Unexpected formation of osmium carbyne and vinylidene complexes from the reaction of OsCl2(PPh3)3 with HC triple bond CCMe3

Article abstract of DOI:10.1021/om000306e

The reaction of osmium vinylidene complexes with HC triple bond CCMe₃ was investigated. The formation of osmium carbyne and vinylidene complexes was observed. The complex was characterized by NMR spectroscopy and X-ray diffraction. The solid st

Full text of DOI:10.1021/om000306e

Organometallics 2000, 19, 3757-3761
3757
Articles
Un exp ected F or m a tion of Osm iu m Ca r byn e a n d
Vin ylid en e Com p lexes fr om th e Rea ction of OsCl2(P P h 3)3
w ith HCtCCMe3
Ting Bin Wen,† Sheng-Yong Yang,† Zhong Yuan Zhou,‡ Zhenyang Lin,†
Chak-Po Lau,‡ and Guochen J ia*,†
Department of Chemistry, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong, China, and Department of Applied Biology and
Chemical Technology, Hong Kong Polytechnic University, Hong Kong, China
Received April 11, 2000
Treatment of OsCl2(PPh3)3 with HCtCCMe3 produced a mixture of OsCl3(tCCH2CMe3)-
(PPh3)2 and OsCl(dCdCHCMe3)(C(CtCCMe3)dCHCMe3)(PPh3)2. The structures of the new
complexes have been confirmed by X-ray diffraction studies.
In tr od u ction
studied the reactions of OsCl2(PPh3)3 with HCtCR. To
our knowledge, reactions of OsCl2(PPh3)3 with HCtCR
have not been well studied, except for the reaction of
OsCl2(PPh3)3 with HCtCC(OH)Ph2 to give OsCl2(dCd
CdCPh2)(PPh3)2.12 In this report, we wish to describe
the reaction of OsCl2(PPh3)3 with HCtCCMe3.
Ruthenium vinylidene complexes of the type RuCl2-
(dCdCHR)(PR′3)2 have been reported as early as 1991.
The first example of these complexes was RuCl2(dCd
CHCMe3)(PPh3)2, which was prepared from the reaction
of HCtCCMe3 with RuCl2(PPh3)3.1 Since then, several
new RuCl2(dCdCHR)(PR′3)2 complexes have been pre-
pared from either the reactions of HCtCR with dichloro
ruthenium complexes such as RuCl2H2(PR′3)2 (R′ ) Cy,
i-Pr),2 [RuCl2(P(i-Pr)3)2]n,3 RuCl2(MeCN)2(P(i-Pr)3)2,3
Resu lts a n d Discu ssion
Treatment of OsCl2(PPh3)3 (1)13 with HCtCCMe3 in
benzene produced a yellow precipitate and a reddish
brown solution. The precipitate was identified to be the
carbyne complex OsCl3(tCCH2CMe3)(PPh3)2 (2), which
was isolated in 41% yield. From the brown solution, the
novel complex OsCl(dCdCHCMe3)(C(CtCCMe)dCH-
CMe3)(PPh3)2 (3) could be isolated in 39% yield (Scheme
1). The expected vinylidene complex OsCl2(dCdCHC-
Me3)(PPh3)2 could not be isolated from the reaction,
3
and [RuCl2(p-cumene)]2/PR′3 or the reaction of RuCl2-
(dCHPh)(PCy3)2 with 1,2-propadiene.4 These vinylidene
complexes are interesting because they are catalytically
active for olefin metathesis reactions.4,5 In contrast to
ruthenium, related osmium vinylidene complexes of the
type OsCl2(dCdCHR)(PR′3)2 have not been reported,
despite the fact that a large number of other osmium
vinylidene complexes have been prepared.6-11 With the
hope of obtaining OsCl2(dCdCHR)(PPh3)2, we have
(10) (a) Esteruelas, M. A.; Oliva´n, M.; On˜ate, E.; Ruiz, N.; Tajada,
M. A. Organometallics 1999, 18, 2953. (b) Crochet, P.; Esteruelas, M.
A.; Lo´pez, A. M.; Mart´ınez, M. P.; Oliva´n, M.; On˜ate, E.; Ruiz, N.
Organometallics 1998, 17, 4501. (c) Esteruelas, M. A.; Lo´pez, A. M.;
Ruiz, N.; Tolosa, J . I. Organometallics 1997, 17, 4657. (d) Crochet, P.;
Esteruelas, M. A.; Lo´pez, A. M.; Ruiz, N.; Tolosa, J . I. Organometallics
1998, 17, 3479. (e) Bourgault, M.; Castillo, A.; Esteruelas, M. A.; On˜ate,
E.; Ruiz, N. Organometallics 1998, 17, 636.
(11) For additional examples of osmium vinylidene complexes, see
for example: (a) Esteruelas, M. A, Go´mez, A. V.; Lo´pez, A. M.; Oro, L.
A. Organometallics 1996, 15, 878. (b) Gamasa, M. P.; Gimeno, J .;
Gonzalez-Cueva, M.; Lastra, E. J . Chem. Soc., Dalton Trans. 1996,
2547. (c) Esteruelas, M. A.; Oro, L. A.; Ruiz, N. Organometallics 1994,
13, 1507. (d) Hodge, A. J .; Ingham, S. L.; Kakkar, A. K.; Khan, M. S.;
Lewis, J .; Long, N. J .; Parker, D. G.; Raithby, P. R. J . Organomet.
Chem. 1995, 488, 205. (e) Werner, H.; Weinand, R.; Knaup, W.; Peters,
K.; von Schnering, H. G. Organometallics 1991, 10, 3967. (f) Knaup,
W.; Werner, H. J . Organomet. Chem. 1991, 411, 471. (g) Werner, H.;
Stahl, S.; Kohlman, W. J . Organomet. Chem. 1991, 409, 285. (h)
Werner, H.; Weber, B.; Nu¨berg, O.; Wolf, J . Angew. Chem., Int. Ed.
Engl. 1992, 31, 1025. (i) Bruce, M. I. Chem. Rev. 1991, 91, 197 and
references therein.
† The Hong Kong University of Science and Technology.
‡ Hong Kong Polytechnic University.
(1) (a) Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.; Satoh, T.;
Satoh, J . Y. J . Am. Chem. Soc. 1991, 113, 9604. (b) Wakatsuki, Y.;
Koga, N.; Yamazaki, H.; Morokuma, K. J . Am. Chem. Soc. 1994, 116,
8105.
(2) (a) Gru¨nwald, C.; Gevert, O.; Wolf, J .; Gonza´lez-Herrero, P.;
Werner, H. Organometallics 1996, 15, 1960. (b) Wolf, J .; Stu¨er, W.;
Gru¨nwald, C.; Gevert, O.; Laubender, M.; Werner, H. Eur. J . Inorg.
Chem. 1998, 1827.
(3) Katayama, H.; Ozawa, F. Organometallics 1998, 17, 5190.
(4) Schwab, P.; Grubbs, R. H.; Ziller, J . W. J . Am. Chem. Soc. 1996,
118, 100.
(5) Katayama, H.; Ozawa, F. Chem. Lett. 1998, 67.
(6) Werner, H.; J ung, S.; Weberno¨rfer, B.; Wolf, J . Eur. J . Inorg.
Chem. 1999, 951.
(7) (a) Oliva´n, M.; Clot, E.; Eisenstein, O.; Caulton, K. G. Organo-
metallics 1998, 17, 3091. (b) Oliva´n, M.; Clot, E.; Eisenstein, O.;
Caulton, K. G. Organometallics 1998, 17, 897. (c) Oliva´n, M.; Eisen-
stein, O.; Caulton, K. G. Organometallics 1997, 17, 2227.
(8) Huang, D.; Oliva´n, M.; Huffman, J . C.; Eisenstein, O.; Caulton,
K. G. Organometallics 1998, 17, 4700.
(12) Harlow, K. J .; Hill, A. F.; Wilton-Ely, J . D. E. J . Chem. Soc.,
Dalton Trans. 1999, 285.
(13) Hoffmann, P. R.; Caulton, K. G. J . Am. Chem. Soc. 1975, 97,
4221.
(9) (a) Buil, M. L.; Esteruelas, M. A. Organometallics 1999, 18, 1798.
(b) Esteruelas, M. A.; Oro, L. A.; Valero, C. Organometallics 1995, 14,
3596.
10.1021/om000306e CCC: $19.00 © 2000 American Chemical Society
Publication on Web 08/15/2000

3758 Organometallics, Vol. 19, No. 19, 2000
Wen et al.
Ta ble 1. Cr ysta l Da ta a n d Refin em en t Deta ils for
2‚1/2CH2Cl2 a n d 3
2‚1/2CH2Cl2
3
formula
C
42H41Cl3P2Os‚ C54H49ClP2Os
1/2CH2Cl2
fw
946.70
995.60
cryst syst
space group
a, Å
b, Å
c, Å
monoclinic
P21/c (Νï. 14)
12.9208(13)
20.381(2)
16.6709(16)
90
104.406(2)
90
4252.0(7)
4
triclinic
P1h (No. 2)
12.3785(13)
13.8032(14)
17.2639(17)
78.280(2)
70.488(2)
65.374(2)
2520.4(4)
2
R, deg
â, deg
γ, deg
V, Å3
Z
d
calcd, g cm-3
1.479
1.312
radiation (Mo KR), Å
0.710 73
1.91-27.54
27 942
0.710 73
1.25-27.56
16 949
θ range, deg
no. of rflns collected
no. of obsd rflns (I > 2σ(I)) 7146
8616
11 421
no. of indep rflns
9696
F igu r e 1. Molecular structure for OsCl3(tCCH2CMe3)-
(PPh3)2.
(Rint ) 4.79%)
496
(Rint ) 3.77%)
531
no. of params refined
final R indices (I > 2σ(I))
R1 ) 3.58%,
wR2 ) 8.48%
0.960
1.347
-0.749
R1 ) 4.66%,
wR2 ) 10.49%
0.959
2.528
-2.146
Sch em e 1
goodness of fit
largest diff peak, e Å-3
largest diff hole, e Å-3
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
(d eg) for 2‚1/2CH2Cl2 a n d 3
Compound 2‚1/2CH2Cl2
Os(1)-P(1)
Os(1)-Cl(1)
Os(1)-Cl(3)
C(1)-C(2)
2.4476(8)
2.4767(8)
2.3852(8)
1.448(4)
Os(1)-P(2)
Os(1)-Cl(2)
Os(1)-C(1)
C(2)-C(3)
2.4407(8)
2.4164(8)
1.728(3)
1.557(5)
C(1)-Os(1)-Cl(1) 177.79(9)
Cl(2)-Os(1)-Cl(3) 175.99(3)
P(2)-Os(1)-P(1)
C(1)-Os(1)-Cl(2)
Cl(1)-Os(1)-Cl(2)
C(1)-Os(1)-P(1)
Cl(2)-Os(1)-P(1)
Cl(3)-Os(1)-P(1)
P(1)-Os(1)-Cl(1)
C(1)-C(2)-C(3)
169.77(3)
90.99(9)
91.19(3)
C(2)-C(1)-Os(1)
C(1)-Os(1)-Cl(3)
Cl(1)-Os(1)-Cl(3)
176.8(2)
92.86(9)
84.96(3)
94.67(10)
89.70(3)
88.87(3)
84.94(3)
95.56(10) C(1)-Os(1)-P(2)
90.64(3)
90.10(3)
84.83(3)
117.0(3)
Cl(2)-Os(1)-P(2)
Cl(3)-Os(1)-P(2)
P(2)-Os(1)-Cl(1)
however. Formation of complexes 2 and 3 from the
reaction is somewhat unexpected, since the reaction of
HCtCCMe3 with RuCl2(PPh3)3 has been reported to
1
give RuCl2(dCdCHCMe3)(PPh3)2 and the reaction of
Compound 3
HCtCC(OH)Ph2 with OsCl2(PPh3)3 has been reported
Os(1)-P(1)
Os(1)-C(1)
Os(1)-Cl(1)
C(7)-C(8)
2.3848(8)
1.802(2)
2.3986(8)
1.343(4)
1.194(4)
Os(1)-P(2)
Os(1)-C(7)
C(1)-C(2)
C(7)-C(13)
2.3719(7)
2.047(2)
1.332(3)
1.420(3)
to give OsCl2(dCdCdCPh2)(PPh3)2.12
Complex 2 has been characterized by NMR spectros-
copy as well as an X-ray diffraction study. A view of the
molecular geometry of 2 is shown in Figure 1. The
crystallographic details and selected bond distances and
angles are given in Tables 1 and 2, respectively. The
geometry around osmium in 2 can be viewed as a
distorted octahedron with two PPh3 ligands at the apical
positions and the three chloride and tCCH2CMe3
ligands on the equatorial plane. The Os-C(carbyne)
bond distance is at 1.728(3) Å, which is fully consistent
with those reported previously.6,10a-c,14,15 Consistent
with the solid-state structure, the 1H NMR spectrum
displayed the tCCH2 proton signal at 0.88 ppm, the 13C
NMR spectrum exhibited the carbyne signal at 290.1
ppm, and the 31P{1H} NMR spectrum displayed only a
singlet at -12.3 ppm. Reported compounds closely
related to 2 include OsHCl2(tCR)(PR′3)2 (PR′3 ) P(i-
C(13)-C(14)
C(1)-Os(1)-C(7)
96.84(10) C(1)-Os(1)-Cl(1)
C(7)-Os(1)-Cl(1) 137.88(7) P(1)-Os(1)-P(2)
125.27(8)
176.08(2)
90.97(8)
90.48(8)
91.53(3)
130.6(3)
C(1)-Os(1)-P(2)
C(1)-Os(1)-P(1)
P(1)-Os(1)-Cl(1)
87.29(8) C(7)-Os(1)-P(2)
88.92(8) C(7)-Os(1)-P(1)
89.84(3) P(2)-Os(1)-Cl(1)
C(2)-C(1)-Os(1) 179.0(2)
C(1)-C(2)-C(3)
C(8)-C(7)-Os(1) 135.96(17) C(13)-C(7)-Os(1) 100.13(17)
C(8)-C(7)-C(13) 123.9(2)
C(7)-C(13)-C(14) 176.2(3)
C(7)-C(8)-C(9)
C(13)-C(14)-C(15) 172.3(3)
129.3(2)
Me)(P(i-Pr)2CH2CO2) (R ) Ph, Me),14 and OsCl2(SCN)-
(tCC6H4NMe2)(PPh3)2.17
The solid-state structure of complex 3 has also been
determined by an X-ray diffraction study. The crystal-
lographic details and selected bond distances and angles
are given in Tables 1 and 2, respectively. A view of the
molecular geometry of 3 is shown in Figure 2. It reveals
Pr)3,15,16 PCy3 ), OsCl2(tCCHdCRPh)(P(i-Pr)2CH2CO2-
6
(14) Weber, B.; Steinert, P.; Windmu¨ller, B.; Wolf, J .; Werner, H.
J . Chem. Soc., Chem. Commun. 1994, 2595.
(15) Espuelas, J .; Esteruelas, M. A.; Lahoz, F. J .; Oro, L. A.; Ruiz,
N. J . Am. Chem. Soc. 1993, 115, 4683.
(16) Spivak, G. J .; Coalter, J . N.; Oliva´n, M.; Eisenstein, O.; Caulton,
K. G. Organometallics 1998, 17, 999.
(17) Clark, G. R.; Edmonds, N. R.; Pauptit, R. A.; Roper, W. R.;
Waters, J . M.; Wright, A. H. J . Organomet. Chem. 1983, 244, C57.

Osmium Carbyne and Vinylidene Complexes
Organometallics, Vol. 19, No. 19, 2000 3759
at 5.6 and 7.8 ppm. The two broad signals merged to a
singlet at 6.3 ppm when the temperature was raised to
42 °C. Two sharp 31P{1H} signals in about a 2:1 ratio
at 5.8 and 8.6 ppm were observed when the temperature
1
was lowered to -38 °C. The H NMR spectrum showed
similar features. At room temperature, only one set of
1H signals was observed for the vinylidene and vinyl
groups. At low temperature, two sets of 1H signals were
observed for the vinylidene and vinyl groups. The two
sets of NMR data for complex 3 at low temperature
could be attributed to the two rotational isomers due to
the different orientations of the CMe3 group of the
vinylidene ligand. The two isomers of 3 observed in
solution at low temperature could also, in principle,
arise from the rotation about the Os-vinyl bond.
Quantum-mechanical calculations23 on the model com-
plex OsCl(dCdCH2)(C(CtCH)dCH2)(PH3)2 suggest that
the isomers of 3 observed in solution at low temperature
are derived from the rotation of the vinylidene ligand
about the Os-vinylidene bond rather than the rotation
of the vinyl group. The barrier of vinylidene rotation is
calculated to be ca. 12.0 kcal/mol at the B3LYP level of
theory, large enough to freeze the rotation at low
temperature. The rotational barrier of the vinyl group
is found to be much lower (ca. 6.0 kcal/mol), which is
too small to be responsible for the observation of the
two isomers. In the solid-state structure of 3, the CMe3
group of the vinylidene unit is on the same side of Cl.
The CMe3 group could also be on the same side of the
vinyl group, although this rotational isomer is expected
to be less stable, owing to the larger steric interaction
between the CMe3 group and the C(CtCCMe3)d
CHCMe3 unit. At high temperature, the two isomers
interconvert very rapidly due to the fast rotation of the
vinylidene ligand; thus, only one set of NMR signals was
observed. At low temperature, rotation of the vinylidene
ligand is frozen out; thus, two isomers could be detected
by NMR spectroscopy. Rotation about metal-vinylidene
bonds on the NMR time scale has been observed pre-
viously10e,24 for complexes such as OsHCl(dCdCHPh)-
(P(i-Pr)3)2,10e [(C7H7)Mo(dCdCHR)(dppe)]+,24a and [Cp-
Ru(dCdCHR)(Ph2PCH2CHMePPh2)]+.24b
F igu r e 2. Molecular structure for OsCl(dCdCHCMe3)-
(C(CtCMe3)dCHCMe3)(PPh3)2.
that three molecules of HCtCCMe3 have been incor-
porated into the osmium center, one in the form of the
vinylidene ligand dCdCHCMe3 and the other two in
the form of the vinyl ligand C(CtCCMe3)dCHCMe3.
The ligand C(CtCCMe3)dCHCMe3 is likely formed
from the intramolecular coupling of the CtCCMe3 and
dCdCHCMe3 units (see discussion below). The overall
geometry around osmium in complex 3 can be described
as a distorted trigonal bipyramid with the two PPh3
ligands at the apical positions. The equatorial positions
are occupied by Cl, dCdCHCMe3, and C(CtCCMe3)d
CHCMe3 ligands. A number of complexes with η3-C-
(CtCR)dCHR or η3-C(CtCR)dCHR′ ligands have been
reported in which the CtC triple bond is coordinated
to metals.18 In complex 3, the interaction between the
CtC triple bond and the Os center must be weak, if it
exists at all, as the Os-C(13) and Os-C(14) distances
are quite long (over 2.6 Å). Another interesting feature
of structure 3 is that the carbon atoms of the vinylidene
unit (C(1), C(2), C(3)) and the C(CtCCMe3)dCHCMe3
unit (C(7), C(8), C(9), C(13), C(14), C(15)) are essentially
coplanar with Os and Cl. Such a feature is very similar
to that observed for the related compound OsCl(dCd
CHSiMe3)(CHdCHSiMe3)(P(i-Pr)3)2.8
Scheme 2 shows a plausible mechanism for the
formation of 2 and 3. Reaction of 1 with HCtCCMe3
can lead to the formation of the hydrido-acetylide
intermediate A. Intermediate A can then undergo
reductive elimination of HCl to give the acetylide
complex C or isomerization to give the vinylidene
complex B. Related osmium vinylidene complexes OsHCl-
(dCdCHR)(PR3)2 have been reported previously.6,7 Pro-
tonation of the vinylidene complex B with HCl would
give the carbyne complex 2. It is also possible that the
carbyne complex 2 is formed by direct protonation of B
with A (without prior release of HCl from A). The
Complexes with both vinyl and vinylidene ligands are
interesting, as such complexes have been proposed as
intermediates in the coupling of terminal acetylenes
with vinyl ligands.8,19-21 Until now, very few complexes
with both vinyl and vinylidene ligands have been
isolated,22 and only OsCl(dCdCHSiMe3)(CHdCHSi-
Me3)(P(i-Pr)3)2 has previously been structurally char-
acterized.8
In solution, complex 3 is fluxional. At room temper-
ature, complex 3 exhibited two broad 31P{1H} signals
(18) See for example: (a) Yang, S. M.; Chan, M. C. W.; Cheung, K.
K.; Che, C. M.; Peng, S. M. Organometallics 1997, 16, 2819 and
references therein. (b) Bianchini, C.; Innocenti, P.; Peruzzini, M.;
Romerosa, A.; Zanobini, F. Organometallics 1996, 15, 272 and refer-
ences therein.
(19) Selnau, H. E.; Merola, J . S. J . Am. Chem. Soc. 1991, 113, 4008.
(20) Werner, H.; Scha¨fer, M.; Wolf, J .; Peters, K.; Von Schnering,
H. G. Angew. Chem., Int. Ed. Engl. 1995, 34, 191.
(21) Braun, T.; Meuer, P.; Werner, H. Organometallics 1996, 15,
4075.
(22) (a) Wiedemann, R.; Wolf, J .; Werner, H. Angew. Chem., Int. Ed.
Engl. 1995, 34, 1244. (b) Wiedemann, R.; Steinert, P.; Scha¨fer, M.;
Werner, H. J . Am. Chem. Soc. 1993, 115, 9864. (c) Werner, H.;
Wiedemann, R.; Steinert, P.; Wolf, J . Chem. Eur. J . 1997, 3, 127.
(23) Density functional calculations at the B3LYP level were
performed on the model complex OsCl(dCdCH2)(C(CtCH)dCH2)-
(PH3)2. The basis set used for C and H atoms was 6-31G**. For Os, Cl,
and P atoms, an effective core potential with the LanL2DZ basis set
was employed.
(24) (a) Beddoes, R. L.; Biton, C.; Grime, R. W.; Ricalton, A.;
Whiteley, M. W. J . Chem. Soc., Dalton Trans. 1995, 2973. (b) Consiglio,
G.; Morandini, F. Inorg. Chim. Acta 1987, 127, 79. (c) Gamasa, M. P.;
Gimeno, J .; Lastra, E.; Martin, B. M. P. Organometallics 1992, 11,
1373. (d) Senn, D. W.; Wong, A.; Patton, A. T.; Marsi, M.; Strouse, C.
E.; Gladysz, J . A. J . Am. Chem. Soc. 1988, 110, 6096. (e) Consiglio,
G.; Bangerter, F.; Darpin, C. Organometallics 1984, 3, 1446. (f) Boland-
Lussler, B. E.; Churchill, M. R.; Hughes, R. P.; Rheingold, A. L.
Organometallics 1982, 1, 628.

3760 Organometallics, Vol. 19, No. 19, 2000
Wen et al.
Sch em e 2
dried under vacuum overnight. Yield: 0.21 g, 41%. The yellow
acetylide complex C could react with another molecule
of HCtCCMe3 to give intermediate D, which could
undergo a coupling reaction to give E. Reaction of E with
HCtCCMe3 would produce complex 3. As implied in
Scheme 2, elimination of HCl from A is the key step for
the formation of 3, and the eliminated HCl is also
responsible for the formation of the carbyne complex 2.
Consistent with the proposed mechanism, it was shown
that reaction of 1 with HCtCCMe3 in the presence of
NEt3 leads to the formation of complex 3 only, while
reaction of 1 with HCtCCMe3 in the presence of added
HPPh3Cl only leads to the formation of complex 2.
In summary, the reaction of OsCl2(PPh3)3 with HCt
CCMe3 did not lead to isolation of the expected vi-
nylidene complex OsCl2(dCdCHCMe3)(PPh3)2 but,
rather, a mixture of the novel complexes OsCl(dCd
CHCMe3)(C(CtCCMe3)dCHCMe3)(PPh3)2 and OsCl3-
(tCCH2CMe3).
solid was identified to be 2. Selected characterization data for
1
2: 31P{1H} NMR (121.5 MHz, CD2Cl2): δ -12.3 (s). H NMR
(300.13 MHz, CD2Cl2): δ 0.49 (s, 9 H, C(CH3)3), 0.88 (s, 2 H,
OstCCH2), 7.43-7.34 (m, 18 H, PPh3), 7.94-7.87 (m, 12 H,
PPh3). 13C{1H} NMR (100.40 MHz, CD2Cl2): δ 290.1 (t, J (PC)
) 9.24 Hz, OstC), 136.3-128.3 (m, PPh3), 65.20 (s, OsCCH2),
33.54 (s, C(CH3)3), 30.63 (s, C(CH3)3). Anal. Calcd for C42H41
-
Cl3P2Os: C, 55.78; H, 4.57. Found: C, 55.69; H, 4.60. The
solvents of the filtrate obtained above were removed in vacuo
to dryness, and the brown residue was extracted with 2 mL of
CH2Cl2. After addition of 30 mL of hexane, the reddish brown
solution was allowed to stand at -8 °C for several days to give
3 as a brown microcrystalline solid, which was collected on a
filter frit, washed with hexane, and dried under vacuum
overnight. Yield: 0.22 g, 39%. Selected characterization data
for 3: 31P{1H} NMR (121.5 MHz, CD2Cl2, 298 K) δ 5.6 (br),
1
7.8 (br); H NMR (300.13 MHz, CD2Cl2, 298 K) δ 0.15 (br, 1
H, OsdCdCH), 0.36 (br, 9 H, C(CH3)3), 0.59 (br, 9 H, C(CH3)3),
1.04 (br, 9 H, C(CH3)3), 4.14 (br, 1 H, OsCdCHC(CH3)3), 7.64-
7.30 (m, 30 H, PPh3); 13C{1H} NMR (75.47 MHz, CD2Cl2, 298
K) δ 274.5 (br, OsdC), 149.5 (s, OsCdCHCMe3), 136.43-
128.29 (m, other aromatic C and -CtC-), 121.26 (br, Osd
CdCH), 36.20 (s, C(CH3)3), 33.01 (s, C(CH3)3), 30.7 (s, C(CH3)3),
30.5 (s, C(CH3)3), 29.48 (br, C(CH3)3), 26.94 (br, C(CH3)3). Anal.
Calcd for C54H59ClP2Os: C, 65.14; H, 5.97. Found: C, 65.12;
H, 6.01.
Cr ysta llogr a p h ic An a lysis for 2‚1/2CH2Cl2. Suitable crys-
tals of 2 for X-ray diffraction study were grown by layering
hexane over a CH2Cl2 solution of 2. CH2Cl2 is cocrystallized
with 2. A yellow plate crystal having approximate dimensions
of 0.20 × 0.18 × 0.09 mm3 was mounted on a glass fiber and
used for X-ray structure determination. Intensity data were
collected on a Bruker SMART CCD area detector. The inten-
sity data were corrected for SADABS (Siemens area detector
absorption) (from 0.718 to 1 on I). Of 27 942 reflections
collected, 9696 were unique and 7146 were observed with I >
2σ(I). The structure was solved by direct methods and refined
by full-matrix least squares on F2 using the Bruker SHELXTL
(version 5.10) program package. All non-hydrogen atoms were
refined anisotropically. The H atoms, except those for the
disordered CH2Cl2, were placed in ideal positions and refined
Exp er im en ta l Section
All manipulations were carried out under a nitrogen atmo-
sphere using standard Schlenk techniques. Solvents were
distilled under nitrogen from sodium-benzophenone (hexane,
ether, THF), sodium (benzene), or calcium hydride (CH2Cl2).
The starting material OsCl2(PPh3)3 was prepared according
to the literature method.13 All other reagents were used as
purchased from Aldrich Chemical Co.
Microanalyses were performed by M-H-W Laboratories
(Phoenix, AZ). 1H, 13C{1H}, and 31P{1H} NMR spectra were
collected on a Bruker ARX-300 spectrometer (300 MHz). 1H
and 13C NMR chemical shifts are relative to TMS, and 31P
NMR chemical shifts are relative to 85% H3PO4.
P r epar ation of OsCl3(tCCH2CMe3)(P P h 3)2 (2) an d OsCl-
(dCdCHCMe3)(C(CtCCMe3)dCHCMe3)(P P h 3)2 (3). A mix-
ture of OsCl2(PPh3)3 (0.60 g, 0.57 mmol) and HCtCCMe3 (0.42
mL, 3.42 mmol) in 15 mL of benzene was stirred at room
temperature for 3 days to give a yellow microcrystalline solid
and a reddish brown solution. The volume of the reaction
mixture was reduced to 5 mL. The yellow solid was then
collected by filtration, washed with benzene and hexane, and

Osmium Carbyne and Vinylidene Complexes
Organometallics, Vol. 19, No. 19, 2000 3761
via a riding model with assigned isotropic thermal parameters.
The asymmetric unit contains a half-molecule of CH2Cl2, in
which one of the Cl atoms is disordered over two sites (Cl(5),
Cl(6)), which were refined with occupancy factors of 0.25.
Application of fixed C-Cl distance restraints led to final
positions and refined via a riding model with assigned isotropic
2
thermal parameters. At convergence RF ) 0.0466, RwF
)
0.1049, and the maximum peak in the difference map is 2.528
e Å-3 in the vicinity of the Os atom, due to the strong
absorption of osmium.
2
convergence with RF ) 0.0358 and RwF ) 0.0848.
Cr ysta llogr a p h ic An a lysis for 3. Suitable crystals of 3
for X-ray diffraction study were grown by layering hexane over
a CH2Cl2 solution of 3. A pink plate crystal of 3 having
approximate dimensions of 0.23 × 0.20 × 0.05 mm3 was
Ack n ow led gm en t. We acknowledge financial sup-
port from the Hong Kong Research Grants Council.
mounted on
a glass fiber and used for X-ray structure
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic details, bond distances and angles, atomic coordi-
nates and equivalent isotropic displacement coefficients, and
anisotropic displacement coefficients for OsCl3(tCCH2CMe3)-
(PPh3)2‚1/2CH2Cl2 and OsCl(dCdCHCMe3)(C(CtCCMe3)dCH-
CMe3)(PPh3)2. This material is available free of charge via the
Internet at http://pubs.acs.org.
determination. Intensity data were collected on a Bruker
SMART CCD area detector. The intensity data were corrected
for SADABS (Siemens area detector absorption) (from 0.623
to 0.922 on I). Of 16 949 reflections collected, 11 421 were
unique and 8616 were observed with I > 2σ(I). The structure
was solved by direct methods. All non-hydrogen atoms were
refined anisotropically. The two vinyl protons (H2A and H8A)
were located from the difference Fourier map and refined
isotropically. The remaining H atoms were placed in ideal
OM000306E