Reaction between the thiocarbonyl complex, Os(CS)(CO)(PPh3)3, and propyne: Crystal structure of a new sulfur-substituted osmabenzene

Article abstract of DOI:10.1016/S0022-328X(00)00717-8

Reaction between Os(CS)(CO)(PPh₃)₃ and propyne gives a complex mixture of products from which can be isolated the simple oxidative addition product Os(C?CMe)H(CS)(CO)(PPh₃)₂ (1) and the osmabenzene Os(η²-C[S]CMeCHCHCMe)(CO)(PPh₃)₂ (2), where the two propyne molecules in the osmabenzene ring have linked tail-to-tail. Treatment of 1 with HCl gives, as the ultimate product, the propenylthioacyl complex, Os(η²-C[S]CH=CHMe)Cl(CO)(PPh₃)₂ (3). The crystal structures of compounds 1-3 have been determined.

Full text of DOI:10.1016/S0022-328X(00)00717-8

Journal of Organometallic Chemistry 623 (2001) 109–115
www.elsevier.nl/locate/jorganchem
Reaction between the thiocarbonyl complex, Os(CS)(CO)(PPh3)3,
and propyne: crystal structure of a new sulfur-substituted
osmabenzene
Clifton E.F. Rickard, Warren R. Roper* 1, Scott D. Woodgate, L. James Wright* 2
Department of Chemistry, The Uni6ersity of Auckland, Pri6ate Bag 92019, Auckland, New Zealand
Received 7 July 2000; accepted 20 September 2000
Abstract
Reaction between Os(CS)(CO)(PPh3)3 and propyne gives a complex mixture of products from which can be isolated the simple
¸¹¹¹¹¹¹¹¹¹¹¹¹º
oxidative addition product Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1) and the osmabenzene Os(h2-C[S]CMeCHCHCMe)(CO)(PPh3)2 (2),
where the two propyne molecules in the osmabenzene ring have linked tail-to-tail. Treatment of 1 with HCl gives, as the ultimate
product, the propenylthioacyl complex, Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2 (3). The crystal structures of compounds 1–3 have
been determined. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Hydride complex; Osmabenzene; Osmium; Propynyl complex
1. Introduction
(3) and all three new compounds have been character-
ised by crystal structure determinations.
The first metallabenzenes were prepared by reaction
between Os(CS)(CO)(PPh3)3 [1] and ethyne [2]. Interest
continues in this remarkable class of compounds with
the development of alternative synthetic routes [3] and
the recent demonstration that the osmabenzene com-
pounds exhibit the defining chemical characteristic of
‘aromatic’ systems in that they undergo the electrophilic
aromatic substitution reactions of nitration and halo-
genation [4]. We have already reported that reaction
between Os(CS)(CO)(PPh3)3 and diphenylacetylene pro-
duces osmacyclobutadiene complexes [5]. In this paper
we further extend the original synthetic route by explor-
ing the reaction between Os(CS)(CO)(PPh3)3 and
propyne. A new 3,6-dimethyl-substituted osmabenzene
has been characterised, albeit in low yield, along with
the simple propynyl oxidative addition product,
Os(CꢀCMe)H(CS)(CO)(PPh3)2. Further reaction of this
propynyl complex with HCl produced the propenylth-
ioacyl complex, Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2
2. Results and discussion
2.1. Preparation and spectroscopic characterisation of
Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1) and
¸¹¹¹¹¹¹¹¹¹¹¹¹¹º
Os(p2-C[S]CMeCHCHCMe)(CO)(PPh3)2 (2) from
reaction between Os(CS)(CO)(PPh3)3 and propyne
Propyne was passed through
a
solution of
Os(CS)(CO)(PPh3)3 in benzene giving ultimately a dark
red–brown solution. From this was isolated a crude
solid showing at least three w(CO) bands in the IR
spectrum, suggesting that a number of products had
been formed. To separate these complexes the mixture
was subjected to column chromatography on silica gel.
Two new osmium complexes were isolated,
Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1) (in 23% yield) and
¸¹¹¹¹¹¹¹¹¹¹¹¹¹º
Os(h2-C[S]CMeCHCHCMe)(CO)(PPh3)2 (2) (in 8%
yield) (see Scheme 1). Complex 1 clearly arises from
simple oxidative addition of propyne to Os(CS)-
(CO)(PPh3)3. The IR spectrum of 1, which is the major
product and pink in colour, reveals a very high w(CO)
1 *Corresponding author. Tel.: +64-9-373 7999 ext. 8320; fax:
+64-9-373 7422; w.roper@auckland.ac.nz
2 *Corresponding author.
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00717-8

110
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
at 2009 cm−1, a feature previously observed in mixed
carbonyl, thiocarbonyl osmium(II) complexes [6]. The
21.91 ppm for C3% and at 47.65 ppm for C6%. The
resonances for the ring carbon atoms, C4 and C5, are
observed at 147.98 ppm and 129.22 ppm respectively.
The quaternary carbon resonances appear at
119.89 ppm for C3 (singlet), and as triplets at
257.43 ppm (2JCP=9.1 Hz) for C2 and 220.07 ppm
(2JCP=6.2 Hz) for C6. The carbonyl resonance is ob-
served at 203.06 ppm (2JCP=11.3 Hz). It is noteworthy
that the chemical shifts for C3, C4, and C5 in the
13C-NMR spectrum all fall within the region expected
for ‘aromatic’ carbon atoms.
The ring position of the methyl groups in the isolated
complex indicate that the two propyne units have
linked together in a tail-to-tail manner, i.e. the new
CꢂC bond has been formed by linkage of the two CH
termini. A possible route for the formation of this
metallabenzene could be through initial combination of
coordinated propyne with the CS ligand to form a
four-membered metallacyclic ring, followed by addition
of a second molecule of propyne with ring expansion
from four to six. There is precedent for the formation
of a four-membered ring complex from a coordinated
di-p-tolylacetylene and a CS ligand [5]. We have no
further evidence relating to the mechanism of this reac-
tion. In view of the fact that 2 is formed in such low
yield, and that we cannot exclude the possibility that
other isomers were also formed but not isolated, further
speculation about the mechanism based upon the ob-
served regiochemistry for 2 is unwarranted.
1
hydride resonance in the H-NMR spectrum of 1 ap-
pears as a high-field triplet at −8.61 ppm (2JHP
=
21.2 Hz) with coupling to two equivalent phosphorus
nuclei. The protons of the methyl group are also ob-
served as a triplet at 1.36 ppm (5JHP=2.5 Hz), from
long-range coupling to phosphorus. Other spectro-
scopic data are presented in the Section 4 for all the
new compounds.
Complex 2, the second product isolated from the
chromatography described above, was a dark-brown
crystalline solid that proved to be the 3,6-dimethyl-sub-
¸¹¹¹¹¹¹¹¹¹¹¹¹º
stituted osmabenzene, Os(h2-C[S]CMeCHCHCMe)-
(CO)(PPh3)2. The IR spectrum of this complex has a
w(CO) absorption at 1888 cm−1, a position close to
that observed for the parent, unsubstituted osmaben-
¸¹¹¹¹¹¹¹¹¹¹¹¹º
zene,
Os(h2-C[S]CHCHCHCH)(CO)(PPh3)2
at
1890 cm−1 [2]. The NMR spectroscopic characterisa-
tion of this complex involved acquiring H, 13C, as well
1
as 13C–1H-HMQC and 13C–1H-HMBC spectra. The
spectroscopic data are all consistent with the formula-
tion as a metallabenzene with methyl groups on C3 and
C6 only (see Fig. 2 for the metallabenzene ring atom
numbering scheme). The carbon and hydrogen atoms
of the methyl groups are labeled C3% and H3% for the
methyl group attached to C3, and C6% and H6% for the
1
methyl group attached to C6. The H-NMR spectrum
shows a singlet resonance at 1.64 ppm with an integral
of three protons that is assigned to H3%. A similar
resonance at 2.23 ppm is assigned to H6%. These assign-
ments were made by examination of the 13C–1H-
HMQC and 13C–1H-HMBC spectra and by the
chemical shift positions for H3% and H6%. The H6%
resonance will be downfield from the H3% resonance
because it is attached to C6, which is in turn bonded
directly to the osmium, whereas H3% is more remote
from the metal. The ring protons are both observed as
2.2. Preparation and spectroscopic characterisation of
Os(p2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2 (3)
Treatment of 1 with HCl results in the rapid forma-
tion of the dark-red coloured dihapto-propenylthioacyl
complex, Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2 (3).
The IR spectrum of this complex shows a w(CO) at
1901 cm−1 but no band appropriate for a terminal CS
1
ligand. The H-NMR spectrum of 3 shows a doublet at
doublets, coupling to each other at 6.65 ppm (3JHH
=
0.85 ppm (3JHH=6.8 Hz) (assigned to the protons of
8.1 Hz) for H5, and 7.59 ppm (3JHH=8.0 Hz) for H4.
the terminal methyl group), a doublet of quartets at
The 13C-NMR spectrum shows resonances at
3
6.08 ppm (3JHH=14.9 Hz, JHH=6.9 Hz) (assigned to
the proton on the carbon atom of the double bond that
bears the methyl group), and a second doublet at
5.85 ppm (3JHH=15.0 Hz) (assigned to the proton on
the other carbon atom of the double bond). The large
value of the coupling between the vicinal protons on
the double bond suggests a trans orientation for these
protons about the double bond, and this arrangement
has been confirmed by the X-ray crystal structure deter-
mination described in Section 2.3.
A plausible mechanism for this reaction is depicted in
Scheme 2. Although no definitive evidence for the
proposed intermediate vinylidene ligand has been ob-
tained, there is ample precedent for the formation of
vinylidene ligands through protonation of the b-carbon
Scheme 1. Synthesis of the new 3,6-dimethyl-substituted osmaben-
¸¹¹¹¹¹¹¹¹¹¹¹¹º
zene, Os(h2-C[S]CMeCHCHCMe)(CO)(PPh3)2 (2).

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
111
plexes Os(o-halophenyl)Cl(CS)(CO)(PPh3)2 require
heating to 70–80°C for some hours [8].
2.3. Crystallographic studies of 1, 2, and 3
The molecular geometries of 1, 2, and 3 derived from
X-ray crystallographic studies (see Table 1) are depicted
in Figs. 1–3 respectively, and selected bond lengths and
angles are presented in Tables 2–4 respectively. All
three complexes have approximately octahedral coordi-
nation geometry with mutually trans triphenylphos-
phine ligands. Complex
1 crystallises with two
independent molecules in the unit cell, both having cis
carbonyl and thiocarbonyl ligands with the propynyl
ligand trans to carbonyl. The hydride position was not
located, but its position can be inferred from the open
coordination site. The OsꢂC distances for the carbonyl
and thiocarbonyl ligands are not significantly different.
The coordinated propynyl ligand is approximately lin-
ear with the angle C(4ꢂC(3)ꢂOs(1) being 170.0(4)°, and
the angle C(3)ꢂC(4)ꢂC(5) being 175.7(5)°. The distance
Scheme 2. Conversion of the propynyl, thiocarbonyl complex,
Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1), to the propenylthioacyl complex,
Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2 (3).
atoms of alkynyl ligands [7]. The hydrido, vinylidene
intermediate then rearranges to a propenyl ligand,
which in turn migrates onto the thiocarbonyl ligand.
The migratory aptitude of the propenyl ligand is clearly
greater than that of o-halophenyl ligands, since we have
recently described that migration reactions of the com-
,
C(3)−C(4), 1.188(6) A, is appropriate for a CꢀC bond.
The structure of complex 2 is very similar to
that of the parent, unsubstituted osmabenzene,
Table 1
Data collection and processing parameters
1
2
3
Formula
Molecular weight
Temperature (K)
C41H33OOsP2S
825.87
203
C44H38OOsP2S
866.94
203
C41H35ClOOsP2S
863.34
203
,
Wavelength (A)
Crystal system
Space group
0.710 73
Triclinic
0.710 73
Orthorhombic
P212121
11.0376(2)
12.1891(3)
28.4102(7)
0.710 73
Orthorhombic
Abm2
9.1890(18)
24.608(5)
16.032(3)
(
P1
,
a (A)
10.2376(1)
16.0348(2)
22.1572(3)
101.180(1)
99.132(1)
96.918(1)
3479.84(7)
4
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3
,
V (A )
Z
3822.26(15)
4
1.507
1728
3.507
3625.2(12)
4
1.582
1712
dcalc (g cm−3
F(000)
)
1.576
1636
3.85
v (mm−1
)
3.769
Crystal size (mm)
2q (min–max) (°)
h,k,l range
0.54×0.18×0.13
0.95–28.24
0.24×0.07×0.06
1.43–28.19
0.22×0.085×0.05
1.66–28.21
−135h512, −205k520, 05l529 −145h514, 05k515, 05l537 −125h511, 05k532, 05l517
Reflections collected
Independent reflections, Rint
A (min, max)
28 418
23 873
8558, 0.0372
10 925
3487, 0.0463
15 576, 0.0235
0.230, 0.635
0.486, 0.817
0.491, 0.834
Function minimised
Goodness of fit on F2
R (observed data)a
R (all data)
Sw(F2o−F2c)2
Sw(F2o−F2c)2
Sw(F2o−F2c)2
1.109
1.010
1.071
R1=0.0357, wR2=0.0762
R1=0.0494, wR2=0.0832
+2.35, −1.44
R1=0.0320, wR2=0.0477
R1=0.0441, wR2=0.0510
+1.34, −0.77
R1=0.0438, wR2=0.0956
R1=0.0585, wR2=0.1029
+1.33, −1.35
−3
,
Diff. map (min, max) (e A
)
a R=SꢀFoꢁ−ꢁFcꢀ/SꢁFoꢁ; wR2={S[w(F2o−Fc2)2]/S[w(F2o)2]}1/2; w=1.0/[|2(F2o)+aP2+bP], P=(Fo2+2F2c)/3.

112
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
The molecular structure of complex 3 confirms the
presence of a dihapto-thioacyl ligand and, in general,
terms the ligand arrangements are closely similar to
those found for the related complexes Os(h2-
C[S]C6H4X-2)Cl(CO)(PPh3)2 (X=Cl or Br) [8]. In the
propenyl group the arrangement about the double bond
between C(3) and C(4) is trans and the C(3)ꢂC(4)
,
distance is 1.32(2) A, appropriate for a double bond.
3. Conclusions
A
new
dimethyl-substituted
osmabenzene,
¸¹¹¹¹¹¹¹¹¹¹¹¹¹º
Os(h2-C[S]CMeCHCHCMe)(CO)(PPh3)2, has been pre-
pared in low yield from reaction between
Os(CS)(CO)(PPh3)3 and propyne, showing that there is
some generality associated with this synthetic route.
Crystal structure determination reveals the positions of
methyl substitution and indicates that the presence of
these substituents does not perturb the ‘aromatic’ na-
ture of the ring, since ring planarity, equivalence of
OsꢂC distances, and ring CꢂC distances appropriate for
an aromatic system are all observed. A major by-
product of the synthesis proves to be the oxidative
addition product, Os(CꢀCMe)H(CS)(CO)(PPh3)2. This
is protonated by HCl to an intermediate propenylyli-
dene complex which rearranges via two migration pro-
cesses to the dihapto-propenylthioacyl complex,
Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2. Structure deter-
mination of this complex confirms a trans arrangement
about the double bond of the propenyl group.
Fig. 1. Molecular geometry of Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1).
¸¹¹¹¹¹¹¹¹¹¹¹¹º
Fig. 2. Molecular geometry of Os(h2-C[S]CMeCHCHCMe)(CO)-
(PPh3)2 (2).
¸¹¹¹¹¹¹¹¹¹¹¹º
Os(h2C[S]CHCHCHCH)(CO)(PPh3)2 [2]. The two
OsꢂC distances within the osmabenzene ring are almost
,
identical at 2.022(5) and 2.027(4) A. Furthermore, the
carbon–carbon bond lengths around the ring are
closely similar: C(2)ꢂC(3), 1.365(6); C(3)ꢂC(4), 1.400(7);
,
C(4)ꢂC(5), 1.385(7); C(5)ꢂC(6), 1.415(6) A. These val-
ues are typical for aromatic CꢂC distances and, to-
gether with the identical OsꢂC distances, point to
effective electron delocalisation around the ring. The
six-membered ring is almost perfectly planar, with only
very small deviations from the RMS plane of best fit
through the six ring atoms (Os, 0.014; C(2), −0.025;
Fig. 3. Molecular geometry of Os(h2-C[S]CHꢁCHMe)Cl(CO)(PPh3)2
(3).
,
C(3), 0.012; C(4), 0.014; C(5), −0.016; C(6), 0.001 A)
being observed.

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
113
400.1 MHz (1H) and 100.6 MHz (13C). Resonances are
quoted in parts per million and H-NMR spectra refer-
Table 2
Selected bond lengths (A) and angles (°) for 1
,
1
enced to either tetramethylsilane (0.00 ppm) or the pro-
teo-impurity in the solvent (7.25 ppm for CHCl3).
13C-NMR spectra were referenced to CDCl3
(77.00 ppm). Mass spectra were recorded using the fast
atom bombardment technique with a Varian VG 70-SE
mass spectrometer. Elemental analyses were obtained
from the Microanalytical Laboratory, University of
Otago.
Os(1)ꢂC(2)
Os(1)ꢂC(1)
Os(1)ꢂC(3)
Os(1)ꢂP(1)
Os(1)ꢂP(2)
S(1)ꢂC(2)
O(1)ꢂC(1)
C(3)ꢂC(4)
C(4)ꢂC(5)
Os(2)ꢂC(6)
Os(2)ꢂC(7)
Os(2)ꢂC(8)
Os(2)ꢂP(3)
Os(2)ꢂP(4)
S(2)ꢂC(7)
O(2)ꢂC(6)
C(8)ꢂC(9)
C(9)ꢂC(10)
1.894(5)
1.917(5)
2.088(4)
2.3672(11)
2.3849(11)
1.563(5)
1.150(6)
1.188(6)
1.489(7)
1.889(5)
1.908(5)
2.097(4)
2.3661(11)
2.3778(11)
1.559(5)
1.164(6)
1.206(6)
1.474(7)
4.2. Preparation of Os(CꢀCMe)H(CS)(CO)(PPh3)2 (1)
A 100 ml round-bottomed flask was fitted with a
reflux condenser, and dry, deoxygenated benzene
(50 ml) was added. Propyne gas was bubbled through
the benzene for 5 min; the stream of gas was stopped
temporarily,
and
Os(CO)(CS)(PPh3)3
(1.00 g,
C(2)ꢂOs(1)ꢂC(1)
C(2)ꢂOs(1)ꢂC(3)
C(1)ꢂOs(1)ꢂC(3)
C(2)ꢂOs(1)ꢂP(1)
C(1)ꢂOs(1)ꢂP(1)
C(3)ꢂOs(1)ꢂP(1)
C(2)ꢂOs(1)ꢂP(2)
C(1)ꢂOs(1)ꢂP(2)
C(3)ꢂOs(1)ꢂP(2)
P(1)ꢂOs(1)ꢂP(2)
C(4)ꢂC(3)ꢂOs(1)
C(3)ꢂC(4)ꢂC(5)
C(6)ꢂOs(2)ꢂC(7)
C(6)ꢂOs(2)ꢂC(8)
C(7)ꢂOs(2)ꢂC(8)
C(6)ꢂOs(2)ꢂP(3)
C(7)ꢂOs(2)ꢂP(3)
C(8)ꢂOs(2)ꢂP(3)
C(6)ꢂOs(2)ꢂP(4)
C(7)ꢂOs(2)ꢂP(4)
C(8)ꢂOs(2)ꢂP(4)
P(3)ꢂOs(2)ꢂP(4)
C(9)ꢂC(8)ꢂOs(2)
C(8)ꢂC(9)ꢂC(10)
97.6(2)
97.72(19)
164.0(2)
92.46(13)
91.84(15)
82.77(12)
95.31(13)
90.85(15)
92.45(12)
171.37(4)
170.0(4)
175.7(5)
94.4(2)
168.4(2)
96.88(19)
91.86(15)
93.35(14)
85.09(12)
90.11(15)
95.29(14)
91.24(12)
170.96(4)
174.9(4)
178.1(5)
0.953 mmol) was added. The mixture was heated to
40°C for 10 min with a constant flow of propyne bub-
bling through the solution. During this period the
Table 3
,
Selected bond lengths (A) and angles (°) for 2
OsꢂC(1)
OsꢂC(6)
OsꢂC(2)
OsꢂP(1)
OsꢂP(2)
OsꢂS
1.908(4)
2.022(5)
2.027(4)
2.3732(10)
2.3816(11)
2.4990(12)
1.689(6)
1.155(4)
1.365(6)
1.400(7)
1.520(6)
1.385(7)
1.415(6)
1.516(6)
SꢂC(2)
O(1)ꢂC(1)
C(2)ꢂC(3)
C(3)ꢂC(4)
C(3)ꢂC(7)
C(4)ꢂC(5)
C(5)ꢂC(6)
C(6)ꢂC(8)
C(1)ꢂOsꢂC(6)
C(1)ꢂOsꢂC(2)
C(6)ꢂOsꢂC(2)
C(1)ꢂOsꢂP(1)
C(6)ꢂOsꢂP(1)
C(2)ꢂOsꢂP(1)
C(1)ꢂOsꢂP(2)
C(6)ꢂOsꢂP(2)
C(2)ꢂOsꢂP(2)
P(1)ꢂOsꢂP(2)
C(1)ꢂOsꢂS
98.8(2)
173.8(2)
87.5(2)
86.59(12)
93.39(12)
92.99(11)
89.31(13)
94.95(12)
90.23(11)
171.19(4)
131.53(15)
129.68(15)
42.23(16)
89.22(4)
87.65(4)
53.77(14)
138.4(4)
137.5(4)
84.0(2)
4. Experimental
4.1. General procedures and instruments
Standard laboratory procedures were followed, as
have been described previously [9]. The compound
Os(CS)(CO)(PPh3)3 [1] was prepared according to the
literature method.
C(6)ꢂOsꢂS
C(2)ꢂOsꢂS
P(1)ꢂOsꢂS
P(2)ꢂOsꢂS
Infrared spectra (4000–400 cm−1) were recorded as
Nujol mulls between KBr plates on a Perkin Elmer
Paragon 1000 spectrometer. NMR spectra were ob-
C(2)ꢂSꢂOs
C(3)ꢂC(2)ꢂS
C(3)ꢂC(2)ꢂOs
SꢂC(2)ꢂOs
1
tained on a Bruker DRX 400 spectrometer at 25°C. H-
and 13C-NMR spectra were obtained operating at

114
C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
Table 4
4.3. Preparation of
Os(p2-C[S]CMeCHCHCMe)(CO)(PPh3)2 (2)
¸¹¹¹¹¹¹¹¹¹¹¹¹¹º
,
Selected bond lengths (A) and angles (°) for 3
OsꢂC(1)
OsꢂC(2)
OsꢂP
OsꢂCl
OsꢂS
1.885(16)
1.927(13)
2.3808(16)
2.493(3)
2.542(3)
1.656(16)
1.072(18)
1.44(2)
Material from the brown band collected in the syn-
thesis of complex 1 described in Section 4.2 was dis-
solved in the minimum amount of dichloromethane (ca
1 ml) and placed on a silica gel column (2.5 cm×
1.5 cm). The fast-moving reddish-brown band was
eluted using hexane:dichloromethane (1:3). Ethanol
(20 ml) was added to the eluate and the dichloro-
methane was removed using a rotary evaporator. The
resulting product was recrystallised from dichloro-
methane:ethanol (25 ml:10 ml) to yield pure complex 2
as dark brown crystals (7 mg, 8%). m/z 868.1705;
C44H38OOsP2S requires 868.1734. Anal. Found: C,
56.77; H, 4.43. Calc. for C44H38OOsP2S·CH2Cl2: C,
56.77; H, 4.24%.
SꢂC(2)
O(1)ꢂC(1)
C(2)ꢂC(3)
C(3)ꢂC(4)
C(4)ꢂC(5)
1.32(2)
1.49(3)
C(1)ꢂOsꢂC(2)
C(1)ꢂOsꢂP
C(2)ꢂOsꢂP
PꢂOsꢂPc1
C(1)ꢂOsꢂCl
C(2)ꢂOsꢂCl
PꢂOsꢂCl
C(1)ꢂOsꢂS
C(2)ꢂOsꢂS
PꢂOsꢂS
103.4(7)
89.99(12)
90.80(11)
178.4(3)
107.2(5)
149.3(4)
89.22(17)
144.1(5)
40.7(5)
90.49(4)
108.7(2)
49.3(5)
179.8(17)
128.8(10)
141.1(11)
90.1(7)
1
IR (cm−1): 1888 w(CO); 1378, 1250, 1235. H-NMR
(CDCl3; l): 1.64 (s, 3H, Me-3); 2.23 (s, 3H, Me-6); 6.65
ClꢂOsꢂS
3
3
(d, H-5, JHH=8.1 Hz); 7.59 (d, H-4, JHH=8.0 Hz);
7.20–7.40 (m, PPh3). 13C-NMR (CDCl3; l): 21.91 (s,
Me-3); 47.65 (s, Me-6); 119.89 (s, C-3); 129.22 (s, C-5);
C(2)ꢂSꢂOs
O(1)ꢂC(1)ꢂOs
C(3)ꢂC(2)ꢂS
C(3)ꢂC(2)ꢂOs
SꢂC(4)ꢂOs
C(4)ꢂC(3)ꢂC(2)
C(3)ꢂC(4)ꢂC(5)
2
147.98 (s, C-4); 203.06 (t, CO, JCP=11.3 Hz); 220.07
2
2
(t, C-6, JCP=6.2 Hz); 257.43 (t, C-2, JCP=9.1 Hz);
127.00 (t%, PPh3 ortho, 2,4JCP=10.1 Hz); 129.40 (s,
PPh3, para); 132.80 (t%, PPh3 ipso 1,3JCP=51.3 Hz);
134.44 (t%, PPh3 meta, 3,5JCP=10.1 Hz).
122.7(15)
123.9(17)
tan-coloured starting material dissolved and a black
solution formed. The solution was then heated under
reflux for a further 30 min, during which time a dark
red–brown colour appeared. The benzene was removed
in vacuo and the mixture was dissolved in the minimum
amount of dichloromethane (ca 1 ml). The solution was
then placed on a silica gel column (2.5 cm×1.5 cm)
and eluted using dichloromethane as the eluant. The
fast-running dark brown band was collected and from
this solution complex 2 was isolated (see Section 4.3). A
slower-moving light pink band was also collected from
the column, whereas a large black band did not elute
with dichloromethane. Addition of ethanol to the pink
eluate, followed by removal of the dichloromethane,
afforded pure complex 1 as bronze-coloured crystals
(181 mg, 23%). m/z 829; C41H34OOsP2S requires 829.
Anal. Found: C, 59.44; H, 4.24. Calc. for
C41H34OOsP2S: C, 59.55; H, 4.14%. IR (cm−1): 2009
4.4. Preparation of
Os(p2-C[S]CH=CHMe)Cl(CO)(PPh3)2 (3)
Os(CꢀCMe)H(CS)(CO)(PPh3)2 (100 mg, 0.119 mmol)
was dissolved in dichloromethane (20 ml) and concen-
trated aqueous HCl (two drops) was added. The colour
changed instantly from pink to dark red. Ethanol
(10 ml) was added to the reaction mixture and the
product was isolated after removal of the
dichloromethane using a rotary evaporator. The dark-
red product was recrystallised from dichloromethane:
ethanol (25 ml:10 ml) to yield pure complex 3 as dark-
red crystals (96 mg, 93%). m/z 864.1154 C41H35-
ClOOsP2S requires 864.1127. Anal. Found: C, 56.74; H,
4.01. Calc. for C41H35ClOOsP2S: C, 57.04; H, 4.09%.
IR (cm−1): 1901 w(CO); 1605, 1310, 1276, 1252, 871,
589. 1H-NMR (CDCl3; l): 0.85 (d, 3H, ꢁCHMe,
3JHH=6.8 Hz); 5.85 (d, 1H, ꢂCHꢁ, 3JHH=15.0 Hz);
6.08 (dq, 1H, ꢁCHMe, JHH=14.9 Hz, JHH=6.9 Hz);
7.36–7.88 (m, PPh3). 13C-NMR (CDCl3; l): 19.36 (s,
Me); 127.80 (t%, PPh3 ortho, 2,4JCP=10.1 Hz); 129.89 (s,
PPh3 para); 131.44 (t%, PPh3 ipso, 1,3JCP=51.2 Hz);
134.46 (t%, PPh3 meta, 3,5JCP=9.1 Hz); 140.11 (s,
ꢁCHMe); 146.38 (s, ꢂCHꢁ).
1
w(CO); 1259 w(CS); 720. H-NMR (CDCl3; l) −8.61
3
3
2
5
(t, 1H, OsH, JHP=21.2 Hz); 1.36 (t, 3H, CMe, JHP
=
2.5 Hz); 7.77–7.83 (m, PPh3). 13C-NMR (C6D6; l) (res-
onances between 127 and 128 ppm not observed
because of solvent) 6.34 (s, cMe)); 77.86 (s, ꢀCMe);
107.45 (s, OsꢂCꢀ); 129.74 (s, PPh3 para); 134.54 (t%, [9]
PPh3 meta, 3,5JCP=11.1 Hz).

C.E.F. Rickard et al. / Journal of Organometallic Chemistry 623 (2001) 109–115
115
4.5. X-ray crystal structure determinations for
complexes 1, 2, and 3
in-aid and through the award of a Doctoral Scholarship
to S.D.W. We are also very grateful to Dr Klaus
Hu¨bler, Universita¨t Stuttgart, for assistance with the
solution of the crystal structure of compound 3.
X-ray data collection for 1, 2, and 3 was on a Siemens
SMART diffractometer with a CCD area detector,
using graphite-monochromated Mo–Ka radiation (u=
,
0.710 73 A). Data were integrated and Lorentz and
polarisation correction applied using SAINT [10] soft-
ware. Semi-empirical absorption corrections were ap-
plied based on equivalent reflections using SADABS [11].
The structures were solved by Patterson and Fourier
methods and refined by full-matrix least squares on F2
using programs SHELXS [12] and SHELXL [13]. All non-
hydrogen atoms were refined anisotropically and hydro-
gen atoms were included in calculated positions and
refined with a riding model with thermal parameter 20%
greater than the Uiso of the carrier atom. Crystal data and
refinement details are given in Table 1.
References
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5. Supplementary material
[4] C.E.F. Rickard, W.R. Roper, S.D. Woodgate, L.J. Wright,
Angew. Chem. Int. Ed. Engl. 39 (2000) 750.
Crystallographic data (excluding structure factors) for
the structures reported have been deposited with the
Cambridge Crystallographic Data Centre as supplemen-
tary publication nos. 146361, 146362, 146363 for 1, 2,
and 3 respectively. Copies of this information can be
obtained free of charge from the Director, CCDC, 12
Union Road, Cambridge CB2 1EZ, UK (fax: +44-
1223-336033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
[5] G.P. Elliott, W.R. Roper, J. Organomet. Chem. 250 (1983) C5.
[6] G.R. Clark, K. Marsden, W.R. Roper, L.J. Wright, J. Am.
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[7] C. Elschenbroich, A. Salzer, Organometallics A Concise Intro-
duction, VCH, Weinheim, 1992.
[8] C.E.F. Rickard, W.R. Roper, S.D. Woodgate, L.J. Wright, J.
Organomet. Chem. in press.
[9] S.M. Maddock, C.E.F. Rickard, W.R. Roper, L.J. Wright,
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[10] SAINT, Area Detector Integration Software, Siemens Analytical
Instruments Inc., Madison, WI, USA, 1995.
[11] G.M. Sheldrick, SADABS, Program for Semi-Empirical Absorp-
tion Correction, University of Go¨ttingen, 1977.
[12] G.M. Sheldrick, SHELXS, Program for Crystal Structure Deter-
mination, University of Go¨ttingen, 1977.
Acknowledgements
We thank the University of Auckland Research Com-
mittee for partial support of this work through grants-
[13] G.M. Sheldrick, SADABS, Program for Crystal Structure Refine-
ment, University of Go¨ttingen, 1977.
.
.