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001-es BibID:	BIBFORM018844
Első szerző:	Aime, Silvio
Cím:	Properties, Solution State Behavior, and Crystal Structures of Chelates of DOTMA / Silvio Aime, Mauro Botta, Zoltán Garda, Benjamin E. Kucera, Gyula Tircso, Victor G. Young, Mark Woods
Dátum:	2011
ISSN:	0020-1669
Megjegyzések:	The chemistry of polyamino carboxylates and their use as ligands for Ln3+ ions is of considerable interest from the point of view of the development of new imaging agents. Of particular interest is the chemistry of the macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and its derivatives. Herein we report that the tetramethylated DOTA derivative, DOTMA, possess several properties that, from an imaging agent development point of view, are more advantageous than those of the parent DOTA. In particular, the Ln3+ chelates of DOTMA exhibit a marked preference for the monocapped twisted square antiprismatic coordination isomer which imparts more rapid water exchange kinetics on the chelates; ?M298 was determined to be 85 ns for GdDOTMA. Differential analysis of the 17O R2? temperature profiles of both GdDOTA and GdDOTMA afforded the ?M298 values for the square (SAP) and twisted square antiprismatic (TSAP) isomers of each chelate that were almost identical: 365 ns (SAP) and 52 ns (TSAP). The origin of this accelerated water exchange in the TSAP isomer appears to be the slightly longer Gd?OH2 bond distance (2.50 Å) that is observed in the crystal structure of GdDOTMA which crystallizes in the P2 space group as a TSAP isomer. The Ln3+ chelates of DOTMA also exhibit high thermodynamic stabilities ranging from log KML = 20.5 for CeDOTMA, 23.5 for EuDOTMA and YbDOTMA comparable to, but a shade lower than, those of DOTA.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:	Inorganic Chemistry. - 50 : 17 (2011), p. 7955-7965. -
További szerzők:	Botta, Mauro Garda Zoltán (1989-) (vegyész) Kucera, Benjamin E. Tircsó Gyula (1977-) (vegyész, kémia tanár) Young, Victor G. Woods, Mark
Internet cím:	DOI Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM057618
Első szerző:	Molnár Enikő (vegyész)
Cím:	Picolinate-Containing Macrocyclic Mn(II) Complexes as Potential MRI Contrast Agents / Enikő Molnar, Nathalie Camus, Veronique Patinec, Gabriele A. Rolla, Mauro Botta, Gyula Tircso, Ferenc K. Kalmán, Tamas Fodor, Raphael Tripier, Carlos Platas-Iglesias
Dátum:	2014
ISSN:	0020-1669
Megjegyzések:	We report the synthesis of the ligand Hnompa (6-((1,4,7-triazacyclononan- 1-yl)methyl)picolinic acid) and a detailed characterization of the Mn2+ complexes formed by this ligand and the related ligands Hdompa (6-((1,4,7,10-tetraazacyclododecan-1- yl)methyl)picolinic acid) and Htempa (6-((1,4,8,11-tetraazacyclotetradecan-1-yl)methyl)- picolinic acid). These ligands form thermodynamically stable complexes in aqueous solution with stability constants of logKMnL = 10.28(1) (nompa), 14.48(1) (dompa), and 12.53(1) (tempa). A detailed study of the dissociation kinetics of these Mn2+ complexes indicates that the decomplexation reaction at about neutral pH occurs mainly following a spontaneous dissociation mechanism. The X-ray structure of [Mn2(nompa)2(H2O)2]- (ClO4)2 shows that the Mn2+ ion is seven-coordinate in the solid state, being directly bound to five donor atoms of the ligand, the oxygen atom of a coordinated water molecule and an oxygen atom of a neighboring nompa- ligand acting as a bridging bidentate carboxylate group (1 -carboxylate). Nuclear magnetic relaxation dispersion (1 H NMRD) profiles and 17O NMR chemical shifts and transverse relaxation rates of aqueous solutions of [Mn(nompa)]+ indicate that the Mn2+ ion is six-coordinate in solution by the pentadentate ligand and one innersphere water molecule. The analysis of the 1 H NMRD and 17O NMR data provides a very high water exchange rate of the innersphere water molecule (kex 298 = 2.8 x 109 s -1 ) and an unusually high value of the 17O hyperfine coupling constant of the coordinated water molecule (AO/ = 73.3 ± 0.6 rad s-1 ). DFT calculations performed on the [Mn(nompa)(H2O)]+ ·2H2O system (TPSSh model) provide a AO/ value in excellent agreement with the one obtained experimentally
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban MRI contrast agents Mn(II) complexes equilibrium Kinetics Structure
Megjelenés:	Inorganic Chemistry. - 53 : 10 (2014), p. 5136-5149. -
További szerzők:	Camus, Nathalie Patinec, Véronique Rolla, Gabriele A. Botta, Mauro Tircsó Gyula (1977-) (vegyész, kémia tanár) Kálmán Ferenc K. (1978-) (vegyész) Fodor Tamás (1987-) (vegyész) Tripier, Raphaël Platas-Iglesias, Carlos
Pályázati támogatás:	Centro de Supercomputacion de Galicia (CESGA) Egyéb K-84291 OTKA K-109029 OTKA TÁMOP-4.2.2.A-11/ 1/KONV-2012-0043 TÁMOP János Bolyai Research Scholarship of the Hungarian Academy of Sciences. Egyéb COST TD1004 "Theragnostics Imaging and Therapy: An Action to Develop Novel Nanosized Systems for Imaging-Guided Drug Delivery" Action. Egyéb
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001-es BibID:	BIBFORM067424
035-os BibID:	(WoS)000395753000022 (Scopus)85006969224
Első szerző:	Rodríguez-Rodríguez, Aurora
Cím:	Definition of the labile capping bond effect in lanthanide complexes / Aurora Rodríguez-Rodríguez, Martín Regueiro-Figueroa, David Esteban-Gómez, Teresa Rodríguez-Blas, Véronique Patinec, Raphaël Tripier, Gyula Tircsó, Fabio Carniato, Mauro Botta and Carlos Platas-Iglesias
Dátum:	2017
ISSN:	0947-6539
Megjegyzések:	Two macrocyclic ligands containing a cyclen unit, a methyl group, a picolinate arm, and two acetate pendant arms attached to two nitrogen atoms of the macrocycle either in trans (1,7-H3Medo2?ampa = 2,2·-(7-((6-carboxypyridin-2-yl)methyl)-10-methyl-1,4,7,10-tetraazacyclododecane-1,4-diyl)diacetic acid) or in cis (1,4-H3Medo2?ampa) positions are reported. These ligands provide eight-coordination to the Ln3+ ions, leaving a coordination position available for a water molecule that occupies a capping position in the twisted square antiprismatic polyhedron (1,4-H3Medo2?ampa) or one of the positions of the square antiprism (1,7-H3Medo2?ampa). The charge neutral [Gd(1,7-Medo2?ampa)] complex presents an unprecedentedly low water-exchange rate (kex298=8.8?103?s?1), whereas water exchange in [Gd(1,4-Medo2?ampa)] is three orders of magnitude faster (kex298=6.6?106?s?1). These results showcase the labile capping bond phenomenon: A ligand occupying a capping position is hindered by the environment and thus is intrinsically labile.
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk density functional calculations gadolinium magnetic resonance imaging NMR spectroscopy water exchange
Megjelenés:	Chemistry - a European Journal. - 23 : 5 (2017), p. 1110-1117. -
További szerzők:	Regueiro-Figueroa, Martín Esteban-Gómez, David Rodríguez-Blas, Teresa Patinec, Véronique Tripier, Raphaël Tircsó Gyula (1977-) (vegyész, kémia tanár) Carniato, Fabio Botta, Mauro Platas-Iglesias, Carlos
Pályázati támogatás:	GINOP-2.3.2-15-2016-00008 GINOP OTKA-109029 OTKA OTKA-120224 OTKA János Bolyai Research Scholarship MTA
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