New organotin carboxylates derived from 6-chloro-3-pyridineacetic acid exhibiting discrete molecular, drum-like, linear polymeric and ladder structures constructed from dimeric tetraorganodistannoxane units

Article abstract of DOI:10.1016/j.poly.2010.11.035

Seven new organotin (IV) carboxylates have been synthesized by the reactions of 6-chloro-3-pyridineacetic acid with triorganotin chloride and diorganotin dichloride. All the complexes were characterized by elemental analysis, IR, ¹H NMR, ¹

Full text of DOI:10.1016/j.poly.2010.11.035

Polyhedron 30 (2011) 624–631
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Polyhedron
journal homepage: www.elsevier.com/locate/poly
New organotin carboxylates derived from 6-chloro-3-pyridineacetic acid
exhibiting discrete molecular, drum-like, linear polymeric and ladder
structures constructed from dimeric tetraorganodistannoxane units
Jun-Hong Zhang a,c, Ru-Fen Zhang a, , Chun-Lin Ma a,b, Da-Qi Wang a, Hai-Zeng Wang c
⇑
a Department of Chemistry, Liaocheng University, Liaocheng 252059, PR China
b Taishan University, Taian 271021, PR China
c College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, Shandong, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 12 July 2010
Accepted 25 November 2010
Available online 5 December 2010
Seven new organotin (IV) carboxylates have been synthesized by the reactions of 6-chloro-3-pyridineace-
tic acid with triorganotin chloride and diorganotin dichloride. All the complexes were characterized by
elemental analysis, IR, 1H NMR, 13C NMR, 119Sn NMR and X-ray crystallography. The structural analyses
show that all the complexes present various structures, including monomer, drum, 1D polymers and lad-
ders. It is worth noting that complex 1 is a novel 1D spring-like helical chain containing guest solvent
molecules.
Keywords:
Organotin
Helical chain
Ladders
Ó 2010 Elsevier Ltd. All rights reserved.
Drum
1. Introduction
2. Results and discussion
It is well known that organotin carboxylates have versatile
molecular structures, both in the solid state and in solution, such
as monomers, dimers, tetramers, oligomeric ladders and hexa-
meric drums, etc. [1–4]. It has also been demonstrated that other
structural types are formed due to the presence of additional
heteroatom sites (S, N or O, etc.) along with a carboxylate moiety
[5–10]. In our previous work, we have reported some new
organotin complexes, including a macrocycle containing five tin
nuclei with heterocyclic sulfur and nitrogen donor ligands and
macrocyclic complexes containing 3 and 18 tin nuclei with 2-
mercaptonicotinic [11,12], as well as a novel 2D network polymer
containing a 60-membered organotin macrocycle [13]. To continue
our research on organotin (IV) complexes in this field, we chose
another carboxylic acid ligand, 6-chloro-3-pyridineacetic acid,
and obtained seven new organotin carboxylates by the use of this
ligand with triorganotin chloride and diorganotin dichloride. These
complexes have been characterized by elemental analysis, IR, 1H,
13C and 119Sn NMR spectroscopy and X-ray crystallography. In this
article, we report the synthesis, characterization and crystal
structures of these organotin carboxylates.
2.1. Spectra of complexes 1–7
The main feature in the IR spectra of complexes 1–7 is the
absence of bands in the region 3170–2990 cmÀ1, which appear in
the free ligand as CO2H stretching vibrations, thus indicating
metal–ligand bonding through these sites. The typical absorptions
for Sn-C, Sn-O vibrations in all the complexes are located in the
normal range of similar organotin complexes [14,15].
The 1H NMR spectra shows the signals of the ACO2H proton,
present in the spectrum of the ligand, are absent in all the
complexes, indicating the removal of the ACO2H proton and the
formation of Sn-O bonds. According to the literature [16], signals
for complexes 1–2 and 4–6 in the 119Sn NMR spectra indicate the
same coordination environments in the solid state and in solution;
while for complexes 3 and 7, the 119Sn NMR spectroscopic data
(d = 48.2 and À18.3 ppm, respectively) show signals in the range
of four-coordinated tin complexes, so it can reasonably be assumed
that the environments around the tin atoms in complexes 3 and 7
are different in the solid state and in solution.
2.2. Crystal structures of complexes 1–7
2.2.1. {(Ph3Sn)[(COO)(CH2C5H3NCl)]}n (1)
⇑
Selected bond lengths and bond angles of complex 1 are shown
in Table 1, the repeating unit, 1D chain structure and perspective
Corresponding author. Tel.: +86 635 8238121; fax: +86 538 6715521.
E-mail address: yver123@163.com (R.-F. Zhang).
0277-5387/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2010.11.035

J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
625
Table 1
shown in Fig. 4. Similar to complex 1, the carboxylic acid adopts
a bidentate mode and coordinates to the tin atoms. The geometry
of the tin center is a distorted trigonal bipyramid, and the center
tin atom is five-coordinated with the two oxygen atoms occupying
the axial sites; the O–Sn–O axial angles are O(2)–Sn(1)–O(4)#1
175.3(6)° and O(3)–Sn(2)–O(1) 173.9(6)°. Three Sn-methyl groups
define the equatorial plane, and the sum of the trigonal C–Sn–C an-
gles are 359.1° and 358.7°, which illustrates that the three methyl
groups and tin atoms are nearly coplanar. As shown in Fig. 4, each
deprotonated 6-chloro-3-pyridineacetic acid acts as a bidentate li-
gand, connecting two adjacent tin atoms and giving rise to an infi-
nite zigzag chain, which is different from complex 1 and consistent
with that found in our previous work [27].
Selected bond lengths (Å) and angles (°) for complex 1.
Sn(1)–O(1A)
Sn(2)–O(1B)
Sn(3)–O(1C)
Sn(4)–O(1D)
Sn(5)–O(1E)
Sn(6)–O(2G)
Sn(7)–O(2H)
Sn(8)–O(2I)
2.23(3)
2.29(3)
2.22(3)
2.26(3)
2.24(3)
2.28(4)
2.18(4)
2.19(4)
Sn(1)–O(2B)
Sn(2)–O(2C)
Sn(3)–O(2D)
Sn(4)–O(2E)
Sn(5)–O(2F)
Sn(6)–O(1F)
Sn(7)–O(1G)
Sn(8)–O(1H)
2.24(3)
2.30(3)
2.25(3)
2.28(4)
2.31(3)
2.32(4)
2.27(4)
2.22(5)
Sn(9)–O(1I)
Sn(10)–O(1J)
2.23(3)
2.22(3)
Sn(9)–O(2J)
2.26(3)
2.28(3)
Sn(10)–O(2A)#1
O(1B)–Sn(2)–O(2C)
O(1D)–Sn(4)–O(2E)
O(2G)–Sn(6)–O(1F)
O(2I)–Sn(8)–O(1H)
O(1J)–Sn(10)–O(2A)#1
O(1A)–Sn(1)–O(2B)
O(1C)–Sn(3)–O(2D)
O(1E)–Sn(5)–O(2F)
O(2H)–Sn(7)–O(1G)
O(1I)–Sn(9)–O(2J)
177.2(10)
176.2(12)
173.8(15)
178.4(17)
175.2(13)
175.6(11)
178.7(12)
179.3(15)
177.1(14)
174.2(11)
2.2.3. {(PhCH2)3Sn)[(COO)(CH2C5H3NCl)]}ÁH2O (3)
Symmetry code for complex 1: #1 x À 1, y, z.
Selected bond lengths and bond angles for complex 3 are given
in Table 3, and the molecular structure of complex 3 is shown in
Fig. 5. Complex 3 is a monomer, which is different from complexes
1 and 2, and the carboxy group adopts a monodentate mode of
coordination to the tin atom in complex 3, whereas a bidentate
mode is adopted in complexes 1 and 2. The central tin atom of
complex 3 is five-coordinated with a distorted trigonal bipyrami-
dal geometry, the carboxylic oxygen atom and an additional water
molecule occupying the axial sites, and the axial angle O(1)–Sn(1)–
O(3) is 172.37(10)°. The primary bond lengths in complex 3 are:
Sn(1)–O(1) 2.141(3) Å and Sn(1)–O(3) 2.430(3) Å. All the Sn–O
bonds are comparable with those found in other similar organotin
complexes [28].
view along a axis of 1 are shown in Figs. 1–3, respectively. By
searching the CSD, we found that although some 1D chain organo-
tin structures have been reported [17–20], such novel 1D spring-
like helical chains are rare. The crystal structure of complex 1 is
constructed from
a 1D helical chain consisting of [(Ph3Sn)
(C7H5ClNO2)] entities, Fig. 1 shows a perspective view of the
[(Ph3Sn)(C7H5ClNO2)] entity. In complex 1, all the tin atoms pos-
sess the same coordination environment. The coordination about
the tin atom is only slightly distorted from a regular trigonal bipy-
ramidal geometry. As the result of the bidentdate mode of coordi-
nation about the carboxylic acid, each tin center is five-coordinated
and exists in a trigonal bipyramidal geometry with the coordinated
oxygen atoms occupying the axial sites, the Sn-O distances
[2.18(3)–2.32(4) Å] are similar to those reported in other organotin
complexes [21,22], and approach the sum of the covalent radii of
tin and oxygen [23], which prove the oxygen atoms are coordi-
nated to the tin atoms by strong chemical bonds. The O–Sn–O an-
gles [173.8(15)–179.3(15)°] are close to linear arrangements. The
Sn–C bond lengths [2.02(6)–2.23(5) Å] are consistent with those
reported in other triorganotin carboxylates [24–26]. The repeating
[(Ph3Sn)(C7H5ClNO2)] units are linked by intermolecular Sn–O
bonds, thus giving a 1D spring-like helical chain with a columnar
channel. It is worth mentioning here that the solvent benzene mol-
ecules are captured in this channel (Figs. 2 and 3), and one benzene
molecule is included per 10 monomer units.
2.2.4. [PhSn(O)(COO)(CH2C5H3NCl)]6 (4)
Selected bond lengths and bond angles for complex 4 are given
in Table 4, and the molecular structure of complex 4 is shown in
Fig. 6. Complex 4 has a typical drum structure. Although we used
diphenyltin dichloride as a raw material, in the reaction process
one phenyl group was lost and a stable drum structure was formed
because of hydrolysis. The centrosymmetric structure is built
around a Sn6O6 central stannoxane core which contains two puck-
ered six-membered [Sn3(l3–O)3] rings as its top and bottom faces.
The two [Sn3( 3–O)3] rings are connected further by six Sn–O
l
bonds, provided by tri-coordinated O atoms. Thus the side face of
the drum is characterized by six puckered four-membered
[Sn2(l3–O)2] rings. Alternate tin atoms are held together by the
coordination action of bidentate carboxylate groups to form a sym-
metrical bridge between two carboxylate ligands. This represents
the signature structural feature of stannoxane clusters. In general,
the Sn–O bond lengths inside the core range between 2.08 and
2.14 Å, and these distances are comparatively shorter than the
Sn–O bonds to the bridging carboxylate ligands (2.16 (3)–
2.21(6) Å) [29]. The Sn–O–Sn bond angles in the six-membered
rings, in the ranges 99.4(5)–135.0(6)°, are wider than those found
2.2.2. {(Me3Sn)[(COO)(CH2C5H3NCl)]}n (2)
Selected bond lengths and bond angles for complex 2 are given
in Table 2, and the 1D polymeric chain structure of complex 2 is
in the four-membered rings. The four-membered [Sn2(l3–O)2]
rings are not planar, the oxygen atoms being tilted toward the cav-
ity of the drum. Thus the interior of the drum can be considered as
a crown made of six oxygen atoms in a trigonal antiprismatic
arrangement, and this was approved by the Sn–O bond lengths.
The oxygen atoms from the bridging carboxylate ligands occupy
two of the coordination sites, and the sixth coordination site is
occupied by a carbon atom from the phenyl group, such that the
O5C donor set defines a distorted octahedron. In complex 4, the dis-
tance between the planes defined by the six tin atoms is about
2.3 Å, so we can image a center residing in the interior of the cavity.
The center is defined by a crown of six oxygen atoms in a trigonal-
antiprismatic arrangement, where the average O–O distance is
2.63 Å and the average distance from the center of the cavity to
the O atoms is 2.12 Å. On the basis of a van der Waals radius of
1.40 Å for oxygen, the interior of the cavity could thus host a spe-
Fig. 1. The repeating unit of complex 1.

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J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
Fig. 2. The 1D spring-like helical chain structure of complex 1 (the phenyl groups are omitted for clarity).
Fig. 3. Perspective view along the a axis of complex 1, from this angle of view we can distinctly see the benzene molecules which are captured by the columnar channel of 1.
cies with a radius of approximate 0.70 Å. The entrance to the cavity
is defined by three oxygen atoms arranged as an approximate equi-
lateral triangle with an average edge length (oxygen center to oxy-
gen center) of 3.27 Å. Again with 1.40 Å as the van der Waals radius
of oxygen, species with radii up to about 0.50 Å could gain entrance
to the cavity.
Table 2
Selected bond lengths (Å) and angles (°) for complex 2.
Sn(1)–C(16)
Sn(1)–C(15)
Sn(1)–O(4)#1
Sn(2)–C(18)
2.06(2)
2.15(3)
Sn(1)–C(17)
Sn(1)–O(2)
Sn(2)–C(19)
Sn(2)–C(20)
2.105(16)
2.191(17)
2.107(17)
2.131(18)
2.368(12)
116.7(10)
93.2(8)
90.7(10)
87.0(6)
175.3(6)
124.6(8)
93.9(8)
2.370(11)
2.12(3)
2.167(19)
125.2(9)
117.2(11)
95.7(6)
88.4(7)
84.6(9)
117.4(10)
116.7(9)
91.0(9)
Sn(2)–O(3)
Sn(2)–O(1)
C(16)–Sn(1)–C(17)
C(17)–Sn(1)–C(15)
C(17)–Sn(1)–O(2)
C(16)–Sn(1)–O(4)#1
C(15)–Sn(1)–O(4)#1
C(19)–Sn(2)–C(18)
C(18)–Sn(2)–C(20)
C(18)–Sn(2)–O(3)
C(19)–Sn(2)–O(1)
C(20)–Sn(2)–O(1)
C(16)–Sn(1)–C(15)
C(16)–Sn(1)–O(2)
C(15)–Sn(1)–O(2)
C(17)–Sn(1)–O(4)#1
O(2)–Sn(1)–O(4)#1
C(19)–Sn(2)–C(20)
C(19)–Sn(2)–O(3)
C(20)–Sn(2)–O(3)
C(18)–Sn(2)–O(1)
O(3)–Sn(2)–O(1)
2.2.5. {(Bu2Sn)2(O)[(COO)(CH2C5H3NCl)]2} (5),
{(Me2Sn)2(O)[(COO)(CH2C5H3NCl)]2}n (6) and {[(PhCH2)2Sn)]2
[(O)(COO)(CH2C5H3NCl)]}Á2CH3OH (7)
Selected bond lengths and bond angles for complexes 5–7 are
given in Table 5; the molecular structures of complexes 5 and 7
are shown in Figs. 7 and 9, respectively; while the 1D chain struc-
ture of complex 6 is shown in Fig. 8. In complexes 5–7 the hydro-
lysis occurred because of the presence of water molecules in the
benzene solvent. Complexes 5–7 are all typical organotin ladders
96.0(8)
83.2(8)
173.9(6)
87.0(7)
88.4(7)
Symmetry code for complex 2: #1 x + 1, y À 1, z.

J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
627
Fig. 4. The 1D infinite zigzag chain structure of complex 2.
Table 3
Table 4
Selected bond lengths (Å) and angles (°) for complex 3.
Selected bond lengths (Å) and angles (°) for complex 4.
Sn(1)–C(22)
Sn(1)–O(1)
Sn(1)–O(3)
C(22)–Sn(1)–O(1)
Sn(2)–O(3)
C(22)–Sn(1)–C(8)
O(1)–Sn(1)–C(8)
C(15)–Sn(1)–O(3)
2.133(4)
2.141(3)
2.430(3)
91.75(14)
2.167(19)
120.49(19)
100.69(14)
85.16(14)
Sn(1)–C(15)
Sn(1)–C(8)
2.138(4)
2.146(4)
Sn(1)–O(1)
Sn(1)–O(2)
Sn(1)–Sn(2)
Sn(2)–O(3)
Sn(2)–O(7)
Sn(3)–O(3)
Sn(3)–O(1)
O(1)–Sn(1)–O(3)#1
O(3)#1–Sn(1)–O(2)
O(2)–Sn(1)–O(10)#1
O(2)–Sn(1)–O(5)
O(2)–Sn(2)–O(1)
O(2)–Sn(2)–O(7)
O(1)–Sn(2)–O(7)
O(3)–Sn(2)–O(6)
O(3)–Sn(3)–O(8)
O(3)–Sn(3)–O(9)
2.118(12)
2.124(12)
3.2461(17)
2.121(12)
2.192(15)
2.126(12)
2.139(11)
107.0(5)
79.0(5)
87.4(5)
88.3(5)
78.4(5)
161.3(5)
87.6(5)
Sn(1)–O(3)#1
Sn(1)–O(5)
Sn(2)–O(2)
Sn(2)–O(1)
Sn(2)–O(6)
2.120(13)
2.211(13)
2.113(13)
2.123(12)
2.199(13)
2.131(12)
2.184(15)
78.3(5)
157.1(5)
84.6(5)
103.5(5)
78.3(5)
C(22)–Sn(1)–C(15)
C(15)–Sn(1)–O(1)
Sn(2)–O(1)
C(15)–Sn(1)–C(8)
C(22)–Sn(1)–O(3)
O(1)–Sn(1)–O(3)
119.39(18)
94.22(14)
2.368(12)
117.36(16)
81.98(13)
172.37(10)
Sn(3)–O(2)#1
Sn(3)–O(8)
O(1)–Sn(1)–O(2)
O(1)–Sn(1)–O(10)#1
O(1)–Sn(1)–O(5)
O(2)–Sn(2)–O(3)
O(3)–Sn(2)–O(1)
O(3)–Sn(2)–O(7)
O(2)–Sn(2)–O(6)
O(1)–Sn(2)–O(6)
O(1)–Sn(3)–O(8)
O(1)–Sn(3)–O(9)
Symmetry code for complex 3: #1 x + 1, y À 1, z.
85.4(5)
89.6(5)
83.9(5)
86.9(5)
155.1(5)
86.4(5)
88.8(5)
161.8(5)
Symmetry code for complex 4: #1 Àx + 2, Ày + 1, Àz + 1.
Fig. 5. The molecular structure of complex 3.
made up of dimeric tetraorganodistannoxane and bridging carbox-
ylate units, but they are not completely the same.
The structure of complex 5 is based on a centrosymmetric Sn2O2
unit connected to a pair of exocyclic Sn atoms via bridging oxygen
atoms, so that the bridging oxygen atoms are tri-coordinative and
cap three tin atoms. There are two diverse carboxylate groups in
this structure. One carboxylate ligand is bidentate bridging and
bridges both the endocyclic and exocyclic Sn atoms via O(1) and
O(2) atoms, and the other carboxylate ligand is monodentate.
The endocyclic tin atom, Sn(2), forms five significant bonds in this
structure. A coordination number of six is found for the exocyclic
Fig. 6. The molecular structure of complex 4 (the phenyl groups are omitted for
clarity).

628
J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
Table 5
planar (Me2Sn)2O2 four-membered ring and two peripheral Me2Sn
Selected bond lengths (Å) and angles (°) for complexes 5–7.
units. Each bridging oxygen atom in the Sn2O2 ring is attached to
three Me2Sn units and as a result these oxygen atoms are three-
coordinated. The geometries of all the tin atoms in complex 6
can be classified into two types: pentacoordinated tin (Sn(1) and
Sn(3)), and hexacoordinated tin (Sn(2) and Sn(4)). Each of the pen-
tacoordinated tin atoms, Sn(1) for example, forms three short Sn–O
bonds with three oxygen atoms: one from the Sn2O2 moiety and
the other two from two different carboxylate groups. Together
with the two bonds to methyl groups, the geometry of the Sn(1)
atom may be viewed as a slightly distorted trigonal bipyramid with
the axial site occupied by two different carboxylic oxygen atoms.
Each of the hexacoordinated tin atoms, Sn(2) for example, has an
octahedral geometry with four equatorial oxygen atoms and two
axial carbon atoms, the geometry being somewhat distorted by
the small angles in the stannoxane rings, affecting the equatorial
angles. As shown in Fig. 8, complex 6 forms a one-dimensional infi-
nite chain linked by bidentate carboxylic oxygen atoms. This struc-
Complex 5
Sn(1)–O(5)
Sn(1)–O(5)#1
Sn(1)–O(1)
Sn(2)–O(5)
2.059(9)
2.125(9)
2.321(11)
2.029(10)
2.086(19)
76.3(4)
162.8(4)
91.5(4)
92.8(6)
Sn(1)–C(15)
Sn(1)–C(19)
Sn(1)–Sn(1)#1
Sn(2)–C(23)
Sn(2)–O(3)
O(5)–Sn(1)–O(1)
O(5)–Sn(2)–O(3)
O(3)–Sn(2)–O(2)
C(23)–Sn(2)–O(3)
2.075(18)
2.132(19)
3.2898(18)
2.071(19)
2.203(9)
87.4(4)
77.5(4)
167.9(4)
92.3(6)
Sn(2)–C(27)
O(5)–Sn(1)–O(5)#1
O(5)#1–Sn(1)–O(1)
O(5)–Sn(2)–O(2)
C(27)–Sn(2)–O(2)
Complex 6
Sn(1)–O(1)
Sn(1)–O(3)
Sn(1)–O(8)#1
Sn(2)–C(31)
Sn(2)–O(5)
Sn(3)–O(2)
Sn(3)–O(7)
Sn(4)–O(2)
2.071(4)
2.215(5)
2.515(5)
2.100(8)
2.314(6)
2.001(4)
2.246(5)
2.125(4)
Sn(1)–C(29)
Sn(1)–O(9)
Sn(2)–O(2)
Sn(2)–O(1)
Sn(2)–O(4)
Sn(3)–O(6)
Sn(4)–O(1)
Sn(4)–O(10)
2.100(7)
2.296(5)
2.078(4)
2.132(4)
2.436(5)
2.233(5)
2.039(4)
2.295(5)
O(1)–Sn(1)–O(3)
O(3)–Sn(1)–O(9)
O(3)–Sn(1)–O(8)#1
O(2)–Sn(2)–O(5)
O(2)–Sn(2)–O(4)
O(5)–Sn(2)–O(4)
O(1)–Sn(2)–Sn(4)
O(2)–Sn(3)–O(6)
O(1)–Sn(4)–O(10)
94.72(18)
170.18(19)
76.82(18)
87.05(19)
163.41(17)
109.48(19)
37.50(11)
92.40(19)
88.07(18)
O(1)–Sn(1)–O(9)
O(1)–Sn(1)–O(8)#1
O(2)–Sn(2)–O(1)
O(1)–Sn(2)–O(5)
O(1)–Sn(2)–O(4)
O(2)–Sn(2)–Sn(4)
O(5)–Sn(2)–Sn(4)
O(2)–Sn(3)–O(7)
O(1)–Sn(4)–Sn(2)
95.10(18)
171.54(18)
76.77(17)3
163.72(19)
86.66(16)
39.54(12)
126.22(15)
79.27(17)
39.52(12)
tural feature of complex
6 is quite different from that of
{(Me2Sn(OAc)2O)2}n, one-dimensional organotin polymer in
a
which the acetate links the dimeric tetraorganodistannoxane units
in a tetradentate mode [30].
The structure of complex 7 is different from complexes 5 and 6.
In complex 7 only two carboxylate ligands coordinate to the tin
atoms, and all the ligands are monodentate. Furthermore, two sol-
vent methanol molecules coordinate to the tin atoms, together
with the two bonds of benzyl groups and the tri-coordinative oxy-
gen atoms, so all the tin atoms in complex 7 are five-coordinated
and the geometry of the tin atoms is trigonal bipyramidal. All the
bond lengths and bond angles are similar those in complexes 5
and 6.
Complex 7
Sn(1)–O(3)
Sn(1)–C(8)
Sn(1)–O(4)
2.034(3)
2.148(6)
2.262(4)
2.122(6)
2.138(3)
82.95(14)
153.82(14)
73.86(14)
97.5(2)
Sn(1)–C(15)
Sn(1)–O(1)
Sn(2)–O(3)
Sn(2)–O(4)
2.142(6)
2.158(4)
2.048(3)
2.126(4)
2.156(6)
71.16(13)
73.78(13)
95.9(2)
Sn(2)–C(22)
Sn(2)–O(3)#1
O(3)–Sn(1)–O(1)
O(1)–Sn(1)–O(4)
O(3)–Sn(2)–O(3)#1
O(4)–Sn(2)–C(29)
Sn(2)–C(29)
O(3)–Sn(1)–O(4)
O(3)–Sn(2)–O(4)
C(22)–Sn(2)–O(3)#1
O(3)#1–Sn(2)–C(29)
3. Conclusion
98.6(2)
Symmetry code for complex 5: #1 Àx + 1, Ày + 1, Àz + 1; symmetry code for com-
plex 6: #1 Àx + 1, Ày + 1, Àz + 1; symmetry code for complex 7: #1 Àx + 1, Ày + 1,
Àz + 1.
In summary, we have obtained a series of new organotin (IV)
carboxylates by the reactions of 6-chloro-3-pyridineacetic acid
with triorganotin chloride and diorganotin dichloride. In our work,
various structures are found, including 1D spring-like helical chain,
infinite zigzag chain, drum, monomer and ladders. Especially, in
complex 1 a novel spring-like helical chain containing guest sol-
vent molecules is observed, which has not been reported previ-
ously in the literature. It should be noted that although the
carboxylic acid ligand has a heterocyclic nitrogen atom, the nitro-
gen atom does not show any obvious interaction to the tin atoms;
maybe spatial hindrance from the organic groups blocks the nitro-
tin atom, Sn(1), which exists in a octahedral geometry with the car-
boxylate oxygen atoms in trans positions. As a consequence, the
endocyclic and exocyclic tin atoms are six-coordinated and five-
coordinated, respectively.
The predominant structural form of complex 6 is a dimeric dic-
arboxylatotetraorganodistannoxane, which consists of a central
Fig. 7. The molecular structure of complex 5 (only one carbon atom of the butyl group is shown for clarity).

J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
629
Fig. 8. The 1D infinite chain structure of complex 6 (the methyl groups are omitted for clarity).
less otherwise specified; the 13C NMR spectra are broadband
proton decoupled. The chemical shifts were reported in ppm with
respect to the references and were stated relative to external tetra-
methylsilane (TMS) for 1H and 13C NMR spectra, and to neat
tetramethyltin for 119Sn NMR spectra [31]. Elemental analyses (C,
H and N) were performed with a PE-2400II apparatus.
4.2. Syntheses of complexes 1–7
4.2.1. {(Ph3Sn)[(COO)(CH2C5H3NCl)]}n (1)
6-Chloro-3-pyridineacetic acid (0.172 g, 1 mmol) and sodium
ethoxide (0.068 g, 1 mmol) were added to a solution of benzene
(30 ml) in a Schlenk flask, and the mixture was stirred for
10 min. Then triphenyltin chloride (0.385 g, 1.00 mmol) was added
to the mixture, and the reaction mixture was stirred for 12 h at
40 °C. The solution was filtered and the filtrate was gradually re-
moved by evaporation under vacuum until a solid product was ob-
tained. Crystals of complex 1 were obtained by recrystallisation
from dichloromethane. Yield: 70%. M.p. 144–146 °C. Anal. Calc.
for C268H218Cl10N10O20Sn10: C, 59.17; H, 4.04; N, 2.57. Found: C,
Fig. 9. The molecular structure of complex 7 (only one carbon atom of the benzyl
group is shown for clarity).
59.48; H, 4.33; N, 2.24%. IR (KBr, cmÀ1): 1622
m
as(COO), 1419
ms(COO), 511 m(Sn-C), 442 m
(Sn-O). 1H NMR (CDCl3) d (ppm):
gen atom from coordinating to the tin atoms. These organotin
structures reported in this paper further enrich organotin chemis-
try in the structural field.
7.24–8.29 (m, 198H, Ar-H), 3.58 (s, 20H, CH2). 13C NMR (CDCl3) d
(ppm): 174.6 (COO), 124.1–150.9 (Ar-C), 37.6 (CH2). 119Sn NMR d
(ppm): À118.5.
4. Experimental details
4.2.2. {(Me3Sn)[(COO)(CH2C5H3NCl)]}n (2)
4.1. Materials and measurements
Complex 2 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), trimethyltin chloride (0.199 g, 1 mmol) and
benzene (30 ml). Crystals of complex 2 were obtained on recrystal-
lisation from dichloromethane. Yield: 75%. M.p. 156–158 °C. Anal.
Calc. for C20H28Cl2N2O4Sn2: C, 35.92; H, 4.22; N, 4.19. Found: C,
Triorganotin chloride, diorganotin dichloride and 6-chloro-3-
pyridineacetic acid are commercially available and they were used
without further purification. The melting points were obtained
with an X-4 digital micro melting-point apparatus and were uncor-
rected. Infrared-spectra were recorded on a Nicolet-5700 spectro-
photometer using KBr discs and sodium chloride optics. 1H, 13C
and 119Sn NMR spectra were recorded on a Varian Mercury Plus
400 spectrometer operating at 400, 100.6 and 149.2 MHz, respec-
tively. The spectra were acquired at room temperature (298 K) un-
36.17; H, 4.51; N, 3.95%. IR (KBr, cmÀ1): 1628
m
as(COO), 1433
ms(COO), 508 m(Sn-C), 462 m
(Sn-O). 1H NMR (CDCl3) d (ppm):
7.01–8.66 (m, 6H, Ar-H), 3.32 (s, 4H, CH2), 0.88 (s, 18H, CH3). 13C
NMR (CDCl3) d (ppm): 175.3 (COO), 122.8–150.1 (Ar-C), 38.3
(CH2), 13.8 (CH3). 119Sn NMR d (ppm): À133.7.

630
J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
4.2.3. {(PhCH2)3Sn)[(COO)(CH2C5H3NCl)]}ÁH2O (3)
4.2.5. {(Bu2Sn)2(O)[(COO)(CH2C5H3NCl)]2} (5)
Complex 3 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), tribenzyltin chloride (0.427 g, 1 mmol) and,
benzene (30 ml). Crystals of complex 3 were obtained on recrystal-
lisation from dichloromethane. Yield: 69%. M.p. 137–139 °C. Anal.
Calc. for C28H28ClNO3Sn: C, 57.91; H, 4.86; N, 2.41. Found: C,
Complex 5 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), dibutyltin dichloride (0.303 g, 1 mmol) and
methanol (30 ml). Crystals of complex 5 were obtained by recrys-
tallisation from diethyl ether. Yield: 78%. M.p. 182–184 °C. Anal.
Calc. for C60H92Cl4N4O10Sn4: C, 43.78; H, 5.63; N, 3.40. Found: C,
57.63; H, 4.59; N, 2.68%. IR (KBr, cmÀ1): 1657
mas(COO), 1403
43.95; H, 5.32; N, 3.64%. IR (KBr, cmÀ1): 1673, 1589
mas(COO),
m
s(COO), 523 (Sn-C), 435
m
m
(Sn-O). 1H NMR (CDCl3) d (ppm):
1412, 1391 s(COO), 653 (O-Sn-O), 524 (Sn-C), 437
m
m
m
m
(Sn-O). 1H
7.17–8.28 (m, 18H, Ar-H), 3.67 (s, 2H, CH2), 2.35 (s, 6H, Sn-CH2).
13C NMR (CDCl3) d (ppm): 172.8 (COO), 127.5–149.7 (Ar-C), 37.9
(CH2), 26.8 (CH2–Sn). 119Sn NMR d (ppm): 48.2.
NMR (CDCl3) d (ppm): 7.28–8.29 (m, 12H, Ar-H), 3.50 (s, 8H, Ar-
CH2), 1.21–1.58 (m, 48H, CH2–CH2–CH2), 0.87 (t, 24H, CH3). 13C
NMR (CDCl3) d (ppm): 177.5 (COO), 121.9–150.4 (Ar-C), 37.6 (Ar-
CH2), 25.4–29.1 (Sn-CH2–CH2–CH2), 13.6 (CH3). 119Sn NMR d
(ppm): À263.8, À137.2.
4.2.4. [PhSn(O)(COO)(CH2C5H3NCl)]6 (4)
Complex 4 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), diphenyltin dichloride (0.343 g, 1 mmol) and
methanol (30 ml). Crystals of complex 4 were obtained on recrys-
tallisation from diethyl ether. Yield: 67%. M.p. 211–213 °C. Anal.
Calc. for C78H60Cl6N6O18Sn6: C, 40.83; H, 2.64; N, 3.66. Found: C,
4.2.6. {(Me2Sn)2(O)[(COO)(CH2C5H3NCl)]2}n (6)
Complex 6 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), dimethyltin dichloride (0.219 g, 1 mmol) and
methanol (30 ml). Crystals of complex 6 were obtained by recrys-
tallisation from diethyl ether. Yield: 75%. M.p. 150–152 °C. Anal.
Cacl. for C36H44Cl4N4O10Sn4: C, 33.02; H, 3.39; N, 4.28. Found: C,
40.57; H, 2.45; N, 3.86%. IR (KBr, cmÀ1): 1586
m
as(COO), 1382
m
s(COO), 648 m(O-Sn-O), 515 m(Sn-C), 452 m
(Sn-O). 1H NMR (CDCl3)
d (ppm): 7.18–8.42 (m, 48H, Ar-H), 3.45 (s, 12H, CH2). 13C NMR
(CDCl3) d (ppm): 173.1 (COO), 124.1–150.1 (Ar-C), 37.5 (CH2).
119Sn NMR d (ppm): À340.6.
33.34; H, 3.65; N, 4.02%. IR (KBr, cmÀ1): 1590
s(COO), 649 (O-Sn-O), 520 (Sn-C),
(Sn-O) 446. 1H NMR (CDCl3)
d (ppm): 7.26–8.27 (m, 12H, Ar-H), 3.55 (s, 8H, Ar-CH2), 0.97 (s,
mas(COO), 1384
m
m
m
m
Table 6
Crystal data and structure refinement parameters for complexes 1–4.
Complex
1
2
3
4
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C
268H218Cl10N10O20Sn10
C20H28Cl2N2 O4Sn2
714.39
triclinic
C28H28ClNO3Sn
580.65
monoclinic
P2(1)/c
13.8291(14)
11.8991(12)
17.5097(16)
90
109.9180(10)
90
C78H60Cl6N6 O18Sn6
2294.16
triclinic
5443.70
monoclinic
Cc
ꢀ
ꢀ
P1
P1
15.3106(14)
51.192(5)
35.568(3)
90
99.814(2)
90
27470(4)
4
1.048
6.7992(11)
9.9628(15)
10.8971(16)
68.2320(10)
76.676(2)
71.0100(10)
643.13(17)
1
11.7306(10)
14.1721(14)
14.3501(15)
70.4470(10)
74.576(2)
72.3780(10)
2106.3(4)
1
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
2708.9(5)
4
1.070
Z
l
(mmÀ1
)
2.176
2.011
Reflections collected
35 718
3279
13 300
10 070
Independent reflections
33 261
1.036
2679
1.034
4772
1.085
7058
1.078
Goodness-of-fit (GOF) on F2
R1[I > 2
wR2[I > 2
r
(I)]/R1(all date)
(I)]/wR2(all date)
0.1339, 0.3355
0.2673, 0.4086
0.0557, 0.1322
0.0697, 0.1446
0.0325, 0.0614
0.0639, 0.0789
0.0910, 0.2329
0.1549, 0.2989
r
Table 7
Crystal data and structure refinement parameters for complexes 5–7.
Complex
5
6
7
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C
60H92Cl4N4O10Sn4
C36H44Cl4N4O10Sn4
1309.31
triclinic
C72H72Cl2N2O8Sn4
1638.98
triclinic
1645.94
triclinic
P1
ꢀ
ꢀ
ꢀ
P1
P1
12.1092(13)
13.1921(12)
14.4226(16)
116.025(2)
112.733(2)
90.7050(10)
1863.0(3)
1
11.1222(12)
14.9057(14)
14.9836(16)
93.4660(10)
96.8020(10)
107.617(2)
2338.7(4)
2
12.2782(12)
12.5445(13)
13.5161(15)
106.8910(10)
104.0540(10)
112.305(2)
1690.0(3)
1
b (Å)
c (Å)
a
(°)
b (°)
c
(°)
V (Å3)
Z
l
(mmÀ1
)
1.519
2.394
1.596
Reflections collected
8820
12 078
8695
Independent reflections
6095
1.076
8077
1.020
5806
1.124
Goodness-of-fit (GOF) on F2
R1[I > 2
wR2[I > 2
r
(I)]/R1(all date)
(I)]/wR2(all date)
0.0772, 0.1834
0.1470, 0.2590
0.0453, 0.1083
0.0811, 0.1360
0.0346, 0.0704
0.0597, 0.0901
r

J.-H. Zhang et al. / Polyhedron 30 (2011) 624–631
631
24H, CH3). 13C NMR (CDCl3) d (ppm): 173.3 (COO), 124.1–150.2
(Ar-C), 37.7 (Ar-CH2), 14.1 (CH3). 119Sn NMR d (ppm): À253.7,
À149.5.
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ,
UK; fax: (+44) 1223-336-033; or e-mail: deposit@ccdc.cam.ac.uk.
References
4.2.7. {[(PhCH2)2Sn)]2 [(O)(COO)(CH2C5H3NCl)]}Á2CH3O (7)
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Complex 7 was prepared in a similar way to complex 1, using 6-
chloro-3-pyridineacetic acid (0.172 g, 1 mmol), sodium ethoxide
(0.068 g, 1 mmol), dibenzyltin dichloride (0.219 g, 1 mmol) and
methanol (30 ml). Crystals of complex were obtained by recrystal-
lisation from diethyl ether. Yield: 72%. M.p. 164–166 °C. Anal. Cacl.
for C72H72Cl2N2O8Sn4: C, 52.76; H, 4.43; N, 1.71. Found: C, 52.51; H,
4.71; N, 1.53%. IR (KBr, cmÀ1): 1654
(O-Sn-O), 515 (Sn-C), 438
(Sn-O). 1H NMR (CDCl3) d (ppm):
mas(COO), 1407 ms(COO), 651
m
m
m
7.16–8.28 (m, 46H, Ar-H), 3.67 (s, 4H, CH2), 3.18 (s, 16H, Sn-CH2).
13C NMR (CDCl3) d (ppm): 172.5 (COO), 123.9–150.1 (Ar-C), 38.2
(Ar-CH2). 119Sn NMR d (ppm): À18.3.
4.3. X-ray crystallographic studies
X-ray crystallographic data were collected on a Bruker SMART
CCD 1000 diffractometer with graphite monochromated Mo K
a
radiation (k = 0.71073 Å) at 298(2) K. A semi-empirical absorption
correction was applied to the data. The structure was solved by di-
rect methods using SHELXS-97 and refined against F2 by full-matrix
least squares using SHELXL-97. Hydrogen atoms were placed in cal-
culated positions. Figures in this paper were created by the X-Seed
software packages. Crystal data and experimental details of the
structure determinations are listed in Tables 6 and 7.
Acknowledgement
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We thank the National Natural Science Foundation of China for
the financial support of this research (Grant No. 20971096).
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Appendix A. Supplementary data
CCDC 739402, 737072, 742568, 740790, 737073, 737074 and
755877 contain the supplementary crystallographic data for com-
plexes 1–7. These data can be obtained free of charge via http://
www.ccdc.cam.ac.uk/conts/retrieving.html, or from the Cambridge