Chemistry Journal of Moldova

2016 Volume 11, no.1

THE NATURE OF THE Co-C BOND CLEAVAGE PROCESSES IN METHYLCOB(II)ALAMIN AND ADENOSYLCOB(III)ALAMIN

Author(s):

Tudor Spataru, Francisco Fernandez


Field: Physical chemistry and chemical physics
Type: Review
Issue: 2016 Volume 11, no.1
Pages: 10-20
Keywords: vitamin B12, mechanism, bio-catalysis, Pseudo-Jahn-Teller effect, DFT, MCSCF.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).01

Graphical Abstract:
 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.


 

Downloads: 133

ECOLOGICAL POTENTIAL OF SURFACE WATERS IN NATURAL SCIENTIFIC RESERVE “LOWER PRUT”

Author(s):

Maria Sandu, Anatol Tarita, Raisa Lozan, Natalia Zgircu, Elena Mosanu, Tatiana Goreacioc, Alexandru Zlotea, Anna Comarnitchi, Iulia Sidoren, Sergiu Turcan, Adrian Tarita


Field: Ecological chemistry
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 21-26
Keywords: Lake Beleu, self-purification capacity, nitrification process, BOD5 , COD-Cr.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).02

Graphical Abstract: 
The research results have marked a low value of the self-purification capacity for Beleu Lake water, between 0.12 and 0.19, which is of 1.2-2 times smaller than the one from Prut River (0.25), correlating positively with the values of BOD5, COD-Cr and the time of biochemical oxidation of ammonium ions. The evolution of stage NH4+(NH3) → NO2- in the process of nitrification in lake water in November 2014 takes place about 25 days and the process NO2- → NO3- is more than 35 days, the duration about 2 times higher than in lake water stages from 2015 and 2.8-3.0 times higher than that of the model with water from Prut River.

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EFFECT OF ALUMINIUM SULPHATE AGING ON COAGULATION PROCESS FOR THE PRUT RIVER WATER TREATMENT

Author(s):

Larisa Postolachi, Vasile Rusu, Tudor Lupascu


Field: Industrial chemistry
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 27-32
Keywords: coagulation, Jar-test, aluminium sulphate, aging.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).03

Graphical Abstract: 
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. 


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THE FORMATION MECHANISM OF ASSEMBLED COMPLEXES BRIDGED BY1,3–BIS(4–PYRIDYL)PROPANE

Author(s):

Haruka Dote, Hiroki Yasuhara, Satoru Nakashima


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 33-38
Keywords: mixed crystal, assembled complex, 1,3-bis(4-pyridyl)propane, crystal formation.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).04

Graphical Abstract: 
Several types of crystals having different color appeared in the synthesis of assembled complex of mixed crystals with three metals. [H2(bpp)][M(NCS)4] changed to 1D chain polymer (M(NCS)2(bpp)) by releasing HNCS from the cation and anion in a reaction vessel.


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STRUCTURE AND SOME BIOLOGICAL PROPERTIES OF Fe(III) COMPLEXES WITH NITROGEN-CONTAINING LIGANDS

Author(s):

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


Field: Inorganic and coordination chemistry
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 39-49
Keywords: iron complexes, nitrogen-containing ligands, structure, biological properties.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).05

Graphical Abstract:
 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.


Downloads: 51

SYNTHESIS OF NEW DRIMANE AND HOMODRIMANE LACTAMS BY BECKMANN REARRANGEMENT OF SOME KETOXIMES

Author(s):

Elena Secara


Field: Natural product chemistry and synthesis
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 50-54
Keywords: drimane, homodrimane, lactam, ketoxime, synthesis, Beckmann rearrangement.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).06

Graphical Abstract:
 Synthesis of new drimane and homodrimane lactams, derivatives of octahydro-1H-benzo[d]azepine and octahydro-1H-benzo[c]azepine, from norambreinolide is reported. These compounds were prepared by Beckmann rearrangement of the corresponding ketooximes.



 

Downloads: 34

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SYMMETRICAL DIQUATERNARY AMMONIUM SALTS BEARING BIS-1,3,4-OXADIAZOLE RINGS MOIETIES

Author(s):

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


Field: Organic chemistry
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 55-60
Keywords: 1,3,4-oxadiazole, quaternary ammonium compounds, DMAEMA, DEAEMA, antimicrobial activities.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).07

Graphical Abstract:
 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.


 

Downloads: 47

STUDIES OF THE SUBSTITUTION EFFECTS ON THE ELECTRONIC PROPERTIES FOR BIPHENYL AND DERIVATIVE MOLECULES BY USING DFT METHOD

Author(s):

Rajaa Khedir Al-Yasari


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 61-68
Keywords: DFT calculation, electronic properties, IR and NMR spectra, biphenyl molecule.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).08

Graphical Abstract: 
DFT method has been carried out to study the substitution effects of NO2 group on the electronic (ionization potential, electron affinity, electronegativity, hardness, softness and electrophilicity index) and IR spectral properties of biphenyl and derivative molecules by using the B3LYP functional and the 3-21G basis set, as well as the optimization structure. The calculated values of HOMO and LUMO energies, as well as predicted by ChemBioDraw program 1H and 13C NMR spectra for the studied compounds are in a good agreement with experimental data.


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ELECTRON MICROSCOPY OF ANIONIC SURFACTANT-DIRECTED SYNTHESIS OF MAGNETITE NANOPARTICLES

Author(s):

Sharali Malik, Ian James Hewitt, Annie Katherine Powell


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 69-73
Keywords: magnetite, magnetic nanoparticles, hydrothermal synthesis, drug delivery.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).09

Graphical Abstract:
 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.


Downloads: 32

DFT (B3LYP) COMPUTATIONAL STUDY ON THE MECHANISMS OF FORMATION OF SOME SEMICARBAZONES

Author(s):

Abdulfatai Siaka, Adamu Uzairu, Sulaiman Idris, Hamza Abba


Field: Physical chemistry and chemical physics
Type: Research paper
Issue: 2016 Volume 11, no.1
Pages: 74-85
Keywords: semicarbazone, kinetics, bi- and unimolecular step, transition step, spontaneity.
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Abstract (PDF)

DOI:
dx.doi.org/10.19261/cjm.2016.11(1).10

Graphical Abstract:
 Thermodynamic and kinetic mechanisms of forming six semicarbazones have been investigated computationally by DFT B3LYP method. All the reactions proceed via two transitions and include two consecutive steps: bimolecular and unimolecular. The computed transition steps have varying equilibrium constants values, enthalpy of activation and Gibbs energy of activation, depending on the semicarbazone involved.


 

Downloads: 41