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001-es BibID:BIBFORM106867
035-os BibID:(Wos)000825749700001 (Scopus)85133129093
Első szerző:Dékány-Adamoczky Anita (anyagmérnök)
Cím:Isocyanonaphthol Derivatives: Excited-State Proton Transfer and Solvatochromic Properties / Anita Adamoczky, Tibor Nagy, Péter Pál Fehér, Veronika Pardi-Tóth, Ákos Kuki, Lajos Nagy, Miklos Zsuga, Sándor Kéki
Dátum:2022
ISSN:1422-0067
Megjegyzések:Fluorescent probes that exhibit solvatochromic or excited-state proton-transfer (ESPT) prop- erties are essential tools for the study of complex biological or chemical systems. Herein, the synthesis and characterization of a novel fluorophore that reveals both features, 5-isocyanonaphthalene-1-ol (ICOL), are reported. Various solvatochromic methods, such as Lippert?Mataga and Bilot?Kawski, together with time-dependent density functional theory (TD-DFT) and time-resolved emission spec- troscopy (TRES), were applied to gain insights into its excited-state behavior. To make comparisons, the octyloxy derivative of ICOL, 5-isocyano-1-(octyloxy)naphthalene (ICON), was also prepared. We found that internal charge transfer (ICT) takes place between the isocyano and ?OH groups of ICOL, and we determined the values of the dipole moments for the ground and excited states of both ICOL and ICON. Furthermore, in the emission spectra of ICOL, a second band at higher wavelengths (green emission) in solvents of higher polarities (dual emission), in addition to the band present at lower wavelengths (blue emission), were observed. The extent of this dual emission increases in the order of 2-propanol < methanol < N,N-dimethylformamide (DMF) < dimethyl sulfoxide (DMSO). The presence of the dual fluorescence of ICOL in these solvents can be ascribed to ESPT. For ICOL, we also determined ground- and excited-state pKa values of 8.4 ? 0.3 and 0.9 ? 0.7, respectively, which indicates a considerable increase in acidity upon excitation. The TRES experiments showed that the excited-state lifetimes of the ICOL and ICON spanned from 10.1 ns to 5.0 ns and from 5.7 ns to 3.8 ns, respectively. In addition, we demonstrated that ICOL can be used as an effective indicator of not only the critical micelle concentration (cmc) of ionic (sodium lauryl sulfate (SLS)) and nonionic surfactants (Tween 80), but also other micellar parameters, such as partition coefficients, as well as to map the microenvironments in the cavities of biomacromolecules (e.g., BSA). It is also pointed out that fluorescence quenching by pyridine can effectively be utilized for the determination of the fractions of ICOL molecules that reside at the water?micelle interface and in the interior spaces of micelles.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:International Journal Of Molecular Sciences. - 23 : 13 (2022), p. 7250-7272. -
További szerzők:Nagy Tibor (1988-) (vegyész) Fehér Péter Pál (1991-) (vegyész) Pardi-Tóth Veronika Csilla Kuki Ákos (1966-) (villamosmérnök) Nagy Lajos (1979-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:K-132685
OTKA
K-132236
OTKA
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM089662
035-os BibID:(cikkazonosító)5588 (scopus)85089170694 (wos)000558993700001
Első szerző:Dékány-Adamoczky Anita (anyagmérnök)
Cím:Conversion of Isocyanide to Amine in The Presence of Water and Hg(II) Ions: Kinetics and Mechanism as Detected by Fluorescence Spectroscopy and Mass Spectrometry / Anita Adamoczky, Lajos Nagy, Miklós Nagy, Miklós Zsuga, Sándor Kéki
Dátum:2020
ISSN:1661-6596 1422-0067
Megjegyzések:Aromatic isocyanides including isocyanonaphthalene derivatives have been proven to be very effective fluorescent sensors for the quantification of Hg(II) ions in water. Thus, the reaction of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which is one of the most important members of this family, with water and HgCl2 as the oxidation agents, was studied by fluorescence spectroscopy and mass spectrometry in order to get deeper insight into the kinetics and mechanistic details of this complex reaction. The reactions of 1,5-ICAN with water and HgCl2 were performed in various water/co-solvent mixtures of different compositions. The co-solvents used in this study were both aprotic solvents including tetrahydrofuran, acetonitrile and N,N-dimethylformamide and protic solvents, such as ethanol and 2-propanol. It was found that in aprotic solvents the conversion of the isocyano group to amino moiety takes place, while in protic solvents the corresponding carbamate (urethane) group is formed in addition to the amino moiety. The variation of the resulting fluorescence intensities versus time curves were described using an irreversible, consecutive reaction model, in which the formation of isocyanate and carbamic acid intermediates, as well as diamino and carbamate (in the case of protic solvents) products were assumed. The formation of these intermediates and products was unambiguously confirmed by mass spectrometric measurements. Furthermore, by fitting the model to the experimental fluorescence versus time curves, the corresponding rate coefficients were determined. It was observed that the overall rate of transformation of the isocyano group to amino moiety increased with the water concentration and the polarity of the co-solvent. It was also supported that formation of diamino and carbamate derivatives in protic solvents takes place simultaneously and that the ratio of the amino to the carbamate function increased with the increasing water concentration. In addition, with an extension, the model presented herein proved to be capable of describing the kinetics of the transformation of 1,5-diisocyanonaphthalene (1,5-DIN) into 1,5-diaminonaphthalene (1,5-DAN) in the mixtures of water/aprotic solvents.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
steady-state fluorescence
kinetics
isocyanoaminonaphthalenes
HgCl2
carbamic acid
carbamate
isocyanate
Megjelenés:International Journal of Molecular Sciences. - 21 : 15 (2020), p. 1-14. -
További szerzők:Nagy Lajos (1979-) (vegyész) Nagy Miklós (1976-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:NKFIH K-132685
egyéb
GINOP-2.3.2-15-2016-00041
GINOP
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3.

001-es BibID:BIBFORM100548
035-os BibID:(cikkazonosító)1444 (scopus)85123624843 (wos)000755083500001
Első szerző:Lakatos Csilla (környezetmérnök)
Cím:Synthesis of Sucrose-HDI Cooligomers : new Polyols for Novel Polyurethane Networks / Lakatos Csilla, Kordován Marcell Árpád, Czifrák Katalin, Nagy Lajos, Vadkerti Bence, Daróczi Lajos, Zsuga Miklós, Kéki Sándor
Dátum:2022
ISSN:1661-6596 1422-0067
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
sucrose
1,6-hexamethylene diisocyanate
cooligomer
polyol
Poly (E-caprolactone)
chemical and physical characterization
Megjelenés:International Journal Of Molecular Sciences. - 23 : 3 (2022), p. 1-13. -
További szerzők:Kordován Marcell Árpád (1994-) (okleveles vegyészmérnök) Czifrák Katalin (1978-) (vegyész) Nagy Lajos (1979-) (vegyész) Vadkerti Bence (1994-) (okleveles vegyészmérnök) Daróczi Lajos (1965-) (fizikus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
FK-128783
Egyéb
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Intézményi repozitóriumban (DEA) tárolt változat
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4.

001-es BibID:BIBFORM098751
035-os BibID:(cikkazonosító)4059 (Scopus)85103999565 (Wos)000644301700001
Első szerző:Nagy Lajos (vegyész)
Cím:Kinetically Equivalent Functionality and Reactivity of Commonly Used Biocompatible Polyurethane Crosslinking Agents / Nagy Lajos, Vadkerti Bence, Lakatos Csilla, Fehér Péter Pál, Zsuga Miklós, Kéki Sándor
Dátum:2021
ISSN:1661-6596 1422-0067
Megjegyzések:In this paper, the kinetics of the reaction of phenyl isocyanate with crosslinking agents such as sucrose, sorbitol, and glycerol are reported. Crosslinking agents were used in high molar excess to isocyanate to obtain pseudo-first-order rate dependencies, and the reaction products were separated by high-performance liquid chromatography and detected by UV spectroscopy and mass spectrometry. It was found that the glycerol's primary hydroxyl groups were approximately four times reactive than the secondary ones. However, in the case of sorbitol, the two primary OH groups were found to be the most reactive, and the reactivity of hydroxyl groups decreased in the order of kOH(6)(8.43) > kOH(1)(6.91) > kOH(5)(1.19) > kOH(2)(0.98) > kOH(3)(0.93) > kOH(4)(0.64), where the numbers in the subscript and in the brackets denote the position of OH groups and the pseudo-first-order rate constants, respectively. The Atomic Polar Tenzor (APT) charges of OH groups and dipole moments of monosubstituted sorbitol derivatives calculated by density functional theory (DFT) also confirmed the experimental results. On the other hand, the reactions of phenyl isocyanate with crosslinking agents were also performed using high excess isocyanate in order to determine the number of OH-groups participating effectively in the crosslinking process. However, due to the huge number of derivatives likely formed in these latter reactions, a simplified reaction scheme was introduced to describe the resulting product versus reaction time distributions detected by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Based on the results, the kinetically equivalent functionality (fk) of each crosslinking agent was determined and found to be 2.26, 2.6, and 2.96 for glycerol, sorbitol, and sucrose, respectively.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
glycerol
sorbitol
sucrose
phenyl-isocyanate
reactivity
kinetics
Megjelenés:International Journal Of Molecular Sciences. - 22 : 8 (2021), p. 1-19. -
További szerzők:Vadkerti Bence (1994-) (okleveles vegyészmérnök) Lakatos Csilla (1990-) (környezetmérnök) Fehér Péter Pál (1991-) (vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
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Intézményi repozitóriumban (DEA) tárolt változat
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5.

001-es BibID:BIBFORM083939
035-os BibID:(cikkazonosító)1318 (scopus)85079681968 (wos)000522524400145
Első szerző:Nagy Lajos (vegyész)
Cím:Encoding Information into Polyethylene Glycol Using an Alcohol-Isocyanate "Click" Reaction / Nagy Lajos, Kuki Ákos, Nagy Tibor, Vadkerti Bence, Erdélyi Zoltán, Kárpáti Levente, Zsuga Miklós, Kéki Sándor
Dátum:2020
ISSN:1661-6596 1422-0067
Tárgyszavak:Természettudományok Fizikai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
monomethoxypolyethylene glycol (mpeg)
alipatic isocyanates
encoding and decoding binary information
maldi-tof ms
Megjelenés:International Journal Of Molecular Sciences. - 21 : 4 (2020), p. 1-9. -
További szerzők:Kuki Ákos (1966-) (villamosmérnök) Nagy Tibor (1988-) (vegyész) Vadkerti Bence (1994-) (okleveles vegyészmérnök) Erdélyi Zoltán (1974-) (fizikus) Kárpáti Levente (1968-) (okleveles vegyész) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:GINOP-2.3.3-15-2016-00021
GINOP
NKFIH-1150-6/2019
Egyéb
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