Reactivity of the triruthenium ortho-metalated cluster [Ru3(CO)9{μ3-η1,κ1,κ2-PhP(C6H4)CH2PPh}] with tri(2-thienyl)phosphine and tri(2-furyl)phosphine: Forma

Article abstract of DOI:10.1016/j.jorganchem.2009.06.005

Reaction of [Ru₃(CO)₉{μ₃-η¹,κ¹,κ²-PhP(C₆H₄)CH₂PPh}] (1) with tri(2-thienyl)phosphine (PTh₃) in refluxing THF afforded [Ru₃(CO)₉

Full text of DOI:10.1016/j.jorganchem.2009.06.005

Journal of Organometallic Chemistry 694 (2009) 3312–3319
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Reactivity of the triruthenium ortho-metalated cluster [Ru3(CO)9{l3- , , -
g1 j1 j2
PhP(C6H4)CH2PPh}] with tri(2-thienyl)phosphine and tri(2-furyl)phosphine:
Formation of 1,3-diphenyl-2,3-dihydro-1H-1,3-benzodiphosphine complexes
via phosphorus–carbon bond formation
c,
a,
*
Shishir Ghosh a, Shahed Rana a, Derek A. Tocher b, Graeme Hogarth b, , Ebbe Nordlander , Shariff E. Kabir
*
*
a Department of Chemistry, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh
b Department of Chemistry, University College London, 20 Gordon Street, London WC1H OAJ, UK
c Inorganic Chemistry Research Group, Chemical Physics, Center for Chemistry and Chemical Engineering, Lund University, Box 124, SE-22100 Lund, Sweden
a r t i c l e i n f o
a b s t r a c t
Reaction of [Ru3(CO)9{l3- , ,j
g1 j1
2-PhP(C6H4)CH2PPh}] (1) with tri(2-thienyl)phosphine (PTh3) in reflux-
-dpbm)] (3) {dpbm = PhP(C6H4)(CH2)PPh} and [Ru3(CO)6( -CO)2{
2-Ph2PCH2PPh}] (5) in 18% and 12% yields, respectively, while a similar
reaction with tri(2-furyl)phosphine (PFu3) gave [Ru3(CO)9(PFu3)( -dpbm)] (4) and [Ru3(CO)7(
C4H3O)( -PFu2){l3
2-PhP(C6H4)CH2PPh}] (6) in 24% and 27% yields, respectively. Compounds 2
Article history:
Received 1 May 2009
Received in revised form 2 June 2009
Accepted 4 June 2009
Available online 9 June 2009
ing THF afforded [Ru3(CO)9(PTh3)(
l
l
l-
j1
,
g
1-PTh2(C4H2S)}{l3
-
j1
,j
l
l- , -
g1 g2
l
-
g1
,
j1
,
j
and 4 are phosphine adducts of 1 in which the diphosphine ligand is transformed into 1,3-diphenyl-
2,3-dihydro-1H-1,3-benzodiphosphine (dpbm) via phosphorus–carbon bond formation. Cluster 5 results
from metalation of a thienyl ring, the cleaved proton being transferred to the diphosphine. Carbon–phos-
phorus bond cleavage of a PFu3 ligand is observed in 6 to afford a phosphido-bridge and a furyl fragment,
Keywords:
Diphosphines
Triruthenium
Carbonyl
Tri(2-thienyl)phosphine
Tri(2-furyl)phosphine
X-ray structures
the latter bridging in a
r,
p
-vinyl fashion. The molecular structures of 3, 5 and 6 have been determined by
X-ray diffraction studies.
Ó 2009 Published by Elsevier B.V.
1. Introduction
they are beginning to come under scrutiny. Notably, the coordina-
tion chemistry of diphenyl-1,4-diphospha-cyclohexane (dpdpc) [5]
and 1,2,3,4-tetrahydro-1,4-diphenyl-1,4-benzodiphosphinine (be-
dip) [6] (Chart 1) has recently been documented. Dpdpc has been
shown to act as a versatile ligand, having the ability to vary its hap-
ticity as a function of the charge on the metal center, while com-
plexes of both dpdpc and betip show interesting activity in the
palladium-catalyzed Heck reaction of iodobenzene with styrene
and ethyl acetate [5]. Both of these ligands contain a pair of two-
carbon backbone groups. In contrast, in 1,3-diphenyl-2,3-dihy-
dro-1H-1,3-benzodiphosphine (dpbm) (Chart 1) the phosphorus
atoms are linked by both two- and one-atom spacers [7] which
potentially increases the degree of strain in the ligand. Dpbm can
be prepared upon addition of dichloromethane to Li2[PhP(o-
C6H4)PPh], which in turn is formed from the secondary diphos-
phine, PhP(H)(o-C6H4)P(H)Ph [7,8]. Uncoordinated it is proposed
to exist as a mixture of cis and trans isomers, while when coordi-
nated across a metal–metal bond only the cis-conformation is al-
lowed. This isomerism relates to the stereochemistry at
phosphorus, and thus once coordinated to a metal center it is dia-
stereotopically fixed.
Diphosphines are an important class of ligands that find wide-
spread use in transition metal chemistry and homogeneous catal-
ysis. Consequently a very wide range has been prepared, with
variations to the substituents on phosphorus and the backbone
group leading to the ready tuning of steric and electronic proper-
ties thus allowing highly diphosphine-dependent region- and ste-
reoselectivity in
a range of catalytic transformations. Two
commonly utilized diphosphines are 1,2-bis(diphenylphos-
phino)benzene (dppb) [1] and bis(diphenylphosphino)methane
(dppm) [2] (Chart 1), derivatives of both finding increasing use in
homogeneous catalysis [3,4]. They differ primarily in the bite an-
gles they subtend when metal-bound; the rigid ortho-disubstituted
benzene backbone leading to a significantly increased bite angle as
compared to the simple methylene group.
Like the vast majority of diphosphines studied to date, both
dppm and dppb contain a single backbone unit. In contrast, diphos-
phines containing two linking groups are far less common and
have been sparingly utilized in homogeneous catalysis although
Dpbm can also be prepared on a metal template from relatively
inexpensive dppm. Thus heating [Ru3(CO)10(l-dppm)] [9–11] in
* Corresponding authors. Tel.: +406 243 2592; fax: +406 243 2477.
E-mail address: skabir_ju@yahoo.com (S.E. Kabir).
0022-328X/$ - see front matter Ó 2009 Published by Elsevier B.V.
doi:10.1016/j.jorganchem.2009.06.005

S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
3313
Ph
Ph
Ph
P
P
P
Ph2P
PPh2
P
P
P
Ph2P
PPh2
Ph
Ph
Ph
dppb
dppm
dpbm
dpdpc
bedip
Chart 1.
cyclohexane for 6 h results in elimination of benzene and forma-
tion of [Ru3(CO)9{l3
2-PhP(C6H4)CH2PPh}] (1), a transfor-
mation which is clean and high yielding. Cluster 1 has been
shown to be highly reactive towards a range of unsaturated organ-
ics [12], and pertinently adds CO at elevated temperatures to afford
reactions were carried out under a nitrogen atmosphere using
standard Schlenk techniques. Reagent-grade solvents were dried
by standard methods prior to use. Infrared spectra were recorded
on a Shimadzu FTIR 8101 spectrophotometer. 1H NMR spectra
were recorded on a Bruker DPX 400 spectrometer. Elemental anal-
yses were performed by Microanalytical Laboratories, University
College London.
-
g1 j1
, ,j
[Ru3(CO)10(l-dpbm)] (2) in high yields [9,10], a transformation
which can be reversed upon heating (Scheme 1).
This seemed to us a useful way of preparing a range of dpbm
complexes in a number of simple and high yielding steps. A limita-
tion of 2 is its ready loss of CO and regeneration of 1 via carbon–
phosphorus bond cleavage. We reasoned that the addition of a
tertiary phosphine to 1 would potentially lead to phosphine-
substituted derivatives that were less prone to ligand loss and
hence cleavage of the dpbm ligand. With this in mind and as part
of our study on the reactivity of functionalized phosphines with
transition metal carbonyls, we have examined the reactivity of
tri(2-thienyl)phosphine (PTh3) and tri(2-furyl)phosphine (PFu3)
with 1, the results of which are described herein.
2.1. Reaction of 1 with PTh3
To a THF solution (20 mL) of 1 (100 mg, 0.116 mmol) was added
PTh3 (32 mg, 0.114 mmol) and the reaction mixture was heated to
reflux for 90 min. The solvent was removed by rotary evaporation
and the residue chromatographed by TLC on silica gel. Elution with
hexane/CH2Cl2 (7:3, v/v) developed three bands. The first band was
unreacted 1 (trace). The second band afforded [Ru3(CO)6(
1-PTh2(C4H2S)}{l3 2-Ph2PCH2PPh}] (5) (16 mg, 12%) as or-
ange crystals while the third band gave [Ru3(CO)9(PTh3)( -dpbm)]
l-CO)2{l-
j1
,g
- ,j
j1
l
(3) (23 mg, 18%) as red crystals after recrystallization from hexane/
CH2Cl2 at 4 °C. Spectral data for 3: Anal. Calc. for C40H25O9P3Ru3S3:
2. Experimental
C, 42.07; H, 2.21. Found: C, 42.44; H, 2.28%. IR (
mCO, CH2Cl2):
2058 m, 1998 s, 1978 s, 1942 s cmÀ1 1H NMR (CDCl3): d 7.81(m,
;
Unless otherwise stated all the reactions were performed under
a nitrogen atmosphere using standard Schlenk techniques. Sol-
vents were dried and distilled prior to use by standard methods.
[Ru3(CO)12] was purchased from Strem Chemicals Inc. and used
4H), 7.55(m, 9H), 7.38 (m, 3H), 7.30 (m, 4H), 7.12 (m, 3H), 4.24
(m, 1H), 3.57 (m, 1H); 31P{1H} NMR (CDCl3): d 29.9 (s, 2P), À1.5
(s, 1P). Spectral data for 5: Anal. Calc. for C39H25O8P3Ru3S3: C,
without
further purification and [Ru3(CO)9{l3- , , -
g1 j1 j2
42.05; H, 2.26. Found: C, 42.41; H, 2.32%. IR (
mCO, CH2Cl2): 2040
w, 2027 w, 1990 m, 1968 s, 1943sh cmÀ1 1H NMR (CDCl3): d
;
PhP(C6H4)CH2PPh}] (1) was prepared according to the published
procedures [11]. Bis(diphenylphosphino)methane (dppm), PFu3
and PTh3 were purchased from Merck and used as received. All
7.75 (m, 5H), 7.60 (m, 5H), 7.51–7.21 (m, 6H), 7.20 (m, 4H), 7.16
(m, 1H), 7.09 (m, 1H), 6.90 (m, 1H), 3.81(m, 1H), 3.55 (m, 1H).
Ph
(CO)3
Ph
P
PPh2
(OC)4Ru
Ru
Δ
P
Ru
P
- CO, - C6H6
Ru
Ph2
(CO)3
(CO)3
Ru(CO)3
Ru
(CO)2
C
O
1
Δ
Δ , +CO
(CO)3
Ru
Ph
P
(OC)4Ru
Ru
P
(CO)3
Ph
2
Scheme 1.

3314
S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
31P{1H} NMR (CDCl3): d 33.3 (d, 1P, J = 72.6 Hz), 29.1 (d, 1P,
J = 72.6 Hz), À4.2 (s, 1P).
tion corrections were applied using the program SADABS [13]. Struc-
tures were solved by direct methods and developed using
alternating cycles of least-squares refinement and difference-Fou-
rier synthesis. All non-hydrogen atoms were refined anisotropi-
cally. Hydrogen atoms were placed in the calculated positions
and their thermal parameters linked to those of the atoms to which
they were attached (riding model). The SHELXTL PLUS V6.10 program
package was used for structure solution and refinement [14]. Final
difference maps did not show any residual electron density of ste-
reochemical significance. The details of the data collection and
structure refinement are given in Table 1.
2.2. Reaction of 1 with PFu3
A
similar reaction to that above between 1 (100 mg,
0.116 mmol) and PFu3 (27 mg, 0.116 mmol) in refluxing THF
(20 mL) followed by similar chromatographic separation devel-
oped three bands. The first band was unreacted 1 (trace). The sec-
ond band gave [Ru3(CO)9(PFu3)(
crystals while the third band afforded [Ru3(CO)7(
C4H3O)( -PFu2){l3
2-PhP(C6H4)CH2PPh}] (6) (33 mg, 27%)
l-dpbm)] (4) (30 mg, 24%) as red
l- , -
g1 g2
l
- , ,j
g1 j1
as orange crystals from hexane/CH2Cl2 at 4 °C. Spectral data for
4: Anal. Calc. for C40H25O12P3Ru3: C, 43.93; H, 2.31. Found: C,
3. Results
44.27; H, 2.39%. IR (
mCO, CH2Cl2): 2071 w, 2045 m, 2002 s, 1985
3.1. Synthesis and characterization of dpbm complexes
s, 1953 m cmÀ1 1H NMR (CDCl3): d 7.96 (m, 1H), 7.82 (m, 2H),
;
[Ru3(CO)9{P(C4H3E)3}(
l-dpbm)] (E = S, O)
7.57 (m, 5H), 7.22 (m, 1H), 6.99 (m, 2H), 6.88 (m, 2H), 6.70 (m,
2H), 6.33 (m, 4H), 6.26 (m, 2H), 6.20 (m, 2H), 4.27 (m, 1H), 3.51
(m, 1H); 31P{1H} NMR (CDCl3): d 4.5 (d, 1P, J = 77.2 Hz), À0.5 (d,
1P, J = 77.2 Hz), À17.9 (s, 1P); mass spectrum (FAB): m/z 1093
(M+). Spectral data for 6: Anal. Calc. for C38H25O10P3Ru3: C, 43.98;
Reaction of [Ru3(CO)9{l3
-
g1 j1
, ,j
2-PhP(C6H4)CH2PPh}] (1) with
PTh3 and PFu3 in refluxing THF leads to the isolation of the desired
dpbm complexes [Ru3(CO)9(PTh3)( -dpbm)] (3) and [Ru3(CO)9-
(PFu3)( -dpbm)] (4) in moderate (18% and 24%) yields (Scheme 2).
l
l
H, 2.43. Found: C, 44.34; H, 2.51%. IR (
mCO, CH2Cl2): 2072 s,
Formation of dpbm complexes was shown spectroscopically
with 31P{1H} NMR spectra being particularly informative. For 3 this
consists of two singlets at d 29.9 and À1.5 ppm in a 2:1 ratio being
attributed to the dpbm and PTh3 ligands, respectively. The former
is consistent with the observation of a singlet for 2 at d 28.8 ppm
[9]. The equivalence of the two ends of the dpbm ligand suggests
that in solution the monodentate phosphine is moving rapidly be-
tween the two equatorial sites (Scheme 3), an observation which is
fully consistent with the observed fluxional behavior of related
2038 m, 2012 s, 1954 m, br cmÀ1 1H NMR (CDCl3): d 8.27(m,
;
1H), 7.85(m, 1H), 7.64 (m, 3H), 7.53 (m, 1H), 7.46 (m, 3H), 7.35
(m, 4H), 7.14 (m, 1H), 6.98 (m, 1H), 6.79 (m, 1H), 6.64 (m, 1H),
6.31 (m, 2H), 6.21 (m, 1H), 6.14 (m, 2H), 6.01 (m, 1H), 2.32 (m,
1H), 1.96 (m, 1H); 31P{1H} NMR (CDCl3):
d 68.3 (d, 1P,
J = 30.7 Hz,), 67.0 (d, 1P, J = 81.6 Hz), 0.5 (dd, 1P, J = 81.6, 30.7 Hz).
2.3. X-ray structure determinations
[Ru3(CO)9(PR3)(l
-dppm)] complexes [15]. In contrast, the 31P{1H}
Single crystals of 3, 5 and 6 suitable for X-ray diffraction were
grown by slow diffusion of hexane into a dichloromethane solution
at 4 °C. All geometric and crystallographic data were collected at
150 K (for 3 and 5) and 293 K (for 6) on a Bruker SMART APEX
NMR spectrum of 4 consists of a pair of doublets at d 4.5 and
À0.5 ppm (JPP = 77.2 Hz) assigned to the dpbm ligand and a singlet
at d À17.9 ppm attributed to the PFu3 ligand. This suggests that in
4 movement of the PFu3 ligand is slow on the NMR timescale.
In the aliphatic region of the 1H NMR spectrum, both display
two complex equal intensity multiplets being assigned to the
CCD diffractometer using Mo K
a radiation (k = 0.71073 Å). Data
reduction and integration were carried out with SAINT+ and absorp-
Table 1
Crystallographic data and structure refinement for 3, 5 and 6.
3
5
6
Empirical formula
Formula weight (Å)
Temperature (K)
Crystal system
C40H25O9P3Ru3S3
1141.90
150(2)
C42H39O8P3Ru3S3
1164.03
150(2)
Monoclinic
P21/c
C44H24O10P3Ru3
1108.75
293(2)
Triclinic
Triclinic
Space group
P1
P1
Unit cell dimensions
a (Å)
b (Å)
c (Å)
10.3086(7)
13.6048(10)
16.2662(12)
105.816(1)
107.012(1)
92.232(1)
2081.3(3)
2
11.2555(10)
19.8514(17)
18.6841(16)
90
95.078(2)
90
4158.3(6)
4
1.859
11.6443(11)
12.0494(11)
15.0970(14)
98.961(2)
98.381(1)
100.374(2)
2025.0(3)
2
a
(°)
b (°)
c
(°)
Volume (Å3)
Z
Density (calculated) (Mg/m3)
Absorption coefficient (mmÀ1
F(0 0 0)
1.822
1.395
1124
1.818
1.284
1090
)
1.396
2320
Crystal size (mm)
h Range for data collection (°)
Reflections collected (Rint
0.22 Â 0.18 Â 0.06
2.44–28.27
18 007
0.12 Â 0.04 Â 0.01
1.50–28.25
35 854
0.42 Â 0.22 Â 0.18
1.75–28.30
17 526
)
Independent reflections
9494 (0.0218)
9494/0/523
1.004
9924 (0.0722)
9924/0/521
1.000
9236 (0.0233)
9236/10/682
0.992
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2
r
(I)]
R1 = 0.0343,
wR2 = 0.0981
R1 = 0.0395,
wR2 = 0.1018
1.135 and À1.233
R1 = 0.0537,
wR2 = 0.1155
R1 = 0.0811,
wR2 = 0.1268
2.291 and À0.950
R1 = 0.0501,
wR2 = 0.1436
R1 = 0.0557,
wR2 = 0.1500
1.243 and À2.429
R indices (all data)
Largest difference in peak and hole (e ÅÀ3
)

S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
3315
Ph
P
Ph
P
(CO)3
(CO)3
Ru
Ph
P
(EC4H3)3P
Ru
Ru
Δ , P(C4H3E)3
(CO)3
Ru
(CO)3
P
Ru(CO)3
Ru
(CO)2
C
O
Ph
3 E = S
4 E = O
1
Scheme 2.
inequivalent methylene protons of the backbone. For 3 these ap-
pear at d 4.24 and 3.57 and for 4 at d 4.27 and 3.51. Both also show
parent molecular ions in their FAB mass spectra together with ions
due to sequential loss of all nine carbonyl ligands.
ing the dpbm ligand [Ru(2)–P(2) 2.3197(8) and Ru(3)–P(3)
2.3131(8) Å] are very similar to those observed in both polymorphs
of [Ru3(CO)10(l-dpbm)] [av. Ru–P 2.3215(1) Å] [9,17].
Cluster 3 was also characterized by single crystal X-ray crystal-
lography. An ORTEP diagram of the molecular structure is depicted
in Fig. 1, and selected bond distances and angles are listed in the
caption. The molecule comprises a triangle of ruthenium atoms
with three distinctly different ruthenium–ruthenium bonds;
[Ru(1)–Ru(2) 2.8585(4), Ru(1)–Ru(3) 2.8351(4) and Ru(2)–Ru(3)
2.8868(3) Å]. The PTh3 ligand occupies an equatorial coordination
site on the remote metal, Ru(1), while the dpbm ligand bridges
the Ru(2)–Ru(3) edge and also lies in the equatorial plane. These
features are fully consistent with the observed structures of [Ru3-
3.2. Carbon-element bond cleavage products
In both reactions a second product was isolated (Scheme 4).
With PTh3 this was found to be [Ru3(CO)6(
l-CO)2{l- , -
j1 g1
PTh2(C4H2S)}{l3
-
,j
j1 2-Ph2PCH2PPh}] (5) (12%), which results from
ortho-metalation of a thienyl ring with transfer of the proton to the
ortho-metalated arene ring of 1. With PFu3 the dominant side-reac-
tion was the carbon–phosphorus bond scission of a furyl group
leading to the isolation of [Ru3(CO)7(
l- ,g l-PFu2){l3-
g1 2-C4H3O)(
g1 j1
, ,j
2-PhP(C6H4)CH2PPh}] (6) in 27% yield. Both 5 and 6 are
(CO)9(PR3)(l-dppm)] [12,15–16]. The Ru–P bond distances involv-
formed only in very low yields at room temperature, and it was
found that their yields increase relative to that of dpbm complexes
3 and 4 when the reaction between 1 and PFu3 was carried in
refluxing benzene. Both 5 and 6 were characterized by single crys-
tal X-ray crystallography.
An ORTEP diagram of the molecular structure of 5 is depicted in
Fig. 2, and the caption contains selected bond distances and angles.
The cluster consists of an approximate isosceles triangle of ruthe-
nium atoms [Ru(1)–Ru(2) 2.8468(6), Ru(1)–Ru(3) 2.8857(6) and
Ru(2)–Ru(3) 2.8908(6) Å] coordinated by six terminal CO and
two semi-bridging CO ligands, a
l-Th2PC4H2S ligand and a l3-
Ph2PCH2PPh ligand. The semi-bridging carbonyls span Ru(1)–
Ru(3) and Ru(2)–Ru(3), their asymmetric nature being apparent
from the corresponding ruthenium–carbon distances [Ru(1)–C(8)
2.445(5), Ru(3)–C(8) 1.995(5), Ru(2)–C(7) 2.575(5) and Ru(3)–
C(7) 1.945(6) Å]. The l-Th2PC4H2S ligand bridges the Ru(1)–Ru(3)
CO
CO
Th3P
OC
Th3P
(CO)3
Ru
(CO)3
Ru
edge such that the phosphorus atom is bound to Ru(1) and the
ortho-metalated thienyl ring to Ru(3). The Ru(3)–C(52) distance
of 2.128(5) Å is similar to those observed in related complexes such
Ph
Ph
P
Ru
Ru
P
OC
Ru
(CO)3
P
Ru
(CO)3
P
CO
CO
Ph
Ph
as [Ru3(CO)9(
[Ru3(CO)8(PPh2Th)(
[18]. As far as we are aware, 5 is the first ruthenium complex in
which the PTh3 ligand adopts this type of (
1) coordination
mode. However, this mode of coordination of PTh3 ligand has been
previously observed in the triosmium cluster [Os3(CO)9( -H)-
1-PTh2(C4H2S)}] [19]. The
3-Ph2PCH2PPh ligand is facially
l
-H){l3
-
j1
,
g1
-
,
g
2-Ph2P(C4H2S)}] (2.10(1) Å) and
g1 2-Ph2P(C4H2S)}]
, ,g (2.114(4) Å)
l-H){l3
j1
l- ,g
j1
l
{l
-
j1
,g
l
located on the opposite side of the triruthenium core, such that
one phosphorus is bound to Ru(3) while the other bridges the
Ru(1)–Ru(3) edge. The coordination mode of this fragment is sim-
ilar to that observed in [Ru3(CO)9(
Spectroscopic data for are consistent with the solid-state
l-H){l3- ,j
j1 2-Ph2PCH2PPh}] [9].
Fig. 1. Molecular structure of [Ru3(CO)9(PTh3)(l-dpbm)] (3) showing 50% proba-
5
bility thermal ellipsoids. Hydrogen atoms are omitted for clarity. Selected bond
lengths (Å) and angles (°): Ru(1)–Ru(2) 2.8585(4), Ru(1)–Ru(3) 2.8351(4), Ru(2)–
Ru(3) 2.8868(3), Ru(1)–P(1) 2.3261(8), Ru(2)–P(2) 2.3197(8), Ru(3)–P(3) 2.3131(8),
Ru(3)–Ru(1)–Ru(2) 60.930(8), Ru(1)–Ru(2)–Ru(3) 59.135(9), Ru(1)–Ru(3)–Ru(2)
59.935(9), C(1)–Ru(1)–C(3) 176.52(13), C(2)–Ru(1)–P(1) 101.21(11), C(3)–Ru(1)–
P(1) 92.34(9), P(1)–Ru(1)–Ru(2) 101.90(2), P(1)–Ru(1)–Ru(3) 162.74(2), P(2)–
Ru(2)–Ru(3) 87.40(2), C(5)–Ru(2)–P(2) 108.40(10), P(3)–Ru(3)–Ru(2) 90.22(2),
C(8)–Ru(3)–P(3) 109.17(11), C(22)–P(3)–Ru(3) 109.53(11), C(34)–P(3)–C(22)
92.56(14), C(35)–P(3)–C(22) 106.87(14), C(35)–P(3)–Ru(3) 122.66(11), P(2)–
C(22)–P(3) 98.96(15).
structure. In addition to the aromatic proton resonances for the
diphosphine and thienyl phosphine ligands, the 1H NMR spectrum
exhibits two multiplets at d 3.81 and 3.55, each integrating to 1H,
being attributed to the methylene proton of the diphosphine
ligand. The 31P{1H} NMR spectrum consists of a pair of doublets
(J = 72.6 Hz) at 33.3 and 29.1 ppm assigned to the diphosphine
and a further singlet at À4.2 ppm attributed to the ortho-metalated
trithienylphosphine.

3316
S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
Ph2P
PPh
O
C
PhP
PhP
PFu3
67 oC
(OC)
(CO)
Ru
Ru
(CO)2
PTh3
67 oC
3
(CO)
Ru
Ru
(OC)3
2
1
C
O
Ru
Th
P
Fu
Ru
P
(CO)2
S
Fu
O
Th
6
5
Scheme 4.
Fig. 3. Molecular structure of [Ru3(CO)7(
l-
g1
,
g
2-C4H3O)( g1 j1 j2
l-PFu2){l3- , , -
PhP(C6H4)CH2PPh}] (6) showing 50% probability thermal ellipsoids. Hydrogen
atoms are omitted for clarity. Selected bond lengths (Å) and angles (°): Ru(1)–Ru(2)
3.1181(6), Ru(1)–Ru(3) 3.0914(6), Ru(2)–P(1) 2.3505(11), Ru(3)–P(1) 2.2400(11),
Ru(2)–P(2) 2.3795(11), Ru(1)–P(3) 2.3491(14), Ru(3)?P(3) 2.3673(12), Ru(1)–C(16)
2.259(14), Ru(1)–C(22) 2.175(5), Ru(3)–C(16) 2.265(11), Ru(3)–C(17) 2.569(11),
Ru(3)–Ru(1)–Ru(2) 61.456(12), P(3)–Ru(1)–Ru(3) 49.30(3), P(3)–Ru(1)–Ru(2)
80.10(3), P(1)–Ru(2)–P(2) 90.13(4), P(1)–Ru(2)–Ru(1) 101.00(3), P(2)–Ru(2)–Ru(1)
73.64(3), P(1)–Ru(3)–P(3) 95.87(4), P(1)–Ru(3)–Ru(1) 104.51(3), P(3)–Ru(3)–Ru(1)
48.79(3), Ru(3)–P(1)–Ru(2) 87.42(4), Ru(1)–P(3)–Ru(3) 81.91(4), P(2)–C(20)–P(3)
105.7(2), C(22)–Ru(1)?C(16) 170.5(5), C(2)–Ru(1)–C(22) 91.0(2), C(22)–Ru(1)–
Ru(3) 130.65(13).
Fig. 2. Molecular structure of [Ru3(CO)6(l-CO)2{l- ,g - , -
j1 1-PTh2(C4H2S)}{l3 j1 j2
Ph2PCH2PPh}] (5) showing 50% probability thermal ellipsoids. Hydrogen atoms are
omitted for clarity. Selected bond lengths (Å) and angles (°): Ru(1)–Ru(2) 2.8468(6),
Ru(1)–Ru(3) 2.8857(6), Ru(2)–Ru(3) 2.8908(6), Ru(1)–P(1) 2.3668(14), Ru(1)–P(3)
2.3115(14), Ru(2)–P(3) 2.3168(14), Ru(3)–P(2) 2.3841(14), Ru(3)–C(52) 2.128(5),
Ru(1)–C(8) 2.445(5), Ru(3)–C(8) 1.995(5), Ru(2)–C(7) 2.575(5), Ru(3)–C(7) 1.945(6),
Ru(2)–Ru(1)–Ru(3) 60.562(14), Ru(1)–Ru(2)–Ru(3) 60.384(15), Ru(1)–Ru(3)–Ru(2)
59.054(14), P(3)–Ru(1)?Ru(2) 52.13(3), P(1)–Ru(1)–Ru(3) 87.84(3), P(3)–Ru(2)–
Ru(1) 51.96(3), C(52)–Ru(3)–P(2) 174.76(14), P(2)–Ru(3)–Ru(1) 91.41(3), C(52)–
Ru(3)–Ru(2) 90.10(13), Ru(1)–P(3)–Ru(2) 75.92(4), Ru(3)–C(8)–Ru(1) 80.37(18),
Ru(3)–C(7)–Ru(2) 78.15(18), O(8)–C(8)–Ru(3) 153.9(4), O(8)–C(8)–Ru(1) 125.6(4),
O(7)–C(7)–Ru(3) 159.5(5), O(7)–C(7)–Ru(2) 121.8(4), P(2)–C(10)–P(3) 105.7(3).
gand [20,21]. The furyl bridge spans across the Ru(1)–Ru(3) edge in
a
r,p-vinyl fashion being bound to Ru(1) via a r-bond. The Ru(1)–
Ru(2) edge [3.1181(6) Å], bridged by the PhPC6H4 moiety of the
diphosphine, is longer than the Ru(1)–Ru(3) edge [3.0914(6) Å]
which is simultaneously bridged by furyl and phosphido bridges.
Spectroscopic data are consistent with the solid-state structure.
The 1H NMR spectrum shows multiplets at d 2.32 and 1.96 as-
signed to the methylene proton of the diphosphine and the
31P{1H} NMR spectrum shows two doublets of doublets at d 68.3
and 67.0 ppm and a further doublet at d 0.5 ppm, each integrating
to one phosphorus.
An ORTEP diagram of the molecular structure of 6 is shown in
Fig. 3, and selected bond distances and angles are listed in the cap-
tion. The molecule contains an open triangle of ruthenium atoms
capped by
a l3-PhP(C6H4)CH2PPh ligand and bridging di(2-
furyl)phosphide and furyl groups. The diphosphine bridges all
ruthenium atoms in a similar fashion to that observed in 1; that
is Ru(2) is bonded to one phosphorus atom while the other is
bonded to Ru(3) and this phosphorus atom together with the
C(22) carbon of the C6H4 moiety are bonded to Ru(1). The Ru–C
[2.175(5) Å] and average Ru–P [av. 2.3653(12) Å] distances are also
similar to those in 1. The open edge of the metal triangle is asym-
metrically bridged by a di(2-furyl)phosphide ligand, bond angles
and distances being similar to those found in other open triruthe-
nium clusters in which the open edge is bridged by a phosphido li-
4. Discussion
Few reactivity studies have been carried out directly on [Ru3-
(CO)9{l3
been implicated in thermal reactions of [Ru3(CO)10
- , ,j
g1 j1 2-PhP(C6H4)CH2PPh}] (1) [9,10] although it has
(l-dppm)]
[12]. Bonnet and co-workers [9] have shown that formation of 2
upon carbonylation of 1 proceeds via the initial addition of CO to
the cluster with concomitant ruthenium–ruthenium bond cleavage

S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
3317
to afford [Ru3(CO)10
{
l3
-
g1
,
j1
,
j
2-PhP(C6H4)CH2PPh}] (7) which has
Aspects of our recent work on a comparative study of the reac-
tivity of [Ru3(CO)10 -dppm)] with PTh3 and PFu3 shed some light
on these secondary processes. Thus, while in each case the simple
substitution products, [Ru3(CO)9{P(C4H3E)3}( -dppm)], are initially
been crystallographically characterized (Scheme 5). Likewise, addi-
tion of PPh3 at 0 °C has been shown to initially afford 8 resulting
from phosphine addition and ruthenium–ruthenium bond scission
[10]. Addition of further phosphine and warming to room temper-
ature result in further metal–metal bond scission to afford binu-
clear 9 and mononuclear [Ru(CO)3(PPh3)2] [22]. In previous work
we have characterized cluster 10 (Scheme 5) which results from
addition of two equivalents of phosphine [21]. Here both phospho-
rus–hydrogen bonds have been activated leading to the formation
of a hydride and transfer of a second proton to the ortho-metalated
ring. Unfortunately, we carried out this reaction at elevated tem-
perature (80 °C) and we were therefore unable to identify any
intermediates. Nevertheless it seems likely that the reaction pro-
ceeds in an analogous fashion to that with PPh3, initial addition
leading to ruthenium–ruthenium bond scission followed by later
addition of the phosphorus–hydrogen bonds. Given that we did
not isolate [Ru(CO)3(Ph2PH)2] [23] from this reaction we believe
that the first phosphorus–hydrogen additions occur prior to addi-
tion of the second equivalent of phosphine.
(l
l
formed, upon mild heating they undergo both carbon–phosphorus
and carbon–hydrogen bond cleavage to afford thiophyne and fur-
yne clusters [Ru3(CO)7(l-dppm)(l3-g l-P(C4H3E)2}(l-
2-C4H2E){
H)] (Scheme 7) [20]. This provides evidence for both the facile car-
bon–hydrogen and carbon–phosphorus activation of the coordi-
nated ligands.
In the work described herein the coordinated PTh3 and PFu3 li-
gands undergo different thermal activation pathways. Again, this is
not surprising in light of the established sensitivity of phosphorus–
carbon bond cleavage reactions to changes in the substituents on
carbon [24]. In recent work focused on their thermal rearrange-
ment when bound to dirhenium and dimanganese centers such
behavior has been noted, with PTh3 generally showing a greater
propensity to undergo carbon–phosphorus bond cleavage than
PFu3 [25,26]. It is noteworthy that when these ligands are bound
to the triruthenium framework this trend appears to be reversed.
Another explanation is that in each case both carbon–hydrogen
and carbon–phosphorus bond activation occurs and the selectivity
we observe in product isolation simply reflects the thermodynamic
stability of the products generated from these two different
transformations.
On the basis of the chemistry discussed above we propose a
plausible mechanism for the formation of clusters 3–6 (Scheme
6). Initial phosphine addition is expected to afford open 50-electron
clusters [Ru3(CO)9{P(C4H3E)3}{l3- , ,j
g1 j1 2-PhP(C6H4)CH2PPh}] (A).
These can then rearrange via carbon–phosphorus and ruthenium–
ruthenium bond formation to give the isomeric dpbm complexes
3 and 4 which we isolated in moderate yields. We have not been
able to ascertain whether this transformation is reversible. Compet-
ing pathways to the thermal rearrangement of A presumably exist.
For PTh3 this apparently involves carbonyl loss and ortho-metala-
tion of one of the thienyl groups, possibly proceeding via a bridging
hydride intermediate (shown), followed by transfer of this proton
to the ortho-metalated arene ring of the diphosphine ligand to af-
ford the observed product 5. In contrast, for PFu3 the competing
process is carbon–phosphorus bond scission together with loss of
two carbonyls leading to the generation of 6 which contains phos-
phido and furyl bridges.
5. Conclusions
In summary, the reaction of 1 with PTh3 and PFu3 at 68 °C leads
to the desired 1,3-diphenyl-2,3-dihydro-1H-1,3-benzodiphosphine
(dpbm) compounds [Ru3(CO)9(PTh3)(
l-dpbm)] (3) and [Ru3-
(CO)9(PFu3)( -dpbm)] (4), formed as a result of phosphorus–car-
l
bon bond formation, albeit in moderate yields. The latter may be
due to competing transformations of the non-innocent added
phosphines since secondary products are [Ru3(CO)6(
1-PTh2(C4H2S)}{l3 2-Ph2PCH2PPh}] (5), resulting from car-
bon–hydrogen migration from the monodentate to bidentate phos-
l-CO)2{l-
j1
,g
- ,j
j1
Ph
P
Ph
P
Ph
(CO)3
Ru
Ph
Ph
(OC)4Ru
P
P
P
Δ , +CO
+ CO
- CO
Ru
P
Ru
Ru
(CO)3
(CO)3
C
(CO)3
Δ
Ph
Ru(CO)3
Ru
(CO)2
Ru(CO)4
Ru
Ru
(CO)3
2
7
O
1
PPh3
Ph
Ph
P
P
- 3 CO
2 Ph2PH
Ph2P
Ru
PPh3
(CO)3
Ru
(CO)3
(CO)3
8
PPh3
- [Ru(CO)3(PPh3)2]
PPh
Ru(CO)2
PPh2
H
Ru
(CO)2
Ru
Ph2P
Ph
(CO)2
Ph
P
P
10
Ru
Ru(CO)3
(CO)3
9
Scheme 5.

3318
S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
Ph
P
Ph
Ph
(CO)3
(EC4H3)3P Ru
(CO)3
Ru
Ph
P
Ph
P
P
P
P(C4H3E)3
E = S
Ru
P
Ph
Ru
Ru
P(C4H3E)3
(CO)3
(CO)3
C
(CO)3
Ru(CO)3
(CO)2Ru
Ru
P-C formation
Ru
(CO)3
(CO)3
3-4
O
A
1
- 2CO
E = O
P-C activation
- CO
C-H activation
Ph
P
Ph
P
Ph
P
Ph
P
Ru
(CO)3
PFu2
Ru
(CO)3
Ru
Ru
(CO)3
(CO)2
H
Ru
(CO)3
PTh2
Ru
(CO)2
S
O
C-H formation
6
Ph2P
PPh
O
C
Ru
Ru(CO)2
(CO)2
Ru (CO)2
PTh2
C
O
S
5
Scheme 6.
Acknowledgement
E
PPh2
Ru(CO)3
P(C4H3E)3
Ph2P
(CO)3Ru
(C4H3E)
2 P
40oC
- 2 CO
Financial support of this work by the University Grants Com-
mission of Bangladesh is gratefully acknowledged.
(CO)2
Ru
PPh2
Ru
(CO)3
Ru
Ru
P
(CO)2
E = S, O
(CO)3
Ph2
References
H
[1] (a) See for example, H. McFarlane, E. Christina, W. McFarlane, Polyhedron 18
(1999) 2117;
Scheme 7.
(b) F.B. McCormick, D.D. Cox, W.B. Gleason, Organometallics 12 (1993) 610;
(c) K. Mashima, N. Komura, T. Yamagata, K. Tani, M. Haga, Inorg. Chem. 36
(1997) 2908;
(d) S.J.A. Pope, G. Reid, Dalton Trans. (1999) 1615;
(e) L.-C. Song, J.-T. Liu, Q.-M. Hu, L.-H. Weng, Organometallics 19 (2000) 643;
(f) E. Szlyk, R. Kucharek, I. Szymanska, L. Pazderski, Polyhedron 22 (2003)
3389.
phine,
and
[Ru3(CO)7(l- ,g l-PFu2){l3- , , -
g1 2-C4H3O)( g1 j1 j2
PhP(C6H4)CH2PPh}] (6) formed via carbon–phosphorus bond cleav-
age. In an attempt to cleave a carbon–phosphorus bond of the PTh3
ligand, we also conducted the reaction with 1 at 98 °C but this gave
non-specific decomposition. The phosphine addition products 3
and 4 do not convert into the corresponding carbon–hydrogen
and carbon–phosphorus bond activated products 5 and 6 upon fur-
ther heating which suggests that these products are formed by dif-
ferent pathways. We propose that they share
intermediate, namely the 50-electron clusters [Ru3(CO)9{P-
(C4H3E)3}{l3
2-PhP(C6H4)CH2PPh}] (A) (Scheme 5) and this
[2] (a) See for example, R.J. Puddpehatt, Chem. Soc. Rev. (1983) 99;
(b) B. Chaudret, B. Delavaux, R. Poilblanc, Coord. Chem. Rev. 86 (1988) 134;
(c) G.K. Anderson, Adv. Organomet. Chem. 35 (1993) 1.
[3] (a) See for example, R.B. Bedford, M. Huwe, M.C. Wilkinson, Chem. Commun.
(2009) 600;
(b) M. Arisawa, T. Suzuki, T. Ishikawa, M. Yamaguchi, J. Am. Chem. Soc. 130
(2008) 12214;
(c) G. Hilt, W. Hess, K. Harms, Synthesis (2008) 75;
(d) M. Fabbian, N. Marsich, E. Farnetti, Inorg. Chim. Acta 357 (2004)
2881;
a common
-
g1 j1
, ,j
(e) D.A. Culkin, J.F. Hartwig, J. Am. Chem. Soc. 124 (2002) 9330;
(f) J. Ledford, C.S. Shultz, D.P. Gates, Organometallics 20 (2001) 5266.
[4] (a) See for example, S.J. Dossett, A. Gillon, A.G. Orpen, J.S. Fleming, P.G. Pringle,
D.F. Wass, M.D. Jones, Chem. Commun. (2001) 699;
(b) N.A. Cooley, S.M. Green, D.F. Wass, K. Heslop, A.G. Orpen, P.G. Pringle,
Organometallics 20 (2001) 4769;
is supported by previous work by Bonett and co-workers [9,10].
We are currently investigating the reactivity of 1 towards a range
of mono- and bidentate phosphines in an attempt to find a high-
yielding route to the metal-based formation of the dpbm ligand.
(c) A. Carter, S.A. Cohen, N.A. Cooley, A. Murphy, J. Scutt, D.F. Wass, Chem.
Commun. (2002) 858;
(d) J.N.L. Dennett, A.L. Gillon, K. Heslop, D.J. Hyett, J.S. Fleming, C.E. Lloyd-
Jones, A.G. Orpen, P.G. Pringle, D.F. Wass, J.N. Scutt, R.H. Weatherhaed,
Organometallics 26 (2004) 6077;
(e) T. Agapie, S.J. Schofer, J.A. Labinger, J.E. Bercaw, J. Am. Chem. Soc. 126
(2004) 1304;
(f) K. Blann, A. Bollmann, J.T. Dixon, F.M. Hess, E. Killian, H. Maumela, D.H.
Morgan, A. Neveling, S. Otto, Chem. Commun. (2005) 620;
Supplementary material
CCDC 729872, 729873 and 729871 contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.

S. Ghosh et al. / Journal of Organometallic Chemistry 694 (2009) 3312–3319
3319
(g) M.J. Overett, K. Blann, A. Bollmann, J.T. Dixon, F. Hess, E. Killian, H.
Maumela, D.H. Morgan, A. Neveling, S. Otto, Chem. Commun. (2005) 622;
(h) A. Bollmann, K. Blann, J.T. Dixon, F.M. Hess, E. Killian, H. Maumela, D.S.
McGuiness, D.H. Morgan, A. Neveling, S. Otto, M. Overett, A.M.Z. Slawin, P.
Wasserscheid, S. Kuhlmann, J. Am. Chem. Soc. 126 (2004) 14712;
(i) G. Hoge, H.-P. Wu, W.S. Kissel, D.A. Pflum, D.J. Greene, J. Bao, J. Am. Chem.
Soc. 126 (2004) 5966;
[13] SMART and SAINT Software for CCD Diffractometers, Version 6.1, Madison, WI,
2000.
[14] G.M. Sheldrick, SHELXTL PLUS, Version 6.1, Bruker AXS, Madison, W1, 2000.
[15] A.A. Torabi, A.S. Humphreys, G.A. Koutsantonis, B.W. Skelton, A.H. White, J.
Organomet. Chem. 655 (2002) 227.
[16] L. Viau, A.C. Willis, M.G. Humphrey, J. Organomet. Chem. 692 (2007) 2086.
[17] S.E. Kabir, Md.R. Hassan, D.T. Haworth, S.V. Lindeman, T.A. Siddiquee, D.W.
Bennett, J. Organomet. Chem. 692 (2007) 3936.
(j) H.-P. Wu, G. Hoge, Org. Lett. 6 (2004) 3645;
(k) S.M. Hansen, F. Rominger, M. Metz, P. Hofmann, Chem. Eur. J. 5 (1999) 557;
(l) P. Hofmann, C. Meier, W. Hiller, M. Heckel, J. Riede, M.U. Schmidt, J.
Organomet. Chem. 490 (1995) 51;
(m) J.V. Barkley, M. Ellis, S.J. Higgins, M.K. McCart, Organometallics 17 (1998)
1725;
[18] A.J. Deeming, S.N. Jaysuriya, A.J. Arce, Y.De. Sanctis, Organometallics 15 (1996)
786.
[19] M.A. Mottalib, S.E. Kabir, D.A. Tocher, A.J. Deeming, E. Nordlander, J.
Organomet. Chem. 692 (2007) 5007.
[20] M.N. Uddin, N. Begum, M.R. Hassan, G. Hogarth, S.E. Kabir, M. A Miah, E.
Nordlander, D.A. Tocher, Dalton Trans. (2008) 6219.
[21] Md.I. Hyder, S.E. Kabir, M.A. Miah, T.A. Siddique, G.M.G. Hossain, Polyhedron
24 (2005) 1471.
[22] (a) J.P. Collman, W.P. Roper, J. Am. Chem. Soc. 87 (1965) 4008;
(b) A.F. Hill, Angew. Chem., Int. Ed. Engl. 39 (2000) 130.
[23] C. Babij, L. Chen, I.O. Koshevoy, A.J. Poë, Dalton Trans. (2004) 833.
[24] P.E. Garrou, Chem. Rev. 85 (1985) 171.
[25] M.N. Uddin, M.A. Mottalib, N. Begum, S. Ghosh, A.K. Raha, D.T. Haworth, S.V.
Lindeman, T.A. Siddiquee, D.W. Bennett, G. Hogarth, E. Nordlander, S.E. Kabir,
Organometallics 28 (2009) 1514.
[26] S. Ghosh, M. Khatun, D.T. Haworth, S.V. Lindeman, T.A. Siddiquee, D.W.
Bennett, G. Hogarth, E. Nordlander, S.E. Kabir, J. Organomet. Chem. 694 (2009)
2941.
(n) J.V. Barkley, J.C. Grimshaw, S.J. Higgins, P.B. Hoare, M.K. McCart, A.K. Smith,
J. Chem. Soc., Dalton Trans. (1995) 2901.
[5] M.E. Cucciolito, V. De Felice, I. Orabona, A. Panunzi, F. Ruffo, Inorg. Chim. Acta
343 (2003) 209.
[6] V. De Felice, N. Fraldi, G. Roviello, F. Ruffo, A. Tuzi, J. Organomet. Chem. 692
(2007) 5211.
[7] F.G. Mann, A.J.H. Mercer, J. Chem. Soc., Perkin I (1972) 2548.
[8] N. Maigrot, C. Charrier, L. Ricard, F. Mathey, Bull. Soc. Chim. Fr. 134 (1997) 853.
[9] N. Lugan, J.-J. Bonnet, J.A. Ibers, J. Am. Chem. Soc. 107 (1985) 4484.
[10] N. Lugan, J.-J. Bonnet, J.A. Ibers, Organometallics 7 (1988) 1538.
[11] M.I. Bruce, B.K. Nicholson, M.L. Williams, Inorg. Synth. 26 (1990) 265.
[12] G. Hogarth, S.E. Kabir, Coord. Chem. Rev. 253 (2009) 1285.