Synthetic, spectroscopic, X-ray structural and antimicrobial studies of 1,3-dithia-2-stibacyclopentane derivatives of phosphorus based dithiolato ligands

Article abstract of DOI:10.1016/j.poly.2006.04.027

Some mixed 1,3-dithia-2-stibacyclopentane derivatives with phosphorus based dithiolato ligands of the types over(SCH₂ CH₂ SS, -) bS (S) over(POGO, -) {where G = {single bond}CH(Me){single bond}CH(Me){single bond} and {single bond}C(Me)₂{single bond}C(Me)₂{single bond}} and over(SCH₂ CH₂ SS, -) bS (S) P (OR)₂ {where R = Prⁿ, Buⁿ and Ph} have been synthesized by the reaction of 2-chloro-1,3-dithia-2-stibacyclopentane and the ammonium/sodium salt of the corresponding phosphorus based ligands in an equimolar ratio in anhydrous benzene solution. These yellow crystalline solid/semi-solid derivatives have been characterized by elemental analysis (C, H, S and Sb), molecular weights, melting point as well as spectral [UV, IR and NMR (¹H, ¹³C and ³¹P)] studies. Single crystal X-ray diffraction analyses of 1,3-dithia-2-stibacyclopentane 2,3-butylenedithiophosphate revealed a monodentate mode of bonding of the dithiophosphate ligand in the complex. The free ligands and their antimony(III) complexes have also been screened for their antibacterial and antifungal activities.

Full text of DOI:10.1016/j.poly.2006.04.027

Polyhedron 25 (2006) 2841–2847
www.elsevier.com/locate/poly
Synthetic, spectroscopic, X-ray structural and antimicrobial
studies of 1,3-dithia-2-stibacyclopentane derivatives of
phosphorus based dithiolato ligands
a,
a
a
b
c
H.P.S. Chauhan *, U.P. Singh , N.M. Shaik , S. Mathur , V. Huch
a
School of Chemical Sciences, Devi Ahilya University, Takshshila Campus, Khandwa Road, Indore 452017, India
Leibniz-Institute of New Materials, Nanocrystalline Materials and Thin Film Systems Division, D-66123 Saarbruecken, Germany
b
c
Institute of Inorganic Chemistry, Saarland University, D-66123 Saarbruecken, Germany
Received 6 March 2006; accepted 10 April 2006
Available online 12 May 2006
Abstract
Some mixed 1,3-dithia-2-stibacyclopentane derivatives with phosphorus based dithiolato ligands of the types SCH2CH2SSbSðSÞPOGO
{where G = ACH(Me)ACH(Me)A and AC(Me)2AC(Me)2A} and SCH2CH2SSbSðSÞPðORÞ {where R = Prn, Bun and Ph} have been
2
synthesized by the reaction of 2-chloro-1,3-dithia-2-stibacyclopentane and the ammonium/sodium salt of the corresponding phosphorus
based ligands in an equimolar ratio in anhydrous benzene solution. These yellow crystalline solid/semi-solid derivatives have been char-
acterized by elemental analysis (C, H, S and Sb), molecular weights, melting point as well as spectral [UV, IR and NMR (1H, 13C and 31P)]
studies. Single crystal X-ray diffraction analyses of 1,3-dithia-2-stibacyclopentane 2,3-butylenedithiophosphate revealed a monodentate
mode of bonding of the dithiophosphate ligand in the complex. The free ligands and their antimony(III) complexes have also been
screened for their antibacterial and antifungal activities.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: 1,3-Dithia-2-stibacyclopentane; Dithiophosphates; IR; NMR spectra; Single crystal X-ray analysis; Antimicrobial activity
1. Introduction
ety of complexes with main group [5–11] as well as transi-
tion metals [12–16]. Tris as well as mixed halide
alkylenedithiophosphate and dialkyldithiophosphate deriv-
atives of antimony(III) were reported by us [6,7]. Some cor-
responding organoantimony(III) derivatives with these
ligands and mixed sulfur ligand complexes have also been
reported [3,17–19]. The crystal structures of some bis-
muth(III) [20], nickel [21] and tin [22,23] complexes with
these alkylenedithiophosphates have also been reported,
which indicate the bidentate behaviour of these alkylenedi-
thiophosphate ligands.
Diorganodithiophosphate derivatives of antimony(III)
are well known [1–4] for their utility as analytical reagents,
lubricant additives for regeneration of cracking catalysts
and antitumour agents. The chemistry of antimony(III)
with dialkyldithiophosphate ligands is well explored
including the X-ray single crystal structures of a number
of compounds [1–4].
Alkylenedithiophosphates and dialkyldithiophosphate
ligands behave as versatile dithio ligands and form a vari-
In continuation of our interest in the complexes of
group 15 metals with sulfur ligands, we report herein the
synthesis, spectral, single crystal X-ray and antimicrobial
studies of 1,3-dithia-2-stibacyclopentane derivatives of
phosphorus based dithiolato ligands.
*
Corresponding author. Tel.: +91 731 2460208; fax: +91 731 2365782.
E-mail address: hpsc@rediffmail.com (H.P.S. Chauhan).
0277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2006.04.027

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H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
2. Experimental
2.1. Materials
Solvents (benzene, alcohols, dichloromethane, n-hexane,
acetone and diethyl ether, etc.) were dried and purified
according to the literature methods [24]. Phosphorous pen-
tasulfide (E. Merck) was used as received. Ethane-1,2-
dithiol (E. Merck), antimony trichloride (S. D. Fine), glycols
[butane-2,3-diol (E. Merck) and 2,3-dimethylbutane-2,3-diol
(Aldrich)] were distilled before use. 2-Chloro-1,3-dithia-2-
stibacyclopentane [25] and the alkylene-/diorganodithio-
phosphoric acids and their sodium/ammonium salts were
synthesized by earlier reported methods [2,5].
Fig. 1. X-ray single crystal structure of 1,3-dithia-2-stibacyclopentane 2,3-
butylenedithiophosphate.
2.2. Measurements
The elemental analysis (C and H) was performed on a
Perkin–Elmer 2400 elemental analyzer. Sulfur was esti-
mated gravimetrically as barium sulfate and antimony
was estimated iodometrically titrating against standard
sodium thiosulfate solution [6,7]. Molecular weights were
determined cryoscopically in benzene. IR spectra were
recorded in KBr discs on a Perkin–Elmer 557 spectropho-
tometer in the region 4000–200 cmꢀ1. The UV spectra were
recorded in chloroform solution at room temperature on a
Shimadzu UV-1601 UV–Vis spectrophotometer within the
tion was performed at room temperature using the x–h
scan technique. The crystal structure was solved by
direct methods and refined by full-matrix least squares
on F2 using the SHELXS software package for crystal
structure solution and refinement. All non-hydrogen
atoms were refined with anisotropic thermal parameters
in the later cycles of refinement. The hydrogen atoms
were placed in idealized positions and refined using the
riding model with general isotropic temperature factors.
The data collection was performed only up to 27.87ꢁ.
Selected atomic parameters are collected in Tables 2
and 3, and the crystallographic numbering scheme is
shown in Fig. 1.
1
range 500–200 nm. H, 13C and 31P spectra of all these
newly synthesized complexes were recorded in CDCl3 solu-
tion using TMS and 85% H3PO4 as standards, respectively.
The 1H and 13C NMR spectra were operated at 300.13 and
75.49 MHz respectively, on a Bruker AC-300F NMR spec-
trophotometer at the Sophisticated Analytical Instrument
(SAIF) Facility, Punjab University, Chandigarh and 31P
NMR spectra were operated at 121.50 MHz on a DRX-
300 NMR spectrophotometer, SAIF, Central Drug
Research Institute (CDRI), Lucknow.
2.3. Antimicrobial studies
The following strains of bacteria and fungi were used:
Staphylococcus aureus (ATCC 9144), Bacillus subtilis
(ATCC 6051), Escherichia coli (ATCC 9637), Pseudomonas
aeruginosa (ATCC 25619), Aspergillus niger (ATCC 9029)
and Penicillium chrysogenum (ATCC 10106). Antimicro-
bial activities were evaluated by the disc diffusion method
[27–29] for the tested compounds as follows.
The single crystal X-ray diffraction analysis was per-
formed on a STOE IPDS (imaging plate system) diffrac-
tometer at 25 ꢁC, using graphite monochromated Mo Ka
A 0.5 mL (containing 106–107 microorganisms mLꢀ1) of
each of the investigated organisms was added to a sterile
agar medium just before solidification, then poured into
sterile petri dishes (9 cm in diameter) and left to solidify.
˚
X-ray radiation (k = 0.71073 A).
A suitable crystal,
grown from a toluene–isopropyl alcohol solution, was
sealed in a glass capillary under dry nitrogen atmosphere
and mounted on the goniometer head. The data collec-
Scheme 1. Reaction of 2-chloro-1,3-dithia-2-stibacyclopentane with sodium/ammonium dithiophosphates in an equimolar ratio.

H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
2843
Using a sterile cork borer (6 mm in diameter), three holes
(wells) were made in each dish, then 0.1 ml of tested com-
pounds dissolved in DMF (50, 100 and 200 lg mLꢀ1) were
poured into these holes. Finally the dishes were incubated
at 37 ꢁC for 24 h (for bacteria) and at 30 ꢁC for 72 h (for
fungi), then inhibition zones were detected around each
hole.
A quantity of 0.1 ml DMF alone was also tested under
the same conditions for each organism and it was found
that DMF had no effect on the organisms at the concentra-
tions studied.
2.4. Synthesis of mixed 1,3-dithia-2-stibacyclopentane
alkylene-/dialkyl-dithiophosphate derivatives
2.4.1. Synthesis of 1,3-dithia-2-stibacyclopentane
2,3-butylenedithiophosphate
A benzene solution (30 ml) of 2-chloro-1,3-dithia-2-sti-
bacyclopentane (0.72 g, 2.88 mmol) was added to the
ammonium salt of 2,3-butylenedithiophosphoric acid
(0.58 g, 2.88 mmol) in an equimolar ratio (Scheme 1).
The reaction mixture was refluxed with stirring for ꢁ5 h
followed by cooling to room temperature. The precipi-
tated ammonium chloride (0.15 g) was removed by filtra-
tion. The removal of the solvent from the filtrate under
reduced pressure afforded a yellow crystalline compound,
which was recrystallised in dichloromethane (yield: 1.13 g,
98%).
The other complexes were synthesized by adopting a
similar method. Pertinent analytical and physico-chemical
data for these complexes are listed in Table 1.
3. Results and discussion
3.1. Synthesis of antimony(III) complexes
1,3-Dithia-2-stibacyclopentane derivatives with alkyl-
ene-/dialkyl-dithiophosphate have been synthesized by
the reactions of 2-chloro-1,3-dithia-2-stibacyclopentane
with the ammonium/sodium salts of alkylene-/dialkyl-
dithiophosphoric acids in an equimolar (1:1) ratio in reflux-
ing benzene ꢁ5 h.
All these newly synthesized derivatives are either yellow
crystalline solids or yellow sticky solids and are soluble in
common organic solvents like benzene, chloroform, ace-
tone, dichloromethane, DMF and DMSO, etc., but decom-
pose in water.
3.2. Electronic spectra
In the electronic absorption spectra [12–15,26], all the
1,3-dithia-2-stibacyclopentane dithiophosphate derivatives
absorb strongly in the region 230–235 nm, corresponding
to a p–p* transition. Another rather weak absorption
occurs at 304–309 nm, which may be due to a n–p* tran-
sition. These dithiophosphates also absorb in these
regions.

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H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
Table 2
Table 3
˚
Crystal data and refinement details for 1,3-dithia-2-stibacyclopentane
2,3-butylenedithiophosphate
Selected bond distances (A) and bond angles (ꢁ) for 1,3-dithia-
2-stibacyclopentane 2,3-butylenedithiophosphate
Compound
SCH2CH2SSbS2POCHðCH3ÞCHðCH3ÞO
Bond distances
Sb(1)–S(2)
Sb(1)–S(1)
Sb(1)–S(3)
S(1)–C(1)
S(2)–C(2)
S(3)–P(1)
S(4)–P(1)
P(1)–O(1)
P(1)–O(2)
O(1)–C(4)
O(2)–C(3)
C(1)–C(2)
C(3)–C(5)
C(3)–C(4)
C(4)–C(6)
2.4485(9)
2.4491(10)
2.5566(13)
1.834(3)
1.842(3)
2.0541(12)
1.9456(16)
1.602(2)
1.608(3)
1.477(4)
1.481(4)
1.504(6)
1.519(5)
1.525(5)
1.513(5)
Formula
C6H12O2PS4sSb
397.12
Formula weight
Crystal system
Space group
monoclinic
P21/n
11.641(2)
10.528(2)
12.472(2)
90
117.78(3)
90
1352.4(4)
4
˚
a (A)
˚
b (A)
˚
c (A)
a (ꢁ)
b (ꢁ)
c (ꢁ)
3
˚
V (A )
Z
Crystal size (mm3)
0.28 · 0.2 · 0.15
1.950
776
Dc (Mg mꢀ3
F(000)
)
Reflection collected
12095
Bond angles
hmax (ꢁ)
2.67–27.87
0.48 and 0.30
S(2)–Sb(1)–S(1)
S(2)–Sb(1)–S(3)
S(1)–Sb(1)–S(3)
C(1)–S(1)–Sb(1)
C(2)–S(2)–Sb(1)
P(1)–S(3)–Sb(1)
O(1)–P(1)–O(2)
O(1)–P(1)–S(4)
O(2)–P(1)–S(4)
O(1)–P(1)–S(3)
O(2)–P(1)–S(3)
S(4)–P(1)–S(3)
C(4)–O(1)–P(1)
C(3)–O(2)–P(1)
C(2)–C(1)–S(1)
C(1)–C(2)–S(2)
O(2)–C(3)–C(5)
O(2)–C(3)–C(4)
C(5)–C(3)–C(4)
O(1)–C(4)–C(6)
O(1)–C(4)–C(3)
C(6)–C(4)–C(3)
87.80(3)
94.83(4)
92.17(4)
97.97(11)
100.36(11)
95.79(5)
97.52(13)
116.06(12)
112.98(12)
105.68(10)
109.30(12)
113.89(6)
111.40(19)
109.48(19)
111.6(2)
112.0(3)
109.2(3)
104.1(3)
116.2(3)
109.3(3)
103.5(3)
116.1(3)
Maximum and minimum
transmission
Final R indices [I > 2r (I)]
R1
wR2
0.0366
0.1007
R indices (all data)
R1
wR2
0.0384
0.1020
0.928
ꢀ0.702
3
˚
Residual qmax (e A )
Residual qmin (e A )
3
˚
3.3. Infra-red spectra
These newly synthesized complexes show medium to
strong intensity bands in the regions 1000–1030 cmꢀ1 and
830–860 cmꢀ1 which are assigned due to m{(P)–O–C} and
m{P–O–(C)}, respectively [5–8,17,18]. A broad band in
the region 690–720 cmꢀ1 (alkylenedithiophosphates) and
660–690 cmꢀ1 (dialkyldithiophosphates) due to m(P@S),
present in the free phosphoric acids, is shifted towards
lower frequencies in the spectra of all these complexes
and is present in the regions 650–660 and 635–645 cmꢀ1
respectively, this also overlaps with the m(C–S) vibrations
of dithiolate moieties in these complexes. A sharp band
present in the region 925–930 cmꢀ1 in the corresponding
alkylenedithiophosphate may be assigned to the ring
vibrations of the dioxaphospholane ring [30]. The bands
of medium to weak intensity in the regions 530–540 and
310–320 cmꢀ1 are assigned to m(P–S) and m(Sb–S), respec-
tively [17].
CH2S protons of the 1,3-dithia-2-stibacyclopentane ring
[17,18], indicating that these protons are equivalent. In
addition, these compounds also exhibit the characteristic
proton resonances [5–18] for the corresponding protons
of dithiophosphate moieties (Table 4). In a few of the
alkylene-/dialkyl-dithiophosphate derivatives, OCH and
OCH2 protons couple with 31P nuclei and appear as a mul-
tiplets and doublets of triplets.
3.4.2. 13C NMR spectra
The 13C NMR spectra of the ethane-1,2-dithiolate moi-
ety show only one sharp singlet signal in the region d
41.41–42.40 ppm due to SCH2 carbons [17,18] indicating
that these two carbon atoms are magnetically equivalent,
thus supporting the results of the 1H NMR spectra. In
addition, these derivatives also exhibit the expected signals
due to the carbons of dithiophosphate moieties [5–17]. The
methylene carbons attached to P–O and P–O–C groups
3.4. NMR spectral data
1
3.4.1. H NMR spectra
The chemical shifts corresponding to the protons of
mixed 1,3-dithia-2-stibacyclopentane derivatives with alk-
ylene-/dialkyl-dithiophosphate are listed in Table 4. In
1
the H NMR spectra of these compounds, a sharp singlet
observed in the region d 3.61–3.74 ppm is due to four

H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
2845
Table 4
1H, {1H}13C and 31P NMR spectral data of 1,3-dithia-2-stibacyclopentane alkylene-/dialkyl-dithiophosphate complexes
Compound (No.)
1H Chemical shifts (d ppm)
13C Chemical shifts
31P Chemical
(d ppm)
shifts (d ppm)
1.31 (6H, d (J = 6.3 Hz), CH3)
3.71 (4H, s, CH2S)
4.65–4.70 (2H, m, OCH)
15.46 (s, Me)
42.40 (s, CH2S)
79.10 (s, OCH)
108.14
103.7
90.90
S
S
OCH(Me)
CH2
Sb
P
P
P
CH2
S
S
O
CH(Me)
(1)
1.45 (12H, s, OCMe2)
3.74 (4H, s, CH2S)
24.17 (s, Me2)
42.14 (s, CH2S)
90.92 (s, OC)
S
S
C(Me)
O
2
CH2
CH2
Sb
O
S
C(Me)2
S
S
(2)
0.93 (6H, t (J(CH3-CH2) = 7.35 Hz), OCCCH3dtp)
1.69 (4H, m, OCCH2-dtp)
3.69 (4H, s, CH2S)
4.02 {4H, dt (J(OCH2-CH2) = 6.54 Hz and
J(PO-CH2) = 9.34 Hz), OCH2-dtp}
9.73 (s, OCCCH3-dtp)
22.75 (s, OCCH2-dtp)
41.41 (s, CH2S)
S
S
OPr-n
OPr-n
CH2
CH2
Sb
68.67 (s, OCH2-dtp)
S
S
(3)
0.88 (6H, t (J(CH3-CH2) = 7.37 Hz), OCCCCH3dtp) 13.61 (s, OCCCCH3-dtp)
90.89
S
OBu-n
OBu-n
1.36 (4H, m, OCCCH2-dtp)
1.64 (4H, m, OCCH2-dtp)
3.67 (4H, s, CH2S)
18.76 (s, OCCCH2-dtp)
31.88 (d (J = 8.60 Hz), OCCH2-dtp)
42.03 (s, CH2S)
CH2
CH2
Sb
P
S
4.06 {4H, dt (J(OCH2-CH2) = 6.49 Hz and
J(PO-CH2) = 9.19 Hz), OCH2-dtp}
67.60 (d (J = 7.17 Hz), OCH2-dtp)
S
S
(4)
3.61 (4H, s, CH2S)
42.26 (s, CH2S)
88.13
S
OPh
OPh
7.19–7.37 (10H, m, OC6H5)
122.08 (s, m-C of C6H5)
125.85 (s, o-C of C6H5)
129.49 (s, p-C of C6H5)
CH2
CH2
Sb
P
S
S
(5)
Where b = broad, s = singlet, d = doublet, t = triplet, q = quartet, dt = doublet of triplets and m = multiplet.
give rise to a doublet for compound No. 4 due to the cou-
pling with 31P nuclei [9] (Table 4).
NMR signals in the range d 82–101 exhibit a bidentate
mode of attachment of the ligands, thus indicating the
bidentate mode of binding of diorganodithiophosphate
ligands in these synthesized complexes. It is valid for many
cases, however doubts have been made about the universal-
ity of the above generalization [32,33].
3.4.3. 31P NMR spectra
The proton decoupled 31P NMR spectra show only one
sharp singlet between d 103.7–108.1 ppm (in alkylenedi-
thiophosphate derivatives). Chemical shift values appear
to be downfield by about d 10–13 ppm with respect to their
parent alkylene dithiophosphoric acids (d 93.07–
95.49 ppm) indicating the bidentate behaviour of these
dithiophosphate ligands. The corresponding complexes
with dialkyldithiophosphate ligands show a 31P signal in
the region d 88–91 ppm. Glidewell [31] concluded that
diorganodithiophosphate complexes showing their 31P
3.5. Crystal structure
The solid-state structure of the compound 1,3-dithia-2-
stibacyclopentane 2,3-butylenedithiophosphate has been
established by single crystal X-ray analysis, which revealed
a monomeric unit. The molecular structure of 1,3-dithia-2-
stibacyclopentane 2,3-butylenedithiophosphate is shown in

2846
H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
Fig. 1 and selected interatomic parameters are collected in
Table 3. The antimony atom forms three close contacts,
two to the ethane-1,2-dithiolato sulfur atoms, Sb(1)–S(2)
3.6. Antimicrobial activity
The free ligands and their antimony(III) complexes
were screened to evaluate their antimicrobial activity
against S. aureus, B. subtilis, E. coli, P. aeruginosa, A.
niger and P. chrysogenum at three different concentra-
tions, and results are listed in Table 5. The antibacterial
activities of some earlier reported antibiotics [29] were
compared with the free ligands and their antimony(III)
complexes.
The results showed that the antimony(III) complexes
exhibit higher antibacterial and antifungal activity than
the free diorganodithiophosphate ligands (dtp). It is notice-
able here that E. coli and P. aeruginosa are resistant to the
free dtp ligands. It may be concluded that the free ligands
and antimony complexes inhibit the growth of bacteria to a
greater extent as the concentration is increased. Neverthe-
less, it is difficult to make out an exact structure and activ-
ity relationship between microbial activity and the
structure of these complexes.
˚
˚
(2.4485 A) and Sb(1)–S(1) (2.4491 A), and one to the dith-
˚
iophosphato sulfur atom, Sb(1)–S(3) (2.5566 A). If these
three close contacts were considered to define the coordina-
tion geometry, the dithiophosphate ligand behaves in a
monodentate fashion. Considering the observed Sb–S
interactions, the environment about the antimony would
be best described as trigonal pyramidal with the lone pair
of electrons being stereochemically active, but with non-
equivalent S–Sb–S bond angles [87.80(3)ꢁ, 92.17(4)ꢁ and
94.83(4)ꢁ] (Table 3) [34]. The phosphorus atom is tetrahe-
drally coordinated to two sulfur and two oxygen atoms,
which are further attached with carbon atoms of the alkyl-
ene group (Fig. 1). The crystal structure shows that the
heteroalkylene ring is markedly non-planar and that the
configuration of the bonds about the antimony atom is
nearly orthogonal.
The structure of this compound is unique as in this
compound the 2,3-butylenedithiophosphate ligand is exhib-
iting monodentate behaviour. However, in most alkylenedi-
thiophosphate derivatives of main group metals,
bismuth(III) [20] and organotin(IV) [22,23], the bidentate
behaviour of these alkylenedithiophosphate ligands has
been reported. However, in (2,9-dimethyl-1,10-phenanthro-
line) bis(4,4,5,5-tetramethyl-1,3,2-dioxaphospholane-2-thi-
one-2-thiolato)-nickel(II), one ligand is unidentate and the
other one is bidentate [21]. It is also noticeable here that
diorganodithiophosphate and dithiophosphinate ligands
exhibited a bidentate as well as a bidentate triconnective
chelating nature in their antimony(III) complexes [2,3].
A comparison of the antimicrobial activities of the
free ligands and synthesized complexes with some previ-
ously investigated antibiotics [29] shows the following
results:
(i) The free ligands (dtp) and their antimony(III) com-
pounds show a greater effect towards S. aureus com-
pared to amikacin, septrin, cefobid, ampicillin and
traivid. However, the free ligands (dtp) and anti-
mony(III) compounds show a lesser effect towards
S. aureus compared to doxycllin, augmantin, sulpera-
zon, unasyn, nitrofurantion and erythromycin.
Table 5
Antimicrobial activitya of the free dithiophosphate ligands and 1,3-dithia-2-stibacyclopentane alkylene-/dialkyl-dithiophosphate complexes
Compounds
Fungi
Gram (+ve) bacteria
S. aureus
Gram (ꢀve) bacteria
A. niger
P. chysogenum
Conc. (lg/mL)
50 100 200
B. subtilis
E. coli
P. aeruginosa
Conc. (lg/mL)
50 100 200
Conc. (lg/mL)
Conc. (lg/mL)
Conc. (lg/mL)
50 100 200
Conc. (lg/mL)
50
+
100
+
200
+
50
+
100
+
200
+
50
0
100 200
(CH3CH2CH2O)2PS2Na
(CH3CH2CH2CH2O)2PS2Na
(C6H5O)2PS2NH4
+
+
+
+
++
++
+
+
+
+
++
++
0
0
0
0
0
0
0
0
0
0
+
+
+
+
+
+
0
+
+
+
+
++
++
+
+
+
+
++
+
+
+
+
+
+
+
+
+
+
+
++
++
0
0
0
0
0
0
0
0
0
0
0
0
OCHðCH3ÞCHðCH3ÞOPS2NH4
+
+
+
+
+
+
+
+
+
+
+
+
0
0
0
0
0
0
OCðCH3Þ2CðCH3Þ2OPS2NH4
(1)
(2)
(3)
(4)
(5)
+
+
+
+
+
++ +++
++ +++
++ +++
++ ++
+
+
+
+
+
++ +++ ++ +++ +++
++ +++ ++ +++ +++
++ +++ ++ +++ +++
+
+
+
+++ +++
+
+
+
+
+
++ +++
++ +++
++ +++
+
+
+
++ +++
++ +++
++ +++
++
++
+++
+++
+++
+++
++ ++
++ ++
++ ++
+++ ++ ++
+
+
+
+
++ ++ +++
++ ++
+
+
ꢀ
++
++
++
ꢀ
++ ++
+
+
ꢀ
+
++
Chloroamphenicol
ꢀ
+
ꢀ
ꢀ
ꢀ
+
ꢀ
ꢀ
+
+
+
++
+
++ +++
++ +++
Terbinafin
++ ++
++ ++
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
a
The test was done using the diffusion agar technique, well diameter = 6 mm, inhibition values beyond control are + = 1–5 mm, ++ = 6–10 mm,
+++ = 11–15 mm, 0 = not active and – = not tested.

H.P.S. Chauhan et al. / Polyhedron 25 (2006) 2841–2847
2847
(ii) The antimony(III) compounds show a greater anti-
bacterial effect towards P. aeruginosa than doxycillin,
augmantin, unasyn, septrin, cefobid, nitrofurantion,
traivid, erythromycin and free dtp ligands. However,
the antimony(III) compounds show a lesser effect
towards P. aeruginosa compared to amikacin, sulper-
azon and chloroamphenicol.
(iii) The antimony(III) complexes show a greater effect
towards E. coli compared to unasyn, cefobid, ampi-
cillin, erythromycin and dtp ligands (resistance to
E. coli). However, the antimony(III) compounds
show a lesser effect towards E. coli compared to ami-
kacin, doxycllin, augmantin, sulperazon, nitrofuran-
tion, traivid and chloroamphenicol.
University, Chandigarh. The authors are also thankful to
S. Srivastava, Holkar Science College, for providing facili-
ties for antimicrobial studies and to Dr. D. Buddhi for
UV–Vis spectra.
References
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From all of the above results we can conclude that some
of the free ligands and their antimony complexes show
greater antibacterial effects to some of the investigated
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4. Conclusions
Present study describes a series of 1,3-dithia-2-stiba-
cyclopentane complexes with alkylene-/dialkyl-dithio-
phosphate. On the basis of physico-chemical and
spectroscopic data we propose a monodentate behaviour
of these ligands in these complexes, which is further con-
firmed by the X-ray crystal structure of 1,3-dithia-2-stiba-
cyclopentane 2,3-butylenedithiophosphate.
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mony(III) derivatives has been studied by the disc diffusion
method on various microorganisms. All antimony(III)
complexes exhibit greater antimicrobial activity compared
to that of the free ligands. The free alkylene-/dialkyl-
dithiophosphate and their mixed antimony compounds
exhibited a higher antibacterial effect than the some of
the previously investigated antibiotics.
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5. Supplementary materials
Crystallographic data, tables of atomic coordinates,
thermal parameters, bond lengths and bond angles of the
structure have been deposited with the Cambridge Crystal-
lographic Data Centre, with the deposition number:
604201. Copies of this are available free of charge from
the Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK (fax: +44 1223 336 033; deposit@ccdc.cam.ac.uk
or www: http://www.ccdc.cam.ac.uk).
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Acknowledgements
Elemental analyses as well as spectral studies were car-
ried out at the SAIF of the CDRI, Lucknow and Punjab
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