Chemistry Journal of Moldova. General, Industrial and Ecological Chemistry

8-16

Authors: Tudor Lupascu, Pavel F. Vlad, Aculina Aricu, Maria Cocu

This communication deals with the appearance and development of the research in the fi eld of chemistry in the Republic of Moldova; at the beginning - in chemistry sections of Moldovan Branch of the USSR Academy of Sciences and then - at the Institute of Chemistry, founded in 1959. The dynamics of changes in the structure and research subjects is traced. Data are presented concerning the research results in the fi eld of the chemistry of coordination compounds, fi ne organic synthesis, natural products chemistry, physicochemical analysis, quantum chemistry, mineral resources, chemistry of natural water and purifi cation of waste water, the preparation and utilization of active carbons, and ecological chemistry. A detailed account both of basic research and applied investigation is given. The collaboration of our scientists with their colleagues from abroad is considered. Information is presented related to the scientifi c schools at our institute, its guidance and laboratory′s leaders. The scientifi c equipment of the institute is mentioned. The relationship of the institute with higher schools, as well as training of young researchers will be presented.

30-35

Authors: Pavel F. Vlad, Fliur Z. Macaev

This overview deals with the advances in the investigation in the fi eld of organic, bioorganic and natural products chemistry as well as the biologically active compounds in the Institute of Chemistry of the Academy of Sciences of Moldova.

44-55

Authors: Tudor Lupascu, Maria Gonta, Viorica Gladchi

This review details the most important achievements in the fi eld of ecological chemistry and environmental protection, obtained at the State University of Moldova and Institute of Chemistry of the Academy of Sciences of Moldova. The main research directions are described, as well as main scientifi c laboratories and centres of these two institutions.

66-71

Authors: Cristina Dinu, Gabriela Vasile, Liliana Cruceru, Jana Petre

The European Drinking Water Directive (98/83/EC), transposed in Romanian Legislation as Low 458/2002, amended by Low 311/2004, imposes the limit of concentration for metallic elements in water intended for human consumption. The toxic metals arsenic and selenium are among these elements and the limit value is 10 μg/L. In the paper there are presented the working conditions for determination of As and Se from drinking water using modern techniques based on the fl ow injection-hydride generation with the inductively coupled plasma atomic emission spectrometry (FIAS-ICP-EOS). The analyses were performed on Optima 5300 DV Perkin Elmer equipment with FIAS 400 Flow Injection System, Perkin Elmer type. For the hydride generation two types of solution were used: 10% (v/v) HCl as a carrier solution and 0.2 % NaBH4 in 0.05%NaOH solution as a reducing agent [1]. The treatment step of the samples and standard solutions consisted in reducing with mixed solutions of KI and ascorbic acid in acidic condition (HCl) for As and only with HCl and high temperature for Se [2,3]. The paper contains the characteristic parameters of the methods, such as: low detection limit, quantifi cation limit, repeatability, precision, recovery, which were evaluated using Certifi ed Reference Materials for each element.

75-78

Authors: Vasile Rusu and Aliona Vrinceanu

Studies of the sorption capacity towards Cu2+ ions of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. Separated clay fraction from diatomic material is clean enough, and especially is rich in montmorillonite. Maximum sorption capacity for studied clay fraction is achieved by rising the temperature of calcination treatment up to 200oC. At higher temperatures the lattice of montmorillonite is contracted and its sorption capacity towards Cu2+ ions decreases strongly.

84-89

Authors: E.N. Kornilova, N.I.Kornilov, O.N Vasiltseva

Mineral waters of Russia, the CIS countries (Ukraine, Belarus, Moldova, Armenia, Azerbaijan, Georgia and Uzbekistan) and EU (Germany, France, Italy, Spain and some East European countries) carried to Chloride- Hydrocarbonate type have been investigated in this work. The analytical dependences connecting, entered by authors, characteristic parameters of structure of waters (

97-102

Authors: Loredana Vacareanu (Stafie), Virgil Barboiu, Daniel Timpu, Mircea Grigoras

A Schiff base macrocycle with persistent rhomboidal shape was synthesized in excellent yield through [2+2] condensation reaction between (R,R)-1,2-diaminocyclohexane and 4,4’-diformyltriphenylamine. The dimeric macrocylic structure was proved by electrospray ionization mass spectrometry (ESI-MS), 1H-NMR, and FTIR spectroscopy. The complexation properties were evidenced by UV absorption.

111-117

Authors: O. I. Gona, N. V. Stolyarchuk, Yu. L. Zub, and N. A. Yaroshenko

Mesoporous silicas with the thiourea functional group ≡Si(CH2)3NHC(S)NHC2H5 have been synthesized by monotemplate and bitemplate route (bitemplate is cetylpyridinium chloride as micelle-forming surfactant and monoethanolamide of saturated n-aliphatic acid as non-micelle-forming surfactant). The infl uence of a number of factors on mesoporous silicas structure has been studied: alkoxysilanes and surfactants concentration, and as well as the nature of medium in hydrothermal treatment of mesophases. The optimum conditions under which functionalized mesoporous silicas have possessing highly ordered hexagonal structure have been found. The surface area of mesoporous silicas synthesized using optimum bitemplate solubilization composition reaches 1055-1350 m2/g and sorption volume and pore diameter are 0.75-0.95 cm3/g and 2.5-2.9 nm respectively.

123-128

Authors: N. N. Gorinchoy, B. Dobrova, M. Yu. Gorbachev, G. Munteanu and I. Ya. Ogurtsov

The present work is devoted to the theoretical study of the activation of the acetylene molecule coordinated in the [Pt(PPh3)2C2H2] complex. By means of DFT calculations it is shown that the geometrical and electronic characteristics of the C2H2 are essentially changed due to its coordination. The subsequent detailed analysis of the molecular orbitals (MO) of the active valence zone of this complex allows one to make important conclusion that this activation is being realized mainly due to the orbital back donation of 5d-electronic density from one of the occupied MOs of the complex [Pt(PPh3)2] to the unoccupied antibonding π*-MO of C2H2.