Carbon-carbon double bond formation from two o-methyl groups in osmium phosphine complexes

Article abstract of DOI:10.1021/om000593m

The osmium complex [(NH₄)₂OsCl₆] reacts with PPh₂(2,6-Me₂C₆H₃) in a 2-propanol-water mixture at reflux to give quantitatively a cyclometalated osmium(II) complex containing a tridentate trans-stilbene-type ligand, which forms via a dehydrogenative carbon-carbon coupling of two phosphine o-methyl groups. The structure of this complex has been determined by an X-ray investigation. Carbon-carbon double bond formation has also been observed in the reaction of the osmium(II) precursor [OsCl₂(PPh₃)₃] with PPh₂(2,6-Me₂C₆H₃) in toluene, leading to a hydrido osmium(II) complex containing the same tridentate stilbene-type ligand.

Full text of DOI:10.1021/om000593m

Organometallics 2001, 20, 305-308
305
Ca r bon -Ca r bon Dou ble Bon d F or m a tion fr om Tw o
o-Meth yl Gr ou p s in Osm iu m P h osp h in e Com p lexes
Walter Baratta,*,† Eberhardt Herdtweck,‡ Paolo Martinuzzi,† and Pierluigi Rigo†
Dipartimento di Scienze e Tecnologie Chimiche, Universita` di Udine, Via Cotonificio 108,
I-33100 Udine, Italy, and Anorganisch-chemisches Institut, Technische Universita¨t Mu¨nchen,
Lichtenbergstrasse 4, D-85747 Garching, Germany
Received J uly 11, 2000
The osmium complex [(NH4)2OsCl6] reacts with PPh2(2,6-Me2C6H3) in a 2-propanol-water
mixture at reflux to give quantitatively a cyclometalated osmium(II) complex containing a
tridentate trans-stilbene-type ligand, which forms via a dehydrogenative carbon-carbon coup-
ling of two phosphine o-methyl groups. The structure of this complex has been determined
by an X-ray investigation. Carbon-carbon double bond formation has also been observed in
the reaction of the osmium(II) precursor [OsCl2(PPh3)3] with PPh2(2,6-Me2C6H3) in toluene,
leading to a hydrido osmium(II) complex containing the same tridentate stilbene-type ligand.
In tr od u ction
In continuation of our work on the chemistry of
complexes having aryl phosphines with two methyl
groups in ortho positions,1 we report herein the results
obtained with osmium. It can be anticipated that with
osmium, which is more electron rich compared to
ruthenium, cyclometalation is expected. Furthermore,
it is well-known that haloosmium(II) derivatives bearing
small phosphines are generally six-coordinate species
of general formula [OsX2(PR3)4] (X ) halide),7 whereas
with the bulky triphenylphosphine five-coordinate com-
plexes such as [OsX2(PPh3)3] are formed,8 similarly to
the ruthenium analogues.9 We have now found that
employment of PPh2(2,6-Me2C6H3) leads to formation
in high yield of osmium complexes bearing the triden-
tate chelating ligand BDP S (Figure 1).
The latter contains an olefinic bond that is formed
from two o-methyl groups of two phosphines, as result
of activation of four C-H bonds. Coupling between
o-methyl groups of aryl phosphines was previously
observed by Bennett and Longstaff in the reaction of
rhodium(III) halides with PPhn(2-MeC6H4)3-n, the prod-
ucts being isolated in only poor yields.10
It has recently pointed out that the phosphine PPh2-
(2,6-Me2C6H3) (L) is a suitable ligand for the isolation
of a rare example of the 14-electron ruthenium com-
pound [RuCl2L2], stabilized by two agostic interactions
of two o-methyl groups.1 Bulky phosphines have been
extensively employed to obtain coordinatively unsatur-
ated complexes, which can be stabilized by agostic
interactions,2 or cyclometalated species that result from
intramolecular C-H activation (i.e., oxidative addition),3
depending on the features of the metal center. The
cleavage of a C-H bond by direct participation of a
transition metal4 is a process of considerable interest
for potential applications in catalytic hydrocarbon trans-
formations.5 On the other hand, compounds containing
agostic interactions have been proposed as intermedi-
ates in reactions involving C-H bond splitting.6
* To whom correspondence should be addressed. E-mail: inorg@
dstc.uniud.it.
† Universita` di Udine.
‡ Universita¨t Mu¨nchen.
(1) Baratta, W.; Herdtweck, E.; Rigo, P. Angew. Chem., Int. Ed.
1999, 38, 1629.
(2) (a) Brookhart, M.; Green, M. L. H.; Wong, L.-L. Prog. Inorg.
Chem. 1988, 36, 1. (b) Crabtree, R. H.; Hamilton, D. G. Adv. Orga-
nomet. Chem. 1988, 28, 299. (c) Crabtree, R. H. Angew. Chem., Int.
Ed. Engl. 1993, 32, 789. (d) Yao, W.; Eisenstein, O.; Crabtree, R. H.
Inorg. Chim. Acta 1997, 254, 105. (e) Cooper, A. C.; Clot, E. Huffman,
J . C.; Streib, W. E.; Maseras, F.; Eisenstein, O.; Caulton, K. G. J . Am.
Chem. Soc. 1999, 121, 97.
Resu lts a n d Discu ssion
Treatment of ammonium hexachloroosmate(IV) with
PPh2(2,6-Me2C6H3) in a 2-propanol-water mixture un-
(3) Ryabov, A. D. Chem. Rev. 1990, 90, 403.
(6) Crabtree, R. H.; Hamilton, D. G. Adv. Organomet. Chem. 1988,
28, 299.
(4) (a) Arndtsen, B. A.; Bergman, R. G.; Mobley, T. A.; Peterson, T.
H. Acc. Chem. Res. 1995, 28, 154. (b) Schneider, J . J . Angew. Chem.,
Int. Ed. Engl. 1996, 35, 1068. (c) Hall, C.; Perutz, R. N. Chem. Rev.
1996, 96, 3125.
(7) (a) Griffith, W. P. In Comprehensive Coordination Chemistry;
Wilkinson, G., Gillard, R. D., McCleverty, J . A., Eds.; Pergamon
Press: Oxford, U.K., 1987; Vol. 4, p 572, and references therein. (b)
Blake, A. J .; Champness, N. R.; Forder, R. J .; Frampton, C. S.; Frost,
C. A.; Reid, G.; Simpson, R. H. J . Chem. Soc., Dalton Trans. 1994,
3377.
(8) (a) Chakravarty, A. R.; Cotton, F. A.; Tocher, D. A. Acta
Crystallogr. 1985, C41, 698. (b) Hoffman, P. R.; Caulton, K. G. J . Am.
Chem. Soc. 1975, 97, 4221.
(9) (a) Schro¨der, M.; Stephenson, T. A. In Comprehensive Coordina-
tion Chemistry; Wilkinson, G., Gillard, R. D., McCleverty, J . A., Eds.;
Pergamon Press: Oxford, U.K., 1987; Vol 4, p 377, and references
therein. (b) Seddon, E. A.; Seddon, K. R. In The Chemistry of
Ruthenium; Clark, R. J . H., Ed.; Elsevier: Amsterdam, 1984; p 487.
(10) Bennett, M. A.; Longstaff, P. A. J . Am. Chem. Soc. 1969, 91,
6266.
(5) (a) Guari, Y.; Sabo-Etienne, S.; Chaudret, B. Eur. J . Inorg. Chem.
1999, 1047. (b) Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1698. (c)
Shilov, A. E. Activation of Saturated Hydrocarbons by Transition Metal
Complexes; D. Reidel: Dordrecht, The Netherlands, 1984. (d) Activation
and Functionalization of Alkanes; Hill, C. L., Ed.; Wiley: New York,
1989. (e) Selective Hydrocarbon Activation; Davies, J . A., Watson, P.
L., Liebman, J . F., Greenberg, A., Eds.; VCH: Weinheim, Germany,
1990. (f) Applied Homogeneous Catalysis with Organometallic Com-
pounds; Cornils, B., Herrmann, W. A., Eds.; VCH: Weinheim, Ger-
many, 1996; Vol. 2. (g) Bromberg, S. E.; Yang, H.; Asplund, M. C.; Lian,
T.; McNamara, B. K.; Kotz, K. T.; Yeston, J . S.; Wilkens, M.; Frei, H.;
Bergman, R. G.; Harris, C. B. Science 1997, 278, 260.(h) Shilov, A. E.;
Shul’pin, G. B. Chem. Rev. 1997, 97, 2879.
10.1021/om000593m CCC: $20.00 © 2001 American Chemical Society
Publication on Web 12/07/2000

306 Organometallics, Vol. 20, No. 2, 2001
Baratta et al.
Ta ble 1. Selected In ter a tom ic Dista n ces (Å),
An gles (d eg), a n d Tor sion An gles (d eg) for
1‚CH2Cl2
Os-Cl
Os-P1
Os-P2
Os-P3
2.4819(6)
2.3547(7)
2.3597(7)
2.3899(6)
Os-C17
Os-C47
Os-C77
C17-C47
2.166(3)
2.152(3)
2.168(3)
1.437(4)
F igu r e 1.
Cl-Os-P1
Cl-Os-P2
Cl-Os-P3
Cl-Os-C17
Cl-Os-C47
Cl-Os-C77
P1-Os-P2
P1-Os-P3
P1-Os-C17
P1-Os-C47
89.30(2)
92.06(2)
83.55(2)
82.90(7)
121.25(8)
163.31(7)
166.25(3)
97.40(2)
80.06(7)
87.59(7)
P1-Os-C77
P2-Os-P3
91.57(7)
96.35(2)
86.52(7)
80.01(7)
91.05(7)
166.24(7)
154.88(8)
79.81(7)
38.88(10)
P2-Os-C17
P2-Os-C47
P2-Os-C77
P3-Os-C17
P3-Os-C47
P3-Os-C77
C17-Os-C47
C16-C17-C47-C46
134.8(3)
whereas two other phosphines are converted into a
tridentate trans-stilbene-type ligand by cleavage of four
C-H bonds of two methyl groups.
The Os-P1 and Os-P2 distances are 2.3547(7) and
2.3597(7) Å, respectively, and are slightly shorter
compared to the Os-P3 distance 2.3899(6) Å (Table 1)
and to other six-coordinate osmium complexes with
arylphosphines.11
All the osmium-carbon distances are similar and are
in agreement with those reported for alkyl12 and ole-
finic13 osmium(II) complexes. The P1-Os-P2 angle is
166.25(3)°, and the P3-Os-C77 angle is 79.81(7)°,
which probably reflects the geometrical constraints of
the phosphine chelating ligand. The bound olefin has a
C17-C47 distance of 1.437(4) Å, an expected lengthen-
ing on coordination, and the C17, C47, Os, C77, P3, and
Cl atoms are almost coplanar (distance to the mean
plane less than (0.12 Å). Furthermore, the dihedral
angle between the planes C46-C47-C17 and C47-
C17-C16 is 134.8(3)°; the deviation from 180° is likely
to be caused by the tridentate chelation.
F igu r e 2. ORTEP22f representation of compound 1 in the
solid state. Thermal ellipsoids are at the 50% probability
level. Hydrogen atoms are omitted for clarity.
der reflux afforded quantitatively the light green prod-
uct [OsCl{(2-CH2-6-MeC6H3)PPh2}(BDPS)] (1) (eq 1).
In agreement with the solid-state structure of 1, the
31P NMR spectrum of this complex in CDCl3 shows a
1
typical pattern for an ABC system. The H{31P} NMR
spectrum of 1 exhibits two doublets at δ 3.94 and 3.48
with a J (HH) value of 7.9 Hz for the trans-olefinic
protons and two doublets at δ 3.50 and 2.62 with a
J (HH) value of 19.1 Hz for the methylene protons.
To obtain further insight into the mechanism of this
type of carbon double bond formation, we have in-
vestigated the reaction between PPh2(2,6-Me2C6H3) and
the osmium(II) precursor [OsCl2(PPh3)3]. The latter
(11) (a) Wilson, R. D.; Ibers, J . A. Inorg. Chem. 1979, 18, 336. (b)
Bohle, D. S.; J ones, T. C.; Rickard, C. E. F.; Roper, W. R. J . Chem.
Soc., Chem. Commun. 1984, 865. (c) Clark, G. R.; Marsden, K.; Rickard,
C. E. F.; Roper, W. R.; Wright, L. J . J . Organomet. Chem. 1988, 338,
393.
(12) (a) Esteruelas, M. A.; Lahoz, F. J .; Lopez, J . A.; Oro, L. A.;
Schlu¨nken, C.; Valero, C.; Werner, H. Organometallics 1992, 11, 2034.
(b) Bellachioma, G.; Cardaci, G.; Macchioni, A.; Zanazzi, P. Inorg.
Chem. 1993, 32, 547. (c) Gallop, M. A.; J ones, T. C.; Rickard, C. E. F.;
Roper, W. R. J . Chem. Soc., Chem. Commun. 1984, 1002. (d) Lindner,
E.; Wassig, W.; Fawzi, R.; Steimann, M. Angew. Chem., Int. Ed. Engl.
1994, 33, 321.
(13) (a) Edwards, A. J .; Elipe, S.; Esteruelas, M. A.; Lahoz, F. J .;
Oro, L. A.; Valero, C. Organometallics 1997, 16, 3828. (b) J ohnson, T.
J .; Albinati, A.; Koetzle, T. F.; Ricci, J .; Eisenstein, O.; Huffman, J .
C.; Caulton, K. G. Inorg. Chem. 1994, 33, 4966. (c) Pu, L.; Hasegawa,
T.; Parkin, S.; Taube, H. J . Am. Chem. Soc. 1992, 114, 7609. (d)
Wecker, U.; Werner, H.; Peters, K.; von Schnering, H. G. Chem. Ber.
1994, 127, 1021.
It should be noted that no carbonyl abstraction from
2-propanol occurs and that addition of water is neces-
sary to improve solubility of [(NH4)2OsCl6]. The dia-
magnetic complex which was analyzed satisfactorily as
1 is thermally stable and slightly air sensitive in solid
state and in solution. The X-ray analysis (Figure 2)
shows that one phosphine group, PPh2(2,6-Me2C6H3),
has undergone a cyclometalation of one methyl group,

C-C Double Bond Formation in Os Phosphine Complexes
Organometallics, Vol. 20, No. 2, 2001 307
compound reacts with PPh2(2,6-Me2C6H3) in toluene
at reflux to give the complex [OsHCl(PPh3)(BDPS)]
(2), which was isolated in almost quantitative yield
(eq 2).
osmium(II) phosphine complexes17 via R-hydride elimi-
nation.18 A subsequent cyclometalation of a second
phosphine and a C-C coupling19 of the carbene with
the alkyl carbon (a key step in the Fischer-Tropsch
synthesis20), followed by â-hydrogen elimination, can
afford complex 2. It is noteworthy that no formation of
1 was observed in the reaction of [OsCl2(PPh3)3] with
an excess of PPh2(2,6-Me2C6H3), suggesting that the
displacement of PPh3 with the bulkier phosphine can
occur only if a concomitant cyclometalation takes place.
Furthermore, when the reaction of [OsCl2(PPh3)3] with
PPh2(2,6-Me2C6H3) is carried out under 1 atm of CO,
no complexes containing the latter phosphine were
detected. It is likely that the mechanism of the forma-
tion of 1 presents steps similar to those of 2 and may
proceed via hydrido cyclometalated or cyclometalated-
carbene species. The process here reported, together
with that of Bennett,10 may represent an example of an
intriguing mode for the functionalization of activated
methyl groups. Work is in progress to extend this
template synthesis to other metal systems.
Exp er im en ta l Section
The 31P NMR spectrum of 2 reveals an ABX system
with a 2J (PP) value of 297.5 for the trans phosphorus
atoms and 14.5 and 13.2 Hz for the cis ones, which are
values very close to those of 1, thus suggesting a similar
All reactions were carried out under an argon atmosphere
using standard Schlenk techniques. Toluene, heptane, and
diethyl ether were carefully dried by conventional methods and
distilled under argon, while methanol and 2-propanol were
previously degassed before use. Ammonium hexachloroosmate
was purchased from Aldrich Chemical Co., and [OsCl2(PPh3)3]
was prepared according to the literature.21 NMR measure-
ments were carried out using a Bruker AC 200 spectrometer.
Chemical shifts, in ppm, are relative to TMS for 1H and 13C
and to external 85% H3PO4 for 31P. The mass spectrum was
recorded on a Finnigan MAT 90 spectrometer. Elemental
analyses (C, H, N) were performed by the Microanalytical
Laboratory of our department.
1
OsP3 core. Furthermore, in the H NMR spectrum of 2
a proton at δ -13.56, attributable to a hydrido ligand,
is coupled with one olefinic proton and three phosphorus
atoms with J (HP) values of 12.4 and 30.3 Hz, suggesting
that PPh3 is cis to the hydride.14 The 1H{31P} NMR
spectrum of the coordinated trans-olefin shows two
signals at δ 3.98 and 3.39 with a J (HH) value of 7.4
Hz, similar to those of 1, with the first proton coupled
with the hydride (J (HH) value of 3.2 Hz). The compari-
son of the NMR data of 2 and 1 suggests that the two
complexes are geometrically related, and 2 contains a
trans-stilbene-type ligand with one PPh3 trans to the
coordinated olefin to minimize repulsion.
Apparently, the reactions for 1 and 2 are driven to
the right because of the formation of final metal com-
plexes containing a strong chelating tridentate ligand.
However, the mechanism of the C-C coupling reaction
is not obvious, and different routes can be tentatively
suggested. In the formation of 2 from [OsCl2(PPh3)3] it
is reasonable to assume that the primary step proceeds
through displacement of PPh3 with PPh2(2,6-Me2C6H3),
affording a cyclometalated hydridometal intermediate.
The presence of two methyl groups in the ortho position
of PPh2(2,6-Me2C6H3), in addition to the two relatively
bulky gem-phenyl groups, may facilitate the cyclometa-
lation.15 According to the results of Bennett et al. on
rhodium(I) complexes,16 one can assume that a second
cyclometalation occurs, followed by a C-C coupling
(reductive elimination) and dehydrogenation of the CH2-
CH2 chain, giving complex 2. Alternatively, the first
cyclometalated intermediate can convert into a carbene
complex, a process which was proposed by Werner in
P r ep a r a tion of [OsCl{(2-CH2-6-MeC6H3)P P h 2}(BDP S)]
(1). [(NH4)2OsCl6] (200 mg, 0.455 mmol) and PPh2(2,6-
Me2C6H3) (600 mg, 2.07 mmol) were suspended in 10 mL of
2-propanol, and 4 mL of water was added. The mixture was
refluxed for 3 h, affording a light green precipitate, which was
collected by filtration. The product was suspended in methanol
(10 mL) and the suspension stirred for 5 h, and after filtration
the product was dried under reduced pressure. Yield: 430 mg
(87%). Anal. Calcd for C60H52ClOsP3: C, 66.0; H, 4.8. Found:
1
C, 65.8; H, 4.7. H NMR (200.1 MHz, CDCl3, 20 °C, TMS): δ
7.4-6.5 (m, 39H; aromatic protons), 3.94 (m, 1H; dCH), 3.50
(dt, J (HH) ) 19.1 Hz, J (HP) ) 4.9 Hz, 1H; CH2), 3.48 (m, 1H;
dCH), 2.62 (dt, J (HH) ) 19.1 Hz, J (HP) ) 4.8 Hz, 1H; CH2),
1.53 (s, 3H; CH3), 1.07 (s, 3H; CH3), 0.96 (s, 3H; CH3). 13C NMR
(50.3 MHz, CDCl3, 20 °C, TMS): δ 165.2 (d; J (CP) ) 40.3 Hz;
(17) Werner, H.; Weber, B.; Nu¨rnberg, O.; Wolf, J . Angew. Chem.,
Int. Ed. Engl. 1992, 31, 1025.
(18) (a) Koch, J . L.; Shapley, P. A. Organometallics 1999, 18, 814.
(b) Cooper, N. J .; Green, M. L. H. J . Chem. Soc., Dalton Trans. 1979,
1121. (c) Empsall, H. D.; Hyde, E. M.; Markham, R.; McDonald, W. S.;
Norton, M. C.; Shaw, B. L.; Weeks, B. J . Chem. Soc., Chem. Commun.
1977, 589. (d) Schrock, R. R.; Shih, K. Y.; Dobbs, D. A.; Davis, W. M.
J . Am. Chem. Soc. 1995, 117, 6609.
(19) (a) Werner, H.; Stu¨er, W.; Wolf, J .; Laubender, M.; Webern-
do¨rfer, B.; Herbst-Irmer, R.; Lehmann, C. Eur. J . Inorg. Chem. 1999,
1889. (b) Desrosiers, P. J .; Cai, L.; Halpern, J . J . Am. Chem. Soc. 1989,
111, 8513.
(20) (a) Herrmann, W. A. Angew. Chem., Int. Ed. Engl. 1982, 21,
117. (b) Rofer-DePoorter, C. K. Chem. Rev. 1981, 81, 447. (c) Thor, D.
L.; Tulip, T. H. J . Am. Chem. Soc. 1981, 103, 5984. (d) Maitlis, P. M.;
Long, H. C.; Quyoum, R.; Turner, M. L.; Wang, Z.-Q. J . Chem. Soc.,
Chem. Commun. 1996, 1.
(21) Elliott, G. P.; McAuley, N. M.; Roper, W. R. Inorg. Synth. 1989,
26, 184.
(14) Ahmad, N.; Robinson, S. D.; Uttley, M. F. J . Chem. Soc., Dalton
Trans. 1972, 843.
(15) Shaw, B. L. J . Organomet. Chem. 1980, 200, 307.
(16) (a) Bennett, M. A.; Clark, P. W.; Robertson, G. B.; Whimp, P.
O. J . Chem. Soc., Chem. Commun. 1972, 1011. (b) Robertson, G. B.;
Tucker, P. A.; Whimp, P. O. Inorg. Chem. 1980, 19, 2307.

308 Organometallics, Vol. 20, No. 2, 2001
Baratta et al.
Ta ble 2. Cr ysta llogr a p h ic Da ta for 1‚CH2Cl2
Crystals of the complex 1‚CH2Cl2 suitable for an X-ray
structure determination were grown from a saturated solution
of 1 in a 1:1 mixture of dichloromethane and heptane. Pre-
liminary examination and data collection were carried out on
a Kappa-CCD system (Nonius Mach3) equipped with a rotat-
ing anode (NONIUS FR591; 50 kV; 60 mA; 3.0 kW) and
graphite-monochromated Mo KR radiation (λ ) 0.710 73 Å).
Data collection were performed at 163 K with an exposure time
of 40 s per film (æ and Ω-scans, oscillation modus, ∆æ/∆Ω )
1.0°). A total of 57 109 reflections were collected.22a After
merging a sum of 10 557 independent reflections remained,
which were used for all calculations. Data were corrected for
Lorentz and polarization effects. Corrections for absorption and
decay effects were not applied. The unit cell parameters were
obtained by full-matrix least-squares refinements of 61 468
reflections with the program Scalepack.22b The structure was
solved by a combination of direct methods and difference
Fourier syntheses.22c All non-hydrogen atoms of the asym-
metric unit were refined with anisotropic thermal displace-
ment parameters. All hydrogen atoms, except those of the
solvent molecule, were found in the difference Fourier map
and refined freely with individual isotropic thermal displace-
ment parameters. The hydrogen atoms of the solvent were
calculated in ideal positions riding on the parent carbon atom.
Full-matrix least-squares refinements were carried out by
chem formula
fw
C60H52ClOsP3‚CH2Cl2
1176.58
color/shape
cryst size (mm)
cryst syst
space group
a (Å)
light green/fragment
0.38 × 0.30 × 0.25
monoclinic
P21/ n (No. 14)
12.7810(1)
18.9967(2)
21.4222(2)
90.375(6)
b (Å)
c (Å)
â (deg)
V (Å3)
5201.13(8)
4
Z
T (K)
163
1.503
2.738
2368
Fcalcd (g cm-3
)
µ (mm-1
F000
)
θ range (deg)
3.35-26.35
(15, (23, (26
57 109
10 557/0.032
9443
data collcd (h,k,l)
no. of rflns collcd
no. of indep rflns/Rint
no. of obsd rflns (I > 2σ(I))
no. of params refined
R1 (obsd/all)
828
0.0242/0.0279
0.0658/0.0671
1.118/1.074
+1.02/-1.24
wR2 (obsd/all)
GOF (obsd/all)
max/min ∆F (e Å-3
)
2
2 2
minimizing ∑w(Fo - Fc
) with the SHELXL-97 weighting
scheme and stopped at a maximum shift/error of <0.001.22d
Neutral atom scattering factors for all atoms and anomalous
dispersion corrections for the non-hydrogen atoms were taken
from ref 22e. All other calculations (including ORTEP graph-
ics) were done with the program PLATON.22f Calculations were
performed on a PC workstation (Intel Pentium II) running
LINUX.
CCH2), 159.5-158.5 (m; CCHd), 143.9 (s; CMe), 143.1 (s;
CMe), 142.3 (s; CMe), 137.3-124.6 (m; aromatic carbons), 74.9
(d, J (CP) ) 16.9 Hz; dCH), 74.5 (d, J (CP) ) 9.8 Hz; dCH),
24.5 (s; CH3), 21.4 (s; CH3), 21.0 (s; CH3), 12.4 (s; CH2). 31P
NMR (81.0 MHz, CDCl3, 20 °C, H3PO4): ABC spin system δ
11.6 (dd, J (PP) ) 311.1 Hz, J (PP) ) 14.8 Hz; PA), 10.0 (dd,
J (PP) ) 311.1 Hz, J (PP) ) 13.3 Hz; PB), 9.4 (dd, J (PP) ) 14.7
Hz, J (PP) ) 13.3 Hz; PC).
P r ep a r a tion of [OsHCl(P P h 3)(BDP S)] (2). [OsCl2(PPh3)3]
(337 mg, 0.321 mmol) and PPh2(2,6-Me2C6H3) (200 mg, 0.689,
mmol) were suspended in 5 mL of toluene, and the mixture
was refluxed for 1 h. The solvent was evaporated, and the oily
product was treated with heptane, affording a light brown
precipitate. The product was washed with diethyl ether (0 °C),
filtered off, and dried under reduced pressure. Yield: 250 mg
(73%). Anal. Calcd for C58H50ClOsP3: C, 65.4; H, 4.7. Found:
Ack n ow led gm en t. This work was supported by the
Ministero dell’Universita` e della Ricerca Scientifica e
Tecnologica (MURST), Regione Friuli Venezia Giulia,
and the Bayerische Forschungsstiftung (FORKAT; X-
ray equipment).
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
and data collection parameters, atomic coordinates, bond
lengths, bond angles, and thermal displacement parameters
for 1‚CH2Cl2 in CIF format. This material is available free of
charge via the Internet at http://pubs.acs.org.
1
C, 65.3; H, 4.7. H NMR (200.1 MHz, CDCl3, 20 °C, TMS): δ
7.7-6.5 (m, 41H; aromatic protons), 3.98 (m, 1H; dCH), 3.39
(m, 1H; dCH), 1.24 (s, 3H; CH3), 1.01 (s, 3H; CH3), -13.56
(dtd, J (PH) ) 30.3 Hz, J (PH) ) 12.4 Hz, J (HH) ) 3.2 Hz, 1H;
OsH). 13C NMR (50.3 MHz, CDCl3, 20 °C, TMS): δ 161.0-
159.5 (m; CCHd), 142.9 (s; CMe), 142.5 (s; CMe), 136.0-124.5
(m; aromatic carbons), 65.2 (d, J (CP) ) 22.9 Hz; dCH), 62.9
(s broad; dCH), 21.4 (d, J (CP) ) 2.9 Hz; CH3), 21.0 (d, J (CP)
) 2.4 Hz; CH3). 31P NMR (81.0 MHz, CDCl3, 20 °C, H3PO4):
ABX spin system δ 21.7 (dd, J (PP) ) 297.5, J (PP) ) 14.5 Hz;
PA) 11.4 (dd, J (PP) ) 297.5, J (PP) ) 13.2 Hz; PB), -5.7 (dd,
J (PP) ) 14.5 Hz, J (PP) ) 13.2 Hz; PX). MS (CI): m/z (%) 1065
(5) [M+ - H], 805 (8) [M+ - H - PPh3], 262 (100) [PPh3].
OM000593M
(22) (a) Data Collection Software for Nonius Kappa-CCD, Delft, The
Netherlands, 1997. (b) Otwinowski, Z.; Minor, W. Processing of X-ray
Diffraction Data Collected in Oscillation Mode. In Methods in Enzy-
mology; Carter, W. C., J r., Sweet, R. M., Eds.; Academic Press: New
York, 1996; Vol. 207, p 307. (c) Altomare, A.; Cascarano, G.; Giacovazzo,
C.; Guagliardi, A.; Burla, M. C.; Polidori, G.; Camalli, M. SIR92. J .
Appl. Crystallogr. 1994, 27, 435-436. (d) Sheldrick, G. M. SHELXL-
97; University of Go¨ttingen, Go¨ttingen, Germany, 1998. (e) Interna-
tional Tables for Crystallography; Wilson, A. J . C., Ed.; Kluwer
Academic: Dordrecht, The Netherlands, 1992; Vol. C, Tables 6.1.1.4
(pp 500-502), 4.2.6.8 (pp 219-222), and 4.2.4.2 (pp 193-199). (f) Spek,
A. L. PLATON, A Multipurpose Crystallographic Tool; Utrecht Uni-
versity, Utrecht, The Netherlands, 1999.
X-r a y Str u ctu r e Deter m in a tion of th e Com p lex 1‚
CH2Cl2. Details of the X-ray experiment, data reduction, and
final structure refinement calculations are summarized in
Table 2.