Syntheses and crystal structures of four new organotin complexes with Schiff bases containing triazole

Article abstract of DOI:10.1016/j.jorganchem.2006.05.002

Four new organotin complexes, namely [(Bu₂Sn)₂O(EtO)(L1)]₂ (1), [(Bu₂Sn)₂O(EtO)(L2)]₂ (2), [(Bu₂Sn)₂O(EtO)(L3)]₂ (3) and [Ph₃Sn(L4)] · 0.5H₂O (4), were obtained by reactions of Bu₂SnO and Ph₃SnOH with 4-phenylideneamino-3-methyl-1,2,4-triazole-5-thione (HL1), 4-furfuralideneamino-3-methyl-1,2,4-triazole-5-thione (HL2), 4-(2-thienylideneamino)-3-ethyl-1,2,4 -triazole-5-thione (HL3) and 4-(3,5-di-t-butylsalicylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL4). Compounds 1-4 were characterized by elemental analysis, IR spectra and their structures were determined by single-crystal X-ray diffraction methods. Complexes 1-3 show similar structures containing a Sn₄O₄ ladder skeleton in which each of the exo tin atoms is bonded to the N atom of a corresponding thione-form deprotonated ligand. Complex 4 shows a mononuclear structure in which the tin atom of triphenyltin group is coordinated by the S atom of a thiol-form L4^- anion.

Full text of DOI:10.1016/j.jorganchem.2006.05.002

Journal of Organometallic Chemistry 691 (2006) 3531–3539
www.elsevier.com/locate/jorganchem
Syntheses and crystal structures of four new organotin complexes with
Schiff bases containing triazole
a
a,
a
a
a
Hai-Xia Yu , Jian-Fang Ma *, Guo-Hai Xu , Shun-Li Li , Jin Yang ,
a
b,
*
Ying-Ying Liu , Yan-Xiang Cheng
a
Department of Chemistry, Northeast Normal University, No. 5268, Renmin Street, Changchun 130024, People’s Republic of China
b
Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China
Received 23 March 2006; received in revised form 28 April 2006; accepted 2 May 2006
Available online 5 May 2006
Abstract
Four new organotin complexes, namely [(Bu2Sn)2O(EtO)(L1)]2 (1), [(Bu2Sn)2O(EtO)(L2)]2 (2), [(Bu2Sn)2O(EtO)(L3)]2 (3) and
[Ph3Sn(L4)] Æ 0.5H2O (4), were obtained by reactions of Bu2SnO and Ph3SnOH with 4-phenylideneamino-3-methyl-1,2,4-triazole-5-thi-
one (HL1), 4-furfuralideneamino-3-methyl-1,2,4-triazole-5-thione (HL2), 4-(2-thienylideneamino)-3-ethyl-1,2,4 -triazole-5-thione (HL3)
and 4-(3,5-di-t-butylsalicylideneamino)-3-ethyl-1,2,4-triazole-5-thione (HL4). Compounds 1–4 were characterized by elemental analysis,
IR spectra and their structures were determined by single-crystal X-ray diffraction methods. Complexes 1–3 show similar structures con-
taining a Sn4O4 ladder skeleton in which each of the exo tin atoms is bonded to the N atom of a corresponding thione-form deprotonated
ligand. Complex 4 shows a mononuclear structure in which the tin atom of triphenyltin group is coordinated by the S atom of a thiol-
form L4ꢀ anion.
ꢀ 2006 Elsevier B.V. All rights reserved.
Keywords: Triazole; Organotin; Schiff base
1. Introduction
form [11]. As shown in Scheme 1, this ligand can act as
monodentate mode through the sulfur atom, or bidentate
chelating mode through the sulfur and the amine nitrogen
atoms, or tridentate chelating N,S and bridging through
the endocyclic nitrogen atom, and finally l3-bridging
mode [11,12]. Based on the biological activity and versa-
tile bonding modes of HAATT, further functionalization
of the amine or R groups can modify the activity of the
compound. The syntheses and the coordination chemistry
of the Schiff bases condensed from 3-alkyl-4-amino-1,2,4-
triazole-5-thione and various aldehydes have been studied,
and the crystal structures of several Schiff bases were
determined [13], but there have been no reports on the
crystal structures of the metal complexes. In this work,
four Schiff bases that differ in the identity of the alkyl
R group on the triazole ring and the R0 group on the
amine substituent have been synthesized (Scheme 2),
and their reactions with organotin have been studied.
The organotin complexes have been of great interest
for many years because of their versatile bonding modes
and biological perspective [1,2] as well as their industrial
and agricultural applications [3,4]. A variety of organotin
complexes are now known to show antitumor activity [5]
and some others are well established for use as fungicides,
biocides and pesticides [6–8]. Triazole derivatives also dis-
play a broad range of biological activity, showing poten-
tial applications as antitumor, antibacterial, antifungal
and antiviral agents [9,10]. One representative compound
for this class is 3-alkyl-4-amino-1,2,4-triazole-5-thione
(HAATT) which presents in solution thione–thiol tautom-
erism whereas in the solid state it presents only the thione
*
Corresponding authors.
E-mail address: jianfangma@yahoo.com.cn (J.-F. Ma).
0022-328X/$ - see front matter ꢀ 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2006.05.002

3532
H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
Scheme 1.
Scheme 2.
Four novel diorganotin and triorganotin complexes were
obtained. All complexes were characterized by elemental
analysis, IR spectra and X-ray crystallography.
2.1.2. Synthesis of 4-amino-3-methyl-1,2,4-triazole-5-thione
[15,16]
A mixture of thiocarbohydrazide (3.18 g, 0.03 mol) in
glacial acetic acid (10 ml) was heated under reflux for 4 h.
The left glacial acetic acid was removed. After cooling
down to room temperature, the solid product was sepa-
rated, and recrystallized from water (yield 70%).
2. Experimental
2.1. Materials and measurements
All reagents were commercially available, and were used
without further purification. Elemental analyses were car-
ried out with a Perkin–Elmer 240 elemental analyzer. The
FT-IR spectra were recorded from KBr pellets in range
4000–400 cmꢀ1 on a Mattson Alpha-Centauri spectrometer.
2.1.3. Synthesis of 4-amino-3-ethyl-1,2,4-triazole-5-thione
The synthesis procedure was the same as Section 2.1.2.
Yield 75%.
2.1.4. Synthesis of HL1, HL2, HL3 and HL4
Synthesis of HL1. Concentrated sulfuric acid (0.75 ml)
was added to a mixture of 4-amino-3-methyl -1,2,4-tria-
zole-5-thione (0.13 g, 1 mmol) and benzaldehyde (0.11 g,
1 mmol) in ethanol (20 ml). After stirring for 1 h, the yellow
2.1.1. Synthesis of thiocarbohydrazide
Thiocarbohydrazide was prepared according to the
reported procedure [14].

H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
3533
precipitate was collected by filtration, washed with ethanol,
2.2. X-ray crystallographic studies of 1, 2, 3 and 4
and dried at room temperature.
HL2, HL3 and HL4 were synthesized analogously.
Experimental details of the X-ray analyses are provided
in Table 1. Diffraction intensities for 1–4 were collected on
a Bruker Apex CCD diffractometer with graphite-mono-
2.1.5. Synthesis of organotin complexes
˚
chromated Mo Ka radiation (k = 0.71069 A). The struc-
2.1.5.1. Synthesis of [(Bu2Sn)2O(EtO)(L1)]2 (1). After
a mixture of n-Bu2SnO (248 mg, 1 mmol) and HL1
(109 mg, 0.5 mmol) in a mixed solvent of benzene
(20 ml) and ethanol (10 ml) had been heated under reflux
for 8 h, the resulting solution was filtered. Yellow crystals
of 1 were obtained by evaporating the filtrate at room
temperature. Yield 50%. Analysis: Found (Calc. for
[(Bu2Sn)2O(EtO)(L1)]2): C, 45.11 (45.19); H, 6.71 (6.77);
N, 7.56 (7.53)%.
tures were solved by direct methods using SHELXS-97 [17]
and refined with full-matrix least-squares techniques using
the SHELXL-97 [18] program within WINGX [19]. Non-hydro-
gen atoms were refined anisotropically. The hydrogen
atoms on carbon atoms were generated geometrically.
3. Results and discussion
3.1. Synthesis and spectra
2.1.5.2. Synthesis of [(Bu2Sn)2O(EtO)(L2)]2 (2). 2 was
prepared according to the method for 1 by a reaction of
n-Bu2SnO (248 mg, 1 mmol) and HL2 (104 mg, 0.5 mmol).
Yield 45%. Analysis: Found (Calc. for [(Bu2Sn)2O(EtO)-
(L2)]2): C, 42.44 (42.54); H, 6.53 (6.59); N, 7.61 (7.63)%.
When n-Bu2SnO was treated with 0.5 equiv. of HL1,
HL2 and HL3 in a mixture of benzene and ethanol (2:1),
[(Bu2Sn)2O(EtO)(L1)]2 (1), [(Bu2Sn)2O(EtO)(L2)]2 (2) and
[(Bu2Sn)2O(EtO)(L3)]2 (3) were isolated, respectively. The
suitable crystals for X-ray analysis were obtained by evap-
orating the corresponding solutions at room temperature.
[Ph3Sn(L4)] Æ 0.5H2O (4) was obtained by the reaction of
Ph3SnOH with equivalent of HL4.
Each of the IR spectra of 1, 2 and 3 shows absorption at
1254–1259 cmꢀ1 which can be attributed to NAN@C
vibration. The bands of m(NAH) occurring at about
3100 cmꢀ1 in free ligands disappear, indicating metal–
ligand bond formation through this site. The absorptions
at about 1250 cmꢀ1 can be assigned to m(C@S). Their exis-
tences also indicate that the primary bonds of the ligand to
tin atoms are through N atom on the triazole ring. The
strong absorptions at 2955 cmꢀ1 are ascribed to the vibra-
tion of –CH2– groups. In the IR spectrum of 4, the m(C@S)
vibration of HL4 in about 1250 cmꢀ1 disappears, and the
new absorption at 729 cmꢀ1 can be assigned to m(C@S),
indicating that L4ꢀ is coordinated to tin atom through sul-
fur atom via thiolate form [20].
2.1.5.3. Synthesis of [(Bu2Sn)2 O(EtO)(L3)]2 (3).
3
was also prepared according to the method for 1 by a reac-
tion of n-Bu2SnO (248 mg, 1 mmol) and HL3 (119 mg,
0.5 mmol). Crystals of 3 were obtained by recrystallization
from a mixture of petroleum ether and ethanol. Yield 53%.
Analysis: Found (Calc. for [(Bu2Sn)2O(EtO)(L3)]2): C
42.41(42.44),H 6.53(6.59), N 7.39(7.33)%.
2.1.5.4. Synthesis of [Ph3Sn(L4)] Æ 0.5H2O (4). After a
mixture of Ph3SnOH (371 mg, 1 mmol) and HL4
(359 mg, 1 mmol) in benzene was refluxed for 8 h, the
resulting yellow solution was filtered. Yellow crystals of
4 were obtained by evaporating the filtrate at room tem-
perature. Yield 62%. Analysis: Found (Calc. for [Ph3Sn-
(L4)] Æ 0.5H2O): C, 61.16 (61.85); H, 6.18 (6.03); N, 7.75
(7.80)%.
Table 1
Crystal data for compounds 1–4
1
2
3
4
Empirical formula
Formula weight
Crystal size (mm)
Crystal system
Space group
C
56H100N8O4S2Sn4
C52H96N8O6S2Sn4
1468.25
0.316 · 0.184 · 0.122
Monoclinic
P21/n
12.6881(5)
15.7729(7)
17.5699(8)
90
107.642(5)
90
C54H100N8O4S4Sn4
1528.42
0.356 · 0.234 · 0.178
Monoclinic
P21/n
24.389(4)
11.519(2)
25.179(4)
90
C37H43N4O1.5SSn
718.50
0.289 · 0.248 · 0.146
Triclinic
1488.32
0.278 · 0.185 · 0.068
Monoclinic
P21/n
12.6661(5)
15.9642(7)
17.8316(8)
90
106.441(1)
90
3458.2(3)
2
ꢀ
P1
˚
a (A)
9.397(5)
13.252(5)
14.815(5)
83.351(5)
82.450(5)
80.757(5)
1797(1)
2
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
90.503(2)
90
7074(2)
3
˚
Volume (A )
3351(2)
2
0.0599
Z
Rint
4
0.0629
0.0826
0.0535
R1 [I > 2r(I)]
wR2 (all data)
0.0336
0.0661
0.0339
0.0686
0.0851
0.2654
0.0539
0.1469

3534
H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
3.2. Crystal structures
1–3 are the first examples of this type containing amido
and ethoxide groups.
Selected bond lengths and bond angles for 1–4 are given
in Table 2. The structures of 1–3 are shown in Figs. 1–3,
respectively. Compounds 1–3 possess similar Sn4O4 ladder
structures. The ladder structure contains two kinds of Sn
atoms. The exo Sn center shows a five-coordinate trigonal
bipyramidal geometry composed of two C atoms, one
l3-O2ꢀ atom, one l2-EtOꢀ group and one N atom from
Lꢀ anion. The EtOꢀ and the N of Lꢀ occupy the axial sites
of the distorted trigonal bipyramidal geometry. For the
endo Sn center, there is a weak interaction between another
N atom on the triazole ring and the endo tin atom. So the
endo Sn atom can be regarded as a six-coordinate center,
showing distorted octahedral geometry.
As shown in Fig. 4, compound 4 shows a mononuclear
structure. In contrast to compounds 1–3, L4ꢀ anion exists
in thiol form in 4, and coordinates to tin atom through
the thiol S atom not the nitrogen atom on the triazole ring.
The tin atom shows a distorted tetrahedral geometry. The
angles C(26)–Sn(1)–C(24), C(26)–Sn(1)–S(2) and C(24)–
Sn(1)–S(2) are wider than the ideal tetrahedral angle;
and C(26)–Sn(1)–C(32), C(24)–Sn(1)–C(32) and especially
C(32)–Sn(1)–S(2) are narrower than the ideal tetrahedral
angle. The deviation from the regular tetrahedral geometry
may result from steric hindrance and different electroneg-
ativities of the ligand attached to the tin atom. The Sn(1)–
˚
S(2) bond distance (2.459 A) is similar to the reported values
For compound 1, the axial–Sn–axial angle of exo Sn
atom is O(1)–Sn(1)–N(1) 159.02ꢁ. The Sn(1)–N(1) bond
for triphenyltin thiolates [27,28]. The C(34)–S(2) distance
(1.726 A) is consistent with the values in triphenyltin deriva-
˚
˚
length of 2.248 A is similar to the reported values in the
tives with thiolate ligands [29]. In addition, there exist lattice
water molecules in the structure of 4. The water and hydroxyl
group of the ligand are potential hydrogen-bonding sites.
There is an intramolecular O–Hꢁ ꢁ ꢁN hydrogen bond, and
the lattice water molecule is hydrogen-bonded to one N atom
on the triazole ring. The hydrogen bond distances are listed
in Table 3.
related compounds [21]. The distance of endo Sn(2)–
˚
N(2A) (2.837 A) is midway between the sums of the cova-
lent radii and van der Waals radii of tin and nitrogen
˚
(2.15–3.74 A) [22,23], and this interaction can be regarded
as a weak coordination bond. In addition, the C–S dis-
˚
tance of 1.675 A is similar to the reported C@S bond
length [24]. All above information shows that the primary
bond of the ligand to the tin atom is through the amido
N atom, but the sulfur atom does not coordinate to any
tin atoms.
The coordination modes of 3-alkyl-4-amino-1,2,4-tria-
zole-5-thione (HAATT) with the divalent first row transi-
tion metals Mn–Zn have been studied in detail [11,12].
HAATT tends to coordinate to the metal ion in bidentate
chelating mode via the thione and amine substituents on
the triazole ring. Since most syntheses were carried out in
acidic media, HAATT presents as neutral thione form in
the complexes. No complexes containing deprotonated
[AATT]ꢀ ligand have been reported. It is very interesting
to investigate the coordination chemistry of larger triazole
derivatives, such as the four molecules in this study, that
have organic functional groups on the amine N atom. As
shown in Scheme 2, ligand in this work (HL) presents in
solution thione–thiol tautomerism whereas in the solid
state it presents only the thione form [13]. In principle,
HL can coordinate to metal ion in neutral from (HL) or
deprotonated form (Lꢀ), and both neutral form and depro-
tonated form can exist in thiol or thione form (Schemes 2
and 4). There are various possible coordination modes
for both thiol and thione ligands (Scheme 5). Thus single
crystal structure determination is necessary to investigate
the true coordination modes of the ligands. Although the
coordination interaction between such ligands and transi-
tion metals has been studied [13], no crystal structures have
been determined. In this work, due to the basicity of
organotin reactants, ligands exist as deprotonated anions
in compounds 1–4. For compounds 1–3, Lꢀ anions exist
in thione-form. There are two possible coordination modes
for thione-form Lꢀ anions: I-a and I-b (Scheme 5). The
crystal structures reveal that Lꢀ anions coordinate to tin
atom in a monodente mode (I-a in Scheme 5). Like the
structures of free Schiff base ligands [13], in each case of
1–3 the conformation adopted by the Lꢀ ligand in the solid
For compound 2, the ligand is not substantially different
in the triazole moiety, however the amine substituent on
the triazole is different. The bond length of Sn(1)–N(3) of
˚
˚
2.259 A is slightly longer than that of 1 (2.248 A), and
the interatomic distance between Sn(2A) and N(4) is
˚
2.800 A. Like compound 1, the exo Sn atom is five-coordi-
nate, showing a distorted trigonal bipyramidal geometry
with O(2)–Sn(1)–N(3) being 159.11ꢁ.
As exhibited in Fig. 3, HL3 differs from HL1 and HL2
in having an ethyl group not methyl group on the triazole
ring and having a thienyl group on the substituted amino
group, and there are two kinds of 3 molecules in the crystal
structure. The structures of these two molecules are almost
the same with slight differences in bond lengths and bond
angles. The axial–Sn–axial angles of the exo Sn atoms are
O(1)–Sn(1)–N(4) 160.0ꢁ and O(3)–Sn(3)–N(8) 159.3ꢁ
respectively, showing the distorted trigonal bipyramidal
geometry. The Sn(exo)–N bond lengths of the two mole-
˚
˚
cules are Sn(1)–N(4) (2.227 A) and Sn(3)–N(8) (2.249 A).
The Sn(endo)–N interatomic distances are 2.928 and
˚
2.824 A, respectively. Furthermore, there are remarkable
differences between the C–S bond distances of the two mol-
˚
ecules (1.678 and 1.705 A).
Several compounds containing dimeric tetraorganodis-
tannoxane skeleton [R2Sn(l-X)OR2Sn(Y)]2 (X and
Y = univalent anions) have been reported [25]. For com-
pounds where X = OH, Cl, I or NCS; Y = OH, Cl or
EtO, their structures are shown in Scheme 3 [26]. Each of
compounds 1–3 has a similar structure, and compounds

H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
3535
Table 2
a
˚
Selected bond distance (A) and bond angles (ꢁ) for 1 and 2
Compound 1
C(9)–S(1)
1.675(4)
1.393(4)
2.155(4)
2.119(4)
2.032(2)
2.078(2)
2.248(3)
N(1)–N(2)
1.375(4)
N(3)–N(4)
C(14)–Sn(1)
C(22)–Sn(2)
O(2)–Sn(1)
O(2)–Sn(2)
N(1)–Sn(1)
C(13)–Sn(1)
C(21)–Sn(2)
O(1)–Sn(1)
O(1)–Sn(2)
Sn(2)–O(2)#1
2.104(5)
2.130(4)
2.188(2)
2.237(2)
2.115(2)
O(2)–Sn(1)–C(13)
C(13)–Sn(1)–C(14)
C(13)–Sn(1)–O(1)
O(2)–Sn(1)–N(1)
C(14)–Sn(1)–N(1)
O(2)–Sn(2)–C(22)
C(22)–Sn(2)–O(2)#1
C(22)–Sn(2)–C(21)
O(2)–Sn(2)–O(1)
O(2)#1–Sn(2)–O(1)
114.08(16)
133.22(19)
94.41(14)
84.73(10)
92.09(14)
108.08(13)
101.23(13)
138.82(17)
72.41(8)
O(2)–Sn(1)–C(14)
O(2)–Sn(1)–O(1)
C(14)–Sn(1)–O(1)
C(13)–Sn(1)–N(1)
O(1)–Sn(1)–N(1)
O(2)–Sn(2)–O(2)#1
O(2)–Sn(2)–C(21)
O(2)#1–Sn(2)–C(21)
C(22)–Sn(2)–O(1)
C(21)–Sn(2)–O(1)
112.59(14)
74.31(9)
94.96(13)
95.09(15)
159.02(10)
74.38(9)
111.47(13)
99.96(13)
89.10(13)
92.08(13)
146.79(9)
Compound 2
S(1)–C(6)
N(3)–N(4)
Sn(1)–C(13)
Sn(2)–C(21)
Sn(1)–O(2)
Sn(2)–O(3)#1
Sn(1)–N(3)
1.668(5)
1.387(4)
2.128(5)
2.118(4)
2.184(3)
2.112(2)
2.259(3)
N(2)–N(1)
Sn(1)–C(12)
Sn(2)–C(20)
Sn(1)–O(3)
Sn(2)–O(3)
Sn(2)–O(2)
1.390(4)
2.093(5)
2.102(5)
2.023(2)
2.087(2)
2.246(3)
O(3)–Sn(2)–C(20)
C(20)–Sn(2)–O(3)#1
C(20)–Sn(2)–C(21)
O(3)–Sn(2)–O(2)
O(3)#1–Sn(2)–O(2)
O(3)–Sn(1)–C(12)
C(12)–Sn(1)–C(13)
C(12)–Sn(1)–O(2)
O(3)–Sn(1)–N(3)
C(13)–Sn(1)–N(3)
106.70(15)
101.91(16)
139.51(19)
71.14(9)
146.75(9)
114.91(19)
131.9(2)
94.10(17)
84.48(12)
92.28(16)
O(3)–Sn(2)–O(3)#1
O(3)–Sn(2)–C(21)
O(3)#1–Sn(2)–C(21)
C(20)–Sn(2)–O(2)
C(21)–Sn(2)–O(2)
O(3)–Sn(1)–C(13)
O(3)–Sn(1)–O(2)
C(13)–Sn(1)–O(2)
C(12)–Sn(1)–N(3)
O(2)–Sn(1)–N(3)
74.62(10)
111.57(15)
100.44(14)
88.13(16)
91.30(15)
113.04(14)
74.66(10)
94.87(15)
95.66(18)
159.11(12)
Compound 3
S(2)–C(6)
1.678(12)
2.124(12)
2.136(12)
2.097(12)
2.121(12)
2.017(7)
2.182(8)
2.060(7)
2.138(7)
2.196(7)
1.402(12)
1.407(12)
2.227(9)
S(4)–C(33)
Sn(3)–C(40)
Sn(3)–C(41)
Sn(4)–C(49)
Sn(4)–C(48)
Sn(3)–O(4)
Sn(3)–O(3)
Sn(4)–O(4)
Sn(4)–O(3)
Sn(4)–O(4)#2
N(5)–N(6)
N(7)–N(8)
Sn(3)–N(8)
1.705(12)
2.124(12)
2.151(13)
2.096(13)
2.133(13)
2.017(7)
2.172(8)
2.063(7)
2.231(9)
2.131(7)
1.392(13)
1.392(13)
2.249(9)
Sn(1)–C(13)
Sn(1)–C(14)
Sn(2)–C(22)
Sn(2)–C(21)
Sn(1)–O(2)
Sn(1)–O(1)
Sn(2)–O(2)
Sn(2)–O(2)#1
Sn(2)–O(1)
N(1)–N(2)
N(3)–N(4)
Sn(1)–N(4)
O(2)–Sn(1)–C(13)
O(2)–Sn(1)–C(14)
C(13)–Sn(1)–C(14)
O(2)–Sn(1)–O(1)
C(13)–Sn(1)–O(1)
C(14)–Sn(1)–O(1)
O(2)–Sn(1)–N(4)
C(13)–Sn(1)–N(4)
C(14)–Sn(1)–N(4)
O(1)–Sn(1)–N(4)
O(2)–Sn(2)–C(22)
114.1(4)
115.8(4)
129.5(5)
72.8(3)
95.3(4)
92.5(4)
87.2(3)
93.4(4)
95.7(5)
160.0(3)
112.3(5)
O(4)–Sn(3)–C(40)
O(4)–Sn(3)–C(41)
C(40)–Sn(3)–C(41)
O(4)–Sn(3)–O(3)
C(40)–Sn(3)–O(3)
C(41)–Sn(3)–O(3)
O(4)–Sn(3)–N(8)
C(40)–Sn(3)–N(8)
C(41)–Sn(3)–N(8)
O(3)–Sn(3)–N(8)
O(4)–Sn(4)–C(49)
114.7(4)
115.5(5)
129.5(5)
73.9(3)
95.2(5)
93.4(4)
85.4(3)
93.7(5)
95.3(5)
159.3(3)
107.1(6)
(continued on next page)

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H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
Table 2 (continued)
O(2)–Sn(2)–C(21)
C(22)–Sn(2)–C(21)
O(2)–Sn(2)–O(2)#1
C(22)–Sn(2)–O(2)#1
C(21)–Sn(2)–O(2)#1
O(2)–Sn(2)–O(1)
C(22)–Sn(2)–O(1)
C(21)–Sn(2)–O(1)
O(2)#1–Sn(2)–O(1)
111.9(4)
135.3(6)
74.6(3)
100.2(5)
97.3(4)
71.7(3)
93.8(5)
93.8(4)
146.3(3)
O(4)–Sn(4)–O(4)#2
C(49)–Sn(4)–O(4)#2
O(4)–Sn(4)–C(48)
C(49)–Sn(4)–C(48)
O(4)#2–Sn(4)–C(48)
O(4)–Sn(4)–O(3)
C(49)–Sn(4)–O(3)
O(4)#2–Sn(4)–O(3)
C(48)–Sn(4)–O(3)
74.6(3)
99.5(5)
111.2(5)
140.5(7)
99.3(4)
71.8(3)
92.6(5)
146.2(3)
90.6(4)
Compound 4
C(34)–S(2)
N(3)–N(4)
S(2)–Sn(1)
C(26)–Sn(1)
1.726(6)
N(1)–N(2)
O(5)–H(5)
C(24)–Sn(1)
C(32)–Sn(1)
1.403(6)
1.398(6)
2.4592(17)
2.110(6)
0.893(10)
2.121(6)
2.142(6)
C(26)–Sn(1)–C(24)
C(24)–Sn(1)–C(32)
C(24)–Sn(1)–S(2)
115.4(2)
108.9(3)
110.18(16)
C(26)–Sn(1)–C(32)
C(26)–Sn(1)–S(2)
C(32)–Sn(1)–S(2)
108.3(3)
114.28(15)
98.34(18)
a
Symmetry operations: for 1 (#1) 1 ꢀ x, ꢀy, 2 ꢀ z; for 2 (#1) 1 ꢀ x, ꢀy, 1 ꢀ z; for 3 (#1) 1 ꢀ x, ꢀy, ꢀz; (#2) 2 ꢀ x, 1 ꢀ y, ꢀz.
Fig. 1. Molecular structure of 1.
Fig. 2. Molecular structure of 2.

H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
3537
Fig. 3. Molecular structure of 3.
Table 3
Hydrogen-bond geometries for compound 4a
˚
˚
˚
D–Hꢁ ꢁ ꢁA
D–H (A)
Hꢁ ꢁ ꢁA (A)
Dꢁ ꢁ ꢁA (A)
\D–Hꢁ ꢁ ꢁA (ꢁ)
OW1–H(1A)
ꢁ ꢁ ꢁN(2)#1
O(5)–H(5)
ꢁ ꢁ ꢁN(4)
0.850(10)
0.893(10)
2.02(4)
2.810(14)
155(9)
2.09(8)
2.588(6)
114(7)
a
Symmetry operations: (#1) ꢀx + 1, ꢀy, ꢀz.
state places the organic group attached to N atom on the
same side of the N–N bond as the S atom. Thus the C atom
is blocking the N from chelating a metal ion together with
the S atom, and the chelating mode (I-b in Scheme 5) which
exists in the metal complexes of HAATT [11,12] cannot
occur for 1–3. The ability of Lꢀ anions to adopt conforma-
tions more suitable to chelating modes depends in part on
the ease of rotation about the N–N bond. In contrast with
1–3, L4ꢀ anion adopts a thiol form not a thione form in
compound 4. Thiol form L4ꢀ anion may coordinate to
metal ion in two modes: II-a and II-b in Scheme 5. Base
on the same steric hindrance for compound 1–3, L4ꢀ anion
coordinates to tin atom in the monodentate mode (II-a in
Scheme 5) in 4.
Scheme 3.
From the structures of 1–3, it can be seen that the
substituted group at the amino position has little influence
on the structures of the complexes. In 1–3, the tin atom is
coordinated by the N atom on the triazole ring; while the
tin atom of 4 is coordinated by the S atom. This may result
from the steric repulsion of three phenyl groups which is
strong enough to prevent the ligand from coordinating to
tin atom through the N atom on the triazole ring. The
bulkier the organic groups of the organotin are, the more
difficult the coordination through the N atom on the tria-
zole ring is.
Fig. 4. The structure of 4.

3538
H.-X. Yu et al. / Journal of Organometallic Chemistry 691 (2006) 3531–3539
Scheme 4. Thiol-thione tautomerism of Lꢀ anions.
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We thank the National Natural Science Foundation of
China (No. 20471014), Program for New Century Excel-
lent Talents in Chinese University (NCET-05-0320), the
Fok Ying Tung Education Foundation and the Natural
Science Foundation of Jilin province (China) for support.
Appendix A. Supplementary material
[18] G.M. Sheldrick, SHELXL-97,
A Programs for Crystal Structure
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Analysis, University of Glasgow, Glasgow, UK, 1988.
CCDC 602386–602389 contain the supplementary crys-
tallographic data for this paper. These data can be
obtained free of charge via www.ccdc.cam.ac.uk/conts/
retrieving.html (or from the Cambridge Crystallographic
Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK
(fax: +44 1223 336033). Supplementary data associated
with this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2006.05.002.
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