. On cooling to room
temperature, a white microcrystalline solid precipitated, which
was isolated by filtration, washed with pentane, and dried under
vacuum (yield: 100 mg, 70%). 1H NMR (400 MHz, CD2Cl2): δ
(ppm) 1.34-2.48 (m, 33 H, PCy3), 4.54 (s, 2 H, CH2OH), 7.58
(s, 1 H, CH2OH). 31P NMR (162 MHz, CD2Cl2): δ (ppm) 26.94.
Anal. Calcd (%) for C19H36ClOP ꢀ C7H8: C 71.13, H 10.10.
Found: C 70.74, H 10.46.
[(Cymene)Ru(μ-Cl)3RuCl(H2)(PCy3)] (8). Method A: A solu-
tion of complex 1 (500 mg, 816 μmol) and PCy3 (229 mg, 816
μmol) in THF (70 mL) was heated at 60 °C under an atmosphere
of dihydrogen. After 48 h, the mixture was cooled to room
temperature. The product precipitated in the form of an
orange powder, which was filtered and washed with hexane
(yield: 310 mg, 50%). Method B: A suspension of complex
Table 1. Crystallographic Data for Complexes 3 and 4
3
4 0.5 C7H8
[RuHCl(CO)(PCy3)2] (5). A solution of complex 1 (50 mg,
82 μmol) in MeOH (25 mL) was added to a solution of PCy3
(92 mg, 327 μmol) in MeOH (25 mL) under argon, and the
mixture was stirred for 48 at 60 °C. After cooling to room
temperature, the solution was concentrated to ∼10 mL. The
product precipitated in the form of a yellow-brown powder,
which was isolated by filtration, washed with hexane, and dried
under vacuum (yield: 83 mg, 70%). Anal. Calcd (%) for
C37H67ClOP2Ru: C 61.18, H 9.30. Found: C 61.59, H 9.21.
3
empirical formula
molecular weight
C28H48ClPRu
552.15
C22.5H40ClOP
392.97
[g mol-1
cryst size
cryst syst
]
0.26 ꢀ 0.11 ꢀ 0.10
monoclinic
P21/c
9.8265(5)
10.6166(6)
25.9342(14)
90
91.287(4)
90
2704.9(3)
4
1.356
0.20 ꢀ 0.15 ꢀ 0.15
tetragonal
P421/c
15.0494(7)
15.0494(7)
20.1228(15)
90
90
90
4557.5(5)
8
1.145
space group
˚
a [A]
˚
b [A]
˚
c [A]
1
The H and 31P NMR spectra correspond to what has been
R [deg]
β [deg]
γ [deg]
described previously.17,18
[(Cymene)Ru(μ-Cl)3RuCl(CO)(PCy3)] (6). A solution of com-
plex 1 (100 mg, 163 μmol) and PCy3 (46 mg, 164 μmol) in a
mixture of THF (10 mL) and allyl alcohol (1 mL) was heated to
60 °C under argon. After 48 h, the mixture was cooled to room
temperature and concentrated to 2 mL. The addition of hexane
(5 mL) resulted in the formation of an orange precipitate, which
was filtered, washed with hexane, and dried under vacuum
3
˚
volume [A ]
Z
density [g cm-3
temp [K]
absorp
]
140(2)
0.751
140(2)
0.246
coeff [mm-1
θ range [deg]
index ranges
]
3.10 to 25.03
-11 f 11, -12
f 12, -30 f 30
15 813
2.89 to 25.03
-17 f 17, -15 f 16,
-23 f 23
1
(yield: 90 mg, 70%). IR: ν (cm-1) 1957 (CO). H NMR (400
MHz, CD2Cl2): δ (ppm) 1.23-1.33 (m, 9 H, PCy3), 1.37 (d, 3J=7
Hz, 3 H, CH(CH3)2), 1.36 (d, 3J=7 Hz, 3 H, CH(CH3)2), 1.57 -
2.17 (m, 24 H, PCy3), 2.31 (s, 3 H, CH3), 2.95 (sept, 3J = 7 Hz, 1
reflns collected
indep reflns
absorp corr
max. and
26 991
4558 (Rint = 0.0494) 4012 (Rint = 0.1284)
none
3
H, CH(CH3)2), 5.47 (d, J=6 Hz, 1 H, CH, cymene), 5.49 (d,
semiempirical
0.9330 and 0.8201
3J=6 Hz, 1 H, CH, cymene), 5.62 (d, 3J=6 Hz, 1 H, CH, cymene),
3
5.69 (d, J=6 Hz, 1 H, CH, cymene). 13C NMR (101 MHz,
min transmn
data/restraints/params 4558/0/284
4012/42/250
0.883
CD2Cl2): δ (ppm) 18.73 (CH3), 22.11, 22.22 (CH(CH3)2),
26.57-29.04 (PCy3), 31.45 (CH(CH3)2), 35.72 (d, JP,C=24 Hz,
PCy3), 78.52, 78.62, 79.20, 79.70 (CH, cymene), 96.95, 101.49
(C, cymene), 203.93 (d, JP,C=18 Hz, CO). 31P NMR (162 MHz,
CD2Cl2): δ (ppm) 61.12 (s). Anal. Calcd (%) for C29H47Cl4O-
PRu2: C 44.28, H 6.02. Found: C 44.51, H 6.06. Single crystals
were obtained by slow diffusion of pentane into a solution of
complex 6 in CH2Cl2.
goodness-of-fit
on F2
1.122
final R indices
[I > 2σ(I)]
R indices (all data)
R1=0.0485,
wR2=0.1012
R1=0.0626,
wR2=0.1068
1.905/-0.535
R1=0.0598,
wR2=0.0477
R1=0.1385,
wR2=0.0634
0.390/-0.257
largest diff peak/
]
-3
˚
hole [e A

Article
Organometallics, Vol. 28, No. 15, 2009 4525
Table 2. Crystallographic Data for Complexes 6 and 7
Table 3. Crystallographic Data for Complexes 8 and 10
6 CH2Cl2
7 C2H8O2
8 1.5C7H8
10 6THF
3
3
3
3
empirical formula
molecular weight
C30H49Cl6OPRu2
871.50
C32H53Cl4O2PRu2
844.65
empirical formula
molecular weight
C38.5H61Cl4PRu2
898.78
C78H147Cl6P3Ru3
1789.78
[g mol-1
cryst size
cryst syst
]
[g mol-1
cryst size
cryst syst
]
0.20 ꢀ 0.18 ꢀ 0.10
monoclinic
P21/c
10.117(15)
18.24(3)
20.20(2)
90
100.04(10)
90
3672(10)
4
1.576
0.29 ꢀ 0.25 ꢀ 0.19
triclinic
P1
0.19 ꢀ 0.12 ꢀ 0.10
triclinic
P1
0.30 ꢀ 0.22 ꢀ 0.21
monoclinic
P21/n
18.1411(7)
26.1711(13)
18.2851(10)
90
102.078(4)
90
8493.7(7)
4
1.400
space group
˚
space group
˚
a [A]
9.4728(5)
14.6608(9)
14.6925(9)
63.632(6)
76.162(5)
81.792(5)
1773.55(18)
2
a [A]
9.6821(7)
11.6760(10)
19.3627(18)
73.612(8)
83.743(7)
81.386(7)
2071.2(3)
2
˚
b [A]
˚
b [A]
˚
c [A]
˚
c [A]
R [deg]
β [deg]
γ [deg]
R [deg]
β [deg]
γ [deg]
3
3
˚
˚
volume [A ]
volume [A ]
Z
Z
density [g cm-3
temp [K]
absorp coeff
]
1.582
140(2)
1.226
density [g cm-3
temp [K]
absorp coeff
]
1.441
140(2)
1.051
100(2)
1.325
140(2)
0.820
[mm-1
]
[mm-1
]
θ range [deg]
index ranges
3.03 to 25.02
2.64 to 26.02
θ range [deg]
index ranges
2.98 to 25.03
-11 f 11, -13 f 13,
-22 f 23
2.98 to 25.03
-12 f 12, -21 f 21, -11 f 11, -18 f 17,
-24 f 23 -17 f 18
52 633 15 703
6448 (Rint=0.2160)
semiempirical
1.0000 and 0.8846
-20 f 20, -31 f 31,
-21 f 21
50 232
13 584 (Rint=0.0548)
semiempirical
0.9456 and 0.8904
reflns collected
indep reflns
absorp corr
max. and min
transmn
reflns collected
indep reflns
absorp corr
max. and min
transmn
12 265
6928 (Rint=0.0431)
semiempirical
0.792 and 0.588
6405 (Rint=0.0667)
none
data/restraints/params 6448/162/349
1.159
6928/331/453
0.962
data/restraints/
params
goodness-of-
fit on F2
final R indices
6405/85/461
0.914
13 584/40/840
0.876
goodness-of-
fit on F2
final R indices
R1=0.0923,
wR2=0.1936
R1=0.1735,
wR2=0.2398
2.160/-1.739
R1=0.0494,
wR2=0.1194
R1=0.0735,
wR2=0.1265
2.723/-0.977
[I > 2σ(I)]
R indices (all data)
R1=0.0550,
wR2=0.1259
R1=0.0858,
wR2=0.1364
1.486/-1.416
R1=0.0413,
wR2=0.0853
R1=0.0862,
wR2=0.0946
1.144/-0.837
[I > 2σ(I)]
R indices (all data)
largest diff peak/
]
-3
˚
hole [e A
largest diff peak/
]
-3
˚
hole [e A
[(cymene)Ru(μ-Cl)3RuCl(C2H4)(PCy3)] (9) (1.00 g, 1.30 mmol)
in THF (100 mL) was stirred for 3 days under an atmosphere of
dihydrogen. During this time, the dihydrogen atmosphere was
refreshed several times by briefly applying vacuum followed by
addition of dihydrogen. The product precipitated in the form of
an orange powder, which was filtered and washed with hexane
Crystallographic Investigations. The relevant details of the
crystals, data collection, and structure refinement can be found
in Tables 1-3. The diffraction data for 3, 4, 7, 8, and 10 were
collected using Mo KR radiation on a 4-circle kappa goniometer
equipped with an Oxford Diffraction Sapphire/KM4 CCD at
140(2) K, and all data were reduced by Crysalis PRO.32 The data
for complex 6 were collected with a Bruker APEX II CCD at
100(2) K, and the data were reduced by EvalCCD.33 Absorption
correction was applied to all data sets using a semiem-
pirical method.34 All structures were refined using full-matrix
least-squares on F2 with all non-H atoms anisotropically
defined. The hydrogen atoms were placed in calculated positions
using the “riding model” with Uiso=aUeq (where a is 1.5 for
methyl hydrogen atoms and 1.2 for others). Structure refine-
ment and geometrical calculations were carried out on all
structures with SHELXTL.35 Some disorder problems have
been found for every structure having solvent molecules within
the asymmetric unit. Restraints have been applied to obtain
acceptable displacement parameters and/or atomic distances. A
particular disorder has been found in the last stages of refine-
ment of compound 7; it deals with the bonded cyclo-
hexene moiety and, in particular, with the CH2 carbons of the
cycle. It was possible to determine the two different orien-
tations (named A and B) and to treat them anisotropically by
applying some restraints (SADI and SIMU) to the final split
1
(yield: 870 mg, 90%). H NMR (400 MHz, CD2Cl2): δ (ppm)
-11.83 (d, JP,H=12 Hz, 2 H, Ru(H2)), 1.12-2.08 (m, 33 H, PCy3),
1.35 (d, 3J=7 Hz, 6 H, CH(CH3)2), 2.95 (sept, 3J=7 Hz, 1 H, CH
(CH3)2), 5.40 (d, 3J=6 Hz, 1 H, CH, cymene), 5.44 (d, 3J=6 Hz, 1
H, CH, cymene), 5.56 (d, 3J=6 Hz, 1 H, CH, cymene), 5.62 (d,
3J=6 Hz, 1 H, CH, cymene). 13C NMR (101 MHz, CD2Cl2): δ
(ppm) 18.74 (CH3), 22.12, 22.27 (CH(CH3)2), 26.83 - 29.25 (m,
PCy3), 31.37 (CH(CH3)2), 35.42 (d, JP,C=24 Hz, PCy3), 78.51
(br, CH, cymene), 78.89 (CH, cymene), 96.11, 101.45 (C,
cymene). 31P NMR (162 MHz, CD2Cl2): δ (ppm) 67.40 (s).
Anal. Calcd (%) for C28H49Cl4PRu2: C 44.21, H 6.49. Found: C
44.25, H 6.41. Single crystals were obtained from a saturated
toluene solution upon cooling.
[RuCl2(PCy3)]3 (10). A solution of complex 1 (100 mg, 163
μmol) and PCy3 (92 mg, 326 μmol) in THF (5 mL) was heated to
70 °C. After 48 h, the solvent was evaporated under reduced
pressure and the product was extracted with warm pentane.
After elimination of the solvent under reduced pressure, the
product was dissolved in chloroform and purified by column
chromatography (CHCl3, silica). The resulting powder was
finally washed with a small amount of cold pentane (yield: 106
1
mg, 65%). H NMR (400 MHz, CD2Cl2): δ (ppm) 1.64-2.40
(m, 99 H, PCy3). 13C NMR (101 MHz, CD2Cl2): δ (ppm) 27.91
(s, PCy3), 29.17-29.27 (m, PCy3), 31.62 (s, PCy3), 36.72-38.86
(m, PCy3). 31P NMR (162 MHz, CD2Cl2): δ (ppm) 62.97 (s).
Anal. Calcd (%) for C54H99Cl6Ru3P3: C 47.79, H 7.35. Found:
C 47.84, H 7.55. Single crystals were obtained from a saturated
THF solution upon cooling.
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4526 Organometallics, Vol. 28, No. 15, 2009
Solari et al.
model of the cycle. For the complexes
3
and 8, the
Acknowledgment. The work was supported by the
Swiss National Science Foundation and by the EPFL.
hydrogen atoms directly bonded to the metal centers
were located from the difference Fourier map and were
treated as isotropic with Uiso=1.2Ueq (Ru); the H-H distance
Supporting Information Available: X-ray crystallographic file
in CIF format is available free of charge via the Internet at
http://pubs.acs.org.
˚
of complex 8 was restrained to 0.76 A by means of the DFIX
card.