Some new chain-like terdentate phosphines, their ruthenium(II) coordination chemistry and the activity of the cations [Ru(MeCN)3(PhP{CH2CH2P(p-X-C6H 4)2}2)]2+ (X=H, F, Me and OMe) as acetalization catalysts

Article abstract of DOI:10.1016/S0020-1693(99)00117-6

The new chain-like tritertiary phosphines PhP{CH₂CH₂P(p-X-C₆H₄) ₂}₂, (X=F, Me and OMe), phetpX, were prepared and characterized. These ligands react with cis-[RuCl₂(DMSO)₄] giving equilibrium mixtures of the eclipsed (ec) and staggered (st) isomers of the dinuclear complexes [Ru₂(μ-Cl)₃(phetpX)₂]Cl. The preparation and characterization of the tritertiary phosphines MesP{CH₂CH₂P(p-X-C₆H₄) ₂}₂ (Mes=mesityl, X=H and F), mesetpX, is also reported. They react with cis-[RuCl₂(DMSO)₄] giving equilibrium mixtures of corresponding uninuclear, [RuCl₂(mesetpX)], and dinuclear species, st-[Ru₂(μ-Cl)₃(mesetpX)₂]Cl, whose molecularities were established by determining their diffusion coefficients. The dissociation of st-[Ru₂(μ-Cl)₃(mesetph)₂]Cl to [RuCl₂(mesetph)] (K=1.8×10^-2 mol^-1) is endothermic (ΔH=32 kJ mol^-1) and favored by entropy (ΔS=75 J mol^-1). The complexes 'RuCl₂(pp₂)' (pp₂=phetph, and mesetph) react with CO giving fac-[RuCl₂(CO)(pp₂)] and fac-[RuCl(CO)₂(pp₂)]Cl as kinetic products. These complexes slowly rearrange to the thermodynamically stable products mer-[RuCl₂(CO)(pp₂)]. The complexes st-[Ru₂(μ-Cl)₃(phetpX)₂]Cl react with four equivalents of AgCF₃SO₃ in MeCN giving the corresponding salts [Ru(MeCN)₃(phetpX)](CF₃SO₃)₂. Their activities as catalysts for the acetalization of cyclo-hexanone with 1,2-dihydroxyethane and the trans-acetalization of cyclo-hexanone with 2,2-dimethyl-1,3-dioxolane are described.

Full text of DOI:10.1016/S0020-1693(99)00117-6

Inorganica Chimica Acta 290 (1999) 64–79
Some new chain-like terdentate phosphines, their ruthenium(II)
coordination chemistry and the activity of the cations
[Ru(MeCN)3(PhP{CH2CH2P(p-X-C6H4)2}2)]2+ (X=H, F, Me and
OMe) as acetalization catalystsꢀ
Qiongzhong Jiang, Heinz Ru¨egger, Luigi M. Venanzi *
Laboratorium fu¨r Anorganische Chemie, Uni6ersita¨tstrasse 6, Eidgeno¨ssische Technische Hochschule, CH-8092 Zu¨rich, Switzerland
Received 12 November 1998; accepted 15 February 1999
Abstract
The new chain-like tritertiary phosphines PhP{CH2CH2P(p-X-C6H4)2}2, (X=F, Me and OMe), phetpX, were prepared and
characterized. These ligands react with cis-[RuCl2(DMSO)4] giving equilibrium mixtures of the eclipsed (ec) and staggered (st)
isomers of the dinuclear complexes [Ru2(m-Cl)3(phetpX)2]Cl. The preparation and characterization of the tritertiary phosphines
MesP{CH2CH2P(p-X-C6H4)2}2 (Mes=mesityl, X=H and F), mesetpX, is also reported. They react with cis-[RuCl2(DMSO)4]
giving equilibrium mixtures of corresponding uninuclear, [RuCl2(mesetpX)], and dinuclear species, st-[Ru2(m-Cl)3(mesetpX)2]Cl,
whose molecularities were established by determining their diffusion coefficients. The dissociation of st-[Ru2(m-Cl)3(mesetph)2]Cl
to [RuCl2(mesetph)] (K=1.8×10−2 mol−1) is endothermic (DH=32 kJ mol−1) and favored by entropy (DS=75 J mol−1). The
complexes ‘RuCl2(pp2)’ (pp2=phetph, and mesetph) react with CO giving fac-[RuCl2(CO)(pp2)] and fac-[RuCl(CO)2(pp2)]Cl as
kinetic products. These complexes slowly rearrange to the thermodynamically stable products mer-[RuCl2(CO)(pp2)]. The
complexes st-[Ru2(m-Cl)3(phetpX)2]Cl react with four equivalents of AgCF3SO3 in MeCN giving the corresponding salts
[Ru(MeCN)3(phetpX)](CF3SO3)2. Their activities as catalysts for the acetalization of cyclo-hexanone with 1,2-dihydroxyethane
and the trans-acetalization of cyclo-hexanone with 2,2-dimethyl-1,3-dioxolane are described. © 1999 Elsevier Science S.A. All
rights reserved.
Keywords: Acetalization; Ruthenium complexes; Terdentate phosphine complexes
It has also become apparent that several of the
classical homogeneously catalyzed reactions, which are
normally carried out using complexes with didentate
phosphines, also proceed when the catalyst precursors
contain terdentate phosphines which can be either
tripodal, p3, e.g. CH3C(CH2PPh2)3, triphos [19], or
chain-like, pp2, e.g. PhP(CH2CH2CH2PPh2)2 (1a), ttp,
[12,20]. Furthermore, as found for the rhodium sol-
vento-complex [Rh(MeCN)3(triphos)](CF3SO3)3 [21] the
analogous compound [Ru(MeCN)3(triphos)](CF3SO3)2
[22] is a very active catalyst precursor for the acetaliza-
tion of a wide range of aldehydes and ketones [23]. The
latter complex is also an active catalyst for the hydro-
desulfurization reaction [24].
1. Introduction
Transition metal complexes with multidentate ter-
tiary phosphines have received increasing attention
[1–10] as they have found many applications in homo-
geneously catalyzed organic transformations, e.g. hy-
drogenation and hydroformylation of alkenes [1,11–15]
and hydrogenation of carbonyl compounds [16,17].
While much of this chemistry makes use of rhodium
complexes, in recent years ruthenium catalysts have
been increasingly used [18].
ꢀ Dedicated to Professor Helmut Werner on the occasion of his
65th birthday.
* Corresponding author. Tel.: +41-1-632 2851; fax: +41-1-632
1090.
Ruthenium complexes of composition ‘RuCl2(pp2)’
are readily obtained by refluxing toluene solutions of
E-mail address: venanzi@elwood.ethz.ch (L.M. Venanzi)
0020-1693/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0020-1693(99)00117-6

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
65
the appropriate terdentate phosphine with cis-
[RuCl2(DMSO)4] [22]. The pp2-containing compounds
are either dinuclear species of the type [Ru2(m-
Cl)3(pp2)2]Cl ([2]Cl) or uninuclear, five-coordinate, un-
charged complexes of the type [RuCl2(pp2)] (3) [22].
The ligand PhP(CH2CH2PPh2)2, phetph, (1a) forms the
dinuclear cation [Ru2(m-Cl)3(phetph)2]+(2a) [22], a well-
known structural type also readily formed by uniden-
tate phosphines [Ru2(m-Cl)3(PR3)6]+ [25–28] and
triphos [Ru2(m-Cl)3(triphos)2]+ [22].
As shown in an earlier publication [24], solutions of
the cation [Ru2(m-Cl)3(phetph)2]+ (2a) contain two iso-
meric forms, one in which the conformation of the two
terdentate ligands is eclipsed (ec) and one where they
are staggered (st), these two forms being in slow equi-
librium (Eq. (1)). However, bulkier terdentate phosphi-
(e) their use as catalysts for acetalization and trans-
acetalization reactions.
2. Experimental
2.1. Chemicals
The compounds vinyl chloride and 2,2%-azobis-iso-
butyronitrile (AIBN) were purchased from Fluka. The
compounds PHPh2 [36], PH(p-MeC6H4)2 [37],
PH(O)(p-MeOC6H4)2 [38], PH(O)(p-FC6H4)2 [39],
P(CHꢀCH2)2Ph [40], cis-[RuCl2(DMSO)4] [41] and
[Ru(m-Cl)3(phetph)2]Cl [24] were prepared as described
in the appropriate reference.
2.2. Physical measurements
The NMR spectra were measured on Bruker AC200,
AC250, AM300 and AMX500 spectrometers; chemical
shifts (l) are relative to TMS for 1H and 13C and
H3PO4 (85%) for 31P. The self-diffusion coefficients
were determined using the Stejskal–Tanner experiment
on a Bruker AM300 instrument equipped with a mi-
croprocessor-controlled gradient unit [42,43]. Use was
made of y/2–Z%–l–Z%–y–Z%–l–Z%-acquisition where
the echo time, 4Z%+2l, was kept to 71.0 ms, the two
pulsed field gradients being applied during l=5.5 ms.
The strength of the latter was varied in the course of
the experiment. The two-dimensional 31P–1H correla-
tions were recorded on the AMX500 spectrometer us-
ing the pulse sequence reported by Bax et al. [44,45],
whereas the 31P mediated 13C–1H correlation experi-
ment was specifically designed for establishing trans
connectivities in phosphine complexes [46]. The FAB
mass spectra were recorded on a FISON double-focus-
ing mass spectrometer (8 kV acceleration) using a m-
nitrobenzylic alcohol matrix and Cs+ ion bombard-
ment (35 kV at 2 mA) on a stainless steel target. The IR
spectra were measured on a Perkin–Elmer 883 spec-
trophotometer on the solid complexes in KBr or RbI
pellets. Conductivity data were obtained using a
Metrohm E527 Konduktometer on 10−3 M solutions
in MeNO2.
(1)
nes of this type, e.g. PhP{(CH2)3PPh2}2, ttp, or
PhP{(CH2)3PCy2}2, give uninuclear complexes of the
type [RuCl2(pp2)] (3) [22,29,30] whose coordination
polyhedra range from distorted trigonal bipyramidal
(tbp), e.g. [RuCl2{PhP(CH2CH2CH2PCy2)2}] [30], to
distorted square pyramidal (spy), e.g. [RuCl2-
{PhP(CH2CH2CH2PPh2)2}] [24]. Uncharged, doubly
bridged complexes of the type [Ru2Cl2(m-Cl)2(pp2)2] (4),
e.g. 4fac,trans, have also been postulated [31–35] but no
conclusive evidence has been presented to support such
formulations. However, it is possible that variations in
the steric nature of the substituents on the phosphorus
donors might lead to the formation of compounds of
type 4. Furthermore, electronic changes might provide
a better understanding of factors influencing the reac-
tivities of the species of composition ‘RuCl2(pp2)’.
Thus, further studies of complexes of the above types
appeared to be worthwhile.
2.3. Syntheses
All manipulations involving air-sensitive materials,
e.g. the phosphines, were performed under an N2 or Ar
atmosphere, using standard Schlenk techniques. The
Microanalytical Laboratory of the Organic Chemistry
Department at ETH Zurich performed the elemental
analyses and osmometric molecular weight determina-
tions. The irradiation source used for the photolysis
experiments was a quartz-jacketed high-pressure mer-
cury lamp. The photolysis experiments were performed
This paper reports (a) the preparation of several new
terdentate phosphines of pp2-type with substituents
which modify their electronic and steric properties; (b)
the synthetic and structural studies of their ruthen-
ium(II) chloro complexes; (c) an investigation of their
reactivities with CO; (d) the preparation of several
complexes of the type [Ru(MeCN)3(pp2)](CF3SO3)2 and

66
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
by externally irradiating the reactants contained in 50-
ml Duran–Schlenk tubes.
tilled under vacuum collecting the fraction with b.p. 0.1
90–110°C. Yield: 43.3 g. H NMR (CDCl3): l=6.98
1
(s, br, 2H, Hmeta), 2.44 (s, 6H, o-CH3), 2.40 (s, 3H,
p-CH3). 31P NMR (CDCl3): l=166.9 {40%,
PCl2(2,4,6-Me3C6H2)}, 161.1 {45%, PClBr(2,4,6-
Me3C6H2)}, 152.9 {15%, PBr2(2,4,6-Me3C6H2)}.
2.3.1. PH(p-FC6H4)2
Crude PH(O)(p-FC6H4)2 (38.5 g, 162 mmol) was
dissolved in ether (300 ml) and the solution was cooled
to 0°C with an ice bath and then Li[AlH4] (7.5 g, 0.198
mol) suspended in ether (150 ml) was added over 1 h.
The suspension was stirred at room temperature for 20
h. Hydrolysis was carried out by careful addition of
dilute (5–10%) HCl–H2O (300 ml). The organic phase
was transferred to another flask. The aqueous phase
was extracted with ether (2×100 ml). The combined
organic phases were dried over Na2SO4/MgSO4
overnight, filtered and the solvent removed under re-
duced pressure. The resulting residue was distilled un-
der vacuum and collected between 90–100°C (0.01
Torr). Yield: 26.8 g (75%). B.p. 0.1 90–96°C. Lit: b.p.
2.3.4. P(CHꢀCH2)2(2,4,6-Me3C6H2)
Gaseous CH2ꢀCHCl (86.4 g, 1.38 mol) was bubbled
into a suspension of Mg turnings (12.6 g, 0.52 mol) in
THF (350 ml) kept at 50–60°C for 4–5 h. Stirring was
continued at the same temperature for 16 h until all of
the Mg had reacted. The mixture of PX2(2,4,6-
Me3C6H2) (39.5 g, ca. 179 mmol), obtained as described
above, in THF (100 ml) was added dropwise over 1.5 h
to the stirred Grignard reagent which had been pre-
cooled with an ice-salt bath. The reaction mixture was
then refluxed for 16 h. After cooling with an ice-salt
bath, the reaction mixture was hydrolyzed with a solu-
tion of EDTA (167.2 g, 572 mmol) and NaOH (97.3 g,
2.43 mol) in deoxygenated water (400 ml). The organic
phase was separated off, and the aqueous phase was
washed with ether (150 ml) and pentane (100 ml). The
combined organic extracts were dried overnight over
Na2SO4/MgSO4 and then filtered off. The colorless
filtrate was concentrated under reduced pressure and
the product obtained from the resulting oil residue by
vacuum distillation. Yield: 23.4 g (ca. 64%). b.p. 0.15
85–95°C. 1H NMR (CDCl3): l=6.94 (s, br, 2H,
Hmeta), 6.60 (d×d×d, 2H, 2J(P,H)=18.6 Hz,
3J(H,H)=18.6 and 2.1 Hz, PCHꢀ), 5.71 (d×d×d,
1
2.0 110–113°C [47]. H NMR (CDCl3): l=7.45 (m,
4H, Hortho), 7.04 (d×d×d, 4H, Hmeta), 5.23 (d,
1J(P,H)=219.1 Hz, 1H, PH). 13C NMR (CDCl3): l=
163.35 (d, 1J(F,C)=244.9 Hz, Cpara), 135.88 (d×d,
3J(F,C)=7.9 Hz, 2J(P,C)=18.5 Hz, Cortho), 129.75
(d×d, 4J(F,C)=3.2 Hz, 1J(P,C)=10.1 Hz, Cipso),
2
3
115.86 (d×d, J(F,C)=21.0, J(P,C)=6.5 Hz, Cmeta).
31P NMR (CDCl3): l= −44.2.
This phosphine was also obtained in 38% yield as
described for PH(p-MeOC6H4)2 below [23].
2.3.2. PH(p-MeOC6H4)2
Solid PH(O)(p-MeOC6H4)2 (20.1 g, 76.7 mmol) was
kept at 150°C for ca. 30 min and the melt was then
heated gradually under vacuum (ca. 0.01 Torr) to 220°C
(bath temperature). The product was collected between
3
2
3
2H, J(P,H)=26.6 Hz, J(H,H)=1.7 Hz, J(H,H)=
12.1 Hz, CH2ꢀtrans to P), 5.47 (d×d×d, 2H,
3J(P,H)=11.6 Hz, J(H,H)=18.6 and 1.7 Hz, CH2ꢀcis
3
1
155–163°C (0.2 Torr). Yield: 6.4 g (34%). H NMR
to P), 2.53 (s, 6H, o-CH3), 2.32 (s, 3H, p-CH3). 13C
NMR (CDCl3): l=144.92 (d, 2J(P,C)=15.7 Hz,
Cortho), 139.75 (Cpara), 136.25 (d, 1J(P,C)=15.0 Hz,
(CDCl3): l=7.41 (m, 4H, Hortho), 6.87 (m, 4H, Hmeta),
5.20 (d, 1J(P,H)=218.9 Hz, 1H, PH), 3.80 (s, 6H,
p-OCH3). 13C NMR (CDCl3): l=159.89 (Cpara), 135.27
3
PCHꢀ), 129.46 (d, J(P,C)=4.9 Hz, Cmeta), 128.33 (d,
2
1
2
(d, J(P,C)=18.2 Hz, Cortho), 125.64 (d, J(P,C)=7.7
Hz, Cipso), 114.08 (d, 3J(P,C)=7.1 Hz, Cmeta), 55.16
(p-OCH3). 31P NMR (CDCl3): l= −43.5.
1J(P,C)=12.4 Hz, Cipso), 123.45 (d, J(P,C)=17.8 Hz,
3
CH2ꢀ), 23.38 (d, J(P,C)=17.3 Hz, o-CH3), 20.97 (p-
CH3). 31P NMR (CDCl3): l= −27.0.
2.3.3. PX2(2,4,6-Me3C6H2) (X=Cl, Br)
2.3.5. PH2(2,4,6-Me3C6H2)
Mesityl bromide (37.0 ml, 49.0 g, 246 mmol) in THF
(90 ml) was added dropwise, over 1 h, to a gently
refluxing suspension of Mg turnings (6.1 g, 251 mmol)
in THF (20 ml), after the reaction had been initiated by
adding BrCH2CH2Br (ca. 0.5 ml). The reaction mixture
was then refluxed for 2.5 h. The Grignard reagent thus
formed was cooled to −78°C with an acetone-dry ice
bath. A solution of PCl3 (65 ml, 745 mmol), in ether
(250 ml), was then added over 2 h. The reaction mix-
ture was then allowed to warm to room temperature
and then refluxed for 16 h. After filtration under Ar
through Teflon tube, the filtrate was evaporated to
dryness under reduced pressure. The residue was dis-
An Et2O solution (100 ml) of the mixture of
PX2(2,4,6-Me3C6H2) (26.5 g, ca. 0.12 mol), prepared as
described above, was added over 2 h to a suspension of
Li[AlH4] (9.4 g, 0.2477 mol) in Et2O (250 ml) cooled to
−78°C. The suspension was then gradually warmed up
and refluxed for 7 h. After the addition of pentane (100
ml), the reaction mixture was cooled with an ice-salt
bath and carefully hydrolyzed with dilute HCl. The
organic phase was collected and the aqueous residue
extracted with ether (100 ml). The combined organic
phases were dried over Na2SO4/MgSO4 overnight and
filtered. The filtrate was concentrated under reduced
pressure and the resulting residue was distilled under

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
67
high vacuum. Yield: 14.2 g (ca. 80%). B.p. 0.1 54–60°C.
1H NMR (CDCl3): l=7.00 (d, 2H, Hmeta), 3.83 (d,
1J(P,H)=206.7 Hz, 2H, PH2), 2.48 (s, 6H, o-CH3),
2.39 (s, 3H, p-CH3). 13C NMR (CDCl3): l=140.81 (d,
2J(P,C)=10.5 Hz, Cortho), 137.04 (Cpara), 128.45 (d,
Found: C, 76.00; H, 6.89. 1H NMR (CDCl3): l=7.35–
7.10 (m, 21H, aromatic), 2.35 (s, 6H, p-CH3), 2.33 (s,
6H, p-CH%), 2.10–1.60 (m, 8H, PCH2). 13C NMR
3
(CDCl3): (a) p-MeC6H4)2P–: l(C)=138.28 (Cpara),
138.17 (C%para), 134.74 (d, 1J(P,C)=13.0 Hz, Cipso),
134.42 (d, 1J(P,C)=12.8 Hz, Ci%pso), 132.29 (d,
1
3J(P,C)=1.7 Hz, Cmeta), 124.76 (d, J(P,C)=11.6 Hz,
Cipso), 23.08 (d, 3J(P,C)=9.5 Hz, o-CH3), 20.85 (s,
p-CH3). 31P NMR (CDCl3): l= −154.9 (d×m,
1J(P,H)=206.7 Hz).
2J(P,C)=18.3 Hz, C+Co%rtho), 128.98 (d, J(P,C)=6.9
3
Hz, C+Cmeta), 21.04 (p-CH3); (b) C6H5P–: l=137.06
1
2
(d, J(P,C)=15.8 Hz, Cipso), 132.49 (d, J(PC)=18.7
3
Hz, Cortho), 128.69 (Cpara), 128.15 (d, J(P,C)=6.5 Hz,
2.3.6. PPh{CH2CH2P(p-FC6H4)2}2, phetpf (1b)
Cmeta); (c) bridges: l=23.52 (t, 1J(P,C):2J(P,C):
1
PH(p-FC6H4)2 (2.77 g, 12.5 mmol), P(CHꢀCH2)2Ph
(1.0 ml, 0.97 g, 5.98 mmol) and KOtBu (0.1 g, 0.89
mmol) were dissolved in THF (30 ml). The resulting red
solution was then refluxed for 20 h and its color
changed to pale yellow. The solvent was removed under
reduced pressure and the oily residue was washed with
H2O (20 ml) and then consecutively extracted with
CH2Cl2 (2×50 ml) and toluene (2×20 ml). The com-
bined organic extracts were dried over Na2SO4 and,
after filtration, the solution was evaporated to dryness
under reduced pressure, leaving a viscous oil, which was
extracted with Et2O (2×70 ml). The extract was evapo-
rated to dryness under reduced pressure, leaving a pasty
solid. Yield: 2.60 g (72%). The 1H and 31P NMR
(CDCl3) showed that this compound was practically
13.6 Hz, CH2), 23.22 (t, J(P,C):2J(P,C):15.2 Hz,
CH2). 31P NMR (CDCl3): l= −16.7 (t, J(P,P)=29.1
3
Hz, Pc), −15.2 (d, Pt).
2.3.8. PPh{CH2CH2P(p-MeOC6H4)2}2, phetpome (1d)
PH(p-MeOC6H4)2 (2.67 ml, 3.02 g, 12.26 mmol) and
PPh(CH2ꢀCH2)2 (1.0 ml, 0.985 g, 6.07 mmol) were
dissolved in THF (20 ml). After the addition of KOtBu
(1.45 g, 12.9 mmol), an orange–yellow solution formed.
The reaction mixture was refluxed for 40 h and then
concentrated to a small volume under reduced pressure.
The residue was washed with H2O (10 ml), and consec-
utively extracted with CH2Cl2 (20 ml) and toluene (30
ml). The combined organic phases were dried overnight
over Na2SO4 and filtered. The filtrate was evaporated
to dryness under reduced pressure and the solid residue
was recrystallized from CH2Cl2/MeOH at −78°C. A
colorless oil formed when the crystals were allowed to
warm up to room temperature. This oil was dried under
vacuum overnight. After standing at room temperature
for several weeks, the oil solidified. Yield: 3.1 g (78%).
Anal. Calc. for C38H41O4P3 (654.66): C, 69.72; H, 6.31.
1
pure. H NMR (CDCl3): l=7.40–7.15 (m, 13H, aro-
matic), 7.00 (m, 8H, Hmeta of (p-F–C6H4)2P–), 2.04–
1.50 (m, 8H, PCH2). 13C NMR (CDCl3): (a)
(p-FC6H4)2P–: l=163.29 (d, 1J(FC)=249.3 Hz,
Cpara), 163.21 (d, 1J(F,C)=249.1 Hz, Cp%ara), 134.54,
(d×d, 3J(F,C)=7.8 Hz, 2J(P,C)=20.3 Hz, Cortho),
134.28 (d×d, 3J(FC)=7.8 Hz, 2J(P,C)=20.0 Hz,
4
1
1
Co%rtho), 133.52 (d×d, J(F,C)=2.0 Hz, J(P,C)=15.0
Found: C, 68.97; H, 6.27%. H NMR (CDCl3): l=
4
1
Hz, Cipso), 133.13 (d×d, J(F,C)=2.0 Hz, J(PC)=
10.7 Hz, Ci%pso), 115.68 (d×d, 2J(F,C)=20.8 Hz,
3J(P,C) 7.0 Hz, C+Cm% eta); (b) C6H5P–: 136.66 (d,
7.40–7.25 (m, 13H, aromatic), 6.86 (m, 8H, Hmeta of
p-MeOC6H4), 3.80 (s, 6H, CH3O), 3.79 (s, 6H, CH3O),
2.20–1.60 (m, br, 8H, PCH2). The J(P,C) coupling
constants could not be obtained from the 13C NMR
spectra as the central and terminal phosphines had
almost the same 31P chemical shift and, therefore, most
of the carbon resonances have to be interpreted in
terms of the X-part of an AB2X spin system. Only the
chemical shifts or the ranges are given here. 13C NMR
(CDCl3): (a) (p-MeOC6H4)2P: l=159.89 (Cpara), 159.81
(C%para), 134.17–133.30 (m, C+Co%rtho), 129.20–128.75
(m, C+Ci%pso), 113.85 (br, C+Cm% eta), 54.87 (p-CH3O);
(b) C6H5P: l=137.11 (Cipso), 132.25 (Cortho), 128.69
(Cpara); 128.19 (Cmeta); (c) –CH2: 23.95, 23.11. 31P
NMR (CDCl3): l= −16.9 (m, Pt and Pc).
1J(P,C)=16.0 Hz, Cipso), 132.54 (d, J(P,C)=18.4 Hz,
2
Cortho), 129.30 (Cpara), 128.52 (d, 3J(PC)=6.8 Hz,
C
meta); (c) bridges: 24.14 (t, 1J(P,C):2J(P,C)=13.4
Hz, for –PCH2–), 23.51 (t, 1J(P,C):2J(P,C)=15.2
Hz for –PCH2–). 31P NMR (CDCl3): l= −16.0 (d,
3J(P,P)=29.5 Hz, Pt); −17.6 (t, Pc).
2.3.7. PPh{CH2CH2P(p-MeC6H4)2}2, phetpme (1c)
PH(p-MeC6H4)2 (1.28 g, 5.98 mmol), PhP(CHꢀCH2)2
(0.475 g, 2.93 mmol) and KOtBu (0.1 g, 0.89 mmol)
were dissolved in THF (30 ml). The orange–red solu-
tion was refluxed for 24 h whereby the color changed to
pale yellow. The solvent was removed under reduced
pressure and the resulting white solid was stirred in
MeOH (20 ml) at 60°C for 30 min. The MeOH suspen-
sion was kept overnight at −78°C. The white solid
thus formed was filtered off and dried under vacuum
overnight at room temperature. Yield: 1.63 g (94%).
Anal. Calc. for C38H41P3 (590.66): C, 77.27; H, 7.00%.
2.3.9. P(2,4,6-Me3C6H2)(CH2CH2PPh2)2, mesetph (1e)
P(CHꢀCH2)2(2,4,6-Me3C6H2) (2.99 g, 14.64 mmol),
PHPh2 (5.48 g, 29.3 mmol) and KOtBu (ca. 0.2 g, 1.78
mmol) were dissolved in THF (70 ml) and the resulting
orange–red solution was refluxed for 24 h. The result-
ing pale yellow solution was concentrated to dryness

68
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
under reduced pressure and the residual oil was first
washed with HCl–H2O and then extracted with
CH2Cl2. The extract was dried over MgSO4/Na2SO4,
the solvent was removed under reduced pressure and
the resulting white solid was recrystallized from
CH2Cl2/ether/hexane at −78°C. Yield: 7.8 g (92%).
Anal. Calc. for C37H39P3 (576.64): C, 77.07; H, 6.82.
Found: C, 76.30; H, 6.925. 1H NMR (CDCl3): l=
7.30–7.05 (m, br, 20H, aromatic), 6.81 (s, br, 2H,
Me3C6H2), 2.35 (s, 6H, o-CH3), 2.25 (s, 3H, p-CH3),
2.10–1.70 (m, 8H, PCH2). 13C NMR (CDCl3): (a) Ph2P:
l=138.48 (d, 1J(P,C)=13.6 Hz, Cipso), 138.16 (d,
of phetpf (6 ml×0.0614 M=0.368 mmol) was added
over 5 min, at room temperature. The reaction mixture
was then refluxed for 24 h. The pale yellow solid thus
formed was filtered off, recrystallized from CH2Cl2/
ether and dried at 80°C for 14 h. Yield: 0.182 g (63%).
M.p. 262–264°C dec. The microanalytical data are
consistent with the presence of two molecules of crystal
water. Anal. Calc. for C68H62Cl4F8O2P6Ru2: C, 51.27;
H, 3.92. Found: C, 50.43; H, 3.84%, 31P NMR
(CHCl3): (st-isomer) l=98.5 (t, Pc, 2J(Pc,Pt, =22.6
Hz); 69.4 (d, Pt); (ec-isomer) l=98.7 (d×d, Pc,
2J(Pc,Pt1), =22.0 Hz, 2J(Pc,Pt2)=22.2 Hz), 70.1 (d×d,
2
2
1J(P,C)=13.6 Hz, Ci%pso), 132.81 (d, J(P,C)=18.3 Hz,
Pt1, J(Pt1,Pt2)=31.1 Hz), 66.9 (d×d, Pt2).
Cortho), 132.60 (d, 2J(P,C)=18.5 Hz, C%ortho), 128.58
(Cpara), 128.48 (Cp%ara), 128.37 (d, 3J(P,C)=6.5 Hz,
Cmeta); (b) Mes: l=144.87 (d, 2J(P,C)=14.4 Hz,
Cortho), 139.30 (Cpara), 129.72 (d, 3J(P,C)=3.5 Hz,
2.3.12. [Ru2(v-Cl)3(phetpme)2]Cl ([2c]Cl)
cis-[RuCl2(DMSO)4] (0.7176 g, 1.481 mmol) and
phetpme (0.8834 g, 1.496 mmol) were suspended in
toluene (30 ml) and the mixture refluxed for 24 h. The
suspension was allowed to stand overnight at room
temperature and all the solid redissolved. The solution
was evaporated to dryness under reduced pressure and
the residual solid was subjected to chromatography on
3
Cmeta), 23.32 (d, J(P,C)=18.6 Hz, o-CH3), 20.90 (p-
2
CH3); (c) –PCH2: l=25.28 (d×d, J(P,C)=20.3 Hz,
1J(P,C)=13.6 Hz), 22.22 (t, 1J(P,C):2J(P,C):15.2
Hz). The 13C signal for Cipso of 2,4,6-MeC6H2-group is
probably masked by other signals. 31P NMR (CDCl3):
l= −27.8 (t, 3J(P,P)=34.7 Hz, Pc), −12.9 (d, Pt).
a
silica gel column with CH2Cl2/acetone/MeOH
(10:10:1) as eluents. The orange–yellow eluate was
evaporated to dryness under reduced pressure. The
residue was recrystallized from CH2Cl2/ether/hexane.
The yellow solid was dried at 60°C for 20 h. Yield: 0.81
2.3.10. PMes{CH2CH2P(p-FC6H4)2}2, mesetpf (1f)
PH(p-FC6H4)2 (1.81 ml, 2.17 g, 9.78 mmol),
PMes(CHꢀCH2)2 (1.0 ml, 0.985 g, 4.824 mmol), and
AIBN (0.03 g, 0.183 mmol) were irradiated at 110°C
for 20 h. The volatile components were removed by
heating the reaction mixture at 120°C under vacuum
(ca. 0.1 Torr) for 3 h. The 1H, 13C and 31P NMR
spectra of the product, a sticky solid, showed that it
g
(70%). M.p. 235–237°C dec. Anal. Calc. for
C76H86Cl4O2P6Ru2: C, 58.57; H, 5.55; Cl, 9.08. Found:
C, 59.05; H, 5.83; Cl, 9.23%. 31P NMR (CHCl3): (st-
isomer) l=99.0 (t, Pc,2J(Pc,Pt, =23.3 Hz), 68.4 (d, Pt);
(ec-isomer) l=98.3 (d×d, Pc, 2J(Pc,Pt1, =24.0 Hz,
1
2
was practically pure. H NMR (CDCl3): l=7.36–7.28
2J(Pc,Pt2)=23.4 Hz,), 69.2 (d×d, Pt1, J(Pt1,Pt2)=29.0
(m, 8H, Hortho of p-FC6H4), 7.02 (m, 8H, Hmeta of
p-FC6H4), 6.87 (s, br, 2H, Hmeta of 2,4,6-Me3C6H2),
2.42 (s, 6H, o-CH3), 2.30 (s, 3H, p-CH3), 2.10–1.70 (m,
8H, PCH2). 13C NMR (CDCl3): (a) (p-FC6H4)2P–:
l=163.21 (d, 1J(F,C)=248.8 Hz, Cpara), 163.12 (d,
Hz), 65.4 (d×d, Pt2).
2.3.13. [Ru2(v-Cl)3(phetpome)3]Cl ([2d]Cl)
cis-[RuCl2(DMSO)4] (0.4554 g, 0.940 mmol) and
phetpome (0.621 g, 0.949 mmol) were suspended in
toluene (30 ml) and the mixture refluxed for 14 h. The
yellow solid thus formed was filtered off, washed first
with toluene (5 ml) and then ether (2×5 ml). The
yellow product was dried at 70°C for 20 h. Yield: 0.61
g (76%). M.p. 233–235°C dec. The elemental analysis
was consistent with a product, which contained two
molecules of crystal water. Anal. Calc. for
C76H86Cl4O10P6Ru2: C, 54.04; H, 5.13; Cl, 8.39. Found:
C, 54.03, H, 5.18; Cl, 8.65%. 31P NMR (CHCl3): (st-
isomer) l=98.3 (t, Pc, 2J(Pc,Pt)=23.6 Hz); 67.1 (d, Pt);
(ec-isomer) l=99.0 (d×d, Pc, 2J(Pc,Pt1)=24.4 Hz,
3
1J(F,C)=248.7 Hz, Cp%ara), 134.51 (d×d, J(F,C)=8.0
Hz, 2J(P,C)=20.0 Hz, Cortho), 134.25 (d×d,
3J(F,C)=7.7 Hz, 2J(P,C)=19.8 Hz, C%ortho), 133.66
(d×d, 4J(F,C)=2.7 Hz, 1J(P,C)=14.4 Hz, Cipso),
133.33 (d×d, 4J(F,C)=3.7 Hz, 1J(P,C)=14.7 Hz,
2
3
Ci%pso), 115.58 (d×d, J(F,C)=20.8 Hz, J(P,C)=7.2
2
Hz, C+Cm% eta); (b) MesP: l=144.78 (d, J(P,C)=14.4
Hz, Cortho), 139.34 (Cpara), 129.85 (d, J(P,C)=3.7 Hz,
Cmeta), 23.30 (d, J(P,C)=18.5 Hz, o-CH3), 20.84 (p-
3
3
2
CH3); (c) –PCH2: l=25.73 (d×d, J(P,C)=20.7 Hz,
1J(P,C)=13.7 Hz), 22.02 (t, 2J(P,C):1J(PC)=15.6
Hz). The 13C signal for Cipso of 2,4,6-MeC6H2 could not
be observed. 31P NMR (CDCl3): l= −23.2 (t,
3J(P,P)=36.1 Hz, Pc), −15.7 (d, Pt).
2J(Pc,Pt2)=24.7 Hz); 69.2 (d×d, Pt1, J(Pt1,Pt2)=28.3
Hz), 64.7 (d×d, Pt2).
2
2.3.14. [Ru2(v-Cl)3(mesetph)2]Cl ([2e]Cl), and
[RuCl2(mesetph)] (3e)
cis-[RuCl2(DMSO)4] (0.201 g, 0.415 mmol) and me-
2.3.11. [Ru2(v-Cl)3(phetpf)2]Cl ([2b]Cl)
cis-[RuCl2(DMSO)4] (0.176 g, 0.3632 mmol) was sus-
pended in toluene (20 ml) and a toluene stock solution
setph (0.240 g, 0.416 mmol) were suspended in 50 ml of

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
69
toluene and the mixture, after refluxing for 24 h, was
cooled down to room temperature, the orange–yellow
solid thus formed was filtered off and washed first with
toluene (2×5 ml) and then ether (2×5 ml). The
product was dried at 60°C under vacuum for 12 h.
Yield: 0.218 g (70%). Anal. Calc. for C74H78Cl4P6Ru2:
C, 59.36; H, 5.25; Cl, 9.47. Found: C, 59.17; H, 5.12; C,
2J(Pt1,Pt2)=27.4 Hz); 34.1 (d×d, Pt2). 6a: l=91.7 (t,
2J(Pc,Pt)=10.6 Hz); 30.4 (d, Pt).
2.3.17. mer-[RuCl2(CO)(phetph)] (7a)
An orange–red solution of [Ru2(m-Cl)3(phetph)2]-
Cl·2H2O ([2a]Cl), (0.2670 g, 0.1842 mmol) in CH2Cl2
(15 ml) and MeOH (15 ml) was warmed up to 40°C, and
CO was bubbled through the stirred solution for 24 h.
Yield: 0.19 g (70%). Anal. Calc. for C35H33Cl2OP3Ru: C,
57.23; H, 4.53. Found: C, 57.72; H, 4.75%. \M=0 V−1
cm2 mol−1 (MeNO2). 13C NMR (CD2Cl2): l=199.76
2
9.24%. 31P NMR (CHCl3): (3e) 131.7 (t, Pc, J(Pc,Pt),
80.6 (d, Pt)=13.5 Hz); (st-[2e]Cl) l=104.3 (t, Pc,
2
2J(Pc,Pt1)=17.4 Hz, J(Pc,Pt2)=17.4 Hz); 64.8 (d×d,
2
Pt1, J(Pt1,Pt2)=31.1 Hz), 63.4 (d×d, Pt2).
2
(q, CO, J(P,C)cis=11 Hz. 31P NMR (CD2Cl2): l=
2
105.5 (t, Pc, J(Pc,Pt)=9.2 Hz); 36.5 (d, Pt).
2.3.15. [Ru2(v-Cl)3(mesetpf)2]Cl ([2f]Cl), and
[RuCl2(mesetpf)] (3f)
2.3.18. fac-[RuCl2(CO)(mesetph)] (5e), and
cis-[RuCl2(DMSO)4] (0.658 g, 1.36 mmol) was sus-
pended in toluene (25 ml). A stock solution of mesetpf
(18 ml×0.08 M=1.43 mmol) was added and the reac-
tion mixture heated to reflux. The yellow solid, which
formed within 1 h disappeared on refluxing for 14 h,
giving an orange–red solution. This was evaporated to
dryness under reduced pressure and the residue was
subjected to chromatography over silica gel using
CH2Cl2/acetone/MeOH (10:10:1) as the eluent. The or-
ange–yellow eluate was evaporated to dryness under
reduced pressure and the resulting solid washed with
ether and dried at 70°C for 16 h. Yield: 0.75 g (67%).
M.p. 218–220°C dec. The microanalytical data are
consistent with the presence of two molecules of crystal
water. Anal. Calc. for C74H74Cl4F8O2P6Ru2: C, 53.00;
H, 4.45; Cl, 8.46. Found: C, 53.25; H, 4.53; Cl, 8.49%.
31P NMR (CHCl3): (3f) l=128.2 (t, Pc, 2J(Pc,Pt)=13.5
Hz); 78.2 (d, Pt); (st-[2e]Cl) l=103.2 (t, Pc, 2J(Pc,Pt1)=
2J(Pc,Pt2)=16.7 Hz, 65.3 (d×d, Pt1,2J(Pt1,Pt2)=32.2
Hz), 64.3 (d×d, Pt2).
fac-[RuCl(CO)2(mesetph)]Cl (6e)
(a) A mixture of these complexes was obtained as
described for the mixture of fac-[RuCl2(CO)(mesetpf)]
(5f), and fac-[RuCl(CO)2(mesetpf)]Cl (6f) (see below).
Yield: (ca. 93%). Anal. Calc. for C38H39Cl2OP3Ru (5e):
C, 58.77; H, 5.06. Calc. for C39H39Cl2O2P3Ru (6e): C,
58.22; H, 4.89. Found: C, 56.82; H, 5.15%. \M=15.1
V−1 cm2 mol−1 (MeNO2). 13C NMR (CDCl3); 5e:
l=197.75 (d×t, CO, 2J(P,C)trans=114.4 Hz,
2J(P,C)cis=10.4 Hz). 31P NMR (CD2Cl2); 5e: l=96.9
(d×d, Pc, 2J(Pc,Pt1)=10.6 Hz, 2J(Pc,Pt2)=14.6 Hz);
2
50.3 (d×d, Pt1, J(Pt1,Pt2)=27.4 Hz); 38.9 (d×d, Pt2).
(b) A mixture of [RuCl2(mesetph)] and [Ru2(m-Cl)3
(mesetph)2]Cl (0.240 g, 0.160 mmol), prepared as de-
scribed above, was dissolved in CH2Cl2 (15 ml) and
MeOH (15 ml). The solution was warmed up to 40°C,
while CO was slowly bubbled through the orange solu-
tion for 2 h. The reaction mixture was then stirred for
another 20 h. The 31P NMR spectrum of the solution
showed that it contains only the cationic dicarbonyl
complex [RuCl(CO)2(mesetph)]Cl (6e). The solution was
filtered through Celite and the filtrate was divided into
two portions.
2.3.16. fac-[RuCl2(CO)(phetph)] (5a) and
fac-[RuCl(CO)2(phetph)]Cl (6a)
[Ru2(m-Cl)3(phetph)2]Cl · 2H2O, [2a]Cl (0.1706 g,
0.1177 mmol) in CH2Cl2 (10 ml) was put in a glass vessel
and placed in an autoclave. After CO had been pressur-
ized to 100 bar, the autoclave was shaken at room
temperature for 20 h. After filtering through Celite, the
pale yellow solution was evaporated to dryness under
reduced pressure. The residue was recrystallized from
CH2Cl2/ether/hexane. The pale yellow solid was dried at
room temperature overnight. Yield: 0.161 g (93%).
\M=17 V−1 cm2 mol−1 (MeNO2). Spectroscopic in-
vestigations of this solid (see text) show that it is a 1:1
mixture of 5a and 6a. This solid also contains small
amounts of 7a which can be better obtained as described
below. 13C NMR (CD2Cl2). 5a: l=196.74 (d×t, CO,
2.3.19. fac-[RuCl(CO)2(mesetph)]Cl (6e)
One half of the above filtrate was evaporated to
dryness under reduced pressure and the solid residue
was recrystallized from CH2Cl2/ether/hexane. Yield:
0.125 g (ca. 47%). The elemental analysis is consistent
with the presence of one molecule of crystal water. Anal.
Calc. for C39H41Cl2O3P3Ru: C, 56.94; H, 5.02; Cl, 8.62.
Found: C, 56.72; H, 5.14; Cl, 9.35%. \M=51.3 V−1
cm2 mol−1 (MeNO2). 13C NMR (CD2Cl2): l=190.85
(X part of an AA%MX spin system, CO). 31P NMR
(CDCl3): l=89.9 (t, Pc, 2J(Pc,Pt)=8.4 Hz); 34.2 (d, Pt).
2.3.20. fac-[RuCl2(CO)(mesetph)] (5e), and
mer-[RuCl2(CO)(mesetph)] (7e)
To the other half of the above filtrate MeOH (15 ml),
ether (30 ml) and hexane (15 ml) were added. The
mixture was left overnight at room temperature. The
resulting yellow solid was filtered off, washed with ether
2
2J(P,C)trans=113.6 Hz, J(P,C)cis=12.0 Hz). 6a: l=
190.2 (m, X-part of AA%MX spin system, CO). 31P
NMR (CD2Cl2). 5a: l=92.8 (d×d, Pc, 2J(Pc,Pt1)=
12.8 Hz, 2J(Pc,Pt2)=16.4 Hz); 50.4 (d×d, Pt1,

70
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
(10 ml) and dried overnight at room temperature.
Yield: 0.075 g (ca. 30%). Anal. Calc. for C38H39Cl2
OP3Ru: C, 58.77; H, 5.06. Found: C, 58.54; H, 5.16%.
\M=3.8 V−1 cm2 mol−1 (MeNO2). After the
separation of pure 5e, the mother liquor was evapo-
rated to dryness under reduced pressure. The residue
was recrystallized from CH2Cl2/ether/hexane and a yel-
low solid (0.021 g) was obtained. The 31P NMR of a
CDCl3 solution of this solid showed that it contained
fac-[RuCl2(CO)(mesetph)] (5e), (ca. 80%) and mer-
[RuCl2(CO)(mesetph)] (7e), (ca. 20%). 31P NMR
(CDCl3) 7e: l=79.9 (s, Pc); 34.8 (s, Pt).
(5f) (ca. 25%). The microanalytical data are consistent
with the presence of one molecule of crystal water. Anal.
Calc. for C38H37Cl2F4O2P3Ru: C, 52.66; H, 4.30.
Found: C, 52,68; H, 4.47%. \M=2.9 V−1 cm2 mol−1
(MeNO2). 13C NMR 7f: l=201.26 (d×t, CO,
2
2J(Pt,C)cis=11.0 Hz, J(Pc,C)cis=9.8 Hz).
2.3.23. fac-[Ru(MeCN)3(phetpf)](CF3SO3)2 (8b)
This complex was prepared as described for 8c be-
low. Yield 91%. The microanalytical data are consistent
with the presence of one molecule of crystal water.
Anal. Calc. for C42H40F10N3O7P3RuS2: C, 43.99; H,
3.52; N, 3.66. Found: C, 44.43; H, 3.68; N, 3.50%. IR
(KBr, cm−1): w(CN)=2316 (w), 2287 (w); w(CF3SO3)
2.3.21. fac-[RuCl2(CO)(mesetpf)] (5f) and
fac-[RuCl(CO)2(mesetpf)]Cl (6f)
1
=1258 (vs), 1162 (s), 1031 (s). The H, 19F and 31P
(a) A mixture of [RuCl2(mesetpf)] and [Ru2(m-Cl)3
(mesetpf)2]Cl (0.1711 g, 0.1038 mmol), obtained as de-
scribed above, was dissolved in CH2Cl2 (20 ml), and CO
was bubbled slowly through the resulting orange solu-
tion for ca. 24 h. After filtration, hexane (100 ml) and
ether (100 ml) were added to the filtrate. The resulting
pale yellow solid was filtered off and dried under vac-
uum for 30 min. Yield: 0.152 g (86%). The elemental
analysis is consistent with the presence of one molecule
of crystal water. Anal. Calc. for C38H37Cl2F4O2P3Ru: C,
52.67; H, 4.30; Cl, 8.18. Found: C, 52.96; H, 4.35; Cl,
8.09%. \M=12.7 V−1 cm2 mol−1 (MeNO2). 31P NMR
NMR spectra, in CDCl3, show the presence of
[Ru(MeCN)3(phetpf)](CF3SO3)2
(8b)
(40%)
and
[Ru(CF3SO3)(MeCN)2(phetpf)](CF3SO3) (60%) (9b) (see
1
below). H NMR (CDCl3): l=7.80–6.40 (m, br, 21H,
aromatic); 3.40–0.70 (m, br, ca. 19H, PCH2, CH3CN,
H2O) including 2.91 (CH3CNcoord,ax), 2.02 (CH3CNfree),
1.96 (CH3CNcoord,eq). 19F NMR (CDCl3): l= −78.32
(CF3SO3,free),
−78.64 (CF3SO3,coord),
−107.78,
−108.09, −108.76, −108.88 (p-F-C6H4). 19F NMR
(CDCl3/MeCN): l= −78.88 (CF3SO3,free), −109.33,
−109.60 (p-F-C6H4). 31P{1H} NMR (CDCl3): l=96.9
2
(t, Pc, J(Pc,Pt)=17.9 Hz); 60.6 (d, Pt).
2
(CDCl3); 5f: l=97.3 (d×d, Pc, J(Pc,Pt)=10.1 Hz);
2
50.5 (d×d, Pt1, J(Pt1,Pt2)=27.4 Hz); 39.0 (d×d, Pt2).
2.3.24. fac-[Ru(CF3SO3)(MeCN)2(phetpf)](CF3SO3)
(9b)
(b) A mixture of [RuCl2(mesetpf)] and [Ru2(m-Cl)3
(mesetpf)2]Cl (0.210 g, 0.128 mmol) was dissolved in
CH2Cl2 (15 ml) and MeOH (15 ml) and CO was slowly
bubbled through the orange–yellow solution for 24 h at
40°C. A 31P NMR spectrum of this solution showed
that it contained a mixture of fac-[RuCl2(CO)(mesetpf)]
(5f), (ca. 20%), mer-[RuCl2(CO)(mesetpf)] (7f) (ca. 20%)
and fac-[RuCl(CO)2(mesetpf)]Cl (6f) (ca. 60%). This
solution was filtered through Celite and stored at 0°C
for 48 h after adding ether (50 ml) and hexane (100 ml).
The orange crystals thus formed were filtered off and
dried at room temperature for 12 h. Yield: 0.095 g
(43%). The 31P NMR spectrum of this product, in
CDCl3, shows that the solid contains only
[RuCl2(CO)(mesetpf)] (5f). 31P NMR 6f: l=90.4 (t, Pc,
2J(Pc,Pt)=7.5 Hz); 34.7 (d, Pt).
This complex was prepared by heating 8b above
under vacuum (ca. 0.1 Torr) at 85°C for 16 h. Its
microanalytical data are consistent with the presence
of one molecule of crystal water. Anal. Calc. for
C44H49F6N2O7P3RuS2: C, 43.45; H, 3.37; N, 2.53.
Found: C, 43.20; H, 3.23; N, 2.50%. IR (KBr, cm−1):
w(CN)=2318 (w), 2285 (w); w(CF3SO3)=1259 (vs),
1163 (s), 1030 (s). 1H NMR (CDCl3): l=7.80–7.26 (m,
br 13H, aromatic); 7.13–7.09 (m, 24, m-H of p-F-
C6H4); 6.72–6.69 (m, 4H, m-H of p-F-C6H4); 3.50–2.05
(m, br, ca. 8H, PCH2); 1.83 (s, 6H, CH3CNeq); 1.80–
0.70 (m, br, ca. 2H). 19F NMR (CDCl3): l −78.29
(CF3SO3,free), −78.65 (CF3SO3,coord); −108.76 (p-F-
C6H4); −108.88 (p-F-C6H4). 31P{1H} NMR (CDCl3):
2
l=96.6 (t, Pc, J(Pc,Pt)=18.3 Hz); 59.2 (d, Pt).
2.3.22. fac-[RuCl2(CO)(mesetpf)] (5f), and
mer-[RuCl2(CO)(mesetpf)] (7f)
2.3.25. fac-[Ru(MeCN)3(phetpme)](CF3SO3)2 (8c)
After the separation of [RuCl2(CO)(mesetpf)] (5f), as
described above, its mother liquor was evaporated to
dryness under reduced pressure. The residue was recrys-
tallized from MeOH/ether/hexane giving a pale yellow
solid. Yield: 0.09 g (41%). Its 31P NMR spectrum, in
CDCl3, showed the presence of mer-[RuCl2(CO)-
(mesetpf)] (7f) (ca. 75%) and fac-[RuCl2(CO)(mesetpf)]
Solid AgCF3SO3 (0.213 g, 0.830 mmol) was added to
a solution of [Ru2(v-Cl)3(phetpme)2]Cl · 2H2O (0.377 g,
0.179 mmol) in MeCN (25 ml). A precipitate of AgCl
formed immediately. The suspension was refluxed for
ca. 24 h and the solid filtered off. The solution was
evaporated to dryness under reduced pressure, the
residue dissolved in MeCN and the suspension filtered

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
71
again. The filtrate was evaporated to a volume of ca.
2–3 ml under reduced pressure and Et2O (100 ml)
added. The product was filtered off and dried overnight
at room temperature over P4O10. Yield 0.398 g (93%).
The microanalytical data are consistent with the pres-
ence of a molecule of water of crystallization. Anal.
Calc. for C46H52F6N3O7P3RuS2: C, 48.46; H, 4.65; N,
3.62. Found: C, 48.59; H, 4.63; N, 3.73%. IR (KBr,
cm−1) w(CN)=2314 (w), 2283 (w), w(CF3SO3)=1262
(vs), 1192 (s), 1155 (s), 1029 (s). The 31P and 19F NMR
spectra of a CDCl3 solution of this complex shows the
presence of fac-[Ru(MeCN)3(phetpme)](CF3SO3)2 (8c)
(63%) and of fac-[Ru(CF3SO3)(MeCN)2(phetpme)]-
(CH3CNcoord,eq). 19F NMR (CDCl3): l= −78.34
(CF3SO3,free); −78.53 (CF3SO3,coord). 19F NMR
(CDCl3/MeCN): l= −78.39 (CF3SO3,free). 31P{1H}
NMR (CDCl3): l=97.1 (t, Pc, 2J(Pc,Pt)=18.6 Hz); 58.9
(d, Pt).
2.3.28. fac-[Ru(CF3SO3)(MeCN)2(phetpome)](CF3SO3)
(9d)
This complex was obtained by heating 8d above at
85°C under vacuum (ca. 0.1 Torr) for ca. 24 h. Its
elemental analysis is consistent with the presence of one
molecule of water of crystallization. Anal. Calc. for
C44H49F6N2O11P3RuS2: C, 45.80; H, 4.28; N, 2.43.
Found: C, 44.72; H, 4.26; N, 2.13%. IR (KBr, cm−1):
w(CN)=2314 (w), 2286 (w); w(CF3SO3)=1256 (vs),
1186 (s), 1161 (s), 1029 (s). 1H NMR (CDCl3): l=7.80–
7.10 (m, br, 13H, aromatic); 6.88 (d, 4H, m-H of
1
(CF3SO3) (9c) (37%). H NMR (CDCl3): l=7.80–6.70
(m, 21H, aromatic); 3.60–0.80 (m, br, 31H, PCH2,
CH3CN, H2O) of which 2.87 (CH3CNax); 2.30 (p-CH3);
2.24 (p-CH3); 2.22 (p-CH3); 2.02 (p-CH3); 1.89
(CH3CNeq). 19F NMR (CDCl3): l= −78.35 (CF3-
SO3,free); −78.56 (CF3SO3,coord). 19F NMR (CDCl3/
MeCN): l= −78.42 (CF3SO3,free). 31P{1H} NMR
(CDCl3): l=96.9 (t, Pc, 2J(Pc,Pt)=17.9 Hz); 60.6
(d, Pt).
3
p-MeOC6H4, J(H,H)=8.2 Hz); 6.46 (d, 4H, m-H of
3
p-MeOC6H4, J(H,H)=8.2 Hz); 3.74 (s, 6H, p-CH3O);
3.71 (s, 6H, p-CH3O); 3.50–2.00 (m, br, ca, 8H, PCH2);
1.79 (s, 6H, CH3CNcoord,eq); 1.70–0.70 (m, br, ca. 2H)
19F NMR (CDCl3): l= −78.29 (CF3SO3,free); −78.53
(CF3SO3,coord). 31P{1H} NMR (CDCl3): l=104.7 (t, Pc,
2J(Pc,Pt)=20.1 Hz); 56.9 (d, Pt).
2.3.26. fac-[Ru(CF3SO3)(MeCN)2(phetpme)](CF3SO3)
(9c)
2.4. Reactions of cyclo-hexanone with
1,2-dihydroxyethane
This complex was prepared by heating 8c at 110°C
under vacuum (ca. 0.1 Torr) for 16 h. The microanalyti-
cal data are consistent with the presence of one
molecule of water of crystallization. Anal. Calc. for
C44H49F6N2O7P3RuS2: C, 48.49; H, 4.53; N, 2.57. Found:
C, 46.86; H, 4.55; N, 1.82%. IR (KBr, cm−1): w(CN)=
2317 (w), 2286 (w); w(CF3SO3)=1255 (vs), 1192 (s), 1160
(s), 1030 (s). 1H NMR (CDCl3): l=7.85–7.05 (m, 17H,
aromatic); 6.80–6.65 (m, 4H, m-H of p-Tol); 3.50–0.75
(m, br, ca. 28H, PCH2, CH3CN, p-CH3) of which
2.26 (p-CH3), 2.21 (p-CH3); 1.73 (CH3CNeq). 19F
NMR (CDCl3): l= −78.31 (CF3SO3,free); −78.56
(CF3SO3,coord). 31P{1H} NMR (CDCl3): l=104.5 (t, Pc,
2J(Pc,Pt)=20.6 Hz); 56.9 (d, Pt).
The ketone (10 mmol), the catalyst (5×10−4 mmol)
and mesitylene (as internal standard) in CH2Cl2 (5 ml)
were thermostated to 30°C and the glycol (12 mmol) and
CH(OiPr)3 (11 mmol) were added to the stirred solution.
GC was used to follow the course of the reaction. After
the reaction had gone to completion the solvent was
removed using a rotary evaporator. The product, after
purification by fractional distillation, was characterized
1
by H and 13C NMR. Yields were determined by GC.
2.5. Reactions of cyclo-hexanone with
2,2-dimethyl-1,3-dioxolane
2.3.27. fac-[Ru(MeCN)3(phetpome)](CF3SO3)2 (8d)
This complex was prepared as described for 8c above.
Yield 92%. Its elemental analysis is consistent with the
presence of one molecule of water of crystallization.
Anal. Calc. for C46H52F6N3O11P3RuS2: C, 46.23; H,
4.39; N, 3.52. Found: C, 45.33; H, 4.24; N, 3.36%. IR
(KBr, cm−1): w(CN)=2315 (w), 2285 (w); w(CF3SO3)=
These reactions were carried out as described above
replacing the glycol and orthoformate with the dioxo-
lane (11 mmol).
3. Results and discussion
3.1. Phosphines
1262 (vs), 1184 (s), 1154 (s), 1028 (s). The 1H, 19F and 31
P
NMR spectra show that solutions in CDCl3 contain
fac-[Ru(MeCN)3(phetpome)](CF3SO3)2 (8d) (ca. 62%)
The new terdentate chain-like phosphines of the type
R%P(CH2CH2PR2)2 (1b–f), pp2, were prepared using the
route shown in Eq. (2) [31–35].
and
fac-[Ru(CF3SO3)(MeCN)2(phetpome)](CF3SO3)
1
(9d) (ca. 38%). H NMR (CDCl3): l=7.80–6.40 (m,
21H, aromatic); 3.77, 3.74, 3.72 and 2.71 (p-CH3O);
3.40–0.80 (m, br, ca. 19H, PCH2, CH3CN, H2O) of
which 2.87 (CH3CNcoord,ax), 2.01 (CH3CNfree), 1.92
R%P(CHꢀCH2)2+2PHR2ꢁKꢁOꢁtꢁBꢁuꢂ
or AIBN
R%Pc(CH2CH2PtR2)2
(2)
1

72
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
also show fragments which correspond to the radi-
+
’
cal cations [RuCl{phetpX−H}]
, albeit with
No.
R%
R
pp2
much lower abundances;
4. the spectral properties of the cations remain un-
changed when the chloride counterions are replaced
by weakly coordinating anions such as CF3SO3−;
5. their 31P NMR spectra, recorded in CDCl3, exhibit
two sets of signals, one characterized by an A2X
pattern and the other corresponding to an AMX
spin system, with values of the homonuclear cou-
pling constants indicating facial coordination of the
phetpX ligands; as established for the parent cation
2a, the A2X-sets are due to the eclipsed forms 2ec of
the dinuclear cations, whereas the AMX-sets are
due to the corresponding staggered isomers 2st
where the two terminal phosphorus atoms are chem-
ically and magnetically inequivalent.
1b
1c
1d
1e
1f
Ph
Ph
Ph
p-FC6H4
p-MeC6H4
p-MeOC6H4
Ph
phetpf
phetpme
phetpome
mesetph
mesetpf
2,4,6-Me3C6H3
2,4,6-Me3C6H3
p-FC6H4
The catalysts used for the condensation reactions
were KOtBu [11,31–35,48,49] and AIBN [50–57]. The
base-catalyzed reactions give higher yields of the phos-
phines when R%=Ph (1b–d). However, it is necessary
to a use a stoichiometric amount of base to obtain 1d in
high yield. The radical-initiated reactions give cleaner
products and higher yields when R%=mesityl (1e, f).
Only the best synthetic procedures are described here;
the other experiments are reported elsewhere [23].
3.2.2. Compounds with the mesetpX ligands
Also the phosphines with the sterically demanding
mesityl group on the central phosphorus atoms,
mesetph (1e) and mesetpf (1f), react with cis-
[RuCl2(DMSO)4] giving complexes of composition
‘RuCl2(mesetph)’ and ‘RuCl2(mesetpf)’, respectively,
which were characterized by spectral and other mea-
surements. Thus, their solutions show:
3.2. Ruthenium(II)-chloro-complexes
The above ligands react with cis-[RuCl2(DMSO)4]
giving mixtures of products of composition ‘RuCl2
(pp2)’. However, their structures depend on whether the
substituent on the central phosphorus atom, Pc, of the
phosphine is a phenyl- or a mesityl-group. Therefore,
the reactions with each set of ligands will be discussed
separately.
1. molar conductances, in MeNO2, which are lower of
those
found
for
the
complexes
[Ru2(m-
Cl)3(phetph)2]X (X=Cl, CF3SO3, and [BPh4])
([2a]X) [24];
3.2.1. Compounds of the phetpX-type ligands
2. FAB mass spectra characterized by the ions
assignable to the dinuclear species ([2e]+ and [2f]+,
respectively); however, the strongest fragments are
observed at m/z=677.1 in ‘RuCl2(mesetph)’ and at
749.0 in ‘RuCl2(mesetpf)’ and correspond to the
As
found
for
the
parent
compound
PhP(CH2CH2PPh2)2 phetph, (1a) [22] the ligands with a
phenyl substituent on Pc, phetpX, (1b–d) give equi-
librium mixtures of the chloride salts of the correspond-
ing isomeric, ec-, and st-forms of the dinuclear
trichloro-bridged cations [Ru2(m-Cl)3(phetpX)]Cl ([2b–
d]Cl, respectively) as shown in Eq. (3).
+
’
radical cations [Ru(mesetph−H)]
and [Ru(me-
setpf−H)] +, respectively, rather than to the normal
cations [RuCl(mesetph)]+ and [RuCl(mesetpf)]+, as
found for the complexes containing the phetpX
ligands;
’
4PhP(CH2CH2PR2)2+4cis-[RuCl2(DMSO)2]
3. two sets of signals in their 31P NMR spectra, in
CDCl3, one characterized by an ABX- and in the
other by an A2X-spin system; while the signals of
the ABX-set are in the region which is characteristic
for the 2st isomers, the X chemical shifts in the
spectrum of the compound with the A2X-pattern are
found at much higher frequencies than those usually
observed for the analogous P atoms in the eclipsed
isomers of 2ec;
“16DMSO+ec-[Ru2(m-Cl)3(phetpX)2]Cl
[2ec]Cl
+st-[Ru2(m-Cl)3(phetpX)2]Cl
[2st]Cl
(3)
where R=p-F-C6H4, p-Me-C6H4, p-MeO-C6H4.
The products were characterized by conductivity
measurements and by IR, FAB-MS, H and 31P NMR
1
spectroscopy. Thus,
1. they behave as 1:1 electrolytes in MeNO2 solution;
2. their IR spectra show absorptions in the range of
240–260 cm−1, a region characteristic for w(Ru–
Cl–Ru) vibrations;
4. the complete disappearance of the resonances of
the A2X-set upon addition of one equivalent
AgCF3SO3 to a solution containing two equivalents
of ‘RuCl2(mesetpX)’ while the remaining ABX-type
signals are identical with those present in the origi-
nal solution.
3. their FAB mass spectra show ions at masses cor-
responding
to
dinuclear
cations
[Ru2(m-
Cl)3(phetpX)2]+ and base peaks due to the corre-
sponding uninuclear units [RuCl(phetpX)]+; they
5. slow equilibria between the corresponding pairs of
complexes in solution.

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
73
These results are consistent with the presence of a
mixture of the dinuclear cationic complex st-[Ru2(m-
Cl)3(mesetpX)2]+ (X=H (2est) and X=F (2fst)) and
an uncharged species which could be either uninuclear
[RuCl2(mesetpX)] (X=H (3e) and X=F (3f)), or dinu-
As the molar volumes of the uninuclear compounds (3)
are smaller than those of the binuclear species (4), it
appeared likely that the nuclearity of the uncharged
species could be calculated by determining their hydro-
dynamic radii using diffusion coefficients. Additional
information was also sought by obtaining the equilib-
rium constant between 2e and 3e (or 4e) and by studying
the temperature-dependence of this equilibrium.
clear [Ru2Cl2(m-Cl)2(mesetpX)2] (X=H (e.g. 4efac,trans
)
and X=F, (e.g. 4ffac,trans)).
3.2.2.1. Diffusion coefficients. 1H NMR-monitored
pulsed field gradient spin-echo methods [42,43] were
employed to simultaneously determine the diffusion
coefficients of the two species under equilibrium condi-
tions. This is possible as the two components are easily
1
distinguished by their H and 31P NMR spectra (see
Fig. 1) because of the rather slow interchange rates on
their respective NMR time-scales. The results of this
experiment, carried out on solutions containing [2e]Cl
and 3e, are shown in Fig. 2. The non-linear fit to the
equation given in Fig. 2, using the self-diffusion coeffi-
cient of CHCl3 as a reference, gives the values
8.66(9)×10−10 m2 s−1 and 7.07(7)×10−10 m2 s−1 for
the two species. The former value is assigned to uni-
and the latter to the dinuclear component.
The reliability of these assignments depends on the
significance of the difference between the two values.
Consequently, checks were made using a simple model
calculation based on the assumptions that these species
have spherical shapes and the volume of dinuclear
species (2e) is twice that of uninuclear compound (3e).
The latter assumption is supported by the molar vol-
Fig. 1. NMR spectroscopic study of the equilibrium [Ru2(m-Cl)3
(mesetph)2]Cl, [2e]Cl X 2[RuCl2(mesetp)] (3e); (a) contour plot of
part of the two-dimensional 31P–1H correlation showing the assign-
ment of the 1H NMR resonances (b) due to the mesityl CH3-groups.
umes of ec-[Ru2(m-Cl)3(phetph)2]CF3SO3 (2a) and
3
,
fac-[RuCl2(ttp)] which are 1781 and 820 A , respec-
tively [22]. One can then use the Stokes–Einstein
relation D=kBT/6ypr (D=diffusion coefficient, kB=
Boltzmann’s constant; T=absolute temperature; p=
viscosity of the solution; and r=radius of the sphere).
On this basis, the ratio of the two diffusion coefficients
should be the cube root of 2 (ca. 1.26) in excellent
agreement with the ratio (1.23(3)) of the experimental
values. Furthermore, calculations assuming that the
uninuclear complex is of spherical shape and the dinu-
clear species has an elongated shape, the longer axis
being twice that of the smaller, gives a ratio of the
diffusion coefficients of ca. 1.18 [58]. Thus, the differ-
ence observed in the diffusion coefficients is significant
and consistent with the simultaneous presence of uninu-
clear [RuCl2(mesetph)] (3e) and dinuclear st-[Ru2(m-Cl)3
(mesetph)2]Cl ([2e]Cl) as shown in Eq. (4).
Fig. 2. Plot of the relative signal intensities I/I0 of the CH3-group
resonances in [2e]Cl (squares) and 3e (circles) vs. the strength of the
applied pulsed field gradients (in arbitrary units). The experimental
data were fitted (solid lines) to the equation given in the Figure,
(k=magnetogyric ratio of 1H, D=diffusion coefficient, D=time
separation of the two pulsed field gradients of strength g (varied) and
duration l in the Stejskal–Tanner experiment [43] (D=7.07(7)×
10−10 and 8.66(9)×10−10 m2 s−1 for [2e]Cl and 3e, respectively).
(4)

74
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
concentration of {RuCl2(mesetph)}2 were made by
monitoring the 1H NMR integrals of both types of
methyl groups of the mesityl substituents whereby an
increase in the mole fraction of the cationic species
[Ru(m-Cl)3(mesetph)2]+ was clearly noted. As:
1. the equilibrium of Eq. (5) cannot be detected in the
present case (one does not expect a significant differ-
ence between the signals of {[2e]Cl} and of 2e);
2. changes in total concentration of the species of
composition ‘RuCl2(mesetph)’ should not lead to
changes in the relative concentrations of the two
species in the equilibria expressed by Eqs. (6) and (9);
the above equilibria cannot be responsible for the ob-
served behavior.
However, the equilibria in Eqs. (7) and (8), would
lead to changes in the species distribution with the total
ruthenium concentration. As, in the former equilibrium,
an increase in [Ru]tot should cause a decrease of the
mole fractions of the bimetallic complexes [Ru2(m-
Cl)3(mesetph)2]+ (2e) and/or [Ru2(m-Cl)3(mesetph)2]Cl
({[2e]Cl}), contrary to what is observed, these studies
show that Eq. (8) must be operative in agreement with
the diffusion experiments described above.
Fig. 3. Plot of the total complex concentration (C) vs. the dissociation
degree h (squares), showing the concentration dependence of the
equilibrium [Ru2(m-Cl)3(mesetph)2]Cl ([2e]Cl) X 2 [RuCl2(mesetp)]
(3e). The experimental data were fitted (solid line) to Ostwald’s
relation C=K(1−h)/h2 giving K=1.8×10−2 mol l−1
.
3.2.2.2. Equilibria. The most likely equilibria in solution
between the two components st-[Ru2(m-Cl)3(mes-
etph)2]Cl ([2e]Cl) and [RuCl2(mesetph)] (3e) are given in
Eqs. (5)–(9), if one assumes that both the ion-pair
({[2e]Cl}) and the ionized species (2e and Cl−) are
present is solution, an assumption supported by the
high molecular weight of [2e]Cl found osmometrically
in CH2Cl2 [24].
To further substantiate this conclusion, the experi-
mental data were checked using Ostwald’s relationship
for dissociation processes. The results, presented in Fig.
3, are in agreement with the process shown in Eq. (8)
with the equilibrium constant K=1.8×10−2 mol l−1
.
3.2.2.3. Temperature dependence of the equilibrium.
Changes in the position of the equilibrium in Eq. (8), as
a function of temperature, was monitored by recording
the 31P NMR spectrum of a CDCl3 solution of
‘RuCl2(mesetph)’ between 296 and 338 K. One obtains
linear plot of ln K versus T−1 showing that the dissoci-
ation of {[Ru2(m-Cl)3(mesetph)2]Cl} ([2e]Cl) into uninu-
clear [RuCl2(mesetph)] (3e) is endothermic (DH=32 kJ
{[Ru2(m-Cl)3(mesetph)2]Cl}
{[2e]Cl}
X [Ru2(m-Cl)3(mesetph)2]+ +Cl−
2e
{[Ru2(m-Cl)3(mesetph)2]Cl}
{[2e]Cl}
(5)
(6)
(7)
X [Ru2Cl2(m-Cl)2(mesetph)2]
4e
mol−1) and favored by the entropy (DS=75 J mol−1
)
[Ru2(m-Cl)3(mesetph)2]+ +Cl−
as expected for Eq. (8).
2e
Summing up, the ruthenium(II)-chloro complexes
with the terdentate phosphines with phenyl groups on
the central P-atoms, Pc (1a–1d) exist in solution exclu-
sively as mixtures of the two ec- and st-isomeric forms
X [Ru2Cl2(m-Cl)2(mesetph)2]
4e
{[Ru2(m-Cl)3(mesetph)2]Cl}
{[2e]Cl}
of
the
dinuclear
trichloro-bridged
[Ru(m-Cl)3
(phetpX)2]Cl ([2aec–2dec]Cl and ([2ast-2dst]Cl, respec-
tively). However, phosphines 1e–1f, i.e. those where the
central phosphorus donors carry a mesityl substituent,
give only one of the isomeric forms of the trichloro-
bridged dinuclear cationic complexes, i.e. st-[Ru(m-
Cl)3(mesetpX)2]Cl (X=H (2est), and X=F (2fst)).
These dinuclear complexes are in dynamic equilibrium
with the corresponding uncharged uninuclear species
[RuCl2(mesetpX)] (X=H (3e) and X=F (3f)).
As it was expected that complexes of the types 2 and
3 would show different reactivities, (a) solutions con-
taining mixtures of 2st and 3 and (b) solutions contain-
ing only 2ec and 2st, were reacted with carbon monoxide.
X 2[RuCl2(mesetph)]
(8)
(9)
3e
[Ru2(m-Cl)3(mesetph)2]+ +Cl−
2e
X 2[RuCl2(mesetph)]
3e
where K5=[B5]2/[A5], K6=[B6]/[A6], K7=[B7]/[A7]2,
K8=[B8]2/[A8], K9=[B9]2/[A9]2 and [An] and [Bn] are
the relative concentrations of the particles on the left
and right hand side of each equation, respectively.
Measurements of the relative concentrations of 2e
and 3e in CDCl3, as functions of an increasing total

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
75
3.3. Reaction of CO with a solution containing
st-[Ru2(v-Cl)3(mesetpX)2]Cl ([2st]Cl) and
[RuCl2(mesetpX)] (3)
a 1:1 electrolyte. Furthermore, the spectral data charac-
terizing 5e are:
1. its IR spectrum shows one strong absorption, at
2010 cm−1, consistent with the presence of a mono-
carbonyl species;
When CO is bubbled through a CH2Cl2 solution
containing the equilibrium mixture of st-[Ru2(m-Cl)3
(mesetph)2]Cl ([2e]Cl) and [RuCl2(mesetph)] (3e), two
carbonyl complexes, in the approximate ratio of 9:1,
are formed.
2. its 31P NMR spectrum is characterized by an AMX
2
spin system and the magnitudes of J(31P,31P) indi-
cate facial coordination of the mesetph ligand, while
the non-equivalence of the terminal phosphorus
donors suggest that one of these is located in trans-
position to CO;
3. its 13C NMR spectrum is characterized by a large
trans-coupling (2J(31P,13C)=114.1 Hz) for the CO
resonance supporting the above assignment;
4. two-dimensional spectroscopic studies (see Fig. 4)
show that the 31P resonance at l 50.3 can unam-
biguously be assigned to the donor atom in trans-
position to Cl and the other, at l 38.9, to that in
trans-position to CO.
The major component is fac-[RuCl2(CO)(mesetph)]
(5e). Thus: the apparent molar conductivity of the
mixture, in MeNO2, is somewhat higher than that of an
uncharged complex but significantly lower than that of
The minor component of the mixture (6e), i.e. that
characterized by an A2X pattern in its 31P NMR spec-
trum, becomes the main product when the carbonyla-
Fig. 4. Two-dimensional NMR spectroscopy for [RuCl2(CO)(mesetph)] showing the assignment of the 31P spins: (a) conventional heteronuclear
31P–1H correlation spectrum and (b) part of the 31P relayed 13C–1H correlation experiment. The first experiment, a two-dimensional 31P–1H
correlation experiment, relates the phosphorus spins to the respective phenyl and backbone protons; in particular, one finds a large (ca. 45–50
3
Hz) vicinal coupling J(P,H) to one of the backbone protons. The second experiment is a special version of a 13C–1H correlation relayed through
31P where magnetization is transferred from the 31P spins to the carbonyl carbon, back to the phosphorus and the response is then detected in
the 1H domain. The transfer processes are optimized for the large couplings 2J(P,CO) ca. 114 Hz and 3J(P,H) ca. 50 Hz making the path shown
in the structural formula exclusive and, therefore, allowing the assignment of the respective P donors.

76
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
tion reaction is carried out in the solvent mixture
CH2Cl2/MeOH. It is assigned structure cis, fac-[Ru-
Cl(CO)2(mesetph)]Cl ([6e]Cl) on the basis of:
These data do not allow the unambiguous assign-
ment of the relative positions of the phenyl substituent
on Pc and CO, i.e. whether they are transoid, as shown
1
1. two strong IR absorptions at 2064 and 2015 cm−1
;
in structure 7 above, or cisoid. The H chemical shift
2. a molar conductance, in MeNO2, consistent with the
presence of a 1:1 electrolyte;
characteristics of the ortho-phenyl protons favor the
former structure, although this assignment has to be
considered as tentative.
It is likely that 7a was previously obtained by Taqui
Kahn and Mohiuddin from the direct reaction of
RuCl3 · xH2O with phetph in refluxing DMF [59]. Al-
though no 31P or 13C NMR data supporting this formu-
lation were given, the w(CO) vibration reported (1960
cm−1) is in agreement with the value found in this
study.
Summing up: the reaction of CO to complexes of
composition ‘RuCl2(pp2)’ gives mixtures of fac-
[RuCl2(CO)(pp2)] and fac-[RuCl(CO)2(pp2)]Cl as kinetic
products; these subsequently convert to the thermody-
namically stable complexes mer-[RuCl2(CO)(pp2)].
3. a 31P NMR spectrum which exhibits equivalent
terminal phosphorus donors, Pt;
4. a 13C NMR spectrum showing the presence of
equivalent CO ligands with large 2J(P,C) trans
couplings.
Similarly, the reaction of CO with a mixture of
[Ru2(m-Cl)3(mesetpf)2]Cl ([2f]Cl), and [RuCl2(mesetpf)]
(3f), in CH2Cl2, gave fac-[RuCl2(CO)(mesetpf)] (5f),
and fac-[RuCl(CO)2(mesetpf)]Cl (6f), in the ratio of ca.
95:5, respectively.
As the mesityl-substituted ligands give equilibrium
mixtures of dinuclear (2) and uninuclear (3) complexes,
it is possible that the chloro-bridges in these com-
pounds are weak. Thus, it is likely that CO reacts
preferentially with the uninuclear, coordinatively unsat-
urated species 3. However, this reaction goes to comple-
tion as 2 and 3 are in equilibrium.
3.5. Cationic acetonitrile-containing complexes
As described in an earlier publication [24], [Ru2(m-
Cl)3(phetph)2]Cl ([2a]Cl) reacts with 4 equivalents of
AgCF3SO3, in MeCN, giving the cationic complex fac-
[Ru(MeCN)3(phetph)](CF3SO3)2 ([8a](CF3SO3)2) (see
Eq. (10)). This salt loses one molecule of MeCN rela-
tively easily with formation of [Ru(CF3SO3)(MeCN)2
(phetph)](CF3SO3) [24] as shown in Eq. (11).
3.4. Reaction of CO with a solution containing
st-[Ru2(v-Cl)3(phetpX)2]Cl ([2st]Cl), and
ec-[Ru2(v-Cl)3(phetpX)2]Cl ([2ec]Cl)
The isomeric mixture of ec- and st-[Ru2(m-Cl)3
(phetph)]+ [22] does not readily react with CO, in
CH2Cl2. As in this system the equilibrium (Eq. (8)) is
completely shifted towards the dinuclear trichloro-
bridged cations, this behavior supports the hypothesis
that in complexes of the type ‘RuCl2(mesetph)’, CO
reacts preferentially with the mononuclear compounds.
However, when [Ru2(m-Cl)3(phetph)2]Cl ([2a]Cl), in
CH2Cl2, is reacted with CO at high pressure (100 bar) a
1:1 mixture of fac-[RuCl2(CO)(phetph)] (5a) and fac-
[RuCl(CO)2(phetph)]Cl (6a) is formed. A 31P NMR
spectrum shows that this solution also contains a minor
component (7a). This complex is the sole product when
(a) the reaction with CO is carried out in the solvent
mixture CH2Cl2/MeOH (1:1) at atmospheric pressure
or (b) the mixture of 5a and 6a is allowed to isomerize
in this solvent mixture (the latter reaction occurring
with loss of CO).
[Ru2(m-Cl)3(phetph)2]Cl+4AgCF3SO3+6MeCN
“2[Ru2(MeCN)3(phetph)2]2+ +4AgCl+4CF3SO3−
8
(10)
(11)
Complex 7a is assigned the structure cis,mer-
[RuCl2(CO)(phetph)] on the basis of the following
observations:
1. it is a non-electrolyte in MeNO2;
2. its IR spectrum exhibits a single carbonyl stretch at
The ligands 1b–d show analogous behavior. The
complexes fac–[Ru(MeCN)3(phetpX)](CF3SO3)2 (8b–d)
and fac-[Ru(CF3SO3)(MeCN)3(phetpX)](CF3SO3) (9b–
d) were characterized by standard measurements (see
Experimental Section) and used for the acetalization
reactions described below.
1969 cm−1
;
3. its 31P NMR spectrum shows equivalent terminal
phosphorus donors;
4. its 13C NMR spectrum exhibits three small cou-
plings between CO and the P donors.

Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
77
(13)
The relative activities of [Ru(MeCN)3(triphos)]-
(CF3SO3)2 (9), [Ru(MeCN)3(ttp)](CF3SO3)2 (10) and
[Ru(MeCN)3(phetph)](CF3SO3)2 (8a) in the reaction
shown in Eq. (11) are shown in Fig. 5. As can be seen
there, all of them have comparable activities although 9
is slightly more active than 10 which, in turn, is more
active than 8a. This difference in reactivity is more
marked in the trans-acetalization reaction (Eq. (12)) as
shown in Fig. 6.
As structural studies indicate that the cavity defined
by the fragment {(ttp)M}z+ is larger than that avail-
able in {(phetph)M}z+ [24], complexes of the former
type tend to be five-coordinate, i.e. coordinatively un-
saturated and, therefore, more reactive than those con-
taining phetph.
The effect of changing the substituents in p-positions
on the terminal phenyl substituents is small as indicated
by the data summarized in Fig. 7. However, complex
8b, which contains the F-substituted ligand 1b, gives a
slightly faster reaction rate than complex 8a with the
unsubstituted ligand 1a. On the other hand, complexes
8c and 8d, which contain ligands with electron-donating
substituents 1c and 1d, respectively, give slower reac-
tion rates, as expected.
Scheme 1.
3.6. Acetalization experiments
As reported in earlier publications, the cationic com-
plex [Rh(MeCN)3(triphos)](CF3SO3)3 is a very efficient
catalyst for acetalization and trans-acetalization reac-
tions [21]. Also [Ru(MeCN)3(triphos)](CF3SO3)2 is a
catalyst for these reactions [23] as well as the tetrahy-
dropyranylation of alcohols and phenols [60] and the
formation of 1,3-dioxanylphenols or 1,3-dioxanolylphe-
nols [61]. It has been postulated [21] that the high
activity of these species in an acetalization reaction is
due to their ability to simultaneously coordinate the
carbonyl compound and the alcohol to the active sites
in {(triphos)M}z+ (see Scheme 1). Thus, studies were
carried out to test whether (a) the catalytic activities of
complexes of the type [Ru(MeCN)3(phetpX)](CF3SO3)2
and of [Ru(MeCN)3(ttp)](CF3SO3)2 were comparable
with that of [Ru(MeCN)3(triphos)](CF3SO3)2 and (b)
complexes of the above type with ligands 1a–d, i.e.
with different substituents on the p-positions of the
terminal phenyl substituents of the Pt-atoms, show dif-
ferent reactivities.
The acetalization and trans-acetalization reactions
used in this study are shown in Eqs. (12) and (13),
respectively.
Fig. 5. The time-dependence of the acetalization reaction of cyclo-
hexanone (1 equiv.) and 1,2-ethanediol (1.2 equiv.) (Eq. (7)) using
HC(OiPr)3 (1.1. equiv.) as a drying agent, in CH2Cl2 at 30°C and
[Ru(MeCN)3(tp)](CF3SO3)2 as catalyst (catalyst/substrate ratio 1/
2000). Curve 1: tp=triphos; curve 2: tp=ttp; Curve 3: tp=phetph.
(12)

78
Q. Jiang et al. / Inorganica Chimica Acta 290 (1999) 64–79
are observed when aryl-substituted complexes of
It can then be concluded that changing the aryl
triphos-type ligands are used, as here six substituents
are present. Thus, rhodium complexes of the ligand
CH3C(CH2PR2)3 (R=m-CF3–C6H4) [62] catalyze even
the acetalization of diarylketones [63].
substituents on the terminal phosphorus atoms can
modify the catalytic activities of cationic complexes.
However, when these changes are made in ligands of
pp2-type the effects are small, presumably because only
four substituents are introduced. Much larger effects
Acknowledgements
Q.J. carried out the work during the tenure of a grant
from the Swiss National Science Foundation.
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