Vol 80, No 10 - Abstracts

JSCS Vol 80, No 10

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Whole issue - PDF 2,247 kB

J. Serb. Chem. Soc. 80 (10) 1217–1249 (2015)

UDC 547.291+542.943:546.92’87+544.478; JSCS–4792; doi: 10.2298/JSC150318044P; Review

REVIEW

Formic acid oxidation at platinum–bismuth catalysts

KSENIJA Đ. POPOVIĆ AND JELENA D. LOVIĆ

ICTM – Institute of Electrochemistry, University of Belgrade, Njegoševa 12, P. O. Box 473, 11000 Belgrade, Serbia

(Received 18 March, revised 24 April, accepted 5 May 2015)

The field of heterogeneous catalysis, specifically catalysis on bimetallic surfaces, has seen many advances over the past few decades. Bimetallic catalysts, which often show electronic and chemical properties that are distinct from those of their parent metals, offer the opportunity to obtain new catalysts with enhanced selectivity, activity, and stability. The oxidation of formic acid is of permanent interest as a model reaction for the mechanistic understanding of the electro-oxidation of small organic molecules and because of its technical relevance for fuel cell applications. Platinum is one of the most commonly used catalysts for this reaction, despite the fact that it shows a few significant disadvantages, such as high cost and extreme susceptibility to poisoning by CO. To solve these problems, several approaches have been used, but generally, they all consist in the modification of platinum with a second element. Especially, bismuth has received significant attention as a Pt modifier. According to the results presented in this review dealing with the effects influencing formic acid oxidation, it was found that two types of Pt–Bi bimetallic catalysts (bulk and low loading deposits on GC) showed superior catalytic activity in terms of lower onset potentials and oxidation current densities, as well as exceptional stability compared to Pt. The findings in this report are important for an understanding of the mechanism of formic acid electro-oxidation on the bulk alloy and decorated surface, for the development of advanced anode catalysts for direct formic acid fuel cells, as well as for the synthesis of novel low-loading bimetallic catalysts. The use of bimetallic compounds as anode catalysts is an effective solution to overcoming the problems of current stability in the oxidation of formic acid during long-term applications. In the future, the tolerance of both CO poisoning and electrochemical leaching should be considered as the key factors in the development of electrocatalysts for anodic reactions.

Keywords: formic acid oxidation; Pt–Bi catalysts; alloy; metal clusters; fuel cell anode catalysts.

Full Article - PDF 923 kB Available OnLine: 24. 05. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1251–1264 (2015)

UDC 547.556.9+66.095.252.094.3:541.124:547.791’821:615.277; JSCS–4793; doi: 10.2298/JSC141222022G; Original scientific paper

Antimicrobial and anticancer evaluation of a novel synthetic tetracyclic system obtained by Dimroth rearrangement

SOBHI M. GOMHA, IKHLASS M. ABBAS, MOHAMED A. A. ELNEAIRY, MAHMOUD M. ELAASSER* and BAZADA K. A. MABROUK

Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt

*Regional Center for Mycology and Biotechnology, Al-Azhar University, Cairo, Egypt

(Received 22 December 2014, revised 18 February, accepted 4 March 2015)

A series of pyrido[3′,2′:4,5]thieno[2,3-e][1,2,4]triazolo[4,3-c]pyrimidines were prepared via oxidative cyclization of 4-(2-arylidenehydrazinyl)pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidines. Dimroth rearrangement of such a series yielded pyrido[3′,2′:4,5]thieno[2,3-e][1,2,4]triazolo[1,5-c]pyrimidines. A reaction mechanism was proposed and the products were screened for their antimicrobial and anticancer activities. From the antimicrobial screening results, it could be seen that compounds 8c, 9f and 10c showed excellent activity against Gram-positive bacteria while compounds 10d and 8c showed the highest activity against Gram-negative bacteria. The results of the anticancer activities showed that compound 9c was the most active against HepG-2 and MCF-7 with IC50 values of 1.19 and 3.46 μg/mL, respectively.

Keywords: hydrazones; oxidative cyclizations; thienopyridines; reaction mechanism.

Full Article - PDF 333 kB Supplementary Material PDF 283 kB Available OnLine: 13. 03. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1265–1272 (2015)

UDC 547.75’81’77:542.913+544.351–145.82+546.284–31; JSCS–4794; doi: 10.2298/JSC140930045M; Original scientific paper

Green one-pot, four-component synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives using amino-functionalized nanoporous silica SBA-15 under solvent-free conditions

GHODSI MOHAMMADI ZIARANI, MAHSHID RAHIMIFARD, FATEMEH NOURI AND ALIREZA BADIEI*

Department of Chemistry, Alzahra University, Vanak Square, P. O. Box 19938939973, Tehran, Iran

*School of Chemistry, College of Science, University of Tehran, Tehran, Iran

(Received 30 September 2014, revised 18 May, accepted 24 May 2015)

Propylamine functionalized nanoporous silica (SBA–Pr-NH2) was used as an efficient heterogeneous solid basic nanoreactor in the synthesis of 6′-amino-1′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazol]-2-one derivatives 5 through a one-pot, four-component condensation of isatin derivatives 1, activated methylene reagents 2, hydrazine hydrate 3 and β-keto esters 4 under solvent-free conditions at room temperature.

Keywords: amino-functionalized nanoporous silica; solvent-free; nanoporous silica; four components; one-pot; spiro indole; pyranopyrazole.

Full Article - PDF 293 kB Supplementary Material PDF 136 kB Available OnLine: 22. 06. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1273–1278 (2015)

UDC 547.451.63’454+66.095.253:547.415.1; JSCS–4795; doi: 10.2298/JSC150224033H; Original scientific paper

Alkylating ability of carbohydrate oxetanes: Practical synthesis of bolaform skeleton derivatives

PAVLE A. HADŽIĆ, MIRJANA M. POPSAVIN* and SUNČICA Z. BOROZAN**

Goša Institute, Milana Rakića 35, 11000 Belgrade, Serbia

*Faculty of Sciences, Department of Chemistry, University of Novi Sad, Trg D. Obradovića 3, 21000 Novi Sad, Serbia

**Faculty of Veterinary Medicine, University of Belgrade, Bulevar oslobođenja 18, 11000 Belgrade, Serbia

(Received 24 February, revised 30 March, accepted 16 April 2015)

The alkylating ability of the oxetane ring in the carbohydrate structure was investigated and a flexible method for the construction of a bolaform amphiplile skeleton with xylose as the polar head is proposed. The method is based on oxetane ring opening in the easily accessible 3,5-anhydro-1,2-O-cyclohexylidenexylofuranose (1). One-step nitrogen alkylation in terminal diamines with 1 gave the basic cationic bolaform skeleton with xylose as potential polar head and a deliberately chosen length of the non-polar spacer. Under similar experimental conditions, but with an appropriate mole ratio of the alkylating agent, the alkylation reaction provide for selective monoalkylation of the diamines. Successful alkylation in the xanthine series (theophylline) was also achieved with 1, giving a new 5-deoxy-5-(1,2,3,6-tetrahydro-1,3-dimethyl-2,6-dioxo-7H-purin-7-yl)-α-D-xylofuranose derivative.

Keywords: bolaform skeleton; oxetane ring; alkylation; ring opening.

Full Article - PDF 250 kB Supplementary Material PDF 153 kB Available OnLine: 10. 05. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1279–1288 (2015)

UDC 582.282.123.4:547.454:664.644.5+663.142/.143:577.15.002.2+633.11’13; JSCS–4796; doi: 10.2298/JSC150317043D; Original scientific paper

Enhancement of amylase production by Aspergillus sp. using carbohydrates mixtures from triticale

BILJANA DOJNOV, MARICA GRUJIĆ*, BOJANA PERČEVIĆ* and ZORAN VUJČIĆ*

Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, Belgrade, Serbia

*Department of Biochemistry, Faculty of Chemistry, University of Belgrade, Studentski trg 12–16, Belgrade, Serbia

(Received 17 March, revised 7 May, accepted 12 May 2015)

With the purpose of finding a suitable available inducer in combination with starvation, carbohydrate mixtures from triticale were used and compared with well-known amylase inducers in fungi. Carbohydrate mixtures from triticale induced the production of an amylase cocktail (α-amylase and glucoamylase) in Aspergillus niger, unlike induction with well-known inducers that induce only glucoamylase, shown by zymography and TLC analysis of the carbohydrate mixtures before and after fermentation. Glucoamylase production by A. niger was the highest in the presence of the extract obtained after autohydrolysis of starch from triticale (95.88 U mL-1). Carbohydrate mixtures from triticale induced the production of α-amylase in A. oryzae. More α-amylase isoforms were detected when using a complex carbohydrate mixture, compared to induction with maltose or starch. A 48-h induction was the most efficient using a triticale extract (101.35 U mL-1). Carbohydrates from triticale extracts could be used as very good cheap amylase inducers. Triticale, still not fully utilized, could be taken into consideration as an inducer in amylase production by Aspergillus sp, and in such a way, it could be used as the sole substrate in fermentation.

Keywords: α-amylase; glucoamylase; maltose; starch; enzyme production; fungi.

Full Article - PDF 334 kB Available OnLine: 24. 05. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1289–1295 (2015)

UDC 546.472+539.216:548.7:536.5.004.12:535.37; JSCS–4797, doi: 10.2298/JSC150204049W; Original scientific paper

A new zinc(II) supramolecular square: synthesis, crystal structure, thermal behavior and luminescence

XIU-YAN WANG, ZHONG-YU ZHAO, QIAN HAN, MIAO YU and DE-YU KONG

Key Laboratory of the Preparation and Application of Environmental Friendly Materials, Ministry of Education, College of Chemistry, Jilin Normal University, Siping 136000, China

(Received 4 February, revised 8 May, accepted 6 June 2015)

A new square-shaped Zn(II) complex, [Zn4(L)4(phen)4]·6H2O (1, L = 2-hydroxynicotinate and phen = 1,10-phenanthroline), was synthesized under hydrothermal condition. The crystal of 1 belongs to triclinic, space group P–1 with a = 10.773(2) Å, b = 12.641(3) Å, c = 13.573(3) Å, α = 107.44(3)°, β 102.66(3)°, γ = 93.89(3)°, C72H56N12O18Zn4, FW = 1638.77, V = 1702.8(6) Å3, Z = 1, Dc = 1.598 g/cm3, S = 1.045, μ(MoKα) = 1.475 mm-1, F(000) = 836, R = 0.0472 and wR = 0.0919. Four L ligands bridge four Zn(II) atoms to form a square-shaped structure, where four phen ligands are respectively located on the four corners of the square. The π–π stacking interactions extend adjacent squares into a 1D supramolecular chain. The thermal behavior of 1 was characterized. Moreover, the solid-state luminescence property of the complex was studied at room temperature.

Keywords: crystal structure; supramolecular square; luminescence; 2-hydroxynicotinate.

Full Article - PDF 261 kB Supplementary Material PDF 129 kB Available OnLine: 22. 06. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1297–1309 (2015)

UDC 547.216+541.183+549.67:536.51:536.75; JSCS–4798 doi:10.2298/JSC150203032H; Original scientific paper

Effect of transition metal cations on the commensurate freezing of n-hexane confined in micropores of ZSM-5

RADMILA HERCIGONJA, VLADISLAV RAC*, VESNA RAKIĆ* and ALINE AUROUX**

Faculty of Physical Chemistry, University of Belgrade, 11000 Belgrade, Studentski trg 12, Serbia

*Faculty of Agriculture, Nemanjina 6, 11080 Belgrade-Zemun, Serbia

**Université Lyon 1, CNRS, UMR 5256, IRCELYON, Institut de recherches sur la catalyse et l’environnement de Lyon, 2 avenue Albert Einstein, F-69626 Villeurbanne, France

(Received 3 February, accepted 21 April 2015)

Besides its importance concerning fundamental studies on gas adsorption in narrow pores, investigation of the commensurate freezing of a fluid within a zeolite is of practical importance in the application of zeolites in the processes of adsorption, separation and catalysis. In this work, the adsorption of n-hexane on HZSM-5 and its transition metal ion-exchanged modified forms was studied at 303 K by means of microcalorimetry. The thermal molar entropies changes of adsorption were calculated and thereby, the freezing-like behaviour of n-hexane inside the structure of the zeolite as a confinement media was noticed. This effect is governed by the attractive interactions between n-hexane molecules and the pore walls, and is influenced by the length of the pores and the nature of the charge-balancing cations. Among the investigated zeolites, a solid-like phase of n-hexane in the pores of zeolites with Fe(II) ions was the most similar to solid bulk n-hexane, while Cu(II) ions contributed to the lowest ordering of the obtained solid-like n-hexane phase.

Keywords: confinement media; adsorption; entropy; microcalorimetry; ZSM-5.

Full Article - PDF 273 kB Available OnLine: 26. 04. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1311–1320 (2015)

UDC 543:615.2/.3:616.379–008.64:612.461:543.544.5.068.7:543.544–14; JSCS–4799; doi: 10.2298/JSC141227046R; Original scientific paper

Hollow-fiber micro-extraction combined with HPLC for the determination of sitagliptin in urine samples

RAHEME REZAEE, MAHNAZ QOMI and FOROOZAN PIROOZI

Medicinal Chemistry Department, Pharmaceutical Sciences Research Center, Pharmaceutical Sciences Branch, Islamic Azad University, Tehran, Iran

(Received 27 December 2014, revised 14 May, accepted 24 May 2015)

In this study, a three-phase, hollow-fiber, liquid-phase micro-extraction (HF–LPME) method coupled with high performance liquid chromatography was successfully developed for the determination of trace levels of the anti-diabetic drug sitagliptin (STG) in urine samples. Sitagliptin was extracted from 15 mL of the basic sample solution with a pH of 8.5 into an organic extracting solvent (n-octanol) impregnated in the pores of a hollow fiber and then back extracted into an acidified aqueous solution in the lumen of the hollow fiber with a pH of 3. After extraction, 20 µL of the acceptor phase was injected into HPLC system. In order to obtain high extraction efficiency, the parameters affecting the HF–LPME, including pH of the source and receiving phases, type of organic phase, ionic strength, stirring rate, extraction time, the volume ratio of donor phase to acceptor phase and temperature, were studied and optimized. Under the optimized conditions, enrichment factors up to 88 were achieved and the relative standard deviation of the method was in the range from 3 to 6 %. The results indicated that the HF–LPME method has an excellent clean-up capacity and a high pre-concentration factor and could serve as a simple and sensitive method for monitoring the drug in urine samples.

Keywords: anti-diabetic drug; drug analysis; chromatography; biological sample; pre-concentration.

Full Article - PDF 238 kB Available OnLine: 22. 06. 2015. Cited by

J. Serb. Chem. Soc. 80 (10) 1321–1338 (2015)

UDC 54(075.3)’’18’’:37(497.11); JSCS–4800; doi: 10.2298/JSC140926052M; Original scientific paper

Secondary-school chemistry textbooks in the 19^th century

VESNA D. MILANOVIC, DRAGICA D. TRIVIC* and BILJANA I. TOMASEVIC*

Innovation Centre of the Faculty of Chemistry, Studentski trg 12–16, Belgrade, Serbia

*University of Belgrade, Faculty of Chemistry, Studentski trg 12–16, Belgrade, Serbia

(Received 26 September 2014, revised 30 May, accepted 8 June 2015)

The teaching of chemistry in Serbia as a separate subject dates from 1874. The first secondary-school chemistry textbooks appeared in the second half of the 19th century. The aim of this study was to gain insight, by analysing two secondary-school chemistry textbooks, written by Sima Lozanić (1895) and Mita Petrović (1892), into the amount of scientific knowledge from the sphere of chemistry was presented to secondary school students in Serbia in the second half of the 19th century, and the principles textbooks written at the time were based on. Within the framework of the conducted research, we defined the criteria for assessing the quality of secondary-school chemistry textbooks were defined in the context of the time they were written. The most important difference found between the two textbooks under analysis pertained to the way in which their contents were organised. Sima Lozanić’s textbook is characterised by a greater degree of systematicness when it comes to the manner of presenting its contents and consistency of approach throughout the book. In both textbooks, the authors’ attempts to link chemistry-related subjects to everyday life, and to indicate the practical significance of various substances and their toxicity can be perceived.

Keywords: chemistry teaching; chemistry textbook; structural components of textbooks; textbook quality.

Full Article - PDF 260 kB Supplementary Material PDF 119 kB Available OnLine: 22. 06. 2015. Cited by

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