Prehliadanie podľa Autor "Filo, Juraj"

Teraz sa zobrazuje 1 - 3 z 3
  • Obrázok miniatúry
    Položka
    Mechanochemical sequential deoxygenative cross-coupling reactions of phenols under ruthenium-nickel catalysis
    (Multidisciplinary Digital Publishing Institute : Basel, 2025) Mkrtchyan, Satenik; Purohit, Vishal; Jakubczyk, Michał; Prajapati, Vaibhav D.; Prajapati, Ronak V.; Garcia, Michael G.; Karpun, Yevhen; Yepishev, Vitaliy; Saini, Manoj K.; Sarfaraz, Sehrish; Ayub, Khurshid; Addová, Gabriela; Filo, Juraj; Iaroshenko, Viktor O.
    One of the key modeling procedures is model verification, which ensures its reliability and confidence. In many respects, the length of the crown is an interesting biophysical property. Precise determination of crown length can be one of the components used in estimating the mass of needles or leaf area index (LAI), and consequently the amount of transpiration or the amount of carbon dioxide bound, which is crucial in the context of climate change. The objective of this study was to calculate the length of the crown Pinus sylvestris using an allometric model and to compare these results with the actual ones to establish the degree of discrepancy. The model that was tested was based on three predictor variables, i.e., diameter at breast height, tree height, and stand density index. The verification was carried out using empirical data collected for 300 sample trees on 20 experimental plots located in south-western Poland. All the stands were pine monocultures located in the habitats of fresh or mixed fresh forest aged from 28 to 40 years. The studied stands differed in terms of diameter at breast height, height, and density (0.68–1.81). The comparison between empirical (𝐶𝐿𝑒𝑚𝑝 ) and calculated (𝐶𝐿𝑐𝑎𝑙 ) mean crown lengths in the stand using the model was expressed by the correlation coefficient’, which was R = 0.955, with a divergence (±) of 4.57%. The tested model is dedicated to calculating the length of tree crowns at the population level. The model uses a density index, which is a constant value for all trees within the area. Further work is needed to improve the model and allow for precise calculation of the crown length of a single tree, taking into account the space it has at its disposal.
  • Obrázok miniatúry
    Položka
    Mechanochemical trifluoromethoxylation of aryltrimethylammonium triflates, aryldiazonium tetrafluoroborates, and aryl pinacolboranes
    (Cell Press : Cambridge, 2024) Mkrtchyan, Satenik; Purohit, Vishal; Zapletal, Jiří; Shalimov, Oleksandr O.; Nociarová, Jela; Addová, Gabriela; Filo, Juraj; Garcia, Michael G.; Kupcová, Elena; Benická, Barbora; Iaroshenko, Viktor O.
    Aryl trifluoromethyl ethers (ArOCF3) are important structural motifs in pharmaceuticals, agrochemicals, and functional materials. However, the methods reported for the efficient synthesis of these scaffolds are extremely underdeveloped and limited. Here, we report a highly efficient mechanochemical approach for the selective transformation of aryltrimethylammonium triflates, aryldiazonium tetrafluoroborates, and aryl pinacolboranes to aryl trifluoromethyl ethers via in situ-generated OCF3 source using triphosgene and Co(II) fluoride (CoF2). The proposed synthetic protocol also shows potential for the selective transformation of other groups such as arylsulfonium and diaryliodonium functionalities. The present trifluoromethoxylation strategy exhibited a broad functional group tolerance and found to be superior over other existing protocols in terms of substrate scope, yields, operational simplicity, and reaction times.
  • Obrázok miniatúry
    Položka
    Thermodynamics and kinetics of early stages of carbon dot formation: a case of citric acid and ethylenediamine reaction
    (The Royal Society of Chemistry : Cambridge, 2025) Pykal, Martin; Nociarová, Jela; Řeha, David; Filo, Juraj; Šebela, Marek; Zajíček, Petr; Paloncýová, Markéta; Olla, Chiara; Mocci, Francesca; Cappai, Antonio; Carbonaro, Carlo Maria; Baďura, Zdeněk; Zdražil, Lukáš; Zbořil, Radek; Rogach, Andrey L.; Medveď, Miroslav; Otyepka, Michal
    Owing to their extraordinary photophysical properties, carbon dots (CDs) have found applications across various fields, including bioimaging, sensing, and environmental research. Despite huge application potential, the fabrication of CDs still lacks the desired control at the molecular level, and precise structural regulation towards property-tailored CDs remains elusive. The mechanistic details of nucleation, growth, and carbonization processes leading to CDs are still unknown, with key thermodynamic and kinetic parameters yet to be revealed. Herein, we performed quantum chemical calculations of explicitly micro-hydrated reaction systems to thoroughly explore the mechanism of a prototypical reaction of citric acid and ethylenediamine. The theoretical results showed activation barriers and thermodynamics along the reaction pathway, thus helping identify key heterocyclic intermediates and cyclization products. The cyclization and condensation reactions were further simulated via a reactive molecular dynamics protocol, suggesting potential growth scenarios and generating plausible structures for further exploration of the polymerization and carbonization processes. The theoretical calculations were cross-validated with NMR and MALDI-TOF measurements. The data obtained provide a comprehensive deterministic insight into the initial stages of CD formation, revealing new reaction intermediates and pathways, and rationally predicting the formation of specific structural arrangements of premature CDs. The presented deterministic approach represents an important step towards rational bottom-up design of these unique fluorescence systems.