Chemistry Journal of Moldova

2006 Volume 1, no.1

STUDIES ON THE WATER SOLUBILIZATION PROCESSES OF OENOTANNINS AND THEIR PHYSICO-CHEMICAL PROPERTIES

Author(s):

Gh. Duca, T. Lupaşcu, P. Vlad, V. Kulciţki, R. Nastas


Field: Ecological chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 60-64
Keywords: physico-chemical properties, water solubilization, oenotannins.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2006.01(1).01

Graphical Abstract:
 The results of investigation of oenotannins content in the seeds of different grape varieties are presented in the paper. It was demonstrated that the oenotannins content depends on the grape variety as well as on the geographycal zone of grape cultivation. A new procedure for
 water sollubilization of oenotannins by depolimerization has been elaborated. The mechanism of the oenotannins depolimerization has been reveiled by mass-spectrometric studies. It has been established, that the depolimerization process brings about formation of carboxilic acids and organic peroxides. The presence of the carboxilic and peroxidic groups was detremined on the basis of
 IR spectral analysis. It was demonstrated that the antioxidant properties of modified tannins are higher then those of initial unmodified ones.

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THREE SPIROSTANOL GLYCOSIDES FROM THE SEEDS OF HYOSCYAMUS NIGER L.

Author(s):

Irina Lunga, Pavel Kintia, Stepan Shvets, Carla Bassarelo, Cosimo Pizza and Sonia Piacente


Field: Natural product chemistry and synthesis
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 100-103
Keywords: steroidal glycoside, NMR analysis, Hyoscyamus.
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).02

Graphical Abstract:
 Three steroidal glycosides of spirostane series have been isolated from the seeds of Hyoscyamus niger L.(Solanaceae). Their structures were determined on the basis of chemical evidence and extensive spectroscopic methods including one-dimensional, two-dimensional NMR and MS analysis. In the genus Hyoscyamus the given compounds have been found out for the first time.

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MAGNETIC INVESTIGATION OF AN UNUSUAL DISSYMMETRIC BINUCLEAR MANGANESE CARBOXYLATE COMPLEX

Author(s):

Ghenadie Novitchi, Jean-Pierre Costes, Lilia Popovschi, Sergiu Shova, Aurelian Gulea


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 97-99
Keywords: manganese(II) carboxylates; magnetic properties.
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).03

Graphical Abstract:
 The magnetic susceptibility (χT) of an unusual dissymmetric binuclear manganese corboxylate complex has been measured from 2 to 300K. The magnetic data which have been fitted with help of the Heisenberg Dirac Van Vleck HDVV spin-exchange Hamiltonian H = − J S 1 S 2 , indicate that an antiferromagnetic interaction equal to J = -0.90(1) cm-1 is present. A correlation between J values and Mn-H2O-Mn angles has been tempted.

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[Cr3O(CH3COO)6(H2O)3]NO3⋅HNO3⋅H2O, TRIAQUA-HEXAKIS(μ- ACETATO)-μ3-OXO-TRICHROMIUM(III) NITRATE NITRIC ACID SOLVATE MONOHYDRATE

Author(s):

Marco Bettinelli, Adolfo Speghini, Gabriele Bocelli, Olesea Gherco, Valeriu Mereacre, Denis Prodius, Constantin Turta


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 88-96
Keywords: Chromium carboxylate, Polynuclear complex, UV-Vis.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2006.01(1).04

Graphical Abstract:
 Reaction in methanol solution of the trinuclear ‘basic’ chromium(III) acetate with Pr(NO3)3⋅5H2O and further extraction by chloroform-acetone mixture led to the formation of novel unusual [Cr3O(CH3COO)6(H2O)3]NO3⋅HNO3⋅H2O (1) cluster with one “free” molecule of nitric acid. Complex 1 crystallizes in the monoclinic space group P21/c with, at room temperature, a = 13.624(2), b = 15.032(2), c = 15.180(2) Å, β = 112.98(3) °, Z = 4, and V = 2862.09 Å3. The obtained crystalline compound has been synthesized and characterized by IR and UV/Vis methods.

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SYNTHESIS AND PHYSICO-CHEMICAL STUDIES OF HETEROMETALLIC NITRILOTRIACETATES OF CHROMIUM(III) WITH SOME 3d METALS

Author(s):

Victor Ciornea, Aurelian Gulea


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 84-87
Keywords: heterometallic, nitrilotriacetates, chromium(III), 3d metals, bipyridine.
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).05

Graphical Abstract: 
Heterometallic complexes of chromium (III) with some 3d metals have been synthesized based on nitrilotriacetic acid (H3nta), like M(bpy)2Cr2(OH)2(nta)2·nH2O, where M = Mn2+, Co2+, Ni2+ and Zn2+; bpy = α,α′- bipyridine; n = 8 or 9. Their chemical composition has been determined from the results of the elemental analysis and thermogravimetric study. The coordination modes of the nta3 ̄ ligand and the type of chemical bonds have been proposed basing on IR spectra.

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THE FORECAST AND THE STRATEGY OF CHEMISTRY DEVELOPMENT

Author(s):

Gheorghe Duca, Aurelian Gulea


Field:
Type: Editorial
Issue: 2006 Volume 1, no.1
Pages: 8-14
Keywords:
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).06

Graphical Abstract:
A lasting economy of the state requires continuous progress in technology based on novel scientific achievements. Science and innovation are the basic factors ensuring competitiveness of our industry and agriculture and provide for about 50-85% of economic growth. Science is the nation’s patrimony and it determines the future of the country. The objectives of Science in Moldova are: - to get new knowledge about nature and society; - to create a wide scientific-technologic basis that would ensure: (1) innovation activity in the country; (2) technology progress; (3) world competitiveness of our production.

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ELECTROPHILIC CYCLIZATION OF DITERPENOIDS

Author(s):

Veaceslav Kulciţki, Marina Grinco, Pavel Vlad, Nicon Ungur


Field: Natural product chemistry and synthesis
Type: Review
Issue: 2006 Volume 1, no.1
Pages: 22-35
Keywords: isoprenoids, diterpenoids, electrophilic cyclization, superacids.
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).07

Graphical Abstract:
 A review of diterpenoid cyclization initiated by electrophilic reagents is provided. Conventional protonic and Lewis acids are examined along with superacids as initiators of cyclization cascade. An emphasis is placed on the use of cyclization reactions as a tool for the synthesis of compounds with potential practical utility. The review contains 74 references.

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ASSESSMENT OF KINETIC PARAMETERS IN THE WATERS OF THE NISTRU COURSE IN THE SECTION NASLAVCEA – DUBASARI

Author(s):

Elena Bunduchi, Gheorghe Duca, Viorica Gladchi, Nelli Goreaceva, Igor Mardari


Field: Ecological chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 56-59
Keywords: kinetic indicators, hydrogen peroxide, redox state, free radicals, inhibition capacity.
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DOI:
dx.doi.org/10.19261/cjm.2006.01(1).08

Graphical Abstract:
 The current work represents the results of a monitoring executed on Nistru River waters between October 2003 and September 2005. The water quality was evaluated on the basis of such kinetic indicators as redox state and capacity of inhibition. The obtained results shows that Nistru River water in the segment Naslavcea village – Dubasari barrage are continuously polluted with reducing substances that diminish the H2O2 content, that actually determines the redox state of natural waters and the content of free radicals.

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THE SYNTHESIS AND STUDY OF TETRANUCLEAR CLUSTER [Fe4O2(CCl3COO)8(THF)2(DMF)(H2O)]⋅THF

Author(s):

Denis Prodius, Valeriu Mereacre, Sergiu Shova, Maria Gdaniec, Yurii Simonov, Lorenzo Sorace, Andrea Caneschi, Nicolae Stanica, Ion Geru, Constantin Turta


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 77-83
Keywords: {Fe4O2} core; Homotetranuclear carboxylate; Crystal structure; Antiferromagnetic exchange.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2006.01(1).09

Graphical Abstract:
 The novel bis(μ3-oxo) tetranuclear trichloracetate cluster, [Fe4O2(CCl3COO)8(THF)2(DMF)(H2O)]⋅THF (1), has been synthesised and subsequently characterised by X-ray structure analysis, magnetic measurements and infra red (IR). The structure of cluster is “butterfly” type. The Fe···Fe separation has the value of 2.883(1) - 3.441(7) Å. The coordination number of iron (III) is 6. Magnetic studies reveal the presence of an antiferromagnetic exchange in the parallelogram skeletons of the tetranuclear species. Using the spin Hamiltonian H = -2Jwb(Ŝ1Ŝ2 + Ŝ2Ŝ3 + Ŝ3Ŝ4 + Ŝ4Ŝ1) - 2JbbŜ2Ŝ4v+ gμβ(Ŝ1z + Ŝ2z +Ŝ3z + Ŝ4z)B, the fitting parameters Jbb = - 14.3 cm-1, Jwb = - 32.1 cm-1 , g = 2.07, ρparam. -5 impur. = 4.2 %, ΘCurie-Weiss const. = -0.5 K and R = 6.8·10 were obtained.

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WHAT CAN BE DONE WITH THE ACETYL GROUP OF ARYL-1-ETHANONES?

Author(s):

Fliur Macaev


Field: Organic chemistry
Type: Review
Issue: 2006 Volume 1, no.1
Pages: 36-49
Keywords: organic synthesis, aryl-1-ethanones, acetyl group.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2006.01(1).10

Graphical Abstract:
 Literature data on utilization of acetyl group of aryl-1-ethanones (acetophenones) for the synthesis of organic compounds is generalized. Different approaches of preparation of aromatic compounds by chemical transformations of methyl as well as keto- group of titled compounds are systematized. Examples of the synthesis of organic compounds based on products of primary transformations of aryl-1-ethanones are considered.

Downloads: 10