Generation of functionally substituted cyclopentadienyl ligands in osmium(IV) chemistry

Article abstract of DOI:10.1021/om000789m

Several types of substituted cyclopentadienyl osmium(IV) complexes are obtained. Their structures are determined by X-ray diffraction analysis. The distribution of ligands around the metallic center can be described with the phosphine and the metalated phenyl group mutually transoid. The novel Nu(Os)/H(C₅H₅) exchange reactions, which afford substituted cyclopentadienyl osmium(IV) complexes are reported. The chemistry of the cyclopentadienyl-osmium complexes is a little known field due to the lack of osmium synthetic precursors.

Full text of DOI:10.1021/om000789m

240
Organometallics 2001, 20, 240-253
Articles
Gen er a tion of F u n ction a lly Su bstitu ted
Cyclop en ta d ien yl Liga n d s in Osm iu m (IV) Ch em istr y†
Miguel Baya, Pascale Crochet, Miguel A. Esteruelas,* and Enrique On˜ate
Departamento de Quı´mica Inorga´nica-Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Received September 14, 2000
Several types of substituted cyclopentadienyl osmium(IV) complexes can be obtained by
reaction of OsH(η5-C5H5)Cl(EPh3)(PiPr3) (E ) Ge (1), Si (2)) with LiNu reagents. Both 1 and
2 react with LiCH2CN. The reactions give OsH2(η5-C5H4EPh3)(CH2CN)(PiPr3) (E ) Ge (3),
Si (4)). The reaction of the perdeuterated cyclopentadienyl complex OsH(η5-C5D5)Cl(SiPh3)-
(PiPr3) (2-d 5) with LiCH2CN affords Os(H)(D)(η5-C5D4SiPh3)(CH2CN)(PiPr3) (4-d 5). Complex
4 reacts with CD3OD to give OsH2(η5-C5H4SiPh3)(CD2CN)(PiPr3) (4-d 2), which can be also
obtained by addition of LiCD2CN to 2. The treatment of 1 with RLi leads to OsH2(η5-
C5H4R)(GePh3)(PiPr3) (R ) CH3 (5), nBu (6), secBu (7)). Under the same conditions, the addition
n
of nBuLi to OsH(η5-C5D5)Cl(GePh3)(PiPr3) (1-d 5) affords Os(H)(D)(η5-C5D4 Bu)(GePh3)(PiPr3)
n
(6-d 5). Complex 2 also reacts with CH3Li and BuLi. In both cases, complex OsH2{η5-C5H4-
Si(C6H4)Ph2}(PiPr3) (8) is obtained. The structure of 8 has been determined by X-ray
diffraction analysis. The distribution of ligands around the metallic center can be described
as a four-legged piano stool geometry with the phosphine and the metalated phenyl group
n
mutually transoid. The treatment at room temperature of 2-d 5 with BuLi leads to a mixture
n
of OsH2(η5-C5D4Si(C6H4)Ph2}(PiPr3) (8-d 4) and Os(H)(D)(η5-C5D4 Bu)(SiPh3)(PiPr3) (9-d 5) in
a 2:1 molar ratio. The reaction of 2 with secBuLi also gives a mixture. In this case, it is
formed by OsH2(η5-C5H4secBu)(SiPh3)(PiPr3) (10) and 8 in a 1:4 molar ratio. The addition of
LiCH2C(O)CH3 to 2 leads to OsH(η5-C5H5)(SiPh2C6H4)(PiPr3) (11). The reactions of 1 with
LiNR2 afford OsH2(η5-C5H4NR2)(GePh3)(PiPr3) (R ) Et (12), allyl (13)), while under the same
conditions 2 gives mixtures of 8 and OsH2(η5-C5H4NR2)(SiPh3)(PiPr3) (R ) Et (14), allyl (15)).
The structure of 13 has been also determined by X-ray diffraction analysis. The distribution
of ligands around the metallic center is also a four-legged piano stool geometry, but in this
case, the phosphine is transoid to GePh3. Both 1 and 2 react with LiPPh2. The reactions
give the cyclopentadienyl phosphine derivatives OsH2(η5-C5H4PPh2)(EPh3)(PiPr3) (E )
Ge (16), Si (17)).
In tr od u ction
rhenium2 and iron,3 germyl, stannyl, and plumbyl from
molybdenum, tungsten, and iron,3e,4 acyl from rhenium5
and iron,6 hydride from rhenium7 and iron,8 acetylide
from iron,9 and phosphorus ligands from iron10 and
ruthenium.11
Transition metal complexes containing a η5-cyclopen-
tadienyl group and monodentate ligands undergo base-
induced migration reactions of a monodentate ligand
from the metal to a neighboring cyclopentadienyl carbon
atom. It is widely accepted that such reactions involve
the initial deprotonation of the cyclopentadienyl ring
followed by the ligand migration. The produced anion
is quenched by reaction with an electrophile (Scheme
1). The first example of this type of migration reaction
was reported by Dean and Graham in 1977 for M(η5-
C5H5)(GePh3)(CO)3 (M ) Mo, W).1 Since then, several
types of migrations have been observed: silyl from
In addition to these reactions, which provide poten-
tially useful approaches to functionally substituted
(2) (a) Pasman, P.; Snel, J . J . M. J . Organomet. Chem. 1986, 301,
329. (b) Crocco, G. L.; Young, C. S.; Lee, K. E.; Gladysz, J . A.
Organometallics 1988, 7, 2158.
(3) (a) Berryhill, S. R.; Sharenow, B. J . Organomet. Chem. 1981, 221,
143. (b) Tum, G.; Ries, W.; Greissinger, D.; Malisch, W. J . Organomet.
Chem. 1983, 252, C67. (c) Berryhill, S. R.; Clevenger, G. L.; Burdurlu,
F. Y. Organometallics 1985, 4, 1509. (d) Pannell, K. H.; Vicenti, S. P.;
Scott, R. C., III. Organometallics 1987, 6, 1593. (e) Sharma, S.;
Cervantes, J .; Mata-Mata, J . L.; Brun, M.-C.; Cervantes-Lee, F.;
Pannell, K. H. Organometallics 1995, 14, 4269.
† Dedicated to Prof. J ose´ Barluenga on the occasion of his 60th
birthday.
(1) Dean, W. K.; Graham, W. A. G. Inorg. Chem. 1977, 16, 1061.
(4) Cervantes, J .; Vicenti, S. P.; Kappor, R. N.; Pannell, K. H.
Organometallics 1989, 8, 744.
10.1021/om000789m CCC: $20.00 © 2001 American Chemical Society
Publication on Web 12/09/2000

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 241
Sch em e 1
where a π-alkyne is not involved, has been reported in
the reaction of a cyclopentadienyl cobalt complex with
MeLi.14
The chemistry of the cyclopentadienyl-osmium com-
plexes is a little-known field15 due to the lack of
convenient osmium synthetic precursors16 and the
higher kinetic inertia of the Os(η5-C5H5)L3 compounds
in comparison with the related iron and ruthenium
species.17
As a part of our study on the chemical properties of
the six-coordinate osmium(IV) complex OsH2Cl2(PiPr3)2,
we have previously reported the synthesis of the cyclo-
pentadienyl osmium compound Os(η5-C5H5)Cl(PiPr3)2.18
Despite the high kinetic inertia of the Os(η5-C5H5)L3
compounds, this complex is a labile starting material
for the development of new cyclopentadienyl osmium
chemistry.19 Thus, in pentane and toluene, the dissocia-
tion of a phosphine ligand is favored, and the resulting
metallic fragment Os(η5-C5H5)Cl(PiPr3) is capable of
activating by oxidative addition HER3 molecules. The
reactions afford osmium(IV) hydride derivatives of the
type OsH(η5-C5H5)Cl(ER3)(PiPr3) (E ) Si, Ge), with a
distribution of ligands around the metallic center that
can be described as a four-legged piano stool geometry.
The thermodynamic stability of the Os-ER3 bonds
depends on the cone angle of the ER3 group and
increases in the sequence Os-Si , Os-Sn < Os-Ge.20
In the search for novel cyclopentadienyl chemistry,
we have now studied the reactivity of the complexes
OsH(η5-C5H5)Cl(EPh3)(PiPr3) (E ) Si, Ge) toward LiNu
nucleophillic reagents. This paper reports novel Nu(Os)/
H(C5H5) exchange reactions, which afford substituted
cyclopentadienyl osmium(IV) complexes.
Sch em e 2
cyclopentadienyl complexes,12 it has been observed that
cyclopentadienyl iron π-alkyne complexes [Fe(η5-C5H5)-
(η2-C2R2)L2]+ add nucleophiles to afford Fe(η5-C5H4-
Nu)(CRdCHR)L2 and/or Fe(η5-C5H5){CRdC(Nu)R}L2
depending upon of the substituents of the alkyne and
the nature of the nucleophile. The formation of the
substituted cyclopentadienyl derivatives involves the
intermolecular exo-addition of the nucleophile to the
cyclopentadienyl ring followed by the intramolecular cis-
addition to the alkyne of the endo-hydrogen of the
cyclopentadiene formed in the first step (Scheme 2).13
A similar type of cyclopentadienyl ring substitution,
Resu lts a n d Discu ssion
1. R ea ct ion s of OsH (η5-C5H 5)Cl(E P h 3)(P iP r 3)
(E ) Ge, Si) w it h LiCH2CN: E P h 3(Os)/H (C5H 5)
E xch a n ge. Complexes OsH(η5-C5H5)Cl(EPh3)(PiPr3)
(E ) Ge (1), Si (2)) react with LiCH2CN in tetrahydro-
(14) Sternberg, E. D.; Vollhardt, K. P. C. J . Org. Chem. 1984, 49,
1564.
(15) (a) Bruce, M. I.; Wong, F. S. J . Organomet. Chem. 1981, 210,
C5. (b) Hoyano, J . K.; May, C. J .; Graham, W. A. G. Inorg. Chem. 1982,
21, 3095. (c) Bruce, M. I.; Tomkins, I. B.; Wong, F. S.; Shelton, B. W.;
White, A. H. J . Chem. Soc., Dalton Trans. 1982, 687. (d) Wilczewski,
T. J . Organomet. Chem. 1986, 317, 307. (e) Bruce, M. I.; Humphrey,
M. G.; Koutsantonis, G. E.; Liddell, M. J . J . Organomet. Chem. 1987,
326, 247. (f) Bruce, M. I.; Koutsantonis, G. E.; Liddell, M. J .; Nicholson,
B. K. J . Organomet. Chem. 1987, 320, 217. (g) Kawano, Y.; Tobita, H.;
Ogino, H. Organometallics 1994, 13, 3849. (h) J ia, G.; Ng, W. S.; Yao,
J .; Lan, C.; Chen, Y. Organometallics 1996, 15, 5039. (i) Shapley, P.
A.; Shusta, J . M.; Hunt, J . L. Organometallics 1996, 15, 1622. (j)
Freedman, D. A.; Gill, T. P.; Blough, A. M.; Koeford, R. S.; Mann, K.
R. Inorg. Chem. 1997, 36, 95. (k) Koch, J . L.; Shapley, P. A. Organo-
metallics 1999, 18, 814.
(16) (a) Bruce, M. I.; Windsor, N. J . Aust. J . Chem. 1977, 30, 1601.
(b) Herrmann, W. A.; Herdtweck, E.; Scha¨fer, A. Chem. Ber. 1988, 121,
1907. (c) Dev, S.; Selegue, J . P. J . Organomet. Chem. 1994, 469, 107.
(17) Atwood, J . D. Inorganic and Organometallic Reaction Mecha-
nisms; VCH Publisher: New York, 1997; Chapter 3.
(18) Esteruelas, M. A.; Lo´pez, A. M.; Ruiz, N.; Tolosa, J . I. Orga-
nometallics 1997, 16, 4657.
(5) (a) Heah, P. H.; Gladysz, J . A. J . Am. Chem. Soc. 1984, 106, 7636.
(b) Heah, P. C.; Patton, A. T.; Gladysz, J . A. J . Am. Chem. Soc. 1986,
108, 1185. (c) Melletti, M. C.; Fenske, R. F. Organometallics 1989, 8,
420.
(6) (a) Abbott, S.; Baird, G. J .; Davies, S. G.; Dordor-Hedgecock, I.
M.; Maberly, T. R.; Walker, J . C.; Warner, P. J . Organomet. Chem.
1985, 289, C13. (b) Akita, M.; Kondoh, A. J . Organomet. Chem. 1986,
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1998, 741.
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8, 1564. (b) Kubo, K.; Nakazawa, H.; Kawamura, K.; Mizuta, T.;
Miyoshi, K. J . Am. Chem. Soc. 1998, 120, 6715.
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Organometallics 1998, 17, 1741.
(13) (a) Reger, D. L.; Belmore, K. A.; Atwood, J . L.; Hunter, W. E. J .
Am. Chem. Soc. 1983, 105, 5701. (b) Reger, D. L.; Belmore, K. A.
Organometallics 1985, 4, 305. (c) Reger, D. L.; Klaeren, S. A.; Lebioda,
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Organometallics 1996, 15, 878. (b) Crochet, P.; Esteruelas, M. A.;
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Ruiz, N. Organometallics 1999, 18, 5034.

242 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
Sch em e 3
furan at room temperature to give the substituted
cyclopentadienyl derivatives OsH2(η5-C5H4EPh3)(CH2-
CN)(PiPr3) (E ) Ge (3), Si (4)), according to eq 1.
The new compounds were isolated as white solids in
about 60% yield. In agreement with the presence of the
substituted cyclopentadienyl ligands, the resonances of
the C5H4 protons in the 1H NMR spectra appear
between 4.80 and 4.30 ppm as AA′BB′ spin systems. In
addition, the spectra show singlets at 2.10 (3) and 1.87
(4) ppm, corresponding to the CH2CN protons, and
doublets at -14.49 (3) and -14.80 (4) ppm with H-P
coupling constants of 28.8 and 27.0 Hz, respectively, due
to the hydride ligands. The presence of only one signal
for the hydrides and the values of the H-P coupling
constants21 are consistent with four-legged piano stool
structures with the hydrides transoid. The 1H NMR
i
spectra show also only one Pr-methyl chemical shift,
suggesting that in solution the substituted cyclopenta-
dienyl groups rotate around the osmium cyclopentadi-
enyl axis. The 13C{1H} NMR spectra are in accordance
with the 1H NMR spectra; thus the cyclopentadienyl
carbon atoms display three signals at about 91 (CEPh3)
and 81 and 78 (CH) ppm. The CH2CN ligand gives rise
to two singlets at 118.3 (CN, 3 and 4) and 16.5 (CH2, 3)
and 15.8 (CH2, 4) ppm. The 31P{1H} NMR spectra
contain singlets at about 41 ppm, which are split into
triplets under off-resonance conditions, by spin coupling
with two equivalent hydrides.
To investigate the mechanism of the process shown
in eq 1, we have carried out the reaction of the per-
deuterated cyclopentadienyl complex OsH(η5-C5D5)Cl-
(SiPh3)(PiPr3) (2-d 5) with LiCH2CN. Treatment of 2-d 5
with LiCH2CN under the same conditions as those
mentioned for the formation of 3 and 4 leads selectively
to Os(H)(D)(η5-C5D4SiPh3)(CH2CN)(PiPr3) (4-d 5), con-
taining a deuteride ligand at the osmium atom (eq 2).
The formation of 4-d 5 suggests that the processes
shown in eqs 1 and 2 proceed via the elemental steps
collected in Scheme 3. The reactions initially involve the
replacement of the Cl- anion by the CH2CN group. The
spontaneous migration of EPh3 from the osmium atoms
into the cyclopentadienyl ligands should afford substi-
tuted cyclopentadiene osmium(II) species, with the EPh3
groups in endo position. Subsequently, these intermedi-
ates could evolve by exo-1,5-hydride (deuteride) shift to
place a hydrogen (deuterium) atom in endo position. The
exo-1,5-hydride shift in η4-C5H6 is precedented.7a,8 Fi-
nally the migration of this endo-hydrogen (deuterium)
atom from the dienes into the osmium atoms should give
3, 4, and 4-d 5.
Although there are not precedents for the spontane-
ous migration of ligands from the metals to coordinated
cyclopentadienyl groups, it has been observed that the
irradiation of Fe(η5-C5H5){CH(OSiMe3)Ph}(CO)2 in the
presence of triphenylphophine leads to Fe{η4-C5H5CH-
(OSiMe)Ph}(CO)2(PPh3), with the alkyl substituent in
exo position.22 Similarly, the irradiation of Fe(η5-C5-
Me5)(η1-CH2Ph)(CO)2 under carbon monoxide atmo-
sphere affords Fe{η4-C5(Me)5CH2Ph}(CO)3 with the
benzyl group also in exo position.23
In solution H/D exchanges between the metal and the
cyclopentadienyl and CH2CN ligands of 4-d 5 are not
observed. However, the CH2CN group of 4 undergoes
intermolecular H/D exchange with methanol-d4, without
affecting the hydride positions. Thus, the stirring of 4
in methanol-d4 at room temperature leads to OsH2(η5-
C5H4SiPh3)(CD2CN)(PiPr3) (4-d 2) in 37% yield after 3
days. This deuterated species could be formed via the
CH2CN-methanol-d4 interaction shown in eq 3.
The presence of a deuterium atom bonded to the
metallic center of 4-d 5 is strongly supported by the H
NMR spectrum of the complex, which shows an AA′BB′
spin system centered at 4.34 ppm (C5D4) and a broad
singlet at -14.89 ppm (Os-D) with a 4:1 intensity ratio.
2
(21) They are typical values for this arrangement: see for example
refs 18 and 19d, and (a) Campion, B. K.; Heyn, R. H.; Tilley, T. D.
Chem. Commun. 1992, 1201. (b) Campion, B. K.; Heyn, R. H.; Tilley,
T. D.; Rheingold, A. L. J . Am. Chem. Soc. 1993, 115, 5527. (c) Rottink,
M. K.; Angelici, R. J . J . Am. Chem. Soc. 1993, 115, 7267. (d) Lemke,
F. R.; Brammer, L. Organometallics 1995, 14, 3980. (e) Grumbine, S.
K.; Mitchell, G. P.; Strauss, D. A.; Tilley, T. D.; Rheingold, A. L.
Organometallics 1998, 17, 5607.
(22) Carpenter, N. E.; Khan, M. A.; Nicholas, K. M. Organometallics
1999, 18, 1569
(23) Blaha, J . P.; Wrighton, M. S. J . Am. Chem. Soc. 1985, 107, 2694.

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 243
In agreement with the presence of a deuterium atom
bonded to the osmium atom of 6-d 5, the 2H NMR
spectrum of this compound shows an AA′BB′ spin
system centered at 4.61 ppm (C5D4) and a broad singlet
at -14.33 ppm (Os-D) with a 4:1 intensity ratio.
3. Reaction s of OsH(η5-C5H5)Cl(SiP h 3)(P iP r 3) with
RLi (R ) CH3, n Bu , secBu ): SiP h 3(Os)/H(C5H5)
Exch a n ge a n d Su bsequ en t C-H Activa tion of a
P h en yl Gr ou p . Treatment of tetrahydrofuran solutions
The most noticeable spectroscopic feature of 4-d 2,
which is also obtained by reaction of 2 with LiCD2CN,
2
is a singlet at 2.15 ppm in the H NMR spectrum.
2. Rea ction s of OsH(η5-C5H5)Cl(GeP h 3)(P iP r 3)
w it h R Li (R ) CH 3, n Bu , secBu ): R (Os)/H (C5H 5)
Exch a n ge. Treatment of tetrahydrofuran solutions of
n
1 with MeLi, BuLi, and secBuLi at room temperature
affords the substituted cyclopentadienyl derivatives
OsH2(η5-C5H4R)(GePh3)(PiPr3) (R ) CH3 (5), nBu (6),
secBu (7)), which were isolated as white solids in good
yield (eq 4).
n
of 2 with MeLi and BuLi at room temperature affords
OsH2{η5-C5H4Si(C6H4)Ph2}(PiPr3) (8), which is a result
of a SiPh3(Os)/H(C5H5) exchange and subsequent C-H
activation of a phenyl of the silyl group. Complex 8 was
isolated as a white solid in 61% yield, according to
eq 6.
In the 1H NMR spectra of 5 and 6, the most noticeable
features are AA′BB′ spin systems between 4.80 and 4.40
ppm, corresponding to the C5H4 protons, and at about
-14.5 ppm doublets with H-P coupling constants of
about 29 Hz, due to the hydride ligands. The presence
of the alkyl substituents at the cyclopentadienyl groups
is strongly supported by the APT 13C{1H} NMR spectra,
which show singlets at 14.4 (+, CH3, 5) and 35.3
(-, CH2, 6) ppm. The 31P{1H} NMR spectra contain
singlets at about 42 ppm, which under off-resonance
conditions are split into triplets by spin coupling with
the two equivalent hydrides.
A view of the molecular geometry of 8 is shown in
Figure 1. Selected bond distances and angles are listed
in Table 1. The hydride ligands H(01) and H(02) were
located in the difference Fourier maps and refined as
isotropic atoms together with the rest of the non-
hydrogen atoms of the structure, giving Os-H(01) and
Os-H(02) distances of 1.54(8) and 1.56(7) Å, respec-
tively.
1
The H NMR spectrum of 7 reveals the asymmetry
i
of the alkyl group, which gives rise to two Pr-methyl
chemical shifts, and inequivalent hydride ligands. Thus,
in the high-field region, the spectrum shows two double
doublets at -14.46 and -14.56 ppm with H-P and
H-H coupling constants of 29.4 and 3.3 Hz, respec-
tively. Furthermore the spectrum contains between 4.80
and 4.40 ppm a complex resonance corresponding to the
cyclopentadienyl protons, two multiplets at 1.62 (CH)
and 1.19 (CH2) ppm, a doublet at 1.08 (J (HH) ) 6.9 Hz,
CH3) ppm, and a triplet at 0.70 (J (HH) ) 7.5 Hz, CH3)
ppm due to the sec-butyl group. In the APT 13C{1H}
NMR spectrum, the most noticeable resonance is a
singlet at 33.3 (+) ppm, corresponding to the CH carbon
atom of the alkyl group. The 31P{1H} NMR spectrum
shows a singlet at 41.3 ppm.
The distribution of ligands around the osmium atom
can be described as a four-legged piano stool geometry
with the hydride ligands disposed mutually transoid
(H(01)-Os-H(02) ) 116(4)°) and the metalated phenyl
group disposed transoid to the triisopropylphosphine
ligand (P-Os-C(6) ) 90.9(3)°). In agreement with this
disposition, the 1H NMR spectrum shows at -12.76 ppm
a doublet with an H-P coupling constant of 36.3 Hz,
for the hydride ligands, and the 13C{1H} NMR spectrum
contains at 140.6 ppm a doublet with a C-P coupling
constant of 6 Hz, due to C(6).
The Os-C(6) bond length of 2.106(7) Å is typical for
an Os-C(aryl) single bond and agrees well with the
values previously found in the complexes OsH{C6H4-2-
The formation of 5-7 involves a sequence of reactions
similar to that shown in Scheme 3, where on OsH(η5-
C5H5)(alkyl)(GePh3)(PiPr3) intermediates, the spontane-
ous migration of the alkyl group (instead EPh3) from
the osmium atom to the cyclopentadienyl group has
taken place. This is supported by the reaction of the
perdeuterated cyclopentadienyl complex OsH(η5-C5D5)-
Cl(GePh3)(PiPr3) (1-d 5) with nBuLi, which leads to
(E-CHdCHPh)}(CO)(PiPr3)2 (2.136(7) Å),24 [OsH(η5-
C5H5){NHdC(Ph)C6H4}(PiPr3)]BF4 (2.10(2) and 2.137-
(19) Å), [OsH(η5-C5H5)(PPh2C6H4)(PiPr3)]BF4 (2.180(9)
and 2.136(9) Å),19d Os(C2Ph){NHdC(Ph)C6H4}(CO)-
Os(H)(D)(η5-C5D4 Bu)(GePh3)(PiPr3) (6-d 5), according to
n
(24) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Sola, E.
J . Am. Chem. Soc. 1996, 118, 89.
eq 5.

244 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
The 1H NMR spectrum contains at -12.76 ppm a
doublet with an H-P coupling constant of 36.3 Hz,
which shows an intensity ratio with regard to the CH
resonance of the phosphine of 2:3, whereas the 2H NMR
spectrum does not contain any resonance in the high-
field region. The H NMR spectrum shows an AA′BB′
spin system centered at 5.38 ppm corresponding to the
deuterium atoms of the cyclopentadienyl group.
F igu r e 1. Molecular diagram of complex OsH2{η5-C5H4-
Si(C6H4)Ph2}(PiPr3) (8). Thermal ellipsoids are shown at
50% probability.
2
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for th e Com p lex
OsH2{η5-C5H4Si(C6H4)P h 2}(P iP r 3) (8)
1
2
The H and H NMR spectra of 9-d 5 also support the
distribution of deuterium atoms shown in eq 7. In the
high-field region, the 1H NMR spectrum contains at
-14.83 ppm a doublet with an H-P coupling constant
of 29.4 Hz. The intensity of this signal with regard to
Os-P
2.290(2)
2.215(7)
2.205(8)
2.315(8)
2.350(8)
2.243(9)
2.106(7)
1.54(8)
Si-C(1)
1.867(8)
1.869(7)
1.887(8)
1.884(7)
1.444(10)
1.410(10)
1.414(9)
1.389(11)
1.383(11)
1.388(10)
Os-C(1)
Os-C(2)
Os-C(3)
Os-C(4)
Os-C(5)
Os-C(6)
Os-H(01)
Os-H(02)
Si-C(7)
Si-C(12)
Si-C(18)
C(6)-C(7)
C(6)-C(11)
C(7)-C(8)
C(8)-C(9)
C(9)-C(10)
C(10)-C(11)
n
the C5D4-CH2 resonance of the Bu group is 0.5. The
2H NMR spectrum shows at -14.78 ppm a doublet with
a D-P coupling constant of 2.6 Hz, corresponding to the
deuteride ligand, and the characteristic AA′BB′ spin
system due to the deuterium atoms of the cyclopenta-
dienyl group, centered at 4.73 ppm.
1.56(7)
P-Os-M(1)a
133.6(3)
107.29(19)
71(3)
Os-C(6)-C(7)
Si-C(1)-C(2)
Si-C(1)-C(5)
Si-C(7)-C(6)
C(1)-Si-C(7)
C(1)-Si-C(12)
C(1)-Si-C(18)
C(7)-Si-C(12)
C(7)-Si-C(18)
C(12)-Si-C(18)
116.1(5)
123.8(5)
126.4(6)
114.8(5)
102.8(3)
111.9(3)
109.1(3)
114.1(3)
111.1(3)
107.8(3)
P-Os-C(6)
P-Os-H(01)
P-Os-H(02)
71(2)
The reactions shown in eqs 6 and 7 can be rationalized
according to Scheme 4 (Nu ) R). The formation of both
8-d 4 and 9-d 5 (eq 7) suggests that on OsH(η5-C5X5)(R)-
(SiPh3)(PiPr3) (X ) H, D; R ) alkyl) intermediates two
competitive spontaneous migrations from the osmium
atom to the cyclopentadienyl group can take place: the
migration of the silyl group, which affords 8-d 4, and the
migration of the alkyl group, which leads to 9-d 5 by a
pathway similar to that described for the formation of
5-7 and 6-d 5.
According to Scheme 3, the silyl migration should give
OsH(X)(η5-C5X4SiPh3)(R)(PiPr3) intermediates, which
should be unstable toward the reductive elimination of
alkane (R-X). Thus, the formation of unsaturated OsH-
(η5-C5X4SiPh3)(PiPr3) species could afford 8 and 8-d 4 by
C-H activation of a phenyl of the silyl group. The
activation of the phenyl instead an isopropyl group of
the phosphine in the unsaturated OsH(η5-C5X4SiPh3)-
(PiPr3) intermediates agrees well with the aryl C-H
activation observed in the complex Os(η5-C5H5)Cl(PPh3)-
(PiPr3)19d and the thermodynamically favored aromatic
C-H activation of tertiary phosphines attached to the
Ru(η6-C6H6) unit.27 In addition, it should be noted the
absence of some deuterium atom at the metallic center
of 8-d 4, which indicates kinetic and/or thermodynamic
preference by the deuteride ligand during the reductive
elimination of alkane from Os(H)(D)(η5-C5D4SiPh3)(R)-
M(1)-Os-C(6)
M(1)-Os-H(01)
M(1)-Os-H(02)
C(6)-Os-H(01)
C(6)-Os-H(02)
H(01)-Os-H(02)
C(6)-C(7)-C(8)
118.9(3)
126(3)
118(3)
72(3)
73(3)
116(4)
120.8(6)
a
M(1) is the midpoint of the C(1)-C(5) Cp carbon atoms.
(PiPr3)2 (2.089(7) Å),25 Os(η5-C5H5){C6H4[C(OH)(Ph)-
CHdCHOC(O)CH3]}(PiPr3) (2.108(11) Å),19b and OsCl-
{NHdC(Ph)C6H4](η5-H2)(PiPr3)2 (2.069(4) Å).26
To rationalize the formation of 8, we have carried out
the reaction of the perdeuterated cyclopentadienyl
complex 2-d 5 with nBuLi. At room temperature, under
the same conditions as those mentioned for the forma-
n
tion of 8, the addition of a hexane solution of BuLi to
2-d 5 leads to a mixture of the deuterated compounds
OsH2[η5-C5D4Si(C6H4)Ph2}(PiPr3) (8-d 4) and Os(H)(D)-
(η5-C5D4 Bu)(SiPh3)(PiPr3) (9-d 5) in a 2:1 molar ratio (eq
n
7). At low temperature, the formation of 9-d 5 is favored.
Thus, when the reaction is carried out at -78 °C, a 2:3
molar ratio is obtained.
The presence of two hydride ligands in 8-d 4 is sup-
2
ported by the 1H and H NMR spectra of this compound.
(25) Esteruelas, M. A.; Lahoz, F. J .; Lo´pez, A. M.; On˜ate, E.; Oro,
L. A. Organometallics 1995, 14, 2496.
(26) Barea, G.; Esteruelas, M. A.; Lledo´s, A.; Lo´pez, A. M.; On˜ate,
E.; Tolosa, J . I. Organometallics 1998, 17, 4065.
(27) Bennett, M. A.; Huang, T.-N.; Latten, J . L. J . Organomet. Chem.
1984, 272, 189.

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 245
Sch em e 4
(PiPr3), in agreement with the higher strength of the
alkyl-D bond in comparison with the alkyl-H bond.28
Complexes 8-d 4 and 9-d 5 do not undergo H/D ex-
change processes between the osmium atom and the
cyclopentadienyl group at rates comparable to their
rates of formation. This suggests that the migration of
X from the dienes η4-C5X5R and η4-C5X5SiPh3 to the
osmium atom, in the intermediates OsH(SiPh3)(η4-
C5X5R)(PiPr3) and Os(H)(R)(η4-C5X5SiPh3)(PiPr3), is an
irreversible step. So, the exclusive formation of 8,
according to the eq 6, suggests that the SiPh3(Os)/
H(C5H5) exchange is kinetically favored with regard to
the R(Os)/H(C5H5) exchange.
The formation of 9-d 5, according to eq 7, proves that
the R(Os)/D(C5D5) exchange with regard to the SiPh3-
(Os)/D(C5D5) exchange is more favored than the R(Os)/
H(C5H5) exchange with regard to the SiPh3(Os)/H(C5H5)
exchange. These exchange processes involve: (i) the
migration of R or SiPh3 from the osmium atom to the
cyclopentadienyl group, (ii) the exo-1,5-X shift within
the resulting η4-C5X5R or η4-C5X5SiPh3 ligands, and (iii)
the migration of X from the diene to the osmium atom.
The steps i and ii should not be affected by the nature
of X, hydrogen, or deuterium, the first of them because
X is not directly involved, and the second one because
the necessary energy to break the C-X bonds should
be compensated with the energy of formation of the C-X
bonds. However, step iii must be highly dependent upon
the nature of X because it involves the breaking of C-X
bonds and the formation of Os-X bonds. According to
the expected primary isotope effect for this step,28 the
substitution of hydrogen by deuterium should produce
an increase of the energy barriers for the migrations of
X from η4-C5X5SiPh3 and η4-C5X5R to the osmium atoms,
similar in both cases, with the corresponding decrease
in the X migration rates. So, the substitution of hydro-
gen by deuterium should not affect the result of the
reaction shown in eq 6, if the rate-determining steps
for the SiPh3(Os)/X(C5X5) and R(Os)/X(C5X5) exchanges
were the same, since the substitution affects in the same
manner the energy barriers of each step of both pro-
cesses. Neither should one expect the formation of 9-d 5,
according to eq 7, if the rate-determining step for the
SiPh3(Os)/X(C5X5) exchange was step i or ii and the rate-
determining step for the R(Os)/X(C5X5) exchange was
step iii, since the SiPh3(Os)/H(C5H5) exchange is kineti-
cally favored with regard to the R(Os)/H(C5H5) ex-
change, and the substitution of hydrogen by deuterium
should give rise to an increase of the energy barrier for
the R(Os)/X(C5X5) exchange without affecting the energy
barrier for the SiPh3(Os)/X(C5X5) exchange. However,
if the rate-determining step for the SiPh3(Os)/X(C5X5)
exchange was step iii and the rate-determining step for
the R(Os)/X(C5X5) exchange was step i or ii, the substi-
tution of the hydrogen by deuterium should lead to an
increase of the energy barrier for the SiPh3(Os)/X(C5X5)
exchange without affecting the energy barrier for the
R(Os)/X(C5X5) exchange, compensating the initial dif-
ference between them. So, the comparison of eqs 6 and
7 suggests that for the SiPh3(Os)/X(C5X5) exchange the
migration of X from the diene of Os(H)(R)(η4-C5X5-
SiPh3)(PiPr3) to the osmium atom is the rate-determin-
ing step of the process, whereas for the R(Os)/X(C5X5)
exchange the migration of R from the osmium atom of
OsH(η5-C5X5)(R)(SiPh3)(PiPr3) to the cyclopentadienyl
group or, alternatively, the exo-1,5-X shift in the result-
ing diene should be the rate-determining step of the
process.
The formation of both 8-d 4 and 9-d 5 by reaction of
2-d 5 with nBuLi suggests that the difference between
the energy barriers for the SiPh3(Os)/X(C5X5) and R(Os)/
X(C5X5) exchanges is not very high. So, if for the R(Os)/
X(C5X5) exchange the rate-determining step was the
1,5-X shift (the highest energy barrier for the process),
the ratio between the exchanges should be affected by
the elimination of R-X from Os(H)(X)(η5-C5X4SiPh3)-
(28) Connors, K. A. Chemical Kinetics. The Study of Reaction Rates
in Solution; VCH Publisher: New York, 1990.

246 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
(R)(PiPr3). This reductive elimination should shift the
equilibria toward the formation of Os(H)(X)(η5-C5X4-
SiPh3)(R)(PiPr3) and, in this way, toward the formation
of the aryl C-H activation product. However, this does
not appear to be the case: the reductive elimination of
R-D is more favored than the reductive elimination of
R-H (note that 8-d 4 does not contain any deuterium
atom at the metallic center) and the alkyl exchange is
favored for X ) D. So, the rate-determining step for the
R(Os)/X(C5X5) exchange appears to be the alkyl migra-
tion (step i), and the reductive elimination of R-X from
Os(H)(X)(η5-C5X4SiPh3)(R)(PiPr3) appears to occur once
the exchanges have taken place. When decreasing the
reaction temperature, the formation of 9-d 5 is slightly
favored with regard to 8-d 4 (3:2 molar ratio), at -78
°C. This suggests that the R(Os)/D(C5D5) exchange is
slightly favored with regard to the SiPh3(Os)/D(C5D5)
exchange, from a kinetic point of view, and that the
energy barrier for the migration of the silyl group from
the osmium atom of OsH(η5-C5D5)(nBu)(SiPh3)(PiPr3) to
the cyclopentadienyl ligand is lower than that for the
nBu migration.
As expected from the fact that the rate-determining
step for the R(Os)/X(C5X5) exchange is the migration of
the alkyl group to the osmium atom (step i), the molar
ratio between the exchanges is also affected by the
nature of the alkyl group. Thus, we have also observed
that the reaction of 2 with sec-butyllithium, in contrast
to that shown in eq 6, leads to a mixture of 8 and OsH2-
(η5-C5H4secBu)(SiPh3)(PiPr3) (10) in a 4:1 molar ratio (eq
8). The formation of 10 can be rationalized on the basis
of the steric hyndrance of the sec-butyl group, which
favors the migration of the alkyl group from the osmium
atom to the cyclopentadienyl ligand.
The reactions shown in eqs 1-8 take place because the
OsH(η5-C5H5)(Nu)(EPh3)(PiPr3) intermediates are stable
toward the reductive elimination of Nu-H and/or the
formation of the substutituted cyclopentadienyl deriva-
tives is faster than the loss of Nu-H. In contrast to the
nucleophile previously studied, the enolate CH3C(O)CH2-
Li does not afford substituted cyclopentadienyl com-
pounds. Thus, the reaction of 2 with this nucleophile
gives OsH(η5-C5H5)(SiPh2C6H4)(PiPr3) (11) and acetone
(eq 9).
The formation of 11 probably involves the initial
replacement of the chlorine ligand by the enolate,
followed by the reductive elimination of acetone to give
an unsaturated Os(η5-C5H5)(SiPh3)(PiPr3) intermediate.
The intramolecular C-H activation of a phenyl group
of the silyl of this intermediate should afford 11. The
C-H activation of the phenyl group instead an isopropyl
group of the phosphine is in agreement with the
previously mentioned arene preference in the Os(η5-
C5H5)(LPh)(PiPr3) fragments.19d
Complex 11 was isolated as a white solid in 65% yield
and characterized by MS, elemental analysis, and IR
1
and H, 13C{1H}, and 31P{1H} NMR spectroscopies. In
1
the H NMR spectrum, the most noticeable resonance
is a doublet at -13.71 ppm, with an H-P coupling
constant of 29.7 Hz, corresponding to the hydride ligand.
In the 13C{1H} NMR spectrum, the resonance due to
the metalated carbon atom is observed at 165.2 ppm as
a singlet. The 31P{1H} NMR spectrum contains at 21.8
ppm a singlet, which under off-resonance conditions is
split into a doublet by spin coupling with a hydride
ligand.
5. Rea ction s of OsH(η5-C5H5)Cl(GeP h 3)(P iP r 3)
w ith LiNR2 (R ) Et, a llyl): NR2(Os)/H(C5H5) Ex-
ch a n ge. Treatment of tetrahydrofuran solutions of 1
with LiNR2 (R ) Et, allyl) at room temperature leads
to OsH2(η5-C5H4NR2)(GePh3)(PiPr3) (R ) Et (12), allyl
(13)), where the substituent of the cyclopentadienyl
group contains a nitrogen atom (eq 10). The formation
of these derivatives can be rationalized as the initial
replacement of the chlorine ligand of 1 by the amide
followed by an NR2(Os)/H(C5H5) exchange.
1
The H NMR spectrum of 10 agrees well with that of
7. In accordance with the asymmetry of the alkyl
substituent of the cyclopentadienyl ligand, the spectrum
contains two Pr-methyl chemical shifts and two hy-
i
dride resonances at -14.72 and -14.91 ppm, with H-P
and H-H coupling constants of 27.6 and 3.9 Hz, in both
cases. Furthermore, the spectrum shows a complex
resonance between 4.90 and 4.30 ppm, corresponding
to the cyclopentadienyl protons, and two multiplets
at 1.40 (CH) and 1.15 (CH2) ppm, a doublet at 1.05
(J (HH) ) 6.6 Hz, CH3) ppm, and a triplet at 0.69
(J (HH) ) 7.2 Hz, CH3) ppm, due to the sec-butyl group.
The presence of the sec-butyl substituent at the cyclo-
pentadienyl group is supported by the APT 13C{1H}
NMR spectrum, which shows at 32.5 ppm an up-singlet,
corresponding to the CH carbon atom. The 31P{1H}
NMR spectrum contains a singlet at 40.6 ppm.
Complexes 12 and 13 were isolated as white solids
in 56% (12) and 53% (13) yield and characterized by MS,
elemental analysis, and IR and 1H, 13C{1H}, and 31P-
{1H} NMR spectroscopies. Furthermore, complex 13 was
characterized by X-ray diffraction analysis. A view of
its molecular geometry is shown in Figure 2. Selected
bond distances and angles are listed in Table 2. The
4. Rea ction of OsH(η5-C5H5)Cl(SiP h 3)(P iP r 3) w ith
CH3C(O)CH2Li: C-H Activation of a P h en yl Gr ou p.

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 247
Ta ble 3. Cr ysta l Da ta a n d Da ta Collection a n d
Refin em en t for
OsH2{η5-C5H4Si(C6H4)P h 2}(P iP r 3) (8) a n d
OsH2{η5-C5H4N(CH2CHdCH2)2}(GeP h 3)(P iP r 3) (13)
8
13
Crystal Data
32H41SiPOs
674.91
colorless block
triclinic, P1h
formula
molecular wt
color and habit
symmetry,
space group
a, Å
C
C38H52NPGeOs
816.17
colorless, prismatic
monoclinic, P21/n
10.677(1)
11.171(2)
13.241(2)
85.53(1)
72.32(1)
80.04(1)
1481.5(4)
2
12.345(2)
20.975(2)
13.932(2)
b, Å
c, Å
R, deg
â, deg
91.07(2)
γ, deg
V, Å3
3606.9(9)
4
1.504
Z
D
calc, g cm-3
1.513
data collection
and refinement
diffractometer
F igu r e 2. Molecular diagram of complex OsH2{η5-C5H4-
N(CH2CHdCH2)2}(GePh3)(PiPr3) (13). Thermal ellipsoids
are shown at 50% probability.
Brucker-Siemens P4 Bruker Siemens-
STOE AED-2
0.71073
λ(Mo KR), Å
monochromator
µ, mm-1
scan type
2θ range, deg
temp, K
graphite oriented
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for th e Com p lex
4.42
4.42
ω/2θ
5° e 2θ e 50°
200.0(2)
ω/2θ
5°e 2θ e 50°
298.0(2)
OsH2{η5-C5H4N(CH2CHdCH2)2}(GeP h 3)(P iP r 3) (13).
Os-Ge
2.4596(7)
2.2988(13)
2.354(5)
2.280(5)
2.235(5)
2.221(5)
2.241(6)
1.30(5)
N-C(1)
1.448(8)
1.419(8)
1.383(8)
1.493(10)
1.297(11)
1.461(11)
1.283(15)
1.432(8)
1.428(9)
1.414(8)
1.400(9)
no. of data collected
6101 (h: -12, 1;
k: -13, 13; l:
-15, 15)
5185 (merging R
factor 0.0484)
10 617 (h: -14, 14;
k: 0, 24; l:
-16, 7)
6330 (merging R
factor 0.0475)
392
Os-P
N-C(4)
Os-C(34)
Os-C(35)
Os-C(36)
Os-C(37)
Os-C(38)
Os-H(01)
Os-H(02)
N-C(34)
C(1)-C(2)
C(2)-C(3)
C(4)-C(5)
C(5)-C(6)
C(34)-C(35)
C(35)-C(36)
C(36)-C(37)
C(37)-C(38)
no. of unique data
no. of params refined 318
a
R1 [F2 > 2σ(F2)]
0.0439
0.0317
b
wR2 [all data]
0.1240
1.022
0.0875
0.994
1.59(5)
Sc [all data]
R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. bwR2(F2) ) {∑[w(Fo - Fc2)2]/
a
2
∑[w(Fo2)2]}1/2. Goof ) S ) {∑[w(Fo - Fc2)2]/(n - p)}1/2, where n
is the number of reflections, and p is the number of refined
parameters.
c
2
Ge-Os-P
108.89(4)
122.9(2)
66(2)
68.0(18)
128.3(2)
88.4(18)
82.7(15)
111(2)
N-C(1)-C(2)
N-C(4)-C(5)
N-C(34)-C(35)
N-C(34)-C(38)
C(1)-N-C(4)
C(1)-N-C(34)
C(4)-N-C(34)
C(1)-C(2)-C(3)
C(4)-C(5)-C(6)
113.6(6)
115.7(7)
125.4(5)
127.4(5)
120.0(6)
119.0(5)
119.9(5)
127.3(9)
126.1(9)
Ge-Os-M(1)a
Ge-Os-H(01)
Ge-Os-H(02)
P-Os-M(1)
cyclopentadienyl amino complexes.29 The delocalization
produces the shortening of the N-C distances (1.383-
(8), 1.419(8), and 1.448(8) Å), which are shorter than
those expected for N-C(sp2) (about 1.44 Å) and N-C(sp3)
(about 1.50 Å) single bonds.30
P-Os-H(01)
P-Os-H(02)
M(1)-Os-H(01)
M(1)-Os-H(02)
H(01)-Os-H(02)
115(2)
127(3)
In agreement with the structure shown in Figure 2,
the 1H NMR spectra of 12 and 13 show AA′BB′ spin
systems between 4.5 and 4.0 ppm, for the hydrogen
a
M(1) is the midpoint of the C(1)-C(5) Cp carbon atoms.
distribution of ligands around the osmium atom can be
described as a piano stool geometry, with the cyclopen-
tadienyl ligand occupying the three-membered face,
while the four monodentate ligands lie in the other face.
The bulky ligands, triisopropylphosphine and triphen-
ylgermyl, are mutually transoid disposed, with a Ge-
Os-P angle of 108.89(4)°. This stereochemistry is
similar to that found in the diphenylsilyl derivative
OsH(η5-C5H5)Cl(SiHPh2)(PiPr3) and appears to be ther-
modynamically favored. The basis of this preference
isprobably steric and involves minimizing interaction
between the ER3 ligand and the isopropyl groups of the
phophine.20 The Os-Ge distance is 2.4596(7) Å.
i
atoms of the cyclopentadienyl group, only one Pr-
methyl chemical shift, and in the high-field region
doublets at -14.10 (12) and -14.12 (13) ppm with H-P
coupling constants of about 29 Hz, corresponding to the
equivalent hydride ligands. The carbon atoms of the
cyclopentadienyl rings display three signals, at about
132 (CN), 68 and 63 (C-H) ppm, in the 13C{1H} NMR
spectra. The 31P{1H} NMR spectra contain singlets at
40.2 (12) and 39.8 (13) ppm, which under off-resonance
(29) (a) Stahl, K.-P.; Boche, G.; Massa, W. J . Organomet. Chem.
1984, 277, 113. (b) Morrow, J . R.; Templeton, J . L.; Bandy, J . A.;
Bannister, C.; Prout, C. K. Inorg. Chem. 1986, 25, 1923. (c) Brun, P.;
Vierling, P.; Riess, J . G.; Le Borgne, G. Organometallics 1987, 6, 1032.
(d) Luttikhedde, H. J . G.; Leino, R. P.; Wile´n, C.-E.; Na¨sman, J . H.;
Ahlgre´n, M. J .; Pakkanen, T. A. Organometallics 1996, 15, 3092. (e)
Barsties, E.; Schaible, S.; Prosenc, M.-H.; Rief, U.; Ro¨ll, W.; Weyand,
O.; Dorer, B.; Brintzinger, H.-H. J . Organomet. Chem. 1996, 520, 63.
(f) Knu¨ppel, S.; Faure´, J .-L.; Erker, G.; Kehr, G.; Nissinen, M.; Fro¨hlich,
R. Organometallics 2000, 19, 1262.
The amino group of the substituted cyclopentadienyl
ligand is planar with angles around the nitrogen atom
of about 120°. This indicates that the nitrogen lone pair
is largely delocalized into the aromatic ring and allyl
systems, as has been previously observed in other
(30) Bernad, D. J .; Esteruelas, M. A.; Lo´pez, A. M.; Modrego, J .;
Puerta, M. C.; Valerga, P. Organometallics 1999, 18, 4995.

248 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
conditions are split into triplets by spin coupling with
the hydride ligands.
The 31P{1H} NMR spectra show singlets at about 39
ppm, which under off-resonance conditions are split into
triplets.
6. Reaction s of OsH(η5-C5H5)Cl(SiP h 3)(P iP r 3) with
LiNR2 (R ) Et, a llyl): NR2(Os)/H(C5H5) Exch a n ge
ver su s SiP h 3(Os)/H(C5H5) Exch a n ge. Treatment at
room temperature of tetrahydrofuran solutions of 2 with
LiNR2 (R ) Et, allyl) in contrast to the reactions shown
in eq 10 leads to mixtures of 8 and the cyclopentadienyl
amino complexes OsH2(η5-C5H4NR2)(SiPh3)(PiPr3) (R )
Et (14), allyl (15)). The molar ratios of the reaction
products depend on the substituents of the amide (eq
11).
7. R ea ct ion s of OsH (η5-C5H 5)Cl(E P h 3)(P iP r 3)
(E ) Ge, Si) w ith LiP P h 2: P P h 2(Os)/H(C5H5) Ex-
ch a n ge. Treatment of tetrahydrofuran solutions of 1
and 2 with LiPPh2 at room temperature leads to the
cyclopentadienyl phosphine derivatives OsH2(η5-C5H4-
PPh2)(EPh3)(PiPr3) (R ) Ge (16), Si (17)), according to
eq 12. The formation of these derivatives can be
rationalized as the initial replacement of the chlorine
ligand of the starting compounds by the phosphide
group, followed by a PPh2(Os)/H(C5H5) exchange.
Complexes 16 and 17 were isolated as white solids
in about 60% yield. In agreement with the related
1
compounds previously described, the H NMR spectra
of 16 and 17 show AA′BB′ spin systems between 4.8 and
4.4 ppm for the hydrogen atoms of the cyclopentadienyl
i
group, only one Pr-methyl chemical shift, and in the
high-field region double doublets at -14.40 (16) and
-14.65 (17) ppm, with H-P coupling constants of about
29 and 3 Hz, corresponding to the hydride ligands.
The presence of a cyclopentadienyl-P bond in the
complexes is strongly supported by the 13C{1H} NMR
spectra, which show at 93.4 (16) and 91.8 (17) doublets,
with C-P coupling constants of about 18 Hz, corre-
sponding to the C-P carbon atoms of the cyclopenta-
dienyl groups. The 31P{1H} NMR spectra also support
the structures shown in eq 12. Thus, they contain two
singlets at about 39 (PiPr3) and -18 (C5H4PPh2) ppm.
Under off-resonance conditions, the triisopropylphos-
phine resonances are split into triplets, whereas the
C5H4PPh2 resonances remain unchanged.
The reactions shown in eq 11 can be rationalized
according to Scheme 4. That is, the migration of the
amide from the osmium atom to the cyclopentadienyl
ligand, to give 14 or 15, competes with the silyl
migration to afford OsH2(η5-C5H4SiPh3)(NR2)(PiPr3) in-
termediates, which evolve into 8 by reductive elimina-
tion of amine and subsequent aryl C-H activation.
To establish the preference of the migration, we have
carried out the reaction of 2 with LiNEt2 at -78 °C. At
this temperature, complex 14 is the only detected
reaction product. Since the H(Os)/X(C5X4Nu) and H(Os)/
X(C5X4SiPh3) exchanges do not appear to occur in these
systems, the above-mentioned suggests that the NEt2-
(Os)/H(C5H5) exchange is slightly favored with regard
to the SiPh3(Os)/H(C5H5) exchange, from a kinetic point
of view.
8. Gen er a liza tion of th e Rea ctivity of OsH(η5-
C5H5)Cl(EP h 3)(P iP r 3) (E ) Ge, Si) tow a r d LiNu ,
a n d Con clu sion . Scheme 5 sumarizes the behavior of
1 and 2 in the presence of LiNu (Nu ) R, NR2, PPh2)
reagents. Treatment of tetrahydrofuran solutions of
both species with these reagents produces the replace-
ment of the chlorine ligand of 1 and 2 by the Nu group
to afford OsH(η5-C5H5)(EPh3)(Nu)(PiPr3) intermediates,
which are unstable and evolve in three different man-
ners depending on the nature of E and the Nu group.
(a ) EP h 3(Os)/H(C5H5) Exch a n ge. This process af-
fords OsH2(η5-C5H4EPh3)(Nu)(PiPr3) derivatives, which
have been isolated when the atom E is Ge and Si and
the Nu group is CH2CN (eq 1).
(b) Nu (Os)/H(C5H5) Exch a n ge. This behavior is
observed when the atom E is Ge and the Nu group is
alkyl, amide, and phosphide and when the atom E is Si
and the Nu group is phosphide. In this case, the
dihydride germyl OsH2(η5-C5H4Nu)(GePh3)(PiPr3)
(Nu ) CH3, nBu, secBu, NEt2, N(allyl)2, PPh2) and
dihydride silyl OsH2(η5-C5H4PPh2)(SiPh3)(PiPr3) deriva-
tives are formed (eqs 4, 10, and 12).
The comparison of eqs 10 and 11 suggests that in
OsH(η5-C5H5)(EPh3)(Nu)(PiPr3) (E ) Si, Ge) intermedi-
ates the migration of the SiPh3 group from the osmium
atom to the cyclopentadienyl ligand is favored with
regard to the migration of the GePh3 group not only
when Nu is alkyl (eqs 4 and 6) but also when Nu is
amide. In this context, it should be mentioned that
spectroscopic studies on OsH(η5-C5H5)Cl(EPh3)(PiPr3)
(E ) Ge, Si) complexes show that Os-Ge bonds are
significantly stronger than the Os-Si bonds.20
The spectroscopic data of 14 and 15 agree with those
1
of 12 and 13. The H NMR spectra show AA′BB′ spin
systems between 4.5 and 4.0 ppm for the hydrogen
i
atoms of the cyclopentadienyl group, only one Pr-
methyl chemical shift, and in the high-field region
doublets at -14.45 ppm (both compounds) with H-P
coupling constants of about 28 Hz, corresponding to the
hydride ligands. The 13C{1H} NMR spectra contain
three resonances for the carbon atoms of the cyclopen-
tadienyl rings, at about 134 (CN), 71 and 63 (CH) ppm.
(c) Red u ctive Elim in a tion of H-Nu . This occurs
in the reaction of 2 with LiCH2C(O)CH3. The loss of

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 249
Sch em e 5
acetone from OsH(η5-C5H5)(SiPh3){CH2C(O)CH3}(PiPr3)
affords the Os(η5-C5H5)(SiPh3)(PiPr3) intermediate, which
has the same behavior as the previously reported Os-
(η5-C5H5)(PiPr3)(LPh) systems19d and evolves by aryl
only detected organometallic reaction product, suggests
that NR2(Os)/H(C5H5) exchange is slightly favored with
regard to the SiPh3(Os)/H(C5H5) exchange, from a
kinetic point of view.
The reaction of OsH(η5-C5H5)Cl(SiPh3)(PiPr3) with
C-H activation into OsH(η5-C5H5)(SiPh2C6H4)(PiPr3)
(eq 9).
LiR (R ) CH3, nBu) at room temperature leads to OsH2-
Similarly to the complex OsH2(η5-C5H5)(SnnBu3)-
(PiPr3) previously reported,20 the derivatives OsH2(η5-
{η5-C5H4Si(C6H4)Ph2}(PiPr3) as the only organometallic
reaction product (eq 6). At first glance, this could
suggest that the OsH(η5-C5H5)(R)(SiPh3)(PiPr3) (R )
CH3, nBu) intermediates only undergo SiPh3(Os)/
H(C5H5) exchange. However, the reaction of OsH(η5-
n
C5H4Nu)(EPh3)(PiPr3) (E ) Ge, Nu ) CH3, Bu, secBu,
NEt2, N(allyl)2, PPh2; E ) Si, Nu ) PPh2) are stable
toward the reductive elimination of HEPh3. However,
the stability of the OsH2(η5-C5H4EPh3)(Nu)(PiPr3) spe-
cies depends on the nature of the Nu group. Thus, the
reactions shown in eqs 8 and 11, where mixtures of
n
C5D5)Cl(SiPh3)(PiPr3) with BuLi, which affords a mix-
ture of OsH2{η5-C5D4Si(C6H4)Ph2}(PiPr3) and Os(H)-
(D)(η5-C5D4nBu)(SiPh3)(PiPr3) (eq 7), indicates that the
above-mentioned OsH(η5-C5H5)(R)(SiPh3)(PiPr3) inter-
mediates also undergo both SiPh3(Os)/H(C5H5) and
R(Os)/H(C5H5) exchanges in a competitive manner.
OsH2{η5-C5H4Si(C6H4)Ph2}(PiPr3) and OsH2(η5-C5H4-
Nu)(SiPh3)(PiPr3) (Nu ) secBu, NEt2, N(allyl)2) are
obtained, suggest the following:
(i) For E ) Si and Nu ) secBu, NEt2, and N(allyl)2,
the OsH(η5-C5H5)(EPh3)(Nu)(PiPr3) intermediates un-
dergo both EPh3(Os)/H(C5H5) and Nu(Os)/H(C5H5) ex-
changes in a competitive manner.
The comparison of the products from the reactions
shown in eqs 1, 2, and 4-12 indicates that the trend of
the ligands H, Nu, and EPh3 for exchanging their
positions with the hydrogen atoms of the cyclopenta-
dienyl group in the OsH(η5-C5H5)(EPh3)(Nu)(PiPr3) spe-
(ii) The species OsH2(η5-C5H4SiPh3)(Nu)(PiPr3) (Nu )
secBu, NEt2, N(allyl)2) resulting from the SiPh3(Os)/
H(C5H5) exchange, in contrast to the complexes OsH2-
(η5-C5H4EPh3)(CH2CN)(PiPr3) (E ) Ge, Si), are unstable
toward the reductive elimination of H-Nu. As a result,
the metallic center of the formed unsaturated interme-
diate OsH(η5-C5H4SiPh3)(PiPr3) is capable of a C-H
activation reaction on one of the phenyl groups of the
cies decreases in the sequence PPh2 > N(allyl)2
>
NEt2 > SiPh3 > secBu > CH3, nBu > GePh3 > H, D, CH2-
CN, CH2C(O)CH3.
In conclusion, the reactions of OsH(η5-C5H5)Cl(EPh3)-
(PiPr3) (E ) Ge, Si) with LiNu reagents can give rise to
four different types of compounds: OsH2(η5-C5H4EPh3)-
SiPh3 fragment, to give OsH2{η5-C5H4Si(C6H4)Ph2}-
(PiPr3).
(Nu)(PiPr3), OsH2(η5-C5H4Nu)(EPh3)(PiPr3), OsH2{η5-
C5H4Si(C6H4)Ph2}(PiPr3), and OsH2(η5-C5H5)(SiPh2C6H4)-
(PiPr3). The formation of these derivatives can be
rationalized on the basis of the trend of the EPh3 and
Nu ligands of OsH(η5-C5H5)(EPh3)(Nu)(PiPr3) for ex-
Although in the OsH(η5-C5H5)(NR2)(SiPh3)(PiPr3) in-
termediates both exchanges occur, the reaction of
OsH(η5-C5H5)Cl(SiPh3)(PiPr3) with LiNEt2 at -78 °C,
which gives OsH2(η5-C5H4NEt2)(SiPh3)(PiPr3) as the

250 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
1
its analogue 4, but using 2-d 5 as starting material. H NMR
changing their positions with the hydrogen atoms of the
cyclopentadienyl group and on the basis of the stability
of these species and OsH2(η5-C5H4EPh3)(Nu)(PiPr3)
toward the reductive elimination of H-Nu.
(300 MHz, C6D6, 293 K): δ 8.00-7.00 (15 H, -Ph); 1.88 (s, 2
H, -CH2-); 1.23 (m, 3 H, PCH); 0.83 (dd, 18 H, PCHCH3,
2J HP ) 13.2 Hz, J HH ) 6.9 Hz); -14.82 (d, 1 H, Os-H, J HP
)
2
2
27.0 Hz). 2H NMR (46.1 MHz, C6H6, 293 K): δ 4.51-4.17
(4 D, η5-C5D4-, AA′BB′ system), -14.89 (br s, 1 D, Os-D).
31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 41.0 (s).
Exp er im en ta l Section
R ea ct ion of OsH 2(η5-C5H4SiP h 3)(CH2CN)(P iP r 3) w it h
CD3OD. A suspension of OsH2(η5-C5H4SiPh3)(CH2CN)(PiPr3)
in CD3OD was left to stir for 3 days. The resulting suspension
was vacuum-dried, leading to a white solid (4-d 2) which
showed 37% deuteration on the -CH2- unit.
All reactions were carried out with rigorous exclusion of air
using Schlenk-tube techniques. Solvents were dried by the
usual procedures and distilled under argon prior to use. The
starting materials OsH(η5-C5H5)Cl(GePh3)(PiPr3) (1) and OsH-
(η5-C5H5)Cl(SiPh3)(PiPr3) (2) were prepared by the published
methods.20 The starting materials OsH(η5-C5D5)Cl(GePh3)-
(PiPr3) (1-d 5) and OsH(η5-C5D5)Cl(SiPh3)(PiPr3) (2-d 5) were
prepared by using procedures similar to those of the non-
deuterated counterparts. Their precursor Os(η5-C5D5)Cl(PiPr3)2
was prepared in the same way described for Os(η5-C5H5)Cl-
(PiPr3)2, but using TlC5D5.18 TlC5D5 was prepared as previously
described.31
P r ep a r a tion of OsH2(η5-C5H4CH3)(GeP h 3)(P iP r 3) (5). To
a solution of OsH(η5-C5H5)Cl(GePh3)(PiPr3) (167.5 mg, 0.22
mmol) in 10 mL of THF was added methyllithium (0.2 mL).
The mixture was left to stir for 20 min, and methanol (1 mL)
was added. After 1 min of stirring, the solution was vacuum-
dried, and the resulting sticky residue was then washed with
methanol (2 × 3 mL), leading to a white solid. Yield: 81 mg
(49%). Anal. Calcd for C33H45GeOsP: C, 53.88; H, 6.18.
Found: C, 53.53; H, 6.03. IR (Nujol, cm-1): ν(Os-H) 2093 (m).
1H NMR (300 MHz, C6D6, 293 K): δ 8.10-7.10 (15 H, -Ph);
4.60-4.40 (4 H, η5-C5H4-, AA′BB′ system); 1.85 (s, 3 H, η5-
C5H4-CH3); 1.36 (m, 3 H, PCH); 0.83 (dd, 18 H, PCHCH3,
In the NMR spectra, chemical shifts are expressed in ppm
downfield from Me4Si (1H and 13C) and 85% H3PO4 (31P).
Coupling constants, J , are given in hertz.
P r ep a r a tion of OsH2(η5-C5H4GeP h 3)(CH2CN)(P iP r 3) (3).
To a solution of OsH(η5-C5H5)Cl(GePh3)(PiPr3) (211.2 mg, 0.28
mmol) in 10 mL of THF was first added acetonitrile (1 mL)
and then n-buthyllithium (0.3 mL). The mixture was left to
stir for 30 min, and methanol (1 mL) was added. After 1 min
of stirring, the solution was vacuum-dried, and the resulting
sticky residue was washed with methanol (2 × 4 mL), leading
3
2
3J HP ) 13.5 Hz, J HH ) 6.9 Hz); -14.45 (d, 2 H, Os-H, J HP
)
29.1 Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ
149.8 (-, s, Cipso SiPh3); 136.5, 127.6 (+, s, Cortho, C meta
GePh3); 127.4 (+, s, Cpara GePh3); 100.2 (-, s, quaternary C
in η5-C5H4-CH3); 81.8, 75.8 (+, s, tertiary C’s in η5-C5H4-CH3);
1
29.6 (+, d, PCH, J CP ) 29.4 Hz); 19.8 (+, s, PCH-CH3); 14.4
to a white solid. Yield: 115 mg (55%). Anal. Calcd for C34H44
-
(+, s, -CH3). 31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 42.3
(s, t in off-resonance). MS (FAB+): m/z ) 657 (M+ - Ph).
P r ep a r a tion of OsH2(η5-C5H4CH2CH2CH2CH3)(GeP h 3)-
(P iP r 3) (6). To a solution of OsH(η5-C5H5)Cl(GePh3)(PiPr3) (179
mg, 0.24 mmol) in 10 mL of THF was added n-buthyllithium
(0.5 mL), and the mixture was left to react for 1 h. Methanol
(1 mL) was added, the mixture was stirred for 1 min and then
vacuum-dried. The resulting residue was washed with metha-
nol (2 × 4 mL), leading to a white solid. Yield: 108 mg (59%).
Anal. Calcd for C36H51GeOsP: C, 55.61; H, 6.61. Found: C,
GeNOsP: C, 53.70; H, 5.83; N, 1.84. Found: C, 54.02; H, 6.29;
N, 1.82. IR (Nujol, cm-1): ν(CtN) 2257 (m); v(Os-H) 2135
1
(m), 2088 (m), 2069 (m). H NMR (300 MHz, C6D6, 293 K): δ
8.00-7.00 (15 H, -Ph); 4.70-4.40 (4 H, η5-C5H4-, AA′BB′
system); 2.10 (s, 2 H, -CH2-); 1.30 (m, 3 H, PCH); 0.83 (dd,
3
3
18 H, PCHCH3, J HP ) 13.5 Hz, J HH ) 7.2 Hz); -14.49 (d, 2
H, Os-H, J HP ) 28.8 Hz). 13C{1H} NMR (75.4 MHz, C6D6,
2
293 K, plus APT): δ 149.0 (-, s, Cipso Ph); 136.3, 127.9 (+, s,
Cortho, Cmeta Ph); 127.8 (+, s, Cpara Ph); 118.3 (-, s, -CN);
91.3 (-, s, quaternary C in η5-C5H4-Ge); 80.1, 78.5 (+, s,
tertiary C’s in η5-C5H4-Ge); 29.2 (+, d, PCH, 1J CP ) 32.3 Hz);
19.8 (+, s, PCH-CH3); 16.5 (-, s, -CH2-). 31P{1H} NMR
(121.4 MHz, C6D6, 293 K): δ 41.6 (s, t in off-resonance). MS
(FAB+): m/z ) 761 (M+), 684 (M+ - Ph).
1
55.19; H, 6.41. IR (Nujol, cm-1): ν(Os-H) 2118 (m). H NMR
(300 MHz, C6D6, 293 K): δ 8.10-7.10 (15 H, -Ph); 4.60-4.40
(4 H, η5-C5H4-, AA′BB′ system); 2.09 (t, 2 H, η5-C5H4-CH2-,
3J HH ) 7.8 Hz); 1.37 (m, 3 H, PCH); 1.30 - 1.10 (m, 4 H,
3
-CH2-CH2-); 0.85 (dd, 18 H, PCHCH3, J HP ) 13.5 Hz,
P r ep a r a tion of OsH2(η5-C5H4SiP h 3)(CH2CN)(P iP r 3) (4).
To a solution of OsH(η5-C5H5)Cl(SiPh3)(PiPr3) (167.6 mg, 0.24
mmol) in 10 mL of THF was first added acetonitrile (1 mL)
and then n-buthyllithium (0.5 mL). The mixture was left to
stir for 1 h, and methanol (1 mL) was added. After 1 min of
stirring, the resulting solution was vacuum-dried, and the
sticky residue was washed with methanol (2 × 4 mL), leading
3
3J HH ) 7.2 Hz); 0.79 (t, 3 H, -CH3, J HH ) 7.2 Hz); -14.52 (d,
2
2 H, Os-H, J HP ) 29.4 Hz). 13C{1H} NMR (75.4 MHz, C6D6,
293 K, plus APT): δ 149.5 (-, s, Cipso Ph); 136.1, 127.2 (+, s,
Cortho, Cmeta Ph); 127.0 (+, s, Cpara Ph); 105.4 (-, s,
quaternary C in η5-C5H4-CH2-); 80.5, 75.6 (+, s, tertiary C’s
in η5-C5H4-CH2-); 35.3 (-, s, η5-C5H4-CH2-CH2-CH2-); 29.4
1
(+, d, PCH, J CP ) 29.4 Hz); 28.6, 22.6 (-, s, η5-C5H4-CH2-
to a white solid. Yield: 98 mg (58%). Anal. Calcd for C34H44
-
CH2-CH2-); 19.5 (+, s, PCH-CH3); 14.0 (+, s, -CH3). 31P{1H}
NMR (121.4 MHz, C6D6, 293 K): δ 42.0 (s, t in off-resonance).
MS (FAB+): m/z ) 778 (M+), 701 (M+ - Ph).
NOsPSi: C, 57.02; H, 6.21; N, 1.96. Found: C, 56.62; H, 5.87;
N, 1.86. IR (Nujol, cm-1): ν(CtN) 2256 (m); ν(Os-H) 2117 (m),
1
2104 (m). H NMR (300 MHz, C6D6, 293 K): δ 8.00-7.00 (15
P r ep a r a tion of Os(H)(D)(η5-C5D4CH2CH2CH2CH3)(Ge-
P h 3)(P iP r 3) (6-d 5). This product was synthesized by the same
method as its analogue 6, but using 1-d 5 as starting material.
1H NMR (300 MHz, C6D6, 293 K): δ 8.10-7.10 (15 H, -Ph);
H, -Ph); 4.80-4.30 (4 H, η5-C5H4-, AA′BB′ system); 1.87 (s,
2 H, -CH2-); 1.23 (m, 3 H, PCH); 0.83 (dd, 18 H, PCHCH3,
2
2
2J HP ) 13.2 Hz, J HH ) 6.9 Hz); -14.80 (d, 2 H, Os-H, J HP
)
27.0 Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT):
δ 147.7 (-, s, Cipso Ph); 137.3, 127.5 (+, s, Cortho, Cmeta Ph);
128.0 (+, s, Cpara Ph); 118.3 (-, s, -CN); 92.9 (-, s,
quaternary C in η5-C5H4-Si); 81.6, 78.2 (+, s, tertiary C’s in
3
2.10 (t, 2 H, η5-C5D4-CH2-, J HH ) 7.8 Hz); 1.37 (m, 3 H,
PCH); 1.30-1.10 (m, 4 H, -CH2-CH2-); 0.85 (dd, 18 H,
3
3
PCHCH3, J HP ) 13.5 Hz, J HH ) 7.2 Hz); 0.79 (t, 3 H, -CH3,
3J HH ) 7.2 Hz); -14.54 (d, 1 H, Os-H, J HP ) 29.4 Hz). 2H
2
η5-C5H4-Si); 28.1 (+, d, PCH, J CP ) 29.0 Hz); 19.6 (+, s,
1
NMR (46.1 MHz, C6H6, 293 K): δ 4.61 (s, 4 D, η5-C5D4-);
-14.33 (br s, 1 D, Os-D). 31P{1H} NMR (121.4 MHz, C6D6,
293 K): δ 42.2 (s).
PCH-CH3); 15.8 (-, s, -CH2-). 31P{1H} NMR (121.4
MHz, C6D6, 293 K): δ 40.9 (s, t in off-resonance). MS (FAB+):
m/z ) 717 (M+), 640 (M+ - Ph).
P r epar ation of OsH2{η5-C5H4CH(CH3)CH2CH3}(GeP h 3)-
(P iP r 3) (7). To a solution of OsH(η5-C5H5)Cl(GePh3)(PiPr3)
(250.1 mg, 0.33 mmol) in 10 mL of THF was added sec-
buthyllithium (1 mL), and the mixture was left to react for 20
min. Methanol (1 mL) was added, the mixture was stirred for
P r ep a r a tion of Os(H)(D)(η5-C5D4SiP h 3)(CH2CN)(P iP r 3)
(4-d 5). This product was synthesized by the same method as
(31) Anderson, G. K.; Cross, R. J .; Phillips, I. G. J . Chem. Soc., Chem.
Commun. 1978, 709.

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 251
1 min and then vacuum-dried. The subsequent residue was
washed with methanol (2 × 4 mL), finally leading to a white
solid. Yield: 157 mg (61%). Anal. Calcd for C36H51GeOsP: C,
55.60; H, 6.62. Found: C, 56.00; H, 6.35. IR (Nujol, cm-1):
ν(Os-H) 2100 (m). 1H NMR (300 MHz, C6D6, 293 K): δ 8.00-
7.10 (15 H, -Ph); 4.80-4.40 (4 H, η5-C5H4-, ABCD system);
1.62 (m, 1 H, η5-C5H4-CH-); 1.40 (m, 3 H, PCH); 1.19 (m, 2
H, η5-C5H4-CH-CH2-); 1.08 (d, 3 H, η5-C5H4-CH-CH3,
20 min. Methanol (1 mL) was added, and the mixture was
stirred for 1 min and then vacuum-dried. The subsequent
residue was washed with methanol (2 × 5 mL), leading to a
white solid which was a (1:4) mixture of 10 and 8. IR (Nujol,
cm-1): ν(Os-H) hidden by resonances of 8. 1H NMR (300 MHz,
C6D6, 293 K): δ 8.00-6.90 (15 H, -Ph); 4.90-4.30 (4 H, η5-
C5H4-, ABCD system); 1.40 (m, 1 H, η5-C5H4-CH-); 1.32 (m,
3 H, PCH); 1.15 (m, 2 H, η5-C5H4-CH-CH2-); 1.05 (d, 3 H,
3
3J HH ) 6.9 Hz); 0.87 (dd, 9 H, PCHCH3, J HP ) 12.9 Hz,
3
η5-C5H4-CH-CH3, J HH ) 6.6 Hz); 0.87 (dd, 9 H, PCHCH3,
3
3J HH ) 6.9 Hz); 0.85 (dd, 9 H, PCHCH3, J HP ) 12.9 Hz,
3
3J HP ) 13.2 Hz, J HH ) 6.9 Hz); 0.85 (dd, 9 H, PCHCH3,
3
3J HH ) 6.9 Hz); 0.70 (t, 3 H, η5-C5H4-CH-CH2-CH3, J HH
)
3
3J HP ) 13.2 Hz, J HH ) 6.9 Hz); 0.69 (t, 3 H, η5-C5H4-CH-
2
2
CH2-CH3, 3J HH ) 7.2 Hz); -14.72 (dd, 1 H, Os-H, 2J HP ) 27.6
7.5 Hz); -14.46 (dd, 1 H, Os-H, J HP ) 29.4 Hz, J HH ) 3.3
2
2
2
2
Hz); -14.56 (d, 1 H, Os-H, J HP ) 29.4 Hz, J HH ) 3.3 Hz).
13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ 150.0
(-, s, Cipso Ph); 136.5, 127.6 (+, s, Cortho, Cmeta Ph); 127.4
(+, s, Cpara Ph); 113.0 (-, s, quaternary C in η5-C5H4-CH-);
81.6, 76.7, 76.2, 75.5 (+, s, tertiary C’s in η5-C5H4-CH-); 33.3
(+, s, η5-C5H4-CH(CH3)CH2-CH3); 32.3 (-, s, η5-C5H4-CH-
Hz, J HH ) 3.9 Hz); -14.91 (d, 1 H, Os-H, J HP ) 27.6 Hz,
2J HH ) 3.9 Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus
APT): δ 146.9 (-, s, Cipso Ph); 136.7, 127.2 (+, s, Cortho,
Cmeta Ph); 127.6 (+, s, Cpara Ph); 112.9 (-, s, quaternary C
in η5-C5H4-CH-); 81.5, 78.8, 77.4, 76.3 (+, s, tertiary C’s in
η5-C5H4-CH-); 32.5 (+, s, η5-C5H4-CH(CH3)CH2-CH3); 32.3
CH2-); 29.8 (+, d, PCH, J CP ) 29.7 Hz); 22.0, 12.5 (+, s, η5-
1
1
(-, s, η5-C5H4-CH-CH2-); 29.2 (+, d, PCH, J CP ) 29.7 Hz);
C5H4-CH(CH3)CH2-CH3); 19.9, 19.7 (+, s, PCH-CH3). 31P-
{1H} NMR (121.4 MHz, C6D6, 293 K): δ 41.3 (s, t in off-
resonance). MS (FAB+): m/z ) 778 (M+), 701 (M+ - Ph).
21.8, 12.5 (+, s, η5-C5H4-CH(CH3)CH2-CH3); 19.9, 19.7 (+,
s, PCH-CH3). 31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 40.6
(s, t in off-resonance). MS (FAB+): m/z ) 734 (M+).
P r ep a r a tion of OsH2{η5-C5H4Si(C6H4)P h 2}(P iP r 3) (8). To
a solution of OsH(η5-C5H5)Cl(SiPh3)(PiPr3) (162 mg, 0.23 mmol)
in 10 mL of THF was added n-buthyllithium (0.5 mL), and
the mixture was left to react for 1 h. Methanol (1 mL) was
added, and the mixture was stirred for 1 min and then
vacuum-dried. The resulting residue was finally washed with
methanol (2 × 4 mL), leading to a white solid. Yield: 94 mg
P r ep a r a tion of OsH(η5-C5H5){Si(C6H4)P h 2}(P iP r 3) (11).
To a solution of OsH(η5-C5H5)Cl(SiPh3)(PiPr3) (255 mg, 0.36
mmol) and acetone (0.5 mL) in 10 mL of THF was added
n-buthyllithium (0.5 mL). The mixture was left to stir for 30
min, and methanol (1 mL) was added. After 1 min of stirring,
the solution was vacuum-dried, and the sticky residue was
washed with methanol (2 × 4 mL), leading to a white solid.
Yield: 163 mg (67%). Anal. Calcd for C32H41OsPSi: C, 56.95;
H, 6.12. Found: C, 56.53; H, 6.12. IR (Nujol, cm-1): ν(Os-H)
2137 (m), 2104 (m). 1H NMR (300 MHz, C6D6, 293 K): δ 8.30-
7.00 (14 H, -Ph); 4.69 (s, 5 H, Cp); 1.91 (m, 3 H, PCH); 0.68
(61%). Anal. Calcd for
C32H41OsPSi: C, 56.77; H, 6.41.
Found: C, 56.94; H, 6.13. IR (Nujol, cm-1): ν(Os-H) 2144,
1
2111 (m). H NMR (300 MHz, C6D6, 293 K): δ 7.90-6.90 (14
H, -Ph); 5.10-4.90 (4 H, η5-C5H4-, AA′BB′ system); 1.73 (m,
2
2
3
3
3 H, PCH); 0.77 (dd, 18 H, CH3, J HP ) 13.8 Hz, J HH ) 6.9
(dd, 9 H, PCHCH3, J HP ) 12.3 Hz, J HH ) 7.2 Hz); 0.56 (dd,
9 H, PCHCH3, 3J HP ) 12.3 Hz, 3J HH ) 7.2 Hz); -13.71 (d, 1 H,
Os-H, 2J HP ) 29.7 Hz). 13C{1H} NMR (75.4 MHz, CCl2D2, 293
K, plus APT): δ 165.2 (-, s, Os-C-C-Si); 144.1, 142.1 (-, s,
Cipso Ph); 140.1, 129.6, 128.5, 120.8 (+, s, tertiary C’s in Os-
C6H4-Si); 135.0, 133.9 (+, s, Cortho Ph); 127.8 (+, s, Cpara
Ph); 127.4, 127.3 (+, s, Cmeta Ph); 126.3 (-, d, Os-C-C-Si,
Hz); -12.76 (d, 2 H, Os-H, J HP ) 36.3 Hz). 13C{1H} NMR
2
(75.4 MHz, C6D6, 293 K, plus APT): δ 159.2 (-, s, Os-C-C-
Si); 147.8 (-, s, Cipso SiPh2); 140.6 (-, d, Os-C, 2J CP ) 6 Hz);
137.5, 135.3, 129.3, 121.1 (+, s, CH’s in Os-C6H4-Si); 136.7,
128.4 (+, s, Cortho, Cmeta Ph); 129.8 (+, s, Cpara Ph); 89.3,
89.2 (+, s, tertiary C’s in η5-C5H4-Si); 75.6 (-, d, quaternary
1
in η5-C5H4-Si); 29.2 (+, d, PCH, J CP ) 31.3 Hz); 19.9 (+, s,
1
2J CP ) 13.7 Hz); 81.6 (+, s, Cp); 26.8 (+, d, PCH, J CP ) 27.8
PCH-CH3). 31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 47.6
(s, t in off-resonance). MS (FAB+): m/z ) 674 (M+ - 2H), 598
(M+ - H-Ph).
Hz); 20.2-20.0 (+, PCH-CH3). 31P{1H} NMR (121.4 MHz,
C6D6, 293 K): δ 21.8 (s, d in off-resonance). MS (FAB+):
m/z ) 677 (M+ + H).
Rea ction of OsH(η5-C5D5)Cl(SiP h 3)(P iP r 3) w ith n Bu Li.
To a solution of OsH(η5-C5D5)Cl(SiPh3)(PiPr3) (151 mg, 0.21
mmol) was added n-buthyllithium (0.4 mL), and the mixture
was left to react for 7 min. Methanol (1 mL) was then added,
and after 1 min of stirring, the solution was vacuum-dried.
The resulting residue was washed with methanol (2 × 3 mL),
leading to a white solid which was a mixture of the complexes
P r epar ation of OsH2{η5-C5H4N(CH2CH3)2}(GeP h 3)(P iP r 3)
(12). To a solution of diethylamine (1.0 mL) in 10 mL of THF
was first added n-buthyllithium (0.3 mL) and then OsH(η5-
C5H5)Cl(GePh3)(PiPr3) (140.1 mg, 0.19 mmol). The mixture was
left to stir for 30 min, and methanol (1 mL) was added. After
1 min of stirring, the solution was vacuum-dried, and the
resulting sticky residue was washed with methanol (2 × 3 mL),
finally leading to a white solid. Yield: 82 mg (56%). Anal. Calcd
for C36H52GeNOsP: C, 54.56; H, 6.61; N: 1.77. Found: C,
54.25; H, 6.76; N: 2.14. IR (Nujol, cm-1): ν(Os-H) 2089 (m),
OsH2{η5-C5D4Si(C6H4)Ph2}(PiPr3) (8-d 4) and Os(H)(D)(η5-C5-
D4nBu)(SiPh3)(PiPr3) (9-d 5) in a 2:1 molar ratio. Spectroscopic
data for 8-d 4: 1H NMR (300 MHz, C6D6, 293 K): δ 8.10-6.90
1
2
2066 (m). H NMR (300 MHz, C6D6, 293 K): δ 8.10-7.10 (15
(14 H, -Ph); 1.73 (m, 3 H, PCH); 0.77 (dd, 18 H, CH3, J HP
)
H, -Ph); 4.50-4.00 (4 H, η5-C5H4-, AA′BB′ system); 2.52 (q,
2
2
13.8 Hz, J HH ) 6.9 Hz); -12.76 (d, 2 H, Os-H, J HP ) 36.3
Hz). 2H NMR (46.1 MHz, C6H6, 293 K): δ 5.63, 5.14 (s, η5-
C5D4-). 31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 47.6 (s).
3
4 H, N-CH2-, J HH ) 7.2 Hz); 1.46 (m, 3 H, PCH); 0.92 (dd,
3
3
18 H, PCHCH3, J HP ) 13.2 Hz, J HH ) 7.2 Hz); 0.77 (t, 6 H,
3
2
Spectroscopic data for 9-d 5: 1H NMR (300 MHz, C6D6, 293 K):
N-CH2-CH3, J HH ) 7.2 Hz); -14.10 (d, 2 H, Os-H, J HP
)
29.4 Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ
151.0 (-, s, Cipso GePh3); 136.7, 127.5 (+, s, Cortho, Cmeta
GePh3); 134.0 (-, s, quaternary C in η5-C5H4-N); 127.2 (+, s,
Cpara GePh3); 68.5, 63.0 (+, s, tertiary C’s in η5-C5H4-N); 45.7
3
δ 8.10-6.90 (15 H, -Ph); 2.01 (t, 2 H, η5-C5D4-CH2-, J HH
)
7.2 Hz); 1.37 (m, 3 H, PCH); 1.40-1.10 (m, 4 H, -CH2-CH2-);
0.85 (dd, 18 H, PCHCH3, 3J HP ) 13.5 Hz, 3J HH ) 7.2 Hz); 0.82-
2
2
0.76 (3 H, -CH3); -14.84 (d, 1 H, Os-H, J HP ) 29.4 Hz). H
NMR (46.1 MHz, C6H6, 293 K): δ 4.82, 4.65 (s, 4 D, η5-C5D4-);
-14.78 (d, 1 D, Os-D,2J DP ) 2.6 Hz). 31P{1H} NMR (121.4 MHz,
C6D6, 293 K): δ 41.4 (s).
1
(-, s, -N-CH2-); 29.7 (+, d, PCH, J CP ) 28.1 Hz); 20.1 (+,
s, PCH-CH3); 12.9 (+, s, -N-CH2-CH3). 31P{1H} NMR (121.4
MHz, C6D6, 293 K): δ 40.2 (s, t in off-resonance). MS (FAB+):
m/z ) 793 (M+), 716 (M+ - Ph), 487 (M+ - GePh3 - 3H).
P r ep a r a tion of OsH2{η5-C5H4CH(CH3)CH2CH3}(SiP h 3)-
(P iP r 3) (10). To a solution of OsH(η5-C5H5)Cl(SiPh3)(PiPr3)
(195 mg, 0.27 mmol) in 10 mL of THF was added sec-
buthyllithium (0.3 mL), and the mixture was left to react for
P r epa r a tion of OsH2{η5-C5H4N(CH2CHdCH2)2}(GeP h 3)-
(P iP r 3) (13). To a solution of diallylamine (0.5 mL) in 10 mL
of THF was first added n-buthyllithium (0.4 mL) and then

252 Organometallics, Vol. 20, No. 2, 2001
Baya et al.
OsH(η5-C5H5)Cl(GePh3)(PiPr3) (130 mg, 0.17 mmol). The mix-
ture was left to stir for 30 min, and methanol (1 mL) was
added. After 1 min of stirring, the solution was vacuum-dried,
and the resulting sticky residue was washed with methanol
(2 × 3 mL), leading to a white solid. Yield: 75 mg (53%). Anal.
Calcd for C38H52GeNOsP: C, 55.88; H, 6.43; N: 1.72. Found:
C, 56.27; H, 6.80; N: 2.00. IR (Nujol, cm-1): ν(Os-H) 2083
{1H} NMR (121.4 MHz, C6D6, 293 K): δ 38.8 (s, t in off-
resonance). MS (FAB+): m/z ) 773 (M+).
P r ep a r a tion of OsH2(η5-C5H4P P h 2)(GeP h 3)(P iP r 3) (16).
To a solution of diphenylphosphine (0.15 mL) in 10 mL of THF
was first added n-buthyllithium (0.15 mL) and then OsH(η5-
C5H5)Cl(GePh3)(PiPr3) (211.2 mg, 0.28 mmol). The mixture was
left to stir for 1 h, and methanol (1 mL) was added. After 1
min of stirring, the solution was vacuum-dried, and the
resulting sticky residue was washed with methanol (2 × 4 mL),
leading to a white solid. Yield: 147 mg (58%). Anal. Calcd for
C44H52GeOsP2: C, 58.35; H, 5.79. Found: C, 58.03; H, 5.45.
1
(m), 2062 (m). H NMR (300 MHz, C6D6, 293 K): δ 8.10-7.10
(15 H, -Ph); 5.60 (ddt, 2 H, -CH2-CHdCH2, 3J HH ) 17.1 Hz,
2
2J HH ) 11.4 Hz; J HH ) 5.7 Hz); 4.98 (dd, 2 H, H trans to
3
2
-CH2- in -CHdCH2, J HH ) 17.1 Hz, J HH ) 1.5 Hz); 4.93
1
IR (Nujol, cm-1): ν(Os-H) 2168 (m), 2112 (m). H NMR (300
3
(dd, 2 H, H cis to -CH2- in -CHdCH2, J HH ) 11.4 Hz,
2J HH ) 1.5 Hz); 4.50-4.10 (4 H, η5-C5H4-, AA′BB′ system);
MHz, C6D6, 293 K): δ 7.90-7.00 (25 H, -Ph); 4.80-4.50 (4 H,
η5-C5H4-, AA′BB′ system); 1.49 (m, 3 H, PCH); 0.87 (dd, 18
3
3.15 (d, 4 H, N-CH2-, J HH ) 5.7 Hz); 1.44 (m, 3 H, PCH);
2
2
2
2
H, PCHCH3, J HP ) 13.5 Hz, J HH ) 7.2 Hz); -14.40 (dd, 2 H,
0.91 (dd, 18 H, PCHCH3, J HP ) 13.2 Hz, J HH ) 7.2 Hz);
Os-H, J HP ) 29.4 Hz, J HP ) 3.6 Hz). 13C{1H} NMR (75.4
2
3
2
-14.12 (d, 2 H, Os-H, J HP ) 29.7 Hz). 13C{1H} NMR (75.4
MHz, C6D6, 293 K, plus APT): δ 149.2 (-, s, Cipso -GePh3);
MHz, C6D6, 293 K, plus APT): δ 150.5 (-, s, Cipso GePh3);
136.3, 127.1 (+, s, Cortho, Cmeta GePh3); 134.5 (+, s, -CHd
CH2); 131.2 (-, s, quaternary C in η5-C5H4-N); 126.9 (+, s,
Cpara GePh3); 116.6 (-, s, -CHdCH2); 68.6, 64.3 (+, s, tertiary
C’s in η5-C5H4-N); 54.8 (-, s, -N-CH2-); 29.3 (+, s, PCH);
19.4 (+, s, PCH-CH3). 31P{1H} NMR (121.4 MHz, C6D6, 293
K): δ 39.8 (s, t in off-resonance). MS (FAB+): m/z ) 817 (M+),
740 (M+ - Ph), 513 (M+ - GePh3 - H).
1
139.4 (-, d, Cpara -PPh2, J CP ) 12.9 Hz); 136.4, 127.7 (+, s,
2
Cortho, Cmeta -GePh3); 134.4 (+, d, Cortho -PPh2, J CP
)
19.8 Hz); 129.4 (+, s, Cpara -PPh2); 129.1 (+, d, Cmeta -PPh2,
3J CP ) 6.4 Hz); 127.4 (+, s, Cpara -GePh3); 93.4 (-, d,
quaternary C in η5-C5H4-P, J CP ) 18.4 Hz); 86.1 (+, d, one
1
of the tertiary C’s in η5-C5H4-P, J CP ) 15.2 Hz); 79.5 (+, s,
2
one of the tertiary C’s in η5-C5H4-P); 30.1 (+, d, PCH, J CP
)
1
29.5 Hz); 19.8 (+, s, PCH-CH3). 31P{1H} NMR (121.4 MHz,
C6D6, 293 K): δ 39.3 (s, PiPr3, t in off-resonance); -17.4 (s,
-PPh2, s in off-resonance). MS (FAB+): m/z ) 906 (M+), 829
(M+ - Ph).
P r epar ation of OsH2{η5-C5H4N(CH2CH3)2}(SiP h 3)(P iP r 3)
(14). To a cold solution of diethylamine (0.5 mL) in 10 mL of
THF (-78 °C) was first added n-buthyllithium (0.2 mL) and
then OsH(η5-C5H5)Cl(SiPh3)(PiPr3) (216.5 mg, 0.30 mmol). The
mixture was left to stir for 20 min, and methanol (1 mL) was
added. After 1 min of stirring, the solution was vacuum-dried,
and the resulting sticky residue was then washed with
methanol (2 × 3 mL), leading to a white solid. Yield: 102 mg
(45%). Anal. Calcd for C36H52NOsPSi: C, 57.79; H, 7.02; N:
1.87. Found: C, 57.40; H, 6.68; N: 2.01. IR (Nujol, cm-1):
ν(Os-H) 2095 (m). 1H NMR (300 MHz, C6D6, 293 K): δ 8.10-
7.10 (15 H, -Ph); 4.50-4.00 (4 H, η5-C5H4-, AA′BB′ system);
P r ep a r a tion of OsH2(η5-C5H4P P h 2)(SiP h 3)(P iP r 3) (17).
To a solution of diphenylphosphine (0.15 mL) in 10 mL of THF
was first added n-buthyllithium (0.20 mL) and then OsH(η5-
C5H5)Cl(SiPh3)(PiPr3) (301 mg, 0.42 mmol). The mixture was
left to stir for 1 h, and methanol (1 mL) was added. After 1
min of stirring, the resulting solution was vacuum-dried,
generating a sticky residue, which was washed with methanol
(2 × 4 mL), finally leading to a white solid. Yield: 195 mg
(54%). Anal. Calcd for C44H52OsP2Si: C, 61.37; H, 6.09.
Found: C, 61.62; H, 6.41. IR (Nujol, cm-1): ν(Os-H) 2191 (m),
3
2.52 (q, 4 H; N-CH2-, J HH ) 7.2 Hz); 1.40 (m, 3 H, PCH);
2
2
0.93 (dd, 18 H, PCHCH3, J HP ) 13.2 Hz, J HH ) 7.2 Hz); 0.75
1
2137 (m). H NMR (300 MHz, C6D6, 293 K): δ 8.00-7.00 (25
3
2
(t, 6 H; -CH3, J HH ) 7.2 Hz); -14.45 (d, 2 H, Os-H, J HP
)
H, -Ph); 4.80-4.40 (4 H, η5-C5H4-, AA′BB′ system); 1.46 (m,
28.2 Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ
149.1 (-, s, Cipso SiPh3); 137.4, 126.7 (+, s, Cortho, Cmeta
SiPh3); 134.6 (-, s, quaternary C in η5-C5H4-N); 127.0 (+, s,
Cpara SiPh3); 70.8, 63.1 (+, s, tertiary C’s in η5-C5H4-N); 44.7
(-, s, -N-CH2-); 28.3 (+, s, PCH); 19.7 (+, s, PCH-CH3);
12.3 (+, s, -N-CH2-CH3). 31P{1H} NMR (121.4 MHz, C6D6,
293 K): δ 38.9 (s, t in off-resonance). MS (FAB+): m/z ) 749
(M+), 672 (M+ - Ph), 487 (M+ - SiPh3 - 3H).
2
2
3 H, PCH); 0.88 (dd, 18 H, PCHCH3, J HP ) 13.5 Hz, J HH
)
2
3
7.2 Hz); -14.65 (dd, 2 H, Os-H, J HP ) 28.2 Hz, J HP ) 2.7
Hz). 13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ 147.9
1
(-, s, Cipso -SiPh3); 139.6 (-, d, Cipso -PPh2, J CP ) 12.9
Hz); 137.5, 127.3 (+, s, Cortho, Cmeta -SiPh3); 134.4 (+, d,
2
Cortho, -PPh2, J CP ) 20.3 Hz); 129.3 (+, s, Cpara -PPh2);
1
129.1 (+, d, Cmeta -PPh2, J CP ) 6.9 Hz); 127.7 (+, s, Cpara
-SiPh3); 91.8 (-, d, quaternary C in η5-C5H4-P, J CP ) 18.4
1
P r ep a r a tion of OsH2{η5-C5H4N(CH2CHdCH2)2}(SiP h 3)-
(P iP r 3) (15). To a solution of diallylamine (0.5 mL) in 10 mL
of THF was first added n-buthyllithium (0.5 mL) and then
OsH(η5-C5H5)Cl(SiPh3)(PiPr3) (239 mg, 0.34 mmol). The mix-
ture was left to stir for 1 h, and methanol (1 mL) was added.
After 1 min of stirring, the solution was vacuum-dried, and
the resulting sticky residue was washed with methanol (2 ×
4 mL), leading to a white solid which was a (2:1) mixture of
Hz); 87.7 (+, dd, one of the tertiary C’s in η5-C5H4-P, J CP
)
2
2
12.5 Hz, J CP ) 2.8 Hz); 80.9 (+, s, one of the tertiary C’s in
η5-C5H4-P); 29.6 (+, d, PCH, 1J CP ) 29.0 Hz); 19.8 (+, s, PCH-
CH3). 31P{1H} NMR (121.4 MHz, C6D6, 293 K): δ 38.4 (s, PiPr3,
t in off-resonance); -18.0 (s, -PPh2, s in off-resonance).
MS (FAB+): m/z ) 862 (M+ - H), 785 (M+ - Ph), 600 (M+
SiPh3 - H).
-
X-r a y Str u ctu r e An a lysis of Com p lexes OsH 2{η5-C5H4-
1
15 and 8. IR (Nujol, cm-1): ν(Os-H) 2091 (s). H NMR (300
Si(C6H 4)P h 2}(P iP r 3) (8) a n d OsH 2{η5-C5H 4N(CH 2-CH d
CH2)2}(GeP h 3)(P iP r 3) (13). Crystals suitable for X-ray dif-
fraction analysis were mounted onto a glass fiber and
transferred to a Bruker-Siemens P-4 (8, T ) 200.0(2) K) and
Bruker-Siemens-STOE AED-2 (13, T ) 298.0(2) K) automatic
diffractometers (Mo KR radiation, graphite monocromator, λ
) 0.71073 Å). Accurate unit cell parameters were determined
by least-squares fitting from the settings of high-angle reflec-
tions. Data were collected by the ω/2θ Å scan method. Lorentz
and polarization corrections were applied. Decay was moni-
tored by measuring three standards throughout data collection.
Corrections for decay and absortion (semiempirical ψ-scan
method) were also applied.
MHz, C6D6, 293 K): δ 8.10-7.10 (15 H, -Ph); 5.59 (ddt, 2 H,
-CH2-CHdCH2, J HH ) 13.8 Hz, J HH ) 6.9 Hz; J HH ) 5.7
3
2
2
3
Hz); 4.98 (dd, 2 H, H trans to -CH2- in -CHdCH2, J HH
)
2
13.8 Hz, J HH ) 1.5 Hz); 4.93 (dd, 2 H, H cis to -CH2- in
3
2
-CHdCH2, J HH ) 6.9 Hz, J HH ) 1.5 Hz); 4.50-4.10 (4 H,
η5-C5H4-, AA′BB′ system); 3.13 (d, 4 H, N-CH2-, J HH ) 5.7
3
Hz); 1.37 (m, 3 H, PCH); 0.91 (dd, 18 H, PCHCH3, 2J HP ) 12.9
2
2
Hz, J HH ) 7.2 Hz); -14.45 (d, 2 H, Os-H, J HP ) 27.9 Hz).
13C{1H} NMR (75.4 MHz, C6D6, 293 K, plus APT): δ 149.5
(-, s, Cipso SiPh3); 136.7, 127.2 (+, s, Cortho, Cmeta SiPh3);
134.9 (+, s, -CHdCH2); 133.7 (-, s, quaternary C in η5-C5H4-
N); 127.5 (+, s, Cpara SiPh3); 117.0 (-, s, -CHdCH2); 71.5,
64.9 (+, s, tertiary C’s in η5-C5H4-N); 54.5 (-, s, -N-CH2-);
28.9 (+, d, PCH, J CP ) 28.2 Hz); 19.9 (+, s, PCH-CH3). 31P-
The structures were solved by Patterson methods and
1

Cyclopentadienyl Ligands in Os(IV) Chemistry
Organometallics, Vol. 20, No. 2, 2001 253
refined by full matrix least-squares on F2 (8 and 13).32 The
triisopropylphosphine ligand of 8 was found to be disordered
and refined with two moieties (a and b) with complementary
occupancy factors and isotropic thermal parameters. The
remaining non-hydrogen atoms were anisotropically refined,
and the hydrogen atoms were observed or included at idealized
positions. Hydride ligands H(01) and H(02) (8 and 13) were
located in the difference Fourier maps and refined isotropi-
cally.
cimiento) for financial support. M.B. thanks the DGA
(Diputacio´n General de Arago´n) for a grant.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and equivalent isotropic displacement coefficients,
anisotropic thermal parameters, experimental details of the
X-ray studies, and bond distances and angles for 8 and 13.
This material is available free of charge via the Internet at
http://pubs.acs.org.
OM000789M
Ack n ow led gm en t. We thank the DGES (Project
PB98-1591, Programa de Promocio´n General del Cono-
(32) Sheldrick, G. M. SHELX-97; Go¨ttingen, 1997.