Syntheses, characterizations and crystal structures of new organoantimony(V) complexes with heterocyclic (S, N) ligand

Article abstract of DOI:10.1016/j.jorganchem.2006.01.049

Eight new organoantimony(V) complexes with 1-phenyl-1H-tetrazole-5-thiol [L¹H] and 2,5-dimercapto-4-phenyl-1,3,4-thiodiazole [L²H] of the type R_nSbL_{5 - n} (L = L¹: n = 4, R = n-Bu 1, Ph 2, n = 3, R = Me 3, Ph 4; L = L²: n = 4, R = n-Bu 5, Ph 6, n = 3, R = Me 7, Ph 8) have been synthesized. All the complexes 1-8 have been characterized by elemental, FT-IR, ¹H and ¹³C NMR analyses. Among them complexes 2, 6 and 8 have also been confirmed by X-ray crystallography. The structure analyses show that the antimony atoms in complexes 2 and 6 display a trigonal bipyramid geometry, while it displays a distorted capped trigonal prism in complex 8 with two intramolecular Sb?N weak interactions. Furthermore, the supramolecular structure of 2 has been found to consist of one-dimensional linear molecular chain built up by intermolecular C-H?N weak hydrogen bonds, while a macrocyclic dimer has been found in complex 6 linked by intermolecular C-H?S weak hydrogen bonds with head-to-tail arrangement. Interestingly, one-dimensional helical chain is recognized in complex 8, which is connected by intermolecular C-H?S weak hydrogen bonds.

Full text of DOI:10.1016/j.jorganchem.2006.01.049

Journal of Organometallic Chemistry 691 (2006) 2567–2574
www.elsevier.com/locate/jorganchem
Syntheses, characterizations and crystal structures of new
organoantimony(V) complexes with heterocyclic (S,N) ligand
a,b,
a
a
a
Chunlin Ma
*, Qingfu Zhang , Jiafeng Sun , Rufen Zhang
a
Department of Chemistry, Liaocheng University, Liaocheng, Shandong 252059, PR China
b
Department of Chemistry, Taishan University, Taian 271021, PR China
Received 26 December 2005; received in revised form 20 January 2006; accepted 26 January 2006
Available online 3 March 2006
Abstract
Eight new organoantimony(V) complexes with 1-phenyl-1H-tetrazole-5-thiol [L1H] and 2,5-dimercapto-4-phenyl-1,3,4-thiodiazole
[L2H] of the type RnSbL5 À n (L = L1: n = 4, R = n-Bu 1, Ph 2, n = 3, R = Me 3, Ph 4; L = L2: n = 4, R = n-Bu 5, Ph 6, n = 3,
R = Me 7, Ph 8) have been synthesized. All the complexes 1–8 have been characterized by elemental, FT-IR, 1H and 13C NMR analyses.
Among them complexes 2, 6 and 8 have also been confirmed by X-ray crystallography. The structure analyses show that the antimony
atoms in complexes 2 and 6 display a trigonal bipyramid geometry, while it displays a distorted capped trigonal prism in complex 8 with
two intramolecular SbÁ Á ÁN weak interactions. Furthermore, the supramolecular structure of 2 has been found to consist of one-dimen-
sional linear molecular chain built up by intermolecular C–HÁ Á ÁN weak hydrogen bonds, while a macrocyclic dimer has been found in
complex 6 linked by intermolecular C–HÁ Á ÁS weak hydrogen bonds with head-to-tail arrangement. Interestingly, one-dimensional helical
chain is recognized in complex 8, which is connected by intermolecular C–HÁ Á ÁS weak hydrogen bonds.
ꢀ 2006 Elsevier B.V. All rights reserved.
Keywords: 1-Phenyl-1H-tetrazole-5-thiol; 2,5-Dimercapto-4-phenyl-1,3,4-thiodiazole; Organoantimony(V); Crystal structure; Weak hydrogen bond
1. Introduction
The two ligands are interesting because both of them are
derived from heterocyclic thiones that contain at least one
deprotonated heterocyclic thioamide group (N–C–S)À and
can act as monodentate, chelating and bridging ligands,
which has been extensively studied in the field of transi-
tion-metal coordination chemistry [6]. In our previous
work, we have studied the detailed coordination chemistry
of this type of ligands in organotin and organongermanium
complexes, the structure analyses revealed that the coordi-
nation mode of these ligands varied dramatically according
to distinct R groups of the precursor RnMCl4 À n (M = Sn,
Ge) [7]. As regards the organoantimony(V) compounds,
however, the situation is rather ambiguous, since no
X-ray crystallography have authenticated organoanti-
mony(V) compounds with heterocyclic thiones so far.
From a theoretical point of view, we think it is necessary
to do an initial probe in the coordination chemistry of
organoantimony(V) complexes with heterocyclic (S,N)
ligands, thus we report here some details of the syntheses
Metal-based drugs have been increasingly researched
due to their certain advantages over purely organic com-
pounds in drug therapy [1–3]. Among them, antimony
complexes have been reported with good cytotoxicity and
antitumor activities [3], especially Takahashi et al. have
reported some antimony complexes can affect the repair
of DNA-double strand break [3c]. However, until now
most of the studies have been focused on the inorganic
antimony and organoantimony(III) complexes [4], few
organoantimony(V) complexes have been reported [5]. To
fill the gap, we selected two interesting heterocyclic ligands
– 1-phenyl-1H-tetrazole-5-thiol and 2,5-dimercapto-4-phe-
nyl-1,3,4-thiodiazole – to react with organoantimony(V)
compounds.
*
Corresponding author. Tel.: +86 635 8238121; fax: +86 635 8238274.
E-mail address: macl@lctu.edu.cn (C. Ma).
0022-328X/$ - see front matter ꢀ 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2006.01.049

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C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
of a series of organoantimony(V) complexes of the type
RnSbL5 À n (L = L1: n = 4, R = n-Bu 1, Ph 2; n = 3,
R = Me 3, Ph 4; L = L2: n = 4, R = n-Bu 5, Ph 6; n = 3,
R = Me 7, Ph 8) and characterize them by elemental, IR
and 1H and 13C NMR analyses. X-ray crystallography
analyses of the complexes 2, 6 and 8 have also been given
in present paper.
NMR (CDCl3): d 7.78 (d, 8H, o-Ph–Sb), 7.52–7.44 (m,
23H, m,p-Ph–Sb, o,m,p-C6H5–N) 7.28 (s, 6H, C6H6) ppm.
13C NMR (CDCl3): 156.0 (C–S), 135.2 (i-C6H5–N), 135.0
(i-Ph–Sb), 134.8 (m-Ph–Sb), 129.0 (m-Ph–N), 128.8 (p-
C6H5–N), 128.4 (p-Ph–Sb), 127.9 (o-Ph–Sb), 124.5 (o-Ph–
N).
2.2.3. Me3Sb[S(C7H5N4)]2 (3)
2. Experimental
Complex 3 was prepared in the same way of 1, by adding
trimethylantimony dichloride (0.119 g. 0.5 mmol) to the 1-
phenyl-1H-tetrazole-5-thiol (0.178 g, 1 mmol) and sodium
ethoxide (0.068 g, 1 mmol) in benzene (20 ml). Yield: 85%;
m.p. 178–180 ꢁC. Anal. Calc. for C17H19N8S2Sb: C, 39.17;
H, 3.67; N, 21.50; S, 12.30. Found: C, 39.20; H, 3.66; N,
21.55; S, 12.27%. IR (KBr, cmÀ1): 3028, 2925, 2856, 1573,
2.1. Materials and measurements
All reagents and solvents were purchased commercially
and used without further purification unless otherwise
noted. The melting points were obtained with Kofler micro
melting point apparatus and were uncorrected. Infrared-
spectra were recorded on a Nicolet-460 spectrophotometer
1
977, 690, 478, 428, 352. H NMR (CDCl3): d 7.60 (d, 2H,
o-Ph–N), 7.45 (m, 3H, m,p-Ph–N), 1.02 (s, 9H, Me–Sb)
ppm. 13C NMR (CDCl3): 156.5 (C–S), 134.3 (i-C6H5–N),
129.6 (p-C6H5–N), 129.4 (m-C6H5–N), 124.5 (o-C6H5–N),
8.8 (Me–Sb).
using KBr discs and sodium chloride optics. H and 13C
1
NMR spectra were recorded on a Bruker AMX-300 spec-
trometer operating at 300 and 75.3 MHz, respectively.
The chemical shifts were reported in ppm with respect to
the references and were stated relative to tetramethylsilane
(TMS) for 1H and 13C NMR. Elemental analyses were per-
formed with a PE-2400II apparatus.
2.2.4. Ph3Sb[S(C7H5N4)]2 (4)
Complex 4 was prepared in the same way of 1, by adding
triphenylantimony dichloride (0.212 g. 0.5 mmol) to the 1-
phenyl-1H-tetrazole-5-thiol (0.178 g, 1 mmol) and sodium
ethoxide (0.068 g, 1 mmol) in benzene (20 ml). Yield: 89%;
m.p. 188–190 ꢁC. Anal. Calc. for C32H25N8S2Sb: C, 54.33;
H, 3.56; N, 15.84; S, 9.06. Found: C, 54.30; H, 3.60; N,
15.77; S, 9.05%. IR (KBr, cmÀ1): 3025, 2930, 2858, 1580,
2.2. Syntheses of the complexes 1–8
2.2.1. (n-Bu)4Sb[S(C7H5N4)] (1)
The reaction was carried out under nitrogen atmo-
sphere. The 1-phenyl-1H-tetrazole-5-thiol (0.178 g,
1 mmol) and sodium ethoxide (0.068 g, 1 mmol) were
added to the solution of absolute benzene (20 ml) in a
Schlenk flask and stirred for 0.5 h. The tetra-n-butylanti-
mony bromide (0.430 g, 1 mmol) was then added to the
reactor, the reaction mixture was stirred for 12 h at 40 ꢁC
and then filtrated. The filtered solution was gradually
removed by evaporation under vacuum until the solid
product was obtained. Yield: 82%; m.p. 198–200 ꢁC. Anal.
Calc. for C23H41N4SSb: C, 52.38; H, 7.84; N, 10.62; S, 6.08.
Found: C, 52.30; H, 7.85; N, 10.65; S, 6.00%. IR (KBr,
cmÀ1): 3035, 2930, 2855, 1605, 973, 690, 475, 365. 1H
NMR (CDCl3): 7.68 (d, 2H, o-Ph–N), 7.48 (m, 3H, m,p-
Ph–N), 1.58–1.35 (m, 24H, CH2CH2CH2), 0.85 (d, 12H,
CH3(CH2)3) ppm. 13C NMR (CDCl3): 156.8 (C–S), 134.7
(i-C6H5–N), 129.5 (p-C6H5–N), 129.2 (m-C6H5–N), 124.1
(o-C6H5–N), 27.8 (b-C), 26.0 (c-C), 16.5 (a-C), 12.8 (d-C).
1
970, 688, 482, 432, 368. H NMR (CDCl3): d 7.72 (d, 6H,
o-Ph–Sb), 7.50 (d, 4H, o-Ph–N), 7.48–7.33 (m, 24H, m,p-
Ph–Sb, m,p-C6H5–N) ppm. 13C NMR (CDCl3): 156.8 (C–
S), 138.0(i-Ph–N), 135.5 (i-Ph–Sb), 134.3 (m-Ph–Sb),
129.3 (m-Ph–N), 128.0 (p-Ph–N), 126.8 (p-Ph–Sb), 125.5
(o-Ph–N).
2.2.5. (n-Bu)4Sb[S(C8H5N2S2)] (5)
Complex 5 was prepared in the same way of 1, by add-
ing tetra-n-butylantimony bromide (0.430 g, 1 mmol) to
potassium salt of 2,5-dimercapto-4-phenyl-1,3,4-thiodiaz-
ole (0.264 g, 1 mmol) in benzene (20 ml). Yield: 83%;
m.p. 195–197 ꢁC. Anal. Calc. for C24H41N2S3Sb: C,
50.08; H, 7.18; N, 4.87; S, 16.71. Found: C, 50.12; H,
7.20; N, 4.83; S, 16.70. IR (KBr, cmÀ1): 3015, 2975, 2868,
1
1608, 1252, 977, 698, 480, 368. H NMR (CDCl3): d 7.65
(d, 2H, o-Ph–N), 7.42 (m, 3H, m,p-C6H5–N), 1.75–1.42
(m, 24H, CH2CH2CH2) 0.85 (d, 12H,CH3(CH2)3) ppm.
13C NMR (CDCl3): d 187.3 (C–S), 158.3 (C@S), 138.4 (i-
Ph–N), 128.5 (m,p-Ph–N), 125.8 (o-Ph), 28.5 (b-C), 26.8
(c-C), 16.1 (a-C), 13.4 (d-C).
2.2.2. Ph4Sb[S(C7H5N4)] Æ C6H6 (2)
Complex 2 was prepared in the same way of 1, by add-
ing tetraphenylantimony bromide (0.510 g, 1 mmol) to the
1-phenyl-1H-tetrazole-5-thiol (0.178 g, 1 mmol) and
sodium ethoxide (0.068 g, 1 mmol) in benzene (20 ml). Buff
crystals of 2 suitable for X-ray diffraction were obtained
from mother liquid. Yield: 87%; m.p. 210–212 ꢁC. Anal.
Calc. for C37H31N4SSb: C, 64.83; H, 4.56; N, 8.17; S,
4.68. Found: C, 64.85; H, 4.52; N, 8.23; S, 4.70%. IR
2.2.6. Ph4Sb[S(C8H5N2S2)] (6)
Complex 6 was prepared in the same way of 1, by add-
ing tetraphenylantimony bromide (0.510 g, 1 mmol) to
potassium salt of 2,5-dimercapto-4-phenyl-1,3,4-thiodiaz-
ole (0.264 g, 1 mmol) in benzene (20 ml). Yellow crystals
of 6 suitable for X-ray diffraction were obtained from
(KBr, cmÀ1): 3030, 2928, 2852, 1600, 975, 484, 358. H
1

C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
2569
benzene. Yield: 89%; m.p. 205–207 ꢁC. Anal. Calc. for
C32H25N2S3Sb: C, 58.63; H, 3.84; N, 4.27; S, 14.67. Found:
C, 58.68; H, 3.88; N, 4.25; S, 14.60%. IR (KBr, cmÀ1):
3058, 1593, 1246, 968, 488, 371. 1H NMR (CDCl3): d
7.68 (d, 8H, o-Ph–Sb), 7.42–7.28 (m, 17H, m,p-Ph–Sb,
o,m,p-C6H5–N) ppm. 13C NMR (CDCl3): d 186.8 (C–S),
157.8 (C@S), 137.6 (i-Ph–N), 136.5 (i-Ph–Sb), 136.2 (m-
Ph–Sb), 130.0 (m-Ph–N), 128.9(p-Ph–N), 128.4 (p-Ph–Sb),
127.9 (o-Ph–Sb), 125.5 (o-Ph–N).
obtained from hexane/dichloromethane; m.p. 195–197 ꢁC.
Anal. Calc. for C34H25N4S6Sb: C, 50.81; H, 3.14; N,
6.97; S, 23.94. Found: C, 50.85; H, 3.10; N, 6.95; S,
23.90%. IR (KBr, cmÀ1): 3050, 1581, 1248, 973, 678, 472,
438, 355. 1H NMR (CDCl3): d 7.78 (d, 6H, o-Ph–Sb),
7.59 (d, 4H, o-Ph–N), 7.52–7.38 (m, 24H, m,p-Ph–Sb,
m,p-C6H5–N) ppm. 13C NMR (CDCl3): d 185.6 (C–S),
158.1 (C@S), 138.2 (i-Ph–N), 135.9 (i-Ph–Sb), 134.6 (m-
Ph–Sb), 129.0 (m-Ph–N), 128.2 (p-Ph–N), 127.0 (p-Ph–
Sb), 125.8 (o-Ph–N).
2.2.7. Me3Sb[S(C8H5N2S2)]2 (7)
Complex 7 was prepared in the same way of 1, by add-
ing trimethylantimony dichloride (0.119 g. 0.5 mmol) to
potassium salt of 2,5-dimercapto-4-phenyl-1,3,4-thiodiaz-
ole (0.264 g, 1 mmol) in benzene (20 ml). Yield: 88%;
m.p. 168–170 ꢁC. Anal. Calc. for C19H19N4S6Sb: C,
36.95; H, 3.10; N, 9.07; S, 31.15. Found: C, 36.90; H,
3.15; N, 9.10; S, 31.10%. IR (KBr, cmÀ1): 3060, 1578,
2.3. X-ray crystallographic studies
Crystals were mounted in Lindemann capillaries under
nitrogen. All X-ray crystallographic data were collected
on a Bruker SMART CCD 1000 diffractometer with graph-
˚
ite monochromated Mo Ka radiation (k = 0.71073 A) at
298 (2) K. A semi-empirical absorption correction was
applied to the data. The structure was solved by direct
methods using SHELXS-97 and refined against F2 by full-
matrix least squares using SHELXL-97. Hydrogen atoms
were placed in calculated positions. Crystal data and exper-
imental details of the structure determinations are listed in
Table 1.
1
1256, 982, 688, 478, 425, 362. H NMR (CDCl3): d 7.70
(d, 6H, o-Ph–N), 7.45 (m, 6H, m,p-C6H5–N), 1.05 (s, 9H,
Me–Sb) ppm. 13C NMR (CDCl3): d 187.0 (C–S), 158.0
(C@S), 138.2 (i-Ph–N), 129.4 (m,p-Ph–N), 125.5 (o-Ph),
8.5 (Me–Sb).
2.2.8. Ph3Sb[S(C8H5N2S2)]2 (8)
Complex 8 was prepared in the same way of 1, by add-
ing triphenylantimony dichloride (0.212 g. 0.5 mmol) to
potassium salt of 2,5-dimercapto-4-phenyl-1,3,4-thiodiaz-
ole (0.264 g, 1 mmol) in benzene (20 ml). Yield: 90%. Yel-
low crystals of 8 suitable for X-ray diffraction were
3. Results and discussion
3.1. Syntheses of the complexes 1–8
The synthesis procedure is given in Scheme 1.
Table 1
Crystal and refinement data for complexes 2, 6 and 8
Complex
2
6
8
Empirical formula
Formula weight
Crystal system
Space group
C
685.47
Triclinic
37H31N4SSb
C32H25N2S3Sb
655.47
Triclinic
P21/c
C34H25N4S6Sb
803.69
Monoclinic
P21/c
ꢀ
P1
Unit cell dimensions
˚
a (A)
11.4791(19)
12.118(2)
13.437(2)
77.441(2)
66.304(2)
77.166(2)
1651.5(5)
2
16.652(4)
19.537(4)
18.371(4)
90
104.944(4)
90
5774(2)
8
1.508
10.143(3)
8.953(3)
37.825(3)
90
94.166(2)
90
3426.1(15)
4
1.558
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
Volume (A )
Z
Dcal (Mg mÀ3
)
1.378
Crystal size (mm)
F(000)
Absorption coefficient (mmÀ1
Data/restraints/parameters
h Range for data collection (ꢁ)
Goodness-of-fit
0.45 · 0.38 · 0.22
696
0.929
5765/0/388
1.67–25.03
1.000
0.39 · 0.22 · 0.13
2640
1.197
10163/0/685
1.80–25.02
1.024
0.43 · 0.38 · 0.22
1616
1.202
6039/0/406
2.16–25.03
1.001
)
Final R indices [I > 2r (I)]
R1 = 0.0284
wR2 = 0.0659
R1 = 0.0382
wR2 = 0.0730
0.645 and À0.371
R1 = 0.0447
wR2 = 0.0739
R1 = 0.1138
wR2 = 0.0987
0.825 and À0.751
0.0472
0.0992
0.0841
0.1135
R indices (all data)
À3
˚
Largest diff. peak and hole (e A
)
0.667 and À0.479

2570
C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
R
R
N
N
N
R4SbBr
(R = n-Bu 1, Ph 2)
(R = Me 3, Ph 4)
S
Sb
R
R
N
Ph
N
N
+
SH
EtONa
N
R
R
S
N
N
N
R3SbCl2
N
N
Sb
R
Ph
N
N
S
N
N
Ph
Ph
Ph
S
R
R
N
N
R4SbBr
(R = n-Bu 5, Ph 6)
(R = Me 7, Ph 8)
Ph
S
S
Sb R
R
S
N
N
SK
Ph
S
Ph
R
S
R
S
R3SbCl2
N
N
N
N
Sb
S
S
S
S
R
Scheme 1.
3.2. IR spectroscopic studies of the complexes 1–8
in complexes 2, 4, 6 and 8 7.28–7.78 ppm, and those of
methyl or methylene connected directly with antimony in
complexes 1, 3, 5 and 7, 1.02–1.75 ppm, upfield shift as
compared with those of their corresponding precursors,
indicating there may exist novel coordination of the ligand
to antimony atom for all the eight complexes 1–8. Signals
for the other groups appear at the same position as in
the ligands.
The structural changes occurring in ligands upon depro-
tonation and coordination to the Sb atom should be
reflected by the changes in the 13C NMR spectra of com-
plex 1–8. If the ligands chelate Sb through thiolate form,
C–S should be further low frequency in the spectra of all
complexes compared with those in free ligands. As shown
above, the chemical shifts in all complexes 1–8 are down-
shifted about 10 ppm compared with the free ligand, indi-
cating that the ligands involved in these complexes act as
thiolate form. All the above analyses are also confirmed
by crystal structure of complex 2, 6 and 8.
The explicit feature in the IR spectra of the eight com-
plexes 1–8 is the absence of the band in the region 2550–
2430 cmÀ1 (for L1H) and 2530–2420 cmÀ1 (for L2H), which
appear in the free ligands as the –SH vibration, indicating
metal–ligand bond formation through this site. In the far-
IR spectra, the absorption around 360 cmÀ1 region for all
complexes 1–8, which is absent in the spectra of the ligands,
may be assigned to Sb–S stretching mode of the vibration
[8] and these data further supports the formation of Sb–S
bond in complexes 1–8. In addition, the Sb–C absorption
values are found between 472 and 488 cmÀ1 in all the com-
plexes, which are consistent with that reported in other
organoantimony complexes [9,10].
It is worthy to note that besides the absorption region
belonging to Sb–S, there is another weak band at about
430 cmÀ1 in complexes 3, 4, 7 and 8 that can be attributed
to SbÁ Á ÁN vibration according to the literature [11,12]. Fur-
thermore, the absorption band of C@N in complexes 3, 4, 7
and 8 all shift about 20 cmÀ1 towards high-frequency com-
pared with those of complexes 1, 2, 5 and 6, which also
prove that there exist the weak coordination from nitrogen
atom of the ligands to antimony atoms in complexes 3, 4, 7
and 8. As a result, the probable geometry for complexes 3,
4, 7 and 8 can be described as a capped trigonal prism. The
following crystal structure of complex 8 well supports such
a conclusion.
3.4. Crystal structures of complexes 2, 6 and 8
Molecular and supramolecular structures of complexes
2, 6 and 8 and are shown in Figs. 1–6, respectively; and
the selected bond lengths and angles for complexes 2, 6
and 8 and are given in Tables 2–4, respectively.
3.4.1. Ph4Sb[S(C7H5N4)] Æ C6H6 and
Ph4Sb[S(C8H5N2S2)]
1
3.3. H and 13C NMR data of the complexes 1–8
For complex 2, the component Ph4Sb[S(C7H5N4)] co-
crystallizes with a benzene molecule but it has not been found
the obvious interaction between the Ph4Sb[S(C7H5N4)] moi-
ety and the solvent molecule. For complex 6, the asymmetric
unit contains two crystallographically independent mole-
cules A and B. Conformations of the two independent mol-
ecules are almost the same, with only little differences in bond
lengths and bond angles (see Table 3). The molecular struc-
1
The HNMR data show that the signal of the –SH pro-
ton in the spectra of the two ligands are both absent in all
of the complexes, indicating the removal of the –SH proton
and the formation of Sb–S bonds. The formation accords
well with what the IR data have revealed. Moreover, the
1H NMR chemical shifts of the phenyl group (Sb–C6H6)

C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
2571
Fig. 1. Molecular structure of complex 2, ellipsoids at 30% probability.
Fig. 2. Supramolecular structure of complex 2, showing 1D linear molecular chain linked by intermolecular C–HÁ Á ÁN weak hydrogen bonds.
Fig. 3. Molecular structure of complex 6, ellipsoids at 30% probability.
tures of complexes 2 and 6 are basically the same except for
bonding with different ligands (L1 for 2 and L2 for 6), and the
coordination environments of central antimony atoms in
both complexes are five-coordinated with a trigonal
bipyramidal geometry. Three phenyl groups occupy the
equatorial plane and the fourth phenyl group and the thiol
atom from ligand lie in axial sites. The sum of equatorial
angles are 355.52ꢁ (C8–Sb1–C14 114.26(11)ꢁ, C8–Sb1–C20
121.90(11)ꢁ, C14–Sb1–C20 119.36(11)ꢁ) in complex 2, and
356.6ꢁ (C9–Sb1–C15 112.8(3)ꢁ, C9–Sb1–C21 129.7(2)ꢁ,
C15–Sb1–C21 114.1(2)ꢁ) and 355.1ꢁ (C41–Sb2–C47 111.8(2)ꢁ,
C41–Sb2–C53 125.4(3)ꢁ, C47–Sb2–C53 117.9(3)ꢁ) in
complex 6, and the corresponding axial–Sb–axial angles
are 171.50(8)ꢁ (C26–Sb1–S1) in complex 2, and 178.59(18)ꢁ
(C27–Sb1–S2) and 179.2(2)ꢁ (C59–Sb2–S5) in complex 6,
suggesting both of them are close to the ideal trigonal

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C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
Fig. 4. Macrocyclic dimer of complex 6, showing intermolecular C–HÁ Á ÁS weak hydrogen bonds.
Fig. 5. Molecular structure of complex 8, ellipsoids at 30% probability.
˚
bipyramidal geometry. The axial Sb–C in complexes 2 and 6
and N atoms in complex 2 (3.711 A), even longer than the
˚
˚
˚
(Sb1–C26, 2.159(3) A for 2, Sb1–C27 2.179(6) A and Sb2–
van der Waals radii of Sb and N atoms (3.70 A), suggests
˚
C59 2.166(6) A for 6) are slightly larger than the average
there is no apparent intramolecular SbÁ Á ÁN interaction
˚
value of the equatorial Sb–C bond (2.111 A for 2, 2.115
found in this complex. For complex 6, although the distance
˚
˚
and 2.113 A for 6), which is consistent with that found in
between Sb and N atoms (3.388 and 3.407 A) are shorter
another five-coordinated trigonal bipyramidal organoanti-
mony complex, Ph3Sb[S2C2(CN)2] [13]. The Sb–S bond
lengths, Sb1–S1 (2.8762(8) A) for complex 2, Sb1–S2
than that found in 2, all the spectra of complex 6 show that
no apparent SbÁ Á ÁN interaction have been found, so we
can reasonably think that both the Sb atoms in complexes
2 and 6 are five-coordinated and there are no markedly dif-
ferences between their geometries.
Interestingly, there is a linear molecular chain found in
crystal lattice of complex 2 (Fig. 2), which is linked by
intermolecular C18–H18Á Á ÁN3 weak hydrogen bonds. The
˚
˚
˚
(2.8999(17) A) and Sb2–S5 (2.9248(17) A) for complex 6,
are slightly longer that found in (2-mercaptopyridine-N-
˚
oxide-O,S)-tetraphenyl-antimony ethanol solvate (2.716 A)
[14] but much shorter than the sum of van der Waals radii
˚
of Sb and S atoms, 4.05 A. The long distance between Sb

C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
2573
Table 4
Selected bond lengths (A) and angles (ꢁ) for the complex 8
˚
˚
Bond lengths (A)
Sb1–C17
Sb1–C29
Sb1–S2
2.097(5)
2.108(4)
2.6107(17)
3.291(4)
Sb1–C23
Sb1–S5
Sb1–N1
2.118(5)
2.5851(17)
3.245(4)
Sb1–N3
Bond angles (ꢁ)
C17–Sb1–C23
C23–Sb1–C29
C23–Sb1–S2
C23–Sb1–S5
C29–Sb1–S5
C17–Sb1–N1
C29–Sb1–N1
C23–Sb1–N3
S2–Sb1–N1
114.24(19)
126.14(19)
93.77(15)
94.65(15)
83.40(15)
137.48(17)
71.01(15)
69.18(16)
52.97(9)
C17–Sb1–C29
C17–Sb1–S2
C29–Sb1–S2
C17–Sb1–S5
S2–Sb1–S5
C23–Sb1–N1
C17–Sb1–N3
C29–Sb1–N3
N1–Sb1–S5
S2–Sb1–N3
119.6(2)
84.83(15)
90.07(15)
93.47(15)
171.36(5)
69.23(16)
66.02(16)
135.24(16)
129.03(9)
133.64(8)
N3–Sb1–S5
52.07(8)
N1–Sb1–N3
138.26(11)
values of C18AÁ Á ÁN3, H18AÁ Á ÁN3 and C18A–H18AÁ Á ÁN3
˚
˚
are 2.616 A, 3.412 A and 143.79ꢁ, respectively. For com-
plex 6, a pair of intermolecular C–HÁ Á ÁS (C19–H19Á Á ÁS6
and C51–H51Á Á ÁS3) weak hydrogen bonds have been rec-
Fig. 6. Supramolecular structure of complex 8, showing a helical chain
along the b-axis linked by intermolecular C–HÁ Á ÁS weak hydrogen bonds.
˚
˚
ognized (C19Á Á ÁS6 3.755 A, H19Á Á ÁS6 2.917 A, C19–
˚
˚
H19Á Á ÁS6 150.58ꢁ; C51Á Á ÁS3 3.853 A, H51Á Á ÁS3 2.936 A,
C51–H51Á Á ÁS3 168.34), which associate the two discrete
molecules into an interesting macrocyclic dimer (Fig. 4).
For complex 8, the central Sb atom is bonded by three
phenyl groups and two sulfur atoms from two
[S(C8H5N2S2)]À moiety, thus it displays a distorted trigoanl
bipyramidal geometry. Three phenyl groups occupy the
equatorial plane with a ‘‘paddle-wheel’’ model and two
ligands are in axial positions with asymmetric model to les-
sen the spatial hindrance from the bulky phenyl groups.
The sum of equatorial angles is 359.98ꢁ (C17–Sb1–C23
114.24(19)ꢁ, C17–Sb1–C29 119.6(2)ꢁ, C23–Sb1–C29
126.14(19)ꢁ), and the corresponding axial–Sb–axial is
171.36(5)ꢁ (S2–Sb1–S5). The three Sb–C bond lengths
around Sb atom in the equatorial plane show no apparent
Table 2
˚
Selected bond lengths (A) and angles (ꢁ) for the complex 2
˚
Bond lengths (A)
Sb1–C8
Sb1–C20
Sb1–S1
2.122(3)
2.114(3)
2.8762(8)
Sb1–C14
Sb1–C26
2.108(3)
2.159(3)
Bond angles (ꢁ)
C8–Sb1–C14
C14–Sb1–C20
C8–Sb1–C26
C20–Sb1–C26
C8–Sb1–S1
114.26(11)
119.36(11)
97.17(11)
97.31(11)
90.99(8)
C8–Sb1–C20
C26–Sb1–S1
C14–Sb1–C26
C14–Sb1–S1
C20–Sb1–S1
121.90(11)
171.50(8)
96.67(11)
77.69(8)
80.27(8)
˚
˚
difference (Sb1–C17 2.097(5) A, Sb1–C23 2.118(5) A, Sb1–
˚
Table 3
C29 2.108(4) A). The two Sb–S bond lengths (Sb1–S2
˚
Selected bond lengths (A) and angles (ꢁ) for the complex 6
˚
Bond lengths (A)
˚
˚
2.6107(17) A, Sb1–S5 2.5851(17) A), which are slightly
shorter than that found in complexes 2 and 6, are in the
normal rang of that reported in triphenylantimony thio-
Sb1–C9
Sb1–C21
Sb2–C41
Sb2–C53
Sb1–S2
2.115(6)
2.135(6)
2.095(6)
2.113(7)
2.8999(17)
Sb1–C15
Sb1–C27
Sb2–C47
Sb2–C59
Sb2–S5
2.099(6)
2.179(6)
2.111(6)
2.166(6)
2.9248(17)
˚
lates (2.469–2.689 A) [13,14]. Besides, two intramolecular
˚
SbÁ Á ÁN weak interactions (Sb1Á Á ÁN1 3.245(4) A and
˚
Sb1Á Á ÁN3 3.291(4) A) have been recognized between Sb1
atom and N1, N3 atoms, which are much shorter than
the sum of van der Waals radii of Sb and N atoms,
Bond angles (ꢁ)
C9–Sb1–C15
C9–Sb1–C27
C15–Sb1–C27
C9–Sb1–S2
C21–Sb1–S2
C41–Sb2–C47
C41–Sb2–C59
C47–Sb2–C59
C41–Sb2–S5
C53–Sb2–S5
112.8(3)
96.0(2)
97.2(2)
82.62(15)
85.99(16)
111.8(2)
99.1(2)
98.1(2)
80.09(16)
85.26(18)
C9–Sb1–C21
C15–Sb1–C21
C21–Sb1–C27
C15–Sb1–S2
C27–Sb1–S2
C41–Sb2–C53
C47–Sb2–C53
C53–Sb2–C59
C47–Sb2–S5
C59–Sb2–S5
129.7(2)
114.1(2)
95.2(2)
82.94(17)
178.59(18)
125.4(3)
117.9(3)
95.3(3)
˚
3.70 A. And these intramolecular SbÁ Á ÁN weak interactions
were also supported by the spectra of complex 8. If the
two weak SbÁ Á ÁN interactions are also considered, the
geometry of Sb1 can be best described as distorted capped
trigonal prism. It is noteworthy that the two SbÁ Á ÁN are
˚
˚
of 3.245(4) A (Sb1Á Á ÁN1) and 3.291(4) A (Sb1Á Á ÁN3), which
are markedly elongated compared to those reported in
1,1,1-triphenyl-1k5-stiba-2,4,-tithia-3,5-dizazcyclopenta-2,
82.17(16)
179.2(2)

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C. Ma et al. / Journal of Organometallic Chemistry 691 (2006) 2567–2574
˚
4-diene (2.489 A) [15] and tetramethyl-(8-oxyquinolinato)-
Acknowledgment
˚
antimony (2.464 A) [16], so it is obvious that the SbÁ Á ÁN
coordination interactions in complex 8 are very weak.
The supramolecular structure of complex 8 is dominated
by one-dimensional helical polymer (Fig. 6) along the b-axis
We thank the national natural foundation (20271025)
for financial support of this work.
˚
linked by intermolecular C–HÁ Á ÁS (C25AÁ Á ÁS6 = 3.799 A,
References
˚
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hydrogen bonds, which is similar to that found in our pre-
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In summary, a series of organoantimony(V) complexes
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5. Supplementary material
Crystallographic data for the structural analysis have
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may be obtained free of charge from the Director, CCDC,
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