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001-es BibID:	BIBFORM120539
035-os BibID:	(WoS)000362460800037 (Scopus)84942934285
Első szerző:	Forgács Attila (vegyész)
Cím:	Mono-, Bi-, and TrinUclear Bis-Hydrated Mn2+ Complexes as Potential MRI Contrast Agents / Attila Forgacs, Martín Regueiro-Figueroa, JoséLuis Barriada, David Esteban-Gomez, Andres de Blas, Teresa Rodríguez-Blas, Mauro Botta, Carlos Platas-Iglesias
Dátum:	2015
ISSN:	0020-1669 1520-510X
Megjegyzések:	We report a series of ligands containing pentadentate 6,6'-((methylazanediyObis(methylene))dipicolinic acid binding units that form mono- (H(2)dpama), di- (mX(H(2)dpama)(2)), and trinudear (mX(H(2)dpama)(3)) complexes with Mn2+ containing two coordinated water molecules per metal ion, which results in pentagonal bipyramidal coordination around the metal ions. In contrast, the hexadentate ligand 6,6'-((ethane-1,2-diylbis(azanediyl))bis(methylene))dipicolinic acid (H2bcpe) forms a complex with distorted octahedral coordination around Mn2+ that lacks coordinated water molecules. The protonation constants of the ligands and the stability constants of the Mn2+, Cu2+, and Zn2+ complexes were determined using potentiometric and spectrophotometric titrations in 0.15 M NaCl. The "pentadentate dpama(2-) ligand and the di- and trinudeating mX(dpama)(2)(4-) and mX(dpama)(3)(6-) ligands provide metal complexes with stabilities that are very similar to that of the complex with the hexadentate ligand bcpe2-, with log beta(101) values in the range 10.1-11.6. Cyclic voltammetry experiments on aqueous solutions of the [Mn(bcpe)] complex reveal a quasireversible system with a half-wave potential of +595 mV versus Ag/AgCl. However, [Mn(dpama)] did not suffer oxidation in the range 0.0-1.0 V, revealing a higher resistance toward oxidation. A detailed H-1 NMRD and O-17 NMR study provided insight into the parameters that govern the relaxivity for these systems. The exchange rate of the coordinated water molecules in [Mn(dpama)] is relatively fast, k(ex)(298) = (3.06 +/- 0.16) X 10(8) s(-1). The trinudear [mX(Mn(dpama)(H2O)(2))(3)] complex was found to bind human serum albumin with an association constant of 1286 +/- 55 M-1 and a relaxivity of the adduct of 45.2 +/- 0.6 mM(-1) at 310 K and 20 MHz.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk
Megjelenés:	Inorganic Chemistry. - 54 : 19 (2015), p. 9576-9587. -
További szerzők:	Regueiro-Figueroa, Martín Barriada, José Luis Esteban-Gómez, David de Blas, Andrés Rodríguez-Blas, Teresa Botta, Mauro Platas-Iglesias, Carlos
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM120536
035-os BibID:	(WoS)000395442700024 (Scopus)85011024075
Első szerző:	Forgács Attila (vegyész)
Cím:	Developing the family of picolinate ligands for Mn2+ complexation / Attila Forgács, Rosa Pujales-Paradela, Martín Regueiro-Figueroa, Laura Valencia, David Esteban-Gómez, Mauro Botta, Carlos Platas-Iglesias
Dátum:	2017
ISSN:	1477-9226
Megjegyzések:	We have reported here a series of ligands containing pentadentate 6,6'-(azanediylbis(methylene)) dipicolinic acid units that differ in the substituent present at the amine nitrogen atom (acetate: H(3)DPAAA; phenyl: H(2)DPAPhA; dodecyl: H(2)DPAC12A; 4-hexylphenyl: H(2)DPAC6PhA). The protonation constants of the hexadentate DPAAA(3-) and pentadentate DPAPhA(2-) ligands and the stability constants of their Mn2+ complexes were determined using pH-potentiometry (25 degrees C, 0.15 M NaCl). The mono-hydrated [Mn(DPAAA)](-) complex (log K-MnL = 13.19(5)) was found to be considerably more stable than the bis-hydrated [Mn(DPAPhA)] analogue (log K-MnL = 9.55(1)). A detailed H-1 and O-17 NMR relaxometric study was carried out to determine the parameters that govern the proton relaxivities of these complexes. The [Mn(DPAC12A)] complex, which contains a dodecyl lipophilic chain, forms micelles in solution characterized by a critical micellar concentration (cmc) of 96(9) mu M. The lipophilic [Mn(DPAC6PhA)] and [Mn(DPAC12A)] derivatives form rather strong adducts with Human Serum Albumin (HSA) with association constants of 7.1 +/- 0.1 x 10(3) and 1.3 +/- 0.4 x 10(5) M (1), respectively. The X-ray structure of the complex {K(H2O)(4)}{[Mn(DPAAA)(H2O)]}(2) shows that the Mn2+ ion in [Mn(DPAAA)](-) is coordinated to the six donor atoms of the ligand, a coordinated water molecule completing the pentagonal bipyramidal coordination environment.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk magnetic resonance imaging manganese complexes picolinate ligands relaxivity DFTcalculations
Megjelenés:	Dalton Transactions. - 46 : 5 (2017), p. 1546-1558. -
További szerzők:	Pujales-Paradela, Rosa Regueiro-Figueroa, Martín Valencia, Laura Esteban-Gómez, David Botta, Mauro Platas-Iglesias, Carlos
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: