Tuning the coordination number of hydroxypyridonate-based gadolinium complexes: implications for MRI contrast agents.
Eight-coordinate hydroxypyridinone/terephthalamide GdIII complexes display high relaxivities due to their two inner sphere water molecules. This relaxivity can be further increased by functionalizing the terephthalamide moiety with an amine. A significant hydrogen bonding interaction between the amine and another water molecule close to the GdIII apparently facilitates its coordination on the open site of the metal. The resulting nine-coordinate complex has three inner sphere water molecules, while maintaining high stability and fast ligand exchange rates.
Pierre
Valérie C
VC
Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Botta
Mauro
M
Aime
Silvio
S
Raymond
Kenneth N
KN
D003287:Contrast Media; D005682:Gadolinium / Q000737:chemistry*; D006860:Hydrogen Bonding; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011728:Pyridones / Q000737:chemistry*
D003287:Contrast Media; D011728:Pyridones; D005682:Gadolinium