Cationic half-sandwich ruthenium(II) complexes with cyclopentadienyl- phosphine ligands

Article abstract of DOI:10.1016/S0020-1693(02)01502-5

The reaction of [Ru(η³:η³-C ₁₀H₁₆)Cl₂]₂ (1) with the Cp-linked phosphine ligands L_n (C₅H₅-CH ₂CHRPR′₂; R=H, R′=Ph, n=1; R=Ph, R′=Ph, n=2), in a 5:1 mixture of acetonitrile-ethanol and in the presence of Li ₂CO₃ and KPF₆ affords the cationic half-sandwich ruthenium(II) complexes [{η⁵-C₅H ₄-CH₂CHRPR′₂-κP}Ru(CH ₃CN)₂]·[PF₆] (4) and (5). Both complexes have been characterized in the solid state by an X-ray structure analysis. In contrast, the reaction between 1 and L₃ (R=Ph, R′=o-xylyl) affords the cationic sandwich compound [{η ⁵:η⁶-C₅H₄- CH₂CHPhPR′₂}Ru]·[PF₆] (7), in which one arene substituent of the phosphine is η⁶-coordinated to the metal and the phosphorus remains pendant. Treatment of 5 with tertiary phosphines (PR″₃, R″=i-Pr, Ph, Cy) affords a mixture of the diastereomers [L₂Ru(CH₃CN)PR″₃] ⁺. The diastereoselectivity observed depends on the steric bulkiness of the phosphines and on the reaction conditions.

Full text of DOI:10.1016/S0020-1693(02)01502-5

Inorganica Chimica Acta 350 (2003) 435ꢀ441
/
www.elsevier.com/locate/ica
Cationic half-sandwich ruthenium(II) complexes with
cyclopentadienylꢀphosphine ligands
/
Angelino Doppiu, Ulli Englert, Albrecht Salzer *
Institut fur Anorganische Chemie, RWTH Aachen, D 52056 Aachen, Germany
¨
Received 8 July 2002; accepted 17 September 2002
Dedicated to Professor Pierre Braunstein.
Abstract
The reaction of [Ru(h3:h3-C10H16)Cl2]2 (1) with the Cp-linked phosphine ligands Ln (C5H5ꢀ
?
/
CH2CHRPR2; Rꢁ
/
H, R?ꢁ
/
Ph, nꢁ
/
1; Rꢁ
/
Ph, R?ꢁ
/
Ph, nꢁ
/
2), in a 5:1 mixture of acetonitrileꢀ
/
ethanol and in the presence of Li2CO3 and KPF6 affords the cationic
half-sandwich ruthenium(II) complexes [{h5-C5H4ꢀ
/
CH2CHRPR2-kP}Ru(CH3CN)2]×
/
[PF6] (4) and (5). Both complexes have been
Ph, R?ꢁo-xylyl)
[PF6] (7), in which one arene substituent of the
?
characterized in the solid state by an X-ray structure analysis. In contrast, the reaction between 1 and L3 (Rꢁ
/
/
affords the cationic sandwich compound [{h5:h6-C5H4ꢀ
/
CH2CHPhPR2}Ru]×
/
?
6
ƒ
phosphine is h -coordinated to the metal and the phosphorus remains pendant. Treatment of 5 with tertiary phosphines (PR3, Rƒꢁ
/
i-Pr, Ph, Cy) affords a mixture of the diastereomers [L2Ru(CH3CN)PR3]ꢂ. The diastereoselectivity observed depends on the steric
bulkiness of the phosphines and on the reaction conditions.
ƒ
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Ruthenium; Cyclopentadienyl; Phosphane; Optically active metal complexes; Chiral ligands; X-ray crystallography
1. Introduction
phine ligands in organometallic chemistry and homo-
geneous catalysis. cyclopentadienylꢀphosphine
ligand, connected by an appropriate linker, acts as a
6ꢂ2 electron ligand and forms a stable chelate ring with
both early and late transition metals [2]. There was,
however, still a lack of suitable methods to prepare such
ligands by a general and flexible route. We have recently
reported such a route [4,5] by extending the method of
Kauffmann for ring-opening substituted spiro
[2,4]hepta-4,6-dienes [6] to include also optically active
spacers.
A
/
Chelating ligands containing both a cyclopentadienyl
and a heteroatom have received considerable attention
in recent years. A special attraction of these ligand is the
possibility to vary its three structural components
independently, namely the cyclopentadienyl ring, the
spacer and the heteroatom and its substituents. The
heteroatom can be a hard nucleophile such as oxygen
and nitrogen, but also a soft nucleophile such as
phosphorus, arsenic or sulfur. Both classes of bidentate
ligands and their metal complexes have recently been
reviewed [1,2].
/
Half-sandwich complexes of ruthenium have been
employed in homogeneous catalysis with considerable
The increased interest in these ligands is in part due to
their application as so-called ‘constraint-geometry’ cat-
success, especially by Trost for Cꢀ
/
C bond formation [7].
The catalysts employed were compounds such as
CpRu(PPh3)2Cl, CpRu(COD)Cl or [CpRu(CH3CN)3]ꢂ.
. Kirchner has shown that substitution of one CH3CN
ligand in the latter compound to form [CpRu-
(CH3CN)PPh3]ꢂ also gave a very active catalyst for
alysts (CGC) in industrial ZieglerꢀNatta catalysis [3].
/
Among the possible heteroatoms, phosphorus is most
prominent in view of the general importance of phos-
redox isomerization and Cꢀ
Various attempts have been made to link the Cp and
phosphorus moieties in such compounds through a
/
C bond coupling [8,9].
* Corresponding author. Tel.: ꢂ
809-2288.
E-mail address: albrecht.salzer@ac.rwth-aachen.de (A. Salzer).
/
49-241-809-4646; fax: ꢂ49-241-
/
0020-1693/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0020-1693(02)01502-5

436
A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ441
/
spacer [2]. In almost all cases, these complexes contain a
PPh3 ligand, as the synthesis, starting from
RuCl2(PPh3)3, gives no alternate choice. Only in one
case, a bis(acetonitrile) complex could be isolated by
Takahashi in which the linker connects through an ester
group at the cyclopentadienyl ligand [10].
Additionally, chirality introduced into systems in
which phosphorus is coordinated to the metal may
assist in controlling the stereochemistry of reactions at
the metal center, ultimately leading to an increase in
stereoselection in stoichiometric and catalytic reactions.
This may be dependent on the spatial proximity of the
stereogenic center(s) to the metal, the rigidity of the
chelate ring as well as the shape of the chiral ‘pocket’
created by it.
In some cases, the highly selective formation of a new
stereogenic center at ruthenium has been observed with
such ligands [11ꢀ
/
13]. This has prompted us to find a
5
?
new route to prepare (h -CpCH2CHRPR2-kP)Ru-
(CH3CN)2]ꢂ with both chiral and achiral linkers to
compare its reactivity with that of previously prepared
compounds without linker.
Scheme 1.
2. Results and discussion
2.1. Synthesis of the ligands
The synthesis of L1 (C5H5ꢀ
previously reported [14]. The synthesis of the chiral
cyclopentadienylꢀphosphine ligands Ln (C5H5ꢀ
CH2CHPhPR2, R?ꢁPh, nꢁ2; R?ꢁo-xylyl, nꢁ3)
/CH2CH2PPh2) has been
/
/
?
/
/
/
/
starts from optically active vicinal diols [5,6] and is
shown in Scheme 1. Treatment of 1-Phenyl-1,2-ethane-
diol [15] with methanesulfonyl chloride affords the
bismethanesulfonate ester in quantitative yield. Displa-
cement of the methanesulfonate groups by cyclopenta-
diene in presence of excess NaNH2 affords the
spiroannulated diene with inversion of the configuration
at the chiral carbon. The ring opening reaction with
?
Scheme 2.
LiPR2 (R?ꢁPh, o-xylyl) proceeds with complete regios-
/
electivity at the substituted carbon atom of the cyclo-
propane ring, bringing the stereogenic center close to the
phosphorus atom. The lithium salts of the ligands are
then converted by quenching with water to the corre-
sponding dienes, obtained as a mixture of two regioi-
somers.
forming a five-membered ring. Compound 1 has already
been shown to be a useful reagent in organoruthenium
chemistry, since it can effectively be used to provide in
situ sources of Ru2ꢂ ions [16,17]. The 2,7-dimethyloc-
tadienediyl ligand is eliminated by reductive coupling
leading to 1,6-dimethyl-1,5-cyclooctadiene, which was
detected spectroscopically. This accounts both for its
lability and for the formal Ru(IV)/Ru(II) reduction.
There is spectroscopic evidence that in acetonitrile
solution 2 is in equilibrium with the cationic species
2.2. Complexes with L1
The reaction of [Ru(h3:h3-C10H16)Cl2]2 (1) with the
Cp-linked phosphine ligand L1 in a 1:2 ratio in a mixture
of acetonitrile and ethanol at room temperature and in
presence of Li2CO3, afforded the neutral complex [{h5-
[L1Ru(CH3CN)2] [Cl] (4×
/
[Cl]): a freshly prepared sample
of 2 shows one signal in the 31P NMR spectrum at about
64 ppm. Another signal slowly appears at about 69 ppm,
but upon addition of LiCl, it disappears again. Un-
C5H4ꢀ
/
CH2CH2PPh2-kP}Ru(CH3CN)Cl] (2) (Scheme
2). The ligand acts as a heterobidentate chelating ligand

A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ
/441
437
fortunately, 2 is not stable in the solid state to allow a
complete characterization. Therefore, it was converted
into 3 by reaction with triphenylphosphine. This com-
pound has been previously synthesized in 41% yield
from RuCl2(PPh3)3 and L1 [14]. As 3 crystallized in a
different space group than reported before [14], we have
performed an X-ray structure analysis to confirm its
composition. The result is shown in Fig. 1.
The chloride ligand in 2 can easily be scavenged by
metathesis with KPF6 in acetonitrile solution, affording
the cationic bis(acetonitrile) complex 4×
direct synthesis of 4 consists in the reaction of 1 with L1
in an acetonitrileꢀethanol mixture, in the presence of
/[PF6]. A more
/
Li2CO3 and KPF6. The phosphorus atom coordinated
to the metal resonates at low field (69.5 ppm, CD3CN).
The large downfield shift is characteristic for the
formation of a five-membered chelate ring [18]. The
coordinated acetonitrile ligands give rise to a doublet at
2.1 ppm with a long range coupling (5J) with phospho-
rus of 1.2 Hz. Easy replacement of the acetonitrile
ligands with CD3CN is confirmed by means of 1H
NMR, suggesting that they are substitutionally labile.
The mass spectrum shows the molecular ion at m/z 461.
Fig. 2. PLATON view of the complex cation 4 with 50% displacement
ellipsoid probability, H-atoms omitted.
Compound 4×
/
[PF6] has also been characterized in the
solid state by X-ray analysis (Fig. 2).
2.3. Complexes with L2
With the same procedure used to synthesize 4×
/
[PF6],
the chiral cationic ruthenium compound 5 was formed
in 77% yield from 1 and the ligand L2 (Scheme 3). The
phosphorus is here even more deshielded than in 4,
giving rise to a singlet at 88.7 ppm. Due to the
asymmetry of the molecule, the acetonitrile ligands are
no longer equivalent, giving rise to two signals, one at
1.63 ppm and the other at 2.12, both split into a doublet
Scheme 3.
Compound 5×
/
[PF6] has also been characterized in the
due to the coupling with phosphorus (5JHP
Hz, respectively).
ꢁ1.4 and 1.1
/
solid state by X-ray analysis (Fig. 3). There is a
remarkable similarity in the relative conformation of
the three phenyl groups compared with the analogous
Fig. 1. PLATON view of compound 3 with 50% displacement ellipsoid
probability, H-atoms omitted.
Fig. 3. PLATON view of the complex cation 5 with 50% displacement
ellipsoid probability, H-atoms omitted.

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A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ441
/
rhodium complexes prepared by us previously [4,5],
which represents the most stable conformation and is
not caused by crystal packing effects.
In order to determine how the chirality in the linker
can control the induction of metal-centered chirality, we
not surprising, as the high arenophilicity of ruthenium is
well known. Due to the coordination of one xylyl group,
the phosphorus atom now becomes a stereogenic center,
and only one diastereomer is detectable by analysis of
1
the H and 31P spectra. Due to the asymmetry of the
have reacted 5×/[PF6] with tertiary phosphines with
molecule, the four methyl groups (aꢀd, see Scheme 4),
/
different steric properties. The reactions, carried out in
CH2Cl2 solution at room temperature with an equimo-
lar amount of the phosphines, afforded the cationic
resonate at different frequencies. They could be easily
assigned by means of NOE-difference experiments: a
and b are strongly shielded (0.71 and 1.51 ppm,
respectively, CD3CN), probably due to anisotropic
effect of the aromatic ring current of the phenyl
substituents in the linker. In contrast, the methyl groups
of the metal-coordinated xylyl, c and d, are deshielded
(2.91 and 3.26 ppm, respectively), probably due to
anisotropic effects of the metal.
species 6aꢀc in quantitative yield as a mixture of the two
/
diastereomers. It was found that the selectivity depends
on the steric bulkiness of the phosphine with similar
results for P(i-Pr)3 and PPh3 (deꢁ30 and 31%, respec-
/
tively). The de values were derived from the ratio of the
1
two diastereomers measured by H and 31P NMR. A
higher value (deꢁ71%) was observed with the bulky
/
PCy3 ligand. These results are somewhat lower than
those reported by Takahashi [11]. This may possibly be
due to the fact that Takahashi’s ligands exhibit planar
chirality as they are derived from an unsymmetrically
substituted cyclopentadienyl. Another possible explana-
tion could be inferred from the observation that the
ratio between the two diastereomers changes slowly at
room temperature. The reaction is under kinetic control,
that is, the acetonitrile ligand that easily dissociates is
most probably the one close to the phenyl substituents
2.5. Conclusion
In conclusion, we have shown a simple method to
obtain cationic ruthenium(II) compounds with cyclo-
pentadienyl-linked phosphines. In contrast to the Taka-
hashi method [10], our ligands are easily prepared
starting from readily available chiral diols; in addition,
the ligand backbone can be systematically varied. Due
to the lability of the acetonitrile ligands, we anticipate
that they could be active species in catalytic or stoichio-
metric reactions. We are currently investigating their
possible application.
of the linker (as shown by the X-ray analysis, the N1ꢀ
/
Ru bond is longer than the N2ꢀRu bond), but as this is
/
also the most hindered side of the molecule, the
incoming phosphine is not prone to replace it. Indeed,
if the reaction is carried out under thermodynamic
control, in a 20:1 mixture of CH2Cl2ꢀCH3CN under
/
reflux for 24 h, the de observed is much higher (63% for
6b).
3. Experimental
2.4. Complex with L3
All reactions were carried out under nitrogen using
standard Schlenk techniques. Solvents were dried and
deoxygenated by standard methods. NMR spectra were
A different behavior was observed with the ligand L3.
The reaction was carried out under the same experi-
mental conditions used to synthesize 4 and 5, but instead
of the expected complex, the sandwich compound 7 was
formed in quantitative yield (Scheme 4).
The methyl groups of the xylyl substituents shield the
phosphorus atom, preventing, due to their steric hin-
drance, the coordination to the metal. The metal there-
fore binds to one xylyl of the phosphine instead. This is
1
recorded on a Varian Mercury 200 (200 MHz, H; 50
MHz, 13C; 81 MHz, 31P) and a Varian Unity 500 (500
1
MHz, H; 125 MHz, 13C; 202 MHz, 31P) at ambient
temperature. Chemical shifts (d) are given in ppm
relative to the residual solvent signal (1H and 13C) or
to external H3PO4 (31P). IR spectra were recorded on a
Perkinꢀ
/
Elmer FT IR Model 1720ꢃ spectrometer. Mass
/
spectra were obtained with a Finnigan MAT 95 spectro-
meter. Elemental analyses were obtained on a Carlo
Erba Strumentazione element analyzer, Model 1106.
Methanesulfonyl chloride (Fluka), NaNH2, MgSO4
(Merck), Li-n-Bu (2.5 M in hexane, Aldrich), HPPh2,
P(i-Pr)3, PPh3, PCy3 (Strem), Li2CO3, KPF6 (Merck)
and KBF4 (Aldrich) were used as purchased. Alumina
(Merck) was deactivated with water (10%). 1-Phenyl-
1,2-ethanediol [15], HP(o-xylyl)3 [19], 1 [17], L1 [14], L2
[5,6] were prepared by published procedures.
Scheme 4.

A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ
/441
439
3.1. Syntheses
Yield 0.85 g, 77%, m.p.ꢁ
/
147 8C. Compound 5×
/
[BF4]
was prepared according to the same procedure except
that KBF4 instead of KPF6 was used. 1H NMR
3.1.1. Synthesis of 2
A flask was charged with 1 (0.86 g, 1.4 mmol), Li2CO3
(0.52 g, 7 mmol) and a 5:1 mixture of acetonitrileꢀ
(CD2Cl2): d 1.63 (d, JHP
(d, JHP 1.1 Hz, CH3CN, 3H), 2.30ꢀ
2H), 4.09 (m, Cp, 1H), 4.41 (m, Cp, 1H), 4.66 (m, CH,
1H), 5.13 (m, Cp, 1H), 6.48ꢀ7.45 (m, aromatics, 15H).
13C{H} NMR (CD2Cl2): d 1.85, 3.0, 28.4 (d, JCP
8.7
Hz, CH2), 58.5 (s, Cp), 59.9 (d, JCP 24.7 Hz, CH), 65.7
(s, Cp), 80.9 (d, JCP 7.7 Hz, Cp), 88.2 (d, JCP 5.4 Hz,
Cp), 103.1 (d, JCP 3.9 Hz, Cp), 124.3, 126.0, 126.2 (d,
JCP 3.4 Hz), 127.18, 127.19, 127.24, 127.27,
127.32, 127.9 (d, JCP 14.9 Hz), 128.7 (d, JCP 3.6
Hz), 130.2, 130.4 (d, JCP 4.4 Hz), 130.7 (d, JCP 14.1
Hz), 135.1 (d, JCP 18.6 Hz), 135.4 (d, JCP 14.1 Hz).
31P{H} NMR (CD2Cl2): d ꢄ
143.6 (m, PF6, JPF 709
Hz), 88.65 (s, PPh2). FAB mass (m/z): 536 [(M)ꢂ], 495
[(Mꢄ
CH3CN)ꢂ], 454 [(Mꢄ2CH3CN)ꢂ], 145 [(PF6)ꢄ].
IR (Nujol): 2280, 2251, 1601, 1585, 838, 698 cmꢄ1
[a]Dꢁ
22.78 (cꢁ1, CHCl3). Anal. Calc. For
C29H28F6N2P2Ruꢂ1/2(CH3CN): C, 51.32; H, 4.24; N,
4.99. Found: C, 51.38; H, 4.20; N, 4.97%.
ꢁ
/
1.4 Hz, CH3CN, 3H), 2.12
/
ꢁ
/
/2.62 (m, CH2,
ethanol (50 ml). The ligand L1 (0.78 g, 2.8 mmol),
dissolved in acetonitrile (3 ml), was added and the
mixture stirred at room temperature for 16 h. The
yellow solution obtained was filtered over celite and
evaporated to dryness. The solid was dissolved in
acetonitrile and filtered through a short pad of alumina.
After evaporation of the solvent a yellow solid was
obtained (0.83 g, 65%). The compound is not stable in
the solid state nor in the presence of chlorinated
solvents. In acetonitrile solution, it slowly converts to
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
ꢁ
/
ꢁ
/
/
ꢁ
/
ꢁ
/
4×/[Cl].
/
ꢁ
/
3.1.2. Synthesis of 3
/
/
Freshly prepared 2 (0.28 g, 0.61 mmol) was dissolved
in acetonitrile (10 ml). Triphenylphosphine (0.16 g, 0.61
mmol) was added and the solution stirred for 3 h. Then
the solution was concentrated to about 1 ml and diethyl
.
/
ꢂ
/
/
/
ether was added dropwise affording a yellowꢀ
/
orange
2.09 (m,
solid (0.55 g, 81%). 1H NMR (CD2Cl2): d 1.94ꢀ
/
CH2P, 2H), 2.58 (m, Cp, 1H), 2.97 (m, CH2, 1H), 3.12
(m, CH2, 1H), 4.59 (m, Cp, 1H), 4.98 (m, Cp, 1H), 5.06
3.1.5. Synthesis of 6aꢀ
The title compounds were prepared in quantitative
yield following this procedure: 5×[BF4] (0.1 g, 0.16
/
c×
/
[BF4]
(m, Cp, 1H), 6.87ꢀ
aromatics, 2H). 31P{H} NMR (CD2Cl2): d 44.75 (d,
PPh3, JPP 37.1 Hz), 53.6 (d, PPh2, JPP 37.1 Hz).
FAB mass (m/z): 676 [(M)ꢂ], 641 [(MꢄCl)ꢂ], 414
[(Mꢄ PPh3ꢄ
PPh3)ꢂ], 379 [(Mꢄ Cl)ꢂ]. Anal. Calc. for
C37H33ClP2RuꢂCH3CN: C, 65.30; H, 5.07; N, 1.95.
Found: C, 64.90; H, 5.10; N, 1.75%.
/7.40 (m, aromatics, 23H), 7.94 (m,
/
ꢁ
/
ꢁ
/
mmol) was dissolved in CH2Cl2 (10 ml), the phosphine
(0.16 mmol) was added and the solution stirred at room
temperature until all phosphine had reacted. The solu-
tion was concentrated to 1 ml and diethyl ether was
added dropwise, the solid was filtered and collected. The
/
/
/
/
/
1
de was determined by H and 31P NMR.
3.1.3. Synthesis of 4×/[PF6]
Compound 6a×
(CD2Cl2): d (major) 53.3 (d, P(i-Pr)3, JPP
85.1 (d, PPh2, JPP 24.7 Hz); (minor) 52.3 (d, P(i-Pr)3,
JPP 27.1 Hz), 75.7 (d, PPh2, JPP 27.1 Hz). IR
/
[BF4]: deꢁ
/
30%. 31P{H} NMR
24.7 Hz),
A flask was charged with 1 (1.0 g, 1.6 mmol), Li2CO3
(0.60 g, 8 mmol), KPF6 (0.55 g, 3.2 mmol) and a 5:1
ꢁ
/
ꢁ
/
mixture of acetonitrileꢀethanol (80 ml). The ligand L1
/
ꢁ
/
ꢁ
/
(0.89 g, 3.2 mmol), dissolved in acetonitrile (5 ml), was
added and the mixture stirred under reflux for 8 h. The
resulting yellow solution was filtered through a short
pad of alumina. The product was obtained by slow
(Nujol): 2273, 1056, 698 cmꢄ1. Anal. Calc. For
C36H46BF4NP2Ru: C, 58.21; H, 6.26; N, 1.89. Found:
C, 58.57; H, 6.41; N, 1.59%.
Compound 6b×
(CD2Cl2): d (major) 48.9 (d, PPh3, JPP
87.9 (d, PPh2, JPP 27.1 Hz); (minor) 49.7 (d, PPh3,
Jpp 29.7 Hz), 79.8 (d, PPh2, JPP 29.7 Hz). IR
/
[BF4]: deꢁ
/
31% 31P{H} NMR
27.1 Hz),
crystallization at ꢄ
/
35 8C as yellow crystals (1.9 g, 75%),
138 8C. H NMR (CD2Cl2): d 2.08 (d, CH3CN,
1.2 Hz, 6H), 2.1ꢀ2.3 (m, CH2P, 2H), 3.0ꢀ3.2 (m,
CH2Cp, 2H), 4.17 (m, Cp, 2H), 5.19 (m, Cp, 2H), 7.4ꢀ
7.6 (m, aromatics, 10 H). 31P{H} NMR (CD2Cl2): d
144.3 (m, PF6, JPF 710 Hz), 67.0 (s, PPh2). FAB
mass (m/z): 461 [(M)ꢂ], 420 [(MꢄCH3CN)ꢂ], 379
[(Mꢄ
2CH3CN)ꢂ], 145 [(PF6)ꢄ]. Anal. Calc. for
1
ꢁ
/
m.p.ꢁ
/
ꢁ
/
JHP
ꢁ
/
/
/
ꢁ
/
ꢁ
/
/
(Nujol): 2267, 1055, 696 cmꢄ1. Anal. Calc. For
C45H40BF4NP2Ru: C, 63.98; H, 4.78; N, 1.66. Found:
C, 63.58; H, 5.03; N, 1.65%.
ꢄ
/
ꢁ
/
/
Compound 6c×
(CD2Cl2): d (major) 44.8 (d, PCy3, JPP
86.0 (d,PPh2, JPP 24.7 Hz); (minor) 45.2 (d, PCy3,
JPP 24.9 Hz), 76.0 (d, PPh2, JPP 24.9 Hz). IR
/
[BF4]: deꢁ
/
71% 31P{H} NMR
24.7 Hz),
/
ꢁ
/
C23H24F6N2P2Rh: C, 45.49; H, 3.98; F, 18.76. Found:
C, 45.18; H, 4.03; F, 18.92%.
ꢁ
/
ꢁ
/
ꢁ
/
(Nujol): 2272, 1056, 698 cmꢄ1. Anal. Calc. For
C45H58BF4NP2Ru: C, 62.63; H, 6.79; N, 1.62. Found:
C, 62.42; H, 6.54; N, 1.53%.
3.1.4. Synthesis of 5×
The title compound was prepared from 1 and L2
following the procedure as for 4×[PF6] on a 1 g scale.
/[PF6]
/

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A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ441
/
3.1.6. Synthesis of L3
Table 1
Crystal data, data collection parameters, and convergence results for 4
and 5
The ligand was prepared following a procedure
similar to that used to synthesize L2 [2]. (S)-1-phenyl-
spiro-[2,4]hepta-4,6-diene (1.75 g, 10.4 mmol) was added
4
5
dropwise at ꢄ78 8C to a solution of LiP(o-xylyl)2 in
THF, prepared in situ by addition of n-BuLi (4.2 ml of a
2.5 M solution) to a solution of HP(o-xylyl)2 (2.5 g, 10.3
/
Molecular formula
Formula weight
Crystal system
C
23H24F6N2P2Ru C29H28F6N2P2Ru
605.47
monoclinic
P21/c (14)
14.798(3)
7.6680(14)
21.427(3)
91.23(2)
2430.8(7)
4
681.57
orthorhombic
P212121 (19)
10.727(4)
mmol). The solution was stirred for 2 h at ꢄ78 8C and
/
Space group (no)
˚
then it was allowed to reach ambient temperature
overnight. The solvent was evaporated and the oil
obtained was washed several times with hexane. It was
then dissolved in THF, water (10 ml) was added and the
organic phase was separated, dried over MgSO4, filtered
and evaporated. The product was obtained as a pale
yellow air sensitive oil. Yield 3.8 g, 90%. 1H NMR
a (A)
˚
b (A)
13.3307(19)
20.470(3)
˚
c (A)
b (8)
3
U (A )
˚
2927.2(12)
4
1.51
Z
Dcalc (g cmꢄ3
)
1.65
8.21
m (cmꢄ1
)
6.73
27.0
umax (8)
Temperature (K)
26.0
228
(CD2Cl2): d 2.30 (s, CH3, 6H), 2.49 (s, CH3, 6H), 2.4ꢀ
2.6 (m, CH2, 2H), 4.62 (m, CH, 1H), 5.8ꢀ6.3 (m, Cp,
4H), 6.7ꢀ
7.3 (m, aromatics, 11H). 31P{H} NMR
(CD2Cl2): d ꢄ6.36 (s), ꢄ5.93 (s).
/
213
0.71073
/
˚
l (A)
0.71073
Crystal dimensions (mm3)
Absorption correction
Number of reflections
Independent reflections
Number of vars.
0.4ꢃ
empirical C
9863
/
0.4ꢃ/0.09
0.3ꢃ
/
0.3ꢃ0.05
/
/
/
/
numerical
32 740
6366
4779
309
3.1.7. Synthesis of 7×
The title compound was prepared in quantitative yield
from 1 and L3 following the same procedure used for 4×
/[PF6]
363
a
R
0.0407
0.1030
1.047
0.0350
0.0618
1.057
b
/
wR2
Goodness-of-fit c
1
[PF6]. M.p.ꢁ
/
135ꢀ
/
140 8C. H NMR (CD3CN): d 0.71
ꢄ3
˚
Res el dens (e A
Flack parameter
)
0.81 (close to Ru) 0.37
0.05(2)
(s, CH3, 3H), 1.51 (s, CH3, 3H), 2.40ꢀ/2.80 (m, CH2,
ꢄ/
2H), 2.91 (s, CH3, 3H), 3.26 (s, CH3, 3H), 4.15 (m, Cp,
1H), 4.41 (m, Cp, 1H), 5.10 (m, Cp, 1H), 5.20 (m, Cp,
a
Rꢁ
/
SjjFojꢀ
wR2ꢁ
[S w(Fo2ꢄ
GOFꢁ
[S w(F2o ꢄ
/
jFcjj/SjFoj based on data I ꢀ
Fc2)2/S wFo2]1/2 based on all data.
Fc2)2/(obsꢄvar)]1/2
/2s(I).
7.25 (m, aromatics, 11H). 13C{H} NMR
b
c
1H), 6.50ꢀ
(CD3CN): d 23.5 (d, JCP
JCP 13.4 Hz, CH3), 24.1 (s, CH3), 25.6 (s, CH3), 35.5
(d, JCP 13.4 Hz, CH2), 59.9 (s, Cp), 63.1 (d, JCP 18.2
Hz, CH), 69.6 (s, Cp), 83.7 (d, JCP 7.7 Hz, Cp), 86.2
(d, JCP 4.8 Hz, Cp), 102.4 (s, Cp), 127.8, 128.5, 128.9,
130.1, 130.4 (d, JCP 6.7 Hz), 130.6 (d, JCP 7.7 Hz),
130.8 (d, JCP 7.7 Hz), 130.9 (d, JCP 4.8 Hz), 137.6,
138.4, 139.8 (d, JCP 11.4 Hz), 140.1 (d, JCP 8.7 Hz),
144.1 (d, JCP
17.2 Hz), 145.1. 31P{H} NMR
(CD3CN): d ꢄ143.5 (m, PF6, JPF 694.5 Hz), 61.76
/
/
/
/
/
/
.
ꢁ9.5 Hz, CH3), 23.8 (d,
/
ꢁ
/
ꢁ
/
ꢁ
/
displacement parameters. Hydrogen atoms were treated
as riding in idealized positions. The crystal structure of 3
as an acetonitrile solvate was also determined, but is not
documented here in detail as the solvent-free structure
had already been communicated by Williams et al. [14].
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
ꢁ
/
/
ꢁ
/
(s, PAr2). Anal. Calc. For C25H21F6P2Ru: C, 50.18; H,
3.53; F, 19.05. Found: C, 50.27; H, 3.58; F, 19.21%.
4. Supplementary material
Further details on the structure determinations are
available from the Cambridge Crystallographic Data
Center, CCDC Nos.188173 (for 3), 188174 (for 4) and
188175 (for 5) Copies of this information may be
obtained free of charge from The Director, CCDC, 12
3.2. Crystal structure determination
X-ray structure determinations of 3, 4×
[PF6]: geometry and intensity data were collected with
Mo Ka radiation on an EnrafꢀNonius CAD4 diffract-
/
[PF6] and 5×
/
/
Union Road, Cambridge, CB2 1EZ, UK (fax: ꢂ44-
/
ometer equipped with a graphite monochromator. A
summary of crystal data, data collection parameters and
convergence results is compiled in Table 1. An empirical
absorption correction based on azimuthal scans [20] was
performed in the case of 4 whereas the platelet-like
crystal of 5 was face-indexed and absorption correction
was made by Gaussian integration [21]. The structures
were solved by direct methods [22] and refined on
intensities [23]. In the full-matrix least-squares refine-
ment, all non-hydrogen atoms were assigned anisotropic
1223-336-033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
Acknowledgements
The authors gratefully acknowledge financial support
by the Deutsche Forschungsgemeinschaft DFG within
the Collaborative Research Centre (SFB 380) ‘Asym-

A. Doppiu et al. / Inorganica Chimica Acta 350 (2003) 435ꢀ
/441
441
[10] N. Dodo, Y. Matshushima, M. Uno, K. Onitsuka, S. Takahashi,
J. Chem. Soc., Dalton Trans. (2000) 35.
metric Syntheses with Chemical and Biological Means’
and by the ‘Fonds der Chemischen Industrie’.
[11] K. Onitsuka, N. Dodo, Y. Matsushima, S. Takahashi, Chem.
Commun. (2001) 521.
[12] Y. Nishibayashi, I. Takei, M. Hidai, Organometallics 16 (1997)
3091.
References
[13] C. Kaulen, C. Pala, C. Hu, C. Ganter, Organometallics 20 (2001)
1614.
[1] U. Siemeling, Chem. Rev. 100 (2000) 1495.
[2] H. Butenschon, Chem. Rev. 100 (2000) 1527.
[14] A.M.Z. Slawin, D.J. Williams, J.A. Ramsden, C. White, J. Chem.
Soc., Dalton Trans. (1988) 2491.
¨
[3] A.L. McKnight, R.M. Waymouth, Chem. Rev. 98 (1998) 2587.
[4] S. Ciruelos, U. Englert, A. Salzer, C. Bolm, A. Maischak,
Organometallics 19 (2000) 2240.
[15] J.M. Brown, B.A. Murrer, J. Chem. Soc., Perkin II (1982) 489.
[16] D.N. Cox, R. Roulet, Inorg. Chem. 29 (1990) 1360.
[17] A. Bauer, U. Englert, S. Geyser, F. Podewils, A. Salzer,
Organometallics 19 (2000) 5471.
[5] S. Ciruelos, A. Doppiu, U. Englert, A. Salzer, J. Organomet.
Chem., 663 (2003) 103.
[18] I. Lee, F. Dahan, A. Maisonnat, R. Poilblanc, Organometallics 13
(1994) 2743.
[6] (a) T. Kauffmann, J. Ennen, H. Lhotak, A. Rensing, F.
Steinsiefer, A. Woltermann, Angew. Chem. 92 (1980) 321;
(b) T. Kauffmann, J. Ennen, H. Lhotak, A. Rensing, F.
Steinsiefer, A. Woltermann, Angew. Chem., Int. Ed. Engl. 19
(1980) 328.
[19] A.L. Casalnuovo, T.V. RajanBabu, T.A. Ayers, T.H. Warren, J.
Am. Chem. Soc. 116 (1994) 9869.
[20] A.C.T. North, D.C. Phillips, F.S. Mathews, Acta Crystallogr., A
24 (1968) 351.
[7] B.M. Trost, F.D. Toste, A.B. Pinkerton, Chem. Rev. 101 (2001)
2067.
[8] C. Slugovc, E. Ruba, R. Schmid, K. Kirchner, K. Mereiter,
[21] P. Coppens, L. Leiserowitz, D. Rabinovich, Acta Crystallogr. 18
(1965) 1035.
[22] G.M. Sheldrick, SHELXS86, Program for Crystal Structure Solu-
¨
Monatsh. Chem. 131 (2000) 1241.
[9] C. Slugovc, E. Ruba, R. Schmid, K. Kirchner, Organometallics 18
(1999) 4230.
tion, University of Gottingen, Gottingen, Germany, 1986.
¨ ¨
[23] G.M. Sheldrick, SHELXL97, Program for Crystal Structure Re-
finement, University of Gottingen, Gottingen, Germany, 1997.
¨
¨
¨