Synthesis, characterization and biological activities of some new organotin(IV) derivatives: Crystal structure of [(Sn Ph3) (OOCC6H4OH)] and [(SnMe3)2 (OOC)2C6Cl4 (DMSO)2]

Article abstract of DOI:10.1016/j.jorganchem.2008.06.027

Some new organotin(IV) carboxylates 1-3 of 2-hydroxybenzoic acid (L_A) and 4-6 of 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid (L_B) have been synthesized, respectively, by the esterification of triorganotin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The compound 4 was dissolved in DMSO and a new compound 4 · 2DMSO [(SnMe₃)₂(OOC)₂C₆Cl₄(DMSO)₂] was crystallized out. The structure shows that two Sn moieties are attached to the ligand (L_B) through two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule, having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhibited significant antifungal activities and have a potential to be used as drugs.

Full text of DOI:10.1016/j.jorganchem.2008.06.027

Journal of Organometallic Chemistry 693 (2008) 3043–3048
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis, characterization and biological activities of some new organotin(IV)
derivatives: Crystal structure of [(Sn Ph3) (OOCC6H4OH)] and
[(SnMe3)2 (OOC)2C6Cl4 (DMSO)2]
b
a,
c
M. Khawar Rauf a, M. Adeel Saeed a, Imtiaz-ud-Din a, , M. Bolte , A. Badshah , B. Mirza
*
*
a Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan
b Institut für Anorganische Chemie, J.W. Goethe-Universität Frankfurt Max-von-Laue-Str. 7, 60438 Frankfurt/Main, Germany
c Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 18 April 2008
Received in revised form 16 June 2008
Accepted 17 June 2008
Available online 25 June 2008
Some new organotin(IV) carboxylates 1–3 of 2-hydroxybenzoic acid (LA) and 4–6 of 2,3,4,5-tetrachloro-6-
(methoxycarbonyl) benzoic acid (LB) have been synthesized, respectively, by the esterification of triorga-
notin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR (1H,
13C and 119Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in
solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The
compound 4 was dissolved in DMSO and a new compound 4 ꢀ 2DMSO [(SnMe3)2(OOC)2C6Cl4(DMSO)2]
was crystallized out. The structure shows that two Sn moieties are attached to the ligand (LB) through
two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen
atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule,
having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhib-
ited significant antifungal activities and have a potential to be used as drugs.
Keywords:
Organotin(IV)
o-Hydroxybenzoic acid
3,4,5,6-Tetrachlorophthalic anhydride
X-ray structure
Biological activities
Ó 2008 Elsevier B.V. All rights reserved.
1. Introduction
roisophthalonitrile (chlorthalonil) has both agricultural and house-
hold uses, however, its prolonged exposure may cause skin rashes
The chemistry of substituted aromatic carboxylic acids such as
acetylsalicylic acid and phenyl acetic acids have been a subject of
study in life sciences, particularly for their in vitro antitumor,
anti-inflammatory and antipyretic properties [1–3]. The syntheses
of metal complexes with such type of active ligands are a research
area of increased interest for inorganic, pharmaceutical and medic-
inal chemistry as an approach to the development of new drugs
[4]. This is because the judicious choice of ligands can modulate
the properties of complexes. The on co-protective roles of food de-
rived polyphenol antioxidants have been well documented but
their mechanism have yet to be known [5]. Triorganotin salicylate
and substituted phenol derivatives have been actively studied
group of organotin compounds for their possible bactericidal
[6,7], fungicidal [8,9], and antifouling [10] activities. The main phe-
nolic acids found in food are mostly derivatives of 4-hydroxyben-
zoic acid and 4-hydroxycinnamic acid and the possible role of
phenolic acids in cancer protective and antigenocity has also been
investigated [11,12]. The widely used fungicide 2,4,5,6-tetrachlo-
[13,14]. So there is a need to develop such fungicides which do not
pose serious threats to the environment as well as to the human
beings. Chloroderivative such as 2,20-methylene-bis (3,4,6-trichlo-
rophenol) (hexachlorophene) served as a useful anti-infective and
anti-bacterial agent in cosmetics and agriculture, particularly for
citrus mite control [15]. In continuation to our previous work
[16,17], herein we report the syntheses, characterization and bio-
logical studies of tin(IV) derivatives with 2-hydroxybenzoic acid
and 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid to
widen their scope in biological applications (Scheme 1).
2. Experimental
2.1. General
Triorganotin(IV) hydroxides/oxides were purchased from Al-
drich/Alfa Aesar while the salicylic acid and 3,4,5,6-tetrachloroph-
thalicanhyride were procured from Peoples Republic of China and
used as received. The 3,4,5,6-tetrachlorophthalicanhyride was con-
verted into a hemi- ester by a reported procedure [18] (Scheme 1).
All chemical reactions were carried out in common organic sol-
vents which were dried before use in accordance to standard meth-
ods [19].
* Corresponding authors.
E-mail addresses: drimtiazuddin@yahoo.com (Imtiaz-ud-Din), aminbadshah@
yahoo.com (A. Badshah).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.06.027

3044
M. Khawar Rauf et al. / Journal of Organometallic Chemistry 693 (2008) 3043–3048
a
b
O
C
O
C
SnR3
OH
O
Toluene
Reflux
H2O
[R3Sn]nX
+
+
OH
OH
(LA)
(1-3)
Cl
O
Cl
O
Cl
Cl
C
Cl
Cl
C
OH
Reflux
CH3OH
(excess)
O
+
OCH3
C
C
O
O
Cl
Cl
(LB)
Cl
O
C
Cl
SnR3
O
O
Toluene
Reflux
[R3Sn]nX
(LB)
+
H2O/ CH3OH
+
Cl
C
O
SnR3
Where R = CH3, X = OH, n = 1 (1,4)
R = n-C4H9, X = O, n = 2 (2,5)
R = C6H5, X = OH, n = 1 (3,6)
Cl
(4-6)
Scheme 1.
Elemental analyses were carried out by Leco CHNS-932 ana-
lyzer (USA). Melting points were determined with a Gallenkemp
(UK) apparatus and are uncorrected. Infrared spectra were re-
corded on Bio-Rad Excalibur FT-IR Model FTS 3000 MX as KBr discs
2.4. Synthesis & characterization of compounds 1–6
The methodology of [26,27] was followed for the synthesis of
target compounds 1–6 as mentioned in Scheme 1. Appropriate
stoichiometric ratios of the respective organotin hydroxides/oxides
and ligands LA or LB were suspended in dry toluene (50 ml) and re-
fluxed for 6–8 h under inert atmosphere. Water formed during the
reaction was removed by Dean–Stark apparatus. The contents were
allowed to stand for sometime at room temperature and the sol-
vent was then evaporated on rotary evaporator and the solid mass,
thus obtained, was recrystallized in chloroform/n-hexane (3:1) for
1–3 and DMSO for 4–6.
4000–400 cmꢁ1 1H and 13C NMR spectra in solution(s) were re-
.
corded at ambient temperature on a Bruker 300 spectrometer
operating at 300 and 75.45 MHz, respectively, using TMS as an
internal reference. 119Sn NMR spectra were obtained on a Bruker
300 spectrometer with Me4Sn as an external reference.
2.2. X-ray crystallography
Crystals of 3 and 4 ꢀ 2DMSO were grown by slow evaporation of
chloroform/DMSO solutions at room temperature. The colorless
crystals were mounted in random orientation on a glass fiber on
a Stoe IPDS-II two circle diffractometer [20] equipped with graph-
2.4.1. Synthesis of 2-hydroxybenzoatotrimethyltin(IV) (1) [26]
Quantities used were 0.138 g (1 mmol) LA and 0.18 g (1 mmol)
trimethyltin hydroxide in toluene. Yield: 86%. M.p.: 145.7 °C. Anal.
Calc. for C10H14O3Sn (300.90): C, 39.92; H, 4.69. Found: C, 40.01; H,
4.74. 1H NMR (300 MHz, CDCl3, d, 2J [119Sn–1H] in Hz): 0.59 [59.0]
(s, 9H, H3C–Sn); 6.9–7.9 (m, 4H, H4C6–); 5.4 (s, 1H, HO-Ph).13C NMR
(75.45 MHz, CDCl3, d, nJ [119Sn–13C] in Hz): ꢁ2.8 [392.8] (H3C–Sn);
115.6, 115.8, 122.3, 131.6, 135.2, 161.7(H4C6OH); 172 (COO). 119Sn
ite monochromated Mo Ka radiation (k = 0.71073 Å). An empirical
absorption correction was performed using the MULABS option in
PLATON [21]. The structures were solved by direct methods using
SHELXS-97 and refined with full-matrix least-squares on F2 with
SHELXL-97 [22]. All non-hydrogen atoms were refined anisotropi-
cally. Hydrogen atoms were located in a difference map but refined
using a riding model. Table 1 summarizes the crystal data and
refinement details. For molecular graphics XP from the SHELXTL suite
[23] was used.
NMR (CDCl3, d): 140.6. IR (KBr disc, cmꢁ1):
(COO) 1348, = 233; (Sn–C) 586; (Sn–O) 498.
masym(COO) 1581, msym-
D
m
m
m
2.4.2. Synthesis of 2-hydroxybenzoatotributyltin(IV) (2) [8]
Quantities used were 0.28 g (2 mmol) LA and 0.60 g (1 mmol)
Bis(tributyltin)oxide in toluene. Yield: 74%. M.p.: 68.9 °C. Anal.
Calc. for C19H32O3Sn (427.12): C, 53.43; H, 7.5. Found: C, 53.54;
H, 7.48%. 1H NMR (300 MHz, CDCl3, d): 0.9 (t, 9H, H3C–), 1.2–1.6
(m, 18H, (H2C)3–Sn); 6.8–7.9 (H4C6–); 5.4 (HO-Ph). 13C NMR
(75.45 MHz, CDCl3, d, nJ [119Sn–13C] in Hz): 17.5[344], 27.6[24],
2.3. Biological studies
The compounds 1–6 were preliminary screened against various
strains of bacteria and fungi by agar well diffusion and agar tube
dilution protocol methods, respectively [24,25].

M. Khawar Rauf et al. / Journal of Organometallic Chemistry 693 (2008) 3043–3048
3045
Table 1
2.4.5. Synthesis of 3,4,5,6-Tetrachlorophenyl-1,2-
dicarboxylatobis[tributyltin(IV)] (5) [10]
Crystallographic data for compounds 4 ꢀ 2DMSO and 3
Quantities used were 0.32 g (1 mmol) LB and 0.60 g (1 mmol)
Bis(tributyltin)oxide in toluene. Yield: 80%. M.p.: 82.5 °C. Anal.
Calc. for C32H54O4Cl4Sn (621.414): C, 61.85; H, 8.75. Found: C,
61.32; H, 8.91%. 1H NMR (300 MHz, DMSO-d6, d): 0.9 (t, 9H, H3C–
Sn); 1.3–1.7 (m, 18H, (H2C)3–Sn). 13C NMR (75.45 MHz, DMSO-d6,
d, nJ [119Sn–13C] in Hz):17.3[520], 27.4, 25.7, 13.7 (C4H9–Sn);
131.5, 131.8, 139.5 (C6Cl4); 171 (COO). 119Sn NMR (DMSO-d6, d):
4 ꢀ 2DMSO
3
Empirical formula
Formula weight
Wavelength (Å)
Crystal system
Space group
a (Å)
C
18H30Cl4O6S2Sn2
C25H20O3Sn
487.10
0.71073
Monoclinic
P21/c
13.2865(7)
12.0286(7)
14.5970(9)
90
116.694(4)
90
2084.2(2)
4
1.552
1.249
785.72
0.71073
Triclinic
ꢀ
P1
9.4556(6)
17.7707(12)
18.8485(12)
73.964(5)
79.412(5)
78.549(5)
2955.3(3)
4
1.766
2.222
1544
0.28 ꢂ 0.25 ꢂ 0.18
3.52–25.58°
ꢁ11 6 h 6 11
ꢁ21 6 k 6 21
ꢁ20 6 l 6 22
31504
b (Å)
c (Å)
ꢁ68.4. IR (KBr disc, cmꢁ1);
m
asym(COO) 1555,
msym(COO) 1342,
a
(°)
Dm = 213, m(Sn–C) 556, m(Sn–O) 460, m(Ar–Cl) 1128.
b (°)
c
(°)
Volume (Å3)
2.4.6. Synthesis of 3,4,5,6-tetrachlorophenyl-1,2-
dicarboxylatobis[triphenyltin(IV)] (6)
Z
Density (Mg/m3) (calculated)
Absorption coefficient (mmꢁ1
F(000)
Quantities used were 0.32 g (1 mmol) LB and 0.74 g (2 mmol)
triphenyltin hydroxide in toluene. Yield. 80%; M.p.: 131.6 °C. Anal.
Calc. for C44H30O4SnCl4 (883.176): C, 59.83; H, 3.42. Found: C,
59.46; H, 3.59%. 1H NMR (300 MHz, DMSO-d6, d); 7.3–7.8 (m,
30H, H5C6–Sn). 13C NMR (75.45 MHz, DMSO-d6, d, nJ [119Sn–13C]
in Hz): 131.7, 132.4, 139.8 (C6Cl4); 128.7[794], 129.4, 131.8,
137.5 (C6H5–Sn); 169.8 (COO). 119Sn NMR (DMSO-d6, d): ꢁ174. IR
)
976
Crystal size (mm3)
Theta range
Index ranges
0.23 ꢂ 0.11 ꢂ 0.10
3.50–25.57°
ꢁ16 6 h 6 16
ꢁ14 6 k 6 14
ꢁ17 6 l 6 17
26465
Reflections collected
Independent reflections [Rint
Completeness to
theta = 25.00°
(KBr disc, cmꢁ1):
(Sn–C) 536; (Sn–O) 484; m
m
asym(COO) 1549, mmsym(COO) 1334,
(Ar–Cl) 1131.
Dm = 215;
]
11037 [0.0513]
99.6%
3893 [0.0941]
99.7%
m
m
Absorption correction
Empirical
Empirical
from equivalents
0.6905 and 0.5750
from equivalents
0.8853 and 0.7621
3. Results and discussion
Maximum and minimum
transmission
Some new organotin(IV) derivatives of substituted phenyl car-
boxylic acids were prepared by the reaction of the ligands LA or
LB with the selected triorganotin(IV) hydroxide/oxide in appropri-
ate mole ratio in dry toluene, using the Dean–Stark apparatus
(Scheme 1). The compounds 1–6 are quite stable in moist-air and
are also soluble in common organic solvents.
Refinement method
Full-matrix least-
squares on F2
11037/0/597
1.017
R1 = 0.0411,
wR2 = 0.1033
R1 = 0.0509,
Full-matrix least-
squares on F2
3893/0/267
Data/restraints/parameters
Goodness-of-fit on F2
0.953
Final R indices [I > 2
R indices (all data)
r
(I)]
R1 = 0.0326,
wR2 = 0.0625
R1 = 0.0517,
wR2 = 0.0663
0.488 and ꢁ0.799
wR2 = 0.1074
2.667 and ꢁ2.596
Largest difference peak and
hole (e Åꢁ3
3.1. Spectroscopic data
)
The compounds 1–6 were characterized by multinuclear (1H,
13C, 119Sn) NMR, IR spectroscopy and single crystal X-ray analysis
in combination with melting point and elemental analyses. The
spectroscopic data have been mentioned in the synthesis Section
2.2. The 1H NMR spectra were recorded for the compounds 1–3
in CDCl3 and in DMSO-d6 for 4–6. The characteristic chemical shifts
were identified by their intensity and multiplicity patterns. The to-
tal numbers of protons, calculated from the integration curve, are
in agreement with the expected molecular composition of the
compounds. The proton chemical shifts assignment of the carbon
attached to Sn exhibits a singlet at 0.59 ppm for compounds 1
and 4 and at nearly 1.6 ppm as multiplets in case of compounds
2 and 5. The aromatic protons of the ligand and the phenyltin moi-
eties for 3 and 6 resonate as multiplets in the expected range 6.84–
7.93 ppm [28]. The proton chemical shift assignment of the tri-
methyltin moiety is straight forward from the multiplicity pattern
and the 2J [119Sn–1H] coupling constant values. The C–Sn–C angles,
calculated by applying Lockhart’s equation [29] Table 3, also sup-
port the tetrahedral environment around the Sn atom for 1. How-
ever, coupling constant, nJ [119Sn–1H] for n-butyl and phenyltin
derivatives could not be calculated due to their complex multiplet
pattern.
26.6[62], 13.5 (C4H9–Sn); 115.6, 115.8, 122.3, 131.8, 135.6, 162.4
(C6H4OH); 172 (COO).119Sn NMR (CDCl3, d): 114.7. IR (KBr disc,
cmꢁ1):
(Sn–O) 486.
masym(COO) 1558, msym(COO) 1334, Dm = 224; m(Sn–C) 567;
m
2.4.3. Synthesis of 2-hydroxybenzoatotriphenyltin(IV) (3) [8]
Quantities used were 0.14 g (1 mmol) LA and 0.37 g (1 mmol)
triphenyltin hydroxide in toluene. Yield: 81%. M.p.: 121.3 °C. Anal.
Calc. for C25H20O3Sn (486.25): C, 61.75; H, 4.14. Found: C, 61.84; H,
4.37%. 1H NMR (300 MHz, CDCl3, d): 6.9–7.9 (m, 4H, C6H4–), 5.4 (s,
1H, HO-Ph), 7.2–7.3 (m, 15H, (C6H5)3–Sn). 13C NMR (75.45 MHz,
CDCl3, d, nJ [119Sn–13C] in Hz): 115.6, 116.1, 121.5, 131.8, 134.9,
161.7 (C6H4OH); 138.0[646], 136.9[48], 130.2, 128.7(C6H5–Sn);
172.6 (COO). 119Sn NMR (CDCl3, d): ꢁ108.6. IR (KBr disc, cmꢁ1);
m
asym(COO) 1575,
msym(COO) 1344, Dm = 231, m(Sn–C) 551; m(Sn–
O) 445.
2.4.4. Synthesis of 3,4,5,6-tetrachlorophenyl-1,2-
dicarboxylatobis[trimethyltin(IV)] (4)
Quantities used were 0.32 g (1 mmol) LB and 0.36 g (1 mmol)
trimethyltin hydroxide in toluene. Yield: 78%. M.p.: 159 °C. Anal.
Calc. for C14H18 O4Cl4 Sn2 (510.78): C, 32.92; H, 3.54. Found: C,
32.45; H, 4.01%. 1H NMR (300 MHz, DMSO-d6, d): 0.56 (s, 18H,
H3C–Sn). 13C NMR (75.45 MHz, DMSO-d6, d, nJ [119Sn–13C] in Hz):
-2.3 (H3C–Sn); 131.6, 132.7, 139.6(C6Cl4); 169.7(COO). 119Sn
The 13C NMR data explicitly resolved the resonances of all the
distinct carbon atoms present in the compounds. The aromatic car-
bon resonances of the triphenyltin moieties are easily assigned on
the basis of both aromatic nJ [13C–119Sn] coupling constant(s) and
signal intensities. The aromatic carbon resonances were assigned
by comparison of experimental chemical shift with those calcu-
lated from incremental method [30]. The phenyl groups give sig-
nals in the expected ranges as earlier reports manifested [31].
NMR (DMSO-d6, d): ꢁ123.8. IR (KBr disc, cmꢁ1):
m
asym(COO) 1599,
sym(COO) 1318,
Dm = 220; m(Sn–C) 519, 559; m(Sn–O) 440; m(Ar–Cl) 1130.
mmsym(COO) 1412, dm = 187, masym(COO) 1538, m

3046
M. Khawar Rauf et al. / Journal of Organometallic Chemistry 693 (2008) 3043–3048
The 1J [13C–119Sn] coupling constant can be used to assess the coor-
dination number of the Sn atom in organotin compounds. The
coupling constants were calculated and found to be in the order
of 392.8 Hz for trimethyltin 1, 344 Hz for tributyltin 2 and
646 Hz for triphenyltin 3 compounds which are the characteristic
values for tetrahedral compounds as given in Table 3 [32,33]. An-
other characteristic feature for triphenyltin derivatives is the
observance of 13C chemical shift of the ipso-carbon at about
138 ppm which is attributed to a four coordinated tin atom [32].
The chemical shifts of the carboxylic carbon in these organotin
are observed in range 169–172 ppm in comparison to 181–
182 ppm in the ligands, confirming the coordination of the ligand
through carboxylic oxygen to the organotin(IV) moiety. The calcu-
lated value of the 1J [13C–119Sn] coupling constant for 5 and 6 are
520 and 794 Hz, respectively which described the penta coordi-
nated environment about the Sn atom in these compounds.
The 119Sn NMR data (in CDCl3) for 1–3 show a single resonance
at 140.6 ppm for trimethyltin compound 1, 114.7 ppm for tributyl-
tin compound 2 and ꢁ108.6 ppm for triphenyltin compound 3.
These values are in conformity to four coordination around the
Sn atom as reported earlier [31,32]. However, the d 119Sn NMR in
DMSO-d6 shows the coordination of the solvent through the oxy-
gen atom to the Sn atom, and the values are ꢁ123.8 ppm for tri-
methyltin derivative, ꢁ68.4 ppm for tributyltin and ꢁ174 ppm
for triphenyltin derivatives which confirms penta coordinated tin
geometry for compounds 4–6. This feature has been confirmed
by single crystal XRD studies when one of the compounds 4 was
crystallized in DMSO.
3.2. Crystal structures
3.2.1. Structure of 4 ꢀ 2DMSO
Fig. 1 shows an ORTEP representation of the molecular structure
for this complex, and the selected bond distances and angles are
listed in Table 2. There are two independent molecules in the
asymmetric unit, each having a slightly different geometry. For
the sake of simplicity and clarity, the geometry of one molecule
is discussed here. Each molecule contains two metal centers, each
of them surrounded by five atoms in a distorted trigonal bipyrami-
dal environment, where the ligand acts as a bridge between the
two metal atoms: as an O-donor ligand with respect to Sn(1) and
Sn(2). So that, the coordinating polyhedron around Sn(1) and
Sn(2) is formed by 2 oxygen atoms (one from DMSO and the other
one from the ligand) located on the apical positions of the bipyra-
mid and the three methyl carbon atoms in the equatorial sites [34].
A considerable distortion arises from the presence of the bridged
ligand, as indicated by the O(1)–Sn(1)–O(11) and O(2)–Sn(2)–
O(2) angle values [176.58(12)° and 178.22(13)° instead of the ex-
Table 2
Selected geometric parameters (Å, °) for 4 ꢀ 2DMSO
Bonds
Angles
Sn(1)–C(11)
Sn(1)–C(13)
Sn(1)–C(12)
Sn(1)–O(11)
Sn(1)–O(1)
Sn(2)–C(22)
Sn(2)–C(21)
Sn(2)–C(23)
Sn(2)–O(21)
Sn(2)–O(2)
Sn(1A)–C(11A)
Sn(1A)–C(13A)
Sn(1A)–C(12A)
Sn(1A)–O(71A)
Sn(1A)–O(1A)
Sn(2A)–C(22A)
Sn(2A)–C(21A)
Sn(2A)–C(23A)
Sn(2A)–O(81A)
Sn(2A)–O(2A)
2.123(6)
2.132(6)
2.142(6)
2.182(3)
2.470(3)
2.128(5)
2.134(6)
2.137(5)
2.208(3)
2.381(4)
2.125(6)
2.137(7)
2.141(6)
2.215(4)
2.451(6)
2.117(6)
2.127(6)
2.133(6)
2.193(3)
2.404(3)
C(21)–Sn(2)–C(23)
C(22)–Sn(2)–O(21)
C(21)–Sn(2)–O(21)
C(23)–Sn(2)–O(21)
C(22)–Sn(2)–O(2)
C(21)–Sn(2)–O(2)
C(23)–Sn(2)–O(2)
O(21)–Sn(2)–O(2)
C(7)–O(11)–Sn(1)
118.5(3)
98.42(18)
89.18(19)
93.08(19)
83.19(18)
89.4(2)
86.69(19)
178.22(13)
115.4(3)
116.3(3)
121.92(19)
122.0(2)
114.4(3)
130.0(3)
114.5(3)
94.2(2)
The characteristic IR bands of the compounds 1–6 have been
identified by comparing the data with the literature values
[27,28]. The vibrational absorptions of interest include:
550–586 cmꢁ1 (Sn–O), 440–486 cmꢁ1 and
(COO)asym, 1538–
1581 cmꢁ1 (COO)sym, 1318–1348 cmꢁ1. The mode of coordina-
tion of the carboxylate ligand to tin(IV) has been attributed to
the parameter d asym(COO)– sym(COO)]. The magnitude of d val-
m(Sn–C),
;
m
m
;
m
C(8)–O(21)–Sn(2)
S(1)–O(1)–Sn(1)
S(2)–O(2)–Sn(2)
m
[m
m
m
ues for these compounds lie in range 213–233 which described the
monodentate nature of the carboxylate group in these compounds.
The solid state structures for 2 and 4 were further confirmed by X-
ray crystallographic studies.
C(11A)–Sn(1A)–C(13A)
C(11A)–Sn(1A)–C(12A)
C(13A)–Sn(1A)–C(12A)
C(11A)–Sn(1A)–O(71A)
C(13A)–Sn(1A)–O(71A)
C(12A)–Sn(1A)–O(71A)
C(11A)–Sn(1A)–O(1A)
C(13A)–Sn(1A)–O(1A)
92.1(3)
94.0(2)
84.0(2)
91.2(3)
Angles
C(12A)–Sn(1A)–O(1A)
O(71A)–Sn(1A)–O(1A)
C(22A)–Sn(2A)–C(21A)
C(22A)–Sn(2A)–C(23A)
C(21A)–Sn(2A)–C(23A)
C(22A)–Sn(2A)–O(81A)
C(21A)–Sn(2A)–O(81A)
C(23A)–Sn(2A)–O(81A)
C(22A)–Sn(2A)–O(2A)
C(21A)–Sn(2A)–O(2A)
C(23A)–Sn(2A)–O(2A)
O(81A)–Sn(2A)–O(2A)
S(1A)–O(1A)–Sn(1A)
85.0(3)
C(11)–Sn(1)–C(13)
C(11)–Sn(1)–C(12)
C(13)–Sn(1)–C(12)
C(11)–Sn(1)–O(11)
C(13)–Sn(1)–O(11)
C(12)–Sn(1)–O(11)
C(11)–Sn(1)–O(1)
C(13)–Sn(1)–O(1)
C(12)–Sn(1)–O(1)
O(11)–Sn(1)–O(1)
C(22)–Sn(2)–C(21)
C(22)–Sn(2)–C(23)
125.5(3)
117.1(3)
115.7(2)
96.23(19)
95.79(18)
90.38(17)
84.36(19)
86.57(18)
86.36(17)
176.58(12)
118.0(3)
176.67(16)
122.9(3)
116.9(3)
118.9(3)
96.9(2)
94.93(19)
89.54(18)
85.1(2)
85.64(19)
87.67(18)
177.07(13)
127.4(3)
122.3(2)
Table 3
(C–Sn–C) angles (°) based on NMR parameters of some selected compounds
Number
Compound
1J [119Sn, 13C] (Hz)
2J [119Sn, 1H] (Hz)
h (°)
1J
2J
1
2
3
4
5
1
2
3
5
6
392.8
344
646
520
794
59
–
–
–
–
111
112
116
127
125
Fig. 1. ORTEP diagram of 4 ꢀ 2DMSO. Ellipsoids drawn at 30% probability.

M. Khawar Rauf et al. / Journal of Organometallic Chemistry 693 (2008) 3043–3048
3047
4.2. Antifungal activity
The agar tube dilution protocol method was employed to test
the antifungal activities of the synthesized compounds against
six types of fungi, namely Trichophyton longifusus, Candida albicans,
Aspergillus flavus, Candida glabrata, Fusarium solani and Mycobacte-
rium canis. The triorganotin derivatives of LB 4–6 Table 5 demon-
strated good antifungal activities against the enlisted fungal
species in comparison to the derivatives of LA 1–3. The fungicidal
activities of the compounds 1–3 were investigated and found that
compound 2 and 3 have comparable activities as reported earlier
[6,8]. The antifungal activities of compounds 4–6 were assessed
and found some encouraging results. The compound 5 have al-
ready been studied mostly against marine fouling organisms and
has been using in antifouling paints [10]. However present studies
described that the chloro-substituted organotins have broad activ-
ity spectrum against the enlisted species of fungi. The compound 6
was found to be more active in the series having 80–90% inhibition
of C. albicans, C. glabrata and F. solani, which is comparable to the
standard drug. The compounds 2 and 5 show moderate activity
against the M. canis. A limited structure activity relationship re-
vealed that the nature and position of substituent in the benzene
ring is critical for displaying the antifungal activity, as the com-
pounds containing chloro-substituted phenyl ring are found to be
more active than the compounds having hydroxyl substituted phe-
nyl ring. The order of activities of the synthesized compounds were
Fig. 2. ORTEP diagram of 3 [35]. Ellipsoids drawn at 30% probability.
pected 180°]. In the same way, bond angles in the equatorial plane
take values slightly different from 120° [C–Sn(1)–C; 115.7(2)°,
117.1(3)°, 125.5(3)°, C–Sn(2)–C; 118.0(3)°, 118.5(3)°, 122.3(2)°],
whereas the angles between the apical positions and the equatorial
plane have the values such as 84.36(19)° or 96.23(19)° for
C–Sn(1)–O and 83.19(18)° or 98.42(18)° for C–Sn(2)–O.
3.2.2. Structure of [(SnPh3)(OOCC6H4OH)] (3)
Fig. 2 shows an ORTEP representation of this complex [35],
redetermined at low temperature with greater number of reflec-
tions collected/used and high degree of completeness of h, submit-
Table 4
Anti-bacterial activity dataa,b of organotin(IV) derivatives 1–6
ted to the Cambridge Structural Database as
a
Private
Name of bacterium
Zone of inhibition (mm)
Ligands
LA LB
13 11 20
Ref. drugc
communication [36]. Some crystallographic data of 3 are presented
here solely for comparison purposes. The asymmetric unit contains
a single SnPh3 moiety connected to a 2-hydroxybenzoate ligand
through Sn(1)–O(1) bond. Sn(1) atom is surrounded by three phe-
nyl C atoms and one ligand O atom resulting a distorted tetrahe-
dron. The sum of the angles subtended at Sn(1) atom by the
three phenyl C(C21, C31, C41) and the ligand O(O1) atom is
437.22°, which is close to the ideal value (436.20°) for a regular tet-
rahedron. The dihedral angle constituted by the salicylate plane
[O(1), C(1), C(11), O(2)] with SnPh3 plane[C(21), C(31), C(41),
Sn(1)] is 82.5°. The hydroxyl H(12) atom makes an intramolecular
H-bond with the carbonyl oxygen O(2). The co-planarity of the
O(12), C(12), C(11), C(1), O(2) moiety with phenyl ring [C(11),
C(12), C(13), C(14), C(15), C(16)] salicylate group is associated with
the intramolecular hydrogen bond [O(12)–H(12)ꢀ ꢀ ꢀO(2)], as indi-
cated by the torsional angles O(2)–C(1)–C(11)–C(12), 3.515° and
C(1)–C(11)–C(12)–O(12), 6.1(5)°.
1
2
3
4
5
6
Bacillus subtilis
Escherichia coli
Pseudomonas aeroginosa
Staphylococcus auerus
Salmonella typhi
17 19 11 14 10
18 13 18 13 15 17 30
13 20 20 19 17 20 25 46
12 18 22 27 21 19 29 40
31
–
–
–
10
18 15 21 23 21 23 25 24 33
– 13 23 21 22 25 17 21 41
Shigella flexneri
(–) No activity.
a
In vitro.
b
Concentration = 2 mg/ml of DMSO, colony forming unit (CFU) ml = 104–106,
size of well = 6 mm (diameter).
c
Standard drug = Imipenum.
Table 5
Anti-fungal activity dataa,b,c of organotin(IV) derivatives 1–6
Name of fungi
Percent inhibition
Standard drug *MIC
(l
g mlꢁ1
)
4. Biological studies
Ligands
1
2
3
4
5
6
LA LB
4.1. Antibacterial activity
Trichophyton
longifusus
30 46 40 42 45 62 67 70 70
The compounds 1–6 were tested by agar well diffusion method
and the results are presented in Table 4. The activity of these com-
pounds against six different types of bacteria namely Bacillus sub-
tilis, Escherichia coli, Pseudomonas aeroginosa, Staphylococcus auerus,
Salmonella typhi and Shigella flexneri were studied using Imipenum
as a reference drug. The bactericidal activity of 2 and 3 are fairly
good except E. coli and P. aeroginosa as earlier reports demon-
strated [6,7], the same is true for 1. The antibacterial studies of
the compounds show relatively better activity against various bac-
teria than the free ligands but low activity in comparison to the ref-
erence drug.
Candida albicans 40 54 45 44 65 60 67 90 110
Aspergillus
flavus
36 48 45 40 42 58 69 72 30
Candida glabrata 35 57 45 49 58 73 78 85 111
Fusarium solani
Mycobacterium
canis
42 51 41 48 63 71 74 87 74
42 53 45 55 57 56 54 67 98
a
In vitro.
Concentration of sample = 100
Standard drug = Miconazole and Amphotericin
b
l
g/ml of DMSO.
c
B
(for A. flavis), percent
inhibition = 100.
*
MIC, minimum inhibitory concentration.

3048
M. Khawar Rauf et al. / Journal of Organometallic Chemistry 693 (2008) 3043–3048
[12] C. Cox, J. Pest. Reforms 17 (1997) 4.
[13] D.P. Bruynzeel, W.G. Van Ketal, Contact Dermat. 14 (1986) 67.
[14] R.B. Johnson, Florida Entomol. 49 (1966) 195.
found to be as follows; triphenyltin derivatives > tributyltin deriv-
atives > trimethyltin derivatives.
[15] H. Penagos, Contact Dermat. 35 (1986) 214.
[16] (a) M.A. Saeed, D.C. Craig, A. Badshah, S. Ali, M.K. Rauf, Acta Crystallogr. E61
(2005) m2595;
Acknowledgment
(b) M. Parvez, S. Anwar, A. Badshah, B. Ahmad, A. Majeed, M. Ashfaq, Acta
Crystallogr. C56 (2000) 159.
[17] Imtiaz-ud-Din, M. Mazhar, K.C. Molloy, K.M. Khan, J. Organomet. Chem. 691
(2006) 1643.
Authors are thankful to the Higher Education Commission of
Pakistan for financial support.
[18] G. Sabitha, R. Srividya, J.S. Yadav, Tetrahedron 55 (1999) 4015.
[19] D.D. Parrin, W.L.F. Armarega, Purification of Laboratory Chemicals, third ed.,
Butterworth Heinemann, Oxford, 1997.
Appendix A. Supplementary material
[20] Stoe & Cie. X-AREA. Stoe & Cie, Darmstadt, Germany, 2001.
[21] A. L Spek, J. Appl. Crystallogr. 36 (2003) 7.
[22] G.M. Sheldrick, SHELXS-97 and SHELXL-97. University of Göttingen, Germany,
1997.
[23] G.M. Sheldrick, SHELXTL-Plus. Release 4.1. Siemens Analytical X-ray Instruments
Inc., Madison, Wisconsin, USA, 1991.
[24] J.D. Paxton, Meth. Plant Biochem. 6 (1991) 33.
[25] Atta-ur-Rehman, M.I. Choudhary, W.J. Thomson, Bioassay Techniques for Drug
Development, Harward Academic Publishers, Amsterdam, 2001.
[26] P.J. Smith, R.O. Day, V. Chandrasekhar, J.M. Holmes, R.R. Holmes, Inorg. Chem.
25 (1986) 2495.
CCDC 607279 and 681174 contains the supplementary crystal-
lographic data for 3 and 4 ꢀ 2DMSO. These data can be obtained free
of charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif. Supplementary data associ-
ated with this article can be found, in the online version, at doi:
10.1016/j.jorganchem.2008.06.027.
References
[27] Imtiaz-ud-Din, M. Mazhar, K.C. Molloy, Main Group Met. Chem. 29 (2006) 11.
[28] Imtiaz-ud-Din, M. Mazhar, S. Ali, K.M. Khan, Nat. Prod. Res. 21 (2007) 749.
[29] T.P. Lockhart, W.F. Manders, E.M. Holt, J. Am. Chem. Soc. 108 (1986) 6611.
[30] H.O. Kolinowski, S. Berger, S. Brown, 13C NMR Spektroscopie, Thieme-Verlag,
Stuttgart, Germany, 1984.
[31] M. Gielen, A. El-Khloufi, M. Biesemans, F. Kayser, R. Willem, Appl. Organomet.
Chem. 7 (1993) 20.
[32] R. Willem, A. Bouhdid, M. Biesemans, J.C. Martins, D. Vos, E.R.T. Tiekink, M.
Gielen, J. Organomet. Chem. 514 (1996) 203.
[1] (a) L. Pellerito, L. Nagy, Coord. Chem. Rev. 224 (2002) 111;
(b) A. Meriem, R. Willem, M. Biesemans, B. Mahieu, D. devos, P. Lelieveld, M.
Gielen, Appl. Organomet. Chem. 5 (1991) 195.
[2] A. Bianco, N. Ucella, Food Res. Int. 33 (2000) 475.
[3] K. Yoon, C. Jeong-Yong, K. Ju-Hee, Curr. Microbiol. 48 (2004) 312.
[4] R. Cini, R. Comments, Inorg. Chem. 22 (2000) 151. and references therein;
(a) C. Rice-Evan, N. Miller, G. Paganga, Free Radic. Biol. Med. 20 (1996) 933;
(b) K.V. Marileno, Breast Cancer Res. 6 (2004) R63.
[33] J. Holecek, M. Nadvornik, K. Handlir, J. Organomet. Chem. 241 (1983) 177.
[34] P. Alvarez-Boo, J.S. Casas, M.D. Couce, R. Farto, V.F. Moreira, E. Freijanes, J.
Sordo, E. Vazquiel-Lopez, J. Organomet. Chem. 691 (2006) 45.
[35] J.F. Vollano, R.O. Day, D.N. Rau, V. Chandrasekhar, R.R. Holmes, Inorg. Chem. 25
(1986) 2495.
[36] M.K. Rauf, A. Badshah, M. Bolte, M.A. Saeed, Imtiaz-ud-Din, B. Mirza, Private
Communication to the Cambridge Structural Database, Deposition Number
CCDC 607279, 2008.
[5] K. Herrmann, Crit. Rev. Food Sci. Nutr. 28 (1989) 315.
[6] A.J. Nok, M.N. Shuaibu, J.J. Bonire, A. Daho, Z. Wushishi, S. Ado, J. Enzyme
Inhibit. 15 (2000) 411.
[7] A.J. Nok, H.I. Nock, J.J. Bonire, Appl. Organomet. Chem. 17 (2003) 17.
[8] T.N. Srivastava, B. Srivastava, M.C. Bhatia, Acta Ciencia Indica 3 (1977) 306.
[9] A.J. Crowe, R. Hill, P.J. Smith, T.R.G. Cox, Wood Preserv. 1 (1996) 156.
[10] (a) A. Fargasova, J. Kizlink, Ecotoxicol. Environ. Safe. 34 (1996) 156;
(b) A. Fargasova, Ecotoxicol. Environ. Safe. 41 (1998) 222.
[11] M.N. Clifford, J. Sci. Food Agric. 80 (2000) 1033.