Chemistry Journal of Moldova. General, Industrial and Ecological Chemistry

7-8

Authors: Gheorghe DUCA

Ten years ago, in 2006, CHEMISTRY JOURNAL OF MOLDOVA. General, Industrial and Ecological Chemistry was founded by the Institute of Chemistry of Academy of Sciences of Moldova and Moldova State University. Chemistry Journal of Moldova is an open access, international indexed and peer-reviewed journal that publishes papers of high quality containing original results in the areas of Chemical Sciences, such as analytical chemistry, ecological chemistry, food chemistry, industrial chemistry, inorganic and coordination chemistry, natural product chemistry and synthesis, organic chemistry, physical chemistry and chemical physics, as well as supramolecular chemistry. Chemistry Journal of Moldova seeks to publish experimental or theoretical research results of outstanding significance and timeliness.

10-16

Authors: Gheorghe DUCA , Lidia ROMANCIUC

Organization of the ECOLOGICAL CHEMISTRY Conferences in Chisinau, Republic of Moldova transformed into important tradition and represent a series of successful conferences occurred in 1995, 2002, 2005, 2008, 2010 and 2012 being supported by UNESCO, UNEP, CRDF/MRDA, CEI, NATO, ONRG, as well as the local R&D organizations such as the Academy of Sciences of Moldova, Department of Industrial and Ecological Chemistry, Scientific Centre for Ecological and Applied Chemistry, Faculty of Chemistry and Chemical Technology of the Moldova State University, Institute of Chemistry of Academy of Sciences of Moldova, Chemical Society of Republic of Moldova, Moldovan Research and Development Association, etc. The list of the organized Conferences till 2016 and the forthcoming 6th International Conference on Ecological & Environmental Chemistry (2-3 March 2017.

26-33

Authors: Mihai Ciobanu, Victor Botan, Tudor Lupascu, Tatiana Mitina, Maria Rusu

Adsorption of strontium ions from aqueous solutions on active carbons CAN-7 and oxidized CAN-8 has been studied. It has been found that allure of the adsorption isotherms for both studied active carbons are practically identical. Studies have shown that the adsorption isotherms for strontium ions from aqueous solutions are well described by the Langmuir and Dubinin-Radushkevich equations, respectively. The surface heterogeneity of activated carbons CAN-7 and oxidized CAN-8 has been assessed by using Freundlich equation.

46-51

Authors: Iryna Laguta, Teteiana Fesenko, Oksana Stavinskaya, Oksana Dzjuba, Lesya Shpak

Three extracts of Stevia rebaudiana (Bertoni) were prepared using various types of raw materials: leaves of plants grown ex situ, leaves of plants grown in vitro, callus culture formed on damaged leaves. Composition of the extracts, their activity in the synthesis of silver nanoparticles colloids, as well as antioxidant and antimicrobial properties of the extracts and the colloids were investigated.

58-67

Authors: Demet Gürbüz, Aydin Tavman, Adem Cinarli, Ismail Boz

5,6-Dichloro/dimethyl-2-(2´,3´/2´,4´/2´,5´/3´,4´/3´,5´-dimethoxyphenyl)-1H-benzimidazoles were synthesized and characterized by using analytical data, FT-IR, FT-Raman, NMR, ESI-MS and fluorescence spectroscopy. The optimized molecular geometry, zero point energy, dipole moment, ESE, band gap and charge distributions were calculated by Gaussian 09 using Density Functional Theory (DFT, RB3LYP) with 6-31++G(d,p) basis set. According to the calculations, the molecules have structures with various torsion angles between the benzimidazole and benzene rings from 9.7º to 47.8º. The calculated energy values with ZPE correction and DFT show that the methyl derivatives are more stable than the chloro forms. 3´,4´-Dimethoxy derivatives have higher decomposition points in comparison with the other compounds in series. The chlorine atoms of 5,6-dichloro-2-(2´,3´/2´,4´/2´,5´/3´,4´/3´,5´-dimethoxyphenyl)-1H-benzimidazoles are positively charged whereas the C5 and C6 carbon atoms are negatively charged due to the attached chlorine atoms, in virtue of the electron withdrawing characteristic of the imidazole part of the benzimidazole ring. Also, some calculated prominent bond lengths and bond angles were discussed.

74-83

Authors: Dalila Badis, Zoubir Benmaamar, Othmane Benkortbi, Houcine Boutoumi, Houria Hamitouche, Amele Aggoun

The feasibility of using medicinal plants species Retama raetam as a low cost and an eco-friendly adsorbent for the adsorption of cationic dye methylene blue from simulated aqueous solution has been investigated. Adsorption kinetics of methylene blue onto Retama raetam plants was studied in a batch system. The effects of pH and contact time were examined. The methylene blue maximum adsorption occurred at pH 8 and the lowest adsorption occurred at pH 2. The apparent equilibrium was reached after 120 min. Optimal experimental conditions were determined. Adsorption modelling parameters for Freundlich and Langmuir isotherms were determined and, based on R2, various error distribution functions were evaluated as well. Adsorption isotherm was best described by non linear Freundlich isotherm model. Thermodynamic studies show that adsorption was spontaneous and exothermic. For determining the best-fit-kinetic adsorption model, the experimental data were analyzed by using pseudo-first-order, pseudo-second-order, pseudo-third-order, Esquivel, and Elovich models. Linear regressive and non-linear regressive method was used to obtain the relative parameters. The statistical functions were estimated to find the suitable method that fit better the experimental data. Both methods were appropriate for obtaining the parameters. The linear pseudo-second-order (type 9 and type 10) models were the best to fit the equilibrium data. The present work showed that plant Retama raetam can be used as a low cost adsorbent for the removal of methylene blue from water.

93-98

Authors: Tudor Spataru, Francisco Fernandez, Joseph W. Sista, Petru Spataru, Igor Povar

Geometry optimizations at the UBP86/6-311++G** level of electronic structure theory have been performed for DDT, β-hexachlorocyclohexane, and heptachlor organic polychlorides as well for their positive and negative ions. The HOMO composition of these neutral molecules show no participation of the carbon-chlorine atomic orbitals, while LUMO of the calculated molecules include a major contribution of the anti-bonding character atomic orbitals from the two or three carbon-chloride bonds of each calculated molecule. Consequently, the negative ions were the most sensitive structure during the geometry optimization, showing the carbon-chloride bonds cleaving during the electronic structure calculations. Further geometry optimization of the obtained neutral intermediate molecules after the first and second reducing by two electrons show that the electrochemical dehalogenation of the organic poychlorides is sequential.

105-108

Authors: Ion Dragalin, Aculina Aricu, Nina Ciocarlan, Alexandru Ciocarlan, Victoria Codita

For the fi rst time the results of GC-MS analysis of Satureja subspicata L. oil of Moldovan origin are reported. The chemical profi le includes forty-four constituents and consists mostly (97.86%) of phenolic monoterpenes, monoterpene hydrocarbons, bicyclic sesquiterpenes and their oxygenated derivatives. A substantial quantitative and qualitative chemical differentiation of S. subspicata oil of Moldovan origin and reported oil of Croatian origin were found. The essential oil of S. subspicata L. plants cultivated in Republic of Moldova belongs to the carvacrol chemotype.

10-20

Authors: Tudor Spataru, Francisco Fernandez

No grounded mechanisms for Co-C vitamin B12 coenzyme bond breaking process and subsequent reactions have been found up to now. The influence of the mixing orbitals e.g. Pseudo-Jahn-Teller and similar effects on the reactions paths of bond-cleavage mechanisms of vitamin B12 co-factors must be taken into account. Afterward, the updated mechanisms of vitamin B12 bio-processes can be determined.

27-32

Authors: Larisa Postolachi, Vasile Rusu, Tudor Lupascu

Aluminium sulphate is one of the most widely used coagulants for water treatment and has been proven to be an effective coagulant for the removal of certain contaminants, turbidity and colour. Aluminium sulphate used during the coagulation process is hydrolyzed in the water, forming polynuclear complexes. Aged aluminium solutions show different coagulation behaviour than that of freshly prepared solutions. Obtained results reveal that using of optimal aging solution of coagulant improves the coagulation process.

39-49

Authors: Ion Bulhac, Alexandra Deseatnic-Ciloci, Paulina Bourosh, Janetta Tiurina, Olga Bologa, Cezara Bivol, Steliana Clapco, Ana Verejan, Svetlana Labliuc, Olga Danilescu

Four coordination compounds of iron(III) with ligands based on hydrazine and sulfadiazine: FeCl3·digsemi·2H2O (I) (digsemi-semicarbazide diacetic acid dihydrazide, [Fe(HL)SO4] (II) (НL - sulfadiazine), [Fe(H2L1)(H2O)2](NO3)3·5H2O (III) (H2L1-2,6-diacetylpyridine bis(nicotinoylhydrazone) and [Fe(H2L2)(H2O)2](NO3)3•1.5H2O (IV) (H2L2 - 2,6-diacetylpyridine bis(isonicotinoylhydrazone) were synthesized. The spectroscopic and structural characterisation as well as their biological, properties are presented.

55-60

Authors: Sofiane Daoudi, Tahar Benaissa, Djallal Eddine Adli, Nisserine Hamini-Kadar

This study describes the synthesis of some novel compounds containing bis-1,3,4-oxadiazole bearing quaternary ammonium salt moieties. The newly synthesized compounds were evaluated for their antibacterial activity against various gram-positive and gram-negative strains of bacteria, and the antifungal activities were tested against three phytopathogenic fungi namely, Fusarium oxysporum, Fusarium commune and Fusarium rodelens.

69-73

Authors: Sharali Malik, Ian James Hewitt, Annie Katherine Powell

We have synthesized a variety of magnetite nanoparticles which appear to have biogenic signatures and could give insights into how the nanomagnetite particles form in biological systems, and how they are associated with Alzheimer’s disease. We have also synthesized mesoporous magnetite nanoparticles which have potential use in the targeted drug delivery.

86-90

Authors: Nicolay Davidenko, Irina Davidenko, Oleg Korotchenkov, Victor Kravchenko, Elena Mokrinskaya, Andrey Podolian, Sergey Studzinsky, Larisa Tonkopiyeva

Planar organic heterostructures were prepared using poly-N- epoxypropylcarbazole films and poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylenevinylene] by the method of successive deposition adding 2,3,9,10,16,17,23,24-zinc octabutylphthalocyanine. Photoelectric, photodielectric and photovoltaic properties of the heterostructures were studied.

97-105

Authors: Alexei Baerle, Olga Dimova, Irina Urumoglova, Pavel Tatarov, Larisa Zadorojnai

Phase state and the charge of colloidal particles in the gelatine-polyuronate system were studied. A method for comparative evaluation of molecular weight of colloids by means of viscosimetric measurements and electrophoresis was developed. It is shown that the Diagram {Phase state = f (composition, pH)} contains six well-defined regions. The diagram explains and predicts the behaviour of protein-polysaccharide colloids, which are included in beverages or forms the shells of oil-containing microcapsules.