Synthesis and reactivity of osmium(VI) thiolate complexes, [Os(N)(CH2SiMe3)2(μ-SR)]2 and [Os(N)(SCH2Ph)4]-

Article abstract of DOI:10.1021/om960491p

Primary, secondary, and tertiary alkanethiolate complexes of osmium(VI) possessing bridging thiolate ligands have been prepared and characterized. The complexes [Os(N)-(CH₂SiMe₃)₂(μ-SR)]₂ (R = CH₂CH₃, CMe₃, CHMe₂, CH₂CHMe₂, CH₂Ph) are synthesized by the reaction of [Os(N)(CH₂SiMe₃)₂Cl]₂ with alkali metal thiolates. They are air- and water-stable and unreactive toward nucleophiles and electrophiles. Anionic tetrathiolate and tetraalkoxide complexes of osmium(VI) have also been prepared and characterized. Reaction of [PPh₄][Os(N)Cl₄] with NaSCH₂Ph or LiOCH₂Ph in refluxing THF produces [PPh₄]-[Os(N)(SCH₂Ph)₄] or [PPh₄][Os(N)(OCH₂Ph)₄]. Thermolysis of [PPh₄][Os(N)(SCH₂Ph)₄] gives benzyl disulfide, probably via reductive elimination, while the tetraalkoxide complex produces benzaldehyde and benzyl alcohol upon heating in a β-hydrogen elimination reaction.

Full text of DOI:10.1021/om960491p

5090
Organometallics 1996, 15, 5090-5096
Syn th esis a n d Rea ctivity of Osm iu m (VI) Th iola te
Com p lexes, [Os(N)(CH2SiMe3)2(µ-SR)]2 a n d
[Os(N)(SCH2P h )4]-
Patricia A. Shapley* and William A. Reinerth
Department of Chemistry, University of Illinois, Urbana, Illinois 61801
Received J une 18, 1996X
Primary, secondary, and tertiary alkanethiolate complexes of osmium(VI) possessing
bridging thiolate ligands have been prepared and characterized. The complexes [Os(N)-
(CH2SiMe3)2(µ-SR)]2 (R ) CH2CH3, CMe3, CHMe2, CH2CHMe2, CH2Ph) are synthesized by
the reaction of [Os(N)(CH2SiMe3)2Cl]2 with alkali metal thiolates. They are air- and water-
stable and unreactive toward nucleophiles and electrophiles. Anionic tetrathiolate and
tetraalkoxide complexes of osmium(VI) have also been prepared and characterized. Reaction
of [PPh4][Os(N)Cl4] with NaSCH2Ph or LiOCH2Ph in refluxing THF produces [PPh4]-
[Os(N)(SCH2Ph)4] or [PPh4][Os(N)(OCH2Ph)4]. Thermolysis of [PPh4][Os(N)(SCH2Ph)4] gives
benzyl disulfide, probably via reductive elimination, while the tetraalkoxide complex produces
benzaldehyde and benzyl alcohol upon heating in a â-hydrogen elimination reaction.
In tr od u ction
complexes are known for many of the transition metals
in groups 4-8.6
Thiolate ligands are extensively employed in transi-
tion metal chemistry and the versatility of sulfur as a
ligand in organotransition metal chemistry has been
widely established.1 Alkane- or arenethiolates can bond
to one, two, or three metal atoms using one, three, or
five electrons, respectively, to interact with the metal
centers.2 Sulfur-containing species are extensively used
as catalysts for hydrogenation, hydrodesulfurization,
hydrodenitrification, isomerization, and dehydration of
fossil fuels.3 Sulfur-containing amino acids and pep-
tides act as ligands to transition metals in metallo-
proteins such as isopenicillin N-synthetase, blue copper
proteins, cytochromes, iron-sulfur proteins, and several
molybdenum-containing enzymes including sulfite oxi-
dase and xanthine oxidase.4
We have been interested in the chemistry of high
oxidation state organometallic complexes of the iron
triad metals possessing sulfur-containing ligands and
have prepared several stable ruthenium(VI) and osmi-
um(VI) complexes possessing thiolate ligands. These
including [N(n-Bu)4][M(N){HNC(O)CH2CH2S}2] (M )
Ru, Os),7 cis- and trans-[Os(N)(CH2SiMe3)2(2-S-NC5H4)]2
and cis-[NBu4][Os(N)(CH2SiMe3)2(η2-SCH2CH2S)].8 We
present here the synthesis and reaction chemistry of a
series of organoosmium(VI) thiolate complexes. In
addition, we have prepared osmium(VI) tetrathiolate
and tetraalkoxide complexes and compared their ther-
mal decomposition reactions.
Resu lts
Thiolates form very strong bonds to transition metals
because of sulfur’s polarizability and the availability of
electron pairs on the ligand for π-donation.5 π-donation
from sulfur to the metal can stabilize oxidized transition
metal centers, so high oxidation state metal-thiolate
Syn th esis of Or gan oosm iu m (VI) µ-Th iolate Com -
p lexes. The addition of NaSCH2CH3 to a methylene
chloride solution of [Os(N)(CH2SiMe3)2Cl]2 causes the
color to change from orange to golden yellow as NaCl
precipitates. Removal of the solvent gives an orange
oil. Analytically pure [Os(N)(CH2SiMe3)2(µ-SCH2CH3)]2,
1, can be obtained in approximately 70% yield as a
yellow powder from concentrated acetonitrile solutions
at -30 °C (Scheme 1).
X Abstract published in Advance ACS Abstracts, November 1, 1996.
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121-185. (b) Stephan, D. W.; Nadasdi T. T. Coord. Chem. Rev. 1996,
147, 147-208.
Complex 1 was characterized by 1H and 13C NMR
spectroscopy, IR, mass spectroscopy, and elemental
(2) Dance, I. G. Polyhedron 1986, 5, 1037-1104.
(3) (a) Mitchell, P. C. H. Catalysis; Kemball, C., Ed.; The Chemical
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(4) (a) Dickerson, R. E.; Timkovich, R. The Enzymes, 3rd ed.;
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Lovenberg, W., Ed.; Academic: New York, 1973, Vol. 1; 1974, Vol. 2;
1976, Vol. 3. (c) Averill, B. A.; Orme-J ohnson, W. H. Metal Ions in
Biological Systems; Siget, H., Ed.; Dekker: New York, 1978; Vol. 7,
pp 178-184. (d) Coon, M. J .; White, R. E. Metal Ion Activation of
Dioxygen; Spiro, T. G., Ed.; Wiley: New York, 1980; p 73. (e) Bennett,
L. E. Prog. Inorg. Chem. 1973, 18, 1-176. (f) Holm, R. H. Acc. Chem.
Res. 1977, 10, 427. (g) Boyd, I. W.; Dance, I. G.; Murray, K. S.; Wedd,
A. G. Aust. J . Chem. 1978, 31, 279-284. (h) White, R. E.; Coon, M. J .
Ann. Rev. Biochem. 1980, 49, 315. (i) Hanson, G. R.; Brunette, A. A.;
McDonell, A. C.; Murray, K. S.; Wedd, A. G. J . Am. Chem. Soc. 1981,
103, 1953-1959. (j) Hollander, I. J .; Shen, Y. Q.; Heim, J .; Demin, A.
L.; Wolf, S. Science 1984, 224, 610-612. (k) Gowik, P. K.; Klapoetke,
T. M. Inorg. Chim. Acta 1990, 169, 1-3. (l) Ueyama, N.; Oku, H.;
Nakamura, A. J . Am. Chem. Soc. 1992, 114, 7310-7311.
(6) Examples of oxidized metal thiolate complexes include: (a)
Buchwald, S. L.; Nielsen, R. B.; Dewan, J . C. J . Am. Chem. Soc. 1987,
109, 1590-1591. (b) Buchwald, S. L.; Nielsen, R. B. J . Am. Chem. Soc.
1988, 110, 3171-3175. (c) Curnow, O. J .; Curtis, M. D.; Rheingold,
A.; Haggerty, B. S. Inorg. Chem. 1991, 30, 4043-4047. (d) Koch, S.
A.; Millar, M. J . Am. Chem. Soc. 1983, 105, 3362-3363. (e) Sellmann,
D.; Geck, M.; Knoch, F.; Ritter, G.; Dengler, J . J . Am. Chem. Soc. 1991,
113, 3819-3828. (f) Sellmann, D.; Geck, M.; Knoch, F.; Moll, M. Inorg.
Chim. Acta 1991, 186, 187-198. (g) Herrmann, W. A. Inorg. Chem.
1991, 30, 2165-2170. (h) Herrmann, W. A. J . Chem. Soc., Dalton
Trans. 1991, 797-804. (i) Arroyo, M.; Chamizo, J . A.; Hughes, D. L.;
Richards, R. L.; Roman, P.; Sosa, P.; Torrens, H. J . Chem. Soc., Dalton
Trans. 1994, 1819-1824.
(7) Schwab, J . J .; Wilkinson, E. C.; Wilson, S. R.; Shapley, P. A. J .
Am. Chem. Soc. 1991, 113, 6124-6129.
(8) Shapley, P. A.; Zhang, N.; Wilson, S. R. Organometallics 1988,
7, 1126-1131.
(5) Caulton, K. New J . Chem. 1994, 18, 25-41.
S0276-7333(96)00491-8 CCC: $12.00 © 1996 American Chemical Society

Osmium(VI) Thiolate Complexes
Organometallics, Vol. 15, No. 24, 1996 5091
Sch em e 1
Sch em e 2
pane-2-thiolate complex is prepared as a mixture of 2
isomers with the major isomer, 2a , comprising 87% of
the total. In each isomer, the 4 alkyl groups are
equivalent with diastereotopic methylene protons and
the two 2-methylpropane-2-thiolate ligands are equiva-
lent. Two isomers of 3 are formed when the compound
is synthesized from LiSCHMe2 and [Os(N)(CH2SiMe3)2-
Cl]2 (3a , 78%; 3b, 22%) but 3 isomers are produced when
the compound is synthesized using a base and the thiol
(3a , 61%; 3b, 13%, 3c, 26%). Each of the isomers of 3
have equivalent alkyl groups with diastereotopic meth-
ylene protons and each have equivalent propane-2-
thiolate ligands. In isomer 3c, the methyl groups on
the thiolate ligands are diastereotopic while in 3a and
3b the corresponding methyl groups are equivalent.
Compound 4 is prepared as a single isomer from
reaction of the osmium chloride with HSCH2CHMe2 and
KOCMe3 but is formed as a 1:1 mixture of 2 isomers
with LiSCH2CHMe2. Complex 4a has equivalent alkyls
with diastereotopic methylene protons. The thiolate
ligands are also equivalent, but the R protons and â
methyl groups on the 2-methylpropanethiolate ligands
are diastereotopic. The reaction of [Os(N)(CH2SiMe3)2-
Cl]2 with KOCMe3 and HSCH2Ph gives two isomers.
Complexes 5a ,b are formed in variable ratios depending
on reaction conditions. A single isomer, 5b, is formed
in the reaction between [Os(N)(CH2SiMe3)2Cl]2 and
1
analysis. The H NMR spectrum shows the presence
of two isomers: 1a (85%) and 1b (15%). For each
isomer, all four (trimethylsilyl)methyl ligands are equiva-
lent and both ethanethiolate ligands are equivalent. The
R-protons of the (trimethylsilyl)methyl ligands are dia-
stereotopic. In 1a the R-protons of the ethanethiolate
groups are diastereotopic while in 1b they are equiva-
lent. The major isomer, 1a , exhibits two doublets of
quartets for the methylene protons as well as a broad
triplet for the methyl protons of the ethanethiolate
ligand. There are also 2 doublets and a singlet char-
acteristic of the (trimethylsilyl)methyl ligands. For the
ethanethiolate protons of 1b are a quartet and a broad
triplet. Two doublets and a singlet for the (trimethyl-
silyl)methyl protons are clearly visible for 1b. The
13C{1H} NMR spectrum includes 2 resonances for the
ethanethiolate methylene and methyl carbons and 2
resonances for the methylene and methyl carbons of the
(trimethylsilyl)methyl ligands of 1a . There are 4 peaks
in the 13C NMR spectrum of 1b for the corresponding
carbons. The IR spectrum of 1 shows bands associated
with the (trimethylsilyl)methyl and ethyl thiolate ligands
in addition to a band at 1111 cm-1 assigned to the OstN
stretching vibration. This compares well with the
osmium-nitrogen stretching vibrations of other neutral
nitridoosmium(VI) thiolate complexes possessing similar
ligand environments.
The reactions of [Os(N)(CH2SiMe3)2Cl]2 with the
lithium or sodium salts of 2-methylpropane-2-thiolate,
propane-2-thiolate, 2-methylpropanethiolate, and benzyl
thiolate, result in the formation of thiolate-bridged
bimetallic complexes of the form [Os(N)(CH2SiMe3)2(µ-
SR)]2 (R ) CMe3, 2; CHMe2, 3; CH2CHMe2, 4; CH2Ph,
5) in good yield. Complexes 1-5 can also be prepared
by treatment of [Os(N)(CH2SiMe3)2Cl]2 with the corre-
sponding thiol and a base such as KOCMe3 or NEt3
(Scheme 2).
The NMR and IR spectra of complexes 2-5 are
similar to those obtained for 1. The thiolate R-protons
for 3-5 fall between 3 and 5 ppm. The 13C{1H} NMR
spectra for 3-5 include resonances for the R-carbon of
the thiolate ligand between 30 and 40 ppm. The
osmium-nitrogen stretching vibration in the IR spectra
of 2-5 fall in a very narrow range, from 1114 to 1117
cm-1, showing that the amount of electron density at
osmium is similar for all of these complexes.
1
LiSCH2Ph. The H NMR shows that 5b has equivalent
alkyls and equivalent thiolate ligands with dia-
stereotopic R-protons on each. The R-protons on the
alkyl groups and on the benzyl thiolate ligands are
multiplets in the 1H NMR, indicating that these groups
are not equivalent.
The neutral thiolate complexes are stable toward air
and water. They are thermally stable, decomposing
near 150 °C in the solid state, while in solution they
decompose slowly at 120 °C. They exist as yellow or
orange solids or oils and are soluble in a wide variety
of organic solvents including methylene chloride, ether,
and hexane.
Rea ction s of Or ga n oosm iu m (VI) Th iola te Com -
p lexes. Complexes 1-5 are coordinately unsaturated,
16-electron, dimers. They might be expected to react
with donor molecules to form stable monomeric thiolate
complexes. The bridging chloride complex [Os(N)(CH2-
SiMe3)2Cl]2 reacts readily with pyridine, PPh3, or dppe
to form monomeric adducts, Os(N)(CH2SiMe3)2(L)Cl (L
) NC5H5, PPh3, dppe).9 We have observed no reaction
between any of the complexes 1-5 and any amine or
arylphosphine. In particular we have monitored the
Like 1, each of the µ-thiolate complexes can be
prepared as a mixture of isomers. The 2-methylpro-

5092 Organometallics, Vol. 15, No. 24, 1996
Shapley and Reinerth
Sch em e 3
Heating a mixture of NaSCH2Ph and [PPh4][Os(N)-
Cl4] in THF to reflux causes the color of the solution to
change from pink to golden-yellow and a white solid to
precipitate. The product, [PPh4][Os(N)(SCH2Ph)4], 6,
can be isolated in 55% yield as bright orange crystals.
Reaction of [PPh4][Os(N)Cl4] with excess LiOCH2Ph, in
refluxing THF, leads to formation of the analogous
tetraalkoxide complex [PPh4][Os(N)(0CH2Ph)4],
7
(Scheme 3). Both of these compounds are air- and
moisture-stable and soluble in organic solvents such as
CH2Cl2 and THF. Treatment of [N(n-Bu)4][Os(N)-
(OSiMe3)4] with an excess quantity of PhCD2OH gave
[N(n-Bu)4][Os(N)(OCD2Ph)4], 8.
F igu r e 1. Partial 1H NMR spectrum of [Os(N)(CH2-
SiMe3)2(µ-SCH2Ph)]2.
Complexes 6-8 were characterized by IR, NMR
spectroscopy, and elemental analysis. The 1H NMR
spectrum of 6 shows a sharp singlet at δ 4.24 for the
methylene protons of the four equivalent thiolate ligands,
while 7 exhibits a singlet at 4.64 for the alkoxide
methylene protons. A singlet is also observed in the
13C{1H} NMR spectrum of 6 at 31.8 ppm for the benzylic
carbons of the thiolate ligands. Complex 7 exhibits a
singlet at 65.0 ppm in the 13C{1H} NMR spectrum. The
osmium-nitrogen stretching vibration in the IR spec-
trum of both complexes is obscured by the very strong
P-C bending mode of the cation.
interaction of 5 with pyridine, PPh3, or TMEDA under
conditions where solvent, concentration of donor mol-
ecule, and temperature have been varied and have no
evidence of reaction prior to the thermal decomposition
of 5.
We have previously shown that nitridoosmium(VI)
thiolates and sulfides react with electrophiles at sulfur
rather than at the nitride ligand. For example, reaction
of the anionic dithioethane complex, [NBu4][Os(N)-
(CH2SiMe3)2(η2-SC2H4S)], with (methyl)trifluoromethane
sulfonate yields the neutral thiolate-thioether complex,
Os(N)(CH2SiMe3)2(η2-SC2H4SMe). However, complex 5
does not react with protic acids or with Me3SiOSO2CF3.
There is no reaction between 5 and KOBut, NaH, or
[N(n-Bu)4][OH].
Heating the osmium thiolate complexes in toluene-
d8 at 115-120 °C results in their slow decomposition.
Decomposition of 1 produces Me4Si, Me3SiCH2CH2-
SiMe3, and an insoluble osmium species. Heating 5a
in CDCl3 at 115-120 °C led to its complete conversion
to 5b. Continued heating produced small amounts of
Me4Si and PhCH2SSCH2Ph.
Syn t h esis of Tet r a t h iola t e a n d Tet r a a lk oxid e
Com p lexes. Thermal decomposition of metal alkane-
thiolate complexes could proceed by several pathways
analogous to the common decomposition pathways of
metal alkyl complexes. Decomposition studies of com-
plexes 1-5 are complicated by reactions of the alkyl
ligands. In order to study thermolysis of the osmi-
um(VI) thiolate moiety, we prepared a related thiolate
complex without alkyl ligands, [Os(N)(SCH2Ph)4]-. We
also prepared [Os(N)(OCH2Ph)4]- so that decomposition
of the thiolate ligand could be compared directly with
the corresponding alkoxide ligand.
Samples of 6 and of 7 were dissolved in toluene-d8,
sealed in NMR tubes under nitrogen, and heated to 70-
90 °C. Thermolysis of 6 under these conditions led to
the formation of benzyl disulfide, presumably via reduc-
tive elimination of the thiolate ligands. There was no
thiol, PhCH2SH(D), produced. However, thermolysis of
7 led to the formation of benzaldehyde and benzyl
1
alcohol in a 1:1 molar ratio as confirmed by H NMR
and gas chromatographic analysis. No other organic
products were detected. Thermolysis of a 1:1 mixture
of [PPh4][Os(N)(OCH2Ph)4] and [N(n-Bu)4][Os(N)(OCD2-
Ph)4] under the same conditions produced only PhCHO,
PhCDO, PhCH2OH(D), and PhCD2OH(D). None of the
monodeuterated alcohol, PhCHDOH, was produced.
Discu ssion
The dimeric structures of organoosmium(VI) thiolate
complexes 1-5 are not surprising given the known
tendency for sulfur ligands to bridge two or even three
osmium centers. Closely related µ-hydroxo complexes,
[M(N)(CH2SiMe3)2(µ-OH)]2 (M ) Os, Ru), have been
prepared, and the structure of the ruthenium complex
was determined by X-ray crystallography.10 These
compounds also exist as mixtures of isomers (Figure 2).
(9) (a) Shapley, P. A.; Marshman, R. M.; Shusta, J . M.; Gebeyehu,
Z.; Wilson, S. R. Inorg. Chem. 1994, 33, 498-502. (b) Shusta, J . M.
Ph.D. Thesis, University of Illinois at Urbana-Champaign, 1993.
(10) Shapley, P. A.; Schwab, J . J .; Wilson, S. R. J . Coord. Chem.
1994, 32, 213-232.

Osmium(VI) Thiolate Complexes
Organometallics, Vol. 15, No. 24, 1996 5093
have a trans-anti structure. With its inequivalent
alkyl groups and diastereotopic 2-methylpropane-
thiolate R-protons and â-methyl groups, 4b should have
a trans-syn structure. The benzyl thiolate complex also
probably exists as a mixture of trans-anti (5b) and
trans-syn (5a ) isomers. The kinetic product would
isomerize to the thermodynamically favored product
through the inversion of one bridging sulfur.
â-Hydrogen elimination is a common pathway for the
decomposition of transition metal alkyl complexes.
While nitridoosmium(VI) alkyl complexes are thermally
stable for those alkyls that do not have â-hydrogen
atoms, the osmium ethyl complex [N(n-Bu)4][Os(N)(CH2-
CH3)4] decomposes at room temperature in solution to
give ethene and a mixture of osmium hydrides.15
â-Hydrogen elimination is also a major route to the
decomposition of metal-alkoxide complexes for those
alkoxides bearing â-protons.16 Similar reactions of
metal-thiolate complexes are much more rare.17 Metal
thioaldehyde complexes have been prepared by hydride
abstraction rather than â-hydrogen elimination.18 Thio-
late complexes have several possible decomposition
pathways including S-C bond scission19 and M-S
homolysis20 or reductive elimination.21
While complexes 6 and 7 are similar, thermal decom-
position of these complexes follows different pathways.
As previously noted, thermolysis of 6 leads to disulfide
formation via what appears to be a reductive elimina-
tion mechanism (Scheme 4). An alternative to a reduc-
tive elimination mechanism is homolysis of the Os-S
bond to generate a relatively stable, sulfur-based radi-
cal. This radical could cause homolysis of another Os-S
bond or dimerize, both of which would result in disulfide
formation. In addition, abstraction of a hydrogen atom
from the solvent by this radical would lead to formation
of benzyl thiol. We do not favor this radical mechanism
because no thiol is produced when 6 is heated to
decomposition in toluene.
Heating 7 in either toluene-d8 or acetone-d6 solutions
generates benzaldehyde and benzyl alcohol as the only
organic products, and these are always formed in an
equimolar ratio. If alkoxy radicals were intermediate
in this reaction, some hydrogen abstraction from solvent
should increase the percentage of alcohol relative to
aldehyde in the product mixture. Thermolysis of a
mixture of â-deuterated and nondeuterated alkoxides
showed no deuterium scrambling of products indicating
that the reaction is intramolecular. The data are
consistent with a â-hydrogen elimination mechanism
(Scheme 5). The lone pairs of electrons on the other
F igu r e 2. Isomers of [Ru(N)(CH2SiMe3)2(µ-OH)]2.
The minor cis isomer has nitrido ligands on the same
side of the molecule, while the major trans isomer has
the nitrido ligands on opposite sides of the molecule.
The ability of sulfur ligands to bridge osmium(VI)
centers has been well established.8,11,12 The interaction
between the osmium atoms and the bridging sulfur is
strong. This is demonstrated by our failure to prepare
neutral, monomeric organoosmium(VI) thiolate com-
plexes by the reaction of Os(N)(CH2SiMe3)2(py)Cl with
1 equiv of NaSCH2Ph or by treatment of 5 with excess
pyridine.
The 1H NMR spectra of the isomers of 1-5 allow
tentative assignments of their structures. The five
possible stereoisomers for any of the compounds
[Os(N)R′2(µ-SR)]2 are shown in Figure 3. NMR studies
have been used to characterize isomers of zirconium
µ-thiolate complexes.13 As in [Ru(N)(CH2SiMe3)2(µ-
OH)]2, the nitrido ligands can have a trans or cis
orientation with respect to one another. The orientation
of the S-alkyls with respect to one another is indicated
by syn or anti. Of these, only the cis-syn isomers would
have equivalent alkyl ligands and equivalent thiolate
groups. For R ) CH2CH3, CH2CHMe2, and CH2Ph the
R-protons of the thiolate ligands would be equivalent
for the cis-syn isomers but would be diastereotopic for
each of the other isomers. The thiolate ligands would
be inequivalent for the cis-anti isomer. There should
be 2 sets of different alkyl groups in the trans-anti,
trans-syn, and cis-anti isomers. A concerted inversion
of the sulfur atoms of both thiolate ligands would
equilibrate the alkyl groups. Inversion of only one
thiolate ligand would interconvert trans-anti with
trans-syn and cis-anti with the cis-syn isomers.
Similar isomerizations of other bridging thiolate com-
plexes have been proposed to occur through sulfur
inversion.14 Interconversion of cis and trans forms could
only take place through a pathway in which at least one
Os-S bond breaks. Studies with various nucleophiles
show that such a dissociation does not occur.
With equivalent alkyl groups and diastereotopic
ethanethiolate R-protons, 1a most likely has a trans-
anti structure, and the minor isomer, 1b, with the
equivalent ethanethiolate R-protons is one of the cis-
syn isomers. Isomers 3a ,b have equivalent propane-2-
thiolate methyl groups and must have cis-syn struc-
tures. For steric reasons, major isomer is probably cis-
syn-2. Isomer 3c has equivalent alkyl groups and
diastereotopic propane-2-thiolate methyl groups and
most likely has a trans-anti structure. Isomer 4a with
equivalent alkyl groups and diastereotopic 2-methyl-
propanethiolate R-protons and â-methyl groups should
(15) Own, Z. Y. Ph.D. Thesis, University of Illinois at Chicago, 1986.
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1986, 5, 390-391. (b) Hoffman, D. M.; Lappas, D.; Wierda, D. A. J .
Am. Chem. Soc. 1989, 111, 1531-1533. (c) Saura-Llamas, I.; Garner,
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N.; Wilson, S. R. Organometallics 1994, 13, 3351.
(12) Shapley, P. A.; Gebeyehu, Z.; Zhang, N.; Wilson, S. R. Inorg.
Chem. 1993, 32, 5646-5651.
(13) Heyn, R. H.; Stephan, D. W. Inorg. Chem. 1995 34, 2804-2812.
(14) (a) Abel, E. W.; Farrow, G. W.; Orrell, K. G. J . Chem Soc.,
Dalton Trans. 1977, 42-46. (b) Natile, G.; Maresca, L.; Bor, G. Inorg.
Chim. Acta 1977, 23, 37-42. (c) Killops, S. D.; Knox, S. A. R. J . Chem
Soc., Dalton Trans. 1978, 1260-1269.

5094 Organometallics, Vol. 15, No. 24, 1996
Shapley and Reinerth
F igu r e 3. Possible stereoisomers of [Os(N)(CH2SiMe3)2(µ-SR)]2.
Toluene was distilled from Na. Deuterated chloroform was
distilled from CaH2 and stored over 4 Å molecular sieves before
use. The compounds [PPh4][Os(N)Cl4]23 and [Os(N)(CH2-
Sch em e 4
24
SiMe3)2Cl]2 were prepared according to literature methods.
NMR spectra were recorded on one of the following
spectrometers: GE QE300, Varian U-400, or GE GN500 FT
NMR. IR spectra were recorded on a Perkin-Elmer 1600 series
FTIR spectrophotometer. Electronic spectra were recorded on
a Hewlett Packard 8452A diode array UV-visible spectropho-
tometer. Gas chromatographic experiments were performed
on a Hewlett Packard 5790 Series gas chromatograph. Ele-
mental analyses were performed by the University of Illinois
School of Chemical Sciences Microanalytical Laboratory. Mass
spectra were recorded on a VG 70-VSE by the University of
Illinois School of Chemical Sciences Mass Spectrometry Labo-
ratory.
Sch em e 5
Syn t h esis of [Os(N)(CH 2SiMe3)2(µ-SCH 2CH 3)]2, 1.
NaSC2H5 (0.008 g, 0.070 mmol) was added to a solution of
[Os(N)(CH2SiMe3)2Cl]2 (0.033 g, 0.040 mmol) in 20 mL of
CH2Cl2 with stirring. The reaction mixture was stirred for
45 min during which time the solution changed from orange
to yellow and white solid precipitated. The solution was
filtered through Celite, and the solvent was removed from the
filtrate in vacuum to give a yellow oil. The oil was dissolved
in 1 mL of CH3CN, and the solution was cooled to 30 °C. A
fine, yellow solid (0.026 g, 0.030 mmol, 74%) precipitated. This
was collected by filtration and dried under vacuum. Mp: 60-
62 °C; 150 °C (dec). IR (KBr pellet, cm-1): 2946 (s, νCH), 2893
(m, νCH), 1449 (w, δCH), 1378 (w, δCH), 1256 (s, δSiC), 1245 (vs,
alkoxy groups could aid in the â-hydrogen elimination
reaction. Base-assisted reductive elimination has been
proposed for other transition metal alkoxide com-
plexes.22
Con clu sion
Primary, secondary, and tertiary alkanethiolate com-
plexes of osmium(VI) possessing bridging thiolate ligands
have been prepared and characterized. These neutral
complexes are air- and water-stable and unreactive
toward nucleophiles and electrophiles. While these are
coordinately unsaturated, 16-electron complexes, they
are unreactive toward neutral donor ligands.
Anionic tetrathiolate and tetraalkoxide complexes of
osmium(VI) have also been prepared. Thermolysis of
6 and 7 leads to distinctly different products. Ther-
molysis of 6 leads only to benzyl disulfide, probably via
a simple reductive elimination process. Complex 7,
however, produces benzaldehyde and benzyl alcohol
upon heating in what is the first example of â-hydrogen
elimination from an osmium alkoxide complex.
δ
SiC), 1114 (m, νOsN), 848 (vs, νSiC), 833 (vs, νSiC), 714 (m), 683
(m). 1H NMR (400 MHz, toluene-d8, 20 °C, 85% 1a and 15%
1b by integration, other integrals are relative for that iso-
mer): δ 3.23 (dq, 2 H, SCHaHb, 1a ), 2.97 (dq, 2 H, SCHaHb,
1a ), 2.92 (q, 4H, SCH2, 1b), 2.65 (d, 2 H, OsCHaHb, 1b), 2.61
(d, 2 H, OsCHaHb, 1a ), 2.52 (d, 2 H, OsCHaHb, 1a ), 2.45 (d, 2
H, OsCHaHb, 1b), 1.31 (br t, 6 H, OsSCH2CH3, 1b), 1.23 (br t,
6 H, OsSCH2CH3, 1a ), 0.20 (s, 18 H, SiCH3, 1a ), 0.13 (s, 18 H,
SiCH3, 1b). 13C{1H} NMR (100.6 MHz, toluene-d8, 20 °C): δ
25.4 (s, SCH2, 1a ), 23.6 (s, SCH2, 1b), 18.4 (s, OsCH2, 1b), 17.5
(s, OsCH2, 1a ), 8.51 (s, SCH2CH3, 1a ), 7.61 (s, SCH2CH3, 1b),
1.73 (s, SiCH3, 1a ), 1.55 (s, SiCH3, 1b ). Anal. Calcd for
C
10H27NOsSSi2: C, 27.31; H, 6.19; N, 3.19. Found: C, 27.57;
H, 6.33; N, 3.26.
Syn th esis of [Os(N)(CH2SiMe3)2(µ-SCMe3)]2, 2. LiSCMe3
(0.014 g, 0.15 mmol) was added to a solution of [Os(N)(CH2-
SiMe3)2Cl]2 (0.058 g, 0.07 mmol) in 30 mL of CH2Cl2, and the
mixture was stirred overnight. The reaction mixture was
filtered through Celite, and the solvent was removed from the
filtrate in vacuum to give a yellow-brown oil. This oil was
Exp er im en ta l Section
All reactions were done under N2 using standard air-
sensitive techniques on
a Schlenk line or in a Vacuum
Atmospheres drybox unless otherwise stated. Anhydrous
ether, THF, and hexane were distilled from Na/benzophenone.
Methylene chloride and CH3CN were distilled from CaH2.
(23) Griffith, W. P.; Pawson, D. J . Chem. Soc., Dalton Trans. 1973,
1315-1320.
(24) Marshman, R. W.; Shusta, J . M.; Wilson, S. R.; Shapley, P. A.
Organometallics 1991, 10, 1671-1676.
(22) (a) Dumez, D. D.; Mayer, J . M. Inorg. Chem. 1995, 34, 6396-
6401. (b) Kapteijn, G. M.; Grove, D. M.; Kooijman, H.; Smeets, W. J .
J .; Spek, A. L.; Vankoten, G. Inorg. Chem. 1996, 35, 526-533.

Osmium(VI) Thiolate Complexes
Organometallics, Vol. 15, No. 24, 1996 5095
extracted with hexane and filtered through Celite. The hexane
was removed from the filtrate in vacuum and the resulting
yellow-brown oil was redissolved in a few milliliters of ether.
Bright orange crystals were obtained by slow evaporation of
the ether. IR (KBr pellet, cm-1): 2946 (m, νCH), 2893 (m, νCH),
1457 (w, δCH), 1364 (w, δCH), 1256 (m, δSiC), 1245 (s, δSiC), 1142
(m), 1114 (m, νOsN), 850 (vs, νSiC), 831 (vs, νSiC), 720 (m), 681
(m). 1H NMR (300 MHz, CDCl3, 25 °C, 87% 2a and 13% 2b
by integration, other integrals are relative for that isomer): δ
2.98 (d, 2 H, J ) 10.1 Hz, OsCHaHb, 2b), 2.87 (d, 2 H, J )
10.5 Hz, OsCHaHb, 2a ), 2.63 (d, 2 H, J ) 10.0 Hz, OsCHaHb,
2b), 2.27 (d, 2 H, J ) 10.6 Hz, OsCHaHb, 2a ), 1.19 (s, 9 H,
CCH3, 2b), 1.68 (s, 9 H, CCH3, 2a ), 0.11 (s, 18 H, SiCH3, 2a ),
0.01 (s, 18 H, SiCH3, 2b). Anal. Calcd for C12H31NOsSSi2:
C, 30.81; H, 6.68; N, 2.99. Found: C, 30.80; H, 6.84; N, 2.98.
Syn th esis of [Os(N)(CH2SiMe3)2(µ-SCHMe2)]2, 3. LiS-
CHMe2 (0.010 g, 0.12 mmol) was added to a solution of
[Os(N)(CH2SiMe3)2Cl]2 (0.044 g, 0.053 mmol) in 15 mL of
CH2Cl2, and the mixture was stirred overnight. The reaction
mixture was filtered through Celite, and the solvent was
removed in vacuum from the filtrate to yield a yellow-orange
oil. The oil was extracted with hexane and filtered through
Celite. The solvent was removed from the filtrate in vacuum
to give 0.042 g (0.046 mmol, 87%) of 3 as a yellow-orange oil.
IR (KBr pellet, cm-1): 2946 (s, νCH), 2892 (s, νCH), 1451 (m,
CHCHa3CHb3), 0.07 (s, 36 H, SiCH3). 13C{1H} NMR (100.6
MHz, CDCl3, 20 °C): δ 39.01 (s, SCH2CH), 31.24 (s, SCH2),
21.85 (s, OsCH2), 7.89 (s, SCH2CHMe2), 1.58 (s, SiCH3). Mass
spectrum (EI, 70 eV, m/z): 938 (M+).
A solution of KOCMe3 (0.011 g, 0.098 mmol) and HSCH2-
CHMe2 (10 µL, 0.092 mmol) in 10 mL of hexane was added to
a solution of [Os(N)(CH2SiMe3)2Cl]2 (0.018 g, 0.021 mmol) in
5 mL of hexane. The mixture was stirred for 12 h and filtered,
and the solvent was removed under vacuum. A yellow oil
consisting of a 1:1 mixture of 2 isomers of [Os(N)(CH2SiMe3)2(µ-
SCH2CHMe2)]2 was produced. 1H NMR (400 MHz, CDCl3, 20
°C, integrals are relative for each isomer): δ 3.31 (dd, J am
)
13.3 Hz, J ax ) 6.7 Hz, 2 H, SCHaHb, 4a ), 3.05 (dd, J am ) 13.3
Hz, J mx ) 7.9 Hz, 2 H, SCHaHb, 4a ), 2.79 (dd, J am ) 12.5 Hz,
J ax ) 6 Hz, 2 H, SCHaHb, 4b), 2.70 (dd, J am ) 12.5 Hz, J mx
)
6 Hz, 2 H, SCHaHb, 4b), 2.55 (d, J ) 10.3 Hz, 4 H, OsCHaHb,
4a ), 2.43 (d, J ) 10.5 Hz, 4 H, OsCHaHb, 4a ), 2.31 (m, 8 H,
OsCH2, 4b), 2.2 (m, 2 H + 2 H, SCH2CHMe2, 4a and 4b), 1.15
(d, J ) 4 Hz, 6 H, SCH2CHCHa3CHb3, 4a ), 1.13 (d, J ) 4 Hz,
6 H, SCH2CHCHa3CHb3, 4a ), 0.99 (d, J ) 4.9 Hz, 6 H, SCH2-
CHCHa3CHb3, 4b), 1.13 (d, J ) 4.9 Hz, 6 H, SCH2CHCHa3CHb
4b), 0.07 (s, 36 H, SiCH3, 4a ), -0.04 (s, 36 H, SiCH3, 4b).
,
3
Syn t h esis of [Os(N)(CH2SiMe3)2(µ-SCH2P h )]2, 5.
NaSCH2Ph (0.008 g, 0.055 mmol) was added to the stirring
orange solution of [Os(N)(CH2SiMe3)2Cl]2 (0.019 g, 0.023 mmol)
in 10 mL of THF. The reaction mixture was stirred overnight
(16 h). The solution changed from orange to an orange-gold
color over the course of the reaction. The solution was filtered
through Celite and the solvent removed from the filtrate under
vacuum to give a golden oil that was dried in vacuum. The
oil was extracted with hexane, and this extract was filtered
through Celite. The solvent was removed from the golden
filtrate under vacuum to give 0.022 g (0.022 mmol, 95%) of 5a
as a golden oil. Yellow crystals can be obtained by slow
evaporation from pentane (mp ) 150 °C, dec). Substituting a
mixture of KOCMe3 and HSCH2Ph for the NaSCH2Ph in the
reaction above leads to the production of an orange oil
containing 2 isomers in variable ratios. The 2 isomers can be
separated by fractional crystallization from pentane. IR (KBr
pellet, cm-1): 2946 (s, νCH), 2892 (m, νCH), 1257 (s, δSiC), 1244
(vs, δSiC), 1129 w, 1114 (m, νOsN), 1029 m, 969 m, 848 (vs, νSiC),
833 (vs, νSiC), 750 (m), 696 (m). 1H NMR (400 MHz, CDCl3,
22 °C, integrals are relative for each isomer): δ 7.5-7.0 (m,
SCH2C6H5), 4.75 (d, J ) 14.2 Hz, 2 H, SCHaHb, 5b), 4.48 (d, J
) 14.2 Hz, 2 H, SCHaHb, 5b), 4.10 (m, 4 H, SCH2, 5a ), 2.64 (d,
J ) 10.3 Hz, 4 H, OsCHaHb, 5b), 2.53 (d, J ) 10.5 Hz, 4 H,
OsCHaHb, 5b), 2.36 (m, 8 H, OsCH2, 5a ), 0.03 (s, SiCH3, 5a ),
- 0.01 (s, SiCH3, 5b). 13C{1H} NMR (100.6 MHz, CDCl3, 22
°C): δ 144.4 (s, SCH2C6H5, 5a ), 137.5 (s, SCH2C6H5, 5b), 128.9
(br s, SCH2C6H5, 5b), 128.9 (s, SCH2C6H5, 5a ), 128.7 (s,
SCH2C6H5, 5a ), 128.0 (s, SCH2C6H5, 5b), 126.1 (s, SCH2C6H5,
5a ), 36.4 (s, SCH2, 5b), 31.6 (s, SCH2, 5a ), 13.8 (s, OsCH2, 5b),
12.5 (s, OsCH2, 5a ), 1.60 (s, SiCH3, 5a ), 1.26 (s, SiCH3, 5b).
Mass spectrum (EI, 70 eV, m/z): 1006 (M+). λmax ) 236 nm.
Syn th esis of [P P h 4][Os(N)(SCH2P h )4], 6. [PPh4][Os(N)-
Cl4] (0.10 g, 0.15 mmol) was suspended in 25 mL of thf. Excess
NaSCH2Ph (0.098 g, 0.67 mmol) was added to the solution,
the flask was equipped with a water-cooled condenser, and the
solution was heated to reflux overnight (15 h). Over the course
of the reaction the solution turned deep yellow. Heating was
discontinued, and the reaction was cooled to room temperature.
The solution was filtered through Celite and the solvent
removed in vacuum from the filtrate to yield a yellow-gold oil.
Bright orange crystals (0.086 g, 0.083 mmol, 55%) were
obtained from CH2Cl2/hexane. IR (KBr pellet, cm-1): 3054 (w,
phenyl νCH), 3020 (w, phenyl νCH), 2912 (w, νCH), 1491 (s), 1436
(s , δCH), 1106 (vs, δPC), 1068 (s, phenyl δCH), 1027 (m, phenyl
δCH), 1365 (m, δCH), 1256 (s, δSiC), 1243 (vs, δSiC), 1152 m, 1117
(s, νOsN), 1049 m, 851 (vs, νSiC), 831 (vs, νSiC), 715 (s), 682 (s).
1H NMR (400 MHz, CDCl3, 20 °C, 78% 3a and 22% 3b by
integration, integrals are relative for each isomer): δ 4.14
(septet, J ) 6.8 Hz, 2H, SCH, 3a ), 3.81 (septet, J ) 7 Hz, 2H,
SCH, 3b), 1.71 (d, J ) 6.8 Hz, 12H, SCHCH3, 3a ), 1.54 (d, J
) 7 Hz, 12 H, SCHCH3, 3b), 0.09 (s, 36 H, SiCH3, 3b), 0.02 (s,
36 H, SiCH3, 3a ). 13C{1H} NMR (100.6 MHz, CDCl3, 20 °C):
δ 39.4 (s, SCH, 3a ), 38.8 (s, SCH, 3b), 26.7 (s, OsCH2, 3b),
26.7 (s, OsCH2, 3a ), 9.04 (s, SCHCH3, 3b), 7.45 (s, SCHCH3,
3a ), 1.46 (s, SiCH3, 3b), 1.41 (s, SiCH3, 3a ). Mass spectrum
(EI, 70 eV, m/z): 910 (M+).
The addition of an equimolar mixture of HSCHMe2 and
KOCMe3 to the [Os(N)(CH2SiMe3)2Cl]2 solution as above led
to the formation of an orange oil containing 3 isomers of
[Os(N)(CH2SiMe3)2(µ-SCHMe2)]2. The ratio of isomers was
1
determined by integration of the H NMR spectrum: 61% 3a ,
13% 3b, and 26% 3c. Homonuclear decoupling experiments
confirmed the proton assignments for the thiolate groups in
each isomer. 1H NMR (400 MHz, CDCl3, 20 °C, integrals are
relative for each isomer): δ 4.14 (septet, J ) 6.8 Hz, 2H, SCH,
3a ), 3.81 (septet, J ) 7 Hz, 2H, SCH, 3b), 3.65 (br septet, 2 H,
J ) 6 Hz, SCH, 3c), 1.71 (d, J ) 6.8 Hz, 12H, SCHCH3, 3a ),
1.54 (d, J ) 6.6 Hz, 12 H, SCHCH3, 3b), 1.35 (d, J ) 7 Hz,
6H, SCHMea, 3c), 1.27 (d, J ) 7 Hz, 6H, SCHMeb, 3c), 0.09 (s,
36 H, SiCH3, 3b), 0.02 (s, 36 H, SiCH3, 3a ), -0.04 (s, 36H,
SiMe3, 3c).
Syn th esis of [Os(N)(CH2SiMe3)2(µ-SCH2CHMe2)]2, 4.
LiSCH2CHMe2 (0.012 g, 0.12 mmol) was added to the stirring
orange solution of [Os(N)(CH2SiMe3)2Cl]2 (0.041 g, 0.05 mmol)
in 15 mL of CH2Cl2, and the reaction was stirred overnight.
The yellow solution was filtered through Celite and the solvent
removed in vacuum from the filtrate. The resulting yellow-
orange oil was extracted with hexane and filtered. The solvent
was removed from the filtrate in vacuum to give 0.022 g (0.023
mmol, 47%) of 4a as a yellow-orange oil. The addition of an
equimolar mixture of HSCH2CHMe2 and KOCMe3 to the
[Os(N)(CH2SiMe3)2Cl]2 solution as above also led to the forma-
tion of an orange oil containing only 4a . IR (KBr pellet, cm-1):
2952 (s, νCH), 2895 (m, νCH), 1464 (m, δCH), 1367 (m, δCH),
1258 (s, δSiC), 1245 (vs, δSiC), 1115 (s, νOsN), 1109 m, 850 (vs,
ν
SiC), 831 (vs, νSiC), 715 (m), 682 (m). 1H NMR (400 MHz,
CDCl3, 20 °C): δ 3.33 (dd, J am ) 13.3 Hz, J ax ) 6.7 Hz, 2 H,
SCHaHb), 3.07 (dd, J am ) 13.3 Hz, J mx ) 7.9 Hz, 2 H, SCHaHb),
2.57 (d, J ) 10.3 Hz, 4 H, OsCHaHb), 2.45 (d, J ) 10.5 Hz, 4
H, OsCHaHb), 2.14 (m, 2 H, SCH2CHMe2), 1.19 (d, J ) 4 Hz,
6 H, SCH2CHCHa3CHb3), 1.15 (d, J ) 4 Hz, 6 H, SCH2-
δCH), 996 (m, phenyl δCH), 768 (m), 723 (s), 700 (s), 689 (vs),
526 (vs). 1H NMR (400 MHz, CDCl3, 19 °C): δ 7.75 (m, 4 H,
p-PC6H5), 7.61 (m, 8 H, o- or m-PC6H5), 7.38 (m, 8 H, o- or
m-PC6H5), 7.26 (m, 8 H, SCH2C6H5), 7.06 (m, 8 H, SCH2C6H5),
6.98 (m, 4 H, SCH2C6H5), 4.24 (s, 8 H, SCH2). 13C{1H} NMR

5096 Organometallics, Vol. 15, No. 24, 1996
Shapley and Reinerth
(100.6 MHz, CDCl3, 19 °C): δ 144.2 (s, ipso-SCH2C6H5), 135.6
(d, J PC ) 3.1 Hz, p-PC6H5), 134.3 (d, J PC ) 10.7 Hz, m-PC6H5),
130.7 (d, J PC ) 13.0 Hz, o-PC6H5), 129.4 (s, o- or m-SCH2C6H5),
127.7 (s, o- or m-SCH2C6H5), 125.4 (s, p-SCH2C6H5), 117.2 (d,
J PC ) 90.0 Hz, ipso-PC6H5), 31.8 (s, SCH2). Anal. Calcd for
days of heating, none of the starting material was present by
1H NMR spectroscopy. Signals due to Me3SiCH2CH2SiMe3 and
Me4Si were present.
Th er m olysis of 5. A 0.005 g sample of 5a was sealed in a
5 mm NMR tube along with 0.75 mL of CDCl3. The solution
was heated to 115-120 °C. After 2 h, peaks for 5b were
visible. After 20 h, the original isomer (5a ) had been com-
pletely converted to 5b. Small amounts of PhCH2SSCH2Ph,
δ 3.58, and SiMe4, δ 0.0, were also present.
Th er m olysis of 6. A 0.005 g sample of 6 was dissolved in
0.75 mL of toluene-d8 and sealed in a 5 mm NMR tube. The
solution was heated to 70-90 °C. The 1H NMR spectrum of
this sample after 9 days showed signals due to benzyl disulfide.
Th er m olysis of 7. A 0.005 g sample of 7 was dissolved in
0.75 mL of toluene-d8 and sealed in a 5 mm NMR tube. The
solution was heated to 70-90 °C. The 1H NMR spectrum of
this sample after 12 days showed signals due to benzyl alcohol
and benzaldehyde. Gas chromatographic analysis of the
solution confirmed the presence of benzaldehyde and benzyl
alcohol in a 1:1 molar ratio.
C
52H48NOsPS4: C, 60.27; H, 4.67; N, 1.35. Found: C, 59.02;
H, 4.63; N, 1.33.
Syn th esis of [P P h 4][Os(N)(OCH2P h )4], 7. [PPh4][Os(N)-
Cl4] (0.040 g, 0.058 mmol) was suspended in 20 mL of THF.
Excess LiOCH2Ph (0.033 g, 0.29 mmol) was added, the flask
was fitted with a condenser, and the reaction was heated to
reflux overnight (11 h). The color of the solution changed from
the initial pale red color to a golden brown color. The solution
was filtered through Celite, and the solvent was removed in
vacuum to give a purple-brown oil. IR (KBr pellet, cm-1): 3054
(w, phenyl νCH), 3023 (w, phenyl νCH), 2846 (w, νCH), 1450 (m),
1438 (vs, δCH), 1107 (vs, δPC), 1044 (m, phenyl δCH), 1022 (m,
phenyl δCH), 995 (m, phenyl δCH), 725 (vs), 689 (vs), 527 (vs).
1H NMR (400 MHz, CDCl3, 19 °C): δ 8.0-6.9 (m, PC6H5,
OCH2C6H5), 4.64 (s, OCH2). 13C{1H} NMR (100.6 MHz, CDCl3,
19 °C): δ 145.9 (s, ipso-SCH2C6H5), 135.7 (d, J PC ) 2.3 Hz,
Th er m olysis of a Mixtu r e of 7 a n d 8. A solution of 0.055
g of 7 and 0.044 g of 8 in 0.75 mL of acetone-d6 was sealed in
a 5 mm NMR tube. The solution was heated to 97 °C for 6
days. The 1H NMR spectrum of this sample showed signals
due to PhCH2OH and PhCHO. There was no PhCHDOH
observed.
p-PC6H5), 134.2 (d, J PC ) 10.7 Hz, m-PC6H5), 130.7 (d, J PC
)
13.0 Hz, o-PC6H5), 127.4 (s, o- or m-SCH2C6H5), 127.3 (s, o- or
m-SCH2C6H5), 125.2 (s, p-SCH2C6H5), 117.2 (d, J PC ) 90.0 Hz,
ipso-PC6H5), 65.0 (s, SCH2).
Syn th esis of [N(n -Bu )4][Os(N)(OCD2P h )4], 8. Excess
PhCD2OH (0.5 g, 4.5 mmol) was added to a solution of [N(n-
Bu)4][Os(N)(OSiMe3)4] (0.050 g, 0.062 mmol) in 20 mL of thf.
After the solution was stirred for 1 h, the solvent and excess
PhCD2OH were removed under vacuum. The resulting orange
oil was dissolved in CH2Cl2. Toluene and pentane were added,
and the solution was cooled. Orange crystals of 8 were formed
(0.047 g, 0.053 mmol, 86%). Anal. Calcd for C44H56D8N2O4-
Os: C, 59.83; H (D), 8.22; N, 3.17. Found: C, 59.93; H (D),
7.54; N, 3.20.
Ack n ow led gm en t. We gratefully acknowledge the
financial support of the National Science Foundation
(Grant CHE 93-08450) and the National Institutes of
Health (Grant PHS 5 RO1 AI28851-02) in support of
this work. Spectra were obtained on NMR instruments
purchased through grants from the NIH and the NSF
(NIH PHS 1532135, NIH 1531957, and NSF CHE 85-
14500). The 70-VSE mass spectrometer was purchased
in part with a grant from the Division of Research
Resources, National Institutes of Health (RR 04648).
Th er m olysis of 1. A sample of 1 (0.005 g, 0.006 mmol) in
0.75 mL of toluene-d8 was heated at 115-120 °C in a sealed
1
NMR tube. The H NMR spectrum of this sample after 62.5
h of heating showed additional peaks between 0.0 and 0.2 ppm,
but otherwise the spectrum was largely unchanged. After 6
OM960491P