Synthesis of heteroleptic nickel(II) and palladium(II) dithiolenes

Article abstract of DOI:10.1016/j.poly.2006.04.010

Deprotection of 4-(p-cyanophenyl)-1,3-dithiole-2-thione, 4-(2-thienyl)-1,3-dithiole-2-one (1) and 4-(3-thienyl)-1,3-dithiole-2-one (2) with a base in MeOH or KOH and the posterior addition of nickel(II) and palladium(II) complexes give the formation of heteroleptic dithiolenes with 1,2-bis(diphenylphosphino)ethane, dppe, as an additional ligand. The X-ray analyses of two Pd-dithiolenes show a planar five-membered ring involving the metallic center and the dithiolene unit.

Full text of DOI:10.1016/j.poly.2006.04.010

Polyhedron 25 (2006) 2785–2790
www.elsevier.com/locate/poly
Synthesis of heteroleptic nickel(II) and palladium(II) dithiolenes
*
´
Nora Lardies, Elena Cerrada , Mariano Laguna
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n, Universidad de Zaragoza-C.S.I.C., 50009 Zaragoza, Spain
Received 7 March 2006; accepted 3 April 2006
Available online 27 April 2006
Abstract
Deprotection of 4-(p-cyanophenyl)-1,3-dithiole-2-thione, 4-(2-thienyl)-1,3-dithiole-2-one (1) and 4-(3-thienyl)-1,3-dithiole-2-one (2)
with a base in MeOH or KOH and the posterior addition of nickel(II) and palladium(II) complexes give the formation of heteroleptic
dithiolenes with 1,2-bis(diphenylphosphino)ethane, dppe, as an additional ligand. The X-ray analyses of two Pd-dithiolenes show a
planar five-membered ring involving the metallic center and the dithiolene unit.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: Heteroleptic dithiolenes; Nickel; Palladium
1. Introduction
By contrast with the number of homoleptic dithiolene
complexes prepared, particularly the square-planar com-
plexes of d8 metal anions (Ni, Pt and Pd) [2]; only a few
heteroleptic complexes are known [15–17], which involve
one or more dithiolate ligands together with other ligands
(2,20-bipyridine, 1,2-bis(diphenylphosphino)ethane, cyclo-
pentadienyl, CN) in the metal coordination sphere.
Following our previous work on the synthesis of dithio-
lene complexes with aromatic substituents [18,19], in this
paper we report on the synthesis of heteroleptic dithiolene
complexes of the type of [M{S2C2H-R}(dppe)] (dppe =
1,2-bis(diphenyldiphosphino)ethane, M = Ni, Pd and
R = p-cyanophenyl, 2-thienyl, 3-thienyl) and the X-ray
characterisation of two of them with palladium as the
metallic center.
Considerable research has focused on the synthesis,
reactivity and physical and photophysical properties of
dithiolene complexes bearing transition metals [1,2]. The
uniqueness of the dithiolenes stems from their ability to
exits in several clearly define oxidation states due to the
high degree of electron delocalisation [3–6] observed in
the metalladithiolene ring (consisting of the metal, the
two sulfur and two unsaturated carbons), which also man-
ifests itself in intense electronic transitions at unusually low
energies. As a consequence of this, transition metal com-
plexes with dithiolene ligands have interesting and versatile
properties [7–10] such as electrical conductivity, molecular
magnetism (favoured for their planar geometry) and cata-
lytic behavior. The most outstanding property with more
potential applications is based on their intense electronic
transition in the near-IR region. Thus, dithiolenes have
been used for Q-switching near infrared (NIR) laser, which
allows the generation of short and very intense pulses, since
the 1970s [11–14].
2. Experimental
2.1. General comments
All reactions and product manipulations were per-
formed under an argon atmosphere using standard
Schlenck techniques. THF was dried over and distilled
from Na. NMR spectra were recorded on a Varian Gemini
300 MHz or a Bruker ARX 400 MHz spectrometer, IR
spectra were measured with a Perkin–Elmer 883 or
*
Corresponding author. Tel.: +976761000; fax: +976761187.
E-mail addresses: ecerrada@unizar.es (E. Cerrada), mlaguna@
unizar.es (M. Laguna).
0277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2006.04.010

2786
N. Lardie´s et al. / Polyhedron 25 (2006) 2785–2790
Perkin–Elmer FT-IR Espectrum One, as KBr pellets. UV
spectra of 0.1 mM solutions were obtained with a UNI-
CAM UV 300 and mass spectra were obtained with a
VG Autospec mass spectrometer operating in the electron
Impact (EI) mode and liquid secondary iron mass spec-
trometry (LSIMS) mode. Elemental compositions were
analysed with a Perkin–Elmer 2400B. 4-(2-Thienyl)-1,3-
dithiol-2-thione [20], 4-(3-thienyl)-1,3-dithiol-2-thione [20]
and 4-(p-cyanophenyl)-1,3-dithiole-2-thione [18,20] were
prepared by published methods. Electrochemical measure-
ments were recorded on a EG&G 273 model and carried
out in dry CH2Cl2 under argon using [n-NBu4]PF6
(0.1 M) as a background electrolyte, with a Pt disk elec-
trode versus SCE (values in V).
2.16; S, 9.90. Found: C, 64.68; H, 4.86; N, 2.09; S,
10.01%. IR (KBr, cmꢀ1): m(C„N) 2218, m(C@C) 1597.
1H NMR (300 MHz, CDCl3, 25 ꢁC): d 7.80–7.66 (m,
10H), 7.46–7.36 (m, 14H), 7.30 (s, 1H), 2.38 (d, 4H,
J = 17.4 Hz) ppm. 31P{1H} NMR: AB system dA = 58.6,
dB = 57.9 ppm (JAB = 46.5 Hz). m/z (LSIMS+): 647
([M]+, 100%). M = Pd (4), orange solid. Yield: 65%. Anal.
Calc. for [C35H29NP2PdS2]: C, 60.39; H, 4.20; N, 2.01; S,
9.21. Found: C, 59.99; H, 4.15; N, 1.96; S, 9.21%. IR
(KBr, cmꢀ1): m(C„N) 2213, m(C@C) 1599. 1H NMR
(300 MHz, CDCl3, 25 ꢁC): d 7.84–7.73 (m, 10H), 7.52–
7.40 (m, 14H), 7.20 (d, 1H, J = 3.6 Hz), 2.53 (d, 4H,
J = 20.7 Hz) ppm. 31P{1H} NMR: AB system dA = 51.7,
dB = 51.6 ppm (JAB=36.1 Hz). m/z (LSIMS+): 695 ([M]+,
100%).
2.2. 4-(2-Thienyl)-1,3-dithiole-2-one (1)
2.5. [M{S2C2H-(2-C4H3S)}(dppe)], M = Ni (5), Pd (6)
To
a
solution of 4-(2-thienyl)-1,3-dithiol-2-thione
(216 mg, 1 mmol) in MeCN (10 ml) was added Hg(OAc)2
(414 mg, 1.3 mmol). The mixture was refluxed for 6 h and
after cooling the solvent was completely removed in vacuo.
Purification was carried out by column chromatography
(silica, CH2Cl2). The resulting solution was carefully
washed with sat. Na2CO3 and water. After drying
(Na2SO4) the solvent was evaporated in vacuo to afford a
yellow solid. Yield: 85%. Anal. Calc. for [C7H4OS3]: C,
41.93; H, 2.01; S, 47.92. Found: C, 41.95; H, 2.42; S,
47.52%. IR (KBr, cmꢀ1): m(C@O) 1638. 1H NMR
(300 MHz, CDCl3, 25 ꢁC): d 7.30–7.28 (m, 1H, H5-thienyl),
7.07–7.03 (m, 2H, H3,4-thienyl), 6.73 (s, 1H, H5-di-
thiole) ppm. m/z (EI+): 200 ([M]+, 16%), 136 (100%).
4-(2-Thienyl)-1,3-dithiole-2-one (1) (50 mg, 0.25 mmol)
was suspended in EtOH (10 ml) under argon atmosphere,
for M = Pd in THF (10 ml). NaOEt (2 ml, 0.4 M in EtOH)
was added and the reaction mixture was refluxed until the
ketone was dissolved (1.5 h). After cooling [NiCl2(dppe)]
(132 mg, 0.25 mmol) or [PdCl2(dppe)] (144 mg, 0.25 mmol)
was added. The reaction mixture was stirred for 24 h and
then the solvent was reduced in vacuo to 5 ml. Hexane or
diethyl ether (20 ml) was added to precipitate the corre-
sponding compound which was filtered off. Purification
was carried out by column chromatography. M = Ni (5),
(silica, 60 ethyl acetate/40 hexane), green solid. Yield:
15%. Anal. Calc. for [C32H28NiP2S3]: C, 61.05; H, 4.45;
S, 15.26. Found: C, 60.68; H, 4.06; S, 14.88%. IR (KBr,
cmꢀ1): m(C@C) 1633. 1H NMR (300 MHz, CDCl3,
25 ꢁC): d 7.77–7.70 (m, 8H), 7.45–7.19 (m, 12H), 6.92 (m,
2H), 6.84 (m, 1H), 6.72 (m, 1H), 2.35–2.27 (m, 4H) ppm.
31P{1H} NMR: AB system dA = 58.0, dB = 57.5 ppm
(JAB = 34.8 Hz). m/z (LSIMS+): 628 ([M]+, 100%), 431
([S(dppe)+], 72%). M = Pd (6), (silica, dichloromethane),
purple solid. Yield: 49%. Anal. Calc. for [C32H28P2PdS3]:
C, 56.71; H, 4.13; S, 14.18. Found: C, 56.40; H, 4.43; S,
13.68%. IR (KBr, cmꢀ1): m(C@C) 1634. 1H NMR
(300 MHz, CDCl3, 25 ꢁC): d 7.77–7.68 (m, 9H), 7.37–7.33
(m, 11H), 6.99 (m, 1H), 6.89–6.83 (m, 2H), 6.72 (m, 1H),
2.42 (d, 4H, J = 15.3 Hz) ppm. 31P{1H} NMR: AB system
dA = 50.9, dB = 50.7 ppm (JAB = 26.7 Hz). m/z (LSIMS+):
676 ([M]+, 100%), 506 ([Pd(dppe)], 18%), 429 ([S(dppe)],
32%).
2.3. 4-(3-Thienyl)-1,3-dithiole-2-one (2)
This compound was prepared as described for 1 using 4-
(3-thienyl)-1,3-dithiol-2-thione (216 mg, 1 mmol). Yellow
solid. Yield: 80%. Anal. Calc. for [C7H4OS3]: C, 41.93; H,
2.01; S, 47.92. Found: C, 41.54; H, 2.40; S, 47.49%. IR
1
(KBr, cmꢀ1): m(C@O) 1628. H NMR (300 MHz, CDCl3,
25 ꢁC): d 7.42–7.18 (m, 1H, H2-thienyl), 7.30–7.23 (m,
2H, H4,5-thienyl), 6.77 (s, 1H, H5-dithiole) ppm. m/z
(EI+): 200 ([M]+, 100%), 172 ([M–C–O]+, 52%), 140
([M–C–O–S]+, 12%).
2.4. [M{S2C2H-(p-CN-C6H4)}(dppe)], M = Ni (3), Pd
(4)
4-(p-Cyanophenyl)-1,3-dithiole-2-thione
(47 mg,
0.2 mmol) was suspended in MeOH (20 ml) under argon
atmosphere. KOH (0.5 ml, 1 M in MeOH) was added
and the reaction mixture was refluxed until the thione
was dissolved (3 h). After cooling [NiCl2(dppe)] (106 mg,
0.2 mmol) or [PdCl2(dppe)] (115 mg, 0.2 mmol) was added.
The reaction mixture was stirred for 24 h and the precipi-
tate was subsequently collected by filtration and washed
with diethyl ether. M = Ni (3), green solid. Yield: 45%.
Anal. Calc. for [C35H29NNiP2S2]: C, 64.90; H, 4.51; N,
2.6. [M{S2C2H-(3-C4H3S)}(dppe)], M = Ni (7), Pd (8)
4-(3-Thienyl)-1,3-dithiole-2-one (2) (50 mg, 0.25 mmol)
was suspended in THF (15 ml). NaOEt (2 ml, 0.4 M in
EtOH) was added and the reaction mixture was refluxed
until the ketone was dissolved (1.5 h). After cooling
[NiCl2(dppe)] (132 mg, 0.25 mmol) or [PdCl2(dppe)]
(144 mg, 0.25 mmol) was added. The reaction mixture
was stirred for 24 h and then the solvent was reduced in

N. Lardie´s et al. / Polyhedron 25 (2006) 2785–2790
2787
vacuo to 5 ml. Hexane (20 ml) was added to precipitate the
3. Results and discussion
corresponding compound which was filtered off. M = Ni
(7), green solid. Yield: 44%. Anal. Calc. for
[C32H28NiP2S3]: C, 61.05; H, 4.45; S, 15.26. Found: C,
60.67; H, 4.48; S, 14.84%. IR (KBr, cmꢀ1): m(C@C) 1629.
1H NMR (300 MHz, CDCl3, 25 ꢁC): d 7.77–7.61 (m,
10H), 7.44–7.37 (m, 10H), 7.19–7.13 (m, 2H), 7.00 (m,
1H), 6.93 (s, 1H), 2.30 (d, 4H, J = 13.2 Hz) ppm. 31P{1H}
Deprotection of 4-(p-cyanophenyl)-1,3-dithiole-2-thione
[18,20], 4-(2-thienyl)-1,3-dithiole-2-one (1) and 4-(3-
thienyl)-1,3-dithiole-2-one (2) with a base in MeOH or in
THF (to improve the solubility) leads to the formation
in situ of the corresponding dithiolate salts. Curiously the
formation of the dithiolates takes place starting from the
thione (Scheme 1, (i)) in the case of p-cyanophenyl, though
in the case of 2- and 3-thienyl the transformation is on the
corresponding ketone, in order to improve the electrophi-
licity around the C atom in the 2 position, necessary as a
previous reaction. Subsequent addition of [NiCl2(dppe)]
and [PdCl2(dppe)] followed by purification work-up affor-
ded the heteroleptic complexes as shown in Scheme 1.
The spectroscopic data of all the dithiolenes are in
agreement with their formulation. In the 1H NMR spectra,
the proton of the S2C2H unit appears as a doublet or mul-
tiplet, possibly due to the coupling of this proton with the P
atom in the trans position. More illustrative are the
31P{1H} NMR spectra, most of them show an AB system
around 58 ppm for Ni complexes and 51 ppm for Pd com-
plexes. This AB system is due to the closed resonances of
the two inequivalent phosphorous atoms because of the
lack of symmetry of the dithiolene ligand used in this work.
The LSIMS+ mass spectra exhibit the molecular peaks in
all cases.
NMR:
AB
system
dA = 57.8,
dB = 57.6 ppm
(JAB = 34.1 Hz). m/z (LSIMS+): 628 ([M]+, 100%), 431
([S(dppe)+], 25%). M = Pd (8), brown solid. Yield: 90%.
Anal. Calc. for [C32H28P2PdS3]: C, 56.71; H, 4.13; S,
14.18. Found: C, 56.40; H, 4.21; S, 13.76%. IR (KBr,
cmꢀ1): m(C@C) 1638. 1H NMR (300 MHz, CDCl3,
25 ꢁC): d 7.80–7.71 (m, 8H), 7.43–7.35 (m, 12H), 7.21 (m,
2H), 7.03 (m, 1H), 6.85 (m, 1H), 2.43 (d, 4H,
J = 15.3 Hz) ppm. 31P{1H} NMR: d 50.5 (s) ppm. m/z
(LSIMS+): 676 ([M]+, 100%), 476 (52%), 291 (72%).
2.7. Crystallographic studies
Crystals suitable for X-ray diffraction were obtained by
slow diffusion of diethyl ether into dichloromethane solu-
tions. A summary of the fundamental crystal and refine-
ment data of compounds 4 and 6 is given in Table 3. The
crystals were mounted on a glass fiber with inert oil and
centered on a Bruker Nonius Kappa CCD diffractometer
in the case of 4 and on a Bruker-Siemens Smart CCD dif-
fractometer in 6 using monochromated Mo Ka radiation
Crystals of the palladium complexes [Pd{S2C2H-(p-CN-
C6H4)}(dppe)] (4) and [Pd{S2C2H-(2-C4H3S)}(dppe)] (6)
were grown by slow diffusion of diethyl ether into a di-
chloromethane solution of each complex. Perspective
drawings of the structures are shown in Figs. 1 and 2
respectively. Bond distances and angles are collected in
Tables 1 and 2 and crystallographic data are collected in
Table 3.
˚
(k = 0.7107 A), scan type h–2h. The diffraction frames were
integrated using the SAINT [21] package and corrected for
absorption with SORTAV [22,23] or SADABS [24] programs.
The structures were solved by direct methods using SHELXS
[25]. Full-matrix least squares refinement was carried out
2
using SHELXTL [26] minimising xðF o2 ꢀ F c2Þ . Hydrogen
atoms were included using a riding model. Weighted R fac-
tors (Rw) and all goodness-of-fit S values are based on F2;
conventional R factors (R) are based on F.
The crystalline structure of the two compounds is simi-
lar to that of other group 10 metallo-1,2-enedithiolate com-
plexes [8,27–33]. Compound 6 crystallises as the water
Ph2
S-
S-
S
S
iv)
S
S
P
i)
S
M
P
R
R
R
Ph2
M = Ni (3), Pd (4)
R = NC
ii)
Ph2
S-
S-
iv)
S
S
S
S
P
iii)
O
M
P
R
R
R
Ph2
M = Ni (5,7), Pd (6,8)
R =
S
S
i) KOH/MeOH, ii) Hg(OAc)2, iii) NaOEt/ THF, iv) [MCl2(dppe)]
Scheme 1. Synthesis of heteroleptic dithiolene complexes.

2788
N. Lardie´s et al. / Polyhedron 25 (2006) 2785–2790
Table 1
˚
Bond lengths (A) and angles (ꢁ) for [Pd{S2C2H-(p-CNC6H4)}(dppe)] (4)
Pd(1)–P(1)
Pd(1)–P(2)
Pd(1)–S(1)
2.2808(13)
2.2869(12)
2.2893(12)
Pd(1)–S(2)
N(1)–C(9)
2.2980(13)
1.094(8)
P(1)–Pd(1)–P(2)
P(1)–Pd(1)–S(1)
P(2)–Pd(1)–S(2)
S(1)–Pd(1)–S(2)
C(51)–P(1)–Pd(1)
C(41)–P(1)–Pd(1)
C(10)–P(1)–Pd(1)
86.09(5)
93.66(5)
91.90(5)
P(2)–Pd(1)–S(1)
P(1)–Pd(1)–S(2)
C(21)–P(2)–Pd(1)
C(31)–P(2)–Pd(1)
C(11)–P(2)–Pd(1)
C(1)–S(1)–Pd(1)
C(2)–S(2)–Pd(1)
179.12(4)
177.77(4)
114.31(15)
120.45(14)
107.51(15)
103.28(17)
103.73(16)
88.34(5)
114.48(15)
122.48(15)
106.74(15)
Table 2
˚
Bond lengths (A) and angles (ꢁ) for [Pd{S2C2H-(2-C4H3S)}(dppe)] (6)
Pd(1)–P(1)
Pd(1)–P(2)
Pd(1)–S(1)
Pd(1)–S(2)
Pd(2)–P(4)
Pd(2)–P(3)
2.2716(16)
2.2778(15)
2.2935(14)
2.3114(16)
2.2721(17)
2.2903(16)
Pd(2)–S(5)
Pd(2)–S(4)
C(1)–C(2)
C(5)–C(6)
C(33)–C(34)
C(39)–C(40)
2.2969(17)
2.3068(17)
1.341(8)
1.312(12)
1.338(10)
1.531(9)
Fig. 1. Crystal structure of [Pd{S2C2H-(p-CN-C6H4)}(dppe)] (4). Thermal
ellipsoids are drawn at the 50% probability level and H atoms have been
omitted for clarity.
solvate with two independent molecules per unit cell. The
P–Pd–P angles are very similar in both complexes, [P(1)–
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)
P(4)–Pd(2)–P(3)
P(4)–Pd(2)–S(5)
P(3)–Pd(2)–S(5)
P(4)–Pd(2)–S(4)
P(3)–Pd(2)–S(4)
S(5)–Pd(2)–S(4)
C(1)–S(1)–Pd(1)
C(2)–S(2)–Pd(1)
85.00(6)
90.84(5)
167.89(6)
175.92(6)
95.65(6)
89.31(6)
84.71(6)
89.91(6)
171.91(6)
177.97(6)
97.01(6)
88.48(6)
102.4(2)
102.5(2)
C(34)–S(4)–Pd(2)
C(33)–S(5)–Pd(2)
C(9)–P(1)–Pd(1)
C(15)–P(1)–Pd(1)
C(7)–P(1)–Pd(1)
C(21)–P(2)–Pd(1)
C(27)–P(2)–Pd(1)
C(8)–P(2)–Pd(1)
C(41)–P(3)–Pd(2)
C(47)–P(3)–Pd(2)
C(40)–P(3)–Pd(2)
C(59)–P(4)–Pd(2)
C(53)–P(4)–Pd(2)
C(39)–P(4)–Pd(2)
103.5(2)
Pd(1)–P(2) = 86.09(5)ꢁ in
4
and P(1)–Pd(1)–P(2) =
102.9(2)
118.9(2)
112.81(18)
108.1(2)
124.4(2)
109.45(19)
108.1(2)
113.4(2)
123.85(19)
107.7(2)
117.3(2)
113.7(2)
107.3(2)
85.00(6)ꢁ, P(4)–Pd(2)–P(3) = 84.71(6)ꢁ in 6] as occurs with
the S–Pd–S angles [S(1)–Pd(1)–S(2) = 88.34(5)ꢁ in 4 and
S(1)–Pd(1)–S(2) = 89.31(5)ꢁ; S(5)–Pd(2)–S(4) = 88.48(6)ꢁ
in 6]. The metallo-1,2-enedithiolate consists of a planar
five-membered ring in the two cases with the palladium
atom deviating slightly from the least squares planes,
˚
˚
0.0143(6) A in 4 and 0.0387(7), 0.0571(14) A in the two
independent molecules of 6. The substituents p-cyanophe-
nyl in 4 and 2-thienyl in 6 are also coplanar with the
metallo-1,2-dithiolene unit with smaller torsion angles in
the case of the two molecules of complex 6 [C(33)–C(34)–
Fig. 2. Crystal structure of the two independent molecules of [Pd{S2C2H-(2-C4H3S)}(dppe)] (6). Thermal ellipsoids are drawn at the 50% probability level
and H atoms have been omitted for clarity.

N. Lardie´s et al. / Polyhedron 25 (2006) 2785–2790
2789
Table 3
4. Concluding remarks
Summary of the crystallographic data for complexes [Pd{S2C2H-
(p-CNC6H4)}(dppe)] (4) and [Pd{S2C2H-(2-C4H3S)}(dppe)] (6)
We have presented the synthesis and complete charac-
terisation of heteroleptic nickel and palladium dithiolenes
via deprotection of the corresponding starting thiones
and subsequent addition of the metallic derivatives with
1,2-bis(diphenylphosphino)ethane as an ancillary ligand.
The X-ray analyses of two Pd-dithiolenes show a planar
five-membered ring involving the metallic center and the
dithiolene unit.
4
6
Empirical formula
Formula weight
Temperature (K)
Crystal system
Space group
C35H29NP2PdS2
696.05
150(2)
monoclinic
P21/c
11.453(2)
19.734(4)
14.318(3)
90
105.81(3)
90
3113.8(11)
4
1.485
0.859
C64H53OP4Pd6
1367.10
100(2)
orthorhombic
Pbcn
˚
a (A)
49.977(5)
15.397(5)
16.191(5)
90
90
90
112459(6)
8
1.460
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
Acknowledgment
3
˚
´
We thank the Ministerio de Ciencia y Tecnologıa of
V (A )
Z
Spain for financial support (CTQ2005-08099-C03-01).
Dc (Mg/m3)
l (mmꢀ1
)
0.922
Appendix A. Supplementary material
Crystal size (mm)
h Range for data collection (ꢁ)
Number of data collected
0.25 · 0.24 · 0.04
2.96–30.48
20982
0.55 · 0.16 · 0.08
1.63–27.09
75856
Crystallographic data for the structural analyses have
been deposited with the Cambridge Crystallographic Data
Centre, CCDC No. 600597 for compound 4 and CCDC
No. 600598 for compound 6. 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. Supplementary data associated with
this article can be found, in the online version, at
doi:10.1016/j.poly.2006.04.010.
Number of unique data [Rint
R1a(F2 > 2r(F2))
]
7877 [0.0773]
0.0568
0.1638
1.026
1.789, ꢀ1.539
13666 [0.0717]
0.0647
0.1679
1.099
1.736, ꢀ1.088
b
-R2 (all data)
Sc (all data)
Residual q (e A )
3
˚
P
P
a
R1(F) = iFo| ꢀ |Fci/ |Fo|.
P
P
2
2 1=2
2
b
-R2ðF 2Þ ¼ ½ ½-ðF 2o ꢀ F c2Þ ꢁ= ½wðF o2Þ ꢁ ; wꢀ1 ¼ ½r2ðF 2oÞ þ ðaPÞ þ
bPꢁ; where P ¼ ½maxðF 2o; 0Þ þ 2F c2ꢁ=3.
P
S ¼ ½ ½-ðF 2o ꢀ F c2Þ ꢁ=ðn ꢀ pÞꢁ1=2, where n is the number of reflections
2
c
and p the number of refined parameters.
C(35)–S(6) = 9.1ꢁ and C(1)–C(2)–C(3)–S(2) = 9.5ꢁ in 6 and
C(2)–C(3)–C(8)–S(2) = 13ꢁ in 4]. The Pd–S bond lengths
are in the range of other Pd-dithiolene complexes [31,34–
37]. The C–C bonds in the dithiolene unit are best
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E21=2
+0.39v +0.52v(i) +0.42v +0.39v
+1.16v(i) +1.11v(i)
+0.408v +0.38v

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