Syntheses and characterization of a series of carbonylruthenium(I) and (II) complexes containing pyridyl ligands

Article abstract of DOI:10.1016/S0022-328X(99)00222-3

The reaction of dodecacarbonyltriruthenium (Ru₃(CO)₁₂) with tris(2-pyridylmethyl)ammonium perchlorate (tpa·3HClO₄) in toluene, in the presence of acetic acid, produced a new ruthenium(II) complex of tpa [Ru(CH₃CO₂)(CO)(tpa)]ClO₄·C ₆H₅CH₃ (1). A similar reaction of Ru₃(CO)₁₂ with 2-pyridylcarboxylic acid (pyCO₂H) in toluene yielded a ruthenium(II) complex Ru(pyCO₂)₂(CO)₂ (2). A related ruthenium(III) compound, [Ru(pyCO₂)₃]·H₂O (3), was obtained from the reaction of RuCl₃·nH₂O and sodium 2-pyridinecarboxylate in a mixture of water and ethanol (1:1 by volume). The reaction of Ru₃(CO)₁₂, benzoic acid and pyridine (py) in toluene resulted in the formation of a dinuclear ruthenium(I) complex [Ru₂(C₆H₅CO₂)₂(CO) ₄(py)₂]·0.5C₆H₅CH₃ (4). Compounds 1-4 have been characterized by IR, NMR and X-ray crystallography.

Full text of DOI:10.1016/S0022-328X(99)00222-3

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 585 (1999) 246–252
Syntheses and characterization of a series of carbonylruthenium(I)
and (II) complexes containing pyridyl ligands
Li Xu, Yoichi Sasaki *
Di6ision of Chemistry, Graduate School of Science, Hokkaido Uni6ersity, Kita-ku, Sapporo 060-0810, Japan
Received 19 December 1998; received in revised form 14 April 1999
Abstract
The reaction of dodecacarbonyltriruthenium (Ru3(CO)12) with tris(2-pyridylmethyl)ammonium perchlorate (tpa·3HClO4) in
toluene, in the presence of acetic acid, produced a new ruthenium(II) complex of tpa [Ru(CH3CO2)(CO)(tpa)]ClO4·C6H5CH3 (1).
A similar reaction of Ru3(CO)12 with 2-pyridylcarboxylic acid (pyCO2H) in toluene yielded a ruthenium(II) complex
Ru(pyCO2)2(CO)2 (2). A related ruthenium(III) compound, [Ru(pyCO2)3]·H2O (3), was obtained from the reaction of
RuCl3·nH2O and sodium 2-pyridinecarboxylate in a mixture of water and ethanol (1:1 by volume). The reaction of Ru3(CO)12,
benzoic acid and pyridine (py) in toluene resulted in the formation of
a
dinuclear ruthenium(I) complex
[Ru2(C6H5CO2)2(CO)4(py)2]·0.5C6H5CH3 (4). Compounds 1–4 have been characterized by IR, NMR and X-ray crystallography.
© 1999 Elsevier Science S.A. All rights reserved.
Keywords: Ruthenium complexes; Pyridyl complexes; Carboxylate complexes; Carbonyl complexes
The direct reactions of Ru3(CO)12 with pyridine and
polydentate nitrogen-containing ligands in the presence
1. Introduction
of carboxylic acid, which could provide a convenient
route to the above pyridyl carbonyl carboxylate com-
It has been known that the reactions of dodecacar-
bonyltriruthenium Ru3(CO)12, with carboxylic acids
RCO2H, produce polymeric compounds [Ru2-
(RCO2)2(CO)4]n, which undergo depolymerization when
reacting with monodentate ligands L such as tertiary
phosphines to give dimers Ru2(RCO2)2(CO)4L2 [1–3].
When a didentate nitrogen-containing ligand (L%) like
2,2%-bipyridine (bpy) is reacted, the formation of
mononuclear ruthenium(II) carbonyl complexes
Ru(RCO2)2(CO)2L% with cis(CO)-trans(RCO2) configu-
ration, was claimed on the basis of spectroscopic data
[4]. The mononuclear complexes were previously pre-
pared from the reaction of RuCl2(CO)2L% with silver
carboxylates [5]. Similarly, Ru(CH3CO2)2(CO)2(py)2
was prepared from RuCl2(CO)2(py)2 whose geometric
configuration was suggested to be trans(Cl)-cis(CO)-
cis(py). The geometrical structure of Ru(CH3CO2)2-
(CO)2(py)2, i.e. cis or trans with respect to the pyridine
ligands, could not be determined from the spectroscopic
properties [5].
* Corresponding author. Fax: +81-11-7063447.
Scheme 1. Schematic view of syntheses of compounds 1–4.
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00222-3

L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
247
plexes of ruthenium, have not been investigated in
detail. This work deals with the reactions of dodecacar-
bonyltriruthenium with tris(2-pyridylmethyl)ammon-
ium perchlorate (tpa·3HClO4) in the presence of acetic
acid and with 2-pyridinecarboxylic acid (pyCO2H).
Two new mononuclear ruthenium(II) carbonyl com-
plexes [Ru(CH3CO2)(CO)(tpa)]ClO4·C6H5CH3 (1) and
Ru(pyCO2)2(CO)2 (2), respectively, were obtained.
Compound 1, which has appeared as a preliminary
communication [6], represents the first example of
ruthenium carbonyl complexes of tpa, although several
ruthenium [7–11] and metal carbonyl complexes [12]
containing tpa have been reported. The tris(pyridine-
carboxylato)ruthenium(III) complex [Ru(pyCO2)3]·H2O
(3) was not obtained from the latter reaction, but was
assessable by a quite different method. Preparation and
structural studies of the dimeric pyridine derivative
[Ru2(C6H5CO2)2(CO)4(py)2]·0.5C6H5CH3 (4), will also
be presented in view of the absence of its structural
data in the literature.
However, it can be easily prepared from the reaction of
RuCl3·nH2O and sodium 2-pyridinecarboxylate in a 1:1
mixture of water and ethanol.
When a tripodal tetradentate ligand tpa was em-
ployed in the presence of acetic acid, the reaction of
Ru3(CO)12 afforded the ruthenium(II) monocarbonyl
complex [Ru(CH3CO2)(CO)(tpa)]ClO4·C6H5CH3 (1). A
related compound [Ru(HCO2)(CO)(bpy)2]+, was previ-
ously prepared from the reaction of Ru(CO3)(bpy)2
with formic acid [13]. The synthesis of compound 1
from the reaction of the polymeric species
[Ru2(CH3CO2)2(CO)4]n and tpa was unsuccessful, sug-
gesting that the polymer may not be an intermediate in
the formation of 1. It should be noted that a similar
reaction of the polymeric species with 2,2%-bipyridine
(bpy) or 1,10-phenanthroline (phen) was reported to
yield the mononuclear ruthenium(II) carbonyl com-
plexes [Ru(CH3CO2)2(CO)2L] (L=bpy or phen) on the
basis of spectroscopic data [2].
2.2. Structures and IR spectra
2. Results and discussion
Compounds 1–4 have been characterized by X-ray
crystallography. Selected bond lengths and angles are
listed in Table 1. Fig. 1 shows the structure of the
complex cation [Ru(CH3CO2)(CO)(tpa)]+. The cation
contains an octahedrally coordinated Ru(II) ion with
two axial sites occupied by the pyridine rings (N2 and
N3) and four equatorial sites occupied by the tertiary
amine nitrogen (N1), the other pyridyl nitrogen (N4), a
carbonyl and an acetate oxygen. The structure has ideal
mirror symmetry with the mirror plane defined by the
RuNlCl6Cl7N4 five-membered ring. The acetate group
deviates slightly from the plane. The Cs symmetry is
2.1. Synthesis
Syntheses of compounds 1–4 are shown in Scheme 1.
The pyridine complex of carbonyl ruthenium(I)
Ru2(C6H5CO2)2(CO)4(py)2 (4), was obtained by reflux-
ing a mixture of Ru3(CO)12, benzoic acid and pyridine
in toluene under argon atmosphere. The red–brown
solution became yellow in color after several minutes,
indicative of the rapid oxidation of the Ru(0) carbonyl
by the acid. Evaporation of the resulting yellow solu-
tion in an open beaker led to the formation of the
yellow crystals of [Ru2(C6H5CO2)2(CO)4(py)2]·0.5C6-
H5CH3 (4) in about an 80% yield. Such dimeric
pyridine derivatives were previously prepared from the
reaction of Ru2(C6H5CO2)2(CO)6 or [Ru2(CH3CO2)2-
(CO)4]n with pyridine [1,3]. In the absence of pyridine,
the reaction was reported to lead to the slow formation
of the insoluble polymeric species [Ru(C6H5CO2)2(CO)4]n
[3].
The orange precipitate formed within several minutes
when 2-pyridinecarboxylic acid (pyCO2H) was used
instead of benzoic acid. X-ray structure determination
of the orange solid, to be described later, unambigu-
ously show that it is a mononuclear ruthenium(II)
carbonyl complex Ru(pyCO2)2(CO)2 (2) rather than the
polymeric species [Ru2(pyCO2)2(CO)4]n. The reaction
runs almost quantitatively. Further, the oxidized
derivative Ru(pyCO2)3 (3), was not formed even if an
excess of 2-pyridinecarboxylic acid and prolonged
reflux times were employed. Neither can compound 3
be obtained from further substitution of the carbonyl
groups by reacting 2 with 2-pyridinecarboxylic acid.
1
retained in solution as indicated by the H-NMR spec-
trum to be described below. The carbonyl group occu-
pies the site trans to the N1 (tertiary amine) atom
(N1–Ru–C1, 177.0(4)°). This may be a consequence of
strong Ru(II)“CO back donation as indicated by the
,
unusually short Ru–C bond (1.81(1) A) and low CO
stretching frequency (1938 cm−1), which prefers s or
weak p donor groups occupying the site opposite to CO
to favor the d–p* back donation. The Ru–C(CO) bond
length
[Ru3O(CH3CO2)6(CO)(mbpy+)2]2+
methyl-4,4%-bipyridinium ion) (1.84(2) A) [14] and in
is
slightly
shorter
than
that
in
(mbpy+ =N-
,
[Ru(COOH)(CO)(bpy)2]+ (1.845(6) A) [15]. On the
,
,
contrary, the C–O bond (1.17(1) A) of the former is
longer than those of the latter two (1.13(3) and 1.127(6)
,
A, respectively). The CO stretching frequency in 1 is
slightly lower than those in the Ru3 compound (1940
cm−1) and in the bpy species (1958 cm−1), consistent
with their structural data.
The acetate group is cis to the tertiary amine nitrogen
,
with the Ru–O distance of 2.086(8) A, close to those in

248
L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
Table 1
,
Selected bond lengths (A) and angles (°) for compounds 1–4
1
2
3
4
,
Bond lengths (A)
Ru1–Ru2
Ru1–C1
Ru1–C2
Ru2–C3
Ru2–C4
Ru1–O5
Ru1–O7
Ru2–O6
Ru2–O8
Ru1–N1
Ru2–N2
2.6809(7)
1.819(5)
1.823(5)
1.808(5)
1.819(5)
2.119(3)
2.121(3)
2.118(5)
2.127(3)
2.216(4)
2.240(3)
Ru–C1
1.81(1)
Ru–C1
Ru–C2
1.852(7)
l.893(7)
Ru–O2
2.086(8)
Ru–O3
Ru–O5
2.071(4)
2.065(4)
Ru–O1
Ru–O3
Ru–O5
2.013(5)
2.004(4)
1.998(5)
Ru–N1
Ru–N2
Ru–N3
Ru–N4
C1–O1
2.132(8)
2.08(1)
2.062(9)
2.064(9)
1.17(1)
Ru–N1
Ru–N2
2.053(5)
2.073(5)
Ru–N1
Ru–N2
Ru–N3
2.071(5)
2.046(5)
2.038(5)
C1–O1
C2–O2
1.142(9)
1.127(9)
C1–O1
C1–O2
C1–O3
C1–O4
1.150(5)
1.143(5)
1.163(5)
1.152(5)
Bond angles (°)
N2–Ru–N3
162.5(4)
N1–Ru–N2
163.1(2)
N2–Ru–N3
171.1(2)
N1–Ru1–Ru2
N2–Ru2–Ru1
C1–Ru1–O5
C1–Ru1–O7
C1–Ru1–C2
C1–Ru1–O5
C1–Ru1–O7
O5–Ru1–O7
Ru1–C1–O1
Ru1–C2–O2
Ru2–C3–O3
Ru2–C4–O4
160.07(9)
162.36(8)
93.5(2)
178.9(2)
88.0(2)
177.8(2)
92.6(2)
85.8(1)
179.4(4)
179.5(5)
178.5(4)
176.7(5)
C1–Ru–O2
C1–Ru–N1
C1–Ru–N4
O2–Ru–N4
O2–Ru–N1
N1–Ru–N4
Ru–C1–O1
96.7(4)
177.0(4)
94.4(4)
168.6(3)
86.2(3)
82.7(3)
176(1)
C1–Ru–C2
C1–Ru–O3
C1–Ru–O5
C2–Ru–O5
C2–Ru–O3
C3–Ru–O5
Ru–C1–O1
Ru–C2–O2
89.3(3)
177.3(2)
94.3(3)
175.8(2)
92.1(2)
84.3(2)
178.7(6)
176.0(6)
O1–Ru–O3
O1–Ru–O5
O1–Ru–N1
O3–Ru–N1
O3–Ru–O5
O5–Ru–N1
90.3(2)
175.8(2)
78.8(2)
169.2(2)
93.8(2)
97.0(2)
[Ru3O(CH3CO2)6(mbpy+)2(CO)]2+ (2.07(1) A) [14]
,
compound 1. The differences in the Ru–O and Ru–N
distances in 1 and 2 are statistically insignificant. How-
and [Ru2O(CH3CO2)(tpa)2]3+ (2.085(7) A) [9]. The
,
,
ever, the Ru–C bonds in 2 (av. 1.87(2) A) are signifi-
N2–Ru–N3 angle is 162.5(4)°, indicating that the octa-
hedron is distorted. The Ru–Nl(amine) distance
(2.132(8) A) is significantly longer than the remaining
Ru–N(py) distances (2.07(1) A) probably due to both
the trans influence of CO and absence of d–pp bond. It
should be noted that the former is similar to the
cantly longer than that in 1 as a consequence of the fact
that in compound 2 the back-donating electrons of
Ru(II) are shared by the two CO groups. This observa-
tion corresponds to the higher CO stretching frequency
in 2 (2062, 1998 cm−1) which are close to those in the
related compound, Ru(CH3CO2)(CO)2(py)2 (2065, 1992
cm−1) [5].
,
,
,
Ru–N(py) distance (2.129(4) A) trans to the CO group
in [Ru(COOH)(CO)(bpy)2]+ [15].
Fig. 3 shows the structure of Ru(pyCO2)3 (3). The
structure may be conveniently understood on the
grounds that the two CO groups in 2 are further
replaced by a pyCO2 ligand. The compound thus takes
mer (cis–trans) configuration. The octahedral coordina-
tion sphere of Ru(III) distorts to a lesser extent than
that in 2 as indicated by the greater N2–Ru–N3 angle
The structure of compound Ru(pyCO2)2(CO)2 (2),
which has ideal C2 symmetry, is given in Fig. 2. The
complex takes cis configuration with respect to the two
CO ligands. Two pyridyl groups lie at the trans sites to
each other and cis to the carbonyl groups. Each car-
boxylato group is consequently trans to one of the two
carbonyls. Similar to the case in 1, such an arrangement
seemingly reveals that s donor ligands prefer to occupy
the sites trans to CO. Following this fact, the actual
structure of Ru(CH3CO2)2(CO)2(py)2 is most likely that
with trans arrangement of two pyridine ligands [5]. The
mean N–Ru–O angle in the RuNCCO five–membered
ring (79.8(8)°) is similar to the corresponding values in
(171.1(2)°), the corresponding angle in
2 being
163.1(2)°. The most notable differences in structural
parameters in 2 and 3 are the Ru–O(O2CCH3) dis-
,
,
tances, 2.068(4) A in the former and 2.005(5) A in the
latter. This may be due to both the smaller bonding
radius of Ru(III) and the absence of trans influence of

L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
249
Fig. 1. ORTEP drawing of the cation [Ru(CH3CO2)(CO)(tpa)]+ in 1
with the atomic numbering scheme. Thermal ellipsoids are drawn at
the level of 50% probability.
CO in compound 3. The Ru(III)–N bond lengths in 3
(2.05(1) A) are not significantly shorter than the Ru(II)–
Fig. 3. ORTEP drawing of Ru(pyCO2)3 (3) with the atomic numbering
scheme. Thermal ellipsoids are drawn at the level of 50% probability.
,
,
,
N(py) ones in 1 (av. 2.07(1) A) and 2 (av. 2.06(1) A) as
a result of the presence of d–pp bonds in the latter species.
The structure of Ru2(C6H5CO2)(CO)4(py)2 (4) is given
in Fig. 4. Two Ru(I) atoms are bridged by two benzoate
,
groups. The Ru–Ru distance (2.6809(7) A) is close to
,
that in the acetate analogue (2.678 A) [16], and
is consistent with the existence of the Ru(I)–Ru(I) single
bond. Octahedral coordination geometry of each
Fig. 2. ORTEP drawing of Ru(pyCO2)2(CO)2 (2) with the atomic
numbering scheme. Thermal ellipsoids are drawn at the level of 50%
probability.
Fig. 4. ORTEP drawing of Ru(C6H5CO2)2(CO)4(py)2 (4) with the
atomic numbering scheme. Thermal ellipsoids are drawn at the level
of 50% probability.

250
L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
3. Experimental
Ru(I) is completed by two carbonyl groups trans to
the benzoates and a pyridine ligand trans to the Ru–
Ru bond. The coordination geometry of the Ru(I) is
similar to that of the Ru(II) in 2, except for the
Ru–Ru bond in place of one of the Ru–N(pyridyl)
bonds in 2. The distortion of the octahedron of Ru(I)
is similar to that in 2 (av. N–Ru–Ru, 161.1(9)°). The
3.1. Materials
The ligand tris(2-pyridylmethyl)ammonium perchlo-
rate (tpa·3HClO4) was prepared as described in the
literature [17]. All other commercially available
reagents were used as purchased.
,
Ru(I)–CO bonds (av. 1.817(5) A) in 4 are shorter
than the Ru(II)–CO bonds in 2, in agreement with
lower CO stretching frequency in 4 (2000, 1960, 1940,
1910 cm−1). The mean Ru–N bond of 4 is 2.228(10)
3.2. Preparation of the complexes
3.2.1. [Ru(CH3CO2)(CO)(tpa)]ClO4·C6H5CH3 (1)
,
A, which is considerably longer than that in 2 due to
A suspension of tpa·3HClO4 (0.18 g, 0.3 mmol),
Ru3(CO)12 (0.065 g, 0.1 mmol) and acetic acid (1 ml)
in toluene was heated under reflux for 4 h under an
argon atmosphere. The suspension changed to a red–
orange and then to a yellow solution after 10 min.
The resulting solution was cooled to room tempera-
ture (r.t.) and was allowed to stand in a refrigerator
overnight to give yellow thin plate crystals of 1 (0.03
g, 17%). These crystals were found to be suitable for
X-ray structure analysis. Anal. Found: C, 49.76; H,
4.25; N, 8.22. Calc. for C28H29N4RuO7Cl (MW
670.08): C, 50.14; H, 4.33; N, 8.36%. UV–vis
(CH2C12 (nm)), 250, 385. IR (KBr (cm−1)), 1938
(w(CO)), 1620(s) (was(CO2)). 1H-NMR (CD2C12) l:
8.92 (1H, d, py-6-H trans to acetate), 8.67 (2H, d,
py-6-H cis to acetate), 7.15–7.75 (9H, m, py-H, and
C6H5CH3), 5.37 (2H, s, pyridylmethyl protons trans
to acetate), 5.20 (4H, d, pyridylmethyl protons cis to
acetate), 1.78 (3H, s, CH3CO2), 1.26 (3H, s,
C6H5CH3). Caution: perchlorate salts of metal com-
plexes with organic ligands are potentially explosive.
both trans influence of the Ru–Ru bond and larger
bonding radius of Ru(I). The Ru(I)–O distances (av.
,
2.121(5) A) are slightly longer than that in 2.
1
2.3. H-NMR spectra
The 1H-NMR spectrum of 1 in CD2Cl2 indicates
that the compound has mirror symmetry and the ba-
sic structure found in the solid state is retained in
solution. The doublets centered at 8.92 and 8.67 ppm
in the integrated intensity ratio of 1:2 are attributed
to the 6-H protons on the pyridyl rings trans and cis
to the acetate group, respectively. It is thus concluded
that the acetate group rotates freely along the Ru–O2
bond, leading to the equivalence of both the cis
pyridyl rings. The other protons on the pyridyl rings
show signals in the range of 7.15–7.75 ppm which
are overlapped with the signals from the toluene
molecule. The methylene proton signals on the
pyridylmethyl groups trans and cis to the acetate lig-
and appear at 5.37 (s) and 5.20 (d) ppm, respectively,
in the integrated intensity ratio of 1:2. The singlet at
1.78 ppm is assigned to the acetate methyl protons.
The methyl proton signal from toluene appears at
1.26 ppm as a singlet.
3.2.2. Ru(pyCO2)2(CO)2 (2)
A suspension of 2-pyridinecarboxylic acid (0.072 g,
0.6 mmol) and Ru3(CO)12 (0.065 g, 0.1 mmol) in
toluene (20 ml) was refluxed under argon atmosphere
for 20 min to produce an orange precipitate. The
precipitate was washed with pentane (2×30 ml) and
dried in vacuum to produce 0.08 g of 2 (yield, 70%).
Single crystals suitable for X-ray structure determina-
tion were obtained by slow diffusion of pentane into
the solution of CH2C12. Anal. Found: C, 41.59; H,
1.92; N, 6.83. Calc. for Cl4H8N2RuO6 (MW 401.30):
C, 41.86; H, 1.99: N, 6.98%. IR (KBr (cm−1)) w(CO),
As expected for the two-fold symmetry indicated by
1
the solid-state structure, the H-NMR spectrum of 2
shows two equivalent pyridyl rings, similar to the case
in the closely related compound Ru(CH3CO2)2-
(CO)2(py)2 [5]. Two doublets centered at 8.55 and
8.21 ppm are assignable to the 6- and 3-H protons,
respectively, and two triplets at 8.13 and 7.64 ppm
are due to the 4- and 5-H proton resonances, respec-
tively. Differing from compounds 1 and 2 which con-
tain the rigid pyridyl rings, complex 4 shows only
three sets of signals at 8.93 (d), 7.93 (t) and 7.57 (t)
in the intensity ratio of 2:1:2 attributable to the 2-
and 6-, 4-H, and 3- and 5-H protons, respectively,
indicating that the pyridyl rings freely rotate along
the Ru–N(py) bonds. The pyridyl proton signals of
compound 3 were not observed at the corresponding
region as expected for the paramagnetic nature.
1
2062, 1998; was(CO2), 1663, 1645. H-NMR (CD2C12)
l: 8.55 (2H, d, py-6-H), 8.21 (2H, d, py-3-H), 8.13
(2H, t, py-4-H), 7.64 (2H, t, py-5-H).
3.2.3. [Ru(pyCO2)3]·H2O (3)
A mixture of RuCl3·nH2O (0.13 g, 0.5 mmol),
sodium 2-pyridinecarboxylate (0.22 g, 0.15 mmol),
water (20 ml) and ethanol (20 ml) was heated at 60°C
for 3 h. The resulting solution was filtered and evapo-
rated under vacuum and dried. The diffusion of ether

L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
251
Table 2
Experimental details for crystallograpyic analyses of compounds 1–4
1
2
3
4
Formula
C28H29N4O7ClRu
670.08
Monoclinic
P21/c
9.178(4)
16.562(5)
19.397(5)
C
401.30
14H8N2O6Ru
C18H14N3O7Ru
485.39
Monoclinic
C2/c
30.490(10)
8.513(3)
13.988(1)
C31.5H24N2O8Ru2
760.68
Triclinic
Formula weight
Crystal system
Space group
Orthorhombic
Pbca
15.059(4)
15.310(7)
12.502(4)
(
P1
,
a (A)
12.988(6)
14.522(7)
9.371(4)
99.14(5)
108.22(4)
102.61(4)
1588(1)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
98.63(3)
94.19(1)
,
V (A)
Z
2915(1)
4
1.53
1368
6.81
2882(1)
8
1.85
1584
3621(1)
8
1.78
1944
9.15
Dc (g cm−3
)
1.59
758
10.02
F000
v (Mo–Ka) (cm−1
)
11.22
Scan mode
ꢀ–2q
10.0
1.21+0.3 tan q
50
Scan rate (deg min−1
Scan width (°)
2qmax (°)
)
10.0
8.0
12
0.94+0.30 tan q
50
1.23+0.40 tan q
1.05+0.30 tan q
60
55
Total reflections
No. observations (I\3(|)I)
Corrections
Trans. factors
No. variables
5456
2469
2546
1773
Lp, absorption
0.74–1.00
208
5681
2799
6193
4569
0.91–1.00
376
0.58–1.00
262
0.98–1.00
381
Residuals, R; Rw
GOF
0.064, 0.054
2.18
0.036, 0.035
2.32
0.052, 0.043
1.95
0.032, 0.031
2.14
D|
0.02
0.67
0.04
0.38
0.05
0.96
0.05
0.36
−3
,
Dz (e A
)
into the solution of acetone gave a brown crystalline
solid of 3 (0.08 g, 50%). Anal. Found: C, 44.86; H, 2.87;
N, 8.46. Calc. for C18H14N3RuO7 (MW 485.39): C,
44.50; H, 2.90; N, 8.64%. IR (KBr (cm−1)) was(CO2),
1675, 1657, 1625.
an orientation matrix for data collection were obtained
from a least-squares refinement using setting angles of
25 carefully centered reflections. The intensities of three
standard reflections were measured after every 150
reflections. No appreciable decay was observed. Data
were corrected for Lorentz and polarization effects
and/or an empirical absorption correction using the
program DIFABS [18]. The structures were solved by
heavy-atom Patterson methods and expanded using
Fourier techniques. Non-hydrogen atoms were refined
anisotropically. Hydrogen atoms were located from
difference Fourier maps or added on ideal positions.
Structures were refined by the block-diagonal-matrix
followed by full-matrix least-squares (final cycle)
method. The minimized function was ꢀw(ꢁFoꢁ−ꢁFcꢁ)2,
where w=[|c2(Fo)+p2Fo2/4]−1. Experimental details
for crystallographic analyses of compounds 1–4 are
listed in Table 2.
3.2.4. [Ru2(C6H5CO2)2(CO)4(py)2]·0.5C6H5CH3 (4)
A mixture of Ru3(CO)12 (0.065 g, 0.1 mmol), benzoic
acid (0.072 g, 0.6 mmol) and pyridine (1 ml) was
refluxed in toluene (50 ml) for l h under an argon
atmosphere to give a yellow solution. The solution was
evaporated in an open beaker to produce yellow crys-
tals of 4 (0.08 g, 80%). Anal. Found: C, 49.12; H, 3.08;
N, 3.52. Calc. for C31.5H24N2Ru2O8 (MW 760.68): C,
49.69; H, 3.15; N, 3.68%. IR (KBr (cm−1)) w(CO),
2000, 1960, 1940, 1910; was(CO2), 1630; ws(CO2), 1400.
1H-NMR (CD2C12) l: 8.93 (4H, d, py-2- and py-6-H),
7.86 (2H, t, py-4-H), 7.41 (4H, t, py-3- and 5-H), 7.85
(4H, d, o-ph), 7.38 (2H, t, p-ph), 7.23 (4H, t, m-ph).
3.4. Other measurements
3.3. X-ray crystallography
IR spectra were recorded on a Hitachi 270-50 in-
frared spectrophotometer. The H-NMR spectra were
1
Intensity data for compounds 1–4 were collected on
obtained at 270 MHz with a Jeol JNM-EX270 spec-
trometer. UV–vis spectra were recorded on a Jasco
Ubest-30 spectrophotometer at r.t.
a
Rigaku AFC-5R diffractometer with graphite-
,
monochromated Mo–Ka (u=0.71069 A) and a rotat-
ing anode generator at r.t. (23°C). Cell constants and

252
L. Xu, Y. Sasaki / Journal of Organometallic Chemistry 585 (1999) 246–252
[3] M. Rotem, I. Goldberg, U. Shmueli, Y. Shvo, J. Organomet.
4. Supporting material
Chem. 314 (1986) 185.
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cio, F. Piacenti, J. Organomet. Chem. 476 (1986) 7.
[5] D.S.C. Black, G.B. Deacon, N.C. Thomas, Aust. J. Chem. 35
(1982) 2445.
A listing of the atomic coordinates and thermal
parameters, complete bond lengths and angles of com-
pounds l–4 are available on request from the authors.
[6] L. Xu, Y. Sasaki, Inorg. Chem. Commun. 2 (1999) 121.
[7] T. Kojima, Chem. Lett. (1996) 121.
[8] M. Yamaguchi, H. Kousaka, T. Yamagishi, Chem. Lett. (1997)
769.
Acknowledgements
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suda, Inorg. Chem. 37 (1998) 4076.
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[13] B.P. Sullivan, J.V. Casper, S.R. Johnson, T.J. Meyer,
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Yamaguchi, M. Tominaga, I. Taniguchi, T. Ito, Inorg. Chem. 35
(1996) 6724.
We are grateful to the Japan Society for the Promo-
tion of Science for Research Fellowship to L.X. Grant-
in-Aids Nos. 09237106 and 10149102 (Priority Areas of
‘Electrochemistry of Ordered Surfaces’ and ‘Metal-As-
sembled Complexes’) from Ministry of Education, Sci-
ence, Sports and Culture, Japan, are gratefully
acknowledged.
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Richardson, Organometallics 17 (1998) 5178.
[16] B.I. Kilbourn, unpublished result cited in J.G. Bullitt, F.A.
Cotton, Inorg. Chim. Acta 5 (1971) 406.
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