Sawhorse-type diruthenium tetracarbonyl complexes containing biologically relevant acids

Article abstract of DOI:10.1016/j.ica.2012.09.034

The reaction between the biologically active acids probenecid (HO ₂CC₁₂H₁₈NO₂S), indomethacin (HO ₂CC₁₈H₁₅ClNO₂) and sulindac (HO ₂CC₁₉H₁₆FOS) with Ru₃(CO) ₁₂, followed by addition of axial ligands (L), such as pyridine, triphenylphosphine, or 5-(4-pyridyl)-10,15,20-triphenylporphyrin, generates a series of stable diruthenium tetracarbonyl complexes of the formula Ru ₂(CO)₄(μ₂-η²-O ₂CC₁₂H₁₈NO₂S)₂L ₂, Ru₂(CO)₄(μ₂-η²- O₂CC₁₈H₁₅ClNO₂)₂L ₂ and Ru₂(CO)₄(μ₂- η²-O₂CC₁₉H₁₆FOS) ₂L₂, respectively. The molecular structure of 1a · C₆H₆ was solved by single-crystal X-ray structure analysis and a typical diruthenium tetracarbonyl backbone bridged by the carboxylato ligands and two axial triphenylphosphine ligands was revealed. The benzene molecule sits between two probenecid units, and is involved in π-stacking interactions with the aromatic part of probenecid. Despite the presence of biologically relevant derivatives and carbonyl groups within the sawhorse-type dinuclear complexes, all systems show no cytotoxicity towards human cancer cells, presumably due to the high lipophilicity of these neutral complexes.

Full text of DOI:10.1016/j.ica.2012.09.034

Inorganica Chimica Acta 394 (2013) 723–728
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Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Sawhorse-type diruthenium tetracarbonyl complexes containing biologically
relevant acids
⇑
Justin P. Johnpeter, Bruno Therrien
Institut de Chimie, Université de Neuchâtel, Avenue de Bellevaux 51, CH-2000 Neuchâtel, Switzerland
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 22 June 2012
Received in revised form 25 September 2012
Accepted 26 September 2012
Available online 12 October 2012
The reaction between the biologically active acids probenecid (HO2CC12H18NO2S), indomethacin
(HO2CC18H15ClNO2) and sulindac (HO2CC19H16FOS) with Ru3(CO)12, followed by addition of axial ligands
(L), such as pyridine, triphenylphosphine, or 5-(4-pyridyl)-10,15,20-triphenylporphyrin, generates a ser-
ies of stable diruthenium tetracarbonyl complexes of the formula Ru2(CO)4(l2
-g
2-O2CC12H18NO2S)2L2,
Ru2(CO)4(l2
-
g
2-O2CC18H15ClNO2)2L2 and Ru2(CO)4(l2 2-O2CC19H16FOS)2L2, respectively. The molecular
-g
structure of 1a Á C6H6 was solved by single-crystal X-ray structure analysis and a typical diruthenium
Keywords:
tetracarbonyl backbone bridged by the carboxylato ligands and two axial triphenylphosphine ligands
Dinuclear complexes
Carbonyl ligands
Carboxylato bridges
Ruthenium
Porphyrin ligands
Biologically active acids
was revealed. The benzene molecule sits between two probenecid units, and is involved in
p-stacking
interactions with the aromatic part of probenecid. Despite the presence of biologically relevant deriva-
tives and carbonyl groups within the sawhorse-type dinuclear complexes, all systems show no cytotox-
icity towards human cancer cells, presumably due to the high lipophilicity of these neutral complexes.
Ó 2012 Elsevier B.V. All rights reserved.
1. Introduction
addition of two-electron donor ligands (L), sawhorse-type
dinuclear tetracarbonyl complexes of the general formula Ru2(CO)4
Carbon monoxide and nitric oxide have now been recognized as
two essential signaling agents in the body [1]. Despite the CO ability
to bind to hemoglobin and inhibit the respiratory cycle, evidence
has been found that CO possesses valuable anti-inflammatory,
vasodilatory and anti-apoptotic therapeutic effects [2]. In that re-
spect, complexes able to release CO in biological media have been
studied by Mann and his co-workers. For example, the ruthenium
(l2-g
2-O2CR)2L2 offer versatility and ease of preparation to
generate biologically relevant ruthenium carbonyl complexes [8].
Recently, we have shown that porphyrin-derived diruthenium
tetracarbonyl complexes possess interesting phototoxicity towards
female reproductive cancer cells [9], while sawhorse diruthenium
complexes derived from biological active acids such as aspirin,
ibuprofen, ethacrynic acid and chlorambucil were not cytotoxic
due to their low solubility in water [10] (see Chart 2). Consequently,
a new series of sawhorse-type diruthenium tetracarbonyl com-
plexes incorporating other biologically relevant carboxylic acids
has been synthesized. Three commercially available carboxylic
acids were selected for their therapeutic properties (see Chart 2):
Probenecid, an uricosuric drug [11]; indomethacin and sulindac,
complexes {Ru(l-Cl)Cl(CO)3}2 (tricarbonyldichlororuthenium(II)
dimer) and Ru(CO)3Cl(glycinate) (tricarbonylchloro(glycina-
to)ruthenium(II)) (see Chart 1), two known CO-releasing molecules
(CORMs), have shown anti-microbial activity on several types of
bacteria [3], as well as interesting in vivo activity in human [4].
In these CO-releasing complexes, the choice of exploiting ruthe-
nium centers was not accidental. Ruthenium complexes are show-
ing great promise as chemotherapeutic agents [5], and the ability of
ruthenium to mimic iron in biological environments gives to ruthe-
nium complexes several interesting properties in designing metal-
based drugs [5]. In addition, the chemistry of ruthenium carbonyl
complexes is well developed and known for many years [6]. Among
ruthenium carbonyl complexes, Lewis and coworkers have re-
ported in 1969 the first sawhorse-type diruthenium tetracarbonyl
complexes [7]. Obtained from the reaction of Ru3(CO)12 with car-
boxylic acids (RCO2H) in tetrahydrofuran at reflux, followed by
two anti-inflammatory agents [12]. All Ru2(CO)4(l2
complexes were fully characterized with being pyridine
-g
2-O2CR)2L2
L
(NC5H5), triphenylphosphine (PPh3) or 5-(4-pyridyl)-10,15,20-tri-
phenylporphyrin (C43H29N5).
2. Results and discussion
Dodecacarbonyltriruthenium (Ru3(CO)12
)
reacts with an
excess of the biologically relevant carboxylic acids, probenecid
(C13H19NO4S), indomethacin (C19H16ClNO4), and sulindac (C20H17
FO3S) in refluxing tetrahydrofuran (thf) to yield a solution contain-
⇑
Corresponding author. Tel.: +41 (0)32 718 24 99; fax: +41 (0)32 718 25 11.
E-mail address: bruno.therrien@unine.ch (B. Therrien).
ing the thf intermediates Ru2(CO)4(l2-g
2-O2CC12H18NO2S)2(thf)2,
0020-1693/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.ica.2012.09.034

724
J.P. Johnpeter, B. Therrien / Inorganica Chimica Acta 394 (2013) 723–728
containing axial triphenylphosphine ligands was isolated in suffi-
cient yield.
All complexes are air stable, and compounds 1a, 1b, 2a, 2b, 3b
CO
Ru
Cl
CO
Ru
Cl
CO
Ru
Cl
Cl
Cl
OC
OC
OC
OC
CO
CO
NH2
O
are yellow crystalline powders, while 1c and 2c are purple in color
due to the presence of the porphyrin ligands. All complexes have
been characterized by IR, NMR, MS, UV–Vis spectroscopy (1c and
2c) as well as by elemental analysis. In the infrared spectra, the
Ru2(CO)4 sawhorse unit exhibits the characteristic three-band pat-
tern for the m(CO) absorption at 1950, 1975 and 2020 cmÀ1 [8]. In
addition, the two carboxylato bridges show absorption for the
m(OCO) frequencies around 1550 cmÀ1, whilst for complexes 1c
and 2c, a strong absorption centered at 1580 cmÀ1 corresponding
O
tricarbonyltrichloro ruthenium(II) dimer tricarbonylchloro(glycinato)ruthenium(II)
(CORM-2) (CORM-3)
Chart 1. Examples of CO-releasing ruthenium complexes [2].
Ru2(CO)4(l2-g -g
2-O2CC18H15ClNO2)2(thf)2 and Ru2(CO)4(l2 2-O2
to m
(NCN), along with a strong absorption at 1224 cmÀ1 for N–H
CC19H16FOS)2(thf)2, respectively. These labile dinuclear thf inter-
mediates further react with two electron donor ligands (L), such
as pyridine (NC5H5) (a), triphenylphosphine (PPh3) (b) or 5-(4-pyr-
idyl)-10,15,20-triphenylporphyrin (C43H29N5) (c), to generate in
deformation and a medium absorption at 3055 cmÀ1 attributed
to the m(CH) of the porphyrinic axial ligands can be observed. The
UV–Vis spectra of complexes 1c and 2c display an intense Soret
band around 418 nm, and four Q bands between 515 and 645 nm
(Table 1). As previously observed with analogous sawhorse-type
complexes with porphyrinic ligands [9], the absorption bands of
the uncoordinated porphyrinic ligand and those observed after
coordination to the diruthenium backbone remain identical,
moderate yields the stable dinuclear complexes Ru2(CO)4(l2
O2CC12H18NO2S)2L2 (L = NC5H5, 1a; PPh3, 1b; C43H29N5, 1c),
Ru2(CO)4(l2
2-O2CC18H15ClNO2)2L2 (L = NC5H5, 2a; PPh3, 2b;
C43H29N5, 2c), and Ru2(CO)4(l2
2-O2CC19H16FOS)2L2 (L = PPh3,
3b) (Fig. 1). Within the sulindac series, only the complex
- -
g2
-
g
-
g
Cl
Cl
O
O
OH
H
ibuprofen
OH
CH3
OH
Cl
CH3
CH3
O
CH3
N
HO
O
O
Cl
O
H3C
O
O
HO
aspirin
ethacrynic acid
Cl
chlorambucil
F
O
CH3
O
N
CH3
O
CH3
H3C
N
HO
O
H3C
S
S
O
O
O
O
CH3
OH
probenecid
indometacin
sulindac
Chart 2. Biologically active carboxylic acids incorporated within sawhorse-type diruthenium tetracarbonyl complexes.
S
O
O
S
F
N
S
N
S
O
O
O
F
O
O
O
O
O
N
O
N
O
O
O
O
O
O
O
O
O
O
O
Cl
L
Ru Ru
L
Ru Ru
L
Ru Ru
L
L
L
Cl
C
C
C
C
C
C
C
O
C
O
C
O
C
O
C
O
C
O
O
O
O
O
O
O
1
2
3
Ph
N
HN
L
=
PPh3
N
N
Ph
NH
N
a
c
b
Ph
Fig. 1. Sawhorse-type diruthenium tetracarbonyl complexes 1–3 containing biologically relevant acids, probenecid (1), indomethacin (2) and sulindac (3).

J.P. Johnpeter, B. Therrien / Inorganica Chimica Acta 394 (2013) 723–728
725
Table 1
The unit cell of 1a contains a molecule of benzene, which is lo-
cated between the two probenecid units of 1a, thus filling some of
the voids in the crystals. These benzene molecules form weak
The electronic absorption spectra of complexes 1c, 2c and the porphyrinic ligand (c)
(10À6 M concentration) in dichloromethane at room temperature.
Compound
Soret band
Q band IV
Q band III
Q band II
Q band I
slipped-parallel and T-shaped
p-stacking interactions with the
neighboring phenyl ring of the probenecid moieties. However,
more voids remain in the crystal packing, which seem to be empty
despite being of approximately 185 Å3: No significant residual den-
sities being observed in those empty spaces. Empty channels are
observed along the a axis and represent almost 7% of the total vol-
ume within the unit cell, see Fig. 3.
1c
2c
c
418
418
415
515
515
514
551
551
548
590
590
589
646
645
645
suggesting no perturbation of the porphyrin
coordination.
p
-orbitals upon
The NMR spectrum of all complexes was measured in CDCl3 at
room temperature. All spectra show the signals corresponding to
the bridging and axial ligands. For example, the 1H NMR spectra
of 1c and 2c display similar patterns for the protons of the coordi-
nated 5-(4-pyridyl)-10,15,20-triphenylporphyrin units. The N–H
protons are observed at d = -2.7 ppm, while two multiplets at 7.8
and 8.2 ppm are found in the aromatic region corresponding to
the protons of the phenyl rings of the porphyrin ligands, whereas
the pyrrolic protons are found between 8.9 and 9.0 ppm. The
13C{1H} NMR spectra of this type of complexes show signals for
the terminal carbonyl groups (CO) and the carboxylato bridges
The effect of the organometallic complexes 1–3 was investi-
gated in vitro on human ovarian cancer cells (A2780). The com-
plexes were first dissolved in dimethyl sulfoxide and then
diluted in complete medium (RPMI 1640 medium) to the desired
concentrations, the dimethyl sulfoxide concentration remaining
below 5% v/v. In all cases, after cell exposure at 37 °C to increasing
concentrations of complexes, precipitation of the complexes in the
culture medium occurred and accordingly no cytotoxicity was
observed.
In conclusion, we have synthesized and characterized seven
new sawhorse-type diruthenium tetracarbonyl complexes with
pyridine, triphenylphosphine, 5-(4-pyridyl)-10,15,20-triphenyl-
porphyrin as axial ligands and containing biologically relevant
acids as carboxylato bridging ligands. However, the limited solubil-
ity of these complexes in aqueous medium resulted in no cytotox-
icity for these systems against human cancer cells.
(
l2-g
2-O2CR) at 176 and 205 ppm, respectively. In addition, for
complexes 1b, 2b and 3b, in the 31P{1H} NMR spectra, a sharp sin-
glet is observed at ꢀ15 ppm which corresponds to the PPh3 axial
ligands. Overall, these data are consistent with the proposed
structures.
The molecular structure of 1a was further confirmed by a sin-
gle-crystal X-ray structure determination. Crystals were obtained
by the slow diffusion of benzene in a chloroform solution of 1a,
thus giving rise to a crystalline benzene solvate adduct (1a Á 0.5
C6H6). As expected, the molecular structure shows a normal
diruthenium tetracarbonyl core being completed with two pyri-
dine axial ligands and two carboxylato-probenecid ligands in the
equatorial positions, see Fig. 2. At 2.6701(7) Å, the Ru–Ru distance
is in the range of a single metal–metal bond, while the N–Ru–Ru–N
torsion angle is almost linear at 2.8(7)°. These data are comparable
to those observed in analogous C5H5N–Ru–Ru–NC5H5 sawhorse-
type diruthenium tetracarbonyl complexes [13]. Similarly, the
OCO bond angles of the carboxylato bridges in 1a, both being
125.4(5)°, differ only slightly from those observed in other
3. Experimental
3.1. General remarks
All manipulations were routinely carried out under nitrogen.
Organic solvents were degassed and saturated with nitrogen prior
to use. All reagents were purchased either from Aldrich or Fluka
and used as received, while Ru3(CO)12 [14] and 5-(4-pyridyl)-
10,15,20-triphenylporphyrin [15] were prepared according to pub-
lished methods. NMR spectra were recorded on a Bruker 400 MHz
spectrometer. IR spectra were recorded as KBr pellets on a Perkin–
Elmer 1720x FT-IR spectrometer (4000–400 cmÀ1). Electro-spray
mass spectra were obtained in positive-ion mode with an LCQ
Finnigan mass spectrometer. Elemental analyses were performed
by the Mikroelementarisches Laboratorium, ETH Zürich (Switzer-
land). UV–Vis optical spectra were measured by an Uvikon 930
spectrophotometer using quartz cell (1 cm). Column chromatogra-
phy was performed using silica gel 60 (63–200, 60 Å, Brunschwig).
Ru2(CO)4(l2-g
2-O2CR)2L2 complexes [10b,13].
3.2. Preparation of sawhorse-type diruthenium tetracarbonyl
complexes 1–3
A solution of Ru3(CO)12 (100 mg, 0.156 mmol) and the carbox-
ylic acid (0.470 mmol) in dry tetrahydrofuran (25 mL), was heated
at 120 °C in a pressure Schlenk tube for 18 h. Then, addition of
three equivalents of the axial ligand [1a, 2a (L = NC5H5); 1b, 2b,
3b (L = PPh3); 1c, 2c (L = C43H29N5)] followed by stirring at room
temperature for 3 h, affords the final products. The complexes
are isolated from the residue by precipitation from dichlorometh-
ane/pentane. In order to improve the purity, the raw products were
subjected to chromatography on silica gel using a dichlorometh-
ane/pentane mixture as eluent and the solid obtained was dried
under vacuum.
3.2.1. Ru2(CO)4(l2-g
2-O2CC12H18NO2S)2(NC5H5)2 (1a)
Fig. 2. ORTEP drawing of 1a Á 0.5 C6H6 at 50% probability level ellipsoids with
hydrogen atoms omitted for clarity. Selected bond lengths (Å) and angles (°): Ru1–
Ru2 2.6701(7), Ru1–N3 2.213(5), Ru2–N4 2.216(5), Ru1–O1 2.120(4), Ru1–O5
2.126(4), Ru2–O2 2.143(4), Ru2–O6 2.123(4), O1–C1–O2 125.4(5), O5–C14–O6
125.4(5), O1–Ru1–O5 83.15(16), O2–Ru2–O6 83.55(16), N1–Ru1–Ru2–N2 2.8(7).
Yield: 130 mg (79%). 1H NMR (400 MHz, CDCl3): d = 0.83 (t, 12 H,
3J = 7 Hz, HCH3), 1.46–1.53 (m, 8 H, HCH2), 3.01 (t, 8 H, 3J = 8 Hz, HCH2),
7.56–7.60 (m, 4 H, Har), 7.72 (d, 4 H, 3J = 8 Hz, Har), 7.96–7.98 (m, 6 H,

726
J.P. Johnpeter, B. Therrien / Inorganica Chimica Acta 394 (2013) 723–728
Fig. 3. Crystal packing of 1a Á 0.5 C6H6 showing the empty voids of 185 Å3 along the a axis.
Har), 8.90–8.92 (m, 4 H, Har). 13C{1H} NMR (100 MHz, CDCl3):
d = 11.12 (4 C, CH3), 21.95 (4 C, CH2), 50.00 (4 C, CH2), 125.12 (4 C,
Car), 126.56 (4 C, Car), 130.19 (4 C, Car), 136.42 (2 C, Car), 137.72 (2
C, Car), 142.44 (4 C, Car), 151.81 (2 C, Car), 177.36 (2 C, CCOO), 203.74
Car), 127.98 (16 C, Car), 130.43 (4 C, Car), 130.83 (12 C, Car),
130.94 (12 C, Car), 134.52 (6 C, Car), 136.62 (2 C, Car), 141.76 (4 C,
Car), 150.00 (2 C, Car), 177.96 (2 C, CCOO), 204.01 (4 C, CCO). UV–
Vis [1.0 Â 10À6 M, CH2Cl2] kmax/nm
(e
 106 MÀ1 cmÀ1) = 418
(4 C, CCO). IR (KBr, cmÀ1
1976.27 m, (
)
m(OCO) 1558.17, m(CO) 1946.64 vs, (mCO
)
(3.251), 515 (0.230), 551 (0.121), 590 (0.074), 646 (0.055). IR
m
CO) 2026.98 vs. ESI-MS (positive mode): m/z = 935.58
(KBr, cmÀ1): m(porph N–H) 1214.92, m(OCO) 1557.00, (
mCO) 1979.01 vs,
[M–NC5H5–CO+H]+. C40H46N4O12Ru2S2 (1041.08) C 46.15, H 4.45,
N 5.38. Found: C 46.27, H 4.42, N 5.31%.
(mCO) 1976.27 m, (mCO) 2028.45 vs, (mC–H aro) 3056.83 m. ESI-MS
(positive mode): m/z = 1501.23 [M–C43H29N5+H]+. C116H94N12O12
Ru2S2 Á 2 H2O (2150.36) C 64.79, H 4.59, N 7.82. Found: C 64.70,
H 4.64, N 7.65%.
3.2.2. Ru2(CO)4(l2-g
2-O2CC12H18NO2S)2(PPh3)2 (1b)
Yield: 159 mg (72%). 1H NMR (400 MHz, CDCl3): d = 0.86 (t, 12
H, 3J = 7 Hz, HCH3), 1.46–1.52 (m, 8 H, HCH2), 3.01 (t, 8 H, 3J = 7 Hz,
3.2.4. Ru2(CO)4(l2-g
2-O2CC18H15ClNO2)2(NC5H5)2 (2a)
H
CH2), 7.10 (d, 4 H, 3J = 8 Hz, Har), 7.39–7.49 (m, 22 H, Har), 7.60–
Yield: 60 mg (32%) 1H NMR (400 MHz, CDCl3): d = 2.12 (s, 6 H,
7.65 (m, 12 H, Har). 13C{1H} NMR (100 MHz, CDCl3): d = 11.14 (4
C, CCH3), 21.92 (4 C, CCH2), 49.89 (4 C, CCH2), 126.20 (4 C, Car),
128.57 (12 C, Car), 129.90 (6 C, Car), 130.44 (4 C, Car), 133.13 (12
C, Car), 133.71 (6 C, Car), 136.41 (2 C, Car), 142.46 (2 C, Car),
179.16 (2 C, CCOO), 205.08 (4 C, CCO). 31P{1H} NMR (162 MHz,
HCH3), 3.47 (s, 4 H, HCH2), 3.67 (s, 6 H, HCH3), 6.64 (dd, 2 H,
3J = 9 Hz, 4J = 2 Hz, Har), 6.83 (d, 2 H, 4J = 2 Hz, Har), 6.93 (d, 2 H,
3J = 9 Hz, Har), 7.19 (dd, 4 H, 3J = 7 Hz, 4J = 2 Hz Har), 7.43 (d, 4 H,
3J = 8 Hz, Har), 7.57 (d, 4 H, 3J = 8 Hz, Har), 7.73 (t, 2 H, 3J = 8 Hz,
Har), 8.42 (d, 4 H, 3J = 5 Hz, Har). 13C{1H} NMR (100 MHz, CDCl3):
d = 13.21 (2 C, CCH3), 32.25 (2 C, CCH2), 55.44 (2 C,CCH3), 101.95 (2
C, Car), 111.14 (2 C, Car), 114.66 (2 C, Car), 115.13 (2 C, Car),
124.57 (4 C, Car), 129.01 (2 C, Car), 130.77 (4 C, Car), 131.03 (4 C,
Car), 131.16 (2 C, Car), 134.00 (2 C, Car), 134.79 (2 C, Car), 137.11
(2 C, Car), 139.06 (2 C, Car), 151.63 (4 C, Car), 155.84 (2 C, Car),
168.23 (2 C, CCON), 183.66 (2 C, CCOO), 203.93 (4 C, CCO). IR (KBr,
CDCl3) d = 18.20 ppm. IR (KBr, cmÀ1
) m(OCO) 1558.06, m(CO) 1957.11
vs, (mCO) 1983.87 m, (mCO) 2026.80 vs. ESI-MS (positive mode):
m/z = 1431.13 [M+Na]+. Anal. Calc. for C66H66N2O12P2Ru2S2
(1407.45) C 56.32, H 4.73, N 1.99. Found: C 56.60, H, 4.90, N 2.00%.
3.2.3. Ru2(CO)4(l2-g
2-O2CC12H18NO2S)2(C43H29N5)2 (1c) [16]
cmÀ1): m(OCO) 1581.79, (
mCO) 1936.73 vs, (mCO) 1970.86 m, (mCO)
Yield: 40 mg (57%) 1H NMR (400 MHz, CDCl3): d = À2.72 (s, 4 H,
NH), 0.80 (t, 12 H, 3J = 7 Hz, HCH3), 1.47–1.54 (m, 8 H, HCH2), 3.02 (t,
8 H, 3J = 8 Hz, HCH2), 7.78–7.86 (m, 22 H, Hporph and Har), 8.23–8.25
(m, 12 H, 3J = 8 Hz, Hporph), 8.31 (d, 4 H, 3J = 8 Hz, Har), 8.51 (d, 4 H,
3J = 6 Hz, Har), 8.90 (s, 8 H, Hporph), 9.02 (s, 8 H, Hporph), 9.40 (d, 4 H,
3J = 6 Hz, Hporph). 13C{1H} NMR (100 MHz, CDCl3): d = 11.10 (4 C,
2022.40 vs. ESI-MS (positive mode): m/z = 1187.02 [M+H]+. Anal.
Calc. for C52H40Cl2N4O12Ru2 (1185.94) C 52.66, H 3.40, N 4.72.
Found: C 52.39, H 3.59, N 4.60%.
3.2.5. Ru2(CO)4(l2-g
2-O2CC18H15ClNO2)2(PPh3)2 (2b)
CCH3), 21.95 (4 C, CCH2), 50.02 (4 C, CCH2), 114.67 (8 C, Car),
Yield: 277 mg (83%) 1H NMR (400 MHz, CDCl3): d = 1.76 (s, 6 H,
120.92 (6 C, Car), 126.74 (4 C, Car), 126.83 (4 C, Car), 127.90 (12 C,
HCH3), 3.31 (s, 4 H, HCH2), 3.63 (s, 6 H, HCH3), 6.68- (br-s, 2 H,

J.P. Johnpeter, B. Therrien / Inorganica Chimica Acta 394 (2013) 723–728
727
3J = 9 Hz, Har), 6.9 (d, 2 H, 4J = 2 Hz, Har), 7.01 (d, 2 H, 3J = 9 Hz Har),
Table 2
7.14–7.19 (m, 18 H, Har), 7.21 (d, 2 H, 3J = 7 Hz, Har), 7.32 (t, 6 H,
3J = 7 Hz, Har), 7.38–7.42 (m, 12 H, Har). 13C{1H} NMR (100 MHz,
CDCl3): d = 12.95 (2 C, CCH3), 32.32 (2 C, CCH2), 55.48 (2 C, CCH3),
101.19 (2 C, Car), 111.35 (2 C, Car), 114.54 (2 C, Car), 114.92 (2 C,
Car), 128.2 (12 + 6 C, Car), 128.78 (4 C, Car), 129.65 (2 C, Car),
130.89 (12 C, Car), 133.34 (4 C, Car), 133.49 (6 C, Car), 133.66 (2 C,
Car), 133.84 (2 C, Car), 134.86 (2 C, Car), 138.68 (2 C, Car), 156.06
(2 C, Car), 167.98 (2 C, CCON), 185.77 (2 C, CCOO), 204.95 (4 C, CCO).
31P{1H} NMR (162 MHz, CDCl3) d = 12.99 ppm. IR (KBr, cmÀ1):
Crystallographic and structure refinement parameters for complex 1a Á 0.5 C6H6.
1a Á 0.5 C6H6
Chemical formula
Formula weight
Crystal system
Space group
Crystal color and shape
Crystal size
a (Å)
C43H49N4O12Ru2S2
1080.12
triclinic
ꢀ
P1 (No. 2)
yellow block
0.23 Â 0.19 Â 0.16
10.4848(6)
15.3189(11)
18.2466(12)
72.648(5)
84.706(5)
73.398(5)
2680.6(3)
2
b (Å)
c (Å)
m(OCO) 1578.77, (
vs. ESI-MS (positive mode): m/z = 1575.12 [M+Na]+. Anal. Calc. for
78H60Cl2N2O12P2Ru2 (1552.31) C 60.35, H 3.90, N 1.80. Found: C
60.08, H 4.08, N 1.81%.
mCO) 1950.87 vs, (mCO) 1980.63 m, (mCO) 2023.55
a
(°)
b (°)
C
c
(°)
V (Å3)
Z
3.2.6. Ru2(CO)4(l2-g
2-O2CC18H15ClNO2)2(C43H29N5)2 (2c) [16]
T (K)
173(2)
1.338
0.697
Dc (gÁcmÀ3
)
Yield: 107 mg (86%) 1H NMR (400 MHz, CDCl3): d = À2.74 (s, 4
H, HNH), 2.41 (s, 6 H, HCH3), 3.67 (s, 6 H, HCH2), 3.84 (s, 4 H, HCH3),
6.64 (dd, 2 H, 3J = 9 Hz, 4J = 2 Hz, Har), 6.71 (d, 2 H, 3J = 9 Hz, Har),
6.98 (d, 4 H, 3J = 8 Hz, Har), 7.15 (d, 2 H, 4J = 2 Hz, Har), 7.35 (d, 4
H, 3J = 8 Hz, Har), 7.79–7.85 (m, 18 H, Hporph), 8.11 (d, 4 H,
3J = 6 Hz, Hporph), 8.25–8.27 (m, 12 H, Hporph), 8.84–8.90 (m, 16 H,
Hporph), 8.96 (d, 4 H, 3J = 5 Hz, Hporph). 13C{1H} NMR (100 MHz,
CDCl3): d = 13.47 (2 C,CCH3), 32.53 (2 C, CCH2), 55.56 (2 C, CCH3),
102.56 (2 C, Car), 110.79 (2 C, Car), 110.82 (2 C, Car), 114.67 (2 C,
Car), 120.77 (8 C, Car), 126.72 (12 C, Car), 126.79 (4 C, Car), 128.73
(2 C, Car), 130.41 (4 C, Car), 130.87 (4 C, Car), 131.40 (2 C, Car),
133.70 (16 C, Car), 134.54 (2 C, Car), 135.29 (2 C, Car), 141.84 (2 C,
Car), 149.90 (4 C, Car), 152.00 (16 C, Car), 155.88 (2 C, Car), 168.12
l
(mmÀ1
)
Scan range (°)
1.58 < h < 29.26
14483
9716
Unique reflections
Observed reflections [I > 2
Rint
Final R indices [I > 2
R indices (all data)
r
(I)]
0.1231
r
(I)]*
0.0910, wR2 0.1523
0.1472, wR2 0.1734
1.131
Goodness-of-fit (GOF)
Maximum, Minimum,
D
q
/e (ÅÀ3
)
0.847 and 1.939
*
2
Structure was refined on F0
À1 = [
: wR2 = [R Rw , where
[w (F02–Fc2)2]/ (F02)2]1/2
w
R
(F02) + (aP)2 + bP] and P = [max(F02, 0) + 2Fc2]/3.
anisotropically, using weighted full-matrix least-square on F2.
Crystallographic details are summarized in Table 2. Fig. 2 was
drawn with ORTEP [18] and Fig. 3 with MERCURY [19].
(2 C,
CCON), 184.43 (2 C, CCOO), 204.25 (4 C, CCO). UV–Vis
[1.0 Â 10À6 M, CH2Cl2] kmax/nm (
e
 106 MÀ1 cmÀ1) = 418 (3.343),
515 (0.355), 551 (0.171), 590 (0.109), 645 (0.083). IR (KBr, cmÀ1):
m(porph
1224.17, m(OCO) 1580.28,
(
mCO
)
1942.78 vs,
(mCO)
N–H)
Acknowledgements
1975.35 m, (mCO) 2025.14 vs, (mC–H aro) 3056.41 m. ESI-MS (positive
mode): m/z = 616.25 [C43H29N5+H]+. Anal. Calc. for C128H88Cl2N12
O12Ru2 Á 3 H2O (2313.23) C 66.46, H 4.10, N 7.27. Found: C 66.55,
H 4.03, N 7.19%.
Financial support of this work by the Swiss National Science
Foundation and a generous loan of ruthenium chloride hydrate
from the Johnson Matthey Research Centre are gratefully
acknowledged.
3.2.7. Ru2(CO)4(l2-g
2-O2CC19H16FOS)2(PPh3)2 (3b)
Yield 54 mg (23%) 1H NMR (400 MHz, DMSO): d = 1.68 (s, 6 H,
HCH3), 2.80 (s, 6 H, HCH3), 3.18 (s, 4 H, HCH2), 6.35 (dd, 2 H,
3J = 9 Hz, 4J = 2 Hz, HCH2), 6.65–6.70 (m, 2 H, Har), 7.10–7.14 (m, 2
H, Har), 7.15 (s, 2 H, Har), 7.35–7.36 (m, 22 H, Har), 7.41–7.45 (m,
8 H, Har), 7.61 (d, 4 H, 3J = 8 Hz, Har), 7.77 (d, 4 H, 3J = 8 Hz, Har).
13C{1H} NMR (100 MHz, CDCl3): d = 9.87 (2 C, CCH3), 32.32 (2 C,
Appendix A. Supplementary material
CCDC 887790 contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif. Supplementary data associated with this article
can be found, in the online version, at http://dx.doi.org/10.1016/
j.ica.2012.09.034.
CCH2), 43.86 (2 C,CCH3), 105.95 (2 C, Car), 110.41 (2 C, Car), 123.28
(2 C, Car) 123.74 (4 C, Car), 127.01 (4 C, Car), 128.13 (12 + 6 C, Car),
129.57 (2 C, Car), 130.14 (2 C, Car), 133.09 (12 C, Car), 133.65 (6 C,
Car), 133.77 (2 C, Car), 137.05 (2 C, Car), 139.87 (2 C, Car), 141.87
(2 C, Car), 145.22 (2 C, Car), 147.33 (2 C, Car), 164.39 (2 C, Car),
184.93 (2 C, CCOO), 205.05 (4 C, CCO). 31P{1H} NMR (162 MHz,
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