Reactions of the dinuclear ruthenium complex {(η5-C5H3)2(SiMe2) 2}Ru2(CO)4, featuring a doubly linked dicyclopentadienyl ligand

Article abstract of DOI:10.1021/om010674y

The complex {(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄ (1), which features the doubly linked dicyclopentadienyl ligand (η⁵-C₅H₃)₂(SiMe₂) ₂, reacts with phosphines (PMe₃, PCy₃, PPh₃) to give {(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)(μ-CO)₂(PR₃) (2a-c), with halogens X₂ (X = Cl, Br, I) to give the Ru-Ru-cleaved products {(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄(X)₂ (3a-c), with X₂ and AgTfO to give [{(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄(μ-X)]⁺TfO^- (X = Cl, Br, I; 4a-c), and with SnCl₂ to give {(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄(μ-SnCl₂) (5), resulting from the insertion of SnCl₂ into the Ru-Ru bond. Reduction of 1 with Na/Hg generates [{(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄]^2- (6), which reacts with (η⁵-C₅H₅)₂TiCl₂ to give {(η⁵-C₅H₃)₂(SiMe₂) ₂}Ru₂(CO)₄{μ-Ti(η⁵-C₅ H₅)₂} (7). Ultraviolet photolysis of 1 with diphenylacetylene and phenylacetylene yields a series of five dinuclear Ru complexes (8-10, 12, 13) containing one or two bridging acetylene units. The rigidity of the doubly linked (η⁵-C₅H₃)₂(SiMe₂) ₂ ligand substantially influences the reactivity and structures of the complexes. Molecular structures of 1, 2a, 3c, 5, 9, 10, and 12 as determined by X-ray diffraction studies are also presented.

Full text of DOI:10.1021/om010674y

Organometallics 2002, 21, 617-627
617
Rea ction s of th e Din u clea r Ru th en iu m Com p lex
{(η5-C5H3)2(SiMe2)2}Ru 2(CO)4, F ea tu r in g a Dou bly Lin k ed
Dicyclop en ta d ien yl Liga n d
Maxim V. Ovchinnikov,† David P. Klein,† Ilia A. Guzei,‡ Moon-Gun Choi,§ and
Robert J . Angelici*,†
Department of Chemistry and Molecular Structure Laboratory, Iowa State University,
Ames, Iowa 50011, and Department of Chemistry and Molecular Structure Laboratory,
Yonsei University, Seoul, Korea 120-749
Received J uly 27, 2001
The complex {(η5-C5H3)2(SiMe2)2}Ru2(CO)4 (1), which features the doubly linked dicyclo-
pentadienyl ligand (η5-C5H3)2(SiMe2)2, reacts with phosphines (PMe3, PCy3, PPh3) to give
{(η5-C5H3)2(SiMe2)2}Ru2(CO)(µ-CO)2(PR3) (2a -c), with halogens X2 (X ) Cl, Br, I) to give
the Ru-Ru-cleaved products {(η5-C5H3)2(SiMe2)2}Ru2(CO)4(X)2 (3a -c), with X2 and AgTfO
to give [{(η5-C5H3)2(SiMe2)2}Ru2(CO)4(µ-X)]+TfO- (X ) Cl, Br, I; 4a -c), and with SnCl2 to
give {(η5-C5H3)2(SiMe2)2}Ru2(CO)4(µ-SnCl2) (5), resulting from the insertion of SnCl2 into
the Ru-Ru bond. Reduction of 1 with Na/Hg generates [{(η5-C5H3)2(SiMe2)2}Ru2(CO)4]2- (6),
which reacts with (η5-C5H5)2TiCl2 to give {(η5-C5H3)2(SiMe2)2}Ru2(CO)4{µ-Ti(η5-C5H5)2} (7).
Ultraviolet photolysis of 1 with diphenylacetylene and phenylacetylene yields a series of
five dinuclear Ru complexes (8-10, 12, 13) containing one or two bridging acetylene units.
The rigidity of the doubly linked (η5-C5H3)2(SiMe2)2 ligand substantially influences the
reactivity and structures of the complexes. Molecular structures of 1, 2a , 3c, 5, 9, 10, and
12 as determined by X-ray diffraction studies are also presented.
In tr od u ction
or 63 metals. To the best of our knowledge, only one
example of a nonmetallocene complex ({(η5-C5H3)2(Si-
Me2)2}Fe2(CO)4) is known for group 8 metals,4a and little
chemistry of this compound has been reported.
We recently reported5 the synthesis (Scheme 1) of the
cationic dinuclear complex [{(η5-C5H3)2(SiMe2)2}Ru2-
(CO)4(µ-H)]+ (1H+), whose carbon monoxide ligands are
activated to attack by amine nucleophiles because of the
positive charge on the complex and the slow rate of
deprotonation of the bridging hydride by the amines.
To develop a general understanding of the effect of
the doubly linked (η5-C5H3)2(SiMe2)2 ligand on the
reactivity of {(η5-C5H3)2(SiMe2)2}Ru2(CO)4 (1), we have
explored the reactions of 1 with phosphines, halogens,
SnCl2, Na/Hg, phenylacetylene, and diphenylacetylene
to give a variety of new complexes. These reactions also
demonstrate the robustness of the bridging system,
which remains unchanged throughout the transforma-
tions.
The doubly linked bis(cyclopentadienyl) ligands (η5-
C5H3)(Linker)2 (Linker ) CH, CH2, CH2CH2, SiMe2,
GeMe2, etc.) have been extensively explored as frame-
works for dinuclear metal complexes that are resistant
to fragmentation and have two metal centers in close
proximity.1
The latter feature is especially attractive for studying
cooperative effects between two reactive metal sites,
since free rotation cannot occur around the Cp-
(Linker)2-Cp linker unit. Most of the known (η5-C5H3)2-
(SiMe2)2-bridged bimetallic complexes contain group 42
* To whom correspondence should be addressed. E-mail: angelici@
iastate.edu.
† Department of Chemistry, Iowa State University.
‡ Molecular Structure Laboratory, Iowa State University.
§ Yonsei University, Molecular Structure Laboratory.
(1) For general reviews of linked bis(cyclopentadienyl) organome-
tallic complexes, see: (a) Barlow, S.; O’Hare, D. Chem. Rev. 1997, 97,
637. (b) Werner, H. Inorg. Chim. Acta 1992, 198-200, 715. (c) Bonifaci,
C.; Ceccon, A.; Gambaro, A.; Mantovani, L.; Ganis, P.; Santi, S.; Venzo,
A. J . Organomet. Chem. 1998, 557, 97. (d) Cuenca, T.; Royo, P. Coord.
Chem. Rev. 1999, 193-195, 447. (e) Royo, P. New J . Chem. 1997, 21,
791.
(2) (a) Go´mez-Garc´ıa, R.; Royo, P. J . Organomet. Chem. 1999, 583,
86. (b) Cano, A.; Cuenca, T.; Go´mez-Sal, P.; Royo, B.; Royo, P.
Organometallics 1994, 13, 1688. (c) Corey, J . Y.; Huhmann, J . L.; Rath,
N. P. Inorg. Chem. 1995, 34, 3203. (d) Cano, A. M.; Cano, J .; Cuenca,
T.; Go´mez-Sal, P.; Manzanero, A.; Royo, P. Inorg. Chim. Acta 1998,
280, 1.
(3) (a) Amor, F.; Go´mez-Sal, P.; de J esu´s, E.; Royo, P.; Va´zquez de
Miguel, A. Organometallics 1994, 13, 4322. (b) Amor, F.; de J esu´s, E.;
Pe´rez, A. I.; Royo, P.; Va´zquez de Miguel, A. Organometallics 1996,
15, 365. (c) Amor, F.; de J esu´s, E.; Royo, P.; Va´zquez de Miguel, A.
Inorg. Chem. 1996, 35, 3440. (d) Galakhov, M. V.; Gil, A.; de J esu´s,
E.; Royo, P. Organometallics 1995, 14, 3746. (e) Amor, F.; Go´mez-Sal,
P.; de J esu´s, E.; Mart´ın, A.; Pe´rez, A. I.; Royo, P.; Va´zquez de Miguel,
A. Organometallics 1996, 15, 2103. (f) Calvo, M.; Galakhov, M. V.;
Go´mez-Garcia, R.; Go´mez-Sal, P.; Mart´ın, A.; Royo, P.; Va´zquez de
Miguel, A. J . Organomet. Chem. 1997, 548, 157.
(4) (a) Siemeling, U.; J utzi, P.; Neumann, B.; Stammler, H. G.;
Hursthouse, M. B. Organometallics 1992, 11, 1328. (b) Hiermeier, J .;
Koehler, F. H.; Mueller, G. Organometallics 1991, 10, 1787.
(5) (a) Ovchinnikov, M. V.; Angelici, R. J . J . Am. Chem. Soc. 2000,
122, 6130. (b) Ovchinnikov, M. V.; Guzei, I. A.; Angelici, R. J .
Organometallics 2001, 20, 691.
10.1021/om010674y CCC: $22.00 © 2002 American Chemical Society
Publication on Web 01/24/2002

618 Organometallics, Vol. 21, No. 4, 2002
Ovchinnikov et al.
to a longer than normal Ru-Ru single bond distance.
The Ru-Ru distance (2.821(1) Å) in (η5:η5-fulvalene)-
Ru2(CO)4,6 where fulvalene is η5:η5-C5H4-C5H4, is also
significantly greater than that in the corresponding
nonlinked complex Cp2Ru2(µ-CO)2(CO)2 (2.735(2) Å).7
Avoidance of nonbonding interactions between the car-
bonyl ligands and alleviation of strain by decreasing the
η5:η5-fulvalene bend were cited to account for this
lengthened Ru-Ru bond. In part, similar arguments
may be applied to 1. Thus, the Ru-Ru distance in 1
(2.8180(3) Å) is longer than that observed in Cp2Ru2-
(CO)2(µ-CO)2 (2.735(2) Å). This difference is partially
due to the preference of the carbonyl ligands in 1 for
an all-terminal arrangement that favors a longer Ru-
Ru distance, which also relieves the strain in the folded
(η5-C5H3)2(SiMe2)2 ligand. Avoidance of nonbonding
contacts between the carbonyl ligands is probably also
responsible for elongation of the Ru-Ru bond and for
the staggered conformation of the CO ligands in 1. It is
worth noting that (η5:η5-fulvalene)Ru2(CO)4 adopts an
eclipsed conformation of the CO ligands, presumably
because the twist around the Ru-Ru axis would lead
to an energetically unfavorable further elongation of the
Ru-Ru bond and/or to an increase in the nonplanarity
of the η5:η5-fulvalene ligand.
F igu r e 1. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO)4 (1) showing the labeling scheme and 30%
probability ellipsoids. Hydrogens are omitted for clarity.
Selected bond distances (Å) and angles (deg) are as fol-
lows: Ru(1)-Ru(1A), 2.8180(3); Ru(1)-C(6), 1.868(2); Ru(1)-
C(7), 1.854(2); Ru(1)-Cp(centroid), 1.907; C(6)-Ru(1)-
C(7), 87.45(9); Ru(1A)-Ru(1)-C(6), 93.04(7); Ru(1A)-
Ru(1)-C(7), 85.15(6); Cp(centroid)-Ru(1)-Ru(1A)-Cp-
(centroid), 24.2; C(7)-Ru(1)-Ru(1A)-C(6A), 32.3; Cp-
Cp fold angle, 122.86.
Su bstitu tion of a CO in 1 by P h osp h in es. Com-
plex 1 reacts at 200 °C with phosphines PR3 (R ) Me,
Cy, Ph) to give monosubstituted complexes of the type
{(η5-C5H3)2(SiMe2)2}Ru2(CO)(µ-CO)2(PR3) (2), where
R ) Me (2a ), R ) Cy (2b), R ) Ph (2c) (Scheme 2). No
disubstituted products were observed. Also, it is worth
noting that the same reaction did not give the clean
formation of 2a under UV photolysis conditions. The IR
spectra of 2a -c in CH2Cl2 exhibit ν(CO) bands at 1977-
Sch em e 1
1967, 1946-1935, 1917-1907, and 1745-1733 cm-1
,
consistent with the presence of both terminal and
bridging isomers of 2a -c in solution. Absorbances in
the ranges 1977-1967 and 1917-1907 cm-1 indicate the
presence of the terminal isomer, while absorbances
between 1946-1935 and 1745-1733 cm-1 correspond
to the bridging isomer. More of the terminal isomer of
2a -c is observed in the low-polarity solvent hexanes
than in CH2Cl2. The IR spectrum of 2a in the solid state
shows approximately equal amounts of the bridging and
nonbridging isomers. The crystal used for the molecular
structure determination of 2a was picked from a mix-
ture of both isomers. The molecular structure of 2a
determined by X-ray diffraction (Figure 2, Table 1)
shows an almost symmetrical disposition of the bridging
CO ligands, which are responsible for the shorter
Ru(1)-Ru(2) distance (2.6579(2) Å) compared to that
observed in 1 (2.8180(3) Å) and, surprisingly, to that
observed in Cp2Ru2(CO)(µ-CO)2(PMe3) (2.722(2) Å).8 The
shorter Ru(1)-Ru(2) distance in 2a may also be favored
by the doubly linked (η5-C5H3)2(SiMe2)2 ligand, which
adopts a smaller Cp-Cp fold angle (119.0°), compared
to that (122.86°) in complex 1, which relieves unfavor-
able steric interactions between the bridging CO ligands
and the equatorial SiMe2 methyl groups. This argument
is also supported by the smaller dihedral angle between
Resu lts a n d Discu ssion
Cr ystal Str u ctu r e of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4
(1). The starting complex 1, whose synthesis (Scheme
1) was recently reported,5 has a structure (Figure 1,
Table 1) that contains two ruthenium atoms linked by
a bridging (η5-C5H3)2(SiMe2)2 ligand and a metal-metal
bond, with four terminal CO ligands bound in a sym-
metrical and staggered array ( C(7)-Ru(1)-Ru(1A)-
C(6A) ) 32.3°). The staggered character of the molecule
is also reflected by a significant twist around the Ru(1)-
Ru(1A) axis ( Cp(centroid)-Ru(1)-Ru(1A)-Cp(cen-
troid) ) 24.2°). The fold angle between the planes of the
Cp rings of the (η5-C5H3)2(SiMe2)2 ligand is relatively
large (122.86°), suggesting that the normally planar
(η5-C5H3)2(SiMe2)2 fragment (e.g. in trans-{(η5-C5H3)2-
(SiMe2)2}Li2(TMEDA)2)4b is somewhat strained, leading
(6) Boese, R.; Cammack, J . K.; Matzger, A. J .; Pflug, K.; Tolman,
W. B.; Vollhardt, K. P. C.; Weidman, T. W. J . Am. Chem. Soc. 1997,
119, 6757.
(7) Mills, D. S.; Nice, J . P. J . Organomet. Chem. 1967, 9, 339.
(8) Nataro, C.; Angelici, R. J . Inorg. Chem. 1998, 37, 2975.

An Ru Complex with a Dicyclopentadienyl Ligand
Organometallics, Vol. 21, No. 4, 2002 619

620 Organometallics, Vol. 21, No. 4, 2002
Ovchinnikov et al.
Sch em e 2
by the torsion angles Cp(centroid)-Ru(1)-Ru(2)-
Cp(centroid) (0.1°) and C(6)-Ru(1)-Ru(2)-P (0.5°).
Rea ction s of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4 (1)
w ith Ha logen s. Syn th esis of {(η5-C5H3)2(SiMe2)2}-
Ru 2(CO)4(X)2 (3a -c) a n d [{(η5-C5H3)2(SiMe2)2}Ru 2-
(CO)4(µ-X)]+TfO- (4a -c). It is well-known9 that the
dimeric Cp′2M2(CO)4 (M ) Fe, Ru, Os) complexes react
with halogens (X2) to give metal(II) halide carbonyl
complexes Cp′M(CO)2X. Similarly, complex 1 reacts with
X2 (X ) Cl, Br, I) in CH2Cl2 at room temperature to give
complexes 3a -c (Scheme 2) (71-85% yield), which were
isolated as yellow air-stable solids. Their IR spectra in
hexanes solutions show the expected two strong ν(CO)
absorptions in the ranges 2052-2060 and 2000-2006
1
cm-1. Their H NMR spectra at room temperature show
a doublet and a triplet in the range δ 5.21-5.49 for the
protons of each cyclopentadienyl ring, consistent with
an AB2 spin system. This pattern remains unchanged
at low temperature (-50 °C). An X-ray structural
determination of 3c shows (Figure 3, Table 1) that the
asymmetric unit contains three different molecules. In
each of these molecules the Ru atoms exhibit a three-
legged piano-stool geometry. The most interesting fea-
ture of the structure is the almost flat conformation of
the (η5-C5H3)2(SiMe2)2 ligand ( Cp-Cp fold angle 175.9°),
which is consistent with the long Ru-Ru nonbonding
distance (4.9762 Å). The cyclopentadienyl rings of the
bridging ligand are slightly twisted with respect to each
other, which is evident in the torsion angle Cp(cen-
troid)-Ru(1)-Ru(2)-Cp(centroid) (5.3°). This twist may
reflect steric repulsions between the cissoid Ru(CO)2I
units.
The halide-bridged cationic complexes {Cp2Ru2(CO)4-
(µ-X)}+ can be isolated from aromatic solvents as inter-
mediates from reactions of Cp2Ru2(CO)4 and halogens
(X2) in the presence of large counterions.10 Although we
did not observe similar intermediates in the reactions
of 1 with halogens, the corresponding cationic, halide-
bridged complexes [{(η5-C5H3)2(SiMe2)2}Ru2(CO)4(µ-
X)]+TfO- (4a -c) were readily accessible as air-stable
F igu r e 2. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO)(µ-CO)2(PMe3) (2a ) showing the labeling
scheme and 30% probability ellipsoids. Hydrogens are
omitted for clarity. Selected bond distances (Å) and angles
(deg) are as follows: Ru(1)-Ru(2), 2.6579(2); Ru(1)-C(6),
1.848(2); Ru(1)-C(7), 2.104(2); Ru(1)-C(8), 2.088(2); Ru(2)-
C(7), 1.992(2); Ru(2)-C(8), 1.998(2); Ru(2)-P, 2.2770(6);
Ru(1)-Cp(centroid), 1.936(2); Ru(2)-Cp(centroid), 1.910;
C(6)-Ru(1)-C(7), 86.45(9); C(6)-Ru(1)-C(8), 86.96(9);
C(7)-Ru(1)-C(8), 84.78(8); P-Ru(2)-C(7), 85.98(6);
P-Ru(2)-C(8), 86.27(6); C(7)-Ru(2)-C(8), 90.20(8);
Ru(1)-Ru(2)-P, 111.833(17); Ru(2)-Ru(1)-C(6), 110.21-
(7); Cp(centroid)-Ru(1)-Ru(2)-Cp(centroid), 0.1; C(6)-
Ru(1)-Ru(2)-P, 0.5; Cp-Cp fold angle, 119.0.
the Ru(1)-C(7)-Ru(2) and Ru(1)-C(8)-Ru(2) planes
(130.5°), compared to that found in Cp2Ru2(CO)(µ-
CO)2(PMe3) (155.5°). The Ru(2)-C(7) and Ru(2)-C(8)
distances (1.992(2), 1.998(2) Å) are shorter than the
Ru(1)-C(7) and Ru(1)-C(8) distances (2.104(2), 2.088(2)
Å), as expected for the more electron-rich Ru(2) center.
There is no twist around the Ru-Ru bond, as indicated
(9) Bennett, M. A.; Bruce, M. I.; Matheson, T. W. In Comprehensive
Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E W.,
Eds., Pergamon Press: Oxford, New York, 1982; Vol. 4, p 821.
(10) Haines, R. J .; duPreez, A. L. C. J . Chem. Soc., Dalton Trans.
1972, 944.

An Ru Complex with a Dicyclopentadienyl Ligand
Organometallics, Vol. 21, No. 4, 2002 621
F igu r e 3. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO)4(I)2 (3c) showing the labeling scheme and
30% probability ellipsoids; hydrogens are omitted for
clarity. Selected bond distances (Å) and angles (deg) are
as follows: Ru(1)- -Ru(2), 4.9762; Ru(1)-I(1), 2.7070(7);
Ru(1)-C(15), 1.878(7); Ru(1)-C(16), 1.882(9); Ru(1)-Cp-
(centroid), 1.883; Ru(2)-Cp(centroid), 1.872; I(1)-Ru(1)-
C(15), 90.7(2); I(1)-Ru(1)-C(16), 85.7(4); C(16)-Ru(1)-
C(15), 88.2(3); Cp(centroid)-Ru(1)-Ru(2)-Cp(centroid),
5.3; Cp-Cp fold angle, 175.9.
F igu r e 4. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}(CO)4(µ-SnCl2) (5) showing the labeling scheme and
30% probability ellipsoids. Hydrogens are omitted for
clarity. Selected bond distances (Å) and angles (deg) are
as follows: Ru(1)- -Ru(2), 4.625; Ru(1)-C(6), 1.874(4);
Ru(1)-C(7), 1.887(4); Ru(1)-Sn(1), 2.6066(4); Ru(2)-C(17),
1.875(4); Ru(2)-C(18), 1.864(5); Ru(2)-Sn(1), 2.6034(4);
Sn(1)-Cl(1), 2.4497(9); Sn(1)-Cl(2), 2.4465(9); Ru(1)-
Cp(centroid), 1.895; Ru(2)-Cp(centroid), 1.887; C(7)-
Ru(1)-C(6), 92.68(17); C(6)-Ru(1)-Sn(1), 87.02(12);
C(7)-Ru(1)-Sn(1), 88.29(12); Cl(1)-Sn(1)-Cl(2), 92.73-
(3); Ru(1)-Sn(1)-Ru(2), 125.162(13); Ru(1)-Sn(1)-
Cl(1), 109.24(3); Cp(centroid)-Ru(1)-Ru(2)-Cp(centroid),
3.1; Cp-Cp fold angle, 171.1.
solids (51-85% yield) by the reaction of complex 1 and
X2 (X ) Cl, Br, I) in the presence of a large excess of
AgTfO at room temperature. It is worth mentioning
that, in contrast to the corresponding monolinked ([{(η5-
C5H4)2(SiMe2)}Ru2(CO)4(µ-X)]+)11 and nonlinked ({Cp2-
Ru2(CO)4(µ-X)}+)9 Ru complexes, compounds 4a -c do
not react with an excess of AgTfO further in acetonitrile
to give the dicationic complexes [{(η5-C5H3)2(SiMe2)2}-
Ru2(CO)4(MeCN)2]2+; this indicates an unusual stability
of the bridging halide in the complexes with the doubly
than that (2.8180(3) Å) in complex 1 but shorter than
that (4.9762 Å) in 3c. The long Ru-Ru distance in 5
leads to a Cp-Cp fold angle that is significantly larger
(171.1°) than that (122.86°) in complex 1 but smaller
than that (175.9°) in 3c. The twist around the Ru-Ru
axis is minimal, which is reflected in the small Cp-
(centroid)-Ru(1)-Ru(2)-Cp(centroid) torsion angle (3.1°).
Gen er a t ion of [{(η5-C5H 3)2(SiMe2)2}R u 2(CO)4]2-
(6) a n d Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4-
{µ-Ti(η5-C5H5)2} (7). It is known9 that the dimeric
Cp′2Ru2(CO)4 complexes react with Na amalgam to give
the anionic complexes Cp′Ru(CO)2-, which can react
with various electrophiles (MeI, Me3SnCl, etc.). The
related anionic complex [{(η5-C5H3)2(SiMe2)2}Ru2(CO)4]2-
(6) was generated in situ from the reaction of 1 with
Na/Hg but was too reactive to be isolated. However, 6
reacts with 1 equiv of (η5-C5H5)2TiCl2 at room temper-
ature in THF to give {(η5-C5H3)2(SiMe2)2}Ru2(CO)4{µ-
Ti(η5-C5H5)2} (7) (Scheme 3; 53%), which was isolated
as extremely moisture-sensitive pale yellow crystals.
The ν(CO) bands of 7 at 1938 and 1876 cm-1 are shifted
to lower energy from the corresponding bands (2025 and
1967 cm-1) of 1, as expected for complexes of this type:
for example, (η5-C5H5)2Ru2(CO)4{µ-Zr(η5-C5H5)2}.13 The
two Ti-Cp groups are equivalent in the 1H NMR
spectrum. Unfortunately, we were unable to obtain
X-ray-quality crystals of 7.
1
linked (η5-C5H3)2(SiMe2)2 ligand. The H NMR spectra
of 4a -c show a doublet and a triplet (AB2 spin system)
for the equivalent cyclopentadienyl rings and two sin-
glets for the methyl groups in the SiMe2 groups of the
ligand, as expected for a symmetrical structure.
In ser tion of Sn Cl2 in to th e Ru -Ru Bon d in 1.
Stannous chloride (SnCl2) has been reported12 to react
with Cp2M2(CO)4 (M ) Fe, Ru) complexes to give the
products Cp2M2(CO)4(µ-SnCl2), in which the Sn inserts
into the M-M bond. When 1 and SnCl2 are refluxed in
THF for 30 h, {(η5-C5H3)2(SiMe2)2}Ru2(CO)4(µ-SnCl2) (5)
is obtained in 74% yield as an air-stable yellow crystal-
1
line solid. The H NMR spectrum of 5 shows a doublet
and a triplet at δ 5.58 and 5.64 for the protons in the
equivalent cyclopentadienyl rings and two singlets for
the different CH3 protons in the SiMe2 groups. The IR
spectrum exhibits three strong ν(CO) bands in the
1986-2038 cm-1 region. A single-crystal X-ray struc-
tural determination (Figure 4, Table 1) of 5 shows that
three different molecules are present in the asymmetric
unit. In all three molecules, each Ru has a three-legged
piano-stool structure. The Ru-Sn bond distances are
almost identical in all three molecules (2.6034(4)-
2.6066(4) Å). The presence of the bridging SnCl2 ligand
leads to an Ru-Ru distance of 4.625 Å, much longer
Reaction of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4 (1) with
Dip h en yla cetylen e. Syn th esis of {(η5-C5H3)2(Si-
Me2)2}Ru 2(CO)2(µ-CO){η1:η1-µ2-C(P h )C(P h )} (8), {(η5-
C5H3)2(SiMe2)2}Ru 2(CO){η2:η4-µ2-C(P h )C(P h )C(P h )-
(11) Fro¨hlich, R.; Gimeno, J .; Gonza´lez-Cueva, M.; Lastra, E.; Borge,
J .; Garc´ıa-Granda, S. Organometallics 1999, 18, 3008.
(12) Zhang, Y.; Xu, S.; Tian, G.; Zhang, W.; Zhou, X. J . Organomet.
Chem. 1997, 544, 43 and references therein.
(13) Casey, C. P.; J ordan, R. F.; Rheingold, A. L. Organometallics
1984, 3, 504.

622 Organometallics, Vol. 21, No. 4, 2002
Ovchinnikov et al.
Sch em e 3
-0.62 and 0.36. The δ -0.62 signal is approximately
0.7 ppm upfield from the typical Si(CH3)2 region and
indicates a pronounced shielding of the equatorial
methyl groups by the nearby phenyl rings. The X-ray
structure of 9 (Figure 5, Table 1), which is discussed in
more detail below, confirms a close nonbonding interac-
tion (3.435 Å) between the SiMe2 equatorial methyl
groups and the π-systems of phenyl groups 2 and 5.
C(P h )} (9), a n d {(η5-C5H3)2(SiMe2)2}Ru 2(CO){η2:η4-
µ2-C(dO)C(P h )C(P h )C(P h )C(P h )} (10). Ultraviolet
irradiation of a benzene solution containing 1 and 4
equiv of diphenylacetylene for 25 h produces the bime-
tallic Ru complexes 8-10 (Scheme 4), which were
successfully separated by chromatography. There was
no evidence for the formation of a {(η5-C5H3)2(SiMe2)2}-
based diruthenacyclopentenone analogous to 11, which
is obtained upon photolysis of Cp2Ru2(CO)4 in the
presence of alkynes (e.g. mono- and diphenylacetyl-
ene).14
1
The variable-temperature H NMR spectrum of 9 in
CD2Cl2 in the aromatic region is shown in Figure 6. At
-50 °C, the spectrum consists of 10 (δ 6.42, 6.58, 6.65,
6.77, 6.83, 6.88, 7.03, 7.09, 7.12, 7.62) well-resolved
resonances of equal intensity. As the temperature is
increased to -20 °C, 4 of the 10 resonances (δ 6.58, 6.77,
7.09, 7.62) coalesce to a single broad resonance, which
is almost indistinguishable from the baseline. At +25
°C a new broad signal is observed at δ 7.25 ppm and
the signal at δ 6.88 ppm gains intensity and broadens,
while the other 5 resonances at δ 7.12, 7.03, 6.83, 6.65,
and 6.42 remain virtually unchanged. We can assign
the latter set of five resonances to the equivalent phenyl
rings 3 and 4, which are not fluxional with respect to
rotation around the C(3 or 4)-phenyl bond in the -50
to +25 °C temperature range. A H-1H COSY experi-
1
Complex 8, which was obtained as dark red, air-
sensitive crystals, was identified by characteristic pat-
ment demonstrates the mutual coupling of these 5
signals. Broad resonances at δ 7.25 and 6.88 ppm
(+25 °C) are assigned to the ortho and meta protons of
the equivalent phenyl groups 2 and 5, indicating flux-
ionality at room temperature on the NMR time scale.
The simplest explanation for the temperature-depend-
ent appearance of phenyl groups 2 and 5 in the 1H NMR
spectra is the lack of free rotation around the C(2 or
5)-phenyl bond at -50 °C, when five signals are
observed. An NOE experiment indicates the presence
of a weak through-space interaction between the equa-
torial SiMe2 methyl groups and phenyl rings 2 and 5.
As the temperature is increased to +25 °C, this rota-
tional motion becomes semirestricted. Further sharpen-
ing of resonances at δ 7.25 and 6.88 ppm in the 1H NMR
spectra was observed at temperatures up to +50 °C.
In the molecular structure of 9 (Figure 5, Table 1),
there is an approximate (noncrystallographic) mirror
plane containing Ru(1), Ru(2), and the centroids of the
two Cp rings. The Ru(1)-Ru(2) distance is 2.6221(6) Å,
corresponding to a single Ru-Ru bond. The two ruthe-
nium atoms are bridged by a {η2:η4-µ2-C(Ph)C(Ph)C(Ph)-
C(Ph)} fragment, the ends of which are σ-bonded to
Ru(1), forming a metallacyclopentadiene ring. The
Ru(1)-C(2) and Ru(1)-C(5) distances of 2.100(4) and
2.096(4) Å are consistent with Ru-C single bonds, as
1
terns in its H NMR and IR spectra, which are similar
to those of the known analogous complexes {(η5-C5H4)2-
(CMe2)}Ru2(CO)2(µ-CO){η1:η1-µ2-C(Ph)C(Ph)}15 and {(η5-
C5H4)2}Ru2(CO)2(µ-CO){η1:η1-µ2-CHCH}.6 In the 1H NMR
spectrum, the presence of three signals in the cyclopen-
tadienyl region and four signals corresponding to the
Si(CH3)2 methyl groups are consistent with the proposed
structure of 8. Its IR spectrum (ν(CO): 1983, 1935, and
1753 cm-1) indicates the presence of both terminal and
bridging CO ligands.
Complex 9 is an air-stable orange crystalline solid
that is soluble in benzene and CH2Cl2 and moderately
soluble in nonpolar solvents (hexanes). The IR spectrum
of 9 in hexanes shows only one sharp ν(CO) band at
1969 cm-1, which corresponds to the terminal CO ligand
coordinated to one of the Ru atoms. The 1H NMR
spectrum of 9 exhibits resonances for the inequivalent
Cp rings (each displays a unique AB2 splitting pattern)
and two signals for the Si(CH3)2 methyl groups at δ
(14) (a) Albers, M. O.; Robinson, D. J .; Singleton, E. Coord. Chem.
Rev. 1987, 79, 1. (b) Davies, D. L.; Dyke, A. F.; Knox, S. A. R.; Morris,
M. J . J . Organomet. Chem. 1981, 215, C30
(15) (a) Nelson, G. O.; Wright, M. E. J . Organomet. Chem. 1981,
206, C21. (b) Knox, S. A. R.; Macpherson, K. A.; Orpen, A. G.; Rendle,
M. C. J . Chem. Soc., Dalton Trans. 1989, 1807.

An Ru Complex with a Dicyclopentadienyl Ligand
Organometallics, Vol. 21, No. 4, 2002 623
Sch em e 4
F igu r e 5. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO){η2:η4-µ2-C(Ph)C(Ph)C(Ph)C(Ph)} (9) show-
ing the labeling scheme and 30% probability ellipsoids.
Hydrogens are omitted for clarity. Selected bond distances
(Å) and angles (deg) are as follows: Ru(1)-Ru(2), 2.6221(6);
Ru(1)-C(6), 1.845(6); Ru(1)-C(5), 2.096(4); Ru(1)-C(2),
2.100(4); C(2)-C(3), 1.428(6); C(3)-C(4), 1.438(6); C(4)-
C(5), 1.424(6); Ru(1)-Cp(centroid), 1.936; Ru(2)-Cp-
(centroid), 1.829; Ru(2)-ruthenacyclopentadiene(Ru(1),-
C(2)-C(5))(centroid), 1.753; C(8)-phenyl(C51-C(56)(cen-
troid), 3.435; C(6)-Ru(1)-C(5), 80.8(2); C(6)-Ru(1)-
C(2), 79.9(2); C(5)-Ru(1)-C(2), 78.05(17); Cp(centroid)-
Ru(2)-ruthena cyclopenta diene(Ru(1),C(2)-C(5))(cen-
troid), 172.17; Cp-Cp fold angle, 118.83.
1
F igu r e 6. Variable-temperature H NMR spectra in the
aromatic region of 9 in CD2Cl2 at 400 MHz.
The mean plane of the C(2)-C(3)-C(4)-C(5) fragment
is nearly parallel ( Cp(centroid)-Ru(2)-ruthenacyclo-
pentadiene(Ru(1),C(2)-C(5))(centroid) ) 172.17°) to the
plane of the cyclopentadienyl ring bound to Ru(2), giving
Ru(2) a pseudo-metallocene coordination environment.
The phenyl groups C(31)-C(36) and C(41)-C(46) are
almost orthogonal to the C(2)-C(3)-C(4)-C(5) plane
(76.4 and 80.6°), while the phenyl groups C(21)-C(26)
and C(51)-C(56) have tilt angles of 50.7 and 51.5°, due
to close through-space interactions with the equatorial
methyl groups of the SiMe2 linkers. Structural features
of 9 are similar to those of other dinuclear ruthenacy-
clopentadiene complexes such as (η5-C5Me5)Cl2Ru2(η2:
η4-µ2-C4H4)(η5-C5Me5),17 (η5-C5Me5)(CO)Ru{η2:η4-µ2-C-
(Tol)CHC(Tol)CH}Co(CO)2,17 and [(η5-C5Me5)(MeCN)Ru-
(η2:η4-µ2-C4H2Ph2)Ru(η5-C5Me5)](CF3SO3).19
are the Ru(2)-C(2) and Ru(2)-C(5) lengths of 2.133(5)
and 2.130(4) Å. The Ru(1)-C(2)-C(3)-C(4)-C(5) ring
may be viewed as being π-bound to Ru(2), but this
bonding does not result in the geometry observed for
other related dinuclear complexes, such as (η2-MeCC-
Me)W2(OPri)5(µ2-OPri)(η2:η4-µ2-C4Me4), which contains
planar rings.16 Instead, the Ru(1)-C(2)-C(3)-C(4)-
C(5) ring is puckered, with Ru(1) lying 0.41 Å out of
the least-squares plane defined by carbon atoms C(2)-
C(5) and away from Ru(2). The angle between the C(2)-
C(3)-C(4)-C(5) and Ru(1)-C(2)-C(5) planes is 166.78°.
(17) Campion, B. K.; Heyn, R. H.; Tilley, T. D. Organometallics 1990,
9, 1106.
(18) Matsuzaka, H.; Ichikawa, K.; Ishioka, T.; Sato, H.; Okubo, T.;
Ishii, T.; Yamashita, M.; Kondo, M.; Kitagawa, S. J . Organomet. Chem.
2000, 596, 121.
(19) He, X. D.; Chaudret, B.; Dahan, F.; Huang, Y.-S. Organome-
tallics 1991, 10, 970.
(16) (a) Chisholm, M. H.; Hoffman, D. M.; Huffman, J . C. J . Am.
Chem. Soc. 1984, 106, 6806. (b) Bruce, M. I.; Matisons, J . G.; Skelton,
B. W.; White, A. H. J . Organomet. Chem. 1983, 251, 249.

624 Organometallics, Vol. 21, No. 4, 2002
Ovchinnikov et al.
F igu r e 8. Structure of the core of {(η5-C5H3)2(SiMe2)2}-
Ru2(CO){η2:η4-µ2-C(dO)C(Ph)C(Ph)C(Ph)C(Ph)} (10).
IR spectrum of 10 in hexanes shows one sharp CO band
at 1973 cm-1, which corresponds to the terminal CO
ligand coordinated to Ru(1), and a weak broad band at
1601 cm-1, which may be assigned to the acyl CO group
in the ruthenacyclohexadienone fragment.
F igu r e 7. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO){η2:η4-µ2-C(dO)C(Ph)C(Ph)C(Ph)C(Ph)} (10)
showing the labeling scheme and 30% probability ellipsoids.
Hydrogens are omitted for clarity. Selected bond distances
(Å) and angles (deg) are as follows: Ru(1)-Ru(2), 2.7118(6);
Ru(1)-C(6), 1.856(5); Ru(1)-C(5), 2.083(4); Ru(1)-C(1),
2.029(4); C(1)-O(1), 1.219(5); C(1)-C(2), 1.482(6); C(2)-
C(3), 1.444(5); C(3)-C(4), 1.431(5); C(4)-C(5), 1.431(5);
Ru(2)-C(1), 2.796; Ru(2)-C(2), 2.274(4); Ru(2)-C(3),
2.211(4); Ru(2)-C(4), 2.226(4); Ru(2)-C(5), 2.110(4); Ru(1)-
Cp(centroid), 1.967; Ru(2)-Cp(centroid), 1.848; Ru(2)-
ruthenacyclopentadiene(Ru(1),C(2)-C(5))(centroid), 1.769;
C(10)-phenyl(C51-C56)(centroid), 3.476; C(6)-Ru(1)-
C(5), 78.47(17); C(6)-Ru(1)-C(1), 78.54(17); C(5)-
Ru(1)-C(1), 95.00(17); Cp(centroid)-Ru(2)-ruthenacyclo-
pentadiene(Ru(1),C(2)-C(5))(centroid), 174.27; Cp-Cp
fold angle, 123.53.
Reaction of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4 (1) with
P h en ylacetylen e. Syn th esis of {(η5-C5H3)2(SiMe2)2}-
Ru 2(CO)2(µ-CO)(µ-CdCHP h ) (12) a n d {(η5-C5H3)2-
(SiMe2)2}R u 2(CO){η2:η4-µ2-C(H )C(P h )C(H )C(P h )}
(Mixtu r e of Isom er s) (13). Ultraviolet irradiation of
a solution containing 1 and 4 equiv of phenylacetylene
(Scheme 4) in benzene solvent yields a mixture of
products, which were identified as complexes 12 and 13
on the basis of spectral evidence. In contrast, ultraviolet
irradiation of Cp2Ru2(CO)4 and phenylacetylene gives
exclusively a complex of type 11 (R, R ) H, Ph), which
undergoes thermal (110 °C, toluene) rearrangement to
the bridging vinylidene complex Cp2Ru2(CO)2(µ-CO)(µ-
CdCHPh).20 The structure of 12 (Figure 9, Table 1) was
conclusively established by an X-ray crystallographic
analysis. The bridging µ-CdCHPh vinylidene ligand is
planar ( Ru(1)-C(18)-C(19)-C(20) ) 0.2°) and bound
almost symmetrically to both Ru atoms (Ru(1)-C(18)
) 2.049(6) Å; Ru(2)-C(18) ) 2.028(7) Å). As in complex
2a , the Ru(1)-Ru(2) distance (2.6551(7) Å) is shorter
compared to that (2.696(1) Å) in the nonlinked analo-
gous complex Cp2Ru2(CO)2(µ-CO)(µ-CdCH2).20 The Cp-
Cp fold angle (118.5°) is smaller compared to the same
parameter (122.86°) for 1. In fact, the structures of 12
and 2a , especially the geometries around the Ru atoms,
are very similar.
Spectroscopic and structural features of {(η5-C5H3)2-
(SiMe2)2}Ru2(CO){η2:η4-µ2-C(dO)C(Ph)C(Ph)C(Ph) C(Ph)}
(10) are similar to those of complex 9. Compound 10
differs from 9 only by the insertion of a CO group into
a Ru(1)-C(2 or 5) bond of 9. This leads to the lack of a
mirror plane, which was present in complex 9. As a
1
result of the lower symmetry, the H NMR spectrum of
10 exhibits resonances for the inequivalent Cp rings
(each displays a unique ABC splitting pattern) and four
signals for the Si(CH3)2 methyl groups at δ -1.00, 0.31,
0.36, and 0.57. The upfield signal indicates shielding of
an equatorial methyl group by a nearby phenyl ring.
The X-ray structure of 10 (Figure 7, Table 1) supports
this close nonbonding interaction (3.476 Å) between the
equatorial methyl C(10) and the plane of phenyl ring
C(51)-C(56). The η5 binding mode of the ruthenacyclo-
hexadienone fragment to Ru(2) is supported by a long
C(1)-C(2) bond (1.482(6) Å) compared to the C-C bonds
in the delocalized C(2)-C(3)-C(4)-C(5) (1.444(5),
1.431(5), 1.431(5) Å) π-system and a nonbonding Ru(2)-
C(1) distance (2.796 Å). The conformation of the ruthe-
nacyclohexadienone Ru(1)-C(1)-C(2)-C(3)-C(4)-C(5)
ring (Figure 8) cannot be described simply, because of
significant out-of-plane deviations of each atom; the
smallest dihedral angle in the Ru(1)-C(1)-C(2)-C(3)-
C(4)-C(5) ring is C(2)-C(3)-C(4)-C(5) (10.3°). The
1
In the H NMR spectrum of 12, the cyclopentadienyl
hydrogens occur as six sets of well-resolved multiplets;
in addition, there are four singlet methyl resonances for
the SiMe2 groups, which are consistent with the sym-
metry of the solid-state molecule and indicate the
absence of rotation around the C(18)-C(19) bond of the
vinylidene ligand. In the IR spectrum of 12, bands for
both terminal (2008, 1982 cm-1) and bridging (1819
cm-1) carbonyl absorptions are evident.
We were unable to obtain X-ray-quality crystals of 13,
due in part to the fact that this compound is formed as
(20) Colborn, R. E.; Davies, D. L.; Dyke, A. F.; Endesfelder, A.; Knox,
S. A. R.; Orpen, A. G., Plaas, D. J . Chem. Soc., Dalton Trans. 1983,
2661.

An Ru Complex with a Dicyclopentadienyl Ligand
Organometallics, Vol. 21, No. 4, 2002 625
robustness of the (η5-C5H3)2(SiMe2)2 ligand, which re-
mains unchanged in reactions of {(η5-C5H3)2(SiMe2)2}-
Ru2(CO)4 (1) with phosphines, halogens, SnCl2, and Na/
Hg to give a variety of new dinuclear doubly linked
ruthenium(II) complexes.
Exp er im en ta l Section
Gen er a l P r oced u r es. All reactions were performed under
an argon atmosphere in reagent grade solvents, using standard
Schlenk or drybox techniques.21 Hexanes, methylene chloride,
and diethyl ether were purified by the Grubbs method prior
to use.22 All other solvents were purified by published meth-
ods.23 Chemicals were purchased from Aldrich Chemical Co.,
unless otherwise mentioned, or prepared by literature meth-
ods, as referenced below. Alumina (neutral, activity I, Aldrich)
was degassed under vacuum for 12 h and treated with Ar-
saturated water (7.5% w/w). 1H and 13C NMR spectra were
recorded on a Bruker DRX-400 spectrometer using deuterated
solvents as internal references. Solution infrared spectra were
recorded on a Nicolet-560 spectrometer using NaCl cells with
0.1 mm spacers. Elemental analyses were performed on a
Perkin-Elmer 2400 series II CHNS/O analyzer.
All photochemical reactions were carried out in 60 or 300
mL quartz Schlenk photolysis tubes fitted with a cold-finger
condenser (which is immersed in the reaction solution) and
using a Hanovia 450 W medium-pressure Hg lamp with a
quartz jacket as the ultraviolet light source. The temperature
of each reaction was controlled using an Isotemp 1013P
refrigerated circulating bath (Fisher Scientific) with the
circulating hoses connected to the cold finger.
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)3(P Me3) (2a ).
To a solution of 1 (30 mg; 0.05 mmol) in decane (1 mL) in a
thick-walled Pyrex tube was added PMe3 (15 µL; 0.15 mmol).
The mixture was degassed, sealed under vacuum, heated to
200 °C for 24 h, and cooled to room temperature; the volatiles
were removed under vacuum. The resulting orange-red residue
was redissolved in CH2Cl2 (3 mL), and the solution was filtered
through a short pad (3 cm) of alumina. Subsequent addition
of hexanes (5 mL) and cooling (-20 °C) afforded crystalline
2a (23 mg, 58%) as orange blades. 1H NMR (400 MHz,
CD2Cl2): δ 0.39 (s, 6 H, Si(CH3)), 0.44 (s, 6 H, Si(CH3)), 1.41
(d, J P-H ) 9.6 Hz, 9 H, P(CH3)3), 5.08 (d, J ) 2.4 Hz, 2 H,
Cp-H), 5.22 (m, 1 H, Cp-H), 5.39 (d, J ) 2.4 Hz, 2 H, Cp-H),
5.84 (m, 1 H, Cp-H). 13C NMR (100 MHz, CD2Cl2): δ -2.50,
3.96 (Si(CH3)2), 22.40 (d, J P-C ) 30.5 Hz, P(CH3)3), 86.67, 89.35,
91.41, 93.58, 95.66 (d, J P-C ) 3.6 Hz, Cp-C), 98.97 (Cp), 207.66,
220.28 (d, J P-C ) 10.9 Hz, CO). 31P{1H} NMR (161 MHz,
CD2Cl2): δ 11.5 (s). IR (CH2Cl2): ν(CO) (cm-1) 1968 (vs), 1935
(m), 1907 (vs), 1733 (m). IR (hexanes): ν(CO) (cm-1) 1981 (vs),
1955 (w), 1917 (vs), 1905 (w), 1752 (w). IR (solid state, on PTFE
tape): ν(CO) (cm-1) 1959 (vs), 1929 (s), 1901 (vs), 1881 (s), 1739
(s). Anal. Calcd for C20H27O3PRu2Si2: C, 39.72; H, 4.50.
Found: C, 39.38; H, 4.13.
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)3(P Cy3) (2b).
A solution of 1 (30 mg, 0.053 mmol) in decane (1 mL) was
reacted with PCy3 (48 mg, 0.17 mmol) at 200 °C for 36 h, as
in the preparation of 2a . Two crystallizations of the resulting
orange-red solid from CH2Cl2-hexanes gave 2b (29 mg, 74%)
as red prisms. 1H NMR (400 MHz, CD2Cl2): δ 0.46 (s, 6 H,
Si(CH3)), 0.66 (s, 6 H, Si(CH3)), 1.56-2.04 (complex m, 33 H,
P(C6H11)3), 5.10 (d, J ) 2.1 Hz, 2 H, Cp-H), 5.56 (d, J ) 2.1
Hz, 2 H, Cp-H), 5.79 (t, J ) 2.1 Hz, 1 H, Cp-H), 5.90 (m, 1 H,
Cp-H). 31P{1H} NMR (161 MHz, CD2Cl2): δ 49 (s). IR (CH2-
F igu r e 9. Thermal ellipsoid drawing of {(η5-C5H3)2(Si-
Me2)2}Ru2(CO)2(µ-CO)(µ-CdCHPh) (12) showing the label-
ing scheme and 30% probability ellipsoids. Hydrogens are
omitted for clarity. Selected bond distances (Å) and angles
(deg) are as follows: Ru(1)-Ru(2), 2.6551(7); Ru(1)-C(18),
2.049(6); Ru(2)-C(18), 2.028(7); C(18)-C(19), 1.312(8);
C(19)-C(20), 1.475(8); Ru(1)-C(17), 2.023(7); Ru(2)-C(17),
2.060(6); Ru(1)-Cp(centroid), 1.919; Ru(2)-Cp(centroid),
1.918; C(6)-Ru(1)-C(17), 86.4(3); C(6)-Ru(1)-C(18),
83.8(2); C(18)-Ru(1)-C(17), 87.9(2); C(16)-Ru(2)-
C(17), 83.8(2); C(16)-Ru(2)-C(18), 86.5(3); C(18)-
Ru(2)-C(17), 87.4(2); Ru(1)-Ru(2)-C(16), 108.76(18);
Ru(2)-Ru(1)-C(6), 108.78(19); Ru(1)-C(18)-Ru(2),
81.3(2); Ru(1)-C(17)-Ru(2), 81.1(3); C(6)-Ru(1)-Ru(2)-
C(16), 0.2; Cp(centroid)-Ru(1)-Ru(2)-Cp(centroid), 0.9;
Cp-Cp fold angle, 118.5.
a mixture of three geometrical isomers. However, the
patterns in the 1H NMR and IR spectra are very similar
to those of complex 9, which suggests that 13 has the
structure shown in Scheme 4. Attempts to isolate
individual isomers of 13 by means of column chroma-
tography were unsuccessful.
Con clu sion s
In summary, the dinuclear ruthenium complex {(η5-
C5H3)2(SiMe2)2}Ru2(CO)4 (1) is a precursor for the
synthesis of a variety of new dinuclear ruthenium
complexes, in which the bridging (η5-C5H3)2(SiMe2)2
ligand controls the geometry of the final product. This
influence is particularly pronounced in the reactions of
1 and phenylacetylenes which give (Scheme 4) the
unexpected complexes {(η5-C5H3)2(SiMe2)2}Ru2(CO){η2:
η4-µ2-C(Ph)C(Ph)C(Ph)C(Ph)} (9), {(η5-C5H3)2(SiMe2)2}-
Ru2(CO){η2:η4-µ2-C(dO)C(Ph)C(Ph)C(Ph)C(Ph)} (10), and
{(η5-C5H3)2(SiMe2)2}Ru2(CO){η2:η4-µ2-C(H)C(Ph)C(H)-
C(Ph)} (13) as major products. It is apparent that the
(η5-C5H3)2(SiMe2)2 ligand stabilizes these unique struc-
tural motifs, which were not reported for nonlinked or
monolinked dicyclopentadienyl Ru complexes. The steric
properties and rigidity of the bridging (η5-C5H3)2(SiMe2)2
ligand are presumably also responsible for the unusual
inertness of the bridging X- ligand in the complexes
[{(η5-C5H3)2(SiMe2)2}Ru2(CO)4(µ-X)]+TfO- (X ) Cl, Br,
I; 4a -c) toward AgTfO. We have also demonstrated the
(21) Errington, R. J . Advanced Practical Inorganic and Metalorganic
Chemistry, 1st ed.; Chapman & Hall: New York, 1997.
(22) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J . Organometallics 1996, 15, 1518.
(23) Perrin, D. D.; Armarego, W. L. F.; Perrin, D. R. Purification of
Laboratory Chemicals, 2nd ed.; Pergamon: New York, 1980.

626 Organometallics, Vol. 21, No. 4, 2002
Ovchinnikov et al.
Cl2): ν(CO) (cm-1) 1963 (w), 1932 (s), 1909 (w), 1740 (m). IR
(hexanes): ν(CO) (cm-1) 1976 (s), 1947 (s), 1917 (s), 1753 (s).
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)3(P P h 3) (2c).
A solution of 1 (30 mg, 0.053 mmol) in decane (1 mL) was
reacted with PPh3 (60 mg, 0.23 mmol) at 200 °C for 24 h, as
in the preparation of 2a . Two crystallizations of the resulting
orange oil from CH2Cl2-hexanes gave 2c (25 mg, 67%) as red
crystals. 1H NMR (400 MHz, CD2Cl2): δ 0.43 (s, 6 H, Si(CH3)),
0.53 (s, 6 H, Si(CH3)), 4.66 (d, J ) 2.4 Hz, 2 H, Cp-H), 4.91
(m, 1 H, Cp-H), 5.44 (d, J ) 2.1 Hz, 2 H, Cp-H), 5.72 (t, J )
2.1 Hz, 1 H, Cp-H), 7.53-7.78 (complex m, 15 H, P(C6H5)3).
31P{1H} NMR (161 MHz, CD2Cl2): δ 53 (s). IR (CH2Cl2): ν(CO)
(cm-1) 1973 (vs), 1948 (m), 1917 (vs), 1735 (m). IR (hexanes):
ν(CO) (cm-1) 1967 (vs), 1911 (vs).
obtained, using the same method as in the preparation of 4a .
1H NMR (400 MHz, CD2Cl2): δ 0.59 (s, 6 H, Si(CH3)), 0.66 (s,
6 H, Si(CH3)), 5.13 (t, J ) 2.0 Hz, 2 H, Cp H), 5.89 (d, J ) 2.0
Hz, 4 H, Cp H). IR (CH2Cl2): ν(CO) (cm-1) 2072 (vs), 2061 (m),
2025 (s).
Syn th esis of cis-{(η5-C5H3)2(SiMe2)2}(CO)4(µ-Sn Cl2) (5).
A solution of 1 (200.0 mg, 0.36 mmol) and SnCl2 (300 mg, 1.0
mmol) in THF (100 mL) was heated to reflux for 30 h. The
mixture was cooled to ambient temperature and chromato-
graphed on an alumina column (20 × 1 cm), first using hexanes
as the eluent and then a 1:5 (v/v) mixture of CH2Cl2 and
hexanes, which eluted a yellow band containing 5 (193 mg,
74%). 1H NMR (400 MHz, CDCl3): δ 0.36 (s, 6 H, Si(CH3)),
0.58 (s, 6 H, Si(CH3)), 5.58 (d, J ) 2.6 Hz, 4 H, Cp H), 5.64 (t,
J ) 2.6 Hz, 2 H, Cp H). 13C NMR (100 MHz, CDCl3): δ -0.52
(CH3), 0.73 (CH3), 88.09, 94.97, 95.26 (Cp), 196.95 (CO). IR
(hexanes): ν(CO) (cm-1) 2038 (s), 2023 (s), 1986 (vs), 1954 (w).
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(Cl)2 (3a ). A
solution of Cl2, prepared by passing gaseous chlorine through
CH2Cl2 (30 mL) for ∼1 min, was added dropwise to a solution
of complex 1 (120 mg, 0.22 mmol) in CH2Cl2 (60 mL). The
reaction was monitored by IR spectroscopy and stopped when
complex 1 was used up completely. The resulting solution was
then concentrated at reduced pressure to ∼5 mL, and hexanes
(20 mL) was added to give complex 3a (102 mg, 72%) as a
yellow solid. 1H NMR (400 MHz, CDCl3): δ 0.24 (s, 6 H,
Si(CH3)), 0.59 (s, 6 H, Si(CH3)), 5.34 (d, J ) 2.6 Hz, 4 H, Cp
Anal. Calcd for
C18H18Cl2O4Ru2Si2Sn: C, 28.97; H, 2.43.
Found: C, 28.95; H, 2.52.
Gen er a tion of [{(η5-C5H3)2(SiMe2)2}Ru 2(CO)4]2- (6) a n d
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4{µ-Ti(η5-C5H5)2}
(7). A solution of 1 (100.0 mg, 0.18 mmol) in THF (50 mL)
was added to Na/Hg (50 mg/2 mL) and THF (20 mL). After
the mixture was stirred for 20 h at ambient temperature, the
resulting yellow-green solution contained mainly [{(η5-C5H3)2-
(SiMe2)2}Ru2(CO)4]2- (6), as indicated by IR bands at 1928 (vs)
and 1808 (vs) cm-1. The solution was cannulated from the
amalgam layer and added to a solution of (η5-C5H5)2TiCl2 (37
mg, 0.15 mmol) in THF (30 mL). The resulting solution was
stirred for 1 h; volatiles were removed under reduced pressure,
and the residue was recrystallized from hexanes (20 mL) to
give 7 as pale yellow crystals (83 mg, 53%). 1H NMR (400 MHz,
CDCl3): δ 0.41 (s, 6 H, Si(CH3)), 0.61 (s, 6 H, Si(CH3)), 4.89
(br s, 10 H, Cp H), 5.21 (m, 4 H, Cp H), 5.42 (m, 2 H, Cp H).
IR (hexanes): ν(CO) (cm-1) 1938 (vs), 1876 (vs). Anal. Calcd
for C28H28O4Ru2Si2Ti2: C, 42.97; H, 3.61. Found: C, 42.03; H,
3.35. The extreme moisture sensitivity of 7 results in the
unsatisfactory combustion analysis.
H), 5.49 (t, J ) 2.6 Hz, 2 H, Cp H). IR (hexanes): ν(CO) (cm-1
)
2060 (vs), 2006 (vs). Anal. Calcd for C18H18Cl2O4Ru2Si2: C,
34.45; H, 2.89. Found: C, 34.87; H, 2.81.
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(Br )2 (3b).
When Br2 (∼5% solution in CH2Cl2) was reacted with complex
1 (120 mg, 0.22 mmol) in CH2Cl2 (60 mL), 3b (141 mg, 85%;
yellow solid) was obtained, using the same method as in the
preparation of 3a . 1H NMR (400 MHz, CDCl3): δ 0.21 (s, 6 H,
Si(CH3)), 0.60 (s, 6 H, Si(CH3)), 5.21 (d, J ) 2.6 Hz, 4 H, Cp
H), 5.42 (t, J ) 2.6 Hz, 2 H, Cp H). IR (hexanes): ν(CO) (cm-1
2058 (vs), 2004 (vs).
)
Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(I)2 (3c). When
I2 (∼5% solution in CH2Cl2) was reacted with complex 1 (120
mg, 0.22 mmol) in CH2Cl2 (60 mL), 3c (132 mg, 71%; yellow
solid) was obtained, using the same method as in the prepara-
tion of 3a . 1H NMR (400 MHz, CDCl3): δ 0.27 (s, 6 H, Si(CH3)),
0.56 (s, 6 H, Si(CH3)), 5.32 (d, J ) 2.6 Hz, 4 H, Cp H), 5.45 (t,
J ) 2.6 Hz, 2 H, Cp H). IR (hexanes): ν(CO) (cm-1) 2052 (vs),
2000 (vs).
Rea ction of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4 w ith Dip h en -
yla cetylen e. Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)2-
(µ-CO){η1:η1-µ2-C(P h )C(P h )} (8), {(η5-C5H3)2(SiMe2)2}Ru 2-
(CO){η2:η4-µ2-C(P h )C(P h )C(P h )C(P h )} (9), a n d {(η5-C5-
H 3)2(SiMe2)2}R u 2(CO){η2:η4-µ2-C(dO)C(P h )C(P h )C(P h )-
C(P h )} (10). The photolysis tube, equipped with a magnetic
stir bar, was charged with 1 (200 mg, 0.36 mmol) and
diphenylacetylene (140 mg, 0.79 mmol). Benzene (120 mL) was
added, and the reaction tube was then fit with the cold finger
(10 °C) and an oil bubbler. A slow flow of argon was maintained
through the solution using a Teflon cannula while it was
irradiated with stirring for 25 h. During this time the solution
turned from yellow to red. Solvent was removed under vacuum;
the resulting orange-brown residue was dissolved in hexanes
(10 mL) and chromatographed on an alumina column (20 × 3
cm) with hexanes-CH2Cl2 (5:1) as the eluent. A yellow band
was eluted and collected. Then, a pale orange band was eluted
with hexanes-CH2Cl2 (1:1). Finally, a red-orange band was
eluted with hexanes-CH2Cl2 (1:20). After vacuum removal of
the solvents from the above three eluates, the residues were
recrystallized from hexanes (eluates 1 and 3) or hexanes-
CH2Cl2 (1:1) (eluate 2) at -20 °C. From the first fraction, 123
mg (58%, based on 1) of orange crystalline 9 was obtained. 1H
NMR (400 MHz, C6D6): δ -0.62 (s, 6 H, Si(CH3)), 0.36 (s, 6 H,
Si(CH3)), 4.89 (d, J ) 2.0 Hz, 2 H, Cp H), 5.00 (d, J ) 2.0 Hz,
2 H, Cp H), 5.52 (t, J ) 2.0 Hz, 1 H, Cp H), 6.01 (t, J ) 2.0 Hz,
1 H, Cp H), 6.52 (t, J ) 7.6 Hz, 2 H, Ph), 6.72 (t, J ) 7.6 Hz,
2 H, Ph), 6.82 (d, J ) 7.6 Hz, 2 H, Ph), 6.87 (br s, 12 H, Ph),
7.09 (t, J ) 7.6 Hz, 2 H, Ph), 7.31 (d, J ) 7.6 Hz, 2 H, Ph),
7.46 (br s, 8 H, Ph). 13C NMR (100 MHz, C6D6): δ -4.60 (CH3),
8.13 (CH3), 82.49, 85.71, 90.39, 92.41, 93.71, 104.49 (Cp),
121.08, 126.01, 126.42, 126.51, 126.62 (br), 127.79, 131.65,
132.98 (br), 135.05, 139.88, 152.26, 158.90 (Ph, C-Ph), 208.54
Syn th esis of [{(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(µ-Cl)]+TfO-
(4a ). A yellow solution of 1 (175 mg, 0.31 mmol) and AgOTf
(89 mg, 0.35 mmol) in CH2Cl2 (30 mL) was titrated with a
solution of chlorine in CH2Cl2, prepared as described in the
synthesis of 3a . The reaction was followed by IR until the
starting complex 1 disappeared. The resulting red-brown
suspension was filtered through a short pad of Celite, and the
filtrate was layered with Et2O (100 mL) to precipitate 4a as
bright orange cubic crystals (199 mg, 85%). 1H NMR (400 MHz,
CD2Cl2): δ 0.65 (s, 6 H, Si(CH3)), 0.69 (s, 6 H, Si(CH3)), 5.08
(t, J ) 2.0 Hz, 2 H, Cp H), 5.93 (d, J ) 2.0 Hz, 4 H, Cp H). 13
C
NMR (100 MHz, CD2Cl2): δ -3.57 (CH3), 0.02 (CH3), 79.89,
94.76, 106.27 (Cp), 194.17, 204.95 (CO). IR (CH2Cl2): ν(CO)
(cm-1) 2077 (vs), 2069 (m), 2029 (s). Anal. Calcd for C19H18O7-
ClF3Ru2SSi2: C, 30.79; H, 2.45. Found: C, 30.68; H, 2.43.
Syn th esis of [{(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(µ-Br )]+TfO-
(4b). When Br2 (∼5% solution in CH2Cl2) was reacted with
complex 1 (175 mg, 0.31 mmol) and AgOTf (89 mg, 0.35 mmol)
in CH2Cl2 (30 mL), 4b (141 mg, 51%; orange solid) was
obtained, using the same method as in the preparation of 4a .
1H NMR (400 MHz, CD2Cl2): δ 0.60 (s, 6 H, Si(CH3)), 0.68 (s,
6 H, Si(CH3)), 5.11 (t, J ) 2.0 Hz, 2 H, Cp H), 5.91 (d, J ) 2.0
Hz, 4 H, Cp H). IR (CH2Cl2): ν(CO) (cm-1) 2074 (vs), 2065 (m),
2026 (s).
Syn th esis of [{(η5-C5H3)2(SiMe2)2}Ru 2(CO)4(µ-I)]+TfO-
(4c). When I2 (∼5% solution in CH2Cl2) was reacted with
complex 1 (175 mg, 0.31 mmol) and AgOTf (89 mg, 0.35 mmol)
in CH2Cl2 (30 mL), 4c (191 mg, 78%; orange solid) was

An Ru Complex with a Dicyclopentadienyl Ligand
Organometallics, Vol. 21, No. 4, 2002 627
(CO). IR (hexanes): ν(CO) (cm-1) 1969 (vs). Anal. Calcd for
C
Cr ysta llogr a p h ic Str u ctu r a l Deter m in a tion of 1. A
yellow crystal of 1 with approximate dimensions 0.38 ×
0.34 × 0.32 mm was selected under oil under ambient
conditions and attached to the tip of a glass capillary. The
crystal was mounted in a stream of cold nitrogen at 183(2) K
and centered in the X-ray beam by using a video camera. The
crystal evaluation and data collection were performed on a
Bruker CCD-1000 diffractometer with Mo KR (λ ) 0.710 73
Å) radiation and diffractometer to crystal distance of 5.08 cm.
The initial cell constants were obtained from three series of ω
scans at different starting angles. Each series consisted of 20
frames collected at intervals of 0.3° in a 6° range about ω with
an exposure time of 10 s per frame. A total of 93 reflections
was obtained. Reflections were successfully indexed by an
automated indexing routine in the SMART program. The final
cell constants were calculated from a set of 5689 strong
reflections from the actual data collection. The data were
collected by using the hemisphere data collection routine.
Reciprocal space was surveyed to the extent of 1.8 hemispheres
to a resolution of 0.80 Å. A total of 8075 data were harvested
by collecting three sets of frames with 0.3° scans in ω with an
exposure time of 20 s per frame. These highly redundant data
sets were corrected for Lorentz and polarization effects. The
absorption correction was based on fitting a function to the
empirical transmission surface as sampled by multiple equiva-
lent measurements.24
43H38ORu2Si2‚1/2C5H12: C, 63.17; H, 5.13. Found: C, 63.08;
H, 5.16. From the second fraction, 27 mg (12%, based on 1) of
1
orange crystalline 8 was obtained. H NMR (400 MHz, C6D6):
δ 0.12 (s, 3 H, Si(CH3)), 0.23 (s, 3 H, Si(CH3)), 0.26 (s, 3 H,
Si(CH3)), 0.21 (s, 3 H, Si(CH3)), 4.41 (m, 2 H, Cp H), 4.89 (m,
2 H, Cp H), 5.23 (m, 2 H, Cp H), 6.56 (m, 4 H, Ph), 6.79 (m, 2
H, Ph), 6.91 (m, 4 H, Ph). IR (hexanes): ν(CO) (cm-1) 1983
(vs), 1935 (m), 1753 (m). Anal. Calcd for C31H28O3Ru2Si2: C,
52.67; H, 3.99. Found: C, 53.01; H, 3.83. From the third
fraction, 41 mg (21%, based on 1) of red crystalline 10 was
obtained. 1H NMR (400 MHz, CDCl3): δ -1.00 (s, 3 H,
Si(CH3)), 0.31 (s, 3 H, Si(CH3)), 0.36 (s, 3 H, Si(CH3)), 0.57 (s,
3 H, Si(CH3)), 4.80 (m, 1 H, Cp H), 5.18 (m, 1 H, Cp H), 5.43
(m, 1 H, Cp H), 5.89 (t, J ) 2.2 Hz, 1 H, Cp H), 6.02 (m, 1 H,
Cp H), 6.89 (t, J ) 2.2 Hz, 1 H, Cp H), 6.40-7.15 (complex
array of signals, 19 H, Ph), 7.86 (d, J ) 8.4 Hz, 1 H, Ph). 13C
NMR (100 MHz, C6D6): δ -4.42, -1.22, 6.76, 8.27 (CH3), 63.21,
81.53, 86.78, 89.02, 89.06, 93.87, 96.93, 98.71, 98.78, 104.99
(Cp; 10 peaks), 110.19, 116.27, 117.20, 125.90, 125.95, 126.00,
126.08, 126.49, 126.70, 126.84, 127.36, 127.72, 131.33, 131.54,
132.47, 134.25, 134.99, 135.20, 139.88, 140.74, 141.95, 155.11,
175.58 (Ph, C-Ph; 23 out of 24 peaks), 203.10, 211.40 (CO,
C(dO)-Ph). IR (hexanes): ν(CO) (cm-1) 1973 (vs), 1601 (w).
Anal. Calcd for C44H38O2Ru2Si2‚1/2CH2Cl2: C, 59.42; H, 4.37.
Found: C, 59.19; H, 4.59.
Rea ction of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)4 w ith P h en -
yla cetylen e. Syn th esis of {(η5-C5H3)2(SiMe2)2}Ru 2(CO)3(µ-
CdCHP h ) (12) a n d {(η5-C5H3)2(SiMe2)2}Ru 2(CO){η2:η4-µ2-
C(H)C(P h )C(H)C(P h )} (Mixtu r e of Isom er s) (13). The
photolysis tube, equipped with a magnetic stir bar, was
charged with 1 (200 mg, 0.36 mmol) and phenylacetylene (160
mg, 1.23 mmol). Benzene (120 mL) was added, and the reaction
tube was then fitted with the cold finger (10 °C) and an oil
bubbler. A slow flow of argon was maintained through the
solution using a Teflon cannula while it was irradiated with
stirring for 30 h. During this time the solution turned from
yellow to red. Solvent was removed under vacuum; the
resulting orange-brown residue was redissolved in hexanes (10
mL) and chromatographed on an alumina column (20 × 3 cm)
with hexanes-CH2Cl2 (5:1) as the eluent. A yellow band was
eluted and collected. Then, a pale orange band was eluted with
hexanes-CH2Cl2 (1:5). After vacuum removal of the solvents
from the above two eluates, the residues were recrystallized
from hexanes at -20 °C. From the first fraction, 17 mg (8%,
based on 1) of the orange oily solid 13 was obtained as a
mixture of three isomers. The 1H NMR (400 MHz, C6D6)
spectrum displays a complicated pattern of signals due to the
presence of three unique geometrical isomers (see Discussion).
IR (hexanes): ν(CO) (cm-1) 1977 (w), 1968 (vs). From the
second fraction, 107 mg (72%, based on 1) of yellow crystalline
Systematic absences in the diffraction data were consistent
with space groups Cc and C2/c, but only the latter centrosym-
metric space group C2/c yielded chemically reasonable and
computationally stable results in refinement.25 A successful
solution by direct methods provided most non-hydrogen atoms
from the E map. The remaining non-hydrogen atoms were
located in an alternating series of least-squares cycles and
difference Fourier maps. All non-hydrogen atoms were refined
with anisotropic displacement coefficients. All hydrogen atoms
were included in the structure factor calculation at idealized
positions and were allowed to ride on the neighboring atoms
with relative isotropic displacement coefficients. Each molecule
occupies a crystallographic 2-fold axis. The final least-squares
refinement of 120 parameters against 2063 data resulted in
residuals R (based on F2 for I g 2σ) and Rw (based on F2 for
all data) of 0.0174 and 0.0457, respectively. The final difference
Fourier map was featureless.
X-ray data for complexes 2a , 3c, 5, 9, 10, and 12 were
obtained in a similar manner, unless stated otherwise in the
Supporting Information.
Ack n ow led gm en t. This work was supported by the
National Science Foundation through Grant No. CHE-
9816342.
1
12 was obtained. H NMR (400 MHz, CD2Cl2): δ 0.40 (s, 3 H,
Su p p or tin g In for m a tion Ava ila ble: Tables giving crys-
tallographic data for 1, 2a , 3c, 5, 9, 10, and 12, including
atomic coordinates, bond lengths and angles, and anisotropic
displacement parameters. This material is available free of
charge via the Internet at http://pubs.acs.org.
Si(CH3)), 0.49 (s, 3 H, Si(CH3)), 0.55 (s, 3 H, Si(CH3)), 0.68 (s,
3 H, Si(CH3)), 5.59 (m, 1 H, Cp H), 5.61 (m, 1 H, Cp H), 5.70
(m, 1 H, Cp H), 5.73 (m, 1 H, Cp H), 6.23 (m, 1 H, Cp H), 6.37
(m, 1 H, Cp H), 7.10 (m, 1 H, Ph), 7.30 (m, 2 H, Ph), 7.61 (s,
1 H, CdCPhH), 7.62 (m, 2 H, Ph). 13C NMR (100 MHz,
CD2Cl2): δ -3.27 (CH3), -3.00 (CH3), 2.64 (2 CH3), 91.81,
92.07, 93.03, 94.21, 94.71, 95.50, 107.98, 108.03, 109.48,
110.125 (Cp), 125.44, 128.47, 138.68, 141.00 (Ph), 201.02,
202.11, 241.36 (CO), 247.42 (CdCPhH). IR (hexanes): ν(CO)
OM010674Y
(24) Blessing, R. H. Acta Crystallogr. 1995, A51, 33-38.
(25) All software and sources of the scattering factors are contained
in the SHELXTL (version 5.1) program library (G. Sheldrick, Bruker
Analytical X-ray Systems, Madison, WI).
(cm-1) 2008 (vs), 1982 (m), 1819 (m). Anal. Calcd for C25H24
O3Ru2Si2: C, 47.60; H, 3.84. Found: C, 47.47; H, 4.12.
-