Triosmium clusters containing bridging dppm and EPh (E = S, Te) ligands: X-ray structures of [(μ-H)Os3(CO)7(μ-SPh) {μ3-η4-Ph2PCHP(Ph)C6H 4}], [Os3(CO)8(μ-SPh)2(μ-dppm) ] and [Os3(CO)8(μ-TePh)2(μ-dppm)]

Article abstract of DOI:10.1016/j.jorganchem.2005.08.034

Heating [Os₃(CO)₁₀(μ-dppm)] (1) with two equivalents of PhSSPh in toluene under reflux provided three new triosmium compounds [(μ-H)Os₃(CO)₇(μ-SPh){μ₃- η⁴-Ph₂PCHP(Ph)C₆H₄}] (2), [Os₃(CO)₈(μ-SPh)₂(μ-dppm)] (3) and [(μ-H)Os₃(CO)₇(μ-η²-SC ₆H₄)(μ-SPh)(μ-dppm)] (4) in 20%, 21% and 26% yields, respectively. In contrast, a similar reaction of 1 with two equivalents of PhTeTePh in refluxing toluene gave the binuclear compound [Os ₂(CO)₄(μ-TePh)₂(μ-dppm)] (6) in 15% yield, and two 50 electron isomeric compounds 5 and 7 with the formula [Os ₃(CO)₈(μ-TePh)₂(μ-dppm)] in 20% and 23% yields, respectively. Thermolysis of 3 at 110 °C afforded 4 in 53% yield which on further thermolysis in refluxing octane at 128 °C gave 2 in 45% yield. Thermolysis of 3 in refluxing octane also gave 2 in 50% yield. The new compounds, 2-7, were all spectroscopically characterized, and the X-ray structures of 2, 3 and 7 have been determined. Compound 2 contains a bridging SPh ligand and a μ₃,η⁴-Ph₂PCHP(Ph)C ₆H₄ ligand, formed by two kinds of C-H activation, including orthometallation of a phenyl group as well as an unusual activation of the methylene group of the dppm ligand. The molecular structure of 3 reveals that two SPh groups span the open Os-Os edge of the Os₃ triangle, while the dppm ligand bridges one of the closed Os-Os edges. In compound 7, one TePh group spans the open Os-Os edge, while the other spans one of the two closed Os-Os edges and the dppm ligand bridges the third Os-Os vector.

Full text of DOI:10.1016/j.jorganchem.2005.08.034

Journal of Organometallic Chemistry 691 (2006) 97–104
www.elsevier.com/locate/jorganchem
Triosmium clusters containing bridging dppm
and EPh (E = S, Te) ligands: X-ray structures of
[(l-H)Os3(CO)7(l-SPh){l3-g4-Ph2PCHP(Ph)C6H4}], [Os3(CO)8-
(l-SPh)2(l-dppm)] and [Os3(CO)8(l-TePh)2(l-dppm)]
a,
a
,b
*
Shariff E. Kabir *, Madhu S. Saha , Derek A. Tocher
,
c
,d
*
G.M. Golzar Hossain , Edward Rosenberg
a
Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh
Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
b
c
Department of Chemistry, Cardiff University, P.O. Box 912, Cardiff CF10 3TB, UK
Department of Chemistry, The University of Montana, Missoula, MT 59812, USA
d
Received 14 July 2005; received in revised form 26 August 2005; accepted 26 August 2005
Available online 11 October 2005
Abstract
Heating [Os3(CO)10(l-dppm)] (1) with two equivalents of PhSSPh in toluene under reflux provided three new triosmium compounds
[(l-H)Os3(CO)7(l-SPh){l3-g4-Ph2PCHP(Ph)C6H4}] (2), [Os3(CO)8(l-SPh)2(l-dppm)] (3) and [(l-H)Os3(CO)7(l-g2-SC6H4)(l-SPh)(l-
dppm)] (4) in 20%, 21% and 26% yields, respectively. In contrast, a similar reaction of 1 with two equivalents of PhTeTePh in refluxing
toluene gave the binuclear compound [Os2(CO)4(l-TePh)2(l-dppm)] (6) in 15% yield, and two 50 electron isomeric compounds 5 and 7
with the formula [Os3(CO)8(l-TePh)2(l-dppm)] in 20% and 23% yields, respectively. Thermolysis of 3 at 110 ꢀC afforded 4 in 53% yield
which on further thermolysis in refluxing octane at 128 ꢀC gave 2 in 45% yield. Thermolysis of 3 in refluxing octane also gave 2 in 50%
yield. The new compounds, 2–7, were all spectroscopically characterized, and the X-ray structures of 2, 3 and 7 have been determined.
Compound 2 contains a bridging SPh ligand and a l3,g4-Ph2PCHP(Ph)C6H4 ligand, formed by two kinds of C–H activation, including
orthometallation of a phenyl group as well as an unusual activation of the methylene group of the dppm ligand. The molecular structure
of 3 reveals that two SPh groups span the open Os–Os edge of the Os3 triangle, while the dppm ligand bridges one of the closed Os–Os
edges. In compound 7, one TePh group spans the open Os–Os edge, while the other spans one of the two closed Os–Os edges and the
dppm ligand bridges the third Os–Os vector.
ꢁ 2005 Elsevier B.V. All rights reserved.
Keywords: Triosmium carbonyl clusters; Diphenyldisulfide; Diphenylditelluride; Bis(diphenylphosphino)methane; X-ray structures
1. Introduction
ide atoms appears to often be decisive in cluster aggrega-
tion and condensation reactions [4–10]. The main entry
into chalcogenido carbonyl species is by the facile oxidative
addition of Ph3P@E (E = S, Se, Te) to zero-valent metal
centers which commonly generates tertiary phosphine
substituted clusters with capping chalcogenide elements
[11]. Another approach to the synthesis of bridging chalco-
genide metal carbonyl clusters is the cleavage of E–E bonds
of diphenyldichalcogenide ligands [12]. For example, Lewis
et al. [13] and Arce et al. [14] reported that the reaction of
Transition metal carbonyl compounds containing chal-
cogen atoms have attracted much attention in recent years
owing to their importance in fundamental research as well
as in technological fields [1–3]. The presence of chalcogen-
*
Corresponding author. Tel.: +1 406 243 2592; fax: +1 406 243 2477.
E-mail addresses: skabir_ju@yahoo.com (S.E. Kabir), d.a.tocher@
ucl.ac.uk (D.A. Tocher).
0022-328X/$ - see front matter ꢁ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.08.034

98
S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
[Os3(CO)12 À n(MeCN)n] (n = 1 or 2) with PhSeSePh affor-
ded the 50 electron cluster [Os3(CO)10(l-SePh)2] in which
one SePh group bridged a closed Os–Os edge and the other
an open Os–Os edge. Recently, Leong and Zhang [15] re-
ported the corresponding tellurium analog [Os3(CO)10(l-
TePh)2] from the reaction between [Os3(CO)10(MeCN)2]
and PhTeTePh. Thermolysis of both [Os3(CO)10(l-SePh)2]
and [Os3(CO)10(l-TePh)2] at 80 ꢀC was reported to lead to
an isomer in which both the EPh (E = Se, Te) moieties
bridge the same open metal–metal edge.
The reactions of the bridging dppm triosmium cluster
[Os3(CO)10(l-dppm)] (1) with a variety of small inorganic
and organic ligands have been reported to give many inter-
esting molecules because of the ability of the dppm ligand
to keep the metal cluster fragment intact during chemical
reactions [16]. However, there are examples in which the
diphosphine ligands can undergo C–H and P–C bond
cleavage and M–H and M–C bond forming reactions
[17,18]. We have previously reported [19] the reaction of
[Os3(CO)10(l-dppm)] with PhSeSePh at 110 ꢀC, which al-
lows isolation of the binuclear compound [Os2(CO)4(l-
SePh)2(l-dppm)], three 50 electron isomeric compounds
with formula [Os3(CO)8(l-SePh)2(l-dppm)] and the
benzyne compound [Os3(CO)6(l-CO)(l-Se)2(l-C6H4)(l-
dppm)]. Herein, we report our results on the investigations
of the reactions of 1 with PhSSPh and PhTeTePh in order
to understand the impact of the nature of the calcogenide
on the structure of the products obtained.
[(l-H)Os3(CO)7(l-SPh){l3-g4-Ph2PCHP(Ph)C6H4}] (2),
[Os3(CO)8(l-SPh)2(l-dppm)] (3) and [(l-H)Os3(CO)7(l-
g2-SC6H4)(l-SPh)(l-dppm)] (4) in 20%, 21% and 26%
yields, respectively (Scheme 1). The compounds have been
characterized by elemental analysis, IR, 1H NMR,
31P{1H}NMR, mass spectroscopic data together with sin-
gle crystal X-ray diffraction studies for 2 and 3.
The molecular structure of 2 is shown in Fig. 1, crystal
data are given Table 1 and selected bond distances and
angles are given in Table 2. The Os3 core in 2 represents
a scalene triangle with three distinctly different Os–Os bond
lengths {Os(1)–Os(2) = 3.0523(3), Os(2)–Os(3) = 2.8995(3)
˚
and Os(1)–Os(3) = 2.8495(3) A}. These bond lengths are
2. Results and discussion
The reaction of [Os3(CO)10(l-dppm)] (1) with two equiv-
alents of diphenyldisulfide in refluxing toluene, followed by
chromatographic separation, gave three new compounds
Fig. 1. Solid-state molecular structure of [(l-H)Os3(CO)7(l-SPh)(l3-g4-
Ph2PCHPhPC6H4)] (2). Thermal ellipsoids are drawn at 50% probability
level.
Ph
S
(CO)4
Os
(CO)
3Os
Os(CO)2
toluene
110 oC
H
PhSSPh
+
+
Os(CO)2
(CO)3 Os
Ph2P
Os(CO)3
PPh2
PPh2
PhP
C
H
C
H2
2
1
(CO)3
Os
(CO)3
Os
S
PhS
SPh
PhS
(CO)2 Os
Ph2P
Os(CO)2
PPh2
+
(CO)3
Os
Os(CO)2
PPh2
H
Ph2P
C
H2
C
H2
4
3
Scheme 1.

S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
99
Table 1
Crystallographic data and structure refinement for 2, 3 and 7
2
3 Æ H2O Æ H2S
7
Formula
C
38H25O7Os3P2S
C45H36O9Os3P2S3
1449.46
150(2)
C45H32O8Os3P2Te2
1588.45
150(2)
Orthorhombic
Pbca
Formula weight
Temperature (K)
Crystal system
Space group
1258.18
293(2)
Triclinic
Triclinic
ꢀ
ꢀ
P1
P1
˚
a (A)
10.3719(5)
11.7890(5)
16.6625(8)
78.3540(10)
76.3130(10)
66.9870(10)
1808.33(14)
2
11.9787(2)
12.3035(2)
16.9587(3)
94.2600(10)
97.7520(10)
107.7820(10)
2340.49(7)
21.6362(11)
18.0333(9)
22.8700(12)
90
90
90
8923.2(8)
8
2.365
9.928
5824
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
3
˚
V (A )
Z
2
Dcalc (mg mÀ3
)
2.311
10.710
1166
2.057
8.378
1368
l (Mo Ka) (mmÀ1
F(000)
)
Crystal size (mm)
h range (ꢀ)
Limiting indices
0.36 · 0.18 · 0.05
1.89–28.31
À13 6 h 6 13, À15 6 k 6 15,
À22 6 l 6 22
16106
8386 [0.0339]
0.6165 and 0.1134
8386/0/460
0.25 · 0.20 · 0.12
2.93–27.49
À15 6 h 6 15, À15 6 k 6 15,
À21 6 l 6 22
43599
10668 [0.0949]
0.4330 and 0.2285
10668/0/568
1.052
0.23 · 0.14 · 0.04
1.72–28.32
À28 6 h 6 27, À23 6 k 6 23,
À30 6 l 6 30
Number of reflections collected
Number of independent reflections [Rint
Max. and min. trans.
Data/restraints/parameters
Goodness-of-fit on F2
76686
]
10912 [0.0615]
0.6922 and 0.2086
10912/0/541
1.026
1.177
Final R indices [I > 2r(I)]
R indices (all data)
Largest diff. peak and hole (e A
R1 = 0.0316, wR2 = 0.0782
R1 = 0.0344, wR2 = 0.0799
3.311 and À2.279
R1 = 0.0465, wR2 = 0.01147
R1 = 0.0648, wR2 = 0.1245
2.440 and À2.628
R1 = 0.0365, wR2 = 0.0665
R1 = 0.0439, wR2 = 0.0686
1.283 and À1.198
À3
˚
)
Table 2
˚
all in accord with other documented Os–Os single bond
lengths. The fact that the Os(1)–Os(2) bond length is signif-
icantly longer than the Os(2)–Os(3) and Os(1)–Os(3) edges
provides support for the presence of the bridging hydride
on this edge [20] and this also makes the individual metal
centers electron- precise. The seven carbonyl ligands are
all in terminal positions with two linked to osmium atoms
Os(1) and Os(3) and three linked to Os(2). The most strik-
ing feature of the structure is that the dppm ligand has been
transformed into a unique l3-g4-Ph2PCHP(Ph)C6H4 coor-
dination mode with two phosphorus atoms coordinating
axially at the Os(2)–Os(3) edge. The C(7) atom of the meth-
ylene of the dppm ligand occupies an axial coordination
site on Os(1). The structure shows that two kinds of C–H
activation, orthometallation of one of the phenyl groups
as well as the unusual activation of the methylene group
of the dppm ligand occur in the transformation. Thermol-
ysis of [Os3(CO)9(CNPr)(l-dppm)] in refluxing toluene has
been reported to produce [(l-H)2Os3(CO)7(CNR){l3-g4-
Ph2PCHP(Ph)C6H4}], containing a l3,g4-Ph2PCHP(Ph)-
C6H4 ligand [17] and this appears to be the second example
of this coordination of the diphosphine ligand on a trios-
mium center. The l3-g4-Ph2PCHP(Ph)C6H4 ligand in 2 is
bonded to three osmium atoms through P(1), P(2), C(7)
and C(71) atoms (Os(3)–P(1) = 2.3736(11), Os(2)–P(2) =
2.4085(11), Os(1)–C(7) = 2.240(4), and Os(1)–C(71) =
Selected bond distances (A) and angles (ꢀ) for [(l-H)Os3(CO)7(l-SPh)(l3-
g4-Ph2PCHPhPC6H4)] (2)
Os(1)–C(12)
Os(1)–C(71)
Os(1)–Os(3)
Os(1)–Os(2)
Os(2)–C(23)
Os(2)–P(2)
Os(2)–Os(3)
Os(3)–C(31)
Os(3)–P(1)
Os(1)–C(11)
Os(1)–C(7)
Os(1)–P(2)
Os(2)–C(21)
Os(2)–C(22)
Os(2)–S(1)
Os(3)–C(32)
Os(3)–S(1)
S(1)–C(1)
1.854(5)
2.080(5)
2.8495(3)
3.0523(3)
1.933(5)
2.4085(11)
2.8995(3)
1.908(5)
2.3736(11)
1.893(5)
2.240(4)
2.8504(11)
1.913(5)
1.941(5)
2.4528(11)
1.875(5)
2.3619(11)
1.789(5)
C(71)–Os(1)–Os(3)
C(71)–Os(1)–Os(2)
P(2)–Os(2)–Os(3)
Os(3)–Os(2)–Os(1)
P(1)–Os(3)–Os(2)
P(1)–C(7)–P(2)
C(71)–Os(1)–C(7)
Os(3)–Os(1)–Os(2)
S(1)–Os(2)–Os(3)
S(1)–Os(3)–Os(2)
Os(3)–S(1)–Os(2)
Os(1)–Os(3)–Os(2)
143.14(13)
87.30(13)
90.32(3)
57.140(6)
92.30(3)
118.3(2)
81.00(18)
58.730(6)
51.55(3)
54.42(3)
74.03(3)
64.130(7)
˚
2.080(5) A) leading to two four-membered and one five-
membered metallocycles, Os(1)–C(7)–P(1)–Os(3), Os(1)–

100
S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
Table 3
C(7)–P(1)–Os(3), and Os(2)–P(2)–C(7)–P(1)–Os(2). Another
interesting feature of the structure is that the two phospho-
rus atoms of the diphosphine ligand are coordinating
axially at the Os(2)–Os(3) vector and the Os–P bond
distances are significantly longer than those reported for
the orthometallated compound [(l-H)Os3(CO)8{Ph2PCH2-
P(Ph)C6H4}] [16b]. Another feature of interest in 2 is
the l-SPh group which asymmetrically spans the Os(2)–
Os(3) edge {Os(2)–S(1) = 2.4528(11) and Os(3)–S(1) =
˚
Selected bond distances (A) and angles (ꢀ) for [Os3(CO)8(l-SPh)2(l-
dppm)] (3)
Os(1)–C(1)
Os(1)–P(1)
Os(1)–S(1)
Os(2)–C(4)
Os(2)–C(5)
Os(2)–Os(3)
Os(3)–C(8)
Os(3)–S(2)
P(1)–C(9)
S(1)–C(34)
Os(1)–C(2)
Os(1)–S(2)
Os(1)–Os(2)
Os(2)–C(3)
Os(2)–P(2)
Os(3)–C(7)
Os(3)–C(6)
Os(3)–S(1)
P(1)–C(9)
1.891(8)
2.324(2)
2.4515(18)
1.895(8)
1.954(8)
2.8915(4)
1.904(9)
2.4339(19)
1.820(8)
1.800(8)
1.906(11)
2.443(2)
2.9273(4)
1.943(9)
2.336(2)
1.903(9)
1.907(9)
2.4434(19)
1.833(8)
1.786(8)
˚
2.3619(11) A} and the average Os–S bond distance
˚
{2.407(2) A} is similar to that observed in [(l-H)Os3(CO)8-
(l-SEt)(l-dppm)] although the thiolato group in the latter
is symmetrically bridged [21].
Spectroscopic data in solution for 2 are in agreement
with the structure observed in solid-state. Compound 2
exhibits IR bands due to terminal carbonyl ligands only.
1
The hydride region of the H NMR spectrum of 2 shows
a doublet at d À15.0 with a phosphorus–hydrogen coupling
constant of 18.0 Hz. In addition to the phenyl resonances
S(2)–C(40)
1
of the dppm ligand the H NMR spectrum in the aliphatic
P(1)–Os(1)–S(2)
S(2)–Os(1)–S(1)
S(2)–Os(1)–Os(2)
P(2)–Os(2)–Os(1)
S(2)–Os(3)–S(1)
S(1)–Os(3)–Os(2)
Os(3)–S(2)–Os(1)
P(1)–Os(1)–S(1)
P(1)–Os(1)–Os(2)
S(1)–Os(1)–Os(2)
Os(3)–Os(2)–Os(1)
S(2)–Os(3)–Os(2)
Os(3)–S(1)–Os(1)
P(1)–C(9)–P(2)
164.08(6)
region contains a double doublets at d 5.14 with P–H cou-
pling constants of 10.4 and 3.2 Hz which integrated for one
proton and is assigned to the CH group of dppm, suggest-
ing that one of the methylene hydrogens has been acti-
vated. The 31P {1H} NMR spectrum of 2 contains two
doublets at d À18.4 and À28.7 (J = 91.4 Hz), indicating
non-equivalent 31P nuclei. The fused rings in 2 are con-
nected by edge sharing and severe twist of the rings sug-
gests unusual ring size effect of the l3-g4-coordinated
dppm ligand and reflects up field 31P chemical shifts of
the phosphorus atoms. The FAB mass spectrum shows
the molecular ion peak at m/z 1260 and ions due to the sub-
sequent loss of seven carbonyl ligands.
82.56(6)
79.70(4)
90.97(5)
82.91(6)
76.51(4)
89.65(7)
97.89(7)
84.98(5)
75.71(4)
72.427(10)
80.58(5)
89.23(6)
113.9(4)
three osmium atoms with two almost equal metal–metal
bonds {Os(1)–Os(2) = 2.9273(4) and Os(2)–Os(3) =
2.8915(4) A}, eight terminal carbonyl groups, two bridg-
The molecular structure 3 is shown in Fig. 2, crystal
data and structure refinement parameters are given in
Table 1 and selected bond distances and angles are given
in Table 3. The molecule consists of an open cluster of
˚
ing phenylsulfide groups and a bridging dppm ligand.
Among the eight carbonyl ligands, three each are bonded
to the two osmium atoms Os(2) and Os(3) and two are
bonded to Os(1). The Os(1)–Os(2) edge is bridged by
the dppm ligand and the open Os(1). . .Os(3) edge is
symmetrically bridged by two SPh groups {Os(1)–
S(1) = 2.4515(18), Os(3)–S(1) = 2.4434(19); Os(1)–S(2) =
˚
2.443(2) and Os(3)–S(2) = 2.4339(19) A}. The Os–P
bond distances {Os(1)–P(1) = 2.324(2) and Os(2)–P(2) =
˚
2.336(2) A} are very similar to those reported for 1
˚
{2.332(3) and 2.324(7) A} [22]. The overall structure of
3 is similar to that of the Se analog [Os3(CO)8(l-SePh)2-
(l-dppm)] which was synthesized from the reaction of 1
with PhSeSePh and cha-racterized by a single crystal
X-ray diffraction analysis [19].
The spectroscopic data for 3 are consistent with the
solid-state structure. The pattern of the infrared spectrum
of 3 is very similar to that observed for [Os3(CO)8(l-SePh)2-
1
(l-dppm)] [19]. The H NMR spectrum of 3 displays the
expected signals for the dppm and SPh ligands, while the
Fig. 2. Solid-state molecular structure of [Os3(CO)8(l-SPh)2(l-dppm)] (3).
Thermal ellipsoids are drawn at 50% probability level.
31P {1H} NMR spectrum exhibits two doublets at d 20.8

S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
101
and 17.3 (J = 69.8 Hz) corresponding to two non-equiva-
lent 31P nuclei. The FAB mass spectrum shows the molec-
ular ion peak at m/z 1398 and fragmentation peaks due to
the sequential loss of eight carbonyl ligands.
The reaction of 1 with two equivalents of diphenylditel-
luride in refluxing toluene gave the binuclear compound
[Os2(CO)4(l-TePh)2(l-dppm)] (6) in 15% yield, and two
50 electron isomeric compounds 5 and 7 with the formula
[Os3(CO)8(l-TePh)2(l-dppm)] in 20%, and 23% yields,
respectively (Scheme 2). We were unable to obtain X-ray
quality crystals of 5 and 6, therefore their characterization
is based on elemental analysis, infrared, 1H NMR, 31P{1H}
NMR and mass spectroscopic data. Compound 7 has been
characterized by a combination of spectroscopic data and
single crystal X-ray diffraction analysis. For 5, IR carbonyl
stretching bands at 2058 vs, 2014 m, 1983 vs, and 1935 w
cmÀ1 indicate that only terminal carbonyl groups are pres-
ent in the molecule. The mass spectrum of 5 exhibits a
molecular ion peak at m/z 1590 and sequential loss of eight
carbonyls groups were observed. In addition to the usual
phenyl protons for the dppm and TePh ligands the 1H
NMR spectrum of 5 shows two multiplets at d 4.78 and
4.48 due to the methylene protons of the dppm ligand.
The 31P{1H} NMR spectrum of 5 contains two doublets
at d 4.1 and À5.6 (J = 74.6 Hz) due to the two non-equiv-
alent 31P nuclei. These data are consistent with proposed
structure for 5 with dppm and TePh groups bridging at dif-
ferent Os–Os edge of osmium triangle.
Compound 6 has also been characterized spectroscopi-
cally. The binuclear formulation of 6 was indicated by its
elemental analysis and mass spectrum which exhibits the
molecular ion peak at m/z 1288 and ions due to the sequen-
tial loss of four carbonyls groups. The infrared spectrum
contains three m(CO) bands at 2016 vs, 1993 s, and 1927
m cmÀ1, a very similar IR spectrum to that observed for
[Os2(CO)2(l-SePh)2(l-dppm)] which was characterized by
a single crystal X-ray diffraction studies.19 In addition to
phenyl resonances for the dppm and TePh ligands at d
8.15–6.98 the 1H NMR spectrum of 6 shows two multiplets
The infrared spectrum of 4 shows all the carbonyl
groups are terminal. In addition to the usual phenyl proton
1
resonances the aromatic region of the H NMR spectrum
of 4 contains four well separated signals, two doublets at
d 7.82 (J = 8.0 Hz) and 7.72 (J = 8.0 Hz) and two triplets
at d 7.61(J = 8.0 Hz) and 7.21 (J = 8.0 Hz) each integrating
for one hydrogen. The doublets at d 7.82 and 7.72 are as-
signed to the protons on C(3) and C(6) interchangably
while the triplets at d 7.61 and 7.21 are due to the protons
on C(4) and C(5) interchangeably. The aliphatic region of
the spectrum contains two multiplets at d 3.10 and 1.71
due to the methylene protons of the dppm ligand. The hy-
dride region of the spectrum exhibits a triplet at d À15.55.
The 31P {1H} NMR spectrum contains two doublets at d
20.8 and 17.3 due to two non-equivalent 31P nuclei. The
FAB mass spectrum exhibits the molecular ion peak at
m/z 1370 and ions due to the sequential loss of seven car-
bonyl ligands. These data are consistent with the structure
of 4 shown in Scheme 1.
It is reasonable to propose that compound 3 is an inter-
mediate in the formation of 2 and 4. To support this, we
have investigated the thermolysis of both 3 and 4 at differ-
ent temperatures. Thermolysis of 3 in refluxing toluene for
3 h produces 4 by loss of one CO ligand following activa-
tion of a C–H bond of one SPh ligand. As expected, ther-
molysis of 4 in refluxing octane leads to the formation of 2
by loss of a thiophenol molecule. Given these results it
seems reasonable to propose that 3 loses thiophenol and
that one of the subsequent C–H activations which result
in the formation of 2 is coupled to a reductive elimination
of one C–H on the sulfur bound phenyl group.
(CO)4
Os
(CO)3
Os
TePh
PhTe
Toluene
110 oC
PhTeTePh
+
(CO)3Os
Ph2P
Os(CO)3
PPh2
(CO)3Os
Ph2P
Os(CO)2
PPh2
C
C
H2
H2
1
5
+
(CO)3
Os
Ph
Te
Ph
Te
TePh
PhTe
(CO)2Os
Ph2P
Os(CO)2
PPh2
+
(CO)2Os
Ph2P
Os(CO)3
PPh2
C
H2
C
H2
6
7
Scheme 2.

102
S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
Table 4
at d 4.77 and 4.58 due to the methylene protons of the
dppm ligand. The 31P{1H} NMR spectrum shows a single
peak at d À20.8 for the two equivalent phosphorus atoms
of the dppm ligand.
˚
Selected bond distances (A) and angles (ꢀ) for [Os3(CO)8(l-TePh)2(l-
dppm)] (7)
Os(1)–C(12)
Os(1)–C(13)
Os(1)–Te(1)
Os(2)–C(23)
Os(2)–C(22)
Os(2)–Te(1)
Os(3)–C(31)
Os(3)–P(2)
Te(1)–C(41)
Os(1)–C(11)
Os(1)–P(1)
Os(1)–Os(3)
Os(2)–C(21)
Os(2)–Te(2)
Os(2)–Os(3)
Os(3)–C(32)
Os(3)–Te(2)
Te(2)–C(51)
1.903(6)
1.935(6)
2.6946(4)
1.886(7)
1.903(6)
2.7110(4)
1.863(6)
2.3256(14)
2.133(5)
1.951(6)
2.3325(14)
3.0197(3)
1.900(6)
2.672494)
2.9040(3)
1.869(6)
2.6821(4)
2.131(6)
The molecular structure of 7 is shown in Fig. 3, crystal
data and structure refinement parameters are given in
Table 1 and selected bond distances and angles are given
in Table 4. The molecule is a 50 electron triosmium system
with two distinctly different osmium–osmium bonds, one
bridging dppm and two bridging TePh ligands. The eight
carbonyl ligands are all in terminal positions with two
bonded to Os(3) and three bonded to each of the osmium
atoms Os(1) and Os(2). The structure is derived from that
of [Os3(CO)10(l-TePh)2] by replacement of an equatorial
carbonyl group on each of the two osmium atoms of the
non-bridged Os–Os edge with the dppm ligand [15]. The
˚
open Os(1)–Os(2) edge 4.12 A is symmetrically bridged
by one TePh ligand, and the other TePh ligand symmetri-
cally spans the Os(2)–Os(3) edge, while the dppm ligand
bridges the Os(1)–Os(3) edge. The Os–Te bond distances
{Os(1)–Te(1) = 2.6946(4), Os(2)-Te(1) = 2.7110(4), Os(2)–
Te(1)–Os(1)–Os(3)
P(1)–Os(1)–Os(3)
Te(2)–Os(2)–Os(3)
P(2)–Os(3)–Te(2)
Te(2)–Os(3)–Os(2)
Te(2)–Os(3)–Os(1)
Os(2)–Te(2)–Os(3)
P(1)–Os(1)–Te(1)
Te(2)–Os(2)–Te(2)
Te(1)–Os(2)–Os(3)
P(2)–Os(3)–Os(2)
P(2)–Os(3)–Os(1)
Os(1)–Te(1)–Os(2)
P(1)–C(1)–P(2)
84.033(10)
91.62(4)
57.317(10)
110.47(4)
56.997(10)
90.054(11)
65.686(10)
175.43(4)
79.114(12)
86.013(10)
165.74(4)
85.05(4)
˚
Te(2) = 2.6724(4) and Os(3)–Te(2) = 2.6821(4) A} are
comparable to those observed in [Os3(CO)10(l-TePh)2]
˚
{2.7274(9)–2.6886(10) A} [15]. The Os(1)–Te(1)–Os(2)
angle {99.215(13)ꢀ} involving the open Os–Os edge is signifi-
cantly larger than the Os(2)–Te(2)–Os(3) angle {65.686(10)}
involving the bridged Os–Os edge. The dppm bridged
˚
Os(1)–Os(3) edge {3.0197(3) A} is significantly longer than
˚
that of the Os(2)–Os(3) edge {2.9040(3) A) and the dppm
99.215(13)
113.2(3)
˚
bridging edge in 1 {2.8712(8) A}. The Os–P bond lengths
˚
{Os(3)–P(2) = 2.3256(14) and Os(1)–P(1) = 2.3225(14) A}
peak at m/z 1590 and fragmentation peaks due to the
sequential loss of eight carbonyl ligands. In addition to
the phenyl resonances for the dppm and TePh ligands the
1H NMR spectrum shows a overlapping multiplets at d
4.35 integra- ting for two hydrogen atoms due to the meth-
ylene protons of the dppm ligand. The 31P{1H} NMR spec-
trum contains two doublets at d 14.1 and 4.2 with
phosphorus–phosphorus coupling constant of 81.2 Hz,
indicating non-equivalent 31P nuclei.
are very similar to those observed for 3 and 1.
The spectroscopic data for 7 are consistent with the
solid-state structure. The pattern of the infrared spectrum
is similar to that of the Se analog [Os3(CO)8(l-SePh)2-
(l-dppm). The mass spectrum exhibits the molecular ion
3. Conclusions
Having now completed the studies of the reactions of
the entire chalcogenide triad of PhEEPh with 1 a few gen-
eral conclusions can be made. The larger members of the
triad Se and Te clearly lead to more Os–Os bond opening
and even to fragmentation of the cluster in spite of the
presence of the dppm ligand, which in general tends to hold
the osmium triangle together. The diphenyldisulfide on the
other hand with its smaller chalcogenide atom leads ulti-
mately only to closed trinuclear products. However, in
the case of the more sterically encumbered dppm derivative
the product resulting from initial oxidative addition of he
S–S bond to the cluster is less stable than the parent
carbonyl complex and leads to reductive elimination of
thiophenol and to subsequent C–H activation processes
Fig. 3. Solid-state molecular structure of [Os3(CO)8(l-TePh)2(l-dppm)]
(7). Thermal ellipsoids are drawn at 50% probability level.

S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
103
involving both the SPh and dppm ligands, in order to sat-
isfy the electronic requirements of the cluster. These con-
clusions should prove useful in utilizing this synthetic
approach for cluster condensation reactions and for mod-
eling heterogeneous catalyst systems.
7.50–6.76(m, 25H), 7.82 (d, 1H, J = 8.0 Hz), 7.72 (d, 1H,
J = 8.0 Hz), 7.61(J = 8.0 Hz), 7.21 (J = 8.0 Hz) 3.10 (m.
1H), 1.71(m, 1H), À15.55 (t, J = 8.2 Hz); 31P{1H} NMR-
(CD2Cl2): d 20.8 (d, J = 91.4 Hz)), 17.3 (d, J = 91.4 Hz);
FAB MS: m/z 1370 (M+).
4. Experimental
4.2. Thermolysis of 3
Unless otherwise stated, all reactions were carried out
under nitrogen atmosphere using standard Schlenk tech-
niques. Reagent grade solvents were dried and distilled
prior to use by standard methods. Infrared spectra were re-
(a) A toluene solution of 3 (0.015 g, 0.011 mmol) was
heated to reflux under nitrogen for 4 h. Workup
and chromatographic separation as above afforded
4 (0.008 g, 53%).
(b) A similar thermolysis of 3 (0.015 g, 0.011 mmol) in
refluxing octane for 2 h followed by similar chro-
matographic separation gave 2 (0.009 g, 50%).
1
corded on a Shimadzu FT-IR 8101 spectrophotometer. H
and 31P{1H} NMR spectra were recorded on a Varian
Unity Plus 400 spectrometer. Chemical shifts for the
31P{1H} NMR spectra are relative to 85% H3PO4. Ele-
mental analyses were carried out by the Microanalytical
Laboratory at University College London. Fast atom bom-
bardment mass spectra were obtained on a JEOL SX-102
spectrometer using 3-nitrobenzyl alcohol as matrix and
CsI as calibrant. Diphenyldisulfide and diphenylditelluride
were purchased from Aldrich and used as received. The
starting compound [Os3(CO)10(l-dppm)] was prepared
according to the published procedure [16c].
4.3. Thermolysis of 4
An octane solution of 4 (0.015 g, 0.009 mmol) was
heated to reflux for 1.5 h. Workup and chromatographic
separation as above afforded 2 (0.005 g, 45%).
4.4. Reaction of 1 with PhTeTePh
A toluene solution (25 mL) of 1 (0.100 g, 0.081 mmol)
and PhTeTePh (0.066 g, 0.161 mmol) was refluxed for 3 h.
The solvent was removed under reduced pressure and the
residue chromatographed by TLC on silica gel. Elution with
hexane/CH2Cl2 (2:1, v/v) developed three bands. The first
band afforded [Os3(CO)8(l-TePh)2(l-dppm)] (5) (0.026 g,
20%) as yellow crystals after recrystallizaton from hexane/
CH2Cl2 at À20 ꢀC (Anal. Calc. for C45H32O8Os3P2Te2: C,
34.02; H, 2.03. Found: C, 34.33; H, 2.32%). IR (mCO,
4.1. Reaction of [Os3(CO)10(l-dppm)] (1) with PhSSPh
A toluene solution (25 mL) of [Os3(CO)10(l-dppm)]
(0.105 g, 0.085 mmol) and PhSSPh (0.038 g, 0.174 mmol)
was heated to reflux at 110 ꢀC for 3 h during which time
the color changed from yellow to orange. The solvent
was removed under reduced pressure and residue chro-
matographed by TLC on silica gel. Elution with hexane/
CH2Cl2 (7:3, v/v) developed three bands. The first band
afforded [(l-H)Os3(CO)7(l-SPh){l3-g4-Ph2PCHP(Ph)C6H4}]
(2) (0.021 g, 20%) as orange crystals after recrystallization
from hexane/CH2Cl2 at À20 ꢀC (Anal. Calc. for C38H26-
O7Os3P2S: C, 36.24; H, 2.08. Found: C, 36.46; H, 2.22%).
IR (mCO, CH2Cl2): 2080 s, 2012 vs, 1997 s, 1973 w, 1943
CH2Cl2): 2058 s, 2014 m, 1983 vs, 1958 w, 1935 w cmÀ1
;
1H NMR(CD2Cl2): d 7.58–6.55 (m, 30H), 4.78 (m. 1H),
4.48 (m, 1H);31P{1H} NMR(CD2Cl2): d 4.1 (d, J =
74.6 Hz)), À5.6 (d, J = 74.6 Hz); FAB MS: m/z 1590. The
second band yielded [Os2(CO)4(l-TePh)2(l-dppm)] (6)
(0.016 g, 15%) as red crystals from hexane/CH2Cl2 at
À20 ꢀC (Anal. Calc. for C41H32O4Os2P2Te2: C, 38.28; H,
2.51. Found: C, 34.45; H, 2.76%). IR (mCO, CH2Cl2):
w, 1925 m cmÀ1 1H NMR (CD2Cl2): d 8.07–6.13 (m,
;
24H), 5.14 (dd, 1H, d, J = 10.4, 3.2 Hz), À15.0 (d, J =
18.0 Hz); 31P{1H} NMR(CDCl3): d À18.4 (d, J = 91.4 Hz),
À28.7 (d, J = 91.4 Hz); MS (FAB): m/z 1260 (M+). The
second band gave [Os3(CO)8(l-SPh)2(l-dppm)] 3 Æ H2O Æ
H2S (0.026 g, 21%) as yellow crystals from hexane/CH2Cl2
at À20 ꢀC (Anal. Calc. for C45H36O9Os3P2S3: C, 37.28;
H, 2.50. Found: C, 37.53; H, 2.72%). IR (mCO, CH2Cl2):
1
2016 vs, 1993 s, 1927 m cmÀ1; H NMR(CD2Cl2): d 8.15–
6.98 (m, 30H), 4.77 (m. 1H), 4.58 (m, 1H);31P{1H}
NMR(CD2Cl2): d À20.8 (s); FAB MS: m/z 1288. The third
band afforded [Os3(CO)8(l-TePh)2(l-dppm)] (7) (0.030 g,
23%) as orange crystals after recrystallizaton from hex-
ane/CH2Cl2 at À20 ꢀC (Anal. Calc. for C45H32O8Os3P2Te2:
C, 34.02; H, 2.03. Found: C, 34.41; H, 2.36%). IR (mCO,
2070 s, 2026 m, 1993 vs, 1968 w, 1943 w cmÀ1 1H
;
1
NMR(CD2Cl2): d 7.83–7.05 (m, 30H), 5.03 (m. 1H), 4.65
(m. 1H); 31P{1H} NMR(CD2Cl2): d 17.3 (d, J = 69.8 Hz),
20.8 (d, J = 69.8 Hz); FAB MS: m/z 1398 (M+). The
third band afforded [(l-H)Os3(CO)7(l,g2-SC6H4)(l-SPh)-
(l-dppm)] (4) (0.029 g, 26%) as pale yellow crystal after
recrystallization from hexane/CH2Cl2 at À20 ꢀC. (Anal.
Calc. for C44H32O7Os3P2S2: C, 38.59; H, 2.36. Found: C,
38.83; H, 2.72%). IR (mCO, CH2Cl2): 2056 m, 2041 vs,
CH2Cl2): 2053 s, 2031 s, 1972 s cmÀ1; H NMR(CD2Cl2):
d 7.78–7.18 (m, 30H), 4.35 (m, 2H); 31P{1H} NMR-
(CD2Cl2): d 14.1 (d, J = 81.2 Hz), 4.2 (d, J = 81.2 Hz);
FAB MS: m/z 1590.
4.5. X-ray crystallography for compounds 2, 3, and 7
Intensity data for 3 were obtained using a Bruker Non-
ius Kappa CCD diffractometer using Mo Ka radiation.
1997 w, 1983 s, 1956 w cmÀ1 1H NMR (CD2Cl2): d
;

104
S.E. Kabir et al. / Journal of Organometallic Chemistry 691 (2006) 97–104
[9] T. Akter, N. Begum, A. Yesmin, D.T. Haworth, D.W. Bennett, S.E.
Kabir, Md.A. Miah, N.C. Sarker, T.A. Siddiquee, E. Rosenberg, J.
Organomet. Chem. 689 (2004) 237.
[10] (a) D. Cauzzi, C. Graiff, C. Massera, G. Mori, G. Predieri, A.
Tiripicchio, J. Chem. Soc., Dalton Trans. (1998) 321;
(b) D. Cauzzi, C. Graiff, G. Predieri, A. Tiripicchio, C. Vignali, J.
Chem. Soc., Dalton Trans. (1999) 237.
[11] D. Cauzzi, C. Graiff, G. Predieri, A. Tiripicchio, in: P. Baistrocchi,
L.A. Oro, P.R. Raitby, A. Tiripicchio (Eds.), Metal Clusters in
Chemistry, vol. 1, VCH, Weinheim, 1999, pp. 193–208.
[12] I.D. Sadekov, A.I. Uraev, A.D. Garnovskii, Russ. Chem. Rev. 68
(1999) 415.
Data collection and processing were carried out by using
the programs COLLECT [23] and DENZO [24]. Data were
corrected for absorption effects using SORTAV [25]. Data
for complexes 2 and 7 were obtained on a Bruker
SMART APEX CCD diffractometer using Mo Ka radia-
tion. Data reduction and integration were carried out
with SAINT+ and absorption corrections using SADABS [26].
The structures were solved by direct methods and re-
fined on F2 by full-matrix least squares (SHELXTL PLUS
V6.10) [26] using all unique data. For all structures,
the non-hydrogen atoms were refined anisotropically
and the hydrogen atoms were included in calculated
positions (riding model). The crystal data, details of
data collection and refinement results are summarized
in Table 1.
[13] P.V. Broadhurst, B.F.G. Johnson, J. Lewis, J. Chem. Soc., Dalton
Trans. (1982) 1881.
[14] (a) A.J. Arce, P. Arrojo, Y.De. Sanctis, A.J. Deeming, D.J. West,
Polyhedron 11 (1992) 1013;
(b) A.J. Arce, P. Arrojo, Y.De. Sanctis, A.J. Deeming, J. Chem. Soc.,
Chem. Commun. (1991) 1491.
[15] J. Zhang, W.K. Leong, J. Chem. Soc., Dalton Trans. (2000)
1279.
[16] (a) K.A. Azam, M.B. Hursthouse, Md.R. Islam, S.E. Kabir, K.M.A.
Malik, R. Miah, C. Sudbrake, H. Vahrenkamp, J. Chem. Soc.,
Dalton Trans. (1998) 1097;
Acknowledgments
Part of this work was carried out by SEK at Univer-
sity College London. He gratefully acknowledges the
Royal Society (London) for a fellowship to spend time
at UCL.
(b) J.A. Akter, K.A. Azam, S.E. Kabir, K.M.A. Malik, M.A.
Mottalib, Inorg. Chem. Commun. 3 (2000) 553;
(c) J.A. Clucas, D.F. Foster, M.M. Harding, A.K. Smith, J. Chem.
Soc., Chem. Commun. (1984) 949;
(d) D.F. Foster, J.H. Harrison, B.S. Nicholls, A.K. Smith, J.
Organomet. Chem. 295 (1985) 99;
(e) S. Cartwright, J.A. Clucas, R.H. Dawson, D.F. Foster, M.M.
Harding, A.K. Smith, J. Organomet. Chem. 302 (1986) 403;
(f) S.R. Hodge, B.F.G. Johnson, J. Lewis, P.R. Raithby, J. Chem.
Soc., Dalton Trans. (1987) 931;
Appendix A. Supplementary data
Crystallographic data have been deposited with the
Cambridge Crystallographic Data Centre, CCDC Nos.
278326 for 2, 278327 for 3, and 278328 for 7. Copies of this
information may be obtained free of charge from the
Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ,
UK (fax: +44 1223 336 033, email deposit@ccdc.cam.ac.uk
or WWW: www.ccdc.cam.ac.uk). Supplementary data
associated with this article can be found, in the online ver-
sion, at doi:10.1016/j.jorganchem.2005.08.034.
(g) B.F.G. Johnson, J. Lewis, M. Manari, D. Braga, F. Grepioni, C.
Gradella, J. Chem. Soc., Dalton Trans. (1990) 2683.
[17] K.-L. Lu, H.-J. Chen, P.-Y. Lu, S.-Y. Li, F.-E. Hong, S.-M. Peng,
G.-H. Lee, Organometallics 13 (1994) 585.
[18] S.E. Kabir, Md.A. Miah, N.C. Sarker, G.M.G. Hossain, K.I.
Hardcastle, E. Nordlander, E. Rosenberg, Organometallics 24
(2005) 3315.
[19] S.E. Kabir, N. Begum, Md.M. Hassan, Md.I. Hyder, H. Nur, D.W.
Bennett, T.A. Siddiquee, D.T. Haworth, E. Rosenberg, J. Organo-
met. Chem. 689 (2004) 1569.
[20] D.M.P. Mingos, D.J. Wales, Introduction to Cluster Chemistry,
Prentice-Hall, Englewood Cliffs, NJ, 1990.
References
[1] (a) A. Hill, R. West, Adv. Organomet. Chem. 41 (1997) 243;
(b) R. Philip, G.R. Kumar, P. Mathur, S. Ghose, Opt. Commun. 178
(2000) 469.
[21] S.M.T. Abedin, K.A. Azam, M.B. Hursthouse, S.E. Kabir, K.M.A.
Malik, M.A. Mottalib, E. Rosenberg, J. Cluster Sci. 12 (2001)
5.
[2] P. Braunstein, C. Graiff, C. Massera, G. Predieri, J. Rose, A.
Tiripicchio, Inorg. Chem. 41 (2002) 1372.
[22] K.A. Azam, M.B. Hursthouse, S.E. Kabir, K.M.A. Malik, M.A.
Mottalib, J. Chem. Crystallogr. 29 (1999) 813.
[3] M. Shieh, H.-S. Chen, Y.-W. Lai, Organometallics 23 (2004) 4018.
[4] M.L. Kuhlman, T.B. Rauchfuss, Organometallics 23 (2004) 5085.
[5] M. Shieh, M.-H. Hsu, J. Cluster Sci. 15 (2004) 91.
[6] R.D. Adams, M. Tasi, J. Cluster Sci. 1 (1990) 249.
[7] R.D. Adams, Polyhedron 4 (1985) 2003.
[23] R. Hooft, COLLECT Data Collection Software, Nonius B.V., Delft, The
Netherlands, 1998.
[24] Z. Otwinowski, W. Minor, in: C.W. CarterJr., R.M. Sweet (Eds.),
Macromolecular Crystallography, Academic Press, New York, 1997,
pp. 307–326.
[8] S.E. Kabir, S. Pervin, N.C. Sarker, A. Yesmin, A. Sharmin, T.A.
Siddiquee, D.T. Haworth, D.W. Bennett, K.M.A. Malik, J. Organo-
met. Chem. 681 (2003) 237.
[25] R.H. Blessing, Acta Crystallogr., Sect. A 51 (1995) 33.
[26] SMART and SAINT software for CCD diffractometers, version 6.1,
Bruker AXS, Madison, WI, 2000.