Reactivity of osmium-rhodium mixed-metal cluster [Os3Rh(μ-H)3(CO)12] towards vinyl containing ligands

Article abstract of DOI:10.1016/S0022-328X(02)01721-7

Reaction of [Os₃Rh(μ-H)₃(CO)₁₂] (1) with an excess amount of vinylacetic acid gave two new clusters, [Os₂Rh₂(μ-CO)₂(η³-CH₂CHCH₂COO)₂(CO)₇

Full text of DOI:10.1016/S0022-328X(02)01721-7

Journal of Organometallic Chemistry 659 (2002) 151ꢀ158
/
www.elsevier.com/locate/jorganchem
Reactivity of osmiumꢀrhodium mixed-metal cluster [Os Rh(m-
/
3
H) (CO) ] towards vinyl containing ligands
3
12
Jasmine Po-Kwan Lau, Wing-Tak Wong *
Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
Received 13 June 2002; received in revised form 8 July 2002; accepted 8 July 2002
Abstract
6
Reaction of [Os
3
Rh(m-H)
3
(CO)12] (1) with an excess amount of vinylacetic acid gave two new clusters, [Os
3
Rh
5 2
(m-CO)(h -
C
H
6 5
CH )(CO)16] (2) and [Os
3
2
Rh
2
(m-CO)
2
(h -CH
2 2 2 7
CHCH COO) (CO) ] (3) in 20 and 40% yields, respectively. Treatment of
6
[
[
Os Rh(m-H) (CO) ] with vinylacetate in refluxing toluene afforded the complexes [Os Rh(m -CCH )(h -C H CH )(CO) ] (4) and
3
3
12
3
3
3
6
5
3
9
6
Os
5
Rh
2
(m-CO)(h -C
H
6 5
CH
3
)(CO)16] (2) in 40 and 20% yields, respectively. Thermolysis of [Os
3
Rh(m-H)
]. Treatment of 1-octene with [Os
(CO)12] led to the isomerization to give all isomers of octenes. All the new clusters have been fully characterized by both
3
(CO)12] in refluxing
6
toluene produced the known cluster compound, [Os
H)
3
Rh(m-H)
(h -C H
3 6 5
CH
3
)(CO)
9
3
Rh(m-
3
spectroscopic and crystallographic techniques. The isomerization has been examined by GCMS technique. # 2002 Elsevier Science
B.V. All rights reserved.
Keywords: Osmium; Rhodium; Crystal structure; Vinyl; Isomerization
1
. Introduction
[7]. It would be interesting to explore the possibility of
cluster aggregation and catalytic isomerization of al-
kenes based on the interaction of 1 with some vinyl
functionalities.
Heterometallic carbonyl clusters have caught consid-
erable attention because of their potential of new
catalytic and stoichiometric reactions [1]. Adding to
this is the recent advances in nanoscale materials that
using mixed-metal clusters as precursor [2,3]. We are
interested in the mixed-metal clusters of Os and Rh
combination due to the fact that metal exhibits sig-
nificant catalytic reactivity towards a number of chemi-
cal process while the osmium metal is well-known for its
2. Results and discussion
2.1. Synthesis, structure and spectroscopy
2.1.1. Reaction of [Os
vinylacetic acid
Rh(m-H) (CO)12] with
3
3
kinetic stability [4ꢀ
/
6]. This metal combination allows
Heating [Os Rh(m-H) (CO) ] (1) with an excess
the possibility of observing good reactivity and sufficient
thermodynamic stability of the cluster intermediates
occurred in the catalytic process. In this work, we report
the reactivity study of the mixed-metal clusters
3
3
12
amount of vinylacetic acid in refluxing toluene for 5 h
6
gave
[
[Os Rh (m-CO)(h -C H )(CO) ]
(2)
and
(3)
5
2
7
8
16
3
Os Rh (m-CO) (h -CH CHCH COO) (CO) ]
2
2
2
2
2
2
7
(Scheme 1). The spectroscopic data of 2 and 3 are listed
in Table 1. The IR spectrum of 2 indicates both terminal
[Os Rh(m-H) (CO) ] (1) towards a series of vinyl
containing ligands. Cluster 1 has been synthesized in
3
3
12
and bridging carbonyls are present. The mass spectrum
ꢃ
good yield (60%) from the unsaturated cluster [Os (m-
H) (CO) ] with [{Rh(CO) Cl} ] dimer, and some sub-
stitution reaction of CO ligands of 1 was also reported
3
exhibits a daughter peak at m/zꢁ
/
1697 [MꢂCO]
/
2
10
2
2
rather than a parent isotopic peak (expected m/zꢁ
/
1
725). This suggests that cluster 2 may easily undergo
1
fragmentation in the ionization process. The H-NMR
signals due to the protons of the phenyl ring are
* Corresponding author. Fax: ꢃ
E-mail address: wtwong@hkucc.hku.hk (W.-T. Wong).
/852-254-72933/285-71586
observed in the range of d 5.90ꢀ6.30 and the resonance
/
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 7 2 1 - 7

152
J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ
/158
Scheme 1.
for the methyl protons of the tolyl ligand occurs at d
.32. The molecular structure of 2 was established by X-
solution at ꢂ
/
20 8C. Fig. 1 shows the molecular
2
ray analysis on a black, air stable crystal that was
structure of 2 and the numbering scheme for the
resulting molecular configuration. The selected bond
parameters are given in Table 2. One half of a molecule
obtained by diffusion of n-hexane into a CH Cl
2
2
Table 1
Spectroscopic data for compounds 2ꢀ4
/
Cluster IR spectra n(CO) (cmꢂ1
a
)
Mass spectra
m/z)
b
1 c
H-NMR spectra d, J (Hz)
(
ꢃ
2
3
4
2191s, 2057s, 2041s, 2010m,
976s, 1931m, 1825m
2097w, 2056vs, 2024s, 1994s
Nujol)
2062s, 2020vs, 1987m, 1968m, 1045(1045)
933w
1698 [MꢂCO]
6.30 (dt, JHHꢁ7.7, 1H, Ph); 6.19 (dt, JHHꢁ5.7, 1H, Ph); 6.07 (d, JHHꢁ7.3, 1H, Ph);
1
5.93 (t, JHHꢁ7.6, 1H, Ph); 5.90 (d, JHHꢁ8.1, 1H, Ph); 2.32 (s, JHHꢁ6.2, 3H, CH
7.03(m, 1H, CH); 5.84 (dd, JHHꢁ15.5, 1.7 1H, CH); 1.90 (dd, JHHꢁ6.9, 1.7 3H, CH
3
)
1008 (1008)
3
)
(
6.50 (t, JHHꢁ5.3, 2H, Ph); 6.35 (d, JHHꢁ6.1, 2H, Ph); 6.17 (t, JHHꢁ6.0, 1H, Ph);
3.99 (s, JHHꢁ7.6, 3H, CH ); 2.14 (s, 3H, CH
1
3
3
)
a
b
c
Recorded in CH
Positive FAB-MS, calculated values in parentheses.
Recorded in CD Cl for 2, CDCl for 3 and 4.
2 2
Cl unless otherwise stated.
2
2
3

J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ
/158
153
6
Fig. 1. The molecular structure of [Os
5
Rh
2
(m-CO)(h -C
6
H
5
CH
3
)(CO)16] (2) with the atom numbering scheme.
was found to cap on the [Os(2)Ã
/
Os(3)Ã
/
Os(4)] triangular
6
Table 2
˚
face. The essentially planar tolyl ligand in 2 is in a h -
bonding mode and bonded to the Rh(2) atom. This
Selected bond distances (A) and angles (8) for cluster 2
Bond distances
6
unusual coordination of the h -tolyl ligand from the
Os(1)ÃOs(2)
Os(1)ÃRh(1)
Os(2)ÃOs(3)
Os(2)ÃOs(5)
Os(3)ÃOs(4)
Os(3)ÃRh(1)
Os(4)ÃOs(5)
Rh(1)ÃRh(2)
2.8095(8) Os(1)ÃOs(4)
2.821(2)
Os(1)ÃRh(2)
2.8516(9)
2.792(1)
2.8173(9)
2.772(1)
2.7320(8)
2.717(1)
2.847(1)
solvent has been reported [8,9]. The IR spectrum of 3
shows the presence of terminal carbonyls only and the
signal of the bridging carbonyl ligand may be too weak
to be observed. The mass spectrum shows a molecular
peak at m/z 1008, together with daughter ions due to the
2.8077(9) Os(2)ÃOs(4)
2.8659(9) Os(2)ÃRh(2)
2.8616(8) Os(3)ÃOs(5)
2.736(8)
Os(3)ÃRh(2)
2.8505(8) Os(4)ÃRh(1)
2.720(2)
1
sequential losses of terminal carbonyl ligand. The H-
NMR spectrum of 3 obtained showed features that are
not compatible with the structure observed in the solid-
state structure. The presence of two double doublets
with integral ratio of 1:3 at d 5.84 and 1.90 suggested the
possibility of isomerization of vinyl moieties to give a
terminal methyl substituent via a 1,3-hydrogen shift (see
Bond angles
Os(1)ÃRh(1)ÃOs(3)
Os(1)ÃRh(1)ÃRh(2)
Os(1)ÃRh(1)ÃOs(3)
Os(3)ÃRh(1)ÃRh(2)
Os(1)ÃRh(2)ÃOs(2)
Os(1)ÃRh(2)ÃRh(1)
Os(2)ÃRh(2)ÃRh(1)
91.27(4)
60.47(4)
62.84(3)
Os(1)ÃRh(1)ÃOs(4)
Os(3)ÃRh(1)ÃOs(4)
Os(1)ÃRh(1)ÃOs(2)
60.40(3)
61.03(3)
64.63(3)
90.66(5)
92.32(4)
61.53(3)
60.42(4)
59.73(4?) Os(4)ÃRh(1)ÃRh(2)
60.66(3)
61.56(4)
91.31(5)
Os(1)ÃRh(2)ÃOs(3)
Os(2)ÃRh(2)ÃOs(3)
Os(3)ÃRh(2)ÃRh(1)
Scheme 2). A similar process has been observed for
3
[
Mo{h -CH C(Ph)CH(Ph)}{P(OMe) }(h-C H )] [10].
2
3
5
5
Red crystals of 3 suitable for X-ray diffraction analysis
were grown from a saturated solution of n-hexane and
of CH Cl , as a solvent of crystallization, is found in the
2
2
asymmetric unit. The cluster consists of octahedral
metal core [Os(1), Os(2), Os(3), Os(4), Rh(1) and
CH
shown in Fig. 2 and bond distances and angles are listed
2
Cl
2
at ꢂ20 8C. The molecular structure of 3 is
/
Rh(2)] with a CO ligand bridged across the Rh(1)Ã
/
in Table 3. Cluster 3 contains four metal atoms in which
Rh(2)] arrange in a triangle
˚
Os(3) bond [2.736(1) A]. An additional Os atom, Os(5)
three of them [Os(1)Ã
/
Rh(1)Ã
/

154
J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ158
/
2.1.2. Reaction of [Os Rh(m-H) (CO) ] with
vinylacetate
3 3 12
A solution of [Os Rh(m-H) (CO) ] with an excess
3
3
12
amount of vinylacetate in refluxing toluene for 2 h led to
6
cluster 2 and [Os Rh(m -CCH )(h -C H CH )(CO) ]
3
3
3
6
5
3
9
(
4). Cluster 4 was characterized by various spectroscopic
methods (Table 1). The IR spectrum exhibits peaks of
terminal carbonyl ligand. The mass spectrum shows
molecular ion envelopes that agree with the formulae of
Scheme 2.
with two CO ligands bridged across each OsÃ
The Os(2) is bonded to Os(1) together via two support-
ing acetate group. The complex contains two
/Rh edge.
1
the compounds. The H-NMR spectrum contains the
phenyl proton resonance at d 6.17ꢀ6.50, a singlet for the
/
methyl proton of the tolyl ligand at d 3.99 and signal at
d 2.14 for the methyl proton of the methlidyne ligand.
In order to elucidate its molecular structure so as to find
out the coordination geometry of the ligands, X-ray
analysis was carried out on a black crystal of complex 4,
obtained by diffusion of n-hexane into a CH Cl
(
CH CHCH COO) groups, which are derived from the
2 2
deprotonation of the vinylacetic acid ligands. The two
CH CHCH COO) units bridge to the metal atoms
(
2
2
[Os(2)Ã
atom. Each of the two (CH CHCH COO) units, act as a
/
Rh(2), Os(2)Ã/Rh(1), respectively] via the oxygen
2
2
2
2
ꢂ
5
e
donor. Together with seven terminal and two
solution at ꢂ20 8C. The molecular structure and
/
bridging carbonyls make up the valence electron count
to 62, which is two electrons less than required by the
effective atomic number (EAN) rule. This type of
skeleton is not commonly observed and the established
selected bond parameters of complex 4 is shown in
Fig. 3 and Table 4, respectively. The three osmium
atoms and one rhodium atom define a distorted tetra-
6
hedron with a tolyl ligand bonding to it in a h -bonding
mode via the Rh(1) atom with a mean deviation of
5
1
2
example included [Ru(1-5-h -C H )(h (O), h (C,C)-
OCOCH CHÄ
CH )(PMe )] [11,12].
8
11
/
CH )(PMe )]
and
[Pd(OCOCH CÄ
/
˚
0.0217 A from the least-square plane. This type of
bonding mode has been observed in a closely related
2
2
3
2
2
3
3
Fig. 2. The molecular structure of [Os Rh
2
2
(m-CO)
2
2 2 2 7
(h -CH CHCH COO) (CO) ] (3) with the atom numbering scheme.

J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ
/158
155
Table 3
amount of 1-octene in n-heptane at different tempera-
tures (25, 60 and 100 8C) for 24 h have been investi-
gated. No new cluster compound was obtained as
evident from IR and TLC monitoring. Nevertheless,
the isomerization of 1-octene occurs at 60 and 100 8C as
shown by GCMS technique. At 100 8C, seven peaks
˚
Selected bond distances (A) and angles (8) for cluster 3
Bond distances
Os(1)ÃOs(2)
Os(1)ÃRh(2)
Os(2)Á Á ÁRh(1)
Os(2)ÃO(10)
Rh(1)ÃRh(2)
Rh(1)ÃC(12)
Rh(2)ÃO(12)
Rh(2)ÃC(17)
O(11)ÃC(10)
O(13)ÃC(14)
C(11)ÃC(12)
C(14)ÃC(15)
C(16)ÃC(17)
2.8692(8) Os(1)ÃRh(1)
2.824(1)
1.95(2)
3.540(1)
2.106(9)
2.086(10)
2.22(2)
2.20(2)
1.31(2)
1.33(2)
1.53(2)
1.36(2)
1.45(2)
2.831(1)
3.490(1)
2.112(9)
2.807(2)
2.18(1)
2.073(9)
2.20(2)
1.17(2)
1.21(2)
1.51(2)
1.50(2)
1.31(3)
Os(1)ÃC(4)
Os(2)Á Á ÁRh(2)
Os(2)ÃO(12)
Rh(1)ÃO(10)
Rh(1)ÃC(13)
Rh(2)ÃC(16)
O(10)ÃC(10)
O(12)ÃC(14)
C(10)ÃC(11)
C(12)ÃC(13)
C(15)ÃC(16)
were observed in the gas chromatogram, all with m/zꢁ
/
112, which correspond to the isomer of 1-octene:(E)-2-
octene, (Z)-2-octene, (E)-3-octene, (Z)-3-octene, (E)-4-
octene and (Z)-4-octene in various amounts. This
indicated that 1 could catalyze the isomerization of
alkenes. However, no optimization of the reaction was
performed at this stage of investigation.
Bond angles
3
. Experimental
Os(1)ÃOs(1)ÃRh(1)
Rh(1)ÃOs(1)ÃRh(2)
Os(1)ÃOs(2)ÃO(12)
Os(1)ÃRh(1)ÃRh(2)
Rh(2)ÃRh(1)ÃO(10)
Rh(2)ÃRh(1)ÃC(12)
O(10)ÃRh(1)ÃC(12)
Os(1)ÃRh(2)ÃRh(1)
Rh(1)ÃRh(2)ÃO(12)
Rh(1)ÃO(10)ÃC(10)
Rh(2)ÃO(12)ÃC(14)
C(11)ÃC(12)ÃC(13)
75.68(3)
59.51(4)
82.4(2)
60.36(4)
92.5(3)
134.4(5)
79.0(5)
60.13(4)
85.1(3)
Os(2)ÃOs(1)ÃRh(2)
Os(1)ÃOs(2)ÃO(10)
O(10)ÃOs(2)ÃO(12)
Os(1)ÃRh(1)ÃO(10)
Rh(2)ÃRh(1)ÃC(8)
Rh(2)ÃRh(1)ÃC(13)
O(10)ÃRh(1)ÃC(13)
Os(1)ÃRh(2)ÃO(12)
Os(2)ÃO(10)ÃRh(1)
76.73(3)
82.9(3)
80.5(4)
84.5(3)
92.0(6)
99.3(6)
86.9(5)
84.0(2)
112.6(4)
115.7(4)
113(1)
3.1. General procedures
All reactions and manipulations were carried out
under nitrogen using Schlenk techniques unless other-
wise stated. Glassware was pre-dried in an oven
(
Â120 8C) before used. Reactions were monitored by
/
119.4(10) Os(2)ÃO(12)ÃRh(2)
117.3(9)
124(1)
both IR spectroscopy and analytical thin-layer chroma-
tography (Merck Kieselgel 60 F254) and the products
were separated by thin-layer chromatography on plates
coated with silica (Merck Kieselgel 60 F254). Dichlor-
omethane (Ajax, AR) was distilled over calcium hy-
dride. n-Hexane (Ajax, AR) was purified by distillation
in the presence of sodium-benzophenone. All other
solvents were analytical grade and were used as received.
Before use, they were freed from oxygen by degassing
and saturating with nitrogen atmosphere.
C(10)ÃC(11)ÃC(12)
6
cluster [Os Rh(m-H) (h -C H CH )(CO) ] [8]. A methy-
3
3
6
5
3
9
lidyne unit is capped on the triangular face [Os(1)Ã
/
Os(2)Ã
/
Rh(1)] of the metal core. The vinyl group is
believed to coordinate to the metal core first and
followed by the rearrangement to give the ethylidyne
moiety via vinylidene and hydride formation [13ꢀ15]. In
cluster 4, the tolyl ligand acts as a 6e donor, while the
methylidyne unit donates 3e
/
ꢂ
Starting materials [Os Rh(m-H) (CO) ] [7], [Os (m-
3
3
12
3
ꢂ
H) (CO) ] [16] and [{Rh(CO) Cl} ] [17] were prepared
2 10 2 2
to the metal core.
according to literature procedures. All chemicals, unless
otherwise stated, were purchased commercially and used
as received. Infrared spectra were recorded on a Bio-
Together with nine terminal carbonyl ligands, a CVE
count of 60 is obtained, which is electron precise
according to the EAN rule.
Rad FTS-165 IR spectrometer, using 0.5 mm CaF
2
1
solution cells. H-NMR was obtained on a Bruker
2
.1.3. Thermolysis of [Os Rh(m-H) (CO) ] in toluene
3 3 12
DPX400 spectrometer using CD Cl or CDCl3 and
2
2
Heating of 1 in toluene to reflux for 2 h led to the
6
referenced to SiMe4 (dꢁ0). Positive ionization fast
/
known cluster [Os Rh(m-H) (h -C H CH )(CO) ] in
3
3
6
5
3
9
atom bombardment (FAB) mass spectra were recorded
on a Finnigan MAT 95 mass spectrometer, using 3-
nitrobenyl alcohol as matrix solvent. GCMS spectra
were obtained on a GCD series II gas chromatograph
electron ionization detector. Elemental analyses were
performed by Department of Chemistry, City University
of Hong Kong.
good yield [8]. Hence the formation of higher nuclearity
cluster 2 should involve the coordination of vinyl group
to the metal core. Reaction of 1 with refluxing toluene in
the presence of cyclohexene gave 2 in 20% yield as the
only isolable product. It is tempting to suggest that the
metal hydrides may interact with the coordinated alkene
and open up new paths of 1 other than the substitution
of CO by toluene.
3.2. Reaction of [Os Rh(m-H) (CO) ] with vinylacetic
acid
3 3 12
2
.1.4. Reaction of [Os Rh(m-H) (CO) ] with 1-octene
3 3 12
Interaction of alkenes with 1 led us to explore the
possible catalytic properties of it towards alkene iso-
merization reactions. Treatment of 1 with an excess
Compound 1 (100 mg, 0.10 mmol) and an excess
amount of vinylacetic acid were stirred at refluxing
3
toluene (50 cm ) for 5 h. The color gradually turned

156
J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ
/158
6
Fig. 3. The molecular structure of [Os
3
Rh(m
3
-CCH
3
)(h -C
6
H
5
CH
3
)(CO) ] (4) with the atom numbering scheme.
9
from yellow to brown. The reaction mixture was
evaporated to dryness. The residue was then redissolved
Table 4
˚
Selected bond distances (A) and angles (8) for cluster 4
3
in CH Cl (3 cm ) and separated by preparative TLC
2
2
Bond distances
with an eluent of n-hexaneꢀCH Cl (1:1 v/v) to yield
/
2 2
Os(1)ÃOs(2)
Os(1)ÃRh(1)
Os(2)ÃOs(3)
Os(2)ÃC(10)
Rh(1)ÃC(10)
C(12)ÃC(17)
C(13)ÃC(14)
C(15)ÃC(16)
2.7888(8) Os(1)ÃOs(3)
2.706(1)
Os(1)ÃC(10)
2.7592(8) Os(2)ÃRh(1)
2.7617(7)
2.07(1)
2.720(1)
2.719(1)
1.41(3)
1.52(2)
1.39(3)
1.45(2)
brown complex 2 (R ꢁ
/0.55, 0.02 mmol, 20%) and
f
orange complex 3 (R ꢁ
/0.35, 0.04 mmol, 40%). Anal.
f
Found for 2: C, 16.3; H, 0.5. Calc. for C H O Os Rh :
5
2
4
8
17
2
2.06(1)
2.00(1)
1.37(2)
1.43(3)
1.37(3)
Os(3)ÃRh(1)
C(12)ÃC(13)
C(12)ÃC(18)
C(14)ÃC(15)
C(16)ÃC(17)
C, 16.7; H, 0.5%. Anal. Found for 3: C, 20.3; H, 1.0.
Calc. for C H O Os Rh : C, 20.3; H, 1.1%.
17 10 13
2
2
3.3. Reaction of [Os Rh(m-H) (CO) ] with
vinylacetate
Bond angles
3 3 12
Os(2)ÃOs(1)ÃOs(3)
Os(2)ÃOs(1)ÃC(10)
Os(3)ÃOs(1)ÃC(10)
Os(1)ÃOs(2)ÃOs(3)
Os(1)ÃOs(2)ÃC(10)
Os(3)ÃOs(2)ÃC(10)
Os(1)ÃOs(3)ÃOs(2)
Os(2)ÃOs(3)ÃRh(1)
Os(1)ÃRh(1)ÃOs(3)
Os(2)ÃRh(1)ÃOs(3)
Os(3)ÃRh(1)ÃC(10)
Os(1)ÃC(10)ÃRh(1)
Os(2)ÃC(10)ÃC(11)
C(14)ÃC(15)ÃC(16)
59.62(2)
47.4(4)
93.1(4)
59.70(2)
47.6(4)
93.3(4)
60.68(2)
59.53(3)
61.21(3)
60.98(3)
96.0(4)
83.4(5)
131(1)
Os(2)ÃOs(1)ÃRh(1)
Os(3)ÃOs(1)ÃRh(1)
Rh(1)ÃOs(1)ÃC(10)
Os(1)ÃOs(2)ÃRh(1)
Os(3)ÃOs(2)ÃRh(1)
Rh(1)ÃOs(2)ÃC(10)
Os(1)ÃOs(3)ÃRh(1)
Os(1)ÃRh(1)ÃOs(2)
Os(1)ÃRh(1)ÃC(10)
Os(2)ÃRh(1)ÃC(10)
Os(1)ÃC(10)ÃOs(2)
Os(2)ÃC(10)ÃRh(1)
C(13)ÃC(14)ÃC(15)
C(15)ÃC(16)ÃC(17)
59.32(3)
59.63(3)
47.2(3)
58.82(3)
59.49(3)
47.0(3)
59.16(2)
61.86(3)
49.4(4)
48.9(4)
85.0(1)
84.1(5)
119(1)
Compound 1 (100 mg, 0.10 mmol) was dissolved in
3
toluene (50 cm ) and excess amount of vinylacetate was
added. The yellow solution was allowed to heat under
reflux for 2 h. The reaction mixture changed to brown
gradually. The solvent was then removed in vacuo and
3
redissolved in CH Cl (3 cm ). The purification with n-
2
2
hexaneꢀ/CH Cl (1:1 v/v) as eluent gave light brown
2 2
complex 4 (R ꢁ
/0.65, 0.04 mmol, 40%) and brown
f
complex 2 (R ꢁ
/
0.55, 0.02 mmol, 20%). Anal. Found
for 4: C, 20.4; H, 1.4. Calc. for C H O Os Rh; C, 20.7;
f
120(1)
120(1)
1
8
11
9
3
H, 1.1%.

J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ
/158
157
Table 5
Crystallographic data and data collection parameters for complexes 2ꢀ
/4
2
3
4
Empirical formula
Formula weight
Crystal dimension (mm)
Crystal system
Os Rh
5
2
O
17
C
24
H
8
×0.5CH
2
Cl
2
Os
2
Rh
2
C
17
H
10
O
13
3 9 18 11
Os RhO C H
1746.36
1008.47
1044.79
0.22ꢄ0.21ꢄ0.19
Monoclinic
0.19ꢄ0.16ꢄ0.15
Monoclinic
C2/c (#15)
25.540(2)
0.22ꢄ0.18ꢄ0.17
Monoclinic
P2 /n (#14)
Space group
˚
1
1
P2 /c (#14)
a (A)
˚
10.073(1)
18.575(1)
12.554(1)
8.698(1)
17.544(2)
14.506(2)
b (A)
22.360(2)
17.484(1)
˚
c (A)
a (8)
b (8)
g (8)
132.25(2)
91.20(1)
92.41(2)
3
˚
V (A )
Z value
7390(2)
8
2348.4(3)
4
2211.6(4)
4
D
calc (g cmꢂ3
)
3.139
6148.00
180.81
298
2.852
1832.00
122.21
298
3.138
1856.00
179.47
298
F(000)
m (Moꢀ
/K
a
(cmꢂ1))
Temperature (K)
Reflection collected
Unique reflection
Observed reflection [I ꢀ1.50s(I)]
R
22 750
8439
5746
14 651
5449
3654
13 413
5095
4249
0.044
0.050
0.050
0.050
0.055
0.069
R
w
3
.4. Thermolysis of [Os Rh(m-H) (CO) ] in toluene
3
collected at various time intervals showed the presence
of isomeric olefins.
3
12
Compound 1 (100 mg, 0.10 mmol) was refluxed in
toluene. The color turned into light brown gradually.
The solution was evaporated to dryness and the residue
was separated by preparative TLC with solution mixture
3
.7. Crystallography
All pertinent crystallographic data and other experi-
of n-hexaneꢀ/CH Cl (2:1 v/v) as eluent. The separation
2 2
mental details are summarized in Table 5. Crystals
suitable for X-ray analyses were glued on glass fibers
with epoxy resin or sealed in a 0.3 mm glass capillary.
Intensity data were collected at ambient temperature on
a Bruker AXS SMART CCD diffractometer equipped
yielded a major orange complex (R ꢁ
/0.65, 0.04 mmol,
f
4
0%).
3.5. Reaction of [Os Rh(m-H) (CO) ] with
3 3 12
cyclohexene in toluene
with graphite-monochromated Moꢀ
.71073). All structures were solved by direct methods
SHELX-86 [18] for 2 and 4; SIR-92 for 3 [19]) and
expanded by Fourier-difference technique (DIRDIF-94
20]. Non-hydrogen atoms were refined anisotropically
/
K radiation (lꢁ
/
a
0
(
Compound 1 (100 mg, 0.10 mmol) and an excess
3
amount of cyclohexene was refluxed in toluene (50 cm )
)
[
under an inert atmosphere, respectively. The colour
gradually turns from yellow to brown in the reaction.
The brown solution was concentrated under reduced
pressure and separated by preparative TLC with n-
for 3 and 4. For 2, some non-hydrogen atoms were
refined anisotropically while the rest were refined
isotropically. Hydrogen atoms were generated in their
ideal position and included in the structure factor
calculations but not refined. Calculations were per-
formed on a Silicon Graphics computer using TEXSAN
hexaneꢀCH Cl (1:1 v/v) to give a brown complex 2
/
2 2
(
R ꢁ0.55, 0.03 mmol, 30%).
/
f
[
21] crystallographic software package.
3
.6. Reaction of [Os Rh(m-H) (CO) ] with 1-octene
3 3 12
A solution of 1 (100 mg, 0.10 mmol) in n-heptane (40
3
4. Supplementary data
cm ) was stirred with excess amount of 1-octene at three
different temperatures, i.e. 25, 60 and 100 8C for 24 h,
respectively. The reaction mixtures were collected and
analyzed by GCMS spectroscopy as indicated above.
For the reactions at 60 and 100 8C, GCMS spectra
Crystallographic data (excluding structure factors) for
the structures reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre
(CCDC) as supplementary publication no. CCDC

158
J. Po-Kwan Lau, W.-T. Wong / Journal of Organometallic Chemistry 659 (2002) 151ꢀ158
/
[
[
6] S.Y.W. Hung, W.T. Wong, Chem. Commun. (1997) 2099.
7] P. Sundberg, B. Noren, B.F.G. Johnson, J. Lewis, P.R. Raithby,
J. Organomet. Chem. 353 (1988) 383.
1
86412; CCDC 186414. Copies of the data can be
obtained free of charge on application to The
Director, CCDC, 12 Union Road, Cambridge CB2
1
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
[
[
8] S.G. Shore, W.L. Hsu, J. Am. Chem. Soc. 105 (1983) 655.
9] S.G. Shore, W.L. Hsu, C.R. Weisenberg, M.L. Caste, M.R.
Churchill, C. Bueno, Organometallics 1 (1982) 1405.
EZ, UK (Fax: ꢃ44-1223-336033; e-mail: deposit@
/
[
[
[
10] W. Clegg, M. Green, C.A. Hall, D.C.R. Hockless, N.C. Norman,
C.M. Woolhouse, J. Chem. Soc. Chem. Commun. (1990) 1330.
11] K. Osakada, A. Grohmann, A. Yamamoto, Organometallics 9
Acknowledgements
(
1990) 2092.
12] R. Kakino, K. Nagayama, Y. Kayaki, I. Shimizu, A. Yamamoto,
Chem. Lett. (1999) 685.
We gratefully acknowledge financial support from the
Hong Kong Research Grants Council and The Uni-
versity of Hong Kong.
[13] L.L. Kesmodel, L.H. Dubois, G.A. Somorjai, J. Chem. Phys. 70
1979) 2180.
(
[
[
[
14] M. Simonetta, A. Gavezzotti, Theochemistry 107 (1984) 75.
15] M. Rashidi, R.J. Puddephatt, Organometallic 7 (1988) 1636.
16] E. Sappa, M. Ville, Inorg. Synth. 26 (1989) 367.
References
[17] J.A. McCleverty, J. Bray, Inorg. Synth. 15 (1975) 14.
[
18] G.M. Sheldrick, in: G.M. Sheldrick, C. Kruger, R. Goddard
(Eds.), Crystallographic Computing, vol. 3, Oxford University
Press, 1985, p. 175.
[
1] P. Braunstein, J. Ros e´ , in: R.D. Adams, F.A. Cotton (Eds.),
Catalysis by Di and Polynuclear Metal Cluster Complexes, Wiley-
VCH, New York, 1998.
[19] G. Cascarano, L. Favia, C. Giacovazzo, J. Appl. Crystallogr. 25
(1992) 310.
[
2] S. Hermans, R. Raja, J.M. Thomas, B.F.G. Johnson, G. Sankar,
D. Gleeson, Angew. Chem. Int. Ed. 40 (2001) 1211.
3] S. Hermans, J. Sloan, D.S. Shephard, B.F.G. Johnson, M.L.H.
Green, Chem. Commun. (2002) 276.
[20] DIRDIF-94: B.T. Beurskens, G. Admiroal, G. Beurskens, W.P.
Bosman, R. de Gelder, R. Isrel, J.M.M. Smits, Technical Report
of the Crystallography Laboratory, University of Nijmegen, 1994.
[21] TEXSAN, Crystal Structure Analysis Package, Molecular Structure
Corporation, Houston, TX, 1985 and 1992.
[
[
[
4] W.T. Wong, Organometallics 18 (1999) 3474.
5] S.Y.W. Hung, W.T. Wong, J. Organomet. Chem. 580 (1999) 48.