https://lmaleidykla.lt/ojs/index.php/chemija/issue/feed Chemija 2025-07-02T08:14:40+03:00 Executive Secretary vilniuschemija@lma.lt Open Journal Systems <p><em>Chemija</em> publishes original research articles and reviews from all branches of modern chemistry, including physical, inorganic, analytical, organic, polymer chemistry, electrochemistry, and multidisciplinary approaches. The journal is covered by <em>Clarivate Web of Science</em> since 2007. 2023 impact factor 0.5, 5-year impact factor 0.6.</p> https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6405 Title 2025-07-01T05:44:05+03:00 Lietuvos mokslų akademija ojs@lmaleidyba.lt 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6406 Contents 2025-07-01T05:45:54+03:00 Lietuvos mokslų akademija ojs@lmaleidyba.lt 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6397 Structural analysis of 1-chlorosilacyclopentane by means of vibrational spectroscopy 2025-07-01T10:12:31+03:00 Jogilė Mačytė valdas.sablinskas@ff.vu.lt Joana Lach valdas.sablinskas@ff.vu.lt Rasa Platakytė valdas.sablinskas@ff.vu.lt Justinas Čeponkus valdas.sablinskas@ff.vu.lt Marim Ali valdas.sablinskas@ff.vu.lt Aleksa Valdemaras valdas.sablinskas@ff.vu.lt Valdas Šablinskas valdas.sablinskas@ff.vu.lt Pawel Rodziewicz valdas.sablinskas@ff.vu.lt Gamil A. Guirgis valdas.sablinskas@ff.vu.lt <p>The structure of the&nbsp;newly synthesised compound, 1-chlorosilacyclopentane (1-ClSiCP), was investigated using vibrational spectroscopy and theoretical calculations. ATR FT-IR and Raman spectroscopy were used to analyse the&nbsp;liquid sample. Matrix isolation FT-IR spectroscopy was used for the&nbsp;analysis of closely located infrared spectral bands of 1-ClSiCP. Spectroscopic data analysis was performed using theoretical methods such as density functional theory (DTF) and ab initio calculations. FT-IR spectra of 1-ClSiCP isolated in Ne and N2 matrices were collected before and after annealing. During the&nbsp;theoretical structural analysis, the&nbsp;envelope (1E) and twisted (2T3) ring shapes, with the&nbsp;chlorine atom in axial and equatorial positions, were investigated utilising the&nbsp;aug-cc-pVTZ basis set included in the&nbsp;MP2 and DFT calculations. Potential energy surface scans were performed to trace the&nbsp;energy changes and the&nbsp;structure of transition states during the&nbsp;ring conversion. Depending on the&nbsp;method applied, the&nbsp;theoretical results indicate the&nbsp;presence of different conformers, including twisted and envelope ring shapes. The&nbsp;experimental results confirm the&nbsp;existence of only one conformer in the&nbsp;twisted ring configuration. Good agreement between the&nbsp;experimental matrix isolation spectra and in the&nbsp;anharmonic approximation calculated IR absorption spectrum of the&nbsp;2T3 conformer is observed. The&nbsp;difference between the&nbsp;calculated and experimental frequencies of the&nbsp;normal modes does not exceed 2%.</p> 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6399 Integrated geochemical assessment of sediments from Plungė Municipal sewage outfall and sediments from Mažoji Sruoja Stream, Lithuania 2025-07-02T08:14:40+03:00 Donatas Kaminskas donatas.kaminskas@gf.vu.lt Stasys Tautkus donatas.kaminskas@gf.vu.lt Matas Vaitkus donatas.kaminskas@gf.vu.lt <p>Modern river sediments are complex systems of mechanical, mineral and chemical composition that are sensitive to changes in the&nbsp;physical and chemical conditions of the&nbsp;surrounding environment. Thus, more complex studies on the&nbsp;organic matter, grain-size fractions, chemical and mineralogical composition of the&nbsp;surrounding soil and sediments are necessary for the&nbsp;reliable interpretation of results. The&nbsp;composite samples from the&nbsp;Plungė town sewage outlet and the&nbsp;Mažoji Sruoja River of topsoil and stream sediments were studied. The&nbsp;major goal of the&nbsp;study was to evaluate the&nbsp;contamination of topsoil and stream sediments. The&nbsp;mineralogical, grain-size fraction, organic matter and chemical composition of topsoil and stream sediments were determined. The&nbsp;results obtained have revealed that none of the&nbsp;topsoil samples were contaminated. Some of the&nbsp;elements like Cu, Pb, Zn, Cr, As and Mo in stream sediments have values of the&nbsp;coefficient of concentration exceeding 1 and could be considered as potential contaminants. However, there was no any strong relationship between organic matter, clay, silt particles and chemical composition.</p> 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6400 Composition of some macro and micro elements, polyphenol content, antimicrobial and antioxidant activity of Achillea millefolium (L.) grown in Kosovo 2025-07-01T10:12:06+03:00 Fatmir Faiku bleronfaiku@outlook.com Arben Haziri bleronfaiku@outlook.com Fjollë Faiku bleronfaiku@outlook.com Bleron Faiku bleronfaiku@outlook.com <p>This study aimed to determine the&nbsp;composition of several macro and micronutrients (N, P, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Ni, Cr, Cd and Pb), the&nbsp;composition of polyphenols (total polyphenols, total flavonoids and total phenolic acids), antimicrobial activity and antioxidant activity of the&nbsp;plant Achillea millefolium (L.) grown in Kosovo (the eastern part of Kosovo). The&nbsp;concentrations of the&nbsp;analysed macro and micronutrients are as follows: N&nbsp;9.95&nbsp;g/kg, P&nbsp;6.15&nbsp;g/kg, K&nbsp;23.85&nbsp;g/kg, Ca&nbsp;21.98&nbsp;g/kg,<br>Mg&nbsp;6.95&nbsp;g/kg, Fe&nbsp;59.85&nbsp;mg/kg, Zn&nbsp;35.42&nbsp;mg/kg, Cu&nbsp;10.75&nbsp;mg/kg, Mn&nbsp;31.87&nbsp;mg/kg, Co&nbsp;1.15&nbsp;mg/kg, Ni&nbsp;3.01&nbsp;mg/kg, Cr&nbsp;0.45&nbsp;mg/kg, Cd&nbsp;0.035&nbsp;mg/kg and Pb&nbsp;0.65&nbsp;mg/kg. Potassium and calcium were the&nbsp;most abundant macroelements, while iron and zinc were the&nbsp;most abundant micronutrients. The&nbsp;antibacterial efficacy of A.&nbsp;millefolium&nbsp;(L.) was examined using methanol, ethyl acetate, diethyl ether, and water extracts and tested against Staphylococcus aureus (ATTC 25923), Listeria monocytogenes (WSLC 1042) and Escherichia coli (ATCC 25922). Antibacterial activity was determined using the&nbsp;agar disk diffusion meth­od. The&nbsp;inhibition zones from the&nbsp;extracts were compared with that of penicillin G as the&nbsp;standard. Ethyl acetate and diethyl ether extracts showed antibacterial activity against S.&nbsp;aureus and L.&nbsp;monocytogenes, while methanol extracts showed antibacterial activity against S.&nbsp;aureus. The&nbsp;total content of polyphenols (determined using the&nbsp;Folin–Ciocâlteu reagent) was 17.5&nbsp;±&nbsp;0.45&nbsp;mg GAE/g (GAE-gallic acid equivalent). The&nbsp;total content of flavonoids (determined using the&nbsp;aluminum chloride method) was 8.45&nbsp;±&nbsp;0.65&nbsp;mg QE/g (QE-quercetin equivalent), and the&nbsp;total phenolic acid content (determined using Arnova reagent) was 13.2&nbsp;±&nbsp;0.17&nbsp;mg CAE/g (CAE-caffeic acid equivalent). The&nbsp;antioxidant activity determined using the&nbsp;2,2-diphenyl-1-picrylhydrazyl (DPPH) and phosphomolybdenum methods had values of 9.85&nbsp;±&nbsp;0.15 and 185.7&nbsp;±&nbsp;1.75&nbsp;mg TE/g, respectively.</p> 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6407 FT-IR and Raman spectroscopy for the study of amber and other fossil resins 2025-07-01T10:13:12+03:00 Gintarė Martinkutė-Baranauskienė gintare.martinkute@chgf.stud.vu.lt Martynas Talaikis gintare.martinkute@chgf.stud.vu.lt Petras Šinkūnas gintare.martinkute@chgf.stud.vu.lt Jonas Kiuberis gintare.martinkute@chgf.stud.vu.lt <p>This study compares the&nbsp;FT-IR and Raman spectra of amber and other fossil resins from different world regions. The&nbsp;spectra of those resins were analysed based on absorption bands related to the&nbsp;vibrational frequencies of various functional groups present in these compounds. Both spectroscopic methods, FT-IR and Raman, are well-suited for the&nbsp;non-destructive identification of various fossil resins. It was found that FT-IR spectroscopy is particularly suitable for identifying Baltic amber due to its characteristic peak in the&nbsp;1250–1175&nbsp;cm–1 wavelength region. Raman spectroscopy can provide helpful information regarding the&nbsp;degree of maturation of resins. The&nbsp;presence of specific Raman bands, such as 1771–1543 and 1510–1400&nbsp;cm–1, as well as 745 and 696&nbsp;cm–1, can help determine not only the&nbsp;resin’s maturity but also any structural changes that occurred during burial over the&nbsp;geological time of different lengths.</p> 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6402 On the optimisation of the broadband NIR emitter LiScO2:Cr3+ 2025-07-01T10:11:52+03:00 Leoni Frehmeyer timpier@fh-muenster.de Tim Pier timpier@fh-muenster.de Thomas Jüstel timpier@fh-muenster.de <p>Cr3+-activated LiScO2 has emerged as a&nbsp;promising near-infrared (NIR) phosphor with potential applications in medical and optical technologies. In this study, the&nbsp;luminescence properties of LiScO2:Cr3+ were optimised through systematic cation substitutions. The&nbsp;effect of Cr3+-concentration (0.5 to 5&nbsp;mol.%) was investigated, along with substitutions of Sc3+ by Al3+ and Li+ by Na+. The&nbsp;synthesised phosphors were characterised upon using X-ray diffraction (XRD), reflectance spectroscopy, fluorescence spectroscopy, and decay curve analysis. The&nbsp;results demonstrate that optimal Cr3+ doping concentrations enhance NIR emission, whereas excessive doping leads to concentration quenching. Substitutions of Sc3+ with Al3+ and Li+ with Na+ impact crystal field strength and luminescence properties. These findings contribute to the&nbsp;development of efficient broadband NIR phosphors for future applications.</p> 2025-06-27T00:00:00+03:00 Copyright (c) https://lmaleidykla.lt/ojs/index.php/chemija/article/view/6403 Synthesis and antimicrobial screening of heterocycles derived from 3-[(4-benzyloxy)phenyl]-1- (3-chlorophenyl)prop-2-ene-1-one 2025-07-01T10:11:39+03:00 Gheorghe Roman gheorghe.roman@icmpp.ro Mihaela Balan-Porcăraşu gheorghe.roman@icmpp.ro Mihaela Dascălu gheorghe.roman@icmpp.ro Irina Roşca gheorghe.roman@icmpp.ro <p>Starting from the&nbsp;title enone (whose single crystal X-ray structure is being reported herein), a&nbsp;small library of structurally diverse heterocycles has been assembled through ring closure reactions with the&nbsp;view to evaluate their antimicrobial activity. A&nbsp;multi-step sequence comprising the&nbsp;reaction of the&nbsp;mentioned chalcone analogue with hydrazine, the&nbsp;N-acylation of the&nbsp;resulting pyrazoline with bromoacetyl bromide and the&nbsp;replacement of the&nbsp;easily leaving halogen atom in the&nbsp;acylated pyrazoline with a&nbsp;4-methylumbelliferone moiety afforded a&nbsp;pyrazoline–coumarin hybrid. Investigation of the&nbsp;reaction of this chalcone analogue with guanidine allowed the&nbsp;isolation of a&nbsp;2-aminopyrimidine derivative, while an imidazolone was obtained from guanidine and the&nbsp;epoxide of the&nbsp;chalcone analogue. Cyclocondensation of the&nbsp;chalcone analogue with 2-aminobenzenethiol yielded the&nbsp;expected benzothiazepine derivative. Reaction of the&nbsp;chalcone analogue with malononitrile in the&nbsp;presence of sodium methoxide in methanol led to a&nbsp;mixture of two structurally related pyridines. The&nbsp;heterocycles obtained from the&nbsp;title chalcone analogue were devoid of antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans at a&nbsp;concentration of 100&nbsp;mg/mL.</p> 2025-06-27T00:00:00+03:00 Copyright (c)