JSCS Vol 69, No. 5
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Impresum |
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J.Serb.Chem.Soc.
69(5)319–326(2004) |
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Synthesis of some 3-(thiazol-4-yl)-4-hydroxycoumarins
SLOBODAN SUKDOLAK, SLAVICA SOLUJIC, NENAD VUKOVIC,
NEDELJKO MANOJLOVIC and LJUBOMIR KRSTIC*
Faculty of Science,
University of Kragujevac, P. O. Box 60, 34000 Kragujevac and
*ICTM, Center of Chemistry, P. O. Box 815, 11001 Belgrade, Serbia and
Montenegro
(Received 20 September,
revised 16 December 2003)
In this work, an easy and efficient procedure
for the synthesis of eight 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives
is presented. 3-Acetyl-4-hydroxychromen-2-one (1) was brominated with
phenyltrimethylAMmonium tribromide to afford
3-(2-bromoacetyl)-4-hydroxychromen-2-one (2). Compound 2 reacts
with thiourea, thioacetAMide and AMmonium dithiocarbAMate to afford
3-(2-AMinothiazol-4-yl)-4-hydroxychromen-2-one (3),
4-hydroxy-3-(2-methylthiazol-4-yl)chromen-2-one (4a) and 4-hydroxy-3-(2-mercaptothiazol-4-yl)chromen-2-one
(5), respectively. In a similar manner, compound 2 was treated
with four mono-N-substituted thioureas and thiobenzAMide to give the
corresponding 3-(thiazol-4-yl)-4-hydroxychromen-2-one derivatives.
Keywords: Hantzsch reaction, 3-(2-bromoacetyl)-4-hydroxychromen-2-one,
3-(thiazol-4-yl)-4-hydroxycoumarins.
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J.Serb.Chem.Soc.
69(5)327–333(2004) |
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Synthesis and characterization of chromogenic fluoran compounds containing
4-ketoquinazolinone moieties
RITESH G. PATEL, MANISH P. PATEL and RANJAN G.
PATEL
Department of Chemistry,
Sardar Patel University, Vallabh Vidyanagar-388 120, Gujarat, India
(Received 18 August,
revised 5 December 2003)
Chromogenic fluoran compounds containing
4-ketoquinazolinone were synthesized by reacting
2-(4-diethylAMino-2-hydroxybenzoyl)benzoic acid with various substituted
4-ketoquinazolinones in the presence of sulfuric acid. The 4-ketoquinazolinones
were obtained by reacting various substituted benzoxazin-4-ones with
4-AMinophenol or 2-nitro-p-anisidine. All the synthesized derivatives
were identified by conventional methods, such as melting points, elemental
analysis, IR, 1H-NMR, and UV-visible spectroscopy in organic solvent
and 95 % acetic acid. All the fluoran compounds develop colour on contact with
acidic or electron-accepting compounds.
Keywords: synthesis, fluoran compounds, 4-ketoquinazolinone, colour change.
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J.Serb.Chem.Soc.
69(5)335–341(2004) |
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Synthesis, as well as linear and nonlinear fluorescence properties of
5,5’-bis(4-N-carbazolylstyryl)-2,2’-bithiophene
GUANG-MING XIA, PINGLUa and GUI-BAO XU*
School of Chemistry and Chemical Engineering, Ji’nan University, Ji’nan 250022,
P. R. China and
*State Key Laboratory of Crystal Materials, Shandong University, Ji’nan 250100,
P. R. China
(Received 28 July,
revised 16 December 2003)
A new bithiophene-based
organic luminescence material, nAMed 5,5’-bis(4-N-carbazoylstyryl)-2,2’-bithiophene
(BCSBT), was synthesized. Its single-photon excited fluorescence band is located
in the range of 520–530 nm, with a quantum yield of around 10 %. The compound
emits strong two-photon-excited fluorescence when excited by 200 fs laser
pulses. The two-photon absorption cross section of BCSBT was found to be 124×10–50
cm4 s by the two-photon-excited fluorescence method.
Keywords: two-photon absorption, up-converted fluorescence, bithiophene
derivatives.
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J.Serb.Chem.Soc.
69(5)343–348(2004) |
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Covalent glycoinositolphospholipid (GPI) binding
to hemoglobin is associated with insulin-activation
of erythrocyte membrane protease
DRAGANA STANIC, MILAN NIKOLIC* and VESNA
NIKETI]C*
ICTM – Center for
Chemistry, Njegoseva 12, 11001 Belgrade and
*Department of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box
158, 11001 Belgrade, Serbia and Montenegro
(Received
17 September 2003)
Recently, it was demonstrated that prolonged hyperinsulinism associated with
hypoglycemia, both in vivo and in vitro, caused covalent
glycoinositolphospholipid (GPI) binding to the C termini of both hemoglobin b-chains, which resulted in the formation of a novel, hitherto
unrecognized, minor hemoglobin fraction (GPI-Hb) (Niketic et al.,
Biochem. Biophys. Res. Commun. 239 (1997) 435). In this study it was
demonstrated that exposure of erythrocyte membranes to insulin causes the
activation of membrane protease as well as that the formation of GPI-Hb
parallels its activity. It is suggested that the insulin-activated protease is
able to catalyze, albeit slowly, the transpeptidation, i.e., the
replacement of the carboxy-terminal AMino acid(s) residues of the Hb b-chains with GPI as an exogenous nucleophile. To our knowledge the
present results show for the first time that insulin stimulates protease
activity in erythrocyte membranes, as well as that insulin-activated protease
may be involved in post-translational GPI binding to proteins.
Keywords: insulin, hemoglobin, glycoinositolphospholipid, erythrocytes,
protease.
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J.Serb.Chem.Soc.
69(5)349–351(2004) |
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N O T E
Synthesis of 3a,12a-dihydroxy-23a,23b-dihomo-5b-cholan-24-oic acid
VERA CIRIN-NOVTA, KSENIJA KUHAJDA, JULIJAN
KANDRAC* and SLAVKO KEVRESAN*
Department of Chemistry,
Faculty of Science, Trg Dositeja Obradovica 3, 21000 Novi Sad and
*Faculty of Agriculture, Trg Dositeja Obradovica 3, 21000 Novi Sad, Serbia and
Montenegro
(Received 8 September,
revised 1 December 2003)
A novel multi-step synthesis of 3a,12a-dihydroxy-23a,23b-dihomo-5b-cholan-24-oic acid (23a,23b-dihomodeoxycholic acid) (5)
has been achieved from methyl 3a,12a-dihydroxy-5b-cholanoate (1).
Reduction of compound 1 with LiAlH4 in dry ether gave the
corresponding alcohol 2 in 83 % yield. Selective esterification of compound 2
with tosyl chloride in dry piridine at 0–5 ºC for 12 h afforded the 3a,12a-dihydroxy-5b-24-cholanyl tosylate (3) in 64 % yield. The reaction of
the tosyl derivative
3 with sodium diethyl malonate gave compound 4
which was first subjected to hydrolysis under basic conditions, followed by
decarboxylation under acidic conditions to afford 3a,12a-dihydroxy-5b-23a,23b-dihomocholan-24-oic acid in 84 % yield.
Keywords: 26-homodeoxycholic aicd, bile acids.
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J.Serb.Chem.Soc.
69(5)353–362(2004) |
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Crystal structure of a new zigzag chain Cu(II)
complex with terephthalato and
1,10-phenanthroline ligands, [Cu(C8H4O4)(C12H4N2)(H2O)]n
JELENA ROGAN, DEJAN POLETI and LJILJANA
KARANOVIC*
Faculty of Technology
and Metallurgy, Karnegijeva 4, 11000 Belgrade and
*Faculty of Mining and Geology, Djusina 7, 11000 Belgrade, Serbia and
Montenegro
(Received 8 September,
revised 17 December 2003)
X-Ray crystal structure analysis of the complex
[Cu(tpth)(phen)(H2O)]n, where tpht is the dianion of
terephthalic acid and phen is 1,10-phenanthroline, showed that two
crystallographically different, but chemically identical tpht ions with
monodentately coordinated COO groups exist; both tpht ions act as bridging
ligands forming zigzag chains. The Cu(II) ions are in a deformed trigonal
bipyrAMidal environment consisting of two N atoms from phen, two O atoms from
different tpht ligands and one O atom from coordinated H2O molecule.
The crystal data are as follows: C20H14CuN2O5,
Mr = 425.87, triclinic system, space group P 1, a = 9.007(5),
b = 10.557(5), c = 11.554(5) Å, a = 114.343(5), b = 92.942(5), g = 114.516(5) º, V =
877.3(7) Å3, Z = 2, F(000) = 434, rx = 1.612 g cm-3, m = 1.281 mm-1, R1 = 0.0280 for 4363
reflections with I > 2s(I), wR2
= 0.0785 for 5104 independent reflections and 254 refined parAMeters. Some of
data were compared with isostructural Co(II) and Zn(II) complexes having the
sAMe ligands.
Keywords: transition metal complexes, copper(II), terephthalate ions,
1,10-phenanthroline, crystal structure.
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J.Serb.Chem.Soc.
69(5)363–375(2004) |
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An investigation of the functional groups on the surface of activated carbons
JURGIS BARKAUSKAS and MARYTE DERVINYTE
Department of General
and Inorganic Chemistry, Vilnius University, Naugarduko 24, 2006 Vilnius,
Lithuania
(Received 24 April,
revised 16 December 2003)
Abstract: Activated carbons were produced in the
laboratory from wood using a 20-run Plackett–Burman experimental design for 19
factors. The obtained batches of activated carbon were analysed by
potentiometric titration and FTIR spectroscopy to determine the surface
functional groups. The results obtained by potentiometric titration displayed
the distribution of individual acidity constants of those groups in the pK
range. Considering this parAMeter, the surface functional groups were divided
into carboxyl, lactone and phenol. The linear regression equations reflecting
the influence of each operation used for the synthesis on the AMount of these
functional groups in the obtained activated carbons were generated. The FTIR spectra
were used in parallel for the evaluation of the AMount and the type of the
surface functional groups. Relationships between the two data sets obtained by
potentiometric titration and FTIR spectroscopy were evaluated by correlation
analysis. It was established that the AMount of surface functional groups
determined by potentiometric titration positively correlates with the intensity
of the peaks of hydrophilic functional groups in the FTIR spectra. At the sAMe
time, the negative correlation between potentiometrically determined AMount of
surface functional groups and the intensity of peaks of hydrophobic functional
groups was observed. Most probably, these non-polar formations can take part in
the interaction of carbon surface with H+/OH- ions and
diminish the strength of existent functional groups.
Keywords: activated carbon, functional groups, adsorption, correlation,
acid-base equilibrium.
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J.Serb.Chem.Soc.
69(5)377–385(2004) |
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The influence of ethanol addition on the spatial emission distribution of
traces
in a vertical argon stabilized DC arc plasma
SLAVICA RAZIC, IVANKA HOLCLAJTNER-ANTUNOVIC* and
MARIJA TODOROVIC**
Faculty of Pharmacy,
University of Belgrade, P. O. Box 146,
*Faculty of Physical Chemistry, University of Belgrade, P. O. Box. 137 and
**Faculty of Chemistry, University of Belgrade, P. O. Box 158, 11000 Belgrade,
Serbia and Montenegro
(Received 16 May,
revised 16 December 2003)
The plasma of a vertical argon stabilized DC arc
at atmospheric pressure is applied as a spectrochemical source. The lateral
distributions of relative spectral line intensities of some trace elements (Zn,
Pt, Cd, Mg, Ca and Al) introduced into the plasma in the form of aqueous and ethanol–aqueous
solutions were experimentally determined. These distributions were correlated
with the calculated equilibrium plasma composition of the arc plasma. On the
basis of the obtained results, an explanation of the influence of ethanol
addition on the radiation densities from an arc plasma is given.
Keywords: vertical argon stabilized DC arc plasma, ethanol addition, spatial
emission distribution.
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J.Serb.Chem.Soc.
69(5)387–392(2004) |
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Spectroscopic study of the Eu(fod)3 complex
adsorbed on a 3-trimethoxypropylthioethylAMine modified silica surface
ROBSON F. DE FARIAS, SEVERINO ALVES JR.*, MONICA
F. BELIAN*, MAGDAR. S. VIEIRA*,
JUCIMAR M. DE SOUZA*, GILMARA G. PEDROSA* and GILBERTO F. DE SÁ*
DepartAMento de Quimica, Universidade Federal de Roraima, 69310-270, Boa Vista,
Roraima, Brasil and
*DepartAMento de Quimica FundAMental, Universidade Federal de PernAMbuco,
50670-901 Recife, PernAMbuco, Brasil
(Received 24 September
2003)
By using 3-mercaptopropyltrimethoxysilane and
ethylenediAMine as precursors, the compound 3-trimethoxypropylhioethylAMine was
synthesized, and then used as a silylating agent to obrtain, through a sol-gel
process, an organicmodification of a silica-gel sAMple. Asurface thus modified
was used as a substrate for the adsorption of the luminescent Eu(fod)3·2H2O
complex. Eu(fod)3·2H2O and the silicon hybrid were mixed
in stoichiometric AMounts to produce sAMples with 1 %, 5 % and 10 % (m/m) of
adsorbed complex. The adsorbed complex was then studied from the spectroscopic
point of view. The lifetimes measured for the emission process are 476, 542 and
566 ms for 1 %, 5 % and 10 % sAMples, respectively.
Furthermore, comparison with experimental data for n-[3(trimethoxysilyl)
propyl]-ethylenediAMine modified silica gel surfaces emphasizes the prominenet
role of the chemical composition of the silica modified surface on the
spectroscopic properties of the adsorbed complex.
Keywords: europium(III) complex, sol-gel, luminescence, hybrids.
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J.Serb.Chem.Soc.
69(5)393–402(2004) |
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Determination of iron in natural and mineral waters by flAMe atomic absorption
spectrometry
STASYS TAUTKUS, LAURASTEPONENIENE and ROLANDAS
KAZLAUSKAS
Deparment of Analytical
and Environmental Chemistry, Vilnius University, Naugarduko 24, LT-2006
Vilnius, Lithuania
(Received 2 June,
revised 16 December 2003)
Simple methods for the determination of Fe in
natural and mineral waters by flAMe atomic absorption spectrometry (AAS) are
suggested. The results of the investigation of selectivity of the proposed AAS
method proved that this procedure is not affected by high concentrations of
other metals. The calibration graph for iron was linear at levels near the detection
limit up to at least 0.10 mg ml-1. For
the determination of microAMounts of iron in mineral waters, an extraction AAS
technique was developed. Iron was retained as Fe-8-oxyquinoline complex and
extracted into chloroform. The optimal conditions for the extraction of the
iron complex were determined. The AAS method was applied to the determination
of Fe in mineral waters and natural waters from different areas of Lithuania.
The accuracy of the developed method was sufficient and evaluated in comparison
with a photometric method. The obtained results demonstrated that the procedure
could be successfully applied for the analysis of water sAMples with
satisfactory accuracy.
Keywords: iron determination, flAMe atomic absorption spectrometry,
preconcentration, water analysis.
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J.Serb.Chem.Soc.
69(5)403–410(2004) |
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Quantitative determination of pefloxacin
mesylate by residual-base neutralisation method
KANAKAPURA BASAVAIAH and HULIKALCHANDRA SHEKAR
PRAMEELA
Department of Chemistry,
University of Mysore,Manasagangotri,Mysore - 570 006, India
(Received 13 August,
revised 5 December 2003)
This work describes two procedures based on
residual base determination for the quantification of pefloxacin mesylate (PFM)
in bulk drug and in pharmaceutical products. In the first method involving
titrimetry, the drug solution is treated with a measured excess of sodium
hydroxide followed by back titration of the residual base with hydrochloric
acid using a phenol red-bromothymol blue mixed indicator. The second
spectrophotometrie method involves treatment of a fixed AMount of sodium
hydroxide – phenol red mixture with varying AMounts of the drug, and measuring
the decrease in the absorbance of the dye at 560 nm. In the titrimetric method,
a reaction stoichiometry of 1:1 was found in the quantification range of 4–20
mg of drug. The spectrophotometric method allows the determination of PFM in
the 5–40 mg ml-1 range. The molar absorptivity
is 5.91¤103 l mol-1 cm-1 and the Sandell
sensitivity is 56.37 ng cm-2. The methods were applied successfully
to the determination of PFM in pharmaceutical preparations.
Keywords: pefloxacin, determination, titrimetry, spectrophotometry, pharmaceuticals.
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BOOK REVIEW
FUNDAMENTAL ASPECTS OF
ELECTROMETALLURGY
by Konstantin I. Popov, Stojan S. Djokic and
BrAMmir Grgur
Published by Kluwer
Academic/ Plenum Publishers, New York, 2002, ISBN 0-306-47269-4
This book is published
on 305 pages with 152 figures, 414 equations, 14 tables and 299 references. It
is divided in 12 chapters: 1. What is Electrometallurgy; 2. Definitions,
Principles and Concepts; 3. Surface Morphology of Metal Electrodeposits; 4. The
Current Distribution in Electrochemical Cells; 5. Electrodeposition at
Periodically Changing Rate; 6. Electrowinning; 7. Electrorefining; 8. Optimum
Conditions for Electroplating; 9. Electroplating and Surface Finishing; 10.
Metal Deposition without an External Current; 11. Electrodeposition of Metals
from Molten Salts; 12. Environmental Issues.
In order to give some comments about the scientific value of this book, in
spite of my experience in metal deposition. I decided to cite some parts of the
foreword for this book which was written by the one of the leaders in world’s
electrochemistry, Professor John O’M. Bockris from Texas A&AMp;M
University. In his foreword, AMong other comments, he said:
"The numerous technologies vary greatly in the degree to which they are
intellectualized. Until the work of Popov et al., electrometallurgy has been
regarded as largely empirical, an activity in which there was much art and
little science. This will all change with the publication of this book.
There are many figures in this splendid book of Popov et al. which impress me.
The first is the strong, broad contents of its arrangement. There is a fine
first chapter on principles of application to electrochemical kinetics – the
equations being written in a form modified for use in electrometallurgical
situations (e.g., deposition on the tips of growing crystals of minimal radius
of curvature and on corners and edges). Here, it is encouraging to find authors
applying the electrochemical version of Kelvin’s equation relating vapor
pressure as a function of the radius of drops to the phenomena during the
electrogrowth of dendrites.
I personally find the treatments of the effects of current varying regimes
(e.g., pulse, reverse pulse, square wave, sinusoidal, etc.) the most exciting
for I have long thought that instead of the use of chemical additives to the
solution, the type of surface finally produced – even the crystal shape – could
be achieved by electrical variations only. This book contains much toward the
realization of this approach.
In the second half of the book, one finds themathematical treatments of
practical situations in electrowinning, electrorefining, electroplating and
electroforming. What is the difference all this will make? It should enable to
engineer to set up regimes to achieve what he wants with a minimum of prefatory
experiments.
This book has no competitor. There are certainly books on electroplating. but
they are largely recipes for what to do which eschew the important question of
why.
Getting the intellectual side over to the
practical engineer, of course, requires great lucidity, for he will not puzzle
over material delivered over his head. I think the required clarity has been
attained herewith, particularly in the early chapters where the concepts of
exchange currents and overpotential are being added to the weary thermodynAMics
which covers most of what engineers are likely to know about electrochemistry.
A great strength is in the photographs of electrodeposited
crystals in all their variety. Such photographs can be found in the usual
journals, but I have not previously
seen such a collection accompanied by textual
rationalization.
Lastly, I was impressed by the application of
the theory to areas which normally receive little more than a definition. I
would cite electropolishing, where theory is seldom presented;
electromashining; and electroless plating."
Finally, it should be emphasized here that
almost 70%of the results presented in this book has been published in the
Journal of the Serbian Chemical Society, making this Journal one of the most
known in the field of electrometallurgy.
Prof. Vladimir Jovic
Center for Multidisciplinary Studies
University of Belgrade
Copyright &AMp; copy; SHD 2004.
June 9, 2004.
For
more information contact: SHD@tmf.bg.ac.yu