Chemistry Journal of Moldova最新文献

Spontaneous symmetry breaking as a law of nature 自发对称破缺是一种自然规律

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1098

Isaac Bersuker

{"title":"Spontaneous symmetry breaking as a law of nature","authors":"Isaac Bersuker","doi":"10.19261/cjm.2023.1098","DOIUrl":"https://doi.org/10.19261/cjm.2023.1098","url":null,"abstract":"In a semi-review paper, it was discussed the notion of symmetry of polyatomic systems defined as invariance under transformations, and show that this important property of atomic matter is extremely vulnerable, and may undergo internal breakdown, subject to the presence of electronic degeneracy or pseudodegeneracy. First formulated by Landau, L. in 1934, later proved and published by Jahn and Teller, this Jahn-Teller effect (JTE) underwent tremendous developments with important applications in physics, chemistry, biology, and materials science. Less attention was paid to the roots of this phenomenon and its correct interpretation in the sense of its influence on observable properties. 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.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139188061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Degradation of diisopropyl methylphosphonate in aqueous solutions by ultrasonic irradiation combined with oxidation process 超声波辐照结合氧化过程降解水溶液中的甲基膦酸二异丙酯

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1019

Muslim Hasan Allawi, Riyadh Almukhtar, S. Al-Humairi, A. D. Salman, Tatjana Juzsakova, Vitkor Sebestyén, Igor Cretescu

引用次数: 0

On the calculation of lanthanide systems. The spectral parameters of praseodymium trivalent ion 关于镧系元素的计算。三价镨离子的光谱参数

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1146

A. Toader, M. C. Buta, F. Cimpoesu

引用次数: 0

Selectivity, synthesis, crystal structure and biological activity of the anion-coordination phenanthrolinium tartratogermanate 阴离子配位菲罗啉酒石酸盐的选择性、合成、晶体结构和生物活性

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1121

E. Afanasenko, I. Seifullina, E.V. Martsinko, V. Dyakonenko, S. Shishkina

{"title":"Selectivity, synthesis, crystal structure and biological activity of the anion-coordination phenanthrolinium tartratogermanate","authors":"E. Afanasenko, I. Seifullina, E.V. Martsinko, V. Dyakonenko, S. Shishkina","doi":"10.19261/cjm.2023.1121","DOIUrl":"https://doi.org/10.19261/cjm.2023.1121","url":null,"abstract":"Novel supramolecular cation-anionic coordination compound (HPhen)4[(μ-O){Ge2(OH) (μ-Tart)2}2]·9H2O was synthesised and characterised by the X-ray, elemental, IR- and Hirshfeld surface analysis. It was established that original synthesis method and ability of 1,10-phenanthroline to be protonated promotes the formation of [(μ-O){Ge2(OH)(μ-Tart)2}2]4- anion. In this anion, dimeric fragments are connected by a bridging oxygen atom, and the coordination polyhedra around the germanium atoms adopt a distorted trigonal bipyramidal geometry. The cations HPhen+ serve as effective building blocks, strengthening the overall structure through classical hydrogen bonding and additional π-π stacking interactions. Biological screening of (HPhen)4[(μ-O){Ge2(OH) (μ-Tart)2}2]·9H2O demonstrated its remarkable enzyme-effector and antimicrobial activity. The compounds' efficacy can be attributed to the synergistic effects of the independent cations and anions, as well as the ability of protonated 1,10-phenanthroline to inhibit metal ions in enzymes and form stacking interactions with specific protein components. These characteristics make such compounds highly effective and promising antibacterial agents that minimize the risk of developing bacterial resistance.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139192934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The role of various fractions of humic substances from surface water in binding Al(III), Fe(III), AND Cu(II) into complexes 地表水中各种腐殖质成分在将 Al(III)、Fe(III) 和 Cu(II) 结合成络合物中的作用

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1091

V. Zhezherya, Peter Linnik, R. Linnik

{"title":"The role of various fractions of humic substances from surface water in binding Al(III), Fe(III), AND Cu(II) into complexes","authors":"V. Zhezherya, Peter Linnik, R. Linnik","doi":"10.19261/cjm.2023.1091","DOIUrl":"https://doi.org/10.19261/cjm.2023.1091","url":null,"abstract":"The aim of this research work was to evaluate the role of various fractions of humic substances (HS) in binding Al(III), Fe(III) and Cu(II) ions into complexes using gel chromatography. With an increase in HS concentration in Ukraine’s surface water bodies, the share of HS’ fraction with a molecular weight of 20–5 kDa increases from 37% to 59%. In the water bodies under study the HS’ fractions with molecular weight 20–5 kDa and < 1 kDa play a principal role in the studied metals’ migration. HS with molecular weight 20–5 kDa have been found to bind the smallest amount of Al(III), Fe(III) and Cu(II) in complexes, if the metals concentration bound by 1 mg fraction of HS with a certain molecular weight is calculated. Experimental results showed that, the investigated metal ions have the ability to bind into complexes mainly by HS with a molecular weight of >20 and <1 kDa. In the water bodies under study 1 mg of humic acids has a greater binding ability in relation to Al(III), Fe(III) and Cu(II) ions than 1 mg of fulvic acids. Fulvic acids and humic acids with a molecular weight of 20–5 kDa also have the lowest binding ability.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139190852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Antioxidant properties of some plant extracts and effect of their addition on the oxidation stability of biodiesel 一些植物提取物的抗氧化特性及其添加量对生物柴油氧化稳定性的影响

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1100

P. Kuzema, Iryna Laguta, O. Stavinskaya, Viktor Anishchenko, Anastasiia Kramar, Nataliia Smirnova, T. Fesenko, Roman Ivannikov, O. Linnik

{"title":"Antioxidant properties of some plant extracts and effect of their addition on the oxidation stability of biodiesel","authors":"P. Kuzema, Iryna Laguta, O. Stavinskaya, Viktor Anishchenko, Anastasiia Kramar, Nataliia Smirnova, T. Fesenko, Roman Ivannikov, O. Linnik","doi":"10.19261/cjm.2023.1100","DOIUrl":"https://doi.org/10.19261/cjm.2023.1100","url":null,"abstract":"The extracts from the leaves of Deschampsia antarctica É. Desv., Camelina sativa (L.) Crantz, and Camellia japonica L. plants, as well as from defatted Camelina sativa and Silybum marianum seedcakes were investigated as potential additives for improvement of biodiesel stability against oxidation. Composition of the extracts was studied by means of HPLC, and antioxidant properties were evaluated using the Folin-Ciocalteu assay and the DPPH test. The oxidation of biodiesel was monitored during the accelerated procedure at 43C, with the changes in the acid number of biodiesel samples being the criteria of this process. In spite of significant distinctions in the content of various phenolic compounds, all the extracts were found to possess high antioxidant activity and decelerate biodiesel oxidation by 9-26%. The data did not reveal a directly proportional relationship between the antioxidants content in the extract, on the one hand, and the enhancement in biodiesel stability, on the other hand; various extracts had different influence on the behaviour of biodiesel from rape and Camelina seed oils. The results obtained are consistent with the assumption that there is no universal stabilizer for different types of biodiesel and indicate the prospects on searching for novel antioxidants of natural origin to inhibit oxidative processes.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139190225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Crystal structure and NMR spectroscopic characterization of 1,5-bis(2-hydroxy-3-methoxybenzylidene)carbonohydrazide 1,5-双(2-羟基-3-甲氧基亚苄基)碳酰肼的晶体结构和核磁共振光谱表征

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1074

Natalia Talmaci, D. Dragancea, Elena Gorincioi, P. Bourosh, V. Kravtsov

引用次数: 0

Computational insights into the spontaneity of epoxide formation from halohydrins and other mechanistic details of Williamson’s ether synthesis 通过计算深入了解卤水酐形成环氧化物的自发性以及威廉姆森醚合成法的其他机理细节

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1083

Pedro J. Silva

{"title":"Computational insights into the spontaneity of epoxide formation from halohydrins and other mechanistic details of Williamson’s ether synthesis","authors":"Pedro J. Silva","doi":"10.19261/cjm.2023.1083","DOIUrl":"https://doi.org/10.19261/cjm.2023.1083","url":null,"abstract":"The reaction mechanism of several Williamson‟s ether syntheses have been studied using density functional theory with triple-ζ basis sets. These computations show that the synthesis of geometrically-strained epoxide from deprotonated halohydrins is due to the combined effects of favourable solvation of the products, higher bond enthalpy of C-O bonds vs. C-Cl bonds and increased vibrational entropy of the epoxide vs. the original halohydrin. Examination of the pathways leading to the formation of larger cyclic ethers revealed that the experimentally-observed preference for the formation of five-atom rings over six-atom-rings is due to the preference of the intervening methylene groups for staggered conformations, which entails that the alkyl carbon in the reactant state leading to the six-atom cyclic ether is initially not properly aligned with the attacking alkoxide. Study of the competing elimination reactions further shows that during the synthesis of five-atom cyclic ethers the competing elimination reaction is strongly disfavoured due to steric effects. The temperature dependence of both reactions favours elimination over SN2 as temperature rises, though only when the alkoxide and the halogen moieties are not part of the same carbon chain.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139193967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low waste technology for mine waters treatment using lime and aluminum coagulants 使用石灰和铝混凝剂处理矿井水的低废物技术

IF 0.5

Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1063

I. Trus, V. Halysh, M. Tverdokhlib, M. Gomelya

引用次数: 0

The Co-N bond cleavage in the adenosyncobalamin cofactor in advance to glutamate mutase and methylmalonyl-CoA mutase processes 腺苷钴胺辅助因子中的 Co-N 键裂解提前到谷氨酸变异酶和甲基丙二酰-CoA 变异酶过程中

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Chemistry Journal of Moldova Pub Date : 2023-12-01 DOI: 10.19261/cjm.2023.1087

Tudor Spataru

{"title":"The Co-N bond cleavage in the adenosyncobalamin cofactor in advance to glutamate mutase and methylmalonyl-CoA mutase processes","authors":"Tudor Spataru","doi":"10.19261/cjm.2023.1087","DOIUrl":"https://doi.org/10.19261/cjm.2023.1087","url":null,"abstract":"The in vivo experiments show that the adenosylcobalamin cofactor in glutamate mutase and methylmalonyl-CoA mutase processes lose its dimethylbenzimidazole axial ligand before starting the enzymatic processes. Complete active space self-consistent field geometry optimization of the vitamin B12 active forms plus substrates joint models have been performed. These joint models include the adenosylcobalamin cofactor, the carboxyl negative ion model of the studied processes’ active substrates, and the histidine molecule. Partial electronic density is transferred from the highest occupied substrate molecular orbitals to the lowest unoccupied antibonding molecular orbitals, which consist of corrin ring and dimethylbenzimidazole ligand common molecular orbitals during the multi-configurational self-consistent field molecular orbital mixing process. As a result, the Co-N axial bond is permanently elongated during the complete active space self-consistent field geometry optimization until its complete rupture and until the removal of the dimethylbenzimidazole ligand from the central cobalt atom and the corrin ring is complete. The Co-N bond cleavage in the adenosylcobalamin cofactors in the studied processes is running as no energy barrier process under the influence of their active substrates and histidine molecule.","PeriodicalId":9922,"journal":{"name":"Chemistry Journal of Moldova","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139191311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0