Strategies to enhance signal intensity with paramagnetic fluorine-labelled lanthanide complexes as probes for 19F magnetic resonance

摘要

The synthesis and 19F NMR spectroscopic properties are reported for three series of CF3-labelled lanthanide(iii) complexes, based on mono- and diamide cyclen ligands. Analyses of variable temperature, pH and field 19F, 17O and 1H NMR spectroscopic experiments are reported and the merits of a triphosphinate mono-amide complex defined by virtue of its favourable isomer distribution and attractive relaxation properties. These lead to an enhanced sensitivity of detection in 19F magnetic resonance experiments versus a diamagnetic Y(iii) analogue, paving the way for future shift and imaging studies.