Determination of the Hydration Number of Gadolinium(III) Complexes by High-Field Pulsed 17O ENDOR Spectroscopy (pages 1590–1597)
Arnold M. Raitsimring, Andrei V. Astashkin, Debbie Baute, Daniela Goldfarb, Oleg G. Poluektov, Mark P. Lowe, Stephan G. Zech and Peter Caravan
Article first published online: 30 JUN 2006 | DOI: 10.1002/cphc.200600138
Hydration numbers: High-field pulsed 17O ENDOR is used to determine the number of inner-sphere water molecules for gadolinium-based magnetic resonance imaging contrast agents. The feature at ±0.67 MHz (arrow) is indicative of coordinated water (see picture). Compounds without inner-sphere water (blue trace) do not show this feature, nor exhibit significant ENDOR amplitude at this frequency. The red trace is a novel compound with one coordinated water molecule.