Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives, Dimethyl Sulphoxide and Chloride: Syntheses, Molecular Structures, and ESCA Data

Article abstract of DOI:10.1002/zaac.200300260

The platinum(II) mixed ligand complexes [PtCl(L^1-6)-(dmso)] with six differently substituted thiourea derivatives HL, R₂NC(S) NHC(O)R′ (R = Et, R′ = p-O₂N-Ph: HL¹; R = Ph, R′ = p-O₂N-Ph: HL²; R = R′ = Ph: HL ³; R = Et, R′ = o-Cl-Ph: HL⁴; R₂N = EtOC(O)N(CH₂CH₂)₂N, R′ = Ph: HL ⁵) and Et₂NC(S)N= CNH-1-Naph (HL⁶), as well as the bis(benzoylthioureato-κO,κS)-platinum(II) complexes [Pt(L ^1,2)₂] have been synthesized and characterized by elemental analysis, IR, FAB(+)-MS, ¹H-NMR, ¹³C-NMR, as well as X-ray structure analysis ([PtCl(L¹)(dmso)] and [PtCl(L ^3,4)(dmso)]) and ESCA ([PtCl(L^1,2)(dmso)] and [Pt(L ^1,2)₂]). The mixed ligand complexes [PtCl(L)(dmso)] have a nearly square-planar coordination at the platinum atoms. After deprotonation, the thiourea derivatives coordinate bidentately via O and S, DMSO bonds monodentately to the Pt¹¹ atom via S atom in a cis arrangement with respect to the thiocarbonyl sulphur atom. The Pt-S-bonds to the DMSO are significant shorter than those to the thiocarbonyl-S atom. In comparison with the unsubstituted case, electron withdrawing substituents at the phenyl group of the benzoyl moiety of the thioureate (p-NO₂, o-Cl) cause a significant elongation of the Pt-S(dmso)-bond trans arranged to the benzoyl-O-Pt-bond. The ESCA data confirm the found coordination and bonding conditions. The Pt 4f_7/2 electron binding energies of the complexes [PtCl(L^1,2)(dmso)] are higher than those of the bis(benzoylthioureato)-complexes [Pt(L^1,2)₂]. This may indicate a withdrawal of electron density from platinum(II) caused by the DMSO ligands.

Full text of DOI:10.1002/zaac.200300260

Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives, Dimethyl
Sulphoxide and Chloride: Syntheses, Molecular Structures, and ESCA Data
a
a*
b
b
b
´
Wilfredo Hernandez , Evgenia Spodine , Rainer Richter , Karl-Heinz Hallmeier , Uwe Schröder , and
Lothar Beyerb*
a
´
Santiago de Chile / Chile, Universidad, Facultad de Ciencias Quımicas y Farmaceuticas
b Leipzig, Universität, Fakultät für Chemie und Mineralogie
Received July 25th, 2003.
Abstract. The platinum(II) mixed ligand complexes [PtCl(L1-6)-
(dmso)] with six differently substituted thiourea derivatives HL,
R2NC(S)NHC(O)RЈ (R ϭ Et, RЈ ϭ p-O2N-Ph: HL1; R ϭ Ph, RЈ ϭ
p-O2N-Ph: HL2; R ϭ RЈ ϭ Ph: HL3; R ϭ Et, RЈ ϭ o-Cl-Ph: HL4;
R2N ϭ EtOC(O)N(CH2CH2)2N, RЈ ϭ Ph: HL5) and Et2NC(S)Nϭ
CNH-1-Naph (HL6), as well as the bis(benzoylthioureato-κO,κS)-
platinum(II) complexes [Pt(L1,2)2] have been synthesized and
characterized by elemental analysis, IR, FAB(ϩ)-MS, 1H-NMR,
13C-NMR, as well as X-ray structure analysis ([PtCl(L1)(dmso)]
and [PtCl(L3,4)(dmso)]) and ESCA ([PtCl(L1,2)(dmso)] and
[Pt(L1,2)2]). The mixed ligand complexes [PtCl(L)(dmso)] have a
nearly square-planar coordination at the platinum atoms. After de-
protonation, the thiourea derivatives coordinate bidentately via O
and S, DMSO bonds monodentately to the PtII atom via S atom
in a cis arrangement with respect to the thiocarbonyl sulphur atom.
The PtϪS-bonds to the DMSO are significant shorter than those
to the thiocarbonyl-S atom. In comparison with the unsubstituted
case, electron withdrawing substituents at the phenyl group of the
benzoyl moiety of the thioureate (p-NO2, o-Cl) cause a significant
elongation of the PtϪS(dmso)-bond trans arranged to the benzoyl-
OϪPt-bond. The ESCA data confirm the found coordination and
bonding conditions. The Pt 4f7/2 electron binding energies of the
complexes [PtCl(L1,2)(dmso)] are higher than those of the bis(ben-
zoylthioureato)-complexes [Pt(L1,2)2]. This may indicate a with-
drawal of electron density from platinum(II) caused by the
DMSO ligands.
Keywords: Platinum; Thiourea; DMSO; Crystal structure; ESCA
Platin(II)-Gemischtliganden-Komplexe mit Thioharnstoffderivaten, Dimethylsulfoxid
und Chlorid: Synthesen, Molekülstrukturen und ESCA-Daten
Inhaltsübersicht. Es wurden die Platin(II)-Gemischtliganden-Kom-
plexe [PtCl(L1-6)(dmso)] mit sechs unterschiedlich substituierten
Thioharnstoffderivaten HL, R2NC(S)NHC(O)RЈ (R ϭ Et, RЈ ϭ
p-O2N-Ph: HL1; R ϭ Ph, RЈ ϭ p-O2N-Ph: HL2; R ϭ RЈ ϭ Ph:
HL3; R ϭ Et, RЈ ϭ o-Cl-Ph: HL4; R2N ϭ EtOC(O)N(CH2CH2)2N,
RЈ ϭ Ph: HL5) und Et2NC(S)NϭCNH-1-Naph (HL6), sowie die
Bis(benzoylthioureato-κO,κS)-platin(II)-Komplexe [Pt(L1,2)2] dar-
monodentat über S in cis-Anordnung zum Thiocarbonyl-Schwefel-
atom an das PtII-Atom. Die PtϪS-Bindungen zum DMSO sind
dabei deutlich kürzer als jene zum Thiocarbonyl-S-Atom. Elektro-
nenziehende Substituenten an der Phenylgruppe des Benzoylteils
des Thioureats (p-NO2, o-Cl) führen zu einer signifikanten Ver-
längerung der zur Benzoyl-OϪPt-Bindung trans-ständigen
PtϪS(dmso)-Bindung im Vergleich zum unsubstituierten Fall. Die
ESCA-Daten bestätigen die gefundenen Koordinations- und Bin-
dungsverhältnisse. Die im Vergleich zu den Bis(benzoylthioureato)-
Komplexen [Pt(L1,2)2] erhöhten Pt 4f7/2-Elektronenbindungsener-
gien der Komplexe [PtCl(L1,2)(dmso)] deuten auf einen möglichen
Abzug von Elektronendichte vom Platin(II)-Atom durch die
DMSO-Liganden hin.
1
gestellt und mittels Elementaranalyse, IR, FAB(ϩ)-MS, H-NMR,
13C-NMR, sowie Röntgenkristallstrukturanalyse ([PtCl(L1)(dmso)]
und [PtCl(L3,4)(dmso)]) und ESCA ([PtCl(L1,2)(dmso)] und
[Pt(L1,2)2]) charakterisiert. Die Gemischtliganden-Komplexe
[PtCl(L)(dmso)] weisen eine nahezu quadratisch-planare Koordina-
tion an den Platinatomen auf. Die Thioharnstoffderivate koordinie-
ren nach Deprotonierung bidentat über O und S, DMSO bindet
Introduction
In this context platinum complexes with ligands of gradual
leaving tendencies are of special interest because the thera-
peutical efficacy is determined by substitution intermediates
produced in the organism. Recently, we showed the can-
cerostatic efficacy of related cis-bis(acylthioureato)plati-
num(II) chelates [2]. This fact motivated us to synthesize
and characterize some new cis-platinum(II) complexes with
the title ligands. Furthermore, the ligands we used per se
have bioactivity, thus there is a hope of synergistic effects.
Sacht and co-workers recently described platinum(II)
complexes Ϫ also related to the acylthioureato complexes
studied long-standingly in our group Ϫ and investigated
Cis-platinum complexes are very important neoplasic ag-
ents [1]. The aim of the research is to find out compounds
with a spectrum of action different from that of cisplatin.
* Prof. Dr. L. Beyer
Inst. f. Anorgan. Chemie der Universität
Johannisallee 29
D-04103 Leipzig
Fax: ϩϩ49(0)341-9736161
E-mail: beyinorg@chemie.uni-leipzig.de
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´
W. Hernandez, E. Spodine, R. Richter, K.-H. Hallmeier, U. Schröder, L. Beyer
them for interactions with DNA [3Ϫ6]. Furthermore, metal
thesized from K2[PtCl4] and HL1,2 in dioxane/water in the
molar metal/ligand ratio of 1 : 2. Sodium acetate as proton
acceptor was added in all cases.
complexes with dimethyl sulphoxide (DMSO) as ligands are
interesting for us because such complexes in our group have
been the object of earlier preparative and kinetic investi-
gations about the building and the substitution reactions in
solution, namely in the case of classical Werner type com-
plexes of cobalt(III) [7, 8]. We herein present the syntheses,
as well as the characterization of the ligands and plati-
num(II) complexes by elemental analysis, IR, FAB(ϩ)-
mass, 1H-NMR and 13C-NMR spectroscopy. Especially
comparative ESCA data are used in order to reveal the
bonding and structural situation. The X-ray structures of
the complexes 1, 3 and 4 are also reported. The synthesized
complexes will be tested for their cancerostatic efficacy in a
further study.
The platinum complexes were isolated in yields of 40-
60 % as yellow or orange solids. They were washed with
water and ethanol and dried in vacuo. Recrystallization
from dichloromethane gave crystals suitable for X-ray dif-
fraction for 1, 3 and 4. The elemental analysis, FAB(ϩ)-
1
mass-, H-NMR-, and IR- spectra data proving the struc-
tures presented here are given in experimental part.
Molecular structures
The molecular structures of the complexes cis-
[PtCl(L)(dmso)] 1, 3 and 4 with the atom numbering
scheme for all non-hydrogen atoms are shown in the figures
1, 2 and 3, respectively. Selected bond lengths and angles
are given in Table 1.
Results and Discussion
All three complexes have a nearly square-planar coordi-
nation at the platinum atoms indicated by the angles be-
tween the planes through Pt1S1O1 and Pt1S2Cl1: 3.9(1)
and 4.0(1)° for 1 and 1.9(1)o for 3 and 4. The platinum(II)
ion is coordinated to a chelate ligand and two monodentate
groups, namely DMSO and chloride. The structural deter-
minations of these complexes confirm that the chelate li-
gand is bonded bidentately to platinum atom through the
sulphur and oxygen donor atoms while the sulphoxide li-
gand is coordinated to platinum atom via the sulphur atom
Synthesis
Scheme 1 shows the pathways for the syntheses of the plati-
num(II) complexes 1-8. Compounds 1-5 were obtained by
reaction of cis-dichloro-bis(dimethylsulphoxide)-plati-
num(II) by reaction with the bidentate ligands HL1-5 in a
DMSO-acetonitrile-mixture, compound 6 by treatment
with N-(diethylaminothiocarbonyl)-NЈ-1-naphthylbenzami-
dine (HL6) in a DMSO-ethanol-water-mixture. The bis-
thioureato-κO,κS platinum(II) complexes 7 and 8 were syn-
Scheme 1
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Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives, Dimethyl Sulphoxide and Chloride
Figure 1 Molecular structure of {chloro-[N-(p-nitrobenzoyl)-NЈ,NЈ-diethyl-thioureato-κO,κS]-dimethylsulphoxide-κS}-platinum(II) (1)
Figure
2 Molecular structure of [chloro-(N-benzoyl-NЈ,NЈ-di-
Figure 3 Molecular structure of {chloro-[N-(o-chlorbenzoyl)-NЈ,NЈ-
diethyl-thioureato-κO,κS]-dimethylsulphoxide-κS}-platinum(II) (4)
phenyl-thioureato-κO,κS)-dimethylsulphoxide-κS]-platinum(II) (3)
˚
in a cis arrangement with respect to the sulphur atom of
the acylthiourea as reported in related platinum(II) com-
plexes, too [4, 5]. The bond lengths involving platinum fall
within the expected ranges. The Pt1ϪS1 bonds (2.255-
1.736 (average), 1.736(5) and 1.725(6) A) and carbonyl
˚
bonds (O1ϪC2: 1.278 (average), 1.281(6) and 1.270(7) A)
for 1, 3 and 4, respectively, are longer than in the ligands
(S1ϪC1: 1.664(2) and 1.658(2) A , O1ϪC2: 1.209(3) and
1.218(2) A). Furthermore, the two contiguous CϪN bonds
in the chelate rings (N1ϪC1: 1.377 (average), 1.329(6) and
1.356(7) A, N1ϪC2: 1.303 (average), 1.308(6) and
1.330(7) A), for 1, 3 and 4, respectively) are shorter com-
pared with the corresponding bonds of the ligands
˚
˚
˚
2.259 A) are significantly longer than the Pt1ϪS2 bonds to
˚
the DMSO ligand (2.188-2.199 A). The Pt1ϪO1 bonds
˚
˚
˚
˚
(2.010-2.011 A) and the Pt1ϪCl1 bonds (2.328-2.332 A)
also agree well with the structures of other complexes of
this type [4, 5].
˚
By comparison with the structures of the free ligands
(N1ϪC1: 1.391(3) and 1.428(2) A, N1ϪC2: 1.389(3) and
1.360(2) A). In all three structures the N1ϪC1 bonds in the
HL2 [2] and HL4 [9], the thiocarbonyl bonds (S1ϪC1:
˚
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˚
As can be seen in Table 1, the PtϪS2(sulphoxide) bonds
for the complexes 1 and 4 (2.195 (average) and 2.199(1) A,
Table 1 Selected bond lengths/A and angles/° for 1, 3 and 4.
˚
1
3
4
respectively) with substituted phenyl rings are slightly
molecule a
molecule b
˚
longer than in the complex 3 (2.188(1) A) and in cis-
Bond lengths
Pt1ϪS1
Pt1ϪO1
S1ϪC1
O1ϪC2
N1ϪC1
N1ϪC2
N2ϪC1
Pt1ϪS2
S2ϪO2
[PtCl(L)(dmso)] (HL ϭ N,N-diethyl-NЈ-benzoylthiourea)
(2.189(1) A [5]) with unsubstituted phenyl rings. This fact
2.262(3)
2.015(8)
1.734(12)
1.274(15)
1.376(15)
1.276(16)
1.323(17)
2.200(3)
1.467(9)
2.330(4)
2.252(3)
2.005(7)
1.738(12)
1.282(14)
1.378(14)
1.330(16)
1.258(16)
2.189(3)
1.449(10)
2.334(4)
2.259(1)
2.011(3)
1.736(5)
1.281(6)
1.329(6)
1.308(6)
1.361(6)
2.188(1)
1.456(4)
2.328(1)
2.255(2)
2.010(4)
1.725(6)
1.270(7)
1.356(7)
1.330(7)
1.367(9)
2.199(1)
1.467(4)
2.328(1)
˚
indicates that the presence of the substituent groups (p-NO2
and o-Cl) in the benzoyl fragment seems to elongate the
PtϪS2(sulphoxide) bonds.
The phenyl rings of the acylthiourea ligands form differ-
ent angles with the chelate rings: 7.3(7) and 8.6(10)° for
1 (p-nitrophenyl), 6.0(6)° for 3 (phenyl) and 80.5(5)° for 4
(o-chlorophenyl).
Pt1ϪCl1
Bond angles
S1ϪPt1ϪO1
S1ϪPt1ϪS2
S2ϪPt1ϪCl1
O1ϪPt1ϪCl1
S1ϪPt1ϪCl1
S2ϪPtϪO1
Pt1ϪS1ϪC1
Pt1ϪO1ϪC2
C1ϪN1ϪC2
S1ϪC1ϪN1
O1ϪC2ϪN1
No significant intermolecular interactions are observed
in 1, 3 and 4.
93.6(3)
90.1(1)
91.0(1)
93.5(3)
89.7(1)
91.4(1)
94.27(10)
89.69(5)
90.48(5)
85.56(10)
178.05(5)
176.04(10)
106.9(2)
130.3(3)
127.1(4)
130.9(4)
130.1(5)
93.98(12)
89.98(5)
90.75(5)
85.31(12)
179.17(5)
175.63(13)
108.3(2)
130.0(3)
125.6(5)
130.0(4)
131.1(5)
85.4(3)
85.6(3)
176.7(1)
175.6(3)
108.4(5)
129.6(8)
126.8(11)
128.1(11)
132.4(11)
177.4(1)
175.5(3)
109.3(4)
130.5(8)
125.7(10)
127.8(10)
130.5(11)
ESCA spectra
Table 2 shows the electron binding energies (eV) of the com-
plexes 1 and 2 (with DMSO as one ligand), the ligands
HL1, HL2 and the cis-bis(benzoyl-thioureato)-platinum(II)
complexes 7 and 8. The values of HL1, HL2, 7 and 8 are
presented here for comparative purposes. The electron bind-
ing energies were acquired from photoelectron spectra of
core levels. Information obtained concerns binding situ-
ation and structure.
The electron binding energies confirm the proposed coor-
dination patterns for the DMSO complexes 1 and 2 and
also for the bis complexes 7 and 8. This is proved by the N
1s, S 2p3/2 and Pt 4f7/2 signals in the spectra of compounds
under investigation.
thiourea fragment are longer than the N1ϪC2 bonds in the
acyl fragment of the chelate ring, in general agreement with
other platinum(II) complexes of the investigated type [4, 5]
and also with the structures of several bis(N-acylthioureato)
complexes [2, 4, 9Ϫ15]. These results confirm the decrease
of the bond orders of the thiocarbonyl and carbonyl groups
upon complexation and indicate the presence of an extens-
ive delocalization of π electron density in the chelate ring
of the platinum(II) sulphoxide complexes. This is also con-
N 1s electron binding energies. At the complex formation
occurs deprotonation of one nitrogen atom in the ligands
1
firmed by IR, FAB(ϩ)-mass and H-NMR spectroscopy.
Table 2 Binding energies/eV, (half-widths/eV / concentrations (atom percent)) of the inner shell levels of the photoelectron spectra.
C1s
N1s
O1s
S2p3/2
Pt 4f7/2
HL1
285.0 (1.8/39.33)
285.8 (1.8/15.58)
287.8 (1.8/7.18)
400.0 (1.7/10.45)
405.9 (1.7/5.51)
531.5 (1.6/6.37)
533.0 (1.6/9.89)
535.5 (1.6/0.94)
161.7 (1.5/4.45)
167.7 (1.2/0.30)*
7
285.0 (1.8/41.27)
285.7 (1.8/14.11)
287.3 (1.8/8.57)
289.5 (1.8/0.90)
398.4 (1.7/4.45)
399.8 (1.7/3.84)
406.0 (1.7/4.66)
532.2 (1.7/10.00)
533.3 (1.7/6.45)
535.3 (1.7/0.53)
162.8 (1.5/3.37)
72.8 (1.6/1.85)
73.4 (1.8/3.90)
1a)
HL2
8
285.0 (1.8/31.98)
285.7 (1.8/18.47)
287.6 (1.8/6.00)
398.8 (1.8/3.90)
400.1 (1.8/4.63)
406.1 (1.8/3.16)
532.0 (1.8/9.95)
533.2 (1.8/6.78)
163.4 (1.8/4.83)
167.1 (1.8/3.20)
284.6 (1.7/46.58)
285.5 (1.7/20.59)
287.9 (1.7/3.79)
400.2 (1.7/7.93)
405.9 (1.7/4.40)
531.6 (1.7/4.73)
532.9 (1.7/8.07)
535.6 (1.7/0.57)
161.9 (1.6/3.16)
168.4 (1.5/0.18)*
284.6 (1.7/58.29)
285.5 (1.7/7.58)
287.2 (1.7/4.99)
398.3 (1.7/4.15)
400.0 (1.7/2.89)
405.8 (1.7/3.98)
532.2 (1.8/9.71)
533.3 (1.8/4.02)
535.1 (1.8/0.42)
162.7 (1.5/2.63)
72.6 (1.5/1.34)
73.2 (1.7/1.70)
2b)
284.6 (1.8/42.95)
285.4 (1.8/20.12)
287.1 (1.8/3.32)
288.7 (1.8/2.41)
398.6 (1.8/1.99)
400.2 (1.8/1.80)
406.0 (2.0/2.03)
532.1 (1.8/12.26)
533.4 (1.8/6.28)
163.1 (1.9/1.90)
166.9 (1.4/1.50)
* slight contamination on the surface. 1a): Cl2p3/2 198.4 eV (1.7/3.2); 2b): Cl2p3/2 198.3 eV (1.5/1.74).
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Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives, Dimethyl Sulphoxide and Chloride
HL1 and HL2 containing the thiourea unit. This is indicated
by a shift of the N 1s signal of the complex in comparison
with the thiourea ligand. The results indicate a decrease of
the N 1s binding energy comparing the signals of the ligand
HL1 and its platinum (II) complexes 7 and 1 from 400.0 eV
(HL1) to 398.4 eV (7) and 398.8 eV (1). The second series
of comparison with the ligand HL2 and its platinum com-
plexes 8 and 2 leads to analogous changes of the N 1s sig-
nals from 400.2 eV (HL2) to 398.3 eV (8) and 398.6 eV (2).
The nitrogen atoms of the ϪNEt2 and ϪNPh2 groups in
the complexes 7 (399.8 eV) and 1 (400.1 eV) as well as 8
(400.0 eV) and 2 (400.2 eV) in comparison with the corre-
sponding ligands HL1 (400.0 eV) and HL2 (400.2 eV), as
expected, have nearly unchanged values. The N 1s signal
from the NO2 group likewise remains constant: HL1
(405.9 eV); 7 (406.0 eV); 1 (406.1 eV) and HL2 (405.9 eV);
8 (405.8 eV); 2 (406.0 eV).
Pt 4f7/2electron binding energies. In view of the compara-
tively increased donor power of the sulphur atom in the
DMSO complexes, surprisingly, the Pt 4f7/2 signals of 1
(73.4 eV) and 2 (73.2 eV) in comparison to the bis-com-
plexes 7 (72.8 eV) and 8 (72.6 eV) are increased in each case
by 0.6 eV, i. e. the electrons are tighter bound at the plati-
num atom. Obviously, this is consistent with the assumption
that DMSO is able to take up electron density from the
platinum(II) which on its part compensates this deficiency
by the thiourea sulphur atom.
The Cl 2p3/2 signals with the binding energies (198.4 eV
for 1 and 198.3 eV for 2) prove the behaviour of the chlorine
atoms as chloro (chloride) ligands.
Also the intensities of the individual components and the
derived concentrations (atom-%) using sensitivity factors
are, after rounding, in accordance with the composition of
the samples (see Table 2).
S 2p3/2 binding energies. A dative bond of the thioureato
sulphur atom is indicated for the complexes 1 (163.4 eV)
and 7 (162.8 eV) as well as 2 (163.1 eV) and 8 (162.7 eV)
by the increase of the S 2p3/2 electron binding energy in
comparison with the non complexed ligands 161.7 eV
(HL1) and 161.9 eV (HL2). Thereby it is to be stated that
the S 2p3/2 binding energies of the respective metal coordi-
nated thioureato sulphur atom in the DMSO complexes are
significant higher than in the respective bis-complexes (1
compared with 7 by 0.6 eV; 2 compared with 8 by 0.4 eV).
This means an increased electron donor influence of the
respective sulphur atom related to the platinum central
atom in the DMSO coordinated complexes. The electron
binding energy of the metal coordinated DMSO sulphur
atom is considerable higher than that in the thioureato li-
gands (1: 167.1 eV, 2: 166.9 eV).
Experimental
General
Potassium tetrachloroplatinate(II) was purchased from Merck,
Darmstadt. The complex cis-[PtCl2(dmso)2] was prepared accord-
ing to a reported method [16]. All other chemicals and solvents
(Aldrich) were analytical grade and used as supplied, except ace-
tone which was distilled before use. Elemental analyses were deter-
mined on a Fisons-Carlo Erba 1108 elemental microanalyser. Melt-
ing points were determined on a Boetius melting-point apparatus.
IR spectra were recorded as KBr discs in the range 4000-400 cmϪ1
on a Bruker FT-IR IFS 55 Equinox spectrophotometer. The 1H
and 13C NMR spectra were recorded on a Bruker advance DRX
300 spectrometer at 300 K using CDCl3 as solvent. FAB(ϩ) mass
spectra were obtained on a ZAB-HSQ (V.G. Analytical Ltd.) spec-
trometer (matrix: 3-NBA).
Table 3 Crystal data and details of structure determination for 1, 3 and 4.
1
3
4
Empirical formula
Mr /g molϪ1
C14H20O4N3S2ClPt
588.99
C22H21O2N2S2ClPt
640.07
C14H20O2N2S2Cl2Pt
578.43
yellow prisms
monoclinic
P21/c (No. 14)
9.963(2)
Crystal habit, color
Crystal system
Space group
yellow prisms
triclinic
yellow prisms
trigonal
¯
¯
P1 (No. 2)
R3 (No. 148)
˚
a / A
7.143(1)
10.193(2)
28.237(6)
88.024(4)
83.717(4)
74.871(4)
1972.6(7)
4; 1136
1.983
34.949(7)
34.949(7)
9.935(3)
˚
b / A
10.190(2)
18.439(4)
˚
c / A
α / °
β / °
γ / °
99.331(4)
3
˚
V / A
10509(4)
18; 5580
1.820
1847.2(8)
4; 1112
2.080
Z; F(000)
ρ(calc.) /g cmϪ3
Crystal size /mm
Absorption coeff. µ/mmϪ1
2θ range /°
Measured reflections
Unique reflections
Observed reflections(I> 2σ (I))
Refined parameters
wR2 (unique refl.)
R1 (observed refl.)
Goodness-of-fit on F2
0.06 x 0.25 x 0.25
7.484
4.1Ϫ58.6
12872
9145
7439
459
0.1655
0.0675
1.199
0.04 x 0.08 x 0.26
6.322
4.0Ϫ58.3
22383
5875
4132
273
0.0647
0.0395
1.009
0.13 x 0.50 x 0.55
8.120
4.1Ϫ58.5
11277
4548
4345
241
0.1226
0.0432
1.109
Ϫ3
˚
Largest difference peak and hole/e A
6.15/Ϫ2.28
2.51/Ϫ0.61
3.33/Ϫ3.90
Z. Anorg. Allg. Chem. 2003, 629, 2559Ϫ2565
zaac.wiley-vch.de
 2003 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2563

´
W. Hernandez, E. Spodine, R. Richter, K.-H. Hallmeier, U. Schröder, L. Beyer
Crystal structure determination
General procedure for the synthesis of the
platinum(II) complexes 1-6:
The data for the crystal structure determinations were collected
on a Siemens CCD Smart Diffractometer (MoKα radiation, λ ϭ
0.71073 A, graphite monochromator, T ϭ 218(2) K).
0.25 mmol of the ligand (HL1-6) dissolved in 10 mL DMSO/aceto-
nitrile (1:1 v/v) were added drop by drop to a solution of 0.25 mmol
cis-[PtCl2(dmso)2] in 50 mL, for 1-5, DMSO/acetonitrile (1:1 v/v)
and, for 6, DMSO/ethanol/water (1:1:1 v/v/v). 2mL of a aqueous
solution of 0.25 mmol sodium acetate was added. The reaction
mixture was stirred at room temperature for 48 h followed by the
reduction of the volume to the half. After addition of 70 mL water,
the complexes 1-6 precipitated as yellow solids which were washed
with water and ethanol and dried in vacuo.
˚
The intensities were corrected for Lorentz and polarization effects
and for absorption using SADABS. The structures were solved by
direct methods and refined by least-squares procedures [17]. The
positions of all hydrogen atoms were calculated geometrically and
taken into account with isotropic temperature factors 1.2 times
higher than Ueq of the parent C atoms. In spite of the fact that the
crystals of 1 were not of good quality we included the results in
this paper because the structure is well defined and is of accept-
able accuracy.
{Chloro-[N-(p-nitrobenzoyl)-NЈ,NЈ-diethyl-
thioureato-κO,κS]-dimethylsulphoxide-κS}-
platinum(II), (1)
Some details of crystal data and structure determination are given
in Table 3.
Further details of the crystal structure determinations are available
on request from the Cambridge Crystallographic Data Center, 12
Union Road, Cambridge CB2 1EZ, UK, on quoting the depositing
numbers CCDC-218079 (1), CCDC-218080 (3) and CCDC-218081
(4), the names of the authors, and the journal citation.
Yellow prisms. Yield: 0.089 g (61 %). Mp.: 182-184 °C.
C14H20O4N3S2ClPt (588.99 g/mol);calc.: C 28.5; H 3.4; N 7.1; S
10.9 %; found: C 28.0; H 3.4; N 7.2; S 11.3 %.
IR (KBr, cmϪ1): ν(CϭO) 1638 (m); ν(CϭS) 1251 (m); ν(SϭO) 1157 (m). MS
(FABϩ) m/z 589 (Mϩ, 100 %). 1H-NMR (300 MHz, CDCl3): δ 1.32 (t, 3H,
CH3); 1.38 (t, 3H, CH3); 3.62 (s, 6H, SCH3); 3.86 (m, 4H, CH2); 8.23 (d,
2H, o-Ph); 8.34 (d, 2H, m-Ph). 13C-NMR (75.45 MHz, CDCl3): δ 12.2 13.1
(CH3); 46.5 46.6 (CH2); 47.7 (SCH3); 123.3 130.7 141.5 149.9 (Ph); 166.8
(CO); 167.6 (CS).
ESCA spectra
The ESCA spectra were recorded using the photoelectron spec-
trometer VG (Vacuum Generators) ESCALAB 220i XL by exci-
tation with Al Kα radiation (U ϭ 12 kV, I ϭ 20 mA). The vacuum
during the measurements was 3·10Ϫ8 Torr. The powder samples
were grinded onto double-sided adhesive carbon tape. To account
for charging the binding energies were related to the main compo-
nent of the carbon 1s peak (285.0 eV for sample series HL1/7/1
sp3 carbon], 284.6 eV for sample series HL2/8/2 sp2 carbon]). The
analyser pass energy was for the single spectra 10 eV. Curve fitting
was performed using the program “UNIFIT for WINDOWS” [18].
The single components were approximated with Gaussian-Lorentz-
ian fractions (Voigt curves).
{Chloro-[N-(p-nitrobenzoyl)-NЈ,NЈ-diphenyl-
thioureato-κO,κS]-dimethylsulphoxide-κS}-
platinum(II), (2)
Yellow prisms. Yield: 0.09 g (62 %). Mp.: 142-145 °C.
C22H20O4N3S2ClPt (684.58 g/mol); calc.: C 50.7; H 3.0; N 8.9; S
6.7 %; found: C 50.3; H 3.2; N 8.6; S 6.4 %.
IR (KBr, cmϪ1): ν(CϭO) 1640 (m); ν(CϭS) 1257 (m); ν(SϭO) 1163
(m). MS (FABϩ) m/z 685 ([M ϩ H]ϩ, 100 %). 1H-NMR (300 MHz,
CDCl3): δ 3.57 (s, 6H, SCH3); 7.46 (m, 10H, Ph); 7.90 (d, 2H, Ph);
8.06 (d, 2H, Ph). 13C-NMR (75.45 MHz, CDCl3): δ 46.6 (SCH3);
123.2 127.6 127.7 129.4 131.1 143.8 (Ph); 168.11 (CO); 173.5 (CS).
Synthesis and characterization of the ligands
[Chloro-(N-benzoyl-NЈ,NЈ-diphenyl-thioureato-
κO,κS)-dimethylsulphoxide-κS]-platinum(II), (3)
The ligands HL1-4 and HL6 were synthesized following literature
procedures: HL1 [19, 20], HL2, HL3 [2, 19], HL4 [9, 19], HL6 [21,
22].
Pale yellow prisms. Yield: 0.109 g (68 %). Mp. 238-240 °C(dec.).
C22H21O2N2S2ClPt (640.07 g/mol); calc.: C 41.3; H 3.3; N 4.4; S
10.0 %; found: C 40.9; H 3.4; N 4.5; S 10.1 %.
IR (KBr, cmϪ1): ν(CϭO) 1620 (m); ν(CϭS) 1255 (m); ν(SϭO) 1141 (m). MS
(FABϩ) m/z 640 (Mϩ, 100 %). 1H-NMR (300 MHz, CDCl3): δ 3.56 (s, 6H,
SCH3); 7.22-7.37 (m, 10H, Ph); 7.42 (d, 2H, Ph); 7.70 (d, 1H, Ph); 7.80 (d,
2H, Ph). 13C-NMR (75.45 MHz, CDCl3): δ 46.6 (SCH3); 128.1 129.6 130.4
132.6 134.0 134.8 (Ph); 164.1 (CO); 171.1 (CS).
N-(4-ethoxycarbonyl-piperazin-1-yl-thiocarbonyl)benzamide, HL5:
A solution of 10 mmol (1.5 mL) 4-ethoxycarbonyl-piperazine in
20 mL acetone was added drop by drop to a solution of 10 mmol
(1.35 mL) benzoylisothiocyanate in 20 mL acetone and kept re-
fluxed for two hours. Then the mixture was stirred for 24 hours at
room temperature, followed by filtration and evaporation. Thus a
greasy mass was obtained and digested with ether yielding a
colourless precipitation which was washed with ethanol, dried in
vacuo and recrystallized from dichloromethane. Yield: 2.19 g
(68 %). Melting point: 135-137 °C. C15H19O3N3S (321.4 g/mol)-
calc.: C 56.06; H 5.96; N 13.07; S 9.98 %; found: C 55.9; H 5.74;
N 13.1; S 9.89 %.
{Chloro-[N-(o-chlor-benzoyl)-NЈ,NЈ-diethyl-
thioureato-κO,κS]-dimethylsulphoxide-κS}-
platinum(II), (4)
IR (KBr, cmϪ1): ν(NH) 3284 (m); ν(COO) 1701 (vs); ν(CϭO) 1671 (vs);
ν(CϭS) 1225 (s). MS (FABϩ) m/z 322.1 (Mϩ, 100 %). 1H-NMR (300 MHz,
CDCl3): δ 1.28 (t, 3H, CH3); 3.20 (br, 4H, CH2pip); 3.67 (t, 4H, CH2pip); 4.19
(q, 2H, CH2); 7.50 (dd, 2H, m-Ph); 7.61 (t, 1H, p-Ph); 7.87 (d, 2H, o-Ph);
8.56 (s, 1H, NH). 13C-NMR (75.45 MHz, CDCl3): δ 14.8 (CH3); 40.7 43.5
62.0 (CH2); 127.1 (COO); 127.9 129.1 130.2 133.3 (Ph); 163.4 (CO); 179.9
(CS).
Yellow prisms. Yield: 0.087 g (60 %). Mp.: 157-159 °C.
C14H20O2N2S2Cl2Pt (578.43 g/mol); calc.: C 29.07; H 3.49; N 4.84;
S 11.09; Cl 12.26 %; found: C 30.02; H 3.26; N 4.71; S 10.69; Cl
11.98 %.
IR (KBr, cmϪ1): ν(CϭO) 1528 (w); ν(CϭS) 1245 (m); ν(SϭO) 1149 (s). MS
(FABϩ) m/z 579 ([M ϩ H]ϩ, 100 %). 1H-NMR (300 MHz, CDCl3): δ 1.32
2564
 2003 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
zaac.wiley-vch.de
Z. Anorg. Allg. Chem. 2003, 629, 2559Ϫ2565

Platinum(II) Mixed Ligand Complexes with Thiourea Derivatives, Dimethyl Sulphoxide and Chloride
(m, 6H, CH3); 3.61 (s, 6H, SCH3); 3.98 (m, 4H, CH2); 7.85 (d, 1H, o-Ph);
7.43 (t, 1H, p-Ph); 7.25 (m, 2H, m-Ph).
Yellow solid. Mp.: 283-285 °C; Yield: 0.19 g (80 %).
C40H28O6N6S2Pt (947.89 g/mol). calc.: C 50.68; H 2.96; N 8.87; S
6.76 %; found: C 50.3; H 3.05; N 8.54; S 6.38 %.
IR (KBr, cmϪ1): ν(CϭO) 1640 (m), ν(CϭS) 1220 (w). MS (FABϩ; matrix:
3-NBA) m/z 948 (Mϩ, 100 %). 1H-NMR (300 MHz, CDCl3) : δ 7.41 (m,
20H, Ph); 7.93 (d, 4H, Ph); 8.13 (d, 4H, Ph).
{Chloro-[N-(4-ethoxycarbonyl-piperazin-1-yl-
thiocarbonyl)benzamidato-κO,κS]-
dimethylsulphoxide-κS}-platinum(II), (5)
Yellow solid. Yield: 100 mg (60.4 %). Mp.: 180-185 °C.
C17H24O4N3S2ClPt (629.05 g/mol), calc.: C 32.46; H 3.85; N 6.68; S
10.19; Cl 5.64 %; found: C 32.2; H 3.91; N 6.88; S 10.39; Cl 5.75 %.
References
IR (KBr, cmϪ1): ν(COO) 1698 (s); ν(CϭO) 1645 (w,sh); ν(CϭS) 1234 (m);
ν(SϭO) 1128 (s); ν(Pt-Cl) 325 (m), 311 (m). MS (FABϩ) m/z 629 (Mϩ,
100 %). 1H-NMR (300 MHz, CDCl3): δ 1.24 (t, 3H, CH3); 3.58 (br, 8H,
CH2pip); 3.63 (br, 6H, SCH3); 4.09 (q, 2H, CH2); 7.50 (t, 2H, m-Ph); 7.68 (t,
1H, p-Ph); 8.12 (d, 2H, o-Ph). 13C-NMR (75.45 MHz, CDCl3): δ 14.5 (CH3);
40.8 60.9 (CH2); 128.4 129.4 132.6 134.6 (Ph).
[1] Z. Guo, P. J. Sadler, Angew. Chem. 1999, 111, 1610; Angew.
Chem. Int. Ed. 1999, 38, 1512.
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[2] W. Hernandez, E. Spodine, J. Mun˜oz, L. Beyer, U. Schröder,
J. Ferreira, M. Pavani, Bioinorg. Chem. Appl. 2003, accepted
for publication.
[3] C. Sacht, M. S. Datt, Polyhedron 2000, 19, 1347.
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Trans. 2000, 4579.
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{Chloro-[N-diethylaminothiocarbonyl)-NЈ-1-
naphthylbenzamidinato-κN,κS]-dimethylsulphoxide-
κS}-platinum(II), (6)
Yellow prisms. Yield: 0.078 g (46 %). Mp.: 175-178 °C;
C24H28ON3S2ClPt (669.16 g/mol); calc.: C 43.08; H 4.22; N 6.28; S
9.58; Cl 5.29 %; found: C 42.02; H 3.98; N 6.51; S 10.39; Cl 5.58 %.
IR (KBr, cmϪ1): ν(CϭO) 1625 (m); ν(CϭS) 1259 (m); ν(SϭO) 1139 (m). MS
(FABϩ) m/z 669 (Mϩ, 100 %); 633.2 (Mϩ ϪCl, 64 %). 1H-NMR (300 MHz,
CDCl3): δ 1.37 (m, 6H, CH3); 3.61 (s, 6H, SCH3); 3.73 (m, 2H, CH2); 4.01
(m, 2H, CH2); 7.14-7.55 (m, 6H, Arom); 7.75- 8.76 (m, 6H, Arom).
[9] R. A. Bailey, K. L. Rothaupt and R. Kullnig, Inorg. Chim.
Acta 1988, 147, 233.
[10] G. Fitzl, L. Beyer, J. Sieler, R. Richter, J. Kaiser, E. Hoyer, Z.
Anorg. Allg. Chem. 1977, 433, 237.
[11] R. Richter, L. Beyer, J. Kaiser, Z. Anorg. Allg. Chem. 1980,
461, 67.
[12] P. Knuuttila, H. Knuuttila, H. Hennig, L. Beyer, Acta Chem.
Scand. 1982, A36, 541.
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ersen, Z. Anorg. Allg. Chem. 1990, 580, 167.
[14] M. Reinel, R. Richter, R. Kirmse, Z. Anorg. Allg. Chem. 2002,
628, 41.
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[17] G.M. Sheldrick, SHELX-97, A Program System for the Solu-
tion and Refinement of X-ray Crystal Structures, Univ.
Göttingen, Germany 1997.
Bis[N-(para-nitrobenzoyl)-NЈ,NЈ-(diethylamino)-
thioureatoϪκO, κS]-platinum(II), (7)
To a solution of HL1 (0.141 g, 0.50 mmol) in dioxane (40 mL) was
added dropwise a solution of K2[PtCl4] (0.1038 g, 0.25 mmol) in
water (20 mL), followed by sodium acetate (0.041 g, 0.5 mmol) in
water (2 mL), and stirred for 2 h at 60 °C. Then the mixture was
stirred for 24 h at room temperature. The yellow precipitate was
collected by filtration, washed several times with small portions of
water, cold ethanol and dried in vacuo. Recrystallization of the
yellow solid was carried out from hot acetone.
Orange prisms. Mp.: 252-254 °C; Yield: 0.113 g (60 %).
C24H28O6N6S2Pt (755.08 g/mol). calc.: C 38.1; H 3.7; N 11.0; S
8.5 %; found: C 38.6; H 4.0; N 10.9; S 8.1 %.
IR (KBr, cmϪ1): ν(CϭO) 1640 (m), ν(CϭS) 1220 (w). MS (FABϩ) m/z 756
([M ϩ H]ϩ, 100 %). 1H-NMR (300 MHz, CDCl3): δ 1.34 (m, 12H, CH3);
3.82 (m, 8H, CH2); 8.29 (d, 4H, o-Ph); 8.38 (d, 4H, m-Ph). 13C-NMR
(75.45 MHz, CDCl3): δ 12.7 (CH3); 46.9 (CH2); 123.4 130.06 143.4 145.5
(Ph); 166.0 (CO); 167.3 (CS).
´
[18] R. Hesse, T. Chasse, R. Szargan, Fresenius Z. Anal. Chem.
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[21] L. Beyer, J. Hartung, R. Widera, Tetrahedron 1984, 40, 405.
[22] U. Schröder, R. Richter, L. Beyer, J. Angulo-Cornejo, M.
Lino-Pacheco, A. Guillen, Z. Anorg. Allg. Chem. 2003, 629,
1051.
Bis[N-(para-nitrobenzoyl)-NЈ,NЈ-diphenyl-thioureato-
κO, κS]-platinum(II), (8)
A similar procedure to 7 was carried out using HL2 (0.189 g,
0.50 mmol) and K2[PtCl4] (0.1038 g, 0.25 mmol) and stirring at
room temperature for 2 days.
Z. Anorg. Allg. Chem. 2003, 629, 2559Ϫ2565
zaac.wiley-vch.de
 2003 WILEY-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim
2565