JSCS Vol 73, No. 1
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J. Serb. Chem. Soc. 73 (1) 1–6 (2008)
UDC
547.979.732+542.9+547.571+547.551:547.538:537.872; JSCS–3682;
doi: 10.2298/JSC0801001W; Original
scientific paper
Synthesis and characterization of novel porphyrin
Schiff bases
LEI WANG, YAQING FENG, JINQIANG XUE and YUKUN LI
School of Chemical Engineering and Technology, Tianjin
University, Tianjin 300072, China
(Received
Novel porphyrin Schiff bases were synthesized by a
simple Schiff base condensation in refluxing toluene between
5-(4-AMinophenyl)-10,15,20-triphenylporphyrin (ATTP) 3 and styryl
aldehydes 4–6 or p-halobenzaldehydes 7–9.
The newly synthesized porphyrin Schiff bases were characterized on the basis of
their chemical properties and spectral data. A good intrAMolecular energy
transfer from the styryl unit to the porphyrin moiety
was found.
Keywords: porphyrin Schiff base; styryl;
energy transfer.
Full Article - PDF 242 KB
J. Serb. Chem. Soc. 73 (1) 7–13 (2008)
UDC
547.754+547.367+547.497:615.281/.282:615.276; JSCS–3683; doi: 10.2298/JSC0801007K; Original scientific paper
Antimicrobial activity of some isatin-3--thiosemicarbazone complexes
SANDRA S. KONSTANTINOVIC, BLAGA C. RADOVANOVIC*, SOFIJA P. SOVILJ** and
SVETLANA STANOJEVIC***
Faculty of Technology, Bulevar Oslobodjenja
124, 16000 Leskovac, Serbia
*Department of Chemistry, Faculty of Science, Visegradska 33, 18000
**Faculty of Chemistry,
***
(Received
Isatin-3-thiosemicarbazone complexes with Co(II), Ni(II), Cu(II), Zn(II), Hg(II) and Pd(II) were
synthesized and evaluated for their antimicrobial activity against 7 pathogenic
bacteria and 4 fungi. The complexes have an enhanced activity compared to the
ligand due to transition metal involved in coordination. The anti-AMoebic
activity in vitro was evaluated against the HM1:IMSS
strain of EntAMoeba histolytica
and the results were compared with the standard drug, metronidazole. The
preliminary test results showed that the complexes had better anti-AMoebic
activity than their respective ligands. Moreover, the complexes showed better
inhibition of the test organism.
Keywords: isatin-3-thiosemicarbazone complex; antibacterial activity;
antifungal activity; anti-inflAMmatory activity; anti-AMoebic activity.
Full Article - PDF 213 KB
J. Serb.
Chem. Soc. 73 (1) 15–27 (2008)
UDC
547.912+535–31+547.216+544.35:66.022.362; JSCS–3684; doi:
10.2298/JSC0801015C; Original scientific paper
Stability of carotenoids toward
UV-irradiation in hexane solution
DRAGAN CVETKOVIC and DEJAN MARKOVIC
Faculty of Technology, University of Nis, Bulevar oslobodjenja 124, 16000 Leskovac,
Serbia
(Received 12 January 2007, revised 8
August 2007)
The stabilities
of four selected carotenoids dissolved in hexane, two carotenes and two
xanthophylls, toward UV-irradiation of three different ranges (UV-A, UV-B and
UV-C) were studied in this work. The carotenoids underwent bleaching via a probable free radical mediated
mechanism following first-order kinetics. The bleaching rates were highly
dependent on the input of the involved photons and, although not consistently,
on the chemical structures of the investigated compounds. For the two xanthophylls,
a possible role of oxygen associated with their bleaching cannot be neglected.
Keywords:
carotenoids; UV-irradiation; free radicals; bleaching; kinetics.
Full Article - PDF 262 KB Supplementary
Material - PDF 496 KB
J. Serb. Chem. Soc. 73 (1) 29–39 (2008)
UDC 547.831+546.650:66.061:620.168.3;
JSCS–3685; doi: 10.2298/JSC0801029A; Original scientific paper
Crown ethers as synergistic agents in
the solvent extraction of trivalent lanthanides with 8-hydroxyquinoline
M. ATANASSOVA
University of Chemical Technology and Metallurgy, Department of General and
Inorganic Chemistry, 8 Kl. Okhridski, 1756, Sofia,
Bulgaria
(Received 17 July 2006)
The liquid extraction of the 13 lanthanides with
mixtures of 8-hydroxyquinoline (HQ) and crown ethers (S) dibenzo-18-crown-6
(DB18C6) and dibenzo-24-crown-8 (DB24C8) in 1,2-dichloroethane as a diluent
from chloride medium at constant ionic strength μ = 0.1 was investigated. The
composition of the extracted species was established as LnQ3 with HQ
alone and as LnQ3·S in the presence of a crown ether. The values of
the equilibrium constants were calculated. The addition of DB18C6 to the metal
chelate system improved the extraction efficiency, while a weak synergistic
enhancement was found when the metals were extracted with mixtures of
HQ–DB24C8. The parAMeters of the extraction process were determined and the
separation factors between two adjacent lanthanides(III)
were calculated.
Keywords: synergistic extraction; 8-hydroxyquinoline;
dibenzo-24-crown-8; dibenzo-18-crown-6; lanthanides separation factors.
Full Article - PDF 274 KB
UDC 531.3+54.02:539.193:536.7;
JSCS–3686; doi: 10.2298/JSC0801041R; Original scientific paper
On the dynAMics of some small structural motifs in rRNA upon ligand binding
ALEKSANDRA RAKIC
and PETAR M. MITRASINOVIC*
Faculty of
Physical Chemistry,
*Center for
Multidisciplinary Studies,
(Received
The present study characterizes using molecular
dynAMics simulations the behavior of the GAA (1186–1188) hairpin triloops with their closing c–g base pairs in large ribonucleoligand complexes (PDB IDs: 1njn, 1nwy, 1jzx). The
relative energies of the motifs in the complexes with respect to that in the
reference structure (unbound form of rRNA; PDB ID:
1njp) display the trends that agree with those of the conformational parAMeters
reported in a previous study utilizing the de novo pseudotorsional
(η,θ) approach. The
RNA regions around the actual RNA–ligand contacts, which experience the most
substantial conformational changes upon formation of the complexes were
identified. The thermodynAMic parAMeters, based on a two-state conformational
model of RNA sequences containing 15, 21 and 27 nucleotides in the immediate
vicinity of the particular binding sites, were evaluated. From a more
structural standpoint, the strain of a triloop, being
far from the specific contacts and interacting primarily with other parts of
the ribosome, was established as a structural feature which conforms to the
trend of the average values of the thermodynAMic variables corresponding to the
three motifs defined by the 15-, 21- and 27-nucleotide sequences. From a more
functional standpoint, RNA–ligand recognition is suggested to be presumably
dictated by the types of ligands in the complexes.
Keywords:
rRNA; ligand binding; small motifs; molecular
dynAMics; thermodynAMics.
Full Article - PDF 431 KB Supplementary Material - PDF 178 KB
UDC 546.881–31+546.77–31+547.214:544.4; JSCS–3687; doi:
10.2298/JSC0801055M; Original scientific paper
Selective oxidation of isobutane on V–Mo–O mixed
oxide catalysts
GHEORGHITA MITRAN, IOAN–CEZAR MARCU, TATIANA
YUZHAKOVA* and IOAN SANDULESCU
Department of Chemical
Technology and Catalysis,
*Department of Environmental
Engineering and Chemical Technology, Faculty of Engineering, Pannon University, 10 Egyetem
St., H-8201,
(Received
Four V–Mo–O mixed metal oxides were
prepared, characterized and tested for the selective oxidation of isobutane in the temperature range 350–550 °C, at
atmospheric pressure. Isobutane was mainly oxidized
to iso-butene and carbon oxides. The systems with low
vanadium contents showed low activities but high isobutene selectivities,
while the systems with high vanadium contents showed high activities with high
carbon oxides selectivities. The effects of
temperature, contact time and the molar ratio iso-butane
to oxygen on the conversion of isobutane and the
selectivity of the oxidation were studied.
Keywords: vanadium molybdenum
oxides; iso-butane oxidation; iso-butene.
Full Article - PDF 232 KB
J. Serb. Chem. Soc. 73 (1) 65–71 (2008)
UDC
541.182.45:544.112+519.233.2:546.86–31+546.86'18; JSCS–3688; doi: 10.2298/JSC0801065R; Original
scientific paper
Molecular parAMeters for the gas phase
molecules SbO and SbP
P. SRI RAMACHANDRAN, V. RAJA* and N. RAJAMANICKAM
Physics Research Centre,
*Department of Physical
Chemistry,
(Received
Franck–Condon factors and r-centroids,
which are very closely related to relative vibrational transition
probabilities, were evaluated by the numerical integration procedure for the
bands of the A2Π3/2 – X2Π3/2, C2Σ – X2Π3/2 and D2Π
– X2Π systems of the isotopic SbO molecule
and for the B1Π – X1Σ+ system of the isotopic SbP molecule, using a suitable potential.
Keywords: Franck–Condon factors; r-centroids and isotopic molecule SbO and
SbP molecules.
Full Article - PDF 206 KB
J. Serb. Chem. Soc. 73 (1)
73–85 (2008)
UDC
547.261'122.6+547.534.2:532.11'13'14:539.121.62; JSCS–3689; doi: 10.2298/JSC0801073C; Original scientific paper
Vapor pressure, density,
viscosity and refractive index of dimethyl sulfoxide + 1,4-dimethylbenzene
system
OANA CIOCIRLAN and OLGA IULIAN
Department of Applied Physical Chemistry and
Electrochemistry, Faculty of Industrial Chemistry, “Politehnica”
(Received
This paper reports the
experimental results of isothermal vapor–liquid equilibrium data between 303.15
and 333.15 K, and densities, viscosities, refractive indices from 298.15 to
323.15 K of the dimethyl sulfoxide + 1,4-dimethylbenzene system over the entire
range of mixture composition. The obtained PTX data were correlated by the
Wilson and NRTL models and estimated by the UNIFAC model. The excess Gibbs
energy and activity coefficients were calculated and compared with others
excess properties. Excess molar volumes, viscosity deviations and deviations in
refractivity were calculated from the experimental data; all the computed
quantities were fitted to the Redlich–Kister
equation. The resulting excess functions were interpreted in terms of structure
and interactions.
Keywords: dimethyl sulfoxide; 1,4-dimethylbenzene;
VLE data; density; viscosity; excess properties.
Full Article - PDF 287 KB
J. Serb. Chem. Soc. 73 (1)
87–95 (2008)
UDC
543.544:*ibuprofen+*indomethacin+*naproxen:547.288.1; JSCS–3690, doi: 10.2298/JSC0801087A; Original scientific paper
Potentiometric
determination of ibuprofen, indomethacin and naproxen using an artificial
neural network calibration
A. HAKAN AKTAŞ and GÜZIDE
PEKCAN ERTOKUŞ
Department of Chemistry,
Faculty of Science &AMp; Art,
(Received
In this study, three
anti-inflAMmatory agents, nAMely ibuprofen, indomethacin and naproxen, were
titrated potentiometrically using tetrabutylAMmonium
hydroxide in acetonitrile solvent under a nitrogen atmosphere at 25 °C. MATLAB
7.0 software was applied for data treatment as a multivariate calibration tool
in the potentiometric titration procedure. An artificial neural network (ANN)
was used as a multivariate calibration tool in the potentiometric titration to
model the complex non-linear relationship between ibuprofen, indomethacin and
naproxen concentrations and the millivolt (mV) of the solutions measured after
the addition of different volumes of the titrant. The optimized network
predicted the concentrations of agents in synthetic mixtures. The results
showed that the employed ANN can precede the titration data with an average
relative error of prediction of less than 2.30 %.
Keywords: anti-inflAMmatory agents; potentiometric
titration; artificial neural network (ANN).
Full Article - PDF 416 KB
J. Serb. Chem. Soc. 73 (1)
97–111 (2008)
UDC
546.284–31:539.23:621.928.46+542.9+543.4; JSCS–3691; doi:
10.2298/JSC0801097S; Original scientific paper
The charge percolation
mechanism and simulation of Ziegler–Natta polymerizations.
Part VII.
Effects of the distribution of chromium active centers on silica on the
polymerization of ethylene
DRAGOSLAV STOILJKOVIC,
BRANKA PILIC, MISA BULAJIC*, NEBOJSA DJURASOVIC* and NIKOLAJ OSTROVSKII**
Faculty of Technology,
*HIP-Petrohemija,
26000 Pancevo, Serbia
**HIPOL, 25250 Odzaci, Serbia
(Received 22 September
2006, revised 13 June 2007)
The charge percolation
mechanism (CPM) of olefin polymerization in the presence of transition metal
compounds has been applied to explain the polymerization of ethylene by silica
supported chromium oxide. In the previous work of this series, the fundAMental
issues and mechanism of this polymerization were presented. In this work the
compatibility of the CPM with the empirical findings is confirmed. The CPM has
been applied to explain: the appearance of an induction period; the
deactivation of active centers and the formation of oligomers; the effects of
chromium concentration on the silica surface, the silica surface discontinuity
and the pore size of silica on polymerization and the formation of the
structure of polyethylene. A mathematical model has been derived to explain the
effects of the CrOx/SiO2 ratio on the productivity of
Phillips catalysts in the polymerization of ethylene. The empirical findings
have also been confirmed by computer simulations.
Keywords: ethylene polymerization; Phillips CrOx/SiO2;
charge percolation mechanism.
Full Article - PDF 296 KB
J. Serb. Chem. Soc. 73 (1)
113–119 (2008)
UDC
539.42:669.141.24:669.112.227:539.3/.5:669; JSCS–3692; doi: 10.2298/JSC0801113G; Original scientific paper
Influence of
cooling conditions and AMount of retained austenite on the fracture of austempered ductile iron
VYACHESLAV GORYANY, ECKART
HOFMANN and PAUL JOSEF MAUK
Institute of Applied
Materials Technology (IAM), University of Duisburg-Essen, D-47048
(Received 27 December 2005)
SEM Analysis of fracture
surfaces from tensile test specimens of thick-walled, austempered
ductile irons (diAMeter 160 mm) shows different
fracture behavior depending on the austenite retained in the matrix. The
results show ductile fractures only in areas containing retained austenite
sections. In section areas without or with a very low content of retained
austenite, only brittle fracture without any plastic deformation occurs. The
content of retained austenite determines the AMount of ductile fracture in the
microstructure.
Keywords: austempered ductile
iron; retained austenite; fracture mechanism.
Full Article - PDF 2.291 KB
J. Serb. Chem. Soc. 73 (1)
121–126 (2008)
UDC
546.284–31:539.23:621.928.46+542.9+543.4; JSCS–3693; doi:
10.2298/JSC0801121R; Original scientific paper
Reactive
sputtering deposition of SiO2 thin films
IVAN RADOVIC, YVES
SERRUYS*, YVES LIMOGE* and NATASA BIBIC
Vinca Institute of Nuclear
Sciences,
*CEA/Saclay, Section de Recherches de
Métallurgie Physique, 91191 Gif sur Yvette Cedex,
France
(Received
SiO2 layers were
deposited in a UHV chAMber by 1 keV
Ar+ ion sputtering from a high purity
silicon target, using different values of the oxygen partial pressure (5×10-6–2×10-4
mbar) and of the ion beAM current on the target (1.67–6.85 mA). The argon
partial pressure during operation of the ion gun was 1×10-3 mbar.
The substrate temperature was held at 550 °C and the films were deposited to a
thickness of 12.5–150 nm, at a rate from 0.0018–0.035 nm s-1.
Structural characterization of the deposited thin films was performed by
Keywords: SiO2; thin films; reactive
sputtering; RBS analysis.
Full Article - PDF 210 KB
J. Serb. Chem. Soc. 73 (1)
127–129 (2008)
UDC
547.93:54+542.913.000.57+543+615; JSCS–3694; Book review
BOOK REVIEW
BILE ACIDS
Chemistry,
biosynthesis, analysis, chemical and metabolic transformations and pharmacology
Editors: M. MIKOV and J. P.
FAWCETT; Published by Mediset Publisher, Geneva,
Switzerland, 2007, ISBN 0-12-045783-2
Authors: M. MIKOV, J. P.
FAWCETT, K. KUHAJDA, S. KEVRESAN and J. KANDRAC
V.
Popsavin
Department of Chemistry,
Faculty of Science,
Full Article - PDF 118 KB
Copyright
&AMp; copy; SHD 2008.
For more information contact: JSCS@tmf.bg.ac.yu