Mercapto derivatives of triorganotin Y,C,Y-pincer complexes: Role of Y,C,Y-chelating ligands in a new coordination mode of organotin compounds

Article abstract of DOI:10.1016/j.jorganchem.2007.04.006

We report the use of triorganotin fragments R₂L^1-2Sn containing N,C,N and O,C,O-ligands L^1-2(L¹ = C₆H₃(Me₂NCH₂)₂-2,6^-, L² = C₆H₃(^tBuOCH₂)₂-2,6^-) on stabilization of both thiol-form in R₂L^1-2Sn-2-SPy (2-SPy = pyridine-2-thiolate) and thione-form in R₂L^1-2Sn(mimt) (mimt = 1-methylimidazole-2-thiolate) of the polar groups. Treatment of ionic organotin compounds [Me₂L¹Sn]⁺[Cl]^- (1) and [Ph₂L²Sn]⁺[OTf]^- (2) with appropriate sodium salts Na-2-SPy and Na(mimt) resulted in the isolation of Me₂L¹Sn-2-SPy (3), Ph₂L²Sn-2-SPy (4), Me₂L¹Sn(mimt) (5), Ph₂L²Sn(mimt) (6). While polar group 2-SPy exists in its thiol-tautomeric form in compounds 3 and 4, the second polar group (mimt) has been stabilized as the thione-tautomeric form by triorganotin fragments R₂L^1-2Sn in compounds 5 and 6. The products were characterized by ¹H, ¹³C and ¹¹⁹Sn NMR and IR spectroscopy, ESI/MS, elemental analyses and structures of 3, 6 were determined by X-ray diffraction study. The reactivity of compound 4 containing non-coordinated nitrogen atom of 2-SPy polar group towards CuCl and AgNO₃ is also reported. The reactions led to isolation of organotin compounds Ph₂L²SnCl (7) and Ph₂L²SnNO₃ (8) as the result of polar group transfer. The mechanism of this reaction has been investigated and compounds Ph₃Sn-2-SPy (9) and Ph₂L²Sn-4-SPy (10) (4-SPy = pyridine-4-thiolate) have been prepared for this purpose.

Full text of DOI:10.1016/j.jorganchem.2007.04.006

Journal of Organometallic Chemistry 692 (2007) 3415–3423
www.elsevier.com/locate/jorganchem
Mercapto derivatives of triorganotin Y,C,Y-pincer complexes: Role
of Y,C,Y-chelating ligands in a new coordination mode
of organotin compounds
a
a
b
a
a,
*
˚
ˇ
´
´
ˇ
Jana Martincova , Libor Dostal , Jan Taraba , Ales Ruzˇicka , Roman Jambor
a
ˇ
Department of General and Inorganic Chemistry, University of Pardubice, na´m. Cs. legiı 565, CZ-532 10, Pardubice, Czech Republic
´
b
Department of Inorganic Chemistry, Faculty of Science, Masaryk University of Brno, Kotla´rˇska´ 2, CZ-611 37, Brno, Czech Republic
Received 5 February 2007; received in revised form 27 March 2007; accepted 10 April 2007
Available online 14 April 2007
Abstract
We report the use of triorganotin fragments R2L1-2Sn containing N,C,N and O,C,O-ligands L1-2(L1 = C6H3(Me2NCH2)2-2,6ꢀ,
L2 = C6H3(tBuOCH2)2-2,6ꢀ) on stabilization of both thiol-form in R2L1-2Sn-2-SPy (2-SPy = pyridine-2-thiolate) and thione-form in
R2L1-2Sn(mimt) (mimt = 1-methylimidazole-2-thiolate) of the polar groups. Treatment of ionic organotin compounds [Me2L1Sn]+[Cl]ꢀ
(1) and [Ph2L2Sn]+[OTf]ꢀ (2) with appropriate sodium salts Na-2-SPy and Na(mimt) resulted in the isolation of Me2L1Sn-2-SPy (3),
Ph2L2Sn-2-SPy (4), Me2L1Sn(mimt) (5), Ph2L2Sn(mimt) (6). While polar group 2-SPy exists in its thiol-tautomeric form in compounds
3 and 4, the second polar group (mimt) has been stabilized as the thione-tautomeric form by triorganotin fragments R2L1-2Sn in com-
1
pounds 5 and 6. The products were characterized by H, 13C and 119Sn NMR and IR spectroscopy, ESI/MS, elemental analyses and
structures of 3, 6 were determined by X-ray diffraction study. The reactivity of compound 4 containing non-coordinated nitrogen atom
of 2-SPy polar group towards CuCl and AgNO3 is also reported. The reactions led to isolation of organotin compounds Ph2L2SnCl (7)
and Ph2L2SnNO3 (8) as the result of polar group transfer. The mechanism of this reaction has been investigated and compounds Ph3Sn-
2-SPy (9) and Ph2L2Sn-4-SPy (10) (4-SPy = pyridine-4-thiolate) have been prepared for this purpose.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Organotin; Chelating ligands; NMR; Crystal structure
1. Introduction
donor atom (D) is most commonly the nitrogen atom (N)
and these ligands are known to possibly exist in two tauto-
meric thione and thiol forms (Chart 1) [4].
Organotin compounds containing various mercapto
groups are extensively studied for their biological activities,
most importantly as antitumor agents and their in vitro
potency against trypanozoma cultures was demonstrated
too [1]. These compounds containing covalent Sn–S bond
are also studied for industrial use, namely as stabilizers
for polyvinyl chlorides [2]. An interesting class of organotin
mercapto derivatives comprises those of general formula
R3Sn(SR0), where R0 contains a donor atom (D) capable
of forming a secondary bond with a tin atom [3]. This
In organotin compounds, at least three bonding modes
between ligand SR0 and tin atom are conceivable (Chart
2) [5]. While the coordination with exo cyclic sulfur can
be found in every kind of tetrahedral monomeric structures
(A) [6], the coordination with endo cyclic nitrogen atom is
not common for tin (B), but it is often found in zinc com-
pounds. The N,S coordination is commonly observed in
tri- or diorganotin compounds (C) and the coordination
polyhedra of these compounds are thus intermediate
between tetrahedron and trigonal bipyramid, where the
strength of the Sn–N bond determines the degree of distor-
tion [7].
*
Corresponding author. Fax: + 420 466037068.
E-mail address: roman.jambor@upce.cz (R. Jambor).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.04.006

3416
J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
Chart 1.
Scheme 1. Preparation of compounds 3–6.
The values of d(119Sn) in 3 (ꢀ95.0 ppm), 4 (ꢀ141.9
ppm), 5 (ꢀ124.04 ppm) and 6 (ꢀ173.53 ppm) are typical
for five coordinated central tin atom in molecular nonionic
triorganotin compounds [10–12] (compare with the values
of the ionic compounds 1 (14.5 ppm) and 2 (ꢀ25.8 ppm))
and they are shifted upfield compared to Et2Sn(-2-SPy)2
(ꢀ116.0 ppm), Ph3Sn-2-SPy (ꢀ116.3 ppm) and Ph3Sn-
(mimt) (ꢀ112.2 ppm) [13–15]. The values of 2J(119Sn,
1H(Me)) = 64 Hz for 3, 63.5 Hz for 5 and 1J(119Sn,
13C(1)) = 692 Hz for 4 and 713 Hz for 6 together with cal-
culated bond angles C–Sn–C (115ꢁ for 3, 119ꢁ for 4, 115ꢁ
for 5 and 120ꢁ for 6) indicate distorted trigonal bipyrami-
dal configuration at the tin atoms in 3–6 [16]. Dynamic
Chart 2.
In connection with our previous studies that were
focused on hypercoordinated organotin derivatives of
Y,C,Y-coordinating pincer-type ligands containing cova-
lent bond Sn–X, where X was a monodentate polar group
that could not affect the geometry of the central tin atom
[8], we decided to prepare triorganotin compounds con-
taining 2-mercaptopyridine (H-2-SPy) and 2-mercapto-1-
methylimidazole (Hmimt). These polar groups contain a
mercapto group and nitrogen donor atom capable of
forming an additional coordination bond. Our preliminary
results showed the possibility of stabilizing of a new thione-
form of (mimt) polar group by triorganotin fragment
[9]. To extend our study, we have used triorganotin
fragments R2L1-2Sn containing N,C,N (hereafter referred
to as L1) and O,C,O (hereafter referred to as L2) – ligands
(L1 = C6H3(Me2NCH2)2-2,6ꢀ, L2 = C6H3(tBuOCH2)2-2,6ꢀ)
on the stabilization of both thiol-form in R2L1-2Sn-2-SPy (2-
SPy = pyridine-2-thiolate) and thione-form in R2L1-2Sn-
(mimt) (mimt = 1-methylimidazole-2-thiolate). The prepared
compounds Me2L1Sn-2-SPy (3), Ph2L2Sn-2-SPy (4),
Me2L1Sn(mimt) (5), Ph2L2Sn(mimt) (6) were characterized
by 1H, 13C and 119Sn NMR and IR spectroscopy, ESI/MS,
elemental analyses and the structures of 3 and 6 were deter-
mined by X-ray diffraction study. The reactivity of com-
pound 4 containing non-coordinated nitrogen atom of 2-
SPy polar group towards CuCl and AgNO3 is reported
as well. The reactions resulted to isolation of organotin
compounds Ph2L2SnCl (7) and Ph2L2SnNO3 (8) as the
result of polar group transfer. The mechanism of this reac-
tion has been investigated and compounds Ph3Sn-2-SPy (9)
and Ph2L2Sn-4-SPy (10) (4-SPy = pyridine-4-thiolate) have
been prepared for this purpose.
1
behavior of 3–6 was studied by H NMR spectroscopy at
various temperatures (200–300 K, toluene-d8) and showed
non-equivalence of CH2YR groups in 3–6 at low tempera-
tures (decoalescence of CH2 a CH3 signals at 250 K for 3, 4
and 6 and at 220 K for 5).
Those data, however, do not predict the way in which the
polar group is bonded to the organotin fragment. The 13C
NMR spectra and especially the value of C2 chemical shift
(see Tables 1 and 2) are a very informative tool to deter-
mine, whether the polar group is stabilized in thione or thiol
tautomeric form.
The value of d(13C(C2)) = 177.7 ppm could be found
when H-2-SPy is in its thione form [17], while the value of
164.2 ppm was found in organotin compound Ph2SnCl-2-
Table 1
Selected values of d(13C) found in free ligand (existing as thione form), 3, 4
and Ph2SnCl-2-SPy (thiol form)
Compound/signala
C(2)
C(3)
C(4)
C(5)
C(6)
177.7
133.0
137.0
112.0
137.0
C4 C3
C5
C2
S
C6
N
2. Result and discussion
H
3
4
165.2
161.6
121.3
124.1
135.2
129.7
117.6
118.7
148.3
147.7
2.1. Solution and solid state studies of 3–6
C4 C3
Compounds 3–6 were prepared by treatment of the ionic
organotin compounds [Me2L1Sn]+[Cl]ꢀ (1) and [Ph2L2Sn]+
[OTf]ꢀ (2) with the appropriate sodium salts Na-2-SPy and
Na(mimt) (Scheme 1) [8].
C5
C2
S
164.2
123.7
139.7
119.5
146.2
C6
N
SnPh2Cl
a
Measured in CDCl3.

J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
3417
Table 2
Selected values of d(13C) found in free ligand (existing as thione form), 5, 6
and Ph3Sn(mimt) (thiol form) [15]
Compound/signala
C(2)
C(4)
C(5)
N–CH3
34.0
160.2
114.0
118.7
H
N3
C4
C2
S
C5
N1
CH3
5
162.8
163.5
118.8
120.2
118.8
121.4
34.6
34.8
Chart 3.
6
N3
C2
N1
C4
C5
of both compounds can be thus described as trans-trigonal
bipyramid with carbon atoms in equatorial plane, one
donor atom of Y,C,Y-chelating ligand and sulfur atom in
axial positions (see Fig. 1).
S
138.7
119.9
119.9
34.2
SnPh3
CH3
On the other hand, the 13C NMR spectra of 5 and 6
showed the polar group (mimt) is stabilized in a thione
form in solution. While the value of d13C(2) 160.2 ppm
indicated the presents of thione form of (mimt) in solution
[15,19], the value of 138.7 ppm could be found in the case
of its thiol form (i.e. upfield shift, see Table 2). The 13C
NMR data revealed broad signal of C2 at 162.8 ppm for
5 and 163.5 ppm for 6 that are comparable to the same sig-
nal of C2 in free ligand (Hmimt) (d13C(C2) = 160.2 ppm)
existing in the thione form in solution (see Table 2).
To the best of our knowledge, such a stabilization of the
thione form of this ligand has been reported in several
organotin cations (d13C(C2) = 157.0 ppm), where a free
ligand (Hmimt) has been used as the S-donor ligand for
organotin cations resulting in the Sn–S bond (Chart 3) [20].
The stabilization of thione form of the anionic polar
group (mimt)ꢀ by organotin compounds is unknown so
far (but is usual in organozinc or thalium compounds)
and results to the presence of Sn–N covalent bond in 5
and 6 (see Fig. 1). A structurally similar compound
Ph3Sn(mimt) contains covalent bond Sn–S as a result of
the presence of thiol form of (mimt)ꢀ (compare
d13C(C2) = 138.7 ppm) [15]. The presence of thione form
in 6 was also corroborated by IR spectroscopy where bands
a
Measured in CDCl3.
SPy, where this polar group is stabilized in its thiol form (i.e.
upfield shift, see Table 1) [18].
The 13C NMR data revealed signal of C2 at 165.2 ppm
for 3 and 161.6 ppm for 4, i.e. very close to those found in
Ph2SnCl-2-SPy, where the polar group exists in the thiol
form (d13C(C2) = 164.2 ppm), and established presence of
covalent bond Sn–S in compounds 3 and 4. The structure
Fig. 1. Proposed structure of 3–6 in solution.
Scheme 2. Proposed formation of 5 and 6.

3418
J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
at 694 cmꢀ1 and 536 cmꢀ1 assignable to r(C@S) and
p(C@S) were found [20]. Since the prepared organotin
compounds analogously exists only as thiolato derivatives
it seems to be reasonable to propose the role of Y,C,Y-che-
lating ligands in a new coordination mode of organotin
compounds. The presence of additional Sn Y coordina-
tion by introducing Y,C,Y-chelating ligand may enable
rearrangement of thiol to thione form (Scheme 2).
The structures of 3 and 6 have been determined by X-ray
crystallographic studies (see Figs. 2, 3) and the crystallo-
graphic data are given in Table 3.
atoms in equatorial positions (see Fig. 2). One axial posi-
tion is occupied by the nitrogen donor atom from ligand
L1, while the sulfur atom from polar group 2-SPy is in
the second one (N(1)–Sn(1)–S(1) = 169.4(2)ꢁ). Bond length
˚
Sn(1)–S(1) (2.544(3) A) is comparable to the Rcov(Sn,
˚
S) = 2.469 A and clearly demonstrates the presence of
covalent bond Sn–S in compound 3 [21]. The presence of
thiol form of 2-SPy is also corroborated by bond length
˚
S(1)–C(15) (1.761(11) A) indicating a single bond charac-
˚
ter. The found bond lengths Sn(1)–N(1) (2.634(9) A) and
˚
Sn(1)–N(3) (3.118(15) A) indicate the presence of Sn–N
The shape of the coordination polyhedron of 3 can be
described as a distorted trigonal bipyramid, with carbon
intramolecular interactions in 3.
The shape of the coordination polyhedron of 6 can be
described as a distorted trigonal bipyramid, with carbon
atoms in equatorial positions (see Fig. 3). One axial posi-
tion is occupied by the oxygen donor atom from ligand
L2, while the nitrogen atom from polar group (mimt) is
in the second one (found bonding angle O(1)–Sn(1)–
N(1) = 168.07(8)ꢁ). The found bond length Sn(1)–O(1)
˚
(2.7875(16) A) indicates the presence of medium strong
Sn–O intramolecular interaction in 6. Bond length Sn(1)–
˚
N(1) (2.1518(19) A) is comparable to the Rcov (Sn, N) =
˚
2.154 A and clearly demonstrates the presence of covalent
bond Sn–N in compound 6 [21]. The presence of thione
form of (mimt) is also corroborated by bond length
˚
C(17)–S(1) (1.696(2) A) that is comparable to those found
in organotin cations containing Hmimt in its thione form
˚
[20] and both double bonds C(17)–S(1) (1.696(2) A) and
˚
C(18)–C(19) (1.340(4) A) are well localized in 6. There is
Fig. 2. General view (ORTEP) of a molecule showing 50% probability
no additional interaction between Sn and S as indicated
by interatomic distance Sn(1)–S(1) (3.5989(10) A).
displacement ellipsoids and the atom-numbering scheme for 3. The
hydrogen atoms are omitted for clarity. Selected bond lengths (A) and
˚
˚
angles (ꢁ) for 3: Sn(1)–C(1) 2.174(9), Sn(1)–C(14) 2.130(10), Sn(1)–C(13)
2.145(11), Sn(1)–N(1) 2.634(9), Sn(1)–N(2) 3.311 (9), Sn(1)–S(1) 2.544(3),
S(1)–C(15) 1.761(11), N(3)–Sn(1) 3.118(11), N(1)–Sn(1)–S(1) 169.4(2),
Sn(1)–S(1)–C(15) 97.5(4).
The comparison of
6 with related Ph3Sn(mimt)
˚
˚
(C(17)–S(1) = 1.746(4) A, Sn(1)–N(1) = 2.920(3) A and
˚
Sn(1)–S(1) = 2.437(1) A) also demonstrates the different
coordination mode of the mercapto group (mimt) (see
Table 4).
2.2. Reactivity of 4 towards CuCl and AgNO3
The fact that compounds 3 and 4 contain free nitrogen
atom of polar group 2-SPy led us to the idea of reacting
4 with CuCl and AgNO3 with the aim to using the free
nitrogen donor atom to stabilize monomeric species of
CuCl and AgNO3 on organotin fragment. However, both
reactions resulted in the exchange of polar groups only
and organotin compounds Ph2L2SnCl (7) and
Ph2L2SnNO3 (8) together with Cu-2-SPy and Ag-2-SPy
1
were obtained and characterizes by H, 13C, 119Sn NMR,
IR spectroscopy, and ESI/MS (see Scheme 3, and for crys-
tal structure of 8 see supporting information).
2.3. Mechanism study of polar group transfer
To give closer insight into the polar group transfer, we
have prepared Ph3Sn-2-SPy (9) and Ph2L2Sn-4-SPy (10)
(see Fig. 4). Those together with 4, enable us to study the
stability of Sn–S covalent bond depending on an additional
Fig. 3. General view (ORTEP) of a molecule showing 50% probability
displacement ellipsoids and the atom-numbering scheme for 6. The
hydrogen atoms are omitted for clarity.

J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
3419
Table 3
Crystal data and structure refinement for 3 and 6
3
6
Empirical formula
Crystal system
Space group
C17H29N3SSn
Orthorhombic
Pca21
12.4890(5)
9.4950(11)
17.5370(15)
90.0(8)
90.0(7)
90.0(8)
4
C32H40N2O2SSn
Triclinic
P1
10.256(2)
10.471(2)
14.351(3)
86.78(3)
83.94(3)
87.24(3)
4
˚
a (A)
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
Z
l (mmꢀ1
Dx (Mg mꢀ3
)
1.330
1.361
0.934
1.383
)
Crystal size (mm)
h Range (ꢁ)
No. of reflections measured
No. of unique reflections; Rint
Final Ra [I > 2r(I)]
wR2a (all data)
0.35 · 0.30 · 0.15
1–27.5
13553
4637, 0.1109
0.0739
0.1845
0.3 · 0.25 · 0.20
1–27.5
14411
6106, 0.0278
0.027
0.069
a
2
2
Definitions: R(F) = RiFoj ꢀ i Fci/RjFoj, wR2 = [R(w(Fo ꢀ Fc2)2)/R (w(Fo2)2)]1/2, S = [R (w(Fo ꢀ Fc2)2)/(Nreflns ꢀ Nparams)]1/2
.
three factors: (i) compound 4 contains Sn–O coordination
and a free nitrogen atom in ortho position to Sn–S bond,
(ii) compound 9 contains a nitrogen atom in ortho position
to Sn–S bond, but is void of any Sn–O interaction, and (iii)
compound 10 contains Sn–O interaction, but contains a
nitrogen atom in trans position to Sn–S bond.
Table 4
˚
Selected bond length (A) and angles (ꢁ) of 6 and related compound
Ph3Sn(mimt) [15]
˚
Compound/bond length (A), angle (ꢁ)
6
Ph3Sn(mimt)
Sn(1)–N(1)
Sn(1)–S(1)
C(17)–S(1)
C(18)–C(19)
Sn(1)–O(1)
N(1)–C(17)–S(1)
O(1)–Sn(1)–N(1)
O(1)–Sn(1)–S(1)
2.1518(19)
3.5989(10)
1.696(2)
1.340(4)
2.7875(16)
2.920(3)
2.437(1)
1.746(4)
1.321(9)
–
123.7(4)
–
–
The reaction of CuCl with compounds 4, 9 and 10,
respectively, was monitored by 119Sn NMR spectroscopy.
Thus, the spectra of corresponding equimolar mixtures
which had been kept at room temperature for three hours
are shown in Fig. 5. In the reaction of 4 with CuCl, there
was the only one signal at ꢀ121.6 ppm in 119Sn NMR spec-
trum assigned to Ph2L2SnCl (7) as the only one organotin
product of the reaction (see Fig. 5a). The reaction of 9 with
CuCl showed two signals at ꢀ104.6 ppm and ꢀ44.6 ppm in
3:7 ratio in 119Sn NMR spectrum assigned to starting com-
pound 9 (30%) and Ph3SnCl (70%) (see Fig. 5b). Similarly,
the 119Sn NMR spectrum of reaction of 10 with CuCl
revealed two signals at ꢀ107.9 and ꢀ121.6 ppm in 9:1 ratio
assigned to starting compound 10 (90%) and Ph2L2SnCl (7)
(10%) (see Fig. 5c).
127.34(17)
168.08(7)
118.85(4)
These observations suggest the polar group transfer
proceeds at a different rate in all three reactions A–C.
Addition of CuCl into Sn–S bond is supposed to be the
first step of the reaction followed then by cleavage of
formed intermediate to give detected products of polar
group transfer (see Scheme 4). The stability of proposed
intermediate is the rate-determine step of the reaction.
In the fastest reaction A (100% conversion), the presence
of free N donor atom in cis-position enable presence of
Cu–N interaction that together with Sn–O interaction
can result to polarization of Sn–S and Cu–Cl bond in this
intermediate. This polarization results then in fast cleav-
age of the original bonds together with the formation of
a new Sn–Cl and Cu–S bonds. In the slowest reaction C
(10% conversion), there is no possibility of Cu–N interac-
Scheme 3. Reactivity of compound 4 toward CuCl and AgNO3.
Fig. 4. Schematic drawings of compounds 4, 9 and 10.

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J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
Fig. 5. The 119Sn NMR spectra of reaction mixtures obtained after 3 h; A – reaction of 4 with CuCl, B – reaction of 9 with CuCl, C – reaction of 10 with
CuCl.
Scheme 4. Proposed mechanism of polar group transfer.
tion (the N atom is in para-position towards Sn–S bond)
and similarly there is no Sn–O interaction in reaction B
(70% conversion).
In summary, we have reported on the preparation of
triorganotin compounds containing N,C,N and O,C,O –
ligands and their use for the stabilization of both
thiol-form of pyridine-2-thiolate and thione-form of 1-
methylimidazole-2-thiolate polar group. The polar group
transfer has been demonstrated and its mechanism was
studied.
shifts were calibrated on: 1H-residual peak of CHCl3
(d = 7.25 ppm), 13C-residual peak of CHCl3 (d = 77.23
ppm), 119Sn-external tetramethylstannane (d = 0.00 ppm).
Electrospray mass spectra (ESI/MS) were recorded in posi-
tive mode on an Esquire3000 ion trap analyzer (Bruker
Daltonics) in the range 100–600 m/z and in the negative
mode on the Platform quadrupole analyzer in the range
100–800 m/z. The samples were dissolved in acetonitrile
and analyzed by direct infusion at a flow rate of 1–10 ll/
min. The IR spectra (cmꢀ1) were recorded on Perkin–
Elmer 684 equipment as nujol suspensions or CH3CN solu-
tions. For the carbons atoms assignment of polar groups
see Tables 1 and 2.
3. Experimental
3.1. General methods
3.2. Synthesis of Me2L1Sn-2-SPy (3)
The starting compounds [Me2L1Sn]+[Cl]ꢀ (1), [Ph2L2-
Sn]+[OTf]ꢀ (2), Ph2L2SnCl (7) and Ph3SnSPy (9) were
prepared according to the literature [8,11,14]. Starting 2-
mercaptopyridine, 4-mercaptopyridine, and 2-mercapto-1-
methylimidazole were purchase from Sigma–Aldrich. All
reactions were carried out under argon, using standard
Schlenk techniques. Solvents were dried by standard meth-
ods and distilled prior to use. The reactions with silver salts
A solution of Na(2-SPy) (0.13 g; 0.96 mmol) in 15 ml of
THF was added to the solution of 1 (0.37 g; 0.96 mmol) in
20 ml of THF. The resulting mixture was stirred for 24 h at
the 40 ꢁC. The solvent was evaporated and residue was sus-
pended in 30 ml pentane. After the filtration, filtrate was
evaporated and washed with cold pentane (5 ml) to obtain
3 as yellow powder. Yield: 0.62 g (69%). M.p. 79–84 ꢁC.
Anal. Calc. for Me2L1Sn-2-SPy (MW 450.22): C, 50.69;
H, 6.49. Found: C, 50.91; H, 6.71%. MS: m/z 110, 100%
1
were protected from light. The H, 13C, and 119Sn NMR
spectra were acquired on Bruker Avance500 spectrometer
in CDCl3 (range 300–210 K). Appropriate chemical
1
[2-SPy]ꢀ, m/z 341, 100% [M-2-SPy]+, H NMR (CDCl3)

J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
3421
d (ppm): 0.81 (6H, s, SnCH3), (2J(119Sn, 1H) = 64 Hz), 2.37
(12H, s, NCH3), 3.86 (4H, s, CH2N), 6.97 (1H, bs, Pyridin),
7.26–7.4 (3H, m, Ar–H), 7.48 (2H, bs, 2-SPy), 8.3 (1H, bs,
2-SPy), 13C NMR(CDCl3) d (ppm): 0.9 (SnCH3), 45.1
(NCH3), 77.2 (CH2N), 117.6 (C-SPy), 121.3 (C-SPy),
127.7 (C(3,5)), 128.4 (C(4)), 135.2 (C-SPy), 143.6 (C(1)),
146.3 (C(2,6)), 148.3 (C-SPy), 165.2 (C-SPy), d(119Sn)
ppm = ꢀ95.0.
days at room temperature. The solvent was evaporated
and residue was suspended in 30 ml hexane/CH2Cl2 (2:1).
After the filtration, filtrate was evaporated and washed
with cold pentane (5 ml) to obtain 6 as white solid. Yield:
120.5 mg (59%). M.p. 175–178 ꢁC. Anal. Calc. for
Ph2L2Sn(mimt) (MW 649.47): C, 61.03; H, 6.52. Found:
C, 61.33; H, 6.77% MS: m/z 113, 15% [mimt]ꢀ, m/z 523,
60% [Mꢀmimt]+, m/z 632 [M+H]+, m/z 563, 30%
1
[M+HꢀtBuOH]+, m/z 411, 80% [Mꢀmimtꢀ2butane]+,
3.3. Synthesis of Ph2L2Sn-2-SPy (4)
H NMR (CDCl3) d(ppm): 0.88 (18H, s, OCH3), 3,45
(3H, s, NCH3 (mimt)), 4.53 (4H, s, CH2O), 6.59 (1H, bs,
mimt), 6.63 (1H, bs, mimt), 7.40 (9H, m, Ar–H), 7.78
(4H, m, Ar–H), 13C NMR (CDCl3) d(ppm): 27.4 (OCCH3),
34.8 (NCH3), 65.7 (CH2O), 75.1 (OC(CH3)3), 120.3 (Cꢀ
mimt), 121.5 (Cꢀmimt), 126.4 (C(3,5)), 128.5 (C(30,50)),
A solution of Na(2-Spy) (78.5 mg; 0.7 mmol) in 15 ml of
THF was added to the solution of 2 (473.8 mg; 0.7 mmol)
in 20 ml of THF. The resulting mixture was stirred for 2
days at the room temperature. The solvent was evaporated
and residue was suspended in 30 ml hexane. After the filtra-
tion, filtrate was evaporated and washed with cold pentane
(5 ml) to obtain 4 as yellow powder. Yield: 345.1 mg (74%).
M.p. 78–84 ꢁC. Anal. Calc. for Ph2L2Sn-2-SPy (MW
632,44): C, 62.67; H, 6.22. Found: C, 62.87; H, 6.42%.
1H NMR (CDCl3) d (ppm): 0.99 (18H, s, OCH3), 4.62
(4H, s, CH2O), 6.9 (1H, bs, 2-SPy), 7.40 (9H, m, Ar–H),
7.50 (2H, bs, 2-SPy), 7.73 (4H, m, Ar–H), 8.0 (1H, bs,
2-SPy), 13C NMR(CDCl3) d(ppm): 27.8 (OCH3), 66.4
(CH2O), 73.9 (OC(CH3)3), 118.7 (C-SPy), 124.1 (C-SPy),
125.9 (C(4)) 128.4 (C(3,5)), 128.5 (C(40)), 128.9 (C(30,50)),
129.6 (C-SPy), 136.4 (C(20,60)), 136.8 (C(1)), (1J(119Sn;
13C) = 692 Hz), 144.8 (C(10)), 147.1 (C(2,6)), 147.7
(C-SPy), 161.6 (C-SPy), d(119Sn) ppm = ꢀ141.9.
13
(nJ(119Sn; C) = 45,37 Hz), 129.5 (C(4)), 129.6 (C(40)),
13
135.9 (C(1)), (1J(119Sn; C) = 713 Hz), 137.2 (C(20,60)),
141,2 (C(10)), (1J(119Sn; 13C) = 715 Hz), 147.3 (C(2,6)),
163.5 (SCN2), d (119Sn) ppm = ꢀ173.5.
3.6. Synthesis of Ph2L2Sn-4-SPy (10)
The NaOH (0.184 g; 4.6 mmol) was added to the solu-
tion of 4-mercaptopyridine (H-4-Spy, 511 mg; 4.6 mmol)
dissolved in the 10 ml of H2O and then TlNO3 (1.22 g;
4.6 mmol) was added to the same of solution after 30 min
stirring. The resulting mixture was stirred for 1 h at room
temperature and after the filtration the insoluble fraction
was dried to obtain Tl(4-SPy) as yellow powder. Yield:
38 mg (95%). A Tl(4-SPy) (34 mg; 0.1 mmol) was added
to the solution of 7 (58 mg; 0.1 mmol) in the 20 ml of
CH2Cl2. The resulting mixture was stirred for 1 week at
room temperature. After the filtration, the solvent was
evaporated and washed with cold pentane (5 ml) to obtain
10 as yellow solid. Yield: 56 mg (90%). M.p. 83–88 ꢁC.
Anal. Calc. for Ph2L2Sn-4-SPy (MW 632,44): C, 62.67;
H, 6.22. Found: C, 62.87; H, 6.42%. MS: m/z 110, 65%
[4ꢀSPy]ꢀ, m/z 523, 60% [Mꢀ4ꢀSPy]+, m/z 467, 50%
[Mꢀ4ꢀSPyꢀbuten]+, m/z 411, 62% [Mꢀ4ꢀSPyꢀ2buten]+;
3.4. Synthesis of Me2L1Sn(mimt) (5)
A solution of Na(mimt) (34 mg; 0.3 mmol) in 15 ml of
THF was added to the solution of 1 (0.105 g; 0.302 mmol)
in 20 ml of THF. The resulting mixture was stirred for 24 h
at the 40 ꢁC. The solvent was evaporated and residue was
suspended in 40 ml of pentane/CH2Cl2 (3:1). After the fil-
tration, filtrate was evaporated and washed with cold pen-
tane (5 ml) to obtain 5 as white solid. Yield: 94.5 mg (70%).
M.p. 179–185 ꢁC. Anal. Calc. for Me2L1Sn(mimt) (MW
467.25): C, 47.70; H, 6.67. Found: C, 47.90; H, 6.87%.
MS: m/z 113, 70% [mimt]ꢀ, m/z 225, 100% [2mimtꢀH]ꢀ,
1
m/z 634, 3% [M+H]+, H NMR (CDCl3) d (ppm): 0.88
(18H, s, OCH3), 4.55 (4H, s, CH2O), 7.00 (2H, bs,
4-SPy), 7.31 (9H, m, Ar–H), 7.55 (4H, m, Ar–H), 8.01
(2H, bs, 4-SPy), 13C NMR (CDCl3) d(ppm): 27.5
(OCCH3), 66.2 (CH2O), (nJ(119Sn, 13C) = 31.3 Hz), 75.1
(OC(CH3)3), 126.7 (C(1)), (1J(119Sn; 13C) = 699 Hz), 127.2
(C(3,5)), 128.7 (C(30,50)), 129.3 (C(40)), 130.0 (C, 4ꢀSPy),
130.1 (C(4)), 134.6 (C(10)), (1J(119Sn; 13C) = 700 Hz),
136.1 (C(20,60)), 141.7 (C(2,6)), 148.2 (C, 4ꢀSPy), 148.6
(C, 4ꢀSPy). d (119Sn) ppm = ꢀ107.9.
1
m/z 341, 100% [Mꢀmimt]+, H NMR (CDCl3) d(ppm):
1
0.65 (6H, s, SnCH3), (2J(119Sn, H) = 63 Hz), 2.02 (12H,
s, NCH3), 3.50 (3H, s, CH3N (mimt)), 3.57 (4H,
s, CH2N), 6.58 (1H, bs, mimt), 6.67 (1H, bs, mimt),
7.05–7.21 (3H, m, Ar–H), 13C NMR (CDCl3) d(ppm):
ꢀ1.1 (SnCH3), 34.2 (CH3 Im), 45.2 (NCH3), 65.3
(CH2N), 118.9 (Cꢀmimt), 128.0 (C(3,5)), 128.7 (C(4)),
142.4 (C(1)), 146.0 (C(2.6)), 162.9 (SCN2), d (119Sn)
ppm = ꢀ124.0.
3.7. Reaction of 4 with CuCl
3.5. Synthesis of Ph2L2Sn(mimt) (6)
The CuCl (10 mg; 0,1 mmol) was added to the solution
of 4 (70 mg; 0.1 mmol) in the 20 ml of THF. The resulting
mixture was stirred 10 h at room temperature. The solvent
was evaporated, and residue was suspended in 10 mL of
CH2Cl2/pentane (1:1). After the filtration, filtrate was
A solution of Na(mimt) (41.8 mg; 0.3 mmol) in 15 ml of
THF was added to the solution of 2 (205.9 mg; 0.3 mmol)
in 20 ml of THF. The resulting mixture was stirred for 2

3422
J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
1
evaporated and the residue was characterized by H and
119Sn NMR spectroscopy as 7 according to the literature
data [11]. The insoluble precipitate was characterized by
1H NMR and IR spectroscopy as CuSPy in accordance
to data found in the literature [22].
inserted in calculated positions and isotropically refined
assuming a ‘‘ride-on’’ model.
Acknowledgements
The authors thank Robert Jirasko, University of Par-
dubice, for recording the Elecrospray Ionizaiton Mass
spectra and the Grant Agency of the Czech Republic (Pro-
ject No. 203/07/0468) and The Ministry of Education of
the Czech Republic (Projects Nos. VZ0021627502 and
LC523) for financial support.
3.8. Reaction of 4 with AgNO3
A 15 ml acetone solution of 4 (70 mg; 0.1 mmol) was
slowly added to the AgNO3 (19 mg; 0.1 mmol) dissolved
in the 20 ml of H2O. On the interface of both phases, crys-
tals suitable for X-ray diffraction study were grown within
four days. The solution was decanted and crystalline mate-
rial was characterized by 1H, 13C and 119Sn NMR spectros-
copy, ESIMS and elemental analysis as compound 8.
Structure was detected by X-ray diffraction (see Supporting
information). Yield: 48 mg (75%). M.p. 140–145 ꢁC. Anal.
Calc. for Ph2L2SnNO3 (MW 584,28): C, 57.56; H, 6.04.
Found: C, 5.76; H, 5.85%. MS: m/z 523, 60% [M–NO3]+,
1H NMR (CDCl3) d(ppm): 0.87 (18H, s, OCH3), 4.62
(4H, s, CH2O), 7.43 (9H, m, Ar–H), 7.79 (4H, m, Ar–H),
13C NMR (CDCl3) d(ppm): 27.4 (OC(CH3)3), 65.5
(CH2O), 77.2 (OC(CH3)3), 127.5 (C(3,5)), 129.0 (C(30,50)),
130.2 (C(4)), 130.3 (C(40)), 136.9 (C(20,60)), 142.2 (C(2,6)),
d(119Sn) ppm = ꢀ80.3. The evaporation of solvent, the res-
Appendix A. Supplementary material
CCDC 632632 and 610595 contain the supplementary
crystallographic data for 3 and 6. These data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/
conts/retrieving.html, or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK; fax: (+44) 1223-336-033; or e-mail: depos-
it@ccdc.cam.ac.uk. Supplementary data associated with
this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2007.04.006.
1
References
idue was characterized by IR and H NMR spectroscopy
as Ag-2-SPy in accordance to data found in the literature
[23].
[1] (a) A.G. Davies, Organotin Chemistry, VCH, Weinhein, 1997;
(b) P. Smith, Chemistry of Tin, Blackie Academic & Professional an
imprint of Thompson Science, London, 1998;
3.9. Crystallography studies
(c) W.T. Piver, Environ. Health Perspect. 4 (1973) 61;
(d) G.J.M. van de Klerk, J. Zuckerman (Eds.), Organotin
Compounds, American Chemical Society, Washington, DC, 1976,
p. 1;
(e) P. Yang, M. Guo, Coord. Chem. Rev. 185–186 (1999) 189;
(f) M. Gielen, Coord. Chem. Rev. 151 (1996) 41;
(g) M. Gielen, M. Biesemans, R. Willem, Appl. Organomet.
Chem. 19 (2005) 440;
Colorless crystals were obtained from toluene solutions
at ꢀ5 ꢁC solutions of 3 and 6. The intensity data for
single crystal of 3 were measured on four-circle diffrac-
tometer KappaCCD with CCD area detector by mono-
˚
chromatized Mo Ka radiation (k = 0.71073 A) at 150(2)
(h) M. Gielen, J. Braz. Chem. Soc. 14 (2003) 870;
(i) M. Gielen, M. Biesemans, R. Willem, E.R. T Tiekink, Eur. J.
Inorg. Chem. 3 (2004) 445;
K. The crystallographic details are summarized in Table
1, and empirical absorption corrections were applied
(multiscan from symmetry-related measurements). The
structure was solved by the direct methods (SIR97) and
refined by a full-matrix least-squares procedure based on
F2 (SHELXL 97). Hydrogen atoms were mostly localized
(j) M. Gielen, Appl. Organomet. Chem. 16 (2002) 481.
[2] (a) C.J. Evans, S. Karpel, Organotin Compounds in Modern
Technology, Elsevier, Amsterdam, 1985, p. 23;
(b) C.J. Evans, Spect. Chem. 11 (1991) 152.
[3] (a) C.V. Rodarte de Moura, A.P.G. Sousa, R.M. Silva, A. Abras, M.
Horner, A.J. Bortoluzzi, C.A.L. Filgueiras, J.L. Wardell, Polyhedron
18 (1999) 2961, and reference therein;
on
a difference Fourier map, however to ensure
uniformity of treatment of crystal, all hydrogen were
recalculated into idealized positions (riding model) and
assigned temperature factors Hiso(H) = 1.2 Ueq (pivot
atom) or of 1.5 Ueq for the methyl moiety. In the case
ofꢀ33, the main residual electron density maximum ꢁ1 e
´
´
(b) M.V. Castano, A. Macıas, A. Castineiras, A.S. Gonzales, E.G.
´
Martınez, J.S. Casas, J. Sordo, J. Chem. Soc., Dalton Trans. 1001
(1990).
[4] (a) M.N. Xanthopoulou, S.K. Hadjikakou, N. Hadjiliadis, M. Schur-
mann, K. Jurkschat, A. Michaelides, S. Skoulika, T. Bakas, J. Binolis,
S. Karkabounas, K. Charalabopoulos, J. Inorg. Biochem. 96 (2003)
425;
˚
˚
is located about 1 A from tin atom which is probably
A
caused by presence of two lone electron pairs originated
from nitrogen atoms. The intensity data for 6 were col-
lected on a KUMA KM-4 CCD kappa-axis diffractometer
using a graphite monochromatized Mo Ka radiation
(b) M.D. Couce, G. Faraglia, U. Russo, L. Sindellari, G. Valle, J.
Organomet. Chem. 513 (1996) 77;
´
´ ´
(c) J. Susperregui, M. Bayle, J.M. Leger, G. Deleris, J. Organomet.
Chem. 556 (1998) 105;
˚
(k = 0.71073 A) at 260(2) K. The structure was solved
´
´
(d) A.S. Gonzales, E.G. Martınez, J.S. Casas, J. Sordo, U. Casellato, R.
Graziani, U. Russo, J. Organomet. Chem. 463 (1993) 91.
[5] J. Susperregui, M. Bayle, J.M. Leger, G. Deleris, J. Organomet.
Chem. 556 (1998) 105.
by direct methods (Sheldrick G.M. SHELX-97 [24]), (Sheld-
rick G.M.: SHELXTL V 5.1 [25]). Non-hydrogen atoms were
refined anisotropically while hydrogen atoms were

J. Martincova´ et al. / Journal of Organometallic Chemistry 692 (2007) 3415–3423
3423
´
´
[6] (a) N.L. Speziali, B.G. Guimaraes, R.M. Silva, P.H. Duarte, S.R.
Aguiar, Acta. Crystallogr., Sect. C 50 (1994) 1059;
(b) G.D. Andreeti, G. Bocelli, G. Calestani, P. Sgarabotti, J.
Organomet. Chem. 273 (1984) 31.
[15] J.S. Casas, A. Castineiras, E.G. Martinez, A.S. Gonzales, A. Sanchez,
J. Sordo, Polyhedron 16 (1997) 795.
[16] (a) A. Lycˇka, J. Holecˇek, B. Schneider, J. Straka, J. Organomet.
Chem. 389 (1990) 29;
[7] (a) N.G. Furmanova, Yu. T. Struchkov, E.M. Rokhlina, D.N.
Kravtsov, J. Struct. Chem. Engl. Trans. 21 (1980) 766;
(b) N.G. Furmanova, Yu. T. Struchkov, E.M. Rokhlina, D.N.
Kravtsov, J. Struct. Chem. Engl. Trans. 22 (1981) 569;
(c) L. Petrilli, F. Caruso, E. Rivarola, Main Group Met. Chem. 17
(1994) 293;
(b) T.P. Lockhart, W.F. Manders, Inorg. Chem. 25 (1986) 892.
´
´
[17] M.V. Castano, A. Macıs, A. Castineiras, A.S. Gonzales, E.G.
˜
˜
´
Martınez, J.S. Casas, J. Sordo, W. Hiller, E.E. Castellano, J. Chem.
Soc., Dalton Trans. (1990) 1001.
[18] R. Schmiedgen, F. Huber, H. Preut, G. Ruisi, R. Barbieri, Appl.
Organomet. Chem. 8 (1994) 397.
´
(d) J. Bravo, M.B. Cordero, J.S. Casas, A. Sanchez, J. Sordo, E.Z.
Castellano, J. Zuckerman-Schpector, J. Organomet. Chem. 482
(1994) 147;
(e) N.G. Bokii, D.N. Kravtsov, E.M. Rokhlina, J. Struct. Chem.,
Eng. Trans. 14 (1973) 258;
[19] (a) J. Bravo, M.B. Cordero, J.S. Casas, A. Sanchez, J. Sordo, E.E.
Castellano, S. Zukermann, J. Organomet. Chem. 482 (1994) 147;
(b) E. Buncel, A.R. Norris, S.E. Taylor, W.J. Racz, Can. J. Chem. 60
(1982) 3033.
´
´
[20] (a) E.G. Martınez, A.S. Gonzales, J.S. Casas, J. Sordo, U. Casellato,
(f) R. Cea-Olivares, O. Jimenez-Sandoval, G. Espinosa-Perez, C.
Silvestru, J. Organomet. Chem. 484 (1994) 33.
R. Graziani, Inorg. Chim. Acta 191 (1992) 75;
´
´
(b) J.S. Casas, E.G. Martınez, A.S. Gonzales, J. Sordo, U. Casellato,
R. Graziani, U. Russo, J. Organomet. Chem. 493 (1995) 107;
(c) J.S. Casas, A. Castineiras, E.G. Martinez, A.S. Gonza´les, J.
Sordo, E.M.V. Lopez, Polyhedron 15 (1996) 891.
[21] Y.I. Baukov, S.N. Tandura, Z. Rappopport (Eds.), The Chemistry of
Organic Germanium, Tin and Lead Compounds, Wiley, Chichester,
2002.
´
´
´
˚
ˇ
ˇ
´
[8] (a) B. Kasˇna, R. Jambor, L. Dostal, A. Ruzˇicka, I. Cısarova, J.
Holecˇek, Organometallics 23 (2004) 5300;
´
´
´
´ˇ
´
ˇ
´
(b) B. Kasˇna, R. Jambor, L. Dostal, L. Kolarova, I. Cısarova, J.
Holecˇek, Organometallics 25 (2006) 148.
´
´
[9] J. Martincova, L. Dostal, J. Taraba, R. Jambor, J. Organomet.
Chem. 692 (2007) 908.
´
´
´
´ˇ
´
ˇ
´
[10] B. Kasˇna, R. Jambor, L. Dostal, L. Kolarova, I. Cısarova, J.
[22] S. Kitagawa, M. Munakata, H. Shimono, S. Matsuyama, H. Masuda,
J. Chem. Soc., Dalton. Trans. (1990) 2105.
Holecˇek, Organometallics 25 (2006) 148.
´
´
˚
ˇ
ˇ
´
ˇ
[11] R. Jambor, L. Dostal, A. Ruzˇicka, I. Cısarova, J. Brus, M. Holcapek,
[23] (a) M. Hong, W. Su, R. Cao, W. Zhang, J. Lu, Inorg. Chem. 38
(1999) 600;
J. Holecˇek, Organometallics 21 (2002) 3996.
´
´
´
ˇ
ˇ
[12] J. Holecˇek, M. Nadvornık, K. Handlır, A. Lycka, J. Organomet.
(b) W. Su, M. Hong, J. Weng, Y. Liang, Y. Zhao, R. Cao, Z. Zhou,
A.S.C. Chan, Inorg. Chim. Acta 331 (2002) 8.
Chem. 241 (1983) 177.
[13] M. Bouaˆlam, J. Meunier-Piret, M. Biesemans, R. Willem, M. Gielen,
Inorg. Chim. Acta 198 (1992) 249.
[24] G.M. Sheldrick, SHELX-97 Program Package, University of Go¨ttingen,
1997.
[14] R.J. Deeth, K.C. Molloy, M.H. Mahon, S. Whittaker, J. Organomet.
Chem. 430 (1992) 25.
[25] G.M. Sheldrick, SHELXTL V 5.10, Bruker AXS Inc., Madison, WI,
1997.