Synthesis and characterization of heterodinuclear thiolate complexes containing the Pd(η3-allyl)+ moiety. Crystal structure of [(dppe)Pd(μ-SC6H4Me-p)2Pd(η3-C3H5)][ClO4]

Article abstract of DOI:10.1016/S0277-5387(00)00440-X

Heterodinuclear complexes of the types [(dppe)M(μ-SR)₂Pd(η³-allyl)][ClO₄] (M = Pd or Pt) and [(dppe)Pt(μ-SC₂H₄S)Pd(η³-allyl)][ClO₄] [dppe = 1,2-bis(diphenylphosphino)ethane; allyl = C₃H₅ or C₄H₇] have been obtained by reaction of the corresponding cis-dithiolato complexes, [M(SR)₂ (dppe)] or [Pt(SC₂H₄S)(dppe)], and [Pd(η³-allyl)(PhCN)₂][ClO₄]. The identity of these complexes has been established by NMR (¹H and ³¹P) spectroscopy. The crystal structure of [(dppe)Pd(μ-SC₆H₄Me-p)₂Pd(η³-C₃H₅)][ClO₄] has been determined by single-crystal X-ray methods. The p-tolyl groups on the sulfur atoms adopt a syn conformation with respect to the central Pd-S₂-Pd core. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0277-5387(00)00440-X

www.elsevier.nl/locate/poly
Polyhedron 19 (2000) 1627–1631
Synthesis and characterization of heterodinuclear thiolate
complexes containing the Pd(h3-allyl)+ moiety. Crystal structure of
[(dppe)Pd(m-SC6H4Me-p)2Pd(h3-C3H5)][ClO4]
b
Jose´ Ruiz a, Jose´ Giner a, Venancio Rodr´ıguez a, Gregorio Lo´pez a,*, Jaume Casabo´ ,
Elies Molins c, Carles Miravitlles c
a Departamento de Qu´ımica Inorga´nica, Uni6ersidad de Murcia, 30071 Murcia, Spain
b Departament de Qu´ımica, Uni6ersitat Auto`noma de Barcelona, Campus Uni6ersitari de Bellaterra, 08193-Cerdanyola, Barcelona, Spain
c Institut de Cie`ncia de Materials de Barcelona, CSIC, Campus Uni6ersitari de Bellaterra, 08193-Cerdanyola, Barcelona, Spain
Received 1 February 2000; accepted 22 May 2000
Abstract
Heterodinuclear complexes of the types [(dppe)M(m-SR)2Pd(h3-allyl)][ClO4] (M=Pd or Pt) and [(dppe)Pt(m-SC2H4S)Pd(h3-al-
lyl)][ClO4] [dppe=1,2-bis(diphenylphosphino)ethane; allyl=C3H5 or C4H7] have been obtained by reaction of the corresponding
cis-dithiolato complexes, [M(SR)2 (dppe)] or [Pt(SC2H4S)(dppe)], and [Pd(h3-allyl)(PhCN)2][ClO4]. The identity of these com-
plexes has been established by NMR (1H and 31P) spectroscopy. The crystal structure of [(dppe)Pd(m-SC6H4Me-p)2Pd(h3-
C3H5)][ClO4] has been determined by single-crystal X-ray methods. The p-tolyl groups on the sulfur atoms adopt a syn
conformation with respect to the central PdꢀS2ꢀPd core. © 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Palladium; Platinum; Thiolate complexes; Allyl complexes
1. Introduction
synthesis and study of heterobinuclear complexes have
been the subject of active research over the past years,
as they can serve as models for active intermediates in
heterobimetallic catalysis [12].
In this paper we report the preparation of a variety
of heterodinuclear MM% (M=Pd, Pt; M%=Pd) com-
plexes with bridging thiolato ligands by using cis-dithi-
olato complexes [M(SR)2 (dppe)] [M=Pd or Pt;
dppe=1,2-bis(diphenylphosphino)ethane] and [Pd(h3-
allyl)(PhCN)2]+, which contain the readily removable
PhCN ligands, as building blocks.
The relevance of transition-metal complexes with S-
donor ligands as models of biologically redox-active
metalloproteins [1] has stimulated interest in the chem-
istry of metal thiolates [2,3]. Platinum and palladium
m-thiolate complexes are also of recent interest due to
their possible use in homogeneous catalysis [4–6]. For
example, systems of the type [Pt2(m-SR)(m-
Cl)Cl2(PR%) ]/SnCl2·H2O have a high catalytic activity
3 2
in the hydrogenation of styrene [7].
We have recently described the synthesis of di- and
tri-nuclear nickel(II), palladium(II) or platinum(II)
complexes with bridging thiolato groups of the types
[NBu4]2[M2(C6F5)4(m-SR)2], [NBu4]2[M3(C6F5)4(m-SR)4]
(M=Ni, Pd or Pt) [8,9] and [{Pd(CH2C9H6N)}2(m-
SR)(m-O2CR%%)] (CH2C9H6N=8-quinolylmethyl) [10].
Dinuclear thiolato-bridged allylpalladium complexes
have been reported recently [11]. On the other hand, the
2. Experimental
The C, H, N, S analyses were performed with a Carlo
Erba model EA 1108 microanalyzer. Decomposition
temperatures were determined with a Mettler TG-50
thermobalance at a heating rate of 5°C min−1 and the
solid sample under nitrogen flow (100 ml min−1). Mo-
lar conductivities were measured in acetone solution
* Corresponding author. Fax: +34-68-36-4148.
E-mail address: gll@fcu.um.es (G. Lo´pez).
−4
(c A 5×10
mol dm−3) with a Crison 525 conducti-
,
0277-5387/00/$ - see front matter © 2000 Elsevier Science Ltd. All rights reserved.
PII: S0277-5387(00)00440-X

1628
J. Ruiz et al. / Polyhedron 19 (2000) 1627–1631
meter. The NMR spectra were recorded on a Bruker
AC 200E or Varian Unity 300 spectrometer, using
SiMe4 and H3PO4 as standards, respectively. Infrared
spectra were recorded on a Perkin–Elmer 1430 spec-
trophotometer using Nujol mulls between polyethylene
sheets. Solvents were dried by the usual methods. The
starting complexes [M(SR)2](dppe) (M=Pd or Pt),
C, 45.5; H, 4.7; S, 7.1%. \M 148 cm2 S mol−1 1H
.
NMR (CDCl3): l 7.8–7.4 (m, 20H, aromatics dppe),
3.64 (s, 2H, Hsyn), 2.87 (s, 2H, Hanti), 2.59 (d, 4H, CH2
dppe, JHP=24.0 Hz), 2.03 (m, 4H, CH2S), 1.98 (s, 3H,
CH3 allyl), 0.86 (t, 6H, CH3 CH2S, J=7.2). 31P NMR
(CDCl3): l 60.7 (s).
Complex 5: Yield 68%; m.p. 188°C (dec.). Anal. Calc.
for C41H39ClO4P2PdPtS2: C, 46.5; H, 3.7; S, 6.1. Found:
[Pt(SC2H4S)(dppe)]
[13]
and
[Pd(h3-allyl)-
(PhCN)2][ClO4] (allyl=C3H5 or C4H7) [14] were pre-
pared by procedures described elsewhere.
Safety note. Caution! Perchlorate salts of metal com-
plexes with organic ligands are potentially explosive.
Only small amounts of these materials should be pre-
pared, and they should be handled with great caution.
C, 46.8; H, 3.8; S, 5.8%. \M 135 S cm2 mol−1 1H
.
NMR (CDCl3): l 7.7–7.3 (m, 20H, aromatics dppe),
6.96 (d, 4H, Ho of SPh, Jom=7.3 Hz), 6.81 (t, 2H, Hp
of SPh, Jmp=7.3), 6.67 (pseudo-t, 4H, Hm of SPh), 5.52
(m, 1H, CCHC allyl), 3.76 (d, 2H, Hsyn, J=6.9), 3.23
(d, 2H, Hanti, J=12.6), 2.25 (d, 4H, CH2 of dppe,
J
HP=19.8). 31P NMR (CDCl3): l 45.6 (s, JPtP=3108
2.1. Preparation of complexes 1–11
Hz).
Complex 6: Yield 73%; m.p. 194°C (dec.). Anal. Calc.
for C43H43ClO4P2PdPtS2: C, 47.5; H, 4.0; S, 6.0. Found:
C, 47.1; H, 4.0; S, 5.8%. \M 136 S cm2 mol−1 1H
NMR (CDCl3): l 7.7–7.3 (m, 20H, aromatics dppe),
6.88 (d, 4H, Ho of SC6H4Me, Jom=7.8 Hz), 6.49 (d,
4H, Hm of SC6H4Me, Jom=7.8), 5.57 (m, 1H, CCHC
To a solution of the corresponding benzonitrile com-
plex [Pd(h3-allyl)(PhCN)2][ClO4] (0.3 mmol) in
methanol (20 cm3) was added the corresponding cis-
.
dithiolato
complex
[M(SR)2
(dppe)]
or
[Pt(SC2H4S)(dppe)] (0.3 mmol) with constant stirring at
room temperature (r.t.) (2 h for the palladium com-
pounds or 4 h for the platinum complexes) to afford a
suspension from which the solvent was partially evapo-
rated under reduced pressure and, after addition of
water, filtered-off. The desired yellow complex was
air-dried.
allyl), 3.81 (d, 2H, Hsyn, J=6.9), 3.26 (d, 2H, Hanti
,
J=12.6), 2.28 (d, 4H, CH2 dppe, JHP=19.1), 2.14 (s,
6H, Me). 31P NMR (CDCl3): l 45.2 (s, JPtP=3110 Hz).
Complex 7: Yield 74%; m.p. 191°C (dec.). Anal. Calc.
for C33H39ClO4P2PdPtS2: C, 41.2; H, 4.1; S, 6.7. Found:
C, 41.3; H, 4.0; S, 7.1%. \M 131 S cm2 mol−1 1H
.
Complex 1: Yield 54%; m.p. 154°C (dec.). Anal. Calc.
for C41H39ClO4P2Pd2S2: C, 50.8; H, 4.1; S, 6.6. Found:
NMR (CDCl3): l 8.0–7.5 (m, 20H, aromatics dppe),
5.47 (m, 1H, CCHC allyl), 4.01 (d, 2H, Hsyn, J=6.7
Hz), 3.05 (d, 2H, Hanti, J=12.5), 2.50 (d, 4H, CH2
dppe, JHP=19.7), 2.17 (m, 4H, CH2S), 0.89 (t, 6H,
CH3 CH2S, J=6.6). 31P NMR (CDCl3): l 46.8 (s,
C, 50.8; H, 4.1; S, 6.3%. \M 130 S cm2 mol−1 1H
.
NMR (CDCl3): l 7.6–7.3 (m, 20H, aromatics dppe),
6.99 (d, 4H, Ho of SPh, Jom=7.7 Hz), 6.88 (t, 2H, Hp
of SPh, Jmp=7.7), 6.69 (pseudo-t, 4H, Hm of SPh), 5.56
(m, 1H, CCHC allyl), 3.76 (d, 2H, Hsyn, J=6.9), 3.25
JPtP=3055 Hz).
Complex 8: Yield 57%; m.p. 168°C (dec.). Anal. Calc.
(d, 2H, Hanti, J=12.6), 2.39 (d, 4H, CH2 dppe, JHP
=
for C42H41ClO4P2PdPtS2: C, 47.0; H, 3.9; S, 6.0. Found:
22.5). 31P NMR (CDCl3) l 60.8 (s).
C, 46.7; H, 3.7; S, 5.8%. \M 133 S cm2 mol−1 1H
.
Complex 2: Yield 55%; m.p. 189°C (dec.). Anal. Calc.
NMR (CDCl3): l 7.8–7.2 (m, 20H, aromatics dppe),
6.94 (d, 4H, Ho of SPh, Jom=7.3 Hz), 6.83 (t, 2H, Hp
of SPh, Jmp=7.3), 6.68 (pseudo-t, 4H, Hm of SPh), 3.59
(s, 2H, Hsyn), 3.12 (s, 2H, Hanti), 2.33 (d, 4H, CH2 dppe,
for C43H43ClO4P2Pd2S2: C, 51.7; H, 4.3; S, 6.4. Found:
C, 52.0; H, 4.5; S, 6.4%. \M 145 S cm2 mol−1 1H
.
NMR (CDCl3): l 7.6–7.3 (m, 20H, aromatics dppe),
6.86 (d, 4H, Ho of SC6H4Me, Jom=7.8 Hz), 6.48 (d,
4H, Hm of SC6H4Me, Jom=7.8), 5.57 (m, 1H, CCHC
J
HP=18.9), 1.96 (s, 3H, CH3 allyl). 31P NMR (CDCl3):
l 45.9 (s, JPtP=3105 Hz).
allyl), 3.76 (d, 2H, Hsyn, J=6.9), 3.24 (d, 2H, Hanti
,
Complex 9: Yield 67%; m.p. 153°C (dec.). Anal. Calc.
for C34H41ClO4P2PdPtS2: C, 41.8; H, 4.2; S, 6.6. Found:
J=12.7), 2.38 (d, 4H, CH2 dppe, JHP=22.6), 2.12 (s,
6H, Me). 31P NMR (CDCl3): l 60.0 (s).
C, 41.6; H, 4.2; S, 6.4%. \M 145 S cm2 mol−1 1H
.
Complex 3: Yield 56%; m.p. 175°C (dec.). Anal. Calc.
for C33H39ClO4P2Pd2S2: C, 45.4; H, 4.5; S, 7.3. Found:
NMR (CDCl3): l 8.0–7.3 (m, 20H, aromatics dppe),
3.71 (s, 2H, Hsyn), 2.89 (s, 2H, Hanti), 2.49 (d, 4H, CH2
dppe, JHP=20.4 Hz), 2.12 (m, 4H, CH2S), 1.99 (s, 3H,
CH3 allyl), 0.87 (t, 6H, CH3 CH2S, J=7.2). 31P NMR
(CDCl3): l 47.1 (s, JPtP=3056 Hz).
C, 45.1; H, 4.5; S, 7.3%. \M 150 S cm2 mol−1 1H
.
NMR (CDCl3): l 8.0–7.4 (m, 20H, aromatics dppe),
5.46 (m, 1H, CCHC allyl), 3.93 (d, 2H, Hsyn, J=6.9
Hz), 3.03 (d, 2H, Hanti, J=12.4), 2.59 (d, 4H, CH2
dppe, JHP=23.4), 2.03 (m, 4H, CH2S), 0.88 (t, 6H,
CH3 CH2S, J=7.2). 31P NMR (CDCl3): l 60.5 (s).
Complex 4: Yield 59%; m.p. 175°C (dec.). Anal. Calc.
for C34H41ClO4P2Pd2S2: C, 46.0; H, 4.7; S, 7.2. Found:
Complex 10: Yield 46%; m.p. 170°C (dec.). Anal.
Calc. for C31H33ClO4P2PdPtS2: C, 39.9; H, 3.6; S, 6.9.
Found: C, 39.3; H, 3.6; S, 6.8%. \M 120 S cm2 mol−1
.
1H NMR (CDCl3): l 7.9–7.3 (br m, 20H, aromatics
dppe), 5.1 (br, 1H, CCHC allyl), 4.08 (br, 2H, Hsyn),

J. Ruiz et al. / Polyhedron 19 (2000) 1627–1631
1629
Table 1
Crystal data and structure refinement for 2
Empirical formula
Formula weight
Temperature (K)
C43H43ClO4P2Pd2S2
998.08
294(2)
,
Wavelength (Mo Ka) (A)
Crystal system
0.71073
triclinic
(
Space group
Unit cell dimensions
P1 (c2)
,
a (A)
10.873(1)
11.698(1)
17.353(2)
84.733(9)
88.052(8)
77.284(8)
2143.7(4)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3
,
Volume (A )
Scheme 1.
Z
Density (calculated) (Mg m−3
)
)
1.546
1.113
Absorption coefficient (mm−1
3.0–2.5 (br m, 10H, Hanti+CH2 dppe+SCH2CH2S).
31P NMR (CDCl3): l 46.3 (s, JPtP=2748 Hz).
F(000)
1008
2.23–30.42
05h515, −165k516,
−245l524
13 602
12 973 (Rint=0.0127)
Full-matrix least-squares on
F2
12 973/1/468
1.047
q Range for data collection (°)
Index ranges
Complex 11: Yield 45%; m.p. 125°C (dec.). Anal.
Calc. for C32H35ClO4P2PdPtS2: C, 40.6; H, 3.7; S, 6.8.
Found: C, 40.3; H, 3.7; S, 6.6%. \M 135 S cm2 mol−1
.
Reflections collected
Independent reflections
Refinement method
1H NMR (CDCl3): l 7.8–7.3 (m, 20H, aromatics
dppe), 3.81 (br, 2H, Hsyn), 3.0–2.5 (br m, 10H, Hanti
+
CH2 dppe+SCH2CH2S), 1.80 (br, 3H, CH3 allyl). 31P
NMR (CDCl3): l 45.2 (s, JPtP=3050 Hz).
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
R1=0.0383, wR2=0.1184
R1=0.0580, wR2=0.1306
2.2. Determination of the X-ray crystal structure of
complex 2
Largest difference peak and hole 1.543 and −1.058
−3
,
(e A
)
A single crystal of complex 2 (approximate dimen-
sions 0.55×0.37×0.24 mm) was mounted on an En-
raf–Nonius CAD4 diffractometer equipped with a
graphite monochromator for Mo Ka radiation. The
crystallographic data are shown in Table 1 (Fig. 1).
Accurate cell parameters were determined by least-
squares fitting of 25 high-angle reflections. The scan
method was ꢀ–2[ and the empirical Psi scan mode
absorption correction was applied. The structure was
solved by heavy atom methods SHELXS-86 [15] and
refined anisotropically on F2 [16]. Hydrogen atoms
were introduced in calculated positions. The residual
peaks in the final Fourier difference synthesis were
located close to the metal atoms.
3. Results and discussion
The mononuclear palladium and platinum complexes
[M(SR)2 (dppe)] (M=Pd or Pt) or [Pt(SC2H4S)(dppe)]
[dppe=1,2-bis(diphenylphosphino)ethane] react with
[Pd(h3-allyl)(PhCN)2][ClO4] (allyl=C3H5 or C4H7) in a
1:1 molar ratio to give heterodinuclear complexes of the
types [(dppe)M(m-SR)2Pd(h3-allyl)][ClO4] (M=Pd or
Pt) (1–9) and [(dppe)Pt(m-SC2H4S)Pd(h3-allyl)][ClO4]
(10 and 11) with the concomitant release of PhCN
(Scheme 1).
Fig. 1. Perspective view of the molecular structure of 2.

1630
J. Ruiz et al. / Polyhedron 19 (2000) 1627–1631
Table 2
,
Selected distances (A) and bond angles (°) for complex 2
Bond distances
Bond angles
Pd(1)ꢀP(1)
Pd(1)ꢀP(2)
Pd(1)ꢀS(1)
Pd(1)ꢀS(2)
Pd(1)···Pd(2)
Pd(2)ꢀC(40)
Pd(2)ꢀC(39)
Pd(2)ꢀC(41)
Pd(2)ꢀS(1)
Pd(2)ꢀS(2)
2.2777(8)
2.2871(8)
2.3742(8)
2.3783(8)
3.2428(4)
2.085(5)
2.137(4)
2.140(4)
2.3465(8)
2.3524(9)
P(1)ꢀPd(1)ꢀP(2)
P(1)ꢀPd(1)ꢀS(1)
P(2)ꢀPd(1)ꢀS(1)
P(1)ꢀPd(1)ꢀS(2)
P(2)ꢀPd(1)ꢀS(2)
S(1)ꢀPd(1)ꢀS(2)
Pd(2)ꢀS(1)ꢀPd(1)
Pd(2)ꢀS(2)ꢀPd(1)
S(1)ꢀPd(2)ꢀS(2)
C(40)ꢀPd(2)ꢀS(1)
C(39)ꢀPd(2)ꢀS(1)
C(41)ꢀPd(2)ꢀS(1)
C(40)ꢀPd(2)ꢀS(2)
C(39)ꢀPd(2)ꢀS(2)
C(41)ꢀPd(2)ꢀS(2)
C(41)ꢀC(40)ꢀC(39)
85.34(3)
96.87(3)
172.13(3)
172.45(3)
95.85(3)
80.98(3)
86.77(3)
86.54(3)
82.10(3)
140.5(2)
105.58(14)
171.3(2)
137.1(2)
172.24(14)
105.1(2)
142.4(8)
1
suggests a fluxional behavior in the H NMR scale of
time. Rotation of the h3-allyl group has been suggested
as a possible dynamic process [18]. The 1H NMR
spectrum of complex 11 at −50°C (Fig. 2) shows two
different singlets at l 3.91 and 3.83 assigned to syn
protons and two additional singlets at l 1.86 and 1.80
due to the Me protons of the allyl groups of the two
conformational isomers tentatively shown in Scheme 2
(signals due to the anti protons are obscured by reso-
nances of dppe and SC2H4S ligands).
Fig. 2. Variable-temperature 1H NMR spectrum of 11.
The new complexes 1–11 have been characterized on
the basis of partial elemental analyses and spectroscopic
data and they behave in acetone as 1:1 electrolytes [17],
in accordance with the formulas given.
The 31P NMR spectra show a single resonance and
those of the platinum complexes are flanked by the
satellites due to coupling to 195Pt, the coupling constant
being in the range 2700–3100 Hz.
Suitable crystals of complex 2 were grown from
acetone–ethanol. The structure of 2 is shown in Fig. 1
and selected lengths and angles in Table 2. Both metal
atoms, Pd(1) and Pd(2), are coordinated in a slightly
distorted square-planar geometry and the phenyl
groups on the sulfur atoms adopt a syn arrangement
with respect to the central PdꢀS2ꢀPd core. The same
conformation has been recently found in [(C6F5)2Ni(m-
SPh)2Pd(dppe)] [19], [h5-C5H4SiMe3)2Ti(m-SPh)2Pd(C6-
F5)2] [20] and [h5-C5H5)Ti(m-SMe)2PtMe2] [21].
The 1H NMR spectra of complexes 1–9 show a
single set of resonances, indicating that both thiolate
ligands are equivalent and the free rotation of the
thiolate aryl or alkyl group around the CꢀS bond. The
1H NMR spectra of complexes 1–3 and 5–7 show also
three resonances with the expected intensity ratio
(1:2:2) and peak multiplicities in the allylic group region
(multiplet for CCHC, doublet for syn protons, and
doublet for anti protons) whereas the spectra of com-
plexes 4 and 8–9 show three singlet resonances for the
methylallyl group with the expected intensity ratio of
2:2:3.
,
The Pd(1)ꢀS distances are 2.3742(3) and 2.3783(8) A,
significantly longer than Pd(2)ꢀS distances, 2.3465(8)
,
and 2.3524(9) A. This is due to the strong trans influ-
ence of the phosphine ligand [19]. The Pd···Pd distance
,
is 3.2428(4) A, showing no significant metal–metal
1
However, the H NMR spectra of complexes 10 and
interaction. The PdSPdS ring adopts a hinged square-
planar geometry with a dihedral angle of 129.9° along
11 show broad bands at room temperature, which
Scheme 2.

J. Ruiz et al. / Polyhedron 19 (2000) 1627–1631
1631
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4. Supplementary material
Supplementary data for complex 2 are available from
the CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
on request, quoting the deposition number CCDC
139771. Copies of this information may be obtained
free of charge from: The Director, CCDC, 12 Union
Road, Cambridge, CB2 1EZ, UK (Fax: +44-1223-336-
033; e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
Acknowledgements
[15] G.M. Sheldrick, Crystallogr. Comp. 5 (1991) 145.
[16] G.M. Sheldrick, SHELXL-93, Program for Crystal Structure
Refinement, University of Go¨ttingen, 1993.
[17] W.J. Geary, Coord. Chem. Rev. 7 (1971) 81.
[18] S. Trofimenko, Inorg. Chem. 10 (1971) 1372.
[19] G. Sa´nchez, F. Momblona, M. Sa´nchez, J. Pe´rez, G. Lo´pez, J.
Casabo´, E. Molins, C. Miravitlles, Eur. J. Inorg. Chem. (1998)
1199.
Financial support from the DGICYT (project PB97-
1036), Spain, is gratefully acknowledged. V.R. thanks
CajaMurcia, Spain, for a research grant.
References
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