On the synthesis and structures of the complexes [RuCl(L)(dppb)(N-N)] PF6 (L = CO, py or 4-NH2py; Dppb = 1,4- bis(diphenylphosphino)butane; N-N = 2,2′-bipyridine or 1,10-phenanthroline) and [(dppb)(CO)Cl2-Ru-pz-RuCl 2(CO)(dppb)] (pz = pyrazine)

Article abstract of DOI:10.1016/j.poly.2010.04.028

The Ru(P-P) unit (P-P = diphosphine) is recognized to be an important core in catalytic species for hydrogenation of unsaturated organic substrates. Thus, in this study we synthesized six new complexes containing this core, including the binuclear complex [(dppb)(CO)Cl₂Ru-pz-RuCl ₂(CO)(dppb)] (pz = pyrazine) which can be used as a precursor for the synthesis of cationic carbonyl species of general formula [RuCl(CO)(dppb)(N-N)] PF₆ (N-N = diimine). Complexes with the formula [RuCl(py)(dppb)(N-N)] PF₆ were synthesized by exhaustive electrolysis of these carbonyl compounds or from the precursors [RuCl₂(dppb)(N-N)]. The new complexes were characterized by microanalysis, conductivity measurements, IR and ³¹P{¹H} NMR spectroscopy, cyclic voltammetry and X-ray crystallography.

Full text of DOI:10.1016/j.poly.2010.04.028

Polyhedron 29 (2010) 2297–2303
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
On the synthesis and structures of the complexes [RuCl(L)(dppb)(N–N)]PF6 (L = CO,
py or 4-NH2py; dppb = 1,4-bis(diphenylphosphino)butane; N–N = 2,20-bipyridine
or 1,10-phenanthroline) and [(dppb)(CO)Cl2-Ru-pz-RuCl2(CO)(dppb)]
(pz = pyrazine)
Marilia I. Frazão Barbosa a, Eliana M.A. Valle a, Salete L. Queiroz b, Javier Ellena b, Eduardo E. Castellano b,
a,
Valéria R.S. Malta c, Jackson R. de Sousa d, Oscar Piro e, Márcio P. de Araujo f, , Alzir A. Batista
*
**
a Departamento de Química, Universidade Federal de São Carlos, CP 676, CEP 13565-905, São Carlos (SP), Brazil
b Universidade de São Paulo, CEP 13560-970, São Carlos (SP), Brazil
c Universidade Federal de Alagoas, Departamento de Química, CEP 57072-970, Maceio, Alagoas (AL), Brazil
d Universidade Federal do Ceará, Departamento de Química Orgânica e Inorgânica, CEP Fortaleza (CE), Brazil
e Universidad Nacional de La Plata, Departamento de Física, Facultad de Ciencias Exactas, Calle 115 y 49, Casilla de Correo 67, 1900 La Plata, Argentina
f Departamento de Química, Universidade Federal do Paraná, C.P. 19081, CEP 81531-980, Curitiba, PR, Brazil
a r t i c l e i n f o
a b s t r a c t
Article history:
The ‘‘Ru(P–P)” unit (P–P = diphosphine) is recognized to be an important core in catalytic species for
hydrogenation of unsaturated organic substrates. Thus, in this study we synthesized six new complexes
containing this core, including the binuclear complex [(dppb)(CO)Cl2Ru-pz-RuCl2(CO)(dppb)] (pz = pyra-
zine) which can be used as a precursor for the synthesis of cationic carbonyl species of general formula
[RuCl(CO)(dppb)(N–N)]PF6 (N–N = diimine). Complexes with the formula [RuCl(py)(dppb)(N–N)]PF6
were synthesized by exhaustive electrolysis of these carbonyl compounds or from the precursors
[RuCl2(dppb)(N–N)]. The new complexes were characterized by microanalysis, conductivity measure-
ments, IR and 31P{1H} NMR spectroscopy, cyclic voltammetry and X-ray crystallography.
Ó 2010 Elsevier Ltd. All rights reserved.
Received 29 December 2009
Accepted 30 April 2010
Available online 7 May 2010
Keywords:
Ruthenium complexes
Diphenylphosphine
Structure
Carbonyl
1. Introduction
rium tuberculosis H37Rv ATCC 27264 [18]. Encouraged by these re-
sults, we are now investigating new routes to synthesize cationic
The ‘‘Ru(P–P)” core is recognized as an active catalytic species
for the hydrogenation of unsaturated organics [1–14]. In view of
this, several synthetic routes based on different precursors have
been developed to obtain complexes containing this type of unit.
In the past, our laboratory has prepared and isolated the complexes
[RuCl2(dppb)(N–N)], where N–N = a diimine ligand [15,16]. Some
of these complexes, synthesized from [RuCl2(dppb)PPh3], [Ru2Cl4
(dppb)3] or [RuCl3(dppb)H2O], have been used by us to catalyze
hydrogenation and hydrogen transfer [5,16,17]. More recently,
we have promoted reactions of some of these [RuCl2(dppb)
(N–N)] complexes with mono-anionic bidentate ligands such as
4,6-dimethyl-2-mercaptopyrimidine to obtain cationic complexes
that showed antitumor activity, with low IC50 values (i.e. strong
inhibition) against MDA-MB-231 human breast tumor cells, and
also acted as potential antimycobacterial drugs against Mycobacte-
complexes with the general formula [RuCl(L)(dppb)(N–N)]PF6,
where L is CO or N-heterocyclic ligands, which contain the
‘‘Ru(P–P)” core, where P–P = 1,4-bis(diphenylphosphino)butane,
to study their antimycobacterial and antitumoral activities. It is
worth mentioning that phosphine complexes of various transition
metals have been evaluated as potential antitumor agents in vari-
ous human tumor lines [19–21]. This paper describes the synthe-
sis, spectroscopic and electrochemical characterization and X-ray
structures of new complexes containing the 1,4-bis(diphenylphos-
phino)butane ligand.
2. Experimental
2.1. Materials for synthesis
All manipulations were carried out under purified argon with
standard Schlenk techniques. Reagent grade solvents were appro-
priately distilled and dried before use. All chemicals used were of
reagent grade or comparable purity. All chemicals were purchased
from Aldrich and were used as received. The precursors
* Corresponding author.
** Corresponding author.
E-mail addresses: mparaujo@quimica.ufpr.br (M.P. de Araujo), daab@power.
ufscar.br (A.A. Batista).
0277-5387/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2010.04.028

2298
M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
Fig. 1. ORTEP28 view of: (A) [Ru2Cl4(CO)2(pz)(dppb)2] (1), (B) tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀCH2Cl2 (2), tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀ0.3CH3OH (2)0, (C), tc-[RuCl(CO)(dppb)(-
phen)]PF6ꢀCH2Cl2 (4), ct-[RuCl(py)(dppb)(bipy)]PF6 (5), ct-[RuCl(4-NH2py)(dppb)(bipy)] PF6 (6), showing the atom labeling and the 50% probability ellipsoids [for (6), 30%].

M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
2299
cis-[RuCl2(P–P)(N–N)] (2,20-bipyridine or 1,10-phenanthroline)
and [Ru2Cl4(CO)2(dppb)3] were prepared according to the litera-
ture methods [15,22].
tions were made using the COLLECT program [23]; integration and
scaling of the reflections were performed with the HKL Denzo–
Scalepack system of programs [24]. Absorption correction was car-
ried out by the Gaussian method [25]. The structure was solved by
direct methods with SHELXS-97 [26]. The model was refined by full-
matrix least squares on F2, by means of SHELXL-97 [27]. All hydrogen
atoms were stereochemically positioned and refined with the rid-
ing model. The ORTEPs shown in Fig. 1 were prepared with ORTEP-
3 for Windows [28]. Hydrogen atoms on the aromatic rings were
set isotropic with a thermal parameter 20% greater than the equiv-
alent isotropic displacement parameter of the atom to which each
one is bonded. The data collected and some experimental details
are summarized in Table 1.
2.2. Instrumentation
The IR spectra of the complexes were collected on a FTIR Bo-
mem-Michelson 102 spectrometer in the 200–4000 cmꢁ1 region
using solid samples pressed into CsI pellets. All the NMR spectra
were recorded on a Bruker 9.4 T instrument (400 MHz for hydro-
gen frequency) for samples in CH2Cl2, using a capillary containing
D2O. Cyclic voltammetry (CV) experiments were carried out at
room temperature in CH2Cl2 containing 0.10 M Bu4N+ClO4 (TBAP)
(Fluka Purum), using a BAS-100B/W Bioanalytical Systems Instru-
ment; the working and auxiliary electrodes were stationary Pt
foils, a Lugging capillary probe was used and the reference elec-
trode was Ag/AgCl. Under these conditions, ferrocene is oxidized
at 0.43 V (Fc+/Fc). Microanalysis was performed by Microanalytical
Laboratory of Universidade Federal de São Carlos, São Carlos (SP),
using a Fisons CHNS, mod. EA 1108 elemental analyzer.
2.4. Synthesis
Throughout the text the first letter in the prefix to a complex
formula refers to the position of the CO relative to the chlorine
atom and the second letter refers to the same ligand relative to
the phosphorus atom.
2.3. X-ray crystallography
2.4.1. [Ru2Cl4(CO)2(pz)(dppb)2] (1)
Complex (1), [Ru2Cl4(CO)2(pz)(dppb)2], was prepared from
100 mg (0.0595 mmol) of [Ru2Cl4(CO)2(dppb)3] dissolved in CH2Cl2
(10 mL) and 5.6 mg (0.0700 mmol) pyrazine. The mixture was stir-
red for 48 h after that the volume of the solution was reduced to
1 mL and ether was added to precipitate the product, which was
washed with hexane and ether and dried under vacuum. Yield
Crystals of the complexes were grown by slow evaporation of
the solutions in dichloromethane/diethyl ether. The crystals were
mounted on an Enraf-Nonius Kappa-CCD diffractometer with
graphite monochromated Mo Ka (k = 0.71073 Å) radiation. The fi-
nal unit cell parameters were based on all reflections. Data collec-
Table 1
Crystallographic data for [Ru2Cl4(CO)2(pz)(dppb)2] (1), tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀCH2Cl2 (2), tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀ0.3CH3OH (2)0 tc-[RuCl(CO)(dppb)
(phen)]PF6ꢀCH2Cl2 (4), ct-[RuCl(py)(dppb)(bipy)]PF6 (5) and ct-[RuCl(4-NH2py)(dppb)(bipy)]PF6ꢀCH2Cl2 (6).
(1)
(2)
(2)0
(4)
(5)
(6)
Formula
Formula weight
T (K)
Crystal system
Space group
a (Å)
C
62H60Cl4N2O2P4ꢀRu2 C40H38Cl3F6N2OP3Ru C39.3H37.2ClF6N2O1.3P3Ru C42H38Cl3F6N2OP3Ru C43H41ClF6N3P3Ru
C44H44Cl3F6N4P3Ru
1043.20
120(2)
monoclinic
P21/n
19.227(1)
9.987(1)
25.161(1)
111.47(1)
4496.2(5)
4
1333.02
296(2)
monoclinic
P21/c
9.889(7)
14.217(2)
20.978(5)
90.63(2)
2949(2)
2
977.10
901.77
1001,12
943.26
293(2)
293(2)
293(2)
293(2)
orthorhombic
P212121
monoclinic
P21/c
orthorhombic
P 212121
monoclinic
P21/c
18.907(1)
18.910(3)
11.604(1)
15.3418(2)
18.6634(2)
14.1058(2)
96.5300(10)
4012.71(9)
4
11.80400(10)
18.7680(2)
19.0790(2)
10.27740(10)
27.2866(5)
15.0142(2)
102.3520(10)°.
4113.05(8)
4
b (Å)
c (Å)
b (°)
V (Å3)
4148.8(9)
4
4226.71(7)
4
Z
qcalcd (Mg m–3
)
1.501
0.847
1.564
0.749
1.493
0.639
1.573
0.737
1.523
0.630
1.541
0.696
Absorption coefficient
(mm–1
F(0 0 0)
)
1356
1976
1830
2024
1920
2120
Crystal size (mm3)
h Range for data
collection (°)
0.30 ꢂ 0.30 ꢂ 0.12
0.24 ꢂ 0.2 ꢂ 0.06
0.3 ꢂ 0.24 ꢂ 0.22
0.24 ꢂ 0.26 ꢂ 0.28
0.081 ꢂ 0.210 ꢂ 0.320 0.20 ꢂ 0.08 ꢂ 0.04
1.73–24.98
2.98–26.35
3.02–27.48
2.95–27.48
3.15–27.5
2.94–24.43
Index ranges
ꢁ11 6 h 6 11
0 6 k 6 16
0 6 l 6 24
5313
ꢁ23 6 h 6 22
ꢁ13 6 k 6 23
ꢁ14 6 l 6 13
18 908
ꢁ19 6 h 6 19
ꢁ24 6 k 6 23
ꢁ18 6 l 6 18
32 724
ꢁ15 6 h 6 15
ꢁ24 6 k 6 22
ꢁ24 6 l 6 23
ꢁ13 6 h 6 13
ꢁ34 6 k 6 35
ꢁ18 6 l 6 19
32 220
ꢁ22 6 h 6 22
ꢁ11 6 k 6 9
ꢁ29 6 l 6 29
22 088
Reflections collected
Reflections unique
5168 (0.0964)
8356 (0.0601)
9191 (0.0303)
9589 (0.0307)
9393 (0.0811)
7408 (0.076)
(Rint
)
Completeness to h
Data/restraints/
parameter
24.98°(100%)
5168/0/344
26.35°(98.6%)
8356/0/505
27.48°(99.7%)
9191/1/496
27.48°(99.2%)
9589/0/523
27.5°(99.3%)
9393/0/514
24.43°(99.6%)
7408/0/595
Maximum/minimum
transmission
0.9052 and 0.7852
0.940 and 0.856
0.841 and 0.769
0.843 and 0.800
1.165 and 0.856
0.973 and 0.873
Final R indices
[I > 2r(I)]
R indices (all data)
R1 = 0.0521,
wR2 = 0.1037
R1 = 0.2371,
wR2 = 0.1565
0.972
R1 = 0.0431,
wR2 = 0.1068
R1 = 0.0589,
wR2 = 0.1192
1.018
R1 = 0.0540,
wR2 = 0.1354
R1 = 0.0665,
wR2 = 0.1407
1.186
R1 = 0.0357,
wR2 = 0.0860
R1 = 0.0463,
wR2 = 0.0918
1.028
R1 = 0.0490,
wR2 = 0.1195
R1 = 0.0927,
wR2 = 0.1376
1.043
R1=0.073,
wR2 = 0.210
R1=0.097,
wR2 = 0.223
1.149
GOF on F2
Largest difference in
peak and hole
0.571 and ꢁ0.838
0.500 and ꢁ0.672
0.739 and ꢁ0.737
0.531 and ꢁ0.465
0.425 and ꢁ0.949
1.016, ꢁ0.769
(e Åꢁ3
)

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M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
60% (47.6 mg). Anal. Calc. for C62H60Cl4N2O2P4Ru2: C, 57.01; N,
2.32; H, 4.65. Found: C, 55.86; N, 2.21; H, 4.54%. X-ray suitable sin-
gle crystals were obtained from dichloromethane/ether solution,
by slow evaporation.
2.4.4. tc-[RuCl(CO)(dppb)(phen)]PF6 (4)
The complex (4), tc-[RuCl(CO)(dppb)(phen)]PF6 was prepared
analogously to (2), from 100.0 mg (0.0595 mmol) of [Ru2Cl4(-
CO)2(dppb)3] dissolved in CH3OH (10 mL), 35 mg (0.194 mmol) of
1,10-phenanthroline and 35 mg (0.215 mmol) NH4PF6. The mix-
ture was refluxed for 24 h, after that it was concentrated to approx-
imately 2 mL and a solid was precipitated with ether, filtered off,
and washed well with water and ether and dried under vacuum.
Yield: 60% (65.4 mg). Anal. Calc. for C41H36ClF6N2OP3Ru.CH2Cl2: C,
50.39; N, 2.80; H, 3.83. Found: C, 50.29; N, 2.79; H, 3.93%. X-ray
suitable single crystals were obtained by recrystallization in
dichloromethane, after leaving the solution undisturbed over the
bench top for 24 h.
2.4.2. tc-[RuCl(CO)(dppb)(bipy)]PF6 (2)
Complex (2), tc-[RuCl(CO)(dppb)(bipy)]PF6 was prepared from
50.0 mg (0.0298 mmol) of [Ru2Cl4(CO)2(dppb)3] dissolved in
´
CH2Cl2 (10 mL), 14.0 mg (0.0896 mmol) 2,2-bipyridine and 28.0
mg (0.172 mmol) NH4PF6. The mixture was refluxed for 6 h, after
that it was concentrated to approximately 2 mL and a solid was
precipitated with ether, washed well with water and ether and
dried under vacuum. Yield 53% (28.2 mg). Anal. Calc. for
C
39H36ClF6N2OP3Ru: C, 52.17; N, 3.41; H, 4.22. Found: C, 52.50;
2.4.5. tc-[RuCl(py)(dppb)(bipy))]PF6 (5)
N, 3.14; H, 4.07%. X-ray suitable single crystals were obtained from
dichloromethane/ether solution, by slow evaporation.
Besides the complex [Ru2Cl4(CO)2(dppb)3], [(dppb)(CO)Cl2-Ru-
pz-RuCl2(CO)(dppb)] can also be used as a precursor to obtain spe-
cies with the general formula [RuCl(CO)(dppb)(N–N)]PF6.
The complex (5), tc-[RuCl(py)(dppb)(bipy))]PF6 was prepared
by electrolyzing 50 mg (0.0560 mmol) of tc-[RuCl(CO)(dppb)
(bipy)]PF6 in acetonitrile at about 2.1 V in the presence of excess
pyridine (10 times), using NH4PF6 as the electrolyte, and then the
product was electrolyzed at 0.7 V. The solution containing the
reduced product was concentrated to approximately 2 mL and a
solid was precipitated with ether, rinsed well with water and ether
and dried under vacuum. Yield: 65% (34.3 mg). Anal. Calc. for
2.4.3. cc-[RuCl(CO)(dppb)(bipy)]PF6 (3)
The complex (3), cc-[RuCl(CO)(dppb)(bipy)]PF6 was prepared by
refluxing 100 mg (0.112 mmol) of tc-[RuCl(CO)(dppb)(bipy)]PF6 (2),
dissolved in a mixture of CH2Cl2 and CH3OH (10 mL/10 mL), for 24 h.
The volume of the solution was reduced to ca. 2 mL and ether was
added to precipitate a yellow solid, which was filtered off and
washed with ether and dried under vacuum. Yield: 86% (85.9 mg).
Anal. Calc. for C39H36ClF6N2OP3Ru: C, 52.91; N, 3.49; H, 3.95. Found:
C, 52.50; N, 3.14; H, 4.07%. X-ray suitable single crystals were ob-
tained from methanol/ether solution, by slow evaporation.
C43H41ClF6N3P3Ru: C, 54.68; N, 4.46; H, 4.40. Found: C, 54.75; N,
4.45; H, 4.38%. X-ray suitable single crystals were obtained from
dichloromethane/ether solution, by slow evaporation.
[RuCl(py)(dppb)(bipy)]PF6 was also obtained from the precur-
sor cis-[RuCl2(dppb)(bipy)] 50 mg (0.0662 mmol) dissolved in
CH2Cl2 (20 mL) and 16.2 lL (0.201 mmol) of pyridine. The mixture
was stirred for 3 h, after that NH4PF6 (17.5 mg, 0.107 mmol), dis-
solved in a minimum volume of CH3OH, was added. After 30 min
Cl
Ph3P
PPh3, CH3OH
RuCl3.XH2O
2-
Ru
3h
Δ,
Ph3P
PPh3
Cl
Cl
Cl
P
P
P
P
N
N
P
P
3-
3-
P
Ru
Cl
Ru
Cl
CO
OC
P-P
hexane
Δ, 6h
pyrazine
CH2Cl2
Cl
Cl
Cl
Cl
P
P
P
P
P
P
P
P
P
P
P
P
solid state
CO(g)
-
3
-
-
P
3
-
P
P
P
P
P
P
P
Ru
Cl
Ru
Cl
Ru
Cl
P
P
Ru
Cl
CO
OC
N-N / NH4PF6
Δ, 6h
CH3OH / CH2Cl2
Cl
N
P
P
P
P
P
P
N
N
CH3OH / CH2Cl2
24h
3-
3-
Ru
PF6
Ru
PF6
Δ,
N
Cl
CO
CO
Scheme 1. Synthetic route for the complexes (1–4).

M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
2301
of stirring, the solution was concentrated to about 1 mL and hex-
ane was added to precipitate the product which was washed with
water and ether and dried under vacuum. Yield: 54% (33.7 mg).
The IR spectra of the carbonyl complexes show typical mCO
bands around 1970 cmꢁ1. The complexes (2–6), in acetone, are
1:1 electrolyte as suggested by their observed molar conductivity
measurements (see Table 2).
The cyclic voltammograms of complexes (2–4) showed irrevers-
ible oxidation of RuII to RuIII at higher potentials than the reversible
process observed for complexes (5–6). This is a consequence of the
presence of the carbonyl ligand in the complexes (2–4). These data
are in Table 3.
The bond lengths (Å) and angles (°) for the complexes [Ru2Cl4(-
CO)2(pz)(dppb)2] (1), tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀCH2Cl2 (2) and
tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀ0.3CH3OH (2)0 are in Table 5; those
for the complexes tc-[RuCl(CO)(dppb)(phen)]PF6ꢀCH2Cl2 (4), ct-
[RuCl(py)(dppb)(bipy)]PF6 (5) and ct-[RuCl(4-NH2py)(dppb)(bi-
py)]PF6 (6) are in Table 5 and their ORTEP structures are shown
in Fig. 1.
Regarding complex (2), tc-[RuCl(CO)(dppb)(bipy)]PF6, seen in
Table 4, two structures were refined, one containing CH3OH
(monoclinic) and the other containing CH2Cl2 (orthorhombic). Both
unit cells for the complexes are shown in Fig. 2, and as can be seen,
while the monoclinic species, is centro-symmetric, the orthorhom-
bic, is not.
The distances for the Ru–Cl, Ru–P, Ru–N and C–O bonds and
bond angles found for the compounds are within the normal range
found for similar RuII complexes [29–36].
2.4.6. tc-[RuCl(4-NH2py)(dppb)(bipy)]PF6 (6)
The complex (6), tc-[RuCl(4-NH2py)(dppb)(bipy)]PF6 was first
obtained by electrolyzing 37 mg (0.0415 mmol) of tc-[RuCl(-
CO)(dppb)(bipy)]PF6 at about 2.1 V in the presence of excess of
4-aminopyridine (three times), using NH4PF6 as electrolyte, in ace-
tonitrile, and then the product was electrolyzed at 0.7 V. The solu-
tion containing the reduced product was concentrated to
approximately 2 mL and a solid was precipitated with ether, rinsed
well with water and ether and dried under vacuum. Yield: 60%
(23.9 mg). Anal. Calc. for C43H42ClF6N4P3Ru.C5H6N2: C, 54.19; N,
7.24; H, 4.48. Found: C, 54.78; N, 7.99; H, 4.60%.
[RuCl(4-NH2py)(dppb)(bipy)]PF6 was also obtained from
a
mixture of 100 mg (0.132 mmol) of the precursor cis-[RuCl2(dppb)
(bipy)] dissolved in CH2Cl2 (20 mL) and 37 mg (0.393 mmol) 4-
aminopyridine This solution was stirred for 20 h, after which
NH4PF6 44.0 mg (0.270 mmol), dissolved in a minimum volume
of CH3OH, was added. After 30 min of stirring the solution was
concentrated to about 1 mL and hexane was added to precipitate
the product which was washed with water and ether and dried un-
der vacuum. Yield: 69% (87.3 mg). X-ray suitable single crystals
were obtained from dichloromethane/ether solution, by slow
evaporation.
Table 3
Electrochemical data for complexes (1–6).
3. Results and discussion
Complex
Epa (V)
Epc (V)
E1/2 (V)
The synthesis of complexes (1–4) followed the Scheme 1 and
the complexes (5–6) followed the Scheme 2.
[Ru2Cl4(CO)2(pz)(dppb)2] (1)
0.87
2.11
2.10
2.10
1.17
1.08
tc-[RuCl(CO)(dppb)(bipy)]PF6 (2)
cc-[RuCl(CO)(dppb)(bipy)]PF6 (3)
tc-[RuCl(CO)(dppb)(phen)]PF6 (4)
ct-[RuCl(py)(dppb)(bipy)]PF6 (5)
ct-[RuCl(4-NH2py)(dppb)(bipy)]PF6 (6)
The 31P{1H} NMR spectra of complexes (3) and (6) exhibit two
doublets suggesting that their phosphorus atoms are not magnet-
ically equivalent, while for compounds (2), (4) and (5), only one
singlet is present in their spectra showing the equivalence of their
phosphorus atoms, trans to the nitrogen atoms in the 2,20-bipyri-
dine or 1,10-phenanthroline ligands (Table 2).
1.09
0.98
1.13
1.03
Epa = anodic peak potential; Epc = cathodic peak potential. The E1/2 values were
obtained by (Epa + Epc/2).
N
N
P
P
P
P
P
P
N
L
N
CH3OH / NH4PF6
CH2Cl2
3-
3-
PF6
Ru
Cl
Ru
Cl
+
NH4Cl
L
+
Cl
Scheme 2. General reaction for the synthesis of the ct-[RuCl(L)(dppb)(bipy)]PF6 complexes (5 and 6).
Table 2
31P{1H} NMR chemical shifts for the complexes (1–6), in CH2Cl2; infrared mCO (cmꢁ1), in CsI pellets and molar conductivity in acetone.
Complex
31P{1H}; (2Jp–p/Hz)
mCO (cmꢁ1
)
lS/cm (RT)
[Ru2Cl4(CO)2(pz)(dppb)2] (1)
ꢁ117.42 (s)
1958
1.2
ꢁ112.62/ꢁ111.60 (d)
ꢁ110.90(d)/ꢁ97.10 (d)
ꢁ95.66(m)
2Jp–p = 30 Hz
tc-[RuCl(CO)(dppb)(bipy)]PF6 (2)
cc-[RuCl(CO)(dppb)(bipy)]PF6 (3)
27.8 (s)
1970
1976
163.0
148.0
35.0 (d); 27.0 (d)
2Jp–p = 29.60 Hz
28.4 (s)
tc-[RuCl(CO)(dppb)(phen)]PF6 (4)
ct-[RuCl(py)(dppb)(bipy)]PF6 (5)
ct-[RuCl(4-NH2py)(dppb)(bipy)]PF6 (6)
1965
155.0
150.0
161.0
38.01 (s)
37.8 (d); 37.1 (d)
2Jp–p = 34.00 Hz
(s) = singlet; (d) doublet and (m) multiplet.

2302
M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
Table 4
Selected bond lengths (Å) and angles (°) for (1) [Ru2Cl4(CO)2(pz)(dppb)2], (2) [RuCl(CO)(dppb)(bipy)]PF6ꢀCH2Cl2 and (2)0 RuCl(CO)(dppb)(bipy)]PF6ꢀ0.3CH3OH.
1
2
20
Bond
Length (Å)
Bond
Length (Å)
Bond
Length (Å)
Ru–Cl(1)
Ru–Cl(2)
Ru–N
2.445(3)
2.432(3)
2.208(7)
1.839(14)
2.321(3)
2.337(3)
1.086(3)
1.320(13)
1.325(12)
Ru–Cl
2.4458(13)
2.155(4)
2.147(4)
1.847(5)
2.3820(13)
2.3749(2)
1.150(6)
1.335(7)
1.345(6)
Ru–Cl
2.4416(11)
2.155(3)
2.158(3)
1.846(5)
2.3737(10)
2.3902(10)
1.142(5)
1.337(6)
1.338(6)
Ru–N(1)
Ru–N(2)
Ru–C(1)
Ru–P(1)
Ru–P(2)
C(1)–O(1)
N(1)–C(11)
N(2)–C(2)
Ru–N(1)
Ru–N(2)
Ru–C(1)
Ru–P(1)
Ru–P(2)
C(1)–O(1)
N(1)–C(2)
N(2)–C(11)
Ru–C
Ru–P(1)
Ru–P(2)
C–O
N–C(41)
N–C(42)
Bond
Angle(°)
Bond
Angle(°)
Bond
Angles(°)
C–Ru–N
89.2(4)
C(1)–Ru–N(1)
C(1)–Ru–N(2)
N(2)–Ru–P(1)
C(1)–Ru–P(1)
C(1)–Ru–P(2)
N(1)–Ru–P(1)
92.47(19)
90.62(18)
74.90(16)
89.52(15)
96.05(15)
97.14(12)
C(1)–Ru–N(1)
C(1)–Ru–N(2)
N(1)–Ru–N(2)
C(1)–Ru–P(1)
C(1)–Ru–P(2)
N(1)–Ru–P(1)
85.76(15)
96.01(16)
75.72(13)
95.42(12)
89.49(12)
98.71(10)
C–Ru–Cl(1)
N–Ru–P(1)
C–Ru–P(1)
C–Ru–P(2)
P(2)–Ru–Cl(2)
175.1(4)
171.4(2)
91.1(4)
96.0(4)
175.14(11)
Table 5
Selected bond lengths (Å) and angles (°) for the (4) tc-[RuCl(CO)(dppb)(phen)]PF6ꢀCH2Cl2, (5) ct-[RuCl(py)(dppb)(bipy)]PF6 and (6) ct-[RuCl(4-NH2py)(dppb)(bipy)]PF6 complexes.
4
5
6
Bond
Length (Å)
Bond
Length (Å)
Bond
Length (Å)
Ru–N(1)
Ru–N(2)
C(13)–O(1)
Ru–P(1)
Ru–P(2)
Ru–Cl
2.161(3)
2.157(3)
1.133(4)
2.372(9)
2.370(8)
2.451(8)
Ru–N(L) trans P
Ru–N(bipy) trans P
Ru–N(bipy) trans Cl
Ru–P trans N(L)
Ru–P trans N(bipy)
Ru–Cl
2.215(3)
2.117(3)
2.073(3)
2.3242(9)
2.3483(9)
2.4252(8)
Ru–N(L) trans P
Ru–N(bipy) trans P
Ru–N(bipy) trans Cl
Ru–P trans N(L)
Ru–P trans N(bipy)
Ru–Cl
2.175(7)
2.130(7)
2.105(7)
2.335(2)
2.343(2)
2.425(2)
Bond
Angles(°)
Bond
Angles(°)
Bond
Angles(°)
C(13)–Ru(1)–N(2)
C(13)–Ru(1)–N(1)
C(13)–Ru(1)–P(2)
P(1)–Ru(1)–Cl(1)
N(2)–Ru(1)–P(2)
N(1)–Ru(1)–P(2)
C(13)–Ru(1)–P(1)
N(2)–Ru(1)–P(1)
N(1)–Ru(1)–P(1)
N(1)–Ru(1)–Cl(1)
C(13)–Ru(1)–Cl(1)
N(2)–Ru(1)–Cl(1)
89.93(13)
91.90(12)
95.95(10)
97.30(3)
98.15(7)
170.41(8)
90.22(11)
171.92(8)
95.63(8)
84.91(8)
172.09(11)
82.28(7)
Cl–Ru–N3(L
Cl–Ru–P2(trans
Cl–Ru–N2(bipy
88.3(9)
84.4(3)
92.9(9)
87.4(3)
101.6(8)
89.5(9)
93.5(3)
83.2(12)
77.9(12)
84.6(11)
93.8(9)
101.3(10)
Cl–Ru–N3(L
Cl–Ru–P2(trans
Cl–Ru–N2(bipy
90.7(2)
85.3(8)
91.3(2)
88.1(8)
97.8(2)
90.6(2)
94.0(8)
81.0(3)
77.6(3)
84.5(3)
94.4(2)
102.7(2)
trans P2)
trans P2)
L)
L)
trans P1)
trans P1)
Cl–Ru–P1(trans
P2–Ru–N1(bipy
P2–Ru–N2
P2–Ru–P1
N2–Ru–N3
N2–Ru–N1
N3–Ru–N1
P1–Ru–N3
P1–Ru–N1
Cl–Ru–P1(trans
P2–Ru–N1(bipy
P2–Ru–N2
P2–Ru–P1
N2–Ru–N3
N2–Ru–N1
N3–Ru–N1
P1–Ru–N3
P1–Ru–N1
bipy)
bipy)
trans Cl)
trans Cl)
Fig. 2. Unit cells of the complex (A) tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀCH2Cl2 (2) and (B) tc-[RuCl(CO)(dppb)(bipy)]PF6ꢀ0.3CH3OH (2)0.

M.I. Frazão Barbosa et al. / Polyhedron 29 (2010) 2297–2303
2303
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The binuclear complex [Ru2Cl4(CO)2(pz)(dppb)2] was derived
from the compound [Ru2Cl4(CO)2(dppb)3], showing that it is possi-
ble to change the bridge ligand in this complex. Thus, both com-
plexes can be used to obtain carbonyl complexes with the
general formula [RuCl(CO)(dppb)(N–N)]PF6, where N–N is a dii-
mine. Concomitant with electrolytic oxidation of the metal center
in the tc-[RuCl(CO)(dppb)(bipy)]PF6 complex, the CO ligand is dis-
sociated, generating new species with general formula ct-
[RuCl(L)(dppb)(bipy)]PF6, when L is dissolved in the medium.
These complexes can also be obtained from the respective precur-
sors cis-[RuCl2(dppb)(N–N)], by the replacement of one chlorine by
the monodentate ligand L, such as pyridine and its derivatives. In
both cases, the ligand L is trans positioned to the phosphorus
atoms and cis to the chloride.
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Göttingen, Göttingen, Germany, 1997.
5. Supplementary data
CCDC 712141, 712142, 712143, 712144, 712145 and 746016
contain the supplementary crystallographic data for (1), (2), (2)0,
(4), (5) and (6), respectively. These data can be obtained free of
charge via http://www.ccdc.cam.ac.uk/conts/retrieving.html, or
from the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44 1223 336 033; or e-mail:
deposit@ccdc.cam.ac.uk.
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Acknowledgements
We thank CAPES, CNPq and FAPESP for financial support, and
M.P.A. thanks Johnson Matthey plc for the loan of RuCl3ꢀnH2O.
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