Chemistry Journal of Moldova

Accepted papers

Vladyslav Zhezherya, Petro Linnik, Rostyslav Linnik

Field: Ecological chemistry
Type: Research paper
13
water body, humic substance, metal, binding ability, molecular weight distribution
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http://doi.org/10.19261/cjm.2023.1091

Supplementary Material (PDF)

Graphical Abstract: The aim of this research work was to evaluate the role of different fractions of humic substances in the binding of Al(III), Fe(III) and Cu(II) ions into complexes. The share of humic substances with a molecular weight of 20–5 kDa increases from 37% to 59%, when the total concentration of humic substances also increases. It was established that humic substances with molecular weight 20–5 kDa bounded the smallest amount of Al(III), Fe(III) and Cu(II) into complexes.



Downloads: 3

Tudor Spataru

Field: Physical chemistry and chemical physics
Type: Research paper
9
glutamate mutase, methylmalonyl-CoA mutase, adenosylcobalamin cofactor, vitamin B12, Pseudo-Jahn-Teller effect.
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http://doi.org/10.19261/cjm.2023.1087

Graphical Abstract: The Pseudo-Jahn-Teller-Effect governs the glutamate mutase and methylmalonate-CoA mutase preliminary step and provides insight into particular details of in vivo C-N bond cleavage reactions of the adenosylcobalamin cofactor. Multi-configurational self-consistent field (MCSCF) calculations show that the preliminary step reaction glutamate mutase and methylmalonate-CoA mutase processes occur in the absence of total energy barriers.




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Muslim Hasan Allawi, Riyadh Sadeq ALMukhtar, Shurooq Talib Al-Humairi, Ali Dawood Salman, Tatjána Juzsakova, Viktor Sebestyén, Igor Cretescu

Field: Ecological chemistry
Type: Research paper
7
ultrasound, diisopropyl methylphosphonate, sonochemical kinetic, aqueous solution, chemical oxidant.
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doi.org/10.19261/cjm.2023.1019

Graphical Abstract: The degradation of diisopropyl methylphosphonate (DIMP) in aqueous solutions was studied using ultrasound irradiation with a fixed frequency of 26.6 kHz, following the first-order kinetic model. The experimental parameters, including the pH, the initial concentration of DIMP, the processing time, and the concentration of the additive CCl4 were investigated. The best degradation efficiency of 98% was observed at pH of 10, adding 0.8 g/L CCl4 for a processing time of 45 min.




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Pavlo Kuzema, Iryna Laguta, Oksana Stavinskaya, Viktor Anishchenko, Anastasiia Kramar, Natalia Smirnova, Tetiana Fesenko, Roman Ivannikov, Oksana Linnik

Field: Ecological chemistry
Type: Research paper
10
plant extract, phenolic compound, antioxidant, biodiesel, oxidation stability.
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Graphical Abstract: The extracts from the leaves of Deschampsia antarctica, Camelina sativa, and Camellia japonica plants, as well as from Camelina sativa and Silybum marianum seedcakes were investigated as potential additives for improvement of biodiesel stability against oxidation. In spite of significant distinctions in the content of various phenolic compounds, all the extracts were found to effectively inhibit DPPH radicals and decelerate transformation of fatty acid esters of biodiesel into organic acids by ~9-26%. Various extracts were shown to have different activity towards the biodiesel from rape and camelina seed oils; this result is consistent with the assumption that there is no universal stabilizer for different types of biodiesel.



Downloads: 20

Olga Chudinovych

Field: Physical chemistry and chemical physics
Type: Research paper
9
phase equilibria, lanthana, lutetia, erbia, lattice parameter.
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Graphical Abstract: The isothermal section of the La2O3–Lu2O3–Er2O3 phase diagram at 1250°C has the characteristic three one-phase fields (A-La2O3, R, C-Lu2O3(Er2O3)) corresponding to solid solutions based on starting components and two two-phase fields (C + R, A + R) between them. 
 


Downloads: 10

Pedro Silva

Field: Physical chemistry and chemical physics
Type: Research paper
9
density-functional theory, reaction mechanisms, intra-molecular Williamson’s ether synthesis, epoxide, halohydrin.
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Graphical Abstract: DFT computations identify the effects that enable the synthesis of geometrically-strained epoxide from deprotonated halohydrins. These computations also explain the preference for the formation of larger cyclic ethers with five-atom rings over six-atom-rings. Increased temperature favors elimination over SN2 only when the reacting moieties are part of separate molecules.



Downloads: 8

Natalia Talmaci, Diana Dragancea, Elena Gorincioi, Pavlina Bourosh, Victor Kravtsov

Field: Inorganic and coordination chemistry
Type: Research paper
8
carbohydrazide, o-vanillin, syn-anti isomer, X-ray diffraction, NMR spectroscopy.
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https://doi.org/10.19261/cjm.2023.1074

Supplementary Material (PDF) 
Graphical Abstract:
The crystal structure of 1,5-bis(2-hydroxy-3-methoxybenzylidene) carbonohydrazide (1) was determined by X-ray single crystal diffraction study. In solid-state the molecule adopts the anti keto conformation, while NMR studies proved evidence on the presence of its syn tautomer in DMSO solution. 


 


Downloads: 13

Inna Trus, Vita Halysh, Mariia Tverdokhlib, Mukola Gomelya

Field: Industrial chemistry
Type: Research paper
8
mine water, softening, aluminum coagulant, sulphate, hardness ion.
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Graphical Abstract: In this paper the process of reagent desalination of mineralized mine waters was studied. Reagents 5/6 aluminum hydroxochloride and sodium aluminate were used during liming. Complex processing of waste generated during reagent water treatment allows to create a low-waste technology for the purification of mineralized water. 




Downloads: 15

Isaac Bersuker

Field: Physical chemistry and chemical physics
Type: Invited paper
8
adiabatic potential, electronic degeneracy, Jahn-Teller effect, pseudo Jahn-Teller effect, spontaneous symmetry breaking.
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Graphical Abstract: This paper discusses the notion of symmetry of polyatomic systems defined as invariance under transformations, and showes that this important property of atomic matter is extremely vulnerable, and may undergo internal breakdown, subject to the presence of electronic degeneracy or pseudodegeneracy. It is shown that electronic degeneracy and its extended form, called pseudodegeneracy, are actually the only source of spontaneous symmetry breaking (SSB) in nature, including all forms of matter, beginning with elementary particles, via nuclei, atoms, molecules, and solids. Theoretically, the vulnerability of the notion of symmetry is due to the fact that, following quantum mechanics, the separation of the motion of electrons and nuclei (and, similarly, the separation of motions of elementary particles) is approximate, and hence the classical notion of polyatomic space configuration is approximate too, with SSB as one of its main violation.


 

Downloads: 5