Dinuclear ruthenium complexes containing tripodal dithiophosphonate ligands

Article abstract of DOI:10.1016/j.ica.2011.08.044

Treatment of [(η⁶-p-cymene)RuCl(μ-Cl)]₂ with Lawesson's reagent [ArP(S)(μ-S)]₂ (Ar = p-C₆H ₄OMe) in the presence of ammonium hydroxide afforded the dinuclear complex [(η⁶-p-cymene)Ru{μ-η¹(S), η²(S,S′)-ArP(O)S₂}]₂ (1) in which the tripodal [ArP(O)S₂]^2- ligands bind to the ruthenium atom in both bridging and chelating modes with two non-coordinating PO groups. Interaction of [RuHCl(CO)(PPh₃)₃] with [ArP(S)(μ-S)]₂ and bis(diphenylphosphino)methane (dppm) in the presence of ammonium hydroxide gave the dinuclear complex [Ru(CO) {μ₃-η¹(O),η²(S,S′)-ArP(O) S₂}(dppm)]₂ (2) in which the tripodal [ArPOS ₂]^2- ligands bind the two Ru atoms via both sulfur and oxygen atoms. Treatment of [Ru(PPh₃)₃Cl₂] with [ArP(S)(μ-S)]₂ at reflux in the presence of ammonium hydroxide led to the formation of the dinuclear mixed valence complex [Ru₂Cl ₂(μ-S){μ₃-η¹(O),η¹(S), -η²(S,S′)-ArP(O)S₂}(PPh₃) ₃] (3), which contains a [Ru^II(PPh₃) ₂Cl]⁺ and [Ru^IV(PPh₃)Cl] ³⁺ moieties by the tripodal [ArPOS₂]^2- ligand in a μ₃-η¹(O),η¹(S), η²(S,S′) coordination mode and the μ-S^2- anion. The crystal structures of 1, 2, and 3·CH₂Cl₂ along with their spectroscopic and electrochemical properties are reported.

Full text of DOI:10.1016/j.ica.2011.08.044

Inorganica Chimica Acta 378 (2011) 148–153
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Inorganica Chimica Acta
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Dinuclear ruthenium complexes containing tripodal dithiophosphonate ligands
Qing Ma a,b, Xi-Ying Wang b, Qun Chen a, Wa-Hung Leung c, Qian-Feng Zhang a,b,
⇑
a Department of Applied Chemistry, School of Petrochemical Engineering, Changzhou University, Jiangsu 213164, PR China
b Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Ma’anshan, Anhui 243002, PR China
c Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Treatment of [(
g
6-p-cymene)RuCl(
l
-Cl)]2 with Lawesson’s reagent [ArP(S)(
l
-S)]2 (Ar = p-C6H4OMe) in the
presence of ammonium hydroxide afforded the dinuclear complex [(
g
6-p-cymene)Ru{ 1(S),g2(S,S0)-
l-g
Received 14 February 2011
Received in revised form 16 August 2011
Accepted 23 August 2011
ArP(O)S2}]2 (1) in which the tripodal [ArP(O)S2]2ꢀ ligands bind to the ruthenium atom in both bridging
and chelating modes with two non-coordinating P@O groups. Interaction of [RuHCl(CO)(PPh3)3] with
Available online 10 September 2011
[ArP(S)(
gave the dinuclear complex [Ru(CO){l3
[ArPOS2]2ꢀ ligands bind the two Ru atoms via both sulfur and oxygen atoms. Treatment of [Ru(PPh3)3Cl2]
with [ArP(S)( -S)]2 at reflux in the presence of ammonium hydroxide led to the formation of the dinucle-
ar mixed valence complex [Ru2Cl2( -S){l3
1(O), 1(S),-g2(S,S0)-ArP(O)S2}(PPh3)3] (3), which contains a
l-S)]2 and bis(diphenylphosphino)methane (dppm) in the presence of ammonium hydroxide
-
g
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 (2) in which the tripodal
Keywords:
Ruthenium
l
Dithiophosphonate
Tripodal ligand
Synthesis
Crystal structure
Electrochemistry
l
-
g
g
[RuII(PPh3)2Cl]+ and [RuIV(PPh3)Cl]3+ moieties by the tripodal [ArPOS2]2ꢀ ligand in a l3 1(O), 1(S),g2(S,S0)
-g g
coordination mode and the
troscopic and electrochemical properties are reported.
l
-S2ꢀ anion. The crystal structures of 1, 2, and 3ꢁCH2Cl2 along with their spec-
Ó 2011 Elsevier B.V. All rights reserved.
1. Introduction
is not involved in coordination [26,27]. It has been noted that the
related thio ligands of the types [ArPS3]2ꢀ and [ArP(O)S2]2ꢀ are
found to coordinate copper and silver ions via both sulfur and oxy-
gen atoms [28,29]. The versatile bonding and structural features as
well as fascinating chemical reactivities of transition-metal
complexes have prompted us to make a systematic study of
ruthenium–dithiophosphonate complexes with the tripodal
[ArP(O)S2]2ꢀ ligands [23]. Here we report results of these efforts
and specially demonstrate three different coordination modes
There has been considerable current interest in the chemistry of
ruthenium–sulfur complexes, which is primarily due to their
industrial applications in hydrodesulfurization (HDS) and related
catalytic processes [1,2]. As the high catalytic activity of RuS2 in
various hydrotreating processes is directed by the sulfur-rich coor-
dination environment around the central metal ion, complexation
of ruthenium by thiolate ligands of selected types is of significant
importance [3]. As a part of this development, many examples of
ruthenium–sulfur complexes with thiolate ligands have been
reported [4,5]. Quite a few ruthenium complexes with 1,10-dithio
ligands have also isolated recently [6–8]. Although the phosphor-
1,10-dithio ligands with coinage metals such as copper [9–11], sil-
ver [12,13], gold [14–19], and nickel [20–22] are well documented,
very few ruthenium–dithiophosphonate complexes have been
reported to date [23]. The [ArPS2(OR)]ꢀ (Ar = p-CH3OC6H4, R = Me,
Et, i-Pr, and n-Pr) anions are normally generated from symmetrical
l-g
1(S),g2(S,S0) (A), l3
-
g
-g g
1(O),g2(S,S0) (B) and l3 1(O), 1(S),g2(S,S0)
(C), as shown in Chart 1, existing in the dinuclear ruthenium
complexes
[Ru(CO){l3
[(
g
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(O)S2}]2
l
-
g
(1),
-
g
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 (dppm = bis(diphen-
-S){l3
1(O), 1(S),
g2(S,S0)-ArP(O)S2}(PPh3)2] (3), respectively. The syntheses and
ylphosphino)methane) (2), and [Ru2Cl2(
-
l
-g
g
molecular structures of these ruthenium–dithiophosphonate
complexes along with their spectroscopic and electrochemical
properties are described in this paper.
bond cleavage of Lawesson’s reagent [ArP(S)(l-S)]2 in the presence
of corresponding sodium alkoxides [24,25]. As expected, the
[ArPS2(OR)]ꢀ as a phosphor-1,10-dithio ligand binds to metal ions
via the sulfur atoms of PS2 moiety whilst the introduced OR group
2. Experimental
2.1. General
All synthetic manipulations were carried out under dry nitrogen
by standard Schlenk techniques. Lawesson’s reagent, [ArP(S)(l-S)]2
(Ar = p-CH3OC6H4), and the ligand bis(diphenylphosphino)meth-
⇑
Corresponding author at: Department of Applied Chemistry, School of Petro-
chemical Engineering, Changzhou University, Jiangsu 213164, PR China. Tel./fax:
+86 555 2312041.
E-mail address: zhangqf@ahut.edu.cn (Q.-F. Zhang).
ane (dppm) were purchased from Aldrich and used without further
0020-1693/$ - see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2011.08.044

Q. Ma et al. / Inorganica Chimica Acta 378 (2011) 148–153
149
temperature. Yield: 79 mg, 54% (based on Ru). 1H NMR
(300 MHz, CDCl3): d ppm 3.64 (s, 4H, CH2), 3.74 (s, 6H, OCH3),
6.72 (d, 4H, J = 7.7 Hz, aryl H), 7.03–7.76 (m, 40H, Ph in dppm),
7.84–8.02 (dd, 4H, J = 7.7 Hz, aryl H). 31P{1H} NMR (121.5 MHz,
CDCl3): d ppm 14.7 (s, 4P, dppm), 58.6 (s, 2P, ArPS2O). Selected IR
(KBr, cmꢀ1): 1988 (vs), 1583 (s), 1435 (s), 1025 (s), 677 (s), 558
(s), 533 (m), 500 (s). MS (FAB): m/z 1463 [M+], 731 [½M+ꢀ1], 703
[½M+ꢀCOꢀ1]. Anal. Calc. for C66H58O6P6S4Ru22: C, 54.24; H, 3.99.
Found: C, 54.07; H, 3.95%.
OMe
OMe
OMe
P
S
P
S
P
S
O
O
O
S
S
S
Ru
Ru
Ru
Ru
Ru
Ru
2.4. Synthesis of [Ru2Cl2(
(PPh3)3]ꢁCH2Cl2 (3ꢁCH2Cl2)
l-S){l3-g g
1(O), 1(S),-g2(S,S0)-ArP(O)S2}-
(C)
(B)
(A)
Chart 1.
To a slurry of Lawesson’s reagent (41 mg, 0.10 mmol) and 17%
NH3ꢁH2O (0.2 mL) in THF (10 mL) was added solution of
a
[Ru(PPh3)3Cl2] (192 mg, 0.20 mmol) in THF (10 mL). The mixture
was stirred at reflux for 12 h. The solvent was removed in vacuo.
The solid residue was washed with hexane and further dissolved
in 10 mL CH2Cl2. The white solid was removed by the filtration.
The filtrate was carefully layered with hexane, blocky black crys-
tals of 3ꢁCH2Cl2 suitable for X-ray diffraction were obtained in a
week. Yield: 64 mg, 46% (based on Ru). 1H NMR (300 MHz, CDCl3):
d ppm 3.71 (s, 3H, OCH3), 5.32 (s, 2H, CH2Cl2), 6.73 (d, 2H,
J = 7.6 Hz, aryl H), 7.16–7.53 (m, 45H, PPh3), 7.81–8.06 (dd, 2H,
J = 7.8 Hz, aryl H). 31P{1H} NMR (121.5 MHz, CDCl3): d ppm 22.6
(d, J = 203 Hz, 2P, PPh3), 30.1 (s, 1P, PPh3), 43.4 (s, 1P, ArPS2O). Se-
lected IR (KBr, cmꢀ1): 1581 (s), 1430 (s), 1019 (s), 679 (s), 557 (s),
534 (m), 502 (s). MS (FAB): m/z 1310 [M+], 1275 [M+ꢀCl], 1240
[M+ꢀ2Cl]. Anal. Calc. for C61H52O2Cl2P4S3Ru2ꢁ (CH2Cl2): C, 53.34;
H, 3.90. Found: C, 52.71; H, 3.84%.
purification. [(
g
6-p-Cymene)RuCl(
l-Cl)]2 [30], [RuHCl(CO)(PPh3)3]
[31], and [Ru(PPh3)3Cl2] [32] were prepared according to the liter-
ature methods. NMR spectra were recorded on a Bruker ALX 300
spectrometer operating at 300 and 121.5 MHz for 1H and 31P,
respectively. Chemical shifts (d, ppm) were reported with reference
to SiMe4 (1H) and H3PO4 (31P). Infrared spectra (KBr) were recorded
on a Perkin-Elmer 16 PC FT-IR spectrophotometer with use of
pressed KBr pellets and positive FAB mass spectra were recorded
on a Finnigan TSQ 7000 spectrometer. Cyclic voltammetry was per-
formed with on a CHI 660 electrochemical analyzer. A standard
three-electrode cell was used with glassy carbon working elec-
trode, a platinum counter electrode and Ag/AgCl reference elec-
trode under an nitrogen atmosphere at 25 °C. Formal potentials
(Eo) were measured in CH2Cl2 solutions with 0.1 M [nBu4N]PF6 as
supporting electrolyte and reported with reference to the ferroce-
nium–ferrocene couple (Cp2Fe+/0). In the ꢀ0.5 to +1.2 V region, a
potential scan rate of 100 mV sꢀ1 was used. Elemental analyses
were carried out using a Perkin-Elmer 2400 CHN analyzer.
2.5. X-ray crystallography
A summary of crystallographic data and experimental details
for [(g l-g l-
6-p-cymene)-Ru{ 1(S),g2(S,S0)-ArP(O)S2}]2 (1), [Ru(CO){
2.2. Synthesis of [(g l-g
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(O)S2}]2 (1)
g
g
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 (2), and [Ru2Cl2( 1(O),
l-S){l3-g
1(S),-g2(S,S0)-ArP(O)S2}(PPh3)3]ꢁCH2Cl2 (3ꢁCH2Cl2) are summarized
To a slurry of Lawesson’s reagent (82 mg, 0.20 mmol) and 17%
NH3ꢁH2O (0.2 mL) in THF (10 mL) was added solution of
[( -Cl)]2 (108 mg, 0.20 mmol) in THF (10 mL).
6-p-cymene)RuCl(
in Table 1. Intensity data were collected on a Bruker SMART APEX
a
2000 CCD diffractometer using graphite-monochromated Mo K
a
g
l
radiation (k = 0.71073 Å) at 293(2) K. The collected frames were
processed with the software SAINT [33]. The data was corrected for
absorption using the program SADABS [34]. Structures were solved
by the direct methods and refined by full-matrix least-squares on
F2 using the SHELXTL software package [35,36]. All non-hydrogen
atoms were refined anisotropically. The positions of all hydrogen
atoms were generated geometrically (Csp3–H = 0.96 and Csp2–H =
0.93 Å), assigned isotropic thermal parameters, and allowed to ride
on their respective parent carbon or nitrogen atoms before the final
cycle of least-squares refinement.
The mixture was stirred for 4 h at room temperature. The solvent
was removed in vacuo. The solid residue was washed with hexane
and further dissolved in 10 mL CH2Cl2. The white solid was
removed by the filtration. The filtrate was carefully layered with
hexane, needle red crystals of 1 suitable for X-ray diffraction were
obtained in four days. Yield: 93 mg, 51% (based on Ru). 1H NMR
(300 MHz, CDCl3): d ppm) 1.32 (d, 6H, CH(CH3)2), 2.14 (s, 3H,
PhCH3), 3.01 (septet, 1H, CH(CH3)2), 3.72 (s, 6H, OCH3), 5.42 and
5.69 (dd, 4H, J = 8.2 Hz, aryl H in cymene), 6.82 (d, 4H, J = 7.8 Hz,
aryl H), 7.75–7.97 (dd, 4H, J = 7.9 Hz, aryl H). 31P{1H} NMR
(121.5 MHz, CDCl3): d (ppm) 63.5 (s). Selected IR (KBr, cmꢀ1):
1585 (s), 1430 (s), 1244 (s), 689 (s), 556 (s), 531 (m), 503 (s). MS
(FAB): m/z 907 [M+], 455 [½M++1]. Anal. Calc. for C34H42O4P2S4Ru2:
C, 45.03; H, 4.67. Found: C, 44.74; H, 4.63%.
3. Results and discussion
Preliminary results showed that treatment of Lawesson’s re-
agent [ArP(S)(
l
-S)]2 with ammonium hydroxide (NH3ꢁH2O) in a
2.3. Synthesis of [Ru(CO){
l
-
g
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 (2)
THF solution resulted in a homogeneous solution [23]. Actually,
the [ArP(O)S2]2ꢀ as a major component exists in the solution in
the presence of base. Accordingly, reaction of the mixture with
the ruthenium starting materials led to the isolation of diruthe-
nium–dithiophosphonate complexes. The tripodal ligands bind to
the ruthenium atom in three different coordination modes (Chart
1 and Scheme 1).
To a slurry of Lawesson’s reagent (41 mg, 0.10 mmol) and 17%
NH3ꢁH2O (0.2 mL) in THF (10 mL) was added a solution of [RuHCl(-
CO)(PPh3)3] (190 mg, 0.20 mmol) in THF (10 mL). The mixture was
stirred for 1 h at room temperature and dppm (78 mg, 0.20 mmol)
was added, then the mixture was further stirred for additional 3 h.
The solvent was removed in vacuo. The solid residue was washed
with hexane and further dissolved in 10 mL CH2Cl2. The white solid
was removed by the filtration. The filtrate was carefully layered
with hexane, yellow crystalline solids of 2 in three days at room
It has been noted that treatment of [(
with [ArP(S)(
-S)]2 in the absence of NH3ꢁH2O at reflux afforded the
dinuclear complex [(
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(S)S2}]2
with two terminal P@S bonds [23]. However, reaction of [(
6-p-
g l-Cl)]2
6-p-cymene)RuCl(
l
g
l-g
g

150
Q. Ma et al. / Inorganica Chimica Acta 378 (2011) 148–153
Table 1
Crystallographic data and experimental details for [(
g
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(O)S2}]2 (1), [Ru(CO){l3 1(O),g2(S,S0)-
l-g -g
ArP(O)S2}(dppm)]2 (2), and [Ru2Cl2(
l
-S){l3
-g
1(O),
g
1(S),-g2(S,S0)-ArP(O)S2}(PPh3)2]ꢁCH2Cl2 (3ꢁCH2Cl2).
Compound
1
2
3ꢁCH2Cl2
Empirical formula
Formula weight
Crystal system
Unit cell dimensions
a (Å)
C34H42O4P2S4Ru2
907.00
monoclinic
C66H58O6P6S4Ru2
1463.32
triclinic
C62H54O2Cl4P4S3Ru2
1395.05
triclinic
12.0589(7)
10.5437(6)
14.8083(10)
11.1328(7)
11.6164(7)
14.5682(9)
75.517(1)
76.385(1)
61.430(1)
1587.09(17)
11.0054(1)
13.4004(2)
20.8159(3)
86.553(1)
79.733(1)
84.064(1)
3001.78(7)
b (Å)
c (Å)
a
(°)
b (°)
106.595(4)
c
(°)
V (Å3)
1804.38(19)
P21/n
ꢀ
ꢀ
Space group
P1
P1
Z
2
1
2
Dcalc (g cmꢀ3
T (K)
)
1.669
296(2)
920
1.531
296(2)
744
1.543
296(2)
1412
F(000)
l
(Mo K
a
) (mmꢀ1
)
1.194
0.810
0.935
Total reflections
Independent reflections
Parameters
16165
4106
212
22291
7267
380
42007
13809
695
Rint
0.0340
0.0329, 0.0729
0.0534, 0.0857
1.031
0.0288
0.0275, 0.0635
0.0347, 0.0673
1.043
0.0213
0.0325, 0.0796
0.0419, 0.0856
1.020
b
R1a, wR2 (I > 2
r(I))
R1, wR2 (all data)
Goodness-of-fit (GOF)on F2c
P
P
a
b
c
R1
=
||Fo| ꢀ |Fc||/ |Fo|.
P
P
2
2 1=2
wR2 ¼ ½ wðjF2oj ꢀ jFc2jÞ = wjF2oj ꢂ
.
P
GoF = [ w|Fo| ꢀ |Fc|)2/(Nobs ꢀ Nparam)]1/2
.
cymene)RuCl(
l
-Cl)]2 with [ArP(S(S)(
l
-S)]2 in the presence of
neutral dinuclear complex 3. Although the mechanism for the for-
mation of 3 has not been well elucidated, it seems likely that the
NH3ꢁH2O at room temperature gave analogous complex [(
g
6-p-
cymene)Ru{
l-
g
1(S),g2(S,S0)-ArP(O)S2}]2 (1) with two terminal
partly decomposition of [ArP(S)(l
-S)]2 at reflux to the S2ꢀ anion is
P@O bonds. The IR spectrum of 1 shows the
m
(P@O) and
m
(P–S)
involved. The oxidation of RuII to RuIV was probably caused by a
Ru disproportionation reaction under thermodynamic conditions
[38]. Complex 3 is not a Ru(III)–Ru(III) complex that should be para-
magnetic due to an anti-ferromagnetic coupling across the sulfido-
stretching vibrations at 1244 and 689 cmꢀ1, respectively. The
31P{1H} NMR spectrum of 1 in CDCl3 exhibited a single resonance
at d 63.5 ppm which obviously shifts upfield by the comparison of
analogous complex [(
g
6-p-cymene)Ru{
l
-
g
1(S),-g2(S,S0)-ArP(S)S2}]2
ligands. The identity of the
l3-bridging ligand (S1) can be assigned
with same structural type (84.1 ppm) [23]. The positive ion FAB
mass spectrum of 1 shows the molecular ions [M+] and [½M++1]
with the characteristic isotopic distribution patterns. As the previ-
as either sulfur or oxygen. However, the formulation of 3 as a l3
oxo complex will result in the structural refinement with higher R
value with unacceptable thermal parameters. The formulation of
-
ous report, interaction of [RuHCl(CO)(PPh3)3] with [ArP(S)(
in the presence of NH3ꢁH2O gave the dinuclear complex
[Ru(CO)(l3
1(O),g2(S,S0)-ArPOS2)(PPh3)2]2 [23] in which the PPh3
ligands were substituted by stronger -donor dppm ligands in
the present reaction, leading to isolation of a new dinuclear com-
plex [Ru(CO){l3
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 (2). The IR spec-
trum of 2 shows a strong absorption band at 1025 cmꢀ1 which is
assigned to the (P–O) vibration [37]. The absorption band at
677 cmꢀ1 may be due to the
(P–S) vibration bond. The (C„O)
l
-S)]2
3 as a l3-sulfide complex was further supported by microanalytic
and NMR analyses. Notwithstanding, we still puzzled why the
ruthenium(II) center could be bound to the hard oxygen atoms of
the tripodal [ArP(O)S2]2ꢀ ligand in 3. In the 31P{1H} NMR spectrum
of 3, two singlets at d 30.1 and 43.4 ppm were tentatively assigned
to [Ru(PPh3)Cl]3+ and [ArP(O)S2]2ꢀ moieties, respectively, one dou-
blet at d 22.6 ppm may be reasonably assigned to two phosphorous
atoms in the [Ru(PPh3)2Cl]+ fragment. The P–P coupling constant
was determined to be J(31P,31P) = 203 Hz with a clear resolution of
the doublet signal. The FAB+ mass spectrum of complex 3 exhibits
molecular ions corresponding to [M+], [M+ꢀCl] and [M+ꢀ2Cl] with
the characteristic isotopic distribution patterns. Although the par-
ent molecular ions of complex 3 are detected at very low intensity,
a series of intense peaks assigned to ions which are formed by the
subsequent loss of the chloride ligands were observed.
-g
r
-
g
m
m
m
stretching vibration was found at 1988 cmꢀ1 in the IR spectrum
of 2 [37]. The 31P{1H} NMR spectrum of 2 in CDCl3 shows an intense
singlet at d 14.7 ppm and a weak singlet at d 58.6 ppm, assignable to
dppm and [ArP(O)S2]2ꢀ, respectively. The positive ion FAB mass
spectrum of 2 displays the expected peaks at m/z 1463, 731 and
703, corresponding to the molecular ions [M+], [½M+ꢀ1] and
[½M+ꢀCOꢀ1], respectively, with the characteristic isotopic distri-
bution patterns. Contrast to formation of the dinuclear com-
Complex 1 crystallized in the monoclinic space group P21/n, and
the molecular structure of 1 is illustrated in Fig. 1 and selected
bond lengths and angles are given in Table 2. The neutral complex
plex [Ru(
[Ru(PPh3)3Cl2] with [ArP(S)(
[23], treatment of [Ru(PPh3)3Cl2] with [ArP(S)(
THF followed by recrystallization from CH2Cl2/hexane gave air-
stable black crystals characterized as [Ru2Cl2( -S){l3
1(O), 1(S),-
g2(S,S0)-ArP(O)S2}(PPh3)3] (3). Two [Ru(PPh3)2Cl]+ and [Ru(PPh3)
l-
g
1(O),
g
2(S), g2(S,S0)-ArPOS2)(PPh3)2]2 from reaction of
-S)]2 in the presence of NH3ꢁH2O
-S)]2 at reflux in
l
1 comprises two [(g
6-p-cymene)Ru]2+ fragments bridged by the
l
sulfur atoms of two [ArP(O)S2]2ꢀ moieties with two non-coordina-
tive P@O groups. The molecular structure of 1 consists of discrete
dimeric molecules with distorted octahedral geometry around
the ruthenium atom, having a p-cymene ring at one face. One of
the sulfur atoms of the dithiophosphonato moiety is essentially
symmetrically bonded to two ruthenium atoms with distances
[Ru(1)–S(2) = 2.4169(8) and Ru(1)–S(2a) = 2.4227(8) Å, symmetric
l
-
g
g
Cl]3+ fragments were bridged by the tripodal [ArP(O)S2]2ꢀ and
l-
S2ꢀ ligands, indicative of the mixed-valence octahedral ruthe-
nium(II) and trigonal–bipyramidal ruthenium(IV) centers in the

Q. Ma et al. / Inorganica Chimica Acta 378 (2011) 148–153
151
O
P
Ar
S
S
Ru
Ru
S
S
P
S
S
S
Ar
Ar
O
P
P
Ar
1
S
(ii)
Ar
(i)
P
PPh
S
2
2
O
H C
S
2
CO
(iii)
S
Ar
P
Ru
Ph P
2
S
Ru
PPh
2
S
O
OC
S
O
CH
2
Ph P
2
P
(iv)
Ar
2
Ar
P
O
S
Cl
Ph P
S
S
PPh
3
Ru
Ru
3
Ph P
Cl
3
3
Scheme 1. Synthetic route for three diruthenium–dithiophosphonate complexes. Reagents and conditions: (i) NH3ꢁH2O, THF, rt; (ii) [(
g
6-p-cymene)RuCl(
l-Cl)]2, THF, rt; (iii)
[RuHCl(CO)(PPh3)3], dppm, THF, rt; (iv) [Ru(PPh3)3Cl2], THF, reflux.
Table 2
Selected bond lengths (Å) and angles (°) for [(
ArP(O)S2}]2 (1).
g l-g
6-p-cymene)Ru{ 1(S),g2(S,S0)-
Ru(1)–S(1)
Ru(1)–S(2)#1
P(1)–S(2)
2.4308(9)
2.4227(8)
2.1246(12)
Ru(1)–S(2)
P(1)–S(1)#1
P(1)–O(1)
2.4169(8)
2.0270(12)
1.488(2)
S(2)–Ru(1)–S(1)
85.46(3)
79.27(3)
86.72(4)
84.82(4)
117.26(11)
S(2)#1–Ru(1)–S(1)
Ru(1)–S(2)–Ru(1)#1
P(1)–S(2)–Ru(1)
S(1)#1–P(1)–S(2)
O(1)–P(1)–S(2)
81.21(3)
S(2)–Ru(1)–S(2)#1
P(1)#1–S(1)–Ru(1)
P(1)–S(2)–Ru(1)#1
O(1)–P(1)–S(1)#1
100.73(3)
106.93(4)
99.05(5)
117.18(11)
Symmetry transformations used to generate equivalent atoms: #1 ꢀx + 2, ꢀy, ꢀz.
two the sulfur atoms of the tripodal dithiophosphonato
[ArP(O)S2]2ꢀ ligands act as tri-coordinate atoms in both bridging
and chelating modes. The P–O bond length of 1.488(2) Å in 1 is
obviously typical for the double-bond character.
The solid-state structure of 2 has been confirmed by X-ray crys-
ꢀ
tallography. Complex 2 crystallized in the triclinic space group P1
Fig. 1. Perspective view of [(g l-g
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(O)S2}]2 1.
with centro-symmetry. Fig. 2 shows a perspective view of 2; se-
lected bond lengths and angles are given in Table 3. The neutral
complex 2 comprises two [Ru(CO)(dppm)2]2+ fragments symmetri-
cally bridged by two [ArPOS2]2ꢀ moieties via the sulfur and oxygen
atoms. Two sulfur atoms in a [ArPOS2]2ꢀ moiety chelate ruthenium
atom with a bite angle S–Ru–S of 80.62(2)°. Each ruthenium atom
code: a ꢀx + 2, ꢀy, ꢀz.] while the S(1) atom is bonded to the corre-
sponding ruthenium atom with Ru(1)–S(1) distance of 2.4308(9) Å,
which is compatible to bonding characters in the similar complex
[(g l-g
6-p-cymene)Ru{ 1(S),g2(S,S0)-ArP(S)S2}]2 [23] Accordingly,

152
Q. Ma et al. / Inorganica Chimica Acta 378 (2011) 148–153
Fig. 3. Perspective view of [Ru2Cl2(l-S){l3-g g
1(O), 1(S),g2(S,S0)-ArP(O)S2}(PPh3)2] 3.
Fig. 2. Perspective view of [Ru(CO){l3-g
1(O),g2(S,S0)-ArP(O)S2}(dppm)]2 2.
Table 4
Selected bond lengths (Å) and angles (°) for [Ru2Cl2(
ArP(O)S2}(PPh3)2]ꢁCH2Cl2 (3ꢁCH2Cl2).
l-S){l3-g g
1(O), 1(S),g2(S,S0)-
Table 3
Selected bond lengths (Å) and angles (°) for [Ru(CO){l3
(dppm)]2 (2).
-
g
1(O),g2(S,S0)-ArP(O)S2}-
Ru(1)–S(3)
Ru(2)–S(3)
Ru(2)–S(2)
Ru(1)–P(2)
Ru(2)–P(4)
Ru(2)–Cl(2)
S(2)–P(1)
2.1938(6)
2.1415(6)
2.3447(7)
2.3380(6)
2.3174(7)
2.3073(7)
2.0563(9)
Ru(1)–S(1)
Ru(2)–S(1)
Ru(1)–O(1)
Ru(1)–P(3)
Ru(1)–Cl(1)
S(1)–P(1)
2.5090(6)
2.4667(6)
2.2325(16)
2.3665(7)
2.4626(7)
2.0615(9)
1.5134(19)
Ru(1)–S(1)
Ru(1)–P(2)
Ru(1)–C(1)
P(1)–S(1)
2.4483(5)
2.3197(6)
1.811(2)
2.0396(7)
1.5130(14)
Ru(1)–S(2)
Ru(1)–P(3)
Ru(1)–O(2)#1
P(1)–S(2)
2.4492(5)
2.3201(5)
2.1729(13)
2.0471(7)
1.157(2)
P(1)–O(1)
P(1)–O(2)
C(1)–O(1)
S(3)–Ru(1)–O(1)
O(1)–Ru(1)–P(2)
O(1)–Ru(1)–P(3)
S(3)–Ru(1)–Cl(1)
P(2)–Ru(1)–Cl(1)
S(3)–Ru(1)–S(1)
P(2)–Ru(1)–S(1)
Cl(1)–Ru(1)–S(1)
S(3)–Ru(2)–P(4)
S(3)–Ru(2)–S(2)
P(4)–Ru(2)–S(2)
Cl(2)–Ru(2)–S(1)
S(2)–Ru(2)–S(1)
P(1)–S(1)–Ru(1)
P(1)–S(2)–Ru(2)
P(1)–O(1)–Ru(1)
93.52(5)
164.72(5)
93.64(5)
167.92(3)
87.46(3)
83.74(2)
95.12(2)
84.37(2)
96.99(2)
104.37(3)
97.13(2)
88.27(2)
82.39(2)
78.99(3)
86.12(3)
101.05(9)
S(3)–Ru(1)–P(2)
S(3)–Ru(1)–P(3)
P(2)–Ru(1)–P(3)
O(1)–Ru(1)–Cl(1)
P(3)–Ru(1)–Cl(1)
O(1)–Ru(1)–S(1)
P(3)–Ru(1)–S(1)
S(3)–Ru(2)–Cl(2)
Cl(2)–Ru(2)–P(4)
Cl(2)–Ru(2)–S(2)
S(3)–Ru(2)–S(1)
P(4)–Ru(2)–S(1)
P(1)–S(1)–Ru(2)
Ru(2)–S(1)–Ru(1)
Ru(2)–S(3)–Ru(1)
95.75(2)
90.73(2)
98.35(2)
81.07(5)
100.35(2)
73.83(5)
165.89(2)
115.23(3)
90.26(3)
138.47(3)
85.86(2)
177.14(2)
82.87(3)
86.24(2)
103.34(2)
S(1)–Ru(1)–S(2)
P(3)–Ru(1)–S(1)
C(1)–Ru(1)–S(2)
P(2)–Ru(1)–S(2)
C(1)–Ru(1)–O(2)#1
O(2)#1–Ru(1)–P(2)
O(2)#1–Ru(1)–P(3)
P(1)–S(1)–Ru(1)
P(1)–O(2)–Ru(1)#1
80.619(18)
104.52(2)
89.90(7)
101.641(19)
176.71(7)
80.60(4)
84.90(4)
88.26(2)
146.70(9)
P(2)–Ru(1)–S(1)
C(1)–Ru(1)–S(1)
171.826(19)
89.91(7)
O(2)#1–Ru(1)–S(2)
P(3)–Ru(1)–S(2)
C(1)–Ru(1)–P(2)
C(1)–Ru(1)–P(3)
P(2)–Ru(1)–P(3)
P(1)–S(2)–Ru(1)
Ru(1)–C(1)–O(1)
93.27(4)
174.562(19)
97.91(7)
91.86(7)
73.02(2)
88.07(2)
177.6(2)
Symmetry transformations used to generate equivalent atoms: #1 ꢀx + 2, ꢀy + 1,
ꢀz + 1.
is surrounded by two l-S, one l-O, one C and two P atoms, forming
a highly distorted octahedral geometry. The Ru–C bond length and
Ru–C–O bond angle in 2 are 1.811(2) Å and 177.6(2)°, respectively,
which are comparable to those in [Ru(CO){l3
-
g
1(O),g2(S,S0)-
membered Ru2S2 ring is almost co-planar with deviation (0.068 Å)
from the least square plane. Two Ru- 3-S bond lengths [Ru(1)–
S(1) = 2.509(1) Å and Ru(2)–S(1) = 2.468(1) Å] are obviously longer
than two Ru- -S bond lengths [[Ru(1)–S(3) = 2.194(1) Å and Ru(2)–
ArP(O)S2}(PPh3)2]2 [Ru–C = 1.804(4) Å and Ru–C–O = 174.8(4)°]
[23] and [RuH(CO){S2P(OEt)2}(PPh3)2] [Ru–C = 1.829(4) Å and
Ru–C–O = 175.4(4)°] [39]. The average Ru–P bond length of
2.3320(1) Å in 2 is normal in the ruthenium complexes with
Ru–P(dppm) bonds [40], whereas the bent angle P–O–Ru (av.
l
l
S(3) = 2.142(6) Å] in the Ru2S2 ring. The RuIV–S bond lengths in
3ꢁCH2Cl2 are compared with those in the ruthenium(IV)-thiolate
complexes [41,42]. The Ru(1)–Cl(1) bond length of 2.463(1) Å in
the octahedral core is slightly longer than the Ru(2)–Cl(2) bond
length of 2.307(1) Å in the trigonal–bipyramidal core. The bent an-
gle P–O–Ru of 101.05(9)° in 3ꢁCH2Cl2 is obviously acuter than those
146.70(9)°) in
1(O),g2(S,S0)-ArP(O)S2}(PPh3)
1(O), 2(S),g2(S,S0)-ArPOS2)(PPh3)2]2 (av. 101.08(7)°) [23],
2
is obviously larger than those in [Ru(CO)-
{l3-
g
]
2 2
(av. 143.70(15)°) and
[Ru(l-
g
g
an indicative of the bulky of the dppm ligands in complex 2.
X-ray structural analysis revealed that 3ꢁCH2Cl2 crystallized in
in [Ru(CO){l-g
1(O),g2(S,S0)-ArP(O)S2}(PPh3)]2 (av. 143.70(15)°) [23]
the triclinic space group P1, consists of one neutral complex and
and 2 (av. 146.70(9)°), but is compared with [Ru(l-g g
1(O), 2(S),
ꢀ
one CH2Cl2 solvent molecule. The molecular structure of 3 is shown
in Fig. 3, selected bond lengths and angles of 3ꢁCH2Cl2 are listed in
Table 4. The mixed-valence ruthenium atoms are bridged by the tri-
g2(S,S0)-ArPOS2)(PPh3)2]2 (av. 101.08(7)°) with two [Ru(PPh3)2]2+
moieties [23]. The RuIIꢁ ꢁ ꢁRuIV non-bonding separation of 3.401 Å
in 3ꢁCH2Cl2 is shorter than the RuIIꢁ ꢁ ꢁRuII non-bonding separation
podal [ArPOS2]2ꢀ ligand in a l3
-
g
1(O),
g
1(S),g2(S,S0) coordination
of 3.738 Å in (l-g g
1(O), 2(S),g2(S,S0)-ArPOS2)(PPh3)2]2 [23].
mode and the
l
-S2ꢀ anion. The geometry around RuII in 3ꢁCH2Cl2
Formal redox potentials of the present ruthenium–
dithiophosphonate complexes 1–3 have been determined by cyclic
voltammetry. The cyclic voltammograms of complexes 1 and 2 in
CH2Cl2 show a reversible couple at ca. 0.10–0.23 V, versus Cp2Fe+/
is a highly distorted octahedron whereas the RuIV-containing moi-
ety has a distorted trigonal {RuS2Cl} core with the
at the axial positions [S(1)–Ru(2)–P(4) = 177.14(2)°]. The four-
l3-S and PPh3

Q. Ma et al. / Inorganica Chimica Acta 378 (2011) 148–153
153
0, which is assigned as the metal-centered RuIII–RuII couple because
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This project was supported by the Natural Science Foundation
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Appendix A. Supplementary material
CCDC 800317, 800317 and 800319 contain the supplementary
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g l-g
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l
-g
1(S),-g2(S,S0)-ArP(O)S2}(PPh3)3]ꢁCH2Cl2