New cyclopentadienylosmium derivatives prepared from the five-coordinate complex [OsHCl(CO)(PPri3)2]

Article abstract of DOI:10.1021/om950620m

The reaction of [OsHCl(CO)(PPrⁱ₃)₂] (1) with cyclopentadiene in refluxing methanol affords the novel cyclopentadienylosmium(II) complex [OsH(η⁵-C₅H₅)(CO)-(PPrⁱ ₃)] (2)

Full text of DOI:10.1021/om950620m

878
Organometallics 1996, 15, 878-881
Notes
New Cyclop en ta d ien ylosm iu m Der iva tives P r ep a r ed
fr om th e F ive-Coor d in a te Com p lex [OsHCl(CO)(P P r i ) ]
3 2
Miguel A. Esteruelas,* Angel V. Go´mez, Ana M. Lo´pez, and Luis A. Oro
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Received August 8, 1995X
Summary: The reaction of [OsHCl(CO)(PPri ) ] (1) with
Although half-sandwich cyclopentadienylruthenium
complexes exhibit a particularly rich and interesting
chemistry9 and have formed one of the cornerstones in
the development of organometallic chemistry, the chem-
istry of the corresponding Os(η5-C5R5) complexes has
attracted comparatively less attention. This is in part
due to the lack of convenient osmium synthetic precur-
sors.10 Traditional synthetic routes to half-sandwich
cyclopentadienyl or (pentamethylpentadienyl)osmium
complexes have, in general, relied extensively upon the
dicarbonyl compounds [Os(η5-C5R5)X(CO)2] (X ) H, Br,
I)9a,11,12 and the bis(phosphine) derivatives [Os(η5-C5R5)X-
(PR3)2] (X ) Cl, Br, I, H)9a,13 as starting materials. In
general, cyclopentadienylosmium complexes are less
accessible than the related (pentamethylcyclopentadi-
enyl)osmium derivatives.
3 2
cyclopentadiene in refluxing methanol affords the novel
cyclopentadienylosmium(II) complex [OsH(η5-C5H5)(CO)-
(PPri )] (2). Reaction of 2 with CCl4 in pentane gives
3
the chloro complex [Os(η5-C5H5)Cl(CO)(PPri )] (3). The
3
protonation of 2 with HBF4‚Et2O leads to the trans-
dihydridoosmium(IV) complex [OsH2(η5-C5H5)(CO)(PPri3)]-
BF (4). Treatment of the chloro complex 3 with AgBF4
followed by the terminal alkyne phenylacetylene or
1-ethynyl-1-cyclohexanol gives the stable vinylidene [Os-
(η5-C5H5){dCdC(H)Ph}(CO)(PPri )]BF4 (5) or vinylvi-
3
nylidene [Os(η5-C5H5){dCdC(H)CdCH(CH2)3CH2}(CO)-
(PPri )]BF4 (6), respectively.
3
In tr od u ction
We have previously reported that the treatment of
In this paper we report a new synthetic route to
obtain cyclopentadienylosmium complexes, including
hydrido, halide, vinylidene, and vinylvinylidene deriva-
tives.
OsCl3‚xH2O with triisopropylphosphine in refluxing
methanol leads to [OsHCl(CO)(PPri ) ] in nearly quan-
3 2
titative yield.1 This complex, which is an active and
highly selective catalyst for the reduction of unsaturated
organic substrates2 and for the addition of HSiEt3 to
phenylacetylene,3 has been also the master key for the
development of an extensive organometallic chemistry,
including mono-4 and binuclear tetrahydridoborate,5
vinyl,6 alkynyl,7 vinylacetate,7b and carbene7b,8 com-
pounds.
Resu lts a n d Discu ssion
Treatment of a boiling methanol suspension of [OsH-
Cl(CO)(PPri ) ] (1) with freshly distilled cyclopentadiene
3 2
in a 1:25 molar ratio for 2 days gives, after filtration
and solvent removal, a sticky residue. Pentane extrac-
tion of the residue and filtration to remove the salt
We have now observed that the reaction of the
complex [OsHCl(CO)(PPri3)2] with cyclopentadiene leads
to the cyclopentadienyl derivative [OsH(η5-C5H5)(CO)-
[HPPri ]Cl affords a yellow solution that contains the
3
hydrido cyclopentadienyl complex [OsH(η5-C5H5)(CO)-
(PPri )], which can be the starting point for new half-
3
(PPri )] (2; Scheme 1). Complex 2 was isolated as a
3
sandwich osmium complexes.
white crystalline solid in 52% yield after solvent removal
and recrystallization from methanol. If the diolefin is
added in one portion, it dimerizes before completion of
the reaction. Two successive additions of cyclopenta-
diene improve the yield: half at the beginning and half
after reflux for 1 day.
The hydrido ligands in complex 2 is readily replaced
by a chloro ligand by treatment with CCl4. Thus,
addition of CCl4 to a pentane solution of 2 in a 1:20
X Abstract published in Advance ACS Abstracts, December 15, 1995.
(1) Esteruelas, M. A.; Werner, H. J . Organomet. Chem. 1986, 303,
221.
(2) (a) Esteruelas, M. A.; Sola, E.; Oro, L. A.; Werner, H.; Meyer, U.
J . Mol. Catal. 1988, 45, 1. (b) Werner, H.; Meyer, U.; Esteruelas, M.
A.; Sola, E.; Oro, L. A. J . Organomet. Chem. 1989, 366, 187. (c)
Esteruelas, M. A.; Sola, E.; Oro, L. A.; Werner, H.; Meyer, U. J . Mol.
Catal. 1989, 53, 43. (d) Andriollo, A.; Esteruelas, M. A.; Meyer, U.;
Oro, L. A.; Sa´nchez-Delgado, R. A.; Sola, E.; Valero, C.; Werner, H. J .
Am. Chem. Soc. 1989, 111, 7431. (e) Esteruelas, M. A.; Oro, L. A.;
Valero, C. Organometallics 1992, 11, 3362.
(3) Esteruelas, M. A.; Oro, L. A.; Valero, C. Organometallics 1991,
10, 462.
(4) Werner, H.; Esteruelas, M. A.; Meyer, U.; Wrackmeyer, B. Chem.
Ber. 1987, 120, 11.
(9) (a) Albers, M. O.; Robinson, D. J .; Singleton, E. Coord. Chem.
Rev. 1987, 79, 1. (b) Davies, S. G.; McNally, J . P.; Smallridge, A. J .
Adv. Organomet. Chem. 1990, 30, 1.
(5) Esteruelas, M. A.; Garc´ıa, M. P.; Lo´pez, A. M.; Oro, L. A.; Ruiz,
N.; Schlu¨nken, C.; Valero, C.; Werner, H. Inorg. Chem. 1992, 31, 5580.
(6) Werner, H.; Esteruelas, M. A.; Otto, H. Organometallics 1986,
5, 2295.
(7) (a) Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Valero,
C. Organometallics 1993, 12, 663. (b) Esteruelas, M. A.; Lahoz, F. J .;
Lo´pez, A. M.; On˜ate, E.; Oro, L. A. Organometallics 1994, 13, 1669.
(8) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Zeier, B.
Organometallics 1994, 13, 1662.
(10) (a) Dev, S.; Selegue, J . P. J . Organomet. Chem. 1994, 469, 107.
(b) Gross, C. L.; Wilson, S. R.; Girolami, G. S. J . Am. Chem. Soc. 1994,
116, 10294 and references therein.
(11) Herrmann, W. A.; Herdtweck, E.; Scha¨fer, A. Chem. Ber. 1988,
121, 1907.
(12) Pourreau, D. B.; Geoffroy, G. L.; Rheingold, A. L.; Geib, S. J .
Organometallics 1986, 5, 1337.
(13) Rottink, M. K.; Angelici, R. J . J . Am. Chem. Soc. 1993, 115,
7267.
0276-7333/96/2315-0878$12.00/0 © 1996 American Chemical Society

Notes
Organometallics, Vol. 15, No. 2, 1996 879
Sch em e 1
molar ratio leads to the chloro complex [Os(η5-C5H5)-
characteristic of the carbonyl ligand at 2030 cm-1. The
trans disposition of the hydrido ligands is proposed on
the basis of the 1H NMR spectrum in chloroform-d,
which shows, in the high-field region, a single doublet
at -11.41 ppm with a J (HP) coupling constant of 28.8
Hz. An alternative cisoid dihydrido structure should
Cl(CO)(PPri )] (3), which is isolated after 3 h as a
3
crystalline yellow solid in 72% yield. However, the most
direct route to the chloro complex 3, which avoids the
isolation of the hydride intermediate 2, is the treatment
of the above-mentioned pentane solution, resulting from
2
the filtration of [HPPri ]Cl, with CCl4. This direct route
give rise to two distinct hydride resonances. Further-
3
2
allows the isolation of 3 in higher yield, 66% as opposed
to the 36% overall yield of 3 based on the amount of 1
employed to make 2, probably due to the high solubility
of the hydrido complex 2 in most solvents.
more, a similar J (HP) coupling constant (29.0 Hz) has
been observed for the dihydride cation [OsH2(η5-C5H5)-
(PPh3)2]+, whose trans four-legged piano-stool geometry
has been determined by X-ray diffraction.13 The large
2J (HP) coupling constant together with a T1(min) value
of 457 ms (300 MHz, dichloromethane-d2, 193 K) sup-
port the formulation of 4 as a classical dihydride
compound.
We note that Geoffroy et al. have reported the iodo
pentamethylcyclopentadienyl complexes [Os(η5-C5Me5)I-
(CO)(PR3)] (PR3 ) PMe3, PPh3). These compounds were
readily prepared by photochemical reaction of the
precursor [Os(η5-C5Me5)I(CO)2] with PMe3 or PPh3
under CO pressure followed by treatment with Me3NO.
However, the related hydrido complex [OsH(η5-C5Me5)-
(CO)(PMe3)] could not be isolated as a pure compound
and was characterized by converting it to the bromo
derivative [Os(η5-C5Me5)Br(CO)(PMe3)].12
The behavior of 2 toward protonation differs markedly
from that observed for the related ruthenium complexes
[RuH(η5-C5H5)(CO)(PR3)] (PR3 ) PPh3, PMe3, PMe2Ph,
PCy3), which upon protonation with HBF4 give the
corresponding dihydrogen complexes [Ru(η5-C5H5)(η2-
H2)(CO)(PR3)]BF414 and is similar to that shown by the
osmium derivatives [OsH(η5-C5H5)(PR3)2] (PR3 ) PPh3,
PMePh2), which on treatment with CF3SO3H afford the
dihydrido species [OsH2(η5-C5H5)(CO)(PR3)]CF3SO3.13
Complexes 2 and 3 have been characterized by
elemental analysis and by IR and 1H and 31P NMR
spectroscopy. The IR spectrum of 2 in Nujol shows
absorptions due to ν(OsH) at 2080 cm-1 and ν(CO) at
Vinylidene compounds are among the most important
cyclopentadienyl derivatives of ruthenium.9,15 However,
very few vinylidene analogues of osmium have been
reported.12,16 Treatment of the chloro complex 3 with
AgBF4 in the presence of phenylacetylene in dichlo-
romethane gives the vinylidene [Os(η5-C5H5){dCdC(H)-
1900 cm-1
. The presence of the hydrido ligand is
1
confirmed by the H NMR spectrum, which contains a
doublet at -15.32 ppm (J (HP) ) 27.2 Hz) together with
the expected singlet at 4.71 ppm for the cyclopentadienyl
ligand and the characteristic signals for the PPri3 ligand.
The monohydrido complex 2 reacts with HBF4. The
addition of 1 equiv of HBF4‚Et2O to a solution of 2 in
dichloromethane-d2 at room temperature, gives quan-
titative formation of the dihydrido complex [OsH2(η5-
Ph}(CO)(PPri )]BF4 (5; Scheme 1). Complex 5 is ob-
3
tained as an orange solid in 82% yield after 3 h. The
(14) (a) Chinn, M. S.; Heinekey, D. M. J . Am. Chem. Soc. 1987, 109,
5865. (b) Chinn, M. S.; Heinekey, D. M. J . Am. Chem. Soc. 1990, 112,
5166.
C5H5)(CO)(PPri )]BF4 (4; Scheme 1), as evidenced by 1H
3
NMR spectroscopy. When the reaction of 2 with HBF4
is carried out in diethyl ether at room temperature,
complex 4 is isolated as a white solid in 70% yield. The
IR spectrum in Nujol shows the absorption due to the
[BF4]- anion with Td symmetry along with a weak ν-
(OsH) absorption at 2140 cm-1 and a strong band
(15) Bruce, M. I. Chem. Rev. 1991, 91, 197.
(16) (a) Bruce, M. I.; Humphrey, M. G. Aust. J . Chem. 1989, 42,
1067. (b) Bruce, M. I.; Humphrey, M. G.; Koutsantonis, G. A.; Liddell,
M. J . J . Organomet. Chem. 1987, 326, 247. (c) Bruce, M. I.; Humphrey,
M. G.; Liddell, M. J . J . Organomet. Chem. 1987, 321, 91. (d) Bruce,
M. I.; Koutsantonis, G. A.; Liddell, M. J .; Nicholson, B. K. J . Orga-
nomet. Chem. 1987, 320, 217.

880 Organometallics, Vol. 15, No. 2, 1996
Notes
IR spectrum in Nujol of 5 shows the absorptions due to
the [BF4]- anion at 1080 cm-1 along with bands
characteristic of the vinylidene and carbonyl ligands at
1670 (ν(CdC)) and 1990 (ν(CO)) cm-1, respectively. The
13C{1H} NMR spectrum contains the typical low-field
signal for the CR atom of the vinylidene ligand, which
appears as a doublet at 324.78 ppm with a 2J (CP)
coupling constant of 7.9 Hz. The 1H NMR spectrum
shows a singlet at 4.39 ppm corresponding to the proton
on the Câ atom.
Although the formation of vinylidene complexes from
reactions of 1-alkynes with certain unsaturated or labile
transition-metal complexes is now a well-established
method,15 only Geoffroy et al. have previously reported
a similar route for the synthesis of vinylideneosmium
compounds. Treatment of [Os(η5-C5Me5)I(CO)(PPh3)]
with AgBF4 followed by terminal alkynes gave the
vinylidene complexes [Os(η5-C5Me5){dCdC(H)R}(CO)-
(PPh3)]BF4 (R ) But, Ph).12 The phenylvinylidene
cation rapidly afforded the phenylacetylide complex by
deprotonation when filtered through Celite in air;
however, the structure of the tert-butyl derivative was
confirmed by an X-ray diffraction study.
(PMe3)2]+ dehydrate to give vinylvinylidenes,17 while
Dixneuf and co-workers have proposed that dehydration
of the isoelectronic arene systems [RuCl(η6-C6H6)-
{dCdCHC(OH)RR′}(PMe3)]+ gives allenylidene inter-
mediates that add methanol to afford methoxyvinylcar-
benes.18 Kolobova and co-workers have observed that
the action of SiO2 or Al2O3 on manganese hydroxyvi-
nylidene compounds causes their dehydration to allen-
ylidenes.19 Very recently, Werner et al. have shown that
the abstraction of water from the rhodium hydroxyvi-
nylidenes [RhCl{dCdCHC(OH)RR′}(PPri ) ] leads pref-
3 2
erentially to rhodium vinylvinylidenes.20
In conclusion, the versatile catalyst [OsHCl(CO)-
(PPri ) ] is a useful starting material not only for the
3 2
synthesis of mono- and binuclear tetrahydridoborate,
vinyl, alkynyl, vinylacetate, and carbene compounds but
also for the preparation of cyclopentadienylosmium
complexes, including hydrido, halide, vinylidene, and
vinylvinylidene compounds.
Exp er im en ta l Section
All reactions were carried out with rigorous exclusion of air
by using Schlenk tube techniques. Solvents were dried by the
usual procedures and distilled under argon prior to use. The
A similar reaction between the chloro derivative 3 and
1-ethynyl-1-cyclohexanol in dichloromethane, in the
presence of AgBF4, produced the vinylvinylidene com-
starting material [OsHCl(CO)(PPri )2] was prepared by pub-
3
lished methods.1
NMR spectra were recorded on either a Varian UNITY 300
or a Bruker 300 AXR spectrophotometer. Chemical shifts are
expressed in ppm upfield from Me4Si (1H and 13C) and 85%
H3PO4 (31P). Coupling constants, J , are given in Hz. The T1
experiments were performed on a Varian UNITY 300 spec-
trophotometer with a standard 180°-τ-90° pulse sequence.
T1 values are given in milliseconds (ms). IR spectra were run
on a Perkin-Elmer 783 spectrophotometer (Nujol mulls on
polyethylene sheets). C and H analyses were carried out on a
Perkin-Elmer 240C microanalyzer.
plex [Os(η5-C5H5){dCdC(H)CdCH(CH2)3CH2}(CO)-
(PPri )]BF4 (6; Scheme 1). Complex 6 was isolated as a
3
salmon solid in 78% yield. 6 is formulated as a vinylvi-
nylidene compound on the basis of its spectroscopic data.
In particular, the ν(CdC) infrared absorptions at 1656
and 1627 cm-1 and the absence of a ν(CdCdC) band at
ca. 1925 cm1-1 15 indicate that 6 is a vinylvinylidene,
rather than an allenylidene, complex. The 1H NMR
spectrum of 6 in chloroform-d shows the vinylidene and
vinylic protons as a singlet at 4.07 ppm and a broad
signal at 5.35 ppm, respectively. The most distinctive
features of the 13C{1H} NMR spectrum are a doublet
P r ep a r a tion of [OsH(η5-C5H5)(CO)(P P r i3)] (2). To a
solution of 1 (1.0 g, 1.74 mmol) in 20 mL of methanol was
added an excess of freshly distilled cyclopentadiene (1.5 mL,
22.24 mmol). The mixture was stirred at reflux temperature
for 24 h, and then another fraction of 1.5 mL of freshly distilled
cyclopentadiene was added and the mixture was refluxed for
a further 24 h. The color of the solution changed from red to
yellow, and then the solution was filtered and evaporated to
dryness. The residue was treated with 20 mL of hexane, and
2
at low field (δ 327.68, J (CP) ) 7.8 Hz) for the CR atom
of the vinylidene ligand and three singlets at 125.18,
123.21, and 118.80 ppm for the Câ and the vinylic carbon
atoms.
From a mechanistic point of view, the vinylvinylidene
6 most probably is the result of the spontaneous
dehydration of the hydroxyvinylidene intermediate 7 (eq
1).
the mixture was filtered to eliminate the [HPPri ]Cl. The
3
yellow solution was concentrated to about 3 mL and cooled to
-78 °C. A cream-colored solid precipitated, which was sepa-
rated by decantation, washed with cold hexane, and dried in
vacuo. The solid was recrystallized from methanol to give
white crystals which were separated by decantation, washed
with cold methanol, and dried in vacuo. Yield: 402 mg (52%).
Anal. Calcd for C15H27OPOs: C, 40.53; H, 6.12. Found: C,
40.70; H, 5.98. IR (Nujol, cm-1): ν(OsH) 2080 m; ν(CO) 1900
vs, br. 1H NMR (300 MHz, C6D6): δ 4.71 (s, 5H, Cp), 1.72 (m,
3H, PCHCH3), 0.94 (dd, 9H, J (HH) ) 7.1, J (PH) ) 13.7,
PCHCH3), 0.89 (dd, 9H, J (HH) ) 7.1, J (PH) ) 14.0, PCHCH3),
(17) Selegue, J . P.; Young, B. A.; Logan, S. L. Organometallics 1991,
10, 1972.
(18) (a) Le Bozec, H.; Ouzzine, K.; Dixneuf, P. H. J . Chem. Soc.,
Chem. Commun. 1989, 219. (b) Le Bozec, H.; Ouzzine; K.; Dixneuf,
P. H. Adv. Organomet. Chem. 1989, 29, 163. (c) Pilette, D.; Ouzzine,
K.; Le Bozec, H.; Dixneuf, P. H.; Rickard, C. E. F.; Roper, W. R.
Organometallics 1992, 11, 809.
(19) Kolobova, N. E.; Ivanov, L. L.; Zhvanko, O. S.; Derunov, V. V.;
Chechulina, I. N. Bull. Acad. Sci. USSR, Div. Chem. Sci. (Engl. Transl.)
1982, 31, 2328; Chem. Abstr. 1983, 98, 126312v.
(20) (a) Rappert, T.; Nu¨rnberg, O.; Mahr, N.; Wolf, J .; Werner, H.
Organometallics 1992, 11, 4156. (b) Werner, H.; Rappert, T. Chem.
Ber. 1993, 126, 669. (c) Werner, H.; Rappert, T.; Wiedemann, R.; Wolf,
J .; Mahr, N. Organometallics 1994, 13, 2721.
The dehydration of hydroxyvinylidene intermediates,
containing hydrogen atoms adjacent to the hydroxy
group, can occur in two different directions to give either
vinylvinylidene or allenylidene derivatives, depending
on the electronic and steric properties of the metal.
Selegue et al. have reported that the electron-rich
hydroxyvinylidenes [Ru(η5-C5H5){dCdCHC(OH)RR′}-

Notes
Organometallics, Vol. 15, No. 2, 1996 881
-15.32 (d, 1H, J (PH) ) 27.2, OsH). 31P{1H} NMR (121.4 MHz,
C6D6): δ 46.54 (s).
and phenylacetylene (21.5 µL, 0.19 mmol). The mixture was
stirred at room temperature for 3 h and filtered to eliminate
the AgCl. The solvent was removed in vacuo, and the residue
was washed with diethyl ether to give an orange solid, which
was separated by decantation and dried in vacuo. Yield: 92
mg (82%). Anal. Calcd for C23H32BF4OPOs: C, 43.68; H, 5.10.
Found: C, 43.70; H, 4.74. IR (Nujol, cm-1): ν(CO) 1990 vs;
ν(CdC) 1670 s; ν(Ph) 1595 w; ν(BF4) 1080 br. 1H NMR (300
MHz, CDCl3): δ 7.15 (m, 5H, Ph), 6.11 (s, 5H, Cp), 4.39 (s,
1H, dCH), 2.50 (m, 3H, PCHCH3), 1.28 (dd, 9H, J (HH) ) 7.8,
J (PH) ) 15.8, PCHCH3), 1.25 (dd, 9H, J (HH) ) 7.8, J (PH) )
15.8, PCHCH3). 31P{1H} NMR (121.4 MHz, CDCl3): δ 40.10
(s). 13C{1H} NMR (75.4 MHz, CDCl3): δ 324.78 (d, J (CP) )
7.9 Hz, OsdC), 176.86 (d, J (CP) ) 10.9 Hz, CO), 129.23,
127.94, 126.16, 122.56, 120.42 (all s, Ph and dCH), 91.21 (s,
Cp), 29.32 (d, J (CP) ) 30.9 Hz, PCHCH3), 19.84 (d, J (CP) )
1.9 Hz, PCHCH3), 19.61 (d, J (CP) ) 1.9 Hz, PCHCH3).
P r ep a r a tion of [OsCl(η5-C5H5)(CO)(P P r i3)] (3). Rou te
a . To a solution of 2 (235 mg, 0.53 mmol) in 10 mL of hexane
was added an excess of CCl4 (1 mL, 10.34 mmol). The mixture
was stirred for 3 h at room temperature, and a yellow solid
precipitated. The solid was separated by decantation, washed
with hexane, dried in vacuo, and recrystallized from methanol
to give yellow crystals. The crystals were separated by
decantation, washed with cold methanol, and dried in vacuo.
Yield: 182 mg (72%).
Rou te b. To a solution of 1 (1.0 g, 1.74 mmol) in 20 mL of
methanol was added an excess of freshly distilled cyclopenta-
diene (1.5 mL, 22.24 mmol). The mixture was stirred at reflux
temperature for 24 h, and then another fraction of 1.5 mL of
freshly distilled cyclopentadiene was added and the mixture
was refluxed for a further 24 h. The solution was filtered and
evaporated to dryness. The residue was treated with 20 mL
of hexane, and the mixture was filtered to eliminate the
P r ep a r a t ion
of
[Os(η5-C5H 5){dCdC(H )CdCH -
[HPPri ]Cl. The yellow solution was concentrated to about 10
3
(CH2)3_CH 2}(CO)(P P r i3)]BF 4 (6). A solution of 2 (85 mg,
0.18 mmol) in 10 mL of dichloromethane was treated with
AgBF4 (34.5 mg, 0.18 mmol) and an excess of 1-ethynyl-1-
cyclohexanol (44.97 mg, 0.36 mmol). The mixture was stirred
at room temperature for 3 h and filtered to eliminate the AgCl.
The solvent was removed in vacuo, and the residue was
washed with diethyl ether to give a salmon solid, which was
separated by decantation and dried in vacuo. Yield: 88 mg
(78%). Anal. Calcd for C23H36BF4OPOs: C, 43.40; H, 5.70.
Found: C, 43.07; H, 5.03. IR (Nujol, cm-1): ν(CO) 1981 vs;
ν(CdC) 1656 s, 1627 m; ν(BF4) 1050 br. 1H NMR (300 MHz,
mL, and an excess of CCl4 (1.5 mL, 15.51 mmol) was added.
The resulting solution was worked up as in route a. Yield:
552 mg (66%). Anal. Calcd for C15H26ClOPOs: C, 37.61; H,
5.26. Found: C, 37.79; H, 5.05. IR (Nujol, cm-1): ν(CO) 1906
vs, br. 1H NMR (300 MHz, C6D6): δ 5.21 (s, 5H, Cp), 2.53 (m,
3H, PCHCH3), 1.25 (dd, 9H, J (HH) ) 7.1, J (PH) ) 14.5,
PCHCH3), 1.19 (dd, 9H, J (HH) ) 7.1, J (PH) ) 13.4, PCHCH3).
31P{1H} NMR (121.4 MHz, C6D6): δ 24.16 (s).
P r ep a r a t ion of [OsH2(η5-C5H 5)(CO)(P P r i3)]BF 4 (4).
Rou te a . A solution of 2 (85 mg, 0.18 mmol) in 5 mL of diethyl
ether at room temperature was treated with HBF4 (25 µL, 0.18
mmol, 54% in diethyl ether). Immediately a white solid
precipitated. The solid was separated by decantation, washed
with diethyl ether, and dried in vacuo. Yield: 67 mg (70%).
Anal. Calcd for C15H28BF4OPOs: C, 33.84; H, 5.30. Found:
C, 33.61; H, 5.35. IR (Nujol, cm-1): ν(OsH) 2140 w; ν(CO) 2030
vs; ν(BF4) 1050 br. 1H NMR (300 MHz, CDCl3): δ 5.94 (s, 5H,
Cp), 2.32 (m, 3H, PCHCH3), 1.27 (dd, 18H, J (HH) ) 7.1, J (PH)
) 15.9, PCHCH3), -11.41 (d, 2H, J (PH) ) 28.8, OsH2). 31P-
{1H} NMR (121.4 MHz, CDCl3): δ 43.91 (s).
CDCl3): δ 6.11 (s, 5H, Cp), 5.35 (br s, 1H, CH2(CH2)3CdCH),
4.07 (s, 1H, dCdCH), 2.51 (m, 3H, PCHCH3), 2.41 (m, 2H,
Cy), 2.00-1.56 (br, 6H, Cy), 1.31 (dd, 9H, J (HH) ) 7.1, J (PH)
) 16.2, PCHCH3), 1.28 (dd, 9H, J (HH) ) 7.1, J (PH) ) 15.9,
PCHCH3). 31P{1H} NMR (121.4 MHz, CDCl3): δ 38.45 (s). 13C-
{1H} NMR (75.4 MHz, CDCl3): δ 327.68 (d, J (CP) ) 7.8 Hz,
OsdC), 177.41 (d, J (CP) ) 10.6 Hz, CO), 125.18, 123.21 (both
s, CH2(CH2)3CdCH and dCdCH, confirmed by DEPT), 118.80
Rou te b. A solution of 2 (4.9 mg, 0.011 mmol) in 0.5 mL of
CD2Cl2 in an NMR tube was treated with a stoichiometric
amount of HBF4 (1.5 µL, 0.011 mmol, 54% in diethyl ether).
The NMR tube was sealed under argon, and measurements
were made immediately. 1H NMR (300 MHz, CD2Cl2): δ 5.84
(s, 5H, Cp), 2.26 (m, 3H, PCHCH3), 1.23 (dd, 18H, J (HH) )
7.1, J (PH) ) 16.1, PCHCH3), -11.45 (d, 2H, J (PH) ) 29.1,
OsH2). T1 (OsH2, 300 MHz, CD2Cl2): 845 ms (213 K), 457 ms
(193 K).
(s, CH2(CH2)3CdCH), 91.12 (s, Cp), 29.25 (d, J (CP) ) 31.1 Hz,
PCHCH3), 28.09, 25.54, 22.48, 21.83 (all s, Cy), 19.83 (d, J (CP)
) 1.7 Hz, PCHCH3), 19.55 (d, J (CP) ) 2.0 Hz, PCHCH3).
Ack n ow led gm en t. We thank the DGICYT (Project
PB-92-0092, Programa de Promocio´n General del Cono-
cimiento) and the EU (European Union) (Project: Selec-
tive Processes and Catalysis Involving Small Molecules)
for financial support.
P r ep a r a tion of [Os(η5-C5H5){dCdC(H)P h }(CO)(P P r i3)]-
BF 4 (5). A solution of 2 (85 mg, 0.18 mmol) in 10 mL of
dichloromethane was treated with AgBF4 (34.5 mg, 0.18 mmol)
OM950620M