Pendant-bridging-chelating-cleavage: A series of bonding modes in ruthenium(II)-BINAPO complexes

Article abstract of DOI:10.1021/om050568m

Reaction of 1,1'-bis(diphenylphosphino)binaphthol (BINAPO, 1) with [RuCl₂(η⁶-arene)]₂ in methanol leads to dinuclear BINAPO-bridged Ru compounds [{RuCl₂(η⁶-p- cymene)}₂-(μ-BINAPO)], 2a, in near quantitative yield. In dichloromethane or acetonitrile, 1 preferably affords mononuclear species in which one of the phosphine centers remains uncoordinated. These complexes can be further stabilized by reaction with BH₃ to afford, for example, [RuCl₂(η⁶-p-cymene)(η¹-BINAPO-BH ₃)], 4a. Upon heating a mixture of 1 and [RuCl₂- (η⁶-p-cymene)]₂ in DMF, P-O bond cleavage occurs to afford [RuCl(η²-PPh₂-BINOL)-(η⁶-p- cymene)], 5a, bearing an anionic PO-chelating ligand. Ligand 1 acts as an intact chelate when reacted with [Ru₂(μ-Cl)₃(η ⁶-p-cymene)₂][PF₆] to yield [RuCl(η⁶-p-cymene)(η²-BINAPO)]-[PF₆], 7. Reaction of 1 with [RuCp(CH₃CN)₃] [PF₆] in acetonitrile or chloroform affords [{RuCp(CH₃CN)₂} ₂(η-BINAPO)][PF₆]₂, 8, and [RuCp(CH ₃CN)(η²-BINAPO)] [PF₆], 9, respectively. The solid-state structures of 1, 2a, 4a, and 7 are reported, that of 2a representing a rare structural example of a molecule with a bridging binaphthyl-type ligand.

Full text of DOI:10.1021/om050568m

4974
Organometallics 2005, 24, 4974-4980
Pendant-Bridging-Chelating-Cleavage: A Series of
Bonding Modes in Ruthenium(II)-BINAPO Complexes
Tilmann J. Geldbach,* Adrian B. Chaplin, Kevin D. Ha¨nni,
Rosario Scopelliti, and Paul J. Dyson*
Institut des Sciences et Inge´nierie Chimiques, Ecole Polytechnique Fe´de´rale de Lausanne
(EPFL), CH-1015 Lausanne, Switzerland
Received July 8, 2005
Reaction of 1,1′-bis(diphenylphosphino)binaphthol (BINAPO, 1) with [RuCl2(η6-arene)]2
in methanol leads to dinuclear BINAPO-bridged Ru compounds [{RuCl2(η6-p-cymene)}2-
(µ-BINAPO)], 2a, in near quantitative yield. In dichloromethane or acetonitrile, 1 preferably
affords mononuclear species in which one of the phosphine centers remains uncoordinated.
These complexes can be further stabilized by reaction with BH3 to afford, for example,
[RuCl2(η6-p-cymene)(η1-BINAPO-BH3)], 4a. Upon heating a mixture of 1 and [RuCl2-
(η6-p-cymene)]2 in DMF, P-O bond cleavage occurs to afford [RuCl(η2-PPh2-BINOL)-
(η6-p-cymene)], 5a, bearing an anionic PO-chelating ligand. Ligand 1 acts as an intact chelate
when reacted with [Ru2(µ-Cl)3(η6-p-cymene)2][PF6] to yield [RuCl(η6-p-cymene)(η2-BINAPO)]-
[PF6], 7. Reaction of 1 with [RuCp(CH3CN)3][PF6] in acetonitrile or chloroform affords
[{RuCp(CH3CN)2}2(µ-BINAPO)][PF6]2, 8, and [RuCp(CH3CN)(η2-BINAPO)][PF6], 9, respec-
tively. The solid-state structures of 1, 2a, 4a, and 7 are reported, that of 2a representing a
rare structural example of a molecule with a bridging binaphthyl-type ligand.
1. Introduction
In recent years a plethora of complexes containing
C2-symmetric bisphosphine ligands have been synthe-
sized and successfully used for a large range of asym-
metric transformations. In particular, ruthenium(II)
complexes with chiral BINAP ligands are excellent
hydrogenation catalysts.1-3 Given this background, it
is interesting to note that only very few metal complexes
containing the related phosphinite BINAPO ligand, 1,
have been reported, namely, of palladium,4,5 rhodium,6,7
and ruthenium.8,9 This is even more surprising, as
enantiopure BINAPO is accessible in a facile manner
from the relatively inexpensive chiral precursor
1,1′-dinaphthol.10
It has been demonstrated that with BINAPO ligands
bearing substituents in the 3,3′-position of the binaph-
thyl backbone, good to excellent ee can be achieved in,
for example, the rhodium-catalyzed hydrogenation of
enamides11 and the ruthenium-catalyzed hydrogenation
of â-keto esters.12 Yet, in both cases the catalysts were
generated in situ and the nature of the active species
was not determined. At present, well-defined ruthenium-
BINAPO complexes are, to the best of our knowledge,
restricted to the cationic [RuXCp(BINAPO-F)]+ com-
plexes prepared by Ku¨ndig and co-workers (bearing
perfluorinated P-phenyl groups), which have been em-
ployed in asymmetric Diels-Alder reactions.8 Herein,
we report on the coordination chemistry of 1 with the
widely used ruthenium complexes [RuCp(CH3CN)3]-
[PF6], [Ru2(µ-Cl)3(η6-p-cymene)2][PF6], and [RuCl2-
(η6-arene)]2, of which the latter has been previously used
for the in situ generation of a ruthenium-BINAPO
hydrogenation catalyst.12
* To whom correspondence should be addressed. E-mail:
paul.dyson@epfl.ch.
(1) Shimizu, H.; Nagasaki, I.; Saito, T. Tetrahedron 2005, 61, 5405.
(b) Crepy, K. V. L.; Imamoto, T. Adv. Synth. Catal. 2003, 345, 79.
(c) Hu, A. G.; Ngo, H. L.; Lin, W. B. Angew. Chem., Int. Ed. 2004, 43,
2501.
(2) Kumobayashi, H. Rec. Trav. Chim. Pays-Bas 1996, 115, 201.
(b) Zhang, X.; Mashima, K.; Koyano, K.; Sayo, N.; Kumobayashi, H.;
Akutagawa, S.; Takaya, H. J. Chem. Soc., Perkin Trans. 1994, 2309.
(c) Miyake, T.; Seido, N.; Kumobayashi, H.; Takaya, H. J. Org. Chem.
1995, 60, 357.
(3) Mashima, K.; Kusano, K.; Ohta, T.; Noyori, R.; Takaya, H.
J. Chem. Soc., Chem. Commun. 1989, 1208. Ohta, T.; Takaya, H.;
Noyori, R. Inorg. Chem. 1988, 27, 566. (b) Noyori, R.; Takaya, H. Acc.
Chem. Res. 1990, 23, 345.
(4) Nishimata, T.; Yamaguchi, K.; Mori, M. Tetrahedron Lett. 1999,
40, 5713.
(5) Clyne, D. S.; Mermet-Bouvier, Y. C.; Nomura, N.; RajanBabu,
T. V. J. Org. Chem. 1999, 64, 7601.
2. Results and Discussion
(6) Gergely, I.; Hegedu¨s, C.; Szo¨llo¨sy, A.; Monsees, A.; Riermeier,
T.; Bakos, J. Tetrahedron Lett. 2003, 44, 9025.
The reaction between the dimeric ruthenium-arene
halide, [RuCl2(η6-p-cymene)]2, and 1 in methanol af-
(7) Grubbs, R. H.; DeVries, R. A. Tetrahedron Lett. 1977, 18, 1879.
(8) Alerza, V.; Bernardinelli, G.; Corminboeuf, C.; Frey, U.; Ku¨ndig,
P. E.; Merbach, A. E.; Saudan, C. M.; Viton, F.; Weber, J. J. Am. Chem.
Soc. 2004, 126, 4843.
(10) Cox, P. J.; Wang, W.; Snieckus, V. Tetrahedron Lett. 1992, 33,
2253.
(11) Zhou, Y.-G.; Zhang, X. Chem. Commun. 2002, 1124.
(12) Zhou, Y.-G.; Tang, W.; Wang, W.-B.; Li, L.; Zhang, X. J. Am.
Chem. Soc. 2002, 124, 4952.
(9) Guo, R.; Chen, X.; Elpelt, C.; Song, D.; Morris, R. H. Org. Lett.
2005, 7, 1757. (b) Guo, R.; Elpelt, C.; Chen, X.; Song, D.; Morris, R. H.
Chem. Commun. 2005, 3050.
10.1021/om050568m CCC: $30.25 © 2005 American Chemical Society
Publication on Web 09/08/2005

Pendant-Bridging-Chelating-Cleavage
Organometallics, Vol. 24, No. 21, 2005 4975
Scheme 1
Scheme 2
Table 1. Selected 13C and 31P NMR Chemical
Shifts of Compounds 2a-5a and 7-9 (CD2Cl2 at 293
K)
2a
106.9 108.9 109.3 109.7 132.8
101.1 98.8 98.7 98.2 100.0
149.9 148.4 148.5 148.2 148.1 150.2 150.1
121.3 121.2 120.6 119.2 124.1 122.6 124.3
122.5 120.9 121.0 121.3 118.5 120.0 121.6
3a
4a
5a
7
8
9
C1
77.7
84.7
C4
C20
C21
C29
C20′
C21′
C29′
P1
complex mixtures, presumably due to abstraction and
subsequent decomposition (see below) of the BINAPO
ligand.
153.3 149.1 151.9 150.0
121.5 123.3 115.2 121.6
119.5 120.4 118.2 120.3
149.1
124.8
120.4
A different product was obtained when a mixture of
[RuCl2(η6-p-cymene)]2 and 2 equiv of 1 was heated at
100 °C in DMF, in accordance with the procedure
described previously by Zhang et al. for the in situ
generation of a hydrogenation catalyst.12 Under such
conditions P-O bond cleavage occurred, resulting in the
mononuclear complex 5a as the predominant species.
Compound 5a is highly soluble in organic solvents, even
dissolving to some extent in diethyl ether. The structure
was unambiguously assigned by NMR spectroscopy,
notably from the absence of any phosphorus coupling
to carbon atoms C20′, C21′, and C29′ (see Scheme 2 for
numbering). This complex is likely to be the precursor
to the catalytically active species in the asymmetric
hydrogenation of â-keto esters. In that an eight-
membered ring is formed, the chiral center is in closer
proximity to the metal, providing a plausible explana-
tion for the observed high ee when alkyl substituents
on the binaphthyl moiety are present.12
The facile loss of a PPh2 fragment from 1 indicates
that this ligand has only limited thermal stability.
Indeed, when a solution of BINAPO was heated in DMF,
two new doublets were observed in the 31P NMR
spectrum at δ ) 34.2 and -24.4 ppm with a coupling
constant of JPP ) 222 Hz. On the basis of these data,
we tentatively suggest a product arising from P-O bond
rupture and subsequent P-P bond formation, as exem-
plified in compound 6. Related compounds have been
synthesized previously, and their NMR data agree well
with that of 6.14
117.8 115.1 114.3 114.1 129.5 146.7 155.9
117.8 114.1 110.2 129.5 146.7 153.7
P2
forded the phosphinite-bridged ruthenium dimer com-
plex 2a in near quantitative yield, as shown in Scheme
1. Irrespective of the stoichiometry, i.e., even in the
presence of 2 equiv of BINAPO, 2a was formed exclu-
sively and no mononuclear product with a chelating
ligand was observed. Neither electronic nor steric factors
of the complexed arene appear to influence the course
of the reaction, exemplified by the reactions with
electron-rich, bulky [RuCl2(η6-dibenzo-18-6-crown)]2 and
electron-poor [RuCl2(η6-ethylbenzoate)]2, respectively,
which readily afford the corresponding dinuclear prod-
ucts 2b and 2c, respectively, in high yield. The solubility
of these dinuclear products is very poor in methanol,
allowing facile isolation and purification. Selected NMR
data for 2a (and other compounds described below) are
listed in Table 1.
When the reaction between [RuCl2(η6-p-cymene)]2 and
2 equiv of 1 was performed in dichloromethane, four
signals are observed in the 31P NMR spectrum corre-
sponding to the uncoordinated ligand (δ ) 110.1 ppm),
complex 2a (δ ) 117.7 ppm), and a new species, 3a, with
two singlets of equal intensity at δ ) 114.1 and
115.5 ppm, matching a ruthenium complex bearing a
pendant bisphosphinite ligand. Similar spectra were
also observed if the reaction was conducted in, for
example, acetonitrile or DMSO. Compound 3a is sur-
prisingly stable with respect to coordination of the free
phosphinite to a metal center, although to obtain the
complex in an analytically pure form and to prevent
oxidation of the pendant phosphinite moiety, 3a was
reacted with BH3‚THF to afford the borane adduct 4a
(Scheme 2). This is a common method for protecting
valuable (usually chiral) phosphines from oxidation,
during either storage or synthetic transformations.13
Regeneration of the free phosphine is typically ac-
complished by, for example, addition of an amine base.
Attempts to introduce an additional donor ligand such
as triphenylphosphine to either 2 or 4 resulted in
To prepare a ruthenium-arene complex where 1 acts
as
a
chelating ligand, viz., [RuCl(η6-p-cymene)-
(η2-BINAPO)]+, it was necessary to use an activated
(13) Recent reviews on the chemistry of amine- and phosphine-
borane adducts: (a) Brunel, J. M.; Faure, B.; Maffei, M. Coord. Chem.
Rev. 1998, 178-180, 665. (b) Carboni, B.; Monnier, L. Tetrahedron
1999, 55, 1197.
(14) Schmutzler, R.; Stelzer, O.; Weferling, N. Chem. Ber. 1988, 121,
391.

4976 Organometallics, Vol. 24, No. 21, 2005
Geldbach et al.
Figure 1. Variable-temperature 31P NMR spectra of
complex 7 between 203 and 303 K (CD2Cl2, 162 MHz).
Scheme 3
Figure 2. Section of the C,H long-range correlation
spectrum of 7 showing the cross-peaks within the coordi-
3
nated arene moiety arising predominantly from JCH
couplings (CD2Cl2, 400 MHz).
ruthenium arene precursor such as [Ru2(µ-Cl)3(η6-p-
cymene)2][PF6]. This species acts as the source for the
coordinatively unsaturated, cationic synthon “[RuCl(η6-
p-cymene)]+” and readily reacts with 1 to afford complex
7, as shown in Scheme 3. Attempts to synthesize 7
directly from 1 and [RuCl2(η6-p-cymene)]2 in the pres-
ence of [NH4][PF6], Ag[PF6], or comparable chloride-
abstracting agents were less successful, resulting in the
formation of complex mixtures and low conversion
toward the envisaged product, as evidenced by 31P NMR.
With 1.5 equiv of ligand compound 2a is formed as
byproduct, facilitating the isolation of complex 7 from
the reaction mixture by simple extraction with metha-
nol. The 31P NMR spectrum of 7 in CD2Cl2 at room
temperature displays a broad singlet at δ ) 129.5 ppm,
which upon cooling is resolved into an AB quartet with
2JPP ) 67 Hz at 203 K (see Figure 1), corroborating the
proposed coordination mode. Such temperature-depend-
ent characteristics are also known from ruthenium
complexes with other chelating phosphines such as
BINAP.15 The ESI-MS of 7 exhibits a strong molecular
ion peak at [M]+ ) 925, which upon selective fragmen-
tation (MS/MS)16 gives rise to a peak at m/z ) +791
due to loss of the coordinated arene ligand.
Figure 3. ORTEP plot of 1; ellipsoids are drawn at the
40% probability level. The starred atoms are obtained by
the symmetry operation -x, y, -z.
is tending toward η5-coordintaion rather than η6, re-
flecting both a higher electron density at the metal due
to the presence of two donor P atoms and increased
steric bulk, pushing the isopropyl moiety away from the
ruthenium. These effects are, though less pronounced,
also present in the solid-state structure of 7 (vide infra).
Crystals suitable for X-ray diffraction studies could
be obtained of the free ligand 1 as well of those
complexes where BINAPO acts as either bridging (2a),
pendant (4a), or chelating (7) ligand, and representa-
tions of the structures are shown in Figures 3-6. In all
crystals the binaphthyl ligand displays an R-configu-
ration. Selected bond lengths and angles are given in
Table 2, and relevant crystallographic data are listed
in Table 3. Crystals of 2a and 7 were of only poor
quality, resulting in weak scattering and rather large
thermal ellipsoids.
Relative to complexes 2-5, the C1 carbon atom of the
p-cymene ligand in 7 is shifted by more than 20 ppm to
higher frequency, δ ) 132.8 ppm, as is readily estab-
lished via C,H long-range correlation NMR, shown in
Figure 2. These data suggest that in solution the
interaction between C1 and the metal is fairly weak.
Accordingly, the bonding of the arene to the ruthenium
(15) Geldbach, T. J.; Ru¨egger, H.; Pregosin, P. S. Magn. Reson.
Chem. 2003, 41, 703.
(16) Dyson, P. J.; McIndoe, J. S. Inorg. Chima. Acta 2003, 354, 68.

Pendant-Bridging-Chelating-Cleavage
Organometallics, Vol. 24, No. 21, 2005 4977
Figure 4. ORTEP plot of 2a; ellipsoids are drawn at the
40% probability level; hydrogen atoms and solvent THF
have been omitted for clarity. The starred atoms are
obtained by the symmetry operation -x, 2-y, z.
Figure 6. ORTEP plot of the cation of 7; ellipsoids are
drawn at the 40% probability level; hydrogen atoms and
solvent CH2Cl2 have been omitted for clarity.
Scheme 4
Figure 5. ORTEP plot of 4a; ellipsoids are drawn at the
40% probability level; hydrogen atoms (except those of the
BH3) and solvent CHCl3 have been omitted for clarity.
is comparable to other phosphine-BH3 adducts.17 The
dihedral angle between the planes of the naphthyl rings
in 1 is almost perpendicular, 87.75(4)°, and changes only
moderately in complexes 2a and 4a, with values of
82.5(2)° and 89.91(5)°, respectively. However, in 7,
where 1 binds to the ruthenium in a chelating mode, a
considerably smaller dihedral angle of 69.39(8)° is
observed, differing from previously reported RuCp-
(η2-BINAPO-F) complexes, where the angle is close to
90°.8
Structural parameters around the metal center in 2a,
4a, and 7 are of routine nature, exhibiting the typical
“piano-stool” geometry around the ruthenium. Ru-P
distances are found in a range from 2.298(4) to
2.323(2) Å, Ru-Cl distances vary between 2.365(4) and
2.414(1) Å, and these data are in good agreement with
those of related Ru(II) arene complexes.18 Bond lengths
Table 2. Comparison of Selected Bond Lengths (Å)
and Angles (deg) of 1, 2a, 4a, and 7
1
2a
4a
7
Ru1-Cl1
2.365(4)
2.378(4)
2.299(4)
2.413(1)
2.414(1)
2.317(1)
2.390(2)
Ru1-Cl2
Ru1-P1
Ru1-P2
P1-O1
P1-O2
O1-C20
O2-C20′
Cl1-Ru1-Cl2
P1-Ru1-P2
P1-Ru1-Cl1
P2-Ru1-Cl1
Cl2-Ru1-P1
Ru1-P1-O1
Ru1-P2-O2
2.323(2)
2.322(2)
1.639(4)
1.624(5)
1.389(8)
1.383(8)
1.659(2)
1.377(2)
1.633(9)
1.39(1)
87.3(1)
87.6(1)
1.637(3)
1.616(3)
1.403(4)
1.404(5)
86.52(4)
95.65(8)
85.77(7)
82.46(7)
88.94(4)
90.1(1)
114.1(4)
92.58(3)
115.55(9)
121.5(2)
115.0(2)
(17) McQuade, P.; Winter, R. E. K.; Rath, N. P.; Barton, L. Inorg.
Chim. Acta 2005, 358, 1545. (b) McQuade, P.; Rath, N. P.; Barton, L.
Inorg. Chem. 1999, 38, 5468.
(18) Representative examples: (a) Baldwin, R.; Bennet, M. A.;
Hockless, D. C.; Pertici, P.; Verrazzani, A.; Barretta, G. V.; Marchetti,
F.; Salvadori, P. J. Chem. Soc., Dalton Trans. 2002, 4488. (b) Bhalla,
R.; Boxwell, C. J.; Duckett, S. B.; Dyson, P. J.; Humphrey, D. G.; Steed,
J. W.; Suman, P. Organometallics 2002, 21, 924. (c) Hansen, H. D.;
Nelson, J. H. Organometallics 2000, 19, 4740. (d) Arena, C. G.; Drago,
D.; Panzalorto, M.; Giuseppe, B.; Faraone, F. Inorg. Chim. Acta 1999,
292, 84. (e) Hafner, A.; Mu¨hlebach, A.; van der Schaaf, P. A. Angew.
Chem., Int. Ed. Engl. 1997, 36, 2121. (f) Elsegood, M. R.; Tocher, D.
A. Polyhedron 1995, 14, 3147. (g) Bennet, M. A.; Robertson, G. B.;
Smith, A. K. J. Organomet. Chem. 1972, 43, C41.
Coordination of the free ligand to the ruthenium leads
to a moderate contraction of the P-O bond [1.659(2) Å
in 1 versus 1.624(5)-1.640(9) Å], while interaction of
the phosphinite with the Lewis acid BH3 in 4a has a
more profound effect with an observed P(1)-O(1) bond
of 1.616(3) Å. The P(2)-B(1) distance in 4a, 1.894(6) Å,

4978 Organometallics, Vol. 24, No. 21, 2005
Table 3. Crystallographic Data for 1, 2a, 4a, and 7
Geldbach et al.
formula
C
44H32O2P2
C
64H60Cl4O2P2Ru2‚
C
54H49BCl2O2P2Ru‚
C
54H46ClF6O2P3Ru‚
2THF
CHCl3
CH2Cl2
M
T [K]
cryst syst
space group
a [Å]
b [Å]
c [Å]
654.64
140(2)
1411.21
140(2)
orthorhombic
P21212
13.776(2)
21.201(2)
10.796(2)
90.0
90.0
90.0
3153.0(8)
2
1.469
0.749
3.07 e 2θ e 25.02
19 418
5548 [Rint ) 0.1697]
0.860
1094.02
1155.26
140(2)
orthorhombic
P212121
13.4669(15)
14.7201(17)
25.264(2)
90.0
90.0
90.0
5008.2(9)
4
1.532
0.634
2.85 e 2θ e 25.03
30 890
8332 [Rint ) 0.1332]
0.645
140(2)
monoclinic
I2
12.3895(10)
10.1181(6)
13.7513(12)
90.0
90.954(7)
90.0
1723.6(2)
2
1.261
0.164
3.29 e 2θ e 25.02
5151
2715 [Rint ) 0.0239]
0.950
triclinic
P1
9.9885(9)
10.8157(13)
13.5361(10)
99.160(10)
99.000(7)
117.294(9)
1238.3(2)
1
R [deg]
â [deg]
γ [deg]
V [Å3]
Z
density [Mg/m3]
1.467
0.693
3.34 e 2θ e 25.03
7295
6434 [Rint ) 0.0301]
1.001
µ [mm-1
]
2θ range [deg]
no. of reflns collected
independent reflns
GooF on F2
final R1, wR2 [I > 2σ(I)]
Flack x (esd)
0.0314, 0.0669
-0.04(8)
0.0703, 0.1283
0.20(10)
0.0277, 0.0639
-0.02(2)
0.0450, 0.0558
0.01(4)
involving rhodium carbonyl complexes; see Figure 7.
These examples differ in some respect from the com-
pounds described herein in that they deal with phos-
phite (P(OR)3) rather than phosphinite (P(OR)R2) ligands.
In 10, a diphosphite-binaphthyl ligand coordinates to
two rhodium centers in a tetranuclear Rh-carbonyl
cluster,20 whereas in the other example, assigned on the
basis of its IR and 31P NMR spectra, a similar ligand
bridges between two rhodium centers, affording the
dinuclear complex 11.21
In conclusion a series of ruthenium(II) complexes
bearing BINAPO ligands have been prepared, demon-
strating that rather subtle changes in the reaction
conditions can induce very different coordination modes
of the ligand. Relative to other binaphthyl-based bis-
phosphines such as the widely used BINAP, ligand 1 is
less likely to coordinate in a chelating manner and
activated precursors are required to afford complexes
of the type [RuX(η2-BINAPO)(η6-arene)]+. Otherwise
complexes where 1 acts as either bridging or pendant
ligand predominate. These observations may have im-
plications for the use of 1 as ligand in catalysis in that
a change of solvent and/or reaction temperature may
afford markedly different species, thereby potentially
deciding over success or failure of a given transforma-
tion.
Figure 7.
between the metal and the carbon atoms of the coordi-
nated arene are of comparable length in 2a and
4a [2.12(2)-2.255(4) Å] and somewhat longer in 7
[2.219(8)-2.345(8) Å], reflecting both higher electron
density at the metal as well as increased steric bulk in
the latter complex. In 7 the distance between the
ruthenium and C(1), 2.345(8) Å, is relatively long, in
agreement with the solution 13C NMR data, but still
sufficiently short to consider the coordination of the
arene in the solid state as η6. The bite angle of the
bisphosphinite in complex 7 is 95.65(8)°, comparable to
that of bisdiphenylphosphino ferrocene (dppf).19
A diverse coordination chemistry of ligand 1 also
emerges when [RuCp(CH3CN)3][PF6] is employed as
precursor instead of dimeric ruthenium-arene com-
plexes; see Scheme 4. In acetonitrile, the ruthenium
complex reacts with 1 to afford the dicationic complex
8 as the only product, as is evident from a singlet in
the 31P NMR spectrum, δ ) 146.7 ppm, as well as from
ESI-MS, [M]2+ ) 575.3. However, in noncoordinating
solvents such as chloroform, 1 binds preferably in a
chelating mode, affording the cationic complex 9. This
compound is readily identified from the appearance of
two doublets in the 31P NMR at δ ) 155.9 and 153.7
with a coupling constant 2JPP ) 50 Hz, as well as from
the mass of the molecular ion, [M]+ ) 861.7.
3. Experimental Section
General Techniques. All manipulations were performed
under an atmosphere of nitrogen, using standard Schlenk
techniques. Solvents were dried catalytically (Et2O, CH2Cl2),
distilled from calcium hydride (acetonitrile, DMF), or used as
received following saturation with nitrogen (MeOH, chloro-
form). Chromatographic separations where carried out in air
using 1.0 × 20 × 20 mm silica gel 60 F254 plates (Merck).
[RuCl2(η6-p-cymene)]2,22 [RuCl2(η6-dibenzo-18-crown-6)]2,23
[RuCl2(η6-ethylbenzoate)]2,24 [Ru2(µ-Cl)3(η6-p-cymene)2][PF6],25
(20) Moasser, B.; Gladfelter W. L. Inorg. Chim. Acta 1996, 242, 125.
(21) Nifantev, E. E.; Rasadkina, E. N.; Batalova, T. A.; Bekker, A.
R.; Stash, A. I.; Belskii V. K. Zh. Obshch. Khim. 1996, 66, 1109-1114.
(22) Bennett, M. A.; Huang, T. N.; Matheson, T. W.; Smith, A. K.
Inorg. Synth. 1982, 21, 74.
(23) Geldbach, T. J.; Brown, M. R. H.; Scopelliti, R.; Dyson, P. J.
J. Organomet. Chem. 2005, in press.
(24) Therrien, B.; Ward, T. R.; Pilkington, M.; Hoffann, C.; Gilardoni,
F.; Weber, J. Organometallics 1998, 330, 17.
While there are few examples for complexes bearing
1 as ligand, compounds with binaphthyl-based ligands
bridging two metal centers are very rare. We are aware
of only two examples where this is the case, both
(19) Hamann, B. C.; Hartwig, J. F. J. Am. Chem. Soc. 1998, 120,
3694.

Pendant-Bridging-Chelating-Cleavage
Organometallics, Vol. 24, No. 21, 2005 4979
[RuCp(CH3CN)3][PF6],26 and (R)-127 were prepared according
to methods described previously; all other compounds were
commercially available and used as received. NMR spectra
were recorded on a Bruker Avance 400 with chemical shifts
δ given in ppm (internal lock as reference) and coupling
constants J given in Hz as positive values regardless of their
real individual signs. Electrospray ionization mass spectra
(ESI-MS) were recorded on a ThermoFinnigan LCQ Deca XP
Plus quadrupole ion trap instrument, and elementary analyses
were carried out at the EPFL.
C3), 82.8 (C5), 62.5 (C8), 14.2 (C9). 31P NMR (CD2Cl2, 162
MHz): 117.2 (s). Anal. Calcd for C62H52Cl4O6P2Ru2‚2H2O: C,
55.78; H, 4.23. Found: C, 56.07; H, 4.39.
Synthesis of 4a. A solution of [RuCl2(η6-p-cymene)]2
(468 mg, 0.076 mmol) and 1 (100 mg, 0.15 mmol) in CH2Cl2
(10 mL) was stirred at room temperature for 5 min, then cooled
to 0 °C, and a solution of BH3 in THF (∼1.2 M, 0.26 mL,
0.31 mmol) was added. Following stirring a further 30 min at
room temperature, the solution was concentrated to ca. 2 mL
in vacuo and subjected to preparative TLC (1:10 acetone-
CH2Cl2). The product was isolated by extraction of the first
orange band (Rf ) 0.68) with THF. Yield: 66 mg (44%). 1H
Synthesis of 2a. A suspension of [RuCl2(η6-p-cymene)]2
(100 mg, 0.16 mmol) and 1 (110 mg, 0.17 mmol) in methanol
(10 mL) was heated to reflux for 5 min, and then stirring
continued at room temperature for another 30 min, during
which time a salmon-colored precipitate forms. The solvent
was removed by filtration and the residue washed twice with
methanol. Yield: 194 mg (94%). 1H NMR (CD2Cl2, 400 MHz):
3
NMR (CD2Cl2, 400 MHz): 8.16 (d, JHH ) 9.1, 1H, H28′), 8.10
(d, 3JHH ) 8.2, 1H, H26′), 8.00 (d, 3JHH ) 7.9, 1H, H26), 7.98 (d,
3
3JHH ) 9.0, 1H, H29), 7.91 (d, JHH ) 9.0, 1H, H28), 7.76 (d,
3JHH ) 9.0, 1H, H29′), 6.9-7.6 (m, 24H), 6.7-6.8 (m, 2H), 5.19
3
3
(d, JHH ) 5.9, 1H, H6), 5.15 (d, JHH ) 5.8, 1H, H3), 5.12 (d,
3JHH ) 5.9, 1H, H2), 5.03 (d, 3JHH ) 6.0, 1H, H5), 2.17 (septet,
3JHH ) 6.9, 1H, H7), 1.30 (s, 1H, H10), 1.0 (br, 3H, BH3), 0.75
3
3
8.24 (d, JHH ) 7.9, 2H, H26), 8.23 (d, JHH ) 9.1, 2H, H28),
8.04 (d, 3JHH ) 9.1, 2H, H29), 7.76 (m, 6H), 7.61 (dd, 2H, H25),
7.50 (dd, 2H, H24), 7.21 (m, 2H), 7.00 (m, 4H), 6.92 (m, 4H),
3
(d, JHH ) 6.7, 6H, H8,9). 13C NMR (CD2Cl2, 100 MHz): 149.1
6.22 (m, 4H), 5.52 (d, JHH ) 6.7, 2H, H3), 5.37 (br, 2H, H2),
3
(d, 2JPC ) 5, C20′), 148.5 (d, 2JPC ) 5, C20), 133.7 (C22,22′), 132.2
5.00 (br, 2H, H6), 4.75 (d, JHH ) 5.9, 2H, H5), 1.83 (dq, 2H,
3
4
4
(d, JPC ) 2), 132.1 (d, JPC ) 2), 131.5 (br), 131.3(br), 131.2
H7), 1.53 (s, 6H, H10), 0.74 (d, JHH ) 7.0, 6H, H8/9), 0.47 (d,
3
(d, JPC ) 12), 131.1 (d, JPC ) 11), 130.5 (C27′), 130.5 (d, 4JPC
)
3JHH ) 6.7, 6H, H8/9). 13C NMR (CD2Cl2, 100 MHz): 149.9 (d,
2), 130.4 (d, JPC ) 2), 130.0 (C27), 129.6 (C28,28′), 128.9 (d,
JPC ) 11), 128.6 (C26′), 128.4 (d, JPC ) 11), 128.2 (C26), 127.6
(d, JPC ) 10), 127.4 (d, JPC ) 11), 127.3 (C24), 127.1 (C24′), 125.8,
125.6, 125.4, 125.1, 123.3 (d, 3JPC ) 5, C21′), 121.0 (d, 3JPC ) 6,
4
2JPC ) 3, C20), 133.5 (C22), 132.7 (d, JPC ) 11), 130.5 (d, JPC
2
4
) 3), 130.5 (C27), 130.1 (d, 4JPC ) 2), 130.0 (C28), 129.5 (d, 2JPC
) 9), 129.3 (C26), 127.8 (d, JPC ) 11), 127.6 (C24), 127.0 (d,
3
3JPC ) 11), 125.4 (C25), 124.9 (C23), 122.5 (d, JPC ) 6, C29),
3
C29), 120.6 (d, JPC ) 6, C21), 120.4 (d, JPC ) 5, C29′), 109.3
3
3
121.3 (d, JPC ) 6, C21), 106.9 (C1), 101.1 (C4), 92.2 (d, JPC
)
3
2
(C1), 98.7 (C4), 90.4 (br, C3), 89.7 (br, C5), 89.0 (d, JPC ) 5,
2
10, C3), 91.6 (br, C2), 85.5 (br, C5), 85.1 (d, JPC ) 3, C6), 29.8
(C7), 21.6 (C9), 20.7 (C8), 17.4 (C10). 31P NMR (CD2Cl2, 162
MHz): 117.8 (s). Anal. Calcd for C64H60Cl4O2P2Ru2: C, 60.67;
H, 4.77. Found: C, 60.52; H, 5.03.
2
C2), 87.6 (d, JPC ) 4, C6), 29.9 (C7), 21.2 (C8,9), 17.2 (C10).
2
31P NMR (CD2Cl2, 162 MHz): 114.3 (s, RuP), 110.2 (br, PBH3).
11B NMR (CD2Cl2, 128 MHz): -38.8 (br). Anal. Calcd for
C54H49BCl2O2P2Ru‚11/3CH2Cl2: C, 61.09; H, 4.79. Found: C,
61.17; H, 4.49.
Synthesis of 2b. As described for 2a but with [RuCl2-
1
(η6-dibenzo-18-crown-6)]2 as substrate. Yield: 92%. H NMR
Synthesis of 5a. A solution of [RuCl2(η6-p-cymene)]2
(35 mg, 0.06 mmol) and 1 (80 mg, 0.12 mmol) in DMF (6 mL)
was heated to 100 °C for 10 min, then the solvent was removed
in vacuo. The crude product was washed with Et2O-pentane
(1:1, 5 mL) and then extracted with Et2O-methanol (10:1) to
afford the product as an orange-red solid. Yield: 57 mg (68%).
(CD2Cl2, 400 MHz): 8.21 (d, 3JHH ) 8.1, 2H, H26), 8.20 (d, 3JHH
) 9.2, 2H, H28), 8.15 (d, 3JHH ) 9.2, 2H, H29), 7.78 (dd, br, 4H),
3
7.65 (d, JHH ) 8.3, 2H, H23), 7.61 (m, 2H, H25), 7.49 (m, 2H,
H24), 7.21 (m, 2H), 7.03-6.97 (m, 10H), 6.90-6.81 (m, 8H),
6.36 (br, 4H), 5.29 (br, 2H, H2), 4.76 (br, 2H, H3), 4.55 (br, 2H,
H4), 4.32 (br, 2H, H5), 4.24-3.72 (m, 24H), 3.61 (br, 2H), 3.24
(br, 4H), 2.67 (br, 2H). 13C NMR (CD2Cl2, 100 MHz): 149.6 (d,
3
1H NMR (CD2Cl2, 400 MHz): 8.20 (d, JHH ) 8.9, 1H, H28′),
3
3
8.10 (d, JHH ) 7.8, 1H, H26), 8.07 (d, JHH ) 9.1, 1H, H29),
2
2JPC ) 3, C20), 148.6, 148.5, 133.6 (C22), 132.6 (d, JPC ) 11),
3
3
7.93 (d, JHH ) 8.0, 1H, H26), 7.87 (d, JHH ) 9.1, 1H, H28),
4
130.6 (d, JPC ) 3), 130.5 (C27), 130.2 (br), 129.9 (C28), 129.4
3
7.56 (d, JHH ) 8.9, 1H, H29′), 7.54-7.23 (m, 13H), 7.16-7.08
2
3
(d, JPC ) 10), 129.1 (C26), 128.0 (d, JPC ) 11), 127.7 (C24),
(m, 4H), 5.28 (d, JHH ) 5.9, 1H, H2), 5.20 (d, JHH ) 5.9, 1H,
3
3
127.2 (d, 3JPC ) 10), 125.5 (C25), 124.7 (C23), 122.3 (br, C6), 121.9
H6), 5.18 (d, JHH ) 5.9, 1H, H3), 5.15 (d, JHH ) 5.9, 1H, H5),
3
3
3
3
(d, JPC ) 6, C29), 121.2 (d, JPC ) 6, C21), 120.8, 120.7, 112.6,
112.5, 81.7 (br, C3), 76.0 (br, C2), 75.5 (br, C4), 72.3 (br, C5),
70.2, 70.0, 69.8, 69.1, 69.0, 68.9, 67.8, 67.7. 31P NMR (CD2Cl2,
162 MHz): 124.1 (s). Anal. Calcd for C84H80Cl4O14P2Ru2‚
2H2O: C, 57.47; H, 4.82. Found: C, 57.38; H, 4.02.
2.34 (dq, 1H, H7), 1.53 (s, 3H, H10), 0.85 (d, JHH ) 6.9, 3H,
3
H8/9), 0.79 (d, JHH ) 6.9, 3H, H8/9). 13C NMR (CD2Cl2,
3
100 MHz): 151.9 (C20′), 148.2 (d, JPC ) 8, C20), 134.0 (C22),
2
133.8 (C22′), 131.9 (d, 2JPC ) 11), 131.3 (d, 2JPC ) 11), 130.6 (d,
4JPC ) 2), 130.5 (d, 4JPC ) 2), 130.3 (C27), 130.2 (C28,28′), 129.6
3
Synthesis of 2c. As described for 2a but with [RuCl2-
(C27′), 128.5 (C26), 128.4 (C26′), 127.6 (d, JPC ) 11), 127.5 (d,
(η6-ethylbenzoate)]2 as substrate. Yield: 85%. 1H NMR
3JPC ) 11), 127.3 (C24), 127.0 (C24′), 125.1 (C23), 124.9 (C25),
124.5 (C23′), 123.8 (C25′), 121.3 (d, 3JPC ) 6, C29), 119.2 (d, 3JPC
) 5, C21), 118.2 (29′), 115.2 (C21′), 109.7 (C1), 98.2 (C4), 91.3 (d,
2JPC ) 5, C5), 90.9 (d, 2JPC ) 5, C3), 88.0 (d, 2JPC ) 6, C2), 87.8
3
(CD2Cl2, 400 MHz): 8.23 (m, 2H, H26,28), 8.11 (d, JHH ) 9.1,
2H, H29), 7.71 (dd, 4H), 7.66-7.62 (m, 4H, H25,23), 7.49 (dd,
2H, H24), 7.27 (dt, 2H), 7.12-6.97 (m, 10H), 6.50 (m, 4H), 6.45
(d, JHH ) 6.2, 2H, H2), 6.27 (d, JHH ) 5.9, 2H, H6), 5.32 (dd,
(d, JPC ) 6, C6), 30.0 (C7), 21.2 (C8,9), 17.3 (C10). 31P NMR
3
3
2
2H, H4), 5.02 (dd, 2H, H3), 4.60 (dd, 2H, H5), 4.22 (m, 4H, H8),
(CD2Cl2, 162 MHz): 114.1 (s).
1.29 (t, JHH ) 7.1, H9). 13C NMR (CD2Cl2, 100 MHz): 162.9
3
Synthesis of 7. To a solution of [Ru2(µ-Cl)3(η6-p-cymene)2]-
[PF6] (78 mg, 0.107 mmol) in CH2Cl2 (20 mL) was added 1
(105 mg, 0.161 mmol) and the solution stirred at RT for 4 h
before the solvent was removed in vacuo. The residue was
washed with MeOH (2 × 5 mL), leaving an orange solid, and
the washings were subjected to preparative TLC (CH2Cl2)
following concentration. The first (broad) yellow band
(Rf ) 0.27) was extracted with CH2Cl2-MeOH to give the
product as a yellow powder (yield: 14 mg). Further extraction
of the orange solid with MeOH (100 mL) gave additional
product (70 mg, >92% purity by 31P NMR). Total yield: 68%
per Ru2. Analytically pure samples can be obtained (in low
yield) by preparative TLC as described above. 1H NMR
(C7), 149.6 (d, JPC ) 4, C20), 133.5 (C22), 132.6 (d, JPC ) 11),
2
2
131.2 (d, 4JPC ) 3), 130.8 (d, 4JPC ) 2), 130.6 (C27), 130.2 (C28),
130.0 (d, JPC ) 11), 129.2 (C26), 127.9 (d, JPC ) 11), 127.8
2
3
(C24), 127.5 (d, JPC ) 11), 125.7 (C25), 124.9 (C23), 121.7 (d,
3
3JPC ) 6, C29), 121.3 (d, JPC ) 6, C21), 98.6 (C2), 97.3 (d, JPC
3
2
) 3, C6), 89.0 (d, JPC ) 10, C7), 88.6 (C4), 83.6 (d, JPC ) 3,
3
2
(25) Bennett, M. A.; Smith, A. K. J. Chem. Soc., Dalton Trans. 1974,
233.
(26) Trost, B. M.; Older, C. M. Organometallics 2002, 21, 2544-
2546.
(27) Grubbs, R. H.; DeVries, R. A. Tetrahedron Lett. 1977, 22, 1879.
(b) Zhou, Y.-G.; Zhang, X. Chem. Commun. 2002, 1124.

4980 Organometallics, Vol. 24, No. 21, 2005
Geldbach et al.
(CD2Cl2, 400 MHz): 7.98 (br, 2H), 7.90-7.80 (m, 4H), 7.69-
7.53 (m, 9H), 7.47-7.29 (m, 9H), 7.26-7.18 (m, 2H, H24,24′),
(d, JPC ) 10), 128.2 (C26′), 128.0 (C26), 127.9 (d, JPC ) 11), 127.5
(d, JPC ) 14), 127.4 (C24′), 127.3 (C24), 125.8 (C25), 125.6 (C25′),
3
3
3
7.10 (br, 2H), 6.91 (d, JHH ) 8.5, 1H, H23′), 6.82 (d, JHH
)
125.4 (C23), 125.2 (C23′), 124.8 (d, JPC ) 5, C21′), 124.3 (d,
8.5, 1H, H23), 6.40 (d, 3JHH ) 9.4, 1H, H29′), 6.11 (d, 3JHH ) 9.4,
1H, H29), 5.85 (m, 1H, H2), 5.76 (m, 1H, H3), 5.52 (m, 1H, H5),
5.32 (m, 1H, H6), 2.56 (dq, 1H, H7), 1.29 (s, 3H, H10), 1.24 (d,
3JPC ) 4, C21′), 121.6 (d, 3JPC ) 3, C29), 120.4 (d, 3JPC ) 2, C29′),
84.7 (d, 2JPC ) 2, C1), 4.3 (CH3). 31P NMR (CD2Cl2, 162 MHz):
2
2
155.9 (d, JPP ) 50), 153.7 (d, JPP ) 50). ESI-MS (CH2Cl2):
m/z +861.7 [M]+, +821.3 [M - CH3CN]+. Anal. Calcd for
C51H40F6NO2P3Ru: C, 60.84; H, 4.00; N, 1.39. Found: C, 61.06;
H, 4.60; N, 1.81.
3
3JHH ) 7.0, 3H, H8/9), 0.60 (d, JHH ) 6.7, 3H, H8/9). 13C NMR
(CD2Cl2, 100 MHz): 150.0 (br, C20′), 148.1 (br, C20), 134.5 (m),
134.3 (br), 133.7 (C22), 133.6 (br), 133.1 (C22′), 132.8 (C1), 131.8
(br), 131.3 (br), 130.8 (br), 130.6 (C27,27′), 129.4 (br), 129.2 (m),
129.0 (m), 128.7 (m), 128.1 (br), 128.0 (C26), 127.9 (C26′), 127.8
(m), 127.1 (C24), 126.7 (C24′), 125.8 (C23), 125.7 (C25′), 125.3 (C25),
125.2 (C23′), 124.1 (C21), 121.6 (C21′), 120.3 (C29′), 118.5 (C29),
Crystallography. Data collection for the X-ray structure
determinations were performed on a KUMA CCD diffracto-
meter system using graphite-monochromated Mo KR
(0.71070 Å) radiation and a low-temperature device [T )
140(2) K]. Crystals suitable for X-ray diffraction studies of 1
were obtained by cooling a CH2Cl2-acetonitrile solution (1:1)
to -25 °C for 1, diffusion of diethyl ether into a THF solution
for 2a, diffusion of pentane into a CHCl3 solution for 4a, and
diffusion of pentane into a CH2Cl2 solution for 7. Data
reductions were performed by CrysAlis RED.28 The structures
of 1, 2a, and 7 were solved with SHELX97,29 and that of 4a
with SIR-97.30 Refinement was performed on PCs using the
SHELX97 software package. Graphical representations of the
structures were made with DIAMOND 3.0. Structures were
solved by direct methods and successive interpretation of the
difference Fourier maps, followed by full matrix least-squares
refinement (against F2). An empirical absorption correction
(DELABS)31 was applied to 1 and 4a. All non-hydrogen atoms
were refined anisotropically except for those of the THF solvent
molecule and carbon atoms C7-C10 in 2a, which were kept
isotropic. In 2a and 7 the structure was restrained using the
DELU command, and some atoms were further restrained
using the ISOR command. The contribution of the hydrogen
atoms, in their calculated positions, were included in the
refinement using a riding model with the exception of the
BH-hydrogen atoms, which were located on the Fourier
difference map and then constrained to equal B-H bond
lengths and H-B-H angles. Some of the fluorine atoms of the
[PF6]- anion in 7 were split over two positions. Relevant
crystallographic data are compiled in Table 3.
2
101.5 (br, C3), 100.0 (C4), 98.8 (br, C5), 93.8 (dd, JPC ) 6,
2
2
JPC ) 4, C6), 90.8 (dd, JPC ) 7, JPC ) 4, C2), 31.3 (C7), 22.5
(C8/9), 18.6 (C8/9), 15.9 (C10). 31P NMR (CD2Cl2, 162 MHz): 129.5
(s). ESI-MS (CH2Cl2) positive ion: m/z +925 [M]+. ESI-MS/
MS(+925): m/z +791 [M - C10H14]+. ESI-MS(CH2Cl2) negative
ion: m/z -145 [PF6]-. Anal. Calcd for C54H46ClF6O2P3Ru: C,
60.59; H, 4.33. Found: C, 60.22; H, 4.31.
Synthesis of 8. A solution of [RuCp(NCCH3)3][PF6] (50 mg,
0.12 mmol) and 1 (40 mg, 0.06 mmol) in acetonitrile (5 mL)
was stirred at room temperature for 1 h, then concentrated,
and diethyl ether was added, resulting in the precipitation of
a yellow-brown solid, which was washed further with Et2O to
afford the product. Yield: 74 mg (89%). 1H NMR (CD2Cl2,
3
3
400 MHz): 8.08 (d, JHH ) 8.1, 2H, H26), 8.04 (d, JHH ) 9.1,
2H, H28), 7.55 (m, 2H, H25), 7.48-7.39 (m, 8H), 7.30 (d, 3JHH
)
8.5, 2H, H23), 7.30 (br, 2H), 7.25 (d, 3JHH ) 9.1, 2H, H29), 7.15-
7.06 (m, 8H), 6.61 (m, 4H), 4.32 (s, 10H, H1), 2.15 (s, 6H, CH3),
1.95 (s, 6H, CH3). 13C NMR (CD2Cl2, 100 MHz): 150.2 (d,
2JPC ) 4, C20), 138.9 (d, 1JPC ) 55), 136.7 (d, 1JPC ) 38), 133.5
(C22), 131.5 (d, 3JPC ) 14), 131.5 (d, 4JPC ) 2), 130.2 (C27), 130.1
(d, 4JPC ) 2), 129.3 (C28), 129.0 (C26), 128.8 (d, 3JPC ) 10), 128.7
2
2
(d, JPC ) 14), 128.1 (d, JPC ) 10), 127.8 (CN), 127.7 (CN),
127.3 (C24), 125.5 (C23), 125.4 (C25), 122.6 (d, JPC ) 6, C21),
3
120.0 (d, JPC ) 8, C29), 77.7 (d, JPC ) 2, C1), 3.9 (CH3), 3.5
(CH3). 31P NMR (CD2Cl2, 162 MHz): 147.6 (s). ESI-MS
(CH2Cl2): m/z +575.3 [M]2+. Anal. Calcd for C62H54F12N4O2P4-
Ru2: C, 51.67; H, 3.78; N, 3.89. Found: C, 52.04; H, 3.79; N,
3.94.
3
2
Acknowledgment. We thank the New Zealand
Foundation for Research, Science and Technology for a
Top Achiever Doctoral Fellowship (A.B.C.), the EPFL,
and the Swiss National Science Foundation for financial
support.
Synthesis of 9. A solution of [RuCp(NCCH3)3][PF6] (50 mg,
0.12 mmol) and 1 (80 mg, 0.12 mmol) in chloroform (25 mL)
was heated to reflux for 1 h, then filtered through a glass fiber
filter, and the solution was concentrated. Addition of diethyl
ether led to the precipitation of the product as a pale yellow,
almost white solid. Yield: 92 mg (79%). 1H NMR (CD2Cl2,
3
3
400 MHz): 7.89 (d, JHH ) 8.1, 1H, H26), 7.79 (d, JHH ) 9.1,
Supporting Information Available: Additional NMR
spectra and crystallographic information files (CIF) of 1, 2a,
4a, and 7 are available free of charge via the Internet at
http://pubs.acs.org.
1H, H28), 7.78 (d, 3JHH ) 8.2, 1H, H26′), 7.62 (d, 3JHH ) 9.1, 1H,
H28′), 7.61 (m, 1H), 7.57-7.39 (m, 13H), 7.18 (d, JHH ) 8.5,
3
1H, H23), 7.14 (d, JHH ) 9.1, 1H, H29), 7.11 (m, 2H), 7.04 (d,
3
3JHH ) 8.2, 1H, H23′), 7.02 (m, 2H), 6.91 (m, 2H), 6.69 (m, 2H),
6.55 (d, 3JHH ) 9.1, 1H, H29′), 4.43 (s, 5H, H1), 1.72 (s, 3H, CH3).
OM050568M
13C NMR (CD2Cl2, 100 MHz): 150.1 (d, JPC ) 6, C20), 149.1
2
(28) CrysAlis RED; Oxford Diffraction Ltd: Abingdon, M. P. OX14
4 RX, UK, 2003.
(29) Sheldrick, G. M. SHELX-97, Structure Solution and Refinement
Package; Universita¨t Go¨ttingen, 1997.
(d, JPC ) 6, C20′), 143.3 (d, JPC ) 48), 141.6 (d, JPC ) 43),
2
1
1
139.6 (d, JPC ) 60), 136.7 (d, JPC ) 59), 133.8 (C22), 133.6
1
1
(C22′), 131.8 (d, JPC ) 2), 131.5 (d, JPC ) 12), 131.4 (d, JPC
)
4
(30) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G. L.;
Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna,
R. J. Appl. Crystallogr. 1999, 32, 115-119.
14), 131.3 (d, JPC ) 2), 130.8 (C27,27′), 130.5 (C28′), 130.3 (d,
4
4JPC ) 2), 130.0 (d, JPC ) 2), 129.9 (d, JPC ) 12), 129.8
4
(d, JPC ) 13), 129.5 (C28), 129.1 (CN), 128.7 (d, JPC ) 10), 128.6
(31) Walker, N.; Stuart, D. Acta Crystallogr. 1983, A39, 158.