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001-es BibID:	BIBFORM106987
035-os BibID:	(Wos)000645403400001 (Scopus)85103919865 (cikkazonosító)1524
Első szerző:	Kálmán Ferenc K. (vegyész)
Cím:	Expanding the Ligand Classes Used for Mn(II) Complexation: Oxa-aza Macrocycles Make the Difference / Ferenc K. Kálmán, Viktória Nagy, Rocío Uzal-Varela, Paulo Pérez-Lourido, David Esteban-Gómez,Zoltán Garda, Kristof Pota, Roland Mezei, Agnès Pallier, Éva Tóth, Carlos Platas-Iglesias, Gyula Tircsó
Dátum:	2021
ISSN:	1420-3049
Megjegyzések:	We report two macrocyclic ligands based on a 1,7-diaza-12-crown-4 platform functionalizedwith acetate (tO2DO2A2?) or piperidineacetamide (tO2DO2AMPip) pendant arms and a detailed char-acterization of the corresponding Mn(II) complexes. The X?ray structure of [Mn(tO2DO2A)(H2O)]·2H2Oshows that the metal ion is coordinated by six donor atoms of the macrocyclic ligand and one watermolecule, to result in seven-coordination. The Cu(II) analogue presents a distorted octahedral coor-dination environment. The protonation constants of the ligands and the stability constants of thecomplexes formed with Mn(II) and other biologically relevant metal ions (Mg(II), Ca(II), Cu(II) andZn(II)) were determined using potentiometric titrations (I= 0.15 M NaCl, T = 25?C). The conditionalstabilities of Mn(II) complexes at pH 7.4 are comparable to those reported for the cyclen-basedtDO2A2?ligand. The dissociation of the Mn(II) chelates were investigated by evaluating the rateconstants of metal exchange reactions with Cu(II) under acidic conditions (I= 0.15 M NaCl, T = 25?C).Dissociation of the [Mn(tO2DO2A)(H2O)] complex occurs through both proton?and metal?assistedpathways, while the [Mn(tO2DO2AMPip)(H2O)] analogue dissociates through spontaneous andproton-assisted mechanisms. The Mn(II) complex oftO2DO2A2 is remarkably inert with respectto its dissociation, while the amide analogue is significantly more labile. The presence of a watermolecule coordinated to Mn(II) imparts relatively high relaxivities to the complexes. The parametersdetermining this key property were investigated using17O NMR (Nuclear Magnetic Resonance)transverse relaxation rates and1H nuclear magnetic relaxation dispersion (NMRD) profiles.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk manganese magnetic resonance imaging stability dissociation kinetics water exchange contrast agents macrocycles
Megjelenés:	Molecules. - 26 : 6 (2021), p. 1-20. -
További szerzők:	Nagy Viktória Uzal-Varela, Rocío Pérez-Lourido, Paulo Esteban-Gómez, David Garda Zoltán (1989-) (vegyész) Póta Kristóf Mezei Roland Pallier, Agnès Tóth Éva Platas-Iglesias, Carlos Tircsó Gyula (1977-) (vegyész, kémia tanár)
Pályázati támogatás:	K-120224 OTKA K-134694 OTKA
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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