Solid state structure and fluxionality in solution of [H4Ru 4(CO)11L] (L=P(C6F5)3, PMe2Ph, P(OMe)3 and P(OEt)3): Two different structures

Article abstract of DOI:10.1016/j.poly.2003.08.009

The monosubstituted [H₄Ru₄(CO)₁₁L] derivatives where L=P(C₆F₅)₃, PMe ₂Ph, P(OMe)₃ and P(OEt)₃ (compounds 1 to 4, respectively) were synthesized, the crystal structure of 1, 2 and 4 were determined by X-ray diffraction (that of compound 3 had been determined previously but not fully reported so we obtained it again) and their dynamical behavior studied by ¹H, ³¹P and ¹⁹F NMR. The structures of compounds 1, 3 and 4 show the common tetrahedral structure with four long (hydride bridged) and two short metal-metal bonds with the P-donor ligand transoid to an unbridged Ru-Ru bond. The structure of 2 is different since the M-M bonds to the Ru atom bonded to the phosphine, are all hydride-bridged. The variable temperature NMR studies of 1, 2 and 3 show dynamical behaviour similar to what had been reported for compound 4. However we propose that some of the structures involved in the equilibrium have the phosphorus substituent transoid to a bridged Ru-Ru bond.

Full text of DOI:10.1016/j.poly.2003.08.009

Polyhedron 22 (2003) 3403–3411
www.elsevier.com/locate/poly
Solid state structure and fluxionality in solution of
[H4Ru4(CO)11L] (L ¼ P(C6F5)3, PMe2Ph, P(OMe)3
and P(OEt)3): two different structures
1
M. Gabriela Ballinas-Lopez, Efren V. Garcıa-Baez , Marıa J. Rosales-Hoz
*
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
Departamento de Quꢀımica, Centro de Investigacioꢀn y de Estudios Avanzados del I.P.N., Apdo. Postal 14-740, 07000 Meꢀxico, DF, Mexico
Received 1 December 2002; accepted 15 August 2003
Abstract
The monosubstituted [H4Ru4(CO)11L] derivatives where L ¼ P(C6F5)3, PMe2Ph, P(OMe)3 and P(OEt)3 (compounds 1 to 4,
respectively) were synthesized, the crystal structure of 1, 2 and 4 were determined by X-ray diffraction (that of compound 3 had been
determined previously but not fully reported so we obtained it again) and their dynamical behavior studied by 1H, 31P and 19F
NMR. The structures of compounds 1, 3 and 4 show the common tetrahedral structure with four long (hydride bridged) and two
short metal–metal bonds with the P-donor ligand transoid to an unbridged Ru–Ru bond. The structure of 2 is different since the M–
M bonds to the Ru atom bonded to the phosphine, are all hydride-bridged. The variable temperature NMR studies of 1, 2 and 3
show dynamical behaviour similar to what had been reported for compound 4. However we propose that some of the structures
involved in the equilibrium have the phosphorus substituent transoid to a bridged Ru–Ru bond.
Ó 2003 Elsevier Ltd. All rights reserved.
Keywords: Solid state structures; Synthesis; Spectroscopic data; Polymetallic complexes
1. Introduction
other allowing a general D2d symmetry while in the other
arrangement three of the long bonds span the tetrahedral
edges adjacent to a single metal atom forming a metal
core of Cs symmetry. Both arrangements have been ob-
served in X-ray crystal structures of some of these de-
rivatives [5–7] and this suggests a small energy difference
between both structures as it is confirmed by the fluxional
behavior shown by the hydrides in solution.
One of the studies reported on the dynamics of these
derivatives is that carried out by Aime et al. [8]. In this
study the authors observe, at low temperature, the
presence of three isomers in the solution of the mono-
substituted [H4Ru4(CO)11P(OEt)3] and conclude that
both hydride motion and CO exchange are taking place.
The availability of fast X-ray diffractometers allows
the study of the effect of different substituents in the
geometry of a particular cluster framework and this has
been carried out for [Os3(CO)11L] [9] and [Rh6(CO)15L]
[10], among other cluster compounds. Another study
[11] has shown that the mechanism followed by substi-
tution reactions of [Ru5C(CO)15] is affected by electronic
and steric characteristics of the entering ligand.
The chemistry of the tetranuclear cluster [H4Ru4
(CO)12] has been studied in some detail [1]. Reactions
with phosphines and phosphites, alkynes and other de-
rivatives have been carried out. The compound and
some of its phosphine and phosphite derivatives, all
tetrahedral 60-electron clusters, were tested as catalysts
for polymerization of olefines [2] and reduction of
aldehydes [3].
All these tetrahedral clusters show the well known
pattern [4] of four long and two short metal–metal bonds.
The long bonds are considered to be those bridged by the
four hydride groups. There are two ways of accommo-
dating four hydride ligands in a tetrahedral metal cluster.
In one, the two short Ru–Ru bonds are opposite each
* Corresponding author. Tel.: +52-5-747-3800; fax: +52-5-747-7113.
E-mail address: mrosales@mail.cinvestav.mx (M.J. Rosales-Hoz).
1
ꢀ
Present address: Departamento de Quımica, Unidad Profesional
Interdisciplinaria de Biotecnologıa del I.P.N., Av. Acueducto s/n,
ꢀ
ꢀ
Barrio La Laguna Ticoman, 07340 Mexico, DF, Mexico.
ꢀ
0277-5387/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2003.08.009

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M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
As part of a study on the reactivity of substi-
donor ligand [14] so the trend observed would have to
be associated with the poor donor ability of the ligand
towards the metal core.
tuted transition metal clusters, we have prepared four
substituted derivatives of [H4Ru4(CO)12], namely
[H4Ru4(CO)11L] with L ¼ P(C6F5)3, PMe2Ph, P(OMe3)
and P(OEt)3 (compounds 1–4, respectively). Com-
pounds 3 and 4 had been previously prepared and
spectroscopic data of compound 4 was reported by
Aime et al. [8] while structural characterization of 3 had
been carried out previously [12] although, to our
knowledge, the complete structural details were not
published. We have carried out structural character-
ization of compounds 1–4 in order to compare and
analyze the data. The structure of compound 3 was
repeated in order to have more structural information
that would allow an analysis to be made; it is important
to mention that the cell dimensions we obtained are
different from those reported. Also, variable tempera-
ture multinuclear NMR studies were carried out for the
same compounds. The dynamical behaviour is dis-
cussed in relation with the structural characteristics of
each compound. Results are reported herein.
1
The H NMR spectrum of 1 shows a slightly broad
doublet with a J(31P–1H) ¼ 7 Hz while in the 31P NMR
spectrum, only a singlet is observed; the 31P–19F cou-
pling observed in the non-coordinated phosphine is not
observed in the cluster compound. It is important to
point out that compound 1 is not stable in solution and
after a few minutes, the spectrum shows signals due to
the starting materials. This behaviour is in sharp con-
trast with the stability shown by compounds 2–4.
2.2. Structural characterization
Molecular plots of compounds 1, 2 and 4 are shown
in Figs. 1–3 while some selected bond distances and
angles are given in Table 3. As already pointed out, the
structure of compound 3 had been carried out but not
reported in detail therefore we repeated it in our labo-
ratory in order to be able to compare the results with
those of the other compounds we are interested in; the
unit cell information we obtained is different from that
described [15] so we believe this is another isomorphous
crystalline form. The bond lengths and angles we ob-
tained are also included in Table 3; they are not very
different to those described in similar structures [16]; the
molecular structure and numbering scheme of com-
pound 3 is shown in Fig. 4.
Compounds 1, 3 and 4 show the same general
structure of a ‘‘Ru4H4’’ core of D2d geometry while in
compound 2, three of the hydrides bridge the edges
adjacent to the ruthenium atom which is bonded to the
phosphine in a similar pattern to that observed in di-
phosphine derivatives [7]. Additionally, while in the first
three compounds the phosphorous ligands form P–Ru–
Ru transoid angles of 172.26(3)°; compound 1; 165.31(5)°
and 166.13(5)°; compound 3 and 165.45(6)°; compound
4; the distortion from the ideal trans angle is larger in 2
with a value of 159.03(5)° for the transoid P–Ru–Ru
angle. The corresponding angles in [H4Ru4(CO)10L2] are
ca. 165° when L ¼ P(OEt)3 and ca. 171° when L ¼ PPh3.
Puga et al. [7] suggested that the Cs structure observed
in [H4Ru4(CO)10(diphos)] allows the H atoms to attain
the maximum possible proximity to the electron rich
metal atoms, i.e. those which are bonded to the phos-
phine with aliphatic substituents, better r-donors than
either phosphites or aryl substituted phosphines [14]. On
2. Results and discussion
2.1. Synthesis and spectroscopic characterization
The synthesis of substituted derivatives of [H4Ru4
(CO)12] has been studied using different activation
methods. Since thermal activation produces very low
yields of the monosubstituted compounds [H4Ru4
(CO)11L], for the synthesis of the phosphite derivatives
(compounds 3 and 4) and for the preparation of com-
pound 2, we used the same method that Aime et al. [8]
activating the cluster with [FeCp(CO)2]. This method
though, does not produce satisfactory results for the
preparation of compound 1 therefore trimethyl amine
oxide was used in that case.
IR and NMR spectroscopic information for com-
pounds 1, 2 and 3 is given in Section 3 and in Tables 1
and 2. The data obtained for compound 4 is similar to
what had been reported previously. The IR information
shows that carbonyl stretching frequencies for com-
pound 1 appear at higher values indicating a lower back
donation from the metal atoms to the COs as had been
observed in other cluster compounds containing fluori-
nated phosphine substituents [13]. A recent study poin-
ted out that P(C6F5)3 is not a p acid and is a very poor r
Table 1
Physical description and infrared data for compounds 1–3
Compound
Colour
Melting point (°C)
IR m(CO, cmꢀ1) (in hexane)
1
2
3
orange
orange red
orange
154.4
127–129 (sublimes)
104–105 (sublimes)
2100(d), 2078(f), 2066(f), 2040(f), 2022(m), 2016(m), 1990(m)
2094(d), 2088(d), 2066(m), 2058(f), 2032(m), 2026(m), 2008(m), 1990(d)
2096(d), 2068(f), 2058(f), 2030(f), 2016(m), 2008(f), 1994(d)

M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
3405
Table 2
1H, 31P, 19F and 13C NMR data for compounds 1–3a
Compound
1H
1
2
3b
)17.39(d, w)
2.24 (d, CH3) 2J(31P–1H) ¼ 9.96,
7.54(m, Ph), )17.51(s,w, M–H)
3.7308(d, Me)
3J(31P–1H) ¼ 12.16 Hz;
)17.737 (d, M–H)
J(31P–1H) ¼ 2.145 Hz)
139.88(s)
31P
31P(1H)
)23.43(s)
)23.47(m)
5.99(s)
5.99 (m, w)
139.85(oq)
3J(31P–1H) ¼ 2.1 Hz,
3J(31P–1H) ¼ 2.12 Hz
methyl: 52.68(d)
2J(31P–13C) ¼ 5.14 Hz
13C
aromatics: 125.34 (s, Cp), 126.23(s, Cp),
127.06(s, Cm), 127.73(s, Cm), 128.98(s, Co),
130.11(s, Co), 150.98(s, Ci); COÕs:
methyl: 22.14(d),
1J(31P–13 C) ¼ 33.83 Hz
184.27(m), 185.66(s), 189.18(s), 190.04(s),
190.8(s), 192,58(s), 193.52(s)
aromatics: d (Cm) ¼ 129. 17(d)
3J(31P–Cm) ¼ 10.04 Hz;
d (Co) ¼ 129.69(d),
carbonyls: d (2E) ¼ 193.4,
d (4A) ¼ 192.9,
d (2B/2C) ¼ 191.8,
d (D) ¼ 191.3(d),
2J(31P–Co) ¼ 10.32 Hz;
d (Cp) ¼ 131.24(d),
3J(31P–13C) ¼ 9.23 Hz),
d (2B/2C) ¼ 189.1
4J(31P–Cp) ¼ 2.56 Hz;
d (Ci) ¼ 137.67 (d),
1J(31P–Ci) ¼ 49.13 Hz
carbonyls: d (2A, 2B, 2C, 2E,
2F) ¼ 193.21(s,w),
d (D) ¼ 189.57(d),
3J(31P–13C) ¼ 9.41 Hz
D(Me) ¼ 22.14(qdq),
1J(13C–1H) ¼ 127.66 Hz,
3J(13C–1Hydride) ¼ 2.1 Hz
13C(1H)
not obtained
methyl: 52.69(qd),
1J(13C–1H) ¼ 147.47 Hz,
2J(31P–13C) ¼ 5.1 Hz
19F
Fortho: d ¼ )127.35(d, 6F)
3J(19Fo–19Fm) ¼ 18.66 Hz
Fpara: d ¼ )146. 01 (tt, 3F)
3J(19Fp–19Fm) ¼ 20.77 Hz,
4J(19Fp–19Fo) ¼ 5.1 Hz
Fmeta: d ¼ )158.63 (dd, 6F)
3J(19Fo–19Fm) ¼ 18.86 Hz,
3J(19Fp–19Fm) ¼ 20.62 Hz
a Obtained in COCl3.
b
13C obtained at )30 °C.
Fig. 1. Molecular structure, including numbering scheme, of
[H4Ru4(CO)11P(C6F5)3], compound 1.
the other hand, the largest P–Ru–Ru transoid angles are
found in the case of phosphines with large cone angles as
it is in the case of 1 (see Table 3).
Fig. 2. Molecular structure, including numbering scheme, of
[H4Ru4(CO)11PMe2Ph], compound 2.

3406
M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
Fig. 3. Molecular structure, including numbering scheme, of
[H4Ru4(CO)11P(OEt)3], compound 4.
Another characteristic of 2 that is worth pointing out
is that it has the longest Ru–Ru long bond lengths of the
ꢁ
4 compounds, with an average value of 2.978 A. Short
Ru–Ru bond lengths are similar in all 4 compounds.
Studies carried out on the systematic structural changes
caused by different substituents in some transition metal
clusters [9,10,17] have shown that there is some length-
ening of metal–metal bonds trans and cis to the sub-
stituents. This is not the case in compounds 1–4,
probably due to the presence of the hydrides. Neither do
we observe a direct relationship between cone angle of
the phosphine and M–M bonds. Compound 1 which
contains P(C6F5) (Cone angle ¼ 184°) does not show
significantly different M–M bond distances from the
other three compounds.
Fig. 4. Molecular structure, including numbering scheme, of
[H4Ru4(CO)11P(OMe)3], compound 3.
2 are similar and significantly different from those in 3
and 4. According to the QALE method [14], of the four
phosphorus ligands used in our study, PMe2Ph is the
best r-donor and P(C6F5)3 is the worst but the Ru–P
bonds in their corresponding compounds differ only by
ꢁ
0.018 A while comparing the same values in compounds
2 and 4, (with more similar r-donor capacities; 10.5
ꢁ
versus 15.8); gives a difference of 0.0576 A, a difference
As expected, larger differences are found when com-
paring Ru–P distances. A highly significant trend of
increasing Ru–P bond lengths with increasing donicity
and/or size of the substituents has been observed [10] but
no clear trend can be deduced in our small set of com-
pounds. Values for Ru–P distances in compounds 1 and
which can be a consequence of the larger cone angle of
PMe2Ph (122° versus 109°).
Metal carbonyl bonds show very similar values in all
our compounds with Ru–C distances averaging to 1.902,
ꢁ
1.9002, 1.899 and 1.902 A, respectively, for compounds
1–4.
Table 3
ꢁ
Selected bond lengths (A) and angles (°) for compounds 1–4
Compound
1
2
3a
4
Bond lengths
Ru(l)–Ru(2)
Ru(l)–Ru(3)
Ru(l)–Ru(4)
Ru(2)–Ru(3)
Ru(2)–Ru(4)
Ru(3)–Ru(4)
Ru(1)–P(1)
2.9532 (7)
2.9605 (7)
2.7841 (9)
2.7834 (8)
2.9582 (8)
2.9417 (8)
2.362 (1)
2.9774 (7)
3.0191 (10)
2.9838 (7)
2.9328 (7)
2.7823 (7)
2.7846 (8)
2.345 (1)
2.9531 (12); 2.9647 (12)
2.9427 (9); 2.9601 (9)
2.7873 (10); 2.7834 (9)
2.7921 (12); 2.7943 (13)
2.9668 (10); 2.9579 (10)
2.9568 (11); 2.9698 (12)
2.286 (2) 2.281 (2)
2.792 (1)
2.967 (2)
2.971 (1)
2.958 (1)
2.957 (1)
2.786 (1)
2.287 (2)
Bond angles
P(1)–Ru(1)–Ru(2)
P(1)–Ru(1)–Ru(3)
P(1)–Ru(1)–Ru(4)
114.42 (4)
110.74 (3)
172.25 (3)
108.00 (4)
106.15 (4)
159.03 (4)
104.92 (5); 105.09 (5)
107.35 (5); 105.64 (5)
166.13 (5); 165.31 (5)
165.44 (6)
105.81 (7)
105.73 (6)
a There are two molecules in the asymmetric unit.

M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
3407
An analysis of intramolecular non-bonded distances
in compound 1, shows a close contact between two of
the hydrides and two of the ortho-substituted fluorine
ꢁ
atoms (H(12)–F(112) 2.44(6) A and H(13)–F(136)
ꢁ
2.54(7) A). These values are below the sum of the van
der Waals radii [18].
M–H and C–F bonds have been considered as weak
donors and weak acceptors, respectively, for the for-
mation of hydrogen bonds [19]. However it has been
shown that metal hydrides in polymetallic complexes
can form hydrogen bonds if the hydrogen bond is not
sterically hindered [20]. On the other hand, fluorine at-
oms in fluorobenzenes have also been observed to form
C–H–F interactions [21]. Therefore a hydride–fluorine
interaction seems plausible and we have evidence of its
existence in another cluster compound [13]. It has to be
pointed out that no evidence of such an interaction is
observed in the solution NMR spectra of compound 1.
Fig. 5. Variable temperature ()90 to 100 °C) 1H NMR spectra in the
hydride region of [H4Ru4(CO)11P(C6F5)3], compound 1.
spectra shows a singlet which remains constant at the
whole temperature interval studied and, apart from a
signal corresponding to the free phosphine, only two very
small signals are observed at )90 °C. At this same tem-
perature, the study of compound 4 reported shows in the
1H spectrum two wide signals which split into seven sig-
nals at )120 °C. The 31P NMR spectrum of 4 at )90 °C
shows one major and one minor signals.
2.3. Dynamics of compounds 1, 2 and 3
The VT NMR studies carried out in compound 4 and
the similar PPh3 and AsPh3 derivatives [8], suggested
that the hydrides are scrambling over the whole tetra-
hedron while the Ru(CO)3 moieties exhibit a localized
1
1
exchange. The 31P and H spectra of 4 at )120° were
In the case of compound 2, we could obtain the H
explained by the presence of one geometrical major
isomer, probably the one observed in the solid state, and
a less symmetrical set of two minor isomers of equal
populations. The structures of these isomers were pro-
posed imposing as a restriction that the phosphine li-
gand has to be transoid to a non-bridged metal–metal
edge, as it is observed in the solid state of this com-
pound. In order to observe whether the different sub-
stituents modified the dynamical behaviour of the
derivatives, variable temperature NMR studies of
compounds 1, 2 and 3 were carried out. Due to some
technical problems only compound 2 was analysed at
temperatures between )120 and )90 °C. The lowest
temperature used for the other two compounds was
)90 °C.
spectra at )120 °C and it shows two single wide signals
and one wide doublet (Fig. 6). These signals become
narrower when the spectrum is obtained at )110 °C and
one of the wide single signal splits into a doublet and
this pattern remains until )90 °C. The relative intensity
of the signals is 1:1. At )90 °C one of the signals splits
into a wide singlet and a doublet (J ¼ 29.83 Hz) while
the other signal splits into a doublet with a coupling
constant value of 17.26 Hz. The relative intensities of
the signals are 1:1:2. These also suggests the presence of
three isomers: a major one, presumably with the
structure observed in the solid state, and two minor
isomers.
As expected, compound 3 shows very similar variable
temperature NMR spectroscopic spectra to the ones
reported for compound 4, therefore suggesting a similar
dynamical behaviour in both compounds. As mentioned
above, Aime et al. proposed the different isomeric
structures taking as a premise that they would always
have the phosphine ligand transoid to a non-bridged
metal–metal bond (Structures I, II and III in Scheme 1).
The structure observed in compound 2 (Structure IV in
Scheme 1), could mean this will not necessarily be true
and that similar structures could be present, even if it is
as minor isomers, for compounds 3 and 4.
A similar study in compound 1 showed a similar be-
1
haviour. Fig. 5 includes H spectra of compound 1 ob-
tained at 10° intervals from )90 to 100 °C. As mentioned
previously, the H spectrum of 1 at room temperature
1
only shows a slightly wide doublet indicating the equiv-
alence of the four hydrides; the doublet (J(31P–1H) ¼ 7.04
Hz) becomes a wide singlet at 10 °C which at )20 °C
changes to two wide signals which then split into a dou-
blet each at )30 °C, these two signals have equal intensity
with two different coupling constants to phosphorus
(2.92 and 9.76 Hz), suggesting that the solution contains
two isomers as a result of the hydride migration. These
signals remain unchanged until )80° while at )90° both
signals become wider and only one of them remains as a
Another aspect that has to be pointed out is that in
the spectra of compound 2, the most intense signal,
which we think corresponds to the structure observed in
1
the solid state, shows a smaller H–31P coupling con-
doublet (J(31P–1H) ¼ 3.2 Hz). On the other hand, the 31
P
stant than the ones observed for the other isomers. This

3408
M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
Fig. 6. Variable temperature ()120 to )90 °C) 1H NMR spectra in the hydride region of [H4Ru4(CO)11PMe2Ph], compound 2.
Scheme 1.

M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
3409
3
4
would mean that coupling constant values for some of
the vicinal hydrides show larger values than the corre-
sponding values for geminal hydrides. All three com-
pounds show signals with different coupling constants.
The values for 1 and 2 were already mentioned while in 3
we can observe signals with J(31P–1H) ¼ 11.7 and 1.9
Hz. Structures I–VI have different numbers of vicinal
and geminal hydrides and the sum of the different
numbers of each in the different structures participating
in the equilibrium could give as a result signals with
different relative intensities and coupling constants.
With these points in mind we propose that the
structures participating in the dynamical equilibrium in
all 4 compounds are I, IV, V and VI in Scheme 1 with
structure I (of D2d symmetry) as the major isomer in
compounds 1, 3 and 4 and structure IV (Cs symmetry)
as the major isomer in the case of compound 2.
d ¼ )146.01(tt, 3F) J(19Fp–19Fm) ¼ 20.77 Hz, J(19Fp–
19Fo)¼5.1 Hz Fmeta: d¼)158.63(dd,6F) 3J(19Fo–19Fm)¼
18.86 Hz, 3J(19Fp–19Fm) ¼ 20.62 Hz (see Table 2).
3.3. Synthesis of [H4Ru4(CO)11(PMe2Ph], compound 2
[H4Ru4(CO)12] (0.111 g; 0.15 mmol) and [FeCp
(CO)2]2 (0.006 g; 0.015 mmol) were dissolved in 20 ml of
cyclohexane and the suspension is placed in an ultra-
sound bath for 10 min. After that time PMe2Ph (0.18
mmol) is added to the solution and the bath is heated to
42 °C for 2 h. The solvent is then evaporated to dryness
and the residue purified by column chromatography
using silica and a 7:3 heptane–dichloromethane solu-
tion. Orange red crystals were obtained from a con-
centrated dichloromethane solution. Melting point:
127–129 °C. FAB 854 amu. Microanalysis: C: 26.23%
(26.7%), H: 1.71%(1.77). Yield: 44.18%. Infrared data:
2094(d), 2088(d), 2066(m), 2058(f), 2032(m), 2026(m),
1
2
3. Experimental
2008(m),1990(d). NMR data: H: 2.24(d, CH3) J(31P–
1H) ¼ 9.96, 7.54(m, Ph), )17.51(s,w, M–H). 31P: 5.99(s),
31P(1H): 5.99(m,w); 13C: Methyl: 22.14(d), 1J(31P–13C) ¼
3.1. General procedures
33.83 Hz, Aromatics: d (Cm) ¼ 129.17(d) J(31P–Cm) ¼
3
2
All reactions and other manipulations were carried
out under a nitrogen atmosphere using standard
Schlenk techniques. All solvents were dried and distilled
under a nitrogen atmosphere prior to use. Infrared
spectra were recorded on a Pekin–Elmer 2000 spec-
trometer in hexane solutions. NMR spectra were ob-
tained in a Jeol Eclipse 400 or a Bruker AvanceTM DPX
300 spectrometers, 1H and 13C spectra relative to SiMe4
and 31P relative to H3PO4, in CDCl3 solutions.
[Ru3(CO)12] and the phosphines were purchased from
Strem and Aldrich and were used without further puri-
fication. Me3NO was also dried prior to use.
[H4Ru4(CO)12] was prepared as reported [22].
10.04 Hz; d (Co) ¼ 129.69(d), J(31P–Co) ¼ 10.32 Hz; d
(Cp)¼131.24(d), 4J(31P–Cp)¼2.56 Hz; d (Ci)¼137.67(d),
1J(31P–Ci) ¼ 49.13 Hz, Carbonyls: d (2A, 2B, 2C, 2E,
2F) ¼ 193.21(s,w), d (D) ¼ 189.57(d), J(31P–13C) ¼ 9.41
3
Hz; 13C(1H): d (Me) ¼ 22.14(qdq), J(13C–1H) ¼ 127.66
1
Hz, J(13C–1Hhydride) ¼ 2.1 Hz.
3
3.4. Synthesis of [H4Ru4(CO)11(P(OMe)3] and [H4Ru4
(CO)11(P(OEt)3], compounds 3 and 4
[H4Ru4(CO)11L] (L ¼ P(OMe)3 and P(OEt)3) were
prepared following the procedure reported by Aime et al.
[8]. Although using an ultrasound bath and 2 equivalents
of the phosphite for each one of the cluster compound [8].
Yield of compound 3: 32%; yield of compound 4; 34.2%.
Microanalysis for 3: C: 20.94%(20.01), H: 1.60%(1.56).
Microanalysis for 4; C: 23.66%(23.14), H: 2.17%(2.17).
FAB for 3: 842; FAB for 4: 882; Melting point for 3: 104–
105 °C (sublimes). Infrared data for 3: 2096(d), 2068(f),
2058(f), 2030(f), 2016(m), 2008(f), 1994(d). NMR data for
3.2. Synthesis of [H4Ru4(CO)11(P(C6F5)3)], compound 1
[H4Ru4(CO)12] (0.03 g; 0.04 mmol) and P(C6F5)3
(0.0268 g, 0.05 mmol) were dissolved in 20 ml of dichlo-
romethane. Me3NO (0.5 eq., 0.0015 g) dissolved in ace-
tonitrile (7.5 ml) was slowly added to the first solution
kept at )10 °C and the solution was stirred for 1 h. The
resulting solution is filtered through a column packed
with silica and the solvent was then removed under vac-
uum. Orange crystals of 1 are obtained from a concen-
trated dichloromethane solution. Melting point: 154–155
°C. FAB for 1: 1248. Yield: 32%. Infrared data: 2100(d),
2078(f), 2066(f), 2040(f), 2022(m), 2016(m), 1990(m).
3: H: 3.7308(d, Me) J(31P–1H) ¼ 12.16 Hz; )17.737(d,
1
3
M–H) J(31P–1H) ¼ 2.145 Hz); 31P: 139.88(s), 31P(1H):
139.85(oq) J(31P–1H) ¼ 2.1 Hz, J(31P–1H) ¼ 2.12 Hz;
13C (obtained at )30 °C): Methyl: 52.68(d) 2J(31P–
13C) ¼ 5.14 Hz, Carbonyls: d (2E) ¼ 193.4, d (4A) ¼ 192.9,
d (2B/2C) ¼ 191.8, d (D) ¼ 191.3(d, 3J(31P–13C) ¼ 9.23
Hz), d (2B/2C) ¼ 189.1; 13C(1H): Methyl: 52.69(qd),
1J(13C–1H) ¼ 147.47 Hz, 2J(31P–13C) ¼ 5.1 Hz.
3
3
1
NMR Data. H: )17.39 (d, w), 31P: )23.43(s), 31P(1H):
)23.47(m) 13C: Aromatics: 125.34(s,Cp), 126.23(s, Cp),
127.06(s, Cm), 127.73(s, Cm), 128.98(s, Co), 130.11(s,
Co), 150.98(s, Ci); COÕs: 184.27(m), 185.66(s), 189.18(s),
3.5. Crystallographic studies
190.04(s), 190.8(s), 192,58(s), 193.52(s). 19F data: Fortho
d ¼ )127.35(d, 6F) 3J(19Fo–19Fm) ¼ 18.66 Hz Fpara
:
:
Crystals of 1–4 were grown from CH2Cl2 solutions.
Details of the data collection and structure refinement

3410
M. Gabriela Ballinas-Lꢀopez et al. / Polyhedron 22 (2003) 3403–3411
Table 4
Data collection parameters and structure refinement procedures for compounds 1–4
Compound
1
2
3
4
Formula
C
29H4F15O11PRU4
C19H15O11PRU4
854.56
C14H13O14PRU4
840.49
C17H19O14PRu4
882.57
Molecular weight
Crystal size (mm)
Crystal color and habit
System
1248.57
0.5 ꢁ 0.4 ꢁ 0.4
orange prism
monoclinic
P21/n
0.45 ꢁ 0.31 ꢁ 0.11
red orange blocks
monoclinic
P21/C
0.3 ꢁ 0.4 ꢁ 0.4
red orange prisms
triclinic
0.5 ꢁ 0.4 ꢁ 0.4
red orange blocks
triclinic
ꢂ
P1
ꢂ
P1
Space group
ꢁ
a (A)
ꢁ
12.701(3)
13.192(3)
21.560(4)
90
9.803(2)
12.460(2)
22.300(4)
90
11.241(2)
13.607(3)
16.648(3)
80.02(3)
79.36(3)
86.94(3)
2464.2(8)
4
9.821(2)
11.049(2)
14.195(3)
83.21(3)
88.60(3)
66.47(3)
1401.9(5)
2
b (A)
ꢁ
c (A)
a (°)
b (°)
c (°)
90.13(3)
90
100.26(3)
90
3
ꢁ
V (A )
3612.4(14)
4
2.296
2680.3(8)
4
2.118
z
qcalc (Mg mꢀ3
F(000)
)
2.266
1600
2.091
848
2368
1632
ꢁ
c (Mo Ka) (A)
l (Mo Ka) (mmꢀ1
2h range (°)
Temperature (K)
hmin/hmax
0.71073
1.820
4–50
0.71073
2.321
4–50
0.71073
2.531
4–50
0.71073
2.230
4–50
)
293(2)
)15/0
0/15
293(2)
0/11
0/14
293(2)
)13/13
)15/16
0/19
293(2)
)11/11
)12/13
0/16
kmin/kmax
lmin/lmax
)25/25
6651
5123
)26/26
6124
4048
Measured reflections collected
Observed reflections (F > 4r(F))
Rint
7716
6621
4912
4172
0.0177
0.986
0.001
1.083
GOF on F2
1.074
0.0324
0.0819
1.047
0.0588
0.2060
R1[F > 4r(F)]
0.0311
0.08940
0.0384
0.1057
wR2 (on F2 all data)a
procedures are summarized in Table 4. Data sets were
collected in an Enraf-Nonius CAD4 diffractometer.
The samples were mounted in capillary tubes. All
structures were solved by direct methods (SHELXS-93)
[23]. All non-hydrogen atoms were found in Fourier
maps and refined anisotropically. Hydrogen atoms
from phenyl and methyl groups were fixed in idealized
positions and their positions refined. In the case of
compounds 1, 2 and 3, hydrogen atoms of the hydrides
were localized in Fourier maps and their coordinates
refined. In the case of compound 2, there is an occu-
pational disorder in the phenyl ring of the phosphine
so occupancy was refined yielding a 51% and 49%
occupancy for each position. After this refinement, the
carbon atoms of the ring were successfully refined an-
isotropically.
UK (fax: +44-1223-336063; e-mail: deposit@ccdc.cam.
ac.uk or www: http://www.ccdc.cam.ac.uk).
Acknowledgements
M.G.B.L. thanks Conacyt for the award of a grant.
ꢀ
Thanks are given to Marco Antonio Leyva and Vıctor
M. Gonzalez for their assistance with the X-ray struc-
ꢀ
tures and NMR spectra, respectively.
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