TY - JOUR AU - Reizer, Edina AU - Tokaji, György Marcell AU - Palusiak, Marcin AU - Viskolcz, Béla AU - Fiser, Béla TI - The first step of polycyclic aromatic hydrocarbon growth – A case study of hydrogen abstractions by •H, •OH, and •CH3 radical JF - COMPUTATIONAL AND THEORETICAL CHEMISTRY J2 - COMPUT THEOR CHEM VL - 1234 PY - 2024 PG - 7 SN - 2210-271X DO - 10.1016/j.comptc.2024.114530 UR - https://m2.mtmt.hu/api/publication/34717280 ID - 34717280 LA - English DB - MTMT ER - TY - JOUR AU - Dobó, Máté AU - Dombi, Gergely AU - Köteles, István AU - Fiser, Béla AU - Kis, Csenge AU - Szabó, Zoltán-István AU - Tóth, Gergő TI - Simultaneous Determination of Enantiomeric Purity and Organic Impurities of Dexketoprofen Using Reversed-Phase Liquid Chromatography—Enhancing Enantioselectivity through Hysteretic Behavior and Temperature-Dependent Enantiomer Elution Order Reversal on Polysaccharide Chiral Stationary Phases JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 25 PY - 2024 IS - 5 PG - 15 SN - 1661-6596 DO - 10.3390/ijms25052697 UR - https://m2.mtmt.hu/api/publication/34688029 ID - 34688029 N1 - Export Date: 12 April 2024 Correspondence Address: Tóth, G.; Department of Pharmaceutical Chemistry, Hogyes 9, Hungary; email: toth.gergo@semmelweis.hu AB - A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the potential impurities of dexketoprofen, including the distomer R-ketoprofen. After screening the separation capability of four polysaccharide columns (Lux Amylose-1, Lux Amylose-2, Lux Cellulose-1 and Lux Cellulose-2) in polar organic and in reversed-phase modes, appropriate enantioseparation was observed only on the Lux Amylose-2 column in an acidified acetonitrile/water mixture. A detailed investigation of the mobile phase composition and temperature for enantio- and chemoselectivity showed many unexpected observations. It was observed that both the resolution and the enantiomer elution order can be fine-tuned by varying the temperature and mobile phase composition. Moreover, hysteresis of the retention times and enantioselectivity was also observed in reversed-phase mode using methanol/water mixtures on amylose-type columns. This could indicate that the three-dimensional structure of the amylose column can change by transitioning from a polar organic to a reversed-phase mode, which affects the enantioseparation process. Temperature-dependent enantiomer elution order and rare enthalpic/entropic controlled enantioseparation in the operative temperature range were also observed in reversed-phase mode. To find the best methodological conditions for the determination of dexketoprofen impurities, a full factorial optimization design was performed. Using the optimized parameters (Lux Amylose-2 column with water/acetonitrile/acetic acid 50/50/0.1 (v/v/v) at a 1 mL/min flow rate at 20 °C), baseline separations were achieved between all compounds within 15 min. Our newly developed HPLC method was validated according to the current guidelines, and its application was tested on commercially available pharmaceutical formulations. According to the authors’ knowledge, this is the first study to report hysteretic behavior on polysaccharide columns in reversed-phase mode. LA - English DB - MTMT ER - TY - JOUR AU - Hatvani-Nagy, Alpár Ferencz AU - Hajdu, Viktória AU - Ilosvai, Mária Ágnes AU - Muránszky, Gábor AU - Sikora, Emőke AU - Kristály, Ferenc AU - Daróczi, Lajos AU - Viskolcz, Béla AU - Fiser, Béla AU - Vanyorek, László TI - Bentonite as eco-friendly natural mineral support for Pd/CoFe2O4 catalyst applied in toluene diamine synthesis JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 14 PY - 2024 IS - 1 PG - 9 SN - 2045-2322 DO - 10.1038/s41598-024-54792-5 UR - https://m2.mtmt.hu/api/publication/34656926 ID - 34656926 AB - Toluene diamine (TDA) is a major raw material in the polyurethane industry and thus, its production is highly important. TDA is obtained through the catalytic hydrogenation of 2,4-dinitrotoluene (2,4-DNT). In this study a special hydrogenation catalyst has been developed by decomposition cobalt ferrite nanoparticles onto a natural clay-oxide nanocomposite (bentonite) surface using a microwave-assisted solvothermal method. The catalyst particles were examined by TEM and X-ray diffraction. The palladium immobilized on the bentonite crystal surface was identified using an XRD and HRTEM device. The obtained catalyst possesses the advantageous property of being easily separable due to its magnetizability on a natural mineral support largely available and obtained through low carbon- and energy footprint methods. The catalyst demonstrated outstanding performance with a 2,4-DNT conversion rate exceeding 99% along with high yields and selectivity towards 2,4-TDA and all of this achieved within a short reaction time. Furthermore, the developed catalyst exhibited excellent stability, attributed to the strong interaction between the catalytically active metal and its support. Even after four cycles of reuse, the catalytic activity remained unaffected and the Pd content of the catalyst did not change, which indicates that the palladium component remained firmly attached to the magnetic support's surface. LA - English DB - MTMT ER - TY - JOUR AU - Molnár, Attila TI - Az invazív gyomok mezőgazdasági szerepe JF - Kárpátalja.ma J2 - Kárpátalja.ma VL - 2024.02.05. PY - 2024 UR - https://m2.mtmt.hu/api/publication/34649448 ID - 34649448 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Qasim, Hadeer Waleed AU - Hadjadj, Rachid AU - Viskolcz, Béla AU - Fiser, Béla TI - Stoichiometric reaction and catalytic effect of 2-dimethylaminoethanol in urethane formation JF - PHYSICAL CHEMISTRY CHEMICAL PHYSICS J2 - PHYS CHEM CHEM PHYS VL - 26 PY - 2024 IS - 8 SP - 7103 EP - 7108 PG - 6 SN - 1463-9076 DO - 10.1039/D3CP05800J UR - https://m2.mtmt.hu/api/publication/34576072 ID - 34576072 AB - A computational study of the stoichiometric reaction and catalytic effect of 2-dimethylaminoethanol (DMEA) in urethane formation was performed. LA - English DB - MTMT ER - TY - BOOK AU - Kolozsvári, István AU - Andrik, Éva AU - Hadnagy, István AU - Ljubka, Tibor AU - Csoma, Zoltán AU - Kohut, Erzsébet TI - A Beregdédai Tóvár Ornitológiai Rezervátum élővilága és élőhelyi viszonyai PB - II. Rákóczi Ferenc Kárpátaljai Magyar Főiskola CY - Beregszász PY - 2023 SN - 9786178276157 UR - https://m2.mtmt.hu/api/publication/34735134 ID - 34735134 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Qasim, Hadeer Waleed AU - Hadjadj, Rachid AU - Viskolcz, Béla AU - Fiser, Béla TI - Effect of morpholine, and 4-methylmorpholine on urethane formation: a computational study JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 13 PY - 2023 IS - 1 PG - 8 SN - 2045-2322 DO - 10.1038/s41598-023-44492-x UR - https://m2.mtmt.hu/api/publication/34231313 ID - 34231313 AB - A theoretical study of urethane formation through the reaction of phenyl isocyanate and butan-1-ol was carried out, without and in the presence of morpholine, and 4-methylmorpholine catalysts. The reaction with and without catalysts was studied at BHandHLYP/6-31G(d) and G3MP2BHandHLYP levels of theories. The reaction mechanism in the presence of catalysts differs significantly from the catalyst-free case and includes seven steps. The catalyst-free system was investigated along with the catalytic process, the geometries were optimized, and the corresponding thermodynamic properties were calculated. Calculated reactant complexes were compared with crystal structures of morpholine, and 4-methylmorpholine complexed with diols found in the literature. The structures were strikingly similar and thus, the validity of the proposed and studied general organocatalytic reaction mechanism was partially verified. Meanwhile, an irregularity in the energy profile occurred due to the zwitterionic nature of an intermediate. To handle the irregularity, a correction was implemented which handles the appearance of a zwitterionic structure and the corresponding energetic properties. The results showed that morpholine is less effective catalyst compared to 4-methylmorpholine, which can be associated with the difference in their PA (1523.95 and 963.07 kJ/mol, respectively). The current results prove the important role of amine catalysts in urethane synthesis which can be applied in polyurethane catalyst design and development. LA - English DB - MTMT ER - TY - JOUR AU - Al-Mandalawi, Mohammed AU - Mousa, Mohanad AU - Viskolcz, Béla AU - Fiser, Béla AU - Vanyorek, László TI - Recent Advances in Flexible Foam Pressure Sensors: Manufacturing, Characterization, and Applications – a Review JF - POLYMER REVIEWS J2 - POLYM REV PY - 2023 PG - 41 SN - 1558-3724 DO - 10.1080/15583724.2023.2262558 UR - https://m2.mtmt.hu/api/publication/34196193 ID - 34196193 LA - English DB - MTMT ER - TY - JOUR AU - Jakab-Nácsa, Alexandra AU - Garami, Attila AU - Fiser, Béla AU - Farkas, László AU - Viskolcz, Béla TI - Towards Machine Learning in Heterogeneous Catalysis—A Case Study of 2,4-Dinitrotoluene Hydrogenation JF - INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES J2 - INT J MOL SCI VL - 24 PY - 2023 IS - 14 PG - 13 SN - 1661-6596 DO - 10.3390/ijms241411461 UR - https://m2.mtmt.hu/api/publication/34123360 ID - 34123360 N1 - BorsodChem Ltd, Bolyai tér 1, Kazincbarcika, H-3700, Hungary Institute of Chemistry, Faculty of Materials Science and Engineering, University of Miskolc, Egyetemváros, Miskolc, H-3515, Hungary Institute of Energy, Ceramics and Polymer Technology, University of Miskolc, Miskolc, H-3515, Hungary Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc, H-3515, Hungary Ferenc Rakoczi II Transcarpathian Hungarian College of Higher Education, Transcarpathia, Beregszász, 90200, Ukraine Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Lodz, 90-236, Poland Export Date: 31 January 2024 Correspondence Address: Viskolcz, B.; Institute of Chemistry, Egyetemváros, Hungary; email: bela.viskolcz@uni-miskolc.hu AB - Utilization of multivariate data analysis in catalysis research has extraordinary importance. The aim of the MIRA21 (MIskolc RAnking 21) model is to characterize heterogeneous catalysts with bias-free quantifiable data from 15 different variables to standardize catalyst characterization and provide an easy tool to compare, rank, and classify catalysts. The present work introduces and mathematically validates the MIRA21 model by identifying fundamentals affecting catalyst comparison and provides support for catalyst design. Literature data of 2,4-dinitrotoluene hydrogenation catalysts for toluene diamine synthesis were analyzed by using the descriptor system of MIRA21. In this study, exploratory data analysis (EDA) has been used to understand the relationships between individual variables such as catalyst performance, reaction conditions, catalyst compositions, and sustainable parameters. The results will be applicable in catalyst design, and using machine learning tools will also be possible. LA - English DB - MTMT ER - TY - JOUR AU - Hornyák-Mester, Enikő AU - Mentes, Dóra AU - Farkas, László AU - Hatvani-Nagy, Alpár Ferencz AU - Varga, Miklós AU - Viskolcz, Béla AU - Muránszky, Gábor AU - Fiser, Béla TI - Volatile emissions of flexible polyurethane foams as a function of time JF - POLYMER DEGRADATION AND STABILITY J2 - POLYM DEGRAD STABIL VL - 216 PY - 2023 PG - 9 SN - 0141-3910 DO - 10.1016/j.polymdegradstab.2023.110507 UR - https://m2.mtmt.hu/api/publication/34113601 ID - 34113601 LA - English DB - MTMT ER -