Silylene extrusion from organosilanes via double geminal Si-H bond activation by a Cp*Ru(κ2-P,N)+ complex: Observation of a key stoichiometric step in the Glaser-Tilley alkene hydrosilylation mechanism

Article abstract of DOI:10.1021/ja0768800

Treatment of Cp*RuCl(κ²-P,N-2b) (2b = 2-NMe ₂-3-PⁱPr₂-indene) with TISO₃CF ₃ produced the cyclometalated complex [4]^-SO ₃CF₃^- in 94% isolated yield. Exposure of [4]⁺X^- (X = B(C₆F₅)₄ or SO₃CF₃) to Ph₂SiH₂ (10 equiv) or PhSiH₃ afforded the corresponding [Cp*(μ-P,N-2b)(H) ₂Ru=SiRPh]⁺X^- complexes, [5]⁺X ^- (R = Ph; X = B(C₆F₅)₄, 82%; X = SO₃CF₃, 39%) and [6]⁺X^- (R = H; X = B(C₆F₅)₄, 94%; X = SO₃CF ₃, 95%). Notably, these transformations represent the first documented examples of Ru-mediated silylene extrusion via double geminal Si-H bond activation of an organosilane - a key step in the recently proposed Glaser - Tilley (G-T) alkene hydrosilylation mechanism. Treatment of [5] ⁺B(C₆F₅)₄^- with KN-(SiMe₃)₂ or [6]⁺SO₃CF ₃^- with NaN(SiMe₃)₂ afforded the corresponding zwitterionic Cp*(μ-2-NMe₂-3-P ⁱPr₂-indenide)(H)₂Ru=SiRPh complex in 69% (R = Ph, 7) or 86% (R = H, 8) isolated yield. Both [6]⁺X^- and 8 proved unreactive toward 1 -hexene and styrene and provided negligible catalytic turnover in the attempted metal-mediated hydrosilylation of these substrates with PhSiH₃, thereby providing further empirical evidence for the required intermediacy of base-free Ru=Si species in the G-T mechanism. Isomerization of the P,N-indene ligand backbone in [6]⁺X^_, giving rise to [Cp*(μ-1-PⁱPr₂-2-NMe ₂-indene)(H)₂Ru=SiHPh]⁺X^- ([9] ⁺X^-), was observed. In the case of [9]⁺SO ₃CF₃^-, net intramolecular addition of the Ru=Si-H group across the styrene-like C=C unit within the ligand backbone to give 10 (96% isolated yield) was observed. Crystallographic characterization data are provided for [4]⁺X^-, [5]⁺X ^-, [6]⁺X^-, 8, and 10.

Full text of DOI:10.1021/ja0768800

Published on Web 12/04/2007
Silylene Extrusion from Organosilanes via Double Geminal
Si-H Bond Activation by a Cp*Ru(K2-P,N)+ Complex:
Observation of a Key Stoichiometric Step in the Glaser-Tilley
Alkene Hydrosilylation Mechanism
Matthew A. Rankin,† Darren F. MacLean,† Gabriele Schatte,‡
Robert McDonald,§ and Mark Stradiotto*,†
Department of Chemistry, Dalhousie UniVersity, Halifax, NoVa Scotia, Canada B3H 4J3,
Saskatchewan Structural Sciences Centre, UniVersity of Saskatchewan, Saskatoon, SK Canada
S7N 5C9, X-Ray Crystallography Laboratory, Department of Chemistry, UniVersity of Alberta,
Edmonton, Alberta, Canada T6G 2G2
Received September 11, 2007; E-mail: mark.stradiotto@dal.ca
Abstract: Treatment of Cp*RuCl(κ2-P,N-2b) (2b ) 2-NMe2-3-PiPr2-indene) with TlSO3CF3 produced the
cyclometalated complex [4]+SO3CF3- in 94% isolated yield. Exposure of [4]+X- (X ) B(C6F5)4 or SO3CF3)
to Ph2SiH2 (10 equiv) or PhSiH3 afforded the corresponding [Cp*(µ-P,N-2b)(H)2RudSiRPh]+X- complexes,
[5]+X- (R ) Ph; X ) B(C6F5)4, 82%; X ) SO3CF3, 39%) and [6]+X- (R ) H; X ) B(C6F5)4, 94%; X )
SO3CF3, 95%). Notably, these transformations represent the first documented examples of Ru-mediated
silylene extrusion via double geminal Si-H bond activation of an organosilanesa key step in the recently
proposed Glaser-Tilley (G-T) alkene hydrosilylation mechanism. Treatment of [5]+B(C6F5)4 with KN-
-
(SiMe3)2 or [6]+SO3CF3- with NaN(SiMe3)2 afforded the corresponding zwitterionic Cp*(µ-2-NMe2-3-PiPr2-
indenide)(H)2RudSiRPh complex in 69% (R ) Ph, 7) or 86% (R ) H, 8) isolated yield. Both [6]+X- and 8
proved unreactive toward 1-hexene and styrene and provided negligible catalytic turnover in the attempted
metal-mediated hydrosilylation of these substrates with PhSiH3, thereby providing further empirical evidence
for the required intermediacy of base-free RudSi species in the G-T mechanism. Isomerization of the
P,N-indene ligand backbone in [6]+X-, giving rise to [Cp*(µ-1-PiPr2-2-NMe2-indene)(H)2RudSiHPh]+X-
([9]+X-), was observed. In the case of [9]+SO3CF3-, net intramolecular addition of the RudSi-H group
across the styrene-like CdC unit within the ligand backbone to give 10 (96% isolated yield) was observed.
Crystallographic characterization data are provided for [4]+X-, [5]+X-, [6]+X-, 8, and 10.
Introduction
lation mechanism involving RudSi intermediates was provided.
Key mechanistic steps in the proposed pathway for such
Transition metal silylene complexes featuring a formal
MdSi linkage have been the subject of ongoing scrutiny over
the past two decades, due in part to the key role that such
reactive intermediates are proposed to play in a diversity of
metal-mediated transformations,1 including the direct pro-
cess for the industrial synthesis of chlorosilanes from silicon
and chlorocarbons.2 Interest in such complexes intensified
following a report by Glaser and Tilley in 2003,3 in which
experimental evidence for an unprecedented alkene hydrosily-
hydrosilylations employing the metal silylene precatalyst
[Cp*(iPr3P)(H)2RudSiHPh‚OEt2]+B(C6F5)4 (1; Cp* ) η5-
-
C5Me5) and the generic olefin R′CHdCH2 include (Scheme
1): (i) double geminal Si-H bond activation of RSiH3 by
[Cp*(iPr3P)Ru]+ (1a) to afford [Cp*(iPr3P)(H)2RudSiHR]+
(1b), for which the metallasilicenium ion 1b′ represents an
important resonance contributor; (ii) direct, regioselective ad-
dition of the RudSi-H bond in 1b to the alkene substrate to
give [Cp*(iPr3P)(H)2RudSi(CH2CH2R′)R]+ (1c); (iii) H-migra-
tion from Ru to Si in 1c to give [Cp*(iPr3P)(H)Ru-SiH-
(CH2CH2R′)R]+ (1d); and (iv) Si-H reductive elimination of
RSiH2(CH2CH2R′) with concomitant regeneration of 1a. In stark
contrast to more traditional alkene hydrosilylation processes,4
and in keeping with the proposed mechanism, only primary
silanes were found to be compatible substrates when employing
pre-catalyst 1, whereas even trisubstituted alkenes underwent
hydrosilylation to afford exclusively the corresponding anti-
† Dalhousie University.
‡ University of Saskatchewan.
§ University of Alberta.
(1) For reviews, see: (a) Waterman, R.; Hayes, P. G.; Tilley, T. D. Acc. Chem.
Res. 2007, 40, 712. (b) Okazaki, M.; Tobita, H.; Ogino, H. Dalton Trans.
2003, 493. (c) Ogino, H. Chem. Rec. 2002, 2, 291. (d) Ogino, H.; Tobita,
H. AdV. Organomet. Chem. 1998, 42, 223. (e) Zybill, C.; Handwerker, H.;
Friedrich, H. AdV. Organomet. Chem. 1994, 36, 229. (f) Tilley, T. D. In
Chemistry of Organosilicon Compounds; Patai, S., Rappoport, Z., Eds.;
Wiley: Chichester, U.K., 1989; Chapter 24, p 1415.
(2) (a) Brook, M. A. Silicon in Organic, Organometallic, and Polymer
Chemistry; Wiley: New York, 2000; p 381. (b) Lewis, L. N. In Chemistry
of Organosilicon Compounds; Rappoport, Z., Apeloig, Y., Eds.; Wiley:
Chichester, UK 1998; Pt 2, p 1581.
(3) (a) Glaser, P. B.; Tilley, T. D. J. Am. Chem. Soc. 2003, 125, 13640. (b)
For a discussion of the Glaser-Tilley hydrosilylation mechanism, see:
Brunner, H. Angew. Chem., Int. Ed. 2004, 43, 2749.
(4) For discussions of the Chalk-Harrod and the modified Chalk-Harrod
mechanisms of alkene hydrosilylation, see: Sakaki, S.; Sumimoto, M.;
Fukuhara, M.; Sugimoto, M.; Fujimoto, H.; Matsuzaki, S. Organometallics
2002, 21, 3788.
9
10.1021/ja0768800 CCC: $37.00 © 2007 American Chemical Society
J. AM. CHEM. SOC. 2007, 129, 15855-15864
15855

A R T I C L E S
Rankin et al.
Scheme 1. Simplified View of the Glaser-Tilley Mechanism for
Alkene Hydrosilylation
geminal Si-H bond activation chemistry involving Ph2SiH2 or
PhSiH3 by [Cp*Ru(κ2-P,N)]+X- species to afford crystallo-
graphically characterized products in which the initially κ2-P,N
ligand spans the RudSi fragment. The reactivity properties of
the derived base-stabilized cationic RudSi complexes are also
documented, including the observation of intramolecular alkene
insertion into a RudSi-H fragment, and the formation of the
first formally zwitterionic (neutral) RudSi species.
Results and Discussion
One aspect of our research program focuses on the develop-
ment of new, coordinatively unsaturated metal complexes
derived from 1-PiPr2-2-NMe2-indene (2a), 2-NMe2-3-PiPr2-
indene (2b), 2-NMe2-3-PiPr2-indenide (2c), and related ligands,
for use in mediating substrate E-H bond activation chemistry
(E ) main group element).11 In this context, we have reported
previously on our efforts to prepare [Cp*Ru(κ2-P,N-2b)]+B-
(C6F5)4- ([3]+B(C6F5)4-) via treatment of Cp*RuCl(κ2-P,N-2b)
with Li(Et2O)2.5B(C6F5)4.11e Whereas the cyclometalated species
Markovnikov product in the absence of double-addition (i.e.,
RSiH(CH2CH2R′)2) or vinylsilane byproducts.5
Computational investigations6 and stoichiometric reactivity
studies have figured importantly in validating some of the key
steps of the proposed Glaser-Tilley (G-T) hydrosilylation
mechanism, as well as in providing insight into the role of charge
distribution on the reactivity of the Si-H fragment in intermedi-
ates such as 1b/1b′. The feasibility of the proposed direct
addition of a RudSi-H bond to an olefinic substrate was
demonstrated through the observed reaction of 1 with 1-hex-
ene to afford [Cp*(iPr3P)(H)2RudSi(hexyl)Ph]+B(C6F5)4- (i.e.,
1c where R′ ) C4H9).3 Whereas the related Os complex
-
[4]+B(C6F5)4 was identified as the Ru-containing product
obtained from this reaction on the basis of single-crystal
X-ray diffraction data, variable-temperature NMR data revealed
that the apparent cyclometalation of [3]+B(C6F5)4 to give
-
[4]+B(C6F5)4- is reversible (Scheme 2).11e We have discovered
subsequently that Cp*RuCl(κ2-P,N-2b) also reacts cleanly with
-
TlSO3CF3 to afford [4]+SO3CF3 in 94% isolated yield. An
-
ORTEP12 diagram of [4]+SO3CF3 is provided in Figure 1,
while X-ray experimental data and selected metrical parameters
for each of the crystallographically characterized complexes
reported herein are collected in Tables 1, 2, and 3. The structural
[Cp*(iPr3P)(H)2OsdSiH(trip)]+B(C6F5)4 (trip ) 2,4,6-iPr3-
-
C6H2) reacts rapidly with alkenes in a similar manner,3 the
observation that the neutral silylene complex Cp*(iPr3P)(H)-
OsdSiH(trip) is unreactive under similar conditions underscores
the influence of formal charge on such hydrosilylation processes,
as well as the potential importance of resonance contributors
such as 1b′ in the catalytic hydrosilylation chemistry derived
from 1.7 However, despite the existence of structurally char-
acterized RudSi species8,9 and the demonstrated ability of a
rather small number of mononuclear complexes of groups 6-9
to mediate silylene extrusion from organosilanes via thermally
promoted Si-H oxidative addition/R-H migration pathways,10
the direct formation of RudSi species via double geminal Si-H
bond activation of a silane (as required by the G-T mechanism)
has not been documented previously in the literature. Herein
we report on the observation of such stoichiometric double
features found in [4]+SO3CF3- mirror those of [4]+B(C6F5)4
- 11e
,
as well as some other crystallographically characterized azaru-
thenacyclopropanes.13
Base-Stabilized RudSi Complexes Formed via Double
Si-H Bond Activation. Given the apparent ability of [4]+X-
(X ) B(C6F5)4 or SO3CF3) to reversibly activate C-H bonds
in an intramolecular fashion, we became interested in exploiting
these complexes as masked sources of [3]+X- in the pursuit of
new metal-mediated intermolecular E-H bond activation chem-
-
istry. Treatment of [4]+B(C6F5)4 with Ph2SiH2 (10 equiv)
afforded after 48 h a single phosphorus-containing product
([5]+B(C6F5)4-; Scheme 2), which in turn was obtained in 82%
1
-
isolated yield. Both H and 13C NMR data for [5]+B(C6F5)4
(10) (a) Mork, B. V.; Tilley, T. D.; Schultz, A. J.; Cowan, J. A. J. Am. Chem.
Soc. 2004, 126, 10428. (b) Mork, B. V.; Tilley, T. D. J. Am. Chem. Soc.
2004, 126, 4375. (c) Glaser, P. B.; Tilley, T. D. Organometallics 2004,
23, 5799. (d) Gusev, D. G.; Fontaine, F.-G.; Lough, A. J.; Zargarian, D.
Angew. Chem., Int. Ed. 2003, 42, 216. (e) Mork, B. V.; Tilley, T. D. Angew.
Chem., Int. Ed. 2003, 42, 357. (f) Feldman, J. D.; Peters, J. C.; Tilley, T.
D. Organometallics 2002, 21, 4065. (g) Mork, B. V.; Tilley, T. D. J. Am.
Chem. Soc. 2001, 123, 9702. (h) Sakaba, H.; Tsukamoto, M.; Hirata, T.;
Kabuto, C.; Horino, H. J. Am. Chem. Soc. 2000, 122, 11511. (i) Klei, S.
R.; Tilley, T. D.; Bergman, R. G. J. Am. Chem. Soc. 2000, 122, 1816. (j)
Peters, J. C.; Feldman, J. D.; Tilley, T. D. J. Am. Chem. Soc. 1999, 121,
9871. (k) Reference 7 herein.
(11) For selected examples, see: (a) Lundgren, R. J.; Rankin, M. A.; McDonald,
R.; Schatte, G.; Stradiotto, M. Angew. Chem., Int. Ed. 2007, 46, 4732. (b)
Cipot, J.; McDonald, R.; Ferguson, M. J.; Schatte, G.; Stradiotto, M.
Organometallics 2007, 26, 594. (c) Wile, B. M.; Burford, R. J.; McDonald,
R.; Ferguson, M. J.; Stradiotto, M. Organometallics 2006, 25, 1028. (d)
Wechsler, D.; Myers, A.; McDonald, R.; Ferguson, M. J.; Stradiotto, M.
Inorg. Chem. 2006, 45, 4562. (e) Rankin, M. A.; McDonald, R.; Ferguson,
M. J.; Stradiotto, M. Organometallics 2005, 24, 4981. (f) The ligand 1-Pi-
Pr2-2-NMe2-indene (2b) is commercially available.
(5) Ru-mediated dehydrogenative silylation of alkenes is well-established: Seki,
Y.; Takeshita, K.; Kawamoto, K.; Murai, S.; Sonoda, N. Angew. Chem.,
Int. Ed. Engl. 1980, 19, 928.
(6) (a) Beddie, C.; Hall, M. B. J. Phys. Chem. A 2006, 110, 1416. (b) Bo¨hme,
U. J. Organomet. Chem. 2006, 691, 4400. (c) Beddie, C.; Hall, M. B. J.
Am. Chem. Soc. 2004, 126, 13564.
(7) Hayes, P. G.; Beddie, C.; Hall, M. B.; Waterman, R.; Tilley, T. D. J. Am.
Chem. Soc. 2006, 128, 428.
(8) For crystallographically characterized “base-free” RudSi complexes, see:
(a) Yoo, H.; Carroll, P. J.; Berry, D. H. J. Am. Chem. Soc. 2006, 128,
6038. (b) Amoroso, D.; Haaf, M.; Yap, G. P. A.; West, R.; Fogg, D. E.
Organometallics 2002, 21, 534. (c) Schmedake, T. A.; Haaf, M.; Paradise,
B. J.; Millevolte, A. J.; Powell, D. R.; West, R. J. Organomet. Chem. 2001,
636, 17. (d) Grumbine, S. K.; Mitchell, G. P.; Straus, D. A.; Tilley, T. D.
Organometallics 1998, 17, 5607. (e) Grumbine, S. K.; Tilley, T. D.; Arnold,
F. P.; Rheingold, A. L. J. Am. Chem. Soc. 1994, 116, 5495.
(9) For crystallographically characterized “base-stabilized” RudSi complexes,
see: (a) Choo, T. N.; Kwok, W.-H.; Rickard, C. E. F.; Roper, W. R.;
Wright, L. J. J. Organomet. Chem. 2002, 645, 235. (b) Tobita, H.; Kurita,
H.; Ogino, H. Organometallics 1998, 17, 2850. (c) Mitchell, G. P.; Tilley,
T. D. J. Am. Chem. Soc. 1997, 119, 11236. (d) Straus, D. A.; Zhang, C.;
Quimbita, G. E.; Grumbine, S. D.; Heyn, R. H.; Tilley, T. D.; Rheingold,
A. L.; Geib, S. J. J. Am. Chem. Soc. 1990, 112, 2673. (e) Straus, D. A.;
Tilley, T. D.; Rheingold, A. L.; Geib, S. J. J. Am. Chem. Soc. 1987, 109,
5872. (f) Reference 8d herein.
(12) Farrugia, L. J. ORTEP-3 for Windows, version 1.074. J. Appl. Crystallogr.
1997, 30, 565.
(13) (a) Liptau, P.; Carmona, D.; Oro, L. A.; Lahoz, F. J.; Kehr, G.; Erker, G.
Eur. J. Inorg. Chem. 2004, 4586. (b) Mauthner, K.; Slugovc, C.; Mereiter,
K.; Schmid, R.; Kirchner, K. Organometallics 1997, 16, 1956.
9
15856 J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007

RudSi Complexes
A R T I C L E S
Scheme 2. Silylene Extrusion from Ph2SiH2 or PhSiH3 to Afford
the Base-Stabilized RudSi Species [5]+X- and [6]+X-
Chart 1. Three Simplified Representations of the Bonding within
the Ru-Si-N Fragments of [5]+X- (R ) Ph) and [6]+X- (R ) H).
N (Chart 1). Notably, the crystallographically determined Ru-H
positions in [5]+SO3CF3-, when considered along with the very
2
-
small JSiH values measured for [5]+B(C6F5)4 (<10 Hz),
suggest that any interaction between the Ru(H)2 ligands and Si
in [5]+X- takes the form of a highly unsymmetrical Ru-H‚‚‚
Si bridging motif.18
Having documented the first Ru-mediated silylene extrusion
process in the apparent reaction of [3]+X- with Ph2SiH2 leading
to [5]+X-, we turned our attention to reactions employing
PhSiH3 in an effort to observe double geminal Si-H activation
chemistry that is of direct relevance to the proposed G-T hydro-
silylation mechanism. Gratifyingly, upon exposure to one equiv-
alent of PhSiH3, each of [4]+X- were transformed cleanly over
the course of 30 min into the corresponding [Cp*(µ-P,N-2b)-
(H)2RudSiHPh]+X- complex ([6]+X-) in 94% (X ) B(C6F5)4)
1
or 95% (X ) SO3CF3) isolated yield (Scheme 2). The H and
13C NMR spectra of [6]+X- are entirely consistent with the
C1-symmetric nature of these complexes, including the observa-
tion of diagnostic resonances for the magnetically nonequivalent
Ru-H ligands and the Si-H group. An ORTEP12 diagram of
supported a preliminary assessment of this complex as contain-
ing a Cs-symmetric Cp*(PR3)Ru(H)2 moiety. While a more
complex mixture of products was generated when employing
[4]+SO3CF3- under similar conditions (31P NMR), the analogous
salt [5]+SO3CF3- was isolated from the reaction mixture in 39%
isolated yield. The assignment of [5]+X- as base-stabilized
[Cp*(µ-P,N-2b)(H)2RudSiPh2]+X- complexes, presumably aris-
ing from initial Si-H oxidative addition to [3]+X- followed
by some combination of R-H transfer from Si to Ru and
migration of the N-donor fragment from Ru to Si,14 was
achieved through the crystallographic characterization of
[6]+SO3CF3 is provided in Figure 1 and represents the first
-
crystallographically characterized RudSiHR complex.19 The
overall structural features found in [6]+SO3CF3 mirror those
-
observed in [5]+SO3CF3-, with the exception of a slight contrac-
tion of the RudSi (2.262(2) Å) and Si-N (1.955(4) Å) linkages
in the former relative to the latter. Interestingly, despite the base-
stabilized nature of the silylene fragment in [6]+SO3CF3-, the
observed RudSi distance is only marginally longer than that
of the base-free silylene complex [Cp*(Me3P)2RudSiMe2]+B-
(C6F5)4 .
- 17 In keeping with [5]+X-, the lack of discernible 2JSiH
-
[5]+SO3CF3-. An ORTEP12 diagram of [5]+SO3CF3 is pro-
coupling for [6]+X- suggests little or no interaction between
the Ru(H)2 ligands and Si in [6]+X-.18 The migration of an
ancillary ligand P-donor fragment from M to Si in the formation
of base-stabilized MdSiH(X) species from excess PhSiH3 has
been reported (M ) Os, X ) H;10d M ) Co, X ) NR219a).
However, while each of these transformations resulted in the
degradation of the initially coordinated ancillary ligand, the
structural integrity of ligand 2b was retained upon formation
of [6]+X-. Although indirect evidence for reversible R-H migra-
tion leading to the formation of MdSi species has been pub-
lished,1a the absence of observable chemical exchange (1H
EXSY) involving the Ru-H and Si-H groups within [6]+X-
or 8 (vide infra) suggests that R-H migration from Si to Ru in
these complexes, if reversible, must occur with associated rates
that are slow relative to the dynamic exchange NMR time
scale.20
vided in Figure 1. The relatively short RudSi (2.2811(9) Å)
and long Si-N (1.988(3) Å) linkages in [5]+SO3CF3- 15,16 when
,
compared to related distances found in [Cp*(Me3P)2Rud
SiPh2‚NCMe]+BPh4 (2.328(2) Å and 1.932(8) Å, respec-
-
tively),9d,e may point to heightened silylene character in
[5]+SO3CF3 relative to this acetonitrile adduct. Nonetheless,
-
-
the significant pyramidalization at Si (342.7° in [5]+SO3CF3
)
and the relatively low-frequency 29Si NMR chemical shift
associated with [5]+B(C6F5)4 (δ 29Si ) 107 ppm) clearly
-
distinguish such salts from related base-free silylene complexes
including [Cp*(iPr3P)(H)2RudSi(hexyl)Ph]+B(C6F5)4 (δ 29Si
-
) 252)3a and [Cp*(Me3P)2RudSiR2]+B(C6F5)4- (δ 29Si ) 311,
R ) Me; δ 29Si ) 299, R ) Ph).8d,e,17 In this regard, the bonding
in [5]+X- is perhaps best represented by a hybrid of resonance
contributors that feature formal positive charges on Ru, Si, or
(14) Alternative reaction pathways leading to [5]+X- involving initial Si-H
oxidative addition to [4]+X-, and/or featuring σ-bond metathesis steps, can
also be envisioned.
Zwitterionic, Base-Stabilized RudSi Complexes. We have
demonstrated previously for some [(κ2-P,N-2b)MLn]+X- com-
(15) Crystallographically characterized (CO)5CrdSi(Ph)n(o-C6H4CH2NMe2)2-n
(n ) 0 or 1) complexes in which a pendant NMe2 group is coordinated to
Si (n ) 0, Si-N 2.046(2) Å; n ) 1, Si-N 1.991(2) Å) have been
reported: Handwerker, H.; Leis, C.; Probst, R.; Bissinger, P.; Grohmann,
A.; Kiprof, P.; Herdtweck, E.; Blu¨mel, J.; Auner, N.; Zybill, C. Organo-
metallics 1993, 12, 2162.
(16) By comparison, the Ru-Si and Si-N distances observed in two related
complexes featuring a Cp*Ru-SiR2-NR′2 framework fall within the range
of 2.4-2.5 Å and 1.7-1.8 Å, respectively: (a) Iwata, M.; Okazaki, M.;
Tobita, H. Organometallics 2006, 25, 6115. (b) Reference 9c herein.
(17) Crystallographic data for [Cp*(Me3P)2RudSiMe2]+B(C6F5)4- (from refer-
ences 8d,e herein): RudSi 2.238(3) Å; ∑angles
) 358.7°.
at Si
(18) (a) Lachaize, S.; Sabo-Etienne, S. Eur. J. Inorg. Chem. 2006, 2115. (b)
Corey, J. Y.; Braddock-Wilking, J. Chem. ReV. 1999, 99, 175.
(19) Crystallographically characterized MdSiHR species are rare: (a) Ingleson,
M.; Fan, H.; Pink, M.; Tomaszewski, J.; Caulton, K. G. J. Am. Chem. Soc.
2006, 128, 1804. (b) Watanabe, T.; Hashimoto, H.; Tobita, H. J. Am. Chem.
Soc. 2006, 128, 2176. (c) Watanabe, T.; Hashimoto, H.; Tobita, H. Angew.
Chem., Int. Ed. 2004, 43, 218. (d) References 7 and 10a,d cited herein.
9
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A R T I C L E S
Rankin et al.
Figure 1. The crystallographically determined structures of [4]+X-, [5]+X-, [6]+X-, 8, and 10 shown with 50% displacement ellipsoids (X ) SO3CF3).
The triflate counterions and selected H-atoms have been omitted for clarity.
Table 1. Crystallographic Data for [4]+X-, [5]+X-, and [6]+X-
-
-
-
[4]+SO3CF3
[5]+SO3CF3
[6]+SO3CF3
empirical formula
formula weight
crystal dimensions (mm3)
crystal system
space group
a (Å)
C28H41F3N1O3P2Ru1S1
660.72
0.20 × 0.20 × 0.20
monoclinic
P21/c
12.6180(3)
13.5390(3)
19.4530(4)
90
117.927(1)
90
C40H53F3N1O3P1Ru2S1Si1
845.02
0.15 × 0.12 × 0.12
monoclinic
P21/c
10.8889(3)
19.4246(5)
19.3800(7)
90
110.163(2)
90
C34H49F3N1O3P1Ru1S1Si1
768.93
0.15 × 0.15 × 0.12
monoclinic
P21/c
9.4515(3)
12.7981(3)
29.775(1)
90
97.460(1)
90
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
2936.2(1)
4
3847.9(2)
4
3571.1(2)
4
Z
F
calcd (g cm-3
)
1.495
1.459
1.430
µ (mm-1
2θ limit (deg)
)
0.709
0.588
0.626
55.02
52.74
43.92
-15 e h e 16
-15 e k e 17
-25 e l e 25
24121
-13 e h e 13
-24 e k e 22
-24 e l e 24
14004
-9 e h e 9
-13 e k e 13
-31 e l e 31
14029
total data collected
independent reflections
Rint
6729
7877
4348
0.0338
5874
6729/0/357
1.065
0.0319
0.0749
0.0545
5980
7877/19/563
1.035
0.0442
0.0947
0.0604
3193
4348/0/429
1.050
0.0444
0.0982
observed reflections
data/restraints/parameters
goodness-of-fit
R1 [Fo2 g 2σ(Fo )]
2
2
wR2 [Fo2 g -3σ( Fo )]
plexes that treatment with base can result in the deprotonation
of the indene backbone of 2b, thereby affording structurally
analogous neutral (κ2-P,N-2c)MLn species.11a,b,e Such formally
zwitterionic complexes are unusual in that the indenide unit in
2c functions as an uncoordinated anionic charge reservoir to
counterbalance the κ2-P,N-coordinated cationic MLn fragment,
rather than as a locale for metal binding.21 In light of recent
observations by Tilley and co-workers7 that formal charge
distribution can influence the reactivity of MdSi-H fragments,
and in the absence of reported zwitterionic RudSi species, we
became interested in preparing zwitterionic relatives of [5]+X-
(20) H-atom site exchange in related LnRu(H)(SiHPh2) species has been
observed: Gusev, D. G.; Nadasdi, T. T.; Caulton, K. G. Inorg. Chem. 1996,
35, 6772.
and [6]+X-. Treatment of [5]+B(C6F5)4 with KN(SiMe3)2 or
-
9
15858 J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007

RudSi Complexes
A R T I C L E S
Table 2. Crystallographic Data for 8 and 10 (X ) SO3CF3)
Scheme 3. Isomerization and Reactivity of the Base-Stabilized
RudSi Complexes [5]+X- and [6]+X-
8
10
empirical formula
formula weight
C
33H48N1P1Ru1Si1
C
34H49F3N1O3P1Ru1S1Si1
618.85
768.93
crystal dimensions
0.72 × 0.55 × 0.50
0.20 × 0.20 × 0.15
(mm3)
crystal system
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
monoclinic
P21/c
13.841(1)
14.239(1)
32.135(2)
90
93.372(1)
90
6322.3(8)
8
monoclinic
P21/c
11.1810(2)
17.8260(4)
17.8990(4)
90
97.091(1)
90
3540.2(1)
4
Z
F
calcd (g cm-3
)
1.300
0.606
1.443
0.631
µ (mm-1
)
2θ limit (deg)
55.02
52.74
-17 e h e 17
-18 e k e 18
-41 e l e 41
52274
14500
0.0208
-13 e h e 13
-22 e k e 20
-22 e l e 22
13245
7230
0.0414
total data collected
independent reflections
Rint
observed reflections
data/restraints/parameters
goodness-of-fit
R1 [Fo2 g 2σ(Fo2)]
wR2 [Fo2 g -3σ( Fo2)]
12268
14500/6/1048
1.113
0.0310
0.0806
6014
7230/243/491
1.293
0.0690
0.1539
-
rable to that of the precursory cationic complex [6]+SO3CF3
.
However, the somewhat contracted Si-N distance in 8 (1.924-
Table 3. Selected Interatomic Distances (Å) and Angles (deg) for
[4]+X-, [5]+X-, [6]+X-, 8, and 10 (X ) SO3CF3)
-
(2) Å) versus that found in [6]+SO3CF3 (1.955(4) Å) may
reflect increased basicity of the N-donor fragment in the formally
anionic ligand 2c in 8, relative to that of 2b featured in
[6]+SO3CF3-. In contrast to the pronounced bond length
alternation that is observed within the indene backbone of
[6]+SO3CF3-, the indenide unit in 8 exhibits a more delocalized
structure in keeping with a Hu¨ckel aromatic (10π-electron)
framework. However, in keeping with other crystallograph-
ically characterized complexes featuring κ2-P,N-2c,11 the short
P-C3 and C1-C2 distances found in 8 suggest that a reso-
c
d
d
[4]+
[5]+
[6]+
8
10e
Ru-P
2.2974(6) 2.2975(9) 2.293(2) 2.3193(5) 2.304(2)
Ru-Si
-
2.2811(9) 2.262(2) 2.2635(5) 2.291(2)
Ru-H1
Ru-H2
Si-H3
1.48(3)
1.59(4)
1.54(3)
-
1.60(5) 1.56(3)
1.52(5) 1.54(3)
1.52(5) 1.41(2)
1.525
1.565
-
-
-
-
-
-
Si‚‚‚N
1.988(3) 1.955(4) 1.924(2)
-
Si‚‚‚H1a
Si‚‚‚H2a
P-C3
2.13
2.19
2.13
2.14
2.16
2.24
2.12
2.08
1.815(2) 1.845(4) 1.858(5) 1.807(2) 1.881(6)
1.443(3) 1.485(4) 1.479(7) 1.488(3) 1.465(7)
1.506(3) 1.509(5) 1.501(7) 1.381(3) 1.547(8)
1.334(3) 1.366(4) 1.350(7) 1.442(3) 1.576(7)
1.484(3) 1.499(5) 1.502(7) 1.453(3) 1.519(8)
1.390(3) 1.401(5) 1.398(8) 1.411(3) 1.410(8)
1.396(3) 1.388(5) 1.385(8) 1.384(3) 1.383(9)
1.382(4) 1.382(6) 1.379(8) 1.400(4) 1.374(10)
1.393(4) 1.392(5) 1.375(8) 1.358(4) 1.388(10)
1.384(3) 1.387(5) 1.381(7) 1.415(3) 1.400(8)
1.504(3) 1.493(5) 1.475(7) 1.400(3) 1.503(8)
1.413(3) 1.396(5) 1.405(7) 1.439(3) 1.393(8)
N-C2
i
nance contributor featuring a Pr2PdC3 linkage and a formal
C1-C2
C2-C3
C3-C3a
C3a-C4
C4-C5
C5-C6
C6-C7
C7-C7a
C1-C7a
C3a-C7a
∑ angles at Sib
anionic charge on phosphorus must also be considered when
describing the electronic structure of this formally zwitterionic
complex.11,22
Reactivity of Base-Stabilized RudSi Complexes. Having
successfully prepared via double geminal Si-H bond activation
the base-stabilized Ru-hydrosilylene cations [6]+X- (X )
B(C6F5)4, SO3CF3), as well as the derived zwitterion 8, we
turned our attention to probing the reactivity of these species
in the context of the proposed G-T hydrosilylation mechanism.
In particular, we were interested in assessing how base-
stabilization of the RudSi unit in such complexes, as well as
the differing charge distribution in [6]+X- versus 8, might
influence stoichiometric and catalytic reactivity with alkenes.
In contrast to 1,3a no reaction was observed (1H and 31P NMR)
between either [6]+X- or 8 and 1-hexene or styrene (C6D5Br,
60 °C, 24 h). Moreover, negligible conversion was achieved in
hydrosilylation reactions employing PhSiH3 and either of these
olefins in the presence of 5 mol % [6]+X- or 8 (C6D5Br, 60
-
342.7
341.2
339.9
-
a Measured in the final refined structure. b Sum of the Ru-Si-R angles
(R ) C or H). c Ru-N 2.142(2) Å; Ru-C27 2.069(2) Å; N-C27 1.435(3)
Å; and N-C28 1.472(3) Å. d Shortest Si‚‚‚SO3CF3 distance >5 Å. e Si-
O1 1.77(1) Å and 1.88(2) Å for the two components of the disordered triflate
group; Si-C1 1.892(6) Å.
-
[6]+SO3CF3 with NaN(SiMe3)2 afforded cleanly (31P NMR)
the corresponding Cp*(µ-P,N-2c)(H)2RudSiRPh complex,
in the absence of observable products arising from deprotonation
of a Ru-H group; these hydrocarbon-soluble zwitterionic
silylenes were obtained in 69% (R ) Ph, 7) and 86% (R ) H,
8) isolated yield, respectively (Scheme 3). The connectivity
within 7 and 8 that was assigned initially on the basis of NMR
spectroscopic data was confirmed subsequently through the
crystallographic characterization of 8; an ORTEP12 diagram of
this complex is provided in Figure 1. With the exception of a
slight elongation of the Ru-P distance in 8, the connectivity
within the Ru coordination sphere of this zwitterion is compa-
(21) For discussions pertaining to the diverse coordination behavior of indenyl
ligands, see: (a) Bradley, C. A.; Lobkovsky, E.; Keresztes, I.; Chirik, P. J.
J. Am. Chem. Soc. 2005, 127, 10291. (b) Bradley, C. A.; Keresztes, I.;
Lobkovsky, E.; Young, V. G.; Chirik, P. J. J. Am. Chem. Soc. 2004, 126,
16937. (c) Zargarian, D. Coord. Chem. ReV. 2002, 233-234, 157. (d)
Stradiotto, M.; McGlinchey, M. J. Coord. Chem. ReV. 2001, 219-221,
311. (e) Lobanova, I. A.; Zdanovich, V. I. Russ. Chem. ReV. 1988, 57,
967.
(22) Izod, K. Coord. Chem. ReV. 2002, 227, 153.
9
J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007 15859

A R T I C L E S
Rankin et al.
°C, 48 h); under similar conditions, 0.5 mol % 1 affords >98%
conversion.3a These observations, when considered alongside
the established inability of Cp*(iPr3P)(H)2Ru-SiHPh(X) (X )
Cl, SO3CF3) to mediate such catalytic transformations,3a appear
to provide indirect evidence for the required intermediacy of
base-free RudSi species in alkene hydrosilylation catalysis
mediated by MdSi complexes such as 1.
currently known, the ancillary ligand 2b in [3]+X- can be
viewed as providing access to an operational equivalent of the
14-electron complex [Cp*Ru(κ1-2-NMe2-3-PiPr2-indene)]+X-
(analogous to 1a), as well as offering stabilization to the Rud
Si fragment generated following double geminal Si-H bond
activation of Ph2SiH2 or PhSiH3. Treatment of these new [Cp*-
(µ-P,N)(H)2RudSiRPh]+X- salts with base led to the formation
of novel zwitterionic complexes of the type Cp*(µ-P,N)(H)2Rud
SiRPh (7, R ) Ph; 8, R ) H) that feature a formally anionic
P,N-indenide ligand. In contrast to 1, both [6]+X- and 8 proved
unreactive toward 1-hexene and styrene and provided negligible
catalytic turnover in the attempted metal-mediated hydrosily-
lation of these substrates with PhSiH3, thereby providing further
experimental evidence for the required intermediacy of base-
free RudSi species in catalytic alkene hydrosilylation chemistry
mediated by complexes such as 1. However, isomerization of
In tracking the behavior of [6]+B(C6F5)4- in solution by use
of NMR techniques, slow isomerization to [9]+B(C6F5)4 was
-
noted. When employing Et2O-d10 as the solvent, this transfor-
mation was quantitative after 96 h, thereby allowing for the
spectroscopic characterization of this complex in situ; no further
reactivity was observed for [9]+B(C6F5)4-. The isomerization
of [6]+SO3CF3- to [9]+SO3CF3- was also observed in CH2Cl2,
C6D5Br, or PhF; when employing CH2Cl2 as the solvent, >90%
conversion was achieved after only 3 h (29Si and 31P NMR).
However, in continuing to monitor this solution over the course
-
the P,N-indene ligand backbone in [6]+SO3CF3 ultimately
of 48 h, the clean conversion of this mixture of [6]+SO3CF3
resulted in the formation of 10sthe apparent product of
intramolecular hydrosilylation involving the addition of a Rud
Si-H group across a CdC fragment within the indene ligand
backbone. Encouraged by the demonstrated propensity of
intermediates such as [3]+X- for intermolecular double geminal
Si-H bond activation, we are currently exploring the reactivity
of this and other coordinatively unsaturated metal complexes
supported by P,N-indene or indenide ligands with a range of
E-H-containing substrates, in an effort to identify new metal-
mediated E-H bond activation chemistry.
-
and [9]+SO3CF3- to 10 was detected. Complex 10 was obtained
in 96% isolated yield and was characterized spectroscopically.
1
Whereas H NMR data supported the identity of 10 as a Cp*-
(κ1-P,N)Ru(H)2 complex possessing C1 symmetry, the absence
of resonances attributable to an Si-H group or a vinylic indene
Csp2-H fragment suggested that 10 may result from the
intramolecular addition of Si-H across the styrene-like CdC
unit in a coordinatively unsaturated intermediate derived from
[9]+SO3CF3-. This proposal was confirmed on the basis of data
obtained from an X-ray diffraction study; an ORTEP12 diagram
of 10 is provided in Figure 1. Interestingly, the stoichiometric
transformation of [4]+SO3CF3- into [6]+SO3CF3- and ultimately
into 10 corresponds to the net triple Si-H bond activation of
PhSiH3, and is conceptually related to the stepwise conversion
of 1a into 1b, and subsequently 1c in the proposed G-T
hydrosilylation mechanism (Scheme 1). The lack of such
Experimental Section
General Considerations. All manipulations were conducted in the
absence of oxygen and water under an atmosphere of dinitrogen, either
by use of standard Schlenk methods or within an mBraun glovebox
apparatus, utilizing glassware that was oven-dried (130 °C) and
evacuated while hot prior to use. Celite (Aldrich) was oven-dried (130
°C) for 5 d and then evacuated for 24 h prior to use. The non-deuterated
solvents dichloromethane, THF, diethyl ether, benzene, hexanes, and
pentane were deoxygenated and dried by sparging with dinitrogen gas,
followed by passage through a double-column solvent purification
system provided by mBraun Inc. Dichloromethane, THF, and diethyl
ether were purified over two alumina-packed columns, while benzene,
hexanes, and pentane were purified over one alumina-packed column
and one column packed with copper-Q5 reactant. All solvents used
within the glovebox were stored over activated 4 Å molecular sieves.
C6D6, CD2Cl2, and PhF (Aldrich), as well as C6D5Br and Et2O-d10
(Cambridge Isotope Laboratories) were degassed by using a minimum
of three repeated freeze-pump-thaw cycles and then were dried over
4 Å molecular sieves for 24 h prior to use. PhSiH3 (Strem) was degassed
by using three repeated freeze-pump-thaw cycles, and Ph2SiH2
(Gelest, shipped under argon) was not degassed; both of these silanes
were dried over 4 Å molecular sieves for 24 h prior to use. Complexes
[4]+B(C6F5)4- and Cp*RuCl(κ2-2-NMe2-3-PiPr2-indene) were prepared
by employing published procedures.11e All other commercial reagents
were obtained from Aldrich and were used as received, with the
exceptions of NaN(SiMe3)2, KN(SiMe3)2, and TlSO3CF3 (Strem) that
were dried in vacuo for 24 h prior to use. Unless otherwise stated,
NMR characterization data were collected at 300 K on a Bruker AV-
500 spectrometer operating at 500.1 (1H) MHz, 125.8 (13C) MHz, 99.4
(29Si) MHz, and 202.5 (31P) MHz with chemical shifts reported in parts
per million downfield of SiMe4 (for 1H, 13C, and 29Si), or 85% H3PO4
in D2O (for 31P). In some cases slightly fewer than expected independent
1H or 13C NMR resonances were observed (despite prolonged data
reactivity for [9]+B(C6F5)4 suggests that the conversion of
-
-
[9]+SO3CF3 into 10 is perhaps enabled by the coordinating
ability of triflate. Furthermore, given the lack of inter- or intra-
-
molecular hydrosilylation chemistry observed for [6]+SO3CF3
,
it is plausible that isomerization to [9]+SO3CF3- promotes Si-N
dissociation and/or provides more advantageous positioning of
the RudSi-H unit for intramolecular addition to the alkene
fragment.
Summary and Conclusions
We have demonstrated herein that reactive, coordinatively
unsaturated intermediates of the type [Cp*Ru(κ2-2-NMe2-3-Pi-
Pr2-indene)]+X- ([3]+X-; X ) B(C6F5)4 or SO3CF3) are capable
of extruding silylene fragments from Ph2SiH2 and PhSiH3 in a
stoichiometric fashion by way of double geminal Si-H bond
activation, thereby affording complexes of the type [Cp*(µ-
P,N)(H)2RudSiRPh]+X- ([5]+X-, R ) Ph; [6]+X-, R ) H).
These transformations represent the first documented examples
of the direct formation of RudSi species via double geminal
Si-H bond activation of an organosilane. The observation of
such reactivity involving PhSiH3 leading to [6]+X- is notewor-
thy, in that it provides persuasive empirical support for a key
step in the proposed Glaser-Tilley hydrosilylation mechanism
employing [Cp*(iPr3P)(H)2RudSiHPh‚OEt2]+B(C6F5)4- (1) as
a precatalyst (i.e., the conversion of 1a to 1b/1b′ in Scheme
1).3 Although mechanistic details regarding the formation of
the base-stabilized RudSi species [5]+X- and [6]+X- are not
acquisition times), and 13C resonances associated with B(C6F5)4 and
-
SO3CF3 were not assigned. H and 13C NMR chemical shift assign-
-
1
ments are given on the basis of data obtained from 13C-DEPT, 1H-1H
9
15860 J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007

RudSi Complexes
A R T I C L E S
1
1
COSY, H-13C HSQC, and H-13C HMBC NMR experiments. 29Si
NMR chemical shift assignments are given on the basis of data obtained
from 1H-29Si HMQC (1H-coupled experiments were employed in the
) 32.0 Hz, 2H, Ru(H)2); 13C{1H} NMR (CD2Cl2): δ 161.9 (d, 2JPC
)
4.9 Hz, C2), 142.5 (Si-aryl-C), 137.2 (m, C3a or C7a), 136.0 (m, 2
Si-aryl-CHs), 135.5 (2 Si-aryl-CHs), 135.3 (C7a or C3a), 134.2 (aryl-
CH), 130.4 (2 Si-aryl-CHs), 128.2 (2 Si-aryl-CHs), 128.1 (2 Si-aryl-
determination of JSiH values) as well as H-29Si HMBC (J-HMBC23
experiments were employed in the determination of JSiH values for n
> 1) experiments. Elemental analyses were performed by Canadian
Microanalytical Service Ltd., Delta, British Columbia, Canada. Note:
With the exception of [4]+SO3CF3 and 10, all complexes reported
herein were found to be thermally unstable, even when stored under
dinitrogen within a glovebox; storage of these complexes at or below
-35 °C is recommended.
1
1
n
1
CHs), 127.1 (m, aryl-CH), 124.0 (2 aryl-CHs), 115.1 (d, JPC ) 4.9
Hz, C3), 98.5 (C5Me5), 52.3 (broad m, NMe2), 39.8 (d, 3JPC ) 7.0 Hz,
C1), 30.9 (d, 1JPC ) 24.2 Hz, P(CHMeaMeb)2), 20.4 (P(CHMeaMeb)2),
19.0 (P(CHMeaMeb)2), 11.2 (C5Me5); 31P{1H} NMR (CD2Cl2): δ 73.7;
-
2
29Si{1H} NMR (CD2Cl2): δ 106.7 (1H-29Si HMBC), JSiH ) 3.0 Hz
(J-HMBC).
Synthesis of [5]+SO3CF3-. To a glass vial containing a magnetically
Synthesis of [4]+SO3CF3-. To a glass vial containing a magnetically
stirred suspension of Cp*RuCl(κ2-2-NMe2-3-PiPr2-indene) (0.50 g, 0.91
mmol) in THF (10 mL), was added all at once solid TlSO3CF3 (0.32
g, 0.91 mmol). The addition caused an immediate color change from
red-orange to brown and was accompanied by the precipitation of an
off-white solid. The vial was then sealed with a PTFE-lined cap, and
the solution was stirred magnetically for 1 h. Analysis of 31P NMR
data collected on an aliquot of this crude reaction mixture solution
indicated the quantitative formation of [4]+SO3CF3-. The mixture was
then filtered through Celite, yielding a yellow-brown solution. The
separated off-white precipitate was washed with THF (2 × 3 mL)
followed by CH2Cl2 (2 × 3 mL), and the filtrate from the washings
was combined with the filtered reaction mixture solution. The solvents
and other volatiles were then removed in vacuo, and the resulting oily,
yellow-brown solid was washed with pentane (3 × 1.5 mL). The solid
residue was then extracted with CH2Cl2 (6 mL) and filtered through
Celite. After removal of the solvent in vacuo, the residue was washed
with pentane (2 × 3 mL). The solid was then dried in vacuo to yield
-
stirred solution of [4]+SO3CF3 (0.37 g, 0.55 mmol) in PhF (8 mL),
was added Ph2SiH2 (1.15 mL, 5.53 mmol) all at once by way of an
Eppendorf micropipet. The vial was then sealed with a PTFE-lined
cap and mixed manually by inversion several times. After 4 d, the
mixture had lightened slightly from light brown to yellow-brown.
Analysis of an aliquot of this solution by use of 31P NMR methods
indicated the presence of several P-containing products. After returning
the NMR tube contents to the reaction vial, the mixture was concen-
trated in vacuo to approximately 3 mL in order to induce crystallization.
After 24 h, the colorless crystalline solid that had settled in the vial
was isolated by transferring the supernatant solution to a new glass
vial by using a Pasteur pipet; this solution was then concentrated in
vacuo in order to induce further crystallization. After repeating this
procedure, the isolated crops of crystals were then combined, dried in
vacuo, and washed with PhF (3 × 1.5 mL), and then pentane (3 × 1.5
mL), to yield [5]+SO3CF3- as a white solid (0.18 g, 0.22 mmol, 39%).
Anal. Calcd for C40H53PNSiF3SO3Ru1: C, 56.85; H, 6.33; N, 1.66.
-
Found: C, 56.49; H, 6.27; N, 1.25. A single crystal of [5]+SO3CF3
[4]+SO3CF3 as an analytically pure, pale-brown solid (0.57 g, 0.86
-
grown from an undisturbed PhF solution of the initially prepared
reaction mixture stored at ambient temperature proved suitable for X-ray
analysis. Complex [5]+SO3CF3- was found to be either insoluble in or
reactive with all common solvents; for example, THF, CH2Cl2, acetone,
C6D5Br, PhF, and CH3CN all proved unsatisfactory.
mmol, 94%). Anal. Calcd for C28H41PNF3SO3Ru: C, 50.90; H, 6.26;
N, 2.12. Found: C, 50.63; H, 5.89; N, 2.23. In solution, complex
[4]+SO3CF3 exhibits dynamic behavior analogous to that described
-
previously for [4]+B(C6F5)4- 11e 1H NMR (CD2Cl2): δ 7.42 (d, 3JHH
. )
7.5 Hz, 1H, C4-H or C7-H), 7.36 (m, 1H, C7-H or C4-H), 7.32-7.26
(m, 2H, C5-H and C6-H), 3.74 (s, 2H, C1(H)2), 2.66 (m, 2H, P(CHMea-
Meb)2), 1.89 (s, 15H, C5Me5), 1.19-1.00 (m, 12H, P(CHMeaMeb)2),
0.87 (broad s, 6H, NMe2); 13C{1H} NMR (CD2Cl2): δ 173.0 (m, C2),
145.2 (broad m, C3a or C7a), 138.8 (broad m, C7a or C3a), 127.9 (C5
Synthesis of [6]+B(C6F5)4-. To a glass vial containing a magnetically
-
stirred suspension of [4]+B(C6F5)4 (0.15 g, 0.12 mmol) in Et2O (4
mL) was added PhSiH3 (15 µL, 0.12 mmol) all at once via an Eppendorf
micropipet. The vial was then sealed with a PTFE-lined cap, and the
solution was stirred magnetically for 30 min. During this time period,
the suspension had become a yellow solution. Analysis of 31P NMR
data collected on an aliquot of this solution indicated the quantitative
formation of [6]+B(C6F5)4-. The solvent and other volatiles were then
removed in vacuo yielding an oily, yellow foam. This material was
then washed with pentane (5 × 3 mL), and the product was dried in
or C6), 127.2 (C6 or C5), 125.8 (C4 or C7), 122.9 (C7 or C4), 100.7
1
(broad m, C5Me5), 52.3 (NMe2), 35.6 (broad m, C1), 24.9 (d, JPC
)
28.6 Hz, P(CHMeaMeb)2), 18.7-18.6 (m, P(CHMeaMeb)2), 11.4 (C5Me5);
31P{1H} NMR (CD2Cl2): δ 83.3. A single crystal of [4]+SO3CF3
-
grown from a concentrated Et2O solution at ambient temperature proved
suitable for X-ray analysis.
vacuo to yield [6]+B(C6F5)4 as an analytically pure, pale-yellow
-
Synthesis of [5]+B(C6F5)4-. To a glass vial containing a magnetically
powder (0.16 g, 0.12 mmol, 94%). Anal. Calcd for C57H49PNSiBF20-
Ru: C, 52.71; H, 3.80; N, 1.08. Found: C, 52.77; H, 3.58; N, 0.94. 1H
stirred suspension of [4]+B(C6F5)4 (0.15 g, 0.12 mmol) in Et2O (4
-
mL), was added Ph2SiH2 (222 µL, 1.2 mmol) all at once by way of an
3
NMR (CD2Cl2): δ 7.91 (d, JHH ) 7.5 Hz, 1H, C4-H or C7-H), 7.69
Eppendorf micropipet. The vial was then sealed with a PTFE-lined
3
(d, JHH ) 6.5 Hz, 2H, 2 Si-aryl-Hs), 7.49-7.35 (m, 6H, 3 aryl-Hs
cap, and the mixture was stirred magnetically for 48 h. Analysis of 31
P
and 3 Si-aryl-Hs), 5.56 (apparent t, J ) 8.0 Hz, 1H, Si-H), 3.77-
3.57 (m, 2H, C(Ha)(Hb)), 3.33 (s, 3H, NMea), 3.24 (m, 1H, P(CHMea-
Meb)), 2.89 (m, 1H, P(CHMecMed)), 2.86 (s, 3H, NMeb), 1.92 (s, 15H,
C5Me5), 1.26-1.14 (m, 6H, P(CHMeaMeb) and P(CHMecMed)), 0.99
(d of d, 3JPH ) 15.5 Hz, 3JHH ) 6.5 Hz, 3H, P(CHMeaMeb)), 0.96 (d of
d, 3JPH ) 16.5 Hz, 3JHH ) 7.0 Hz, 3H, P(CHMecMed)), -9.91 (d, 2JPH
) 34.4 Hz, 1H, Ru-Ha), -11.26 (apparent d of d, J ) 32.5 Hz, J )
4.0 Hz, 1H, Ru-Hb); 13C{1H} NMR (CD2Cl2): δ 160.4 (d, 2JPC ) 5.3
Hz, C2), 139.7 (m, Si-aryl-C), 137.7 (m, C3a or C7a), 135.7 (m, C7a
NMR data collected on this solution indicated the quantitative formation
of [5]+B(C6F5)4-. The solvent and other volatiles were then removed
in vacuo, yielding an oily, brown-yellow solid. The solid was then
washed with pentane (5 × 3 mL), and the product was dried in vacuo
to yield [5]+B(C6F5)4- as an analytically pure, off-white powder (0.14
g, 0.098 mmol, 82%). Anal. Calcd for C63H53PNSiBF20Ru: C, 55.03;
1
H, 3.89; N, 1.02. Found: C, 55.30; H, 4.11; N, 1.01. H NMR (CD2-
3
Cl2): δ 7.93-7.89 (broad s, 2H, Si-aryl-Hs), 7.86 (d, JHH ) 7.5 Hz,
1H, C4-H or C7-H), 7.62-7.60 (m, 2H, Si-aryl-Hs), 7.57 (m, 1H, aryl-
H), 7.54 (m, 1H, aryl-H), 7.52-7.50 (m, 4H, Si-aryl-Hs), 7.45-7.40
(m, 3H, 2 Si-aryl-Hs and aryl-H), 3.87 (s, 2H, C1(H)2), 3.03 (m, 2H,
P(CHMeaMeb)), 2.84 (s, 6H, NMe2), 1.66 (s, 15H, C5Me5), 1.25 (d of
1
or C3a), 135.2 (2 Si-aryl-CHs), 134.9 (d, JPC ) 36.0 Hz, C3), 131.2
(Si-aryl-CH), 129.0 (2 Si-aryl-CHs), 127.8 (C5 or C6), 127.7 (aryl-
CH), 124.5 (aryl-CH), 124.3 (C4 or C7), 98.5 (C5Me5), 56.7 (NMea),
3
1
53.5 (NMeb), 39.5 (d, JPC ) 6.0 Hz, C1), 31.3 (d, JPC ) 23.5 Hz,
3
3
d, JPH ) 18.0 Hz, JHH ) 6.5 Hz, 6H, P(CHMeaMeb)2), 1.02 (d of d,
1
P(CHMecMed)), 30.6 (d, JPC ) 26.4 Hz, P(CHMeaMeb)), 21.0
3JPH ) 16.0 Hz, JHH ) 7.0 Hz, 6H, P(CHMeaMeb)2), -10.24 (d, JPH
3
2
(P(CHMecMed)), 20.7-20.6 (m, (P(CHMeaMeb) and P(CHMecMed)),
2
19.3 (d, JPC ) 7.0 Hz, P(CHMeaMeb)), 11.4 (C5Me5); 31P{1H} NMR
(23) J-HMBC: Meissner, A.; Sørensen, O. W. Magn. Reson. Chem. 2001, 39,
49.
(CD2Cl2): δ 79.6; 29Si{1H} NMR (CD2Cl2): δ 112.0 (1H-29Si HMBC/
9
J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007 15861

A R T I C L E S
Rankin et al.
1
2
2
HMQC), JSiH ) 191.4 Hz (1H-coupled 1H-29Si HMQC), JSiH not
P(CHMeaMeb)2), -10.45 (d, JPH ) 30.0 Hz, 2H, Ru(H)2); 13C{1H}
NMR (C6D6): δ 149.6 (d, 2JPC ) 12.9 Hz, C2), 135.7 (Si-aryl-C), 135.2
(m, Si-aryl-CH), 132.3 (C7a), 129.5 (Si-aryl-CH), 129.0 (m, C3a), 128.0
(overlapping Si-aryl-CHs), 127.8 (Si-aryl-CH), 127.3 (overlapping Si-
aryl-CHs), 121.0 (C4), 120.1 (C7), 115.7 (C6), 114.7 (C5), 96.5 (C5-
detected by J-HMBC.
Synthesis of [6]+SO3CF3-. To a glass vial containing a magnetically
stirred suspension of [4]+SO3CF3- (0.31 g, 0.47 mmol) in PhF (7 mL)
was added PhSiH3 (58 µL, 0.47 mmol) all at once via Eppendorf
micropipet. The vial was then sealed with a PTFE-lined cap, and the
solution was stirred magnetically for 30 min. During this time period,
the suspension had lightened from a brown solution to one yellow in
color. Analysis of 31P NMR data collected on an aliquot of this solution
indicated the quantitative formation of [6]+SO3CF3-. The solvent and
other volatiles were then removed in vacuo, yielding an oily, yellow
solid. The solid was then washed with pentane (3 × 3 mL), and the
3
1
Me5), 92.9 (d, JPC ) 6.7 Hz, C1), 85.0 (d, JPC ) 62.6 Hz, C3), 50.2
(broad m, NMe2), 21.5 (m, P(CHMeaMeb)2), 20.2 (P(CHMeaMeb)2), 19.2
(broad m, P(CHMeaMeb)2), 11.0 (C5Me5); 31P{1H} NMR (C6D6): δ
58.1; 29Si{1H} NMR (C6D6): δ 96.3 (1H-29Si HMBC), 2JSiH ) 6.2 Hz
(J-HMBC).
Synthesis of 8. To a glass vial containing a magnetically stirred
suspension of [6]+SO3CF3 (0.20 g, 0.26 mmol) in PhF (8 mL) was
-
-
product was dried in vacuo to yield [6]+SO3CF3 as an analytically
added solid NaN(SiMe3)2 (0.050 g, 0.027 mmol) all at once. The
addition of base resulted in an immediate darkening of the mixture
from yellow to brown. The vial was then sealed with a PTFE-lined
pure, fluffy, off-white solid (0.34 g, 0.45 mmol, 95%). Anal. Calcd
for C34H49PNSiF3SO3Ru: C, 53.10; H, 6.42; N, 1.82. Found: C, 52.71;
H, 6.65; N, 1.80. H NMR (C6D5Br): δ 7.57 (d, JHH ) 8.0 Hz, 1H,
C4-H or C7-H), 7.41-7.37 (m, 2H, 2 Si-aryl-Hs), 7.17-7.09 (m, 5H,
cap, and the solution was stirred magnetically for 1 h. Analysis of 31
P
1
3
NMR data collected on this solution indicated the quantitative formation
of 8. The solution was then filtered through Celite, and the PhF solvent
and other volatiles were removed in vacuo, yielding an oily, yellow
solid. The solid was then washed with pentane (3 × 1.5 mL) and dried
in vacuo. The residue was then treated with benzene (5 mL), and the
resulting mixture was filtered through Celite. The filtrate was then
stripped of benzene in vacuo, and the residual solid was subsequently
washed with pentane (3 × 3 mL). After removal of traces of pentane
in vacuo, 8 was isolated as an analytically pure, off-white powder (0.14
g, 0.22 mmol, 86%). Anal. Calcd for C33H48PNSiRu: C, 64.04; H,
7.82; N, 2.26. Found: C, 63.93; H, 8.16; N, 2.17. 1H NMR (C6D6): δ
8.19 (d, JHH ) 8.5 Hz, 1H, C4-H or C7-H), 7.95 (d, JHH ) 7.5 Hz,
1H, C7-H or C4-H), 7.50-7.47 (m, 2H, Si-aryl-Hs), 7.36 (m, 1H, C5-H
or C6-H), 7.30 (m, 1H, C6-H or C5-H), 7.06-7.03 (m, 3H, Si-aryl-
Hs), 6.17 (d, J ) 4.5 Hz, 1H, C1-H), 5.44 (apparent t, J ) 3.5 Hz, 1H,
Si-H), 3.68 (m, 1H, P(CHMeaMeb)), 2.92 (s, 3H, NMea), 2.56 (s, 3H,
NMeb), 2.31 (m, 1H, P(CHMecMed)), 1.70 (s, 15H, C5Me5), 1.29 (d of
3
2 aryl-Hs and 3 Si-aryl-Hs), 7.01 (t, JHH ) 7.5 Hz, 1H, C5-H or C6-
H), 5.10 (apparent t, J ) 4.0 Hz, 1H, Si-H), 4.21 (apparent d, J )
24.5 Hz, 1H, C(Ha)(Hb)), 3.19-3.12 (m, 4H, C(Ha)(Hb) and NMea),
2.78 (m, 1H, P(CHMeaMeb)), 2.67 (s, 3H, NMeb), 2.47 (m, 1H,
P(CHMecMed)), 1.50 (s, 15H, C5Me5), 0.81-0.73 (m, 6H, P(CHMea-
Meb) and P(CHMecMed)), 0.64 (d of d, 3JPH ) 15.5 Hz, 3JHH ) 6.5 Hz,
3H, P(CHMeaMeb)), 0.44 (d of d, 3JPH ) 17.0 Hz, 3JHH ) 7.0 Hz, 3H,
2
P(CHMecMed)), -10.38 (d, JPH ) 34.0 Hz, 1H, Ru-Ha), -11.74
(apparent d of d, J ) 32.5 Hz, J ) 3.0 Hz, 1H, Ru-Hb); 13C{1H}
NMR (C6D5Br): δ 162.2 (d, 2JPC ) 5.1 Hz, C2), 142.0 (C3a or C7a),
140.1 (Si-aryl-C), 138.5 (d, JPC ) 5.8 Hz, C7a or C3a), 135.0 (2 Si-
3
3
1
aryl-CHs), 132.4 (d, JPC ) 38.2 Hz, C3), 130.6 (Si-aryl-CH), 128.6
(2 Si-aryl-CHs), 127.2 (C5 or C6), 127.0 (aryl-CH), 124.9 (aryl-CH),
123.4 (C4 or C7), 97.5 (C5Me5), 56.2 (NMea), 53.1 (NMeb), 39.8 (d,
3JPC ) 6.0 Hz, C1), 30.9 (d, 1JPC ) 23.7 Hz, P(CHMecMed)), 30.0 (d,
1JPC ) 26.5 Hz, P(CHMeaMeb)), 20.8 (d, JPC ) 9.4 Hz, P(CHMea-
2
3
3
Meb) or P(CHMecMed)), 20.7 (P(CHMecMed)), 20.5 (P(CHMeaMeb)),
19.0 (d, 2JPC ) 6.8 Hz, P(CHMecMed) or P(CHMeaMeb)), 11.4 (C5Me5);
31P{1H} NMR (C6D5Br): δ 76.6; 29Si{1H} NMR (C6D5Br): δ 107.2
d, JPH ) 14.0 Hz, JHH ) 7.0 Hz, 3H, P(CHMecMed)), 1.13 (d of d,
3JPH ) 16.5 Hz, JHH ) 7.0 Hz, 3H, P(CHMecMed)), 1.02-0.95 (m,
3
2
6H, P(CHMeaMeb)), -9.86 (d, JPH ) 31.5 Hz, 1H, Ru-Ha), -11.37
(1H-29Si HMBC/HMQC), JSiH ) 195.0 Hz (1H-coupled 1H-29Si
(apparent d of d, J ) 30.0 Hz, J ) 3.0 Hz, 1H, Ru-Hb); 13C{1H}
NMR (C6D6): δ 145.1 (d, JPC ) 13.7 Hz, C2), 143.5 (Si-aryl-C),
134.7 (Si-aryl-CHs), 133.5 (d, JPC ) 2.9 Hz, C3a or C7a), 130.6
(d, JPC ) 10.4 Hz, C7a or C3a), 129.4 (Si-aryl-CH), 127.9 (Si-aryl-
CHs), 121.7 (C4 or C7), 120.9 (C7 or C4), 117.4 (C5 or C6), 116.2
1
HMQC), 2JSiH not detected by J-HMBC. A single crystal of [6]+SO3CF3-
grown from a mixture of PhF and hexanes at ambient temperature
proved suitable for X-ray analysis.
Synthesis of 7. To a glass vial containing a magnetically stirred
oily suspension of [5]+B(C6F5)4- (0.19 g, 0.14 mmol) in C6H6 (5 mL)
was added solid KN(SiMe3)2 (0.027 g, 0.15 mmol) all at once. The
addition of base resulted in an immediate darkening of the mixture
from yellow to brown. The vial was then sealed with a PTFE-lined
3
(C6 or C5), 95.8 (C5Me5), 94.2 (d, JPC ) 7.3 Hz, C1), 81.4 (d,
1JPC ) 70.3 Hz, C3), 59.1 (NMea), 52.9 (NMeb), 33.6 (d, JPC
)
1
1
25.9 Hz, P(CHMecMed)), 27.3 (d, JPC ) 32.5 Hz, P(CHMeaMeb)),
21.0 (m, P(CHMecMed)), 20.4 (apparent s, P(CHMecMed) and
P(CHMeaMeb)), 19.9 (d, 2JPC ) 6.7 Hz, P(CHMeaMeb)), 11.4 (C5Me5);
31P{1H} NMR (C6D6): δ 56.6; 29Si{1H} NMR (C6D6): δ 97.7
cap, and the solution was stirred magnetically for 2 h. Analysis of 31
P
NMR data collected on this solution indicated the quantitative formation
of 7. The solution was then filtered through Celite, and the benzene
solvent and other volatiles were removed in vacuo, yielding an oily,
yellow solid. The solid was then washed with pentane (3 × 1.5 mL)
and dried in vacuo. The residue was then treated with benzene (5 mL),
and the resulting mixture was filtered through Celite. The filtrate was
then stripped of benzene in vacuo, and the residual solid was
subsequently washed with pentane (3 × 3 mL) and dried again in vacuo.
This benzene extraction process was repeated twice more. Analysis of
19F NMR (C6H6) collected on a sample of the residual powder confirmed
the absence of KB(C6F5)4 or other F-containing species. After removal
of volatiles in vacuo, 7 was isolated as an analytically pure, pale-yellow
powder (0.067 g, 0.096 mmol, 69%). Anal. Calcd for C39H52PNSiRu:
(1H-29Si HMBC/HMQC), JSiH ) 179.0 Hz (1H-coupled 1H-29Si
1
HMQC), 2JSiH ) 3.6 Hz (J-HMBC). A single crystal of 8 grown from
a mixture of benzene and pentane at ambient temperature proved
suitable for X-ray analysis.
Synthesis of [9]+B(C6F5)4-. A sample of [6]+B(C6F5)4 (0.019 g)
-
in 0.8 mL of Et2O-d10 was left undisturbed in an NMR tube in the
glovebox for 96 h. Analysis of 31P NMR data collected on this solution
indicated the quantitative formation of [9]+B(C6F5)4-. 1H NMR (Et2O-
d10): δ 7.79-7.76 (m, 2H, Si-aryl-Hs), 7.60 (d, JHH ) 7.5 Hz, 1H,
C4-H or C7-H), 7.51-7.46 (m, 3H, Si-aryl-Hs), 7.37-7.28 (m, 3H,
aryl-Hs), 6.50 (s, 1H, C3-H), 5.63 (m, 1H, Si-H), 3.98 (d, JPH
10.5 Hz, 1H, C1-H), 3.29 (s, 3H, NMea), 2.86 (s, 3H, NMeb), 2.44 (m,
1H, P(CHMeaMeb)), 2.09 (m, 1H, P(CHMecMed)), 1.77 (s, 15H, C5-
3
2
)
1
C, 67.40; H, 7.54; N, 2.02. Found: C, 67.14; H, 7.67; N, 1.68. H
NMR (C6D6): δ 7.86 (d, JHH ) 8.5 Hz, 1H, C4-H), 7.76-7.74 (m,
3
3
Me5), 1.62-1.54 (m, 6H, P(CHMecMed)), 0.99 (d of d, JPH ) 17.5
3
2H, Si-aryl-Hs), 7.48 (d, JHH ) 7.5 Hz, 1H, C7-H), 7.23-7.17 (m,
Hz, 3JHH ) 7.5 Hz, 3H, P(CHMeaMeb)), 0.33 (d of d, 3JPH ) 17.0 Hz,
8H, Si-aryl-Hs), 6.78 (t, 3JHH ) 8.0 Hz, 1H, C6-H), 6.72 (t, 3JHH ) 7.0
Hz, 1H, C5-H), 6.17 (d, J ) 3.5 Hz, 1H, C1-H), 2.64 (s, 6H, NMe2),
3JHH ) 6.5 Hz, 3H, P(CHMeaMeb)), -10.60 (d, JPH ) 32.8 Hz, 1H,
2
Ru-Ha), -11.37 (apparent d of d, J ) 28.0 Hz, J ) 5.5 Hz, 1H, Ru-
Hb); 13C{1H} NMR (Et2O-d10): δ 152.8 (m, C2), 141.5 (m, C3a or
C7a), 141.2 (m, C7a or C3a), 138.2 (m, Si-aryl-C), 136.7-136.6 (m,
3
3
1.44 (s, 15H, C5Me5), 1.13 (d of d, JPH ) 15.5 Hz, JHH ) 6.0 Hz,
6H, P(CHMeaMeb)2), 1.07 (m, 2H, P(CHMeaMeb)2), 0.97 (m, 6H,
9
15862 J. AM. CHEM. SOC. VOL. 129, NO. 51, 2007

RudSi Complexes
A R T I C L E S
2
2 Si-aryl-CHs), 132.1 (Si-aryl-CH), 129.5 (m, 2 Si-aryl-CHs), 128.7
(aryl-CH), 127.0 (aryl-CH), 126.8 (d, JPC ) 5.4 Hz, C3), 126.4 (C4
based on Fo2 g -3σ(Fo ). With the exception of the Ru-H and Si-H
(the positions of which were located in the difference map and refined,
except for 10) all H-atoms were added at calculated positions and
refined by use of a riding model employing isotropic displacement
parameters based on the isotropic displacement parameter of the
attached atom. In the solution and refinement of [5]+X-, one of the
carbon atoms of an isopropyl group was modeled as being dis-
ordered over two positions, with site occupancy factors that refined
to 0.64(1) and 0.36(1). The atoms of the triflate anion in [5]+X-
were modeled successfully as being fully disordered into two super-
imposed sets of positions, with group site occupancy factors that re-
fined to 0.58(3) and 0.42(3). In the solution and refinement of 10, the
program XHYDEX27 was used to predict the positions of the Ru-H
atoms; these positions were fixed during the refinement process. The
atoms of the triflate group in 10 were modeled successfully as being
fully disordered into two superimposed sets of positions by use of the
SIMU, DELU, and SAME constraints, with group site occupancy
factors that refined to 0.567(4) and 0.433(4). Additional experimental
details related to the crystallographic characterization of [4]+X-, [5]+X-,
[6]+X-, and 10 are provided in the accompanying crystallographic
information file.
3
or C7), 124.1 (aryl-CH), 98.2 (C5Me5), 53.7 (NMeb), 52.4 (NMea), 48.1
(d, 1JPC ) 15.1 Hz, C1), 30.9 (d, 1JPC ) 17.6 Hz, P(CHMecMed)), 28.6
(d, 1JPC ) 24.0 Hz, P(CHMeaMeb)), 20.4 (P(CHMecMed) or P(CHMec-
Med)), 19.8 (P(CHMeaMeb)), 19.7 (d, 2JPC ) 7.0 Hz, P(CHMecMed) or
P(CHMecMed)), 17.7 (d, 2JPC ) 5.2 Hz, P(CHMeaMeb)), 11.4 (C5Me5);
31P{1H} NMR (Et2O-d10): δ 87.2; 29Si{1H} NMR (Et2O-d10): δ 111.6
1
(1H-29Si HMBC/HMQC), JSiH ) 192.0 Hz (1H-coupled 1H-29Si
HMQC).
Synthesis of 10. To a glass vial charged with [6]+SO3CF3 (0.080
-
g, 0.10 mmol) was added CH2Cl2 (4 mL). The resultant brown mixture
was then sealed with a PTFE-lined cap. Analysis of 31P NMR data
collected on this solution after 3 h indicated ∼90% isomerization of
the starting material [6]+SO3CF3 to [9]+SO3CF3-; this structural
-
1
assignment was made by comparison to diagnostic H, 29Si, and 31P
NMR data for [9]+B(C6F5)4-. Selected NMR data for [9]+SO3CF3
:
-
1
Diagnostic H NMR shifts (CD2Cl2): δ 6.49 (s, 1H, C3-H), 5.64 (m,
2
1H, Si-H), 4.00 (d, JPH ) 10 Hz, 1H, C1-H); 31P{1H} NMR (CD2-
Cl2): δ 87.2; 29Si{1H} NMR (CD2Cl2): δ 108.4 (1H-29Si HMBC/
HMQC), 1JSiH ) 197.1 Hz (1H-coupled 1H-29Si HMQC). Analysis of
31P NMR data collected on this solution after 12 h revealed the presence
Crystallographic Solution and Refinement Details for 8. Crystal-
lographic data were obtained at 193((2) K on a Bruker PLATFORM/
SMART 1000 CCD diffractometer using a graphite-monochromated
Mo KR (λ ) 0.71073 Å) radiation, employing a sample that was
mounted in inert oil and transferred to a cold gas stream on the
diffractometer. Programs for diffractometer operation, data collection,
data reduction, and absorption correction (including SAINT and
SADABS) were supplied by Bruker. The structures were solved by
-
of [9]+SO3CF3 and a new P-containing product (10) (∼ 1:3 ratio).
After a total of 48 h, only 10 was observed (31P NMR). The vial contents
were then filtered through Celite and were stripped of solvent and other
volatile materials in vacuo. The residual solid was subsequently washed
with pentane (3 × 3 mL). After removal of traces of pentane in vacuo,
10 was isolated as an analytically pure, pale-brown powder (0.077 g,
0.10 mmol, 96%). C34H49PNSiSO3F3Ru: C, 53.10; H, 6.42; N, 1.82.
1
Found: C, 52.91; H, 6.55; N, 1.71. H NMR (CD2Cl2): δ 7.47 (d,
using a Patterson search/structure expansion, and refined by using a
3JHH ) 7.0 Hz, 2H, Si-aryl-Hs), 7.39-7.32 (m, 3H, Si-aryl-Hs), 7.07
full-matrix least-squares procedures (on F2) with R1 based on Fo
g
2
3
(m, 1H, C4-H or C7-H), 6.91 (t, JHH ) 7.0 Hz, 1H, C5-H or C6-H),
2
2
2
2σ(Fo ) and wR2 based on Fo g -3σ(Fo ). Anisotropic displacement
parameters were employed throughout for the non-H atoms. With the
exception of the Ru-H and Si-H (the positions of which were located
in the difference map and refined) all H-atoms were added at calcu-
lated positions and refined by use of a riding model employing iso-
tropic displacement parameters based on the isotropic displacement
parameter of the attached atom. In the course of the solution and
refinement process, a model featuring two crystallographically inde-
pendent molecules of 8 in the asymmetric unit was employed
successfully. Since one of these molecules is fully disordered into two
superimposed sets of positions (55:45 ratio), only details of the
nondisordered crystallographically independent molecule are discussed
in the text. Additional experimental details related to the crystallographic
characterization of 8 are provided in the accompanying crystallographic
information file.
3
3
6.77 (t, JHH ) 7.5 Hz, 1H, C6-H or C5-H), 5.81 (d, JHH ) 7.5 Hz,
1H, C7-H or C4-H), 3.88 (m, 1H, C2-H), 3.54 (d, 2JPH ) 10.5 Hz, 1H,
C3-H), 2.82 (s, 1H, C1-H), 2.29 (m, 1H, P(CHMeaMeb)), 2.11 (m, 1H,
P(CHMecMed)), 2.01 (broad s, 6H, NMe2), 1.75 (s, 15H, C5Me5), 1.52
(d of d, 3JPH ) 15.5 Hz, 3JHH ) 7.5 Hz, 3H, P(CHMecMed)), 1.44 (d of
3
3
d, JPH ) 11.5 Hz, JHH ) 7.0 Hz, 3H, P(CHMecMed)), 1.11 (d of d,
3JPH ) 13.5 Hz, 3JHH ) 7.0 Hz, 3H, P(CHMeaMeb)), 0.77 (d of d, 3JPH
3
2
) 16.0 Hz, JHH ) 6.5 Hz, 3H, P(CHMeaMeb)), -11.58 (d, JPH
)
2
26.5 Hz, 1H, Ru-Ha), -12.58 (d, JPH ) 27.1 Hz, 1H, Ru-Hb); 13C-
{1H} NMR (CD2Cl2): δ 145.8 (m, C3a or C7a), 140.9 (m, C7a or
C3a), 138.7 (m, Si-aryl-C), 135.6 (2 Si-aryl-CHs), 129.6 (Si-aryl-CH),
127.5 (2 Si-aryl-CHs), 126.8 (C5 or C6), 125.7 (C4 and C7), 125.2
(C6 or C5), 96.8 (C5Me5), 75.7 (m, C2), 45.1 (d, 1JPC ) 19.6 Hz, C3),
44.4 (C1), 42.4 (NMe2), 27.2 (d, 1JPC ) 20.1 Hz, P(CHMecMed)), 26.4
1
(d, JPC ) 22.4 Hz, P(CHMeaMeb)), 22.8 (P(CHMeaMeb)), 21.6
2
(P(CHMecMed)), 19.1 (P(CHMeaMeb)), 18.5 (d, JPC ) 5.0 Hz,
Acknowledgment is made to the Natural Sciences and
Engineering Research Council (NSERC) of Canada (including
a Discovery Grant for M.S. and a Postgraduate Scholarship for
M.A.R.), the Canada Foundation for Innovation, the Nova Scotia
Research and Innovation Trust Fund, and Dalhousie University
for their generous support of this work. We also thank Drs.
Michael Lumsden and Katherine Robertson (Atlantic Region
Magnetic Resonance Center, Dalhousie) for their assistance in
the acquisition of NMR data. Dedicated to Professor T. Don
P(CHMecMed)), 11.5 (C5Me5); 31P{1H} NMR (CD2Cl2): δ 87.6; 29Si-
{1H} NMR (CD2Cl2): δ 91.4 (1H-29Si HMBC), 2JSiH not detected by
J-HMBC. Slow diffusion of pentane into a CH2Cl2 solution of 10 at
ambient temperature provided a single crystal suitable for X-ray
analysis.
Crystallographic Solution and Refinement Details for [4]+X-,
[5]+X-, [6]+X-, and 10 (X ) SO3CF3). In each case, crystallographic
data were obtained at 173((2) K on a Nonius KappaCCD 4-Circle
Kappa FR540C diffractometer using a graphite-monochromated Mo
KR (λ ) 0.71073 Å) radiation, employing a sample that was mounted
in inert oil and transferred to a cold gas stream on the diffractometer.
Cell parameters were initially retrieved using the COLLECT software
(Nonius) and refined with the HKL DENZO and SCALEPACK
software.24 Data reduction and absorption correction (multiscan) were
also performed with the HKL DENZO and SCALEPACK software.
The structure was solved by using the direct methods package in SIR-
9725 and refined with SHELXL-97-226 by use of full-matrix least-
(24) Otwinowski, Z.; Minor, W. HKL DENZO and SCALEPACK, v1.96;
In Macromolecular Crystallography, Part A; Carter, C. W., Jr., Sweet,
R. M., Eds.; Academic Press: San Diego 1997; Vol. 276, pp 307-
326.
(25) Altomare, A.; Cascarano, G.; Giacovazzo, C.; Guagliardi, A.; Moliterni,
A. G. G.; Burla, M. C.; Polidori, G.; Camalli, M.; Spagna, R. J. Appl.
Crystallogr. 1999, 32.
(26) Sheldrick, G. M. SHELXL97-2, Program for the Solution of Crystal
Structures; University of Go¨ttingen: Go¨ttingen, Germany 1997.
(27) Orpen, A. G. J. Chem. Soc., Dalton Trans. 1980, 2509.
squares procedures (on F2) with R1 based on Fo g 2σ(Fo ) and wR2
2
2
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A R T I C L E S
Rankin et al.
Tilley, in honor of his receiving the 2008 ACS-Stanley Kipping
Award for Silicon Chemistry.
Supporting Information Available: Single-crystal X-ray
diffraction data in CIF format for [4]+X-, [5]+X-, [6]+X-, 8,
and 10. This material is available free of charge via the Internet
at http://pubs.acs.org.
Note Added in Proof. A crystallographically characterized
RudSiHR complex has recently been reported: Ochiai, M.;
Hashimoto, H.; Tobita, H. Angew. Chem. Int. Ed. 2007, 46,
8192.
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