Investigation of the reactivity of the phosphorus-hydrogen bond in Cp′RuL1L2Cl complexes with diphenylphosphine ligands

Article abstract of DOI:10.1016/S0022-328X(99)00191-6

Products resulting from the oxidation, chlorination, hydrolysis and ethanolysis of Cp*Ru(PHPh₂)₂Cl (1) are described. Chlorination of the P-H bond in 1 allowed isolation of Cp*Ru(PClPh₂)₂Cl (6) and there is spectroscopic evidence for the presence of Cp*Ru(PClPh₂)(PHPh₂)Cl (5). Hydrolysis of compounds 1 and 5 gave a dihydride complex [Cp*Ru(H)₂(OPPh₂)(POHPh₂)] (13) and cationic species [Cp*Ru(PHPh₂)₃]Cl (14) and [Cp*RuPOHPh₂(PHPh₂)₂]Cl (15). Formation of 14 was confirmed by the synthesis of [Cp*Ru(PHPh₂)₃]OTf (14′) through intermediate [Cp*Ru(MeCN)(PHPh₂)₂]OTf (16) which was obtained from the addition of AgOTf to 1 in MeCN solution. Reaction of (Cp*RuCl₂)₂ (12) in EtOH with two equivalents of PHPh₂ gave compound 1 and ethanolysis products Cp*Ru(POEtPh₂)(PHPh₂)Cl (18) and Cp*Ru(POEtPh₂)₂Cl (11), while reaction of 12 with diphenylphosphine oxide (OPHPh₂) led to the formation of Cp*Ru(POHPh₂)₂Cl (7), which can either be converted to hydride compound Cp*Ru(H)(Cl)[(OPPh₂)(POHPh₂)] (10) or an aromatic ring of its coordinated phosphine will bind to the electrophilic [Cp*Ru]⁺ fragment to give compound [Cp*Ru[μ-(η⁶-C₆H ₅)POHPh]Cp*Ru(POHPh₂)Cl]Cl (8). Based on ¹H- and ³¹P-NMR spectroscopic data, compounds with two different P-donor ligands have also been prepared, including Cp*Ru(POHPh₂)(PHPh₂)Cl (9), [Cp*Ru(POHPh₂)₂(PHPh₂)]OTf (17) and Cp*Ru(POHPh₂)(POEtPh₂)Cl (19). According to NMR observations, a free radical mechanism is proposed for the chlorination and oxidation reactions. Crystal structures are provided for complexes 6, 13 and 18, and a related cationic Cp complex [CpRu(POHPh₂)(PHPh₂)₂]Cl (20).

Full text of DOI:10.1016/S0022-328X(99)00191-6

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 585 (1999) 68–82
Investigation of the reactivity of the phosphorusꢀhydrogen bond
in Cp%RuL1L2Cl complexes with diphenylphosphine ligands
Roma´n Torres-Lubia´n a,1, M. Jesu´s Rosales-Hoz a, Atta M. Arif b, Richard D. Ernst b,
M. Angeles Paz-Sandoval a,*
a Departamento de Qu´ımica, Centro de In6estigacio´n y de Estudios A6anzados del Instituto Polite´cnico Nacional, Apartado 14-740, Mexico,
D.F. 07000, Mexico
b Department of Chemistry, Uni6ersity of Utah, Salt Lake City, UT 84112, USA
Abstract
Products resulting from the oxidation, chlorination, hydrolysis and ethanolysis of Cp*Ru(PHPh2)2Cl (1) are described.
Chlorination of the PꢀH bond in 1 allowed isolation of Cp*Ru(PClPh2)2Cl (6) and there is spectroscopic evidence for the presence
of Cp*Ru(PClPh2)(PHPh2)Cl (5). Hydrolysis of compounds 1 and 5 gave a dihydride complex [Cp*Ru(H)2(OPPh2)(POHPh2)] (13)
and cationic species [Cp*Ru(PHPh2)3]Cl (14) and [Cp*RuPOHPh2(PHPh2)2]Cl (15). Formation of 14 was confirmed by the
synthesis of [Cp*Ru(PHPh2)3]OTf (14%) through intermediate [Cp*Ru(MeCN)(PHPh2)2]OTf (16) which was obtained from the
addition of AgOTf to 1 in MeCN solution. Reaction of (Cp*RuCl2)2 (12) in EtOH with two equivalents of PHPh2 gave compound
1 and ethanolysis products Cp*Ru(POEtPh2)(PHPh2)Cl (18) and Cp*Ru(POEtPh2)2Cl (11), while reaction of 12 with
diphenylphosphine oxide (OPHPh2) led to the formation of Cp*Ru(POHPh2)2Cl (7), which can either be converted to hydride
compound Cp*Ru(H)(Cl)[(OPPh2)(POHPh2)] (10) or an aromatic ring of its coordinated phosphine will bind to the electrophilic
[Cp*Ru]+ fragment to give compound [Cp*Ru[m-(h6-C6H5)POHPh]Cp*Ru(POHPh2)Cl]Cl (8). Based on 1H- and 31P-NMR
spectroscopic data, compounds with two different P-donor ligands have also been prepared, including Cp*Ru(POHPh2)(PHPh2)Cl
(9), [Cp*Ru(POHPh2)2(PHPh2)]OTf (17) and Cp*Ru(POHPh2)(POEtPh2)Cl (19). According to NMR observations, a free radical
mechanism is proposed for the chlorination and oxidation reactions. Crystal structures are provided for complexes 6, 13 and 18,
and a related cationic Cp complex [CpRu(POHPh2)(PHPh2)2]Cl (20). © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Ruthenium; Pentamethylcyclopentadienyl; Cyclopentadienyl; Diphenylphosphine
giving the corresponding Cp*M(H)(Cl)(PPh2)(PMe3)
[M=Mo, W] and Cp*TaMe(PPh2)(h2-C2H4), respec-
tively [2]; or through HCl elimination from complexes
CpMCl(HPR2)(CO)2 or CpMH(ClPR2)(CO)2 (M=
Mo, W; R=alkyl, aryl) [3] to give CpM(PR2)(CO)2. It
has been shown that these species can be isolated
because of the 1,2-positioning of the hydrogen and
chlorine atoms.
In contrast, there is a paucity of information on
ruthenium species; while Ru(PHRPh)4Cl2 (R=H [4],
Ph [5]) complexes have been reported, there are no
reports in the literature on reactions of the PꢀH bond
in secondary or primary phosphines complexed with
ruthenium. We recently reported the synthesis, proper-
ties and crystal structures of pentamethylcyclopentadi-
1. Introduction
Significant reactivity of the PꢀH bond has been es-
tablished in early transition metal complexes containing
secondary and primary phosphines. In some cases, sim-
ple loss of H occurs, leading to bridging phosphides [1].
The formation of terminal phosphides has been ob-
served through the oxidative addition of PHPh2 to
complexes, such as Cp*MoCl(N2)(PMe3)2, Cp*W(H)-
(Cl)(PMe3)(h2-CH2PMe2) and Cp*Ta(Me)2(h2-C2H4),
* Corresponding author. Fax: +525-7477-113.
E-mail address: mpaz@mail.cinvestav.mx (M.A. Paz-Sandoval)
1 Permanent address: CIQA, Blvd Ing. Enrique Reyna 140, Saltillo,
Coahuila 25100, Mexico.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00191-6

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
69
enylꢀ and cyclopentadienylꢀruthenium (II) diphenyl-
phosphine complexes (C5R5)Ru(PHPh2)2Cl (R=Me,
1; R=H, 2) and (C5R5)Ru(PHPh2)(PPh3)Cl (R=Me,
3; R=H, 4) [6] and we now present a study of the
chemistry of the PꢀH bond for compounds 1 and 3.
Preliminary results on the Cp analogous complexes 2
and 4 revealed that the disubstituted compounds 1
and 2 are more reactive than the corresponding com-
plexes with two different P-donor ligands, such as 3
and 4, respectively, due to the presence of two PꢀH
bonds.
The focus of this study is on the reactivity of the
PꢀH bond in coordinated secondary phosphine com-
plexes of ruthenium, with a goal of obtaining a more
detailed understanding of how the chemistry of such
species might be changed, and complicated, by the
presence of the more reactive PꢀH bonds. As far as
we are aware, this is the first attempt to gain an
understanding of the reactivity of the PꢀH bond in a
ruthenium complex. The results we have obtained dif-
fer significantly from those obtained in secondary
phosphine complexes of Mo, W, Ta, Ir or Rh, and
thus provide useful complementary information on
the chemical behavior of the rarely used secondary
phosphine ligands. In addition, the results serve as a
guide to the effects that reaction conditions (solvent,
inert atmosphere, etc.) will have on product distribu-
tions. In this paper we are more concerned in under-
standing the chemistry of the starting materials, rather
than to obtain efficient methods of synthesis. We are
also interested in learning how readily side products
are formed, their structures and behaviour, so that
one could then design and optimize subsequent stud-
ies accordingly. The chemistry of 1 with chloroform,
atmospheric oxygen, ethanol and water turns out to
be quite versatile, affording new Cp*Ru(II) and
Cp*Ru(IV) compounds.
3.66 h a ratio of 0.7:1:0.04 for 5, 6 and 1, respec-
tively, was observed2.
A similar experiment, now with the addition of a
trace of 1,4-benzoquinone, revealed no evidence of
any reaction, suggesting the involvement of free radi-
cals in the previous reaction. Reaction of 1 with DBN
in CD2Cl2 revealed no chlorination of the PꢀH bond
even after 70 days at r.t.
(b) In contrast, in the absence of DBN, reaction of
1 with CDCl3 and air in an open NMR tube led to a
complex mixture (Scheme 1) after 30 days with the
formation of the following species: 6, 7 [Cp*Ru-
(POHPh2)2Cl] and
8
{[Cp*Ru[m-(h6-C6H5)POHPh]-
Cp*Ru(POHPh2)Cl]Cl} whose identities were confi-
rmed through their isolation from other reactions
(vide infra)3. Diphenylphosphonic acid (OPOHPh2,
31P l=33.2 ppm) and compounds 5, 9 [Cp*RuCl-
(POHPh2)(PHPh2)] and 10 {Cp*Ru(H)(Cl)[(OPPh2)-
(POHPh2)]} (Scheme 1) are also proposed to be
present, based on 1H- and 31P-NMR spectroscopic
data. Furthermore, it was demonstrated that 7 is a
precursor of 10. The intramolecular oxidative addition
for 7 occurs slowly, giving after 6.25 h in CDCl3
a
mixture of the monohydride compound 10 and com-
pound 7 in a 1:2 ratio, respectively.
(c) Considering the adjacent positions of the chlo-
rine and hydrogen atoms in compound 1, we decided
to check if an elimination of HCl could occur, pre-
sumably yielding a terminal phosphide complex in the
absence of a chlorinated solvent. An experiment in an
open NMR tube involving compound 1 in deuterated
toluene was found to lead only to traces of com-
pounds 5, 6 and 9, which in contrast could easily be
formed in the presence of chloroform.
Even after 7 h at 100°C, compound 1 had under-
gone little change, while addition of 1.5 equivalents of
Et3N and heating at 100°C for 27 h gave, in traces,
the same species 5, 6 and 9, along with diphenylphos-
phine oxide, OPHPh2 (31P l=19 ppm). Finally, after
70 h at 100°C an insoluble dark material was found,
along with the OPHPh2.
2. Results and discussion
2 The reaction after 20 min at room temperature showed the
following signals [relative intensities]: 31P l=37.0, s, [1] 1; 34.6 (d, 50
Hz), 130.2 (d, 48 Hz), [1], 5; 132.3, s, [0.25], 6; 20.0, s, [0.12] and
traces at 97.5, d; 80.5, s; 67.5, d; 37.8 (d, 23 Hz); 30.5 (d, 37.8 Hz);
21.8, s; 17.5, s. The minor species were not assigned. The reaction
after 3.66 h at room temperature showed signals at: 31P-NMR
l=37.0, s, [1], 1; 34.6 (d, 48 Hz), 130.1 (d, 48 Hz), [17], 5; 132.4, s,
[24], 6; 80.3, s, [0.7]; 37.8 (d, 25.3 Hz) [0.4]; 17.4, s, [0.43]; −2.35, s,
[0.4] and signals found in traces at: 28.9, s; 67.5, d; 80.6, s; 110.8, s;
119.7 (d, 25.3 Hz)].
1
2.1. H- and 31P-NMR studies of compound Cp*Ru(P-
HPh2)2Cl (1)
(a) On combining compound 1 in a sealed NMR
tube with CDCl3 and 1.5 equivalents of DBN (1,5-
diazabicyclo[4.3.0]non-5-ene), the formation of com-
pounds Cp*Ru(PHPh2)(PClPh2)Cl (5) and Cp*Ru-
(PClPh2)2Cl (6) took place by successive chlorin-
ation of both PꢀH bonds (Scheme 1). Prior to the
complete transformation of 1 to 6 after 32 h at room
temperature (r.t.), several species were detected by
31P-NMR spectroscopy. Except for 5, the other spe-
cies were formed in only trace quantities, and after
3 The reaction after 10 days at room temperature showed basically
starting material 1 by 31P-NMR: l=37.2 ppm [1] and peaks in lower
quantities for compounds at °: 33.9, (OH)P(O)Ph2, [0.8]; 130.4 (d, 48
Hz), 34.7 (d, 48 Hz), 5, [0.7]; 130.2 (d, 53 Hz), 36.3 (d, 53 Hz), 9, [0.5];
9.4, s, 10, [0.12]; 21.5, s, [0.08]; 129.2, s, 7, [0.05]; 132.4, s, 6, [0.05]; 29,
s, [0.02]. After 17 days the same species are present in a different
ratio: 1:2:1.5:1:0.7:0.07:0.23:0.23:0.07, respectively.

70
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
Scheme 1. (a) Products observed during the chlorination reaction of 1 at r.t., in a sealed NMR tube, in CDCl3 with DBN. (b) Products observed
during oxidation and chlorination reaction of 1 at r.t. in an unsealed NMR tube, in CDCl3.
As described in Scheme 1, the chemistry of 1 in
CDCl3 consists basically of the chlorination and oxida-
tion of the PꢀH bond. The chlorination could take
place through the formation of a carbene from CDCl3
and the base DBN (Scheme 2), while the oxidation
could involve the activation of molecular oxygen by
free radicals. The oxidation may occur at the coordi-
nated PHPh2, which appears more reasonable com-
pared to other alternatives such as: (i) Initial
dissociation of PHPh2 from 1, giving a coordinatively
unsaturated species Cp*Ru(PHPh2)Cl followed by oxi-
dation of the free PHPh2 and coordination of the
resulting phosphine oxide to the ruthenium atom giving
a new OPꢀRu bond. This possibility was discarded
because compound 1 did not undergo any reaction in
the presence of an equivalent of OPHPh2 in refluxing
toluene for 4 h. A more polar solvent such as EtOH
was also used, but in that case, the product
Cp*Ru(POEtPh2)2Cl (11) was obtained as a result of
the ethanolysis of 1 after 24 h at r.t. (vide infra); (ii)
The participation of a coordinatively unsaturated com-
plex which might activate molecular oxygen, has been
reported during the oxidation of PPh3 catalyzed by
several organometallic compounds [7]. However, at-
tempts to add oxygen to 1 in toluene-d8 or in an even
more polar solvent were not successful. An isopropanol
solution of 1 even after 2 h in the presence of air at r.t.
did not give evidence of a OPHPh2 ligand.
the oxidation of 1 in chloroform, we considered
whether some of these species could be prepared di-
rectly from the interaction of dimer 12 with the
diphenylphosphine oxide (Scheme 3). From the latter
reaction, after 1 h in EtOH, compounds 7, 8 and
OPOEtPh2 were indeed obtained.
Considering the mechanism of the conversion of the
coordinated phosphine oxide to phosphinite (OPHR2)
ligands, it is well known that a tautomeric equilibrium
is present for phosphinites and their corresponding
Scheme 2. Proposed free radical mechanism for oxidation of the P–H
group in 1. (a) Carbenes in a triplet state abstract hydrogen or other
atoms; in the singlet state they only remove halogens [45]. (b) There
is evidence of CHDCl2 formation in the 1H-NMR spectrum.
2.2. Reaction of (Cp*RuCl2)2 (12) and OPHPh2
Due to the large number of products formed during

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
71
phosphinous acids (POHR2) [8]. Kinetic studies have
supported the fact that the slow step is the tautomeriza-
tion of the tricoordinated structure POHR2, which is
responsible for reactions with electrophiles. Addition-
ally, compound 12 can be regarded as an electrophile
which reacts with dienes, [9] |-donor ligands such as
phosphines, [10] and soft [11] or strong [12] nucle-
ophiles such as MeOH and Na[OP(OEt)2], respectively.
Then, we tentatively propose a nucleophilic attack by
the phosphorus lone pair of two POHPh2 ligands on
one of the ruthenium atoms in compound 12, giving
complex 7. The formation of compound 8 is attributed
to the presence of 7 and a weakly solvated fragment
[Cp*Ru(solvent)n]+, which has already been observed
by Chaudret [13]. The dimeric compound 8 has been
characterized based on its similarities to the known
[CpRu[m-(h6-C6H5)PPh2]CpRu(PPh3)Cl]Cl [14]. Finally,
the formation of OP(OEt)Ph2 can be expected to result
from a nucleophilic attack of EtOH on the phosphorus
atom of the diphenylphosphine oxide under the reflux-
ing conditions used.
will refer exclusively to the species observed or isolated
as by-products during the synthesis of 1.
2.3.1. Reaction of PHPh2 with Cp*Ru(PPh3)Cl2
The addition of three equivalents of PHPh2 to
Cp*Ru(PPh3)Cl2 gave a mixture of 1, 5, PHPh2 and
PPh3. Chromatography of this mixture on silica gel
afforded 1 in 48% yield, along with a dihydride com-
pound [Cp*Ru(H)2(OPPh2)(POHPh2)] (13) in 19% yield
and small amounts of compounds [Cp*Ru(PHPh2)3]Cl
(14) and [Cp*Ru(POHPh2)(PHPh2)2]Cl (15) (Scheme 4).
When chromatography was carried out on pure com-
pound 1, 1 was recovered in 67% yield along with 7% of
13, showing that hydrolysis of 5 is more facile than that
of 1. Compound 5 was also observed from the reaction
of 1 with chloroform (vide supra, 1a) and it has, as
1
already mentioned, only been characterized by H- and
31P-NMR spectroscopy as was also the case for 14 and
15.
The formation of 14 and 15 may be rationalized as
resulting from the easy dissociation of Cl− from 1 and
5, which, in the presence of an excess of PHPh2, would
lead to 14 and 15. In order to confirm this hypothesis
we prepared [Cp*Ru(PHPh2)3]OTf (14%) from 1 and
AgOTf in acetonitrile (Scheme 5).
2.3. By-products obtained during the synthesis of
compound Cp*Ru(PHPh2)2Cl (1)
We reported earlier the preparation of compound 1
in varying yields depending on the starting materials
used: Cp*RuLCl, L=COD (90%), L=1,5-NBD
(1.5%), [Cp*RuCl]4 (75%); Cp*Ru(PPh3)2Cl (67%);
[Cp*RuCl2]2 (60%); Cp*Ru(PPh3)Cl2 (48%) [6]. More
recently, we isolated 1 from the last (paramagnetic)
compound in 59% yield, as a result of changing the
mixture of solvents used in the chromatography (8:2
hexane–diethyl ether). In the following discussions, we
Precipitation of AgCl gave [Cp*Ru(MeCN)-
(PHPh2)2]OTf (16) cleanly. Addition of 1.2 equivalents
of PHPh2 to 16 then afforded 14% which showed the
1
same 31P- and H-NMR spectra as 14. An NMR exper-
iment showed that in solution compound 14% suffers
transformation into mono- and disubstituted com-
pounds [Cp*Ru(POHPh2)(PHPh2)2]OTf (15%) and
[Cp*Ru(POHPh2)2(PHPh2)]OTf
(17),
respectively.
These compounds were not isolated, but their charac-
Scheme 3.

72
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
Scheme 4.
terizations were straightforwardly carried out through
1H- and 31P-NMR spectroscopy.
to their characteristic NMR patterns. Binuclear 8 is
rather similar to [CpRu(m-h6-C6H5)PPh2]RuCp(PPh3)-
Cl]X [X=Cl, BPh4] [14]. In its 31P-NMR spectrum at
109.25 MHz, 8 in CDCl3 exhibits two signals: a doublet
(JPP=55.5 Hz) and a broad singlet while at 36.22 MHz
the broad signal is partially resolved as a broad doublet
(JPP=51.3 Hz)4. The same spectrum at −90°C showed
two well-defined doublets (JPP=55.5 Hz). Similarly, 8 in
CD2Cl2 at r.t. and at 109.25 MHz exhibited a weakly
resolved doublet (JPP=53 Hz). It is not clear whether
this behavior is due to a relaxation effect for P1
(ꢀPOHPh2) or an electronic effect.
2.3.2. Reaction of PHPh2 with (Cp*RuCl2)2 (12)
Two equivalents of PHPh2 in EtOH react with dimer
12 affording, according to 31P-NMR, a mixture of three
compounds: 1, Cp*Ru(POEtPh2)(PHPh2)Cl (18) and
Cp*Ru(POEtPh2)2Cl (11) in a 1:0.6:0.1 ratio (Scheme 3).
Chromatography on silica gel afforded two fractions:
The first one, eluted with hexane/diethyl ether (4:1),
contained the unseparated compounds 1, 11 and 18.
After several recrystallizations, the components of this
fraction could be separated, affording pure compounds
11 and 18. The second minor fraction was eluted with
acetone/hexane (1:1) and gave a mixture of products 13
and 19 [Cp*Ru(POHPh2)(POEtPh2)Cl] which arose
through hydrolysis of the corresponding compounds 1
and 18. The small amount of 19 isolated only allowed
The assignments of P1 (ꢀPOHPh2) and P2 (ꢀPOHPh)
were carried out through 31Pꢀ1H heteronuclear correla-
tion. Coupling between ortho-hydrogens of the coordi-
3
nated phenyl ring and P2 showed a JPH=6 Hz, while
hydrogens from POH functions were found by 1H-NMR
to be correlated with P2 (l=9.6, d, 5 Hz) and P1
(l=8.4, d, 4.5 Hz).
1
for its characterization through H- and 31P-NMR.
In order to determine if reaction of the PꢀH group in
PHPh2 occurs before or after the formation of com-
pound 1 we carried out two experiments: (i) PHPh2 was
mixed with EtOH, showing after 24 h at r.t. mostly
PHPh2 with only traces of OPHPh2. After 3 days, this
was heated at 60°C for 3 h without change. This result
suggested that PHPh2 did not suffer ethanolysis before
being coordinated to the ruthenium atom. (ii) Reaction
between 1 and EtOH, under a nitrogen atmosphere for
24 h at r.t., showed a complete transformation of 1 to
11 which indicates that the reaction of PHPh2 occurs
after formation of 1. However, it is important to
recognize that the ethanolysis is even faster when the
dimer 12 is used as the starting material.
When the chlorine counterion in 8 is replaced by PF6,
a drastic change was detected through 1H- and 31P-NMR
spectroscopy. An AB system with substantially different
chemical shifts (120.4 and 131.9 ppm) and coupling
constants (JPP=45.4 Hz) was evident from 31P-NMR.
Similar
behavior
has
been
reported
for
[(CH2)2S(O)MePt(PPh2Me)(POHPh2)]X (X=Cl, PF6)
[15], for which the 31P chemical shifts changed from 51.5
(X=Cl) to 67.9 ppm (X=PF6). This Dl=16.4 ppm was
attributed to an interaction between the Cl− and the
hydrogen of the POHPh2 ligand. For compound 8, a
similar Dl=15 ppm was observed and, according to
heteronuclear correlation (1Hꢀ31P) data, the hydrogen
bonding interaction of Cl is with the OH in P1.
1
2.4. H-, 13C- and 31P-NMR studies
2.4.1. Compounds
4 Interestingly, freshly prepared 1H-NMR tube samples afforded
broad signals, while after standing a couple of hours, sharper signals
were then observed. The same observation has been made by
Wilczewski [14a].
[Cp*Ru[v-(p6-C6H5)POHPh]Cp*Ru(POHPh2)Cl]Cl (8)
and [Cp*Ru(H)2(OPPh2)(POHPh2)] (13)
Compounds 8 and 13 deserve detailed discussion due

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
73
Scheme 5.
1
The H-NMR spectrum of 8 showed an asymmetric
with two different P-donor ligands showed JPP values
around 45–66 Hz, suggesting adjacent P atoms. It has
been predicted [20] that JPP should increase as the
phosphine p-accepting ability increases. This expected
trend was observed for compounds Cp*Ru(POHPh2)-
(POEtPh2)Cl (19)\Cp*Ru(PClPh2)(PHPh2)Cl (5)
\Cp*Ru(POEtPh2)(PHPh2)Cl (18), [CpRu(POHPh2)-
(PHPh2)2]Cl(20)\CpRu(PHPh2)(PPh3)Cl (4)\[CpRu-
(POHPh2)2(PHPh2)]Cl (21)\[Cp*Ru(POHPh2)2(PH-
Ph2)]OTf (17), [Cp*Ru(POHPh2)(PHPh2)2]Cl (15) as a
result of the presence of atoms more electronegative
than carbon in the phosphine ligands.
A comparison of JPP values and the P1ꢀRuꢀP2 bond
angles for compounds 3 [42.9 Hz, 91.33(8)°] and 4 [46.7
Hz, 92.26(8)°] suggests that the difference in JPP values
may be due to an electronic effect, since the bond
angles are very similar [6]. The same trend was found
for compounds 20 (47.9 Hz) and 21 (55.5 Hz).
aromatic ring with five triplets corresponding to the
benzene ring p-bonded to Ru5. A triplet was observed
for the methyl groups of one of the Cp* ligands due to
long range coupling (4JPH=1.8 Hz), while a singlet was
found for the Cp* bonded to the cationic ruthenium
atom. 13C-NMR spectra showed that the ortho and
meta carbon atoms were exclusively coupled to P2.
There was no evidence of coupling for Ci, even though
it has a direct bond to P2. The rest of the resonances
for the aromatic ring in the molecule were difficult to
assign, in contrast with mononuclear species 1, 6 and 7.
1
The dihydride complex 13 showed in its H-NMR
spectrum a triplet at −8.38 ppm (3JPH=25 Hz) for the
equivalent terminal hydride ligands, a triplet of triplets
at 1.29 ppm (4JPH=0.68 Hz) for the Cp* ligand, and a
singlet at 16.54 ppm (−90°C) for the hydroxy hydro-
gen atom, which above 0°C was observed as a broad
signal. The 31P-NMR spectrum showed a singlet at
116.37 ppm even at −90°C, suggesting a fast exchange
of the bridging hydroxy hydrogen between the two
phosphorus ligands in solution. The aromatic rings
present in the P ligands were also equivalent as shown
by 13C-NMR.
Resonances for the Cp ligand did not show evidence
3
1
of JPH couplings by H-NMR, while those for the Cp*
4
ligand appeared as triplets due to JPH. Similar long-
range couplings were reported for compounds
4
[Cp*M(PHPh2)2Cl]+ [M=Rh, l=1.45 (t), JPH=3.8;
4
M=Ir, l=1.49 (t), JPH=2.5] [21].
The methylenic hydrogen atoms of the OEt group in
compound 11 were observed as a multiplet which, after
irradiation of the Me group, afforded a triplet with
2.4.2. NMR tube experiment of compound 4 with
PHPh2
J
PH=2.5 Hz. This virtual coupling has also been de-
In the presence of 5 equivalents of PHPh2 in deuter-
ated toluene, compound 4 was found to lead to the
formation of 2. Following this reaction it was observed
that 2 was readily oxidized, giving several products,
including compounds [CpRu(POHPh2)(PHPh2)2]Cl
tected for aromatic i, o and m carbon atoms of the
phosphine ligands through 13C-NMR. Similar cou-
plings were observed for compounds Cp*Ru(PHPh2)2Cl
(1), CpRu(PHPh2)2Cl (2), Cp*Ru(PClPh2)2Cl (6),
Cp*Ru(POHPh2)2Cl (7), [Cp*Ru(MeCN)(PHPh2)2]OTf
(16) and [CpRu(POHPh2)(PHPh2)2]Cl (20), as well as
for compounds [(h3-C3H5)Pd(PPh3)2]+ and [(h3-
C3H5)Pd(PEt2Ph)2]+ [22].
The asymmetric compounds CpRu(PHPh2)(PPh3)Cl
(4) and Cp*Ru(POEtPh2)(PHPh2)Cl (18) showed three
and four chemically non-equivalent rings, respectively,
in the aromatic region, while disubstituted compounds
1, 2, 6, 7 and Cp*Ru(POEtPh2)2Cl (11) with prochiral
Ru and P atoms gave eight signals in the aromatic
region: six triplets and two singlets. This fact suggests
free rotation of the PꢀC aromatic ring bonds leading to
the corresponding equivalence of the respective ortho
and meta carbon atoms in both rings. Interestingly,
[Cp*RuPOHPh2(PHPh2)2]Cl (15) showed virtual cou-
(20),
[CpRu(POHPh2)2(PHPh2)]Cl
(21)
and
diphenylphosphonic acid, OPOHPh2.
A few examples of complexes with POHPh2 ligands
are known in the literature, namely, W(CO)4(POHPh2)-
(PPh2CH2COR) (R=Ph, p-MeC6H4) [18] and
PtCl2(PXR2) (X=OH, R=OEt,Ph, Et) [19].
2.4.3. General spectroscopic trends
The 31P-NMR spectra of Cp and Cp* complexes
5 It is interesting to contrast the good resolution obtained for
compound 8 with the poorer results for compounds [CpRu(m-h6-
C6H5)PPh2]RuCp(PPh3)Cl]X
[X=Cl, BPh4]
[14]
CpRu(h6-
C6H5PPh2)BPh4 [14], CpRu(h6-C6H5)BPh3 [16]; [CpRu(h6-C6H5-
POPh2]X (X=Cl, BPh4 14a; X=ClO4 [17]).

74
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
pling for the aromatic carbon atoms of the two PHPh2
ligands, while for POHPh2 only doublets were ob-
served, indicating that the coupling only involves one of
the P atoms.
for similar Cp complexes [25,26] and penta-
dienyl derivatives [27], including complexes (h5-
CnHm)Ru(PHPh2)(PPh3)Cl [n=5, m=7, 91.73(3),
96.70(3), 93.34(3); n=7, m=11, 85.81(2), 85.92(2),
92.45(2)°] [28] allowed us to compare the influence of
the phosphine ligands in these ‘half sandwich’ com-
pounds. Notably, Cp complexes with two different
P-donor ligands [25,26] showed no significant difference
between their ClꢀRuꢀP1 and ClꢀRuꢀP2 angles, while
the disubstituted Cp* species 1 [D=6.5°] [6] and 6
[D=3.5°], as well as pentadienyl complexes (h5-
C5H7)Ru(PEt2R)2Cl [R=Et D=6.76°; R=Ph D=
4.74°] [27] showed important differences between these
angles, reflecting the higher steric congestion of the Cp*
and the open pentadienyl ligand compared to the
analogous Cp species. The same trend has been ob-
served for the mixed Cp species 4 (D=0.84°) [6] and
Cp* species 3 (D=8.9°) [6] and 18 (D=6.2°).
2.5. Crystal structures of compounds Cp*Ru(PClPh2)2-
Cl (6), [Cp*Ru(H)2(OPPh2)(POHPh2)] (13), Cp*Ru-
(POEtPh2)(PHPh2)Cl (18) and [CpRu(POHPh2)(PH-
Ph2)2]Cl (20)
Selected crystallographic data are summarized in
Table 1, and ORTEP diagrams of 20, 18, and 13 are
displayed in Figs. 1, 2 and 4, respectively. Crystals of
compound 6 showed the presence of a disordered
molecule of hexane; the refinement was carried out
exclusively for the metallic fragment, which is shown in
Fig. 3.
2.5.1. Molecular structure of [CpRu(POHPh2)(PH-
Ph2)2]Cl (20)
As expected from the ligand cone angles, compound
6 (137°) [29] was found to have its three PꢀRuꢀ(P,Cl)
The molecular structure of cationic complex 20 has a
three-legged piano stool geometry with angles near 90°
between the phosphine ligands, indicating a pseudo-oc-
tahedral ruthenium atom in which the steric interac-
tions for PHPh2 and POHPh2 ligands are very similar.
The structure of compound 20 showed disorder as a
result of the POHPh2 ligand being present in all three
phosphine locations, yielding occupancy values for the
oxygen sites of 0.1586 (O1), 0.1566 (O2) and 0.6853
(O3). Thus, P3 has the highest POHPh2 character and
the RuꢀP3 bond length is similar to the value of
angles greater than 90°, and a RuꢀCp*
distance
centroid
longer than that found for 1 or the mixed compounds
3, 4 and 18, as a result of the electronegative Cl atom in
the phosphine ligands. Thus, a greater angular separa-
tion was required for the PClPh2 ligands in 6. The mean
,
RuꢀP2 distance (2.278 A) in compounds 1, 3, 4 and 18
is shorter than the corresponding ones for trans-
Ru(PHPh2)4Cl2 (D=2.358 A) [4,30], or (h5-
,
,
CnHm)Ru(PHPh2)(PPh3)Cl (n=5, m=7, 2.308 A;
,
n=7, m=11, 2.297 A) [28].
Interestingly, the RuꢀP1 and RuꢀP2 distances in 6
are shorter than the RuꢀPHPh2 distances in 1, 3, and 4
even though the cone angle for PClPh2 (137°) is larger
than the corresponding one for PHPh2 (128°). This may
reflect a predominantly electronic effect, the general
shortening observed for p-accepting ligands [31]. The
parallel orientation observed for the two aromatic rings
in 6 (Fig. 3) likely represents a favorable p–p stacking
interaction between the two rings. Some of the resulting
,
2.274(1)A in 13. Selected bond distances and angles are
reported in Table 2.
The RuꢀC (Cp) distance showed small deviations by
the Cp plane from perpendicularity relative to the
,
RuꢀCcentroid vector (1.890 A). The latter distance is
significantly longer than other RuꢀCcentroid distances,
,
,
such as those in 4 (1.841 A) [6], 18 (1.868 A), and other
Cp [23] and Cp* [6,24] complexes, except for 6 (1.884
,
,
A) and 13 (1.914 A). This observation may reflect the
smaller electron density on the Ru atom due to the
presence of the better p acceptor POHPh2 ligand.
,
non-bonded contacts are: Cl(10)ꢀCl(20) (3.784 A),
,
,
C29ꢀC17 (3.421 A), C30ꢀC18 (3.590 A), C31ꢀC19
,
,
,
(3.748 A), C32ꢀC20(3.746 A), C33ꢀC21 (3.554 A) and
C34ꢀC22 (3.380 A), which would thus require the par-
,
2.5.2. Molecular structures of Cp*Ru(PClPh2)2Cl (6)
and Cp*Ru(POEtPh2)(PHPh2)Cl (18)
allel positioning of the aromatic rings.
A shorter RuꢀCl distance was observed for 6 com-
pared to 1, presumably due to the lower electron den-
sity on the ruthenium atom. The C11ꢀP1ꢀC17 (97.5°)
and C29ꢀP2ꢀC35 (99.1°) angles in 6 are significantly
smaller than those of 101.5° and 104.9° for 1, reflecting
the greater steric crowding experienced on coordination
by PClPh2 as compared to PHPh2. The same trend
holds for POEtPh2 and PHPh2 in 18.
Selected bond distances and bond angles are given in
Table 3 for neutral pseudo-octahedral structures 6 and
18.
From the Cl(1)ꢀRuꢀP1, Cl(1)ꢀRuꢀP2 and P1ꢀRuꢀP2
bond angles for several of the three-legged piano
stool structures, it is clear that the increase in the
octahedral distortion follows the order: CpRu-
(PHPh2)(PPh3)Cl(4)BCp*Ru(PHPh2)2Cl (1):Cp*Ru-
(POEtPh2)(PHPh2)Cl (18)BCp*Ru(PHPh2)(PPh3)Cl-
(3)BCp*Ru(PClPh2)2Cl (6). The corresponding
Cl(1)ꢀRuꢀP1, Cl(1)ꢀRuꢀP2 and P1ꢀRuꢀP2 angles
In summary, we can conclude that PClPh2 ligands in
compound 6 are better p acceptor than PHPh2 and
PPh3 in their analogous complexes (1, 3 and 4) [6]; this

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
75
Table 1
Crystal data for 6, 13, 18 and 20
Formula
C
34H35P2 Cl3Ru (6) a
C34H38O2P2Ru·CHCl3 (13) C36H41OP2ClRu (18) [C41H38OP3Ru]Cl (20)
Molecular weight
Crystal system
713.03 a
P21/c
16.717(5)
9.789(2)
23.724(7)
90.0
761.08
P1
688.20
P1
775.5
Pbca
12.150(4)
17.712(2)
33.241(5)
90
90
90
7154(3)
8
3168
Mo–Ka (u=0.7107 A)
6.68
1.44
ꢀ/2q
0.8+0.345 tg q
1–25
5918
˚
a (A)
10.156(4)
10.869(4)
16.718(7)
106.44(3)
89.89(3)
104.25(3)
1711.05
2
10.537(3)
16.367(5)
10.954(4)
80.20(2)
113.47(2)
108.16(2)
1644.12
2
˚
b (A)
˚
c (A)
h (°)
i (°)
k (°)
107.59(3)
90.0
3
˚
V (A )
3700.9(1.7)
4
Z
F(000)
1820 a
780
712
˚
˚
˚
˚
Radiation
Mo–Ka (u=0.7107 A) Mo (l=0.7107 A)
Mo (l=0.7107 A)
6.71
1.39
ꢀ/2q
0.8+0.34 tg q
2–25
6108
v (Mo–Ka) (cm−1
)
9.23
8.07
1.477
ꢀ/2q
0.8+0.35 tg q
1–25
Dcalc (g cm−3
Scan type
Dw (°)
)
1.6 a
ꢀ/2q
0.80+0.345 tg q
1–25
q limit (°)
Total data
7156
6234
Total unique data
6506
3900
0.04
6004
4555
B1
5420
4077
B1
5354
2156
B1
Total observed data (Fo)2\3|(Fo)2
Decay %
DIFABS corr. range
0.37:1.45
0.088
0.099
0.93:1.045
0.0374
0.0492
400
0.68:1.0
0.0507
0.0605
374
0.93:1.1
0.039
0.041 ꢀ=1.0
434
b
Final R1
Final wR2
c
No. of refined parameters
390
a There are some electron density peaks that suggest a disordered solvent molecule in the lattice. The refinement reported here was obtained
excluding the solvent molecule.
b R1=ꢀ(ꢁFoꢁ−ꢁFcꢁ)/ꢀꢁFoꢁ.
c wR2=[ꢀw(ꢁFoꢁ−ꢁFcꢁ)2/ꢀwF2o]1/2
.
is reflected by the increase in the MꢀCpcentroid distance,
perhaps the smaller CꢀPꢀC angles and a shortening of
the RuꢀP bond. However, it is also true that there is not
a general increase in the PꢀC distances, which perhaps
reflects only a weak participation of their s* bonds in
backbonding interactions [31].
ties, and also the increased steric repulsions in 13.
Various electron deficient species, such as the dimers
(Cp*RuCl2)2 (12) (2.191 A), [(h5-C5Me4Et)RuCl2]2
,
,
,
(2.191 A) and [Cp*RuBr2]2 (2.194 A) showed longer
Cp*centroidꢀRu distances [40] compared to 13.
The P1ꢀRuꢀP2 angle (95.40°) is somewhat similar to
that of [Cp*FeH2(dippe)]BF4 [37] but even closer to those
found for other dihydride compounds without chelating
phosphines [32,33,35,36,38,39]. The RuꢀP2 distance of
2.5.3. Molecular structure of [Cp*RuH2(OPPh2)(POH-
Ph2)]·CHCl3 (13)
The complex has a four-legged piano stool geometry
(Fig. 4), with the ruthenium atom then formally hepta-
coordinated. There is also a molecule of chloroform in
the unit cell. Selected bond lengths and angles are
reported in Table 4.
The angle of 85.58° between the Cp* and P1ꢀRuꢀP2
planes represents the greatest deviation from perpendic-
ularity among similar MH2L2 complexes [32–39]. The
,
,
2.274 (1) A is shorter than that for RuꢀP1, 2.291(1) A,
reflecting the better ability of P2 to receive electron
density from the metal. To the best of our knowledge,
no examples of crystalline rutheniumꢀhydrogen phos-
phonate complexes exist. A report on the platinum
complex cis-PtH[OPPh2][POHPh2](PEt3), prepared by
the addition of OPHPh2 to Pt(PEt3)3, [41] showed quite
,
similar MꢀP bonding. The O1ꢀO2 separation (2.317 A)
is shorter than the corresponding value for 13 (2.467(4)
,
Cpc*entroidꢀRu distance (1.914 A) in 13 is similar to that
,
A). However, both distances are shorter than the sum of
found for some of the dihydride complexes described
above [32–35], but significantly longer than those for the
pseudo-octahedral Ru(II) compounds Cp*Ru(NBD)Cl,
(1, 3, 4) [6], 18 and 20. This increase may reflect reduced
electron density on the ruthenium(IV) center, due to both
its greater charge as well as the presence of oxygenated
phosphorus ligands which have good p acceptor proper-
the van der Waals radii, which is indicative of hydrogen
bonding involving the two oxygen atoms. Further sup-
port for this conclusion is provided by the observation
that the two PꢀO bond lengths (P1ꢀO1, P2ꢀO2) have
,
values between those reported for single (1.60 A) and
,
double [1.483(2) A] PꢀO bonds [41]. However, the

76
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
Fig. 1. ORTEP drawing of compound [CpRu(POHPh2)(PHPh2)2]Cl (20).
OꢀH1C distances are not equivalent. Thus, it could
be proposed that H1C is covalently bonded to O2
and hydrogen bonded to O1 (Table 4).
Organic Chemicals), silica gel (Merck, 0.04–0.063
mm) were used as supplied. The (Cp*RuCl2)2 (12)
[40], (1–4) [6], and OPHPh2 [42] reagents were syn-
thesized using literature procedures.
3. Experimental
3.1. Synthesis of Cp*Ru(PClPh2)2Cl (6)
All compounds were prepared under a dry nitrogen
atmosphere using conventional vacuum line tech-
niques. Solvents were dried and distilled prior to use
by standard methods. Elemental analyses were per-
formed by Oneida Research Services Inc., Whites-
boro, NY and Robertson Microlit Laboratories, Inc.,
Madison, NJ. Melting points (uncorrected) were ob-
tained on a Mel-Temp apparatus in sealed capillaries.
IR spectra (4000–200 cm−1) were recorded on a
Perkin–Elmer 16FPC-FT spectrophotometer. Elec-
Compound 1 (425 mg, 0.66 mmol) was dissolved in
CHCl3 (15 mL) under nitrogen, and Et3N (0.12 mL,
0.86 mmol) was added at ambient temperature. The
solution was refluxed for 8 h, without any obvious
color change. The CHCl3 was removed under vacuum
and hexane extractions afforded an orange–red pow-
der which was recrystallized with CHCl3/hexane.
Yield 83.7 mg (17.8%); m.p. 122–125°C. Anal. Calc.
for C34H35Cl3P2Ru·CHCl3: C, 50.50; H, 4.36 Found:
C,50.37; H,4.13. 1H-NMR (CDCl3): l 7.90–6.90 (m,
20H), 1.34 (t, 4JPH=2.64, 15H); 31P{1H}-NMR: l
132.32 (s); 13C{1H}-NMR: l 141.07 (t, 16.5, i ),
140.41 (t, 15.4, i ), 132.53 (t, 7.7, o), 131.13 (t, 6.6,
o), 129.88 (s, p), 129.15 (s, p), 127.37 (t, 5.5, m),
127.29 (t, 5.5, m), 95.65 (s, Cp*), 9.14 (s, Cp*). Mass
spectrum (EI+VE, 25 eV): m/z (%); 714(10) [M+
1]+, 729(7), 658(4), 678(2), 544(18), 492(70.5), 472(9),
457(40), 421(8.5), 272(1.7), 236(1.5), 220(100),
183(50.6), 154(77.7), 107(20.0).
tron-impact mass spectra were recorded on
a
Hewlett–Packard HP-5990A or a Finnigan MAT95
(FAB) mass spectrometer. 1H-, 31P- and 13C-NMR
spectra were recorded at 270, 109.25 and 67.8 MHz
on a Jeol GSX-270 spectrometer or at 90, 36.2 and
22.5 MHz on a Jeol FX90Q spectrometer. Spectral
standards were TMS (1H, 13C) and 85% H3PO4 (31P).
Purchased reagents, RuCl3·3H2O, PHPh2, C5Me5H,
Zn (Strem), PPh3, AgOTf, n-BuLi (Aldrich), C5H6
(previously cracked from dicyclopentadiene, Eastman

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
77
Fig. 2. ORTEP drawing of compound Cp*Ru(POEtPh2)(PHPh2)Cl (18).
3.2. Synthesis of Cp*Ru(POHPh2)2Cl (7) and [Cp*Ru-
[v-(p6-C6H5)POHPh]Cp*Ru(POHPh2)Cl]Cl (8)
gel [7:3 hexane–diethyl ether elution] afforded an or-
ange–yellow powder, which after recrystallization gave
250 mg of 7 (20%). m.p. (dec) 110°C. Anal. Calc. for
C34H37ClO2P2Ru: C, 60.40; H, 5.52. Found: C, 60.88;
Compound 12 (568 mg, 1.85 mmol) was dissolved in
EtOH (20 mL), and OPHPh2 (746 mg, 3.69 mmol) was
added to the stirred dark-brown solution at r.t. After 1
h of reflux the wine-red solution was filtered and con-
centrated to half of its original volume. Compound 8
precipitated as a yellow powder upon overnight cooling
to 0°C and it was filtered and recrystallized twice; first,
from CH2Cl2/hexane and then from CHCl3/hexane.
Yield 230 mg (13.1%); m.p. 140–142°C. Anal. Calc. for
C44H52Cl2O2P2Ru2·CH2Cl2: C, 52.33; H,5.23; Cl, 13.73
Found: C, 51.51; H, 4.95; Cl, 12.25. 1H-NMR
(CD2Cl2): l 9.6 (d, 5, 1H), 8.4 (d, 4.5, 1H), 8.3 (s, br,
1H), 7.77 (s, br, 1H), 7.65 (t, 8.6, 1H), 7.3–7.5 (m, 2H),
7.0–7.15 (m, 5H), 6.8–6.97 (m, 5H), 6.27 (t, 6, 1H, o),
5.86 (t, 6, 1H, o%), 5.06 (t, 6, 1H, m%), 4.62 (t, 6, 1H, p),
4.52 (t, 6, 1H, m), 1.48 (s, 15H, Cp*), 1.03 (t, 1.8, 15H,
Cp*); 31P{1H}-NMR (CDCl3): l 117.36 (d, 55.5),
106.15 (br). 13C{1H}-NMR (CDCl3): l 148.51 (d, 28.7,
i ), 140.58 (d, 49.5, i ), 126.5–128.2 (m), 129.5–132.5
(m), 109.43 (s), 95.31 (s, Cp*), 92.99 (s, Cp*), 86.89 (d,
11), 85.95 (d, 13.2), 85.58 (s), 84.37 (d, 5.6), 82.90 (d,
4.4), 10.67 (s, Cp*), 9.26 (s, Cp*). IR: w(OH)=3442,
w(PꢀOH)=870. Mass spectrum (20 eV, EI): m/z(%)
912(4.0) [M+], 1082(4.56), 926(14.35), 880(9.20),
844(37.9), 833(100.0), 818(83.36), 632(31.36), 544(64.0),
472(9.9), 437(2.0), 361(13.2), 371(25.1), 315(5.0),
78(40.7), 52(3.0). [LR/FAB (3NBA/CHCl3)]: 912(2.6)
[M+], 877(0.5), 709(0.6), 439(7.3), 154(100), 136(68)].
After filtration of 8 the remaining ethanolic solution
was reduced in volume, and chromatography on silica
1
H, 5.53. H-NMR (CDCl3): l 7.15–7.43 (m, 20H), 4.90
(s, br, 2H), 1.29 (t, 1.8, 15H); 31P{1H}-NMR: l 129.23
(s); 13C{1H}-NMR: l 142.45 (dd, 23, i ), 140.23 (dd, 27
i ), 130.66 (dd, 6.5, o), (two overlapped triplets), 129.48
(s, p), 129.16 (s, p), 127.57 (dd, 5.5, m), 127.31 (dd, 4.4,
m), 91.98 (s, Cp*), 9.66(s, Cp*). IR: w(OꢀH)=3343,
w(PꢀOH)=828. Mass spectrum [LR/FAB (3NBA/
CHCl3)]: m/z (%) 676(6.94) [M+], 641(19.3),
474(10.51), 439(68.2), 422(7.36), 361(13.11), 314(16.32),
236(7.59), 91(52.4), 55(100.0).
3.3. Synthesis of Cp*RuH2(OPPh2)[POHPh2] (13),
[Cp*Ru(PHPh2)3]Cl (14) and [Cp*Ru(POHPh2)-
(PHPh2)2]Cl (15)
Compound Cp*Ru(PPh3)Cl2 (1.32 g, 2.32 mmol) was
partially dissolved in THF (70 mL), and PHPh2 (1.21
mL, 6.96 mmol) was added dropwise with stirring at r.t.
The solution was refluxed for 4 h, giving a yellow–or-
ange solution, which was filtered and reduced in vacuo
(31P-NMR of the crude product showed a mixture of
species 1, 5, PHPh2 and PPh3). The residue was dis-
solved in a small amount of toluene and chromatogra-
phy was carried out with a silica gel column (4.5×15.5
cm) using hexane, 7:3 hexane–diethyl ether and 1:1
hexane–acetone, giving PHPh2 and PPh3, 1 (715 mg,
48%), and 13 (295 mg, 20%), respectively. Crystals of 13
for X-ray studies were obtained by liquid diffusion of
hexane into a CHCl3 solution. m.p. (dec.) 175°C. Anal.

78
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
Fig. 3. ORTEP drawing of compound [Cp*Ru(PClPh2)2Cl (6).
3.4. Synthesis of [Cp*Ru(PHPh2)2(MeCN)]OTf (16)
Calc. for C34H38O2P2Ru: C, 63.65; H, 5.97 Found: C,
63.80; H, 5.54. 1H-NMR (CD2Cl2): l 16.54 (s, 1H,
−90°C), 7.29–7.56 (m, 20H), 1.29 (tt, 0.67, 15H), −8.38
(t, 25, 2H); 31P{1H}-NMR (CD2Cl2): l 116.37 (s);
13C{1H}-NMR (CDCl3): l 143.52 (t, 65, 2.2, i ), 131.54
(t, 5.5 and two lateral signals of 27.6 Hz, o), 129.45 (s,
p), 127.50 (t, 5.5 and two lateral signals of 26.4 Hz, m),
98.02 (s, Cp*), 9.10 (s, Cp*). IR w(OH)=3564,
w(RuꢀH)=1994, w(P=O)=1098, w(PꢀOH)=980 (in
accord with Ref. [12]). Mass spectrum [LR/FAB (3NBA/
benzene)]: m/z (%) 641(12.3) [M+], 439(14.3), 361(4.3),
313(2), 154(100), 136(72.4), 107(21.8), 55(32.2). Final
elution of the chromatographic column with an ethanol
solution gave a mixture of compounds 14 and 15 in a 1:20
ratio according to a 31P-NMR spectrum. Compound 14
1H–NMR (CDCl3): l 7.5–6.8 (m, Ar), 5.83 (s, PH) 1.57
(q, 4JPH=1.67, 15H); 31P-NMR: l 35.74 (d, JPH=370).
To a 10 mL solution of MeCN containing 1 (80 mg,
0.124 mmol) was added 1 equivalent of AgOTf (32 mg,
0.124 mmol) with stirring at r.t. A white–gray precipitate
of AgCl began to form immediately. The solution was
stirred for 30 min and filtered giving a light yellow
solution, which was evacuated to dryness. The oily
residue was dried in vacuum, but several attempts to
crystallize the oil failed. After treatment with CH2Cl2–
hexane and MeCN–diethyl ether an oil remained. 31P-
NMR showed, however, that the sample of 16 was pure.
1H-NMR (CD2Cl2): l 7.40–6.90 (m, 20H), 5.68 (s, 1H,
4
PH), 2.06 (t, 1.7, 3H), 1.42 (t, JPH=2.5, 15H); 31P-
NMR: l 33.92 (d, JPH=358.1). 13C{1H}-NMR: l 138.86
Table 2
1
Compound 15 H-NMR (CDCl3): l 11.10 (s, br, 1H),
Selected bond distances and angles for 20
3
7.65–6.87 (m, 30H), 5.87 (d, PH, JPH=7.9), 1.45 (q,
˚
4JPH=1.87, 15H); 31P-NMR: l 37.39 (d, 42.8, JPH=357,
PHPh2), 127.71 (t, 42.8, POHPh2); 13C{1H}-NMR: l
140.38 (d, 44.1, i ), 133.02 (t, 5.5, o), 132.94 (t, 5.5, o),
132.34 (d, 12.1, o), 129.89 (s, p), 129.64 (s, p), 129.38 (s,
p), 128.36 (t, 5.5, m), 127.60 (d, 9.9, m), 95.72 (s, Cp*),
10.07 (s, Cp*). Mass spectrum [LR/FAB (3NBA/
CHCl3)]: m/z(%) 811(2.0) [M+], 625(16.0), 609(5.0),
439(26.0), 423(26.2), 361(3.62), 313(3.81), 91(36.67),
73(100), 55(75.7), 43(63.4).
Bond distances (A)
Bond angles (°)
RuCp* a
Ru1ꢀP1
Ru1ꢀP2
Ru1ꢀP3
P1ꢀO1
1.890
P1ꢀRu1ꢀP2
P1ꢀRu1ꢀP3
P2ꢀRu1ꢀP3
Ru1ꢀP1ꢀO1
Ru1ꢀP2ꢀO2
Ru1ꢀP3ꢀO3
90.64(9)
88.80(1)
89.20(1)
115.7(13)
117.5(13)
119.7(3)
2.295(3)
2.268(3)
2.282(3)
1.59(3)
1.56(4)
1.607(8)
P2ꢀO2
P3ꢀO3
a Cp* denotes the centroid of the ring.

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
79
Table 3
Selected bond distances and angles for 6 and 18
,
Bond distances (A)
Bond angles (°)
6
18
6
18
Ru1ꢀCl(1)
Ru1ꢀP1
Ru1ꢀP2
P1ꢀC11
P1ꢀC17
P2ꢀC29
P2ꢀC35
P2ꢀH2
2.439(3)
2.255(3)
2.239(3)
1.83(1)
1.83(1)
1.85(1)
1.82(1)
–
2.086(4)
2.089(4)
–
–
–
2.450(2)
2.273(2)
2.273(3)
1.831(6)
1.849(7)
1.840(6)
1.816(6)
1.387(56)
–
Cl(1)ꢀRu1ꢀP1
Cl(1)ꢀRu1ꢀP2
P1ꢀRu1ꢀP2
95.8(1)
92.3(1)
93.5(1)
115.8(4)
127.7(4)
97.5(5)
124.8(4)
116.9(4)
99.1(5)
111.7(2)
100.8(4)
99.2(4)
112.3(2)
99.2(4)
100.5(4)
–
90.38(6)
84.21(6)
91.40(6)
119.3(2)
116.1(2)
100.4(3)
116.3(2)
122.0(2)
103.6(3)
–
Ru1ꢀP1ꢀC11
Ru1ꢀP1ꢀC17
C11ꢀP1ꢀC17
Ru1ꢀP2ꢀC29
Ru1ꢀP2ꢀC35
C29ꢀP2ꢀC35
Ru1ꢀP1ꢀCl(10)
Cl(10)ꢀP1ꢀC11
Cl(10)ꢀP1ꢀC17
Ru1ꢀP2ꢀCl(20)
Cl(20)ꢀP2ꢀC29
Cl(20)ꢀP2ꢀC35
Ru1ꢀP1ꢀO
P1ꢀCl(10)
P2ꢀCl(20)
P1ꢀO
–
1.637(5)
1.403(9)
1.50(1)
1.868
–
–
–
–
OꢀC41
C41ꢀC42
RuꢀCp* a
1.884
–
110.1(2)
103.9(3)
105.5(3)
128.8(5)
OꢀP1ꢀC11
OꢀP1ꢀC17
P1ꢀOꢀC41
–
–
–
a Cp* denotes the centroid of the ring.
(t, 4.4, o), 132.39 (t, 4.4, o), 132.12 (t, 21.0, i ), 130.97
(t, 22.6, i ), 130.69 (s, p), 130.44 (s, p), 129.26 (t, 4.4, m),
129.09 (t, 4.4, m), 126.68 (s, OTfꢀ), 92.04 (s, Cp*), 9.36
(s, Cp*), 4.32(s, Me). Thesignalforthequaternarycarbon
of MeCN was not observed.
(d, 8.8, Me), 9.71 (s, Cp*). Mass spectrum [LR/FAB
(3NBA/CHCl3)]: m/z(%); 688(30.69) [M+], 653(72.78),
502(35.20), 467(29.95), 457(7.82), 437(5.63), 422(25.9),
314, 231(7.16), 154(100), 136(69.62). Compound 11 was
subsequently isolated from the mother liquor after several
recrystallizations with hexane at −5°C. Yield: 10 mg
1
(18%) m.p. 154–160°C. H-NMR (CDCl3): l 7.00–7.55
3.5. Synthesis of Cp*Ru(POEtPh2)2Cl (11) Cp*Ru(PO-
EtPh2)(PHPh2)Cl (18), and Cp*Ru(POHPh2)(POEtPh2)
(19)
4
(m, 20H), 3.38–3.50 (m, CH2, 4H), 1.30 (t, JPH=1.5,
15H), 1.01 (t, 7.0, Me, 6H); 31P{1H}-NMR: l 139.19 (s);
13C{1H}-NMR: l 132.54 (t, 5.5, o), 132.33 (t, 5.5, o),
128.85 (s, p), 128.04 (s, p), 127.05 (t, 4.4, m), 126.92 (t,
4.4, m), 91.92 (s, Cp*), 62.37 (t, 5.5, OCH2), 16.26 (t, 3.3,
Me), 9.32 (s, Cp*). Mass spectrum [LR/FAB (3NBA/
CHCl3)]: m/z(%) 732(1.55) [M+], 697(58.68), 467(23.28),
422(4.6), 154(100), 136(64.43).
Compound 12 (300 mg, 0.96 mmol) was dissolved in
dry ethanol (15 mL), and PHPh2 (0.34 mL, 1.92 mmol)
was added dropwise with stirring at r.t. The solution
changed from dark-brown to yellowish-green. After the
solution had stirred for 1 h the 31P-NMR spectrum of the
crude product showed a mixture of species 1, 11, and 18
in a 1:0.05:0.35 ratio, respectively, and no evidence of free
PHPh2. The solution was then filtered and evaporated to
dryness. The yellow powder was re-dissolved in CHCl3
and filtered again, leading to its separation from a black
residue. Successive recrystallizations with CH2Cl2–hex-
ane afforded the crystalline compound 18 in very low
Attempts to separate compounds 1, 11 and 18 by
column chromatography on elution with 4:1 hexane–di-
ethyl ether were not successful. However, when a 1:1
hexane–acetone mixture was used, a mixture of hydrol-
ysis products 13 and 19 was obtained. The compound
Cp*RuCl(POHPh2)(POEtPh2) (19) was characterized by
1
NMR from the reaction mixture. H-NMR (CDCl3): l
7.12–7.80 (m), 6.05 (s, br, OH), 3.40–3.50 (m, CH2), 1.29
1
yield, m.p. 165–175°C. H-NMR (CDCl3): l 7.00–7.62
4
(t, JPH=1.97, Cp*), 1.15 (t, 7.0, Me); 31P{1H}-NMR:
(m, 20H), 6.31 (d, JPH=362.2), 3.62–3.76 (m, 1H, CH2),
3.36–3.51 (m, 1H, CH2), 1.42 (t, 4JPH=2, 15H), 1.19 (t,
7.0, Me); 31P-NMR: l 137.67 (d, 47.9, POEtPh2), 35.49
(d, 47.9, PHPh2, JPH=363); 13C{1H}-NMR: l 138.33 (d,
40.8, i ), 137.87 (d, 34.1, i ), 135.06 (d, 36.3, i ), 134.97 (d,
35.2, i ), 134.54 (d, 9.9, o), 133.44 (d, 12.2, o), 132.60 (d,
8.8, o), 131.28 (d, 11, o), 129.36 (s, p), 128.59 (s, p), 127.82
(d, 8.9, m), 127.32 (d, 8.8, m), 127.09 (d, 9.9, m), 126.94
(d, 8.8, m), 90.38 (s, Cp*), 62.15 (d, 7.7, OCH2), 16.29
l 146.2 (d, 65.6), 135.0 (d,65.6).
3.6. NMR tube reactions6
(a) Compound 1 (30 mg, 0.047 mmol) was dissolved
in CDCl3 (0.5 mL), in the presence of 1.5 equivalents of
6 Only Cp or Cp* hydrogens are assigned because most of the
samples discussed in this section were not isolated.

80
R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
Fig. 4. ORTEP drawing of compound [Cp*Ru(H)2(OPPh2)(POHPh2)] (13).
DBN (8.68 mg, 8.64 mL, 0.07 mmol) and the NMR
tube was sealed under vacuum. After 20 min at r.t. the
formation of 5 [1H-NMR: l 1.45 (t, 1.98, Cp*), 5.99 (d,
368, PHPh2); 31P-NMR: l 34.7 (d, 50, JPH=368), 130.4
(d, 50)] was observed, yielding a 1:1 mixture with 1,
while after 220 min the ratio changed to 17:1. Longer
reaction times afforded compound 6 preferentially.
(b) Compound 3 (30 mg, 0.042 mmol) was dissolved
in CDCl3 (0.5 mL) at r.t. in a non-sealed NMR tube.
Subsequently a complex mixture of products was ob-
served from which compounds 1, 5, 9 [31P{1H}-NMR:
l 36.3 (d, 53), 130.2 (d, 53)] and 10 [1H-NMR: l −6.99
(t, 22.8, RuꢀH), 1.42 (s, Cp*); 31P{1H}-NMR: l 89.4
(s)] were observed in ratios of (1:0.7:0.5:0.12),
(1:1.5:1:0.7) and (0:0.4:0.12:0.03) after 10, 17 and 30
days, respectively.
(c) Compound 4 (30 mg, 0.046 mmol) was dissolved
in deuterated toluene (0.5 mL) and five equivalents of
PHPh2 (43 mg, 40 mL, 0.231 mmol) were added. The
reaction mixture was heated in an NMR tube for 67 h
at 100°C. After cooling the NMR tube sample at r.t.,
pale yellow crystals of 20 precipitated. The crystals
were filtered, giving: 1H-NMR (CDCl3): l 6.95–7.40
(m, 30H, Ar), 6.10 (s, 1H, OH), 5.01 (s, 5H, Cp);
31P-NMR: l 33.57 (d, 47.9, JPH=395.5, PHPh2) 125.0
(t, 47.9, POHPh2). After 8 days the NMR tube at r.t.
contained a crystalline mixture of 21 and diphenylphos-
phonic acid, OPOHPH2 in a 1:1 ratio. The precipitated
mixture was filtered and the isolated solid 21 showed:
[1H-NMR (CDCl3): l 7.0–7.8 (m, 30H, Ar), 6.38 (t,
6.11, 1H, PHPh2), 4.95 (s, 5H, Cp). 31P{1H}-NMR: l
37.8 (t, 45.4), 126.63 (d, 45.4)]. HOP(O)Ph2 [31P{1H}-
NMR (CDCl3): l 33.67 ppm].
(d) Compound 16 (30 mg, 0.047 mmol) was dissolved
in CDCl3 (0.5 mL) in the presence of 1.2 equivalents of
PHPh2 (10.4 mg, 9.7 mL, 0.056 mmol) giving 14% [1H-
NMR: l 5.83 (s, PHPh2), 1.55 (q, 1.67, Cp*); 31P-
NMR: l 36.0 (d, JPH=368)]. 14% oxidizes in the
Table 4
Selected bond distances and angles for 13
˚
Bond distances (A)
Bond angles (°)
RuꢀCp* a
RuꢀH1A
RuꢀH1B
RuꢀP1
RuꢀP2
P1ꢀO1
1.914(5)
1.34(4)
1.47(4)
H1AꢀRuꢀHIB
P1ꢀRuꢀP2
126.0(3)
95.40(4)
166.0(5)
72.0(2)
72.0(2)
71.0(2)
O1ꢀH1CꢀO2
P1ꢀRuꢀH1A
P1ꢀRuꢀH1B
P2ꢀRuꢀH1A
P2ꢀRuꢀH1B
RuꢀP1ꢀO1
2.291(1)
2.274(1)
1.543(3)
1.572(3)
1.831(4)
1.826(4)
1.808(4)
1.824(4)
1.65(5)
P2ꢀO2
74.0(2)
P1ꢀC11
P1ꢀC17
P2ꢀC23
P2ꢀC29
O1ꢀH1C
O2ꢀH1C
O1ꢀO2 b
H1AꢀH1B b
115.0(1)
114.4(4)
114.4(1)
118.4(1)
101.8(2)
103.4(2)
RuꢀP2ꢀO2
RuꢀP2ꢀC23
RuꢀP2ꢀC29
O2ꢀP2ꢀC23
O2ꢀP2ꢀC29
0.83(5)
2.467(4)
2.507(52)
a Cp* denotes the centroid of the ring.
b Non-bonded contacts.

R. Torres-Lubia´n et al. / Journal of Organometallic Chemistry 585 (1999) 68–82
81
presence of air, to give compounds 15% [1H-NMR: l
1.44 (q, 1.87, Cp*); 31P-NMR: l 37.1 (d, 43, JPH=368),
130.6 (t, 43)] and 17 [1H-NMR: l 1.40 (q, 1.46, Cp*);
31P-NMR: l 42.3 (t, 43, JPH=362), 136.2 (d, 43)].
CYT), Me´xico and the National Science Foundation.
J.R.T.L. would like to thank CONACYT for a grant
and M.A.P.S. would like to thank M. Cervantes for
assistance with some syntheses and Professor Robert J.
Angelici for helpful comments.
3.7. X-ray structure determinations of 6, 13, 18, and 20
Suitable single crystals for X-ray structure determina-
tions were obtained by vapor diffusion of n-hexane into
a CH2Cl2 solution of 20 at r.t. and after recrystalliza-
tion of 18 from CH2Cl2/hexane and 6 and 13 from
CHCl3/hexane. Selected crystals of the compounds were
mounted in capillary tubes and set up on a CAD4
Enraf–Nonius diffractometer. Experimental conditions
as well as crystallographic data are given in Table 1.
Two standard reflections were monitored periodically
and showed no change during data collection. Calcula-
tion for structures 6 and 20 were carried out using the
CRYSTALS [43] program, adapted to a PC. The struc-
tures of 13 and 18 were solved and refined using the
SHELX programs. An empirical absorption correction
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