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N. Kourkoumelis et al. / Spectrochimica Acta Part A 60 (2004) 2253–2259
and a 5 mm 13C/1H dual probe head H 90◦ pulse width
= 10.2 s, 13C 90◦ pulse width = 10.4 s). Samples were
dissolved in CDCl3 or DMSO-d6 and spectra were obtained
at room temperature with the signal of the free DMSO
or CHCl3 (at 2.49 and 7.24 ppm correspondingly) as a
reference. Mössbauer measurements were carried out us-
ing a constant-acceleration. Mössbauer spectrometer with
a Ba119SnO3 source maintained at room temperature. A
Pd filter was used to eliminate the 25.8 keV×radiation. A
variable-temperature liquid-nitrogen cryostat (Oxford In-
struments) was used for the low temperature measurements.
Suitable computer programs have been employed in the fit-
ting procedure of the experimental spectra using Lorentzian
1
Scheme 1.
Organotin(IV) carboxylates form an important class of
compounds and have been receiving increasing attention in
recent years, not only because of their intrinsic interest but
owing to their varied applications. Some examples find wide
use as catalysts and stabilizers, and certain derivatives are
used as biocides, as anti-fouling agents and as wood preser-
vatives [9]. Information on the structures of organotin car-
boxylates continues to accumulate, and at the same time
new applications of such compounds are being discovered
in industry, ecology, and medicine. In recent years, investi-
gations have been carried out to test their anti-tumor activ-
ity and it has been observed that indeed several diorganotin
species, as well as triorganotin species, show potential as
anti-neoplastic agents [10] and anti-tuberculosis agents [11].
Given the pharmacological importance of sodium di-
clofenac and the potential biological activity of organotin
carboxylates, it was thought of some interest to explore the
chemistry of organotin/diclofenac compounds. The novel
complexes [R2(L)SnOSn(L)R2]2 (where R = CH3, Ph)
and [R2SnL2] (where R = Bu) have been prepared and
structurally characterized in the solid state by means of
119Sn Mössbauer spectroscopy, the determination of lattice
dynamics by temperature-dependent 119Sn Mössbauer spec-
line shapes. The estimated errors are
for the hyperfine parameters and 3% for the spectral
areas.
0.02 mm s−1
2.2. Synthesis
To a solution of dimethyltin oxide (0.198 g, 1.2 mmol)
in benzene (20 ml) was added a solution of diclofenac acid
(0.296 g, 1 mmol) in benzene (10 ml). The reaction mixture
was refluxed for 3 h with azeotropic removal of water via a
Dean-Stark trap (caution: benzene is very toxic). The result-
ing clear solution was rotary evaporated under vacuum to
a small volume, chilled, and triturated with diethylether to
give a white solid; m.p. 195–197 ◦C. Anal. found: C, 42.25;
H, 4.07; N, 2.97. Calculated: C, 42.44; H, 3.53; N, 3.09.
2.2.2. [Bu2SnLOLSnBu2]2, (2)
2 was prepared according to published procedure [8].
m.p. 146–147 ◦C. Anal. found: C, 49.20; H, 5.21; N, 2.61.
Calculated: C, 49.30; H, 5.26; N, 2.61.
1
troscopy and by vibrational and H and 13C NMR studies.
2.2.3. [Bu2SnL2], (3)
2. Experimental
To a solution of di-n-butyltin oxide (0.2489 g, 1 mmol)
in benzene (20 ml) was added a solution of diclofenac
acid (0.65 g, 2.2 mmol) in benzene (10 ml). The reaction
mixture was refluxed for 3 h with azeotropic removal of
water via a Dean-Stark trap. The resulting clear solution
was rotary evaporated under vacuum to a small volume,
chilled and triturated with diethylether to give a white solid;
m.p. 103–104 ◦C. Anal. found: C, 52.03; H, 4.76; N, 3.62.
Calculated: C, 52.52; H, 4.62; N, 3.40.
2.1. General considerations
The reagents (Aldrich, Merck) were used as-supplied
while the solvents were purified according to standard
procedures. Sodium diclofenac was a gift from “HELP
A.E”. C, H, and N analyses were carried out by the mi-
croanalytical service of the University of Ioannina. Melting
points were determined in open capillaries and are un-
corrected. Infrared and far-infrared spectra were recorded
on a Nicolet 55XC Fourier transform spectrophotometer
using KBr pellets (4000–400 cm−1) and nujol mulls dis-
persed between polyethylene disks (400–40 cm−1). The
1H (250.13 MHz), 13C (62.90 MHz), 2D 1H–1H shift
correlated spectra (COSY), 2D 13C–1H shift correlated
spectra (HETCOR) and 2D long range 13C–1H shift cor-
related spectra (COLOC) NMR spectra were recorded on
a Bruker AC-250E spectrometer equipped with an Aspect
3000 computer (using DISNMR program, version 1991)
2.2.4. [Ph2SnLOLSnPh2]2, (4)
To a solution of diphenyltin oxide (0.332 g, 1.15 mmol)
in benzene (20 ml) was added a solution of diclofenac acid
(0.296 g, 1 mmol) in EtOH (10 ml) and were refluxed for 4 h
with azeotropic removal of water via a Dean-Stark trap. The
resulting clear solution was rotary evaporated under vacuum
to a small volume, chilled and triturated with diethylether
to give a white solid; m.p. 101–104 ◦C. Anal. found: C,
54.12; H, 3.65; N, 2.45. Calculated: C, 54.22; H, 3.50; N,
2.43.