Asian Journal of Chemistry; Vol. 25, No. 2 (2013), 972-976
Synthesis and Characterization of Organotin(IV) Complexes Derivatives of Methyl- and Nitro-
Substituted Monocarboxylic Acid: Preliminary in vitro Antibacterial Screening Activity
1
1
2,3
YIP-FOO WIN1,2,*, CHEN-SHANG CHOONG , SIE-TIONG HA , SIANG-GUAN TEOH2,* and NASER ELTAHER ELTAYEB
1Department of Chemical Science, Faculty of Science, Universiti TunkuAbdul Rahman, Perak Campus, Jalan Universiti, Bandar Barat, 31900
Kampar, Perak, Malaysia
2School of Chemical Sciences, Universiti Sains Malaysia, 11800 Minden Penang, Pulau Pinang, Malaysia
3Department of Chemistry, Faculty of Pure and Applied Sciences, International University of Africa, Khartoum, Sudan
*Corresponding author: Fax: +60 5 4661676; Tel: +60 5 4688888; E-mail: williamyfw@yahoo.com
(Received: 20 December 2011;
Accepted: 27 August 2012)
AJC-12024
Organotin(IV) carboxylate complexes derivatives of 3-methyl-4-nitrobenzoic acid (3-CH3-4-NO2-C6H3COOH) and 4-methyl-3-nitrobenzoic
acid (4-CH3-3-NO2-C6H3COOH) have been successfully synthesized. Two dibutyltin(IV) complexes with the general formulae {[X-CH3-
Y-NO2-C6H3COO(C4H9)2Sn]2O}2 (X = meta, Y = para 1; X = para, Y = meta 3) and another two triphenyltin(IV) complexes with the
general formulae X-CH3-Y-NO2-C6H3COO(C6H5)3Sn·CH3OH (X = meta,Y = para 2; X = para,Y = meta 4) were successfully synthesized.
The acids and complexes 1-4 obtained were characterized quantitatively and qualitatively. Results of the infrared and NMR spectroscopy
on the acids and complexes showed that the coordination took place via oxygen atoms from the carboxylate anions. Based on the
spectroscopy studies indicated that one methanol molecule also take part in the coordination to tin(IV) atoms moiety in complexes 2 and
4 resulting the tin(IV) atoms exhibited five coordination. From the preliminary in vitro antibacterial screening activity, triphenyltin(IV)
complexes (2 and 4) showed better activity compared to diorganotin(IV) complexes (1 and 3).
Key Words: Organotin(IV) complexes, Synthesis, Characterization, In vitro antibacterial activity.
known quantity of each complex to SnO2. Infrared spectra
were recorded using a Perkin-Elmer System 2000 FTIR
spectrophotometer as a KBr disc in the frequency range of
INTRODUCTION
Numerous studies on organotin(IV) complexes have been
carried out in order to study its biological properties against
bacterial, fungal and cancer cells line1-8. In fact, organotin(IV)
complexes are extensively studied due to its coordination
geometries as well as structural diversity (monomer, dimeric,
1
4000-400 cm-1. The spectra for H, 1H-13C HMQC and 119Sn
NMR were recorded on a Bruker AC-P 400 MHz FTNMR
spectrometer and 13C NMR was recorded on a Bruker AC-P
300MHz FTNMR spectrometer using deuterated CDCl3 and
DMSO-d6 as the solvent and tetramethylsilane, TMS as the
internal standard.
hexameric and oligomeric)9-13
.
In this paper, we report on the synthesis and structural
characterization of new organotin(IV) carboxylate complexes
derived from 3-methyl-4-nitrobenzoic acid and 4-methyl-3-
nitrobenzoic acid. Moreover, the preliminary in vitro antibac-
terial screening activity of the complexes obtained are carried
out and the results are reported herein.
Preliminary in vitro antibacterial screening activity:
The synthesized complexes and parent acids were screened
for their in vitro antibacterial activity against three Gram-
negative (Escherichia coli, Pseudomonas aeruginosa and
Klebsiella pneumoniae) and two Gram-positive (Bacillus
subtilis and Staphylococcus aureus) bacterial strains, by inhi-
bition zone method using agar well diffusion method. The
seeded agar (nutrient agar medium) was prepared by cooling
the molten agar to 40 ºC and then adding bacterial inoculums
containing approximately 104-106 colony forming units (CFU)/
mL. The bacterial inoculums were spread on the plate conta-
ining agar medium and even coverage was ensured before the
agar solidified. The complexes were dissolved in DMSO to
EXPERIMENTAL
All the reagents, starting materials as well as the solvents
were purchased commercially and used without any further
purification. The melting points were determined in an open
capillary and were uncorrected. Elemental C, H and N analyses
were carried out on a Perkin-Elmer 2400 CHN Elemental
Analyzer. Tin was determined gravimetrically by igniting a
Win, Yip-Foo
