Találati lista | Tudóstér

001-es BibID:	BIBFORM103200
035-os BibID:	(Wos)000496535000022 (Scopus)85074872889
Első szerző:	Fehér Péter Pál (vegyész)
Cím:	The mechanism of monochloramine disproportionation under acidic conditions / Fehér Péter Pál, Purgel Mihály, Lengyel Adrienn, Stirling András, Fábián István
Dátum:	2019
ISSN:	1477-9226
Megjegyzések:	Monochloramine is a widely employed agent in water treatment technologies. However, its utilization has some drawbacks like the transformation of the active species into the undesired dichloramine. Although it is more pronounced in acidic solutions, the features of this reaction have still remained largely unexplored in the pH < 4 region. In this study the decomposition of monochloramine is examined under such conditions by using kinetic and computational methods. Fast kinetics measurements have convincingly showed that the disproportion into dicloramine is relatively fast and can be studied without any interference from side reactions. By varying the pH, the deprotonation constant of monochloramine has been determined by UV spectroscopy (Ka = 0.023 ? 0.005 M for I = 1.0 M NaClO4, and T = 25.0 ?C). Dichloramine formation via monochloramine disproportion was found to follow second-order kinetics. The computations have provided the reaction mechanism and its free energy profile in accord with the proposed kinetic model. This involves the reaction between the protonated and unprotonated forms of monochloramine, with a rate constant k = 335.3 ? 11.8 M?1 s ?1 , corresponding to an activation free energy barrier of 14.1 kcal mol?1 . The simulations predicted a barrier of 14.9 kcal mol?1 and revealed a key short-lived chlorine-bridged intermediate which yields dichloroamine and ammonium ion through a deprotonation-coupled chlorine shift.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Dalton Transactions. - 48 : 44 (2019), p. 16713-16721. -
További szerzők:	Lengyel Adrienn Stirling András Purgel Mihály (1982-) (vegyész) Fábián István (1956-) (vegyész)
Pályázati támogatás:	(K_17- 124983) Egyéb (NKFIH 116034) Egyéb GINOP-2.3.2-15-2016-00008 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon:

001-es BibID:	BIBFORM075377
035-os BibID:	(WoS)000414686500014 (Scopus)85029546730
Első szerző:	Nagy Miklós (vegyész)
Cím:	Solvatochromic isocyanonaphthalene dyes as ligands for silver(I) complexes, their applicability in silver(I) detection and background reduction in biolabelling / Miklós Nagy, Dávid Rácz, Zsolt László Nagy, Péter Pál Fehér, József Kalmár, István Fábián, Alexandra Kiss, Miklós Zsuga, Sándor Kéki
Dátum:	2018
ISSN:	0925-4005
Megjegyzések:	The complexation behavior of reactive and nonreactive N-substituted 1-amino-5-isocyanonaphthalene (ICAN) derivatives was studied in the presence of Ag(I) ions by UV-vis, steady-state and time resolved fluorescence measurements. The effect of ligand, solvent and counterion is covered. The equilibrium constants were found to be KAgL ? 106 M?1 in dioxane and water. Complex formation results a significant, solvent dependent (30-59 nm) batochromic shift of the emission maximum. This shift is accompanied by a switch-off effect in the case of the unreactive ligands, while in the case of the acrylated derivative (ACAIN) significant intensity enhancement was detected. Based on spectroscopic results only 1:1 AgL complex could be detected in solution at low concentrations cAgL <10?4 M, while at higher concentrations pure 1:2 AgL2 formed which was characterized by ESI-MS, IR and NMR methods The structure and optical behavior of the complexes are discussed based on high-level quantum chemical calculations. It is shown that the complexation of ACAIN can be used for the selective detection and quantification of silver(I) ions from aqueous media. In addition, the fluorescene switch-off in the case of MICAN yields a significant contrast enhancement in biolabeling applications as is shown on fixated HaCat cells.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk Fluorescence Silver(I) Solvatochromic effect Complex Isonitrile
Megjelenés:	Sensors And Actuators B. Chemical. - 255 : 3 (2018), p. 2555-2567. -
További szerzők:	Rácz Dávid (1987-) (vegyész) Nagy Zsolt László (1989-) (gyógyszerész) Fehér Péter Pál (1991-) (vegyész) Kalmár József (1985-) (vegyész) Fábián István (1956-) (vegyész) Kiss Alexandra (1994-) (gyógyszer-biotechnológus) Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:	GINOP-2.3.2-15-2016-00041 GINOP
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: