Synthesis, structure, and reactivity of neutral hydrogen-substituted ruthenium silylene and germylene complexes

Article abstract of DOI:10.1021/om900348m

Reaction of Cp(ⁱPr₂MeP)RuCl (1) with 0.5 equiv of Mg(CH₂Ph)₂(THF)₂ afforded the benzyl complex Cp(ⁱPr₂MeP)Ru(η³ -CH₂Ph) (2). Complex 2 readily reacted with

Full text of DOI:10.1021/om900348m

5082 Organometallics 2009, 28, 5082–5089
DOI: 10.1021/om900348m
Synthesis, Structure, and Reactivity of Neutral Hydrogen-Substituted
Ruthenium Silylene and Germylene Complexes
Paul G. Hayes,† Rory Waterman,‡ Paul B. Glaser,§ and T. Don Tilley*
Department of Chemistry, University of California, Berkeley, California 94720-1460. †Current address:
Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada, T1K
3M4. ‡ Current address: Department of Chemistry, University of Vermont, Burlington, Vermont 05405.
§Current address: General Electric Global Research, Niskayuna, NY 12309.
Received May 3, 2009
Reaction of Cp*(iPr2MeP)RuCl (1) with 0.5 equiv of Mg(CH2Ph)2(THF)2 afforded the benzyl
complex Cp*(iPr2MeP)Ru(η3-CH2Ph) (2). Complex 2 readily reacted with primary silanes H3SiR
(R = trip, dmp, MesF; trip = 2,4,6-iPr3-C6H2, dmp = 2,6-Mes2-C6H3, MesF = 2,4,6-(CF3)3-C6H2)
to liberate toluene and afford hydrogen-substituted silylene complexes Cp*(iPr2MeP)(H)RudSiH(R)
[R = trip, 3; dmp, 4; MesF, 5]. Complexes 3-5 exhibit characteristic SiH 1H NMR resonances downfield
of 8 ppm and very small 2JSiH coupling constants (8-10 Hz). The solid state structures of complexes 3 and
˚
5 feature short Ru-Si distances of 2.205(1) and 2.1806(9) A, respectively, and planar silicon centers. In
addition, the silylene complex Cp*(iPr2MeP)(H)RudSiPh(trip) (6) and the unusual, chlorine-substituted
species Cp*(iPr2MeP)(H)RudSiCl(R) [R = trip, 7; dmp, 8] were prepared. Hydrogen-substituted
ruthenium germylene complex Cp*(iPr2MeP)(H)RudGeH(trip) (9) was prepared similarly by reaction
of 2 with tripGeH3. Complex 9 is the first structurally characterized ruthernium germylene complex and
˚
has a remarkably short Ru-Ge distance of 2.2821(6) A. Complex 9 adds H2O across its RudGe bond to
give Cp*(iPr2MeP)(H)2RuGeH(OH)(trip) (10).
Introduction
hydrogen-substituted ruthenium complex [Cp*(iPr3P)(H)2-
RudSiHPh Et2O][B(C6F5)4], which efficiently catalyzes the
3
Transition metal silylene complexes (LnMdSiRR0) that
formally possess a metal-silicon double bond represent
unsaturated silicon compounds featuring chemical and phy-
sical properties of fundamental interest.1 These complexes
offer interesting comparisons to the better known carbene
complexes and have been proposed to play important roles
as intermediates in a variety of catalytic reactions such as the
synthesis of methylchlorosilanes by the Direct Process,2 the
redistribution of substituents at silicon,3 and the transfer of
silylene fragments to an unsaturated carbon-carbon bond.4
It was not until recently, however, that direct evidence for
participation of a metal silylene complex in a catalytic
transformation was obtained. This catalysis involves the
hydrosilylation of alkenes.5 Key characteristics of this reac-
tion include the requirement for primary silane substrates, a
compatibility with highly substituted alkenes, exclusive anti-
Markovnikov regiochemistry, and cis stereochemistry for
the Si-H addition. These features are inconsistent with the
well-known Chalk-Harrod6 and Lewis acid7 mechanisms
for alkene hydrosilylation, and mechanistic5,8 and theore-
tical9 investigations are consistent with a catalytic cycle
that features the direct addition of an Si-H bond to
the alkene. In this cycle, a silylene unit is transferred
from RSiH3 to the metal center (silylene extrusion) via
two Si-H bond activations, an Si-H oxidative
addition followed by an R-hydrogen migration to afford
*To whom correspondence may be addressed. Tel: 510-642-8939.
E-mail: tdtilley@berkeley.edu.
(1) Waterman, R.; Hayes, P. G.; Tilley, T. D. Acc. Chem. Res. 2007,
40, 712–719.
(5) Glaser, P. B.; Tilley, T. D. J. Am. Chem. Soc. 2003, 125, 13640–
13641.
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(b) Seitz, F.; Wrighton, M. S. Angew. Chem., Int. Ed. 1988, 27, 289–291. (c)
Duckett, S. B.; Perutz, R. N. Organometallics 1992, 11, 90–98. (d) Sakaki,
S.; Sumimato, M.; Fukuhara, M.; Sugimoto, M.; Fujimoto, H.; Matsuzaki, S.
Organometallics 2002, 21, 3788–3802.
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1936–1940. (b) Song, Y. S.; Yoo, B. R.; Lee, G. H.; Jung, I. N. Organome-
tallics 1999, 18, 3109–3115. (c) Lambert, J. B.; Zhao, Y.; Wu, H. W. J. Org.
Chem. 1999, 64, 2729–2736. (d) Schmeltzer, J. M.; Porter, L. A.; Stewart, M.
P.; Buriak, J. M. Langmuir 2002, 18, 2971–2974.
(2) (a) Lewis, K. M., Rethwisch, D. G., Eds. Catalyzed Direct
Reactions of Silicon; Elsevier: Amsterdam, 1993. (b) Pachaly, B.; Weis, J.
In Organosilicon Chemistry III: From Molecules to Materials, Munich
Silicon Days; 1996; Wiley & Sons: New York, 1998; p 478. (c) Brook, M. A.
Silicon in Organic, Organometallic and Polymer Chemistry; Wiley: New
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Compounds; Rappoport, Z., Apeloig, Y., Eds.; Wiley: Chichester, UK,
1998; Pt 2, p 1581.
(3) (a) Curtis, M. D.; Epstein, P. S. Adv. Organomet. Chem. 1981, 19,
213–255. (b) Kumada, M. J. J. Organomet. Chem. 1975, 100, 127–138.
(4) Some recent examples include: (a) Franz, A. K.; Woerpel, K. A. J.
Am. Chem. Soc. 1999, 121, 949–957. (b) Palmer, W. S.; Woerpel, K. A.
Organometallics 2001, 20, 3691–3697. (c) Cirakovic, J.; Driver, T. G.;
Woerpel, K. A. J. Am. Chem. Soc. 2002, 124, 9370–9371.
(8) Hayes, P. G.; Beddie, C.; Hall, M. B.; Waterman, R.; Tilley, T. D.
J. Am. Chem. Soc. 2006, 128, 428–429.
(9) (a) Beddie, C.; Hall, M. B. J. Am. Chem. Soc. 2004, 126, 13564–
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2009 American Chemical Society
pubs.acs.org/Organometallics
Published on Web 08/07/2009

Article
Organometallics, Vol. 28, No. 17, 2009 5083
Scheme 1
[Cp*(iPr3P)(H)2RudSiHR][B(C6F5)4]. Direct addition of
the sp2 Si-H bond to an alkene (e.g., CH2dCHR0) then
gives a disubstituted silylene complex, [Cp*(iPr3P)(H)2-
RudSi(CH2CH2R0)(R)][B(C6F5)4]. Migration of hydrogen
from the metal center to silicon and reductive elimination
of the new silane molecule complete the catalytic cycle
(Scheme 1).5,8-10
Chart 1
Although the related osmium complex [Cp*(iPr3P)(H)2-
OsdSiH(trip)][B(C6F5)4] (trip = 2,4,6-iPr3C6H2) is not cat-
alytically active toward the hydrosilylation of alkenes, stoi-
chiometric alkene insertion into the Si-H bond is
exceedingly rapid, even at -78 °C.5 Interestingly, neutral
analogues of this osmium silylene complex, conveniently
prepared via reaction of Cp*(iPr3P)OsCH2Ph with primary
silanes, do not react with alkenes even at elevated tempera-
tures.8 Computational studies indicate that the much lower
reactivity of these Cp*(iPr3P)(H)OsdSiH(R) complexes to-
ward alkenes is related to their higher degree of covalent
double-bond character and a small localization of positive
charge onto silicon (second resonance structure of Chart 1).8
Nonetheless, neutral, hydrogen-substituted silylene com-
plexes are expected to display a rich reaction chemistry that
is distinct from that of cationic analogues.5,8,11 In an attempt
to further probe structure, bonding, and reactivity of
MdSiH(R) and related MdGeH(R) neutral complexes, a
series of ruthenium complexes have been prepared via ex-
trusion reactions promoted by the benzyl complex Cp*-
(iPr2MeP)Ru(η3-CH2Ph) (2).
Results and Discussion
Synthesis of the Ruthenium Benzyl Complex Cp*-
(iPr2MeP)Ru(η3-CH2Ph) (2). The initial objective of this
study was to develop a general silane activation process
leading to silylene-hydride complexes. In this regard, allyl11h
and benzyl complexes8,11g may serve as convenient starting
materials because facile η3-to-η1 transformations of the
ligand provide an empty coordination site that may be used
for activation of an Si-H bond. Subsequent C-H reductive
elimination then produces an unsaturated M-SiHRR0 inter-
mediate, which can undergo R-migration to provide the final
silylene complex. This process was envisioned as a general
route to neutral ruthenium silylene complexes (Scheme 2).
Unlike the osmium analogue Cp*(iPr3P)OsBr, reaction of
Cp*(iPr3P)RuCl with standard benzylating reagents (including
Mg(CH2Ph)2(THF)2, PhCH2MgCl, and KCH2Ph) did not
afford the desired benzyl complex Cp*(iPr3P)RuCH2Ph. Upon
combining the reactants in benzene-d6 solution, there was an
immediate change in color from dark purple to orange with
concomitant disappearance of 1H and 31P NMR signals attrib-
uted to the starting materials. The observation of 1 equiv of
toluene as a product suggests that Cp*(iPr3P)RuCH2Ph is
generated in these reactions, but it decomposes rapidly under
(10) Brunner, H. Angew. Chem., Int. Ed. 2004, 43, 2749–2750.
(11) (a) Sakaba, H.; Hirata, T.; Kabuto, C.; Kabuto, K. Organome-
tallics 2006, 25, 5145–5150. (b) Watanabe, T.; Hashimoto, H.; Tobita, H. J.
Am. Chem. Soc. 2007, 129, 11338–11339. (c) Watanabe, T.; Hashimoto, H.;
Tobita, H. J. Am. Chem. Soc. 2006, 128, 2176–2177. (d) Ochiai, M.;
Hashimoto, H.; Tobita, H. Angew. Chem., Int. Ed. 2007, 46, 8192–8194.
(e) Simmons, R. S.; Gallucci, J. C.; Tessier, C. A.; Youngs, W. J. J.
Organomet. Chem. 2002, 654, 224–228. (f) Watanabe, T.; Hashimoto, H.;
Tobita, H. Angew. Chem., Int. Ed. 2004, 43, 218–221. (g) Mork, B. V.;
Tilley, T. D.; Schultz, A. J.; Cowan, J. A. J. Am. Chem. Soc. 2004, 126,
10428–10440. (h) Feldman, J. D.; Peters, J. D.; Tilley, T. D. J. Am. Chem.
Soc. 2002, 21, 4065–4075. (i) Glaser, P. B.; Tilley, T. D. Organometallics
2004, 23, 5799–5812. (j) Rankin, M. A.; MacLean, D. F.; Schatte, G.;
McDonald, R.; Stradiotto, M. J. Am. Chem. Soc. 2007, 129, 15855–15864.
(k) Ochiai, M.; Hashimoto, H.; Tobita, H. Dalton Trans. 2009, 1812–1814.
(l) Hashimoto, H.; Ochiai, M.; Tobita, H. J. Organomet. Chem. 2007, 692,
36–43.

5084 Organometallics, Vol. 28, No. 17, 2009
Hayes et al.
Scheme 2
Figure 1. Molecular structure of complex 2 with thermal ellip-
soids drawn at the 30% probability level; hydrogen atoms are
˚
omitted for clarity. Selected distances (A) and angles (deg): Ru-
C(1) 2.156(4), Ru-C(11) 2.187(4), Ru-C(16) 2.330(4), Ru-P
2.222(4), Ru-Ccentroid 1.862(5), C(1)-C(11) 1.424(6), C(11)-
C(12) 1.433(5), C(12)-C(13) 1.365(5), C(13)-C(14) 1.411(6),
C(14)-C(15) 1.357(5), C(15)-C(16) 1.434(5), C(16)-C(11)
1.443(5), C(1)-Ru-P 89.42(11), C(11)-Ru-P 105.01 (11),
C(16)-Ru-P 94.72(9), P-Ru-Ccentroid 126.6(8), C(1)-
C(11)-C(16) 119.1(3), C(1)-Ru-C(16) 66.74(13), C(1)-Ru-
C(11) 38.26(15).
observed, 1 equiv of toluene quantitatively formed. In the 1H
NMR spectrum of the intractable product mixtures, multiple
hydride resonances and inequivalent iPr and mesityl methyl
groups suggest that intramolecular C-H activation, rather
than the expected R-hydrogen migration from the putative
silyl intermediate, Cp*(iPr2MeP)RuSiH2Ph, occurred.12
In light of the results described above, silanes with more
sterically demanding substituents were examined under the
hypothesis that these substrates might lead to more stable
ruthenium-silylene complexes. Addition of benzene solutions
of 2 to sterically hindered primary silanes for periods of 5 min
to 24 h cleanly generated the orange-red silylene complexes
Cp*(iPr2MeP)(H)RudSiH(R) (R = trip, 3; dmp, 4; trip =
2,4,6-iPr3-C6H2; dmp = 2,6-mesitylphenyl) in 43% and 79%
yield, respectively (eq 1). Repeated attempts to observe the 29Si
NMR signal for complex 3 (including direct detection and 2-D
HMBC experiments (ambient and variable temperature)) were
unsuccessful. This may be due to rapid exchange of the RuH
and SiH hydrogens, via the unsaturated species Cp*-
(iPr2MeP)RuSiH2R, on the NMR time scale. Correspond-
ingly, the diagnostic SiH and RuH resonances for complex 3,
which are observed at δ 9.41 and -13.5, respectively, are broad
and featureless. The more bulky complex 4, however, exhibits
a well-defined 29Si resonance at δ 204 and a sharp downfield
the reaction conditions. Though the NMR spectra of the
decomposition product did not provide a definitive formulation,
predominant resonances at δ52.9 in the 31P NMR spectrum and
a new Cp* signal at δ 2.02 in the 1H NMR spectrum implied the
generation of a relatively pure compound. The loss of symmetry
i
for the Pr methyl groups and the presence of a characteristic
doublet at δ -11.9 in the 1H NMR spectrum are consistent with
two C-H activation events, leading to a metal hydride complex
similar to Cp*[iPr2P(η2-MeCdCH2)]OsH, which was prepared
by deprotonation of {Cp*[iPr2P(η2-MeCdCH2)]OsH2}[B-
(C6F5)4] with KN(SiMe3)2.11i Unfortunately all attempts to
isolate the ruthenium product led to intractable mixtures, and
further characterization was not possible. Similarly, efforts to
prepare silylene complexes by reaction of silanes such as
tripSiH3 and MesFSiH3 with putative Cp*(iPr3P)RuCH2Ph,
generated in situ at low temperatures, were unsuccessful.
On the basis of the results described above, it was thought
that a more stable benzyl complex (i.e., one less prone to
toluene elimination) might be obtained by use of a less
sterically demanding phosphine ligand with fewer iPr
i
groups. Reaction of Pr2MeP with [Cp*RuCl]4 in CH2Cl2
gave analytically pure, dark blue crystals of Cp*-
(iPr2MeP)RuCl (1) in 85% yield. Treatment of 1 with
0.5 equiv of Mg(CH2Ph)2(THF)2 cleanly afforded the corre-
sponding benzyl complex Cp*(iPr2MeP)RuCH2Ph (2) as
analytically pure red crystals in 73% yield. Though complex
2 exhibits slight thermal sensitivity (t1/2 ≈ 24 h in benzene-d6
solution at ambient temperature), it is indefinitely stable as a
solid when stored under an inert atmosphere at -35 °C. The
1H NMR spectrum of 2 exhibited distinct resonances at δ
6.89, 5.19, and 1.68, consistent with an η3 structure that is
static on the NMR time scale. X-ray quality single crystals of
2 were grown from cold hexanes solution. The solid state
structure, shown in Figure 1, confirms the presence of an η3-
benzyl ligand with Ru-C bond distances of 2.156(4),
SiH 1H NMR resonance at δ 8.00 (3JHP = 11.9 Hz, 1JHSi
=
151 Hz). Similar to the osmium anologue,8 ruthenium silylene
complex 4 displayed a low 2JSiH value of 8.6 Hz, which implies
significant metal-silicon double-bond character and minimal
interaction between the ruthenium hydride and silicon atom.
The upfield metal hydride resonance at δ -14.4 corroborates
this assertion.
˚
2.187(4), and 2.330(4) A.
Synthesis of H-Substituted Ruthenium Silylene Complexes.
Treatment of 2 with either PhSiH3 or MesSiH3 (Mes = 2,4,6-
Me3-C6H2) in benzene solution resulted in an immediate
color change from red to orange, and complete consump-
Crystals of 3 suitable for an X-ray diffraction study were
grown from a concentrated hexanes solution cooled to
-35 °C for 24 h. Complex 3 is isostructural with the osmium
1
tion of the starting material was observed by 31P and H
NMR spectroscopy. Though several different products were
(12) See Supporting Information for additional details.

Article
Organometallics, Vol. 28, No. 17, 2009 5085
Figure 2. Molecular structure of silylene complex 3 with ther-
mal ellipsoids at the 30% probability level. Hydrogen atoms are
omitted for clarity except for H(1) and H(2), which were located
Figure 3. Molecular structure of silylene complex 5 with ther-
mal ellipsoids at the 30% probability level. Hydrogen atoms are
omitted for clarity except for H(2), which was located on Si.
˚
on Ru and Si, respectively. Selected distances (A) and angles
˚
Selected distances (A) and angles (deg): Ru-Si 2.1806(9), Ru-
(deg): Ru-Si 2.205(1), Ru-Ccentroid 1.892(4), Si-C(61)
1.888(4), Ru-P 2.272(1), C(61)-Si-Ru 129.2(1), Ru-Si-
H(2) 127.8(1), P-Ru-Si 93.38(4), C(61)-Si-H(2) 102.4(1),
P-Ru-Ccentroid 132.1(2).
Ccentroid 1.886(3), Si-C(61) 1.947(3), Ru-P 2.2849(8), C(61)-
Si-Ru 128.9(3), Ru-Si-H(2) 133.7(1), P-Ru-Si 90.99(3),
C(61)-Si-H(2) 97.4(1), P-Ru-Ccentroid 132.3(2).
The rapid reaction of H3SiMesF with 2 proceeded to
complete conversion to the corresponding silylene complex
5 within several minutes. Complex 5 can be isolated from
alkane solvents as an analytically pure ruby red solid in 81%
yield. As seen for 3 and 4, the 1H NMR spectrum of 5 exhibits
a diagnostic multiplet attributed to RuH at δ -13.4. How-
ever, no resonance was observed for the silylene hydrogen or
the 29Si resonance, which is likely due to significant broad-
ening of the signal caused by coupling to nine 19F nuclei of
the aryl substituent.16
analogue,8 featuring a short RudSi bond (Ru-Si = 2.205(1)
A). This compares well with the base-free silylene complexes
˚
13
˚
[Cp*(Me3P)2RudSiMe2][B(C6F5)4] (Ru-Si = 2.238(3) A)
and Cp*(CO)(H)RudSiH[C(SiMe3)3] (Ru-Si = 2.220(2)
A)11d and base-stabilized primary silylene examples [Cp*( μ-P,
˚
˚
N-L)(H)2RuSiHPh][SO3CF3] (Ru-Si=2.262(2) A) and Cp*-
˚
( μ-P,N-L)(H)2RuSiHPh (Ru-Si = 2.2635(5) A; L=2-NMe2-
3-PiPr2-indenide), recently reported by Stradiotto and co-work-
ers.11j Other notable features of the solid state structure include a
planar silicon center (summation of angles at Si = 359.4°) and a
H(1)-Ru-Si-H(2) dihedral angle of -48.8°, indicating an
approximately cis geometry (Figure 2). Both H(1) on ruthenium
and H(2) on silicon were located in the Fourier difference map
and anisotropically refined.
The electron-withdrawing effect of the fluorinated sub-
stituent at silicon results in a small but statistically relevant
˚
contraction of the Ru-Si bond to 2.1806(9) A. To the best of
our knowledge, this represents the shortest Ru-Si distance
yet reported. This short Ru-Si bond appears to reflect a
higher bond order between ruthenium and silicon and re-
duced silicenium character for the silylene ligand (Figure 3).
Consistent with this, a benzene-d6 solution of complex 5
failed to react with 1 equiv of ethylene, 1-hexene, or
tBuCHdCH2 upon heating to reflux for 96 h.
Neutral silylene 3 is exceedingly thermally sensitive, and as a
result, no reaction with alkenes, such as ethylene, 1-hexene, or
tBuCHdCH2, was observed prior to decomposition to a
mixture of unidentified products (benzene-d6 solution). In
contrast, the steric bulk of the silicon substituent in 4 renders
the complex indefinitely stable in aliphatic and aromatic
solvents, although no reaction was observed upon heating
toluene solutions of 4 and 1 equiv of various alkenes, such as
ethylene, 1-hexene, or tBuCHdCH2, to reflux for more than 96
h. Terphenyl substituents are common in the preparation of
reactive main group species due to the kinetic stability im-
parted by this bulky fragment.14 The inertness of 4 is pre-
sumably a reflection of the steric bulk of the dmp-substituted
silylene functionality. This notion is supported by the observa-
tion that the synthesis of 4 requires approximately 50 times
longer to reach completion than the synthesis of 3.
In an effort to obtain a more sterically accessible ruthe-
nium silylene ligand, while retaining the thermal stability
associated with 4, the partially fluorinated silane H3SiMesF
(MesF = 2,4,6-(CF3)3-C6H2)15 was prepared. For this silane,
the lack of accessible, benzylic C-H bonds was expected to
prevent the metalation pathway believed to be operative for
the mesityl-substituted silane. In addition, it seemed that the
electron-withdrawing -MesF group might impart consider-
able electrophilicity to a silylene silicon center and thereby
promote alkene insertions into the Si-H bond.
Synthesis of Cl-Substituted Ruthenium Silylene Complexes.
Complex 2 also participates in silylene extrusion processes
with more sterically demanding, secondary silanes. For
example, the asymmetrically substituted silylene Cp*-
(iPr2MeP)(H)RudSiPh(trip) (6) was readily isolated as an
orange powder in 54% yield from reaction of benzene
solutions of 2 with H2SiPh(trip).
The results described above indicate that silane additions
to 2 readily provide convenient, efficient pathways to ruthe-
nium silylene complexes of the type Cp*(iPr2MeP)-
(H)RudSiRR0. To further investigate the generality of this
method, attempts were made to obtain ruthenium silylene
complexes with potentially reactive substituents. Along these
lines, it is worth noting that a chloro-substituted silylene
complex of molybdenum provided a route to the first silylyne
complex, [Cp*(dmpe)HMotSiMes][B(C6F5)4].17 Reaction
of 1 equiv of the chlorosilanes tripSiH2Cl and dmpSiH2Cl
with complex 2 in toluene at room temperature afforded the
corresponding silylene complexes Cp*(iPr2MeP)(H)-
RudSiCl(R) (R = trip (7), dmp (8)) as dark pink solids in
(16) Significant broadening and complex coupling patterns were also
observed for the OsH and SiH resonances in the 1H NMR spectrum of
Cp*(iPr3P)(H)OsdSiH(MesF): Unpublished results. Hayes, P. G.;
Tilley, T. D.
(13) Grumbine, S. K.; Tilley, T. D. J. Am. Chem. Soc. 1994, 116,
5495–5496.
(14) Rivard, E.; Power, P. P. Inorg. Chem. 2007, 46, 10047–10064.
(15) Smit, C. N.; Bickelhaupt, F. Organometallics 1987, 6, 1156–1163.
(17) Mork, B. V.; Tilley, T. D. Angew. Chem., Int. Ed. 2003, 42, 357–
360.

5086 Organometallics, Vol. 28, No. 17, 2009
Hayes et al.
62% and 59% yield, respectively. Interestingly, replacement
of hydrogen for chlorine at silicon does not cause a sub-
stantial shift in the 29Si NMR resonances for 7 and 8, which
are observed at δ 222 and 205, respectively. Attempts to grow
high-quality crystals have been unsuccessful; however, a
single-crystal diffraction study on a poorly diffracting crystal
of 7 provided a structure consistent with the formulation
established spectroscopically.18 Efforts to utilize the Cl
group of complexes 7 and 8 for further derivatization reac-
tions are currently in progress.
Figure 4. Molecular structure of germylene complex 9 with
thermal ellipsoids at the 30% probability level. Hydrogen atoms
are omitted for clarity except for H(1) and H(2), which were
Synthesis of H-Substituted Ruthenium Germylene Com-
plexes. On the basis of the success of 2 as a suitable precursor
for the synthesis of various silylene complexes, this strategy
was investigated to prepare previously unknown, H-substi-
tuted germylene complexes. Thus, reaction of 2 with trip-
GeH3 in benzene gave the hydrogen-substituted germylene
complex Cp*(iPr2MeP)(H)RudGeH(trip) (9) as an analyti-
cally pure orange solid in 67% yield. The identity of complex
9 is supported by 1H NMR resonances at δ 12.4 (GeH) and -
12.8 (RuH), but the lack of a useful NMR-active nucleus
(73Ge: I = 9/2, 7.7%) renders it difficult to obtain conclusive
solution state information regarding the nature of the ruthe-
nium-germanium interaction. Fortunately, high-quality or-
ange crystalline blocks were grown from cold pentane
solutions of 9. The most remarkable element of the solid
state structure is the extremely short ruthenium-germanium
˚
located on Ru and Ge, respectively. Selected distances (A) and
angles (deg): Ru-Ge 2.2821(6), Ru-Ccentroid 1.885(5), Ge-
C(61) 1.974(3), Ru-P 2.272(2), C(61)-Ge-Ru 129.3(1), Ru-
Ge-H(2) 130.8, P-Ru-Ge 93.51(3), C(11)-Ge-H(2) 99.0(1),
P-Ru-Ccentroid 129.7(2).
possibility that this reaction proceeds via concerted addition
of an O-H bond across RudGe, a labeling experiment
utilizing D2O was undertaken. In good agreement with
this mechanism Cp*(iPr2MeP)(H)(D)Ru-GeH(OD)(trip)
(10-d2) formed exclusively as indicated by complete disap-
pearance of the OH resonance of 10 at δ 0.55 and a RuH
signal that integrates as 1H at δ -11.1. No evidence for RuD/
GeH exchange was observed after 6 h in benzene-d6 solution
at ambient temperature.
˚
bond length of 2.2821(6) A (Figure 4). This is especially
notable as 9 represents the first structurally characterized
ruthenium germylene complex, and the ruthenium germa-
˚
nium distance is more than 0.1 A shorter than any previously
reported Ru-Ge bonds.19 Both of the ruthenium- and
germanium-bound hydrogen atoms were located in the
Fourier difference map, and the germanium center is essen-
tially planar (summation of angles at Ge = 359.1°), consis-
tent with a RudGe double bond.
In contrast to silylene complex 3, germylene complex 9 is
thermally stable with no evidence of decomposition indi-
cated after 24 h in toluene-d8 solution at 60 °C (by 1H NMR
spectroscopy). Preliminary experiments indicate that the
related tert-butyl-substituted ruthenium germylene complex
Cp*(iPr2MeP)(H)RudGeH(tBu) is generated in situ by reac-
tion of 2 with tBuGeH3 in benzene-d6.12
Germylene complex 9 is not reactive toward 1 equiv of
common alkenes such as ethylene, 1-hexene, or
tBuCHdCH2 upon heating to reflux for 48 h. However,
treatment of 9 with 1 equiv of oxygen-free H2O in benzene-d6
resulted in quantitative formation of Cp*(iPr2MeP)-
(H)2RudGeH(OH)(trip) (10), as evidenced by 1H NMR
spectroscopy (eq 2). Most diagnostically, two resonances
attributed to the ruthenium hydrides are observed at δ -11.1
and -11.6 and the GeH signal shifts upfield to δ 6.97. The
OH resonance appears at δ 0.55. To lend credence to the
Concluding Remarks. A general route to neutral ruthe-
nium silylene and germylene complexes, including rare hy-
drogen-substituted silylenes and previously unknown
hydrogen-substituted germylene species, has been discov-
ered. The ease of these syntheses should allow a number of
informative spectroscopic and structural comparisons to be
made for this class of complexes. This general synthesis, and
the possibility for inclusion of a range of substituents at the
silicon atom, should also enable a number of reactivity
studies for complexes with Ru-Si and Ru-Ge multiple
bonds.
Experimental Section
General Procedures. All manipulations involving air-sensitive
compounds were conducted using standard Schlenk techniques
under a purified N2 atmosphere or in an MBraun Uni-Lab
drybox. Solvents were distilled under N2 from appropriate
drying agents and stored in PTFE-valved flasks. Deuterated
solvents (Cambridge Isotopes) were dried with appropriate
drying agents and vacuum-transferred prior to use.
(18) See Supporting Information for additional details.
(19) (a) Chan, L. Y. Y.; Graham, W. A. G. Inorg. Chem. 1975, 14,
1778–1781. (b) Ball, R.; Bennett, M. J. Inorg. Chem. 1972, 11, 1806–1811.
(c) Adams, R. D.; Captain, B.; Zhu, L. Inorg. Chem. 2005, 44, 6623–6631.
(d) Adams, R. D.; Captain, B.; Fu, W. Inorg. Chem. 2003, 42, 1328–1333. (e)
Adams, R. D.; Boswell, E. M.; Captain, B.; Patel, M. A. Inorg. Chem. 2007,
47, 533–540. (f) Matsumoto, T.; Nakaya, Y.; Itakura, N.; Tatsumi, K. J. Am.
Chem. Soc. 2008, 130, 2458–2459. (g) Zhang, Y.; Wang, B.; Xu, S.; Zhou, X.
Organometallics 2001, 20, 3829–3832. (h) Adams, R. D.; Captain, B.; Fu,
W. J. Organomet, Chem. 2003, 671, 158–165. (i) Freeman, W. P.; Tilley, T.
D.; Rheingold, A. L.; Ostrander, R. L. Angew. Chem., Int. Ed. 1993, 32,
1744–1745. (j) Howard, J. A. K.; Woodward, P. J. Chem. Soc., Dalton
Silanes and germanes were prepared by LiAlH4 reduction of
the corresponding silyl or germyl chlorides in diethyl ether15 and
were fractionally distilled under N2 or recrystallized from cold
hexanes. Compounds [Cp*RuCl]4,20 iPr2MeP,21 and Mg-
22
(CH2Ph)2(THF)2 were prepared as previously reported. All
(20) Fagan, P. J.; Ward, M. D.; Calabrese, J. C. J. Am. Chem. Soc.
1989, 111, 1698–1719.
Trans. 1978, 412–416. (k) Marciniec, B.; Lawicka, H.; Majchrzak, M.;
Kubicki, M.; Kownacki, I. Chem.;Eur. J. 2006, 12, 244–250.
(21) Betley, T. A.; Peters, J. C. Inorg. Chem. 2003, 42, 5074–5084.
(22) Schrock, R. R. J. Organomet. Chem. 1976, 122, 209–225.
e

Article
Organometallics, Vol. 28, No. 17, 2009 5087
other materials were purchased from Gelest Co. or Aldrich
Chemicals and purified according to standard procedures.
NMR spectra (1H (500.1 MHz), 13C{1H} (124.7 MHz), 31P-
{1H} (202.4 MHz), and 29Si{1H} (99.3 MHz)) were acquired on
a Bruker DRX-500 spectrometer equipped with a 5 mm BBI
probe. Unless otherwise specified, spectra were recorded at
ambient temperature and were referenced to residual proteo
signals in the deuterated solvent for 1H, solvent peaks for 13C,
internal SiMe4 for 29Si, and external 85% H3PO4 for 31P.
Infrared spectra (Nujol mulls, KBr plates) were recorded using
a Mattson FTIR spectrometer at a resolution of 2 cm-1. X-ray
diffraction data were collected on a Bruker Platform goniometer
with a charged coupled device (CCD) detector (Smart Apex).
Structures were solved using the SHELXTL (version 5.1) pro-
gram library. All software and sources of scattering factors are
contained in the SHELXTL (version 5.1) program library.23
Elemental analyses were performed by the University of Cali-
fornia, Berkeley College of Chemistry Microanalytical Facility.
Synthesis of Cp*(iPr2MeP)RuCl (1). Complex 1 was prepared
by modification of a literature preparation.24 A 5 mL CH2Cl2
solution of iPr2MeP (0.42 g, 3.2 mmol) was added dropwise to a
rapidly stirring 4 mL CH2Cl2 suspension of [Cp*RuCl]4 (0.87 g,
0.80 mmol). The reaction mixture immediately became dark
blue-purple, although trace orange color, attributed to local
concentrations of Cp*(iPr2MeP)2RuCl, was observed during the
first 30 s of mixing. The reaction mixture was stirred for an
additional 15 min, at which point the solvent was removed under
reduced pressure to give a dark blue powder, which was
recrystallized from hexanes (3 mL) at -35 °C. Yield: 1.10 g,
0.27 mmol, 85%. 1H NMR (benzene-d6): δ 1.73 (sp, 2H,
CHMe2, JHH = 7.2 Hz), 1.43 (s, 15H, C5Me5), 1.24 (d, 3H,
concentrated to ca. 1 mL and then cooled to -35 °C. Large
orange crystals of 3 were isolated after 2 days. Yield: 0.038 g,
0.063 mmol, 43%. 1H NMR (benzene-d6): δ 9.41 (br s, 1H, SiH),
7.16, (s, 2H, m-C6H2), 4.30-3.52 (br, 2H, o-CHMe2), 2.88 (sp,
1H, p-CHMe2, JHH = 6.8 Hz), 1.88 (br, 2H, PCHMe2), 1.85 (s,
15H, C5Me5), 1.60-1.32 (br ov m, 12H, o-CHMe2), 1.29 (d, 6H,
p-CHMe2, JHH = 6.8 Hz), 1.27 (d, 3H, PMe, 2JHP = 9.1 Hz),
1.13 (dd, 6H, PCHMe2, JHH = 6.8 Hz, 3JHP = 15.1 Hz), 0.97 (br
m, 6H, PCHMe2), -13.5 (br, 1H, RuH). 13C{1H} NMR
(benzene-d6): δ 149.9, 128.3, 119.9 (aromatic C), 92.5 (C5Me5,
2JC-P = 1.7 Hz), 34.9 (o-CHMe2), 34.1 (p-CHMe2), 24.7 (d,
PMe 1JC-P = 14 Hz), 24.4 (p-CHMe2), 18.9, 18.8, 18.4, 18.2 (br,
PCHMe2), 12.3 (C5Me5), 11.2 (br, PMe) (o-CHMe2, PCHMe2
resonances not observed). 31P{1H} NMR (benzene-d6): δ 55.5.
Anal. Calcd for C32H57PRuSi: C, 63.85; H, 9.54. Found: C,
64.12; H, 9.89. Repeated attempts to obtain the 29Si NMR signal
for complex 3, using direct detection and 2-D (HMBC) experi-
ments (ambient and variable temperature), were unsuccessful.
Synthesis of Cp*(iPr2MeP)(H)RudSiH(dmp) (4). A 4 mL
toluene solution of Cp*(iPr2MeP)RuCl (1) (0.10 g, 0.24 mmol)
was added dropwise to solid Mg(CH2Ph)2(THF)2 (0.043 g,
0.12 mmol). The reaction mixture was stirred for 5 min and
then added dropwise to solid dmpSiH3 (0.085 g, 0.25 mmol). The
reaction mixture was stirred for 15 min, during which time the
solution gradually became deep red in color. The solvent was
removed under vacuum to afford an oily red solid. The residue
was extracted with pentane (3 ꢀ 5 mL), the resultant solution
was filtered, and the solvent was removed in vacuo to give 0.139 g
(0.19 mmol, 79%) of a fine orange powder. 1H NMR (benzene-
d6): δ 8.00 (d, 1H, SiH, 3JHP = 11.9 Hz, 1JHSi = 151 Hz), 7.35 (t,
1H, p-C6H3, JHH = 6.0 Hz), 7.00, (d, 2H, m-C6H3, JHH
=
2
PMe, JHP = 6.9), 1.04 (ov m, 12H, CHMe2, JHH = 7.2). All
6.0 Hz), 6.87 (s, 4H, C6H2), 2.45-2.14 (br ov m, 12H,
o-C6H2Me3), 2.21 (s, 6H, p-C6H2Me3), 1.79 (ov s, 15H,
C5Me5), 1.75 (ov sp, 1H, CHMe2, JHH = 6.8 Hz), 1.66 (sp,
1H, CHMe2, JHH = 6.8 Hz), 1.12 (d, 3H, PMe, 2JHP = 6.5 Hz),
0.88-0.68 (ov m, 12H, CHMe2, JHH = 8.0, 6.8 Hz), -14.4 (d,
remaining spectral data matched literature values.24
Synthesis of Cp*(iPr2MeP)Ru(η3-CH2Ph) (2). A 10 mL RB
flask was charged with Cp*(iPr2MeP)RuCl (0.074 g, 0.18 mmol)
and toluene (4 mL). The resultant purple solution was cannula
transferred into a separate 10 mL RB flask containing Mg-
(CH2Ph)2(THF)2 (0.032 g, 0.091 mmol). Within 1 min of rapid
stirring the solution changed color to orange-red. The reaction
mixture was stirred for an additional 10 min, at which point the
solvent was removed in vacuo to afford an oily red solid. The
residue was triturated with pentane (3 ꢀ 5 mL), and the resulting
solution was filtered and concentrated to approximately 2 mL.
Upon cooling to -35 °C for 6 weeks, large red crystals of 2 were
obtained. Yield: 0.061 g, 0.13 mmol, 73%. 1H NMR (benzene-
d6): δ 6.89 (ov m, 3H, Ph), 5.19 (br, 2H, Ph), 1.98 (sp, 2H,
CHMe2, JHH = 7.0 Hz), 1.68 (d, 2H, RuCH2, 3JHP = 8.5 Hz),
2
2
1H, RuH, JHP = 27 Hz, JHSi = 8.6 Hz). 13C{1H} NMR
(benzene-d6): δ 148.0, 145.1, 139.7, 136.5 (aromatic C), 128.5 (m-
C6H2), 128.4 (aromatic C), 128.1 (m-C6H3), 127.7 (p-C6H3), 90.2
1
(C5Me5), 29.2 (d, CHMe2, JCP = 24.5 Hz), 28.3 (d, CHMe2,
1JCP = 25.2 Hz), 21.7 (o-C6H2Me3), 21.1 ( p-C6H2Me3), 19.0
2
2
(d, CHMe2 JCP = 4.9 Hz), 18.5 (d, CHMe2 JCP = 3.8 Hz), 17.7,
17.3 (CHMe2), 12.7 (C5Me5), 10.0 (d, PMe 2JCP = 18.1 Hz). 29Si
NMR (benzene-d6): δ 204. 31P{1H} NMR (benzene-d6): δ 48.5. IR
(Nujol, cm-1): 2051 w (νSiH). Anal. Calcd for C41H59PRuSi: C,
69.16; H, 8.35. Found: C, 68.77; H, 7.98. Mp: 205-208 °C.
Synthesis of Cp*(iPr2MeP)(H)RudSiH(MesF) (5). A 3 mL
benzene solution of Cp*(iPr2MeP)RuCl (1) (0.050 g, 0.12 mmol)
was added dropwise to solid Mg(CH2Ph)2(THF)2 (0.022 g,
0.0062 mmol). The reaction mixture immediately changed color
from purple to orange-red, after which it was stirred for an
additional 10 min and then added dropwise to neat H3SiMesF
(0.035 g, 0.12 mmol). After an additional 10 min the solvent was
removed in vacuo to afford a waxy orange solid. The residue was
extracted with hexanes (3 ꢀ 2 mL) and the solution was filtered
to give a deep red solution. The solvent was then removed to
yield 66 mg (0.097 mmol, 81%) of 5 as an analytically pure ruby
red powder. 1H NMR (benzene-d6): δ 7.83 (s, 2H, m-C6H2), 1.81
(sp, 2H, CHMe2, JHH = 7.2 Hz), 1.68 (s, 15H, C5Me5), 1.13 (dd,
6H, CHMe2, JHH = 7.2 Hz, 3JHP = 6.8 Hz), 1.08 (d, 3H, PMe,
1.41 (s, 15H, C5Me5), 1.24 (dd, 6H, CHMe2, 3JHP = 14.5, JHH
=
7.0), 1.04 (dd, 6H, CHMe2, 3JHP = 10.5, JHH = 7.0), 0.25 (d, 3H,
3
PMe, JHP = 5.0). 13C{1H} NMR (benzene-d6): δ 146.2,
131.8, 118.9, 92.7 (aromatic C), 84.2 (C5Me5), 29.0 (d, CHMe2,
1JCP = 18.8 Hz), 27.9 (RuCH2), 20.6, 18.5 (CHMe2), 10.2
(C5Me5), 3.9 (PMe). 31P{1H} NMR (benzene-d6): δ 47.4. Anal.
Calcd for C24H39PRu: C, 62.72; H, 8.55. Found: C, 62.46; H,
8.75.
Synthesis of Cp*(iPr2MeP)(H)RudSiH(trip) (3). A 3 mL
benzene solution of Cp*(iPr2MeP)RuCl (1) (0.060 g, 0.15 mmol)
was added dropwise to solid Mg(CH2Ph)2(THF)2 (0.026 g,
0.074 mmol). The reaction mixture immediately changed color
from purple to orange-red, after which it was stirred for an
additional 10 min and finally added dropwise to neat tripSiH3
(0.035 g, 0.15 mmol). The reaction mixture was stirred for
20 min, during which time the solution gradually became deep
red in color. The solvent was removed under vacuum to afford a
thick red oil. The residue was extracted with pentane (3 ꢀ 2 mL)
and the resultant solution was filtered. The solution was
2JHP = 6.9 Hz) 0.92 (dd, 6H, CHMe2, JHH = 7.2 Hz, 3JHP
=
6.8 Hz), -13.4 (br, 1H, RuH) (SiH not observed). 19F{1H}
NMR (benzene-d6): δ -56.7 (br s, 6F, o-CF3), -62.0 (s, 3F, p-
CF3). 31P{1H} NMR (benzene-d6): δ 53.6. Anal. Calcd for
C26H34F9PRuSi: C, 46.08; H, 5.06. Found: C, 45.73; H, 5.41.
Repeated attempts to obtain the 29Si NMR signal for complex 5,
using direct detection and 2-D (HMBC) experiments (ambient
and variable temperature), were unsuccessful. This is likely due
to significant broadening of the signal caused by coupling to
nine 19F nuclei in the aryl substituent.16
(23) Sheldrick, G. M. Acta Crystallogr. 2008, A64, 112–122.
(24) Tenorio, M. J.; Puerta, M. C.; Valerga, P. J. Organomet. Chem.
2000, 609, 161–168.

5088 Organometallics, Vol. 28, No. 17, 2009
Table 1. Crystal Data and Structure Refinement Parameters for Complexes 2, 3, 5, and 9
Hayes et al.
2
3
5
9
empirical formula
fw
cryst color, habit
cryst size/mm
cryst syst
C
24H39PRu
C32H57PRuSi
601.91
orange block
0.15 ꢀ 0.10 ꢀ 0.08
monoclinic
P21/c
C26H36F9PRuSi
679.68
orange block
0.11 ꢀ 0.10 ꢀ 0.08
monoclinic
C2/c
C32H57GePRu
646.41
orange block
0.16 ꢀ 0.14 ꢀ 0.11
monoclinic
P21/c
459.59
red block
0.20 ꢀ 0.19 ꢀ 0.17
monoclinic
P21
space group
T/K
152(2)
168(2)
152(2)
145(2)
˚
a/A
8.929(1)
12.617(2)
10.890(1)
90
112.285(2)
90
1135.3(2)
2
0.766
1.344
484
18.746(5)
9.242(2)
19.371(5)
90
98.959(2)
90
3313.1(15)
4
0.575
1.206
1288
19.556(2)
8.7330(7)
34.735(3)
90
100.308(2)
90
5836.3(8)
8
0.705
1.547
2768
18.806(3)
9.128(2)
19.516(3)
90
98.258(2)
90
˚
b/A
˚
c/A
R/deg
β/deg
γ/deg
3
˚
unit cell vol/A
Z
3315.5(9)
4
μ/mm-1
Dcalc (mg/mm3)
F000
1.295
1360
θ range/deg
N
Nind
2.02-26.37
6603
4210
3.06-24.80
14 704
5651
1.19-26.38
16 592
5951
3.16-24.73
14 541
5635
Tmin; Tmax
params
data; param
GoF on R1
R1a (I > 2σ(I))
wR2b (I > 2σ(I))
0.8618; 0.8808
235
17.91
0.9555; 0.9187
324
17.44
0.890
0.0409
0.0851
0.502, -0.595
0.9265; 0.9457
351
16.95
1.033
0.0406
0.1011
0.646, -0.658
0.8038; 0.8588
324
17.39
0.801
0.0325
0.0601
0.527, -0.507
0.996
0.0246
0.0593
0.500, -0.278
P
3
˚
ΔFmax and ΔFmin/e A
P
P
P
a R1 =
Fo| - |Fc
/
|Fo|. b wR2 = { [w(Fo2 - Fc2)2]/ [w(F2o)2]1/2
.
Synthesis of Cp*(iPr2MeP)(H)RudSiPh(trip) (6). A 25 mL
flask equipped with a magnetic stir bar was charged with Cp*-
(iPr2MeP)RuCl (1) (0.050 g, 0.12 mmol) and benzene (5 mL).
The resultant solution was cannula transferred onto solid Mg-
(CH2Ph)2(THF)2 (0.022 g, 0.063 mmol). The reaction mixture
was stirred for an additional 10 min and then added dropwise to
neat Ph(trip)SiH2 (0.039 g, 0.13 mmol). The red solution was
stirred for 5 min and the solvent was removed under reduced
pressure. The residue was extracted with pentane (2 ꢀ 3 mL),
and the resultant solution was filtered. Removal of the solvent
in vacuo afforded 6 as a pale red-pink solid. Yield: 0.044 g,
0.065 mmol, 54%. 1H NMR (benzene-d6): δ 7.85 (br, 2H, Ph),
7.28 (s, 1H, m-C6H2), 7.15 (br, 1H, Ph), 7.07 (s, 2H, Ph), 7.00 (s,
1H, m-C6H2), 4.79 (sp, 1H, CHMe2, JHH = 7.0 Hz), 2.94 (sp,
The resultant solid was extracted with hexanes (4 ꢀ 2 mL) and
the solution was filtered. The solution was then concentrated to
ca. 1 mL and cooled to -35 °C for 24 h. Complex 7 was isolated
as a microcrystalline red-pink solid in 62% yield (0.095 g,
0.15 mmol). H NMR (benzene-d6): δ 7.11, (s, 1H, m-C6H2),
7.05 (s, 1H, m-C6H2), 4.55 (sp, 1H, o-CHMe2, JHH = 6.8 Hz),
3.65 (br m, 1H, o-CHMe2), 2.80 (sp, 1H, p-CHMe2, JHH =
6.8 Hz), 1.91 (ov m, 1H, PCHMe2), 1.87 (s, 15H, C5Me5), 1.84
(ov m, 1H, PCHMe2), 1.52 (d, 3H, o-CHMe2, JHH = 6.8 Hz),
1.46 (d, 3H, o-CHMe2, JHH = 6.8 Hz), 1.44 (d, 3H, o-CHMe2,
1
J
6H, p-CHMe2, JHH = 6.8 Hz), 1.15 (dd, 3H, PCHMe2, JHH
HH = 6.8 Hz), 1.42 (d, 3H, o-CHMe2, JHH = 6.8 Hz), 1.23 (d,
=
6.8 Hz, 3JHP = 2.8 Hz), 1.08 (d, 3H, PMe, 2JHP = 7.3 Hz), 1.04
(ov m, 3H, PCHMe2), 1.02 (dd, 3H, PCHMe2, JHH = 6.8 Hz,
1H, CHMe2, JHH = 7.0 Hz), 2.83 (sp, 1H, CHMe2, JHH
7.0 Hz), 1.91 (s, 15H, C5Me5), 1.62 (d, 3H, o-CHMe2, JHH
=
=
3JHP = 2.8 Hz), 0.89, (dd, 3H, PCHMe2, JHH = 6.8 Hz, 3JHP
=
2
2.8 Hz), -12.68 (d, 1H, RuH, JHP = 30 Hz). 13C{1H} NMR
(benzene-d6): δ 151.0, 150.6, 150.4, 120.7 (aromatic C), 93.8
(C5Me5), 35.4 (o-CHMe2), 34.8 (p-CHMe2), 34.3 (o-CHMe2),
7.0 Hz), 1.61 (m, 1H, PCHMe2), 1.52 (m, 1H, PCHMe2), 1.49 (d,
3H, o-CHMe2, JHH = 7.0 Hz), 1.38 (d, 3H, o-CHMe2, JHH
=
1
7.0 Hz), 1.26 (ov d, 6H, p-CHMe2, JHH = 7.0 Hz), 1.08-1.00 (ov
m, 9H, PCHMe2, PMe), 0.84-0.80 (ov m, 6H, PCHMe2), 0.50
28.6 (ov d, PCHMe2, JC-P = 29 Hz), 26.7, 26.6 (o-CHMe2),
24.2 (p-CHMe2), 23.5, 23.2 (o-CHMe2), 19.1 (PCHMe2), 18.2
(br, PCHMe2), 17.8, 17.0 (PCHMe2), 12.2 (C5Me5), 9.9 (d, PMe
1JC-P = 22 Hz). 29Si NMR (benzene-d6): δ 221.7. 31P{1H}
NMR (benzene-d6): δ 56.9. IR (Nujol, cm-1): 1920 s (νRuH).
Anal. Calcd for C32H56ClPRuSi: C, 60.40; H, 8.87. Found: C,
60.63; H, 9.04. Mp: 124-126 °C.
(d, 3H, o-CHMe2, JHH = 7.0 Hz), -12.5 (d, 1H, RuH, 2JHP
=
30 Hz). 13C{1H} NMR (benzene-d6): δ 154.1, 151.2, 150.1,
134.6, 129.2, 128.7, 127.3, 127.1, 121.2, 121.1 (aromatic C),
93.5 (C5Me5), 35.8 (CHMe2), 34.8 (CHMe2), 33.6 (CHMe2),
29.9 (PCHMe2), 29.6 (PCHMe2), 26.7 (CHMe2), 24.8 (CHMe2),
24.6 (CHMe2), 24.5 (CHMe2), 24.3 (CHMe2), 24.2 (CHMe2),
18.8 (PCHMe2), 18.3 (PCHMe2), 16.6 (PCHMe2), 13.7
(PCHMe2), 12.7 (C5Me5), 11.6 (PMe). 29Si NMR (benzene-
d6): δ 229. 31P{1H} NMR (benzene-d6): δ 55.7 (br) IR (Nujol,
cm-1): 2018 s (νRuH). Anal. Calcd for C38H61PRuSi: C, 67.32; H,
9.07. Found: C, 67.32; H, 8.80. Mp: 129-133 °C.
Synthesis of Cp*(iPr2MeP)(H)RudSiCl(dmp) (8). To a 1 mL
benzene solution of Mg(CH2Ph)2(THF)2 (0.043 g, 0.12 mmol)
was added dropwise a 4 mL benzene solution of Cp*-
(iPr2MeP)RuCl (1) (0.10 g, 0.24 mmol). After stirring for
10 min the reaction mixture was added to solid dmpSiH2Cl
(0.094 g, 0.25 mmol). The reaction mixture was stirred for an
additional 18 h, whereupon the solvent was removed under
reduced pressure to afford a red-brown foam, which was
recrystallized from hexanes (1 mL) at -35 °C. Yield: 0.108 g,
0.063 mmol, 59%. 1H NMR (benzene-d6): δ 7.11 (t, 1H, p-C6H3,
Synthesis of Cp*(iPr2MeP)(H)RudSiCl(trip) (7). To a 5 mL
benzene solution of Mg(CH2Ph)2(THF)2 (0.043 g, 0.12 mmol)
was added dropwise a 4 mL benzene solution of Cp*-
(iPr2MeP)RuCl (1) (0.10 g, 0.24 mmol). After stirring for
10 min the reaction mixture was added to solid tripSiH2Cl
(0.077 g, 0.29 mmol), resulting in a rapid color change from
orange to red-pink. The reaction mixture was stirred for 5 min,
whereupon the solvent was removed under reduced pressure.
J
HH = 7.8 Hz), 6.84 (s, 4H, C6H2), 6.80, (d, 2H, m-C6H3, JHH =
7.8 Hz), 2.50 (s, 6H, p-C6H2Me3), 2.22 (ov m, 14H, PCHMe2,
o-C6H2Me3), 1.75 (ov sp, 2H, CHMe2, JHH = 6.8 Hz), 1.72 (ov
s, 15H, C5Me5), 0.93-0.85 (ov m, 15H, PMe, PCHMe2),

Article
Organometallics, Vol. 28, No. 17, 2009 5089
-13.0 (d, 1H, RuH, 2JHP = 28 Hz). 13C{1H} NMR (benzene-
d6): δ 152.2, 139.8, 137.8, 136.7 (aromatic C), 129.9 (p-C6H3),
129.0 (m-C6H3), 128.6 (m-C6H2), 128.3, (aromatic C), 94.1
0.55 (s, 1H, OH), -11.1 (d, 1H, RuH, 2JHP = 28 Hz), -11.6 (d,
1H, RuH, 2JHP = 28 Hz). 31P{1H} NMR (benzene-d6): δ 63.9.
In Situ Generation of Cp*(iPr2MeP)(H)(D)Ru-GeH(OD)-
(trip) (10-d2). A 10 μL syringe was utilized to add thoroughly
deoxygenated D2O (0.43 μL, 0.024 mmol) dropwise to a 0.5 mL
benzene-d6 solution of Cp*(iPr2MeP)(H)RudGeH(trip) (9)
(0.010 g, 0.024 mmol). The reaction mixture immediately chan-
ged from orange-red to colorless. 1H NMR (benzene-d6): δ 7.14
(s, 2H, m-C6H2), 6.97 (s, 1H, GeH), 3.98 (sp, 2H, o-CHMe2,
2
(C5Me5, JCP = 1.7 Hz), 23.0 (p-C6H2Me3), 22.5, 21.8 (br,
CHMe2), 21.1 (o-C6H2Me3), 20.2, 18.9, 18.3, 18.2 (CHMe2),
11.8 (C5Me5), 11.2 (br, PMe). 29Si NMR (benzene-d6): δ 205.
31P{1H} NMR (benzene-d6):
δ 57.9. Anal. Calcd for
C41H58ClPRuSi: C, 65.97; H, 7.83. Found: C, 65.32; H, 7.56.
Synthesis of Cp*(iPr2MeP)(H)RudGeH(trip) (9). A 4 mL
benzene solution of Cp*(iPr2MeP)RuCl (1) (0.10 g, 0.24 mmol)
was added dropwise to solid Mg(CH2Ph)2(THF)2 (0.043 g, 0.12
mmol). The reaction mixture immediately changed in color from
purple to orange-red, after which it was stirred for an additional
10 min and then added dropwise to neat tripGeH3 (0.14 g,
0.36 mmol). The reaction mixture was stirred for 10 min, during
which time the solution gradually became deep orange in color.
The solvent was removed under vacuum to afford an orange
solid, which was extracted with hexanes (5 ꢀ 2 mL) and filtered.
The resultant solution was reduced to 1 mL and cooled to
-35 °C for 24 h. Yield: 0.10 g, 0.16 mmol, 67%. 1H NMR
(benzene-d6): δ 12.39 (s, 1H, GeH), 7.14 (s, 2H, m-C6H2), 3.56
(br m, 2H, o-CHMe2), 2.87 (sp, 1H, p-CHMe2, JHH = 6.9 Hz),
1.85, 1.83 (ov m, 2H, PCHMe2, JHH = 6.9 Hz), 1.84 (s, 15H,
C5Me5), 1.40, 1.34 (br ov m, 12H, o-CHMe2), 1.29 (d, 6H, p-
CHMe2, JHH = 6.9 Hz), 1.23 (d, 3H, PMe, 2JHP = 7.3 Hz), 1.09
(dd, 6H, PCHMe2, JHH = 6.9 Hz, 3JHP = 2.8 Hz), 1.09 (ov m,
6H, PCHMe2, JHH = 6.9 Hz), -12.81 (d, 1H, RuH, 2JHP = 31
Hz). 13C{1H} NMR (benzene-d6): δ 151.6, 150.7, 149.3, 120.3
(aromatic C), 92.6 (d, C5Me5, 2JHP = 1.9 Hz), 34.9 (p-CHMe2),
33.9 (o-CHMe2), 32.1 (br, o-CHMe2), 29.6 (d, PCHMe2,
J
HH = 6.8 Hz), 2.85 (sp, 1H, p-CHMe2, JHH = 6.8 Hz), 1.82-
1.72 (ov m, 17H, PCHMe2, C5Me5), 1.52 (d, 12H, o-CHMe2,
HH = 6.8 Hz), 1.30 (d, 6H, p-CHMe2, JHH = 6.8 Hz), 1.20 (d,
J
2
3H, PMe, JHP = 7.3 Hz), 0.99-0.81 (ov m, 12H, PCHMe2),
-11.1 (d, 1H, RuH, 2JHP = 28 Hz). 31P{1H} NMR (benzene-d6):
δ 63.9.
X-ray Structure Determinations. X-ray diffraction data were
collected on a Bruker APEX CCD platform diffractometer
˚
(Mo KR (λ = 0.71073 A)). Suitable crystals of the complexes
were mounted in a nylon loop with Paratone-N cryoprotectant
oil. The structures were solved using a Patterson search for
heavy elements and standard difference map techniques. Re-
finement was done by full-matrix least-squares procedures on F2
with SHELXTL.23 All non-hydrogen atoms were refined aniso-
tropically. Hydrogen atoms on carbon were included in calcu-
lated positions and were refined using a riding model. Hydrogen
atoms on ruthenium (H(1) for 3 and 9) and silicon or germanium
(H(2) for 3, 5, and 9) were located in the Fourier difference map
and freely refined. Crystal data and refinement details are
presented in Table 1. Complexes 3, 5, and 9 displayed minor
disorder of the methyl substituents that had no serious effect on
the solution of the structures. Nonmodeled solutions are pre-
sented for simplicity given limited improvement in quality of
refinement that modeling provided.
1
2JC-P = 23 Hz), 27.4 (d, PCHMe2, JC-P = 27 Hz), 24.5 (ov
m, p-CHMe2, o-CHMe2), 18.7, 17.9, 17.1 (PCHMe2), 12.4
1
(C5Me5), 10.6 (d, PMe JC-P = 22 Hz). 31P{1H} NMR
(benzene-d6): δ 57.6. IR (Nujol, cm-1): 1969 s (νRuH). Anal.
Calcd for C32H57GePRu: C, 59.45; H, 8.89. Found: C, 59.53; H,
8.67. Mp: 135-137 °C.
Acknowledgment. This work was supported by the
U.S. National Science Foundation (No. 0132099). Sup-
port for P.G.H. through an NSERC of Canada Post-
doctoral Fellowship (PDF), and for R.W. by a Miller
Institute for Basic Research in Science Research Fellow-
ship, is gratefully acknowledged. Chris Gribble and Elisa
Calimano are thanked for collecting experimental data.
In Situ Generation of Cp*(iPr2MeP)(H)2Ru-GeH(OH)(trip)
(10). A 10 μL syringe was utilized to add thoroughly deoxyge-
nated water (0.43 μL, 0.024 mmol) dropwise to a 0.5 mL
benzene-d6 solution of Cp*(iPr2MeP)(H)RudGeH(trip) (9)
(0.010 g, 0.024 mmol). The reaction mixture immediately chan-
ged from orange-red to colorless. 1H NMR (benzene-d6): δ 7.14
(s, 2H, m-C6H2), 6.97 (s, 1H, GeH), 3.98 (sp, 2H, o-CHMe2,
Supporting Information Available: Experimental details
and crystallographic data (CIF) for 2, 3, 5, 7, and 9. This
material is available free of charge via the Internet at http://
pubs.acs.org.
J
HH = 6.8 Hz), 2.85 (sp, 1H, p-CHMe2, JHH = 6.8 Hz), 1.82-
1.72 (ov m, 17H, PCHMe2, C5Me5), 1.52 (d, 12H, o-CHMe2,
HH = 6.8 Hz), 1.30 (d, 6H, p-CHMe2, JHH = 6.8 Hz), 1.20 (d,
J
2
3H, PMe, JHP = 7.3 Hz), 0.99-0.81 (ov m, 12H, PCHMe2),