Chemistry Journal of Moldova

DOI: dx.doi.org/10.19261/cjm.2007.02(1).01


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).02


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).03

Graphical Abstract: Room temperature ionic liquids (ILs) have been recognized as a new generation of solvents for “green chemistry” and represent remarkably promising classes of technologically useful and fundamentally interesting materials [1-6]. Most of them are

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DOI: dx.doi.org/10.19261/cjm.2007.02(1).04

Graphical Abstract: A mixture of 7α- and 17-bromonorambreinolides was obtained on treatment of the mixture of isomeric methyl bicyclohomofarnesenoates, the norambreinolide transesterification product, with NBS and H2O2. The structure of 7α- and 17-bromonorambreinolides was elucidated on the basis of spectral data. The structure of 17-bromonorambreinolide was confirmed by its reduction with LiAlH4 into sclaradiol, and that of 7α-bromonorambreinolide by X-ray analysis.


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).05

Graphical Abstract: Phytochemical analysis of the seeds of Hyocyamus niger L. (Solonaceae) resulted in the isolation of six steroidal glycosides, two furostanol (1, 2) and four spirostanol saponins (3, 4, 5, 6), which were found in this plant for the first time. The structures of these compounds were determined by detailed analysis of their spectral data, including two-dimensional NMR spectroscopy and MS spectroscopy. The antifungal activity of a crude steroidal glycoside extract, fractions of spirostanoles and individual glicosides was investigated in vitro against a panel of human pathogenic fungi, yeasts as well as dermatophytes and filamentous species.

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DOI: dx.doi.org/10.19261/cjm.2007.02(1).06

Graphical Abstract: Thiolato-bridged complex [Cu^I₄Cu^II₄(peampt)₄Cl₈]·2H₂O (Hpeampt = 1-(2-pyridylethyl)amino) methylpropane-2-thiol) has been synthesized and characterized by the elemental analysis, IR and UV-vis spectroscopies and magnetic susceptibility measurement. The X-ray crystal structure analysis of this complex shows a localized mixed-valence octanuclear cage structure made up of four trigonal-bipyramidal Cu^IIN₂SCl₂, two trigonal CuIS2Cl, and two tetrahedral Cu^IS₂Cl₂ coordination sites. Temperature dependence of magnetic susceptibility (4.5— 300 K) shows that a fairly strong antiferromagnetic interaction is operating between the four Cu^II ions.


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).07

Graphical Abstract: The solid-state structure of the tri-potassium calix[4]arene dihydroxyphosphonate salt is presented. In this structure, two potassium cations bridge between layers of dimeric calixarene diphosphonate units and two other potassium cations bridge along the face of the layers. The ubiquitous dimeric association of the calixarenes shows the highest interdigitation value so far observed. As expected, the cations are solvated and are complexed exo with respect to calixarene crown. The octahedral coordination sphere of the potassium cations is formed by two phosphonate groups of the calixarenes and four water molecules. Electrostatic forces represent the major element of interaction in the solid-state system.


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).08

Graphical Abstract: The interaction of cis-Re₂(RCOO)₂Cl₄, trans-Re₂(RCOO)₂Cl₄, Re₂(RCOO)₃Cl₃ and Re₂(RCOO)₄Cl₂ (where R - alkyl group) with 1,3,5-triphenylverdazyle radical in 1,2-dichlorethane was investigated. It is discovered, that gradual substitution of halogenide ligands by carboxylates in dirhenium(III) clusters led to slowing down of reaction with a radical due to different influence of these ligands on parameters of rhenium - rhenium bond. Presented data showed perspectivity of Re₂⁶⁺-substances applications as therapeutic agents due to their low toxicity and antiradical properties that occured by δ-component of quadruple Re-Re bond electron transition.


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).09

Graphical Abstract: Interactions of a series of indole-3-alkanoic acids (with n-alkanoic acid side-chains from C1 to C4) with iron(III) in acidic aqueous solutions have been shown to comprise two parallel processes including complexation and redox transformations giving iron(II) hexaaquo complexes. The structure and composition of the reaction products are discussed, as analysed using a combination of instrumental techniques including 57Fe Mössbauer, vibrational and HNMR spectroscopies.


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DOI: dx.doi.org/10.19261/cjm.2007.02(1).10

Graphical Abstract: Four new heteronuclear lanthanide complexes with general formula [Ge(OH)(μ-HDTPA)LnGe(OH) (μ-DTPA)] (Ln = Sm – Dy) were synthesized and subsequently characterized by different physico- chemical methods. The structures of new compounds have been proposed. In considered complexes the 4f-luminescence of three-charged ions of samarium, europium, terbium and dysprosium is realized at UV-excitation. It is noteworthy that it is the first observation of 4f-luminescence in water solutions of heteronuclear f-p-complexes. The comparison of luminescent characteristics of hetero- and homonuclear landthanide complexes is described and discussed as well.

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