New thiosemicarbazone palladacycles with chelating bis(diphenylphosphino)methane

Article abstract of DOI:10.1016/j.poly.2006.04.013

Treatment of the thiosemicarbazones 2-ClC₆H₄C(Me){double bond, long}NN(H)C({double bond, long}S)NHR, (R: Me, a; Et, b) and 2-BrC₆H₄C(Me){double bond, long}NN(H)C({double bond, long}S)NHR (R: Me, c; Et, d) with lithium tetrachloropalladate(II) in methanol or palladium(II) acetate in acetic acid gave the tetranuclear cyclometallated complexes [Pd{2-XC₆H₃C(Me){double bond, long}NN{double bond, long}C(S)NHR}]₄ (X/R: Cl/Me, 1a; Cl/Et, 1b; Br/Me, 1c; Br/Et, 1d). Reaction of 1a-1d with bis(diphenylphosphino)methane, Ph₂PCH₂PPh₂, in a 1:4 molar ratio and concentrated hydrochloric acid gave the mononuclear complexes [Pd{2-XC₆H₃C(Me){double bond, long}NN(H)-C({double bond, long}S)NHR}(Ph₂PCH₂PPh₂-P,P)](Cl) (2a-2d). Reaction of 1a-1d with bis(diphenylphosphino)methane, Ph₂PCH₂PPh₂, in 1:2 and 1:4 molar ratios gave the dinuclear or mononuclear complexes [{Pd[2-XC₆H₃C(Me){double bond, long}NN{double bond, long}C(S)NHR]}₂(μ-Ph₂PCH₂PPh₂)] (3a-3d), and [Pd{2-XC₆H₃C(Me){double bond, long}NN{double bond, long}C(S)NHR}(Ph₂PCH₂PPh₂-P)] (4a-4d), with bridging and chelating diphosphine, respectively. The molecular structures of complexes 1b, 1d, 4c and 4d have been determined by X-ray diffraction analysis.

Full text of DOI:10.1016/j.poly.2006.04.013

Polyhedron 25 (2006) 2848–2858
www.elsevier.com/locate/poly
New thiosemicarbazone palladacycles with
chelating bis(diphenylphosphino)methane
a
a
a
a
a
´
´
Javier Martınez , Luis A. Adrio , Jose M. Antelo , M Teresa Pereira ,
b
a,
*
´
´
Jesu´s J. Fernandez , Jose M. Vila
a
Departamento de Quı´mica Inorga´nica, Universidad de Santiago de Compostela, Avenida de las Ciencias s/n, 15782 Santiago de Compostela, Spain
b
Departamento de Quı´mica Fundamental, Universidad de A Corun˜a, 15071 A Corun˜a, Spain
Received 18 December 2005; accepted 10 April 2006
Available online 27 April 2006
Abstract
Treatment of the thiosemicarbazones 2-ClC6H4C(Me)@NN(H)C(@S)NHR, (R: Me, a; Et, b) and 2-BrC6H4C(Me)@
NN(H)C(@S)NHR (R: Me, c; Et, d) with lithium tetrachloropalladate(II) in methanol or palladium(II) acetate in acetic acid gave the
tetranuclear cyclometallated complexes [Pd{2-XC6H3C(Me)@NN@C(S)NHR}]4 (X/R: Cl/Me, 1a; Cl/Et, 1b; Br/Me, 1c; Br/Et, 1d).
Reaction of 1a–1d with bis(diphenylphosphino)methane, Ph2PCH2PPh2, in a 1:4 molar ratio and concentrated hydrochloric acid gave
the mononuclear complexes [Pd{2-XC6H3C(Me)@NN(H)–C(@S)NHR}(Ph2PCH2PPh2-P,P)](Cl) (2a–2d). Reaction of 1a–1d with
bis(diphenylphosphino)methane, Ph2PCH2PPh2, in 1:2 and 1:4 molar ratios gave the dinuclear or mononuclear complexes
[{Pd[2-XC6H3C(Me)@NN@C(S)NHR]}2(l-Ph2PCH2PPh2)] (3a–3d), and [Pd{2-XC6H3C(Me)@NN@C(S)NHR}(Ph2PCH2PPh2-P)]
(4a–4d), with bridging and chelating diphosphine, respectively. The molecular structures of complexes 1b, 1d, 4c and 4d have been deter-
mined by X-ray diffraction analysis.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: Cyclometallation; Thiosemicarbazones; Palladium; C–H activation; Crystal structure
1. Introduction
features they comprise, and also because of the reactivity
possibilities they exhibit. Unique to the terdentate
[C,N,S] case, the well-known thiosemicarbazone ligands
which afford tetranuclear cyclometallated compounds, is
the strength of the Pd–Schelating bond, which hinders open-
ing of the metallated and coordination rings at the metal
center, thus allowing the ligands to be excellent pincer
species which strongly fasten three of the four metal coor-
dination sites, leaving only one for further reaction with
nucleophiles. Consequently, treatment of the tetramers
with diphosphines did not give in any case species with the
phosphine ligand in a chelating mode, and only complexes
with bridging or with mono-coordinate diphosphines were
obtained [21,22]; in the latter case, the corresponding com-
pounds may behave as bidentate [P,S] metalloligands as we
have previously shown [23]. Nevertheless, regeneration of
the hydrazinic NH bond was possible by treatment of the
corresponding compound with concentrated hydrochloric
The diversity of metals and ligands that may be encoun-
tered when dealing with cyclometallated compounds is
prominent, as well as the usages these species display.
Thus, cyclometallation, i.e., the process of intramolecular
C–H activation of coordinated ligands by transition
metals, has been widely investigated [1–5], and applications
reaching from the synthesis of new organic and organome-
tallic compounds to mesogenic species and catalytic mate-
rials [6–14] have been studied. Particularly interesting are
the multidonor ligands which may bind in a terdentate
fashion to the metal center via [C,N,X] (X = N [15–18],
O [19,20], S [21,22]) atoms, in view of the structural
*
Corresponding author. Tel.: +34(9)8152800; fax: +34(9)81595012.
E-mail address: qideport@usc.es (J.M. Vila).
0277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2006.04.013

J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
2849
acid, however without cleavage of the Pd–Schelating bond.
Therefore, in view of these findings and in our efforts to
succeed in devising a route aimed at the preparation of
cyclometallated thiosemicarbazone complexes with chelat-
ing diphosphines we reasoned that reaction of the tetranu-
clear palladacycles with a strong chelating diphosphine,
plus concentrated hydrochloric acid, should suffice to yield
the aforementioned species, and the results of this enter-
prise are presented herein.
the ligands by any one of the two alternative methods
described, i.e., (a) lithium tetrachloropalladate and sodium
acetate in methanol; or (b) palladium(II) acetate in glacial
acetic acid, resulted in all cases in tetranuclear species,
[Pd{2-XC6H3C(Me)@NN@C(S)NHR}]4 (X/R: Cl/Me,
1a; Cl/Et, 1b; Br/Me, 1c; Br/Et, 1d) as air-stable solids,
with the ligand in the E,Z configuration, which were fully
characterized by microanalytical, mass spectra, IR and
1H NMR determinations (see Section 6). The mass
spectrum (FAB) showed peaks at m/z 1384 (1a), 1441
(1b), 1563 (1c) and 1620 (1d) for the molecular ion whose
isotopic composition suggests a tetranuclear complex of
the formula C40H40Cl4N12Pd4S4 (1a), C44H48Cl4N12Pd4S4
(1b), C40H40Br4N12Pd4S4 (1c) and C44H48Br4N12Pd4S4
(1d) (see Section 6).
The m(C@N) band was shifted to lower wavenumbers ca.
30 cmꢀ1 [24] indicating palladium coordination to the
C@N moiety through the nitrogen lone pair [25,26]. The
absence of the NH proton resonance in the 1H NMR spec-
tra was in agreement with deprotonation of the hydrazinic
nitrogen atom [27,28]; accordingly, the C@S double bond
character was minimized as confirmed by the non-existence
of the m(C@S) band [29]. Metallation of the ligands was
2. Results and discussion
The ligands a–d were synthesized by reaction of 4-
methyl or 4-ethyl-3-thiosemicarbazide with 20-chloro- or
20-bromoacetophenone as appropriate, in good yields,
and were adequately characterized (see Section 6). The
most prominent features were the characteristic m(N–H)
bands in the IR spectra ca. 3350 and 3200 cmꢀ1, assigned
to the NHR and NH groups, respectively; distinctive
m(C@N) and m(C@S) stretches appeared in the ranges
1620–1590 and 840–800 cmꢀ1, also, respectively. The
NHR and NH proton resonances in the 1H NMR
appeared ca. d 8.6 and 7.5 ppm, respectively. Reaction of
RHN
N
Me
N
S
Pd
Ph2
P
Ph2
P
X
Pd
X
N
S
Me
N
NHR
Ph2
P
3a, 3b, 3c, 3d
X
Pd
P
Cl
N
Me
Ph2
iii
HN
S
4
NHR
2a, 2b, 2c, 2d
3
5
6
ii
X
i
X
Pd
N
Me
N
S
Me
HN
S
iv
v
N
NHR
NHR
4
a: R = Me; X = Cl
b: R = Et; X = Cl
c: R = Me; X = Br
d: R = Et; X = Br
1a, 1b, 1c, 1d
Ph2
P
PPh2
X
Pd
N
S
Me
N
NHR
4a, 4b, 4c, 4d
Scheme 1. (i) Li2[PdCl4]/NaAcO/MeOH; Pd(AcO)2/AcOH; (ii) Ph2PCH2PPh2/HCl(aq)/acetone/1:4; (iii) Ph2PCH2PPh2/acetone/1:2; (iv) Ph2PCH2PPh2/
acetone/1.4; (v) HCl(aq)/acetone.

2850
J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
clear from the absence of the four proton ABCD spin sys-
tem of the ortho-substituted phenyl ring; in the spectra of
the complexes only three resonances were observed, which
were unambiguously assigned to the H3, H4 and H5 pro-
tons (see Section 6).
trans to the phenyl carbon atom in accordance with the
higher trans influence of the latter with respect to the
C@N nitrogen atom [30]. The HC@N resonance was only
coupled to the 31P nucleus trans to nitrogen. This was con-
firmed by selective decoupling experiments on the 31P
atoms. Alternatively, compounds 2a–2d could be prepared
by stirring a mixture of 4a–4d and concentrated hydrochlo-
ric acid at room temperature. Unfortunately, the yields
were rather low in these cases, ca. 25%, and the final prod-
uct contained unreacted starting material, and so far pure
2a–2d could not be made by this additional route.
3. Reactivity of the complexes
The reactions of 1a–1d with Ph2PCH2PPh2 in a 1:4
molar ratio and concentrated hydrochloric acid
gave the hitherto unknown complexes [Pd{2-XC6-
H3C(Me)@NN(H)–C(@S)NHR}(Ph2PCH2PPh2-P,P)](Cl)
2a–2d which were fully characterized (Section 6 and
Scheme 1). Conductivity measurements in dry acetonitrile
showed they were 1:1 electrolytes, with Km values of ca.
130 ohmꢀ1 cm2 molꢀ1. The most noticeable feature of these
compounds was that protonation occurred at the hydrazi-
nic nitrogen atom as shown by a broad resonance signal at
Treatment of the tetranuclear species with Ph2PCH2-
PPh2 in the absence of acid gave dinuclear and mononu-
clear compounds with a bridging or monocoordinate phos-
phine ligand, respectively. Thus, reaction of 1a–1d and the
phosphine in a 1:2 molar ratio produced compounds
[{Pd[2-XC6H3C(Me)@NN@C(S)NHR]}2(l-Ph2PCH2PPh2)]
(3a–3d) as pure air-stable solids, which were completely
characterized (see Section 6). The symmetric nature of
1
ca. 8.80 ppm in the H NMR spectra, and a band assign-
able to the m(C@S) mode at ca. 8.35 cmꢀ1 in the IR spectra.
The 31P–{1H} NMR spectra showed two doublets for the
two non-equivalent phosphorus nuclei. The resonance at
lower frequency was assigned to the phosphorus nucleus
the complexes was evident from the H NMR data, which
1
showed only one set of signals; and consequently, only one
singlet was observed in the 31P–{1H} spectra showing two
equivalent phosphorus nuclei, with a d value pointing
Fig. 1. An ORTEP drawing of the molecular structure for 1b with the labelling scheme (50% probability). Hydrogen atoms have been omitted for clarity.
˚
Selected bond lengths (A) and angles (ꢁ): Pd(1)–N(1) 1.989(4), Pd(1)–C(1) 2.007(5), Pd(1)–S(1)#1 2.3186(16), Pd(1)–S(1) 2.3551(16), S(1)–C(8) 1.792(6),
N(1)–C(7) 1.316(6), N(1)–N(2) 1.385(6), N(2)–C(8) 1.308(6), C(6)–C(7) 1.469(8); N(1)–Pd(1)–C(1) 80.9(2), N(1)–Pd(1)–S(1)#1 177.11(13), C(1)–Pd(1)–
S(1)#1 96.44(17), N(1)–Pd(1)–S(1) 84.10(13), C(1)–Pd(1)–S(1) 164.66(17), S(1)#1–Pd(1)–S(1) 98.52(4).

J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
2851
towards a phosphorus trans to nitrogen geometry [31,32].
4.1.1. [Pd{2-XC6H3C(Me)@NN@C(S)NHEt}]4
(X = Cl, 1b; X = Br, 1d)
The H5 resonance was low frequency shifted by ca.
1.5 ppm, showing coupling to the 31P nucleus, also sustain-
ing a P trans to N arrangement [33].
The palladium(II) atoms in each structure are in
slightly distorted square-planar environments (rms =
0.0132 1b and rms = 0.0132 1d), with small deviations
from the coordination plane ( 0.0412 1b and 0.0437
1d), and are associated to two fused five-membered che-
late rings: the C,N metallacycle and the N,S-chelate moi-
ety, as a consequence of bonding to a terdentate C,N,S
ligand. An eight-membered ring of palladium and sulfur
atoms, with alternating Pd–Sbridging and Pd–Schelating
bonds compiles the central part of the molecule; the other
two coordination positions at the metal are occupied by a
phenyl carbon atom and the nitrogen atom of the C@N
group (Figs. 1 and 2).
Reaction of 1a–1d with Ph2PCH2PPh2 in a 1:4 molar
ratio gave the air-stable compounds [Pd{2-XC6H3C(Me)@
NN@C(S)NHR}(Ph2PCH2PPh2-P)] (4a–4d). Characteris-
tic microanalytical and spectroscopic data are given in
Section 6. Even when excess diphosphine was used, only
cleavage of the Pd–Sbridging bonds was produced, therefore
yielding species with coordination of the phosphine to the
metal atom only through one phosphorus atom. The two
doublets in the 31P–{1H} spectra were assigned to the two
non-equivalent phosphorus nuclei with the signal for the
phosphorus nucleus bonded to the metal center at higher
frequency. The proton part of the PCH2P ABXY spin
system appeared as an apparent doublet at ca. 3.2 ppm.
The angles between adjoining atoms in the coordination
sphere are close to the theoretical value of 90ꢁ; with the
most noteworthy strain in the C(1)–Pd(1)–N(1) values
due to chelation of the ligand [22,23] [80.9(2)ꢁ 1b;
4. Structural studies
˚
˚
81.4(3)ꢁ 1d]. The Pd–C [2.007(5) A 1b, 1.990(7) A 1d] and
˚ ˚
4.1. Crystal structures of complexes 1b, 1d, 4c and 4d
Pd–N [1.989(4) A 1b, 1.988(6) A 1d] bond lengths are
˚
˚
shorter than the expected values of 2.081 A and 2.01 A
[34], respectively, probably induced by partial multiple-
bond character [19,35]. The differing trans influence of
the phenyl carbon and the azomethine nitrogen atoms is
Suitable crystals were grown by slowly evaporating
chloroform/n-hexane solutions. The crystal structures are
shown in Figs. 1–4. Crystal data are given in Table 1.
Fig. 2. An ORTEP drawing of the molecular structure for 1d with the labelling scheme (50% probability). Hydrogen atoms have been omitted for clarity.
˚
Selected bond lengths (A) and angles (ꢁ): Pd(1)–N(1) 1.988(6), Pd(1)–C(1) 1.990(7), Pd(1)–S(1)#1 2.315(2), Pd(1)–S(1) 2.355(2), S(1)–C(8) 1.794(7), N(1)–
C(7) 1.330(8), N(1)–N(2) 1.381(8), N(2)–C(8) 1.304(8); N(1)–Pd(1)–C(1) 81.4(3), N(1)–Pd(1)–S(1)#1 177.48(17), C(1)–Pd(1)–S(1) 96.2(2), N(1)–Pd(1)–S(1)
84.01(19), C(1)–Pd(1)–S(1)#1 165.0(2), S(1)#1–Pd(1)–S(1) 98.27(7).

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J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
Fig. 3. An ORTEP drawing of the molecular structure for 4c with the labelling scheme (50% probability). Hydrogen atoms and solvent molecules have
˚
been omitted for clarity. Selected bond lengths (A) and angles (ꢁ): Pd(1)–N(1) 2.018(2), Pd(1)–C(1) 2.026(3), Pd(1)–P(1) 2.2626(8), Pd(1)–S(1) 2.3192(9),
P(1)–C(18) 1.823(3), P(1)–C(12) 1.828(3), P(1)–C(11) 1.838(3), S(1)–C(8) 1.754(3), N(1)–C(7) 1.303(4), N(1)–N(2) 1.388(3), N(2)–C(8) 1.307(4), C(6)–C(7)
1.472(4); N(1)–Pd(1)–C(1) 80.77(7), N(1)–Pd(1)–P(1) 177.29(8), C(1)–Pd(1)–P(1) 97.94(2), N(1)–Pd(1)–S(1) 83.23(7), C(1)–Pd(1)–S(1) 163.95(9), P(1)–
Pd(1)–S(1) 97.99(3).
put forward in the distinct values of the Pd–Sbridging and
Pd–Schelating distances [Pd(1)–S(1) 2.3551(16) A, Pd(1)–
As for the bond distances and the angles at palladium,
the data observed for both structures show analogous val-
ues that are in accordance with the known theoretical data,
with the most noticeable difference being in the Pd–N
bond, which displays a marked lengthening due to the trans
˚
˚
˚
S(1)#1 2.3186(16) A 1b; Pd(1)–S(1) 2.355(2) A, Pd(1)–
˚
˚
S(1)#1 2.315(2) A 1d]. The S(1)–C(8) [1.792(6) A 1b;
˚
˚
˚
1.794(7) A 1d] and N(2)–C(8) [1.308(6) A 1b; 1.304(8) A
1d] distances, are consistent with increased single- and dou-
ble-bond character, respectively, in the deprotonated form.
˚
influence of the phosphine ligand [Pd(1)–N(1), 2.018(2) A
˚
4c, 2.015(3) A, 4d], and the somewhat diminished C(1)–
˚
˚
The Pd–Pd lengths of 3.3725(7) A 1b, and 3.3596(16) A 1d,
Pd(1)–N(1) angle, 80.77(7)ꢁ 4c, 80.54(14)ꢁ 4d (vide supra).
The palladium coordination plane [Pd(1), C(1), N(1),
S(1)], and the P(1)C(11)P(2), 4c, and P(1)C(12)P(2), 4d,
planes are at angles of 68.72ꢁ and 69.70ꢁ, respectively.
preclude any Pd–Pd interactions.
4.1.2. [Pd{2-BrC6H3C(Me)@NN@C(S)NHR}-
(Ph2PCH2PPh2-P)] (R: Me 4c; Et 4d)
The crystals consist of discrete molecules and CHCl3,
separated by normal van der Waals distances. The palla-
dium coordination sphere is defined by an assorted set
of four atoms arising from a terdentate C,N,S thiosemi-
carbazone and a g1-diphosphine: the aryl C(1) carbon,
the imine N(1) nitrogen, the thioamide S(1) sulfur and
the phosphorus P(1) atoms, in a slightly distorted
square-planar coordination, [N(1), S(1), C(1), P(1), plane
5. Conclusions
We have shown that thiosemicarbazone ligands
may yield tetranuclear palladacycles with two distinct
Pd–Sbridging and Pd–Schelating bonds; the strength of the
latter hinders opening of the coordination ring, PdNNCS,
bearing the Pd–Schelating bond, and upon reaction with
Ph2PCH2PPh2, in the absence of acid, only dinuclear and
mononuclear compounds were obtained with bridging or
monodentate phosphine ligands, respectively, and with
the thiosemicarbazone ligand as a terdentate ligand
[C,N,S]. However, when concentrated hydrochloric acid
˚
1] (r.m.s. = 0.0064 A) 4c, (Fig. 3), [N(1), S(1), C(1), P(1),
˚
plane 1] (r.m.s. = 0.0153 A) 4d, (Fig. 4), from which the
˚
palladium atom deviates by
0.0328 A 4d.
0.0382 A 4c and
˚

J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
2853
Fig. 4. An ORTEP drawing of the molecular structure for 4d with the labelling scheme (50% probability). Hydrogen atoms and solvent molecules have
˚
been omitted for clarity. Selected bond lengths (A) and angles (ꢁ): Pd(1)–N(1) 2.015(3), Pd(1)–C(1) 2.022(4), Pd(1)–P(1) 2.2659(10), Pd(1)–S(1) 2.3231(11),
S(1)–C(8) 1.746(4), P(1)–C(13) 1.833(4), P(1)–C(19) 1.819(4), P(1)–C(12) 1.834(4), N(1)–C(7) 1.302(5), N(1)–N(2) 1.396(4), N(2)–C(8) 1.307(5), C(6)–C(7)
1.467(5); N(1)–Pd(1)–C(1) 80.54(14), N(1)–Pd(1)–P(1) 177.26(9), C(1)–Pd(1)–P(1) 98.33(12), N(1)–Pd(1)–S(1) 83.51(9), C(1)–Pd(1)–S(1) 164.05(12), P(1)–
Pd(1)–S(1) 97.59(4).
was added to the reaction mixture, cleavage of the Pd–
Schelating bond was produced, with protonation of the
thiosemicarbazone and subsequent chelation of the diphos-
phine ligand, yielding the new thiosemicarbazone pallada-
cycles as 1:1 electrolytes. These could also be made,
although impure, by treatment of the compounds with
g1-diphosphine with hydrochloric acid.
Nujol mulls or KBr discs with Perkin–Elmer 1330, IR-
FT Mattson Model Cygnus-100 and Bruker Model IFS-
66V spectrophotometers. NMR spectra were obtained
as CDCl3 solutions and referenced to SiMe4 (1H) or
H3PO4 (31P–{1H}) and were recorded with Bruker
AMX 300, AMX 500 and WM250 spectrometers. All
chemical shifts are reported downfield from standards.
The FAB mass spectra were recorded with a Fisons Qua-
tro mass spectrometer with a Cs ion gun; 3-nitrobenzyl
alcohol was used as the matrix. Conductivity measure-
ments were made on a CRISON GLP 32 conductivimeter
using 10ꢀ3 mol dmꢀ3 solutions in dry acetonitrile.
6. Experimental
6.1. General procedures
Solvents were purified by standard methods [36].
Chemicals were reagent grade. Lithium tetrachloropalla-
date was prepared in situ by treatment of palladium(II)
chloride with lithium chloride in methanol. Palladium(II)
acetate and palladium(II) chloride were purchased from
Alfa Products. The diphosphine Ph2PCH2PPh2 (dppm)
was purchased from Aldrich-Chemie. Microanalyses were
6.2. Syntheses
6.2.1. Preparation of thiosemicarbazone 2-ClC6H4C(Me)@
NN(H)C(@S)NHMe (a)
20-Chloroacetophenone (147 mg, 9.51 mmol) and hydro-
chloric acid (35%, 0.65 cm3) were added to a suspension of
4-methyl-3-thiosemicarbazide (100 mg, 9.51 mmol) in water
(25 cm3) to give a clear solution, which was stirred at room
temperature for 4 h. The white solid that precipitated was
´
carried out at the Servicio de Analisis Elemental at the
Universidad of Santiago using a Carlo Erba Elemental
Analyzer Model EA1108. IR spectra were recorded as

2854
J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
filtered off, washed with cold water and dried in air. Yield:
209 mg, 91%. Anal. C10H12ClN3S (241.7 g/mol) requires C,
49.7; H, 5.0; N, 17.4; S, 13.3. Found: C, 49.4; H, 5.0; N,
17.4; S, 13.2%. IR (cmꢀ1): m(N–H) 3357s, 3239m; m(C@N)
red solution of palladium(II) chloride (200 mg, 1.13 mmol)
and lithium chloride (96 mg, 2.26 mmol) in methanol
(40 cm3). The mixture was stirred for 48 h at room temper-
ature under nitrogen. The yellow precipitate which formed
was filtered off, washed with methanol and dried in vacuo.
Yield: 346 mg, 89%. Anal. C40H40Cl4N12Pd4S4 (1384.6 g/
mol) requires C, 34.7; H, 2.9; N, 12.1; S, 9.3. Found: C,
34.6; H, 2.9; N, 11.9; S, 9.2%. IR (cmꢀ1): m(N–H) 3425s,
m(C@N) 1558s. 1H NMR (CDCl3, d ppm, J Hz): 7.44
1
1591w; m(C@S) 834m. H NMR (CDCl3, d ppm, J Hz):
8.62 (s, 1H, NH), 7.53 (br, 1H, NHMe), 7.36 (dd, 1H, H6,
4
3J(H6H5) = 7.8, J(H6H4) = 1.4), 7.26 (m, 3H, H3, H4,
H5), 3.15 (d, 3H, NHMe, 3J(HH) = 4.6), 2.22 (s, 3H,
MeC@N). FAB-MS: m/z 242 [M]+.
3
4
(dd, 1H, H5, J(H5H4) = 7.9, J(H5H3) = 0.9), 6.96 (dd,
1H, H3, 3J(H3H4) = 7.9, 4J(H3H5) = 0.9), 6.84 (t, 1H,
H4, 3J(H4H3) = 7.9, 3J(H4H5) = 7.9), 5.07 (q, 1H,
NHMe, 3J(NH–H) = 4.6), 2.98 (d, 3H, NMe, 3J(H–
NH) = 4.6), 2.22 (s, 3H, MeC@N). FAB-MS: m/z 1384
[M]+.
Method 2. Ligand a (226 mg, 0.94 mmol, 5% excess) and
palladium(II) acetate (200 mg, 0.89 mmol) were added to
glacial acetic acid (45 cm3) to give a clear solution, which
was heated to 60 ꢁ C under nitrogen for 24 h. After cooling
to room temperature, the yellow precipitate which formed
was filtered off, washed with ethanol and dried in vacuo.
Yield: 294 mg, 95%.
6.2.2. Thiosemicarbazones (b–d)
These were synthesized following a similar procedure.
6.2.2.1. 2-ClC6H4C(Me)@NN(H)C(@S)NHEt (b).
Yield: 165 mg, 77%. Anal. C11H14ClN3S (255.8 g/mol)
requires C, 51.7; H, 5.5; N, 16.4; S, 12.5. Found: C, 51.5;
H, 5.5; N, 16.3; S, 12.5%. IR (cmꢀ1): m(N–H) 3367s,
1
3201m; m(C@N) 1592w; m(C@S) 827m. H NMR (CDCl3,
d ppm, J Hz): 8.59 (s, 1H, NH), 7.53 (br, 1H, NHEt),
7.37 (m, 4H, H6, H3, H4, H5), 3.72 (dq, 2H, NHCH2CH3,
3J(HH) = 7.4 Hz, 3J(H–NH) = 5.5), 2.27 (s, 3H, MeC@N),
3
1.26 (t, 3H, NHCH2CH3, J(HH) = 7.4). FAB-MS: m/z
256 [M]+.
6.2.4. Compounds 1b–1d
These were synthesized following a similar procedure.
6.2.2.2. 2-BrC6H4C(Me)@NN(H)C(@S)NHMe (c).
Yield: 233 mg, 86%. Anal. C10H12BrN3S (286.2 g/mol)
requires C, 42.0; H, 4.2; N, 14.7; S, 11.2. Found: C, 41.8;
H, 4.3; N, 14.9; S, 11.0%. IR (cmꢀ1): m(N–H) 3357s, 3179s;
m(C@N) 1586w; m(C@S) 833m. 1H NMR (CDCl3, d ppm, J
6.2.4.1. [Pd{2-ClC6H3C(Me)@NN@C(S)NHEt}]4 (1b).
Method 1. Yield: 347 mg, 85%. Anal. C44H48Cl4N12Pd4S4
(1440.7 g/mol) requires C, 36.7; H, 3.4; N, 11.7; S, 8.9.
Found: C, 36.6; H, 3.3; N, 11.8; S, 9.1%. IR (cmꢀ1):
3
Hz): 8.63 (br, 1H, NH), 7.61 (dd, 1H, H6, J(H6H5) = 7.9,
1
4J(H4H6) = 1.4), 7.54 (br, 1 H, NHMe), 7.36 (dd, 1H, H3,
3J(H3H4) = 7.9 Hz, 4J(H3H5) = 1.4), 7.30 (td, 1H, H4,
3J(H4H3) = 7.9 Hz, 3J(H4H5) = 7.9 Hz, 4J(H4H6) = 1.4),
7.25 (ddd, 1H, H5, 3J(H6H5) = 7.9, 3J(H5H4) = 7.9,
m(N–H) 3429m, m(C@N) 1559s. H NMR (CDCl3, d ppm,
J
Hz):
7.45
(dd,
1H,
H5,
3J(H5H4) = 7.9,
4J(H5H3) = 0.9), 6.97 (dd, 1H, H3, 3J(H3H4) = 7.9,
4J(H3H5) = 0.9), 6.84 (t, 1H, H4, 3J(H4H3) = 7.9,
3J(H4H5) = 7.9), 5.08 (t, 1H, NHEt, 3J(NH–H) = 5.5),
3.40 (m, 2H, NHCH2CH3), 2.19 (s, 3H, MeC@N), 1.24
3
4J(H5H3) = 1.4), 3.21 (d, 3H, NHMe, J(HH) = 4.6), 2.27
(s, 3H, MeC@N). FAB-MS: m/z 287 [MH]+.
3
(t, 3H, NHCH2CH3, J(HH) = 7.4). FAB-MS: m/z 1441
[M]+.
6.2.2.3. 2-BrC6H4C(Me)@NN(H)C(@S)NHEt (d).
Yield: 204 mg, 81%. Anal. C11H14BrN3S (300.2 g/mol)
requires C, 44.0; H, 4.7; N, 14.0; S, 10.7. Found: C, 43.9;
H, 4.7; N, 14.2; S, 10.5%. IR (cmꢀ1): m(N–H) 3367s,
Method 2. Yield: 284 mg, 89%.
6.2.4.2. [Pd{2-BrC6H3C(Me)@NN@C(S)NHMe}]4 (1c).
Method 1. Yield: 365 mg, 83%. Anal. C40H40Br4N12Pd4S4
(1562.4 g/mol) requires C, 30.8; H, 2.6; N, 10.8; S, 8.2.
Found: C, 30.7; H, 2.4; N, 10.6; S, 8.1%. IR (cmꢀ1):
1
3208m; m(C@N) 1588w; m(C@S) 826m. H NMR (CDCl3,
d ppm, J Hz): 8.60 (br, 1H, NH), 7.61 (dd, 1H, H6,
3J(H6H5) = 7.9, 4J(H4H6) = 1.4), 7.54 (br, 1H, NHEt),
1
m(N–H) 3417m, m(C@N) 1561s. H NMR (CDCl3, d ppm,
3
4
7.37 (dd, 1H, H3, J(H3H4) = 7.9, J(H3H5) = 1.4), 7.31
J
Hz):
7.49
(dd,
1H,
H5,
3J(H5H4) = 7.9,
3
3
4
(td, 1H, H4, J(H4H3) = 7.9, J(H4H5) = 7.9, J(H4H6)
= 1.4), 7.25 (ddd, 1H, H5, J(H6H5) = 7.9, J(H5H4) =
7.9, J(H5H3) = 1.4), 3.72 (dq, 2H, NHCH2CH3, J(HH)
= 7.4, 3J(H–NH) = 5.5), 2.26 (s, 3H, MeC@N), 1.25 (t,
3H, NHCH2CH3, 3J(HH) = 7.4 Hz). FAB-MS: m/z 300
[M]+.
4J(H5H3) = 0.9), 7.22 (dd, 1H, H3, 3J(H3H4) = 7.9,
4J(H3H5) = 0.9), 6.75 (t, 1H, H4, 3J(H4H3) = 7.9,
3
3
4
3
3J(H4H5) = 7.9), 5.08 (q, 1H, NHMe, J(NH–H) = 4.6),
3
2.98 (d, 3H, NHMe, 3J(H–NH) = 4.6), 2.24 (s, 3H,
MeC@N). FAB-MS: m/z 1563 [MH]+.
Method 2. Yield: 283 mg, 81%.
6.2.3. Preparation of [Pd{2-ClC6H3C(Me)@NN@C(S)-
NHMe}]4 (1a)
Method 1. Ligand a (286 mg, 1.18 mmol, 5% excess) and
sodium acetate (185 mg, 2.26 mmol) were added to a stir-
6.2.4.3. [Pd{2-BrC6H3C(Me)@NN@C(S)NHEt}]4 (1d).
Method 1. Yield: 353 mg, 77%. Anal. C44H48Br4N12Pd4S4
(1618.5 g/mol) requires C, 32.7; H, 3.0; N, 10.4; S, 7.9.
Found: C, 32.5; H, 2.9; N, 10.3; S, 8.0%. IR (cmꢀ1):

J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
2855
Table 1
Crystal data and structure refinement data for 1b, 1d, 4c and 4d
Compound
1b
1d
4c
4d
Empirical formula
Formula weight
Temperature (K)
C44H48Cl4N12Pd4S4
1440.58
293(2)
C11H12BrN3PdS
404.61
293(2)
C36H33BrCl3N3P2PdS
894.31
293(2)
C36H34BrN3P2PdS
788.97
293(2)
˚
Wavelength (A)
0.71073
0.71073
0.71073
0.71073
Crystal system
Space group
Unit cell dimensions
tetragonal
I41/a
tetragonal
I41/a
triclinic
triclinic
ꢀ
ꢀ
P1
P1
˚
a (A)
17.196(4)
17.196(4)
16.917(5)
17.249(10)
17.249(10)
17.228(11)
10.5638(1)
11.8823(1)
15.9816(1)
88.569(1)
80.760(1)
69.257(1)
1850.56(3)
2
10.7529(5)
11.9801(6)
15.9998(8)
89.3630(10)
80.5180(10)
69.6490(10)
1903.67(16)
2
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
Volume (A )
5002(2)
4
1.913
1.843
2848
0.28 · 0.24 · 0.24
5126(5)
16
2.097
4.709
Z
Density (calculated) (Mg/m3)
Absorption coefficient (mmꢀ1
F(000)
1.605
1.971
896
1.376
1.703
796
)
3136
Crystal size (mm3)
0.36 · 0.32 · 0.20
2.36–25.82
ꢀ8/h/21,
ꢀ14/k/17,
ꢀ21/l/17
5194
2484 [0.1207]
100.0
multi-scan
0.309 and 0.200
0.60 · 0.50 · 0.50
1.29–28.28
ꢀ8/h/14,
ꢀ8/k/15,
ꢀ19/l/21
12634
8738 [0.0148]
95.3
multi-scan
0.373 and 0.319
0.40 · 0.30 · 0.20
1.29–28.29
ꢀ10/h/14,
ꢀ13/k/15,
ꢀ18/l/21
13248
9102 [0.0240]
96.1
multi-scan
0.711 and 0.547
h Range for data collection (ꢁ) 2.37–29.96
Index ranges
0/h/24,
ꢀ24/k/0,
0/l/23
Reflections collected
Independent reflections [Rint
Completeness to h (%)
Absorption correction
Maximum and
3849
3626 [0.0633]
99.8
multi-scan
0.643 and 0.603
]
minimum transmission
Refinement method
full-matrix
least-squares on F2
3626/0/157
0.935
full-matrix
least-squares on F2
2484/0/156
0.956
full-matrix
least-squares on F2
8738/0/434
1.026
full-matrix
least-squares on F2
9102/12/400
1.038
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
R1 = 0.0424, wR2 = 0.0755 R1 = 0.0358, wR2 = 0.0690 R1 = 0.0394, wR2 = 0.0898 R1 = 0.0506, wR2 = 0.1024
R1 = 0.2227, wR2 = 0.1026 R1 = 0.1615, wR2 = 0.0926 R1 = 0.0534, wR2 = 0.0982 R1 = 0.0823, wR2 = 0.1148
Largest differential
peak and hole (e A
0.543 and ꢀ0.790
0.557 and ꢀ0.660
0.757 and ꢀ0.642
0.595 and ꢀ0.530
ꢀ3
˚
)
m(N–H) 3425m, m(C@N) 1557s. 1H NMR (CDCl3, d ppm, J
Hz): 7.50 (dd, 1H, H5, J(H5H4) = 7.9, J(H5H3) = 0.9),
54.7; H, 4.2; N, 5.5; S, 4.1%. IR (cmꢀ1): m(N–H) 3440s,
3210; m(C@N) 1557m. 1H NMR(CDCl3, d ppm, J Hz):
3
4
3
4
3
4
7.22 (dd, 1H, H3, J(H3H4) = 7.9, J(H3H5) = 0.9), 6.75
6.69 (dd, 1H, H3, J(H3H4) = 7.9, J(H3H5) = 0.9), 6.21
(t, 1H, H4, 3J(H4H3) = 7.9, 3J(H4H5) = 7.9), 6.05 (dd,
1H, H5, 3J(H5H4) = 7.9, 4J(H5H3) = 0.9), 4.82 (q, 1H,
NHMe, 3J(NH–H) = 5.1), 3.61 (d, 1H, PCH2P,
2J(HP) = 9.2), 3.57 (d, 1H, PCH2P, 2J(HP) = 9.2), 3.01
3
3
(t, 1H, H4, J(H4H3) = 7.9, J(H4H5) = 7.9), 5.09 (t, 1H,
NHEt, 3J(NH–H) = 5.5), 3.40 (dq, 2H, NHCH2CH3,
3J(HH) = 7.4, 3J(H–NH) = 5.5), 2.21 (s, 3H, MeC@N),
3
1.24 (t, 3H, NHCH2CH3, J(HH) = 7.4). FAB-MS: m/z
1620 [MH]+.
(d, 3H, NHMe, J(H–NH) = 5.1), 2.69 (s, 3H, MeC@N).
3
Method 2. Yield: 302 mg, 84%.
31P–{1H} (CDCl3, d ppm, J Hz): 24.4 (d, 1P, 2J(PP) =
2
13.1), 22.8 (d, 1P, J(PP) = 13.3). Km = 133.1 ohmꢀ1 cm2
6.2.5. [(Pd{2-ClC6H3C(Me)@NN@C(S)NHMe})-
(Ph2PCH2PPh2)-P,P](Cl) (2a)
molꢀ1 (in acetonitrile).
Compounds 2b–2d were synthesized similarly.
The diphosphine Ph2PCH2PPh2 (17.0 mg, 0.044 mmol)
was added to a suspension of complex 1a (15 mg,
0.011 mmol) in acetone (15 cm3), and the mixture was trea-
ted with two drops of concentrated hydrochloric acid
(35%). The resulting solution was stirred for 4 h and the
yellow solid formed was filtered off and dried in vacuo.
Yield: 19.6 mg, 42%. Anal. C35H33Cl2N3P2PdS (767.0 g/
mol) requires C, 54.8; H, 4.3; N, 5.5; S, 4.2. Found: C,
6.2.6. [(Pd{2-ClC6H3C(Me)@NN@C(S)NHEt})-
(Ph2PCH2PPh2)-P,P](Cl) (2b)
Yield: 15.4 mg, 34%. Anal. C36H35Cl2N3P2PdS (781.0 g/
mol) requires C, 55.4; H, 4.5; N, 5.4; S, 4.1. Found: C, 55.4;
H, 4.4; N, 5.4; S, 4.0%. IR (cmꢀ1): m(N–H) 3432s; m(C@N)
1558m. 1H NMR (CDCl3, d ppm, J Hz): 6.77 (dd, 1H, H3,
3J(H3H4) = 7.9, 4J(H3H5) = 1.4), 6.32 (t, 1H, H4,

2856
J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
3J(H4H3) = 7.9, 3J(H4H5) = 7.9), 6.02 (ddd, 1H, H5,
3J(NH–H) = 5.1), 3.73 (t, 1H, PCH2P, 2J(HP) = 10.2),
3.01 (d, 3H, NHMe, 3J(H–NH) = 5.1), 2.69 (s, 3H,
MeC@N). 31P–{1H} NMR (CDCl3, d ppm): d = 23.7s.
Compounds 3b–3d were prepared analogously.
4
4
3J(H5H4) = 7.9 Hz, J(H5P) = 5.1, J(H5H3) = 1.4), 4.81
(t, 1H, NHEt, 3J(NH–H) = 5.5), 3.60 (d, 1H, P CH2P,
2J(HP) = 9.2), 3.56 (d, 1H, PCH2P, 2J(HP) = 9.2), 3.42
(dq,
2H,
NHCH2CH3,
3J(HH) = 7.4 Hz,
3J(H–
NH) = 5.5), 2.67 (s, 3H, MeC@N), 1.20 (t, 3H,
NHCH2CH3, 3J(HH) = 7.4). 31P–{1H} NMR (CDCl3,
d ppm, J Hz): 24.3 (d, 1P, 2J(PP) = 13.1), 22.7 (d,
1P, 2J(PP) = 13.1). Km = 132.7 ohmꢀ1 cm2 molꢀ1 (in
acetonitrile).
6.2.10. [(Pd{2-ClC6H3C(Me)@NN@C(S)NHEt})2-
(l-Ph2PCH2PPh2)] (3b)
Yield: 15.4 mg, 34%. Anal. C47H46Cl2N6P2Pd2S2
(1104.7 g/mol) requires C, 51.1; H, 4.2; N, 7.6; S, 5.8.
Found: C, 51.3; H, 4.5; N, 7.5; S, 5.7%. IR (cmꢀ1): m(N–
1
H) 3432s; m(C@N) 1558m. H NMR (CDCl3, d ppm, J
3
4
6.2.7. [(Pd{2-BrC6H3C(Me)@NN@C(S)NHMe})-
(Ph2PCH2PPh2)-P,P](Cl) (2c)
Hz): 6.77 (dd, 1H, H3, J(H3H4) = 7.9, J(H3H5) = 1.4),
6.32 (t, 1H, H4, 3J(H4H3) = 7.9, 3J(H4H5) = 7.9), 6.02
Yield: 33.0 mg, 74%. Anal. C35H33BrClN3P2PdS
(811.5 g/mol) requires C, 51.8; H, 4.1; N, 5.2; S, 4.0.
Found: C, 51.6; H, 4.0; N, 5.1; S, 3.9%. IR (cmꢀ1): m(N–
(ddd,
1H,
H5,
3J(H5H4) = 7.9,
4J(H5P) = 5.1,
4J(H5H3) = 1.4), 4.81 (t, 1H, NHEt, 3J(NH–H) = 5.5),
3.58 (t, 1H, PCH2P, 2J(HP) = 9.2), 3.42 (dq, 2H,
NHCH2CH3, 3J(HH) = 7.4, 3J(H–NH) = 5.5), 2.67 (s,
1
H) 3426m; m(C@N) 1559s. H NMR (CDCl3, d ppm, J
3
3
Hz): 7.01 (d, 1H, H3, J(H3H4) = 7.9), 6.22 (t, 1H, H4,
3H, MeC@N), 1.20 (t, 3H, NHCH2CH3, J(HH) = 7.4).
3J(H4H3) = 7.9 Hz, 3J(H4H5) = 7.9), 6.10 (m, 1H, H5),
4.83 (br, 1H, NHMe), 3.72 (d, 1H, PCH2P,
2J(HP) = 9.2), 3.68 (d, 1H, PCH2P, 2J(HP) = 9.2), 2.98
31P–{1H} NMR (CDCl3, d ppm): 22.9s.
6.2.11. [(Pd{2-BrC6H3C(Me)@NN@C(S)NHMe})2-
(l-Ph2PCH2PPh2)] (3c)
3
(d, 3H, NHMe, J(H–NH) = 5.1), 2.70 (s, 3H, MeC@N).
31P–{1H} NMR (CDCl3, d ppm, J Hz): 24.1 (d, 1P,
2J(PP) = 13.1), 22.7 (d, 1P, 2J(PP) = 13.1). Km = 125.6
ohmꢀ1 cm2 molꢀ1 (in acetonitrile).
Yield: 33.0 mg, 74%. Anal. C45H42Br2N6P2Pd2S2
(1165.6 g/mol) requires C, 46.4; H, 3.6; N, 7.2; S, 5.5.
Found: C, 46.1; H, 3.7; N, 6.9; S, 5.4%. IR (cmꢀ1): m(N–
1
H) 3426m; m(C@N) 1559s. H NMR (CDCl3, d ppm, J
3
6.2.8. [(Pd{2-BrC6H3C(Me)@NN@C(S)NHEt})-
(Ph2PCH2PPh2)-P,P](Cl) (2d)
Yield: 13.2 mg, 30%. Anal. C36H35BrClN3P2PdS
(825.5 g/mol) requires C, 52.4; H, 4.3; N, 5.1; S, 3.9.
Found: C, 52.3; H, 4.3; N, 5.0; S, 3.9%. IR (cmꢀ1):
m(N–H) 3428m; m(C@N) 1557m. 1H NMR (CDCl3, d
Hz): 7.01 (d, 1H, H3, J(H3H4) = 7.9), 6.22 (t, 1H, H4,
3J(H4H3) = 7.9 Hz, 3J(H4H5) = 7.9), 6.10 (m, 1H, H5),
4.83 (br, 1H, NHMe), 3.71 (t, 1H, PCH2P, 2J(HP) = 10.2),
2.98 (d, 3H, NHMe, 3J(H–NH) = 5.1), 2.70 (s, 3H,
MeC@N). 31P–{1H} NMR (CDCl3, d ppm): 23.6s.
ppm,
J
Hz): 7.01 (dd, 1H, H3, 3J(H3H4) = 7.9,
6.2.12. [(Pd{2-BrC6H3C(Me)@NN@C(S)NHEt})2-
(l-Ph2PCH2PPh2)] (3d)
4J(H3H5) = 0.9), 6.22 (t, 1H, H4, 3J(H4H3) = 7.9 Hz,
3J(H4H5) = 7.9), 6.10 (m, 1H, H5), 4.82 (br, 1H, NHEt),
Yield: 13.2 mg, 30%. Anal. C47H46Br2N6P2Pd2S2
(1193.6 g/mol) requires C, 47.3; H, 3.9; N, 7.0; S, 5.4.
Found: C, 47.1; H, 3.9; N, 6.7; S, 5.2%. IR (cmꢀ1): m(N–
2
3.60 (d, 1H, PCH2P, J(HP) = 9.2), 3.56 (d, 1H, PCH2P,
2J(HP) = 9.2), 3.41 (dq, 2H, NHCH2CH3, 3J(HH) =
7.4 Hz, 3J(H–NH) = 5.5), 2.68 (s, 3H, MeC@N), 1.20
(t, 3H, NHCH2CH3, 3J(HH) = 7.4). 31P–{1H} NMR
1
H) 3428m; m(C@N) 1557m. H NMR (CDCl3, d ppm, J
3
4
Hz): 7.01 (dd, 1H, H3, J(H3H4) = 7.9 Hz, J(H3H5) =
0.9), 6.22 (t, 1H, H4, 3J(H4H3) = 7.9, 3J(H4H5) = 7.9),
6.10 (m, 1H, H5), 4.82 (br, 1H, NHEt), 3.58 (t, 1H, PCH2P,
2
(CDCl3, d ppm, J Hz): 24.2 (d, 1P, J(PP) = 13.7), 22.8
(d, 1P, 2J(PP) = 14.5). Km = 130.2 ohmꢀ1 cm2 molꢀ1 (in
3
acetonitrile).
2J(HP) = 9.2), 3.41 (dq, 2H, NHCH2CH3, J(HH) = 7.4,
3JH–NH = 5.5), 2.68 (s, 3H, MeC@N), 1.20 (t, 3H,
NHCH2CH3, 3J(HH) = 7.4). 31P–{1H} NMR (CDCl3, d
ppm): 23.7s.
6.2.9. [(Pd{2-ClC6H3C(Me)@NN@C(S)NHMe})2-
(l-Ph2PCH2PPh2)] (3a)
The diphosphine Ph2PCH2PPh2 (17.8 mg, 0.046 mmol)
was added to a suspension of complex 1a (30 mg,
0.023 mmol) in acetone (15 cm3). The mixture was stirred
for 4 h. and the resulting yellow solid was filtered off and
dried in vacuo. Yield: 19.6 mg, 42%. Anal.
C45H42Cl2N6P2Pd2S2 (1076.7 g/mol) requires C, 50.2; H,
3.9; N, 7.8; S, 6.0. Found: C, 50.1; H, 3.9; N, 7.7; S,
5.8%. IR (cmꢀ1): m(N–H) 3440s; m(C@N) 1557m. 1H
NMR (CDCl3, d ppm, J Hz): 6.69 (dd, 1H, H3,
3J(H3H4) = 7.9 Hz, 4J(H3H5) = 0.9), 6.21 (t, 1H, H4,
3J(H4H3) = 7.9 Hz, 3J(H4H5) = 7.9), 6.05 (dd, 1H, H5,
3J(H5H4) = 7.9, 4J(H5H3) = 0.9), 4.82 (q, 1H, NHMe,
6.2.13. [Pd{2-ClC6H3C(Me)@NN@C(S)NHMe}-
(Ph2PCH2PPh2-P)] (4a)
The diphosphine Ph2PCH2PPh2 (59.5 mg, 0.155 mmol)
was added to a suspension of complex 1a (50 mg,
0.038 mmol) in acetone (15 cm3). The mixture was stirred
for 4 h. The resulting yellow solid was filtered off and dried
in vacuo. Yield: 130 mg, 78%. Anal. C35H32ClN3P2PdS
(730.5 g/mol) requires C, 57.5; H, 4.4; N, 5.8; S, 4.4.
Found: C, 57.7; H, 4.5; N, 5.5; S, 4.3%. IR (cmꢀ1): m(N–
1
H) 3431m; m(C@N) 1555m. H NMR (CDCl3, d ppm, J
3
Hz): 6.75 (d, 1H, H3, J(H3H4) = 7.9), 6.31 (t, 1H, H4,

J. Martı´nez et al. / Polyhedron 25 (2006) 2848–2858
2857
3
3J(H4H3) = 7.9, J(H4H5) = 7.9), 6.15 (m, 1H, H5), 4.81
reflections [Tmax/Tmin = 0.643/0.603 (1b), 0.309/0.200
(1d), 0.373/0.319 (4c) and 0.711/0.547 (4d)]. The structures
were solved by direct methods and refined by full matrix
least squares on F2. Hydrogen atoms were included in cal-
culated positions and refined using the riding mode. The
structure of 4d contains 1 symmetry related void of
(br, 1H, NHMe), 3.22 (d, 2H, PCH2P, 2J(HP) = 9.5),
2.97 (d, 3H, NHCH3, 3J(H–NH) = 5.1), 2.67 (s, 3H,
MeC@N). 31P–{1H} NMR (CDCl3, d ppm, J Hz): 24.1
(d, 1P, PA, 2J(PP) = 79.8), ꢀ26.7 (d, 1P, PB, 2J(PP) = 79.8).
Compounds 4b–4d were prepared analogously.
3
˚
297.00 A containing unresolvable solvent, this was trea-
6.2.14. [Pd{2-ClC6H3C(Me)@NN@C(S)NHEt}-
(Ph2PCH2PPh2-P)] (4b)
ted using the squeeze method lowering the R1 value by
5.76% [37]. Refinement converged at a final R = 0.0424
(1b), 0.0358 (1d), 0.0394 (4c) and 0.0506 (4d) (observed
data, F), and wR2 = 0.1026 (1b), 0.0926 (1d), 0.0982 (4c)
and 0.1148 (4d) (all unique data, F2), with allowance for
thermal anisotropy of all non-hydrogen atoms. Minimum
and maximum final electron densities: ꢀ0.790 and 0.543
(1b), ꢀ0.660 and 0.ꢀ5537 (1d), ꢀ0.642 and 0.757 (4c),
Yield: 127 mg, 70%. Anal. C36H34ClN3P2PdS (744.6 g/
mol) requires C, 58.1; H, 4.6; N, 5.6; S, 4.3. Found: C,
57.9; H, 4.7; N, 5.7; S, 4.2%. IR (cmꢀ1): m(N–H) 3423s;
m(C@N) 1555m. 1H NMR (CDCl3, d ppm, J Hz): 6.74
(d, 1H, H3, 3J(H3H4) = 7.9), 6.31 (t, 1H, H4,
3
3J(H4H3) = 7.9, J(H4H5) = 7.9), 6.15 (m, 1H, H5), 4.81
˚
(br, 1H, NHEt), 3.41 (m, 2H, NHCH2CH3), 3.24 (d, 2H,
PCH2P, 2J(HP) = 9.5), 2.67 (s, 3H, MeC@N), 1.18 (t,
3H, NHCH2CH3, 3J(HH) = 7.4). 31P–{1H} NMR (CDCl3,
d ppm, J Hz): 23.7 (d, 1P, PA, 2J(PP) = 79.8), ꢀ26.7 (d, 1P,
ꢀ0.530 and 0.595 e A (4d). The structure solutions and
refinements were carried out with the SHELX-97 [38] pro-
gram package.
2
PB, J(PP) = 79.8).
Acknowledgements
6.2.15. [(Pd{2-BrC6H3C(Me)@NN@C(S)NHMe})2-
(Ph2PCH2PPh2-P)] (4c)
We thank the DGESIC (Ministerio de Ciencia y Tec-
´
nologıa) Proyecto BQU2002-04533-C02-01 and the Xunta
Yield: 64.1 mg, 73%. Anal. C35H32BrN3P2PdS (775.0 g/
mol) requires C, 54.2; H, 4.2; N, 5.4; S, 4.1. Found: C,
54.5; H, 4.4; N, 5.3; S, 4.0%. IR (cmꢀ1): m(N–H) 3428m;
m(C@N) 1558m. 1H NMR (CDCl3, d ppm, J Hz): 6.98
(m, 1H, H3), 6.21 (m, 1H, H4), 6.11 (m, 1H, H5), 4.83
(br, 1H, NHMe), 3.23 (d, 2H, PCH2P, 2J(HP) = 9.7),
2.98 (d, 3H, NHCH3, 3J(H–NH) = 5.1), 2.69 (s, 3H,
MeC@N). 31P–{1H} NMR (CDCl3, d ppm, J Hz): 23.9
(d, 1P, PA, 2J(PP) = 79.8), ꢀ26.8 (d, 1P, PB, 2J(PP) = 79.8).
de Galicia, incentive PGIDIT03PXIC20912PN, for finan-
´
cial support. J. Martınez acknowledges a fellowship from
´
the Ministerio de Ciencia y Tecnologıa (Grant No. PB98-
0638-C02-01/02).
Appendix A. Supplementary data
Crystallographic data (excluding structure factors) for
the structures reported in this paper have been deposited
with the Cambridge Crystallographic Data Centre as
supplementary publication numbers 292962 (1b), 292963
(1d), 292965 (4c) 29294 (4d). Copies of the data can be
obtained free of charge on application to CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK (fax: +44 12336033;
e-mail: deposit@ccdc.cam.ac.uk, or on the web
www.ccdc.cam.ac.uk). Supplementary data associated with
this article can be found, in the online version, at
doi:10.1016/j.poly.2006.04.013.
6.2.16. [Pd{2-BrC6H3C(Me)@NN@C(S)NHEt}-
(Ph2PCH2PPh2-P)] (4d)
Yield: 149 mg, 86%. Anal. C36H34BrN3P2PdS (789.0 g/
mol) requires C, 54.8; H, 4.3; N, 5.3; S, 4.1. Found: C,
55.0; H, 4.5; N, 5.0; S, 3.9%. IR (cmꢀ1): m(N–H) 3418m;
m(C@N) 1556m. 1H NMR (CDCl3, d ppm, J Hz): 6.97
(m, 1H, H3), 6.21 (m, 1H, H4), 6.12 (m, 1H, H5), 4.81
(br, 1H, NHEt), 3.42 (m, 2H, NHCH2CH3), 3.24 (d, 2H,
PCH2P, 2J(HP) = 9.7), 2.68 (s, 3H, MeC@N), 1.22 (t,
3H, NHCH2CH3, 3J(HH) = 7.4 Hz). 31P–{1H} NMR
References
2
(CDCl3, d ppm, J Hz): 23.6 (d, 1P, PA, J(PP) = 75.1),
2
ꢀ26.7 (d, 1P, PB, J(PP) = 75.1).
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