Hydrolytic disproportionation of coordinated white phosphorus in [CpRu(dppe)(η1-P4)]PF6 [dppe = 1,2-bis(diphenylphosphino)ethane]

Article abstract of DOI:10.1016/j.jorganchem.2006.05.049

The reaction of [CpRu(dppe)Cl] (1), dppe = 1,2-bis(diphenylphosphino)ethane, with one equivalent of P₄ in the presence of TlPF₆ affords the stable complex [CpRu(dppe)(η¹-P₄)]PF₆ (2) which contains the

Full text of DOI:10.1016/j.jorganchem.2006.05.049

Journal of Organometallic Chemistry 691 (2006) 3931–3937
www.elsevier.com/locate/jorganchem
Hydrolytic disproportionation of coordinated white phosphorus
in [CpRu(dppe)(g1-P4)]PF6 [dppe = 1,2-bis(diphenylphosphino)ethane]
a
b
a
a,
*
Massimo Di Vaira , Maurizio Peruzzini , Stefano Seniori Costantini , Piero Stoppioni
a
`
Dipartimento di Chimica, Universita di Firenze, via della Lastruccia n. 3, 50019 Sesto Fiorentino, Firenze, Italy
b
ICCOM CNR, via Madonna del Piano n. 10, 50019 Sesto Fiorentino, Firenze, Italy
Received 8 May 2006; received in revised form 30 May 2006; accepted 30 May 2006
Available online 9 June 2006
Abstract
The reaction of [CpRu(dppe)Cl] (1), dppe = 1,2-bis(diphenylphosphino)ethane, with one equivalent of P4 in the presence of TlPF6
affords the stable complex [CpRu(dppe)(g1-P4)]PF6 (2) which contains the tetrahedral P4 molecule g1-bound to the metal. The tetraphos-
phorus ligand readily reacts with water upon mixing acetone or THF solutions of the complex with excess water. The complexes
[CpRu(dppe)(PH3)]PF6 (5) and [CpRu(dppe){P(OH)3}]PF6 (6), identified among the hydrolysis products, contain the PH3 molecule
and, respectively, the unstable P(OH)3 tautomer of the phosphorous acid bound to the CpRu(dppe) fragment. In CH2Cl2 the coordi-
nated P(OH)3 molecule in 6 easily yields the compound [CpRu(dppe){PF(OH)2}]PF2O2 (8), via hydrolysis of the hexafluorophosphate
anion and F/OH substitution in the coordinated P(OH)3 molecule. All the compounds have been characterized by elemental analyses and
NMR measurements. The crystal structures of 2 and 8 have been determined by X-ray diffraction methods.
ꢀ 2006 Elsevier B.V. All rights reserved.
Keywords: Ruthenium cyclopentadienyl complexes; Bidendate ligands; White phosphorus coordination; White phosphorus disproportionation; Crystal
structures
1. Introduction
hydrolysis in exceedingly mild conditions to yield quantita-
tively PH3, which remains coordinated to the metal in the
complexes [CpRu(PPh3)2(PH3)]Y (Y = PF6, CF3SO3), in
addition to phosphorous acid and oxygenated compounds
[1]. The [CpRu(PPh3)2Cl] complex is known to promote
and/or catalyze a number of conversions and to allow the
rapid assembly of complex molecules with high selectivity
[9]. Such reactions are highly affected by the nature of the
two phosphorus donors; for example, the use of a bidentate
ligand such as dppe [dppe = 1,2-bis(diphenylphosph-
ino)ethane], instead of triphenylphosphine, prevents the
condensation of allylic alcohols and terminal alkynes, pre-
sumably due to the reluctance of the dppe ligand to disso-
ciate from the ruthenium center [10]. With the aim to
obtain more information on the coordinating properties
of the P4 cage and on the remarkable reactivity of the coor-
dinated species, we have investigated the behaviour of the
molecule in the presence of [CpRu(dppe)Cl] (1) thus prob-
ing the effect of a chelating diphosphine in the hydrolysis of
coordinated white phosphorus.
We have recently found that white phosphorus readily
binds to the CpRu(PPh3)2 fragment yielding the com-
pounds [CpRu(PPh3)2(g1-P4)]Y (Y = PF6, CF3SO3) (3),
which contain the P4 tetrahedral molecule g1 coordinated
to the metal [1]. Such complexes, at variance with the few
unstable P4 compounds previously described [2–5], possess
good stability being then suitable for investigating the reac-
tivity of the coordinated P4 molecule and comparing the
chemistry of the coordinated cage with that of the free mol-
ecule. This topic deserves particular interest in view of the
central role played in the synthesis of organophosphorus
derivatives by the P4 molecule [6,7], which is generally acti-
vated only in harsh conditions [8]. Solutions of
[CpRu(PPh3)2(g1-P4)]Y (Y = PF6, CF3SO3) (3) undergo
*
Corresponding author. Tel.: +39 055 4573281.
E-mail addresses: mperuzzini@iccom.cnr.it (M. Peruzzini), piero.stop-
pioni@unifi.it (P. Stoppioni).
0022-328X/$ - see front matter ꢀ 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2006.05.049

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M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
2. Results and discussion
The X-ray structure of the complex cation in 2 is shown
in Fig. 1 and values of selected bond distances and angles
are given in Table 2. The P–Ru–P angle formed by the
phosphine donor atoms is considerably smaller, by 21.4ꢁ,
than that formed by the triphenylphosphine donors in 3,
due to the restraint set by the chelate ligand in the present
The reaction of the dppe ruthenium complex [CpRu(dp-
pe)Cl] (1) with the P4 molecule, in the presence of TlPF6 or
AgCF3SO3, differs from that of the bis-triphenylphosphine
[CpRu(PPh3)2Cl] complex, which yields readily and quan-
titatively the compounds [CpRu(PPh3)2(g1-P4)]Y (Y =
PF6 or CF3SO3) (3), irrespectively of the halide scavenger
used [1]. In the case of 1, while AgCF3SO3 leads predomi-
nantly to the reduction of the silver ion by white phospho-
rus, TlPF6, whose cation has no oxidizing properties,
slowly brings about precipitation of TlCl and coordination
of the P4 molecule, yielding [CpRu(dppe)(g1-P4)]PF6 (2)
within a few days (Scheme 1). Such behaviour is attributed
to reduced mobility of the chloride ion in [CpRu(dppe)Cl],
with respect to [CpRu(PPh3)2Cl]. Compound 2 exhibits
a good stability and in this regard it behaves as the
related [CpRu(PPh3)2(g1-P4)]Y (3) [1] and [Cp*Ru(dppe)-
(g1-P4)]BPh4 (4) [11] derivatives. The P4 molecule is firmly
coordinated to the metal in solution, yielding a temperature-
invariant first-order A2CM3 spin pattern in the 31P NMR
spectrum. The four phosphorus atoms of the cage yield
the CM3 part of the resonances with the metal-coordinated
PC atom featuring a quartet of triplets (Table 1) due to the
coupling to PM and PA, respectively, significantly downfield
shifted with respect to the signal of the free P4, while the
three naked P atoms yield a doublet. The chemical shift
of the naked PM phosphorus atoms is relatively close to
that exhibited by the P atoms in corresponding position
in the compounds 3 and 4.
˚
compound 2. The Ru–P(dppe) distances in 2 are 0.06 A
shorter than the Ru–P(PPh3) distances in 3, whereas the
˚
value of the Ru–P(P4) distance is only 0.01 A smaller for
2, the latter difference being possibly due to different tem-
peratures of data collection for the two structures. The P4
geometry in 2 is that of a trigonal pyramid (as it was in
˚
3), with basal bonds 0.04 A longer, in the mean, than the
P–P bonds formed by the coordinating P atom. The mean
˚
values of P–P bonds of both types are 0.02 A smaller in 2
than in 3.
When a solution of 2 in acetone or THF is treated with
excess water (1:100), hydrolysis of the P4 ligand completes
at room temperature within 2 h. The reaction, carried out
on different batches in NMR tubes, is reproducible both
regarding the nature and the amount of the various prod-
ucts obtained; among these, the new complexes [CpRu(dp-
pe)(PH3)]PF6 (5) and [CpRu(dppe){P(OH)3}]PF6 (6), as
well as phosphorous acid have been unambiguously identi-
fied. Compound 5 and H3PO3 occur in ca. 50% yield with
respect to the P4 derivative 2, while 6 forms in lower
amount (ca. 10% based on 2). The PH3 molecule in 5 and
the otherwise unstable P(OH)3 tautomer of the phospho-
rous acid, H3PO3, in 6 are bound to the CpRu(dppe) frag-
ment. The two complexes have been characterized by
PF6
P4 + TlPF
6
Ru
Ru
Ph2P
Ph2P
PM
PM
P
A
- TlCl
Cl
2
C
PPh2
PPh2
A
P
M
1
+ H O
2
PH ,
3
TlPF
6
- TlCl
PF6
PF6
PF2O2
Ru
Ru
Ru
Ph2P
Ph2P
A
Ph2P
H
H
OH
OH
OH
F
P
P
P
A
A
C
C
C
PPh2
PPh2
PPh2
A
A
A
H
OH
OH
5
6
8
+ H PO
3
3
TlPF
6
- TlCl
PF6
+ H PO
3
2
Ru
7
Ph2P
OH
H
P
A
C
PPh2
A
OH
Scheme 1.

M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
3933
Table 1
31P NMR data of the ruthenium complexes with the intact P4
a
d PA
d PC
d PM
2
3
4
75.1 (d, 2J(PA–PC) = 52.0 Hz)
ꢀ328.8 (tq, 1J(PC–PM) = 238.5 Hz)
ꢀ495.5 (d)
ꢀ487.0 (d)
ꢀ490.3 (d)
PF6
PF6
Ru
Ph2P
PM
PM
P
A
C
PPh2
A
P
M
39.0 (d, 2J(PA–PC) = 64.0 Hz)
ꢀ348.2 (tq, 1J(PC–PM) = 235.0 Hz)
Ru
Ph3P
PM
PM
P
A
C
Ph3P
A
P
M
70.4 (d, 2J(PA–PC) = 44.0 Hz)
ꢀ308.5 (tq, 1J(PC–PM) = 233.5 Hz)
PF6
Ru
PPh2
Ph2P
PM
PM
P
A
C
A
P
M
a
NMR data in (CD3)2CO solution; chemical shifts are in ppm with respect to H3PO4 as external standard. White phosphorus yields a singlet at
ꢀ526.9 ppm.
Table 2
1
˚
Selected bond lengths (A) and bond angles (ꢁ) for [CpRu(dppe)(g -
P4)]PF6 (2)
Ru–P(1)
Ru–P(2)
Ru–P(3)
P(3)–P(4)
P(3)–P(5)
2.303(1)
2.306(1)
2.254(1)
2.139(2)
2.148(2)
P(3)–P(6)
P(4)–P(5)
P(4)–P(6)
P(5)–P(6)
Ru–C(Cp)
2.147(2)
2.181(3)
2.201(2)
2.181(2)
2.189–2.242
P(1)–Ru–P(2)
P(1)–Ru–P(3)
83.16(4)
87.55(5)
P(2)–Ru–P(3)
93.17(5)
1
this regard the H coupled 31P spectrum of H3PO3 and
those of the complexes 5 and 6 have been particularly use-
ful to detect the possible presence of hydrogens directly
bound to phosphorus, since these exhibit multiplets charac-
terized by typically large P–H coupling constants [12,13].
The residual fractions of the P4 cage and of the
CpRu(dppe) fragment yield a variety of compounds which
have not been yet characterized.
Some comments seem to be appropriate about the easy
hydrolysis of the coordinated P4 molecule undergone by 2
and 3, which is intriguing, in view of the well known stabil-
ity of white phosphorus in water. Also interesting is the dif-
ferent behaviour of the compounds [CpRu(PPh3)2(g1-P4)]Y
(3), which easily react with water [1], and [Cp*Ru(dppe)(g1-
P4)]Y, which are indefinitely stable in the same conditions
[11]. Such a dichotomy might suggest that hydrolysis of 3
is favoured by the presence of the monodentate triphenyl-
phosphine, that is known to detache easily from
[CpRu(PPh3)2Cl] [14,15], while dissociation is less likely
for the chelate ligand in the dppe complexes [9]. However,
the hydrolysis undergone by 2 seems to rule out a dissocia-
tive mechanism that would involve coordination by a water
molecule replacing the phosphine. Rather, comparisons
between the crystal structures of the Cp derivatives 2 and
Fig. 1. A view of the cation in the structure of [CpRu(dppe)(g1-P4)]PF6
(2). Thermal ellipsoids are shown at the 30% probability level and
hydrogen atoms are not shown for clarity.
1
comparing the H and 31P NMR data of the hydrolyzed
samples with those of the complexes that have been inde-
pendently synthesized (see below). Likewise, the presence
of free phosphorous acid has been ascertained by consider-
ing the 31P shift of solutions containing the pure acid; in

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M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
3 [1] and that of the Cp* iron complex [Cp*Fe(dppe)(g1-
P4)](BPh4) [11] (as well as comparisons with the optimized
geometries, from quantum mechanical calculations, of the
models of Cp* ruthenium complexes corresponding to 2
and 3 – these are reported with the Supplementary material)
suggest that the higher bulkiness of Cp* compared to Cp
limits access by the water molecules to the metal coordina-
tion sphere. In an attempt to get a clue about the puzzling
hydrolysis mechanism, calculations have been performed
on models in which the region of the Ru(g1-P4) moiety in
3 was probed by an approaching water molecule. Possible
paths seem to involve, in the first stage, the close approach
of the water molecule to the region of the Ru–P(P4) bond
(which, however, implies crossing a very high energy bar-
rier). If that is accomplished, a metal hydride is formed by
dissociation of the water molecule, with a P4 phosphorus
atom still semicoordinated; simultaneously, a P–P bond of
the cage opens, due to attack on a ‘‘basal’’ phosphorus by
the OH fragment from the water molecule.
plexes [23]. The hydrogen directly bound to phosphorus
yields a doublet of triplets (d 7.45 ppm) in the H NMR
1
spectrum, characterized by the above strong 1J(H–PC) cou-
pling and a weak 3J(H–PA) one (2.0 Hz). On the other
hand, no coupling is observed for the coordinated
H3PO3, clearly showing that no hydrogen is bound to the
PC atom in that case. Such NMR data, which parallel those
of the compounds [CpRu(PPh3)2{P(OH)3}]PF6 and
[CpRu(PPh3)2{HP(OH)2}]PF6 [23], whose structures have
been determined by X-ray analyses, allow to assess unam-
biguously that the unstable tautomers P(OH)3 and
HP(OH)2 of the hypophosphorous and phosphorous acids
are stabilized by coordination through their P atom to the
ruthenium of the CpRu(dppe) fragment. The stabilization
of the pyramidal tautomers of the two acids, which are
known to occur predominantly with the tetrahedral struc-
ture [24–28], confirms the preference by the soft metal cen-
ter of the cationic CpRu(L)2 fragment (L = PPh3, 1/2dppe)
for the P atom of the acid molecule. Such coordination
mode had been observed only in two compounds
[13,29,30], before the above-mentioned report [23].
As a check on the nature of one of the hydrolysis prod-
ucts, the compound [CpRu(dppe)(PH3)]PF6 (5) has been
independently synthesized by reaction of 1 in THF with
gaseous PH3 in the presence of TlPF6. The complex, which
adds to the small group of metal PH3 derivatives [1,16–22],
is quite stable under an inert atmosphere and the PH3 mol-
ecule remains firmly coordinated to the metal in solution,
yielding a first-order A2C spin pattern in the 31P NMR
spectrum; the lower field doublet is assigned to the phos-
phorus atoms (PA) of the dppe ligand and the higher field
triplet to the phosphine atom (PC). The latter signal turns
into a quartet of triplets in the 31P–1H coupled spectrum,
the observed value of 1J(P–H) (360.0 Hz) being in the range
of those found for the [CpRu(PPh3)2(PH3)]Y complexes
(Y = PF6, CF3SO3) [1] and for tetracoordinated P–H sys-
tems [12]. The hydrogens directly bound to phosphorus
Compound 6 dissolved in CH2Cl2 decomposes within
24 h to yield a complex of formula [CpRu(dppe){P-
F(OH)2}]PF2O2 (8), which is stable under an inert atmo-
sphere and is soluble in common organic solvents. The
31P{1H} NMR spectrum of the cation exhibits an A2CX
(X = 19F) pattern with a doublet, assigned to the dppe
phosphorus atoms, and a lower field doublet of triplets.
The latter resonances exhibit a large coupling (1137 Hz),
which is typical for a P–F group, and a small one due to
the coupling with the dppe phosphorus donors. The 31P
and 19F NMR spectra exhibit also the resonances due to
the PF2Oꢀ anion [31]. The behaviour of the coordinated
2
P(OH)3 in the present dppe derivative 6 parallels that of
the same ligand in the [CpRu(PPh3)2{P(OH)3}]PF6 com-
pound (9) [23], which yields the [CpRu(PPh3)2{P-
F(OH)2}]PF2O2 product (10) by decomposition [23],
showing that the hexafluorophosphate hydrolysis leads to
substitution of an OH of the coordinated P(OH)3 ligand
by a fluorine atom, to yield the PF(OH)2 species which is
the tautomer of the extremely unstable monofluorophosph-
orous acid, HPFO(OH), detected only in small amounts in
the reactions of HPF2O [32].
1
yield in the H NMR spectrum a doublet of triplets (d
1
4.41 ppm), characterized by the large J(H–PC) coupling
mentioned above and a weak 3J(H–PA) one (2.0 Hz). With
the aim to ascertain the nature of the complexes containing
oxygenated phosphorus ligand(s), which are formed in the
hydrolysis, the complexes [CpRu(dppe){P(OH)3}]PF6 (6)
and [CpRu(dppe){HP(OH)2}]PF6 (7), have been synthe-
sized in high yields by reacting 1 with the stoichiometric
amount of the appropriate acid of phosphorus (H3PO2 or
H3PO3) in water (50%), in the presence of the stoichiome-
tric amount of TlPF6. The yellow compounds are stable
under an inert atmosphere and are soluble in common
organic solvents; compound 6 dissolved in CH2Cl2 decom-
poses in ca. 1 day (see later). The 31P NMR spectra of the
cations in 6 and 7 exhibit an A2C pattern with the lower
field triplet assigned to the phosphorus atom (PC) of the
acid (hypophosphorous or phosphorous) and the higher
field doublet to the dppe atoms (PA). The triplet of the
hypophosphorous derivative 7 is doubled in the 31P–H cou-
pled spectrum, showing that only one hydrogen is bound to
The structure of 8 has been determined by X-ray diffrac-
tion. A view of the [CpRu(dppe)(PF(OH)2)]+ complex cat-
ion is shown in Fig. 2 and values of selected bond distances
and angles are given in Table 3. The Ru–P distances formed
by the phosphine donors, slightly shorter than in 2, are ca.
˚
0.07 A shorter than the distances formed by the PPh3 phos-
phorus atoms in 10 [23], while the distance to the metal
˚
formed by the PF(OH)2 phosphorus in 8 is only 0.014 A
shorter than in 10. The value of the P–Ru–P angle formed
by the dppe ligand in 8 is closely similar to that found for 2
and is 18.7ꢁ smaller than the angle formed by the triphenyl-
phosphine P atoms in 10. In the PF(OH)2 ligand of 8,
apparently less affected by disorder than the analogous
group in 10, the atomic site considered to be 100% F forms
1
the P atom; the observed value of J(P–H) (418.0 Hz) is
similar to that found for [CpRu(PPh3)2{HP(OH)2}]Y com-

M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
3935
and 31P NMR spectra were measured on a Varian Gemini
g300bb spectrometer operating at 300 MHz (1H),
282.28 MHz (19F) and 121.46 MHz (31P). Chemical shifts
are relative to tetramethylsilane (1H), to CFCl3 (19F) and
to H3PO4 85% (31P) as external standards at 0.00 ppm; cou-
pling constants are given in Hertz. Microanalyses were
done by the Microanalytical Laboratory of the Depart-
ment of Chemistry of the University of Firenze. [CpRu(dp-
pe)Cl] (1) was prepared according to the literature method
[34]. H3PO2 and H3PO3 water solutions and the ligand
dppe (Aldrich) were used as received.
3.2. Synthesis of the complexes
3.2.1. [CpRu(dppe)(g1-P4)]PF6 Æ CH2Cl2 (2)
A
suspension of [CpRu(dppe)Cl] (1) (300 mg,
0.50 mmol) and of TlPF6 (175 mg, 0.50 mmol) in a mixture
of CH2Cl2 (20 cm3) and THF (20 cm3) was slowly added at
room temperature to a solution of white phosphorus
(87 mg, 0.70 mmol) dissolved in THF (20 cm3). The result-
ing slurry was stirred at room temperature for 5 days; the
precipitated TlCl was filtered off and the solvent evapo-
rated under reduced pressure. The orange solid was washed
twice with toluene (5 cm3), dried under vacuum and recrys-
tallized from CH2Cl2–hexane. Yield: 300 mg (65%). Anal.
Calc. for C32H31Cl2F6P7Ru: C, 41.85; H, 3.41. Found: C,
1
41.75; H, 3.50%. H NMR [d, (CD3)2CO, 20 ꢁC]: 7.80–
7.20 (20H, m, Ph), 5.43 (5H, s, Cp), 2.86 (4H, mbr,
2
CH2). 31P{1H} NMR: 75.1 (2P, d, J(PA–PC) = 52.0, PA),
1
ꢀ143.1 (1P, sept, J(P–F) = 709.5, PF6), ꢀ328.8 (1P, tq,
1J(PC–PM) = 238.0, PC), ꢀ495.5 (3P, d, PM).
Fig. 2. A view of the cation in the structure of [CpRu(dppe){P-
F(OH)2}]PF2O2 (8), with 30% probability ellipsoids.
3.2.2. [CpRu(dppe)(PH3)]PF6 (5)
PH3 was gently bubbled for 10 min through a solution
of [CpRu(dppe)Cl] (1) (300 mg, 0.50 mmol) and of TlPF6
(175 mg, 0.50 mmol) in a mixture of CH2Cl2 (20 cm3) and
THF (20 cm3). Afterwards the reaction flask was isolated
and stirred at room temperature for 20 h; the precipitated
TlCl was filtered off and yellow microcrystals of 5 were
obtained by evaporating the solvent under reduced pres-
sure. The solid was recrystallized from CH2Cl2–hexane.
Yield: 250 mg (68%). Anal. Calc. for C31H32F6P4Ru: C,
Table 3
˚
Selected bond lengths (A) and bond angles (ꢁ) for [CpRu(dppe){P-
F(OH)2}]PF2O2 (8)
Ru–P(1)
Ru–P(2)
2.228(2)
2.289(2)
2.286(1)
2.623(6)
2.601(6)
P(3)–O(1)
P(3)–O(2)
P(3)–O(3)
Ru–C(Cp)
1.567(4)
1.564(4)
1.576(3)
Ru–P(3)
O(1)ꢁ ꢁ ꢁO(4)a
2.226–2.248
O(2)ꢁ ꢁ ꢁO(3)a
P(2)–Ru–P(3)
P(1)–Ru–P(2)
a
83.52(5)
94.24(5)
P(1)–Ru–P(3)
89.08(5)
1
50.07; H, 4.34. Found: C, 49.83; H, 4.40%. H NMR [d,
(CD3)2CO, 20 ꢁC]: 7.80–7.20 (20H, m, Ph), 4.87 (5H, s,
Cp), 4.41 (3H, dt, 1J(H–PC) = 360.0, 3J(H–PA) = 2.0,
PH3), 2.86 (4H, mbr, CH2). 31P{1H} NMR: 80.1 (2P, d,
2J(PA–PC) = 41.0, PA), ꢀ105.4 (1P, t, PC), ꢀ143.1 (1P,
Sites O(3) and O(4), belonging to the PF2Oꢀ2 anion, were both assigned
2/3 O and 1/3 F population parameters.
1
with the other two (oxygen) sites F–P–O angles which are
sept, J(P–F) = 709.0, PF6).
7.4ꢁ smaller, in the mean, than the O–P–O angle.
3.2.3. [CpRu(dppe){P(OH)3}](PF6) (6)
To
3. Experimental
a
solution of [CpRu(dppe)Cl] (1) (300 mg,
0.50 mmol) and of TlPF6 (175 mg, 0.50 mmol) in a mix-
ture of CH2Cl2 (20 cm3) and THF (20 cm3) was added
at room temperature one equivalent of H3PO3 (50% water
solution). The resulting slurry was stirred at room temper-
ature for 4 h; in the meantime the orange colour of the
solution faded to light yellow. The precipitated TlCl was
3.1. General
All reactions and manipulations were performed under
an atmosphere of dry oxygen-free argon. The solvents were
purified according to standard procedures [33]. The 1H, 19
F

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M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
Table 4
filtered off and the solvent evaporated under reduced pres-
sure. The solid was washed twice with ether (5 cm3) and
recrystallized from CH2Cl2–hexane. Yield: 330 mg (83%).
Anal. Calc. for C31H32F6O3P4Ru: C, 47.04; H, 4.08.
Found: C, 46.80; H, 4.15%. 1H NMR [d, (CD3)2CO,
20 ꢁC]: 7.90–7.20 (20H, m, Ph), 5.21 (5H, s, Cp), 2.91
(4H, mbr, CH2). 31P{1H} NMR: 138.1 (1P, t, 2J(PC–
PA) = 59.0, PC), 82.9 (2P, d, PA), ꢀ143.1 (1P, sept,
1J(P–F) = 709.0, PF6).
Crystal data and structure refinement parameters for compounds
[CpRu(dppe)(g1-P4)]PF6 (2) and [CpRu(dppe)(PF(OH)2)](PF2O2) (8)
Compound
2
8
Formula
Formula
weight
C32H31Cl2F6P7Ru
918.33
C31H31F3O4P4Ru
749.51
Crystal system
Space group
Orthorhombic
Pbc21
12.837(1)
14.773(1)
19.263(1)
90
Orthorhombic
Pbca
a
˚
a (A)
16.077(2)
18.707(2)
20.920(2)
90
90
90
6292(1)
8
0.06 · 0.40 · 0.60
0.755
293(2)
60821
˚
b (A)
˚
c (A)
3.2.4. [CpRu(dppe){HP(OH)2}]PF6 (7)
a (ꢁ)
b (ꢁ)
c (ꢁ)
The light yellow compound has been obtained through
the same procedure as the phosphorous acid derivative 6
by adding to a solution of 1 and the chloride scavenger
the stoichiometric amount of H3PO2 in 50% water solution.
Yield: 85%. Anal. Calc. for C31H32F6O2P4Ru: C, 48.00; H,
90
90
3
˚
V (A )
3653.1(5)
4
0.15 · 0.20 · 0.40
0.938
150(2)
35173
Z
Crystal size (mm)
l(Mo Ka) (mmꢀ1
T (K)
Reflection collected
Independent
)
1
4.16. Found: C, 47.75; H, 4.25%. H NMR [d, (CD3)2CO,
20 ꢁC]: 7.45 (1H, dt, 1J(H–PC) = 418.0, 3J(H–PA) = 2.0,
HP(OH)2), 7.80–7.20 (20H, m, Ph), 5.03 (5H, s, Cp), 2.75
(4H, mbr, CH2). 31P{1H} NMR: 146,1 (1P, t, 2J(PC–
7385 (0.0613)
6400 (0.0454)
reflections (Rint
Number of
)
1
433 (1)
395
PA) = 53.0, PF), 83.1 (2P, d, PA), ꢀ143.1 (1P, sept, J(P–
parameters (restraints)
R1, wR2 [I > 2r(I)]
R1, wR2 (all data)
Goodness-of-fit
a
F) = 709.0, PF6).
0.0351, 0.0742
0.0652, 0.0743
0.882
0.0677, 0.1759
0.0987, 0.1946
1.060
3.2.5. [CpRu(dppe){PF(OH)2}]PF2O2 (8)
[CpRu(dppe)(P(OH)3)]PF6 (6) (240 mg, 0.3 mmol) was
dissolved in CH2Cl2 (20 cm3) and the solution was left at
room temperature for 20 h. The yellow complex was
obtained by adding hexane (20 cm3). Yield: 95 mg (42%).
Anal. Calc. for C31H31F3O4P4Ru: C, 49.67; H, 4.17.
Alternative setting of Pca21, No. 29.
value, for the chosen enantiomer] [38]. In the structure of 8
the oxygen atoms of the PF(OH)2 group were identified on
the basis of the hydrogen bonds formed with sites of the
anion (and in view of the slightly shorter P–O distances
than the P–F one). The positional parameters of the
PF(OH)2 hydrogen atoms were refined with the O–H dis-
1
Found: C, 49.45; H, 4.21%. H NMR (d, CDCl3, 20 ꢁC):
7.70–7.10 (20H, m, Ph), 4.98 (5H, s, Cp), 2.73 (4H, m,
CH2). 31P{1H} NMR: 141,9 (1P, dt, 1J(PC–F) = 1137.5,
1
2J(PC–PA) = 63, PC), 83.1 (2P, d, PA), ꢀ13.8 (1P, t, J(P–
tances restrained to a unique value ðUH ¼ 1:5UeqÞ. In the
F) = 961.1, PF2O2). 19F NMR: 3.1 (1F, d, 1J(F–
PC) = 1138.1, PF(OH)2), ꢀ83.1 (2F, d, 1J(F–P) = 962.5,
PF2O2).
O
tetrahedral PF2Oꢀ anion of 8 one of the peripheral sites,
2
which formed (i) a distance to phosphorus distinctly longer
(by 0.10 A) than those formed by the other sites and (ii)
˚
3.3. X-ray crystallography of [CpRu(dppe)(g1-P4)]PF6
(2) and [CpRu(dppe){PF(OH)2}]PF2O2 (8)
angles at phosphorus with the other three sites smaller than
the tetrahedral value, was considered to be occupied only
by fluorine, consistently with the literature data [39]. The
second fluorine atom in the anion was considered to be
equally distributed among the other three sites. Programs
used in the crystallographic calculations included PARST
[40] and ORTEP [41].
X-ray diffraction data for 2, as dichloromethane solvate,
and 8 were collected on an Oxford Diffraction Xcalibur 3
CCD
diffractometer,
using
Mo
Ka
radiation
˚
(k = 0.71069 A). Crystal data and the main data collection
and structure refinement parameters are given in Table 4.
Lattice constants were obtained from the setting angles
of 3990 (2) and 6268 (8) reflections in the h range 3–16ꢁ.
Both intensity data sets were corrected for absorption by
a multi-scan procedure [35]. The structures were solved
by direct methods, with SIR-97 [36], and were refined by
full-matrix least-squares on F2 values [37]. All non-hydro-
gen atoms were refined anisotropically. All hydrogens
bound to carbons were placed in idealized positions, each
riding on the respective carrier atom, with its temperature
factor linked to the overall U of the latter. The absolute
structure, in view of the acentric space group of 2, could
be assigned on the basis of Flack’s test [ꢀ0.05(3) parameter
Acknowledgement
Financial support by the Italian Ministero
`
dell’Istruzione, dell’Universita e della Ricerca is gratefully
acknowledged.
Appendix A. Supplementary material
CCDC reference numbers 602500 and 602501 con-
tain the supplementary crystallographic data for 2 and
8, respectively. These data can be obtained free of charge
from The Cambridge Crystallographic Data Centre via

M. Di Vaira et al. / Journal of Organometallic Chemistry 691 (2006) 3931–3937
3937
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