TY - JOUR AU - Várhelyi, Csaba, ifj. AU - Homonnay, Zoltán AU - Szalay, Roland AU - Pokol, György AU - Szilágyi, Imre Miklós AU - Huszthy, Péter AU - KUBUKI, Shiro AU - GOGA, Firuța AU - Tötös, Róbert AU - Simon-Várhelyi, Melinda AU - Kuzmann, Ernő TI - Mössbauer study of some novel iron-bis-glyoxime and iron-tris-glyoxime complexes JF - HYPERFINE INTERACTIONS J2 - HYPERFINE INTERACT VL - 243 PY - 2022 IS - 1 SN - 0304-3843 DO - 10.1007/s10751-021-01738-2 UR - https://m2.mtmt.hu/api/publication/32561115 ID - 32561115 N1 - Faculty of Chemistry and Chemical Engineering, Babeș-Bolyai University, Cluj, Romania Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary Budapest University of Technology and Economics, Budapest, Hungary Department of Chemistry, Tokyo Metropolitan University, Tokyo, Japan Export Date: 29 April 2022 CODEN: HYIND Correspondence Address: Kuzmann, E.; Institute of Chemistry, Hungary; email: erno.kuzmann@ttk.elte.hu Funding Agency and Grant Number: National Research, Development and Innovation Office - NKFIH/OTKA [K67835, K68135, K115913]; "Domus Hungarica Foundation" of Hungary Funding text: Financial support from the National Research, Development and Innovation Office -NKFIH/OTKA (K67835, K68135, K115913) is gratefully acknowledged. The authors wish to express their thankfulness to the "Domus Hungarica Foundation" of Hungary for the several fellowships provided to Csaba Varhelyi jr. AB - Dioximes as ligands are used as analytical reagents and serve as models for biological systems as well as catalysts in chemical processes. A number of novel mixed complexes of the type [Fe(DioxH)2(amine)2] have been prepared and characterised by FTIR, 57Fe Mössbauer and mass spectroscopy by us. We have found strong Fe–N donor acceptor interactions and iron occurred in low-spin FeII state in all complexes. Later, we have also found that the incorporation of branching alkyl chains (isopropyl) in the complexes alters the Fe–N bond length and results in high-spin iron(II) state [1, 2]. The question arises: can the spin state of iron be manipulated generally by replacing the short alkyl chains with high volume demand ones in Fe-azomethine-amine complexes? To answer the question we have synthetized novel iron-bis-glioxime and iron-tris-gloxime complexes when long chain alkyl or aromatic ligands replaced the short alkyl ones and studied by 57Fe Mössbauer spectroscopy, MS, FTIR, UV-VIS, TG-DTA-DTG and XRD methods. Novel iron-bis-glyoxime and iron-tris-glyoxime type complexes, [Fe(Diethyl-Diox)3(BOH)2], [Fe(Diethyl-Diox)3(BOEt)2] and [Fe(phenyl-Me-Diox)3(BOEt)2], were synthesized similarly as described in [2]. The FTIR, UV-VIS, TG-DTA-DTG and MS measurements indicated that the expected novel complexes could be successfully synthesized. LA - English DB - MTMT ER - TY - BOOK ED - Mizsey, Péter TI - MTA Vegyipari Műveleti és Gépészeti Munkabizottság és MKE Műszaki Kémiai Szakosztály Szakmai Ülés ET - 0 PY - 2018 UR - https://m2.mtmt.hu/api/publication/3358492 ID - 3358492 LA - Hungarian DB - MTMT ER - TY - JOUR AU - Kelemen, Zsolt AU - Hollóczki, Oldamur AU - Oláh, Julianna AU - Nyulászi, László TI - Oxazol-2-ylidenes. A new class of stable carbenes? JF - RSC ADVANCES J2 - RSC ADV VL - 3 PY - 2013 IS - 21 SP - 7970 EP - 7978 PG - 9 SN - 2046-2069 DO - 10.1039/c3ra41177j UR - https://m2.mtmt.hu/api/publication/2693706 ID - 2693706 N1 - Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :18 Export Date: 16 September 2019 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :18 Export Date: 17 September 2019 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Funding Agency and Grant Number: New Szechenyi Plan [TAMOP-4.2.2/B-10/1-2010-0009]; OTKAOrszagos Tudomanyos Kutatasi Alapprogramok (OTKA) [K 170356]; EUEuropean Union (EU); Alexander von Humboldt fellowshipAlexander von Humboldt Foundation; Sumitomo LTD Funding text: Financial support from New Szechenyi Plan TAMOP-4.2.2/B-10/1-2010-0009 and OTKA K 170356 is gratefully acknowledged. J. O. acknowledges receipt of an EU Marie Curie Fellowship (Project "Oestrometab") and O. H. the Alexander von Humboldt fellowship. Support from Sumitomo LTD for Zs. K. is also gratefully acknowledged. Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :20 Export Date: 27 March 2020 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :20 Export Date: 28 March 2020 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :21 Export Date: 11 June 2020 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :22 Export Date: 13 April 2021 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, D-04103 Leipzig, Germany Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, Szt Gellért tér 4, Budapest H-1111, Hungary Cited By :22 Export Date: 15 April 2021 Correspondence Address: Nyulászi, L.; Department of Inorganic and Analytical Chemistry, Szt Gellért tér 4, Budapest H-1111, Hungary; email: nyulaszi@mail.bme.hu Funding Agency and Grant Number: New Szechenyi Plan [TAMOP-4.2.2/B-10/1-2010-0009]; OTKAOrszagos Tudomanyos Kutatasi Alapprogramok (OTKA) [K 170356]; EUEuropean Commission; Alexander von Humboldt fellowshipAlexander von Humboldt Foundation; Sumitomo LTD Funding text: Financial support from New Szechenyi Plan TAMOP-4.2.2/B-10/1-2010-0009 and OTKA K 170356 is gratefully acknowledged. J. O. acknowledges receipt of an EU Marie Curie Fellowship (Project "Oestrometab") and O. H. the Alexander von Humboldt fellowship. Support from Sumitomo LTD for Zs. K. is also gratefully acknowledged. AB - The investigation of the stability of several imidazol-2-ylidene analogue cyclic carbenes by an isodesmic reaction has revealed that the hitherto unknown oxazol-2-ylidene exhibits only slightly smaller stability than imidazol-2-ylidene, outperforming some of the already synthesized carbenes. Selenazol-2-ylidene also shows significant stability. The contribution of aromaticity to the stabilization has been analysed for the different five-membered ring carbenes, and was found to be relatively small for the oxygen containing systems. Investigation of possible reactivity/decomposition pathways reveals that properly substituted oxazol-2-ylidene is stable against dimerization. The thermodynamically feasible cycloreversion reaction yielding isocyanate and acetylene is prevented by a significant barrier, and furthermore with proper substitution (ring annellation) the ring can be stabilized thermodynamically as well. While in the presence of water a hydrolytic ring opening occurs; this reaction can be hindered if the water content of the reaction mixture is reduced to a few equivalents. This hydrolytic behaviour as well as the electrophilicity and nucleophilicity indices of several known nucleophilic carbenes were compared, revealing that oxazol-2-ylidene exhibits a reduced nucleophilicity with respect to imidazol-2-ylidene, while its electrophilicity is only slightly increased. This unique combination might result in unexpected (organo) catalytic activities, further expanding the colourful applications of NHCs. LA - English DB - MTMT ER - TY - JOUR AU - Bakk, I P AU - Deme, I AU - Szieberth, Dénes AU - Nyulászi, László TI - Molecular Level Investigation of the dynamic structure model in molten and solid alkali glasses JF - STRUCTURAL CHEMISTRY J2 - STRUCT CHEM VL - 23 PY - 2012 IS - 6 SP - 1729 EP - 1738 PG - 10 SN - 1040-0400 DO - 10.1007/s11224-012-9969-2 UR - https://m2.mtmt.hu/api/publication/2687926 ID - 2687926 AB - The structure and bonding of alkali glasses has been investigated using a cluster approach and density functional calculations. The clusters used in the study were selected to account for all the important interactions found on small model compounds. Interaction between alkali ions (M+) and the silica host matrix was investigated in terms of complexation energies and bond distances for bridging (O-b) and non-bridging oxygens (O-nb) as well as for systems containing pentacoordinate silicon. The structures with pentacoordinated silicon are only slightly less stable than the structures with O-nb, the relative stability depends on the ionic character of M+, potassium exhibiting the largest propensity for the formation of pentacoordinated structure. The effect of ring size and interaction between geminal oxygens was also considered, to select the suitable clusters. Pentacoordinated silicon structures (in the vicinity of alkali ions) can open up with a low barrier resulting in O-nb-s at different positions, allowing for the migration of the corresponding alkali ions. Differences in the binding energies and bond distances for the different cations can explain their different mobility. The mismatch of preferred sites corresponding to different M+ ions were shown by investigating the spatial distribution of O-b and O-nb of the siloxane network, as well as the energy barriers for diffusion in pore-like structures. LA - English DB - MTMT ER - TY - JOUR AU - Monto, G AU - Hargittai, Magdolna AU - Hargittai, István TI - Professors Hargittai JF - CURRENT SCIENCE J2 - CURR SCI INDIA VL - 102 PY - 2012 IS - 12 SP - 1626 EP - 1628 PG - 3 SN - 0011-3891 UR - https://m2.mtmt.hu/api/publication/2184833 ID - 2184833 LA - English DB - MTMT ER - TY - JOUR AU - Pogany, P AU - Kovács, Attila AU - Varga, Zoltán AU - Bickehaupt, FM AU - Konings, RJM TI - Theoretical Study of the Structure and Bonding in ThC2 and UC2 JF - JOURNAL OF PHYSICAL CHEMISTRY A J2 - J PHYS CHEM A VL - 116 PY - 2012 IS - 1 SP - 747 EP - 755 PG - 9 SN - 1089-5639 DO - 10.1021/jp210190m UR - https://m2.mtmt.hu/api/publication/2061791 ID - 2061791 AB - The electronic structure and various molecular properties of the actinide (An) dicarbides ThC2 and UC2 were investigated by relativistic quantum chemical calculations. We probe five possible geometrical arrangements: two triangular structures,including an acetylide (C-2) moiety, as well as the linear AnCC, CAnC, and bent CAnC geometries. Our calculations at various levels of theory indicate that the triangular species are energetically more favorable, while the latter three arrangements proved to be higher-energy Structures. Our SO-CASPT2 calculations give the ground-state molecular geometry for both ThC2 and UC2 as the symmetric (C-2v) triangular structure. The similar and, also very close in energy, asymmetric (C-s) triangular geometry belongs to a different electronic state. DFT and single-determinant ab initio methods failed to distinguish between these two similar electronic states demonstrating the power of multiconfiguration ab initio methods to deal with such subtle and delicate problems. We report detailed data on the electronic structure and bonding properties-Of the most relevant structures. LA - English DB - MTMT ER - TY - JOUR AU - Varga, Zoltán AU - Kolonits, Mária AU - Hargittai, Magdolna TI - Comprehensive study of the structure of aluminum trihalides from electron diffraction and computation JF - STRUCTURAL CHEMISTRY J2 - STRUCT CHEM VL - 23 PY - 2012 IS - 3 SP - 879 EP - 893 PG - 15 SN - 1040-0400 DO - 10.1007/s11224-011-9943-4 UR - https://m2.mtmt.hu/api/publication/2061790 ID - 2061790 AB - The molecular geometries of the complete series of aluminum trihalides, AlX3 (X = F, Cl, Br, and I), are discussed based on new gas-phase electron diffraction (GED) experiments (AlCl3 and Al2Cl6) and on the reanalysis of our previous GED data (for the rest of the series) with an improved and analogous treatment of the temperature effect on the average bond lengths. This is the first time that all structure analyses are based on GED experiments of homogeneous vapors; either as pure monomers or dimers. The structures of other small oligomers as well as those of the crystals of aluminum trihalides are also discussed. LA - English DB - MTMT ER - TY - JOUR AU - Krámos, Balázs AU - Karancsiné Menyhárd, Dóra AU - Oláh, Julianna TI - Direct Hydride Shift Mechanism and Stereoselectivity of P450nor Confirmed by QM/MM Calculations JF - JOURNAL OF PHYSICAL CHEMISTRY B J2 - J PHYS CHEM B VL - 116 PY - 2012 IS - 2 SP - 872 EP - 885 PG - 14 SN - 1520-6106 DO - 10.1021/jp2080918 UR - https://m2.mtmt.hu/api/publication/1838936 ID - 1838936 N1 - Cited By :19 Export Date: 15 April 2021 CODEN: JPCBF Correspondence Address: Oláh, J.; Materials Structure and Modeling Research Group, Hungarian Academy of Sciences, Budapest University of Technology and Economics, P.O. Box 91, H-1521 Budapest, Hungary; email: olahjulcsi@gmail.com LA - English DB - MTMT ER - TY - JOUR AU - Groen, CP AU - Kovács, Attila AU - Varga, Zoltán AU - Hargittai, Magdolna TI - Molecular Structure and Vibrational Spectra of Mixed MDyX4 (M = Li, Na, K, Rb, Cs; X = F, Cl, Br, I) Vapor Complexes: A Computational and Matrix-Isolation Infrared Spectroscopic Study JF - INORGANIC CHEMISTRY J2 - INORG CHEM VL - 51 PY - 2012 SP - 543 EP - 556 PG - 14 SN - 0020-1669 DO - 10.1021/ic202009v UR - https://m2.mtmt.hu/api/publication/1777903 ID - 1777903 LA - English DB - MTMT ER - TY - JOUR AU - Hargittai, István TI - "Lehetetlen" anyag JF - TERMÉSZET VILÁGA J2 - TERMÉSZET VILÁGA VL - 143 PY - 2012 IS - 2 SP - 50 EP - 54 PG - 5 SN - 0040-3717 UR - https://m2.mtmt.hu/api/publication/1769111 ID - 1769111 LA - Hungarian DB - MTMT ER -