Tin(IV) complexes with thiosemicarbazide and 4-methyl-3-thiosemicarbazide derivatives

Article abstract of DOI:10.1002/zaac.200700299

Five new complexes were isolated from a CH₂Cl₂ solution of SnCl₄ and the ligands benzil bis(thiosemicarbazone) L¹H₆, benzil bis(4-methyl-3-thiosemicarbazone) L ¹Me₂H₄, 5-methoxy5,6-diphenyl-4,5-dihydro-2H- [l,2,4]-triazine-3-thione, L²H₂OMe and 5-methoxy-4-methyl-5,6-diphenyl-4,5-dihydro-2H-[l,2,4]-triazine-3-thione, L ²MeHOMe. The characteristics of the complexesdepend on the ligand. Compounds were characterized by elemental analysis, mass spectrometry, IR, ¹³C and ¹¹⁹Sn CP/MAS NMR spectroscopy.

Full text of DOI:10.1002/zaac.200700299

DOI: 10.1002/zaac.200700299
Tin(IV) Complexes with Thiosemicarbazide and 4-Methyl-3-thiosemicarbazide
Derivatives
a
a
a
a,
b
´
´
David G. Calatayud , Elena Lopez-Torres , M Antonia Mendiola * and Jesus R. Procopio
a
b
´
´
´
´
´
Madrid/Spain, Departamento de Quımica Inorganica, Departamento de Quımica Analıtica y Analisis Instrumental, Universidad
´
Autonoma de Madrid
Received April 29th, 2007.
th
˜
Dedicated to Professor Alfonso Castineiras on the Occasion of his 65 Birthday
Abstract. Five new complexes were isolated from a CH2Cl2 solution
of SnCl4 and the ligands benzil bis(thiosemicarbazone) L1H6,
benzil bis(4-methyl-3-thiosemicarbazone) L1Me2H4, 5-methoxy-
5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-triazine-3-thione, L2H2OMe
and 5-methoxy-4-methyl-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-tri-
azine-3-thione, L2MeHOMe. The characteristics of the complexes
depend on the ligand. Compounds were characterized by elemental
analysis, mass spectrometry, IR, 13C and 119Sn CP/MAS NMR
spectroscopy.
Keywords: Thiosemicarbazone; Tin; Triazine complexes
Introduction
atom in an octahedral arrangement completed by halogen
ligands [6, 7]. In addition, the generally poor solubility of
group 14 metal complexes of anionic sulphur ligands makes
it difficult to structurally characterize these systems and
only few complexes have been studied by X-ray diffraction.
The most common coordination numbers for tin(IV) are
five or six. In fact, there are more than 3000 compounds
with this coordination while only 39 are eight-coordinate.
To date only three tin complexes with a N4S4 environment
have been reported, [Sn(2-SC5H4N-3-SiMe3)4] [8], [Sn(3-
CF3-pyS)4] [9], both with bidentate pyridine-thione ligands
and [Sn(ATSM)2], with two tetradentate ligands, which has
been recently published [10]. Due to the electronic delocalis-
ation, which is enhanced upon deprotonation, TSC ligands
are very versatile. This fact, together with the presence of
different types of donor atoms, allows several coordination
modes. So that, depending on the metal coordination pref-
erences, a particular ligand can show different coordination
behaviour. In particular, we have established in previous
works that benzil bis(thiosemicarbazone), L1H6 acts, at
least, as a N2S2 chelate, but depending on the metal prefer-
ences and/or the working conditions, the complexes show
different grade of deprotonation in the ligand as well as a
variety of structures. In fact, we have characterized com-
plexes of this ligand acting as a neutral molecule with cad-
mium and mercury nitrate [11], as a monoanion in copper
and zinc complexes [12] or as a dianionic ligand with differ-
ent metals [11, 13]. L1H6 can act as tetradentate chelate
giving mononuclear complexes [11Ϫ13], as chelate and
bridge through a sulfur atom yielding a dinuclear structure
and even as chelate and bridge via a nitrogen atom provided
by one terminal amine in a coordination polymer [13]. The
During the last few decades there has been a growing inter-
est in the pharmacological properties of thiosemicarba-
zones (TSCs) and their complexes, due to their ability to
function as antiviral, antibacterial, antifungal and an-
ticancer agents [1Ϫ4]. This activity is usually increased by
complexation, therefore understanding of the properties of
both ligand and metal can lead to the synthesis of highly
active compounds. In this respect, tin compounds have
interesting medical applications and understanding of the
mechanism of their activity requires detailed knowledge of
their structures and reactivities. In addition, the coordi-
nation chemistry of tin in solution and in the solid state is
an attractive target for structural studies by means of spec-
troscopic and diffraction techniques. In particular, the great
sensitivity of 119Sn NMR allows detecting subtle changes in
the immediate surroundings of the tin atom [5].
Complexes of TSC ligands with non-transition metals
such as tin have not received much attention, the majority
are organotin(IV) compounds, and reports of non-organo-
metallic tin complexes with thiosemicarbazones are scarce
in the literature. Most of the complexes reported are with
tridentate TSCs containing a pyridine ring, with the tin
* Dr. Antonia Mendiola
Departamento de Quımica Inorganica
Universidad Autonoma de Madrid
Cantoblanco 28049/Spain
Tel.: ϩ34 91 4974844
Fax: ϩ34 91 4974833
e-mail address: antonia.mendiola@uam.es
´
´
´
Z. Anorg. Allg. Chem. 2007, 633, 1925Ϫ1931
 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1925

´
D. G. Calatayud, E. Lopez-Torres, M. A. Mendiola, J. R. Procopio
Scheme 1
exception is the methyl mercury complex, in which only the
sulfur atoms are bonded to two methyl mercury moieties in
a binuclear structure [14].
hexanuclear structure. The triazine is only bonded through
the sulfur atom in the mercury complexes giving a linear
disposition for the mercury atom [20]. Here we report the
syntheses and characterization of new complexes obtained
by reaction of tin(IV) chloride with benzil bis(thiosemi-
carbazone) L1H6, benzil bis(4-methyl-3-thiosemicarbazone)
L1Me2H4 and the triazine ligands 5-methoxy-5,6-diphenyl-
4,5-dihydro-2H-[1,2,4]-triazine-3-thione, L2H2OMe and
5-methoxy-4-methyl-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-
triazine-3-thione, L2MeHOMe.
On the other hand, triazine derivatives have traditionally
found applications in analytical chemistry as complexation
agents, in electrochemistry as multi-step redox systems and
as pesticide or herbicide components in agriculture. In the
last years, there has been a growing interest in these com-
pounds that have been used, for example, as templates in
multidimensional crystal engineering involving metal com-
plexes for producing nanometre sized oligonuclear coordi-
nation compounds, as scaffold in combinatorial chemistry,
as well as new building blocks in peptidomimetics and as
anticancer agents [15, 16] Therefore, the synthesis of tin
compounds with triazines derived from thiosemicarbazides
is an interesting topic to pursue. We have characterized
complexes of 5-methoxy-5,6-diphenyl-4,5-dihydro-2H-
[1,2,4]-triazine-3-thione, L2H2OMe with divalent metal ni-
trates such as Co, Ni, Zn, Cd, Pb, as well as CuCl and some
diorganic tin(IV) compounds. In all of them the ligand has
lost a methanol molecule and an additional double CN
bond has been formed, acting as a monoanion L2 [17Ϫ19].
Those complexes are NS chelates, besides in Zn, Cd, Pb and
Cu derivatives the S atom acts as a bridge, giving binuclear
structures, except the copper(I) complex, which shows a
Results and Discussion
Proposed structures for the ligands and their tin (IV) com-
plexes are summarized in Schemes 1 and 2.
Formation of the tin(IV) complexes
All reactions were performed by mixing a suspension of
the ligands in dichloromethane with a solution of tin(IV)
chloride in the same solvent until a 1:1 or 1:2 mole ratio,
with an scarce excess of metal salt was reached.
Analytical data of the complexes prepared from the open
chain ligands, 1 and 2 indicate, respectively, a 2:1 and 1:1
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Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931

Tin(IV) Complexes with Thiosemicarbazide and 4-Methyl-3-thiosemicarbazide Derivatives
Scheme 2
molar ratio between the tin atom and the ligand as well as
that the chloride ions remain in both compounds (Scheme
1). The FABϩ mass spectra of the complexes show a peak
corresponding to the ligands and a peak corresponding to
[SnClL1H4]ϩ or [SnClL1Me2H2]ϩ, respectively. The FABϪ
spectrum of complex 1 suggests the presence of a halide
tin(IV) ion complex. The experimental isotopic distribution
for every peak fits the theoretical one.
The reactions with the cyclic ligands were carried out
with two different Sn:Ligand molar ratio (1:1 and 1:2). Re-
actions of L2H2OMe, gave only complex 3, while the reac-
tions with the 4-methyl-3-thiosemicarbazide derivative,
L2MeHOMe, allow to isolate two compounds, 4 and 5. The
analytical data of complexes 3 and 4 show a 1:1 Sn:Ligand
ratio, while a 1:2 ratio is observed for complex 5 (Scheme
2). Data for 3 indicate that the ligand has lost a methanol
molecule, as it happened in all of its complexes previously
characterized, which is consistent with the peak observed
in the mass spectrum. Analysis for complex 4 indicate that
one CH3 group has been lost. The FABϩ mass spectra of 4
and 5 only show peaks corresponding to the interaction of
the organic part of the complexes with the matrix used in
the experiments (m-NBA). EI-MAS spectra of 4 and 5
show peaks corresponding to the organic part of the com-
plexes, [L2H2OMe]ϩ and [L2MeHOMe]ϩ, respectively, con-
firming the loss of one methyl group in complex 4. The
MALDI-MS spectrum of 5 confirms a 1:2 Sn : Ligand
ratio.
All complexes are sensitive to the presence of moisture.
In addition, the mother liqueurs from the reactions with
L2MeHOMe change their colour in the presence of small
amounts of moisture and a crystalline solid is separated.
Its X-ray data confirms that the binuclear complex
[Sn2Cl6(OH)2(H2O)2]·3H2O was formed. This compound
was previously characterized by reaction of SnCl4 and
3-acetyl-5-benzyl-1-phenyl-4,4-dihydro-1,2,4-triazine-6-one
oxime in commercial CH2Cl2 [21].
Conductivity data of complexes in DMF indicate that the
open chain derivatives are electrolytes, while the triazine
complexes are molecular compounds [22].
Spectroscopic studies
The shifts observed in the IR spectra of complexes 1 and 2
with respect to the free ligands, indicate the coordination
to the tin atom through the imine nitrogen and the sulfur
atoms. In addition, both spectra show new bands corre-
sponding to the new bonds formed and the band expected
at low frequency corresponding to ν(Sn-Cl) in [SnCl6]2Ϫ
was observed in complex 1.
Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931
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D. G. Calatayud, E. Lopez-Torres, M. A. Mendiola, J. R. Procopio
Complexes 1 and 2 are sparingly soluble in the common
deuterated solvents except donor ones. H NMR spectrum
change. The spectrum was also registered at 10 KHz and
with a relaxation time of 20 s. The new spectrum shows an
additional peak at 83.3 ppm assignable to a CNOR2 carbon
atom. The position of the signals suggests that the ligand is
probably bonded by the imine nitrogen atom. The signals
observed agree with the substitution of the methyl group
bonded to the nitrogen atom by one hydrogen atom in the
reaction medium.The surprising changes observed in L2Me-
HOMe could be explained in base of an oxidative N-de-
alkylation of tertiary amines reaction, which can occur in
CH2Cl2 and in the presence of a small excess of tin(IV)
chloride, as it has been described in the literature under
oxidative conditions [24].
1
of 2 in acetone indicates the loss of one of the acidic amine
hydrogen, but in DMSO shows the partial decomposition
of the complex, therefore, 13C and 119Sn NMR in the solid
state were measured for both complexes. The 13C CP/MAS
NMR spectra show the signal corresponding to the thio-
amide carbons shifted to high field and those correspond-
ing to the imine carbon atoms shifted to low field. There-
fore, both groups are bonded to the tin atom and the ligand
acts as a chelate N2S2, as expected for both molecules. The
different stoichiometry of complexes 1 and 2 is reflected in
the number of carbon atoms in the 13C CP/MAS spectra.
These differences can be explained by the presence in the
complex 2 of two ligand molecules with an asymmetric
behaviour and/or by the formation of a binuclear structure,
as observed in the diphenyllead(IV) derivative [23].
It is well known that the 119Sn chemical shift is very sensi-
tive to changes in the coordination number of the tin atom
as well as to the nature of the bonding, so it is a useful tool
to determine the environment of this metal in a complex in
the absence of X-ray data. The signal of 119Sn spectra of
complexes recorded in DMF (see experimental part) are
found practically in the same positions (Ϫ631, Ϫ634 ppm),
and they are very close to that observed for SnCl4(DMF)2
(Ϫ630 ppm), indicating that the solvent is coordinated to
the metal atom displacing some atoms from the coordi-
nation sphere of the tin centre. The 119Sn CP/MAS spectra
of complexes 1 and 2 show two signals, the MAS spectra
obtained using a single pulse sequence with proton decoup-
ling, suggest a 1:1 ratio for the signals in both complexes.
The 119Sn chemical shifts observed in complex 1, Ϫ671 and
Ϫ728 ppm, are indicative of Sn(IV) in a hexacoordinate en-
vironment, the more negative value is consistent with the
presence of the [SnCl6]2Ϫ ion [25Ϫ28]. The lower value is in
the high range for this coordination number with a N2S2Cl2
coordination, where the presence of chloride ions leads to
a more negative value of the chemical shift, due to its induc-
tive effect and also the possibility of additional π-contri-
bution to the Sn-Cl bond, which would shield the nucleus
to a greater extent [29]. The signals observed in complex 2,
Ϫ659 and Ϫ718 ppm, fall between the ranges of hexacoor-
dinate or heptacoordinate tin(IV) complexes. In accordance
with the composition of this complex, the presence of two
tin(IV) atoms means the presence of two ligands. Taking
into account the number and position of the 13C signals
and the values of the 119Sn NMR spectra, complex 2 might
contain two Sn(IV) ions joined by sulfur bridges in a bi-
The IR spectrum of 3 confirms the loss of the secondary
amine hydrogen atom and the formation of an additional
CϭN bond. The shifts observed in the IR spectra of com-
plexes 3 and 5, with respect to the free ligands, indicate the
coordination to the tin atom through the sulfur atoms, be-
sides some new bands can tentatively be assigned to Sn-Cl
1
bonds. In the H NMR spectrum of 3 the absence of any
signal corresponding to the amine protons supports the
presence of L2. In addition, the loss of the methoxy group
is confirmed by the absence of the singlet corresponding to
1
the OCH3 moiety (δ ϭ 3.4). The H NMR spectrum of 4
in DMF-d6 shows signals indicating the partial decompo-
sition of the complex, but in DMSO-d6 two signals corre-
sponding to amine hydrogen atoms, one corresponding to
a methoxy group and the corresponding aromatic hydrogen
are observed. These data suggest that the CH3 bonded to
the nitrogen atom has been substituted by one hydrogen
atom.
In the 13C CP/MAS spectra of complexes derived from
the cyclic ligands (3 and 5), the shifts observed in the
thioamide carbon signals are indicative of coordination to
the tin centre through the sulfur atom in both complexes.
In the spectrum of complex 3, the absence of the carbon
atom of the OCH3 group and the additional signal in the
range for a double CN bond confirm the above proposed
modification. Therefore, in complex 3 the anionic ligand is
bonded through the amine and the thioamide groups acting
as a NS chelate as it was observed in the diorganotin com-
plexes with this ligand with the same stoichiometry [19].
The spectrum of 5 also indicates that the imine group is not
involved in the tin coordination. The coordination sphere
on tin(IV) might be completed by three chloride ions in
complex 3 and by four in complex 5 (Scheme 2). On the
other hand, the 13C CP/MAS spectrum of complex 4, re-
corded in the same conditions of all the other compounds,
shows signals at 172 ppm and 158 ppm, which correspond
to a thiocarbonyl and a imine carbon atoms, one signal
corresponding to the carbon atom of the OCH3 group, and
the absence of the quaternary and the methyl carbon atoms,
which suggests that the ligand has suffered an important
2Ϫ
nuclear structure, in a similar disposition than L1H4 in
2Ϫ
the cadmium complex [13] and as L1Me2H2 in the di-
phenyllead(IV) derivative [23]. In complex 2, one of the li-
gands acts as a dianion and the other one would be in the
neutral form. Therefore, one of the tin atoms would have
an octahedral coordination, S3Cl3 and the other S3N2Cl2
corresponding to the signals at Ϫ659 and Ϫ718 ppm respec-
tively (Scheme 1).
The 119Sn CP/MAS spectra of complexes 4 and 5 show
one signal at Ϫ612 and Ϫ672 ppm, respectively. It was not
possible to get a useful spectrum of complex 3. The pres-
ence of one signal agrees with a monomer structure or a
centrosymmetric dimeric structure for both complexes. The
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Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931

Tin(IV) Complexes with Thiosemicarbazide and 4-Methyl-3-thiosemicarbazide Derivatives
130.3, 129.1, 126.8 (Ph); δ ϭ 31.5 (CH3); 13C CP/MAS NMR (300 MHz,
values are in agreement with a NCl4 coordination in com-
plex 4 and with an octahedral coordination on the tin(IV)
atom with a S2Cl4 coordination sphere in complex 5.
25 °C): δ ϭ 177.2 (CS); δ ϭ 139.8 (CN); δ ϭ 130.6Ϫ124.7 (Ph); δ ϭ 32.1
(CH3). IR (KBr): ν(NH) 3435 and 3335 s, ν(CϭN) 1601 w, δ(HNC) 1546 s,
ν(CS) 845 w cmϪ1
5-methoxy-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]triazine-3-thione,
.
L2H2OMe
[34, 35] Selected spectroscopic data: FAB؉ (m/z): 266.2 ([M-OCH3]ϩ, 10 %),
298.2 ([Mϩ1]ϩ, 35 %). 1H NMR (CDCl3, 300 MHz 25 °C): δ ϭ 9.5 (1H,
NH, s); δ ϭ 7.6 (2H, Ph, m); δ ϭ 7.4 (2H, Ph, m); δ ϭ 7.3Ϫ7.1 (6H, Ph,
m); δ ϭ 6.9 (1H, NH, s); δ ϭ 3.4 (3H, OCH3, s). 13C NMR (CDCl3,
300 MHz, 25 °C): δ ϭ 169.7 (CS); δ ϭ 142.4 (CN); δ ϭ 141.7, 133.7, 129.3,
126.5 (Ph); δ ϭ 83.2 (CNOR2); δ ϭ 50.7 (CH3O). 13C CP/MAS NMR
(300 MHz, 25 °C): δ ϭ 168.4 (CS); δ ϭ 146.0 143.4 (CN); δ ϭ 132.4, 131.3,
129.8. 127.0 (Ph); δ ϭ 85.4 (CNOR2); δ ϭ 53.4 (CH3O). IR (KBr): ν(NH)
Experimental Section
Physical Methods
IR spectra in the 4000-400 cmϪ1 range were recorded as KBr pel-
lets on
a Jasco FT/IR-410 spectrophotometer, and in the
3184 s and 3131 s, ν(CϭN) 1608 w, δ(NCS) 1550 s, ν(CS) 846 w cmϪ1
.
560Ϫ20 cmϪ1 range on a FT-IR Bruker IFS60v one. 1H and 13C
NMR spectra were recorded on a spectrometer Bruker AMX-300
using DMSO-d6, CDCl3, acetone-d6, methanol-d4 or DMF-d6 as
solvents and TMS as internal reference. 119Sn NMR spectra
were recorded in the same spectrometer using DMF-d6 or
DMFϩCDCl3 as solvents and using absolutes references [30]. Solid
state NMR spectra were recorded at 298 K in a Bruker AV400WB
spectrometer equipped with a 4 mm MAS-NMR probe (magic-
angle spinning). 13C CP/MAS NMR was obtained usingcross-pola-
rization pulse sequence. The external magnetic field was 9.4 T and
the sample was spun at 10 Ϫ 14 KHz, spectrometer frequencies
were set to 100.61 MHz. For the recorded spectra a contact time
of 4 ms were used and recycle delays of 4 s were used. Spectrum of
complex 4 also was registered at 10 KHz with a relaxation time of
20 s. Chemical shifts are reported relative to TMS, using the CH
group of adamantano as a secondary reference (29.5 ppm) [31].
119Sn MAS NMR spectra were recorded at 149.1 MHz, on a
Bruker AV 400 WB spectrometer equipped with a 4 mm MAS-
NMR probe (magic-angle spinning). Spectra were taken on
samples spinning at a rate of 5, 10 and 12 kHz in two ways: using
a single pulse sequence of 3 µs 119Sn 40° with TPPM proton de-
coupling followed by a relaxation delay of 40-60 s and with CP
sequence. The 119Sn-1H Hartmann-Hahn conditions were op-
timised with tetraphenyltin. The CP-MAS spectra were obtained
using spinning rates of 10 KHz, pulse delays of 30 s, contact times
of 8 ms and TPPM high power proton decoupling. Chemical shifts
are reported relative to tetramethyltin, using tin(IV) oxide as a sec-
ondary reference (Ϫ604.3 ppm) [32].
5-methoxy-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]triazine-3-thione, L2MeHOMe
[33]: Selected spectroscopic data: FAB؉ (m/z): 77.0 ([C6H5]ϩ, 9 %), 105.1
([C7H6Nϩ1]ϩ, 20 %), 118.1 ([C7H6N2]ϩ, 8 %), 280.2 ([C16H14N3S]ϩ, 13 %),
312.2 ([Mϩ1]ϩ, 100 %), 622.5 ([2Mϩ1]ϩ, 10 %). 1H NMR (DMSO-d6,
300 MHz, 25 °C): δ ϭ 12.3 (1H, NH, s); δ ϭ 7.5Ϫ7.2 (10H, Ph, m); δ ϭ 3.2
(3H, OCH3, s); δ ϭ 2.9 (3H, CH3, s). 1H NMR (CDCl3, 300 MHz, 25 °C):
δ ϭ 9.5 (1H, NH, s); δ ϭ 7.6Ϫ7.1 (10H, Ph, m); δ ϭ 3.4 (3H,OCH3, s); δ ϭ
3.1 (3H, CH3, s). 13C NMR (DMSO-d6, 300 MHz 25 °C): δ ϭ 171.7 (CS);
δ ϭ 141.4 (CN), δ ϭ 139.9, 133.7, 129.3, 128.8, 127.9, 126.8, 126.4 (Ph); δ ϭ
87.1 (CNOR2); δ ϭ 51.1 (OCH3); δ ϭ 33.3 (CH3). 13C CP/MAS NMR
(300 MHz, 25 °C): δ ϭ 173.1 (CS); δ ϭ 146.1 (CN); δ ϭ 140.4, 135.1, 129.4,
128.6, 126.6 (Ph); δ ϭ 87.8 (CNOR2); δ ϭ 52.0 (OCH3); δ ϭ 37.1 (NCH3).
IR (KBr): ν(NH) 3229 s, ν(CN) 1589 w, δ(NCS) 1511 s, ν(CS) 845 w cmϪ1
.
Synthesis of complexes
All the reactions were carried out under Ar atmosphere and the
dichloromethane (DCM) was dried by refluxing over CaH2.
[SnL1H6Cl2][SnCl6] (1): Over
a
suspension of L1H6 (0.20 g,
0.56 mmol) in 50 mL of dichloromethane were added dropwise and
in the presence of argon 4 mL (0.69 mmol) of SnCl4 solution in
DCM (1 mL /49 mL). This solution was used for the synthesis of all
of the coordination compounds. The mixture was stirred at room
temperature for 12 h. The yellow solid formed was filtered off
under argon atmosphere, washed with DCM and dried in vacuo.
Yield 95 %. Mp 220 °C. ΛM (DMF, ΩϪ1cm2mlϪ1): 103. Anal. Calc.
for C16H16N6S2Cl8Sn2: C, 22.83; H, 1.80; N, 9.98; S, 7.60; Found:
C, 23.28; H, 2.08; N, 10.16; S, 7.61 %.
FAB؉ (m/z): 357.0 ([L1H6ϩ1]ϩ, 25 %), 508.8 ([SnClL1H4]ϩ, 100 %). FAB؊
(m/z): 296.8 ([SnCl5]Ϫ, 48 %). 13C CP/MAS NMR (300 MHz, 25 °C): δ ϭ
174.2 (CS); δ ϭ 156.0 (CN); δ ϭ 136.0, 133.3, 130.9, 128.0, 126.2 (Ph). IR
(KBr): ν(NH) 3459, 3347, 3270, 3186 s, ν(CϭN) 1612 w, δ(NH2) 1541 s,
EI and fast atom bombardment (FAB) mass spectra were recorded
on a VG Auto Spec instrument using Cs as the fast atom and
m-nitrobenzylalcohol (mNBA) as the matrix in the FAB experi-
ment. Conductivity data were measured using freshly prepared
DMF solutions (ca. 10Ϫ3 M) at 25 °C with a Metrohm Herisau
model E-518 instrument.
.
δ(NCS) 1416 s, ν(CS) 809 w, ν(SnCl) 303 w, cmϪ1 119Sn CP/MAS NMR
(300 MHz, 25 °C): δ ϭ Ϫ670.9, Ϫ728.3.
[Sn2L1Me2H4L1Me2H2Cl5]Cl.CH2Cl2 (2): 4 mL (0.69 mmol) of the
SnCl4 solution were added over a solution of L1Me2H4 (0.22 g,
0.56 mmol) in 50 mL of DCM. The mixture was stirred for 6 h and
the pale orange solid formed was filtered off washed with DCM
and dried in vacuo. Yield 80 %. Mp 227 °C. ΛM (DMF,
Spectroscopic data of organic molecules
Benzil bis(thiosemicarbazone), L1H6 [11]: Selected spectroscopic data: FAB؉
(m/z): 357 ([M ϩ 1]ϩ, 100 %), 714 ([2M ϩ 1]ϩ, 25 %). 1H NMR (DMSO-d6,
300 MHz, 25 °C): δ ϭ 9.8 (2H, NH, s); δ ϭ 8.6 (2H, NH, s); δ ϭ 8.3 (2H,
NH, s); δ ϭ 7.7 (4H, Ph, m); δ ϭ 7.4 (6H, Ph, m). 1H NMR (CDCl3,
300 MHz, 25 °C): δ ϭ 8.8 (2H, NH, s); δ ϭ 7.6 (6H, Ph, m); δ ϭ 7.4 (4H,
Ph, m); δ ϭ 6.6 (2H, NH, s); δ ϭ 6.0 (2H, NH, s). 13C NMR (DMSO-d6,
300 MHz, 25 °C): δ ϭ 179.1 (CS); δ ϭ 140.5 (CN); δ ϭ 133.1, 130.1, 128.9,
126.8 (Ph). 13C CP/MAS NMR (300 MHz, 25 °C): δ ϭ 181.1 (CS); δ ϭ 142.9
(CN); δ ϭ 133.3, 132.4 130.1 (Ph). IR (KBr): ν(N-H) 3420, 3386, 3342, 3330,
Ω
Ϫ1cm2mlϪ1): 60. Anal. Calc. for C37H40N12S6Cl8Sn2: C, 34.11; H,
3.07; N, 12.90; S, 9.83; Sn, 18.28; Found: C, 33.92; H, 3.10; N,
12.64; S, 9.51; Sn, 18.87 %.
FAB؉ (m/z): 385.1 ([L2Me2H4ϩ1]ϩ, 15 %), 537.0 ([SnClL2Me2H2]ϩ, 30 %)
and 572 ([SnCl2L2Me2H3]ϩ, 5 %). 1H NMR (acetone-d6, 300 MHz,
25 °C):δ ϭ 9.2 (s, 1.5H, NH); δ ϭ 8.7 (s, 1.5 H, NH); δ ϭ 7.8 (m, 4H, Ph);
δ ϭ 7.4 (m, 10H, Ph); δ ϭ 5.6 (s, 2H, CH2Cl2); δ ϭ 3.2 (d, 6H, CH3). 13C
CP/MAS NMR (300 MHz, 25 °C): δ ϭ 175.1, 171.8, 169.6 (CS); δ ϭ 152.8,
148.6 (CN); δ ϭ 134.7, 133.2, 131.2, 129.9, 128.2 (Ph); δ ϭ 33.8 (CH3). IR
(KBr): ν(NH) 3302 s, 3167 s, ν(CϭN) 1696 w, δ(HCN) 1585 s, 1579 s,
δ(NCS) 1509 s, ν(CS) 906 w, 847 w, ν(SnCl), ν(SnL) several bands 320-280 s
3210, 3151 s, ν(CϭN) 1608 w, δ(NH2) 1581 s and ν(CS) 848 w cmϪ1
.
Benzil bis(4-methyl-3-thiosemicarbazone), L1Me2H4 [33]: Selected spectro-
scopic data: FAB؉ (m/z) 385.2 ([Mϩ1]ϩ, 80 % ), 769.6 ([2Mϩ1]ϩ, 10 %). 1H
NMR (DMSO-d6, 300 MHz, 25 °C): δ ϭ 9.8 (2H, NH, s); δ ϭ 8.9 (2H, NH,
q); δ ϭ 7.7 (4H, Ph, m); δ ϭ 7.4 (6H, Ph, m); δ ϭ 3.0 (6H, CH3, d). 1H
NMR (CDCl3, 300 MHz, 25 °C): δ ϭ 8.5 (2H, NH, s); δ ϭ 7.8 (2H, NH, q);
δ ϭ 7.7 (4H, Ph, m); δ ϭ 7.3 (6H, Ph, m); δ ϭ 3.3 (6H, CH3, d). 13C NMR
(DMSO-d6, 300 MHz, 25 °C): δ ϭ 178.6 (CS); δ ϭ 140.4 (CN); δ ϭ 133.2,
cmϪ1 119Sn NMR (DMF ϩ CDCl3, 25 °C): δ ϭ Ϫ634.5 ppm. 119Sn CP/
.
MAS NMR (300 MHz, 25 °C): δ ϭ Ϫ658.7 and Ϫ718.2.
[SnL2Cl3].CH2Cl2 (3): 5 mL (0.87 mmol) of the SnCl4 solution were
added over L2H2OMe (0.20 g, 0.67 mmol). Immediately, a golden
Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931
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www.zaac.wiley-vch.de
1929

´
D. G. Calatayud, E. Lopez-Torres, M. A. Mendiola, J. R. Procopio
yellow solution was formed and then was stirred for 24 h at room
temperature. An orange solid was formed by slow evaporation of
the solvent. The solid was filtered and dried in vacuo. Yield 76 %.
M.p. 178 °C. ΛM (DMF, ΩϪ1cm2mlϪ1): 30. Anal. Calc. for
C16H12N3SCl5Sn: C, 34.24; H, 2.14; N, 7.50; S, 5.71; Found: C,
33.95; H, 2.17; N, 7.70; S, 5.46 %.
[3] D. X. West, S. B. Padhye, P. B. Sonawane, Struct. Bonding
[Berlin] 1991, 76, 1.
[4] J. G. Cory, A. H. Cory, Eds., International Encyclopaedia of
Pharmacology and Therapeutics, Pergamon Press, New York
1989.
[5] C. Camacho-Camacho, R. Contreras, H. Nöth, M.
Bechmann, A. Sebald, W. Milius, B. Wrackmeyer, Mag. Reson.
Chem. 2002, 40, 31.
FAB؉ (m/z): 266.0 ([L2ϩ1]ϩ, 95 %), 419.0 ([SnL2HCl ϩ1]ϩ, 5 %), 453.8
([SnL2Cl2]ϩ, 4 %), 489.7 ([Mϩ1]ϩ, 7 %). 1H NMR (acetone- d6, 300 MHz,
25 °C): δ ϭ 7.7- 7.4 (Ph); δ ϭ 5.6 (s, 2H, CH2Cl2). 13C NMR (methanol-d4,
300 MHz, 25 °C): δ ϭ 170.0 (CS); δ ϭ 150.0, 143.1 (CN); δ ϭ 130.3, 129.6,
129.3, 129.0, 127.8 (Ph). 13C CP/MAS NMR (300 MHz, 25 °C): δ ϭ 171.0
(CS); δ ϭ 164.1, 152.6 (CN); δ ϭ 139.0, 130.3, 129.6, 129.3, 129.0, 127.8
´
[6] A. Perez-Rebolledo, G. M. de Lima, N. L. Speziali, O. E. Piro,
E. E. Castellano, J. D. Ardisson, H. Heraldo, J. Organomet.
Chem. 2006, 691, 3919.
[7] M. Akbar Ali, A. H. Mirza, M. H. S. A. Hamid, F. H. Bujang,
P. V. Bernhardt, Polyhedron 2004, 23, 2405.
(Ph). IR (KBr): ν(CϭN) 1596, 1580 w, ν(CNS) 1493, ν(CS) 800 cmϪ1
.
The same compound was obtained when the reaction was carried
out with a 1:2 tin : ligand ratio
[8] E. Block, G. Ofori-Okai, H. Kang, J. Wu, J. Zubieta, Inorg.
Chim. Acta 1991, 190, 5.
´
´
[9] A. Sousa-Pedrares, M. I. Casanova, J. A. Garcıa-Vazquez, M.
[SnL2H2OMeCl4] (4): 5 mL (0.87 mmol) of the SnCl4 solution were
added over L2MeHOMe (0.21 g, 0.67 mmol). Immediately, an in-
tense orange solution was formed, which was stirred for 6 h at room
temperature. A microcrystalline orange solid was formed overnight
and it was separated by filtration. Yield 72 %. M.p. 235 °C. ΛM
(DMF, ΩϪ1cm2mlϪ1): 14. Anal. Calc. for C16H15N3SOCl4Sn: C,
34.42; H, 2.67; N, 7.53; S, 5.76; Sn, 21.27; Found: C, 35.27; H,
2.67; N, 7.66; S, 5.85; Sn, 21.55 %.
´
L. Duran, J. Romero, A. Sousa, J. Silver, P. J. Titler, Eur. J.
Inorg. Chem. 2003, 678.
´
[10] E. Lopez-Torres, A. R. Cowley, J. R. Dilworth, Inorg. Chem.
Commun. 2007, 10, 724.
´
´
[11] E. Lopez-Torres, M. A. Mendiola, J. Rodrıguez-Procopio, M.
T. Sevilla, E. Colacio, J. M. Moreno, I. Sobrados, Inorg. Chim.
Acta 2001, 323, 130.
[12] D. G. Calatayud, E. Lopez-Torres, M. A. Mendiola, C. J.
Pastor, J. R. Procopio, Eur. J. Inorg. Chem. 2005, 4401.
[13] E. Lopez-Torres, M. A. Mendiola, C. J. Pastor, B. Souto Perez,
´
EI؊MS (m/z): 297.0 ([L2H2OMe]ϩ, 60 %). 1H NMR (DMF-d6, 300 MHz,
25 °C): δ ϭ 12.0 (1.5 H, NH, s);δ ϭ 8.1 (1 H, NH, s); δ ϭ 7.7- 7.1 (24 H,
Ph, m); δ ϭ 3.8 (4H, CH3 , s); δ ϭ 3.1 (3H, CH3, s). 1H NMR (DMSO-d6,
300 MHz, 25 °C): δ ϭ 11.9 (1H, NH, s); δ ϭ 8.2 (1 H, NH, s); δ ϭ 7.6Ϫ7.1
(10 H, Ph, m); δ ϭ 2.9 (3H, CH3, s). 13C CP/MAS NMR (300 MHz, 25 °C):
δ ϭ 171.8 (CS); δ ϭ 158.0 (CN); δ ϭ 133.6, 131.5, 129.5, 127.4, 125.9 (Ph);
δ ϭ 49.1 (OCH3). 13C CP/MAS NMR (t ϭ 20 s): δ ϭ 171.8 (CS); δ ϭ 158.0
(CN); δ ϭ 133.7, 131.5, 129.6, 128.8, 127.4, 125.9 (Ph); δ ϭ 83.3; δ ϭ 49.1
(OCH3). IR (KBr): ν(CϭN) 1597 w, ν(CNS) 1497 s, ν(CS) 847 w, ν(SnCl)
´
´
Inorg. Chem. 2004, 43, 5222 and refs. therein.
´
[14] E. Lopez-Torres, D. G. Calatayud, M. A. Mendiola, C. J.
Pastor, J. R. Procopio, Z. Anorg. Allg. Chem. 2006, 632, 2471.
[15] G. Giacomelli, A. Porcheddu, L. Luca, Curr. Org. Chem. 2004,
8, 1497.
[16] Z. Brzozowski, F. Saczewski, M. Gdaniec, Eur. J. Med. Chem.
2000, 35, 1053.
312 w cmϪ1
.
119Sn NMR (DMF-d6, 300 MHz, 25 °C): δ ϭ Ϫ633.0. 119Sn
CP/MAS NMR (300 MHz, 25 °C): δ ϭ Ϫ612.1.
´
[17] E. Lopez-Torres, M. A. Mendiola, Polyhedron 2005, 24, 1345.
[Sn(L2MeHOMe)2Cl4] (5): 2 mL (0.33 mmol) of the SnCl4 solution
were added over L2MeHOMe (0.22 g, 0.67 mmol). Immediately, an
orange solution was formed that was stirred for 6 h at room tem-
perature. A yellow solid was formed by slow evaporation of the
solvent; it was filtered off and dried in vacuo. Yield 64 %. M.p.
191 °C. ΛM (DMF,
C34H34N6S2Cl4Sn: C, 46.20; H, 3.80; N, 9.51; S, 7.24; Sn, 13.40;
Found: C, 45.48; H, 3.75; N, 9.42; S, 7.34; Sn, 13.50 %.
EI-MS (m/z): 280.0 ([L2MeH]ϩ, 20 %), 311.0 ([L2MeHOMe]ϩ, 63 %).
´
[18] E. Lopez-Torres, M. A. Mendiola, C. J. Pastor, Inorg. Chem.
2006, 3103.
´
[19] E. Lopez-Torres, M. A. Mendiola, C. J. Pastor, J. R. Procopio,
Eur. J. Inorg. Chem. 2003, 2711.
´
[20] E. Lopez-Torres, M. A. Mendiola, C. J. Pastor, Polyhedron
Ω
Ϫ1cm2mlϪ1): 16. Anal. Calc. for
2006, 25, 1464.
[21] A-F. Shihada, A. S. Abushamleh, F. Weller, Z. Anorg. Allg.
Chem. 2004, 630, 841.
[22] W. J. Geary, Coord. Chem. Rev. 1971, 7, 81.
MALDI-MS
(m/z):
430.0
([Sn(L2MeOMe)]ϩ,
20 %),
774.9
a
´
[23] D. G. Calatayud, E. Lopez-Torres, M . A. Mendiola, J. R.
([Sn(L2MeOMe)2Cl]ϩ, 15 %). 13C CP/MAS NMR (300 MHz, 25 °C): δ ϭ
163.1 (CS); δ ϭ 145.6 (CN); δ ϭ 139.0, 132.9, 130.6, 129.2, 128.2, 126.2
(Ph); δ ϭ 89.2 (CNOR2); δ ϭ 52.4 (OCH3); δ ϭ 36.9 (NCH3). IR (KBr):
ν(CϭN) 1610, 1594 w, ν(CNS) 1490 s, ν(CS) 843 w, ν(SnCl) 312 w, ν(SnCl)
Procopio, Inorg. Chem., to be submitted.
[24] S-I. Murahashi, T. Naota, K. Yonemura, J. Am. Chem. Soc.
1988, 110, 8256.
[25] J. D. Kennedy, W. McFarlane in: Multinulear NMR, J. Mason
(ed), 1987.
298 w cmϪ1 119Sn NMR (DMFϩCDCl3, 300 MHz, 25 °C): δ ϭ Ϫ634.3.
.
119Sn CP/MAS NMR (300 MHz, 25 °C): δ ϭ Ϫ672.1.
[26] K. B. Dillon, A. Marshall, J. Chem. Soc., Dalton Trans.
1987, 315.
[27] S. J. Langford, M. J. Latter, J. Beckmann, Inorg. Chem. Com-
mun. 2005, 8, 920Ϫ923.
[28] C. Pettinari, F. Marchetti, A. Cingolani, D. Leonesi, E. Mur-
dorff, M. Mundorff, M. Rossi, F. Caruso, J. Organomet.
Chem. 1998, 557, 187.
Acknowledgements. We thank Ma Jose de la Mata of “Servicio
´
´
´
Interdepartamental de Investigacion, Universidad Autonoma de
Madrid” for her helpful comments on solid state NMR spectra.
We also thank DGICYT for financial support (Project CT2005-
´
07788/BQU) and to Universidad Autonoma de Madrid for a grant
to David G. Calatayud.
[29] C. Pettinari, F. Marchetti, R. Pettinari, D. Martini, A. Droz-
dov, S. Troyanov, Inorg. Chim. Acta 2001, 325, 103.
[30] R. K. Harris, E. D. Becker, S. M. Cabral De Menezes, R.
Goodfellow, P. Granger, Pure Appl. Chem. 2001, 73, 1795.
[31] D. L. Bryce, G. M. Bernard, M. Gee, M. D. Lumsden, K.
Eichele, R. E. Wasylishen, Can. J. Anal. Sci. Spectrosc. 2001,
2, 46 and refs. therein.
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www.zaac.wiley-vch.de
 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931

Tin(IV) Complexes with Thiosemicarbazide and 4-Methyl-3-thiosemicarbazide Derivatives
´
[34] A. Arquero, M. Can˜adas, M. Martınez-Ripoll, M. A. Mendi-
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Z. Anorg. Allg. Chem. 2007, 1925Ϫ1931
 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
1931