Syntheses, structure characterisation and X-ray structures of the complexes Ru3(CO)11L [L = Ph2P(C6H 4Me-p), Ph2PC6F5, P(C 6H4Cl-p)3,

Article abstract of DOI:10.1016/j.poly.2010.06.013

Five trinuclear monosubstituted complexes of the type Ru ₃(CO)₁₁L were synthesised by the reaction of Ru ₃(CO)₁₂ with phosphine ligands (L) using the radical anion catalysed method. The structures of the resulti

Full text of DOI:10.1016/j.poly.2010.06.013

Polyhedron 29 (2010) 2667–2673
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Polyhedron
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Syntheses, structure characterisation and X-ray structures of the complexes
Ru3(CO)11L [L = Ph2P(C6H4Me-p), Ph2PC6F5, P(C6H4Cl-p)3, P(3,5-CF3–C6H3)3
and P(C6H4Me-p)3]
a
b
b
Omar bin Shawkataly a, , Mohd. Aslam A. Pankhi , Hoong-Kun Fun , Chin Sing Yeap
*
a Chemical Sciences Programme, School of Distance Education, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
b X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
a r t i c l e i n f o
a b s t r a c t
Article history:
Five trinuclear monosubstituted complexes of the type Ru3(CO)11L were synthesised by the reaction of
Ru3(CO)12 with phosphine ligands (L) using the radical anion catalysed method. The structures of the
resulting clusters were elucidated by means of elemental analyses and spectroscopic methods, including
IR, 1H NMR, 13C NMR and 31P NMR spectroscopy. 31P NMR spectra of the complexes Ru3(CO)11P(C6H4Me-
p)3 and Ru3(CO)11P(C6H4Cl-p)3 showed splitting of the phosphorus signals into triplets. X-ray crystallo-
graphic studies of all five complexes were carried out. Out of the three unidentate tertiary phosphine
complexes, Ru3(CO)11P(C6H4Me-p)3 and Ru3(CO)11P(C6H4Cl-p)3 are ordered while the complex
Ru3(CO)11P(3,5-CF3–C6H3)3 exhibits disorder with respect to the trifluoromethyl groups.
In all the five monosubstituted complexes, the ligand occupies the equatorial position due to steric rea-
sons and coordination of the ligands are only at the phosphorus atom. The effect of substitution resulted
in significant differences in the Ru–Ru distances. Out of the three Ru–Ru bonds, the one which is cis to the
ligand is noticeably longer and the mean value for this longest Ru–Ru bond is 2.889 Å, while the mean
value for the two shorter Ru–Ru bonds is 2.841 Å. The P–C distances are in the range 2.333(6)–
2.354(6) Å. The equatorial Ru–CO moieties are almost linear and the average value for all the five com-
plexes studied range from 176.3 to 177.6°, while the axial CO groups are slightly bent, ranging from
173.8 to 174.1°.
Received 9 March 2010
Accepted 11 June 2010
Available online 30 June 2010
Keywords:
Ruthenium
Cluster
Carbonyl
Phosphines
X-ray diffraction
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
monosubstituted complexes of Os3(CO)12 by the reaction of Os3
(CO)11(CH3CN) with PR3 [3,4]. Other methods to synthesise this
The syntheses and crystallographic structures of substituted tri-
angular triruthenium clusters have been of interest to researchers
due to their structural variation and catalytic activity [1]. It is
known that the usual product of the reaction between Ru3(CO)12
and tertiary phosphines, PR3, is the tri-substituted complex Ru3
(CO)9(PR3)3; mono- and di-substituted complexes have been ob-
tained earlier only under special conditions, such as under CO, or
as by-products from reactions designed to afford other products.
An earlier method reported by Bruce et al. was the displacement
method whereby the complex Ru3(CO)11(CNBut) was made to react
with CO or a ligand containing P, As or Sb as the donor element, by
displacing CO or CNBut [2]. This method resulted in products with
poor yields as by-products are also formed, though the usefulness
of this process has been successfully demonstrated for synthesising
type of complex are the amine oxide/MeCN method [5] and also
salts of the bis(triphenylphosphine) iminium ion, PPN+ [6]. How-
ever, we prefer the radical anion method, as developed by Bruce
et al., to synthesise derivatives of the type Ru3(CO)12ꢀnLn [n = 1–
4], substituted by tertiary phosphines, phosphites, arsines and iso-
cyanides [7,8a,b]. Substitution of CO by a more bulky ligand results
in the latter ligand occupying the sterically least demanding site,
which in all the cases is the equatorial site.
Many monosubstituted complexes have been synthesised in the
past using the radical anion method, but few have been crystallo-
graphically studied. Specially, for complexes of Ru3(CO)12 with li-
gands of the type Ph2PR (monosubstituted diphenylphosphine),
only three complexes have been crystallographically characterised
[9–11]. Phosphine ligands have found extensive use in the formation
of many complexes of ruthenium over the years. Recently the reac-
tion of Ru3(CO)12 with tris(2-furyl) phosphine has been investigated
[12a]. The same author also mentions the reaction of Ru3(CO)12 with
tris(2-thienyl) phosphine via electron transfer catalysis conditions,
which resulted in mono-, di- and tri-substituted derivatives [12b].
* Corresponding author. Address: Multimedia University, Melaka Campus, Jalan
Ayer Keroh Lama, 74750 Melaka, Malaysia. Tel.: +60 4 653 3936; fax: +60 4 657
6000.
E-mail address: omarsa@usm.my (O.b. Shawkataly).
0277-5387/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2010.06.013

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O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
Besides the monosubstituted complexes reported in this paper, di-
and tri-substituted complexes (of the type Ru3(CO)10L2 and Ru3
(CO)9L3, respectively) have also been synthesised by us and their
structures crystallographically studied, which will be communi-
cated later [13]. To further our interest on substituted triangle triru-
thenium clusters, we report the syntheses, characterisation of
Ru3(CO)11L [L = Ph2P(C6H4Me-p) 1a, Ph2PC6F5 1b, P(C6H4Cl-p)3 1c,
P(3,5-CF3–C6H3)3 1d, P(C6H4Me-p)3 1e, PhP(C6H4OCH3-p)2 1f]. How-
ever whilst X-ray studies of five complexes, 1a–e, have been carried
out, 1f was excluded as it was not possible to obtain single crystals
suitable for XRD studies. The synthesis of 1e has been reported ear-
lier [2], but X-ray diffraction studies have been carried out in this pa-
per along with spectral studies, especially 31P NMR.
and warmed to 40 °C to dissolve the Ru3(CO)12. Sodium benzophe-
none ketyl solution (five drops) was added via syringe, which was
followed immediately by a darkening of the reaction solution (red).
After TLC showed completion of the reaction, the solvent was re-
moved under reduced pressure to give a red residue. Thin layer
chromatography showed the presence of two spots, one of them
being the starting material Ru3(CO)12 in traces. This was identified
by its IR
m (CO) spectrum with that of an authentic sample. The ma-
jor orange band was separated by column chromatography and
characterised.
2.2.2. Synthesis of undecacarbonyl (p-tolyldiphenylphosphino)
triruthenium 1a
The effect of substitution on the triruthenium cluster manifests
itself in many ways, with the decrease in the molecular symmetry.
Introduction of a non-CO ligand, in general, to Ru3(CO)12 results in
a lengthening of the Ru–Ru bond. A trend has been reasonably well
observed in all the substituted complexes (1a–e). In the light of
Ru3(CO)12 (100.0 mg, 0.156 mmol) and Ph2P(C6H4Me-p)
(45.4 mg, 0.164 mmol) in 10 ml dry deoxygenated THF were
heated in an oil bath and warmed to 40 °C to dissolve the
Ru3(CO)12. Sodium benzophenone ketyl solution (five drops) was
added dropwise via a syringe, which immediately changed the
reaction solution to red. After TLC showed completion of the reac-
tion, the solvent was removed under reduced pressure to give an
oily mass. Thin layer chromatography showed the presence of
other published reports on monosubstituted clusters of Ru3(CO)12
,
this study enabled us to make a more extensive comparison on the
changes in the molecular geometries resulting from substitution of
CO by different ligands. The monosubstituted clusters, which have
been synthesised in good yield, will also make interesting precur-
sors for a range of mixed-ligand complexes and other disubstituted
complexes.
three spots including traces of the starting material Ru3(CO)12
,
identified by its TLC and IR (CO) spectrum with that of an authen-
m
tic sample. The major orange band was separated by column chro-
matography (dichloromethane and hexane) and characterised.
Yield: 88.8 mg (64%), m.p. 148–150 °C.
Elemental Anal. Calc. for Ru3C30H17O11P: C, 40.59; H, 1.25. Found:
2. Experimental
C, 40.57; H, 1.26%. IR (cyclohexane),
2015vs, 1988m cmꢀ1 1H NMR (CDCl3) d 2.40 (s, 3H, CH3), 7.23–
7.50 (m, 14H, Ph). 13C NMR (CDCl3) d 21.6 (CH3), 128.9–135.9 (m,
Ph), 204.6 (m, CO). 31P NMR (CDCl3)
35.50–35.54 (d,
m (CO) 2097m, 2058w, 2045s,
.
2.1. Chemicals, starting materials and spectroscopic measurements
d
All the syntheses were carried out using standard Schlenk tech-
niques under an atmosphere of nitrogen. Ru3(CO)12 (Aldrich),
Ph2P(C6H4Me-p) (Pressure Chemical Co., USA), Ph2PC6F5, P(3,5-
CF3–C6H3)3, P(C6H4Cl-p)3, P(C6H4Me-p)3 and PhP(C6H4OCH3-p)2
(Maybridge Chemical Co., Ltd., UK) were used as received. Tetrahy-
drofuran was distilled from sodium benzophenone ketyl under a dry
oxygen-free nitrogen atmosphere. The radical anion method was
used for the syntheses of the complexes [14]. AR grade solvents were
used for crystallisation. Florisil (100–200 mesh, Acros) was used as
the stationary phase for column chromatography. Preparative TLC
was carried out on glass plates 20 ꢁ 20 cm using Silica gel 60GF254
(Merck). Hexane and dichloromethane of AR grades were used for
elution during the column chromatography and preparative TLC.
Elemental analyses were performed using a Perkin–Elmer model
2400 LS Series II C, H, N analyser equipment, USA. The melting points
of the compounds were recorded in open capillaries using an SMP1
melting point apparatus, UK and were uncorrected. IR spectra were
recorded with a Perkin–Elmer System 2000 FTIR spectrometer in a
NaCl solution cell (0.1 mm). Deuterated chloroform was used as a
solvent for 1H NMR, 13C NMR and 31P NMR spectra. These NMR stud-
ies were carried out on Bruker B2H 400 FT-NMR spectrometer using
5 mm tubes. The 1H NMR and 13C NMR shifts were referenced to
TMS and 31P NMR shifts were referenced to 85% H3PO4.
Ph2PC6H4Me-p). Crystals suitable for X-ray crystallography were
grown by slow evaporation of a n-hexane solution at 10 °C.
A third band (red), which was more polar than the major orange
band, could not be separated by column chromatography. However,
thin layer chromatography showed the compound to be Ru3(CO)10
-
(Ph2PC6H4Me-p)2. Another complex was synthesised by the reaction
of Ru3(CO)12 and Ph2P(C6H4Me-p) in a 1:2 molar ratio in THF at 40 °C.
Preparative TLC showed two bands including a small amount of
Ru3(CO)11Ph2P(C6H4Me-p) [Rf = 0.54], identified by its IR and TLC
with 1a. The major red band was separated; hexane:dichloro-
methane; 80:20; Rf = 0.40. IR (cyclohexane) showed the absence of
a band at 2097 cmꢀ1, but exhibited a band at 2075 cmꢀ1, indicative
of the disubstituted Ru3(CO)10[Ph2P(C6H4Me-p)]2. Attempts to grow
suitable single crystals of this compound for XRD studies were not
successful. Yield: 72.0 mg (50%). Elemental Anal. Calc. for Ru3-
C48H34O10P2: C, 50.75; H, 3.02. Found: C, 50.70; H, 3.05%. IR (cyclo-
hexane),
m .
(CO) 2075m, 2059s, 2042m, 2019s, 1990s cmꢀ1 1H
NMR (CDCl3) d 2.40 (s, 6H, CH3), 7.22–7.51 (m, 28H, Ph). 13C NMR
(CDCl3) d 21.4 (–CH3), 129.0–137.4 (m, Ph), 141.9 (C–CH3), 204.6
(m, CO).
2.2.3. Undecacarbonyl (diphenyl pentafluorophenyl phosphino)
triruthenium 1b
Compounds 1a–e were prepared in high yield by an electron
transfer catalysed reaction between Ru3(CO)12 and a stoichiometric
amount of the appropriate ligand. The resulting complexes were
separated by means of column chromatography and then isolated
in the pure form. Complexes 1a–f were characterised by elemental
microanalyses and their spectral studies.
Yield: 93.4 mg (62%), m.p. 127–129 °C. Elemental Anal. Calc. for
Ru3C29H10O11F5P: C, 36.14; H, 1.04. Found: C, 36.11; H, 1.06%. IR
(cyclohexane),
m .
(CO) 2101m, 2050m, 2030m, 2019s, 1989m cmꢀ1
1H NMR (CDCl3) d7.35–7.70 (m, 10H, Ph). 13C NMR (CDCl3) d128.2–
132.2 (m, Ph), 202.8 (m, CO). 31P NMR (CDCl3) d 28.6 (s, Ph2PC6F5).
Crystals suitable for X-ray crystallography were grown by slow
evaporation of a n-hexane solution at 10 °C.
2.2. Synthesis of the metal complexes
2.2.4. Undecacarbonyl (tris-p-chlorophenylphosphino) triruthenium
1c
Yield: 99.3 mg (65%), m.p. 156–158 °C. Elemental Anal. Calc. for
Ru3C29H12O11Cl3P: C, 35.65; H, 1.23. Found: C, 35.61; H, 1.22%. IR
2.2.1. General procedure for the synthesis of complexes 1b–f
Ru3(CO)12 and the appropriate phosphine ligand (in the ratio
1:1.05) in 10 ml dry deoxygenated THF were heated in an oil bath

O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
2669
(cyclohexane),
1989m cmꢀ1
m
(CO) 2099m, 2060w, 2048m, 2032sh, 2018s,
(m, CO). 31P NMR (CDCl3) d 41.56 (s, P ligand). Crystals suitable
for X-ray crystallography were grown by slow evaporation of a
n-pentane solution at 10 °C.
.
1H NMR (CDCl3) d 7.35–7.49 (m, 12H, Ph). 13C NMR
(CDCl3) d 129.1–133.2 (m, Ph), 203.6 (m, CO). 31P NMR (CDCl3) d
35.1–35.3 [t, P(C6H4-Cl-p)3]. Crystals suitable for X-ray crystallog-
raphy were grown from a solution of n-hexane/dichloromethane
at 10 °C.
2.2.6. Undecacarbonyl (tris-4-methylphenylphosphino) triruthenium
1e
Yield: 98.8 mg (69%), m.p. 176–179 °C. Elemental Anal. Calc. for
Ru3C32H21O11P: C, 41.97; H, 2.30. Found: C, 41.94; H, 2.29%. IR
2.2.5. Undecacarbonyl [tris(bis3,5-trifluoromethyl)phosphino]
triruthenium 1d
Yield: 128 mg (64%), m.p. 132–134 °C. Elemental Anal. Calc. for
Ru3C35H9O11F18P: C, 32.80; H, 0.70. Found: C, 32.81; H, 0.71%. IR
(cyclohexane),
m .
(CO) 2096m, 2059sh, 2044m, 2014s, 1989m cmꢀ1
1H NMR (CDCl3) d 2.35–2.45 (s, 9H, CH3), 7.19–7.40 (m, Ph). 31P
NMR (CDCl3) d 34.4–34.6 [t, P(C6H4Me-p)3]. X-ray quality crystals
were grown from a n-hexane solution at 10 °C.
(cyclohexane),
m (CO) 2106m, 2057s, 2038m, 2026s, 2006sh,
1991s cmꢀ1 1H NMR (CDCl3) d 7.30–8.16 (m, 9H, Ph). 13C NMR
.
(CDCl3) d 120.96–137.4 (m, Ph and tetrahedral carbons), 202.8
2.2.7. Reaction of Ru3(CO)12 with bis(4-methoxyphenyl) phenyl
phosphine 1f
Yield: 86 mg (58.9%). IR (cyclohexane),
m
(CO) 2096m, 2059w,
2044m, 2014s, 1989s cmꢀ1
.
1H NMR (CDCl3) d 3.9 (s, 6H, OCH3,),
6.9–7.5 (m, 13H, Ph). 13C NMR (CDCl3) d 55.7 (–OCH3), 125–136
(m, Ph), 161.6 (C–OCH3), 204.6 (m, CO). All attempts to crystallise
this compound to obtain single crystals suitable for XRD studies
were not successful.
2.3. X-ray structural determination
Determination of cell constants and data collection were carried
out at 100.0(1) K using the Oxford Cryosystem Cobra low-temper-
ature attachment with Mo K
a radiation (k = 0.71073) on a Bruker
SMART APEX2 CCD area-detector diffractometer equipped with a
graphite monochromator [15]. The data were reduced using SAINT
[15]. A semi-empirical absorption correction was applied to the
data using SADABS [15]. The structures were solved by direct meth-
ods and refined against F2 by full-matrix least-squares using SHELXTL
[16]. Hydrogen atoms were placed in calculated positions.
Fig. 1. The ORTEP diagram of 1a with 50% probability ellipsoids for non-H atoms.
Fig. 2. The crystal packing of 1a, viewed along the b axis, showing the molecules being linked into a 3-D network. Intermolecular hydrogen bonds are shown as dashed lines.

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O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
The ORTEP plot of Ru3(CO)11(Ph2PC6H4Me-p) is shown in Fig. 1.
The dihedral angles between the methylphenyl ring and the two
benzene rings for complex 1a are 79.69(17)° and 61.21(18)°,
respectively. Weak intermolecular C8–H8Aꢂ ꢂ ꢂO10 = 3.259(4) Å
and C11–H11Aꢂ ꢂ ꢂO7 = 3.320(5) Å hydrogen bonds linked the com-
plex 1a molecules into a three-dimensional network (Fig. 2). For
complex 1b, the pentafluorophenyl ring makes dihedral angles of
71.46(19)° and 57.0(2)° with the other two benzene rings (The OR-
TEP plot of complex 1b is shown in Fig. 3). The dihedral angles be-
tween the three phosphine-substituted rings are 63.68(7)°,
69.88(7)° and 78.74(7)° for complex 1c (The ORTEP plot of 1c is
shown in Fig. 4). In complex 1d; atoms F10, F11 and F12 are disor-
dered over three positions with site occupancies fixed to 0.34, 0.33
and 0.33, respectively at the final refinement (The ORTEP plot of 1d
is shown in Fig. 5). The same Uij parameters were used for the atom
pairs F10A/F11A/F8/F12A and F12B/F11C. Complex 1d is linked
into
a dimer by the intermolecular hydrogen bond C4–
H4Aꢂ ꢂ ꢂO5 = 3.452(3) Å (Fig. 6). The dihedral angles between the
three phosphine-substituted rings are 50.38(11)°, 60.89(11)° and
83.02(11)° for complex 1d. The ORTEP plot of Ru3(CO)11
P(C6H4-Me-p)3 is shown in Fig. 7. The dihedral angles between
Fig. 5. The ORTEP diagram of 1d with 50% probability ellipsoids for non-H atoms.
Only the major disorder component is shown.
the three phosphine-substituted rings are 68.59(11)°, 60.64(11)°
and 79.60(12)° for complex 1e. Crystal data and experimental de-
tails of the structure determinations are listed in Table 1. Details
of all hydrogen bonding geometry are listed in Table 3.
2.4. General structural considerations
The molecular structures of the five complexes 1a–e have been
determined. Table 2 summarises important bond lengths that are
found for these complexes. A comparison has been made in the
same table with Ru3(CO)12 and other monosubstituted complexes
of the same type (references have been mentioned).
3. Results and discussion
3.1. Synthesis and characterisation
The microanalyses of all the compounds agreed well with the
proposed molecular formulae for all the reported compounds with-
in the experimental errors. Isolation of a number of substituted
Fig. 3. The ORTEP diagram of 1b with 50% probability ellipsoids for non-H atoms.
derivatives of Ru3(CO)12 has enabled definitive information on
m
(CO) frequencies and the degree of substitution, which can be read-
ily determined from IR spectra. It has been observed that mono-
substituted clusters of Ru3(CO)12 are characterised by a high
energy absorption around 2100 cmꢀ1. Similar observations were
reported by Bruce et al. [8a]. Individual bands, however, may vary
slightly in position and relative intensity. 1H NMR spectra of 1a–c
and e showed a multiplet around d 7.2–7.6 ppm, characteristic of
phenyl groups. For the methyl groups, a singlet was observed at
d 2.4 for the Ph2P(C6H4Me-p) substituted cluster, and at d 2.4 for
the P(C6H4Me-p)3 substituted cluster. In the case of 1d, aromatic
protons were downfield and observed at higher d values due to –
CF3 groups (7.3–8.1 ppm). 13C NMR spectra of all the substituted
clusters showed prominent signals at around d 125–137 ppm,
characteristic of phenyl carbons. The carbonyl carbons in all the
clusters exhibited a multiplet, as a single broad peak. The broad-
ness of the single peak in the 13C NMR suggests that the carbonyl
ligands of the triruthenium cluster are fluxional in solution. A sim-
ilar observation was made by Lam et al. when they investigated the
reactions of 2-indolylphosphines with Ru3(CO)12 [11]. In addition,
the methyl carbons appeared at d 21 ppm for the cluster 1a. In
the case of the complex 1f, the methoxy carbons appeared at d
55 ppm, while the two tetrahedral carbons which are attached to
Fig. 4. The ORTEP diagram of 1c with 50% probability ellipsoids for non-H atoms.

O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
2671
Fig. 6. The intermolecular hydrogen bond linking 1d molecules into a dimer.
arrangement of three ruthenium atoms. The coordination of the
ligand was observed only at the phosphorus atom and in each case
the ligand occupies an equatorial site. In Ru3(CO)12, the average
Ru–Ru separations are 2.854 Å [17], one of the three Ru–Ru bonds
being slightly longer than the other two Ru–Ru bonds. The longest
Ru–Ru bond in Ru3(CO)12 is 2.859 Å. In the five complexes studied
(1a–e), the longest Ru–Ru bond is the bond that is cis to the ligand.
For the complex containing the ligand Ph2PC6F5, the longest Ru–Ru
bond is 2.886(4) Å. For complexes 1c–e, the longest Ru–Ru separa-
tions are 2.889(14), 2.888(2) and 2.884(2) Å, respectively. Among
all the complexes (1a–e), the longest Ru–Ru bond has been ob-
served for the complex Ru3(CO)11(Ph2PC6H4CH3-p) (1a), and this
is 2.896(3) Å. The uneven increase in the lengths of the metal–me-
tal bonds in comparison with those in Ru3(CO)12 can be attributed
to the steric effect induced by the bulky substituent. Another study
carried out on Os3(CO)11(PR3) compounds establishes that the elec-
tronic effect of the P ligand could also contribute to the changes in
the M–M bond lengths [18]. We have observed that Ru–Ru separa-
tions in all the complexes studied have ranges from 2.819(2) (for
1d) to 2.896(3) Å (for 1a). In the monosubstituted complexes of a
similar type synthesised by Bruce et al., the Ru–Ru separations
were reported to be in the range 2.839–2.920 Å [8a].
Fig. 7. The ORTEP diagram of 1e with 50% probability ellipsoids for non-H atoms.
There are no significant differences in the Ru–P distances of all
the complexes, the lowest being 2.333(6) Å for complex 1d and the
highest being 2.355(6) Å for complex 1e. In all the complexes stud-
ied, the average Ru–P bond length is slightly shorter compared to
the Ru–P bond length of 2.380(6) Å observed for Ru3(CO)11(PPh3),
in which the P atom is similarly bonded equatorially to the ruthe-
nium cluster [19]. Bruce et al. reported the range 2.238(1)–
2.399(4) Å for the four complexes they studied. In their study, they
correlated the shortest Ru–P bond length to the ligand with the
smaller cone angle [8a]. In the complexes, the ligand is approxi-
mately trans to one of the Ru–Ru bonds, and the Ru–Ru–P
angles among all the complexes range between 107.6(3)° for
Ru3(CO)11PPh2C6F5 and 113.0(9)° for Ru3(CO)11P(C6H4Cl-p)3.
As observed in Ru3(CO)12, the bonds from the metal atom to the
axial CO ligands are longer compared to the equatorial CO groups.
In Ru3(CO)12, the axial Ru–CO distances range in length from
1.929(4) to 1.953(5) Å [average 1.942(4) Å], and the equatorial
–OCH3 groups were observed at d 166 ppm. 31P NMR spectra
showed single signals at d 28.5 and 41.5 ppm for complexes 1b
and d, respectively. For the Ph2P(C6H4Me-p) substituted cluster, a
doublet appeared at d 35.5 ppm, while in case of clusters contain-
ing a ligand of the type PR3 (substituted at the para position), a
triplet is observed. Thus, in the case of the complex substituted
by the ligand P(C6H4Cl-p)3, a triplet with J(PP) = 10.4 Hz is observed
while a triplet with J(PP) = 11 Hz appeared in the case of the
P(C6H4Me-p)3 substituted cluster.
3.2. X-ray crystal structure analysis
The crystal structures of the five complexes 1a–e have been
determined. Table 2 summarises important bond lengths found
for these complexes. All the compounds contain a triangular

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O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
Table 1
Crystal data and structure refinement parameters for 1a–e.
Compound
1a
1b
1c
1d
1e
Empirical formula
Formula weight
T (K)
Wavelength (Å)
Crystal system
Space group
Unit cell dimensions
a (Å)
C
30H17O11PRu3
C29H10F5O11PRu3
963.55
100.0(1)
0.71073
monoclinic
C2/c
C29H12Cl3O11PRu3
976.92
100.0(1)
C35H9F18O11PRu3
1281.60
100.0(1)
C32H21O11PRu3
915.67
100.0(1)
0.71073
887.62
100.0(1)
0.71073
monoclinic
P21/c
0.71073
0.71073
triclinic
triclinic
triclinic
ꢀ
ꢀ
ꢀ
P1
P1
P1
12.0739(1)
15.4256(2)
20.2404(2)
90
125.378(1)
90
3073.64(7)
4
1.918
1728
1.567
0.18 ꢁ 0.23 ꢁ 0.36
2.1–35.1
60,267/13,566
0.033
42.2707(8)
9.0628(2)
16.3392(3)
90
90.666(1)
90
6259.0(2)
8
2.045
3712
1.570
0.05 ꢁ 0.24 ꢁ 0.36
1.0–31.6
43,813/10,450
0.059
9.5029(1)
12.4248(1)
15.0083(2)
95.042(1)
98.674(1)
110.865(1)
1617.56(3)
2
12.0228(1)
12.5224(1)
14.4396(2)
95.819(1)
92.337(1)
107.227(1)
2059.98(4)
2
9.6203(1)
12.3659(2)
15.3136(2)
95.932(1)
98.910(1)
111.326(1)
1651.11(4)
2
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
Z
Dcalc (Mg mꢀ3
F(0 0 0)
)
2.006
944
1.739
2.066
1232
1.264
1.842
896
1.462
Absorption coefficient (mmꢀ1
Crystal size (mm)
)
0.16 ꢁ 0.23 ꢁ 0.27
0.10 ꢁ 0.26 ꢁ 0.33
0.07 ꢁ 0.14 ꢁ 0.16
h range (°)
Reflections collected/unique
Rint
1.4–35.0
1.7–30.0
1.8–35.0
61,271/14,123
0.025
92,293/12,007
0.028
53,063/14,419
0.049
Data/restraints/parameters
Goodness-of-fit (GOF) on F2
13,566/0/407
1.26
10,450/0/442
1.02
14,123/0/424
1.03
12,007/0/618
1.03
14,419/0/427
0.99
Final R indices [I > 2
r
(I)]
R1 = 0.0455
wR2 = 0.0811
R1 = 0.0608
wR2 = 0.0847
ꢀ1.82 and 1.64
R1 = 0.0461
wR2 = 0.1071
R1 = 0.0744
wR2 = 0.1248
ꢀ1.06 and 1.14
R1 = 0.0220
wR2 = 0.0458
R1 = 0.0277
wR2 = 0.0485
ꢀ0.54 and 0.64
R1 = 0.0302
wR2 = 0.0737
R1 = 0.0337
wR2 = 0.0762
ꢀ1.42 and 1.96
R1 = 0.0405
wR2 = 0.0661
R1 = 0.0651
wR2 = 0.0718
ꢀ0.99 and 0.86
R indices (all data)
Largest difference peak and hole (e Åꢀ3
)
Table 2
Bond distances (Å) in Ru3(CO)11(L) complexes.
ax
eq
eq'
M
3
b
c
ax''
ax
eq
eq
a
2
1
d
M
L
M
eq''
M
L
No.
M–M
M–L
M–CO
References
c
a
b
c
axb
eq
eq0
ax’’d
eq’’
Ru
Ru
CO
CY3
2.852(1)
2.878(2)
2.875(2)
2.876(3)
2.846(1)
2.859(1)
2.8515(3)
2.8524(4)
2.83678(14)
2.8333(2)
2.8402(3)
2.851(1)
2.859(2)
2.874(2)
2.875(3)
2.858(1)
2.846(1)
2.8475(3)
2.8526(4)
2.83333(15)
2.8188(2)
2.8440(2)
2.860(1)
2.902(2)
2.920(2)
2.907(3)
2.872(1)
2.862(1)
2.8966(3)
2.8865(4)
2.88946(14)
2.8884(2)
2.8837(2)
1.942(4)
1.94
1.95
1.921(5)
1.92
1.91
1.89
1.91
1.921
1.923
1.927
1.9193
1.9324
1.922
[17]
[20]
[20]
[19]
[8a]
a
2.425(3)
2.430(3)
2.380(6)
2.287(1)
2.254(1)
2.3477(7)
2.3429(10)
2.3455(3)
2.3337(6)
2.3457(6)
1.93(1)
1.90(1)
1.91(3)
1.909(5)
1.887(5)
1.930(3)
1.921(4)
1.936(14)
1.926(2)
1.935(2)
1.94
1.92
1.92
1.933
1.931
1.94
1.943
1.9411
1.939
1.941
1.90(1)
1.87(1)
1.86(3)
1.888(4)
1.911(5)
1.892(3)
1.883(4)
1.8973(14)
1.904(2)
1.890(2)
Ru
Ru
Ru
Ru
Ru
Ru
Ru
Ru
PPh3
PPh(OMe)2
1.94
1.943
1.943
1.941
1.9473
1.946
1.9495
1.9448
P(OCH2CF3)3
Ph2P(C6H4Me-p)3
Ph2PC6F5
P(C6H4Cl-p)3
P(3,5-CF3–C6H3)3
P(C6H4Me-p)3
[8a]
e
1a
1b
1c
1d
1e
e
e
e
e
a
b
c
Values of two independent molecules.
Average of four.
Average of three.
Average of two.
This work.
d
e

O.b. Shawkataly et al. / Polyhedron 29 (2010) 2667–2673
2673
Table 3
4. Conclusion
Hydrogen-bonding geometries (Å, °).
D–Hꢂ ꢂ ꢂA
Distance (Å)
D–H
Distance (Å)
Hꢂ ꢂ ꢂA
Distance (Å)
Dꢂ ꢂ ꢂA
Angle (°)
D–Hꢂ ꢂ ꢂA
Several monosubstituted triruthenium cluster carbonyl com-
plexes were synthesised with different phosphine ligands (both
the PR3 and Ph2PR type). In all the five complexes reported, the li-
gands occupy equatorial positions and coordination of the ligands
are only at the phosphorus atom. Due to the steric effect of the li-
gand, one of the metal–metal bonds is significantly longer than the
other two. 13C NMR spectra of the all the monosubstituted
complexes showed a single broad peak for CO instead of a
multiplet, exhibiting the fluxional behaviour of CO in solution. In
Ru3(CO)11P[3,5-CF3-C6H3]3, there is disorder of the –CF3 groups.
1a
C8–H8Aꢂ ꢂ ꢂO10i
0.93
0.93
2.45
2.55
3.259(4)
3.320(5)
145
140
C11–H11Aꢂ ꢂ ꢂO7ii
Symmetry codes: (i) 1 ꢀ x, 2 ꢀ y, 2 ꢀ z and (ii) ꢀx, ꢀ1/2 + y, 3/2 ꢀ z.
1b
None
1c
C3–H3Aꢂ ꢂ ꢂCg2i
0.93
2.75
3.6301(15)
158
Symmetry codes: (i) 1 ꢀ x, ꢀy, ꢀz; Cg2 is the centroid of benzene ring C7–C12.
5. Supplementary data
1d
C4–H4Aꢂ ꢂ ꢂO5i
Symmetry codes: (i) 1 ꢀ x, 2 ꢀ y, ꢀz.
0.93
2.60
3.452(3)
153
CCDC 761605, 761606, 761607, 761608 and 761609 contain the
supplementary crystallographic data for 1a–e. These data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/conts/
retrieving.html, or from the Cambridge Crystallographic Data Cen-
tre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: (+44) 1223-336-
033; or e-mail: deposit@ccdc.cam.ac.uk.
1e
C3–H3Aꢂ ꢂ ꢂCg3i
0.93
2.76
3.618(3)
154
Symmetry codes: (i) 1 ꢀ x, 1 ꢀ y, 1ꢀz; Cg3 is the centroid of benzene ring
C13–C18
Acknowledgements
Ru–CO distances range from 1.908(5) to 1.934(5) Å, [average
1.921(5) Å]. The average axial Ru–CO distances for the five com-
plexes 1a–e are 1.941(3), 1.946(4), 1.944(2), 1.946(2) and
1.944(2) Å respectively, which are longer than the average equato-
rial Ru–CO distances of 1.918(3), 1.914(5), 1.918(1), 1.925(3) and
1.918(3) Å for the complexes 1a–e in the same order. The differ-
ence between the longest and the shortest average axial Ru–CO
distances (for 1a–e) is 0.005 Å, while the difference between the
longest and the shortest average equatorial Ru–CO distances for
the same complexes is 0.012 Å.
In Ru3(CO)12, the equatorial Ru–C–O moieties are almost linear
(the average Ru–C–O angle is 178.9°) while the axial Ru–C–O moi-
eties are slightly bent (average 172.98°) [17]. The reason for this
distortion is attributed to the Van der Waals repulsion between
the oxygen atoms. In the monosubstituted complexes, the equato-
rial CO groups (Ru–C–O bond angle) are essentially linear (average
value for all the five complexes studied 176.9°, range 176.3–
177.6°), while the axial CO groups are slightly bent (mean value
of Ru–C–O bond angle 173.9°, range 173.8–174.1°). In the
monosubstituted complexes of Ru3(CO)12 studied by Bruce et al.,
the values for the equatorial Ru–CO moieties were also linear
(mean value for the complexes studied 177.5°, range 175.7–
178.3°), while the angles for axial CO groups were averaging
173.3° (range 172.2–175.2°) [8a].
In Ru3(CO)12, the average axial OC–Ru–CO angles are 178.3° and
the average equatorial OC–Ru–CO angles are 104.1°. In the mono-
substituted complexes studied by us, the average axial OC–Ru–CO
angles are 172.1°, 172.4°, 170.4°, 171.8° and 170.5° for the five
complexes (1a–e); the mean value for all the complexes being
171.4°. While the average equatorial OC–Ru–CO angles are
100.7°, 98.9°, 100.5°, 101.9° and 100.9° (for 1a–e) in the same or-
der, the mean value being 100.6°. These observations are consis-
tent with previously published observations of monosubstituted
triuthenium cluster complexes [8a].
The authors would like to thank the Malaysian Government and
Universiti Sains Malaysia (USM) for the Research Grant 1001/
PJJAUH/811115. MAAP thanks USM for Post doctoral fellowship.
HKF thanks USM for the Research University Golden Goose Grant
1001/PFIZIK/811012. CSY also thanks USM for the award of a
USM Fellowship.
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