Meyer's complex OsH2Cl2(PiPr3)2 as a precursor for the preparation of new cyclopentadienylosmium compounds

Article abstract of DOI:10.1021/om970237c

The six-coordinate complex OsH₂Cl₂(PⁱPr₃)₂ (1) reacts with cyclopentadienylthallium to give Os(η⁵-C₅H₅)Cl(PⁱPr ₃)₂ (2). In methanol and acetone, 2 dissociates the chlorine ligand and the resulting metallic fragment is capable of activating a methyl C-H bond of a triisopropylphosphine to afford [OsH(η⁵-C₅H₅){CH₂CH(CH ₃)PⁱPr₂}(PⁱPr₃)] ⁺ (3), which can be isolated as the PF₆ salt by addition of either NaPF₆ or TIPF₆. Treatment of a 1:10 mixture of 2 and NaBH₄ in toluene with 1.0 mL of methanol affords OsH(η⁵-C₅H₅)(PⁱPr ₃)₂ (4), which by protonation with HBF₄·OEt₂ yields [OsH₂(η⁵-C₅H₅)(P ⁱPr₃)₂]BF₄ (5). In pentane, complex 2 reacts with trimethyl phosphite to give Os(η⁵-C₅H₅)Cl{P(OMe)₃}(P ⁱPr₃) (6). Similarly, the addition of methyl vinyl ketone and dimethyl acetylenedicarboxylate to toluene solutions of 2 produces the displacement of a phosphine ligand from 2 and the formation of Os(η⁵-C₅H₅)Cl{η²-CH ₂=CHC(O)CH₃}(PⁱPr₃) (7) and Os(η⁵-C₅H₅)Cl{η²-C(CO ₂CH₃)≡CCO₂CH₃}(P ⁱ-Pr₃) (8), respectively. Complex 2 also reacts with ethyl diazoacetate to give Os(η⁵-C₅H₅)Cl{η ²-(Z)-CH(CO₂C₂H₅)=CHCO ₂C₂H₅}(PⁱPr₃) (9) and with 1-ethynyl-1-cyclohexanol and 2-methyl-3-butyn-2-ol to afford Os(η⁵-C₅H₅)Cl{η ²-HC≡C-C(OH)(CH₂)₄CH₂}(P ⁱPr₃) (10) and Os(η⁵-C₅H₅)Cl{η ²-HC≡C-C(OH)(CH₃)₂}(PⁱPr ₃) (11). In toluene at 85 °C, complexes 10 and 11 evolve to the corresponding alkenylvinylidene derivatives Os(η⁵-C₅H₅)Cl{=C=CH-C=CH-(CH ₂)₃CH₂}(PⁱPr₃) (12) and Os(η⁵-C₅H₅)Cl{=C=CH-C(CH ₃)=CH₂)(PⁱPr₃) (13). Complex 13 can also be prepared by reaction of 2 with 2-methyl-1-buten-3-yne at room temperature. In this case, a π-alkyne intermediate related to 10 and 11 was not detected even at -60 °C. However, the reaction of 2 with phenylacetylene initially gives Os(η⁵-C₅H₅)Cl{η ²-HC≡CPh}(PⁱPr₃) (14), which subsequently evolves into Os(η⁵-C₅H₅)Cl{=C=CHPh}PⁱPr ₃) (15). Protonation of 12, 13, and 15 with HBF₄ afford the carbyne derivatives [Os(η⁵-C₅H₅)-Cl{=C-CH=C(CH ₂)₄CH₂}(PⁱPr₃)]BF ₄ (16), [Os(η⁵-C₅H₅)Cl{≡C-CH=C(CH ₃)₂}(PⁱPr₃)]BF₄ (17), and [Os(η⁵-C₅H₅)Cl(≡C-CH ₂Ph)(PⁱPr₃)]BF₄ (18), respectively. The structure of 16 was determined by an X-ray investigation. The Os≡C bond length is 1.756(8) A?, while the Os-C-C angle is 167.8(6)°.

Full text of DOI:10.1021/om970237c

Organometallics 1997, 16, 4657-4667
4657
Meyer ’s Com p lex OsH2Cl2(P iP r 3)2 a s a P r ecu r sor for th e
P r ep a r a tion of New Cyclop en ta d ien ylosm iu m
Com p ou n d s
Miguel A. Esteruelas,* Ana M. Lo´pez, Natividad Ruiz, and J ose´ I. Tolosa
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-Consejo Superior de Investigaciones Cient´ıficas,
50009 Zaragoza, Spain
Received March 24, 1997X
The six-coordinate complex OsH2Cl2(PiPr3)2 (1) reacts with cyclopentadienylthallium to
give Os(η5-C5H5)Cl(PiPr3)2 (2). In methanol and acetone, 2 dissociates the chlorine ligand
and the resulting metallic fragment is capable of activating a methyl C-H bond of a
triisopropylphosphine to afford [OsH(η5-C5H5){CH2CH(CH3)PiPr2}(PiPr3)]+ (3), which can be
isolated as the PF6 salt by addition of either NaPF6 or TlPF6. Treatment of a 1:10 mixture
of 2 and NaBH4 in toluene with 1.0 mL of methanol affords OsH(η5-C5H5)(PiPr3)2 (4) , which
by protonation with HBF4‚OEt2 yields [OsH2(η5-C5H5)(PiPr3)2]BF4 (5). In pentane, complex
2 reacts with trimethyl phosphite to give Os(η5-C5H5)Cl{P(OMe)3}(PiPr3) (6). Similarly, the
addition of methyl vinyl ketone and dimethyl acetylenedicarboxylate to toluene solutions of
2 produces the displacement of a phosphine ligand from 2 and the formation of Os(η5-
C5H5)Cl{η2-CH2dCHC(O)CH3}(PiPr3) (7) and Os(η5-C5H5)Cl{η2-C(CO2CH3)tCCO2CH3}(Pi-
Pr3) (8), respectively. Complex 2 also reacts with ethyl diazoacetate to give Os(η5-C5H5)Cl{η2-
(Z)-CH(CO2C2H5)dCHCO2C2H5}(PiPr3) (9) and with 1-ethynyl-1-cyclohexanol and 2-methyl-
3-butyn-2-ol to afford Os(η5-C5H5)Cl{η2-HCtCsC(OH)(CH2)4CH2}(PiPr3) (10) and Os(η5-
C5H5)Cl{η2-HCtCsC(OH)(CH3)2}(PiPr3) (11). In toluene at 85 °C, complexes 10 and 11
evolve to the corresponding alkenylvinylidene derivatives Os(η5-C5H5)Cl{dCdCHsCdCH-
(CH2)3CH2}(PiPr3) (12) and Os(η5-C5H5)Cl{dCdCHsC(CH3)dCH2}(PiPr3) (13). Complex 13
can also be prepared by reaction of 2 with 2-methyl-1-buten-3-yne at room temperature. In
this case, a π-alkyne intermediate related to 10 and 11 was not detected even at -60 °C.
However, the reaction of 2 with phenylacetylene initially gives Os(η5-C5H5)Cl{η2-HCtCPh}(Pi-
Pr3) (14), which subsequently evolves into Os(η5-C5H5)Cl{dCdCHPh}(PiPr3) (15). Proto-
nation of 12, 13, and 15 with HBF4 afford the carbyne derivatives [Os(η5-C5H5)-
Cl{tCsCHdC(CH2)4CH2}(PiPr3)]BF4 (16), [Os(η5-C5H5)Cl{tCsCHdC(CH3)2}(PiPr3)]BF4
(17), and [Os(η5-C5H5)Cl(tCsCH2Ph)(PiPr3)]BF4 (18), respectively. The structure of 16 was
determined by an X-ray investigation. The OstC bond length is 1.756(8) Å, while the Os-
C-C angle is 167.8(6)°.
In tr od u ction
symmetry and can be described as a square antiprism
with two missing vertices.6 In solution, it exits as two
Half-sandwich pentamethylcyclopentadienyl- and cy-
clopentadienylruthenium complexes exhibit a particu-
larly rich and interesting chemistry, which has formed
one of the cornerstones in the development of the
organometallic field.1 The chemistry of the related half-
sandwich osmium complexes has attracted compara-
tively less attention,2 in particular that containing the
Os(η5-C5H5) unit.3 This is in part due to the lack of
convenient osmium synthetic precursors4 and the higher
kinetic stability of the CpOsL3 compounds in comparison
with the related iron and ruthenium complexes.5
In 1985, U. Meyer, a member of Werner’s group, found
that the treatment of OsCl3‚xH2O with triisopropy-
lphosphine in refluxing 2-propanol leads to OsH2Cl2(Pi-
Pr3)2 (1). The solid-state structure of this compound,
significantly distorted from octahedral, has only a C2
rapidly interconverting isomers, one having C2 sym-
(2) (a) Hoyano, J . K.; Graham, W. A. G. J . Am. Chem. Soc. 1982,
104, 3722. (b) Weber, L.; Bungardt, D. J . Organomet. Chem. 1986, 311,
269. (c) Pourreau, D. B.; Geoffroy, G. L.; Rheingold, A. L.; Geib, S. J .
Organometallics 1986, 5, 1337. (d) Weber, L.; Reizig, K.; Bungardt,
D.; Boese, R. Organometallics 1987, 6, 110. (e) J ohnston, L. J .; Baird,
M. C. Organometallics 1988, 7, 2469. (f) J onhston, L. J .; Baird, M. C.
J . Organomet. Chem. 1988, 358, 405. (g) Gross, Ch. L.; Wilson, S. R.;
Girolami, G. S. J . Am. Chem. Soc. 1994, 116, 10294. (h) Gross, Ch. L.;
Girolami, G. S. Organometallics 1996, 15, 5359. (i) Rink, B.; Scherer,
O. J .; Wolmersha¨user, G. Chem. Ber. 1995, 128, 71. (j) Cadierno, V.;
Gamasa, M. P.; Gimeno, J .; Gonza´lez-Cueva, M.; Lastra, E.; Borge, J .;
Garc´ıa-Granda, S.; Pe´rez-Carren˜o, E. Organometallics 1996, 15, 2137.
(3) (a) Bruce, M. I.; Wong, F. S. J . Organomet. Chem. 1981, 210,
C5. (b) Hoyano, J . K.; May, Ch. 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) Rottink, M.
K.; Angelici, R. J . J . Am. Chem. Soc. 1993, 115, 7267. (f) J ia, G.; Ng,
W. S.; Yao, J .; Lau, C.; Chen, Y. Organometallics 1996, 15, 5039. (g)
Bruce, M. I.; Humphrey, M. G.; Koutsantonis, G. E.; Liddell, M. J . J .
Organomet. Chem. 1987, 326, 247. (h) Kawano, Y.; Tobita, H.; Ogino,
H. Organometallics 1994, 13, 3849. (i) Bruce, M. I.; Koutsantonis, G.
A.; Liddell, M. J .; Nicholson, B. K. J . Organomet. Chem. 1987, 320,
217. (j) Freedman, D. A.; Gill, T. P.; Blough, A. M.; Koefod, R. S.; Mann,
K. R. Inorg. Chem. 1997, 36, 95.
X Abstract published in Advance ACS Abstracts, September 15, 1997.
(1) (a) Albers, M. O.; Robinson, D. J .; Singleton, E. Coord. Chem.
Rev. 1987, 79, 1. (b) Davis, S. G.; McNally, J . P.; Smallridge, A. J .
Adv. Organomet. Chem. 1990, 30, 1.
S0276-7333(97)00237-9 CCC: $14.00 © 1997 American Chemical Society

4658 Organometallics, Vol. 16, No. 21, 1997
Esteruelas et al.
metry and the other with no symmetry.7 In recent
years, Werner, Caulton, and our group have proved that
complex 1 is a unique species with a completely different
chemical behavior than that of previously reported
compounds. In this sense, it should be mentioned that
it catalyzes the reduction of ketones, olefins, and
diolefins6b and is a useful starting material to prepare
dihydrogen,8 polyhydrido,9 carbyne,10 and diolefin11
derivatives of osmium II and IV.
Some months ago, we reported that OsHCl(CO)(Pi-
Pr3)2, which is prepared similarly to 1 but in methanol,12
reacts with cyclopentadiene to afford OsH(η5-C5H5)-
(CO)(PiPr3). This complex has been the starting point
for new half-sandwich osmium complexes including
hydrido, halide, vinylidene, and vinylvinylidene deriva-
tives.13 In the search for new cyclopentadienylosmium
synthetic precursors, and as a continuation of our work
in the study of the chemical properties of complex 1,
we have now carried out the reaction of 1 with cyclo-
pentadienylthallium in order to obtain Os(η5-C5H5)Cl(Pi-
Pr3)2. In this paper, we report the synthesis and some
of the potential chemistry of this compound.
benzene, and its solutions are stable under argon for a
matter of days. However, in methanol and acetone,
complex 2 dissociates the chlorine ligand and the
resulting metallic fragment is capable of activating a
methyl C-H bond of a triisopropylphosphine to afford
a 1:1 mixture of isomers a and b (eq 2) of the cationic
derivative [OsH(η5-C5H5){CH2CH(CH3)PiPr2}(PiPr3)]+
(3). Complex 3 was isolated as the PF6 salt either by
Resu lts a n d Discu ssion
Syn th esis a n d Ch a r a cter iza tion of Os(η5-C5H5)-
Cl(P iP r 3)2. Treatment of a toluene solution of OsH2-
Cl2(PiPr3)2 (1) with cyclopentadienylthallium in a 1:1
mol ratio for 2 h gives, after filtration and solvent
removal, a sticky residue. Pentane extraction of the
residue and subsequent filtration of the resulting sus-
pension leads to an orange solution, which affords the
cyclopentadienyl complex Os(η5-C5H5)Cl(PiPr3)2 (2) as
an orange solid in 52% yield, by cooling at -78 °C (eq
1). The most characteristic spectroscopic fact of 2 is a
singlet at -1.2 ppm in the 31P{1H} NMR spectrum.
Complex 2, which is an air-sensitive solid, is stable for
a week if kept under argon at -20 °C. It is easily
soluble in solvents such as pentane, toluene, and
addition of NaPF6 to the methanol solution (61% yield)
or by addition of TlPF6 to the acetone solution (86%
yield). Complex 3 is a white solid. In solution, the
1
presence of isomers 3a and 3b is supported by the H,
13C{1H}, and 31P{1H} NMR spectra of 3. In the 1H NMR
spectrum, the most noticeable resonances are those due
to the hydrido ligands, which appear at -13.81 and
-13.98 ppm as double doublets with P-H coupling
constants of 36.0 and 27.9 and 38.0 and 25.4 Hz,
respectively. Similar P-H coupling constants have
(4) (a) Bruce, M. I.; Windsor, N. J . Aust. J . Chem. 1977, 30, 1601.
(b) Hermann, W. A.; Herdtweeck, E.; Scha¨fer, A. Chem. Ber. 1988, 121,
1907. (c) Dev, S.; Selegue, J . P. J . Organomet. Chem. 1994, 469, 107.
(5) Atwood, J . D. Inorganic and Organometallic Reaction Mecha-
nisms; Brooks/Cole Publishing: Monterrey, CA, 1985; p 90.
(6) (a) Meyer, U. Ph.D. Thesis, University of Wu¨rzburg, Wu¨rzburg,
Germany, 1988. (b) Aracama, M.; Esteruelas, M. A.; Lahoz, F. J .; Lo´pez,
J . A.; Meyer, U.; Oro, L. A.; Werner, H. Inorg. Chem. 1991, 30, 288.
(7) Gusev, D. G.; Kuhlman, R.; Rambo, J . R.; Berke, H.; Eisenstein,
O.; Caulton, K. G. J . Am. Chem. Soc. 1995, 117, 281.
been observed for the monohydrido RuH(η5-C5Me5){CH2-
CH(CH3)PiPr2}{Si(CH3)Ph2} (22.5 Hz)14 and dihydrido
[OsH2(η5-C5H5)(PPh3)2]+ (29.0 Hz),3e whose cis-(P,H)
four-legged piano-stool geometries have been deter-
mined by X-ray diffraction. In the 13C{1H} NMR
spectrum, the OsCH2 and PCH(CH3) resonances of the
metalated isopropyl group are observed at -36.9 and
-37.4 and 49.9 and 46.9 ppm, respectively, in agree-
ment with the chemical shift previously reported for the
(8) (a) Esteruelas, M. A.; Oro, L. A.; Ruiz, N. Inorg. Chem. 1993,
32, 3793. (b) Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; On˜ate, E.;
Ruiz, N. Inorg. Chem. 1994, 33, 787.
(9) (a) Ruiz, N. Ph.D. Thesis, University of Zaragoza, Zaragoza,
Spain, 1994. (b) Gusev, D. G.; Kuznetsov, V. F.; Eremenko, I. L.; Berke,
H. J . Am. Chem. Soc. 1993, 115, 5831. (c) Gusev, D. G.; Kuhlman, R.;
Sini, G.; Eisenstein, O.; Caulton, K. G. J . Am. Chem. Soc. 1994, 116,
2685. (d) Esteruelas, M. A.; Oro, L. A.; Ruiz, N. Organometallics 1994,
13, 1507. (e) Esteruelas, M. A.; J ean, Y.; Lledo´s, A.; Oro, L. A.; Ruiz,
N.; Volatron, F. Inorg. Chem. 1994, 33, 3609. (f) Kuhlman, R.; Streib,
W. E.; Caulton, K. G. Inorg. Chem. 1995, 34, 1788. (g) Atencio, R.;
Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Ruiz, N. Inorg. Chem. 1995,
34, 1004. (h) Demachy, I.; Esteruelas, M. A.; J ean, Y.; Lledo´s, A.;
Maseras, F.; Oro, L. A.; Valero, C.; Volatron, F. J . Am. Chem. Soc.
1996, 118, 8388. (i) Esteruelas, M. A.; Lahoz, F. J .; Lo´pez, A. M.; On˜ate,
E.; Oro, L. A.; Ruiz, N.; Sola, E.; Tolosa, J . I. Inorg. Chem. 1996, 35,
7811.
(10) Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Ruiz,
N. J . Am. Chem. Soc. 1993, 115, 4683.
(11) 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.
(12) Esteruelas, M. A.; Werner, H. J . Organomet. Chem. 1986, 303,
221.
compounds RuH(η5-C5Me5){CH2CH(CH3)PiPr2}{Si(CH3)-
Ph2} (-3.15 and 42.80 ppm)14 and RuH(η6-C6H6){CH2-
CH(CH3)PiPr2} (-10.74 and 42.80 ppm).15 The 31P{1H}
NMR spectrum of 3 shows four doublets at 8.0 and 4.4
(PiPr3) and -33.1 and -37.4 (PCHCH2Os) ppm, with
P-P coupling constants of about 20 Hz. Under off-
resonance conditions, each doublet is split into a virtual
triplet as a result of the P-H coupling with only one
hydrido ligand.
(14) Campion, B. K.; Heyn, R. H.; Tilley, T. D.; Rheingold, A. L. J .
Am. Chem. Soc. 1993, 115, 5527.
(13) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; Oro, L. A.
Organometallics 1996, 15, 878.
(15) Kletzin, H.; Werner, H. Angew. Chem., Int. Ed. Engl. 1983, 22,
873.

Preparation of Cyclopentadienylosmium Compounds
Organometallics, Vol. 16, No. 21, 1997 4659
dihydrido cations [OsH2(η5-C5H5)(PPh3)2]+ (29.0 Hz)3e
and [OsH2(η5-C5H5)(CO)(PiPr3)]+ (28.8 Hz).13 In addi-
tion, it should be noted that a cis-dihydrido structure
should give rise to an AA′XX′ spin system. The 31P-
{1H} NMR spectrum shows a singlet at 32.2 ppm, which
is split into a triplet under off-resonance conditions as
a result of the P-H coupling with two hydrido ligands.
Although complex 2 is easily soluble in pentane and
its solutions are stable for a matter of days, in this
solvent the complex shows a high tendency to release a
phosphine ligand, most probably, as a consequence of
the large steric hindrance experienced by the triisopro-
pylphosphine groups, which is a result of their large
cone angle (160°).18 Thus, in pentane, one of the
triisopropylphosphine ligands of 2 can be quantitatively
displaced (according to the NMR spectroscopy) by tri-
methyl phosphite to afford Os(η5-C5H5)Cl{P(OMe)3}(Pi-
Pr3) (6), which was isolated as a yellow solid, only in
36% yield due to its high solubility in pentane (eq 3).
Sch em e 1
We note that the metalated-phosphine complexes
MH(η2-CH2PMe2)(PMe3)3 (M ) Fe,16 Os17) react with
methanol to give the corresponding dihydrido deriva-
tives MH2(PMe3)4. In contrast to these compounds,
complex 3 is stable in a methanol solution and the
formation of the dihydrido [OsH2(η5-C5H5)(PiPr3)2]+ does
not take place, even after a week at 60 °C. However,
this dihydrido complex, 5, can be prepared according to
Scheme 1. Treatment of a 1:10 mixture of 2 and NaBH4
in toluene with 1.0 mL of methanol affords the mono-
hydrido OsH(η5-C5H5)(PiPr3)2 (4) in quantitative yield.
The protonation of this monohydrido with HBF4‚OEt2
in diethyl ether gives the dihydrido 5. Related cyclo-
pentadienylosmium phosphine hydrido complexes have
been previously reported.3c-f,13
The presence of the trimethyl phosphite ligand in 6 is
supported by the 31P{1H} NMR spectrum, which shows
two doublets at 103.7 (P(OMe)3) and 14.4 (PiPr3) ppm,
with a P-P coupling constant of 34.6 Hz.
R ea ct ion s of
2 w it h Olefin s a n d In t er n a l
Alk yn es: Syn th esis of π-Olefin a n d π-Alk yn e Com -
p lexes. In toluene, complex 2 also shows a high
tendency to release a phosphine ligand. Thus, the
treatment of toluene solutions of 2 with methyl vinyl
ketone and dimethyl acetylenedicarboxylate affords the
derivatives Os(η5-C5H5)Cl{η2-CH2dCHC(O)CH3}(PiPr3)
(7) and Os(η5-C5H5)Cl{η2-C(CO2CH3)tCCO2CH3}(PiPr3)
(8) (Scheme 2). The reactions proceed at room temper-
ature and do not lead to displacement of the second
phophine, even if excess of unsaturated organic sub-
strate is used.
Complex 4 was isolated as a yellow oil and character-
1
ized by MS analysis and IR and H and 31P{1H} NMR
Complex 7 was isolated as a yellow solid in 83% yield.
The presence of the R,â-unsaturated ketone in the
complex is supported by the IR spectrum in Nujol, which
shows a ν(CO) band at 1661 cm-1. This value is lower
than the frequency for free methyl vinyl ketone observed
at 1681 cm-1. The resonances of the olefinic protons of
this ligand (Figure 1a) can be simulated using an ABMX
(X ) P) spin system (Figure 1b). The low value (9.4 Hz)
of the J (AB) coupling constant (A and B, hydrogen
protons mutually trans disposed) should be noted, which
is reduced by 8 Hz with regard to the H-H coupling
constant between the hydrogen protons mutually trans
disposed in the free methyl vinyl ketone (17.4 Hz). This
suggests that the coordination of the carbon-carbon
double bond of the R,â-unsaturated ketone to the
osmium center of 2 produces a weaker intraligand
carbon-carbon double bond than that expected, as a
result of the unusually strong π-donor power of the
metallic center. This is also revealed by the 13C{1H}
NMR spectrum, which shows the resonances of the
olefinic carbon atoms at 46.7 and 19.6 ppm, shifted
spectroscopies. In the 1H NMR spectrum, the most
noticeable resonance is a triplet with a P-H coupling
constant of 31.1 Hz at -16.10 ppm, which was assigned
to the hydrido ligand. The 31P{1H} NMR spectrum
contains a singlet at 29.4 ppm, which under off-
resonance conditions splits into a doublet due to the
P-H coupling.
Complex 5 was isolated as a white solid in 76% yield
1
and characterized by elemental analysis and IR and H
and 31P{1H} NMR spectroscopies. The IR spectrum in
Nujol shows the absorption due to the [BF4]- anion with
Td symmetry between 1030 and 1080 cm-1, along with
two weak ν(OsH) bands at 2146 and 2203 cm-1. The
trans disposition of the hydrido ligands is proposed on
the basis of the 1H NMR spectrum in chloroform-d,
where the complex is stable. This spectrum, which is
temperature invariant between 293 and 213 K, contains
a single triplet at -14.26 ppm in the high-field region
with a P-H coupling constant of 28.8 Hz. Similar J (PH)
coupling constants have been observed for the trans-
(16) Karsch, H. H.; Klein, H. F.; Schmidbaur, H. Chem. Ber. 1977,
110, 2200.
(17) Werner, H.; Gotzig, J . Organometallics 1983, 2, 547.
(18) Li, C. B.; Ogasowara, M.; Nolan, S. P.; Caulton, K. G. Orga-
nometallics 1996, 15, 4900.

4660 Organometallics, Vol. 16, No. 21, 1997
Esteruelas et al.
Sch em e 2
ML2.19 The 31P{1H} NMR spectrum of 7 contains a
singlet at 5.7 ppm.
Complex 8 was isolated as a brown solid in 73% yield.
The π-coordination of the alkyne in this complex is
supported by its IR spectrum in Nujol, in which the CtC
stretching frequency is found at 1825 cm-1, shifted 325
cm-1 to lower wavenumbers if compared with the free
alkyne. In the 13C{1H} NMR spectrum, the resonances
of the acetylenic carbon atoms appear at 70.2 and 69.8
ppm. The first resonance appears as a broad signal,
while the second resonance is observed as a doublet with
a P-C coupling constant of 8.3 Hz. The 31P{1H} NMR
spectrum shows a singlet at 17.3 ppm.
A particularly noteworthy carbon-carbon coupling
reaction takes place in the presence of 2 (Scheme 2).
Treatment of a toluene solution of 2 with ethyl diaz-
oacetate in a 1:3 mol ratio at room temperature after
15 h leads to the π-olefin complex Os(η5-C5H5)Cl{η2-(Z)-
CH(CO2C2H5)dCHCO2C2H5}(PiPr3) (9), which was iso-
lated as a yellow solid in 52% yield. Previously, it has
been reported that the meso-tetra-p-tolylporphyrin com-
plex [Os(TTP)]2 reacts with diazoalkenes to give the
corresponding carbene derivatives, which catalytically
convert ethyl diazoacetate to diethyl maleate and di-
ethyl fumarate in high yields and high stereoselectiv-
ity.20 In contrast to this osmium complex, the rhodium
compound [RhCl(PiPr3)2]2 reacts with diazomethane to
give RhCl(η2-CH2dCH2)(PiPr3)2.21
The presence of the olefin ligand in 9 is mainly
1
supported by the H and 13C{1H} NMR spectra. In the
1H NMR spectrum, the resonances of the olefinic protons
are observed as the AB part of an ABX (X ) P) spin
system with δA ) 4.35, δB ) 4.31, J (AB) ) 9.9 Hz, and
J (XA) ) J (XB) ) 4.3 Hz. The value of the J (AB)
coupling constant is similar to the values obtained for
J (AB) (9.4 Hz) and J (MB) (6.5 Hz) in the case of the
methyl vinyl ketone complex 7. So in order to assign
the stereochemistry to the olefin ligand of 9, we carried
out an X-ray diffraction analysis of a monocrystal of 9.
Although the low quality of the monocrystals obtained
has not allowed the perfect refinement of the structure,
from the X-ray diffraction analysis it is inferred that
F igu r e 1. (a) Observed 1H NMR resonances for the olefinic
protons of 7. (b) Simulated 1H NMR resonances for the
olefinic protons of 7.
toward high field by about 100 ppm in comparison with
the resonances of the free ligand (137.43 and 128.75
ppm). The electron-rich behavior of the metallic center
of this system, which is also confirmed by the reaction
shown in eq 2, is in agreement with the metal-based
character of the half-sandwich complexes of type (C5R5)-
(19) Werner, H. Angew. Chem., Int. Ed. Engl. 1983, 22, 927.
(20) Woo, L. K.; Smith, D. A. Organometallics 1992, 11, 2344.
(21) Werner, H. J . Organomet. Chem. 1994, 475, 45.

Preparation of Cyclopentadienylosmium Compounds
Organometallics, Vol. 16, No. 21, 1997 4661
Sch em e 3
the olefin ligand has a cis-stereochemistry. In the 13C-
{1H} NMR spectrum, the resonances of the olefinic
carbon atoms appear at 34.5 and 29.8 ppm, similar to
the olefinic resonances of 7, shifted toward high field
by about 100 ppm in comparison with that found in the
free olefin (129.8 ppm). The 31P{1H} NMR spectrum
shows a singlet at 2.0 ppm.
R ea ct ion s of 2 w it h Alk yn ols a n d Ter m in a l
Alk yn es: Syn th esis of Alk en ylvin ylid en e a n d Vi-
n ylid en e Der iva tives. The investigations aimed to
elucidate the reactivity of complex 2 toward alkynols
and terminal alkynes are summarized in Scheme 3. In
agreement with the tendency shown by 2 to release a
triisopropylphosphine ligand, the treatment of this
compound with 1-ethynyl-1-cyclohexanol and 2-methyl-
3-butyn-2-ol in pentane leads to the π-alkyne com-
bene compounds, via allenylidene intermediates.22 In
the same sense, we have recently reported that the
solvato complex [Ru(η5-C5H5){η1-OC(CH3)2}(CO)(PiPr3)]-
BF4 reacts with 1-ethynyl-1-cyclohexanol to give the
hydroxycarbene complex [Ru(η5-C5H5){C(OH)CHd
C(CH2)4CH2}(CO)(PiPr3)]BF4.23 In contrast to these
systems, the rich-electron fragments [Ru(η5-C5H5)-
25
(PMe3)2]+ 24 and [RhCl(PiPr3)2]2 preferentially afford
alkenylvinylidene derivatives. The formation of 12 and
13 from 2 is in agreement with the previously men-
tioned strong Lewis base character of the Os(η5-
C5H5)Cl(PiPr3) moiety, which could be a consequence of
both the high basicity of the phosphine and the large
π-donor power of the chlorine. Furthermore, it should
be noted that osmium shows an intrinsically higher
basicity than ruthenium.26
The π-alkyne complexes 10 and 11 were isolated as
brown solids in 52% and 76% yield, respectively. The
presence of the π-alkyne ligand in these compounds was
mainly inferred from the 13C{1H} NMR spectra, which
contains resonances at 71.8 and 53.1 (10) and 69.1 and
49.6 (11) ppm.
The alkenylvinylidene compounds 12 and 13 were
isolated as red solids in 50% and 63% yield, respectively.
In the 13C{1H} NMR spectra, the most noticeable
resonances are those corresponding to the carbon atoms
of the η1-unsaturated ligand. In the spectrum of 12, the
resonance of the CR carbon atom appears at 292.7 ppm
as a doublet, with a P-C coupling constant of 13.4 Hz,
whereas that corresponding to the Câ carbon atom is
observed at 114.5 ppm as a singlet. The carbon atoms
of the alkenyl group give rise to singlets at 126.2 and
pounds Os(η5-C5H5)Cl{η2-HCtCsC(OH)(CH2)4CH2}(Pi-
Pr3) (10) and Os(η5-C5H5)Cl{η2-HCtCsC(OH)(CH3)2}-
(PiPr3) (11), which evolve to the corresponding alk-
enylvinylidene derivatives Os(η5-C5H5)Cl{dCdCHs
CdCH(CH2)3CH2}(PiPr3) (12) and Os(η5-C5H5)Cl{dCd
CHsC(CH3)dCH2}(PiPr3) (13) by loss of a water mol-
ecule, in toluene at 85 °C.
The behavior of 2 toward 1-ethynyl-1-cyclohexanol
and 2-methyl-3-butyn-2-ol agrees well with that previ-
ously observed for the carbonyl complex Os(η5-C5H5)-
Cl(CO)(PiPr3), which reacts with 1-ethynyl-1-cyclohex-
anol in the presence of AgBF4 to give [Os(η5-C5H5)-
{dCdCHsCdCH(CH2)3CH2}(CO)(PiPr3)]BF4.13 The for-
mation of these alkenylvinylidene compounds most
probably involves hydroxyvinylidene intermediates which
spontaneously dehydrate. The dehydration of hydrox-
yvinylidenes, containing hydrogen atoms adjacent to the
hydroxy group, can occur in two different directions to
afford either alkenylvinylidene or allenylidene deriva-
tives, mainly, depending on the electronic properties of
the metallic center. The metallic fragments [RuCl(η6-
arene)(PR3)]+ and [Ru(η5-C5H5)(CO)(PiPr3)]+, which are
weak Lewis bases, appear to promote dehydration to
allenylidene. Thus, Dixneuf has observed that in the
presence of NH4PF6/MeOH, the reactions of RuCl2(η6-
C6H6)(PMe3) with 1,1-dimethyl-2-propyn-1-ol and 1-ethy-
nyl-1-cyclohexanol lead to R,â-unsaturated methoxycar-
(22) (a) Le Bozec, H.; Ouzzine, K.; Dixneuf, P. H. J . Chem. Soc.,
Chem. Commun. 1989, 219. (b) Pilette, D.; Ouzzine, K.; Le Bozec, H.;
Dixneuf, P. H.; Richard, C. E. F.; Roper, W. R. Organometallics 1992,
11, 809. (c) Peron, D.; Romero, A.; Dixneuf, P. H. Organometallics 1995,
14, 3319.
(23) Esteruelas, M. A.; Go´mez, A. V.; Lahoz, F. J .; Lo´pez, A. M.;
On˜ate, E.; Oro, L. A. Organometallics 1996, 15, 3423.
(24) (a) Selegue, J . P. Organometallics 1982, 1, 217. (b) Selegue, J .
P. J . Am. Chem. Soc. 1983, 105, 5921. (c) Selegue, J . P.; Young, B. A.;
Logan, S. L. Organometallics 1991, 10, 1972.
(25) (a) Rappert, T.; Nu¨rnberg, O.; Mahr, N.; Wolf, J .; Werner, H.
Organometallics 1992, 11, 4156. (b) Werner, H.; Rappert, T. Chem.
Rev. 1993, 126, 699. (c) Werner, H.; Rappert, T.; Wieemann, R.; Wolf,
J .; Mahr, N. Organometallics 1994, 13, 2721.
(26) Angelici, R. J . Acc. Chem. Res. 1995, 28, 51.

4662 Organometallics, Vol. 16, No. 21, 1997
Esteruelas et al.
118.7 ppm. In the spectrum of 13, the resonance of the
CR carbon atom appears at 291.4 ppm as a doublet, with
a P-C coupling constant of 13.2 Hz, and the Câ atom is
observed at 119.3 ppm as a singlet. The carbon atoms
of the alkenyl group also display singlets, in this case
at 134.2 and 103.7 ppm.
Complex 13 can be also prepared in 64% yield by
reaction of 2 with 2-methyl-1-buten-3-yne at room
temperature. In this case, a π-alkyne intermediate
related to 10 and 11 was not detected, even at -60 °C.
However, when the alkyne is phenylacetylene, the
π-alkyne intermediate can be detected. Thus, after 5
F igu r e 2. Molecular diagram of complex [Os(η5-
C5H5)Cl{tCsCHdC(CH2)4CH2}(PiPr3)]BF4 (16). Thermal
1
min, the H and 31P{1H} NMR spectra of the solution
formed by addition of 1 equiv of phenylacetylene to 2
in benzene-d6 show resonances corresponding to the
starting complex 2, the π-alkyne Os(η5-C5H5)Cl(η2-
HCtCPh)(PiPr3) (14), the vinylidene Os(η5-C5H5)
Cl(dCdCHPh)(PiPr3) (15), and free triisopropylphos-
phine. After 30 min, the spectra contain only reso-
nances due to 2 and 15 in a 5:95 molar ratio and free
triisopropylphosphine. From this solution the vi-
nylidene complex 15 was isolated as a red solid in 64%
yield, after benzene-d6 removal and addition of pentane.
The above-mentioned observations suggest that for
2-methyl-1-buten-3-yne and phenylacetylene the isomer-
ization π-alkyne-vinylidene is faster than the substitu-
tion of the phosphine by the alkyne. However for the
alkynols, the replacement of the phosphine seems to be
favored. This could be a result of the presence of an
OH group on the alkyne ligand, which should increase
the π-acceptor capacity of the ligand and, therefore, the
stability of the π-alkyne intermediate.
The π-alkyne-vinylidene transformation is generally
viewed either as a 1,2-hydrogen shift or as a 1,3-
hydrogen shift via hydrido-alkynyl intermediates.27
Theoretical studies suggest that the use of energy to
promote the concerted migration of the hydrido ligand
from the metal to the â-carbon atom of the alkyne group
in the 1,3-hydrogen shift is prohibitive.28 However,
experimental evidence suggest that the intermediacy of
alkynyl(hydrido) complexes could also be possible in
some cases.25a,29 Thus, for example, Puerta has reported
that the half-sandwich compound Ru(η5-C5Me5)Cl-
(dippe) (dippe ) 1,2-bis(diisopropylphosphino)ethane)
reacts with terminal alkynes in methanol in the pres-
ence of NaBPh4 yielding the metastable hydrido(alky-
nyl) derivatives [Ru(η5-C5Me5)(H)(CtCR)(dippe)]BPh4,
which are intermediates in the formation of the corre-
sponding vinylidene complexes.30 Very recently, theo-
retical calculations on Werner’s system, RhCl(η2-
HCtCR)(PiPr3)2, appear to indicate that the isomer-
ellipsoids are shown at 50% probability.
ization proceeds via the oxidative addition products
RhHCl(CtCR)(PiPr3)2, followed by a bimolecular hy-
drogen shift from the metal to the Câ alkynyl carbon
atom of a second molecule.31 During the isomerization
of π-alkyne complex 14 into the vinylidene derivative
15, we have not found spectroscopic evidence of the
participation of a hydrido(alkynyl) intermediate, related
to those reported by Puerta.
1
Characteristic resonances of 14 are, in the H NMR
spectrum, a doublet at 8.18 ppm, with a P-H coupling
constant of 7.8 Hz, assigned to the HCt proton and in
the 31P{1H} NMR spectrum a relatively broad singlet
at 11.5 ppm. The most noticeable feature in the 1H
NMR spectrum of 15 is a singlet at 2.83 ppm, corre-
sponding to the dCH vinylidene proton. In the 13C{1H}
NMR spectrum, the resonance corresponding to the CR
carbon atom of the vinylidene ligand appears at 291.6
ppm as a doublet with a P-C coupling constant of 13.6
Hz, whereas the resonance due to the Câ carbon atom
is observed at 116.1 ppm as a singlet. The 31P{1H}
NMR spectrum of 15 shows a singlet at 19.4 ppm.
P r oton a tion of 12, 13, a n d 15: Syn th esis of
Alk en ylca r byn e a n d Ca r byn e Der iva tives. Treat-
ment of complex 12 with a stoichiometric amount of
HBF4‚OEt2 in chloroform-d leads to the alkenylcarbyne
compound [Os(η5-C5H5)Cl{tCsCHdC(CH2)4CH2}(Pi-
Pr3)]BF4 (16), which was isolated as a red solid in 90%
yield, after solvent removal and addition of diethyl ether
(eq 4). Complex 16 was characterized by elemental
(27) Bruce, M. I. Chem Rev. 1991, 91, 197.
analysis, IR and 1H, 31P{1H} and 13C{1H} NMR spec-
troscopies, and an X-ray diffraction study. The molec-
ular structure is presented in Figure 2, while selected
bond distances and angles are listed in Table 1. The
geometry around the osmium center is close to octahe-
dral, with the cyclopentadienyl ligand occupying three
sites of a face. The angles P-Os-Cl, P-Os-C(6), and
Cl-Os-C(6) are 88.74(7)°, 94.1(3)°, and 104.8(3)°, re-
spectively. The most conspicuous feature of the struc-
ture is the very short Os-C(6) bond length of 1.756(8)
(28) Silvestre, J .; Hoffmann, R. Helv. Chim. Acta 1985, 68, 1461.
(29) (a) Wolf, J .; Werner, H.; Serhadli, O.; Ziegler, M. L. Angew.
Chem., Int. Ed. Engl. 1983, 22, 414. (b) Garc´ıa Alonso, F. J .; Ho¨hn, A.;
Wolf, J ; Otto, H.; Werner, H. Angew. Chem., Int. Ed. Engl. 1985, 24,
406. (c) Ho¨hn, A.; Otto, H.; Dziallas, M.; Werner, H. J . Chem. Soc.,
Chem. Commun. 1987, 852. (d) Werner, H.; Garc´ıa Alonso, F. J .; Otto,
H.; Wolf, J . Z. Naturforsch. 1988, 436, 722. (e) Werner, H.; Brekau, U.
Z. Naturforsch. 1989, 446, 1438. (f) Ho¨hn, A.; Werner, H. J . Organomet.
Chem. 1990, 382, 255. (g) Werner, H.; Ho¨hn, A.; Schulz, M. J . Chem.
Soc., Dalton Trans. 1991, 777. (h) Bianchini, C.; Peruzzini, M.; Vacca,
A.; Zanobini, F. Organometallics 1991, 10, 3697. (i) Werner, H.;
Rappert, T.; Baum, M.; Stark, A. J . Organomet. Chem. 1993, 459, 319.
(j) Werner, H.; Baum, M.; Schneider, D.; Windmu¨ller, B. Organome-
tallics 1994, 13, 1089. (k) Esteruelas, M. A.; Oro, L. A.; Valero, C.
Organometallics 1995, 14, 3596.
(30) de los R´ıos, I.; J ime´nez-Tenorio, M.; Puerta, M. C.; Valerga, P.
J . Chem. Soc., Chem. Commun. 1995, 1757.
(31) Wakatsuki, Y.; Koga, N.; Werner, H.; Morokuma, K. J . Am.
Chem. Soc. 1997, 119, 360.

Preparation of Cyclopentadienylosmium Compounds
Organometallics, Vol. 16, No. 21, 1997 4663
to alkenylvinylidenes. Werner34c and our group10 have
observed that some reactions of dihydrido-osmium(IV)
complexes with alkynols also lead to derivatives of this
type.
Similar to the reaction shown in eq 4, the protonation
of complex 13 with a 1 equiv of HBF4 affords [Os(η5-
C5H5)Cl{tCsCHdC(CH3)2}(PiPr3)]BF4 (17), which was
isolated as a red oil in quantitative yield (eq 5).
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for [Os(η5-C5H5)Cl-
{tCsCHdC(CH2)4CH2}(P iP r 3)]BF 4 (16)
Bond Lengths
Os-C(1)
Os-C(2)
Os-C(3)
Os-C(4)
Os-C(5)
2.217(8)
2.262(8)
2.350(8)
2.348(8)
2.203(8)
Os-P
2.374(2)
2.375(2)
1.756(8)
1.410(11)
1.327(11)
Os-Cl
Os-C(6)
C(6)-C(7)
C(7)-C(8)
Bond Angles
P-Os-Cl
88.74(7)
Os-C(6)-C(7)
167.8(6)
123.7(8)
121.4(8)
124.9(7)
113.6(7)
P-Os-C(6)
P-Os-G(1)a
Cl-Os-C(6)
Cl-Os-G(1)a
C(6)-Os-G(1)a
94.1(3)
125.5(3)
104.8(3)
114.9(3)
122.3(4)
C(6)-C(7)-C(8)
C(7)-C(8)-C(9)
C(7)-C(8)-C(13)
C(9)-C(8)-C(13)
a
G(1) is the midpoint of the C(1)-C(5) Cp ligand.
1
Complex 17 was characterized by MS analysis and H,
Å, which is fully consistent with a Os-C(6) triple bond
formulation.32 A slight bending in the Os-C(6)-C(7)
moiety is also observed. The value of this angle (167.8-
(6)°) agrees well with those found in other carbyne-
osmium derivatives.33 The bond lengths and angles
within the η1-unsaturated ligand are consistent with the
alkenylcarbyne proposal, e.g., C(6) and C(7) are sepa-
rated by 1.410(11) Å and C(7) and C(8) by 1.327(11) Å,
and the angles around C(7) and C(8) are in the range
121.4(8)-124.9(7)°. Similar values have been reported
for related compounds.34
In agreement with the X-ray diffraction study, the
13C{1H}NMR spectrum of 16 shows a doublet at 290.0
ppm with a P-C coupling constant of 10.1 Hz, corre-
sponding to the sp-carbon atom of the alkenylcarbyne
ligand. The resonances due to the sp2-carbons appear
at 187.2 and 134.6 ppm as singlets. The 31P{1H} NMR
spectrum contains a singlet at 33.6 ppm.
Although binuclear µ-alkenylcarbyne complexes are
well-known,35 the mononuclear alkenylcarbyne com-
pounds are rare. Kolobova and co-workers36 have
reported that the protonation of the allenylidene com-
plexes Mn(η5-C5H5)(CO)2(dCdCdCR2) yields [Mn(η5-
C5H5)(CO)2(tCsCHdCR2)]BF4. In addition, related
manganese,34a,37 rhodium,25a and tungsten34d derivatives
have been prepared using proton and methyl additions
1
31P{1H}, and 13C{1H} NMR spectroscopies. In the H
NMR spectrum, the most noticeable resonances are
three singlets at 5.45, 2.32, and 2.01 ppm, with a 1:3:3
intensity ratio, which were assigned to the CHd and
methyl protons of the η1-carbon ligand, respectively. In
the 13C{1H} NMR spectrum, the resonance due to the
sp-carbon atom of the η1-unsaturated ligand appears at
289.8 ppm as a doublet, with a P-C coupling constant
of 10.6 Hz, whereas the resonances of the sp2-carbon
atoms are observed at 181.8 and 137.9 ppm as singlets.
The 31P{1H} NMR spectrum shows a singlet at 36.0
ppm.
Complex 2 is not only the starting point to prepare
half-sandwich alkenylcarbyne-osmium complexes, but
also allows one to obtain simple carbyne derivatives.
Thus, the addition of a stoichiometric amount of HBF4
to the vinylidene complex 15 gives [Os(η5-C5H5)Cl-
(tCsCH2Ph)(PiPr3)]BF4 (18), which was isolated as a
green solid in 90% yield (eq 6). The most characteristic
(32) Schubert, U. Solid State Structures of Carbyne Complexes. In
Carbyne Complexes; Fischer, H., Hofmann, P., Kreissl, F. R., Schrock,
R. R., Schubert, U., Weiss, K., Eds.; VCH Verlagsgesellschaft mbH:
Weinheim, 1981; p 53.
(33) (a) Clark, G. R.; Marsden, K.; Roper, W. R.; Wright, L. J . J .
Am. Chem. Soc. 1980, 102, 6570. (b) Clark, G. R.; Edmonds, N. R.;
Paupfit, R. A.; Roper, W. R.; Waters, J . M.; Wright, A. H. J . Organomet.
Chem. 1983, 244, C57. (c) Roper, W. R. J . Organomet. Chem.1986, 300,
167 (d) Clark, G. R.; Cochrane, C. M.; Marsden, K.; Roper, W. R.;
Wright, L. J . J . Organomet. Chem. 1986, 315, 211.
spectroscopic features of 18 are an AB spin system (δA
) 3.92, δB ) 3.52, and J (AB) ) 19.9 Hz) for the CH2-
1
Ph protons in the H NMR spectrum, a doublet with a
P-C coupling constant of 9.8 Hz at 304.9 ppm for the
sp-carbon atom in the 13C{1H} NMR spectrum, and a
singlet at 38.3 ppm in the 31P{1H} NMR spectrum.
(34) (a) Terry, M. R.; Kelly, C.; Lugan, N.; Geoffroy, G. L.; Haggerty,
B. S.; Rheingold, A. L. Organometallics 1993, 12, 3607. (b) Esteruelas,
M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Zeier, B. Organometallics
1994, 13, 4258. (c) Weber, B.; Steinert, P.; Windmu¨ller, B.; Wolf, J .;
Werner, H. J . Chem. Soc., Chem. Commun. 1994, 2595. (d) Zhang, L.;
Gamasa, M. P.; Gimeno, J .; Carbajo, R. J .; Lo´pez-Ortiz, F.; Lanfranchi,
M.; Tiripicchio, D. Organometallics 1996, 15, 4724.
(35) (a) Nitay, M.; Priester, W.; Rosenblum, M. J . Am. Chem. Soc.
1978, 100, 3620. (b) Ustynyuk, N. A.; Vinogradova, V. N.; Andrianov,
V. G.; Struchkov, Yu. T. J . Organomet. Chem. 1984, 268, 73. (c) Casey,
C. P.; Marder, S. R. Organometallics 1985, 4, 411. (d) Casey, C. P.;
Konings, M. J .; Palermo, R. E.; Colborn, R. E. J . Am. Chem. Soc. 1985,
107, 5296. (e) Casey, C. P.; Konings, M. S.; Marder, S. R. Polyhedron
1988, 7, 881. (f) Casey, C. P.; Konings, M. S.; Marder, S. R. J .
Organomet. Chem. 1988, 345, 125. (g) Etienne, M.; Talarmin, J .;
Toupet, L. Organometallics 1992, 11, 2058.
Con clu d in g Rem a r k s
This study has revealed that Meyer’s complex OsH2-
Cl2(PiPr3)2 is a useful starting material for the prepara-
tion of new cyclopentadienylosmium compounds includ-
ing hydrido, dihydrido, π-olefin, π-alkyne, alkenyl-
vinylidene, vinylidene, alkenylcarbyne, and carbyne
derivatives. Thus, it reacts with cyclopentadienylthal-
lium to give Os(η5-C5H5)Cl(PiPr3)2, which is the starting
point of the above-mentioned chemistry.
The chemical behavior of this complex seems to be a
result of two factors: the high basicity of the metallic
(36) Kolobova, N. E.; Ivanov, L. L.; Zhvanko, O. S.; Khitrova, O. M.;
Batsanov, A. S.; Struchkov, Yu. T. J . Organomet. Chem. 1984, 262,
39.
(37) Kelley, C.; Lugan, N.; Terry, M. R.; Geoffroy, G. L.; Haggerty,
B. S.; Rheingold, A. L. J . Am. Chem. Soc. 1992, 114, 6735.

4664 Organometallics, Vol. 16, No. 21, 1997
Esteruelas et al.
0.21 mmol) in 10 mL of acetone was treated with 73.9 mg (0.21
mmol) of thallium hexafluorophosphate. The color of the
solution changed from orange to yellow. After the mixture was
stirred for 5 min at room temperature, the solution was filtered
through Kieselguhr and concentrated to dryness. Addition of
6 mL of diethyl ether caused the precipitation of a white solid,
which was separated by decantation, washed with diethyl
ether and dried in vacuo: yield 130 mg (86%). IR (Nujol): ν-
center, as a consequence of the presence of the strong
donor phosphine and the chlorine ligands in the com-
plex, and the large steric hindrance experienced by the
triisopropylphosphine groups, which are mutually cis
disposed. This mixture allows access to reactive points
on the cyclopentadienylosmium center by activation of
the Os-P and Os-Cl bonds. In polar solvents such as
methanol and acetone, the dissociation of the chlorine
ligand occurs and the resulting metallic fragment is
capable of activating a methyl C-H bond of a triisopro-
(OsH) 2108 cm-1; ν(PF6) 838 cm-1 1H NMR (300 MHz, CD2-
.
Cl2, 293 K): δ 5.44 (s, 10 H, Cp), 3.22, 3.07 (both m, 1 H each),
2.76 (dt, J (HH) ) 9.9 Hz, J (PH) ) 29.7 Hz, 1 H), 2.54-2.04
(m, 4 H), 2.42 (m, 6 H, PCH PiPr3), 2.17, 1.97, 1.55 (all m, 1 H
each), 1.51-1.13 (m, 66 H, CH3), -13.81 (dd, J (PH) ) 36.0
Hz, J (PH) ) 27.9 Hz, 1 H, OsH), -13.98 (dd, J (PH) ) 38.0
Hz, J (PH) ) 25.4 Hz, 1 H, OsH). 31P{1H} NMR (121.42 MHz,
CD2Cl2, 293 K): δ 8.0 (d, J (PP) ) 20.5 Hz, vt in off resonance,
PiPr3), 4.4 (d, J (PP) ) 23.9 Hz, vt in off resonance, PiPr3), -33.1
(d, J (PP) ) 20.5 Hz, vt in off resonance, PiPr2CH(CH3)CH2),
-37.4 (d, J (PP) ) 23.9 Hz, vt in off resonance, PiPr2CH(CH3)-
CH2), -144.8 (sept, J (FP) ) 713.6 Hz, PF6). 13C{1H} NMR
(75.42 MHz, CD2Cl2, 293 K, plus APT): δ 84.2 (+, s, Cp), 84.1
(+, s, Cp), 49.9 (+, d, J (PC) ) 35.6 Hz, PiPr2CHCH3), 46.9 (+,
d, J (PC) ) 36.0 Hz, PiPr2CHCH3), 34.8 (+, d, J (PC) ) 23.5
Hz, PCH PiPr2), 34.7 (+, d, J (PC) ) 22.5 Hz, PCH PiPr2), 31.1
(+, d, J (PC) ) 27.8 Hz, PCH PiPr3), 29.3 (+, d, J (PC) ) 28.3
Hz, PCH PiPr3), 28.7 (+, d, J (PC) ) 21.0 Hz, PCH PiPr2), 26.4
(+, d, J (PC) ) 19.6 Hz, PCH PiPr2), 24.7 (+, d, J (PC) ) 6.5
Hz, PCH(CH3)CH2), 24.2 (+, d, J (PC) ) 6.3 Hz, PCH(CH3)-
CH2), 21.7 (+, d, J (PC) ) 3.8 Hz, PCCH3), 20.9, 20.8 (+, both
s, PCCH3), 20.6 (+, d, J (PC) ) 3.0 Hz, PCCH3), 20.3 (+, s,
PCCH3), 20.2 (+, d, J (PC) ) 2.2 Hz, PCCH3), 19.1 (+, d, J (PC)
) 5.2 Hz, PCCH3), 18.8, 18.1 (+, both s, PCCH3), -36.9 (-,
dd, J (PC) ) 37.1 Hz, J (PC) ) 9.3 Hz, OsCH2), -37.4 (-, dd,
J (PC) ) 36.1 Hz, J (PC) ) 9.2 Hz, OsCH2). Anal. Calcd for
pylphosphine to give OsH(η5-C5H5){CH2CH(CH3)Pi-
Pr2}(PiPr3)]+. On the other hand, in pentane and
toluene, the splitting of a phosphorous-osmium bond
is favored and the reactions of Os(η5-C5H5)Cl(PiPr3)2
with olefins and alkynes lead to π-olefin and π-alkyne
complexes. When the alkynes are 1-ethynyl-1-cyclo-
hexanol and 2-methyl-3-butyn-2-ol, the π-alkyne com-
plexes evolve by loss of a water molecule into the
corresponding alkenylvinylidene compounds, in agree-
ment with the rich-electron character of the metallic
center. These alkenylvinylidene complexes afford alk-
enylcarbyne derivatives by protonation with HBF4‚OEt2.
In conclusion, we report the preparation of a labile
cyclopentadienylosmium synthetic precursor, which is
allowing the development of extensive organometallic
chemistry in a little-known field.
Exp er im en ta l Section
P h ysica l Mea su r em en ts. Infrared spectra were recorded
as Nujol mulls on polyethylene sheets using a Nicolet 550
spectrometer. NMR spectra were recorded on a Varian UNITY
300, Varian GEMINI 2000 300 MHz, or on a Bruker ARX 300
spectrometer. 1H and 13C{1H} chemical shifts were measured
relative to partially deuterated solvent peaks but are reported
relative to tetramethylsilane. 31P{1H} chemical shifts are
reported relative to H3PO4 (85%). Coupling constants J and
N (N ) J (PH) + J (P′H)) are given in Hertz. C, H analyses
were carried out in a Perkin-Elmer 2400 CHNS/O analyzer.
Mass spectra analyses were performed with a VG Auto Spec
instrument. The ions were produced, FAB+ mode, with the
standard Cs+ gun at ca. 30 kV, and 3-nitrobenzyl alcohol
(NBA) was used as the matrix.
C
23H47F6OsP3: C, 38.32; H, 6.57. Found: C, 38.03; H, 6.21.
MS (FAB+): m/ e 577 (M+).
P r ep a r a tion of OsH(η5-C5H5)(P iP r 3)2 (4). A solution of
Os(η5-C5H5)Cl(PiPr3)2 (150 mg, 0.25 mmol) in 10 mL of toluene
was treated with 94 mg (2.5 mmol) of NaBH4 and, after 3 min,
dropwise with 1.0 mL of methanol. After the mixture was
stirred for 15 min at room temperature, the solution was
filtered through Kieselguhr. The solvent was removed to
dryness, and 10 mL of pentane was added. The yellow solution
was filtered through Kieselguhr and concentrated to dryness.
The product was isolated as a yellow oil. IR (toluene): ν(OsH)
2075 cm-1
.
1H NMR (300 MHz, C6D6, 293 K): δ 4.59 (s, 5 H,
Cp), 1.91 (m, 6 H, PCH), 1.14 (dvt, J (HH) ) 6.6 Hz, N ) 12.6
Hz, 36 H, PCCH3), -16.10 (t, J (PH) ) 31.1 Hz, 1 H, OsH).
31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 29.4 (s, d in off
resonance). MS (FAB+): m/ e 579 (M+ + H).
Syn th esis. All reactions were carried out with the exclu-
sion of air using standard Schlenk techniques. Solvents were
dried by known procedures and distilled under argon prior to
use. The complex OsH2Cl2(PiPr3)2 (1) was prepared according
to the literature method.6b
P r ep a r a tion of [OsH2(η5-C5H5)(P iP r 3)2]BF 4 (5). A solu-
tion of Os(η5-C5H5)Cl(PiPr3)2 (150 mg, 0.25 mmol) in 10 mL of
toluene was treated with 94 mg (2.5 mmol) of NaBH4 and, after
3 min, dropwise with 1.0 mL of methanol. After the mixture
was stirred for 15 min at room temperature, the solution was
filtered through Kieselguhr. The solvent was removed to
dryness, and 10 mL of pentane was added. The yellow solution
was filtered through Kieselguhr and concentrated to dryness.
Over a diethyl ether solution (5 mL) of the yellow oil obtained,
33.5 µL (0.25 mmol) of HBF4 was added, and a white solid
precipitated. The white solid was separated by decantation,
washed with diethyl ether, and dried in vacuo: yield 126.5
mg (76%). IR (Nujol): ν(OsH) 2146, 2203 cm-1; ν(BF4) 1030-
P r ep a r a tion of Os(η5-C5H5)Cl(P iP r 3)2 (2). A solution of
OsH2Cl2(PiPr3)2 (1.2 g, 2.04 mmol) in 30 mL of toluene was
treated with 566 mg (2.04 mmol) of cyclopentadienylthallium.
The mixture was stirred for 2 h at room temperature and
filtered through Kieselguhr. The resulting orange solution was
concentrated to dryness. The product was extracted with 60
mL of pentane, which was filtered through Kieselguhr. The
solution was concentrated to about 4 mL, and an orange
precipitate was obtained. The solid was separated by decanta-
tion, and 3 mL of pentane was added. The suspension was
stored at -78 °C for 30 min. The orange solid was separated
by decantation and dried in vacuo: yield 650 mg (52%). 1H
NMR (300 MHz, C6D6, 293 K): δ 4.73 (s, 5 H, Cp), 2.46 (m, 6
H, PCH), 1.22 (dvt, J (HH) ) 7.2 Hz, N ) 12.0 Hz, 18 H,
PCCH3), 1.13 (dvt, J (HH) ) 7.2 Hz, N ) 12.0 Hz, 18 H,
PCCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ -1.2
(s). Anal. Calcd for C23H47ClOsP2: C, 45.19; H, 7.75. Found:
C, 44.95; H, 7.20. MS (FAB+): m/ e 577 (M+ - Cl).
1081 cm-1
.
1H NMR (300 MHz, CDCl3, 293 K): δ 5.48 (s, 5
H, Cp), 2.06 (m, 6 H, PCH), 1.21 (dd, J (HH) ) 7.0 Hz, J (PH)
) 14.2 Hz, 36 H, PCCH3), -14.26 (t, J (PH) ) 28.8 Hz, 2 H,
OsH). 31P{1H} NMR (121.42 MHz, CDCl3, 293 K): δ 32.2 (s,
t in off resonance). Anal. Calcd for C23H49BF4OsP2: C, 41.56;
H, 7.43. Found: C, 42.06; H, 7.28. MS (FAB+): m/ e 579 (M+).
P r ep a r a tion of Os(η5-C5H5)Cl{P (OMe)3}(P iP r 3) (6). A
suspension of Os(η5-C5H5)Cl(PiPr3)2 (65 mg, 0.11 mmol) in 8
mL of pentane was treated with 12.5 µL (0.11 mmol) of
P r ep a r a t ion of [OsH (η5-C5H 5){CH2CH (CH3)P iP r 2}-
(P iP r 3)]P F 6 (3). A solution of Os(η5-C5H5)Cl(PiPr3)2 (128 mg,

Preparation of Cyclopentadienylosmium Compounds
Organometallics, Vol. 16, No. 21, 1997 4665
trimethyl phosphite. The mixture was stirred at room tem-
perature for 7 h. The yellow solution was concentrated to
dryness. Addition of 3 mL of pentane caused the precipitation
of a yellow solid, which was separated by decantation and dried
in vacuo: yield 22.8 mg (36%). 1H NMR (300 MHz, C6D6, 293
K): δ 4.80 (s, 5 H, Cp), 3.44 (d, J (PH) ) 11.1 Hz, 9 H, OCH3),
2.61 (m, 3 H, PCH), 1.19 (dd, J (HH) ) 7.2 Hz, J (PH) ) 12.9
Hz, 9 H, PCCH3), 1.08 (dd, J (HH) ) 7.2 Hz, J (PH) ) 12.9 Hz,
9 H, PCCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ
103.7 (d, J (PP) ) 34.6 Hz, P(OMe)3), 14.4 (d, J (PP) ) 34.6 Hz,
PiPr3). Anal. Calcd for C17H35ClO3OsP2: C, 35.50; H, 6.13.
Found: C, 35.73; H, 6.06. MS (FAB+): m/ e 577 (M+), 541 (M+
- Cl).
4.3 Hz, J (XB) ) 4.3 Hz, 2 H, dCH), 4.26-3.93 (m, 4 H, CH2),
2.07 (m, 3 H, PCH), 1.14, 1.08 (both t, J (HH) ) 7.2 Hz, 3 H
each, CH3), 0.92 (dd, J (HH) ) 7.3 Hz, J (PH) ) 14.0 Hz, 9 H,
PCCH3), 0.82 (dd, J (HH) ) 7.1 Hz, J (PH) ) 11.8 Hz, 9 H,
PCCH
3). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 2.0 (s).
13C{1H} NMR (75.42 MHz, C6D6, 293 K): δ 176.7, 176.5 (both
s, CO2CH2CH3), 86.9 (d, J (PC) ) 2.3 Hz, Cp), 60.4, 59.9 (both
s, CO2CH2CH3), 34.5, 29.8 (both br s, dCH), 23.6 (d, J (PC) )
26.6 Hz, PCH), 20.6 (s, PCCH3), 19.2 (d, J (PC) ) 2.3 Hz,
PCCH3), 14.8, 14.3 (both s, CO2CH2CH3). Anal. Calcd for
C
22H38ClO4OsP: C, 42.47; H, 6.14. Found: C, 42.87; H, 5.89.
MS (FAB+): m/ e 625 (M+ + 2 H), 589 (M+ - Cl + H).
P r epar ation of Os(η5-C5H5)Cl{η2-HCtCsC(OH)(CH2)4C-
H2}(P iP r 3) (10). A suspension of Os(η5-C5H5)Cl(PiPr3)2 (125
mg, 0.20 mmol) in 15 mL of pentane was treated with 28 mg
(0.20 mmol) of 1-ethynyl-1-cyclohexanol. After the mixture
was stirred for 30 min at room temperature, the red solution
obtained was filtered through Kieselguhr and concentrated to
dryness. Addition of 3 mL of pentane caused the precipitation
of a brown solid, which was separated by decantation and dried
in vacuo: yield 56.2 mg (52%). IR (toluene): ν(CtC) 1869
2
5
P r ep a r a tion of Os(η -C5H5)Cl{η -CH2dCHC(O)CH 3}-
(P iP r 3) (7). A solution of Os(η5-C5H5)Cl(PiPr3)2 (125 mg, 0.20
mmol) in 8 mL of toluene was treated with 18.4 µL (0.22 mmol)
of methyl vinyl ketone. The mixture was heated at 85 °C for
15 h. After the sample was cooled to room temperature, the
yellow solution obtained was filtered through Kieselguhr and
concentrated to dryness. Addition of pentane caused the
precipitation of a yellow solid, which was separated by
decantation, washed with 3 mL of pentane, and dried in
cm-1
.
1H NMR (300 MHz, C6D6, 293 K): δ 5.42 (br s, 1 H,
1
vacuo: yield 86.8 mg (83%). IR (Nujol): ν(CO) 1661 cm-1. H
OH), 4.99 (s, 5 H, Cp), 3.88 (d, J (PH) ) 9.0 Hz, 1 H, tCH),
2.39 (m, 3 H, PCH), 2.12-1.20 (m, 10 H, Cy), 0.93 (dd, J (HH)
) 7.2 Hz, J (PH) ) 12.9 Hz, 18 H, PCCH3). 31P{1H} NMR
(121.42 MHz, C6D6, 293 K): δ 9.5 (s). 13C{1H} NMR (75.42
MHz, C6D6, 293 K, plus APT): δ 79.8 (+, d, J (PC) ) 2.3 Hz,
Cp), 71.8 (-, d, J (PC) ) 10.6 Hz, tC-), 53.3 (+, br, tCH),
39.9 (-, s, -C(OH)), 26.0, 25.3, 23.5, 23.1 (-, all s, Cy), 24.1
(+, d, J (PC) ) 28.1 Hz, PCH), 19.6 (+, s, PCCH3). MS
(FAB+): m/ e 541 (M+ - Cl). Elemental analysis was not
available because of the high instability of the product out of
the argon atmosphere.
NMR (300 MHz, C6D6, 293 K): δ 4.85 (s, 5 H, Cp), 4.17, 4.04
(AB part of ABMX system, J (AB) ) 9.4 Hz, J (MA) ) 2.5 Hz,
J (MB) ) 6.5 Hz, J (XA) ) 2.5 Hz, J (XB) ) 0 Hz, 2 H, trans
protons, dCH), 2.53 (s, 3 H, CH3), 2.26 (M part of ABMX
system, J (BM) ) 6.5 Hz, J (AM) ) 2.5 Hz, J (XM) ) 12.6 Hz, 1
H, dCH2), 2.09 (m, 3 H, PCH), 0.93 (dd, J (HH) ) 7.2 Hz, J (PH)
) 13.8 Hz, 9 H, PCCH3), 0.76 (dd, J (HH) ) 7.2 Hz, J (PH) )
11.7 Hz, 9 H, PCCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293
K): δ 5.7 (s). 13C{1H} NMR (75.42 MHz, C6D6, 293 K, plus
APT): δ 205.9 (-, s, sCO), 84.4 (+, d, J (PC) ) 2.2 Hz, Cp),
46.7 (+, d, J (PC) ) 1.4 Hz, dCH), 30.9 (+, s, CH3), 22.9 (+, d,
J (PC) ) 27.1 Hz, PCH), 20.4 (+, s, PCCH3), 19.6 (-, d, J (PC)
) 5.0 Hz, dCH2), 19.2 (+, d, J (PC) ) 3.2 Hz, PCCH3). Anal.
Calcd for C18H32ClOOsP: C, 41.49; H, 6.19. Found: C, 40.94;
H, 6.19. MS (FAB+): m/ e 523 (M+), 487 (M+ - Cl).
P r ep a r a tion of Os(η5-C5H5)Cl{η2-HCtC-C(OH)(CH3)2}-
(P iP r 3) (11). A suspension of Os(η5-C5H5)Cl(PiPr3)2 (125 mg,
0.20 mmol) in 10 mL of pentane was treated with 21.2 µL (0.21
mmol) of 2-methyl-3-butyn-2-ol. The color of the solution
changed from orange to red, and a brown solid began to
precipitate. After the mixture was stirred for 30 min at room
temperature, the brown solid was separated by decantation,
washed with 4 mL of pentane, and dried in vacuo: yield 81.5
P r ep a r a t ion of Os(η5-C5H 5)Cl{η2-C(CO2CH 3)tCCO2-
CH3}(P iP r 3) (8). A solution of Os(η5-C5H5)Cl(PiPr3)2 (118 mg,
0.19 mmol) in 8 mL of toluene was treated with 23.6 µL (0.19
mmol) of dimethyl acetylenedicarboxylate and stirred at room
temperature for 45 min. After removal of the solvent, the
addition of pentane caused the precipitation of a brown solid.
The solid was separated by decantation, washed with 4 mL of
pentane and dried in vacuo: yield 82.3 mg (73%). IR (Nujol):
mg (76%). IR (Nujol): ν(OH) 3162 cm-1 1H NMR (300 MHz,
.
C6D6, 293 K): δ 5.26 (s, 1 H, OH), 4.97 (s, 5 H, Cp), 3.72 (d,
J (PH) ) 8.4 Hz, 1 H, tCH), 2.38 (m, 3 H, PCH), 1.90 (br, 6 H,
CH3), 0.92 (dd, J (HH) ) 7.5 Hz, J (PH) ) 12.9 Hz, 18 H,
PCCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 9.5 (s).
13C{1H} NMR (75.42 MHz, C6D6, 293 K): 80.2 (s, Cp), 69.1
(br, tC-), 49.6 (br, tCH), 35.1 (br, -C(OH)), 24.3 (d, J (PC)
) 27.7 Hz, PCH), 22.7 (s, CH3), 19.8 (s, PCCH3), 14.2 (s, CH3).
Anal. Calcd for C19H34ClOOsP: C, 42.64; H, 6.40. Found: C,
42.78; H, 6.42. MS (FAB+): m/ e 501 (M+ - Cl)
ν(CtC) 1825 cm-1; ν(CdO) 1705, 1683 cm-1
.
1H NMR (300
MHz, C6D6, 293 K): δ 5.20 (s, 5 H, Cp), 3.59, 3.38 (both s, 3 H
each, OCH3), 2.46 (m, 3 H, PCH), 1.05 (dd, J (HH) ) 7.2 Hz,
J (PH) ) 13.9 Hz, 9 H, PCCH3), 0.88 (dd, J (HH) ) 7.2 Hz,
J (PH) ) 12.3 Hz, 9 H, PCCH3). 31P{1H} NMR (121.42 MHz,
C6D6, 293 K): δ 17.3 (s). 13C{1H} NMR (75.42 MHz, C6D6, 293
K): δ 164.1, 161.2 (both s, CO2CH3), 84.2 (d, J (PC) ) 3.2, Cp),
70.2 (br s, -Ct), 69.8 (d, J (PC) ) 8.3 Hz, -Ct), 51.7, 51.5
(both s, CO2CH3), 22.8 (d, J (PC) ) 28.0 Hz, PCH), 19.8 (s,
PCCH3), 18.6 (d, J (PC) ) 3.0 Hz, PCCH3). Anal. Calcd for
P r ep a r a tion of Os(η5-C5H5)Cl{dCdCHsCdCH(CH2)3C-
H2}(P iP r 3) (12). A solution of Os(η5-C5H5)Cl(PiPr3)2 (150 mg,
0.25 mmol) in 8 mL of toluene was treated with 33.5 mg (0.27
mmol) of 1-ethynyl-1-cyclohexanol. The mixture was heated
at 85 °C for 15 h, and a red solution was obtained. The
resulting red solution was cooled to room temperature and
filtered through Kieselguhr. The solution was concentrated
to dryness, and 8 mL of methanol was added. The solvent
was partially evaporated until a red solid began to precipitate,
and the suspension was stored at -78 °C for 1 h. The red
solid was separated by decantation and dried in vacuo: yield
C
20H32ClO4OsP: C, 40.50; H, 5.43. Found: C, 40.08; H, 5.48.
MS (FAB+): m/ e 558 (M+ - H - Cl).
P r ep a r a t ion of Os(η5-C5H 5)Cl{η2-(Z)-CH (CO2C2H 5)d
CHCO2C2H5}(P iP r 3) (9). A solution of Os(η5-C5H5)Cl(PiPr3)2
(125 mg, 0.20 mmol) in 10 mL of toluene was treated with
64.5 µL (0.60 mmol) of ethyl diazoacetate. The sample was
stirred at room temperature for 15 h. The dark yellow solution
obtained was filtered through Kieselguhr and concentrated to
dryness. Twenty milliliters of pentane was added, and the
yellow solution was filtered through Kieselguhr and concen-
trated until a yellow solid began to precipitate. After the
suspension was kept at -78 °C for 1 h, the yellow solid was
separated by decantation and dried in vacuo: yield 64.7 mg
69.6 mg (50%). IR (Nujol): ν(dCdC) 1635, 1613 cm-1
.
1H
NMR (300 MHz, CDCl3, 293 K): δ 5.47 (s, 5 H, Cp), 4.83 (br
s, 1 H, CdCH(CH2)3CH2), 2.76 (m, 3 H, PCH), 2.44 (br, 2 H,
-CH2 Cy), 2.30 (s, 1 H, dCdCH), 2.05 (m, 2 H, -CH2 Cy),
1.60 (m, 2 H, -CH2 Cy), 1.52 (m, 2 H, -CH2 Cy), 1.19 (dd,
J (HH) ) 7.2 Hz, J (PH) ) 14.4 Hz, 9 H, PCCH3), 1.14 (dd,
J (HH) ) 7.2 Hz, J (PH) ) 14.4 Hz, 9 H, PCCH3). 31P{1H} NMR
(121.42 MHz, CDCl3, 293 K): δ 18.5 (s). 13C{1H} NMR (75.42
(52%). IR (Nujol): ν(CO) 1718, 1702 cm-1; ν(CdC) 1622 cm-1
.
1H NMR (300 MHz, C6D6, 293 K): δ 5.40 (s, 5 H, Cp), 4.35,
4.31 (AB part of ABX spin system, J (AB) ) 9.9 Hz, J (XA) )

4666 Organometallics, Vol. 16, No. 21, 1997
Ta ble 2. Cr ysta l Da ta a n d Da ta Collection a n d Refin em en t for
Esteruelas et al.
[Os(η5-C5H5)Cl{tCsCHdC(CH2)4CH2}(P iP r 3)]BF 4 (16)
Crystal Data
formula
mol wt
C
22H37BClF4OsP
c, Å
13.250(2)
87.27(2)
68.68(1)
85.57(1)
1276.6(3)
2
644.95
R, deg
â, deg
γ, deg
V, Å3
Z
color and habit
cryst size, mm
symmetry
space group
a, Å
orange, irregular prism
0.21 × 0.13 × 0.25
triclinic
P1h (No. 2)
9.805(1)
D
calcd, g cm-3
1.678
b, Å
10.582(2)
Data Collection and Refinement
diffractometer
four-circle Siemens-STOE AED
0.710 73; bisecting geometry
graphite oriented
5.20
ω/2θ
3 e 2θ e 50
200
no. of data collcd
no. of unique data
no. of params refined
R1a (F2 > 2σ(F2))
wR2b (all data)
7043
λ(Mo KR), Å; technique
monochromator
µ, mm-1
scan type
2θ range, deg
temp, K
4502 (Rint ) 0.0335)
272
0.0412
0.0964
1.034
Sc (all data)
a
b
2
2
R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. wR2(F2) ) {∑[w(Fo - Fc2)2]/∑[w(Fo2)2]}1/2
.
c 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.
MHz, CDCl3, 293 K, plus APT): δ 292.7 (-, d, J (PC) ) 13.4
Hz, OsdC), 126.2 (-, s, CdCH(CH2)3CH2), 118.7 (+, s, CdCH-
(64%). IR (Nujol): ν(dCdC) 1619 cm-1; ν(Ph) 1592 cm-1 1H
.
NMR (300 MHz, C6D6, 293 K): δ 7.48 (d, J (HH) ) 7.5 Hz, 2
H, o-Ph), 7.25 (vt, J (HH) ) 7.8 Hz, J (HH) ) 7.8 Hz, 2 H, m-Ph),
6.83 (vt, J (HH) ) 7.5 Hz, J (HH) ) 7.5 Hz, 1 H, p-Ph), 5.11 (s,
5 H, Cp), 2.83 (s, 1 H, dCH), 2.57 (m, 3 H, PCH), 0.99 (dd,
J (HH) ) 7.2 Hz, J (PH) ) 13.8 Hz, 9 H, PCCH3), 0.92 (dd,
J (HH) ) 7.5 Hz, J (PH) ) 13.5 Hz, 9 H, PCCH3). 31P{1H} NMR
(121.42 MHz, C6D6, 293 K): δ 19.4 (s). 13C{1H} NMR (75.42
MHz, C6D6, 293 K): δ 291.6 (d, J (PC) ) 13.6 Hz, OsdC), 131.0,
128.5, 125.0, 124.3 (all s, Ph), 116.1 (s, dCH), 87.8 (d, J (PC)
) 2.3 Hz, Cp), 24.95 (d, J (PC) ) 29.5 Hz, PCH), 20.1 (s,
PCCH3), 19.7 (d, J (PC) ) 1.0 Hz, PCCH3). Anal. Calcd for
(CH2)3CH2), 114.5 (+, s, dCdCH), 87.3 (+, d, J (PC) ) 2.3 Hz,
Cp), 28.0, 24.9, 22.9, 22.7 (-, all s, Cy), 24.6 (+, d, J (PC) )
29.5 Hz, PCH), 19.5, 19.4 (+, both s, PCCH3). Anal. Calcd
for C22H36ClOsP: C, 47.42; H, 6.51. Found: C, 47.59; H, 5.97.
MS (FAB+): m/ e 558 (M+).
P r ep a r a tion of Os(η5-C5H5)Cl{dCdCHsC(CH3)dCH2}-
(P iP r 3) (13). Meth od A. A solution of Os(η5-C5H5)Cl(PiPr3)2
(125 mg, 0.20 mmol) in 8 mL of toluene was treated with 21.2
µL (0.21 mmol) of 2-methyl-3-butyn-2-ol. The mixture was
heated at 85 °C for 20 h, and a red solution was obtained. The
resulting red solution was cooled to room temperature and
filtered through Kieselguhr. The solution was concentrated
to dryness, and 20 mL of pentane was added. The solution
was filtered through Kieselguhr. The solvent was partially
evaporated until a red solid began to precipitate, and the
suspension was stored at -78 °C for 1 h. The red solid was
separated by decantation and dried in vacuo: yield 65.1 mg
(63%).
C
22H32ClOsP: C, 47.77; H, 5.83. Found: C, 47.64; H, 6.09.
MS (FAB+): m/ e 554 (M+).
P r ep a r a tion of [Os(η5-C5H5)Cl{tCsCHdC(CH2)4CH2}-
(P iP r 3)]BF 4 (16). A solution of Os(η5-C5H5)Cl{dCdCHs
CdCH(CH2)3CH2}(PiPr3) (37.6 mg, 0.07 mmol) in 0.5 mL of
CDCl3 was treated with 9.2 µL (0.07 mmol) of HBF4. After 2
min at room temperature, the NMR spectra showed only the
presence
of
the
compound
[Os(η5-C5H5)Cl{tCs
Meth od B. A suspension of Os(η5-C5H5)Cl(PiPr3)2 (150 mg,
0.25 mmol) in 20 mL of pentane was treated with 23.4 µL (0.25
mmol) of 2-methyl-1-buten-3-yne. The mixture was stirred at
room temperature for 3 h, and a red solution was obtained,
which was filtered through Kieselguhr. The solvent was
partially evaporated until a red solid began to precipitate, and
the suspension was stored at -78 °C for 1 h. The red solid
was separated by decantation and dried in vacuo: yield 82.7
CHdC(CH2)4CH2}(PiPr3)]BF4. The red solution was then
transferred to a Schlenk tube and concentrated to dryness.
The addition of diethyl ether caused the precipitation of a red
solid, which was separated by decantation, washed with
diethyl ether, and dried in vacuo: yield 40.6 mg (90%). IR
(Nujol): ν(BF4) 1103-1020 cm-1 1H NMR (300 MHz, CDCl3,
.
293 K): δ 6.14 (s, 5 H, Cp), 5.59 (s, 1 H, dCH), 2.81 (br, 2 H,
-CH2 Cy), 2.65 (m, 3 H, PCH), 2.29 (br, 2 H, -CH2 Cy), 1.81
(br, 2 H, -CH2 Cy), 1.62 (br, 4 H, -CH2 Cy),1.29 (dd, J (HH)
) 6.9 Hz, J (PH) ) 15.0 Hz, 9 H, PCCH3), 1.27 (dd, J (HH) )
6.6 Hz, J (PH) ) 15.3 Hz, 9 H, PCCH3). 31P{1H} NMR (121.42
MHz, CDCl3, 293 K): δ 33.6 (s). 13C{1H} NMR (75.42 MHz,
CDCl3, 293 K, plus APT): δ 290.0 (-, d J (PC) ) 10.1 Hz,
mg (64%). IR (Nujol): ν(dCdC) 1613 cm-1
.
1H NMR (300
MHz, C6D6, 293 K): δ 5.09 (s, 5 H, Cp), 4.55, 4.05 (both s, 1 H
each, dCH2), 2.75 (s, 1 H, dCH), 2.58 (m, 3 H, PCH), 2.21 (s,
3 H, CH3), 1.05 (dd, J (HH) ) 7.2 Hz, J (PH) ) 13.8 Hz, 9 H,
PCCH3), 0.92 (dd, J (HH) ) 7.2 Hz, J (PH) ) 13.5 Hz, 9 H,
PCCH3). 31P{1H} NMR (121.42 MHz, C6D6, 293 K): δ 19.1
(s). 13C{1H} NMR (75.42 MHz, C6D6, 293 K, plus APT): δ
291.4 (-, d, J (PC) ) 13.2 Hz, OsdC), 134.2 (-, s, CHsCdCH2),
119.3 (+, s, CHsCdCH2), 103.7 (-, s, CHsCdCH2), 87.6 (+,
d, J (PC) ) 1.5 Hz, Cp), 24.9 (+, d, J (PC) ) 29.4 Hz, PCH),
22.7 (+, s, CH3), 19.6, 19.5 (+, both s, PCCH3). Anal. Calcd
for C19H32ClOsP: C, 44.13; H, 6.23. Found: C, 44.41; H, 6.50.
MS (FAB+): m/ e 519 (M+ + H).
OstC), 187.2 (-, s, CHdC(CH2)4CH2), 134.6 (+, s, CHdC-
(CH2)4CH2), 94.1 (+, s, Cp), 37.4, 34.1, 28.4, 28.3 (-, all s, CH2
Cy), 27.3 (+, d, J (PC) ) 29.4 Hz, PCH), 25.1 (-, s, -CH2 Cy),
19.5 (+, s, PCCH3), 19.1 (+, d, J (PC) ) 2.8 Hz, PCCH3). Anal.
Calcd for C22H37BF4ClOsP: C, 40.97; H, 5.78. Found: C, 41.09;
H, 5.70. MS (FAB+): m/ e 559 (M+).
P r ep a r a tion of Os(η5-C5H5)Cl{dCdCHP h }(P iP r 3) (15).
A solution of Os(η5-C5H5)Cl(PiPr3)2 (150 mg, 0.25 mmol) in 20
mL of pentane was treated with 25.0 µL (0.25 mmol) of
phenylacetylene. The mixture was stirred at room tempera-
ture for 3 h. The red solution obtained was filtered through
Kieselguhr and concentrated to dryness. Addition of 4 mL of
pentane caused the precipitation of a red solid, which was
separated by decantation and dried in vacuo: yield 88.5 mg
P r ep a r a t ion of [Os(η5-C5H 5)Cl{tCsCHdC(CH3)2}-
(P iP r 3)]BF 4 (17). A solution of Os(η5-C5H5)Cl{dCdCHsC-
(CH3)dCH2}(PiPr3) (31.3 mg, 0.06 mmol) in 0.5 mL of CD2Cl2
was treated with 8.2 µL (0.06 mmol) of HBF4. After 2 min at
room temperature, the NMR spectra showed only the presence
of the compound [Os(η5-C5H5)Cl{tCsCHdC(CH3)2}(PiPr3)]-
BF4. The product was isolated as a red oil. 1H NMR (300
MHz, CD2Cl2, 293 K): δ 6.12 (s, 5 H, Cp), 5.45 (br s, 1 H, dCH),

Preparation of Cyclopentadienylosmium Compounds
Organometallics, Vol. 16, No. 21, 1997 4667
2.66 (m, 3 H, PCH), 2.32, 2.01 (both s, 3 H each, CH3), 1.34-
1.24 (m, 18 H, PCCH3). 31P{1H} NMR (121.42 MHz, CD2Cl2,
293 K): δ 36.0 (s). 13C{1H} NMR (75.42 MHz, CDCl3, 293 K,
plus APT): δ 289.8 (-, d, J (PC) ) 10.6 Hz, OstC), 181.8 (-,
s, sCHdC), 137.9 (+, s, sCHdC), 94.6 (+, s, Cp), 27.8 (+, d,
J (PC) ) 29.9 Hz, PCH), 27.5, 24.1 (+, both s, CH3), 19.0 (+, s,
PCCH3), 19.4 (+, d, J (PC) ) 3.0 Hz, PCCH3). MS (FAB+): m/ e
519 (M+).
(Rmerg ) 0.03) were used in the refinement. Three standard
reflections were monitored at periodic intervals throughout
data collection: no significant variations were observed. All
data were corrected for absorption using a semiempirical
method.38 The structure was solved by Patterson (Os atom,
SHELXTL-PLUS39) and conventional Fourier techniques, and
refined by full-matrix least-squares on F2 (SHELXL9340).
Anisotropic parameters were used in the last cycles of refine-
ment for all non-hydrogen atoms. The hydrogen atoms were
calculated (C-H ) 0.96 Å) and refined riding on carbon atoms
with a common isotropic thermal parameter. Atomic scatter-
ing factors, corrected for anomalous dispersion for Os and P,
were implemented by the program. The refinement converged
to R1 ) 0.0412 (F2 > 2σ(F2)) and wR2 ) 0.0964 (all data), with
weighting parameters x ) 0.0562 and y )0.
All assays for preparing monocrystals of 9 were unsuccess-
ful. The only apparently suitable crystal was grown in a
saturated solution of complex 9 in pentane left at 253 K for
several days. The structure was solved by Patterson (Os atom,
SHELXTL-PLUS39) and conventional Fourier techniques and
refined by full-matrix least-squares on F2 (SHELXL9340).
Further refinement, with anisotropic thermal parameters, was
not allowed because of the low quality of the data.
P r ep a r a tion of [Os(η5-C5H5)Cl(tCsCH2P h )(P iP r 3)]BF 4
(18). A solution of Os(η5-C5H5)Cl{dCdCHPh}(PiPr3) (37.9 mg,
0.07 mmol) in 0.5 mL of CDCl3 was treated with 9.4 µL (0.07
mmol) of HBF4. After 2 min at room temperature, the color
of the solution changed from red to green and the NMR spectra
showed only the presence of the compound [Os(η5-
C5H5)Cl(tCsCH2Ph)(PiPr3)]BF4. The green solution was then
transferred to a Schlenk tube and concentrated to dryness.
The addition of diethyl ether caused the precipitation of a
green solid, which was separated by decantation, washed with
diethyl ether, and dried in vacuo: yield 39.5 mg (90%). IR
(Nujol): ν(BF4) 1061 cm-1
.
1H NMR (300 MHz, CDCl3, 293
K): δ 7.39-7.30 (m, 5 H, Ph), 6.10 (s, 5 H, Cp), 3.92, 3.52 (AB
spin system, J (AB) ) 19.9 Hz, 2 H, -CH2), 2.61 (m, 3 H, PCH),
1.30 (dd, J (HH) ) 6.9 Hz, J (PH) ) 10.2 Hz, 9 H, PCCH3), 1.25
(dd, J (HH) ) 7.2 Hz, J (PH) ) 11.4 Hz, 9 H, PCCH3). 31P{1H}
NMR (121.42 MHz, CDCl3, 293 K): δ 38.3 (s). 13C{1H} NMR
(75.42 MHz, CDCl3, 293 K, plus APT): δ 304.9 (-, d, J (PC) )
9.8 Hz, OstC), 129.9, 129.7, 128.7 (+, all s, Ph), 127.9 (-, s,
Ack n ow led gm en t. We thank the DGICYT (Project
No. PB 95-0806, Programa de Promocio´n General del
Conocimiento).
C
ipso Ph), 95.0 (+, s, Cp), 62.08 (-, s, CH2), 27.4 (+, d, J (PC) )
29.5 Hz, PCH), 20.0 (+, s, PCCH3), 19.2 (+, d, J (PC) ) 2.7 Hz,
PCCH3). Anal. Calcd for C22H33BF4ClOsP: C, 41.22; H, 5.14.
Found: C, 41.19; H, 5.44. MS (FAB+): m/ e 555 (M+).
X-r a y Str u ctu r e An a lysis of Com p lex [Os(η5-C5H5)Cl-
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 study, bond distances and angles, and interatomic
distances for 16 (8 pages). Ordering information is given on
any current masthead page.
{tCsCHdC(CH2)4CH2}(P iP r 3)]BF 4 (16). Crystals suitable
for the X-ray diffraction study were obtained by slow diffusion
of ether into a concentrated solution of 16 in CH2Cl2.
A
summary of the crystal data and refinement parameters is
reported in Table 2. The orange irregular crystal, of ap-
proximate dimensions 0.21 × 0.13 × 0.25 mm, was glued on a
glass fiber and mounted on a Siemens-STOE AED-2 diffrac-
tometer. A group of 87 reflections in the range 20° e 2θ e
35° were carefully centered at 200 K and used by least-squares
methods to obtain the unit cell dimensions. A total of 7043
reflections were measured, from which 4502 unique reflections
OM970237C
(38) North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351.
(39) Sheldrick, G. M. SHELXTL-PLUS; Siemens Analitical X-ray
Instruments, Inc.: Madison WI, 1990.
(40) Sheldrick, G. M. SHELXL-93. Program for Crystal Structure
Refinement; Institu¨t fu¨r Anorganische Chemie der Universita¨t: Go¨t-
tingen, Germany, 1993.