Synthesis and characterization of [Ru(η6-C 10H14)(dppf)X][PF6] (X = Cl, Br, I, SnF 3) compounds: The X-ray structure of [Ru(η6-C 10H14)(dppf)Cl][SnCl3]·0.45CH 2Cl2

Article abstract of DOI:10.1016/j.poly.2012.05.002

The arene-ruthenium complex [Ru(η⁶-C₁₀H ₁₄)(dppf)Cl]PF₆ (1) was used as a precursor for the syntheses of the [Ru(η⁶-C₁₀H₁₄)(dppf)Br] PF₆ (2), [Ru(η⁶-C₁₀H₁₄)(dppf)I] PF₆ (3), [Ru(η⁶-C₁₀H₁₄)(dppf) SnF₃]PF₆ (4) and [Ru(η⁶-C ₁₀H₁₄)(dppf)Cl][SnCl₃]·0.45CH ₂Cl₂ (5) complexes by its reactions with KBr, KI, SnF ₂ and SnCl₂, respectively. All of the compounds were characterized by NMR, IR, ⁵⁷Fe and ¹¹⁹Sn-Mo?ssbauer spectroscopy, and cyclic voltammetry. The single-crystal X-ray structure analysis of the [Ru(η⁶-C₁₀H₁₄)(dppf)Cl] [SnCl₃]·0.45CH₂Cl₂ complex revealed the expected piano-stool geometry. Cyclic voltammograms of the complexes showed only one quasi-reversible electrochemical process, involving the oxidation of Fe(II) and Ru(II) at the same potential, which was confirmed by exhaustive electrolysis experiments. ⁵⁷Fe-Mo?ssbauer parameters obtained for the complexes (1-5) were fitted with one doublet corresponding to a site of one iron(II). The ¹¹⁹Sn-Mo?ssbauer parameters of the complex (4) indicate that tin is tetra covalent.

Full text of DOI:10.1016/j.poly.2012.05.002

Polyhedron 42 (2012) 110–117
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Synthesis and characterization of [Ru(
compounds: The X-ray structure of [Ru(
g
6-C10H14)(dppf)X][PF6] (X = Cl, Br, I, SnF3)
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2
Lilian A. Paim a, Fabrícia M. Dias a, Helmuth G.L. Siebald a, , Javier Ellena , José D. Ardisson ,
b
c
⇑
Monize M. da Silva d, Alzir A. Batista d,
⇑
a Laboratório de Química de Coordenação e Organometálica, Departamento de Química, Universidade Federal de Minas Gerais, Belo Horizonte-MG, CEP 31270-901, Brazil
b Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos-SP, CP 369, CEP 13560-970, Brazil
c Laboratório de Física Aplicada CDTN/CNEN, Belo Horizonte-MG, CEP 31270-010, Brazil
d Departamento de Química, Universidade Federal de São Carlos-SP, CEP 13565-905, Brazil
a r t i c l e i n f o
a b s t r a c t
The arene–ruthenium complex [Ru(g
6-C10H14)(dppf)Cl]PF6 (1) was used as a precursor for the syntheses of
Article history:
the [Ru(
g g g
6-C10H14)(dppf)Br]PF6 (2), [Ru( 6-C10H14)(dppf)I]PF6 (3), [Ru( 6-C10H14)(dppf)SnF3]PF6 (4) and
Received 26 December 2011
Accepted 4 May 2012
Available online 15 May 2012
[Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5) complexes by its reactions with KBr, KI, SnF2 and SnCl2,
respectively. All of the compounds were characterized by NMR, IR, 57Fe and 119Sn-Mössbauer spectroscopy,
and cyclic voltammetry. The single-crystal X-ray structure analysis of the [Ru(g
6-C10H14)(dppf)Cl]
Keywords:
[SnCl3]ꢀ0.45CH2Cl2 complex revealed the expected piano-stool geometry. Cyclic voltammograms of the
complexes showed only one quasi-reversible electrochemical process, involving the oxidation of Fe(II)
and Ru(II) at the same potential, which was confirmed by exhaustive electrolysis experiments. 57Fe-
Mössbauer parameters obtained for the complexes (1–5) were fitted with one doublet corresponding to
a site of one iron(II). The 119Sn-Mössbauer parameters of the complex (4) indicate that tin is tetra covalent.
Ó 2012 Elsevier Ltd. All rights reserved.
Heterobimetallic complexes
Arene–ruthenium
1,10-Bis(diphenylphosphino)ferrocene
Mössbauer
Electrochemistry
1. Introduction
diversity of structure and properties for its complexes [19–
22,34–38].
Organometallic ruthenium(II) complexes of the general formula
[Ru(
6-arene)2]2+ were published for the first time in 1957, and
The compound [Ru(
p-cymene, was synthesized initially by Jensen and coworkers [39]
by the reaction between the recursor [Ru(
6-C10H14)(CH3CN)2Cl]PF6
and the dppf ligand. In this work, between the precursor [Ru(g6
g g =
6-C10H14)(dppf)Cl]PF6, where 6-C10H14
g
there has been much interest in the chemistry of half-sandwich
ruthenium(II) arene complexes, mainly after the discovery that this
class of compounds has anti-tumor properties [1–3]. These
complexes also show excellent potential applications in catalytic
processes, such as small-molecule activation, molecule-based sen-
sors [4–7], addition of carboxylic acids to alkynes [8], hydrogenation
of olefins, ketones and arenes [9] and double-bond isomerization
[10]. Studies show that ruthenium(II) arene complexes of the type
g
-
C
10H14)(PPh3)Cl2] and its reaction with the dppf ligand was used
for the synthesis of the complex [Ru(
g
6-C10H14)(dppf)Cl]PF6 in the
presence of an excess of NH4PF6 and under reflux in a mixture of
solvents (ethanol/benzene, 1:1). In this complex the ruthenium
ion is very stable in the oxidation state 2+, because the dppf and
the p-cymene are both good
p-acceptor ligands [37,38].
[(g
6-arene)RuII(XY)Z]+, where XY is a bidentate chelating ligand,
In this work, we present the syntheses of the [Ru(g6
-
and X is a good leaving group, exhibit cytotoxicity against several
cancer cell lines, including cisplatin-resistant cells [11–17].
C10H14)(dppf)X]PF6 complexes X = Cl, Br, I and SnF3 (1–4) and of
[Ru(g
6-C10H14)(dppf)Cl][SnCl3]ꢀ(5) (Scheme 1). These complexes
The 1,10-bis(diphenylphosphino)ferrocene (dppf) compound
was first reported in 1971, and since then, this metallocene-based
diphosphine has attracted much attention, and its chemistry is
well documented [18–22]. The interest in species containing dppf
is mainly focused on structural [23–28], catalytic [29–31] and
electrochemical [32,33] studies. This diphosphine is a very versa-
tile ligand because it can be coordinated to transition metals in a
cis-chelating, trans-spanning or bridging form, leading to a great
were characterized by NMR (1H and 31P{1H}), IR, 57Fe and 119Sn-
Mössbauer spectroscopies and electrochemistry. The [Ru(g6
-
C
10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 complex was also character-
ized by X-ray crystallography.
2. Experimental procedures
2.1. Materials, procedures and instrumentation
All manipulations were performed under purified argon or
nitrogen, using standard Schlenk techniques employing a vacuum
line or using a glove box. Reagent-grade solvents were appropri-
⇑
Corresponding authors. Tel./fax: +55 16 33518285.
E-mail addresses: hsiebald@ufmg.br (H.G.L. Siebald), daab@ufscar.br (A.A. Batista).
0277-5387/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.poly.2012.05.002

L.A. Paim et al. / Polyhedron 42 (2012) 110–117
111
electrolyte in a cell equipped with platinum working and auxiliary
electrodes and Ag/AgCl as the reference electrode. The half-wave
potentials for the reversible cyclic voltammetric processes were
estimated by the average of the anodic and cathodic peak poten-
tials (E1/2 = (Epa + Epc)/2).
(1) X = Cl, [PF6]
(2) X = Br, [PF6]
(3) X = I, [PF6]
Ru
X
[X]
Ph2P
PPh2
(4) X = SnF3, [PF6]
(5) X = Cl, [SnCl3]
2.2. X-ray structure determination of (5)
Fe
Single crystals of [Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2
suitable for X-ray structure analysis were obtained by recrystalli-
zation from dichloromethane/n-hexane (2:1). For the data collec-
tion and cell parameter determination, an Enraf–Nonius Kappa-
Scheme 1. Structures of complexes (1–5).
CCD diffractometer, with an Mo K
a radiation (k = 0.71073 Å) was
used. Data collection for the crystal at 293(2) K was performed
with the COLLECT program [40]; integration and scaling of the reflec-
tions were performed with the HKL Denzo-Scalepack system of
programs [41]. Absorption corrections were performed using the
multi-scan method [42]. The structure was solved by direct meth-
ods with the SHELXS-97 program [42]. The models were refined by
full-matrix least-squares on F2 with SHELXL-97 [41]. All of the hydro-
gen atoms were stereochemically positioned and refined with a
riding model (Table 1).
The crystal contains a severely disordered CH2CL2 solvent
molecule, which could not be modeled reliably by discrete atoms.
Correspondingly, the contribution of the disordered solvent was
subtracted from the diffraction data by the SQUEEZE procedure
[43] which showed a total solvent accessible area volume of
263.0 Å3. SQUEEZE calculations indicated the presence of 38eꢁ per
unit cell, which may be attributed to 0.45 molecules of CH2CL2 per
asymmetric unit.
Table 1
Crystal
data
and
structure
refinement
for
the
complex
[Ru(g6
-
C
10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5).
Empirical formula
Formula weight
Temperature (K)
Wavelength (Å)
Crystal system
Space group
Unit cell dimensions
a (Å)
[C44H42P2ClFeRu][SnCl3]ꢀ0.45CH2Cl2
1088.34
293(2)
0.71073
triclinic
ꢀ
P1
12.6047(2)
12.7856(2)
15.0975(2)
85.886(1)
73.376(1)
77.370(1)
2274.87(6)
2
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
Volume (Å3)
Z
Density (calculated) (Mg/m3)
Absorption coefficient (mmꢁ1
F(000)
1.589
1.575
1086
)
3. Synthesis
Crystal size (mm)
Theta range for data collection
Index ranges
0.32 ꢂ 0.27 ꢂ 0.10
3.27–27.55°
ꢁ16,16; ꢁ16, 16; ꢁ19, 19
20174
10335 [Rint = 0.0272]
98.3%
The starting complexes [RuCl2(
10H14)(PPh3)Cl2] were prepared following theliterature procedures
[44,45]. The complex [Ru(
6-C10H14)(dppf)Cl]PF6 was prepared
from the reaction between [Ru(
6-C10H14)(PPh3)Cl2], dppf (1:1),
g -
6-C10H14)]2 and [Ru(g6
Reflections collected
C
Independent reflections
Completeness to theta = 27.55°
Absorption correction
Maximum and minimum transmission 0.881 and 0.715
Refinement method
g
g
Gaussian
and excess of NH4PF6 under reflux in an EtOH/benzene (1:1) solu-
tion. This procedure was previously reported in the literature [39].
Experimental synthetic procedures, leading to the isolation of
previously unreported complexes, are described below.
full-matrix least-squares on F2
10335/0/481
1.064
R1 = 0.0390, wR2 = 0.1169
R1 = 0.0480, wR2 = 0.1218
0.576 and ꢁ0.766
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2
R indices (all data)
r
(I)]
Largest difference in peak and hole
3.1. [Ru(
g
6-C10H14)(dppf)Cl]PF6 (1)
(e Åꢁ3
)
To a Schlenk flask containing 0.4 g (0.7 mmol) of [Ru(g6
-
C10H14)(PPh3)Cl2] and 0.43 g (0.8 mmol) of dppf dissolved in 60 mL
of benzene, 1.1 g (6.5 mmol) of NH4PF6 dissolved in 50 mL of ethanol
was added. The resultant mixture was stirred and refluxed for 16 h,
under a dry N2 atmosphere. Afterward, the solvent was completely
removed under vacuum. The solid was re-dissolved in a minimum
volume of dichloromethane/ethanol (1:1) mixture and precipitated
by addition of n-hexane. The solid obtained was filtrated and
washed with n-hexane and recrystallized in a mixture of CH2Cl2
and n-hexane. Yield: 90%. M.p: 186–188 °C. Anal. Calc. for
ately distilled and dried prior to use. The NMR spectra were re-
corded at 400 MHz, 1H; 100.62 MHz, 13C{1H}; 50.29 MHz, 31P{1H}
and 148.97 MHz, 119Sn{1H}, using a Bruker DPX-400 spectrometer
equipped with an 89 mm wide-bore magnet. The 13C and 1H shifts
are reported relative to SiMe4. The 31P shifts are reported relative
to H3PO4, and the 119Sn shifts are reported relative to SnMe4.
119Sn and 57Fe-Mössbauer spectra were collected with samples
maintained at 77 K, using room-temperature sources of CaSnO3
and 57Co, respectively. All spectra were fitted using Lorentzian line
C
44H42P3FeRuClF6: C, 54.48; H, 4.36%. Found: C, 54.79; H, 4.46%. IR
(CsI): m , m m .
(Ru–Cl) 246 cmꢁ1 (Ru–P) 548 cmꢁ1 and (PF) 820 cmꢁ1
shapes. Calibration was performed with
aFe and CaSnO3. The infra-
1H NMR (CDCl3, 400.13 MHz), d 0.88 (d, 6H, (CH3)2, JH–H = 4.0 Hz),
0.96 (s, 3H, CH3), 2.63 (sept, 1H, CH(CH3)2, JH–H = 6.8 Hz), 4.07 (s,
2H, Cp–Fe), 4.26 (s, 2H, Cp–Fe), 4.35 (s, 2H, Cp–Fe), 5.06 (s, 2H, Cp–
red spectra were recorded with samples pressed as CsI pellets on a
Perkin–Elmer 283B spectrometer in the 4.000–200 cmꢁ1 range.
Carbon, nitrogen and hydrogen analyses were performed on a Per-
kin–Elmer PE-2400 CHN-analyser. Tin analyses were performed
using a Hitachi Z-8200 atomic absorption spectrophotometer (Sn
lamp, kmax = 224.6 nm, N2O/acetylene flame). Cyclic voltammetry
experiments were performed at room temperature with a BAS
100B/W MF-9063 potentiostat in a 10ꢁ3 M CH2Cl2 solution with
tetrabutylammonium perclorate (0.1 M) as the supporting
Fe), 5.14 (d, 2H,
g g
6-C6H4, JH–H = 6.16 Hz), 5.70 (sl, 2H, 6-C6H4,
JH–H = 5.8 Hz), 7.43–7.44 (m, 6H, Hpara and Hmeta, Ph), 7.57–7.58
(m, 8H, Hortho, Ph), 7.66–7.70 (m, 6H, Hpara and Hmeta, Ph); 13C{1H}
NMR (CDCl3, 400.13 MHz), d 15.50 (s, CH3), 20.80 (s, (CH3)2), 31.25
(s, CH(CH3)2), 69.27 (s, Cp–Fe), 73.86 (s, Cp–Fe), 74.93 (s, Cp–Fe),
1
78.76 (t, Cp–Fe, JC–P = 5 Hz), 83,90 (pt, Cp–Fe, JC–P = 28 Hz and
3JC–P = 27 Hz), 90.88 (s,
g g
6-C6H4), 96.35 (s, 6-C6H4), 99.45

112
L.A. Paim et al. / Polyhedron 42 (2012) 110–117
(s, CCH(CH3)2), 130.27 (s, CCH3), 128.67 (dt, Cmeta, Ph) 131.05
(s, Cpara, Ph), 133.23 (t, Cortho, Ph, 3JC–P = 5.0 Hz and 128.67 (s, Cmeta
atmosphere. The precipitate formed was filtrated and washed with
n-hexane and recrystallized in a mixture of CH2Cl2/n-hexane (2:1).
Yield: 62%. M.p. 190–192 °C. Anal. Calc. for C44H42P3FeSnF9Ru: C,
47.59; H, 3.81; Sn, 10.69%. Found: C, 47.68; H, 3.91; Sn, 10.94%.
,
3
5
Ph), 135.32 (t, Cortho, Ph, JC–P = 6.0 Hz and JC–P = 5,0 Hz), 134.01
1
3
(pt, Cipso, Ph, JC–P = 25.0 Hz and JC–P = 24.0 Hz), 138.45 (pt, Cipso
,
Ph, 1JC–P = 25.0 Hz and 3JC–P = 24.0 Hz).
IR (CsI):
m
(Sn-F) 508 cmꢁ1
,
m
(Ru–P) 557 cmꢁ1 and
m(PF6)
835 cmꢁ1
.
1H NMR (CDCl3, 400.13 MHz), d 0.88 (d, 6H, (CH3)2)
3.2. [Ru(
g
6-C10H14)(dppf)Br]PF6 (2)
(JH–H = 6.8 Hz), 0.97 (s, 3H, CH3), 2.63 (sept, 1H, CH(CH3)2), 4.07
(s, 2H, Cp–Fe), 4.20 (s, 2H, Cp–Fe), 4.35 (s, 2H, Cp–Fe), 5.06 (s,
To a Schlenk flask containing 0.3 g (0.3 mmol) of [Ru(g6
-
2H, Cp–Fe), 5.14 (d, 2H, g g
6-C6H4), 5.69 (d, 2H, 6-C6H4), 7.44 (sl,
C
10H14)(dppf)Cl][PF6] dissolved in 6 mL of benzene, 0.4 g
6H, Hpara and Hmeta, Ph), 7.57–7.58 (sl, 8H, Hortho, Ph), 7.68–7.70
(sl, 6H, Hpara and Hmeta, Ph); 13C{1H} NMR (CDCl3, 400.13 MHz), d
14.59 (s, CH3), 20.57 (s, (CH3)2), 30.99 (s, CH(CH3)2), 69.02 (s, Cp–
(3.1 mmol) of KBr dissolved in 40 mL of ethanol was added. The
resultant mixture was stirred and refluxed for 9 h under a dry N2
atmosphere. Afterward, the solvent was completely removed under
vacuum. The solid was re-dissolved in a minimum volume of the
mixture of dichloromethane/ethanol (1:1) and precipitated by the
addition of n-hexane. The solid obtained was filtrated and washed
with n-hexane and recrystallized in a mixture of CH2Cl2/hex-
ane(2:1). Yield: 70%. M.p. 194–195 °C. Anal. Calc. for C44H42P3FeR-
uBrF6: C, 52.08; H, 4.17%. Found: C, 52.48; H, 4.35%. IR (CsI):
1
Fe), 73.60 (s, Cp–Fe), 74.68 (s, Cp–Fe), 78.51 (t, Cp–Fe, JC–P = 4.5
1
3
and 4.9 Hz), 83.65 (pt, Cp–Fe, JC–P = 28 Hz and JC–P = 27 Hz),
90.66 (s,
6-C6H4), 96.14 (s, 6-C6H4), 99.20 (s, CCH(CH3)2),
130.80 (s, CCH3), 129.22 (sl, Cmeta, Ph), 132.21 (s, Cpara, Ph),
g
g
2
4
132.95 (s, Cpara, Ph), 133.99 (t, Cortho, Ph, JC–P and JC–P = 4.5 and
2
4
4.4 Hz), 135.04 (t, Cortho, Ph, JC–P and JC–P = 5.3 and 5.2 Hz),
1
3
133.52 (pt, Cipso, Ph, JC–P = 24.8 Hz and JC–P = 24.0 Hz), 138.19
1
3
m
(Ru–Br) 252 cmꢁ1
,
m
(Ru–P) 557 cmꢁ1 and
m
(PF) 820 cmꢁ1
.
1H
(pt, Cipso, Ph, JC–P = 25.3 Hz and JC–P = 24.8 Hz); 31P{1H} NMR
NMR (CDCl3, 400.13 MHz), d 0.89 (d, 6H, (CH3)2, JH–H = 4.0 Hz),
0.99 (s, 3H, CH3), 2.66 (sept, 1H, CH(CH3)2, JH–H = 6.8 Hz), 4.06 (s,
2H, Cp–Fe), 4.26 (s, 2H, Cp–Fe), 4.35 (s, 2H, Cp–Fe), 5.06 (s, 2H,
(CDCl3, 161.98 MHz).
3.5. [Ru(
g
6-C10H14)(dppf)Cl][SnCl3] (5)
Cp–Fe), 5.15 (sl, 2H,
g g
6-C6H4), 5.74 (sl, 2H, 6-C6H4), 7.45 (m, 6H,
Hpara and Hmeta, Ph), 7.58 (m, 8H, Hortho, Ph), 7.70 (m, 6H, Hpara
and Hmeta, Ph); 13C{1H} NMR (CDCl3, 400.13 MHz), d 15.27 (s,
CH3), 20.86 (s, (CH3)2), 31.03 (s, CH(CH3)2), 69.08 (s, Cp–Fe), 73.65
To a Schlenk flask containing 0.3 g (0.3 mmol) of [Ru(g6
10H14)(dppf)Cl][PF6] dissolved in 8 mL of benzene.0.22 g
(1.0 mmol) of SnCl2ꢀ2H2O dissolved in 50 mL of ethanol was added.
The resultant solution was stirred and refluxed for 10 h under a dry
N2 atmosphere. The precipitate formed was separated by filtration,
washed with n-hexane and recrystallized in a mixture of CH2Cl2/n-
hexane (2:1). Yield: 78%. M.p. 195–197 °C. Anal. Calc. for
-
C
(s, Cp–Fe), 74), 96.50 (s,
CCH3), 128.60 (s, Cmeta, Ph), 130.87 (s, Cpara, Ph), 132.36 (s, Cpara
g
6-C6H4), 99.50 (s, CCH(CH3)2), 129.50 (s,
,
Ph), 133.17 (s, Cortho, Ph) 135.22 (t, Cortho, Ph), 133.82 (pt, Cipso, Ph,
3
1
1JC–P = 25.0 Hz and JC–P = 24.0 Hz), 138.24 (pt, Cipso, Ph, JC–P
=
25.0 Hz and 3JC–P = 24.0 Hz).
C
44H42P2Cl4FeRuSn: C, 51.32; H, 4.33; Sn, 11.30%. Found: C, 51.47;
H, 4.37; Sn, 11.54%. IR (CsI): (Sn–Cl)
(Ru–Cl) 227 cmꢁ1
245 cmꢁ1 and (Ru–P) 547 cmꢁ1 1H NMR (CDCl3, 400.13 MHz),
m
, m
3.3. [Ru(
g
6-C10H14)(dppf)I][PF6] (3)
m
.
0.89 (d, 6H, (CH3)2) (JH–H = 6.8 Hz), 1.00 (s, 3H, CH3), 2.66 (sept,
1H, CH(CH3)2), 4.08 (s, 2H, Cp–Fe), 4.27 (s, 2H, Cp–Fe), 4.35 (s, 2H,
Cp–Fe), 5.05 (s, 2H, Cp–Fe), 5.20 (d, 2H, C6H4), 5.79 (sl, 2H, C6H4),
7.45 (m, 6H, Hpara and Hmeta, Ph), 7.60 (m, 8H, Hortho, Ph), 7.70 (m,
6H, Hpara and Hmeta, Ph); 13C{1H} NMR (CDCl3, 400.13 MHz), d
14.88 (s, CH3), 20.62 (s, (CH3)2), 30.88 (s, CH(CH3)2), 69.06 (s, Cp–
To a Schlenk flask containing 0.3 g (0.3 mmol) of [Ru(g6
10H14)(dppf)Cl][PF6] dissolved in 40 mL of THF, 0.6 g (3.4 mmol)
-
C
of KI was added. The resultant mixture was stirred and refluxed
for 8 h under a dry N2 atmosphere. The solid formed was filtered
and washed with n-hexane and recrystallized in a minimum vol-
ume of the mixture of CH2Cl2/n-hexane (2:1). Yield: 61%. M.p.
198–199 °C. Anal. Calc. for C44H42P3FeRuIF6: C, 49.78; H, 3.98%.
1
Fe), 73.58 (s, Cp–Fe), 74.65 (s, Cp–Fe), 78.40 (t, Cp–Fe, JC–P = 4.5
1
3
and 5 Hz), 83.51 (pt, Cp–Fe, JC–P = 28 Hz and JC–P = 27 Hz), 90.67
(s,
6-C6H4), 96.22 (s, 6-C6H4), 99.95 (s, CCH(CH3)2), 132.15 (s,
CCH3), 130.23 (sl, Cmeta, Ph), 132.90 (s, Cpara, Ph), 132.99 (s, Cpara
Found: C, 50.05; H, 4.06%. IR (CsI and nujol):
m
(Ru–I) 163 cmꢁ1
1H NMR (CDCl3,
,
g
g
m
(Ru–P) 548 cmꢁ1 and (PF) 825 cmꢁ1
m
.
,
,
=
400.13 MHz) d 0.87 (d, 6H, (CH3)2, JH–H = 7.2 Hz), 1.02 (s, 3H, CH3),
2.63 (sept, 1H, CH(CH3)2, JH–H = 6.8 and 7.2 Hz), 4.04 (s, 2H, Cp–
Fe), 4.24 (s, 2H, Cp–Fe), 4.32 (s, 2H, Cp–Fe), 5.03 (s, 2H, Cp–Fe),
2
4
Ph), 133.97 (t, Cortho, Ph, JC–P and JC–P = 4.5 Hz), 135.06 (t, Cortho
2
4
1
Ph, JC–P and JC–P = 5.5 and 5.0 Hz), 134.95 (pt, Cipso, Ph, JC–P
3
1
24.8 Hz and JC–P = 24.0 Hz), 138.17 (pt, Cipso, Ph, JC–P = 25.3 Hz
5.17 (d, 2H,
g g =
6-C6H4, JH–H = 6.0 Hz), 5.83 (d, 2H, 6-C6H4, JH–H
and 3JC–P = 25 Hz).
5.6 Hz), 7.41–7.42 (m, 6H, Hpara and Hmeta, Ph), 7.56–7.58 (m, 8H,
Hortho, Ph), 7.66–7.69 (m, 6H, Hpara and Hmeta, Ph); 13C{1H} NMR
(CDCl3, 400.13 MHz), d 15.13 (s, CH3), 20.64 (s, (CH3)2), 30.98 (s,
CH(CH3)2), 69.03(s, Cp–Fe), 73.62 (s, Cp–Fe), 74.67 (s, Cp–Fe),
4. Results and discussion
1
3
78.50 (t, Cp–Fe, JC–P = 5 Hz), 83.61(pt, Cp–Fe, JC–P = 28 Hz and
The complex [Ru(
replacement of the PPh3 from the [Ru(g
g
6-C10H14)(dppf)Cl][PF6] was prepared by
6-C10H14)(PPh3)Cl2] com-
JC–P = 27 Hz), 90.66 (s,
g
6-C6H4), 96.28 (s, 6-C6H4), 99.04 (s,
g
CCH(CH3)2, 128.45 (s, CCH3), 128.47 (td, Cmeta, Ph, JC–P = 5.0 Hz),
plex by the addition of a stoichiometric amount of the correspond-
ing diphosphine in the presence of NH4PF6 dissolved in ethanol/
130.79 (s, Cpara, Ph), 132.21 (s, Cpara, Ph), 133.01 (t, Cortho, Ph)
(2JC–P = 6.0 Hz), 135.11 (t, Cortho, Ph, JC–P = 5.0 Hz), 133.52 (pt, Cipso
,
benzene. The precursor, [Ru(g
6-C10H14)(dppf)Cl][PF6], was then re-
1
3
1
Ph, JC–P = 25.0 Hz and JC–P = 24.0 Hz), 138.22 (pt, Cipso, Ph, JC–P
=
acted with KBr, KI, SnF2 or SnCl2 in the mixture ethanol/benzene,
resulting in two binuclear complexes (2–3) and one trinuclear
complex (4). The solid obtained from the reaction of the same pre-
cursor with SnCl2 presents the chlorine in the coordination sphere
of the ruthenium promoting only the replacement of the counter-
25.0 Hz and 3JC–P = 24.0 Hz).
3.4. [Ru(
g
6-C10H14)(dppf)(SnF3)][PF6] (4)
To a Schlenk flask containing 0.3 g (0.3 mmol) of [Ru(g6
-
ion PF6 from the complex, by the SnCl3ꢁ, as shown by the crystal
ꢁ
C
10H14)(dppf)Cl]PF6 dissolved in 5 mL of benzene, 0.2 g (1.0 mmol)
structure of the reaction product (Fig. 1). It is interesting to note
that in complex (4), the SnF3ꢁ is directly coordinated to the ruthe-
nium but not with SnCl3. This can be explained by the larger size of
of SnF2.2H2O dissolved in 75 mL of ethanol was added. The resul-
tant solution was stirred and refluxed for 10 h under a dry N2

L.A. Paim et al. / Polyhedron 42 (2012) 110–117
113
this ion compared with the fluorine ion, which makes it difficult to
coordinate to the ruthenium atom due to the high steric hindrance
provided by the SnCl3 group.
CDCl3 for H and Hb, respectively, which are moved to a lower field
a
(see experimental data) when it is coordinated to the Ru(II), indi-
cating that the rings of the dppf have less electron density. This re-
sult is reflected in the oxidation potential of the Fe(II) center, which
will be discussed below.
ꢁ
The IR spectra of the compounds (1–5) present characteristic
bands of Ru-X stretching (X = Cl, Br and I). The disappearance of
mRu–Cl at 246 cmꢁ1 from the precursor and the appearance of
mRu–Br and mRu–I at ca. 252 and 163 cmꢁ1, respectively, for com-
plexes (2–3) support the replacement of the chlorine from the pre-
cursor by bromine and iodine in these complexes. The mSn–F at ca.
508 cmꢁ1 is present in the IR spectrum of complex (4).
4.1. Crystal structure of [Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5)
The ORTEP [42] molecular structure of the [Ru(g6
-
C
10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 complex is shown in Fig. 1; se-
The 31P{1H} NMR spectra of all compounds showed a singlet,
indicating the equivalency of the phosphorus atoms of the dppf
lected data are presented in Table 3.
The compound (5) crystallizes with CH2Cl2 solvated in the unit
cell, probably originating from the preparation of the starting
ꢁ
ligand, and a septet at approximately ꢁ145.0 ppm due to the PF6
ꢁ
counterion, except for complex (5), in which this ion is absent.
The 31P{1H}-chemical shifts (Table 2) are essentially the same for
all of the complexes, indicating that the magnetic properties of
the phosphorus atoms are not practically affected by replacing
Clꢁ with Brꢁ, Iꢁ or by SnF3ꢁ. Compounds (1–5) showed chemical
shift values (Table 2) at a slightly higher field than compound
material, and it shows the PF6 ion replacement by SnCl3ꢁ. The
geometry around the ruthenium centers can be defined as slightly
distorted octahedral, exhibiting the typical ‘‘piano–stool’’, with
three sites occupied by the p-cymene ligand and the remaining
three sites occupied by two phosphorus atoms and one chlorine.
The bond lengths are Ru–C(1) [2.310(3) Å], Ru–C(2) [2.238(3) Å],
Ru–C(3) [2.286(3) Å], Ru–C(4) [2.323(2) Å], Ru–C(5) [2.258(3) Å
and Ru–C(6) [2.244(3) Å] [Ru–C(p-cym) = 2.276(3) Å average].
The Ru–P(1) distance [2.3734(7) Å] is slightly longer than the
Ru–P(2) distance [2.3381(7) Å], which may be due to steric con-
straints of the bulky dppf group not allowing the symmetrical ap-
proach of this ligand toward the metal. The Ru–Cl bond length for
complex (5) [2.3868(7) Å] is slightly shorter than that found for the
[Ru(g -
5-Cp)(dppf)Cl] (d 46.1 ppm) [46]. Considering that the g5
Cp is a better donor ligand than the p-cymene, it is possible that this
observation is a consequence of the competitive effect between the
two good
p acceptor ligands (dppf and p-cymene) and the electrons
of the Ru(II) [47,48].
The 119Sn{1H} NMR results for complex [Ru( 6-C10H14
g )
(dppf)(SnF3)][PF6] show one multiplet at d ꢁ327.41 ppm due to
19
coupling of the Sn with fluorine (J119
F = 2.692,43 Hz). The
[Ru(
g
5-Cp)(dppf)Cl] complex [2.4446(12) Å] [46,52], suggesting a
Snꢁ
119Sn chemical shift in this compound is greatly affected by an
anomalous contribution to the Sn(II) center. To counterbalance
the strong electronic withdraw effect of the fluorine atom the Sn
center is forced to form a -backbond with the Ru atom, which in-
creases the shielding effect on the 119Sn nucleus [50]. The [Ru(g6
stronger bond in the complex (5) when compared with the g5
-
p
Cp complex. Because of the smaller electron density on the ruthe-
nium center in complex (5), the negatively charged chloride ligand
is bound strongly. The tin atom is coordinated to the chlorine
atoms with bond lengths Sn–Cl(2) [2.4844(10) Å], Sn–Cl(3)
[2.4616(12) Å], Sn–Cl(4) [2.4917(12) Å]. Given the bond distances
provided the pair with Sn–Cl 2.4917(12) Å and 2.4844(10) Å do
p
-
C
10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 complex shows only a singlet
with d ꢁ39.04 ppm, assigned to the tin atom, not coordinated to
the ruthenium center.
not overlap at 3
r
, so in actuality all three Sn–Cl distances are sta-
ꢁ
The Cp of the dppf molecule normally displays two signals in its
1H NMR spectra, corresponding to a AA, BB system (integral 4:4),
and its 13C NMR spectrum shows three signals, of C , Cb and C
tistically different. The SnCl3 specie has ideally C3 geometry, and
the normal mode analysis shows two Sn–Cl stretching of free
SnCl3ꢁ ion, 298 cmꢁ1 (A1) and 245 cmꢁ1 (E) [49]. The observed an-
gles Cl(2)–Sn–Cl(3) [95.00(4)°], Cl(3)–Sn–Cl(4) [92.55(5)°], Cl(2)–
Sn–Cl(4) [94.87(4)°] are similar to those detected for the species
a
c
(2:4:4). Upon coordination of the dppf with the ‘‘Ru(g6
-
C10H14)X’’ fragment (X = Cl, Br, I and SnF3), there is a broadening
of the resonance signals in the NMR spectra of both nuclei (1H
and 13C), and a remarkable change in the multiplicity of the H
and C signals for both Cp components of the dppf is observed. This
broadening in the signals may be caused by a subtle variation of
the electronic balance at each Cp ring, caused by the slight differ-
ence in the chemical environment of each P atom [46]. The p-cym-
ene ring signals are well resolved and exhibit only H–H coupling. In
the 13C{1H} NMR, seven signals were observed for the p-cymene
ring, as found in other ruthenium complexes analogs [44,45].
[Ru(
g
5-Cp)(PPh3)2(SnCl3)] [50]. It is noteworthy that in this case
ꢁ
the SnCl3 is not coordinated to the ruthenium atom but acts as
a counter ion.
4.2. Cyclic voltammetry
The data from the cyclic voltammograms of complexes (1–5), in
CH2Cl2 solutions and at room temperature, are in Table 4. It is
interesting to note that all five of the complexes present only
one oxidation process, at approximately 900 mV, and there is no
other process in the range from zero to 1800 mV. In our previous
The ability of the p-cymene ring to stabilize Ru(II) by p-acceptor
interactions is evident from the 1H NMR resonances of the com-
plexes [30,51]. Thus, the hydrogen resonance signals of the free
p-cymene ring at 7.15 and 7.25 ppm are shifted up field (to 4.60
and 4.72 ppm, respectively) when it is coordinated to the Ru(II)
paper involving the [Ru(g
5-Cp)(dppf)X] (X = Cl, Br, I and N3) com-
plexes, two well defined electrochemical processes were present.
In this case, the FeIII/FeII processes were near 600 mV, and the
RuIII/RuII processes were near 980 mV [46]. Considering that the
in the [RuCl2(g
6-C10H14)]2 complex, which increases the electron
density on the ring compared with the uncoordinated p-cymene
[44]. It is noteworthy that the protons of the p-cymene ring in
the compounds studied in this work (Table 2) are deshielded when
p-cymene is a p acceptor ligand and the cyclopentadienyl is a p do-
nor ligand, we would expect to see a higher potential than 980 mV
for the RuIII/RuII redox process in the present complexes according
compared with the corresponding starting dimer, [RuCl2(g6
-
to the general formula [Ru(g
6-C10H14)(dppf)X]+. However, this was
C10H14)]2. This is consistent with the reduced electron density on
not exactly observed in the cyclic voltammogram of these com-
the p-cymene ring after the introduction of the dppf ligand in the
plexes, at least regarding to the metal center of Fe(II). Thus, the
complex, indicating that this ligand (a good
p-acceptor species)
electrochemical behavior of the [Ru(
plexes can be rationalized in terms of a competitive effect where
two acceptor ligands (p-cymene and phosphorus atoms) are
g
6-C10H14)(dppf)X]+ com-
withdraws electron density from the Ru(II) center, making its back-
donation less intense when compared with the Ru(II) ion from the
p
precursor, [RuCl2(
g
6-C10H14)]2. Additionally, the chemical shifts for
mutually trans to each other and compete for the same electron
the protons in the free dppf ligand are at 3.99 and 4.24 ppm in
density of the metal center. In this case, the metal becomes rich

114
L.A. Paim et al. / Polyhedron 42 (2012) 110–117
Fig. 1. ORTEP view of the [Ru(
clarity.
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5) complex showing 50% probability ellipsoids. Hydrogen atoms and solvent have been omitted for
Table 2
1H, 31P{1H} and 119Sn{1H} NMR spectroscopic data for the complexes (1–5), in CDCl3, at RT.
Complexes
1H (
g
6-C6H4)
31P{1H}(dppf)
–
119Sn{1H}
–
Refs.
[43]
[RuCl2(
g
6-C10H14)]2
4.60
4.72
5.14
5.70
5.15
5.74
5.17
5.83
5.14
5.69
5.20
5.79
1
2
3
4
5
35.60
36.80
36.79
36.77
36.82
–
This work
This work
This work
This work
This work
–
–
ꢁ327.41 (SnF3)
ꢁ39.04 (SnCl3)
Table 3
Selected
Table 4
bond
lengths
and
angles
for
complex
[Ru(g6
-
Oxidation potentials of the complexes [Ru(
g
6-C10H14)(dppf)X][PF6] (where, X = Cl, Br,
C
10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5).
I and SnF3) (1–5) (mV).
Ru–C(1)
Ru–C(2)
Ru–C(3)
Ru–C(4)
Ru–C(5)
Ru–C(6)
Ru(p-cym)(avarage)
2.310(3)
2.238(3)
2.286(3)
2.323(3)
2.258(3)
2.244(3)
2.276(3)
Ru–Cl(1)
2.3868(7)
Complexes
RuIII/RuII/FeIII/FeII
Epaa
Sn–Cl(2)
Sn–Cl(3)
Sn–Cl(4)
Ru–P(1)
Ru–P(2)
2.4844(10)
2.4616(12)
2.4917(12)
2.3734(7)
2.3381(7)
Epcb
DE
1
2
3
4
5
860
900
880
921
861
710
720
730
828
711
150
180
150
93
150
Cl(3)–Sn–Cl(2)
Cl(3)–Sn–Cl(4)
Cl(2)–Sn–Cl(4)
P(2)–Ru–P(1)
P(2)–Ru–Cl(1)
P(1)–Ru–Cl(1)
95.00(4)
92.55(5)
94.87(4)
96.70(3)
87.22(2)
80.60(2)
C(1)–Ru–Cl(1)
C(2)–Ru–Cl(1)
C(3)–Ru–Cl(1)
C(4)–Ru–Cl(1)
C(5)–Ru–Cl(1)
C(6)–Ru–Cl(1)
162.12(8)
139.84(8)
105.12(7)
86.84(7)
97.36(8)
129.49(8)
a
Epa = oxidation potential.
Epc = reduction potential.
b
reasonable to suggest that involve the oxidation of both metals
at the same potential. In addition, the presence of two reduction
peaks, that are not well defined, in the cyclic voltammogram of
the [Ru(g
6-C10H14)(dppf)Br][PF6] complex (Fig. 3) supports this
in electron density, making the metal more easily oxidized, which
has also been observed by others [47,48]. Because only one process
idea. To confirm this suggestion, an exhaustive controlled potential
coulometry at 1100 V for the complexes showed that, in fact, two
electrons are involved in the oxidation processes.
appears in the cyclic voltammogram of the [Ru(
g )
6-C10H14
(dppf)X]+ complexes [as shown in Fig. 2 for complex (1)], it is

L.A. Paim et al. / Polyhedron 42 (2012) 110–117
115
1.00
0.0006
0.0004
0.0002
0.0000
-0.0002
0.95
(1)
1.00
0.99
(2)
0
200
400
600
800 1000 1200 1400 1600 1800
1.00
0.99
0.98
Potential. (mV)
6-C10H14)(dppf)Cl][PF6] (1) (scan
Fig. 2. Cyclic voltammograms of complex [Ru(
g
rate 100 mV/s, 0.1 mol Lꢁ1
,
PTBA, in CH2Cl2; reference electrode Ag/AgCl/Cl;
(3)
auxiliary and working electrodes Pt).
-6
-4
-2
0
2
4
6
Velocity (mm/s)
0.0010
0.0008
0.0006
0.0004
0.0002
0.0000
-0.0002
-0.0004
Fig. 4. 57Fe Mössbauer spectra at 77 K for [Ru( 6-C10H14)(dppf)Cl][PF6] (1), [Ru(g6
g
-
C
10H14)(dppf)Br][PF6] (2) and [Ru(
6-C10H14)(dppf)I][PF6] (3).
g
Table 5
57Fe and 119Sn-Mössbauer data at 77 K for the complexes [Ru( 6-C10H14
g )
(dppf)X][PF6] (X = Cl, Br,
0.45CH2Cl2 (5).
I
and SnF3) (1–4) and[Ru(
g
6-C10H14)(dppf)Cl] [SnCl3]ꢀ
Complexs 57Fe
119Sn
d
D
d
D
Area
(%)
U
U
a
(mm sꢁ1
)
(mm sꢁ1
)
(mm
(mm
(mm
(mm
b
sꢁ1
)
sꢁ1
)
sꢁ1
)
sꢁ1
)
1
2
3
4
0.51
0.49
0.49
0.48
2.33
2.25
2.26
2.25
0.34
0.39
0.37
0.38
–
–
–
3.25
0.01
3.23
–
–
–
1.93
0.64
1.93
–
–
–
30
70
100
–
–
–
0.97
0.99
0.93
0
200
400
600
800 1000 1200 1400 1600 1800 2000
Potential. (mV)
5
0.48
2.25
0.36
a
Relative to
aFe.
b
Relative to CaSnO3; 0.05 mm sꢁ1 for samples 1–5.
Fig. 3. Cyclic voltammograms of complex [Ru(
rate 100 mV/s, 0.1 mol Lꢁ1
PTBA, in CH2Cl2; reference electrode Ag/AgCl/Cl;
g
6-C10H14)(dppf)Br][PF6] (2) (scan
,
auxiliary and working electrodes Pt).
showed two sites, Fig. 5. The first site, d = 3.25 mm sꢁ1 (area 30%),
4.3. Mössbauer spectra
was greater than that of the complex, [Ru(g
5-Cp)(dppf)(SnF3)],
d = 1.48 mm sꢁ1, indicating that the density of the s electrons
around the nucleus of tin is higher for complex (4). This finding ap-
pears to confirm that the p-cymene ring is a more efficient donor of
The 57Fe-Mössbauer parameters for complexes (1–5) were fitted
with one doublet as shown in Fig. 4 for complexes (1–3) corre-
sponding to one iron(II) site in the same proportion but in very dif-
ferent environments (Table 5). It was observed the isomers shifts (d)
electron density than the (g
5-Cp) ring. Similar behavior was ob-
served in the 119Sn NMR spectrum. The second site has a low isomer
shift, d = 0.01 mm sꢁ1 (area 70%), which suggests a change of
hybridization in the tin atom to sp3, a s character of 25% d2sp3 in
the complex, and approximately 17% s character [58]. The observed
and quadrupole splitting (D) of the complexes although slightly dif-
ferent all fall within the range expected for dppf or ferrocene af-
fected by the coordination, varying between 0.48 and
0.51 mm sꢁ1. The coordination influence on the quadrupole split-
ting is more evident. The values now range from 2.25 to
2.33 mm sꢁ1, falling on the two sides with respect to the free ligand
D
values (Table 5) indicate a less pronounced breakdown in the
symmetry around the Sn when compared with [Ru(g5
Cp)(dppf)SnF3],
= 2,21 mm sꢁ1. Complex (4) is derived from a
-
D
dppf (
ferrocene value (
with the fact that the phosphine groups affect the
D
= 2.33 mm sꢁ1) [46,53–55], but remaining lower than the
= 2.42 mm sꢁ1) [56]. This behavior is consistent
-electron sys-
tin(II) species (SnX2) and the d value, indicating that the tin is
unmistakably tetra covalent [59]. This is explained by the dative
character of the Sn ? Ru bond, in which a Sn-based nonbonding
pair of electrons, originally present in SnX2, is shared by the two
metal centers upon formation of the metal-metal bond.
Complex (5) were fitted with one doublet, Fig. 5, and reveals a
number of interesting aspects. Initially, it should be noted that
the d of SnCl2 is high (d = 4.06 mm sꢁ1) [60], consistent with a high
density of s electrons at the tin nucleus (i.e., 33% s character assum-
D
p
tem of the ring without any significant disturbance on the electron
flux. This influence is maximized by the coplanarity of the rings
with the phosphorus atoms [57]. Therefore, the molecular symme-
try of the complexes around the iron center is strongly distorted.
Similar 57Fe Mössbauer spectra were obtained for complexes (4)
and (5). The 119Sn-Mössbauer parameters of complex (4) (Table 5)

116
L.A. Paim et al. / Polyhedron 42 (2012) 110–117
Acknowledgements
We thank CNPq (Conselho Nacional de Desenvolvimento Cientí-
1.00
0.99
fico e Tecnológico), FAPESP (Fundação de Amparo à Pesquisa do
Estado de São Paulo), CAPES (Coordenação de Pessoal de Nível
Superior) and FAPEMIG (Fundação de Amparo à Pesquisa do Estado
de Minas Gerais) for financial support.
(4)
Appendix A. Supplementary data
Crystallographic data for the structural analysis for the complex
[Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 discussed herein have
been deposited at the Cambridge Crystallographic Data Centre,
12 Union Road, Cambridge, CB2 1EZ, UK, and are available on re-
quest quoting the deposition number CCDC 850290. These supple-
mentary data can be obtained free of charge via http://
www.ccdc.cam.ac.uk/conts/retrieving.html.
1.00
0.99
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.poly.2012.05.002.
(5)
References
[1] E.O. Fischer, R.Z. Böttcher, Anorg. Allgem. Chem. 291 (1957) 305.
[2] C.G. Hamaker, D.P. Halbach, Inorg. Chim. Acta 359 (2006) 846.
[3] L.D. Dale, J.H. Tocher, T.M. Dayson, D.I. Edwards, D.A. Tocher, Anti-Cancer Drug
Des. 7 (1992) 3.
[4] M.A. Bennett, A.K. Smith, J. Chem. Soc., Dalton Trans. (1974) 233.
[5] A.M. Pizarro, M. Melchart, A. Habtemariam, L. Salassa, F.P.A. Fabbiani, S.
Parsons, P.J. Sadler, Inorg. Chem. 49 (2010) 3310.
[6] P. Govindaswamy, Y.A. Mozharivskyj, M.R. Kollipara, J. Organomet. Chem. 689
(2004) 3265.
[7] R. Cerón-Camacho, V. Gómez-Benítez, R.L. Lagadec, D. Morales-Morales, R.A.
Toscano, J. Mol. Catal. A 247 (2006) 124.
-6
-4
-2
0
2
4
6
Velocity (mm/s)
Fig. 5. 119Sn Mössbauer spectrum at 77 K for [Ru( 6-C10H14)(dppf)SnF3][PF6] (4)
g
and [Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2 (5).
[8] A. Dorcier, P.J. Dyson, C. Gossens, U. Rothlisberger, R. Scopelliti, I. Tavernelli,
Organometallics 24 (2005) 2114.
[9] D.J. Morris, A.M. Hayes, M. Wills, J. Org. Chem. 71 (2006) 7035.
[10] A. Habtemariam, M. Melchart, R. Fernandez, S. Parsons, I.D.H. Oswald, A.
Parkin, F.P.A. Fabbiani, J.E. Davidson, A. Dawson, R.E. Aird, D.I. Jodrell, P.J.
Sadler, J. Med. Chem. 49 (2006) 6858.
[11] S.H. van Rijt, A.F.A. Peacock, R.D.L. Johnstone, S. Parsons, P.J. Sadler, Inorg.
Chem. 48 (2009) 1753.
[12] M.J. Clarke, Coord. Chem. Rev. 236 (2003) 209.
ing a sp2 hybridization). In forming the species SnCl3ꢁ, as shown in
compound (5), there is
a decrease in the isomer shift to
d = 3.23 mm sꢁ1, consistent with the re-hybridization suffered by
the tin atom and the presence of three electronegative chloride li-
ꢁ
gands. It should be noted that the SnCl3 group in compound (5)
acts as counter-ion, and the M-Sn bond does not form.
[13] T. Bugarcic, A. Habtemariam, J. Stepankova, P. Heringova, J. Kasparkova, R.J.
Deeth, R.D.L. Johnstone, A. Prescimone, A. Parkin, S. Parsons, V. Brabec, P.J.
Sadler, Inorg. Chem. 47 (2010) 11470.
[14] L.K. Filak, G. Muhlgassner, F. Bacher, A. Roller, M. Galanski, M.A. Jakupec, B.K.
Keppler, V.B. Arion, Organometallics 30 (2010) 273.
5. Conclusions
[15] Y. Fu, A. Habtemariam, A.M. Pizarro, S.H. van Rijt, D.J. Healey, P.A. Cooper, S.D.
Shnyder, G.J. Clarkson, J.P. Sadler, J. Med. Chem. 53 (2010) 8192.
[16] C. Scolaro, A. Bergamo, L. Brescacin, R. Delfino, M. Cocchietto, G. Laurenczy, T.J.
Geldbach, G. Sava, P.J. Dyson, J. Med. Chem. 48 (2005) 4161.
[17] G. Gasser, I. Ott, N. Metzler-Nolte, J. Med. Chem. 54 (2011) 3.
[18] J.J. Bishop, A. Davison, M.L. Katcher, D.W. Lichtenberg, R.E. Merril, J.C. Smart, J.
Organomet. Chem. 27 (1971) 241.
[19] G. Bandoli, A. Dolmella, Coord. Chem. Rev. 209 (2000) 161.
[20] C. Sanchis, H.J. Salavagione, E. Morallon, J. Electroanal. Chem. 618 (2008) 67.
[21] W. Kaim, T. Sixt, M. Weber, J. Fiedler, J. Organomet. Chem. 637 (2001) 167.
[22] T. Togni, T. Hayashi, Ferrocenes, VCH, Weinheim, 1995.
[23] Y. Wang, E.I. Rogers, R.G. Compton, J. Electroanal. Chem. 648 (2010) 15.
[24] T.A. Peganova, N.V. Vologdin, P.V. Petrovskii, I.D. Nesterov, K.A. Lyssenko, O.V.
Gusev, Russ. Chem. Bull. 55 (2006) 683.
[25] L.F. Tang, W.L. Jia, Z.H. Wang, J.F. Chai, J.T. Wang, J. Organomet. Chem. 637
(2001) 209.
[26] X.L. Lu, S.Y. Ng, J.J. Vittal, G.K. Tan, L.Y. Goh, T.S.A. Hor, J. Organomet. Chem. 688
(2003) 100.
[27] L.R. Dinelli, G.V. Poelhsitz, E.D. Castellano, J. Ellena, A.A. Batista, Inorg. Chem.
48 (2009) 4692.
[28] C.A. Vock, C. Scolaro, A.D. Phillips, R. Scopelliti, G. Sava, P.J. Dyson, J. Med.
Chem. 49 (2006) 5552.
[29] B. Therrien, Coord. Chem. Rev. 253 (2010) 493.
[30] V. Cadierno, P. Crochet, J. Diez, S.E. Garcia-Garrido, J. Gimeno, Organometallics
22 (2003) 5226.
[31] V. Cadierno, P. Crochet, J. Diez, S.E. Garcia-Garrido, J. Gimeno, Organometallics
23 (2004) 4836.
[32] B. Therrien, L. Vieille-Petit, J. Jeanneret-Gris, P. Stepnicka, G. Suss-Fink, J.
Organomet. Chem. 689 (2004) 2456.
[33] T. Sixt, J. Fiedler, W. Kaim, Inorg. Chem. Commun. 3 (2000) 80.
[34] G. Von Poelhsitz, A.L. Bogado, M.P. de Araújo, H.S. Selistre-de-Araújo, J. Ellena,
E.E. Castellano, A.A. Batista, Polyhedron 26 (2007) 4707.
It was shown that the reactions of the precursor [Ru(g6
10H14)(dppf)Cl][PF6] (1) with the ionic species KBr, KI, SnF2 and
-
C
SnCl2 produce new arene–ruthenium complexes: [Ru(
g
6-C10H14
6-C10H14
)
)
(dppf)Br][PF6] (2), [Ru(
(dppf)SnF3][PF6] (4) and [Ru(
g
6-C10H14)(dppf)I][PF6] (3), [Ru(
g
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2
(5), respectively. The 57Fe-Mössbauer parameters for the complexes
(1–5), including those for the free dppf ligand are very similar and
show one doublet corresponding to one iron site. The 119Sn-
Mössbauer parameters of complex (4) indicate that the density of
s electrons around the nucleus of the tin is high and that there is a
less pronounced breakdown in the symmetry around the Sn. In
forming the species SnCl3ꢁ in compound (5), the tin atom suffered
re-hybridization, (i.e., 25% s character if it has taken a sp3
hybridization).
The X-ray structure of [Ru(
g
6-C10H14)(dppf)Cl][SnCl3]ꢀ0.45CH2Cl2
wasdetermined,confirming thenon-coordinationoftheSnCl3ꢁ tothe
ruthenium center. The 1H NMR data show that the protons of the
p-cymene ring are more deshielded in the complexes (1–5) than in
the dimer [Ru(g
6-C10H14)Cl2]2, suggesting a reduced electron den-
sity in the p-cymene ring after complexation with the dppf ligand.
The cyclic voltammetry data of the complexes show a single electro-
chemical process signed to the oxidation of both the Ru(II) and Fe(II)
metal centers. This suggestion was confirmed by exhaustive
electrolysis experiments.

L.A. Paim et al. / Polyhedron 42 (2012) 110–117
117
[35] T.F. Gallatti, A.L. Bogado, G. Von Poelhsitz, J. Ellena, E.E. Castellano, A.A. Batista,
M.P. de Araújo, J. Organomet. Chem. 692 (2007) 5447.
[36] T. Sixt, M. Sieger, M.J. Krafft, D. Bubrin, J. Fiedler, W. Kaim, Organometallics 29
(2010) 5511.
[37] T. Bugarcic, A. Habtemariam, R.J. Deeth, F.P.A. Fabbiani, S. Parsons, P.J. Sadler,
Inorg. Chem. 48 (2009) 9444.
[38] S.J. Dougan, M. Melchart, A. Habtemariam, S. Parsons, P.J. Sadler, Inorg. Chem.
45 (2006) 10882.
[39] S.B. Jensen, S.J. Rodger, M.D. Spicer, J. Organomet. Chem. 556 (1998) 151.
[40] G.M. Sheldrick, SHELXS-97, Program for Crystal Structure Resolution, Univ. of
Göttingen, Germany, 1997.
[48] A.A. Batista, L.R.V. Olmo, M.R.M. Fontes, G. Oliva, J. Braz. Chem. Soc. 7 (1996)
257.
[49] D.F. Shriver, M.P. Johnson, Inorg. Chem. 6 (1967) 1265.
[50] E.M. Moura, H.G.L. Siebald, G.M. Lima, Polyhedron 21 (2002) 2323.
[51] M.A. Bennett, M.J.I. Brines, J. Kovacik, J. Organomet. Chem. 689 (2004) 4463.
[52] X.L. Lu, J.J. Vittal, E.R.T. Tiekink, G.K. Tan, S.L. Kuan, L.Y. Goh, T.S.A. Hor, J.
Organomet. Chem. 689 (2004) 1978.
[53] A. Houlton, P.T. Bishop, R.M.G. Roberts, J. Silver, J. Organomet. Chem. 364
(1989) 381.
[54] A. Houlton, J.R. Miller, R.M.G. Roberts, J. Silver, J. Chem. Soc., Dalton Trans. 7
(1990) 2181.
[41] G.M. Sheldrick, SHELXL-97, Program for Crystal Structures Analysis, Univ. of
Göttingen, Germany, 1997.
[55] L. Korecz, H. Abou, G. Ortaggi, M. Graziani, U. Belluco, K. Burguer, Inorg. Chim.
Acta 9 (1974) 209.
[42] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565.
[43] P. Van der Sluis, A.L. Spek, Acta Crystallogr., Sect. A 46 (1990) 194.
[44] M.A. Bennett, T.N. Huang, T.W. Matheson, A.K. Smith, Inorg. Synth. 21 (1982)
74.
[56] A.E. Gerbase, E.J.S. Vichi, E. Stein, L. Amaral, A. Vasquez, M. Horner, C.M.
Mossmer, Inorg. Chim. Acta 266 (1997) 19.
[57] B. Corain, B. Longato, G. Fávero, Inorg. Chim. Acta 157 (1989) 259.
[58] C.A.L. Filgueira, Quim. Nova 21 (1998) 176.
[45] Y. Yamamoto, F. Miyauchi, Inorg. Chim. Acta 334 (2002) 77.
[46] L.A. Paim, A.A. Batista, F.M. Dias, C.C. Golfeto, J. Ellena, H.G.L. Siebald, J.D.
Ardisson, Trans. Met. Chem. 34 (2009) 949.
[47] E.B. Milosavljevic, E.B. Lj. Solujic’, E.B. Milosavljevic, E.B. Milosavljevic,
Organometallics 27 (1988) 4294.
[59] E.M. Moura, V.R. Terra, H.G.L. Siebald, L.A. Paim, F.M. Dias, Trans. Met. Chem.
28 (2003) 437.
[60] W.M. Teles, N.G. Fernandes, A. Abras, C.A.L. Filgueiras, Trans. Met. Chem. 24
(1999) 321.