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001-es BibID:BIBFORM114075
035-os BibID:(cikkazonosító)122233 (WoS)001024543100001 (Scopus)85162926390
Első szerző:Łyczko, Krzysztof
Cím:Striking stability of a mixed-valence thallium(III)-thallium(I) complex in some solvents / Łyczko, Krzysztof; Wiȩckowska, Agnieszka; Bajnoczi, Éva G.; Csupász, Tibor; Purgel, Mihály; Sigfridsson Clauss, Kajsa G. V.; Tóth, Imre; Persson, Ingmar
Dátum:2023
ISSN:0167-7322
Megjegyzések:At the dissolution of solid anhydrous thallium(III) trifluoromethanesulfonate, Tl(CF3SO3)3, or thallium(III) trifluoroacetate, Tl(CF3COO)3, in dimethylsulfoxide (dmso) or N,N,N',N'-tetramethylurea (tmu), intensely red-colored complexes are formed. This red thallium complex is stable for years in dmso, while it is reduced fairly rapidly to thallium(I) in tmu with a half-life time of an hour. At the dissolution of Tl(CF3SO3)3 in N,N-dimethylpropyleneurea (dmpu) an immediate reduction to thallium(I) takes place. A stable colorless aqueous thallium(III) solution is obtained at the dissolution in acidic water. Stable dmso solutions and solid dmso solvates of thallium(III) perchlorate, nitrate and trifluormethanesulfonate can be prepared by adding dmso to concentrated acidic aqueous thallium(III) solutions. These experimental observations conclude that the pure solids Tl(CF3SO3)3 and Tl(CF3COO)3 play an essential role in the formation of the red-colored thallium complexes. 205Tl NMR data show that the red thallium complex contains equal amounts of thallium(III) and thallium(I). The structure of the red thallium complex in dmso, as determined by EXAFS, has Tl?O bond distances of 2.216(3) and 2.80(2) ?A, which are in very close agreement with the bond distances obtained in the pure dmso solvates of the thallium(III) and thallium(I) ions, respectively, and a Tl???Tl distance of 3.49(1) ?A bridged by oxygen atoms. From the EXAFS data it is impossible to distinguish if dmso molecules and/or trifluoromethanesulfonate ions act as bridges. DFT calculations could eliminate some structures due to the irrelevant structural parameters or the energetics of the proposed reactions.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Mixed-valence thallium(III)-thallium(I) complex
Dimethylsulfoxide
Red-colored complex
N, N, N'N'-tetramethyl urea
Structure
Decomposition rate
Megjelenés:Journal Of Molecular Liquids. - 385 (2023), p. 1-9. -
További szerzők:Wiȩckowska, Agnieszka Bajnoczi Éva G. Csupász Tibor (1991-) (vegyész) Purgel Mihály (1982-) (vegyész) Sigfridsson Clauss, Kajsa G. V. Tóth Imre (1950-) (vegyész) Persson, Ingmar
Pályázati támogatás:TAMOP-4.2.2.C-11/1/KONV-2012-0010
TÁMOP
NKFIH K-128201
Egyéb
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2.

001-es BibID:BIBFORM106898
035-os BibID:(Wos)000866261600004 (Scopus)85138457092
Első szerző:Niemöller, Henrik
Cím:How do alternative amino acids behave in water? A comparative ab initio molecular dynamics study of solvated alpha-amino acids and alpha-amino amidines / Henrik Niemöller, Jan Blasius, Oldamur Hollóczki, Barbara Kirchner
Dátum:2022
ISSN:0167-7322
Megjegyzések:Among hypothetical alternative biochemistries, ammonia based life is one of the more promising ideas to investigate, due to the many similarities of water and ammonia as well as the existence of various ammonia based equivalents to prominent biomolecules. In this scenario a-amino amidines form the analogues to the a-amino acids, which can also be classified as the building blocks of life. Comparison of basic solvation behaviour between a-amino amidines and a-amino acids can provide insight into general chemical properties. To better understand the solvation of these compounds, we conducted ab initio molecular dynamics simulations for alanine, leucine, 2-aminopropionamidine and 2-amino-4- methylpentanamidine dissolved in 128 water molecules. We started simulations both from the neutral as well as from the zwitterionic form. For the alpha-amino amidines we observed protonation of the amidine group by water. Amino acids do not change spontaneously between the two states in our simulations. The molecular dipole moment is highly influenced by the state and conformation of the molecule and is a key property to trace in the course of the simulation. Structural analyses demonstrate the interactions of the compound with the surrounding solvent, solvation shells and hydrogen bonding.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Journal of Molecular Liquids. - 367 (2022), p. 120282-. -
További szerzők:Blasius, Jan Hollóczki Oldamur (1983-) (okleveles vegyészmérnök) Kirchner, Barbara
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3.

001-es BibID:BIBFORM113891
035-os BibID:(cikkazonosító)122716 (WoS)001053307800001 (Scopus)85166955717
Első szerző:Papp Vanda (vegyész, biomérnök)
Cím:State and role of water confined in cement and composites modified with metakaolin and additives / Vanda Papp, Róbert Janovics, Tamás Péter Kertész, Zoltán Nemes, Tamás Fodor, István Bányai, Mónika Kéri
Dátum:2023
ISSN:0167-7322
Megjegyzések:Cement as a porous material contains pores and cracks on the whole nanoscale forming an interconnected pore structure. Its interaction with water during the rehydration of cement plays a key role in every application, such as in nuclear waste treatment, where cement binders are commonly used for conditioning liquid radioactive waste. In the prediction of the long-term disposal the knowledge of water mobility and distribution in the formed porous cement matrix is essential. In this study we systematically investigate the effects of metakaolin and several components of the liquid phase (complexing agents, model ions, boric acid, etc.) on the hydrated solid structure by various nuclear magnetic resonance (NMR) methods. The novelty lies in the complex use of such non-conventional techniques that separately provide only partial information of the cement structure; however, the gained results complete each other to offer a new approach in the structural study under several conditions. Water mobility is deduced from NMR T2 relaxation distributions and D2O-H2O exchange diffusion measurements, and the conclusion on structural properties is supported by the macropore structure revealed from NMR cryoporometry and SEM (scanning electron microscopy) images, as well as by following the formation of pores and water domains in the curing process with NMR relaxometry. The results confirm that metakaolin was built into the CSH (calcium silicate hydrate) gel region without altering its mesoporous structure, however, it significantly decreased the capillary pore size and the diffusion coefficient of water. Complexing agent concentration between 2 and 20 g/l and the presence of model ions did not cause significant structural changes, while the rehydration decreased the size of capillary pores due to swelling.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Journal Of Molecular Liquids. - 388 (2023), p. 1-10. -
További szerzők:Janovics Róbert (1984-) (környezetkutató) Kertész Tamás Péter (2001-) (egyetemi hallgató) Nemes Zoltán (1976-) Fodor Tamás (1987-) (vegyész) Bányai István (1953-) (vegyész) Kéri Mónika (1984-) (környezetkutató vegyész)
Pályázati támogatás:OTKA-135169
OTKA
OTKA-131989
OTKA
KDP-2021
Egyéb
GINOP-2.3.4-15-2020-00007
GINOP
2019-2.1.7-ERA-NET-2021-00021
Egyéb
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Intézményi repozitóriumban (DEA) tárolt változat
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4.

001-es BibID:BIBFORM107570
035-os BibID:(WoS)000636833000048 (Scopus)85099212232 (cikkazonosító)115276
Első szerző:Urbán Béla
Cím:Characterization of the ionic liquid obtained by chlorosulfonation of 1-methylimidazole: 1-methyl-3-sulfonic acid imidazolium chloride, 1-methylimidazolium chlorosulfate or a zwitterionic salt? / Béla Urbán, Gábor Szalontai, Máté Papp, Csaba Fehér, Attila C. Bényei, Rita Skoda-Földes
Dátum:2021
ISSN:0167-7322
Megjegyzések:A great number of organic reactions catalyzed by the ionic liquid product of chlorosulfonation of 1-methylimidazole have been reported recently. At the same time controversial assumptions have appeared on the real structure of the catalyst. In the present report the primarily formed chlorosulfonation product is proved to be 1-methylimidazolium chlorosulfate ([HMim](+)[SO3Cl](-)) instead of 1-methyl-3-sulfonic acid imidazolium chloride, reported previously. The former structure is confirmed by X-ray crystallography and NMR spectroscopy, including H-1-, C-13-, O-17- and N-15-(1)HHSQCmeasurements. H-1 and O-17 NMR experiments support fast hydrolysis of [HMim] [SO3Cl] resulting in the formation of [HMim][HSO4] in the presence of traces of water.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Journal Of Molecular Liquids. - 326 (2021), p. 1-9. -
További szerzők:Szalontai Gábor Papp Máté Fehér Csaba Bényei Attila (1962-) (vegyész) Skoda-Földes Rita
Pályázati támogatás:GINOP-2.3.3-15-2016-00004
GINOP
GINOP-2.3.2-15-2016-00008
GINOP
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Intézményi repozitóriumban (DEA) tárolt változat
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