An osmium-carbene complex with fischer-schrock ambivalent behavior

Article abstract of DOI:10.1021/om0208826

Complex Os(η⁵-C₅H₅) Cl(PⁱPr₃)₂ (1) reacts with N₂CHPh to give the carbene derivative Os(η⁵-C₅H₅) (=CHPh)Cl(PⁱPr₃) (2). Comp

Full text of DOI:10.1021/om0208826

414
Organometallics 2003, 22, 414-425
An Osm iu m -Ca r ben e Com p lex w ith F isch er -Sch r ock
Am biva len t Beh a vior
Miguel A. Esteruelas,* Ana I. Gonza´lez, Ana M. Lo´pez,* 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 October 23, 2002
Complex Os(η5-C5H5)Cl(PiPr3)2 (1) reacts with N2CHPh to give the carbene derivative
Os(η5-C5H5)(dCHPh)Cl(PiPr3) (2). Complex 2 affords the carbene-plus-organic fragment
coupling products Os(η5-C5H5)(η3-CHPhC6H5)(PiPr3) (3), OsH(η5-C5H5)(CH2dCHPh)(PiPr3),
(4) and OsH(η5-C5H5){η2-(E)-CHPh)CHCHdCH2}(PiPr3) (5) by reaction with PhLi, MeLi,
and CH2dCHCH2MgCl, respectively. In solution, the phenyl groups of 3 exchange their
positions. The fluxional process takes place via an alkyl intermediate, which can be trapped
as Os(η5-C5H5)(CHPh2)(CO)(PiPr3) (6) under CO atmosphere. In toluene at 60 °C, complex 5
evolves into its allyl isomer Os(η5-C5H5){η3-CH2CHCH(CH2Ph)}(PiPr3) (7). Complex 2 also
reacts with HBF4 and NaOCH3. The reaction with HBF4 leads to [Os(η5-C5H5)(η3-CH2C6H5)Cl-
(PiPr3)]BF4 (8), which loses HCl to give the hydride-carbyne derivative [OsH(η5-C5H5)(tCPh)-
(PiPr3)]+ (9), while the reaction with NaOCH3 affords the carbyne compound Os(η5-
C5H5)(tCPh) (PiPr3) (10). In methanol as solvent, complex 10 evolves into the hydride-
alkoxycarbene species OsH(η5-C5H5){dC(OMe)Ph}(PiPr3) (11). The reaction of 10 with phenol
in pentane leads to OsH(η5-C5H5){CH(Ph)OC6H4}(PiPr3) (12). The X-ray structures of 3, 5,
7, 9, and 12 are also reported.
In tr od u ction
center.3 These compounds contain an early transition
metal in high oxidation state and have hydrogen or alkyl
substituents on the carbene.
Transition-metal carbene complexes are one of the
most useful tools in organic synthesis and homogeneous
catalysis, including cyclopropanation reactions, olefin
metathesis, and Fischer-Tropsch synthesis.1
In the Fisher-type complexes the π electrons appear
to be polarized toward the metal, while in the complexes
of the Schrock-type the π electrons appear to be nearly
equally distributed.3a This electronic situation is in
agreement with the observed dichotomy in behavior
between these systems. Characteristic of the Fischer-
type derivatives is the electrophilicity of the carbene-
carbon atom, which is the preferred site of attack for
nucleophilic reagents, while, in contrast to the Fischer
carbenes, electrophiles add to the carbene-carbon of the
Schrock-type. Likewise, strong bases result in deproto-
nation of the carbene-carbon atom.4
One of the most significant recent developments in
the area of carbene chemistry has been the synthesis
of the ruthenium carbene complexes RuCl2(dCR2)(PR′3)2
and their use as olefin metathesis catalysts.5 Since the
advent of these systems, a great deal of interest has
been given to the synthesis of carbene derivatives of the
iron triad with non-Fischer-type substituents.6 Various
osmium(0) and osmium(II) compounds containing an
OsdCR2 unit have been prepared;7 however, half-
sandwich-type osmium complexes with a carbene ligand
are very scarce.8 Despite the carbene ligands bearing
These compounds have been divided into two
classes: the Fischer-type and the Schrock-type.2
Fischer-type complexes are viewed as a singlet-state
carbene donating to the metal from its sp2-hybrid
orbital, with a corresponding amount of back-donation
from the metal to the empty π orbital. The distances
between the carbene-carbon and its substituents (het-
eroatoms or phenyl groups) are short relative to single
bonds. They contain a metal from groups VI to VIII,
which is present in a low oxidation state, and it is
stabilized by a series of other ligands with pronounced
acceptor properties.
Complexes of the Schrock-type are viewed as a triplet-
state carbene spin-coupled to two electrons on the metal
* Corresponding author. E-mail: maester@posta.unizar.es. Fax: 34
976761187.
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10.1021/om0208826 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 12/24/2002

Osmium-Carbene Complex
Organometallics, Vol. 22, No. 3, 2003 415
no stabilizing heteroatoms, these compounds are gener-
ally viewed as Fischer-type derivatives.
hydrogen, or group 14 element hydride compounds, to
give a wide range of novel organometallic derivatives.
Recently, we have observed that complex Os(η5-C5H5)Cl-
(PiPr3)2 also reacts with phenyldiazomethane, to afford
Os(η5-C5H5)(dCHPh)Cl(PiPr3).
The easy accesibility to this compound prompted us
to investigate the electrophilicity or nucleophilicity of
the carbene-carbon of the new derivative, as a part of
our work on the capacity of the osmium-carbon mul-
tiple bonds to promote carbon-carbon and carbon-
heteroatom coupling reactions.10 In this paper, we
report the Fischer-Schrock ambivalent nature of
Os(η5-C5H5)(dCHPh)Cl(PiPr3).
We have previously reported overwhelming evidence
showing that the complex Os(η5-C5H5)Cl(PiPr3)2 is a
useful starting material for the development of the
osmium-cyclopentadienyl chemistry.8b,9 The large steric
hindrance experienced by the triisopropylphosphine
groups, which are mutually cis disposed, labilizes an
Os-P bond. As a result, this complex reacts with weak
donor ligands, including olefins, alkynes, molecular
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Resu lts a n d Discu ssion
P r ep a r a t ion of Os(η5-C5H 5)(dCH P h )Cl(P iP r 3).
Treatment of a toluene solution of Os(η5-C5H5)Cl(PiPr3)2
(1) with a toluene solution of phenyldiazomethane at
room temperature produces a rapid evolution of gas (N2)
and a change of color in the starting solution from
orange to green. Removal of the solvent and recrystal-
lization of the residue from hexane affords complex
Os(η5-C5H5)(dCHPh)Cl(PiPr3) (2) as a dark blue solid
in about 70% yield (eq 1).
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We note that recently the synthesis of the related
ruthenium complex Ru(η5-C5H5)Cl(dCPh2)(PPh3) has
been reported. In contrast to 2, the formation of this
compound requires higher temperature and a large
excess of N2CPh2, which must be added in several
portions during the reaction.6u Previous attemps to
obtain Ru(η5-C5H5)Cl{dC(aryl)2}(PPh3) and Os(η6-mes)-
Cl2{dC(aryl)2} from Ru(η5-C5H5)Cl(PPh3)2 and [Os(η6-
mes)Cl2]n (mes ) 1,3,5-C6H3Me3), respectively, and the
corresponding diazomethanes had failed. Their synthe-
ses require multistep procedures, using the carboxylate
compound Ru(η5-C5H5){κ2-O2CCH3}(PPh3) or Os(η6-
mes){κ1-OC(O)CF3}(κ2-O2CCF3) as synthetic intermedi-
ate species.8b,11
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carbon and carbon-heteroatom coupling reactions. In Recent Advances
in Hydride Chemistry; Peruzzini, M., Poli, R., Eds.; Elsevier: Amster-
dam, 2001; Chapter 7, pp 189-248.
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416 Organometallics, Vol. 22, No. 3, 2003
Esteruelas et al.
Sch em e 1
F igu r e 1. Molecular diagram of the complex Os(η5-C5H5)-
(η3-CHPhC6H5)(PiPr3) (3).
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for th e Com p lex
Os(η5-C5H5)(η3-CHP h C6H5)(P iP r 3) (3)
In the 1H NMR spectrum of 2 in benzene-d6, the most
noticeable resonance is that corresponding to the CH-
carbene proton, which appears at 19.17 ppm as a
doublet with a H-P coupling constant of 12.9 Hz. In
the 13C{1H} NMR spectrum, the CR resonance of the
carbene ligand is observed as a broad signal at 235 ppm.
This resonance is considerably shifted to higher field
compared with Os(η6-mes){κ1-OC(O)CF3}2{dC(aryl)2}
(δ, 306-310), Os(η6-mes)Cl2{dC(aryl)2} (δ, 300-303),
[Os(η6-mes)Cl{dC(aryl)2}(PPh3)]PF6 (δ, 291-293),8b
and [Os(η5-C5H5)(dCHCH2Ph){P(OMe)3}(PiPr3)]BF4 (δ,
285.7).8c,9 The 31P{1H} NMR spectrum contains a singlet
at 20.7 ppm.
Os-P
2.3360(10)
2.185(4)
2.157(4)
2.246(4)
2.195(4)
2.195(4)
2.202(4)
Os-C(26)
Os-C(27)
C(1)-C(2)
C(1)-C(8)
C(8)-C(13)
2.181(4)
2.217(4)
1.500(5)
1.429(5)
1.435(5)
Os-C(1)
Os-C(8)
Os-C(13)
Os-C(23)
Os-C(24)
Os-C(25)
P-Os-Ma
123.52(4)
89.30(11)
110.31(11)
91.42(11)
138.21(17)
Ma-Os-C(8)
125.93(16)
129.33(17)
38.43(14)
66.63(16)
37.98(14)
119.9(4)
P-Os-C(1)
P-Os-C(8)
P-Os-C(13)
Ma-Os-C(1)
Ma-Os-C(13)
C(1)-Os-C(8)
C(1)-Os-C(13)
C(8)-Os-C(13)
C(2)-C(1)-C(8)
a
M represents the midpoint of the C(23)-C(27) Cp ring.
Rea ction s of Os(η5-C5H5)(dCHP h )Cl(P iP r 3) w ith
RLi (R ) P h , Me) a n d CH2dCHCH2MgCl. The
carbene-carbon atom of 2 shows a marked electrophi-
licity, characteristic of the Fischer-type derivatives.
Thus complex 2 reacts with main group organometallic
compounds, such as phenyllithium, methyllithium, and
allylmagnesium chloride, to afford novel carbene-plus-
organic fragment coupling processes (Scheme 1).
the organic fragment to the carbene-carbon atom, may
be also considered.
Figure 1 shows a view of the molecular geometry of
the benzoallyl complex 3. Selected bond distances and
angles are listed in Table 1. The coordination geometry
around the osmium atom can be rationalized as being
derived from a highly distorted octahedron with the
cyclopentadienyl ligand occupying a face.
The addition at 0 °C of a cyclohexane/diethyl ether
(7:3) solution of phenyllithium to the stoichiometric
amount of 2 in tetrahydrofuran leads to the benzoallyl
complex Os(η5-C5H5)(η3-CHPhC6H5)(PiPr3) (3), which
was isolated as orange crystals in 65% yield. At the
same temperature, the treatment of the tetrahydrofuran
solutions of 2 with the stoichiometric amount of meth-
yllithium in diethyl ether affords the hydride-styrene
derivative OsH(η5-C5H5)(CH2dCHPh)(PiPr3) (4), as a
dark brown oil in 75% yield, whereas the reaction of 2
with allylmagnesium chloride in tetrahydrofuran gives
rise to the hydride-η2-phenylbutadiene compound OsH-
(η5-C5H5){η2-(E)-CHPhdCHCHdCH2}(PiPr3) (5). Com-
plex 5 was isolated as a pale yellow solid in 75% yield.
The structure proves the formation of the diphenyl-
methyl ligand, which is η3-coordinated to the osmium
center through the methine carbon atom (C(1)) and two
of the arene carbon atoms of one of the phenyl substit-
uents, the ipso C(8) and one of the ortho-arene carbon
atoms (C(13)). The C-C bond lengths inside of the allyl
unit are 1.429(5) Å (C(1)-C(8)) and 1.435(5) Å (C(8)-
C(13)). The phenyl substituent is syn disposed with
regard to C(8), with an angle of 119.9(4)°. As it has been
previously observed for other transition-metal benzoallyl
complexes,12 the allyl moiety of 3 is unsymmetrically
bonded to the metal center. However, in this case, the
strongest interaction corresponds to the ipso carbon
atom (Os-C(8) ) 2.157(4) Å), whereas the difference
The reactions shown in Scheme 1 can be rationalized
as the addition of the nucleophilic organic fragments to
the carbene-carbon atom of 2, followed by the elimina-
tion of chloride and subsequent η1/η3 benzyl rearrange-
ment in 3 or â-hydrogen extraction in 4 and 5. An
alternative pathway involving carbene-(η1-organic frag-
ment) metal species, which evolve into the same inter-
mediates as those resulting from the direct attack of
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J . Chem. Ber. 1994, 127, 27. (d) Debad, J . D.; Legzdins, P.; Lumb, S.
A.; Rettig, S. J .; Batchelor, R. J .; Einstein, F. W. B. Organometallics
1999, 18, 3414. (e) Pflug, J .; Erker, G.; Kehr, G.; Fro¨hlich, R. Eur. J .
Inorg. Chem. 2000, 1795. (f) Nettekoven, U.; Hartwig, J . F. J . Am.
Chem. Soc. 2002, 124, 1166. (g) Ortmann, D. A.; Weberndo¨rfer, B.;
Ilg, K.; Laubender, M.; Werner, H. Organometallics 2002, 21, 2369.

Osmium-Carbene Complex
Organometallics, Vol. 22, No. 3, 2003 417
between the interactions of osmium-methine carbon
(Os-C(1) ) 2.185(4) Å) and osmium-ortho carbon
(Os-C(13) ) 2.246(4) Å) is relatively small. This un-
usual finding is probably related with the steric hin-
drance experienced by the phenyl group bonded at C(1).
The coordination of C(8) and C(13) to the osmium atom
produces a slight alteration in the six-membered ring
containing these atoms. Thus, the bond lengths
C(8)-C(9), C(10)-C(11), and C(12)-C(13) (1.450(5),
1.422(5), and 1.438(6) Å, respectively) are considerably
longer than the distances C(9)-C(10) and C(11)-C(12)
(1.347(5) and 1.351(5) Å, respectively), which have more
double-bond character.
ment of this resonance toward lower field with regard
to those expected for alkyl protons is probably a
consequence of the negative shielding contribution
produced by the ring current effect of the phenyl
substituents of the diphenylmethyl group. In the
13C{1H} NMR spectrum, the resonance due to the
C(sp3) atom of the alkyl group appears at 10.0 ppm, as
a doublet with a C-P coupling constant of 5.5 Hz. In
addition, it should be mentioned the resonance corre-
sponding to the carbonyl group, which is observed at
189.2 ppm, as a doublet with a C-P coupling constant
of 12.9 Hz. The 31P{1H} NMR spectrum contains a
singlet at 16.9 ppm.
In solution, complex 3 is fluxional. The process
involves the phenyl groups, which exchange their posi-
tions. According to this, at room temperature, the H
The hydride-styrene complex 4 was characterized by
1
MS, IR, H, 13C{1H}, and 31P{1H} NMR spectroscopies.
1
In agreement with the presence of a hydride ligand in
this complex, the IR spectrum in Nujol contains a
ν(Os-H) absorption at 2107 cm-1. At -10 °C, the 1H
NMR spectrum in dichloromethane-d2 strongly supports
the stereochemistry proposed for 4 in Scheme 1. In the
high-field region of the spectrum (δ, -16.30), the hy-
dride ligand gives rise to a double doublet by spin
coupling with the phosphorus atom of the phosphine
(33.6 Hz) and the olefinic CH-hydrogen disposed trans
to the phenyl group (3.9 Hz). This hydrogen atom gives
rise to a double doublet of doublets at 2.00 ppm by spin
coupling with the hydride and the olefinic hydrogens
(J gem ) 3.2 Hz, J cis ) 7.6 Hz), whereas the resonance
corresponding to the CH-hydrogen disposed cis to the
phenyl group appears at 2.60 ppm as a double doublet
with a trans H-H coupling constant of 9.0 Hz. The
resonance due to the CHPh-hydrogen is observed as a
double doublet of doublets with a H-P coupling constant
of 8.3 Hz. It should be noted that the hydrogen atoms
of the coordinated olefin disposed cisoid-syn with regard
to the hydride and phosphine ligands undergo spin
coupling with the respective active nuclei of these
ligands. At room temperature, the olefinic hydrogen
atoms display broad resonances, as a result of the
rotation of the olefin around the osmium-olefin axis.
NMR spectrum in dichloromethane-d2 shows a doublet
at 1.84 ppm, with a H-P coupling constant of 14.1 Hz
due to the C(1)-H proton, and a broad resonance
between 6 and 8 ppm corresponding to the aromatic
protons. At -40 °C, the broad resonance is resolved and,
in addition, the spectrum contains a double doublet at
3.86 ppm, with H-P and H-H coupling constants of
14.4 and 5.6 Hz, respectively, due to the C(13)-H
proton. The resonance at 1.84 ppm does not show
significant changes. The 13C{1H} NMR spectrum in
1
dichloromethane-d2 at -40 °C is consistent with the H
NMR spectrum and is in agreement with the structure
shown in Figure 1. The most noticeable resonances are
two doublets at 33.4 and 40.7 ppm, with C-P coupling
constants of 7.2 and 4.3 Hz, respectively, and a singlet
1
at 78.2 ppm. On the basis of a H-13C HMQC spectrum,
these resonances are assigned to C(1), C(13), and C(8),
respectively. At -40 °C, the 31P{1H} NMR spectrum
shows a singlet at 15.3 ppm.
The exchange process of the phenyl groups takes place
via an unsaturated η1-diphenylmethyl intermediate,
which is trapped when the dichloromethane solutions
of 3 are stirred at room temperature under 1 atm of
carbon monoxide. Under these conditions, complex
Os(η5-C5H5)(CHPh2)(CO)(PiPr3) (6) is formed. Complex
6 was isolated as a white solid in 73% yield (eq 2).
1
According to the H-13C HMQC spectrum at -10 °C,
in the 13C{1H}, the olefinic resonances appear at 20.5
(CHPh) and 1.28 (CH2) ppm, as singlets. These chemical
shifts, which are typical for C(sp3) atoms, suggest that
the acceptor component of the osmium-styrene bond
has a very important contribution to the structure of 4.
The 31P{1H} NMR spectrum contains a singlet at 31.4
ppm.
Complex 5 was characterized by elemental analysis,
1
IR, H, 13C{1H}, and 31P{1H} NMR spectroscopies, and
X-ray diffraction analysis. Figure 2 shows a view of the
molecular geometry, whereas selected bond distances
and angles are listed in Table 2. The hydride ligand
H(01) was located in the difference Fourier maps and
refined as an isotropic atom together with the rest of
the non-hydrogen atoms of the structure, giving an
Os-H(01) distance of 1.570(1) Å. The distribution of
ligands around the osmium atom can be described
as a four-legged piano-stool geometry with the hy-
dride and phosphine ligands mutually cisoid disposed
(P-Os-H(01) ) 74.3(12)°).
The presence of a carbonyl ligand in 6 is strongly
supported by the IR spectrum of this compound in Nujol,
which contains a ν(CO) absorption at 1895 cm-1. In the
1H NMR spectrum in benzene-d6 at room temperature,
the most noticeable resonance is a doublet with a H-P
coupling constant of 3.5 Hz, at 5.35 ppm, corresponding
to the C(sp3)-H proton of the alkyl ligand. The displace-
The most remarkable features of the structure are,
first, the coordination of the C(3) and C(4) atoms of the
styryl moiety of the phenylbutadiene and, second, the

418 Organometallics, Vol. 22, No. 3, 2003
Esteruelas et al.
The disposition of the coordinated olefinic bond in the
coordination sphere of the osmium is consistent with
the spectroscopic data obtained for 5, which are in full
agreement with those of 4. The IR spectrum of 5
contains a ν(Os-H) absorption at 2111 cm-1. Because
the hydride ligand is cisoid-syn disposed to the
phenyl group, and the phosphine ligand is cisoid-syn
1
disposed to the C(3)H-hydrogen, in the H spectrum in
benzene-d6 at room temperature, the hydride resonance
(δ, -16.06) only shows spin coupling with the phospho-
rus of the phosphine (35.1 Hz), whereas the C(3)-H
resonance (δ, 3.33) shows spin coupling with the phos-
phorus (9.3 Hz) and with the C(4)H- and C(2)H-
hydrogens of the diene (9.3 Hz in both cases). The
C(4)H-hydrogen displays a doublet at 4.70 ppm. The
resonances due to the hydrogen atoms of the vinyl
moiety of the diene are observed at 5.78 (C(2)H), 5.14
(C(1)H trans to C(2)H), and 4.79 (C(1)H cis to C(2)H)
ppm, with cis-, trans-, and gem-H-H coupling con-
stants of 10.2, 16.8, and 2.1 Hz, respectively. In the
13C{1H} NMR spectrum the resonances corresponding
to the coordinated C(sp2) atoms appear at 24.3 (C(4))
and 23.4 (C(3)), as doublets with C-P coupling con-
stants of 2 and 5 Hz, respectively, while the vinyl carbon
atoms give rise to singlets at 151.8 (C(2)) and 103.9
(C(1)). The 31P{1H} NMR spectrum contains a singlet
at 31.9 ppm.
In contrast to 4, in solution at room temperature, the
osmium-olefin bond in 5 is rigid. When we tried to force
the rotation of the olefin, the formation of a new
compound was observed. The heating at 60 °C of the
toluene or benzene-d6 solutions of 5 gives rise to the allyl
complex Os(η5-C5H5){η3-CH2CHCH(CH2Ph)}(PiPr3) (7),
as a result of the migratory insertion of C(4) into the
Os-H bond. After 6 h, the conversion of 5 into 7 is
quantitative. Complex 7 was isolated as a white solid
by addition of methanol (eq 3).
F igu r e 2. Molecular diagram of the complex OsH(η5-
C5H5){η2-(E)-CHPhdCHCHdCH2}(PiPr3) (5).
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for th e Com p lex
OsH(η5-C5H5)(η2-(E)-P h CHdCHCHdCH2)(P iP r 3) (5)
Os-P
2.2887(8)
2.181(3)
2.148(3)
2.262(3)
2.270(3)
2.244(3)
2.245(3)
Os-C(15)
Os-H(01)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
C(4)-C(5)
2.242(3)
1.57(1)
1.312(5)
1.467(4)
1.436(4)
1.487(4)
Os-C(3)
Os-C(4)
Os-C(11)
Os-C(12)
Os-C(13)
Os-C(14)
M(1)a-Os-M(2)b
M(1)a-Os-P
127.53(14)
128.20(10)
115.1(9)
99.04(9)
97(1)
C(1)-C(2)-C(3)
C(2)-C(3)-C(4)
C(3)-C(4)-C(5)
127.4(3)
121.5(3)
124.2(3)
M(1)a-Os-H(01)
M(2)b-Os-P
M(2)b-Os-H(01)
P-Os-H(01)
74.3(12)
a,b
M(1) and M(2) represent the midpoints of the C(11)-C(15)
Cp ring and C(3)-C(4) double bond, respectively.
E-stereochemistry at the coordinated carbon-carbon
double bond with the phenyl group cisoid-syn disposed
to the hydride and the C(3)-H hydrogen atom cisoid-
syn disposed to the phosphine ligand.
The styryl moiety coordinates to the osmium atom in
an asymmetrical fashion with Os-C(3) and Os-C(4)
bond lengths of 2.181(3) and 2.148(3) Å, respectively.
These distances agree well with those found in other
osmium-olefin complexes (between 2.13 and 2.28 Å).13
Similarly, the olefinic bond distance C(3)-C(4) (1.436-
(4) Å) is within the range reported for transition-metal
olefin complexes (between 1.340 and 1.445 Å).14 As a
consequence of the contributions of the acceptor com-
ponent of the osmium-olefin bond to the structure of
the complex, the C(3)-C(4) bond length is about
0.12 Å longer than the C(1)-C(2) distance (1.312(5) Å),
corresponding to the noncoordinated carbon-carbon
double bond of the vinyl moiety. The separation be-
tween the styryl and vinyl fragments of the diene is
1.467(4) Å.
Figure 3 shows a view of the molecular geometry of
7, whereas selected bond distances and angles are listed
in Table 3. The coordination geometry around the
osmium atom can be rationalized as being derived from
a highly distorted octahedron with the cyclopentadienyl
ligand occupying a face. The structure proves the
formation of the allyl ligand, which is coordinated by
the C(1), C(2), and C(3) carbon atoms. The angles
C(1)-Os-C(3) and C(1)-C(2)-C(3) are 67.87(16)° and
118.3(4)°, respectively. The benzyl substituent is syn
disposed with regard to C(2), with a C(2)-C(3)-C(4)
angle of 117.7(4)°. The allyl moiety coordinates in an
asymmetrical fashion, with the separation between the
central carbon atom, C(2), and the metal (2.112(4) Å)
shorter than the separation between the metal and the
terminal carbon atoms C(1) (2.183(4) Å) and C(3) (2.193-
(13) (a) J onhson, T. J .; Albinati, A.; Koetzle, T. F.; Ricci, J .;
Eisenstein, O.; Huffman, J . C.; Caulton, K. G. Inorg. Chem. 1994, 33,
4966. (b) Edwards, A. J .; Esteruelas, M. A.; Lahoz, F. J .; Lo´pez, A. M.;
On˜ate, E.; Oro, L. A.; Tolosa, J . I. Organometallics 1997, 16, 1316. (c)
Edwards, A. J .; Elipe, S.; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.;
Valero, C. Organometallics 1997, 16, 3828. (d) Esteruelas, M. A.;
Garc´ıa-Yebra, C.; Oliva´n, M.; On˜ate, E. Organometallics 2000, 19,
3260.
(14) Allen, F. H.; Davies, J . E.; Galloy, J . J .; J ohnson, O.; Kennard,
O.; Macrae, C. F.; Mitchell, E. M.; Mitchell, G. F.; Smith, J . M.; Watson,
D. G. J . Chem. Inf. Comput. Sci. 1991, 31, 187.

Osmium-Carbene Complex
Organometallics, Vol. 22, No. 3, 2003 419
Sch em e 2
F igu r e 3. Molecular diagram of the complex Os(η5-
C5H5){η3-CH2CHCH(CH2Ph)}(PiPr3) (7).
Ta ble 3. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for th e Com p lex
Os(η5-C5H5){η3-CH2CHCH(CH2P h )}(P iP r 3) (7)
(η5-C5H5)(tCPh)(PiPr3)]BF4 (9a ). When the reaction is
carried out in a Schlenk-tube using diethyl ether as
solvent, the molar ratio is 1:1. The succesive recrystal-
lizations of the mixture from dichloromethane/diethyl
ether increase the amount of 9a .
Os-P
2.3124(11)
2.183(4)
2.112(4)
2.193(4)
2.182(4)
2.214(4)
Os-C(13)
Os-C(14)
Os-C(15)
C(1)-C(2)
C(2)-C(3)
C(3)-C(4)
C(4)-C(5)
2.219(4)
2.236(4)
2.228(4)
1.416(6)
1.429(6)
1.515(6)
1.510(5)
Os-C(1)
Os-C(2)
Os-C(3)
Os-C(11)
Os-C(12)
These observations can be rationalized according to
Scheme 2. The initial protonation of the carbene-carbon
atom of 2 affords 8, which eliminates HCl to give 9. The
higher polarity and/or basicity of diethyl ether with
regard to dichloromethane favors the loss of HCl and,
therefore, the formation of the hydride-carbyne deriva-
tive. The PF6-salt of 9 can be obtained by treatment of
acetone solutions of 2 with a stoichiometric amount of
thallium hexafluorophosphate, at room temperature. By
this procedure, complex 9b (Scheme 2) was obtained as
a yellow solid in 66% yield.
Ma-Os-P
124.86(14)
130.71(16)
124.04(16)
133.13(17)
93.20(13)
111.08(13)
93.01(12)
C(1)-Os-C(2)
C(1)-Os-C(3)
C(2)-Os-C(3)
C(1)-C(2)-C(3)
C(2)-C(3)-C(4)
C(3)-C(4)-C(5)
38.46(16)
67.87(16)
38.71(16)
118.3(4)
117.7(4)
110.3(3)
Ma-Os-C(1)
Ma-Os-C(2)
Ma-Os-C(3)
P-Os-C(1)
P-Os-C(2)
P-Os-C(3)
a
M represents the midpoint of the C(11)-C(15) Cp ring.
(4) Å). The carbon-carbon distances within the allylic
moiety are 1.416(6) Å for C(1)-C(2) and 1.429(6) Å for
C(2)-C(3). These values agree well with those found for
1
In the H NMR spectrum of the mixture, the -CH2-
3
and the osmium(IV) derivative [OsH(η5-C5H5)-
protons of the benzyl ligand of 8 display two resonances,
at 5.23 and 5.04 ppm. The first of them appears as a
doublet with a H-H coupling constant of 4.8 Hz, while
the second one is observed as a double doublet by spin
coupling with the phosphorus of the phosphine (11.2 Hz)
and the other CH2-hydrogen. The spin coupling between
one of the CH2-hydrogens and the phosphorus of the
phosphine suggests that in a four-legged piano-stool
arrangement of ligands around the osmium atom the
CH2 group is cisoid disposed to the phosphine. The
aromatic protons of the η3-benzyl ligand give rise to five
resonances at 8.49 (Hpara), 7.59 (both Hortho), 7.22 (Hmeta),
and 6.83 (Hmeta) ppm. In the 13C{1H} NMR spectrum,
the resonance due to the CH2-carbon of the benzyl
ligand is observed at 22.5 ppm as a doublet with a C-P
coupling constant of 26 Hz. The aromatic carbon atoms
of the benzyl ligand display singlets between 109 and
140 ppm. A singlet at -7.1 ppm in the 31P{1H} is also
characteristic of 8. These spectroscopic data are in
accordance with those reported previously for other
η3-benzyl complexes.16
{η3-CH2C(Ph)CH2}(PiPr3)]BF4.9j
In agreement with the structure shown in Figure 3,
1
the H NMR spectrum in benzene-d6 at room temper-
ature shows four resonances for the allylic protons at
3.73 (C(2)H), 2.83 (C(1)H syn to C(2)H), 1.44 (C(3)H),
and 0.73 (C(1)H anti to C(2)H) ppm. The different
coupling constants mixed up in these multiplets have
been deduced by means of the H{31P} NMR spectrum
1
1
and selective homonuclear irradiation in the H NMR
spectrum and are reported in the Experimental Section.
In the 13C{1H} NMR spectrum the most noticeable reso-
nances are a singlet at 52.8 ppm and two doublets at
36.0 and 11.0 ppm with a C-P coupling constant of 6
Hz, in both cases. On the basis of the H-13C HMQC
1
spectrum, these resonances are assigned to the C(2),
C(3), and C(1) atoms of the allyl ligand, respectively.
The 31P{1H} NMR spectrum contains a singlet at 21.9
ppm.
3. Reaction of Os(η5-C5H5)Cl(dCHP h )(P iP r 3) with
HBF 4. Although the reactions shown in Scheme 1 prove
the electrophilicity of the carbene-carbon atom of 2, it
must be pointed out that this atom also undergoes the
attack of electrophiles.15 The addition of 1.0 equiv of
HBF4‚OEt2 to an NMR tube containing a dichlo-
romethane-d2 solution of 2 leads to a 7:1 mixture of the
η3-benzyl complex [Os(η5-C5H5)(η3-CH2C6H5)Cl(PiPr3)]-
BF4 (8) and the hydride-carbyne derivative [OsH-
(15) We note that the complexes Ru(dCF2)(CO)2(PPh3)2, Re-
(C5H5)(dCHCH2CH2CMe3)(CO)2,
and
Re{dC(CH3)C(CH3)2CH2-
(η5-C5H4)}(CO)2 also show amphiphilic reactivity at the carbene carbon
atom. See: (a) Clark, G. R.; Hoskins, S. V.; J ones, T. C.; Roper, W. R.
J . Chem. Soc., Chem. Commun. 1983, 719. (b) Casey, C. P.; Vosejpka,
P. C.; Askham, F. R. J . Am. Chem. Soc. 1990, 112, 3713. (c) Casey, C.
P.; Czerwinski, C. J .; Powell, D. R.; Hayashi, R. K. J . Am. Chem. Soc.
1997, 119, 5750.

420 Organometallics, Vol. 22, No. 3, 2003
Esteruelas et al.
ruthenium derivatives, RuCl2(dCHR)(PR′3)2. To ratio-
nalize the higher stability of these saturated hydride-
carbyne species with regard to the unsaturated carbene
isomers, it can be argued that the migration of the
hydrogen from the carbene to the metal involves a
simple intramolecular oxidative addition. It is well-
known that this process is more favored for the 5d
metals than for the 4d ones.
The fact that the R-hydrogen migration in these
osmium systems leads to carbyne complexes where the
metal could be viewed as being in a high formal
oxidation state suggests that the carbyne ligand could
be considered as a trianionic group. So, the previously
mentioned hydride-carbyne complexes could be consid-
ered as osmium(VI) species. Thus, since the oxidative
addition process involves an increase in two units of the
oxidation state, the carbene precursors could be con-
sidered as osmium(IV) derivatives. This means that
complex 2 could be viewed as a triplet-state carbene spin
coupled to two electrons on the metal center. In other
words, complex 2 could be a Schrock-type carbene
derivative. This possibility prompted us to carry out the
reaction of 2 with sodium methoxide.
F igu r e 4. Molecular diagram of the cation of [OsH(η5-
C5H5)(tCPh)(PiPr3)]PF6 (9b).
Ta ble 4. Selected Bon d Dista n ces (Å)a a n d An gles
(d eg) for th e Com p lex
4. Reaction of Os(η5-C5H5)Cl(dCHP h )(P iP r 3) with
Sod iu m Meth oxid e. Treatment of tetrahydrofuran
solutions of 2 with sodium methoxide produces the de-
protonation of the carbene carbon atom and the forma-
tion of the neutral carbyne derivative Os(η5-C5H5)-
(tCPh)(PiPr3) (10), according to the reactivity expected
for a Schrock-type carbene compound (eq 4). Complex
10 can also be prepared as a dark purple solid in high
yield (about 77%) by addition of sodium methoxide to
the tetrahydrofuran solutions of the cationic hydride-
carbyne 9b (Scheme 3).
[OsH(η5-C5H5)(tC-P h )(P iP r 3)]P F 6 (9b)
Os-P(1)
Os-C(1)
Os-C(8)
Os-C(9)
2.347(2)
1.733(9)
2.328(9)
2.350(9)
Os-C(10)
Os-C(11)
Os-C(12)
C(1)-C(2)
2.253(8)
2.238(8)
2.249(8)
1.449(12)
Mb-Os-P(1)
Mb-Os-C(1)
Mb-Os-H(01)
P(1)-Os-C(1)
124.4(3)
135.9(4)
132(2)
92.5(3)
P(1)-Os-H(01)
C(1)-Os-H(01)
Os-C(1)-C(2)
79(3)
73(4)
176.9(7)
a
b
The Os-H(01) was fixed to 1.59(1) Å. M represents the
midpoint of the C(8)-C(12) Cp ring.
Figure 4 shows a view of the structure of the cation
of 9b. Table 4 collects selected bond distances and
angles. The coordination geometry around the metallic
center can be rationalized as being derived from a highly
distorted octahedron with the cyclopentadienyl ligand
occupying a face of the octahedron. The angle be-
tween the phosphine and carbyne ligand is close to
90° (C(1)-Os-P(1) ) 92.5(3)°). However the angles
C(1)-Os-H(01) (73(4)°) and P(1)-Os-H(01) (79(3)°)
strongly deviate from the ideal value of 90°. The very
short Os-C(1) bond length of 1.733(9) Å and the angle
Os-C(1)-C(2) of 176.9(7)° are fully consistent with an
Os-C(1) triple-bond formulation.17
1
The most noticeable feature in the H spectrum of 10
in benzene-d6 is the absence of any hydride resonance.
The 13C{1H} NMR spectrum displays at 262.0 a doublet
with a C-P coupling constant of 13.8 Hz due to the
C(sp) carbon of the carbyne ligand. The 31P{1H} NMR
spectrum contains a singlet at 53.5 ppm.
Complex 10 is soluble in hydrocarbon solvents. Its
solutions are stable for up to several days if kept
under argon. However, in methanol, it evolves into
the hydride-alkoxycarbene derivative OsH(η5-C5H5)-
{dC(OMe)Ph}(PiPr3) (11), as a consequence of the
addition of the O-H bond of the alcohol to the Os-C
triple bond of 10 (Scheme 3). Complex 11 can be
prepared in a one-pot synthesis by reaction of 2 with
KOH in methanol.
In agreement with the presence of a hydride ligand
in 9b, the IR spectrum in Nujol shows a ν(OsH)
1
absorption at 2129 cm-1. In the H NMR spectrum in
dichloromethane-d2 at room temperature, the hydride
ligand gives rise to a doublet at -11.94 ppm with a H-P
coupling constant of 24.0 Hz. In the 13C{1H} NMR
spectrum, the most noticeable resonance is a doublet
at 280.5 ppm, with a C-P coupling constant of 9 Hz,
corresponding to C(1). The 31P{1H} NMR spectrum
contains a singlet at 45.1 ppm and a septuplet at -146.2
ppm for the hexafluorophosphate anion.
The formation of 9a by means of the creation of a
coordination vacancy in 2 agrees well with the existence
of the hydride-carbyne derivatives OsHCl2(tCR)(PR′3)2.18
These bis(phosphine) complexes are isomers of the
unknown compounds OsCl2(dCHR)(PR′3)2, which should
be the osmium counterparts to the Grubbs-type carbene-
(16) See for example: (a) Lee, B. Y.; Bazan, G. C.; Vela, J .; Komon,
Z. J . A.; Bu, X. J . Am. Chem. Soc. 2001, 123, 5352. (b) Carmona, E.;
Paneque, M.; Poveda, M. L. Polyhedron 1989, 8, 285.
(17) Castarlenas, R.; Esteruelas, M. A.; On˜ate, E. Organometallics
2001, 20, 3283, and references therein.
(18) (a) Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Ruiz,
N. J . Am. Chem. Soc. 1993, 115, 4683. (b) Spivak, G. J .; Coalter, J . N.;
Oliva´n, M.; Eisenstein, O.; Caulton, K. G. Organometallics 1998, 17,
999. (c) Werner, H.; J ung, S.; Weberndo¨rfer, B.; Wolf, J . Eur. J . Inorg.
Chem. 1999, 951.

Osmium-Carbene Complex
Sch em e 3
Organometallics, Vol. 22, No. 3, 2003 421
F igu r e 5.
Molecular diagram of the complex
OsH(η5-C5H5){CH(Ph)OC6H4}(PiPr3) (12).
Complex 11 was isolated as a dark orange oil in
about 88% yield. The presence of a hydride ligand in
this complex is strongly supported by the 1H NMR
spectrum in benzene-d6 at room temperature, which
contains at -14.99 ppm a doublet with a H-P con-
stant of 32.1 Hz. In the low-field region of the spec-
trum, the most noticeable resonance is a singlet at
3.09 ppm, corresponding to the methoxy group. In
the 13C{1H} NMR spectrum the resonance due to
the CR atom of the carbene ligand appears at 242.6
ppm, as a doublet with a C-P coupling constant of 9
Hz. The 31P{1H} NMR spectrum shows a singlet at
46.5 ppm.
Ta ble 5. Selected Bon d Dista n ces (Å)a a n d An gles
(d eg) for th e Com p lex
OsH(η5-C5H5){CH(P h )OC6H4}(P iP r 3) (12)
Os-P
2.3228(14)
2.109(5)
2.159(6)
2.266(5)
2.220(5)
2.207(5)
Os-C(17)
Os-C(18)
O-C(2)
2.242(5)
2.296(6)
1.354(6)
1.435(6)
1.397(3)
Os-C(1)
Os-C(7)
Os-C(14)
Os-C(15)
Os-C(16)
O-C(7)
C(1)-C(2)
Mb-Os-P
129.62(18)
115.8(2)
125.7(2)
C(1)-Os-C(7)
C(1)-Os-H(01)
C(7)-Os-H(01)
Os-C(1)-C(2)
Os-C(7)-O
O-C(2)-C(1)
C(2)-O-C(7)
75.5(2)
126.8(17)
68.7(17)
115.8(4)
114.5(4)
118.6(5)
113.6(4)
Mb-Os-C(1)
Mb-Os-C(7)
Mb-Os-H(01)
P-Os-C(1)
P-Os-C(7)
P-Os-H(01)
116(2)
85.36(14)
103.10(15)
66.8(17)
Complex 10 also reacts with phenol. Treatment of
pentane solutions of 10 with 1.0 equiv of phenol at room
temperature affords the hydride, metallacyclic-osmium-
a
b
The Os-H(01) was fixed to 1.59(1) Å. M represents the
midpoint of the C(14)-C(18) Cp ring.
(IV) complex OsH(η5-C5H5){CH(Ph)OC6H4}(PiPr3) (12),
which was isolated as a yellow solid in about 66% yield
(eq 5).
sponding to the OsCH-hydrogen atom. The chemical
shift of the latter agrees with the reported one for the
related resonance of the ruthenium complex Ru(η5-C5H5)-
{9-phenyl-1,3-dihydronaphtho[2,3-c]-1-furanyl}(CO)-
(PiPr3) (7.50 ppm). These unusual chemical shifts seem
to be a consequence of the ring current effect of the
aromatic rings of these polycyclic systems.19 In the 13C-
{1H} NMR spectrum, the resonances corresponding to
the C(1) and C(7) carbon atoms are observed, at 172.7
and 67.3 ppm, as singlets. The 31P{1H} NMR spectrum
shows a singlet at 19.0 ppm.
The formation of 12 can be rationalized according to
Scheme 4. The initial addition of the O-H bond of
phenol to the Os-C triple bond of 10 should give the
hydride-alkoxycarbene intermediate 13, similar to that
isolated from the reaction of 10 with methanol (Scheme
3). The subsequent migration of the hydride ligand from
the metallic center to the CR atom of the carbene ligand
should afford the unsaturated species 14, which could
evolve into 12 by C-H activation of one of the ortho-
CH bonds of the OPh group.
Figure 5 shows a view of the structure of 12. Table
5 collects selected bond distances and angles. The
distribution of ligands around the osmium atom can
be described as a four-legged piano-stool geometry
with the carbon atom C(1) of the metalated phenyl
group disposed transoid to the hydride ligand. The
C(1)-Os-H(01) and C(7)-Os-P angles are 126.8(17)°
and 103.10(15)°, respectively.
The bidentate carbon donor ligand acts with a bite
angle of 75.5(2)°. The Os-C(1) and Os-C(7) bond
lengths are 2.109(5) and 2.159(6) Å, respectively. The
five-membered metallacycle shows an envelope confor-
mation with the osmium atom displaced by 0.217(8) Å
from the plane defined by the oxygen and the carbon
atoms.
Con clu d in g Rem a r k s
This paper reports the preparation and reactivity of
the osmium-carbene complex Os(η5-C5H5)(dCHPh)Cl-
(PiPr3), which shows a Fischer-Schrock ambivalent
behavior.
In agreement with the presence of a hydride ligand
in 12, the 1H NMR spectrum of this compound in
benzene-d6 at room temperature contains at -13.94
ppm a doublet with a H-P coupling constant of 41.1
Hz. In the low-field region of the spectrum, the most
noticeable resonance is a singlet at 8.36 ppm, corre-
(19) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; Oliva´n, M.;
On˜ate, E.; Ruiz, N. Organometallics 2000, 19, 4.

422 Organometallics, Vol. 22, No. 3, 2003
Esteruelas et al.
constants, J , are given in hertz. MS data were recorded on a
VG Austospec double-focusing mass spectrometer operating
in the positive mode; ions were produced with the Cs+ gun at
ca. kV, and 3-nitrobenzyl alcohol (NBA) was used.
Sch em e 4
P r ep a r a t ion of Os(η5-C5H5)Cl(dCHP h )(P iP r 3) (2). An
orange solution of 1 (300 mg, 0.49 mmol) in 4 mL of toluene
was treated with 12.5 mL of a red solution of N2dCHPh in
toluene (0.078 M, 1.96 mmol). The reaction mixture was
allowed to react at room temperature for 4 h, and the solvent
was removed. Then, 15 mL of pentane was added and the
solution was filtered through Kieselguhr. The resultant green
solution was concentrated to about 5 mL and was kept at -50
°C for 1.5 h. The dark blue solid formed was washed twice
with 2 mL of cold pentane and, finally, dried in vacuo. Yield:
175 mg (66%). Anal. Calcd for C21H32ClOsP: C, 46.64; H, 5.92.
1
Found: C, 46.84; H, 5.97. H NMR (C6D6, 293 K): δ 19.17 (d,
J H-P ) 12.9, 1H, OsdCHPh), 7.93 (d, J H-H ) 7.4, 2H, o-Ph),
7.39 (t, J H-H ) 7.4, 1H, p-Ph), 7.15 (vt, J H-H ) 7.4, 2H, m-Ph),
4.96 (s, 5H, C5H5), 2.56 (m, 3H, PCH), 1.05 (dd, J H-P ) 12.9,
J H-H ) 7.2, 9H, PCHCH3), 0.97 (dd, J H-P ) 13.2, J H-H
)
7.2, 9H, PCHCH3). 31P{1H} NMR (C6D6, 293 K): δ 20.7 (s).
13C{1H} NMR (C6D6, 293 K): δ 235 (br, OsdC), 167.7 (s,
As it should be expected for a Fischer-type carbene
derivative, the complex Os(η5-C5H5)(dCHPh)Cl(PiPr3)
reacts with phenyllithium, methyllithium, and allyl-
magnesium chloride to afford carbene-plus-organic frag-
ment coupling products. As a result, the benzoallyl
complex 3, the hydride-styrene derivative 4, and the
compounds hydride-η2-butadiene 5 and allyl 7 have been
obtained and characterized.
C
ipsoPh), 130.2, 126.5, and 125.7 (all s, Ph), 85.1 (s, Cp), 25.2
(d, J C-P ) 27, PCH), 20.1 and 19.6 (both s, PCHCH3).
P r ep a r a tion of Os(η5-C5H5)(η3-CHP h C6H5)(P iP r 3) (3). A
bluish green solution of 2 (100 mg, 0.18 mmol) in tetrahydro-
furan at 0 °C was treated with phenyllithium (103 µL, 0.18
mmol, 1.8 M in cyclohexane/diethyl ether, 70:30). The solution
became orange immediately, and after 30 min, the solvent was
removed. The product was extracted with 20 mL of pentane,
which was filtered through Kieselguhr. The solution was
concentrated to dryness, and an orange solid was obtained.
Pentane was added (2 mL), and the solution was stirred at 0
°C for 30 min, until an orange solid precipitated. It was
separated by decantation and dried in vacuo. Yield: 70 mg
(65%). Anal. Calcd for C27H37OsP: C, 55.64; H, 6.40. Found:
The behavior of Os(η5-C5H5)(dCHPh)Cl(PiPr3) as a
Schrock-type carbene complex is supported by three
reactions: (i) the formation of the benzoallyl derivative
8 as a consequence of the protonation of the carbene
ligand with HBF4, (ii) the formation of the hydride-
carbyne 9 by extraction of the chlorine ligand and
migration of the hydrogen-carbene atom from the car-
bene-carbon atom to the metallic center, and (iii) the
deprotonation of the carbene to give the five-coordinate
carbyne 10.
It is assumed that the Fischer or Schrock character
of a carbene derivative depends on the ground state of
the carbene ligand in its coordination to the metal
(singlet or triplet). So, according to the results reported
here, it must be assumed that there is a class of carbene
derivatives without heteroatom substituents, for which
both modes of coordination are accessible under the
usual experimental conditions.
C, 56.10; H, 6.38. IR (Nujol, cm-1): ν(Ph) 1594 (m). H NMR
(CD2Cl2, 233 K): δ 7.37 (d, J H-H ) 7.3, 2H, o-Ph), 7.23 (t, J H-H
) 7.3, 2H, m-Ph), 7.13 (t, J H-H ) 7.3, 1H, p-Ph), 6.98 (m, 2H,
H9-H12), 6.38 (m, 2H, H10-H11), 3.99 (s, 5H, C5H5), 3.86 (dd,
J H-P ) 14.4, J H
(d, J H-P ) 14.1, 1H, CHPh2), 1.22 (dd, J H-P ) 12.3, J H-H
7.2, 9H, PCHCH3), 1.18 (dd, J H-P ) 12.3, J H-H ) 7.2, 9H,
PCHCH3). 31P{1H} NMR (CD2Cl2, 233 K): δ 15.3 (s). 13C{1H}
NMR (CD2Cl2, 233 K): δ 148.6 (s, CipsoPh), 142 (s, C9 or C12),
131.1 (s, o-Ph), 129.3 (s, C9 or C12), 128.2 (s, m-Ph), 124.6 (s,
C10 or C11), 124 (s, p-Ph), 116.8 (s, C10 or C11), 78.2 (s, C8), 74.7
(s, Cp), 40.7 (d, J C-P ) 4, C13), 33.4 (d, J C-P ) 7, -CHPh2),
26.4 (br, PCH), 20.5 (s, PCHCH3), 20.3 (s, PCHCH3). 1H NMR
(CD2Cl2, 293 K): δ 7.6-6.2 (br, Ph), 3.99 (s, 5H, C5H5), 2.20
(m, 3H, PCH), 1.84 (br d, J H-P ) 14.1, 1H, CHPh2), 1.20 (dd,
J H-P ) 12, J H-H ) 7, 18H, PCHCH3).
1
) 5.6, 1H, H13), 2.13 (m, 3H, PCH), 1.84
12
13
-H
)
The chemistry of this type of species and their
derivatives is very versatile. This study reveals that
complex Os(η5-C5H5)(dCHPh)Cl(PiPr3), in addition to
affording carbon-carbon coupling reactions and inter-
esting carbyne derivatives, provides access to the novel
hydride-alkoxycarbene compound 11 and the hydride-
heterometallacycle species 12.
Exp er im en ta l Section
P r ep a r a tion of OsH(η5-C5H5)(CH2dCHP h )(P iP r 3) (4). A
bluish green solution of 2 (110 mg, 0.20 mmol) in tetrahydro-
furan at 0 °C was treated with methyllithium (127 µL, 0.20
mmol, 1.6 M in diethyl ether). Immediately, the reaction
mixture became brown. It was allowed to react at 0 °C for 45
min. Then, the solvent was removed, and the resultant oil was
extracted in toluene and filtered through Kieselguhr. The
toluene solution was dried in vacuo, and a dark brown oil was
obtained. Yield: 79.4 mg (75%). IR (Nujol, cm-1): ν(OsH) 2107
(w), ν(Ph) 1599 (m). 1H NMR (CD2Cl2, 263 K): δ 7.13 (vt, J H-H
) 7.6, 2H, m-Ph), 7.01 (d, J H-H ) 7.6, 2H, o-Ph), 6.87 (t, J H-H
) 7.6, 1H, p-Ph), 4.53 (s, 5H, C5H5), 3.18 (ddd, J H-P ) 8.3,
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
9a
starting materials Os(η 5-C5H5)Cl(PiPr3)2 (1) and N2dCHPh20
were prepared by the published methods.
NMR spectra were recorded on a Varian Unity, a Varian
Geminy 2000, and a Bruker ARX 300 MHz instrument. 1H
(300 MHz) and 13C (75.19 MHz) NMR chemical shifts were
referenced to TMS by using known shifts of residual proton
or carbon signals in the solvents. 31P (121 MHz) NMR were
measured relative to external 85% phosphoric acid. Coupling

Osmium-Carbene Complex
Organometallics, Vol. 22, No. 3, 2003 423
J H-Htrans ) 9.0, J H-Hcis ) 7.6, 1H, CHPh), 2.60 (dd, J H-Htrans
)
P r ep a r a t ion of Os(η5-C5H 5){η3-CH 2CH CH (CH 2P h )}-
(P iP r 3) (7). A yellow solution of 5 (100 mg, 0.18 mmol) in 5
mL of toluene was heated at 60 °C for 6 h. After the sample
was cooled to room temperature, the yellow solution obtained
was concentrated to dryness and MeOH was added (about 2
mL). A white solid was obtained, and the suspension was
stored at -78 °C for 30 min. The solid was separated by
decantation, washed with cold MeOH, and dried in vacuo.
Yield: 90 mg (90%). Anal. Calcd for C24H37OsP: C, 52.72; H,
6.82. Found: C, 52.51; H, 6.38. 1H NMR (C6D6, 293 K): δ 7.50
(d, J H-H ) 7.5, 2H, o-Ph), 7.29 (t, J H-H ) 7.5, 2H, m-Ph), 6.99
(t, J H-H ) 7.5, 1H, p-Ph), 4.55 (s, 5H, C5H5), 3.73 (dddd,
9.0, J Hcis-Htrans ) 3.2, 1H, CHHtrans), 2.14 (m, 3H, PCH), 2.00
(ddd, J Hcis-Htrans ) 3.2, J H-Hcis ) 7.6, J Hcis-Hhyd ) 3.9, 1H,
CHHcis), 1.20 (dd, J H-P ) 13.3, J H-H ) 7.2, 9H, PCHCH3), 1.11
(dd, J H-P ) 12, J H-H ) 7.1, 9H, PCHCH3), -16.30 (dd, J H-P
)
33.6, J H-H ) 3.9, 1H, Os-H). 31P{1H} NMR (CD2Cl2, 263 K):
δ 31.4 (s). 13C{1H} NMR (CD2Cl2, 263 K): δ 153.9 (s, CipsoPh),
128.1 and 125.1 (both s, Ph), 122.7 (s, p-Ph), 80.1 (s, Cp), 28.4
(d, J C-P ) 28, PCH), 21.5 (s, PCHCH3), 20.5 (s, CHPh), 19.9
(s, PCHCH3) 1.28 (s, CH2). MS (FAB+): m/z 522 (M+ + H).
) 8.3, J H-P ) 3.6, 1H, H2),
-H
1syn 2
1syn
2
1anti
2
2
3
J H
) 6.0, J H
) J H
-H
-H
3.32 (dd, J gem ) 14.4, J H-H ) 3, 1H, -CH2Ph), 2.83 (dd, J H
-H
1syn
1anti
) 6.0, J H
) 9.9, 1H, -CH2Ph), 1.74 (m, 3H, PCH), 1.44 (m, 1H, H3), 0.98
(dd, J H-P ) 12.0, J H-H ) 7.0, 9H, PCHCH3), 0.97 (dd, J H-P
12.0, J H-H ) 7.1, 9H, PCHCH3), 0.73 (ddd, J H-P ) 14.0,
) 1.8, 1H, H1syn), 2.73 (dd, J gem ) 14.4, J H-H
-H
)
P r ep a r a t ion of OsH(η5-C5H5){η2-(E)-CHP h dCHCHd
CH2}(P iP r 3) (5). A bluish green solution of 2 (100 mg, 0.18
mmol) in 5 mL of tetrahydrofuran at 0 °C was treated with
allylmagnesium chloride (92.4 µL, 0.18 mmol, 2 M in tetrahy-
drofuran). The solution was stirred for 1 h, after which it
became brown. The solvent was removed. The product was
extracted with 20 mL of pentane, and the solution was filtered
through Kieselguhr. The resultant yellow solution was con-
centrated to 2 mL, and a pale yellow solid was obtained. The
solid was separated by decantation and dried in vacuo. Yield:
75.8 mg (75%). Anal. Calcd for C24H37OsP: C, 52.72; H, 6.82.
Found: C, 52.97; H, 6.79. IR (Nujol, cm-1): ν(OsH) 2111 (w),
J H
) 8.3, J H
) 1.8, 1H, H1anti). 31P{1H} NMR
1anti
2
1syn
1anti
-H
-H
(C6D6, 293 K): δ 21.9 (s). 13C{1H} NMR (C6D6, 293 K): δ 146.3
(s, CipsoPh), 128.5, 128.5, and 125.6 (all s, Ph), 72 (s, Cp), 52.8
(s, C2), 46.8 (s, -CH2Ph), 36.0 (d, J C-P ) 6, C3), 27.0 (d, J C-P
) 25, PCH), 20.4 and 20.0 (both s, PCHCH3), 11.0 (d, J C-P
)
6, C1).
1
ν(Ph) 1610 (m). H NMR (C6D6, 293 K): δ 7.53 (d, J H-H ) 7.5,
2H, o-Ph), 7.12 (vt, J H-H ) 7.5, 2H, m-Ph), 6.97 (t, J H-H ) 7.5,
Rea ction of 2 w ith HBF 4. A bluish green solution of 2 (13
mg, 0.02 mmol) in dichloromethane-d2 (0.4 mL) was treated
with a tetrafluoroboric acid/diethyl ether complex (3.2 µL, 0.02
mmol). Immediately, the solution became dark red. After 2 min
at room temperature, the NMR spectra showed the presence
of [Os(η5-C5H5)Cl(η3-CH2C6H5)(PiPr3)]BF4 (8) and [OsH(η5-
C5H5)(tCPh)(PiPr3)]BF4 (9a ) in a molar ratio 7:1. Spectroscopic
data for 8: 1H NMR (CD2Cl2), 293 K): δ 8.49 (vt, J H-H ) 7.8,
1H, H4), 7.59 (d, J H-H ) 7.8, 1H, H2), 7.59 (d, J H-H ) 7.8, 1H,
H6), 7.22 (vt, J H-H ) 7.8, 1H, H3), 6.83 (vt, J H-H ) 7.8, 1H,
H5), 6.29 (s, 5H, C5H5), 5.23 (d, J H-H ) 4.8, 1H, -CH2-allyl),
5.04 (dd, J H-P ) 11.2, J H-H ) 4.8, 1H, -CH2-allyl), 2.71 (m,
3H, PCH), 1.38 (dd, J H-P ) 12.9, J H-H ) 7.2, 9H, PCHCH3),
1.16 (dd, J H-P ) 13.2, J H-H ) 7.2, 9H, PCHCH3). 31P{1H} NMR
2
3
2
1B
2
1A
1H, p-Ph), 5.78 (ddd, J H
) 9.3, J H
) 10.2, J H
-H
)
-H
1A
-H
1A
16.8, 1H, H2), 5.14 (dd, J H
) 2.1, J H
) 16.8, 1H, H1A),
-H
1B
2
-H
1B
1A
1B
2
4.79 (dd, J H
) 2.1, J H
) 10.2, 1H, H1B), 4.71 (s, 5H,
-H
-H
4
4
3
3
2
3
4
C5H5), 4.70 (d, J H
) 9.3, 1H, H ), 3.33 (ddd, J H
) J H
-H -H
-H
) J H
) 9.3, 1H, H3), 1.65 (m, 3H, PCH), 1.02 (dd, J H-P
)
)
3
-P
12.6, J H-H ) 7.5, 9H, PCHCH3), 0.65 (dd, J H-P ) 12.9, J H-H
7.2, 9H, PCHCH3), -16.06 (d, J H-P ) 35.1, 1H, Os-H). 31P{1H}
NMR (C6D6, 293 K): δ 31.9 (s). 13C{1H} NMR (C6D6, 293 K):
δ 153.5 (s, CipsoPh), 151.8 (s, C2), 130.7, 127, 124.3 (all s, Ph),
103.9 (s, C1), 80.4 (s, Cp), 29.6 (d, J C-P ) 28, PCH), 24.3 (d,
J C-P ) 2, C4), 23.4 (d, J C-P ) 5, C3), 20.4 and 19.4 (both s,
PCHCH3).
(C6D6, 293 K): δ -7.1 (s). 13C{1H} NMR (CD2Cl2, 293 K):21
δ
139.8 (s, C4), 136.5 (s, C3), 134.3 (s, C2 or C6), 130.5 (s, C5),
109.9 (s, C2 or C6), 89.5 (s, Cp), 27.1 (d, J C-P ) 25, PCH), 22.5
(d, J C-P ) 26, -CH2-allyl), 20.9 and 20.1 (both s, PCHCH3).
P r ep a r a tion of Os(η5-C5H5)(CHP h 2)(CO)(P iP r 3) (6). An
orange solution of 3 (100 mg, 0.17 mmol) in 5 mL of dichlo-
romethane was stirred under 1 atm of CO for 4 h, at room
temperature. The resultant light yellow solution was concen-
trated to dryness, pentane was added (2 mL), and a white solid
precipitated. The solid was separated by decantation and dried
in vacuo. Yield: 76 mg (73%). Anal. Calcd for C28H37OOsP:
P r ep a r a tion of [OsH(η5-C5H5)(tCP h )(P iP r 3)]P F 6 (9b).
An orange solution of 1 (300 mg, 0.49 mmol) in 4 mL of toluene
was treated with 12.5 mL of a red solution of N2dCHPh in
toluene (0.078 M, 1.96 mmol). The reaction mixture was
allowed to react at room temperature for 4 h. The solvent was
removed in vacuo, and the resultant green oil was treated with
6 mL of acetone and 171 mg (0.49 mmol) of thallium(I)
hexafluorophosphate. The resulting mixture was stirred for
15 min in the absence of light, during which it became brown.
The suspension was filtered through Kieselguhr. The resultant
solution was concentrated to ca. 1 mL and cooled to 0 °C.
Diethyl ether was added (15 mL) and 30 min later, a yellow
C, 55.07; H, 6.11. Found: C, 54.85; H, 6.03. IR (Nujol, cm-1):
1
ν(CtO) 1895 (vs). H NMR (C6D6, 293 K): δ 7.54 (d, J H-H
7.6, 2H, o-Ph), 7.29 (d, J H-H ) 7.6, 2H, o-Ph), 7.21 (vt, J H-H
)
)
7.6, 2H, m-Ph), 7.13 (vt, J H-H ) 7.6, 2H, m-Ph), 6.97 (t, J H-H
) 7.6, 1H, p-Ph), 6.91 (t, J H-H ) 7.6, 1H, p-Ph), 5.35 (d, J H-P
) 3.5, -CHPh2), 4.63 (s, 5H, C5H5), 2.10 (m, 3H, PCH), 0.94
(dd, J H-P ) 13.7, J H-H ) 7.2, 9H, PCHCH3), 0.71 (dd, J H-P
)
12.8, J H-H ) 7.1, 9H, PCHCH3). 31P{1H} NMR (C6D6, 293 K):
δ 16.9 (s). 13C{1H} NMR (C6D6, 293 K): δ 189.2 (d, J C-P ) 13,
CO), 159.3 (s, CipsoPh), 155.3 (s, CipsoPh), 131, 123.6, 122.6 (all
s, Ph), 82.9 (s, Cp), 27.2 (d, J C-P ) 28, PCH), 20.2 and 19.1 (s,
PCHCH3), 10.0 (d, J C-P ) 5, -CHPh2).
(20) J ime´nez, A. I.; Lo´pez, P.; Oliveros, L.; Cativiela, C. Tetrahedron
2001, 57, 6019.
(21) The resonance due to C(1) was not observed.

424 Organometallics, Vol. 22, No. 3, 2003
Esteruelas et al.
Ta ble 6. Cr ysta l Da ta a n d Da ta Collection a n d Refin em en t for 3, 5, 7, 9b, a n d 12
3
5
7
9b
12
Crystal Data
formula
molecular wt
color and habit
C
27H37OsP
C24H37OsP
546.71
yellow, irregular
block
C24H37OsP
546.71
needle, irregular
block
C21H32F6OsP2‚0.5H2O C27H37OOsP
582.74
orange, irregular
block
659.61
598.74
yellow, irregular
block
yellow, irregular
block
size, mm
symmetry, space
group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
0.18,0.18,0.08
monoclinic, P21/c
0.20,0.18,0.16
triclinic, P1h
0.12,0.06,0.06
orthorhombic, P212121 monoclinic, P2/c
0.30,0.30,0.06
0.12,0.08,0.07
monoclinic, P21/c
9.1858(6)
14.2596(10)
18.4529(13)
9.1744(5)
10.8883(6)
11.1237(6)
97.945(1)
93.635(1)
94.429(1)
1094.14(10)
2
7.6276(4)
9.6814(5)
29.1843(15)
14.3655(16)
9.3630(10)
18.247(2)
10.7954(8)
13.0172(10)
16.8056(12)
102.582(2)
101.232(2)
93.673(1)
2359.0(3)
4
1.641
2155.14(19)
4
1.685
2407.3(5)
4
1.822
2356.8(3)
4
1.682
Z
D
calc, g cm-3
1.659
Data Collection and Refinement
diffractometer
λ(Mo KR), Å
monochromator
scan type
Bruker Smart APEX
0.71073
graphite oriented
ω scans
6.00
µ, mm-1
5.48
3, 57
100.0(2)
21596
5.91
3, 57
100.0(2)
13436
5.49
5.50
2θ, range deg
temp, K
no. of data collect
3, 57
100.0(2)
28479
3, 57
3, 57
173.0(2)
15246
100.0(2)
21483
no. of unique data 5584 (Rint ) 0.0501) 5094 (Rint ) 0.037) 5185 (Rint ) 0.068)
5690 (Rint ) 0.0461)
285/10
5608 (Rint ) 0.0520)
256/0
no. of params/
restraints
274/0
265/1
260/0
Flack param
R1a [F2 > 2σ(F2)]
wR2b [all data]
Sc [all data]
0.162(6)
0.0242
0.0382
0.841
0.0282
0.0433
0.776
0.0228
0.0423
0.933
0.0546
0.1319
1.038
0.0354
0.0611
0.814
R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. wR2(F2) ) {∑[w(Fo2 - Fc2)2]/∑[w(Fo2)2]}1/2
.
c Goof ) S ) {∑[Fo2 - Fc2)2]/(n - p)}1/2, where n is the number
a
b
of reflections, and p is the number of refined parameters.
solid appeared, which was separated by decantation, washed
with 2 mL of tetrahydrofuran, and dried in vacuo. Yield: 210
mg (66%). Anal. Calcd for C21H32F6OsP2: C, 38.77; H, 4.96.
Found: C, 38.65; H, 4.90. IR (Nujol, cm-1): ν(OsH) 2129 (w),
P r epar ation of OsH(η5-C5H5){dC(OCH3)P h }(P iP r 3) (11).
An orange solution of 10 (150 mg, 0.23 mmol) in 5 mL of
methanol was stirred for 1 h at room temperature and filtered
through Kieselguhr. The solution was concentrated to dryness,
and the product was isolated as a dark orange oil. Yield: 140
1
ν(Ph) 1586 (m), ν(PF6) 845 (vs). H NMR (CD2Cl2, 293 K): δ
1
7.86 (tt, J H-H ) 7.6, J H-H ) 1.3, 1H, p-Ph), 7.79 (dd, J H-H
)
mg (88%). H NMR (C6D6, 293 K): δ 7.17 (d, J H-H ) 7.2, 2H,
7.6, J H-H ) 1.3, 2H, o-Ph), 7.47 (vt, J H-H ) 7.6, 2H, m-Ph),
5.86 (s, 5H, C5H5), 2.15 (m, 3H, PCH), 1.29 (dd, J H-P ) 10.2,
J H-H ) 7.2, 9H, PCHCH3), 1.24 (dd, J H-P ) 10.2, J H-H ) 7.2,
9H, PCHCH3), -11.94 (d, J H-P ) 24.0, 1H, Os-H). 31P{1H}
NMR (CD2Cl2, 293 K): δ -146.2 (sept, J F-P ) 714, PF6), 45.1
(s, PiPr3). 13C{1H} NMR (CD2Cl2, 293 K): δ 280.5 (d, J C-P ) 9,
OstC), 145.6 (s, CipsoPh), 135.1, 132, and 129.6 (all s, Ph), 88.5
(s, Cp), 30.1 (d, J C-P ) 33, PCH), 20.1 and 19.6 (both s,
PCHCH3).
o-Ph), 7.04 (vt, J H-H ) 7.2, 2H, m-Ph), 6.95 (t, J H-H ) 7.5, 1H,
p-Ph), 4.82 (s, 5H, C5H5), 3.09 (s, 3H, -OCH3), 2.03 (m, 3H,
PCH), 1.17 (dd, J H-P ) 12.9, J H-H ) 7.2, 9H, PCHCH3), 1.12
(dd, J H-P ) 12.9, J H-H ) 7.2, 9H, PCHCH3), -14.99 (d, J H-P
)
32.1, 1H, Os-H). 31P{1H} NMR (C6D6, 293 K): δ 46.5 (s).
13C{1H} NMR (C6D6, 293 K): δ 242.6 (d, J C-P ) 9, OsdC), 160.4
(s, CipsoPh), 126.6, 125.5, and 122.5 (all s, Ph), 83 (s, Cp), 57.2
(s, -OCH3), 28.8 (d, J C-P ) 27.3, PCH), 20.1 and 19.8 (both s,
PCHCH3). MS (FAB+): m/z 538 (M+ + H), m/z 507 (M+ + H -
OCH3).
P r ep a r a tion of Os(η5-C5H5)(tCP h )(P iP r 3) (10). A slurry
of 9b (240 mg, 0.37 mmol) in 7 mL of tetrahydrofuran was
treated with 20 mg (0.37 mmol) of sodium methoxide. The
mixture was stirred for 12 h at room temperature. The
resulting dark brown solution was concentrated to dryness.
The product was extracted with 20 mL of pentane, which was
filtered through Kieselguhr. The resulting dark purple solution
was concentrated to about 1 mL and cooled to -78 °C, and a
dark purple precipitate was obtained. The solid was sepa-
rated by decantation and dried in vacuo. Yield: 144 mg
(77%). Anal. Calcd for C21H31OsP: C, 49.98; H, 6.19. Found:
P r epar ation of OsH(η5-C5H5){CH(P h )OC6H4}(P iP r 3) (12).
A deep purple solution of 10 (140 mg, 0.28 mmol) in pentane
was treated with phenol (26 mg, 0.28 mmol). The sample was
stirred at room temperature for 12 h. The resultant light
orange solution was filtered through Kieselguhr and concen-
trated to 2 mL. A yellow solid was obtained. The solid was
separated by decantation, and cold pentane was added (1 mL).
The suspension was stored at -78 °C for 20 min. The yellow
solid was separated by decantation and dried in vacuo. Yield:
110 mg (66%). Anal. Calcd for C27H37OOsP: C, 54.16; H, 6.23.
1
C, 50.37; H, 5.87. IR (Nujol, cm-1): ν(Ph) 1583 (m). H NMR
1
Found: C, 54.07; H, 6.06. H NMR (C6D6, 293 K): δ 8.36 (s,
(C6D6, 293 K): δ 7.85 (m, 2H, o-Ph), 7.11 (tt, J H-H ) 7.5, J H-H
) 1.2, 1H, p-Ph), 6.88 (vt, J H-H ) 7.5, 2H, m-Ph), 4.83 (s,
1H, OsCH), 7.45 (d, J H-H ) 7.5, 2H, o-Ph), 7.22 (vt, J H-H
)
7.5, 2H, m-Ph), 7.1 (m, 1H, Ph), 7.04 (vt, J H-H ) 7.5, 1H, Ph),
6.91 (vt, J H-H ) 7.5, 1H, Ph), 6.78 (vt, J H-H ) 7.5, 1H, Ph),
6.64 (d, J H-H ) 7.5, 1H, Ph), 4.34 (s, 5H, C5H5), 2.12 (m, 3H,
PCH), 0.79 (dd, J H-P ) 14.4, J H-H ) 7.2, 9H, PCHCH3), 0.75
5H, C5H5), 1.69 (m, 3H, PCH), 1.17 (dd, J H-P ) 14, J H-H
)
6.9, 18H, PCHCH3). 31P{1H} NMR (C6D6, 293 K): δ 53.5 (s).
13C{1H} NMR (C6D6, 293 K): δ 262.0 (d, J C-P ) 14, OstC),
150.4 (s, CipsoPh), 129.5, 128.9, and 127.6 (all s, Ph), 76.4 (s,
Cp), 30.9 (d, J C-P ) 29, PCH), 20.7 (s, PCHCH3). MS (FAB+):
m/z 505 (M+).
(dd, J H-P ) 15.9, J H-H ) 7.2, 9H, PCHCH3), -13.94 (d, J H-P
)
41.1, 1H, Os-H). 31P{1H} NMR (C6D6, 293 K): δ 19.0 (s).

Osmium-Carbene Complex
Organometallics, Vol. 22, No. 3, 2003 425
13C{1H} NMR (C6D6, 293 K): δ 172.7 (s, Os-Csp2), 159.8 (s,
were unsuccessful and the distance Os-H was fixed to 1.59-
(1) Å.24 The rest of the hydrogen atoms were calculated and
refined using a restricted riding mode. All the highest elec-
tronic residuals were observed in close proximity of the Os
centers and make no chemical sense.
C
ipsoPh) 143.8, 129.7, 125.6, 124.2, 123.4, and 118.7 (all s, Ph),
115.8 (s, CipsoPh), 107 (s, Ph), 84.7 (s, Cp), 67.3 (s, Os-Csp3),
26.6 (d, J C-P ) 29, PCH), 20 and 19.2 (both s, PCHCH3).
Str u ctu r a l An a lysis of Com p lexes 3, 5, 7, 9b, a n d 12.
X-ray data were collected for all complexes at low temperature
on a Bruker Smart Apex CCD diffractometer with graphite-
monochromated Mo KR radiation (λ ) 0.71073 Å) using ω
scans. Data were corrected for absorption by using a multi-
scan method applied with the SADABS program.22 The
structures for all five compounds were solved by the Patterson
method. Refinement, by full-matrix least squares on F2 with
SHELXL97,23 was similar for all complexes, including isotropic
and subsequently anisotropic displacement parameters for all
non-hydrogen nondisordered atoms. The hydrogens attached
to carbon atoms bonded directly to Os metals were observed
in the difference maps and refined as free isotropic atoms in
the last cycles of refinement. The hydride ligand of 5 was
located and refined freely, but in 9b and 12 these refinements
Ack n ow led gm en t. We acknowledge financial sup-
port from the DGES of Spain (Proyect BQU2002-00606).
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 3, 5, 7, 9b,
and 12. This material is available free of charge via the
Internet at http://pubs.acs.org.
OM0208826
(23) SHELXTL Package v. 6.10; Bruker-AXS: Madison, WI, 2000.
Sheldrick, G. M. SHELXS-86 and SHELXL-97; University of Go¨ttin-
gen: Go¨ttingen, Germany, 1997.
(24) 3D Search and Research Using the Cambridge Structural
Database. Allen, F. H.; Kennard, O. Chem. Des. Autom. News 1993, 8
(1), 1, 31-37.
(22) Blessing, R. H. Acta Crystallogr. 1995, A51, 33-38. SADABS:
Area-detector absorption correction; Bruker-AXS: Madison, WI, 1996.