Synthesis, characterizations and crystal structures of di-n-butyltin(IV) complexes with heteroatomic (N, O or S) acid

Article abstract of DOI:10.1016/j.jorganchem.2004.02.024

Two types of di- n -butyltin(IV) complexes {[ⁿBu₂ Sn(O₂CR)]₂O}₂ · L 1-4 and ⁿBu₂Sn(O₂CR)₂Y 5-8 (when L=H₂O, R=2-pyrazine 1; L=0, R=2-pyrimidylthi

Full text of DOI:10.1016/j.jorganchem.2004.02.024

Journal of Organometallic Chemistry 689 (2004) 1675–1683
www.elsevier.com/locate/jorganchem
Synthesis, characterizations and crystal structures of
di-n-butyltin(IV) complexes with heteroatomic (N, O or S) acid
a,b,
a
a
Chunlin Ma
*, Yinfeng Han , Rufen Zhang
a
Department of Chemistry, Liaocheng University, 34 Wenhua Road, Liaocheng 252059, Peopleꢀs PR China
Taishan University, Taian 271021, PR China
b
Received 1 January 2004; accepted 24 February 2004
Abstract
n
Two types of di-n-butyltin(IV) complexes {[nBu2Sn(O2CR)]2O}2 Æ L 1–4 and Bu2Sn(O2CR)2Y 5–8 (when L ¼ H2O, R ¼ 2-pyr-
azine 1; L ¼ 0, R ¼ 2-pyrimidylthiomethylene 2, 1-naphthoxymethylene 3; L ¼ C6H6, R ¼ 2-naphthoxymethylene 4; when Y ¼ H2O,
R ¼ 2-pyrazine 5; Y ¼ 0, R ¼ 2-pyrimidylthiomethylene 6, 1-naphthoxymethylene 7, 2-naphthoxymethylene 8) have been prepared in
1:1 or 1:2 molar ratios by reactions of di-n-butyltin oxide with the heteroatomic (N, O or S) carboxylic acids. The complexes 1–8 are
1
characterized by elemental, IR, H and 13C NMR spectra. And except for complexes 6 and 7, the complexes 1–5 and 8 are also
characterized by X-ray crystallography diffraction analyses, which reveal that the tin atom of complex 5 is seven-coordinated, while
the complexes 1–4 and 8 are all hexa-coordinated. The nitrogen atom of the aromatic ring in complexes 1 and 5 participates in the
interactions with the Sn atom.
ꢀ 2004 Elsevier B.V. All rights reserved.
Keywords: Di-n-butyltin oxide; Heteratomic acid; Tetranuclear centrosymmetric dimeric; Skew-trapezoidal; Crystal structure
1. Introduction
structural and the Sn atom has skew-trapezoidal plan-
nar geometry [1d,6].
Organotin carbonxylates have been the subjects of
interest for some time because of their biochemical and
commercial applications [1]. In general, the biochemical
activity of organotin carbonxylates is influenced greatly
by the structure of the molecule and the coordination
number of the tin atoms [2–4]. Recent review on struc-
tures of organotin carboxylates has demonstrated that
when a 1:1 (tin/ligand) ratio is used, there are five types
of structure adopted in the crystalline state by the di-
meric dicarboxylatorganodistannoxanes [1d,5]. A char-
acteristic feature of these complexes in the solid state is
their dimerization that results in the so-called ladder or
staircase arrangement that contains a central planar
Sn2O2 four-membered ring. When a 1:2 ratio is used, a
diorganotin dicarboxylate is formed. They are mono-
Despite such extensive studies being carried out on
theme, the report on the formal coordination to the Sn
atoms of additional hetero-atoms in these organotin
carboxylates is rare [7,8]. Our current interest is whether
or not the hetero-atoms (N, O or S) of the carboxylic
acids are to influence the coordination mode and further
help the self-assemble of these molecules. Out of above
consideration, we design a series of experiments of di-n-
butyltin oxide with 2-pyrazinecarboxylic acid, (2-py-
rimidylthio)acetic acid, 1-naphthoxyacetic acid and
2-naphthoxyacetic acid, respectively. With 1:1 ratio (tin/
ligand), we obtain four di-n-butyltin(IV) ladder com-
plexes 1–4 of the type {[nBu2Sn(O2CR)]2O}2 Æ L (L ¼
H2O, R ¼ 2-pyrazine 1; L ¼ 0, R ¼ 2-pyrimidylthiom-
ethylene 2, 1-naphthoxymethylene 3; L ¼ C6H6, R ¼ 2-
naphthoxymethylene 4). With 1:2 ratio, another four
mononuclear complexes 5–8 are obtained and the
n
general formula is Bu2Sn(O2CR)2Y (Y ¼ H2O, R ¼ 2-
* Corresponding author. Tel.: +86-635-8238121; fax: +86-635-
8238274/538-6715521.
E-mail address: macl@lctu.edu.cn (C. Ma).
pyrazine 5; Y ¼ 0, R ¼ 2-pyrimidylthiomethylene 6,
1-naphthoxymethylene, 7, 2-naphthoxymethylene, 8).
0022-328X/$ - see front matter ꢀ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.02.024

1676
C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
2. Results and discussion
2.1. Synthesis
ligands, single resonance are observed at 7.46, 8.51, 9.27
and 9.31 ppm, respectively, which is absent in the
spectra of the complexes indicating the replacement of
the carboxylic acid proton by a diorganotin moiety on
complex formation. In addition, the resonance appears
at 3.62 for complexes 2 and 3.61 ppm for complex 6 are
attributed to the protons of (–S–CH2) and the resonance
at 4.41–4.53 ppm for complexes 3, 4, 7 and 8 is assigned
to the protons of (–O–CH2), which further testify their
formations. Signals for the other groups appear at the
same position as in the ligands.
Reactions of di-n-butyltin oxide with 2-pyrazine-
carboxylic acid, (2-pyrimidylthio)acetic acid, 1-naphth-
oxyacetic acid and 2-naphthoxyacetic acid in 1:1 or 1:2
stoichiometry in refluxing benzene, which afford air-
stable complexes. The synthesis procedures are shown in
Scheme 1.
2.2. Spectroscopic studies
The 13C NMR data for the complexes 1–4 are con-
sistent with a dimeric tetraorganostannoxane structure.
Although at least two different types of carboxylate
groups are present, only single resnances are observed
for the COO group in the 13C spectra. The possible
reason is that either accidental magnetic 0uivalence of
the carbonyl carbon atoms or the separations between
the two sets of resonance are small to be resolved.
Complementary information for several complexes is
2.2.1. IR spectra
The stretching frequencies of interest are those asso-
ciated with the acid COO, Sn–C, Sn–O and Sn–O–Sn
groups. The spectra of all the complexes 1–8 show some
common characters. The explicit feature in the infrared
spectra of all complexes 1–8 is the absence of the band in
the region 2600–3436 cmꢀ1, which appears in the free-
ligand as the m(O–H) vibration, indicating metal-ligand
bond formation through this site. While strong absorp-
tion appears at 474–492 cmꢀ1 in the respective spectra of
the complexes 1–8, which is absent in the spectra of the
free ligand, is assigned to the Sn–O stretching mode of
vibration. All these values are consistent with that de-
tected in a number of organotin(IV)–oxygen derivatives
[9,10]. The observation of two Sn–C absorption bands in
the 532–576 cmꢀ1 regions reveals a non-linear trans
configuration of the C–Sn–C moiety [11].
1
given by the values of the coupling constant. The JSnC
value for 1 are 615 and 750 Hz, similar to that of the
hexa-coordinated compound {[nBu2Sn(2-pic)]2O2} [8a],
ꢀ
and the calculated h (C–Sn–C) by the Holecek and
ꢀ
Lycka equation [12] are 136.2ꢁ and 149.7ꢁ, which are
close to the angles observed in the solid state for com-
plex 1. The same coincidence can be found in complexes
1
2, 3, 4 and 8. The JSnC values, 622 Hz for 2, 637 Hz
for 3, 631 and 710 Hz for 4, 609 Hz for 8, are in keep
with those reported in hexa-coordinated compounds
{[nBu2Sn(OCOC12H8NO2-40)]2O2} [13] and nBu2Sn-
(OCOC4H3Me-2)2 [14]. And the calculated h approach
to the C–Sn–C angles in the solid state, too. So it can
reasonably be assumed that the structure in solution of
all these complexes are likely similar to that observed in
the solid state.
Some obvious differences among the spectra of the
complexes 1–8 are also observed. A strong band in the
621–640 cmꢀ1 region for the {[(nBu)2Sn(O2CR)]2O}2 Æ L
complexes is assigned to m(Sn–O–Sn), indicating a Sn–
O–Sn bridged structure. For complexes 1 and 5, new
vibrations, which appear at about 445 and 461 cmꢀ1
,
attribute to Sn–N bonds and further testify their for-
mation. Above these are also confirmed by an X-ray
diffraction study.
2.3. X-ray crystallographic studies
Crystals were mounted in Lindemann capillaries un-
der nitrogen. Diffraction data were collected on a Smart
CCD area-detector with graphite monochromated
2.2.2. NMR spectroscopic
1
The H NMR spectra show the expected integration
and peak multiplicities. In the spectra of four free
ꢁ
Mo Ka radiation (k ¼ 0:71073 A). A semiempirical
{[nBu2Sn(O2CR)]2O}2L 1-4
C6H6
4nBu2SnO + 4RCOOH
SCH2-
N
OCH2-
OCH2-
N
N
1; L=0, R=
When L=H2O, R=
2;
3 ; L=C6H6, R=
4
N
nBu2SnO + 2RCOOH
nBu2Sn(O2CR)2Y 5-8
OCH2-
SCH2-
OCH2-
N
N
N
When Y=H2O, R=
Y=0, R=
6;
7;
8
5;
N
Scheme 1.

C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
1677
Table 1
Crystal, data collection and structure refinement parameters for complexes 1–5 and 8
Complex
1
2
3
4
5
8
Empirical formula C52H86N8O11Sn4
C56H92O10S4Sn4
1640.38
0.71073
C80H106O14Sn4
1766.41
0.71073
C88H114O14Sn4
1870.55
0.71073
C18H26N4O5Sn
497.12
0.71073
C32H36O6Sn
635.30
Formula weight
ꢁ
Wavelength (A)
1474.05
0.71073
Monoclinic
C2=c
0.71073
Monoclinic
Cc
Crystal system
Space group
Unit cell dimension
Triclinic
ꢂ
Triclinic
ꢂ
Monoclinic
C2=c
Rhombohedral
ꢂ
P1
P1
R3c
ꢁ
a (A)
17.309(8)
19.505(8)
19.083(9)
90
10.124(7)
12.967(8)
15.582(10)
68.996(8)
79.265(9)
71.858(9)
1
11.938(14)
13.569(15)
13.837(16)
103.934(16)
104.769(16)
99.691(17)
1
25.389(10)
18.400(7)
18.825(7)
90
25.132(19)
25.132(19)
17.699(19)
90
36.17(2)
5.031(3)
17.719(10)
90
ꢁ
b (A)
ꢁ
c (A)
a (ꢁ)
b(ꢁ)
c (ꢁ)
Z
Absorption
94.222(9)
90
92.603(7)
90
90
120
114.062(8)
90
4
1.594
4
1.183
18
1.224
4
0.910
1.535
1.269
coefficient
(mmꢀ1
)
Crystal size (mm) 0.42 · 0.28 · 0.23
0.55 · 0.45 · 0.40
2.36–25.03
0.35 · 0.32 · 0.27
1.82–25.03
0.28 · 0.25 · 0.21
2.46–25.03
0.22 · 0.13 · 0.09
2.49–25.02
0.52 · 0.43 · 0.14
2.31–25.02
h range for data
collection (ꢁ)
Index ranges
2.35–25.02
ꢀ18 6 h 6 20,
ꢀ23 6 k 6 18,
ꢀ14 6 l 6 22
16 609
ꢀ8 6 h 6 12,
ꢀ13 6 k 6 15,
ꢀ18 6 l 6 18
9087
ꢀ11 6 h 6 14,
ꢀ15 6 k 6 16,
ꢀ16 6 l 6 14
10 082
30 6 h 6 30,
ꢀ15 6 k 6 21,
ꢀ22 6 l 6 22
22 654
ꢀ28 6 h 6 29,
ꢀ25 6 k 6 29,
ꢀ21 6 l 6 20
15 343
ꢀ42 6 h 6 41,
ꢀ5 6 k 6 5,
ꢀ21 6 l 6 20
6985
Reflections
collected
Unique reflections 5632 (0.0617)
(Rint
6062 (0.0322)
6968 (0.0240)
7744 (0.1489)
1868 (0.0568)
4098 (0.0492)
)
Absorption
Semi-empirical
from equivalents
Full-matrix least-
Semi-empirical
from equivalents
Full-matrix least-
Semi-empirical
from equivalents
Full-matrix least-
Semi-empirical
from equivalents
Full-matrix least-
Semi-empirical
from equivalents
Full-matrix least-
Semi-empirical
from equivalents
Full-matrix least-
correction
Refinement
method
squivalants on F 2 squivalants on F 2 squivalants on F 2 squivalants on F 2 squivalants on F 2 squivalants on F 2
Data/restrainst/
parameters
Goodness of fit
on F 2
5632/74/314
6062/44/370
6968/44/442
7744/15/470
1868/6/132
4098/37/352
0.866
0.963
1.045
0.930
0.961
0.903
Final R indices
[I > 2rðIÞ]
R1 ¼ 0:0572,
wR2 ¼ 0:1381
R1 ¼ 0:0542,
wR2 ¼ 0:1324
R1 ¼ 0:0964,
wR2 ¼ 0:1601
R1 ¼ 0:0405,
wR2 ¼ 0:0872
R1 ¼ 0:0810,
wR2 ¼ 0:1124
R1 ¼ 0:0608,
wR2 ¼ 0:1252
R1 ¼ 0:1121,
wR2 ¼ 0:1519
R1 ¼ 0:0294,
wR2 ¼ 0:0653
R1 ¼ 0:0492,
wR2 ¼ 0:0725
R1 ¼ 0:0464,
wR2 ¼ 0:0924
R1 ¼ 0:0609,
wR2 ¼ 0:0969
R indices (all data) R1 ¼ 0:1381,
wR2 ¼ 0:1703
absorption correction was applied to the data. The
structure was solved by direct methods using SHELXS-97
and refined against F 2 by full-matrix least-squares using
SHELXL-97. Hydrogen atoms were placed in calculated
positions. Crystal data and experimental details of the
structure determinations are listed in Table 1.
2.3.1. Crystal structure of {[nBu2Sn(O2CN2H3C4)]2O}2
ꢁ H2O (1)
The molecular structure is illustrated in Fig. 1,
ꢁ
selected bond lengths (A) and angles (ꢁ) are listed in
Table 2. There have being significant intra- and inter-
molecular contacts in the crystal lattice. As observed for
the related structure [1b,15,16], the core geometry of the
molecule consists of a centrosymmetric planar four-
membered Sn2O2 ring with two additional nBu2Sn-
(O2CN2H3C4) units attach at each bridging oxygen
atom, with the result that these oxygen atoms are three
Fig. 1. Molecular structure of complex 1.

1678
C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
Table 2
ꢁ
Selected bond lengths (A) and angles (ꢁ) for complexes 1–4
Bond lengths
Bonds angles
Bonds angles
Complex 1
Sn(1)–O(5)#1
Sn(1)–O(5)
Sn(1)–C(11)
Sn(1)–C(15)
Sn(1)–O(1)
Sn(1)–N(1)
Sn(2)–O(5)
Sn(2)–C(19)
Sn(2)–C(23)
Sn(2)–O(3)
Sn(2)–O(1)#1
Sn(2)–N(3)
2.061(7)
2.115(7)
O(5)#1–Sn(1)–O(5)
O(5)#1–Sn(1)–C(11)
73.9(3)
104.8(5)
98.9(5)
103.0(6)
150.9(7)
67.8(3)
141.7(3)
91.8(5)
90.5(6)
126.9(3)
159.1(3)
77.5(4)
78.9(6)
59.1(3)
64.8(3)
O(5)–Sn(2)–C(19)
O(5)–Sn(2)–C(23)
C(19)–Sn(2)–C(23)
O(5)–Sn(2)–O(3)
C(19)–Sn(2)–O(3)
C(23)–Sn(2)–O(3)
O(5)–Sn(2)–O(3)
C(19)–Sn(2)–O(1)#1
C(23)–Sn(2)–O(1)#1
O(3)–Sn(2)–O(1)#1
O(5)–Sn(2)–N(3)
O(5)–Sn(2)–O(3)
C(19)–Sn(2)–N(3)
C(23)–Sn(2)–O(3)
C(19)–Sn(2)–O(3)
110.2(5)
109.9(5)
135.4(7)
75.8(3)
99.7(5)
108.2(5)
75.8(3)
90.9(5)
84.9(5)
146.0(3)
140.5(3)
75.8(3)
80.3(5)
81.1(5)
99.7(5)
2.137(13) O(5)–Sn(1)–C(11)
2.202(17) O(5)#1–Sn(1)–C(15)
2.461(8)
2.952(10) O(5)#1–Sn(1)–O(1)
2.006(7) O(5)–Sn(1)–O(1)
C(11)–Sn(1)–C(15)
2.136(14) C(11)–Sn(1)–O(1)
2.148(14) C(15)–Sn(1)–O(1)
2.151(9)
2.383(8)
O(5)#1–Sn(1)–N(1)
O(5)–Sn(1)–N(1)
2.734(10) C(11)–Sn(1)–N(1)
C(15)–Sn(1)–N(1)
O(1)–Sn(1)–N(1)
O(3)–Sn(2)–N(3)
Complex 2
Sn(1)–O(5)
Sn(1)–C(13)
Sn(1)–C(17)
Sn(1)–O(1)
Sn(1)–O(3)
Sn(1)–O(2)
Sn(2)–O(5)#1
Sn(2)–C(25)
Sn(2)–C(21)
Sn(2)–O(5)
Sn(2)–O(4)#1
Sn(2)–O(1)
2.035(4)
2.128(9)
2.148(11) C(13)–Sn(1)–C(17)
O(5)–Sn(1)–C(13)
O(5)–Sn(1)–C(17)
109.3(3)
112.2(3)
138.3(4)
78.61(19)
99.9(3)
O(5)#1–Sn(2)–C(25)
O(5)#1–Sn(2)–C(21)
C(25)–Sn(2)–C(21)
O(5)#1–Sn(2)–O(5)
C(25)–Sn(2)–O(5)
C(21)–Sn(2)–O(5)
O(5)#1–Sn(2)–O(4)#1
C(25)–Sn(2)–O(4)#1
C(21)–Sn(2)–O(4)#1
O(5)–Sn(2)–O(4)#1
O(5)#1–Sn(2)–O(1)
C(25)–Sn(2)–O(1)
C(21)–Sn(2)–O(1)
O(5)–Sn(2)–O(1)
107.7(3)
114.7(3)
136.6(4)
75.19(19)
100.8(3)
98.8(3)
2.158(5)
2.261(6)
3.005(6)
2.039(5)
2.112(8)
2.144(9)
2.154(5)
2.323(5)
2.728(5)
O(5)–Sn(1)–O(1)
C(13)–Sn(1)–O(1)
C(17)–Sn(1)–O(1)
O(5)–Sn(1)–O(3)
C(13)–Sn(1)–O(3)
C(17)–Sn(1)–O(3)
O(1)–Sn(1)–O(3)
O(5)–Sn(1)–O(2)
C(13)–Sn(1)–O(2)
C(17)–Sn(1)–O(2)
O(1)–Sn(1)–O(2)
O(3)–Sn(1)–O(2)
91.8(4)
89.6(2)
89.7(2)
88.3(3)
82.9(3)
90.8(3)
85.9(4)
166.1(2)
125.55(18)
80.4(3)
164.1(2)
139.70(18)
77.4(3)
78.8(4)
47.16(17)
144.78(18)
76.7(3)
64.71(17)
130.62(19)
O(4)#1–Sn(2)–O(1)
Complex 3
Sn(1)–O(7)
Sn(1)–C(25)
Sn(1)–C(29)
Sn(1)–O(4)
Sn(1)–O(1)
Sn(1)–O(5)
Sn(2)–O(7)#1
Sn(2)–C(33)
Sn(2)–C(37)
Sn(2)–O(7)
Sn(2)–O(2)#1
Sn(2)–O(4)
2.026(4)
2.120(7)
2.130(8)
2.178(5)
2.252(5)
2.865(6)
2.054(4)
2.102(8)
2.106(7)
2.161(4)
2.296(7)
2.822(5)
O(7)–Sn(1)–C(25)
O(7)–Sn(1)–C(29)
C(25)–Sn(1)–C(29)
O(7)–Sn(1)–O(4)
C(25)–Sn(1)–O(4)
C(29)–Sn(1)–O(4)
O(7)–Sn(1)–O(1)
C(25)–Sn(1)–O(1)
C(29)–Sn(1)–O(1)
O(4)–Sn(1)–O(1)
O(7)–Sn(1)–O(5)
C(25)–Sn(1)–O(5)
C(29)–Sn(1)–O(5)
O(4)–Sn(1)–O(5)
O(1)–Sn(1)–O(5)
111.1(2)
110.6(3)
137.3(3)
80.91(15)
95.9(3)
O(7)#1–Sn(2)–C(33)
O(7)#1–Sn(2)–C(37)
C(33)–Sn(2)–C(37)
O(7)#1–Sn(2)–O(7)
C(33)–Sn(2)–O(7)
C(37)–Sn(2)–O(7)
O(7)#1–Sn(2)–O(2)#1
C(33)–Sn(2)–O(2)#1
C(37)–Sn(2)–O(2)#1
O(7)–Sn(2)–O(2)#1
O(7)#1–Sn(2)–O(4)
C(33)–Sn(2)–O(4)
C(37)–Sn(2)–O(4)
O(7)–Sn(2)–O(4)
112.3(3)
106.7(2)
140.6(4)
76.07(16)
97.2(3)
99.2(3)
97.3(3)
90.42(15)
85.1(3)
85.9(3)
891.02(18)
84.1(3)
89.9(3)
171.3(16)
130.21(17)
76.9(2)
166.55(16)
140.82(14)
76.8(3)
83.3(3)
49.35(15)
139.14(16)
76.8(2)
64.86(13)
128.16(15)
O(2)#1–Sn(2)–O(4)
Complex 4
Sn(1)–O(1)
Sn(1)–C(25)
Sn(1)–C(29)
Sn(1)–O(5)
Sn(1)–O(2)
Sn(1)–O(6)
Sn(2)–O(1)
Sn(2)–C(33)
Sn(2)–C(37)
Sn(2)–O(1)#1
Sn(2)–O(3)
Sn(2)–O(5)#1
2.010(4)
2.124(8)
2.161(11) C(25)–Sn(1)–C(29)
O(1)–Sn(1)–C(25)
O(1)–Sn(1)–C(29)
111.9(3)
111.6(3)
136.6(4)
78.03(16)
94.5(3)
O(1)–Sn(2)–C(33)
O(1)–Sn(2)–C(37)
C(33)–Sn(2)–C(37)
O(1)–Sn(2)–O(1)#1
C(33)–Sn(2)–O(1)#1
C(37)–Sn(2)–O(1)#1
O(1)–Sn(2)–O(3)
106.1(2)
106.1(2)
146.7(3)
76.38(18)
98.1(2)
2.177(4)
2.215(5)
3.069(5)
2.066(4)
2.110(7)
2.115(8)
2.168(4)
2.294(5)
2.622(4)
O(1)–Sn(1)–O(5)
C(25)–Sn(1)–O(5)
C(29)–Sn(1)–O(5)
O(1)–Sn(1)–O(2)
C(25)–Sn(1)–O(2)
C(29)–Sn(1)–O(2)
O(5)–Sn(1)–O(2)
O(1)–Sn(1)–O(6)
C(25)–Sn(1)–O(6)
93.2(4)
97.4(3)
91.80(18)
89.7(3)
90.1(4)
88.55(17)
85.8(3)
86.8(3)
C(33)–Sn(2)–O(3)
C(37)–Sn(2)–O(3)
O(1)#1–Sn(2)–O(3)
O(1)–Sn(2)–O(5)#1
C(33)–Sn(2)–O(5)#1
169.83(18)
124.53(15)
78.1(3)
164.93(16)
142.43(16)
81.3(2)

C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
1679
Table 2 (continued)
Bond lengths
Bonds angles
Bonds angles
C(29)–Sn(1)–O(6)
O(5)–Sn(1)–O(6)
O(2)–Sn(1)–O(6)
76.7(3)
46.50(14)
143.65(17)
C(37)–Sn(2)–O(5)#1
O(1)#1–Sn(2)–O(5)#1
O(3)–Sn(2)–O(5)#1
78.3(2)
66.07(15)
129.00(16)
coordination. The two crystallographically unique
2-pyrazinecarboxylic ligands coordinate in different
ways. The ligand contains the O(1) and O(2) atoms
bridging two tin atoms only via the O(1) atom, Sn(1)–
ꢁ
ꢁ
O(1) 2.461(8) A and Sn(2)–O(1A) 2.383(8) A. Although
ꢁ
the O(2A) oxygen is 3.659(4) A from the Sn(2) atom, a
distance is slightly less than the sum of the van der
ꢁ
Waalꢀs radii for Sn and O of 3.74 A [17], it is not in-
dicative of a significant bonding interaction. The C–O
bond distance which associates with the oxygen atom
ꢁ
bridging the two tin atoms of 1.315(13) A is significantly
ꢁ
longer than the other C–O bond distance of 1.211(14) A
that suggests a partial localization of p-electron density
in the C(1)–O(2) bond, and it consists with the non-
coordination of the O(2) atom to Sn(2A). The nitrogen
atom from the 2-pyrazine ring of this ligand makes a
Fig. 2. Molecular structure of complex 2.
ꢁ
close contact with Sn(1) at 2.952(10) A, which is sig-
nificantly less than the sum of the van der Waalꢀs radii
ꢁ
for Sn and N of 3.74 A [17] and should be considered as
a bonding interaction. The O(3) of the second ligand in
{[nBu2Sn(O2CN2H3C4)]2O}2 forms a strong bond to
ꢁ
ꢁ
Sn(2), 2.151(9) A, and is 2.828(4) A from Sn(1). The
O(4) atom does not make any significant contacts with
the tin atoms. As for the first ligand, the C(6)–O(4)
ꢁ
1.196(14) A bond is shorter than the C(6)–O(3)
ꢁ
1.283(14) A. The weak Snꢁ ꢁ ꢁN interactions exist between
the Sn atom and the adjacent nitrogen atom, thereby
forming a chelate with a five-membered ring. Beside, co-
crystallization is found in the crystals and the co-crys-
tallized solvent is water with the molar ratio of
{[nBu2Sn(O2CN2H3C4)]2O}2:H2O is 1:1. The weak
hydrogen bonds are formed between {[nBu2Sn-
(O2CN2H3C4)]2O}2 and H2O which help the construc-
tion of one dimension infinite chain.
The endocyclic tin atom, Sn(1), is five-coordinate to a
first approximation and exists in a distorted trigonal bi-
pyramidal environment, with the two n-butyl groups and
the centrosymmetrically related bridging oxygen atom
defining an approximate trigonal plane. The apical posi-
tion is occupied by C(11) and C(15) atom from the ligand.
The C(11)–Sn–C(15), is 150.9(7)ꢁ. If the weakly bonded
N(1) atom is included in the coordination polyhedron, the
geometry about the tin atom can be consisted as being
distorted octahedron. The exocyclic tin atom, Sn(2),
forms four short bonds, a longer bond to O(5) and a weak
interaction. The geometry is highly distorted, the coor-
dination sphere can be thought of as distorted octahe-
dron, similar to Sn(1) atom.
Fig. 3. Molecular structure of complex 3.
2.3.2. Crystal structures of {[nBu2Sn(O2CCH2SN2-
H3C4)]2O}2 (2), {[nBu2Sn(O2CCH2OH7C10)]2O}2
(3) and {[nBu2Sn(O2CCH2OH7C10)]2O}2 ꢁ C6H6 (4)
The crystal structure of complexes 2, 3 and 4 are il-
lustrated in Figs. 2–4, respectively, selected bond lengths
and bond angles in Table 2. Significantly, there are no
intramolecular interactions between the Sn and S or O
atoms. The complexes are centrosymmetric dimmer
built up about the central cyclic Sn2O2 units. Two tin
atoms are linked to this four-membered ring with two

1680
C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
For complex 3 and 4, similar to the complex 2, the Sn(2)
atoms are bonded to two carbon and to four oxygen at-
ꢁ
oms, the longest Sn–O bonds are 2.822(5) A, Sn(2)–O(4)
ꢁ
and 2.622(4) A, Sn(2)–O(5), respectively. Two of the
carboxylates ligands are bidentate and bridge a pair of tin
atoms and the two other carboxylates are monodentate
and coordinate each exocyclic tin atom. The coordination
geometry of the tin atom Sn(2) are a distorted octahedron.
The coordination sphere of Sn(1) consists of two carbon,
three oxygen atoms and an intramolecular weak interac-
tion which derives from the monodentate carboxylate
group. The directionality of this weak interaction in-
volving the exocyclic tin atom Sn almost mimics that of
the endocyclic tin. The angles in the central Sn2O2 ring are
76.07(16)ꢁ and 103.93(16)ꢁ for complex 3, 76.38(18)ꢁ and
103.62(18)ꢁ for complex 4. Specially, for complex 4, co-
crystallization is found in the crystals and the co-crystal-
lized solvent is benzene with the molar ratio of
{[nBu2Sn(O2CCH2OH7C10)]2O}2: C6H6 is 1:1.
n
2.3.3. Crystal structure of Bu2Sn(O2CN2H3C4)2(H2O)
(5)
Fig. 4. Molecular structure of complex 4.
The crystal structure of complex 5 is shown in Fig. 5,
selected bond lengths and bond angles in Table 3.
Complex 5 contains a seven-coordinated tin atom and
has a pentagonal bipyramidal environment with C(6)
and C(6A) atoms occupying the axial sites and the axial–
Sn–axial, C(6)–Sn–C(6A) is 171.6(2)ꢁ. The tin atom lies
on a crystallographic twofold structure. Sn(1), O(1),
O(1A), N(1) and N(1A) are completely coplanar with
the tin atom existing in the plane. The sum of angles
between the tin atom and the equatorial atoms is 360ꢁ,
consistent with the ideal value of 360ꢁ. In the structure,
two carbons atoms and two nitrogen atoms of 2-pyra-
zinecarboxylic acid and the oxygen atom of water are
covalently linked to the tin. The Sn–N bond length
additional nBu2Sn(O2CR) units attach at each of the
bridging oxygen atoms, with the result that the oxygen
atoms of this ring are three-coordination. Although
there are two types of tin atom, the geometry about two
types is essentially identical. The weakly coordinating
oxygen atom approaches the coordinating sphere of tin
through one of the trigonal bipyramidal faces, making
the coordination number of all tin atoms achieve six.
The geometry of the tin atom is distorted octahedron.
For complex 2, the Sn(2) atom is bonded to two
carbon and to four oxygen atoms, the longest Sn–O
ꢁ
bond is 2.728(5) A, Sn(2)–O(1), while the others are
ꢁ
between 2.332(5) and 2.039(5) A. Two of the carboxy-
ꢁ
(Sn(1)–N(1) and Sn(1)–N(1)#1, 2.553(4) A) is longer
n
lates ligands are bidentate and bridge a pair of tin atoms
and the two other carboxylates are monodentate and
coordinate each exocyclic tin atom. The coordination
geometry of the tin atom Sn(2) is a distorted octahe-
dron. C(21) and C(25) atoms occupy the apical sites and
C(21)–Sn(2)–C(25), is 136.6(4)ꢁ. Sn(2), O(1), O(5),
O(5A) and O(4A) are almost coplanar with the tin atom
than those in Bu2Sn(OOCC5H4N-2)2(H2O) (2.2522(6)
ꢁ
deviating from the best plane by 0.0206 A. The sum of
angles between the tin atom and the equatorial atoms is
360.22ꢁ. Compared to the ideal octahedral value of 360ꢁ,
this further testifies the atoms in the same plane. The
coordination sphere of Sn(1) consists of two carbon and
three oxygen atoms, with Sn(1)–O bond lengths of
ꢁ
2.035(4)–3.261(6) A. There are, in addition, an intra-
ꢁ
molecular weak interaction, Sn(1)–O(2), 3.005(5) A,
which derives from the monodentate carboxylate group.
Interestingly, the directionality of this weak interaction
involving the exocyclic tin atom Sn almost mimics that
of the endocyclic tin. The angles in the central Sn2O2
ring are 75.19(19)ꢁ and 104.81(19)ꢁ.
Fig. 5. Molecular structure of complex 5.

C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
1681
Table 3
Selected bond lengths (A) and angles (ꢁ) for complexes 5 and 8
ꢁ
Bond lengths
Bonds angles
Bonds angles
Complex 5
Sn(1)–C(6)
Sn(1)–C(6)#1
Sn(1)–O(1)#1
Sn(1)–O(1)
Sn(1)–O(3)
Sn(1)–N(1)#1
Sn(1)–N(1)
2.121(4)
2.121(4)
2.232(3)
2.232(3)
2.384(4)
2.553(4)
2.553(4)
C(6)–Sn(1)–C(6)#1
C(6)–Sn(1)–O(1)#1
C(6)#1–Sn(1)–O(1)#1
C(6)–Sn(1)–O(1)
171.6(2)
C(6)#1–Sn(1)–N(1)#1
O(1)#1–Sn(1)–N(1)#1
O(1)–Sn(1)–N(1)#1
O(3)–Sn(1)–N(1)#1
C(6)–Sn(1)–N(1)
87.31(13)
68.04(10)
142.72(9)
74.62(7)
94.71(13)
92.01(13)
92.00(13)
74.68(14)
85.78(11)
85.78(11)
142.66(7)
142.66(7)
90.45(13)
O(1)#1–Sn(1)–O(1)
C(6)–Sn(1)–O(3)
87.31(13)
90.45(13)
142.72(9)
68.04(10)
74.62(7)
C(6)#1–Sn(1)–N(1)
O(1)#1–Sn(1)–N(1)
O(1)–Sn(1)–N(1)1
O(3)–Sn(1)–N(1)
C(6)#1–Sn(1)–O(3)
O(1)#1–Sn(1)–O(3)
O(1)–Sn(1)–O(3)
C(6)–Sn(1)–N(1)#1
N(1)#1–Sn(1)–N(1)
149.24(14)
Complex 8
Sn(1)–C(29)
Sn(1)–O(1)
Sn(1)–C(25)
Sn(1)–O(4)
Sn(1)–O(2)
Sn(1)–O(5)
Sn(1)–C(13)
2.057(15)
2.103(16)
2.144(9)
C(29)–Sn(1)–O(1)
C(29)–Sn(1)–C(25)
O(1)–Sn(1)–C(25)
C(29)–Sn(1)–O(4)
O(1)–Sn(1)–O(4)
C(25)–Sn(1)–O(4)
C(29)–Sn(1)–O(2)
O(1)–Sn(1)–O(2)
C(25)–Sn(1)–O(2)
100.6(8)
137.4(3)
111.6(7)
110.1(7)
79.3(2)
102.7(6)
89.1(6)
55.9(5)
86.9(6)
O(5)–Sn(1)–C(13)
O(4)–Sn(1)–O(5)
O(2)–Sn(1)–O(5)
O(4)–Sn(1)–O(2)
C(29)–Sn(1)–O(5)
C(25)–Sn(1)–C(13)
O(1)–Sn(1)–O(5)
C(25)–Sn(1)–O(5)
O(4)–Sn(1)–C(13)
26.9(5)
53.3(5)
172.48(17)
134.2(5)
87.1(6)
2.152(14)
2.519(15)
2.581(15)
2.667(12)
96.4(5)
131.3(5)
91.6(5)
26.6(6)
ꢁ
A) [18] but much shorter than the sum of the van der
ꢁ
waals radii of Sn and N, 3.74 A [17], and Sn–O(3)
ꢁ
2.383(4) A also approaches the sum of the covalent radii
ꢁ
of Sn and O (2.13 A) [17]. The valence extension is
possibly preformed via the two nitrogen atoms and the
oxygen atom of water. The intermolecular interactions
exist between the water and two adjacent molecules and
asymmetric Sn–O bond distances and this asymmetry is
reflected in the associated with the shorter Sn–O bonds.
The degree of asymmetry in the Sn–O bond distances is
not equal with the difference between Sn–O bond dis-
tance for the two carboxylate ligands being 0.416 and
ꢁ
0.429 A, respectively. The anisobidentate mode of co-
ordination of the carboxylato group is also reflected in
the disparity of the associated carbon–oxygen bonds.
ꢁ
result in hydrogen bonds O(3)–Hꢁ ꢁ ꢁO(2) (1.775 A).
ꢁ
Although the Sn(1)–O(2) 2.519(15) A and Sn(1)–O(5)
ꢁ
2.581(15) A bond lengths is longer than the sum of the
Through these, a three-dimensional hydrogen bonded
network is formed.
ꢁ
covalent radii of the tin and oxygen 2.13 A, it is never-
theless significantly below the sum of the van der Waalꢀs
ꢁ
radii of these atoms, 3.68 A [17].
2.3.4. Crystal structure of nBu2Sn(O2CCH2OH7C10)2
(8)
The crystal structure of complex 8 is shown in Fig. 6,
selected bond lengths and bond angles in Table 3. From
Fig. 6, we find that the Sn atom exists in a skew-trape-
zoidal planar geometry. The four O atoms, which derive
from two chelating carboxylate ligands, define the basal
plane. The nBu–Sn–nBu angle of 137.4(3)ꢁ lies in the
range of C–Sn–C angles of 122.6ꢁ–156.9ꢁ found for
diorganotin chelates in which the organo substituents do
not adopt cis- or trans-geometries about the tin atom
[19]. The carboxylate ligands chelate the Sn center with
Besides, intermolecular non-bonded Snꢁ ꢁ ꢁO interac-
tions are recognized in the crystallographic analysis of
ꢁ
complex 8. The Snꢁ ꢁ ꢁO bond length (3.624 A) is longer
ꢁ
than that reported in [Et2Sn(O2CC4H3S)] (2.891 A), but
ꢁ
similar to that of Ph2Sn(O2CCH2Cl)2 (3.552 A) [20,21].
Due to the very weak intermolecular interaction, one
chain is constructed. However, there is no evidence that
the presence or absence of the additional intermolecular
Snꢁ ꢁ ꢁO interactions have any other great effect on the
molecular geometry of complex 8.
2.4. Conclusion
In summary, we conclude that the difference of co-
ordination mode was derived from the residing position
of the heteroatoms. For nitrogen donors in 1 and 5, they
exist in the ring systems that would orient to make easy
coordination to tin. However, the ligands including S or
O are linear types that are not ease to make coordina-
tion to tin.
Fig. 6. Molecular structure of complex 8.

1682
C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
3. Experimental
41.00; H, 5.65; N, 6.83%. IR (KBr, cmꢀ1): mas(COO),
1653; ms(COO), 1384; m(Sn–C), 558; m(Sn–O), 492; m(Sn–
1
3.1. Materials and measurements
O–Sn), 640. H NMR (CDCl3, ppm): d 0.82(t, CH3),
1.30–1.77(m, CH2 Æ CH2 Æ CH2), 3.62 (s, –CH2S–). 13C
1
Di-n-butyltin oxide, 2-pyrazinecarboxylic acid, (2-
pyrimidylthio)acetic acid, 1-naphthoxyacetic acid and
2-naphthoxyacetic acid are commercially available,
and they are used without further purification.
The melting points were obtained with Kofler micro-
melting point apparatus and were uncorrected.
NMR (CDCl3, ppm): d 27.5 (aCH2, J(119Sn–13C), 622
Hz), 26.8 (bCH2), 26.3 (cCH2), 13.6 (CH3), 175.1
(COO).
3.2.3. Synthesis of {[nBu2Sn(O2CCH2OH7C10)]2O}2
(3)
Infrared-spectra were recorded on
a
Nicole-460
The complex 3 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to 1-naphthoxyacetic acid (0.404, 2 mmol). The
solid is then recrystallized from ethyl ether and the
purple crystal is obtained. Buff crystal complex 3 is
formed. Yield: 70%; m.p. 110–112 ꢁC. Anal. Found: C,
54.23; H, 5.97. Calc. for C80H106O14Sn4: C, 54.40; H,
6.05%. IR (KBr, cmꢀ1): mas(COO), 1632; ms(COO), 1376;
m(Sn–C), 572; m(Sn–O), 474; m(Sn–O–Sn), 622. 1H NMR
spectrophotometer using KBr discs and sodium chlo-
ride optics. 1H and 13C NMR spectra were recorded
on a Bruker AMX-300 spectrometer operating at 300
and 75.3 MHz, respectively. The spectra were ac-
quired at room temperature (298 K) unless otherwise
specified; 13C spectra are broadband proton decou-
pled. The chemical shifts were reported in ppm with
respect to the references and were stated relative to
external tetramethylsilane (TMS) for 1H and 13C
NMR. Elemental analyses were performed with a PE-
2400II apparatus.
(CDCl3, ppm):
d
0.88(t, CH3), 1.35–1.80(m,
CH2 Æ CH2 Æ CH2), 4.41 (s, –CH2O–). 13C NMR (CDCl3,
ppm): d 26.8 (aCH2, 1J(119Sn–13C), 637 Hz), 26.5
(bCH2), 26.3 (cCH2), 13.5 (CH3), 166.8 (COO).
3.2. Synthesis
3.2.4. Synthesis of {[nBu2Sn(O2CCH2OH7C10)]2O}2
ꢁ C6H6 (4)
3.2.1. Synthesis of {[nBu2Sn(O2CN2H3C4)]2O}2 ꢁ H2O
(1)
The complex 4 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to 2-naphthoxyacetic acid (0.404, 2 mmol). The
solid is then recrystallized from ethyl ether and the
purple crystal is obtained. Buff crystal complex 4 is
formed. Yield: 85%; m.p. 108–110 ꢁC. Anal. Found: C,
56.35; H, 6.05. Calc. for C88H114O14Sn4: C, 56.51; H,
6.14%. IR (KBr, cmꢀ1): mas(COO), 1631; ms2(COO),
The reaction is carried out under nitrogen atmo-
sphere. The di-n-butyltin oxide (0.496 g, 2 mmol) and
the 2-pyrazinecarboxylic acid (0.248, 2 mmol) are added
to the solution of dry benzene (30 ml) in a Schlenk flash.
The mixture gives a clear solution within 10–15 min.
Refluxing was continued for 10 h, the solvent is gradu-
ally removed by evaporation under vacuum until solid
product is obtained. The solid is then recrystallized from
ethyl ether and the white crystal is obtained. Buff crystal
complex 1 is formed. Yield: 81%. m.p. 106–108 ꢁC.
Anal. Found: C, 42.18; H, 6.00; N, 7.69. Calc. for
C52H86N8O11Sn4: C, 42.37; H, 5.88; N, 7.60%. IR (KBr,
cmꢀ1): mas(COO), 1667; ms(COO), 1377; m(Sn–C), 576;
m(Sn–O), 476; m(Sn–O–Sn), 621, m(Sn–N), 445. 1H NMR
1
1381; m(Sn–C), 532; m(Sn–O), 483; m(Sn–O–Sn), 637. H
NMR (CDCl3, ppm): d 0.87(t, CH3), 1.37–1.79(m,
CH2 Æ CH2 Æ CH2), 4.50 (s, –CH2O–). 13C NMR (CDCl3,
ppm): d 26.9 (aCH2, 1J(119Sn–13C), 631 Hz), 27.3
(aCH2, 1J(119Sn–13C), 710 Hz), 26.5 (bCH2), 26.7
(bCH2), 25.3 (cCH2), 25.1 (cCH2), 13.5 (CH3), 13.6
(CH3), 170.1 (COO).
(CDCl3, ppm):
d
0.80(t, CH3), 1.34–1.67(m,
n
CH2 Æ CH2 Æ CH2). 13C NMR (CDCl3, ppm): d 26.6
3.2.5. Synthesis of Bu2Sn(O2CN2H3C4)2(H2O) (5)
1
1
(aCH2, J(119Sn–13C), 615 Hz), 27.2 (aCH2, J(119Sn–
13C), 750 Hz), 26.3 (bCH2), 26.5 (bCH2), 25.6 (cCH2),
25.5 (cCH2), 12.8 (CH3), 13.3 (CH3), 174.2 (COO).
The complex 5 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to 2-pyrazinecarboxylic acid (0.596, 4 mmol).
The solid is then recrystallized from ethyl ether and the
white crystal is obtained. Buff crystal complex 5 is
formed. Yield: 86%; m.p. 186–188 ꢁC. Anal. Found: C,
43.32; H, 5.11; N, 11.33. Calc. for C18H26N4O5Sn: C,
43.49; H, 5.27; N, 11.27%. IR (KBr, cmꢀ1): mas(COO),
1640; ms(COO), 1342; m(Sn–C), 536; m(Sn–O), 485, m(Sn–
3.2.2. Synthesis of {[nBu2Sn(O2CCH2SN2H3C4)]2O}2
(2)
The complex 2 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to (2-pyrimidylthio)acetic acid (0.340, 2 mmol).
The solid is then recrystallized from ethyl ether and the
light-yellow crystal is obtained. Buff crystal complex 2 is
formed. Yield: 78%; m.p. 86–88 ꢁC. Anal. Found: C,
40.96; H, 5.62; N, 6.64. Calc. for C56H92N8O10S4Sn4: C,
1
N), 461. H NMR (CDCl3, ppm): d 0.82(t, CH3), 1.27–
1.70(m, CH2 Æ CH2 Æ CH2). 13C NMR (CDCl3, ppm): d
27.0 (aCH2, J(119Sn–13C), 891 Hz), 26.5 (bCH2), 25.8
1
(cCH2), 13.4 (CH3), 174.5 (COO).

C. Ma et al. / Journal of Organometallic Chemistry 689 (2004) 1675–1683
1683
n
3.2.6. Synthesis of Bu2Sn(O2CCH2SN2H3C4)2 (6)
e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
The complex 6 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to (2-pyrimidylthio)acetic acid (0.680, 4 mmol).
The solid is then recrystallized from ethyl ether and the
light-yellow crystal is obtained. Buff crystal complex 6 is
formed. Yield: 80%; m.p. 120–122 ꢁC. Anal. Found: C,
41.85; H, 5.12; N, 9.67. Calc. for C20H28N4O4S2Sn: C,
42.05; H, 4.94; N, 9.81%. IR (KBr, cmꢀ1): mas(COO),
Acknowledgements
We thank the National Nature Science Founda-
tion of China (20271025) and the National Nature Sci-
ence Foundation of Shandong Province for financial
supported.
1
1656; ms(COO), 1367; m(Sn–C), 542; m(Sn–O), 482. H
NMR (CDCl3, ppm): d 0.81(t, CH3), 1.43–1.80(m,
CH2 Æ CH2 Æ CH2), 3.61 (s, –CH2S–). 13C NMR (CDCl3,
ppm): d 27.7 (aCH2, 1J(119Sn–13C), 595 Hz), 26.7
(bCH2), 26.1 (cCH2), 13.5 (CH3), 176.0 (COO).
References
[1] (a) C.J. Evans, S. Karpel, Organotin Compounds in Modern
Technology, J. Organomet. Chem. Library, 16, Elsevier, Amster-
dam, 1985
n
3.2.7. Synthesis of Bu2Sn(O2CCH2OH7C10)2 (7)
The complex 7 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to 1-naphthoxyacetic acid (0.816, 4 mmol). The
solid is then recrystallized from ethyl ether and the
purple crystal is obtained. Buff crystal complex 7 is
formed. Yield: 90%; m.p. 127–129 ꢁC. Anal. Found: C,
60.37; H, 5.57. Calc. for C32H36O6Sn: C, 60.50; H,
5.71%. IR (KBr, cmꢀ1): mas(COO), 1643; ms(COO), 1359;
(b) S.P. Narula, S.K. Bhardwaj, H.K. Sharma, G. Mairesse, P.
Barbier, G. Nowogrocki, J. Chem. Soc., Dalton Trans. (1988) 1719;
(c) I. Haiduc, C. Silvetru, Coord. Chem. Rev. 99 (1990) 253;
(d) M. Gielen, Appl. Organomet. Chem. 16 (2002) 481.
[2] K.C. Molloy, T.G. Purcell, E. Hahn, H. Schumann, J.J. Zucker-
man, Organometallics 5 (1986) 85.
[3] R.R. Holmes, Acc. Chem. Res. 22 (1989) 190;
J. Otera, T. Yano, R. Owawara, Organometallics 5 (1986) 1167.
[4] J.A. Zubita, J.J. Zukerman, Inorg. Chem. 24 (1987) 251;
G.K. Sandhu, R. Gupta, S.S. Sandhu, R.V. Parish, Polyhedron 4
(1985) 81.
1
m(Sn–C), 551; m(Sn–O), 490. H NMR (CDCl3, ppm): d
0.91(t, CH3), 1.41–1.77(m, CH2 Æ CH2 Æ CH2), 4.49 (s, –
CH2O–). 13C NMR (CDCl3, ppm): d 27.1 (aCH2,
1J(119Sn–13C), 611Hz), 26.5 (bCH2), 26.3 (cCH2), 13.6
(CH3), 172.1 (COO).
[5] S.P. Narula, S. Kaur, R. Shankar, S.K. Bharadwaj, R.K. Chadha,
J. Organomet. Chem. 506 (1996) 181.
[6] J.X. Tao, W.J. Xiao, Q.C. Yang, J. Organomet. Chem. 531 (1997)
223;
S.G. Teoh, S.H. Ang, E.S. Looi, C.A. Keok, S.B. Teo, J.P.
Declercq, J. Organomet. Chem. 523 (1996) 75.
n
3.2.8. Synthesis of Bu2Sn(O2CCH2OH7C10)2 (8)
[7] S.P. Narula, S.K. Bharadwaj, Y. Sharda, D.C. Povey, G.W.
Smith, J. Organomet. Chem. 430 (1992) 167;
The complex 8 is prepared in the same way as that of
complex 1, by adding di-n-butyltin oxide (0.496 g, 2
mmol) to 2-naphthoxyacetic acid (0.816, 4 mmol). The
solid is then recrystallized from ethyl ether and the
purple crystal is obtained. Buff crystal complex 8 is
formed. Yield: 81%; m.p. 134–136 ꢁC. Anal. Found: C,
60.49; H, 5.65. Calc. for C32H36O6Sn: C, 60.50; H,
5.71%. IR (KBr, cmꢀ1): mas(COO), 1630; ms(COO), 1388;
S.W. Ng, C. Wei, V.G.K. Das, J. Organomet. Chem. 412 (1991) 39.
[8] (a) C.S. Parulekar, V.K. Jain, T.K. Das, A.R. Gupta, J. Organo-
met. Chem. 372 (1989) 193;
(b) T.P. Lockhart, Organometallics 7 (1988) 1438;
(c) E.R.T. Tiekink, G.K. Sandhu, S.P. Verma, Acta Crystallogr.,
Sect. C 45 (1989) 1810.
[9] R.R. Holmes, C.G. Schmid, V. Chandrasekhar, R.O. Day, J.M.
Homels, J. Am. Chem. Soc. 109 (1987) 1408.
1
m(Sn–C), 542; m(Sn–O), 483. H NMR (CDCl3, ppm): d
[10] G.K. Sandhu, R. Hundal, J. Organomet. Chem. 412 (1991) 31.
[11] G.K. Sandhu, N. Sharma, J. Organomet. Chem. 371 (1989) C1.
0.89(t, CH3), 1.39–1.83(m, CH2 Æ CH2 Æ CH2), 4.53 (s, –
CH2O–). 13C NMR (CDCl3, ppm): d 27.9 (aCH2,
1J(119Sn–13C), 609 Hz), 26.6 (bCH2), 26.2 (cCH2), 13.6
(CH3), 172.0 (COO).
ꢀ
ꢀ
[12] J. Holecek, A. Lycka, Inorg. Chim. Acta 118 (1986) L15.
[13] R. Kapoor, A. Gupta, P. Kapoor, P. Venugopalan, Appl.
Organomet. Chem. 17 (2003) 600.
[14] C.S. Parulekar, V.K. Jain, T. Kesavadas, J. Organomet. Chem.
387 (1990) 163.
[15] G. Valle, V. Peruzzo, G. Tagliavivi, P. Ganis, J. Organomet.
Chem. 276 (1984) 325.
4. Supplementary material
[16] R. Faggiani, J.P. Johnson, I.D. Brown, T. Birchall, Acta
Crystallogr., Sect. B 34 (1978) 3743.
Crystallographic data (excluding structure factors)
for the structure analysis of complexes 1–5 and 8 have
been deposited with the Cambridge Crystallographic
Data Center, CCDC Nos. 220167 (1), 221136 (2),
222377 (3), 220521 (4), 220168 (5) and 221138 (8).
Copies of these information may be obtained free of
charge from The Director, CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK (fax: +44-1223-336033;
[17] A. Bondi, J. Phys. Chem. 68 (1964) 441.
[18] C.L. Ma, H.D. Yin, C.H. Wang, Y. Wang, Chin. J. Chem. 20
(2002) 1608.
[19] S.W. Ng, C. Wei, V.G.K. Das, T.C.W. Mak, J. Organomet.
Chem. 334 (1987) 295.
[20] C. Vatsa, V.K. Jain, T. Kesavadas, J. Organomet. Chem. 410
(1991) 135.
[21] N.W. Alcock, J. Culver, S.M. Roe, J. Chem. Soc., Dalton Trans.
(1992) 1477.