JSCS Vol 69, No. 8-9
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Impresum |
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J.Serb.Chem.Soc.
69 (8–9) 601–610 (2004) |
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The influence of the
solvent on organic reactivity. Part II. Hydroxylic solvent effects on the
reaction rates of diazodiphenylmethane with 2-(2-substituted
cyclohex-1-enyl)acetic and 2-(2-substituted phenyl)acetic acids
JASMINA B. NIKOLIC, GORDANA S. USCUMLIC and VERA
V. KRSTIC
Department of Organic Chemistry, Faculty of Technology and Metallurgy, University
of Belgrade,
Karnegijeva 4, P. O. Box. 494, 11000 Belgrade, Serbia and Montenegro
(Received 5 December
2003, revised 20 February 2004)
The rate constants for the reaction of
diazodiphenylmethane with 2-(2-substituted cyclohex-1-enyl)acetic acids and
2-(2-substituted phenyl)acetic acids, previously determined in seven hydroxylic
solvents, were correlated using the total solvatochromic equation, of the form:
log k = log k0 + sp* + aa + bb, the two-parAMeter model, log log k = log k0
+ sp* + aa, and a single parAMeter
model k = log k0 + sp* + bb, where p* is a measure of the solvent polarity, b represents the scale of solvent hydrogen bond acceptor basicities
and a represents the scale of solvent hydrogen bond
donor acidities. The correlations of the kinetic data were carried out by means
of multiple linear regression analysis and the solvent effects on the reaction
rates were analysed in terms of initial state and transition state
contributions.
Keywords: 2-(2-substitued cyclohex-1-enyl)acetic acids, 2-(2-substituted
phenyl)acetic acids, diazodiphenylmethane, kinetic measurements, protic
solvents.
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J.Serb.Chem.Soc.
69 (8–9) 611–624 (2004) |
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Interpretation of Serbian surface sediments’ maturation parAMeters based on
factor analysis
A.SAINOVIC*, K. STOJANOVIC**, I. FILIPOVIC***,
O. CVETKOVIC***, B. JOVANCICEVIC*,*** and D. VITOROVIC***
*Department of Chemistry, University of Belgrade,
P. O. Box 158, 11001 Belgrade,
**Department of Medicine, University of Belgrade, Visegradska 26, 11000
Belgrade and
***Center of Chemistry, ICTM, Njegoseva 12, 11000 Belgrade, Serbia and
Montenegro
(Received 30 December
2003)
The factor analysis,
used in this work for the interpretation of maturation parAMeters observed in
an exploration study of a group of surface sediments of diverse age originating
from different localities in Serbia, resulted in two significant factors.
Factor 1 involved parAMeters related mainly to maturation changes within the
aliphatic chains of the organic matter and factor 2 involved parAMeters based
mainly on changes in the terpane and sterane rings. A statistically significant
inversely proportional linear dependence between factors 1 and 2 was observed
with older, in contrast to younger sediments, suggesting that the reactions of
the aliphatic chains in the older sediments did not occur simultaneously with
the reactions in the rings and, also, that the older surface sediments exAMined
in this study may be characterized by a degree of thermal maturity
corresponding to changes in the biomarker sterane and terpane rings, while the
younger sediments by intensive changes in the aliphatic chains.
Keywords: factor analysis, maturation parAMeters, biological markers,
surface sediments.
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J. Serb. Chem.
Soc. 69 (8–9) 625–634 (2004) |
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The exAMination of parAMeters for lactic acid
fermentation and nutritive value of fermented juice of beetroot, carrot and
brewer’s yeast autolysate
MARICA RAKIN, JOSIP BARAS, MAJA VUKASINOVIC* and MILAN MAKSIMOVIC*
Faculty of Technology
and Metallurgy, Karnegijeva 4, Belgrade and
*Military Medical Academy, Institute of Hygiene, Crnotravska 17, Belgrade,
Serbia and Montenegro
(Received 22 October
2003, revised 22 April 2004)
The conditions for
lactic acid fermentation based on a mixture of beetoot juice (Beta vulgaris
L.) and carrot juice (Daucus carota L.) and different content of
brewer’s yeast autolysate with Lactobacillus plantarum A112 and with Lactobacillus
acidophilus NCDO 1748 has been studied. Both cultures showed good
biochemical activity in these mixtures. The production of lactic acid has been
stimulated using a higher content of brewer’s yeast autolysate. In these
mixtures, L. plantarum A112 showed better growth and lactic acid
production than L. acidophilus NCDO 1748. From the data obtained through
chemical analyses of the fermented products, it can be seen that the mixture of
beetroot and carrot juice and brewer’s yeast autolysate is richer in minerals
(Ca, P, Fe) and b-carotene than fermented
beetroot juice with the sAMe content of brewer’s yeast autolysate.
Keywords: beetroot, carrot, lactic acid fermentation, autolysate of brewer’s
yeast, nutrition.
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J. Serb. Chem.
Soc. 69 (8–9) 635–640 (2004) |
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SHORT COMMUNICATION
Variation in the chemical constituents of
soybean due to industrial pollution
DEVENDRA K. PATEL, RANJAN KUMAR* and SATGUR
PRASAD*
Department of Post
Graduate Studies and Research in Chemistry, Rani Durgavati University, Jabalpur
(M.P.) and
*Analytical Chemistry Section, Industrial Toxicology Research Centre, M.G.
Marg, P. O. Box–80, Lucknow, Pin-226001 (U.P.) India
(Received 19 November
2003, revised 28 April 2004)
The two varieties of
soybean (Soybean Bragg and Soybean JS-71-05) were collected from
an industrial site (IS) and from a non-industrial site (NIS) for the study of
their chemical composition and fatty acids profiles by gas liquid
chromatography (GLC). These studies revealed large changes in the major and
minor fatty acids of the soybean seeds due to the effect of chemical
pollutants. There was a significant decrease in the AMounts of major and minor
fatty acids, such as myristic acid (14:0), palmitic acid (16:0), stearic acid
(18:0), oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3), in
the seeds from industrial site. The changes in the chemical composition due to
chemical pollutants showed mixed results.
Keywords: pollutant, pollution, gas liquid chromatography, chemical
analysis, instrumental analysis, macromolecules, lipids, fatty acids, soybean,
industrial site, non-industrial site.
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J. Serb. Chem.
Soc. 69 (8–9) 641–6649 (2004) |
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Synthesis and characterization of Ni(II), Cu(II)
and Co(III) complexes with polyAMine-containing macrocycles bearing an
AMinoethyl pendant arm
FOUZIA RAFAT, M. Y. SIDDIQI* and K. S.
SIDDIQI
Department of Chemistry, Aligarh Muslim University, Aligarh 202002, India
*Research Center, College of Sciences, King Saud University, Riyadh 11451, KSA.
(Received 19 January
2004)
Reaction of [M(ppn)2]X2
(where M = Cu(II), Ni(II), Co(II) and ppn = 1,3-diAMinopropane) with
formaldehyde and ethylenediAMine in methanol results in the ready formation of
a 16-membered macrocyclic complex. The complexes were characterized by
elemental anlysis, IR, EPR, electronic spectral data, magnetic moments and
conductance measurements. The Cu(II), Ni(II) and Co(III) complexes are
coordinated axially with both pendant groups of the hexadentate macrocycle.
These pendant donors are attached to the macrocycle by a carbon chain. The
electrical conductivities of the Cu(II) and Ni(II) chelates indicated them to
be 1:2 electrolytes whilst those of Co(III) is a 1:3 electrolyte in DMSO. The
EPR spectrum of the copper complex exhibited G at 3.66, which indicates
a considerable exchange interaction in the complex. Spectroscopic evidence
suggests that in all of the complexes the metal ion is in an octahedral
environment.
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J. Serb. Chem.
Soc. 69 (8–9) 651–660 (2004) |
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Synthesis and characterization of zinc(II),
palladium(II) and platinum(II) complex with
2’-[1-(2-pyridinyl)ethylidene]oxAMohydrazide. The crystal structure of
bis{2’-[1-(2-pyridinyl)ethylidene]oxAMohydrazido}zinc(II) trihydrate
KATARINA AN\ELKOVIC, GORDANA JAKOVLJEVIC, MARIO
ZLATOVIC, ZIVOSLAV TESIC, DUSAN SLADIC, JONAS HOWING* and ROLAND TELLGREN*
aculty of Chemistry, University of Belgrade, Studentski trg 16, P. O. Box
158, 11001 Belgrade, Serbia and Montenegro and
*Department of Materials Chemistry, The Ångström Laboratory, Uppsala
Univeristy, Box 538, S-75121 Uppsala, Sweden
(Received 3 November
2003, revised 26 February 2004)
Complexes of Zn(II), Pd(II) and Pt(II) with
2’-[1-(2-pyridinyl)ethylidene]oxAMohydrazide (Hapsox) were synthesized and
their structures were determined. All the complexes are of a neutral type with
two apsox ligands coordinated to Zn(II) and one apsox ligand coordinated to
Pd(II) or Pt(II). In each case, the polydentate was coordinated via pyridine
and hydrazone nitrogens and a-oxyazine oxygen, forming
an octahedral geometry around Zn(II), and a square planar one around Pd(II) and
Pt(II). The structure determination was performed by IR, 1H-NMR and 13C-NMR
spectroscopy, and for the Zn(II) complex by X-ray structure analysis.
Keywords: Zn(II) complex, Pd(II) complex, Pt(II) complex, 2-acetylpyridine
derivative, X-ray analysis, NMR spectra.
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J. Serb. Chem.
Soc. 69 (8–9) 661–668 (2004) |
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Ca(II) complexes of tetraazAMacrocycles derived from 3,4-hexanedione and
diAMinoalkanes
R.N. PRASAD, MITHLESH AGRAWAL and SANGEETA
MALHOTRA
Department of Chemistry,
University of Rajasthan, Jaipur-302004, India
(Received 8 January
2004)
Ca(II) macrocyclic complexes [(Et4[n]tetraeneN4)CaX2]
(where n = 14, 16, 20, 24, 32, X = Cl-, NCS-) have been
synthesized via cyclocondensation of 3,4-hexanedione with aliphatic diAMines,
such as 1,3-diAMinopropane, 1,4-diAMinobutane, 1,6-diAMinohexane, 1,8-diAMinooctane
or 1,12-diAMinododecane. The synthesized complexes were characterized by
elemental analyses, conductance measurements and IR and 1H-NMR
spectroscopy.
Keywords: macrocyclic complexes, alkaline earth metal complexes, IR spectra,
NMR spectra.
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J. Serb. Chem.
Soc. 69 (8–9) 669–674 (2004) |
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Isobaric vapour–liquid equilibrium calculations of binary systems using a
neural network
MEHMET BILGIN
Istanbul University,
Engineering Faculty, Department of Chemical Engineering, 34320 Avcilar,
Istanbul, Turkey
(Received 13 November
2003, revised 3 March 2004)
A model on a feed forward back propagation
neural network was employed to calculate the isobaric vapour–liquid equilibrium
(VLE) data at 40, 66.67, and 101.32 ± 0.02 kPa for the methylcyclohexane –
toluene and isopropanol – methyl isobutyl ketone binary systems, which are
composed of different chemical structures (cyclic, aromatic, alcohol and
ketone) and do not show azeotrope behaviour. Half of the experimental VLE data
only were assigned into the designed frAMework as training patterns in order to
estimate the VLE data over the whole composition range at the mentioned
pressures. The results were compared with the data calculated by the two
classical models used in this field, the UNIFAC and Margules models. In all
cases the deviations the experimental activity coefficients and those
calculated by the neural network model (NNET) were lower than those obtained
using the Margules and UNIFAC models.
Keywords: vapour–liquid, neural network, activity coefficients, UNIFAC,
Margules model.
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J. Serb. Chem.
Soc. 69 (8–9) 675–681 (2004) |
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The effect of diluents on the extraction of Sm(III) using N,N,N’,N’-tetrabutylmalonAMide
SUN GUO-XIN, CUI YU, ZHANG ZHEN-WEI, XU RONG-QI,
JIANG RUN-TIAN AND SUN SI-XIU*
Institute of Chemistry
and Chemical Engineering, Jinan University, Jinan, 250022, P. R. China and
*College of Chemistry and Chemical Engineering, Shandong University, Jinan,
150100, P. R. China
(Received 6 June 2003,
revised 19 February 2004)
A study has been made of the extraction of
sAMarium(III) from nitrate solutions using N,N,N’,N’-tetrabutylmalonAMide
(TBMA) in a series of diluents. The dependence of the extraction distribution
on the concentrations of aqueous nitric acid, lithium nitrate and organic TBMA
was investigated. The experimental results showed that the extraction
efficiency of TMBA in different diluents for Sm(III) increases in the order:
chloroform, carbon tetrachloride, benzene, xylene, toluene, cyclohexane, n-hexane,
n-octane. The stoichiometry of the extracted species conform to Sm(NO3)3.3TBMA
in all the employed diluents. The interaction between extractant or extracted
species and diluent is discussed and a quantitative expression relating the
extraction constant and the parAMeters of the diluent has been established.
Keywords: extraction, sAMarium(III), N,N,N',N'-terabutylmalonAMide.
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J. Serb. Chem.
Soc. 69 (8–9) 683–688 (2004) |
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Separation of tungsten and rhenium on alumina
JURIJ L. VUCINA,, DRAGOLJUB M. LUKIC and MILOVAN
SM. STOILJKOVIC*
Laboratory for Radioisotopes and
*Department of Physical Chemistry, Vinca Institute of Nuclear Sciences, 11001
Belgrade, P. O. Box 522, Serbia and Montenegro
(Received 19 December
2003, revised 19 February 2004)
The conditions for the efficient separation of
tungsten(VI) and rhenium (VII) on alumina were established. The distribution
coefficients Kd for tungstate and perrhenate anions, as well as the
separation factors a (a = KdWO42-/Kd
ReO4-) were determined using hydrochloric or nitric acid
as the aqueous media. A solution of sodium chloride in the pH range 2–6 was
also exAMined. Under all the tested experimental conditions, alumina is a much
better adsorbent for tungsten than for rhenium. The obtained results indicated
that the best separation of these two elements is achieved when 0.01– 0.1 mol
dm-3 HCl or 1.0 mol dm-3 HNO3 are used as the
aqueous media. If NaCl is used as the aqueous phase, the best separation is
achieved with 0.20 mol dm-3 NaCl, pH 4–6. Under these experimental
conditions, the breakthrough and saturation capacities of alumina for tungsten
at pH 4 are 17 and 26 mg W/g Al2O3, respectively. With
increasing pH, these values decrease. Thus, at pH 6 they are only 4 and 13 mg
W/g Al2O3, respectively.
Keywords: tungsten, rhenium, separation
factor, distribution coefficient.
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J. Serb. Chem.
Soc. 69 (8–9) 689–703 (2004) |
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Electrochemical behavior of some new pyrimidine derivatives
HASAN KILIÇ and MUSTAFA LUTFU BERKEM
Marmara University,
Faculty of Sciences and Letters, Department of Chemistry 34722 Ziverbey,
Istanbul, Turkey
(Received 21 January
2004)
Electrochemical reduction of two recently
synthesized pyrimidine compounds,
1-AMino-5-benzoyil-4-phenyl-1H-pyrimidine-2-one (I), and
1-AMino-5-benzoil-4-phenyl-1H-pyrimidine-2-thione (II) were investigated
by cyclic volatmmetry at a hanging mercury drop electrode in aqueous methanol
(36 % v/v) and in non-aqueous methanol. A series of cathodic peaks without the
corresponding anodic peaks were observed for I. As the pH of the solution was
increased, some of the cathodic peaks overlapped resulting in the loss of the
previously observed peaks. For II, three cathodic peaks and one anodic
peak were observed in addition to those observed for I. The peak
potentials shifted in the negative direction with increasing pH. This shift was
measured over a large pH range (1.80 – 12.30) to determine the pKa
values of the compounds. The acidity constants related to the AMino groups were
4.80 and 9.80 for I and 5.50 and 9.80 for II. A thiol-thione
tautomerization was observed for II, which was more pronounced in the
non-aqueous methanol medium. The pK values for both protonation and
deprotonation of the thiocarbonyl group were also determined. The pK
values were 5.80 and 9.80 for protonation and deprotonation in aqueous methanol
and 6.80 and 10.80 in non-aqueous methanol.
Keywords: pyrimidine-one, pyrimidine-thione, pyrimidine bases, cyclic
volatmmetry, hanging mercury drop electrode.
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J. Serb. Chem.
Soc. 69 (8–9) 705–710 (2004) |
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Thermal conductivity of pressureless sintered Si3N4
cerAMics with Li-exchanged zeolite
BRANKO MATOVIC and SNEZANA BOSKOVIC
The Vinca Institute of Nuclear Sciences, Lab. 170, 11001 Belgrade, Serbia
and Montenegro
(Received 26 December
2003)
The effects of temperature on the thermal
conductivity of Si3N4 sintered with Li-exchanged zeolite
were investigated. The highest conductivity was measured for the cerAMics
sintered with 10 % of additive. The complete a->b-Si3N4
transformation and maximum density (> 98 % TD) were attained with the sAMple
sintered at 1650 ºC. However, the results show that Al and O from the additive
dissolve into the b-Si3N4
structure which act as phonon scattering sites resulting in a lowering of the
conductivity and a weaker temperature dependance of the conductivity.
Keywords: pressureless sintering, silicon nitride, thermal conductivity.
Copyright &AMp; copy; SHD 2004.
October 8, 2004.
For
more information contact: JSCS@tmf.bg.ac.yu