Syntheses and X-ray diffraction studies of half-sandwich hydridosilyl complexes of ruthenium

Article abstract of DOI:10.1021/om0495271

A series of a half-sandwich trihydrides of ruthenium was synthesized and investigated using x-ray diffraction. The reaction of ruthenium trihydrides with chlorosilanes occurred in complex manner and resulted in various products. With more acidic silanes, HSiCl₂Me and HSiCl₃, the formation of the Ru-Cl bond becomes reaction route. Results show that Ruthenium compound can support the occurrence of H-Si interaction in its silyl hydride derivatives.

Full text of DOI:10.1021/om0495271

Organometallics 2005, 24, 587-602
587
Syntheses and X-ray Diffraction Studies of
Half-Sandwich Hydridosilyl Complexes of Ruthenium
Alexander L. Osipov,† Sergei M. Gerdov,† Lyudmila G. Kuzmina,‡
Judith A. K. Howard,§ and Georgii I. Nikonov*,†
Chemistry Department, Moscow State University, Vorob’evy Gory, 119992 Moscow, Russia,
Institute of General and Inorganic Chemistry RAS, Leninskii Prosp. 31,
119991 Moscow, Russia, and Chemistry Department, University of Durham, South Road,
Durham DH1 3LE, U.K.
Received June 30, 2004
The reactions of a series of half-sandwich trihydrides of ruthenium, Cp*(R3P)Ru(H)3 (R3P
) Pri3P, Pri2MeP, PriMe2P, PhMe2P), with a family of chlorosilanes (ClSiHMe2, Cl2SiHMe,
Cl3SiH) have been studed with the aim of preparing the dihydridesilyl derivatives Cp*-
(R3P)Ru(H)2(SiR3). The reaction of Cp*(R3P)Ru(H)3 with ClSiHMe2 occurs at 90 °C and gives
two types of products, Cp*(R3P)Ru(H)2(SiClMe2) (1) and Cp*(R3P)Ru(H)2(SiCl2Me) (2). The
yield of complexes 2 increases with the decrease of the size of the phosphine ligand. X-ray
structures of Cp*(Pri3P)Ru(H)2(SiClMe2) (1a) and Cp*(Pri2MeP)Ru(H)2(SiClMe2) (1b) are
consistent with the presence of interligand hypervalent interactions Ru-H‚‚‚Si-Cl. The
compounds Cp*(R3P)Ru(H)(Cl)(SiCl2Me) (3) were prepared by the reaction of Cp*(R3P)Ru-
(H)3 with Cl2SiHMe at 60 °C and characterized by NMR and IR spectroscopy. Complex Cp*-
(Pri3P)Ru(Cl)(SiCl2Me)(H) (3a) reacts with excess PMe3 to give the H-Si elimination product
Cp*(PMe3)2RuCl. The reactions of Cp*(R3P)Ru(H)3 (R3P ) Pri3P, Pri2MeP) with Cl2SiHMe
in the presence of NEt3 at 90 °C give the dihydridesilyls Cp*(R3P)Ru(H)2(SiCl2Me) (R3P )
Pri3P (2a), R3P ) Pri2MeP (2b)). X-ray structures of these products may be rationalized as
containing a double interligand hypervalent interaction Ru-H2‚‚‚Si-Cl2. NMR reaction
between Cp*(MePri2P)Ru(H)3 and excess Cl3SiMe at 100 °C resulted in a clean formation of
Cp*(MePri2P)Ru(H)(Cl)(SiCl2Me). Complexes Cp*(R3P)Ru(Cl)(SiCl3)(H) (5) were prepared by
the reaction of Cp*(R3P)Ru(H)3 with Cl3SiH at room temperature and characterized by NMR
and IR spectroscopy. The reactions of Cp*(R3P)Ru(H)3 (R3P ) Pri3P, Pri2MeP) with Cl3SiH
in the presence of NEt3 at 60 °C give the dihydridesilyls Cp*(R3P)Ru(H)2(SiCl2H) (R3P )
Pri3P (6a), R3P ) Pri2MeP (6b)) along with a mixture of some other compounds, whereas
the analogous reactions in the presence of NPri2Et afford the dihydridesilyls Cp*(R3P)Ru-
(H)2(SiClH2) (R3P ) Pri3P (7a), R3P ) Pri2MeP (7b)). Complex Cp*(Pri3P)RuH2(SiH3) (8a),
prepared by the reduction of Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a) by LiAlH4, reacts with [NHMe2-
Ph]Cl to give a mixture of Cp*(Pri3P)Ru(H)3 and Cp*(Pri3P)Ru(H)2(SiClH2) (7a). The crystal
structures of 1a,1b, 2a, 2c, 5b, 5c, 5d, and 8a have been determined by X-ray structure
analysis.
Introduction
silicon atom,3-5 Si-E (E ) C, Si) bond activation and
formation,6,7 and dehydrogenative coupling of silanes to
carbosilanes.8 Apart from this, an impressive abundance
of different structural types of silicon-substituted com-
Orgonosilicon derivatives of ruthenium display a very
rich and diverse chemistry in transformations of silicon
compounds such as hydrosilylation,1 dehydrogenative
polymerization of silanes,2 redistribution reactions at
(3) (a) Curtis, M. D.; Epstein, P. S. Adv. Organomet. Chem. 1981,
19, 213. (b) Grumbine, S. K.; Tilley, T. D. J. Am. Chem. Soc. 1994,
116, 6951. (c) Kobayashi, T.; Hayashi, T.; Yamashita, H.; Tanaka, M.
Chem. Lett. 1988, 1411.
(4) Said, R. B.; Hussien, K.; Barthelat, J.-C.; Atheaux, I.; Sabo-
Etienne, S.; Donnadieu, B.; Chaudret, B. J. Chem. Soc., Dalton. Trans.
2003, 4139.
(5) Burgio, J.; Yardy, N. M.; Petersen, J. L.; Lemke, F. R. Organo-
metallics 2003, 22, 4928.
(6) Si-C activation/formation: (a) Huang, D.; Heyn, R. H.; Bollinh-
ger, J. C.; Caulton, K. G. Organometallics 1997, 16, 292. (b) Rickard,
C. E. F.; Roper, W. R.; Salter, D. M.; Wright, L. J. Organometallics
1992, 11, 3931. (c) Maddock, S. M.; Rickard, C. E. F.; Roper, W. R.;
Wright, L. J. Organometallics 1996, 15, 1793. (d) Ezbiansky, K.;
Djurovich, P. I.; LaForest, M.; Sinning, D. J.; Zayes, R.; Berry, D. H.
Organometallics 1998, 17, 1455. (e) Takao, T.; Amako, M.; Suzuki, H.
Organometallics 2003, 22, 3855. (f) Dioumaev, V. K.; Yoo, B. R.;
Procopio, L. J.; Berry, D. H. J. Am. Chem. Soc. 2003, 125, 8936.
* To whom correspondence should be addressed. Tel: (095)9391976.
Fax: (095)9328846. E-mail: nikonov@org.chem.msu.su.
† Moscow State University.
‡ Institute of General and Inorganic Chemistry RAS.
§ University of Durham.
(1) (a) Ojima, I. In The Chemistry of Organic Silicon Compounds;
Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1989; Chapter 25.
(b) Katayama, H.; Taniguchi, K.; Kobayashi, M.; Sagawa, T.; Minami,
T.; Ozawa, F. J. Organomet. Chem. 2002, 645, 192. (c) Christ, M. L.;
Sabo-Etienne, S.; Chaudret, B. Organometallics 1995, 14, 1082. (d)
Delpech, F.; Mansa, J.; Leuser, H.; Sabo-Etienne, S.; Chaudret, B.
Organometallics 2000, 19, 5750. (e) Glaser, P. B.; Tilley, T. D. J. Am.
Chem. Soc. 2003, 125, 13640.
(2) (a) Rosenberg, L.; Davis, C. W.; Yao, J. J. Am. Chem. Soc. 2001,
123, 5120. (b) Rosenberg, L.; Kobus, D. N. J. Organomet. Chem. 2003,
685, 107.
10.1021/om0495271 CCC: $30.25 © 2005 American Chemical Society
Publication on Web 01/19/2005

588 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
Chart 1. Types of Organosilicon Complexes of
Ruthenium
Chart 2. Examples of Ruthenium Complexes with
Nonclassical Si-H Interactions
plexes of ruthenium is found. These include silyl,9
silylene,10-12 and silene13 derivatives (Chart 1) and a
range of nonclassical complexes4,14-26 having nonclas-
sical (secondary) Si-H interactions (Chart 2). The most
relevant to the present paper is the class of hydridosilyl
complexes of the type LnRu(H)m(SiR3)k known for dif-
Chart 3. Examples of Classical Silyl Hydride
Complexes of Ruthenium
(7) Si-Si activation: (a) Sun, C.; Tu, A.; Slough, G. A. J. Organomet.
Chem. 1999, 582, 235. (b) Taw, F. L.; Bergman, R. G.; Brookhart, M.
Organometallics 2004, 23, 886. (c) Shimada, S.; Rao, M. L. N.; Hayashi,
T.; Tanaka, M. Angew. Chem. 2001, 113, 219; Angew. Chem., Int. Ed.
2001, 40, 213.
(8) (a) Procopio, L. J.; Berry, D. H. J. Am. Chem. Soc., 1991, 113,
4039. (b) Djurovich, P. I.; Dolich, A. R.; Berry, D. H. J. Chem. Soc.,
Chem. Commun. 1994, 1897.
(9) (a) In addition to a multitude of terminal ruthenium silyls cited
in this paper, the possibility of bridging silyl ligands has been invoked:
Lin, W.; Wilson, S. R.; Girolami, G. S. J. Am. Chem. Soc. 1993, 115,
3022. (b) Such a bridging silyl has been documented for a rhodium
complex: Osakada, K.; Koizumi, T.; Yamamoto, T. Angew. Chem., Int.
Ed. 1998, 37, 349.
(10) Bridging silylenes: (a) Suzuki, H.; Takao, T.; Tanaka, M.; Moro-
oka, Y. Chem. Commun. 1992, 476. (b) Takao, T.; Amako, M.; Suzuki,
H. Organometallics 2003, 22, 3855, and references therein. (c) Cam-
pion, B. K.; Heyn, R. H.; Tilley, T. D. Organometallics 1992, 11, 3918.
(11) Terminal silylenes: (a) Straus, D. A.; Zhang, C.; Quimbita, G.
E.; Grumbine, S. K.; Heyn, R. H.; Tilley, T. D.; Rheingold, A. L.; Geib,
S. J. J. Am. Chem. Soc. 1990, 112, 2673. (b) Straus, D. A.; Tilley, T.
D.; Rheingold, A. L.; Geib, S. J. J. Am. Chem. Soc. 1987, 109, 5872. (c)
Grumbine, S. K.; Tilley, T. D.; Arnold, F. P.; Rheingold, A. L. J. Am.
Chem. Soc. 1990, 112, 2673. (d) Grumbine, S. K.; Mitchell, G. P.;
Straus, D. A.; Tilley, T. D.; Rheingold, A. L.; Geib, S. J. Organometallics
1998, 17, 5607.
ferent ratios of k and m and different supporting ligands
Ln (Chart 3).11,27-33
Our interest in the chemistry of the organosilicon
complexes of ruthenium stems from our previous studies
on the hydridosilyl complexes of early transition met-
als.34 We have shown that basic transition metal hy-
drides having a functionalized silyl group in the cis
position to the hydride ligand can have nonclassical
interligand hypervalent interactions (IHI) between these
groups.34b-i This type of interligand bonding has been
studied in detail for the metallocene34d,f-i and isolobal
Cp-imido34b,c,e ligand environments (Chart 4). We were
(12) Ogino type silylenes: (a) Tobita, H.; Wada, H.; Ueno, K.; Ogino,
H. Organometallics 1994, 13, 2545. (b) Wada, H.; Tobita, H.; Ogino,
H. Organometallics 1997, 16, 2200. (c) Tobita, H.; Kurita, H.; Ogino,
H. Organometallics 1998, 17, 2844. (d) Tobita, H.; Kurita, H.; Ogino,
H. Organometallics 1998, 17, 2850. (e) Wada, H.; Tobita, H.; Ogino,
H. Chem. Lett. 1998, 993. (f) Choo, T. N.; Kwock, W.-H.; Rickard, C.
E. F.; Roper, W. R.; Wright, L. J. J. Organomet. Chem. 2002, 645, 235.
(13) (a) Dioumaev, V. K.; Poessl, K.; Carrol, P. J.; Berry, D. H. J.
Am. Chem. Soc. 1999, 121, 8391. (b) Campion, B. K.; Heyn, R. H.;
Tilley, T. D. J. Am. Chem. Soc. 1988, 115, 7558. (c) Campion, B. K.;
Heyn, R. H.; Tilley, T. D.; Rheingold, A. L. J. Am. Chem. Soc. 1993,
115, 5527.
(27) (a) Haszeldine, R. N.; Malkin, L. S.; Parish, R. V. J. Organomet.
Chem. 1979, 182, 323. (b) Kono, H.; Wakao N.; Ito, K.; Nagai, Y. J.
Organomet. Chem. 1977, 132, 53. (c) An earlier work with a different
interpretation: Svoboda, P.; Rˇ erˇicha, R.; Hetfleisˇ, J. Collect.
Czech.Chem. Commun. 1974, 39, 1324.
(28) Campion, B. K.; Heyn, R. H.; Tilley, T. D. Chem. Commun.
1988, 278.
(14) Ng, S. N.; Lau, C. P., Fan, M.-F.; Lin, Z. Organometallics 1998,
18, 2484.
(29) Campion, B. K.; Heyn, R. H.; Tilley, T. D. Chem. Commun.
1992, 1201.
(15) Atheaux, I.; Donnadieu, B.; Rodriguez, V.; Sabo-Etienne, S.;
Chaudret, B.; Hussein, K.; Barthelat, J.-C. J. Am. Chem. Soc. 2000,
122, 5664.
(30) Johnson, T. J.; Coan, P. S.; Caulton, K. G. Inorg. Chem. 1993,
32, 4594.
(31) Rodriguez, V.; Donnadieu, B.; Sabo-Etienne, S.; Chaudret, B.
Organometallics 1998, 17, 3809.
(16) Lachaize, S.; Sabo-Etienne, S.; Donnadieu, B.; Chaudret, B.
Chem. Commun. 2003, 214.
(32) Lemke, F. R.; Chaitheerapapkul, C. Polyhedron 1996, 15, 2559.
(33) (a) Dioumaev, V. K.; Yoo, B. R.; Procopio, L. J.; Carrol, P. J.;
Berry, D. H. J. Am. Chem. Soc. 2003, 125, 8936. (b) Djurovich, P. I.;
Carrol, P. J.; Berry, D. H. Organometallics 1994, 13, 2551. (c) Einstein,
F. W. B.; Jones, T. Inorg. Chem. 1982, 21, 987.
(17) Hussein, K.; Marsden, C. J.; Barthelat, J.-C.; Rodriguez, V.;
Conejero, S.; Sabo-Etienne, S.; Donnadieu, B.; Chaudret, B. Chem.
Commun. 1999, 1315.
(18) Delpech, F.; Sabo-Etienne, S.; Chaudret, B.; Daran, J.-C. J. Am.
Chem. Soc. 1997, 119, 3167.
(34) (a) Ignatov, S. K.; Rees, N. H.; Dubberley, S. R.; Razuvaev, A.
G Mountford, P.; Nikonov, G. I. Chem. Commun. 2004, 952. (b)
Dubberley, S. R.; Ignatov, S. K.; Rees, N. H.; Razuvaev, A. G.;
Mountford, P.; Nikonov, G. I. J. Am. Chem. Soc. 2003, 125, 644. (c)
Nikonov, G. I.; Mountford, P.; Dubberley, S. R. Inorg. Chem. 2003, 42,
58. (d) Nikonov, G. I.; Kuzmina, L. G.; Howard, J. A. K. J. Chem. Soc.,
Dalton Trans. 2002, 3037. (e) Nikonov, G. I.; Mountford, P.; Ignatov,
S. K.; Green, J. C.; Cooke, P. A.; Leech, M. A.; Kuzmina, L. G.;
Razuvaev, A. G.; Rees, N. H.; Blake, A. J.; Howard, J. A. K.;
Lemenovskii, D. A. Dalton Trans. 2001, 2903. (f) Bakhmutov, V. I.;
Howard, J. A. K.; Keen, D. A.; Kuzmina, L. G.; Leech, M. A.; Nikonov,
G. I.; Vorontsov, E. V.; Wilson, C. C. J. Chem. Soc., Dalton Trans. 2000,
1631. (g) Nikonov, G. I.; Kuzmina, L. G.; Vyboishchikov, S. F.;
Lemenovskii, D. A.; Howard, J. A. K. Chem.-Eur. J. 1999, 5, 2497. (h)
Dorogov, K. Yu.; Dumont, E.; Ho, N.-N.; Churakov, A. V.; Kuzmina,
L. G.; Poblet, J.-M.; Schultz, A. J.; Howard, J. A. K.; Bau, R.; Lledos,
A.; Nikonov, G. I. Organometallics 2004, 23, 2845. (i) Ignatov, S. K.;
Rees, N. H.; Tyrrell, B. R.; Dubberley, S. R.; Razuvaev, A. G.;
Mountford, P.; Nikonov, G. I. Chem.-Eur. J. 2004, 10, 4991.
(19) Delpech, F.; Sabo-Etienne, S.; Daran, J.-C.; Chaudret, B.;
Hussein, K.; Marsden, C. J.; Barthelat, J.-C. J. Am. Chem. Soc. 1999,
121, 6668.
(20) Atheaux, I.; Delpech, F.; Donnadieu, B.; Sabo-Etienne, S.;
Chaudret, B.; Hussien, K.; Barthelat, J.-C.; Braun, T.; Duckett, S. B.;
Perutz, R. N. Organometallics 2002, 21, 5347.
(21) Delpech, F.; Sabo-Etienne, S.; Donnadieu, B.; Chaudret, B.
Organometallics 1998, 17, 4926.
(22) Yin, J.; Klosin, J.; Abboud, K. A.; Jones, W. M. J. Am. Chem.
Soc. 1995, 117, 3298.
(23) Freeman, S. T. N.; Lemke, F. R.; Brammer, L. Organometallics
2002, 21, 2030.
(24) Dioumaev, V. K.; Carrol, P. J.; Berry, D. H. Angew. Chem. 2003,
115, 4077.
(25) Yardy, N. M.; Lemke, F. R.; Brammer, L. Organometallics 2001,
20, 5670.
(26) Hu¨bler, K.; Hu¨bler, U.; Roper, W. R.; Schwerdtfeger, P.; Write,
L. J. Chem. Eur. J. 1997, 3, 1608.

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 589
(R ) Me, R′ ) Et; R ) Ph, R′ ) Cl)32), but the crucial
structural information is very scarce.31 To get further
insight into this problem, we studied the interactions
of various trihydrides Cp*(R3P)Ru(H)3 with a family of
chlorosilanes (ClSiHMe2, Cl2SiHMe, Cl3SiH). Our initial
goal was to prepare a series of complexes Cp*(R3P)-
Ru(H)2(SiR′3-nCln) (n ) 1-3) and to establish the
occurrence and strength of any H-Si interaction as a
function of the electronic and steric properties of the
substituent R at the phosphorus atom and the number
of chlorine groups on the silicon atom. The results of
this research are reported here.
Chart 4. Examples of Early Transition Metal
Complexes with IHI
Chart 5. Isolobal Relationship between Group 5
Fragment Cp2M and Group 8 Fragment Cp(R3P)M
Results and Discussion
1. Reactions of Ruthenium Trihydrides with
ClSiHMe2. The trihydrides Cp*(RPri2P)Ru(H)3 (R )
Me, Pri), containing bulky phosphines Pri3P and MePri2P,
react with ClSiHMe2 upon heating to 90 °C for 6-10 h
to give the target monosilyl dihydride complexes Cp*-
(RPri2P)Ru(H)2(SiClMe2) (1a, R ) Pri; 1b, R ) Me; eq
1). No reaction occurs at room temperature and only a
intrigued by the surprising analogy between the group
5 metallocene moiety Cp2M and group 8 Cp/phosphine
fragment Cp(R3P)M. Namely, both fragments have the
same number of valence orbitals of identical topological
properties and comparable energies35 and can accom-
modate up to three substituents. Although, these orbit-
als lie in one plane in Cp2M,35a which is not the case
for Cp(R3P)M,35b this discrepancy is not vital for the
occurrence of interligand bonding between H and Si
atoms. Therefore, the question of whether complexes of
the general formula Cp′′(R3P)Ru(X)(H)(SiR2Y) (Y )
halogen; X ) any one-electron ligand; Cp′′ ) Cp or Cp*)
can have any interaction between the hydride and silyl
groups is appropriate. Taking into account that the
ruthenium atom in these complexes has the formal
oxidation state (IV), which is good for the formation of
silane σ-complexes in many structures,14-21 this ques-
tion can be reformulated as whether the donor ability
of the Cp/(R3P) ligand set is sufficient to make the
basicity of the hydride ligand high enough to “switch
on” IHI of the type Ru-H‚‚‚Si-Y. The recently deter-
mined basicity of the hydrides in Cp*(Cy3P)RuH3 (basic-
ity factor Ej ) 0.94)36 suggests that this is possible. Some
structural features of the compound Cp*(Pri3P)Ru(H)2-
(SiHClMes)29 (Mes ) 2,4,6-trimethylphenyl), such as a
long Si-Cl bond and short Ru-Si bond, are also
indicative of the presence of IHI,37 whereas the com-
pound Cp*(Ph3P)Ru(H)2(SiMe2Cl), having a less basic
phosphine (and hence less basic hydride), is classical.37
A few other compounds of the type Cp′′(R3P)Ru(X)(H)-
(SiR2Y) are known: (Cp*(Pri3P)Ru(H)2(SiMePh2),29 Cp*-
(Pri3P)Ru(H)(Cl)(SiR3) (SiR3 ) SiCl2Me, SiPhH2, SiPhH-
SiPhH2),28,29 Cp*(Me3P)Ru(H)(SiR3)2 (SiR3 ) Si(OEt)3,
SiClPh2, SiMe2OEt),11a Cp*(PhPri2P)Ru(H)2(SiR3) (SiR3
) Si(OMe)3, SiMe3, SiPh3, SiHPh2, SiPh2OCH2CF3),30
Cp*((pyrrolyl)3P)Ru(H)2(SiMe2Ph),31 Cp(R3P)Ru(H)(SiR′3)2
sluggish one at 60 °C. The optimum temperature for the
thermolysis is 90 °C, since raising the temperature over
100 °C results in the formation of impurities. Complexes
1a,b have been characterized by IR and NMR (1H, 13C,
31P, 28Si) spectroscopy, and their structures have been
1
determined by X-ray diffraction studies. The H NMR
spectra of 1a,b show signals of the equivalent methyl
groups on silicon atoms (0.98 ppm for 1a and 1.00 ppm
for 1b) and resonances due to the equivalent hydrides
(-12.23 (d, J(P-H) ) 28.0 Hz) for 1a and -12.21 (d,
1
J(P-H) ) 28.6 Hz for 1b)). In addition, the H NMR
spectrum of 1b shows two sets of signals due to the
isopropyl groups of the phosphine, consistent with the
Cs symmetry of the complex and the central position of
the silyl ligand trans to phosphine. No significant (i.e.,
>20 Hz)39c,d silicon-hydride coupling can be seen from
the silicon satellites of the hydride signals (J(Si-H) )
11.7 Hz for 1a and 12.9 Hz for 1b).
1
Analysis of the H NMR spectrum of the NMR tube
reaction between Cp*(MePri2P)Ru(H)3 and ClSiHMe2
showed that the silane redistribution product Cp*-
(MePri2P)Ru(H)2(SiCl2Me) (2b) is also produced in about
(35) (a) The properties of the Cp2M fragment, see: Lauer, J. W.;
Hoffmann, R. J. Am. Chem. Soc. 1976, 98, 1729. (b) The Cp(R3P)M
fragment was discussed for the group 9 metals: Hofmann, P.; Pad-
manabhan, M. Organometallics 1983, 2, 1273. (c) Albright, T. A.
Tetrahedron 1982, 38, 1339. (d) Lin, Z.; Hall, M. B. Organometallics
1993, 12, 19.
(38) For the related redistribution reactions of silanes on other
metals see: (a) Ref 3a. (b) Rahimian, K.; Harrod, J. F. Inorg. Chim.
Acta 1998, 270, 330. (c) Woo, H.-G.; Heyn, R. H.; Tilley, T. D. J. Am.
Chem. Soc. 1992, 114, 5698. (d) Pestana, D. C.; Koloski, T. S.; Berry,
D. H. Organometallics 1994, 13, 4173.
(39) Kubas, G. J. Metal Dihydrogen and σ-Bond Complexes; Kluwer
Academic/Plenum: New York, 2001. (b) Crabtree, R. H. Angew. Chem.,
Int. Ed. Engl. 1993, 32, 789. (c) Schubert, U. Adv. Organomet. Chem.
1990, 30, 151. (d) Corey, J. Y.; Braddock-Wilking, J. Chem. Rev. 1999,
99, 175.
(36) (a) Shubina, E. S. Personal communication. (b) A similar
Ru(II) complex, Cp(Cy3P)(CO)Ru(H), with a π-acceptor ligand has the
basicity factor Ej ) 1.0, whereas complexes (dppm)2RuH2 and P(CH2-
CH2PPh2)3RuH2, having only the donating ligands at Ru, are more
basic (Ej ) 1.40 and 1.33, respectively): Epstein, L. M.; Shubina, E. S.
Coord. Chem. Rev. 2002, 231, 165.
(37) Duckett, S. B.; Kuzmina, L. G.; Nikonov, G. I. Inorg. Chem.
Commun. 2000, 3/3, 126.

590 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
5% yield. In contrast, no traces of 2a can be seen in the
NMR tube reaction between Cp*(Pri3P)Ru(H)3 and ClSi-
HMe2. The reaction of the less bulky complex Cp*(Me2-
PriP)Ru(H)3 with ClSiHMe2 is different in that in
addition to the expected product Cp*(Me2PriP)Ru(H)2-
(SiClMe2) (1c) an equivalent amount of the dichlorosilyl
derivative Cp*(Me2PriP)Ru(H)2(SiCl2Me) (2c) is formed.
Like complexes 1a,b, both 1c and 2c do not show any
significant silicon-hydride coupling constant (both J(Si-
1
H) < 13 Hz). The hydride signal of 2c in the H NMR
spectrum is shifted to lower field (-11.54 ppm, J(P-H)
) 29.2 Hz, J(Si-H) ) 11.0 Hz), compared to the signal
of 1c (-12.13 ppm, J(P-H) ) 29.4 Hz, J(Si-H) ) 12.9
Hz). We failed to separate 1c from 2c due to their
comparable solubility properties. However, an X-ray
quality crystal of 2c was grown by slowly cooling an
ether solution of the mixture to -30 °C, and the
molecular structure was determined. Analogously, the
reaction of Cp*(Me2PhP)Ru(H)3 with HSiClMe2 in tolu-
ene in the presence of 15-fold excess silane (5 h, 90 °C)
gives a 1:1 mixture of 1d and Cp*(Me2PhP)Ru(H)2(SiCl2-
Me) (2d) along with another yet unidentified phosphine
complex. All attempts to separate these two products
failed.
Figure 1. Molecular structure of complex 1b. Thermal
ellipsoids are given at the 50% probability level. Hydrogen
atoms on carbons are omitted for clarity.
Table 1. Bond Lengths (Å) and Angles (deg) for 1a
and 1b
Complexes 2 apparently emerge as a result of a
redistribution process at the silicon center. Such a
redistribution reaction has many precedents in the
organosilicon chemistry of ruthenium.3-5,32,38 In par-
ticular, Lemke et al. have very recently reported that
the reaction of RuCl2(PPh3)3 with ClSiHMe2 in benzene
produces a mixture of (η6-C6H6)Ru(PPh3)2(SiClMe2)2,
(η6-C6H6)Ru(PPh3)2(SiClMe2)(SiCl2Me), and (η6-C6H6)-
Ru(PPh3)2(SiCl2Me)2; the yield of the more chlorinated
silyl derivatives increases when higher temperatures
(65 °C) are applied.5
The central question of the current study is whether
there is any nonclassical Si-H interaction in the (chlo-
rosilyl)hydrido complexes of ruthenium, like 1 and 2.
This question can be answered, in principle, by means
of spectroscopic and structural methods. For the silane
σ-complexes, such as those shown in Chart 2, the most
common criterion of the presence of a Si-H bonding has
been the observation of a Si-H coupling constant J(Si-
H) higher than 20 Hz.39 It is, however, becoming
increasingly clear that this criterion is not generally
applicable to all types of nonclassical complexes.34i,40 For
the compounds with IHI, the theory does not require
high values of J(Si-H) for the presence of Si-H
bonding.34e In fact, it has been shown for some systems
that the Si-H interaction weakens as the absolute value
of J(Si-H) increases.34b,i Therefore, the observation of
relatively low values (J(Si-H) < 13 Hz) of J(Si-H) for
1 and 2c does not unequivocally rule out the presence
of Si-H interactions, and structural criteria should be
considered. IHI consists in the electron density transfer
from the high lying M-H bond orbital to the (Si-X)*
antibonding orbital, which results in the elongation of
the M-H and Si-X bonds and decrease of the M-Si
and Si-H distances.34b-i A long Si-Cl bond and short
Ru-Si bond are observed in Cp*(Pri3P)Ru(H)2(Si-
HClMes),29 whereas the compound with the less basic
phosphine, Cp*(Ph3P)Ru(H)2(SiMe2Cl), is classical.37
1a
1b
Ru(1)-Si(1)
2.332(1)
2.3095(9)
1.51(4)
1.53(4)
2.03(4)
2.04(4)
2.026(7)
2.118(2)
1.898(3)
1.94(1)
1.89(5)
102.69(3)
109(2)
2.3352(8)
2.3079(7)
1.53(6)
Ru(1)-P(1)
Ru(1)-H(1)
Ru(1)-H(2)
1.63(6)
Si(1)-H(1)
2.17(6)
Si(1)-H(2)
2.03(6)
Si(1)-Cl(1)a
2.170(1)
Si(1)-Cl(1A)a
Si(1)-C(11)
1.942(3)
1.913(3)
Si(1)-C(12)a
Si(1)-C(12A)a
P(1)-Ru(1)-Si(1)
H(2)-Ru(1)-H(1)
Si(1)-Ru(1)-H(1)
Si(1)-Ru(1)-H(2)
P(1)-Ru(1)-H(1)
P(1)-Ru(1)-H(2)
C(11)-Si(1)-Cl(1)
C(11)-Si(1)-Cl(1A)
C(12)-Si(1)-C(11)
C(12A)-Si(1)-C(11)
C(12)-Si(1)-Cl(1)
C(12A)-Si(1)-Cl(1A)
C(11)-Si(1)-Ru(1)
C(12)-Si(1)-Ru(1)
C(12A)-Si(1)-Ru(1)
Cl(1)-Si(1)-Ru(1)
Cl(1A)-Si(1)-Ru(1)
Cl(1)-Si(1)-H(1)
Cl(1)-Si(1)-H(2)
Cl(1A)-Si(1)-H(1)
Cl(1A)-Si(1)-H(2)
104.66(3)
110(3)
64(2)
59(2)
59(1)
58(2)
83(2)
79(2)
78(2)
79(2)
101.2(2)
97.8(1)
100.8(4)
99(2)
100.9(1)
102.5(2)
99.3(1)
101.9(4)
104(2)
124.0(1)
115.7(4)
112(2)
121.94(9)
116.6(1)
115.1(1)
113.19(5)
153(2)
112.51(5)
151(2)
83(2)
89(2)
84(2)
152(2)
a In 1a the pairs C(12)/C(12A) and Cl(1)/Cl(1A) denote the
disordered methyl and chloride groups on Si(1), respectively.
The molecular structure of complex 1b is shown in
Figure 1, and the corresponding figure for 1a is depos-
ited in the Supporting Information. Some selected
molecular parameters for 1a and 1b are gathered in
Table 1. The analysis of the structure of 1a is compli-
cated by the disorder of the SiMe2Cl group, which affects
the value of the crucial Si-Cl bond length. This prob-
lem, however, does not intervene in the Ru-Si bond
(2.332(1) Å). Fortunately, the disorder problem does not
exist for 1b, which shows a very similar Ru-Si bond
(40) (a) Lichtenberger, D. L. Organometallics 2003, 32, 1599. (b)
Nikonov, G. I. Organometallics 2003, 32, 1597.

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 591
length of 2.3352(8) Å. Both these values are longer than
the corresponding parameter in Cp*(Pri3P)Ru(H)2-
(SiHClMes) (2.302(3) Å) but are significantly shorter
than the Ru-Si bond lengths in the classical compounds
Cp*(Ph3P)Ru(H)2(SiClMe2) (2.364(2) Å) and Cp*(pyr3P)-
Ru(H)2(SiPhMe2) (2.4213(7) Å). The difference in the
Ru-Si bond lengths in Cp*(Pri3P)Ru(H)2(SiHClMes)
and 1a,b can be accounted for by a combination of steric
and electronic factors. Namely, the sum of electronega-
tivities of the H and Mes groups on silicon is somewhat
larger than that of two Me groups, thus, in accordance
with Bent’s rule,41 leading to a shorter Ru-Si distance.
Second and possibly most important, in Cp*(Pri3P)Ru-
(H)2(SiHClMes) the smallest group on the silicon atom,
the hydrogen atom, is oriented toward the bulky Cp*
ligand, whereas in 1a,b this position is occupied by the
Me group. Hence, a shorter Ru-Si bond can be accom-
modated by Cp*(Pri3P)Ru(H)2(SiHClMes). Overall, this
Ru-Si bond is exeptionally short, taking into account
that even the trichlorosilyl complexes Cp*(R3P)Ru(H)-
(Cl)(SiCl3), discussed below, feature significantly longer
bonds (range 2.3107-2.3153(8) Å) in spite of the pres-
ence of three electron-withdrawing Cl groups on the
silicon atom.
The Si-Cl bond of 2.170(1) Å in 1b is identical with
that in Cp*(Pri3P)Ru(H)2(SiHClMes) (2.170(4) Å), sug-
gesting that the electronic situation around the silicon
center in both compounds is in fact very similar. This
value is significantly longer than in the classical silyl
complexes bearing the SiR2Cl group (range 2.094-2.149
Å)42 but comparable to the elongated Si-Cl bonds in
the compounds with IHI (range 2.163-2.222(2) Å).34 The
Si-H distance in 1a,b is a less reliable indicator of the
Si-H interaction due to the well-known inaccuracy in
finding the hydride in the vicinity of heavy elements.
In the complexes Cp*(Pri3P)Ru(H)2(SiHClMes) and 1a,b
one of the hydrides appears to form a short contact to
the silicon atom (2.03, 2.04, 2.03 Å, respectively),
whereas in Cp*(Ph3P)Ru(H)2(SiClMe2) both the Si-H
distances determined by X-ray study are rather long
(2.189 and 2.271 Å). However, in the classical complex
Cp*(pyr3P)Ru(H)2(SiPhMe2) short contacts of 1.95(3)
and 2.03(3) Å are also seen. To summarize, the struc-
tural trends observed in Cp*(Pri3P)Ru(H)2(SiHClMes)
and 1a,b are consistent with the presence of interligand
hypervalent interaction Ru-H‚‚‚Si-Cl.
(PPri3, PCy3).28,29 The formation of 3 implies the chlo-
rination of a Ru-H bond under the action of chlorosi-
lanes, which has literature precedents.25,27 Complexes
3 have been characterized by IR and NMR spectroscopy
and by comparison with the previously studied ana-
logues.
Complexes 4 are the formal silyl-for-hydride exchange
products of the reaction of Cp*(R3P)Ru(H)3 with HSiCl2-
Me, and the analogous H/Si exchange has been observed
in the related reactions of the compound Cp(Me3P)2Ru-
(H) with chlorosilanes Cl4-kSiRk (k ) 0, 1, 2)43 and
in several other systems.44,45 Lemke et al. reported
that the yield of the exchange products Cp(Me3P)2-
Ru(SiRkCl3-k) increases in the presence of amine, since
without any added amine an equivalent of Cp(Me3P)2-
Ru(H) is consumed by the HCl released, forming the
compound [Cp(Me3P)2Ru(H)2]Cl. Given these literature
data, we have also studied the reactions of the trihy-
drides Cp*(R3P)Ru(H)3 (R3 ) Pri3, MePri2) with HSiCl2-
Me in the presence of an amine. Addition of HSiCl2Me
to a mixture of Cp*(R3P)Ru(H)3 and NEt3 at room
temperature results in no reaction, consistent with the
lower basicity of the hydride ligands in the Ru(IV)
compounds Cp*(R3P)Ru(H)3 compared to the Ru(II)
complex Cp(Me3P)2Ru(H).36b Unexpected to us, heating
the mixture to 90 °C affords the compound Cp*-
(R3P)Ru(H)2(SiCl2Me) (2a,b, eq 3) as the main product
contaminated with small amounts of 3 and 4. An
2. Reactions of Ruthenium Trihydrides with
HSiCl2Me. The result of the reactions of the trihydrides
Cp*(R3P)Ru(H)3 (R3 ) Pri3, MePri2, Me2Pri) with silane
HSiCl2Me crucially depends on the conditions employed.
The reactions are very sluggish (3 weeks for R3 ) Pri3)
at room temperature and result in the formation of the
hydridosilyl complexes Cp*(R3P)Ru(Cl)(SiCl2Me)(H) (3,
eq 2) and Cp*(R3P)Ru(H)2(SiClHMe) (4). At 60 °C the
reactions are complete and give complexes 3 in 40-50%
isolated yields after 1.5 h. Some other examples of this
structural type have been previously prepared by oxida-
tive addition of hydrosilanes to the unsaturated com-
plexes Cp*(R3P)Ru(Cl) containing bulky phosphines
analogous reaction of Cp*(PhMe2P)Ru(H)3 gave a mix-
ture of four hydride-containing compounds, comprised
in addition to 2d, 3d, and 4d of Cp*(PhMe2P)Ru(H)2-
(SiClMe2) (1d) and a set of other yet unidentified
complexes. Apparently, complex 1d arises from a redis-
tribution reaction at the silicon center. No reaction
occurs at 50 °C between Cp*(PhMe2P)Ru(H)3 and the
silane Me2SiCl2 in the presence of amine NEtPri2.
Addition of 3 equiv of PMe3 to a toluene-d8 solution
of Cp*(Pri3P)Ru(Cl)(SiCl2Me)(H) (3a) results in an
(41) Bent, H. A. Chem. Rev. 1961, 61, 275.
(43) Lemke, F. R.; Galat, K. J.; Youngs, W. J. Organometallics 1999,
18, 1419.
(44) Dorogov, K. Y.; Churakov, A. V.; Kuzmina, L. G.; Howard, J.
A. K.; Nikonov, G. I. Eur. J. Inorg. Chem. 2004, 771.
(45) Jutzi, P.; Petri, S. H. A. In Organosilicon Chemistry III: From
Molecules to Materials; Auner, N., Weis, J., Eds.; Wiley-VCH: Wein-
heim, 1998; p 275.
(42) (a) Lee, K. E.; Arif, A. M.; Gladysz, J. A. Chem. Ber. 1991, 124,
309. (b) Jagirdar, B. R.; Palmer, R.; Klabunde, K. J.; Radonovich, L.
Inorg. Chem. 1995, 34, 278. (c) Hays, M. K.; Eisenberg, R. Inorg. Chem.
1991, 30, 2623. (d) Koloski, T. S.; Pestana, D. C.; Carroll, P. J.; Berry,
D. H. Organometallics 1994, 13, 489. (e) Sakaba, H.; Hirata, T.; Kabuto,
C.; Horino, H. Chem. Lett. 2001, 1078.

592 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
Table 2. Bond Lengths (Å) and Angles (deg) for 2a
and 2c
2a
2c
Ru(1)-Si(1)
2.2950(5)
2.3237(5)
1.56(3)
1.64(3)
2.11
2.3099(9)
2.2888(9)
1.49(5)
1.68(8)
2.07
Ru(1)-P(1)
Ru(1)-H(1)
Ru(1)-H(2)
Si(1)-H(1)
Si(1)-H(2)
2.15
1.99
Si(1)-Cl(1)
2.1271(7)
2.1170(7)
1.944(2)
102.05(2)
115(2)
2.109(2)
2.108(2)
1.902(3)
104.08(3)
102(3)
Si(1)-Cl(2)
Si(1)-Ca
P(1)-Ru(1)-Si(1)
H(2)-Ru(1)-H(1)
Si(1)-Ru(1)-H(1)
Si(1)-Ru(1)-H(2)
P(1)-Ru(1)-H(1)
P(1)-Ru(1)-H(2)
Ca-Si(1)-Cl(1)
Ca-Si(1)-Cl(2)
Cl(1)-Si(1)-Cl(2)
C-Si(1)-Ru(1)
Cl(1)-Si(1)-Ru(1)
Cl(2)-Si(1)-Ru(1)
Cl(1)-Si(1)-H(1)
Cl(2)-Si(1)-H(2)
63(1)
62(2)
64(1)
57(2)
80(1)
82(2)
77(1)
71(2)
98.34(5)
99.43(5)
100.31(3)
125.98(5)
113.77(3)
114.93(3)
154(2)
100.6(1)
100.1(2)
99.07(6)
123.2(1)
115.42(5)
114.74(5)
151(3)
Figure 2. Molecular structure of complex 2a. Thermal
ellipsoids are given at the 50% probability level. Hydrogen
atoms on carbons are omitted for clarity.
instantaneous color change from light green to bright
orange-yellow of Cp*(PMe3)2RuCl and the release of free
phosphine Pri3P and an equivalent of the silane HSiCl2-
Me characterized by its Si-H signal at 5.22 ppm and
154(2)
160(3)
a C stands for C(11) in 2a and C(16) in 2c.
1
p-character of silicon is here distributed over two Si-
Cl bonds. The known complexes of the type LnM-SiRCl2
can be classified into two categories: those in which the
Si-Cl bond lengths span the range 2.007-2.094 Å,47
and the complexes with elongated Si-Cl bonds (up to
2.192 Å)5,25,34b,i,48,49 having either nonclassical interac-
tion between the silyl and hydride ligands25,34b,i or a
negative hyperconjugation between a metal centered
lone-pair and a (Si-Cl)* antibonding orbital.49 In the
compounds Cp(ArN)Ta(PMe3)(H)(SiMeCl2)34b and Cp2-
Ti(PMe3)(H)(SiMeCl2)34i with IHI the longer Si-Cl bond
(2.117(2) and 2.192(1) Å, respectively) lies trans to the
hydride and participates in IHI, whereas the shorter
bond (2.064(3) and 2.134(1) Å, respectively) does not.
In 2a each of the Si-Cl bonds lies approximately trans
to one of the hydrides (the bond angles Cl-Si-H are
both 154(2)°). This orientation creates the possibility of
two weak IHIs of the type Ru-H2‚‚‚Si-Cl2, as shown
below (structure A). It is instructive to compare struc-
ture A with the related complexes Cp(Me3P)2Ru(SiCl2R)
(B) studied by Lemke et al.44,49 In B there is a double
negative hyperconjugation of the ruthenium-centered
orbitals with two Si-Cl bonds. There is a clear analogy
between this hyperconjugation and the conjugation of
the lower lying Ru-H bond orbitals with two (Si-Cl)*
antibonding orbitals in A. Because the d orbitals of Ru
lie somewhat higher than the Ru-H bond orbitals and
the Ru center in Cp(Me3P)2Ru(SiCl2R) has a lower
formal oxidation state (II), the effect of the interaction
is more pronounced in B.
Si-Me signal at 0.23 ppm in the H NMR spectrum.
This suggests that H-Si elimination from 3 is quite
facile. In contrast, the compound Cp*(Pri3P)Ru(H)2-
(SiHClMes)29 has been previously reported to arise from
the thermal rearrangement of Cp*(Pri3P)Ru(Cl)(SiH2-
Mes)(H), which was rationalized in terms of Si-Cl bond
elimination and Si-H bond oxidative addition reactions.
An analogous Si-Cl elimination was proposed for Cp*-
(Pri3P)Ru(Cl)(SiPh2Me)(H),13c whereas the less sterically
hindered Cp*(Pri3P)Ru(Cl)(SiH2Ph)(H) is stable even
when heated at 90 °C for several hours.29 Therefore, the
silane H-Si versus Cl-Si elimination from Cp*(R3P)-
Ru(Cl)(SiR′3)(H) is driven by both the sterics and
electonegativity of the substituents at the silicon center.
To check the possibility of a direct oxidative addition
of the Si-Cl bond to ruthenium,46 we carried out an
NMR study of the reaction between Cp*(MePri2P)Ru-
(H)3 and excess Cl3SiMe. No reaction occurs at room
temperature, but heating to 100 °C for 2 h results in
clean formation of Cp*(MePri2P)Ru(Cl)(SiCl2Me)(H).
The same product is formed when this reaction is
carried out in the presence of NEt3, but no traces of the
possible exchange product Cp*(MePri2P)Ru(H)2(SiCl2-
Me) were observed.
The molecular structure of complex Cp*(Pri3P)Ru(H)2-
(SiCl2Me) (2a) is shown in Figure 2, and selected bond
distances and angles are given in Table 2. The Ru-Si
bond of 2.2950(5) Å in 2a is shorter than in the
monochlorosilyl complexes discussed above due to Bent’s
rule effect. Bent’s rule states that bonds to the electro-
positive substituents receive more s-character of the
central atom, making these bonds shorter, whereas the
p-character goes mainly to the bonds to more electro-
negative substituents, resulting in their elongation.41
Thus, the presence of two electron-withdrawing chlorine
groups on the silicon atom accounts for the shorter
Ru-Si bond in 2a. The Si-Cl bonds (2.1271(7) and
2.1170(7) Å) are also shorter than in 1a,b because the
The molecular structure of the complex Cp*(Me2-
PriP)Ru(H)2(SiCl2Me) (2c), obtained according to eq 1,
is analogous to that of 2a and has been deposited in
(47) (a) van Buuren, G. N.; Willis, A. C.; Einstein, F. W. B.; Peterson,
L. K.; Pomeroy, R. K.; Sutton, D. Inorg. Chem. 1981, 20, 4361. (b) Zlota,
A. A.; Frolow, F.; Milstein, D. Chem. Commun. 1989, 1826. (c)
Yamashita, H.; Kawamoto, A. M.; Tanaka, M.; Goto, M. Chem. Lett.
1990, 2107. (d) Roy, A. K.; Taylor, R. B. J. Am. Chem. Soc. 2002, 124,
9510.
(48) Schubert, U.; Rengstl, A. J. Organomet. Chem. 1979, 166, 323.
(49) Lemke, F. R.; Simons, R. S.; Youngs, W. J. Organometallics
1996, 15, 216.
(46) For an example of Si-Cl addition to a metal, see: Campion, B.
K.; Falk, J.; Tilley, T. D. J. Am. Chem. Soc. 1987, 109, 2049.

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 593
the Supporting Information. The selected molecular
parameters are given in Table 2. The main difference
between 2a and 2c is in the values of the Ru-Si and
Si-Cl bond lengths. Although 2c contains a less bulky
phosphine and thus is less sterically strained, its Ru-
Si bond of 2.3099(9) Å is somewhat longer than in 2a
(2.2950(5) Å). Similtaneously, the Si-Cl bonds are
significantly shorter in 2c (2.108(2) and 2.109(2) Å
versus 2.1170(7) and 2.1271(7) Å in 2a). These trends
can be rationalized in terms of decreased IHI in 2c due
to the presence of a less basic phosphine and hence the
diminished basicity of the hydride ligand. A shorter Ru-
Si bond in 2a leads to a longer trans Ru-P bond
(2.3237(5) versus 2.2888(9) Å in 2c). However, an
alternative explanation of these structural differences
is possible, given the fact that the bulky phosphine Pri3P
in 2a suffers from a greater steric repulsion from the
Cp* ligand, resulting in a more open P-Ru-X bond
angle of 132.8° (where X is the centroid of the Cp* ring;
the corresponding value in 2c is 130.4°) and a longer
Ru-P bond length. This and the slightly decreased
P-Ru-Si bond angle (102.1° in 2a versus 101.8° in 2c)
should lead to a weaker phosphine trans-effect in 2a
compared with 2c. Hence, the former complex can
accommodate a shorter Ru-Si bond length, which in
turn should lead to longer Si-Cl bond lengths for both
steric (to minimize the repulsion from the Cp* ligand)
and electronic reasons (Bent’s rule effect and the pos-
sibility of a stronger IHI with the hydrides). Both
electronic effects should result in a greater Si p-
character in the Si-Cl bonds, which also has its
manifestation in slightly smaller Ru-Si-Cl and Cl-
Si-C bond angles and larger Ru-Si-C bond angles in
2a compared to 2c. At the moment it is difficult to
rationalize which factor (sterically induced diminished
phosphine trans effect or increased IHI) in 2a is the
cause and which is the effect of the observed structural
differences between 2a and 2c.
3. Reactions of Ruthenium Trihydrides with
HSiCl3. The reactions of the trihydrides Cp*(R3P)Ru-
(H)3 (R3 ) Pri3 (a), MePri2 (b), Me2Pri (c), Me2Ph (d))
with the silane HSiCl3 also crucially depend on the
conditions employed and in general result in several
products. The room-temperature reaction of Cp*(R3P)-
Ru(H)3 with excess HSiCl3 in toluene gives good yields
of complexes Cp*(R3P)Ru(Cl)(SiCl3)(H) (5, eq 4). These
compounds have been characterized by NMR and IR
spectroscopy and X-ray studies for 5b,c,d. Complex 5a
has been independently prepared by the addition of
HSiCl3 to Cp*(Pri3P)Ru(Cl). The normal value for the
P-H coupling constant (range 29.1-34.2 Hz) and the
absence of a significant Si-H coupling allows us to rule
out an alternative formulation of 5 as silane σ-complex-
es. In contrast, in the related cationic silane σ-complex
[Cp(Me3P)2Ru(η2-H-SiCl3)]+, having the phopshine ligand
in place of chloride in 5, the decreased J(P-H) ) 11 Hz
and increased J(Si-H) ) 48 Hz have been observed.23
NMR monitoring of the reaction between Cp*(Pri3P)-
Ru(H)3 and excess HSiCl3 (5 equiv) in a thoroughly dried
NMR tube in benzene-d6 at room temperature during
one week showed the formation of a 1:1 mixture of 5a
and a new product, Cp*(Pri3P)Ru(H)2(SiHCl2) (6a).
Prolonged storage of a solution of the mixture of 5 and
6 in the presence of excess silane HSiCl3 results in the
conversion of 6 to 5, probably due to the chlorination of
the Si-H and Ru-H bonds. Due to the close solubility
properties of 5 and 6, we failed to isolate 6 in pure form;
thus these complexes were characterized by spectro-
scopic methods only. In the 1H NMR spectrum com-
pound 6a exhibits a hydride signal at -11.39 ppm (dd,
J(P-H) ) 28.2 Hz, J(H-H) ) 5.9 Hz) and the SiH
signal at 6.89 ppm (t, J(H-H) ) 5.9 Hz). Carrying out
the reaction of Cp*(Pri3P)Ru(H)3 under similar condi-
tions at 75 °C for 2 h gives a mixture of 5a, 6a, Cp*-
(Pri3P)Ru(H)2(SiCl3), and Cp*(Pri3P)Ru(H)2(SiH2Cl) (7a)
in the ratio 2.1:0.7:1:0.25 along with the unreacted Cp*-
(Pri3P)Ru(H)3 (42%). The identity of complex 7a was
established on the basis of its Ru-H and Si-H signals
1
in the H NMR spectrum (vide infra).
Carrying out the reactions of Cp*(Pri3P)Ru(H)3 with
HSiCl3 in the presence of an amine increases the yield
of the Si-H-containing products. The reaction is slow
at room temperature, but heating the reaction mixture
with added NEt3 at 70 °C affords a mixture of complexes
6a (major product), 5a, and three minor components,
including Cp*(Pri3P)Ru(H)2(SiH2Cl) (7a). NMR monitor-
ing of the reaction of Cp*(MePri2P)RuH3 with HSiCl3
in the presence of NEt3 in C6D6 revealed in addition to
6b and 7b another compound, which on the basis of its
1H NMR data we formulate as an isomer of 6b having
the silyl group cis to phosphine, Cp*(Pri2MeP)Ru(H)2-
(SiHCl2) (6b′). Complex 6b′ exhibits inequivalent hy-
dride signals as broad doublets at -11.04 (J(P-H) )
25.8 Hz) and -11.50 (J(P-H) ) 27.7 Hz) and the Si-H
signal at 6.14 ppm (dd, J(H-H) ) 2.5 Hz, J(H-H) )
5.0 Hz) coupled to two inequivalent hydrides. The ratio
of 6 and 7 formed in this reaction depends on the
conditions used. It appears that increasing the amount
of silane favors the formation of 7.
To avoid any complications arising from the possible
complexation of the amine NEt3 to silane, we have also
carried out the reaction of Cp*(Pri3P)Ru(H)3 with HSiCl3
in the presence of a bulkier amine, NEtPri2. To our
surprise, this reaction gave selectively the compound
7a (eq 5).50 The reaction proceeds smoothly at room
(50) Complexes with the ligand SiH2Cl are rare. See, for example:
(a) Schmitzer, S.; Weis, U.; Ka¨b, H.; Buchner, W.; Malisch, W.; Polzer,
T.; Kiefer, W. Inorg. Chem. 1993, 32, 303. (b) Ref 44. (c) Freeman, S.
T. N.; Lofton, L. L.; Lemke, F. R. Organometallics 2002, 21, 4776.

594 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
temperature too. The Si-H signal of 7a in the 1H NMR
spectrum displays a triplet at 5.88 ppm (t, J(H-H) )
2.4 Hz), and the hydride signal is found at -12.20 ppm
(dt, J(P-H) ) 27.9 Hz, J(H-H) ) 2.4 Hz). The reaction
of the trideuteride Cp*(Pri3P)Ru(D)3 with HSiCl3 in the
presence of NEtPri2 during 24 h gives a partially
deuterated product, Cp*(Pri3P)Ru(H)1.21(D)0.79(SiH1.48
-
D0.52Cl).
Given the facile preparation of H2SiCl2*teeda (teeda
) tetraethylethylenediamine) upon reaction of HSiCl3
with teeda,51 we considered that other amines, NEt3 and
NEtPri2, also could cause such a redistribution reaction,
affording silanes amenable to give 6 and 7 by Si-H
oxidative addition. To check this hypothesis, the room-
temperature and thermal reactions of HSiCl3 with NEt3
and NEtPri2 have been studied by NMR. In both cases
the formation of some amount of a white amorphous
precipitate, presumably the adduct of HSiCl3 with the
amine, was observed.52 No Si-H-containing products
apart from the starting HSiCl3 were found in the room-
temperature reaction with NEt3, and only traces of H2-
SiCl2 were observed after heating for 15 h at 65 °C. In
contrast, both the room-temperature and thermal reac-
tions (15 h at 65 °C) of HSiCl3 with NEtPri2 gave partial
conversion to H2SiCl2 characterized by its Si-H signal
at 4.78 ppm (J(Si-H) ) 306 Hz) in the 1H NMR
spectrum.53 In both cases the C6D6-soluble part con-
tained about 20% of the redistribution product, sug-
gesting that an equilibrium was reached (due to the
formation of a precipitate, the exact yield cannot be
determined). Thus, in both cases the silanes amenable
to produce 6 and 7 by the Si-H oxidative addition were
not present in any significant amount in the reaction
mixtures. The reason behind the difference in the
chemical behavior of NEt3 and NEtPri2 is not quite clear
at the moment, although we noticed that the redistru-
tion of HSiCl3 is caused only by a bulkier diamine such
as teeda, whereas tmeda (tmeda ) tetramethylethyl-
enediamine) gave only the adduct HSiCl3*tmeda.51b
With the aim of independent preparation of compound
7a we attempted the synthesis of the precursor complex
Cp*(Pri3P)Ru(H)2(SiH3) (8a).54 The reaction of a mixture
of Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a) and Cp*(Pri3P)Ru(H)2-
(SiHCl2) (6a) with LiAlH4 in ether, followed by a
Figure 3. Molecular structure of complex 5b. Thermal
ellipsoids are given at the 50% probability level. Hydrogen
atoms on carbons are omitted for clarity.
workup, gives Cp*(Pri3P)Ru(H)3 and complex 8a in 27%
isolated yield. The identity of the latter compound was
established by spectroscopic methods, and its connectiv-
ity was confirmed by an X-ray study (vide infra). The
1H NMR spectrum of 8a displays a hydride signal at
-12.17 ppm (d, J(P-H) ) 28.8 Hz) and a singlet due to
the Si-H group at 4.02 ppm. It is noteworthy that the
absence of a chlorine substituent at silicon results in
the absence of coupling between the hydrides at the Si
and Ru centers. This can be attributed to the diminished
Si s-contribution in the Ru-Si bond in accordance with
Bent’s rule. The attempted reaction of 8a with excess
ammonium salt [HNMe2Ph]Cl in benzene during 24 h
gave 20% conversion to 7a and a significant amount of
Cp*(Pri3P)RuH3 resulting from the protonation of the
Ru-Si bond. The lack of selectivity limits the prepara-
tive utility of this approach.
The molecular structure of complexe 5b is shown in
Figure 3, and the corresponding figures for 5c and 5d
are deposited in the Supporting Information. In all the
structures, the hydride occupies the position between
the two bulkiest non-Cp substituents, the phosphine and
silyl groups, to minimize the steric strain. Selected
molecular parameters for 5b, 5c, and 5d are gathered
in Table 3. The Ru-Si bond lengths of 2.3153(8),
2.3111(5), and 2.3107(7) Å in 5b, 5c, and 5d, respec-
tively, are somewhat shorter than the corresponding
bond in the related formally Ru(IV) compound [Cp-
(Me3P)2Ru(η2-H-SiCl3)]+ (2.329(1) Å), rationalized to be
a silane σ-complex,23 but longer than the Ru-Si bond
in the Ru(II) compound Cp(Me3P)2Ru(SiCl3) (2.265(5)
Å), in which the bond is further contracted due to the
negative hyperconjugation Ruf(Si-Cl)*.23 The related
(51) (a) Kloos, S. D.; Boudjouk, P. In Inorganic Synthesis; Darens-
bourg, M. Y., Ed.; Wiley: New York, 1998; Vol. 32, p 294. (b) Boudjouk,
P.; Kim, P. B.-K.; Kloos, S. D.; Page, M.; Thweatt, D. J. Chem. Soc.,
Dalton Trans. 1998, 877.
(52) (a) Ault, B. S.; Jeng, M. L. H. Inorg. Chem. 1990, 29, 837. (b)
Kummer, D.; Chaudhry, S. C.; Debaerdemaeker, T.; Thewalt, U. Chem.
Ber. 1990, 123, 945. (c) Kummer, D.; Chaudhry, S. C.; Depmeier, W.;
Mattern, G. Chem. Ber. 1990, 123, 2241. (d) Corriu, R. J. P.; Chuit,
C.; Reye, C.; Young, J. C. Chem. Rev. 1993, 93, 1371.
(54) Complexes with the ligand SiH3 are rare. (a) See ref 50. (b)
Hao, L.; Lebuis, A.-M.; Harrod, J. F. Chem. Commun. 1998, 1089. (c)
Wekel, H.-U.; Malisch, W. J. Organomet. Chem. 1984, 264, C10. (d)
Hagen, A. P.; Higgns, C. R.; Russo, P. J. Inorg. Chem. 1971, 10, 1657.
(d) Petri, S. H. A.; Neumann, B.; Stammler, H.-G.; Jutzi, P. J.
Organomet. Chem. 1998, 553, 317. (e) Jiang, Q.; Carrol, P. J.; Bery,
D. H. Organometallics 1991, 10, 3648. (f) Robiette, A. G.; Scheldrick,
G. M.; Simpson, R. N. F.; Aylett, B. J.; Campbell, J. A. J. Organomet.
Chem. 1968, 14, 279. (g) Rankin, D. W. H.; Robertson, A. J. Organomet.
Chem. 1975, 85, 225. (g) Rankin, D. W. H.; Robertson, A. J. Organomet.
Chem. 1976, 105, 331.
(53) The 1H NMR signal of H2SiCl2 in CDCl3 was reported at 5.40
ppm with J(Si-H) ) 288 Hz, but coordination of teeda causes a high-
field shift to 4.99 ppm (J(Si-H) ) 404 Hz).51a Therefore the observed
signal of H2SiCl2 in C6D6 with the somewhat increased J(Si-H) is most
likely due to the complexed form H2SiCl2*(NEtPri2)x. The simulta-
neously observed signal of HSiCl3 (5.38 ppm (J(Si-H) ) 371 Hz) in
C6D6 versus 5.42 ppm (J(Si-H) ) 370 Hz) was in the normal place.

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 595
Table 3. Bond Lengths (Å) and Angles (deg) for 5b,
5c, and 5d
5b
5c
5d
Ru(1)-Si(1)
2.3152(8)
2.3694(8)
2.4125(7)
2.099(1)
2.092(1)
2.089(1)
1.36(2)
101.79(3)
82.26(3)
85.17(3)
100.01(5)
100.52(5)
99.56(5)
116.74(4)
121.51(4)
115.02(4)
2.3111(5)
2.3231(4)
2.4164(4)
2.0813(7)
2.0945(7)
2.1044(7)
1.49(3)
2.3107(7)
2.3255(6)
2.4234(6)
2.1017(9)
2.0800(9)
2.1018(9)
1.62(3)
107.11(2)
83.47(2)
81.38(2)
101.32(4)
100.47(4)
99.68(4)
114.30(3)
120.90(4)
116.96(3)
Ru(1)-P(1)
Ru(1)-Cl(1)
Cl(2)-Si(1)
Cl(3)-Si(1)
Cl(4)-Si(1)
Ru(1)-H(1)
Si(1)-Ru(1)-P(1)
Si(1)-Ru(1)-Cl(4)
P(1)-Ru(1)-Cl(1)
Cl(2)-Si(1)-Cl(3)
Cl(2)-Si(1)-Cl(4)
Cl(3)-Si(1)-Cl(4)
Cl(2)-Si(1)-Ru(1)
Cl(3)-Si(1)-Ru(1)
Cl(4)-Si(1)-Ru(1)
106.19(2)
81.99(2)
82.700(2)
100.78(3)
101.13(3)
100.39(3)
120.53(3)
115.96(2)
114.98(3)
Figure 4. Molecular structure of complex 8a. Thermal
ellipsoids are given at the 50% probability level. Hydrogen
atoms on carbons are omitted for clarity.
Ru(II) complex (p-tBu2C6H4)(CO)Ru(SiCl3)2, with a π-ac-
ceptor ligand, exhibits longer Ru-Si bonds (2.338(1) and
2.340(1) Å).33c Surprisingly enough, in apparent viola-
tion of Bent’s rule, the Ru-Si bond lengths in 5b, 5c,
and 5d are between the values observed in 2a (2.2950-
(5) Å) and the monochlorosilyl complexes discussed
above (range 2.332-2.364(2) Å, with the exception of
Cp*(Pri3P)Ru(H)2(SiHClMes), having an even shorter
Ru-Si bond of 2.302(3) Å). However, this irregularity
can be rationalized if one takes into account the
increased steric strain in 5 due to the presence of a
bulkier chlorine group on ruthenium in place of hydride
in 5b,c,d, which is expected to result in the elongation
of the Ru-Si bond. This effect might be at least partially
compensated for by the contraction of the Ru atomic
radius caused by the stronger electron-withdrawing
effect of the chlorine group and hence the decrease of
the Ru-ligand distances. However, the comparison of
the molecular parameters of 2c with those of 5c shows
that the latter complex indeed has a longer Ru-P bond
(2.2888(9) versus 2.3231(4) Å), whereas the Ru-Si bond
remains virtually the same (2.3099(9) Å in 2c and
2.3111(5) Å in 5c, respectively), in spite of the presence
of three Cl atoms on Si in 5c versus only two Cl atoms
in 2c, and thus the steric factor appears to dominate.
The explanation in terms of steric effects is further
justified if one compares the rather long Ru-P bond
lengths of 2.3694(8), 2.3231(4), and 2.3255(6) Å in 5b,
5c, and 5d, respectively, with the range 2.2050-
2.3097(9) Å found for other complexes discussed in this
work. The decrease of the Ru-Si bond length along the
series 5b, 5c, and 5d is consistent with the diminishing
steric strain, as is the decrease of the Ru-P bond
lengths on going from 5b (2.3694(8) Å) to 5c (2.3231(4)
Å), whereas further minor elongation of this bond in 5d
(2.3255(6) Å) may reflect the decreased basicity of the
phosphine.
Table 4. Bond Lengths (Å) and Angles (deg) for 8a
Ru(1)-Si(1)
2.3341(6) Ru(1)-P(2)
2.3064(5)
1.57(3)
Ru(1)-H(1)
1.55(3)
1.43(3)
1.43(3)
Ru(1)-H(2)
Si(1)-H(4)
Si(1)-H(3)
Si(1)-H(5)
Si(1)-Ru(1)-P(2)
P(1)-Ru(1)-H(1)
P(1)-Ru(1)-H(2)
Ru(1)-Si(1)-H(3) 116(1)
Ru(1)-Si(1)-H(5) 113(1)
H(3)-Si(1)-H(5)
1.46(3)
102.03(2) H(1)-Ru(1)-H(2) 110(2)
74(1)
74(1)
Si(1)-Ru(1)-H(1) 65(1)
Si(1)-Ru(1)-H(2) 63(1)
Ru(1)-Si(1)-H(4) 119(1)
H(3)-Si(1)-H(4)
H(4)-Si(1)-H(5)
102(2)
101(2)
103(2)
(2.3064(5) Å) and the P-Ru-Si bond angle (102.03(2)°)
are also very close to the corresponding parameters in
1a and 1b (2.3097(9) and 2.3079(7) Å and 102.70(3)° and
104.66(3)°, respectively). The Ru-H bonds (1.55(3) and
1.57(3) Å) and the Si-H bonds (range 1.43-1.46(3) Å)
in 8 are normal.
4. Discussion of the Interaction of Ruthenium
Trihydrides with Chlorosilanes. It is obvious that
the reactions of the trihydrides Cp*(R3P)Ru(H)3 with
chlorosilanes occur in a complex manner and are ac-
companied by redistribution processes at the silyl
center. We have anticipated three reaction pathways for
this interaction shown in Scheme 1. The simpliest
reaction is based on the thermally induced elimination
of dihydrogen from Cp*(R3P)Ru(H)3 to give a transient
complex Cp*(R3P)RuH amenable to the oxidative addi-
tion of the H-Si bond of a silane (path a). This
mechanism is the most likely one for the formation of
compounds 1, although the overall cause of the reaction
is complicated by a redistribution at the silicon center
to give 2. There is a clear trend that the diminished
steric bulkiness of the phosphine ligand facilitates the
Me/Cl exchange in the silyl ligand. At the moment we
have no working hypothesis how this exchange occurs.
It is also noteworthy that the reactions of the silanes
HSiMeCl2 and HSiCl3 with the trihydrides Cp*(R3P)-
Ru(H)3 proceed at noticeably lower temperatures (60 °C
and room temperature, respectively) than the analogous
reactions of HSiMe2Cl (90 °C). Taking into account that
any thermally induced elimination of dihydrogen from
Cp*(R3P)Ru(H)3 takes place only at temperatures above
90 °C, these results appear to be rather paradoxal.
However, the elimination of dihydrogen from the tri-
hydride can be facilitated by the coordination of a Lewis
acidic silane to the Ru-H bond. Such a Lewis acid-
The molecular structure of compound 8a is presented
in Figure 4, and selected molecular parameters are
gathered in Table 4. The molecular geometry is very
much the same as in complexes 1a and 1b discussed
above. The Ru-Si bond of 2.3341(6) Å is comparable in
length to the corresponding bonds in 1a and 1b, sug-
gesting that the electron-accepting ability of three
hydrogen atoms in 8 (the sum of Tolman’s electronic
parameter is 24.9)44 is of the same magnitude as that
of the Me2Cl set in 1a and 1b (the sum of Tolman’s
electronic parameter is 20.0).44 The Ru-P bond length

596 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
Scheme 1
promoted elimination of dihydrogen has been predicted
in a theoretical study.55
such a possibility cannot be a priori ruled out. Therefore
route b can, in principle, account for the formation of
complexes 3 and 5, if one assumes that the Si-H bond
in the initially formed complexes Cp*(MePri2P)Ru(Cl)-
(SiHRCl)(H) (R ) Me, Cl) can be chlorinated by excess
chlorosilane. An argument against this pathway is
based on the more forced conditions (100 °C), required
in the reaction of MeSiCl3, than those used in the
preparation of complexes 3 and 5 (60 °C and room
temperature, respectively).
The second mechanism in Scheme 1 (path b) differs
from the first one in that the Si-Cl bond addition
happens in preference to the Si-H bond addition.
Usually, the stronger and kinetically more inert Si-Cl
bond is less prone to oxidative addition than the Si-H
bond. However, given the literature precedents46 and
the addition of MeSiCl3 to the compound Cp*(MePri2P)-
Ru(H)3 to give Cp*(MePri2P)Ru(Cl)(SiMeCl2)(H) (3b),
(55) (a) Camanyes, S.; Maseras, F.; Moreno, M.; Lledo´s, A.; Lluch,
J. M.; Bertra´n, J. Chem. Eur. J. 1999, 5, 1166. (b) Camanyes, S.;
Maseras, F.; Moreno, M.; Lledo´s, A.; Lluch, J. M.; Bertra´n, J. Angew.
Chem., Int. Ed. Engl. 1997, 36, 265.
The last mechanism (paths c and d) in Scheme 1 is
based on the direct interaction of a chlorosilane with
the metal-hydride bond.44 This reaction is believed44

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 597
to occur via a hypercoordinate silicon intermediate and,
depending on the basicity of the metal-hydride bond
and the Lewis acidity of the chlorosilane, leads either
to the M-Si43-45 (route c) or to M-Cl (route d) bond
formation.44 The base used to deprotonate the adduct 9
between the trihydride and a chlorosilane can be just
another equivalent of the ruthenium hydride, as it was
observed by Lemke et al. for the related reactions of Cp-
(R3P)2RuH with chlorosilanes.43 In this case, the initially
formed ruthenium coproduct will be the cationic com-
plex [Cp*(R3P)Ru(H2)2]+ (or [Cp*(R3P)Ru(H2)(H)2]+),56
which after the elimination of dihydrogen followed by
the coordination of the chloride anion to [Cp*(R3P)Ru-
(H2)]+ will afford the complex Cp*(R3P)Ru(H)2Cl. The
latter compound is known to be unstable,30 easily
eliminating dihydrogen to give the unsaturated species
Cp*(R3P)RuCl amenable to react with the Si-H bond
of the silane.28,29 Thus, this reaction sequence allows
for an alternative explanation of the formation of
complexes 5 under mild conditions. The room-temper-
ature reaction of Cp*(Pri3P)Ru(H)3 with HSiCl3, afford-
ing a 1:1 mixture of 5a and 6a, and formation of 4 in
the reactions of Cp*(R3P)Ru(H)3 with HSiMeCl2 support
this mechanism. Finally, the reaction pathway (d)
differs from (c) in that the chloride anion substitutes
the silane in the coordination sphere of ruthenium in
[Cp*(R3P)Ru(H2)(H-SiCl2H)]+, affording Cp*(R3P)Ru(H)2-
Cl and eventually 5 as described above in (c). Appar-
ently, routes (c) and (d) can compete. The observation
of a minor amount of complex Cp*(Pri3P)Ru(H)2(SiH2-
Cl) (7a) along with Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a) and
Cp*(Pri3P)Ru(H)2(SiHCl2) (6a) in the thermal reaction
of Cp*(Pri3P)Ru(H)3 with HSiCl3 lends some support to
the route (d) since this gives 5a and the silane H2SiCl2,
which is a feasible precursor to 7a according to the route
(c) and to 6a via the Si-H bond oxidative addition.
Unexpected results were observed when amines were
used to consume the HCl released.44 The first important
observation is that addition of NEt3 completely stops
the formation of a Ru-Cl bond in the case of HSiMeCl2
and significantly diminishes the formation of complexes
5 in the reactions with HSiCl3. However, in both cases
suppresses the interaction of HSiMeCl2 with the Ru-H
bond, which otherwise leads to the formation of a Ru-
Cl bond in 3. For the more acidic silane HSiCl3, all three
reactions (H-Si addition, H/Si, and H/Cl exchanges)
compete under these conditions and lead to the observed
products Cp*(R3P)Ru(H)2(SiCl3), Cp*(R3P)Ru(H)2(SiHCl2)
(6), and Cp*(R3P)Ru(Cl)(SiCl3)(H) (5), respectively.
Another unexpected feature of the reactions with
amine is their surprising sensitivity to the nature of the
amine employed. The difference in product composition
of the reactions in the presence of NEt3 versus NEtPri2
remained a puzzle to us until we found that the latter
amine easily promotes the formation of H2SiCl2 from
HSiCl3 at room temperature whereas NEt3 does not.
Lemke et al. showed that the H/Si exchange is very
sensitive to steric hindrance of the silane, so one can
expect that the reaction of Cp*(Pri3P)Ru(H)3 with HSiCl3
to give 6a and 6a′ is slower than its reaction with H2-
SiCl2 to give Cp*(Pri3P)Ru(H)2(SiH2Cl) (7a). The facile
room-temperature reaction of Cp*(Pri3P)Ru(H)3 with
HSiCl3 in the presence of a weakly coordinating amine
NEtPri2 to give 7a (eq 5) provides further support to
the H/Si exchange mechanism (route c), as neither the
H-Si addition nor H/Cl exchange products are formed.
The lack of reaction between HSiCl3 and NEt3, but
formation of H2SiCl2 in the analogous reaction with
NEtPri2, showed that the silane precursors HxSiCl4-x
to 6 and 7 through the Si-H oxidative addition reac-
tions (H2SiCl2 and H3SiCl, respectively) are absent in
the reaction mixtures. However, these products could
be formed from the trihydrides by the H/Si exchange
with HSiCl3 and H2SiCl2, respectively.
Conclusions
The initial goal of this study was to prepare a series
of half-sandwich silyl hydride complexes of ruthenium
and to study the occurrence and strength of any H-Si
interaction in these compounds, as a function of the
electronic and steric properties of the substituent at
phosphorus and silicon atoms. The reactions of ruthe-
nium trihydrides Cp*(R3P)RuH3 with chlorosilanes oc-
cur in a complex manner and generally result in several
products. Even for the least Lewis acidic silane used,
HSiClMe2, an unexpected redistribution process at the
silicon center was observed, which led to the formation
of complexes Cp*(R3P)RuH2(SiCl2Me) (2) in addition to
the Si-H addition products Cp*(R3P)RuH2(SiClMe2) (1).
The decrease of the steric bulk of the phosphine ligand
from Pri3P to PriMe2P and PhMe2P appears to be the
dominating factor that facilitates such an exchange
reaction, but its precise mechanism still remains un-
known. With more acidic silanes, HSiCl2Me and HSiCl3,
the formation of the Ru-Cl bond becomes one of the
major reaction routes. An unexpected feature of the
reactions of Cp*(R3P)RuH3 with these silanes is that
they crucially depend on the presence and nature of
added amine. The amines (NEt3 and NEtPri2) are
believed to play a multiple role in this reaction. First,
they reduce the Lewis acidity of silanes, thus either
stopping (in the case of HSiCl2Me) the interaction of the
silane with the Ru-H bond or increasing its selectivity
(in the case of HSiCl3). Second, they serve as external
Lewis bases to consume the HCl released during the
H/Si exchange. And finally, NEtPri2 was found to cause
1
only weak signals in the H NMR spectra attributable
to the H/Si exchange products Cp*(R3P)Ru(H)2(SiHRCl)
(R ) Me, Cl, respectively) were observed. Second, the
reaction requires higher temperatures, and finally, a
formal Si-H addition product is formed in eq 3. These
observations can be explained in the following way. The
addition of an amine to the mixture of Cp*(R3P)Ru(H)3
and HSiCl2Me decreases the effective acidity of the
silane, due to the reversible complexation of the amine
to silane to give an adduct Et3NfSiR3Cl.52 Since the
Ru-H bond in the Ru(IV) complex Cp*(R3P)Ru(H)3 is
less basic than that in the Ru(II) complex Cp(Me3P)2-
Ru(H) studied by Lemke et al.,44 it cannot effectively
compete with the amine for the silicon center to give
adduct 9 in Scheme 1, so that for HSiMeCl2 both the
direct H/Si and H/Cl exchange reactions are suppressed
and the usual sequence of dihydrogen elimination from
Cp*(R3P)Ru(H)3 and the silane Si-H bond addition to
the intermediate Cp*(R3P)Ru(H) becomes favorable
(route (a) in Scheme 1). Thus, the addition of an amine
(56) Grundemann, S.; Ulrich, S.; Limbach, H.-H.; Golubev, N. S.;
Denisov, G. S.; Epstein, L. M.; Sabo-Etienne, S.; Chaudret, B. Inorg.
Chem. 1999, 38, 2550.

598 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
and slowly (1 week) concentrated to 1 mL at room temperature
to give orange crystals. The solution was decanted, and crystals
were washed by 5 mL of cold hexane. Yield: 0.200 g (43%) of
a light yellow compound. The X-ray quality crystals were
obtained by cooling a dilute hexane solution to -30 °C. IR
(Nujol): ν(Ru-H) 1952.0, 2026.0 cm -1. 1H NMR (C6D6): δ 1.81
(d, J(P-H) ) 1.3 Hz, 15, C5(CH3)5), 1.55 (sept, J(H-H) ) 7.0
Hz, 2, PCH(CH3)2), 1.00 (s, 6, SiCH3), 0.91 (dd, J(H-H) ) 7.2
Hz, J(P-H) ) 16.2 Hz, 6, PCH(CH3)2), 0.85 (d, J(P-H) ) 7.4
Hz, 3, PCH3), 0.72 (dd, J(H-H) ) 6.9 Hz, J(P-H) ) 13.8 Hz,
6, PCH(CH3)2), -12.21 (d, J(P-H) ) 28.6 Hz + J(Si-H) ) 12.9
Hz, 2, RuH2). 13C NMR (C6D6): δ 95.7 (d, J(P-C) ) 1.7 Hz,
C5(CH3)5), 28.5 (d, J(P-C) ) 27.2 Hz, PCH(CH3)2), 18.2 (broad
s, PCH(CH3)2 and PCH3), 16.7 (s, SiCH3), 11.5 (d, J(P-C) )
1.7 Hz, C5(CH3)5). 31P NMR (C6D6): δ 60.0 (s). 29Si NMR
(C6D6): δ 61.5. Anal. Calcd for C19H40ClPRuSi: C 49.17; H
8.69. Found: C 49.21; H 8.65.
a redistribution reaction of the starting silane HSiCl3
to give H2SiCl2.
To probe the occurrence of H-Si interactions in the
silyl hydride derivatives prepared in this work, X-ray
structures of several representatives with different
numbers of chlorine substituents at silicon and different
bulk and basicity of phosphines have been established.
Although, some structural trends in the monocloro- and
dichloro-substituted silyl derivatives are consisent with
the presence of interligand hypervalent interaction
(M-H‚‚‚Si-Cl in 1a and 1b and double interaction
M-H2‚‚‚Si-Cl2 in 2a and 2b), conclusive evidence is
absent. The measurement of NMR Si-H coupling
constants showed values less than 14 Hz in all com-
pounds, which is better in accord with a classical
description of these complexes, although our recent
studies showed that there is no strict correlation
between the magnitude of J(Si-H) and the strength of
interligand interaction.34b,i,40 In conclusion, although
there is still a potential that the Cp*(R3P) fragment can
support the occurrence of H-Si interaction in its silyl
hydride derivatives, a thorough theoretical study is
required to clear up this problem.
Reaction of Cp*(Me2PriP)RuH3 with HSiMe2Cl to Give
Cp*(Me2PriP)RuH2SiMe2Cl (1c) and Cp*(Me2PriP)Ru-
H2SiMeCl2 (2c). To 0.150 g (0.37 mmol) of Cp*(Me2PriP)RuH3
in 20 mL of toluene was added 0.2 mL (1.85 mmol) of HSiMe2-
Cl. The reaction mixture was heated to 90 °C during 3.5 h.
The volatiles were removed in a vacuum to afford a dark red
solid. This material was dissolved in 20 mL of ether, and the
dark red-violet solution was filtered from the red-brown
residue and slowly concentrated to 1 mL at room temperature
to give white crystals. The viscous red-violet solution was
decanted, and the crystals were washed by 2 mL of cold ether.
Yield: 0.060 g of white compound. The NMR check showed
formation of a 1:1 mixture of Cp*(Me2PriP)RuH2SiMe2Cl and
Cp*(Me2PriP)RuH2SiMeCl2. An X-ray quality crystal of Cp*-
Experimental Section
All manipulations were carried out using conventional high-
vacuum or argon-line Schlenk techniques. Solvents were dried
over sodium or sodium benzophenone ketyl and either kept
under argon or distilled into the reaction vessel by high-
vacuum gas-phase transfer. NMR spectra were recorded on
Bruker (1H, 300 MHz; 13C, 75.4 MHz, 29Si 59.6 MHz) and
Varian (1H, 400 MHz; 13C, 100.6 MHz; 31P, 161.9 MHz)
spectrometers. The positions of the 29Si NMR signals of
complexes containing the SiMe groups were determined by
1H-29Si gHMQC experiments. IR spectra were obtained as
Nujol mulls with a FTIR Perkin-Elmer 1600 series spectrom-
eter. RuCl3*(aq) and silanes were obtained from Sigma-
(Me2PriP)RuH2SiMeCl2 was obtained from the ether solution
-1
of the mixture. IR (Nujol): ν(Ru-H) 1968.0 cm
.
Cp*(Me2PriP)RuH2SiMe2Cl (1c). 1H NMR (C6D6): δ 1.80
(s, 15, C5(CH3)5), 1.33 (sept, J(H-H) ) 7.5 Hz, 1, PCH(CH3)2),
1.01 (s, 6, SiCH3), 0.98 (d, J(P-H) ) 8.7 Hz, 6, PCH3), 0.78
(dd, J(H-H) ) 7.5 Hz, J(P-H) ) 16.2 Hz, 6, PCH(CH3)),
-12.13 (d, J(P-H) ) 29.4 Hz + J(Si-H) ) 12.9 Hz, 2, RuH2).
13C NMR (C6D6): δ 95.7 (d, J(P-C) ) 1.8 Hz, C5(CH3)5), 32.4
(d, J(P-C) ) 31.1 Hz, PCH(CH3)), 19.0 (d, J(P-C) ) 20.0 Hz,
PCH3), 18.2 (s, SiCH3), 17.3 (s, PCH(CH3)), 11.4 (s, C5(CH3)5).
57
Aldrich. Complexes Cp*(R3P)RuH3 and phosphines were
1
31P NMR (C6D6): δ 35.6 (s). H-29Si gHMQC (C6D6): 61.9.
prepared according to the literature methods.
Cp*(Me2PriP)RuH2SiMeCl2 (2c). 1H NMR (C6D6): δ 1.77
(s, 15, C5(CH3)5), 1.35 (sept, J(H-H) ) 7.5 Hz, 1, PCH(CH3)2),
1.28 (s, 3, SiCH3), 0.93 (d, J(P-H) ) 9.0 Hz, 6, PCH3), 0.72
(dd, J(H-H) ) 7.5 Hz, J(P-H) ) 15.3 Hz, 6, PCH(CH3)),
Preparation of Cp* (Pri3P)RuH2SiClMe2 (1a). To 0.400
g (1 mmol) of Cp*Ru(PPri3)H3 in 20 mL of toluene was added
1 mL (9 mmol) of HSiMe2Cl. The reaction mixture was heated
to 90 °C during 4 h. The volatiles were removed in a vacuum
to afford a maroon amorphous product. This compound was
dissolved in 20 mL of ether, and the solution was filtered and
slowly (5 days) concentrated to 1 mL at room temperature to
give colorless crystals. The solution was decanted, and crystals
were washed by 5 mL of cold hexane. Yield: 0.150 g (30%).
The X-ray quality crystals were obtained by cooling a dilute
ether solution to -30 °C. IR (Nujol): ν(Ru-H) 1998.0 and
-11.54 (d, J(P-H) ) 29.2 Hz + J(Si-H) ) 11.0 Hz, 2, H). 13
C
NMR (C6D6): δ 96.9 (s, C5(CH3)5), 31.9 (d, J(P-C) ) 32.3 Hz,
PCH(CH3)), 23.8 (s, SiCH3), 19.2 (d, J(P-C) ) 29.3 Hz, PCH3),
17.2 (s, PCH(CH3)), 11.1 (s, C5(CH3)5). 31P NMR (C6D6): δ 33.3
(s). 29Si NMR (C6D6): δ 68.2.
Reaction of Cp*(Me2PhP)RuH3 with HSiMe2Cl. To
0.210 g (0.56 mmol) of Cp*(Me2PhP)RuH3 in 20 mL of toluene
was added 0.3 mL (2.70 mmol) of HSiMe2Cl. The reaction
mixture was heated to 90 °C during 5 h. A specimen was taken
form the toluene solution. The NMR check showed the forma-
tion of a mixture of 1:1:1 Cp*(Me2PhP)RuH2SiMe2Cl (1d), Cp*-
(Me2PhP)RuH2SiMeCl2 (2d), and another yet unidentified
phosphine complex.
2026.0 cm-1
.
1H NMR (C6D6): δ 1.79 (s, 15, C5(CH3)5), 1.81
(dsept, J(H-H) ) 7.4 Hz, J(P-H) ) 15.9 Hz 3, PCH(CH3)2),
0.99 (dd, J(H-H) ) 7.4 Hz, J(P-H) ) 13.2 Hz, 18, PCH(CH3)2),
0.98 (s, 6, Si(CH3)), -12.23 (d, J(P-H) ) 28.0 Hz + J(Si-H)
) 11.7 Hz, 2, RuH2). 13C NMR (C6D6): δ 95.8 (s, C5(CH3)5),
27.9 (br s, P CH(CH3)2), 19.5 (s, PCH(CH3)2), 17.8 (s, Si(CH)),
11.4 (C5(CH3)5). 31P NMR (C6D6): 83.1 (s). 29Si NMR (C6D6): δ
63.3. Anal. Calcd for C21H44ClPRuSi: C 51.25; H 9.01. Found:
C 51.21; H 8.95.
Cp*(Me2PhP)RuH2SiMe2Cl (1d). 1H NMR (C6D6): δ 1.63 (d,
J(P-H) ) 1.5, 15, C5(CH3)5), 1.26 (d, J(P-H) ) 9.1 Hz, 6,
PCH3), 1.01 (s, 6, SiCH3) -12.11 (d, J(P-H) ) 29.5 Hz, 2,
RuH ). 31P NMR (C6D6): δ 18.4 (s).
2
Preparation of Cp*(MePri2P)RuH2SiMe2Cl (1b). To
0.370 g (1 mmol) of Cp*(MePri2P)RuH3 in 20 mL of toluene
was added 1 mL (9 mmol) of HSiMe2Cl. The reaction mixture
was heated to 90 °C during 6 h. The volatiles were removed
in a vacuum to afford a dark red solid. This material was
dissolved in 20 mL of hexane, and the solution was filtered
Cp*(Me2PhP)RuH2SiMeCl2 (2d). 1H NMR (C6D6): δ 1.59
(d, J(P-H) ) 1.8 Hz, C5(CH3)5), 1.36 (s, 3, SiCH3), 1.19 (d, J(P-
H) ) 9.7 Hz, 6, PCH3), -11.55 (d, J(P-H) ) 28.8 Hz, 2, RuH2).
Preparation of Cp*(Pri3P)RuH2SiMeCl2 (2a). To the
solution of the compound Cp*(Pri3P)RuH3 (0.400 g, 1.0 mmol)
in 20 mL of toluene were added NEt3 (0.5 mL, 6.9 mmol) and
HSiMeCl2 (0.82 mL,10 mmol). The reaction mixture was
heated during 14 h to 90 °C to give a misty orange solution.
(57) Suzuki, H.; Lee, D.; Oshima, N.; Moro-oka, Y. Organometallics
1987, 6, 1569.

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 599
NMR test showed the completion of the reaction and formation
of only the final complex. The volatiles were removed in a
vacuum to give an orange-red oil. The product was washed
with 5 × 20 mL of hexane, and the hexane solutions were
decanted, combined, and dried in vacuo to give a red oil. To
this oil was added 10 mL of hexane, and the solution was
decanted and cooled to -30 °C. A greenish-white powder was
formed. The cold solution was decanted to the flask with the
red oil, the mixture was warmed to room temperature, the oil
was stirred in hexane, and the extraction was repeated in this
way six times. This procedure gave 90 mg of light green
crystalline compound. Yield: 18%. The crystals for the X-ray
study were obtained by very slow concentration of a hexane
solution of the product. The complex decomposes in ether
NMR (C6D6): δ 1.78 (d, J(P-H) ) 1.3 Hz, 15, C5(CH3)5), 1.51
(sept, J(H-H) ) 7.0 Hz, 2, PCH(CH3)2), 1.27 (s, 3, SiCH3), 0.90
(dd, J(H-H) ) 7.0 Hz, J(P-H) ) 9.1 Hz, 6, PCH(CH3)2), 0.79
(d, J(P-H) ) 7.9 Hz, 3, PCH3), 0.68 (dd, J(H-H) ) 7.0 Hz,
J(P-H) ) 7.4 Hz, 6, PCH(CH3)2), -11.58 (d, J(P-H) ) 27.6
Hz, 2, RuH2). 13C NMR (C6D6): δ 96.7 (d, J(P-C) ) 1.7 Hz,
C5(CH3)5), 28.0 (d, J(P-C) ) 30.1 Hz, PCH(CH3)2), 23.1 (s,
SiCH3), 17.8 (br s, PCH(CH3)2 and PCH3), 16.3 (s, PCH(CH3)2),
10.8 (s, C5(CH3)5). 31P NMR (C6D6): δ 58.5 (s). Anal. Calcd for
C18H37Cl2PRuSi: C 44.62; H 7.70. Found: C 44.71; H 7.68.
Reaction of Cp*(Me2PhP)RuH3 with HSiMeCl2 to Give
Cp*(Me2PhP)RuH2SiMeCl2 (2d). To 20 mL of a toluene
solution of complex Cp*(PhMe2P)RuH3 (0.100 g, 0.26 mmol)
were added NEt3 (0.2 mL, 2.6 mmol) and HSiMeCl2 (0.2 mL,
2.6 mmol). The reaction mixture was heated under stirring
during 4 h to 90 °C. All volatiles were removed in vacuo, and
the residue was extracted by 15 mL of ether. An NMR
spectrum showed formation of a mixture of products: Cp*-
(Me2PhP)RuH2SiMeCl2, Cp*(Me2PhP)RuH2SiMeHCl along with
a smaller amount of Cp*(Me2PhP)Ru(Cl)(SiMeCl2)(H), Cp*(Me2-
PhP)RuH2SiCl3, and the starting Cp*(Me2PhP)RuH3. Ether
was removed in vacuo, and the mixture was redissolved in 20
mL of toluene. HSiMeCl2 was added (1 mL, 13 mmol), and the
reaction mixture was heated for a further 20 h to 90 °C. This
procedure resulted in major decomposition; the only hydride
compounds left were Cp*(Me2PhP)Ru(Cl)(SiMeCl2)(H) and
Cp*(Me2PhP)RuH2SiMeCl2.
1
solution. IR (Nujol): ν(Ru-H) 2010.0, 2081.0 cm-1. H NMR
(C6D6): δ 1.81 (dsept, J(P-H) ) 7.2 Hz, J(H-H) ) 7.0 Hz, 3,
PCH(CH3)2), 1.78 (s, 15, C5(CH3)5), 1.22 (s, 3, SiCH3), 0.93 (dd,
J(P-H) ) 13.2 Hz, J(H-H) ) 7.0 Hz, 18, PCH(CH3)2), -11.55
(d, J(P-H) ) 27.9 Hz, 2, RuH2). 13C NMR (C6D6): δ 97.1 (d,
J(P-C) ) 1.8 Hz, C5(CH3)5), 27.9 (d, J(P-C) ) 22.0 Hz, PCH-
(CH3)), 22.8 (s, SiCH3), 19.4 (s, PCH(CH3)2), 11.1 (s, C5(CH3)5)).
31P NMR (C6D6): δ 82.0 (s). 29Si NMR (C6D6): δ 69.9. Anal.
Calcd for C20H41Cl2PRuSi: C 46.86; H 8.06. Found: C 46.98;
H 8.01.
Decomposition of Cp*(Pri3P)RuH2SiMeCl2 in Ether.
The crude compound prepared as above in toluene was
dissolved in 20 mL of ether. The resulting deep blue solution
was cooled to -30 °C to give white crystals. The cold solution
was decanted, and the white crystals were dried in a vacuum.
The NMR test showed the formation of a mixture of Cp*-
(Pri3P)RuH2SiMeCl2 and another yet unidentified compound.
Attempted recrystallization of this material in ether revealed
a steady decrease of solubility and increasing formation of the
second product, which is poorly soluble in ether, contaminated
Cp*(Me2PhP)RuH2SiMeHCl (4d). 1H NMR (C6D6): δ 6.45
(mult, J(HSiMe-H) ) 3.4 Hz, 1, SiHMeCl), 1.60 (d, J(P-H) )
1.2 Hz, C5(CH3)5), 1.21 (d, J(P-H) ) 9.7 Hz, 6, PCH3), 1.15 (d,
J(HSiH-H) ) 3.4 Hz, 3, SiCH3), -11.92 (br d, J(P-H) ) 29.6,
1, RuHa), -12.10 (br d, J(P-H) ) 296, 1, RuHb).
Preparation of Cp*(Pri3P)Ru(Cl)(SiMeCl2)(H) (3a). To
20 mL of a toluene solution of complex Cp*(Pri3P)RuH3 (0.390
g, 0.97 mmol) was added HSiMeCl2 (1 mL, 12 mmol). The
reaction mixture was heated during 1.5 h to 60 °C with
periodical removal of the gas evolved. An NMR test showed
formation of a mixture of complexes Cp*(Pri3P)Ru(Cl)(SiMeCl2)-
(H) (major) and Cp*(Pri3P)RuH2(SiClHMe) (4a) (minor). The
volatiles were removed in vacuo to give a red-orange oil. The
product was dissolved in 20 mL of ether, and to this solution
was added 1.5 mL of HSiMeCl2. The orange solution was
slowly concentrated to 5 mL to afford a yellow tiny crystalline
precipitate. The solution was decanted, and the precipitate was
sequentially washed by 5 mL of ether and 5 mL of hexane.
The product was dried in vacuo to give 0.250 g of a light yellow
crystalline product. The yield was 47%. An alternative prepa-
ration of this compound has been reported.29
1
by some other impurities. The H NMR spectrum in C6D6 of
this product shows a broad signal integrated as 15 and
tentatively assigned to the Cp* ligand and two sets of signals
corresponding to two coordinated phopshine ligands Pri3P. No
hydride signals were observed up to -16 ppm. Please note that
Cp*(Pri3P)2RuCl is not formed upon addition of Pri3P to Cp*-
(Pri3P)RuCl.28
The Second Product Cp*(Pri3P)RuX (X ) unspecified
one-electron ligand, X * H, Cl). 1H NMR (C6D6): δ 2.24
(m, J(H-H) ) 7.2, J(P-H) ) 11.7 Hz, 6, PCH(CH3)2), 1.94 (v
br s, 15), 0.97 (dd, J(H-H) ) 7.2 Hz, J(P-H) ) 16.4 Hz, 32,
PCH(CH3)2). 13C NMR (C6D6): δ 20.1 (d, J(P-C) ) 31.6 Hz,
P(CH(CH3)2)3), 18.4 (s, P(CH(CH3)2)3), 10.6 (br s). 31P NMR
(C6D6): δ 32.6 (br s).
Cp*(Pri3P)Ru(Cl)(SiMeCl2)(H) (3a). IR (Nujol): ν(Ru-
H) 2096.0 cm -1. 1H NMR (toluene-d8): δ 2.22 (d sept, J(P-H)
) 14.1 Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)2), 1.51 (s, 15, C5-
(CH3)5), 1.33 (s, 3, Si(CH3)), 1.14 (dd, J(P-H) ) 13.5 Hz, J(H-
H) ) 6.9 Hz, 9, PCH(CH3)2), 1.02 (br dd, J(P-H) ) 12.2 Hz,
J(H-H) ) 6.9 Hz, 9, PCH(CH3)2), - 9.51 (d, J(P-H) ) 33.6
Hz, 1, RuH). 13C NMR (toluene-d8): δ 100.1 (s, C5(CH3)5), 30.2
(br s, PCH(CH3)2) 27.4 (s, 30.2, PCH(CH3)2)), 27.2 (s, PCH-
(CH3)2), 17.0 (s, Si(CH3)), 10.3 (s, C5(CH3)5). 31P NMR (toluene-
d8): δ 53.6 (s). 29Si (toluene-d8): δ 61.0. Anal. Calcd for
C20H40Cl3PRuSi: C 43.91; H 7.37; Cl 19.44. Found: C 43.54;
H 7.10; Cl 19.13.
Preparation of Cp*(MePri2P)RuH2SiMeCl2 (2b). To 20
mL of a toluene solution of complex Cp*(MePri2P)RuH3 (330
mg, 0.89 mmol) were added NEt3 (0.43 mL, 4.45 mmol) and
HSiMeCl2 (0.73 mL, 8.9 mmol). The reaction mixture was
heated during 12 h to 90 °C to give a misty orange solution.
The NMR test showed formation of a mixture of complexes
Cp*(MePri2P)RuH2SiMeCl2 (major product), Cp*(MePri2P)-
RuH(Cl)SiMe2, and one more yet unidentified compound. The
solution was filtered off from a white precipitate and stripped
of volatiles. The resultant material was extracted by 10 mL of
hexane heated to 40 °C, and the solution was decanted from
the oil. Cooling to -30 °C gave a yellow powder. The cold
solution was transferred to the previous flask with oil, the
mixture was heated to 40 °C, and the oil was thoroughly
stirred. The extraction was repeated in this way 10 times to
give 0.240 g of a yellow product. Since the NMR test showed
that Cp*(MePri2P)RuH2SiMeCl2 was still contaminated with
some imputities, the product was dissolved in 50 mL of ether
and filtered and the solution was slowly concentrated to 5 mL.
This procedure gave a colorless powder and a viscous solution.
The solution was decanted and the residue washed by 5 mL
of cold ether. The yield of colorless crystalline product was
Cp*(PPri3)RuH2(SiMeHCl) (4a). 1H NMR (C6D6): δ 6.09
(dpent, J(HSiMe-H) ) 3.4 Hz, J(HRuHa-H) ) 3.2 Hz, J(HRuHb
-
H) ) 4.9 Hz, J(Si-H) ) 204.6 Hz, 1, SiHMeCl), 1.79 (sept d,
J(H-H) ) 7.2 Hz, 3, PCH(CH3)2), 1.79 (d, J(P-H) ) 1.3 Hz,
15, C5(CH3)5), 1.14 (d, J(HSiH-H) ) 3.4 Hz, 3, SiCH3), 1.08 (dd,
J(H-H) ) 7.2, J(P-H) ) 13.3 Hz, 9, PCH(CH3)2), -11.58 (dd,
J(HSiH-H) ) 4.9, J(P-H) ) 28.6, 1, RuHb), -12.39 (br d, J(P-
H) ) 28.6, 1, RuHa). 31P NMR (C6D6): δ 82.6 (s).
NMR Tube Reaction of Cp*(Pri3P)Ru(Cl)(SiMeCl2)(H)
(3a) with PMe3. To a NMR tube with a solution of 3a in
toluene-d8 (0.6 mL) was added 3 equiv of PMe3. The color
1
0.150 g (36%). IR (Nujol): ν(Ru-H) 1952.0, 1981.0 cm -1. H

600 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
instantaneously changed from light green to bright orange-
yellow. The NMR check showed the formation of Cp*(PMe3)2-
RuCl and the release of free Pri3P and an equivalent of the
silane HSiCl2Me characterized by its Si-H signal at 5.22 ppm
(q, J(H-H) ) 2.1 Hz) and the SiMe signal at 1.50 (d, J(H-H)
and hexane. In a few days red crystals precipitated. The
solution was decanted, and the crystals were washed by 10
mL of cold toluene and dried. Yield: 0.160 g (49%).
(b) To 30 mL of a toluene solution of the complex Cp*(Pri3P)-
RuH3 (0.30 g, 0.75 mmol) was added HSiCl3 (1.0 mL, 1.0
mmol). The reaction mixture was heated for 4 h at 90 °C to
give an orange solution. The volatiles were removed in vacuo
to give a red-orange oil. The produt was dissolved in 20 mL of
toluene, and the solution was filtered, slowly concentrated to
5 mL, and cooled to -30 °C. Red-orange crystals precipitated
from the solution during a few days. The cold solution was
decanted and the residue dried in vacuo. Yield: 0.150 g (35%).
(c) A solution of Cp*(Pri3P)RuCl in 0.6 mL of C6D6 was
treated by a slight excess of HSiCl3. An immediate color change
from blue to orange occurred. The NMR spectrum showed
quantitative formation of Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a). IR
1
) 2.1 Hz). H NMR (toluene-d8): 1.56 (s, 15, C5(CH3)5), 1.25
(vt, J(P-H) ) 7.8 Hz, 18, PMe3). 13C NMR (toluene-d8): 87.8
(s, C5(CH3)5), 20.4 (m, PCH3), 11.0 (d, J(P-C) ) 4.6 Hz, C5-
(CH3)5). 31P NMR (toluene-d8): 3.64 (s).
Preparation of Cp*(MePri2P)Ru(Cl)(SiMeCl2)(H) (3b).
To 20 mL of a toluene solution of complex Cp*(MePri2P)RuH3
(0.370 g, 0.97 mmol) was added HSiMeCl2 (1 mL, 12 mmol).
The reaction mixture was heated during 1.5 h to 60 °C with
periodical removal of the gas evolved. The volatiles were
removed in vacuo to give a red-orange oil. The product was
dissolved in 20 mL of ether, and to this solution was added
1.5 mL of HSiMeCl2. The solution was slowly concentrated to
5 mL to afford an orange solution and a yellow tiny crystalline
precipitate. The solution was decanted, and the precipitate was
sequentially washed by 5 mL of ether and 5 mL of hexane.
The product was dried in vacuo to give 0.220 g of light yellow
crystalline product. The yield was 42%. IR (Nujol): ν(Ru-H)
1
(Nujol): ν(Ru-H) ) 2120.0 cm -1. H NMR (C6D6): δ 2.35 (v
br s, 3, PCH(CH3)), 1.46 (d, J(P-H) ) 1.2 Hz, 15, C5(CH3)5),
1.13 (br dd, J(P-H) ) 14.4 Hz, J(H-H) ) 7.2 Hz, 9, PCH-
(CH3)), 0.98 (br dd, J(P-H) ) 12.3 Hz, J(H-H) ) 6.9 Hz, 9,
PCH(CH3)), -9.47 (d, J(P-H) ) 34.2 Hz, RuH). 13C NMR
(C6D6): δ 101.5 (d, J(P-C) ) 1.7 Hz, C5(CH3)5), 26.9 (d, J(P-
C) ) 21.6 Hz, PCH(CH3)), 21.1 (s, PCH(CH3)), 20.0 (br s, PCH-
(CH3)), 10.1 (s, C5(CH3)5). 31P NMR (C6D6): δ 51.0. Anal. Calcd
for C19H37Cl4PRuSi: C 40.22; H 6.57; Cl 24.99. Found: C 40.64;
H 6.48; Cl 22.46.
1
2076.0 cm -1. H NMR (C6D6): δ 1.87 (d sept, J(H-H) ) 6.9
Hz, J(P-H) ) 18.4 Hz 2, PCH(CH3)2), 1.52 (s, 15, C5(CH3)5),
1.36 (s, 3, Si(CH3)), 1.16 (d, J(P-H) ) 9.9 Hz, 3, PCH3), 1.07
(dd, J(P-H) ) 16.0 Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 1.03
(dd, J(P-H) ) 14.5 Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 0.69
(dd, J(P-H) ) 11.4 Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 0.57
(dd, J(P-H) ) 16.0 Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), -9.86
(d, J(P-H) ) 33.6 Hz, 1, RuH). 13C NMR (C6D6): δ 100.1 (s,
C5(CH3)5), 28.4 (d, J(P-C) ) 31.7 Hz, PCH(CH3)2), 25.6 (d,
J(P-C) ) 19.3 Hz, PCH(CH3)2), 19.0 (s, PCH(CH3)), 18.3 (s,
PCH(CH3)), 17.7 (s, PCH(CH3)), 17.3 (s, PCH(CH3)), 16.8 (d,
J(P-C) ) 7.3 Hz, SiCH3), 10.2 (s, C5(CH3)5), 4.7 (d, J(P-C) )
29.0 Hz, PCH3). 31P NMR (C6D6): δ 45.8 (s). 29Si NMR (toluene-
d8): δ 61.5. Anal. Calcd for C18H36Cl3PRuSi: C 41.66; H 6.99;
Cl 20.49. Found: C 41.59; H 6.94; Cl 19.89.
NMR Tube Reaction of Cp*(Pri3P)RuH3 with HSiCl3
in C6D6. (a) In a thoroughly dried NMR tube was prepared a
solution of Cp*(Pri3P)RuH3 in C6D6, and then HSiCl3 (5 equiv)
was added. In 24 h the NMR spectrum was recorded, which
showed formation of a mixture of Cp*(Pri3P)RuH3 and minor
amounts of Cp*(Pri3P)RuH(Cl)SiCl3 and Cp*(Pri3P)RuH2-
SiHCl2. After 1 week at room temperature a mixture of Cp*-
(Pri3P)Ru(Cl)(SiCl3)(H) and Cp*(Pri3P)RuH2SiHCl2 (1:1) was
formed.
(b) An NMR sample was prepared as above with the ratio
Cp*(Pri3P)RuH3:HSiCl3 ) 1:10. The NMR tube was heated to
75 °C during 2 h; 58% of the starting trihydride reacted, the
products being Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a, 30%) Cp*-
(Pri3P)RuH2(SiCl3) (14%), Cp*(Pri3P)RuH2SiHCl2 (6a, 10.5%),
and Cp*(Pri3P)RuH2SiH2Cl (7a, 3.5%).
Preparation of Cp*(Me2PriP)Ru(Cl)(SiMeCl2)(H) (3c).
To 20 mL of a toluene solution of complex Cp*(Me2PriP)RuH3
(0.160 g, 0.47 mmol) was added HSiMeCl2 (0.38 mL, 4.6 mmol).
The reaction mixture was heated during 1.5 h to 60 °C with
periodical removal of the gas evolved. The volatiles were
removed in vacuo to give a red-orange oil. Then 50 mL of ether
and 1.0 mL of HSiMeCl2 were added to this product. The oil
was thoroughly stirred, and the orange solution was decanted
and slowly concentrated to 10 mL and cooled to -30 °C. Dark
red crystals were formed in a few days. The cold supernatant
solution was decanted, and the precipitate was washed by 5
mL of cold ether. The product was dried in vacuo to give 0.120
g of a dark red crystalline product. The yield was 52%. IR
1
Cp*(Pri3P)RuH2(SiCl3). H NMR (C6D6): δ 1.71 (d, J(P-
H) ) 1.2 Hz, 15, C5(CH3)5), -10.73 (d, J(P-H) ) 27.3 Hz, 2,
RuH2).
1
Cp*(Pri3P)RuH2SiHCl2 (6a). H NMR (C6D6): δ 6.89 (td,
J(H-H) ) 5.9 Hz, J(P-H) ) 1.4 Hz, 1, SiHCl2), 1.78 (d, J(P-
H) ) 1.2 Hz, 15, C5(CH3)5), -11.39 (dd, J(P-H) ) 28.2 Hz,
J(H-H) ) 5.9 Hz, 2, RuH2).
Cp*(Pri3P)RuH2SiH2Cl (7a). 1H NMR (C6D6): δ 5.88 (t,
J(H-H) ) 2.4 Hz + J(Si-H) ) 204 Hz, 2, SiH2Cl), 1.77 (s, 15,
C5(CH3)5), -12.20 (dt, J(P-H) ) 27.9 Hz, J(H-H) ) 2.4 Hz,
2, RuH2).
(Nujol): ν(Ru-H) 2042.0 cm-1 and a shoulder at 1962.0 cm-1
.
1H NMR (C6D6): δ 1.48 (d, J(P-H) ) 1.9 Hz, 15, C5(CH3)5),
1.40 (s, 3, SiCH3), 1.29 (sept, J(H-H) ) 7.0 Hz, 1, PCH(CH3)),
1.07 (d, J(P-H) ) 10.5 Hz, 3, PCH3), 1.03 (d, J(H-H) ) 9.6
Hz, 3, PCH3), 0.85 (dd, J(H-H)) 7.1 Hz, J(P-H) ) 17.4 Hz,
3, PCH(CH3)), 0.66 (dd, J(H-H) ) 7.1 Hz, J(P-H) ) 12.9 Hz,
3, PCH(CH3)), -9.93 (d, J(P-H) ) 30.5 Hz + J(Si-H) ) 20.7
Hz, 1, RuH). 13C NMR (C6D6): δ 95.7 (d, J(P-C) ) 1.8 Hz,
C5(CH3)5), 27.4 (d, J(P-C) ) 33.4 Hz, PCH(CH3)), 17.6 (d, J(P-
C) ) 2.0 Hz, PCH(CH3)), 17.5 (s, SiCH3), 16.6 (d, J(P-C) )
5.4 Hz, PCH(CH3)), 12.4 (d, J(P-C) ) 25.7 Hz, PCH3), 9.7 (s,
C5(CH3)5)) 9.4 (d, J(P-C) ) 37.0 Hz, PCH3). 31P NMR (C6D6):
δ 36.8. 29Si (toluene-d8): 63.0. Anal. Calcd for C16H32Cl3-
PRuSi: C 39.15; H 6.57. Found: C 39.28; H 6.59.
Preparation of Cp*(MePri2P)Ru(Cl)SiCl3(H) (5b). To 20
mL of a toluene solution of the complex Cp*(MePri2P)RuH3
(0.39 g, 1.05 mmol) was added at room temperature HSiCl3
(1.0 mL, 10.5 mmol). In a few minutes a weak gas evolution
was noticed. The reaction mixture was stirred overnight,
affording a yellow solution. The solution was concentrated to
give an orange oil. To the oil was added slowly 20 mL of ether,
which resulted in the precipitation of a yellow compound. The
solution was decanted, and the residue was washed by 10 mL
of toluene and dried in a vacuum. Yield: 0.240 g (42%). X-ray
quality crystals were obtained by slow diffusion of hexane
vapor into a THF solution of the product. IR (Nujol): ν(Ru-
H) 2078.0 cm -1. 1H NMR (C6D6): δ 2.25 (sept, J(H-H) ) 6.9
Hz, 2, PCH(CH3)2), 1.47 (d, J(P-H) ) 0.9 Hz 15, C5(CH3)5),
1.35 (d, J(P-H) ) 10.2 Hz, 3, PCH3), 1.13 (dd, J(P-H) ) 16.2
Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 0.97 (dd, J(P-H) ) 14.7
Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 0.61 (dd, J(P-H) ) 12.0
Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), 0.57 (dd, J(P-H) ) 16.2
Hz, J(H-H) ) 6.9 Hz, 3, PCH(CH3)), -9.76 (d, J(P-H) ) 34.2
Preparation of Cp*(Pri3P)Ru(Cl)(SiCl3)(H) (5a). (a) To
30 mL of a toluene solution of the complex Cp*(Pri3P)RuH3
(0.230 g, 0.58 mmol) was added at room temperature HSiCl3
(0.6 mL, 5.9 mmol). In a few minutes gas evolution started.
The reaction mixture was left overnight at room temperature.
The volatiles were removed in vacuo to give a red oil. This
product was dissolved in 20 mL of a 1:1 mixture of benzene

Ruthenium Silyl Hydrides
Organometallics, Vol. 24, No. 4, 2005 601
1
Hz, 1, RuH). 13C NMR (C6D6): δ 101.4 (s, C5(CH3)5), 28.4 (d,
J(P-C) ) 33.7 Hz, PCH(CH3)2), 25.6 (d, J(P-C) ) 19.3 Hz,
PCH(CH3)2), 19.1 (s, PCH(CH3)), 18.2 (s, PCH(CH3)), 17.5 (s,
PCH(CH3)), 17.3 (s, PCH(CH3)), 10.0 (s, C5(CH3)5), 4.2 (d, J(P-
C) ) 30.3 Hz, PCH3). 31P NMR (C6D6): δ 44.0. 1H-29Si gHMQC
(C6D6): 29Si signal coupled to hydride at -9.76: 35.8. Anal.
Calcd for C17H33Cl4PRuSi: C 37.85; H 6.17; Cl 26.29. Found:
C 37.95; H 6.19; Cl 26.29.
Cp*Ru(PiPr3)H2SiHCl2 (6a). H NMR (C6D6): δ 6.89 (td,
J(H-H) ) 5.9 Hz, J(P-H) ) 1.4 Hz +J(Si-H) ) 254.6 Hz, 1,
SiHCl2), 1.79 (sept d, J(H-H) ) 7.0 Hz, 3, PCH(CH3)2), 1.78
(d, J(P-H) ) 1.2 Hz, 15, C5(CH3)5), 0.93 (dd, J(H-H) ) 7.0
Hz, J(P-H) ) 13.5 Hz, 18, PCH(CH3)2), -11.39 (dd, J(P-H)
) 28.2 Hz, J(H-H) ) 5.9 Hz, 2, RuH2]. 31P NMR (C6D6): δ
81.5.
Generation of Cp*(MePri2P)RuH2SiHCl2 (6b). To 5 mL
of a toluene solution of Cp*(MePri2P)RuH3 (0.330 g, 0.89 mmol)
was added first 0.1 mL of NEt3 (0.98 mmol) and then 0.88 mL
of HSiCl3 (8.9 mmol). The reaction mixture was heated to 65
°C for 2.5 h in a sealed ampule to afford a misty orange
solution. NMR spectra revealed a mixture of Cp*(MePri2P)RuH2-
SiHCl2 (6b′), Cp*(MePri2P)RuH2SiHCl2 (6b) (major product),
and Cp*(MePri2P)RuH2SiH2Cl (7b). Although Cp*(MePri2P)-
RuH2SiHCl2 (6b) was the main product, all attempts to
separate the mixture by crystallization failed.
Preparation of Cp*(Me2PriP)Ru(Cl)(SiCl3)(H) (5c). To
20 mL of a toluene solution of the complex Cp*(Me2PriP)RuH3
(0.11 g, 0.32 mmol) was added at room temperature HSiCl3
(0.32 mL, 3.2 mmol). In a few minutes a weak gas evolution
was noticed. The reaction mixture was stirred overnight,
affording a yellow solution. The solution was dried in vacuo
and the residue dissolved in 5 mL of THF. Then slowly, trying
to avoid any stirring, was added 0.5 mL of HSiCl3 followed by
10 mL of hexane. The system was cooled to -30 °C, trying
not to mix the layers. In a few days dark orange crystals were
formed. The solution was decanted and the residue washed
by 5 mL of toluene and dried in vacuo. The yield of red
crystalline substance: 0.100 g (61%). X-ray quality crystals
were obtained by slow diffusion of hexane vapor into a THF
solution of the product. IR (Nujol): ν(Ru-H) 2056.0 cm -1. 1H
NMR (C6D6): δ 1.41 (d, J(P-H) ) 1.9 Hz, 15, C5(CH3)5), 1.27
(d, J(P-H) ) 10.8 Hz, 3, PCH3), 1.23 (sept, J(H-H) ) 6.9 Hz,
1, PCH(CH3)), 0.95 (d, J(H-H) ) 9.9 Hz, 3, PCH3), 0.85 (dd,
J(H-H) ) 6.9 Hz, J(P-H) ) 17.3 Hz, 3, PCH(CH3)), 0.63 (dd,
J(H-H) ) 6.9 Hz, J(P-H) ) 13.5 Hz, 3, PCH(CH3)), -9.74
(d, J(P-H) ) 30.9 Hz, 1, RuH). 13C NMR (C6D6): δ 100.7 (s,
C5(CH3)5), 27.7 (d, J(P-C) ) 33.9 Hz, PCH(CH3)), 17.6 (s, PCH-
(CH3)), 16.6 (d, J(P-C) ) 1.4 Hz, PCH(CH3)), 12.4 (d, J(P-C)
) 25.7 Hz, PCH3), 9.6 (s, C5(CH3)5)) 9.2 (d, J(P-C) ) 33.9 Hz,
PCH3). 31P NMR (C6D6): δ 35.3. 1H-29Si gHMQC (C6D6): 29Si
signal coupled to H signal at -9.74 ppm is 33.3 ppm. Anal.
Calcd for C15H29Cl4PRuSi: C 35.23; H 5.72; Cl 27.73. Found:
C 35.30; H 5.74; Cl 27.71.
Cp*(MePri2P)RuH2SiHCl2 (6b). IR (Nujol): ν(Si-H) 2248.0
and ν(Ru-H) ) 1990.0 cm -1. 1H NMR (C6D6): δ 7.09 (td, J(H-
H) ) 5.6 Hz, J(P-H) ) 1.0 Hz, SiHCl2), 1.78 (d, J(P-H) ) 1.5
Hz, 15, C5(CH3)5), 1.79 (sept, J(H-H) ) 7.0 Hz, 2, PCH(CH3)2),
0.84 (dd, J(H-H) ) 7.0 Hz, J(P-H) ) 16.1 Hz, 6, PCH(CH3)2),
0.79 (d, J(P-H) ) 8.3 Hz, 3, PCH3), 0.65 (dd, J(H-H) ) 7.0
Hz, J(P-H) ) 14.2 Hz, 6, PCH(CH3)2), -11.39 (dd, J(P-H) )
28.2 Hz, J(H-H) ) 5.6 Hz, 2, RuH2). 31P NMR (C6D6): δ 57.6
(s).
Cp*(MePri2P)RuH2SiHCl2 (6b′). H NMR (C6D6): δ 6.14
1
(dd, J(H-H) ) 2.5 Hz, J(H-H) ) 5.0 Hz, 1, SiH), 1.77 (s, 15,
C5(CH3)5), -11.04 (br d, J(P-H) ) 25.8 Hz, 1, RuH), -11.50
(br d, J(P-H) ) 27.7 Hz, 1, RuH), other signals are obscured.
31P NMR (C6D6): δ 56.2.
Cp*(MePri2P)RuH2SiH2Cl (7b). H NMR (C6D6): δ 6.12
(t, J(H-H) ) 2.5 Hz, SiH2Cl), 1.75 (s, 15, C5(CH3)5), -12.13
(d, J(P-H) ) 29.00 Hz, 2, RuH2), other signals are obscured
by the signals of other compounds. 31P NMR (C6D6): δ 59.7.
1
Preparation of Cp*(Pri3P)RuH2SiH2Cl (7a). To a solu-
tion of complex Cp*(Pri3P)RuH3 (0.310 g, 0.78 mmol) in 20 mL
of toluene was added first NEtPri2 (2.00 g, 15.0 mmol) and
then HSiCl3 (1.73 mL, 17.5 mmol). The reaction mixture was
heated during 4 h to 60 °C. The solution was filtered, and the
crystalline residue was washed by 10 mL of toluene. Volatiles
were removed in vacuo from the combined fractions, and the
material thus obtained was extracted twice by 10 mL of
hexane. The solution was filtered and dried in vacuo to give
0.320 g of a gray crustalline product. Yield: 62%. IR (Nujol):
ν(Si-H) 2095, 2074 cm-1; ν(Ru-H) 1994, 1968 cm-1. 1H NMR
(C6D6): δ 5.88 (t, J(H-H) ) 2.4 Hz + J(Si-H) ) 204 Hz, 2,
SiH2Cl), 1.86 (sept. d, J(H-H) ) 7.4 Hz, 3, P(CH(CH3)2)3), 1.77
(s, 15, C5(CH3)5), 0.97 (dd, J(H-H) ) 7.4 Hz, J(P-H) ) 13.5
Hz, 18, P(CH(CH3)2)3), -12.20 (dt, J(P-H) ) 27.9 Hz, J(H-
H) ) 2.4 Hz, 2, RuH2). 13C NMR (C6D6): δ 92.5 (s, C5(CH3)5),
27.7 (br s, P(CH(CH3)2)3), 14.9 (s, P(CH(CH3)2)3), 9.1 (C5(CH3)5).
31P NMR (C6D6): δ 83.9. Anal. Calcd for C19H40ClPRuSi: C
49.17; H 8.69. Found: C 49.31; H 8.73.
NMR Reaction of Cp*(MeiPr2P)RuH3 with HSiCl3 in
the Presence of NEt3. To a solution of Cp*(MeiPr2P)RuH3
in C6D6 were sequentially added NEt3 and HSiCl3. Only
insignificant reaction occurs at room temperature (4%). The
mixture was then heated at 60 °C until the starting trihydride
was consumed, giving a mixture of Cp*(MeiPr2P)RuH2SiHCl2
(6b and its cis isomer 6b′) and Cp*(MeiPr2P)RuH2SiH2Cl (7b)
with the ratio 6b:6b′:7b ) 2.3:1.34:1.
Preparation of Cp*(Me2PhP)Ru(Cl)(SiCl3)(H) (5d). To
40 mL of a 1:1 mixture of toluene/hexane solution of Cp*(Me2-
PhP)RuH3 (0.300 g, 0.81 mmol) was added 1 mL of HSiCl3,
resulting in the precipitation of a white voluminous compound
and intensive gas evolution. In 10-15 min the precipitate
dissolved, and a yellow solution and red oil were formed. The
reaction mixture was left overnight. The yellow solution was
decanted from the oil and cooled to -50 °C. In 1 h a yellow-
green microcrystalline precipitate was formed. The cold solu-
tion was decanted and added to the oil formed at the previous
stage. The oil was stirred under the solution and allowed to
stay for 1 h at room temperature.Then the solution was added
to the yellow-green precipitate, and the mixture was cooled to
-50 °C. In 1 h the cold solution was decanted and the produt
dried in vacuo. Yield: 0.280 g (63%). The X-ray quality crystals
were obtained by slow diffusion of hexane vapor into a dilute
THF solution of the product. IR (Nujol): ν(Ru-H) 2018.0 cm-1
.
1H NMR (C6D6): δ 7.32 (m, 2, o-Ph), 6.96 (m, 3, m, p-Ph), 1.50
(d, J(P-H) ) 10.8 Hz, 3, PCH3), 1.42 (d, J(P-H) ) 10.5 Hz, 3,
PCH3), 1.25 (s, 15, C5(CH3)5), -9.57 (d, J(P-H) ) 29.1 Hz, 1,
RuH). 13C NMR (C6D6): δ 130.8 (d, J(P-C) ) 9.6 Hz, i-PhP)
130.0 (s, o-Ph), 100.6 (s, C5(CH3)), 20.7 (d, J(P-C) ) 36.3 Hz,
P(CH3)), 12.9 (d, J(P-C) ) 31.7 Hz, P(CH3)), 9.1 (s, C5(CH3)).
31P NMR (C6D6): δ 23.2 (s). Anal. Calcd for C18H27Cl4PRuSi:
C 39.64; H 4.99; Cl 26.00. Found: C 39.46; H 4.99; Cl 25.49.
Generation of Cp*(Pri3P)RuH2SiHCl2 (6a). To 20 mL of
a toluene solution of Cp*(Pri3P)RuH3 (0.400 g, 1 mmol) was
added first 0.05 mL of NEt3 (0.37 mmol) and then 1 mL of
HSiCl3 (10 mmol). The reaction mixture was heated at 70 °C
for 6 h in a sealed ampule. NMR monitoring showed formation
of a mixture of three compounds: Cp*(Pri3P)RuH2SiHCl2, Cp*-
(Pri3P)Ru(H)(Cl)SiCl3, and Cp*(Pri3P)RuH2SiH2Cl (δ -12.20
(dt, J(P-H) ) 27.9 Hz, J(H-H) ) 2.4 Hz, 2, RuH2). Although
Cp*(Pri3P)RuH2SiHCl2 was the main product, all attempts to
separate it from the mixture by crystallization failed.
NMR Reaction of Cp*(Pri3P)RuH3 with HSiCl3 in the
Presence of EtNiPr2. (a) To a solution of Cp*(Pri3P)RuH3 in
C6D6 were added EtNiPr2 and HSiCl3 (about 5-fold excess
each), and the mixture was heated to 50 °C during 1 h. The
1H NMR spectrum showed that Cp*(Pri3P)RuH2SiH2Cl was
formed in 45% yield. Further heating to 50 °C for 3 h gives
90% convertion to Cp*(Pri3P)RuH2SiH2Cl. No other silyl
products were observed.

602 Organometallics, Vol. 24, No. 4, 2005
Osipov et al.
(b) To a solution of Cp*(Pri3P)RuD3 in C6D6 were added EtN-
iPr2 and HSiCl3. The tube was sealed and kept for 24 h at room
temperature. The 1H NMR spectrum showed clean formation
of Cp*(Pri3P)RuHxDySiHzDkCl (x + y ) z + k ) 2). No changes
were observed after the mixture had been heated to 70 °C for
2.5 h or kept at room temperature for 3 weeks.
in 0.6 mL of C6D6. The sample was heated to 100 °C during 2
h to give an intensely colored violet solution. The reaction is
complete and the product is Cp*(MePri2P)RuH(Cl)SiMeCl2. No
traces of other silyl products are seen.
NMR Tube Reaction of Cp*(Pri3P)RuCl with MeSiCl3
in C6D6. To a solution of Cp*(Pri3P)RuH3 in C6D6 was added
[Me2PhNH]+Cl-, and the NMR tube was heated to 50 °C
during 30 min, which resulted in an intensive evolution of
dihydrogen and formation of a violet solution of Cp*(Pri3P)-
RuCl identified by 1H NMR. MeSiCl3 was added to the mixture,
and the solution was further heated to 50 °C for 30 min.
According to the 1H NMR spectrum the reaction does not occur.
Crystal Structure Determinations. Crystals of 1a,b,
2a,c, 5b,c,d, and 8a were covered by polyperfluoro oil and
mounted directly to the Bruker Smart three-circle diffracto-
meter with CCD area detector at 120 K. The crystallographic
data and characteristics of structure solution and refinement
are given in Table 9 included in the Supporting Information.
The structure factor amplitudes for all independent reflections
were obtained after Lorentz and polarization corrections. The
Bruker SAINT program58 was used for data reduction. An
absorption correction based on the SADABS program was
applied. The structures were solved by direct methods59 and
Preparation of Cp*(Pri3P)RuH2SiH3 (8a). (a) A mixture
of Cp*(Pri3P)Ru(Cl)(SiCl3)(H), Cp*(Pri3P)RuH2SiCl3, Cp*-
(Pri3P)RuH2SiHCl2, and Cp*(Pri3P)RuH2SiH2Cl (obtained by
the reaction of Cp*(Pri3P)RuH3 with HSiCl3 in the presence of
NEt3 and containing about 1.0 mmol of ruthenium compounds)
was suspended in 20 mL of ether. The mixture was cooled to
-50 °C, and a precooled solution of LiAlH4 (0.110 g, 2.9 mmol)
and NEt3 (0.3 mL, 4 mmol) in 20 mL of ether was added under
stirring. The reaction mixture was slowly warmed to room
temperature and further stirred for 30 min. Then 10 mL of
toluene was added, and all volatiles were removed in vacuo
(the addition of NEt3 and toluene in this protocol improves
the properties of the residue formed after the removal of the
volatiles). The product thus formed was extracted by 3 × 10
mL of hexane, and the resultant light red solution was filtered.
Degassed water was slowly added to the solution until the
evolution of gas finished. The solution was filtered and hexane
was removed in vacuo to give an oil, from which in few days
coloress crystals were formed. The crystals were quickly
washed by cold ether and dried in vacuo. Yield: 0.120 g (0.27
mmol, about 27%).
(b) The compound was prepared as above by treating Cp*-
(Pri3P)RuH2SiH2Cl (0.07 g, 0.15 mmol) by LiAlH4 (0.01 g, 0.26
mmol) in 10 mL of ether at room temperature. Yield: 0.059 g
(0.14 mmol, 93%). X-ray quality crystals were grown from
ether by slow evaporation of the solution at room temperature.
IR (Nujol): ν(Si-H) 2074, 2036 cm-1; ν(Ru-H) 1994 cm-1. 1H
NMR (C6D6): δ 4.01 (s, 3, SiH3), 1.88 (sept, J(H-H) ) 7.3 Hz,
3, P(CH(CH3)2)3), 1.79 (s, 15, C5(CH3)5), 1.00 (dd, J(H-H) )
7.3 Hz, J(P-H) ) 13.1 Hz, 18, PCH(CH3)2), -12.20 (d, J(P-
H) ) 27.9 Hz, 2, RuH2). 13C NMR (C6D6): δ 94.8 (s, C5(CH3)5),
27.0 (d, J(P-C) ) 22.65 PCH(CH3)2), 19.3 (s, PCH(CH3)2), 11.8
(C5(CH3)5). 31P NMR (C6D6): δ 86.1 (s). Anal. Calcd for C19H41-
PRuSi: C 53.11; H 9.62. Found: C 53.44; H 9.78.
2
refined by full-matrix least-squares procedures, using w(|Fo |
- |Fc2|)2 as the refined function. All hydrogen atoms were found
from the difference maps. All the non-hydrogen atoms were
refined with anisotropic thermal parameters. For 2b all
hydrogen atoms were refined isotropically. For the other
structures non-hydride hydrogen atoms were refined using the
“riding” model and the hydride atoms were refined isotropi-
cally.
Structure 1a displays a disorder on the Cl atom and one of
two Me groups, C(12)H3, at the silicon atom, with the site
occupation factors being 0.74 and 0.26. This disorder resulted
in a reduction of the final accuracy of the structure determi-
nation.
Structure 2c represents a racemic twin with an approxi-
mately equal population of individual phases.
Acknowledgment. Support from the Russian Foun-
dation for Basic Research for G.I.N. (grant no. 00-03-
32850) is gratefully acknowledged. L.G.K. and J.A.K.H.
thank the Royal Society (London) for a Joint Research
Grant, and L.G.K. thanks the Royal Society of Chem-
istry (London) for the RSC Journal Grants for Interna-
tional Authors.
NMR Tube Reaction of Cp*(Pri3P)RuH2SiH3 with
(PhMe2NH)+Cl- in C6D6. To a solution of Cp*(Pri3P)RuH2-
SiH3 in C6D6 was added (PhMe2NH)+Cl-. The mixture was left
at room temperature for 10 h to give a mixture of Cp*(Pri3P)-
RuH3, Cp*(Pri3P)RuH2SiH3, and Cp*(Pri3P)RuH2SiH2Cl.
NMR Tube Reaction of Cp*(MePri2P)RuH3 with Me-
SiCl3 in C6D6. A 1:6 mixture of Cp*(MePri2P)RuH3 and
MeSiCl3 was prepared in 0.6 mL of C6D6. The course of the
reaction was monitored by 1H NMR spectroscopy. No reaction
occurs at room temperature, whereas heating to 70 °C for 1 h
causes only insignificant formation of Cp*(MePri2P)Ru(Cl)-
(SiMeCl2)(H). Further heating to 100 °C for 2 h results in a
complete reaction and formation of Cp*(MePri2P)Ru(Cl)-
(SiMeCl2)(H).
Supporting Information Available: A table with crystal
and structure refinement data and figures of 1a, 2c, 5c, and
5d are included in the Supporting Information. Crystal-
lographic information files (CIF) are available free of charge
via the Internet at http://pubs.acs.org.
OM0495271
NMR Tube Reaction of Cp*(MePri2P)RuH3 with Me-
SiCl3 in the Presence of NEt3 in C6D6. A mixture of Cp*-
(MePri2P)RuH3/MeSiCl3/NEt3 in the ratio 1:6:2.5 was prepared
(58) SAINT, Version 6.02A; Bruker AXS Inc.: Madison, WI, 2001.
(59) SHELXTL-Plus, Release 5.10; Bruker AXS Inc.: Madison, WI,
1997.