Synthesis of a bimetallic P-N bridged rhodium (I)-ruthenium (II) complex: Application in the hydroformylation reaction

Article abstract of DOI:10.1016/j.jorganchem.2015.09.033

The reaction of [Rh(acac)(PPh₂Py)₂] (acac = acetylacetonate, PPh₂Py = 2-(diphenylphosphino)pyridine) with [Cp?Ru(CH₃CN)₃][OTf] (Cp? = pentamethylcyclopentadienyl, OTf = trifluoromethanesulfonate) provides a cationic bimetallic complex [Cp?Ru(PPh₂Py)₂Rh(acac)][OTf], in which a ruthenium-rhodium coordinate (dative covalent) bond is formed. The structure was ascertained by single crystal X-ray diffraction. The catalytic performances of the bimetallic complex were evaluated in the hydroformylation reaction of 1-octene and compared to those of the in situ formed catalysts and the mononuclear counterparts. The catalysis results point out that the bimetallic complex is fragmenting under hydroformylation conditions, which was confirmed by NMR analysis.

Full text of DOI:10.1016/j.jorganchem.2015.09.033

Journal of Organometallic Chemistry 799-800 (2015) 226e231
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis of a bimetallic PeN bridged rhodium (I)eruthenium (II)
complex: Application in the hydroformylation reaction
Ksenia Kartashova b, Sonia Mallet-Ladeira a b, M. Rosa Axet a
a
,
,
, b, *, 1
a
CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France
Universit ꢀe de Toulouse, UPS, INPT, F-31077 Toulouse Cedex 4, France
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 1 July 2015
Received in revised form
The reaction of [Rh(acac)(PPh Py) ] (acac ¼ acetylacetonate, PPh Py ¼ 2ꢀ(diphenylphosphino)pyridine)
2
2
2
with [Cp*Ru(CH
3
CN)
3
][OTf] (Cp* ¼ pentamethylcyclopentadienyl, OTf ¼ trifluoromethanesulfonate)
2 2
provides a cationic bimetallic complex [Cp*Ru(PPh Py) Rh(acac)][OTf], in which a rutheniumerhodium
25 September 2015
coordinate (dative covalent) bond is formed. The structure was ascertained by single crystal X-ray
diffraction. The catalytic performances of the bimetallic complex were evaluated in the hydroformylation
reaction of 1-octene and compared to those of the in situ formed catalysts and the mononuclear coun-
terparts. The catalysis results point out that the bimetallic complex is fragmenting under hydro-
formylation conditions, which was confirmed by NMR analysis.
Accepted 26 September 2015
Available online xxx
Keywords:
Bimetallic complex
Hydroformylation
Rhodium
©
2015 Elsevier B.V. All rights reserved.
Ruthenium
1
. Introduction
catalysts in the tandem hydroformylation/hydrogenation of ter-
minal olefins was reported by Nozaki [12]. The authors produce
alcohols from alkenes under syngas in high yield (up to 90%) in a
one-pot reaction. Taking into account this results we decided to test
the rhodiumeruthenium bimetallic complex synthesised in the
hydroformylation of 1-octene.
Bimetallic complexes, whether homo-or heterobimetallic, have
attracted considerable interest in recent years because they often
present a different reactivity from that of mononuclear counter-
parts. Several reviews have highlighted the great variety of com-
plexes synthesized and the large number of stoichiometric
reactions for which they have showed different reactivity from
mononuclear complexes [1,2]. However, their use as catalysts is
limited [3]. Today, even if many issues remains still to rationalize in
bimetallic catalysis, it has been clearly shown that the combination
of two metal centres in catalysis can affect the activity, even the
selectivity of the reaction and/or allow easy recovery of the catalyst
2. Results and discussion
Treatment of [Rh(acac)(COD)] (acac
¼
acetylacetonate,
COD ¼ 1,5 cyclooctadiene) with two equivalents of 2-(diphenyl-
phosphino)pyridine (PPh Py) in THF (tetrahydrofuran) at room
2
temperature for 1 h provided the rhodium complex (2) as an orange
[4e9].
1
solid in 83% yield (Scheme 1). The H NMR spectrum recorded in
In this context we decided to explore the reactivity of new
8
THF-d showed the presence of two singlets at 1.36 and at 5.19 ppm
attributed to the acetylacetonate moiety. Furthermore, a series of
bimetallic complex with the aim to establish a relationship be-
tween structure and catalytic properties. We have prepared a new
cationic rhodiumeruthenium complex linked by a P, N ligand. The
most interesting use of bimetallic complexes as catalysts is in
tandem reactions [10,11]. In that direction, the use of a bimetallic
system composed by ruthenium and rhodium complexes as
six multiplets are visible in the range of 7.00e8.23 ppm, and are
31
1
2
assigned to the protons of the PPh Py ligand. The P{ H} NMR
spectrum showed a doublet at 54.74 ppm with a rhodiumephos-
phorus coupling constant of 193.4 Hz. The IR spectrum showed two
ꢀ1
bands at 1572 and 1514 cm typical from the acac moiety.
3 3
Complex 2 reacts with one equivalent of [Cp*Ru(CH CN) ][OTf]
(
Cp* ¼ pentamethylcyclopentadienyl, OTf ¼ trifluoromethan
*
Corresponding author. CNRS, LCC (Laboratoire de Chimie de Coordination), 205
esulfonate) (3) in THF at room temperature for 30 min to give the
rhodiumeruthenium complex (4, Scheme 1). Compound 4 was
obtained in 88% yield as a brown solid. The H NMR spectrum
route de Narbonne, BP 44099, F-31077 Toulouse Cedex 4, France.
E-mail address: rosa.axet@lcc-toulouse.fr (M.R. Axet).
www.lcc-toulouse.fr.
1
1
http://dx.doi.org/10.1016/j.jorganchem.2015.09.033
0
022-328X/© 2015 Elsevier B.V. All rights reserved.

K. Kartashova et al. / Journal of Organometallic Chemistry 799-800 (2015) 226e231
227
Scheme 1. Synthesis of bimetallic complex 4.
ꢁ
recorded in THF-d
8
showed two singlets at 1.83 and 5.70 ppm
at 80 C for iPrOH, however producing high quantity of acetal as by-
ꢁ
corresponding to the acetylacetonate ligand. Both signals are
downfield shifted with respect to those of complex 2. A singlet
attributed to the methyl groups of the Cp* moiety appeared at
product, and at 120 C for THF. The low l/b ratio obtained in all cases
(l/b z 3) clearly indicates that the ruthenium organometallic ligand
is not anymore acting as such [15,16] pointing out the fragmenta-
tion of the bimetallic complex.
1.20 ppm. A set of multiplets are visible in the range of
6
.95e7.72 ppm attributed to the protons of the phosphine ligand.
To shed light on that point and on the catalytic species operating
Moreover, a doublet appeared at 9.70 ppm with a coupling constant
of 5.4 Hz, attributed to the proton in alpha position with respect to
the nitrogen atom of the pyridine moiety. We note that this doublet
is approximately downfield shifted by 1.5 ppm relative to same
signal of complex 2. This change of the chemical shift indicates the
in the reaction we carried out an NMR experiment under CO/H
pressure. A solution of bimetallic complex 4 in THF-d was placed
on a quick pressure valve NMR tube. The tube was pressurized with
2
8
ꢁ
5 bar of a mixture of CO/H
2
(1/1) and heated at 60 C for 15 min and
ꢁ
31
1
3 h. After 15 min heating at 60 C the P{ H} NMR spectrum was
recorded at room temperature. The spectrum revealed the disap-
pearance of the doublet at 41.92 (JRh-P ¼ 167.5 Hz) corresponding to
31
coordination of the pyridine group to the ruthenium atom. The
P
1
{
H} NMR spectrum showed a doublet at 41.92 ppm with a rho-
diumephosphorus coupling constant of 167.5 Hz. In addition, the IR
ꢀ
1
spectrum showed two bands at 1574 and 1518 cm attributed to
ꢀ1
the presence of the acac moiety, one band at 1031 cm attributed
ꢀ
1
to the presence of the Cp* and finally a strong band at 1264 cm
characteristic of the triflate counterion.
Single crystals of 4 suitable for X-ray diffraction were obtained
by slow diffusion of pentane into a solution of the complex in THF
(Fig. 1). The structure confirmed the formation of the binuclear
complex 4 and revealed the presence of a rutheniumerhodium
bond of 2.901(1) Ǻ [13,14]. Loss of the three coordinated acetonitrile
ligands from the ruthenium atom results in a coordinative unsa-
turation which is alleviated by formation of a coordinate (dative
covalent) rutheniumerhodium bond. Taking into account the
metals oxidation states (Rh(I) and Ru(II)) a dative Rh / Ru bond is
needed to give to the ruthenium atom its preferred 18e- configu-
ration. The rhodium atom presents a slightly distorted square
planar geometry (without taking into account the RheRu bond,
ꢁ
ꢁ
PeRheO ¼ 178.69(8) and 169.86(8) ). The rhodium is coordinated
to the acac ligand and to two phosphorus atoms. The ruthenium (II)
atom shows a typical three legged piano-stool geometry with the
ruthenium atom being coordinated by two nitrogen atoms of the
2
pyridine moiety of the PPh Py ligand and one coordination site
occupied by the rhodium atom. Crystal data and refinement pa-
rameters are given in Table 1.
The catalytic activity of this novel bimetallic rutheniumerho-
dium complex was tested in the hydroformylation reaction of 1-
octene (Scheme 2), the results are summarized in Table 2.
In general, all the conditions tested attained high conversions of
Fig. 1. Structure model of bimetallic complex 4. Thermal ellipsoids are drawn at the
50% probability level. Counterion, solvates and hydrogen atoms have been omitted for
the sake of clarity. Selected bond lengths (Å) and angles (deg): Ru1eRh1 ¼ 2.901(1);
Ru1eN1 ¼ 2.166(3); Ru1eN2 ¼ 2.190(3); Rh1eP1 ¼ 2.207(1); Rh1eP2 ¼ 2.211(1);
1
-octene in 3 h. However, isomerisation was high (up to 9%) and
alkane formation was observed (up to 14%). Higher conversions
were observed in THF and iPrOH than in toluene. In both solvents
some aldehyde hydrogenation was obtained (up to 4% of alcohol):
Rh1eO1
P2eRh1eO1
N2eRu1eN1 ¼ 91.55(12).
¼
2.060(3); Rh1eO2
¼
2.073(2); P1eRh1eO2
¼
178.69(8);
87.09(9);
¼
169.86(8); N1eRu1eRh1
¼
87.70(9); N2eRu1eRh1
¼

228
K. Kartashova et al. / Journal of Organometallic Chemistry 799-800 (2015) 226e231
1
Table 1
decomposition. In the H NMR spectrum we noted the absence of
the characteristic signal at 9.70 ppm indicating that the pyridine
group is not coordinated to the ruthenium atom. Furthermore, a
Selected crystallographic and refinement parameters.
4
C
singlet attributed at [Cp*HRu(CO)
acac signals were observed at 5.59 and 3.62 ppm indicating the
release of the acac ligand. The P{ H} NMR and the H NMR spectra
were recorded after heating at 60 C for 3 h. The species observed
were the same than observed after 15 min; however, ligand
decomposition was more pronounced.
The NMR analysis confirmed the fragmentation of the bimetallic
complex 4 under CO/H atmosphere and pointed out that several
2
rhodium and ruthenium species are responsibly of the catalytic
activity. To better understand the role of all the catalytic species we
compared the catalytic results of the bimetallic complex 4 to those
of the in situ formed catalysts and to the mononuclear counterparts
Table 3). The comparison of the catalytic tests with bimetallic
complex 4 in the presence or absence of excess of PPh Py ligand
(Table 2, entries 3 and 4 vs. 5 and 6) already reveals that the
addition of ligand prevents the isomerization and hydrogenation of
the olefin. Indeed, the presence of phosphine free ruthenium
2
] appeared at ꢀ10.56 ppm. Free
Empirical formula
Formula weight
Crystal system
Space group
T (K)
a (Å)
b (Å)
c (Å)
49 50 2 2 2 3 3
H N O P RhRu,CF O S
1113.91
Triclinic
P 1
31
1
1
ꢁ
180(2)
11.1084(3)
14.4760(6)
14.5467(6)
93.971(3)
92.371(3)
90.142(3)
2331.54(15)
2
1.587
0.853
1132
ꢁ
a
b
g
( )
ꢁ
( )
ꢁ
( )
3
V (Å )
Z
3
Density (g/cm )
Absorption coefficient (mmꢀ1)
F (000)
(
3
2
Crystal size (mm )
0.22 ꢂ 0.2 ꢂ 0.16
3.23e25.35
33384/8479
0.0639
ꢁ
q
range for data collection ( )
reflections collected/unique
Rint
ꢁ
Completeness to theta ¼ 25,35
99.4%
complex [Cp*HRu(CO)
2
] and phosphine free or with low number of
Py) (CO)nꢀ2]
Max. and min. transmission
1.0 and 0.9230
8479/0/593
1.035
0.0399
0.0795
0.0630
0.0885
0.705 and ꢀ0.629
coordinated phosphine rhodium species [HRh(PPh
may explain the high isomerisation [18] and hydrogenation,
respectively [19].
2
n
Data/restraints/parameters
Goodness-of-fit on F2
R1 [I > 2
s
s
(I)]
2
wR [I > 2
(I)]
The role of ruthenium species as isomerisation catalysts was
confirmed by using [Cp*Ru(CH CN) ][OTf] as catalysts (Table 3,
3 3
entries 11 and 12). The catalytic test reveals that the naked ruthe-
nium complex provides high isomerisation rates, which can be
R1 [all data]
2
wR [all data]
Largest diff. peak and hole (eÅꢀ3)
almost completely suppressed by addition of the PPh
2
Py ligand
(Table 3, entries 13 and 14). Rhodium complex probed to be able to
isomerise and hydrogenate the olefin (Table 3, entries 1 and 2).
The bimetallic system formed in situ was also used as catalysts.
In that case, we added one or two equivalents of ruthenium com-
plex with respect to the rhodium complex. In general, the hydro-
formylation reaction takes place in a similar way than observed for
bimetallic complex 4 and just low amounts of alcohol (up to 6% in
iPrOH) were obtained. The comparison of the entries 3 and 4 vs. 5
and 6 on Table 3 indicates again the importance of the large excess
of ligand in order to prevent side reactions. The run performed with
excess of ruthenium complex (Table 3, entries 5 and 6) show higher
rates of isomerisation and hydrogenation due to the less quantity of
ligand available in the solution for both metals. However, when
Scheme 2. Hydroformylation reaction.
bimetallic complex 4 to produce several phosphorus containing
species (Fig. 2). A new doublet at 28.60 ppm with a coupling con-
stant of 158.4 Hz was attributed to a intermediate rhodium acac
species with coordinated CO. A broad signal at 27.26 ppm is
attributed to a mixture of mono- and bimetallic species of general
formula [HRh(PPh
ordinated to the pyridine moiety. In addition the peak
Py co-
2 n
Py) (CO)nꢀ2] where ruthenium may be still co-
toluene was used instead of THF the side reactions were reduced
6
(
Table 3, entries 7 and 8), suggesting the formation of a
ruthenium complex, [Cp*Ru(C )][OTf], as [Cp*Ru(CH
has proven to be an efficient organometallic precursor for the
h
-arene
][OTf]
at ꢀ13.32 ppm reveals that some species contain the PPh
2
7
H
8
3
CN)
3
ordinated as a bidentate ligand [17]. The peak of the free ligand was
observed at ꢀ1.76 ppm. Two singlets at 47.38 and 51.54 ppm are
6
preparation of a wide range of (
h -arene) p compounds by sub-
attributed to the presence of ruthenium complexes [Cp*Ru(PPh
2-
stitution of the labile acetonitrile ligands [20e25]. The formation of
2 2 2
Py) (CO)][OTf] and [Cp*Ru(PPh Py)(CO) ][OTf]. Other singlets are
visible in the range of 13.51e18.21 ppm probably due to the ligand
6
this
h -arene ruthenium complex increases the aldehyde
Table 2
Hydroformylation reaction of 1-octene using complex 4 as catalyst.
ꢁ
Entry
Solvent
toluene
P [bar] (CO/H
2
)
T [ C]
80
T [h]
Conversion [%]
Aldehyde [%](l/b)
Alcohol [%]
Isomers [%]
n-octane [%]
1
2
3
4
20 (1/4)
3
22
3
22
3
22
3
22
3
86
87
94
96
99
99
98
98
90
94
61(3.0)
62 (2.9)
73 (2.9)
74 (2.9)
99 (3.2)
99 (3.1)
83 (2.9)
79 (2.8)
18 (1.4)
22 (1.5)
0
0
0
1
0
0
2
4
2
4
9
6
6
5
1
1
5
4
7
6
10
14
8
9
0
0
6
7
10
11
THF
20 (1/4)
20 (1/4)
20 (1/4)
20 (1/4)
80
80
5
6
7
8
9
1
*
*
THF
THF
120
80
**
0**
iPrOH
22
Reaction conditions: RueRh complex (0.015 mmol), 1-octene (3 mmol), solvent (15 mL), stirring rate ¼ 1000 rpm. [b] Yields were determined by GC analysis using decane
1.5 mmol) as an internal standard * þ 4 equivalents (0.06 mmol) of PPh Py ** 52% l/b ¼ 6.2 (3 h) 48% l/b ¼ 6.3 (22 h) acetal.
(
2

K. Kartashova et al. / Journal of Organometallic Chemistry 799-800 (2015) 226e231
229
Fig. 2. 31P{1H} NMR spectrum of the bimetallic complex 4 under hydroformylation conditions (15 min at 60 ꢁC and 5 bar of syngas) in THF-d
.
8
selectivity, in one hand by blocking the [Cp*Ru(CH
merisation activity and in another hand allowing more ligand to
coordinate to the rhodium metal.
3
CN)
3
][OTf] iso-
isomerisation/hydrogenation obtained.
3. Experimental
In conclusion, a new bimetallic rhodiumeruthenium complex
has been prepared. This cationic complex shows a coordinate co-
valent RheRu bond of 2.901(1) Ǻ. This new complex has been used
as catalysts in the hydroformylation reaction of 1-octene and the
catalytic performances have been compared to those of the
mononuclear counterparts and to the in situ formed bimetallic
complex. The NMR experiments together with the catalytic test
indicate that the rhodiumeruthenium complex is not stable under
syngas pressure giving several rhodium and ruthenium mono-
metallic species. This fact explains 1) the similar results obtained in
3.1. General methods
All reactions were carried out under argon atmosphere using
standard Schlenk techniques or in a MBraun glovebox. Solvents
were purified by standard methods or by a MBraun SPS-800 solvent
purification system. [Cp*Ru(CH CN) ][OTf] [21] (Cp* ¼ pentamet-
3
3
hylcyclopentadienyl, OTf
¼
trifluoromethanesul-fonate) and
[Rh(acac)(COD)] [26] (acac ¼ acetylacetonate, COD ¼ 1,5 cyclo-
octadiene) were prepared by methods described previously. All
1
13
31
1
-octene hydroformylation using bimetallic complex and mono-
other reagents were used as received. H, C and P NMR spectra
were recorded on a Bruker Avance 400 MHz or Bruker Avance
metallic species, 2) the low l/b ratio and 3) the high amounts of
Table 3
Hydroformylation reaction of 1-octene using complexes 2 and 3 as catalysts.
ꢁ
Entry
catalyst
Solvent
P [bar] (CO/H
2
)
T [ C]
Time [h]
Conv. [%]
Aldehyde [%] (l/b)
Alcohol
%]
Isomers [%]
n-octane [%]
[
1
2
3
4
5
6
7
8
Rh þ 2 L
Rh þ Ru
Rh þ 2 Ru
Rh þ 2 Ru
Rh þ 2 Ru
Ru
THF
20 (1/4)
20 (1/4)
20 (1/4)
20 (1/4)
20 (1/4)
20 (1/4)
20 (1/4)
80
80
80
80
80
80
80
3
22
3
22
3
22
3
22
3
22
3
22
3
98
99
99
99
86
95
97
99
91
96
12
35
3
85 (3.0)
86 (2.9)
99 (2.8)
99 (2.8)
49 (2.7)
63 (2.9)
84 (3.0)
83 (3.0)
13 (1.3)
14 (1.2)
37 (3.7)
20 (3.4)
>99 (2.8)
95 (3.1)
0
0
0
0
0
2
0
0
2
6
0
0
0
0
3
2
1
1
13
5
4
4
9
7
4
3
0
THF
0
THF
20
12
4
toluene
iPrOH
THF
4
9
1
1
1
1
1
*
12
13
0
0
0
0*
1
2
3
4
62
80
0
Ru þ 2 L
THF
22
46
5
0
Reaction conditions: Rh complex (0.015 mmol), Ru complex (0.015 or 0.03 mmol), 1-octene (3 mmol), solvent (15 mL), stirring rate ¼ 1000 rpm. [b] Yields were determined by
GC analysis using decane (1.5 mmol) as an internal standard* 50% l/b ¼ 5.9 (3 h) 50% (22 h) l/b ¼ 5.4 acetal.

230
K. Kartashova et al. / Journal of Organometallic Chemistry 799-800 (2015) 226e231
1
3
00 MHz spectrometer. Chemical shifts are relative to SiMe
4
( H
arene), 102.18 (Cq Cp*), 77.04 (CH acac), 27.89 (CH
3
acac), 10.42 (CH
(ppm) ¼ 41.92 (d, JRh-
):
(ppm) ¼ ꢀ78.84 (s).
¼ 1574, 1518, 1436, 1396, 1264, 1151, 1031, 693, 523 cm
3
13
31
1
and C) using chemical shifts of the solvent as a secondary stan-
8
Cp*). P{ H} NMR (161.9 MHz, THF-d ): d
3
1
19
dard or H
3
PO
4
(
P) as external standard. Hydroformylation re-
P
¼ 167.5 Hz). F NMR (376.5 MHz, THF-d
8
d
ꢀ
1
actions were carried out in a handmade Top Industrie stainless steel
autoclave equipped with a mechanical stirrer. Gas chromatographic
analyses were run on a Perkin Elmer Autosystem XL equipped with
a Restek Rtx 5-Amine column (30 m, 0.53 mm, 1 mm). Infra-red
spectra were collected on a Perkin Elmer Spectrum One spec-
IR (neat)
n
.
ꢀ
1
50 3 2 5 2
Anal. calcd. (%) for C50H F N O P RhRuS (1113,93 g.mol ): C,
53.91; H, 4.52; N, 2.51; found: C 52.63, H 4.73, N, 2.28.
5. Catalysis
trometer as neat films. IR data are reported as characteristic bands
ꢀ
1
(
cm ). Crystallographic data were collected at 180(2) K on an
Agilent Technologies GEMINI EOS diffractometer using a mono-
chromatic MoK radiation (
¼ 0.71073 Å) and equipped with an
In a typical experiment, the autoclave was purged three times
with CO/H mixture. The solution formed from the corresponding
2
a
l
complex (0.015 mmol), 1-octene (3 mmol) and decane (1.5 mmol)
Oxford Cryosystems cooler device. The structure was solved by
direct methods (SIR92) [27] and refined using the least-squares
method on F2 (SHELXL-97) [28]. All non-H atoms were refined
with anisotropic displacement parameters. The hydrogen atoms
were refined isotropically at calculated positions using a riding
model with their Uiso values constrained to 1.5 Ueq of their pivot
atoms for terminal sp3 carbon atoms and 1.2 times for all other
carbon atoms. Crystal data and refinement parameters are given in
Table 1.
in the corresponding solvent (15 ml) was introduced in the auto-
clave. The autoclave was heated and pressurized to the desired
temperature and pressure, the stirring rate was fixed at 1000 rpm.
After the desired reaction time, the autoclave was cooled to room
temperature and depressurised. The reaction mixture was analysed
by gas chromatography.
Acknowledgements
This work was supported by the CNRS, which we gratefully
acknowledge. We thank the Ministry of Education and Science of
Ukraine for the K. K. grant.
4
. Preparation of complexes
4.1. Synthesis of [Rh(acac)(PPh Py) ]
2 2
Appendix A. Supplementary data
2
00 mg (0.65 mmol) of [Rh(acac)(COD)] were dissolved in 10 ml
of dry THF. An excess of 2-(diphenylphosphino)pyridine (PPh Py,
50 mg, 1.3 mmol) was added at once to the solution. The reaction
2
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.jorganchem.2015.09.033.
3
was then stirred for 1 h, and the solvent was partially removed in
vacuo. The residue was washed with dry pentane (3 ꢂ 20 ml) to
References
remove the excess of ligand and the free cyclooctadiene obtaining
1
an orange solid. Yield 387 mg (83%). H NMR (400 MHz, THF-d
8
):
[1] N. Wheatley, P. Kalck, Structure and reactivity of early-late heterobimetallic
complexes, Chem. Rev. 99 (1999) 3379e3419.
d
(ppm) ¼ 8.23 (d, 2H, J ¼ 7.0 Hz, CH arene), 8.18 (d, 2H, J ¼ 4.29 Hz,
[2] L.H. Gade, Highly polar metal-metal bonds in “early-late” heterodimetallic
CH arene), 7.62 (m, 8H, CH arene), 7.32 (m, 2H, CH arene), 7.07 (m,
complexes, Angew. Chem. Int. Ed. 39 (2000) 2658e2678.
4
6
H, CH arene), 7.00 (m, 10H, CH arene), 5.19 (s, 1H, CH acac), 1.36 (s,
H, CH ):
acac). 13C NMR (100.6 Hz, acetone-d
(ppm) ¼ 184.45 (s,
[3] Metal clusters in chemistry, in: P. Braunstein, L.A. Oro, P.R. Raithby (Eds.),
Nanomaterials and Solid-state Cluster Chemistry, vol. 3, Wiley, 1999.
3
6
d
[4] S. Gautron, N. Lassauque, C. Le Berre, L. Azam, R. Giordano, P. Serp,
CO acac), 149.08 (m, CH arene), 136.84 (Cq arene), 136.62 (Cq arene),
G. Laurenczy, J.C. Daran, C. Duhayon, D. Thiebaut, P. Kalck, Promoting role of
1
36.39 (Cq arene), 135.60 (m, CH arene), 135.25 (d, J ¼ 11.1 Hz, CH
[PtI (CO)]2 in the iridium-catalyzed methanol carbonylation to acetic acid and
2
its interaction with involved iridium species, Organometallics 25 (2006)
arene), 134.87 (m, CH arene), 132.59 (m, CH arene), 129.10 (CH ar-
5
894e5905.
5] S. Bonnet, J.H. van Lenthe, M1.A. Siegler, A.L. Spek, G. van Koten,
R.J.M.K. Gebbink, Bimetallic NCN-pincer ruthenium palladium com-
-RuCp coordination: synthesis, x-ray structures, and catalytic
ene), 127.57 (d, J ¼ 9.6 Hz, CH arene), 127.25 (m, CH arene), 123.30
[
(
CH
CH arene), 99.61 (d, J ¼ 1.8 Hz, CH arene), 67.84 (acac), 26.74 (bs,
h ,h
6
acac). 31P{ H} NMR (161.9 MHz, THF-d
1
):
¼ 1572,1514,1434,1396,1093, 741, 694,
Anal. calcd. (%) for Rh
d
(ppm) ¼ 54.74 (d,
6
plexes with h
3
8
properties, Organometallics 28 (2009) 2325e2333.
J
5
Rh-P ¼ 193.4 Hz). IR (neat)
n
[6] Z. Chen, M. Furutachi, Y. Kato, S. Matsunaga, M. Shibasaki, A stable homo-
dinuclear biscobalt(III)-Schiff base complex for catalytic asymmetric 1,4-
ꢀ
1
52, 524 cm
.
39 35 2 2 2
C H N O P
ꢀ
1
(
728,56 g.mol ): C, 64.29; H, 4.84; N, 3.85; found: C 64.14, H 4.86;
addition reactions of
2009) 2218e2220.
b-keto esters to alkynones, Angew. Chem. Int. Ed. 48
(
N 3.55.
[
[
7] S. Jautze, R. Peters, Enantioselective bimetallic catalysis of Michael additions
forming quaternary stereocenters, Angew. Chem. Int. Ed. 47 (2008)
9284e9288.
8] T. Belser, E.N. Jacobsen, Cooperative catalysis in the hydrolytic kinetic reso-
lution of epoxides by chiral [(salen)Co(III)] complexes immobilized on gold
colloids, Adv. Synth. Catal. 350 (2008) 967e971.
2 2
4.2. Synthesis of [Cp*Ru(PPh Py) Rh(acac)][OTf]
100 mg (0.14 mmol) [Rh(acac)(PPh
2
2
Py) ] were dissolved in dry
THF. One equivalent of [Cp*Ru(CH CN)
was added to the solution. The reaction immediately turned from
orange to dark brown. After stirring 30 min the solvent was
3
3
][OTf] (70 mg, 0.14 mmol)
[9] Y.-Y. Lin, S.-C. Tsai, S.J. Yu, Highly efficient and recyclable Au nanoparticle-
supported palladium(II) interphase catalysts and microwave-assisted alkyne
cyclotrimerization reactions in ionic liquids, J. Org. Chem. 73 (2008)
4920e4928.
partially evaporated. The addition of pentane (3 ꢂ 20 ml) gave a
[10] M.H. Perez-Temprano, J.A. Casares, P. Espinet, Bimetallic catalysis using
transition and group 11 metals: an emerging tool for C-C coupling and other
reactions, Chem. Eur. J. 18 (2012) 1864e1884.
1
brown solid. Yield 139 mg (88%). H NMR (400 MHz, THF-d
8
):
d
(ppm) ¼ 9.70 (d, 2H, J ¼ 5.4 Hz, CH arene), 7.72 (m, 2H, CH arene),
[
11] J.-C. Wasilke, S.J. Obrey, R.T. Baker, G.C. Bazan, Concurrent tandem catalysis,
7
.52 (m, 2H, CH arene), 7.47 (m, 4H, CH arene), 7.35 (m, 2H, CH
Chem. Rev. 105 (2005) 1001e1020.
arene), 7.28 (m, 4H, CH arene), 7.10 (m, 6H, CH arene), 6.95 (m, 6H,
[12] K. Takahashi, M. Yamashita, T. Ichihara, K. Nakano, K. Nozaki, High-yielding
tandem hydroformylation/hydrogenation of a terminal olefin to produce a
linear alcohol using a Rh/Ru dual catalyst system, Angew. Chem. Int. Ed. 49
CH arene), 5.70 (s, 1H, CH acac), 1.83 (s, 6H, CH
3
acac), 1.20 (s, 15H,
CH ):
3
Cp*). 13C NMR (100.6 MHz, THF-d
8
d
(ppm) ¼ 187.08 (s, CO
(2010) 4488e4490.
acac), 158.42 (m, CH arene), 136.77 (CH arene), 136.36 (m, CH ar-
[13] B.D. Rowsell, S.J. Trepanier, R. Lam, R. McDonald, M. Cowie, Methylene-
bridged complexes of rhodium/ruthenium as models for bimetallic Fischer-
Tropsch catalysts: comparisons with the Rh/Os and Ir/Ru analogs, Organo-
metallics 21 (2002) 3228e3237.
ene), 136.13 (m, CH arene), 135.88 (Cq arene), 135.64 (Cq arene),
1
35.40 (Cq arene), 131.15 (d, J ¼ 5.4 Hz, CH arene), 130.17 (m, CH
arene), 129.27 (m, CH arene), 129.02 (CH arene), 128.83 (m, CH
[14] N. Nakagawa, M. Murata, M. Sugimoto, H. Nishihara, Dithiolato-bridged

K. Kartashova et al. / Journal of Organometallic Chemistry 799-800 (2015) 226e231
231
[
MRu
complete metal framework reconstruction, Eur. J. Inorg. Chem. 11 (2006)
129e2131.
2
] (M ¼ Rh, Ir, Ru) triangular 50e- cluster complexes synthesized by
[21] P.J. Fagan, M.D. Ward, J.C. Calabrese, Molecular engineering of solid-state
materials: organometallic building blocks, J. Am. Chem. Soc. 111 (1989)
1698e1719.
2
[
[
15] L.A. Van der Veen, M.D.K. Boele, F.R. Bregman, P.C.J. Kamer, P.W.N.M. Van
Leeuwen, K. Goubitz, J. Fraanje, H. Schenk, C. Bo, Electronic effect on rhodium
diphosphine catalyzed hydroformylation: the bite angle effect reconsidered,
J. Am. Chem. Soc. 120 (1998) 11616e11626.
16] L.A. Van der Veen, P.H. Keeven, G.C. Schoemaker, J.N.H. Reek, P.C.J. Kamer,
P.W.N.M. Van Leeuwen, M. Lutz, A.L. Spek, Origin of the bite angle effect on
rhodium diphosphine catalyzed hydroformylation, Organometallics 19 (2000)
[22] J.M. O'Connor, S.J. Friese, B.L. Rodgers, A.L. Rheingold, L. Zakharov, An h6
-
dienyne transition-metal complex, J. Am. Chem. Soc. 127 (2005) 9346e9347.
[23] D. Vichard, M. Gruselle, H. Amouri, G. Jaouen, Synthesis and characterization
of estradiol and estradienonyl derivatives of pentamethylcyclopent-
adienylruthenium(II), J. Chem. Soc. Chem. Commun. 1 (1991) 46e48.
[24] D. Vichard, M. Gruselle, H. Amouri, G. Jaouen, J. Vaissermann, Intermolecular
hydrogen bonding in organometallic-hormone derivatives. Crystal and mo-
872e883.
lecular structures of
a
-[Cp*Ru(estradiol)][CF
3
SO
3
]
and
a-[Cp*Ru(3-O-
[
[
17] K. Wajda-Hermanowicz, Z. Ciunik, A. Kochel, Syntheses and molecular
structure of some Rh and Ru complexes with the chelating diphenyl(2-
pyridyl)phosphine ligand, Inorg. Chem. 45 (2006) 3369e3377.
(hydroxypropyl)estradiol)][CF
[25] D. Vichard, M. Gruselle, H. Amouri, G. Jaouen, J. Vaissermann, Controlled and
3
SO ], Organometallics 11 (1992) 976e979.
3
þ
selective introduction of a Cp*Ru (Cp* ¼ C
5 5
Me ) fragment to the 17a-sub-
18] E. Cesarotti, A. Fusi, R. Ugo, G.M. Zanderighi, Homogeneous catalysis by
stituent of 17
[26] F. Bonati, G. Wilkinson, Dicarbonyl-
a
-phenylestradiol, Organometallics 11 (1992) 2952e2956.
-diketonato- and related complexes of
transition metal complexes. Part V. Hydroformylation of 1-octene catalyzed
b
5
by [
h
-C
5
H
5
M(CO)
2
]
2
species (M ¼ Fe,Ru), J. Mol. Catal. 4 (1978) 205e216.
rhodium(I), J. Chem. Soc. (1964) 3156e3160.
[27] A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, Completion and
refinement of crystal structures with SIR92, J. Appl. Crystallogr. 26 (1993)
343e350.
[
[
19] Rhodium catalyzed hydroformylation, in: P.W.N.M. Van Leeuwen, C. Claver
Eds.), Catal. Met. Complexes, vol. 22, Kluwer, 2000.
(
20] P.J. Fagan, M.D. Ward, J.V. Caspar, J.C. Calabrese, P.J. Krusic, Synthesis and
unusual properties of a helically twisted multiply metalated rubrene deriva-
tive, J. Am. Chem. Soc. 110 (1988) 2981e2983.
[28] G.M. Sheldrick,
A short history of SHELX, Acta Crystallogr. A64 (2008)
112e122.