J. Serb. Chem. Soc. 62(5) 389-392 (1997)
Original scientific paper
The synthesis and biological activity of 6-dichloromethyl-6-methyl-10-oxa-2-aza-bicyclo[5.3.0]dec-4-ene-3,9-dione, lactamic g-lactone
SLOBODAN SUKDOLAK, SLAVICA SOLUJIC and GORDANA STOJANOVIC*
Department of Chemistry, Faculty of Science, University of
Kragujevac, P.O.Box 60, YU-34000 Kragujevac and
*Department of Chemistry, Faculty of Philosophy, University of Nis, Cirila i Metodija 2, YU-18000 Nis, Yugoslavia
20 September 1996, revised 31 January 1997)
Lactamic y-lactone, 4 has been synthesized by a Beckmann rearrangement of a mixture of the corresponding (E)- and (Z)-oximes, 2 and 3, derived from trans-3H,3a,7aH-4-dichloromethyl-4-methyl- benzofuran-2,7-dione. The antibacterial and antifungal activities of the title compound have also been investigated.
Key words: g-lacone, beckmann rearrangement, biological activity, synthesis, oximes
Conversion of d-glucose to methyl a-d-altropyranoside derivatives
EVGENIJA CURENDIC, SMILJANA VELIMIROVIC, MIRJANA POPSAVIN, VELIMIR POPSAVIN and DUSAN MILJKOVIC
Institute of Chemistry, Faculty of Science, University of Novi Sad, Trg Dositeja Obradovica 3, YU 21 000 Novi Sad, Yugoslavia
11 October 1996, revised 8 February 1997)
A novel synthesis of methyl a-d-altropyranoside derivatives 5 and 6 has been achieved starting from methyl a-d-glucopyranoside (1). The action of tosyl chloride in pyridine on compound 1 afforded the 2,6-di-O-tosyl derivative 2 which was further treated with sodium acetate in N.N-dimethylformamide to give the 6-D-acetyl derivate 3. Treatment of 3 with aqueuos potasiium hydroxide give the methyl a-D-altropyranoside (5) which was subsequently acetylated to afford the corresponding peracetylated derivative 6.
Key words: d-altrose, a-d-glucopyranoside, partial tosylation, solvolysis
A mixed-valence complex of iron with 1,10-phenanthroline and the malonate ion
DJORDJE STOJAKOVIC and MAJA FERTILIO-TOMASEVIC
Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, P.O.Box 494, YU-11001 Belgrade, Yugoslavia
23 October 1997)
The synthesis of a mixed-valence complex in the ternary system Fe-phen-mal [phen=1,10-phenanthroline, mal=malonate(2-)ion] is reported. Based on elemental analysis. UV-vis spectroscopy. IR spectroscopy and magnetic susceptibility measurements, the formula [FeII(phen)3]2 [phen)2FeII(mal)2FeIII(OH)(H2O)(mal)2FeII(phen)2](mal)-46H2O is proposed for the compound. All the Fe(II) sites are diamagnetic (t2g6 configuration), while the Fe(III) site is paramagnetic (t2g3eg2). TG analysis shows that two thirds of the water content leave the system by 105°C, the remaining one third by 209°C, and the malonate ions are lost by 277°C.
Key words: iron complexes, mixed-valence compounds, polynuclear complexes, 1,10-phenanthroline, malonic acid
Mixed cobalt(III) complexes with 1,4,8,11-tetraazacyclotetradecane (cyclam) and a,w-dicarboxylato ligands
ZORAN MIODRAGOVIC, GORDANA VUCKVOIC, PETAR RADIVOJSA and VUKADIN LEOVAC*
Faculty of Chemistry, University of Belgrade, Akademski trg, P.O.Box 158, YU-11001
*Institute of Chemistry, Faculty of Science, University of Novi Sad, Trg Dositeja Obradovica 3, YU 21 000 Novi Sad, Yugoslavia
20 September, revised 14 November 1996)
By direct reaction, four mixed mononuclear cobalt(III) complexes with 1,4,8,11-tetraazacyclotetradecane (cyclam) and dicarboxylato ligands (dic: malonato, succinato, glutarato, and adipato ions), of the general formula [Co(dic)(cyclam)]ClO4 were obtained. It has been postulated that the geometry of all complexes is a deformed octahedron with the cyclam in a folded configuration and the bidentate dicarboxylate in the cis position bound through the two oxygen atoms of both carboxylic groups. For the glutarato-and adipato-complexes the supposed structure is an eight- and nine-membered chelate ring, respectively. the complexes were characterized by elemental analysis, ion-exchange chromartography, as well as electronic and IR spectroscopy.
Key words: cobalt(III) complexes, cyclam, a,w-dicarboxylato ligands
Homologation: the pathway of olefine conversion over pentasil zeolites
BORIVOJ ADNACEVIC and LAV AGABALYAN*
Faculty of Physical Chemistry, University of Belgrade,
Studentski trg 12-16, P.O.Box 137, YU-11001 Belgrade, and
Institute of General and Physical Chemistry, Studentski trg 12-16,
P.O.Box 551, YU-11001 Belgrade and
*CETA, Serpukhovskoy val 24, ? Moscow, Russia
9 September 1994, revised 21 December 1996)
Catalytic conversion of low concentration of gaseous mixtures of various alkenes in He over NiS modified zeolite of pentasil type was studied. Based on the established changes in the distribution of the products of catalytic conversion of alkene with a change in the reaction temperature and the concentration of alkene, benzene and CH3I in gas mixture, the model of the mechanism of catalytic conversion of alkene on zeolite catalyst was proposed. According to the model, the catalytic conversion, depending on reaction conditions, develops in three stages. In the first stage the transformation alkene fragments (cracks) and forms the so-called C1-intermediate particles. The formed C1-intermediate particles interact with the alkenes present in the reaction system by homologation reactions (the second stage of the transformation) which results in the growth of the carbon chain of the initial alkene. At high concentrations of the initial alkene, newly formed alkenes of relatively high molecular mass undergo disproportionation (the third stage of the transformation). The presumed model completely explains the changes appearing in the distribution of the products of catalytic conversion of alkene on the studies zeolite, under the influence of the changes in the reaction temperature and the concentration of alkene CH3I, and benzene in the gaseous mixture.
Key words: homologation, catalytic conversion, olefine, zeolite disproportionation
Diffusion of dimenhydrinate through artificial lipid membranes
NEBOJSA CVETKOVIC, DRAGICA POPADIC, ALEKSANDRA PEJCIC and MIROSLAVA NESIC
ICN Galenika - Institute, 29. Novembra 111, YU-11000 Belgrade, Yugoslavia
30 September 1996, revised 17 January 1997)
The solubility of dimenhydrnate was determined in solutions which simulated biological media, such as artificial gastric and intestinal juices. Starting from these media, diffusion was monitored through artificial lipid, artificial gastric and artificial intestinal membranes. It was found that the solubility of dimenhydrinate was higher in artificial gastric than in artificial intestinal juice and that the diffusion rate through an artificial intestinal membrane was in the initial period higher than that through an artificial gastric membrane.
Key words: dimenhydrinate, solubility, diffusion, partition, coefficient, artificial gastric juice, artificial gastric membrane, artificial intestinal juice, artificial intestinal membrane
Investigation of hydroxytriphenylmethane: Erichrome cyanine R reduction at a mercury electrode
DESANKA SUZNJEVIC, STEVAN BLAGOJEVIC, MILENKO ERCEG* and DRAGICA DUMANOVIC**
Institute of General and Physical Chemistry, Studentski trg 12-16,
P.O.Box 551, YU-11000 Belgrade and
*Forensic Institute, Kraljice Ane bb, YU-11000 Belgrade and
**ICN Galenika - Institute, 29. Novembra 111, YU-11000 Belgrade, Yugoslavia
20 September, revised 2 December 1996)
Eriochrome cyanine R (ECR) reduction at dropping mercury electrode, DME, produced two main waves A and B in direct current (dc) and differential pulse (dp) polarography from aqueous solution of pH 1.6 to 14. Only one wave was observed at higher acidity (Ho-3.63). The half-wave potential, or peak symmetry potential, of the waves A and B, from acetate buffer pH 4.8, were -0.45 V and -1.0 V, respectively. These waves belong to the same redox process. The wave at -0.45 V is predominantly diffusion controlled, while the wave at -1.00 V is adsorptive in nature. by applying cyclic voltammetry (cv) using a mercury pool electrode, only one pair of peaks was noticed belonging to a reversible two-electron diffusion controlled redox process of the quinone moiety reduction with the consumption of two protons. This pair corresponds to the polarographic wave observed at -0.45 V (wave A). The second wave was absent from the cv curves most probably due to the presence of a great capacitive current at the potential of the appearance of wave B.
Key words: eriochrome cyanine R, mercury electrode, polarography, cyclic voltammetry, reduction scheme
The effect of deposition process exchange current density on the thin metal film formation on inert substrate
K. I. POPOV, B. N. GRGUR, E. R. STOJILJKOVIC*, M. G. PAVLOVIC** and N. D. NIKOLIC**
Faculty of Technology and Metallurgy, Karnegijeva 4, P.O.Box
494, YU-11001 Belgrade,
*Faculty of Agriculture, YU-11080 Zemun, Belgrade and
**ICTM - Institute of Electrochemistry, Njegoseva 12, P.O.Box 815,
YU-11001 Belgrade, Yugoslavia
27 June 1996, revised 14 February 1997)
The initial stage of thin surface metal film formation on inert substrate is considered. The simultaneous action of both active centers and nucleation exclusion zones was taken into consideration when discussing the saturation nucleation exclusion zones was taken into consideration when discussing the saturation nucleus density. The saturation nucleus density increases with increasing number of active centers and decreasing the radii of nucleation exclusion zones (enhancing the thin metal film formation). Atone at the same deposition current density deposition overpotential increases with decreasing deposition process exchange current density, leading to the increase in the number of active centers and to decrease of crystallization overpotential and radii of nucleation exclusion zones. Because of this compact surface metal film will be formed at a lower quantity of electrodeposited metal with a decrease in exchange current density.
Key words: metal electrodeposition, surface metal film formation, thin metal film formation
Island growth of Au on Au(110)
SVETLANA STRBAC and ZLATKO RAKOCEVIC*
ICTM - Institute of Electrochemistry, Njegoseva 12, P.O.Box 815,
YU-11001 Belgrade and
*Vinca Institute of Nuclear Science, P.O.Box 522, YU-11001 Belgrade, Yugoslavia
16 December 1996)
The growth of Au on Au(110) single crystal substrates has been observed by scanning tunneling microscopy (STM) in air with a surface coverage by deposited gold atoms of up to 6 of a monolayer (ML). The Au grows in the island growth mode on the Au(110) surface. The islands are elongated along the  direction where the preferential diffusion of incoming adatoms occurs. The coalescence of islands by bridging via kinks along the  direction is the kinetic pathway to the growth of a 3D phase.
Key words: gold, island growth, Au(110), scanning tunneling microscopy