Chemistry Journal of Moldova

DOI: dx.doi.org/10.19261/cjm.2015.10(2).08

Graphical Abstract:  The reaction of (+)-D-glucose with 4-chloroaniline or 3,5-dibromoaniline leads almost exclusively to the β-configuration of glucosylated anilines. The acetylating of 2-(3,5-dibromophenylamino)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol is less selective than in case of the 2-(4-chlorophenylamino)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol.

DOI: dx.doi.org/10.19261/cjm.2015.10(2).09

Graphical Abstract:  Tyramine sulfamate was linked to the trityl chloride resin and this polymeric support used to introduce two levels of molecular diversity by formation of peptide bonds. A dual cleavage strategy next generated in a sequential way (without resin split) two types of compounds (phenol and arylsulfamate derivatives), which are therapeutically attractive types of compounds.

DOI: dx.doi.org/10.19261/cjm.2015.10(2).10

Graphical Abstract:  Oxaziridine [c-CH3NO (X1A)], c-CH2NO (X2A) radicals and Cl, NH2 and methyl derivatives of oxaziridine structures have been optimized via DFTB3LYP level of theory using 6-311++G (d, p) basis set. Population analysis had been carried out. Vertical ionization energy (VIE) and adiabatic ionization energy (AIE), Fukui indices and some quantum chemical parameters were calculated. N-O bond was determined as weakest bond in oxaziridine triangle. The effect of electron withdrawing and electron donating groups on stability of weakest bond were assessed.

DOI: dx.doi.org/10.19261/cjm.2008.03(1).01

Graphical Abstract: This research paper presents the results of the investigation of antioxidant activities of various inhibitors, which are constituents of winery products: quercitin, rezveratrol, dihydroxyfumaric acid. Also, the antioxidant activity of tartaric and dihydroxyfumaric (DFH₄) acids derivatives has been determined: sodium dihydroxyfumarate, dimethylic ester of DFH₄ and dimethylic ester of tartaric acid. The enotannin extracts obtained from grape seeds have been evaluated: the non-oxidized enotannin extract Eneox and the oxidized one -Enoxil.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).02

Graphical Abstract:  This paper dwells upon the influence of sodium ions on experimental results regarding the concentration of strontium ions in waters with a high content of sodium ions by emission flame photometry and atomic absorption spectroscopy. The metrological characteristics of both methods are evaluated.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).03

Graphical Abstract:  The following factors which can improve the process of coagulation were studied: (i) the influence of stirring speed during coagulation and (ii) the influence of the concentration of the coagulant solution added in the process of coagulation. The coagulation process was studied on raw water of the Prut River. Application of the recommended procedure contribute to the reduction of the coagulant dose, the contact time, the aluminum concentration in water and the expenses for water treatment.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).04

Graphical Abstract:  In young wines potassium hydrogen tartrate is always present in supersaturating concentration and crystallizes spontaneously. The aim of this study is to obtain kinetic parameters, which explain the stability of young wines during the stabilization treatments. The kinetic and equilibrium parameters were evaluated and discussed. According to the obtained experimental results, the optimal regime for production and stabilization of young wines has been established.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).05

Graphical Abstract:  The present work was undertaken to study the effect of the treatment temperature on the potassium bitartrate stability and composition of young wines. The thermodynamic parameters, namely ∆G°, ∆H°, ∆S° were calculated to predict the nature of potassium hydrogen tartrate (KHT) precipitation. According to the achieved results, the exothermal nature and thermodynamical feasibility of KHT precipitation in young wines were established. Based on thermodynamics, negative ∆G°, ∆H° values and positive ∆S° value give a spontaneous KHT process at lower temperatures.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).06

Graphical Abstract:  Hematite nanoparticles were prepared by a procedure consisting in sonication of μ3-oxo trinuclear iron(III) acetate of composition [Fe3O(OOCCH3)6(H2O)3]NO3∙4H2O, {Fe3O}NO3, as iron source, in strong basic conditions followed by thermal treatment at 600˚C. The formation of the hematite was confirmed by IR spectroscopy, X-ray powder diffraction and Raman spectroscopy while the shape and size of the nanoparticles and their agglomeration were evidenced and estimated on the basis of the images taken with TEM technique.

DOI: dx.doi.org/10.19261/cjm.2015.10(1).07

Graphical Abstract:  A lanthanum(III) cyanoacetate complex  {[La2(CNCH2COO)6 (H2O)4]∙H2O}n (1) was synthesized and characterized by X-ray single-crystal analysis. The complex 1 exhibits one-dimensional coordination polymer structure. Cyanoacetate ligands coordinated in the bidentate bridging and tridentate-chelating bridging modes. The cyano-group of ligand is not coordinated to the lanthanide ion.