Találati lista | Tudóstér

001-es BibID:	BIBFORM100007
035-os BibID:	(WoS)000739628200001 (Scopus)85123758171
Első szerző:	Pérez-Lourido, Paulo
Cím:	Stable and inert macrocyclic cobalt(II) and nickel(II) complexes with paraCEST response / Paulo Pérez-Lourido, Enikő Madarasi, Fanni Antal, David Esteban-Gómez, Gaoji Wang, Goran Angelovski, Carlos Platas-Iglesias, Gyula Tircsó, Laura Valencia
Dátum:	2022
ISSN:	1477-9226
Megjegyzések:	We report the synthesis of the macrocyclic ligands 3,9 PC2AMH (2,2'-(3,6,9-triaza-1(2,6)-pyridinacyclodecaphane-3,9-diyl)diacetamide) and 3,9-PC2AMtBu (2,2'-(3,6,9-triaza-1(2,6)-pyridinacyclodecaphane-3,9-diyl)bis(N-tert-butyl)acetamide) which contain a pyclen platform functionalized with acetamide or tert-butylacetamide pendant arms at positions 3 and 9 of the macrocyclic unit. The corresponding Co(II) and Ni(II) complexes were prepared, isolated and characterised as potential paramagnetic chemical exchange saturation transfer (paraCEST) agents. The X-ray structures of the Ni(II) complexes reveal six-coordination of the ligands to the metal ion. The Co(II) complex with 3,9-PC2AMtBu shows a similar six-coordinate structure in the solid state, while the Co(II) complex with 3,9 PC2AMH contains a seven-coordinate metal ion, seventh coordination being completed by the presence of an inner-sphere water molecule. The structure of the Co(II) complexes was investigated using 1H NMR spectroscopy and computational methods. The complexes present a seven-coordinate structure in solution, as demonstrated by the analysis of the paramagnetic shifts using density functional theory. Ligand protonation constants and stability constants of the complexes with 3,9 PC2AMH were determined using potentiometric titrations (I=0,15 M NaCl). The Co(II) complex was found to be more stable than the Ni(II) analogue (log KCoL = 14.46(5) and log KNiL = 13.15(3)). However, the Ni(II) and Co(II) complexes display similar rate constants characterizing the proton-assisted dissociation mechanism. The presence of highly shifted 1H NMR signals due to the amide protons in slow exchange with bulk water results in sizeable CEST signals, which are observed at +67 and +15 ppm for the Co(II) complex with 3,9 PC2AMH and +42 and +7 ppm for the Ni(II) analogue at 25 oC .
Tárgyszavak:	Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban folyóiratcikk paraCEST PC2A-bis(amides) stability inertnes, structure
Megjelenés:	Dalton Transactions. - 51 : 4 (2022), p. 1580-1593. -
További szerzők:	Madarasi Enikő Antal Fanni Esteban-Gómez, David Wang, Gaoji Angelovski, Goran Platas-Iglesias, Carlos Tircsó Gyula (1977-) (vegyész, kémia tanár) Valencia, Laura
Pályázati támogatás:	K-120224 OTKA K-134694 OTKA Doctoral School of Chemistry at the University of Debrecen, Debrecen, Hungary Egyéb COST Action CA15209 "European Network on NMR Relaxometry Egyéb Bilateral Hungarian-Spanish Science and Technology Cooperation Program (2019-2.1.11- TET-2019-00084 supported by NKFIH). Egyéb
Internet cím:	Szerző által megadott URL DOI Intézményi repozitóriumban (DEA) tárolt változat
Borító:
Saját polcon: