Abstracts

Vol. 18, No. 1, 1999

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 1–5 (1999)

GHTMDD – 319 ISSN 0350 – 0136

Received: December 28, 1998 UDC: 547.21 : 544.131

Accepted: April 2, 1999

It is shown that the Randi} connectivity index c of any alkane satisfies the relation , where and . Besides, holds in the case of normal alkanes, whereas in the case of alkanes possessing no CH and CH₂ groups.

Keywords: Randi} index; connectivity index; QSPR; QSAR

Klu~ni zborovi: Randi}ev indeks na povrzanost; indeks na povrzuvawe; QSPR; QSAR

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 7–14 (1999)

GHTMDD – 320 ISSN 0350 – 0136

Received: February 2, 1999 UDC: 542.952.53–927.5 : 543.422

Accepted: May 11, 1999

Katica ^olan~eska-Rag`enovi}¹, Mirjana Eckert-Maksi}² and @eljko Marini}²

The mode of protonation of some alkoxyalkylthiobenzenes, 1,2-di-(methylthio)benzenes, 2,4,6-trimethyl-1-methylthiobenzen and 2-amino-1-methylthiobenzen in HSO₃F and SbF₅-HSO₃F solutions was studied by low-temperature ¹H NMR spectroscopy. The sites of protonation (S-v.s. C-) were dependent upon the substituents in the ring and the acid media. The structures of the formed ions were assigned on their ¹H NMR spectra. Sulfonium ions (S-protonated sulfides) formation was generally observed in HSO₃F solution at low-temperature (–60^oC). Some alkoxyalkythiobenzenes in strongest superacid media (SbF₅-HSO₃F) behave as ambident bases protonating both on sulfur and on carbon atom in para-position to the alkoxy group of benzene ring, forming diprotonated ions. But the dimethoxymethylthiobenzenes in superacid media were observed only as benzenium ions (protonation in benzene ring).

Keywords: prototnation; superacid; aromatic sulfide; ¹H NMR spectroscopy

R e z i m e

PROTONIRAWE NA ALKILARIL-SULFIDI VO RASTVORI NA FLUOROSULFONSKA I ANTIMONPENTAFLUORID-FLUOROSULFONSKA KISELINA

Katica ^olan~eska-Ra|enovi}¹, Mirjana Eckert-Maksi}² i @eljko Marini}²

Klu~ni zborovi: protonirawe; superkiselina, aromati~en sulfid; ¹N NMR spektroskopija

Ispituvana e reakcijata na protonirawe na nekoi alkoksi-alkiltiobenzeni, di(metiltio)benzeni i metil i amino supstituiran benzen vo rastvori na HSO₃F i 10% SbF₅-HSO₃F so pomo{ na nisko temperaturna ¹H NMR spektroskopija. Sledeno e vlijanieto na supstituentot, na promenata na superkiselinskiot rastvor i na temperaturata vrz nasokata na protoniraweto. Vo rastvori na HSO₃F alkoksialkiltiobenzenite glavno se protonirani na sulfurniot atom formiraj}i joni na sulfonium so lokaliziran pozitiven polne`, osven dimetoksimetiltiobenzenite koi se protonirani na jaglerodniot atom od benzenskiot prsten do soodvetni joni na benzenium i pozitivniot polne` e delokaliziran na prstenot. Vo rastvor na 10% SbF₅-HSO₃F alkoksialkiltiobenzenite se odnesuvaat kako ambidentni bazi; tie se diprotonirani vrzuvaj}i go kiselinskiot proton i na sulfurniot i na jaglerodniot atom od benzenskiot prsten vo para-polo`ba vo odnos na alkoksi-grupata.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 15–20 (1999)

GHTMDD – 321 ISSN 0350 – 0136

Received: December 12, 1998 UDC: 547.584 : 542.949.41.094.7]: 543.422

Accepted: April 14, 1999

The kinetics of the hydrolysis of N-(4-R-phenylaminomethyl)-phthalimide (R = H; OCH₃; CH₃; Cl; Br) were studied spectrophotometrically in aqueous sodium hydroxide solutions. The rate of hydrolysis shows a small dependence on the concentration of hydroxide ion in the pH region 9.35–13.70. The effect of para substituent (R) on benzene ring on the reaction rate constants of hydrolysis obeys Hammett`s relationship.

Keywords: N-substituted phthalimides; alkaline hydrolysis; kinetics

R e z i m e

SPEKTROFOTOMETRISKO PROU^UVAWE NA KINETIKITE NA ALKALNA HIDROLIZA NA NEKOI N-SUPSTITUIRANI FTALIMIDI

Klu~ni zborovi: N-supstituirani ftalimidi; alkalna hidroliza; kinetika

Spektrofotometriski bea izu~uvani kinetikite na hidroliza na N-(4-R-fenilaminometil)-ftalimid (R=H; OCH₃; CH₃; Cl; Br) vo vodni rastvori na natrium hidroksid. Stepenot na hidrolizata poka`uva mala zavisnost od koncentracijata na hidroksidniot jon vo rN so opseg 9,35 ‡ 13,70. Efektot na supstituentite vo benzenskoto jadro vrz reakcioniot stepen na konstantite na hidroliza e vo korelacija so Hammett-ovata ravenka.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 21–30 (1999)

GHTMDD – 322 ISSN 0350 – 0136

Received: July 15, 1998 UDC: 669.334.43 : 544.42.001.573

Accepted: April 27, 1999

Cvetanka Kuzmanovska¹, Filimena Poposka and Aleksandar Grizo

A mathematical model for dump leaching of complex sulfide ores is presented. This model is suitable for description of the kinetics of ore sample consisting of various minerals (chalcocite, covellite, chalcopyrite, pyrite) as a function of the concentration of ferric ions in the leaching solution. Leaching occurs as a mixed kinetics including surface chemical reaction and diffusion through the pores of the ore particle.

Keywords: copper sulfide ores; leaching; mathematical modeling

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 31–36 (1999)

GHTMDD – 323 ISSN 0350 – 0136

Received: December 26, 1998 UDC: 582.29 : [546.815–71 : 534.422

Accepted: April 4, 1999

Ömer Saltabas, Ferda Yesilcimen and Göksel Akcin*

Factors affecting the uptake of Pb(II) from aqueous solution by biomass of dried lichens Usnea florida, Dermatocorpon miniatum, Dermatocorpon intestiniforme and Pseudeuernia furfuracea were investigated. Lead binding capacity increased with decreasing particle size. The maximum Pb(II) uptake was found to occur in 10–30 minutes. The amount of Pb(II) bound increased with initial lead concentration. The pH of the solution had a strong effect on the uptake of lead ions for all studied lichens. Binding was a minimum at pH 2, but increased rapidly with increasing pH. Lead binding was completely blocked in the presence of EDTA for all lichens studied. Generally both acidic and basic pretreatment increased Pb(II) binding except acidic pretreatment of Dermatocorpon intestiniforme and basic pretreatment of Usnea florida. Coincidental metal ions namely zinc, copper and chromium increased the binding of lead ions for all lichens studied.

Keywords: biosorption; lichen; biomass; lead

Ömer Saltabas, Ferda Yesilcimen i Göksel Akcin

Vo trudot se ispituvani faktori {to vlijaat vrz vrzuvaweto na Pb(II) prisutno vo vodni rastvori od suva biomasa na li{aite Usnea florida, Dermatocorpon miniatum, Dermatocorpon intestiniforme i Pseudeuernia furfuracea. Kapacitetot na vrzuvawe na olovoto se zgolemuva so namaluvawe na goleminata na ~esti~kite. Vrzuvaweto e najgolemo vo interval od 10 do 30 minuti. Koli~estvoto Pb(II) {to se vrzuva se zgolemuva so zgolemuvawe na negovata po~etna koncentracija. rN na rastvorot ima silno vlijanie vrz vrzuvaweto na olovnite joni kaj site ispituvani li{ai. Vrzuvaweto e najmalo pri rN 2, no se zgolemuva so zgolemuvawe na rN.

Vrzuvaweto na olovoto e potpolno blokirano vo prisustvo na EDTA vo site ispituvani slu~ai. I obata pretretmani go zgolemija vrzuvaweto na Pb(II) so isklu~ok na kiselinskiot pretretman na Dermatocorpon intestiniforme i pretretmanot so baza na Usnea florida. Metalnite joni na cinkot, bakarot i hromot go zgolemija vrzuvaweto na olovnite joni kaj site ispituvani li{ai.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 37–40 (1999)

GHTMDD – 324 ISSN 0350 – 0136

Received: February 15, 1999 UDC: 612.126.711 : 543.422

Accepted: May 5, 1999

Konstantin Mutaftchiev¹, Kamen Tzachev² and Alexander Alexiev¹

A new catalytic spectrophotometric method for determination of manganese(II) in human blood serum was developed. The method is based on a catalytic reaction for determination of manganese(II) through oxidation of sulphanilic acid by potassium periodate with 1,10-phenanthroline as activator. Manganese in the range 0.2–6.0 ng ml^–1 can be determined, and the detection limit is 0.1 ng ml^–1. The relative standard deviation is 5.6 % for ten determinations of 0.86 ng ml^–1 of manganese(II). The method was applied successfully for determination of manganese in blood serum of subjects with gastrointestinal disorders. The results showed reasonable agreement with those obtained by ETAAS.

Keywords: manganese(II) determination; human blood serum; catalytic spectrophotometric method; sulphanilic acid oxidation; periodate

R e z i m e

SPEKTROFOTOMETRISKI KATALITI^KI METOD ZA OPREDELUVAWE NA MANGAN(II) VO SERUM OD ^OVE^KA KRV

Konstantin Mutaftchiev¹, Kamen Tzachev² i Alexander Alexiev¹

Klu~ni zborovi: opredeluvawe na mangan(II); serum od ~ove~ka krv; kataliti~ka reakcija; spektrofotometrija; oksidacija na sulfanilna kiselina; kaliumperjodat

Razvien e nov spektrofotometriski kataliti~ki metod za opredeluvawe na mangan(II) vo serum od ~ove~ka krv. Metodot se bazira na kataliti~ka reakcija za opredeluvawe na mangan(II) preku oksidacija na sulfanilna kiselina so kalium perjodat i 1,10-fenantrolin kako aktivator. Na ovoj na~in mo`e da se opredeli Mn(II) vo koncentracisko podra~je od 0,2 do 6,0 ng ml^–1 (granicata na detekcija e 0,1 ng ml^–1). Pri 10 merewa na obrazec so 0,86 ng ml^–1 Mn(II), relativnata standardna devijacija iznesuva 5,6 %. Metodot e uspe{no primenet za opredeluvawe na Mn vo krven serum na lica so gastrointestinalni naru{uvawa. Rezultatite se vo zadovolitelna soglasnost so tie dobieni so ETAAS.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 41–45 (1999)

GHTMDD – 325 ISSN 0350 – 0136

Received: Ocober 21, 1998 UDC: 547.26–185 : 531.756

Accepted: March 17, 1999

The densities for chloroform+2-propanol+2-butanol and 2-propanol+2-butanol+ethanol ternary liquid systems were determined under the full range of composition at 20, 25, 30, and 35 ^oC, and atmospheric pressure. An existing predictive equation for the ternary liquid mixture densities has been tested.

Keywords: density; ternary liquid mixture; empirical equation; aliphatic alcohol

Opredeleni se eksperimentalni podatoci za gustinata na trikomponentnite te~ni smesi: hloroform+2-propanol+2-butanol i 2-propanol+2-butanol -etanol na temepraturi od 20, 25, 30 i 35 ^oS pri atmosferski pritisok. Ispituvano e vlijanieto na temperaturata vrz gustinata na te~nite smesi. Eksperimentalnite podatoci za gustina se korelirani so ravenkata na Paschke et al. [2] koja dava dobro soglasuvawe na presmetanite i merenite vrednosti.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 47–50 (1999)

GHTMDD – 326 ISSN 0350 – 0136

Received: November 16, 1998 UDC: 547.462 : 543.422.6

Accepted: March 19, 1999

Katica Jankovska*, Ilinka Spirevska and Lidija Šoptrajanova

The influence of the solvent on the protonation of citraconic and mesaconic acid in aqueous and ethanolic solutions of H₂SO₄ was investigated using spectrophotometric methods. The spectra were recorded, in the 190–300 nm region, from solutions with a constant concentration of the organic acid (1.0 · 10^–4 mol dm^–3 in the case of citraconic and 2.4 · 10^–4 mol dm^–3 for mesaconic acid) and increasing concentration of H₂SO₄ (from 1.0 to 17.5 mol dm^–3). It was found that in the case of citraconic acid at H₂SO₄ concentrations higher than 8 mol dm^–3 protonation and dehydratation take place the latter leading to the formation of protonated citraconic anhydride. In the case of mesaconic acid (the geometrical isomer of citraconic acid) only the protonation reaction takes place, most probably because of the trans arrangement of the carboxyl groups in it. The solvent effect is considerable and in ethanolic solutions the protonation reaction is both initiated and terminated at lower concentration of the proton donor (H₂SO₄).

Keywords: citraconic acid; mesaconic acid; protonation; dehydratation; UV spectroscopy

Ispitano e vlijanieto na rastvoruva~ot vrz protonirawe na citrakonska i mezakonska kiselina vo vodni i etanolni rastvori na sulfurna kiselina so primena na spektrofotometriskiot metod. Bea snimeni spektrite na serija od rastvori vo koi koncentracijata na organskata kiselina be{e konstantna (za citrakonska kiselina 1,0 · 10^–4 mol dm^–3, a za mezakonska kiselina 2,4 · 10^–4 mol dm^–3), dodeka koncentracijata na H₂SO₄ be{e raste~ka i se dvi`e{e od 1 do 17,5 mol dm<sup>–3</sup>. Od dobienite rezultati be{e konstatirano deka pri koncentracii na H<sub>2</sub>SO<sub>4</sub> pogolemi od 8 mol dm<sup>–3</sup> kaj citrakonskata kiselina osven reakcijata na protonirawe se odviva i reakcijata na dehidratacija, pri {to se formira protoniran anhidrid. Kaj geometriskiot izomer na citrakonskata kiselina (mezakonskata kiselina) se odviva samo reakcija na protonirawe {to najverojatno se dol`i na transrasporedot na karboksilnite grupi vo nea. Izu~uvawata na reakcijata na protonirawe vo vodni i etanolni rastvori na sulfurna kiselina poka`aa deka vlijanieto na rastvoruva~ot e zna~itelno. Imeno, vo etanolni rastvori reakcijata na protonirawe e popotpolna, t.e. zapo~nuva i zavr{uva pri poniski koncentracii na proton-donorot (H₂SO₄).

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 51–55 (1999)

GHTMDD – 327 ISSN 0350 – 0136

Received: May 15, 1998 UDC: 546.733–386

Accepted: April 2, 1999

Tibor J. Sabo^1*, Lidija V. Popovi}¹ and Sre}ko R. Trifunovi}²

Klu~ni zborovi: kobalt(III) kompleksi; etilendiamin-N-N'-di-3-propionska kiselina, S-norvalin

Vrz osnova na dve teoretski mo`nosti za geometriska izomerija, facijalna i meridijalna, sintetizirani se kompleksi na uns-cis-(etilendiamin-N-N'-di-3-propionato)(S-norvalinato)-kobalt(III) vo reakcija na natrium-uns-cis-(etilendiamin-N,N'-di-3-propionato)kobaltat(III)dihidrat so Y-norvalin na 70 ^oS. Ovie komleksni soedinenija, hromatografski se izolirani i karakterizirani so elementarna analiza, UV/VIS spektrofotometrija.

Bulletin of the Chemists and Technologists of Macedonia, Vol. 18, No. 1, pp. 57–64 (1999)

GHTMDD – 328 ISSN 0350 – 0136

Received: November 16, 1998 UDC: 543.552 : 004.42

Accepted: March 19, 1999

Valentin Mir~eski, Rubin Gulaboski and Igor Kuzmanovski

An alternative approach for numerical calculation of the square-wave voltammograms using the mathematical programming package MATHCAD is presented. A quasi-reversible redox reaction is considered and a mathematical model is developed under conditions of the square-wave voltammetry (SWV). Application of the mathematical model in MATHCAD is discussed and the file used for numerical simulation is presented. The relationships between the properties of the SW response and the parameters of both the quasireversible redox reaction and the excitation signal are discussed.

Keywords: MATHCAD; square-wave voltammograms; numerical calculation

R e z i m e

NUMERI^KO SIMULIRAWE NA KVADRATNO-BRANOVI VOLTAMOGRAMI SO MATHCAD

Klu~ni zborovi: MATHCAD; kvadratno-branovi voltamogrami; numeri~ki presmetki

Prezentiran e alternativen na~in za numeri~ko simulirawe na kvadratno-branovi voltamogrami so primena na matemati~kiot programski paket MATHCAD. Razvien e matemati~ki model za kvazireverzibilna redoks-reakcija vo uslovi na kvadratno-branova voltametrija. Diskutiran e na~inot na koj mo`e matemati~kiot model da bide inkorporiran vo programskiot paket MATHCAD. Pokraj toa, prika`ana e kompletnata datoteka {to e koristena za simulirawe na ekscitacioniot signal i za numeri~ko simulirawe na voltametriskiot odgovor. Prou~eni se teoretskite funkcionalni zavisnosti pome|u parametrite na kvadratno-branoviot odziv i kineti~kite parametri na redoks-reakcijata, kako i parametrite na ekscitacioniot signal.

GHTMDD – 329 ISSN 0350 – 0136

Pristignato: 16 noemvri 1998 UDK: 004.6 : 66

Hemiskiot in`ener ja koristi postapkata za simulacija za da izvr{i mnogu va`ni raboti, po~nuvaj}i od presmetka na materijalni i energetski bilansi na procesnite {emi, pa sè do predviduvawe na performansite na procesnite alternativi.

S u m m a r y

PHYSICAL PROPERTIES DATA BANKS

Vera Me{ko and Liljana Markovska

Keywords: physical property; methods; analysis; estimation; data banks

In process simulation a number of important tasks are performed, ranging from calculation of mass and energy balances of large flowsheets to performance predictions of process alternatives. Using physical properties data banks, the process engineer can swiftly define a complex flowsheet and all the process conditions.

Missing or inadequate physical properties data may undermine the accuracy of a model or even prevent the engineer from performing the simulation. In this article we give practical tips and techniques to help the engineer describe accurately the physical properties data needed for a simulation.

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